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Sample records for antenna diagnostics technique

  1. Antenna Diagnostics using Near Field Techniques

    NARCIS (Netherlands)

    Paquay, M.H.A.

    1996-01-01

    The radiation characteristics of an antenna are fully determined by its aperture distribution. Measured Near Field data gives an impression but this is not good enough to detect small anomalies. For good antenna diagnostics, the field at the aperture plane is required. The Near Field Measurement Tec

  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

    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....... 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...

  3. Comparison of different antenna diagnostics techniques with limited far field data input

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Cappellin, Cecilia

    2015-01-01

    In this paper, three different antenna diagnostics techniques are compared for the case when the input far-field data represent only few complete cuts or a two-dimensional grid with a limited angular sector. The techniques are applied to several different antennas: a high-gain offset reflector...... and extreme near fields....

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

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Breinbjerg, Olav; Frandsen, Aksel

    2005-01-01

    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...

  5. 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 r...

  6. 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, from...... on this diagnostics technique. In order to isolate different measurement inaccuracies, the investigation is based on simulations....... data acquired during a spherical near-field measurement. From the PWE the aperture field can subsequently be calculated. While the fundamental properties of the SWE-to-PWE transformation have been reported in previous articles, we concentrate here on the influence of non-ideal measurements aspects...

  7. Multifunctional Antenna Techniques

    Science.gov (United States)

    2015-11-25

    accelerating the development of more advanced and compact radiating systems. Fig. 1 Stripline-fed spiral antenna: (top) cross-section of the stripline...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Multifunctional antennas, reconfigurable antennas, electromagnetics REPORT... Electromagnetic Analysis and Applications, (06 2013): 223. doi: 10.4236/jemaa.2013.55036 Teng-Kai Chen, Gregory H. Huff. Transmission line analysis

  8. 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

  9. Spherical near-field antenna measurements — The most accurate antenna measurement technique

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2016-01-01

    The spherical near-field antenna measurement technique combines several advantages and generally constitutes the most accurate technique for experimental characterization of radiation from antennas. This paper/presentation discusses these advantages, briefly reviews the early history and present...... status, and addresses future challenges for spherical near-field antenna measurements; in particular, from the viewpoint of the DTU-ESA Spherical Near-Field Antenna Test Facility....

  10. 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.

  11. Definition of IMR antenna test techniques

    Science.gov (United States)

    Vokurka, V. J.

    1984-09-01

    Compact antenna test ranges (CR) with two cylindrical reflectors are compared with other indoor techniques. It is shown that only CR create an electromagnetic field environment suitable for far field simulation. The reflectivity level of CR is better than that of other (indoor and outdoor) ranges. Levels as low as -70 dB are realistic; this implies that an important source of errors in pattern measurements is eliminated. The cross-polar level is relatively high for linear polarization (vertical plane only), but accurate cross-polar measurements are possible. Errors due to amplitude taper are acceptable even for antennas which occupy 60% of the CR dimension (linear). Phase characteristics are almost perfect.

  12. Full-duplex MIMO system based on antenna cancellation technique

    DEFF Research Database (Denmark)

    Foroozanfard, Ehsan; Franek, Ondrej; Tatomirescu, Alexandru

    2014-01-01

    The performance of an antenna cancellation technique for a multiple-input– multiple-output (MIMO) full-duplex system that is based on null-steering beamforming and antenna polarization diversity is investigated. A practical implementation of a symmetric antenna topology comprising three dual-pola...

  13. Innovative Techniques for Antenna Synthesis in Modern Wireless Communication Systems

    OpenAIRE

    Leonardo, Lizzi

    2011-01-01

    This thesis deals with the study and development of innovative techniques for the synthesis of antennas able to fulfill the tight requirements of modern wireless communication systems. By exploiting the advantages given by the use of geometries based on spline and fractal shapes, the aim of the proposed synthesis techniques is the design of small Ultra-Wideband (UWB) and multi-band antennas. The synthesis of UWB antennas is carried out by means of two different approaches which consider the a...

  14. An analysis technique for microstrip antennas

    Science.gov (United States)

    Agrawal, P. K.; Bailey, M. C.

    1977-01-01

    The paper presents a combined numerical and empirical approach to the analysis of microstrip antennas over a wide range of frequencies. The method involves representing the antenna by a fine wire grid immersed in a dielectric medium and then using Richmond's reaction formulation (1974) to evaluate the piecewise sinusoidal currents on the grid segments. The calculated results are then modified to account for the finite dielectric discontinuity. The method is applied to round and square microstrip antennas.

  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. Antenna Performance Improvement Techniques for Energy Harvesting: A Review Study

    Directory of Open Access Journals (Sweden)

    Raed Abdulkareem Abdulhasan

    2017-01-01

    Full Text Available The energy harvesting is defined as using energy that is available within the environment to increase the efficiency of any application. Moreover, this method is recognized as a useful way to break down the limitation of battery power for wireless devices. In this paper, several antenna designs of energy harvesting are introduced. The improved results are summarized as a 2×2 patch array antenna realizes improved efficiency by 3.9 times higher than the single patch antenna. The antenna has enhanced the bandwidth of 22.5 MHz after load two slots on the patch. The solar cell antenna is allowing harvesting energy during daylight. A couple of E-patches antennas have increased the bandwidth of 33% and the directivity up to 20 dBi. The received power can be improved by 1.2-1.4 times when using the dual port on pixel antenna. Complementary split ring resonator and substrate integrated waveguide are utilized cavity-backed feeding on a fractal patch antenna to enhance the bandwidth around 5.1%. Moreover, adding a rectifier circuit to an antenna converts the reserved RF-signal to DC power, and then duplicated the input voltage up to sum the total number of rectifier circuit stages. Therefore, the advantages and disadvantages of each antenna depend on the technique which used in design.

  17. 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.

  18. 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.

  19. Nanotechnology in Disease Diagnostic Techniques.

    Science.gov (United States)

    Savaliya, Reema; Shah, Darshini; Singh, Ragini; Kumar, Ashutosh; Shankar, Rishi; Dhawan, Alok; Singh, Sanjay

    2015-06-25

    Currently the major research highlights of bioengineering and medical technology are directed towards development of improved diagnostic techniques to screen complex diseases. Screening requirements are for the identification of the cause of illnesses, monitoring the improvement or progression of the state of diseases such as cancer, cardiovascular or neurodegenerative diseases. Nanotechnology enables the manipulation of materials at nanoscale and has shown potential to enhance sensitivity, selectivity and lower the cost of a diagnosis. The causative biomolecules (DNA, proteins) can be detected by red-shifted absorbance of gold nanoparticles or alteration in the conductance of a nanowire or nanotubes, and deflection of a micro or nano-cantilever. Several types of nanomaterials such as metals, metal-oxides and quantum dots have shown ample advantages over traditional diagnosis, intracellular labeling and visualization of target cells/tissues. Nanotechnology has also opened several avenues which could be further developed to enable enhanced visualization of tissues, cells, DNA and proteins over a point-of-care device. Protein or gene chips created using nanomaterials could be further be integrated into a convenient nano-fluidic device for better disease diagnosis.

  20. Integrated diagnostic technique for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Gofuku, Akio [Graduate School of Natural Science and Technology, Okayama University, Okayama (Japan)

    2014-12-15

    It is very important to detect and identify small anomalies and component failures for the safe operation of complex and large-scale artifacts such as nuclear power plants. Each diagnostic technique has its own advantages and limitations. These facts inspire us not only to enhance the capability of diagnostic techniques but also to integrate the results of diagnostic subsystems in order to obtain more accurate diagnostic results. The article describes the outline of four diagnostic techniques developed for the condition monitoring of the fast breeder reactor 'Monju'. The techniques are (1) estimation technique of important state variables based on a physical model of the component, (2) a state identification technique by non-linear discrimination function applying SVM (Support Vector Machine), (3) a diagnostic technique applying WT (Wavelet Transformation) to detect changes in the characteristics of measurement signals, and (4) a state identification technique effectively using past cases. In addition, a hybrid diagnostic system in which a final diagnostic result is given by integrating the results from subsystems is introduced, where two sets of values called confidence values and trust values are used. A technique to determine the trust value is investigated under the condition that the confidence value is determined by each subsystem.

  1. 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.

  2. 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 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-ESA facility...

  3. Survey of Diagnostic Techniques for Dynamic Components

    Science.gov (United States)

    2010-01-01

    sensitive to torque fluctuations (19). • NP4 deteriorates as the severity of the damage increases on multiple gear teeth (25). • Crest factor indicates...diagnostic techniques that have been developed for dynamic components such as bearings and gears . There has been a tremendous amount of research... Gears 13  3.1  Diagnostic or Signal Enhancement Techniques ............................................................14  3.2  Time Synchronous Average

  4. 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.

  5. A Diagnostic for Electric Field Measurements in the Near/Far-Field Regions of ICRF Antenna

    Science.gov (United States)

    Martin, E. H.; Caughman, J. B. O.; Isler, R. C.

    2015-11-01

    The physics mechanisms of wave heating and current drive processes in the bulk hot plasma are generally well identified. However, details of the wave-plasma interaction with a material surface in the cold plasma edge are still not fully understood. The driver behind this interaction is the time-periodic wave electric field and is referred to as the near/far-field depending on the location with respect to the antenna. Various models have been formulated to capture the near/far-field physics but have not been tested experimentally. Thus, a diagnostic capable of measuring the electric field with temporal and 3D-spatial resolution is critical for confidence in the codes used to design next generation ICRF antennas. This research is focused on the development of a laser based spectroscopic technique, Doppler-free saturation spectroscopy (DFSS), and its implementation to study near/far-field physics. Using DFSS the spectra line profile of various electronic transitions are measured and fit to a quantum mechanical model incorporating both magnetic and dynamic electric field operators. The electric field direction and magnitude are extracted from the fit. The experimental setup and planned experiments will be discussed. Additionally, initial measurements of fitted Hδ spectrum under the influence of known electric and magnetic fields will be presented.

  6. Application of adaptive antenna techniques to future commercial satellite communication

    Science.gov (United States)

    Ersoy, L.; Lee, E. A.; Matthews, E. W.

    1987-01-01

    The purpose of this contract was to identify the application of adaptive antenna technique in future operational commercial satellite communication systems and to quantify potential benefits. The contract consisted of two major subtasks. Task 1, Assessment of Future Commercial Satellite System Requirements, was generally referred to as the Adaptive section. Task 2 dealt with Pointing Error Compensation Study for a Multiple Scanning/Fixed Spot Beam Reflector Antenna System and was referred to as the reconfigurable system. Each of these tasks was further sub-divided into smaller subtasks. It should also be noted that the reconfigurable system is usually defined as an open-loop system while the adaptive system is a closed-loop system. The differences between the open- and closed-loop systems were defined. Both the adaptive and reconfigurable systems were explained and the potential applications of such systems were presented in the context of commercial communication satellite systems.

  7. Array antenna diagnostics with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... reconstruction algorithm. Considerations on the measurement sampling, the obtainable spatial resolution, and the possibility of taking full advantage of the reconstruction geometry are provided....

  8. Application aspects of advanced antenna diagnostics with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Pivnenko, Sergey

    2015-01-01

    This paper focuses on two important applications of the 3D reconstruction algorithm of the commercial software DIATOOL for antenna diagnostics. The first one is the accurate and detailed identification of array malfunctioning, thanks to the available enhanced spatial resolution of the reconstructed...

  9. Comparative diagnostic techniques for cryptosporidium infection.

    Science.gov (United States)

    Omoruyi, Beauty E; Nwodo, Uchechukwu U; Udem, Chukwuneke S; Okonkwo, Francis O

    2014-02-24

    Diarrhoea caused by Cryptosporidium is usually mild in immune competent individuals but severe in the young and those with underlying disease leading to compromised immunity. The conventional diagnosis of Cryptosporidium requires observation of the infective oocysts however, their tiny size yields indistinct results, thus limiting the effectiveness of the conventional diagnostic technique, modified Ziehl-Neelsen (ZN) differential staining. Consequent to the abovementioned limitation, ZN staining, sandwich antigen detection enzyme linked immunosorbent assay (sad-ELISA) and a direct polymerase chain reaction (PCR) assay techniques were evaluated for diagnostic efficacy. Stool samples were collected from 180 consenting adult patients attending outpatient and inpatient clinics at Victoria Hospital, Alice, Eastern Cape Province of South Africa. Subjects were stratified as; 35 HIV-positive and diarrhoeagenic, 125 HIV-negative diarrhoeagenic and 20 apparently healthy controls. Cryptosporidium incidence following diagnostic techniques were 13 (37.1%; ZN staining), 26 (74.3%; sad-ELISA) and 23 (65.7%; PCR), respectively, among HIV-positive diarrhoeagenic patients and 34 (27.2%; ZN staining), 96 (76.8%; sad-ELISA) and 89 (71.2%; PCR) among HIV-negative diarrhoeagenic patients. Sensitivity, specificity and predictive values of the diagnostic techniques' efficiency were: sensitivity: 46.2% (HIV-positive) and 32.3% (HIV-negative) against the ZN technique and 96.9% against sad-ELISA and PCR, respectively, for both HIV-positive and -negative patients; specificity was 88.9% (HIV-positive) and 96.6% (HIV-negative) against the ZN technique. Lastly, the predictive values were 92.3% (HIV-positive) and 96.9% (HIV-negative), respectively, following ZN staining. The sad-ELISA technique proved more suitable for the determination of the presence of Cryptosporidium oocysts. The high incidence of Cryptosporidium in HIV-positive subjects as compared to the HIV-negative population accentuates

  10. Comparative Diagnostic Techniques for Cryptosporidium Infection

    Directory of Open Access Journals (Sweden)

    Beauty E. Omoruyi

    2014-02-01

    Full Text Available Diarrhoea caused by Cryptosporidium is usually mild in immune competent individuals but severe in the young and those with underlying disease leading to compromised immunity. The conventional diagnosis of Cryptosporidium requires observation of the infective oocysts however, their tiny size yields indistinct results, thus limiting the effectiveness of the conventional diagnostic technique, modified Ziehl-Neelsen (ZN differential staining. Consequent to the abovementioned limitation, ZN staining, sandwich antigen detection enzyme linked immunosorbent assay (sad-ELISA and a direct polymerase chain reaction (PCR assay techniques were evaluated for diagnostic efficacy. Stool samples were collected from 180 consenting adult patients attending outpatient and inpatient clinics at Victoria Hospital, Alice, Eastern Cape Province of South Africa. Subjects were stratified as; 35 HIV-positive and diarrhoeagenic, 125 HIV-negative diarrhoeagenic and 20 apparently healthy controls. Cryptosporidium incidence following diagnostic techniques were 13 (37.1%; ZN staining, 26 (74.3%; sad-ELISA and 23 (65.7%; PCR, respectively, among HIV-positive diarrhoeagenic patients and 34 (27.2%; ZN staining, 96 (76.8%; sad-ELISA and 89 (71.2%; PCR among HIV-negative diarrhoeagenic patients. Sensitivity, specificity and predictive values of the diagnostic techniques’ efficiency were: sensitivity: 46.2% (HIV-positive and 32.3% (HIV-negative against the ZN technique and 96.9% against sad-ELISA and PCR, respectively, for both HIV-positive and -negative patients; specificity was 88.9% (HIV-positive and 96.6% (HIV-negative against the ZN technique. Lastly, the predictive values were 92.3% (HIV-positive and 96.9% (HIV-negative, respectively, following ZN staining. The sad-ELISA technique proved more suitable for the determination of the presence of Cryptosporidium oocysts. The high incidence of Cryptosporidium in HIV-positive subjects as compared to the HIV-negative population

  11. 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

    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......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...

  12. 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.

  13. 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.

  14. Source reconstruction technique for slot array antennas using the Gerchberg-Papoulis algorithm

    OpenAIRE

    Sano, Makoto; Sierra Castañer, Manuel; Salmerón Ruiz, Tamara; Hirokawa, Jiro; Ando, Makoto

    2014-01-01

    A source reconstruction technique for slot array antennas is presented. By exploiting the information about the positions and the polarizations of slots to the Gerchberg-Papoulis iterative algorithm, the field on the slots is accurately reconstructed. The proposed technique is applied to the source reconstruction of a K-band radial line slot antenna (RLSA), and the simulated and measured results are presented

  15. 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.

  16. Electronically steerable millimeter wave antenna techniques for space shuttle applications

    Science.gov (United States)

    Kummer, W. H.

    1975-01-01

    A large multi-function antenna aperture and related components are described which will perform electronic steering of one or more beams for two of the three applications envisioned: (1) communications, (2) radar, and (3) radiometry. The array consists of a 6-meter folded antenna that fits into two pallets. The communications frequencies are 20 and 30 GHz, while the radar is to operate at 13.9 GHz. Weight, prime power, and volumes are given parametrically; antenna designs, electronics configurations, and mechanical design were studied.

  17. Novel On-wafer Radiation Pattern Measurement Technique for MEMS Actuator Based Reconfigurable Patch Antennas

    Science.gov (United States)

    Simons, Rainee N.

    2002-01-01

    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.

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

    Science.gov (United States)

    Leipold, F; Furtula, V; Salewski, M; Bindslev, H; Korsholm, S B; Meo, F; Michelsen, P K; Moseev, D; Nielsen, S K; Stejner, M

    2009-09-01

    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 using gyrotrons operated at 60 GHz will meet the requirements for spatially and temporally resolved measurements of the velocity distributions of confined fast alphas in ITER by evaluating the scattered radiation (CTS signal). While a receiver antenna on the low field side of the tokamak, resolving near perpendicular (to the magnetic field) velocity components, has been enabled, an additional antenna on the high field side (HFS) would enable measurements of near parallel (to the magnetic field) velocity components. A compact design solution for the proposed mirror system on the HFS is presented. The HFS CTS antenna is located behind the blankets and views the plasma through the gap between two blanket modules. The viewing gap has been modified to dimensions 30x500 mm(2) to optimize the CTS signal. A 1:1 mock-up of the HFS mirror system was built. Measurements of the beam characteristics for millimeter-waves at 60 GHz used in the mock-up agree well with the modeling.

  19. 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...

  20. 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.

  1. Characterization of small antennas for hearing aids by several measurement techniques

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Zhang, Jiaying; Khatun, Afroza;

    2010-01-01

    Characteristics of electrically small loop antennas were measured by different techniques and the results were compared in-between. The techniques employed were: a single-probe spherical near-field technique, a multi-probe spherical near-field technique, a reverberation chamber, and a Wheeler cap...

  2. VLBI collimation tower technique for time-delay studies of a large ground station communications antenna

    Science.gov (United States)

    Otoshi, T. Y.; Young, L. E.; Rusch, W. V. T.

    1983-01-01

    A need for an accurate but inexpensive method for measuring and evaluating time delays of large ground antennas for VLBI applications motivated the development of the collimation tower technique. Supporting analytical work which was performed primarily to verify time delay measurement results obtained for a large antenna when the transmitter was at a collimation distance of 1/25 of the usual far field criterion is discussed. Comparisons of theoretical and experimental results are also given.

  3. Antenna pointing system for satellite tracking based on Kalman filtering and model predictive control techniques

    Science.gov (United States)

    Souza, André L. G.; Ishihara, João Y.; Ferreira, Henrique C.; Borges, Renato A.; Borges, Geovany A.

    2016-12-01

    The present work proposes a new approach for an antenna pointing system for satellite tracking. Such a system uses the received signal to estimate the beam pointing deviation and then adjusts the antenna pointing. The present work has two contributions. First, the estimation is performed by a Kalman filter based conical scan technique. This technique uses the Kalman filter avoiding the batch estimator and applies a mathematical manipulation avoiding the linearization approximations. Secondly, a control technique based on the model predictive control together with an explicit state feedback solution are obtained in order to reduce the computational burden. Numerical examples illustrate the results.

  4. Development of novel fuel ion ratio diagnostic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Korsholm, S. B.; Stejner, M.; Bindslev, H.; Furtula, V.; Leipold, F.; Meo, F.; Michelsen, P. K.; Moseev, D.; Nielsen, S. K.; Salewski, M. [Association EURATOM-Risoe DTU, 4000 Roskilde (Denmark); Conroy, S.; Ericsson, G. [Association EURATOM-VR, Uppsala University, 75120 Uppsala (Sweden); Gorini, G.; Tardocchi, M. [Association EURATOM-ENEA CNR, 20125 Milano (Italy); Hellermann, M. von; Lischtschenko, O.; Delabie, E. [Association EURATOM-FOM, 3430 BE Nieuwegein (Netherlands); Jaspers, R. J. E. [Department of Applied Physics, Fusion Group, Eindhoven University of Technology, 5612 AZ Eindhoven (Netherlands)

    2010-10-15

    To overcome the challenge of measuring the fuel ion ratio in the core ({rho}<0.3) of ITER, a coordinated effort aiming at developing diagnostic techniques has been initiated. The investigated techniques are novel uses or further development of existing methods such as charge exchange recombination spectrometry, neutron spectrometry, and collective Thomson scattering. An overview of the work on the three diagnostic techniques is presented.

  5. 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), wh...

  6. 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....

  7. Basic antenna transmitting characteristics using an extrapolation range measurement technique at a millimeter-wave band at NMIJ/AIST.

    Science.gov (United States)

    Yamamoto, Tetsuya

    2007-06-01

    A novel test fixture operating at a millimeter-wave band using an extrapolation range measurement technique was developed at the National Metrology Institute of Japan (NMIJ). Here I describe the measurement system using a Q-band test fixture. I measured the relative insertion loss as a function of antenna separation distance and observed the effects of multiple reflections between the antennas. I also evaluated the antenna gain at 33 GHz using the extrapolation technique.

  8. 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.

  9. Multihop relaying and multiple antenna techniques: performance trade-offs in cellular systems

    Directory of Open Access Journals (Sweden)

    Jacobson Kevin

    2011-01-01

    Full Text Available Abstract Two very important and active areas of wireless research are multihop relaying and multiple antenna techniques. Wireless multihop relaying can increase the aggregate network data capacity and improve coverage of cellular systems by reducing path loss, mitigating shadowing, and enabling spatial reuse. In particular, multihop relaying can improve the throughput for mobiles suffering from poor signal to interference and noise ratio at the edge of a cell and reduce cell size to increase spectral efficiency. On the other hand, multiple antenna techniques can take advantage of scattering in the wireless channel to achieve higher capacity on individual links. Multiple antennas can provide impressive capacity gains, but the greatest gains occur in high scattering environments with high signal to interference and noise ratio, which are not typical characteristics of cellular systems. Emerging standards for fourth generation cellular systems include both multihop relaying and multiple antenna techniques, so it is necessary to study how these two work jointly in a realistic cellular system. In this paper, we look at the joint application of these two techniques in a cellular system and analyze the fundamental tradeoff between them. In order to obtain meaningful results, system performance is evaluated using realistic propagation models.

  10. Comparative Analysis of Linear and Nonlinear Pattern Synthesis of Hemispherical Antenna Array Using Adaptive Evolutionary Techniques

    Directory of Open Access Journals (Sweden)

    K. R. Subhashini

    2014-01-01

    synthesis is termed as the variation in the element excitation amplitude and nonlinear synthesis is process of variation in element angular position. Both ADE and AFA are a high-performance stochastic evolutionary algorithm used to solve N-dimensional problems. These methods are used to determine a set of parameters of antenna elements that provide the desired radiation pattern. The effectiveness of the algorithms for the design of conformal antenna array is shown by means of numerical results. Comparison with other methods is made whenever possible. The results reveal that nonlinear synthesis, aided by the discussed techniques, provides considerable enhancements compared to linear synthesis.

  11. 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...... 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...

  12. 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

  13. Experimental evaluation of shape memory alloy actuation technique in adaptive antenna design concepts

    Science.gov (United States)

    Kefauver, W. Neill; Carpenter, Bernie F.

    1994-01-01

    Creation of an antenna system that could autonomously adapt contours of reflecting surfaces to compensate for structural loads induced by a variable environment would maximize performance of space-based communication systems. Design of such a system requires the comprehensive development and integration of advanced actuator, sensor, and control technologies. As an initial step in this process, a test has been performed to assess the use of a shape memory alloy as a potential actuation technique. For this test, an existing, offset, cassegrain antenna system was retrofit with a subreflector equipped with shape memory alloy actuators for surface contour control. The impacts that the actuators had on both the subreflector contour and the antenna system patterns were measured. The results of this study indicate the potential for using shape memory alloy actuation techniques to adaptively control antenna performance; both variations in gain and beam steering capabilities were demonstrated. Future development effort is required to evolve this potential into a useful technology for satellite applications.

  14. Determination of the Phase Centers of Millimeter-Wave Horn Antennas Using a Holographic Interference Technique

    Science.gov (United States)

    McAuley, Ian; Murphy, J. Anthony; McCarthy, Darragh; Gradziel, Marcin; Mahon, Ronan; O'Sullivan, Creidhe; Trappe, Neil

    2016-04-01

    In this paper, we discuss how a holographic interference technique can be applied in the experimental determination of the phase centers of non-standard horn antennas in the millimeter-waveband. The phase center is the point inside the horn from which the radiation appears to emanate when viewed from the far-field, and knowing its location is necessary for optimizing coupling efficiencies to quasi-optical systems. For non-standard horn designs, and other feed structures, the phase center may be difficult to reliably predict by simulation, in which case, before committing to antenna manufacture, there is a requirement for it to be determined experimentally. Although the phase center can be recovered by direct phase measurement of the far-field beam pattern, this usually involves expensive instrumentation such as a vector network analyzer for millimeter wave horn antennas. In this paper, we describe one inexpensive alternative, which is based on measuring the interference pattern in intensity between the radiation from the horn of interest and a reference beam derived from the same coherent source in an off-axis holography setup. The accuracy of the approach is improved by comparison with the interference pattern of a well-understood standard horn (such as a corrugated conical horn) in the same experimental setup. We present an example of the technique applied to a profiled smooth-walled horn antenna, which has been especially designed for cosmic microwave background (CMB) polarization experiments.

  15. Muon Diagnostics : A New Technique of Heliosphere Investigations

    NARCIS (Netherlands)

    Petrukhin, A. A.

    2009-01-01

    A new technique of remote monitoring of dynamic processes in the heliosphere (muon diagnostics) has been presented. The approach is based on the analysis of spatial-angular and temporal variations of muon flux detected at the ground level simultaneously from all directions of the upper hemisphere. F

  16. Root Cause Analysis - A Diagnostic Failure Analysis Technique for Managers

    Science.gov (United States)

    1975-03-26

    AA~ TECHNICAL REPORT RF-75-2 yAbom 0 ROOT CAUSE ANALYSIS - A DIAGNOSTIC FAILURE ANALYSIS TECHNIQUE FOR MANAGERS Augustine E. Magistro Nuclear...through 1975. rB Augustine E. Magistro has participated in root cause analysis task tem including team member and Blue Ribbon A panel reviewer, team

  17. Multihop relaying and multiple antenna techniques: performance trade-offs in cellular systems

    OpenAIRE

    Jacobson Kevin; Krzymień Witold

    2011-01-01

    Abstract Two very important and active areas of wireless research are multihop relaying and multiple antenna techniques. Wireless multihop relaying can increase the aggregate network data capacity and improve coverage of cellular systems by reducing path loss, mitigating shadowing, and enabling spatial reuse. In particular, multihop relaying can improve the throughput for mobiles suffering from poor signal to interference and noise ratio at the edge of a cell and reduce cell size to increase ...

  18. 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 ...

  19. Diagnostic Emergency Ultrasound: Assessment Techniques In The Pediatric Patient.

    Science.gov (United States)

    Guttman, Joshua; Nelson, Bret P

    2016-01-01

    Emergency ultrasound is performed at the point of care to answer focused clinical questions in a rapid manner. Over the last 20 years, the use of this technique has grown rapidly, and it has become a core requirement in many emergency medicine residencies and in some pediatric emergency medicine fellowships. The use of emergency ultrasound in the pediatric setting is increasing due to the lack of ionizing radiation with these studies, as compared to computed tomography. Utilizing diagnostic ultrasound in the emergency department can allow clinicians to arrive at a diagnosis at the bedside rather than sending the patient out of the department for another study. This issue focuses on common indications for diagnostic ultrasound, as found in the pediatric literature or extrapolated from adult literature where pediatric evidence is scarce. Limitations, current trends, controversies, and future directions of diagnostic ultrasound in the emergency department are also discussed.

  20. 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.

  1. 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.

  2. CHANNEL ESTIMATION TECHNIQUE IN MULTI-ANTENNA AF RELAY COMMUNICATION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Chen Mingxue; Xu Chengqi

    2011-01-01

    The channel estimation technique is investigated in OFDM communication systems with multi-antenna Amplify-and-Forward (AF) relay.The Space-Time Block Code (STBC) is applied at the transmitter of the relay to obtain diversity gain.According to the transmission characteristics of OFDM symbols on multiple antennas,a pilot-aided Linear Minimum Mean-Square-Error (LMMSE) channel estimation algorithm with low complexity is designed.Simulation results show that,the proposed LMMSE estimator outperforms least-square estimator and approaches the optimal estimator without error in the performance of Symbol Error Ratio (SER) under several modulation modes,and has a good estimation effect in the realistic relay communication scenario.

  3. Application of adaptive antenna techniques to future commercial satellite communications. Executive summary

    Science.gov (United States)

    Ersoy, L.; Lee, E. A.; Matthews, E. W.

    1987-01-01

    The purpose of this contract was to identify the application of adaptive antenna technique in future operational commercial satellite communication systems and to quantify potential benefits. The contract consisted of two major subtasks. Task 1, Assessment of Future Commercial Satellite System Requirements, was generally referred to as the Adaptive section. Task 2 dealt with Pointing Error Compensation Study for a Multiple Scanning/Fixed Spot Beam Reflector Antenna System and was referred to as the reconfigurable system. Each of these tasks was further subdivided into smaller subtasks. It should also be noted that the reconfigurable system is usually defined as an open-loop system while the adaptive system is a closed-loop system. The differences between the open- and closed-loop systems were defined. Both the adaptive and reconfigurable systems were explained and the potential applications of such systems were presented in the context of commercial communication satellite systems.

  4. Unbiased stereologic techniques for practical use in diagnostic histopathology

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt

    1995-01-01

    by introducing quantitative techniques in the histopathologic discipline of malignancy grading. Unbiased stereologic methods, especially based on measurements of nuclear three-dimensional mean size, have during the last decade proved their value in this regard. In this survey, the methods are reviewed regarding...... grading. Surgical pathologists can use a wide range of these techniques in the routine of diagnostic and scientific work. It is not the intention, however, to give an extensive review of the methodology, but two other techniques will be covered: Unbiased estimation of volume of, and total tumor cell...... 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...

  5. Development of Local Oscillator Integrated Antenna Array for Electron Cyclotron Emission Imaging Diagnostics

    Science.gov (United States)

    Kuwahara, Daisuke; Ito, Naoki; Nagayama, Yoshio; Tsuchiya, Hayato; Yoshikawa, Masayuki; Kohagura, Junko; Yoshinaga, Tomokazu; Yamaguchi, Soichiro; Kogi, Yuichiro; Mase, Atsushi

    2016-10-01

    Microwave imaging systems include difficulties in terms of multi-channelization and cost. Our group 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. 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. However, the LIA still has problems, that the instabilities of the sensitivity and poor channel isolation. This paper describes the principle of the LIA, and solutions of above-mentioned problems. This work is performed with the support and under the auspices of the NIFS Collaborative Research Program (NIFS15KOAP029 and NIFS16KUGM115).

  6. 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.

    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...

  7. 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.

  8. VLBI collimation-tower technique for time-delay studies of a large ground-station communications antenna

    Science.gov (United States)

    Otoshi, T. Y.; Young, L. E.; Rusch, W. V. T.

    1985-01-01

    A need for an accurate but inexpensive method for measuring and evaluating time delays of large ground antennas for VLBI applications motivated the development of the collimation tower technique. Supporting analytical work which was performed primarily to verify time delay measurement results obtained for a large antenna when the transmitter was at a collimation distance of 1/25 of the usual far field criterion is discussed. Comparisons of theoretical and experimental results are also given.

  9. 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

    antenna is located behind the blankets and views the plasma through the gap between two blanket modules. The viewing gap has been modified to dimensions 30 × 500 mm2 to optimize the CTS signal. A 1:1 mock-up of the HFS mirror system was built. Measurements of the beam characteristics for millimeter......-waves at 60 GHz used in the mock-up agree well with the modeling....

  10. Multilayer Strip Dipole Antenna Using Stacking Technique and Its Application for Curved Surface

    Directory of Open Access Journals (Sweden)

    Charinsak Saetiaw

    2013-01-01

    Full Text Available This paper presents the design of multilayer strip dipole antenna by stacking a flexible copper-clad laminate utilized for curved surface on the cylindrical objects. The designed antenna will reduce the effects of curving based on relative lengths that are changed in each stacking flexible copper-clad laminate layer. Curving is different from each layer of the antenna, so the resonance frequency that resulted from an extended antenna provides better frequency response stability compared to modern antenna when it is curved or attached to cylindrical objects. The frequency of multilayer antenna is designed at 920 MHz for UHF RFID applications.

  11. Experimental validation of a new bianisotropic parameter retrieval technique using plasmonic metasurfaces made of V-shape antennas

    Science.gov (United States)

    Liu, Jingjing; Shaltout, Amr M.; Ni, Xingjie; Shalaev, Vladimir M.; Kildishev, Alexander V.

    2013-09-01

    We report on a numerical study of a new bianisotropic parameter retrieval technique for both regular and complementary V-shape antenna metasurfaces. Each antenna element with a discrete phase shift is modeled by a homogenous bianisotropic film to represent the optical response. For the complementary design, the retrieval implies a complementary behavior of effective material properties and predicts the analogous functionalities. Further, FDFD solver is developed to integrate the bianisotropic descriptions of each antenna and describes a fully functional metasurface. The computational burden is significantly reduced, because effective material properties replace the detailed meshing of the antennas. Experimentally, large dimension arrays of nano-voids are fabricated using electron beam lithography. It is demonstrated that cross-polarized light is diffracted towards the same direction. Furthermore, the complementary design greatly increases the extinction ratio of functional fields to background fields.

  12. A First/Third-Order Probe Correction Technique for Spherical Near-Field Antenna Measurements Using Three Probe Orientations

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Breinbjerg, Olav

    2008-01-01

    A probe correction technique is described for spherical near-field antenna measurements based on sampling the near field for three probe orientations in each measurement direction. The technique applies to odd-order probes whose radiated field contains (significant) power only in the first (µ=±1)...

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

    NARCIS (Netherlands)

    Molenaar, P.A.; Straten, P. van der; 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

  14. 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

  15. A New Technique for Vernier Pointing of a Beam-Waveguide Antenna

    Science.gov (United States)

    Veruttipong, Watt; Bathker, Dan A.

    1994-01-01

    This paper presents a new and simple approach for the Ka-band vernier pointing of a 34m beam-waveguide (BWG) antenna (also applicable to a 70m antenna. In this study, rotation of a BWG flat mirror, located at the elevation axis, is used to scan the beam instead of using the very large tipping structure of the antenna.

  16. Diagnostic techniques for measuring suprathermal electron dynamics in plasmas (invited).

    Science.gov (United States)

    Coda, S

    2008-10-01

    Plasmas, both in the laboratory and in space, are often not in thermodynamic equilibrium, and the plasma electron distribution function is accordingly non-Maxwellian. Suprathermal electron tails can be generated by external drives, such as rf waves and electric fields, or internal ones, such as instabilities and magnetic reconnection. The variety and importance of the phenomena in which suprathermal electrons play a significant role explains an enduring interest in diagnostic techniques to investigate their properties and dynamics. X-ray bremsstrahlung emission has been studied in hot magnetized plasmas for well over two decades, flanked progressively by electron-cyclotron emission in geometries favoring the high-energy end of the distribution function (high-field-side, vertical, oblique emission), by electron-cyclotron absorption, by spectroscopic techniques, and at lower temperatures, by Langmuir probes and electrostatic analyzers. Continuous progress in detector technology and in measurement and analysis techniques, increasingly sophisticated layouts (multichannel and tomographic systems, imaging geometries), and highly controlled suprathermal generation methods (e.g., perturbative rf modulation) have all been brought to bear in recent years on an increasingly detailed, although far from complete, understanding of suprathermal electron dynamics.

