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Sample records for antenna diagnostics technique

  1. Modern antenna measurements and diagnostics including phaseless techniques

    OpenAIRE

    Rahmat-Samii, Yahya; Yaccarino, R. G.

    1997-01-01

    Microwave antenna imaging techniques are a practical and popular method for antenna diagnostic analysis. Phase retrieval methods, however, are just beginning to emerge as an alternative mircowave antenna measurements technique when phase cannot be directly measured. This article focuses on recent advances in microwave antenna imaging, diagnostic techniques, and phase retrieval methods for bi-polar planar near-field antenna measurements. An overview of the bi-polar planar near-field technique ...

  2. Application of the SWE-to-PWE antenna diagnostics technique to an offset reflector antenna

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Frandsen, A; Breinbjerg, Olav

    2007-01-01

    measurement accuracy, have been reported previously, we validate here the new antenna diagnostics technique through an experimental investigation of a commercially available offset reflector antenna, where a tilt of the feed and surface distortions are intentionally introduced. The effects of these errors......A new antenna diagnostics technique has been developed for the DTU-ESA Spherical Near-Field Antenna Test Facility at the Technical University of Denmark. The technique is based on the transformation of the Spherical Wave Expansion (SWE) of the radiated field, obtained from a spherical near...... will be detected in the antenna far-field pattern, and the accuracy and ability of the diagnostics technique to subsequently identify them will be investigated. Real measurement data will be employed for each test case....

  3. Application of the SWE-to-PWE antenna diagnostics technique to an offset reflector antenna

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Frandsen, Aksel; Breinbjerg, Olav

    2008-01-01

    Electrical and mechanical errors in an antenna may seriously affect the antenna's performance. Although their presence is usually detected by anomalies in the antenna's far-field pattern, their identification is normally possible only through an analysis of the antenna's extreme near field. The...... reconstruction of the extreme near field on the basis of near- or far-field measurements is thus an essential step in antenna diagnostics....

  4. The influence on finite measurement accuracy on the SWE-to-PWE antenna diagnostics technique

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Breinbjerg, Olav; Frandsen, Aksel

    2006-01-01

    A new antenna diagnostics technique based on the transformation of the spherical wave expansion (SWE) into the plane wave expansion (PWE) is proposed. The new technique allows the recovery of the plane wave spectrum in the visible region, and in principle also in part of the invisible region, fro...... this diagnostics technique. In order to isolate different measurement inaccuracies, the investigation is based on simulations.......A new antenna diagnostics technique based on the transformation of the spherical wave expansion (SWE) into the plane wave expansion (PWE) is proposed. The new technique allows the recovery of the plane wave spectrum in the visible region, and in principle also in part of the invisible region, from...

  5. A High-Resolution Antenna Diagnostics Technique for Spherical Nesr-Field Measurements

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Breinbjerg, Olav; Frandsen, Aksel

    A new diagnostics technique for spherical near-field antenna measurements, that can provide a high spatial resolution of the reconstructed aperture field, is presented. This technique is realized by transforming the spherical wave expansion (SWE) of the radiated field into the corresponding plane...... wave expansion (PWE), recovering a significant part of the invisible region of the plane wave spectrum. Through the inverse Fourier transform (IFT), the field on a plane outside as well as inside the antenna minimum sphere is reconstructed, with a resolution that exceeds the limit of one half a...... wavelength provided by the traditional IFT of the far-field....

  6. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  7. Diagnostics of the SMOS radiometer antenna system at the DTU-ESA spherical near-field antenna test facility

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Frandsen, A.; Pivnenko, Sergey; Lemanczyk, G.; Breinbjerg, Olav

    2007-01-01

    The recently developed Spherical Wave Expansion-to-Plane Wave Expansion (SWE-to-PWE) antenna diagnostics technique is employed in an investigation of the antenna system in the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS) for ESA’s Soil Moisture and Ocean Salinity (SMOS) mission....... The SWE-to-PWE antenna diagnostics technique successfully identifies the sources of the anomalies detected in 2 of the 138 MIRAS antenna farfield patterns that were measured during the on-ground calibration at the DTU-ESA Spherical Near-Field Antenna Test Facility in 2006. In addition to its obvious...... value for the SMOS mission, this investigation also provides an experimental validation of the SWE-to-PWE antenna diagnostics technique....

  8. 60 GHz Antenna Diagnostics from Planar Near Field Antenna Measurement Without External Frequency Conversion

    DEFF Research Database (Denmark)

    Popa, Paula Irina; Pivnenko, Sergey; Breinbjerg, Olav

    2015-01-01

    antenna diagnostics and perform a detailed systematic study of the extreme near-field of a standard gain horn at 60GHz from planar and spherical near-field measurement data. The magnitude and phase of all three rectangular components of the electric and the magnetic aperture fields are calculated, as is......We previously demonstrated that 60 GHz planarnear-field antenna measurements without external frequency conversion can provide far-field radiation patterns in good agreement with spherical near-field antenna measurements in spite of thecable flexing and thermal drift effects [P.I.Popa, S. Pivnenko......,J.M. Nielsen, O. Breinbjerg, 60 GHz Antenna Measurement Setup using a VNA without External Frequency Conversion,36th Annual Symposium of the Antenna Measurement Technique Association ,October 12-17,Tucson, Arizona, 2014]. In this work we extend the validation of this 60 GHz planar near-field (PNF) set-up to...

  9. Microscale diagnostic techniques

    CERN Document Server

    Breuer, Kenny

    2005-01-01

    Microscale Diagnostic Techniques highlights the most innovative and powerful developments in microscale diagnostics. It provides a resource for scientists and researchers interested in learning about the techniques themselves, including their capabilities and limitations. The fields of Micro- and Nanotechnology have emerged over the past decade as a major focus of modern scientific and engineering research and technology. Driven by advances in microfabrication, the investigation, manipulation and engineering of systems characterized by micrometer and, more recently, nanometer scales have becom

  10. Fast cooling techniques for gravitational wave antennas

    CERN Document Server

    Furtado, S R

    2002-01-01

    The resonant-mass technique for the detection of gravitational waves may involve, in the near future, the cooling of very large masses (about 100 tons) from room temperature (300 K) to extreme cryogenic temperatures (20 mK). To cool these detectors to cryogenic temperatures an exchange gas (helium) is used, and the heat is removed from the antenna to the cold reservoir by thermal conduction and natural convection. With the current technique, cooling times of about 1 month can be obtained for cylindrical bar antennas of 2.5 tons. Should this same technique be used to cool a 100 ton spherical antenna the cooling time would be about 10 months, making the operation of these antennas impracticable. In this paper, we study the above-mentioned cooling technique and others, such as thermal switching and forced convection from room temperature to liquid nitrogen temperature (77 K) using an aluminium truncated icosahedron of 19 kg weight and 25 cm diameter.

  11. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2001-01-01

    This book gives an introduction to the possibilities of radar technology based on active array antennas, giving examples of modern practical systems. There are many valuable lessons presented for designers of future high standard multifunction radar systems for military and civil applications. The book will appeal to graduate level engineers, researchers, and managers in the field of radar, aviation and space technology.

  12. Bandwidth Enhancement Techniques of Dielectric Resonator Antenna

    Directory of Open Access Journals (Sweden)

    ARCHANA SHARMA

    2011-07-01

    Full Text Available The paper briefly reviews the historical background of dielectric resonator antenna and its bandwidth enhancement techniques. The main focus is on a compact DRA that can offer broad band operation. It has been illustrated that dual resonance and multi resonance operation can be much effective to give wide band characteristics of DRA.

  13. Technique for Radiometer and Antenna Array Calibration with Two Antenna Noise Diodes

    Science.gov (United States)

    Srinivasan, Karthik; Limaye, Ashutosh; Laymon, Charles; Meyer, Paul

    2011-01-01

    This paper presents a new technique to calibrate a microwave radiometer and phased array antenna system. This calibration technique uses a radiated noise source in addition to an injected noise sources for calibration. The plane of reference for this calibration technique is the face of the antenna and therefore can effectively calibration the gain fluctuations in the active phased array antennas. This paper gives the mathematical formulation for the technique and discusses the improvements brought by the method over the existing calibration techniques.

  14. A Miniaturization Technique of a Compact Omnidirectional Antenna

    Directory of Open Access Journals (Sweden)

    C. Delaveaud

    2009-12-01

    Full Text Available This paper discusses a miniaturization technique of a compact omnidirectional antenna. A slot loading technique is applied to a well-known low-profile antenna structure whose radiation characteristics are similar to equivalent monopole ones. An equivalent circuit which models the antenna input impedance including the slot effect is also developed in order to illustrate the antenna working principle. The typical dimensions (width x height of the obtained antenna are λ0/11 x λ0/75 (λ0 is the free space operating wavelength which makes it a miniature antenna that can be integrated inside small wireless sensor nodes using narrow band communication systems. Its performances are in accordance with classical fundamental limits, the operating bandwidth and efficiency are significantly reduced with the antenna size reduction.

  15. 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)

  16. Measurement techniques for millimeter wave substrate mounted MMW antennas

    Science.gov (United States)

    Gouker, M. A.; Campbell, D. P.; Gallagher, J. J.

    1986-01-01

    An overview of measurement techniques for millimeter wave substrate mounted antennas is presented. Scattering and pickup of the millimeter wave radiation on the low frequency leads is a significant problem in these measurements. Methods to reduce these effects are discussed, and preliminary work on dipole antennas at 230 GHz is presented.

  17. Extraordinary transmission technique for microwave antenna applications

    Science.gov (United States)

    Sarin, V. P.; Jayakrishnan, M. P.; Aanandan, C. K.; Mohanan, P.; Vasudevan, K.

    2016-05-01

    The extraordinary optical transmission (EOT) through an array of holes in a metal plate has been a constant source of inspiration for researchers for over a decade (Ebbesen et al 1998 Nature 391 667–9). In this paper, an EOT analogue is proposed in the microwave frequency range for enhancing the radiation performance of a stacked dipole antenna. It is observed that the back radiated power of the antenna is considerably reduced and the reason behind transmission enhancement is the excitation of Fabry–Pérot resonant modes on the slit loaded aperture. Computational analysis based on finite difference time domain is performed for identifying the true reason behind resonant transmission enhancement.

  18. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics.

    Science.gov (United States)

    Kuwahara, D; Ito, N; Nagayama, Y; Yoshinaga, T; Yamaguchi, S; Yoshikawa, M; Kohagura, J; Sugito, S; Kogi, Y; Mase, A

    2014-11-01

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array. PMID:25430218

  19. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Kuwahara, D., E-mail: dkuwahar@cc.tuat.ac.jp [Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Ito, N. [Department of Intelligent System Engineering, Ube National College of Technology, Ube, Yamaguchi 755-8555 (Japan); Nagayama, Y. [Department of Helical Plasma Research, National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Yoshinaga, T. [Department of Applied Physics, National Defense Academy, Yokosuka, Kanagawa 239-0811 (Japan); Yamaguchi, S. [Department of Pure and Applied Physics, Kansai University, Suita, Osaka 564-8680 (Japan); Yoshikawa, M.; Kohagura, J. [Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Sugito, S. [Equipment Development Center, Institute for Molecular Science, Okazaki, Aichi 444-8585 (Japan); Kogi, Y. [Department of Information Electronics, Fukuoka Institute of Technology, Fukuoka, Fukuoka 811-0295 (Japan); Mase, A. [Art, Science and Technology Center for Cooperative Research, Kyusyu University, Kasuga, Fukuoka 816-8580 (Japan)

    2014-11-15

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array.

  20. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    International Nuclear Information System (INIS)

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array

  1. Imaging techniques in thyroid diagnostics

    International Nuclear Information System (INIS)

    Imaging techniques were discussed in a comprehensive manner and in consideration of the rapid recent progress. 30 papers were presented on the subjects of, roughly, radiology, nuclear medicine, and sonography. Apart from conventional radiodiagnostics, which may even yield epidemiological information, the first section also discussed pneumatological functional analysis as a mean of diagnosing tracheal insufficiencies. Thyroid CT is the method of choice in the mediastinal manifestations of thyroid diseases and in examinations of the organs next to the thyroid. Orbital CT yields completely new findings on the pathophysiology, differential diagnosis and therapy of endocrineous orbitopathy. - While the diagnostic value of nuclear spin tomography remains uncertain, thyroid scintiscanning has reached maturity by now. In contrast to scanners, which give a general image, the γ camera can detect regional functional phenomena. Fluorescence scintiscanning, apart from quantification of intrathyroid iodine, enables scintigraphic imaging of the thyroid without incorporation of radioactivity. - The recent progress in thyroid sonography has been dramatic. Apart from the simple and reproducible technique of volumetry, nonstandard echo structures indicate diffuse or focal fine tissue lesions, and sonography has therefore become an accepted technique prior to fine needle biopsy or scintiscanning. (orig.)

  2. 2D Active Antenna Array Design for FD-MIMO System and Antenna Virtualization Techniques

    Directory of Open Access Journals (Sweden)

    Ioannis Tzanidis

    2015-01-01

    Full Text Available Full dimension MIMO (FD-MIMO is one of the key technologies presently studied in the 3GPP for the next generation long-term evolution advanced (LTE-A systems. By incorporating FD-MIMO into LTE/LTE-A systems, it is expected that system throughput will be drastically improved beyond what is possible in conventional LTE systems. This paper presets details on the 2D active antenna array design for FD-MIMO systems supporting 32 antenna elements. The FD-MIMO system allows for dynamic and adaptive precoding to be performed jointly across all antennas thus achieving more directional transmissions in the azimuth and elevation domains simultaneously, to a larger number of users. Finally, we discuss 2D antenna array port virtualization techniques for creating beams with wide coverage, necessary for broadcasting signals to all users within a sector, such as the CRS (Common Reference Signal.

  3. Advanced spherical near-field antenna measurement techniques

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Majlund; Pivnenko, Sergey; Breinbjerg, Olav

    2011-01-01

    The DTU-ESA facility has since the 1980es provided highly accurate antenna radiation pattern measurements and gain calibration by use of the probe corrected spherical nearfield technique, both for ESA (the European Space Agency) and other customers and continues to do so. Recent years activities...... and research carried out at the facility are presented in the article. Since 2004 several antenna test facility comparison campaigns were carried out between a number of European antenna measurement facilities. The first campaigns laid the foundation for the later comparisons in providing experience...... and showing the capabilities of each participating facility. A special campaign was carried out with the aim of establishing a reference radiation pattern for the DTU-ESA VAST-12 antenna. The on-ground calibration of the MIRAS space radiometer for ESA's SMOS mission was carried out at the DTU...

  4. Diagnostic techniques for measurement of aerodynamic noise in free field and reverberant environment of wind tunnels

    Science.gov (United States)

    El-Sum, H. M. A.; Mawardi, O. K.

    1973-01-01

    Techniques for studying aerodynamic noise generating mechanisms without disturbing the flow in a free field, and in the reverberation environment of the ARC wind tunnel were investigated along with the design and testing of an acoustic antenna with an electronic steering control. The acoustic characteristics of turbojet as a noise source, detection of direct sound from a source in a reverberant background, optical diagnostic methods, and the design characteristics of a high directivity acoustic antenna. Recommendations for further studies are included.

  5. Imaging Techniques for Microwave Diagnostics

    NARCIS (Netherlands)

    Tobias, B.; Donne, A. J. H.; Park, H. K.; Boom, J. E.; Choi, M. J.; Classen, I.G.J.; Domier, C.W.; Kong, X.; Lee, W.; Liang, T.; N C Luhmann Jr.,; Munsat, T.; Yu, L.; Yun, G. S.

    2011-01-01

    Imaging diagnostics, such as Electron Cyclotron Emission Imaging (ECEI) and Microwave Imaging Reflectometry (MIR), exhibit unique characteristics that make them particularly well suited to the validation of theoretical models for plasma instabilities and turbulent fluctuations. A 2-D picture of plas

  6. Performance enhancement of implantable medical antenna using differential feed technique

    Directory of Open Access Journals (Sweden)

    Shankar Bhattacharjee

    2016-03-01

    Full Text Available The health care industry is continuously revolutionizing and advancing towards developing more efficient system suitable for human body. Today implantable devices have become a more interesting topic in health care services which primarily started with the pacemakers. Since then it is continuously evolving due to its non-invasive nature, instant monitoring and diagnosis, and periodic simulation. The main goal of these implantable devices is to efficiently monitor or inspect various ailments in the body and then transmits this to the server or base station. For proper communication between the implant and the base station, antenna design is of prime importance. In this paper MEMS based differentially fed dual band antenna has been proposed and can be used both in Medical Implant Communication Service (MICS band for transmission of data and industrial, scientific and medical (ISM band for wake-up purpose. The proposed antenna has been simulated for free space scenario and has been found to radiate in both MICS & ISM band with S11 of −17.62 dB and −14.31 dB respectively. Subsequently the antenna is inserted within a skin mimicking model with equivalent dielectric features and the results show variation in radiation characteristics between free space condition and within skin phantom. The design of the antenna has been optimized in such a way that minimum deviation occurs between the two conformal conditions. With the use of differential feeding technique performance of the antenna is quite enhanced in terms of various parameters when compared with single feed.

  7. Imaging antenna array at 119 microns. [for plasma diagnostics

    Science.gov (United States)

    Neikirk, N. P.; Tong, P. P.; Putledge, D. B.; Park, H.; Young, P. E.

    1982-01-01

    A focal-plane imaging antenna array has been demonstrated at 119 microns. The array is a line of evaporated silver bow-tie antennas with bismuth microbolometer detectors on a silicon substrate. Radiation is coupled into the array by a lens placed on the back of the substrate. The bolometers are thermally isolated from the silicon substrate with a half-micron layer of polyimide. The array performance is demonstrated by coherent imaging of a series of holes at half the diffraction-limited cut-off frequency.

  8. Array antenna diagnostics with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Meincke, Peter; Pivnenko, Sergey; Jørgensen, Erik

    The 3D reconstruction algorithm is applied to a slotted waveguide array measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. One slot of the array is covered by conductive tape and an error is present in the array excitation. Results show the accuracy obtainable by the 3D reconstru......The 3D reconstruction algorithm is applied to a slotted waveguide array measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. One slot of the array is covered by conductive tape and an error is present in the array excitation. Results show the accuracy obtainable by the 3D...

  9. Multi Antenna Techniques for Digital Video Broadcasting (DVB) Systems

    OpenAIRE

    Vargas Paredero, David Eduardo; Gozálvez Serrano, David; Gómez Barquero, David; Cardona Marcet, Narciso

    2012-01-01

    In this paper we describe the potential of multi-antenna techniques (MIMO) in the context of digital video broadcasting (DVB) systems. DVB standards have been challenged by the increasing demand of high data rate applications and larger indoor coverage area. MIMO is a key technology to increase the system capacity and link reliability without any additional bandwidth or transmit signal power. The Mobile Communications Group of iTEAM research institute has been actively...

  10. Microwave probe diagnostic for the lower hybrid multijunction antenna on TdeV

    International Nuclear Information System (INIS)

    On the TdeV tokamak a microwave probe diagnostic enables direct measurement of the electromagnetic fields in ten reduced waveguides of the lower hybrid current drive multijunction antenna. In each instrumented reduced waveguide, the local field is measured at two different locations by probes through coupling holes located in the narrow wall of the waveguides. The amplitude and phase of the signals are measured with a multichannel heterodyne circuit and are used to calculate the incident and reflected fields at the antenna mouth. The probes are under vacuum and they are bakeable up to the maximum operating temperature of the antenna (T=350 degree C). They are calibrated at room temperature but the evolution of their characteristic with temperature is taken into account in the data analysis. Typical accuracies of the field measurements at the grill mouth are: ±9% for the amplitude and ±6 degree for the phase. The probe diagnostic has been operating reliably for the last two years and the probes do not appear to perturb the operation of the antenna nor to reduce its power handling capability. Comparisons of the probe measurements with calculations from the multijunction antenna modeling code SWAN show that the code is accurate for low rf power densities at the antenna mouth. copyright 1997 American Institute of Physics

  11. Progress in diagnostic techniques for sc cavities

    International Nuclear Information System (INIS)

    While routinely achieved performance characteristics of superconducting cavities have now reached a level which makes them useful in large scale applications, achieving this level has come only through the knowledge gained by systematic studies of performance limiting phenomena. Despite the very real progress that has been made, the routine performance of superconducting cavities still falls far short of both the theoretical expectations and the performance of a few exception examples. It is the task of systematically applied diagnostic techniques to reveal additional information concerning the response of superconducting surfaces to applied RF fields. Here recent developments in diagnostic techniques are discussed. 18 references, 12 figures

  12. A cable-free impedance and gain measurement technique for electrically small antennas

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Zhang, Jiaying; Breinbjerg, Olav

    2010-01-01

    Impedance and gain measurements for electrically small antennas represent a great challenge due to influences of the feeding cable. The leaking current along the cable and scattering effects are two main issues caused by the feed line. In this paper, a novel cable-free antenna impedance and gain...... measurement technique for electrically small antennas is proposed. The antenna properties are extracted by measuring the signal scattered by the antenna under test (AUT), when it is loaded with three known loads. The technique is based on a rigorous electromagnetic model where the probe and AUT are...... represented in terms of spherical wave expansions (SWEs), and the propagation is accounted for by a transmission formula. In this paper the measurement results by the proposed technique will be presented for several AUTs, including a standard gain horn antenna, a monopole antenna, and an electrically small...

  13. Rocket engine diagnostics using qualitative modeling techniques

    Science.gov (United States)

    Binder, Michael; Maul, William; Meyer, Claudia; Sovie, Amy

    1992-01-01

    Researchers at NASA Lewis Research Center are presently developing qualitative modeling techniques for automated rocket engine diagnostics. A qualitative model of a turbopump interpropellant seal system has been created. The qualitative model describes the effects of seal failures on the system steady-state behavior. This model is able to diagnose the failure of particular seals in the system based on anomalous temperature and pressure values. The anomalous values input to the qualitative model are generated using numerical simulations. Diagnostic test cases include both single and multiple seal failures.

  14. Diagnostic imaging techniques for urological examinations

    International Nuclear Information System (INIS)

    The introduction briefly reviews fundamentals, methodology and techniques of conventional X-ray diagnostics, ultrasonic scanning, and CT. The following chapters, placed under the leading title 'Specialized diagnostics', deal with the urogenital system and the neighbouring body areas and are arranged by specific organs. The urogenital system diseases are presented by keywords in tabular form, and the radiomorphological criteria are explained, supported by numerous graphical representations. The text parts are supplemented by an evaluative analysis of the various diagnostic methods and by information on best suitable applications of the methods. There also is an extensive collection of illustrations that round up the information presented to a complete and exhaustive survey. (orig./MG) With 3 tabs., 400 figs

  15. Bandwidth Enhancement Technique of the Meandered Monopole Antenna

    OpenAIRE

    Chien-Jen Wang; Dai-Heng Hsieh

    2015-01-01

    A small dual-band monopole antenna with coplanar waveguide (CPW) feeding structure is presented in this paper. The antenna is composed of a meandered monopole, an extended conductor tail, and an asymmetrical ground plane. Tuning geometrical structure of the ground plane excites an additional resonant frequency band and thus enhances the impedance bandwidth of the meandered monopole antenna. Unlike the conventional monopole antenna, the new resonant mode is excited by a slot trace of the CPW t...

  16. Autofluorescence based diagnostic techniques for oral cancer

    OpenAIRE

    Balasubramaniam, A. Murali; Sriraman, Rajkumari; Sindhuja, P; Mohideen, Khadijah; Parameswar, R. Arjun; Muhamed Haris, K. T.

    2015-01-01

    Oral cancer is one of the most common cancers worldwide. Despite of various advancements in the treatment modalities, oral cancer mortalities are more, particularly in developing countries like India. This is mainly due to the delay in diagnosis of oral cancer. Delay in diagnosis greatly reduces prognosis of the treatment and also cause increased morbidity and mortality rates. Early diagnosis plays a key role in effective management of oral cancer. A rapid diagnostic technique can greatly aid...

  17. Development of local oscillator integrated antenna array for microwave imaging diagnostics

    International Nuclear Information System (INIS)

    Microwave imaging diagnostics are powerful tools that are used to obtain details of complex structures and behaviors of such systems as magnetically confined plasmas. For example, microwave imaging reflectometry and microwave imaging interferometers are suitable for observing phenomena that are involved with electron density fluctuations; moreover, electron cyclotron emission imaging diagnostics enable us to accomplish the significant task of observing MHD instabilities in large tokamaks. However, microwave imaging systems include difficulties in terms of multi-channelization and cost. Recently, we solved these problems by developing a Horn-antenna Mixer Array (HMA), a 50 - 110 GHz 1-D heterodyne- type antenna array, which can be easily stacked as a 2-D receiving array, because it uses an end-fire element. However, the HMA still evidenced problems owing to the requirement for local oscillation (LO) optics and an expensive high-power LO source. To solve this problem, we have developed an upgraded HMA, named the Local Integrated Antenna array (LIA), in which each channel has an internal LO supply using a frequency multiplier integrated circuit. Therefore, the proposed antenna array eliminates the need for both the LO optics and the high-power LO source. This paper describes the principle of the LIA, and provides details about an 8 channel prototype LIA

  18. Development of local oscillator integrated antenna array for microwave imaging diagnostics

    Science.gov (United States)

    Kuwahara, D.; Ito, N.; Nagayama, Y.; Tsuchiya, H.; Yoshikawa, M.; Kohagura, J.; Yoshinaga, T.; Yamaguchi, S.; Kogi, Y.; Mase, A.; Shinohara, S.

    2015-12-01

    Microwave imaging diagnostics are powerful tools that are used to obtain details of complex structures and behaviors of such systems as magnetically confined plasmas. For example, microwave imaging reflectometry and microwave imaging interferometers are suitable for observing phenomena that are involved with electron density fluctuations; moreover, electron cyclotron emission imaging diagnostics enable us to accomplish the significant task of observing MHD instabilities in large tokamaks. However, microwave imaging systems include difficulties in terms of multi-channelization and cost. Recently, we solved these problems by developing a Horn-antenna Mixer Array (HMA), a 50 - 110 GHz 1-D heterodyne- type antenna array, which can be easily stacked as a 2-D receiving array, because it uses an end-fire element. However, the HMA still evidenced problems owing to the requirement for local oscillation (LO) optics and an expensive high-power LO source. To solve this problem, we have developed an upgraded HMA, named the Local Integrated Antenna array (LIA), in which each channel has an internal LO supply using a frequency multiplier integrated circuit. Therefore, the proposed antenna array eliminates the need for both the LO optics and the high-power LO source. This paper describes the principle of the LIA, and provides details about an 8 channel prototype LIA.

  19. Diagnostics of nonlocal plasmas: advanced techniques

    Science.gov (United States)

    Mustafaev, Alexander; Grabovskiy, Artiom; Strakhova, Anastasiya; Soukhomlinov, Vladimir

    2014-10-01

    This talk generalizes our recent results, obtained in different directions of plasma diagnostics. First-method of flat single-sided probe, based on expansion of the electron velocity distribution function (EVDF) in series of Legendre polynomials. It will be demonstrated, that flat probe, oriented under different angles with respect to the discharge axis, allow to determine full EVDF in nonlocal plasmas. It is also shown, that cylindrical probe is unable to determine full EVDF. We propose the solution of this problem by combined using the kinetic Boltzmann equation and experimental probe data. Second-magnetic diagnostics. This method is implemented in knudsen diode with surface ionization of atoms (KDSI) and based on measurements of the magnetic characteristics of the KDSI in presence of transverse magnetic field. Using magnetic diagnostics we can investigate the wide range of plasma processes: from scattering cross-sections of electrons to plasma-surface interactions. Third-noncontact diagnostics method for direct measurements of EVDF in remote plasma objects by combination of the flat single-sided probe technique and magnetic polarization Hanley method.

  20. A wave matrix technique for analysis of lossy antenna array noise

    OpenAIRE

    Tokarsky, Peter L.

    1997-01-01

    A universal technique is proposed for the analysis of the noise temperature of an arbitrary phased antenna array allowing to estimate the contribution of all the sources of internal noises under rigorous taking into account of the mutual coupling between loss radiators. The technique is based on the matrix theory of antenna arrays [1, 2] and noisy microwave multiport circuits theory [3, 4].

  1. Hyperband Bi-Conical Antenna Design Using 3D Printing Technique

    Science.gov (United States)

    Andriambeloson, J. A.; Wiid, P. G.

    2016-03-01

    We combined a 3D printing technique with conductive paint for an antenna manufacturing methodology. The performance of the approach is evaluated through a 3D- printed and coated bi-cone antenna. The antenna far-field pattern and efficiency are measured using near-field spherical scan and reverberation chamber techniques. Good agreement is seen between measurements and simulations and an impedance bandwidth of at least 34:1 is achieved. An extruded bi-conical antenna geometry is also studied for bandwidth extension to lower frequency and an impedance bandwidth of 58:1 is realised.

  2. Wideband Planar U-shaped Monopole Antenna with Meandering Technique for TV White Space Application

    OpenAIRE

    Jamaluddin, M. H.; T. A. Rahman; H. Mohamad; Ramli, N; Islam, M. T.

    2013-01-01

    A novel wideband planar U-shaped antenna with meandering technique is proposed for TV White Space operation at 470 -798 MHz band. The antenna consists of a U-shaped antenna backed by a partial ground plane. The meandering technique is applied by inserting several slots at the bottom part of the U-shaped for bandwidth enhancement. An impedance bandwidth of 95.2% is achieved when the planar U-shaped antenna is added with 21 slots. The radiation pattern confirms that a good pattern stability are...

  3. Dental diagnostics using optical coherence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Nathel, H. [Lawrence Livermore National Lab., CA (United States); Colston, B. [Univ. of California, San Francisco, CA (United States); Armitage, G. [Univ. of California, Davis, CA (United States)] [and others

    1994-11-15

    Optical radiation can be used for diagnostic purposes in oral medicine. However, due to the turbid, amorphous, and inhomogeneous nature of dental tissue conventional techniques used to transilluminate materials are not well suited to dental tissues. Optical coherence techniques either in the time- of frequency-domain offer the capabilities of discriminating scattered from unscattered light, thus allowing for imaging through turbid tissue. Currently, using optical time-domain reflectometry we are able to discriminate specular from diffuse reflections occurring at tissue boundaries. We have determined the specular reflectivity of enamel and dentin to be approximately 6.6 x 10{sup -5} and 1.3 x 10{sup -6}, respectively. Implications to periodontal imaging will be discussed.

  4. Odd-order probe correction technique for spherical near-field antenna measurements

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey; Breinbjerg, Olav

    2005-01-01

    In this paper, an odd-order probe for spherical near-field antenna measurements is defined. A probe correction technique for odd-order probes is then formulated and tested by computer simulations. The probe correction for odd-order probes is important, since a wide range of realistic antennas...

  5. Diagnostic techniques: their strengths and weaknesses

    International Nuclear Information System (INIS)

    The diagnostic techniques available for estimating tumour volume in patients are reviewed, using tumours in the lungs and lymph nodes to illustrate the advantages and disadvantages. Tumour growth in lymph nodes is very difficult to assess using lymphography but useful information has been obtained in highly selected patients. The introduction of ultrasound and computed tomography (CT) have provided a method of assessing tumour size once it has broken out beyond the confines of the node. In general, CT appears to be the most accurate method of estimating tumour regression and growth of abdominal tumour at the present time. Physical imaging techniques have been used in various other sites for estimating tumour volume but the main advantages and disadvantages of conventional radiology, ultrasound and CT have been illustrated. Isotope scanning and thermography have not been widely used to quantify tumour volume because other techniques provide better delineation of the tumour margin which is the most important factor. However, even the most accurate methods available today are still dependent on subjective visual assessment. (author)

  6. Novel On-Wafer Radiation Pattern Measurement Technique for MEMS Actuator Based Reconfigurable Patch Antennas

    Science.gov (United States)

    Simons, Rainee N.

    2002-10-01

    The paper presents a novel on-wafer, antenna far field pattern measurement technique for microelectromechanical systems (MEMS) based reconfigurable patch antennas. The measurement technique significantly reduces the time and the cost associated with the characterization of printed antennas, fabricated on a semiconductor wafer or dielectric substrate. To measure the radiation patterns, the RF probe station is modified to accommodate an open-ended rectangular waveguide as the rotating linearly polarized sampling antenna. The open-ended waveguide is attached through a coaxial rotary joint to a Plexiglas(Trademark) arm and is driven along an arc by a stepper motor. Thus, the spinning open-ended waveguide can sample the relative field intensity of the patch as a function of the angle from bore sight. The experimental results include the measured linearly polarized and circularly polarized radiation patterns for MEMS-based frequency reconfigurable rectangular and polarization reconfigurable nearly square patch antennas, respectively.

  7. Electromagnetic model of a near-field cable-free impedance and gain measurement technique for electrically small antennas

    DEFF Research Database (Denmark)

    Zhang, Jiaying; Pivnenko, Sergey; Breinbjerg, Olav

    2011-01-01

    In this paper, a novel near-field cable-free impedance and gain measurement technique for electrically small antennas is proposed. In this technique, with the electrically small antenna placed in the near-field region of the probe, the properties of this antenna are extracted by measuring the...

  8. Transbronchial needle aspiration. An underused diagnostic technique.

    Science.gov (United States)

    Dasgupta, A; Mehta, A C

    1999-03-01

    Despite its proven usefulness, TBNA is not widely used. An American College of Chest Physicians (ACCP) survey showed that only 11.8% of pulmonologists use TBNA. Most pulmonologists in the 1980s were not formally trained in TBNA. This lack of training has unfortunately translated to minimal emphasis on TBNA in current training programs in a large number of institutions. Technical problems with the procedure (faulty site selection, incomplete needle penetration, catheter kinking that prevents adequate suction, etc.), the confusing array of needles, low diagnostic yields, unproven concerns regarding the safety of the procedure, inadequate cytopathology support, and bronchoscopic damage have all perpetuated the image of limited usefulness for this procedure. Limitations to the practice of TBNA are: Lack of training during fellowship Technical inadequacies Lack of cytopathologists trained in TBNA interpretation Fear of bronchoscope damage Safety issues Failure to reproduce published successes Reservations regarding usefulness of TBNA results Hands-on experience with TBNA, developing familiarity and expertise with only a few needles, and paying careful attention to anatomy, procedure techniques, and specimen acquisition may all help to increase yield. The following lists how better results can be obtained with TBNA: Preprocedure Review TBNA instruction tapes Attend hands-on courses Practice with lung models Review patient's CAT scans Familiarize with one-two cytology and histology needle Obtain a trained assistant Procedural Identify target site Needle to airway angle at least greater than 45 degrees Insert entire length of the needle Use scope channel to support the catheter Release suction before withdrawing needle (for staging) Specimen acquisition Avoid delay in preparing slides Adequate sampling (at least two) Use smear method for cytology specimen Analyze all samples flush solutions cell block Postprocedure Find an experienced cytopathologist Review your procedure

  9. Bandwidth Enhancement Technique of the Meandered Monopole Antenna

    Directory of Open Access Journals (Sweden)

    Chien-Jen Wang

    2015-01-01

    Full Text Available A small dual-band monopole antenna with coplanar waveguide (CPW feeding structure is presented in this paper. The antenna is composed of a meandered monopole, an extended conductor tail, and an asymmetrical ground plane. Tuning geometrical structure of the ground plane excites an additional resonant frequency band and thus enhances the impedance bandwidth of the meandered monopole antenna. Unlike the conventional monopole antenna, the new resonant mode is excited by a slot trace of the CPW transmission line. The radiation performance of the slot mode is as similar as that of the monopole. The parametrical effect of the size of the one-side ground plane on impedance matching condition has been derived by the simulation. The measured impedance bandwidths, which are defined by the reflection coefficient of −6 dB, are 186 MHz (863–1049 MHz, 19.4% at the lower resonant band and 1320 MHz (1490–2810 MHz, 61.3% at the upper band. From the results of the reflection coefficients of the proposed monopole antenna, the operated bandwidths of the commercial wireless communication systems, such as GSM 900, DCS, IMT-2000, UMTS, WLAN, LTE 2300, and LTE 2500, are covered for uses.

  10. Double phi-Step theta-Scanning Technique for Spherical Near-Field Antenna Measurements

    DEFF Research Database (Denmark)

    Laitinen, Tommi

    2008-01-01

    Probe-corrected spherical near-field antenna measurements with an arbitrary probe set certain requirements on an applicable scanning technique. The computational complexity of the general high-order probe correction technique for an arbitrary probe, that is based on the Phi scanning, is O(N4...... a specific double Phi-step thetas scanning technique for spherical near-field antenna measurements. This technique not only constitutes an alternative spherical scanning technique, but it also enables formulating an associated probe correction technique for arbitrary probes with the computational...

  11. Systems analysis for DSN microwave antenna holography

    Science.gov (United States)

    Rochblatt, D. J.

    1989-01-01

    Proposed systems for Deep Space Network (DSN) microwave antenna holography are analyzed. Microwave holography, as applied to antennas, is a technique which utilizes the Fourier Transform relation between the complex far-field radiation pattern of an antenna and the complex aperture field distribution to provide a methodology for the analysis and evaluation of antenna performance. Resulting aperture phase and amplitude distribution data are used to precisely characterize various crucial performance parameters, including panel alignment, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation. Microwave holographic analysis provides diagnostic capacity as well as being a powerful tool for evaluating antenna design specifications and their corresponding theoretical models.

  12. Non-Foster Impedance Wideband Matching Technique for Electrically Small Active Antenna

    Directory of Open Access Journals (Sweden)

    Wenxing Li

    2013-01-01

    Full Text Available This paper investigates a non-Foster wideband circuit matching technique for an electrically small antenna (ESA. By introducing a negative impedance convertor into an active network, the active network can obtain an equivalent input gain at input port to improve gain, sensitivity and output ratio of signal to noise. In addition, it also increases the effective height of active antenna. The experimental results have verified the proposed method by using a 100 KHz–30 MHz wideband active receiving monopole antenna.

  13. The TIGA technique for detecting gravitational waves with a spherical antenna

    CERN Document Server

    Merkowitz, S M; Merkowitz, Stephen M.; Johnson, Warren W.

    1997-01-01

    We report the results of a theoretical and experimental study of a spherical gravitational wave antenna. We show that it is possible to understand the data from a spherical antenna with 6 radial resonant transducers attached to the surface in the truncated icosahedral arrangement. We find that the errors associated with small deviations from the ideal case are small compared to other sources of error, such as a finite signal-to-noise ratio. An in situ measurement technique is developed along with a general algorithm that describes a procedure for determining the direction of an external force acting on the antenna, including the force from a gravitational wave, using a combination of the transducer responses. The practicality of these techniques was verified on a room-temperature prototype antenna.

  14. Problems of technique of organizing antenna laboratory course

    OpenAIRE

    Andreev, M. V.; Drobakhin, Oleg O.; Morozov, V. M.; Saltykov, D. Yu.

    1999-01-01

    Now our daily life is characterized by wide application of modern means of telecommunications. First of all satellite television and mobile communication means, including cellular ones, must be mentioned. The feature of this means is a wide usage of micro-wave electromagnetic waves especially of the range 11–12 GHz, which has elements with properties and construction distinct from more low frequencies ones in many respects. First of all, this fact concerns antenna devices. The pointed circums...

  15. The TIGA technique for detecting gravitational waves with a spherical antenna

    OpenAIRE

    Merkowitz, Stephen M.; Johnson, Warren W.

    1997-01-01

    We report the results of a theoretical and experimental study of a spherical gravitational wave antenna. We show that it is possible to understand the data from a spherical antenna with 6 radial resonant transducers attached to the surface in the truncated icosahedral arrangement. We find that the errors associated with small deviations from the ideal case are small compared to other sources of error, such as a finite signal-to-noise ratio. An in situ measurement technique is developed along ...

  16. Clinical technique: techniques in the practice diagnostic laboratory: a review.

    Science.gov (United States)

    Doneley, Bob

    2015-01-01

    The need to rapidly diagnose disease in avian/exotic animal patients has led to the increased use of on-site diagnostic testing by veterinarians treating these animals. This article explores the use of on-site veterinary diagnostic testing: advantages and disadvantages of such testing; tests that are performed; type of equipment available; and the need for quality control. PMID:25421031

  17. Iterative probe correction technique for spherical near-field antenna measurements

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey; Breinbjerg, Olav

    2005-01-01

    An iterative probe correction technique is presented to correct for the errors caused by the application of the traditional first-order probe correction for nonideal first-order probes in spherical near-field antenna measurements. The technique may be applied, with certain restrictions, for more...

  18. Invasive diagnostic techniques in idiopathic interstitial pneumonias.

    Science.gov (United States)

    Poletti, Venerino; Ravaglia, Claudia; Gurioli, Carlo; Piciucchi, Sara; Dubini, Alessandra; Cavazza, Alberto; Chilosi, Marco; Rossi, Andrea; Tomassetti, Sara

    2016-01-01

    Fibrosing interstitial lung diseases (f-ILDs) represent a heterogeneous group of disorders in which the aetiology may be identified or, not infrequently, remain unknown. Establishing a correct diagnosis of a distinct f-ILD requires a multidisciplinary approach, integrating clinical profile, physiological and laboratory data, radiological appearance and, when appropriate, histological findings. Surgical lung biopsy is still considered the most important diagnostic tool as it is able to provide lung samples large enough for identification of complex patterns such as usual interstitial pneumonitis (UIP) and nonspecific interstitial pneumonitis. However, this procedure is accompanied by significant morbidity and mortality. Bronchoalveolar lavage is still a popular diagnostic tool allowing identification of alternative diagnoses in patients with suspected idiopathic pulmonary fibrosis (IPF) when an increase in lymphocytes is detected. Conventional transbronchial lung biopsy has a very low sensitivity in detecting the UIP pattern and its role in this clinical-radiological context is marginal. The introduction of less invasive methods such as transbronchial cryobiopsy show great promise to clinical practice as they can be used to obtain samples large enough to morphologically support a diagnosis of IPF or other idiopathic interstitial pneumonias, along with fewer complications. Recent advances in the field suggest that less invasive methods of lung sampling, without significant side effects, in combination with other diagnostic methods could replace the need for surgical lung biopsy in the future. Indeed, these new multidisciplinary procedures may become the main diagnostic work-up method for patients with suspected idiopathic interstitial pneumonia. PMID:26682637

  19. Laboratory diagnostic techniques for Entamoeba species.

    Science.gov (United States)

    Fotedar, R; Stark, D; Beebe, N; Marriott, D; Ellis, J; Harkness, J

    2007-07-01

    The genus Entamoeba contains many species, six of which (Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, Entamoeba polecki, Entamoeba coli, and Entamoeba hartmanni) reside in the human intestinal lumen. Entamoeba histolytica is the causative agent of amebiasis and is considered a leading parasitic cause of death worldwide in humans. Although recent studies highlight the recovery of E. dispar and E. moshkovskii from patients with gastrointestinal symptoms, there is still no convincing evidence of a causal link between the presence of these two species and the symptoms of the host. New approaches to the identification of E. histolytica are based on detection of E. histolytica-specific antigen and DNA in stool and other clinical samples. Several molecular diagnostic tests, including conventional and real-time PCR, have been developed for the detection and differentiation of E. histolytica, E. dispar, and E. moshkovskii in clinical samples. The purpose of this review is to discuss different methods that exist for the identification of E. histolytica, E. dispar, and E. moshkovskii which are available to the clinical diagnostic laboratory. To address the need for a specific diagnostic test for amebiasis, a substantial amount of work has been carried out over the last decade in different parts of the world. The molecular diagnostic tests are increasingly being used for both clinical and research purposes. In order to minimize undue treatment of individuals infected with other species of Entamoeba such as E. dispar and E. moshkovskii, efforts have been made for specific diagnosis of E. histolytica infection and not to treat based simply on the microscopic examination of Entamoeba species in the stool. The incorporation of many new technologies into the diagnostic laboratory will lead to a better understanding of the public health problem and measures to control the disease. PMID:17630338

  20. Recent Advances in Beam Diagnostic Techniques

    Science.gov (United States)

    Fiorito, R. B.

    2002-12-01

    We describe recent advances in diagnostics of the transverse phase space of charged particle beams. The emphasis of this paper is on the utilization of beam-based optical radiation for the precise measurement of the spatial distribution, divergence and emittance of relativistic charged particle beams. The properties and uses of incoherent as well as coherent optical transition, diffraction and synchrotron radiation for beam diagnosis are discussed.

  1. All-optical delay technique for supporting multiple antennas in a hybrid optical - wireless transmission system

    DEFF Research Database (Denmark)

    Prince, Kamau; Chiuchiarelli, A; Presi, M;

    2008-01-01

    We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency.......We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency....

  2. A singularity extraction technique for computation of antenna aperture fields from singular plane wave spectra

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Breinbjerg, Olav; Frandsen, Aksel

    2008-01-01

    An effective technique for extracting the singularity of plane wave spectra in the computation of antenna aperture fields is proposed. The singular spectrum is first factorized into a product of a finite function and a singular function. The finite function is inverse Fourier transformed numerica......An effective technique for extracting the singularity of plane wave spectra in the computation of antenna aperture fields is proposed. The singular spectrum is first factorized into a product of a finite function and a singular function. The finite function is inverse Fourier transformed...... numerically using the Inverse Fast Fourier Transform, while the singular function is inverse Fourier transformed analytically, using the Weyl-identity, and the two resulting spatial functions are then convolved to produce the antenna aperture field. This article formulates the theory of the singularity...

  3. Enthalpy Probe Technique for Thermal Plasma Diagnostics

    Institute of Scientific and Technical Information of China (English)

    冯晓珍

    2003-01-01

    The measuring principle and experimental results of the enthalpy probe techniquefor thermal plasma diagnostics are presented. Its calibration and errors are discussed. Typicalresults are presented for the system operation in an Ar/H2(5 % H2) plasma arc jet under a reactorchamber pressure of 101.3 kPa. The plasma temperature and velocity profiles are measured. Thecenter temperature and velocity are 6600 K and 850 m/s for plasma power 9 kW at axial locationof 17 mm.

  4. Noninvasive Remote Sensing Techniques for Infrastructures Diagnostics

    OpenAIRE

    Angelo Palombo; Stefano Pignatti; Angela Perrone; Francesco Soldovieri; Tony Alfredo Stabile; Simone Pascucci

    2011-01-01

    The present paper aims at analyzing the potentialities of noninvasive remote sensing techniques used for detecting the conservation status of infrastructures. The applied remote sensing techniques are ground-based microwave radar interferometer and InfraRed Thermography (IRT) to study a particular structure planned and made in the framework of the ISTIMES project (funded by the European Commission in the frame of a joint Call “ICT and Security” of the Seventh Framework Programme). To exploit ...

  5. Comparative analyses of plasma probe diagnostics techniques

    Energy Technology Data Exchange (ETDEWEB)

    Godyak, V. A. [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA and RF Plasma Consulting, Brookline, Massachusetts 02446 (United States); Alexandrovich, B. M. [Plasma Sensors, Brookline, Massachusetts 02446 (United States)

    2015-12-21

    The subject of this paper is a comparative analysis of the plasma parameters inferred from the classical Langmuir probe procedure, from different theories of the ion current to the probe, and from measured electron energy distribution function (EEDF) obtained by double differentiation of the probe characteristic. We concluded that the plasma parameters inferred from the classical Langmuir procedure can be subjected to significant inaccuracy due to the non-Maxwellian EEDF, uncertainty of locating the plasma potential, and the arbitrariness of the ion current approximation. The plasma densities derived from the ion part of the probe characteristics diverge by as much as an order of magnitude from the density calculated according to Langmuir procedure or calculated as corresponding integral of the measured EEDF. The electron temperature extracted from the ion part is always subjected to uncertainty. Such inaccuracy is attributed to modification of the EEDF for fast electrons due to inelastic electron collisions, and to deficiencies in the existing ion current theories; i.e., unrealistic assumptions about Maxwellian EEDFs, underestimation of the ion collisions and the ion ambipolar drift, and discounting deformation of the one-dimensional structure of the region perturbed by the probe. We concluded that EEDF measurement is the single reliable probe diagnostics for the basic research and industrial applications of highly non-equilibrium gas discharge plasmas. Examples of EEDF measurements point up importance of examining the probe current derivatives in real time and reiterate significance of the equipment technical characteristics, such as high energy resolution and wide dynamic range.

  6. Comparative analyses of plasma probe diagnostics techniques

    International Nuclear Information System (INIS)

    The subject of this paper is a comparative analysis of the plasma parameters inferred from the classical Langmuir probe procedure, from different theories of the ion current to the probe, and from measured electron energy distribution function (EEDF) obtained by double differentiation of the probe characteristic. We concluded that the plasma parameters inferred from the classical Langmuir procedure can be subjected to significant inaccuracy due to the non-Maxwellian EEDF, uncertainty of locating the plasma potential, and the arbitrariness of the ion current approximation. The plasma densities derived from the ion part of the probe characteristics diverge by as much as an order of magnitude from the density calculated according to Langmuir procedure or calculated as corresponding integral of the measured EEDF. The electron temperature extracted from the ion part is always subjected to uncertainty. Such inaccuracy is attributed to modification of the EEDF for fast electrons due to inelastic electron collisions, and to deficiencies in the existing ion current theories; i.e., unrealistic assumptions about Maxwellian EEDFs, underestimation of the ion collisions and the ion ambipolar drift, and discounting deformation of the one-dimensional structure of the region perturbed by the probe. We concluded that EEDF measurement is the single reliable probe diagnostics for the basic research and industrial applications of highly non-equilibrium gas discharge plasmas. Examples of EEDF measurements point up importance of examining the probe current derivatives in real time and reiterate significance of the equipment technical characteristics, such as high energy resolution and wide dynamic range

  7. Circularly polarized antennas

    CERN Document Server

    Gao, Steven; Zhu, Fuguo

    2013-01-01

    This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

  8. Enhancing Wireless Information and Power Transfer by Exploiting Multi-Antenna Techniques

    OpenAIRE

    Chen, Xiaoming; Zhang, Zhaoyang; Chen, Hsiao-Hwa; Zhang, Huazi

    2015-01-01

    This paper reviews emerging wireless information and power transfer (WIPT) technique with an emphasis on its performance enhancement employing multi-antenna techniques. Compared to traditional wireless information transmission, WIPT faces numerous challenges. First, it is more susceptible to channel fading and path loss, resulting in a much shorter power transfer distance. Second, it gives rise to the issue on how to balance spectral efficiency for information transmission and energy efficien...

  9. Application of Capon technique to mitigate bird contamination on a spaced antenna wind profiler

    Science.gov (United States)

    Chen, Meng-Yuan; Yu, Tian-You; Chu, Yen-Hsyang; Brown, William O. J.; Cohn, Stephen A.

    2007-12-01

    A novel technique is developed for profiling radars to measure atmospheric wind fields when signals are contaminated by migrating birds. It exploits the idea of adaptive beamforming to suppress the interference from birds to provide accurate three-dimensional wind measurements using a spaced antenna system. Numerical simulations based on the configuration of the UHF Multiple Antenna Profiler Radar of the National Center for Atmospheric Research are implemented to investigate the performance and the limitation of the proposed technique. The feasibility of atmospheric wind measurements is further demonstrated by using the experimental data. Wind measurements from the full correlation analysis (FCA) and postset beam steering (PBS) are also provided for comparisons. During the period when a single bird is present in the radar beam, the proposed technique produces wind estimates that are consistent with atmospheric wind field prior to the entry of the bird, while both FCA and PBS wind estimates are biased.

  10. Development of process diagnostic techniques for piping and equipment

    International Nuclear Information System (INIS)

    The thing required for using the facilities composing a plant for a long period without anxiety is to quantitatively grasp the quantities of the present condition of the facilities and to take the necessary measures beforehand. For this purpose, the diagnostic techniques for quickly and accurately detect the quantities of the condition of facilities are necessary, and the development of process diagnostic techniques has been desired. The process diagnostic techniques mentioned here mean those for diagnosing the contamination, clogging and performance of towers, tanks, heat exchangers and others. Idemitsu Engineering Co. had developed a simplified diagnostic equipment for detecting the state of fouling in piping in 1982, which is the gamma ray transmission diagnosis named Scale Checker. By further improving it, the process diagnostic techniques for piping and equipment were developed. In this report, the course of development and examination, the principle of detection, the constitution and the examination of remodeling of the Scale Checker are reported. As the cases of process diagnosis in plant facilities, the diagnosis of the clogging in process piping and the diagnosis of the performance of a distillation tower were carried out. The contents of the diagnosis and the results of those cases are explained. (Kako, I.)

  11. Opto-microwave technique in the promising active phased antenna arrays

    OpenAIRE

    Bakhrakh, Lev D.; Shifrin, Yakov S.

