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Sample records for frequency mini-rf technology

  1. The Miniature Radio Frequency Instruments (Mini-RF) Global Observations of Earth's Moon

    Science.gov (United States)

    Cahill, Joshua T. S.; Thomson, B. J.; Patterson, G. Wesley; Bussey, D. Benjamin J.; Neish, Catherine D.; Lopez, Norberto R.; Turner, F. Scott; Aldridge, T.; McAdam, M.; Meyer, H. M.; Raney, R. K.; Carter, L. M.; Spudis, P. D.; Hiesinger, H.; Pasckert, J. H.

    2014-01-01

    Radar provides a unique means to analyze the surface and subsurface physical properties of geologic deposits, including their wavelength-scale roughness, the relative depth of the deposits, and some limited compositional information. The NASA Lunar Reconnaissance Orbiter's (LRO) Miniature Radio Frequency (Mini-RF) instrument has enabled these analyses on the Moon at a global scale. Mini-RF has accumulated 67% coverage of the lunar surface in S-band (12.6 cm) radar with a resolution of 30 m/pixel. Here we present new Mini-RF global orthorectified uncontrolled S-band maps of the Moon and use them for analysis of lunar surface physical properties. Reported here are readily apparent global- and regional-scale differences in lunar surface physical properties that suggest three distinct terranes, namely: a (1) Nearside Radar Dark Region; (2) Orientale basin and continuous ejecta; and the (3) Highlands Radar Bright Region. Integrating these observations with new data from LRO's Diviner Radiometer rock abundance maps, as well Clementine and Lunar Prospector derived compositional values show multiple distinct lunar surface terranes and sub-terranes based upon both physical and compositional surface properties. Previous geochemical investigations of the Moon suggested its crust is best divided into three to four basic crustal provinces or terranes (Feldspathic Highlands Terrane (-An and -Outer), Procellarum KREEP Terrane, and South Pole Aitken Terrane) that are distinct from one another. However, integration of these geochemical data sets with new geophysical data sets allows us to refine these terranes. The result shows a more complex view of these same crustal provinces and provides valuable scientific and hazard perspectives for future targeted human and robotic exploration.

  2. Mini-RF Image Processing and Data Product Generation

    Science.gov (United States)

    Turner, F. S.; Espiritu, R. C.; Patterson, G. W.; Stickle, A. M.; Cahill, J. T. S.

    2017-06-01

    Mini-RF on LRO currently operates in concert with the Arecibo Observatory and the Goldstone DSS-13 34 meter antenna to collect S- and X-band bistatic radar data of the lunar nearside. We describe the processing and archiving of those data.

  3. Bistatic radar observations of the Moon using Mini-RF on LRO and the Arecibo Observatory

    Science.gov (United States)

    Patterson, G. W.; Stickle, A. M.; Turner, F. S.; Jensen, J. R.; Bussey, D. B. J.; Spudis, P.; Espiritu, R. C.; Schulze, R. C.; Yocky, D. A.; Wahl, D. E.; Zimmerman, M.; Cahill, J. T. S.; Nolan, M.; Carter, L.; Neish, C. D.; Raney, R. K.; Thomson, B. J.; Kirk, R.; Thompson, T. W.; Tise, B. L.; Erteza, I. A.; Jakowatz, C. V.

    2017-02-01

    The Miniature Radio Frequency (Mini-RF) instrument aboard NASA's Lunar Reconnaissance Orbiter (LRO) is a hybrid dual-polarized synthetic aperture radar (SAR) that operated in concert with the Arecibo Observatory to collect bistatic radar data of the lunar nearside from 2012 to 2015. The purpose of this bistatic campaign was to characterize the radar scattering properties of the surface and near-surface, as a function of bistatic angle, for a variety of lunar terrains and search for a coherent backscatter opposition effect indicative of the presence of water ice. A variety of lunar terrain types were sampled over a range of incidence and bistatic angles; including mare, highland, pyroclastic, crater ejecta, and crater floor materials. Responses consistent with an opposition effect were observed for the ejecta of several Copernican-aged craters and the floor of the south-polar crater Cabeus. The responses of ejecta material varied by crater in a manner that suggests a relationship with crater age. The response for Cabeus was observed within the portion of its floor that is not in permanent shadow. The character of the response differs from that of crater ejecta and appears unique with respect to all other lunar terrains observed. Analysis of data for this region suggests that the unique nature of the response may indicate the presence of near-surface deposits of water ice.

  4. a Semi-Rigorous Sensor Model for Precision Geometric Processing of Mini-Rf Bistatic Radar Images of the Moon

    Science.gov (United States)

    Kirk, R. L.; Barrett, J. M.; Wahl, D. E.; Erteza, I.; Jackowatz, C. V.; Yocky, D. A.; Turner, S.; Bussey, D. B. J.; Paterson, G. W.

    2016-06-01

    The spaceborne synthetic aperture radar (SAR) instruments known as Mini-RF were designed to image shadowed areas of the lunar poles and assay the presence of ice deposits by quantitative polarimetry. We have developed radargrammetric processing techniques to enhance the value of these observations by removing spacecraft ephemeris errors and distortions caused by topographic parallax so the polarimetry can be compared with other data sets. Here we report on the extension of this capability from monostatic imaging (signal transmitted and received on the same spacecraft) to bistatic (transmission from Earth and reception on the spacecraft) which provides a unique opportunity to measure radar scattering at nonzero phase angles. In either case our radargrammetric sensor models first reconstruct the observed range and Doppler frequency from recorded image coordinates, then determine the ground location with a corrected trajectory on a more detailed topographic surface. The essential difference for bistatic radar is that range and Doppler shift depend on the transmitter as well as receiver trajectory. Incidental differences include the preparation of the images in a different (map projected) coordinate system and use of "squint" (i.e., imaging at nonzero rather than zero Doppler shift) to achieve the desired phase angle. Our approach to the problem is to reconstruct the time-of-observation, range, and Doppler shift of the image pixel by pixel in terms of rigorous geometric optics, then fit these functions with low-order polynomials accurate to a small fraction of a pixel. Range and Doppler estimated by using these polynomials can then be georeferenced rigorously on a new surface with an updated trajectory. This "semi-rigorous" approach (based on rigorous physics but involving fitting functions) speeds the calculation and avoids the need to manage both the original and adjusted trajectory data. We demonstrate the improvement in registration of the bistatic images for

  5. A SEMI-RIGOROUS SENSOR MODEL FOR PRECISION GEOMETRIC PROCESSING OF MINI-RF BISTATIC RADAR IMAGES OF THE MOON

    National Research Council Canada - National Science Library

    R. L. Kirk; J. M. Barrett; D. E. Wahl; I. Erteza; C. V. Jackowatz; D. A. Yocky; S. Turner; D. B. J. Bussey; G. W. Paterson

    2016-01-01

    The spaceborne synthetic aperture radar (SAR) instruments known as Mini-RF were designed to image shadowed areas of the lunar poles and assay the presence of ice deposits by quantitative polarimetry...

  6. Generating lunar bistatic SAR images using Arecibo and Mini-RF

    Science.gov (United States)

    Wahl, Daniel E.; Yocky, David A.; Bussey, Ben; Jakowatz, Charles V., Jr.

    2012-05-01

    We have employed the Arecibo Observatory Planetary Radar (AO) transmitter and the Mini-RF radar onboard NASA's Lunar Reconnaissance Orbiter (LRO) as a receiver to collect bistatic data of the lunar surface. In this paper, we demonstrate the ability to form bistatic polarimetric imagery with spatial resolution on the order of 50m, and to create polarimetric maps that could potentially reveal the presence of ice in lunar permanently shadowed craters. We discuss the details of the signal processing techniques that are required to allow these products to be formed.

  7. Bistatic Radar Observations of the Moon using MINI-RF on LRO and the Arecibo Observatory

    Science.gov (United States)

    Patterson, G.; Bussey, B.

    2013-12-01

    The Mini-RF team is acquiring bistatic radar measurements of the lunar surface to understand the scattering properties of materials as a function of phase angle. These observations have produced the first lunar bistatic radar images ever collected with non-zero phase angles. The goal of these observations is to differentiate between scatter-ing indicative of surfaces that are rough versus surfaces that harbor water ice in quantities detectible by a radar sys-tem operating at a wavelength of 12.6 cm. Radar observations of planetary surfaces provide unique information on the structure (i.e., roughness) and dielec-tric properties of surface and buried materials. These data can be acquired using a monostatic architecture, where a single antenna serves as the signal transmitter and receiver, or they can be acquired using a bistatic architecture, where a signal is transmitted from one location and received at another. The former provides information on the scattering properties of a target surface at zero phase. The latter provides the same information over a variety of phase angles. NASA's Mini-RF instrument on the Lunar Reconnaissance Orbiter and the Arecibo Observatory in Puerto Rico are currently operating in a bistatic architecture (the Arecibo Observatory serves as the transmitter and Mini-RF serves as the receiver). This architecture maintains the hybrid dual-polarimetric nature of the Mini-RF in-strument and, therefore, allows for the calculation of the Stokes parameters (S1, S2, S3, S4) that characterize the backscattered signal (and the products derived from those parameters). A common product derived from the Stokes parameters is the Circular Polarization Ratio (CPR). High CPR val-ues can serve as an indicator of rough surfaces or as an indicator of the presence of water ice. Recent work using monostatic radar data and inferences from surface geology suggests that anomalously high CPR values associated with some polar lunar craters are indicative of the

  8. Lunar Field Geological Interpretations Assisted by LROC, Mini-RF and M3: Taurus-Littrow

    Science.gov (United States)

    Schmitt, H. H.; Petro, N. E.; Robinson, M. S.; Wells, R.; Weiss, B. P.; Mercer, C. M.

    2015-12-01

    Integration of Apollo 17 field observations and photographs, sample investigations, Lunar Reconnaissance Orbiter Camera images, Moon Mineralogical Mapper data, and Mini-RF images provides new insights into the geology of the valley of Taurus Littrow. Samples from the North Massif and the Sculptured Hills appear to represent a stratigraphic sequence of ejecta from the Cranium and Serenitatis basin-forming events. Published analyses of these samples provide the approximate ages for those events that appear consistent with this sequence; however, within current 2 sigma error limits, these ages overlap. Strong evidence exists that the Sculptured Hills physiographic unit consists of Imbrium ejecta made up of a layered, Mg-suite pluton. Rim boulders at Camelot Crater constitute wall rocks of the crater rather than ejecta and provide a potential opportunity for investigations of remnant magnetic field orientation at the time of the eruption of late mare basalt lavas in the valley. A second and older light mantle avalanche deposit has been identified, and the origin, potential fluidized flow mechanisms, and geology of the two avalanches from the South Massif have been clarified, including the probability of significant agitation heating during flow. The structure, potential effects, and timing of the Lee-Lincoln thrust fault, and of an ancillary fault revealed by radar, have been defined and raise doubts about the association of the light mantle avalanche with secondary impacts related to the Tycho event.

  9. Mini-RF and Arecibo Observatory Bistatic Observations of the Moon

    Science.gov (United States)

    Patterson, G.; Bussey, B.; Stickle, A. M.; Turner, F. S.; Jensen, J. R.; Nolan, M. C.; Yocky, D. A.; Wahl, D. E.

    2015-12-01

    The Mini-RF instrument aboard NASA's Lunar Reconnaissance Orbiter (LRO) is a hybrid dual-polarized synthetic aperture radar (SAR) and has been operating in concert with the Arecibo Observatory since 2012 to collect bistatic radar data of the Moon. Approximately 28 bistatic observations, covering a variety of terrains on the lunar nearside, have been made using this mode of operation. Laboratory data and analog experiments, at optical wavelengths, have shown that the scattering properties of lunar materials (e.g., the roughness) can be sensitive to variations in bistatic angle. This sensitivity manifests as an opposition effect and likely involves contributions from shadow hiding at low angles and coherent backscatter near 0°. Analog experiments and theoretical work have shown that water ice is also sensitive to variations in bistatic angle. Differences in the character of the opposition response of these materials offer an opportunity to differentiate between them, an issue that has been problematic for previous radar studies of the Moon. Observations that include mare materials, highland materials, and pyroclastic deposits have not shown an opposition response over for bistatic angles of ~0.1° to 30°. Observations of the ejecta blankets of young, fresh craters have shown an opposition response for the same range of bistatic angles. The character of the response varies for each crater and is likely related to differences in target properties of the surface and exposure age of the blanket. Observations of portions of the floor of the south polar crater Cabeus have also been acquired for the same range of bistatic angles. The character of the radar response from the crater, as a function of bistatic angle, appears unique with respect to all other lunar terrains observed.

  10. Evidence for water ice on the moon: Results for anomalous polar craters from the LRO Mini-RF imaging radar

    Science.gov (United States)

    Spudis, P. D.; Bussey, D. B. J.; Baloga, S. M.; Cahill, J. T. S.; Glaze, L. S.; Patterson, G. W.; Raney, R. K.; Thompson, T. W.; Thomson, B. J.; Ustinov, E. A.

    2013-10-01

    The Mini-RF radar instrument on the Lunar Reconnaissance Orbiter spacecraft mapped both lunar poles in two different RF wavelengths (complete mapping at 12.6 cm S-band and partial mapping at 4.2 cm X-band) in two look directions, removing much of the ambiguity of previous Earth- and spacecraft-based radar mapping of the Moon's polar regions. The poles are typical highland terrain, showing expected values of radar cross section (albedo) and circular polarization ratio (CPR). Most fresh craters display high values of CPR in and outside the crater rim; the pattern of these CPR distributions is consistent with high levels of wavelength-scale surface roughness associated with the presence of block fields, impact melt flows, and fallback breccia. A different class of polar crater exhibits high CPR only in their interiors, interiors that are both permanently dark and very cold (less than 100 K). Application of scattering models developed previously suggests that these anomalously high-CPR deposits exhibit behavior consistent with the presence of water ice. If this interpretation is correct, then both poles may contain several hundred million tons of water in the form of relatively "clean" ice, all within the upper couple of meters of the lunar surface. The existence of significant water ice deposits enables both long-term human habitation of the Moon and the creation of a permanent cislunar space transportation system based upon the harvest and use of lunar propellant.

  11. Evidence for Water Ie on the Moon: Results for Anomalous Polar Craters from the LRO Mini-RF Imaging Radar

    Science.gov (United States)

    Spudis, P.D.; Bussey, D. B. J.; Baloga, S. M.; Cahill, J. T. S.; Glaze, L. S.; Patterson, G. W.; Raney, R. K.; Thompson, T. W.; Thomson, B. J.; Ustinov, E. A.

    2013-01-01

    The Mini-RF radar instrument on the Lunar Reconnaissance Orbiter spacecraft mapped both lunar poles in two different RF wavelengths (complete mapping at 12.6 cm S-band and partial mapping at 4.2 cm X-band) in two look directions, removing much of the ambiguity of previous Earth- and spacecraft-based radar mapping of the Moon's polar regions. The poles are typical highland terrain, showing expected values of radar cross section (albedo) and circular polarization ratio (CPR). Most fresh craters display high values of CPR in and outside the crater rim; the pattern of these CPR distributions is consistent with high levels of wavelength-scale surface roughness associated with the presence of block fields, impact melt flows, and fallback breccia. A different class of polar crater exhibits high CPR only in their interiors, interiors that are both permanently dark and very cold (less than 100 K). Application of scattering models developed previously suggests that these anomalously high-CPR deposits exhibit behavior consistent with the presence of water ice. If this interpretation is correct, then both poles may contain several hundred million tons of water in the form of relatively "clean" ice, all within the upper couple of meters of the lunar surface. The existence of significant water ice deposits enables both long-term human habitation of the Moon and the creation of a permanent cislunar space transportation system based upon the harvest and use of lunar propellant.

  12. Evidence for Water Ice on the Moon: Results for Anomalous Polar Craters from the LRO Mini-RF Imaging Radar

    Science.gov (United States)

    Spudis, P. D.; Bussey, D. B. J.; Baloga, S. M.; Cahill, J. T. S.; Glaze, L. S.; Patterson, G. W.; Raney, R. K.; Thompson, T. W.; Thomson, B. J.; Ustinov, E. A.

    2013-01-01

    The Mini-RF radar instrument on the Lunar Reconnaissance Orbiter spacecraft mapped both lunar poles in two different RF wavelengths (complete mapping at 12.6 cm S-band and partial mapping at 4.2 cm X-band) in two look directions, removing much of the ambiguity of previous Earth- and spacecraft-based radar mapping of the Moon's polar regions. The poles are typical highland terrain, showing expected values of radar cross section (albedo) and circular polarization ratio (CPR). Most fresh craters display high values of CPR in and outside the crater rim; the pattern of these CPR distributions is consistent with high levels of wavelength-scale surface roughness associated with the presence of block fields, impact melt flows, and fallback breccia. A different class of polar crater exhibits high CPR only in their interiors, interiors that are both permanently dark and very cold (less than 100 K). Application of scattering models developed previously suggests that these anomalously high-CPR deposits exhibit behavior consistent with the presence of water ice. If this interpretation is correct, then both poles may contain several hundred million tons of water in the form of relatively "clean" ice, all within the upper couple of meters of the lunar surface. The existence of significant water ice deposits enables both long-term human habitation of the Moon and the creation of a permanent cislunar space transportation system based upon the harvest and use of lunar propellant.

  13. SITE TECHNOLOGY CAPSULE: IITRI RADIO FREQUENCY HEATING TECHNOLOGY

    Science.gov (United States)

    Radio frequency heating (RFH) technologies use electromagnetic energy in the radio frequency (RF) band to heat soil in situ, thereby potentially enhancing the performance of standard soil vapor extraction (SVE) technologies. Contaminants are removed from in situ soils and transfe...

  14. INNOVATIVE TECHNOLOGY EVALUATION REPORT: RADIO FREQUENCY HEATING, KAI TECHNOLOGIES, INC.

    Science.gov (United States)

    A demonstration of KAI Technologies in-situ radio frequency heating system for soil treatment was conducted from January 1994 to July 1994 at Kelly Air Force Base in San Antonio, Texas. This demonstration was conducted as a joint effort between the USEPA and the USAF. The technol...

  15. 78 FR 70567 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final...

    Science.gov (United States)

    2013-11-26

    ...] Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final Programmatic... Programmatic Environmental Assessment (PEA) for the Nationwide Use of High Frequency (HF) and Ultra High Frequency (UHF) Sound Navigation and Ranging (SONAR) Technology and Finding of No Significant Impact (FONSI...

  16. DEMONSTRATION BULLETIN: RADIO FREQUENCY HEATING - KAI TECHNOLOGIES, INC.

    Science.gov (United States)

    Radio frequency heating (RFH) is a process that uses electromagnetic energy in the radio frequency (RF) band to heat soil in situ, thereby potentially enhancing the performance of standard soil vapor extraction (SVE) technologies. An RFH system developed by KAI Technologies, I...

  17. 75 FR 81284 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Draft...

    Science.gov (United States)

    2010-12-27

    ... SONAR technologies that operate at frequencies of 50 kiloHertz (kHz) and greater from mobile platforms... proposes to use HF and UHF SONAR technology from mobile platforms nationwide. Mobile platforms include...-specific, non-mobile operating scenarios or newly developed technologies fall outside of the scope of...

  18. How can radio frequency identification technology impact nursing practice?

    Science.gov (United States)

    Billingsley, Luanne; Wyld, David

    2014-12-01

    Radio frequency identification (RFID) technology can save nurses time, improve quality of care, en hance patient and staff safety, and decrease costs. However, without a better understanding of these systems and their benefits to patients and hospitals, nurses may be slower to recommend, implement, or adopt RFID technology into practice.

  19. Superconducting Radio Frequency Technology: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Peter Kneisel

    2003-06-01

    Superconducting RF cavities are becoming more often the choice for larger scale particle accelerator projects such as linear colliders, energy recovery linacs, free electron lasers or storage rings. Among the many advantages compared to normal conducting copper structures, the superconducting devices dissipate less rf power, permit higher accelerating gradients in CW operation and provide better quality particle beams. In most cases these accelerating cavities are fabricated from high purity bulk niobium, which has superior superconducting properties such as critical temperature and critical magnetic field when compared to other superconducting materials. Research during the last decade has shown, that the metallurgical properties--purity, grain structure, mechanical properties and oxidation behavior--have significant influence on the performance of these accelerating devices. This contribution attempts to give a short overview of the superconducting RF technology with emphasis on the importance of the material properties of the high purity niobium.

  20. SITE TECHNOLOGY CAPSULE: KAI RADIO FREQUENCY HEATING TECHNOLOGY

    Science.gov (United States)

    KAI developed a patented, in situ RFH technology to enhance the removal of volatile and semi-volatile organics by soil vapor extraction (SVE). Electromagnetic energy heats the soil resulting in increased contaminant vapor pressures and soil permeability that may increase with dry...

  1. IITRI RADIO FREQUENCY HEATING TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    IITRI's patented in situ RFH technology enhances the removal of volatile and semi-volatile organics by soil vapor extraction (SVE). Electromagnetic energy heats the soil resulting in increased contaminant vapor pressures and potentially higher soil permeability. RFH heats soil us...

  2. IITRI RADIO FREQUENCY HEATING TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    IITRI's patented in situ RFH technology enhances the removal of volatile and semi-volatile organics by soil vapor extraction (SVE). Electromagnetic energy heats the soil resulting in increased contaminant vapor pressures and potentially higher soil permeability. RFH heats soil us...

  3. RFID explained a primer on radio frequency identification technologies

    CERN Document Server

    Want, Roy

    2006-01-01

    This lecture provides an introduction to Radio Frequency Identification (RFID), a technology enabling automatic identification of objects at a distance without requiring line-of-sight. Electronic tagging can be divided into technologies that have a power source (active tags), and those that are powered by the tag interrogation signal (passive tags); the focus here is on passive tags. An overview of the principles of the technology divides passive tags into devices that use either near field or far field coupling to communicate with a tag reader. The strengths and weaknesses of the approaches a

  4. Femtosecond Optical Frequency Comb Technology Principle, Operation and Application

    CERN Document Server

    Ye, Jun

    2005-01-01

    Over the last few years, there has been a remarkable convergence among the fields of ultrafast optics, optical frequency metrology, and precision laser spectroscopy. This convergence has enabled unprecedented advances in control of the electric field of the pulses produced by femtosecond mode-locked lasers. The resulting spectrum consists of a comb of sharp spectral lines with well-defined frequencies. These new techniques and capabilities are generally known as "femtosecond comb technology." They have had dramatic impact on the diverse fields of precision measurement and extreme nonlinear optical physics. This book provides an introductory description of mode-locked lasers, the connection between time and frequency descriptions of their output and the physical origins of the electric field dynamics, together with an overview of applications of femtosecond comb technology. Individual chapters go into more detail on mode-locked laser development, spectral broadening in microstructure fiber, optical parametric ...

  5. Biomedical Monitoring By A Novel Noncontact Radio Frequency Technology Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J. (Compiler)

    2014-01-01

    The area of Space Health and Medicine is one of the NASA's Space Technology Grand Challenges. Space is an extreme environment which is not conducive to human life. The extraterrestrial environment can result in the deconditioning of various human physiological systems and thus require easy to use physiological monitoring technologies in order to better monitor space crews for appropriate health management and successful space missions and space operations. Furthermore, the Space Technology Roadmap's Technology Area Breakdown Structure calls for improvements in research to support human health and performance (Technology Area 06). To address these needs, this project investigated a potential noncontact and noninvasive radio frequency-based technique of monitoring central hemodynamic function in human research subjects in response to orthostatic stress.

  6. INTEGRATING RADIO FREQUENCY IDENTIFICATION TECHNOLOGY IN ACADEMIC MANAGEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    Zainab Rasheed Mirza

    2014-01-01

    Full Text Available The purpose of this study is building a web and windows based intelligent system using web technologies, biometric and Radio Frequency Identification technologies (RFID to strengthen an Academic Management System (AMS in a campus for monitoring and improving academic performance of teachers and students. A campus mobile phone application will allow guardians to monitor student’s movement history at campus, e-payments and food choices at canteen, class attendance, exam attendance and academic performance on daily basis. Mobile application for students will allow students to view their class schedules, teacher appointments, e-payment statement, warnings or announcements, locate their exam halls and search for classrooms.

  7. Technologies for Low Frequency Radio Observations of the Cosmic Dawn

    Science.gov (United States)

    Jones, Dayton L.

    2014-01-01

    The Jet Propulsion Laboratory (JPL) is developing concepts and technologies for low frequency radio astronomy space missions aimed at observing highly redshifted neutral Hydrogen from the Dark Ages. This is the period of cosmic history between the recombination epoch when the microwave background radiation was produced and the re-ionization of the intergalactic medium by the first generation of stars (Cosmic Dawn). This period, at redshifts greater than about 20, is a critical epoch for the formation and evolution of large-scale structure in the universe. The 21-cm spectral line of Hydrogen provides the most promising method for directly studying the Dark Ages, but the corresponding frequencies at such large redshifts are only tens of MHz and thus require space-based observations to avoid terrestrial RFI and ionospheric absorption and refraction. This paper reports on the status of several low frequency technology development activities at JPL, including deployable bi-conical dipoles for a planned lunar-orbiting mission, and both rover-deployed and inflation-deployed long dipole antennas for use on the lunar surface.

  8. Radio Frequency Identification (RFID) technology and patient safety.

    Science.gov (United States)

    Ajami, Sima; Rajabzadeh, Ahmad

    2013-09-01

    Radio frequency identification (RFID) systems have been successfully applied in areas of manufacturing, supply chain, agriculture, transportation, healthcare, and services to name a few. However, the different advantages and disadvantages expressed in various studies of the challenges facing the technology of the use of the RFID technology have been met with skepticism by managers of healthcare organizations. The aim of this study was to express and display the role of RFID technology in improving patient safety and increasing the impact of it in healthcare. This study was non-systematical review, which the literature search was conducted with the help of libraries, books, conference proceedings, PubMed databases and also search engines available at Google, Google scholar in which published between 2004 and 2013 during Febuary 2013. We employed the following keywords and their combinations; RFID, healthcare, patient safety, medical errors, and medication errors in the searching areas of title, keywords, abstract, and full text. The preliminary search resulted in 68 articles. After a careful analysis of the content of each paper, a total of 33 papers was selected based on their relevancy. We should integrate RFID with hospital information systems (HIS) and electronic health records (EHRs) and support it by clinical decision support systems (CDSS), it facilitates processes and reduce medical, medication and diagnosis errors.

