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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. 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 (NASDA)...

  8. 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 (NASDA)...

  9. 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

  10. 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

  11. Current status of the global change observation mission - water SHIZUKU (GCOM-W) and the advanced microwave scanning radiometer 2 (AMSR2) (Conference Presentation)

    Science.gov (United States)

    Maeda, Takashi; Kachi, Misako; Kasahara, Marehito

    2016-10-01

    Japan Aerospace Exploration Agency (JAXA) launched the Global Change Observation Mission - Water (GCOM-W) or "SHIZUKU" in 18 May 2012 (JST) from JAXA's Tanegashima Space Center. The GCOM-W satellite joins to NASA's A-train orbit since June 2012, and its observation is ongoing. The GCOM-W satellite carries the Advanced Microwave Scanning Radiometer 2 (AMSR2). The AMSR2 is a multi-frequency, total-power microwave radiometer system with dual polarization channels for all frequency bands, and successor microwave radiometer to the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) loaded on the NASA's Aqua satellite. The AMSR-E kept observation in the slower rotation speed (2 rotations per minute) for cross-calibration with AMSR2 since December 2012, its operation ended in December 2015. The AMSR2 is designed almost similarly as the AMSR-E. The AMSR2 has a conical scanning system with large-size offset parabolic antenna, a feed horn cluster to realize multi-frequency observation, and an external calibration system with two temperature standards. However, some important improvements are made. For example, the main reflector size of the AMSR2 is expanded to 2.0 m to observe the Earth's surface in higher spatial resolution, and 7.3-GHz channel is newly added to detect radio frequency interferences at 6.9 GHz. In this paper, we present a recent topic for the AMSR2 (i.e., RFI detection performances) and the current operation status of the AMSR2.

  12. Near-field scanning microwave microscopy of microwave devices

    Science.gov (United States)

    Vlahacos, C. P.; Steinhauer, David E.; Dutta, S.; Anlage, S. M.; Wellstood, F. C.; Newman, H.

    1997-03-01

    We have developed a scanning microwave microscope which can presently image features with a spatial resolution of 10-100 μm in the frequency range 5-15 GHz.(C. P. Vlahacos, et al.), Appl. Phys. Lett. 69, 3272 (1996).^,(S. M. Anlage, et al.), IEEE. Trans. Appl. Supercond. (1997). The microscope consists of a resonant section of a coaxial cable which is terminated with a small-diameter open-ended coaxial probe. Images are made by scanning the sample under the probe while recording the induced near-field microwave voltage as a function of sample position. We will present images for several microwave devices, including an X-band microstrip planar ferrite circulator and a high-temperature superconducting microstrip YBa_2Cu_3O_7-δ resonator, and compare them to the calculated field profiles.

  13. 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

  14. A Scanning Microwave Radar and Radiometer

    DEFF Research Database (Denmark)

    Skou, Niels

    1995-01-01

    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...

  15. Advances In Microwave Metamaterials

    Science.gov (United States)

    Wigle, James A.

    2011-12-01

    Metamaterials are a new area of research showing significant promise for an entirely new set of materials, and material properties. Only recently has three-fourths of the entire electromagnetic material space been made available for discoveries, research, and applications. This thesis is a culmination of microwave metamaterial research that has transpired over numerous years at the University of Colorado. New work is presented; some is complete while other work has yet to be finished. Given the significant work efforts, and potential for new and interesting results, I have included some of my partial work to be completed in the future. This thesis begins with background theory to assist readers in fully understanding the mechanisms that drove my research and results obtained. I illustrate the design and manufacture of a metamaterial that can operate within quadrants I and II of the electromagnetic material space (epsilon r > 0 and mur > 0 or epsilonr 0, respectively). Another metamaterial design is presented for operation within quadrant III of the electromagnetic material space (epsilonr thesis also presents two related, but different, novel tests intended to be used to definitively illustrate the negative angle of refraction for indices of refraction less than zero. It will be shown how these tests can be used to determine most bulk electromagnetic material properties of the material under test, for both right handed and left handed materials, such as epsilonr, mur, deltaloss, and n. The work concluding this thesis is an attempt to derive modified Fresnel Coefficients, for which I actually believe to be incorrect. Though, in transposing I have corrected a few mistakes, and now I can no longer find the conundrum. I have included this work to illuminate the need for modified Fresnel coefficients for cases of negative indices of refraction, identifying all disparate cases requiring a new set of equations, as well as to assist others in their efforts through

  16. 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...

  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. Advanced oxidation scanning probe lithography

    Science.gov (United States)

    Ryu, Yu K.; Garcia, Ricardo

    2017-04-01

    Force microscopy enables a variety of approaches to manipulate and/or modify surfaces. Few of those methods have evolved into advanced probe-based lithographies. Oxidation scanning probe lithography (o-SPL) is the only lithography that enables the direct and resist-less nanoscale patterning of a large variety of materials, from metals to semiconductors; from self-assembled monolayers to biomolecules. Oxidation SPL has also been applied to develop sophisticated electronic and nanomechanical devices such as quantum dots, quantum point contacts, nanowire transistors or mechanical resonators. Here, we review the principles, instrumentation aspects and some device applications of o-SPL. Our focus is to provide a balanced view of the method that introduces the key steps in its evolution, provides some detailed explanations on its fundamentals and presents current trends and applications. To illustrate the capabilities and potential of o-SPL as an alternative lithography we have favored the most recent and updated contributions in nanopatterning and device fabrication.

  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...... as sufficient gain in a wide frequency range of operation, which is very difficult to achieve. Most circuits demonstrated are not stable across the frequency band, which makes these amplifiers prone to self-oscillations and therefore limit their applicability. The trade-off between noise figure, gain, linearity...

  2. Microwave Spectroscopy of Superconductors with a Scanning Low Temperature Near-Field Microwave Microscope

    Science.gov (United States)

    Imtiaz, Atif; Anlage, Steven

    2001-03-01

    We have developed a new tool to study the microwave conductivity and other properties of superconductors: The Cryogenic scanning near-field microwave microscope integrated with STM feedback. This instrument allows localized spectroscopic measurements of these materials in a non-destructive way, at both low and high frequencies. We will discuss results that show it high spatial resolution on metal and superconducting films in the frequency range of 7-11 GHz and compare it to simultaneously-acquired topography of the surface using a scanning tunneling microscope. The high spatial resolution allows us to image the grains and grain boundaries in superconductors, while facilitating local spectroscopy. The instrument allows us to study the electronic properties from STM and the microwave spectroscopic properties of the materials from the microwave microscope simultaneously, and independently of each other. We will also discuss a model of the microscope, which gives a quantitative understanding of the frequency shift and Q, demonstrating that this microscope is qualitatively similar to our earlier version.^1 We shall present images of superconducting films in the critical state and discuss the possibility of imaging magnetic vortices at microwave frequencies. Reference: 1 [D.E.Steinhauer, C.P.vlahacos, S.K.Dutta, B.J.Feenstra, F.C.Wellstood, and Steven M.Anlage, "Quantitative Imaging of Sheet Resistance with a Scanning Near-Field Microwave Microscope," Appl. Phys. Lett. 72, 861 (1998)].

  3. 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.

  4. Scanning microwave microscopy technique for nanoscale characterization of magnetic materials

    Science.gov (United States)

    Joseph, C. H.; Sardi, G. M.; Tuca, S. S.; Gramse, G.; Lucibello, A.; Proietti, E.; Kienberger, F.; Marcelli, R.

    2016-12-01

    In this work, microwave characterization of magnetic materials using the scanning microwave microscopy (SMM) technique is presented. The capabilities of the SMM are employed for analyzing and imaging local magnetic properties of the materials under test at the nanoscale. The analyses are performed by acquiring both amplitude and phase of the reflected microwave signal. The changes in the reflection coefficient S11 are related to the local properties of the material under investigation, and the changes in its magnetic properties have been studied as a function of an external DC magnetic bias. Yttrium iron garnet (YIG) films deposited by RF sputtering and grown by liquid phase epitaxial (LPE) on gadolinium gallium garnet (GGG) substrates and permalloy samples have been characterized. An equivalent electromagnetic transmission line model is discussed for the quantitative analysis of the local magnetic properties. We also observed the hysteretic behavior of the reflection coefficient S11 with an external bias field. The imaging and spectroscopy analysis on the experimental results are evidently indicating the possibilities of measuring local changes in the intrinsic magnetic properties on the surface of the material.

  5. 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.

  6. Imaging of Active Microwave Devices at Cryogenic Temperatures using Scanning Near-Field Microwave Microscopy

    Science.gov (United States)

    Thanawalla, Ashfaq S.; Dutta, S. K.; Vlahacos, C. P.; Steinhauer, D. E.; Feenstra, B. J.; Anlage, Steven M.; Wellstood, F. C.

    1998-03-01

    The ability to image electric fields in operating microwave devices is interesting both from the fundamental point of view and for diagnostic purposes. To that end we have constructed a scanning near-field microwave microscope which uses an open-ended coaxial probe and operates at cryogenic temperatures.(For related publications see: C. P. Vlahacos, R. C. Black, S. M. Anlage, A. Amar and F. C. Wellstood, Appl. Phys. Lett. 69), 3274 (1996) and S. M. Anlage, C. P. Vlahacos, Sudeep Dutta and F. C. Wellstood, IEEE Trans. Appl. Supercond. 7, 3686 (1997). Using this system we have imaged electric fields generated by both normal metal and superconducting microstrip resonators at temperatures ranging from 77 K to 300 K. We will present images and discuss our results including observations of clear standing wave patterns at the fundamental resonant frequency and an increased quality factor of the resonators at low temperatures.

  7. An interferometric scanning microwave microscope and calibration method for sub-fF microwave measurements.

    Science.gov (United States)

    Dargent, T; Haddadi, K; Lasri, T; Clément, N; Ducatteau, D; Legrand, B; Tanbakuchi, H; Theron, D

    2013-12-01

    We report on an adjustable interferometric set-up for Scanning Microwave Microscopy. This interferometer is designed in order to combine simplicity, a relatively flexible choice of the frequency of interference used for measurements as well as the choice of impedances range where the interference occurs. A vectorial calibration method based on a modified 1-port error model is also proposed. Calibrated measurements of capacitors have been obtained around the test frequency of 3.5 GHz down to about 0.1 fF. Comparison with standard vector network analyzer measurements is shown to assess the performance of the proposed system.

  8. Application and research advancement on the microwave-assisted extraction

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; ZHENG Xianzhe

    2007-01-01

    This paper summarized application and research advancement of the microwave-assisted extraction in the agriculture,food industry, environmental analytical chemistry, traditional Chinese medicine industry, and so on. The microwave-assisted extraction was manifested to be a simple device, wide area of application, high extraction efficiency, good reproducibility and low consumption of agent and time as well as low environmental pollution. At present, industrialization question of the microwave-assisted extraction technology has been attached importance, which will impel the microwave-assisted extraction technology to more development in the future.

  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. Quantitative Imaging of Microwave Electric Fields through Near-Field Scanning Microwave Microscopy

    Science.gov (United States)

    Dutta, S. K.; Vlahacos, C. P.; Steinhauer, D. E.; Thanawalla, A.; Feenstra, B. J.; Wellstood, F. C.; Anlage, Steven M.; Newman, H. S.

    1998-03-01

    The ability to non-destructively image electric field patterns generated by operating microwave devices (e.g. filters, antennas, circulators, etc.) would greatly aid in the design and testing of these structures. Such detailed information can be used to reconcile discrepancies between simulated behavior and experimental data (such as scattering parameters). The near-field scanning microwave microscope we present uses a coaxial probe to provide a simple, broadband method of imaging electric fields.(S. M. Anlage, et al.) IEEE Trans. Appl. Supercond. 7, 3686 (1997).^,(See http://www.csr.umd.edu/research/hifreq/micr_microscopy.html) The signal that is measured is related to the incident electric flux normal to the face of the center conductor of the probe, allowing different components of the field to be measured by orienting the probe appropriately. By using a simple model of the system, we can also convert raw data to absolute electric field. Detailed images of standing waves on copper microstrip will be shown and compared to theory.

  11. Measurements Using a Scanning Near-Field Coaxial Probe Microwave Microscope

    Science.gov (United States)

    Steinhauer, David E.; Vlahacos, C. P.; Dutta, Sudeep; Wellstood, F. C.; Anlage, Steven M.

    1997-03-01

    We have developed a scanning near-field microwave microscope using an open-ended coaxial probe.(C. P. Vlahacos, et al.) Appl. Phys. Lett. 69, 3272 (1996)^,(S. M. Anlage, et al.) IEEE Trans. Appl. Supercond. (1997) The probe is connected to a coaxial transmission line, which acts as a resonant microwave circuit. The probe is scanned over a sample while microwave energy is fed into the other end of the coaxial line. The quantities that can be measured simultaneously during a scan are shifts in the resonant frequencies, amplitude of the resonant peaks, quality factor of the circuit, and changes in phase relative to the microwave source. We will show images and discuss the theory of how the data are related to properties of the sample.

  12. Low-temperature-compatible tunneling-current-assisted scanning microwave microscope utilizing a rigid coaxial resonator

    Science.gov (United States)

    Takahashi, Hideyuki; Imai, Yoshinori; Maeda, Atsutaka

    2016-06-01

    We present a design for a tunneling-current-assisted scanning near-field microwave microscope. For stable operation at cryogenic temperatures, making a small and rigid microwave probe is important. Our coaxial resonator probe has a length of approximately 30 mm and can fit inside the 2-in. bore of a superconducting magnet. The probe design includes an insulating joint, which separates DC and microwave signals without degrading the quality factor. By applying the SMM to the imaging of an electrically inhomogeneous superconductor, we obtain the spatial distribution of the microwave response with a spatial resolution of approximately 200 nm. Furthermore, we present an analysis of our SMM probe based on a simple lumped-element circuit model along with the near-field microwave measurements of silicon wafers having different conductivities.

  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. 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.

  15. Microwave thermal imaging of scanned focused ultrasound heating: animal experiments

    Science.gov (United States)

    Zhou, Tian; Meaney, Paul M.; Hoopes, P. Jack; Geimer, Shireen D.; Paulsen, Keith D.

    2011-03-01

    High intensity focused ultrasound (HIFU) uses focused ultrasound beams to ablate localized tumors noninvasively. Multiple clinical trials using HIFU treatment of liver, kidney, breast, pancreas and brain tumors have been conducted, while monitoring the temperature distribution with various imaging modalities such as MRI, CT and ultrasound. HIFU has achieved only minimal acceptance partially due to insufficient guidance from the limited temperature monitoring capability and availability. MR proton resonance frequency (PRF) shift thermometry is currently the most effective monitoring method; however, it is insensitive in temperature changes in fat, susceptible to motion artifacts, and is high cost. Exploiting the relationship between dielectric properties (i.e. permittivity and conductivity) and tissue temperature, in vivo dielectric property distributions of tissue during heating were reconstructed with our microwave tomographic imaging technology. Previous phantom studies have demonstrated sub-Celsius temperature accuracy and sub-centimeter spatial resolution in microwave thermal imaging. In this paper, initial animal experiments have been conducted to further investigate its potential. In vivo conductivity changes inside the piglet's liver due to focused ultrasound heating were observed in the microwave images with good correlation between conductivity changes and temperature.

  16. Nanoscale Electric Permittivity of Single Bacterial Cells at Gigahertz Frequencies by Scanning Microwave Microscopy.

    Science.gov (United States)

    Biagi, Maria Chiara; Fabregas, Rene; Gramse, Georg; Van Der Hofstadt, Marc; Juárez, Antonio; Kienberger, Ferry; Fumagalli, Laura; Gomila, Gabriel

    2016-01-26

    We quantified the electric permittivity of single bacterial cells at microwave frequencies and nanoscale spatial resolution by means of near-field scanning microwave microscopy. To this end, calibrated complex admittance images have been obtained at ∼19 GHz and analyzed with a methodology that removes the nonlocal topographic cross-talk contributions and thus provides quantifiable intrinsic dielectric images of the bacterial cells. Results for single Escherichia coli cells provide a relative electric permittivity of ∼4 in dry conditions and ∼20 in humid conditions, with no significant loss contributions. Present findings, together with the ability of microwaves to penetrate the cell membrane, open an important avenue in the microwave label-free imaging of single cells with nanoscale spatial resolution.

  17. Advanced Phase noise modeling techniques of nonlinear microwave devices

    OpenAIRE

    Prigent, M.; J. C. Nallatamby; R. Quere

    2004-01-01

    In this paper we present a coherent set of tools allowing an accurate and predictive design of low phase noise oscillators. Advanced phase noise modelling techniques in non linear microwave devices must be supported by a proven combination of the following : - Electrical modeling of low-frequency noise of semiconductor devices, oriented to circuit CAD . The local noise sources will be either cyclostationary noise sources or quasistationary noise sources. - Theoretic...

  18. Advances in Developing Transitions in Microwave Integrated Circuits

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-chuan; WANG Bing-zhong

    2005-01-01

    Advances in developing transitions in microwave integrated circuits during the last ten years are reviewed. Some typical structures of transition are introduced. Transition structures can be classified into two basic types: one is transition between the same kind of transmission lines on different planes of a common substrate, the other transition between different types of transmission lines.Furthermore, future development of transition structures is discussed.

  19. Validation of multi-channel scanning microwave radiometer on-board Oceansat-1

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Pankajakshan, T.; Harikrishnan, M.

    Sea surface temperature (SST), sea surface wind speed (WS) and columnar water vapour (WV) derived from Multi-frequency Scanning Microwave Radiometer (MSMR) sensor on-board IRS-P4 (Oceansat-1) were validated against the in situ measurements from ship...

  20. Novel Scanning Near-Field Microwave Microscopes Capable of Imaging Semiconductors and Metals

    Science.gov (United States)

    Imtiaz, Atif; Tselev, Alexander; Anlage, Steven

    2003-03-01

    To study novel physics in condensed matter and materials science, experimental techniques of probing the high frequency electrical properties of materials are limited in resolution to the wavelength of the incident electromagnetic wave. We report here a novel near-field microscope that is capable of operation at radio and microwave frequencies[1]. The spatial resolution is comparable to NSOM in the scanning capacitance mode of the microscope[2]. Our objective is to image materials contrast at microwave frequencies and improve the spatial resolution. The microscope is sensitive to losses in materials, and we will present evidence of sheet resistance contrast in a Boron-doped Silicon sample. These experiments are performed with two versions of the near-field microwave microscope: one has integrated STM-feedback for distance control and the second one maintains a constant frequency shift through Distance Following technique. We will discuss the data on these films in light of a transmission line and lumped element model of the microscope. The microscope is an attractive platform for measuring local losses and local nonlinear properties of a rich variety of semiconducting and correlated-electron materials. [1] D.E. Steinhauer, et.al, "Quantitative Imaging of Sheet Resistance with a Scanning Near-Field Microwave Microscope", Appl. Phys. Lett. 72, 861 (1998) [2] Atif Imtiaz and Steven M. Anlage, "A novel STM-assisted microwave microscope with capacitance and loss imaging capability", Ultramicroscopy (in press); cond-mat/0203540

  1. Recent Advances in Conjugated Polymer-Based Microwave Absorbing Materials

    Directory of Open Access Journals (Sweden)

    Ying Wang

    2017-01-01

    Full Text Available Microwave absorbing materials (MAMs are paving the way for exciting applications in electromagnetic (EM pollution precaution and national defense security, as they offer an advanced alternative to conventional reflection principles to fundamentally eliminate the EM waves. Conjugated polymer (CP-based composites appear as a promising kind of MAM with the desirable features of low density and high performance. In this review, we introduce the theory of microwave absorption and summarize recent advances in the fabrication of CP-based MAMs, including rational design of the microstructure of pure conjugated polymers and tunable chemical integration with magnetic ferrites, magnetic metals, transition metal oxides, and carbon materials. The key point of enhancing microwave absorption in CP-based MAMs is to regulate their EM properties, improve matching of characteristic impedance, and create diversified loss mechanisms. The examples presented in this review will provide new insights into the design and preparation of CP-based composites that can satisfy the high demands of the oncoming generation of MAMs.

  2. A Scanned Perturbation Technique For Imaging Electromagnetic Standing Wave Patterns of Microwave Cavities

    CERN Document Server

    Gokirmak, A; Bridgewater, A; Anlage, S M; Gokirmak, Ali; Wu, Dong-Ho; Anlage, Steven M.

    1998-01-01

    We have developed a method to measure the electric field standing wave distributions in a microwave resonator using a scanned perturbation technique. Fast and reliable solutions to the Helmholtz equation (and to the Schrodinger equation for two dimensional systems) with arbitrarily-shaped boundaries are obtained. We use a pin perturbation to image primarily the microwave electric field amplitude, and we demonstrate the ability to image broken time-reversal symmetry standing wave patterns produced with a magnetized ferrite in the cavity. The whole cavity, including areas very close to the walls, can be imaged using this technique with high spatial resolution over a broad range of frequencies.

  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. Advanced microwave forward model for the land surface data assimilation

    Science.gov (United States)

    Park, Chang-Hwan; Pause, Marion; Gayler, Sebastian; Wollschlaeger, Ute; Jackson, Thomas J.; LeDrew, Ellsworth; Behrendt, Andreas; Wulfmeyer, Volker

    2015-04-01

    , a significant improvement by new approach would be expected in monitoring surface runoff and infiltration, managing and improving irrigation system, and mapping and predicting flood events. Finally, the novel dielectric-mixing model is able to successfully integrate the land surface model and the dielectric constant of microwave. Radiative transfer is calculated for the bare soil and the vegetated components of the grid box using a two-stream radiative transfer model. These model characteristics provide all relevant information needed for a simulation of the microwave emission from the land surface with unprecedented realism. Noah-MP is coupled with the Weather Research and Forecasting (WRF) model system. Also, the novel dielectric-mixing model physically links the Noah-MP land surface properties and the microwave effective dielectric constant. Finally, with the existing radiative transfer model the advanced forward model can assimilate microwave brightness temperature into a consistent land-surface-atmosphere system. A case study will be provided to investigate how well the simulation of the forward model matches to the real world. L-band microwave remote-sensing measurements over the Schäfertal region in Germany have been used for this case study.

  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. Advanced on-chip divider for monolithic microwave VCO's

    Science.gov (United States)

    Peterson, Weddell C.

    1989-01-01

    High frequency division on a monolithic circuit is a critical technology required to significantly enhance the performance of microwave and millimeter-wave phase-locked sources. The approach used to meet this need is to apply circuit design practices which are essentially 'microwave' in nature to the basically 'digital' problem of high speed division. Following investigation of several promising circuit approaches, program phase 1 culminated in the design and layout of an 8.5 GHz (Deep Space Channel 14) divide by four circuit based on a dynamic mixing divider circuit approach. Therefore, during program phase 2, an 8.5 GHz VCO with an integral divider which provides a phase coherent 2.125 GHz reference signal for phase locking applications was fabricated and optimized. Complete phase locked operation of the monolithic GaAs devices (VCO, power splitter, and dynamic divider) was demonstrated both individually and as an integrated unit. The fully functional integrated unit in a suitable test fixture was delivered to NASA for engineering data correlation. Based on the experience gained from this 8.5 GHz super component, a monolithic GaAs millimeter-wave dynamic divider for operation with an external VCO was also designed, fabricated, and characterized. This circuit, which was also delivered to NASA, demonstrated coherent division by four at an input frequency of 24.3 GHz. The high performance monolithic microwave VCO with a coherent low frequency reference output described in this report and others based on this technology will greatly benefit advanced communications systems in both the DoD and commercial sectors. Signal processing and instrumentation systems based on phase-locking loops will also attain enhanced performance at potentially reduced cost.

  7. Advanced on-chip divider for monolithic microwave VCO's

    Science.gov (United States)

    Peterson, Weddell C.

    1989-05-01

    High frequency division on a monolithic circuit is a critical technology required to significantly enhance the performance of microwave and millimeter-wave phase-locked sources. The approach used to meet this need is to apply circuit design practices which are essentially 'microwave' in nature to the basically 'digital' problem of high speed division. Following investigation of several promising circuit approaches, program phase 1 culminated in the design and layout of an 8.5 GHz (Deep Space Channel 14) divide by four circuit based on a dynamic mixing divider circuit approach. Therefore, during program phase 2, an 8.5 GHz VCO with an integral divider which provides a phase coherent 2.125 GHz reference signal for phase locking applications was fabricated and optimized. Complete phase locked operation of the monolithic GaAs devices (VCO, power splitter, and dynamic divider) was demonstrated both individually and as an integrated unit. The fully functional integrated unit in a suitable test fixture was delivered to NASA for engineering data correlation. Based on the experience gained from this 8.5 GHz super component, a monolithic GaAs millimeter-wave dynamic divider for operation with an external VCO was also designed, fabricated, and characterized. This circuit, which was also delivered to NASA, demonstrated coherent division by four at an input frequency of 24.3 GHz. The high performance monolithic microwave VCO with a coherent low frequency reference output described in this report and others based on this technology will greatly benefit advanced communications systems in both the DoD and commercial sectors. Signal processing and instrumentation systems based on phase-locking loops will also attain enhanced performance at potentially reduced cost.

  8. Correlations between Nimbus-7 Scanning Multichannel Microwave Radiometer data and an antecedent precipitation index

    Science.gov (United States)

    Wilke, G. D.; Mcfarland, M. J.

    1986-01-01

    Passive microwave brightness temperatures from the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) can be used to infer the soil moisture content over agricultural areas such as the southern Great Plains of the United States. A linear regression analysis between three transforms of the five dual polarized SMMR wavelengths of 0.81, 1.36, 1.66, 2.80 and 4.54 cm and an antecedent precipitation index representing the precipitation history showed correlation coefficients greater than 0.90 for pixel aggregates of 25-50 km. The use of surface air temperatures to approximate the temperature of the emitting layer was not required to obtain high correlation coefficients between the transforms and the antecedent precipitation index.

  9. 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.

  10. 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.

  11. Theory and operation of a near-field scanning microwave microscope

    Science.gov (United States)

    Vlahacos, C. P.; Steinhauer, David E.; Dutta, S.; Anlage, S. M.; Wellstood, F. C.; Newman, H.

    1997-03-01

    We will describe the operation and capabilities of a near-field microwave microscope with a spatial resolution of 10-100 μm in the frequency range 7.5-12.4 GHz.(C. P. Vlahacos, et al.), Appl. Phys. Lett. 69, 3272 (1996).^,(S. M. Anlage, et al.), IEEE Trans. Appl. Supercond. (1997) The microscope consists of a resonant section of a coaxial cable which is terminated with a small-diameter open-ended coaxial probe. Images are made by scanning the sample under the probe while recording the signal collected in the near-field as a function of sample position. Images can be made of fields produced by a powered circuit or of sample properties such as topography, dielectric constant and loss. To illustrate the operation of the system, images will be presented of microwave devices, such as a planar ferrite microwave circulator and a high-temperature superconducting microstrip YBa_2Cu_3O_7-δ resonator.

  12. Nimbus-7 scanning multichannel microwave radiometer /SMMR/ in-orbit performance appraisal

    Science.gov (United States)

    Gloersen, P.; Cavalieri, D. J.; Gatlin, J. A.

    1981-01-01

    Calibration and processing techniques enacted during first year of operation of the Nimbus-7 scanning multichannel microwave radiometer (SMMR) are described. It was found that in-orbit calibration was necessary, as was fine-tuning of the geophysical parameter retrieval parameters to account for anomalies such as lower-than-expected polarization differences in ocean radiances. Phase shifts in the scan angles were corrected in order to avoid polarization mixing. Calibration constants to eliminate cross-talk and phase shift effects were established for radiation reflected from the earth, then averaged over data from 300 orbits to fit points on a sine curve to better than 0.2 K accuracy. An iterative approach was determined to be necessary due to signal anomalies caused by antenna dish oscillations. Global ocean and atmosphere parameters used to construct a radiation model of ten latitude bands are presented for use in radiation transfer equations.

  13. Advances in Satellite Microwave Precipitation Retrieval Algorithms Over Land

    Science.gov (United States)

    Wang, N. Y.; You, Y.; Ferraro, R. R.

    2015-12-01

    Precipitation plays a key role in the earth's climate system, particularly in the aspect of its water and energy balance. Satellite microwave (MW) observations of precipitation provide a viable mean to achieve global measurement of precipitation with sufficient sampling density and accuracy. However, accurate precipitation information over land from satellite MW is a challenging problem. The Goddard Profiling Algorithm (GPROF) algorithm for the Global Precipitation Measurement (GPM) is built around the Bayesian formulation (Evans et al., 1995; Kummerow et al., 1996). GPROF uses the likelihood function and the prior probability distribution function to calculate the expected value of precipitation rate, given the observed brightness temperatures. It is particularly convenient to draw samples from a prior PDF from a predefined database of observations or models. GPROF algorithm does not search all database entries but only the subset thought to correspond to the actual observation. The GPM GPROF V1 database focuses on stratification by surface emissivity class, land surface temperature and total precipitable water. However, there is much uncertainty as to what is the optimal information needed to subset the database for different conditions. To this end, we conduct a database stratification study of using National Mosaic and Multi-Sensor Quantitative Precipitation Estimation, Special Sensor Microwave Imager/Sounder (SSMIS) and Advanced Technology Microwave Sounder (ATMS) and reanalysis data from Modern-Era Retrospective Analysis for Research and Applications (MERRA). Our database study (You et al., 2015) shows that environmental factors such as surface elevation, relative humidity, and storm vertical structure and height, and ice thickness can help in stratifying a single large database to smaller and more homogeneous subsets, in which the surface condition and precipitation vertical profiles are similar. It is found that the probability of detection (POD) increases

  14. Direct observation of mesoscopic phase separation in KxFeySe2 by scanning microwave microscopy

    Science.gov (United States)

    Maeda, Atsutaka; Takahashi, Hideyuki; Imai, Yoshinori

    2015-03-01

    KxFeySe2 is isostructural to 122-FeAs compounds. However, its electronic structure is unique among Fe-based superconductors in the sense that hole Fermi pocket is absent at the center of the Brillouin zone. Therefore, it is important to study this compounds in terms of the mechanism of superconductivity since some pairing (for example, s +/- -wave) needs the interaction between hole and electron Fermi pockets. However, the phase separation in this material makes studies using conventional macroscopic measurement techniques very difficult. Scanning near-field microwave microscope (SMM), which can measure local electric property of inhomogeneous conducting samples, should be a powerful tool. Recently we developed the combined instrument of STM and SMM with high sensitivity, and investigated the local electric property of KxFeySe2 (x = 0.8, y = 1.6 ~2, Tc = 31 K) using this scanning tunneling/microwave microscope. The characteristic pattern of mesoscopic phase separation of the metallic and the semiconducting phase was observed. From the comparison with previously reported SEM/EDS result we identified the metallic phase and the semiconducting phase as the minor Fe-rich phase and the major K2Fe4Se5 phase, respectively.

  15. 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.

  16. 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.

  17. Impact of advanced technology microwave sounder data in the NCMRWF 4D-VAR data assimilation system

    Science.gov (United States)

    Rani, S. Indira; Srinivas, D.; Mallick, Swapan; George, John P.

    2016-05-01

    This study demonstrates the added benefits of assimilating the Advanced Technology Microwave Sounder (ATMS) radiances from the Suomi-NPP satellite in the NCMRWF Unified Model (NCUM). ATMS is a cross-track scanning microwave radiometer inherited the legacy of two very successful instrument namely, Advanced Microwave Sounding Unit-A (AMSU-A) and Microwave Humidity Sounder (MHS). ATMS has 22 channels: 11 temperature sounding channels around 50-60 GHz oxygen band and 6 moisture sounding channels around the 183GHz water vapour band in addition to 5 channels sensitive to the surface in clear conditions, or to water vapour, rain, and cloud when conditions are not clear (at 23, 31, 50, 51 and 89 GHz). Before operational assimilation of any new observation by NWP centres it is standard practice to assess data quality with respect to NWP model background (short-forecast) fields. Quality of all channels is estimated against the model background and the biases are computed and compared against that from the similar observations. The impact of the ATMS data on global analyses and forecasts is tested by adding the ATMS data in the NCUM Observation Processing system (OPS) and 4D-Var variational assimilation (VAR) system. This paper also discusses the pre-operational numerical experiments conducted to assess the impact of ATMS radiances in the NCUM assimilation system. It is noted that the performance of ATMS is stable and it contributes to the performance of the model, complimenting observations from other instruments.

  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. 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

  20. Perturbative scanning probe microscopy on a Kagome lattice of superconducting microwave resonators

    Science.gov (United States)

    Underwood, Devin; Shanks, Will; Li, Andy C. Y.; Koch, Jens; Houck, Andrew

    2015-03-01

    Microwave photons confined to a lattice of coupled resonators, each coupled to its own superconducting qubit have been predicted to exhibit matter like quantum phases. Realizing such a lattice-based quantum simulator presents a daunting experimental challenge; as such, new tools and measurement techniques are a necessary precursor. Here, we present measurements of the internal mode structure of microwave photons on a 49-site Kagome lattice of capacitively coupled coplanar waveguide resonators without qubits. By scanning a probe with a sapphire tip over the surface of a single lattice site, the resonant frequency was detuned, thus forming a local defect in the lattice. This perturbation resulted in measurable shifts in the lattice spectrum, which were used to extract the mode weights at the perturbed site. By perturbing each lattice site it was possible to reconstruct a complete map of different normal mode weights within the entire lattice. Additionally we present experimental evidence of a frustrated flat band that arises from the Kagome lattice geometry.

  1. 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.

  2. Imaging the p-n junction in a gallium nitride nanowire with a scanning microwave microscope

    Energy Technology Data Exchange (ETDEWEB)

    Imtiaz, Atif [Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Wallis, Thomas M.; Brubaker, Matt D.; Blanchard, Paul T.; Bertness, Kris A.; Sanford, Norman A.; Kabos, Pavel, E-mail: kabos@boulder.nist.gov [Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Weber, Joel C. [Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Coakley, Kevin J. [Information Technology Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

    2014-06-30

    We used a broadband, atomic-force-microscope-based, scanning microwave microscope (SMM) to probe the axial dependence of the charge depletion in a p-n junction within a gallium nitride nanowire (NW). SMM enables the visualization of the p-n junction location without the need to make patterned electrical contacts to the NW. Spatially resolved measurements of S{sub 11}{sup ′}, which is the derivative of the RF reflection coefficient S{sub 11} with respect to voltage, varied strongly when probing axially along the NW and across the p-n junction. The axial variation in S{sub 11}{sup ′}  effectively mapped the asymmetric depletion arising from the doping concentrations on either side of the junction. Furthermore, variation of the probe tip voltage altered the apparent extent of features associated with the p-n junction in S{sub 11}{sup ′} images.

  3. Microwave Processing of Simulated Advanced Nuclear Fuel Pellets

    Energy Technology Data Exchange (ETDEWEB)

    D.E. Clark; D.C. Folz

    2010-08-29

    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.

  4. Near-field Microwave Scanning Probe Imaging of Conductivity Inhomogeneities in CVD Graphene

    Energy Technology Data Exchange (ETDEWEB)

    Tselev, Alexander [ORNL; Lavrik, Nickolay V [ORNL; Vlassiouk, Ivan V [ORNL; Briggs, Dayrl P [ORNL; Rutgers, Maarten [Asylum Research, Santa Barbara, CA; Proksch, Roger [Asylum Research, Santa Barbara, CA; Kalinin, Sergei V [ORNL

    2012-01-01

    We have performed near-field scanning microwave microscopy (SMM) of graphene grown by chemical vapor deposition. Due to the use of probe-sample capacitive coupling and a relatively high ac frequency of a few GHz, this scanning probe method allows mapping of local conductivity without a dedicated counter electrode, with a spatial resolution of about 50 nm. Here, the coupling was enabled by atomic layer deposition of alumina on top of graphene, which in turn enabled imaging both large-area films, as well as micron-sized islands, with a dynamic range covering a low sheet resistance of a metal film and a high resistance of highly disordered graphene. The structures of graphene grown on Ni films and Cu foils are explored, and the effects of growth conditions are elucidated. We present a simple general scheme for interpretation of the contrast in the SMM images of our graphene samples and other two-dimensional conductors, which is supported by extensive numerical finite-element modeling. We further demonstrate that combination of the SMM and numerical modeling allows quantitative information about the sheet resistance of graphene to be obtained, paving the pathway for characterization of graphene conductivity with a sub-100 nm special resolution.

  5. 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...