  17. 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

  18. Antenna diagnostics for power flow in extreme near-field of a standard gain horn

    DEFF Research Database (Denmark)

    Popa, Paula Irina; Breinbjerg, Olav

    2016-01-01

    wave spectrum actually allows for determination of both magnitude and phase of all three components of the electric as well as the magnetic field - and thus also the Poynting vector. In this work we focus on the Poynting vector and thus the power flow in the extreme near-field; as an example we employ...... a 60 GHz standard gain horn. Measurements obtained with a planar near-field antenna measurement set-up reveal that the power flow has not only a normal component - but also tangential components - in the aperture and, furthermore, that these components possess oscillations along the E-plane. We show......-diffracted fields in the horn aperture. An analytical model based on the Geometrical Theory of Diffraction is established, and it is demonstrated that this model qualitatively as well as quantitatively predicts the measurement results for the power flow. A full-wave analysis is carried out and the simulation...

  19. 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...

  20. 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.

  1. 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.

  2. The reliability of specific sacro-occipital technique diagnostic tests.

    Science.gov (United States)

    Leboeuf, C

    1991-01-01

    Four interexaminer and one intraexaminer agreement studies were performed on specific diagnostic tests commonly employed within sacro-occipital technique (SOT). Ten of the tests were evaluated in more than one interexaminer study. Of these, only one test (bilateral supine leg raise with cervical compaction) had at least fair reliability more than once. Six of these 10 tests obtained poor agreement in more than one study. One examiner out of two had a number of excellent and fair intraexaminer values, whereas the other examiner generally had poor results. There may have been some treatment effect as a comparison of the combined intraexaminer diagnosis for two observers after no treatment and after treatment showed that the repeatability diminished from Kappa of 0.36 in untreated cases (which were expected to have high agreement of before and after treatment findings) to a Kappa of 0.27 for those subjects having received treatment (which were expected to have low agreement of before and after treatment findings). It appears unlikely that SOT tests can be reproduced to a sufficiently high degree to constitute useful clinical procedures.

  3. 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.

  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...

  5. 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

  6. Data multiplexing with a single antenna structure and front-end: antenna-coding techniques and design examples

    DEFF Research Database (Denmark)

    Perruisseau-Carrier, Julien; Yousefbeiki, Mohsen; Alrabadi, Osama;

    2012-01-01

    In this paper, we present an investigation on the impact of spatial smoothing and forward-backward averaging techniques for subspace-based channel estimation. The spatial smoothing technique requires the selection of a window size, which, if not chosen properly, leads to dramatic performance...... breakdown of subspace-based methods. We provide an explanation of the performance drop for certain window sizes and subsequently an understanding of a proper window size selection. In particular, we describe the behavior of the magnitude of the least signal eigenvalue as a function of the used window size...

  7. Developpement de techniques de diagnostic non intrusif par tomographie optique

    Science.gov (United States)

    Dubot, Fabien

    Que ce soit dans les domaines des procedes industriels ou de l'imagerie medicale, on a assiste ces deux dernieres decennies a un developpement croissant des techniques optiques de diagnostic. L'engouement pour ces methodes repose principalement sur le fait qu'elles sont totalement non invasives, qu'elle utilisent des sources de rayonnement non nocives pour l'homme et l'environnement et qu'elles sont relativement peu couteuses et faciles a mettre en oeuvre comparees aux autres techniques d'imagerie. Une de ces techniques est la Tomographie Optique Diffuse (TOD). Cette methode d'imagerie tridimensionnelle consiste a caracteriser les proprietes radiatives d'un Milieu Semi-Transparent (MST) a partir de mesures optiques dans le proche infrarouge obtenues a l'aide d'un ensemble de sources et detecteurs situes sur la frontiere du domaine sonde. Elle repose notamment sur un modele direct de propagation de la lumiere dans le MST, fournissant les predictions, et un algorithme de minimisation d'une fonction de cout integrant les predictions et les mesures, permettant la reconstruction des parametres d'interet. Dans ce travail, le modele direct est l'approximation diffuse de l'equation de transfert radiatif dans le regime frequentiel tandis que les parametres d'interet sont les distributions spatiales des coefficients d'absorption et de diffusion reduit. Cette these est consacree au developpement d'une methode inverse robuste pour la resolution du probleme de TOD dans le domaine frequentiel. Pour repondre a cet objectif, ce travail est structure en trois parties qui constituent les principaux axes de la these. Premierement, une comparaison des algorithmes de Gauss-Newton amorti et de Broyden- Fletcher-Goldfarb-Shanno (BFGS) est proposee dans le cas bidimensionnel. Deux methodes de regularisation sont combinees pour chacun des deux algorithmes, a savoir la reduction de la dimension de l'espace de controle basee sur le maillage et la regularisation par penalisation de Tikhonov

  8. 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.

  9. 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.

  10. Endoscopy as a diagnostic and therapeutic alternative technique of taeniasis

    Directory of Open Access Journals (Sweden)

    Héctor Julian Canaval-Zuleta

    Full Text Available Despite a low incidence in developed countries, gastrointestinal taeniasis should be suspected in patients with abdominal pain, diarrhea, anemia, and/or malabsorption of unknown origin, even more so if they come from endemic regions or areas with poor hygienic and alimentary habits. Diagnosis is traditionally reached by identifying the parasite in stools, but more recently both serological and immunological approaches are also available. Based on a patient diagnosed by gastroscopy, a literature review was undertaken of patients diagnosed by endoscopy. We discuss endoscopy as diagnostic modality, and the effectiveness and safety that endoscopic treatment may provide in view of the potential risk for neurocysticercosis.

  11. Endoscopy as a diagnostic and therapeutic alternative technique of taeniasis.

    Science.gov (United States)

    Canaval Zuleta, Héctor Julián; Company Campins, María M; Dolz Abadía, Carlos

    2016-06-01

    Despite a low incidence in developed countries, gastrointestinal taeniasis should be suspected in patients with abdominal pain, diarrhea, anemia, and/or malabsorption of unknown origin, even more so if they come from endemic regions or areas with poor hygienic and alimentary habits. Diagnosis is traditionally reached by identifying the parasite in stools, but more recently both serological and immunological approaches are also available. Based on a patient diagnosed by gastroscopy, a literature review was undertaken of patients diagnosed by endoscopy. We discuss endoscopy as diagnostic modality, and the effectiveness and safety that endoscopic treatment may provide in view of the potential risk for neurocysticercosis.

  12. Comparison of the FFT/matrix inversion and system matrix techniques for higher-order probe correction in spherical near-field antenna measurements

    DEFF Research Database (Denmark)

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

    2011-01-01

    Two higher-order probe-correction techniques for spherical near-field antenna measurements are compared in details for the accuracy they provide and their computational cost. The investigated techniques are the FFT/matrix inversion and the system matrix inversion. Each of these techniques allows...

  13. Laboratory diagnosis of Toxoplasma gondii infection with direct and indirect diagnostic techniques

    Directory of Open Access Journals (Sweden)

    Salvatore Pignanelli

    2011-01-01

    Full Text Available Background: Toxoplasma gondii infection, common parasitic zoonoses, is an important cause of spontaneous abortion, mental retardation, encephalitis, ocular disease and death worldwide. Today the major diagnostic techniques for the toxoplasmosis are serological assays, but its have many limitations. Aim : The goal in this study is to improve the diagnostic accuracy of T. gondii infection, using direct (Real Time PCR and indirect (IgM, IgA, IgG and IgG avidity diagnostic techniques. Materials and Methods: In the period between 2007 and 2008, 96 non consecutive different clinical samples (38 blood, 40 amniotic fluids, 8 cerebrospinal fluids, 10 vitreous humors and 96 sera have been studied simultaneously through molecular biology and serological techniques. Results: Direct and indirect diagnostic techniques used in this study for laboratory diagnosis of T. gondii infection were always concordant. Conclusions : The high correlation between direct and indirect diagnostic techniques exhibit that serologic techniques are accurate diagnostic assays as screening test in laboratory diagnosis of toxoplasmosis.

  14. Mid-infrared diagnostics of starburst galaxies: clumpy, dense structures in star-forming regions in the Antennae (NGC 4038/4039)

    CERN Document Server

    Snijders, Leonie; van der Werf, Paul P

    2007-01-01

    Recently, mid-infrared instruments have become available on several large ground-based telescopes, resulting in data sets with unprecedented spatial resolution at these long wavelengths. In this paper we examine 'ground-based-only' diagnostics, which can be used in the study of star-forming regions in starburst galaxies. By combining output from the stellar population synthesis code Starburst 99 with the photoionization code Mappings, we model stellar clusters and their surrounding interstellar medium, focusing on the evolution of emission lines in the N- and Q-band atmospheric windows (8-13 and 16.5-24.5 micron respectively) and those in the near-infrared. We address the detailed sensitivity of various emission line diagnostics to stellar population age, metallicity, nebular density, and ionization parameter. Using our model results, we analyze observations of two stellar clusters in the overlap region of the Antennae galaxies obtained with VLT Imager and Spectrometer for mid Infrared (VISIR). We find eviden...

  15. An Iterative Technique for the Synthesis of Active Antenna Oscillator Arrays

    Directory of Open Access Journals (Sweden)

    Theodoros N. Kaifas

    2009-01-01

    Full Text Available A design procedure for the synthesis of a coupled active antenna oscillator array is presented. Such an array is synthesized by deriving two sets of parameters: the radiators' positions and the oscillators' outputs. The outputs are used to excite the radiators. Minimization of the mean square error between the desired pattern and the resulting one is made. Synthesis starts from an initial array, which is perturbed iteratively by varying simultaneously the element excitations and positions. In the iteration, the first variation of the cost function is set equal to zero. The final array results from the last iteration, where the stopping criteria are met. The procedure designs simultaneously both the antenna and the attached coupled oscillator array providing viable solutions. The second by properly configuring the tuning parameters through the use of closed-form formulas. The resulting arrays are shown to comply with the desired pattern and the nonlinear dynamics thus proving the validity of our method.

  16. 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

  17. An Iterative Technique for the Synthesis of Active Antenna Oscillator Arrays

    OpenAIRE

    Kaifas, Theodoros N.; Sahalos, John N.

    2009-01-01

    A design procedure for the synthesis of a coupled active antenna oscillator array is presented. Such an array is synthesized by deriving two sets of parameters: the radiators' positions and the oscillators' outputs. The outputs are used to excite the radiators. Minimization of the mean square error between the desired pattern and the resulting one is made. Synthesis starts from an initial array, which is perturbed iteratively by varying simultaneously the element excitations and positions. In...

  18. 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 ...

  19. 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.

  20. 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.

  1. Measurement Techniques for Electrothermal-Chemical Gun Diagnostics

    Science.gov (United States)

    1993-12-01

    conductors of a circuit ( Askeland 1985). This technique has been successfully applied to other experimental work including the pressure measurements made in...Fe2O4 ( Askeland 1985). Ferrites are implemented by wrapping the power cords and coaxial data lines of all electronics equipment tightly for several... Askeland , D. R. The Sciece and Engineering of Materials. Prindle, Weber, and Schmidt, 1985. Burden. H. S., and D. D. Shear. "Transient Noise in Electronic

  2. [THE CYTOMETRIC TECHNIQUE OF BINDING OF EOSIN-5-MALEIMIDE IN DIAGNOSTIC OF INHERENT SPHEROCYTOSIS].

    Science.gov (United States)

    Kuzminova, J A; Plyasunova, S A; Jogov, V V; Smetanina, N S

    2016-03-01

    The laboratory diagnostic of inherent spherocytosis is based on detection of spherocytes in peripheral blood, decreasing of index of sphericity, decreasing of osmotic resistance of erythrocytes. The new test of diagnostic of hereditary spherocytosis build on molecular defect was developed on the basis of binding extracellular fragments of protein of band 3 with eosin-5-maleimide (EMA-test). The study was carried out to implement comparative analysis of sensitivity and specificity of techniques applied to diagnose inherent spherocytosis. The sampling of 94 patients with various forms of anemias was analyzed All patients were applied complex clinical laboratory examination including analysis of osmotic resistance of erythrocytes, erythrocytometry and EMA-test as specific techniques of diagnostic of inherent spherocytosis. In 51 out of 94 patients (54%) decreasing of values of EMA-test was detected and in 47 patients diagnosis of inherent spherocytosis was confirmed. The standard values of EMA-test were established in 43 patients (46%) and 12 patients out of them with established diagnosis of inherent spherocytosis. Therefore, sensitivity of EMA-test made up to 79% and specificity - 80%. The most sensitive techniques of diagnostic remain osmotic resistance of erythrocytes (91%) and index of sphericity (up to 96%). But the highest specificity in this respect has EMA-test (80%). Nowadays, none of implemented techniques of diagnostic of inherent spherocytosis can be applied as a universal one. The implementation of complex examination is needed for proper diagnostic of disease.

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

    Science.gov (United States)

    Delogu, R. S.; Poggi, C.; Pimazzoni, A.; Rossi, G.; Serianni, G.

    2016-02-01

    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.

  4. 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.

  5. Biological Inspired Stochastic Optimization Technique (PSO for DOA and Amplitude Estimation of Antenna Arrays Signal Processing in RADAR Communication System

    Directory of Open Access Journals (Sweden)

    Khurram Hammed

    2016-01-01

    Full Text Available This paper presents a stochastic global optimization technique known as Particle Swarm Optimization (PSO for joint estimation of amplitude and direction of arrival of the targets in RADAR communication system. The proposed scheme is an excellent optimization methodology and a promising approach for solving the DOA problems in communication systems. Moreover, PSO is quite suitable for real time scenario and easy to implement in hardware. In this study, uniform linear array is used and targets are supposed to be in far field of the arrays. Formulation of the fitness function is based on mean square error and this function requires a single snapshot to obtain the best possible solution. To check the accuracy of the algorithm, all of the results are taken by varying the number of antenna elements and targets. Finally, these results are compared with existing heuristic techniques to show the accuracy of PSO.

  6. 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.

  7. Review of Physicochemical-Based Diagnostic Techniques for Assessing Insulation Condition in Aged Transformers

    Directory of Open Access Journals (Sweden)

    Janvier Sylvestre N’cho

    2016-05-01

    Full Text Available A power transformer outage has a dramatic financial consequence not only for electric power systems utilities but also for interconnected customers. The service reliability of this important asset largely depends upon the condition of the oil-paper insulation. Therefore, by keeping the qualities of oil-paper insulation system in pristine condition, the maintenance planners can reduce the decline rate of internal faults. Accurate diagnostic methods for analyzing the condition of transformers are therefore essential. Currently, there are various electrical and physicochemical diagnostic techniques available for insulation condition monitoring of power transformers. This paper is aimed at the description, analysis and interpretation of modern physicochemical diagnostics techniques for assessing insulation condition in aged transformers. Since fields and laboratory experiences have shown that transformer oil contains about 70% of diagnostic information, the physicochemical analyses of oil samples can therefore be extremely useful in monitoring the condition of power transformers.

  8. 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.

  9. Comparison of Real-Time Kinematic GNSS Positioning Techniques Using Moving and Stationary Antennas

    Science.gov (United States)

    Berglund, H. T.; Blume, F.; Mencin, D.; Estey, L. H.

    2013-12-01

    The use of high-rate and real-time GNSS measurements for hazards monitoring and scientific applications is still in its infancy and there is great potential for its integration with strain, gravity and seismic measurements. Many commercial vendors and public agencies now offer real-time positioning services that provide sub-decimeter accuracy, with some approaching the sub-centimeter level. As GNSS network operators begin transitioning into offering real-time products, they will need to consider a number of factors including but not limited to: cost, position accuracy, solution latency, network topology and bandwidth. Periodic evaluation of real-time positioning systems will need to be conducted in order to optimize their integration into hazard-monitoring and multi-disciplinary networks. Controlled outdoor kinematic and static experiments provide a useful method for evaluating real-time systems, helping to identify system limitations, and characterize performance and reliability. Preliminary findings from tests using a static antenna and a comparison of real-time kinematic positioning methods will be highlighted. For the purpose of characterizing the performance of real-time kinematic software, UNAVCO has begun development of a low-cost portable kinematic antenna test system. Comparisons of real-time GNSS positioning algorithms can now be made at our facility and at remote locations. Coordinated multi-site simulation of antenna displacements over a regional sized network could provide a useful test for real-time GNSS earthquake source determination algorithms. Various GNSS site geometries could be investigated to determine adequate configurations for capturing the ground displacement information needed to resolve earthquake source models. Preliminary designs will be discussed. Trimble's recently released real-time positioning service, RTX, promises ~4 cm accuracy with 95% confidence using a global Precise Point Positioning algorithm. RTX can be run on individual

  10. 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

  11. 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.

  12. Anesthesia Technique In A Patient With Langerhans Cell Histiocytosis For Diagnostic Biopsy

    Directory of Open Access Journals (Sweden)

    Abdi S

    2005-07-01

    Full Text Available Histiocytosis under general anesthesia. In these patients, depend on organs involvement and dysfunction, anesthesia technique and specific drugs should be selected.of langerhans cells consist of a range of clinical manifestations, including bone eosimophilic granuloma, Hand-Schuller-Chiristian syndrome and Letterer-Siwe disease. Definitive diagnosis is based on biopsy of involved tissues. This report describes anesthesia technique in a 2 years old girl for diagnostic biopsy

  13. The Sandtray Technique for Swedish Children 1945-1960: Diagnostics, Psychotherapy and Processes of Individualisation

    Science.gov (United States)

    Nelson, Karin Zetterqvist

    2011-01-01

    The present article examines the development of a diagnostic and therapeutic technique named The Sandtray at the Erica Foundation, a privately-run child counselling service in Stockholm. Originally it was called The World, developed by the British paediatrician and child psychiatrist Margaret Lowenfeld. In the 1930s it was imported to Sweden,…

  14. A novel technique for detecting antibiotic-resistant typhoid from rapid diagnostic tests.

    OpenAIRE

    2015-01-01

    Fluoroquinolone-resistant typhoid is increasing. An antigen-detecting rapid diagnostic test (RDT) can rapidly diagnose typhoid from blood cultures. A simple, inexpensive molecular technique performed with DNA from positive RDTs accurately identified gyrA mutations consistent with phenotypic susceptibility testing results. Field diagnosis combined with centralized molecular resistance testing could improve typhoid management and surveillance in low-resource settings.

  15. System Structure and Key Techniques of Smart Skin Antennas%智能蒙皮天线的体系构架与关键技术

    Institute of Scientific and Technical Information of China (English)

    何庆强; 王秉中; 何海丹

    2014-01-01

    Different from traditional antenna design methods, the new system structure of smart skin anten-nas is proposed, and the key technique realizations of smart skin antennas are discussed. The beam self-adapting of smart skin antennas is realized based on the reconfiguration technique in RF-layer and signal processing method in back-end, and the limit of traditional antenna by using only signal processing method is overcome. And then, the realizing methods of packaging layer, RF-layer, and controlling and signal processing layer are analyzed in detail. Finally, according to the application requirements for future aero-craft, the key techniques and design methods of smart skin antennas are presented.%区别于传统天线设计方法,提出了一种新的智能蒙皮天线设计架构,探讨了实现智能蒙皮天线的关键技术。通过在射频功能层采用可重构技术和在后端采用信号处理的方法,实现了智能蒙皮天线的波束自适应,解决了传统天线仅仅依靠信号处理方式来实现天线波束自适应的局限。分析了智能蒙皮天线的封装功能层、射频功能层以及控制与信号处理功能层的实现措施。最后针对新一代航空平台的应用需求,进一步探讨了智能蒙皮天线的关键技术和实现方法。

  16. Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering.

    Science.gov (United States)

    Ehn, Andreas; Zhu, Jiajian; Li, Xuesong; Kiefer, Johannes

    2017-03-01

    Gaining information of species, temperature, and velocity distributions in turbulent combustion and high-speed reactive flows is challenging, particularly for conducting measurements without influencing the experimental object itself. The use of optical and spectroscopic techniques, and in particular laser-based diagnostics, has shown outstanding abilities for performing non-intrusive in situ diagnostics. The development of instrumentation, such as robust lasers with high pulse energy, ultra-short pulse duration, and high repetition rate along with digitized cameras exhibiting high sensitivity, large dynamic range, and frame rates on the order of MHz, has opened up for temporally and spatially resolved volumetric measurements of extreme dynamics and complexities. The aim of this article is to present selected important laser-based techniques for gas-phase diagnostics focusing on their applications in combustion and aerospace engineering. Applicable laser-based techniques for investigations of turbulent flows and combustion such as planar laser-induced fluorescence, Raman and Rayleigh scattering, coherent anti-Stokes Raman scattering, laser-induced grating scattering, particle image velocimetry, laser Doppler anemometry, and tomographic imaging are reviewed and described with some background physics. In addition, demands on instrumentation are further discussed to give insight in the possibilities that are offered by laser flow diagnostics.

  17. 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

  18. Calibration techniques for fast-ion D{sub {alpha}} diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Heidbrink, W. W.; Bortolon, A.; Muscatello, C. M.; Ruskov, E. [University of California, Irvine, California 92697 (United States); Grierson, B. A.; Podesta, M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2012-10-15

    Fast-ion D{sub {alpha}} measurements are an application of visible charge-exchange recombination (CER) spectroscopy that provide information about the energetic ion population. Like other CER diagnostics, the standard intensity calibration is obtained with an integrating sphere during a vacuum vessel opening. An alternative approach is to create plasmas where the fast-ion population is known, then calculate the expected signals with a synthetic diagnostic code. The two methods sometimes agree well but are discrepant in other cases. Different background subtraction techniques and simultaneous measurements of visible bremsstrahlung and of beam emission provide useful checks on the calibrations and calculations.

  19. 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

  20. Principle for the Realization of Dual-Orthogonal Linearly Polarized Antennas for UWB Technique

    Directory of Open Access Journals (Sweden)

    Grzegorz Adamiuk

    2011-01-01

    The presented method introduces a superior possibility of an extension of typical UWB technique to fully polarized systems, which improves significantly performance in, for example, UWB-MIMO or UWB-Radar.

  1. In-vitro and in-vivo diagnostic techniques for prostate cancer: a review.

    Science.gov (United States)

    McClure, Patrick; Elnakib, Ahmed; Abou El-Ghar, Mohamed; Khalifa, Fahmi; Soliman, Ahmed; El-Diasty, Tarek; Suri, Jasjit S; Elmaghraby, Adel; El-Baz, Ayman

    2014-10-01

    This paper overviews one of the most important, interesting, and challenging problems in oncology, early diagnosis of prostate cancer. Developing effective diagnostic techniques for prostate cancer is of great clinical importance and can improve the effectiveness of treatment and increase the patient's chance of survival. The main focus of this study is to overview the different in-vitro and in-vivo technologies for diagnosing prostate cancer. This review discusses the current clinically used in-vitro cancer diagnostic tools, such as biomarker tests and needle biopsies and including their applications, advantages, and limitations. Moreover, the current in-vitro research tools that focus on the role of nanotechnology in prostate cancer diagnosis have been detailed. In addition to the in-vitro techniques, the current study discusses in detail developed in-vivo non-invasive state-of-the-art Computer-Aided Diagnosis (CAD) systems for prostate cancer based on analyzing Transrectal Ultrasound (TRUS) and different types of magnetic resonance imaging (MRI), e.g., T2-MRI, Diffusion Weighted Imaging (DWI), Dynamic Contrast Enhanced (DCE)-MRI, and multi-parametric MRI, focusing on their implementation, experimental procedures, and reported outcomes. Furthermore, the paper addresses the limitations of the current prostate cancer diagnostic techniques, outlines the challenges that these techniques face, and introduces the recent trends to solve these challenges, which include biomarkers used in in-vitro lab-on-a-chip nanotechnology-based methods.

  2. Measurements of diversity gain and radiation efficiency of the eleven antenna by using different measurement techniques

    DEFF Research Database (Denmark)

    Yang, Jian; Pivnenko, Sergey; Laitinen, Tommi

    2010-01-01

    This paper presents measurement results of diversity gain and radiation efficiency by using three different measurement techniques: reverberation chamber, spherical near-field anechoic chamber, and multi-probe anechoic chamber. The results are measured over a large 2–8 GHz bandwidth which...

  3. 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

    2015-12-16

    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.

  4. 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.

  5. Electrical-Based Diagnostic Techniques for Assessing Insulation Condition in Aged Transformers

    Directory of Open Access Journals (Sweden)

    Issouf Fofana

    2016-08-01

    Full Text Available The condition of the internal cellulosic paper and oil insulation are of concern for the performance of power transformers. Over the years, a number of methods have been developed to diagnose and monitor the degradation/aging of the transformer internal insulation system. Some of this degradation/aging can be assessed from electrical responses. Currently there are a variety of electrical-based diagnostic techniques available for insulation condition monitoring of power transformers. In most cases, the electrical signals being monitored are due to mechanical or electric changes caused by physical changes in resistivity, inductance or capacitance, moisture, contamination or aging by-products in the insulation. This paper presents a description of commonly used and modern electrical-based diagnostic techniques along with their interpretation schemes.

  6. Molecular isothermal techniques for combating infectious diseases: towards low-cost point-of-care diagnostics.

    Science.gov (United States)

    de Paz, Hector David; Brotons, Pedro; Muñoz-Almagro, Carmen

    2014-09-01

    Nucleic acid amplification techniques such as PCR have facilitated rapid and accurate diagnosis in central laboratories over the past years. PCR-based amplifications require high-precision instruments to perform thermal cycling reactions. Such equipment is bulky, expensive and complex to operate. Progressive advances in isothermal amplification chemistries, microfluidics and detectors miniaturisation are paving the way for the introduction and use of compact 'sample in-results out' diagnostic devices. However, this paradigm shift towards decentralised testing poses diverse technological, economic and organizational challenges both in industrialized and developing countries. This review describes the landscape of molecular isothermal diagnostic techniques for infectious diseases, their characteristics, current state of development, and available products, with a focus on new directions towards point-of-care applications.

  7. 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.

  8. BRIEF REVIEW ON DIAGNOSTIC TECHNIQUE AND NOVEL MOLECULES IN CLINICAL TRIALS FOR TREATMENT OF BREAST CANCER

    Directory of Open Access Journals (Sweden)

    VISHAL KUMAR S. MODI

    2015-01-01

    Full Text Available Breast cancer is the most common cancer in women in both developed and undeveloped countries, and the second most frequent cause of cancer deaths after lung cancer. Although there have been many chemotherapeutic agents like 5-fluorouracil, taxol, tamoxifen, doxorubicin, cisplatin, and camptothecin and hormones are used to treat breast cancer. This review focuses on the causes of breast cancer, latest diagnostic techniques and various molecules under clinical trials for the treatment of breast cancer.

  9. 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.

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

    Science.gov (United States)

    Kuznetsov, Yu L.; Kalchenko, V. V.; Astaf'eva, N. G.; Meglinski, I. V.

    2014-08-01

    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.

  12. A study of three techniques used in the diffraction analysis of shaped dual-reflector antennas

    Science.gov (United States)

    Cwik, Tom A.; Kildal, Per-Simon

    1989-01-01

    An examination is presented of three techniques used for the efficient computation of fields diffracted by a subreflector that has been shaped by geometrical optics synthesis. It is found that these techniques, which are based on the geometrical theory of diffraction (GTD), produce errors in the computed fields that are specific to shaped reflectors. These errors are examined for a reflector system shaped to produce maximum gain from a tapered feed illumination. The discrepancies are directly related to the caustic being located near an observation point of the GTD calculations. The errors found are localized, and they increase in magnitude as the caustic approaches the main reflector. In a general offset geometry, the location of the caustic may be located arbitrarily close to the main reflector given a prescribed output aperture distribution. For the specific case considered here-the common situation of shaping to produce maximum gain-the caustic is located near the edge of the main reflector and on the reflection shadow boundary. A local correction is derived which creates a uniform solution through the caustic and across the reflection shadow boundary. Away from this point the calculation receeds to the standard GTD solution.

  13. Advanced Techniques and Antenna Design for Pulse Shaping in UWB Cognitive Radio

    Directory of Open Access Journals (Sweden)

    Lise Safatly

    2012-01-01

    Full Text Available Spectrum scarcity has emerged as a primary problem in the communications technology. The combination of cognitive radio (CR and ultra-wideband impulse radio (UWB-IR has been proposed to solve the shortage problem by allowing smart and adaptive spectrum management, leading to UWB-CR. In a UWB-CR scheme, secondary users are supposed to ensure interference avoidance by adaptively selecting the portions of the spectrum not being used by primary users. In this paper, three different techniques for the generation of adaptive UWB pulses are studied. The Parks-McClellan algorithm is employed, a neural network is trained, and a reconfigurable band stop filter is designed to generate an adaptive waveform with nulls at specific frequencies. Simulations, measurements, and analysis show that each generated UWB pulse has remarkable advantages in the frequency utilization, spectrum avoidance, and hardware implementation.

  14. 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

  15. 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

  16. 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

  17. Evaluation of ovine abortion associated with Toxoplasma gondii in Spain by different diagnostic techniques.

    Science.gov (United States)

    Pereira-Bueno, J; Quintanilla-Gozalo, A; Pérez-Pérez, V; Alvarez-García, G; Collantes-Fernández, E; Ortega-Mora, L M

    2004-05-07

    A total of 173 aborted ovine foetuses and seven aborted caprine foetuses, submitted from different points of north and central Spain, were analysed to determine the role of T. gondii in abortion and to compare the utility of the most widely used techniques in diagnosis of the congenital infection (histopathology, serology--IFAT and ELISA--and a nested-PCR). Parasite infection was diagnosed in 40 (23.1%; n = 173) ovine foetuses by at least one of the diagnostic techniques used. A higher percentage of foetuses were diagnosed using serological techniques (IFAT and ELISA) (28.3%; n = 106) than by histologic examination (8.7%; n = 173) or PCR (6.9%; n = 173). No significant association between infection and the foetal age categories was found (P > 0.05). In this study, 106 aborted foetuses were analysed by all of the three diagnostic techniques. When we compared serological results, perfect agreement between ELISA and IFAT was obtained. On the contrary, slight to fair agreements were observed when histology results were compared with those obtained by serology and PCR techniques. All the positive foetuses were aborted in the mid (60%) or last (40%) term of pregnancy, but no significant differences were found between ages of the infected and non-infected foetuses (P > 0.05). This report indicates that toxoplasmosis may be a common cause of small ruminant abortion and neonatal death in Spain and points out the necessity of using different and complementary techniques to increase the probability of detecting Toxoplasma infection in an aborted foetus.

  18. 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.)

  19. 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)

  20. Mycoplasma pneumoniae: Current knowledge on nucleic acid amplification techniques and serological diagnostics

    Directory of Open Access Journals (Sweden)

    Katherine eLoens

    2016-03-01

    Full Text Available Mycoplasma pneumoniae (M. pneumoniae belongs to the class Mollicutes and has been recognized as a common cause of respiratory tract infections (RTIs, including community-acquired pneumonia (CAP, that occur worldwide and in all age groups. In addition, M. pneumoniae can simultaneously or sequentially lead to damage in the nervous system and has been associated with a wide variety of other acute and chronic diseases. During the past 10 years, the proportion of LRTI in children and adults, associated with M. pneumoniae infection has ranged from 0% to more than 50%. This variation is due to the age and the geographic location of the population examined but also due to the diagnostic methods used. The true role of M. pneumoniae in RTIs remains a challenge given the many limitations and lack of standardization of the applied diagnostic tool in most cases, with resultant wide variations in data from different studies.Correct and rapid diagnosis and/or management of M. pneumoniae infections is, however, critical to initiate appropriate antibiotic treatment and is nowadays usually done by PCR and/or serology. Several recent reviews have summarized current methods for the detection and identification of M. pneumoniae. This review will therefore provide a look at the general principles, advantages, diagnostic value, and limitations of the most currently used detection techniques for the etiological diagnosis of a M. pneumoniae infection as they evolve from research to daily practice.

  1. 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.

  2. Application of RNB for high sensitive wear diagnostics in medicine technique and industry

    Energy Technology Data Exchange (ETDEWEB)

    Fehsenfeld, P. E-mail: Peter.Fehsenfeld@hzy.fzk.de; Eifrig, C.; Kubat, R

    2002-04-22

    The RTM--Radionuclide Technique in Mechanical engineering--is now extended to the solution of world wide problems in medicine technique (prosthetics), and in development of modern materials (synthetic materials, ceramics, hard coatings, etc.) and their industrial application. RNB--Radioactive Nuclear Beams of {sup 7}Be or {sup 22}Na--may enable the required extreme thin radioactive surface labeling (several micrometers) of synthetic materials for wear measurements without producing radiation damages of influence to the wear properties of the material. The function principle and special properties of the RTM on-line wear diagnostics and its components, the measurement methods, the radioactive surface labeling, and the measurement instruments are explained. The quality features of a {sup 7}Be and {sup 22}Na-beam for RTM application are specified.

  3. Antenna gain measurements in the intermediate-field zone

    Science.gov (United States)

    Anchidin, Liliana; Bari, Farida; Dumitrascu, Ana; Paun, Mirel; Deacu, Daniela; Tasu, Sorin; Danisor, Alin; Tamas, Razvan D.

    2016-12-01

    Antenna gain is usually evaluated under far-field conditions. Furthermore, Friis transmission formula can solely be applied when antenna size can be neglected with respect to the distance between the measuring antenna and the antenna under test. In this paper, we show that by applying the distance averaging technique the far-field and antenna size constraints can be overcome. Our method was validated by measuring a monopole antenna and a Vivaldi antenna in an open area test site (OATS).

  4. Diagnostic procedures in tularaemia with special focus on molecular and immunological techniques.

    Science.gov (United States)

    Splettstoesser, W D; Tomaso, H; Al Dahouk, S; Neubauer, H; Schuff-Werner, P

    2005-08-01

    Tularaemia is a severe bacterial zoonosis caused by the highly infectious agent Francisella tularensis. It is endemic in countries of the northern hemisphere ranging from North America to Europe, Asia and Japan. Very recently, Francisella-like strains causing disease in humans were described from tropical northern Australia. In the last decade, efforts have been made to develop sensitive and specific immunological and molecular techniques for the laboratory diagnosis of tularaemia and also for the definite identification of members of the species F. tularensis and its four subspecies. Screening for the keyword 'Francisella' a Medline search over the last decade was performed and articles describing diagnostic methods for tularaemia and its causative agent were selected. Besides classical microbiological techniques (cultivation, biochemical profiling, susceptibility testing) several new immunological and molecular approaches to identify F. tularensis have been introduced employing highly specific antibodies and various polymerase chain reaction (PCR)-based methods. Whereas direct antigen detection by enzyme-linked immunosorbent assay (ELISA) or immunofluorescence might allow early presumptive diagnosis of tularaemia, these methods--like all PCR techniques--still await further evaluation. Therefore, diagnosis of tularaemia still relies mainly on the demonstration of specific antibodies in the host. ELISA and immunoblot methods started to replace the standard tube or micro-agglutination assays. However, the diagnostic value of antibody detection in the very early clinical phase of tularaemia is limited. Francisella tularensis is regarded as a 'highest priority' biological agent (category 'A' according to the CDC, Atlanta, GA, USA), thus rapid and reliable diagnosis of tularaemia is required not only for a timely onset of therapy, the handling of outbreak investigations but also for the surveillance of endemic foci. Only very recently, evaluated test kits for

  5. A study on the fault diagnostic techniques for reactor internal structures using neutron noise analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Ryong; Jeong, Seong Ho; Park, Jin Ho; Park, Jin Suk [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-08-01

    The unfavorable phenomena, such as flow induced vibration and aging process in reactor internals, cause degradation of structural integrity and may result in loosing some mechanical binding components which might impact other equipments and components or cause flow blockage. Since these malfunctions and potential failures change reactor noise signal, it is necessary to analyze reactor noise signal for early fault diagnosis in the point of few of safety and plant economics. The objectives of this study are to establish fault diagnostic and TS(thermal shield), and to develop a data acquisition and signal processing software system. In the first year of this study, an analysis technique for the reactor internal vibration using the reactor noise was proposed. With the technique proposed and the reactor noise signals (ex-core neutron and acceleration), the dynamic characteristics of Ulchin-1 reactor internals were obtained, and compared with those of Tricastin-1 which is the prototype of Ulchin-1. In the second year, a PC-based expert system for reactor internals fault diagnosis is developed, which included data acquisition, signal processing, feature extraction function, and represented diagnostic knowledge by the IF-THEN rule. To know the effect of the faults, the reactor internals of Ulchin-1 is modeled using FEM and simulated with an artificial defect given in the hold-down spring. Trend in the dynamic characteristics of reactor internals is also observed during one fuel cycle to know the effect of boron concentration. 100 figs, 7 tabs, 18 refs. (Author).