  9. Radio Frequency Identification (RFID technology and patient safety

    Directory of Open Access Journals (Sweden)

    Sima Ajami

    2013-01-01

    Full Text Available Background: Radio frequency identification (RFID systems have been successfully applied in areas of manufacturing, supply chain, agriculture, transportation, healthcare, and services to name a few. However, the different advantages and disadvantages expressed in various studies of the challenges facing the technology of the use of the RFID technology have been met with skepticism by managers of healthcare organizations. The aim of this study was to express and display the role of RFID technology in improving patient safety and increasing the impact of it in healthcare. Materials and Methods: This study was non-systematical review, which the literature search was conducted with the help of libraries, books, conference proceedings, PubMed databases and also search engines available at Google, Google scholar in which published between 2004 and 2013 during Febuary 2013. We employed the following keywords and their combinations; RFID, healthcare, patient safety, medical errors, and medication errors in the searching areas of title, keywords, abstract, and full text. Results: The preliminary search resulted in 68 articles. After a careful analysis of the content of each paper, a total of 33 papers was selected based on their relevancy. Conclusion: We should integrate RFID with hospital information systems (HIS and electronic health records (EHRs and support it by clinical decision support systems (CDSS, it facilitates processes and reduce medical, medication and diagnosis errors.

  10. Radio Frequency Identification (RFID) technology and patient safety

    Science.gov (United States)

    Ajami, Sima; Rajabzadeh, Ahmad

    2013-01-01

    Background: Radio frequency identification (RFID) systems have been successfully applied in areas of manufacturing, supply chain, agriculture, transportation, healthcare, and services to name a few. However, the different advantages and disadvantages expressed in various studies of the challenges facing the technology of the use of the RFID technology have been met with skepticism by managers of healthcare organizations. The aim of this study was to express and display the role of RFID technology in improving patient safety and increasing the impact of it in healthcare. Materials and Methods: This study was non-systematical review, which the literature search was conducted with the help of libraries, books, conference proceedings, PubMed databases and also search engines available at Google, Google scholar in which published between 2004 and 2013 during Febuary 2013. We employed the following keywords and their combinations; RFID, healthcare, patient safety, medical errors, and medication errors in the searching areas of title, keywords, abstract, and full text. Results: The preliminary search resulted in 68 articles. After a careful analysis of the content of each paper, a total of 33 papers was selected based on their relevancy. Conclusion: We should integrate RFID with hospital information systems (HIS) and electronic health records (EHRs) and support it by clinical decision support systems (CDSS), it facilitates processes and reduce medical, medication and diagnosis errors. PMID:24381626

  11. Detection of erosion/deposition depth using a low frequency passive Radio Frequency Identification (RFID) technology

    Science.gov (United States)

    Moustakidis, Iordanis Vlasios

    This thesis presents an experimental study both in the laboratory and field to develop and test a method for continuously measuring and monitoring scour using an automated identification technology known as Radio Frequency Identification (RFID). RFID systems consist of three main components, namely (a) the reader which controls the system, (b) the transponder (derived from transmitter/responder) that transmits data to the reader and (c) the excitation antenna that allows the communication between the reader and the transponder. The study provides an insight into the RFID technology and develops the framework for using this technology to eventually address two central themes in river mechanics and sediment transport; (a) the determination of the active layer thickness and (b) the scour/deposition depth around a hydraulic structure. In particular, this study develops the methodology for relating the signal strength of a radio frequency (RF) device with the distance between an excitation antenna and the RF device. The experiments presented herein are classified into two main groups, (1) the laboratory and (2) the RF signal vs. the detection distance experiments (field experiments). The laboratory experiments were designed to understand the effect of key RFID parameters (e.g., transponder orientation with respect to the excitation antenna plane, maximum antenna-transponder detection distance), measured in terms of the transponder return RF signal strength for various antenna-transponder distances, transponder orientations with respect to the excitation antenna plane and different mediums in between the excitation antenna and the transponder, on the overall performance of the RFID system. On the other hand, the RF signal vs. the detection distance experiments were based on the results obtained during the laboratory experiments and focused on developing calibration curves by relating the transponder return RF signal strength with the distance between the excitation

  12. Radio Frequency Identification (RFID) technology and patient safety

    National Research Council Canada - National Science Library

    Ajami, Sima; Rajabzadeh, Ahmad

    2013-01-01

    .... However, the different advantages and disadvantages expressed in various studies of the challenges facing the technology of the use of the RFID technology have been met with skepticism by managers...

  13. Offshore windfarm connection with low frequency AC transmission technology

    DEFF Research Database (Denmark)

    Qin, Nan; Xu, Zhao; You, Shi

    2009-01-01

    This paper investigates the feasibility of using the low frequency AC transmission (LFAC) system, e.g. fraction of 50 Hz or 60 Hz, for connecting the large offshore wind farm to the grid by modelling and simulation. The LFAC system improves the transmission capacity and distance compared to the c...... to the reduced inductive reactance of the grid. Moreover, the harmonics introduced by the frequency converter may require extra filters to be installed in such system....

  14. Biomedical Monitoring by a Novel Noncontact Radio Frequency Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This technology will be a quantum advance in cardiac monitoring and will be applicable in numerous situations such as for immediate assessment and monitoring of...

  15. Radio frequency power sensor based on MEMS technology

    NARCIS (Netherlands)

    Fernandez, L.J.; Visser, Eelke; Sesé, J.; Wiegerink, Remco J.; Jansen, Henricus V.; Flokstra, Jan; Flokstra, Jakob; Elwenspoek, Michael Curt

    2003-01-01

    We present the first measurement results of a power sensor for radio frequency (rf) signals (50 kHz - 40 GHz) with almost no dissipation during the measurement. This sensor is, therefore, a 'through' power sensor, that means that the rf signal is available during the measurement of its power. The

  16. The Current Awareness of Radio Frequency Identification Technology

    Science.gov (United States)

    Janák, Erik

    2012-12-01

    The article can be divided into two constituent parts. In the first part is introduced the RFID reference model, which categorizes RFID applications into eight groups. In the second part are thereafter presented the results of the survey of the use of information and communication technologies in Slovak enterprises, which was conducted by the Slovak Statistical Office, as well as the results of own questionnaire survey, which was aimed to determine the level of current awareness of RFID use in Slovakia.

  17. Radar activities of the DFVLR Institute for Radio Frequency Technology

    Science.gov (United States)

    Keydel, W.

    1983-01-01

    Aerospace research and the respective applications microwave tasks with respect to remote sensing, position finding and communication are discussed. The radar activities are directed at point targets, area targets and volume targets; they center around signature research for earth and ocean remote sensing, target recognition, reconnaissance and camouflage and imaging and area observation radar techniques (SAR and SLAR). The radar activities cover a frequency range from 1 GHz up to 94 GHz. The radar program is oriented to four possible application levels: ground, air, shuttle orbits and satellite orbits. Ground based studies and measurements, airborne scatterometers and imaging radars, a space shuttle radar, the MRSE, and follow on experiments are considered.

  18. Radar activities of the DFVLR Institute for Radio Frequency Technology

    Science.gov (United States)

    Keydel, W.

    1983-01-01

    Aerospace research and the respective applications microwave tasks with respect to remote sensing, position finding and communication are discussed. The radar activities are directed at point targets, area targets and volume targets; they center around signature research for earth and ocean remote sensing, target recognition, reconnaissance and camouflage and imaging and area observation radar techniques (SAR and SLAR). The radar activities cover a frequency range from 1 GHz up to 94 GHz. The radar program is oriented to four possible application levels: ground, air, shuttle orbits and satellite orbits. Ground based studies and measurements, airborne scatterometers and imaging radars, a space shuttle radar, the MRSE, and follow on experiments are considered.

  19. Arm Robot Surveillance Using Dual Tone Multiple Frequency Technology

    Directory of Open Access Journals (Sweden)

    Amrutha.V

    2014-09-01

    Full Text Available Surveillance place a pivotal role in addressing a wide range of security challenges .In the present paper we propose a Dual Tone Multiple Frequency ( DTMF based Robot with video surveillance. In the proposed model a DTMF based Robot with video surveillance with multiple key functions, Arm picker and security system was implemented. Master and slave concept using 3 Microcontroller and motor driver IC to drive motors was implemented and belt wheel platform was used to move the robot from one place to another. Multiple key functions were used to perform more functions and a camera for surveillance .The robot can navigate with the help of the user.

  20. Applying radio-frequency identification (RFID) technology in transfusion medicine.

    Science.gov (United States)

    Hohberger, Clive; Davis, Rodeina; Briggs, Lynne; Gutierrez, Alfonso; Veeramani, Dhamaraj

    2012-05-01

    ISO/IEC 18000-3 mode 1 standard 13.56 MHz RFID tags have been accepted by the International Society for Blood Transfusion (ISBT) and the United States Food and Drug Administration (FDA) as data carriers to integrate with and augment ISBT 128 barcode data carried on blood products. The use of 13.56 MHz RFID carrying ISBT 128 data structures allows the global deployment and use of RFID, supporting both international transfer of blood and international disaster relief. The deployment in process at the BloodCenter of Wisconsin and testing at the University of Iowa Health Center is the first FDA-permitted implementation of RFID throughout in all phases of blood banking, donation through transfusion. RFID technology and equipment selection will be discussed along with FDA-required RF safety testing; integration with the blood enterprise computing system and required RFID tag performance. Tag design and survivability is an issue due to blood bag centrifugation and irradiation. Deployment issues will be discussed. Use of RFID results in significant return on investment over the use of barcodes in the blood center operations through labor savings and error reduction. Copyright © 2011 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  1. Radio frequency identification (RFID technology for academic, logistics and passenger transport applications

    Directory of Open Access Journals (Sweden)

    John Jairo Ramírez Echeverry

    2012-12-01

    Full Text Available Radio frequency identification (RFID technology, from its beginning in the 1980s, has provided solutions in areas in which no identification (ID technology has done so before.  This paper presents three applications in areas having an issue in common: an RFID technology-based solution; these fields were academic topics, logistic support for an event and passenger land transport. Each project identified a problem which needed resolving, the methods and electronic devices used for such solution and the outcomes achieved. The developments shown in this paper indicated the multidisciplinary nature of RFID technology because it achieved new solutions for identifying objects or people in many contexts and not just the consumer goods trade which is the application nowadays most known for using this technology. These projects were developed by members of the Universidad Nacional de Colombia’s High Frequency Electronics and Telecommunications Research Group (CMUN (website: www.cmun.unal.edu.co.

  2. Challenges and opportunities of silent commerce - applying Radio Frequency Identification technology

    Directory of Open Access Journals (Sweden)

    Teuta Cata

    2006-04-01

    Full Text Available This research paper investigates applications of Radio Frequency Technology (RFID as an application of ubiquitous commerce. RFID has a wide application in the supply chain but still is very limited for customer support. This study introduces the concept of the Silent CRM (s-CRM which is an application of RFID to proactively support customer needs. Challenges of RFID application within companies, outside of companies and about the technology itself are discussed as well.

  3. Extremely high frequency (EHF) satellite communications (SATCOM) technology-transmitters and receivers

    Science.gov (United States)

    Raue, Jorg E.

    1983-10-01

    During the past three years, interest in satellite communications in the frequency bands above Ku-band has expanded dramatically. As a result, a number of key technology developments, targeted to meet specific next generation spaceborne needs, were undertaken. The state-of-the-art in solid state power transmitters and low noise receivers, including critical passive component technology, is presented. This includes filters as well as a series of rugged high performance ferrite components such as isolators, circulators and latching switches.

  4. Applying the Multisim Technology to Teach the Course of High Frequency Power Amplifier

    Science.gov (United States)

    Lv, Gang; Xue, Yuan-Sheng

    2011-01-01

    As one important professional base course in the electric information specialty, the course of "high frequency electronic circuit" has strong theoretical characteristic and abstract content. To enhance the teaching quality of this course, the computer simulation technology based on Multisim is introduced into the teaching of "high…

  5. Design of Miniature Patch Antenna Around the Frequency 3.5 GHz for WIMAX Technology

    Directory of Open Access Journals (Sweden)

    Adnane Latif

    2012-01-01

    Full Text Available This work aims to study a miniature rectangular patch antenna and#955; / 8 fed by coaxial probe with the transmission line method (TLM. The design and simulation of this antenna is around the frequency of 3.5GHz, for WIMAX technology. The results obtained (input impedance, reflection coefficient, VSWR and bandwidth are given by the program in the software MATLAB.

  6. Radio frequency for particle accelerators: evolution and anatomy of a technology

    CERN Document Server

    Vretenar, M

    2011-01-01

    This introductory lecture outlines the impressive progress of radio frequency technology, from the first table-top equipment to the present gigantic installations. The outcome of 83 years of evolution is subsequently submitted to an anatomical analysis, which allows identifying the main components of a modern RF system and their interrelations.

  7. Theory modeling and experimental research of external-cavity frequency doubling technology of short pulse laser

    Science.gov (United States)

    Duan, Cun-li; Zhang, Su-juan; He, Jiang-long

    2011-06-01

    Q-switched Short pulse laser has been widely applied in many fields, such as optical ranging, remote sensing, communications, nonlinear optics and spectroscopy etc. Q-switched Nd3+: YAG laser, with its high thermal conductivity and resistance to damage threshold, longer energy levels were generally used especially. Second harmonics generation was usually obtained through optical nonlinear effects in crystal. To the frequency doubling technology, poor conversion efficiency and multi-output frequency are the main problems. Researchers focus more on phase and group velocity matching induced by nonlinear effects, but pays less attention on theoretical modeling and numerical calculation of factors affecting frequency doubling of pulsed laser. In this article, nonlinear effects of double frequency crystals in Q-switched Nd3+: YAG laser was first analyzed in theory, then we deduced the relation expressions between factors affecting the efficiency of frequency doubling( thickness of frequency doubling crystal, cross section area of incident beam, power of the fundamental field, phase matching of incidence light)and double frequency efficiency. Secondly, taken KTP Crystal for example; numerical results and theirs' corresponding curves on these relation expressions was calculated and drawn with MATLAB software. These findings can be used for processing the specific requests of frequency doubling crystal. Finally, Theory modeling and numerical calculation were tested in experiment. The experiment results are in good agreement with those obtained in theory.

  8. The Cubesat Radiometer Radio Frequency Interference Technology Validation (CubeRRT) Mission

    Science.gov (United States)

    Misra, S.; Johnson, J. T.; Ball, C.; Chen, C. C.; Smith, G.; McKelvey, C.; Andrews, M.; O'Brien, A.; Kocz, J.; Jarnot, R.; Brown, S. T.; Piepmeier, J. R.; Lucey, J.; Miles, L. R.; Bradley, D.; Mohammed, P.

    2016-12-01

    Passive microwave measurements made below 40GHz have experienced increased amounts of man-made radio frequency interference (RFI) over the past couple of decades. Such RFI has had a degenerative impact on various important geophysical retrievals such as soil-moisture, sea-surface salinity, atmospheric water vapor, precipitation etc. The commercial demand for spectrum allocation has increased over the past couple of years - infringing on frequencies traditionally reserved for scientific uses such as Earth observation at passive microwave frequencies. With the current trend in shared spectrum allocations, future microwave radiometers will have to co-exist with terrestrial RFI sources. The CubeSat Radiometer Radio Frequency Interference Technology Validation (CubeRRT) mission is developing a 6U Cubesat system to demonstrate RFI detection and filtering technologies for future microwave radiometer remote sensing missions. CubeRRT will operate between 6-40GHz, and demonstrate on-board real-time RFI detection on Earth brightness temperatures tuned over 1GHz steps. The expected launch date for CubeRRT is early 2018. Digital subsystems for higher frequency microwave radiometry require a larger bandwidth, as well as more processing power and on-board operation capabilities for RFI filtering. Real-time and on-board RFI filtering technology development is critical for future missions to allow manageable downlink data volumes. The enabling CubeRRT technology is a digital FPGA-based spectrometer with a bandwidth of 1 GHz that is capable of implementing advanced RFI filtering algorithms that use the kurtosis and cross-frequency RFI detection methods in real-time on board the spacecraft. The CubeRRT payload consists of 3 subsystems: a wideband helical antenna, a tunable analog radiometer subsystem, and a digital backend. The following presentation will present an overview of the system and results from the latest integration and test.

  9. Wideband Monolithic Microwave Integrated Circuit Frequency Converters with GaAs mHEMT Technology

    DEFF Research Database (Denmark)

    Krozer, Viktor; Johansen, Tom Keinicke; Djurhuus, Torsten

    2005-01-01

    We present monolithic microwave integrated circuit (MMIC) frequency converter, which can be used for up and down conversion, due to the large RF and IF port bandwidth. The MMIC converters are based on commercially available GaAs mHEMT technology and are comprised of a Gilbert mixer cell core......, baluns and combiners. Single ended and balanced configurations DC and AC coupled have been investigated. The instantaneous 3 dB bandwidth at both the RF and the IF port of the frequency converters is ∼ 20 GHz with excellent amplitude and phase linearity. The predicted conversion gain is around 10 d...

  10. Evaluation of magnocellular pathway abnormalities in schizophrenia: a frequency doubling technology study and clinical implications

    Directory of Open Access Journals (Sweden)

    Fabiana Benites Vaz de Lima

    2013-04-01

    Full Text Available BACKGROUND: Visual processing deficits have been reported for patients with schizophrenia. Previous studies demonstrated differences in early-stage processing of schizophrenics, although the nature, extent, and localization of the disturbance are unknown. The magnocellular and parvocellular visual pathways are associated with transient and sustained channels, but their respective contributions to schizophrenia-related visual deficits remains controversial. PURPOSE: The aim of this study was to evaluate magnocellular dysfunction in schizophrenia using frequency doubling technology. METHODS: Thirty-one patients with schizophrenia and 34 healthy volunteers were examined. Frequency doubling technology testing was performed in one session, consisting of a 15-minute screening strategy followed by the C-20 program for frequency doubling technology. RESULTS: Schizophrenic patients showed lower global mean sensitivity (30,97 ± 2,25 dB compared with controls (32,17 ± 3,08 dB, p<0.009. Although there was no difference in the delta sensitivity of hemispheres, there was a difference in sensitivity analysis of the fibers crossing the optic chiasm, with lower mean sensitivity in the patient group (28,80 dB versus controls (30,66 dB. The difference was higher in fibers that do not cross the optic chiasm, with lower mean sensitivity in patients (27,61 dB versus controls (30,26 dB, p<0.005. CONCLUSIONS: Our results suggest that there are differences between global sensitivity and fiber sensitivity measured by frequency doubling technology. The different sensitivity of fibers that do not cross the optic chiasm is consistent with most current etiological hypotheses for schizophrenia. The decreased sensitivity responses in the optic radiations may significantly contribute to research assessing early-stage visual processing deficits for patients with schizophrenia.

  11. High performance superconducting radio frequency ingot niobium technology for continuous wave applications

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Pashupati, E-mail: dhakal@jlab.org; Ciovati, Gianluigi, E-mail: gciovati@jlab.org; Myneni, Ganapati R., E-mail: rao@jlab.org [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

    2015-12-04

    Future continuous wave (CW) accelerators require the superconducting radio frequency cavities with high quality factor and medium accelerating gradients (≤20 MV/m). Ingot niobium cavities with medium purity fulfill the specifications of both accelerating gradient and high quality factor with simple processing techniques and potential reduction in cost. This contribution reviews the current superconducting radiofrequency research and development and outlines the potential benefits of using ingot niobium technology for CW applications.

  12. Critical parameters affecting the design of high frequency transmission lines in standard CMOS technology

    KAUST Repository

    Al-Attar, Talal

    2017-05-13

    Different structures of transmission lines were designed and fabricated in standard CMOS technology to estimate some critical parameters including the RMS value of the surface roughness and the loss tangent. The input impedances for frequencies up to 50 GHz were modeled and compared with measurements. The results demonstrated a strong correlation between the used model with the proposed coefficients and the measured results, attesting the robustness of the model and the reliability of the incorporated coefficients values.

  13. Development of scalable frequency and power Phase-Locked Loop in 130nm CMOS technology

    CERN Document Server

    Firlej, M; Idzik, M; Moron, J; Swientek, K

    2014-01-01

    The design and measurements results of a prototype very low power Phase-Locked Loop (PLL) ASIC for applications in readout systems of particle physics detectors are presented. The PLL was fabricated in 130 nm CMOS technology. It was designed and simulated for frequency range 10 MHz–3.5 GHz. Four division factors i.e. 6, 8, 10 and 16 were implemented in the PLL feedback loop. The main PLL block-voltage controlled oscillator (VCO) should work in 16 frequency ranges/modes, switched either manually or automatically. Preliminary measurements done in frequency range 20 MHz–1.6 GHz showed that the ASIC is functional and generates proper clock signal. The automatic VCO mode switching, one of the main design goals, was positively verified. Power consumption of around 0.6mW was measured at 1 GHz for a division factor equal to 10.

  14. Dual-frequency grating method based research on phase measurement profilometry (PMP) technology

    Science.gov (United States)

    Wang, Binbin; Liang, Yijun; Deng, Hu

    2014-11-01

    With more than three decades of development, three-dimensional optical measurement technology has reached a mature stage in commercial applications, meanwhile new ones have continually arisen. Due to the development of Charge Coupled Device (CCD) array camera and digital projection technology, the applications of Phase Measurement Profilometry (PMP) become more and more broad. Among these, dual-frequency grating method has drawn many attentions because of its simplicity in principle and optical path, low requirement of equipment, high accuracy and level of automation comparing with other methods. The phase calculation is one of the key technologies in PMP. However, phase unwrapping algorithm in PMP is a difficult issue. A lot of new algorithm have been proposed, but neither one can solve all the problems, so how to set up new phase unwrapping algorithm becomes urgent. In this chapter, we systematically investigate the phase unwrapping method in dual-frequency grating method, and experimentally set up the system. To verify our method, we experimentally measure a three dimensional object which possesses complicated stair shapes on its surface. The results show that our dual-frequency grating method could achieve phase unwrapping without doing conventional phase unwrapping calculations, and it could also detect the detailed stair shapes on the surface of this three dimensional object automatically.

  15. The Engineering Development Array: A Low Frequency Radio Telescope Utilising SKA Precursor Technology

    Science.gov (United States)

    Wayth, Randall; Sokolowski, Marcin; Booler, Tom; Crosse, Brian; Emrich, David; Grootjans, Robert; Hall, Peter J.; Horsley, Luke; Juswardy, Budi; Kenney, David; Steele, Kim; Sutinjo, Adrian; Tingay, Steven J.; Ung, Daniel; Walker, Mia; Williams, Andrew; Beardsley, A.; Franzen, T. M. O.; Johnston-Hollitt, M.; Kaplan, D. L.; Morales, M. F.; Pallot, D.; Trott, C. M.; Wu, C.

    2017-08-01

    We describe the design and performance of the Engineering Development Array, which is a low-frequency radio telescope comprising 256 dual-polarisation dipole antennas working as a phased array. The Engineering Development Array was conceived of, developed, and deployed in just 18 months via re-use of Square Kilometre Array precursor technology and expertise, specifically from the Murchison Widefield Array radio telescope. Using drift scans and a model for the sky brightness temperature at low frequencies, we have derived the Engineering Development Array's receiver temperature as a function of frequency. The Engineering Development Array is shown to be sky-noise limited over most of the frequency range measured between 60 and 240 MHz. By using the Engineering Development Array in interferometric mode with the Murchison Widefield Array, we used calibrated visibilities to measure the absolute sensitivity of the array. The measured array sensitivity matches very well with a model based on the array layout and measured receiver temperature. The results demonstrate the practicality and feasibility of using Murchison Widefield Array-style precursor technology for Square Kilometre Array-scale stations. The modular architecture of the Engineering Development Array allows upgrades to the array to be rolled out in a staged approach. Future improvements to the Engineering Development Array include replacing the second stage beamformer with a fully digital system, and to transition to using RF-over-fibre for the signal output from first stage beamformers.

  16. A low-frequency versatile wireless power transfer technology for biomedical implants.

    Science.gov (United States)

    Jiang, Hao; Zhang, Junmin; Lan, Di; Chao; Liou, Shyshenq; Shahnasser, Hamid; Fechter, Richard; Hirose, Shinjiro; Harrison, Michael; Roy, Shuvo

    2013-08-01

    Implantable biomedical sensors and actuators are highly desired in modern medicine. In many cases, the implant's electrical power source profoundly determines its overall size and performance . The inductively coupled coil pair operating at the radio-frequency (RF) has been the primary method for wirelessly delivering electrical power to implants for the last three decades . Recent designs significantly improve the power delivery efficiency by optimizing the operating frequency, coil size and coil distance . However, RF radiation hazard and tissue absorption are the concerns in the RF wireless power transfer technology (RF-WPTT) , . Also, it requires an accurate impedance matching network that is sensitive to operating environments between the receiving coil and the load for efficient power delivery . In this paper, a novel low-frequency wireless power transfer technology (LF-WPTT) using rotating rare-earth permanent magnets is demonstrated. The LF-WPTT is able to deliver 2.967 W power at  ∼ 180 Hz to an 117.1 Ω resistor over 1 cm distance with 50% overall efficiency. Because of the low operating frequency, RF radiation hazard and tissue absorption are largely avoided, and the power delivery efficiency from the receiving coil to the load is independent of the operating environment. Also, there is little power loss observed in the LF-WPTT when the receiving coil is enclosed by non-magnetic implant-grade stainless steel.

  17. Power supply and impedance matching to drive technological radio-frequency plasmas with customized voltage waveforms.

    Science.gov (United States)

    Franek, James; Brandt, Steven; Berger, Birk; Liese, Martin; Barthel, Matthias; Schüngel, Edmund; Schulze, Julian

    2015-05-01

    We present a novel radio-frequency (RF) power supply and impedance matching to drive technological plasmas with customized voltage waveforms. It is based on a system of phase-locked RF generators that output single frequency voltage waveforms corresponding to multiple consecutive harmonics of a fundamental frequency. These signals are matched individually and combined to drive a RF plasma. Electrical filters are used to prevent parasitic interactions between the matching branches. By adjusting the harmonics' phases and voltage amplitudes individually, any voltage waveform can be approximated as a customized finite Fourier series. This RF supply system is easily adaptable to any technological plasma for industrial applications and allows the commercial utilization of process optimization based on voltage waveform tailoring for the first time. Here, this system is tested on a capacitive discharge based on three consecutive harmonics of 13.56 MHz. According to the Electrical Asymmetry Effect, tuning the phases between the applied harmonics results in an electrical control of the DC self-bias and the mean ion energy at almost constant ion flux. A comparison with the reference case of an electrically asymmetric dual-frequency discharge reveals that the control range of the mean ion energy can be significantly enlarged by using more than two consecutive harmonics.