    1995-01-01

    Implementation of multi-element active phased antenna arrays (APAA) due to poor mass-overall dimensions characteristics, signals distribution system complexity is rather difficult. Extra difficulties arise with wide-band signals and millimeter waves APAA. The signal distribution fiber-optical systems using elements of laser technique and other elements of opto-electronics allow in many cases to solve completely the problem of the signals distribution system and pilot and monitor signals in AP...

  12. A Size Reduction Technique for Mobile Phone PIFA Antennas Using Lumped Inductors

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2005-01-01

    A size reduction technique for the planar inverted-F antenna (PIFA) is presented. An 18 nH lumped inductor is used in addition to a small 0.3 cm3 PIFA. The PIFA is located on dielectric foam, 5 mm above a 40 mm × 100 mm ground plane. It is possible to reduce the center frequency (|S11|min) by 33...

  13. Aneurysmal bone cyst: revision of different techniques in imaging diagnostic

    International Nuclear Information System (INIS)

    We study simple radiology, conventional tomography, computed tomography and angiography in 8 cases of aneurysmal bone cyst for the purpose of assessing the utility of these diagnostic techniques. Our results, in agreement with those in the literature, indicate that the presence of a generally well-defined lytic, insufflated lesion containing septi should suggest this disorder. (Author)

  14. Evaluation of Possible Nuclear Magnetic Resonance Diagnostic Techniques for Tokamak Experiments

    International Nuclear Information System (INIS)

    Potential applications of nuclear magnetic resonance (NMR) diagnostic techniques to tokamak experiments are evaluated. NMR frequencies for hydrogen isotopes and low-Z nuclei in such experiments are in the frequency range approximately equal to 20-200 MHz, so existing RF [radio-frequency] antennas could be used to rotate the spin polarization and to make the NMR measurements. Our tentative conclusion is that such measurements are possible if highly spin polarized H or (superscript)3He gas sources (which exist) are used to fuel these plasmas. In addition, NMR measurements of the surface layers of the first wall (without plasma) may also be possible, e.g., to evaluate the inventory of tritium inside the vessel

  15. Microstrip Antenna

    OpenAIRE

    Anuj Mehta

    2015-01-01

    Abstract This article presents an overview of the microstrip patch antenna and its design techniques. Basically a microstrip patch antenna comprises of a trace of copper or any other metal of any geometry on one side of a standard printed circuit board substrate with other side grounded. The antenna is fed using various feeding techniques like coaxial strip line aperture coupling or proximity coupling techniques. The working principle and the radiation mechanism have also been described. The ...

  16. A new technique to improve pointing performance for ship-borne mobile telemetry antenna system

    Science.gov (United States)

    Lee, Sun Ik; Yeom, Kyung-Whan

    2015-09-01

    A new technique to improve the tracking performance of a ship-borne mobile telemetry antenna system in the marine environment is presented for Korea Space Launch Vehicle-I (KSLV-I) mission. The concept of 'pointing bias' is introduced to compensate for the instability or inaccuracy of a sensor in the ship-borne mobile telemetry antenna system. The LEO satellites in the form of 'tracking campaign' are used to measure the pointing bias. The proposed technique is verified through the tests in Jeju sea and Pacific sea in the period of November 23-28, 2012. The results demonstrated that the azimuth pointing bias about -0.27° and -0.49° appears in Jeju sea and Pacific sea, respectively and the pointing bias was proved to be mainly relevant to the heading measurement error of the gyrocompass. Taking into consideration of the pointing bias results in Jeju sea and Pacific sea, the gyrocompass was corrected by 0.25° to compensate for the heading measurement error on the ship-borne mobile telemetry antenna system. The correction value of 0.25° is selected to reduce the risk in tracking. Due to insufficient correction, the residual pointing bias about -0.12° in Pacific sea was observed and the successful tracking of KSLV-I is achieved on January 30, 2013.

  17. Progress in diagnostic techniques for SC [superconducting] cavities

    International Nuclear Information System (INIS)

    Despite the very real progress that has been made, the routine performance of superconducting cavities still falls far short of both the theoretical expectations and the performance of afew exceptional examples. It is the task of systematically applied diagnostic techniques to reveal additional information concerning the response of superconducting surfaces to applied RF fields. In this paper we will direct our attention to discussions of recent developments in diagnostic techniqeus, such as thermometry in superfluid helium, and scanning laser acoustic microscopy. 18 refs., 12 figs

  18. Analysis of elliptically polarized cavity backed antennas using a combined FEM/MoM/GTD technique

    Science.gov (United States)

    Reddy, C. J.; Deshpande, M. D.; Fralick, D. T.

    1995-01-01

    Radiation pattern prediction analysis of elliptically polarized cavity backed aperture antennas in a finite ground plane is carried out using a combined finite element method (FEM)/method of moments (MoM)/geometrical theory of diffraction (GTD) technique. The magnetic current on the cavity-backed aperture in an infinite ground plane is calculated using the combined FEM/MoM analysis. GTD, including the slope diffraction contribution, is used to calculate the diffracted fields due to both soft and hard polarizations at the edges of the finite ground plane. Numerical results for the radiation patterns of a cavity backed circular spiral microstrip patch antenna excited by a coaxial probe in a finite rectangular ground plane are computed and compared with experimental results.

  19. A Review and study of the design technique of Microstrip Patch Antenna Technology

    Directory of Open Access Journals (Sweden)

    Dileep Kumar shukla

    2015-03-01

    Full Text Available In this paper,study and survey of microstrip antenna elements is presented, with emphasis on theoretical and practical design techniques and material used, as previous study have been proved that material used play significant role in the performance such as gain ,directivity ,frequency of radiation Available substrate materials are reviewed along with the relation between dielectric constant tolerance and resonant frequency of microstrip patches. Several theoretical analysis techniques are summarized. Practical procedures are given for both standard rectangular and circular patches. The quality, bandwidth, and efficiency factors of typical patch designs are discussed.

  20. A novel technique and soldering method to improve performance of transparent polymer antennas

    OpenAIRE

    Peter, T; Nilavalan, R; AbuTarboush, HF; Cheung, SW

    2010-01-01

    A novel technique and a nonthermal soldering method to improve the performance of AgHT-8 transparent polymer antennas are proposed in this letter. The proposed technique involves the removal of the coating layer at areas on the coplanar waveguide (CPW) ground and feed line where the connectors of the coaxial feed or legs of the SMA connectors will be attached and applying a coat of silver paint on the exposed areas before cold-soldering the coaxial connections or SMA connector legs. The nonth...

  1. Embroidery and Related Manufacturing Techniques for Wearable Antennas: Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Aris Tsolis

    2014-05-01

    Full Text Available This paper will review the evolution of wearable textile antennas over the last couple of decades. Particular emphasis will be given to the process of embroidery. This technique is advantageous for the following reasons: (i bespoke or mass produced designs can be manufactured using digitized embroidery machines; (ii glue is not required and (iii the designs are aesthetic and are integrated into clothing rather than being attached to it. The embroidery technique will be compared to alternative manufacturing processes. The challenges facing the industrial and public acceptance of this technology will be assessed. Hence, the key opportunities will be highlighted.

  2. On the comparsion of the Spherical Wave Expansion-to-Plane Wave Expansion and the Sources Reconstruction Method for Antenna Diagnostics

    DEFF Research Database (Denmark)

    Alvarez, Yuri; Cappellin, Cecilia; Las-Heras, Fernando; Breinbjerg, Olav

    2008-01-01

    A comparison between two recently developed methods for antenna diagnostics is presented. On one hand, the Spherical Wave Expansion-to-Plane Wave Expansion (SWE-PWE), based on the relationship between spherical and planar wave modes. On the other hand, the Sources Reconstruction Method (SRM), bas...... on the application of the equivalence principle and the integral equations relating fields and sources. In order to compare the results provided by these methods, a reflector antenna has been measured and analyzed...

  3. Swept-frequency acoustic interferometry technique for noninvasive chemical diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, D.N.; Springer, K.N.; Han, Wei; Lizon, D.C.; Houlton, R.J.

    1997-02-01

    Swept-Frequency Acoustic Interferometry (SFAI) is a noninvasive fluid characterization technique currently being developed for chemical weapons treaty verification. The SFAI technique determines sound speed and sound attenuation in a fluid over a wide frequency range from outside a container (e.g., reactor vessel, tank, pipe, industrial containers etc.). From the frequency dependence of sound attenuation, fluid density can also be determined. These physical parameters. when combined together, can be used to identify a range of chemicals. This technique can be adapted for chemical diagnostic applications, particularly in process control where monitoring of acoustic properties of chemicals (liquids, mixtures, emulsions, suspensions, etc.) may provide appropriate feedback information. The SFAI theory is discussed and experimental techniques are presented. Examples of several novel applications of the SFAI technique are also presented.

  4. Use of rapid diagnostic techniques in ICU patients with infections

    OpenAIRE

    Burillo, Almudena; Bouza, Emilio

    2014-01-01

    Background Infection is a common complication seen in ICU patients. Given the correlation between infection and mortality in these patients, a rapid etiological diagnosis and the determination of antimicrobial resistance markers are of paramount importance, especially in view of today’s globally spread of multi drug resistance microorganisms. This paper reviews some of the rapid diagnostic techniques available for ICU patients with infections. Methods A narrative review of recent peer-reviewe...

  5. Fusion alpha loss diagnostic for ITER using activation technique

    Czech Academy of Sciences Publication Activity Database

    Bonheure, G.; Hult, M.; González de Orduña, R.; Vermaercke, P.; Murari, A.; Popovichev, S.; Mlynář, Jan

    2011-01-01

    Roč. 86, 6-8 (2011), s. 1298-1301. ISSN 0920-3796. [Symposium on Fusion Technology (SOFT) /26th./. Porto, 27.09.2010-01.10.2010] Institutional research plan: CEZ:AV0Z20430508 Keywords : ITER * fusion product * burning plasma diagnostics * alpha losses * activation technique Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.490, year: 2011 http://www.sciencedirect.com/science/article/pii/S0920379611002778

  6. On the applicability range of the iterative probe correction technique in spherical near-field antenna measurements

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey; Breinbjerg, Olav

    An iterative probe correction technique for spherical near-field antenna measurements is examined. This technique has previously been shown to be ideally-suited for non-ideal first-order probes. In this paper its performance for other probes is examined.......An iterative probe correction technique for spherical near-field antenna measurements is examined. This technique has previously been shown to be ideally-suited for non-ideal first-order probes. In this paper its performance for other probes is examined....

  7. Recent Advances in Antenna Measurement Techniques at the DTU-ESA Spherical Near-Field Antenna Test Facility

    DEFF Research Database (Denmark)

    Breinbjerg, Olav; Pivnenko, Sergey; Kim, Oleksiy S.; Nielsen, Jeppe Majlund

    2014-01-01

    This paper reports recent antenna measurement projects and research at the DTU-ESA Spherical Near-Field Antenna Test Facility at the Technical University of Denmark. High-accuracy measurement projects for the SMOS, SENTINEL-1, and BIOMASS missions of the European Space Agency were driven by...... uncertainty requirements of a few hundredths of dB for the directivity and correspondingly strong requirements for gain and/or phase. Research and development of 1:3 bandwidth range probes, and the near-field to far-field transformation algorithm accounting for the higher-order azimuthal modes in the...

  8. A Size Reduction Technique for Mobile Phone PIFA Antennas Using Lumped Inductors

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2005-01-01

    A size reduction technique for the planar inverted-F antenna (PIFA) is presented. An 18 nH lumped inductor is used in addition to a small 0.3 cm3 PIFA. The PIFA is located on dielectric foam, 5 mm above a 40 mm × 100 mm ground plane. It is possible to reduce the center frequency (|S11|min) by 33...... percent for a fixed physical size. The measured – 6 dB bandwidth is 6.7 percent with a peak radiation efficiency of 88 percent....

  9. Improvement of antenna measurement results at low frequencies by using post-processing techniques

    OpenAIRE

    Le Fur, Gwenn; Cano-Facila, Francisco; Saccardi, Francesco; Belot, Daniel; Durand, Ludovic; Duchesne, Luc; Foged, L. J.; Lopez, Jean-Marc; Bellion, Anthony

    2014-01-01

    — This paper presents a part of a whole study dedicated to the design of an indoor near-field antenna measurement system in VHF range. During this study a new wide band probe covering the 50 to 400 MHz bandwidth was developed, manufactured and characterized. The paper will focus on the use of post-processing techniques to improve measurement results. Measurements have been done in two different systems. Results are given to show the capability of Time Domain filtering and Equivalent Current A...

  10. A new jamming technique for secrecy in multi-antenna wireless networks

    KAUST Repository

    Bakr, Omar

    2010-06-01

    We consider the problem of secure wireless communication in the presence of an eavesdropper when the transmitter has multiple antennas, using a variation of the recently proposed artificial noise technique. Under this technique, the transmitter sends a pseudo-noise jamming signal to selectively degrade the link to the eavesdropper without affecting the desired receiver. The previous work in the literature focuses on ideal Gaussian signaling for both the desired signal and the noise signal. The main contribution of this paper is to show that the Gaussian signaling model has important limitations and propose an alternative "induced fading" jamming technique that takes some of these limitations into account. Specifically we show that under the Gaussian noise scheme, the eavesdropper is able to recover the desired signal with very low bit error rates when the transmitter is constrained to use constant envelope signaling. Furthermore, we show that an eavesdropper with multiple antennas is able to use simple, blind constant-envelope algorithms to completely remove the Gaussian artificial noise signal and thus defeat the secrecy scheme. We propose an alternative scheme that induces artificial fading in the channel to the eavesdropper, and show that it outperforms the Gaussian noise scheme in the sense of causing higher bit error rates at the eavesdropper and is also more resistant to constant modulus-type algorithms. © 2010 IEEE.

  11. LeRC rail accelerators: test designs and diagnostic techniques

    International Nuclear Information System (INIS)

    The feasibility of using rail accelerators for various in-space and to-space propulsion applications was investigated. A 1 meter, 24 sq mm bore accelerator was designed with the goal of demonstrating projectile velocities of 15 km/sec using a peak current of 200 kA. A second rail accelerator, 1 meter long with a 156.25 sq mm bore, was designed with clear polycarbonate sidewalls to permit visual observation of the plasma arc. A study of available diagnostic techniques and their application to the rail accelerator is presented. Specific topics of discussion include the use of interferometry and spectroscopy to examine the plasma armature as well as the use of optical sensors to measure rail displacement during acceleration. Standard diagnostics such as current and voltage measurements are also discussed. 15 references

  12. A Review of Diagnostic Techniques for ISHM Applications

    Science.gov (United States)

    Patterson-Hine, Ann; Biswas, Gautam; Aaseng, Gordon; Narasimhan, Sriam; Pattipati, Krishna

    2005-01-01

    System diagnosis is an integral part of any Integrated System Health Management application. Diagnostic applications make use of system information from the design phase, such as safety and mission assurance analysis, failure modes and effects analysis, hazards analysis, functional models, fault propagation models, and testability analysis. In modern process control and equipment monitoring systems, topological and analytic , models of the nominal system, derived from design documents, are also employed for fault isolation and identification. Depending on the complexity of the monitored signals from the physical system, diagnostic applications may involve straightforward trending and feature extraction techniques to retrieve the parameters of importance from the sensor streams. They also may involve very complex analysis routines, such as signal processing, learning or classification methods to derive the parameters of importance to diagnosis. The process that is used to diagnose anomalous conditions from monitored system signals varies widely across the different approaches to system diagnosis. Rule-based expert systems, case-based reasoning systems, model-based reasoning systems, learning systems, and probabilistic reasoning systems are examples of the many diverse approaches ta diagnostic reasoning. Many engineering disciplines have specific approaches to modeling, monitoring and diagnosing anomalous conditions. Therefore, there is no "one-size-fits-all" approach to building diagnostic and health monitoring capabilities for a system. For instance, the conventional approaches to diagnosing failures in rotorcraft applications are very different from those used in communications systems. Further, online and offline automated diagnostic applications are integrated into an operations framework with flight crews, flight controllers and maintenance teams. While the emphasis of this paper is automation of health management functions, striking the correct balance between

  13. Reconfigurable antennas

    CERN Document Server

    Bernhard, Jennifer

    2007-01-01

    This lecture explores the emerging area of reconfigurable antennas from basic concepts that provide insight into fundamental design approaches to advanced techniques and examples that offer important new capabilities for next-generation applications. Antennas are necessary and critical components of communication and radar systems, but sometimes their inability to adjust to new operating scenarios can limit system performance. Making antennas reconfigurable so that their behavior can adapt with changing system requirements or environmental conditions can ameliorate or eliminate these restricti

  14. Reference antenna techniques for canceling radio frequency interference due to moving sources

    CERN Document Server

    Mitchell, D A; 10.1029/2004RS003152

    2010-01-01

    We investigate characteristics of radio frequency interference (RFI) signals that can affect the excision potential of some interference mitigation algorithms. The techniques considered are those that modify signals from auxiliary reference antennas to model and cancel interference from an astronomical observation. These techniques can be applied in the time domain, where the RFI voltage is modeled and subtracted from the astronomy signal path (adaptive noise canceling), or they can be applied to the autocorrelated and cross-correlated voltage spectra in the frequency domain (postcorrelation canceling). For ideal receivers and a single, statistically stationary interfering signal, both precorrelation and postcorrelation filters can result in complete cancellation of the interference from the observation. The postcorrelation method has the advantage of being applied on tens or hundreds of millisecond timescales rather than tens or hundreds of nanosecond timescales. However, this can be a disadvantage if the RF...

  15. Ambulatory diagnostic and monitoring techniques for sleep disordered breathing.

    OpenAIRE

    Bruyneel, Marie

    2015-01-01

    Techniques ambulatoires de diagnostic et de monitoring des troubles respiratoires liés au sommeil.Le syndrome d’apnées obstructives du sommeil (SAOS) est un trouble du sommeil très fréquent, fortement lié à l’obésité, ce qui explique sa prévalence en pleine expansion. En parallèle, la demande d’examens polysomnographiques (PSG) en laboratoire du sommeil, méthode diagnostique de référence, est en croissance. Comme l’accès à cette technique est peu aisé, de nombreux appareils simplifiés d’enreg...

  16. Reliability of diagnostic imaging techniques in suspected acute appendicitis: proposed diagnostic protocol

    International Nuclear Information System (INIS)

    To study the utility of ultrasound and computed tomography (CT) in case of suspected appendicitis. To determine the diagnostic yield in terms of different clinical contexts and patient characteristics. to assess the costs and benefits of introducing these techniques and propose a protocol for their use. Negative appendectomies, complications and length of hospital stay in a group of 152 patients with suspected appendicitis who underwent ultrasound and CT were compared with those of 180 patients who underwent appendectomy during the same time period, but had not been selected for the first group: these patients costs for each group were calculated. In the first group, the diagnostic value of the clinical signs was also evaluated. The reliability of the clinical signs was limited, while the results with ultrasound and CT were excellent. The incidence of negative appendectomy was 9.6% in the study group and 12.2% in the control group. Moreover, there were fewer complications and a shorter hospital stay in the first group. Among men, however, the rate of negative appendectomy was lower in the control group. The cost of using ultrasound and CT in the management of appendicitis was only slightly higher than that of the control group. Although ultrasound and CT are not necessary in cases in which the probability of appendicitis is low or in men presenting clear clinical evidence, the use of these techniques is indicated in the remaining cases in which appendicitis is suspected. In children, ultrasound is the technique of choice. In all other patients, if negative results are obtained with one of the two techniques, the other should be performed. (Author) 49 refs

  17. Laser diagnodent: a comparative study with other diagnostic techniques

    International Nuclear Information System (INIS)

    An evaluation of the Diagnodent equipment (Kavo Company, Germany) for the occlusal caries detection was dane through the comparison with other conventional diagnostic techniques, such as visual inspection, intra-oral micro camera and digital X-ray. The effectiveness of the equipment in the detection of hidden caries and its viability as a diagnosis method for caries in their initial stage was also studied. Fifty eight permanent molars and premolars teeth from patients with age between 6 and 30 years were studied. The obtained results indicated that the conventional methods employed for the caries diagnosis are unable to detect the carious lesion in its initial stage. The Diagnodent equipment has this capability to detect caries presenting a flawless surface, specially the hidden caries, allowing the dentist to decide between a preventive ar a conservative procedure. The main advantage of the Diagnodent is to be an objective method, compared to the visual and radiographic ones, that are dependent on the professional interpretation. The Diagnodent is, therefore, a promising alternative as an objective and standardized diagnosis method for the final diagnostic. (author)

  18. Antenna design for fast ion collective Thomson scattering diagnostic for the international thermonuclear experimental reactor

    DEFF Research Database (Denmark)

    Leipold, Frank; Furtula, Vedran; Salewski, Mirko;

    2009-01-01

    Fast ion physics will play an important role for the international thermonuclear experimental reactor (ITER), where confined alpha particles will affect and be affected by plasma dynamics and thereby have impacts on the overall confinement. A fast ion collective Thomson scattering (CTS) diagnostic...

  19. Resonant laser techniques for combustion and flow diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Fritzon, Rolf

    1998-05-01

    This thesis presents results from two areas of research. Firstly, the resonant coherent laser techniques polarization spectroscopy (PS), degenerate four-wave mixing (DFWM) and stimulated emission (SE) have been developed in the general field of combustion diagnostics. Secondly, laser induced fluorescence (LIF) has been developed and applied for the visualization of mixture fractions in turbulent non reacting flows. PS was developed for instantaneous two-dimensional imaging of minor species in flames, the technique being demonstrated on OH and NO. Various aspects of imaging and of detection in general were investigated. Two-photon induced PS was demonstrated for the detection of NH{sub 3}, CO and N{sub 2} molecules. LIF was monitored simultaneously to allow a quantitative comparison between the techniques. Furthermore, PS and DFWM were developed for instantaneous two-dimensional OH temperature imaging. Through a novel experimental approach based on the use of a dual-wavelength dye laser and a diffraction grating the temperature imaging measurements were performed using only one laser and one CCD camera. A comparison between the two techniques was made. SE was through a crossed-beam arrangement developed for spatially resolved detection of flame species. Two-dimensional LIF was developed and applied for measuring mixture fractions in the shear layer between two co-flowing turbulent gaseous jets. The technique was further applied in a study of the mixing of a turbulent water jet impinging orthogonally onto a flat surface. Average concentration fields in the center-plane of the jet was compared with results from large eddy simulations and with data from the literature 221 refs, 48 figs, 5 tabs

  20. Time-Saving Scanning Schemes for Measurement of Electrically Large Antennas by Spherical Near-Field Technique

    DEFF Research Database (Denmark)

    Pivnenko, Sergey

    2011-01-01

    Different time-saving scanning schemes for measurement of electrically large antennas by spherical near-field technique are considered and analyzed. Significant time reduction is achieved through thinning of the scanning grid, which still allows obtaining accurate results for typical aperture...

  1. Schistosomiasis laboratory diagnostic techniques and transmission of the disease

    International Nuclear Information System (INIS)

    The objectives of the present study were to determine the efficacy of schistosomiasis laboratory diagnostic techniques, used in hospitals, in identifying those infected with S. mansoni and the possible role of the false negatives on the transmission of the disease. It was carried out in Abu Usher hospital, Gezira state. It compared two laboratory techniques, a qualitative and a quantitative method. The qualitative method was the direct smear method, used routinely in hospitals and health units. The quantitative technique was the locally modified kato method, used in research, epidemiological studies and evaluation of schistosomiasis control programmes. 288 stool samples from the hospital out patients were examined by the direct smear and the kato methods. The direct smear method indicated that 277 (96.8%) of the total examined un-infected. Examination of the stools by the kato method revealed that 161 (55.9%) were infected with S. mansoni. The difference between the numbers found infected by the two methods was highly significant (P<0.001). The intensity of infection of those found infected were categorized arbitrary into four groups: lightly (1-100 eggs/g), moderately (101-500 eggs/g), heavily (501-1000 eggs/g), and very heavily (1001+eggs/g) infected respectively. The majority of those examined were with low and moderate intensity of infection with S.mansoni, 42.23% and 46.58% respectively. The direct smear method failed to identify those with light, moderate and heavy infection. Only 3 (27.3%) out of 11 of the very heavily infected persons were detected by this technique. The difference in detecting the heavily infected person by the two diagnostic methods was significant (P<0.025). Biomphalaria pfeifferi snails were infected individually with 1, 2 and 4 miracidia. B. pfeifferi snails infected with 1 miracidium did not produce any cercariae. All infected surviving snails died 11 days after they started to shed cercariae. The control snails survived for two

  2. Reduction of the In-Band RCS of Microstrip Patch Antenna by Using Offset Feeding Technique

    Directory of Open Access Journals (Sweden)

    Weiwei Xu

    2014-01-01

    Full Text Available This paper presents a method for implementing a low in-band scattering design for microstrip patch antennas based on the analysis of structural mode scattering and radiation characteristics. The antenna structure is first designed to have the lowest structural mode scattering in a desired frequency band. The operating frequency band of the antenna is then changed to coincide with that of the lowest structural mode scattering by adjusting the feed position on the antenna (offset feeding to achieve an antenna with low in-band radar cross section (RCS. In order to reduce the level of cross polarization of the antenna caused by offset feeding, symmetry feeding structures for both single patch antennas and two-patch arrays are proposed. Examples that show the efficiency of the method are given, and the results illustrate that the in-band RCS of the proposed antennas can be reduced by as much as 17 dBsm for plane waves impinging from the normal direction compared to patch antennas fed by conventional methods.

  3. New diagnostic technique for Zeeman-compensated atomic beam slowing: technique and results

    OpenAIRE

    Molenaar, P.A.; Van Der Straten, P.; Heideman, H.G.M.; Metcalf, H.

    2001-01-01

    We have developed a new diagnostic tool for the study of Zeeman-compensated slowing of an alkali atomic beam. Our time-of-flight technique measures the longitudinal veloc- ity distribution of the slowed atoms with a resolution below the Doppler limit of 30 cm/s. Furthermore, it can map the position and velocity distribution of atoms in either ground hyperfine level inside the solenoid without any devices inside the solenoid. The technique reveals the optical pumping ef- fects, and shows in de...

  4. Evaluation and Performance Analysis of 3D Printing Technique for Ka-Band Antenna Production

    DEFF Research Database (Denmark)

    Armendariz, Unai; Rommel, Simon; Rodríguez Páez, Juan Sebastián;

    2016-01-01

    This paper presents the design and fabrication of 3D printed WR-28 waveguide horn antennas operating in the Ka-band frequency range between 26.5GHz and 40GHz. Three antennas are fabricated from polylactide acid filaments in conductive and non-conductive variants; the latter is covered with...

  5. Bandwidth Enrichment for Micro-strip Patch Antenna Using Pendant Techniques

    Directory of Open Access Journals (Sweden)

    D. Bhattacharya, R. Prasanna

    2013-08-01

    Full Text Available In rapidly expanding market for wireless communication and applications, Micro strip antenna has become widely popular as it is low profile, comfortable to the hosting surfaces, light weight and can be easily integrated with the electronic circuits. Microstrip antenna is widely used in military, mobile communication, global positioning system (GPS, remote sensing etc.

  6. Development of advanced strain diagnostic techniques for reactor environments.

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Darryn D.; Holschuh, Thomas Vernon,; Miller, Timothy J.; Hall, Aaron Christopher; Urrea, David Anthony,; Parma, Edward J.,

    2013-02-01

    The following research is operated as a Laboratory Directed Research and Development (LDRD) initiative at Sandia National Laboratories. The long-term goals of the program include sophisticated diagnostics of advanced fuels testing for nuclear reactors for the Department of Energy (DOE) Gen IV program, with the future capability to provide real-time measurement of strain in fuel rod cladding during operation in situ at any research or power reactor in the United States. By quantifying the stress and strain in fuel rods, it is possible to significantly improve fuel rod design, and consequently, to improve the performance and lifetime of the cladding. During the past year of this program, two sets of experiments were performed: small-scale tests to ensure reliability of the gages, and reactor pulse experiments involving the most viable samples in the Annulated Core Research Reactor (ACRR), located onsite at Sandia. Strain measurement techniques that can provide useful data in the extreme environment of a nuclear reactor core are needed to characterize nuclear fuel rods. This report documents the progression of solutions to this issue that were explored for feasibility in FY12 at Sandia National Laboratories, Albuquerque, NM.

  7. Antenna systems research

    OpenAIRE

    Keen, Keith Malcolm

    1999-01-01

    This thesis is an overview of a number of investigations on antenna systems and related subjects over a period of 28 years, which has resulted in 44 publications in the technical literature, one current patent, and an M.Sc. thesis. The investigations have been grouped into 7 categories: - Log periodic antennas, - Antenna performance measurement techniques, - Spacecraft Antenna Systems, - Satcom Terminal Antennas, - Transmission lines and baluns, - High Radar Cross Secti...

  8. Monte Carlo techniques in diagnostic and therapeutic nuclear medicine

    International Nuclear Information System (INIS)

    Monte Carlo techniques have become one of the most popular tools in different areas of medical radiation physics following the development and subsequent implementation of powerful computing systems for clinical use. In particular, they have been extensively applied to simulate processes involving random behaviour and to quantify physical parameters that are difficult or even impossible to calculate analytically or to determine by experimental measurements. The use of the Monte Carlo method to simulate radiation transport turned out to be the most accurate means of predicting absorbed dose distributions and other quantities of interest in the radiation treatment of cancer patients using either external or radionuclide radiotherapy. The same trend has occurred for the estimation of the absorbed dose in diagnostic procedures using radionuclides. There is broad consensus in accepting that the earliest Monte Carlo calculations in medical radiation physics were made in the area of nuclear medicine, where the technique was used for dosimetry modelling and computations. Formalism and data based on Monte Carlo calculations, developed by the Medical Internal Radiation Dose (MIRD) committee of the Society of Nuclear Medicine, were published in a series of supplements to the Journal of Nuclear Medicine, the first one being released in 1968. Some of these pamphlets made extensive use of Monte Carlo calculations to derive specific absorbed fractions for electron and photon sources uniformly distributed in organs of mathematical phantoms. Interest in Monte Carlo-based dose calculations with β-emitters has been revived with the application of radiolabelled monoclonal antibodies to radioimmunotherapy. As a consequence of this generalized use, many questions are being raised primarily about the need and potential of Monte Carlo techniques, but also about how accurate it really is, what would it take to apply it clinically and make it available widely to the medical physics

  9. Low Noise Signal Processing Technique for Monopulse Pointing of DSN 34-meter Diameter Antennas

    Science.gov (United States)

    Gudim, M.; Gawronski, W.

    2000-01-01

    This paper describes a 31.8 - 32.3 GHz (Ka-band) monopulse antenna pointing system designed to meet a pointing precision requirement of a mean-radial-error (MRE) less than 1.5 milli-degrees for a 34-meter diameter antenna with a 17 milli-degree 3-dB beam-width, under windy conditions up to 15mph.

  10. Comparision of different diagnostic techniques against Fasciolosis in Buffaloes

    Directory of Open Access Journals (Sweden)

    Salam

    2009-08-01

    Full Text Available The present study was conducted to compare different diagnostic tests viz., Direct Smear (DS, Agar gel precipitation (AGP, Sedimentation (Sd, and Zinc Sulfate (ZnSO4 flotation for fasciolosis in dairy buffaloes as well as the economic losses due to fasciolosis. A total of 200 faecal samples were examined and DS, AGP, Sd, and ZnSO4 flotation techniques showed an overall prevalence of 2, 8, 5 and 4%, respectively. The highest agreement was observed between Sd and ZnSO4 (0.88, 95%CI; 0.74-1.02 followed by AGP and Sd (0.75, 95%CI; 0.62-0.88, ZnSO4 and DS (0.65,95%CI; 0.52-0.78, AGP and ZnSO4 (0.648, 95%CI; 0.51-0.77, DS and Sd (0.55, 95%CI; 0.43-0.68, and DSM and AGP (0.38, 95%CI; 0.27-0.48. By taking DS as a gold standard, all tests showed 100 percent sensitivity results and same trend was observed in case of negative predictive values (NPV. Highest specificity was shown by ZnSO4, followed by Sd and AGP. Similar trends were observed in the positive predictive values (PPV. Then, by taking AGP as gold standard, all tests showed 100 percent specificity and positive predictive values (PPV while, Sd showed highest sensitivity followed by ZnSO4 and AGP and similar trend was observed regarding NPV of tests. To this end, most effective test is AGP followed by Sd, ZnSO4 and DS method. Moreover, AGP is the most suitable method for diagnosing the fasciolosis in early stages. Total economic losses due to fasciolosis during three months (Oct. – Dec. 2004 were found very high i.e Rs. 1016400. [Vet. World 2009; 2(4.000: 129-132

  11. Diagnostic imaging techniques in Rubinstein-Taybi syndrome

    International Nuclear Information System (INIS)

    Both etiology and pathogenesis of Rubinstein-Taybi syndrome (RTS) are still questionable, even though a genetic factor seems to be certain. A typical face, psychomotor delay, and thumb and halluces abnormalities (big, prevalently short, and often 'spoon-like' toes) are the main characteristic patterns of RTS. Eight subjects (4 male and 3 female children aged 26 days-7 years, and a 31-year old woman, mother of 1 of the affected children) with different signs of RTS were studied over the last 3 years. The results are here reported, with a special emphasis on malformations detected with conventional radiography (Rx), Computerized Tomography (CT), and ultrasound (US). Evaluated parameters were thumbs and halluces (Rx), bone age and skeleton (Rx), cranium (Rx) and encephalon (US, CT), cryptochidism (US, CT), and urogical (Rx, US) and carciovascolar (US) system. Atypical face and psycomotor delay were found in all cases, while thumb and halluces abnormalities were observed only in 6 cases. Among several clinical signs of RTS, we found: severe (<3rd centile) bone maturation delay in 4 cases; skull volume reduction (<50th centile) in 3 subjects and microcrania in 4; skeletal abnormalities in 7 cases (5 of them positive for bilateral coxofemoral abnormalities); urinary tract (4 cases) and cardiovascular (3 cases) malformation; and cryptorcidism in 3 of 4 males. A case was diagnosed during neonatal period (within the first month of life) it was a rare case associated with a variant form of Dandy-Walker anomaly; semiologic similarities were observed between mother and daughter patients. X-rays, US and CT rarely play an important role in the diagnosis of RTS, considering the several clinical signs, mainly tha face, affecting the patients. However, diagnostic imaging techniques help diagnose hidden malformations and confirm and integrate clinical signs

  12. The diagnostic contribution of CT volumetric rendering techniques in routine practice

    International Nuclear Information System (INIS)

    Computed tomography (CT) volumetric rendering techniques such as maximum intensity projection (MIP), minimum intensity projection (MinIP), shaded surface display (SSD), volume rendering (VR), and virtual endoscopy (VE) provide added diagnostic capabilities. The diagnostic value of such reconstruction techniques is well documented in literature. These techniques permit the exploration of fine anatomical detail that would be difficult to evaluate using axial reconstructions alone. Although these techniques are now widely available, many radiologists are either unfamiliar with them or do not fully utilize their potential in daily clinical practice. This paper is intended to provide an overview of the most common CT volumetric rendering techniques and their practical use in everyday diagnostics

  13. Development of 2-D antenna array for microwave imaging reflectometry in LHD

    International Nuclear Information System (INIS)

    A 2-D antenna array for the Microwave Imaging Reflectometry (MIR) has been developed for the Large Helical Device (LHD). The MIR is a method of electron density diagnostics by the use of microwave radar techniques to obtain 2-D/3-D images of electron density fluctuations for the investigation of micro-turbulence and magneto-hydrodynamic instabilities in magnetically confined plasmas. The antenna array consists of five antennas in the toroidal direction and eight ones in the poloidal direction, respectively. As a test of an antenna element, a pyramidal horn antenna in the frequency range of 10-15 GHz was compared with the Yagi-Uda antenna. Based on the test results of the lower frequency antenna element, we manufactured a 2-D horn antenna array in the frequency range of 50-75 GHz. (author)

  14. Evolving imaging techniques in diagnostic strategies of pulmonary embolism.

    Science.gov (United States)

    Robert-Ebadi, Helia; Le Gal, Grégoire; Righini, Marc

    2016-04-01

    Modern non invasive diagnostic strategies for pulmonary embolism (PE) rely on the sequential use of clinical probability assessment, D-dimer measurement and thoracic imaging tests. Planar ventilation/perfusion (V/Q) scintigraphy was the cornerstone for more than two decades and has now been replaced by computed tomography pulmonary angiography (CTPA). Diagnostic strategies using CTPA are very safe to rule out PE and have been well validated in large prospective management outcome studies. With the widespread use of CTPA, concerns regarding radiation and overdiagnosis of PE have paved the way for investigating new diagnostic modalities. V/Q single photon emission tomography has arisen as a highly accurate test and a potential alternative to CTPA. However, prospective management outcome studies are still lacking and are warranted before implementation in everyday clinical practice. PMID:26691634

  15. A Combined FEM/MoM/GTD Technique To Analyze Elliptically Polarized Cavity-Backed Antennas With Finite Ground Plane

    Science.gov (United States)

    Reddy, C. J.; Deshpande, M. D.; Fralick, D. T.; Cockrell, C. R.; Beck, F. B.

    1996-01-01

    Radiation pattern prediction analysis of elliptically polarized cavity-backed aperture antennas in a finite ground plane is performed using a combined Finite Element Method/Method of Moments/Geometrical Theory of Diffraction (FEM/MoM/GTD) technique. The magnetic current on the cavity-backed aperture in an infinite ground plane is calculated using the combined FEM/MoM analysis. GTD, including the slope diffraction contribution, is used to calculate the diffracted fields caused by both soft and hard polarizations at the edges of the finite ground plane. Explicit expressions for regular diffraction coefficients and slope diffraction coefficients are presented. The slope of the incident magnetic field at the diffraction points is derived and analytical expressions are presented. Numerical results for the radiation patterns of a cavity-backed circular spiral microstrip patch antenna excited by a coaxial probe in a finite rectangular ground plane are computed and compared with experimental results.

  16. The diagnostic contribution of CT volumetric rendering techniques in routine practice

    OpenAIRE

    Perandini Simone; Faccioli N; Zaccarella A; Re T; Mucelli R

    2010-01-01

    Computed tomography (CT) volumetric rendering techniques such as maximum intensity projection (MIP), minimum intensity projection (MinIP), shaded surface display (SSD), volume rendering (VR), and virtual endoscopy (VE) provide added diagnostic capabilities. The diagnostic value of such reconstruction techniques is well documented in literature. These techniques permit the exploration of fine anatomical detail that would be difficult to evaluate using axial reconstructions alone. Although thes...

  17. A DEMO relevant fast wave current drive high harmonic antenna exploiting the high impedance technique

    Science.gov (United States)

    Milanesio, D.; Maggiora, R.

    2015-12-01

    Ion Cyclotron (IC) antennas are routinely adopted in most of the existing nuclear fusion experiments, even though their main goal, i.e. to couple high power to the plasma (MW), is often limited by rather severe drawbacks due to high fields on the antenna itself and on the unmatched part of the feeding lines. In addition to the well exploited auxiliary ion heating during the start-up phase, some non-ohmic current drive (CD) at the IC range of frequencies may be explored in view of the DEMO reactor. In this work, we suggest and describe a compact high frequency DEMO relevant antenna, based on the high impedance surfaces concept. High-impedance surfaces are periodic metallic structures (patches) usually displaced on top of a dielectric substrate and grounded by means of vertical posts embedded inside the dielectric, in a mushroom-like shape. These structures present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. After a general introduction on the properties of high impedance surfaces, we analyze, by means of numerical codes, a dielectric based and a full metal solution optimized to be tested and benchmarked on the FTU experiment fed with generators at 433MHz.

  18. A DEMO relevant fast wave current drive high harmonic antenna exploiting the high impedance technique

    Energy Technology Data Exchange (ETDEWEB)

    Milanesio, D., E-mail: daniele.milanesio@polito.it; Maggiora, R. [Politecnico di Torino, Dipartimento di Elettronica e Telecomunicazioni (DET), Torino (Italy)

    2015-12-10

    Ion Cyclotron (IC) antennas are routinely adopted in most of the existing nuclear fusion experiments, even though their main goal, i.e. to couple high power to the plasma (MW), is often limited by rather severe drawbacks due to high fields on the antenna itself and on the unmatched part of the feeding lines. In addition to the well exploited auxiliary ion heating during the start-up phase, some non-ohmic current drive (CD) at the IC range of frequencies may be explored in view of the DEMO reactor. In this work, we suggest and describe a compact high frequency DEMO relevant antenna, based on the high impedance surfaces concept. High-impedance surfaces are periodic metallic structures (patches) usually displaced on top of a dielectric substrate and grounded by means of vertical posts embedded inside the dielectric, in a mushroom-like shape. These structures present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. After a general introduction on the properties of high impedance surfaces, we analyze, by means of numerical codes, a dielectric based and a full metal solution optimized to be tested and benchmarked on the FTU experiment fed with generators at 433MHz.

  19. A DEMO relevant fast wave current drive high harmonic antenna exploiting the high impedance technique

    International Nuclear Information System (INIS)

    Ion Cyclotron (IC) antennas are routinely adopted in most of the existing nuclear fusion experiments, even though their main goal, i.e. to couple high power to the plasma (MW), is often limited by rather severe drawbacks due to high fields on the antenna itself and on the unmatched part of the feeding lines. In addition to the well exploited auxiliary ion heating during the start-up phase, some non-ohmic current drive (CD) at the IC range of frequencies may be explored in view of the DEMO reactor. In this work, we suggest and describe a compact high frequency DEMO relevant antenna, based on the high impedance surfaces concept. High-impedance surfaces are periodic metallic structures (patches) usually displaced on top of a dielectric substrate and grounded by means of vertical posts embedded inside the dielectric, in a mushroom-like shape. These structures present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. After a general introduction on the properties of high impedance surfaces, we analyze, by means of numerical codes, a dielectric based and a full metal solution optimized to be tested and benchmarked on the FTU experiment fed with generators at 433MHz

  20. Tunable diode laser spectroscopy as a technique for combustion diagnostics

    Science.gov (United States)

    Bolshov, M. A.; Kuritsyn, Yu. A.; Romanovskii, Yu. V.

    2015-04-01

    Tunable diode laser absorption spectroscopy (TDLAS) has become a proven method of rapid gas diagnostics. In the present review an overview of the state of the art of TDL-based sensors and their applications for measurements of temperature, pressure, and species concentrations of gas components in harsh environments is given. In particular, the contemporary tunable diode laser systems, various methods of absorption detection (direct absorption measurements, wavelength modulation based phase sensitive detection), and relevant algorithms for data processing that improve accuracy and accelerate the diagnostics cycle are discussed in detail. The paper demonstrates how the recent developments of these methods and algorithms made it possible to extend the functionality of TDLAS in the tomographic imaging of combustion processes. Some prominent examples of applications of TDL-based sensors in a wide range of practical combustion aggregates, including scramjet engines and facilities, internal combustion engines, pulse detonation combustors, and coal gasifiers, are given in the final part of the review.

  1. Combining classification techniques with Kalman filters for aircraft engine diagnostics

    OpenAIRE

    Dewallef, Pierre; Romessis, C.; Léonard, Olivier; Mathioudakis, K.

    2006-01-01

    A diagnostic method consisting of a combination of Kalman filters and Bayesian Belief Network (BBN) is presented. A soft-constrained Kalman filter uses a priori information derived by a BBN at each time step, to derive estimations of the unknown health parameters. The resulting algorithm hers improved identification capability in comparison to the stand-alone Kalman filter. The paper focuses on a way of combining the information produced by the BBN with the Kalman filter. An extensive set of ...

  2. Optical Imaging Techniques for Point-of-care Diagnostics

    OpenAIRE

    Zhu, Hongying; Isikman, Serhan O.; Mudanyali, Onur; Greenbaum, Alon; Ozcan, Aydogan

    2012-01-01

    Improving the access to effective and affordable healthcare has long been a global endeavor. In this quest, the development of cost-effective and easy-to-use medical testing equipment that enable rapid and accurate diagnosis is essential to reduce the time and costs associated with healthcare services. To this end, point-of-care (POC) diagnostics plays a crucial role in healthcare delivery in both the developed and developing countries by bringing medical testing to patients, or to sites near...

  3. Comparison of different diagnostic techniques in Plasmodium falciparum cerebral malaria

    Directory of Open Access Journals (Sweden)

    Fatima Shujatullah, Abida Malik, Haris M. Khan & Ashraf Malik

    2006-12-01

    Full Text Available Background & objectives: Plasmodium falciparum cerebral malaria remains a major health problemin India. The efficacy of treatment of cerebral malaria lies in its early diagnosis through rapid diagnosticmethods. ParaSights-F test detects HRP-2 antigen secreted by parasitised red blood cells andquantitative buffy coat assay (QBC is examination of buffy coat for the presence of malarial parasitestained with acridine orange. This study was performed to evaluate the effectiveness of ParaSight-F test and QBC assay as diagnostic methods in the patients of cerebral malaria.Methods: Fifty clinically diagnosed patients of cerebral malaria were included in the study.ParaSight-F test, QBC and conventional blood smear examination was done. Patients who were incoma and there were no obvious features of bacterial or viral etiology were investigated for cerebralmalaria by these diagnostic methods.Results: ParaSight-F test, QBC and peripheral blood smears were examined. Patients were followedupfor signs of clinical recovery. ParaSight-F test was positive in 47 patients, QBC in 46 while bloodsmear examination was positive in 28 cases.Interpretation & conclusion: Sensitivity and specificity of ParaSight-F test were found to be 96.6 and94% while QBC showed 97.8 and 100% respectively. ParaSight-F test and QBC were found to be novelmethods for diagnosis of cerebral malaria especially in the cases where diagnosis can not be made byconventional blood smear examination due to low parasitaemia. These rapid diagnostic methods helpin early therapeutic intervention.

  4. Tunable diode laser spectroscopy as a technique for combustion diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Bolshov, M.A., E-mail: bolshov@isan.troitsk.ru; Kuritsyn, Yu.A.; Romanovskii, Yu.V.

    2015-04-01

    Tunable diode laser absorption spectroscopy (TDLAS) has become a proven method of rapid gas diagnostics. In the present review an overview of the state of the art of TDL-based sensors and their applications for measurements of temperature, pressure, and species concentrations of gas components in harsh environments is given. In particular, the contemporary tunable diode laser systems, various methods of absorption detection (direct absorption measurements, wavelength modulation based phase sensitive detection), and relevant algorithms for data processing that improve accuracy and accelerate the diagnostics cycle are discussed in detail. The paper demonstrates how the recent developments of these methods and algorithms made it possible to extend the functionality of TDLAS in the tomographic imaging of combustion processes. Some prominent examples of applications of TDL-based sensors in a wide range of practical combustion aggregates, including scramjet engines and facilities, internal combustion engines, pulse detonation combustors, and coal gasifiers, are given in the final part of the review. - Highlights: • Overview of modern TDL-based sensors for combustion • TDL systems, methods of absorption detection and algorithms of data processing • Prominent examples of TDLAS diagnostics of the combustion facilities • Extension of the TDLAS on the tomographic imaging of combustion processes.

  5. Tunable diode laser spectroscopy as a technique for combustion diagnostics

    International Nuclear Information System (INIS)

    Tunable diode laser absorption spectroscopy (TDLAS) has become a proven method of rapid gas diagnostics. In the present review an overview of the state of the art of TDL-based sensors and their applications for measurements of temperature, pressure, and species concentrations of gas components in harsh environments is given. In particular, the contemporary tunable diode laser systems, various methods of absorption detection (direct absorption measurements, wavelength modulation based phase sensitive detection), and relevant algorithms for data processing that improve accuracy and accelerate the diagnostics cycle are discussed in detail. The paper demonstrates how the recent developments of these methods and algorithms made it possible to extend the functionality of TDLAS in the tomographic imaging of combustion processes. Some prominent examples of applications of TDL-based sensors in a wide range of practical combustion aggregates, including scramjet engines and facilities, internal combustion engines, pulse detonation combustors, and coal gasifiers, are given in the final part of the review. - Highlights: • Overview of modern TDL-based sensors for combustion • TDL systems, methods of absorption detection and algorithms of data processing • Prominent examples of TDLAS diagnostics of the combustion facilities • Extension of the TDLAS on the tomographic imaging of combustion processes

  6. Pattern-recognition techniques applied to performance monitoring of the DSS 13 34-meter antenna control assembly

    Science.gov (United States)

    Mellstrom, J. A.; Smyth, P.

    1991-01-01

    The results of applying pattern recognition techniques to diagnose fault conditions in the pointing system of one of the Deep Space network's large antennas, the DSS 13 34-meter structure, are discussed. A previous article described an experiment whereby a neural network technique was used to identify fault classes by using data obtained from a simulation model of the Deep Space Network (DSN) 70-meter antenna system. Described here is the extension of these classification techniques to the analysis of real data from the field. The general architecture and philosophy of an autonomous monitoring paradigm is described and classification results are discussed and analyzed in this context. Key features of this approach include a probabilistic time-varying context model, the effective integration of signal processing and system identification techniques with pattern recognition algorithms, and the ability to calibrate the system given limited amounts of training data. Reported here are recognition accuracies in the 97 to 98 percent range for the particular fault classes included in the experiments.

  7. Substrate integrated antennas and arrays

    CERN Document Server

    Cheng, Yu Jian

    2015-01-01

    Substrate Integrated Antennas and Arrays provides a single source for cutting-edge information on substrate integrated circuits (SICs), substrate integrated waveguide (SIW) feeding networks, SIW slot array antennas, SIC traveling-wave antennas, SIW feeding antennas, SIW monopulse antennas, and SIW multibeam antennas. Inspired by the author's extensive research, this comprehensive book:Describes a revolutionary SIC-based antenna technique with the potential to replace existing antenna technologiesExamines theoretical and experimental results connected to electrical and mechanical performanceExp

  8. Diagnostic of dense plasmas by infrared schlieren and absorption techniques

    International Nuclear Information System (INIS)

    In dense arc plasmas (T approximately 12 500 K, Nsub(e) approximately 1-6 x 1017 cm -3) the high continuum emission, the strong broadening and self-absorption of the lines, as well as more fundamental problems of non-ideality (Nsub(D) 8/3πNsub(e)lambdasub(D)3 not >> 1) renders the usual diagnostics difficult. Infrared schlieren is shown to be a good alternative. Results are in good agreement for electron density with Stark broadening measurements using Griem's data. Absorption measurements also show that the plasma does not exhibit abnormal behaviour compared to the usual case (Nsub(D) >> 1). (author)

  9. Reliability of diagnostic techniques for Erwinia amylovora, the causative agent of fire blight disease

    Czech Academy of Sciences Publication Activity Database

    Kokošková, B.; Mráz, Ivan

    2005-01-01

    Roč. 50, - (2005), s. 217-221. ISSN 0015-5632 Institutional research plan: CEZ:AV0Z5051902 Keywords : diagnostic techniques * plant diseases Subject RIV: EE - Microbiology, Virology Impact factor: 0.918, year: 2005

  10. Contributions to the course and workshop on basic and advanced fusion plasmas diagnostic techniques

    International Nuclear Information System (INIS)

    Three papers read at the Course and workshop on basic and advanced fusion plasmas diagnostic techniques held in Varenna from 3 to 13 September 1986 and prepared by searchers of Fusion Department of ENEA are reported

  11. Localization of Aurorae with 10 m High Power Radar Technique, using a Rotating Antenna

    OpenAIRE

    Hellgren, Gösta; Meos, Johan

    2011-01-01

    The paper describes the 10 m high power recorder with a rotating antenna that is used since May 1951 for the localization of aurorae at the Radio Wave Propagation Laboratory of the Kiruna Geophysical Observatory (67.8° N, 20.5° E). Continuous observations during the time May 1951–March 1952 have disclosed periods of auroral activity. The preliminary results from these observations indicate that there is a good correlation between the auroral activity, the magnetic activity, and ...

  12. Interference Mitigation Technique Using Active Spaceborne Sensor Antenna in EESS (Active) and Space Research Service (Active) for Use in 500 MHz Bandwidth Near 9.6 GHz

    Science.gov (United States)

    Huneycutt, Bryan L.

    2005-01-01

    This document presents an interference mitigation technique using the active spaceborne sensor SAR3 antenna in the Earth Exploration-Satellite Service (active) and Space Research Service (active) for use in a 500 MHz bandwidth near 9.6 GHz. The purpose of the document is present antenna designs which offer lower sidelobes and faster rolloff in the sidelobes which in turn mitigates the interference to other services from the EESS (active) and SRS (active) sensors.