  6. 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

  7. 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.

  8. [The latex agglutination with video digital registration: the enhancement of diagnostic significance of conventional technique].

    Science.gov (United States)

    Starovoĭtova, T A; Steriopolo, N A; Zaĭko, V V; Vengerov, Iu Iu

    2012-02-01

    The rapid semiquantitative latex-tests, because of their analytic characteristics and convenient application, became widespread in the practice of laboratory diagnostics. Though, in spite of high sensitivity and specificity, their diagnostic effectiveness is lower that it could be mainly because of the impossibility to document the results of latex agglutinative re4actions and to manage the objective quality control. The application of systems of video digital registration permits to enhance the clinical significance of these analyses. By means of scanner systems (control and program complex "Expert Lab") the image of analytic objects is received with the results of latex agglutination reaction. The application of program techniques (the programs "Expert Lab - Agglutination" and "Expert Lab - Agglutination - Micros") in data processing permits to get the precise qualitative characteristics of active reactions, to ensure the automatic interpretation of results and gives an opportunity to proceed with the internal laboratory quality control. The saving of analytic object image in computer memory after termination of reaction favors the formation of data base, the implementation of retrospective evaluation of obtained results, additional consultations in dubious cases, including on-line. The application of complex "Expert Lab" permitted to develop the miniaturizes matrix systems permitting to decrease the withdrawal of latex reagents, to increase the productivity of analytical stage of operation preserving all analytical characteristics of method.

  9. 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.

  10. Non-invasive diagnostic techniques in the diagnosis of squamous cell carcinoma.

    Science.gov (United States)

    Warszawik-Hendzel, Olga; Olszewska, Małgorzata; Maj, Małgorzata; Rakowska, Adriana; Czuwara, Joanna; Rudnicka, Lidia

    2015-12-31

    Squamous cell carcinoma is the second most common cutaneous malignancy after basal cell carcinoma. Although the gold standard of diagnosis for squamous cell carcinoma is biopsy followed by histopathology evaluation, optical non-invasive diagnostic tools have obtained increased attention. Dermoscopy has become one of the basic diagnostic methods in clinical practice. The most common dermoscopic features of squamous cell carcinoma include clustered vascular pattern, glomerular vessels and hyperkeratosis. Under reflectance confocal microscopy, squamous cell carcinoma shows an atypical honeycomb or disarranged pattern of the spinous-granular layer of the epidermis, round nucleated bright cells in the epidermis and round vessels in the dermis. High frequency ultrasound and optical coherence tomography may be helpful in predominantly in pre-surgical evaluation of tumor size. Emerging non-invasive or minimal invasive techniques with possible application in the diagnosis of squamous cell carcinoma of the skin, lip, oral mucosa, vulva or other tissues include high-definition optical coherence tomography, in vivo multiphoton tomography, direct oral microscopy, electrical impedance spectroscopy, fluorescence spectroscopy, Raman spectroscopy, elastic scattering spectroscopy, differential path-length spectroscopy, nuclear magnetic resonance spectroscopy, and angle-resolved low coherence interferometry.

  11. 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.

  12. Piriformis syndrome: implications of anatomical variations, diagnostic techniques, and treatment options.

    Science.gov (United States)

    Cassidy, Lindsey; Walters, Andrew; Bubb, Kathleen; Shoja, Mohammadali M; Tubbs, R Shane; Loukas, Marios

    2012-08-01

    Details of piriformis syndrome, including the proper diagnosis and most effective form of treatment, continue to be controversial. While the cause, diagnosis, and treatment of piriformis syndrome remain elusive, many studies have been conducted to investigate newly developed diagnostic techniques as well as various treatment options for piriformis-induced sciatica. Despite the quantity of literature, few studies have demonstrated statistically significant results that support one form of treatment over another. Thus, despite the evidence supporting the newer treatment methodologies for piriformis syndrome, research should continue. It is important not only to evaluate treatment outcomes based on associated pain relief, but also to investigate the functional and anatomical return that patients experience from these studied treatments in order to fully explore the most effective form of therapy for piriformis syndrome.

  13. Advanced microscopic and histochemical techniques: diagnostic tools in the molecular era of myology

    Directory of Open Access Journals (Sweden)

    G Meola

    2009-06-01

    Full Text Available Over the past two centuries, myology (i.e. the basic and clinical science of muscle and muscle disease has passed through 3 stages of development: the classical period, the modern stage and the molecular era. The classical period spans the last part of nineteenth century and the earlier part of the twentieth century. During this time, several major muscle disease were clinically and pathologically characterized, including Duchenne muscular dystrophy (DMD, myotonic dystrophy (DM and facioscapulohumeral dystrophy (FSHD. The modern stage in the second half of the twentieth century is characterized by the adaptation of histo and cytochemical techniques to the study of muscle biopsies. These tools improved the diagnostic accuracy and made possible the identification of new changes and structures (Engel and Cunningham, 1963; Scarlato, 1975.

  14. Reducing beam shaper alignment complexity: diagnostic techniques for alignment and tuning

    Science.gov (United States)

    Lizotte, Todd E.

    2011-10-01

    Safe and efficient optical alignment is a critical requirement for industrial laser systems used in a high volume manufacturing environment. Of specific interest is the development of techniques to align beam shaping optics within a beam line; having the ability to instantly verify by a qualitative means that each element is in its proper position as the beam shaper module is being aligned. There is a need to reduce these types of alignment techniques down to a level where even a newbie to optical alignment will be able to complete the task. Couple this alignment need with the fact that most laser system manufacturers ship their products worldwide and the introduction of a new set of variables including cultural and language barriers, makes this a top priority for manufacturers. Tools and methodologies for alignment of complex optical systems need to be able to cross these barriers to ensure the highest degree of up time and reduce the cost of maintenance on the production floor. Customers worldwide, who purchase production laser equipment, understand that the majority of costs to a manufacturing facility is spent on system maintenance and is typically the largest single controllable expenditure in a production plant. This desire to reduce costs is driving the trend these days towards predictive and proactive, not reactive maintenance of laser based optical beam delivery systems [10]. With proper diagnostic tools, laser system developers can develop proactive approaches to reduce system down time, safe guard operational performance and reduce premature or catastrophic optics failures. Obviously analytical data will provide quantifiable performance standards which are more precise than qualitative standards, but each have a role in determining overall optical system performance [10]. This paper will discuss the use of film and fluorescent mirror devices as diagnostic tools for beam shaper module alignment off line or in-situ. The paper will also provide an overview

  15. 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

  16. 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.

  17. Infrared Thermography-based Biophotonics: Integrated Diagnostic Technique for Systemic Reaction Monitoring

    Science.gov (United States)

    Vainer, Boris G.; Morozov, Vitaly V.

    A peculiar branch of biophotonics is a measurement, visualisation and quantitative analysis of infrared (IR) radiation emitted from living object surfaces. Focal plane array (FPA)-based IR cameras make it possible to realize in medicine the so called interventional infrared thermal diagnostics. An integrated technique aimed at the advancement of this new approach in biomedical science and practice is described in the paper. The assembled system includes a high-performance short-wave (2.45-3.05 μm) or long-wave (8-14 μm) IR camera, two laser Doppler flowmeters (LDF) and additional equipment and complementary facilities implementing the monitoring of human cardiovascular status. All these means operate synchronously. It is first ascertained the relationship between infrared thermography (IRT) and LDF data in humans in regard to their systemic cardiovascular reactivity. Blood supply real-time dynamics in a narcotized patient is first visualized and quantitatively represented during surgery in order to observe how the general hyperoxia influences thermoregulatory mechanisms; an abrupt increase in temperature of the upper limb is observed using IRT. It is outlined that the IRT-based integrated technique may act as a take-off runway leading to elaboration of informative new methods directly applicable to medicine and biomedical sciences.

  18. 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.

  19. Extending battery life: A low-cost practical diagnostic technique for lithium-ion batteries

    Science.gov (United States)

    Merla, Yu; Wu, Billy; Yufit, Vladimir; Brandon, Nigel P.; Martinez-Botas, Ricardo F.; Offer, Gregory J.

    2016-11-01

    Modern applications of lithium-ion batteries such as smartphones, hybrid & electric vehicles and grid scale electricity storage demand long lifetime and high performance which typically makes them the limiting factor in a system. Understanding the state-of-health during operation is important in order to optimise for long term durability and performance. However, this requires accurate in-operando diagnostic techniques that are cost effective and practical. We present a novel diagnosis method based upon differential thermal voltammetry demonstrated on a battery pack made from commercial lithium-ion cells where one cell was deliberately aged prior to experiment. The cells were in parallel whilst being thermally managed with forced air convection. We show for the first time, a diagnosis method capable of quantitatively determining the state-of-health of four cells simultaneously by only using temperature and voltage readings for both charge and discharge. Measurements are achieved using low-cost thermocouples and a single voltage measurement at a frequency of 1 Hz, demonstrating the feasibility of implementing this approach on real world battery management systems. The technique could be particularly useful under charge when constant current or constant power is common, this therefore should be of significant interest to all lithium-ion battery users.

  20. Antenna toolkit

    CERN Document Server

    Carr, Joseph

    2006-01-01

    Joe Carr has provided radio amateurs and short-wave listeners with the definitive design guide for sending and receiving radio signals with Antenna Toolkit 2nd edition.Together with the powerful suite of CD software, the reader will have a complete solution for constructing or using an antenna - bar the actual hardware! The software provides a simple Windows-based aid to carrying out the design calculations at the heart of successful antenna design. All the user needs to do is select the antenna type and set the frequency - a much more fun and less error prone method than using a con

  1. Current practices of diagnostic techniques requiring 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 gonioscopy 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

  2. Epidemiology of intestinal parasitosis in Italy between 2005 and 2008: diagnostic techniques and methodologies

    Directory of Open Access Journals (Sweden)

    Daniele Crotti

    2013-04-01

    Full Text Available Aim of the study was to keep a real and actual photo relating to 2005-2008 regarding to diagnostic techniques and methodologies for intestinal parasites; so it would be possible to know specific epidemiology and suggest more rational and efficacious guide-lines. All members of AMCLI were involved in the proposal of a retrospective study regarding bowel parasites, helminths and protozoa.To engaged laboratories we asked how O&P was performed, if a specifical research for E. vermicularis and S. stercoralis was performed, if for the identification of D. fragilis, Entamoeba histolytica/dispar and Cryptosporidum spp were performed recommended specific permanent stains. 23 laboratories gave assent; but for an inferior number was possible to use the data for analysis and evaluation. Relating O&P only some laboratories performed permanent stains: Giemsa for D. fragilis, antigen and/or Trichrome stain for E. histolytica/dispar, antigen and/or acid fast stain for Cryptosporidium spp.Not all laboratories research specifically S. stercoralis. So the epidemiology is differentiated and related more to adequate or not adequate techniques than cohorts of examined populations. The overall positivity for parasites ranged from 0% to18.7%,for protozoa (pathogens or not were from 0% to 14.7%; for nematodes from 0% to 3.7%; for cestodes from 0% to 1.0%; for trematodes from 0% to 1.0%.Among helminths, E. vermicularis, followed by S. stercoralis, also in O&P, is the most frequent.The specific research of S. stercoralis gave a positivity from 0% to 33.3%; the cellophane tape test was positive for E. vermicularis from 0% fo 21.9% of cases.Among pathogen protozoa, D. fragilis, when permanent stain were applied, prevailed from 0% to 16.6%; G. duodenalis from 0.8% to 4.3%; E. histolytica/dispar, using a permanent stain or research of antigen, was identified from 0% to 20.6%. Coccidia were very rare, with Cryptosporidium spp observed from 0% to 5.2%. These are our conclusions

  3. Antennas in matter: Fundamentals, theory, and applications

    Science.gov (United States)

    King, R. W. P.; Smith, G. S.; Owens, M.; Wu, T. T.

    1981-01-01

    The volume provides an introduction to antennas and probes embedded within or near material bodies such as the earth, the ocean, or a living organism. After a fundamental analysis of insulated and bare antennas, an advanced treatment of antennas in various media is presented, including a detailed study of the electromagnetic equations in homogeneous isotropic media, the complete theory of the bare dipole in a general medium, and a rigorous analysis of the insulated antenna as well as bare and insulated loop antennas. Finally, experimental models and measuring techniques related to antennas and probes in a general dissipative or dielectric medium are examined.

  4. Some Recent Developments of Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    Yong Liu

    2012-01-01

    Full Text Available Although the microstrip antenna has been extensively studied in the past few decades as one of the standard planar antennas, it still has a huge potential for further developments. The paper suggests three areas for further research based on our previous works on microstrip antenna elements and arrays. One is exploring the variety of microstrip antenna topologies to meet the desired requirement such as ultrawide band (UWB, high gain, miniaturization, circular polarization, multipolarized, and so on. Another is to apply microstrip antenna to form composite antenna which is more potent than the individual antenna. The last is growing towards highly integration of antenna/array and feeding network or operating at relatively high frequencies, like sub-millimeter wave or terahertz (THz wave regime, by using the advanced machining techniques. To support our points of view, some examples of antennas developed in our group are presented and discussed.

  5. 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.

  6. The development of malaria diagnostic techniques: a review of the approaches with focus on dielectrophoretic and magnetophoretic methods.

    Science.gov (United States)

    Kasetsirikul, Surasak; Buranapong, Jirayut; Srituravanich, Werayut; Kaewthamasorn, Morakot; Pimpin, Alongkorn

    2016-07-12

    The large number of deaths caused by malaria each year has increased interest in the development of effective malaria diagnoses. At the early-stage of infection, patients show non-specific symptoms or are asymptomatic, which makes it difficult for clinical diagnosis, especially in non-endemic areas. Alternative diagnostic methods that are timely and effective are required to identify infections, particularly in field settings. This article reviews conventional malaria diagnostic methods together with recently developed techniques for both malaria detection and infected erythrocyte separation. Although many alternative techniques have recently been proposed and studied, dielectrophoretic and magnetophoretic approaches are among the promising new techniques due to their high specificity for malaria parasite-infected red blood cells. The two approaches are discussed in detail, including their principles, types, applications and limitations. In addition, other recently developed techniques, such as cell deformability and morphology, are also overviewed in this article.

  7. Mini-FLOTAC, an innovative direct diagnostic technique for intestinal parasitic infections: experience from the field.

    Directory of Open Access Journals (Sweden)

    Beatrice Divina Barda

    Full Text Available BACKGROUND: Soil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini-FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings. METHODOLOGY/PRINCIPAL FINDINGS: The study was carried out in Dharamsala, Himachal Pradesh, India, and in Bukumbi, Tanzania. A total of 180 pupils from two primary schools had their stool analyzed (n = 80 in Dharamsala and n = 100 in Bukumbi for intestinal parasitic infections with three diagnostic methods: direct fecal smear, formol-ether concentration method (FECM and mini-FLOTAC. Overall, 72% of the pupils were positive for any intestinal parasitic infection, 24% carried dual infections and 11% three infections or more. The most frequently encountered intestinal parasites were Entamoeba coli, Entamoeba histolytica/dispar, Giardia intestinalis, hookworm, (and Schistosoma mansoni, in Tanzania. Statistically significant differences were found in the detection of parasitic infections among the three methods: mini-FLOTAC was the most sensitive method for helminth infections (90% mini-FLOTAC, 60% FECM, and 30% direct fecal smear, whereas FECM was most sensitive for intestinal protozoa infections (88% FECM, 70% direct fecal smear, and 68% mini-FLOTAC. CONCLUSION/SIGNIFICANCE: We present the first experiences with the mini-FLOTAC for the diagnosis of intestinal helminths and protozoa. Our results suggest that it is a valid, sensitive and potentially low-cost alternative technique that could be used in resource-limited settings--particularly for helminth diagnosis.

  8. 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.

  9. Fungal disease detection in plants: Traditional assays, novel diagnostic techniques and biosensors.

    Science.gov (United States)

    Ray, Monalisa; Ray, Asit; Dash, Swagatika; Mishra, Abtar; Achary, K Gopinath; Nayak, Sanghamitra; Singh, Shikha

    2017-01-15

    Fungal diseases in commercially important plants results in a significant reduction in both quality and yield, often leading to the loss of an entire plant. In order to minimize the losses, it is essential to detect and identify the pathogens at an early stage. Early detection and accurate identification of pathogens can control the spread of infection. The present article provides a comprehensive overview of conventional methods, current trends and advances in fungal pathogen detection with an emphasis on biosensors. Traditional techniques are the "gold standard" in fungal detection which relies on symptoms, culture-based, morphological observation and biochemical identifications. In recent times, with the advancement of biotechnology, molecular and immunological approaches have revolutionized fungal disease detection. But the drawback lies in the fact that these methods require specific and expensive equipments. Thus, there is an urgent need for rapid, reliable, sensitive, cost effective and easy to use diagnostic methods for fungal pathogen detection. Biosensors would become a promising and attractive alternative, but they still have to be subjected to some modifications, improvements and proper validation for on-field use.

  10. 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.).

  11. Characterisation of the properties of a negative hydrogen ion beam by several beam diagnostic techniques

    Science.gov (United States)

    Maurizio, R.; Fantz, U.; Bonomo, F.; Serianni, G.

    2016-06-01

    The beam properties of the BATMAN negative ion source, which is the prototype of one module of the source for the ITER neutral beam injection system, are characterised by means of three diagnostic techniques: beam emission spectroscopy (BES), the experimental calorimeter mini-STRIKE and a copper calorimeter. The main beam parameters—beam divergence, homogeneity and top-bottom asymmetries—are studied in different operational scenarios: with different magnetic filter field setups, source settings and with different gases (hydrogen or deuterium). Among all dependences, the influence of the magnetic field configuration on the beam and the evolution of the beam features during some conditioning days are investigated in detail. Data show that the stronger the filter field in the beam region, the higher the beam top-bottom asymmetry—likely a v× B effect. During the conditioning of the source, such vertical beam asymmetry increases as well, suggesting an inhomogeneous H -production at the first grid of the extraction system.

  12. 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

  13. Notch Antennas

    Science.gov (United States)

    Lee, Richard Q.

    2004-01-01

    Notch antennas, also known as the tapered slot antenna (TSA), have been the topics of research for decades. TSA has demonstrated multi-octave bandwidth, moderate gain (7 to 10 dB), and symmetric E- and H- plane beam patterns and can be used for many different applications. This chapter summarizes the research activities on notch antennas over the past decade with emphasis on their most recent advances and applications. This chapter begins with some discussions on the designs of single TSA; then follows with detailed discussions of issues associated with TSA designs and performance characteristics. To conclude the chapter, some recent developments in TSA arrays and their applications are highlighted.

  14. 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.

  15. 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...

  16. Kinematic Measures during a Clinical Diagnostic Technique for Human Neck Disorder: Inter- and Intraexaminer Comparisons

    Directory of Open Access Journals (Sweden)

    Joseph Vorro

    2013-01-01

    Full Text Available Diagnoses of human musculoskeletal dysfunction of the cervical spine are indicated by palpable clues of a patient’s structural compliance/noncompliance as this body segment responds to diagnostic motion demands applied by a clinician. This process includes assessments of motion range, motion performance, and changes in tissue responses. However, biomechanical quantification of these diagnostic actions and their reproducible components is lacking. As a result, this study sought to use objective kinematic measures to capture aspects of the diagnostic process to compare inter- and intraexaminer motion behaviors when performing a specific clinical diagnostic protocol. Pain-free volunteers and a group determined to be symptomatic based on a psychometric pain score were examined by two clinicians while three-dimensional kinematic data were collected. Intraexaminer diagnostic motion ranges of cervical lateral flexion and secondary rotations were consistent for each examiner and for each subject group. However, interexaminer comparisons for motion range, secondary rotations, and average velocities yielded consistently larger measures for one examiner for both subject groups (P<0.05. This research demonstrates that fundamental aspects of the clinical diagnostic process for human neck disorders can be identified and measured using kinematic parameters. Further, these objective data have the potential to be linked to clinical decision making.

  17. Multifrequency Printed Antennas Loaded with Metamaterial Particles

    Directory of Open Access Journals (Sweden)

    D. Segovia-Vargas

    2009-06-01

    Full Text Available This paper provides a review of printed antennas loaded with metamaterial particles. This novel technique allows developing printed antennas with interesting features such as multifrequency (simultaneous operation over two or more frequency bands and multifunctionality (e. g. radiation pattern diversity. Moreover, compactness is also achieved and the main advantages of conventional printed antennas (light weight, low profile, low cost ... are maintained. Different types of metamaterial-loaded printed antennas are reviewed: printed dipoles and patch antennas. Several prototypes are designed, manufactured and measured showing good results. Furthermore, simple but accurate equivalent models are proposed. These models allow an easy and quick design of metamaterial-loaded printed antennas. Finally, two interesting applications based on the proposed antennas are reviewed: the patch antennas are used as radiating elements of emerging active RFID systems in the microwave band and the metamaterial-loaded printed dipoles are employed to increase the performance of log-periodic arrays.

  18. Development of a diagnostic technique based on Cherenkov effect for measurements of fast electrons in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Plyusnin, V. V.; Duarte, P.; Fernandes, H.; Silva, C. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, L.; Zebrowski, J.; Malinowski, K.; Rabinski, M.; Sadowski, M. J. [National Centre for Nuclear Research (NCBJ), 7 Andrzeja Soltana Str., 05-400 Otwock (Poland)

    2012-08-15

    A diagnostic technique based on the Cherenkov effect is proposed for detection and characterization of fast (super-thermal and runaway) electrons in fusion devices. The detectors of Cherenkov radiation have been specially designed for measurements in the ISTTOK tokamak. Properties of several materials have been studied to determine the most appropriate one to be used as a radiator of Cherenkov emission in the detector. This technique has enabled the detection of energetic electrons (70 keV and higher) and the determination of their spatial and temporal variations in the ISTTOK discharges. Measurement of hard x-ray emission has also been carried out in experiments for validation of the measuring capabilities of the Cherenkov-type detector and a high correlation was found between the data of both diagnostics. A reasonable agreement was found between experimental data and the results of numerical modeling of the runaway electron generation in ISTTOK.

  19. 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.

  20. The Diagnostic Challenge Competition: Probabilistic Techniques for Fault Diagnosis in Electrical Power Systems

    Science.gov (United States)

    Ricks, Brian W.; Mengshoel, Ole J.

    2009-01-01

    Reliable systems health management is an important research area of NASA. A health management system that can accurately and quickly diagnose faults in various on-board systems of a vehicle will play a key role in the success of current and future NASA missions. We introduce in this paper the ProDiagnose algorithm, a diagnostic algorithm that uses a probabilistic approach, accomplished with Bayesian Network models compiled to Arithmetic Circuits, to diagnose these systems. We describe the ProDiagnose algorithm, how it works, and the probabilistic models involved. We show by experimentation on two Electrical Power Systems based on the ADAPT testbed, used in the Diagnostic Challenge Competition (DX 09), that ProDiagnose can produce results with over 96% accuracy and less than 1 second mean diagnostic time.

  1. 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

  2. Diagnostics of glass fiber reinforced polymers and comparative analysis of their fabrication techniques with the use of acoustic emission

    Science.gov (United States)

    Bashkov, O. V.; Bryansky, A. A.; Panin, S. V.; Zaikov, V. I.

    2016-11-01

    Strength properties of the glass fiber reinforced polymers (GFRP) fabricated by vacuum and vacuum autoclave molding techniques were analyzed. Measurements of porosity of the GFRP parts manufactured by various molding techniques were conducted with the help of optical microscopy. On the basis of experimental data obtained by means of acoustic emission hardware/software setup, the technique for running diagnostics and forecasting the bearing capacity of polymeric composite materials based on the result of three-point bending tests has been developed. The operation principle of the technique is underlined by the evaluation of the power function index change which takes place on the dependence of the total acoustic emission counts versus the loading stress.

  3. 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

  4. 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

    . METHODS: Aspirates from 47 patients who had possible malignant infiltrates identified on computed tomography scans of the chest were included. Smears were stained by May-Grunwald-Giemsa and Diff-Quick for diagnostic purposes. CS material was obtained by gently scraping cells off the slides. Clots were...

  5. 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.

  6. THE TECHNIQUE OF DIAGNOSTICS OF THE PRODUCTION CAPACITY OF THE ORGANIZATION

    Directory of Open Access Journals (Sweden)

    E. S. Popova

    2014-01-01

    Full Text Available In the article due to the need for diagnostics of the production capacity of the organization. Formed methodological framework for evaluating the production potential of the organization. Research capacity will also enable the organization to timely respond to current changes. A classification of types of diagnostics of the production capacity of the organization according to the following criteria: timing, goals, content, purpose results. The article discusses the economic and organizational diagnosis of the production capacity of the organization. Economic diagnosis is based on the calculation of indicators of use of resources of the organization. Organizational diagnosis assesses the security of the organization's activities. Diagnosis productive capacity is the basis for improvement of the organization's activities. Defined diagnostics of the production capacity of the organization. Justified the selection stages of the research production potential. The first stage is the preliminary diagnosis. The second stage provides for the rapid diagnosis of production potential. At the third stage it is advisable to perform problem diagnosis. Problem diagnosis consists of economic and organizational diagnosis. Economic diagnosis assesses the state of the elements of the production potential of the organization. Organizational diagnostics analyses provide productive capacity. The fourth stage is represented by the solution of the problems of utilization of production capacity. Each stage is considered, has its content and specific diagnostic methods of production potential. This method allows determining the state of the elements, the efficiency of utilization of production capacity. The estimation of the production potential is based on the application of utility theory. This assessment provides a definition of the criteria and the scale of usefulness. This will allow you to measure the production potential numerically. In the end, it is revealed

  7. 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

  8. 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.

  9. 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

  10. A mathematical model of penile vascular dysfunction and its application to a new diagnostic technique.

    Science.gov (United States)

    Barnea, Ofer; Hayun, Shimon; Gillon, Gabriel

    2007-04-01

    A noninvasive diagnostic device was developed to assess the vascular origin and severity of penile dysfunction. It was designed and studied using both a mathematical model of penile hemodynamics and preliminary experiments on healthy young volunteers. The device is based on the application of an external pressure (or vacuum) perturbation to the penis following the induction of erection. The rate of volume change while the penis returns to its natural condition is measured using a noninvasive system that includes a volume measurement mechanism that has very low friction, thereby not affecting the measured system. The rate of volume change (net flow) is obtained and analyzed. Simulations using a mathematical model show that the device is capable of differentiating between arterial insufficiency and venous leak and indicate the severity of each. In preliminary measurements on young healthy volunteers, the feasibility of the measurement has been demonstrated. More studies are required to confirm the diagnostic value of the measurements.

  11. 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

  12. [Will the new molecular karyotyping BACs-on-Beads technique replace the traditional cytogenetic prenatal diagnostics? Preliminary reports].

    Science.gov (United States)

    Piotrowski, Krzysztof; Henkelman, Małgorzata; Zajaczek, Stanisław

    2012-04-01

    Recently several attempts have been made to introduce molecular karyotyping techniques into prenatal diagnosis. These methods can be used not only for the diagnosis of classical aneuploidies, but first of all they should be employed in the diagnostics of microaberrations, which are not revealed by low resolution methods of classical cytogenetics. The new method BACs-on-Beads is designed for quick detection of broad panel of aneuploidies and microdeletions, by the specified detection of deletions and duplications in the examined fetal DNA acquired from amniocytes. Prenatal diagnostics was performed with the use of BACs-on-Beads and classical amniocyte karyotyping simultaneously in a group of 54 pregnancies. This new method proved to be fully compatible with typical karyotyping in cultures of amniocytes in 98.2%. It was confirmed that the main advantage of this method is the possibility of quick diagnosis, within 48 hours, with much wider spectrum of detected anomalies when compared to classical methods. Contrary to other molecular karyotyping methods, the BACs-on-Beads technique is more economical, less time consuming and less complex equipment is needed than in case of other methods. We suppose that this technique can replace classical karyotyping methods in the near future.

  13. 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.

  14. Mutual coupling in MIMO antennas with transceiver separation

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

  15. 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。

  16. Superluminal antenna

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, John; Earley, Lawrence M.; Krawczyk, Frank L.; Potter, James M.; Romero, William P.; Wang, Zhi-Fu

    2017-03-28

    A superluminal antenna element integrates a balun element to better impedance match an input cable or waveguide to a dielectric radiator element, thus preventing stray reflections and consequent undesirable radiation. For example, a dielectric housing material can be used that has a cutout area. A cable can extend into the cutout area. A triangular conductor can function as an impedance transition. An additional cylindrical element functions as a sleeve balun to better impedance match the radiator element to the cable.

  17. 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.

  18. 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.

  19. [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.

  20. RF MEMS reconfigurable triangular patch antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Christodoulou, Christos George (The University of New Mexico, Albuquerque, NM); Nordquist, Christopher Daniel; Feldner, Lucas Matthew

    2005-07-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  1. RF MEMS reconfigurable triangular patch antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Nordquist, Christopher Daniel; Christodoulou, Christos George (University of New Mexico, Albuquerque, NM); Feldner, Lucas Matthew

    2005-01-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  2. A Novel Technique for Detecting Antibiotic-Resistant Typhoid from Rapid Diagnostic Tests

    OpenAIRE

    2015-01-01

    Fluoroquinolone-resistant typhoid is increasing. An antigen-detecting rapid diagnotic test (RDT) can rapidly diagnose typhoid from blood cultures. A simple, inexpensive molecular technique performed with DNA from positive RDTs accurately identified gyrA mutations consistent with phenotypic susceptibility testing results. Field diagnosis combined with centralized molecular resistance testing could improve typhoid management and surveillance in low-resource settings.

  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. 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

  5. Planar antenna system for direction finding

    Science.gov (United States)

    Mardale, Iulia-Cezara; Cocias, Gabriela; Dumitrascu, Ana; Tamas, Razvan; Berescu, Serban

    2015-02-01

    Applications of direction finding techniques include detection and localization of pulsed electromagnetic sources. This paper presents the design and analysis of a planar antenna system for direction finding. Our proposed system includes 4 hybrid couplers that generate 900 shifted signals, 2 crossover couplers also known as 0dB couplers, two 450 phase shifters, two 00 phase shifters and 4 patch antennas.

  6. Microstrip fractal-shaped antennas: a review

    OpenAIRE

    Anguera Pros, Jaume; Borja, C.; Puente Baliarda, Carles

    2007-01-01

    A review of electromagnetic features of microstrip antennas using fractal geometries is presented divided in four main areas: multi-frequency antennas, combination of multi- frequency with broadband techniques, high-directivity patches, and arrays with microstrip elements operating in localized modes Peer Reviewed

  7. 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...

  8. 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 ...

  9. Mobile satellite communications - Vehicle antenna technology update

    Science.gov (United States)

    Bell, D.; Naderi, F. M.

    1986-01-01

    This paper discusses options for vehicle antennas to be used in mobile satellite communications systems. Two types of antennas are identified. A non-steerable, azimuthally omnidirectional antenna with a modest gain of 3 to 5 dBi is suggested when a low cost is desired. Alternatively, mechanically or electronically steerable antennas with a higher gain of 10 to 12 dBi are suggested to alleviate power and spectrum scarcity associated with mobile satellite communications. For steerable antennas, both open-loop and closed-loop pointing schemes are discussed. Monopulse and sequential lobing are proposed for the mechanically steered and electronically steered antennas, respectively. This paper suggests a hybrid open-loop/closed-loop pointing technique as the best performer in the mobile satellite environment.

  10. 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.

  11. 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.

  12. 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)

  13. New imaging technique using degree of polarization for the study of polarimetric properties for non-invasive biomedical diagnostic

    Science.gov (United States)

    Buscemi, Isabella C.; Guyot, Steve; Lemoine, Jacques

    2012-06-01

    This research proposes a new imaging technique for near real time multispectral acquisition using CCD RGB cameras of the so called "Degree Of Polarization" (DOP) in polarimetry for future clinical investigation. The aim of exploiting the DOP as the contrast element is to demonstrate that the elliptical DOP provides more information characterizing complex medium than the more traditional linear and circular ones. The system considers an incoherent input white light beam and opportunely calibrated nematic crystals (LCVR), so no mechanical tools are necessary. The particular features of the system indicate it to be the perfect candidate for a new imaging system considering in-vivo (as well as ex-vivo) non invasive superficial diagnostic for medical application as dermatologic diagnostics, since no type of sample preparation is necessary, i.e. tissue biopsy, radiation or contrast agent injection. Thus the biomedical application of this method suggests a simple, direct, fast and also easily exploitable future employment, as a desirable mean for clinical investigation but also for digital recognition in biometrics. Further new elements to improve the model of light scattering and matter-light interaction will be acquired, in particular considering a very complete characterization of the system response using latex microspheres suspension to simulate turbid media with different concentration.

  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. Towards non-invasive diagnostic techniques for early detection of acute renal transplant rejection: A review

    Directory of Open Access Journals (Sweden)

    Elizabeth Hollis

    2017-03-01

    Full Text Available The kidney is a very important complicated filtering organ of the body. When the kidney reaches stage 5 chronic kidney disease, end stage renal failure, the preeminent therapy is renal transplantation. Although it is the best form of treatment, lack of kidney donors is still challenging. Therefore, all efforts should be employed to prolong the survival rate of the transplanted kidney. However, graft dysfunction (e.g., acute rejection is one of the serious barriers to long term kidney transplant survival. Currently, graft dysfunction’s gold standard of diagnosis is renal biopsy. Although renal biopsy is helpful, it is not preferred due to its invasive nature, high morbidity rates, and expensiveness. Therefore, noninvasive imaging techniques have become the subject of extensive research and interest, giving a strong promise to replace, or at least to decrease, biopsy usage in diagnosing graft dysfunction. This survey will discuss not only the current diagnosis and treatment of graft dysfunction but also the state-of-the-art imaging techniques in detecting acute renal transplant rejection.

  16. Comparison of different diagnostic techniques for the detection of cryptosporidiosis in bovines

    Directory of Open Access Journals (Sweden)

    H. K. M. Rekha

    2016-02-01

    Full Text Available Aim: Aim of the present study was to compare different methods, viz., Sheather’s sugar flotation (SSF, Ziehl-Neelsen (ZN, Kinyoun’s acid-fast method (KAF, safranin-methylene blue staining (SMB, and negative staining techniques such as nigrosin staining, light green staining, and malachite green staining for the detection of Cryptosporidium spp. oocysts in bovines. Materials and Methods: A total of 455 fecal samples from bovines were collected from private, government farms and from the clinical cases presented to Department of Medicine, Veterinary College, Bengaluru. They were subjected for SSF, ZN, KAF, SMB and negative staining methods. Results: Out of 455 animal fecal samples screened 5.71% were found positive for Cryptosporidium spp. oocysts. The species were identified as Cryptosporidium parvum in calves and Cryptosporidium andersoni in adults based on the morphological characterization and micrometry of the oocysts. Conclusions: Of all the techniques, fecal flotation with sheather’s was found to be more specific and sensitive method for the detection of Cryptosporidium spp. oocysts. Among the conventional staining methods, the SMB gives better differentiation between oocysts and yeast. Among the three negative staining methods, malachite green was found sensitive over the other methods.