  6. 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

  7. Magnetic Permeability Imaging of Metals with a Scanning Near-Field Microwave Microscope

    Science.gov (United States)

    Lee, Sheng-Chiang; Vlahacos, C. P.; Feenstra, B. J.; Schwartz, Andrew; Steinhauer, David; Wellstood, Fredrick; Anlage, Steven

    2001-03-01

    We extended the use of our scanning near-field microwave microscope to measure the local magnetic properties of metallic samples in a spatially-resolved manner. We use a small loop probe to detect magnetic perturbations in thin film and bulk samples. We demonstrate qualitative and quantitative understanding of permeability imaging through spatially-resolved ferromagnetic resonance experiments on a single crystal of the colossal magneto-resistive material La_0.8Sr_0.2MnO_3. The experimental results are well described by a simple model of the system. We also modified this microscope to image the ferromagnetic resonance field over a ferromagnetic sample in the presence of external magnetic field. The spatial resolution is on the order of the size of the loop, currently 200 μ m. Results demonstrating FMR imaging on La_0.8Sr_0.2MnO3 and amorphous magnetic tapes will be presented. Reference: S.C. Lee, C P. Vlahacos, B. J. Feenstra, Andrew Schwartz, D. E. Steinhauer, F. C. Wellstood, and Steve M. Anlage, Appl. Phys. Lett., December 18 (2000)

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

    Institute of Scientific and Technical Information of China (English)

    Zhao Lixin; Jin Zhi; Liu Xinyu

    2009-01-01

    In wireless mobile communications and wireless local area networks (WLAN), advanced lnGaP 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.

  9. Advanced Microwave Ferrite Research (AMFeR): Phase Two

    Science.gov (United States)

    2006-12-31

    sources, such as a klystron or a Gunn diode . The waveguide system involves two coax-to-waveguide adaptors, a directional coupler, a waveguide short...or Gunn Diode » Microwave Source Isolator HP8350B Sweeper> upto 20 Ghz waveguide 1 Directional to Type N Coupler Coax Adator < Scalar Netw~ork...two isolators, one standard un-calibrated diode detector, and one calibrated detector for the network analyzer. The magnetic sample is mounted on the

  10. Development of near-field scanning microwave and optical dual probe: Application to characterization of high-T(c) superconductors

    Science.gov (United States)

    Aga, Roberto Sabas, Jr.

    In this dissertation, a novel dual-channel near-field scanning microwave and optical microprobe (NSMM/NSOM) was developed for simultaneous mapping of microwave and optical properties of a sample at microscopic scales. This microprobe is composed of an open-end coaxial resonator with its center conductor being replaced by a stainless steel tube terminated by a titanium/silver coated fiber optic with a tapered tip. The optical fiber serves as the channel for NSOM, while its metal coating is the channel for NSMM. Using this dual-channel NSMM/NSOM probe, a spatial resolution of ˜5 mum, that is comparable to the best reported for single-channel NSMM, has been achieved on metallic samples. This resolution is mainly limited by the sensitivity of the NSMM channel and may be further improved when the sensitivity of NSMM is enhanced. Characterization of the microwave properties of the highest-Tc Hg-based superconductors has been carried out using a traditional resonant cavity technique, as well as a novel single-channel NSMM and the dual-channel NSMM/NSOM. Using the traditional technique, the microwave surface resistance (Rs) and power handling capability (Pc) of HgBa 2CaCu2O6 (Hg-1212 with Tc ˜ 125 K) films have been measured for the first time, and the results are superior to the best achieved on other superconductors. For example, a comparable R s ˜ 0.3 mO (10 GHz) can be obtained on Hg-1212 at close to 120 K as opposed to the same Rs for YBa2Cu3O 7 (the most popular high-Tc superconductor with Tc ˜ 92 K) at around 77K. This can be attributed to the large difference in the Tcs between the two materials and has demonstrated the potential of Hg-1212 for microwave applications. A comparison of the microwave properties of Hg-1212, Tl-2212 and YBCO films at reduced temperature scale suggested further room for improvement of Hg-1212 performance. Using NSMM, the localized microwave properties, such as Tcs, sheet resistance and power handling capability have been investigated

  11. New NOAA-15 Advanced Microwave Sounding Unit (AMSU) Datasets for Stratospheric Research

    Science.gov (United States)

    Spencer, Roy W.; Braswell, William D.

    1999-01-01

    The NOAA-15 spacecraft launched in May 1998 carried the first Advanced Microwave Sounding Unit (AMSU). The AMSU has eleven oxygen absorption channels with weighting functions peaking from near the surface to 2 mb. Twice-daily, limb-corrected I degree gridded datasets of layer temperatures have been constructed since the AMSU went operational in early August 1998. Examples of AMSU imagery will be shown, as will preliminary analyses of daily fluctuations in tropical stratospheric temperatures and their relationship to daily variations in tropical-average rainfall measured by the Special Sensor Microwave Imager (SSM/I). The AMSU datasets are now available for other researchers to utilize.

  12. Small Cavity Nonresonant Tunable Microwave-Frequency Alternating Current Scanning Tunneling Microscope

    Science.gov (United States)

    1994-10-10

    Optical Components, Vol. 1, K. Chang, ed. (John Wiley, New York, 1989), pp. 60-117. 32. The ARRL Handbook for Radio Amateurs, 70t ed. (The American Radio...H. W. Jamieson and T. E. Robbins, Proc. IRE, 32, 695 (1944); N. Marcuvitz, ed., Waveguide Handbook (McGraw-Hill, New York, 1951); T. S. Saad, ed...Microwave Engineer’s Handbook Vol. 1, (Artech House, Dedham, 1971); K. C. Gupta, "Transmission-Line Discontinuities," in Handbook of Microwave and

  13. 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...

  14. 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.

  15. Quantitative Imaging of Surface Resistance and Electric Fields by Scanning Near-Field Microwave Microscopy (SNFiMM)^1

    Science.gov (United States)

    Feenstra, B. J.

    1998-03-01

    After a brief survey and an introduction to the field of microwave microscopy, our novel scanning near-field microwave microscope (SNFiMM) based on a resonant coaxial cable will be described. Using this system we have imaged dielectric and conducting properties and electromagnetic fields on length scales far smaller than the free space wavelength of the radiation.(C. P. Vlahacos, R. C. Black, S. M. Anlage, A. Amar, and F. C. Wellstood, Appl. Phys. Lett. 69), 3272 (1996). Some of the merits of SNFiMM are the simplicity of its construction, the broad frequency coverage, ranging from 0.15 to 50 GHz, and the ability to alternate easily between different modes (reflection, receiving, frequency following etc.). The versatility of the system will be illustrated through images of the absolute sheet resistance and absolute electric fields, measured on a μm length scale.(D. E. Steinhauer, C. P. Vlahacos, S. K. Dutta, F. C. Wellstood, and Steven M. Anlage, Appl. Phys. Lett 71), 1736 (1997). In addition, potential applications will be discussed, including the use of SNFiMM for the diagnostics of active microwave circuits, both at room and cryogenic temperatures.

  16. NOAA Climate Data Record (CDR) of Advanced Microwave Sounding Unit (AMSU)-A Brightness Temperature, Version 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Climate Data Record (CDR) for Advanced Microwave Sounding Unit-A (AMSU-A) brightness temperature in "window channels". The data cover a time period from...

  17. 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

    2016-06-07

    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.

  18. A Novel Scanning Near-Field Microwave Microscope Capable of High Resolution Loss Imaging

    Science.gov (United States)

    Imtiaz, Atif

    2005-03-01

    To study novel physics in condensed matter and materials science, experimental techniques need to be pushed for better sensitivity and higher spatial resolution. Classical techniques of probing the high frequency electrical properties of materials are limited in resolution to the wavelength of the incident electromagnetic wave. We report here a novel near-field microwave microscope to image materials contrast, with 2.5 nm spatial resolution in capacitance. Our objective is to improve the spatial resolution in local loss imaging. We will present evidence of sheet resistance contrast in a Boron-doped Silicon sample on sub- micron length scales. We will present quantitative analysis of the data on the Boron-doped Silicon sample in light of evanescent wave model of the microscope that we have developed. In addition, the probe to sample interaction on nanometer length scales will be discussed [1]. This work has been supported by an NSF IMR Grant DMR-9802756, and the University of Maryland/Rutgers NSF-MRSEC through the Near Field Microwave Microscope Shared Experimental Facility Grant DMR-00-80008. [1] Atif Imtiaz, Marc Pollak, Steven M. Anlage, John D. Barry and John Melngailis, ``Near-Field Microwave Microscopy on nanometer length scales'', to be published in J. Appl. Phys. (Feb. 1, 2005).

  19. 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...

  20. Earth resources programs at the Langley Research Center. Part 1: Advanced Applications Flight Experiments (AAFE) and microwave remote sensing program

    Science.gov (United States)

    Parker, R. N.

    1972-01-01

    The earth resources activity is comprised of two basic programs as follows: advanced applications flight experiments, and microwave remote sensing. The two programs are in various stages of implementation, extending from experimental investigations within both the AAFE program and the microwave remote sensing program, to multidisciplinary studies and planning. The purpose of this paper is simply to identify the main thrust of the Langley Research Center activity in earth resources.

  1. Treatment of dairy manure using the microwave enhanced advanced oxidation process under a continuous mode operation.

    Science.gov (United States)

    Yu, Yang; Lo, Ing W; Liao, Ping H; Lo, Kwang V

    2010-11-01

    The microwave enhanced advanced oxidation process (MW/H(2)O(2)-AOP) was used to treat dairy manure for solubilization of nutrients and organic matters. This study investigated the effectiveness of the MW/H(2)O(2)-AOP under a continuous mode of operation, and compared the results to those of batch operations. The main factors affecting solubilization by the MW/H(2)O(2)-AOP were heating temperature and hydrogen peroxide dosage. Soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) increased with an increase of microwave (MW) heating temperature; very high concentrations were obtained at 90°C. Insignificant amounts of ammonia and reducing sugars were released in all runs. An acidic pH condition was required for phosphorus solubilisation from dairy manure. The best yield was obtained at 90°C with an acid dosage of 1.0 %; about 92 % of total phosphorus and 90 % of total chemical oxygen demand were in the soluble forms. The MW/H(2)O(2)-AOP operated in a continuous operation mode showed pronounced synergistic effects between hydrogen peroxide and microwave irradiation when compared to a batch system under similar operating conditions, resulting in much better yields.

  2. Inspection results of advanced (sub-50nm design rule) reticles using the TeraScanHR

    Science.gov (United States)

    Sier, Jean-Paul; Broadbent, William; Yu, Paul

    2008-04-01

    Results from the recently available TeraScanHR reticle inspection system were published in early 2007. These results showed excellent inspection capability for 45nm logic and 5xnm half-pitch memory advanced production reticles, thus meeting the industry need for the mid-2007 start of production. The system has been in production use since that time. In early 2007, some evidence was shown of capability to inspect reticles for 32nm logic and sub-50nm half-pitch memory, but the results were incomplete due to the limited availability of such reticles. However, more of these advanced reticles have become available since that time. In this paper, inspection results of these advanced reticles from various leading-edge reticle manufacturers using the TeraScanHR are shown. These results indicate that the system has the capability to provide the needed inspection sensitivity for continued development work to support the industry roadmap.

  3. Advances in gallium arsenide monolithic microwave integrated-circuit technology for space communications systems

    Science.gov (United States)

    Bhasin, K. B.; Connolly, D. J.

    1986-01-01

    Future communications satellites are likely to use gallium arsenide (GaAs) monolithic microwave integrated-circuit (MMIC) technology in most, if not all, communications payload subsystems. Multiple-scanning-beam antenna systems are expected to use GaAs MMIC's to increase functional capability, to reduce volume, weight, and cost, and to greatly improve system reliability. RF and IF matrix switch technology based on GaAs MMIC's is also being developed for these reasons. MMIC technology, including gigabit-rate GaAs digital integrated circuits, offers substantial advantages in power consumption and weight over silicon technologies for high-throughput, on-board baseband processor systems. In this paper, current developments in GaAs MMIC technology are described, and the status and prospects of the technology are assessed.

  4. Treating solid dairy manure using microwave-enhanced advanced oxidation process.

    Science.gov (United States)

    Kenge, Anju A; Liao, Ping H; Lo, Kwang V

    2009-08-01

    The microwave enhanced advanced oxidation process (MW/H(2)O(2)-AOP) was used to treat separated solid dairy manure for nutrient release and solids reduction. The MW/H(2)O(2)-AOP was conducted at a microwave temperature of 120 degrees C for 10 minutes, and at three pH conditions of 3.5, 7.3 and 12. The hydrogen peroxide dosage at approximately 2 mL per 1% TS for a 30 mL sample was used in this study, reflecting a range of 0.53-0.75 g H(2)O(2)/g dry sludge. The results indicated that substantial quantities of nutrients could be released into the solution at pH of 3.5. However, at neutral and basic conditions only volatile fatty acids and soluble chemical oxygen demand could be released. The analyses on orthophosphate, soluble chemical oxygen demands and volatile fatty acids were re-examined for dairy manure. It was found that the orthophosphate concentration for untreated samples at a higher % total solids (TS) was suppressed and lesser than actual. To overcome this difficulty, the initial orthophosphate concentration had to be measured at 0.5% TS.

  5. Microwave enhanced advanced oxidation process for treating dairy manure at low pH.

    Science.gov (United States)

    Lo, Kwang V; Chan, Winnie W I; Yawson, Selina K; Liao, Ping H

    2012-01-01

    This study investigated the treatment of dairy manure using the microwave enhanced advanced oxidation process (MW-AOP) at pH 2. An experimental design was developed based on a statistical program using response surface methodology to explore the effects of temperature, hydrogen peroxide dosage and heating time on sugar production, nutrient release and solids destruction. Temperature, hydrogen peroxide dosage and acid concentration were key factors affecting reducing sugar production. The highest reducing sugar yield of 7.4% was obtained at 160°C, 0 mL, 15 min heating time, and no H(2)O(2) addition. Temperature was a dominant factor for an increase of soluble chemical oxygen demand (SCOD) in the treated dairy manure. The important factors for volatile fatty acids (VFA) production were microwave temperature and hydrogen peroxide dosage. Temperature was the most important parameter, and heating time, to a lesser extent affecting orthophosphate release. Heating time, hydrogen peroxide dosage and temperature were significant factors for ammonia release. There was a maximum of 96% and 196% increase in orthophosphate and ammonia concentration, respectively at 160°C, 0.5 mL H(2)O(2) and 15 min heating time. The MW-AOP is an effective method in dairy manure treatment for sugar production, nutrient solubilisation, and solids disintegration.

  6. 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.

  7. Velocity profiles inside volcanic clouds from three-dimensional scanning microwave dual-polarization Doppler radars

    Science.gov (United States)

    Montopoli, Mario

    2016-07-01

    In this work, velocity profiles within a volcanic tephra cloud obtained by dual-polarization Doppler radar acquisitions with three-dimensional (3-D) mechanical scanning capability are analyzed. A method for segmenting the radar volumes into three velocity regimes: vertical updraft, vertical fallout, and horizontal wind advection within a volcanic tephra cloud using dual-polarization Doppler radar moments is proposed. The horizontal and vertical velocity components within the regimes are retrieved using a novel procedure that makes assumptions concerning the characteristics of the winds inside these regimes. The vertical velocities retrieved are combined with 1-D simulations to derive additional parameters including particle fallout, mass flux, and particle sizes. The explosive event occurred on 23 November 2013 at the Mount Etna volcano (Sicily, Italy), is considered a demonstrative case in which to analyze the radar Doppler signal inside the tephra column. The X-band radar (3 cm wavelength) in the Catania, Italy, airport observed the 3-D scenes of the Etna tephra cloud ~32 km from the volcano vent every 10 min. From the radar-derived vertical velocity profiles of updraft, particle fallout, and horizontal transportation, an exit velocity of 150 m/s, mass flux rate of 1.37 • 107 kg/s, particle fallout velocity of 18 m/s, and diameters of precipitating tephra particles equal to 0.8 cm are estimated on average. These numbers are shown to be consistent with theoretical 1-D simulations of plume dynamics and local reports at the ground, respectively. A thickness of 3 ± 0.36 km for the downwind ash cloud is also inferred by differentiating the radar-derived cloud top and the height of transition between the convective and buoyancy regions, the latter being inferred by the estimated vertical updraft velocity profile. The unique nature of the case study as well as the novelty of the segmentation and retrieval methods presented potentially give new insights into the

  8. Simultaneously imaging of dielectric properties and topography in a PbTiO_3 crystal by near-field scanning microwave microscopy

    OpenAIRE

    Wang, Y.G.; Reeves, M. E.; Rachford, F. J.

    2000-01-01

    We use a near-field scanning microwave microscope to simultaneously image the dielectric constant, loss tangent, and topography in a PbTiO_3 crystal. By this method, we study the effects of the local dielectric constant and loss tangent in the geometry of periodic domains on the measured resonant frequency, and quality factor. We also carry out theoretical calculations and the results agree well with the experimental data and reveal the anisotropic nature of dielectric constant.

  9. Advanced three-dimensional scan methods in the nanopositioning and nanomeasuring machine

    Science.gov (United States)

    Hausotte, T.; Percle, B.; Jäger, G.

    2009-08-01

    The nanopositioning and nanomeasuring machine developed at the Ilmenau University of Technology was originally designed for surface measurements within a measuring volume of 25 mm × 25 mm × 5 mm. The interferometric length measuring and drive systems make it possible to move the stage with a resolution of 0.1 nm and a positioning uncertainty of less than 10 nm in all three axes. Various measuring tasks are possible depending on the installed probe system. Most of the sensors utilized are one-dimensional surface probes; however, some tasks require measuring sidewalls and other three-dimensional features. A new control system, based on the I++ DME specification, was implemented in the device. The I++ DME scan functions were improved and special scan functions added to allow advanced three-dimensional scan methods, further fulfilling the demands of scanning force microscopy and micro-coordinate measurements. This work gives an overview of these new functions and the application of them for several different measurements.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kasper, M. [Christian Doppler Laboratory for Nanoscale Methods in Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz (Austria); Gramse, G. [Biophysics Institute, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz (Austria); Hoffmann, J. [METAS, National Metrology Institute of Switzerland, Lindenweg 50, 3003 Bern-Wabern (Switzerland); Gaquiere, C. [MC2 technologies, 5 rue du Colibri, 59650 Villeneuve D' ascq (France); Feger, R.; Stelzer, A. [Institute for Communications Engineering and RF-Systems, Johannes Kepler University, Altenberger Str. 69, 4040 Linz (Austria); Smoliner, J. [Vienna University of Technology, Institute for Solid State Electronics, Floragasse 7, 1040 Vienna (Austria); Kienberger, F., E-mail: ferry-kienberger@keysight.com [Keysight Technologies Austria, Measurement Research Lab, Gruberstrasse 40, 4020 Linz (Austria)

    2014-11-14

    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/C{sup 2} 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.

  11. Recent advancements in nanoelectrodes and nanopipettes used in combined scanning electrochemical microscopy techniques.

    Science.gov (United States)

    Kranz, Christine

    2014-01-21

    In recent years, major developments in scanning electrochemical microscopy (SECM) have significantly broadened the application range of this electroanalytical technique from high-resolution electrochemical imaging via nanoscale probes to large scale mapping using arrays of microelectrodes. A major driving force in advancing the SECM methodology is based on developing more sophisticated probes beyond conventional micro-disc electrodes usually based on noble metals or carbon microwires. This critical review focuses on the design and development of advanced electrochemical probes particularly enabling combinations of SECM with other analytical measurement techniques to provide information beyond exclusively measuring electrochemical sample properties. Consequently, this critical review will focus on recent progress and new developments towards multifunctional imaging.

  12. 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...

  13. 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.

  14. Advanced fabrication process for combined atomic force-scanning electrochemical microscopy (AFM-SECM) probes.

    Science.gov (United States)

    Eifert, Alexander; Mizaikoff, Boris; Kranz, Christine

    2015-01-01

    An advanced software-controlled focused ion beam (FIB) patterning process for the fabrication of combined atomic force-scanning electrochemical microscopy (AFM-SECM) probes is reported. FIB milling is a standard process in scanning probe microscopy (SPM) for specialized SPM probe fabrication. For AFM-SECM, milling of bifunctional probes usually requires several milling steps. Milling such complex multi-layer/multi-material structures using a single milling routine leads to significantly reduced fabrication times and costs. Based on an advanced patterning routine, a semi-automated FIB milling routine for fabricating combined AFM-SECM probes with high reproducibility is presented with future potential for processing at a wafer level. The fabricated bifunctional probes were electrochemically characterized using cyclic voltammetry, and their performance for AFM-SECM imaging experiments was tested. Different insulation materials (Parylene-C and SixNy) have been evaluated with respect to facilitating the overall milling process, the influence on the electrochemical behavior and the long-term stability of the obtained probes. Furthermore, the influence of material composition and layer sequence to the overall shape and properties of the combined probes were evaluated.

  15. 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).

  16. Optimal Use of Space-Borne Advanced Infrared and Microwave Soundings for Regional Numerical Weather Prediction

    Directory of Open Access Journals (Sweden)

    Chian-Yi Liu

    2016-09-01

    Full Text Available Satellite observations can either be assimilated as radiances or as retrieved physical parameters to reduce error in the initial conditions used by the Numerical Weather Prediction (NWP model. Assimilation of radiances requires a radiative transfer model to convert atmospheric state in model space to that in radiance space, thus requiring a lot of computational resources especially for hyperspectral instruments with thousands of channels. On the other hand, assimilating the retrieved physical parameters is computationally more efficient as they are already in thermodynamic states, which can be compared with NWP model outputs through the objective analysis scheme. A microwave (MW sounder and an infrared (IR sounder have their respective observational limitation due to the characteristics of adopted spectra. The MW sounder observes at much larger field-of-view (FOV compared to an IR sounder. On the other hand, MW has the capability to reveal the atmospheric sounding when the clouds are presented, but IR observations are highly sensitive to clouds, The advanced IR sounder is able to reduce uncertainties in the retrieved atmospheric temperature and moisture profiles due to its higher spectral-resolution than the MW sounder which has much broader spectra bands. This study tries to quantify the optimal use of soundings retrieved from the microwave sounder AMSU and infrared sounder AIRS onboard the AQUA satellite in the regional Weather and Research Forecasting (WRF model through three-dimensional variational (3D-var data assimilation scheme. Four experiments are conducted by assimilating soundings from: (1 clear AIRS single field-of-view (SFOV; (2 retrieved from using clear AMSU and AIRS observations at AMSU field-of-view (SUP; (3 all SFOV soundings within AMSU FOVs must be clear; and (4 SUP soundings which must have all clear SFOV soundings within the AMSU FOV. A baseline experiment assimilating only conventional data is generated for comparison

  17. 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。

  18. Advances in Research on Soil Moisture by Microwave Remote Sensing in China

    Institute of Scientific and Technical Information of China (English)

    SONG Dongsheng; ZHAO Kai; GUAN Zhi

    2007-01-01

    Soil moisture is an important factor in global hydrologic circulation and plays a significant role in the research of hydrology, climatology, and agriculture. Microwave remote sensing is less limited by climate and time, and can measure in large scale. With these characteristics, this technique becomes an effective tool to measure soil moisture. Since the 1980s, Chinese researchers have investigated the soil moisture using microwave instruments. The active remote sensors are characteristic of high spatial resolution, thus with launch of a series of satellites, active microwave remote sensing of soil moisture will be emphasized. The passive microwave remote sensing of soil moisture has a long research history, and its retrieval algorithms were developed well, so it is an important tool to retrieve large scale moisture information from satellite data in the future.

  19. 山区地形对被动微波遥感影响的研究进展%Advances in the Study of Mountainous Relief Effects on Passive Microwave Remote Sensing

    Institute of Scientific and Technical Information of China (English)

    李欣欣; 张立新; 蒋玲梅

    2011-01-01

    随着土壤湿度与海水盐度卫星( SMOS)发射计划的顺利开展和AMSR -E(Advanced Microwave Scanning Radiometer- Earth Observing System)业务化运行服务之后,人类用星载微波辐射计监测土壤水分是空间技术上的又一次飞跃,但土壤水分的反演精度受到微波辐射计低空间分辨率观测像元的空间异质性和地形的影响,尤其山区地形对大尺度被动微波遥感观测影响显著,其中包括微波辐射的传输路径受海拔高度的影响,地表发射特性受地形坡度和坡向的影响,山体间的多次反射和地形的阴影效应也会改变地表的散射特性.目前,数项微波辐射地形效应的模拟研究已在国内外开展,并据此提出了一些简化的地形校正方法.为了使人们对该领域研究有一概括了解,基于电磁波辐射传输的物理机理和地表形态特征的统计分析,首先探讨了地形效应对微波辐射传输和地表微波辐射特征以及土壤水分反演算法的影响,然后通过地形在微波辐射研究中的最新进展综述,提出了目前研究中存在的问题以及进一步的研究方向.%As SMOS (Soil Moisture and Ocean Salinity) mission has been carried out smoothly, and AMSR - E ( Advanced Microwave Scanning Radiometer - Earth Observing System) services have been conducted, people have achieved another great leap forward in monitoring surface soil moisture by satellite - borne microwave radiometer in space technology. Since space resolution is coarse under satellite microwave radiometer, the accuracy of retrieving soil moisture has been conditioned by space heterogeneity and relief effects. Mountainous terrain on a larger scale than wavelength has such significant effects on passive remote sensing as altitude role in microwave transmission path, topographic slope angle and aspect effects on surface emissivity, and multi - reflection between mountains or shadow effect on the change in surface scatter characteristics. A

  20. 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

  1. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Agudo Jacome, L., E-mail: leonardo.agudo@bam.de [Institut fuer Werkstoffe, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Eggeler, G., E-mail: gunther.eggeler@ruhr-uni-bochum.de [Institut fuer Werkstoffe, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Dlouhy, A., E-mail: dlouhy@ipm.cz [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno (Czech Republic)

    2012-11-15

    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: Black-Right-Pointing-Pointer The advanced STEM/HAADF diffraction contrast is extended to 3D stereo-imaging. Black-Right-Pointing-Pointer The advantages of the new technique over stereo-imaging in CTEM are demonstrated. Black-Right-Pointing-Pointer The new method allows foil thickness measurements in a broad range of conditions. Black-Right-Pointing-Pointer We show that features associated with ion milling surface damage can be beneficial for appreciating 3D features of the microstructure.

  3. 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

  4. 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.

  5. Full microwave synthesis of advanced Li-rich manganese based cathode material for lithium ion batteries

    Science.gov (United States)

    Shi, Shaojun; Zhang, Saisai; Wu, Zhijun; Wang, Ting; Zong, Jianbo; Zhao, Mengxi; Yang, Gang

    2017-01-01

    In technologically important Li-rich layered cathode materials, the synthesis time is a critical determinant to overcome the practical difficulties. Normal technology costs at least one day or even more to obtain final Li-rich cathode material. Full microwave synthesis is performed here to obtain final Li1.2Mn0.56Ni0.16Co0.08O2 within 60 min with high time-efficiency and power economization. The as-prepared Li-rich oxides keep the spherical hierarchical structure of the precursor. Compared to the same material obtained by traditional calcination, it exhibits well-formed layered structure with higher ordered ion arrangement. X-ray photoelectron spectroscopy (XPS) indicates that microwave assisted heating contributes to a more ordered and stable surface with desired Mn, Co, Ni element states and less impurity. Thus, the as-prepared material reveals remarkable electrochemical property with high discharge capacity of 159.3 mAh g-1 at high current density of 2000 mA g-1. And 88.6% specific capacity is remained after 300 cycles at such high current density. Furthermore, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) are carried out to overall investigate and estimate the material. It is concluded that such full microwave synthesis is really promising as one of the dominant way to obtain Li-rich layered cathode material for applications.

  6. Cloud clearing techniques over land for land surface temperature retrieval from the Advanced Along Track Scanning Radiometer

    OpenAIRE

    Bulgin, C.E.; H. Sembhi; D. Ghent; Remedios, J.J.; Merchant, Christopher

    2014-01-01

    We present five new cloud detection algorithms over land based on dynamic threshold or Bayesian techniques, applicable to the Advanced Along Track Scanning Radiometer (AATSR) instrument and compare these with the standard threshold based SADIST cloud detection scheme. We use a manually classified dataset as a reference to assess algorithm performance and quantify the impact of each cloud detection scheme on land surface temperature (LST) retrieval. The use of probabilistic Bayesian cloud dete...

  7. 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

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

    Science.gov (United States)

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

    2015-03-01

    The routine "on demand" fabrication of features smaller than 10 nm opens up new possibilities for the realization of many novel nanoelectronic, NEMS, optical and bio-nanotechnology-based devices. Based on the thermally actuated, piezoresistive cantilever technology we have developed a first prototype of a scanning probe lithography (SPL) platform able to image, inspect, align and pattern features down to single digit nano regime. The direct, mask-less patterning of molecular resists using active scanning probes represents a promising path circumventing the problems in today's radiation-based lithography. Here, we present examples of practical applications of the previously published electric field based, current-controlled scanning probe lithography on molecular glass resist calixarene by using the developed tabletop SPL system. We demonstrate the application of a step-and-repeat scanning probe lithography scheme including optical as well as AFM based alignment and navigation. In addition, sequential read-write cycle patterning combining positive and negative tone lithography is shown. We are presenting patterning over larger areas (80 x 80 μm) and feature the practical applicability of the lithographic processes.

  9. Remote monitoring of soil moisture using passive microwave-based technologies – theoretical basic and overview of selected algorithms for AMSR-E

    Science.gov (United States)

    Satellite-based passive microwave remote sensing has been shown to be a valuable tool in mapping and monitoring global soil moisture. The Advanced Microwave Scanning Radiometer on the Aqua platform (AMSR-E) has made significant contributions to this application. As the result of agency and individua...

  10. 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.

  11. Measurement of high frequency conductivity of oxide-doped anti-ferromagnetic thin film with a near-field scanning microwave microscope

    Directory of Open Access Journals (Sweden)

    Z. Wu

    2014-04-01

    Full Text Available In this manuscript, we describe how the map of high frequency conductivity distribution of an oxide-doped anti-ferromagnetic 200 nm thin film can be obtained from the quality factor (Q measured by a near-field scanning microwave microscope (NSMM. Finite element analysis (FEA is employed to simulate the NSMM tip-sample interaction and obtain a curve related between the simulated quality factor (Q and conductivity. The curve is calibrated by a standard Cu thin film with thickness of 200 nm, together with NSMM measured Q of Ag, Au, Fe, Cr and Ti thin films. The experimental conductivity obtained by the NSMM for IrMn thin films with various doped concentrations of Al2O3 is found consistent with conventional voltammetry measurement in the same tendency. That conductivity decreases as the content of doped Al2O3 increases. The results and images obtained demonstrate that NSMM can be employed in thin film analysis for characterization of local electrical properties of materials in a non-destructive manner and for obtaining a map of conductivity distribution on the same film.

  12. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Zhigang, E-mail: weizhigang321321@163.com; Ye, Xin, E-mail: yexintaian@aliyun.com; Yang, Xia, E-mail: yangxjinan@163.com; Zheng, Aimin, E-mail: am-zheng@163.com; Huang, Guanghui, E-mail: hgh3612@163.com; Li, Wenhong, E-mail: wenghong-li@163.com; Ni, Xiang, E-mail: asuka2521@hotmail.com; Wang, Jiao; Han, Xiaoying, E-mail: mylittlecarol@sina.com [Shandong Provincial Hospital Affiliated to Shandong University, Department of Oncology (China)

    2015-02-15

    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.

  14. 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 .

  15. Modification of the Sandia National Laboratories/California advanced coordinate measuring machine for high speed scanning

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, J.M.; Pilkey, R.D. [Sandia National Labs., Livermore, CA (United States); Cassou, R.M.; Summerhays, K.D. [Univ. of San Francisco, CA (United States)] [and others

    1997-03-01

    The Moore M48V high accuracy coordinate measuring machine (CMM), while mechanically capable of exact measurement of physical artifacts, is not, in its original configuration, well suited for rapid gathering of high density dimensional information. This report describes hardware and software modifications to the original control and data acquisition system that allow relatively high speed scanning of cylindrical features. We also estimate the accuracy of the individual point data on artifacts measured with this system and provide detailed descriptions of the hardware and software apparatus as an aid to others who may wish to apply the system to cylindrical or other simple geometries. 6 refs., 18 figs., 1 tab.

  16. 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

  17. Conductive heating and microwave hydrolysis under identical heating profiles for advanced anaerobic digestion of municipal sludge.

    Science.gov (United States)

    Mehdizadeh, Seyedeh Neda; Eskicioglu, Cigdem; Bobowski, Jake; Johnson, Thomas

    2013-09-15

    Microwave (2.45 GHz, 1200 W) and conventional heating (custom pressure vessel) pretreatments were applied to dewatered municipal waste sludge (18% total solids) using identical heating profiles that span a wide range of temperatures (80-160 °C). Fourteen lab-scale semi-continuous digesters were set up to optimize the energy (methane) output and sludge retention time (SRT) requirements of untreated (control) and thermally pretreated anaerobic digesters operated under mesophilic and thermophilic temperatures. Both pretreatment methods indicated that in the pretreatment range of 80-160 °C, temperature was a statistically significant factor (p-value heating, had no statistically significant effect (p-value >0.05) on sludge solubilization. With the exception of the control digesters at a 5-d SRT, all control and pretreated digesters achieved steady state at all three SRTs, corresponding to volumetric organic loading rates of 1.74-6.96 g chemical oxygen demand/L/d. At an SRT of 5 d, both mesophilic and thermophilic controls stopped producing biogas after 20 d of operation with total volatile fatty acids concentrations exceeding 1818 mg/L at pH <5.64 for mesophilic and 2853 mg/L at pH <7.02 for thermophilic controls, while the pretreated digesters continued producing biogas. Furthermore, relative (to control) organic removal efficiencies dramatically increased as SRT was shortened from 20 to 10 and then 5 d, indicating that the control digesters were challenged as the organic loading rate was increased. Energy analysis showed that, at an elevated temperature of 160 °C, the amount of methane recovered was not enough to compensate for the energy input. Among the digesters with positive net energy productions, control and pretreated digesters at 80 °C were more favorable at an SRT of 10 d.

  18. Electrical characterization of dislocations in gallium nitride using advanced scanning probe techniques

    Science.gov (United States)

    Simpkins, Blake Shelley Ginsberg

    GaN-based materials are promising for high speed and power applications such as amplifier and communications circuits. Ga, In, and AIN-based alloys span a wide optical range (2--6.1 eV) and exhibit strong polarizations making them useful in many devices; however, films are highly defective (˜10 8 dislocations cm-2) due to lack of suitable substrates. Thus, nanoscale electronic characterization of these dislocations is critical for device and growth optimization. Scanning probe techniques enable characterization at length-scales unattainable by conventional techniques. First, scanning Kelvin probe microscopy (SKPM) was used to image surface potential variations due to charged dislocations in HVPE-grown GaN. The film's structural evolution "with thickness was monitored showing a decrease in dislocation density, likely through dislocation reaction. Numerical simulations were used to investigate tip-size effects when imaging highly localized (tens of nm) potential variations indicating that measured dislocation induced potential features in GaN can be much smaller (˜80%) than true variations. Next, capacitance variations in MBE-grown HFETs, due to dislocations-induced carrier depletion, were imaged with scanning capacitance microscopy (SCM). The distribution of these charged centers was correlated with buffer schemes showing that an AIN buffer leads to pseudomorphic (2D) nucleation and randomly distributed misfit dislocations while deposition directly on SiC results in island (3D) nucleation and a domain structure with dislocations grouped at domain boundaries. Hall measurements and numerical simulations were also carried out to further study the implications of these microstructures. Numerical results indicated that randomly distributed dislocations deplete a larger fraction of free carriers than the same density of grouped dislocations and correlated favorably with Hall results. Correlated SKPM and conductive AFM (C-AFM) measurements were then used to study

  19. 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...

  20. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). As-Designed Parts List: Electrical, Electronic, and Electromechanical (EEE) As-Built Parts List for the AMSU-A Instruments

    Science.gov (United States)

    2000-01-01

    This is the As-Designed Parts List, Electrical, Electronic, and Electromechanical (EEE) As-Built Parts Lists For The AMSU-A Instruments, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

  1. Development of tomographic reconstruction methods in materials science with focus on advanced scanning methods

    DEFF Research Database (Denmark)

    Lyckegaard, Allan

    Techniques for obtaining 3 dimensional information of individual crystals, socalled grains, in polycrystalline materials are important within the field of materials science for understanding and modeling the behavior of materials.In the last decade, a number of nondestructive X-ray diffraction...... techniques. Combining this with a novel 6-dimensional indexing routine it is possible to determine grain centers, radii and orientations of hundreds of individual grains in a sample. The grain centers are found with a precision which is better than the stepping size, and thus provides a road towards future......-stable beta titanium alloy comprising 1265 grains has been produced as part of a collaboration on spatial resolved strain measurements with Cornell University, USA, and the Advanced Photon Source, USA....