  13. Imaging in intensive care medicine. Techniques, indications, diagnostic signs. Pt. 1

    International Nuclear Information System (INIS)

    The intensive care medicine also profits from the rapid progress made in the field of diagnostic radiology: The modern techniques available today permit to come to a conclusive diagnosis much faster than before, provided that the doctors keep abreast with the chances and restraints of the diagnostic imaging methods applicable in intensive care medicine. This contribution presents a topical survey of the potentials of the various imaging methods, taking as a starting point the essential clinical approaches and indications as well as problems involved. The diagnostic signs are discussed, together with recommended diagnostic procedures. (orig./CB)

  14. Action Research to Improve the Learning Space for Diagnostic Techniques

    Directory of Open Access Journals (Sweden)

    Ellen Ariel

    2015-08-01

    Full Text Available The module described and evaluated here was created in response to perceived learning difficulties in diagnostic test design and interpretation for students in third-year Clinical Microbiology. Previously, the activities in lectures and laboratory classes in the module fell into the lower cognitive operations of “knowledge” and “understanding.” The new approach was to exchange part of the traditional activities with elements of interactive learning, where students had the opportunity to engage in deep learning using a variety of learning styles. The effectiveness of the new curriculum was assessed by means of on-course student assessment throughout the module, a final exam, an anonymous questionnaire on student evaluation of the different activities and a focus group of volunteers. Although the new curriculum enabled a major part of the student cohort to achieve higher pass grades (p < 0.001, it did not meet the requirements of the weaker students, and the proportion of the students failing the module remained at 34%. The action research applied here provided a number of valuable suggestions from students on how to improve future curricula from their perspective. Most importantly, an interactive online program that facilitated flexibility in the learning space for the different reagents and their interaction in diagnostic tests was proposed. The methods applied to improve and assess a curriculum refresh by involving students as partners in the process, as well as the outcomes, are discussed.

  15. Action Research to Improve the Learning Space for Diagnostic Techniques.

    Science.gov (United States)

    Ariel, Ellen; Owens, Leigh

    2015-12-01

    The module described and evaluated here was created in response to perceived learning difficulties in diagnostic test design and interpretation for students in third-year Clinical Microbiology. Previously, the activities in lectures and laboratory classes in the module fell into the lower cognitive operations of "knowledge" and "understanding." The new approach was to exchange part of the traditional activities with elements of interactive learning, where students had the opportunity to engage in deep learning using a variety of learning styles. The effectiveness of the new curriculum was assessed by means of on-course student assessment throughout the module, a final exam, an anonymous questionnaire on student evaluation of the different activities and a focus group of volunteers. Although the new curriculum enabled a major part of the student cohort to achieve higher pass grades (p learning space for the different reagents and their interaction in diagnostic tests was proposed. The methods applied to improve and assess a curriculum refresh by involving students as partners in the process, as well as the outcomes, are discussed. Journal of Microbiology & Biology Education. PMID:26753024

  16. Analysis of injuries to the proximal diagnostic - Diagnostic difficulties, visualisation techniques

    International Nuclear Information System (INIS)

    Fractures of the proximal tibia involve the lateral condyle in 75-80% of cases. Intercondylar eminence fractures and avulsion injuries involve the tibial side of the attachment of the cruciate ligaments. The aim of this study was an analysis of injuries to the proximal tibia. In our opinion the best diagnostic method was CT investigation made according to a specified protocol and analyzed with radiographic images in two projections. MR was an additional method in problematic and complicated cases, such as subtle fractures of the tibial plateau with cartilage damage or when the CT was not diagnostic. A radiologist and an orthopedic surgeon analyzed the radiographic, CT, and MR images of 23 patients from both the technical and the diagnostic aspect. Partial fracture of the tibial plateau was diagnosed in 12 cases, including fractures of the lateral condyle in 11 cases, and isolated fractures of the lateral condyle in 4 cases. Fracture of the medial condyle was diagnosed in 1 case. Isolated avulsional fractures of the intercondylar eminentia were diagnosed in 2 cases. Multi fragmentary fractures of the tibial plateau and metaphysis were diagnosed in 6 cases. (author)

  17. Dose classification scheme for digital imaging techniques in diagnostic radiology

    International Nuclear Information System (INIS)

    Purpose: image quality in diagnostic radiology is determined in crucial extent by the signal-noise-ratio, which is proportional to the applied x-ray dose. Onward technological developments in the diagnostic radiology are therefore frequently connected with a dose increase, which subjectively is hardly or even not perceptible. The aim of this work was to define reproducible standards for image quality as a function of dose and expected therapeutical consequence in case of computed tomography of the paranasal sinuses and the upper and lower jaw (dental CT), whereby practical-clinical purposes are considered. Materials and methods: the image quality of computed tomography of the paranasal sinuses and dental CT was determined by standard deviation of the CT-numbers (pixel noise) in a region of interest of the phantom of American Association of Physicists in Medicine (AAPM phantom) and additionally in the patients CT images. The diagnostic quality of the examination was classified on the basis of patients CT images in three dose levels (low dose, standard dose and high dose). Results: the pixel noise of CT of the paranasal sinuses with soft tissue reconstruction amounts to 19.3 Hounsfield units (HU) for low dose, 8.8 HU for standard dose, and below 8 HU for high dose. The pixel noise of the dental CT with bone (high resolution) reconstruction amounts to 344 HU for low dose, 221 HU for standard dose, and below 200 HU for high dose. Suitable indications for low dose CT are the scanning of body regions with high contrast differences, like the bony delimitations of air-filled spaces of the facial bones, and radiological follow-up examinations with dedicated questions such as axis determination in dental implantology, as well as the images of objects with small diameter such as in case of children. The standard dose CT can be recommended for all cases, in which precise staging of the illness plays an indispensable role for the diagnosis and therapy planning. With high dose

  18. Influence of diagnostic quality scanning technique with CR mammography

    International Nuclear Information System (INIS)

    Image quality criteria laid down in the Spanish Protocol of Control of quality in Radiology (PECCR) to a team of mammography with CR imaging system are applied in this work and evaluated the dosimetry impact implied by the modification of the technique of exposure required for the fulfilment of those criteria. Is also analyzes the impact on the image quality of the new radiographic technique, evaluated by three radiologists. (Author)

  19. Smart antennas in aerospace applications

    OpenAIRE

    Verpoorte, Jaco; Schippers, Harmen; Roeloffzen, Chris G.H.; Marpaung, David A.I.

    2010-01-01

    The interest in Smart Antennas for aerospace applications is growing. This paper describes smart antennas which can be used on aircraft. Two aerospace applications are discussed in more detail: a phased array antenna with optical beam forming and a large vibrating phased array antenna with electronic compensation techniques.

  20. Beam diagnostic techniques, observations and comparison with theory

    International Nuclear Information System (INIS)

    This paper presents the classes of the different methods of beam diagnostics available in modern storage rings. The first two use the near-field of the beam measured by the position monitors. The optical functions emdash betatron phase advances and beta functions emdash are obtained by exciting a betatron oscillation and measuring its phase and amplitude at the beam position monitors around the ring. Modern readout electronics, which memorize the readings taken in successive turns, are particularly well suited for this method. A second group of measurements is concerned with the properties of the beam itself. The frequency distribution of the particles can directly be deduced from the beam response to a harmonic excitation. Such measurements give also the beam stability and the impedance of the beam surroundings. The third class observes the far-field of the beam emitted as synchrotron radiation. Using this radiation for imaging or measuring its angular divergence gives the transverse beam dimensions

  1. Advanced Antenna Techniques and High Order Sectorization with Novel Network Tessellation for Enhancing Macro Cell Capacity in DC-HSDPA Network

    Directory of Open Access Journals (Sweden)

    Muhammad Usman Sheikh

    2013-10-01

    Full Text Available Mobile operators commonly use macro cells with traditional wide beam antennas for wider coverage in thecell, but future capacity demands cannot be achieved by using them only. It is required to achieve maximumpractical capacity from macro cells by employing higher order sectorization and by utilizing all possibleantenna solutions including smart antennas. This paper presents enhanced tessellation for 6-sector sitesand proposes novel layout for 12-sector sites. The main target of this paper is to compare the performanceof conventional wide beam antenna, switched beam smart antenna, adaptive beam antenna and differentnetwork layouts in terms of offering better received signal quality and user throughput. Splitting macro cellinto smaller micro or pico cells can improve the capacity of network, but this paper highlights theimportance of higher order sectorization and advance antenna techniques to attain high Signal toInterference plus Noise Ratio (SINR, along with improved network capacity. Monte Carlo simulations atsystem level were done for Dual Cell High Speed Downlink Packet Access (DC-HSDPA technology withmultiple (five users per Transmission Time Interval (TTI at different Intersite Distance (ISD. Theobtained results validate and estimate the gain of using smart antennas and higher order sectorization withproposed network layout.

  2. Electro-optic techniques in electron beam diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    van Tilborg, Jeroen; Toth, Csaba; Matlis, Nicholas; Plateau, Guillaume; Leemans, Wim

    2011-06-17

    Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

  3. Electro-optic techniques in electron beam diagnostics

    International Nuclear Information System (INIS)

    Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

  4. The diagnostic contribution of CT volumetric rendering techniques in routine practice

    Directory of Open Access Journals (Sweden)

    Perandini Simone

    2010-01-01

    Full Text Available Computed tomography (CT volumetric rendering techniques such as maximum intensity projection (MIP, minimum intensity projection (MinIP, shaded surface display (SSD, volume rendering (VR, and virtual endoscopy (VE provide added diagnostic capabilities. The diagnostic value of such reconstruction techniques is well documented in literature. These techniques permit the exploration of fine anatomical detail that would be difficult to evaluate using axial reconstructions alone. Although these techniques are now widely available, many radiologists are either unfamiliar with them or do not fully utilize their potential in daily clinical practice. This paper is intended to provide an overview of the most common CT volumetric rendering techniques and their practical use in everyday diagnostics.

  5. Advances in transducers and techniques for diagnostic ultrasound

    International Nuclear Information System (INIS)

    Until recently, diagnostic imaging systems have remained stable with familiar modes to be measured. Emerging technologies are changing the measurement landscape rapidly. New developments are reviewed as well as those in research to examine the possible measurement challenges of the future. Improved focusing and steering are available with 1.5 D, multiple subaperture arrays, fully populated and sparse 2D arrays, and CMUT arrays. Encoded excitation pulses provide unique consideration. High frequency and special purpose arrays stretch the present limits of measurement bandwidth and resolution. Special auxiliary pulses and pulse sequences are being proposed for controlling, manipulating and destroying contrast agents and specially formulated therapeutic contrast agents. Improved harmonic imaging can involve multiple phased pulses as well as types of encoding. Active tissue characterization methods may include a means for tissue deformation as well as aberration correction. Imaging systems are undergoing a dramatic revolution in terms of their architecture, complexity, miniaturization and the role of software in image formation. These developments will be examined in terms of field distribution, pressure levels, pulse sequencing, waveforms and measurement

  6. Giardiasis in Endoscopy Patients: A Comparison of Diagnostic Techniques

    OpenAIRE

    1990-01-01

    The results of a study comparing techniques for diagnosis of giardiasis during endoscopy are presented. Methods of diagnosis included examination of duodenal biopsy impression smears, culture of both biopsies and aspirates, and examination of preserved aspirate. Giardiasis was diagnosed in three of 80 patients; in each case the impression smear was positive. Cultures of duodenal biopsies were positive in two patients; in the third patient a biopsy was not available. The preserved aspirate was...

  7. Unbiased stereologic techniques for practical use in diagnostic histopathology

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt

    1995-01-01

    Grading of malignancy by the examination of morphologic and cytologic details in histologic sections from malignant neoplasms is based exclusively on qualitative features, associated with significant subjectivity, and thus rather poor reproducibility. The traditional way of malignancy grading may...... therefore not be optimal regarding the scientific and clinical value in selecting specific therapy and making prognostic forecast for the individual patient with a solid cancer. A lot of examples in the international literature document the urgent need for replacing morphologically based techniques by...

  8. Development of fault diagnostic technique using reactor noise analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Ho; Kim, J. S.; Oh, I. S.; Ryu, J. S.; Joo, Y. S.; Choi, S.; Yoon, D. B

    1999-04-01

    The ultimate goal of this project is to establish the analysis technique to diagnose the integrity of reactor internals using reactor noise. The reactor noise analyses techniques for the PWR and CANDU NPP(Nuclear Power Plants) were established by which the dynamic characteristics of reactor internals and SPND instrumentations could be identified, and the noise database corresponding to each plant(both Korean and foreign one) was constructed and compared. Also the change of dynamic characteristics of the Ulchin 1 and 2 reactor internals were simulated under presumed fault conditions. Additionally portable reactor noise analysis system was developed so that real time noise analysis could directly be able to be performed at plant site. The reactor noise analyses techniques developed and the database obtained from the fault simulation, can be used to establish a knowledge based expert system to diagnose the NPP's abnormal conditions. And the portable reactor noise analysis system may be utilized as a substitute for plant IVMS(Internal Vibration Monitoring System). (author)

  9. X-ray and radionuclide diagnostic techniques for osteoporosis

    International Nuclear Information System (INIS)

    Available data on the use of X-ray and radionuclide techniques in the diagnosis of osteoporosis are generalized. It is shown that because of the considerable spreading of osteoporosis the real demand for wide osteodensitometry performance exists. Absorptiometry may be widely used in clinic practice due to its accuracy, reproducibility, low cost, low radiation doses. Quantitative computerized tomography permits to obtain the absolute values of bone tissue density. Osteodensitometry plays an important role in identification and treatment of osteoporosis, promotes the prophylaxis of traumatism

  10. Analysis of diagnostic calorimeter data by the transfer function technique

    Energy Technology Data Exchange (ETDEWEB)

    Delogu, R. S., E-mail: rita.delogu@igi.cnr.it; Pimazzoni, A.; Serianni, G. [Consorzio RFX, Corso Stati Uniti, 35127 Padova (Italy); Poggi, C.; Rossi, G. [Università degli Studi di Padova, Via 8 Febbraio 1848, 35122 Padova (Italy)

    2016-02-15

    This paper describes the analysis procedure applied to the thermal measurements on the rear side of a carbon fibre composite calorimeter with the purpose of reconstructing the energy flux due to an ion beam colliding on the front side. The method is based on the transfer function technique and allows a fast analysis by means of the fast Fourier transform algorithm. Its efficacy has been tested both on simulated and measured temperature profiles: in all cases, the energy flux features are well reproduced and beamlets are well resolved. Limits and restrictions of the method are also discussed, providing strategies to handle issues related to signal noise and digital processing.

  11. Antennas from theory to practice

    CERN Document Server

    Huang, Yi

    2008-01-01

    Practical, concise and complete reference for the basics of modern antenna design Antennas: from Theory to Practice discusses the basics of modern antenna design and theory. Developed specifically for engineers and designers who work with radio communications, radar and RF engineering, this book offers practical and hands-on treatment of antenna theory and techniques, and provides its readers the skills to analyse, design and measure various antennas. Key features: Provides thorough coverage on the basics of transmission lines, radio waves and propag

  12. A Hybrid Neural Network-Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2001-01-01

    In this paper, a model-based diagnostic method, which utilizes Neural Networks and Genetic Algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and Genetic Algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of Genetic Algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show this approach is promising for reliable diagnostics of aircraft engines.

  13. Cardiovascular procedures/diagnostic techniques and therapeutic procedures

    International Nuclear Information System (INIS)

    This book covers the technical and therapeutic aspects of cardiovascular procedures in immense detail. There are large and appropriate diagrams and tables. The topics of the chapters are tools for catheterization, venous access, arterial access, hemodynamic monitoring, cardiac catheterization and coronary arteriography, ergonovine provocation testing for coronary artery spasm, pulmonary angiography, endomyocredial biopsy, electrophysiologic studies, pericardiocentesis and drainage, intraaortic balloon pumping, direct current cardioversion and defibrilaltion, pacemaker implantation of the automatic implantable cardioverter/defibrillator, coronary angioplasty, thrombolytic therapy, transluminal catheter extraction and resolution of intracardiac catheter knots, cardiopulmonary resuscitation, contrast media toxicity and allergic reactions, radiation hazards, and medicolegal concerns. An appendix and index follow these chapters. In general, each chapter covers historical aspects, indications, complications, techniques, and preoperative and postoperative care

  14. Indirect lymphangiography as a diagnostic technique of lymphedema

    International Nuclear Information System (INIS)

    Indirect lymphangiography is a new technique for the evaluation of lymphedema. The major advantage of the indirect lymphangiography is its noninvasiveness using nonionic water-soluble contrast media. It could be performed by injecting contrast media intradermally, so unnecessary skin incision could be avoided. Few manuscripts were reported concerning indirect lymphangiography in the all over the world so far. We now report our observation of indirect lymphangiography using lsovist 240 (Schering A G). We have encountered 3 primary hypoplastic lymphedema of lower extremity and 2 secondary lymphedema of upper extremity. The results were as follows: 1. In 3 primary hypoplastic lymphedema, lymphatics were few and tiny. The injected contrast media showed localized and prolonged stasis. 2. In 2 secondary hypoplastic lymphedema, contrast media was easily absorbed in numerous and ectatic lymphatics. 3. Indirect lymphangiography is a satisfactory method to see the pathologic changes of lymphatics in our 5 cases.

  15. Mild cognitive impairment. Diagnostic value of different MR techniques

    International Nuclear Information System (INIS)

    In view of an increasingly aging population the prevalence of dementia is also expected to increase rapidly. As well as clinical, neuropsychological and laboratory procedures magnetic resonance imaging (MRI) plays an important role in the early diagnosis of dementia which is important in the precursor stage of mild cognitive impairment (MCI). On the one hand this stage is associated with an increased risk of dementia and on the other hand an early treatment in this stage could attenuate development of the disease. In addition to morphological changes different functional MRI techniques can help in the early diagnosis of dementia and the precursor stages. Moreover, it is important to detect those MCI patients who are at particularly risk for developing dementia. In the differentiation of converters to non-converters initial studies suggest that particularly voxel-based morphometry, MR spectroscopy and diffusion tensor imaging can provide important additional information. (orig.)

  16. Coherent Rayleigh-Brillouin scattering as a flow diagnostic technique

    Energy Technology Data Exchange (ETDEWEB)

    Graul, J. S.; Lilly, T. C. [Department of Mechanical and Aerospace Engineering, University of Colorado Colorado Springs, 1420 Austin Bluffs Parkway, Colorado Springs, CO 80918 (United States)

    2014-12-09

    Broadband coherent Rayleigh-Brillouin scattering (CRBS) was used to measure translational gas temperatures for nitrogen at the ambient pressure of 0.8 atm using a purpose-built Fabry-Perot etalon spectrometer. Temperatures derived from the CRBS spectral analysis were compared with experimentally-measured temperatures, and were found to be, on average, within 2% of the experimentally-measured value. Axial flow velocities from a double jet at a pressure ratio of 0.38 were also measured by looking at the Doppler shift of the CRBS line shape. With recent developments in chirped laser technology and the capacity of CRBS to simultaneously provide thermodynamic and bulk flow information, the CRBS line shape acquisition and analysis technique presented here may allow for future time-resolved, characterization of aerospace flows.

  17. Further possibilities of application of digital subtraction technique in neuroradiological diagnostics

    International Nuclear Information System (INIS)

    The article presents, as methods that can be used in addition to digital subtraction angiography, ventriculography, myelography, discography as well as control examinations of shunts and port systems to widen the scope of digital subtraction techniques (DST) in neuroradiological diagnostics. Besides the reduction of amount and concentration of contrast media, more comprehensive and better diagnostic results were achieved for all examination methods with regard to the functional and dynamic aspects, the spatial resolution being of comparable quality. (orig.)

  18. Auto Diagnostics of Lung Nodules Using Minimal Characteristics Extraction Technique

    Directory of Open Access Journals (Sweden)

    Diego M. Peña

    2016-03-01

    Full Text Available Computer-aided detection (CAD systems provide useful tools and an advantageous process to physicians aiming to detect lung nodules. This paper develops a method composed of four processes for lung nodule detection. The first step employs image acquisition and pre-processing techniques to isolate the lungs from the rest of the body. The second stage involves the segmentation process using a 2D algorithm to affect every layer of a scan eliminating non-informative structures inside the lungs, and a 3D blob algorithm associated with a connectivity algorithm to select possible nodule shape candidates. The combinations of these algorithms efficiently eliminate the high rates of false positives. The third process extracts eight minimal representative characteristics of the possible candidates. The final step utilizes a support vector machine for classifying the possible candidates into nodules and non-nodules depending on their features. As the objective is to find nodules bigger than 4mm, the proposed approach demonstrated quite encouraging results. Among 65 computer tomography (CT scans, 94.23% of sensitivity and 84.75% in specificity were obtained. The accuracy of these two results was 89.19% taking into consideration that 45 scans were used for testing and 20 for training. The rate of false positives was 0.2 per scan.

  19. Case-based reasoning diagnostic technique based on multi-attribute similarity

    Energy Technology Data Exchange (ETDEWEB)

    Makoto, Takahashi [Tohoku University, Miyagi (Japan); Akio, Gofuku [Okayama University, Okayamaa (Japan)

    2014-08-15

    Case-based diagnostic technique has been developed based on the multi-attribute similarity. Specific feature of the developed system is to use multiple attributes of process signals for similarity evaluation to retrieve a similar case stored in a case base. The present technique has been applied to the measurement data from Monju with some simulated anomalies. The results of numerical experiments showed that the present technique can be utilizes as one of the methods for a hybrid-type diagnosis system.

  20. Urine sampling techniques in symptomatic primary-care patients: a diagnostic accuracy review

    OpenAIRE

    Holm, Anne; Aabenhus, Rune

    2016-01-01

    Background Choice of urine sampling technique in urinary tract infection may impact diagnostic accuracy and thus lead to possible over- or undertreatment. Currently no evidencebased consensus exists regarding correct sampling technique of urine from women with symptoms of urinary tract infection in primary care. The aim of this study was to determine the accuracy of urine culture from different sampling-techniques in symptomatic non-pregnant women in primary care. Methods A systematic review ...

  1. Development of detection techniques and diagnostics for airborne carbon nanoparticles.

    Energy Technology Data Exchange (ETDEWEB)

    Michelsen, Hope A.; Witze, Peter O.; Settersten, Thomas B.

    2003-11-01

    We have recorded time-resolved LII signals from a laminar ethylene diffusion flame over a wide range of laser fluences at 532 nm. We have performed these experiments using an injection-seeded NdYAG laser with a pulse duration of 7 ns. The beam was spatially filtered and imaged into the flame to provide a homogeneous spatial profile. These data were used to aid in the development of a model, which will be used to test the validity of the LII technique under varying environmental conditions. The new model describes the heating of soot particles during the laser pulse and the subsequent cooling of the particles by radiative emission, sublimation, and conduction. The model additionally includes particle heating by oxidation, accounts for the likelihood of particle annealing, and incorporates a mechanism for nonthermal photodesorption, which is required for good agreement with our experimental results. In order to investigate the fast photodesorption mechanism in more detail, we have recorded LII temporal profiles using a regeneratively amplified Nd:YAG laser with a pulse duration of 70 ps to heat the particles and a streak camera with a temporal resolution of {approx}65 ps to collect the signal. Preliminary results confirm earlier indications of a fast mechanism leading to signal decay rates of much less than a nanosecond. Parameters to which the model is sensitive include the initial soot temperature, the temperature of the ambient gas, and the partial pressure of oxygen. In order to narrow the model uncertainties, we have developed a source of soot that allows us to determine and control these parameters. Soot produced by a burner is extracted, diluted, and cooled in a flow tube, which is equipped with a Scanning Mobility Particle Sizer (SMPS) for characterization of the aggregates.

  2. Analysis of Arbitrary Reflector Antennas Applying the Geometrical Theory of Diffraction Together with the Master Points Technique

    Directory of Open Access Journals (Sweden)

    María Jesús Algar

    2013-01-01

    Full Text Available An efficient approach for the analysis of surface conformed reflector antennas fed arbitrarily is presented. The near field in a large number of sampling points in the aperture of the reflector is obtained applying the Geometrical Theory of Diffraction (GTD. A new technique named Master Points has been developed to reduce the complexity of the ray-tracing computations. The combination of both GTD and Master Points reduces the time requirements of this kind of analysis. To validate the new approach, several reflectors and the effects on the radiation pattern caused by shifting the feed and introducing different obstacles have been considered concerning both simple and complex geometries. The results of these analyses have been compared with the Method of Moments (MoM results.

  3. Textbook of focusing techniques in diagnostic radiography. 5. new rev. ed.

    International Nuclear Information System (INIS)

    This 5th edition of the standard work on focusing techniques in diagnostic radiography is a guide for X-ray medical technicians and radiologists wishing to optimize their skills and produce images of high technical standard and diagnostic value. The major part of the textbook deals with the focusing and imaging techniques for evaluation of the skeleton and inner body organs. The new edition includes the current legal provisions for radiological protection and the latest quality assurance legislation. It is an indispensable source of reference for clinical departments, radiographic practice, and training institutions. (orig./CB)

  4. Secondary Surveillance Radar Antenna

    OpenAIRE

    Schejbal, Vladimír; Bezoušek, Pavel; Pidanič, Jan; Chyba, Milan

    2013-01-01

    This paper deals with a secondary surveillance radar (SSR) array antenna, which is intended for a system combining the secondary surveillance radar antenna and the primary surveillance radar antenna. It describes the patch array elements and the synthesis for the secondary surveillance radar array, considering both elevation and azimuth patterns for sum, difference, and sidelobe-suppression beams, and suspended stripline couplers. The utilization of multilayer techniques allows the connection...

  5. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes. Additional information

    International Nuclear Information System (INIS)

    The reports from Argentina, Canada, India, Korea and Romania are presented concerning the projects carried out under the Coordinated Research Program (CRP) I3.30.10 of the International Agency for Atomic Energy - Vienna related to 'Intercomparison of Techniques for Pressure Tube Inspection and Diagnostics'

  6. Laser-direct-write technique for rapid prototyping of multiplexed paper-based diagnostic sensors

    OpenAIRE

    He, Peijun; Katis, Ioannis; Eason, Robert; Sones, Collin

    2015-01-01

    We report the successful demonstration of a laser-based direct-write technique for patterning of various porous materials to fabricate more diversified and multifunctional paper-based microfluidic devices that find applications in affordable point-of-care medical diagnostics

  7. Comparison of three rapid diagnostic techniques for detection of respiratory syncytial virus from nasal wash specimens.

    OpenAIRE

    Chonmaitree, T; Bessette-Henderson, B J; Hepler, R E; Lucia, H L

    1987-01-01

    We report results of three rapid tests for respiratory syncytial virus antigen detection. An immunofluorescence assay using commercial antibody and two commercial enzyme immunoassays (Ortho Diagnostics, Inc., Raritan, N.J., and Abbott Laboratories, North Chicago, Ill.) were applied to 199 nasal wash specimens. The Abbott enzyme immunoassay was the most sensitive technique, with a sensitivity of 93.8%. The specificities of the three techniques were comparable and greater than 95%. The availabi...

  8. Frequency Response Calculations of Input Characteristics of Cavity-Backed Aperture Antennas Using AWE with Hybrid FEM/MoM Technique

    Science.gov (United States)

    Reddy, C. J.; Deshpande, M. D.

    1997-01-01

    Application of Asymptotic Waveform Evaluation (AWE) is presented in conjunction with a hybrid Finite Element Method (FEM)/Method of Moments (MoM) technique to calculate the input characteristics of cavity-backed aperture antennas over a frequency range. The hybrid FEM/MoM technique is used to form an integro-partial-differential equation to compute the electric field distribution of the cavity-backed aperture antenna. The electric field, thus obtained, is expanded in a Taylor series around the frequency of interest. The coefficients of 'Taylor series (called 'moments') are obtained using the frequency derivatives of the integro-partial-differential Equation formed by the hybrid FEM/MoM technique. Using the moments, the electric field in the cavity is obtained over a frequency range. Using the electric field at different frequencies, the input characteristics of the antenna are obtained over a wide frequency band. Numerical results for an open coaxial line, probe fed cavity, and cavity-backed microstrip patch antennas are presented. Good agreement between AWE and the exact solution over the frequency range is observed.

  9. Application of Model Based Parameter Estimation for Fast Frequency Response Calculations of Input Characteristics of Cavity-Backed Aperture Antennas Using Hybrid FEM/MoM Technique

    Science.gov (United States)

    Reddy C. J.

    1998-01-01

    Model Based Parameter Estimation (MBPE) is presented in conjunction with the hybrid Finite Element Method (FEM)/Method of Moments (MoM) technique for fast computation of the input characteristics of cavity-backed aperture antennas over a frequency range. The hybrid FENI/MoM technique is used to form an integro-partial- differential equation to compute the electric field distribution of a cavity-backed aperture antenna. In MBPE, the electric field is expanded in a rational function of two polynomials. The coefficients of the rational function are obtained using the frequency derivatives of the integro-partial-differential equation formed by the hybrid FEM/ MoM technique. Using the rational function approximation, the electric field is obtained over a frequency range. Using the electric field at different frequencies, the input characteristics of the antenna are obtained over a wide frequency range. Numerical results for an open coaxial line, probe-fed coaxial cavity and cavity-backed microstrip patch antennas are presented. Good agreement between MBPE and the solutions over individual frequencies is observed.

  10. The Service Laboratory - A GTZ-BgVV project: Health protection through adapted veterinary diagnostic techniques

    International Nuclear Information System (INIS)

    The customary diagnostic methods of today have been developed in industrialized countries. High costs for personnel resulted in a trend towards automation and prefabricated test kits. Consequently, these techniques are not sufficiently adapted to local conditions in developing countries, where, as a rule, skilled and ancillary staff is available whereas foreign currency reserves for purchasing laboratory equipment and material from abroad are rather limited. Furthermore, the training of personnel from developing countries has usually been oriented towards thenon-transferable standards and methods of industrialized countries. This leads to a long term dependence of the diagnostic services on external funding. A diagnostic technology adapted to the specific local conditions of developing countries is needed to overcome this situation. The project activities concentrate on serological diagnostic work. Here, basic knowledge of the common diagnostic techniques and their set-up for specific diseases, methods for the production of related reagents (antigens, antibodies, conjugates, complement, etc.) and cleaning procedures for the reuse of 'one way' plastic material is spread by training programmes, specific publications and information leaflets. For two of the more complex test procedures, the most frequently quoted prescribed test for international trade, CFT, and the increasingly important ELISA (OIE, Manual of Standards for Diagnostic Techniques, Paris, 1992), we have calculated the cost reduction potential of adaptation through self-production of reagents and reuse of plastic materials. Material costs per microtitre test plate for the diagnosis of brucellosis can be reduced from US $3.79 to 0.82 for CFT and from US $3.88 to 1.13 for ELISA. In comparison, commercial ELISA kits cost about US $80 to 90 per plate (e.g. Bommeli, IDEXX, Boehringer)

  11. QUANTITATIVE BUFFY COAT (QBC TEST AND OTHER DIAGNOSTIC TECHNIQUES FOR DIAGNOSIG MALARIA: REVIEW OF LITRATURE

    Directory of Open Access Journals (Sweden)

    Kuladeepa Ananda Vaidya

    2012-06-01

    Full Text Available The technical capability to perform a correct and timely diagnosis of malaria infection in an ill patient is of critical importance since symptoms of complicated malaria may suddenly develop, leading to death of the patient. Even though peripheral blood smear examination is considered as the gold standard technique, tests like Quantitative Buffy Coat (QBC test and Rapid diagnostic tests (RDTs are widely used and more sensitive in detecting malaria parasite. Here we are briefly highlighting the importance of QBC and other useful diagnostic methods for diagnosing malaria. [National J of Med Res 2012; 2(3.000: 386-388

  12. Laser direct write techniques for the fabrication of paper-based diagnostic devices

    OpenAIRE

    Katis, Ioannis

    2015-01-01

    We report on the use of laser direct-write techniques for the fabrication of point-of-care paper-based diagnostic sensors. These include laser-based deposition, laser ablation and laser-induced photo-polymerisation. Firstly, Laser Induced Forward Transfer (LIFT) was employed to deposit biomolecules from a donor film onto paper receivers. Paper was chosen as the ideal receiver because of its inherent properties which make it an efficient and suitable platform for point-of-care diagnostic s...

  13. Improved Signal Processing Technique Leads to More Robust Self Diagnostic Accelerometer System

    Science.gov (United States)

    Tokars, Roger; Lekki, John; Jaros, Dave; Riggs, Terrence; Evans, Kenneth P.

    2010-01-01

    The self diagnostic accelerometer (SDA) is a sensor system designed to actively monitor the health of an accelerometer. In this case an accelerometer is considered healthy if it can be determined that it is operating correctly and its measurements may be relied upon. The SDA system accomplishes this by actively monitoring the accelerometer for a variety of failure conditions including accelerometer structural damage, an electrical open circuit, and most importantly accelerometer detachment. In recent testing of the SDA system in emulated engine operating conditions it has been found that a more robust signal processing technique was necessary. An improved accelerometer diagnostic technique and test results of the SDA system utilizing this technique are presented here. Furthermore, the real time, autonomous capability of the SDA system to concurrently compensate for effects from real operating conditions such as temperature changes and mechanical noise, while monitoring the condition of the accelerometer health and attachment, will be demonstrated.

  14. MR cholangiopancreatography: technique, potential indications, and diagnostic features of benign, postoperative, and malignant conditions

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.D. [Department of Radiology, Division of Diagnostic and Interventional Radiology, University Hospital of Geneva, CH-1211 Geneva (Switzerland); Grossholz, M. [Department of Radiology, Division of Diagnostic and Interventional Radiology, University Hospital of Geneva, CH-1211 Geneva (Switzerland); Mentha, G. [Department of Surgery, University Hospital of Geneva, CH-1211 Geneva (Switzerland); Peyer, R. de [Division of Gastroenterology, University Hospital of Geneva, CH-1211 Geneva (Switzerland); Terrier, F. [Department of Radiology, Division of Diagnostic and Interventional Radiology, University Hospital of Geneva, CH-1211 Geneva (Switzerland)

    1997-08-01

    The objective of this article is to review technical aspects, discuss potential clinical indications for MR cholangiopancreatography (MRCP) and demonstrate the spectrum of diagnostic findings in benign, postoperative, and malignant conditions. We describe our current imaging protocol in comparison with other available techniques. Using a non-breath-hold, heavily T2-weighted fast-spin-echo (FSE) sequence with or without respiratory gating we obtained coronal and axial source images and maximum intensity projections (MIPs) in 102 patients with suspected abnormalities of the biliary or pancreatic ducts. Based on this series we demonstrate the diagnostic appearance of a variety of benign, postoperative, and malignant conditions of the biliary and pancreatic ducts and discuss potential clinical indications for MRCP. The non-breath-hold FSE technique enables a consistent image quality even in patients who cannot cooperate well. Respiratory gating increased the rate of diagnostic examinations from 79 to 95 %. Acquisition of coronal and axial source images enables detection of bile duct stones as small as 2 mm, although calculi that are impacted and not surrounded by hyperintense bile may sometimes be difficult to detect. The MIP reconstructions help to determine the level of obstruction in malignant jaundice, delineate anatomical variants and malformations, and to diagnose inflammatory conditions, e. g., sclerosing cholangitis, the Mirizzi syndrome and inflammatory changes in the main pancreatic duct. The MRCP technique also correctly demonstrates the morphology of bilio-enteric or bilio-biliary anastomoses. Because MRCP provides sufficient diagnostic information in a wide range of benign and malignant biliary and pancreatic disorders, it could obviate diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in many clinical settings. The ERCP technique may be increasingly reserved for patients in whom nonsurgical interventional procedures are anticipated. (orig

  15. High-Energy X-ray Absorption Diagnostics as an Experimental Combustion Technique

    Science.gov (United States)

    Dunnmon, Jared; Sobhani, Sadaf; Hinshaw, Waldo; Fahrig, Rebecca; Ihme, Matthias

    2015-11-01

    X-ray diagnostics such as X-ray Computed Tomography (XCT) have recently been utilized for measurement of scalar concentration fields in gas-phase flow phenomena. In this study, we apply high-energy X-ray absorption techniques to visualize a laboratory-scale flame via fluoroscopic measurements by using krypton as a radiodense tracer media. Advantages of X-ray absorption diagnostics in a combustion context, including application to optically inaccessible environments and lack of ambient photon interference, are demonstrated. Analysis methods and metrics for extracting physical insights from these data are presented. The accuracy of the diagnostic is assessed via comparison to known results from canonical flame configurations, and the potential for further applications is discussed. Support from the NDSEG fellowship, Bosch, and NASA are gratefully acknolwedged.

  16. Co-Design Method and Wafer-Level Packaging Technique of Thin-Film Flexible Antenna and Silicon CMOS Rectifier Chips for Wireless-Powered Neural Interface Systems.

    Science.gov (United States)

    Okabe, Kenji; Jeewan, Horagodage Prabhath; Yamagiwa, Shota; Kawano, Takeshi; Ishida, Makoto; Akita, Ippei

    2015-01-01

    In this paper, a co-design method and a wafer-level packaging technique of a flexible antenna and a CMOS rectifier chip for use in a small-sized implantable system on the brain surface are proposed. The proposed co-design method optimizes the system architecture, and can help avoid the use of external matching components, resulting in the realization of a small-size system. In addition, the technique employed to assemble a silicon large-scale integration (LSI) chip on the very thin parylene film (5 μm) enables the integration of the rectifier circuits and the flexible antenna (rectenna). In the demonstration of wireless power transmission (WPT), the fabricated flexible rectenna achieved a maximum efficiency of 0.497% with a distance of 3 cm between antennas. In addition, WPT with radio waves allows a misalignment of 185% against antenna size, implying that the misalignment has a less effect on the WPT characteristics compared with electromagnetic induction. PMID:26694407

  17. Co-Design Method and Wafer-Level Packaging Technique of Thin-Film Flexible Antenna and Silicon CMOS Rectifier Chips for Wireless-Powered Neural Interface Systems

    Directory of Open Access Journals (Sweden)

    Kenji Okabe

    2015-12-01

    Full Text Available In this paper, a co-design method and a wafer-level packaging technique of a flexible antenna and a CMOS rectifier chip for use in a small-sized implantable system on the brain surface are proposed. The proposed co-design method optimizes the system architecture, and can help avoid the use of external matching components, resulting in the realization of a small-size system. In addition, the technique employed to assemble a silicon large-scale integration (LSI chip on the very thin parylene film (5 μm enables the integration of the rectifier circuits and the flexible antenna (rectenna. In the demonstration of wireless power transmission (WPT, the fabricated flexible rectenna achieved a maximum efficiency of 0.497% with a distance of 3 cm between antennas. In addition, WPT with radio waves allows a misalignment of 185% against antenna size, implying that the misalignment has a less effect on the WPT characteristics compared with electromagnetic induction.

  18. Improvements in diagnostic techniques in medicine with lower exposure of the patient and staff

    International Nuclear Information System (INIS)

    It is a well known fact that radiation doses from the use of ionizing radiations and radionuclides in medical diagnosis and treatment are the largest contribution to the collective dose from all man-made sources of radiation, occupying about 15% of the total collective dose, and rapidly increase over the world, due to their relatively high frequency. From this, it is obvious that medical use of ionizing radiation should be of major concern for radiation protection. There has been significant development of imaging technology for diagnostic radiology and other medical imaging technology over the past 100 years, and the doses of radiation to the patient and staff in medical uses have steadily decreased. Despite of developments in diagnostic techniques, the problem of trading off image quality against health risk due to radiation exposure still persists. This paper will briefly summarize the historical overview of developments of techniques and equipments in diagnostic radiology, and introduce the goal of a radiation safety philosophy and ALARA in diagnostic radiology. (author)

  19. A technique to improve diagnostic information from fine-needle aspirations: immunohistochemistry on cytoscrape

    DEFF Research Database (Denmark)

    Skov, Birgit Guldhammer; Kiss, Katalin; Ramsted, Julie;

    2009-01-01

    made, and the sections were stained for thyroid transcription factor-1 (TTF-1) and mucin. The utility of the CS technique was evaluated by assessing the sensitivity and specificity of the method and by quantifying the extra diagnostic information obtained by the method relative to smears alone. RESULTS......: Malignant tumor cells in the CS material were identified in 43 aspirates (91%). Both the sensitivity and the specificity for TTF-1 were 100%. The sensitivity for mucin was 60%, and the specificity for mucin was 100%. The diagnoses made on smears were improved by CS in 31 patients (72%), in that more precise...... separation of subgroups of NSCLC was possible or information on primary tumors was obtained. CONCLUSIONS: The CS technique improved the diagnostic information from FNA in a clinically relevant way. The method is simple, quick, and inexpensive....

  20. Plasma diagnostic techniques in thermal-barrier tandem-mirror fusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Silver, E.H.; Clauser, J.F.; Carter, M.R.; Failor, B.H.; Foote, J.H.; Hornady, R.S.; James, R.A.; Lasnier, C.J.; Perkins, D.E.

    1986-08-29

    We review two classes of plasma diagnostic techniques used in thermal-barrier tandem-mirror fusion experiments. The emphasis of the first class is to study mirror-trapped electrons at the thermal-barrier location. The focus of the second class is to measure the spatial and temporal behavior of the plasma space potential at various axial locations. The design and operation of the instruments in these two categories are discussed and data that are representative of their performance is presented.

  1. QUANTITATIVE BUFFY COAT (QBC) TEST AND OTHER DIAGNOSTIC TECHNIQUES FOR DIAGNOSIG MALARIA: REVIEW OF LITRATURE

    OpenAIRE

    Kuladeepa Ananda Vaidya; Sukesh K

    2012-01-01

    The technical capability to perform a correct and timely diagnosis of malaria infection in an ill patient is of critical importance since symptoms of complicated malaria may suddenly develop, leading to death of the patient. Even though peripheral blood smear examination is considered as the gold standard technique, tests like Quantitative Buffy Coat (QBC) test and Rapid diagnostic tests (RDTs) are widely used and more sensitive in detecting malaria parasite. Here we are briefly highlighting ...

  2. MR cholangiopancreatography: prospective comparison of a breath-hold 2D projection technique with diagnostic ERCP

    Energy Technology Data Exchange (ETDEWEB)

    Lomas, D.J.; Bearcroft, P.W.P.; Gimson, A.E. [University Department of Radiology, Addenbrooke Hospital, Cambridge (United Kingdom)

    1999-09-01

    The aim of this study was to compare prospectively a breath-hold projection magnetic resonance cholangiopancreatography (MRCP) technique with diagnostic endoscopic retrograde cholangiopancreatography (ERCP). Seventy-six patients with suspected strictures or choledocholithiasis were referred for MRCP and subsequent ERCP examination, which were performed within 4 h of each other. The MRCP technique was performed using fat-suppressed rapid acquisition with relaxation enhancement (RARE) projection images obtained in standardised planes with additional targeted projections as required by the supervising radiologist. Two radiologists (in consensus) assessed the MRCP results prospectively and independently for the presence of bile duct calculi, strictures, non-specific biliary dilatation and pancreatic duct dilatation, and recorded a single primary diagnosis. The ERCP was assessed prospectively and independently by a single endoscopist and used as a gold standard for comparison with MRCP. Diagnostic agreement was assessed by the Kappa statistic. The MRCP technique failed in two patients and ERCP in five. In the remaining 69 referrals ERCP demonstrated normal findings in 23 cases, strictures in 19 cases, choledocholithiasis in 9 cases, non-specific biliary dilatation in 14 cases and chronic pancreatitis in 4 cases. The MRCP technique correctly demonstrated 22 of 23 normal cases, 19 strictures with one false positive (sensitivity 100 %, specificity 98 %), all 9 cases of choledocholithiasis with two false positives (sensitivity 100 %, specificity 97 %), 12 of 14 cases of non-specific biliary dilatation and only 1 of 4 cases of chronic pancreatitis. There was overall good agreement for diagnosis based on a kappa value of 0.88. Breath-hold projection MRCP can provide non-invasively comparable diagnostic information to diagnostic ERCP for suspected choledocholithiasis and biliary strictures and may allow more selective use of therapeutic ERCP. (orig.) With 6 figs., 1 tab., 20

  3. Probability-Based Diagnostic Imaging Technique Using Error Functions for Active Structural Health Monitoring

    OpenAIRE

    Rahim Gorgin; Zhanjun Wu

    2014-01-01

    This study presents a novel probability-based diagnostic imaging (PDI) technique using error functions for active structural health monitoring (SHM). To achieve this, first the changes between baseline and current signals of each sensing path are measured, and by taking the root mean square of such changes, the energy of the scattered signal at different times can be calculated. Then, for different pairs of signal acquisition paths, an error function based on the energy of the...

  4. Diagnostic Values of Laser Fluorescence Device with Other Techniques in Occlusal Caries Detection

    Directory of Open Access Journals (Sweden)

    A. Chehresaz

    2009-06-01

    Full Text Available Objective: The aim of the present study was to compare the performance of laser fluorescence (LF method with other conventional diagnostic techniques in detection of smallocclusal caries in permanent teeth.Materials and Methods: Prior to this in vitro diagnostic study, a pilot study assessed intra-examiner reliability and reproducibility. The occlusal surfaces of 90 extracted human premolars were examined with four diagnostic methods: probing, visual inspection, bitewing(BW radiographs, and LF. The teeth were then sectioned for the purpose of histological examination. The data were analyzed using SPSS 15 software, and sensitivity,specificity and other diagnostic criteria of the techniques were calculated.Results: The intra-examiner reproducibility for probing and also radiographic techniques was 100%. The corresponded figure for LF (88% was more than visual inspection (82%.The highest level of validity of the examiner turned out to be in probing technique(76.9%. Sensitivity of visual inspection, probing, and LF methods was 54.5% and that of BW radiography was 27.5%. Specificity and efficiency of LF method were 84.8% and 81.1%, respectively. Probing and visual inspection showed the highest specificity (97.5% and 94.9, respectively and efficiency (92.2% and 90%, respectively among the methods.Conclusion: Specificity and efficiency of LF method were lower compared to those of other methods. Among all the investigated methods, the most efficient methods in the diagnosis of small occlusal caries in permanent teeth were probing and visual inspection,respectively.

  5. Plasma diagnostic techniques in thermal-barrier tandem-mirror fusion experiments

    International Nuclear Information System (INIS)

    We review two classes of plasma diagnostic techniques used in thermal-barrier tandem-mirror fusion experiments. The emphasis of the first class is to study mirror-trapped electrons at the thermal-barrier location. The focus of the second class is to measure the spatial and temporal behavior of the plasma space potential at various axial locations. The design and operation of the instruments in these two categories are discussed and data that are representative of their performance is presented

  6. Rare-cell enrichment by a rapid, label-free, ultrasonic isopycnic technique for medical diagnostics

    OpenAIRE

    Bourquin, Yannyk; Syed, Abeer; Reboud, Julien; Ranford-Cartwright, Lisa C.; Barrett, Michael P.; Cooper, Jonathan M.

    2014-01-01

    One significant challenge in medical diagnostics lies in the development of label-free methods to separate different cells within complex biological samples. Here we demonstrate a generic, low-power ultrasonic separation technique, able to enrich different cell types based upon their physical properties. For malaria, we differentiate between infected and non-infected red blood cells in a fingerprick-sized drop of blood. We are able to achieve an enrichment of circulating cells infected by the...

  7. Rare-Cell Enrichment by a Rapid, Label-Free, Ultrasonic Isopycnic Technique for Medical Diagnostics**

    OpenAIRE

    Bourquin, Yannyk; Syed, Abeer; Reboud, Julien; Ranford-Cartwright, Lisa C.; Barrett, Michael P.; Cooper, Jonathan M.

    2014-01-01

    One significant challenge in medical diagnostics lies in the development of label-free methods to separate different cells within complex biological samples. Here we demonstrate a generic, low-power ultrasonic separation technique, able to enrich different cell types based upon their physical properties. For malaria, we differentiate between infected and non-infected red blood cells in a fingerprick-sized drop of blood. We are able to achieve an enrichment of circulating cells infected by the...

  8. Smart antennas

    CERN Document Server

    Godara, Lal Chand

    2004-01-01

    INTRODUCTION Antenna GainPhased Array AntennaPower Pattern Beam Steering Degree of Freedom Optimal AntennaAdaptive AntennaSmart AntennaSummary NARROWBAND PROCESSINGSignal Model Conventional BeamformerNull Steering BeamformerOptimal BeamformerOptimization Using Reference SignalBeam Space Processing Effect of ErrorsNotation and AbbreviationsReferencesADAPTIVE PROCESSINGSample Matrix Inversion AlgorithmUnconstrained Least Mean Squares AlgorithmNormalized Least Mean Squares AlgorithmConstrained

  9. Cavity Backed Slot Antenna

    Directory of Open Access Journals (Sweden)

    Sarang Masani, Ila Parmar, Hitendra Jadeja

    2013-05-01

    Full Text Available Among the current driving forces in wireless communications, there is a need for compact, efficient, inexpensive and reproducible antennas. In some instances, particularly long-distance applications, radiators with directive, high-gain characteristics are necessary. This paper proposes a cavity-backed slot antenna to that end. This antenna will enhance the gain, directivity and can also be easily flush mounted to the flying object. The shape and size of the slot can be effectively utilized to get the desired result. The proposed antenna is feed by waveguide which facilitate it to be applicable at high power operation where coaxial cable fails due to skin effect. Present antenna is verified using Numerical Technique called Finite Element Method FEM. The conception of this antenna is realized by the software HFSS “Ansoft-High Frequency Structure Simulator”. By properly selecting shapes, dimensions of the slots and number of slot affects the parameters like return loss, gain along Θ, Ø directions, Cartesian plot and radiation pattern .The Backing of cavity to the slot antenna provide the basics of the gain enhancement and the slot loading effect and the cavity volume plays an important role in achieving the desired return loss at the specific frequency.The simulated antenna shows the 7.0944 db of gain and return loss of -28.60. The proposed antenna works at 6 GHz.

  10. Optical diagnostics of vascular reactions triggered by weak allergens using laser speckle-contrast imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Yu L; Kalchenko, V V [Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, 76100 (Israel); Astaf' eva, N G [V.I.Razumovsky Saratov State Medical University, Saratov (Russian Federation); Meglinski, I V [N.G. Chernyshevsky Saratov State University, Saratov (Russian Federation)

    2014-08-31

    The capability of using the laser speckle contrast imaging technique with a long exposure time for visualisation of primary acute skin vascular reactions caused by a topical application of a weak contact allergen is considered. The method is shown to provide efficient and accurate detection of irritant-induced primary acute vascular reactions of skin. The presented technique possesses a high potential in everyday diagnostic practice, preclinical studies, as well as in the prognosis of skin reactions to the interaction with potentially allergenic materials. (laser biophotonics)

  11. An inexpensive S-band angle pointing technique for steering a narrow beam Ku-band antenna

    Science.gov (United States)

    Line, Larry; Hager, Fred; Hanson, Duke; Kral, Kevin; Moss, Robert

    1987-01-01

    A recently tested antenna pointing control system for gimbaled antennas has been developed. A modified TDRSS user transponder produces pointing error signals from the S-band forward link which in turn drive the Steering Control Electronics (SCE) to precision steer a S-/Ku-band Data and S-band Tracking (KDST) planar array. A successful test of the pointing and data handling capabilities is described and plans for further tests, incorporating additional refinements, are presented.

  12. Applications of swept-frequency acoustic interferometry technique in chemical diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, D.N.; Springer, K.; Lizon, D.; Hasse, R.

    1996-09-01

    Swept-Frequency Acoustic Interferometry (SFAI) is a noninvasive fluid characterization technique currently being developed for chemical weapons treaty verification. The SFAI technique determines sound speed and sound attenuation in a fluid over a wide frequency range completely noninvasively from outside a container (e.g., pipe, tank, reactor vessel, etc.,). These acoustic parameters, along with their frequency-dependence, can be used to identify various chemicals. This technique can be adapted for a range of chemical diagnostic applications, particularly, in process control where monitoring of acoustic properties of chemicals may provide appropriate feedback information. Both experimental data and theoretical modeling are presented. Examples of several novel applications of the SFAI technique are discussed.

  13. Optimized design of shields for diagnostic X rays with NCRP 147 technique

    International Nuclear Information System (INIS)

    A comparison among the design techniques of shielding for X-ray diagnostic rooms with the NCRP 49 (1976) report technique, AAPM 39 (1993) Y the one of the NCRP 147 (2005) technique. The designs correspond to a room of conventional X-rays, one of fluoroscopy, one of tomography Y one of mammography. In all the cases it demonstrates that the NCRP 49 technique overestimate the shieldings. The causes of the overestimation of the NCRP 49 can be attributed to: a) high values of the work charge that don't consider the spectral fluence of the photons that are present in each room, b) to the differences in the values of the kerma in air without attenuation for the dispersed primary radiation Y of leakage among both reports. (Author)

  14. EFDA Task TW6-TPDS-DIADEV deliverable 2: ITER Fast Ion Collective Scattering Development of diagnostic components and techniques

    DEFF Research Database (Denmark)

    Michelsen, S.; Bindslev, Henrik; Korsholm, Søren Bang; Leipold, Frank; Meo, Fernando; Michelsen, Poul; Nielsen, Anders Henry; Tsakadze, Erekle

    In 2003 the Risø CTS group finished a feasibility study and a conceptual design of an ITER fast ion collective Thomson scattering system. The purpose of the CTS diagnostic is to measure the distribution function of fast ions in the plasma with particular interest in fusion alphas. The feasibility......) Optimisation of the design, considering the scattering geometries, variations in plasma profiles, magnetic equilibria etc. 2) Development of numerical codes for determination of the geometry of the antenna system on the high field side, including shapes and positions of mirrors and receiver horns. 3) A model...