  17. 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.

  18. An evaluation of diagnostic techniques utilized in the initial workup of pediatric patients with acute lymphocytic leukemia.

    Science.gov (United States)

    Kuntz, D J; Leonard, J C; Nitschke, R M; Vanhoutte, J J; Wilson, D A; Basmadjian, G P

    1984-07-01

    The records of 32 pediatric patients with acute lymphocytic leukemia (ALL) were reviewed to evaluate the role of various diagnostic techniques used to assess the extent of extramedullary disease. Our findings indicate that adequate screening for hepatosplenomegaly is obtained by clinical assessment and for bone and renal involvement by bone scintigraphy including concomitant renal imaging. We recommend that radiographs be restricted to scintigraphically abnormal areas and/or sites of bone pain. Liver-spleen scintigraphy, gallium studies, intravenous pyelography, and ultrasound studies of the abdomen and pelvis should be utilized only to answer specific clinical questions. Evaluation in this manner reduces both radiation exposure and patient expense, while it adequately defines the extent of disease in these organs.

  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. Reducing Redundancies in Reconfigurable Antenna Structures Using Graph Models

    Energy Technology Data Exchange (ETDEWEB)

    Costantine, Joseph; al-Saffar, Sinan; Christodoulou, Christos G.; Abdallah, Chaouki T.

    2010-04-23

    Many reconfigurable antennas have redundant components in their structures. In this paper we present an approach for reducing redundancies in reconfigurable antenna structures using graph models. We study reconfigurable antennas, which are grouped, categorized and modeled according to a set of proposed graph rules. Several examples are presented and discussed to demonstrate the validity of this new technique.

  1. Fuel Cell Manufacturing Diagnostic Techniques: IR Thermography with Reactive Flow through Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Manak, A. J.; Ulsh, M.; Bender, G.

    2012-01-01

    While design and material considerations for PEMFCs have a large impact on cost, it is also necessary to consider a transition to high volume production of fuel cell systems, including MEA components, to enable economies of scale and reduce per unit cost. One of the critical manufacturing tasks is developing and deploying techniques to provide in‐process measurement of fuel cell components for quality control. This effort requires a subsidiary task: The study of the effect of manufacturing defects on performance and durability with the objective to establish validated manufacturing tolerances for fuel cell components. This work focuses on the development of a potential quality control method for gas diffusion electrodes (GDEs). The method consists of infrared (IR) thermography combined with reactive flow through (RFT) excitation. Detection of catalyst loading reduction defects in GDE catalyst layers will be presented.

  2. MDR-TB screening in a setting with molecular diagnostic techniques: who got tested, who didn't and why?

    Science.gov (United States)

    Shewade, H D; Govindarajan, S; Sharath, B N; Tripathy, J P; Chinnakali, P; Kumar, A M V; Muthaiah, M; Vivekananda, K; Paulraj, A K; Roy, G

    2015-06-21

    Contexte : Programme national révisé de Lutte contre la Tuberculose, Pondichéry, Inde, avec une structure de techniques de diagnostic moléculaire.Objectif : Déterminer l'abandon préalable au diagnostic et préalable au traitement et leurs raisons parmi des patients présumés atteints de tuberculose multirésistante (TB-MDR).Méthodes : Dans cette étude utilisant plusieurs méthodes, l'élément quantitatif consistait en une analyse de cohorte rétrospective, grâce à une revue de dossiers, de tous les patients présumés atteints de TB-MDR entre octobre 2012 et septembre 2013. L'élément qualitatif incluait des entretiens approfondis avec des informateurs clés impliqués dans la gestion programmatique des services de TB pharmacorésistante.Résultats : Sur 341 patients présumés TB-MDR éligibles, le taux d'abandon avant le diagnostic et avant le traitement a été de 45,5% (155/341) et 29% (2/7), respectivement. Les patients atteints de TB extra-pulmonaire (RR = 2,3), de coïnfection par le virus de l'immunodéficience humaine et TB (RR = 1,7), inscrits entre octobre et décembre 2012 (RR = 1,3) et identifiés à partir de centres de santé primaires/secondaires (RR = 1,8) avaient moins de chances d'être testés. Les thèmes qui ont émergé lors de l'analyse des données qualitatives ont été « l'absence d'un mécanisme systématique de suivi des patients référés pour culture et test de pharmaco sensibilité », « l'absence de services de coursier pour transporter les crachats », « le manque de connaissances et d'appropriation du personnel de santé en général », « les ruptures de stock de kits de diagnostic » et « la non-adhérence du patient ».Conclusion : En dépit de l'introduction de techniques de diagnostic moléculaire, les problèmes opérationnels de dépistage de la TB-MDR restent préoccupants et requièrent une attention urgente.

  3. Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods

    Directory of Open Access Journals (Sweden)

    Barbosa JA

    2011-05-01

    Full Text Available José Augusto A Barbosa¹, Alexandre B Rodrigues¹, Cleonice Carvalho C Mota¹, Márcia M Barbosa², Ana C Simões e Silva¹¹Department of Pediatrics, Faculty of Medicine, Federal University of Minas Gerais (UFMG, Belo Horizonte, Minas Gerais, Brazil; ²Ecocenter, Socor Hospital, Belo Horizonte, Minas Gerais, BrazilAbstract: Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations.Keywords: cardiovascular risk, endothelium dysfunction, obesity, strain and strain rate, tissue Doppler

  4. 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.)

  5. Laser flash photolysis studies of atmospheric free radical chemistry using optical diagnostic techniques

    Science.gov (United States)

    Wine, Paul H.; Nicovich, J. M.; Hynes, Anthony J.; Stickel, Robert E.; Thorn, R. P.; Chin, Mian; Cronkhite, Jeffrey A.; Shackelford, Christie J.; Zhao, Zhizhong; Daykin, Edward P.

    1993-01-01

    Some recent studies carried out in our laboratory are described where laser flash photolytic production of reactant free radicals has been combined with reactant and/or product detection using time-resolved optical techniques to investigate the kinetics and mechanisms of important atmospheric chemical reactions. Discussed are (1) a study of the radical-radical reaction O + BrO yields Br + O2 where two photolysis lasers are employed to prepare the reaction mixture and where the reactants O and BrO are monitored simultaneously using atomic resonance fluorescence to detect O and multipass UV absorption to detect BrO; (2) a study of the reaction of atomic chlorine with dimethylsulfide (CH3SCH3) where atomic resonance fluorescence detection of Cl is employed to elucidate the kinetics and tunable diode laser absorption spectroscopy is employed to investigate the HCl product yield; and (3) a study of the aqueous phase chemistry of Cl2(-) radicals where longpath UV absorption spectroscopy is employed to investigate the kinetics of the Cl2(-) + H2O reaction.

  6. 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.

  7. 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.

  8. Optical antenna gain. I - Transmitting antennas

    Science.gov (United States)

    Klein, B. J.; Degnan, J. J.

    1974-01-01

    The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM-00 mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.

  9. Optical antenna gain. 1: transmitting antennas.

    Science.gov (United States)

    Klein, B J; Degnan, J J

    1974-09-01

    The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM(00) mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.

  10. Advanced system characterizes antennas to 65 GHz

    Science.gov (United States)

    Francis, Michael H.; Kremer, Douglas P.; Repjar, Andrew G.

    1990-03-01

    The antenna measurement service offered by the National Institute of Standards and Technology provides radiation-pattern, on-axis gain, and polarization measurements to 65 GHz using planar near-field and extrapolation techniques. It is pointed out that measurements of millimeter-wave antennas are both difficult and costly to make and that such measurements require low-noise, high-power signal sources and exceptionally stable and repeatable connections. The process of the three-antenna extrapolation technique and subsequent measurements of dual-port circularly polarized antennas and swept-frequency gain measurements are analyzed, and antenna standards are noted. Insertion-loss measurements and attenuator calibration are discussed, and measurement uncertainties and far-field patterns are analyzed.

  11. Identifying Students' Mathematical Skills from a Multiple-Choice Diagnostic Test Using an Iterative Technique to Minimise False Positives

    Science.gov (United States)

    Manning, S.; Dix, A.

    2008-01-01

    There is anecdotal evidence that a significant number of students studying computing related courses at degree level have difficulty with sub-GCE mathematics. Testing of students' skills is often performed using diagnostic tests and a number of computer-based diagnostic tests exist, which work, essentially, by testing one specific diagnostic skill…

  12. 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.

  13. Antenna Pattern Impact on MIMO OTA Testing

    DEFF Research Database (Denmark)

    Fan, Wei; Nielsen, Jesper Ødum; Franek, Ondrej

    2013-01-01

    This paper investigates the impact of the DUT antenna pattern on the test area performance for multi-probe based MIMO OTA setup in terms of received voltage and spatial correlation. The plane wave synthesis (PWS) technique has been proposed for vertical polarization in the literature, where...... the goal is to approximate plane waves with arbitrary directions. The received voltage at the antenna terminal depends on the antenna radiation pattern and the impinging plane waves. A novel closed form technique to reproduce the received voltage with arbitrary incoming plane waves based on trigonometric...... interpolation is presented. The proposed technique provides a closed form solution for the PWS when the probe ring radius is infinite. The proposed technique shows that the impact of the antenna pattern on the induced received voltage accuracy is ruled by Nyquist sampling theory. Furthermore, the impact...

  14. Antenna impedance matching with neural networks.

    Science.gov (United States)

    Hemminger, Thomas L

    2005-10-01

    Impedance matching between transmission lines and antennas is an important and fundamental concept in electromagnetic theory. One definition of antenna impedance is the resistance and reactance seen at the antenna terminals or the ratio of electric to magnetic fields at the input. The primary intent of this paper is real-time compensation for changes in the driving point impedance of an antenna due to frequency deviations. In general, the driving point impedance of an antenna or antenna array is computed by numerical methods such as the method of moments or similar techniques. Some configurations do lend themselves to analytical solutions, which will be the primary focus of this work. This paper employs a neural control system to match antenna feed lines to two common antennas during frequency sweeps. In practice, impedance matching is performed off-line with Smith charts or relatively complex formulas but they rarely perform optimally over a large bandwidth. There have been very few attempts to compensate for matching errors while the transmission system is in operation and most techniques have been targeted to a relatively small range of frequencies. The approach proposed here employs three small neural networks to perform real-time impedance matching over a broad range of frequencies during transmitter operation. Double stub tuners are being explored in this paper but the approach can certainly be applied to other methodologies. The ultimate purpose of this work is the development of an inexpensive microcontroller-based system.

  15. 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

  16. Optical design of the oblique Ece antenna system for JET

    Energy Technology Data Exchange (ETDEWEB)

    Sozzi, C. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy)]. E-mail: sozzi@ifp.cnr.it; Bruschi, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); Simonetto, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); DeLaLuna, E. [Asociacion EURATOM-CIEMAT, CIEMAT, Madrid (Spain); Fessey, J. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom); Riccardo, V. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom)

    2005-11-15

    Systematic disagreements between Ece and Thomson Scattering diagnostics observed in various fusion devices led to the proposal of the so called Oblique Ece diagnostics on JET. This system will allow the study of the electron distribution function at low energies to reveal deviations from the Maxwellian distribution. This paper is devoted to the design of the quasi optical antenna for this diagnostics. The physical bases of the diagnostics imply two lines of sight at about 10{sup o} and 20{sup o} respectively from the magnetic field gradient. Severe geometrical constraints are imposed by the location of the antenna. The design strategy and physical optics calculations used to validate it are presented.

  17. Flexible plasma linear antenna

    Science.gov (United States)

    Zhao, Jiansen; Wang, Shengzheng; Wu, Huafeng; Liu, Yue; Chang, Yongmeng; Chen, Xinqiang

    2017-02-01

    In this work, we introduce a type of plasma antenna that was fabricated using flexible materials and excited using a 5-20 kHz alternating current (ac) power supply. The results showed that the antenna characteristics, including the impedance, the reflection coefficient (S11), the radiation pattern, and the gain, can be controlled rapidly and easily by varying both the discharge parameters and the antenna shapes. The scope for reconfiguration is greatly enhanced when the antenna shape is changed from a monopole to a helix configuration. Additionally, the antenna polarization can also be adjusted by varying the antenna shapes.

  18. 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.

  19. 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)

  20. Impulse Testing of Corporate-Fed Patch Array Antennas

    Science.gov (United States)

    Chamberlain, Neil F.

    2011-01-01

    This paper discusses a novel method for detecting faults in antenna arrays. The method, termed Impulse Testing, was developed for corporate-fed patch arrays where the element is fed by a probe and is shorted at its center. Impulse Testing was devised to supplement conventional microwave measurements in order to quickly verify antenna integrity. The technique relies on exciting each antenna element in turn with a fast pulse (or impulse) that propagates through the feed network to the output port of the antenna. The resulting impulse response is characteristic of the path through the feed network. Using an oscilloscope, a simple amplitude measurement can be made to detect faults. A circuit model of the antenna elements and feed network was constructed to assess various fault scenarios and determine fault-detection thresholds. The experimental setup and impulse measurements for two patch array antennas are presented. Advantages and limitations of the technique are discussed along with applications to other antenna array topologies

  1. 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

  2. Isolation of High-Q Antennas for Mobile Handsets

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert Frølund

    2013-01-01

    Isolation, beween the antennas at low frequencies (700 MHz), is one of the major issues in 4th Generation Long Term Evolution. This paper presents a practical method to improve the isolation between the ports of Tx an Rx antennas through narrow-band antennas used in separate transmit and receive...... mode. Furthermore, a patented feeding technique is applied to feed the antenna, which helps improving the isolation between the antenna ports. An isolation of better than -22dB at 700 MHz, is shown to be possible to achieve, by utilizing this method....

  3. Antenna Structure Registrate

    Data.gov (United States)

    Department of Homeland Security — This file is an extract of the Antenna Structure Registrate (ASR). The ASR consists of antenna structures that are more than 60.96 meters (200 feet) in height or...

  4. Antenna Pattern Range (APR)

    Data.gov (United States)

    Federal Laboratory Consortium — TheAntenna Pattern Range (APR)features a non-metallic arch with a trolley to move the transmit antenna from the horizon to zenith. At the center of the ground plane,...

  5. Cross Resonant Optical Antenna

    Science.gov (United States)

    Biagioni, P.; Huang, J. S.; Duò, L.; Finazzi, M.; Hecht, B.

    2009-06-01

    We propose a novel cross resonant optical antenna consisting of two perpendicular nanosized gold dipole antennas with a common feed gap. We demonstrate that the cross antenna is able to convert propagating fields of any polarization state into correspondingly polarized, localized, and enhanced fields and vice versa. The cross antenna structure therefore opens the road towards the control of light-matter interactions based on polarized light as well as the analysis of polarized fields on the nanometer scale.

  6. Cross resonant optical antenna.

    Science.gov (United States)

    Biagioni, P; Huang, J S; Duò, L; Finazzi, M; Hecht, B

    2009-06-26

    We propose a novel cross resonant optical antenna consisting of two perpendicular nanosized gold dipole antennas with a common feed gap. We demonstrate that the cross antenna is able to convert propagating fields of any polarization state into correspondingly polarized, localized, and enhanced fields and vice versa. The cross antenna structure therefore opens the road towards the control of light-matter interactions based on polarized light as well as the analysis of polarized fields on the nanometer scale.

  7. Coherently combining antennas

    Science.gov (United States)

    Dybdal, Robert B. (Inventor); Curry, Samuel J. (Inventor)

    2009-01-01

    An apparatus includes antenna elements configured to receive a signal including pseudo-random code, and electronics configured to use the pseudo-random code to determine time delays of signals incident upon the antenna elements and to compensate the signals to coherently combine the antenna elements.

  8. Antenna Miniaturization in Complex Electromagnetic Environments

    DEFF Research Database (Denmark)

    Zhang, Jiaying

    Hearing-aids today constitute devices with an advanced technology, and wireless communication integrated into hearing-aids will introduce a range of completely new functionalities. The antenna is an important component in any wireless system, and the demand for compact wireless systems with strin......Hearing-aids today constitute devices with an advanced technology, and wireless communication integrated into hearing-aids will introduce a range of completely new functionalities. The antenna is an important component in any wireless system, and the demand for compact wireless systems...... improved compared to the 2-D planar electrically small loop antennas. Measurement Techniques for ESAs In this dissertation we proposed two novel measurement techniques for electrically small antennas. A modified Wheeler cap method for the radiation efficiency measurement of balanced electrically small....... Moreover, the modified Wheeler cap method for measurements of small antennas in complex environments is further developed. A cable-free impedance and gain measurement technique for electrically small antennas is also proposed. The electromagnetic model of this technique is derived by using the spherical...

  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. Antenna development for high field plasma imaging.

    Science.gov (United States)

    Kong, X; Domier, C W; Luhmann, N C

    2010-10-01

    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.

  11. 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.

  12. Prenatal Diagnosis Procedures and Techniques to Obtain a Diagnostic Fetal Specimen or Tissue: Maternal and Fetal Risks and Benefits.

    Science.gov (United States)

    Wilson, R Douglas; Gagnon, Alain; Audibert, François; Campagnolo, Carla; Carroll, June; Brock, Jo-Ann; Chong, Karen; Johnson, Jo-Ann; MacDonald, William; Okun, Nanette; Pastuck, Melanie; Vallee-Pouliot, Karine

    2015-07-01

    Objectif : Offrir aux fournisseurs de soins de maternité et à leurs patientes des lignes directrices factuelles contemporaines en ce qui concerne les services de counseling traitant des risques et des avantages maternels propres à la tenue des interventions diagnostiques prénatales orientées par échographie (et/ou des techniques permettant l’établissement d’un diagnostic génétique) nécessaires dans les cas où il a été établi pendant la période prénatale que la grossesse serait exposée à des risques, ainsi qu’en ce qui concerne la prise de décisions subséquentes quant à la prise en charge de la grossesse (questions abordant des aspects tels que le niveau du fournisseur de soins obstétricaux, la surveillance prénatale, le lieu où devraient se dérouler les soins et l’accouchement, et la décision de poursuivre ou d’interrompre la grossesse). La présente directive clinique se limite aux services de counseling traitant des risques et des avantages maternels, et aux décisions en matière de prise en charge de la grossesse pour les femmes qui nécessitent (ou qui envisagent) la mise en œuvre d’une intervention ou d’une technique effractive orientée par échographie aux fins de l’établissement d’un diagnostic prénatal. Population de patientes : Femmes enceintes identifiées, à la suite de la mise en œuvre de protocoles établis de dépistage prénatal (taux sériques maternels ± imagerie, résultats d’analyse de l’ADN acellulaire indiquant des risques élevés, résultats anormaux au moment de l’imagerie fœtale diagnostique ou antécédents familiaux de troubles héréditaires), comme étant exposées à un risque accru d’anomalie génétique fœtale. Ces femmes pourraient nécessiter ou demander des services de counseling au sujet des risques et des avantages pour la grossesse de la tenue d’une intervention effractive orientée par échographie visant à déterminer l’étiologie, le diagnostic, et/ou la

  13. Impedance Matching of Tapered Slot Antenna using a Dielectric Transformer

    Science.gov (United States)

    Simons, R. N.; Lee, R. Q.

    1998-01-01

    A new impedance matching technique for tapered slot antennas using a dielectric transformer is presented. The technique is demonstrated by measuring the input impedance, Voltage Standing Wave Ratio (VSWR) and the gain of a Vivaldi antenna (VA). Measured results at Ka-Band frequencies are presented and discussed.

  14. 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.

  15. A general purpose diagnostic technique for marine diesel engines - Application on the main propulsion and auxiliary diesel units of a marine vessel

    Energy Technology Data Exchange (ETDEWEB)

    Lamaris, V.T., E-mail: lamaris@central.ntua.g [Internal Combustion Engines Laboratory, Thermal Engineering Department, School of Mechanical Engineering, National Technical University of Athens, 9 Heroon Polytechniou St., Zografou Campus, 15780 Athens (Greece); Hountalas, D.T. [Internal Combustion Engines Laboratory, Thermal Engineering Department, School of Mechanical Engineering, National Technical University of Athens, 9 Heroon Polytechniou St., Zografou Campus, 15780 Athens (Greece)

    2010-04-15

    Diesel engines are widely used in marine applications (i.e. propulsion and auxiliaries) except from a few cases where gas or steam turbines are used. This is the result of their high efficiency, power concentration and reliability compared to other compatible or alternative power sources. The proper and efficient operation of the engines (main engine and diesel generator units) in marine applications is critical, and therefore techniques or systems that determine engine current condition and detect potential faults are extremely important. Furthermore, it is advantageous when such techniques can be applied on different engine configurations and provide reliable results, because on a vessel usually exist diesel engines of different type, i.e. the main propulsion unit is a large low-speed two-stroke diesel engine while the diesel generators are four-stroke medium or high speed engines. In the present work is described and evaluated for the first time the application of an improved diagnostic technique, developed by the authors, on both the main engine and the auxiliary units of a commercial marine vessel. The diagnostic technique is based on a thermodynamic simulation model. The simulation model embedded in the technique has been modified, namely an existing two-zone model is replaced by a multi-zone one. With this modification it is avoided model constant tuning with the operating conditions. This is extremely important for the diagnostic philosophy of the proposed technique. Using data from engine shop tests, the simulation model is calibrated (i.e. model constants are determined) and the engine reference condition is obtained. The simulation model is then used to estimate the current engine condition, using field measurements (i.e. cylinder pressure measurements, periphery data, etc.). From the results it is revealed that the diagnosis method provides detailed information for the operating condition of both engines and the values of parameters that cannot be

  16. 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.

  17. 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...... 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 significant thermal...... loss; at 1400 MHz nearly 2 dB are lost solely because of the copper conductivity. Thermal loss poses a limitation to achievable performance of tunable antennas and to antenna miniaturisation....

  18. 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

  19. Dielectrically Loaded Biconical Antennas

    Science.gov (United States)

    Nusseibeh, Fouad Ahmed

    1995-01-01

    Biconical antennas are of great interest to those who deal with broadband applications including the transmission/reception of pulses. In particular, wide-angle conical antennas are an attractive choice in many applications including Electronic Support Measures (ESM) and the measurements of transient surface currents and charge densities on aircraft. Dielectric loading in the interior region of a conical antenna can be used to reduce the size of the antenna especially at low frequencies and/or for structural strength. Therefore, having an analytical solution for the input impedance and the frequency response is very helpful in optimizing the design and understanding the behavior of the antenna. From the quasi-analytical solution for the input impedance and the electric field of a wide-angle conical antenna, it can be seen that the dielectric loading in the antenna region improves the input impedance at low frequencies, but increases the number of resonance points and the magnitude of these peaks. When an inhomogeneous dielectric load is used, the magnitude of the resonance peaks is decreased (depending on the way the load is distributed), improving the input impedance of the antenna significantly. Introducing a dielectric load in the interior region of an electrically short receiving cone makes the antenna behave as an electrically longer antenna. However, this is not true for the case for electrical1y long antennas. For the case of pulse transmission, the dielectric load affects only the amplitude. Of course, if the dielectric fills the whole space, both transmitting and receiving antennas behave as electrically longer antennas.

  20. Microstrip antennas in subsurface sensing

    Science.gov (United States)

    Volgyi, Ferenc

    2000-07-01

    This paper reviews the various applications of microstrip antennas with special emphasis on subsurface sensing, microwave moisture measurement and nondestructive testing of dielectric materials. With reference to the literature, we first describe the commonly used GPR-antennas, the printed Vivaldi-antennas, and microstrip antennas used in moisture content measurement. Furthermore, attention is given to the problems of new antenna technologies, showing examples for active integrated antennas, a photonic band gap patch antenna and a silicon micromachined patch antenna. The reminder of the paper summarizes relevant R&D activities in microstrip antennas at BUTE/DMT, focusing on near-field experiments, monitoring of particleboards and WLAN- applications of patch radiators.

  1. 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.

  2. 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)

  3. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2016-12-19

    The gain of an antenna can be enhanced through the integration of a lens, however this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, with a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB giving a peak gain of about 12.9 dBi at 8.8 GHz.

  4. 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

    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 (SSF...

  5. 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.

  6. A Broadband and High Gain Tapered Slot Antenna for W-Band Imaging Array Applications

    Directory of Open Access Journals (Sweden)

    Dong Sik Woo

    2014-01-01

    Full Text Available A broadband and high gain tapered slot antenna (TSA by utilizing a broadband microstrip- (MS- to-coplanar stripline (CPS balun has been developed for millimeter-wave imaging systems and sensors. This antenna exhibits ultrawideband performance for frequency ranges from 70 to over 110 GHz with the high antenna gain, low sidelobe levels, and narrow beamwidth. The validity of this antenna as imaging arrays is also demonstrated by analyzing mutual couplings and 4-element linear array. This antenna can be applied to mm-wave phased array, imaging array for plasma diagnostics applications.

  7. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  8. Antenna applications of superconductors

    Science.gov (United States)

    Hansen, R. C.

    1991-09-01

    The applicability of superconductors to antennas is examined. Potential implementations that are examined are superdirective arrays; electrically small antennas; tuning and matching of these two; high-gain millimeter-wavelength arrays; and kinetic inductance slow wave structures for array phasers and traveling wave array feeds. It is thought that superdirective arrays and small antennas will not benefit directly, but their tuning/matching networks will undergo major improvements. Miniaturization of antennas will not be aided, but much higher gain millimeter-wave arrays will be realizable. Kinetic inductance slow-wave lines appear advantageous for improved array phasers and time delay, as well as for traveling-wave array feeds.

  9. 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)

  10. Reliability of diagnostic imaging techniques in suspected acute appendicitis: proposed diagnostic protocol; Indicacion de las tecnicas de diagnostico por la imagen en la sospecha de apendicitis aguda: propuesta de protocolo diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Cura del, J. L.; Oleaga, L.; Grande, D.; Vela, A. C.; Ibanez, A. M. [Hospital de Basureto. Bilbao (Spain)

    2001-07-01

    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.

  11. Diagnosis of soil-transmitted helminths in the era of preventive chemotherapy: effect of multiple stool sampling and use of different diagnostic techniques.

    Directory of Open Access Journals (Sweden)

    Stefanie Knopp

    Full Text Available BACKGROUND: Soil-transmitted helminth infections are common throughout the tropics and subtropics and they disproportionately affect the poorest of the poor. In view of a growing global commitment to control soil-transmitted helminthiasis, there is a need to elucidate the effect of repeated stool sampling and the use of different diagnostic methods in areas targeted for preventive chemotherapy that are characterized by low-infection intensities. In this study, we focused on schoolchildren on Unguja Island, Zanzibar, an area where anthelminthic drugs have been repeatedly administered over the past decade. METHODOLOGY/PRINCIPAL FINDINGS: Three serial stool samples from each of 342 schoolchildren were examined using the Kato-Katz (K-K, Koga agar plate (KAP, and Baermann (BM techniques. These methods were used individually or in combination for the diagnosis of Ascaris lumbricoides (K-K, Trichuris trichiura (K-K, hookworm (K-K and KAP, and Strongyloides stercoralis (KAP and BM. The examination of multiple stool samples instead of a single one resulted in an increase of the observed prevalence; e.g., an increase of 161% for hookworm using the K-K method. The diagnostic sensitivity of single stool sampling ranged between 20.7% for BM to detect S. stercoralis and 84.2% for K-K to diagnose A. lumbricoides. Highest sensitivities were observed when different diagnostic approaches were combined. The observed prevalences for T. trichiura, hookworm, A. lumbricoides, and S. stercoralis were 47.9%, 22.5%, 16.5%, and 10.8% after examining 3 stool samples. These values are close to the 'true' prevalences predicted by a mathematical model. CONCLUSION/SIGNIFICANCE: Rigorous epidemiologic surveillance of soil-transmitted helminthiasis in the era of preventive chemotherapy is facilitated by multiple stool sampling bolstered by different diagnostic techniques.

  12. 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.

  13. A diagnostic system for electrical faults in a high current discharge plasma setup

    Science.gov (United States)

    Nigam, S.; Aneesh, K.; Navathe, C. P.; Gupta, P. D.

    2011-02-01

    A diagnostic system to detect electrical faults inside a coaxial high current discharge device is presented here. This technique utilizes two biconical antennas picking up electromagnetic radiation from the discharge device, a voltage divider sensing input voltage, and a Rogowski coil measuring the main discharge current. A computer program then analyses frequency components in these signals and provides information as to whether the discharge event was normal or any breakdown fault occurred inside the coaxial device. The diagnostic system is developed for a 450 kV and 50 kA capillary discharge plasma setup. For the setup various possible faults are analyzed by electrical simulation, followed by experimental results. In the case of normal discharge through the capillary load the dominant frequency is ˜4 MHz. Under faulty conditions, the peak in magnitude versus frequency plot of the antenna signal changes according to the fault position which involves different paths causing variation in the equivalent circuit elements.

  14. Experiments with Dipole Antennas

    Science.gov (United States)

    Kraftmakher, Yaakov

    2009-01-01

    Employment of a data-acquisition system for data collection and calculations makes experiments with antennas more convenient and less time consuming. The determined directional patterns of the dipole antennas of different lengths are in reasonable agreement with theory. The enhancement of the signal by using a reflector is demonstrated, and a…

  15. 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...... required by the wide-band antenna....

  16. Milestones in Broadcasting: Antennas.

    Science.gov (United States)

    Media in Education and Development, 1985

    1985-01-01

    Briefly describes the development of antennas in the prebroadcast era (elevated antenna, selectivity to prevent interference between stations, birth of diplex, directional properties, support structures), as well as technological developments used in long-, medium-, and short-wave broadcasting, VHF/FM and television broadcasting, and satellite…

  17. Reconfigurable Array Antenna Using Microelectromechanical Systems (MEMS) Actuators

    Science.gov (United States)

    Simons, Rainee N.; Chun, Donghoon; Katehi, Linda P. B.

    2001-01-01

    The paper demonstrates a patch antenna integrated with a novel microelectromechanical systems (MEMS) actuator for reconfiguring the operating frequency. Experimental results demonstrate that the center frequency can be reconfigured by as much as 1.6 percent of the nominal operating frequency at K-Band In addition, a novel on-wafer antenna pattern measurement technique is demonstrated.

  18. Low-SAR metamaterial-inspired printed monopole antenna

    Science.gov (United States)

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

    2017-01-01

    In this paper, a low-SAR metamaterial-embedded planar monopole antenna is introduced for a wireless communication system. A printed monopole antenna is designed for modern mobile, which operates in GSM, UMTS, LTE, WLAN, and Bluetooth frequency bands. A metamaterial structure is designed to use in the mobile handset with a multi-band printed monopole antenna. The finite integration technique of the CST microwave studio is used in this study. The measurement of antenna performances is taken in an anechoic chamber, and the SAR values are measured using COMOSAR system. The results indicate that metamaterial structure leads to reduce SAR without affecting antenna performance significantly. According to the measured results, the metamaterial attachment leads to reduce 87.7% peak SAR, 68.2% 1-g SAR, and 46.78% 10-g SAR compared to antenna without metamaterial.

  19. A new planar feed for slot spiral antennas

    Science.gov (United States)

    Nurnberger, M. W.; Volakis, J. L.

    1995-01-01

    This report presents a new planar, wideband feed network for a slot spiral antenna, and the subsequent design and performance of a VHF antenna utilizing this feed design. Both input impedance and radiation pattern measurements are presented to demonstrate the performance and usefulness of this feed. Almost all previous designs have utilized wire spirals, requiring bulky, non-planar feeds with separate baluns, and large absorbing cavities. The presented slot spiral antenna feed integrates the balun into the structure of the slot spiral antenna, making the antenna and feed planar. This greatly simplifies the design and construction of the antenna, in addition to providing repeatable accuracy. It also allows the use of a very shallow reflecting cavity for conformal applications. Finally, this feeding approach now makes many of the known miniaturization techniques viable options.

  20. Implementation and characterization of meta-resonator antennas

    Science.gov (United States)

    Kim, In Kwang; Varadan, Vasundara V.

    2015-04-01

    Metamaterials are artificially engineered microstructures that have strong resonance behavior although their electrical size is very small. Meta-resonator (metamaterial resonator) antennas use the resonance of the metamaterials to reduce the size of radiators and design multiband antennas. A split-ring resonator (SRR) is a well-studied metamaterial structure which obtains negative permittivity and/or permeability in a narrow frequency region. In this paper, metamaterial structures and meta-resonator antennas are designed and simulated using a full wave simulator. 2D metaresonator antennas are fabricated by photolithography and 3D meta-resonator antennas are fabricated by LTCC (Low- Temperature Co-fired Ceramic) technique. A free space measurement system is used to characterize metamaterial samples. Several 2D/3D meta-resonator antennas with SRRs are described.

  1. Automated parametrical antenna modelling for ambient assisted living applications

    Science.gov (United States)

    Kazemzadeh, R.; John, W.; Mathis, W.

    2012-09-01

    In this paper a parametric modeling technique for a fast polynomial extraction of the physically relevant parameters of inductively coupled RFID/NFC (radio frequency identification/near field communication) antennas is presented. The polynomial model equations are obtained by means of a three-step procedure: first, full Partial Element Equivalent Circuit (PEEC) antenna models are determined by means of a number of parametric simulations within the input parameter range of a certain antenna class. Based on these models, the RLC antenna parameters are extracted in a subsequent model reduction step. Employing these parameters, polynomial equations describing the antenna parameter with respect to (w.r.t.) the overall antenna input parameter range are extracted by means of polynomial interpolation and approximation of the change of the polynomials' coefficients. The described approach is compared to the results of a reference PEEC solver with regard to accuracy and computation effort.

  2. ANTENNA OF RADIO CONTROL

    Directory of Open Access Journals (Sweden)

    Ludwig Ilnytskyi

    2015-12-01

    Full Text Available The article is devoted to current issues in the field of radio monitoring. In this article was considered the antenna of radio control, which represents a grid from three vibrators. Threelement antenna array provides simultaneous control of two radio electronic devices that radiates at frequencies that are close to each other. Antenna system using simple technical means provides noise suppression, even if noise will have the same frequency as useful signal. This makes it possible to use the antenna system in conditions of multibeam wave propagation under the adjustment on the most intense by the power beam. Antenna system makes it possible to measure the electromagnetic field intensity, congestion of the frequency spectrum, direction of noise electromagnetic waves incidence, noise electric field intensity.

  3. Handbook of antenna technologies

    CERN Document Server

    Liu, Duixian; Nakano, Hisamatsu; Qing, Xianming; Zwick, Thomas

    2016-01-01

    The Handbook of Antenna Technologies aims to present the rapid development of antenna technologies, particularly in the past two decades, and also showcasing the newly developed technologies and the latest applications. The handbook will provide readers with the comprehensive updated reference information covering theory, modeling and optimization methods, design and measurement, new electromagnetic materials, and applications of antennas. The handbook will widely cover not only all key antenna design issues but also fundamentals, issues related to antennas (transmission, propagation, feeding structure, materials, fabrication, measurement, system, and unique design challenges in specific applications). This handbook will benefit the readers as a full and quick technical reference with a high-level historic review of technology, detailed technical descriptions and the latest practical applications.

  4. Genetic Algorithm Optimization and Performance Comparative Analysis of Rectangular, Triangular and Circular Patch Antennas for X Band Applications

    OpenAIRE

    Hayat Errifi; Abdennaceur Baghdad; Abdelmajid Badri; Aicha Sahel

    2015-01-01

    The growth of portable wireless communication devices has pushed designers to design miniature size antennas. The most prized among miniature antenna choices is the micro-strip patch antenna. These antennas have significant advantages such as low profile, light weight, relatively low manufacturing cost, and polarization diversity. In this paper Genetic Algorithm optimization technique has been utilized for dimensions optimization of three types of patch antennas in addition to the comparat...