  2. Polarized light-scattering profile-advanced characterization of nonspherical particles with scanning flow cytometry.

    Science.gov (United States)

    Strokotov, Dmitry I; Moskalensky, Alexander E; Nekrasov, Vyacheslav M; Maltsev, Valeri P

    2011-07-01

    We instrumentally, theoretically, and experimentally demonstrate a new approach for characterization of nonspherical individual particles from light scattering. Unlike the original optical scheme of the scanning flow cytometer that measures an angle-resolved scattering corresponding in general to S₁₁ element of the light-scattering matrix, the modernized instrument allows us to measure the polarized light-scattering profile of individual particles simultaneously. Theoretically, the polarized profile is expressed by the combination of a few light-scattering matrix elements. This approach supports us with additional independent data to characterize a particle with a complex shape and an internal structure. Applicability of the new method was demonstrated from analysis of polymer bispheres. The bisphere characteristics, sizes, and refractive indices of each sphere composing the bisphere were successfully retrieved from the solution of the inverse light-scattering problem. The solution provides determination of the Eulerian angles, which describe the orientation of the bispheres relative to the direction of the incident laser beam and detecting polarizer of the optical system. Both the ordinary and polarized profiles show a perfect agreement with T-matrix simulation resulting to 50-nm precision for sizing of bispheres.

  3. 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.

  4. Proton irradiation effects on advanced digital and microwave III-V components

    Energy Technology Data Exchange (ETDEWEB)

    Hash, G.L.; Schwank, J.R.; Shaneyfelt, M.R.; Sandoval, C.E.; Connors, M.P.; Sheridan, T.J.; Sexton, F.W.; Slayton, E.M.; Heise, J.A. [Sandia National Labs., Albuquerque, NM (United States); Foster, C. [Indiana University Cyclotron Facility, Bloomington, IN (United States)

    1994-09-01

    A wide range of advanced III-V components suitable for use in high-speed satellite communication systems were evaluated for displacement damage and single-event effects in high-energy, high-fluence proton environments. Transistors and integrated circuits (both digital and MMIC) were irradiated with protons at energies from 41 to 197 MeV and at fluences from 10{sup 10} to 2 {times} 10{sup 14} protons/cm{sup 2}. Large soft-error rates were measured for digital GaAs MESFET (3 {times} 10{sup {minus}5} errors/bit-day) and heterojunction bipolar circuits (10{sup {minus}5} errors/bit-day). No transient signals were detected from MMIC circuits. The largest degradation in transistor response caused by displacement damage was observed for 1.0-{mu}m depletion- and enhancement-mode MESFET transistors. Shorter gate length MESFET transistors and HEMT transistors exhibited less displacement-induced damage. These results show that memory-intensive GaAs digital circuits may result in significant system degradation due to single-event upset in natural and man-made space environments. However, displacement damage effects should not be a limiting factor for fluence levels up to 10{sup 14} protons/cm{sup 2} [equivalent to total doses in excess of 10 Mrad(GaAs)].

  5. 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.

  6. Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL)

    Science.gov (United States)

    1996-01-01

    This Failure Modes and Effects Analysis (FMEA) is for the Advanced Microwave Sounding Unit-A (AMSU-A) instruments that are being designed and manufactured for the Meteorological Satellites Project (METSAT) and the Earth Observing System (EOS) integrated programs. The FMEA analyzes the design of the METSAT and EOS instruments as they currently exist. This FMEA is intended to identify METSAT and EOS failure modes and their effect on spacecraft-instrument and instrument-component interfaces. The prime objective of this FMEA is to identify potential catastrophic and critical failures so that susceptibility to the failures and their effects can be eliminated from the METSAT/EOS instruments.

  7. Advances in protective agents against high power microwave radiation damage%高功率微波辐射损伤防护药物研究进展

    Institute of Scientific and Technical Information of China (English)

    郑文; 王长振; 胡向军

    2014-01-01

    Along with the development of science and technology , microwaves are widely used in various fields .Though they have brought much convenience to people , their potential adverse health effects are becoming a concern of governments and researchers .High power microwaves ( HPMs) are widely used in high-tech and new concept weapons , increasing the chance that troops are exposed to HPM environments .It has been clearly confirmed that microwave radiation could cause varying degrees of damage to the nervous system , immune system , cardiovascular system and reproductive system under specific conditions .Therefore , it is of important significance to reduce adverse effects of HPM radiation and improve the combat capability of troops via effective medical protection while doing well in physical protection .According to the mecha-nism and characteristics of microwave radiation damage effects , recent advances in microwave radiation protection are re-viewed in this article , hoping to facilitate research on safer and better drugs .%随着科技的进步,微波被广泛运用到各个领域,给人类带来便利的同时,其潜在的健康损害普遍受到各国政府和科研人员的关注。高功率微波( high power microwave ,HPM)在高新技术武器和新概念武器中的应用,使得部队官兵暴露于HPM环境下的概率增加。已有研究明确证实,特定条件的微波辐射对神经系统、免疫系统、心血管系统以及生殖系统存在不同程度的损伤效应。因此,在做好物理防护的同时,积极有效的医学防护,对于减小HPM损伤效应、提高部队官兵作战能力具有重要的意义。该文针对微波辐射损伤效应的机制特点,对近年来微波辐射损伤防护药物的研究进展进行综述,为更加安全有效的新药研发提供依据。

  8. Effect of H2O2 dosing strategy on sludge pretreatment by microwave-H2O2 advanced oxidation process.

    Science.gov (United States)

    Wang, Yawei; Wei, Yuansong; Liu, Junxin

    2009-09-30

    Considering characteristics of breaking down H(2)O(2) into water and molecular oxygen by catalase in waste activated sludge (WAS), the effect of H(2)O(2) dosing strategy on sludge pretreatment by the advanced oxidation process (AOP) of microwave-H(2)O(2) was investigated by batch experiments for optimizing H(2)O(2) dosage. Results showed that the catalase in sludge was active at the low temperature range between 15 degrees C and 45 degrees C, and gradually lost activity from 60 degrees C to 80 degrees C. Therefore, the H(2)O(2) was dosed at 80 degrees C, to which the waste activated sludge was first heated by the microwave (MW), and then the sludge dosed with H(2)O(2) was continuously heated till 100 degrees C by the microwave. Results at different H(2)O(2) dosages showed that the higher the H(2)O(2) dosing ratio was, the more the SCOD and total organic carbon (TOC) were released into the supernatant, and the optimum range of H(2)O(2)/TCOD ratio should be between 0.1 and 1.0. The percentages of consumed H(2)O(2) in the AOP of microwave and H(2)O(2) treating the WAS were 25.38%, 22.53%, 14.82%, 13.61% and 19.63% at different H(2)O(2)/TCOD dosing ratios of 0.1, 0.5, 1, 2, 4, respectively. Along with the increasing H(2)O(2)/TCOD ratio, the contents of TCOD on particles, soluble substances and mineralization increased and the TCOD distribution on solids decreased.

  9. 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

  10. 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.

  11. 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.

  12. Integrated microwave photonics

    CERN Document Server

    Marpaung, David; 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 reduction of size, weight, cost and power consumption. This article reviews the recent advances in this emerging field which is dubbed as integrated microwave photonics. Key integrated MWP technologies are reviewed and the prospective of the field is discussed.

  13. Microwave Ovens

    Science.gov (United States)

    ... ovens heat food using microwaves, a form of electromagnetic radiation similar to radio waves. Microwaves have three characteristics ... that their microwave oven products meet the strict radiation safety standard ... if your microwave oven has damage to its door hinges, latches, or seals, or ...

  14. Protectants against microwave irradiation: research advances%微波辐射防护药物的研究进展

    Institute of Scientific and Technical Information of China (English)

    王亚男; 周喆; 王升启

    2013-01-01

    微波辐射可致机体发生氧化应激,使氧化产物增多和抗氧化酶活性降低,甚至引起机体组织病理学改变.药物防护可以减轻微波辐射导致的氧化应激损伤,并对微波辐射所致组织病理学改变有所改善.近年来研究的抗微波辐射药物主要有卡尼汀、褪黑激素、咖啡酸苯乙酯、绿茶及其提取物、银杏叶提取物、阿的平,以及中成药芩丹扶正胶囊和安多霖等.本文综述了微波辐射对机体的氧化损伤机制,以及微波辐射防护药物的研究现状.%Microwave radiation can lead to oxidative stress, which may increase oxidation products, reduce activity of antioxi-dant enzymes and even cause pathological changes. Protectants against microwave irradiation can reverse these injuries and alleviate the pathological changes, which include carnitine, melatonin, caffeic acid phenethyl ester, green tea and its extract, Ginkgo biloba extract, quinacrine, and traditional Chinese formulae such as Qindanfuzheng and Anduolin, etc. In this paper, the mechanism of oxidative injury induced by microwave radiation and research progress in protectants are reviewed.

  15. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). As-Designed Parts List: Electrical, Electronic and Electromechanical (EEE) As-Designed Parts List

    Science.gov (United States)

    Lorenz, E.

    1999-01-01

    This report comprises the Electrical, Electronic, and Electromechanical (EEE) As Designed Parts List to be used in the Integrated Advanced Microwave Sounding Unit-A (AMSU-A) instrument. The purpose of the EEE As-Designed Parts List is to provide a listing of EEE parts identified for use on the Integrated AMSU-A. All EEE parts used on the AMSU-A must meet the parts control requirements as defined in the Parts Control Plan (POP). All part applications are reviewed by the Parts Control Board (PCB) and granted approval if POP requirements are met. The "As Designed Parts Lists" indicates PCB approval status, and thus also serves as the Program Approved Parts List.

  16. 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

  17. 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.

  18. 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

  19. Post-processing to remove residual clouds from aerosol optical depth retrieved using the Advanced Along Track Scanning Radiometer

    Science.gov (United States)

    Sogacheva, Larisa; Kolmonen, Pekka; Virtanen, Timo H.; Rodriguez, Edith; Saponaro, Giulia; de Leeuw, Gerrit

    2017-02-01

    Cloud misclassification is a serious problem in the retrieval of aerosol optical depth (AOD), which might considerably bias the AOD results. On the one hand, residual cloud contamination leads to AOD overestimation, whereas the removal of high-AOD pixels (due to their misclassification as clouds) leads to underestimation. To remove cloud-contaminated areas in AOD retrieved from reflectances measured with the (Advanced) Along Track Scanning Radiometers (ATSR-2 and AATSR), using the ATSR dual-view algorithm (ADV) over land or the ATSR single-view algorithm (ASV) over ocean, a cloud post-processing (CPP) scheme has been developed at the Finnish Meteorological Institute (FMI) as described in Kolmonen et al. (2016). The application of this scheme results in the removal of cloud-contaminated areas, providing spatially smoother AOD maps and favourable comparison with AOD obtained from the ground-based reference measurements from the AERONET sun photometer network. However, closer inspection shows that the CPP also removes areas with elevated AOD not due to cloud contamination, as shown in this paper. We present an improved CPP scheme which better discriminates between cloud-free and cloud-contaminated areas. The CPP thresholds have been further evaluated and adjusted according to the findings. The thresholds for the detection of high-AOD regions (> 60 % of the retrieved pixels should be high-AOD (> 0.6) pixels), and cloud contamination criteria for low-AOD regions have been accepted as the default for AOD global post-processing in the improved CPP. Retaining elevated AOD while effectively removing cloud-contaminated pixels affects the resulting global and regional mean AOD values as well as coverage. Effects of the CPP scheme on both spatial and temporal variation for the period 2002-2012 are discussed. With the improved CPP, the AOD coverage increases by 10-15 % with respect to the existing scheme. The validation versus AERONET shows an improvement of the correlation

  20. 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

    The role of positron emission tomography-computed tomography (PET-CT) in surveillance of patients with nonsmall cell lung cancer (NSCLC) treated with curatively intended chemoradiotherapy remains controversial. However, conventional chest X-ray and computed tomography (CT) are of limited value...... in 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...

  1. A versatile dual spot laser scanning confocal microscopy system for advanced fluorescence correlation spectroscopy analysis in living cell

    CERN Document Server

    Ferrand, P; Kress, A; Aillaud, A; Rigneault, H; Marguet, D

    2009-01-01

    A fluorescence correlation spectroscopy (FCS) system based on two independent measurement volumes is presented. The optical setup and data acquisition hardware are detailed, as well as a complete protocol to control the location, size and shape of the measurement volumes. A method that allows to monitor independently the excitation and collection efficiency distribution is proposed. Finally, a few examples of measurements that exploit the two spots in static and/or scanning schemes, are reported.

  2. 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".

  3. Validation of brightness and physical temperature from two scanning microwave radiometers in the 60 GHz O2 band using radiosonde measurements

    Science.gov (United States)

    Navas-Guzmán, Francisco; Kämpfer, Niklaus; Haefele, Alexander

    2016-09-01

    In this paper, we address the assessment of the tropospheric performance of a new temperature radiometer (TEMPERA) at 60 GHz. With this goal, an intercomparison campaign was carried out at the aerological station of MeteoSwiss in Payerne (Switzerland). The brightness temperature and the tropospheric temperature were assessed by means of a comparison with simultaneous and collocated radiosondes that are launched twice a day at this station. In addition, the TEMPERA performances are compared with the ones from a commercial microwave radiometer (HATPRO), which has some different instrumental characteristics and uses a different inversion algorithm. Brightness temperatures from both radiometers were compared with the ones simulated using a radiative transfer model and atmospheric profiles from radiosondes. A total of 532 cases were analyzed under all weather conditions and evidenced larger brightness temperature deviations between the two radiometers and the radiosondes for the most transparent channels. Two different retrievals for the TEMPERA radiometer were implemented in order to evaluate the effect of the different channels on the temperature retrievals. The comparison with radiosondes evidenced better results very similar to the ones from HATPRO, when the eight more opaque channels were used. The study shows the good performance of TEMPERA to retrieve temperature profiles in the troposphere. The inversion method of TEMPERA is based on the optimal estimation method. The main advantage of this algorithm is that there is no necessity for radiosonde information to achieve good results in contrast to conventional methods as neural networks or lineal regression. Finally, an assessment of the effect of instrumental characteristics as the filter response and the antenna pattern on the brightness temperature showed that they can have an important impact on the most transparent channels.

  4. Microwave Photonics

    OpenAIRE

    Seeds, A.J.; Liu, C. P.; T. Ismail; 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.

  5. Bisphosphonate-related osteonecrosis of jaws in advanced stage breast cancer was detected from bone scan: a case report

    Science.gov (United States)

    Chirappapha, Prakasit; Thongjood, Thanaporn; Aroonroch, Rangsima

    2017-01-01

    Bisphosphonates (BPs) are indicated to treat skeletal-related events (SREs) for cancer patients with bone metastasis. We report a 79-year-old woman with advanced stage breast cancer with bone metastasis who was prescribed BPs (zoledronate), then developed osteonecrosis of jaw. We provide a brief review of the pathogenesis, diagnosis and treatment of this complication. PMID:28210558

  6. Advanced methods for cosmic microwave background data analysis the big N^3 and how to beat it

    CERN Document Server

    Wandelt, B D

    2000-01-01

    In this talk we propose the first fast methods which can analyze CMB data taking into account correlated noise, arbitrary beam shapes, non-uniform distribution of integration time on the sky, and partial sky coverage, without the need for approximations. These ring torus methods work by performing the analysis in the time ordered domain (TOD) rather than on the sky map of fluctuations. They take advantage of the simplicity of noise correlations in the TOD as well as certain properties of the group of rotations SO(3). These properties single out a family of scanning strategies as favourable, namely those which scan on rings and have the geometry of an n-torus. This family includes the strategies due to TOPHAT, MAP and Planck. We first develop the tools to model the time ordered signal, using our Fast Fourier Transform methods for convolution of two arbitrary functions on the sphere (Wandelt and G\\'orski 2000). Then we apply these ideas to show that in the case of a 2-torus we can reduce the time taken for CMB ...

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. Radionucleotide scanning in osteomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, W.; Kanat, I.O.

    1986-07-01

    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.

  13. Global Snow Mass Measurements and the Effect of Stratigraphic Detail on Inversion of Microwave Brightness Temperatures

    Science.gov (United States)

    Richardson, Mark; Davenport, Ian; Gurney, Robert

    2014-05-01

    Snow provides large seasonal storage of freshwater, and information about the distribution of snow mass as snow water equivalent (SWE) is important for hydrological planning and detecting climate change impacts. Large regional disagreements remain between estimates from reanalyses, remote sensing and modelling. Assimilating passive microwave information improves SWE estimates in many regions, but the assimilation must account for how microwave scattering depends on snow stratigraphy. Physical snow models can estimate snow stratigraphy, but users must consider the computational expense of model complexity versus acceptable errors. Using data from the National Aeronautics and Space Administration Cold Land Processes Experiment and the Helsinki University of Technology microwave emission model of layered snowpacks, it is shown that simulations of the brightness temperature difference between 19 and 37 GHz vertically polarised microwaves are consistent with advanced microwave scanning radiometer-earth observing system and special sensor microwave imager retrievals once known stratigraphic information is used. Simulated brightness temperature differences for an individual snow profile depend on the provided stratigraphic detail. Relative to a profile defined at the 10-cm resolution of density and temperature measurements, the error introduced by simplification to a single layer of average properties increases approximately linearly with snow mass. If this brightness temperature error is converted into SWE using a traditional retrieval method, then it is equivalent to ±13 mm SWE (7 % of total) at a depth of 100 cm. This error is reduced to ±5.6 mm SWE (3 % of total) for a two-layer model.

  14. Microwave Ferrites for Cryogenic Applications

    OpenAIRE

    G. Dionne

    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 ...

  15. 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.

  16. 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.

  17. 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.

  18. 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 ...

  19. 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

  20. 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.

  1. 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.

  2. Microwave Multicomponent Synthesis

    Directory of Open Access Journals (Sweden)

    Helmut M. Hügel

    2009-12-01

    Full Text Available 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 achieved over the last five years.

  3. 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

  4. Microwave generator

    Science.gov (United States)

    Kwan, T.J.T.; Snell, C.M.

    1987-03-31

    A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit there through effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators. 6 figs.

  5. Satellite detection of IR precursors using bi-angular advanced along-track scanning radiometer data: a case study of Yushu earthquake

    Institute of Scientific and Technical Information of China (English)

    Pan Xiong; Xuhui Shen; Xingfa Gu; Qingyan Meng; Yaxin Bi; Liming Zhao; Yanhua Zhao

    2015-01-01

    The paper has developed and proposed a synthesis analysis method based on the robust satellite data analysis technique (RST) to detect seismic anomalies within the bi-angular advanced along-track scanning radiometer (AATSR) gridded brightness temperature (BT)data based on spatial/temporal continuity analysis.The proposed methods have been applied to analyze the Yushu (Qinghai,China) earthquake occurred on 14th April 2010,and a full AATSR data-set of 8 years data from March 2003 to May 2010 with longitude from 91°E to 101°E and latitude from 28°N to 38°N has been analyzed.Combining with the tectonic explanation of spatial and temporal continuity of the abnormal phenomena,the analyzed results indicate that the infrared radiation anomalies detected by the AATSR BT data with nadir view appear and enhance gradually along with the development and occurring of the earthquake,especially along the Ganzi-Yushu fault,Nu River fault and Jiali-Chayu fault;more infrared anomalies along the earthquake fault zone (Lancangjiang fault and Ning Karma Monastery-Deqin fault) are detected using the proposed synthesis analysis method,which can also characterize the activity of seismic faults more precisely.

  6. Advanced Microwave Circuits and Systems

    DEFF Research Database (Denmark)

    such as voltage-controlled oscillators and electron devices for millimeter wave and submillimeter wave applications. This part also covers studies of integrated buffer circuits. Passive components are indispensable elements of any electronic system. The increasing demands to miniaturization and cost effectiveness...... 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......, bandwidth, and power consumption, which generally accompanies the LNA design process, is discussed in this part. The requirement from an amplifier design differs for different applications. A power amplifier is a type of amplifier which drives the antenna of a transmitter. Unlike LNA, a power amplifier...

  7. The new Passive microwave Neural network Precipitation Retrieval (PNPR) algorithm for the cross-track scanning ATMS radiometer: description and verification study over Europe and Africa using GPM and TRMM spaceborne radars

    Science.gov (United States)

    Sanò, Paolo; Panegrossi, Giulia; Casella, Daniele; Marra, Anna C.; Di Paola, Francesco; Dietrich, Stefano

    2016-11-01

    The objective of this paper is to describe the development and evaluate the performance of a completely new version of the Passive microwave Neural network Precipitation Retrieval (PNPR v2), an algorithm based on a neural network approach, designed to retrieve the instantaneous surface precipitation rate using the cross-track Advanced Technology Microwave Sounder (ATMS) radiometer measurements. This algorithm, developed within the EUMETSAT H-SAF program, represents an evolution of the previous version (PNPR v1), developed for AMSU/MHS radiometers (and used and distributed operationally within H-SAF), with improvements aimed at exploiting the new precipitation-sensing capabilities of ATMS with respect to AMSU/MHS. In the design of the neural network the new ATMS channels compared to AMSU/MHS, and their combinations, including the brightness temperature differences in the water vapor absorption band, around 183 GHz, are considered. The algorithm is based on a single neural network, for all types of surface background, trained using a large database based on 94 cloud-resolving model simulations over the European and the African areas. The performance of PNPR v2 has been evaluated through an intercomparison of the instantaneous precipitation estimates with co-located estimates from the TRMM Precipitation Radar (TRMM-PR) and from the GPM Core Observatory Ku-band Precipitation Radar (GPM-KuPR). In the comparison with TRMM-PR, over the African area the statistical analysis was carried out for a 2-year (2013-2014) dataset of coincident observations over a regular grid at 0.5° × 0.5° resolution. The results have shown a good agreement between PNPR v2 and TRMM-PR for the different surface types. The correlation coefficient (CC) was equal to 0.69 over ocean and 0.71 over vegetated land (lower values were obtained over arid land and coast), and the root mean squared error (RMSE) was equal to 1.30 mm h-1 over ocean and 1.11 mm h-1 over vegetated land. The results showed a

  8. EDITORIAL: Microwave Moisture Measurements

    Science.gov (United States)

    Kaatze, Udo; Kupfer, Klaus; Hübner, Christof

    2007-04-01

    Microwave moisture measurements refer to a methodology by which the water content of materials is non-invasively determined using electromagnetic fields of radio and microwave frequencies. Being the omnipresent liquid on our planet, water occurs as a component in most materials and often exercises a significant influence on their properties. Precise measurements of the water content are thus extremely useful in pure sciences, particularly in biochemistry and biophysics. They are likewise important in many agricultural, technical and industrial fields. Applications are broad and diverse, and include the quality assessment of foodstuffs, the determination of water content in paper, cardboard and textile production, the monitoring of moisture in sands, gravels, soils and constructions, as well as the measurement of water admixtures to coal and crude oil in reservoirs and in pipelines. Microwave moisture measurements and evaluations require insights in various disciplines, such as materials science, dielectrics, the physical chemistry of water, electrodynamics and microwave techniques. The cooperation of experts from the different fields of science is thus necessary for the efficient development of this complex discipline. In order to advance cooperation the Workshop on Electromagnetic Wave Interaction with Water and Moist Substances was held in 1993 in Atlanta. It initiated a series of international conferences, of which the last one was held in 2005 in Weimar. The meeting brought together 130 scientists and engineers from all over the world. This special issue presents a collection of some selected papers that were given at the event. The papers cover most topics of the conference, featuring dielectric properties of aqueous materials, electromagnetic wave interactions, measurement methods and sensors, and various applications. The special issue is dedicated to Dr Andrzej W Kraszewski, who died in July 2006 after a distinguished career of 48 years in the research of

  9. 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...

  10. 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...

  11. 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.

  12. Application of microwave cake material%微波蛋糕的原料应用

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Along with the advancement of the microwave oven manufacturing technique and the constant descend of its price, microwave oven equipment is gradually becoming the familiar application in family, the manufacture and consumption of lots of food use the technique of microwave processing, so the research on microwave recuperating food is one of the hottest researching subjects.

  13. 微波对淀粉特性影响的研究进展%The advance of the microwave on starch character's effect

    Institute of Scientific and Technical Information of China (English)

    原沙沙; 谢岩黎; 王金水

    2011-01-01

    Microwave energy is the non-ionizing energy source because it creates heat deep within the materials being processed as a result of rapid changes of the electromagnetic field at high frequency.Microwave radiation changes the structure of starch because of%微波是一种能以高频的方式使介质在电磁场中加热的非电离能量。微波辐射使淀粉支链和直连淀粉发生了降解因而改变了淀粉的结构。综述了微波辐射对淀粉颗粒的形态结构、微观结构、流变学、回生抗性、凝胶特性等影响的研究进展。

  14. 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)

  15. Microwave processing of epoxy resins and synthesis of carbon nanotubes by microwave plasma chemical vapor deposition

    Science.gov (United States)

    Zong, Liming

    Microwave processing of advanced materials has been studied as an attractive alternative to conventional thermal processing. In this dissertation, work was preformed in four sections. The first section is a review on research status of microwave processing of polymer materials. The second section is investigation of the microwave curing kinetics of epoxy resins. The curing of diglycidyl ether of bisphenol A (DGEBA) and 3, 3'-diaminodiphenyl sulfone (DDS) system under microwave radiation at 145 °C was governed by an autocatalyzed reaction mechanism. A kinetic model was used to describe the curing progress. The third section is a study on dielectric properties of four reacting epoxy resins over a temperature range at 2.45 GHz. The epoxy resin was DGEBA. The four curing agents were DDS, Jeffamine D-230, m-phenylenediamine, and diethyltoluenediamine. The mixtures of DGEBA and the four curing agents were stoichiometric. The four reacting systems were heated under microwave irradiation to certain cure temperatures. Measurements of temperature and dielectric properties were made during free convective cooling of the samples. The cooled samples were analyzed with a Differential Scanning Calorimeter to determine the extents of cure. The Davidson-Cole model can be used to describe the dielectric data. A simplified Davidson-Cole expression was proposed to calculate the parameters in the Davidson-Cole model and describe the dielectric properties of the DGEBA/DDS system and part of the dielectric data of the other three systems. A single relaxation model was used with the Arrhenius expression for temperature dependence to model the results. The evolution of all parameters in the models during cure was related to the decreasing number of the epoxy and amine groups in the reactants and the increasing viscosity of the reacting systems. The last section is synthesis of carbon nanotubes (CNTs) on silicon substrate by microwave plasma chemical vapor deposition of a gas mixture of

  16. Integrated Advanced Microwave Sounding Unit-A (AMSU-A. Engineering Report: Electromagnetic Interface (EMI)/Electromagnetic Radiation (EMR) and Electromagnetic Compatibility (EMC), for the METSAT/METOP AMSU-A1

    Science.gov (United States)

    Valdez, A.

    1999-01-01

    This document contains the procedure and the test results of the Advanced Microwave Sounding Unit-A (AMSU-A) Electromagnetic Interference (EMI), Electromagnetic Susceptibility, and Electromagnetic Compatibility (EMC) qualification test for the Meteorological Satellite (METSAT) and the Meteorological Operation Platform (METOP) projects. The test was conducted in accordance with the approved EMI/EMC Test Plan/Procedure, Specification number AE-26151/5D. This document describes the EMI/EMC test performed by Aerojet and it is presented in the following manner: Section-1 contains introductory material and a brief summary of the test results. Section 2 contains more detailed descriptions of the test plan, test procedure, and test results for each type of EMI/EMC test conducted. Section 3 contains supplementary information that includes test data sheets, plots, and calculations collected during the qualification testing.

  17. 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

  18. Effect of Microwave Treatment on Physicochemical Properties of Maize Flour

    OpenAIRE

    2015-01-01

    © 2015, Springer Science+Business Media New York. Relatively little work has been reported about flour changes during microwave irradiation. For this reason, maize flours were treated by microwave radiation at 400 W for 0.5, 1, 2 and 4 min, and their microstructure and physicochemical characteristics (X-ray diffractometry, differential scanning calorimetry and pasting properties) were analysed. Micrographs showed that maize flour treated by microwave radiation displayed less compacted particl...

  19. 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 ...

  20. 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

  1. On the use of passive microwaves at 37 GHz in remote sensing of vegetation

    Science.gov (United States)

    Kerr, Y. H.; Njoku, E. G.

    1993-01-01

    Recently, a number of studies have investigated the use of the 37 GHz channels of the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) for vegetation monitoring and for studying synergisms between the SMMR and the NOAA Advanced Very High Resolution Radiometer (AVHRR). The approaches are promising but raise a number of issues concerning interpretation of the results, specifically on the relative effects of vegetation and other surface and atmospheric characteristics on the observed signal. This article analyzes the 37 GHz Microwave Polarization Difference Temperature (MPDT) in terms of its sensitivity to surface and atmospheric parameters. For this, a radiative transfer model is used which indicates some limitations of the MPDT index and suggests the importance of accounting for atmospheric effects in the data analysis. An alternative approach to the MPDT, including lower SMMR frequencies than 37 GHz, is discussed.

  2. 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.

  3. 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

  4. RF and microwave microelectronics packaging II

    CERN Document Server

    Sturdivant, Rick

    2017-01-01

    Reviews RF, microwave, and microelectronics assembly process, quality control, and failure analysis Bridges the gap between low cost commercial and hi-res RF/Microwave packaging technologies Engages in an in-depth discussion of challenges in packaging and assembly of advanced high-power amplifiers This book presents the latest developments in packaging for high-frequency electronics. It is a companion volume to “RF and Microwave Microelectronics Packaging” (2010) and covers the latest developments in thermal management, electrical/RF/thermal-mechanical designs and simulations, packaging and processing methods, and other RF and microwave packaging topics. Chapters provide detailed coverage of phased arrays, T/R modules, 3D transitions, high thermal conductivity materials, carbon nanotubes and graphene advanced materials, and chip size packaging for RF MEMS. It appeals to practicing engineers in the electronic packaging and high-frequency electronics domain, and to academic researchers interested in underst...

  5. 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

  6. 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.

  7. 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.

  8. 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...

  9. Microwave Radiometry and Radiometers for Ocean Applications

    DEFF Research Database (Denmark)

    Skou, Niels

    2008-01-01

    The microwave radiometer system measures, within its bandwidth, the naturally emitted radiation – the brightness temperature – of substances within its antenna’s field of view. Thus a radiometer is really a sensitive and calibrated microwave receiver. The radiometer can be a basic total power....../antenna size, and the problem: scanning antenna/space- craft stability. In many cases good compromises have been reached, as evident recalling the many successful missions throughout the recent 30 years. But in some cases the situation calls for special solutions, like the push-broom system or the synthetic...... aperture radiometer technique, both yielding imaging capability without scanning. Typical applications of microwave radiometry concerning oceans are: sea salinity, sea surface temperature, wind speed and direction, sea ice detection and classification. However, in an attempt to measure properties...

  10. The microwave effects on the properties of alumina at high frequencies of microwave sintering

    Science.gov (United States)

    Sudiana, I. Nyoman; Mitsudo, Seitaro; Sako, Katsuhide; Inagaki, Shunsuke; Ngkoimani, La Ode; Usman, Ida; Aripin, H.

    2016-03-01

    Microwave sintering of materials has attracted much research interest because of its significant advantages (e.g. reduced sintering temperatures and soaking times) over the conventional heating. Most researchers compared processes that occurred during the microwave and conventional heating at the same temperature and time. The enhancements found in the former method are indicated as a `non-thermal effect` which is usually used for explaining the phenomena in microwave processing. Numerous recent studies have been focused on the effect to elucidate the microwave interaction mechanism with materials. Moreover, recent progress on microwave sources such as gyrotrons has opened the possibility for processing materials by using a higher microwave frequency. Therefore, the technology is expected to exhibit a stronger non-thermal effect. This paper presents results from a series of experiments to study the non-thermal effect on microwave sintered alumina. Sintering by using a wide rage of microwave frequencies up to 300 GHz as well as a conventional furnace was carried out. The linear shrinkages of samples for each sintering method were measured. Pores and grains taken from scanning electron microstructure (SEM) images of cut surfaces were also examined. The results of a comparative study of the shrinkages and microstructure evolutions of the sintered samples under annealing in microwave heating systems and in an electric furnace were analyzed. A notably different behavior of the shrinkages and microstructures of alumina after being annealed was found. The results suggested that microwave radiations provided an additional force for mass transports. The results also indicated that the sintering process depended on microwave frequencies.

  11. 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; CAT scan - brain ... hold your breath for short periods. A complete scan usually take only 30 seconds to a few ...

  12. 微波辅助萃取应用研究进展%Application and Advances of Microwave-assisted Extraction

    Institute of Scientific and Technical Information of China (English)

    卢彦芳; 张福成; 安静; 康丽娟; 蒋晔

    2011-01-01

    近年来关于微波辅助萃取(MAE)与其他各种样品前处理技术的结合使用,以及与多种检测技术在线联用的研究越来越多,此外离子液体等新型绿色溶剂作为萃取剂在MAE中的应用也开始得到广泛关注.本文综述了近几年微波辅助萃取在环境、天然产物提取、食品和药物分析领域的应用情况,并对其将来的发展进行了展望.%Microwave-assisted extraction(MAE) has been widely used in different fields of analytical chemistry due to the characteristics of rapidness, high effectiveness, good selectivity and reduced organic solvents consumption. In recent years, the research on combination of MAE and many other sample pretreatment methods, as well as online coupling of MAE with a variety of detection techniques has been increasing dramatically. Moreover, other neotype green solvents employed in MAE, such as ionic liquids, have also been attracted extensive attention of the researchers. In this paper, the research during the last several years on the application of MAE in environment analysis, extraction of natural products, food analysis and medicine analysis, and the developmental trend of MAE in the future are reviewed.

  13. The Microwave Assisted Composite Manufacturing and Repair (MACMAR) Project

    Science.gov (United States)

    Falker, John; Terrier, Douglas; Clayton, Ronald G.; Worthy, Erica; Sosa, Edward

    2015-01-01

    The inherent microwave property of carbon nanotubes (CNTs) generates the thermal energy required to induce reversible polymerization of the matrix in these self-healing composites. Microwaves will be used to demonstrate advanced composite manufacturing and repair using self-healing composites.

  14. Microwave sensing of quality attributes of agricultural and food products

    Science.gov (United States)

    Microwave sensors for real-time characterization of agricultural and food products have become viable solutions with recent advances in the development of calibration methods and the availability of inexpensive microwave components. The examples shown here for grain, seed, and in-shell peanuts indic...

  15. Microwave combustion and sintering without isostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Ebadian, M.A.

    1998-01-01

    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.

  16. Effect of microwave power on kinetics and characteristics of microwave vacuum-dried longan (Dimocarpus longan Lour.) pulp.

    Science.gov (United States)

    Su, Dongxiao; Zhang, Mingwei; Wei, Zhencheng; Tang, Xiaojun; Zhang, Ruifen; Liu, Lei; Deng, Yuanyuan

    2015-03-01

    The drying kinetics of longan (Dimocarpus longan Lour.) pulp processed by microwave vacuum under different microwave levels (2.67, 5.33, 8.00, and 10.67 W/g) was investigated (pressure controlled at -85 ± 2 kPa) in the present study. It was found that the drying rate of longan pulp was dependent on the microwave power, and the rehydration rate increased from 1.96 to 2.17 with the increase of microwave power from 2.67 to 10.67 W/g. Among nine selected thin layer models, the microwave vacuum drying of longan pulp was well represented by five models, which were Page, Modified Henderson and Pabis, Wang and Singh, Logarithmic, and Midilli models. Furthermore, the results of statistical analysis indicated that the Midilli model could describe the best experimental data. In addition, scanning electron microscope observation showed that the microwave vacuum-dried longan pulp had a porous structure.

  17. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Test Report, Electromagnetic Interference (EMI)/Electromagnetic Radiation(EMR) and Electromagnetic Capability (EMC) for the EOS/AMSU-A1

    Science.gov (United States)

    Paliwoda, L.

    1998-01-01

    This document contains the procedure and the test results of the Advanced Microwave Sounding Unit-A (AMSU-A) Earth Observing System (EOS) Project, assembly part number 1356008-1, serial number 202, Electromagnetic Interference (EMI) and Electromagnetic Susceptibility (EMC) qualification test. The test was conducted in accordance with the approved EMI/EMC Test Plan/Procedure, Specification number AE-26151/8B, dated 10 September 1998. Aerojet intends that the presentation and submittal of this document, prepared in accordance with the objectives established by the aforementioned Test Plan/Procedure, document number AE-26151/8B, will satisfy the data requirement with respect to the AMSU-A/EOS instrument operational compliance of the EMI/EMC test requirement. Test for the AMSU-A/EOS instrument have been completed and all the requirements per General Interface Requirement Document (GIRD), GSFC 422-11-12-01, for EOS Common Spacecraft/Instruments, paragraph 10.11, were met with the exceptions of the test methods CE03, RE01, and RE02, as described in this document.