  18. The relationship between technology acceptance and frequency of mobile commerce use amongst Generation Y consumers

    Directory of Open Access Journals (Sweden)

    Nobukhosi Dlodlo

    2013-02-01

    Full Text Available Orientation: The South African mobile commerce industry has realised an exponential growth in the past few years, yet the Generation Y market segment has failed to keep pace with this growth.Research purpose: To examine the nature of the relationships that exist between technology acceptance and frequency of mobile commerce usage amongst Generation Y consumers.Motivation for the study: The Generation Y cohort has emerged as an important age-group due to its economic contribution to the economy. It is therefore essential that their attitudes and behaviour continue to receive empirical introspection, particularly since mobile commerce has gathered momentum as an important and arguably, the most popular medium for commercial transactions. In a global space that is technology based, it becomes imperative to investigate the interplay between mobile commerce acceptance dimensions and frequency of use amongst Generation Ys.Research design, approach and method: A survey was conducted with the aid of a structured self-administered questionnaire with a view to collecting primary data from a sample consisting of 204 Generation Y consumers.Main findings: There were positive correlations between frequency of use and five mobile commerce acceptance dimensions. Cronbach Alpha values ranged between 0.714 and 0.898, thereby indicating high internal consistency amongst the subscales as well as within the entire survey instrument. Correlation coefficients ranged between 0.164 and 0.677 at both the p < 0.01 and p < 0.05 significance levels (2-tailed test, indicating very high levels of association amongst the subscales. Predictive validity of the five subscales and the variable frequency of use resulted in positive and statistically-significant results that were established at an adjusted R2 value of 0.674.Practical/managerial implications: Marketers and business practitioners are presented with practical insights into dimensions that enhance frequency of use of

  19. A 1V Phase Frequency Detector (PFD with 180nm CMOS Technology

    Directory of Open Access Journals (Sweden)

    N . K . Kaphungkui

    2013-02-01

    Full Text Available In this paper, designing of a Phase frequency detector with 180nm CMOS technology is presented. The main objective of the designed circuit is to reduce the power dissipation with a low voltage supply of 1V. Phase frequency detector has a wide range of applications but one of the main application is in modern day phased locked loop, it serve as a main building block. PFD (Phase Frequency Detector is a circuit that measures the phase and frequency difference between two signals, and has two outputs UP and DOWN which are signalled according to the phase and frequency difference of the two input signals. The designed circuit shows a satisfactory result with the low supply voltage. The detection of phase difference occurs only at the rising edge of the two clock signal. The total power dissipation from the circuit is only 3.88uW which is considerably low. In the field of IC design power dissipation of the circuit is always an important factor. The lower the power dissipation the longer the service time of the battery powered electronics circuit

  20. Frequency and amplitude dependences of molding accuracy in ultrasonic nanoimprint technology

    Science.gov (United States)

    Mekaru, Harutaka; Takahashi, Masaharu

    2009-12-01

    We use neither a heater nor ultraviolet lights, and are researching and developing an ultrasonic nanoimprint as a new nano-patterning technology. In our ultrasonic nanoimprint technology, ultrasonic vibration is not used as a heat generator instead of the heater. A mold is connected with an ultrasonic generator, and mold patterns are pushed down and pulled up at a high speed into a thermoplastic. Frictional heat is generated by ultrasonic vibration between mold patterns and thermoplastic patterns formed by an initial contact force. However, because frictional heat occurs locally, the whole mold is not heated. Therefore, a molding material can be comprehensively processed at room temperature. A magnetostriction actuator was built into our ultrasonic nanoimprint system as an ultrasonic generator, and the frequency and amplitude can be changed between dc-10 kHz and 0-4 µm, respectively. First, the ultrasonic nanoimprint was experimented by using this system on polyethylene terephthalate (PET, Tg = 69 °C), whose the glass transition temperature (Tg) is comparatively low in engineering plastics, and it was ascertained that the most suitable elastic material for this technique was an ethyl urethane rubber. In addition, we used a changeable frequency of the magnetostriction actuator, and nano-patterns in an electroformed-Ni mold were transferred to a 0.5 mm thick sheet of PET, polymethylmethacrylate (PMMA) and polycarbonate (PC), which are typical engineering plastics, under variable molding conditions. The frequency and amplitude dependence of ultrasonic vibration to the molding accuracy were investigated by measuring depth and width of imprinted patterns. As a result, regardless of the molding material, the imprinted depth was changed drastically when the frequency exceeded 5 kHz. On the other hand, when the amplitude of ultrasonic vibration grew, the imprinted depth gradually deepened. Influence of the frequency and amplitude of ultrasonic vibration was not observed

  1. A Stretchable Radio-Frequency Strain Sensor Using Screen Printing Technology

    Directory of Open Access Journals (Sweden)

    Heijun Jeong

    2016-11-01

    Full Text Available In this paper, we propose a stretchable radio-frequency (RF strain sensor fabricated with screen printing technology. The RF sensor is designed using a half-wavelength patch that resonates at 3.7 GHz. The resonant frequency is determined by the length of the patch, and it therefore changes when the patch is stretched. Polydimethylsiloxane (PDMS is used to create the substrate, because of its stretchable and screen-printable surface. In addition, Dupont PE872 (Dupont, NC, American silver conductive ink is used to create the stretchable conductive patterns. The sensor performance is demonstrated both with full-wave simulations and with measurements carried out on a fabricated sample. When the length of the patch sensor is increased by a 7.8% stretch, the resonant frequency decreases from 3.7 GHz to 3.43 GHz, evidencing a sensitivity of 3.43 × 107 Hz/%. Stretching the patch along its width does not change the resonant frequency.

  2. Low-cost, smartphone based frequency doubling technology visual field testing using virtual reality (Conference Presentation)

    Science.gov (United States)

    Alawa, Karam A.; Sayed, Mohamed; Arboleda, Alejandro; Durkee, Heather A.; Aguilar, Mariela C.; Lee, Richard K.

    2017-02-01

    Glaucoma is the leading cause of irreversible blindness worldwide. Due to its wide prevalence, effective screening tools are necessary. The purpose of this project is to design and evaluate a system that enables portable, cost effective, smartphone based visual field screening based on frequency doubling technology. The system is comprised of an Android smartphone to display frequency doubling stimuli and handle processing, a Bluetooth remote for user input, and a virtual reality headset to simulate the exam. The LG Nexus 5 smartphone and BoboVR Z3 virtual reality headset were used for their screen size and lens configuration, respectively. The system is capable of running the C-20, N-30, 24-2, and 30-2 testing patterns. Unlike the existing system, the smartphone FDT tests both eyes concurrently by showing the same background to both eyes but only displaying the stimulus to one eye at a time. Both the Humphrey Zeiss FDT and the smartphone FDT were tested on five subjects without a history of ocular disease with the C-20 testing pattern. The smartphone FDT successfully produced frequency doubling stimuli at the correct spatial and temporal frequency. Subjects could not tell which eye was being tested. All five subjects preferred the smartphone FDT to the Humphrey Zeiss FDT due to comfort and ease of use. The smartphone FDT is a low-cost, portable visual field screening device that can be used as a screening tool for glaucoma.

  3. An intelligent health monitoring system using radio-frequency identification technology.

    Science.gov (United States)

    Lai, Yeong-Lin; Chen, Chin-Ling; Chang, Ching-Hisang; Hsu, Chih-Yu; Lai, Yeong-Kang; Tseng, Kuo-Kun; Chen, Chih-Cheng; Zheng, Chun-Yi

    2015-01-01

    Long-term care (LTC) for the elderly has become extremely important in recent years. It is necessary for the different physiological monitoring systems to be integrated on the same interface to help oversee and manage the elderly's needs. This paper presents a novel health monitoring system for LTC services using radio-frequency identification (RFID) technology. Dual-band RFID protocols were included in the system, in which the high-frequency (HF) band of 13.56 MHz was used to identify individuals and the microwave band of 2.45 GHz was used to monitor physiological information. Distinct physiological data, including oxyhemoglobin saturation by pulse oximetry (SpO2), blood pressure, blood sugar, electrocardiogram (ECG) readings, body temperature, and respiration rate, were monitored by various biosensors. The intelligent RFID health monitoring system provided the features of the real-time acquisition of biomedical signals and the identification of personal information pertaining to the elderly and patients in nursing homes.

  4. Impact of radio-frequency identification (RFID) technologies on the hospital supply chain: a literature review.

    Science.gov (United States)

    Coustasse, Alberto; Tomblin, Shane; Slack, Chelsea

    2013-01-01

    Supply costs account for more than one-third of the average operating budget and constitute the second largest expenditure in hospitals. As hospitals have sought to reduce these costs, radio-frequency identification (RFID) technology has emerged as a solution. This study reviews existing literature to gauge the recent and potential impact and direction of the implementation of RFID in the hospital supply chain to determine current benefits and barriers of adoption. Findings show that the application of RFID to medical equipment and supplies tracking has resulted in efficiency increases in hospitals with lower costs and increased service quality. RFID technology can reduce costs, improve patient safety, and improve supply chain management effectiveness by increasing the ability to track and locate equipment, as well as monitoring theft prevention, distribution management, and patient billing. Despite ongoing RFID implementation in the hospital supply chain, barriers to widespread and rapid adoption include significant total expenditures, unclear return on investment, and competition with other strategic imperatives.

  5. Neural Modeling of High-Frequency Forward Transmission Coefficient for HEMT and FinFET Technologies

    Directory of Open Access Journals (Sweden)

    Zlatica Marinković

    2011-12-01

    Full Text Available This paper is devoted to examining the ability of artificial neural networks to model the forward transmission coefficient, which represents an important figure of merit for microwave transistors. This analysis is carried out for two different on-wafer devices, namely GaAs HEMT and Si FinFET. As far as the HEMT technology is concerned, the model is developed for three devices which differ in gate width. For the FinFET technology, the model is determined not only for the whole device but also for the actual transistor by using the de-embedding procedure to subtract the effects of pads, transmission lines, and substrate from the measurements. The obtained models have been developed and validated in a wide range of bias conditions for a frequency range up to 50 GHz.

  6. Fully Integrated, Miniature, High-Frequency Flow Probe Utilizing MEMS Leadless SOI Technology

    Science.gov (United States)

    Ned, Alex; Kurtz, Anthony; Shang, Tonghuo; Goodman, Scott; Giemette. Gera (d)

    2013-01-01

    This work focused on developing, fabricating, and fully calibrating a flowangle probe for aeronautics research by utilizing the latest microelectromechanical systems (MEMS), leadless silicon on insulator (SOI) sensor technology. While the concept of angle probes is not new, traditional devices had been relatively large due to fabrication constraints; often too large to resolve flow structures necessary for modern aeropropulsion measurements such as inlet flow distortions and vortices, secondary flows, etc. Mea surements of this kind demanded a new approach to probe design to achieve sizes on the order of 0.1 in. (.3 mm) diameter or smaller, and capable of meeting demanding requirements for accuracy and ruggedness. This approach invoked the use of stateof- the-art processing techniques to install SOI sensor chips directly onto the probe body, thus eliminating redundancy in sensor packaging and probe installation that have historically forced larger probe size. This also facilitated a better thermal match between the chip and its mount, improving stability and accuracy. Further, the leadless sensor technology with which the SOI sensing element is fabricated allows direct mounting and electrical interconnecting of the sensor to the probe body. This leadless technology allowed a rugged wire-out approach that is performed at the sensor length scale, thus achieving substantial sensor size reductions. The technology is inherently capable of high-frequency and high-accuracy performance in high temperatures and harsh environments.

  7. 78 FR 49529 - Radio Frequency Wireless Technology in Medical Devices; Guidance for Industry and Food and Drug...

    Science.gov (United States)

    2013-08-14

    ... of RF energy, and the RF wireless emissions from one product or device could potentially affect the... HUMAN SERVICES Food and Drug Administration (formerly Docket No. 2006D-0504) Radio Frequency Wireless...) is announcing the availability of the guidance entitled ``Radio Frequency Wireless Technology in...

  8. A novel method for fabricating curved frequency selective surface via 3D printing technology

    Science.gov (United States)

    Liang, Fengchao; Gao, Jinsong

    2014-12-01

    A novel method for fabricating curved frequency selective surfaces with undevelopable curved shape using 3D printing technology was proposed in this paper. First, FSS composed of Y slotted elements that adapt to 0° ~ 70 ° incidences was designed. Then, the 3D model of the curved FSS was created in a 3D modeling software. Next, the 3D model was digitalized into stl format file and then the stl file was inputted into a stereo lithography 3D printer. Next, the prototype of the curved FSS was fabricated by the 3D printer layer by layer. Finally, a 10 μm thick aluminum film was coated on the outer surface of the prototype of the curved FSS by a vacuum coater. The transmission performance of the metallised curved FSS was tested using free space method. It was shown that frequency selection characteristic of the metallised curved FSS reached the requirements of simulation design. The pass-band was in the Ku-band and the transmission rate on center frequency was 63% for nose cone incident direction. This method provides a new way to apply the FSS to arbitrary curved electromagnetic window.

  9. OPTIMUM RESOLUTION OF PHASE FREQUENCY DETECTOR BY CMOS TECHNOLOGY FOR PLL

    Directory of Open Access Journals (Sweden)

    B.Y. Vinay Kumar

    2015-12-01

    Full Text Available One of the nonlinear components in PLL is Phase Frequency Detector (PFD,the purpose is to compare two input frequencies in terms of their phase and frequency. In this process jitter will be introduced to the PLL system by PFD. proposed PFD is the preferred approach for detecting weak signals as from a deep space profile. The increase of MOS devices on a single chip will consume more power. Various applications of the PLL such as wireless communication systems, digital circuits, and receivers, targets optimum PFD Design. Optimized PFD reduces jitter effect on PLL and enhances the performance of PLL by increasing the locking range, reducing the phase error variance, reducing the acquisition time and reducing the power consumption. The power consumption in the design of PFD is dependent on CMOS logic of the gates In this paper we propose CMOS PFD, where the performance of the result will be analyzed by using Tanner EDA Tool by considering 45nm technology.

  10. Radio Frequency Identification (RFID) and communication technologies for solid waste bin and truck monitoring system.

    Science.gov (United States)

    Hannan, M A; Arebey, Maher; Begum, R A; Basri, Hassan

    2011-12-01

    This paper deals with a system of integration of Radio Frequency Identification (RFID) and communication technologies for solid waste bin and truck monitoring system. RFID, GPS, GPRS and GIS along with camera technologies have been integrated and developed the bin and truck intelligent monitoring system. A new kind of integrated theoretical framework, hardware architecture and interface algorithm has been introduced between the technologies for the successful implementation of the proposed system. In this system, bin and truck database have been developed such a way that the information of bin and truck ID, date and time of waste collection, bin status, amount of waste and bin and truck GPS coordinates etc. are complied and stored for monitoring and management activities. The results showed that the real-time image processing, histogram analysis, waste estimation and other bin information have been displayed in the GUI of the monitoring system. The real-time test and experimental results showed that the performance of the developed system was stable and satisfied the monitoring system with high practicability and validity.

  11. Evaluation of current literature to determine the potential effects of radio frequency identification on technology used in diabetes care.

    Science.gov (United States)

    Christe, Barbara

    2009-03-01

    This article examines recently published studies exploring the impact of radio frequency identification (RFID) systems on the technology involved in patient care. The conclusions will be extrapolated to include insulin delivery devices. Background material will also be presented to support examination of the variables involved in electromagnetic fields and potential interference from these RFID systems. (c) 2009 Diabetes Technology Society.

  12. Characterizing the performance of waveguide technologies for microwave-frequency quantum communication

    Science.gov (United States)

    Kurpiers, Philipp; Frey, Tobias; Wallraff, Andreas

    In circuit quantum electrodynamics (QED) systems quantum communication over distances beyond chip-scale requires low-loss waveguides. We measure the loss per unit length and the phase stability of commercially available waveguide technologies down to Millikelvin temperatures and single photon levels. More specifically, we characterize the frequency dependent attenuation and dispersion properties of a range of semi-rigid microwave cables and waveguides. We study the properties of various, commonly used conducting and dielectric materials with high accuracy in resonant structures to extract the internal quality factor which is inversely proportional to the loss per unit length. Furthermore, we compare our data with corresponding loss models. The results of our characterization are relevant to applications in which quantum communication is needed between nodes of a small network, e.g. between quantum circuits realized on different chips within the same or in distinct cryogenic systems.

  13. Influence of aspheric intraocular lens on frequency doubling technology and contrast sensitivity: a fellow eye study

    Directory of Open Access Journals (Sweden)

    Rodrigo França de Espíndola

    2014-12-01

    Full Text Available Purpose: To evaluate whether implantation of an aspheric intraocular lens (IOL results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery and, therefore, changes on frequency-doubling technology (FDT testing. Methods: The present prospective clinical study enrolled 25 patients with bilateral cataract (50 eyes, who randomly received either an aspheric (Akreos AO or a spherical (Akreos Fit IOL in one eye and the other IOL in the second eye. Assessment 12 months postoperatively included photopic and mesopic contrast sensitivity testing. Higher-order aberrations (HOAs were computed. FDT testing was divided into four areas to evaluate the variation of the values at different points. The median values of the local pattern thresholds (median area contrast sensitivity [MACS] obtained with that division were calculated. Results: The Akreos AO group obtained statistically significantly lower values of HOAs and spherical aberration compared with the Akreos Fit group. There was a statistically significant between-group difference in contrast sensitivity under mesopic conditions at all spatial frequencies. No statistically significant differences were observed in mean deviation and pattern standard deviation. The aspheric IOL exhibited higher MACS in all areas, although a statistically significant difference was reached only in the 20-degree field area (P=0.043. Conclusion: Aspheric IOLs significantly reduced spherical aberration and HOAs, improving mesopic contrast sensitivity. Although there was a trend toward slightly improved FDT in the aspheric IOL group, it was not statistically significant.

  14. Low-complexity prediction of frequency-rich biosignals for lossless compression in wearable technologies.

    Science.gov (United States)

    Guangwei Chen; Bowyer, Stuart A; Rodriguez-Villegas, Esther

    2016-08-01

    Wearable technologies that store, monitor and analyse a range of biosignals are an area of significant growth and interest for both industry and academia. The rate of data generation in these devices poses a considerable challenge with regards to the bandwidths of wireless transmission protocols, local storage capacities and the on-board power consumption requirements. This issue is particularly acute for frequency-rich biosignals containing significant higher frequency components that are un-served by conventional compression techniques. This paper proposes a low-complexity predictor, based on a low-order infinite impulse response bandpass filter, to accurately predict such biosignals for use in lossless compression. Experimental evaluation of the method demonstrates that it outperforms conventional predictors with an average 25 % reduction in predictor residual standard deviation. The predictor described here enables high-bandwidth wearable sensors that can be employed in systems with reduced power consumption for transmission, storage and compression leading to considerable improvements in user experience by reducing device mass and increasing battery life.

  15. Impact of Radio-Frequency Identification (RFID) Technologies on the Hospital Supply Chain: A Literature Review

    Science.gov (United States)

    Coustasse, Alberto; Tomblin, Shane; Slack, Chelsea

    2013-01-01

    Supply costs account for more than one-third of the average operating budget and constitute the second largest expenditure in hospitals. As hospitals have sought to reduce these costs, radio-frequency identification (RFID) technology has emerged as a solution. This study reviews existing literature to gauge the recent and potential impact and direction of the implementation of RFID in the hospital supply chain to determine current benefits and barriers of adoption. Findings show that the application of RFID to medical equipment and supplies tracking has resulted in efficiency increases in hospitals with lower costs and increased service quality. RFID technology can reduce costs, improve patient safety, and improve supply chain management effectiveness by increasing the ability to track and locate equipment, as well as monitoring theft prevention, distribution management, and patient billing. Despite ongoing RFID implementation in the hospital supply chain, barriers to widespread and rapid adoption include significant total expenditures, unclear return on investment, and competition with other strategic imperatives. PMID:24159272

  16. Applications for radio-frequency identification technology in the perioperative setting.

    Science.gov (United States)

    Zhao, Tiyu; Zhang, Xiaoxiang; Zeng, Lili; Xia, Shuyan; Hinton, Antentor Othrell; Li, Xiuyun

    2014-06-01

    We implemented a two-year project to develop a security-gated management system for the perioperative setting using radio-frequency identification (RFID) technology to enhance the management efficiency of the OR. We installed RFID readers beside the entrances to the OR and changing areas to receive and process signals from the RFID tags that we sewed into surgical scrub attire and shoes. The system also required integrating automatic access control panels, computerized lockers, light-emitting diode (LED) information screens, wireless networks, and an information system. By doing this, we are able to control the flow of personnel and materials more effectively, reduce OR costs, optimize the registration and attire-changing process for personnel, and improve management efficiency. We also anticipate this system will improve patient safety by reducing the risk of surgical site infection. Application of security-gated management systems is an important and effective way to help ensure a clean, convenient, and safe management process to manage costs in the perioperative area and promote patient safety. Copyright © 2014 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  17. The potential implementation of radio-frequency identification technology for personal health examination and monitoring.

    Science.gov (United States)

    Nguyen, Andrew

    2009-11-16

    This paper presents several possible applications of the radio-frequency identification (RFID) technology for personal health examination and monitoring. One application involves using RFID sensors external to the human body, while another one uses both internal and external RFID sensors. Another application involves simultaneous assessment and monitoring of many patients in a hospital setting using networks of RFID sensors. All the assessment and monitoring are done wirelessly, either continuously or periodically in any interval, in which the sensors collect information on human parts such as the lungs or heart and transmit this information to a router, PC or PDA device connected to the internet, from which patient's condition can be diagnosed and viewed by authorized medical professionals in remote locations. Instantaneous information allows medical professionals to intervene properly and in a timely fashion to prevent possible catastrophic effects to patients. The continuously assessed and monitored information provides medical professionals with more complete and long-term studies of patients. The proposed ideas promise to result in not only enhancement of the health treatment quality but also in significant reduction of medical expenditure.

  18. Learning effect of humphrey matrix frequency doubling technology perimetry in patients with ocular hypertension.

    Science.gov (United States)

    Centofanti, Marco; Fogagnolo, Paolo; Oddone, Francesco; Orzalesi, Nicola; Vetrugno, Michele; Manni, Gianluca; Rossetti, Luca

    2008-09-01

    To evaluate the learning effect of Frequency Doubling Technology (FDT) perimetry using the Humphrey Matrix-FDT perimetry (Matrix) 24-2 full-threshold program on patients with ocular hypertension experienced with standard automated perimetry. Twenty-four patients with ocular hypertension underwent 5 full-threshold Matrix tests at intervals of 5+/-2 days. Learning effect was defined as an improvement at results for duration, perimetric indices, foveal sensitivity, Glaucoma Hemifield Test, and the number of points with a Plearning effect. Test-retest variability was also calculated for each repetition as the mean of the point-to-point interindividual standard deviations. A learning effect was demonstrated for mean defect (P=0.031, analysis of variance) and foveal sensitivity (P=0.009) and it only affected the first test for both parameters. All the other parameters did not show any significant learning effect. The effect was independent from eccentricity and quadrant or hemifield sensitivities. The results of this study demonstrate that the learning effect for Matrix-FDT is mild and it may affect only the first test. Caution is needed in the analysis of the first Matrix-FDT examination and retest may be advisable in the presence of low mean defect.

  19. Quantitatively analyzing dielectrical properties of resins and mapping permittivity variations in CFRP with high-frequency eddy current device technology

    Science.gov (United States)

    Gäbler, Simone; Heuer, Henning; Heinrich, Gert; Kupke, Richard

    2015-03-01

    Eddy current testing is well-established for non-destructive characterization of electrical conductive materials. The development of high-frequency eddy current technology (with frequency ranges up to 100 MHz) made it even possible to extend the classical fields of application towards less conductive materials like CFRP. Maxwell's equations and recent research show that the use of high-frequency eddy current technology is also suitable for non-conductive materials. In that case the change of complex impedance of the probing coil contains information on sample permittivity. This paper shows that even a quantitative measurement of complex permittivity with high-frequency eddy current device technology is possible using an appropriate calibration. Measurement accuracy is comparable to commercial capacitive dielectric analyzers. If the sample material is electrically conductive, both, permittivity and conductivity influence the complex impedance measured with high-frequency eddy current devices. Depending on the measurement setup and the sheet resistance of the sample a parallel characterization of both parameters is possible on isotropic multi-layer materials. On CFRP the permittivity measurement is much more complex due to the capacitive effects between the carbon rovings. However, first results show that at least the local permittivity variations (like those caused by thermal damages) are detectable.

  20. Combining Frequency Doubling Technology Perimetry and Scanning Laser Polarimetry for Glaucoma Detection.

    Science.gov (United States)

    Mwanza, Jean-Claude; Warren, Joshua L; Hochberg, Jessica T; Budenz, Donald L; Chang, Robert T; Ramulu, Pradeep Y

    2015-01-01

    To determine the ability of frequency doubling technology (FDT) and scanning laser polarimetry with variable corneal compensation (GDx-VCC) to detect glaucoma when used individually and in combination. One hundred ten normal and 114 glaucomatous subjects were tested with FDT C-20-5 screening protocol and the GDx-VCC. The discriminating ability was tested for each device individually and for both devices combined using GDx-NFI, GDx-TSNIT, number of missed points of FDT, and normal or abnormal FDT. Measures of discrimination included sensitivity, specificity, area under the curve (AUC), Akaike's information criterion (AIC), and prediction confidence interval lengths. For detecting glaucoma regardless of severity, the multivariable model resulting from the combination of GDx-TSNIT, number of abnormal points on FDT (NAP-FDT), and the interaction GDx-TSNIT×NAP-FDT (AIC: 88.28, AUC: 0.959, sensitivity: 94.6%, specificity: 89.5%) outperformed the best single-variable model provided by GDx-NFI (AIC: 120.88, AUC: 0.914, sensitivity: 87.8%, specificity: 84.2%). The multivariable model combining GDx-TSNIT, NAP-FDT, and interaction GDx-TSNIT×NAP-FDT consistently provided better discriminating abilities for detecting early, moderate, and severe glaucoma than the best single-variable models. The multivariable model including GDx-TSNIT, NAP-FDT, and the interaction GDx-TSNIT×NAP-FDT provides the best glaucoma prediction compared with all other multivariable and univariable models. Combining the FDT C-20-5 screening protocol and GDx-VCC improves glaucoma detection compared with using GDx or FDT alone.

  1. INTENSIFICATION OF PRODUCTION YOGURT TECHNOLOGY WITH ACTIVATION OF THE LEAVEN WITH THE ELECTROMAGNETIC FIELD OF LOW FREQUENCY

    Directory of Open Access Journals (Sweden)

    Karikurubu J.