  15. Consideration on the diagnostic ability of various imaging techniques in relation to renal tumor

    International Nuclear Information System (INIS)

    Radiological diagnosis of renal tumors is being improved with the increased imaging accuracy which has resulted from advancement in the various equipment used and improvement in techniques. However, at the clinical level, diagnostic procedures based on the characteristics of the delineated images are not yet established and the diverse diagnostic procedures are being conducted currently in a stereotyped manner. In this study, the images of 61 cases diagnosed as renal tumor were analysed retrospectively with the purpose of establishing the imaging accuracy, capacity for diagnosis based on image characteristics and a subseguent proper diagnostic procedure. It was found that CT and Angio gave similar diagnostic accuracy. It was further revealed that US images enabled to differentiate renal tumors from the more commonly experienced renal cystic disease. For determination of tunica involucrum infiltration, which is essential to diagnose Stage I and II renal tumors, CT was proved to be superior to Angio. CT and US were also to be so in the determination of metastasis to para-aortic lymph nodes which is a Stage III criterion. In recent years, CT and US imaging accuracies have increased, hence the improvement in the capacity to diagnose non-observable renal tumors is highly expected. (author)

  16. Antenna Miniaturization in Complex Electromagnetic Environments

    DEFF Research Database (Denmark)

    Zhang, Jiaying

    - less communication system into the heading-aids, and these are the antenna miniaturization, the measurement techniques for electrically small antennas and the influence of complex environments on the characteristics of electrically small antennas, respectively. Antenna MiniaturizationIn this...... dissertation, we present several novel designs of electrically small loop antennas for the hearing-aid application. First antenna design is a two-dimensional (2-D) planar differential-fed electrically small loop. The working mechanism of this antenna is based on the capacitive loading and the induc- tive...... coupling between two small loops. An analytical model, simulations, fabrications and measurements are presented for this antenna. Second antenna design is a planar two-turn electrically small loop antenna. The work- ing mechanism of this antenna is based on the capacitive loading, and both the capacitive...

  17. PREFACE: IX International Conference on Modern Techniques of Plasma Diagnostics and their Application

    Science.gov (United States)

    Savjolov, A. S.; Dodulad, E. I.

    2016-01-01

    The IX Conference on ''Modern Techniques of Plasma Diagnosis and their Application'' was held on 5 - 7 November, 2014 at National Research Nuclear University MEPhI (NRNU MEPhI). The goal of the conference was an exchange of information on both high-temperature and low-temperature plasma diagnostics as well as deliberation and analysis of various diagnostic techniques and their applicability in science, industry, ecology, medicine and other fields. The Conference also provided young scientists from scientific centres and universities engaged in plasma diagnostics with an opportunity to attend the lectures given by the leading specialists in this field as well as present their own results and findings. The first workshop titled ''Modern problems of plasma diagnostics and their application for control of chemicals and the environment'' took place at Moscow Engineering and Physics Institute (MEPhI) in June 1998 with the support of the Section on Diagnostics of the Council of Russian Academic of Science on Plasma Physics and since then these forums have been held at MEPhI every two years. In 2008 the workshop was assigned a conference status. More than 150 specialists on plasma diagnostics and students took part in the last conference. They represented leading Russian scientific centres (such as Troitsk Institute of Innovative and Thermonuclear Research, National Research Centre ''Kurchatov Institute'', Russian Federal Nuclear Centre - All-Russian Scientific Research Institute of Experimental Physics and others) and universities from Belarus, Ukraine, Germany, USA, Belgium and Sweden. About 30 reports were made by young researchers, students and post-graduate students. All presentations during the conference were broadcasted online over the internet with viewers in Moscow, Prague, St. Petersburgh and other cities. The Conference was held within the framework of the Centre of Plasma, Laser Research and Technology supported by MEPhI Academic Excellence Project (Russian

  18. Evidence-based medical research on diagnostic criteria and screening technique of vascular mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Xia-wei LIU

    2015-07-01

    Full Text Available Background Vascular mild cognitive impairment (VaMCI is the prodromal syndrome of vascular dementia (VaD and key target for drug treatment. There is controversy over the diagnostic criteria and screening tools of VaMCI, which affects its clinical diagnosis. This paper aims to explore the clinical features, diagnostic criteria and screening technique of VaMCI.  Methods Taking "vascular mild cognitive impairment OR vascular cognitive impairment no dementia" as retrieval terms, search in PubMed database from January 1997 to March 2015 and screen relevant literatures concerning VaMCI. According to Guidance for the Preparation of Neurological Management Guidelines revised by European Federation of Neurological Societies (EFNS in 2004, evidence grading was performed on literatures. Results A total of 32 literatures in English were selected according to inclusion and exclusion criteria, including 3 guidelines and consensus and 29 clinical studies. Seven literatures (2 on Level Ⅰ, 5 on Level Ⅱ studied on neuropsychological features in VaMCI patients and found reduced processing speed and executive function impairment were main features. Two literatures reported the diagnostic criteria of VaMCI, including VaMCI criteria published by American Heart Association (AHA/American Stroke Association (ASA in 2011 and "Diagnostic Criteria for Vascular Cognitive Disorders" published by International Society for Vascular Behavioral and Cognitive Disorders (VASCOG in 2014. Fifteen literatures (4 on LevelⅠ, 11 on Level Ⅱ described the diagnostic criteria of VaMCI used in clinical research, from which 6 operational diagnostic items were extracted. Fourteen literatures (4 on Level Ⅰ, 10 on Level Ⅱ described neuropsychological assessment tools for VaMCI screening, and found the 5-minute protocol recommended by National Institute of Neurological Disorders and Stroke-Canadian Stroke Network (NINDS-CSN was being good consistency with other neuropsychological

  19. Microstrip antenna theory and design

    Science.gov (United States)

    James, J. R.; Hall, P. S.; Wood, C.

    Microstrip is the name given to a type of open waveguiding structure which is now commonly used in present-day electronics, not only as a transmission line but for circuit components such as filters, couplers, and resonators. The idea of using microstrip to construct antennas is a much more recent development. The purpose of this monograph is to present the reader with an appreciation of useful antenna design approaches and the overall state-of-the art situation. Flat-plate antenna techniques and constraints on performance are considered along with microstrip design equations and data, the radiation mechanism of an open-circuit microstrip termination and the resulting design implications, the basic methods of calculation and design of patch antennas, and linear array techniques. Attention is also given to techniques and design limitations in two-dimensional arrays, circular polarization techniques, manufacturing and operational problems of microstrip antennas, recent advances in microstrip antenna analysis, and possible future developments.

  20. Certain investigations on the reduction of side lobe level of an uniform linear antenna array using biogeography based optimization technique with sinusoidal migration model and simplified-BBO

    Indian Academy of Sciences (India)

    T S Jeyali Laseetha; R Sukanesh

    2014-02-01

    In this paper, we propose biogeography based optimization technique, with linear and sinusoidal migration models and simplified biogeography based optimization (S-BBO), for uniformly spaced linear antenna array synthesis to maximize the reduction of side lobe level (SLL). This paper explores biogeography theory. It generalizes two migration models in BBO namely, linear migration model and sinusoidal migration model. The performance of SLL reduction in ULA is investigated. Our performance study shows that among the two, sinusoidal migration model is a promising candidate for optimization. In our work, simplified – BBO algorithmis also deployed. This determines an optimum set value for amplitude excitations of antenna array elements that generate a radiation pattern with maximum side lobe level reduction. Our detailed investigation also shows that sinusoidal migration model of BBO performs better compared to the other evolutionary algorithms discussed in this paper.

  1. EFDA Task TW6-TPDS-DIADEV deliverable 2: ITER fast ion collective scattering development of diagnostic components and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Michelsen, S.; Bindslev, H.; Korsholm, S.B.; Leipold, F.; Meo, F.; Michelsen, P.K.; Nielsen, A.H.; Tsakadze, E.

    2009-12-15

    In 2003 the Risoe CTS group finished a feasibility study and a conceptual design of an ITER fast ion collective Thomson scattering system. The purpose of the CTS diagnostic is to measure the distribution function of fast ions in the plasma with particular interest in fusion alphas. The feasibility study demonstrated that the only system, which can fully meet the ITER measurement requirements for confined fusion alphas, is a 60 GHz system. The study showed that by using two powerful microwave sources (gyrotrons) of this frequency both on the low field side, and two antenna systems, one on the low field side and one on the high field side, it is possible to resolve the distribution function of fast ions both for perpendicular andvparallel velocities with good spatial and temporal resolution. The present workvconcerned a continuation of this work, and the following tasks were performed. 1) Optimisation of the design, considering the scattering geometries, variations in plasma profiles, magnetic equilibria etc. 2) Development of numerical codes for determination of the geometry of the antenna system on the high field side, including shapes and positions of mirrors and receiver horns. 3) A model experiment was set up in order to test and support the theoretical and numerical results. From the design studies various R and D issues critical to the viability of the CTS diagnostic on ITER were identified; the most urgent ones are addressed in the presented R and D tasks. (author)

  2. EFDA Task TW6-TPDS-DIADEV deliverable 2: ITER fast ion collective scattering development of diagnostic components and techniques

    International Nuclear Information System (INIS)

    In 2003 the Risoe CTS group finished a feasibility study and a conceptual design of an ITER fast ion collective Thomson scattering system. The purpose of the CTS diagnostic is to measure the distribution function of fast ions in the plasma with particular interest in fusion alphas. The feasibility study demonstrated that the only system, which can fully meet the ITER measurement requirements for confined fusion alphas, is a 60 GHz system. The study showed that by using two powerful microwave sources (gyrotrons) of this frequency both on the low field side, and two antenna systems, one on the low field side and one on the high field side, it is possible to resolve the distribution function of fast ions both for perpendicular andvparallel velocities with good spatial and temporal resolution. The present workvconcerned a continuation of this work, and the following tasks were performed. 1) Optimisation of the design, considering the scattering geometries, variations in plasma profiles, magnetic equilibria etc. 2) Development of numerical codes for determination of the geometry of the antenna system on the high field side, including shapes and positions of mirrors and receiver horns. 3) A model experiment was set up in order to test and support the theoretical and numerical results. From the design studies various R and D issues critical to the viability of the CTS diagnostic on ITER were identified; the most urgent ones are addressed in the presented R and D tasks. (author)

  3. Iterative reconstruction technique with reduced volume CT dose index: diagnostic accuracy in pediatric acute appendicitis

    International Nuclear Information System (INIS)

    Iterative reconstruction technique has been proposed as a means of reducing patient radiation dose in pediatric CT. Yet, the effect of such reductions on diagnostic accuracy has not been thoroughly evaluated. This study compares accuracy of diagnosing pediatric acute appendicitis using contrast-enhanced abdominopelvic CT scans performed with traditional pediatric weight-based protocols and filtered back projection reconstruction vs. a filtered back projection/iterative reconstruction technique blend with reduced volume CT dose index (CTDIvol). Results of pediatric contrast-enhanced abdominopelvic CT scans done for pain and/or suspected appendicitis were reviewed in two groups: A, 192 scans performed with the hospital's established weight-based CT protocols and filtered back projection reconstruction; B, 194 scans performed with iterative reconstruction technique and reduced CTDIvol. Reduced CTDIvol was achieved primarily by reductions in effective tube current-time product (mAseff) and tube peak kilovoltage (kVp). CT interpretation was correlated with clinical follow-up and/or surgical pathology. CTDIvol, size-specific dose estimates (SSDE) and performance characteristics of the two CT techniques were then compared. Between groups A and B, mean CTDIvol was reduced by 45%, and mean SSDE was reduced by 46%. Sensitivity, specificity and diagnostic accuracy were 96%, 97% and 96% in group A vs. 100%, 99% and 99% in group B. Accuracy in diagnosing pediatric acute appendicitis was maintained in contrast-enhanced abdominopelvic CT scans that incorporated iterative reconstruction technique, despite reductions in mean CTDIvol and SSDE by nearly half as compared to the hospital's traditional weight-based protocols. (orig.)

  4. Iterative reconstruction technique with reduced volume CT dose index: diagnostic accuracy in pediatric acute appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    Didier, Ryne A. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Vajtai, Petra L. [Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States); Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Hopkins, Katharine L. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States)

    2014-07-05

    Iterative reconstruction technique has been proposed as a means of reducing patient radiation dose in pediatric CT. Yet, the effect of such reductions on diagnostic accuracy has not been thoroughly evaluated. This study compares accuracy of diagnosing pediatric acute appendicitis using contrast-enhanced abdominopelvic CT scans performed with traditional pediatric weight-based protocols and filtered back projection reconstruction vs. a filtered back projection/iterative reconstruction technique blend with reduced volume CT dose index (CTDI{sub vol}). Results of pediatric contrast-enhanced abdominopelvic CT scans done for pain and/or suspected appendicitis were reviewed in two groups: A, 192 scans performed with the hospital's established weight-based CT protocols and filtered back projection reconstruction; B, 194 scans performed with iterative reconstruction technique and reduced CTDI{sub vol}. Reduced CTDI{sub vol} was achieved primarily by reductions in effective tube current-time product (mAs{sub eff}) and tube peak kilovoltage (kVp). CT interpretation was correlated with clinical follow-up and/or surgical pathology. CTDI{sub vol}, size-specific dose estimates (SSDE) and performance characteristics of the two CT techniques were then compared. Between groups A and B, mean CTDI{sub vol} was reduced by 45%, and mean SSDE was reduced by 46%. Sensitivity, specificity and diagnostic accuracy were 96%, 97% and 96% in group A vs. 100%, 99% and 99% in group B. Accuracy in diagnosing pediatric acute appendicitis was maintained in contrast-enhanced abdominopelvic CT scans that incorporated iterative reconstruction technique, despite reductions in mean CTDI{sub vol} and SSDE by nearly half as compared to the hospital's traditional weight-based protocols. (orig.)

  5. Plasma antennas

    CERN Document Server

    Anderson, Theodore

    2011-01-01

    The plasma antenna is an emerging technology that partially or fully utilizes ionized gas as the conducting medium instead of metal to create an antenna. The key advantages of plasma antennas are that they are highly reconfigurable and can be turned on and off. The disadvantage is that the plasma antennas require energy to be ionized. This unique resource provides you with a solid understanding of the efficient design and prototype development of plasma antennas, helping you to meet the challenge of reducing the power required to ionize the gas at various plasma densities. You also find thorou

  6. Reconfigurable antenna pattern verification

    Science.gov (United States)

    Drexler, Jerome P. (Inventor); Becker, Robert C. (Inventor); Meyers, David W. (Inventor); Muldoon, Kelly P. (Inventor)

    2013-01-01

    A method of verifying programmable antenna configurations is disclosed. The method comprises selecting a desired antenna configuration from a plurality of antenna configuration patterns, with the selected antenna configuration forming at least one reconfigurable antenna from reconfigurable antenna array elements. The method validates the formation of the selected antenna configuration to determine antenna performance of the at least one reconfigurable antenna.

  7. Development of a 2D temperature measurement technique for combustion diagnostics using 2-line atomic fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Johan

    2001-01-01

    The present thesis is concerned with the development and application of a novel planar laser-induced fluorescence (PLIF) technique for temperature measurements in a variety of combusting flows. Accurate measurement of temperature is an essential task in combustion diagnostics, since temperature is one of the most fundamental quantities for the characterization of combustion processes. The technique is based on two-line atomic fluorescence (TLAF) from small quantities of atomic indium (In) seeded into the fuel. It has been developed from small-scale experiments in laboratory flames to the point where practical combustion systems can be studied. The technique is conceptually simple and reveals temperature information in the post-flame regions. The viability of the technique has been tested in three extreme measurement situations: in spark ignition engine combustion, in ultra-lean combustion situations such as lean burning aero-engine concepts and, finally, in fuel-rich combustion. TLAF was successfully applied in an optical Sl engine using isooctane as fuel. The wide temperature sensitivity, 700 - 3000 K, of the technique using indium atoms allowed measurements over the entire combustion cycle in the engine to be performed. In applications in lean combustion a potential problem caused by the strong oxidation processes of indium atoms was encountered. This limits measurement times due to deposits of absorbing indium oxide on measurement windows. The seeding requirement is a disadvantage of the technique and can be a limitation in some applications. The results from experiments performed in sooting flames are very promising for thermometry measurements in such environments. Absorption by hydrocarbons and other native species was found to be negligible. Since low laser energies and low seeding concentrations could be used, the technique did not, unlike most other incoherent optical thermometry techniques, suffer interferences from LII of soot particles or LIF from PAH

  8. Arcjet plasma plume effect on a microwave reflector antenna

    International Nuclear Information System (INIS)

    A configuration is described to measure the effect of the plasma produced by an arcjet thruster on a reflector antenna. The diagnostic consists of a small movable rf probe coupled to a Hewlett--Packard 8510 network analyzer. Because the perturbation is expected to be small (<10 degree phase shift), wall reflections are an important consideration. To minimize their effect we use Fourier transform gating techniques

  9. Z-pinch diagnostics, plasma and liner instabilities and new x-ray techniques

    International Nuclear Information System (INIS)

    Pulse power experiments of the last several decades have contributed greatly to the understanding of high temperature and high density plasmas and, more recently, to the study of hydrodynamic effects in thick imploding cylinders. Common to all these experiments is the application of a large current pulse to a cylindrically symmetric load, with the resulting Lorenz force compressing the load to produce hydrodynamic motion and/or high temperature, high density plasma. In Los Alamos, Pulsed power experiments are carried out at two facilities. Experiments at low current (from several million to ten million Amperes) are conducted on the Pegasus II capacitor bank. Experiments with higher currents (10's to 100's MA range) are performed in Ancho Canyon with the explosively driven Procyon and MAGO magnetic flux compression generator systems. In this paper, the authors present a survey of diagnostic capabilities and results from several sets of experiments. First, they discuss the initiation and growth of instabilities in plasmas generated from the implosion of hollow z-pinches in the pegasus and Procyon experiments. Next they discuss spectroscopic data from the plasmas produced by the MAGO system. They also show time resolved imaging data from thick (∼ .4 mm) liner implosions. Finally, the authors discuss improvements to x-ray and visible light imaging and spectrographic diagnostic techniques. The emphasis of this paper is not so much a detailed discussion of the experiments, but a presentation of imaging and spectroscopic results and the implications of these observations to the experiments

  10. The diagnostic rules of peripheral lung cancer preliminary study based on data mining technique

    Institute of Scientific and Technical Information of China (English)

    Yongqian Qiang; Youmin Guo; Xue Li; Qiuping Wang; Hao Chen; Duwu Cui

    2007-01-01

    Objective: To discuss the clinical and imaging diagnostic rules of peripheral lung cancer by data mining technique, and to explore new ideas in the diagnosis of peripheral lung cancer, and to obtain early-stage technology and knowledge support of computer-aided detecting (CAD). Methods: 58 cases of peripheral lung cancer confirmed by clinical pathology were collected. The data were imported into the database after the standardization of the clinical and CT findings attributes were identified. The data was studied comparatively based on Association Rules (AR) of the knowledge discovery process and the Rough Set (RS) reduction algorithm and Genetic Algorithm(GA) of the generic data analysis tool (ROSETTA), respectively. Results: The genetic classification algorithm of ROSETTA generates 5 000 or so diagnosis rules. The RS reduction algorithm of Johnson's Algorithm generates 51 diagnosis rules and the AR algorithm generates 123 diagnosis rules. Three data mining methods basically consider gender, age,cough, location, lobulation sign, shape, ground-glass density attributes as the main basis for the diagnosis of peripheral lung cancer. Conclusion: These diagnosis rules for peripheral lung cancer with three data mining technology is same as clinical diagnostic rules, and these rules also can be used to build the knowledge base of expert system. This study demonstrated the potential values of data mining technology in clinical imaging diagnosis and differential diagnosis.

  11. Microwave antenna holography

    Science.gov (United States)

    Rochblatt, David J.; Seidel, Boris L.

    1992-01-01

    This microwave holography technique utilizes the Fourier transform relation between the complex far field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of data processing presented here was successfully applied to the Deep Space Network (DSN) 34-m beam waveguide antennas. The antenna performance was improved at all operating frequencies by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32 GHz), the estimated improvement is 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.

  12. Uncertainty Management for Diagnostics and Prognostics of Batteries using Bayesian Techniques

    Science.gov (United States)

    Saha, Bhaskar; Goebel, kai

    2007-01-01

    Uncertainty management has always been the key hurdle faced by diagnostics and prognostics algorithms. A Bayesian treatment of this problem provides an elegant and theoretically sound approach to the modern Condition- Based Maintenance (CBM)/Prognostic Health Management (PHM) paradigm. The application of the Bayesian techniques to regression and classification in the form of Relevance Vector Machine (RVM), and to state estimation as in Particle Filters (PF), provides a powerful tool to integrate the diagnosis and prognosis of battery health. The RVM, which is a Bayesian treatment of the Support Vector Machine (SVM), is used for model identification, while the PF framework uses the learnt model, statistical estimates of noise and anticipated operational conditions to provide estimates of remaining useful life (RUL) in the form of a probability density function (PDF). This type of prognostics generates a significant value addition to the management of any operation involving electrical systems.

  13. Probabilistic techniques using Monte Carlo sampling for multi- component system diagnostics

    International Nuclear Information System (INIS)

    We outline the structure of a new approach at multi-component system fault diagnostics which utilizes detailed system simulation models, uncertain system observation data, statistical knowledge of system parameters, expert opinion, and component reliability data in an effort to identify incipient component performance degradations of arbitrary number and magnitude. The technique involves the use of multiple adaptive Kalman filters for fault estimation, the results of which are screened using standard hypothesis testing procedures to define a set of component events that could have transpired. Latin Hypercube sample each of these feasible component events in terms of uncertain component reliability data and filter estimates. The capabilities of the procedure are demonstrated through the analysis of a simulated small magnitude binary component fault in a boiling water reactor balance of plant. The results show that the procedure has the potential to be a very effective tool for incipient component fault diagnosis

  14. Biomolecular urease thin films grown by laser techniques for blood diagnostic applications

    International Nuclear Information System (INIS)

    Matrix assisted pulsed laser evaporation (MAPLE) was used for growing urease thin films designed for bio-sensor applications in clinical diagnostics. The targets exposed to laser radiation were made from a frozen composite manufactured by dissolving biomaterials in distilled water. We used a UV KrF* (λ = 248 nm, τFWHM ≅ 30 ns, ν = 10 Hz) excimer source for multipulse laser irradiation of the frozen targets cooled with Peltier elements. The laser source was operated at an incident fluence of 0.4 J/cm2. Urease activity and kinetics were assayed by the Worthington method that monitors urea hydrolysis by coupling ammonia production to a glutamate dehydrogenase reaction. A decrease in absorbance was measured at 340 nm and correlated with the enzymatic activity of urease. We show that the urease films obtained by MAPLE techniques remain active up to three months after deposition.

  15. New Diagnostic, Launch and Model Control Techniques in the NASA Ames HFFAF Ballistic Range

    Science.gov (United States)

    Bogdanoff, David W.

    2012-01-01

    This report presents new diagnostic, launch and model control techniques used in the NASA Ames HFFAF ballistic range. High speed movies were used to view the sabot separation process and the passage of the model through the model splap paper. Cavities in the rear of the sabot, to catch the muzzle blast of the gun, were used to control sabot finger separation angles and distances. Inserts were installed in the powder chamber to greatly reduce the ullage volume (empty space) in the chamber. This resulted in much more complete and repeatable combustion of the powder and hence, in much more repeatable muzzle velocities. Sheets of paper or cardstock, impacting one half of the model, were used to control the amplitudes of the model pitch oscillations.

  16. Injected Internal Target Technique, (IT)2, diagnostic development program. Final technical report

    International Nuclear Information System (INIS)

    This report describes the work performed by JAYCOR on the development of the Injected Internal Target Technique, (IT)2, diagnostic system during the period from 1 September 1983 to 31 August 1985. The (IT)2 apparatus was developed to provide a means for making localized measurements of the electron density and electron temperature of a hot electron plasma. The measurement process is based on the local enhancement of x-ray emission (bremsstrahlung) when a beam of high-atomic-number target atoms are injected into a hot electron plasma. Also, characteristic x-ray emission at the K-alpha energy of the injected target atoms is produced if the energy of the colliding plasma electrons exceeds the threshold energy for K-shell ionization. Spectral energy analysis of the bremsstrahlung and K-shell emission data yields the electron temperature and electron density, respectively. 3 refs., 7 figs

  17. IERIAS: inference engine for reactor accident diagnostic system using knowledge engineering technique

    International Nuclear Information System (INIS)

    This report describes an inference engine IERIAS which has been devoloped for a diagnostic system to identify the cause and type of an abnormal transient of a reactor plant. This system using knowledge engineering technique consists of a knowledge base and an inference engine. The inference engine IERIAS is designed so as to treat time-varying data of a plant. The major features of IERIAS are ; (1) histroy of transients can be treated, (2) knowledge base can be divided into some knowledge units, (3) program language UTILISP is used which is suitable for symbolic data manipulation. Inference was made using IERIAS with a knowledge base which was created from simulated results of various transients by a PWR plant simulator. The results showed a good applicability of IERIAS for reactor diagnosis. (author)

  18. Computer-Aided Diagnostic (CAD) Scheme by Use of Contralateral Subtraction Technique

    Science.gov (United States)

    Nagashima, Hiroyuki; Harakawa, Tetsumi

    We developed a computer-aided diagnostic (CAD) scheme for detection of subtle image findings of acute cerebral infarction in brain computed tomography (CT) by using a contralateral subtraction technique. In our computerized scheme, the lateral inclination of image was first corrected automatically by rotating and shifting. The contralateral subtraction image was then derived by subtraction of reversed image from original image. Initial candidates for acute cerebral infarctions were identified using the multiple-thresholding and image filtering techniques. As the 1st step for removing false positive candidates, fourteen image features were extracted in each of the initial candidates. Halfway candidates were detected by applying the rule-based test with these image features. At the 2nd step, five image features were extracted using the overlapping scale with halfway candidates in interest slice and upper/lower slice image. Finally, acute cerebral infarction candidates were detected by applying the rule-based test with five image features. The sensitivity in the detection for 74 training cases was 97.4% with 3.7 false positives per image. The performance of CAD scheme for 44 testing cases had an approximate result to training cases. Our CAD scheme using the contralateral subtraction technique can reveal suspected image findings of acute cerebral infarctions in CT images.

  19. Current practices of diagnostic techniques requir- ing the use of ophthalmic drugs among KwaZulu- Natal optometrists*

    OpenAIRE

    K. P. Mashige; K. S. Naidoo

    2009-01-01

    In anendeavour to improve the quality of optometric eye care services in South Africa, the scope of practice was expanded to include the use of ocular diagnostic procedures such as goniosco-py that require the use of ophthalmic drugs. The purpose of this study was to assess the practices of specific diagnostic techniques (contact tonometry, 78 D/90 D lens fundus examination, binocular indirect ophthalmoscopy and gonioscopy) requiring the use of ophthalmic drugs among optometrists in KwaZulu-N...

  20. Sportsmen’s Groin—Diagnostic Approach and Treatment With the Minimal Repair Technique

    Science.gov (United States)

    Muschaweck, Ulrike; Berger, Luise Masami

    2010-01-01

    Context: Sportsmen’s groin, also called sports hernia and Gilmore groin, is one of the most frequent sports injuries in athletes and may place an athletic career at risk. It presents with acute or chronic groin pain exacerbated with physical activity. So far, there is little consensus regarding pathogenesis, diagnostic criteria, or treatment. There have been various attempts to explain the cause of the groin pain. The assumption is that a circumscribed weakness in the posterior wall of the inguinal canal, which leads to a localized bulge, induces a compression of the genital branch of the genitofemoral nerve, considered responsible for the symptoms. Methods: The authors developed an innovative open suture repair—the Minimal Repair technique—to fit the needs of professional athletes. With this technique, the circumscribed weakness of the posterior wall of the inguinal canal is repaired by an elastic suture; the compression on the nerve is abolished, and the cause of the pain is removed. In contrast with that of common open suture repairs, the defect of the posterior wall is not enlarged, the suture is nearly tension free, and the patient can return to full training and athletic activity within a shorter time. The outcome of patients undergoing operations with the Minimal Repair technique was compared with that of commonly used surgical procedures. Results: The following advantages of the Minimal Repair technique were found: no insertion of prosthetic mesh, no general anesthesia required, less traumatization, and lower risk of severe complications with equal or even faster convalescence. In 2009, a prospective cohort of 129 patients resumed training in 7 days and experienced complete pain relief in an average of 14 days. Professional athletes (67%) returned to full activity in 14 days (median). Conclusion: The Minimal Repair technique is an effective and safe way to treat sportsmen’s groin. PMID:23015941

  1. Imaging mammary diagnostics. Diagnostic techniques, archetypical findings, differential diagnostcs and interventions.. 2. rev. and enl. ed.; Bildgebende Mammadiagnostik. Untersuchungstechnik, Befundmuster, Differenzialdiagnose und Interventionen. Kartonierte Sonderausgabe

    Energy Technology Data Exchange (ETDEWEB)

    Heywang-Koebrunner, S. [Martin-Luther-Univ., Halle-Wittenberg (Germany). Klinik fuer Diagnostische Radiologie; Schreer, I. (eds.) [Mamma-Zentrum des UK Kiel (Germany). Klinik fuer Geburtshilfe und Gynaekologie

    2008-07-01

    The book includes the following chapters: I. Methodology: anamnesis and interview; clinical evidence, mammography, sonography, magnetic resonance tomography, new imaging techniques (scintigraphy, PET), transcutaneous biopsy, pre-operative marking; II. phenotypes: normal mammary glands, mastopathics, cysts, benign tumors, inflammatory diseases, in-situ carcinomas, invasive carcinomas, lymphomas, other semi-malign and malign tumors, post-traumatic, post-surgical and post-therapeutic changes, skin changes, male mamma, screening, continuative diagnostics of screening evidence and problem solving for symptomatic patients.

  2. Diagnostic imaging of the breast. Examination techniques, appearances, differential diagnosis and interventions. 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    This second German edition of the toolbook in the ''RRR'' series of Thieme Verlag gives a full account of the state of the art in diagnostic imaging of the breast. Chapters added are: - Novel imaging techniques for diagnostic evaluation of the female breast, lymph nodes and the male breast. - Digital imaging and MR mammography. - Biopsy techniques and technical tips. New features include: - Compact summaries of the available expert knowledge and experience placed at the end of each chapter. - Full integration of relevant clinical aspects. - Compact and clear description of technical aspects and features and examination techniques. - Guidelines for developing pinpointed diagnostic strategies. - Problem solving strategies for differential diagnosis of typical findings, appearances and special problems, enhanced by decision trees. - Results and recommendations on breast screening and breast imaging reporting. - International and European recommendations on quality assurance. - More than 800 illustrations and schematic drawings. (orig./CB)

  3. The use of secondary emissive capacitive probes to determine plasma potential: A new diagnostic technique

    International Nuclear Information System (INIS)

    The authors developed a new plasma potential diagnostic technique that is suitable for use in plasmas in which the electron temperature T/sub e/ is greater than 40 → 50 eV. The technique is based on secondary electron emission by plasma electrons. When T/sub e/ ≥ 40 eV, the secondary electron emission coefficient (defined as the ratio of emitted to collected electron current) is greater than 1.0. Under such circumstances it is shown that the floating potential of a glass probe inserted into a plasma with plasma potential V/sub rho/ is given by V/sub f/ = V/sub rho/ - (0.7 +- 0.2) T/sub e//e. The authors took advantage of this result to construct a secondary emission capacitive probe (SECP) of the plasma potential. This probe is much less sensitive to electron temperature variations than conventional nonemitting floating probes which differ from the plasma potential by 3.5 T/sub e//e in a hydrogen plasma. The probe consists of a glass envelope and a detecting electrode. The coupling capacitance to the plasma was measured to be 0.3 → 0.6 pf. Details of the probe construction are presented

  4. Probability-Based Diagnostic Imaging Technique Using Error Functions for Active Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Rahim Gorgin,

    2014-07-01

    Full Text Available This study presents a novel probability-based diagnostic imaging (PDI technique using error functions for active structural health monitoring (SHM. To achieve this, first the changes between baseline and current signals of each sensing path are measured, and by taking the root mean square of such changes, the energy of the scattered signal at different times can be calculated. Then, for different pairs of signal acquisition paths, an error function based on the energy of the scattered signals is introduced. Finally, the resultant error function is fused to the final estimation of the probability of damage presence in the monitoring area. As for applications, developed methods were employed to various damage identification cases, including cracks located in regions among an active sensor network with different configurations (pulse-echo and pitch-catch, and holes located in regions outside active network sensors with pitch-catch configuration. The results identified using experimental Lamb wave signals at different central frequencies corroborated that the developed PDI technique using error functions is capable of monitoring structural damage, regardless of its shape, size and location. The developed method doesn’t need direct interpretation of overlaid and dispersed lamb wave components for damage identification and can monitor damage located anywhere in the structure. These bright advantages, qualify the above presented PDI method for online structural health monitoring.

  5. Current status of diagnostic counting and imaging techniques used in nuclear medicine: a sketch

    International Nuclear Information System (INIS)

    Diagnostic procedures used in Nuclear Medicine are designed to provide information about the static and/or dynamic distribution of some particular stable or radioactive material within the patient, as well as the quantity of the material present. Thus, the static distribution of 131I in the thyroid indicates the structure of the gland, whereas changes in the distribution or in the quantity present indicate its rate of functioning. A remarkable variety of techniques, based on emission, transmission, fluorescence, and incoherent holographic imaging principles, have been developed. Both moving and fixed radiation detectors are used, and these produce planar and 3-D projections and transverse sections of the object of interest. In general, the image quality is determined by detector characteristics such as sensitivity, spatial resolution, and depth of field, as well as by the examination time, object contrast, and object intensity, which is always severely limited in the interest of a low radiation dose to the patient. Image processing techniques can be used to improve image quality by removing certain artifacts and by producing a degree of sharpening that is limited by the signal-to-noise ratio. Incoherent holography and optimum-weighted multichannel imaging are presented as two approaches to increasing the signal-to-noise ratio. Alternative criteria for the evaluation of imaging procedures are presented, with emphasis on the use of ROC curves to describe observer performance

  6. Antenna Calibration and Measurement Equipment

    Science.gov (United States)

    Rochblatt, David J.; Cortes, Manuel Vazquez

    2012-01-01

    A document describes the Antenna Calibration & Measurement Equipment (ACME) system that will provide the Deep Space Network (DSN) with instrumentation enabling a trained RF engineer at each complex to perform antenna calibration measurements and to generate antenna calibration data. This data includes continuous-scan auto-bore-based data acquisition with all-sky data gathering in support of 4th order pointing model generation requirements. Other data includes antenna subreflector focus, system noise temperature and tipping curves, antenna efficiency, reports system linearity, and instrument calibration. The ACME system design is based on the on-the-fly (OTF) mapping technique and architecture. ACME has contributed to the improved RF performance of the DSN by approximately a factor of two. It improved the pointing performances of the DSN antennas and productivity of its personnel and calibration engineers.

  7. Comparison of horizontal winds and turbulent eddy dissipation rates obtained by two different multi-receiver techniques - Spaced Antenna and Postset Beam Steering

    Science.gov (United States)

    Kumar, Shridhar; Rao, T. Narayana; Anandan, V. K.; Sureshbabu, V. N.; Arunamani, T.

    2016-01-01

    The horizontal winds and eddy dissipation rates (ε) obtained by two multi-receiver techniques, Spaced Antenna (SA) and Postset Beam Steering (PBS), are compared and contrasted, using Middle and Upper atmospheric radar measurements. Comparison of mean horizontal winds obtained by both methods indicates a good agreement in zonal and meridional winds. On the other hand, the agreement in ε derived by SA and PBS is good in the lower troposphere (below ~9 km), but the profiles of ε show some discrepancy in the upper troposphere. While the discrepancy is relatively more in layers of depleted turbulence, it is small in layers of enhanced turbulence. Comparison of signal-to-noise ratio and turbulence variations reveal that these variations are not due to specular echoes, rather due to anisotropic turbulence. The study suggests that these techniques and correction formulae for spectral width work well in the regions of enhanced turbulence but yield relatively less accurate values in regions of depleted turbulence.

  8. Development and applications of laser spectroscopic techniques related to combustion diagnostics

    International Nuclear Information System (INIS)

    Thanks to features as non-intrusiveness combined with high spatial and temporal resolution, various laser diagnostic techniques have during the last decades become of utmost importance for characterization of combustion related phenomena. In the following presentation some further development of the techniques will be highlighted aiming at a) surface temperatures using Thermographic Phosphors, TP, b) species specific, spatially and temporally resolved detection of species absorbing in the IR spectral region using polarization spectroscopy and Laser-induced fluorescence, and finally c) high speed visualization using a special designed laser system in combination with a framing camera. In terms of surface thermometry, Thermographic Phosphors have been used for many years for temperature measurements on solid surfaces. We have during the last years further developed and applied this technique for temperature measurements on burning surfaces and on materials going through phase shifts, e.g. pyrolysis and droplets. The basic principle behind this technique is to apply micron size particles to the surface of interest. By exciting the TP with a short pulse UV laser (ns), the phosphorescence will exhibit a behaviour where the spectral emission as well as the temporal decay are dependent on the temperature. It is thus possible to measure the temperature both in one and two dimensions. The presentation will include basic description of the technique as well as various applications, e.g in fire science, IC engines and gasturbines. Several of the species of interest for combustion/flow diagnostics exhibit a molecular structure which inhibits the use of conventional laser-induced fluorescence for spatially and spectrally resolved measurements. We have during the last years investigated the use of excitation and detection in the infrared region of the spectrum. Here, it is possible to detect both carbonmono/dioxide, water as well as species specific hydrocarbons. The techniques

  9. THz Antenna Phaseless Test Technique%太赫兹天线无相测试方法

    Institute of Scientific and Technical Information of China (English)

    刘灵鸽; 赵兵; 陈波

    2013-01-01

    文章给出了一种仅由幅度信息重构天线远场方向图的平面近场方法,以及由两组相互正交的线极化分量幅度信息获取圆极化天线方向图的远场(紧缩场)测试方法,并对该方法进行了实验验证。%In this paper,a method about the estimation of the far-field antenna pattern by using amplitude-only near-field measurement data is reported. Besides,circular polarization antenna pattern reconstruction from two sets of orthogonal linear polarization component′s amplitude information using far-field measurement is presented and an experiment for com-parison of the proposed and conventional methods has been down. The experimental results confirm the validity of the ap-proach.

  10. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    OpenAIRE

    Marchevsky, M.; Wang, X.; Sabbi, G.; Prestemon, S.

    2014-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01 [...

  11. Development of neutron measurement techniques in reactor diagnostics and determination of water content and water flow

    International Nuclear Information System (INIS)

    The present thesis deals with three comparatively different topics in neutron physics research. These topics are as follows: construction and experimental investigation of a new detector, capable of measuring the neutron current, and investigation of the possibility to use it for the localisation of a neutron source in a simple experimental arrangement; execution of neutron transmission measurements based on a stationary neutron generator, and the study of their suitability for determining the volume porosity of geological samples; study of the possibility for improving the accuracy of water flow measurements based on the pulsed neutron activation technique. The first subject of this thesis concerns the measurement of the neutron current by a newly constructed detector. The motivation for this work stems from a recent suggestion that the performance of core monitoring methods could be enhanced if, in addition to the scalar neutron flux, also the neutron current was measured. To this end, a current detector was based on a scintillator mounted on a fibre and a Cd layer on one side of the detector. The measurements of the 2-D neutron current were performed in an experimental system by using this detector. The efficiency of the detector in reactor diagnostics was illustrated by demonstrating that the position of a neutron source can be determined by measuring the scalar neutron flux and the neutron current in one spatial point. The results of measurement and calculation show both the suitability of the detector construction for the measurement of the neutron current vector and the use of the current in diagnostics and monitoring. The second subject of this thesis concerns fast neutron transmission measurements, based on a stationary neutron generator, for determining the volume porosity of a sample in a model experiment. Such a technique could be used in field measurements with obvious advantages in comparison with thermal neutron transmission techniques, which can

  12. Development of neutron measurement techniques in reactor diagnostics and determination of water content and water flow

    Energy Technology Data Exchange (ETDEWEB)

    Avdic, Senada

    2000-09-01

    The present thesis deals with three comparatively different topics in neutron physics research. These topics are as follows: construction and experimental investigation of a new detector, capable of measuring the neutron current, and investigation of the possibility to use it for the localisation of a neutron source in a simple experimental arrangement; execution of neutron transmission measurements based on a stationary neutron generator, and the study of their suitability for determining the volume porosity of geological samples; study of the possibility for improving the accuracy of water flow measurements based on the pulsed neutron activation technique. The first subject of this thesis concerns the measurement of the neutron current by a newly constructed detector. The motivation for this work stems from a recent suggestion that the performance of core monitoring methods could be enhanced if, in addition to the scalar neutron flux, also the neutron current was measured. To this end, a current detector was based on a scintillator mounted on a fibre and a Cd layer on one side of the detector. The measurements of the 2-D neutron current were performed in an experimental system by using this detector. The efficiency of the detector in reactor diagnostics was illustrated by demonstrating that the position of a neutron source can be determined by measuring the scalar neutron flux and the neutron current in one spatial point. The results of measurement and calculation show both the suitability of the detector construction for the measurement of the neutron current vector and the use of the current in diagnostics and monitoring. The second subject of this thesis concerns fast neutron transmission measurements, based on a stationary neutron generator, for determining the volume porosity of a sample in a model experiment. Such a technique could be used in field measurements with obvious advantages in comparison with thermal neutron transmission techniques, which can

  13. E-Textile Antennas for Space Environments

    Science.gov (United States)

    Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.

    2007-01-01

    The ability to integrate antennas and other radio frequency (RF) devices into wearable systems is increasingly important as wireless voice, video, and data sources become ubiquitous. Consumer applications including mobile computing, communications, and entertainment, as well as military and space applications for integration of biotelemetry, detailed tracking information and status of handheld tools, devices and on-body inventories are driving forces for research into wearable antennas and other e-textile devices. Operational conditions for military and space applications of wireless systems are often such that antennas are a limiting factor in wireless performance. The changing antenna platform, i.e. the dynamic wearer, can detune and alter the radiation characteristics of e-textile antennas, making antenna element selection and design challenging. Antenna designs and systems that offer moderate bandwidth, perform well with flexure, and are electronically reconfigurable are ideally suited to wearable applications. Several antennas, shown in Figure 1, have been created using a NASA-developed process for e-textiles that show promise in being integrated into a robust wireless system for space-based applications. Preliminary characterization of the antennas with flexure indicates that antenna performance can be maintained, and that a combination of antenna design and placement are useful in creating robust designs. Additionally, through utilization of modern smart antenna techniques, even greater flexibility can be achieved since antenna performance can be adjusted in real-time to compensate for the antenna s changing environment.

  14. Forced oscillation technique in the detection of smoking-induced respiratory alterations: diagnostic accuracy and comparison with spirometry

    Directory of Open Access Journals (Sweden)

    Alvaro Camilo Dias Faria

    2010-01-01

    Full Text Available INTRODUCTION: Detection of smoking effects is of utmost importance in the prevention of cigarette-induced chronic airway obstruction. The forced oscillation technique offers a simple and detailed approach to investigate the mechanical properties of the respiratory system. However, there have been no data concerning the use of the forced oscillation technique to evaluate respiratory mechanics in groups with different degrees of tobacco consumption. OBJECTIVES: (1 to evaluate the ability of the forced oscillation technique to detect smoking-induced respiratory alterations, with special emphasis on early alterations; and (2 to compare the diagnostic accuracy of the forced oscillation technique and spirometric parameters. METHODS: One hundred and seventy subjects were divided into five groups according to the number of pack-years smoked: four groups of smokers classified as 60 pack-years and a control group. The four groups of smokers were compared with the control group using receiver operating characteristic (ROC curves. RESULTS: The early adverse effects of smoking in the group with 60 pack-years, the diagnostic performance of the forced oscillation technique was similar to that observed with spirometry. CONCLUSIONS: This study revealed that forced oscillation technique parameters were able to detect early smoking-induced respiratory involvement when pathologic changes are still potentially reversible. These findings support the use of the forced oscillation technique as a versatile clinical diagnostic tool in helping with chronic obstructive lung disease prevention, diagnosis, and treatment.

  15. Circularly polarized open-loop antenna

    OpenAIRE

    Li, Rong-Lin; Fusco, Vincent F.; Nakano, Hisamatsu

    2003-01-01

    A printed circular open-loop antenna is introduced as a simple structure for producing circular polarization; the antenna is fed with a coaxial probe. By introducing a gap within the circular loop a traveling-wave current is excited and thus circularly polarized radiation can be achieved. An optimized circularly polarized antenna is designed through numerical analysis using a so-called parametric method of moment technique. Experimental verification of the new antenna is presented. The antenn...

  16. Micro strip Patch Antenna and its Applications: a Survey

    Directory of Open Access Journals (Sweden)

    Indrasen Singh

    2011-09-01

    Full Text Available The study of microstrip patch antennas has made great progress in recent years. Compared with conventional antennas, microstrip patch antennas have more advantages and better prospects. They are lighter in weight, low volume, low cost, low profile, smaller in dimension and ease of fabrication and conformity. Moreover, the microstrip patch antennas can provide dual and circular polarizations, dual-frequency operation, frequency agility, broad band-width, feedline flexibility, beam scanning omnidirectional patterning. In this paper we discuss the microstrip antenna, types of microstrip antenna, feeding techniques and application of microstrip patch antenna with their advantage and disadvantages over conventional microwave antennas.

  17. Comparative value of diagnostic imaging techniques in a cat with exophthalmos

    International Nuclear Information System (INIS)

    A mass that appeared to originate from the frontal bone and extended into retrobulbar tissues of the light orbit was imaged in a cat using ultrasound, skull radiographs, computed tomography, and magnetic resonance imaging. The cat was presented with ventrolateral strabismus, exophthalmos, and elevated nictitans membrane of the tight eye. The mass was not delineated entirely after orbital echography and survey radiography of the skull was performed. Cytologic examination of fine-needle aspirate of the mass was suggestive of a neoplastic disease. Results of computed tomography indicated lysis of the calvarium but did not delineate borders of the mass in the calvarium. Magnetic resonance imaging was then used to confirm borders of the neoplasm. Magnetic resonance imaging was the only imaging technique that delineated the entire border of the neoplasm, including in the calvarium, when compared to postmortem evaluation. Results of orbital echography, skull radiographs, or computed tomography, when used as the only diagnostic imaging modality, must be interpreted with caution when evaluating borders of retrobulbar neoplasia prior to surgical planning

  18. Spiral CT during pharmacoangiography with angiotensin II in patients with pancreatic disease. Technique and diagnostic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, C.; Mihara, N.; Hosomi, N.; Inoue, E.; Fujita, M. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Diagnostic Radiology; Ohigashi, H.; Ishikawa, O. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Surgery; Nakaizumi, A. [Osaka Medical Center for Cancer and Cardiovascular Deseases (Japan). Dept. of Internal Medicine; Ishiguro, S. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Pathology

    1998-03-01

    Purpose: To compare the diagnostic efficacy of pancreatic pharmacoangiographic CT using angiotensin II with conventional angiographic CT. Material and Methods: Eighteen patients with space-occupying pancreatic disease were examined in this study. Pharmacoangiographic CT was performed with a 1-3-{mu}/6-ml solution of angiotensin II injected through a catheter into the celiac artery during spiral CT. Results: In 17 of the 18 (94%) patients, the area of pancreatic parenchymal enhancement was the same or larger at pharmacoangiographic CT than at conventional angiographic CT. The attenuation value of the pancreatic parenchyma was significantly increased at pharmacoangiographic CT (p=0.0010). Although the attenuation value of tumors was also increased on images obtained after the injection of angiotensin II, the tumor-to-pancreas contrast was significantly greater at pharmacoangiographic CT (p=0.0479). The mean differences in attenuation between tumor and pancreas at angiographic CT with and without angiotensin II were respectively 182 HU and 115 HU. Conclusion: Pharmacoangiographic CT with angiotensin II proved superior to conventional angiographic CT in the diagnosis of pancreatic disease. We therefore recommend it as a supplementary technique at the angiographic examination of patients with suspected pancreatic tumor. (orig.).

  19. Practical X-ray diagnostics orthopedics and trauma surgery. Indication, adjustment technique and radiation protection

    International Nuclear Information System (INIS)

    The book on X-ray diagnostics in orthopedics and trauma surgery includes the following chapters: 1. Introduction: radiation protection, equipment technology radiological diagnostics of skeleton carcinomas, specific aspects of trauma surgery, special aspects of skeleton radiology for children. 2. X-ray diagnostics of different anatomical regions: ankle joint, knee, hips and pelvis, hand and wrist joint, elbow, shoulder, spinal cord. 3. Appendix: radiation protection according to the X-ray regulations.

  20. Kinetic and Diagnostic Studies of Molecular Plasmas Using Laser Absorption Techniques

    International Nuclear Information System (INIS)

    Within the last decade mid infrared absorption spectroscopy between 3 and 20 μm, known as Infrared Laser Absorption Spectroscopy (IRLAS) and based on tuneable semiconductor lasers, namely lead salt diode lasers, often called tuneable diode lasers (TDL), and quantum cascade lasers (QCL) has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry of molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, organo-silicon and boron compounds has lead to further applications of IRLAS because most of these compounds and their decomposition products are infrared active. IRLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species, which is of particular importance for the investigation of reaction kinetics. Information about gas temperature and population densities can also be derived from IRLAS measurements. A variety of free radicals and molecular ions have been detected, especially using TDLs. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of infrared spectroscopic techniques to industrial requirements. The recent development of QCLs offers an attractive new option for the monitoring and control of industrial plasma processes as well as for highly time-resolved studies on the kinetics of plasma processes. The aim of the present article is threefold: (i) to review recent achievements in our understanding of molecular phenomena in plasmas (ii) to report on selected studies of the spectroscopic properties and kinetic behaviour of radicals, and (iii) to describe the current status of advanced instrumentation for TDLAS in the mid infrared

  1. Diagnostic value of the lfuoroscopic triggering 3D LAVA technique for primary liver cancer

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yong Shen; Chun-Hua Chai; Wen-Bo Xiao; Qi-Dong Wang

    2010-01-01

    BACKGROUND: Primary liver cancer (PLC) is one of the common malignant tumors. Liver acquisition with acceleration volume acquisition (LAVA), which allows simultaneous dynamic enhancement of the hepatic parenchyma and vascu-lature imaging, is of great help in the diagnosis of PLC. This study aimed to evaluate application of the lfuoroscopic triggering 3D LAVA technique in the imaging of PLC and liver vasculature. METHODS: The clinical data and imaging ifndings of 38 adults with PLC (22 men and 16 women;average age 52 years), pathologically conifrmed by surgical resection or biopsy, were collected and analyzed. All magnetic resonance images were obtained with a 1.5-T system (General Electrics Medical Systems) with an eight-element body array coil and application of the lfuoroscopic triggering 3D LAVA technique. Overall image quality was assessed on a 5-point scale by two experienced radiologists. All the nodules and blood vessel were recorded and compared. The diagnostic accuracy and feasibility of LAVA were evaluated. RESULTS: Thirty-eight patients gave high quality images of 72 nodules in the liver for diagnosis. The accuracy of LAVA was 97.2% (70/72), and the coincidence rate between the extent of tumor judged by dynamic enhancement and pathological examination was 87.5%(63/72). Displayed by the maximum intensity projection reconstruction, nearly all cases gave satisfactory images of branchesⅢandⅣof the hepatic artery. Furthermore, small early-stage enhancing hepatic lesions and the parallel portal vein were also well displayed. CONCLUSIONS: Sequence of LAVA provides good multi-phase dynamic enhancement scanning of hepatic lesions. Combined with conventional scanning technology, LAVA effectively and safely displays focal hepatic lesions and the relationship between tumor and normal tissues, especially blood vessels.