  5. A linearly and circularly polarized active integrated antenna

    Science.gov (United States)

    Khoshniat, Ali

    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 it can be conveniently mass-produced and designed to have circular polarization, which is preferred in many applications such as satellite communications. The antenna simulations were performed using Ansoft High Frequency System Simulator (HFSS) and all amplifier design steps were simulated by Advanced Design System (ADS). The final prototypes of the linearly polarized active integrated antenna and the circularly polarized active integrated antenna were fabricated using a circuit board milling machine. The antenna radiation pattern was measured inside Utah State University's anechoic chamber and the results were satisfactory. Power measurements for the amplifiers' performance were carried out inside the chamber and calculated by using the Friis transmission equation. It is seen that a significant improvement in the efficiency is achieved compared to the reference antenna without harmonic suppression. Based on the success in the single element active antenna design, the thesis also presents a feasibility of applying the active integrated antenna in array configuration, in particular, in scanning array design to yield a low-profile, low-cost alternative to the parabolic antenna transmitter of satellite communication systems.

  6. 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;

    field side and one on the high field side, it is possible to resolve the distribution function of fast ions both for perpendicular and parallel velocities with good spatial and temporal resolution. The present work concerned a continuation of this work, and the following tasks were performed. 1...... experiment was set up in order to test and support the theoretical and numerical results. From the design studies various R&D issues critical to the viability of the CTS diagnostic on ITER were identified; the most urgent ones are addressed in the presented R&D tasks....

  7. JAK2 V617F in myeloid disorders: molecular diagnostic techniques and their clinical utility: a paper from the 2005 William Beaumont Hospital Symposium on Molecular Pathology.

    Science.gov (United States)

    Steensma, David P

    2006-09-01

    In early 2005, several groups of investigators studying myeloid malignancies described a novel somatic point mutation (V617F) in the conserved autoinhibitory pseudokinase domain of the Janus kinase 2 (JAK2) protein, which plays an important role in normal hematopoietic growth factor signaling. The V617F mutation is present in blood and marrow from a large proportion of patients with classic BCR/ABL-negative chronic myeloproliferative disorders and of a few patients with other clonal hematological diseases such as myelodysplastic syndrome, atypical myeloproliferative disorders, and acute myeloid leukemia. The JAK2 V617F mutation causes constitutive activation of the kinase, with deregulated intracellular signaling that mimics continuous hematopoietic growth factor stimulation. Within 7 months of the first electronic publication describing this new mutation, clinical molecular diagnostic laboratories in the United States and Europe began offering JAK2 mutation testing on a fee-for-service basis. Here, I review the various techniques used by research groups and clinical laboratories to detect the genetic mutation underlying JAK2 V617F, including fluorescent dye chemistry sequencing, allele-specific polymerase chain reaction (PCR), real-time PCR, DNA-melting curve analysis, pyrosequencing, and others. I also discuss diagnostic sensitivity, performance, and other practical concerns relevant to the clinical laboratorian in addition to the potential diagnostic utility of JAK2 mutation tests.

  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. Electromagnetics and antenna optimization using Taguchi's method

    CERN Document Server

    Weng, Wei-Chung

    2007-01-01

    This book presents a new global optimization technique using Taguchi's method and its applications in electromagnetics and antenna engineering. Compared with traditional optimization techniques, Taguchi's optimization method is easy to implement and very efficient in reaching optimum solutions.Taguchi's optimization method is developed based on the orthogonal array (OA) concept, which offers a systematic and efficient way to select design parameters. The book illustrates the basic implementation procedure of Taguchi's optimization method and discusses various advanced techniques for performanc

  10. 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.

  11. Synthesis of multiple shaped beam antenna patterns

    Science.gov (United States)

    Stutzman, W. L.; Coffey, E. L.

    1973-01-01

    Results are presented of research into the problem of finding an excitation of a given antenna such that the desired radiation pattern is approximated to within acceptable limits. This is to be done in such a fashion that boundary conditions involving hardware limitations may be inserted into the problem. The intended application is synthesis of multiple shaped beam antennas. Since this is perhaps the most difficult synthesis problem an antenna engineer is likely to encounter, the approach taken was to include as a by-product capability for synthesizing simpler patterns. The synthesis technique has been almost totally computerized. The class of antennas which may be synthesized with the computer program are those which may be represented as planar (continuous or discrete) current distributions. The technique is not limited in this sense and could indeed by extended to include, for example, the synthesis of conformal arrays or current distributions on the surface of reflectors. The antenna types which the program is set up to synthesize are: line source, rectangular aperture, circular aperture, linear array, rectangular array, and arbitrary planar array.

  12. Photocurrent mapping of near-field optical antenna resonances.

    Science.gov (United States)

    Barnard, Edward S; Pala, Ragip A; Brongersma, Mark L

    2011-08-21

    An increasing number of photonics applications make use of nanoscale optical antennas that exhibit a strong, resonant interaction with photons of a specific frequency. The resonant properties of such antennas are conventionally characterized by far-field light-scattering techniques. However, many applications require quantitative knowledge of the near-field behaviour, and existing local field measurement techniques provide only relative, rather than absolute, data. Here, we demonstrate a photodetector platform that uses a silicon-on-insulator substrate to spectrally and spatially map the absolute values of enhanced fields near any type of optical antenna by transducing local electric fields into photocurrent. We are able to quantify the resonant optical and materials properties of nanoscale (∼50 nm) and wavelength-scale (∼1 µm) metallic antennas as well as high-refractive-index semiconductor antennas. The data agree well with light-scattering measurements, full-field simulations and intuitive resonator models.

  13. 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.

  14. 口蹄疫诊断技术的研究进展%Research Progress on Diagnostic Techniques of Foot-and-mouth Disease

    Institute of Scientific and Technical Information of China (English)

    特尼格尔; 黄天鹏

    2016-01-01

    口蹄疫的准确诊断是有效控制疫情蔓延的重要环节。随着生物学技术的迅速发展,口蹄疫的诊断已经不再局限于传统方法。目前,常用的口蹄疫诊断方法包括血清学检测、分子生物学诊断和病原学诊断,其中以血清学检测的应用最为广泛。阐述了3种诊断方法的原理及优缺点,并展望了口蹄疫诊断技术未来的发展方向。%The accurate diagnosis of foot-and-mouth disease is essential to control the spread of the disease. With the rapid development of biotechnology, the diagnosis of foot-and-mouth disease is no longer restricted to traditional methods. At present, the commonly used methods are including serological detection which has the widest application range, molecular biological diagnosis and etiological diagnosis. In this paper, a review is given on the principle as well as advantages and disadvantages of the 3 above-mentioned diagnostic techniques, and the future development of foot-and-mouth disease diagnostic techniques is prospected.

  15. 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.

  16. Integrated Millimeter-Wave Antennas for On-Chip Communication

    Directory of Open Access Journals (Sweden)

    S. Zainud-Deen

    2016-03-01

    Full Text Available This paper introduces the design and analysis of circularly polarized (CP and dual-polarized on-chip microstrip antennas for wireless communication at 60 GHz. The CP on-chip antenna consists of a circular aluminum patch with two overlapped circular slots fed by the transmission line. The radiation characteristics of the CP have been analyzed using the finite integration technique and finite element method based electromagnetic solvers. The CP antenna introduces left-hand circular polarization and employs as on-chip transmitter. A design of dual-polarized on-chip microstrip antenna at 60 GHz is investigated and is employed as on-chip receiver. The dual ports of the dual polarized antenna are designed with high isolation between them in order to be used as a two on-chip receivers. The radiation characteristics of the dual-port antenna have been calculated. The effect of the separation distance between the CP-antenna and the dual-polarized antenna on the same chip has been investigated. The performance parameters like the reflection coefficient, transmission coefficient, and the transmission gain of the two antennas at different separation distances have been introduced.

  17. 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.

  18. Bandwidth Improvement of UWB Microstrip Antenna Using Finite Ground Plane

    Directory of Open Access Journals (Sweden)

    Priyanka Mishra

    2015-06-01

    Full Text Available Microstrip antennas play a vital role in communication system. It is required in high performance wireless applications. But due to its resonant nature microstrip antennas have some considerable drawbacks like narrowband performance. Extensive study has been carried out on microstrip patch antennas in the recent past, but it still have large scope for improvement in the near future. To overcome narrow bandwidth problem, number of methods and techniques have been suggested and investigated, keeping in mind that the basic advantages of microstrip antenna should not be altered such as low profile, light weight, low cost and simple printed circuit structure. The area of investigation includes modification in geometrical shape of the antenna, use of resonators, use of dipole, and many other parameters. This paper presents a comparison between conventional microstrip antenna and microstip antenna with finite ground plane at ultra wideband. HFSS simulation tool is used here for antenna simulation. For feeding purpose microstrip feed line is used (50Ω. Optimized result provides impedance bandwidth of 7.2GHz with VSWR<2, operating frequency range is from 6.5GHz to 13.7GHz. Proposed antenna is useful for many ultra wideband applications.

  19. Small inductor Loaded mobile phone Antenna

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2004-01-01

    In this paper a size reduction technique of the Planar Inverted F Antenna (PIFA) is presented. Using an 18 nH lumped inductor in addition to a small 0.3 cm3 PIFA located on a 5 mm thick dielectric foam above a 40 x 100 mm2 ground plane it is possible to reduce the resonant frequency by 33 % for a...

  20. Dielectric Covered Planar Antennas

    Science.gov (United States)

    Llombart Juan, Nuria (Inventor); Lee, Choonsup (Inventor); Chattopadhyay, Goutam (Inventor); Gill, John J. (Inventor); Skalare, Anders J. (Inventor); Siegel, Peter H. (Inventor)

    2014-01-01

    An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

  1. 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.

  2. 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.

  3. Electrically driven optical antennas

    Science.gov (United States)

    Kern, Johannes; Kullock, René; Prangsma, Jord; Emmerling, Monika; Kamp, Martin; Hecht, Bert

    2015-09-01

    Unlike radiowave antennas, so far optical nanoantennas cannot be fed by electrical generators. Instead, they are driven by light or indirectly via excited discrete states in active materials in their vicinity. Here we demonstrate the direct electrical driving of an in-plane optical antenna by the broadband quantum-shot noise of electrons tunnelling across its feed gap. The spectrum of the emitted photons is determined by the antenna geometry and can be tuned via the applied voltage. Moreover, the direction and polarization of the light emission are controlled by the antenna resonance, which also improves the external quantum efficiency by up to two orders of magnitude. The one-material planar design offers facile integration of electrical and optical circuits and thus represents a new paradigm for interfacing electrons and photons at the nanometre scale, for example for on-chip wireless communication and highly configurable electrically driven subwavelength photon sources.

  4. Array Antenna Limitations

    CERN Document Server

    Jonsson, B L G; Hussain, N

    2013-01-01

    This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and scan-range. The result is based on a sum-rule result of Rozanov-type for linear polarization. For single-band antennas it extends an existing limit for a given fixed scan-angle to include the whole scan-range of the array, as well as the unit-cell structure in the bound. The letter ends with an investigation of the array figure of merit for some wideband and/or wide-scan antennas with linear polarization. We find arrays with a figure of merit >0.6 that empirically defines high-performance antennas with respect to this measure.

  5. Diagnostic accuracy: theoretical models for preimplantation genetic testing of a single nucleus using the fluorescence in situ hybridization technique

    NARCIS (Netherlands)

    P.N. Scriven; P.M.M. Bossuyt

    2010-01-01

    The aim of this study was to develop and use theoretical models to investigate the accuracy of the fluorescence in situ hybridization (FISH) technique in testing a single nucleus from a preimplantation embryo without the complicating effect of mosaicism. Mathematical models were constructed for thre

  6. 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

  7. Comparison of three diagnostic techniques for detecting occlusal dental caries in primary molars: An in vivo study

    Directory of Open Access Journals (Sweden)

    Farhin Katge

    2016-01-01

    Conclusion: This study showed low sensitivity but substantial specificity with visual inspection. Bitewing radiography performed poorly overall when compared with the other two systems. The CarieScan PRO technique gave the highest overall combination of sensitivity and specificity for detection of occlusal caries.

  8. Diagnostic significance of gas distension technique of the stomach with gas-forming agent on CT scan of stomach cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rho, Tae Jin; Song, Chang June; Choi, Joong Chan; Park, Cheong Hee; Cho, June Sik; Rhee, Byung Chull [Chungnam National University College of Medicine, Dajeon (Korea, Republic of)

    1988-10-15

    CT is a valuable method for preoperative staging of patients with stomach cancers. However, in patients with poor distension of the stomach and scanty fat between the stomach and adjacent organs, CT findings may indicate a false impression of gastric wall thickening and cannot provide the precise extent of stomach cancer. We studied the usefulness of gastric distension by gas-forming agent in 28 cases of pathologically confirmed gastric cancers on CT. Comparative analysis between CT findings and surgical pathologic findings was done in 22 cases who underwent surgery. The results were as follows; 1. Conventional CT failed to define the wall thickening or masses of the stomach, in 14 cases of 23 advanced gastric cancers, while CT with gas distension technique allowed good visualization in all advanced gastric cancers. 2. In 2 cases of 5 early gastric cancers, CT with gas distension technique could detect focal thickening of the gastric wall, even less than 1cm thickness. 3. Among 13 cases with indistinguishable border between stomach and liver on conventional CT, 7 cases were diagnosed as negative invasion on CT with gas distension technique and 5 cases of these were confirmed by surgery. 4. Among 11 cases with indistinguishable border between stomach and pancreas on conventional CT, 3 cases were diagnosed as negative invasion on CT with gas distension technique, all of which were confirmed by surgery. 5. There was no significant difference between conventional CT and CT with gas distension technique of the stomach to diagnose invasion into transverse colon, transverse colon, transverse mesocolon, lymph node metastasis, and various distant metastasis.

  9. Optical antenna gain. II - Receiving antennas

    Science.gov (United States)

    Degnan, J. J.; Klein, B. J.

    1974-01-01

    Expressions are developed for the gain of a centrally obscured, circular optical antenna used as the collecting and focusing optics in a laser receiver, involving losses due to (1) incoming light blockage by central obscuration, (2) energy spillover at the detector, and (3) the effect of local oscillator distribution in the case of heterodyne or homodyne detection. Numerical results are presented for direct detection and for three types of local oscillator distribution (uniform, Gaussian, and matched).

  10. 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.

  11. IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION

    Science.gov (United States)

    ABRANTES, Tuanne Rotti; MADEIRA, Maria de Fátima; da SILVA, Denise Amaro; PERIÉ, Carolina dos Santos F. S.; V. MENDES, Artur Augusto; MENEZES, Rodrigo Caldas; SILVA, Valmir Laurentino; FIGUEIREDO, Fabiano Borges

    2016-01-01

    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. PMID:26910449

  12. Novel antenna concepts via coordinate transformation

    Directory of Open Access Journals (Sweden)

    P.-H. Tichit

    2013-02-01

    Full Text Available Coordinate transformation is an emerging field which offers a powerful and unprecedented ability to manipulate and control electromagnetic waves. Using this tool, we demonstrate the design of novel antenna concepts by tailoring their radiation properties. The wave manipulation is enabled through the use of engineered dispersive composite metamaterials that realize the space coordinate transformation. Three types of antennas are considered for design: a directive, a beam steerable and a quasi-isotropic one. Numerical simulations together with experimental measurements are performed in order to validate the coordinate transformation concept. Near-field cartography and far-field pattern measurements performed on a fabricated prototype agree qualitatively with Finite Element Method (FEM simulations. It is shown that a particular radiation pattern can be tailored at ease into a desired one by modifying the electromagnetic properties of the space around radiator. This idea opens the way to novel antenna design techniques for various application domains such as the aeronautical and transport fields.

  13. Screen printed UHF antennas on flexible substrates

    Science.gov (United States)

    Janeczek, Kamil; Młożniak, Anna; Kozioł, Grażyna; Araźna, Aneta; Jakubowska, Małgorzata; Bajurko, Paweł

    2010-09-01

    Printed electronics belongs to the most important developing electronics technologies. It provides new possibilities to produce low cost and large area devices. In its range several applications can be distinguished like printed batteries, OLED, biosensors, photovoltaic cells or RFID tags. In the presented investigation, antennas working in UHF frequency range were elaborated. It can be applied in the future for flexible RFID tags. To produce these antennas polymer paste with silver flakes was used. It was deposited on two flexible substrates (foil and photo paper) with screen printing techniques. After printing process surface profile, electrical and microwave parameters of performed antennas were measured using digital multimeter and network analyzer, relatively. Furthermore, a thickness of printed layers was measured.

  14. On-the-Fly Mapping for Calibrating Directional Antennas

    Science.gov (United States)

    Rochblatt, David; Richter, Paul; Withington, Philip

    2004-01-01

    An improved method of calibrating a large directional radio antenna of the type used in deep-space communication and radio astronomy has been developed. This method involves a raster-scanning-and-measurement technique denoted on-the-fly (OTF) mapping, applied in consideration of the results of a systematic analysis of the entire measurement procedure. Phenomena to which particular attention was paid in the analysis include (1) the noise characteristics of a total-power radiometer (TPR) that is used in the measurements and (2) tropospherically induced radiometer fluctuations. The method also involves the use of recently developed techniques for acquisition and reduction of data. In comparison with prior methods used to calibrate such antennas, this method yields an order-of-magnitude improvement in the precision of determinations of antenna aperture efficiency, and improvement by a factor of five or more in the precision of determination of pointing error and beam width. Prerequisite to a meaningful description of the present method is some background information concerning three aspects of the problem of calibrating an antenna of the type in question: In OTF mapping measurements in which a TPR is used, the desired data are the peak temperature corresponding to a radio source, the pointing offset when the antenna is commanded to point toward the source, and the shape of the main lobe of the antenna beam, all as functions of the antenna beam elevation and azimuth angles. These data enable one to calculate the (1) antenna aperture efficiency by comparing the measured peak temperature with that expected for a 100-percent-efficient antenna, (2) the mechanical pointing error resulting from small misalignments of various parts of the antenna structure, and (3) misalignments of the antenna subreflector and other mirrors. For practical reasons having to do with obtaining adequate angular resolution and all-sky coverage, it is necessary to perform azimuth and elevation scans

  15. Assessment of African Swine Fever Diagnostic Techniques as a Response to the Epidemic Outbreaks in Eastern European Union Countries: How To Improve Surveillance and Control Programs.

    Science.gov (United States)

    Gallardo, C; Nieto, R; Soler, A; Pelayo, V; Fernández-Pinero, J; Markowska-Daniel, I; Pridotkas, G; Nurmoja, I; Granta, R; Simón, A; Pérez, C; Martín, E; Fernández-Pacheco, P; Arias, M

    2015-08-01

    This study represents a complete comparative analysis of the most widely used African swine fever (ASF) diagnostic techniques in the European Union (EU) using field and experimental samples from animals infected with genotype II ASF virus (ASFV) isolates circulating in Europe. To detect ASFV, three different PCRs were evaluated in parallel using 785 field and experimental samples. The results showed almost perfect agreement between the Universal ProbeLibrary (UPL-PCR) and the real-time (κ = 0.94 [95% confidence interval {CI}, 0.91 to 0.97]) and conventional (κ = 0.88 [95% CI, 0.83 to 0.92]) World Organisation for Animal Health (OIE)-prescribed PCRs. The UPL-PCR had greater diagnostic sensitivity for detecting survivors and allows earlier detection of the disease. Compared to the commercial antigen enzyme-linked immunosorbent assay (ELISA), good-to-moderate agreement (κ = 0.67 [95% CI, 0.58 to 0.76]) was obtained, with a sensitivity of 77.2% in the commercial test. For ASF antibody detection, five serological methods were tested, including three commercial ELISAs, the OIE-ELISA, and the confirmatory immunoperoxidase test (IPT). Greater sensitivity was obtained with the IPT than with the ELISAs, since the IPT was able to detect ASF antibodies at an earlier point in the serological response, when few antibodies are present. The analysis of the exudate tissues from dead wild boars showed that IPT might be a useful serological tool for determining whether or not animals had been exposed to virus infection, regardless of whether antibodies were present. In conclusion, the UPL-PCR in combination with the IPT was the most trustworthy method for detecting ASF during the epidemic outbreaks affecting EU countries in 2014. The use of the most appropriate diagnostic tools is critical when implementing effective control programs.

  16. Partial Reflection Spaced Antenna Wind Measurements

    Science.gov (United States)

    Fraser, G. J.

    1984-01-01

    The nature of partially reflecting (PR) irregularities is briefly reviewed and the techniques used in the PR spaced antenna method are discussed. The radars addressed use frequencies in the 2 to 6 MHz range operate in a pulse mode at vertical incidence. Radar system parameters including receiver dynamic range, coherent and incoherent detection, and post detection filtering are examined. Finally, data system parameters and real time analysis techniques are discussed.

  17. Performance assessment of the antenna setup for the ITER plasma position reflectometry in-vessel systems

    Science.gov (United States)

    Varela, P.; Belo, J. H.; Quental, P. B.

    2016-11-01

    The design of the in-vessel antennas for the ITER plasma position reflectometry diagnostic is very challenging due to the need to cope both with the space restrictions inside the vacuum vessel and with the high mechanical and thermal loads during ITER operation. Here, we present the work carried out to assess and optimise the design of the antenna. We show that the blanket modules surrounding the antenna strongly modify its characteristics and need to be considered from the early phases of the design. We also show that it is possible to optimise the antenna performance, within the design restrictions.

  18. Performance assessment of the antenna setup for the ITER plasma position reflectometry in-vessel systems.

    Science.gov (United States)

    Varela, P; Belo, J H; Quental, P B

    2016-11-01

    The design of the in-vessel antennas for the ITER plasma position reflectometry diagnostic is very challenging due to the need to cope both with the space restrictions inside the vacuum vessel and with the high mechanical and thermal loads during ITER operation. Here, we present the work carried out to assess and optimise the design of the antenna. We show that the blanket modules surrounding the antenna strongly modify its characteristics and need to be considered from the early phases of the design. We also show that it is possible to optimise the antenna performance, within the design restrictions.

  19. 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.

  20. 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

  1. A Short Review of Passive R. F. Electric Antennas as In Situ Detectors of Space Plasmas

    Science.gov (United States)

    Moncuquet, M.; Meyer-Vernet, N.; Bougeret, J.-L.; Hoang, S.; Issautier, K.; Lecacheux, A.; Maksimovic, M.; Pantellini, F.; Zarka, P.; Zouganelis, I.

    2009-06-01

    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

  2. Re-exploring the high-throughput potential of microextraction techniques, SPME and MEPS, as powerful strategies for medical diagnostic purposes. Innovative approaches, recent applications and future trends.

    Science.gov (United States)

    Pereira, Jorge; Silva, Catarina Luís; Perestrelo, Rosa; Gonçalves, João; Alves, Vera; Câmara, José S

    2014-03-01

    The human population continues to grow exponentially in the fast developing and most populated countries, whereas in Western Europe it is getting older and older each year. This inevitably raises the demand for better and more efficient medical services without increasing the economic burden in the same proportion. To meet these requirements, improvement of medical diagnosis is certainly a key aspect to consider. Therefore, we need powerful analytical methodologies able to go deeper and further in the characterization of human metabolism and identification of disease biomarkers and endogenous molecules in body fluids and tissues. The ultimate goal is to have a reliable and early medical diagnosis, mitigating the disease complications as much as possible. Microextraction techniques (METs) represent a key step in these analytical methodologies by providing samples in the suitable volumes and purification levels necessary for the characterization of the target analytes. In this aspect, solid-phase microextraction (SPME) and, more recently, microextraction by packed sorbent (MEPS), are powerful sample preparation techniques, characterized by their reduced time of analysis, low solvent consumption, and broad application. Moreover, as miniaturized techniques, they can be easily automatized to have a high-throughput performance in the clinical environment. In this review, we explore some of the most interesting MEPS and SPME applications, focusing on recent trends and applications to medical diagnostic, particularly the in vivo and near real time applications.

  3. 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.

  4. 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.

  5. Circularly split-ring-resonator-based frequency-reconfigurable antenna

    Science.gov (United States)

    Rahman, M. A.; Faruque, M. R. I.; Islam, M. T.

    2017-01-01

    In this paper, an antenna with frequency configurability in light of a circularly split-ring resonator (CSRR) is introduced. The proposed reconfigurable monopole antenna consists of a microstrip-fed hook-shaped structure and a CSRR having single reconfigurable split only. A new band of radiation unlike the band radiated from monopole only is observed due to magnetic coupling between the CSRR and the monopole antenna. The resonance frequency of the CSRR can be arbitrarily chosen by varying the dimension and relative position of its gap with the monopole, which leads the antenna to become reconfigurable one. By using a single switch with perfect electric conductor at the gap of CSRR cell, the effect of CSRR can be deactivated and, hence, it is possible to suppress the corresponding resonance, resulting in a frequency-reconfigurable antenna. Commercially available Computer Simulation Technology microwave studio based on finite integration technique was adopted throughout the study.

  6. Artificial impedance ground planes for low profile antenna applications

    Science.gov (United States)

    McMichael, Ian T.

    Recent interest in artificial impedance surfaces for low-profile antennas has led to extensive research with the goal of optimizing the ground plane's characteristics for a given antenna configuration and broadening the operational bandwidth, or alternatively creating a multi-band functionality. A method of determining the optimal reflection phase for a low-profile dipole antenna over an electromagnetic band gap (EBG) ground plane has been developed based on image theory and is presented with experimental and numerical validation. A new artificial impedance surface has also been developed, which is composed of an annular slot ring on a thin grounded dielectric. The main difference between the proposed ground plane and a conventional EBG is that the high impedance condition exists only in the vicinity of the slot and is therefore best suited for antennas with a current distribution that has a similar shape as the annular slot ring. It is shown that a loop antenna positioned closely over an annular slot loaded ground plane exhibits approximately the same gain as a loop antenna over a conventional EBG ground plane. The advantage of the new structure is its lack of periodicity, which significantly eases manufacturing. Additionally, it is shown that multiple concentric slot rings can be designed into the ground plane, which excites multiple resonances in low-profile wideband antennas. The result is a multi-band high impedance ground plane constructed using a simple arrangement of annular slots. Finally, a manufacturing technique is presented for the application of arbitrarily configured EBG antennas to handheld dual-sensor landmine detection systems. It is shown that creating an EBG antenna using very thin layers of metal will enable it to be used for ground penetrating radar (GPR) when it is co-located with a low frequency metal detector without compromising the operation of the metal detector. The potential benefit of such an antenna would be a lower profile sensor

  7. 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.

  8. Electromagnetic characterization of conformal antennas

    Science.gov (United States)

    Volakis, John L.; Kempel, Leo C.; Alexanian, Angelos; Jin, J. M.; Yu, C. L.; Woo, Alex C.

    1992-01-01

    The ultimate objective of this project is to develop a new technique which permits an accurate simulation of microstrip patch antennas or arrays with various feed, superstrate and/or substrate configurations residing in a recessed cavity whose aperture is planar, cylindrical or otherwise conformed to the substructure. The technique combines the finite element and boundary integral methods to formulate a system suitable for solution via the conjugate gradient method in conjunction with the fast Fourier transform. The final code is intended to compute both scattering and radiation patterns of the structure with an affordable memory demand. With upgraded capabilities, the four included papers examined the radar cross section (RCS), input impedance, gain, and resonant frequency of several rectangular configurations using different loading and substrate/superstrate configurations.

  9. Electrochemically Programmable Plasmonic Antennas.

    Science.gov (United States)

    Dong, Shi; Zhang, Kai; Yu, Zhiping; Fan, Jonathan A

    2016-07-26

    Plasmonic antennas are building blocks in advanced nano-optical systems due to their ability to tailor optical response based on their geometry. We propose an electrochemical approach to program the optical properties of dipole antennas in a scalable, fast, and energy-efficient manner. These antennas comprise two arms, one serving as an anode and the other a cathode, separated by a solid electrolyte. As a voltage is applied between the antenna arms, a conductive filament either grows or dissolves within the electrolyte, modifying the antenna load. We probe the dynamics of stochastic filament formation and their effects on plasmonic mode programming using a combination of three-dimensional optical and electronic simulations. In particular, we identify device operation regimes in which the charge-transfer plasmon mode can be programmed to be "on" or "off." We also identify, unexpectedly, a strong correlation between DC filament resistance and charge-transfer plasmon mode frequency that is insensitive to the detailed filament morphology. We envision that the scalability of our electrochemical platform can generalize to large-area reconfigurable metamaterials and metasurfaces for on-chip and free-space applications.

  10. Cup Cylindrical Waveguide Antenna

    Science.gov (United States)

    Acosta, Roberto J.; Darby, William G.; Kory, Carol L.; Lambert, Kevin M.; Breen, Daniel P.

    2008-01-01

    The cup cylindrical waveguide antenna (CCWA) is a short backfire microwave antenna capable of simultaneously supporting the transmission or reception of two distinct signals having opposite circular polarizations. Short backfire antennas are widely used in mobile/satellite communications, tracking, telemetry, and wireless local area networks because of their compactness and excellent radiation characteristics. A typical prior short backfire antenna contains a half-wavelength dipole excitation element for linear polarization or crossed half-wavelength dipole elements for circular polarization. In order to achieve simultaneous dual circular polarization, it would be necessary to integrate, into the antenna feed structure, a network of hybrid components, which would introduce significant losses. The CCWA embodies an alternate approach that entails relatively low losses and affords the additional advantage of compactness. The CCWA includes a circular cylindrical cup, a circular disk subreflector, and a circular waveguide that serves as the excitation element. The components that make it possible to obtain simultaneous dual circular polarization are integrated into the circular waveguide. These components are a sixpost polarizer and an orthomode transducer (OMT) with two orthogonal coaxial ports. The overall length of the OMT and polarizer (for the nominal middle design frequency of 2.25 GHz) is about 11 in. (approximately equal to 28 cm), whereas the length of a commercially available OMT and polarizer for the same frequency is about 32 in. (approximately equal to 81 cm).

  11. Utilizing Symmetry of Planar Ultra-Wideband Antennas for Size Reduction and Enhanced Performance

    CERN Document Server

    Mobashsher, Ahmed Toaha

    2015-01-01

    With the increasingly new ultra wide-band applications, antenna researchers face huge challenges in designing novel operational geometries. Mono-pole and quasi-mono-pole antennas are seen to be the most compact and easily incorporate able solution for portable devices taking the advantages of printed circuit board (PCB) techniques. Most antennas of such type have symmetrical structures. It is possible to attain wider operating bandwidths by meeting symmetry conditions while chopping the antenna into halves for a compact structure. However, there is no generalized way of applying such a technique. The presented paper addresses this issue by proposing a common feeding technique that can be applied to any antenna which is miniaturized using its symmetrical structure. The proposed technique enables feeding the halved structure to achieve wider and better impedance matching than the reported full-size antennas. The theory of characteristic modes is applied to quasi-mono-pole structures to get an insight of the ant...

  12. 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.

  13. Aspects of probe correction for odd-order probes in spherical near-field antenna measurements

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey N.; Breinbjerg, Olav

    2004-01-01

    Probe correction aspects for the spherical near-field antenna measurements are investigated. First, the spherical mode analyses of the radiated fields of several antennas are performed. It is shown that many common antennas are essentially so-called odd-order antennas. Second, the errors caused...... by the use of the first-order probe correction [1] for a rectangular waveguide probe, that is an odd-order antenna, are demonstrated. Third, a recently developed probe correction technique for odd-order probes is applied for the rectangular waveguide probe and shown to provide accurate results....

  14. Novel Applications of Lanthanoides as Analytical or Diagnostic Tools in the Life Sciences by ICP-MS-based Techniques

    Science.gov (United States)

    Müller, Larissa; Traub, Heike; Jakubowski, Norbert

    2016-11-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is a well-established analytical method for multi-elemental analysis in particular for elements at trace and ultra-trace levels. It has found acceptance in various application areas during the last decade. ICP-MS is also more and more applied for detection in the life sciences. For these applications, ICP-MS excels by a high sensitivity, which is independent of the molecular structure of the analyte, a wide linear dynamic range and by excellent multi-element capabilities. Furthermore, methods based on ICP-MS offer simple quantification concepts, for which usually (liquid) standards are applied, low matrix effects compared to other conventional bioanalytical techniques, and relative limits of detection (LODs) in the low pg g-1 range and absolute LODs down to the attomol range. In this chapter, we focus on new applications where the multi-element capability of ICP-MS is used for detection of lanthanoides or rare earth elements, which are applied as elemental stains or tags of biomolecules and in particular of antibodies.

  15. 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.

  16. The ACTS multibeam antenna

    Science.gov (United States)

    Regier, Frank A.

    1992-01-01

    The Advanced Communications Technology Satellite (ACTS) to be launched in 1993 is briefly introduced. Its multibeam antenna, consisting of electrically similar 30 GHz receive and 20 GHz transmit offset Cassegrain systems, both utilizing orthogonal polarizations, is described. Dual polarization is achieved by using one feed assembly for each polarization in conjunction with nested front and back subreflectors, the gridded front subreflector acting as a window for one polarization and a reflector for the other. The antennas produce spot beams with approximately 0.3 degree beamwidth and gains of approximately 50 dbi. High surface accuracy and high edge taper produce low sidelobe levels and high cross-polarization isolation. A brief description is given of several Ka-band components fabricated for ACTS. These include multiflare antenna feedhorns, beam-forming networks utilizing latching ferrite waveguide switches, a 30 GHz HEMT low-noise amplifier and a 20 GHz TWT power amplifier.

  17. The ACTS multibeam antenna

    Science.gov (United States)

    Regier, Frank A.

    1992-06-01

    The Advanced Communications Technology Satellite (ACTS) to be launched in 1993 is briefly introduced. Its multibeam antenna, consisting of electrically similar 30 GHz receive and 20 GHz transmit offset Cassegrain systems, both utilizing orthogonal polarizations, is described. Dual polarization is achieved by using one feed assembly for each polarization in conjunction with nested front and back subreflectors, the gridded front subreflector acting as a window for one polarization and a reflector for the other. The antennas produce spot beams with approximately 0.3 degree beamwidth and gains of approximately 50 dbi. High surface accuracy and high edge taper produce low sidelobe levels and high cross-polarization isolation. A brief description is given of several Ka-band components fabricated for ACTS. These include multiflare antenna feedhorns, beam-forming networks utilizing latching ferrite waveguide switches, a 30 GHz HEMT low-noise amplifier and a 20 GHz TWT power amplifier.

  18. Thermal imaging of plasma with a phased array antenna in QUEST

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Kishore, E-mail: mishra@triam.kyushu-u.ac.jp; Nagata, K.; Akimoto, R.; Banerjee, S. [IGSES, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Idei, H.; Zushi, H.; Hanada, K.; Hasegawa, M.; Nakamura, K.; Fujisawa, A.; Nagashima, Y.; Onchi, T.; Kuzmin, A. [RIAM, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Yamamoto, M. K. [Research Institute for Sustainable Humanosphere, Kyoto University, Uji 611-0011 (Japan)

    2014-11-15

    A thermal imaging system to measure plasma Electron Bernstein Emission (EBE) emanating from the mode conversion region in overdense plasma is discussed. Unlike conventional ECE/EBE imaging, this diagnostics does not employ any active mechanical scanning mirrors or focusing optics to scan for the emission cones in plasma. Instead, a standard 3 × 3 waveguide array antenna is used as a passive receiver to collect emission from plasma and imaging reconstruction is done by accurate measurements of phase and intensity of these signals by heterodyne detection technique. A broadband noise source simulating the EBE, is installed near the expected mode conversion region and its position is successfully reconstructed using phase array technique which is done in post processing.

  19. 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....

  20. 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

  1. 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...

  2. 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.

  3. 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

  4. Aperture optical antennas

    CERN Document Server

    Wenger, Jerome

    2014-01-01

    This contribution reviews the studies on subwavelength aperture antennas in the optical regime, paying attention to both the fundamental investigations and the applications. Section 2 reports on the enhancement of light-matter interaction using three main types of aperture antennas: single subwavelength aperture, single aperture surrounded by shallow surface corrugations, and subwavelength aperture arrays. A large fraction of nanoaperture applications is devoted to the field of biophotonics to improve molecular sensing, which are reviewed in Section 3. Lastly, the applications towards nano-optics (sources, detectors and filters) are discussed in Section 4.