    2015-04-01

    Full Text Available In Russia, as well as in foreign practice, classic yogurts are more required. Depending on the value of imported dry starters, the proposed technology allowing reduction in their quantities in yogurt technology is very crucial. It will affect the cost of the finished products. In yogurt technology, the possibility of using physical techniques, with the purpose of intensifying the process of producing yogurt, is very little reflected. Pre-activation of the leaven by electromagnetic field – lower frequency before fermenting in the production of yogurt is one of the technological tricks that speed up the fermenting process and reduce the quantity of starters. The advantage of the proposed technology is its ease of implementation, not requiring additional cost of electricity and also enhanced maximum reduction of additional chemicals which are used as raw materials to create a special environment for the growth of microorganisms belonging to the leaven. In this work, the overview of the existing principles for accelerating the fermentation process of milk is given. In this work, the research results of accelerating technology of fermenting milk for yogurt are presented. Mathematical process of experimental data enables the optimization, fermentation process using leaven FD-DVS YF-L812 10Yo-Flex. The optimal temperature and duration for the maximum acceleration of the process of obtaining yogurt at a given frequency of electromagnetic field are identified. We have given organoleptic characteristics of yoghurt prepared using the activated ferment

  2. Meta-analysis of the diagnostic efficiency of frequency-doubling technology for primary glaucoma

    Institute of Scientific and Technical Information of China (English)

    LIU Ting; HE Xiangge

    2007-01-01

    The overall diagnostic capabilities and utility of frequency-doubling technology (FDT) in patients with primary glaucoma,which was diagnosed by standard automated perimetry (SAP) and/or optic disc appearance as the gold standard,were assessed.A comprehensive electric retrieval in MEDLINE,EMBASE,Cochrane Library,BIOSIS,Previews,HMIC,IPA,OVID,CNKI,CBMdisc,VIP information,CMCC,CCPD,SSreader,21dmedia and manual retrieval in related textbooks,journals,congress articles and their references at home and abroad were performed to identify relevant articles in English or Chinese.The corresponding references were retrieved by means of electric retrieval and manual retrieval from different databases or materials.Criteria for inclusion or exclusion were established according to validity criteria for diagnostic studies published by the Cochrane Methods Group on Screening and Diagnostic Tests.The quality of the included articles was then assessed and characteristics were extracted.Statistical analysis was performed with Meta Test version 0.6 software to test the heterogeneity of the included articles.The appropriate effects model was selected to calculate pooled weighted sensitivity and specificity.Summary receiver operating characteristic (SROC)curve was drawn and the area under the curve (AUC)was calculated.Finally,sensitivity analysis was performed.Twenty-one studies out of 206 retrieved articles were included,with a total of 3172 patients.The reported sensitivity of FDT ranged from 0.51 to 1.00,and specificity from 0.58 to 1.00.The pooled weighted sensitivity and specificity of FDT with 95% confidence intervals (95% CI) after correction for standard error were 0.86 (0.80-0.90) and 0.87 (0.81-0.91),respectively.The AUC of SROC was 93.01%.Sensitivity analysis demonstrated no disproportionate influences of individual studies.The included articles are of good quality and FDT can be a highly efficient diagnostic test for primary glaucoma based on Meta-analysis.

  3. Improvement of the Mirror Extending in Empirical Mode Decomposition Method and the Technology for Eliminating Frequency Mixing

    Institute of Scientific and Technical Information of China (English)

    赵进平

    2002-01-01

    The mirror extending approach proposed by Zhao and Huang 9in EMD method is improved in this paper.Mirror extending manner of data is kept unchanged, but the approach for determining nvelopes is changed. When the end of data is obvio usly not extremum, the envelope is determined by the first inner extremum and the image value in the mirror, ignoring the value on the end. This improvement eliminates the frequency compression near the end and decreases the error.Meanwhile,tridiagonal equations are used and the calculation speed is much increase d.Thetemporal process curve is more important in reflecting the real physical process and comparablewithotherp henomena.Frequency mixing in IMFs makes it impossible.A highfrequencyreconstruction (HFR)approach is proposed to eli minate common frequency mixing and reconstruct an IMF with all high fr equency portions.By this approach, the IMFs without frequency mixing are obtain ed to express significative processes.The high frequency information restored in high frequency IMF can be extracted by general spectrum method. After obtainin g IMFs by EMD method, some of the theoretical and technological issues still exi st w hen using the IMFs.The consistency of IMFs with real physical process is discus sed in detail.By virtue of the approach proposed in this paper,the EMD method can be widely used in various fields.

  4. Balanced G-band Gm-boosted frequency doublers in transferred substrate InP HBT technology

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Thualfiqar, Al-Sawaf; Weimann, Nils

    2016-01-01

    In this paper, balanced G-band Gm-boosted frequency doublers in transferred substrate (TS) InP HBT technology are reported for the first time. The Gm-boosted frequency doublers consist of a phase compensated Marchand balun, Gm-boosted doubler stage, and an optional cascode gain stage at the output....... The doubler without cascode demonstrates a maximum output power of +4.7 dBm around a narrow frequency range at 200 GHz when driven with an input power of +10 dBm. A Gm-boosted frequency doubler with cascode demonstrates an output power of +5.4 dBm at 190 GHz when driven with an input power of +11 d......Bm. The power consumptions of the Gm-boosted frequency doubler without and with cascode are 30.9 mW and 56.4 mW, respectively. The fundamental suppression for both doublers remains better than 17.3 dB over an input frequency range of 75–110 GHz....

  5. Performance Analysis of Variation in Power Consumption and Frequency on Different Topologies of Ring VCO in 70 nm CMOS Technology

    Directory of Open Access Journals (Sweden)

    Sumant Katiyal

    2012-07-01

    Full Text Available The proposed work describes the performance evaluation ofdifferent types of ring oscillator Voltage Controlled Oscillatortopologies on the basis of two characteristic parameters powerand frequency in 70 nm CMOS technology. The varioustopologies analyzed include Current Starved VCO, VCO withGates of PMOS Transistor Grounded, VCO with PMOS DiodeConnected, VCO with NMOS Diode Connected, VCO withvoltage applied to both PMOS and NMOS Transistor.Simulation of different parameters of ring oscillator VCO iscarried out on Tanner tool Version 13. VCO topologies areevaluated on the basis of frequency and power consumption bytaking lower supply voltage of 1.2 V. Performance evaluationand comparison of different topologies results in minimumpower consumption of 0.57 uW by Current Starved VCOtopology and maximum operating frequency of 0.57 MHz byVCO with Gates of PMOS Transistor Grounded.

  6. Integrated optical frequency shifter in silicon-organic hybrid (SOH) technology.

    Science.gov (United States)

    Lauermann, M; Weimann, C; Knopf, A; Heni, W; Palmer, R; Koeber, S; Elder, D L; Bogaerts, W; Leuthold, J; Dalton, L R; Rembe, C; Freude, W; Koos, C

    2016-05-30

    We demonstrate for the first time a waveguide-based frequency shifter on the silicon photonic platform using single-sideband modulation. The device is based on silicon-organic hybrid (SOH) electro-optic modulators, which combine conventional silicon-on-insulator waveguides with highly efficient electro-optic cladding materials. Using small-signal modulation, we demonstrate frequency shifts of up to 10 GHz. We further show large-signal modulation with optimized waveforms, enabling a conversion efficiency of -5.8 dB while suppressing spurious side-modes by more than 23 dB. In contrast to conventional acousto-optic frequency shifters, our devices lend themselves to large-scale integration on silicon substrates, while enabling frequency shifts that are several orders of magnitude larger than those demonstrated with all-silicon serrodyne devices.

  7. Frequency Regulation Strategies in Grid Integrated Offshore Wind Turbines via VSC-HVDC Technology: A Review

    Directory of Open Access Journals (Sweden)

    Jafar Jallad

    2017-08-01

    Full Text Available The inclusion of wind energy in a power system network is currently seeing a significant increase. However, this inclusion has resulted in degradation of the inertia response, which in turn seriously affects the stability of the power system’s frequency. This problem can be solved by using an active power reserve to stabilize the frequency within an allowable limit in the event of a sudden load increment or the loss of generators. Active power reserves can be utilized via three approaches: (1 de-loading method (pitching or over-speeding by a variable speed wind turbine (VSWT; (2 stored energy in the capacitors of voltage source converter-high voltage direct current (VSC-HVDC transmission; and (3 coordination of frequency regulation between the offshore wind farms and the VSC-HVDC transmission. This paper reviews the solutions that can be used to overcome problems related to the frequency stability of grid- integrated offshore wind turbines. It also details the permanent magnet synchronous generator (PMSG with full-scale back to back (B2B converters, its corresponding control strategies, and a typical VSC-HVDC system with an associated control system. The control methods, both on the levels of a wind turbine and the VSC-HVDC system that participate in a system’s primary frequency control and emulation inertia, are discussed.

  8. Radio frequency identification (RFID) technologies for locating warehouse resources: A conceptual framework

    OpenAIRE

    Hassan, M; M Ali; Aktas, E

    2012-01-01

    Copyright @ 2012 Information Technology Society In the supply chain, a warehouse is a crucial component for linking all chain parties. It is necessary to track the real time resource location and status to support warehouse operations effectively. Therefore, RFID technology has been adopted to facilitate the collection and sharing of data in a warehouse environment. However, an essential decision should be made on the type of RFID tags the warehouse managers should adopt, because it is ver...

  9. Readiness of hospitals affiliated with Shiraz university of medical sciences for implementation of radio frequency identification technology

    Directory of Open Access Journals (Sweden)

    Saeid Ebrahimi

    2015-10-01

    Full Text Available Introduction: Applying information technology in healthcare system is one of the most important criteria of the World Health Organization for evaluating the quality of healthcare systems of different countries. Moreover, applying this technology in different parts of health care system can create great potentials for improving the quality of healthcare services. In this regard, Radio Frequency Identification (RFID technology is one of the most practical technologies in identifying and collecting data. The present study aimed to compare the readiness of Shiraz University of medical sciences hospitals for implementation of RFID system in 2014. Method: This was a cross-sectional study conducted in 2014. The research population consisted of 110 senior and middle managers. Due to the limited research population, census method was used. The research tool was a questionnaire prepared by the researcher to investigate the hospitals’ readiness for implementation of RFID technology. Face and content validity of the questionnaire were approved by the experts. Cronbach’s alpha test was run to determine the reliability of the questionnaire (data were considered significant at p <0.05. Also, the data were analyzed in SPSS software using descriptive statistics (mean, standard deviation, and percentage and inferential statistics (one-way ANOVA. Results: The study showed that the readiness level of the hospitals was moderate. Comparing the mean of the total readiness level in the hospitals under the study revealed that there was a statistically significant difference between hospital M and other hospitals (P=0.003. However, the total readiness of hospital I was higher than others. Conclusion: Among 13 hospitals under the study, the hospitals I and A were moderately ready and others were not ready for implementation of RFID technology. Thus, considering various applications and advantages of RFID technology, it is suggested that the hospitals should prepare

  10. INFLUENCE OF CONSTRUCTIVE AND TECHNOLOGICAL DEFECTS ON COAXIAL RADIO-FREQUENCY CABLE IMPEDANCE

    Directory of Open Access Journals (Sweden)

    G.V. Bezprozvannych

    2013-04-01

    Full Text Available Coaxial user's radio-frequency cables belong to a category of cable television network elements parameters of which essentially specify the system capabilities as a whole. The cable working frequency spectrum spreading to 1000 MHz along with digital television and soundtrack signals transmission and high-definition television introduction causes more rigid requirements for wave impedance and, consequently, for the cable design. The established norms on user's cable impedance deviations fail to answer the state-of-the-art requirements for granting a complex of interactive services. On the basis of calculations performed, values of internal and external conductor diameters deviations as well as dielectric permeability of the insulation material are validated. For up-to-date user's radio-frequency cables, the impedance deviation from the normalized average value of 75 Ohm should not exceed ± 2 Ohm.

  11. Design and Fabrication of Nanoscale IDTs Using Electron Beam Technology for High-Frequency SAW Devices

    Directory of Open Access Journals (Sweden)

    Wei-Che Shih

    2014-01-01

    Full Text Available High-frequency Rayleigh-mode surface acoustic wave (SAW devices were fabricated for 4G mobile telecommunications. The RF magnetron sputtering method was adopted to grow piezoelectric aluminum nitride (AlN thin films on the Si3N4/Si substrates. The influence of sputtering parameters on the crystalline characteristics of AlN thin films was investigated. The interdigital transducer electrodes (IDTs of aluminum (Al were then fabricated onto the AlN surfaces by using the electron beam (e-beam direct write lithography method to form the Al/AlN/Si3N4/Si structured SAW devices. The Al electrodes were adopted owing to its low resistivity, low cost, and low density of the material. For 4G applications in mobile telecommunications, the line widths of 937 nm, 750 nm, 562 nm, and 375 nm of IDTs were designed. Preferred orientation and crystalline properties of AlN thin films were determined by X-ray diffraction using a Siemens XRD-8 with CuKα radiation. Additionally, the cross-sectional images of AlN thin films were obtained by scanning electron microscope. Finally, the frequency responses of high-frequency SAW devices were measured using the E5071C network analyzer. The center frequencies of the high-frequency Rayleigh-mode SAW devices of 1.36 GHz, 1.81 GHz, 2.37 GHz, and 3.74 GHz are obtained. This study demonstrates that the proposed processing method significantly contributes to high-frequency SAW devices for wireless communications.

  12. Novel infrared image enhancement technology based on the frequency compensation approach

    Science.gov (United States)

    Qi, Yuhua; He, Rulong; Lin, Haitao

    2016-05-01

    A novel infrared image enhancement method has been proposed in this paper. Our aim is to develop a detail enhancement method which is focused on the frequency feature of the image. The proposed method is following the most popular strategy of enhancing the infrared images nowadays, but concentrating on the frequency domain. Firstly, the original image is separated by a guided image filter into detail layer and the base layer. Quite unlike the traditional methods, we use the guided image filter to eliminate most of the noise and weak signal of the scenario. Then, by a designed iteration process, the higher frequency of the scenario will be calculated back and add to the detail layer. The noise will not be enhanced because the iteration is only focused on the leftover scenario frequency. We run many tests on the raw data captured by the 320 × 256 HgCdTe cooled thermal imager, and make a comparison between our approach with the previous method of bilateral filtering digital detail enhancement and guided image filtering digital detail enhancement. Figures and analytical data show that our method is better than the previous proposed researches. Our method could effectively process the infrared image with less noise and artifacts, which has potential applications in testing, manufacturing, chemical imaging, night vision, and surveillance security.

  13. Advantages of high-frequency Pulse-tube technology and its applications in infrared sensing

    Science.gov (United States)

    Arts, R.; Willems, D.; Mullié, J.; Benschop, T.

    2016-05-01

    The low-frequency pulse-tube cryocooler has been a workhorse for large heat lift applications. However, the highfrequency pulse tube has to date not seen the widespread use in tactical infrared applications that Stirling cryocoolers have had, despite significant advantages in terms of exported vibrations and lifetime. Thales Cryogenics has produced large series of high-frequency pulse-tube cryocoolers for non-infrared applications since 2005. However, the use of Thales pulse-tube cryocoolers for infrared sensing has to date largely been limited to high-end space applications. In this paper, the performances of existing available off-the-shelf pulse-tube cryocoolers are examined versus typical tactical infrared requirements. A comparison is made on efficiency, power density, reliability, and cost. An outlook is given on future developments that could bring the pulse-tube into the mainstream for tactical infrared applications.

  14. E-Mentoring: Technology, Trust, and Frequency in Corporate E-Mentoring Relationships

    Science.gov (United States)

    Godwin, Shannon G.

    2011-01-01

    Electronic mentoring through asynchronous methods using technologies such as e-mail or the Internet is used in the education industry whereby undergraduate and graduate students can be matched with either university professors or career professionals. However, corporate organizations with mentoring initiatives predominantly use traditional…

  15. Improving the Quality and Cost of Healthcare Delivery: The Potential of Radio Frequency Identification (RFID) Technology

    Science.gov (United States)

    Vilamovska, Anna-Marie

    2010-01-01

    The study investigated whether an upcoming class of health information technology (HIT) can be used to address currently outstanding issues in the quality and cost of healthcare delivery. Expert interviews and a literature review were used to describe the 2009 universe of in- and outpatient healthcare RFID applications and to identify those…

  16. Numerical Modeling and the Technological Process of cleating at a Frequency of 500 Hz

    Directory of Open Access Journals (Sweden)

    Claudia Olimpia STASAC

    2009-10-01

    Full Text Available The paper refers to a technology ofachieving bimetallic combination by processingstructure in an electromagnetic field of mediumfrequency.The numerical model used in this study isbased on the finite element model and is destined tothe study of heating by induction in volume ofcyllindrical feromagnetic steel structure whoseproperties vary with temperature and suffer phasetransformation across Curie point.

  17. Improving the Quality and Cost of Healthcare Delivery: The Potential of Radio Frequency Identification (RFID) Technology

    Science.gov (United States)

    Vilamovska, Anna-Marie

    2010-01-01

    The study investigated whether an upcoming class of health information technology (HIT) can be used to address currently outstanding issues in the quality and cost of healthcare delivery. Expert interviews and a literature review were used to describe the 2009 universe of in- and outpatient healthcare RFID applications and to identify those…

  18. Science and Technology of Chemicals and Biological Sensing at Terahertz Frequencies

    Science.gov (United States)

    2007-11-02

    calibration standards. Moreover, for these original measurements, a mechanically- tuned Gunn diode source was used to drive the multiplier chain. There is...approximately a ±5° uncertainty in the phase measurements associated with use of this Gunn diode source and this uncertainty arises from frequency...R.M.Weikle, II, “Opening the Terahertz Window with Integrated Diode Circuits,” (invited) IEEE Journal of Solid-State Circuits, vol. 40, no. 10, pp. 2104

  19. Measuring coral size-frequency distribution using stereo video technology, a comparison with in situ measurements.

    Science.gov (United States)

    Turner, Joseph A; Polunin, Nicholas V C; Field, Stuart N; Wilson, Shaun K

    2015-05-01

    Coral colony size-frequency distribution data offer valuable information about the ecological status of coral reefs. Such data are usually collected by divers in situ, but stereo video is being increasingly used for monitoring benthic marine communities and may be used to collect size information for coral colonies. This study compared the size-frequency distributions of coral colonies obtained by divers measuring colonies 'in situ' with digital video imagery collected using stereo video and later processed using computer software. The size-frequency distributions of the two methods were similar for corymbose colonies, although distributions were different for massive, branching and all colonies combined. The differences are mainly driven by greater abundance of colonies >50 cm and fewer colonies 5 cm and was able to record measurements on 87% of the colonies detected. However, stereo video only detected 57% of marked colonies coral recruits. Estimates of colony size made with the stereo video were smaller than the in situ technique for all growth forms, particularly for massive morphologies. Despite differences in size distributions, community assessments, which incorporated genera, growth forms and size, were similar between the two techniques. Stereo video is suitable for monitoring coral community demographics and provided data similar to in situ measure for corymbose corals, but the ability to accurately measure massive and branching coral morphologies appeared to decline with increasing colony size.

  20. Introducing Discrete Frequency Infrared Technology for High-Throughput Biofluid Screening

    Science.gov (United States)

    Hughes, Caryn; Clemens, Graeme; Bird, Benjamin; Dawson, Timothy; Ashton, Katherine M.; Jenkinson, Michael D.; Brodbelt, Andrew; Weida, Miles; Fotheringham, Edeline; Barre, Matthew; Rowlette, Jeremy; Baker, Matthew J.

    2016-02-01

    Accurate early diagnosis is critical to patient survival, management and quality of life. Biofluids are key to early diagnosis due to their ease of collection and intimate involvement in human function. Large-scale mid-IR imaging of dried fluid deposits offers a high-throughput molecular analysis paradigm for the biomedical laboratory. The exciting advent of tuneable quantum cascade lasers allows for the collection of discrete frequency infrared data enabling clinically relevant timescales. By scanning targeted frequencies spectral quality, reproducibility and diagnostic potential can be maintained while significantly reducing acquisition time and processing requirements, sampling 16 serum spots with 0.6, 5.1 and 15% relative standard deviation (RSD) for 199, 14 and 9 discrete frequencies respectively. We use this reproducible methodology to show proof of concept rapid diagnostics; 40 unique dried liquid biopsies from brain, breast, lung and skin cancer patients were classified in 2.4 cumulative seconds against 10 non-cancer controls with accuracies of up to 90%.

  1. Study on technology of high-frequency pulsed magnetic field strength measurement.

    Science.gov (United States)

    Chen, Yi-Mei; Liu, Zhi-Peng; Yin, Tao

    2012-01-01

    High-frequency transient weak magnetic field is always involved in researches about biomedical engineering field while common magnetic-field sensors cannot work properly at frequencies as high as MHz. To measure the value of MHz-level weak pulsed magnetic-field strength accurately, this paper designs a measurement and calibration method for pulsed magnetic-field. In this paper, a device made of Nonferromagnetic material was independently designed and applied to pulsed magnetic field measurement. It held an accurately relative position between the magnetic field generating coil and the detecting coil. By applying a sinusoidal pulse to the generator, collecting the induced electromotive force of the detector, the final magnetic field strength was worked out through algorithms written in Matlab according to Faraday's Law. Experiments were carried out for measurement and calibration. Experiments showed that, under good stability and consistency, accurate measurement of magnetic-field strength of a sinepulse magnetic-field can be achieved, with frequency at 0.5, 1, 1.5 MHz and strength level at micro-Tesla. Calibration results carried out a measuring relative error about 2.5%.

  2. A Computational Method based on Radio Frequency Technologies for the Analysis of Accessibility of Disabled People in Sustainable Cities

    Directory of Open Access Journals (Sweden)

    Virgilio Gilart-Iglesias

    2015-11-01

    Full Text Available The sustainability strategy in urban spaces arises from reflecting on how to achieve a more habitable city and is materialized in a series of sustainable transformations aimed at humanizing different environments so that they can be used and enjoyed by everyone without exception and regardless of their ability. Modern communication technologies allow new opportunities to analyze efficiency in the use of urban spaces from several points of view: adequacy of facilities, usability, and social integration capabilities. The research presented in this paper proposes a method to perform an analysis of movement accessibility in sustainable cities based on radio frequency technologies and the ubiquitous computing possibilities of the new Internet of Things paradigm. The proposal can be deployed in both indoor and outdoor environments to check specific locations of a city. Finally, a case study in a controlled context has been simulated to validate the proposal as a pre-deployment step in urban environments.

  3. An investigation into the feasibility of locating portable medical devices using radio frequency identification devices and technology.

    Science.gov (United States)

    Britton, J

    2007-01-01

    Portable medical devices represent an important resource for assisting healthcare delivery. The movement of portable devices often results in them being unavailable when needed. Tracking equipment using radiofrequency identification technology/devices (RFID) may provide a promising solution to the problems encountered in locating portable equipment. An RFID technology trial was undertaken at Royal Alexandra Hospital, Paisley. This involved the temporary installation of three active readers and attaching actively transmitting radio frequency tags to different portable medical devices. The active readers and computer system were linked using a bespoke data network. Tags and readers from two separate manufacturers were tested. Reliability difficulties were encountered when testing the technology from the first manufacturer, probably due to the casing of the medical device interfering with the signal from the tag. Improved results were obtained when using equipment from the second manufacturer with an overall error rate of 12.3%. Tags from this manufacturer were specifically designed to overcome problems observed with the first system tested. Findings from this proof of concept trial suggest that RFID technology could be used to track the location of equipment in a hospital.

  4. MOSFET technologies for double-pole four-throw radio-frequency switch

    CERN Document Server

    Srivastava, Viranjay M

    2014-01-01

    This book provides analysis and discusses the design of various MOSFET technologies which are used for the design of Double-Pole Four-Throw (DP4T) RF switches for next generation communication systems. The authors discuss the design of the (DP4T) RF switch by using the Double-Gate (DG) MOSFET, as well as the Cylindrical Surrounding double-gate (CSDG) MOSFET.  The effect of HFO2 (high dielectric material) in the design of DG MOSFET and CSDG MOSFET  is also explored. Coverage includes comparison of Single-gate MOSFET and Double-gate MOSFET switching parameters, as well as testing of MOSFETs parameters using image acquisition.  ·         Provides a single-source reference to the latest technologies for the design of Double-gate MOSFET, Cylindrical Surrounding double-gate MOSFET and HFO2 based MOSFET; ·         Explains the design of RF switches using the technologies presented and simulates switches; ·         Verifies parameters and discusses feasibility of devices and switches.

  5. Microwave frequency detector at X-band using GaAs MMIC technology

    Institute of Scientific and Technical Information of China (English)

    Zhang Jun; Liao Xiaoping; Jiao Yongchang

    2009-01-01

    The design,fabrication,and experimental results of an MEMS microwave frequency detector are presented for the first time.The structure consists of a microwave power divider,two CPW transmission lines,a microwave power combiner,an MEMS capacitive power sensor and a thermopile.The detector has been designed and fabricated on GaAs substrate using the MMIC process at the X-band successfully.The MEMS capacitive power sensor is used for detecting the high power signal,while the thermopile is used for detecting the low power signal.Signals of 17 and 10 dBm are measured over the X-band.The sensitivity is 0.56 MHz/fF under 17 dBm by the capacitive power sensor,and 6.67 MHz//μV under 10 dBm by the thermopile.respectively.The validity of the presented design has been confirmed by the experiment.

  6. Measurement of sound velocity made easy using harmonic resonant frequencies with everyday mobile technology

    Science.gov (United States)

    Hirth, Michael; Kuhn, Jochen; Müller, Andreas

    2015-02-01

    Recent articles about smartphone experiments have described their applications as experimental tools in different physical contexts.1-4 They have established that smartphones facilitate experimental setups, thanks to the small size and diverse functions of mobile devices, in comparison to setups with computer-based measurements. In the experiment described in this article, the experimental setup is reduced to a minimum. The objective of the experiment is to determine the speed of sound with a high degree of accuracy using everyday tools. An article published recently proposes a time-of-flight method where sound or acoustic pulses are reflected at the ends of an open tube.5 In contrast, the following experiment idea is based on the harmonic resonant frequencies of such a tube, simultaneously triggered by a noise signal.

  7. Could the Pharmaceutical Industry Benefit from Full-Scale Adoption of Radio-Frequency Identification (RFID) Technology with New Regulations?