  2. Development of an Accident Diagnostic Scheme Using Artificial Intelligence Techniques (I)

    International Nuclear Information System (INIS)

    As a means to effectively manage the severe nuclear accidents, it is important to identify and diagnose the accident initiating events during an initial short time interval after the accidents by observing the major controlling parameters. Main objective of this study is to develop the diagnostic approach for the accurate prediction of accident initiating events using artificial intelligence techniques. For this, first, a variety of artificial intelligence techniques such as Finn, Gmbh, and Sm were examined through this study. Among them, Sc and Gmbh model were assessed as a useful approach to predict the break location and the break size of Local. In order to verify the proposed algorithm, the 111 accident simulation data (based on Map) were applied to train the Sc and Gmbh models, and the test data was used to independently verify whether or not the SVC and GMDH models work well. The analysis of the maximum errors and RMS errors, and the performance of the GMDH according to the existence of measurement errors and SIS actuation showed that the proposed SVC and GMDH models can accurately classify the break locations and accurately predict the break size. As the time-integrated signals were used for inputs into the GMDH model within a period of 60 second after a reactor scram, the actuation of the safety systems such as safety injection system (SIS), auxiliary feed water system, and containment spray system, were not considered in this study. It is because the initial 60 second time-integrated signals were used and the safety systems usually start to actuate after a more than 60 second time delay after the reactor scram

  3. Current practices of diagnostic techniques requir- ing the use of ophthalmic drugs among KwaZulu- Natal optometrists*

    Directory of Open Access Journals (Sweden)

    K. P. Mashige

    2009-12-01

    Full Text Available In anendeavour to improve the quality of optometric eye care services in South Africa, the scope of practice was expanded to include the use of ocular diagnostic procedures such as goniosco-py that require the use of ophthalmic drugs. The purpose of this study was to assess the practices of specific diagnostic techniques (contact tonometry, 78 D/90 D lens fundus examination, binocular indirect ophthalmoscopy and gonioscopy requiring the use of ophthalmic drugs among optometrists in KwaZulu-Natal (KZN province. These specific techniques are referred to as diagnostic procedures in this article. A questionnaire containing information on demography and practice of these specific techniques was sent to all 213 KwaZulu-Natal registered optometrists who owned private practices. One hundred and thirty two completed questionnaires were received, a response rate of 62%. One hundred and seventeen (55% of the questionnaires were included in the analysis of which 55% of the respondents were females and 45% were males. Sixty two optometrists (53% were certified in di-agnostic procedures but many procedures were not being practiced. These procedures and the percentage respondents were: Contact tonometry (60%, 78 D/90 D lens fundus examination (60%, binocular indirect ophthalmoscopy (84% and gonioscopy (78%. Also, among these certified respondents (62 optometrists, a significant proportion (60% disagreed when asked if they were confident and proficient in performing the relevant diagnostic procedures. Many, (61% agreed that lack of incentives discouraged them from routinely performing the procedures. More than half (58%, agreed that chair time was an important factor in deciding whether or not to perform these diagnostic procedures. Of the total respondents (117, 86% agreed that they were confident about the accuracy of their referrals and less than half (45% disagreed that diagnostic procedures should be the sole responsibility of ophthalmologists. Less than

  4. Reliability of diagnostic techniques for identification of fluidal and less fluidal variants of Clavibacter michiganensis subsp. michiganensis

    Czech Academy of Sciences Publication Activity Database

    Kokošková, B.; Mráz, Ivan; Fousek, Jan

    2008-01-01

    Roč. 90, č. 3 (2008), S2.360. ISSN 1125-4653. [International Congress of Plant Pathology "Healthy and Safe Food for Everybody"/9./. 24.08.2009-29.08.2008, Torino] R&D Projects: GA MZe QH71229 Institutional research plan: CEZ:AV0Z50510513 Keywords : plant diseases * Clavibacter michiganensis * diagnostic techniques Subject RIV: EE - Microbiology, Virology

  5. ITPA Assessment of ITER Microwave Diagnostic Design Issues

    International Nuclear Information System (INIS)

    Full text: The microwave-based diagnostic suite proposed for ITER includes Electron Cyclotron Emission, Reflectometry, Collective Thomson Scattering and Refractometry. Their common feature is the use of simple in-vessel metallic antennas and waveguide transmission lines (front-end components) which are relatively insensitive to radiation damage. However, once installed they will be difficult to replace or modify, hence, their careful design is a pressing issue. In contrast, the backend microwave transceivers (which are well developed and can employ the latest technology) will be accessible and less problematic. Here, several topics critical to the overall diagnostic designs and component selection are assessed. These include the provision for in-situ component and system calibration. E.g., initial performance measurements (losses, reflections, mode-conversion) are required to allow identification of component degradation. All the microwave diagnostics will be susceptible to stray radiation damage from non-absorbed ECRH and CTS gyrotron beams or from fast electron generated Bremsstrahlung. Various options and techniques, such as combinations of fast acting shutters, waveguide filters, fuses etc. have been identified to protect the sensitive diagnostic electronics and TL components, such as polarization splitters etc. The Low- Field-Side Reflectometer system is at a crucial design phase — systematic studies of the design drivers as well as the placement and alignment of the antennas using beam-tracing codes have been performed. A major issue is the sensitivity of the probing beam to vertical movements of the plasma column, which is linked to the selection of antenna gain and placement, monostatic vs bistatic antenna arrangements, and fixed antenna alignments vs steerable antennas. The timely assessment of these diagnostic issues has directly impacted the detailed diagnostic designs — which will shortly be placed in the hands of the respective ITER domestic

  6. Diagnostics of Aerial Systems

    OpenAIRE

    Milan Simko; Milan Sebok; Milan Chupac

    2003-01-01

    Paper deals with the problem of thermovission and its application i diagnostic od antenna system for radio transmitters. on the bockrand of above mentioned theory laboratory measurements and measurements in the conditions of performance process were performed.

  7. Diagnostic value of endobronchial and endoscopic ultrasound-guided fine needle aspiration for accessible lung cancer lesions after non-diagnostic conventional techniques: a prospective study

    International Nuclear Information System (INIS)

    Lung cancer diagnosis is usually achieved through a set of bronchoscopic techniques or computed tomography guided-transthoracic needle aspiration (CT-TTNA). However these procedures have a variable diagnostic yield and some patients remain without a definite diagnosis despite being submitted to an extensive workup. The aim of this study was to evaluate the efficacy and cost of linear endobronchial (EBUS) and endoscopic ultrasound (EUS) guided fine needle aspiration (FNA), performed with one echoendoscope, for the diagnosis of suspicious lung cancer lesions after failure of conventional procedures. One hundred and twenty three patients with an undiagnosed but suspected malignant lung lesion (paratracheal, parabronchial, paraesophageal) or with a peripheral lesion and positron emission tomography positive mediastinal lymph nodes who had undergone at least one diagnostic flexible bronchoscopy or CT-TTNA attempt were submitted to EBUS and EUS-FNA. Patients with endobronchial lesions were excluded. Of the 123 patients, 88 had a pulmonary nodule/mass and 35 were selected based on mediastinal PET positive lymph nodes. Two patients were excluded because an endobronchial mass was detected at the time of the procedure. The target lesion could be visualized in 121 cases and FNA was performed in 118 cases. A definitive diagnosis was obtained in 106 cases (87.6%). Eighty-eight patients (72.7%) had non-small cell lung cancer, 15 (12.4%) had small cell lung cancer and metastatic disease was found in 3 patients (2.5%). The remaining 15 negative cases were subsequently diagnosed by surgical procedures. Twelve patients (9.9%) had a malignant tumor and in 3 (2.5%) a benign lesion was found. The overall sensitivity, specificity, positive and negative predictive values of EBUS and EUS-FNA to diagnose malignancy were 89.8%, 100%, 100% and 20.0% respectively. The diagnostic accuracy was 90.1% in a population with 97.5% prevalence of cancer. The ultrasonographic approach avoided expensive

  8. Breast Cancer-Related Arm Lymphedema: Incidence Rates, Diagnostic Techniques, Optimal Management and Risk Reduction Strategies

    International Nuclear Information System (INIS)

    As more women survive breast cancer, long-term toxicities affecting their quality of life, such as lymphedema (LE) of the arm, gain importance. Although numerous studies have attempted to determine incidence rates, identify optimal diagnostic tests, enumerate efficacious treatment strategies and outline risk reduction guidelines for breast cancer–related lymphedema (BCRL), few groups have consistently agreed on any of these issues. As a result, standardized recommendations are still lacking. This review will summarize the latest data addressing all of these concerns in order to provide patients and health care providers with optimal, contemporary recommendations. Published incidence rates for BCRL vary substantially with a range of 2–65% based on surgical technique, axillary sampling method, radiation therapy fields treated, and the use of chemotherapy. Newer clinical assessment tools can potentially identify BCRL in patients with subclinical disease with prospective data suggesting that early diagnosis and management with noninvasive therapy can lead to excellent outcomes. Multiple therapies exist with treatments defined by the severity of BCRL present. Currently, the standard of care for BCRL in patients with significant LE is complex decongestive physiotherapy (CDP). Contemporary data also suggest that a multidisciplinary approach to the management of BCRL should begin prior to definitive treatment for breast cancer employing patient-specific surgical, radiation therapy, and chemotherapy paradigms that limit risks. Further, prospective clinical assessments before and after treatment should be employed to diagnose subclinical disease. In those patients who require aggressive locoregional management, prophylactic therapies and the use of CDP can help reduce the long-term sequelae of BCRL.

  9. Breast Cancer-Related Arm Lymphedema: Incidence Rates, Diagnostic Techniques, Optimal Management and Risk Reduction Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Chirag [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States); Vicini, Frank A., E-mail: fvicini@beaumont.edu [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States)

    2011-11-15

    As more women survive breast cancer, long-term toxicities affecting their quality of life, such as lymphedema (LE) of the arm, gain importance. Although numerous studies have attempted to determine incidence rates, identify optimal diagnostic tests, enumerate efficacious treatment strategies and outline risk reduction guidelines for breast cancer-related lymphedema (BCRL), few groups have consistently agreed on any of these issues. As a result, standardized recommendations are still lacking. This review will summarize the latest data addressing all of these concerns in order to provide patients and health care providers with optimal, contemporary recommendations. Published incidence rates for BCRL vary substantially with a range of 2-65% based on surgical technique, axillary sampling method, radiation therapy fields treated, and the use of chemotherapy. Newer clinical assessment tools can potentially identify BCRL in patients with subclinical disease with prospective data suggesting that early diagnosis and management with noninvasive therapy can lead to excellent outcomes. Multiple therapies exist with treatments defined by the severity of BCRL present. Currently, the standard of care for BCRL in patients with significant LE is complex decongestive physiotherapy (CDP). Contemporary data also suggest that a multidisciplinary approach to the management of BCRL should begin prior to definitive treatment for breast cancer employing patient-specific surgical, radiation therapy, and chemotherapy paradigms that limit risks. Further, prospective clinical assessments before and after treatment should be employed to diagnose subclinical disease. In those patients who require aggressive locoregional management, prophylactic therapies and the use of CDP can help reduce the long-term sequelae of BCRL.

  10. Use of sting-response techniques for simulate diagnostics in human esophagus

    International Nuclear Information System (INIS)

    In this work a study of simulation of the gamma graphic studies that are carried out in human esophagus in the Dept. of Nuclear Medicine of the 'Celestino Hernandez Robau Hospital of Santa Clara is presented. For the investigation tubular reactors were used and sting-response techniques with radioactive tracer of Technetium 99 metastable to a concentration of 1 mCi and several flows were applied. The distribution curves of residences times were obtained, those that respond to an equation of the type: Y = A + B exp (- exp((x-C)/D)) - ((x-C/D)+1). They were also carried out, optimizations studies of the doses of the radioactive to give to the patients from 1 mCi (that is the one used in studies) up to 0,5 mCi, and the influences on the obtained distributions of residence time were analyzed. It was confirmed the possibility to lower the doses with clear information of the signal. It was also carried out a simulation of the attenuation of the radiations that takes place in the patients by the interposition of tissues among the analyzed organ, and the detection equipment. It was used paraffin for tissue simulation. It was found the almost independence of the intensity of the radiations with the thickness, for the assayed doses. Lastly it was found a complex mathematical model that responds to the diagnostic curves obtained in these studies, being correlated the coefficients of the pattern with the most important physical parameters of the system, giving it a practical and useful value, all time that the error among the values that this it predicts and the experimental ones do not surpass of 5%. (Author)

  11. Uncertainty Management for Diagnostics and Prognostics of Batteries using Bayesian Techniques

    Data.gov (United States)

    National Aeronautics and Space Administration — Uncertainty management has always been the key hurdle faced by diagnostics and prognostics algorithms. A Bayesian treatment of this problem provides an elegant and...

  12. Theory and practice of the FFT/matrix inversion technique for probe-corrected spherical near-field antenna measurements with high-order probes

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey; Nielsen, Jeppe Majlund;

    2010-01-01

    A complete antenna pattern characterization procedure for spherical near-field antenna measurements employing a high-order probe and a full probe correction is described. The procedure allows an (almost) arbitrary antenna to be used as a probe. Different measurement steps of the procedure and the...... associated data processing are described in detail, and comparison to the existing procedure employing a first-order probe is made. The procedure is validated through measurements....

  13. Diagnostic accuracy of contrast-enhanced MR angiography in severe carotid stenosis: meta-analysis with metaregression of different techniques

    International Nuclear Information System (INIS)

    Contrast-enhanced magnetic resonance angiography (CE-MRA) has become a well-established noninvasive imaging method for the assessment of severe carotid stenosis (70-99% by NASCET criteria). However, CE-MRA is not a standardised technique, but encompasses different concurrent techniques. This review analyses possible differences. A bivariate random effects meta-analysis of 17 primary diagnostic accuracy studies confirmed a high pooled sensitivity of 94.3% and specificity of 93.0% for carotid CE-MRA in severe carotid stenosis. Sensitivity was fairly uniform among the studies, while specificity showed significant variation (I 2 = 73%). Metaregressions found significant differences for specificity with two covariates: specificity was higher when using not only maximum intensity projection (MIP) images, but also three-dimensional (3D) images (P = 0.01). Specificity was also higher with electronic images than with hardcopies (P = 0.02). The timing technique (bolus-timed, fluoroscopically triggered or time-resolved) did not result in any significant differences in diagnostic accuracy. Some nonsignificant trends were found for the percentages of severe carotid disease, acquisition time and voxel size. In conclusion, in CE-MRA of severe carotid stenosis the three major timing techniques yield comparably high diagnostic accuracy, electronic images are more specific than hardcopies, and 3D images should be used in addition to MIP images to increase the specificity. (orig.)

  14. Antenna reconfiguration using metasurfaces

    OpenAIRE

    Zhu, H; Cheung, WSW; Yuk, TI

    2014-01-01

    The paper describes the designs of a frequency-reconfigurable, polarization reconfigurable and pattern reconfigurable antennas using metasurfaces (MS). The frequency-reconfigurable and polarization reconfigurable antennas are composed of a simple circular patch antenna or slot antenna as the source antenna and a circular MS with the same diameter, with both source antenna and MS implemented using planar technology. The pattern reconfigurable antenna is composed of a circular patch antenna as ...

  15. Diamond dipole active antenna

    OpenAIRE

    Bubnov, I. N.; Falkovych, I. S.; Gridin, A. A.; Stanislavsky, A. A.; Reznik, A. P.

    2015-01-01

    Advantages of the diamond dipole antenna as an active antenna are presented. Such an antenna is like an inverted bow-tie antenna, but the former has some advantages over the ordinary bow-tie antenna. It is shown that the diamond dipole antenna may be an effective element of a new antenna array for low-frequency radio astronomy as well as a communication antenna.

  16. Multi-antenna synthetic aperture radar

    CERN Document Server

    Wang, Wen-Qin

    2013-01-01

    Synthetic aperture radar (SAR) is a well-known remote sensing technique, but conventional single-antenna SAR is inherently limited by the minimum antenna area constraint. Although there are still technical issues to overcome, multi-antenna SAR offers many benefits, from improved system gain to increased degrees-of-freedom and system flexibility. Multi-Antenna Synthetic Aperture Radar explores the potential and challenges of using multi-antenna SAR in microwave remote sensing applications. These applications include high-resolution imaging, wide-swath remote sensing, ground moving target indica

  17. Advanced Surveillance, Diagnostic and Prognostic Techniques in Monitoring Structures, Systems and Components in Nuclear Power Plants

    International Nuclear Information System (INIS)

    direction of research, development and demonstration in this area. The technologies discussed in this project are intended to establish the state of the art in surveillance, diagnostics and prognostics (SDP) technologies for equipment and process health monitoring in nuclear facilities. It is also intended to identify technology gaps and research needs of the nuclear industry in the area of SDP. The report draws on the conventional SDP technologies, as well as the latest tools, algorithms and techniques that have emerged over the last few years, especially in enabling technologies including fast data acquisition, data storage, data qualification and data analysis algorithms, such as empirical and physical modelling techniques. These new tools have made it possible to identify problems earlier and with better resolution. The significance of the material presented in this report is that it contributes not only to the current needs of the nuclear industry but also to the design improvements of the next generation of reactors. For example, the nuclear industry is currently striving to operate the plants for up to 80 years or more, as the value of nuclear assets has risen in recent years, resulting partly from environmental concerns with fossil energy production, as well as increased future demand for base load electricity. This long term operation (LTO) or life extension goal of the nuclear industry has stimulated renewed interest in more frequent monitoring of equipment to guard against ageing effects, not to mention the economic benefits that SDP implementation can produce, and contributions to radiation exposure that is as low as reasonably achievable, reduction of human errors, and optimized maintenance. Together with capabilities that enhance situational awareness, the technologies described in this report will enable more holistic management of plant structures, systems and components (SSCs), maintain high capacity factor in LTO and enable higher levels of safe operation

  18. Ultrawideband antennas for microwave imaging systems

    CERN Document Server

    Denidni, Tayeb A

    2014-01-01

    This book presents ultrawideband antennas and their applications on microwave imaging. The chapters focus on recent techniques, analysis, and applications along with the future vision of this emerging field of applied electromagnetics. Several emerging topics are essayed, including dielectric resonator antennas and planar ultrawideband antennas for microwave imaging.This resource incorporates modern design concepts, analysis, and optimization techniques based on recent developments. Readers are also provided with an extensive overview of current regulations, including those related to microwav

  19. Vertical Meandering Approach for Antenna Size Reduction

    OpenAIRE

    Li Deng; Shu-Fang Li; Ka-Leung Lau; Quan Xue

    2012-01-01

    A novel vertical meandering technique to reduce the lateral size of a planar printed antenna is presented. It is implemented by dividing a conventional spiral patch into a different number of segments and placing them on different sides of the microwave substrate with vias as the connections. To confirm the validity of this technique, measured electrical performance and radiation characteristics of five antennas with different numbers of segments are compared. The smallest antenna is reduced ...

  20. A Linearly and Circularly Polarized Active Integrated Antenna

    OpenAIRE

    Khoshniat, Ali

    2011-01-01

    This thesis work presents a new harmonic suppression technique for microstrip patch antennas. Harmonic suppression in active integrated antennas is known as an effective method to improve the efficiency of amplifiers in transmitter side. In the proposed design, the antenna works as the radiating element and, at the same time, as the tuning load for the amplifier circuit that is directly matched to the antenna. The proposed active antenna architecture is easy to fabricate and is symmetric, so ...

  1. An Introduction of Aperture Coupled Microstrip Slot Antenna

    OpenAIRE

    Zarreen Aijaz; S.C Shrivastava

    2010-01-01

    A microstrip slot antenna is very small and lightweight still it has the problem of back radiation due to which power loss occurs and the SAR increases. To reduce the back lobe a technique introduces i.e. aperture coupled microstrip slot antenna which reduces the back lobe as well as increases the bandwidth of the antenna. Aperture coupled microstrip slot antenna couples the patch antenna with microstripline through an aperture.

  2. Hybrid Neural-Network: Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics Developed and Demonstrated

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2002-01-01

    As part of the NASA Aviation Safety Program, a unique model-based diagnostics method that employs neural networks and genetic algorithms for aircraft engine performance diagnostics has been developed and demonstrated at the NASA Glenn Research Center against a nonlinear gas turbine engine model. Neural networks are applied to estimate the internal health condition of the engine, and genetic algorithms are used for sensor fault detection, isolation, and quantification. This hybrid architecture combines the excellent nonlinear estimation capabilities of neural networks with the capability to rank the likelihood of various faults given a specific sensor suite signature. The method requires a significantly smaller data training set than a neural network approach alone does, and it performs the combined engine health monitoring objectives of performance diagnostics and sensor fault detection and isolation in the presence of nominal and degraded engine health conditions.

  3. A Fast Adaptive Receive Antenna Selection Method in MIMO System

    Directory of Open Access Journals (Sweden)

    Chaowei Wang

    2013-01-01

    Full Text Available Antenna selection has been regarded as an effective method to acquire the diversity benefits of multiple antennas while potentially reduce hardware costs. This paper focuses on receive antenna selection. According to the proportion between the numbers of total receive antennas and selected antennas and the influence of each antenna on system capacity, we propose a fast adaptive antenna selection algorithm for wireless multiple-input multiple-output (MIMO systems. Mathematical analysis and numerical results show that our algorithm significantly reduces the computational complexity and memory requirement and achieves considerable system capacity gain compared with the optimal selection technique in the same time.

  4. Diagnostic of a laser induced plasma by means of a CO2 laser beam-deflection technique

    International Nuclear Information System (INIS)

    In order to diagnose a laser-induced plasma of very small size with the aid of a beam-deflection technique, a cw probing CO2 laser beam which undergoes refraction and absorption by the electrons of this plasma has been employed. The resulting deflection is determined by means of a partially absorbing CaF2 wedge in conjunction with a fast HgCdTe infrared detector. By this diagnostic technique the spatial and temporal distribution of the electron density in a laser-induced plasma absorption and the actual laser power gives the possibility to estimate the electron temperature, the pressure and the velocity of the expanding plasma. (orig.)

  5. Measurement of mobile antenna systems

    CERN Document Server

    Arai, Hiroyuki

    2012-01-01

    If you're involved with the design, installation or maintenance of mobile antenna systems, this thoroughly revised and updated edition of a classic Artech book offers you the most current and comprehensive coverage of all the mandatory measurement techniques you need for your work in the field. This Second Edition presents critical new material in key areas, including radiation efficiency measurement, mobile phone usage position, and MIMO (multiple-input/multiple-output) antennas.This unique resource provides in-depth examinations of all relevant mobile antenna measurement theories, along with

  6. MIMO wireless networks channels, techniques and standards for multi-antenna, multi-user and multi-cell systems

    CERN Document Server

    Clerckx, Bruno

    2013-01-01

    This book is unique in presenting channels, techniques and standards for the next generation of MIMO wireless networks. Through a unified framework, it emphasizes how propagation mechanisms impact the system performance under realistic power constraints. Combining a solid mathematical analysis with a physical and intuitive approach to space-time signal processing, the book progressively derives innovative designs for space-time coding and precoding as well as multi-user and multi-cell techniques, taking into consideration that MIMO channels are often far from ideal. Reflecting developments

  7. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes. Determination of hydrogen concentration and blister characterization

    International Nuclear Information System (INIS)

    Heavy water reactors (HWRs) comprise significant numbers of today's operating nuclear power plants, and more are under construction. Efficient and accurate inspection and diagnostic techniques for various reactor components and systems, especially pressure tubes, are an important factor in ensuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Project (CRP) on Intercomparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. This CRP was carried out within the framework of the IAEA's Technical Working Group on Advanced Technologies for HWRs (the TWG-HWR). The TWG-HWR is a group of experts nominated by their governments and designated by the IAEA to provide advice and to support implementation of IAEA's project on advanced technologies for HWRs. The objective of the CRP was to compare non-destructive inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of this CRP participants investigated the capability of different techniques to detect and characterize flaws. During the second phase participants collaborated to detect and characterize hydride blisters and to determine the hydrogen concentration in zirconium alloys. The intention was to identify the most effective pressure tube inspection and diagnostic methods and to identify further development needs. The organizations which participated in phase 2 of this CRP are: - Comision Nacional de Energia Atomica (CNEA), Argentina; - Atomic Energy of Canada Ltd. (AECL), Chalk River Laboratories (CRL), Canada; - Bhabha Atomic Research Centre (BARC), India; - Korea Atomic Energy Research Institute (KAERI), Republic of Korea; - National Institute for Research and Development for Technical Physics (NIRDTP), Romania; - Nuclear Non-Destructive Testing Research and Services (NNDT), Romania. IAEA-TECDOC-1499

  8. Principles for new optical techniques in medical diagnostics for mHealth applications

    Science.gov (United States)

    Balsam, Joshua Michael

    Medical diagnostics is a critical element of effective medical treatment. However, many modern and emerging diagnostic technologies are not affordable or compatible with the needs and conditions found in low-income and middle-income countries and regions. Resource-poor areas require low-cost, robust, easy-to-use, and portable diagnostics devices compatible with telemedicine (i.e. mHealth) that can be adapted to meet diverse medical needs. Many suitable devices will need to be based on optical technologies, which are used for many types of biological analyses. This dissertation describes the fabrication and detection principles for several low-cost optical technologies for mHealth applications including: (1) a webcam based multi-wavelength fluorescence plate reader, (2) a lens-free optical detector used for the detection of Botulinum A neurotoxin activity, (3) a low cost micro-array reader that allows the performance of typical fluorescence based assays demonstrated for the detection of the toxin staphylococcal enterotoxin (SEB), and (4) a wide-field flow cytometer for high throughput detection of fluorescently labeled rare cells. This dissertation discusses how these technologies can be harnessed using readily available consumer electronics components such as webcams, cell phones, CCD cameras, LEDs, and laser diodes. There are challenges in developing devices with sufficient sensitivity and specificity, and approaches are presented to overcoming these challenges to create optical detectors that can serve as low cost medical diagnostics in resource-poor settings for mHealth.

  9. Sportsmen’s Groin—Diagnostic Approach and Treatment With the Minimal Repair Technique

    OpenAIRE

    Muschaweck, Ulrike; Berger, Luise Masami

    2010-01-01

    Context: Sportsmen’s groin, also called sports hernia and Gilmore groin, is one of the most frequent sports injuries in athletes and may place an athletic career at risk. It presents with acute or chronic groin pain exacerbated with physical activity. So far, there is little consensus regarding pathogenesis, diagnostic criteria, or treatment. There have been various attempts to explain the cause of the groin pain. The assumption is that a circumscribed weakness in the posterior wall of the in...

  10. Diagnostic Efficacy in Knee MRI Comparing Conventional Technique and Multiplanar Reconstruction with One-Millimeter FSE PDW Images

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Y.C.; Kim, S.S.; Chung, H.W.; Choe, B.K.; Ahn, J.H. [Dept. of Radiolog y, Kangwon National Univ. School of Medicine, Kangwon-do (Korea)

    2007-10-15

    Background: Magnetic resonance (MR) imaging has proved to be an excellent tool in diagnosing injuries of the cruciate ligaments and menisci. However, multiple planes and sometimes optimal oblique or double-oblique scan planes are needed due to the variability in the positioning of important structures, which means there is a lower throughput and longer scanning time. Purpose: To compare the performance of a 1-mm-thickness fast spin-echo (FSE) proton-density-weighted (PDW) MR imaging technique with multiplanar reconstruction (MPR) in diagnosing tears of the menisci and cruciate ligaments with that of conventional MR imaging. Material and Methods: Twenty-five consecutive patients underwent preoperative conventional and 1-mm-thickness FSE PDW MR imaging with subsequent knee arthroscopic surgery. Two musculoskeletal radiologists evaluated the status of the cruciate ligaments and menisci using two sets of MR images (method A: conventional images including seven sequences, taking 26 min; method B: 1-mm-thickness FSE PDW images with MPR, taking 7 min 20 s). The diagnostic efficacies of both methods for tears of the cruciate ligament and menisci were calculated and compared. Results: Arthroscopic surgery revealed 10 anterior cruciate ligament (ACL) tears, one posterior cruciate ligament (PCL) tear, and 26 meniscal tears. The diagnostic values of both methods were 100% for a cruciate ligament tear. The diagnostic values (sensitivity, specificity, accuracy, positive predictive value, and negative predictive value) for meniscal tears were 90%, 100%, 96%, 100%, and 94% for method A, and 95%, 100%, 98%, 100%, and 97% for method B, respectively. There were no significant differences in the diagnostic values between methods A and B. Conclusion: 1-mm-slice-thickness FSE PDW imaging with MPR showed comparable performance in diagnosing tears of the cruciate ligaments and menisci to conventional sequences but the scan time was much shorter. Therefore, this technique (method B) might

  11. UWB planar antenna technology

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Recent developments of the ultra-wideband(UWB)planar antennas are reviewed,where the progress in UWB plate monopole antennas,UWB printed monopole antennas and the UWB printed slot antennas is introduced and compared.In addition,the UWB printed antennas with the band-notched functions are also presented.

  12. Comparison of advanced optical imaging techniques with current otolaryngology diagnostics for improved middle ear assessment (Conference Presentation)

    Science.gov (United States)

    Nolan, Ryan M.; Shelton, Ryan L.; Monroy, Guillermo L.; Spillman, Darold R.; Novak, Michael A.; Boppart, Stephen A.

    2016-02-01

    Otolaryngologists utilize a variety of diagnostic techniques to assess middle ear health. Tympanometry, audiometry, and otoacoustic emissions examine the mobility of the tympanic membrane (eardrum) and ossicles using ear canal pressure and auditory tone delivery and detection. Laser Doppler vibrometry provides non-contact vibrational measurement, and acoustic reflectometry is used to assess middle ear effusion using sonar. These technologies and techniques have advanced the field beyond the use of the standard otoscope, a simple tissue magnifier, yet the need for direct visualization of middle ear disease for superior detection, assessment, and management remains. In this study, we evaluated the use of portable optical coherence tomography (OCT) and pneumatic low-coherence interferometry (LCI) systems with handheld probe delivery to standard tympanometry, audiometry, otoacoustic emissions, laser Doppler vibrometry, and acoustic reflectometry. Comparison of these advanced optical imaging techniques and current diagnostics was conducted with a case study subject with a history of unilateral eardrum trauma. OCT and pneumatic LCI provide novel dynamic spatiotemporal structural data of the middle ear, such as the thickness of the eardrum and quantitative detection of underlying disease pathology, which could allow for more accurate diagnosis and more appropriate management than currently possible.

  13. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    CERN Document Server

    Marchevsky, M; Sabbi, G; Prestemon, S

    2013-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01 [1], we show how acoustic data is connected with voltage instabilities measured simultaneously in the magnet windings during provoked extractions and current ramps to quench. Instrumentation and data analysis techniques for acoustic sensing are reviewed.

  14. Compact, Frequency Reconfigurable, Printed Monopole Antenna

    OpenAIRE

    Ricardo Gonçalves; Pedro Pinho; Nuno B. Carvalho

    2012-01-01

    This paper proposes a possible implementation of a compact printed monopole antenna, useful to operate in UMTS and WLAN bands. In order to accomplish that, a miniaturization technique based on the application of chip inductors is used in conjunction with frequency reconfiguration capability. The chip inductors change the impedance response of the monopole, allowing to reduce the resonant frequency. In order to be able to operate the antenna in these two different frequencies, an antenna recon...

  15. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes: Flaw detection and characterization [Phase 1

    International Nuclear Information System (INIS)

    Nuclear power plants with heavy water reactors (HWRs) comprise nine percent of today's operating nuclear units, and more are under construction. Efficient and accurate inspection and diagnostic techniques for various reactor components and systems are an important factor in assuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Programme (CRP) on Inter-comparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. This CRP was carried out within the frame of the IAEA Department of Nuclear Energy's Technical Working Group on Advanced Technologies for HWRs (the TWG-HWR). The TWG-HWR is a group of experts nominated by their governments and designated by the IAEA to provide advice and to support implementation of the IAEA's project on advanced technologies for HWRs. The objective of the CRP was to inter-compare non-destructive inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of this CRP, participants have investigated the capability of different techniques to detect and characterize flaws. During the second phase of this CRP, participants collaborated to detect and characterize hydride blisters and to determine the hydrogen concentration in Zirconium alloys. The intent was to identify the most effective pressure tube inspection and diagnostic methods, and to identify further development needs. The organizations that have participated in this CRP are: - The Comision Nacional de Energia Atomica (CNEA), Argentina; - Atomic Energy of Canada Ltd. (AECL); Chalk River Laboratories (CRL), Canada; - The Research Institute of Nuclear Power Operations (RINPO), China National Nuclear Corporation (CNNC), China; - Bhabha Atomic Research Centre (BARC), India; - The Korea Electric Power Research Institute (KEPRI), Republic of Korea; - The Korea Atomic Energy

  16. Advances in diagnostic techniques of toxoplasmosis%弓形虫病诊断方法研究进展

    Institute of Scientific and Technical Information of China (English)

    冯嘉轩; 赵永坤; 孟繁平; 吴泽民; 刘智; 李娜; 刘全

    2016-01-01

    Toxoplasmosis is a severe parasitic zoonosis caused byToxoplasma gondii, which poses a threat to human health. In this paper, the diagnostic techniques of toxoplasmosis and detection methods ofT. gondii were reviewed, including non-DNA-based diagnostic methods, serological assays, and molecular methods based on detection of parasite nucleic acid in hope of providing an insight into the development of novel diagnostic technologies and methods of toxoplasmosis.%弓形虫病是由弓形虫感染引起的一种严重的人兽共患寄生虫病,对人类健康造成极大威胁。本文对弓形虫病诊断技术,包括不依赖DNA检测诊断方法、血清学检测以及基于寄生虫核酸的分子生物学方法进行综述,为弓形虫病诊断技术和方法的发展提供新的思路。

  17. Stress Myocardial Perfusion Imaging in the Emergency Department - New Techniques for Speed and Diagnostic Accuracy

    Science.gov (United States)

    Harrison, Sheri D; Harrison, Mark A; Duvall, W Lane

    2012-01-01

    Emergency room evaluations of patients presenting with chest pain continue to rise, and these evaluations which often include cardiac imaging, are an increasing area of resource utilization in the current health system. Myocardial perfusion imaging from the emergency department remains a vital component of the diagnosis or exclusion of coronary artery disease as the etiology of chest pain. Recent advances in camera technology, and changes to the imaging protocols have allowed MPI to become a more efficient way of providing this diagnostic information. Compared with conventional SPECT, new high-efficiency CZT cameras provide a 3-5 fold increase in photon sensitivity, 1.65-fold improvement in energy resolution and a 1.7-2.5-fold increase in spatial resolution. With stress-only imaging, rest images are eliminated if stress images are normal, as they provide no additional prognostic or diagnostic value and cancelling the rest images would shorten the length of the test which is of particular importance to the ED population. The rapid but accurate triage of patients in an ED CPU is essential to their care, and stress-only imaging and new CZT cameras allow for shorter test time, lower radiation doses and lower costs while demonstrating good clinical outcomes. These changes to nuclear stress testing can allow for faster throughput of patients through the emergency department while providing a safe and efficient evaluation of chest pain. PMID:22708910

  18. Stress myocardial perfusion imaging in the emergency department--new techniques for speed and diagnostic accuracy.

    Science.gov (United States)

    Harrison, Sheri D; Harrison, Mark A; Duvall, W Lane

    2012-05-01

    Emergency room evaluations of patients presenting with chest pain continue to rise, and these evaluations which often include cardiac imaging, are an increasing area of resource utilization in the current health system. Myocardial perfusion imaging from the emergency department remains a vital component of the diagnosis or exclusion of coronary artery disease as the etiology of chest pain. Recent advances in camera technology, and changes to the imaging protocols have allowed MPI to become a more efficient way of providing this diagnostic information. Compared with conventional SPECT, new high-efficiency CZT cameras provide a 3-5 fold increase in photon sensitivity, 1.65-fold improvement in energy resolution and a 1.7-2.5-fold increase in spatial resolution. With stress-only imaging, rest images are eliminated if stress images are normal, as they provide no additional prognostic or diagnostic value and cancelling the rest images would shorten the length of the test which is of particular importance to the ED population. The rapid but accurate triage of patients in an ED CPU is essential to their care, and stress-only imaging and new CZT cameras allow for shorter test time, lower radiation doses and lower costs while demonstrating good clinical outcomes. These changes to nuclear stress testing can allow for faster throughput of patients through the emergency department while providing a safe and efficient evaluation of chest pain. PMID:22708910

  19. Astigmatism in reflector antennas.

    Science.gov (United States)

    Cogdell, J. R.; Davis, J. H.

    1973-01-01

    Astigmatic phase error in large parabolic reflector antennas is discussed. A procedure for focusing an antenna and diagnosing the presence and degree of astigmatism is described. Theoretical analysis is conducted to determine the nature of this error in such antennas.

  20. A directive pulse antenna

    OpenAIRE

    Titov, A.N.; Titov, A. A.

    2003-01-01

    Using quite general concepts as guidance in the design of an antenna for short pulse transmission and reception, a new type of horn-antenna has been devised. A certain variety of experimental data obtained by the antenna are presented.

  1. Antenna radome sample test report

    Science.gov (United States)

    Baker, Leonard H.; Bratton, Thomas D.

    1991-01-01

    The antenna radome sample test conducted at the Federal Aviation Administration (FAA) Technical Center by the Secondary Surveillance Systems Branch, ACN-220 is documented. The test configuration consisted of the antenna radome sample centered between the Discrete Address Beacon System's (DABS) antenna and its remote Calibration Performance Monitor Equipment (CPME). The Range and Azimuth Accuracy (RAA) diagnostic program was used to determine changes in DABS performance. There were two test objectives. The first test objective was to determine if existing FAA en route radar antenna radomes would distort the signal characteristics detected by a beacon monopulse processor system. The second test objective was to determine whether this test configuration could be used to test radome samples supplied by prospective contractors in the en route radome replacement program. The RAA diagnostic program could not determine if the radome sample depicted changes in the DABS performance. It is recommended that this test procedure be abandoned due to inconclusive test results. The prospective radome manufacturers should provide the FAA with sufficient test data to confirm that it meets the requirements of the radome procurement specification.

  2. Far-infrared imaging antenna arrays

    OpenAIRE

    Neikirk, Dean P.; Rutledge, David B.; Muha, Michael S.; Park, Hyeon; Yu, Chang-Xuan

    1982-01-01

    A far-infrared imaging antenna array has been demonstrated for the first time. The array is a line of evaporated silver bow-tie antennas on a fused-quartz substrate with bismuth-microbolometer detectors. The measured optical transfer function shows that the system is diffraction limited. This imaging array should find direct application in fusion plasma diagnostics. If the microbolometers can be replaced by more sensitive diode detectors, the array should also find application in radiometry a...

  3. Optical antennas and plasmonics

    OpenAIRE

    Park, Q-Han

    2009-01-01

    Optical antenna is a nanoscale miniaturization of radio or microwave antennas that is also governed by the rule of plasmonics. We introduce various types of optical antenna and make an overview of recent developments in optical antenna research. The role of local and surface plasmons in optical antenna is explained through antenna resonance and resonance conditions for specific metal structures are explicitly obtained. Strong electric field is shown to exist within a highly localized region o...

  4. [THE MOLECULAR TECHNIQUES OF DIAGNOSTIC OF GINGIVITIS AND PERIODONTITIS IN HIV-INFECTED PATIENTS].

    Science.gov (United States)

    Tsarev, V N; Nikolaeva, E N; Iagodina, E V; Trefilova, Yu A; Ippolitov, E V

    2016-01-01

    The examination was carried out in the Moscow clinical infectious hospital No 2 concerning 102 patients with verified diagnosis "AIDS-infection" and seropositive according results of detection of anti-HIV-antibodies in blood serum. The study was organized to analyze rate ofcolonization of gums with virulent anaerobic bacteria in HIV-infected (polymerase chain reaction) and antibodies to HIV in gingival fluid (enzyme-linked immunosorbent assay). It is established that in HIV-infected patients, in scrape from gingival sulcus dominate anaerobic bacteria P. gigngivalis and A. ctinomycetemcomitans and in case of periodontitis--P. gingivalis and T. forsythia. The received data permits recommending the test-system "Multident-5" for polymerase chain reaction diagnostic. The reagents kit "Calypte®HIV-1/2"--for enzyme-linked immunosorbent assay gingival fluid. The results of polymerase chain reaction and enzyme-linked immunosorbent assay have no impact of concomitant stomatological (periodontitis, gingivitis) and somatic pathology. PMID:27183732

  5. Diagnostic prénatal: quelles sont les techniques actuelles et futures ? (flyer)

    CERN Multimedia

    2002-01-01

    La majorité des bébés qui viennent au monde ne présentent pas d'anomalies particulières. Cependant, il faut savoir qu'environ 1 foetus 170 présente une anomalie chromosomique (défaut de la structure ou du nombre de chromosomes) qui va peser plus ou moins lourdement sur sa vie future et 1 foetus sur 100 présente une maladie génique due à un changement dans un gène. Le diagnostic prénatal a connu et connaît une formidable expansion grâce aux progrès technologiques en génétique et imagerie foetale.

  6. Diagnostic technique for measuring fusion reaction rate for inertial confinement fusion experiments at Shen Guang-III prototype laser facility

    International Nuclear Information System (INIS)

    A study is conducted using a two-dimensional simulation program (Lared-s) with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program (Lared-s) and confirmed by the experimental results. A neutron temporal diagnostic (NTD) system is developed with a high temporal resolution of ∼ 30 ps at the Shen Guang-III (SG-III) prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion

  7. A thermal technique for local ultrasound intensity measurement: part 2. Application to exposimetry on a medical diagnostic device

    International Nuclear Information System (INIS)

    Acoustic output measurements on medical ultrasound equipment are usually performed using radiation force balances to determine the output power and using hydrophones to determine pressure and intensity parameters. The local temporal-average ultrasound intensity can be measured alternatively by thermal sensors. The technique was described and prototype sensors were characterized in a preceding paper. Here, the application of such a thermal intensity sensor to the output beam characterization of a typical medical diagnostic device is described. Two transducers, a 7.5 MHz linear array and a 3.5 MHz convex array were investigated in different operating modes. For comparison, hydrophone measurements were also performed. If the spatial averaging effect is taken into account, good agreement is found between both measurement methods. The maximum deviations of the spatial-peak temporal-average intensities ISPTA obtained with the thermal sensor from the corresponding hydrophone-based results were below 12%. The simple thermal technique offers advantages for intensity measurements especially in the case of scanning and combined modes of the diagnostic device, where the synchronization between hydrophone measurements and the complex pulse emission pattern can be difficult

  8. Risk estimation in association with diagnostic techniques in the nuclear medicine service of the Camaguey Ciego de Avila Territory

    International Nuclear Information System (INIS)

    The nuclear medicine service at the Maria Curie Oncological Hospital, Camaguey, has experience of over three decades in using radiofarmaceutical imaging agents for diagnosis. Although the clinical risk associated with these techniques is negligible, it is necessary to evaluate the effective dose administered to the patient due to the introduction of radioactive substances into the body. The study of the dose administered to the patient provides useful data for evaluating the detriment associated with this medical practice, its subsequently optimization and consequently, for minimizing the stochastic effects on the patient. The aim of our paper is to study the collective effective dose administered by nuclear medicine service to Camaguey and Ciego de Avila population from 1995 to 1998 and the relative contribution to the total annual effective collective dose of the different diagnostic examinations. The studies were conducted on the basis of statistics from nuclear medicine examinations given to a population of 1102353 inhabitants since 1995. The results show that the nuclear medicine techniques of neck examinations with 1168.8 Sv man (1.11 Sv/expl), thyroid explorations with 119.6 Sv man (55.5 mSv/expl) and iodide uptake with 113.7 Sv man (14.0 mSv/expl) are the main techniques implicated in the relative contribution to the total annual effective collective dose of 1419.5 Sv man. The risk estimation in association with diagnostic techniques in the nuclear medicine service studied is globally low (total detriment: 103.6 as a result of 16232 explorations), similar to other published data

  9. Antennas in inhomogeneous media

    CERN Document Server

    Galejs, Janis; Fock, V A; Wait, J R

    2013-01-01

    Antennas in Inhomogeneous Media details the methods of analyzing antennas in such inhomogeneous media. The title covers the complex geometrical configurations along with its variational formulations. The coverage of the text includes various conditions the antennas are subjected to, such as antennas in the interface between two media; antennas in compressible isotropic plasma; and linear antennas in a magnetoionic medium. The selection also covers insulated loops in lossy media; slot antennas with a stratified dielectric or isotropic plasma layers; and cavity-backed slot antennas. The book wil

  10. Terminal Antenna Design

    OpenAIRE

    Skrivervik, A. K.; Zurcher, J. F.

    2008-01-01

    This paper introduces first some general considerations about antenna miniaturization and multi-band terminal antenna design. These general design principles are then illustrated on some practical applications.

  11. Diagnostics of Aerial Systems Diagnostics of Aerial Systems

    OpenAIRE

    Milan Chupac; Milan Sebok; Milan Simko

    2003-01-01

    Paper deals with the problem of thermovission and its application i diagnostic od antenna system for radio transmitters. on the bockrand of above mentioned theory laboratory measurements and measurements in the conditions of performance process were performed.
    Paper deals with the problem of thermovission and its application i diagnostic od antenna system for radio transmitters. on the bockrand of above mentioned theory laboratory measurements and measurements in the conditions of ...

  12. Diagnostics of Aerial Systems Diagnostics of Aerial Systems

    Directory of Open Access Journals (Sweden)

    Milan Chupac

    2003-01-01

    Full Text Available Paper deals with the problem of thermovission and its application i diagnostic od antenna system for radio transmitters. on the bockrand of above mentioned theory laboratory measurements and measurements in the conditions of performance process were performed.
    Paper deals with the problem of thermovission and its application i diagnostic od antenna system for radio transmitters. on the bockrand of above mentioned theory laboratory measurements and measurements in the conditions of performance process were performed.

  13. Optical diagnostics of gas-dynamic flows using advanced laser measurement techniques

    Science.gov (United States)

    Gross, K. P.

    1985-01-01

    Using laser-induced fluorescence to probe nitrogen flows seeded with small amounts of nitric oxide, simultaneous measurements of all three thermodynamic scalar quantities temperature, density, and pressure, were demonstrated in a supersonic turbulent boundary layer. Instrumental uncertainty is 1% for temperature and 2% for density and pressure, making the techniques suitable for measurements of turbulent fluctuations. This technology is currently being transferred to an experimental program designed to use these optical techniques in conjunction with traditional methods to make measurements in turbulent flowfields that were not possible before. A detailed descritpion of the research progress and pertinent results are presented.

  14. Millimeter-wave antennas configurations and applications

    CERN Document Server

    du Preez, Jaco

    2016-01-01

    This book comprehensively reviews the state of the art in millimeter-wave antennas, traces important recent developments and provides information on a wide range of antenna configurations and applications. While fundamental theoretical aspects are discussed whenever necessary, the book primarily focuses on design principles and concepts, manufacture, measurement techniques, and practical results. Each of the various antenna types scalable to millimeter-wave dimensions is considered individually, with coverage of leaky-wave and surface-wave antennas, printed antennas, integrated antennas, and reflector and lens systems. The final two chapters address the subject from a systems perspective, providing an overview of supporting circuitry and examining in detail diverse millimeter-wave applications, including high-speed wireless communications, radio astronomy, and radar. The vast amount of information now available on millimeter-wave systems can be daunting for researchers and designers entering the field. This b...

  15. Antenna design by simulation-driven optimization

    CERN Document Server

    Koziel, Slawomir

    2014-01-01

    This Brief reviews a number of techniques exploiting the surrogate-based optimization concept and variable-fidelity EM simulations for efficient optimization of antenna structures. The introduction of each method is illustrated with examples of antenna design. The authors demonstrate the ways in which practitioners can obtain an optimized antenna design at the computational cost corresponding to a few high-fidelity EM simulations of the antenna structure. There is also a discussion of the selection of antenna model fidelity and its influence on performance of the surrogate-based design process. This volume is suitable for electrical engineers in academia as well as industry, antenna designers and engineers dealing with computationally-expensive design problems.

  16. Advanced microwave radiometer antenna system study

    Science.gov (United States)

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

    1976-01-01

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

  17. Smart Antenna for Cellular Mobile Communication

    CERN Document Server

    Jain, R K; Agrawal, N K

    2012-01-01

    The adoption of smart / adaptive antenna techniques in future wireless systems is expected to have a significant impact on the efficient use of the spectrum, the minimization of the cost of establishing new wireless networks, the optimization of service quality and realization of transparent operation across multi technology wireless networks [1]. This paper presents brief account on smart antenna (SA) system. SAs can place nulls in the direction of interferers via adaptive updating of weights linked to each antenna element. SAs thus cancel out most of the co-channel interference resulting in better quality of reception and lower dropped calls. SAs can also track the user within a cell via direction of arrival algorithms [2]. This paper explains the architecture, evolution and how the smart / adaptive antenna differs from the basic format of antenna. The paper further explains about the radiation pattern of the antenna and why it is highly preferred in its relative field. The capabilities of smart / adaptive ...

  18. Spectroscopic techniques as a diagnostic tool for early detection of osteoporosis

    International Nuclear Information System (INIS)

    Osteoporosis (OP) a kind of bone disease, is very serious in particular for old persons, and may lead them to immobility and death. Early detection of the diseases is the first consideration for the patients to have more options to live a healthy life. The biomarkers or bonemarkers provide a promising challenge in clinical proteomics for early disease detection. In this paper, optical techniques such as Fourier Transform Infrared Spectroscopy (FTIR) and UV/Visible spectroscopy are employed to find the bone markers and emphasis has been given on noninvasive modalities for early detection of osteoporosis. Blood plasma samples procured from two groups, patients and healthy persons were tested. Both of the optical techniques revealed obvious differences in the spectra: between two groups, for example, increase in intensity for OP persons. New peaks were found at 1646, 1540, 1456 and 1077 cm-1 in FTIR spectra. Except 1588 cm-1, we showed decrease in spectral intensity of OP persons. In UV/Visible spectroscopy results, new peaks appeared in the OP patients spectra at the wavelength of 279 nm and 414 nm. These differences in the spectra of the two types samples, allow rapid and cost-effective discrimination of the potential patients with the optical techniques which were verified by the bone densitometer in the hospitals. The new and novel technique is quick, reliable and effective

  19. Application of radioactive aerosols in diagnostic techniques of bronchial obstructions in the clinical practice

    International Nuclear Information System (INIS)

    Description of a technique for early diagnosis of chronical bronchitis, that is based on analyzing of deposition patterns obtained by inhalation of radioactive aerosoles. To this effect a new atomizer has been developed that permits to draw quantitative indications from inhalation scintiscanning. (RW)

  20. Corrosion evaluation and diagnostic: use of electrochemical techniques in metal conservation

    OpenAIRE

    Letardi, Paola

    2011-01-01

    Electrochemical techniques provide several methods to analyse corrosion mechanism and to measure values such as corrosion rate on metals and alloys. They are widely used in Materials Science as a tool to characterise metals corrosion and protection. In the last ten years several applications in the wide field of metal conservation have been developed, in order to characterise the corrosion mechanism in several environments, the corrosion products, and the conservation treatments (cleaning, pr...

  1. Antenna coupled photonic wire lasers.

    Science.gov (United States)

    Kao, Tsung-Yu; Cai, Xiaowei; Lee, Alan W M; Reno, John L; Hu, Qing

    2015-06-29

    Slope efficiency (SE) is an important performance metric for lasers. In conventional semiconductor lasers, SE can be optimized by careful designs of the facet (or the modulation for DFB lasers) dimension and surface. However, photonic wire lasers intrinsically suffer low SE due to their deep sub-wavelength emitting facets. Inspired by microwave engineering techniques, we show a novel method to extract power from wire lasers using monolithically integrated antennas. These integrated antennas significantly increase the effective radiation area, and consequently enhance the power extraction efficiency. When applied to wire lasers at THz frequency, we achieved the highest single-side slope efficiency (~450 mW/A) in pulsed mode for DFB lasers at 4 THz and a ~4x increase in output power at 3 THz compared with a similar structure without antennas. This work demonstrates the versatility of incorporating microwave engineering techniques into laser designs, enabling significant performance enhancements. PMID:26191717

  2. Downsizing Antenna Technologies for Mobile and Satellite Communications

    Science.gov (United States)

    Huang, J.; Densmore, A.; Tulintseff, A.; Jamnejad, V.

    1993-01-01

    Due to the increasing and stringent functional requirements (larger capacity, longer distances, etc.) of modern day communication systems, higher antenna gains are generally needed. This higher gain implies larger antenna size and mass which are undesirable to many systems. Consequently, downsizing antenna technology becomes one of the most critical areas for research and development efforts. Techniques to reduce antenna size can be categorized and are briefly discussed.

  3. A novel coplanar slot antenna structure for wireless applications

    OpenAIRE

    Dakir, Rachid; Zbitou, Jamal; Mouhsen, Ahmed; Tribak, Abdelwahed; Mediavilla Sánchez, Ángel; Latrach, Mohamed

    2013-01-01

    This paper presents a new compact broadband coplanar slot antenna for multiple wireless communication applications which include WIMAX, RFID, WLAN and ISM bands. The antenna structure is based on the CPW-fed combined with a slot technique and a modified geometry antenna in order to enlarge the bandwidth. The antenna parameters have been investigated and optimized by using Momentum software integrated into ADS” Advanced Design System” from Agilent Technologies with a comparison of the results ...