  18. 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 v...

  19. 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...

  20. 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...

  1. 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 ...

  2. Effect of advanced irrigation protocols on self-expanding Smart-Seal obturation system: A scanning electron microscopic push-out bond strength study

    Science.gov (United States)

    Hegde, Vibha; Arora, Shashank

    2015-01-01

    Introduction: The aim of this study was to evaluate the effect of different final irrigation activation techniques affect the bond strength of self-expanding Smart-Seal obturation at the different thirds of root canal space. Materials and Methods: One hundred single-rooted human teeth were prepared using the Pro-Taper system to size F3, and a final irrigation regimen using 3% sodium hypochlorite and 17% EDTA was performed. The specimens were randomly divided into five groups (n = 20) according to the final irrigation activation technique used as follows: No activation (control), manual dynamic activation (MDA), CanalBrush activation, ultrasonic activation (UA) and EndoActivator. Five specimens from each group were subjected to scanning electron microscopic observation for assessment of the smear layer removal after the final irrigation procedures. All remaining roots were then obturated with Smart-Seal obturation system. A push-out test was used to measure the bond strength between the root canal dentin and Smart-Seal paste. The data obtained from the push-out test were analyzed using two-way analysis of variance and Tukey post-hoc tests. Conclusions: It was observed that UA improved the bond strength of Smart-Seal obturation in the coronal and middle third and MDA/EndoActivator in the apical third of the root canal space. PMID:25684907

  3. Nonlinearities in Microwave Superconductivity

    OpenAIRE

    Ledenyov, Dimitri O.; Ledenyov, Viktor O.

    2012-01-01

    The research is focused on the modeling of nonlinear properties of High Temperature Superconducting (HTS) thin films, using Bardeen, Cooper, Schrieffer and Lumped Element Circuit theories, with purpose to enhance microwave power handling capabilities of microwave filters and optimize design of microwave circuits in micro- and nano- electronics.

  4. Microwave Radiometer (MWR) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Morris, VR

    2006-08-01

    The Microwave Radiometer (MWR) provides time-series measurements of column-integrated amounts of water vapor and liquid water. The instrument itself is essentially a sensitive microwave receiver. That is, it is tuned to measure the microwave emissions of the vapor and liquid water molecules in the atmosphere at specific frequencies.

  5. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

    of complex electromagnetic problems. The first part of this book is devoted to the advances in the analysis techniques such as method of moments, finite-difference time-domain method, boundary perturbation theory, Fourier analysis, mode-matching method, and analysis based on circuit theory. These techniques...... microstrip lines (MSL), slot waveguides, substrate integrated waveguides (SIW), vertical transmission lines in multilayer media as well as MSL to SIW and MSL to slot line transitions. Impedance matching is an important aspect in the design of microwave circuitry since impedance mismatches may severely......-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...

  6. Thyroid Scan and Uptake

    Science.gov (United States)

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

  7. 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.

  8. Snowmelt and Surface Freeze/Thaw Timings over Alaska derived from Passive Microwave Observations using a Wavelet Classifier

    Science.gov (United States)

    Steiner, N.; McDonald, K. C.; Dinardo, S. J.; Miller, C. E.

    2015-12-01

    Arctic permafrost soils contain a vast amount of organic carbon that will be released into the atmosphere as carbon dioxide or methane when thawed. Surface to air greenhouse gas fluxes are largely dependent on such surface controls as the frozen/thawed state of the snow and soil. Satellite remote sensing is an important means to create continuous mapping of surface properties. Advances in the ability to determine soil and snow freeze/thaw timings from microwave frequency observations improves upon our ability to predict the response of carbon gas emission to warming through synthesis with in-situ observation, such as the 2012-2015 Carbon in Arctic Reservoir Vulnerability Experiment (CARVE). Surface freeze/thaw or snowmelt timings are often derived using a constant or spatially/temporally variable threshold applied to time-series observations. Alternately, time-series singularity classifiers aim to detect discontinuous changes, or "edges", in time-series data similar to those that occur from the large contrast in dielectric constant during the freezing or thaw of soil or snow. We use multi-scale analysis of continuous wavelet transform spectral gradient brightness temperatures from various channel combinations of passive microwave radiometers, Advanced Microwave Scanning Radiometer (AMSR-E, AMSR2) and Special Sensor Microwave Imager (SSM/I F17) gridded at a 10 km posting with resolution proportional to the observational footprint. Channel combinations presented here aim to illustrate and differentiate timings of "edges" from transitions in surface water related to various landscape components (e.g. snow-melt, soil-thaw). To support an understanding of the physical basis of observed "edges" we compare satellite measurements with simple radiative transfer microwave-emission modeling of the snow, soil and vegetation using in-situ observations from the SNOw TELemetry (SNOTEL) automated weather stations. Results of freeze/thaw and snow-melt timings and trends are

  9. Color sensing under microwaves

    Science.gov (United States)

    Choudhury, Debesh

    2013-09-01

    Inspired by recent results of artificial color due to Caulfield, we carry out intuitive experimental investigations on color sensing under microwave illumination. Experiemnts have been carried out using a Gunn diode as the microwave source and a microwave diode as a detector. More precise experimental studies have also been carried out utilizing a vector network analyzer. Preliminary results of the experiments validate the feasibility of sensing and discriminating otherwise visual colors under microwave illumination. Caulfield's presumption possibly paves the way for artificial color perception using microwaves.

  10. Airborne microwave radiometric imaging system

    Science.gov (United States)

    Guo, Wei; Li, Futang; Zhang, Zuyin

    1999-09-01

    A dual channel Airborne Microwave Radiometric Imaging system (AMRI) was designed and constructed for regional environment mapping. The system operates at 35GHz, which collects radiation at horizontal and vertical polarized channels. It runs at mechanical conical scanning with 45 degrees incidence angle. Two Cassegrain antennas with 1.5 degrees beamwidth scan the scene alternately and two pseudo- color images of two channels are displayed on the screen of PC in real time. Simultaneously, all parameters of flight and radiometric data are sorted in hard disk for post- processing. The sensitivity of the radiometer (Delta) T equals 0.16K. A new displaying method, unequal size element arc displaying method, is used in image displaying. Several experiments on mobile tower were carried out and the images demonstrate that the AMRI is available to work steadily and accurately.

  11. High brightness microwave lamp

    Science.gov (United States)

    Kirkpatrick, Douglas A.; Dolan, James T.; MacLennan, Donald A.; Turner, Brian P.; Simpson, James E.

    2003-09-09

    An electrodeless microwave discharge lamp includes a source of microwave energy, a microwave cavity, a structure configured to transmit the microwave energy from the source to the microwave cavity, a bulb disposed within the microwave cavity, the bulb including a discharge forming fill which emits light when excited by the microwave energy, and a reflector disposed within the microwave cavity, wherein the reflector defines a reflective cavity which encompasses the bulb within its volume and has an inside surface area which is sufficiently less than an inside surface area of the microwave cavity. A portion of the reflector may define a light emitting aperture which extends from a position closely spaced to the bulb to a light transmissive end of the microwave cavity. Preferably, at least a portion of the reflector is spaced from a wall of the microwave cavity. The lamp may be substantially sealed from environmental contamination. The cavity may include a dielectric material is a sufficient amount to require a reduction in the size of the cavity to support the desired resonant mode.

  12. A microwave powered sensor assembly for microwave ovens

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a microwave powered sensor assembly for micro- wave ovens. The microwave powered sensor assembly comprises a microwave antenna for generating an RF antenna signal in response to microwave radiation at a predetermined excitation frequency. A dc power supply circuit...... in a microwave oven chamber....

  13. 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

  14. Helix Scan: A Scan Design for Diagnosis

    Institute of Scientific and Technical Information of China (English)

    WANG Fei; HU Yu; LI Xiaowei

    2007-01-01

    Scan design is a widely used design-for-testability technique to improve test quality and efficiency. For the scan-designed circuit, test and diagnosis of the scan chain and the circuit is an important process for silicon debug and yield learning. However, conventional scan designs and diagnosis methods abort the subsequent diagnosis process after diagnosing the scan chain if the scan chain is faulty. In this work, we propose a design-for-diagnosis scan strategy called helix scan and a diagnosis algorithm to address this issue. Unlike previous proposed methods, helix scan has the capability to carry on the diagnosis process without losing information when the scan chain is faulty. What is more, it simplifies scan chain diagnosis and achieves high diagnostic resolution as well as accuracy. Experimental results demonstrate the effectiveness of our design.

  15. 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

  16. Ground-Based Calibration Of A Microwave Landing System

    Science.gov (United States)

    Kiriazes, John J.; Scott, Marshall M., Jr.; Willis, Alfred D.; Erdogan, Temel; Reyes, Rolando

    1996-01-01

    System of microwave instrumentation and data-processing equipment developed to enable ground-based calibration of microwave scanning-beam landing system (MSBLS) at distances of about 500 to 1,000 ft from MSBLS transmitting antenna. Ensures accuracy of MSBLS near touchdown point, without having to resort to expense and complex logistics of aircraft-based testing. Modified versions prove useful in calibrating aircraft instrument landing systems.

  17. Using your microwave oven. Lesson 6, Microwave oven management

    OpenAIRE

    Woodard, Janice Emelie, 1929-

    1984-01-01

    Discusses cooking and reheating foods in microwave ovens, and adapting conventional recipes for the microwave. Revised Includes the publication: Adapting conventional recipes to microwave cooking : fact sheet 84 by Janice Woodard, Rebecca Lovingood, R.H. Trice.

  18. Microwave gyroscope-novel rotation sensor

    CERN Document Server

    Karapetyan, G G

    2000-01-01

    High performance microwave gyroscope (MG) is theoretically developed for the first time to our knowledge. MG is based on Sagnac effect in microwave ring resonator (RR), where a specially taylored phase shifter (PS) on the basis of surface acoustic waves is inserted. Due to that beat frequency becomes proportional to square (or cubic) root upon rotation rate and therefore hugely increases. In the result MG has few order higher sensitivity and dynamic range than state-of-the-art laser gyros, so it can serve as an advanced rotation sensor in navigation and fundamental sciences.

  19. Lumbar spine CT scan

    Science.gov (United States)

    CAT scan - lumbar spine; Computed axial tomography scan - lumbar spine; Computed tomography scan - lumbar spine; CT - lower back ... your breath for short periods of time. The scan should take only 10 to 15 minutes.

  20. 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.

  1. 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

  2. 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.

  3. Remote sensing of sea ice: advances during the DAMOCLES project

    Directory of Open Access Journals (Sweden)

    G. Heygster

    2012-12-01

    Full Text Available In the Arctic, global warming is particularly pronounced so that we need to monitor its development continuously. On the other hand, the vast and hostile conditions make in situ observation difficult, so that available satellite observations should be exploited in the best possible way to extract geophysical information. Here, we give a résumé of the sea ice remote sensing efforts of the European Union's (EU project DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies. In order to better understand the seasonal variation of the microwave emission of sea ice observed from space, the monthly variations of the microwave emissivity of first-year and multi-year sea ice have been derived for the frequencies of the microwave imagers like AMSR-E (Advanced Microwave Scanning Radiometer on EOS and sounding frequencies of AMSU (Advanced Microwave Sounding Unit, and have been used to develop an optimal estimation method to retrieve sea ice and atmospheric parameters simultaneously. In addition, a sea ice microwave emissivity model has been used together with a thermodynamic model to establish relations between the emissivities from 6 GHz to 50 GHz. At the latter frequency, the emissivity is needed for assimilation into atmospheric circulation models, but is more difficult to observe directly. The size of the snow grains on top of the sea ice influences both its albedo and the microwave emission. A method to determine the effective size of the snow grains from observations in the visible range (MODIS is developed and demonstrated in an application on the Ross ice shelf. The bidirectional reflectivity distribution function (BRDF of snow, which is an essential input parameter to the retrieval, has been measured in situ on Svalbard during the DAMOCLES campaign, and a BRDF model assuming aspherical particles is developed. Sea ice drift and deformation is derived from satellite observations with the scatterometer

  4. NOVEL MICROWAVE FILTER DESIGN TECHNIQUES.

    Science.gov (United States)

    ELECTROMAGNETIC WAVE FILTERS, MICROWAVE FREQUENCY, PHASE SHIFT CIRCUITS, BANDPASS FILTERS, TUNED CIRCUITS, NETWORKS, IMPEDANCE MATCHING , LOW PASS FILTERS, MULTIPLEXING, MICROWAVE EQUIPMENT, WAVEGUIDE FILTERS, WAVEGUIDE COUPLERS.

  5. Scanning measurement testbed for advanced nondestructive evaluation

    OpenAIRE

    Horne, Michael R

    1990-01-01

    New materials and manufacturing processes, and the quest for economy and user safety, have necessitated the development of nondestructive testing methods to quantify the life and reliability of a product during manufacture and service. Described herein, is a testbed to be used in the research and development of these testing methods. A brief motivation for using ultrasonics applied to nondestructive evaluation is followed by a chapter on the feasibility of using a unique testing method and an...

  6. The Expected Impacts of NPOESS Microwave and Infrared Sounder Radiances on Operational Numerical Weather Prediction and Data Assimilation Systems

    Science.gov (United States)

    Swadley, S. D.; Baker, N.; Derber, J.; Collard, A.; Hilton, F.; Ruston, B.; Bell, W.; Candy, B.; Kleespies, T. J.

    2009-12-01

    The NPOESS atmospheric sounding functionality will be accomplished using two separate sensor suites, the combined infrared (IR) and microwave (MW) sensor suite (CrIMSS), and the Microwave Imager/Sounder (MIS) instrument. CrIMSS consists of the Cross Track Infrared Sounder (CrIS) and the cross track Advanced Technology Microwave Sounder (ATMS), and is scheduled to fly on the NPOESS Preparatory Project (NPP), and NPOESS operational flight units C1 and C3. The MIS is a conical scanning polarimetric imager and sounder patterned after the heritage WindSat, and DMSP Special Sensor Microwave Imagers and Sounders (SSMI and SSMIS), and is scheduled for flight units C2, C3 and C4. ATMS combines the current operational Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sounder (MHS), but with an additional channel in the 51.76 GHz oxygen absorption region and 3 additional channels in the 165.5 and 183 GHz water vapor absorption band. CrIS is a Fourier Transform Spectrometer and will provide 159 shortwave IR channels, 433 mid-range IR channels, and 713 longwave IR channels. The heritage sensors for CrIS are the NASA Advanced Infrared Sounder (AIRS) and the MetOp-A Infrared Atmospheric Sounding Interferometer (IASI). Both AIRS and IASI are high quality, high spectral resolution sounders which represent a significant improvement in the effective vertical resolution over previous IR sounders. This presentation will give an overview of preparations underway for day-1 monitoring of NPP/NPOESS radiances, and subsequent operational radiance assimilation. These preparations capitalize on experience gained during the pre-launch preparations, sensor calibration/validation and operational assimilation for the heritage sensors. One important step is to use pre-flight sensor channel specifications, noise estimates and knowledge of the antenna patterns, to generate and test proxy NPP/NPOESS sensor observations in existing assimilation systems. Other critical factors for

  7. Daily precipitation estimation through different microwave sensors: Verification study over Italy

    Science.gov (United States)

    Ciabatta, Luca; Marra, Anna Cinzia; Panegrossi, Giulia; Casella, Daniele; Sanò, Paolo; Dietrich, Stefano; Massari, Christian; Brocca, Luca

    2017-02-01

    The accurate estimation of rainfall from remote sensing is of paramount importance for many applications as, for instance, the mitigation of natural hazards like floods, droughts, and landslides. Traditionally, microwave observations in the frequency between 10 and 183 GHz are used for estimating rainfall based on the direct interaction of radiation with the hydrometeors within precipitating clouds in a so-called top-down approach. Recently, a bottom-up approach was proposed that uses satellite soil moisture products derived from microwave observations (nature. In this study, we perform a long-term (3 years) assessment of different satellite rainfall products exploiting the full range of microwave frequencies over Italy. Specifically, the integration of two top-down algorithms (CDRD, Cloud Dynamics and Radiation Database, and PNPR, Passive microwave Neural network Precipitation Retrieval) for estimating rainfall from conically and cross-track scanning radiometers, and one bottom-up algorithm (SM2RAIN) applied to the Advanced SCATterometer soil moisture product is carried out. The performances of the products, individually and merged together, are assessed at daily time scale. The integration of top-down and bottom-up approaches provides the highest performance both in terms of continuous and categorical scores (i.e., median correlation coefficient and root mean square error values equal to 0.71 and 6.62 mm, respectively). In such a combination, the limitations of the two approaches are compensated allowing a better estimation of ground accumulated rainfall through SM2RAIN while, overcoming the limitations of rainfall estimation for intense events during wet conditions through CDRD-PNPR product. The accuracy and the reliability of the merged product open new possibilities for their testing in hydrological applications, such as the monitoring and prediction of floods and droughts over large areas, including regions where ground-based measurements are sparse or not

  8. 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.

  9. 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

  10. Microwave Enhanced Reactive Distillation

    NARCIS (Netherlands)

    Altman, E.

    2011-01-01

    The application of electromagnetic irradiation in form of microwaves (MW) has gathered the attention of the scientific community in recent years. MW used as an alternative energy source for chemical syntheses (microwave chemistry) can provide clear advantages over conventional heating methods in ter

  11. The Cosmic Microwave Background

    OpenAIRE

    Silk, Joseph

    2002-01-01

    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.

  12. Automatic Ultrasound Scanning

    DEFF Research Database (Denmark)

    Moshavegh, Ramin

    Medical ultrasound has been a widely used imaging modality in healthcare platforms for examination, diagnostic purposes, and for real-time guidance during surgery. However, despite the recent advances, medical ultrasound remains the most operator-dependent imaging modality, as it heavily relies...... on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

  13. Lung gallium scan

    Science.gov (United States)

    Gallium 67 lung scan; Lung scan; Gallium scan - lung; Scan - lung ... Gallium is injected into a vein. The scan will be taken 6 to 24 hours after the gallium is injected. (Test time depends on whether your condition is acute or chronic .) ...

  14. The microwave absorption of ceramic-cup microwave ion source

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An experiment system of ceramic-cup microwave ion source has been built here. Its microwave absorption efficiency as a function of the magnetic field and the pressure is presented. When the microwave incident power is 300~500W the microwave absorption efficiencies are more than 90% if the system is optimized and the magnetic field at the microwave window is 0.095T.

  15. 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), ...

  16. 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.

  17. 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, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  18. 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.

  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. 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...

  1. The Microwave Hall Effect

    OpenAIRE

    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 ...

  2. Monolithic microwave integrated circuits

    Science.gov (United States)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  3. Scanning probe microscopy competency development

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, M.E.; Reagor, D.W.; Jia, Quan Xi [and others

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The project collaborators developed an ultra-high vacuum scanning tunneling microscope (UHV-STM) capability, integrated it with existing scanning probe microscopes, and developed new, advanced air-based scanning force techniques (SPMs). Programmatic, basic, and industrially related laboratory research requires the existence of SPMs, as well as expertise capable of providing local nano-scale information. The UHV-STM capability, equipped with load-lock system and several surface science techniques, will allow introduction, examination, and reaction of surfaces prepared under well-controlled vacuum conditions, including the examination of morphology and local bonding associated with the initial stages of film growth under controlled growth conditions. The resulting capabilities will enable the authors to respond to a variety of problems requiring local characterization of conducting and nonconducting surfaces in liquids, air, and UHV.

  4. Microwave absorption of nanoscale CoNi powders

    Science.gov (United States)

    Kurlyandskaya, G. V.; Bhagat, S. M.; Luna, C.; Vazquez, M.

    2006-05-01

    Ferromagnetic resonance (FMR) and microwave magnetoabsorption can be expected to be powerful tools for characterization of magnetic nanoparticles. In the present work, we have studied the FMR and magnetic field dependence of nonresonant microwave losses in CoNi nanoparticles of about 45, 100, and 200 nm caliper sizes prepared by the polyol technique. Contrary to our expectation, FMR lines, although wide, show that the particles are not truly spherical. Subsequent scanning and transmission electron microscopy investigations have confirmed this finding. Further, as before, all the powders are found to have large zero field absorption which reduces on application of a direct current (dc) field parallel to the microwave magnetic field but is relatively insensitive to a dc field if the powder is located in the microwave electric field, hence defining a magnetoimpedance for the system.

  5. 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.

  6. Relief Restoration of Complicated form Objects by Monochromatic Microwave Radiation

    Directory of Open Access Journals (Sweden)

    Kuzmenko Ivan

    2016-01-01

    Full Text Available Article demonstrates possibility of monochromatic radiation usage for relief restoration. There is a problem with restoration when scanned object is not flat and it is not parallel to the scanning plane. It was discovered that two-dimensional phase distribution could be applied for distance determination. It is reliable way to solve problems listed above. In conclusion offered methods allow monochromatic microwave radiation usage for screening system development.

  7. Satellite microwave assessment of Northern Hemisphere lake ice phenology from 2002 to 2015

    Science.gov (United States)

    Du, Jinyang; Kimball, John S.; Duguay, Claude; Kim, Youngwook; Watts, Jennifer D.

    2017-01-01

    A new automated method enabling consistent satellite assessment of seasonal lake ice phenology at 5 km resolution was developed for all lake pixels (water coverage ≥ 90 %) in the Northern Hemisphere using 36.5 GHz H-polarized brightness temperature (Tb) observations from the Advanced Microwave Scanning Radiometer for EOS and Advanced Microwave Scanning Radiometer 2 (AMSR-E/2) sensors. The lake phenology metrics include seasonal timing and duration of annual ice cover. A moving t test (MTT) algorithm allows for automated lake ice retrievals with daily temporal fidelity and 5 km resolution gridding. The resulting ice phenology record shows strong agreement with available ground-based observations from the Global Lake and River Ice Phenology Database (95.4 % temporal agreement) and favorable correlations (R) with alternative ice phenology records from the Interactive Multisensor Snow and Ice Mapping System (R = 0.84 for water clear of ice (WCI) dates; R = 0.41 for complete freeze over (CFO) dates) and Canadian Ice Service (R = 0.86 for WCI dates; R = 0.69 for CFO dates). Analysis of the resulting 12-year (2002-2015) AMSR-E/2 ice record indicates increasingly shorter ice cover duration for 43 out of 71 (60.6 %) Northern Hemisphere lakes examined, with significant (p regional trends toward earlier ice melting for only five lakes. Higher-latitude lakes reveal more widespread and larger trends toward shorter ice cover duration than lower-latitude lakes, consistent with enhanced polar warming. This study documents a new satellite-based approach for rapid assessment and regional monitoring of seasonal ice cover changes over large lakes, with resulting accuracy suitable for global change studies.

  8. Estimating Soil Moisture from Satellite Microwave Observations

    Science.gov (United States)

    Owe, M.; VandeGriend, A. A.; deJeu, R.; deVries, J.; Seyhan, E.

    1998-01-01

    Cooperative research in microwave remote sensing between the Hydrological Sciences Branch of the NASA Goddard Space Flight Center and the Earth Sciences Faculty of the Vrije Universiteit Amsterdam began with the Botswana Water and Energy Balance Experiment and has continued through a series of highly successful International Research Programs. The collaboration between these two research institutions has resulted in significant scientific achievements, most notably in the area of satellite-based microwave remote sensing of soil moisture. The Botswana Program was the first joint research initiative between these two institutions, and provided a unique data base which included historical data sets of Scanning Multifrequency Microwave Radiometer (SN4NM) data, climate information, and extensive soil moisture measurements over several large experimental sites in southeast Botswana. These data were the basis for the development of new approaches in physically-based inverse modelling of soil moisture from satellite microwave observations. Among the results from this study were quantitative estimates of vegetation transmission properties at microwave frequencies. A single polarization modelling approach which used horizontally polarized microwave observations combined with monthly composites of Normalized Difference Vegetation Index was developed, and yielded good results. After more precise field experimentation with a ground-based radiometer system, a dual-polarization approach was subsequently developed. This new approach realized significant improvements in soil moisture estimation by satellite. Results from the Botswana study were subsequently applied to a desertification monitoring study for the country of Spain within the framework of the European Community science research programs EFEDA and RESMEDES. A dual frequency approach with only microwave data was used for this application. The Microwave Polarization Difference Index (MPDI) was calculated from 37 GHz data

  9. Microwave Oven Observations.

    Science.gov (United States)

    Sumrall, William J.; Richardson, Denise; Yan, Yuan

    1998-01-01

    Explains a series of laboratory activities which employ a microwave oven to help students understand word problems that relate to states of matter, collect data, and calculate and compare electrical costs to heat energy costs. (DDR)

  10. 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...

  11. 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...

  12. 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...

  13. Microwave system engineering principles

    CERN Document Server

    Raff, Samuel J

    1977-01-01

    Microwave System Engineering Principles focuses on the calculus, differential equations, and transforms of microwave systems. This book discusses the basic nature and principles that can be derived from thermal noise; statistical concepts and binomial distribution; incoherent signal processing; basic properties of antennas; and beam widths and useful approximations. The fundamentals of propagation; LaPlace's Equation and Transmission Line (TEM) waves; interfaces between homogeneous media; modulation, bandwidth, and noise; and communications satellites are also deliberated in this text. This bo

  14. 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           �...

  15. 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.

  16. Conventional cerebrospinal fluid scanning

    Energy Technology Data Exchange (ETDEWEB)

    Schicha, H.

    1985-06-01

    Conventional cerebrospinal fluid scanning (CSF scanning) today is mainly carried out in addition to computerized tomography to obtain information about liquor flow kinetics. Especially in patients with communicating obstructive hydrocephalus, CSF scanning is clinically useful for the decision for shunt surgery. In patients with intracranial cysts, CSF scanning can provide information about liquor circulation. Further indications for CSF scanning include the assessment of shunt patency especially in children, as well as the detection and localization of cerebrospinal fluid leaks.

  17. 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...

  18. 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.

  19. Microwave sintering studies on low loss (Zn, Mg)TiO3 dielectric resonator materials.

    Science.gov (United States)

    Sirugudu, Roopas Kiran; Vemuri, Rama Krishna Murthy; Murty, B S

    2013-01-01

    Low dielectric loss Zn07Mg0.3TiO3 and MgTiO3 microwave dielectric resonators were prepared by the conventional solid state reaction method. The microwave interaction with these materials has been studied using both single-mode and multimode microwave furnaces operating at a frequency of 2.45 GHz. Microwave sintering could be achieved using a multimode microwave furnace only, whereas, interaction with a single-mode furnace showed plasma generation. Phase formation was observed by X-ray diffraction. Microwave dielectric characteristics such as dielectric constant (epsilon'), quality factor (Q x f) and temperature coefficient of resonant frequency (tauf) of microwave sintered samples were measured using a vector network analyzer and compared with conventional sintered ones. Microstructure of all the conventional and microwave sintered samples was observed using high resolution scanning electron microscope. Although epsilon' and tauf of the conventional and microwave sintered samples are found to be comparable, the quality factor (the vital characteristic of dielectric resonators) of microwave sintered samples are observed to be much lower than those obtained by conventional sintering. The difference in these values is discussed with respect to the grain size.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    J. Röhrs

    2012-03-01

    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 wider than 3 km in the entire Arctic Ocean. The algorithm detects 50 % of the lead area that was visible in optical MODIS satellite images. Passive microwave imagery from the Advanced Microwave Scanning Radiometer – Earth Observation System (AMSR-E is used, allowing daily observations due to the fact that AMSR-E does not depend on daylight or cloud conditions. Using the unique signatures of thin ice in the brightness temperature ratio between the 89 GHz and 19 GHz channels, the algorithm is able to detect thin ice areas in the ice cover and is optimized to detect leads. Leads are mapped for the period from 2002 to 2011 excluding the summer months, and validated qualitatively by using MODIS, Envisat ASAR, and CryoSat-2 data. Several frequently recurring large scale lead patterns are found, especially in regions where sea ice is known to drift out of the Arctic Ocean.

  2. [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.

  3. 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.; Goodman, Michael

    2006-01-01

    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 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.

  4. A Brightness-Temperature-Variance-Based Passive Microwave Algorithm for Monitoring Soil Freeze/Thaw State on the Tibetan Plateau

    Science.gov (United States)

    Han, M.; Yang, K.; Qin, J.; Jin, R.; Ma, Y.; Wen, J.; Chen, Y.; Zhao, L.; La, Z.; Tang, W.

    2014-12-01

    The land surface on the Tibetan Plateau experiences typical diurnal and seasonal freeze/thaw processes that play important roles in the regional water and energy exchanges, and recent passive microwave satellites provide opportunities to detect the soil state for the unique region. With the support of three soil moisture and temperature networks in the Tibetan Plateau, a dual-index microwave algorithm with AMSR-E (Advanced Microwave Scanning Radiometer-Earth Observing System) data is developed for the detection of soil surface freeze/thaw state. One index is the standard deviation index (SDI) of brightness temperature (TB), which is defined as the standard deviation of horizontally polarized brightness temperatures at all AMSR-E frequencies. It is the major index and is used to reflect the reduction of liquid water content after soils get frozen. The other index is the 36.5 GHz vertically-polarized brightness temperature, which is linearly correlated with ground temperature and thus is utilized to detect it. The threshold values of the two indices (SDI and the brightness temperature at 36.5 GHz vertically-polarized) are determined based on a part of in situ data from the network located in a semi-arid climate, and the algorithm was validated against other in situ data from this network. Further validations were conducted based on the other two networks located in different climates (semi-humid and arid, respectively). Results show that this algorithm has accuracy of more than 90% for the semi-humid and semi-arid regions, and misclassifications mainly occur at the transition period between unfrozen and frozen seasons. Nevertheless, the microwave signals have limited capability in identifying the soil surface freeze/thaw state in the arid region, because they can penetrate deep dry soils and thus embody the bulk information beneath the surface.

  5. Anomalous Microwave Emission

    CERN Document Server

    Kogut, A J

    1999-01-01

    Improved knowledge of diffuse Galactic emission is important to maximize the scientific return from scheduled CMB anisotropy missions. Cross-correlation of microwave maps with maps of the far-IR dust continuum show a ubiquitous microwave emission component whose spatial distribution is traced by far-IR dust emission. The spectral index of this emission, beta_{radio} = -2.2 (+0.5 -0.7) is suggestive of free-free emission but does not preclude other candidates. Comparison of H-alpha and microwave results show that both data sets have positive correlations with the far-IR dust emission. Microwave data, however, are consistently brighter than can be explained solely from free-free emission traced by H-alpha. This ``anomalous'' microwave emission can be explained as electric dipole radiation from small spinning dust grains. The anomalous component at 53 GHz is 2.5 times as bright as the free-free emission traced by H-alpha, providing an approximate normalization for models with significant spinning dust emission.

  6. 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...

  7. 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 ...

  8. Satellite Microwave Remote Sensing for Environmental Modeling of Mosquito Population Dynamics

    Science.gov (United States)

    Chuang, Ting-Wu; Henebry, Geoffrey M.; Kimball, John S.; VanRoekel-Patton, Denise L.; Hildreth, Michael B.; Wimberly, Michael C.

    2012-01-01

    Environmental variability has important influences on mosquito life cycles and understanding the spatial and temporal patterns of mosquito populations is critical for mosquito control and vector-borne disease prevention. Meteorological data used for model-based predictions of mosquito abundance and life cycle dynamics are typically acquired from ground-based weather stations; however, data availability and completeness are often limited by sparse networks and resource availability. In contrast, environmental measurements from satellite remote sensing are more spatially continuous and can be retrieved automatically. This study compared environmental measurements from the NASA Advanced Microwave Scanning Radiometer on EOS (AMSR-E) and in situ weather station data to examine their ability to predict the abundance of two important mosquito species (Aedes vexans and Culex tarsalis) in Sioux Falls, South Dakota, USA from 2005 to 2010. The AMSR-E land parameters included daily surface water inundation fraction, surface air temperature, soil moisture, and microwave vegetation opacity. The AMSR-E derived models had better fits and higher forecasting accuracy than models based on weather station data despite the relatively coarse (25-km) spatial resolution of the satellite data. In the AMSR-E models, air temperature and surface water fraction were the best predictors of Aedes vexans, whereas air temperature and vegetation opacity were the best predictors of Cx. tarsalis abundance. The models were used to extrapolate spatial, seasonal, and interannual patterns of climatic suitability for mosquitoes across eastern South Dakota. Our findings demonstrate that environmental metrics derived from satellite passive microwave radiometry are suitable for predicting mosquito population dynamics and can potentially improve the effectiveness of mosquito-borne disease early warning systems. PMID:23049143

  9. 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

  10. 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.

  11. Microwave Sintering of Silver Nanoink for Radio Frequency Applications.

    Science.gov (United States)

    Kim, Kwang-Seok; Park, Bum-Geun; Jung, Kwang-Ho; Kim, Jong-Woong; Jeong, Myung Yung; Jung, Seung-Boo

    2015-03-01

    Microwave sintering is a promising method for low-temperature processes, as it provides advantages such as uniform, fast, and volumetric heating. In this study, we investigated the electrical characteristics of inkjet-printed silver (Ag) circuits sintered by microwaves. The microstructural evolutions of inkjet-printed Ag circuits sintered at various temperatures for different durations were observed with a field emission scanning electron microscope. The electrical properties of the inkjet-printed Ag circuits were analysed by electrical resistivity measurements and radio frequency properties including scattering-parameters in the frequency range of 20 MHz to 20 GHz. The experimental results show that the signal losses of the Ag circuits sintered by microwave heating were lower than those sintered by conventional heating as microwave heating led to granular films which were nearly fully sintered without pores on the surfaces. When the inkjet-printed Ag circuits were sintered by microwaves at 300 °C for 4 min, their electrical resistivity was 5.1 µΩ cm, which is 3.2 times larger than that of bulk Ag. Furthermore, microwave sintering at 150 °C for 4 min achieved much lower signal losses (1.1 dB at 20 GHz) than conventional sintering under the same conditions.

  12. 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...

  13. 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.

  14. Physics of the Microwave Oven

    Science.gov (United States)

    Vollmer, Michael

    2004-01-01

    This is the first of two articles about the physics of microwave ovens. This article deals with the generation of microwaves in the oven and includes the operation of the magnetrons, waveguides and standing waves in resonant cavities. It then considers the absorption of microwaves by foods, discussing the dielectric relaxation of water,…

  15. 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...

  16. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  17. 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 care provider injects ...

  18. 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

  19. 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...

  20. 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.

  1. 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.

  2. 微波协同树脂催化合成酯类化合物的研究进展%Research advance in microwave assisted synthesis of esters catalysized by resin

    Institute of Scientific and Technical Information of China (English)

    李忠军; 黎彧; 黄利; 方楚生; 周丽琴; 彭志; 赖志彬

    2011-01-01

    Esters are important fine chemicals which are widely used in perfume, antiseptic, antioxidant, plastic and medicine, etc. The microwave assisted synthesis of esters catalysized by resin have the advantages such as less time, efficiency, low energy consumption and safety compared with the traditional process. This article reviewed the research progress of microwave assisted synthesis of esters catalysized by resin and its future development.%酯类是重要的精细化学品,广泛用于香料、防腐剂、抗氧剂、塑料及药物等方面.传统方法合成酯类具有反应时间长、产率低、污染大及后处理困难等缺点,微波协同树脂催化合成酯类具有反应快、高效、能耗低及安全等优点.该文综述了微波协同树脂催化合成酯类的研究进展,并展望该方法在酯类合成中的发展前景.

  3. De-noising of microwave satellite soil moisture time series

    Science.gov (United States)

    Su, Chun-Hsu; Ryu, Dongryeol; Western, Andrew; Wagner, Wolfgang

    2013-04-01

    The use of satellite soil moisture data for scientific and operational hydrologic, meteorological and climatological applications is advancing rapidly due to increasing capability and temporal coverage of current and future missions. However evaluation studies of various existing remotely-sensed soil moisture products from these space-borne microwave sensors, which include AMSR-E (Advanced Microwave Scanning Radiometer) on Aqua satellite, SMOS (Soil Moisture and Ocean Salinity) mission and ASCAT (Advanced Scatterometer) on MetOp-A satellite, found them to be significantly different from in-situ observations, showing large biases and different dynamic ranges and temporal patterns (e.g., Albergel et al., 2012; Su et al., 2012). Moreover they can have different error profiles in terms of bias, variance and correlations and their performance varies with land surface characteristics (Su et al., 2012). These severely impede the effort to use soil moisture retrievals from multiple sensors concurrently in land surface modelling, cross-validation and multi-satellite blending. The issue of systematic errors present in data sets should be addressed prior to renormalisation of the data for blending and data assimilation. Triple collocation estimation technique has successfully yielded realistic error estimates (Scipal et al., 2008), but this method relies on availability of large number of coincident data from multiple independent satellite data sets. In this work, we propose, i) a conceptual framework for distinguishing systematic periodic errors in the form of false spectral resonances from non-systematic errors (stochastic noise) in remotely-sensed soil moisture data in the frequency domain; and ii) the use of digital filters to reduce the variance- and correlation-related errors in satellite data. In this work, we focus on the VUA-NASA (Vrije Universiteit Amsterdam with NASA) AMSR-E, CATDS (Centre National d'Etudes Spatiales, CNES) SMOS and TUWIEN (Vienna University of

  4. Present and future applications of analogue microwave photonics

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso

    2009-01-01

    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...... for commercial applications as well as the challenges and research opportunities to be pursued to make it reality....