    Science.gov (United States)

    Coustasse, Alberto; Kimble, Craig A; Stanton, Robert B; Naylor, Mariah

    2016-01-01

    Healthcare regulators are directing attention to the pharmaceutical supply chain with the passage of the Drug Quality and Security Act (DQSA) and the Drug Supply Chain Security Act (DSCSA). Adoption of Radio-Frequency Identification (RFID) technology has the ability to improve compliance, reduce costs, and improve safety in the supply chain but its implementation has been limited; primarily because of hardware and tag costs. The purpose of this research study was to analyze the benefits to the pharmaceutical industry and healthcare system of the adoption of RFID technology as a result of newly implemented supply chain regulations. The methodology was a review following the steps of a systematic review with a total of 96 sources used. With the DSCSA, pharmaceutical companies must track and trace prescription drugs across the supply chain, and RFID can resolve many track-and-trace issues with manufacturer control of data. The practical implication of this study is that pharmaceutical companies must continue to have the potential to increase revenues, decrease associated costs, and increase compliance with new FDA regulations with RFID. Still, challenges related to regulatory statute wording, implementation of two-dimensional barcode technology, and the variety of interfaces within the pharmaceutical supply chain have delayed adoption and its full implementation.

  8. New technology based on clamping for high gradient radio frequency photogun

    Science.gov (United States)

    Alesini, David; Battisti, Antonio; Ferrario, Massimo; Foggetta, Luca; Lollo, Valerio; Ficcadenti, Luca; Pettinacci, Valerio; Custodio, Sean; Pirez, Eylene; Musumeci, Pietro; Palumbo, Luigi

    2015-09-01

    High gradient rf photoguns have been a key development to enable several applications of high quality electron beams. They allow the generation of beams with very high peak current and low transverse emittance, satisfying the tight demands for free-electron lasers, energy recovery linacs, Compton/Thomson sources and high-energy linear colliders. In the present paper we present the design of a new rf photogun recently developed in the framework of the SPARC_LAB photoinjector activities at the laboratories of the National Institute of Nuclear Physics in Frascati (LNF-INFN, Italy). This design implements several new features from the electromagnetic point of view and, more important, a novel technology for its realization that does not involve any brazing process. From the electromagnetic point of view the gun presents high mode separation, low peak surface electric field at the iris and minimized pulsed heating on the coupler. For the realization, we have implemented a novel fabrication design that, avoiding brazing, strongly reduces the cost, the realization time and the risk of failure. Details on the electromagnetic design, low power rf measurements and high power radiofrequency and beam tests performed at the University of California in Los Angeles (UCLA) are discussed in the paper.

  9. Effect of Radio Frequency Heating on Yoghurt, I: Technological Applicability, Shelf-Life and Sensorial Quality

    Science.gov (United States)

    Siefarth, Caroline; Tran, Thi Bich Thao; Mittermaier, Peter; Pfeiffer, Thomas; Buettner, Andrea

    2014-01-01

    This first part of a two-part study focuses on the technical feasibility of applying radio frequency (RF) heating at different temperatures (58, 65 and 72 °C) to a stirred yoghurt gel after culturing. For comparison, a convectional (CV) heating process was also applied. The aim was to increase the yoghurt shelf-life, by preventing post-acidification and the growth of yeasts and molds. At the same time, the viability of lactic acid bacteria (LAB) was investigated in view of existing legal regulations for yoghurts. Additionally, the yoghurt color, aroma and taste profiles were evaluated. It was found that the application of RF heating was effective for the rapid attainment of homogenous temperatures of 58 and 65 °C, respectively. For RF heating at 72 °C, it was not possible to establish a stable heating regime, since in some cases, there was significant overheating followed by strong contraction of the yoghurt curd and whey separation. Hence, it was decided not to continue with the RF heating series at 72 °C. In the case of CV heating, heat transfer limitations were observed, and prolonged heating was required. Nevertheless, we showed that yeasts and molds survived neither the RF nor CV heat treatment. LAB were found not to survive the CV treatment, but these beneficial microorganisms were still present in reduced numbers after RF heating to 58 and 65 °C. This important observation is most likely related to the mildness of RF treatment. While post-acidification was not observed on yoghurt storage, slight color changes occurred after heat treatment. The flavor and taste profiles were shown to be similar to the reference product. Furthermore, a trained sensory panel was not able to distinguish between, for example, the reference yoghurt and the RF 65 °C sample by triangular testing (α = 5%), showing the potential of novel strategies for further improvements of heat-treated yoghurt. PMID:28234322

  10. Thiamethoxam: Assessing flight activity of honeybees foraging on treated oilseed rape using radio frequency identification technology.

    Science.gov (United States)

    Thompson, Helen; Coulson, Mike; Ruddle, Natalie; Wilkins, Selwyn; Harkin, Sarah

    2016-02-01

    The present study was designed to assess homing behavior of bees foraging on winter oilseed rape grown from seed treated with thiamethoxam (as Cruiser OSR), with 1 field drilled with thiamethoxam-treated seed and 2 control fields drilled with fungicide-only-treated seed. Twelve honeybee colonies were used per treatment group, 4 each located at the field edge (on-field site), at approximately 500 m and 1000 m from the field. A total of nearly 300 newly emerged bees per colony were fitted (tagged) with Mic3 radio frequency identification (RFID) transponders and introduced into each of the 36 study hives. The RFID readers fitted to the entrances of the test colonies were used to monitor the activity of the tagged bees for the duration of the 5-wk flowering period of the crop. These activity data were analyzed to assess any impact on flight activity of bees foraging on the treated compared with untreated crops. Honeybees were seen to be actively foraging within all 3 treatment groups during the exposure period. The data for the more than 3000 RFID-tagged bees and more than 90 000 foraging flights monitored throughout the exposure phase for the study follow the same trends across the treatment and controls and at each of the 3 apiary distances, indicating that there were no effects from foraging on the treated crop. Under the experimental conditions, there was no effect of foraging on thiamethoxam-treated oilseed rape on honeybee flight activity or on their ability to return to the hive. © 2015 SETAC.

  11. Effect of Radio Frequency Heating on Yoghurt, I: Technological Applicability, Shelf-Life and Sensorial Quality

    Directory of Open Access Journals (Sweden)

    Caroline Siefarth

    2014-05-01

    Full Text Available This first part of a two-part study focuses on the technical feasibility of applying radio frequency (RF heating at different temperatures (58, 65 and 72 °C to a stirred yoghurt gel after culturing. For comparison, a convectional (CV heating process was also applied. The aim was to increase the yoghurt shelf-life, by preventing post-acidification and the growth of yeasts and molds. At the same time, the viability of lactic acid bacteria (LAB was investigated in view of existing legal regulations for yoghurts. Additionally, the yoghurt color, aroma and taste profiles were evaluated. It was found that the application of RF heating was effective for the rapid attainment of homogenous temperatures of 58 and 65 °C, respectively. For RF heating at 72 °C, it was not possible to establish a stable heating regime, since in some cases, there was significant overheating followed by strong contraction of the yoghurt curd and whey separation. Hence, it was decided not to continue with the RF heating series at 72 °C. In the case of CV heating, heat transfer limitations were observed, and prolonged heating was required. Nevertheless, we showed that yeasts and molds survived neither the RF nor CV heat treatment. LAB were found not to survive the CV treatment, but these beneficial microorganisms were still present in reduced numbers after RF heating to 58 and 65 °C. This important observation is most likely related to the mildness of RF treatment. While post-acidification was not observed on yoghurt storage, slight color changes occurred after heat treatment. The flavor and taste profiles were shown to be similar to the reference product. Furthermore, a trained sensory panel was not able to distinguish between, for example, the reference yoghurt and the RF 65 °C sample by triangular testing (α = 5%, showing the potential of novel strategies for further improvements of heat-treated yoghurt.

  12. Effect of Radio Frequency Heating on Yoghurt, I: Technological Applicability, Shelf-Life and Sensorial Quality.

    Science.gov (United States)

    Siefarth, Caroline; Tran, Thi Bich Thao; Mittermaier, Peter; Pfeiffer, Thomas; Buettner, Andrea

    2014-05-15

    This first part of a two-part study focuses on the technical feasibility of applying radio frequency (RF) heating at different temperatures (58, 65 and 72 °C) to a stirred yoghurt gel after culturing. For comparison, a convectional (CV) heating process was also applied. The aim was to increase the yoghurt shelf-life, by preventing post-acidification and the growth of yeasts and molds. At the same time, the viability of lactic acid bacteria (LAB) was investigated in view of existing legal regulations for yoghurts. Additionally, the yoghurt color, aroma and taste profiles were evaluated. It was found that the application of RF heating was effective for the rapid attainment of homogenous temperatures of 58 and 65 °C, respectively. For RF heating at 72 °C, it was not possible to establish a stable heating regime, since in some cases, there was significant overheating followed by strong contraction of the yoghurt curd and whey separation. Hence, it was decided not to continue with the RF heating series at 72 °C. In the case of CV heating, heat transfer limitations were observed, and prolonged heating was required. Nevertheless, we showed that yeasts and molds survived neither the RF nor CV heat treatment. LAB were found not to survive the CV treatment, but these beneficial microorganisms were still present in reduced numbers after RF heating to 58 and 65 °C. This important observation is most likely related to the mildness of RF treatment. While post-acidification was not observed on yoghurt storage, slight color changes occurred after heat treatment. The flavor and taste profiles were shown to be similar to the reference product. Furthermore, a trained sensory panel was not able to distinguish between, for example, the reference yoghurt and the RF 65 °C sample by triangular testing (α = 5%), showing the potential of novel strategies for further improvements of heat-treated yoghurt.

  13. A reusable robust radio frequency biosensor using microwave resonator by integrated passive device technology for quantitative detection of glucose level.

    Science.gov (United States)

    Kim, N Y; Dhakal, R; Adhikari, K K; Kim, E S; Wang, C

    2015-05-15

    A reusable robust radio frequency (RF) biosensor with a rectangular meandered line (RML) resonator on a gallium arsenide substrate by integrated passive device (IPD) technology was designed, fabricated and tested to enable the real-time identification of the glucose level in human serum. The air-bridge structure fabricated by an IPD technology was applied to the RML resonator to improve its sensitivity by increasing the magnitude of the return loss (S21). The resonance behaviour, based on S21 characteristics of the biosensor, was analysed at 9.20 GHz with human serum containing different glucose concentration ranging from 148-268 mg dl(-1), 105-225 mg dl(-1) and at a deionised (D) water glucose concentration in the range of 25- 500 mg dl(-1) for seven different samples. A calibration analysis was performed for the human serum from two different subjects and for D-glucose at a response time of 60 s; the reproducibility, the minimum shift in resonance frequency and the long-term stability of the signal were investigated. The feature characteristics based on the resonance concept after the use of serum as an analyte are modelled as an inductor, capacitor and resistor. The findings support the development of resonance-based sensing with an excellent sensitivity of 1.08 MHz per 1 mg dl(-1), a detection limit of 8.01 mg dl(-1), and a limit of quantisation of 24.30 mg dl(-1). Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  14. AN EMPIRICAL STUDY FOR RADIO FREQUENCY IDENTIFICATION (RFID ADOPTION BY SMEs IN THE TAIWANESE INFORMATION TECHNOLOGY (IT INDUSTRY

    Directory of Open Access Journals (Sweden)

    Hsin Chen

    2012-07-01

    Full Text Available Radio Frequency Identification (RFID technology represents a common standard for data storage and retrieval that could improve collaboration and data sharing between non-competing organisations. With the advent of RFID, organisations have the opportunity to rethink how their organisation will operate and integrate in the supply chain. Especially for Small to Medium Sized Enterprises (SMEs, that they have limited resources adopting such an innovative technology (i.e. RFID the adoption decision can be daunting. Literature indicates that SMEs that decide to go on with implementation have so far only a few guidelines from either private companies or public authorities regarding awareness on specific opportunities and risks. This research is therefore trying to explore in detail the factors that affect SMEs' RFID adoption in the Taiwan Information Technology (IT manufacturing industry. We are employing Exploratory Factor Analysis (EFA techniques and utilising a questionnaire survey in order to collect and analyse our data. After classifying the responding SMEs into three different adopters categories named ready adopter, initiator adopter and unprepared adopter using EFA technique our results show that each category has some specific adoption factors related to their unique situation. These are for ready adopters: cost and management, for initiator adopters: competitiveness and process efficiency and unprepared adopters: IT management difficulties, IT implementation difficulties and cost of implementation. A SMEs RFID adoption model is then proposed. It is anticipated that the findings of this research will not only enhance the research in RFID adoption in SMEs, but can also act as a reference for practitioners in the industry and researchers in the academic field.

  15. A wide range ultra-low power Phase-Locked Loop with automatic frequency setting in 130 nm CMOS technology for data serialisation

    Science.gov (United States)

    Firlej, M.; Fiutowski, T.; Idzik, M.; Moroń, J.; Świentek, K.

    2015-12-01

    The design and measurements results of a wide frequency range ultra-low power Phase-Locked Loop (PLL) for applications in readout systems of particle physics detectors are presented. The PLL was fabricated in a 130 nm CMOS technology. To allow the implementation of different data serialisation schemes multiple division factors (6, 8, 10, 16) were implemented in the PLL feedback loop. The main PLL block—VCO works in 16 frequency ranges/modes, switched either manually or automatically. A dedicated automatic frequency mode switching circuit was developed to allow simple frequency tuning. Although the PLL was designed and simulated for a frequency range of 30 MHz-3 GHz, due to the SLVS interface limits, the measurements were done only up to 1.3 GHz. The full PLL functionality was experimentally verified, confirming a very low and frequency scalable power consumption (0.7 mW at 1 GHz).

  16. Implementation of a Dual Containment/Surveillance System utilizing scene-change detection and radio frequency technology

    Energy Technology Data Exchange (ETDEWEB)

    FITZGERALD, ERIC; KOENIG, RICHARD

    2005-06-27

    This paper will examine the implementation of scene-change detection and radio frequency technology within a Dual Containment/Surveillance (C/S) System. Additionally, this paper will examine the human performance factors in the operation of these systems. Currently, Westinghouse Savannah River Company utilizes the Continuous Item Monitoring and Surveillance System (CIMS) in the performance of Dual C/S to monitor special nuclear materials within International Atomic Energy Agency (IAEA) Safeguards and Domestic Safeguards. CIMS is comprised of the Material Monitoring System (MMS) (R), a multi-media electronic surveillance system developed by Sandia National Laboratory which incorporates the use of active seals commonly called Radio Frequency Tamper Indicating Devices (RFTIDs), NT Vision (R) as developed by Los Alamos National Laboratory, a Microsoft Windows NT (R) based operating system providing for domestic scene-change detection and the Digital Multi-Camera Optical Surveillance System (DMOS) (R) which provides scene-change detection for IAEA. Although this paper will focus on the implementation of Dual C/S utilizing the Continuous Item Monitoring and Surveillance System, the necessity for a thorough review of Safeguards and Security requirements with organizations and personnel having minimal to no prior MPC&A training will also be covered. Successful Dual C/S implementation plans must consider not only system design and failure modes, but must also be accompanied with the appropriate ''mind shift'' within operations and technical personnel. This is required to ensure completion of both physical and electronic activities, and system design changes are performed conscientiously and with full awareness of MPC&A requirements.

  17. Multifocal and pattern-reversal visual evoked potentials vs. automated perimetry frequency-doubling technology matrix in optic neuritis

    Directory of Open Access Journals (Sweden)

    Marcella Nebbioso

    2013-01-01

    Full Text Available Background: To compare the usefulness of the traditional pattern-reversal Visual Evoked Potentials (VEP with multifocal VEP (mfVEP and Frequency-Doubling Technology (FDT perimetry in the evaluation of the ocular abnormalities induced by acute or subacute optic neuritis (ON. Materials and Methods: The test results of 24 ON patients were compared with those obtained in 40 normal control subjects. MfVEP recordings were obtained by using an Optoelectronic Stimulator that extracts topographic VEP using a pseudorandom m-sequence stimulus. Receiver operator characteristic (ROC curves were calculated to determine the sensitivity and specificity of abnormal values. Results: The frequency of the abnormal ocular findings differed in the ON patients according to the used technique. Reduced visual sensitivity was demonstrated in 12 eyes (54.5% using FDT perimetry; 17 eyes (77.2% showed decreased amplitude and/or an increase in the implicit time of the P1 wave in mfVEP and 20 eyes (90.9% showed an abnormal decrease in the amplitude and/or an increase in the latency of the P100 peak at VEP examination. The areas under the ROC curves ranged from 0.743 to 0.935, with VEP having the largest areas. The VEP and mfVEP amplitudes and latencies yielded the greatest sensitivity and specificity. Conclusions: The mfVEP and the FDT perimetry can be used for the evaluation and monitoring of visual impairment in patients with ON. The most sensitive and practical diagnostic tool in patients with ON is, however, the traditional VEP. The mfVEP can be utilized in those cases with doubtful or negative VEP results.

  18. In vivo histological evaluation of fractional ablative microplasma radio frequency technology using a roller tip: an animal study.

    Science.gov (United States)

    Li, Xiaodan; Fang, Lin; Huang, Luping

    2015-12-01

    The aim of the present study is to investigate the histological characteristics associated with microplasma radio frequency (MPRF) technology in an animal study using different treatment parameters. Two white piglets, aged 6 months, received MPRF treatment using a roller tip; the treatment site was located on the dorsal skin. Four groups of parameters were adopted regarding the performance of the treatment at four zones on the dorsum. Immediately, at 7 days and at 1, 3, and 6 months posttreatment, we observed the healing process and obtained specimens from each treatment zone. Hematoxylin and eosin and Masson stainings of histological sections were performed to assess the degree of tissue injury, the heat effect, the healing process, and neocollagenesis. Heat shock protein (HSP) was also detected using immunohistochemistry. The roller tip generated a fractional treatment, which had a general trend involving an increase in depth and width with increasing pulse energy and decreasing sliding speed. During the wound healing process, dermal neocollagenesis was stimulated, remodeled, and matured gradually. The expression of HSP47 and HPS72 was elevated in the dermis surrounding the microlesions after treatment; it peaked at 1 month posttreatment and became diffuse in the dermis. MPRF is a promising fractional skin resurfacing technique. The roller tip can be used with low risk in the entire treatment zone with rapid healing. An appropriate treatment regimen should be chosen to guarantee therapeutic efficacy and safety.

  19. Design of Antenna-on-Chip, Antenna-on-Package and Detectors from RF, Microwave to THz Frequency Range in SiGe-C Technology

    NARCIS (Netherlands)

    Wane, S; Bardy, S.; Heijster, R.M.E.M. van; Goulet, F.; Gamand, P.

    2011-01-01

    Design solutions for on-chip signal detectors, Antenna-on- Chip and Antenna-on-Package (with Bond Wire elements), from RF, Microwave to THz frequency range, using state-of-theart SiGe BiCMOS technology are presented. Both CML and CMOS detectors are designed, fabricated and compared in terms of their

  20. Analysis and Application of RFID Radio Frequency Technology in Libraries%RFID无线射频技术在图书馆的应用分析

    Institute of Scientific and Technical Information of China (English)

    陈海钦

    2011-01-01

    This paper describes the working principle of radio frequency RFID, and it' s application and significance of radio fi'equency RFID technology in the Library, By the means of electronic tags, the circulation of books, self-lending, security, inventory, retirement, shelves assortment, automatic sorting are all accomplished by RFID radio frequency identification technology which realizes the situation of the quick and easy self-service borrowing, reliable and ac- curate anti-theft system, fast stock counting, books looking up and shelves assortment. This paper makes the comparison of RFID technology and barcode technology, the advantages and disadvantages of several different frequency of RFID technology applied in the library, and it also refers the UHF radio frequency RFID technology applied in the children's library practically.%阐述了RFID无线射频技术的工作原理,以及RFID无线射频技术在图书馆的应用及意义,RFID无线射频识别技术使图书的借还、自助借阅、防盗、盘点、检索、整理书架、自动分拣均通过电子标签完成。真正实现了自助借阅的快捷方便,防盗系统的可靠准确和盘点、找书、整理书架的快速。对无线射频识别技术与条形码技术进行了比较,分析了几种不同频段的RFID技术在图书馆应用中的优缺点,介绍了超高频RFID无线射频技术在少年儿童图书馆的实际应用。

  1. Comparison of Standard Automated Perimetry, Short-Wavelength Automated Perimetry, and Frequency-Doubling Technology Perimetry to Monitor Glaucoma Progression.

    Science.gov (United States)

    Hu, Rongrong; Wang, Chenkun; Gu, Yangshun; Racette, Lyne

    2016-02-01

    Detection of progression is paramount to the clinical management of glaucoma. Our goal is to compare the performance of standard automated perimetry (SAP), short-wavelength automated perimetry (SWAP), and frequency-doubling technology (FDT) perimetry in monitoring glaucoma progression.Longitudinal data of paired SAP, SWAP, and FDT from 113 eyes with primary open-angle glaucoma enrolled in the Diagnostic Innovations in Glaucoma Study or the African Descent and Glaucoma Evaluation Study were included. Data from all tests were expressed in comparable units by converting the sensitivity from decibels to unitless contrast sensitivity and by expressing sensitivity values in percent of mean normal based on an independent dataset of 207 healthy eyes with aging deterioration taken into consideration. Pointwise linear regression analysis was performed and 3 criteria (conservative, moderate, and liberal) were used to define progression and improvement. Global mean sensitivity (MS) was fitted with linear mixed models.No statistically significant difference in the proportion of progressing and improving eyes was observed across tests using the conservative criterion. Fewer eyes showed improvement on SAP compared to SWAP and FDT using the moderate criterion; and FDT detected less progressing eyes than SAP and SWAP using the liberal criterion. The agreement between these test types was poor. The linear mixed model showed a progressing trend of global MS overtime for SAP and SWAP, but not for FDT. The baseline estimate of SWAP MS was significantly lower than SAP MS by 21.59% of mean normal. FDT showed comparable estimation of baseline MS with SAP.SWAP and FDT do not appear to have significant benefits over SAP in monitoring glaucoma progression. SAP, SWAP, and FDT may, however, detect progression in different glaucoma eyes.

  2. A system utilizing radio frequency identification (RFID) technology to monitor individual rodent behavior in complex social settings.

    Science.gov (United States)

    Howerton, Christopher L; Garner, Joseph P; Mench, Joy A

    2012-07-30

    Pre-clinical investigation of human CNS disorders relies heavily on mouse models. However these show low predictive validity for translational success to humans, partly due to the extensive use of rapid, high-throughput behavioral assays. Improved assays to monitor rodent behavior over longer time scales in a variety of contexts while still maintaining the efficiency of data collection associated with high-throughput assays are needed. We developed an apparatus that uses radio frequency identification device (RFID) technology to facilitate long-term automated monitoring of the behavior of mice in socially or structurally complex cage environments. Mice that were individually marked and implanted with transponders were placed in pairs in the apparatus, and their locations continuously tracked for 24 h. Video observation was used to validate the RFID readings. The apparatus and its associated software accurately tracked the locations of all mice, yielding information about each mouse's location over time, its diel activity patterns, and the amount of time it was in the same location as the other mouse in the pair. The information that can be efficiently collected in this apparatus has a variety of applications for pre-clinical research on human CNS disorders, for example major depressive disorder and autism spectrum disorder, in that it can be used to quantify validated endophenotypes or biomarkers of these disorders using rodent models. While the specific configuration of the apparatus described here was designed to answer particular experimental questions, it can be modified in various ways to accommodate different experimental designs. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Frequency-doubling technology perimetry and multifocal visual evoked potential in glaucoma, suspected glaucoma, and control patients

    Directory of Open Access Journals (Sweden)

    Kanadani FN

    2014-07-01

    Full Text Available Fabio N Kanadani,1 Paulo AA Mello,1 Syril K Dorairaj,2 Tereza CM Kanadani31Federal University of Sao Paulo, Sao Paulo, Brazil; 2Mayo Clinic, Department of Ophthalmology, Jacksonville, Florida, USA; 3Sao Jose University Hospital, Belo Horizonte, BrazilIntroduction: The gold standard in functional glaucoma evaluation is standard automated perimetry (SAP. However, SAP depends on the reliability of the patients’ responses and other external factors; therefore, other technologies have been developed for earlier detection of visual field changes in glaucoma patients. The frequency-doubling perimetry (FDT is believed to detect glaucoma earlier than SAP. The multifocal visual evoked potential (mfVEP is an objective test for functional evaluation.Objective: To evaluate the sensitivity and specificity of FDT and mfVEP tests in normal, suspect, and glaucomatous eyes and compare the monocular and interocuar mf VEP.Methods: Ninety-five eyes from 95 individuals (23 controls, 33 glaucoma suspects, 39 glaucomatous were enrolled. All participants underwent a full ophthalmic examination, followed by SAP, FDT, and mfVEP tests. Results: The area under the curve for mean deviation and pattern standard deviation were 0.756 and 0.761, respectively, for FDT, 0.564 and 0.512 for signal and alpha for interocular mfVEP, and 0.568 and 0.538 for signal and alpha for monocular mfVEP. This difference between monocular and interocular mfVEP was not significant. Conclusion: The FDT matrix was superior to mfVEP in glaucoma detection. The difference between monocular and interocular mfVEP in the diagnosis of glaucoma was not significant. Keywords: standard automated perimetry, electrophysiology, glaucomatous eyes

  4. Simulation of the Secondary Frequency Control Capability of the Advanced PSH Technology and Its Application to the SMUD System

    Energy Technology Data Exchange (ETDEWEB)

    Koritarov, Vladimir [Argonne National Lab. (ANL), Argonne, IL (United States); Feltes, James [Argonne National Lab. (ANL), Argonne, IL (United States); Kazachkov, Yuriy [Argonne National Lab. (ANL), Argonne, IL (United States)

    2013-11-01

    The Sacramento Municipal Utility District (SMUD), as a typical balancing authority and project team member, was suggested by the Advanced Technology Modeling TFG for testing the models of the advanced pump storage hydro technology newly developed in the course of the DOE project and for demonstration of the potential benefits of this technology.

  5. Poème Numérique: Technology-Mediated Audience Participation (TMAP) using Smartphones and High-Frequency Sound IDs

    DEFF Research Database (Denmark)

    Kayali, Fares; Bartmann, Christoph; Hödl, Oliver

    2016-01-01

    . In this setup the audience needs to install a smartphone app. Using high-frequency sound IDs music samples and colors can be triggered on the audience’s smartphones without the need to have an internet connection. The resulting soundscape is determined by the samples and parameters selected by the artist......In this paper we discuss a setup for technology-mediated audience participation using smartphones and high-frequency sound IDs. Drawing from the insights of a research project on audience participation in live music we describe a setup for playful music interaction composed of smartphones...