  5. 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...

  6. 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.

  7. 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.

  8. Antenna and RF Subsystem Integration in Cellular Communications

    DEFF Research Database (Denmark)

    Herrero, Pablo; Bahramzy, Pevand; Svendsen, Simon;

    2014-01-01

    We discuss in this article a number of techniques that can be used to improve the RF performance on a mobile device. All those techniques rely on tight antenna and modem subsystem codesign. In a short introduction, the article outlines the need of these techniques, based on the advent of new...

  9. Diagnostic Development on NSTX

    Energy Technology Data Exchange (ETDEWEB)

    A.L. Roquemore; D. Johnson; R. Kaita; et al

    1999-12-16

    Diagnostics are described which are currently installed or under active development for the newly commissioned NSTX device. The low aspect ratio (R/a less than or equal to 1.3) and low toroidal field (0.1-0.3T) used in this device dictate adaptations in many standard diagnostic techniques. Technical summaries of each diagnostic are given, and adaptations, where significant, are highlighted.

  10. A Transient UWB Antenna Array Used with Complex Impedance Surfaces

    Directory of Open Access Journals (Sweden)

    A. Godard

    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.

  11. Rectangular and Circular Antenna Design on Thick Substrate

    CERN Document Server

    kumar, Harsh

    2010-01-01

    Millimeter wave technology being an emerging area is still very undeveloped. A substantial research needs to be done in this area as its applications are numerous. In the present endeavor, a rectangular patch antenna is designed on thick substrate and simulated using SONNET software, also a novel analysis technique is developed for circular patch antenna for millimeter wave frequency. The antenna is designed at 39 GHz on thick substrate and has been analyzed and simulated.The results of the theoretical analysis are in good agreement with the simulated results.

  12. Validation of Emulated Omnidirectional Antenna Output Using Directive Antenna Data

    DEFF Research Database (Denmark)

    Hejselbæk, Johannes; Karstensen, Anders; Nielsen, Jesper Ødum

    2016-01-01

    In this paper, we present validation of a method for constructing a virtual omnidirectional antenna in the azimuth plane. The virtual omnidirectional antenna utilizes a combination of data from directive horn antennas. The aim is to utilize the high gain of the horn antenna to improve the dynamic...... range of channel sounding measurements conducted in the centimeter and millimeter wave bands. The resulting complex impulse response from the virtual omnidirectional antenna is used to find the power-delay-profile (PDP). This is then compared to measurements conducted at the same time using a real...... omnidirectional antenna. The validation shows that the synthesized omnidirectional is capable of predicting main components and the slope of the PDP. Further, it is shown that by choosing angular sampling steps corresponding to the half power beam width (HPBW) of the used antenna similar power levels can...

  13. 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...

  14. 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…

  15. 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

  16. Quartz antenna with hollow conductor

    Science.gov (United States)

    Leung, Ka-Ngo; Benabou, Elie

    2002-01-01

    A radio frequency (RF) antenna for plasma ion sources is formed of a hollow metal conductor tube disposed within a glass tube. The hollow metal tubular conductor has an internal flow channel so that there will be no coolant leakage if the outer glass tube of the antenna breaks. A portion of the RF antenna is formed into a coil; the antenna is used for inductively coupling RF power to a plasma in an ion source chamber. The antenna is made by first inserting the metal tube inside the glass tube, and then forming the glass/metal composite tube into the desired coil shape.

  17. 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.

  18. Millimeter and Submillimeter-Wave Integrated Horn Antenna Schottky Receivers.

    Science.gov (United States)

    Ali-Ahmad, Walid Youssef

    1993-01-01

    Fundamental Schottky-diode mixers are currently used in most millimeter-wave receivers above 100GHz. The mixers use either a whisker-contacted diode or a planar Schottky diode suspended in a machined waveguide with an appropriate RF matching network. However, waveguide mounts are very expensive to machine for frequencies above 200GHz. Also, the whisker-contacted structure is not compatible with integrated mixers which represent the leading technology used for millimeter- and submillimeter-wave applications such as plasma diagnostics imaging arrays, radiometers, and anti-collision radars. In this work, a novel quasi-integrated horn antenna has been used for the receiver antenna. This antenna has a high gain and a high Gaussian coupling efficiency (97%), similar to machined scalar feed horns, but with the advantage of being easily fabricated up to at least 1.5THz. The quasi-integrated horn antenna is based on the integrated horn antenna structure. The integrated horn antenna consists of a pyramidal cavity with a 70^circ flare angle etched anisotropically in silicon. The cavity focuses the incoming energy on dipole-probe suspended on a membrane inside the horn. The integrated horn antenna does not suffer from dielectric losses or substrate mode losses since the feeding dipole antenna is integrated on a very thin dielectric layer. The mixer circuit, along with the feed dipole, are both integrated on the membrane wafer. The mixer diode is the University of Virginia surface channel planar diode which has a low parasitic capacitance. The diode is epoxied directly at the dipole apex without the need for an RF matching network, and with no mixer tuning required. At 92GHz,the DSB antenna-mixer conversion loss and noise temperature are 5.5dB and 770K, respectively. This represents the best reported results to this date for a quasi-optical mixer with a planar diode, at room temperature. At 335GHz, the DSB antenna-mixer noise temperature is 1750K and it is within 1dB of the

  19. Experience with the operation of the European ALMA antennas

    Science.gov (United States)

    Stanghellini, Stefano; Laing, Robert; Rossi, Silvio; Wild, Wolfgang

    2016-07-01

    The 25 European antennas of ALMA were delivered by ESO to the ALMA project in Chile between April 2011 and September 2013. Their combined time of operation is already significant and allows us to draw conclusions regarding their ability to fulfil the original specification, in terms of both scientific performance and operational availability. In this paper, we will summarize the experience gained during the past five years of operation. We will characterize the performance of the antennas in routine operation and compare with the data obtained during acceptance testing. We will also describe the few technical issues experienced while operating at 5000m and the way in which these were treated during these first years of operation. We will evaluate the effective reliability obtained in service based on field data and draw some conclusions as to the way in which reliability and maintainability aspects were covered during the process which led to the final design of the antenna. We will discuss the smart use of software to handle redundancy in a flexible way and to exclude failed components without affecting overall antenna operability. The use of low-level diagnostics enabled by remote access allows us to shorten the trouble-shooting cycle and to optimise physical interventions on the antennas. Finally, the paper will cover Antenna maintenance manuals edited using an industrial interactive standard. It will be explained why this advanced and innovative concept has not achieved the success that was expected, and why the traditional form is preferred at the ALMA Observatory.

  20. 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

  1. Protecting Superconducting HTS-Antennas by Meta-Material Cloaks

    Science.gov (United States)

    2014-04-30

    equal to one- tenth of the operating wavelength (≤ λ/10). For example, the largest dimensions for a dipole, a loop, and a microstrip patch antenna are...demonstrated circuits exhibit significant loss, which can be reduced by using superconductors. Ricci et al. [37-39] investigated superconducting metamaterials...Peiniger, H. Piel, A. Pischke, and G. Splitt, “Miniaturized high-temperature superconductor microstrip patch antenna,” Microwave Theory and Techniques

  2. The analysis of reactively loaded microstrip antennas by finite difference time domain modelling

    Science.gov (United States)

    Hilton, G. S.; Beach, M. A.; Railton, C. J.

    1990-01-01

    In recent years, much interest has been shown in the use of printed circuit antennas in mobile satellite and communications terminals at microwave frequencies. Although such antennas have many advantages in weight and profile size over more conventional reflector/horn configurations, they do, however, suffer from an inherently narrow bandwidth. A way of optimizing the bandwidth of such antennas by an electronic tuning technique using a loaded probe mounted within the antenna structure is examined, and the resulting far-field radiation patterns are shown. Simulation results from a 2D finite difference time domain (FDTD) model for a rectangular microstrip antenna loaded with shorting pins are given and compared to results obtained with an actual antenna. It is hoped that this work will result in a design package for the analysis of microstrip patch antenna elements.

  3. 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...

  4. DTU-ESA millimeter-wave validation standard antenna – requirements and design

    DEFF Research Database (Denmark)

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

    2014-01-01

    stability over a given operational temperature range. In addition, VAST antennas must possess electrical characteristics that are typical for satellite antennas and challenging to measure. A multi-band millimeter-wave VAST (mm-VAST) antenna for the K/Ka-bands and Q/V bands is currently under development......Inter-comparisons and validations of antenna measurement ranges are useful tools allowing the detection of various problems in the measurement procedures, thus leading to improvements of the measurement accuracy and facilitating better understanding of the measurement techniques. The maximum value...... from a validation campaign is achieved when a dedicated Validation Standard (VAST) antenna specifically designed for this purpose is available. The driving requirements to VAST antennas are their mechanical stability with respect to any orientation of the antenna in the gravity field and thermal...

  5. Stretchable and reversibly deformable radio frequency antennas based on silver nanowires.

    Science.gov (United States)

    Song, Lingnan; Myers, Amanda C; Adams, Jacob J; Zhu, Yong

    2014-03-26

    We demonstrate a class of microstrip patch antennas that are stretchable, mechanically tunable, and reversibly deformable. The radiating element of the antenna consists of highly conductive and stretchable material with screen-printed silver nanowires embedded in the surface layer of an elastomeric substrate. A 3-GHz microstrip patch antenna and a 6-GHz 2-element patch array are fabricated. Radiating properties of the antennas are characterized under tensile strain and agree well with the simulation results. The antenna is reconfigurable because the resonant frequency is a function of the applied tensile strain. The antenna is thus well suited for applications like wireless strain sensing. The material and fabrication technique reported here could be extended to achieve other types of stretchable antennas with more complex patterns and multilayer structures.

  6. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

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

  7. Integrated Solar Panel Antennas for Cube Satellites

    OpenAIRE

    Mahmoud, Mahmoud N.

    2010-01-01

    This thesis work presents an innovative solution for small satellite antennas by integrating slot antennas and solar cells on the same panel to save small satellite surface real estate and to replace deployed wire antennas for certain operational frequencies. The two main advantages of the proposed antenna are: 1) the antenna does not require an expensive deployment mechanism that is required by dipole antennas; 2) the antenna does not occupy as much valuable surface real estate as patch ante...

  8. A Reconfigurable Radiation Pattern Annular Slot Antenna

    OpenAIRE

    Aziz, NA; Radhi, A; Nilavalan, R

    2016-01-01

    This paper contemplate a theoretical analysis of a pattern reconfigurable antenna using annular slot antenna operating in low frequency. A shorting pin is inserted to allow the annular slot antenna to have an omnidirectional radiation pattern like a monopole antenna. The reconfigurable antenna consists of numerous metal cylinders arranged around the annular slot antenna. By controlling pin diodes associated with the metal cylinders, the antenna is capable of working up in different dire...

  9. Plasma-Surface Interactions and RF Antennas

    Science.gov (United States)

    Jenkins, Thomas; Smithe, D. N.; Beckwith, K.; Davidson, B. D.; Kruger, S. E.; Pankin, A. Y.; Roark, C. M.

    2015-11-01

    Implementation of recently developed finite-difference time-domain (FDTD) modeling techniques on high-performance computing platforms allows RF power flow, and antenna near- and far-field behavior, to be studied in realistic experimental ion-cyclotron resonance heating scenarios at previously inaccessible levels of resolution. We present results and 3D animations of high-performance (10k-100k core) FDTD simulations of Alcator C-Mod's field-aligned ICRF antenna on the Titan supercomputer, considering (a) the physics of slow wave excitation in the immediate vicinity of the antenna hardware and in the scrape-off layer for various edge densities, and (b) sputtering and impurity production, as driven by self-consistent sheath potentials at antenna surfaces. Related research efforts in low-temperature plasma modeling, including the use of proper orthogonal decomposition methods for PIC/fluid modeling and the development of plasma chemistry tools (e.g. a robust and flexible reaction database, principal path reduction analysis capabilities, and improved visualization options), will also be summarized. Supported by U.S. DoE SBIR Phase I/II Award DE-SC0009501 and ALCC/OLCF.

  10. Research Progress on Diagnostic Techniques of Foot-and-Mouth Disease%蹄疫诊断技术研究进展

    Institute of Scientific and Technical Information of China (English)

    武刚; 王洪梅; 刘晓; 宋玲玲; 陈莉莉; 仲跻峰; 何洪彬

    2011-01-01

    口蹄疫是偶蹄动物的一种急性、热性、高度接触性传染病,可使世界范围内的畜牧业遭受严重的经济损失,及时准确的诊断是防制口蹄疫的重要环节.诊断口蹄疫的方法可分为临床诊断、生物学实验、血清学诊断、分子生物学检测技术及环介导等五类技术,每类技术中又包括数个具体技术.论文对其优缺点进行比较,并对口蹄疫诊断技术研究进行了展望.%Foot and mouth disease is an acute, febrile, highly contagious disease of Cloven-hoofed animals. It may cause the animal husbandry to suffer the serious economic loss in the worldwide scale. The prompt accurate diagnosis is important to fight against foot-and-mouth disease. There are several diagnosis methods of foot-and-mouth disease,such as: the clinical diagnosis, the biology experiment, the serological diagnosis, molecular biology techniques and five other Central-mediated technology. Each type of technology also includes several specific technologies. The advantages and disadvantages, as well as the methods were compared, and the development of foot and mouth disease diagnostic techniques was forecasted in this paper.

  11. 奶牛隐性乳房炎诊断技术研究进展%Research Progress on Diagnostic Techniques of Recessive Mastitis in Dairy Cows

    Institute of Scientific and Technical Information of China (English)

    马金梅; 迟良; 邹明; 刘焕奇

    2016-01-01

    At the present time,the recessive mastitis has become one of the common diseases with high incidence in dairy cows,resulting in serious harm and great financial loss in dairy industry. Major diagnostic techniques and methods of the disease were compared and analyzed in this article,including cell count,PH-value test of milk,conductivity detection of milk,milk bacterial culture,PCR assay and MTT test,so as to provide guidance for better selection and further study of the diagnosis method for recessive mastitis.%目前,奶牛隐性乳房炎已成为奶牛常见的多发病,给奶牛养殖业带来了严重危害和巨大经济损失。本文对当前该病的主要诊断技术与方法,包括体细胞计数法、乳汁PH检验法、乳汁电导率检测法、乳汁细菌培养、PCR检测方法、MTT检测法等,进行了对比阐述,以期为选择和研究奶牛隐性乳房炎相关诊断方法提供借鉴。

  12. Practical X-ray diagnostics orthopedics and trauma surgery. Indication, adjustment technique and radiation protection; Praktische Roentgendiagnostik Orthopaedie und Unfallchirurgie. Indikation, Einstelltechnik, Strahlenschutz

    Energy Technology Data Exchange (ETDEWEB)

    Flechtenmacher, Johannes [Ortho-Zentrum am Ludwigsplatz, Karlsruhe (Germany); Sabo, Desiderius [Klinik St. Elisabeth, Heidelberg (Germany). Sportopaedic Heidelberg

    2014-07-01

    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.

  13. Miniature implantable antennas for biomedical telemetry: from simulation to realization.

    Science.gov (United States)

    Kiourti, Asimina; Costa, Jorge R; Fernandes, Carlos A; Santiago, André G; Nikita, Konstantina S

    2012-11-01

    We address numerical versus experimental design and testing of miniature implantable antennas for biomedical telemetry in the medical implant communications service band (402-405 MHz). A model of a novel miniature antenna is initially proposed for skin implantation, which includes varying parameters to deal with fabrication-specific details. An iterative design-and-testing methodology is further suggested to determine the parameter values that minimize deviations between numerical and experimental results. To assist in vitro testing, a low-cost technique is proposed for reliably measuring the electric properties of liquids without requiring commercial equipment. Validation is performed within a specific prototype fabrication/testing approach for miniature antennas. To speed up design while providing an antenna for generic skin implantation, investigations are performed inside a canonical skin-tissue model. Resonance, radiation, and safety performance of the proposed antenna is finally evaluated inside an anatomical head model. This study provides valuable insight into the design of implantable antennas, assessing the significance of fabrication-specific details in numerical simulations and uncertainties in experimental testing for miniature structures. The proposed methodology can be applied to optimize antennas for several fabrication/testing approaches and biotelemetry applications.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Review on High Gain Conical Horn Antenna for Short-Range Communications

    Directory of Open Access Journals (Sweden)

    Priyanka Bhagwat

    2013-11-01

    Full Text Available Horn antennas are very popular at UHF (300 MHz-3 GHz and higher frequencies ( as high as 140 GHz. Horn antennas often have a directional radiation pattern with a high antenna gain, which can range up to 25 dB in some cases, with 10-20 dB being typical. Horn antennas have a wide impedance bandwidth, implying that the input impedance is slowly varying over a wide frequency range. The bandwidth for practical horn antennas can be of the order of 20:1 (for instance, operating from 1 GHz-20 GHz, with a 10:1 bandwidth being common. The gain of horn antennas often increases as the frequency of operation is increased. This is because the size of the horn aperture is measured in wavelengths; at higher frequencies the horn antenna is "electrically larger" because high frequency has a smaller wavelength. Horn antennas have very little loss, so the directivity of a horn is roughly equal to its gain. In this paper, we will present review about conical horn antenna which uses hybrid technique and provides high gain at frequencies ranging 3GHz keeping its size within limits. Also, literature survey will demostrate other reference papers will includes horn antennas using different techniques and used for various applications.

  19. 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...

  20. 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...

  1. Validation of multiple diagnostic techniques to detect Cryptosporidium sp. and Giardia sp. in free-ranging western lowland gorillas (Gorilla gorilla gorilla) and observations on the prevalence of these protozoan infections in two populations in Gabon.

    Science.gov (United States)

    van Zijll Langhout, Martine; Reed, Patricia; Fox, Mark

    2010-06-01

    Anthropozoonotic diseases threaten the survival of western lowland gorillas (Gorilla gorilla gorilla). Use of accurate diagnostic techniques in gorilla health monitoring contributes to the conservation of gorillas by providing robust information for appropriate management decisions. To identify suitable protozoa diagnostic techniques for wild gorillas, 95 fecal specimens were collected in Lopé National Park and east of Moukalaba-Doudou National Park in Gabon, areas with high and low levels of human activity, respectively. The samples were examined for Cryptosporidium sp. and Giardia sp. by using the following diagnostic techniques: a commercially available immunofluorescent antibody test kit, Merifluor, and a rapid immune-assay, ImmunoCard STAT!, to detect Cryptosporidium sp. and Giardia sp., and a modified Ziehl-Neelsen stain to detect Cryptosporidium sp. oocysts. The results obtained from the Merifluor test, considered the "gold standard" in human studies, were used to estimate the prevalence of Cryptosporidium sp. and Giardia sp. infections in Lopé National Park (19.0% and 22.6%, respectively) and east of Moukalaba-Doudou National Park (0% and 9.1%, respectively). The difference in prevalence in both areas may be associated with differing levels of anthropogenic disturbance. The sensitivity and specificity of the latter two diagnostic techniques were calculated by using the Merifluor test as a control. The ImmunoCard STAT! was found suitable for Giardia sp. antigen detection (specific but not sensitive) and inappropriate for Cryptosporidium sp. antigen detection (not specific or sensitive). The modified Ziehl-Neelsen stain was found to be highly specific but not sensitive in the detection of Cryptosporidium sp. oocysts. These results underline the necessity of using ancillary tests and concentration methods to correctly identify positive samples. This is the first report of Cryptosporidium sp. and Giardia sp. infections in free-ranging western lowland gorillas

  2. Circuit realization microwave antennas-oscillator on strip antennas

    OpenAIRE

    Golynskyy, V. D.; Prudyus, I. N.

    2009-01-01

    Showing special feature of development circuitries microwave transistors antennasoscillator on strip dielectric-resonator-antennas. Showing circuitries and technical characteristics of developed microwave antennasoscillator on strip.

  3. Tilting A Small Reflector For Vernier Pointing Of A Large Antenna

    Science.gov (United States)

    Veruttipong, Watt; Bathker, Dan A.

    1995-01-01

    Simple vernier pointing technique devised to facilitate scanning beam pointing of large paraboloidal reflector so line of sight of antenna sweeps out narrow cone about fixed axis (conical scan, also known as "conscan" in art). Scan effected by one of relatively small beam-waveguide reflectors or mirrors that couple signals between antenna and distant transmitting and/or receiving electronic circuits. Easier to tilt small mirror than to tilt massive antenna structure.

  4. Miniaturization of Spherical Magnetodielectric Antennas

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle

    The fundamental limitations in performance of electrically small antennas (ESAs) - and how far these may be approached - have been of great interest for over a century. Particularly over the past few decades, it has become increasingly relevant and important, to approach these limits in view...... to the important antenna parameters of radiation efficiency e and impedance bandwidth. For single-mode antennas the fundamental minimum Q is the Chu lower bound. In this Ph.D. dissertation, the topic is miniaturization of spherical antennas loaded by an internal magnetodielectric core. The goal is to determine......, quantify, and assess the effects of an internal material loading upon antenna performance, including its potentials towards miniaturization. Emphasis have been upon performing an exhaustive and exact analysis of rigorous validity covering a large class of spherical antennas. In the context of this study...

  5. A Compact UWB Diversity Antenna

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2014-01-01

    Full Text Available A compact printed ultrawideband (UWB diversity antenna with a size of 30 mm × 36 mm operating at a frequency range of 3.1–10.6 GHz is proposed. The antenna is composed of two semielliptical monopoles fed by two microstrip lines. Two semicircular slots, two rectangular slots, and one stub are introduced in the ground plane to adjust the impedance bandwidth of the antenna and improve the isolation between two feeding ports. The simulated and measured results show that impedance bandwidth of the proposed antenna can cover the whole UWB band with a good isolation of < −15 dB. The radiation patterns, peak antenna gain, and envelope correlation coefficient are also measured and discussed. The measured results show that the proposed antenna can be a good candidate for some portable MIMO/diversity UWB applications.

  6. Antenna structure with distributed strip

    Science.gov (United States)

    Rodenbeck, Christopher T.

    2008-03-18

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  7. Antenna for Ultrawideband Channel Sounding

    DEFF Research Database (Denmark)

    Zhekov, Stanislav Stefanov; Tatomirescu, Alexandru; Pedersen, Gert F.

    2016-01-01

    A novel compact antenna for ultrawideband channel sounding is presented. The antenna is composed of a symmetrical biconical antenna modified by adding a cylinder and a ring to each cone. A feeding coaxial cable is employed during the simulations in order to evaluate and reduce its impact...... on the antenna performance. The optimized antenna demonstrates S11 below -10 dB and a stable omnidirectional radiation pattern robust against the cable effect over the frequency band 1.5-41 GHz despite its compactness (the maximum electrical dimension is of 0.29max, where max is the free space wavelength...... at the lowest frequency of operation). A prototype of the antenna is fabricated and tested. The simulated and measured S11 are in a good agreement. Measured radiation patterns confirm the pattern stability in terms of the direction of maximum radiation and 3 dB beamwidth....

  8. 3D Inkjet Printed Helical Antenna with Integrated Lens

    KAUST Repository

    Farooqui, Muhammad F.

    2016-08-30

    The gain of an antenna can be enhanced through the integration of a lens, although this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, through a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB, which provides a peak gain of about 12.9 dBi at 8.8 GHz. The 3-dB axial ratio (AR) bandwidth of the antenna with the lens is 5.5%. This work also reports the complete characterization of this new process in terms of minimum features sizes and achievable conductivities. Due to monolithic integration of the lens through a fully printed process, this antenna configuration offers high gain performance by using a low cost and rapid fabrication technique. © 2016 IEEE.

  9. Rotorcraft Diagnostics

    Science.gov (United States)

    Haste, Deepak; Azam, Mohammad; Ghoshal, Sudipto; Monte, James

    2012-01-01

    Health management (HM) in any engineering systems requires adequate understanding about the system s functioning; a sufficient amount of monitored data; the capability to extract, analyze, and collate information; and the capability to combine understanding and information for HM-related estimation and decision-making. Rotorcraft systems are, in general, highly complex. Obtaining adequate understanding about functioning of such systems is quite difficult, because of the proprietary (restricted access) nature of their designs and dynamic models. Development of an EIM (exact inverse map) solution for rotorcraft requires a process that can overcome the abovementioned difficulties and maximally utilize monitored information for HM facilitation via employing advanced analytic techniques. The goal was to develop a versatile HM solution for rotorcraft for facilitation of the Condition Based Maintenance Plus (CBM+) capabilities. The effort was geared towards developing analytic and reasoning techniques, and proving the ability to embed the required capabilities on a rotorcraft platform, paving the way for implementing the solution on an aircraft-level system for consolidation and reporting. The solution for rotorcraft can he used offboard or embedded directly onto a rotorcraft system. The envisioned solution utilizes available monitored and archived data for real-time fault detection and identification, failure precursor identification, and offline fault detection and diagnostics, health condition forecasting, optimal guided troubleshooting, and maintenance decision support. A variant of the onboard version is a self-contained hardware and software (HW+SW) package that can be embedded on rotorcraft systems. The HM solution comprises components that gather/ingest data and information, perform information/feature extraction, analyze information in conjunction with the dependency/diagnostic model of the target system, facilitate optimal guided troubleshooting, and offer

  10. Simulation and analysis of antennas radiating in a complex environment

    Science.gov (United States)

    Kim, J. J.; Burnside, W. D.

    1986-01-01

    A numerical procedure for computing the high-frequency radiation patterns of antennas mounted on curved surfaces is described. The procedure utilizes the uniform geometrical theory of diffraction to examine the antenna system's performance, which is dependent on antenna radiation patterns. Composite ellipsoid models of fuselage shapes are developed and the formation of geodesic paths on the models is studied; the shape of the fuselage affects the radiation patterns. The actual field radiated by the source and scattered by the structure is calculated using the ray field technique. The numerical solution is applied to the analysis of the antenna radiation patterns of a military aircraft, private aircraft, and the Space Shuttle orbiter. Good correlation between the calculated and measured radiation patterns is noted verifying the usefulness and accuracy of the numerical procedure.

  11. Flexible sixteen monopole antenna array for microwave breast cancer detection.

    Science.gov (United States)

    Bahrami, H; Porter, E; Santorelli, A; Gosselin, B; Popovic, M; Rusch, L A

    2014-01-01

    Radar based microwave imaging (MI) has been widely studied for breast cancer detection in recent times. Sensing dielectric property differences of tissues over a wide frequency band has been made possible by ultra-wideband (UWB) techniques. In this paper, a flexible, compact monopole antenna on a 100 μm Kapton polyimide is designed, using a high frequency structure simulator (HFSS), to be in contact with biological breast tissues over the 2-5GHz frequency range. The antenna parameters are optimized to obtain a good impedance match over the required frequency range. The designed antenna size is 18mm × 18mm. Further, a flexible conformal 4×4 ultra-wideband antenna array, in a format similar to that of a bra, was developed for a radar-based breast cancer detection system.

  12. MULTILAYER MICROSTRIP ANTENNA QUALITY FACTOR OPTIMIZATION FOR BANDWIDTH ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    M.C. SRIVASTAVA

    2012-12-01

    Full Text Available The impedance bandwidth, one of the important characteristics of microstrip patch antennas, can be significantly improved by using a multilayer dielectric configuration. In this paper the focus is on bandwidth enhancement technique of a multilayer patch antenna for X-band applications. In order to enhance the bandwidth, antenna losses are contained by controlling those quality factors which can have a significant impact on the bandwidth for a given permittivity and thickness of the substrate. This has been achieved by conformal transformation of the multidielectric microstrip antenna. For the ease of analysis Wheelers transformation is used to map the complex permittivity of a multilayer substrate to a single layer. Method of Moments and Finite Difference Time Domain approaches are used for the computation of results.

  13. Integrated horn antennas for millimeter-wave applications

    Science.gov (United States)

    Rebeiz, Gabriel M.; Katehi, Linda P. B.; Ali-Ahmad, Walid Y.; Eleftheriades, George V.; Ling, Curtis C.

    1992-02-01

    The development of integrated horn antennas since their introduction in 1987 is reviewed. The integrated horn is fabricated by suspending a dipole antenna, on a thin dielectric membrane, in a pyramidal cavity etched in silicon. Recent progress has resulted in optimized low- and high-gain designs, with single and double polarization for remote-sensing and communication applications. A full-wave analysis technique has resulted in an integrated antenna with performance comparable to that of waveguide-fed corrugated-horn antennas. The integrated horn design can be extended to large arrays, for imaging and phased-array applications, while leaving plenty of room for the RF and IF processing circuitry. Theoretical and experimental results at microwave frequencies and at 90 GHz, 240 GHz, and 802 GHz are presented.

  14. Wideband and UWB Antennas for Wireless Applications: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Renato Cicchetti

    2017-01-01

    Full Text Available A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible, and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc. and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems.

  15. Electromagnetics of body area networks antennas, propagation, and RF systems

    CERN Document Server

    Werner, Douglas H

    2016-01-01

    The book is a comprehensive treatment of the field, covering fundamental theoretical principles and new technological advancements, state-of-the-art device design, and reviewing examples encompassing a wide range of related sub-areas. In particular, the first area focuses on the recent development of novel wearable and implantable antenna concepts and designs including metamaterial-based wearable antennas, microwave circuit integrated wearable filtering antennas, and textile and/or fabric material enabled wearable antennas. The second set of topics covers advanced wireless propagation and the associated statistical models for on-body, in-body, and off-body modes. Other sub-areas such as efficient numerical human body modeling techniques, artificial phantom synthesis and fabrication, as well as low-power RF integrated circuits and related sensor technology are also discussed. These topics have been carefully selected for their transformational impact on the next generation of body-area network systems and beyo...

  16. Terahertz Coded Aperture Mask using a Vanadium Dioxide Bowtie Antenna Array

    CERN Document Server

    Nadri, Souheil; Kittiwatanakul, Lin; Arsenovic, Alex; Lu, Jiwei; Wolf, Stu; Weikle, Robert M

    2015-01-01

    Terahertz imaging systems have received substantial attention from the scientific community for their use in astronomy, spectroscopy, plasma diagnostics and security. One approach to designing such systems is to use focal plane arrays. Although the principle of these systems is straightforward, realizing practical architectures has proven deceptively difficult. A different approach to imaging consists of spatially encoding the incoming flux of electromagnetic energy prior to detection using a reconfigurable mask. This technique is referred to as coded aperture or Hadamard imaging. This paper details the design, fabrication and testing of a prototype coded aperture mask operating at WR 1.5 (500 to 750 GHz) that uses the switching properties of vanadium dioxide (VO2). The reconfigurable mask consists of bowtie antennas with vanadium dioxide VO2 elements at the feed points. From the symmetry, a unit cell of the array can be represented by an equivalent waveguide whose dimensions limit the maximum operating frequ...

  17. A distributed array antenna system

    Science.gov (United States)

    Shaw, R.; Kovitz, J.

    1986-01-01

    The Space Station communication system will use microwave frequency radio links to carry digitized information from sender to receiver. The ability of the antenna system to meet stringent requirements on coverage zones, multiple users, and reliability will play an important part in the overall multiple access communication system. This paper will describe the configuration of a multibeam conformal phased array antenna and the individual microwave integrated components incoporated into this antenna system.

  18. Optical antenna gain. 2: receiving antennas.

    Science.gov (United States)

    Degnan, J J; Klein, B J

    1974-10-01

    Expressions are derived for the gain of a centrally obscured, circular optical antenna when used as the collecting and focusing optics in a laser receiver which include losses due to (1) blockage of the incoming light by the central obscuration, (2) the spillover of energy at the detector, and (3) the effect of local oscillator distribution in the case of heterodyne or homodyne detection. Numerical results are presented for direct detection and for three types of local oscillator distributions (uniform, Gaussian, and matched) in the case of heterodyne or homodyne detection. The results are presented in several graphs that allow the rapid evaluation of receiver gain for an arbitrary set of telescope and detector parameters. It is found that, for uniform illumination by the LO, the optimum SNR is obtained when the detector radius is approximately 0.74 times the Airy disk radius. The use of an optimized Gaussian (spot size = 0.46 times the Airy disk radius) improves the receiver gain by less than 1 dB. Theuse results are insensitive to the size of the central obscuration.

  19. IR thermography diagnostics for the WEST project

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, X., E-mail: xavier.courtois@cea.fr [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Aumeunier, M.H. [OPTIS, ZE de La Farlède, F-83078 Toulon Cedex 9 (France); Joanny, M.; Roche, H.; Micolon, F.; Salasca, S.; Balorin, C.; Jouve, M. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France)

    2014-10-15

    Highlights: • The WEST project requires a set of three infrared diagnostics. • The tungsten divertor will be monitored by the existing diagnostic renewed. • The antennas monitoring require the development of an innovative diagnostic. • A fiber bundle will be used as image transport for the antennas monitoring. • A wide angle tangential view of the upper divertor and the first wall is studied. - Abstract: To operate long plasma discharge in tokamak equipped with actively cooled plasma facing components (PFC), infrared (IR) thermography is a key diagnostic. Indeed IR data are used for both PFC safety monitoring, to avoid material degradation and water leak, and various physics studies on plasma-wall interaction. The IR monitoring is becoming even more crucial with today metallic PFCs. This is the case for the WEST project (Tungsten (W) Environment for Steady State Tokamak), which aims at installing a W divertor in Tore Supra (TS), in order to operate the 1st tokamak with a full W actively cooled divertor in long plasma discharges. The IR thermography system for the WEST project described in this paper will consist of a set of 3 different diagnostics: (1) Six cameras located in upper ports viewing the full W divertor, which reuse a part of the existing diagnostic of TS. (2) Five novel views located behind the inner protection panels for the antennas monitoring, based on an innovative imaging fibers bundle technology. (3) A tangential wide angle view located in a median port, for the upper divertor and first wall monitoring.

  20. Antenna arrays a computational approach

    CERN Document Server

    Haupt, Randy L

    2010-01-01

    This book covers a wide range of antenna array topics that are becoming increasingly important in wireless applications, particularly in design and computer modeling. Signal processing and numerical modeling algorithms are explored, and MATLAB computer codes are provided for many of the design examples. Pictures of antenna arrays and components provided by industry and government sources are presented with explanations of how they work. Antenna Arrays is a valuable reference for practicing engineers and scientists in wireless communications, radar, and remote sensing, and an excellent textbook for advanced antenna courses.

  1. Spiral Microstrip Antenna with Resistance

    Science.gov (United States)

    Shively, David G. (Inventor)

    1998-01-01

    A spiral microstrip antenna having resistor elements embedded in each of the spiral arms is provided. The antenna is constructed using a conductive back plane as a base. The back plane supports a dielectric slab having a thickness between one-sixteenth and one-quarter of an inch. A square spiral, having either two or four arms, is attached to the dielectric slab. Each arm of the spiral has resistor elements thereby dissipating an excess energy not already emitted through radiation. The entire configuration provides a thin, flat, high gain, wide bandwidth antenna which requires no underlying cavity. The configuration allows the antenna to be mounted conformably on an aircraft surface.

  2. Taenia solium porcine cysticercosis in Madagascar: Comparison of immuno-diagnostic techniques and estimation of the prevalence in pork carcasses traded in Antananarivo city.