  4. Researches on Reconfigurable Antenna in CEMLAB at UESTC

    Institute of Scientific and Technical Information of China (English)

    WANG Bing-zhong; XIAO Shao-qiu; ZHANG Yong; YANG Xue-song; WU Wei-xia

    2006-01-01

    This paper summarizes the achievement and progress in the research on reconfigurable antenna since 2001, in Computational Electromagnetics Laboratory (CEMLAB) at University of Electronic Science and Technology of China (UESTC). Several typical reconfigurable antennas are introduced, which can realize frequency, pattern or frequency-pattern reconfigurability by electrically controlling methods. Some techniques involved in the design and analysis of reconfigurable antennas are reported. At last, the development trend of reconfigurable antenna is predicted in the conclusions.

  5. Feasibility of Smart Antennas for the Small Wireless Terminals

    OpenAIRE

    Mostafa, Raqibul

    2003-01-01

    Smart antenna is a potential performance enhancement tool in a communications link that can be used at either end (transmitter or receiver) of the link in the form of beamforming or diversity operation. While receive smart antenna techniques and operations have matured over the years, transmit smart antenna is relatively a new concept that has seen its growth over the past few years. Both these smart antenna operations have been traditionally designed for base station applications. But with t...

  6. Diagnostics and Control of Natural Gas-Fired furnaces via Flame Image Analysis using Machine Vision & Artificial Intelligence Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Shahla Keyvan

    2005-12-01

    A new approach for the detection of real-time properties of flames is used in this project to develop improved diagnostics and controls for natural gas fired furnaces. The system utilizes video images along with advanced image analysis and artificial intelligence techniques to provide virtual sensors in a stand-alone expert shell environment. One of the sensors is a flame sensor encompassing a flame detector and a flame analyzer to provide combustion status. The flame detector can identify any burner that has not fired in a multi-burner furnace. Another sensor is a 3-D temperature profiler. One important aspect of combustion control is product quality. The 3-D temperature profiler of this on-line system is intended to provide a tool for a better temperature control in a furnace to improve product quality. In summary, this on-line diagnostic and control system offers great potential for improving furnace thermal efficiency, lowering NOx and carbon monoxide emissions, and improving product quality. The system is applicable in natural gas-fired furnaces in the glass industry and reheating furnaces used in steel and forging industries.

  7. Laser diagnodent: a comparative study with other diagnostic techniques; Laser diagnodent: estudo comparativo com outras tecnicas de diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Godinho, Reugma Rego

    2002-07-01

    An evaluation of the Diagnodent equipment (Kavo Company, Germany) for the occlusal caries detection was dane through the comparison with other conventional diagnostic techniques, such as visual inspection, intra-oral micro camera and digital X-ray. The effectiveness of the equipment in the detection of hidden caries and its viability as a diagnosis method for caries in their initial stage was also studied. Fifty eight permanent molars and premolars teeth from patients with age between 6 and 30 years were studied. The obtained results indicated that the conventional methods employed for the caries diagnosis are unable to detect the carious lesion in its initial stage. The Diagnodent equipment has this capability to detect caries presenting a flawless surface, specially the hidden caries, allowing the dentist to decide between a preventive ar a conservative procedure. The main advantage of the Diagnodent is to be an objective method, compared to the visual and radiographic ones, that are dependent on the professional interpretation. The Diagnodent is, therefore, a promising alternative as an objective and standardized diagnosis method for the final diagnostic. (author)

  8. Clinical choice of prenatal diagnostic techniques%产前诊断实验技术的临床选择

    Institute of Scientific and Technical Information of China (English)

    吕时铭

    2015-01-01

    产前诊断技术对出生缺陷的控制至关重要。孕妇外周血生化标志检测的产前筛查、羊水脱落细胞、绒毛、脐血细胞的细胞遗传学分析等技术的成熟应用,荧光原位杂交、核酸体外扩增、基因测序、芯片等分子生物学技术的发展,使产前诊断水平得以大幅提高。高通量基因测序无创产前检测技术的应用迎来了产前诊断技术发展的新阶段。面对不断更新、日益增多的检测项目,需要客观地评估各项技术的优势与局限,才能科学地选择与组合各项技术进行产前诊断,充分发挥各技术在产前诊断中的作用。(中华检验医学杂志,2015,38:505-507)%Prenatal diagnosis is vitally important to control birth defects.The mature application of detecting biochemical markers in maternal serum and cytogenetic karyotype analysis of amniotic fluid cells , villi cells and umbilical cord blood cells , as well as the development of fluorescence in situ hybridization , nucleic acid amplification , gene sequencing , chips and other molecular biological techniques , have significantly improved the standards of prenatal diagnosis.The application of high-throughput sequencing , a non-invasive detection technique , ushers the development of prenatal diagnostic techniques into a new stage.In the face of a growing number of and constantly updated test items , it is necessary to assess the advantages and limitations of various prenatal diagnostic techniques , so as to realize scientific selection and combination, and utilize the techniques to their fullest potential.

  9. Infrastructure Security of the Ural Regions: Assessment Technique and Diagnostic Results

    Directory of Open Access Journals (Sweden)

    Pavel Arkadyevich Pykhov

    2015-09-01

    Full Text Available This article examines the infrastructure as one of the important elements of the economic system. Authors have considered the stages of formation of this concept in the scientific world, the ideas of a number of scientists on a role and place of infrastructure in the economic system are given. Short genesis of approaches to the description of infrastructure and to assignment of its functions to certain branches is created. The paper emphasized the importance of strengthening the infrastructural support to the transition of the economy to the machine mode of production. Two main methodological approaches describing the nature and content of infrastructure are allocated: branch-wise and functional. The author's technique of the assessment of infrastructure security of territories at the regional level is offered. A basis of this technique is the allocation of the set of special indicators which values allow to see the level of development of separate elements of infrastructure. Indicative analysis, which is the basis of the methods, allows to judge any phenomenon by comparing the current observed values with the previously accepted threshold levels. This comparison allows one to classify the observations on the scale of "norm-pre-crisis-crisis". The essential advantage of this method is the normalization of indicators, i.e. their reduction to one comparable conditional size. It allows to receive the assessment on certain blocks of indicators and a complex assessment on all set in general. Authors have allocated four basic elements of infrastructure, such as transport, communications and telecommunications, utilities and health care availability. In total, the technique includes 21 indicators. The results of approbatory calculations with the author's method have revealed shortcomings in the infrastructure development of the Ural region. The article is a brief analysis of the data with the accents on the individual indicators and areas.

  10. Spectral photothermal tissue diagnostics with step-scan FT-IR technique

    Science.gov (United States)

    Schüle, G.; Schmitz, B.; Steiner, R.

    1999-03-01

    Photothermal (PT) and Photoacoustic (PA) Step-Scan FT-IR measurements are successful tools for thickness determination of layered samples. Aiming to separate optically between different layered tissues, we have been able to distinguish skin, liver and muscle tissue by means of PT and PA measurement techniques. Performing Step-Scan FT-IR measurements, the PT and PA phase and amplitude signals follow the tissue's absorption peaks which corresponds to the absorption spectra. These results are supported and confirmed by a simulation using the Finite-Difference-Method (FDM) whereat the basic spectral data from absorption measurements and some assumed thermal properties of investigated tissues have been inserted.

  11. A fiber-optic diagnostic technique for mechanical detection of the laser-metal interaction underwater

    International Nuclear Information System (INIS)

    A new fiber-optic force sensor based on optical beam deflection for the investigation of the mechanical effects during laser-metal interaction underwater is developed. This sensor is applied to detect the laser-induced plasma ablation force and liquid-jet impact during the cavitation bubble collapse near a solid boundary when a Q-switched laser is focused on a metal in water. The experimental results indicate the liquid-jet effect outweighs the well-known laser-induced plasma ablation force. This technique has the advantages of high-frequency response, simple structure, and nondestructive examination

  12. New analysis methods to push the boundaries of diagnostic techniques in the environmental sciences

    Science.gov (United States)

    Lungaroni, M.; Murari, A.; Peluso, E.; Gelfusa, M.; Malizia, A.; Vega, J.; Talebzadeh, S.; Gaudio, P.

    2016-04-01

    In the last years, new and more sophisticated measurements have been at the basis of the major progress in various disciplines related to the environment, such as remote sensing and thermonuclear fusion. To maximize the effectiveness of the measurements, new data analysis techniques are required. First data processing tasks, such as filtering and fitting, are of primary importance, since they can have a strong influence on the rest of the analysis. Even if Support Vector Regression is a method devised and refined at the end of the 90s, a systematic comparison with more traditional non parametric regression methods has never been reported. In this paper, a series of systematic tests is described, which indicates how SVR is a very competitive method of non-parametric regression that can usefully complement and often outperform more consolidated approaches. The performance of Support Vector Regression as a method of filtering is investigated first, comparing it with the most popular alternative techniques. Then Support Vector Regression is applied to the problem of non-parametric regression to analyse Lidar surveys for the environments measurement of particulate matter due to wildfires. The proposed approach has given very positive results and provides new perspectives to the interpretation of the data.

  13. Diagnostic performance of MRI measurements to assess hindfoot malalignment. An assessment of four measurement techniques

    International Nuclear Information System (INIS)

    To investigate the ability of coronal non-weight-bearing MR images to discriminate between normal and abnormal hindfoot alignment. Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weight-bearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21-76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0 -10 valgus); (2) abnormal valgus (>10 ); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment. The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11 valgus. The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of <12 valgus. It is possible to suspect abnormal hindfoot alignment on coronal non-weight-bearing MR images. (orig.)

  14. Diagnostic performance of MRI measurements to assess hindfoot malalignment. An assessment of four measurement techniques

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Florian M.; Hoffmann, Adrienne; Mamisch-Saupe, Nadja; Hodler, Juerg [University Hospital Balgrist and University of Zurich, Radiology, Zuerich (Switzerland); Farshad, Mazda; Espinosa, Norman [University Hospital Balgrist and University of Zurich, Department of Orthopaedic Surgery, Zuerich (Switzerland); Resnick, Donald [University of California San Diego, Department of Radiology, San Diego, CA (United States)

    2013-09-15

    To investigate the ability of coronal non-weight-bearing MR images to discriminate between normal and abnormal hindfoot alignment. Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weight-bearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21-76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0 -10 valgus); (2) abnormal valgus (>10 ); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment. The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11 valgus. The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of <12 valgus. It is possible to suspect abnormal hindfoot alignment on coronal non-weight-bearing MR images. (orig.)

  15. Effects of anatomical position on esophageal transit time: A biomagnetic diagnostic technique

    Institute of Scientific and Technical Information of China (English)

    Teodoro Cordova-Fraga; Modesto Sosa; Cados Wiechers; Jose Maria De la Roca-Chiapas; Alejandro Maldonado Moreles; Jesus BernaI-Alvarado; Raquel Huerta-Franco

    2008-01-01

    AIM: To study the esophageal transit time (ETT)and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI).METHODS: A biomagnetic technique was implemented to perform this study: (1) The transit time of a magnetic marker (MM) through the esophagus was measured using two fluxgate sensors placed over the chest of 14 healthy subjects; (2) the ETT was assessed in three anatomical positions (at upright,fowler,and supine positions; 90°,45° and 0°,respectively).RESULTS: ANOVA and Tuckey post-hoc tests demonstrated significant differences between ETT mean of the different positions.The ETT means were 5.2 ±1.1 s,6.1±1.5 s,and 23.6 ± 9.2 s for 90°,45° and 0°,respectively.Pearson correlation results were r = -0.716 and P < 0.001 by subjects' anatomical position,and r =-0.024 and P > 0.05 according the subject's BHI.CONCLUSION: We demonstrated that using this biomagnetic technique,it is possible to measure the ETT and the effects of the anatomical position on the ETT.

  16. EFFICIENCY OF DIFFERENT TECHNIQUES FOR ANTIBODY DETERMINATION AND TESTING OF ANTIGEN-BINDING LYMPHOCYTES IN DIAGNOSTICS OF BRUCELLOSIS

    Directory of Open Access Journals (Sweden)

    B. V. Karalnik

    2014-07-01

    Full Text Available Abstract. The aim of this study was to compare the efficiency of different methods applied for the diagnostics of brucellosis. Huddlson and Wright reactions, RoseBengal test, ELISA-based test system (IgG determination, and a test for antigen-binding lymphocytes (ABL were used. There was shown that the specificity of tests was identical for either reactions based on detection of antibodies with commercial immune reagents and ELISA IgG. The sensitivity of ABL test is, however, superior to all the reactions based on antibody determination. The ABL test has advantages when compared with antibody detection techniques. This method permits early monitoring of brucellosis treatment/its efficiency since early terms, as well as differentiation between positive and false positive results of antibody determination in pregnant womеn.

  17. Comparison of computed tomography with radiography as a noninvasive diagnostic technique for chronic nasal disease in dogs

    International Nuclear Information System (INIS)

    Computed tomography was evaluated as a noninvasive technique for the diagnosis of chronic nasal disease in dogs. Computed tomographic images, radiographs, and histopathologic findings were compared in 11 dogs with chronic nasal disease. Definitive diagnosis was made following traumatic nasal flush, exploratory surgery, or necropsy. The study included 8 dogs with intranasal tumors, 2 dogs with bacterial rhinitis (Pasteurella sp), and 1 dog with mycotic rhinitis (Aspergillus sp). Computed tomography was superior to radiography in defining the extent of the disease process and in differentiating infectious rhinitis from nasal neoplasms. It defined lesions in the palate, nasopharyngeal meatus, maxillary sinus, caudal ethmoturbinates, and periorbital tissues that were difficult to demonstrate by use of conventional radiography. Tumors appeared as space-occupying lesions that obliterated the turbinates, caused deviation of the nasal septum, and eroded bone. Rhinitis appeared as a cavitating lesion that spared the paranasal sinuses, thickened and distorted the turbinates, and widened the meatus. Although morphologically distinct on computed tomographic images, infectious rhinitis and nasal neoplasms could not be differentiated by attenuation measurements or degree of contrast enhancement. Computed tomography appeared to be a reliable, noninvasive technique for the diagnosis of chronic nasal disease in dogs, and a promising alternative to diagnostic techniques currently in use

  18. DESIGN OF PIFA ANTENNA FOR MEDICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A.Umamakeswari

    2013-02-01

    Full Text Available The emerging techniques in the medical field include the use of bio implantable antennas to diagnose the diseases. The major disadvantage of these techniques is the side-effects caused by the radiations in the human body. There have been a lot of advancements in this area to reduce the radiation emitted. One among them is the use of PIFA antenna inside an indestructible capsule (Polyetheretherketones which is helpful in both short and long range communications. The workincludes the design of PIFA antenna using IE3D and MATLAB software. The characteristics of the antenna are analyzed with the aim to reduce the size and radiation effect of antenna and to increase thegain, efficiency and data rate.

  19. Diagnostic imaging of the breast. Examination techniques, appearances, differential diagnosis and interventiones. 3. compl. rev. ed.; Bildgebende Mammadiagnostik. Untersuchungstechnik, Befundmuster, Differenzialdiagnose und Interventionen

    Energy Technology Data Exchange (ETDEWEB)

    Heywang-Koebrunner, Sylvia H. [Referenzzentrum Mammographie, Muenchen (Germany).; Schreer, Ingrid [Radiologische Allianz, Hamburg (Germany).

    2015-07-01

    The book on diagnostic imaging of the breast covers the following topics: Part I: Techniques: anamnesis and dialogue, clinical indications, mammography, sonography, nuclear magnetic resonance imaging, new imaging techniques, image clarification and percutaneous breast biopsy, preoperative marking. Part II: Appearance: the normal mamma, benign mamma modifications, cysts, benign tumors, inflammatory diseases, lesions with uncertain biological potential (B3 lesions), in-situ carcinoma, invasive carcinoma. Lymph nodes, other semi-malign and malign tumors, post-traumatic, post-operative and post-therapeutic changes, imaging diagnostics for breast implants, skin changes, the male breast. Part III: Use of imaging breast diagnostics: continuative diagnostics of screening indications and problem solution for the symptomatic patient.

  20. A True Metasurface Antenna

    OpenAIRE

    Mohamed El Badawe; Almoneef, Thamer S.; Omar M. Ramahi

    2016-01-01

    We present a true metasurface antenna based on electrically-small resonators. The resonators are placed on a flat surface and connected to one feed point using corporate feed. Unlike conventional array antennas where the distance between adjacent antennas is half wavelength to reduce mutual coupling between adjacent antennas, here the distance between the radiating elements is electrically very small to affect good impedance matching of each resonator to its feed. A metasurface antenna measur...

  1. CT is a valid diagnostic technique in penetrating trauma to the back

    International Nuclear Information System (INIS)

    Clinical evaluation of penetrating back injury often misses injury. Laboratory data and standard radiography add little. A prospective study of the efficacy of CT in 214 patients with penetrating injuries to the back between the scapular tip and the iliac crest is reported. The treatment plan was determined by both CT and clinical findings. In 172 patients (80.4%), the CT findings were negative. Of these, 33 (15.4%) underwent exploratory surgery. Two had unidentified injury (diaphragmatic in two and hepatic in one). Eighteen CT scans (8.4%) were positive and were surgically confirmed. Seven additional injuries, including four to the diaphragm, were also found. Seventeen patients were followed up clinically and were excluded from the following statistics: sensitivity, 90%; specificity, 95%; accuracy, 95%. CT is therefore a valid technique for evaluation of penetrating injuries to the back

  2. A line-imaging velocity interferometer technique for shock diagnostics without x-ray preheat limitation.

    Science.gov (United States)

    Wang, Feng; Peng, Xiaoshi; Liu, Shenye; Xu, Tao; Mei, Lusheng; Jiang, Xiaohua; Ding, Yongkun

    2011-10-01

    A study was conducted with a line-imaging velocity interferometer on sandwich targets at the Shen Guang-III prototype laser facility in China, with the goal of eliminating the preheat effect. A sandwich target structure was used to reduce the x-ray preheat limitation (radiation temperature ~170 eV) in a radiative drive shock experiment. With a thick ablator, the preheat effect appeared before the shock arrived at the window. After adding a shield layer of high-Z material on the ablator, x-rays which penetrated the ablator were so weak that the blank-out effect could not be measured. This experiment indicates that the sandwich target may provide a valuable technique in experiments such as equation of state and shock timing for inertial confinement fusion studies. PMID:22047281

  3. Diagnostic radiography in orthopedics. Focusing techniques; 3. new rev. ed.; Orthopaedische Roentgendiagnostik. Einstelltechnik

    Energy Technology Data Exchange (ETDEWEB)

    Bernau, A.

    1995-12-31

    After the introductory chapters dealing inter alia with approaches to defining the imaging tasks in relation to the anatomical regions to be exposed, and the relevant positioning, or aspects of radiological protection, positioning aids, and image optimization, the textbook presents a comprehensive guide to good imaging based on the functional approach commonly used in orthopedics, showing and explaining standard radiographs of the skeleton. The main aspect in this richly illustrated key part of the book is the focusing techniques best suitable for imaging the skull, the spine, the thorax and shoulders, the upper limbs, the pelvic region, and the lower limbs. (MG). 577 figs. [Deutsch] Nach einleitenden Kapiteln, die sich u.a. mit der anatomischen Orientierung, Strahlenschutzaspekten, Lagerungshilfen und Bildoptimierung befassen, wird eine der funktionellen Betrachtungsweise in der Orthopaedie angepasste Normierung der Skelettaufnahmen versucht. Dieser sich mit der Einstelltechnik befassende Hauptteil gliedert sich in die Bereiche Schaedel, Wirbelsaeule, Brustkorb und Schulterguertel, obere Extremitaeten, Beckenguertel sowie untere Extremitaeten. (MG)

  4. Plasma optical emission spectroscopy diagnostic during amorphous silicon thin films deposition by Rf sputtering technique

    International Nuclear Information System (INIS)

    This paper deals with the study of the glow discharge, used for amorphous silicon thin films deposition by Rf sputtering technique. The produced plasma is investigated by mean of the optical emission spectroscopy (OES) analysis. Different plasmas obtained with changing the gas pressure and Rf powers were analysed at different positions in the inter-electrode space. Emission lines from Ar, Si, Si+ and Ar+ were observed in the visible region. It was found that emission intensities of all the observed lines have a spatial Gaussian shape. The maximum intensity is located in the core of the plasma and decrease in the electrodes region. The ratio between the Si and Ar+ intensities (ISi/IAr+), in the target region, is proposed as a new tool to estimate the Ar sputtering yield. This ratio was compared to the theoretical calculated sputtering yield. The difference between these two quantities is exploited to determine the contribution of fast Ar neutrals in the sputtering process.

  5. Research on the Scattering Characteristics and the RCS Reduction of Circularly Polarized Microstrip Antenna

    OpenAIRE

    Jiang, W.; Hong, T.; S. X. Gong

    2013-01-01

    Based on the study of the radiation and scattering of the circularly polarized (CP) antenna, a novel radar cross-section (RCS) reduction technique is proposed for CP antenna in this paper. Quasi-fractal slots are applied in the design of the antenna ground plane to reduce the RCS of the CP antenna. Both prototype antenna and array are designed, and their time-, frequency-, and space-domain characteristics are studied to authenticate the proposed technique. The simulated and measured results s...

  6. A COMPACT CIRCULARLY POLARIZED SLOTTED MICROSTRIP ANTENNA

    Directory of Open Access Journals (Sweden)

    V. Jebaraj

    2014-12-01

    Full Text Available Slot antennas are often used at UHF and microwave frequencies. In slot antenna for RFID reader applications the frequency ranges from 902-923MHz to achieve circular polarization. The shapes and size of the slot, as well as the driving frequency, determine the radiation distribution pattern. The proposed compact size circularly polarized slotted microstrip antenna are summarized with design rules. The circularly polarized radiation in square patch antenna can be obtained by perturbation technique with different shapes of slot in the orthogonal direction. A single feed configuration based symmetric slotted microstrip antenna is adapted to realize the compact circularly polarized microstrip antennas. Based on the perimeter, the size of the slot on microstrip slot antenna are studied and compared. The Operating frequency of the antenna is 912MHz that can be tuned by varying the perimeter of the slot while the keeping the circularly polarized radiation unchanged. The schematic and layout are configured by using Advanced Design System (ADS. Return loss, Resonant Frequency, Axial Ratio (AR, and Gain were determined for the proposed system using ADS. A measured 3dB Axial Ratio (AR bandwidth around 6MHz with 16MHz impedance bandwidth has been achieved for the antenna on a RO3004C substrate with dielectric constant 3.38.

  7. Cardiovascular magnetic resonance of myocardial edema using a short inversion time inversion recovery (STIR) black-blood technique:Diagnostic accuracy of visual and semi-quantitative assessment

    OpenAIRE

    h-Ici Darach O; Ridgway John P; Kuehne Titus; Berger Felix; Plein Sven; Sivananthan Mohan; Messroghli Daniel R

    2012-01-01

    Abstract Background The short inversion time inversion recovery (STIR) black-blood technique has been used to visualize myocardial edema, and thus to differentiate acute from chronic myocardial lesions. However, some cardiovascular magnetic resonance (CMR) groups have reported variable image quality, and hence the diagnostic value of STIR in routine clinical practice has been put into question. The aim of our study was to analyze image quality and diagnostic performance of STIR using a set of...

  8. Sentinel lymph node diagnostic in prostate carcinoma: Part I. Technique and clinical evaluation

    International Nuclear Information System (INIS)

    Aim: Evaluation of the significance of lymphoscintigraphy and intraoperative probe measurement for the identification of the sentinel lymph node (SLN) in prostate cancer. Patients and method: In 117 patients with prostate cancer scintigrams in various projections were acquired till approximately 6 hours p.i. after ultrasound guided transrectal intraprostatic injection of 99mTc-Nanocoll trademark. On the following day the SLNs were identified in the operation theatre with a gamma probe and removed. Pelvic standard lymph node dissection followed SLNE. Results: In three of 117 patients with preoperative lymphoscintigraphy no SLN was scintigraphically detectable. These three patients had antecedent transurethral resection of the prostate. In 113 of the residual 114 patients SLN could be intraoperatively localized. In the mean four SLNs per patient were removed. 28 of 117 patients had pelvic lymph node metastases. In 25 cases SLN were right-positive, in one false-negative and in one intraoperatively not detectable. In one patient we found macrometastasis of up to 4 cm diameter (one SLN was tumour positive). In 15 cases only the SLN was bearing tumour. Conclusion: The SLNE with preoperative lymphoscintigraphy and intraoperative gamma probe measurement is suitable for detecting lymph node metastasis in prostate cancer. SLNE is superior to the surgical techniques commonly used in pelvic lymphadenectomy. (orig.)

  9. Foetal radiography for suspected skeletal dysplasia: technique, normal appearances, diagnostic approach

    Energy Technology Data Exchange (ETDEWEB)

    Calder, Alistair D. [Great Ormond Street Hospital for Children NHS Foundation Trust, Radiology Department, London (United Kingdom); Offiah, Amaka C. [Sheffield Children' s NHS Foundation Trust, Academic Unit of Child Health, Sheffield (United Kingdom)

    2015-04-01

    Despite advances in antenatal imaging and genetic techniques, post-delivery post-mortem foetal radiography remains the key investigation in accurate diagnosis of skeletal dysplasia manifesting in the foetus. Foetal radiography is best performed using pathology-specimen radiography equipment and is often carried out in the pathology department without involvement of the radiology unit. However, paediatric radiologists may be asked to interpret post-mortem foetal radiographs when an abnormality is suspected. Many foetal radiographs are carried out before 20 weeks' gestation, and the interpreting radiologist needs to be familiar with the range of normal post-mortem foetal appearances at different gestational ages, as well as the appearances of some of the more commonly presenting skeletal dysplasias, and will benefit from a systematic approach when assessing more challenging cases. In this pictorial essay, we illustrate various normal post-mortem foetal radiographic appearances, give examples of commonly occurring skeletal dysplasias, and describe an approach to establishing more difficult diagnoses. (orig.)

  10. Plasma antennas: dynamically configurable antennas for communications

    International Nuclear Information System (INIS)

    In recent years, the rapid growth in both communications and radar systems has led to a concomitant growth in the possible applications and requirements of antennas. These new requirements include compactness and conformality, rapid reconfigurability for directionality and frequency agility. For military applications, antennas should also allow low absolute or out-of-band radar cross-section and facilitate low probability of intercept communications. Investigations have recently begun worldwide on the use of ionised gases or plasmas as the conducting medium in antennas that could satisfy these requirements. Such plasma antennas may even offer a viable alternative to metal in existing applications when overall technical requirements are considered. A recent patent for ground penetrating radar claims the invention of a plasma antenna for the transmission of pulses shorter than 100 ns in which it is claimed that current ringing is avoided and signal processing simplified compared with a metal antenna. A recent US ONR tender has been issued for the design and construction of a compact and rapidly reconfigurable antenna for dynamic signal reception over the frequency range 1 - 45 GHz based on plasma antennas. Recent basic physics experiments at ANU have demonstrated that plasma antennas can attain adequate efficiency, predictable radiation patterns and low base-band noise for HF and VHF communications. In this paper we describe the theory of the low frequency plasma antenna and present a few experimental results

  11. The Positron Emission Tomography. A diagnostic technique; Con la PET diagnosi precoce della malattia

    Energy Technology Data Exchange (ETDEWEB)

    Salvadori, P. [Consiglio Nazionale delle Ricerche, Istituto di Fisiologia Clinica, Chimica e Radiofarmaceutica, Gruppo PET/Ciclotrone, Pisa (Italy)

    2001-07-01

    Positron Emission Tomography (PET) is a new imaging modality, which is able to assess non-invasively the biochemical mechanisms, underlying physiological and pathophysiological processes in vivo in humans. The technique relies on the administration of radioactive tracers labeled with short-lived positron emitters, which need to be produced on site via a particle accelerator (cyclotron). Radionuclides are produced upon request and formulated into biologically active organic molecules having precise pharmacokinetics and specificity. The radiotracer can be detected by the PET scanner and represented as tomographic sections (images of body sections) showing its regional distribution and concentration. This makes it possible to address clinical questions concerning occurrence and evolution of many diseases as well as their response to therapy. The ability to image (measure) biological processes and not only anatomy enables PET to explore diseases in the very early stage, including those diseases which are not related to modifications of organ structure (e.g. psychiatric diseases, metabolic disorders, biochemical disfunction). PET plays a major role, in conjunction with the other imaging modalities, to improve diagnosis capabilities and disease mechanism understanding. [Italian] La PET e' correntemente utilizzata come efficace strumento clinico, per l'elevata sensibilita' e specificita', nella valutazione dell'iter diagnostico di pazienti con sospetta cardiopatia ischemica e nel processo di decision making clinico di pazienti con disfunzione ventricolare sinistra e cardiopatia ischemica, in quanto metodica di riferimento per la diagnosi di vitalita' miocardica. In campo oncologico, viene impiegata l'ormai ben documentata capacita' del fluorodesossiglucosio (FDG), un tracciante contenente fluoro-18 ed in grado di permettere la misura del consumo cellulare di glucosio, nel porre in evidenza all'esame PET il tessuto neoplastico

  12. Ultra-Wide-Band Microstrip Concentric Annular Ring Antenna for Wireless Communications

    Directory of Open Access Journals (Sweden)

    Salima Azzaz-Rahmani

    2012-01-01

    Full Text Available In this paper, a new design technique for bandwidth enhancement of concentric microstrip annular ring slot antennas is presented. Using this technique, an Ultra-Wide-Band antenna is designed with simulated bandwidth of 111.29%.

  13. Innovation in wearable and flexible antennas

    CERN Document Server

    Khaleel, Haider

    2014-01-01

    This book deals with the design, numerical simulation, state of the art fabrication processes and methods, qualitative and quantitative tests, and measurement techniques of wearable and flexible antennas of different topologies, such as: Planar Inverted F, Printed Monopoles, Micropoles and Microstrips. Novel trends, materials, and fabrication and measurement techniques used in this vital field of antenna systems are also discussed.To the best of the editor's knowledge, at the time of publication, there are no published books targeting the vital topic of flexible antennas specifically and/or se

  14. Design and analysis of coupled-resonator reconfigurable antenna

    Science.gov (United States)

    Hossain, M. I.; Faruque, M. R. I.; Islam, M. T.; Ali, M. T.

    2016-01-01

    In this paper, a coupled resonator with the microstrip patch antenna is proposed as a frequency reconfigurable antenna. The ground plane of the proposed microstrip patch antenna is modified with the proposed resonator structure to obtain reconfigurable characteristics. The resonator structure consists of two square split rings. The incorporation of proposed resonator structure with antenna makes it single-band antenna. The characteristics of proposed resonator structure can effectively deactivate by closing the splits of rings using switches, and hence, the dual-band characteristics of the antenna are recovered. The finite integration technique of computer simulation technology microwave studio is used throughout the investigation. The measurement of antenna performances is taken in an anechoic chamber. The measured and simulated performances of proposed reconfigurable antenna show very good agreement.

  15. The problem of sexual imbalance and techniques of the self in the Diagnostic and Statistical Manual of Mental Disorders.

    Science.gov (United States)

    Flore, Jacinthe

    2016-09-01

    This article examines the problematization of sexual appetite and its imbalances in the development of the Diagnostic and Statistical Manual of Mental Disorders (DSM) in the twentieth and twenty-first centuries. The dominant strands of historiographies of sexuality have focused on historicizing sexual object choice and understanding the emergence of sexual identities. This article emphasizes the need to contextualize these histories within a broader frame of historical interest in the problematization of sexual appetite. The first part highlights how sexual object choice, as a paradigm of sexual dysfunctions, progressively receded from medical interest in the twentieth century as the clinical gaze turned to the problem of sexual appetite and its imbalances. The second part uses the example of the newly introduced Female Sexual Interest/Arousal Disorder in the DSM-5 to explore how the Manual functions as a technique for taking care of the self. I argue that the design of the Manual and associated inventories and questionnaires paved the way for their interpretation and application as techniques for self-examination. PMID:27118809

  16. Miniaturized Planar Split-Ring Resonator Antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2009-01-01

    A miniaturized planar antenna based on a broadside-coupled split ring resonator excited by an arc-shaped dipole is presented. The excitation dipole acts as a small tuning capacitor in series with a parallel RLC circuit represented by the SRR. The antenna resonance frequency and dimensions a...... essentially determined by the SRR, while by varying the dipole arm length the input resistance is changed in a wide range, thus matching the antenna to a feed line and compensating for simulation and manufacturing inaccuracies. No additional matching network is required. Theoretically, there is no limit on...... subsequently tuned to 50 ohms simply by cutting out the excessive arm length. This tuning technique is especially useful in practical applications, since it allows the antenna to be tuned in-place and thereby compensate for various inaccuracies as well as for an antenna environment....

  17. Evolutionary Optimization of Yagi-Uda Antennas

    Science.gov (United States)

    Lohn, Jason D.; Kraus, William F.; Linden, Derek S.; Colombano, Silvano P.

    2001-01-01

    Yagi-Uda antennas are known to be difficult to design and optimize due to their sensitivity at high gain, and the inclusion of numerous parasitic elements. We present a genetic algorithm-based automated antenna optimization system that uses a fixed Yagi-Uda topology and a byte-encoded antenna representation. The fitness calculation allows the implicit relationship between power gain and sidelobe/backlobe loss to emerge naturally, a technique that is less complex than previous approaches. The genetic operators used are also simpler. Our results include Yagi-Uda antennas that have excellent bandwidth and gain properties with very good impedance characteristics. Results exceeded previous Yagi-Uda antennas produced via evolutionary algorithms by at least 7.8% in mainlobe gain. We also present encouraging preliminary results where a coevolutionary genetic algorithm is used.

  18. In-cylinder pressure-based direct techniques and time frequency analysis for combustion diagnostics in IC engines

    International Nuclear Information System (INIS)

    Highlights: • Direct pressure-based techniques have been applied successfully to spark-ignition engines. • The burned mass fraction of pressure-based techniques has been compared with that of 2- and 3-zone combustion models. • The time frequency analysis has been employed to simulate complex diesel combustion events. - Abstract: In-cylinder pressure measurement and analysis has historically been a key tool for off-line combustion diagnosis in internal combustion engines, but online applications for real-time condition monitoring and combustion management have recently become popular. The present investigation presents and compares different low computing-cost in-cylinder pressure based methods for the analyses of the main features of combustion, that is, the start of combustion, the end of combustion and the crankshaft angle that responds to half of the overall burned mass. The instantaneous pressure in the combustion chamber has been used as an input datum for the described analytical procedures and it has been measured by means of a standard piezoelectric transducer. Traditional pressure-based techniques have been shown to be able to predict the burned mass fraction time history more accurately in spark ignition engines than in diesel engines. The most suitable pressure-based techniques for both spark ignition and compression ignition engines have been chosen on the basis of the available experimental data. Time–frequency analysis has also been applied to the analysis of diesel combustion, which is richer in events than spark ignited combustion. Time frequency algorithms for the calculation of the mean instantaneous frequency are computationally efficient, allow the main events of the diesel combustion to be identified and provide the greatest benefits in the presence of multiple injection events. These algorithms can be optimized and applied to onboard diagnostics tools designed for real control, but can also be used as an advanced validation tool for

  19. Investigation of microwave antennas with improved performances

    Science.gov (United States)

    Zhou, Rongguo

    This dissertation presents the investigation of antennas with improved performances at microwave frequencies. It covers the following three topics: the study of the metamaterial with near-zero index of refraction and its application in directive antenna design, the design technique of a wideband circularly polarized patch antenna for 60GHz wireless application and the investigation of a novel direction of arrival (DOA) estimation technique inspired by human auditory system. First, the metamaterial composed of two-dimensional (2-D) metallic wire arrays is investigated as an effective medium with an effective index of refraction less than unity (neff effective medium parameters (permittivity epsilon eff, permeability mueff and neff ) of a wire array are extracted from the finite-element simulated scattering parameters and verified through a 2-D electromagnetic band gap (EBG) structure case study. A simple design methodology for directive monopole antennas is introduced by embedding a monopole within a metallic wire array with neff effect of the monopole antenna is demonstrated in both simulation and experiment at X-band (8 -- 12 GHz). The measured antenna properties including return loss and radiation patterns are in good agreement with simulation results. Parametric studies of the antenna system are performed. The physical principles and interpretations of the directive monopole antenna embedded in the wire array medium are also discussed. Second, a fully packaged wideband circularly polarized patch antenna is designed for 60GHz wireless communication. The patch antenna incorporates a diagonal slot at the center and features a superstrate and an air cavity backing to achieve desired performances including wide bandwidth, high efficiency and low axial ratio. The detailed design procedure of the circularly polarized antenna, including the design of the microstrip-fed patch antenna and the comparison of the performances of the antenna with different feeding interfaces

  20. Cut Slotted Microstrip Antenna for Dual Frequency Application and Analysis Using Different Optimizer Available In Ie3d

    OpenAIRE

    Hasanujjaman,; Mehedi Hasan Habib Mondal

    2014-01-01

    Design of dual frequency antenna always gives the added advantages for microwave antenna applications. In this paper Fast EM and Powel method based design of a dual-frequency patch antenna using IE3D is presented. The proposed antenna is excited through the inset feed technique and the antenna design and parametric studies has been executed. The method effectively obtains the geometric parameters for efficient antenna performance. Maximum return loss obtained at 7 GHz is -36.5...

  1. An expert diagnostic system based on neural networks and image analysis techniques in the field of automated cytogenetics.

    Science.gov (United States)

    Beksaç, M S; Eskiizmirliler, S; Cakar, A N; Erkmen, A M; Dağdeviren, A; Lundsteen, C

    1996-03-01

    In this study, we introduce an expert system for intelligent chromosome recognition and classification based on artificial neural networks (ANN) and features obtained by automated image analysis techniques. A microscope equipped with a CCTV camera, integrated with an IBM-PC compatible computer environment including a frame grabber, is used for image data acquisition. Features of the chromosomes are obtained directly from the digital chromosome images. Two new algorithms for automated object detection and object skeletonizing constitute the basis of the feature extraction phase which constructs the components of the input vector to the ANN part of the system. This first version of our intelligent diagnostic system uses a trained unsupervised neural network structure and an original rule-based classification algorithm to find a karyotyped form of randomly distributed chromosomes over a complete metaphase. We investigate the effects of network parameters on the classification performance and discuss the adaptability and flexibility of the neural system in order to reach a structure giving an output including information about both structural and numerical abnormalities. Moreover, the classification performances of neural and rule-based system are compared for each class of chromosome. PMID:8705397

  2. Comparison of four diagnostic techniques for detection of Trichomonas vaginalis infection in females attending tertiary care hospital of North India

    Directory of Open Access Journals (Sweden)

    Razia Khatoon

    2015-01-01

    Full Text Available Background: Trichomonas vaginalis causes a common sexually transmitted disease trichomoniasis, which may lead to increased risk of transmission of human immunodeficiency virus infection and other pelvic inflammatory diseases. Wet mount examination is the most common test for diagnosis, but it has low sensitivity. Acridine orange staining can be used for diagnosis, but it requires special microscopic facility. Culture is considered as the gold standard, but it takes a long time for diagnosis. OSOM Trichomonas Rapid Test is a recently introduced rapid method based on immunochromatographic assay of trichomonal protein antigens. Hence, the present study was done to compare these four diagnostic techniques for detection of trichomoniasis in females with vaginal discharge. Materials and Methods: Vaginal swabs were taken from 835 female patients and wet mount examination, acridine orange staining, culture in Kupferberg medium, and OSOM Trichomonas Rapid Test, were performed. Results: Out of 835 patients included in our study, 68 (8.1% positive cases of trichomoniasis were detected by culture. OSOM Trichomonas Rapid Test detected 63 (7.5% cases, acridine orange staining detected 53 (6.3% cases, whereas, wet mount examination detected only 45 (5.4% positive cases. OSOM Trichomonas Rapid Test performed well and showed high sensitivity and specificity of 88.2% and 99.6%, respectively. Conclusion: As OSOM Trichomonas Rapid Test is a point of care test and gave better results than both wet mount examination and acridine orange staining; it can be used as a routine test in peripheral areas lacking laboratory facilities.

  3. The spherical helical antenna

    OpenAIRE

    Cardoso, J. Christopher

    1992-01-01

    The spherical helical antenna is investigated as a new variation of the conventional helical antenna. The spherical helix is a wire antenna in a helix shape that is wound over a spherical surface instead of the standard cylindrical one. Analysis of this structure requires numerical methods and experimental measurements because its complex geometry makes it very difficult to develop analytic expressions for its radiation characteristics. The wire antenna code ESP, based on the method of ...

  4. Space-Frame Antenna

    Science.gov (United States)

    Curtis, Steven A.

    2010-01-01

    The space-frame antenna is a conceptual antenna structure that would be lightweight, deployable from compact stowage, and capable of deforming itself to a size, shape, and orientation required for a specific use. The space-frame antenna would be a trusslike structure consisting mostly of a tetrahedral mesh of nodes connected by variable-length struts. The deformation of the antenna to a desired size, shape, and orientation would be effected through coordinated lengthening and shorting of the struts.

  5. Wide Coverage Antennas

    OpenAIRE

    Zackrisson, Jan

    2007-01-01

    Small satellites require small and lightweight antennas for telemetry and command function as well as for downlinking of data. We have during the last thirty years developed a large suite of wide coverage antennas. The basic radiator designs used are quadrifilar helices, waveguides, horns and patch excited cups (PEC) depending on frequency range, coverage requirements and application. The antenna designs range from L-band up to Ka-band frequencies. Typical coverages for the antennas are from ...

  6. Aneurysmal bone cyst: revision of different techniques in imaging diagnostic. Quiste oseo aneurismatico: revision de diferentes tecnicas de diagnostico por la imagen

    Energy Technology Data Exchange (ETDEWEB)

    Parra Blanco, J.A.; Fernandez Echevarria, M.A.; Pagola Serrano, M.A.; Vara Vara, A.; Gonzalez Tutor, A. (Hospital Universitario ' ' Marques de Valdecilla' ' . Servicio de Radiodiagnostico. Santander (Spain))

    1993-05-01

    We study simple radiology, conventional tomography, computed tomography and angiography in 8 cases of aneurysmal bone cyst for the purpose of assessing the utility of these diagnostic techniques. Our results, in agreement with those in the literature, indicate that the presence of a generally well-defined lytic, insufflated lesion containing septi should suggest this disorder. (Author)

  7. Field and laboratory comparative evaluation of rapid malaria diagnostic tests versus traditional and molecular techniques in India

    Directory of Open Access Journals (Sweden)

    Bharti Praveen K

    2010-07-01

    Full Text Available Abstract Background Malaria presents a diagnostic challenge in most tropical countries. Microscopy remains the gold standard for diagnosing malaria infections in clinical practice and research. However, microscopy is labour intensive, requires significant skills and time, which causes therapeutic delays. The objective of obtaining result quickly from the examination of blood samples from patients with suspected malaria is now made possible with the introduction of rapid malaria diagnostic tests (RDTs. Several RDTs are available, which are fast, reliable and simple to use and can detect Plasmodium falciparum and non-falciparum infections or both. A study was conducted in tribal areas of central India to measure the overall performance of several RDTs for diagnosis of P. falciparum and non-falciparum infections in comparison with traditional and molecular techniques. Such data will be used to guide procurement decisions of policy makers and programme managers. Methods Five commercially available RDTs were tested simultaneously in field in parallel with peripheral blood smears in outbreak-affected areas. The evaluation is designed to provide comparative data on the performance of each RDT. In addition, molecular method i.e. polymerase chain reaction (PCR was also carried out to compare all three methods. Results A total of 372 patients with a clinical suspicion of malaria from Bajag Primary Health Centre (PHC of district Dindori and Satanwada PHC of district Shivpuri attending the field clinics of Regional Medical Research Centre were included in the study. The analysis revealed that the First Response Malaria Antigen pLDH/HRP2 combo test was 94.7% sensitive (95% CI 89.5-97.7 and 69.9% specific (95% CI 63.6-75.6 for P. falciparum. However, for non-falciparum infections (Plasmodium vivax the test was 84.2% sensitive (95% CI 72.1-92.5 and 96.5% specific (95% CI 93.8-98.2. The Parascreen represented a good alternative. All other RDTs were relatively

  8. Experimental demonstration of superdirective dielectric antenna

    Energy Technology Data Exchange (ETDEWEB)

    Krasnok, Alexander E.; Filonov, Dmitry S.; Belov, Pavel A. [National Research University of Information Technologies, Mechanics and Optics (ITMO), St. Petersburg 197101 (Russian Federation); Simovski, Constantin R. [National Research University of Information Technologies, Mechanics and Optics (ITMO), St. Petersburg 197101 (Russian Federation); Aalto University, School of Electric and Electronic Engineering, Aalto FI76000 (Finland); Kivshar, Yuri S. [National Research University of Information Technologies, Mechanics and Optics (ITMO), St. Petersburg 197101 (Russian Federation); Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2014-03-31

    We propose and demonstrate experimentally a simple approach for achieving superdirectivity of emitted radiation for electrically small antennas based on a spherical dielectric resonator with a notch excited by a dipole source. Superdirectivity is achieved without using complex antenna arrays and for a wide range of frequencies. We also demonstrate the steering effect for a subwavelength displacement of the source. Finally, unlike previously known superdirective antennas, our design has significantly smaller losses, at the operation frequency radiation efficiency attains 80%, and matching holds in the 3%-wide frequency band without any special matching technique.

  9. Planar Tri-Band Antenna Design

    Directory of Open Access Journals (Sweden)

    M. Pokorny

    2008-04-01

    Full Text Available The paper briefly uncovers techniques used for a design of compact planar antennas in order to achieve the wideband and the multi-band capability. The main topic is aimed to the multi-objective optimization using genetic algorithms. A quarter-wavelength planar inverted-F antenna (PIFA using a slot and shorted parasitic patches is chosen to cover GSM900, GSM1800 and ISM2400 bands. A global multi-objective optimization uses a binary genetic algorithm with a composite objective function to tune this antenna. The impedance match and the direction of maximum gain are desired parameters to improve.

  10. A directional antenna for borehole radar

    International Nuclear Information System (INIS)

    The borehole radar system developed during phase II of the International Stripa Project has been successfully applied to mapping fracture zones up to 100 meters from the borehole in granite. The techniques previously used to determine the orientation of fracture zones (single hole reflection, crosshole reflection, crosshole tomography) have been supplemented with a directional antenna, which makes it possible to determine the orientation from measurements in a single borehole. The antenna works by synthesizing four signals to produce directional information. Tests performed in Stripa show that the resolution of the antenna is about 50

  11. Wideband Reconfigurable Rolled Planar Monopole Antenna

    OpenAIRE

    Ruvio, Giuseppe; Ammann, Max

    2007-01-01

    A novel technique to reconfigure the frequency range of a planar monopole antenna is presented. By adjusting the degree of spiral tightness, a shift of the well-matched operating frequency range is achieved. The proposed antenna is capable of covering the frequencies in the range from 2.9 to 15 GHz, depending on the degree of spiral tightness. The antenna yields a high-efficiency across the full operating bandwidth. Radiation patterns show good omni-directional features in all primary cuts an...

  12. Antenna development for high field plasma imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kong, X.; Domier, C. W.; Luhmann, N. C. Jr. [Department of Applied Science, University of California at Davis, Davis, California 95616 (United States)

    2010-10-15

    Electron cyclotron emission imaging (ECEI) and microwave imaging reflectometry (MIR) are two microwave nonperturbing plasma visualization techniques that employ millimeter-wave imaging arrays with lens-coupled planar antennas, yielding time-resolved images of temperature (via ECEI) and electron density (via MIR) fluctuations within high temperature magnetic fusion plasmas. A series of new planar antennas have been developed that extend this technology to frequencies as high as 220 GHz for use on high field plasma devices with toroidal fields in excess of 3 T. Antenna designs are presented together with theoretical calculations, simulations, and experimental measurements.

  13. The mathematical model of antenna and antenna-radome system

    OpenAIRE

    Knyazeva, L. V.; Artishev, A. I.

    2003-01-01

    Methods, algorithms and programs for calculation by computer of the characteristics of the antenna and the antenna-radome system (ARS) are developed. The type of antenna considered is the phased antenna array (PAA) or the cophase antenna with a mechanical beam control (an antenna array - AA). Radome shape is spherical, quasi-conic or flattened ellipsoid. Radome shell is multilayer ( N≥1), same-thickness, or special profile. Errors in the manufacture of the antenna are taken into account. Prog...

  14. Compact, Frequency Reconfigurable, Printed Monopole Antenna

    Directory of Open Access Journals (Sweden)

    Ricardo Gonçalves

    2012-01-01

    Full Text Available This paper proposes a possible implementation of a compact printed monopole antenna, useful to operate in UMTS and WLAN bands. In order to accomplish that, a miniaturization technique based on the application of chip inductors is used in conjunction with frequency reconfiguration capability. The chip inductors change the impedance response of the monopole, allowing to reduce the resonant frequency. In order to be able to operate the antenna in these two different frequencies, an antenna reconfiguration technique based on PIN diodes is applied. This procedure allows the change of the active form of the antenna leading to a shift in the resonant frequency. The prototype measurements show good agreement with the simulation results.

  15. Evolutionary Optimization of a Quadrifilar Helical Antenna

    Science.gov (United States)

    Lohn, Jason D.; Kraus, William F.; Linden, Derek S.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    Automated antenna synthesis via evolutionary design has recently garnered much attention in the research literature. Evolutionary algorithms show promise because, among search algorithms, they are able to effectively search large, unknown design spaces. NASA's Mars Odyssey spacecraft is due to reach final Martian orbit insertion in January, 2002. Onboard the spacecraft is a quadrifilar helical antenna that provides telecommunications in the UHF band with landed assets, such as robotic rovers. Each helix is driven by the same signal which is phase-delayed in 90 deg increments. A small ground plane is provided at the base. It is designed to operate in the frequency band of 400-438 MHz. Based on encouraging previous results in automated antenna design using evolutionary search, we wanted to see whether such techniques could improve upon Mars Odyssey antenna design. Specifically, a co-evolutionary genetic algorithm is applied to optimize the gain and size of the quadrifilar helical antenna. The optimization was performed in-situ in the presence of a neighboring spacecraft structure. On the spacecraft, a large aluminum fuel tank is adjacent to the antenna. Since this fuel tank can dramatically affect the antenna's performance, we leave it to the evolutionary process to see if it can exploit the fuel tank's properties advantageously. Optimizing in the presence of surrounding structures would be quite difficult for human antenna designers, and thus the actual antenna was designed for free space (with a small ground plane). In fact, when flying on the spacecraft, surrounding structures that are moveable (e.g., solar panels) may be moved during the mission in order to improve the antenna's performance.

  16. Pitfalls in the application of antigen immunoassays: Monitoring of trypanosoma vivax infection in two goats using direct and indirect diagnostic techniques

    International Nuclear Information System (INIS)

    Monoclonal antibodies (MAbs) directed against intracytoplasmic antigens from Trypanosoma vivax, T. congolense and T. brucei bloodstream forms released following cell destruction were developed and incorporated into a sandwich enzyme lined immunosorbent assay (ELISA). As supported by the Joint FAO/IAEA Animal Production and Health Subprogramme, the ELISA technology was transferred to National Agricultural Research Systems (NARS) in Africa and used in combination with standard parasitological techniques for monitoring tsetse and bovine trypanosomosis control programmes. Referring to the results of the assay field evaluation from 15 African countries, the FAO/IAEA direct antigen sandwich ELISA had a diagnostic specificity in the range of 94-100% using a cut-off value of 10% positivity when applied to negative cattle populations in tsetse free areas. In comparison with other diagnostic techniques, the results from positive cattle populations in tsetse infected areas demonstrated that the ELISA had greater diagnostic sensitivity than parasitological techniques in the detection of T. brucei, but had less in the detection of T. congolense and T. vivax. However, the diagnostic sensitivity of the ELISA varied enormously between animals

  17. Two Types of Compact UHF Antennas for Partial Discharge Measurement

    Institute of Scientific and Technical Information of China (English)

    JIN Zhuo-rui; SUN Cai-xin; CHENG Chang-kui; LI Jian

    2008-01-01

    To investigate the partial discharge (PD) online monitoring of transformers by ultra-high-frequency (UHF) approaches, high-qualified UHF antennas are focused on as one key technique. The size of UHF sensor used for PD UHF online monitoring in transformer is excessively large, therefore, it is not convenient for internal installation of transformer. Two types of compact UHF antennas with small sizes, a Hilbert fractal antenna and a small loop antenna are presented. PD experiments of three typically artificial insulation defects are executed and both antennas are used for PD measurement. The spectra of power via frequency of detected PD signals are analyzed and compared. The experimental results show that the Hilbert fractal antenna and small loop antenna are qualified for PD online UHF monitoring.