  6. 基于DDS的低杂散捷变频合成器设计%Design of a frequency agility synthesizer with low spurious using DDS technology

    Institute of Scientific and Technical Information of China (English)

    杨杰; 杨光; 蒋国琼; 孙敏

    2011-01-01

    为了对抗有源干扰,雷达系统要求频率合成器具有频率捷变功能;同时要求其杂散抑制越高越好,特别是在输出信号带宽较宽的情况下更是如此.受体积和成本的限制,目前的捷变频频率合成器广泛采用基于直接数字合成(DDS)技术的变频方法.本文基于低杂散,对采用DDS的捷变频频率合成器技术进行了研究,并介绍一种采用时钟频率高达3.2 GHz的新型DDS集成电路的低杂散捷变频频率合成器的设计与实现方法,设计得到的捷变频频率合成器带宽为250 MHz,其杂散抑制指标可满足全频段优于-65 dBc.%In order to counter active jamming, the radar system requires frequency synthesizer to have a frequency agility characteristics; and also requires the spurious suppression the higher the better, especially when the bandwidth of the output signal is wide. Limited by the size and cost, currently, the frequency agility frequency synthesizers are widely based on Direct Digital Synthesis(DDS) technology. Some research and analysis about frequency agility frequency synthesizer technology based on low spurious using DDS are involved in this thesis; simultaneously, a new DDS IC frequency agility frequency synthesizer with the DDS clock frequency up to 3.2 GHz is introduced. The bandwidth of the frequency agility frequency synthesizer is 250 MHz and its spurious suppression index is better than -65 dBc in the whole band.

  7. A Study of Theoretical Models for Managing Technology Change and a Comparison to a Radio Frequency Identification Implementation

    Science.gov (United States)

    1993-09-01

    Organic Model and the Ambidextrous Model for managing technological change. These models were developed outside the DOD to provide guidelines for...based programs, may benefit from the findings of this research. Finally, the researchers identified investigative questions and pertinent limitations of...provided in Chapter V. 1.7 II. Literature Review Introduction When new technologies become available, the AF may benefit from the use of the technology

  8. Industrial integration of high coherence tunable single frequency semiconductor lasers based on VECSEL technology for scientific instrumentation in NIR and MIR

    Science.gov (United States)

    Lecocq, Vincent; Chomet, Baptiste; Ferrières, Laurence; Myara, Mikhaël.; Beaudoin, Grégoire; Sagnes, Isabelle; Cerutti, Laurent; Denet, Stéphane; Garnache, Arnaud

    2017-02-01

    Laser technology is finding applications in areas such as high resolution spectroscopy, radar-lidar, velocimetry, or atomic clock where highly coherent tunable high power light sources are required. The Vertical External Cavity Surface Emitting Laser (VECSEL) technology [1] has been identified for years as a good candidate to reach high power, high coherence and broad tunability while covering a wide emission wavelength range exploiting III-V semiconductor technologies. Offering such performances in the Near- and Middle-IR range, GaAs- and Sb-based VECSEL technologies seem to be a well suited path to meet the required specifications of demanding applications. Built up in this field, our expertise allows the realization of compact and low power consumption marketable products, with performances that do not exist on the market today in the 0.8-1.1 μm and 2-2.5 μm spectral range. Here we demonstrate highly coherent broadly tunable single frequency laser micro-chip, intracavity element free, based on a patented VECSEL technology, integrated into a compact module with driving electronics. VECSEL devices emitting in the Near and Middle-IR developed in the frame of this work [2] exhibit exciting features compared to diode-pumped solid-state lasers and DFB diode lasers; they combine high power (>100mW) high temporal coherence together with a low divergence diffraction limited TEM00 beam. They exhibit a class-A dynamics with a Relative Intensity Noise as low as -140dB/Hz and at shot noise level reached above 200MHz RF frequency (up to 160GHz), a free running narrow linewidth at sub MHz level (fundamental limit at Hz level) with high spectral purity (SMSR >55dB), a linear polarization (>50dB suppression ratio), and broadband continuous tunability greater than 400GHz (frequency) with total tunability up to 3THz. Those performances can all be reached thanks to the high finesse cavity of VECSEL technology, associated to ideal homogeneous QW gain behaviour [3]. In addition

  9. High frequency characteristic of a monolithic 500 °C OpAmp-RC integrator in SiC bipolar IC technology

    Science.gov (United States)

    Tian, Ye; Zetterling, Carl-Mikael

    2017-09-01

    This paper presents a comprehensive investigation of the frequency response of a monolithic OpAmp-RC integrator implemented in a 4H-SiC bipolar IC technology. The circuits and devices have been measured and characterized from 27 to 500 °C. The devices have been modelled to identify that the substrate capacitance is a dominant factor affecting the OpAmp's high-frequency response. Large Miller compensation capacitors of more than 540 pF are required to ensure stability of the internal OpAmp. The measured unit-gain-bandwidth product of the OpAmp is ∼1.1 MHz at 27 °C, and decreases to ∼0.5 MHz at 500 °C mainly due to the reduction of the transistor's current gain. On the other hand, it is not necessary to compensate the integrator in a relatively wide bandwidth ∼0.7 MHz over the investigated temperature range. At higher frequencies, the integrator's frequency response has been identified to be significantly affected by that of the OpAmp and load impedance. This work demonstrates the potential of this technology for high temperature applications requiring bandwidths of several megahertz.

  10. A Study on Effect of Technological Change on the Frequency of Child Labour in the Indian Match Industry

    Science.gov (United States)

    Velayutham, C. Muthu; Palanivel, R. V.; Anbarasan, R.; Sinthuja, M.

    2012-08-01

    The Indian match industry in the southern state of Tamil Nadu has been characterized by child labour and a stagnant technology for over half a century. We investigate the technological changes and industrial restructuring, catalyzed by the changing duty structure that has moved the match industry towards greater mechanization. Our examination indicates that increased mechanization in the production processes has implied greater demand for skilled labour and a decline in child labour.

  11. Technology Use and Frequency and Self-Rated Skills: A Survey of Community-Dwelling Older Adults.

    Science.gov (United States)

    Scanlon, Lorraine; O'Shea, Emma; O'Caoimh, Rónán; Timmons, Suzanne

    2015-07-01

    Many older adults are using technology regularly, but the vast majority still rate their technology skills as poor or average,reflecting their low usage of less-familiar items such as tablet computers. Despite moves toward increasing the use of ICT in the care, rehabilitation, and monitoring of older adults, baseline use of such devices is low. Further study is required to investigate how people's attitudes toward and experience with ICT influence its utility in clinical practice

  12. 基于泵变频调速的航天器热控制技术%Spacecraft Thermal Control Technology Based on Variable Frequency Pump

    Institute of Scientific and Technical Information of China (English)

    宁献文; 张加迅

    2011-01-01

    文章针对某单相流体回路地面原理样机,提出采用泵变频调速技术进行控温,并对系统控温特性进行了地面试验研究,整个瞬态试验过程中控温精度一般都在士0.3℃以内,最大波动也基本不超过±0.5℃,基于泵变频调速技术的热控制策略性能优良、有效,试验结果可供实际工程设计参考.%The traditional temperature control mode using temperature-sensing valve has three deficiencies with the reliability, dynamic behavior, pump operational efficiency. In order to solve these problems, a new thermal control technology based on variable frequency pump was put forward for a fluid loop prototype model. The temperature control performance of the thermal control technology based on variable frequency pump was tested. During all transients, the controlled temperature was within the range of ±0. 3℃ around the set-point, with a maximum admissible variation range of ±0.5℃. Thermal control strategy based on variable frequency pump has effective performance.

  13. Antenna Technology and other Radio Frequency (RF) Communications Activities at the Glenn Research Center in Support of NASA's Exploration Vision

    Science.gov (United States)

    Miranda, Felix A.

    2007-01-01

    NASA s Vision for Space Exploration outlines a very ambitious program for the next several decades of the Space Agency endeavors. Ahead is the completion of the International Space Station (ISS); safely flight the shuttle (STS) until 2010; develop and fly the Crew Exploration Vehicle (Orion) by no later than 2014; return to the moon by no later than 2020; extend human presence across the solar system and beyond; implement a sustainable and affordable human and robotic program; develop supporting innovative technologies, knowledge and infrastructure; and promote international and commercial participation in exploration. To achieve these goals, a series of enabling technologies must be developed or matured in a timely manner. Some of these technologies are: spacecraft RF technology (e.g., high power sources and large antennas which using surface receive arrays can get up to 1 Gbps from Mars), uplink arraying (reduce reliance on large ground-based antennas and high operation costs; single point of failure; enable greater data-rates or greater effective distance; scalable, evolvable, flexible scheduling), software define radio (i.e., reconfigurable, flexible interoperability allows for in flight updates open architecture; reduces mass, power, volume), and optical communications (high capacity communications with low mass/power required; significantly increases data rates for deep space). This presentation will discuss some of the work being performed at the NASA Glenn Research Center, Cleveland, Ohio, in antenna technology as well as other on-going RF communications efforts.

  14. A DVB-RCS Multi-Channel, Multi-Frequency Demodulator Based on a Multi-Tasking Hardware-Software Architecture Using a System on Programmable Chip Technology

    Science.gov (United States)

    van Doninck, A.; Dendoncker, M.; Adriaensen, F.; Delbeke, P.; Rolle, A.; Craey, T.; Krekels, S.

    : This paper highlights a multi-channel, multi-frequency DVB-RCS compatible burst demodulator implementation in a System On Programmable Chip (SOPC) technology. The core of the demodulator architecture is a SOPC device with an ARM processor located internally in FPGA. The ARM processor performs the hard real time signal processing functions and is supported by a COTS standard PC based processor module running Linux/RT-Linux for the non-hard real-time demodulator functions. The implemented architecture differs completely from classic multi-channel solutions, in which the multi- channel functionality is realised by means of a multiple instantiation of the entire demodulator. The paper also discusses the followed methodology for the SOPC design. Keywords: DVB-RCS, multi-channel, multi-frequency, SOPC, FPGA, ARM, RT-Linux

  15. Advances in recombinant DNA technology : corifollitropin alfa, a hybrid molecule with sustained follicle-stimulating activity and reduced injection frequency

    NARCIS (Netherlands)

    Fauser, B. C. J. M.; Mannaerts, B. M. J. L.; Devroey, P.; Leader, A.; Boime, I.; Baird, D. T.

    2009-01-01

    Recombinant DNA technologies have been used to develop longer-acting therapeutic proteins. One approach is to introduce sequences containing additional glycosylation sites. Using this technique, a new chimeric gene has been developed containing the coding sequences of the FSH beta-subunit and the C-

  16. Advances in recombinant DNA technology : corifollitropin alfa, a hybrid molecule with sustained follicle-stimulating activity and reduced injection frequency

    NARCIS (Netherlands)

    Fauser, B. C. J. M.; Mannaerts, B. M. J. L.; Devroey, P.; Leader, A.; Boime, I.; Baird, D. T.

    2009-01-01

    Recombinant DNA technologies have been used to develop longer-acting therapeutic proteins. One approach is to introduce sequences containing additional glycosylation sites. Using this technique, a new chimeric gene has been developed containing the coding sequences of the FSH beta-subunit and the C-

  17. Histologic effects of different technologies for dissection in endoscopic surgery: Nd:YAG laser, high frequency and water-jet.

    Science.gov (United States)

    Schurr, M O; Wehrmann, M; Kunert, W; Melzer, A; Lirici, M M; Trapp, R; Kanehira, E; Buess, G

    1994-01-01

    Precise cutting combined with reliable coagulation of the margins of the lesion is an important requirement for dissection techniques in endoscopic surgery. These requirements are met by the two most common ancillary energy sources applied for endoscopic dissection today, electrosurgery and "thermal lasers", mostly the Nd:YAG. For the comparison of the histological effects of monopolar and bipolar high frequency with the Nd:YAG laser an experimental in vitro and in vivo study has been performed. In order to evaluate the advantages of non thermal dissection for endoscopic procedures, a water jet cutting system was included in the in vitro study. In parenchymatous tissue the water jet was found to be the least traumatic technique, followed by bipolar high frequency, laser and monopolar high frequency. The water jet was not applicable for intestinal dissection since uncontrolled bloating of the rectal wall with uncontrolled disruption of the tissue layers occurred. A general disadvantage is that secure haemostasis in the line of incision is hard to achieve. In the microscopic comparison of the shape of the incision, the Nd:YAG laser produced the smoothest lesions with well-defined margins. The monopolar technique was more often associated with irregular and sometimes fissured margins. These results were confirmed in the in vivo part of the study (Transanal Endoscopic Microsurgery).

  18. 基于扫频技术的乐甫波器件测试系统%Measurement System of Love Wave Device Based on Frequency Scanning Technology

    Institute of Scientific and Technical Information of China (English)

    夏前亮; 陈智军; 陈涛; 卢旭; 黄鑫

    2012-01-01

    The structure of Love wave device is introduced, the Love wave device is designed and implemented, and the design parameters are given. The measurement system based on the frequency scanning technology is set up, which includes the signal source, the signal acquisition module, the micro controller module, etc. The sine excitation signal is produced with a certain frequency interval in a certain frequency range by the DDS chip AD9912. The amplitude ratio of the input excitation signal to the output response signal at each frequency point in the frequency scanning range is acquired by AD8302, and the amplitude-frequency curve is characterized and the resonance frequency is obtained, accordingly. The measurement result of this system is in accordance with that of the network analyzer, and this system can realize the frequency scanning function of the network analyzer.%介绍了乐甫波器件的结构,设计制作了乐甫波器件,给出了乐甫器件的制作参数,搭建了基于扫频技术的测试系统,包括信号源模块、信号采集模块、微控制器模块等.通过DDS芯片AD9912在一定频率范围内,以一定频率间隔扫频输出高频正弦激励信号,利用AD8302芯片测量扫频范围内每一频率点的器件输入激励信号与输出响应信号幅值比,描绘出幅频特性曲线,并给出器件谐振频率.该测试系统的测量结果与网络分析仪基本一致,实现了网络分析仪的扫频功能.

  19. New technologies applied to food frequency questionnaires: a current perspective Nuevas tecnologías aplicadas a los cuestionarios de frecuencia de consumo de alimentos: una perspectiva actual

    Directory of Open Access Journals (Sweden)

    P. García-Segovia

    2011-08-01

    Full Text Available The food frequency questionnaires are widely used in epidemiological researches like dietary assessment method. Traditionally, they have been self-administered in paper but the use of information and communication technologies has led to develop Internet and computerized food frequency questionnaires. It is the objective of this article to offer a global perspective of the new technologies applied to FFQ. It will be presented the purpose of the food frequency questionnaire, the number of strengths of the web-based surveys versus print-surveys and finally, a description of the manuscripts that have used web-based and computerized FFQ.Los cuestionarios de frecuencia de consumo de alimentos son muy utilizados en investigaciones epidemiológicas como método para evaluar la dieta. Tradicionalmente, han sido autoadministrados en papel, pero el uso de las tecnologías de la información y la comunicación (TICs ha permitido desarrollar cuestionarios de frecuencia de consumo de alimentos computerizados y a través de Internet. El objetivo de este artículo es ofrecer una perspectiva actual del uso de las nuevas tecnologías aplicadas al diseño e interpretación de los cuestionarios de frecuencia de consumo de alimentos. En el presente trabajo se resumen los objetivos de los cuestionarios de frecuencia de consumo de alimentos, las ventajas de los cuestionarios autoadministrados por Internet frente a los administrados en papel y finalmente, se describirán diferentes estudios que han usado cuestionarios de frecuencia de consumo de alimentos autoadministrados mediante el uso de ordenador o a través de Internet.

  20. Radio frequency (unidentification: Results from a proof-of-concept trial of the use of RFID technology to measure microenterprise turnover in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Suresh de Mel

    2016-06-01

    Full Text Available Accurate measurement of stock levels, turnover, and profitability in microenterprises in developing countries is difficult due to the fact that the majority of these firms do not keep detailed records. We test the use of radio frequency identification (RFID tags as a means of objectively measuring stock levels and stock flow in small retail firms in Sri Lanka. In principle this offers the potential to track stock movements accurately. We compare the stock counts obtained from RFID reads to physical stock counts and to survey responses. We have three main findings. First, current RFID-technology is more difficult to use, and more time-consuming to employ, than we envisaged. Second, the technology works reasonably well for paper products, but very poorly for most products sold by microenterprises: on average we were able to read only about one-quarter of the products tagged, and there was considerable day-to-day variation in read-efficiency. This results from technical issues arising from read efficiency being comprised by liquids, metal, and product stacking. Third, a comparison of survey responses and physical stock-takes shows much higher accuracy for survey measures than RFID. As a result, we conclude that this technology is currently unsuitable for improving stock measurement in microenterprises, except perhaps for a few products.

  1. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  2. Electrical properties of radio-frequency sputtered HfO{sub 2} thin films for advanced CMOS technology

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Pranab Kumar; Roy, Asim, E-mail: 28.asim@gmail.com [Department of Physics, National Institute of Technology Silchar, Silchar-788010, Assam, India Phone: +91-3842-224879 (India)

    2015-08-28

    The Hafnium oxide (HfO{sub 2}) high-k thin films have been deposited by radio frequency (rf) sputtering technique on p-type Si (100) substrate. The thickness, composition and phases of films in relation to annealing temperatures have been investigated by using cross sectional FE-SEM (Field Emission Scanning Electron Microscope) and grazing incidence x-ray diffraction (GI-XRD), respectively. GI-XRD analysis revealed that at annealing temperatures of 350°C, films phases change to crystalline from amorphous. The capacitance-voltage (C-V) and current-voltage (I-V) characteristics of the annealed HfO{sub 2} film have been studied employing Al/HfO{sub 2}/p-Si metal–oxide–semiconductor (MOS) structures. The electrical properties such as dielectric constant, interface trap density and leakage current density have been also extracted from C-V and I-V Measurements. The value of dielectric constant, interface trap density and leakage current density of annealed HfO{sub 2} film is obtained as 23,7.57×1011eV{sup −1} cm{sup −2} and 2.7×10{sup −5} Acm{sup −2}, respectively. In this work we also reported the influence of post deposition annealing onto the trapping properties of hafnium oxide and optimized conditions under which no charge trapping is observed into the dielectric stack.

  3. Glaucoma progression detection with frequency doubling technology (FDT) compared to standard automated perimetry (SAP) in the Groningen Longitudinal Glaucoma Study.

    Science.gov (United States)

    Wesselink, Christiaan; Jansonius, Nomdo M

    2017-09-01

    To determine the usefulness of frequency doubling perimetry (FDT) for progression detection in glaucoma, compared to standard automated perimetry (SAP). Data were used from 150 eyes of 150 glaucoma patients from the Groningen Longitudinal Glaucoma Study. After baseline, SAP was performed approximately yearly; FDT every other year. First and last visit had to contain both tests. Using linear regression, progression velocities were calculated for SAP (Humphrey Field Analyzer) mean deviation (MD) and FDT MD and the number of test locations with a total deviation probability below p SAP and FDT classifications were made using a Mantel Haenszel chi-square test. Longitudinal signal-to-noise ratios (LSNRs) were calculated, per patient and per technique, defined as progression velocity divided by the standard deviation of the residuals. Mean (SD) follow-up was 6.4 (1.7) years; median (interquartile range [IQR]) baseline SAP MD -6.6 (-14.2 to -3.6) dB. On average 8.2 and 4.5 tests were performed for SAP and FDT, respectively. Median (IQR) MD slope was -0.16 (-0.46 to +0.02) dB/year for SAP and -0.05 (-0.39 to +0.17) dB/year for FDT. Mantel Haenszel chi-squares of SAP MD vs FDT MD and TD were 12.5 (p SAP MD (median -0.17 yr(-1) ) were better than those for FDT MD (-0.04 yr(-1) ; p = 0.010). FDT may be a useful technique for monitoring glaucoma progression in patients who cannot perform SAP reliably. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

  4. Use of very low frequency technology for diagnostic in medium voltage electric cables; Utilizacao da tecnologia VLF para diagnostico de cabos eletricos de media tensao

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Flavio Costa; Pinho, Wilson Pereira de [Companhia Siderurgica Nacional (CSN), Volta Redonda, RJ (Brazil). Gerencia de Distribuicao de Energeticos

    2010-07-01

    The present technical contribution presents a new technology used in the Companhia Siderurgica Nacional (CSN) to diagnose operating conditions, useful life and faults in medium voltage electrical cables. The Very Low Frequency is a nondestructive electrical testing, conducted in medium voltage electrical cables, designed to measure the overall state of insulation of the cables, and the precise location of the fault before the failure. Through two types of tests, Delta Tangent and Partial Discharge, it is possible to make a complete diagnosis of insulation performance of the cable and also detect the fault. The implantation of this predictive technique, will monitor the useful life of medium voltage cables, avoiding potential failures in electrical circuits of Usina Presidente Vargas, allowing the intervention of maintenance before the failure, that result in interference in the production process. (author)

  5. Comparison of visual field test results obtained through Humphrey matrix frequency doubling technology perimetry versus standard automated perimetry in healthy children

    Directory of Open Access Journals (Sweden)

    Sibel Kocabeyoglu

    2013-01-01

    Full Text Available Aims : The aim of this study was to compare the visual field test results in healthy children obtained via the Humphrey matrix 24-2 threshold program and standard automated perimetry (SAP using the Swedish interactive threshold algorithm (SITA-Standard 24-2 test. Materials and Methods: This prospective study included 55 healthy children without ocular or systemic disorders who underwent both SAP and frequency doubling technology (FDT perimetry visual field testing. Visual field test reliability indices, test duration, global indices (mean deviation [MD], and pattern standard deviation [PSD] were compared between the 2 tests using the Wilcoxon signed-rank test and paired t-test. The performance of the Humphrey field analyzer (HFA 24-2 SITA-standard and frequency-doubling technology Matrix 24-2 tests between genders were compared with Mann-Whitney U-test. Results: Fifty-five healthy children with a mean age of 12.2 ± 1.9 years (range from 8 years to 16 years were included in this prospective study. The test durations of SAP and FDT were similar (5.2 ± 0.5 and 5.1 ± 0.2 min, respectively, P = 0.651. MD and the PSD values obtained via FDT Matrix were significantly higher than those obtained via SAP (P < 0.001, and fixation losses and false negative errors were significantly less with SAP (P < 0.05. A weak positive correlation between the two tests in terms of MD (r = 0.352, P = 0.008 and PSD (r = 0.329, P = 0.014 was observed. Conclusion: Children were able to complete both the visual test algorithms successfully within 6 min. However, SAP testing appears to be associated with less depression of the visual field indices of healthy children. FDT Matrix and SAP should not be used interchangeably in the follow-up of children.

  6. The in-line measurement of plant cell biomass using radio frequency impedance spectroscopy as a component of process analytical technology.

    Science.gov (United States)

    Holland, Tanja; Blessing, Daniel; Hellwig, Stephan; Sack, Markus

    2013-10-01

    Radio frequency impedance spectroscopy (RFIS) is a robust method for the determination of cell biomass during fermentation. RFIS allows non-invasive in-line monitoring of the passive electrical properties of cells in suspension and can distinguish between living and dead cells based on their distinct behavior in an applied radio frequency field. We used continuous in situ RFIS to monitor batch-cultivated plant suspension cell cultures in stirred-tank bioreactors and compared the in-line data to conventional off-line measurements. RFIS-based analysis was more rapid and more accurate than conventional biomass determination, and was sensitive to changes in cell viability. The higher resolution of the in-line measurement revealed subtle changes in cell growth which were not accessible using conventional methods. Thus, RFIS is well suited for correlating such changes with intracellular states and product accumulation, providing unique opportunities for employing systems biotechnology and process analytical technology approaches to increase product yield and quality. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  8. 一种适用于物联网设备的自适应跳频方法%Frequency-adaptive Technology Implementing in Internet of Things System

    Institute of Scientific and Technical Information of China (English)

    楼亮亮; 熊勇; 周苗; 鲍星合; 谷宇章

    2014-01-01

    The license-free ISM 2.4 GHz band is widely used on a global scale , and the new access of wireless systems in the ISM band is interfered by other wireless systems .Aiming at this disadvantages described above , this paper presents a method based on technology of adaptive frequency hopping ( AFH) , avoiding using those frequency points interfered to improve the relia-bility and antijamming capability of communication .At first, this paper introduced two algorithms to support AFH technology:time synchronization algorithm and channel estimation algorithm , then introduced the specific implementation process of CC 2500-based IOT devices , and made a specific practice on the CC 2500-based devices .And at last , experimental analysis shows that the frequency hopping algorithm is of a certain practicality and advanced .%由于2.4 GHz频段的免授权性和开放性,新的无线系统在该频段内的自由接入必定会受到同频系统的干扰。针对上述问题,采用自适应跳频技术保证通信双方在通信中自动适应信道变化,实时避开频率集中被干扰的频点,提高通信的可靠性和抗干扰能力。首先介绍自适应跳频技术的2种相关算法,时间同步及信道评估算法,接着介绍基于CC2500的物联网设备的具体实现流程,并采用公共信道实现跳频信令的传输,在基于CC2500的物联网设备上做了具体实践,最后通过实验分析表明,该跳频算法具有一定的实用性和先进性。

  9. A review of radio frequency identification technology for the anatomic pathology or biorepository laboratory: Much promise, some progress, and more work needed

    Directory of Open Access Journals (Sweden)

    Jerry J Lou

    2011-01-01

    Full Text Available Patient safety initiatives throughout the anatomic laboratory and in biorepository laboratories have mandated increasing emphasis on the need for accurately identifying and tracking biospecimen assets throughout their production lifecycle and for archiving/retrieval purposes. However, increasing production volume along with complex workflow characteristics, reliance on manual production processes, and required asset movement to disparate destinations throughout asset lifecycles continue to challenge laboratory efforts. Radio Frequency Identification (RFID technology, use of radio waves to communicate data between electronic tags attached to objects and a reader, shows significant potential to facilitate and overcome these hurdles. Advantages over traditional barcode labeling include readability without direct line-of-sight alignment to the reader, ability to read multiple tags simultaneously, higher data storage capacity, faster data transmission rate, and capacity to perform multiple read-writes of data to the tag. Most importantly, use of radio waves decreases the need to manually scan each asset, and at each step, identification or tracking event is needed. Temperature monitoring by on-board sensors and three-dimensional position tracking are additional potential benefits of using RFID technology. To date, barriers to implementation of RFID systems in the anatomic laboratory include increased associated costs of tags and readers, system software, data security concerns, lack of specific data standards for stored information, and potential for technological obsolescence during decades of specimen storage. Novel RFID production techniques and increased production capacity are projected to lower costs of some tags to a few cents each. Potentially, information security concerns can be addressed by techniques such as shielding, data encryption, and tag pseudonyms. Commitment by stakeholder groups to develop RFID tag data standards for anatomic

  10. A review of radio frequency identification technology for the anatomic pathology or biorepository laboratory: Much promise, some progress, and more work needed.