  5. Microwave Plasma Hydrogen Recovery System

    Science.gov (United States)

    Atwater, James; Wheeler, Richard, Jr.; Dahl, Roger; Hadley, Neal

    2010-01-01

    A microwave plasma reactor was developed for the recovery of hydrogen contained within waste methane produced by Carbon Dioxide Reduction Assembly (CRA), which reclaims oxygen from CO2. Since half of the H2 reductant used by the CRA is lost as CH4, the ability to reclaim this valuable resource will simplify supply logistics for longterm manned missions. Microwave plasmas provide an extreme thermal environment within a very small and precisely controlled region of space, resulting in very high energy densities at low overall power, and thus can drive high-temperature reactions using equipment that is smaller, lighter, and less power-consuming than traditional fixed-bed and fluidized-bed catalytic reactors. The high energy density provides an economical means to conduct endothermic reactions that become thermodynamically favorable only at very high temperatures. Microwave plasma methods were developed for the effective recovery of H2 using two primary reaction schemes: (1) methane pyrolysis to H2 and solid-phase carbon, and (2) methane oligomerization to H2 and acetylene. While the carbon problem is substantially reduced using plasma methods, it is not completely eliminated. For this reason, advanced methods were developed to promote CH4 oligomerization, which recovers a maximum of 75 percent of the H2 content of methane in a single reactor pass, and virtually eliminates the carbon problem. These methods were embodied in a prototype H2 recovery system capable of sustained high-efficiency operation. NASA can incorporate the innovation into flight hardware systems for deployment in support of future long-duration exploration objectives such as a Space Station retrofit, Lunar outpost, Mars transit, or Mars base. The primary application will be for the recovery of hydrogen lost in the Sabatier process for CO2 reduction to produce water in Exploration Life Support systems. Secondarily, this process may also be used in conjunction with a Sabatier reactor employed to

  6. Microwave Radiation Hazards

    Directory of Open Access Journals (Sweden)

    G. Subrahmanian

    1973-07-01

    Full Text Available Excessive exposure to microwave radiation could lead to biological damage. The criteria for maximum permissible exposure limits derived from experiments by several countries are discussed. Recommendations made for safety of operating personnel based on a recent protection survey are also presented.

  7. 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…

  8. 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.

  9. Microwave heating in solid-phase peptide synthesis.

    Science.gov (United States)

    Pedersen, Søren L; Tofteng, A Pernille; Malik, Leila; Jensen, Knud J

    2012-03-07

    The highly refined organic chemistry in solid-phase synthesis has made it the method of choice not only to assemble peptides but also small proteins - mainly on a laboratory scale but increasingly also on an industrial scale. While conductive heating occasionally has been applied to peptide synthesis, precise microwave irradiation to heat the reaction mixture during coupling and N(α)-deprotection has become increasingly popular. It has often provided dramatic reductions in synthesis times, accompanied by an increase in the crude peptide purity. Microwave heating has been proven especially relevant for sequences which might form β-sheet type structures and for sterically difficult couplings. The beneficial effect of microwave heating appears so far to be due to the precise nature of this type of heating, rather than a peptide-specific microwave effect. However, microwave heating as such is not a panacea for all difficulties in peptide syntheses and the conditions may need to be adjusted for the incorporation of Cys, His and Asp in peptides, and for the synthesis of, for example, phosphopeptides, glycopeptides, and N-methylated peptides. Here we provide a comprehensive overview of the advances in microwave heating for peptide synthesis, with a focus on systematic studies and general protocols, as well as important applications. The assembly of β-peptides, peptoids and pseudopeptides are also evaluated in this critical review (254 references).

  10. 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.

  11. Laser Scanning in Forests

    OpenAIRE

    Håkan Olsson; Juha Hyyppä; Markus Holopainen

    2012-01-01

    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 fore...

  12. 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

  13. Synthetic tests of passive microwave brightness temperature assimilation over snow covered land using machine learning algorithms

    Science.gov (United States)

    Forman, B. A.

    2015-12-01

    A novel data assimilation framework is evaluated that assimilates passive microwave (PMW) brightness temperature (Tb) observations into an advanced land surface model for the purpose of improving snow depth and snow water equivalent (SWE) estimates across regional- and continental-scales. The multifrequency, multipolarization framework employs machine learning algorithms to predict PMW Tb as a function of land surface model state information and subsequently merges the predicted PMW Tb with observed PMW Tb from the Advanced Microwave Scanning Radiometer (AMSR-E). The merging procedure is predicated on conditional probabilities computed within a Bayesian statistical framework using either an Ensemble Kalman Filter (EnKF) or an Ensemble Kalman Smoother (EnKS). The data assimilation routine produces a conditioned (updated) estimate of modeled SWE that is more accurate and contains less uncertainty than the model without assimilation. A synthetic case study is presented for select locations in North America that compares model results with and without assimilation against synthetic observations of snow depth and SWE. It is shown that the data assimilation framework improves modeled estimates of snow depth and SWE during both the accumulation and ablation phases of the snow season. Further, it is demonstrated that the EnKS outperforms the EnKF implementation due to its ability to better modulate high frequency noise into the conditioned estimates. The overarching findings from this study demonstrate the feasibility of machine learning algorithms for use as an observation model operator within a data assimilation framework in order to improve model estimates of snow depth and SWE across regional- and continental-scales.

  14. 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.

  15. Research progress and prospect of remote sensing with passive microwave from snow%积雪被动微波遥感研究进展与前景展望

    Institute of Scientific and Technical Information of China (English)

    刘宝康; 冯蜀青; 杜玉娥; 杨鑫光; 袁雷; 周刊社; 胡爱军

    2009-01-01

    Research progress of the passive microwave remote sensing for snow cover at home and abroad in recent years was overviewed, and common passive microwave sensors SMMR(Scanning Multichannel Microwave Radiometer), SSM/I(Special Sensor Microwave/Imager), AMSR-E (Advanced Microwave Scanning Radiometer-EOS) and MWRI(Microwave Radiation Imager)were compared for each other. Some problems were found as follows: 1) The discriminant threshold of dry snow and wet snow is influenced by many factors that do not determined still. 2) The measured value of snow depth can not by reflected by meteorological situation. 3) The resolution is not high enough to used in monitoring the shallow snow zone information. 4) It seems to be overestimated for range and depth of snow and so on. In addition, the accuracy of the inversion results was affected by snow density, particle size, precipitation, cold desert, vegetation, permafrost and other factors. Aim to further study intensively, passive microwave remote sensing of snow cover was prospected as follows: 1) To operational monitoring, visible light and passive microwave data should be integrated;2) Combination of remote sensing and geographic information systems would improve the accuracy and application breadth;3) Improvements of the algorithm, higher spatial resolution data of passive microwave AMSR-E, and passive microwave radiation imaginer MWRI of our FY3 satellite with the snow model would enhance importance of snow monitoring;4) Range of snow monitoring is more consistent with passive microwave remote sensing and MODIS visible light.The passive microwave remote sensing can play an alternative role when visible light images can not be obtained satisfactorly due to more clouds;and 5) Passive microwave remote sensing still have more issues in operational snow monitoring, continuous monitoring of ground operations and Algorithm improvement. Its validation is an important guarantee to improve the technology, which need to be verified in

  16. Bone scanning in otolaryngology.

    Science.gov (United States)

    Noyek, A M

    1979-09-01

    Modern radionuclide bone scanning has introduced a new concept in physiologic and anatomic diagnostic imaging to general medicine. As otolaryngologists must diagnose and treat disease in relation to the bony and/or cartilaginous supporting structures of the neurocranium and upper airway, this modality should be included in the otolaryngologist's diagnostic armamentarium. It is the purpose of this manuscript to study the specific applications of bone scanning to our specialty at this time, based on clinical experience over the past three years. This thesis describes the development of bone scanning in general (history of nuclear medicine and nuclear physics; history of bone scanning in particular). General concepts in nuclear medicine are then presented; these include a discussion of nuclear semantics, principles of radioactive emmissions, the properties 99mTc as a radionuclide, and the tracer principle. On the basis of these general concepts, specific concepts in bone scanning are then brought forth. The physiology of bone and the action of the bone scan agents is presented. Further discussion considers the availability and production of the bone scan agent, patient factors, the gamma camera, the triphasic bone scan and the ultimate diagnostic principle of the bone scan. Clinical applications of bone scanning in otolaryngology are then presented in three sections. Proven areas of application include the evaluation of malignant tumors of the head and neck, the diagnosis of temporomandibular joint disorders, the diagnosis of facial fractures, the evaluation of osteomyelitis, nuclear medicine imaging of the larynx, and the assessment of systemic disease. Areas of adjunctive or supplementary value are also noted, such as diagnostic imaging of meningioma. Finally, areas of marginal value in the application of bone scanning are described.

  17. Imaging Photon Lattice States by Scanning Defect Microscopy

    Science.gov (United States)

    Underwood, D. L.; Shanks, W. E.; Li, Andy C. Y.; Ateshian, Lamia; Koch, Jens; Houck, A. A.

    2016-04-01

    Microwave photons inside lattices of coupled resonators and superconducting qubits can exhibit surprising matterlike behavior. Realizing such open-system quantum simulators presents an experimental challenge and requires new tools and measurement techniques. Here, we introduce scanning defect microscopy as one such tool and illustrate its use in mapping the normal-mode structure of microwave photons inside a 49-site kagome lattice of coplanar waveguide resonators. Scanning is accomplished by moving a probe equipped with a sapphire tip across the lattice. This locally perturbs resonator frequencies and induces shifts of the lattice resonance frequencies, which we determine by measuring the transmission spectrum. From the magnitude of mode shifts, we can reconstruct photon field amplitudes at each lattice site and thus create spatial images of the photon-lattice normal modes.

  18. Microstructural and mechanical properties of camel longissimus dorsi muscle during roasting, braising and microwave heating.

    Science.gov (United States)

    Yarmand, M S; Nikmaram, P; Djomeh, Z Emam; Homayouni, A

    2013-10-01

    This study was conducted to investigate the effects of various heating methods, including roasting, braising and microwave heating, on mechanical properties and microstructure of longissimus dorsi (LD) muscle of the camel. Shear value and compression force increased during microwave heating more than roasting and braising. Results obtained from scanning electron microscopy (SEM) showed more damage from roasting than in either braising or microwave heating. Granulation and fragmentation were clear in muscle fibers after roasting. The perimysium membrane of connective tissue was damaged during braising, while roasting left the perimysium membrane largely intact. The mechanical properties and microstructure of muscle can be affected by changes in water content during cooking.

  19. Scanning laser Doppler vibrometry

    DEFF Research Database (Denmark)

    Brøns, Marie; Thomsen, Jon Juel

    With a Scanning Laser Doppler Vibrometer (SLDV) a vibrating surface is automatically scanned over predefined grid points, and data processed for displaying vibration properties like mode shapes, natural frequencies, damping ratios, and operational deflection shapes. Our SLDV – a PSV-500H from...

  20. 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...

  1. Optical Scanning Applications.

    Science.gov (United States)

    Wagner, Hans

    The successful use of optical scanning at the University of the Pacific (UOP) indicates that such techniques can simplify a number of administrative data processing tasks. Optical scanning is regularly used at UOP to assist with data processing in the areas of admissions, registration and grade reporting and also has applications for other tasks…

  2. 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.

  3. High RF Magnetic Field Near-Field Microwave Microscope

    Science.gov (United States)

    Tai, Tamin; Mircea, Dragos I.; Anlage, Steven M.

    2010-03-01

    Near-field microwave microscopes have been developed to quantitatively image RF and microwave properties of a variety of materials on deep sub-wavelength scales [1]. Microscopes that develop high-RF magnetic fields on short length scales are useful for examining the fundamental electrodynamic properties of superconductors [2]. We are creating a new class of near-field microwave microscopes that develop RF fields on the scale of 1 Tesla on sub-micron length scales. These microscopes will be employed to investigate defects that limit the RF properties of bulk Nb materials used in accelerator cavities, and the nonlinear Meissner effect in novel superconductors. Work funded by the US Department of Energy. [1] S. M. Anlage, V. V. Talanov, A. R. Schwartz, ``Principles of Near-Field Microwave Microscopy,'' in Scanning Probe Microscopy: Electrical and Electromechanical Phenomena at the Nanoscale, Volume 1, edited by S. V. Kalinin and A. Gruverman (Springer-Verlag, New York, 2007), pp. 215-253. [2] D. I. Mircea, H. Xu, S. M. Anlage, ``Phase-sensitive Harmonic Measurements of Microwave Nonlinearities in Cuprate Thin Films,'' Phys. Rev. B 80, 144505 (2009).

  4. Microwave Quantum Illumination

    Science.gov (United States)

    2016-07-29

    Microwave Quantum Illumination Shabir Barzanjeh,1 Saikat Guha,2 Christian Weedbrook,3 David Vitali,4 Jeffrey H. Shapiro,5 and Stefano Pirandola6...1Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany 2Quantum Information Processing Group, Raytheon BBN Technologies...6Department of Computer Science & York Centre for Quantum Technologies, University of York, York YO10 5GH, United Kingdom Quantum illumination is a quantum

  5. SUNIST Microwave Power System

    Institute of Scientific and Technical Information of China (English)

    Feng Songlin; Yang Xuanzong; Feng Chunhua; Wang Long; Rao Jun; Feng Kecheng

    2005-01-01

    Experiments on the start-up and formation of spherical tokamak plasmas by electron cyclotron heating alone without ohmic heating and electrode discharge assisted electron cyclotron wave current start-up will be carried out on the SUNIST (Sino United Spherical Tokamak) device.The 2.45 GHz/100 kW/30 ms microwave power system and 1000 V/50 A power supply for electrode discharge are ready for experiments with non-inductive current drive.

  6. Microwave Processing of Materials

    Science.gov (United States)

    1994-01-01

    Pennsylvania: Materials Research Society. Wagner, C., and W. Schottky. 1930. Zeitschrift fuer Physikalische Chemie. BL11:163. Walkiewicz, J. W., A. E. Clark...Science and Engineering. 66:468--469. Bloch, F. 1928. Zeitschrift fuer Physik. 52:555. Boch, P., N. Lequeux and P. Piluso. 1992. Reaction Sintering...Frankel, J. 1926. Zeitschrift fuer Physik. 35:652. Fukushima, H., T. Yamaka, and M. Matsui. 1990. Microwave Heating of Ceramics and its Application to

  7. LIDAR COMBINED SCANNING UNIT

    Directory of Open Access Journals (Sweden)

    V. V. Elizarov

    2016-11-01

    Full Text Available Subject of Research. The results of lidar combined scanning unit development for locating leaks of hydrocarbons are presented The unit enables to perform high-speed scanning of the investigated space in wide and narrow angle fields. Method. Scanning in a wide angular field is produced by one-line scanning path by means of the movable aluminum mirror with a frequency of 20Hz and amplitude of 20 degrees of swing. Narrowband scanning is performed along a spiral path by the deflector. The deflection of the beam is done by rotation of the optical wedges forming part of the deflector at an angle of ±50. The control function of the scanning node is performed by a specialized software product written in C# programming language. Main Results. This scanning unit allows scanning the investigated area at a distance of 50-100 m with spatial resolution at the level of 3 cm. The positioning accuracy of the laser beam in space is 15'. The developed scanning unit gives the possibility to browse the entire investigated area for the time not more than 1 ms at a rotation frequency of each wedge from 50 to 200 Hz. The problem of unambiguous definition of the beam geographical coordinates in space is solved at the software level according to the rotation angles of the mirrors and optical wedges. Lidar system coordinates are determined by means of GPS. Practical Relevance. Development results open the possibility for increasing the spatial resolution of scanning systems of a wide range of lidars and can provide high positioning accuracy of the laser beam in space.

  8. Microwave-Assisted Olefin Metathesis

    Science.gov (United States)

    Nicks, François; Borguet, Yannick; Sauvage, Xavier; Bicchielli, Dario; Delfosse, Sébastien; Delaude, Lionel; Demonceau, Albert

    Since the first reports on the use of microwave irradiation to accelerate organic chemical transformations, a plethora of papers have been published in this field. In most examples, microwave heating has been shown to dramatically reduce reaction times, increase product yields, and enhance product purity by reducing unwanted side reactions compared to conventional heating methods. The present contribution aims at illustrating the advantages of this technology in olefin metathesis and, when data are available, at comparing microwave-heated and conventionally heated experiments

  9. Microwave sterilization method and apparatus

    OpenAIRE

    V. N. Vasilenko; Minuhin, V. V.; Podorozhnyak, A. A.; Trubaev, S. I.

    1995-01-01

    Experience of industrially developed countries in utilization of microwave radiation has been analyzed. Apparatus for realization of microwave method of sterilization has been designed. A number of experiments for the estimation of bactericidal, sporacidal, and virusidal properties of microwave radiation action has been carried out in 3 to 13 cm wavelength band. B. Lycheniform shtumm G., B. Subtilis ATTC 6633, E. Coli ATTC 25922 and bacterial virus FX 174 were used as test microbes. Effect of...

  10. Nanoscale microwave imaging with a single electron spin in diamond

    OpenAIRE

    Appel, Patrick; Ganzhorn, Marc; Neu, Elke; Maletinsky, Patrick

    2015-01-01

    We report on imaging of microwave (MW) magnetic fields using a magnetometer based on the electron spin of a nitrogen vacancy center in diamond. We quantitatively image the magnetic field generated by high frequency (GHz) MW current with nanoscale resolution using a scanning probe technique. We demonstrate a MW magnetic field sensitivity in the range of a few nT/$\\sqrt{\\text{Hz}}$, polarization selection and broadband capabilities under ambient conditions and thereby establish the nitrogen vac...

  11. The Microwave SQUID Multiplexer

    Science.gov (United States)

    Mates, John Arthur Benson

    2011-12-01

    This thesis describes a multiplexer of Superconducting Quantum Interference Devices (SQUIDs) with low-noise, ultra-low power dissipation, and great scalability. The multiplexer circuit measures the magnetic flux in a large number of unshunted rf SQUIDs by coupling each SQUID to a superconducting microwave resonator tuned to a unique resonance frequency and driving the resonators from a common feedline. A superposition of microwave tones measures each SQUID simultaneously using only two coaxial cables between the cryogenic device and room temperature. This multiplexer will enable the instrumentation of arrays with hundreds of thousands of low-temperature detectors for new applications in cosmology, materials analysis, and nuclear non-proliferation. The driving application of the Microwave SQUID Multiplexer is the readout of large arrays of superconducting transition-edge sensors, by some figures of merit the most sensitive detectors of electromagnetic signals over a span of more than nine orders of magnitude in energy, from 40 GHz microwaves to 200 keV gamma rays. Modern transition-edge sensors have noise-equivalent power as low as 10-20 W / Hz1/2 and energy resolution as good as 2 eV at 6 keV. These per-pixel sensitivities approach theoretical limits set by the underlying signals, motivating a rapid increase in pixel count to access new science. Compelling applications, like the non-destructive assay of nuclear material for treaty verification or the search for primordial gravity waves from inflation use arrays of these detectors to increase collection area or tile a focal plane. We developed three generations of SQUID multiplexers, optimizing the first for flux noise 0.17 muPhi0 / Hz1/2, the second for input current noise 19 pA / Hz1/2, and the last for practical multiplexing of large arrays of cosmic microwave background polarimeters based on transition-edge sensors. Using the last design we demonstrated multiplexed readout of prototype polarimeters with the

  12. 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. [...

  13. Resonant scanning mechanism

    Science.gov (United States)

    Wallace, John; Newman, Mike; Gutierrez, Homero; Hoffman, Charlie; Quakenbush, Tim; Waldeck, Dan; Leone, Christopher; Ostaszewski, Miro

    2014-10-01

    Ball Aerospace & Technologies Corp. developed a Resonant Scanning Mechanism (RSM) capable of combining a 250- Hz resonant scan about one axis with a two-hertz triangular scan about the orthogonal axis. The RSM enables a rapid, high-density scan over a significant field of regard (FOR) while minimizing size, weight, and power requirements. The azimuth scan axis is bearing mounted allowing for 30° of mechanical travel, while the resonant elevation axis is flexure and spring mounted with five degrees of mechanical travel. Pointing-knowledge error during quiescent static pointing at room temperature across the full range is better than 100 μrad RMS per axis. The compact design of the RSM, roughly the size of a soda can, makes it an ideal mechanism for use on low-altitude aircraft and unmanned aerial vehicles. Unique aspects of the opto-mechanical design include i) resonant springs which allow for a high-frequency scan axis with low power consumption; and ii) an independent lower-frequency scan axis allowing for a wide FOR. The pointing control system operates each axis independently and employs i) a position loop for the azimuth axis; and ii) a unique combination of parallel frequency and amplitude control loops for the elevation axis. All control and pointing algorithms are hosted on a 200-MHz microcontroller with 516 KB of RAM on a compact 3"×4" digital controller, also of Ball design.

  14. 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.

  15. Study of the degradation behaviour of dimethoate under microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei [College of Chemistry and Chemical Engineering, Liaoning University, Shenyang 110036 (China)], E-mail: zhanglei63@126.com; Guo Xingjia; Yan Fei; Su Mingming; Li Ying [College of Chemistry and Chemical Engineering, Liaoning University, Shenyang 110036 (China)

    2007-11-19

    In this work, the degradation of dimethoate under microwave irradiation assisted advanced oxidation processes (MW/oxidants) were studied. The efficiencies of the degradation of dimethoate in dilute aqueous solutions for a variety of oxidants with or without MW irradiation were compared. The results showed that the synergistic effects between MW and K{sub 2}S{sub 2}O{sub 8} had high degradation efficiency for dimethoate. Simultaneously, UV/TiO{sub 2}/K{sub 2}S{sub 2}O{sub 8} photocatalytic oxidation degradation of dimethoate was investigated. The experimental results indicated that the method of microwave degradation of organic pollutants in the presence of oxidant could reduce reaction time and improve product yield. Microwave irradiation was an advisable choice for treating organic wastewaters and has a widely application perspective for non- or low-transparent and fuscous dye wastewaters.

  16. 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...

  17. CT scan of choristoma

    Energy Technology Data Exchange (ETDEWEB)

    Moriki, A.; Morimoto, M.; Sada, Y.; Kurisaka, M.; Mori, K.

    1987-02-01

    Choristoma is a rare tumor that occurs in the pituitary gland. The case presented here is a 44-year-old male. A plain CT scan demonstrated a slight high-density mass near the posterior clinoid of the sella turcica, while a moderate and homogeneous enhancing effect and a clear borderline were shown by an enhanced CT scan. A cornal CT scan study showed that the tumor extended from the intrasellar to the suprasellar region. The diagnosis of choristoma was made by means of histology.

  18. 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...

  19. Recent developments in the preparation and regeneration of activated carbons by microwaves.

    Science.gov (United States)

    Yuen, Foo Keng; Hameed, B H

    2009-07-30

    To date, microwave energy has been widely developed and applied to almost every field of chemistry. In many cases, microwave technology has proven to remarkably reducing costs, accelerating reaction rates, improving yields and selectively activating. This paper presents a state of art review of microwave technology, its background studies, fundamental chemistry and industrial applications. With the renaissance of activated carbon, there has been a steadily growing interest in this research field. The review provides a summary on recent development in preparation and regeneration of activated carbons. The key advance of introducing microwave energy has been highlighted relative to conventional methods. Moreover, the major drawbacks, challenges with its future expectation are presented and discussed. Conclusively, microwave energy is predicted to be a potentially viable and powerful replacement for fuel technology in various areas, while its progress represents an expanding field in the area of adsorption science.

  20. Cervical spine CT scan

    Science.gov (United States)

    ... defects of the cervical spine Bone problems Fracture Osteoarthritis Disc herniation Risks Risks of CT scans include: ... Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, ...

  1. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope. Specifications / Capabilities: Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  2. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  3. 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 ...

  4. Slow Scan Telemedicine

    Science.gov (United States)

    1984-01-01

    Originally developed under contract for NASA by Ball Bros. Research Corporation for acquiring visual information from lunar and planetary spacecraft, system uses standard closed circuit camera connected to a device called a scan converter, which slows the stream of images to match an audio circuit, such as a telephone line. Transmitted to its destination, the image is reconverted by another scan converter and displayed on a monitor. In addition to assist scans, technique allows transmission of x-rays, nuclear scans, ultrasonic imagery, thermograms, electrocardiograms or live views of patient. Also allows conferencing and consultation among medical centers, general practitioners, specialists and disease control centers. Commercialized by Colorado Video, Inc., major employment is in business and industry for teleconferencing, cable TV news, transmission of scientific/engineering data, security, information retrieval, insurance claim adjustment, instructional programs, and remote viewing of advertising layouts, real estate, construction sites or products.

  5. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... as an overactive thyroid gland, a condition called hyperthyroidism , cancer or other growths assess the nature of ... an x-ray or CT scan, surgeries or treatments using iodinated contrast material within the last two ...

  6. Photothermal imaging scanning microscopy

    Science.gov (United States)

    Chinn, Diane; Stolz, Christopher J.; Wu, Zhouling; Huber, Robert; Weinzapfel, Carolyn

    2006-07-11

    Photothermal Imaging Scanning Microscopy produces a rapid, thermal-based, non-destructive characterization apparatus. Also, a photothermal characterization method of surface and subsurface features includes micron and nanoscale spatial resolution of meter-sized optical materials.

  7. The conical scan radiometer

    Science.gov (United States)

    Prosch, T.; Hennings, D.

    1982-07-01

    A satellite-borne conical scan radiometer (CSR) is proposed, offering multiangular and multispectral measurements of Earth radiation fields, including the total radiances, which are not available from conventional radiometers. Advantages of the CSR for meteorological studies are discussed. In comparison to conventional cross track scanning instruments, the CSR is unique with respect to the selected picture element size which is kept constant by means of a specially shaped detector matrix at all scan angles. The conical scan mode offers the chance to improve angular sampling. Angular sampling gaps of previous satellite-borne radiometers can be interpolated and complemented by CSR data. Radiances are measured through 10 radiometric channels which are selected to study cloudiness, water vapor, ozone, surface albedo, ground and mean stratospheric temperature, and aerosols.

  8. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Uptake? A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) ... of thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that ...

  9. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... which are encased in metal and plastic and most often shaped like a box, attached to a ... will I experience during and after the procedure? Most thyroid scan and thyroid uptake procedures are painless. ...

  10. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? The thyroid scan is used to determine ... you are undergoing. top of page What does the equipment look like? Special camera or imaging devices ...

  11. Scanning laser Doppler vibrometry

    OpenAIRE

    2016-01-01

    With a Scanning Laser Doppler Vibrometer (SLDV) a vibrating surface is automatically scanned over predefined grid points, and data processed for displaying vibration properties like mode shapes, natural frequencies, damping ratios, and operational deflection shapes. Our SLDV – a PSV-500H from Polytec Inc. – was acquired and put to operation in October 2014, paid by a sub-donation of DKK 1,5 mill. of the total VILLUM CASMaT grant. Opening possibilities of measuring complicated vibration shapes...

  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. 肺通气灌注扫描在孕妇肺栓塞诊断中的研究进展%Research advance of lung ventilation perfusion scanning for diagnosis of pulmonary embolism in pregnant women

    Institute of Scientific and Technical Information of China (English)

    张泽明; 刘丽君; 杨泽西

    2014-01-01

    Pulmonary embolism is the primary cause of maternal death in western countries.If the pulmonary embolism of the pregnant women can not get timely diagnosis and treatment,the life safety of the pregnant women and fetus will be seriously threatened.At present,the lung ventilation perfusion scanning examination is recognized as the most sensitive and noninvasive diagnosis method of pulmonary embolism in the world.But this check is partially limited,considering the influence on the pregnant women and fetus.This article reviews the application progress of lung ventilation perfusion scanning in the pregnant women with pulmonary embolism.%在西方国家,肺栓塞是孕产妇死亡的首要原因,如肺栓塞的孕妇得不到及时的诊断和治疗,将严重威胁孕妇及胎儿的生命安全.肺通气灌注扫描显像检查是目前国际上公认的诊断肺栓塞的最敏感而无创的检查方法,但考虑到对孕妇及胎儿的影响,此检查受到了一定的限制.本文就肺通气灌注扫描显像检查在孕妇可疑肺栓塞中的应用进展作一综述.

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

    Science.gov (United States)

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

    2016-10-02

    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.

  15. 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

  16. More Experiments with Microwave Ovens

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter; Karstadt, Detlef

    2004-01-01

    Microwave ovens can be used to perform exciting demonstrations that illustrate a variety of physics topics. Experiments discussed here show superheating, visualize the inhomogeneous heating that takes place in a microwave and also show how to use a mobile phone to detect radiation leaking from the oven. Finally eggs can give some spectacular…

  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-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.

  19. Microwave plasma combustion of coal

    Energy Technology Data Exchange (ETDEWEB)

    P.M. Kanilo; V.I. Kazantsev; N.I. Rasyuk; K. Schuenemann; D.M. Vavriv [Institute of Machine Building Problems of the National Academy of Sciences of Ukraine, Kharkov (Ukraine)

    2003-01-01

    Microwave plasma is studied as an alternative to oil or gas fuel for ignition and stabilisation of burning of lean coal. The study is performed on an experimental set-up, which includes a burner with a microwave plasma generator, coal and air supply systems, and measurement equipment. Power and thermochemical characteristics of the coal-plasma interaction have been measured and analysed. The obtained results indicate an essential intensification of ignition and combustion processes in the microwave burner compared to those in conventional burners. In particular, it has been demonstrated that the microwave energy consumption is only about 10% of the required expenditure of oil or gas, measured in heat equivalent. A design of an industrial microwave-plasma burner is proposed. Prospects of such burner for applications at industrial boilers of power plants are discussed. 6 refs., 4 figs., 2 tabs.

  20. 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.  ……

  1. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

    State-of-the-art microwave systems always require higher performance and lower cost microwave components. Constantly growing demands and performance requirements of industrial and scientific applications often make employing traditionally designed components impractical. For that reason, the design...... and development process remains a great challenge today. This problem motivated intensive research efforts in microwave design and technology, which is responsible for a great number of recently appeared alternative approaches to analysis and design of microwave components and antennas. This book highlights...... techniques. Modelling and computations in electromagnetics is a quite fast-growing research area. The recent interest in this field is caused by the increased demand for designing complex microwave components, modeling electromagnetic materials, and rapid increase in computational power for calculation...

  2. 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...

  3. MEMS scanning micromirror for optical coherence tomography.

    Science.gov (United States)

    Strathman, Matthew; Liu, Yunbo; Keeler, Ethan G; Song, Mingli; Baran, Utku; Xi, Jiefeng; Sun, Ming-Ting; Wang, Ruikang; Li, Xingde; Lin, Lih Y

    2015-01-01

    This paper describes an endoscopic-inspired imaging system employing a micro-electromechanical system (MEMS) micromirror scanner to achieve beam scanning for optical coherence tomography (OCT) imaging. Miniaturization of a scanning mirror using MEMS technology can allow a fully functional imaging probe to be contained in a package sufficiently small for utilization in a working channel of a standard gastroesophageal endoscope. This work employs advanced image processing techniques to enhance the images acquired using the MEMS scanner to correct non-idealities in mirror performance. The experimental results demonstrate the effectiveness of the proposed technique.

  4. 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...

  5. Microwave oscillator with reduced phase noise by negative feedback incorporating microwave signals with suppressed carrier

    Science.gov (United States)

    Dick, G. J.; Saunders, J.

    1989-01-01

    Oscillator configurations which reduce the effect of 1/f noise sources for both direct feedback and stabilized local oscillator (STALO) circuits are developed and analyzed. By appropriate use of carrier suppression, a small signal is generated which suffers no loss of loop phase information or signal-to-noise ratio. This small signal can be amplified without degradation by multiplicative amplifier noise, and can be detected without saturation of the detector. Together with recent advances in microwave resonator Qs, these circuit improvements will make possible lower phase noise than can be presently achieved without the use of cryogenic devices.

  6. 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.

  7. 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

  8. Microwave Frequency Multiplier

    Science.gov (United States)

    Velazco, J. E.

    2017-02-01

    High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing

  9. Microwave impedance imaging on semiconductor memory devices

    Science.gov (United States)

    Kundhikanjana, Worasom; Lai, Keji; Yang, Yongliang; Kelly, Michael; Shen, Zhi-Xun

    2011-03-01

    Microwave impedance microscopy (MIM) maps out the real and imaginary components of the tip-sample impedance, from which the local conductivity and dielectric constant distribution can be derived. The stray field contribution is minimized in our shielded cantilever design, enabling quantitative analysis of nano-materials and device structures. We demonstrate here that the MIM can spatially resolve the conductivity variation in a dynamic random access memory (DRAM) sample. With DC or low-frequency AC bias applied to the tip, contrast between n-doped and p-doped regions in the dC/dV images is observed, and p-n junctions are highlighted in the dR/dV images. The results can be directly compared with data taken by scanning capacitance microscope (SCM), which uses unshielded cantilevers and resonant electronics, and the MIM reveals more information of the local dopant concentration than SCM.

  10. Restoration of multichannel microwave radiometric images

    Science.gov (United States)

    Chin, R. T.; Yeh, C.-L.; Olson, W. S.

    1985-01-01

    A constrained iterative image restoration method is applied to multichannel diffraction-limited imagery. This method is based on the Gerchberg-Papoulis algorithm utilizing incomplete information and partial constraints. The procedure is described using the orthogonal projection operators which project onto two prescribed subspaces iteratively. Its properties and limitations are presented. The effect of noise was investigated and a better understanding of the performance of the algorithm with noisy data has been achieved. The restoration scheme with the selection of appropriate constraints was applied to a practical problem. The 6.6, 10.7, 18, and 21 GHz satellite images obtained by the scanning multichannel microwave radiometer (SMMR), each having different spatial resolution, were restored to a common, high resolution (that of the 37 GHz channels) to demonstrate the effectiveness of the method. Both simulated data and real data were used in this study. The restored multichannel images may be utilized to retrieve rainfall distributions.

  11. Femtosecond scanning tunneling microscope

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, A.J.; Donati, G.P.; Rodriguez, G.; Gosnell, T.R.; Trugman, S.A.; Some, D.I.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). By combining scanning tunneling microscopy with ultrafast optical techniques we have developed a novel tool to probe phenomena on atomic time and length scales. We have built and characterized an ultrafast scanning tunneling microscope in terms of temporal resolution, sensitivity and dynamic range. Using a novel photoconductive low-temperature-grown GaAs tip, we have achieved a temporal resolution of 1.5 picoseconds and a spatial resolution of 10 nanometers. This scanning tunneling microscope has both cryogenic and ultra-high vacuum capabilities, enabling the study of a wide range of important scientific problems.

  12. 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.

  13. Adaptive Optical Scanning Holography

    Science.gov (United States)

    Tsang, P. W. M.; Poon, Ting-Chung; Liu, J.-P.

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  14. The Liverpool Microwave Palaeointensity System

    Science.gov (United States)

    Hill, Mimi; Biggin, Andrew; Hawkins, Louise; Hodgson, Emma; Hurst, Elliot

    2016-04-01

    The motivation for the group at Liverpool in the 1990s (led by John Shaw and Derek Walton) to start experimenting with using microwaves to demagnetise and remagnetise palaeomagnetic samples, rather than heating using conventional ovens, was to reduce laboratory induced alteration in absolute palaeointensity experiments. As with other methods, the non-ideal effects of grain size and naturally altered remanence must still be addressed. From humble beginnings using a domestic microwave oven the current 4th generation microwave system (MWS) has developed in to an integrated combined 14 GHz microwave resonant cavity and SQUID magnetometer system. The MWS is designed to investigate one 5 mm diameter sample at a time with microwave exposure (the equivalent of a heating step in conventional experiments) ranging from a few seconds up to around a minute. Each experiment (protocol, checks, direction and strength of applied field, number of steps etc) can be tailored to the behaviour of each individual sample. There have been many published studies demonstrating the equivalence of conventional thermal (Thellier) and microwave techniques using both artificial and natural remanence and also that the microwave method can indeed reduce laboratory induced alteration. Here an overview of the present MWS including a discussion of the physical processes occurring will be given. Examples of current projects (both archaeological and geological) utilising the method will also be described. Finally, future developments and applications of the method will be discussed.