    Science.gov (United States)

    Porphyre, V; Betson, M; Rabezanahary, H; Mboussou, Y; Zafindraibe, N J; Rasamoelina-Andriamanivo, H; Costard, S; Pfeiffer, D U; Michault, A

    2016-03-30

    Taenia solium cysticercosis was reported in official veterinary and medical statistics to be highly prevalent in pigs and humans in Madagascar, but few estimates are available for pigs. This study aimed to estimate the seroprevalence of porcine cysticercosis among pigs slaughtered in Antananarivo abattoirs. Firstly, the diagnostic performance of two antigen-ELISA techniques (B158B60 Ag-ELISA and HP10 Ag-ELISA) and an immunoblotting method were compared with meat inspection procedures on a sample of pigs suspected to be infected with (group 1; n=250) or free of (group 2; n=250) T. solium based on direct veterinary inspection in Madagascar. Sensitivity and specificity of the antigen ELISAs were then estimated using a Bayesian approach for detection of porcine cysticercosis in the absence of a gold standard. Then, a third set of pig sera (group 3, n=250) was randomly collected in Antananarivo slaughterhouses and tested to estimate the overall prevalence of T. solium contamination in pork meat traded in Antananarivo. The antigen ELISAs showed a high sensitivity (>84%), but the B158B60 Ag-ELISA appeared to be more specific than the HP10 Ag-ELISA (model 1: 95% vs 74%; model 2: 87% vs 71%). The overall prevalence of porcine cysticercosis in Antananarivo slaughterhouses was estimated at 2.3% (95% credibility interval [95%CrI]: 0.09-9.1%) to 2.6% (95%CrI: 0.1-10.3%) depending on the model and priors used. Since the sample used in this study is not representative of the national pig population, village-based surveys and longitudinal monitoring at slaughter are needed to better estimate the overall prevalence, geographical patterns and main risk factors for T. solium contamination, in order to improve control policies.

  3. Use of sting-response techniques for simulate diagnostics in human esophagus; Uso de tecnicas estimulo-respuesta para simular diagnosticos en esofago humano

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, I.; Gonzalez, Y.; Valdes, L.; Alfonso, J.A.; Estevez, E. [Facultad de Quimica Farmacia, Universidad Central de Las Villas (Cuba)

    2003-07-01

    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)

  4. Small Antennas for Wireless Micro-Systems

    OpenAIRE

    Rainer Wansch

    2002-01-01

    This paper will describe the topology of wireless micro-systems networks and some of their key components. In particular we will deal with the antennas: loops, helices, F-antennas, patches and dielectrically loaded antennas.

  5. Ferrite attenuator modulation improves antenna performance

    Science.gov (United States)

    Hooks, J. C.; Larson, S. G.; Shorkley, F. H.; Williams, B. T.

    1970-01-01

    Ferrite attenuator inserted into appropriate waveguide reduces the gain of the antenna element which is causing interference. Modulating the ferrite attenuator to change the antenna gain at the receive frequency permits ground tracking until the antenna is no longer needed.

  6. Antennas and Receivers in Radio Interferometry

    CERN Document Server

    Hunter, Todd R

    2016-01-01

    The primary antenna elements and receivers are two of the most important components in a synthesis telescope. Together they are responsible for locking onto an astronomical source in both direction and frequency, capturing its radiation, and converting it into signals suitable for digitization and correlation. The properties and performance of antennas and receivers can affect the quality of the synthesized images in a number of fundamental ways. In this lecture, their most relevant design and performance parameters are reviewed, with emphasis on the current ALMA and VLA systems. We discuss in detail the shape of the primary beam and the components of aperture efficiency, and we present the basics of holography, pointing, and servo control. On receivers, we outline the use of amplifiers and mixers both in the cryogenic front-end and in the room temperature back-end signal path. The essential properties of precision local oscillators (LOs), phase lock loops (PLLs), and LO modulation techniques are also describ...

  7. Waveform Analysis of UWB GPR Antennas

    Directory of Open Access Journals (Sweden)

    Julia Armesto

    2009-03-01

    Full Text Available Ground Penetrating Radar (GPR systems fall into the category of ultra-wideband (UWB devices. Most GPR equipment covers a frequency range between an octave and a decade by using short-time pulses. Each signal recorded by a GPR gathers a temporal log of attenuated and distorted versions of these pulses (due to the effect of the propagation medium plus possible electromagnetic interferences and noise. In order to make a good interpretation of this data and extract the most possible information during processing, a deep knowledge of the wavelet emitted by the antennas is essential. Moreover, some advanced processing techniques require specific knowledge of this signal to obtain satisfactory results. In this work, we carried out a series of tests in order to determine the source wavelet emitted by a ground-coupled antenna with a 500 MHz central frequency.

  8. Waveform Analysis of UWB GPR Antennas.

    Science.gov (United States)

    Rial, Fernando I; Lorenzo, Henrique; Pereira, Manuel; Armesto, Julia

    2009-01-01

    Ground Penetrating Radar (GPR) systems fall into the category of ultra-wideband (UWB) devices. Most GPR equipment covers a frequency range between an octave and a decade by using short-time pulses. Each signal recorded by a GPR gathers a temporal log of attenuated and distorted versions of these pulses (due to the effect of the propagation medium) plus possible electromagnetic interferences and noise. In order to make a good interpretation of this data and extract the most possible information during processing, a deep knowledge of the wavelet emitted by the antennas is essential. Moreover, some advanced processing techniques require specific knowledge of this signal to obtain satisfactory results. In this work, we carried out a series of tests in order to determine the source wavelet emitted by a ground-coupled antenna with a 500 MHz central frequency.

  9. Ultra wideband antennas design, methodologies, and performance

    CERN Document Server

    Galvan-Tejada, Giselle M; Jardón Aguilar, Hildeberto

    2015-01-01

    Ultra Wideband Antennas: Design, Methodologies, and Performance presents the current state of the art of ultra wideband (UWB) antennas, from theory specific for these radiators to guidelines for the design of omnidirectional and directional UWB antennas. Offering a comprehensive overview of the latest UWB antenna research and development, this book:Discusses the developed theory for UWB antennas in frequency and time domainsDelivers a brief exposition of numerical methods for electromagnetics oriented to antennasDescribes solid-planar equivalen

  10. Millimeter and submillimeter wave antenna structure

    Science.gov (United States)

    Rebiez, Gabriel M. (Inventor); Rutledge, David B. (Inventor)

    1989-01-01

    An integrated circuit antenna structure for transmitting or receiving millimeter and/or submillimeter wave radiation having an antenna relatively unimpaired by the antenna mounting arrangment is disclosed herein. The antenna structure of the present invention includes a horn disposed on a substrate for focusing electromagnetic energy with respect to an antenna. The antenna is suspended relative to the horn to receive or transmit the electromagnetic energy focused thereby.

  11. Microelectromechanical Systems Actuator Based Reconfigurable Printed Antenna

    Science.gov (United States)

    Simons, Rainee N. (Inventor)

    2005-01-01

    A polarization reconfigurable patch antenna is disclosed. The antenna includes a feed element, a patch antenna element electrically connected to the feed element, and at least one microelectromechanical systems (MEMS) actuator, with a partial connection to the patch antenna element along an edge of the patch antenna element. The polarization of the antenna can be switched between circular polarization and linear polarization through action of the at least one MEMS actuator.

  12. Higher-order techniques in computational electromagnetics

    CERN Document Server

    Graglia, Roberto D

    2016-01-01

    Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.

  13. Clear air boundary layer spaced antenna wind measurement with the Multiple Antenna Profiler (MAPR

    Directory of Open Access Journals (Sweden)

    S. A. Cohn

    Full Text Available Spaced antenna (SA wind measurement techniques are applied to Multiple Antenna Profiler (MAPR data to evaluate its performance in clear air conditions. MAPR is a multiple antenna 915 MHz wind profiler developed at the National Center for Atmospheric Research (NCAR and described in Cohn et al. (1997, designed to make high resolution wind measurements. Previous reported measurements with MAPR were restricted to precipitation because of low signal to noise (SNR and signal to ground-clutter (SCR ratios. By using a standard pulse-coding technique and upgrading the profiler control software, increases in average power and SNR were achieved, making routine measurements in clear air possible. Comparison of winds measured by MAPR and by a sonic anemometer on a nearby 300 m tower show correlation coefficients in the range of R2 = 0.75 – 0.80, and an average absolute error of ~ 1.4 m s - 1 . This compares favorably with the agreement typically found in wind profiler comparisons. We also consider the use of the parameter ah , which is related to the value of the cross-correlation function at its zero crossing. This parameter is a data quality indicator and possibly a key component in a ground clutter removal technique.

    Key words. Meteorology and atmospheric dynamics (mesoscale meteorology; instruments and techniques – Radio science (remote sensing

  14. Patch antenna terahertz photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Palaferri, D.; Todorov, Y., E-mail: yanko.todorov@univ-paris-diderot.fr; Chen, Y. N.; Madeo, J.; Vasanelli, A.; Sirtori, C. [Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot, Sorbonne Paris Cité, CNRS-UMS 7162, 75013 Paris (France); Li, L. H.; Davies, A. G.; Linfield, E. H. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2015-04-20

    We report on the implementation of 5 THz quantum well photodetector exploiting a patch antenna cavity array. The benefit of our plasmonic architecture on the detector performance is assessed by comparing it with detectors made using the same quantum well absorbing region, but processed into a standard 45° polished facet mesa. Our results demonstrate a clear improvement in responsivity, polarization insensitivity, and background limited performance. Peak detectivities in excess of 5 × 10{sup 12} cmHz{sup 1/2}/W have been obtained, a value comparable with that of the best cryogenic cooled bolometers.

  15. Terahertz antenna electronic chopper

    Energy Technology Data Exchange (ETDEWEB)

    Sterczewski, L. A., E-mail: lukasz.sterczewski@pwr.edu.pl; Grzelczak, M. P.; Plinski, E. F. [Department of Electronics, Wroclaw University of Technology, 27 Wybrzeze Wyspianskiego St., 50-370 Wroclaw (Poland)

    2016-01-15

    In this paper, we present an electronic circuit used to bias a photoconductive antenna that generates terahertz radiation. The working principles and the design process for the device are discussed in detail. The noise and shape of the wave measurements for a built device are considered. Furthermore, their impact on a terahertz pulse and its spectra is also examined. The proposed implementation is simple to build, robust and offers a real improvement over THz instrumentation due to the frequency tuning. Additionally, it provides for galvanic isolation and ESD protection.

  16. Ultra wide band antennas

    CERN Document Server

    Begaud, Xavier

    2013-01-01

    Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

  17. RIGOROUS FULL-WAVE ANALYSIS OF THE BASE-STATION ANTENNAS

    Institute of Scientific and Technical Information of China (English)

    Chen Shengbing; Zhang Fushun; Jiao Yongchang; Sun Baohua

    2002-01-01

    Rigorous analysis of the Base-Station (BS) antennas with reflector is made in this letter. The wire-grid modeling of BS antenna is established. In order to improve the solution accuracy and efficiency, some efficient techniques such as three-term sinusoidal interpolation basis function and discrete wavelet transform are used. Numerical examples considered here are the typical vertically polarized and the dual-polarized BS antennas. The calculated results for the vertically polarized BS antenna are in good agreement with the measured data, which show that the analysis modeling used is accurate and reliable.

  18. An improved scanning automatic tracking antenna for telemetry applications

    Science.gov (United States)

    Cook, James H., Jr.; Dishman, W. Keith

    The present comparative evaluation of the sequential lobing, conical scan, and single channel monopulse techniques for the generation of offset radar beams gives attention to the performance of a novel, generalized electronic scanned beam configuration, in view of various mission scenario requirements. The innovative 'electronic-scanning' (ESCAN) autotracking technique is elaborated mathematically, and its performance is projected in view of analytical and measured antenna radiation pattern data. The ESCAN tracking antenna concept is shown to have side-lobe characteristics superior to those of previous methods due to their control in the scanned, offset beam plane as well as the orthogonal plane.

  19. Broadband antenna with frequency scanning

    Directory of Open Access Journals (Sweden)

    A. A. Shekaturin

    2014-06-01

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

  20. The Ultrawideband Leaky Lens Antenna

    NARCIS (Netherlands)

    Bruni, S.; Neto, A.; Marliani, F.

    2007-01-01

    A novel directive and nondispersive antenna is presented: the ultrawideband (UWB) leaky lens. It is based on the broad band Cherenkov radiation occurring at a slot printed between different infinite homogeneous dielectrics. The first part of the paper presents the antenna concept and the UWB design.

  1. Absorption Efficiency of Receiving Antennas

    DEFF Research Database (Denmark)

    Andersen, Jørgen Bach; Frandsen, Aksel

    2005-01-01

    A receiving antenna with a matched load will always scatter some power. This paper sets an upper and a lower bound on the absorption efficiency (absorbed power over sum of absorbed and scattered powers), which lies between 0 and 100% depending on the directivities of the antenna and scatter...

  2. Millimeter-wave antenna measurement

    NARCIS (Netherlands)

    Akkermans, J.A.G.; Dijk, R. van; Herben, M.H.A.J.

    2007-01-01

    A novel approach is presented to accurately measure the scattering parameters as well as the radiation pattern of planar antennas that operate in the millimeter-wave frequency band. To avoid interconnection problems, RF probes have been used to connect to the antenna. These RF probes are normally us

  3. Antennas for light and plasmons

    NARCIS (Netherlands)

    Dikken, Dirk Jan Willem

    2015-01-01

    Antennas have been used for over a century as emitters, scatterers and receivers of electromagnetic waves. All wireless communication devices, such as radio, mobile phones and satellite communication are strongly dependent on the capability of an antenna to localize propagating electromagnetic waves

  4. Tunable Antennas for Mobile Devices

    DEFF Research Database (Denmark)

    Morris, Art; Barrio, Samantha Caporal Del; Shin, J

    2014-01-01

    Modern mobile terminal design has been driven by the user interface and broadband connectivity. Real world RF performance has substantially fallen recently which impacts data rates, battery life and often causes lost connections. This has been caused by changing antenna location and reduced antenna...

  5. Mobile Phone Antenna Performance 2016

    DEFF Research Database (Denmark)

    Pedersen, Gert F.

    2016-01-01

    This study investigates the antenna performance of a number of mobile phones widely used in the Nordic Countries. The study is supported by the Nordic Council of Ministers. The antenna performance of the phones is vital for the phones ability to ensure radio coverage in low signal situations...

  6. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  7. Slot-Coupled Barbel Antenna

    DEFF Research Database (Denmark)

    Jørgensen, Kasper Lüthje; Jakobsen, Kaj Bjarne

    2016-01-01

    A novel slot-coupled barbel antenna is designed and analyzed. A sensitivity analysis performed in order to improve the bandwidth, while the center frequency is kept constant.......A novel slot-coupled barbel antenna is designed and analyzed. A sensitivity analysis performed in order to improve the bandwidth, while the center frequency is kept constant....

  8. Diagnostics of Nanodusty Plasma

    Science.gov (United States)

    Greiner, Franko; Groth, Sebastian; Tadsen, Bejamin; Piel, Alexander

    2015-11-01

    The diagnostic of nanodusty plasmas, i.e. plasmas including nano-sized dust particles, is a challenging task. For both, the diagnostic of the nanodusty plasma itself, and the in-situ diagnostic of the nanoparticles, no standard diagnostic exist. Nanodust particle size and density can be estimated using light scattering techniques, namely kinetic Mie ellipsometry and extinction measurements. The charge of the nanoparticles can be estimated from the analysis of dust density waves (DDW). Parameters like the electron density, which give information about the plasma itself, may be deduced from the DDW analysis. We present detailed investigations on nanodust in a reactive Argon-Acetylene plasma created in an rf-driven parallel plate reactor at low pressure using the above mentioned portfolio of diagnostic. Funded by DFG under contract SFB TR-24/A2.

  9. Design of Short-Circuited Microstrip Antenna Using Differential Evolution Algorithm

    Directory of Open Access Journals (Sweden)

    Arindam Deb

    2012-08-01

    Full Text Available Differential evolution (DE algorithm is used to design a microstrip antenna, loaded with a shorting pin. The position of probe and the position of shorting pin are optimized using DE. The fitness function for DE is obtained using multiport network modelling technique. Antenna is fabricated and measured results are compared with the theoretical results.

  10. Isolation Improvement of a Microstrip Patch Array Antenna for WCDMA Indoor Repeater Applications

    Directory of Open Access Journals (Sweden)

    Hongmin Lee

    2012-01-01

    Full Text Available This paper presents the isolation improvement techniques of a microstrip patch array antenna for the indoor wideband code division multiple access (WCDMA repeater applications. One approach is to construct the single-feed switchable feed network structure with an MS/NRI coupled-line coupler in order to reduce the mutual coupling level between antennas. Another approach is to insert the soft surface unit cells near the edges of the microstrip patch elements in order to reduce backward radiation waves. In order to further improve the isolation level, the server antenna and donor antenna are installedinorthogonal direction. The fabricated antenna exhibits a gain over 7 dBi and higher isolation level between server and donor antennas below −70 dB at WCDMA band.

  11. On diversity performance of two-element coupling element based antenna structure for mobile terminal

    DEFF Research Database (Denmark)

    Al-Hadi, Azremi Abdullah; Toivanen, Juha; Laitinen, Tommi;

    2010-01-01

    In wireless communication systems, multipath interference has a significant impact on system design and performance. Fast fading is caused by the coherent summation of one or more echoes from many reflection points reaching the receive antenna. Antenna diversity can be used to mitigate multipath...... fading. The main challenge of antenna diversity in practical application is the integration of multiple antennas on a small ground plane. Two-element antenna structure based on coupling element antenna concept for diversity application has been studied in previous work and it has shown to be feasible...... of efficiencies, envelope correlation, and apparent and effective diversity gains in isotropic (i.e. statistically uniform) propagation channel, using spherical near-field technique in an ideal line-of-sight environment (anechoic chamber) and inside reverberation chamber. The envelope correlation is less than 0...

  12. A wideband textile antenna with a ring-slotted AMC plane

    Science.gov (United States)

    Hussin, Ezzaty Faridah Nor Mohd; Soh, Ping Jack; Jamlos, Mohd Faizal; Lago, Herwansyah; Al-Hadi, Azremi Abdullah; Rahiman, Mohd Hafiz Fazalul

    2017-01-01

    A wideband microstrip-based textile planar antenna with artificial magnetic conductor (AMC) plane is presented. The antenna is initially designed using the combination of two rectangular microstrip antennas operating at 1.5 and 2.5 GHz before being further optimized for wideband operation using various broadbanding techniques. This optimized radiator is then placed over an array of unit elements forming an AMC plane. Each unit element is formed using a square patch slotted using a circular ring and is designed to resonate at 2 GHz. To validate the contribution of the AMC plane in reducing backward radiation toward the human user, the performance of the proposed antenna is compared to a similar antenna without the AMC plane. This investigation indicated that the proposed antenna is capable of reducing backlobe while simultaneously increasing gain to 3.38 dB and improving bandwidth up to 52%.

  13. Effects of Reentry Plasma Sheath on GPS Patch Antenna Polarization Property

    Directory of Open Access Journals (Sweden)

    L. Zhao

    2013-01-01

    Full Text Available A plasma sheath enveloping a reentry vehicle would affect performances of on-board antenna greatly, especially the navigation antennas. This paper studies the effects of reentry plasma sheath on a GPS right-hand circularly polarized (RHCP patch antenna polarization property during a typical reentry process. Utilizing the algorithm of finite integration technique, the polarization characteristic of a GPS antenna coated by a plasma sheath is obtained. Results show that the GPS RHCP patch antenna radiation pattern distortions as well as polarization deteriorations exist during the entire reentry process, and the worst polarization mismatch loss between a GPS antenna and RHCP GPS signal is nearly 3 dB. This paper also indicates that measures should be taken to alleviate the plasma sheath for maintaining the GPS communication during the reentry process.

  14. An L-strip fed stacked patch antenna for maritime satellite communications

    Institute of Scientific and Technical Information of China (English)

    FU Shi-qiang; FANG Shao-jun

    2008-01-01

    A practical antenna has been designed and developed for INMARSAT mobile satellite communications. The design uses low cost materials such as foam and copper foil to create a stacked microstrip antenna array. Several techniques were adopted to enhance the impedance bandwidth and axial ratio bandwidth. The final design parameters were optimized by EM simulation. Finally, the L-strip fed six-element stacked microstrip antenna array was constructed and tested. Simulated and measured results show that in the whole INMARSAT work band, the VSWR of the antenna is less than 1.6, its antenna gain is higher than 15riB and wide-angle axial ratio (AR) 3dB is more than 21°. The antenna has been successfully used with a HNS 9201 terminal.

  15. A comparative study of the PIFA and printed monopole antenna EM absorption.

    Science.gov (United States)

    Hossain, Md Ikbal; Iqbal Faruque, Mohammad Rashed; Islam, Mohammad Tariqul

    2017-02-01

    This paper represents a comparative study on electromagnetic (EM) absorption in the human head between a printed monopole antenna and a planar inverted-F antenna (PIFA). The specific absorption rate (SAR) values and total absorbed power in the human head phantom are used to evaluate EM absorption for both antennae. Moreover, antenna performances in terms of return loss, radiation efficiency, and gain are also investigated in this study. The finite integration technique (FIT) based on CST Microwave studio and SAM head phantom are used in this study. The antenna performances are measured in an anechoic chamber and the SAR is tested using COMOSAR measurement system. The obtained results indicate that the printed monopole antenna lead to higher EM absorption in the human head as compared to PIFA for both GSM frequencies.

  16. Novel Design of A Compact Proximity Coupled Fed Antenna

    Directory of Open Access Journals (Sweden)

    Mahdi Ali

    2012-01-01

    Full Text Available Certain applications such as RFID, on body sensors network, microwave systems usually require good matching impedance, high gain and large bandwidth for their antennas. The aperture coupled antenna is one candidate that can provide high gain large bandwidth and little packaging. Thus, it would be of interest to enhance the characteristics of a singly-fed aperture antenna used for Zigbee application. In this paper, we are presenting a new design of aperture coupled rectangular patch antenna operating at 2.45 GHz ISM-band frequency. The objective of this design is not limited to the improvement of the impedance bandwidth but also to better the coupling involved. The cross-polarisation (X-pol, the backward radiation and the half-power beam width in two orthogonal planes are also examined. The proposed design is based on a new aperture coupling technique in which two slots are fed by a microstrip line and coupled to a parasitic patch radiator etched on the opposite side from the slots. The matching impedance for a conventional aperture coupled microstrip antenna is obtained by the adjustment of the dimension of the slot and the feeding line. Here, the distance separating the slots is employed to control the coupling and modifying the input impedance of the antenna. Therefore, accurate matching impedance is reached with a good radiation pattern.

  17. Optical antennas as nanoscale resonators.

    Science.gov (United States)

    Agio, Mario

    2012-02-07

    Recent progress in nanotechnology has enabled us to fabricate sub-wavelength architectures that function as antennas for improving the exchange of optical energy with nanoscale matter. We describe the main features of optical antennas for enhancing quantum emitters and review the designs that increase the spontaneous emission rate by orders of magnitude from the ultraviolet up to the near-infrared spectral range. To further explore how optical antennas may lead to unprecedented regimes of light-matter interactions, we draw a relationship between metal nanoparticles, radio-wave antennas and optical resonators. Our analysis points out how optical antennas may function as nanoscale resonators and how these may offer unique opportunities with respect to state-of-the-art microcavities.

  18. Minimum Q Electrically Small Antennas

    DEFF Research Database (Denmark)

    Kim, O. S.

    2012-01-01

    Theoretically, the minimum radiation quality factor Q of an isolated resonance can be achieved in a spherical electrically small antenna by combining TM1m and TE1m spherical modes, provided that the stored energy in the antenna spherical volume is totally suppressed. Using closed-form expressions...... for the stored energies obtained through the vector spherical wave theory, it is shown that a magnetic-coated metal core reduces the internal stored energy of both TM1m and TE1m modes simultaneously, so that a self-resonant antenna with the Q approaching the fundamental minimum is created. Numerical results...... for a multiarm spherical helix antenna confirm the theoretical predictions. For example, a 4-arm spherical helix antenna with a magnetic-coated perfectly electrically conducting core (ka=0.254) exhibits the Q of 0.66 times the Chu lower bound, or 1.25 times the minimum Q....

  19. Optical antennas as nanoscale resonators

    CERN Document Server

    Agio, Mario

    2011-01-01

    Recent progress in nanotechnology has enabled us to fabricate subwavelength architectures that function as antennas for improving the exchange of optical energy with nanoscale matter. We describe the main features of optical antennas for enhancing quantum emitters and review designs that increase the spontaneous emission rate by orders of magnitude from the ultraviolet up to the near-infrared spectral range. To further explore how optical antennas may lead to unprecedented regimes of light-matter interaction, we draw a relationship between metal nanoparticles, radio-wave antennas and optical resonators. Our analysis points out how optical antennas may function as nanoscale resonators and how these may offer unique opportunities with respect to state-of-the-art microcavities.

  20. Numerical Modelling of Ground Penetrating Radar Antennas

    Science.gov (United States)

    Giannakis, Iraklis; Giannopoulos, Antonios; Pajewski, Lara

    2014-05-01

    Numerical methods are needed in order to solve Maxwell's equations in complicated and realistic problems. Over the years a number of numerical methods have been developed to do so. Amongst them the most popular are the finite element, finite difference implicit techniques, frequency domain solution of Helmontz equation, the method of moments, transmission line matrix method. However, the finite-difference time-domain method (FDTD) is considered to be one of the most attractive choice basically because of its simplicity, speed and accuracy. FDTD first introduced in 1966 by Kane Yee. Since then, FDTD has been established and developed to be a very rigorous and well defined numerical method for solving Maxwell's equations. The order characteristics, accuracy and limitations are rigorously and mathematically defined. This makes FDTD reliable and easy to use. Numerical modelling of Ground Penetrating Radar (GPR) is a very useful tool which can be used in order to give us insight into the scattering mechanisms and can also be used as an alternative approach to aid data interpretation. Numerical modelling has been used in a wide range of GPR applications including archeology, geophysics, forensic, landmine detection etc. In engineering, some applications of numerical modelling include the estimation of the effectiveness of GPR to detect voids in bridges, to detect metal bars in concrete, to estimate shielding effectiveness etc. The main challenges in numerical modelling of GPR for engineering applications are A) the implementation of the dielectric properties of the media (soils, concrete etc.) in a realistic way, B) the implementation of the geometry of the media (soils inhomogeneities, rough surface, vegetation, concrete features like fractures and rock fragments etc.) and C) the detailed modelling of the antenna units. The main focus of this work (which is part of the COST Action TU1208) is the accurate and realistic implementation of GPR antenna units into the FDTD

  1. On-Wafer Characterization of Millimeter-Wave Antennas for Wireless Applications

    Science.gov (United States)

    Simons, Rainee N.; Lee, Richard Q.

    1998-01-01

    The paper demonstrates a de-embedding technique and a direct on-substrate measurement technique for fast and inexpensive characterization of miniature antennas for wireless applications at millimeter-wave frequencies. The technique is demonstrated by measurements on a tapered slot antenna (TSA). The measured results at Ka-Band frequencies include input impedance, mutual coupling between two TSAs and absolute gain of TSA.

  2. Detecting flaws in Portland cement concrete using TEM horn antennae

    Science.gov (United States)

    Al-Qadi, Imad L.; Riad, Sedki M.; Su, Wansheng; Haddad, Rami H.

    1996-11-01

    To understand the dielectric properties of PCC and better correlate them with type and severity of PCC internal defects, a study was conducted to evaluate PCC complex permittivity and magnetic permeability over a wideband of frequencies using both time domain and frequency domain techniques. Three measuring devices were designed and fabricated: a parallel plate capacitor, a coaxial transmission line, and transverse electromagnetic (TEM) horn antennae. The TEM horn antenna covers the microwave frequencies. The measurement technique involves a time domain setup that was verified by a frequency domain measurement. Portland cement concrete slabs, 60 by 75 by 14 cm, were cast; defects include delamination, delamination filled with water, segregation, and chloride contamination. In this paper, measurements using the TEM horn antennae and the feasibility of detecting flaws at microwave frequency are presented.

  3. Analysis and design of low profile multiband multifunctional antenna arrays

    Science.gov (United States)

    Hunsicker, Walker F.

    Light-weight phased array antennas for aerospace and mobile applications require utilizing the same antenna aperture to provide multiple functions with dissimilar radiation pattern specifications (e.g., multiband operation for communications and tracking). Multi-functional antennas provide advantages over aggregate antenna clusters by reducing space requirements, and can aid in the optimal placement of all required apertures to provide adequate isolation between channels. Furthermore, the combination of antenna apertures into a common geometry mitigates co-site installation issues by addressing interference within the integrated radiator design itself as opposed to the extensive analysis which is required to configure multiple radiators in close proximity. The combination of multiple radiators into a single aperture can only be achieved with the proper selection of antenna topology and accompanying feed network design. This research proposes a new technique for the design of multiband arrays in which a common aperture is used. Highlighted by this method is the integration of a tri-band array comprised of an X-band (12 GHz) microstrip patch array on a superstrate above printed dual-band (1 and 2 GHz) slot loop antenna arrays in an octave-spaced lattice. The selection of a ground backing reflector is considered for improved gain and system packaging, but restricts the utility of the design principally due to the lambda/4 depth of the ground plane. Therefore, a novel multiband high impedance surfaces (HIS) is proposed to load the slot apertures for reduced height. The novel techniques proposed here will enable the design of a low profile and conformal single aperture supporting multi-band and multi-functional operations.

  4. Tissue dielectric measurement using an interstitial dipole antenna.

    Science.gov (United States)

    Wang, Peng; Brace, Christopher L

    2012-01-01

    The purpose of this study was to develop a technique to measure the dielectric properties of biological tissues with an interstitial dipole antenna based upon previous efforts for open-ended coaxial probes. The primary motivation for this technique is to facilitate treatment monitoring during microwave tumor ablation by utilizing the heating antenna without additional intervention or interruption of the treatment. The complex permittivity of a tissue volume surrounding the antenna was calculated from reflection coefficients measured after high-temperature microwave heating by using a rational function model of the antenna's input admittance. Three referencing liquids were needed for measurement calibration. The dielectric measurement technique was validated ex vivo in normal and ablated bovine livers. Relative permittivity and effective conductivity were lower in the ablation zone when compared to normal tissue, consistent with previous results. The dipole technique demonstrated a mean 10% difference of permittivity values when compared to open-ended coaxial cable measurements in the frequency range of 0.5-20 GHz. Variability in measured permittivities could be smoothed by fitting to a Cole-Cole dispersion model. Further development of this technique may facilitate real-time monitoring of microwave ablation treatments through the treatment applicator.

  5. Microstrip antenna on tunable substrate

    Science.gov (United States)

    Jose, K. A.; Varadan, Vijay K.; Varadan, Vasundara V.; Mohanan, P.

    1995-05-01

    The tunable patch antenna configurations are becoming popular and attractive in many aspects. This was mainly due to the advent of ferrite thin film technology and tunable substrate materials. The integration of monolithic microwave circuits and antennas are becoming easy today. In the development of magnetic tuning of microstrip patch on ferrite substrate is presented by Rainville and Harackewiez. Radiation characteristics of such antennas are presented by Pozer. Band width and radiation characteristics of such tunable antennas are measured and compared. Usually the substrate losses are considered in the analysis and metallization losses are assumed to be ideal. The analysis of magnetic tunable radiator including metallization and ferrite substrate losses are presented. However, all such tuning and integration of circuits and antennas are mainly on ferrite substrate due to magnetic tuning. Recently, Varadan et al. established that the BaxSr1-xTiO3 series ferroelectric materials such as Barium Strontium Titanate (BST) are well suited for microwave phase shifter applications. It could be possible to change the dielectric constant of these materials more than 50% depending on the BST composition, by changing the applied bias voltage. Also, the porosity of BST can be controlled during processing to produce dielectric constants in the range of 15 to 1500, with some trade off in tunability. In this paper, we are presenting the possibility of designing a microstrip patch antenna on such tunable substrate. Such antennas are having the major advantage of electronic tunability and compact size.

  6. 47 CFR 95.1213 - Antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antennas. 95.1213 Section 95.1213... SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1213 Antennas. No antenna for a MedRadio transmitter shall be configured for permanent outdoor use. In addition, any MedRadio antenna used...

  7. Thermal Loss in High-Q Antennas

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Bahramzy, Pevand; Svendsen, Simon

    2014-01-01

    Tunable antennas are very promising for future generations of mobile communications, where antennas are required to cover a wide range operating bands. This letter aims at characterizing the loss mechanism of tunable antennas. Tunable antennas typically exhibit a high Quality factor (Q), which can...

  8. 47 CFR 95.1013 - Antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antennas. 95.1013 Section 95.1013... SERVICES Low Power Radio Service (LPRS) General Provisions § 95.1013 Antennas. (a) The maximum allowable... this chapter, at the band edges. (b) AMTS stations must employ directional antennas. (c) Antennas...

  9. 47 CFR 73.1675 - Auxiliary antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Auxiliary antennas. 73.1675 Section 73.1675... Rules Applicable to All Broadcast Stations § 73.1675 Auxiliary antennas. (a)(1) An auxiliary antenna is one that is permanently installed and available for use when the main antenna is out of service...

  10. Double Structure Broadband Leaky Wave Antenna

    NARCIS (Netherlands)

    Neto, A.; Dijk, R. van; Filippo, M.

    2011-01-01

    A leaky wave antenna contains a first and a second leaky wave antenna structure back to back against each other. Each antenna structure comprises a dielectric body and an elongated wave carrying structure, such as a slot in a conductive ground plane. In each leaky wave antenna structure the body and

  11. Metamaterial antennas: the most successful metamaterial technology?

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2015-01-01

    The Thomson Reuters Web of Science™ lists more than 1500 journal articles related to metamaterial antennas from 2001 to 2015; this paper overviews some major objectives of such antennas.......The Thomson Reuters Web of Science™ lists more than 1500 journal articles related to metamaterial antennas from 2001 to 2015; this paper overviews some major objectives of such antennas....

  12. 47 CFR 73.753 - Antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna systems. 73.753 Section 73.753... International Broadcast Stations § 73.753 Antenna systems. All international broadcasting stations shall operate with directional antennas. Such antennas shall be designed and operated so that the radiated power...

  13. 47 CFR 73.69 - Antenna monitors.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna monitors. 73.69 Section 73.69... Broadcast Stations § 73.69 Antenna monitors. (a) Each station using a directional antenna must have in operation at the transmitter site an FCC authorized antenna monitor. (b) In the event that the...

  14. 47 CFR 95.51 - Antenna height.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna height. 95.51 Section 95.51... SERVICES General Mobile Radio Service (GMRS) § 95.51 Antenna height. (a) Certain antenna structures used in... this chapter. (b) The antenna for a small base station or for a small control station must not be...

  15. 47 CFR 73.510 - Antenna systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna systems. 73.510 Section 73.510... Noncommercial Educational FM Broadcast Stations § 73.510 Antenna systems. (a) All noncommercial educational... § 73.316 concerning antenna systems contained in subpart B of this part. (b) Directional antenna....

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

    Directory of Open Access Journals (Sweden)

    MARWAHA S.

    2012-08-01

    Full Text Available 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 imaging techniques and surgical robots. The authors investigated the microwave coaxial antenna operating at 2.45 GHz by varying the slots size for the removal of liver tumor. The analysis was done using 2D finite element modeling. By several optimization steps the antenna is simulated and optimized by comparing the values of specific absorption rate (SAR, mesh statistics and temperature distributions in tissue generated by the antenna with the variations of dimensions of slot from 1 mm to 1.7 mm.

  17. Photocurrent mapping of near-field optical antenna resonances

    KAUST Repository

    Barnard, Edward S.

    2011-08-21

    An increasing number of photonics applications make use of nanoscale optical antennas that exhibit a strong, resonant interaction with photons of a specific frequency. The resonant properties of such antennas are conventionally characterized by far-field light-scattering techniques. However, many applications require quantitative knowledge of the near-field behaviour, and existing local field measurement techniques provide only relative, rather than absolute, data. Here, we demonstrate a photodetector platform that uses a silicon-on-insulator substrate to spectrally and spatially map the absolute values of enhanced fields near any type of optical antenna by transducing local electric fields into photocurrent. We are able to quantify the resonant optical and materials properties of nanoscale (∼50nm) and wavelength-scale (∼1μm) metallic antennas as well as high-refractive-index semiconductor antennas. The data agree well with light-scattering measurements, full-field simulations and intuitive resonator models. © 2011 Macmillan Publishers Limited. All rights reserved.