  18. Multiple Antenna Systems with Inherently Decoupled Radiators

    DEFF Research Database (Denmark)

    Pelosi, Mauro; Knudsen, Mikael B.; Pedersen, Gert Frølund

    2012-01-01

    In multiple antenna systems mutual coupling needs to be minimized. We propose an alternative novel decoupling technique, investigating several multiple antenna configurations for small handsets through measurements and numerical simulations. The influence of different novel designs on performance...... inherently decoupled when integrated on the same handset, while also other parameters such as frequency duplex distance and interaction with the users body influence the mutual coupling....

  19. Adjusting Surfaces Of Large Antenna Reflectors

    Science.gov (United States)

    Padula, Sharon L.; Adelman, Howard M.; Bailey, Marion C.; Hoftka, Raphael T.

    1989-01-01

    New approach more effective than traditional rms-surface-distortion approach. Optimization procedure for control of shape of reflector of large space antenna (LSA). Main feature is shape-controlling mathematical mechanism driven by need to satisfy explicit EM design requirements. Uses standard finite-element structural analysis, aperture-integration EM analysis, and constrained optimization techniques to predict set of actuator inputs that improves performance of antenna while minimizing applied control effort. Procedure applicable to wide variety of LSA concepts.

  20. Clinical significance of various diagnostic techniques and emerging antimicrobial resistance pattern of Helicobacter Pylori from Gastric Biopsy Samples

    Directory of Open Access Journals (Sweden)

    M A Vagarali

    2015-01-01

    Full Text Available Background: There is no single technique that can meet the criteria in identification of Helicobacter pylori. The diagnosis is important asantimicrobial resistance is frequently observed and associated with treatment failure. The present study was conducted to evaluate diagnostic tests for identification of H pylori and to assess their antimicrobial resistance pattern.Materials and Methods: Biopsies of gastric tissue from 200 patients with disorders of the upper gastrointestinal tract were studied for detection of H pylori by various methods like culture, H and E staining and urease test. Antimicrobial susceptibility testing was carried out by Kirby Bauer's disc diffusion method. Results: Out of 200 patients, H pylori was detected by rapid urease test, H and E staining and culture in 26.5%, 14.5% and 2.5% cases respectively. H and E was taken as the gold standard. Sensitivity of urease test was 76.6% and of culture 13.3%. Specificity of urease was 81.7% in comparison with culture which showed 99.4% specificity. Metronidazole (05 showed high level of resistance followed by amoxicillin (03 and norfloxacillin (03. Tetracycline, erythromycin, levofloxacin and cotrimoxazole showed one resistance each to H pylori. Conclusion: H and E is taken as the gold standard according to CDC. Urease test is a better screening procedure than culture. H pylori resistance to metronidazole in our zone was highest. This is due to general and extensive use of metronidazole for other infectious diseases. Our study suggests need for a systematic approach to determine antibiogram of the strains before considering the drug regimens.

  1. Diagnostic techniques for measuring temperature transients and stress transients in the first wall of an ICF reactor

    International Nuclear Information System (INIS)

    The primary challenge in the design of an Inertial Confinement Fusion (ICF) power reactor is to make the first wall survive the frequent explosions of the pellets. Westinghouse has proposed a dry wall design consisting of steel tubes coated with tantalum. This report describes the design of a test chamber and two diagnostic procedures for experimentally determining the reliability of the Westinghouse design. The test chamber simulates the x-ray and ion pulse irradiation of the wall due to a pellet explosion. The diagnostics consist of remote temperature sensing and surface deformation measurements. The chamber and diagnostics can also be used to test other first-wall designs

  2. Quantitative spectroscopy on individual wire, slot, bow-tie, rectangular, and square-shaped optical antennas.

    Science.gov (United States)

    Husnik, Martin; Niegemann, Jens; Busch, Kurt; Wegener, Martin

    2013-11-15

    By using a recently introduced approach combining a focus-modulation technique with a common-path interferometer, we measure quantitatively the extinction, scattering, and absorption cross-section spectra of individual optical antennas. The experimental results on thin-wire antennas, slot antennas, bow-tie antennas, rectangular antennas, and square-shaped antennas resonating at around 1.4 μm wavelength are discussed. We find increased resonant scattering cross sections for the latter four antennas compared to the thin-wire antenna, both in absolute terms and relative to the absorption cross section. The square-shaped antenna's resonant extinction cross section approaches the limit of a coherent point dipole. However, the ratio of the resonant extinction cross section to the geometrical cross section of 38 is largest for the simple thin-wire antenna. PMID:24322083

  3. Development of Millimeter-Wave Planar Antennas Using Low-Loss Materials

    Science.gov (United States)

    Ito, Naoki; Mase, Atsushi; Kogi, Yuichiro; Seko, Noriaki; Tamada, Masao; Shimazu, Hiroshi; Sakata, Eiji

    2010-10-01

    As the importance of advanced millimeter-wave diagnostics increases, the fabrication of high-performance devices and components becomes essential. In this paper, we describe the development of millimeter-wave planar antennas using low-loss fluorine substrates. The problems to be solved in this study are the low degree of adhesion between copper foil and the fluorine substrate and the accuracy of device pattern using conventional fabrication techniques. In order to solve these problems, a new surface treatment of fluorine films and a fabrication method using electro-fine-forming (EF2) are proposed. In order to confirm the performance of the treated films, microstrip lines (MSLs) and planar patch antennas with a low sidelobe level in the E-plane are designed and fabricated on conventional fluorine substrates and grafted poly(tetrafluoroethylene) (PTFE) films.

  4. Compact Triple Band Slotted Microstrip Patch Antenna

    Directory of Open Access Journals (Sweden)

    Ram Singh Kushwaha

    2012-03-01

    Full Text Available This paper presents a compact triple band slot microstrip patch antenna for 1.7/2.92 GHz WLAN applications. The radiating element of the proposed antenna consists of Swastika symbol slot operating at 1.8 GHz, 2.09 GHz, and 2.92 GHz bands. The antenna size is very compact (50 mm x 50 mm x 1.6 mm and covers 1.8 GHz to 2.92 GHz and can be used for AMPS, GSM and WLAN applications. The antenna is fed from a single 50 Ω coaxial cable. Using IE3D software package of Zeland, according to the set size, the antenna is simulated. The composite effect of integrating these techniques and by introducing the novel slotted patch offers a low profile, wide bandwidth, high gain and compact antenna element. The computer simulation results show that the antenna can realize wide band characters with each band having good impedance bandwidth (VSWR ≤ 2 for all the three resonant frequencies.

  5. A Fast MoM Calculation Technique Using Sinusoidal Basis and Testing Functions for a Wire on a Dielectric Substrate and Its Application to Meander Loop and Grid Array Antennas

    OpenAIRE

    Nakano, Hisamatsu; Kawano, Toru; Kozono, Yousuke; Yamauchi, Junji

    2005-01-01

    The input impedance matrix element of the method of moments (MoM) for an arbitrarily shaped wire antenna printed on a dielectric material Zm,n is formulated to be composed of three terms Zψsm,n, Zψm,n, and ΔZm,n involving single-, double-, and triple-integral calculations, respectively. The MoM based on the Zm,n formulated in this paper (new MoM) is applied to two antennas-a meander loop antenna and a grid array antenna-as well as a simple loop used as a reference antenna. The computation tim...

  6. Infrared dipole antenna enhanced by surface phonon polaritons.

    Science.gov (United States)

    Kim, Hyun Chul; Cheng, Xing

    2010-11-15

    In this Letter, we propose a gold dipole antenna formed on a SiC substrate to achieve a strong concentration of mid-IR radiation based on a synergistic integration of the IR dipole antenna and the resonance excitation of a surface phonon polariton. Numerical simulation based on the finite-difference time-domain technique shows that the intensity enhancement can be greater than 10(7) times at the mid-IR spectral region. The influence of the geometric parameters (i.e., antenna length, gap dimension, antenna thickness, and antenna width) on the antenna field enhancement is also studied. The strong intensity enhancement can find important applications in highly sensitive mid-IR photodetectors and in molecular detection and identification by surface-enhanced IR absorption spectroscopy techniques. PMID:21081984

  7. The detection of lumpy skin disease virus in samples of experimentally infected cattle using different diagnostic techniques

    Directory of Open Access Journals (Sweden)

    E.S.M. Tuppurainen

    2005-09-01

    Full Text Available Lumpy skin disease (LSD is a disease of cattle, primarily in Africa and Madagascar and rarely in the Middle East. It is caused by a capripoxvirus that belongs to the family Poxviridae. The disease is of economic importance in endemic areas. Effective control of LSD requires accurate and rapid laboratory techniques to confirm a tentative clinical diagnosis. Comparative studies on different diagnostic tests used at different stages of the disease have not been done. The aim of this study was to compare several of these tests. Six seronegative bulls, between 11 and 20 months of age, were infected intravenously and kept in an insect-free facility. The course of the infection was monitored. During a 3-month period blood samples and skin biopsies were collected for virus isolation and polymerase chain reaction (PCR. Skin biopsies were also examined using transmission electron microscopy (TEM. The incubation period in infected animals varied from 4-5 days. The length of the viraemic period did not correlate with the severity of clinical disease. Viraemia was detected from 1-12 days using virus isolation and from 4-11 days using the PCR, which is longer than has previously been reported. Virus was isolated from skin biopsies until Day 39 post infection (p.i. and PCR could demonstrate viral DNA until Day 92 p.i. Transmission electron microscopy of negatively stained skin biopsies detected LSD virus only in one of the four bulls that developed skin lesions until Day 33 p.i. The PCR was a fast and sensitive method to demonstrate viral DNA in blood and skin samples. It could detect viral nucleic acid in skin lesions 53 days longer than virus isolation. Virus isolation from blood and skin samples was sensitive and reliable, but as a single test it may be too time-consuming to use although this depends on how rapidly the diagnosis must be confirmed. In conclusion, this study showed the PCR to be superior in detecting LSD virus from blood and skin samples

  8. A True Metasurface Antenna

    Science.gov (United States)

    Badawe, Mohamed El; Almoneef, Thamer S.; Ramahi, Omar M.

    2016-01-01

    We present a true metasurface antenna based on electrically-small resonators. The resonators are placed on a flat surface and connected to one feed point using corporate feed. Unlike conventional array antennas where the distance between adjacent antennas is half wavelength to reduce mutual coupling between adjacent antennas, here the distance between the radiating elements is electrically very small to affect good impedance matching of each resonator to its feed. A metasurface antenna measuring 1.2λ × 1.2λ and designed to operate at 3 GHz achieved a gain of 12 dBi. A prototype was fabricated and tested showing good agreement between numerical simulations and experimental results. Through numerical simulation, we show that the metasurface antenna has the ability to provide beam steering by phasing all the resonators appropriately.

  9. Wideband scalable probe for Spherical Near-Field Antenna measurements

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Pivnenko, Sergey; Breinbjerg, Olav

    2011-01-01

    The paper presents a design of an open-boundary quad-ridged horn to be used as a wideband scalable dual-linearly polarized probe for spherical near-field antenna measurements. With a new higher-order probe correction technique developed at the Technical University of Denmark, the probe will enable...... high-accuracy wideband antenna measurements at the DTU-ESA Spherical Near-Field Antenna Test Facility at frequencies down to 400 MHz....

  10. A stochastic framework for the variability analysis of textile antennas

    OpenAIRE

    Rossi, Marco; Dierck, Arnaut; Rogier, Hendrik; Vande Ginste, Dries

    2014-01-01

    A novel framework to accurately quantify the effect of stochastic variations of design parameters on the performance of textile antennas is developed and tested. First, a sensitivity analysis is applied to get a rough idea about the effect of these random variations on the textile antenna's performance. Next, a more detailed view is obtained by a generalized polynomial chaos technique that accurately quantifies the statistical distribution of the textile antenna's figures of merit, for a give...

  11. Implantable microwave antennas for thermal therapy

    Science.gov (United States)

    Stauffer, Paul R.

    1998-04-01

    The purpose of this article is to review the physical construction and power deposition characteristics of interstitial microwave antennas that may be used for highly localized heating of tissue at depth in the human body. Several different antenna designs are described and matched with potential clinical applications that range from moderate temperature Hyperthermia therapy to tissue- necrosing Thermal Ablation therapy. Typical clinical procedures are outlined for thermal treatment of target sites such as brain, prostate, heart, and gynecologic region tissues. Associated methods of implanting the antennas and coupling microwave energy into the surrounding tissue are also described, including the use of single or multi-chamber stiff, flexible or inflatable balloon type catheters, with or without circulating air or water cooling. With numerous references to the primary literature, this material should provide a framework for analyzing potential new applications for interstitial microwave antennas, as derived from the physical capabilities and limitations of the available hardware and techniques.

  12. Preliminary experimental study of the antenna module for Alfven wave excitation system in TCABR Tokamak

    International Nuclear Information System (INIS)

    The results of the initial experimental studies of the Alfven wave antenna module, which is destined to be a part of the advanced antenna system of TCABR tokamak, are presented. The tests were carried out in a specially constructed vacuum chamber and included the measurement of antenna electrical parameters and testing of the power diagnostic tools. The complex impedances and inductive mutual coupling of antenna loops were measured and results were compared with theoretical calculations. The tests have shown that the parameters of the antenna module have values according to the design. (author)

  13. Design of a correlation electron cyclotron emission diagnostic for Alcator C-Moda)

    Science.gov (United States)

    Sung, C.; White, A. E.; Irby, J. H.; Leccacorvi, R.; Vieira, R.; Oi, C. Y.; Peebles, W. A.; Nguyen, X.

    2012-10-01

    A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have kθ ≤ 4.8 cm-1 (kθρs < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper.

  14. Antenna design and characterization based on the elementary antenna concept

    Science.gov (United States)

    Ligthart, L. P.

    An antenna-design technique based on an elementary-antenna model (an infinitesimal pillbox structure carrying electric and magnetic currents and containing propagating TEM fields) is developed and demonstrated. An EM description of a waveguide aperture is obtained by applying approximate boundary conditions at specific points; the transmitted field is developed locally into a set of TEM field components to compute the radiation pattern; and aperture matching is achieved by calculating the aperture reflection as well. Parallel-plate, circular, and rectangular waveguides; two single-polarization TEM waveguide radiators (with and without dielectric filling); a dielectric-filled dual-polarization TE(01) waveguide radiator; and a hybrid reflector array with limited beam switching based on the TE(01) radiator are presented.

  15. Antenna Structure Registration (ASR)

    Data.gov (United States)

    Federal Communications Commission — As part of its ongoing efforts to promote air safety, the Federal Communications Commission requires owners to register certain antenna structures (generally those...

  16. Cellular Reflectarray Antenna

    Science.gov (United States)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  17. A curl antenna

    OpenAIRE

    Nakano, Hisamatsu; Okuzawa, Shigeru; Ohishi, Katsumi; Mimaki, Hiroaki; Yamauchi, Junji

    1993-01-01

    A radiation element, designated as a curl antenna, is proposed for a circularly polarized antenna. The radiation characteristics of the curl are numerically analyzed. The gain is approximately 8.4 dB, and the 3-dB axial ratio criterion is 6.7%. Two aspects of curl array antennas are also presented: a decoupling factor between two curls and a circular array antenna consisting of 168 curls. Calculations show how the decoupling factor depends on the relative rotation angle of the two curls. The ...

  18. MASTER TELEVISION ANTENNA SYSTEM.

    Science.gov (United States)

    Rhode Island State Dept. of Education, Providence.

    SPECIFICATIONS FOR THE FURNISHING AND INSTALLATION OF TELEVISION MASTER ANTENNA SYSTEMS FOR SECONDARY AND ELEMENTARY SCHOOLS ARE GIVEN. CONTRACTOR REQUIREMENTS, EQUIPMENT, PERFORMANCE STANDARDS, AND FUNCTIONS ARE DESCRIBED. (MS)

  19. Myocardial tagging with steady state free precession techniques and semi-automatic postprocessing--impact on diagnostic value

    DEFF Research Database (Denmark)

    Johnson, Thorsten R C; Bayrhof, Nicole; Huber, Armin; Kuijer, Joost P A; Luechinger, Roger; Dietrich, Olaf; Stoevesandt, Dietrich; Pedersen, Dorthe; Reiser, Maximilian F; Schoenberg, Stefan O

    2007-01-01

    Our aim was to determine the diagnostic value of myocardial tagging sequences with regard to the evaluable share of the cardiac cycle. Thirty-three patients were examined at 1.5 T using tagging sequences with gradient-echo (GRE) readout, 18 patients at 1.5 T with steady-state free precession (SSFP......), and 11 patients at 3 T using GRE. Two observers graded image quality and determined the share of the cardiac cycle for which postprocessing could be performed (1, optimal; 2, little interaction; 3, whole cycle assessable; 4, diastole non-assessable; 5, systole incomplete; 6, non-diagnostic). With GRE...

  20. Diagnostic performance of state-of-the-art imaging techniques for morphological assessment of vascular abnormalities in patients with chronic thromboembolic pulmonary hypertension (CTEPH)

    International Nuclear Information System (INIS)

    To determine the most comprehensive imaging technique for the assessment of pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH). 24 patients with CTEPH were examined by ECG-gated multi-detector CT angiography (MD-CTA), contrast-enhanced MR angiography (ce-MRA) and selective digital subtraction angiography (DSA) within 3 days. Two readers in consensus separately evaluated each imaging technique (48 main, 144 lobar and 449 segmental arteries) for typical changes like complete obstructions, vessel cut-offs, intimal irregularities, incorporated thrombus formations, and bands and webs. A joint interpretation of all three techniques served as a reference standard. Based on image quality, there was no non-diagnostic examination by either imaging technique. DSA did not sufficiently display 1 main, 3 lobar and 4 segmental arteries. The pulmonary trunk was not assessable by DSA. One patient showed thrombotic material at this level only by MD-CTA and MRA. Sensitivity and specificity of MD-CTA regarding CTEPH-related changes at the main/lobar and at the segmental levels were 100%/100% and 100%/99%, of ce-MRA 83.1%/98.6% and 87.7%/98.1%, and of DSA 65.7%/100% and 75.8%/100%, respectively. ECG-gated MD-CTA proved the most adequate technique for assessment of the pulmonary arteries in the diagnostic work-up of CTEPH patients. (orig.)

  1. Optimized design of shields for diagnostic X rays with NCRP 147 technique; Diseno optimizado de blindajes para rayos X diagnostico con tecnica NCRP 147

    Energy Technology Data Exchange (ETDEWEB)

    Gama T, G. [Calidad XXI SA de CV, Zacatecas 67-007 Col. Roma, 06700 Mexico D.F. (Mexico)]. e-mail: cxxi@prodigy.net.mx

    2006-07-01

    A comparison among the design techniques of shielding for X-ray diagnostic rooms with the NCRP 49 (1976) report technique, AAPM 39 (1993) Y the one of the NCRP 147 (2005) technique. The designs correspond to a room of conventional X-rays, one of fluoroscopy, one of tomography Y one of mammography. In all the cases it demonstrates that the NCRP 49 technique overestimate the shieldings. The causes of the overestimation of the NCRP 49 can be attributed to: a) high values of the work charge that don't consider the spectral fluence of the photons that are present in each room, b) to the differences in the values of the kerma in air without attenuation for the dispersed primary radiation Y of leakage among both reports. (Author)

  2. Automated Antenna Design with Evolutionary Algorithms

    Science.gov (United States)

    Linden, Derek; Hornby, Greg; Lohn, Jason; Globus, Al; Krishunkumor, K.

    2006-01-01

    Current methods of designing and optimizing antennas by hand are time and labor intensive, and limit complexity. Evolutionary design techniques can overcome these limitations by searching the design space and automatically finding effective solutions. In recent years, evolutionary algorithms have shown great promise in finding practical solutions in large, poorly understood design spaces. In particular, spacecraft antenna design has proven tractable to evolutionary design techniques. Researchers have been investigating evolutionary antenna design and optimization since the early 1990s, and the field has grown in recent years as computer speed has increased and electromagnetic simulators have improved. Two requirements-compliant antennas, one for ST5 and another for TDRS-C, have been automatically designed by evolutionary algorithms. The ST5 antenna is slated to fly this year, and a TDRS-C phased array element has been fabricated and tested. Such automated evolutionary design is enabled by medium-to-high quality simulators and fast modern computers to evaluate computer-generated designs. Evolutionary algorithms automate cut-and-try engineering, substituting automated search though millions of potential designs for intelligent search by engineers through a much smaller number of designs. For evolutionary design, the engineer chooses the evolutionary technique, parameters and the basic form of the antenna, e.g., single wire for ST5 and crossed-element Yagi for TDRS-C. Evolutionary algorithms then search for optimal configurations in the space defined by the engineer. NASA's Space Technology 5 (ST5) mission will launch three small spacecraft to test innovative concepts and technologies. Advanced evolutionary algorithms were used to automatically design antennas for ST5. The combination of wide beamwidth for a circularly-polarized wave and wide impedance bandwidth made for a challenging antenna design problem. From past experience in designing wire antennas, we chose to

  3. Non-invasive, photonics-based diagnostic, imaging, monitoring, and light delivery techniques for the recognition, quantification and treatment of malignant and chronic inflammatory conditions

    Science.gov (United States)

    Davies, N.; Davies-Shaw, D.; Shaw, J. D.

    2007-02-01

    We report firsthand on innovative developments in non-invasive, biophotonic techniques for a wide range of diagnostic, imaging and treatment options, including the recognition and quantification of cancerous, pre-cancerous cells and chronic inflammatory conditions. These techniques have benefited from the ability to target the affected site by both monochromatic light and broad multiple wavelength spectra. The employment of such wavelength or color-specific properties embraces the fluorescence stimulation of various photosensitizing drugs, and the instigation and detection of identified fluorescence signatures attendant upon laser induced fluorescence (LIF) phenomena as transmitted and propagated by precancerous, cancerous and normal tissue. In terms of tumor imaging and therapeutic and treatment options, we have exploited the abilities of various wavelengths to penetrate to different depths, through different types of tissues, and have explored quantifiable absorption and reflection characteristics upon which diagnostic assumptions can be reliably based and formulated. These biophotonic-based diagnostic, sensing and imaging techniques have also benefited from, and have been further enhanced by, the integrated ability to provide various power levels to be employed at various stages in the procedure. Applications are myriad, including non-invasive, non destructive diagnosis of in vivo cell characteristics and functions; light-based tissue analysis; real-time monitoring and mapping of brain function and of tumor growth; real time monitoring of the surgical completeness of tumor removal during laser-imaged/guided brain resection; diagnostic procedures based on fluorescence life-time monitoring, the monitoring of chronic inflammatory conditions (including rheumatoid arthritis), and continuous blood glucose monitoring in the control of diabetes.

  4. A pilot study using laser-based technique for non-invasive diagnostics of hypertensive conditions in mice

    Science.gov (United States)

    Litvinova, Karina S.; Ahmad, Shakil; Wang, Keqing; Rafailov, Ilya E.; Sokolovski, Sergei G.; Zhang, Lin; Rafailov, Edik U.; Ahmed, Asif

    2016-02-01

    Endothelial dysfunction is directly linked to preeclampsia, a maternal hypertensive condition that is life threating for both the mother and the baby. Epidemiological studies show that women with a history of pre-eclampsia have an elevated risk for cardiovascular disease. Here we report a new non-invasive diagnostic test for preeclampsia in mice that allows us to non-invasively assess the condition of the animals during the experiment and treatment in established models of preeclampsia. A laser-based multifunctional diagnostics system (LAKK-M) was chosen to carry out non-invasive analysis of multiple parameters. The device was used to simultaneously record the microcirculatory blood flow and oxygen saturation, as well as fluorescence levels of endogenous fluorophores. Preliminary experiments were conducted on adenoviral (Ad-)- mediated overexpression of sFlt-1 (Ad-sFlt-1) to mimic preeclampsialike symptoms in mice. The recorded data displayed the ability of the LAKK-M diagnostics device to detect significant differences in perfusion measurements between the control and Ad-sFlt-1 treatment. Preliminary results provide a potential avenue to employ these diagnostics technology to monitor and aid in maintaining control of live animal conditions throughout the experiment and treatment.

  5. Directional borehole antenna - Theory

    International Nuclear Information System (INIS)

    A directional antenna has been developed for the borehole radar constructed during phase 2 of the Stripa project. The new antenna can determine the azimuth of a strong reflector with an accuracy of about 3 degrees as confirmed during experiments in Stripa, although the ratio of borehole diameter to wavelength is small, about 0.03. The antenna synthesizes the effect of a loop antenna rotating in the borehole from four signals measured in turn by a stationary antenna. These signals are also used to calculate an electric dipole signal and a check sum which is used to examine the function of the system. The theory of directional antennas is reviewed and used to design an antenna consisting of four parallel wires. The radiation pattern of this antenna is calculated using transmission line theory with due regard to polarization, which is of fundamental importance for the analysis of directional data. In particular the multipole expansion of the field is calculated to describe the antenna radiation pattern. Various sources of error, e.g. the effect of the borehole, are discussed and the methods of calibrating the antenna are reviewed. The ambiguity inherent in a loop antenna can be removed by taking the phase of the signal into account. Typical reflectors in rock, e.g. fracture zones an tunnels, may be modelled as simple geometrical structures. The corresponding analysis is described and exemplified on measurements from Stripa. Radar data is nowadays usually analyzed directly on the computer screen using the program RADINTER developed within the Stripa project. An algorithm for automatic estimation of the parameters of a reflector have been tested with some success. The relation between measured radar data and external coordinates as determined by rotational indicators is finally expressed in terms of Euler angles. (au)

  6. Recent Developments of Reflectarray Antennas in Dual-Reflector Configurations

    Directory of Open Access Journals (Sweden)

    Carolina Tienda

    2012-01-01

    Full Text Available Recent work on dual-reflector antennas involving reflectarrays is reviewed in this paper. Both dual-reflector antenna with a reflectarray subreflector and dual-reflectarrays antennas with flat or parabolic main reflectarray are considered. First, a general analysis technique for these two configurations is described. Second, results for beam scanning and contoured-beam applications in different frequency bands are shown and discussed. The performance and capabilities of these antennas are shown by describing some practical design cases for radar, satellite communications, and direct broadcast satellite (DBS applications.

  7. Thermal Loss Becomes an Issue for Tunable Narrow-band Antennas in Fourth Generation Handsets

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Morris, Art; Pedersen, Gert Frølund

    2015-01-01

    Antenna tuning is a very promising technique to cope with the expansion of the mobile communication frequency spectrum. Tunable antennas can address a wide range of operating frequencies, while being highly integrated. In particular, high-Q antennas (also named narrow-band antennas) are very...... compact, thus are good candidates to be embedded on fourth generation handsets. This study focuses on ‘high-Q’ tunable antennas and contributes with a characterisation of their loss mechanism, which is a major parameter in link-budget calculations. This study shows, through an example, that the tuner loss...... is not sufficient to explain the total loss of tunable antennas. It is found that thermal loss –because of the metal conductivity of the antenna itself – plays a major role in the loss mechanism of narrow-band tunable antennas. The investigated high-Q planar inverted F antenna designs exhibit a...

  8. Integrated solar panel antennas

    OpenAIRE

    Vaccaro, S.; P. TORRES; Mosig, J. R.; Shah, Arvind; Zürcher,, J.-F.; A. K. Skrivervik; Gardiol, F.; de Maagt, P.; Gerlach, L.

    2008-01-01

    A new antenna which combines solar cells and printed patches is presented. The antenna is designed so as to accommodate the solar cells that provide power to an MMIC amplifier. A 2×4 array is presented, which operates at the frequency of 3.76 GHz and has a bandwidth of 16% and gain up to 30 dBi (active).

  9. Entropy and Fractal Antennas

    OpenAIRE

    Emanuel Guariglia

    2016-01-01

    The entropies of Shannon, Rényi and Kolmogorov are analyzed and compared together with their main properties. The entropy of some particular antennas with a pre-fractal shape, also called fractal antennas, is studied. In particular, their entropy is linked with the fractal geometrical shape and the physical performance.

  10. Annular Planar Monopole Antennas

    OpenAIRE

    Chen, Z. N.; Ammann, Max; Chia, W.Y. W.; See, T.S. P.

    2002-01-01

    A type of annular planar monopole antenna is presented. The impedance and radiation characteristics of the monopole with different holes and feed gaps are experimentally examined. The measured results demonstrate that the proposed antenna is capable of providing significantly broad impedance bandwidth with acceptable radiation performance.

  11. Printed Triband Terminal Antenna

    OpenAIRE

    JOHN, MATTHIAS; Ammann, Max; Farrell, R.

    2005-01-01

    This paper presents a printed triple-band multibranch monopole for use in modern wireless systems. The antenna is designed to operate in three bands which cover virtually all wireless channels. Parameters of the antenna geometry are varied and the effects of these variations on the impedance bandwidth are shown.

  12. Development of impedance matching technologies for ICRF antenna arrays

    International Nuclear Information System (INIS)

    All high power ICRF heating systems include devices for matching the input impedance of the antenna array to the generator output impedance. For most types of antennas used, the input impedance is strongly time-dependent on timescales as rapid as 10-4 s, while the rf generators used are capable of producing full power only into a stationary load impedance. Hence, the dynamic response of the matching method is of great practical importance. In this paper, world-wide developments in this field over the past decade are reviewed. These techniques may be divided into several classes. The edge plasma parameters that determine the antenna array's input impedance may be controlled to maintain a fixed load impedance. The frequency of the rf source can be feedback controlled to compensate for changes in the edge plasma conditions, or fast variable tuning elements in the transmission line between the generator output and the antenna input connections can provide the necessary time-varying impedance transformation. In lossy passive schemes, reflected power due to the time-varying impedance of the antenna array is diverted to a dummy load. Each of these techniques can be applied to a pre-existing antenna system. If a new antenna is to be designed, recent advances allow the antenna array to have the intrinsic property of presenting a constant load to the feeding transmission lines despite the varying load seen by each antenna in the array

  13. Modeling and diagnostic techniques applicable to the analysis of pressure noise in pressurized water reactors and pressure-sensing systems

    International Nuclear Information System (INIS)

    Pressure noise data from a PWR are interpreted by means of a computer-implemented model. The model's parameters, namely hydraulic impedances and noise sources, are either calculated or deduced from fits to data. Its accuracy is encouraging and raises the possibility of diagnostic assistance for nuclear plant monitoring. A number of specific applications of pressure noise in the primary system of a PWR and in a pressure sensing system are suggested

  14. The Use of Heart Rate Variability Technique for Differential Diagnostics of Peptic Ulcer and Idiopathic Duodenal Ulcers

    OpenAIRE

    D.А. Chizhikov; L.B. Fomin; V. I. Borisov

    2015-01-01

    The aim of the investigation was to study the peculiarities of autonomic regulation using spectral analysis of heart rate variability for differential diagnostics of peptic ulcer and idiopathic duodenal ulcer. Materials and Methods. A stress level was assessed by vagosympathetic balance rate. Low-high frequency ratio in a frequency spectrum of heart rate was used as a marker of vagosympathetic balance of stress. Endoscopic findings were compared with Helicobacter pylori test, and autonomi...

  15. The Use of Heart Rate Variability Technique for Differential Diagnostics of Peptic Ulcer and Idiopathic Duodenal Ulcers

    Directory of Open Access Journals (Sweden)

    D.А. Chizhikov

    2015-06-01

    Full Text Available The aim of the investigation was to study the peculiarities of autonomic regulation using spectral analysis of heart rate variability for differential diagnostics of peptic ulcer and idiopathic duodenal ulcer. Materials and Methods. A stress level was assessed by vagosympathetic balance rate. Low-high frequency ratio in a frequency spectrum of heart rate was used as a marker of vagosympathetic balance of stress. Endoscopic findings were compared with Helicobacter pylori test, and autonomic status was studied using spectral analysis of heart rate variability. Results. We found significant differences in low/high frequency ratio in the spectrum of heart rate of patients with Hp-positive and Hp-negative duodenal ulcers. The result proved stress nature of idiopathic ulcers. Idiopathic ulcers are characterized by significant increase of LF/HF that can serve as a differential diagnostic criterion for different types of duodenal ulcers. Conclusion. Spectral analysis of heart rate variability can be used in differential diagnostics of peptic ulcers and idiopathic ulcers.

  16. Transcatheter Antenna For Microwave Treatment

    Science.gov (United States)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Raffoul, George W. (Inventor); Karasack, Vincent G. (Inventor); Pacifico, Antonio (Inventor); Pieper, Carl F. (Inventor)

    2000-01-01

    Method and apparatus are provided for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue to treat ventricular tachycardia and other arrhythmias 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 operation, microwave energy between about 1 Gigahertz and 12 Gigahertz is applied to monopole microwave radiation having a surface wave limiter. A test setup provides physical testing of microwave radiators to determine the temperature profile created in actual heart tissue or ersatz heart tissue. Saline solution pumped over the heart tissue with a peristaltic pump simulates blood flow. Optical temperature sensors disposed at various tissue depths within the heart tissue detect the temperature profile without creating any electromagnetic interference. The method may he used to produce a desired temperature profile in other body tissues reachable by catheter such as tumors and the like.

  17. Failure behavior identification for a space antenna via neural networks

    Science.gov (United States)

    Sartori, Michael A.; Antsaklis, Panos J.

    1992-01-01

    By using neural networks, a method for the failure behavior identification of a space antenna model is investigated. The proposed method uses three stages. If a fault is suspected by the first stage of fault detection, a diagnostic test is performed on the antenna. The diagnostic test results are used by the second and third stages to identify which fault occurred and to diagnose the extent of the fault, respectively. The first stage uses a multilayer perceptron, the second stage uses a multilayer perceptron and neural networks trained with the quadratic optimization algorithm, a novel training procedure, and the third stage uses backpropagation trained neural networks.

  18. Diagnostic development

    International Nuclear Information System (INIS)

    During the past year the far-infrared or submillimeter diagnostic research program resulted in three major developments: (1) an optically pumped 0.385-μm D2O-laser oscillator-amplifier system was operated at a power level of 1 MW with a line width of less than 50 MHz; (2) a conical Pyrex submillimeter laser beam dump with a retention efficiency greater than 104 was developed for the ion temperature Thompson scattering experiment; and (3) a new diagnostic technique was developed that makes use of the Faraday rotation of a modulated submillimeter laser beam to determine plasma current profile. Measurements of the asymmetric distortion of the H/sub α/ (6563 A) spectral line profile show that the effective toroidal drift velocity, dv/sub two vertical bars i/dT/sub i/, may be used as an indicator of plasma quality and as a complement to other ion temperature diagnostics

  19. RF MEMS Based Reconfigurable Antennas

    Science.gov (United States)

    Simons, Rainee N.

    2004-01-01

    The presentation will first of all address the advantages of RF MEMS circuit in antenna applications and also the need for electronically reconfigurable antennas. Next, discuss some of the recent examples of RF MEMS based reconfigurable microstrip antennas. Finally, conclude the talk with a summary of MEMS antenna performance.

  20. Plasma Diagnostics

    International Nuclear Information System (INIS)

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  1. Facilities and techniques for x-ray diagnostic calibration in the 100-eV to 100-keV energy range

    International Nuclear Information System (INIS)

    The Lawrence Livermore National Laboratory (LLNL) has been a pioneer in the field of x-ray diagnostic calibration for more than 20 years. We have built steady state x-ray sources capable of supplying fluorescent lines of high spectral purity in the 100-eV to 100-keV energy range, and these sources have been used in the calibration of x-ray detectors, mirrors, crystals, filters, and film. This paper discusses our calibration philosophy and techniques, and describes some of our x-ray sources. Examples of actual calibration data are presented as well

  2. Adaptive antennas and receivers

    CERN Document Server

    Weiner, Melvin M

    2005-01-01

    In our modern age of remote sensing, wireless communication, and the nearly endless list of other antenna-based applications, complex problems require increasingly sophisticated solutions. Conventional antenna systems are no longer suited to high-noise or low-signal applications such as intrusion detection. Detailing highly effective approaches to non-Gaussian weak signal detection, Adaptive Antennas and Receivers provides an authoritative introduction to state-of-the-art research on the modeling, testing, and application of these technologies.Edited by innovative researcher and eminent expert

  3. Atacama Compact Array Antennas

    OpenAIRE

    Saito, Masao; Inatani, Junji; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high...

  4. Optimisation of Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    H. El Hamchary

    1996-04-01

    Full Text Available When choosing the most appropriate microstrip antenna configuration for particular applications, the kind of excitation of the radiating element is an essential factor that requires careful considerations. For controlling the distribution of energy of the linear or planar array of elements and for coupling energy to the individual elements, a wide variety of feed mechanisms are available. In this paper, the coaxial antenna feeding is assumed and the best (optimised feeding is found. Then, antenna characteristics such as radiation pattern, return loss, input impedance, and VSWR are obtained.

  5. Tunable Liquid Dielectric Antenna

    Directory of Open Access Journals (Sweden)

    Kamal Raj Singh Rajoriya

    2012-06-01

    Full Text Available This paper presents on modified the dielectric properties of liquid with varying salinity that was based on monopole structure. Dielectric resonator antennas (DRAs can be made with a wide range of materials and allow many excitation methods [2]. Pure water does not work at high frequency (> 1 GHz but increase in the salinity of water modifies the dielectric properties of water. Here proposed antenna shows that when the salinity increases in form of molar solution, the antenna was tuned at different frequency with increases return loss.

  6. Progress in integrated-circuit horn antennas for receiver applications. Part 1: Antenna design

    Science.gov (United States)

    Eleftheriades, George V.; Ali-Ahmad, Walid Y.; Rebeiz, Gabriel M.

    1992-01-01

    The purpose of this work is to present a systematic method for the design of multimode quasi-integrated horn antennas. The design methodology is based on the Gaussian beam approach and the structures are optimized for achieving maximum fundamental Gaussian coupling efficiency. For this purpose, a hybrid technique is employed in which the integrated part of the antennas is treated using full-wave analysis, whereas the machined part is treated using an approximate method. This results in a simple and efficient design process. The developed design procedure has been applied for the design of a 20, a 23, and a 25 dB quasi-integrated horn antennas, all with a Gaussian coupling efficiency exceeding 97 percent. The designed antennas have been tested and characterized using both full-wave analysis and 90 GHz/370 GHz measurements.

  7. Improvement of a MIMO antenna structure with combination of transmit beamforming and spatial multiplexing

    Institute of Scientific and Technical Information of China (English)

    YUAN Ting-ting; ZHANG Lei; YANG Hong-wen; YANG Da-cheng

    2008-01-01

    Downlinks of the cellular systems generally havemore transmit antennas than receive antennas. To efficientlyexploit all antenna resources, a technique that combines theadvantage of beamforming and spatial multiplexing has beenproposed, which partitions the transmit antennas into neigh-boring sub-groups. In this article, this technique is furtherimproved by Eq. (1) allowing non-contiguous antenna grouping,and Eq. (2) adopting two new grouping criteria: minimumsignal distance maximization(MSDM) criterion and maximumcorrelation coefficient minimization (MCCM) criterion. Simulationresults indicate that these improvements can bring noticeablegains in the Rayleigh flat fading channel environment.

  8. Investigation of ionospheric disturbances and associated diagnostic techniques. Final report, 1 January 1992-31 December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, L.M.

    1995-12-12

    The objectives of this research and development program were to conduct simulation modeling of the generation and propagation of atmospheric acoustic signals associated with surface and subsurface ground disturbances; to construct an experimental measurement system for exploratory research studies of acoustic generated ionospheric disturbances; to model high power radio wave propagation through the ionosphere, including nonlinear wave plasma interaction effects; and to assist in the assessment of diagnostic systems for observation of ionospheric modification experiments using existing and planned high latitude high power RF transmitting facilities. A computer simulation of ionospheric response to ground launched acoustic pulses was constructed and results compared to observational data associated with HF and incoherent scatter radar measurements of ionospheric effects produced by earthquakes and ground level explosions. These results were then utilized to help define the design, construct and test for an HF Doppler radar system. In addition, an assessment was conducted of ionospheric diagnostic instruments proposed for the Air Force/Navy High Frequency Active Auroral Research Program (HAARP).

  9. A Rectangular Planar Spiral Antenna for GIS Partial Discharge Detection

    Directory of Open Access Journals (Sweden)

    Xiaoxing Zhang

    2014-01-01

    Full Text Available A rectangular planar spiral antenna sensor was designed for detecting the partial discharge in gas insulation substations (GIS. It can expediently receive electromagnetic waves leaked from basin-type insulators and can effectively suppress low frequency electromagnetic interference from the surrounding environment. Certain effective techniques such as rectangular spiral structure, bow-tie loading, and back cavity structure optimization during the antenna design process can miniaturize antenna size and optimize voltage standing wave ratio (VSWR characteristics. Model calculation and experimental data measured in the laboratory show that the antenna possesses a good radiating performance and a multiband property when working in the ultrahigh frequency (UHF band. A comparative study between characteristics of the designed antenna and the existing quasi-TEM horn antenna was made. Based on the GIS defect simulation equipment in the laboratory, partial discharge signals were detected by the designed antenna, the available quasi-TEM horn antenna, and the microstrip patch antenna, and the measurement results were compared.

  10. [Epidemics of schistosomiasis in military staff assigned to endemic areas: standard diagnostic techniques and the development of real-time PCR techniques].

    Science.gov (United States)

    Biance-Valero, E; De Laval, F; Delerue, M; Savini, H; Cheinin, S; Leroy, P; Soullié, B

    2013-05-01

    The authors report the results of molecular biology techniques for the early diagnosis of cases (invasion phase) of schistosomiasis during two epidemics occurring during French military projects in the Central African Republic and Madagascar. The use of these techniques in real time for subjects not residing in the endemic area significantly improves the sensitivity of screening. The attack rates of these episodes, according to a case definition that took positive specific PCR results into account, were 59% and 26%. These results are a concrete illustration of the proverb that "yaws begin where the trail stops". PMID:24001641

  11. Research on the Scattering Characteristics and the RCS Reduction of Circularly Polarized Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    W. Jiang

    2013-01-01

    Full Text Available Based on the study of the radiation and scattering of the circularly polarized (CP antenna, a novel radar cross-section (RCS reduction technique is proposed for CP antenna in this paper. Quasi-fractal slots are applied in the design of the antenna ground plane to reduce the RCS of the CP antenna. Both prototype antenna and array are designed, and their time-, frequency-, and space-domain characteristics are studied to authenticate the proposed technique. The simulated and measured results show that the RCS of the prototype antenna and array is reduced up to 7.85 dB and 6.95 dB in the band of 1 GHz–10 GHz. The proposed technique serves a candidate in the design of low RCS CP antennas and arrays.

  12. Nonlinear plasmonic antennas

    Directory of Open Access Journals (Sweden)

    Shakeeb Bin Hasan

    2014-12-01

    Full Text Available Contrary to traditional optical elements, plasmonic antennas made from nanostructured metals permit the localization of electromagnetic fields on length scales much smaller than the wavelength of light. This results in huge amplitudes for the electromagnetic field close to the antenna being conducive for the observation of nonlinear effects already at moderate pump powers. Thus, these antennas exhibit a promising potential to achieve optical frequency conversion and all-optical control of light at the nano-scale. This opens unprecedented opportunities for ultrafast nonlinear spectroscopy, sensing devices, on-chip optical frequency conversion, nonlinear optical metamaterials, and novel photon sources. Here, we review some of the recent advances in exploiting the potential of plasmonic antennas to realize robust nonlinear applications.

  13. Fractal multiband patch antenna

    OpenAIRE

    Borja, C.; Puente Baliarda, Carles; Romeu Robert, Jordi; Anguera Pros, Jaume

    2000-01-01

    The multiband behaviour of the Sierpinski patch antenna is described in this paper. Experimental results show that the self similarity properties of the fractal shape are translated into its electromagnetic behaviour. Peer Reviewed

  14. Atacama Compact Array Antennas

    CERN Document Server

    Saito, Masao; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.

  15. Rotary antenna attenuator

    Science.gov (United States)

    Dickinson, R. M.; Hardy, J. C.

    1969-01-01

    Radio frequency attenuator, having negligible insertion loss at minimum attenuation, can be used for making precise antenna gain measurements. It is small in size compared to a rotary-vane attenuator.

  16. Image based measurement techniques for aircraft propeller flow diagnostics: Propeller slipstream investigations at high-lift conditions and thrust reverse

    OpenAIRE

    Roosenboom, E.W.M.

    2011-01-01

    The aim of the thesis is to measure the propeller slipstream properties (velocity and vorticity) and to assess the unsteady and instantaneous behavior of the propeller flow field at high disk loadings, zero thrust and thrust reverse using the image based measurement techniques. Along with its implementation of the techniques in industrial facilities particular propeller phenomena are addressed, such as the propeller slipstream behavior at varying angles of attack, and its interaction with the...

  17. Intelsat VI antenna system

    Science.gov (United States)

    Caulfield, M. F.; Lane, S. O.; Taormina, F. A.

    The antenna system design of a series of five new communications satellites known as Intelsat VI is described in detail. Each satellite will utilize 50 transponders operating in the C and K band portions of the frequency spectrum. The transponders are interconnectible using either static switch matrices or a network which provides satellite switched time division multiple access capability. The antenna coverages, characteristics, and special design features are shown and discussed.

  18. New approaches to analysis and synthesis of reflector antennas

    Science.gov (United States)

    Galindo-Israel, V.; Mittra, R.

    1978-01-01

    Recently developed techniques are reviewed for analyzing and synthesizing single and dual antennas for high efficiency and wide angle scan. The problem of contour beam synthesis using superposition of pencil beams is also discussed.

  19. Microwave radiation hazards around large microwave antenna.

    Science.gov (United States)

    Klascius, A.

    1973-01-01

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

  20. Direction of Onset estimation using Multiple Signal Classification, Estimation of Signal Parameter by Revolving Invariance Techniques and Maximumlikelihood Algorithms for Antenna arrays

    Directory of Open Access Journals (Sweden)

    Yuvaraja.T

    2015-12-01

    Full Text Available In this paper a comparison of the performance of three famous Eigen structure based Direction of arrival (DOA algorithms known as the Multiple Signal Classification (MUSIC, the Estimation of Signal Parameter via Rotational Invariance Techniques (ESPRIT and a non-subspace method maximum-likelihood estimation (MLE has been extensively studied in this research work The performance of this DOA estimation algorithm based on Uniform Linear Array (ULA. We estimated various DOA using MATLAB, results shows that MUSIC algorithm is more accurate and stable compared to ESPRIT and MLE algorithms.

  1. Effects of measurement errors on microwave antenna holography

    Science.gov (United States)

    Rochblatt, David J.; Rahmat-Samii, Yahya

    1991-01-01

    The effects of measurement errors appearing during the implementation of the microwave holographic technique are investigated in detail, and many representative results are presented based on computer simulations. The numerical results are tailored for cases applicable to the utilization of the holographic technique for the NASA's Deep Space Network antennas, although the methodology of analysis is applicable to any antenna. Many system measurement topics are presented and summarized.

  2. Image based measurement techniques for aircraft propeller flow diagnostics: Propeller slipstream investigations at high-lift conditions and thrust reverse

    NARCIS (Netherlands)

    Roosenboom, E.W.M.

    2011-01-01

    The aim of the thesis is to measure the propeller slipstream properties (velocity and vorticity) and to assess the unsteady and instantaneous behavior of the propeller flow field at high disk loadings, zero thrust and thrust reverse using the image based measurement techniques. Along with its implem

  3. Measuring Helical FCG Voltage with an Electric Field Antenna

    Energy Technology Data Exchange (ETDEWEB)

    White, A D; Anderson, R A; Javedani, J B; Reisman, D B; Goerz, D A; Ferriera, A J; Speer, R D

    2011-08-01

    A method of measuring the voltage produced by a helical explosive flux compression generator using a remote electric field antenna is described in detail. The diagnostic has been successfully implemented on several experiments. Measured data from the diagnostic compare favorably with voltages predicted using the code CAGEN, validating our predictive modeling tools. The measured data is important to understanding generator performance, and is measured with a low-risk, minimally intrusive approach.

  4. Analysis of three-dimensional-cavity-backed aperture antennas using a Combined Finite Element Method/Method of Moments/Geometrical Theory of Diffraction technique

    Science.gov (United States)

    Reddy, C. J.; Deshpande, M. D.; Cockrell, C. R.; Beck, F. B.

    1995-01-01

    A combined finite element method (FEM) and method of moments (MoM) technique is presented to analyze the radiation characteristics of a cavity-fed aperture in three dimensions. Generalized feed modeling has been done using the modal expansion of fields in the feed structure. Numerical results for some feeding structures such as a rectangular waveguide, circular waveguide, and coaxial line are presented. The method also uses the geometrical theory of diffraction (GTD) to predict the effect of a finite ground plane on radiation characteristics. Input admittance calculations for open radiating structures such as a rectangular waveguide, a circular waveguide, and a coaxial line are shown. Numerical data for a coaxial-fed cavity with finite ground plane are verified with experimental data.

  5. SANTANA- Smart Antenna Terminal Design

    OpenAIRE

    Liu, Ying

    2006-01-01

    This project is embedded in SANTANA (Smart Antenna Terminal) project. The project goal is to design a Ka-band circularly polarized antenna radiator for the receiver SANTANA system. The research work focuses on two types of circularly polarized antennas: aperture-coupled patch antenna and CPW-fed patch antenna. A two steps design process is used. Firstly, only the antennas and their feed structure are designed and optimized. Secondly, a via-transition to connect to a MMIC layer is added. When ...

  6. Modeling of compact loop antennas

    Science.gov (United States)

    Baity, F. W.

    1987-09-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively tuned resonant double loop (RDL) antennas, the model treats sub-tuned RDL antennas. Calculations using the model have been compared with measurements on full-scale mock-ups of RDL antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and the Compact Ignition Tokamak (CIT).

  7. Modeling of compact loop antennas

    International Nuclear Information System (INIS)

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak

  8. Modeling of compact loop antennas

    International Nuclear Information System (INIS)

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively tuned resonant double loop (RDL) antennas, the model treats sub-tuned RDL antennas. Calculations using the model have been compared with measurements on full-scale mock-ups of RDL antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and the Compact Ignition Tokamak

  9. Investigation of radiation protection of medical staff performing medical diagnostic examinations by using PET/CT technique

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is now one of the most important methods in the diagnosis of cancer diseases. Due to the rapid growth of PET/CT centres in Poland in less than a decade, radiation protection and, consequently, the assessment of worker exposure to ionising radiation, emitted mainly by the isotope 18F, have become essential issues. The main aim of the study was to analyse the doses received by workers employed in the Medical Diagnostic Centre. The analysis comprises a physicist, three nurses, three physicians, three technicians, as well as two administrative staff employees. High-sensitivity thermoluminescent detectors (TLDs) were used to measure the doses for medical staff. The personnel was classified into categories, among them employees having direct contact with the ‘source of radiation’—18FDG. The TLDs were placed on the fingertips of both hands and they were also attached at the level of eye lenses, thyroid and gonads depending on the assigned category. The highest dose of radiation was observed during the administration of the 18FDG to the patients. In the case of the physicist, the highest dose was recorded during preparation of the radiopharmaceutical—18FDG. The body parts most exposed to ionizing radiation are the fingertips of the thumb, index and middle finger. (paper)

  10. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Robey, H F; Munro, D H; Spears, B K; Marinak, M M; Jones, O S; Patel, M V; Haan, S W; Salmonson, J D; Landen, O L [Lawrence Livermore National Laboratory, Livermore, CA (United States); Boehly, T R [Laboratory for Laser Energetics, Rochester, NY (United States); Nikroo, A [General Atomics, San Diego, CA (United States)], E-mail: robey1@llnl.gov

    2008-05-15

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of {<=} +/- 100ps. To meet these stringent requirements, dedicated tuning experiments are being planned to measure and adjust the shock timing on NIF. These tuning experiments will be performed in a modified hohlraum geometry, where a re-entrant Au cone is added to the standard NIF hohlraum to provide optical diagnostic (VISAR and SOP) access to the shocks as they break out of the ablator. This modified geometry is referred to as the 'keyhole' hohlraum and introduces a geometric difference between these tuning-experiments and the full ignition geometry. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum.