  15. A novel STM-assisted microwave microscope with capacitance and loss imaging capability.

    Science.gov (United States)

    Imtiaz, Atif; Anlage, Steven M

    2003-04-01

    We report a new technique of scanning capacitance microscopy at microwave frequencies. A near field scanning microwave microscope probe is kept at a constant height of about 1 nm above the sample with the help of scanning tunneling microscope (STM) feedback. The microwaves are incident onto the sample through a coaxial resonator that is terminated at one end with a sharp tip (the same tip is used to conduct STM), and capacitively coupled to a feedback circuit and microwave source at the other end. The feedback circuit keeps the source locked onto the resonance frequency of the resonator and outputs the frequency shift and quality factor change due to property variations of the sample. The spatial resolution due to capacitance variations is congruent with 2.5 nm. The microwave microscope is sensitive to sample sheet resistance, as demonstrated through measurements on a doped silicon sample. We develop a quantitative transmission line model treating the tip to sample interaction as a series combination of capacitance and sheet resistance in the sample.

  16. Microwave radiometry and applications

    Science.gov (United States)

    Polívka, Jiří

    1995-09-01

    The radiometry in general is a method of detecting the radiation of matter. All material bodies and substances radiate energy in the form of electromagnetic waves according to Planck s Law. The frequency spectrum of such thermal radiation is determined, beyond the properties of a blackbody, by the emissivity of surfaces and by the temperature of a particular body. Also, its reflectivity and dispersion take part. Investigating the intensity of radiation and its spectral distribution, one may determine the temperature and characterize the radiating body as well as the ambient medium, all independently of distance. With the above possibilities, the radiometry represents a base of scientific method called remote sensing. Utilizing various models, temperature of distant bodies and images of observed scenes can be determined from the spatial distribution of radiation. In this method, two parameters are of paramount importance: the temperature resolution, which flows out from the detected energy, and the spatial resolution (or, angular resolution), which depends upon antenna size with respect to wavelength. An instrument usable to conduct radiometric observations thus consists of two basic elements: a detector or radiometer, which determines the temperature resolution, and an antenna which determines the angular or spatial resolution. For example, a photographic camera consists of an objective lens (antenna) and of a sensitive element (a film or a CCD). In remote sensing, different lenses and reflectors and different sensors are employed, both adjusted to a particular spectrum region in which certain important features of observed bodies and scenes are present: frequently, UV and IR bands are used. The microwave radiometry utilizes various types of antennas and detectors and provides some advantages in observing various scenes: the temperature resolution is recently being given in milikelvins, while the range extends from zero to millions of Kelvins. Microwaves also offer

  17. Cutting Last Wires for Mobile Communications by Microwave Power Transfer

    OpenAIRE

    Huang, Kaibin; Zhou, Xiangyun

    2014-01-01

    The advancements in microwave power transfer (MPT) over past decades have enabled wireless power transfer over long distances. The latest breakthroughs in wireless communication, namely massive MIMO, small cells and millimeter-wave communication, make wireless networks suitable platforms for implementing MPT. This can lead to the elimination of the "last wires" connecting mobile devices to the grid for recharging, thereby tackling a long-standing ICT grand challenge. Furthermore, the seamless...

  18. Aerodigestive tract burn from ingestion of microwaved food.

    Science.gov (United States)

    Silberman, Michael; Jeanmonod, Rebecca

    2013-01-01

    Aerodigestive tract burns represent a rare but potentially devastating injury pattern throughout the world. Although the majority of these injuries do not require intervention, these burns have the potential for poor outcomes. Traditionally this disease has been caused by superheated gases found in explosions or fire-related injury. However, as technology advances, it brings novel methods for injury that require physician awareness of potential hazards. We describe a case of laryngeal and esophageal thermal burn caused by a microwave heated food bolus.

  19. 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.

  20. Microwave Plasma Synthesis of Nanopowders

    Institute of Scientific and Technical Information of China (English)

    Joseph; Lik; Hang; Chau

    2007-01-01

    1 Results and Discussion Nanopowders were synthesized by using microwave plasma synthesis technique.The microwave plasma was operated in atmospheric pressure at a frequency of 2.45 GHz.The reaction temperature is directly related to the power of the microwave generator that can be controlled by adjusting the actual operating current.Firstly,ionization and dissociation of precursor species will be occurred in the plasma,nucleus can then be formed by the collision of these molecules,followed by the growth...

  1. 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...... frequencies the atmosphere is virtually transparent even with clouds which make microwave radiometry very valuable in regions with frequent cloud cover such as the temperate and arctic zones. At high frequencies, however, atmospheric absorption will degrade measurements of earth surfaces but this phenomenon...

  2. 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.

  3. Effects of ultrasonic and microwave pretreatments on lipid extraction of microalgae.

    Science.gov (United States)

    Ma, Yu-An; Cheng, Yi-Ming; Huang, Jenn-Wen; Jen, Jen-Fon; Huang, Yung-Sheng; Yu, Chung-Chyi

    2014-08-01

    The extraction of lipids from microalgal cells using ultrasonic and microwave pretreatments is mechanistically evaluated based on the distribution of cell fragments, the lipid content analysis, the scanning electron microscopic (SEM) observation of ruptured microalgal cells, and the analysis of fatty acids. The results indicate that microwave pretreatment extracts lipids more rapidly and efficiently as compared to ultrasonic pretreatment. The rupture of cells in the microwave process is due to the tremendous pressure caused by the rapid heating of the moisture inside the microalgal cells, whereas in the ultrasonic process the microalgal cells are ruptured by shock waves from cavitation bubbles outside the cells. The fatty acid composition of the respective lipids extracted via the two types of pretreatment did not vary significantly from one another. These results demonstrate that the microwave process is rapid and more effective than the ultrasonic process for lipid extraction from microalgae.

  4. Applications. SCANS Plans Portfolio.

    Science.gov (United States)

    Sample, Barbara

    This guide assists English-as-a-Second-Language educators in helping students fill out simple application forms. The guide discusses performance outcomes, communications teaching points, SCANS (Secretary's Committee on Achieving Necessary Skills) competencies, classroom configurations, materials, and procedures. Blank forms, suitable for…

  5. Sinus MRI scan

    Science.gov (United States)

    ... A CT scan may be preferred in emergency cases, since it is faster and often available in the emergency room. Note: MRI is not as effective as CT in defining the anatomy of the sinuses, and therefore is not typically used for suspected acute sinusitis.

  6. 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.

  7. SCANNING-DLTS

    OpenAIRE

    Breitenstein, O.

    1989-01-01

    Scanning Deep Level Transient Spectroscopy (SDLTS) is a current SEM technique for the detection of the local distribution of deep level centres in semiconductors. The contribution deals with the physical foundations of the SDLTS technique and it discusses the demands on the instrumentation. The measurement practice is described and illustrated by several experimental examples. Finally, the possibilities and limitations of SDLTS are critically reviewed.

  8. Microwave assisted synthesis and optimization of Aegle marmelos-g-poly(acrylamide): release kinetics studies.

    Science.gov (United States)

    Setia, A; Kumar, R

    2014-04-01

    Microwave assisted grafting of poly(acrylamide) on to Aegle marmelos gum was carried out employing 3-factor 3-level full factorial design. Microwave power, microwave exposure time and concentration of gum were selected as independent variable and grafting efficiency was taken as dependent variable. A. marmelos-g-poly(acrylamide) was characterized by FTIR, DSC, X-ray diffraction and scanning electron microscopy. Microwave power, microwave exposure time had synergistic effect on grafting efficiency where as concentration of the gum did not contributed much to grafting efficiency. Batch having microwave power - 80%, microwave exposure time -120 s and concentration of A. marmelos gum - 2% was selected as the optimized formulation. Comparative release behaviour of diclofenac sodium from the matrix tablets of A. marmelos gum and A. marmelos-g-polyacrylamide was evaluated. The results of kinetic studies revealed that the graft copolymer matrix, marketed tablets and polymer matrix tablets of A. marmelos gum released the drug by zero order kinetics and with n value greater than 1, indicating that the mechanism for release as super case II transport i.e. dominated by the erosion and swelling of the polymer.

  9. Three-Dimensional Near-Field Microwave Holography for Tissue Imaging

    OpenAIRE

    Amineh, Reza K.; Khalatpour, Ali; Xu, Haohan; Baskharoun, Yona; Nikolova, Natalia K.

    2012-01-01

    This paper reports the progress toward a fast and reliable microwave imaging setup for tissue imaging exploiting near-field holographic reconstruction. The setup consists of two wideband TEM horn antennas aligned along each other’s boresight and performing a rectangular aperture raster scan. The tissue sensing is performed without coupling liquids. At each scanning position, wideband data is acquired. Then, novel holographic imaging algorithms are implemented to provide three-dimensional imag...

  10. Microwave Magnetoelectric Devices

    Directory of Open Access Journals (Sweden)

    A. S. Tatarenko

    2012-01-01

    Full Text Available 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 frequency 7360 MHz was obtained. A maximum phase shift of 30–40 degree at the frequency region 6–9 GHz was obtained.

  11. Cryogenic coaxial microwave filters

    CERN Document Server

    Tancredi, G; Meeson, P J

    2014-01-01

    At millikelvin temperatures the careful filtering of electromagnetic radiation, especially in the microwave regime, is critical for controlling the electromagnetic environment for experiments in fields such as solid-state quantum information processing and quantum metrology. We present a design for a filter consisting of small diameter dissipative coaxial cables that is straightforward to construct and provides a quantitatively predictable attenuation spectrum. We describe the fabrication process and demonstrate that the performance of the filters is in good agreement with theoretical modelling. We further perform an indicative test of the performance of the filters by making current-voltage measurements of small, underdamped Josephson Junctions at 15 mK and we present the results.

  12. Cosmic microwave background theory.

    Science.gov (United States)

    Bond, J R

    1998-01-01

    A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in -space are consistent with a DeltaT flat in frequency and broadly follow inflation-based expectations. That the levels are approximately (10(-5))2 provides strong support for the gravitational instability theory, while the Far Infrared Absolute Spectrophotometer (FIRAS) constraints on energy injection rule out cosmic explosions as a dominant source of LSS. Band-powers at 100 suggest that the universe could not have re-ionized too early. To get the LSS of Cosmic Background Explorer (COBE)-normalized fluctuations right provides encouraging support that the initial fluctuation spectrum was not far off the scale invariant form that inflation models prefer: e.g., for tilted Lambda cold dark matter sequences of fixed 13-Gyr age (with the Hubble constant H0 marginalized), ns = 1.17 +/- 0.3 for Differential Microwave Radiometer (DMR) only; 1.15 +/- 0.08 for DMR plus the SK95 experiment; 1.00 +/- 0.04 for DMR plus all smaller angle experiments; 1.00 +/- 0.05 when LSS constraints are included as well. The CMB alone currently gives weak constraints on Lambda and moderate constraints on Omegatot, but theoretical forecasts of future long duration balloon and satellite experiments are shown which predict percent-level accuracy among a large fraction of the 10+ parameters characterizing the cosmic structure formation theory, at least if it is an inflation variant.

  13. Fast microwave assisted pyrolysis of biomass using microwave absorbent.

    Science.gov (United States)

    Borges, Fernanda Cabral; Du, Zhenyi; Xie, Qinglong; Trierweiler, Jorge Otávio; Cheng, Yanling; Wan, Yiqin; Liu, Yuhuan; Zhu, Rongbi; Lin, Xiangyang; Chen, Paul; Ruan, Roger

    2014-03-01

    A novel concept of fast microwave assisted pyrolysis (fMAP) in the presence of microwave absorbents was presented and examined. Wood sawdust and corn stover were pyrolyzed by means of microwave heating and silicon carbide (SiC) as microwave absorbent. The bio-oil was characterized, and the effects of temperature, feedstock loading, particle sizes, and vacuum degree were analyzed. For wood sawdust, a temperature of 480°C, 50 grit SiC, with 2g/min of biomass feeding, were the optimal conditions, with a maximum bio-oil yield of 65 wt.%. For corn stover, temperatures ranging from 490°C to 560°C, biomass particle sizes from 0.9mm to 1.9mm, and vacuum degree lower than 100mmHg obtained a maximum bio-oil yield of 64 wt.%. This study shows that the use of microwave absorbents for fMAP is feasible and a promising technology to improve the practical values and commercial application outlook of microwave based pyrolysis.

  14. 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.

  15. 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

  16. Understanding microwave vessel contamination by chloride species.

    Science.gov (United States)

    Recchia, Sandro; Spanu, Davide; Bianchi, Davide; Dossi, Carlo; Pozzi, Andrea; Monticelli, Damiano

    2016-10-01

    Microwaves are widely used to assist digestion, general sample treatment and synthesis. The use of aqua regia is extensively adopted for the closed vessel mineralization of samples prior to trace element detection, leading to the contamination of microwave vessels by chlorine containing species. The latter are entrapped in the polymeric matrix of the vessels, leading to memory effects that are difficult to remove, among which the risk of silver incomplete recoveries by removal of the sparingly soluble chloride is the predominant one. In the present paper, we determined by mass spectrometry that hydrogen chloride is the species entrapped in the polymeric matrix and responsible for vessel contamination. Moreover, several decontamination treatments were considered to assess their efficiency, demonstrating that several cleaning cycles with water, nitric acid or silver nitrate in nitric acid were inefficient in removing chloride contamination (contamination reduction around 90%). Better results (≈95% decrease) were achieved by a single decontamination step in alkaline environment (sodium hydroxide or ammonia). Finally, a thermal treatment in a common laboratory oven (i.e. without vacuum and ventilation) was tested: a one hour heating at 150°C leads to a 98.5% decontamination, a figure higher than the ones obtained by wet treatments which requires comparable time. The latter treatment is a major advancement with respect to existing treatments as it avoids the need of a vacuum oven for at least 17h as presently proposed in the literature.

  17. Ordered mesoporous silica: microwave synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Fantini, M.C.A. [IF-USP, CP 66318, 05315-970, Sao Paulo, SP (Brazil)]. E-mail: mfantini@if.usp.br; Matos, J.R. [IQ-USP, CP 26077, 05599-970, Sao Paulo, SP (Brazil); Silva, L.C. Cides da [IQ-USP, CP 26077, 05599-970, Sao Paulo, SP (Brazil); Mercuri, L.P. [IQSC-USP, CP 780, 13560-970, Sao Carlos, SP (Brazil); Chiereci, G.O. [IQSC-USP, CP 780, 13560-970, Sao Carlos, SP (Brazil); Celer, E.B. [Department of Chemistry, Kent State University, Kent, OH 44240 (United States); Jaroniec, M. [Department of Chemistry, Kent State University, Kent, OH 44240 (United States)

    2004-09-25

    Ordered mesoporous silicas, FDU-1, synthesized by using triblock copolymer, EO{sub 39}BO{sub 47}EO{sub 39}, as template were hydrothermally treated in a microwave oven at 373 K for different periods of time. The structural and morphological properties of these silicas were investigated by X-ray diffraction and nitrogen adsorption and compared with those for the FDU-1 samples prepared by conventional hydrothermal treatment at 373 K. All samples were calcined at 813 K in N{sub 2} and air. This procedure succeeded in producing ordered cage-like mesoporous structures even after 15 min of the microwave treatment. The best sample was obtained after 60 min of the microwave treatment, which is reflected by narrow pore size distribution, uniform pore size entrances and thick mesopore walls. Longer time of the microwave treatment increased nonuniformity of the pore entrance sizes as evidenced by changes in the hysteresis loops of nitrogen adsorption isotherms.

  18. Microwave transistor oscillator frequency tripling

    OpenAIRE

    B. A. Kotserzhynskyi

    2010-01-01

    The frequency tripler state of the art is consided. The oscillator-frequency tripler design is now at the state of scientific research. Microwave companies release the devices of the such structure: oscillator, buffer, amplifier-tripler.

  19. Microwave transistor oscillator frequency tripling

    Directory of Open Access Journals (Sweden)

    B. A. Kotserzhynskyi

    2010-01-01

    Full Text Available The frequency tripler state of the art is consided. The oscillator-frequency tripler design is now at the state of scientific research. Microwave companies release the devices of the such structure: oscillator, buffer, amplifier-tripler.

  20. Develop Prototype Microwave Interferometry Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Tringe, J. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Converse, M. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kane, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-11-15

    A prototype microwave interferometer was created at NSTec to characterize moving conductive fronts in upcoming experiments. The interferometer is capable of operation in the ~26-40 GHz band, and interrogating fronts with more than 1 W of power.

  1. 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.

  2. Validation of burst overlapping for ALOS-2 PALSAR-2 ScanSAR-ScanSAR interferometry

    Science.gov (United States)

    Natsuaki, Ryo; Motohka, Takeshi; Ohki, Masato; Watanabe, Manabu; Suzuki, Shinichi

    2016-10-01

    The Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the Advanced Land Observing Satellite- 2 (ALOS-2, "DAICHI-2") is the latest L-band spaceborne synthetic aperture radar (SAR). PALSAR-2 observes the world mainly with 10 m resolution / 70 km swath Stripmap mode and 25 m resolution / 350 km swath ScanSAR mode. The 3-m resolution Stripmap mode is mainly used upon Japan. 350 km ScanSAR observation could detect large scale deformation e.g., the Mw 7.8 Gorkha, Nepal earthquake and its aftershocks in 2015. ALOS-2 ScanSAR is the first one that supports ScanSAR-ScanSAR interferometry in L-band spaceborne SAR. However, because of the parameter setting error for the orbit estimation, ALOS-2 PALSAR-2 ScanSAR could achieve little number of interferometric pair until the software modification on February 8, 2015. That is, the burst overlap timing required for the interferometric analysis was insufficient and it depends on the observation date. In this paper, we report the investigation results of this case and discuss the current status of the ALOS-2 ScanSAR InSAR. Some archives achieved before February 8, 2015 can be used for interferometric analysis with after Feb. 8. However, most of them have no interferometric pair. We also report that the archives acquired after February 8, have enough burst overlapping.

  3. 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.

  4. Controlled Microwave Heating Accelerates Rolling Circle Amplification.

    Science.gov (United States)

    Yoshimura, Takeo; Suzuki, Takamasa; Mineki, Shigeru; Ohuchi, Shokichi

    2015-01-01

    Rolling circle amplification (RCA) generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same.

  5. 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

  6. Evaluation of microwaves soil moisture products based on two years of ground measurements over a Sahelian region.

    Science.gov (United States)

    Gruhier, C.; de Rosnay, P.; Kerr, Y.; Kergoat, L.

    2008-12-01

    Microwaves remote sensing is a promising approach to measure soil moisture values and variations. Soil moisture is a very important variable which strongly interacts with soil-vegetation-atmosphere fluxes. This is particularly true in Sahelian region with monsoon climatic system. From active or passive microwaves measurements of backscatter coefficients or brightness temperatures, soil moisture products are derived. Soil moisture products evaluation is essential to improve algorithm and inform users on the products quality (eg quality of soil moisture products variability or absolutes). This study aims to evaluate and to intercompare five soil moisture products from active and passive microwaves sensors. The study is performed for 2005-2006, for a 1 x 3 degrees longitude-latitude window located in Sahel (14-17N and 0-1W). In addition an accurate validation is conducted for specific locations based on ground measurements available in this region. It uses the Gourma (Mali) soil moisture measurements network installed in the framework of the African Monsoon Multidisciplinary Analysis (AMMA) program. The soil moisture network has been organized in order to validate remotely sensed soil moisture for the future Soil Moisture an Ocean Salinity (SMOS) mission. Three stations located on sandy dune systems have been selected according to their location along the North-South climatic gradient. They provide continuous soil moisture measurements at 15-minute time step and at 5-cm depth for 2005-2006. Five soil moisture products provided by three different sensors are considered. 1) From the Advanced Microwave Scanning Radiometer on Earth Observing System (AMSR-E), two soil moisture products are used: the National Snow and Ice Data Center product and the Amsterdam University product. 2) From the Wind Scatterometer, on European Remote Sensing (ERS) satellite, two soil moisture products are evaluated: the Vienna University of Technology and the Zribi et al 2007 products. 3) The

  7. Scanning Quantum Decoherence Microscopy

    OpenAIRE

    2008-01-01

    The use of qubits as sensitive magnetometers has been studied theoretically and recent demonstrated experimentally. In this paper we propose a generalisation of this concept, where a scanning two-state quantum system is used to probe the subtle effects of decoherence (as well as its surrounding electromagnetic environment). Mapping both the Hamiltonian and decoherence properties of a qubit simultaneously, provides a unique image of the magnetic (or electric) field properties at the nanoscale....

  8. 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.

  9. Mass Production of Carbon Nanofibers Using Microwave Technology.

    Science.gov (United States)

    Mubarak, N M; Abdullah, E C; Sahu, J N; Jayakumar, N S; Ganesan, P

    2015-12-01

    Carbon nanotubes (CNFs) were produced by gas phase single stage microwave assisted chemical vapour deposition (MA-CVD) using ferrocene as a catalyst and acetylene (C2H2) and hydrogen (H2) as precursor gases. The effect of the process parameters such as microwave power, radiation time, and gas ratio of C2H2/H2 was investigated. The CNFs were characterized using scanning and transmission electron microscopy (TEM), and by thermogravimetric analysis (TGA). Results reveal that the optimized conditions for CNF production were 1000 W reaction power, 35 min radiation time, and 0.8 gas ratio of C2H2/H2. TEM analyses revealed that the uniformly dispersed CNFs diameters ranging from 115-131 nm. The TGA analysis showed that the purity of CNF produced was 93%.

  10. Nonlinear Effects in the Cosmic Microwave Background

    CERN Document Server

    Maartens, R

    2000-01-01

    Major advances in the observation and theory of cosmic microwave background anisotropies have opened up a new era in cosmology. This has encouraged the hope that the fundamental parameters of cosmology will be determined to high accuracy in the near future. However, this optimism should not obscure the ongoing need for theoretical developments that go beyond the highly successful but simplified standard model. Such developments include improvements in observational modelling (e.g. foregrounds, non-Gaussian features), extensions and alternatives to the simplest inflationary paradigm (e.g. non-adiabatic effects, defects), and investigation of nonlinear effects. In addition to well known nonlinear effects such as the Rees-Sciama and Ostriker-Vishniac effects, further nonlinear effects have recently been identified. These include a Rees-Sciama-type tensor effect, time-delay effects of scalar and tensor lensing, nonlinear Thomson scattering effects and a nonlinear shear effect. Some of the nonlinear effects and th...

  11. Cosmological Constraints from the Cosmic Microwave Background

    CERN Document Server

    Le Dour, M D M; Bartlett, J G; Blanchard, A

    2000-01-01

    Using an approximate likelihood method adapted to band-power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six-dimensional parameter space describing Inflation-generated adiabatic, scalar fluctuations. The basic preferences of simple Inflation scenarios are consistent with the data set: flat geometries $(\\OmT \\equiv 1-\\Omk \\sim 1)$ and a scale-invariant primeval spectrum ($n\\sim 1$) are favored. Models with significant negative curvature ($\\OmT < 0.7$) are eliminated, while constraints on postive curvature are less stringent. Degeneracies among the parameters prevent independent determinations of the matter density $\\OmM$ and the cosmological constant $\\Lambda$, and the Hubble constant $\\Ho$ remains relatively unconstrained. We also find that the relative height of the first Doppler peak suggests a high baryon content ($\\Omb h^2$), almost independently of the other parameters; besides the overall qualitative advance ex...

  12. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  13. Scanning ultrafast electron microscopy.

    Science.gov (United States)

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

    2010-08-24

    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 which the pulse contains at most one or a few electrons, thus achieving imaging without the space-charge effect between electrons, and still in ten(s) of seconds. For imaging, the secondary electrons from surface structures are detected, as demonstrated here for material surfaces and biological specimens. By recording backscattered electrons, diffraction patterns from single crystals were also obtained. Scanning pulsed-electron microscopy with the acquired spatiotemporal resolutions, and its efficient heat-dissipation feature, is now poised to provide in situ 4D imaging and with environmental capability.

  14. Microwaves Sensor for Wind Turbine Blade Inspection

    Science.gov (United States)

    Li, Zhen; Haigh, Arthur; Soutis, Constantinos; Gibson, Andrew; Sloan, Robin

    2017-04-01

    The structural integrity of wind turbine blades can be adversely affected by their structural dynamics, temperature extremes, lightning strikes, ultraviolet radiation from sunlight and airborne particulate matter such as hailstones and sand. If subsurface delamination occurs and is undetected then this can lead to fibre breakage and catastrophic failures in composite blades. In this paper we introduce a microwave scanning technique that detects such delamination in practical blade assemblies. Using an open-ended waveguide sensor, the electromagnetic signal reflected from the composite is found to have a phase profile that can detect changes in the composite cross section. Glass fibre T-joints are scanned and the results used to detect thickness variations (e.g., the presence of the web) and delamination. Results are compared across the 18-20 GHz frequency band. The dielectric permittivity of the composite system is measured and is used to estimate the stand-off distance and operating frequency of the sensor. This is critical to the system's ability to detect damage. When the sensor is close to the surface of the structure (standoff distance ≈ 5 mm), delamination down to 0.2 mm in width could be detected.

  15. 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

  16. 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}.

  17. Optimal scan strategies for future CMB satellite experiments

    Science.gov (United States)

    Wallis, Christopher G. R.; Brown, Michael L.; Battye, Richard A.; Delabrouille, Jacques

    2017-04-01

    The B-mode polarization 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 polarization 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 polarization 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 proposed for the European Space Agency M5 call, considering the practical considerations of fuel requirement, data rate and the relative orientation of the telescope to the earth. Having chosen a scan strategy we then go on to investigate the suitability of the scan strategy.

  18. 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

  19. Characteristics of Cylindrical Microwave Plasma Source at Low Pressure

    Science.gov (United States)

    Park, Seungil; Youn, S.; Kim, S. B.; Yoo, S. J.

    2016-10-01

    A microwave plasma source with a cylindrical resonance cavity has been proposed to generate the plasma at low pressure. This plasma source consists of magnetron, waveguide, antenna, and cavity. The microwave generating device is a commercial magnetron with 1 kW output power at the frequency of 2.45 GHz. The microwave is transmitted through the rectangular waveguide with the whistle shape, and coupled to the cavity by the slot antenna. The resonant mode of the cylindrical cavity is the TE111 mode. The operating pressure is between 0.1 Torr and 0.3 Torr with the Argon and nitrogen gas. The electron temperature and electron number density of argon plasma were measured with the optical emission spectroscopy measurement. And Ar1s5 metastable density was measured using tunable diode laser absorption spectroscopy (TDLAS). The plasma diagnostic results of a cylindrical microwave plasma source would be described in this study. This work was supported by R&D Program of ``Plasma Advanced Technology for Agriculture and Food (Plasma Farming)'' through the National Fusion Research Institute of Korea (NFRI) funded by the Government funds.

  20. 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.

  1. Microwave-assisted reactions in heterocyclic compounds with applications in medicinal and supramolecular chemistry.

    Science.gov (United States)

    de la Hoz, Antonio; Díaz-Ortiz, Angel; Moreno, Andrés; Sanchéz-Migallón, Ana; Prieto, Pilar; Carrillo, José Ramón; Vázquez, Ester; Gómez, M Victoria; Herrero, M Antonia

    2007-12-01

    Microwave irradiation has been successfully applied in organic chemistry. Spectacular accelerations, higher yields under milder reaction conditions and higher product purities have all been reported. Indeed, a number of authors have described success in reactions that do not occur under conventional heating and modifications in selectivity (chemo-, regio- and stereoselectivity) have even been reported. Recent advances in microwave-assisted combinatorial chemistry include high-speed solid-phase and polymer-supported organic synthesis, rapid parallel synthesis of compound libraries, and library generation by automated sequential microwave irradiation. In addition, new instrumentation for high-throughput microwave-assisted synthesis continues to be developed at a steady pace. The impressive speed combined with the unmatched control over reaction parameters justifies the growing interest in this application of microwave heating. In this review we highlight our recent advances in this area, with a particular emphasis on cycloaddition reactions of heterocyclic compounds both with and without supports, applications in supramolecular chemistry and the reproducibility and scalability of organic reactions involving the use of microwave irradiation techniques.

  2. Cardiac tissue ablation with catheter-based microwave heating.

    Science.gov (United States)

    Rappaport, C

    2004-11-01

    The common condition of atrial fibrillation is often treated by cutting diseased cardiac tissue to disrupt abnormal electrical conduction pathways. Heating abnormal tissue with electromagnetic power provides a minimally invasive surgical alternative to treat these cardiac arrhythmias. Radio frequency ablation has become the method of choice of many physicians. Recently, microwave power has also been shown to have great therapeutic benefit in medical treatment requiring precise heating of biological tissue. Since microwave power tends to be deposited throughout the volume of biological media, microwave heating offers advantages over other heating modalities that tend to heat primarily the contacting surface. It is also possible to heat a deeper volume of tissue with more precise control using microwaves than with purely thermal conduction or RF electrode heating. Microwave Cardiac Ablation (MCA) is used to treat heart tissue that allows abnormal electrical conduction by heating it to the point of inactivation. Microwave antennas that fit within catheter systems can be positioned close to diseased tissue. Specialized antenna designs that unfurl from the catheter within the heart can then radiate specifically shaped fields, which overcome problems such as excessive surface heating at the contact point. The state of the art in MCA is reviewed in this paper and a novel catheter-based unfurling wide aperture antenna is described. This antenna consists of the centre conductor of a coaxial line, shaped into a spiral and insulated from blood and tissue by a non-conductive fluid filled balloon. Initially stretched straight inside a catheter for transluminal guiding, once in place at the cardiac target, the coiled spiral antenna is advanced into the inflated balloon. Power is applied in the range of 50-150 W at the reserved industrial, scientific and medical (ISM) frequency of 915 MHz for 30-90 s to create an irreversible lesion. The antenna is then retracted back into the

  3. 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.

  4. 空间点云物体理解与识别的研究进展%Advances in understanding and recognition of spatial obj ects from scanned data

    Institute of Scientific and Technical Information of China (English)

    宁小娟; 王映辉; 郝雯

    2014-01-01

    Understanding and recognition of spatial obj ects are the important research in computer vision and computer graphics which can be widely used in robot perception navigation,personal safety and environment monitoring,etc.Based on different shape complexity of spatial obj ects in point clouds,this paper mainly discusses the spatial obj ects from simple scenario (single target obj ect)to complex scenes (multi-target scenarios).Taking the segmentation,understanding and recognition as mainlines,the paper summarizes the recent work and advances in understanding and recognition of the spatial obj ects in point clouds respectively.Also,it points out the critical issues including pose,topology and semantics encountered in the understanding and recognition of spatial obj ects via the discussion and analysis of the existing advantages and disadvantages,and suggests the corresponding solving-thinking ways and research priority for the future work.%空间物体的理解与识别是计算机视觉与计算机图形领域的重要研究课题,广泛应用于机器人感知导航、人身安全和环境监控等方面。以点云为物体的数据表示形式,依据空间物体的形状复杂度不同,从简单场景(单目标物体)、复杂场景(多目标场景)两个方面来重点探讨,以分割、理解及识别为主线分别针对空间点云物体的理解与识别的研究现状和进展进行了归纳和总结,并通过分类讨论和剖析现有方法的优缺点,指出空间物体理解与识别方面所遇到的姿态、拓扑关联及语义等关键性问题,并提出相应的解决思路和下一步的研究重点。

  5. Using a Support Vector Machine and a Land Surface Model to Estimate Large-Scale Passive Microwave Temperatures over Snow-Covered Land in North America

    Science.gov (United States)

    Forman, Barton A.; Reichle, Rolf Helmut

    2014-01-01

    A support vector machine (SVM), a machine learning technique developed from statistical learning theory, is employed for the purpose of estimating passive microwave (PMW) brightness temperatures over snow-covered land in North America as observed by the Advanced Microwave Scanning Radiometer (AMSR-E) satellite sensor. The capability of the trained SVM is compared relative to the artificial neural network (ANN) estimates originally presented in [14]. The results suggest the SVM outperforms the ANN at 10.65 GHz, 18.7 GHz, and 36.5 GHz for both vertically and horizontally-polarized PMW radiation. When compared against daily AMSR-E measurements not used during the training procedure and subsequently averaged across the North American domain over the 9-year study period, the root mean squared error in the SVM output is 8 K or less while the anomaly correlation coefficient is 0.7 or greater. When compared relative to the results from the ANN at any of the six frequency and polarization combinations tested, the root mean squared error was reduced by more than 18 percent while the anomaly correlation coefficient was increased by more than 52 percent. Further, the temporal and spatial variability in the modeled brightness temperatures via the SVM more closely agrees with that found in the original AMSR-E measurements. These findings suggest the SVM is a superior alternative to the ANN for eventual use as a measurement operator within a data assimilation framework.

  6. Microwave. Instructor's Edition. Louisiana Vocational-Technical Education.

    Science.gov (United States)

    Blanton, William

    This publication contains related study assignments and job sheets for a course in microwave technology. The course is organized into 12 units covering the following topics: introduction to microwave, microwave systems, microwave oscillators, microwave modulators, microwave transmission lines, transmission lines, detectors and mixers, microwave…

  7. Surface micromachined scanning mirrors

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    1992-01-01

    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....... Torsional mirrors showed resonance frequencies in the range of 410 kHz - 667 kHz with Q values of 10 - 17. All measurements performed at atmospheric pressure. Both types of mechanical structures were deflected electrostatically at large angles (± 5°) more than 1011 times without breaking and without any...

  8. Enhancement of solubility and dissolution rate of poorly water soluble raloxifene using microwave induced fusion method

    Directory of Open Access Journals (Sweden)

    Payal Hasmukhlal Patil

    2013-09-01

    Full Text Available The objective of the present work was to enhance the solubility and dissolution rate of the drug raloxifene HCl (RLX, which is poorly soluble in water. The solubility of RLX was observed to increase with increasing concentration of hydroxypropyl methylcellulose (HPMC E5 LV. The optimized ratio for preparing a solid dispersion (SD of RLX with HPMC E5 LV using the microwave-induced fusion method was 1:5 w/w. Microwave energy was used to prepare SDs. HPMC E5 LV was used as a hydrophilic carrier to enhance the solubility and dissolution rate of RLX. After microwave treatment, the drug and hydrophilic polymer are fused together, and the drug is converted from the crystalline form into an amorphous form. This was confirmed through scanning electron microscopy (SEM, differential scanning calorimetry (DSC and powder X-ray diffraction (PXRD studies. These results suggested that the microwave method is a simple and efficient method of preparing SDs. The solubility and dissolution rate of the SDs were increased significantly compared with pure RLX due to the surfactant and wetting properties of HPMC E5 LV and the formation of molecular dispersions of the drug in HPMC E5 LV. It was concluded that the solubility and dissolution rate of RLX are increased significantly when an SD of the drug is prepared using the microwave-induced fusion method.

  9. Student Microwave Experiments Involving the Doppler Effect.

    Science.gov (United States)

    Weber, F. Neff; And Others

    1980-01-01

    Described is the use of the Doppler Effect with microwaves in the measurement of the acceleration due to gravity of falling objects. The experiments described add to the repertoire of quantitative student microwave experiments. (Author/DS)

  10. Microwave Plasma System: PVA Tepla 300

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: Microwave AsherA tool using microwave oxygen plasma to remove organics on the surfacesSpecifications / Capabilities:Frequency: 2.45 GHzPower:...

  11. Microwave Radiometer for Aviation Safety Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SBIR Phase I Project proposes a new passive microwave airborne sensor for in flight icing hazard detection, Microwave Radiometer for Aviation Safety. A feasibility...

  12. DMSP SSM/I- Microwave Imager

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SSM/I is a seven-channel, four frequency, linearly-polarized, passive microwave radiometric system which measures atmospheric, ocean and terrain microwave...