  18. Pentagonal shaped microstrip patch antenna in wireless capsule endoscopy system

    Directory of Open Access Journals (Sweden)

    Bondili Kohitha Bai

    2012-01-01

    Full Text Available Wireless capsule endoscopy is a best option for exploring inaccessible areas of small intestine for inspection of gastrointestinal tract. This technique brings less pain compare to conventional endoscopy technique. The wireless endoscopy system comprises of three main modules: an ingestible capsule that is swallowed by the patient, an external control unit and display device for image display. In this paper we proposed pentagonal shape microstrip patch antenna for wireless capsule endoscopy system. Inhibiting characteristics of a single microstrip patch like low gain, light weight, thin thickness and smaller bandwidth, make it more popular. This kind of antenna is aggressive miniaturized to meet the requirements of the wireless capsule endoscope. The simulation results show that the designed Circular Polarization (CP pentagonal shaped microstrip patch antenna gives axial ratio of 0.6023 at 2.38 GHz and CP axial ratio bandwidth of 36MHz with 1.5%. The antenna designed for wireless capsule endoscopy is a proposed one, which may work effectively when compared to other antennas in the capsule.

  19. Metal Patch Antenna

    Science.gov (United States)

    Chamberlain, Neil F. (Inventor); Hodges, Richard E. (Inventor); Zawadzki, Mark S. (Inventor)

    2012-01-01

    Disclosed herein is a patch antenna comprises a planar conductive patch attached to a ground plane by a support member, and a probe connector in electrical communication with the conductive patch arranged to conduct electromagnetic energy to or from the conductive patch, wherein the conductive patch is disposed essentially parallel to the ground plane and is separated from the ground plane by a spacing distance; wherein the support member comprises a plurality of sides disposed about a central axis oriented perpendicular to the conductive patch and the ground plane; wherein the conductive patch is solely supported above the ground plane by the support member; and wherein the support member provides electrical communication between the planer conductive patch and the ground plane.

  20. Group Delay of High Q Antennas

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert Frølund

    2013-01-01

    become an issue, when working with high Q antennas, because of the steep phase shift over the frequency. In this paper, it is measured how large group delay variations can become, when going from a low Q antenna to a high Q antenna. The group delay of a low Q antenna is shown to be around 1.3 ns, whereas...... a high Q antenna has group delay of around 22 ns. It is due to this huge group delay variation characteristics of high Q antennas, that signal distortion might occur in the radio system with high Q antennas....

  1. Direction of Arrival Estimation with a Novel Single-Port Smart Antenna

    Directory of Open Access Journals (Sweden)

    Chen Sun

    2004-08-01

    Full Text Available A novel direction of arrival (DOA estimation technique that uses the conventional multiple-signal classification (MUSIC algorithm with periodic signals is applied to a single-port smart antenna. Results show that the proposed method gives a high-resolution (1 degree DOA estimation in an uncorrelated signal environment. The novelty lies in that the MUSIC algorithm is applied to a simplified antenna configuration. Only 1 analogue-to-digital converter (ADC is used in this antenna, which features low power consumption, low cost, and ease of fabrication. Modifications to the conventional MUSIC algorithm do not bring much additional complexity. The proposed technique is also free from the negative influence by the mutual coupling among antenna elements. Therefore, it offers an economical way to extensively implement smart antennas into the existing wireless mobile communications systems, especially at the power consumption limited mobile terminals such as laptops in wireless networks.

  2. Direction of Arrival Estimation with a Novel Single-Port Smart Antenna

    Science.gov (United States)

    Sun, Chen; Karmakar, Nemai C.

    2004-12-01

    A novel direction of arrival (DOA) estimation technique that uses the conventional multiple-signal classification (MUSIC) algorithm with periodic signals is applied to a single-port smart antenna. Results show that the proposed method gives a high-resolution (1 degree) DOA estimation in an uncorrelated signal environment. The novelty lies in that the MUSIC algorithm is applied to a simplified antenna configuration. Only 1 analogue-to-digital converter (ADC) is used in this antenna, which features low power consumption, low cost, and ease of fabrication. Modifications to the conventional MUSIC algorithm do not bring much additional complexity. The proposed technique is also free from the negative influence by the mutual coupling among antenna elements. Therefore, it offers an economical way to extensively implement smart antennas into the existing wireless mobile communications systems, especially at the power consumption limited mobile terminals such as laptops in wireless networks.

  3. Single and dual-Gregorian reflector antenna shaped beam far-field synthesis

    Science.gov (United States)

    Mehler, M. J.

    The direct far-field G.O. synthesis of shaped beam reflector antennas has recently been treated by Mehler, Tun and Adatia (1986). These authors use a synthesis technique which exploits complex coordinates and which is based on a method originally considered by Norris and Westcott (1976). They describe the synthesis of single reflector antennas which radiate both elliptical beams and European coverage patterns. Here this technique is extended to consider a class of dual reflector antennas which possess shaped main reflectors and conic subreflectors. An example is given of a Gregorian duel reflector antenna which radiates a cross-polar field significantly smaller than that radiated by single shaped reflector antennas. In addition, the behavior of the radiation pattern as a function of the reflector diameter is investigated.

  4. DUAL BAND MONOPOLE ANTENNA DESIGN

    Directory of Open Access Journals (Sweden)

    P. Jithu

    2013-06-01

    Full Text Available The WLAN and Bluetooth applications become popular in mobile devices, integrating GSM and ISM bands operation in one compact antenna, can reduce the size of mobile devices. Recently, lot many investigations are carried out in designing a dual band antennas with operating frequencies in GSM band and in ISM band for mobile devices. Printed monopoles are under this investigation. In this paper, dual-band printed monopoles are presented to operate at GSM band i.e. 900 MHz and ISM band i.e. 2.4 GHz. We intend to observe the antenna characteristics on the network analyzer and verify the theoretical results with the practical ones.

  5. The collinear coaxial array antenna

    Science.gov (United States)

    Brammer, D. J.; Williams, D.

    1981-03-01

    A design of a coaxial vertical antenna proposed in the ARRL antenna handbook is analyzed. A numerical analysis was carried out using the moment method. A variety of antenna configurations in the 160 MHz design frequency are analyzed and current distribution, gain, polar diagrams and impedances are calculated. The analysis is carried out for simple configurations and extended to a case with 16 repeated center sections. The effects of using lossy cable in the construction is also investigated. A defect in the original ARRL design is rectified. An array of an overall length 5.33 wavelengths is shown to have a gain of 10.69 dB.

  6. Microstrip and printed antenna design

    CERN Document Server

    Bancroft, Randy

    2009-01-01

    The approach in this book is historical and practical. It covers abasic designsa in more detail than other microstrip antenna books that tend to skip important electrical properties and implementation aspects of these types of antennas. Examples include: quarter-wave patch, quarter by quarter patch, detailed design method for rectangular circularly polarized patch, the use of the TM11 (linear and broadside CP), TM21 (monopole CP pattern) and TM02 (monopole linear) circular patch modes in designs, dual-band antenna designs which allow for independent dual-band frequencies. Limits on broadband m

  7. Analysis of radome-enclosed antennas

    CERN Document Server

    Kozakoff, Dennis J

    2009-01-01

    This title provides a current, comprehensive overview of the design and analysis of radomes. The second edition includes a wealth of new material, including three new chapters on radome measurement techniques, environmental effects on radomes, and new radome technology. This unique book helps you to design radomes for top performance, understand the effect a radome has on a particular antenna's operation, and become knowledgeable about how to specify acceptable radome equipment. Over 130 illustrations and more than 250 equations support key topics throughout the book.

  8. [Molecular diagnostics and imaging].

    Science.gov (United States)

    Fink, Christian; Fisseler-Eckhoff, Annette; Huss, Ralf; Nestle, Ursula

    2009-01-01

    Molecular diagnostic methods and biological imaging techniques can make a major contribution to tailoring patients' treatment needs with regard to medical, ethical and pharmaco-economic aspects. Modern diagnostic methods are already being used to help identify different sub-groups of patients with thoracic tumours who are most likely to benefit significantly from a particular type of treatment. This contribution looks at the most recent developments that have been made in the field of thoracic tumour diagnosis and analyses the pros and cons of new molecular and other imaging techniques in day-to-day clinical practice.

  9. Molecular diagnostic technique in the diagnosis of cardiovascular disease:application and challenge%分子诊断技术在心血管疾病诊疗中的应用与挑战

    Institute of Scientific and Technical Information of China (English)

    黄山; 张春阳

    2015-01-01

    Application ofmolecular diagnostic technique has shown greatpotential and technical advantages in the diagnosis and treatment of cardiovascular disease ( CVD ) .It can be used toscreening , diagnosis , treatment and prognostic evaluation of CVD disease .Early screening helps to notice the risk of the disease, make us take appropriate measures to reduce the health care costs and improve outcomes .To achieve the highest diagnostic efficiency by applying different molecular diagnostic strategies in different diseases.In term of treatment, molecular diagnostic technologies are mainly used in the drug discovery , personalized drug therapy and treatment options; In addition, prognostic assessment of CVD is also an important development direction of molecular diagnostic technique .However, there are severe challenges remained in applying molecular diagnostic techniques in CVD disease , such as the basic andclinicalapplication research and the quality control , etc.%分子诊断技术在心血管疾病诊疗上的应用,已经显示了巨大的潜力和技术优势,可用于心血管疾病的筛查、诊断、治疗和预后评价。筛查有助于预告疾病风险、提早采取相应措施降低医疗成本和改善预后;对不同的疾病采用不同的分子诊断策略,可以达到最佳的诊断效能;分子诊断技术在治疗方面主要应用于新药研发、个性化药物治疗和治疗方案选择;对心血管疾病进行预后评估也是分子诊断技术的重要发展方向。分子诊断技术在心血管疾病的基础和临床应用研究、质量管理等方面,也存在着严峻的挑战。(中华检验医学杂志,2015,38:433-435)

  10. Far-field pattern analysis of extended-hemispherical-lens/objective-lens antenna system at millimeter wavelengths

    Science.gov (United States)

    Dou, Wenbin; Sun, Zhong Liang; Zeng, G.

    1998-11-01

    integrated antennas have the advantages of low cost and can be readily mass produced using standard IC fabrication processes. However, integrated antennas suffer from the surface wave effect at millimeter waves. One of the ways to avoid this problem is to integrate the antennas on a dielectric lens. This structure does not support surface-waves and tend to radiate most of their power into the dielectric side making the pattern unidirectional on high dielectric constant lenses. The dielectric lens also provides mechanical rigidity and thermal stability. There are various dielectric lenses which can be used for receiver application. Among them the extended hemispherical lens is very practical, since it can synthesize other lenses such as hemispherical, hyperhemispherical, or ellipsoidal simply by varying the extension length behind the hemispherical position. In reference five, investigation on such antenna/lens system is presented. In reference 6, slot- ring antennas on dielectric lens is investigated. In many applications the extended hemispherical lens/objective lens antenna system is more attractive, because it can provide higher gain and may be used in imaging system. On the other hand, monopulse direction-finding techniques are currently the most accurate and rapid method for locating a target electronically. This antenna system can also be used as monopulse antenna. However, the treatments on such antenna system are not presented yet. In this paper, the radiation pattern of the antenna system fed by double-slot antenna are computed using ray-tracing and diffraction integration methods. Although the double-slot antenna is used as feed antenna, other antenna such as slot-ring, bow-tie antenna can be used too.

  11. Wideband Antennas for Modern Radar Systems

    OpenAIRE

    Ren, Yu-Jiun; Lai, Chieh-Ping

    2010-01-01

    In this chapter, the basics of the antenna and phased array are reviewed and different wideband antennas for modern radar systems are presented. The concepts of the radome and frequency selective surface are also reviewed. The main contents include important parameters of the antenna, and theory and design consideration of the array antenna. Various wideband antennas are introduced and their performances are demonstrated, including: (1) for the phased array radar, the slotted waveguide array ...

  12. Electrically floating, near vertical incidence, skywave antenna

    Science.gov (United States)

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  13. Smart Coat with a Fully-Embedded Textile Antenna for IoT Applications

    Science.gov (United States)

    Loss, Caroline; Gonçalves, Ricardo; Lopes, Catarina; Pinho, Pedro; Salvado, Rita

    2016-01-01

    The Internet of Things (IoT) scenario is strongly related with the advance of the development of wireless sensor networks (WSN) and radio frequency identification (RFID) systems. Additionally, in the WSN context, for a continuous feed, the integration of textile antennas for energy harvesting into smart clothing is a particularly interesting solution when the replacement of batteries is not easy to practice, such as in wearable devices. This paper presents the E-Caption: Smart and Sustainable Coat. It has an embedded dual-band textile antenna for electromagnetic energy harvesting, operating at global system for mobile communication (GSM) 900 and digital cellular system (DCS) 1800 bands. This printed antenna is fully integrated, as its dielectric is the textile material composing the coat itself. The E-Caption illustrates the innovative concept of textile antennas that can be manipulated as simple emblems. Seven prototypes of these “emblem” antennas, manufactured by lamination and embroidering techniques are also presented. It is shown that the orientation of the conductive fabric does not influence the performance of the antenna. It is also shown that the direction and number of the stitches in the embroidery may influence the performance of the antenna. Moreover, the comparison of results obtained before and after the integration of the antenna into cloth shows the integration does not affect the behavior of the antenna. PMID:27338407

  14. Smart Coat with a Fully-Embedded Textile Antenna for IoT Applications.

    Science.gov (United States)

    Loss, Caroline; Gonçalves, Ricardo; Lopes, Catarina; Pinho, Pedro; Salvado, Rita

    2016-06-22

    The Internet of Things (IoT) scenario is strongly related with the advance of the development of wireless sensor networks (WSN) and radio frequency identification (RFID) systems. Additionally, in the WSN context, for a continuous feed, the integration of textile antennas for energy harvesting into smart clothing is a particularly interesting solution when the replacement of batteries is not easy to practice, such as in wearable devices. This paper presents the E-Caption: Smart and Sustainable Coat. It has an embedded dual-band textile antenna for electromagnetic energy harvesting, operating at global system for mobile communication (GSM) 900 and digital cellular system (DCS) 1800 bands. This printed antenna is fully integrated, as its dielectric is the textile material composing the coat itself. The E-Caption illustrates the innovative concept of textile antennas that can be manipulated as simple emblems. Seven prototypes of these "emblem" antennas, manufactured by lamination and embroidering techniques are also presented. It is shown that the orientation of the conductive fabric does not influence the performance of the antenna. It is also shown that the direction and number of the stitches in the embroidery may influence the performance of the antenna. Moreover, the comparison of results obtained before and after the integration of the antenna into cloth shows the integration does not affect the behavior of the antenna.

  15. A Reconfigurable WiMAX Antenna for Directional and Broadside Application

    Directory of Open Access Journals (Sweden)

    M. Jusoh

    2013-01-01

    Full Text Available A novel reconfigurable compact patch array antenna for directional and broadside application is proposed. The presented antenna has successfully been able to function for directional beam at 320° or 35° and divisive broadside beam at 43° and 330°. This is realized in the unique form of aperture coupled spiral feeding technique and positioning of the radiating elements at 0°, 90,° and 180°. The switchable feature is effectively performed by the configuration of three PIN diodes. All PIN diodes are positioned at the specific location of the aperture coupled structure. It is discovered in simulation that the switches can be represented with a copper strip line or touchstone (TS block . The proposed antenna design operates at 2.37 GHz to 2.41 GHz and has a maximum gain of 6.4 dB and efficiency of 85.97%. Such antenna produces a broadside HPBW with a wider bandwidth covering from −90° to 90° compared to the normal microstrip antenna which could only provide HPBW of −50° to 50°. Moreover, the proposed antenna has small physical dimension of 100 mm by 100 mm. The simulation and measurement results have successfully exhibited the idea of the presented antenna performance. Therefore, the antenna is sufficiently competent in the smart WiMAX antenna application.

  16. Smart Coat with a Fully-Embedded Textile Antenna for IoT Applications

    Directory of Open Access Journals (Sweden)

    Caroline Loss

    2016-06-01

    Full Text Available The Internet of Things (IoT scenario is strongly related with the advance of the development of wireless sensor networks (WSN and radio frequency identification (RFID systems. Additionally, in the WSN context, for a continuous feed, the integration of textile antennas for energy harvesting into smart clothing is a particularly interesting solution when the replacement of batteries is not easy to practice, such as in wearable devices. This paper presents the E-Caption: Smart and Sustainable Coat. It has an embedded dual-band textile antenna for electromagnetic energy harvesting, operating at global system for mobile communication (GSM 900 and digital cellular system (DCS 1800 bands. This printed antenna is fully integrated, as its dielectric is the textile material composing the coat itself. The E-Caption illustrates the innovative concept of textile antennas that can be manipulated as simple emblems. Seven prototypes of these “emblem” antennas, manufactured by lamination and embroidering techniques are also presented. It is shown that the orientation of the conductive fabric does not influence the performance of the antenna. It is also shown that the direction and number of the stitches in the embroidery may influence the performance of the antenna. Moreover, the comparison of results obtained before and after the integration of the antenna into cloth shows the integration does not affect the behavior of the antenna.

  17. Research progress of laboratory diagnostic techniques for Brucella%布鲁杆菌实验室诊断技术研究进展

    Institute of Scientific and Technical Information of China (English)

    周梅

    2012-01-01

    tests play a major role in diagnosis when the bacteria cannot be detected by culture. The routine identification and differentiation of Brucellaspecies is a time-consuming and labor-intensive process which frequently places personnel at risk of laboratory-acquired infection and the bacteria from laboratory diffusion. In recent years the appeared new immunological methods and polymerase chain reaction has high sensitivity and specificity. The article reviews the laboratory diagnostic techniques and research progress of Brucella.

  18. Challenges for Frequency-Reconfigurable Antennas in Small Terminals

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Pelosi, Mauro; Pedersen, Gert Frølund

    2012-01-01

    This paper gives an overview of the techniques published over the past years to address continuous frequency tuning. It presents the challenges that have been encountered and relates to each other the parameters that influence the losses of the resulting antenna structure. A mock-up is made...

  19. Remote sensing of troposphere for aviation safety: antenna aspect

    OpenAIRE

    Yanovsky, Felix J.

    2003-01-01

    Techniques of microwave remote sensing of the atmosphere with the emphasis to the aviation applications arc considered. Some results recently obtained are presented including joint research projects of NAU and IRCTR. Specificity of antennas is discussed. The paper mainly reflects the works, which were done with author participation, and does not aspire to saturation coverage.

  20. 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 enabl...

  1. Spectrum Sensing for Cognitive Radio Based on Multiple Antennas

    DEFF Research Database (Denmark)

    Nguyen, Huan Cong; De Carvalho, Elisabeth; Prasad, Ramjee

    2012-01-01

    Spectrum sensing is a key component for enabling the cognitive radio paradigm. In this paper, we propose a novel totally-blind spectrum sensing technique for cognitive radio device equipped with multiple antennas, namely the Space Frequency Cross Product Sensing (SFCPS) algorithm. Existing...

  2. The new 34-meter antenna

    Science.gov (United States)

    Pompa, M. F.

    1986-01-01

    The new 34-m high efficiency Azimuth - Elevation antenna configuration, including its features, dynamic characteristics and performance at 8.4-GHz frequencies is described. The current-technology features of this antenna produce a highly reliable configuration by incorporation of a main wheel and track azimuth support, central pintle pivot bearing, close tolerance surface panels and all-welded construction. Also described are basic drive controls that, as slaved to three automatic microprocessors, provide accurate and safe control of the antenna's steering tasks. At this time antenna installations are completed at Goldstone and Canberra and have operationally supported the Voyager - Uranus encounter. A third installation is being constructed currently in Madrid and is scheduled for completion in late 1986.

  3. Inflatable Antennas Support Emergency Communication

    Science.gov (United States)

    2010-01-01

    Glenn Research Center awarded Small Business Innovation Research (SBIR) contracts to ManTech SRS Technologies, of Newport Beach, California, to develop thin film inflatable antennas for space communication. With additional funding, SRS modified the concepts for ground-based inflatable antennas. GATR (Ground Antenna Transmit and Receive) Technologies, of Huntsville, Alabama, licensed the technology and refined it to become the world s first inflatable antenna certified by the Federal Communications Commission. Capable of providing Internet access, voice over Internet protocol, e-mail, video teleconferencing, broadcast television, and other high-bandwidth communications, the systems have provided communication during the wildfires in California, after Hurricane Katrina in Mississippi, and following the 2010 Haiti earthquake.

  4. Dipoles, unintentional antennas and EMC

    Directory of Open Access Journals (Sweden)

    Berend Danker

    2008-01-01

    Full Text Available Radiated emissions from equipment commonly originate from electronic circuits that act as electric dipoles created by the signal voltage between the signal conductors or as magnetic dipoles formed by the signal current flowing in a loop. Direct emission is mostly small, but circuits often couple to long conductors or large wiring loops which act as antennas and are efficient radiators. A comparable situation exists when short dipole antennas or small wiring loops receive ambient noise (susceptibility. Usually the amplitude of noise sources or the susceptibility of circuits is an invariable. The dipole strength increases with the distance between the conductors and the area. Shielding and proper grounding decreases the interaction via unintentional antennas. Short-circuiting and the insertion of lossy ferrite cores reduce the efficiency of unintentional antennas.

  5. Electrically-driven optical antennas

    CERN Document Server

    Kern, Johannes; Prangsma, Jord C; Emmerling, Monika; Kamp, Martin; Hecht, Bert

    2015-01-01

    Unlike radiowave antennas, optical nanoantennas so far cannot be fed by electrical generators. Instead, they are driven by light or via optically active materials in their proximity. Here, we demonstrate direct electrical driving of an optical nanoantenna featuring an atomic-scale feed gap. Upon applying a voltage, quantum tunneling of electrons across the feed gap creates broadband quantum shot noise. Its optical frequency components are efficiently converted into photons by the antenna. We demonstrate that the properties of the emitted photons are fully controlled by the antenna architecture, and that the antenna improves the quantum efficiency by up to two orders of magnitude with respect to a non-resonant reference system. Our work represents a new paradigm for interfacing electrons and photons at the nanometer scale, e.g. for on-chip wireless data communication, electrically driven single- and multiphoton sources, as well as for background-free linear and nonlinear spectroscopy and sensing with nanometer...

  6. Diversity Gain through Antenna Blocking

    Directory of Open Access Journals (Sweden)

    V. Dehghanian

    2012-01-01

    Full Text Available As part of the typical usage mode, interaction between a handheld receiver antenna and the operator's RF absorbing body and nearby objects is known to generate variability in antenna radiation characteristics through blocking and pattern changes. It is counterintuitive that random variations in blocking can result in diversity gain of practical applicability. This diversity gain is quantified from a theoretical and experimental perspective. Measurements carried out at 1947.5 MHz verify the theoretical predictions, and a diversity gain of 3.1 dB was measured through antenna blocking and based on the utilized measurement setup. The diversity gain can be exploited to enhance signal detectability of handheld receivers based on a single antenna in indoor multipath environments.

  7. Diagnostics in critical conditions

    Directory of Open Access Journals (Sweden)

    SadchikovD.V.

    2011-09-01

    Full Text Available The purpose of research: improvement of quality of diagnostics at the patients in a critical condition in intensive care unit. Material and methods. In total have analyzed 1957 medical cards of the patients who have died in ICU»s. At the first stage studied the factors influencing on diagnostics of critically ill patients (medical cards of 1557 patients; at the second stage investigated influence of the diagnostic standards in ICU»s practice on improvement of quality of diag- nostics of critically ill patients (400 medical cards of the patients who have died. Entry criterions were standards and algorithm of diagnostics. Techniques of research: average bed-day in groups, first-day lethality, quantity of the carried out laboratory tests and tool methods of research, level of consciousness of the patients (Glasgow come score, severity of disease by ICU»s patients (APACHE II scores. Results. Quality of diagnostics depend on carried out laboratory tests and tool methods of research, level of consciousness of the patients (Glasgow come score, severity of disease by ICU»s patients (APACHE II score. The conclusion. The laboratory tests and tool methods of research conforming to the standards of diagnostics are necessary for improvement of quality of diagnostics, it is necessary to take into account an altered level of consciousness (Glasgow come score and severity of disease by ICU»s patients (APACHE II scores

  8. Integrated Lens Antennas for Multi-Pixel Receivers

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam

    2011-01-01

    Future astrophysics and planetary experiments are expected to require large focal plane arrays with thousands of detectors. Feedhorns have excellent performance, but their mass, size, fabrication challenges, and expense become prohibitive for very large focal plane arrays. Most planar antenna designs produce broad beam patterns, and therefore require additional elements for efficient coupling to the telescope optics, such as substrate lenses or micromachined horns. An antenna array with integrated silicon microlenses that can be fabricated photolithographically effectively addresses these issues. This approach eliminates manual assembly of arrays of lenses and reduces assembly errors and tolerances. Moreover, an antenna array without metallic horns will reduce mass of any planetary instrument significantly. The design has a monolithic array of lens-coupled, leaky-wave antennas operating in the millimeter- and submillimeter-wave frequencies. Electromagnetic simulations show that the electromagnetic fields in such lens-coupled antennas are mostly confined in approximately 12 15 . This means that one needs to design a small-angle sector lens that is much easier to fabricate using standard lithographic techniques, instead of a full hyper-hemispherical lens. Moreover, this small-angle sector lens can be easily integrated with the antennas in an array for multi-pixel imager and receiver implementation. The leaky antenna is designed using double-slot irises and fed with TE10 waveguide mode. The lens implementation starts with a silicon substrate. Photoresist with appropriate thickness (optimized for the lens size) is spun on the substrate and then reflowed to get the desired lens structure. An antenna array integrated with individual lenses for higher directivity and excellent beam profile will go a long way in realizing multi-pixel arrays and imagers. This technology will enable a new generation of compact, low-mass, and highly efficient antenna arrays for use in multi

  9. Living antennas on communication satellites

    DEFF Research Database (Denmark)

    Lumholt, Michael

    2003-01-01

    Crises change the global pattern of communication. The communications problems occur because the satellites are optimized to cover specific geographic areas, and these areas cannot be altered once the satellites are in Earth orbit. An effective solution to the problem is to equip communication sa...... satellites with "living" antennas that can adjust their radiation coverage areas according to the new demands. The development of living antennas is, therefore, among the focus areas identified and supported by the European Space Agency, ESA....

  10. Plasmonic antenna effects on photochemical reactions.

    Science.gov (United States)

    Gao, Shuyan; Ueno, Kosei; Misawa, Hiroaki

    2011-04-19

    , from visible to near-infrared wavelengths. In this Account, we describe our recent work in using metallic nanostructures to assist photochemical reactions for augmenting photoexcitation efficiency. These studies investigate the optical antenna effects of coupled plasmonic gold nanoblocks, which were fabricated with electron-beam lithography and a lift-off technique to afford high resolution and nanometric accuracy. The two-photon photoluminescence of gold and the resulting nonlinear photopolymerization on gold nanoblocks substantiate the existence of enhanced optical field domains. Local two-photon photochemical reactions due to weak incoherent light sources were identified. The optical antenna effects support the unprecedented realization of (i) direct photocarrier injection from the gold nanorods into TiO(2) and (ii) efficient and stable photocurrent generation in the absence of electron donors from visible (450 nm) to near-infrared (1300 nm) wavelengths.

  11. Computation of antenna pattern correlation and MIMO performance by means of surface current distribution and spherical wave theory

    Directory of Open Access Journals (Sweden)

    O. Klemp

    2006-01-01

    Full Text Available In order to satisfy the stringent demand for an accurate prediction of MIMO channel capacity and diversity performance in wireless communications, more effective and suitable models that account for real antenna radiation behavior have to be taken into account. One of the main challenges is the accurate modeling of antenna correlation that is directly related to the amount of channel capacity or diversity gain which might be achieved in multi element antenna configurations. Therefore spherical wave theory in electromagnetics is a well known technique to express antenna far fields by means of a compact field expansion with a reduced number of unknowns that was recently applied to derive an analytical approach in the computation of antenna pattern correlation. In this paper we present a novel and efficient computational technique to determine antenna pattern correlation based on the evaluation of the surface current distribution by means of a spherical mode expansion.

  12. Radiation Characteristics of the Cavity Backed Antenna in Conducting Cone

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A technique using finite element and boundary integral method (FE-BI) and reciprocity theorem is presented to analyze the radiation characteristics of cavity backed antenna mounted on a conducting cone. The electric fields inside the cavity and on the aperture are obtained using finite element and boundary integral method. The far-field characteristic of the antenna is computed using reciprocity theorem. The paper begins with a general description of the method. An application of this method is given and the numerical result is compared with the experimental result.

  13. Submillimeter Wave Antenna With Slow Wave Feed Line

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Kotiranta, Mikko

    2009-01-01

    Submillimeter wave radiation, which is also referred to as terahertz radiation, has not been extensively explored until recently due to a lack of reliable components and devices in this frequency range. Current advances in technology have made it possible to explore this portion...... of the electromagnetic spectrum, and to create innovative imaging and sensing techniques that hold enormous potential in biomedical, metrological and security applications. Considering that realization of submillimeter wave components and antennas is still heavily constrained by problems arising from technological...... to directly radiate energy from a vane-type interaction structure of a vacuum electron device. The parameters of the antenna are optimized while taking the technological constraints into account....

  14. Robust Hybrid Finite Element Methods for Antennas and Microwave Circuits

    Science.gov (United States)

    Gong, J.; Volakis, John L.

    1996-01-01

    One of the primary goals in this dissertation is concerned with the development of robust hybrid finite element-boundary integral (FE-BI) techniques for modeling and design of conformal antennas of arbitrary shape. Both the finite element and integral equation methods will be first overviewed in this chapter with an emphasis on recently developed hybrid FE-BI methodologies for antennas, microwave and millimeter wave applications. The structure of the dissertation is then outlined. We conclude the chapter with discussions of certain fundamental concepts and methods in electromagnetics, which are important to this study.

  15. Transmit antenna selection based on shadowing side information

    KAUST Repository

    Yilmaz, Ferkan

    2011-05-01

    In this paper, we propose a new transmit antenna selection scheme based on shadowing side information. In the proposed scheme, single transmit antenna which has the highest shadowing coefficient is selected. By the proposed technique, usage of the feedback channel and channel estimation complexity at the receiver can be reduced. We consider independent but not identically distributed Generalized-K composite fading model, which is a general composite fading & shadowing channel model for wireless environments. Exact closed-form outage probability, moment generating function and symbol error probability expressions are derived. In addition, theoretical performance results are validated by Monte Carlo simulations. © 2011 IEEE.

  16. Wideband Antenna for HPM Measurements

    Directory of Open Access Journals (Sweden)

    Kurkan Ivan

    2016-01-01

    Full Text Available The measurements of microwave pulses of gigawatt power level have a lot of constraints. A receiving antenna is a starting and core point of the measurement system. Waveguide based and dipole antennas have a limited wide bands, while the use of commercially available wideband antennas is restricted by their maximum peak power acceptances. The design of the wide band antenna with the small effective area was proposed. The characteristics of prototype were obtained in numerical simulations with ANSYS HFSS software and by calibration tests in the frequency band of 1–13 GHz. It has the effective area about the 1 mm2 in X-band and square-law dependence on the wavelength in a wide band. The cross polarization rate is more than 60 dB at the centre position and not less than 30 dB within the range of ±5° in azimuth and elevation angle. The wide beam radiation pattern forces a user to discriminate reflected signals. This antenna could greatly simplify the measurement system, replacing a set of narrow band antennas that connected to several recording channels.

  17. Novel metamaterial based antennas for flexible wireless systems

    Science.gov (United States)

    Khaleel, Haider Raad

    Recent years have witnessed a great deal of interest from both academia and industry in the field of flexible electronic systems. This research topic tops the pyramid of research priorities requested by many national research agencies. Consistently, flexible electronic systems require the integration of flexible antennas operating in specific frequency bands to provide wireless connectivity which is highly demanded by today's information oriented society. On the other hand, metamaterials have become very popular in the design of contemporary antenna and microwave devices due to their wide range of applications derived from their unique properties which significantly enhances the performance of antennas and RF systems. Accordingly, the integration of metamaterial structures within flexible wireless systems is very beneficial in this growing field of research. A systematic approach to the analysis and design of flexible and conformal antennas and metamaterials is ultimately needed. The research reported in this thesis focuses on developing flexible low profile antennas and metamaterial structures in addition to characterizing their performance when integrated within flexible wireless systems. Three flexible, compact, and extremely low profile (50.8 microm) antennas intended for WLAN, Bluetooth and Ultra Wide Band (UWB) applications are presented. Next, a novel miniaturized Artificial Magnetic Conductor (AMC) and a new technique to enhance the bandwidth of micro-Negative (MNG) metamaterial are reported. Furthermore, the effect of bending on the AMC and MNG metamaterial is investigated in this thesis for the first time. Finally, the findings of this research are utilized in practical applications with specific design constraints including mutual coupling reduction between radiating elements in antenna arrays and MIMO systems and Specific Absorption Rate (SAR) reduction in telemedicine systems.

  18. An active antenna for ELF magnetic fields

    Science.gov (United States)

    Sutton, John F.; Spaniol, Craig

    1994-01-01

    The work of Nikola Tesla, especially that directed toward world-wide electrical energy distribution via excitation of the earth-ionosphere cavity resonances, has stimulated interest in the study of these resonances. Not only are they important for their potential use in the transmission of intelligence and electrical power, they are important because they are an integral part of our natural environment. This paper describes the design of a sensitive, untuned, low noise active antenna which is uniquely suited to modern earth-ionosphere cavity resonance measurements employing fast-Fourier transform techniques for near-real-time data analysis. It capitalizes on a little known field-antenna interaction mechanism. Recently, the authors made preliminary measurements of the magnetic fields in the earth-ionosphere cavity. During the course of this study, the problem of designing an optimized ELF magnetic field sensor presented itself. The sensor would have to be small, light weight (for portable use), and capable of detecting the 5-50 Hz picoTesla-level signals generated by the natural excitations of the earth-ionosphere cavity resonances. A review of the literature revealed that past researchers had employed very large search coils, both tuned and untuned. Hill and Bostick, for example, used coils of 30,000 turns wound on high permeability cores of 1.83 m length, weighing 40 kg. Tuned coils are unsuitable for modern fast-Fourier transform data analysis techniques which require a broad spectrum input. 'Untuned' coils connected to high input impedance voltage amplifiers exhibit resonant responses at the resonant frequency determined by the coil inductance and the coil distributed winding capacitance. Also, considered as antennas, they have effective areas equal only to their geometrical areas.

  19. Novel Base Station MIMO Antennas with Enhanced Spectral Efficiencies Using Angular Reuse

    Directory of Open Access Journals (Sweden)

    Miguel Mora-Andreu

    2015-01-01

    Full Text Available The true polarization diversity (TPD technique is combined with the spatial diversity technique in novel MIMO antenna array geometries with a large number of elements. The use of a large number of elements requires some angular reuse within the array for polarization diversity. With designs compatible with existing base station antenna array configurations, the novel geometries with combining diversity schemes are shown to be able to achieve near the maximum spectral efficiencies. True polarization diversity (TPD schemes are found to be an excellent complement to more conventional spatial diversity schemes for obtaining optimum MIMO array performance in base station antennas.

  20. On the prospects of ultra-high energy cosmic rays detection by high altitude antennas

    CERN Document Server

    Motloch, P; Privitera, P

    2013-01-01

    Radio emission from Ultra-High Energy Cosmic Rays (UHECR) showers detected after specular reflection off the Antarctic ice surface has been recently demonstrated by the ANITA balloon-borne experiment. An antenna observing a large area of ice or water from a mountaintop, a balloon or a satellite may be competitive with more conventional techniques. We present an estimate of the exposure of a high altitude antenna, which provides insight on the prospects of this technique for UHECR detection.