  11. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    International Nuclear Information System (INIS)

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of ≤ +/- 100ps. To meet these stringent requirements, dedicated tuning experiments are being planned to measure and adjust the shock timing on NIF. These tuning experiments will be performed in a modified hohlraum geometry, where a re-entrant Au cone is added to the standard NIF hohlraum to provide optical diagnostic (VISAR and SOP) access to the shocks as they break out of the ablator. This modified geometry is referred to as the 'keyhole' hohlraum and introduces a geometric difference between these tuning-experiments and the full ignition geometry. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum

  12. A Short Review of Passive R. F. Electric Antennas as In Situ Detectors of Space Plasmas

    International Nuclear Information System (INIS)

    We review the basic principles and recent or planned applications of passive, radio frequency electric antennas for in situ measurements of dusty plasmas in space. Electric antennas as passive wave detectors are reliable and versatile tools for such measurements, with the technique of Quasi Thermal Noise Spectroscopy and its generalization to dusty plasmas. The technique has been applied in the interplanetary medium, cometary plasma and dust tails, plasma environments of the Earth, Venus, Jupiter (including the Io plasma torus), Saturn (including the plasma torus and the E ring), with antennas of various shape aboard a number of spacecraft, including, most recently, Cassini. The technique is in the course of use on STEREO (NASA) in interplanetary magnetic clouds, is selected on MMO/Bepi-Colombo (JAXA-ESA) for in situ plasma measurements at Mercury, and planned on the Solar Orbiter (ESA) and other spacecraft projects. The diagnostic is based on the spectral analysis of the electric potential induced by the plasma particles as they pass by the antennas, and/or impact them or the spacecraft. The technique has a great advantage over usual electron detectors: its cross section for detection is much larger than the surface of the detector itself, ensuring a great sensitivity and a quasi-immunity to spacecraft perturbations. The spectral density induced by the passage of plasmas particles - with their dressing popularly known as Debye shielding, Langmuir waves, Bernstein waves and other members of the plasma menagerie - is easily calculated under stable conditions from the theory of the plasma quasi-thermal fluctuations. Around the plasma frequency, the spectrum is dominated by the QTN while at lower frequencies the spectrum is dominated by the shot noise produced by particles impacts on the antenna (in dipole mode) or on the spacecraft (in monopole mode). In this last case, the shot noise can be strongly enhanced by the impacts (and subsequent volatilization

  13. Tri-band microstrip antenna design for wireless communication applications

    Science.gov (United States)

    Sami, Gehan; Mohanna, Mahmoud; Rabeh, Mohamed L.

    2013-06-01

    This paper introduces a novel rectangular tri-band patch antenna that is fabricated and measured for wireless communication systems. The introduced antenna is designed for WLAN and WiMAX applications. The desired tri-band operation was obtained by proper loading for a rectangular patch antenna using slots and shorting pins. The optimal location and dimension for the loaded elements were obtained with the aid of interfacing a Genetic Algorithm (GA) model with an Ansoft High Frequency Structural Simulator (HFSS). The results obtained from our simulated antenna show 5.8% impedance matching band width at 2.4 GHz, 3.7% at 3.5 GHz and 1.57% at 5.7 GHz. In addition, an equivalent circuit of the proposed antenna is introduced using the least square curve fitting optimization technique.

  14. Phase Retrieval for Radio Telescope and Antenna Control

    Science.gov (United States)

    Dean, Bruce

    2011-01-01

    Phase-retrieval is a general term used in optics to describe the estimation of optical imperfections or "aberrations." The purpose of this innovation is to develop the application of phase retrieval to radio telescope and antenna control in the millimeter wave band. Earlier techniques do not approximate the incoherent subtraction process as a coherent propagation. This approximation reduces the noise in the data and allows a straightforward application of conventional phase retrieval techniques for radio telescope and antenna control. The application of iterative-transform phase retrieval to radio telescope and antenna control is made by approximating the incoherent subtraction process as a coherent propagation. Thus, for systems utilizing both positive and negative polarity feeds, this approximation allows both surface and alignment errors to be assessed without the use of additional hardware or laser metrology. Knowledge of the antenna surface profile allows errors to be corrected at a given surface temperature and observing angle. In addition to imperfections of the antenna surface figure, the misalignment of multiple antennas operating in unison can reduce or degrade the signal-to-noise ratio of the received or broadcast signals. This technique also has application to the alignment of antenna array configurations.

  15. Developing novel 3D antennas using advanced additive manufacturing technology

    Science.gov (United States)

    Mirzaee, Milad

    In today's world of wireless communication systems, antenna engineering is rapidly advancing as the wireless services continue to expand in support of emerging commercial applications. Antennas play a key role in the performance of advanced transceiver systems where they serve to convert electric power to electromagnetic waves and vice versa. Researchers have held significant interest in developing this crucial component for wireless communication systems by employing a variety of design techniques. In the past few years, demands for electrically small antennas continues to increase, particularly among portable and mobile wireless devices, medical electronics and aerospace systems. This trend toward smaller electronic devices makes the three dimensional (3D) antennas very appealing, since they can be designed in a way to use every available space inside the devise. Additive Manufacturing (AM) method could help to find great solutions for the antennas design for next generation of wireless communication systems. In this thesis, the design and fabrication of 3D printed antennas using AM technology is studied. To demonstrate this application of AM, different types of antennas structures have been designed and fabricated using various manufacturing processes. This thesis studies, for the first time, embedded conductive 3D printed antennas using PolyLactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) for substrate parts and high temperature carbon paste for conductive parts which can be a good candidate to overcome the limitations of direct printing on 3D surfaces that is the most popular method to fabricate conductive parts of the antennas. This thesis also studies, for the first time, the fabrication of antennas with 3D printed conductive parts which can contribute to the new generation of 3D printed antennas.

  16. IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION

    Directory of Open Access Journals (Sweden)

    Tuanne Rotti ABRANTES

    2016-01-01

    Full Text Available After the report of a second case of canine visceral leishmaniasis (CVL in São Bento da Lagoa, Itaipuaçu, in the municipality of Maricá, Rio de Janeiro State, an epidemiological survey was carried out, through active search, totaling 145 dogs. Indirect immunofluorescence assay (IFA, enzyme-linked immunosorbent assay (ELISA, and rapid chromatographic immunoassay based on dual-path platform (DPP(r were used to perform the serological examinations. The parasitological diagnosis of cutaneous fragments was performed by parasitological culture, histopathology, and immunohistochemistry. In the serological assessment, 21 dogs were seropositive by IFA, 17 by ELISA, and 11 by DPP(r, with sensitivity of 66.7%, 66.7% and 50%, and specificity of 87.2%, 90.2% and 94%, respectively for each technique. The immunohistochemistry of bone marrow using the cell-block technique presented the best results, with six positive dogs found, three of which tested negative by the other parasitological techniques. Leishmania sp. was isolated by parasitological culture in three dogs. The detection of autochthonous Leishmania infantum in Itaipuaçu, and the high prevalence of seropositive dogs confirm the circulation of this parasite in the study area and alert for the risk of expansion in the State of Rio de Janeiro.

  17. Imaging antenna arrays

    Science.gov (United States)

    Rutledge, D. B.; Muha, M. S.

    1982-01-01

    Many millimeter and far-infrared imaging systems are limited in sensitivity and speed because they depend on a single scanned element. Because of recent advances in planar detectors such as Schottky diodes, superconducting tunnel junctions, and microbolometers, an attractive approach to this problem is a planar antenna array with integrated detectors. A planar line antenna array and optical system for imaging has been developed. The significant advances are a 'reverse-microscope' optical configuration and a modified bow-tie antenna design. In the 'reverse-microscope' configuration, a lens is attached to the bottom of the substrate containing the antennas. Imaging is done through the substrate. This configuration eliminates the troublesome effects of substrate surface waves. The substrate lens has only a single refracting surface, making possible a virtually aplanatic system, with little spherical aberration or coma. The array is characterized by an optical transfer function that is easily measured. An array with 19 dB crosstalk levels between adjacent antennas has been tested and it was found that the array captured 50 percent of the available power. This imaging system was diffraction limited.

  18. Gain Enhancement and comparison of rectangular slot patch antenna circular slot patch antenna using dual FSS superstrate Layer

    Directory of Open Access Journals (Sweden)

    Preeti Chaudhary,

    2013-10-01

    Full Text Available In this paper, Circular Microstrip Patch Antenna and Rectangular Slot Patch Antenna comparison of present and an effort is made to optimize the gain to show better performance analysis on the basis of design and simulation results by implementing FSS structured superstrate layer at operating frequency of 5.8 GHz for ISM Band. The proposed design will be fed by coaxial probe feed, in order to get proper impedance matching. Design technique for enhancing Bandwidth that improves the performance of a conventional microstrip patch antenna is proposed. In order to show our results better, we have made a comparative analysis with conventional microstrip patch antenna, at the same frequency band to increase the gain, directivity and minimize the return loss of the desired antenna. This simulation results are carried out by using Ansoft based HFSS software.

  19. Plasma diagnostics discharge parameters and chemistry

    CERN Document Server

    Auciello, Orlando

    1989-01-01

    Plasma Diagnostics, Volume 1: Discharge Parameters and Chemistry covers seven chapters on the important diagnostic techniques for plasmas and details their use in particular applications. The book discusses optical diagnostic techniques for low pressure plasmas and plasma processing; plasma diagnostics for electrical discharge light sources; as well as Langmuir probes. The text also describes the mass spectroscopy of plasmas, microwave diagnostics, paramagnetic resonance diagnostics, and diagnostics in thermal plasma processing. Electrical engineers, nuclear engineers, microwave engineers, che

  20. Technologies and Applications of Microwave Photonic Antennas

    OpenAIRE

    Y. Yashchyshyn; Chizh, A.; Malyshev, S.; Modelski, J

    2010-01-01

    This paper describes the development of microwave photonic antennas concepts and their applications. The experimental study of the transmitting and receiving photonic antenna are shown. The transmitting photonic antenna consists of photodiode integrated with microstrip E-shaped patch antenna, and receiving photonic antenna consists of laser diode integrated directly with the Vivaldi antenna.

  1. Laser fusion diagnostics

    International Nuclear Information System (INIS)

    High temporal and spatial resolution optical diagnostics of laser performance, energy balance, and applicable plasma probing techniques are reviewed. A variety of spatially, temporally and spectrally resolved x-ray diagnostics techniques and instruments are discussed. Particular emphasis is on high spatial resolution imaging techniques and applications and on high temporal resolution x-ray streak caera applications to exploding pusher target experiments. Finally, particle diagnostics and system designed to diagnose target performance via yield and temperature measurements and techniques designed to determine the characteristics of compressed targets are discussed

  2. Hemispheric ultra-wideband antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2006-04-01

    This report begins with a review of reduced size ultra-wideband (UWB) antennas and the peculiar problems that arise when building a UWB antenna. It then gives a description of a new type of UWB antenna that resolves these problems. This antenna, dubbed the hemispheric conical antenna, is similar to a conventional conical antenna in that it uses the same inverted conical conductor over a ground plane, but it also uses a hemispheric dielectric fill in between the conductive cone and the ground plane. The dielectric material creates a fundamentally new antenna which is reduced in size and much more rugged than a standard UWB conical antenna. The creation of finite-difference time domain (FDTD) software tools in spherical coordinates, as described in SAND2004-6577, enabled this technological advance.

  3. Dual polarization flat plate antenna

    Science.gov (United States)

    Kelly, Kenneth C.

    Rectangular waveguides with radiating slots are used in groups to form planar array microwave antennas with large apertures and small depth. Such flat plate antennas are widely used on spacecraft and aircraft. Typically, flat plate antennas provide fixed linear polarization. The present paper describes a new flat plate antenna which produces two coincident beams that are distinguished by their orthogonal linear polarizations. The antenna has two ports, one for each of the coicident beams. Completely external to the antenna, connecting a simple network to those terminal ports enables the antenna to provide right circular polarization from one port and left from the other. A different external network enables the antenna to have arbitrarily adjustable polarizations.

  4. 96-antenna radioheliograph

    CERN Document Server

    Lesovoi, S V; Ivanov, E F; Gubin, A V

    2014-01-01

    Here we briefly present some design approaches for a multifrequency 96-antenna radioheliograph. The array antenna configuration, transmission lines and digital receivers are the main focus of this work. The radioheliograph is a T-shaped centrally-condensed radiointerferometer operating at the frequency range 4-8~GHz. The justification for the choice of such a configuration is discussed. The antenna signals are transmitted to a workroom by analog optical links. The dynamic range and phase errors of the microwave-over-optical signal are considered. The signals after downconverting are processed by the digital receivers for delay tracking and fringe stopping. The required delay tracking step and data rates are considered. Two 3-bit data streams (I and Q) are transmitted to a correlator with the transceivers embedded in FPGA (Field Programmed Gate Array) chips and with PCI Express cables.

  5. Electromagnetic diagnostic techniques for hypervelocity projectile detection, velocity measurement, and size characterization: Theoretical concept and first experimental test

    International Nuclear Information System (INIS)

    A new measurement technique is suggested to augment the characterization and understanding of hypervelocity projectiles before impact. The electromagnetic technique utilizes magnetic diffusion principles to detect particles, measure velocity, and indicate relative particle dimensions. It is particularly suited for detection of small particles that may be difficult to track utilizing current characterization methods, such as high-speed video or flash radiography but can be readily used for large particle detection, where particle spacing or location is not practical for other measurement systems. In this work, particles down to 2 mm in diameter have been characterized while focusing on confining the detection signal to enable multi-particle characterization with limited particle-to-particle spacing. The focus of the paper is on the theoretical concept and the analysis of its applicability based on analytical and numerical calculation. First proof-of-principle experimental tests serve to further validate the method. Some potential applications are the characterization of particles from a shaped-charge jet after its break-up and investigating debris in impact experiments to test theoretical models for the distribution of particles size, number, and velocity

  6. Electromagnetic diagnostic techniques for hypervelocity projectile detection, velocity measurement, and size characterization: Theoretical concept and first experimental test

    Science.gov (United States)

    Uhlig, W. Casey; Heine, Andreas

    2015-11-01

    A new measurement technique is suggested to augment the characterization and understanding of hypervelocity projectiles before impact. The electromagnetic technique utilizes magnetic diffusion principles to detect particles, measure velocity, and indicate relative particle dimensions. It is particularly suited for detection of small particles that may be difficult to track utilizing current characterization methods, such as high-speed video or flash radiography but can be readily used for large particle detection, where particle spacing or location is not practical for other measurement systems. In this work, particles down to 2 mm in diameter have been characterized while focusing on confining the detection signal to enable multi-particle characterization with limited particle-to-particle spacing. The focus of the paper is on the theoretical concept and the analysis of its applicability based on analytical and numerical calculation. First proof-of-principle experimental tests serve to further validate the method. Some potential applications are the characterization of particles from a shaped-charge jet after its break-up and investigating debris in impact experiments to test theoretical models for the distribution of particles size, number, and velocity.

  7. 2D and 3D optical diagnostic techniques applied to Madonna dei Fusi by Leonardo da Vinci

    Science.gov (United States)

    Fontana, R.; Gambino, M. C.; Greco, M.; Marras, L.; Materazzi, M.; Pampaloni, E.; Pelagotti, A.; Pezzati, L.; Poggi, P.; Sanapo, C.

    2005-06-01

    3D measurement and modelling have been traditionally applied to statues, buildings, archeological sites or similar large structures, but rarely to paintings. Recently, however, 3D measurements have been performed successfully also on easel paintings, allowing to detect and document the painting's surface. We used 3D models to integrate the results of various 2D imaging techniques on a common reference frame. These applications show how the 3D shape information, complemented with 2D colour maps as well as with other types of sensory data, provide the most interesting information. The 3D data acquisition was carried out by means of two devices: a high-resolution laser micro-profilometer, composed of a commercial distance meter mounted on a scanning device, and a laser-line scanner. The 2D data acquisitions were carried out using a scanning device for simultaneous RGB colour imaging and IR reflectography, and a UV fluorescence multispectral image acquisition system. We present here the results of the techniques described, applied to the analysis of an important painting of the Italian Reinassance: `Madonna dei Fusi', attributed to Leonardo da Vinci.

  8. Backfire antennas with dipole elements

    DEFF Research Database (Denmark)

    Nielsen, Erik Dragø; Pontoppidan, Knud

    1970-01-01

    A method is set up for a theoretical investigation of arbitrary backfire antennas based upon dipole structures. The mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating...... the surface current distribution on the reflector plate. Numerical results obtained for Yagi backfire antennas and short-backfire antennas using this theory are compared with experimental results....

  9. Galileo satellite antenna modeling

    Science.gov (United States)

    Steigenberger, Peter; Dach, Rolf; Prange, Lars; Montenbruck, Oliver

    2015-04-01

    The space segment of the European satellite navigation system Galileo currently consists of six satellites. Four of them belong to the first generation of In-Orbit Validation (IOV) satellites whereas the other two are Full Operational Capability (FOC) satellites. High-precision geodetic applications require detailed knowledge about the actual phase center of the satellite and receiver antenna. The deviation of this actual phase center from a well-defined reference point is described by phase center offsets (PCOs) and phase center variations (PCVs). Unfortunately, no public information is available about the Galileo satellite antenna PCOs and PCVs, neither for the IOV, nor the FOC satellites. Therefore, conventional values for the IOV satellite antenna PCOs have been adopted for the Multi-GNSS experiment (MGEX) of the International GNSS Service (IGS). The effect of the PCVs is currently neglected and no PCOs for the FOC satellites are available yet. To overcome this deficiency in GNSS observation modeling, satellite antenna PCOs and PCVs are estimated for the Galileo IOV satellites based on global GNSS tracking data of the MGEX network and additional stations of the legacy IGS network. Two completely independent solutions are computed with the Bernese and Napeos software packages. The PCO and PCV values of the individual satellites are analyzed and the availability of two different solutions allows for an accuracy assessment. The FOC satellites are built by a different manufacturer and are also equipped with another type of antenna panel compared to the IOV satellites. Signal transmission of the first FOC satellite has started in December 2014 and activation of the second satellite is expected for early 2015. Based on the available observations PCO estimates and, optionally PCVs of the FOC satellites will be presented as well. Finally, the impact of the new antenna model on the precision and accuracy of the Galileo orbit determination is analyzed.

  10. Printed MIMO antenna engineering

    CERN Document Server

    Sharawi, Mohammad S

    2014-01-01

    Wireless communications has made a huge leap during the past two decades. The multiple-input-multiple-output (MIMO) technology was proposed in the 1990's as a viable solution that can overcome the data rate limit experienced by single-input-single-output (SISO) systems. This resource is focused on printed MIMO antenna system design. Printed antennas are widely used in mobile and handheld terminals due to their conformity with the device, low cost, good integration within the device elements and mechanical parts, as well as ease of fabrication.A perfect design companion for practicing engineers

  11. Antennas fundamentals, design, measurement

    CERN Document Server

    Long, Maurice

    2009-01-01

    This comprehensive revision (3rd Edition) is a senior undergraduate or first-year graduate level textbook on antenna fundamentals, design, performance analysis, and measurements. In addition to its use as a formal course textbook, the book's pragmatic style and emphasis on the fundamentals make it especially useful to engineering professionals who need to grasp the essence of the subject quickly but without being mired in unnecessary detail. This new edition was prepared for a first year graduate course at Southern Polytechnic State University in Georgia. It provides broad coverage of antenna

  12. The Antennae Galaxies

    OpenAIRE

    Karl, Simon

    2012-01-01

    The Antennae galaxies (NGC 4038/39) are the nearest and best-studied major merger of two gas-rich spirals in the local Universe. They are named after the characteristic pair of tidal tails that protrude out of their main galactic disks. Due to their proximity the Antennae are extremely well sampled by modern high-resolution observations over an enormous wavelength range, from radio to X-ray. This allows for a comprehensive multiwavelength approach to the present-day morpholo...

  13. DSN Microwave Antenna Holography

    Science.gov (United States)

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

    1984-01-01

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

  14. Hyperbolic thermal antenna

    CERN Document Server

    Barbillon, Grégory; Biehs, Svend-Age; Ben-Abdallah, Philippe

    2016-01-01

    A thermal antenna is an electromagnetic source which emits in its surrounding, a spatially coherent field in the infrared frequency range. Usually, its emission pattern changes with the wavelength so that the heat flux it radiates is weakly directive. Here, we show that a class of hyperbolic materials, possesses a Brewster angle which is weakly dependent on the wavelength, so that they can radiate like a true thermal antenna with a highly directional heat flux. The realization of these sources could open a new avenue in the field of thermal management in far-field regime.

  15. Antennas on circular cylinders

    DEFF Research Database (Denmark)

    Knudsen, H. L.

    1959-01-01

    antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...... cylindrical surfaces have the sane characteristic constants and different constants are treated separately. Extensive numerical computations of the field radiated from the slot antennas described here are being carried out, but no numerical results are yet available...

  16. Wireless Distributed Antenna MIMO

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to system applications of multicore optical fibers. One embodiment relates to a base transceiver station for a wireless telecommunication system comprising a plurality of antenna units arranged in a MIMO configuration and adapted for transmission and/or reception of...... radio-frequency signals, an optical transmitter in the form of an electro-optic conversion unit for each of said plurality of antenna units, each electro-optic conversion unit adapted for converting an RF signal into an optical signal, a plurality of a single core optical fibers for guiding the optical...

  17. Non-standard antennas

    CERN Document Server

    Le Chevalier, Francois; Staraj, Robert

    2013-01-01

    This book aims at describing the wide variety of new technologies and concepts of non-standard antenna systems - reconfigurable, integrated, terahertz, deformable, ultra-wideband, using metamaterials, or MEMS,  etc, and how they open the way to a wide range of applications, from personal security and communications to multifunction radars and towed sonars, or satellite navigation systems, with space-time diversity on transmit and receive. A reference book for designers  in this lively scientific community linking antenna experts and signal processing engineers.

  18. Antenna Systems for NUTS

    OpenAIRE

    Marholm, Sigvald

    2012-01-01

    NTNU is aiming to build and launch a small student satellite compliant with thedouble CubeSat standard, by 2014. The NTNU Test Satellite (NUTS) will carrytwo radio tranceivers and a beacon transmitter, all located in the VHF and UHFamateur bands. The goal of this thesis was to build the whole antenna systems forthe spacecraft.Turnstile antennas were chosen both for UHF and VHF, since they yield thehighest received signal strength on ground throughout the whole pass of the satel-lite. In order...

  19. Square Planar Monopole Antenna

    OpenAIRE

    Ammann, Max

    1999-01-01

    A planar monopole may be realised by replacing the wire element of a conventional monopole with a planar element. In this case, the planar element which is square, is located above a groundplane and fed using an SMA connector as illustrated. The square monopole has a simple geometry and a smaller bandwidth compared to the circular-disc monopole. However, it is still a broadband antenna with a typical impedance bandwidth of 75 % at S band. This broadband antenna shows a constant radiation patt...

  20. A century of antenna development

    Science.gov (United States)

    Olver, A. D.

    The paper describes a century of antenna development as part of a century of radio communications. This historical review examines, chronologically, the pre-Hertz period, Hertz antennas, the microwave optics period, the Marconi era, short waves, theoretical design before and after computers, and radar. Consideration is also given to mobile antennas, microwave comunications, radio astronomy, and satellite comunications.

  1. China's Largest Radio Antenna System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ After three-and-half-year efforts, the National Astronomical Observatories at CAS (NAOC) has constructed two arrays of radio antennae: a 50m antenna at Miyun Station in Beijing and a 40m antenna in Kunming, capital of southwest China's Yunnan Province.

  2. Cardiovascular magnetic resonance of myocardial edema using a short inversion time inversion recovery (STIR black-blood technique: Diagnostic accuracy of visual and semi-quantitative assessment

    Directory of Open Access Journals (Sweden)

    h-Ici Darach O

    2012-03-01

    Full Text Available Abstract Background The short inversion time inversion recovery (STIR black-blood technique has been used to visualize myocardial edema, and thus to differentiate acute from chronic myocardial lesions. However, some cardiovascular magnetic resonance (CMR groups have reported variable image quality, and hence the diagnostic value of STIR in routine clinical practice has been put into question. The aim of our study was to analyze image quality and diagnostic performance of STIR using a set of pulse sequence parameters dedicated to edema detection, and to discuss possible factors that influence image quality. We hypothesized that STIR imaging is an accurate and robust way of detecting myocardial edema in non-selected patients with acute myocardial infarction. Methods Forty-six consecutive patients with acute myocardial infarction underwent CMR (day 4.5, +/- 1.6 including STIR for the assessment of myocardial edema and late gadolinium enhancement (LGE for quantification of myocardial necrosis. Thirty of these patients underwent a follow-up CMR at approximately six months (195 +/- 39 days. Both STIR and LGE images were evaluated separately on a segmental basis for image quality as well as for presence and extent of myocardial hyper-intensity, with both visual and semi-quantitative (threshold-based analysis. LGE was used as a reference standard for localization and extent of myocardial necrosis (acute or scar (chronic. Results Image quality of STIR images was rated as diagnostic in 99.5% of cases. At the acute stage, the sensitivity and specificity of STIR to detect infarcted segments on visual assessment was 95% and 78% respectively, and on semi-quantitative assessment was 99% and 83%, respectively. STIR differentiated acutely from chronically infarcted segments with a sensitivity of 95% by both methods and with a specificity of 99% by visual assessment and 97% by semi-quantitative assessment. The extent of hyper-intense areas on acute STIR images

  3. A Transient UWB Antenna Array Used with Complex Impedance Surfaces

    Directory of Open Access Journals (Sweden)

    M. Brishoual

    2010-01-01

    Full Text Available The conception of a novel Ultra-Wideband (UWB antenna array, designed especially for transient radar applications through the frequency band (300 MHz–3 GHz, is proposed in this paper. For these applications, the elementary antenna must be compact and nondispersive, and the array must be able to steer in two dimensions. The geometry of the elementary antenna and its radiation characteristics are presented. The array beam steering is analyzed and a technique making the increase of the transient front-to-back ratio possible is described.

  4. A Wideband Single Fed L Slot Circularly Polarized Antenna

    OpenAIRE

    Nisha; Meenakshi saini

    2014-01-01

    A single-fed circularly polarized (CP) patch antenna is designed and built using L-slot loaded patch technique. The antenna is designed on a high dielectric constant (εr = 10.02) substrate which achieves a reasonable bandwidth and axial ratio bandwidth with respect to a U slot antenna. At the operating frequency of 1.575 GHz with the size of the patch is 25mm X 25mm, while ground plane of 60mm X 60mm and the thickness of the substrate is 9.12mm. Bandwidth is enhanced to 18.42%...

  5. Comparison of diagnostic techniques for the detection and differentiation of Cherry leaf roll virus strains for quarantine purposes.

    Science.gov (United States)

    Lebas, B S M; Veerakone, S; Liefting, L W; Tang, J; Perez-Egusquiza, Z; von Bargen, S; Ward, L

    2016-08-01

    Some strains of Cherry leaf roll virus (CLRV) are considered as quarantine pests in New Zealand. CLRV was detected in seven plant host species: Actinidia chinensis, Hydrangea macrophylla, Malus domestica, Plantago major, Ribes rubrum, Rubus idaeus and Rumex sp. collected from New Zealand between 2005 and 2012. Biological, serological and molecular techniques were compared for the detection and differentiation of CLRV isolates. The biological analysis revealed differences in symptomatology and disease severity among the isolates. The five isolates tested by ELISA were serologically related to each other using polyclonal antisera with only one out of four commercially-available antisera successfully detecting all of them. The phylogenetic analysis of sequences obtained from parts of the coat protein, polymerase and 3'-untranslated regions revealed that the New Zealand CLRV isolates clustered into two closely related but distinct phylogenetic groups with some isolates grouping differently depending on the gene studied. The New Zealand CLRV isolates were clearly distinct to overseas isolates found in phylogenetic groups A, D and E. The conventional RT-PCR using primers targeting the CLRV coat protein coding region is recommended for determining sequence differences between strains. These findings will be useful in making regulatory decisions with regard to the testing requirements and the CLRV strains to be regulated in New Zealand. PMID:27129669

  6. MEMS Tunable Antennas

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Morris, Art; Pedersen, Gert Frølund

    2014-01-01

    Addressing low frequency bands is challenging on small platforms. Tunability is a promising solution to cover the bandwidth required for 4G mobile communication. The work presents two designs and shows that for comparable efficiency and bandwidth, the tunable antenna occupies half the volume requ...

  7. 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...

  8. Frequency selective lens antenna

    OpenAIRE

    Thornton, J.; Haines, P.

    2007-01-01

    A variant of the hemispherical microwave lens antenna is reported where the ground plane region is modified through use of a frequency selective surface. This allows discrimination of frequencies by two closely spaced primary feeds. A scale model is reported operating at 12 and 30 GHz.

  9. Community Antenna Television (CATV).

    Science.gov (United States)

    Federal Communications Commission, Washington, DC.

    The number of households hooked up to cable television or community antenna television (CATV) is expanding rapidly, and Federal Communications Commission (FCC) has been developing regulations since 1962 to guide the growth of the industry. By 1965 the FCC had claimed jurisdiction over all CATV systems in the U. S. This jurisdiction was challenged…

  10. Hybrid Deployable Foam Antennas and Reflectors

    Science.gov (United States)

    Rivellini, Tommaso; Willis, Paul; Hodges, Richard; Spitz, Suzanne

    2006-01-01

    small volume - typically to 1/20 of its full size in one dimension. 4) At a temperature above its glass-transition temperature (T(sub g)), the foam strongly damps vibrations. Even at a temperature below T(sub g), the damping should exceed that of other materials. 5) In its macroscopic mechanical properties, an open-cell foam is isotropic. This isotropy facilitates computational modeling of antenna structures. 6) Through chemical formulation, the T(sub g) of an open-cell polyurethane foam can be set at a desired value between about - 100 and about 0 C. Depending on the application, it may or may not be necessary to rigidify a foam structure after deployment. If rigidification is necessary, then the T(sub g) of the foam can be tailored to exceed the temperature of the deployment environment, in conjunction with providing a heater to elasticize the foam for deployment. Once deployed, the foam would become rigidified by cooling to below T(sub g). 7) Techniques for molding or machining polymeric foams (especially including open-cell polyurethane foams) to desired sizes and shapes are well developed.

  11. Evolutionary optimization of optical antennas

    CERN Document Server

    Feichtner, Thorsten; Kiunke, Markus; Hecht, Bert

    2012-01-01

    The design of nano-antennas is so far mainly inspired by radio-frequency technology. However, material properties and experimental settings need to be reconsidered at optical frequencies, which entails the need for alternative optimal antenna designs. Here a checkerboard-type, initially random array of gold cubes is subjected to evolutionary optimization. To illustrate the power of the approach we demonstrate that by optimizing the near-field intensity enhancement the evolutionary algorithm finds a new antenna geometry, essentially a split-ring/two-wire antenna hybrid which surpasses by far the performance of a conventional gap antenna by shifting the n=1 split-ring resonance into the optical regime.

  12. Antenna theory analysis and design

    CERN Document Server

    Balanis, Constantine A

    2005-01-01

    The discipline of antenna theory has experienced vast technological changes. In response, Constantine Balanis has updated his classic text, Antenna Theory, offering the most recent look at all the necessary topics. New material includes smart antennas and fractal antennas, along with the latest applications in wireless communications. Multimedia material on an accompanying CD presents PowerPoint viewgraphs of lecture notes, interactive review questions, Java animations and applets, and MATLAB features. Like the previous editions, Antenna Theory, Third Edition meets the needs of e

  13. An ion thruster internal discharge chamber electrostatic probe diagnostic technique using a high-speed probe positioning system.

    Science.gov (United States)

    Herman, Daniel A; Gallimore, Alec D

    2008-01-01

    Extensive resources have been allocated to diagnose and minimize lifetime-limiting factors in gridded ion thrusters. While most of this effort has focused on grid erosion, results from wear tests indicate that discharge cathode erosion may also play an important role in limiting the lifetime of ring-cusp ion thrusters proposed for future large flagship missions. The detailed characterization of the near-cathode discharge plasma is essential for mitigating discharge cathode erosion. However, severe difficulty is encountered when attempting to measure internal discharge plasma parameters during thruster operation with conventional probing techniques. These difficulties stem from the high-voltage, high-density discharge cathode plume, which is a hostile environment for probes. A method for interrogating the discharge chamber plasma of a working ion thruster over a two-dimensional grid is demonstrated. The high-speed axial reciprocating probe positioning system is used to minimize thruster perturbation during probe insertion and to reduce heating of the probe. Electrostatic probe measurements from a symmetric double Langmuir probe are presented over a two-dimensional spatial array in the near-discharge cathode assembly region of a 30-cm-diameter ring-cusp ion thruster. Electron temperatures, 2-5 eV, and number density contours, with a maximum of 8 x 10(12) cm(-3) on centerline, are measured. These data provide detailed electron temperature and number density contours which, when combined with plasma potential measurements, may shed light on discharge cathode erosion processes and the effect of thruster operating conditions on erosion rates. PMID:18248026

  14. An ion thruster internal discharge chamber electrostatic probe diagnostic technique using a high-speed probe positioning system

    International Nuclear Information System (INIS)

    Extensive resources have been allocated to diagnose and minimize lifetime-limiting factors in gridded ion thrusters. While most of this effort has focused on grid erosion, results from wear tests indicate that discharge cathode erosion may also play an important role in limiting the lifetime of ring-cusp ion thrusters proposed for future large flagship missions. The detailed characterization of the near-cathode discharge plasma is essential for mitigating discharge cathode erosion. However, severe difficulty is encountered when attempting to measure internal discharge plasma parameters during thruster operation with conventional probing techniques. These difficulties stem from the high-voltage, high-density discharge cathode plume, which is a hostile environment for probes. A method for interrogating the discharge chamber plasma of a working ion thruster over a two-dimensional grid is demonstrated. The high-speed axial reciprocating probe positioning system is used to minimize thruster perturbation during probe insertion and to reduce heating of the probe. Electrostatic probe measurements from a symmetric double Langmuir probe are presented over a two-dimensional spatial array in the near-discharge cathode assembly region of a 30-cm-diameter ring-cusp ion thruster. Electron temperatures, 2-5 eV, and number density contours, with a maximum of 8x1012 cm-3 on centerline, are measured. These data provide detailed electron temperature and number density contours which, when combined with plasma potential measurements, may shed light on discharge cathode erosion processes and the effect of thruster operating conditions on erosion rates

  15. An investigation into the Gustafsson limit for small planar antennas using optimisation

    CERN Document Server

    Shahpari, Morteza; Lewis, Andrew

    2013-01-01

    The fundamental limit for small antennas provides a guide to the effectiveness of designs. Gustafsson et al, Yaghjian et al, and Mohammadpour-Aghdam et al independently deduced a variation of the Chu-Harrington limit for planar antennas in different forms. Using a multi-parameter optimisation technique based on the ant colony algorithm, planar, meander dipole antenna designs were selected on the basis of lowest resonant frequency and maximum radiation efficiency. The optimal antenna designs across the spectrum from 570 to 1750 MHz occupying an area of $56mm \\times 25mm$ were compared with these limits calculated using the polarizability tensor. The results were compared with Sievenpiper's comparison of published planar antenna properties. The optimised antennas have greater than 90% polarizability compared to the containing conductive box in the range $0.3antennas is less than 50%, and resu...

  16. Lambda/4 resonance of an optical monopole antenna probed by single molecule fluorescence.

    Science.gov (United States)

    Taminiau, Tim H; Moerland, Robert J; Segerink, Frans B; Kuipers, Laurens; van Hulst, Niek F

    2007-01-01

    We present a resonant optical nanoantenna positioned at the end of a metal-coated glass fiber near-field probe. Antenna resonances, excitation conditions, and field localization are directly probed in the near field by single fluorescent molecules and compared to finite integration technique simulations. It is shown that the antenna is equivalent to its radio frequency analogue, the monopole antenna. For the right antenna length and local excitation conditions, antenna resonances occur that lead to an enhanced localized field near the antenna apex. Direct mapping of this field with single fluorescent molecules reveals a spatial localization of 25 nm, demonstrating the importance of such antennas for nanometer resolution optical microscopy. PMID:17212435

  17. MIMO communications within the HF band using compact antenna arrays.

    OpenAIRE

    Gunashekar, S.D.; Warrington, E. M.; Feeney, S. M.; Salous, S.; Abbasi, N.M.

    2010-01-01

    Measurements have been made over a 255 km radio path between Durham and Leicester in the UK in order to investigate the potential applicability of multiple input multiple output (MIMO) techniques to communications within the HF band. This paper describes the results from experiments in which compact heterogeneous antenna arrays have been employed. The results of these experiments indicate that traditional spaced HF antenna arrays can be replaced by compact, active, heterogeneous arrays in ord...

  18. A Novel Structure of Multilayer SIW Filter and Patch Antenna

    OpenAIRE

    Zahriladha Zakaria; Sam Weng Yik; Mohamad Zoinol Abidin Abd Aziz; Mohamad Ariffin Mutalib; Nor Zaidi Haron

    2013-01-01

    This paper presents the investigation based upon the resonant circuit approach to distinguish in between the microwave filter and antenna from the equivalent circuit to physical layout where this system is used to reduce the overall volume of RF front-end subsystem especially in wireless communication systems. The physical layouts of the Substrate Integrated Waveguide (SIW) filter and microstrip patch antenna based on single-mode is established based on multilayer technique. This study focuse...

  19. A Rectangular Planar Spiral Antenna for GIS Partial Discharge Detection

    OpenAIRE

    Xiaoxing Zhang; Yefei Han; Wei Li; Xuetao Duan

    2014-01-01

    A rectangular planar spiral antenna sensor was designed for detecting the partial discharge in gas insulation substations (GIS). It can expediently receive electromagnetic waves leaked from basin-type insulators and can effectively suppress low frequency electromagnetic interference from the surrounding environment. Certain effective techniques such as rectangular spiral structure, bow-tie loading, and back cavity structure optimization during the antenna design process can miniaturize antenn...

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

    OpenAIRE

    Marwaha, S.; MARWAHA A.; MAINI SURITA

    2012-01-01

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

  1. Integration of Antennas and Solar Cells for Autonomous Communication Systems

    OpenAIRE

    Roo Ons, Maria Jose, (Thesis)

    2010-01-01

    Solar energy is becoming an attractive alternative for powering autonomous communication systems. These devices often involve the use of separate photovoltaics and antennas, which demand a compromise in the utilization of the limited space available. This thesis deals with the design, analysis, fabrication and validation of different techniques for the integration of antennas and solar cells in a single multifunctional device. Four different photovoltaic technologies are considered within thi...

  2. Ultra-Wideband Design of the Wire Conical Antenna

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; HE Qing-qiang

    2005-01-01

    Using the wire construction technique, a conical monopole antenna is fabricated. With the method of moments, the dependences of the voltage standing wave ratio (VSWR) on the number of the trapezoid wire elements, conical angles, wire radius, etc. are investigated. The calculation and the experiment show that the designed wire conical antenna has the ultra-wideband property and can be used for the engineering.

  3. Microstrip Yagi array antenna for mobile satellite vehicle application

    Science.gov (United States)

    Huang, John; Densmore, Arthur C.

    1991-01-01

    A novel antenna structure formed by combining the Yagi-Uda array concept and the microstrip radiator technique is discussed. This antenna, called the microstrip Yagi array, has been developed for the mobile satellite (MSAT) system as a low-profile, low-cost, and mechanically steered medium-gain land-vehicle antenna. With the antenna's active patches (driven elements) and parasitic patches (reflector and director elements) located on the same horizontal plane, the main beam of the array can be tilted, by the effect of mutual coupling, in the elevation direction providing optimal coverage for users in the continental United States. Because the parasitic patches are not connected to any of the lossy RF power distributing circuit the antenna is an efficient radiating system. With the complete monopulse beamforming and power distributing circuits etched on a single thin stripline board underneath the microstrip Yagi array, the overall L-band antenna system has achieved a very low profile for vehicle's rooftop mounting, as well as a low manufacturing cost. Experimental results demonstrate the performance of this antenna.

  4. A DOUBLE E SHAPED MICROSTRIP PATCH ANTENNA FOR MULTIBAND APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Pristin K Mathew

    2014-06-01

    Full Text Available This paper presents a dual band Compact double E shaped Microstrip Patch antenna with enhanced gain for Worldwide Interoperability for Microwave Access (WI-MAX, Universal Mobile Telecommunication Systems (UMTS and Satellite applications. The modified E shaped patch antenna is designed using CADFEKO and the results of return loss, Voltage Standing Wave Ratio (VSWR, gain of the proposed antenna are compared with a conventional E shaped patch antenna. The results show that the double E shaped wideband patch antenna has an impedance bandwidth of 10.7 % with a return loss of -13.6dB, -12.4 dB, -12.1dB and -14.2dB at resonant frequencies of 1.96 GHz, 3.62 GHz, 5.76 GHz and 6.82 GHz, whereas a conventional E shaped patch antenna operates at 2.5 GHz, 3.4 GHz and 5.5 GHz with a return loss of -16 dB each and impedance bandwidth of 10.6 %. Both the antennas uses Coaxial Probe feeding technique and Flame Retardant 4 (FR-4 as the substrate material with a thickness of 2.87 mm. A parametric study has been done so as to understand the effect of each parameter to obtain a better performance and optimised results.

  5. Final tests and performances verification of the European ALMA antennas

    Science.gov (United States)

    Marchiori, Gianpietro; Rampini, Francesco

    2012-09-01

    The Atacama Large Millimeter Array (ALMA) is under erection in Northern Chile. The array consists of a large number (up to 64) of 12 m diameter antennas and a number of smaller antennas, to be operated on the Chajnantor plateau at 5000 m altitude. The antennas will operate up to 950 GHz so that their mechanical performances, in terms of surface accuracy, pointing precision and dimensional stability, are very tight. The AEM consortium constituted by Thales Alenia Space France, Thales Alenia Space Italy, European Industrial Engineering (EIE GROUP), and MT Mechatronics is assembling and testing the 25 antennas. As of today, the first set of antennas have been delivered to ALMA for science. During the test phase with ESO and ALMA, the European antennas have shown excellent performances ensuring the specification requirements widely. The purpose of this paper is to present the different results obtained during the test campaign: surface accuracy, pointing error, fast motion capability and residual delay. Very important was also the test phases that led to the validation of the FE model showing that the antenna is working with a good margin than predicted at design level thanks also to the assembly and integration techniques.

  6. Evolutionary Optimization of Quadrifilar Helical and Yagi-Uda Antennas

    Science.gov (United States)

    Lohn, Jason D.; Kraus, William F.; Linden, Derek S.; Stoica, Adrian; Clancy, Daniel (Technical Monitor)

    2002-01-01

    We present optimization results obtained for two type of antennas using evolutionary algorithms. A quadrifilar helical UHF antenna is currently flying aboard NASA's Mars Odyssey spacecraft and is due to reach final Martian orbit insertion in January, 2002. Using this antenna as a benchmark, we ran experiments employing a coevolutionary genetic algorithm to evolve a quadrifilar helical design in-situ - i.e., in the presence of a surrounding structure. Results show a 93% improvement at 400 MHz and a 48% improvement at 438 MHz in the average gain. The evolved antenna is also one-fourth the size. Yagi-Uda antennas are known to be difficult to design and optimize due to their sensitivity at high gain and the inclusion of numerous parasitic elements. Our fitness calculation allows the implicit relationship between power gain and sidelobe/backlobe loss to emerge naturally, a technique that is less complex than previous approaches. Our results include Yagi-Uda antennas that have excellent bandwidth and gain properties with very good impedance characteristics. Results exceeded previous Yagi-Uda antennas produced via evolutionary algorithms by at least 7.8% in mainlobe gain.

  7. Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors.

    Directory of Open Access Journals (Sweden)

    Mingyue Luo

    Full Text Available To evaluate the diagnostic value of multidetector CT (MDCT and its multiplanar reformation (MPR, volume rendering (VR and virtual bronchoscopy (VB postprocessing techniques for primary trachea and main bronchus tumors.Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology.Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6, tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16, extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm-56.0 mm, n = 14; no clear border with right atelectasis, n = 1, longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm-68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1, morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1 and extents (mild, n = 5; moderate, n = 7; severe, n = 19, distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10, and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density

  8. DESIGN OF HYBRID COUPLER CONNECTED SQUARE ARRAY PATCH ANTENNA FOR Wi-Fi APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. Sahaya Anselin Nisha

    2012-01-01

    Full Text Available Microstrip patch antennas being popular because of light weight, low volume, thin profile configuration which can be made conformal. Wireless communication systems applications circular polarization antenna is placing vital role. In this study we introduce a new technique to produce circular polarization. Hybrid coupler is directly connected to microstrip antenna to get circular polarization. Also gain is further increased by introducing antenna array technique. Each square in array having length of 4.6mm patch is having thickness of 0.381mm and the dielectric material used FR4. The designed antenna having high gain of 6.26dB and directivity of 5.11dB at the resonant frequency of 3.7GHz. Simulation results shows that the designed antenna characteristic is suitable for Wi-Fi applications.

  9. Omnidirectional Circularly Polarized Antennas – a Small Antenna Perspective

    OpenAIRE

    Narbudowicz, Adam; Ammann, Max

    2015-01-01

    The paper discusses recent developments and challenges in the design of small omnidirectionalcircularly-polarized (CP) antennas. Although omnidirectional CP coverage is easily achievable usingantenna arrays, it is just recently that small and low-cost antennas delivered this functionality.The paper addresses practical design problems for these antennas, not reported in previous publications.This includes selection of the omnidirectional plane relative to the ground plane and measurement chall...

  10. Numerical analysis of patch antenna as antenna array element

    OpenAIRE

    Kizimenko, V.; Bobkov, Y

    2009-01-01

    The patch antennas as antenna array element can be modeling by finite element method (programs Microwave Office, Ansoft HFSS and other). But this method need to use fast computer with memory large size. In this work the authors make an attempt to use thin wire integral equation method for patch antenna analysis. The results of modeling by proposed method are compared with the same of modeling by finite elements method and experimental results.

  11. Microsecond switchable thermal antenna

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Abdallah, Philippe, E-mail: pba@institutoptique.fr; Benisty, Henri; Besbes, Mondher [Laboratoire Charles Fabry, UMR 8501, Institut d' Optique, CNRS, Université Paris-Sud 11, 2, Avenue Augustin Fresnel, 91127 Palaiseau Cedex (France)

    2014-07-21

    We propose a thermal antenna that can be actively switched on and off at the microsecond scale by means of a phase transition of a metal-insulator material, the vanadium dioxide (VO{sub 2}). This thermal source is made of a periodically patterned tunable VO{sub 2} nanolayer, which support a surface phonon-polariton in the infrared range in their crystalline phase. Using electrodes properly registered with respect to the pattern, the VO{sub 2} phase transition can be locally triggered by ohmic heating so that the surface phonon-polariton can be diffracted by the induced grating, producing a highly directional thermal emission. Conversely, when heating less, the VO{sub 2} layers cool down below the transition temperature, the surface phonon-polariton cannot be diffracted anymore so that thermal emission is inhibited. This switchable antenna could find broad applications in the domain of active thermal coatings or in those of infrared spectroscopy and sensing.

  12. 47 CFR 80.863 - Antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna system. 80.863 Section 80.863... Antenna system. (a) An antenna system must be installed which is as nondirectional and as efficient as is... construction of the required antenna must insure operation in time of emergency. (b) If the required antenna...

  13. 47 CFR 80.866 - Spare antenna.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Spare antenna. 80.866 Section 80.866... Spare antenna. A spare transmitting antenna completely assembled for immediate erection must be provided. If the installed transmitting antenna is suspended between supports, this spare antenna must be...

  14. Analysis and design of plasma monopole antenna

    OpenAIRE

    Wei, Li; Jinghui, Qiu; Ying, Suo

    2009-01-01

    Two kinds of plasma monopole antennas are simulated and analyzed in this article. For different radius, reflection coefficient, radiation pattern and radiation efficiency of a cylindrical plasma monopole antenna are calculated respectively. According to actual situation, a conical plasma monopole antenna with different cone angle is simulated. Impedance and radiation characteristics of the plasma antenna are similar to the metal monopole antenna.

  15. Design of E-shaped Microstrip Antenna And Parameters estimation using ANN – A review

    Directory of Open Access Journals (Sweden)

    Gurdeep Singh

    2012-03-01

    Full Text Available The microstrip antenna finds applications in varied and upcoming technologies because it offers low profile, narrow bandwidth, high gain, and compact antenna element. The microstrip antenna have biggest disadvantage of narrow bandwidth and poor impedance matching. To make microstrip antenna compatible with commercial applications, the bandwidth enhancement and impedance matching of such antennas are to be done. To improve the bandwidth the L probe and U slot techniques are used, those are efficient to enhance the bandwidth. In this research, Microstrip patch antenna with coaxial feed technique is integrated. The impedance matching of antenna depends upon type and position of the feed because impedance matching of source at the feeding point of antenna is very important for efficient operation of antenna. But it is not an easy task to achieve for a simple microstrip patch antenna. To solve this problem an Artificial Neural Network (ANN model has proposed in this research. Artificial Neural Network is highly simplified model of the structure of the biological neural network to calculate the parameters by estimation.

  16. Understanding and optimizing microstrip patch antenna cross polarization radiation on element level for demanding phased array antennas in weather radar applications

    Science.gov (United States)

    Vollbracht, D.

    2015-11-01

    The antenna cross polarization suppression (CPS) is of significant importance for the accurate calculation of polarimetric weather radar moments. State-of-the-art reflector antennas fulfill these requirements, but phased array antennas are changing their CPS during the main beam shift, off-broadside direction. Since the cross polarization (x-pol) of the array pattern is affected by the x-pol element factor, the single antenna element should be designed for maximum CPS, not only at broadside, but also for the complete angular electronic scan (e-scan) range of the phased array antenna main beam positions. Different methods for reducing the x-pol radiation from microstrip patch antenna elements, available from literature sources, are discussed and summarized. The potential x-pol sources from probe fed microstrip patch antennas are investigated. Due to the lack of literature references, circular and square shaped X-Band radiators are compared in their x-pol performance and the microstrip patch antenna size variation was analyzed for improved x-pol pattern. Furthermore, the most promising technique for the reduction of x-pol radiation, namely "differential feeding with two RF signals 180° out of phase", is compared to single fed patch antennas and thoroughly investigated for phased array applications with simulation results from CST MICROWAVE STUDIO (CST MWS). A new explanation for the excellent port isolation of dual linear polarized and differential fed patch antennas is given graphically. The antenna radiation pattern from single fed and differential fed microstrip patch antennas are analyzed and the shapes of the x-pol patterns are discussed with the well-known cavity model. Moreover, two new visual based electromagnetic approaches for the explanation of the x-pol generation will be given: the field line approach and the surface current distribution approach provide new insight in understanding the generation of x-pol component in microstrip patch antenna radiation

  17. Plasma diagnostics for tokamaks and stellarators

    International Nuclear Information System (INIS)

    A collection of papers on plasma diagnostics is presented. The papers show the state of the art developments in a series of techniques: magnetic diagnostics, Edge diagnostics, Langmuir probes, Spectroscopy, Microwave and FIR diagnostics as well as Thomson Sattering. Special interest was focused on those diagnostics oriented to fluctuations measurements in the plasma

  18. Plasma diagnostics for tokamaks and stellarators

    Energy Technology Data Exchange (ETDEWEB)

    Stott, P. E.; Sanchez, J.

    1994-07-01

    A collection of papers on plasma diagnostics is presented. The papers show the state of the art developments in a series of techniques: Magnetic diagnostics, Edge diagnostics, Langmuir probes, Spectroscopy, Microwave and FIR diagnostics as well as Thomson Scattering. Special interest was focused on those diagnostics oriented to fluctuations measurements in the plasma. (Author) 451 refs.

  19. Helicopter Rotor Antenna

    Science.gov (United States)

    Pogorzelski, Ronald J.; Cable, Vaughn P.

    2001-01-01

    This effort was directed toward demonstration of the efficacy of a concept for mitigation of the rotor blade modulation problem in helicopter communications. An antenna is envisioned with radiating elements mounted on the rotor and rotating with it. The rf signals are coupled to the radio stationary with respect to the airframe via a coupler of unique design. The coupler has an rf cavity within which a mode is established and the field distribution of this mode is sampled by probes rotating with the radiating elements. In this manner the radiated pattern is "despun" with respect to the rotor. Theoretical analysis has indicated that this arrangement will be less susceptible to rotor blade modulation that would be a conventional fixed mounted antenna. A small coupler operating at S-band was designed, fabricated, and mounted on a mockup representative of a helicopter body. A small electric motor was installed to rotate the rotor portion of the coupler along with a set of radiating elements during testing. This test article was be evaluated using the JPL Mesa Antenna Measurement Facility to establish its ability to mitigate rotor blade modulation. It was found that indeed such a coupler will result in a despun pattern and that such a pattern can be effective in mitigation of rotor blade modulation.

  20. Monopole Antenna Probe for Density Measurements in Cold Plasmas

    International Nuclear Information System (INIS)

    A simple diagnostic tool for density measurements in plasma with a certain spatial resolution is proposed in this paper. It uses the emission characteristics of monopole antenna to determine the dielectic property of plasma in= 1 - fp2/f2, with the fp electron plasma frequency related to plasma density. We immersed a monopole antenna probe into plasma and introduced a microwave signal via a network analyzer. When the emitted power is maximized, the reflected power is minimized and there occurs a resonance. Since can be derived from the resonant frequency, this is actually a method to measure the absolute electron density. Validated by a comparison with the amended Langmuir double-probe method, the monopole antenna probe is valuable. In addition, it is free from the difficulties, such as fluctuation in plasma potential. (low temperature plasma)