  13. Ultrafast scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  14. Cosmic Microwave Background Data Analysis

    Science.gov (United States)

    Paykari, Paniez; Starck, Jean-Luc Starck

    2012-03-01

    that the highest power fluctuations occur at scales of about one degree. A number of ground-based interferometers provided measurements of the fluctuations with higher accuracy over the next three years, including the Very Small Array [16], Degree Angular Scale Interferometer (DASI) [61], and the Cosmic Background Imager (CBI) [78]. DASI was the first to detect the polarization of the CMB and the CBI provided the first E-mode polarization spectrum with compelling evidence that it is out of phase with the T-mode spectrum. In June 2001, NASA launched its second CMB mission (after COBE), Wilkinson Microwave Anisotropy Explorer (WMAP) [44], to make much more precise measurements of the CMB sky. WMAP measured the differences in the CMB temperature across the sky creating a full-sky map of the CMB in five different frequency bands. The mission also measured the CMB's E-mode and the foreground polarization. As of October 2010, the WMAP spacecraft has ended its mission after nine years of operation. Although WMAP provided very accurate measurements of the large angular-scale fluctuations in the CMB, it did not have the angular resolution to cover the smaller-scale fluctuations that had been observed by previous ground-based interferometers. A third space mission, the Planck Surveyor [1], was launched by ESA* in May 2009 to measure the CMB on smaller scales than WMAP, as well as making precise measurements of the polarization of CMB. Planck represents an advance over WMAP in several respects: it observes in higher resolution, hence allowing one to probe the CMB power spectrum to smaller scales; it has a higher sensitivity and observes in nine frequency bands rather than five, hence improving the astrophysical foreground models. The mission has a wide variety of scientific aims, including: (1) detecting the total intensity/polarization of the primordial CMB anisotropies; (2) creating a galaxy-cluster catalogue through the Sunyaev-Zel'dovich (SZ) effect [93]; (3) observing the

  15. Digital microwave communication engineering point-to-point microwave systems

    CERN Document Server

    Kizer, George

    2013-01-01

    The first book to cover all engineering aspects of microwave communication path design for the digital age Fixed point-to-point microwave systems provide moderate-capacity digital transmission between well-defined locations. Most popular in situations where fiber optics or satellite communication is impractical, it is commonly used for cellular or PCS site interconnectivity where digital connectivity is needed but not economically available from other sources, and in private networks where reliability is most important. Until now, no book has adequately treated all en

  16. Electron microscopy of microwave-synthesized rare-earth chromites

    OpenAIRE

    Schmidt, Rainer; Prado-Gonjal, Jesus; Avila, David; Amador, Ulises; Moran, Emilio

    2014-01-01

    The perovskite rare-earth (RE) chromite series (RE)CrO3 (RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, Ho, Er, Tm, Yb, Lu) has been synthesized in our laboratory using microwave techniques. In this work we will demonstrate how X-ray diffraction (XRD), Rietveld refinement of XRD pattern and complementary High Resolution Transmission Electron Microscopy (HRTEM) were used to confirm that the desired crystal structure had been formed. Field-emission scanning electron microscopy (FE-SEM) gave clear ...

  17. On Interactions of Microwave with Lightwave

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper addresses interactions of lightwave with microwave, and is divided into two parts. In part one, the background and the main topics of the research filed are introduced. In part two, some research activities at Shanghai University are reviewed.These include optical control of microwave devices, photoinduced electromagnetic radiation, lightwave interaction with superconductors, microwave control of lightwave, and the microwave approach to highly irregular fiber optics.

  18. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Bone Densitometry (DEXA) Bone densitometry, also called dual-energy ... limitations of DEXA Bone Densitometry? What is a Bone Density Scan (DEXA)? Bone density scanning, also called ...

  19. Microwave sintering of Ag-nanoparticle thin films on a polyimide substrate

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, S., E-mail: fujii.s.ap@m.titech.ac.jp [Department of Applied Chemistry, Tokyo Institute of Technology, Tokyo 152-8522 (Japan); Department of Information and Communication System Engineering, National Institute of Technology, Okinawa College, Nago, Okinawa 905-2192 (Japan); Kawamura, S.; Maitani, M. M.; Suzuki, E.; Wada, Y. [Department of Applied Chemistry, Tokyo Institute of Technology, Tokyo 152-8522 (Japan); Mochizuki, D. [Interdisciplinary Cluster for Cutting Edge Research, Center for Energy and Environmental Science, Shinshu University, Ueda, Nagano 386-8567 (Japan)

    2015-12-15

    Ag-nanoparticle thin films on a polyimide substrate were subjected to microwave sintering by use of a single-mode waveguide applicator. A two-step sintering process was employed. First, at low conductivities of the film, the film sample was placed at the site of the maximum electric field and subjected to microwave irradiation. Second, when the conductivity of the film increased, the film sample was placed at the site of the maximum magnetic field and again subjected to microwave irradiation. The microwave sintering process was completed within 1.5 min, which is significantly lower than the time required for the oven heating process. The resulting conductivity of the film, albeit only 30% of that of the bulk material, was seven times that of a film annealed at the same temperature in a furnace. Scanning electron microscopy images revealed that the nanoparticles underwent both grain necking and grain growth during microwave sintering. In addition, this sintering process was equivalent to the oven heating process performed at a 50 °C higher annealing temperature. An electromagnetic wave simulation and a heat transfer simulation of the microwave sintering process were performed to gain a thorough understanding of the process.

  20. Microwave sintering of Ag-nanoparticle thin films on a polyimide substrate

    Directory of Open Access Journals (Sweden)

    S. Fujii

    2015-12-01

    Full Text Available Ag-nanoparticle thin films on a polyimide substrate were subjected to microwave sintering by use of a single-mode waveguide applicator. A two-step sintering process was employed. First, at low conductivities of the film, the film sample was placed at the site of the maximum electric field and subjected to microwave irradiation. Second, when the conductivity of the film increased, the film sample was placed at the site of the maximum magnetic field and again subjected to microwave irradiation. The microwave sintering process was completed within 1.5 min, which is significantly lower than the time required for the oven heating process. The resulting conductivity of the film, albeit only 30% of that of the bulk material, was seven times that of a film annealed at the same temperature in a furnace. Scanning electron microscopy images revealed that the nanoparticles underwent both grain necking and grain growth during microwave sintering. In addition, this sintering process was equivalent to the oven heating process performed at a 50 °C higher annealing temperature. An electromagnetic wave simulation and a heat transfer simulation of the microwave sintering process were performed to gain a thorough understanding of the process.

  1. Microwave-driven asbestos treatment and its scale-up for use after natural disasters.

    Science.gov (United States)

    Horikoshi, Satoshi; Sumi, Takuya; Ito, Shigeyuki; Dillert, Ralf; Kashimura, Keiichiro; Yoshikawa, Noboru; Sato, Motoyasu; Shinohara, Naoki

    2014-06-17

    Asbestos-containing debris generated by the tsunami after the Great East Japan Earthquake of March 11, 2011, was processed by microwave heating. The analysis of the treated samples employing thermo gravimetry, differential thermal analysis, X-ray diffractometry, scanning electron microscopy, and phase-contrast microscopy revealed the rapid detoxification of the waste by conversion of the asbestos fibers to a nonfibrous glassy material. The detoxification by the microwave method occurred at a significantly lower processing temperature than the thermal methods actually established for the treatment of asbestos-containing waste. The lower treatment temperature is considered to be a consequence of the microwave penetration depth into the waste material and the increased intensity of the microwave electric field in the gaps between the asbestos fibers resulting in a rapid heating of the fibers inside the debris. A continuous treatment plant having a capacity of 2000 kg day(-1) of asbestos-containing waste was built in the area affected by the earthquake disaster. This treatment plant consists of a rotary kiln to burn the combustible waste (wood) and a microwave rotary kiln to treat asbestos-containing inorganic materials. The hot flue gas produced by the combustion of wood is introduced into the connected microwave rotary kiln to increase the energy efficiency of the combined process. Successful operation of this combined device with regard to asbestos decomposition is demonstrated.

  2. Synergistic effect of graphene-oxide-doping and microwave-curing on mechanical strength of cement

    Science.gov (United States)

    Qin, Hao; Wei, Wei; Hang Hu, Yun

    2017-04-01

    In this communication, efficient reinforcement of cement matrix was obtained by graphene-oxide (GO) doping and curing treatments. The compressive strength of plain cement is 14.3±0.2 MPa. When the cement contained 0.5 wt% GO, its strength reached 19.4±0.9 MPa. The strength can be further enhanced by curing, which follows the sequence: Microwave-cured GO-cement > Microwave and water-cured GO-cement > Water-cured GO-cement > GO-cement without curing. The highest compressive strength (32.4±0.7 MPa), which was achieved by combining GO-doping and microwave curing, is 126.6±8.1% higher than that without GO-doping and microwave curing. This demonstrates a synergistic effect of GO doping and microwave-curing on the strength of cement composite materials. Furthermore, X-ray diffraction (XRD), Fourier transform Infrared Spectroscopy (FTIR), and field emission scanning electron microscope (FESEM) characterizations revealed that the combination of GO doping and microwave-curing remarkably accelerated cement hydration, leading to the regular and compact structure and thus a high compressive strength. This work provides a new way to improve the mechanical properties of cement composites.

  3. Scanned-cantilever atomic force microscope with large scanning range

    Institute of Scientific and Technical Information of China (English)

    Jintao Yang; Wendong Xu

    2006-01-01

    A scanned-cantilever atomic force microscope (AFM) with large scanning range is proposed, which adopts a new design named laser spot tracking. The scanned-cantilever AFM uses the separate flexure x-y scanner and z scanner instead of the conventional piezoelectric tube scanner. The closed-loop control and integrated capacitive sensors of these scanners can insure that the images of samples have excellent linearity and stability. According to the experimental results, the scanned-cantilever AFM can realize maximal 100 × 100 (μm) scanning range, and 1-nm resolution in z direction, which can meet the requirements of large scale sample testing.

  4. Microwave Activation of Drug Release

    DEFF Research Database (Denmark)

    Jónasson, Sævar Þór

    Due to current limitations in control of pharmaceutical drug release in the body along with increasing medicine use, methods of externally-controlled drug release are of high interest. In this thesis, the use of microwaves is proposed as a technique with the purpose of externally activating...... setup, called the microwave activation system has been developed and tested on a body phantom that emulates the human torso. The system presented in this thesis, operates unobtrusively, i.e. without physically interfering with the target (patient). The torso phantom is a simple dual-layered cylindrical...... the phantom is of interest for disclosing essential information about the limitations of the concept, the phantom and the system. For these purposes, a twofold operation of the microwave activation system was performed, which are reciprocal of each other. In the first operation phase, named mapping...

  5. Compact Microwave Fourier Spectrum Analyzer

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry

    2009-01-01

    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  6. High power ferrite microwave switch

    Science.gov (United States)

    Bardash, I.; Roschak, N. K.

    1975-01-01

    A high power ferrite microwave switch was developed along with associated electronic driver circuits for operation in a spaceborne high power microwave transmitter in geostationary orbit. Three units were built and tested in a space environment to demonstrate conformance to the required performance characteristics. Each unit consisted of an input magic-tee hybrid, two non-reciprocal latching ferrite phase shifters, an out short-slot 3 db quadrature coupler, a dual driver electronic circuit, and input logic interface circuitry. The basic mode of operation of the high power ferrite microwave switch is identical to that of a four-port, differential phase shift, switchable circulator. By appropriately designing the phase shifters and electronic driver circuits to operate in the flux-transfer magnetization mode, power and temperature insensitive operation was achieved. A list of the realized characteristics of the developed units is given.

  7. Microwave heat treating of manufactured components

    Science.gov (United States)

    Ripley, Edward B.

    2007-01-09

    An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

  8. Microwave assisted centrifuge and related methods

    Science.gov (United States)

    Meikrantz, David H [Idaho Falls, ID

    2010-08-17

    Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

  9. Microwave Hydrothermal Synthesis PZT of Nanometer Crystal

    Institute of Scientific and Technical Information of China (English)

    Hongxing LIU; Hong DENG; Yan LI; Yanrong LI

    2004-01-01

    It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthesis system was established and the PZT piezoelectric ceramic powder was synthesized. XRD and TEM have been used to characterize the products in detail. The diameter of the PZT powder particle is from 40 to 60 nm.

  10. Status of the microwave power transmission components for the solar power satellite

    Science.gov (United States)

    Brown, W. C.

    1981-01-01

    During the 1970-1980 time period a substantial advance has been made in developing all portions of a microwave power transmission system for the solar power satellite (SPS). The most recent advances pertain to the transmitting portion of the system in the satellite and are based upon experimental observations of the use of the magnetron combined with a passive directional device to convert it into a highly efficient directional amplifier with excellent low-noise properties and potentially very long life. The ability of its microwave output to track a phase reference makes it possible to combine it with many other radiating units to provide a highly coherent microwave beam. The ability of its output to track an amplitude reference while operating from a dc power source with varying voltage makes it possible to eliminate most of the power conditioning equipment that would otherwise be necessary.

  11. Microwave Properties of Carbon Nanotubes Grown by Pyrolysis of Ethanol on Nickel Catalyst

    Directory of Open Access Journals (Sweden)

    V.V. Rodionov

    2014-07-01

    Full Text Available The efficiency of carbon nanotubes produced by CVD-method on a nickel catalyst at a protection from microwave radiation is shown. These data are confirmed by scanning electron microscopy, energy dispersive X-ray analysis and spectral analysis of the microwave radiation in the frequency range 26-40 GHz. The observed value of the transmission coefficient S21, up to – 42.7 dB, is in agreement with considered possible absorption mechanisms of electromagnetic wave energy in carbon nanoscale systems “CNT-nickel nanoparticles”. The application of carbon powder materials in shielding of electromagnetic radiation has been theoretically justified.

  12. A Scanning Cavity Microscope

    CERN Document Server

    Mader, Matthias; Hänsch, Theodor W; Hunger, David

    2014-01-01

    Imaging of the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1700-fold signal enhancement compared to diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross section of gold nanoparticles with a sensitivity below 1 nm2, we show a method to improve spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for opt...

  13. Micro scanning probes

    CERN Document Server

    Niblock, T

    2001-01-01

    This thesis covers the design methodology, theory, modelling, fabrication and evaluation of a Micro-Scanning-Probe. The device is a thermally actuated bimorph quadrapod fabricated using Micro Electro Mechanical Systems technology. A quadrapod is a structure with four arms, in this case a planar structure with the four arms forming a cross which is dry etched out of a silicon diaphragm. Each arm has a layer of aluminium deposited on it forming a bimorph. Through heating each arm actuation is achieved in the plane of the quadrapod and the direction normal to it. Fabrication of the device has required the development of bulk micromachining techniques to handle post CMOS fabricated wafers and the patterning of thickly sputtered aluminium in bulk micro machined cavities. CMOS fabrication techniques were used to incorporate diodes onto the quadrapod arms for temperature measurement of the arms. Fine tungsten and silicon tips have also been fabricated to allow tunnelling between the tip and the platform at the centr...

  14. Microwave materials for wireless applications

    CERN Document Server

    Cruickshank, David B

    2011-01-01

    This practical resource offers you an in-depth, up-to-date understanding of the use of microwave magnetic materials for cutting-edge wireless applications. The book discusses device applications used in wireless infrastructure base stations, point-to-point radio links, and a range of more specialized microwave systems. You find detailed discussions on the attributes of each family of magnetic materials with respect to specific wireless applications. Moreover, the book addresses two of the hottest topics in the field today - insertion loss and intermodulation. This comprehensive reference also

  15. Passive microwave soil moisture research

    Science.gov (United States)

    Schmugge, T.; Oneill, P. E.; Wang, J. R.

    1986-01-01

    During the four years of the AgRISTARS Program, significant progress was made in quantifying the capabilities of microwave sensors for the remote sensing of soil moisture. In this paper, a discussion is provided of the results of numerous field and aircraft experiments, analysis of spacecraft data, and modeling activities which examined the various noise factors such as roughness and vegetation that affect the interpretability of microwave emission measurements. While determining that a 21-cm wavelength radiometer was the best single sensor for soil moisture research, these studies demonstrated that a multisensor approach will provide more accurate soil moisture information for a wider range of naturally occurring conditions.

  16. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    V Subramanian

    2008-04-01

    Microwave band gap structures exhibit certain stop band characteristics based on the periodicity, impedance contrast and effective refractive index contrast. These structures though formed in one-, two- and three-dimensional periodicity, are huge in size. In this paper, microstrip-based microwave band gap structures are formed by removing the substrate material in a periodic manner. This paper also demonstrates that these structures can serve as a non-destructive characterization tool for materials, a duplexor and frequency selective coupler. The paper presents both experimental results and theoretical simulation based on a commercially available finite element methodology for comparison.

  17. Status of VESAS: a fully-electronic microwave imaging radiometer system

    Science.gov (United States)

    Schreiber, Eric; Peichl, Markus; Suess, Helmut

    2010-04-01

    Present applications of microwave remote sensing systems cover a large variety. One utilisation of the frequency range from 1 - 300 GHz is the domain of security and reconnaissance. Examples are the observation of critical infrastructures or the performance of security checks on people in order to detect concealed weapons or explosives, both being frequent threats in our world of growing international terrorism. The imaging capability of concealed objects is one of the main advantages of microwave remote sensing, because of the penetration performance of electromagnetic waves through dielectric materials in this frequency domain. The main physical effects used in passive microwave sensing rely on the naturally generated thermal radiation and the physical properties of matter, the latter being surface characteristics, chemical and physical composition, and the temperature of the material. As a consequence it is possible to discriminate objects having different material characteristics like ceramic weapons or plastic explosives with respect to the human body. Considering the use of microwave imaging with respect to people scanning systems in airports, railway stations, or stadiums, it is advantageous that passively operating devices generate no exposure on the scanned objects like actively operating devices do. For frequently used security gateways it is additionally important to have a high through-put rate in order to minimize the queue time. Consequently fast imaging systems are necessary. In this regard the conceptual idea of a fully-electronic microwave imaging radiometer system is introduced. The two-dimensional scanning mechanism is divided into a frequency scan in one direction and the method of aperture synthesis in the other. The overall goal here is to design a low-cost, fully-electronic imaging system with a frame rate of around one second at Ka band. This frequency domain around a center frequency of 37 GHz offers a well-balanced compromise between the

  18. The history of cerebral PET scanning

    Science.gov (United States)

    Portnow, Leah H.; Vaillancourt, David E.; Okun, Michael S.

    2013-01-01

    Objective: To review the discoveries underpinning the introduction of cerebral PET scanning and highlight its modern applications. Background: Important discoveries in neurophysiology, brain metabolism, and radiotracer development in the post–World War II period provided the necessary infrastructure for the first cerebral PET scan. Methods: A complete review of the literature was undertaken to search for primary and secondary sources on the history of PET imaging. Searches were performed in PubMed, Google Scholar, and select individual journal Web sites. Written autobiographies were obtained through the Society for Neuroscience Web site at www.sfn.org. A reference book on the history of radiology, Naked to the Bone, was reviewed to corroborate facts and to locate references. The references listed in all the articles and books obtained were reviewed. Results: The neurophysiologic sciences required to build cerebral PET imaging date back to 1878. The last 60 years have produced an evolution of technological advancements in brain metabolism and radiotracer development. These advancements facilitated the development of modern cerebral PET imaging. Several key scientists were involved in critical discoveries and among them were Angelo Mosso, Charles Roy, Charles Sherrington, John Fulton, Seymour Kety, Louis Sokoloff, David E. Kuhl, Gordon L. Brownell, Michael Ter-Pogossian, Michael Phelps, and Edward Hoffman. Conclusions: Neurophysiology, metabolism, and radiotracer development in the postwar era synergized the development of the technology necessary for cerebral PET scanning. Continued use of PET in clinical trials and current developments in PET-CT/MRI hybrids has led to advancement in diagnosis, management, and treatment of neurologic disorders. PMID:23460618

  19. Cosmic Microwave Background Mapping

    Science.gov (United States)

    Verkhodanov, O. V.; Doroshkevich, A. G.

    2012-03-01

    The last decade of research in cosmology was connected with the ambitious experiments including space and ground base observations. Among the most impressive results of these investigations are the measurements of the cosmic microwave background (CMB) radiation like WMAP* and Planck. Exactly from the CMB studies, we have started the epoch of the precision cosmology when generally the values of cosmological parameters have been known and present research is devoted to improvement of the precision. These achievements are connected with both the creation of the new facilities in millimeter and submillimeter astronomy (e.g., satellites, receivers, antennas, computers) and development of the methods for the CMB data analysis. Actually, the process of data analysis contains several technical stages including 1. Registration of time-ordered data (TOD) 2. Pixelization of the CMB data - map preparation 3. Component separation 4. Map statistics analysis 5. Map - spherical harmonics transformation 6. C(l)-spectrum calculation and spectrum statistics analysis 7. Cosmological parameters estimation Starting from the cosmic background explorer (COBE) experiment using the so-called Quadrilateralized Sky Cube Projection (see [1-3]), the problem of the whole sky CMB pixelization has attracted great interest and many such schemes were developed. Let us note however that accurate pixelization of the CMB data on the sphere is very important but not the final step of analysis. Usually, the next step implies the determination of the coefficients of the spherical harmonic decomposition of the CMB signal for both anisotropy and polarization. This means that some of the pixelization schemes provide a very accurate map but are inconvenient for further decomposition. This also means that the choice of suitable pixelization schemes depends upon the general goals of the investigation. In this review, we consider several of the most popular sky map pixelization schemes and link them with the

  20. A scanning transmon qubit for strong coupling circuit quantum electrodynamics.

    Science.gov (United States)

    Shanks, W E; Underwood, D L; Houck, A A

    2013-01-01

    Like a quantum computer designed for a particular class of problems, a quantum simulator enables quantitative modelling of quantum systems that is computationally intractable with a classical computer. Superconducting circuits have recently been investigated as an alternative system in which microwave photons confined to a lattice of coupled resonators act as the particles under study, with qubits coupled to the resonators producing effective photon-photon interactions. Such a system promises insight into the non-equilibrium physics of interacting bosons, but new tools are needed to understand this complex behaviour. Here we demonstrate the operation of a scanning transmon qubit and propose its use as a local probe of photon number within a superconducting resonator lattice. We map the coupling strength of the qubit to a resonator on a separate chip and show that the system reaches the strong coupling regime over a wide scanning area.

  1. Propagation in 3D of microwaves through density perturbations

    CERN Document Server

    Williams, T R N; O'Brien, M R; Vann, R G L

    2013-01-01

    Simulations using 3D and 2D full-wave codes have shown that edge filaments in tokamak plasmas can significantly affect the propagation of microwaves across a broad frequency spectrum, resulting in scattering angles of up to 46 degrees. Parameter scans were carried out for density perturbations comparable in width and amplitude to MAST filaments and the effect on the measured emission was calculated. 3D effects were discovered in the case of an obliquely incident beam. In general, the problem of EM propagation past wavelength-sized 3D inhomogeneities is not well understood, yet is of importance for both heating and diagnostic applications in the electron cyclotron frequency range for tokamaks, as well as atmospheric physics. To improve this understanding, a new cold-plasma code, EMIT-3D, was written to extend full-wave microwave simulations in magnetized plasmas to 3D, and make comparisons to the existing 2D code IPF-FDMC. This work supports MAST experiments using the SAMI diagnostic to image microwave emissio...

  2. MICROWAVE RADIATIONS FOR HEAT-SETTING OF POLYESTER FIBERS

    Directory of Open Access Journals (Sweden)

    Ajit V.Gore

    2009-12-01

    Full Text Available The use of radio and microwave frequency is gainingimportance for industrial applications such asheating, drying, and other processing. The mostimportant advantage of using microwave is that it isnon-contact or localized heating and the heat isproduced within the material. This can be much moreeffective than indirect heating where the heatpropagation is by heat conduction through thematerial. We have been investigating the influence ofmicrowave radiation on different fibers for the lastfew years. In the present investigation we usedmicrowave frequency of 2450 MHz to investigate itseffect on polyester fibers. The polyester fibers wereheat set in air as well as a liquid, which acted as alossy substances. The liquid was chosen on the basisof earlier experiments, which showed the maximumeffect. A comparative study was also carried outusing conventional heating in silicone oil.Using the method of X-ray Diffraction (XRD wecalculated the changes in % crystallinity andorientation. It was found that as the time of treatmentunder microwave radiation increased from 15 sec. to120 sec. the order factor was found to increase from0.32 to 0.71.The crystalline orientation as determinedfrom the azimuthal scan was also found to increase.Such structural changes can be highly beneficial forthe processing of fabric in industry. The microwaveradiation process is fast, reliable and energy saving.

  3. Springtime microwave emissivity changes in the southern Kara Sea

    Science.gov (United States)

    Crane, Robert G.; Anderson, Mark R.

    1994-01-01

    Springtime microwave brightness temperatures over first-year ice are examined for the southern Kara Sea. Snow emissivity changes are revealed by episodic drops in the 37- to 18-GHz brightness temperature gradient ratio measured by the Nimbus 7 scanning multichannel microwave radiometer. We suggest that the negative gradient ratios in spring 1982 result from increased scatter at 37 GHz due to the formation of a near-surface hoar layer. This interpretation is supported by the results of a surface radiation balance model that shows the melt signature occurring at below freezing temperatures but under clear-sky conditions with increased solar input to the surface. Published observations from the Greenland ice cap show a surface hoar layer forming under similar atmospheric conditions owing to the increased penetration and absorption of solar radiation just below the surface layer. In spring/early summer 1984 similar gradient ratio signatures occur. They appear to be due to several days of freeze-thaw cycling following the movement of a low-pressure system through the region. These changes in surface emissivity represent the transition from winter to summer conditions (as defined by the microwave response) and are shown to be regional in extent and to vary with the synoptic circulations.

  4. Microwave sintering of nano size powder β-TCP bioceramics

    Directory of Open Access Journals (Sweden)

    Mirhadi B.

    2014-01-01

    Full Text Available A nano sized beta tricalcium phosphate (β-TCP powder was conventional sintered (CS and microwave sintered (MW, in order to obtain dense β-TCP ceramics. In this work the effect of microwave sintering conditions on the microstructure, phase composition and mechanical properties of materials based on tricalcium phosphate (TCP was investigated by SEM (scanning electron microscopyand XRD(X-ray diffraction and then compared with conventional sintered samples. Nano-size β-TCP powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and diammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of submicrometre β-TCP powder in situ. The β-TCP samples microwave (MW sintered for 15 min at 1100°C, with average grain size of 3μm, showed better densification, higher density and certainly higher hardness than samples conventionally sintered for 2 h at the same temperature. By comparing sintered and MW sintered β-TCP samples, it was concluded that MW sintered β-TCP samples have superior mechanical properties.

  5. Microwave plasmatrons for giant integrated circuit processing

    Energy Technology Data Exchange (ETDEWEB)

    Petrin, A.B.

    2000-02-01

    A method for calculating the interaction of a powerful microwave with a plane layer of magnetoactive low-pressure plasma under conditions of electron cyclotron resonance is presented. In this paper, the plasma layer is situated between a plane dielectric layer and a plane metal screen. The calculation model contains the microwave energy balance, particle balance, and electron energy balance. The equation that expressed microwave properties of nonuniform magnetoactive plasma is found. The numerical calculations of the microwave-plasma interaction for a one-dimensional model of the problem are considered. Applications of the results for microwave plasmatrons designed for processing giant integrated circuits are suggested.

  6. Solid-state microwave switches: Circuitry, manufacturing technologies and development trends. Review (Part 2)

    OpenAIRE

    Berezniak, Anatolii; Korotkov, Alexander S.

    2013-01-01

    This paper presents an overview of the process and design capabilities of state-of-the-art in the field of microwave solid state switches. The paper describes types of solid state switches, switch specifications, a review of technological advances in this area. The overview results indicate that AlGaN/GaN MMICs including solid state switches are realizable.

  7. Solid-state microwave switches: circuitry, manufacturing technologies and development trends. Review (Part 1)

    OpenAIRE

    Berezniak, Anatolii; Korotkov, Alexander S.

    2013-01-01

    This paper presents an overview of the process and design capabilities of state-of-the-art in the field of microwave solid state switches. The paper describes types of solid state switches, switch specifications, a review of technological advances in this area. The overview results indicate that AlGaN/GaN MMICs including solid state switches are realizable.

  8. Adaptive mode-dependent scan for H.264/AVC intracoding

    Science.gov (United States)

    Wei, Yung-Chiang; Yang, Jar-Ferr

    2010-07-01

    In image/video coding standards, the zigzag scan provides an effective encoding order of the quantized transform coefficients such that the quantized coefficients can be arranged statistically from large to small magnitudes. Generally, the optimal scan should transfer the 2-D transform coefficients into 1-D data in descending order of their average power levels. With the optimal scan order, we can achieve more efficient variable length coding. In H.264 advanced video coding (AVC), the residuals resulting from various intramode predictions have different statistical characteristics. After analyzing the transformed residuals, we propose an adaptive scan order scheme, which optimally matches up with intraprediction mode, to further improve the efficiency of intracoding. Simulation results show that the proposed adaptive scan scheme can improve the context-adaptive variable length coding to achieve better rate-distortion performance for the H.264/AVC video coder without the increase of computation.

  9. National University Consortium on Microwave Research (NUCOMR)

    Science.gov (United States)

    Barker, Robert J.; Agee, Forrest J.

    1995-09-01

    This paper introduces a new cooperative research program of national scale that is focused on crucial research issues in the development of high energy microwave sources. These have many applications in the DOD and industry. The Air Force Office of Scientific Research (AFOSR), in coopertaion with the Phillips Laboratory, the Naval Research Laboratory, and the Army Research Laboratory, has established a tri-service research consortium to investigate novel high energy microwave sources. The program is part of the DODs 'Multidisciplinary University Research Initiative' and will be funded at a rate of $DLR3.0M per year for up to five years. All research performed under this program will be unclassified. Under its auspices, HPM scientists at nine US universities will be attacking twenty-two separate research projects under the leadership of Neville Luhmann at UC-Davis, Victor Granatstein at Maryland, Magne Kristiansen at Texas Tech, Edl Schamiloglu at New Mexico, John Nation at Cornell, Ned Birdsall at UC-Berkeley, George Caryotakis at Standord, Ronald Gilgenbach at Michigan, and Anthony Lin at UCLA. To facilitate the rapid transition of research results into the industrial community, formal collaborative subcontracts are already in place with James Benford at Physics International, Carter Armstrong at Northrop, and Glen Huffman at Varian Associates. Although this new program officially only came into existence in mid-March of this year, it builds on over a decade of microwave research efforts funded by the plasma physics office at AFOSR. It also is synergistic with the ongoing Tri-Service Vacuum Electronics Initiative led by Robert Parker of NRL as well as with the AFOSR's and Rome Laboratory's long standing Advanced Thermionic Research Initiative. An overview will be given of the broad spectrum of research objectives encompassed by NUCOMR. Areas of collaboration and technology transfer will be highlighted. The areas in which the three university consortia will conduct

  10. Progress in CPI Microwave Tube Development

    Science.gov (United States)

    Wright, Edward L.; Bohlen, Heinz

    2006-01-01

    CPI continues its role as a leading supplier of state-of-the-art, high-power microwave tubes; from linear beam, velocity- and density-modulated devices, to high frequency gyro-devices. Klystrons are the device-of-choice for many high-power microwave applications, and can provide multi-megawatts to multi-kilowatts of power from UHF to W-band, respectively. A number of recent and on-going developments will be described. At UHF frequencies, the inductive output tube (IOT) has replaced the klystron for terrestrial NTSC and HDTV broadcast, due to its high efficiency and linearity, and is beginning to see use in scientific applications requiring 300 kW or less. Recent advances have enabled use well into L-band. CPI has developed a number of multiple-beam amplifiers. The VKL-8301 multiple-beam klystron (MBK) was built for the TESLA V/UV and x-ray FEL projects, and is a candidate RF source for the International Linear Collider (ILC). We have also contributed to the development of the U.S. Naval Research Laboratory (NRL) high-power fundamental-mode S-band MBK. The VHP-8330B multiple-beam, high-order mode (HOM) IOT shows great promise as a compact, CW UHF source for high power applications. These topics will be discussed, along with CPI's development capabilities for new and novel applications. Most important is our availability to provide design and fabrication services to organizations requiring CPI's manufacturing and process control infrastructure to build and test state-of-the-art devices.

  11. Nanoscale microwave imaging with a single electron spin in diamond

    Science.gov (United States)

    Appel, Patrick; Ganzhorn, Marc; Neu, Elke; Maletinsky, Patrick

    2015-11-01

    We report on imaging of microwave (MW) magnetic fields using a magnetometer based on the electron spin of a nitrogen vacancy (NV) center in diamond. We quantitatively image the magnetic field generated by high frequency (GHz) MW current with nanoscale resolution using a scanning probe technique. Together with a shot noise limited MW magnetic field sensitivity of 680 nT Hz-1/2 our room temperature experiments establish the NV center as a versatile and high performance tool for MW imaging, which furthermore offers polarization selectivity and broadband capabilities. As a first application of this scanning MW detector, we image the MW stray field around a stripline structure and thereby locally determine the MW current density with a MW current sensitivity of a few nA Hz-1/2.

  12. Terahertz and Microwave Devices Based on the Photo-Excited Low Dimensional Electronic System

    Science.gov (United States)

    2015-03-11

    condition that is realized by photo-exciting the system with electromagnetic waves in the microwave and THz parts of the radiation spectrum, in the...electron system. This research aimed to advance the understanding of such radiation -induced phenomena in the two-dimensional electron system, while helping...exciting a high mobility low dimensional electron system. This research aimed to advance the understanding of such radiation -induced phenomena in the two

  13. 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

    2012-06-01

    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 on near-surface soil moisture products derived from actual (non-synthetic 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 related to dynamic estimates of open water fraction, one retrieved from a global daily record based on higher frequency AMSR-E data, a second derived from the Moderate Resolution Imaging Spectroradiometer (MODIS and a third through inversion of the radiative transfer model, used to retrieve soil moisture. The comparison demonstrates the presence of relatively small areas (<0.05 of open water in or near the sensor footprint, possibly in combination with increased, below-critical vegetation density conditions (optical density <0.8, which contribute to seasonally varying biases in excess of 0.2 (m3 m−3 soil water content. These errors need to be addressed, either through elimination or accurate characterisation, if the soil moisture retrievals are to be used effectively in a data assimilation scheme.

  14. Estimation of melt pond fraction over high-concentration Arctic sea ice using AMSR-E passive microwave data

    Science.gov (United States)

    Tanaka, Yasuhiro; Tateyama, Kazutaka; Kameda, Takao; Hutchings, Jennifer K.

    2016-09-01

    Melt pond fraction (MPF) on sea ice is an important factor for ice-albedo feedback throughout the Arctic Ocean. We propose an algorithm to estimate MPF using satellite passive microwave data in this study. The brightness temperature (TB) data obtained from the Advanced Microwave Scanning Radiometer-Earth observing system (AMSR-E) were compared to the ship-based MPF in the Beaufort Sea and Canadian Arctic Archipelago. The difference between the TB at horizontal and vertical polarizations of 6.9 and 89.0 GHz (MP06H-89V), respectively, depends on the MPF. The correlation between MP06H-89V and ship-based MPF was higher than that between ship-based MPF and two individual channels (6.9 and 89.0 GHz of horizontal and vertical polarizations, respectively). The MPF determined with the highest resolution channel, 89.0 GHz (5 km × 5 km), provides spatial information with more detail than the 6.9 GHz channel. The algorithm estimates the relative fraction of ice covered by water (1) over areas where sea ice concentration is higher than 95%, (2) during late summer, and (3) in areas with low atmospheric humidity. The MPF estimated from AMSR-E data (AMSR-E MPF) in early summer was underestimated at lower latitudes and overestimated at higher latitudes, compared to the MPF obtained from the Moderate Resolution Image Spectrometer (MODIS MPF). The differences between AMSR-E MPF and MODIS MPF were less than 5% in most the regions and the periods. Our results suggest that the proposal algorithm serves as a basis for building time series of MPF in regions of consolidated ice pack.

  15. Metamaterial Absorbers for Microwave Detection

    Science.gov (United States)

    2015-06-01

    ABSORBERS FOR MICROWAVE DETECTION by Michael T. McMahan June 2015 Thesis Advisor: Dragoslav Grbovic Co-Advisor: Richard C. Olsen THIS PAGE......presented. 14. SUBJECT TERMS metamaterials, metamaterial absorbers , metamaterial detectors 15. NUMBER OF PAGES 65 16. PRICE

  16. ULTRARAPID VACUUM-MICROWAVE HISTOPROCESSING

    NARCIS (Netherlands)

    KOK, LP; BOON, ME

    1995-01-01

    A novel histoprocessing method for paraffin sections is presented in which the combination of vacuum and microwave exposure is the key element. By exploiting the decrease in boiling temperature under vacuum, the liquid molecules in the tissues have been successfully extracted and exchanged at relati

  17. Microwave Oven Repair. Teacher Edition.

    Science.gov (United States)

    Smreker, Eugene

    This competency-based curriculum guide for teachers addresses the skills a technician will need to service microwave ovens and to provide customer relations to help retain the customer's confidence in the product and trust in the service company that performs the repair. The guide begins with a task analysis, listing 20 cognitive tasks and 5…

  18. Wireless Power Transmission Using Microwaves

    Directory of Open Access Journals (Sweden)

    Nikhil B. Dhake

    2012-04-01

    Full Text Available In this paper, we present the concept of wireless power transmission to cut the clutter or lead to clean sources of electricity. It will eradicate the hazardous usage of electrical wires which involve lot of confusion in particularly organizing them. The plan is transmitting power as microwaves from one place to another in order to reduce the use of clumsy wires

  19. Microwave sintering of ceramic materials

    Science.gov (United States)

    Karayannis, V. G.