    Science.gov (United States)

    Lou, Jerry J; Andrechak, Gary; Riben, Michael; Yong, William H

    2011-01-01

    Patient safety initiatives throughout the anatomic laboratory and in biorepository laboratories have mandated increasing emphasis on the need for accurately identifying and tracking biospecimen assets throughout their production lifecycle and for archiving/retrieval purposes. However, increasing production volume along with complex workflow characteristics, reliance on manual production processes, and required asset movement to disparate destinations throughout asset lifecycles continue to challenge laboratory efforts. Radio Frequency Identification (RFID) technology, use of radio waves to communicate data between electronic tags attached to objects and a reader, shows significant potential to facilitate and overcome these hurdles. Advantages over traditional barcode labeling include readability without direct line-of-sight alignment to the reader, ability to read multiple tags simultaneously, higher data storage capacity, faster data transmission rate, and capacity to perform multiple read-writes of data to the tag. Most importantly, use of radio waves decreases the need to manually scan each asset, and at each step, identification or tracking event is needed. Temperature monitoring by on-board sensors and three-dimensional position tracking are additional potential benefits of using RFID technology. To date, barriers to implementation of RFID systems in the anatomic laboratory include increased associated costs of tags and readers, system software, data security concerns, lack of specific data standards for stored information, and potential for technological obsolescence during decades of specimen storage. Novel RFID production techniques and increased production capacity are projected to lower costs of some tags to a few cents each. Potentially, information security concerns can be addressed by techniques such as shielding, data encryption, and tag pseudonyms. Commitment by stakeholder groups to develop RFID tag data standards for anatomic pathology and

  11. Single frequency semiconductor lasers

    CERN Document Server

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui

    2017-01-01

    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  12. The Factors Influencing the Development of Radio Frequency Identification Technology in E-Supply Chain Management (Case study: Iran Khodro Industrial Group (IKCO

    Directory of Open Access Journals (Sweden)

    Ali Sanayei

    2011-07-01

    The application of Radio Frequency Identification (RFID for the purpose of tracking each single part in the automotive supply chain management has become very crucial in recent years. In this study, the factors influencing the development of RFID in Iran Khodro Industrial Group as well as their weight and ranking are evaluated. It is notewothy that the Lin framework factors have been used as the basis of this research. The Fuzzy Delphi, Delphi, and Fuzzy Analytic Hierarchy Process (FAHP methods were applied for the research three stages. In the first stage, three of the Lin framework factors were rejected and replaced with seven more new factors. In the second stage, after three times performance of Delphi method, the dimension of each of the new seven factors was recognized, and finally in the third stage, the weight and ranking of factors and dimensions which influence the RFID development in supply chain management in our case study, Iran Khodro Company, was calculated. The results of the research have shown that the International Standard and Specification dimension has the highest weight among other influential dimensions. Also, the dimensions of Security, Cost, Infrastructure, Technology, and other factors have respectively the next highest weight after the International Standard and Specification dimension

  13. 激光频率上转换回波信号探测技术研究%Echo Signal Detection Technology of Laser Frequency Up-conversion

    Institute of Scientific and Technical Information of China (English)

    滕岳; 吕勇; 陈青山; 牛春晖; 刘力双

    2016-01-01

    Frequency conversion characteristics, produced by interact between laser and the object, are of great significance for target detection. The echo signal of frequency up-conversion has weak strength, pulse stretching, phase shift characteristics etc. According to this echo feature, we use the PIN photodiode as detector, and extract echo signal using lock-in amplification technology. With the help of the preamplifier circuit and AC signal amplifier circuit, the transformation and amplification of echo signal can be achieved, as well as phase sensitive detector, which is used to realize echo signal extraction. Echo detection system is set up and experimental tests show that detection system based on lock-in amplifier can suppress noise signal, as a consequence, the system can extract echo signal from background of big noise. When target at 1.5 meters in front of detection system, the output signal-noise ratio (SNR) of the system is 16.9 dB.%激光与物体相互作用产生的频率转换特性,对于目标探测具有重要的意义。频率上转换回波信号具有强度弱、脉冲展宽、有相移等特性。根据这种回波特性,论文以PIN光电二极管为探测器件,采用锁定放大技术进行回波信号检测。通过前置放大电路、交流信号放大电路完成回波信号的转换放大,运用相敏检波器实现回波信号提取,并搭建了回波探测系统。实验测试表明,基于锁定放大器的探测系统能够抑制杂波信号,从强噪声背景中提取有效回波信号,针对探测系统前方1.5 m处的探测靶标,系统的输出信噪比为16.9 dB。

  14. Relationships between range access as monitored by radio frequency identification technology, fearfulness, and plumage damage in free-range laying hens.

    Science.gov (United States)

    Hartcher, K M; Hickey, K A; Hemsworth, P H; Cronin, G M; Wilkinson, S J; Singh, M

    2016-05-01

    Severe feather-pecking (SFP), a particularly injurious behaviour in laying hens (Gallus gallus domesticus), is thought to be negatively correlated with range use in free-range systems. In turn, range use is thought to be inversely associated with fearfulness, where fearful birds may be less likely to venture outside. However, very few experiments have investigated the proposed association between range use and fearfulness. This experiment investigated associations between range use (time spent outside), fearfulness, plumage damage, and BW. Two pens of 50 ISA Brown laying hens (n=100) were fitted with radio frequency identification (RFID) transponders (contained within silicone leg rings) at 26 weeks of age. Data were then collected over 13 days. A total of 95% of birds accessed the outdoor run more than once per day. Birds spent an average duration of 6.1 h outside each day over 11 visits per bird per day (51.5 min per visit). The top 15 and bottom 15 range users (n=30), as determined by the total time spent on the range over 13 days, were selected for study. These birds were tonic immobility (TI) tested at the end of the trial and were feather-scored and weighed after TI testing. Birds with longer TI durations spent less time outside (P=0.01). Plumage damage was not associated with range use (P=0.68). The small group sizes used in this experiment may have been conducive to the high numbers of birds utilising the outdoor range area. The RFID technology collected a large amount of data on range access in the tagged birds, and provides a potential means for quantitatively assessing range access in laying hens. The present findings indicate a negative association between fearfulness and range use. However, the proposed negative association between plumage damage and range use was not supported. The relationships between range use, fearfulness, and SFP warrant further research.

  15. Real-time monitoring for detection of retained surgical sponges and team motion in the surgical operation room using radio-frequency-identification (RFID) technology: a preclinical evaluation.

    Science.gov (United States)

    Kranzfelder, Michael; Zywitza, Dorit; Jell, Thomas; Schneider, Armin; Gillen, Sonja; Friess, Helmut; Feussner, Hubertus

    2012-06-15

    Technical progress in the surgical operating room (OR) increases constantly, facilitating the development of intelligent OR systems functioning as "safety backup" in the background of surgery. Precondition is comprehensive data retrieval to identify imminent risky situations and inaugurate adequate security mechanisms. Radio-frequency-identification (RFID) technology may have the potential to meet these demands. We set up a pilot study investigating feasibility and appliance reliability of a stationary RFID system for real-time surgical sponge monitoring (passive tagged sponges, position monitoring: mayo-stand/abdominal situs/waste bucket) and OR team tracking (active transponders, position monitoring: right/left side of OR table). In vitro: 20/20 sponges (100%) were detected on the mayo-stand and within the OR-phantom, however, real-time detection accuracy declined to 7/20 (33%) when the tags were moved simultaneously. All retained sponges were detected correctly. In vivo (animal): 7-10/10 sterilized sponges (70%-100%) were detected correctly within the abdominal cavity. OR-team: detection accuracy within the OR (surveillance antenna) and on both sides of the OR table (sector antenna) was 100%. Mean detection time for position change (left to right side and contrariwise) was 30-60 s. No transponder failure was noted. This is the first combined RFID system that has been developed for stationary use in the surgical OR. Preclinical evaluation revealed a reliable sponge tracking and correct detection of retained textiles (passive RFID) but also demonstrated feasibility of comprehensive data acquisition of team motion (active RFID). However, detection accuracy needs to be further improved before implementation into the surgical OR. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Ahşap Kurutmada Çevre Dostu bir Teknoloji : Yüksek Frekans / High-Frequency-Vacuum Wood Drying Technology

    Directory of Open Access Journals (Sweden)

    Cengiz Güler

    2012-12-01

    Full Text Available Katma değerli olmasına karşın kurutulması güç ağaç türlerine ait kalın kerestelerin, klasik kurutma metoduyla çok uzun sürelerde kurutulabilmesi ve istenen kalite düzeylerinin tam olarak elde edilememesi nedeniyle günümüzde Yüksek Frekans-Vakum kombinasyonlu kurutma metodu (YFV kendini göstermiş durumdadır. Geçmişte özellikle yatırım maliyetleri ve teknolojik altyapı zorlukları nedeniyle yaygınlaşamayan bu yöntem tekrar güncel hale gelmiştir. Bu kurutma metodunda prensip; ısı kaynağının, elektrik enerjisi olmasıdır. Dolayısı ile katı ve sıvı yakıta göre çevre dostu olduğu kabul edilebilir. Bu metot ile ağaç malzemeye gönderilen elektromanyetik dalgaların meydana getirdiği ısıdan yararlanmak suretiyle, kalın ve güç kuruyan, başlangıç nemi yüksek olan ağaç türlerinin %10 un altındaki sonuç nemlerine kadar çok kısa sürelerde kurutulması amaçlanmaktadır. Bu çalışmada öncelikle kurutma teknoloji hakkında genel bilgi verilmiştir. Daha sonra ise, günümüze kadar yapılan orijinal çalışmalar özetlenerek klasik yöntemle kurutulmasında önemli zorluklar olan, kurutma süresi çok uzun olan veya hiç kurutulamayan Meşe, Ceviz, Kayın, İroko, Kestane gibi ağaç türlerinin kalın kerestelerinin kurutulması denemelerinden elde edilen sonuçlar ortaya konulmuştur. Son bölümde ise elde edilen bu sonuçlar özellikle metodun donanım ve işletme giderleri, ortaya çıkan kurutma süreleri ve kalite düzeyleri, çevreye uyumlu teknoloji ekseninde ele alınmıştır. Ayrıca, bu metodun kereste kurutma dışında diğer tarımsal ürün ve atıkların kurutulmasında kullanılabilir olması nedeniyle çevreye uyumlu üretim ve geri dönüşüme sağladığı katkı da bu kapsamda irdelenmiştir. High-Frequency-Vacuum Wood Drying Technology High density wood species dried very long period’s and very low quality levels with method in conventional drying. So High

  17. Frequency conversion technology transformation plan design on The coal warehouse belt system%煤矿上仓皮带系统变频技术改造方案设计

    Institute of Scientific and Technical Information of China (English)

    田伟

    2012-01-01

      Frequency control technology is an ideal high-efficiency and high-performance speed control means,which through the change of the motor power supply frequency, so as to realize the speed adjustment.%  变频调速技术就是这样通过改变电动机的供电电源频率,从而实现速度调节的,是一种理想的高效率、高性能的调速手段。

  18. 变频调速技术对静叶可调轴流风机结构设计的影响%Influence of Frequency Conversion Technology on the Structure Design of Axial Fan with Static Adjustable Vanes

    Institute of Scientific and Technical Information of China (English)

    邓辉; 王吉珍; 胡灿

    2013-01-01

      针对静叶可调轴流风机采用变频调速的运行特点,从引风机结构方面进行分析,介绍风机加装变频调速装置后对风机结构的影响及解决方法。%Aiming at the operating characteristic of axial fan with static adjustable vanes adopting frequency conversion technology, this paper has analyzed the structure of fan and introduced the influence of frequency conversion equipment installed on the fan’ s structure and the solving methods.

  19. Waveform frequency notching

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W.; Andrews, John

    2017-05-09

    The various technologies presented herein relate to incorporating one or more notches into a radar spectrum, whereby the notches relate to one or more frequencies for which no radar transmission is to occur. An instantaneous frequency is monitored and if the frequency is determined to be of a restricted frequency, then a radar signal can be modified. Modification can include replacing the signal with a signal having a different instantaneous amplitude, a different instantaneous phase, etc. The modification can occur in a WFS prior to a DAC, as well as prior to a sin ROM component and/or a cos ROM component. Further, the notch can be dithered to enable formation of a deep notch. The notch can also undergo signal transitioning to enable formation of a deep notch. The restricted frequencies can be stored in a LUT against which an instantaneous frequency can be compared.

  20. Carrier Frequency Intelligent Power-Saving Technology Application in Td-Scdma LTE Communication Network%载频智能节电技术在TD-LTE通信网络中的应用

    Institute of Scientific and Technical Information of China (English)

    唐文良

    2015-01-01

    现今TD-LTE通信网络在人们身边无处不在,如中国移动联通等.基站的能耗在移动通信网络中占了一半以上.因此针对耗能这方面我们提出了载频智能节电技术.载频智能节电技术可达到节能减排的效果.文中先是介绍节能的意义以及为什么节能.然后我们了解具体载频基站的组成部分以及功耗比例.关断节能技术的原理以及实施方案,接着从各方面条件因素来完善智能节能技术.不同场景不同时段需要的功耗来制定不同的方案.对比不同的节能技术需要的条件因数以及外在的因数来评论载频智能节电技术.在这之前GSM系统中,就有从GSM网络的方面考虑,根据各方面的因数来考虑提出了两个各节能方法,其一是针对基站主设备其二是载频关断节能技术.根据TD-LTE系统基站主设备的运行原理来分析载频关断节能技术在基站系统中的实用性以及节能性.全方面的剖析载频智能节电技术在通信网络应用中意义.%nowadays the td-scdma LTE communication network in people around everywhere, such as China mobile, unicom, etc. The energy consumption of the base station in mobile communication network in the accounts for more than half. So for the con-sumption ways we carrier frequency intelligent power saving technology were put forward. Carrier frequency intelligent power sav-ing technology can achieve the effect of energy conservation and emissions reduction. Why in this paper, we first introduce the sig-nificance of energy saving and energy saving. Then we can know the specific carrier frequency part of base station and the power consumption ratio. Shut off the principle of energy saving technology and implementation plan, then factors from various aspects condition to improve the intelligent energy-saving technologies. Different at different times the power consumption of the need to develop different scenarios. Comparison of different energy saving

  1. Study on continuous electromagnetic surveys precisely controlled of frequency. Annual report on the field of advancing basic technology in 1996 fiscal year

    Energy Technology Data Exchange (ETDEWEB)

    Sanada, Yoshinori; Yamashita, Yoshihiro; Watanabe, Toshiki; Hasegawa, Takeshi; Yabuuchi, Satoshi

    1997-08-01

    This study aims at research and development of a system to control on high precision frequency of electromagnetic energy changing in tangential wave and to send it to underground continuously for long time, on geophysical investigation to analyze underground structure due to observation of underground response to it. By adopting this system, expansion of investigation depth, upgrading of analytical accuracy and miniaturization of investigation appliance were aimed. In 1996 fiscal year, in order to understand features of electromagnetic phenomenon over a wide range, a method to measure underground response to analyze its structure due to electromagnetic induction phenomenon by using comparative low frequency range of some tens Hz to some KHz at transmission frequency and a method to detect micro structure (for example crack, and so on) from transmittance and reflection phenomena by using comparatively high frequency range of some tens MHz to some GHz were investigated by using computer simulation. (G.K.)

  2. Quantum frequency downconversion experiment

    CERN Document Server

    Takesue, Hiroki

    2010-01-01

    We report the first quantum frequency downconversion experiment. Using the difference frequency generation process in a periodically poled lithium niobate waveguide, we successfully observed the phase-preserved frequency downconversion of a coherent pulse train with an average photon number per pulse of $<$1, from the 0.7-$\\mu$m visible wavelength band to the 1.3-$\\mu$m telecom band. We expect this technology to become an important tool for flexible photonic quantum networking, including the realization of quantum repeater systems over optical fiber using atom-photon entanglement sources for the visible wavelength bands.

  3. Integration Of Low-Cost Single-Frequency GPS Stations Using 'Spider' Technology Within Existing Dual-Frequency GPS Network at Soufrière Hills Volcano, Montserrat (West Indies): Processing And Results

    Science.gov (United States)

    Pascal, K.; Palamartchouk, K.; Lahusen, R. G.; Young, K.; Voight, B.

    2015-12-01

    Twenty years ago, began the eruption of the explosive Soufrière Hills Volcano, dominating the southern part of the island of Montserrat, West Indies. Five phases of effusive activity have now occurred, characterized by dome building and collapse, causing numerous evacuations and the emigration of half of the population. Over the years, the volcano monitoring network has greatly expanded. The GPS network, started from few geodetic markers, now consists of 14 continuous dual frequency GPS stations, distributed on and around the edifice, where topography and vegetation allow. The continuous GPS time series have given invaluable insight into the volcano behavior, notably revealing deflation/inflation cycles corresponding to phases and pauses of effusive activity, respectively. In 2014, collaboration of the CALIPSO Project (Penn State; NSF) with the Montserrat Volcano Observatory enriched the GPS and seismic monitoring networks with six 'spider' stations. The 'spiders', developed by R. Lahusen at Cascades Volcano Observatory, are designed to be deployed easily in rough areas and combine a low cost seismic station and a L1-only GPS station. To date, three 'spiders' have been deployed on Soufrière Hills Volcano, the closest at ~1 km from the volcanic conduit, adjacent to a lava lobe on the dome. Here we present the details of GPS data processing in a network consisting of both dual and single frequency receivers ('spiders') using GAMIT/GLOBK software. Processing together single and dual frequency data allowed their representation in a common reference frame, and a meaningful geophysical interpretation of all the available data. We also present the 'spiders' time series along with the results from the rest of the network and examine if any significant deformation, correlating with other manifestations of volcanic activity, has been recorded by the 'spiders' since deployment. Our results demonstrate that low cost GNSS equipment can serve as valuable components in volcano

  4. 国内外高频振动筛技术与设备现状及发展趋势%Current situation and development tendency of high-frequency vibration screen technology and equipments at home and abroad

    Institute of Scientific and Technical Information of China (English)

    赵环帅; 鲍玉新; 陈思元; 杨秀秀

    2011-01-01

    The paper introduces the main technical characteristics of the high-frequency vibration screen and analyzes the study situation of high-frequency vibration screen technology at home and abroad. It briefly introduces the main characteristics of commonly used high-frequency vibration screens at present, and proposes the future development tendency of the high-frequency vibration screen according to current issues about the development of the high-frequency vibration screen. The proposed development tendency includes the application of advanced analysis software and testing tools for optimization and analysis, study on manufacturing process of the high-frequency vibration screen as well as study on structure of rubber springs, sieving plates and vibration exciters, study on relationship between technical parameters and process parameters, developing towards large scale and fineness, decreasing operation noise of the high-frequency vibration screen.%介绍了高频振动筛的主要工艺特点,对国内外高频振动筛技术的研究现状进行了分析,对目前市场上常见的高频振动筛的主要特点进行了简单介绍。针对目前高频振动筛发展存在的问题,提出了未来高频振动筛的发展趋势:采用先进的分析软件与测试工具进行优化分析;高频振动筛加工工艺、橡胶弹簧、筛板、激振器结构的研究;技术参数与工艺参数之间关系的研究;向大型化和精细化发展;降低高频振动筛工作噪声的方法等。

  5. Plasma ion sources and ion beam technology inmicrofabrications

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Lili [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    For over decades, focused ion beam (FIB) has been playing a very important role in microscale technology and research, among which, semiconductor microfabrication is one of its biggest application area. As the dimensions of IC devices are scaled down, it has shown the need for new ion beam tools and new approaches to the fabrication of small-scale devices. In the meanwhile, nanotechnology has also deeply involved in material science research and bioresearch in recent years. The conventional FIB systems which utilize liquid gallium ion sources to achieve nanometer scale resolution can no longer meet the various requirements raised from such a wide application area such as low contamination, high throughput and so on. The drive towards controlling materials properties at nanometer length scales relies on the availability of efficient tools. In this thesis, three novel ion beam tools have been developed and investigated as the alternatives for the conventional FIB systems in some particular applications. An integrated focused ion beam (FIB) and scanning electron microscope (SEM) system has been developed for direct doping or surface modification. This new instrument employs a mini-RF driven plasma source to generate focused ion beam with various ion species, a FEI two-lens electron (2LE) column for SEM imaging, and a five-axis manipulator system for sample positioning. An all-electrostatic two-lens column has been designed to focus the ion beam extracted from the source. Based on the Munro ion optics simulation, beam spot sizes as small as 100 nm can be achieved at beam energies between 5 to 35 keV if a 5 μm-diameter extraction aperture is used. Smaller beam spot sizes can be obtained with smaller apertures at sacrifice of some beam current. The FEI 2LE column, which utilizes Schottky emission, electrostatic focusing optics, and stacked-disk column construction, can provide high-resolution (as small as 20 nm) imaging capability, with fairly long working distance (25

  6. The Application of Three-level Voltage Type High Voltage Frequency Conversion Technology in Ocean Engineering Ships%三电平电压型高压变频技术在海洋工程船的应用

    Institute of Scientific and Technical Information of China (English)

    宋艳琼

    2014-01-01

    节能减排、绿色环保,变频电力驱动技术是国内外船舶上应用的发展趋势.特别体现在海洋工程船的大型施工设备和施工设备的驱动系统上.阐述了变频电力驱动技术应用于海洋工程船的优点,介绍了三电平电压型高压变频技术的发展.对三电平电压型高压变频技术进行原理简述,给出了三电平空间电压矢量控制调速系统的主电路拓扑结构,分析了三电平空间电压矢量控制算法的实现,利用MATLAB 7.0/SIMULINK 6.0进行了三电平电压型高压变频调速系统的建模和仿真.%For the purpose of energy saving and emission reduction and green environmental protection , frequency conversion electric drive technology in the world is a development trend applied in ships .Especially this is embodied in large-scale construction equipment of ocean engineering ships and the drive system to construction equipment .This paper elaborates the advantages of variable frequency electric drive technology application in ocean engineering ships , and introduces the development of three-level voltage type high voltage frequency conversion technology.Also, the author illustrates the theories of three-level voltage type high voltage frequency conversion technology , and gives the main circuit topology structure of the three-level space voltage vector control speed regulation system , and analyzes the three-level space voltage vector control algorithm implementation , and finally builds a modeling and simulation of the three-level voltage type high voltage variable frequency speed regulation system by using MATLAB 7.0/SIMULINK 6.0 modules.

  7. 基于双频电源技术的船舶岸电系统研究%Research of Shore-to-ship Power Supply System Based on Dual-frequency Power Supply Technology

    Institute of Scientific and Technical Information of China (English)

    李晓光; 卜佩征; 王冀星; 张海波; 王海洋

    2015-01-01

    近年来,船舶岸电技术作为港口节能减排的重要举措之一,越来越受到各地政府的重视。针对我国船舶岸电存在的变压变频、电量计量等技术难题,研究船舶岸电的双频电源技术,该技术可以为靠港船舶提供50/60 Hz 双频电源,并且能分别对这两种电制进行准确的电量计量。基于此技术又提出一种新的船舶岸电系统,该岸电系统可将我国港口的交流电变换成适合于国内外船舶不同频率、不同配电电压等级的交流电,满足不同船舶对供电电制不同的需求,供电方式灵活,增加了岸电电源的适用范围。%In recent years, more and more attention has been paid by local government to the shore-to-ship power supply technology which is an important measure of port energy-saving and emission-reduction. For some technical problems of frequency and voltage conversion and electricity metering in the shore-to-ship power supply system, the dual-frequency power supply technology is studied, this technology can offer 50/60 Hz dual-frequency power supply, and can respectively meter the two kinds of frequency electric power accurately. A new-style shore-to-ship power supply system is put forward based on this technology, the system can convert alternating current of China’s port to alternating current of different frequency and different voltage level suitable for domestic and foreign ships, which meets the power supply needs of different ships, the power supply mode is flexible, and it increases the application scope of shore power supply.

  8. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  9. Frequency standards

    CERN Document Server

    Riehle, Fritz

    2006-01-01

    Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards

  10. 浅谈RFID技术在图书馆的应用%Talking about the Application of RFID(Radio Frequency Identification) Technology in the Library

    Institute of Scientific and Technical Information of China (English)

    关晓颖

    2015-01-01

    This paper introduces the development status of RFID technology in library world, expounds the working principles and structural components of RFID, carries out an analytic demonstration of the advantages of RFID technology in its application in the library, and analyzes some problems existing in the practice of RFID technology.%介绍了RFID技术在图书馆界的发展情况,阐述了RFID的工作原理和结构组成,分析论证了RFID技术在图书馆工作中应用的优势,并对RFID技术在实践中存在的问题进行了剖析.

  11. 防爆变频器在煤矿应用中的关键技术%Key Technologies of Explosion-proof Frequency Converter Applied in Coal Mine

    Institute of Scientific and Technical Information of China (English)

    祝龙记; 张旭立

    2012-01-01

    分析了防爆变频器在煤矿井下使用过程中存在的电压等级、散热、电磁兼容性、逆变器转换效率等问题,详细介绍了解决这些问题的方法,即通过采用隔爆兼本质安全型技术和热管散热技术解决变频器的防爆和散热问题,使防爆变频器具有性能高、功能强、噪音低等特点;通过改变变频器的电路拓扑结构、改进控制策略等技术手段解决变频器的电磁兼容性和能耗问题,使防爆变频器满足煤矿生产的现代化要求.%The paper analyzed problems of voltage level, heat dissipation, EMC and conversion efficiency of inverter existed in using process of explosion-proof frequency converter in coal mine underground, and introduced methods of solving these problems in details, namely using technologies of flameproof and intrinsic safety and heat dissipation with heat pipes to solve problems of explosion-proof and heat dissipation of frequency converter, which can make explosion-proof frequency converter has characteristics of high performance, strong functions and low noise; using technical means of changing circuit topology and improving control strategy of frequency converter to solve problems of EMC and energy consumption of frequency converter, which can make explosion-proof frequency converter meet with requirements of modernization of coal mine production.