    2016-11-01

    In the present study, the potential of microwave irradiation as an innovative energy- efficient alternative to conventional heating technologies in ceramic manufacturing is reviewed, addressing the advantages/disadvantages, while also commenting on future applications of possible commercial interest. Ceramic materials have been extensively studied and used due to several advantages they exhibit. Sintering ceramics using microwave radiation, a novel technology widely employed in various fields, can be an efficient, economic and environmentally-friendlier approach, to improve the consolidation efficiency and reduce the processing cycle-time, in order to attain substantial energy and cost savings. Microwave sintering provides efficient internal heating, as energy is supplied directly and penetrates the material. Since energy transfer occurs at a molecular level, heat is generated throughout the material, thus avoiding significant temperature gradients between the surface and the interior, which are frequently encountered at high heating rates upon conventional sintering. Thus, rapid, volumetric and uniform heating of various raw materials and secondary resources for ceramic production is possible, with limited grain coarsening, leading to accelerated densification, and uniform and fine-grained microstructures, with enhanced mechanical performance. This is particularly important for manufacturing large-size ceramic products of quality, and also for specialty ceramic materials such as bioceramics and electroceramics. Critical parameters for the process optimization, including the electromagnetic field distribution, microwave-material interaction, heat transfer mechanisms and material transformations, should be taken into consideration.

  20. Microwave Treatment for Cardiac Arrhythmias

    Science.gov (United States)

    Hernandez-Moya, Sonia

    2009-01-01

    NASA seeks to transfer the NASA developed microwave ablation technology, designed for the treatment of ventricular tachycardia (irregular heart beat), to industry. After a heart attack, many cells surrounding the resulting scar continue to live but are abnormal electrically; they may conduct impulses unusually slowly or fire when they would typically be silent. These diseased areas might disturb smooth signaling by forming a reentrant circuit in the muscle. The objective of microwave ablation is to heat and kill these diseased cells to restore appropriate electrical activity in the heart. This technology is a method and apparatus that provides for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In comparison with other methods that involve direct-current pulses or radio frequencies below 1 GHz, this method may prove more effective in treating ventricular tachycardia. This is because the present method provides for greater control of the location, cross-sectional area, and depth of a lesion via selection of the location and design of the antenna and the choice of microwave power and frequency.

  1. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc bias...

  2. Recording and Scanning Advances in Cartographic EBR Systems.

    Science.gov (United States)

    1981-06-01

    Grids Plotted in Vector Mode ... ............. . 2-5 4 Aviation FLIP Chart Recorded in Vector Mode ...... .................. . 2-6 5 Enlargement of...of Multiup Microform Containing 16 AAIPS FLIP Charts .. .......... . 3-3 ii 11G11 PREFACE The work described in this report was authorized by the U.S...separations Continuous tone imagery from satellite and aerial reconnaissance sensors data Radar imagery Flight Information Publications ( FLIP ) Charts and Texts

  3. Solid state physics: advanced spectroscopy, scanning probe microscopy, nanostructure fabrication

    CERN Document Server

    Aghion, Stefano

    Thin films of hybrid solar cells and metal oxide semiconductors -IGZO in particular– and homogeneous PMMA polymers have been studied at the Positron Laboratory (L-NESS centre, Politecnico di Milano, Polo Territoriale di Como). A slow energy positron beam and a positron lifetime spectrometer have been employed for these studies. The positron spectroscopy information have been correlated with electrical and optical properties of the materials. The chemical composition and the morphology of voids and porosities in hybrid solar cells and thin film metal oxide semiconductors have been studied, and a strong correlation between positronium fraction, S-parameter and the electrical properties of these materials has been found. In PMMA polymers, free volume measurements have shown that the optical properties of the material depend on the presence of monomer residual fraction and even slight changes in the dimensions and concentration of free volumes. Positrons have been also applied to the study of positron to positr...

  4. Advanced material separation technique based on dual energy CT scanning

    Science.gov (United States)

    Zamyatin, Alexander A.; Natarajan, Anusha; Zou, Yu

    2009-02-01

    We propose a method for material separation using dual energy data. Our method is suitable to separation of three or more materials. In this work we describe our method and show results of numerical simulation and with real dual-energy data of a head phantom. The proposed method of constructing the material separation map consists of the following steps: Data-domain dual energy decomposition - Vector plot - Density plot - Clustering - Color assignment. Density plots are introduced to allow automatic cluster separation. We use special image processing methods, including Gaussian decomposition, to improve the accuracy of material separation. We also propose using the HSL color model for better visualization and to bring a new dimension in material separation display. We study applications of bone removal and virtual contrast removal. Evaluation shows improved accuracy compared to standard methods.

  5. GPR scan assessment

    Directory of Open Access Journals (Sweden)

    Abbas M. Abbas

    2015-06-01

    Full Text Available Mekaad Radwan monument is situated in the neighborhood of Bab Zuweila in the historical Cairo, Egypt. It was constructed at the middle XVII century (1635 AD. The building has a rectangle shape plan (13 × 6 m with the longitudinal sides approximately WNW-ESE. It comprises three storages namely; the ground floor; the opened floor (RADWAN Bench and the living floor with a total elevation of 15 m above the street level. The building suffers from severe deterioration phenomena with patterns of damage which have occurred over time. These deterioration and damages could be attributed to foundation problems, subsoil water and also to the earthquake that affected the entire Greater Cairo area in October 1992. Ground Penetrating Radar (GPR scan was accomplished against the walls of the opened floor (RADWAN Bench to evaluate the hazard impact on the walls textures and integrity. The results showed an anomalous feature through the southern wall of RADWAN Bench. A mathematical model has been simulated to confirm the obtained anomaly and the model response exhibited a good matching with the outlined anomaly.

  6. Differential scanning calorimetry.

    Science.gov (United States)

    Spink, Charles H

    2008-01-01

    Differential scanning calorimetry (DSC) has emerged as a powerful experimental technique for determining thermodynamic properties of biomacromolecules. The ability to monitor unfolding or phase transitions in proteins, polynucleotides, and lipid assemblies has not only provided data on thermodynamic stability for these important molecules, but also made it possible to examine the details of unfolding processes and to analyze the characteristics of intermediate states involved in the melting of biopolymers. The recent improvements in DSC instrumentation and software have generated new opportunities for the study of the effects of structure and changes in environment on the behavior of proteins, nucleic acids, and lipids. This review presents some of the details of application of DSC to the examination of the unfolding of biomolecules. After a brief introduction to DSC instrumentation used for the study of thermal transitions, the methods for obtaining basic thermodynamic information from the DSC curve are presented. Then, using DNA unfolding as an example, methods for the analysis of the melting transition are presented that allow deconvolution of the DSC curves to determine more subtle characteristics of the intermediate states involved in unfolding. Two types of transitions are presented for analysis, the first example being the unfolding of two large synthetic polynucleotides, which display high cooperativity in the melting process. The second example shows the application of DSC for the study of the unfolding of a simple hairpin oligonucleotide. Details of the data analysis are presented in a simple spreadsheet format.

  7. LANL Robotic Vessel Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Nels W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-25

    Los Alamos National Laboratory in J-1 DARHT Operations Group uses 6ft spherical vessels to contain hazardous materials produced in a hydrodynamic experiment. These contaminated vessels must be analyzed by means of a worker entering the vessel to locate, measure, and document every penetration mark on the vessel. If the worker can be replaced by a highly automated robotic system with a high precision scanner, it will eliminate the risks to the worker and provide management with an accurate 3D model of the vessel presenting the existing damage with the flexibility to manipulate the model for better and more in-depth assessment.The project was successful in meeting the primary goal of installing an automated system which scanned a 6ft vessel with an elapsed time of 45 minutes. This robotic system reduces the total time for the original scope of work by 75 minutes and results in excellent data accumulation and transmission to the 3D model imaging program.

  8. A One-Dimensional Synthetic-Aperture Microwave Radiometer

    Science.gov (United States)

    Doiron, Terence; Piepmeier, Jeffrey

    2010-01-01

    A proposed one-dimensional synthetic- aperture microwave radiometer could serve as an alternative to either the two-dimensional synthetic-aperture radiometer described in the immediately preceding article or to a prior one-dimensional one, denoted the Electrically Scanned Thinned Array Radiometer (ESTAR), mentioned in that article. The proposed radiometer would operate in a pushbroom imaging mode, utilizing (1) interferometric cross-track scanning to obtain cross-track resolution and (2) the focusing property of a reflector for along-track resolution. The most novel aspect of the proposed system would be the antenna (see figure), which would include a cylindrical reflector of offset parabolic cross section. The reflector could be made of a lightweight, flexible material amenable to stowage and deployment. Other than a stowage/deployment mechanism, the antenna would not include moving parts, and cross-track scanning would not entail mechanical rotation of the antenna. During operation, the focal line, parallel to the cylindrical axis, would be oriented in the cross-track direction, so that placement of receiving/radiating elements at the focal line would afford the desired along-track resolution. The elements would be microwave feed horns sparsely arrayed along the focal line. The feed horns would be oriented with their short and long cross-sectional dimensions parallel and perpendicular, respectively, to the cylindrical axis to obtain fan-shaped beams having their broad and narrow cross-sectional dimensions parallel and perpendicular, respectively, to the cylindrical axis. The interference among the beams would be controlled in the same manner as in the ESTAR to obtain along-cylindrical- axis (cross-track) resolution and cross-track scanning.

  9. Scanning array radar system for bridge subsurface imaging

    Science.gov (United States)

    Lai, Chieh-Ping; Ren, Yu-Jiun; Yu, Tzu Yang

    2012-04-01

    Early damage detection of bridge has been an important issue for modern civil engineering technique. Existing bridge inspection techniques used by State Department of Transportation (DOT) and County DOT include visual inspection, mechanical sounding, rebound hammer, cover meter, electrical potential measurements, and ultrasonics; other NDE techniques include ground penetrating radar (GPR), radiography, and some experimental types of sensors. Radar technology like GPR has been widely used for the bridge structure detection with a good penetration depth using microwave energy. The system to be presented in this paper is a different type of microwave sensing technology. It is focus on the subsurface detection and trying to find out detail information at subsurface (10 cm) with high resolution radar imaging from a flexible standoff distance. Our radar operating frequency is from 8-12 GHz, which is different from most of the current GPR systems. Scanning array antenna system is designed for adjustable beamwidth, preferable scanning area, and low sidelobe level. From the theoretical analysis and experimental results, it is found that the proposed technique can successfully capture the presence of the near-surface anomaly. This system is part of our Multi- Modal Remote Sensing System (MRSS) and provides good imaging correlations with other MRSS sensors.

  10. ADVANCED CERAMIC MATERIALS FOR DENTAL APPLICATIONS SINTERED BY MICROWAVE HEATING

    OpenAIRE

    Presenda Barrera, Álvaro

    2016-01-01

    [EN] Zirconia has become a widely utilized structural ceramic material with important applications in dentistry due to its superb mechanical properties, biocompatibility, aesthetic characteristics and durability. Zirconia needs to be stabilized in the t-phase to obtain improved mechanical properties such as hardness and fracture toughness. Fully dense yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) materials are normally consolidated through the energy-intensive processing of po...

  11. Recent Advances in Short-Range Microwave Imaging in Europe

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    RecentAdvancesinShort┐RangeMicrowaveImaginginEuropeMateoPastorino(DepartmentofBiophysicalandElectronicEngineering,Universityo...

  12. Advanced Microwave Ferrite Research (AMFeR): Phase Three

    Science.gov (United States)

    2008-07-31

    samples are kept in the high magnetic field for 48 hours, and then released and cured at room temperature for another 48 hours. Figure 3. Substrate...material source named target, such Au, Cu , or Ti. The substrate is placed in a vacuum chamber with the target and an inert gas, such as argon, is introduced...Propagation in Ferrite or polarization terms to Ampere’s law (as in the case of Debye Media [5], Lorentz [6] or plasma media [7]). By doing so, we never

  13. Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

    Science.gov (United States)

    Coillet, Aurélien; Henriet, Rémi; Phan Huy, Kien; Jacquot, Maxime; Furfaro, Luca; Balakireva, Irina; Larger, Laurent; Chembo, Yanne K.

    2013-01-01

    Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency. PMID:23963358

  14. Microwave photonics systems based on whispering-gallery-mode resonators.

    Science.gov (United States)

    Coillet, Aurélien; Henriet, Rémi; Phan Huy, Kien; Jacquot, Maxime; Furfaro, Luca; Balakireva, Irina; Larger, Laurent; Chembo, Yanne K

    2013-08-05

    Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

  15. Effect of deposition parameters on the structural properties of ZnO nanopowders prepared by microwave-assisted hydrothermal synthesis.

    Science.gov (United States)

    Caglar, Yasemin; Gorgun, Kamuran; Aksoy, Seval

    2015-03-05

    ZnO nanopowders were synthesized via microwave-assisted hydrothermal method at different deposition (microwave irradiation) times and pH values. The effects of pH and deposition (microwave irradiation) time on the crystalline structure and orientation of the ZnO nanopowders have been investigated by X-ray diffraction (XRD) study. XRD observations showed that the crystalline quality of ZnO nanopowders increased with increasing pH value. The crystallite size and texture coefficient values of ZnO nanopowders were calculated. The structural quality of ZnO nanopowder was improved by deposition parameters. Field emission scanning electron microscope (FESEM) was used to analyze the surface morphology of the ZnO nanopowders. Microwave irradiation time and pH value showed a significant effect on the surface morphology.

  16. Production of phenol-rich bio-oil during catalytic fixed-bed and microwave pyrolysis of palm kernel shell.

    Science.gov (United States)

    Omoriyekomwan, Joy Esohe; Tahmasebi, Arash; Yu, Jianglong

    2016-05-01

    Catalytic fixed-bed and microwave pyrolysis of palm kernel shell using activated carbon (AC) and lignite char (LC) as catalysts and microwave receptors are investigated. The effects of process parameters including temperature and biomass:catalyst ratio on the yield and composition of pyrolysis products were studied. The addition of catalyst increased the bio-oil yield, but decreased the selectivity of phenol in fixed-bed. Catalytic microwave pyrolysis of PKS significantly enhanced the selectivity of phenol production. The highest concentration of phenol in bio-oil of 64.58 %(area) and total phenolics concentration of 71.24 %(area) were obtained at 500°C using AC. Fourier transform infrared spectroscopy (FTIR) results indicated that concentration of OH, CH, CO and CO functional groups in char samples decreased after pyrolysis. Scanning electron microscopy (SEM) analysis clearly indicated the development of liquid phase in biomass particles during microwave pyrolysis, and the mechanism is also discussed.

  17. A microwave satellite water vapour column retrieval for polar winter conditions

    Science.gov (United States)

    Perro, Christopher; Lesins, Glen; Duck, Thomas J.; Cadeddu, Maria

    2016-05-01

    A new microwave satellite water vapour retrieval for the polar winter atmosphere is presented. The retrieval builds on the work of Miao et al. (2001) and Melsheimer and Heygster (2008), employing auxiliary information for atmospheric conditions and numerical optimization. It was tested using simulated and actual measurements from the Microwave Humidity Sounder (MHS) satellite instruments. Ground truth was provided by the G-band vapour radiometer (GVR) at Barrow, Alaska. For water vapour columns less than 6 kg m-2, comparisons between the retrieval and GVR result in a root mean square (RMS) deviation of 0.39 kg m-2 and a systematic bias of 0.08 kg m-2. These results are compared with RMS deviations and biases at Barrow for the retrieval of Melsheimer and Heygster (2008), the AIRS and MIRS satellite data products, and the ERA-Interim, NCEP, JRA-55, and ASR reanalyses. When applied to MHS measurements, the new retrieval produces a smaller RMS deviation and bias than for the earlier retrieval and satellite data products. The RMS deviations for the new retrieval were comparable to those for the ERA-Interim, JRA-55, and ASR reanalyses; however, the MHS retrievals have much finer horizontal resolution (15 km at nadir) and reveal more structure. The new retrieval can be used to obtain pan-Arctic maps of water vapour columns of unprecedented quality. It may also be applied to measurements from the Special Sensor Microwave/Temperature 2 (SSM/T2), Advanced Microwave Sounding Unit B (AMSU-B), Special Sensor Microwave Imager/Sounder (SSMIS), Advanced Technology Microwave Sounder (ATMS), and Chinese MicroWave Humidity Sounder (MWHS) instruments.

  18. The Upper Atmosphere Research Satellite microwave limb sounder instrument

    Science.gov (United States)

    Barath, F. T.; Chavez, M. C.; Cofield, R. E.; Flower, D. A.; Frerking, M. A.; Gram, M. B.; Harris, W. M.; Holden, J. R.; Jarnot, R. F.; Kloezeman, W. G.

    1993-01-01

    The microwave limb sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is the first satellite experiment using limb sounding techniques at microwave frequencies. Primary measurement objectives are stratospheric ClO, O3, H2O, temperature, and pressure. Measurements are of thermal emission: all are performed simultaneously and continuously and are not degraded by ice clouds or volcanic aerosols. The instrument has a 1.6-m mechanically scanning antenna system and contains heterodyne radiometers in spectral bands centred near 63, 183, and 205 GHz. The radiometers operate at ambient temperature and use Schottky-diode mixers with local oscillators derived from phase-locked Gunn oscillators. Frequency tripling by varactor multipliers generates the 183- and 205-GHz local oscillators, and quasi-optical techniques inject these into the mixers. Six 15-channel filter banks spectrally resolve stratospheric thermal emission lines and produce an output spectrum every 2 s. Thermal stability is sufficient for 'total power' measurements which do not require fast chopping. Radiometric calibration, consisting of measurements of cold space and an internal target, is performed every 65-s limb scan. Instrument in-orbit performance has been excellent, and all objectives are being met.

  19. In situ impedance measurement of microwave atmospheric pressure plasma

    Science.gov (United States)

    Lee, S. T.; Nam, W. J.; Lee, J. K.; Yun, G. S.

    2017-04-01

    The impedance of atmospheric pressure argon plasma jets driven by microwave frequency is determined in situ by a novel ‘two frequency method’. In the conventional method of reflection coefficient ({{S}}11) measurement, the frequency of the driving microwave power is scanned, which inevitably affects the plasma characters and leads to uncertainty in the estimated plasma impedance. In our proposed method, the frequency-scanning signal additional to the driving power is used to measure {{S}}11 over a wide frequency range, which enables accurate determination of the plasma impedance based on an equivalent circuit model. The measured resistance and reactance of the plasma increase with the driving power in agreement with the transmission line theory. Based on this in situ measurement of the plasma impedance, the net power coupled to the plasma has been determined. The overall power efficiency remains approximately unchanged around 45% for different input power levels owing to the competing effects between the impedance mismatch and the volume change of the plasma.

  20. Microwave Frequency Ferroelectric Domain Imaging of Deuterated Triglycine Sulfate Crystals

    Science.gov (United States)

    Steinhauer, David E.; Anlage, Steven M.

    2001-03-01

    We have used a near-field scanning microwave microscope(D. E. Steinhauer, C. P. Vlahacos, F. C. Wellstood, Steven M. Anlage, C. Canedy, R. Ramesh, A. Stanishevsky, and J. Melngailis, "Quantitative Imaging of Dielectric Permittivity and Tunability with a Near-Field Scanning Microwave Microscope," Rev. Sci. Instrum. 71), 2751-2758 (2000). to image domain structure and quantitatively measure dielectric permittivity and nonlinearity in ferroelectric crystals at 8.1 GHz with a spatial resolution of 1 μm. We imaged ferroelectric domains in periodically-poled LiNbO_3, BaTiO_3, and deuterated triglycine sulfate (DTGS) with a signal-to-noise ratio of 7. Measurement of the permittivity and nonlinearity of DTGS in the temperature range 300--400 K shows a peak at the Curie temperature, TC ≈ 340 K, as well as reasonable agreement with thermodynamic theory. In addition, the domain growth relaxation time shows a minimum near T_C. We observe coarsening of ferroelectric domains in DTGS after a temperature quench from 360 K to 330 K, and evaluate the structure factor.

  1. A comparative study of conventionally sintered and microwave sintered nickel zinc ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Rekha [Electroceramics Research Lab, GVM Girls College, Sonepat-131001, India and School of Physics and Materials Science, Thapar University, Patiala-147004 (India); Juneja, J. K. [Department of Physics, Hindu College, Sonepat-131001 (India); Raina, K. K. [School of Physics and Materials Science, Thapar University, Patiala-147004 (India); Kotnala, R. K. [National Physical Laboratory, New Delhi -110012 (India); Prakash, Chandra, E-mail: cprakash2014@gmail.com [Solid State Physics Laboratory, Timarpur, Delhi - 110054 (India)

    2014-04-24

    For the present work, nickel zinc ferrite having compositional formula Ni{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} was synthesized by conventional solid state method and sintered in conventional and microwave furnaces. Pellets were sintered with very short soaking time of 10 min at 1150 °C in microwave furnace whereas 4 hrs of soaking time was selected for conventional sintering at 1200 °C. Phase formation was confirmed by X-ray diffraction analysis technique. Scanning electron micrographs were taken for microstructural study. Dielectric properties were studied as a function of temperature. To study magnetic behavior, M-H hysteresis loops were recorded for both samples. It is observed that microwave sintered sample could obtain comparable properties to the conventionally sintered one in lesser soaking time at lower sintering temperature.

  2. Green synthesis of silver nanoparticles using extract of Parkia speciosa Hassk pods assisted by microwave irradiation

    Directory of Open Access Journals (Sweden)

    Is Fatimah

    2016-11-01

    Full Text Available This paper reports an investigation of the microwave-assisted synthesis of silver nanoparticles (Ag NPs using extract of stinky bean (Parkia speciosa Hassk pods (BP. The formation of Ag NPs was identified by instrumental analysis consists of UV–vis spectrophotometry, Fourier-transform infrared (FTIR spectrophotometry, scanning electron microscopy (SEM, transmission electron microscopy (TEM and particle size analysis. Furthermore, Ag NPs were used as antibacterial agents against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The results indicate rapid formation of Ag NPs during microwave irradiation with similar properties to those obtained through the aging method. In general, the use of microwave irradiation yields larger particles, and it is affected by volume ratio of the extract to the AgNO3 solution. The prepared materials demonstrated antibacterial activity.

  3. Synthesis and applications of poly(2-hydroxyethylmethacrylate) grafted agar: a microwave based approach.

    Science.gov (United States)

    Rani, G Usha; Mishra, Sumit; Pathak, Gopal; Jha, Usha; Sen, Gautam

    2013-10-01

    Synthesis of graft copolymers under the influence of microwave radiation alone is a rapid, efficient, clean, cheap, convenient, energy-saving and green method. Grafting of poly(2-hydroxyethylmethacrylate) on agar backbone was carried out under the influence of microwave radiation. The synthesis is optimized in terms of percentage grafting and intrinsic viscosity, by varying the microwave irradiation time and monomer (2-hydroxyethylmethacrylate) concentration. The synthesized graft copolymers have been characterized by intrinsic viscosity measurement, FTIR spectroscopy, UV-spectroscopy, elemental analysis (C, H, N, & S), thermal studies and scanning electron microscopy (SEM). Flocculation efficacy of the synthesized graft copolymers was studied in 0.25% kaolin and 1% coal fine suspension, through 'jar test' procedure. Further, flocculation efficacy of the best grade, coagulant (alum) and agar were studied for possible application in remediation of metals from river water.

  4. Microwave plasma-enhanced chemical vapour deposition growth of carbon nanostructures

    Directory of Open Access Journals (Sweden)

    Shivan R. Singh

    2010-05-01

    Full Text Available The effect of various input parameters on the production of carbon nanostructures using a simple microwave plasma-enhanced chemical vapour deposition technique has been investigated. The technique utilises a conventional microwave oven as the microwave energy source. The developed apparatus is inexpensive and easy to install and is suitable for use as a carbon nanostructure source for potential laboratory-based research of the bulk properties of carbon nanostructures. A result of this investigation is the reproducibility of specific nanostructures with the variation of input parameters, such as carbon-containing precursor and support gas flow rate. It was shown that the yield and quality of the carbon products is directly controlled by input parameters. Transmission electron microscopy and scanning electron microscopy were used to analyse the carbon products; these were found to be amorphous, nanotubes and onion-like nanostructures.

  5. Microwave-assisted brazing of alumina ceramics for electron tube applications

    Indian Academy of Sciences (India)

    2016-04-01

    Alumina was joined with alumina using microwave-assisted and conventional brazing methods at 960$^{\\circ}$C for 15 min using TiCuSil (68.8Ag–26.7Cu–4.5Ti in wt.%) as the brazing alloy. The brazed joints were characterizedby X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, Vickers microhardness evaluation, brazing strength measurement and helium leak test. X-ray diffraction analysis confirmed the formationof Ti-based compounds at the substrate-filler alloy interfaces of the microwave and conventionally brazed joints. The elemental compositions at the joint cross-section were determined by energy dispersive X-ray analysis. Vickers microhardness measurement indicated reliable joint performance for the microwave-assisted brazed joints during actual application in an electron tube. Brazing strength measurement and helium leak test provided the evidence forgood alumina-alumina joint formation.

  6. Synthesis and Characterization of Microwave Sintered Silica Xerogel Produced from Rice Husk Ash

    Science.gov (United States)

    Sudiana, I. N.; Mitsudo, S.; Nishiwaki, T.; Susilowati, P. E.; Lestari, L.; Firihu, M. Z.; Aripin, H.

    2016-08-01

    Silica xerogel ceramic produced from rice husk ash (RHA) taken from South East Sulawesi Indonesia has been successfully sintered by using a millimeter waves (MMW) heating system with a 28 GHz gyrotron as radiation source. The ceramic was also sintered by using an electric furnace where served as a comparison. Densification, microstructural, and morphological characterization of the silica were then investigated by using an Archimedes densification measurement method device, a X-ray diffraction (XRD) and a Scanning Electron Microscopy (SEM), respectively. Effect of microwave energy on the properties of silica xerogel ceramic were evaluated and discussed and compared to conventionally sintered results. The notably different densification and microstructure of sintered samples after sintering were found. The results suggest that microwave radiation provides a microwave effect during sintering.

  7. Microwave irradiation induced band gap tuning of MoS2-TiO2 nanocomposites

    Science.gov (United States)

    Shakya, Jyoti; Mohanty, T.

    2016-05-01

    The MoS2-TiO2 nanocomposites have been synthesized by sol-gel method and characterized by different microscopic and spectroscopic techniques. The crystallinity of these nanocomposites has been confirmed by X-ray diffraction (XRD) analysis. The Raman spectrum of MoS2-TiO2 nanocomposites consists of three distinct peaks (E1 g, E1 2g and A1g) which are associated with TiO2 and MoS2. The morphological study is carried out by scanning electron microscope. The effect of microwave irradiation on the band gap of MoS2-TiO2 nanocomposites has been investigated; it is observed that the microwave irradiation causes decrease in the band gap of MoS2-TiO2 nanocomposites. The microwave treated MoS2-TiO2 thin films offers a novel process route in treating thin films for commercial applications.

  8. Synthesis of multi-linked ZnO rods by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Kathalingam, A.; Chae, Y.S.; Rhee, J.K. [Millimeter-wave INnovation Technology research center MINT, Dongguk Univ., Seoul 100-715 (Korea, Republic of)

    2011-05-15

    Synthesis of linked ZnO micro rods by microwave radiation and its characterization is presented in this report. In this simple microwave assisted solution phase route zinc nitrate and hexamethylenetetramine has been used as the starting materials for the synthesis of linked ZnO rods. Linked ZnO rods with various morphologies such as bipods, tripods, tetrapods and etc have been prepared. The influence of irradiation time of microwave on the formation of linked ZnO rods was investigated. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS) were used for the characterization of the product. The FESEM images showed ZnO rods of diameter in the range of 100-200 nm and length around 5000 nm. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Preparation of activated carbon by microwave heating of langsat (Lansium domesticum) empty fruit bunch waste.

    Science.gov (United States)

    Foo, K Y; Hameed, B H

    2012-07-01

    The feasibility of langsat empty fruit bunch waste for preparation of activated carbon (EFBLAC) by microwave-induced activation was explored. Activation with NaOH at the IR ratio of 1.25, microwave power of 600 W for 6 min produced EFBLAC with a carbon yield of 81.31% and adsorption uptake for MB of 302.48 mg/g. Pore structural analysis, scanning electron microscopy and Fourier transform infrared spectroscopy demonstrated the physical and chemical characteristics of EFBLAC. Equilibrium data were best described by the Langmuir isotherm, with a monolayer adsorption capacity of 402.06 mg/g, and the adsorption kinetics was well fitted to the pseudo-second-order equation. The findings revealed the potential to prepare high quality activated carbon from langsat empty fruit bunch waste by microwave irradiation.

  10. Catalytic Methods in Asymmetric Synthesis Advanced Materials, Techniques, and Applications

    CERN Document Server

    Gruttadauria, Michelangelo

    2011-01-01

    This book covers advances in the methods of catalytic asymmetric synthesis and their applications. Coverage moves from new materials and technologies to homogeneous metal-free catalysts and homogeneous metal catalysts. The applications of several methodologies for the synthesis of biologically active molecules are discussed. Part I addresses recent advances in new materials and technologies such as supported catalysts, supports, self-supported catalysts, chiral ionic liquids, supercritical fluids, flow reactors and microwaves related to asymmetric catalysis. Part II covers advances and milesto

  11. Advances in nanosized zeolites

    Science.gov (United States)

    Mintova, Svetlana; Gilson, Jean-Pierre; Valtchev, Valentin

    2013-07-01

    This review highlights recent developments in the synthesis of nanosized zeolites. The strategies available for their preparation (organic-template assisted, organic-template free, and alternative procedures) are discussed. Major breakthroughs achieved by the so-called zeolite crystal engineering and encompass items such as mastering and using the physicochemical properties of the precursor synthesis gel/suspension, optimizing the use of silicon and aluminium precursor sources, the rational use of organic templates and structure-directing inorganic cations, and careful adjustment of synthesis conditions (temperature, pressure, time, heating processes from conventional to microwave and sonication) are addressed. An on-going broad and deep fundamental understanding of the crystallization process, explaining the influence of all variables of this complex set of reactions, underpins an even more rational design of nanosized zeolites with exceptional properties. Finally, the advantages and limitations of these methods are addressed with particular attention to their industrial prospects and utilization in existing and advanced applications.

  12. Gallium scans in myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Swick, H.M. (Univ. of Kentucky, Lexington); Preston, D.F.; McQuillen, M.P.

    1976-01-01

    A study was conducted to determine whether /sup 67/Ga scans could be used for the detection of thymomas and to investigate the activity of the thymus gland in patients with myasthenia gravis. Scans of the anterior mediastinum proved to be a reliable way to detect thymomas. The scans were positive in eight patients including three with myasthenia gravis and histologically proved thymomas, three others with severe myasthenia gravis and thymic tumors, and two with histologically proved thymomas not associated with myasthenia. Activity on /sup 67/Ga scans was not directly related to the increased activity of the thymus gland that is presumed to be associated with myasthenia gravis. (HLW)

  13. Effect of thickness on microwave absorptive behavior of La-Na doped Co-Zr barium hexaferrites in 18.0-26.5 GHz band

    Science.gov (United States)

    Arora, Amit; Narang, Sukhleen Bindra; Pubby, Kunal

    2017-02-01

    In this research, the microwave properties of Lanthanum-Sodium doped Cobalt-Zirconium barium hexaferrites, intended as microwave absorbers, are analyzed on Vector Network Analyzer in K-band. The results indicate that the doping has resulted in lowering of real permittivity and enhancement of dielectric losses. Real permeability has shown increase while magnetic losses have shown decrease in value with doping. All these four properties have shown very small variation with frequency in the scanned frequency range which indicates the relaxation type of behavior. Microwave absorption characteristics of these compositions are analyzed with change in sample thickness. The results demonstrate that the matching frequency of the microwave absorber shifts towards lower side of frequency band with increase in thickness. The complete analysis of the prepared microwave absorbers shows a striking achievement with very low reflection loss and wide absorption bandwidth for all the six compositions in 18-26.5 GHz frequency band.

  14. Aerodigestive Tract Burn from Ingestion of Microwaved Food

    Directory of Open Access Journals (Sweden)

    Michael Silberman

    2013-01-01

    Full Text Available Aerodigestive tract burns represent a rare but potentially devastating injury pattern throughout the world. Although the majority of these injuries do not require intervention, these burns have the potential for poor outcomes. Traditionally this disease has been caused by superheated gases found in explosions or fire-related injury. However, as technology advances, it brings novel methods for injury that require physician awareness of potential hazards. We describe a case of laryngeal and esophageal thermal burn caused by a microwave heated food bolus.

  15. Re-scan confocal microscopy: scanning twice for better resolution

    NARCIS (Netherlands)

    De Luca, G.M.R.; Breedijk, R.M.P.; Brandt, R.A.J.; Zeelenberg, C.H.C.; De Jong, B.E.; Timmermans, W.; Nahidi Azar, L.; Hoebe, R.A.; Stallinga, S.; Manders, E.M.M.

    2013-01-01

    We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity wh

  16. Re-scan confocal microscopy : scanning twice for better resolution

    NARCIS (Netherlands)

    De Luca, G.M.R.; Breedijk, R.M.P.; Brandt, R.A.J.; Zeelenberg, C.H.C.; de Jong, B.E.; Timmermans, W.; Azar, L.N.; Hoebe, R.A.; Stallinga, S.; Manders, E.M.M.

    2013-01-01

    We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity wh

  17. Delivering Microwave Spectroscopy to the Masses: a Design of a Low-Cost Microwave Spectrometer Operating in the 18-26 GHZ Frequency Range

    Science.gov (United States)

    Steber, Amanda; Pate, Brooks

    2014-06-01

    Advances in chip-level microwave technology in the communications field have led to the possibilities of low cost alternatives for current Fourier transform microwave (FTMW) spectrometers. Many of the large, expensive microwave components in a traditional design can now be replaced by robust, mass market monolithic microwave integrated circuits (MMICs). "Spectrometer on a board" designs are now feasible that offer dramatic cost reduction for microwave spectroscopy. These chip-level components can be paired with miniature computers to produce compact instruments that are operable through USB. A FTMW spectrometer design using the key MMIC components that drive cost reduction will be presented. Two dual channel synthesizers (Valon Technology Model 5008), a digital pattern generator (Byte Paradigm Wav Gen Xpress), and a high-speed digitizer/arbitrary waveform generator combination unit (Tie Pie HS-5 530 XM) form the key components of the spectrometer for operation in the 18-26.5 GHz range. The design performance is illustrated using a spectrometer that is being incorporated into a museum display for astrochemistry. For this instrument a user interface, developed in Python, has been developed and will be shown.

  18. Scanning tunneling microscopy II further applications and related scanning techniques

    CERN Document Server

    Güntherodt, Hans-Joachim

    1992-01-01

    Scanning Tunneling Microscopy II, like its predecessor, presents detailed and comprehensive accounts of the basic principles and broad range of applications of STM and related scanning probe techniques. The applications discussed in this volume come predominantly from the fields of electrochemistry and biology. In contrast to those described in Vol. I, these sudies may be performed in air and in liquids. The extensions of the basic technique to map other interactions are described inchapters on scanning force microscopy, magnetic force microscopy, scanning near-field optical microscopy, together with a survey of other related techniques. Also described here is the use of a scanning proximal probe for surface modification. Togehter, the two volumes give a comprehensive account of experimental aspcets of STM. They provide essentialreading and reference material for all students and researchers involvedin this field.

  19. Scanning tunneling microscopy II further applications and related scanning techniques

    CERN Document Server

    Güntherodt, Hans-Joachim

    1995-01-01

    Scanning Tunneling Microscopy II, like its predecessor, presents detailed and comprehensive accounts of the basic principles and broad range of applications of STM and related scanning probe techniques. The applications discussed in this volume come predominantly from the fields of electrochemistry and biology. In contrast to those described in STM I, these studies may be performed in air and in liquids. The extensions of the basic technique to map other interactions are described in chapters on scanning force microscopy, magnetic force microscopy, and scanning near-field optical microscopy, together with a survey of other related techniques. Also described here is the use of a scanning proximal probe for surface modification. Together, the two volumes give a comprehensive account of experimental aspects of STM. They provide essential reading and reference material for all students and researchers involved in this field. In this second edition the text has been updated and new methods are discussed.

  20. Design and realisation of a microwave three-dimensional imaging system with application to breast-cancer detection

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, T.; Krozer, V.

    2010-01-01

    An active microwave-imaging system for non-invasive detection of breast cancer based on dedicated hardware is described. Thirty-two transceiving channels are used to measure the amplitude and phase of the scattered fields in the three-dimensional (3D) imaging domain using electronic scanning. The 3...