  12. A novel research approach on the dynamic properties of photogenerated charge carriers at Ag{sub 2}S quantum-dots-sensitized TiO{sub 2} films by a frequency-modulated surface photovoltage technology

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Zhang, Wei [Liaoning Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials, College of Chemistry, Liaoning University, Shenyang 110036 (China); Xie, Tengfeng; Wang, Dejun [College of Chemistry, Jilin University, Changchun 130012 (China); Song, Xi-Ming, E-mail: songlab@lnu.edu.cn [Liaoning Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials, College of Chemistry, Liaoning University, Shenyang 110036 (China)

    2013-09-01

    Graphical abstract: The changed SPV with chopping frequencies indicate the separation speeds of photogenerated charge carriers in different films. - Highlights: • Ag{sub 2}S-sensitized TiO{sub 2} films show good photoelectric responses in visible-light region. • Frequency-modulated SPV give dynamic information and evidence of Ag{sub 2}S QDSSCs’ performance. • Frequency-modulated SPV can supply complementary information in the study of Ag{sub 2}S ODSSCs. - Abstract: Ag{sub 2}S quantum-dots-sensitized TiO{sub 2} films with different amount of Ag{sub 2}S were fabricated by a successive ionic layer adsorption and reaction (SILAR) method. The separation and transport of photogenerated charge carriers at different spectral regions were studied by the frequency-modulated surface photovoltage technology. Some novel dynamic information of photogenerated charge carriers in a wide spectral range is found. The results indicate that the rate and direction of separation (diffusion) for photogenerated charge carriers are closely related to the performance of quantum-dots-sensitized solar cells (QDSSCs) based on the Ag{sub 2}S/TiO{sub 2} nano-structure.

  13. Frequency synthesiser

    NARCIS (Netherlands)

    Drago, Salvatore; Sebastiano, Fabio; Leenaerts, Dominicus Martinus Wilhelmus; Breems, Lucien Johannes; Nauta, Bram

    2016-01-01

    A low power frequency synthesiser circuit (30) for a radio transceiver, the synthesiser circuit comprising: a digital controlled oscillator configured to generate an output signal having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an

  14. 空间相干光通信中基于DSP的多普勒频移补偿技术%Compensation technology of Doppler frequency shift in space coherent optical communication using DSP

    Institute of Scientific and Technical Information of China (English)

    向劲松; 潘乐春; 张苗苗; 张孝雷

    2011-01-01

    Optical phase-locked loop(OPLL) is often used in space coherent optical communication as the traditional way to achieve the phase synchronous. But the OPLL is affected by the Doppler frequency shift, so in this paper, we use an open-loop compensation technology based on DSP to compensate the Doppler frequency shift, and apply it to a recursive demodulate system, demodulating the next data according to the previous data information. Simulation results show that the open-loop compensation technology based on DSP is able to compensate the Doppler frequency shift, and allow the space coherent optical communication system to demodulate without any optical phase-locked loop, and the performance of the system can approach the ideal status which Doppler frequency shift is completely compensated.%目前通常采用光锁相环(optical phase-locked loop,OPLL)完成空间相干光通信中的相位同步.针对光锁相环性能受空间通信终端间多普勒频移影响的不足,采用基于数字信号处理(digital singnal procesor,DSP)的开环方法补偿多普勒频移,并将开环补偿方法应用于一种递推解调系统中,根据前一时刻的数据信息进行后一时刻的数据解调.仿真结果表明:采用基于DSP的开环补偿方法可以补偿多普勒频移,使空间相干光通信系统不使用光锁相环,且性能接近多普勒频移被完全补偿的理想状态.

  15. 变频技术在发电厂的应用%Application of Frequency Conversion Technology in the Power Plant

    Institute of Scientific and Technical Information of China (English)

    司春生; 刘树昌

    2001-01-01

    Annual savings of electricity was 2650kWh by installation of Hitachi J300 frequency conversion speed regulations in the power plant, which has effectively prevented motors against trip caused by the fluctuation of voltage.%在电厂送风机、凝结水泵、疏水泵和除盐水泵等机组上加装了变频调速装置后,年节电265万kWh,并有效的防止了由于电压波动造成的电机跳闸。

  16. GPS卫星导航系统多频姿态测量技术研究%Research on GPS Satellite Navigation System Multi-frequency Attitude Determinat ion Technology

    Institute of Scientific and Technical Information of China (English)

    李献球; 甘兴利; 李隽

    2012-01-01

    GPS modernization provides a foundation for developing multi-frequency a ttitude determination receiver.To satisfy the attitude determination requiremen ts of platforms such as low orbit satellites,missiles,aircrafts and naval vess els,a general design scheme for multi-frequency attitude determination receive r is given,which is composed of antenna unit,measurement unit and attitude comp utation unit.Then,some key technologies are investigated,including real-time cycle slip detection and correction based on GPS multi-frequency combination no i se residual,and the ambiguity resolution algorithm for single epoch using geome try restriction.The computation equations and flows are described in detail.Fi nally,a static test is carried out for the GPS-based single frequency receiver and multi-frequency receiver for attitude determination.The test results indic a te that,as for the attitude determination accuracy and computation success rati o,the multi-frequency receiver shows better performance than that of the singl e-frequency receiver.%GPS全球卫星导航系统现代化工作,为多频姿态测量接收机的研制提供了基础条件。针对低轨卫星、导弹、飞机和舰艇等平台对姿态测量的使用需求,给出了由天线单元、测量单元和姿态解算单元构成的多频姿态测量接收机总体方案。研究了基于GPS多频组合噪声残差法实时探测与修复周跳、基于几何约束的单历元模糊度解算等关键技术,并给出了详细的计算方程和流程。对GPS单频定姿接收机和多频定姿接收机进行静态试验,证明后者在测姿精度和解算成功率方面都优于前者。

  17. 双音频DTMF技术在DSP系统中的实现%The implementatin of technology of dual tone multi-frequency in DSP system

    Institute of Scientific and Technical Information of China (English)

    管庆; 徐胜

    2003-01-01

    双音多频DTMF(Dual Tone Multi-Frequency)信令在全世界范围内得到广泛应用,将DTMF信令的产生与检测集成到含有数字信号处理器(DSP)的系统中,是一项较有价值的工程应用.本文给出一种成功的实现方案:首先阐述DTMF信令的产生与检测的基本原理,然后给出在TI公司定点DSP芯片TMS320C54x系列中的实现方案,最后作了实现方案的性能分析.

  18. Discussion of the Integration of Curriculum of Frequency Conversion Technology Teaching%变频技术一体化课程教学的探讨

    Institute of Scientific and Technical Information of China (English)

    范宝华

    2015-01-01

    Inverter technology is a basic course for automation specialty, is an emerging discipline, teaching has certain difficulty and learning. This article first analyzed the common problems in integrated curriculum "inverter technology", the significance and importance of the teaching of. Then expounds the specific reform measures on teaching materials, teachers, teaching content, teaching methods, teaching means and methods of assessment in the process of teaching. Practice has proved: using the new teaching method, integrated curriculum teaching new teaching methods is not only beneficial to the students' mastery of the theory of knowledge, but also for the students to improve industrial automation equipment, to adapt to the social development of industrial modernization, Shi Yingxin's assessment methods with non constant important role.%变频技术是自动化专业的基础课程,是一门不断发展的新兴学科,教与学都具有一定的难度。首先分析了变频技术一体化课程的重要性、意义和教学中存在的普遍问题。然后阐述了教学过程中对教材、教师、教学内容、教学方法、教学手段和考核方式的具体改革措施。实践证明,进行一体化课程教学采用新教学方法、新教学手段不仅有利于学生对理论知识的掌握,而且对于学生提高工业自动化设备认识,适应社会工业现代化发展、适应新的考核方式等有着非常重要的作用。

  19. 基于调频激励和细化谱分析的多频涡流检测技术研究%Research on multi-frequency eddy current testing technology based on frequency modulation excitation and zoom spectrum analysis

    Institute of Scientific and Technical Information of China (English)

    高军哲; 潘孟春; 张琦; 罗飞路; 何赟泽

    2011-01-01

    常规多频涡流检测技术在谱分析时,一般采用多个频率的正弦信号同时工作,其激励信号峰值因数较大且检测信号频谱为离散谱.文中提出了一种基于调频信号激励和检测信号细化谱分析的多频涡流检测技术,它不仅降低了激励信号峰值因数,而且检测信号频谱为连续谱.对检测信号施加Tukey窗函数改善谱图,采用Chirp-Z变换计算检测信号频谱,提高谱图的频率分辨率.定义谱图能量、谱图重心、谱图峰度和谱图偏度4个特征量应用于缺陷识别和分类.对于内部缺陷,采用谱图差峰值频率点,定量检测内部缺陷的位置.理论分析和实验结果相一致,验证了所采用方法的正确性.%In conventional multi-frequency eddy current testing (MFECT) technique, the excitation signal is synthesized synchronously from many sine signals when eddy current testing signals are analyzed in frequency domain. The crest factor of the excitation signal is rather large and the testing signal spectrum is discrete. This paper proposes a new MFECT technology, which adopts frequency modulation excitation and zoom spectrum analysis. The new technology reduces the crest factor of the excitation signal and the test signal spectrum becomes continuous. Tukey window is exerted to the test signal to improve its spectrum. Chrip-Z transform is adopted to calculate the testing signal spectrum, which heighten its frequency resolution. Spectrum energy, spectrum barycenter, spectrum kurtosis and spectrum skewness are defined to identify and classify the defects. The position of inner defects is quantitatively detected using the peak frequency point of the spectrum difference. Theoretical analysis and experimental data agree with each other, which verifies the correctness of the employed method.

  20. Physics and technology in the ion-cyclotron range of frequency on Tore Supra and TITAN test facility: implication for ITER

    Science.gov (United States)

    Litaudon, X.; Bernard, J. M.; Colas, L.; Dumont, R.; Argouarch, A.; Bottollier-Curtet, H.; Brémond, S.; Champeaux, S.; Corre, Y.; Dumortier, P.; Firdaouss, M.; Guilhem, D.; Gunn, J. P.; Gouard, Ph.; Hoang, G. T.; Jacquot, J.; Klepper, C. C.; Kubič, M.; Kyrytsya, V.; Lombard, G.; Milanesio, D.; Messiaen, A.; Mollard, P.; Meyer, O.; Zarzoso, D.

    2013-08-01

    To support the design of an ITER ion-cyclotron range of frequency heating (ICRH) system and to mitigate risks of operation in ITER, CEA has initiated an ambitious Research & Development program accompanied by experiments on Tore Supra or test-bed facility together with a significant modelling effort. The paper summarizes the recent results in the following areas: Comprehensive characterization (experiments and modelling) of a new Faraday screen concept tested on the Tore Supra antenna. A new model is developed for calculating the ICRH sheath rectification at the antenna vicinity. The model is applied to calculate the local heat flux on Tore Supra and ITER ICRH antennas. Full-wave modelling of ITER ICRH heating and current drive scenarios with the EVE code. With 20 MW of power, a current of ±400 kA could be driven on axis in the DT scenario. Comparison between DT and DT(3He) scenario is given for heating and current drive efficiencies. First operation of CW test-bed facility, TITAN, designed for ITER ICRH components testing and could host up to a quarter of an ITER antenna. R&D of high permittivity materials to improve load of test facilities to better simulate ITER plasma antenna loading conditions.

  1. Allelic frequencies of PRKAG3 in several pig breeds and its technological consequences on a Duroc × Landrace-Large White cross.

    Science.gov (United States)

    Galve, A; Burgos, C; Varona, L; Carrodeguas, J A; Cánovas, Á; López-Buesa, P

    2013-10-01

    The allelic frequencies of PRKAG3 gene (the RN gene) have been investigated in several pig breeds. R200Q mutation appear only in Hampshire pigs, whereas V199I mutation is most abundant in Iberian, Porco Celta or Bizaro, and less in breeds selected for muscularity as Duroc, Landrace and Pietrain. A thorough study of phenotypic effects of V1991 has been performed in a Duroc × Landrace-Large White cross. 199I homozygous pigs show increased pH24 values in ham homogenates and loin (0.14 and 0.16 pH units, respectively) compared to 199V homozygous ones. Meat of 199I homozygous pigs exudates 42.6% less fluid and is darker (2.46 'L'-value units). 199I homozygous pigs are fatter (4.2 mm more backfat thickness) and contain less muscle mass in ham (1.0 percentage points) and shoulder (2.7 percentage points), than 199V homozygous ones. 199I homozygous pigs contain 7.3% less protein in the belly and 8.5% more fat in shoulder muscle mass than 199V homozygous pigs. 199I homozygous pigs have also superior functional properties: better gelling (22.8% larger G' value) and emulsion capacities (14 percentage points less of total exuded fluid), and higher curing yield in the belly (6 percentage points more). These data support the adipogenic character of the V199I mutation. The advantages and disadvantages of selecting any of the two PRKAG3 alleles for position 199 are discussed.

  2. 射频识别技术在井下工具中的应用与发展%Application and Development of Petroleum Downhole Tools Based on Radio Frequency Identification Technology

    Institute of Scientific and Technical Information of China (English)

    刘清友; 张安琪; 黎伟

    2015-01-01

    为促进我国射频识别技术在智能化钻完井领域的应用与发展,解决深井、超深井勘探开发中的技术瓶颈,拓宽井下工具的使用功能,调研了射频识别技术在石油工具中的应用现状。阐述了射频识别技术的工作原理与技术特点,在非常规油气藏钻完井开发中引入射频识别技术,可大幅提高井下工具的工作效率,缩短施工周期,降低施工成本。介绍了国外射频识别技术在油田钻具监测管理、钻井扩眼工具、压裂滑套工具中的典型应用。针对射频识别技术的关键性难题,展望了该技术在未来石油装备及工具中的发展趋势,对促进该技术在石油工具智能化方面的应用具有重要意义。%To promote the application and development of RFID (radio frequency identification) technology in the field of intelligent drilling and completion in our country,and resolve the bottle-neck problems in the exploration and development of deep/ultra-deep wells,and widen the func-tional use of petroleum downhole tools,the application status of RFID technology in petroleum e-quipment and tools were investigated.The working principle and technical characteristics of RFID technology are explained in this paper.While introducing RFID technology in unconventional res-ervoirs development drilling and completion,it could greatly improve downhole work efficiency, shorten the construction period,and reduce construction cost.The typical applications of foreign RFID technology in the oilfield drilling monitoring and management,drilling reaming tools and sleeve fracturing tools are introduced.With reference to the key technical problems of RFID tech-nology,the prospect of RFID technology in the future petroleum equipment and tools are sugges-ted.This paper is of significance to promote the realization of intelligent tools in petroleum equip-ment field of our country.

  3. 基于RFID技术的科技馆导览系统研究%Research on the science and technology museum navigation system based on Radio Frequency Identifi cation technology

    Institute of Scientific and Technical Information of China (English)

    王珊珊

    2015-01-01

    基于中国科技馆RFID电子门票的应用,对基于RFID技术的科技馆导览系统进行研究。针对目前导览系统个性化服务不足、数据与信息整合度低、人机交互方式单一、科普性不够等缺点,提出了基于RFID技术的科技馆导览系统的设计原则和解决方案,以期拓展科技馆导览系统的个性化服务模式,加强对观众参观过程的引导,提升观众的参观品质。%This paper analyzes the problems related to the science and technology museum navigation system, and provides a solution for navigation system based on RFID technology, in order to develop personalized service model of the system, strengthen the guidance to the visitors, and improve the quality of the visiting.

  4. Medium-Sized Mammals around a Radioactive Liquid Waste Lagoon at Los Alamos National Laboratory: Uptake of Contaminants and Evaluation of Radio-Frequency Identification Technology

    Energy Technology Data Exchange (ETDEWEB)

    Leslie A. Hansen; Phil R. Fresquez; Rhonda J. Robinson; John D. Huchton; Teralene S. Foxx

    1999-11-01

    Use of a radioactive liquid waste lagoon by medium-sized mammals and levels of tritium, other selected radionuclides, and metals in biological tissues of the animals were documented at Technical Area 53 (TA-53) of Los Alamos National Laboratory during 1997 and 1998. Rock squirrel (Spermophilus variegates), raccoon (Procyon lotor), striped skunk (Mephitis mephitis), and bobcat (Lynx rufus) were captured at TA-53 and at a control site on the Santa Fe National Forest. Captured animals were anesthetized and marked with radio-frequency identification (RFD) tags and/or ear tags. We collected urine and hair samples for tritium and metals (aluminum, antimony, arsenic, barium, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, and thallium) analyses, respectively. In addition, muscle and bone samples from two rock squirrels collected from each of TA-53, perimeter, and regional background sites were tested for tritium, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, and total uranium. Animals at TA-53 were monitored entering and leaving the lagoon area using a RFID monitor to read identification numbers from the RFID tags of marked animals and a separate camera system to photograph all animals passing through the monitor. Cottontail rabbit (Sylvilagus spp.), rock squirrel, and raccoon were the species most frequently photographed going through the RFID monitor. Less than half of all marked animals in the lagoon area were detected using the lagoon. Male and female rock squirrels from the lagoon area had significantly higher tritium concentrations compared to rock squirrels from the control area. Metals tested were not significantly higher in rock squirrels from TA-53, although there was a trend toward increased levels of lead in some individuals at TA-53. Muscle and bone samples from squirrels in the lagoon area appeared to have higher levels of tritium, total uranium, and {sup 137}Cs than samples collected from perimeter and

  5. 变频技术在300 MW机组低压加热器疏水泵上的应用%APPLICATION OF FREQUENCY-CONVERTING TECHNOLOGY ON DRAIN PUMP FOR LP HEATER OF A 300MW UNIT

    Institute of Scientific and Technical Information of China (English)

    陈强; 刘建华; 张乐群

    2001-01-01

    The drain system of LP heater was designed as a combined operation system of step-by-step gravity drain and drain pump. When the said pump is operating at constand speed, troublesome problems, shch as higher fault rate, larger pipeline vibration, shorter time for putting LP heater into operation etc, are ubiquitous. Using frequency-converting technology, the water level in LP heater can be controlled by converting the frequency of drain pump’s power supply instead of adjustment with valves. More than one year’s operation of the retrofitted system proved that the operation of said drain pump to be stable, safe and reliable .The rate of putting LP heater into operation reaches 100% and the effect of energy-saving is obvious. The said technology has been rapidly spread in use.%300 MW机组低压加热器疏水系统设计为逐级自流和低压加热器疏水泵联合运行方式,疏水泵定速运行时普遍存在泵故障率高、管道振动大、低压加热器投入率低等问题。利用变频技术将低压加热器水位控制方式由阀门调节改为疏水泵变频控制,改造后一年多运行表明疏水泵运行稳定,安全可靠,低压加热器投入率达100%,节能显著,并很快在湛江发电厂推广使用。

  6. 数字鉴频技术在电台检测设备中的应用%Application of Digital Frequency-Detecting Technology in the Radio Tester

    Institute of Scientific and Technical Information of China (English)

    夏明飞; 夏明旗

    2011-01-01

    针对电台检测的测试需求,简述了传统的模拟鉴频技术,重点分析脉冲滤波法和微分鉴频法的数字鉴频技术,并对2种方法进行仿真运算和算法性能比较,给出了适合于手持式低功耗的电台检测设备的数字鉴频方法.仿真结果表明,该设计不仅能避免模拟电路的一致性和稳定性,而且可利用统一的音频信号处理硬件平台,提高系统设计集成度.%In order to meet the measurement demand of the radio, this paper briefly describes the traditional analog frequency-detecting technology, and analyzes the pulse filter method and differential frequency-detecting method in detail.Both of the methods were simulated and compared. Finally the method was given to suit for the portable and low power radio tester. The simulation result proved that this design can avoid the analog circuit's stability and consistence. When we make use of audio signal processing hardware platform, this design can improve the integration of the system design also.

  7. Demand as frequency controlled reserve

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Togeby, M.; OEstergaard, J.

    2008-09-15

    Using demand as frequency controlled reserve (DFR) is an emerging technology which allow demand to participate actively in maintaining the system operation without reducing the energy service delivered to the customer and without need of user interaction. The basic premise is that traditional frequency controlled reserves from power plants and interconnections with neighbouring systems can be costly, slow and not fulfil the need for future power grids with a high share of wind power and fewer central power plants, and an intention to perform flexible operation such as is landing. Electricity demands, on the other hand, have advantages as frequency reserve including fast activation speed, smooth linear activation, low expected costs, and well-dispersed in the distribution grid. The main challenge of DFR is new methods for monitoring the available capacity. This project has investigated the technology of using electricity demands for providing frequency reserve to power systems. Within the project the potential and economy of DFR compatible loads in Denmark has been investigated, control logic has been designed, power system impact has been investigated, potential business models has been evaluated and an implementation strategy has been suggested. The tasks and goals of the project have been successfully accomplished based on which the conclusion and future recommendation are made. This project has developed the DFR technology that enables electricity demands to autonomously disconnect or reconnect to the grid in response to system frequency variations. The developed DFR technology is proved to be a promising technology from several perspectives. Technically, using DFR is feasible to provide reserves and enhance power system frequency control, while fulfilling technical requirements such as linear activation (or reconnection) according to frequency (or time). Environmentally, the DFR technology is pollution free in contrast to traditional reserves from generation

  8. 高频焊接钢管焊缝的超声波自动检测工艺%Automated Ultrasonic Inspection Technology for Weld Seam of High Frequency Welding Pipes

    Institute of Scientific and Technical Information of China (English)

    张志刚

    2011-01-01

    在高频焊接钢管焊缝自动超声波检测的实际工作中,精确的焊缝跟踪较难实现,易影响检测的可靠性.通过对超声波检测技术进行分析,利用6 dB声束全壁厚覆盖区进行检测,提出了一套超声波检测新工艺.实践证明:该工艺可以在焊缝跟踪不精确的情况下实现可靠的超声波检测,为高频焊接钢管焊缝自动超声波检测提供了一套有效的检测方法.%During the automated ultrasonic inspection of weld seam of high frequency welding(HFW) pipes,it is very difficult to track the weld seam accurately, which will affect the reliability of inspection easily. Through the analysis of ultrasonic inspection techniques, and inspecting with 6 dB sound beam full wall thickness overlap area, a new set of ultrasonic inspection technology was put forward. Practice showed that, in the event of inexact seam track, the technology can assure the reliable inspection result, and provided a effective method for the automated ultrasonic inspection of weld seams of HFW pipes.

  9. Application of Rotor Frequency Conversion Technology to Electric Control System of Mine Hoist%转子变频技术在矿井提升机电控系统中的应用

    Institute of Scientific and Technical Information of China (English)

    刘连君; 张传明; 李艳辉; 李军

    2011-01-01

    提升机TKD高压交流电控系统的节能变频改造一般选用高压变频方案,而矿井交流提升机普遍使用中小功率电机,高压变频的成本较高、性价比低,因此提出一种采用高压交流绕线电机转子变频调速控制系统的节能变频改造方案,将高压交流绕线电机的定子短封,使用低压变频器对电机的转子供电,实现高压交流绕线电机的变频调速控制。首先在山东新矿集团华恒公司副斜井提升机进行了工业运行试验,对电机性能进行测试分析,并统计了系统的节能效果,结果表明,电机的综合效率没有明显变化,功率因数提高到0.95,节电率效果显著。%The energy saving and frequency conversion reconstruction of the TKD high voltage AC electric control system for the mine hoist generally would adopt a high voltage frequency conversion alternative.In fact,the mine AC hoist would apply a medium or small power motor generally.The high voltage frequency conversion would have a high cost and a low performance and cost ratio.Therefore an energy saving and frequency conversion reconstruction alternative of the stator frequency conversion control system for the high voltage AC winding motor was provided.The stator would be short sealed for the high voltage AC winding motor.The low transformer would be applied to supply the power for the stator of the motor.Thus the frequency converted speed control could be realized for the high voltage AC winding motor.A industrial trial of the frequency conversion technology was first conducted on the hoist applied to the mine auxiliary inclined shaft of Huanheng Mine,Shandong Xinwen Coal Mining Group.The measurement and analysis were conducted on the performances of the electric motor and there was a statistic on the energy saving effect of the system.The results showed that the comprehensive efficiency of the electric motor had no obvious change,but the power factor was improved by 0.95 and the power

  10. Determination of the exposure to electromagnetic fields arising from radiofrequency identification technology (RFID) application. Final report; Bestimmung der Exposition gegenueber elektromagnetischen Feldern, die durch den Einsatz von Radio Frequency Identification (RFID) Technologien entstehen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Gernot; Ueberbacher, Richard; Cecil, Stefan; Escorihuela-Navarro, Ana; Sainitzer, David; Weinfurter, Andreas [Seibersdorf Labor GmbH, Seibersdorf (Austria). Fachbereich EMV, Geschaeftsfeld EMC and Optics

    2012-08-15

    antennas closer than 20 cm. Regarding UHF (868 MHz) and microwave (2,45 GHz) reader devices it was demonstrated that exposure above the basic restriction is not to be expected as long as a minimum distance to the antennas of 10 cm - 20 cm is maintained. Concerning exposure from currently widest deployed Electronic Article Surveillance (EAS) technology also differences between technologies become obvious. While the numerous measurements and computations carried out did not give indications that radio frequency (RF)-EAS devices (operating frequency range typically 7,5-8,9 MHz) cause exposure above the basic restrictions defined in ICNIRP 1998, it could be demonstrated that for acoustomagnetic (AM)-EAS systems (operating frequency 58 kHz) exposure above the ICNIRP 1998 basic restrictions is possible, when approaching the antenna very closely, i.e., at unusual short distances of less than a few centimeters between the trunk and/or the head and the antenna. With respect to the assessment of the exposure caused by the RFID- and EAS devices with operating frequencies less than 10 MHz (particularly close to and below 100 kHz), it must be noted that the assessment summarized above was carried out based on the ICNIRP guidelines published in 1998, i.e., that the basic restriction in terms of current density was applied only to central nervous (CNS) tissue. It must be expected that the application of the new assessment concept recently published by ICNIRP 2010, which is based of induced electric field strength inside the tissue and which provides now also limits for all body tissues and not only for CNS tissue, may lead to significant different assessment results and conclusions for the mentioned device categories. Regarding possible electromagnetic interference with cardiac pacemakers, again RFID- and EAS-devices with working frequencies 58 kHz and 120 kHz and large (e.g., floor standing) antennas showed up to have the highest potential for interference compared to the other

  11. Newnes communications technology handbook

    CERN Document Server

    Lewis, Geoff

    1994-01-01

    Newnes Communications Technology Handbook provides a discussion on different topics relevant to communications technology. The book is comprised of 39 chapters that tackle a wide variety of concern in communications technology. The coverage of the text includes technologies, such as analog digital communications systems, radio frequency receiver, and satellite systems. The book also discusses some methods and techniques used in communications technology, including mixer signal processing, modulation and demodulation, and spread spectrum techniques. The text will be of great use to engineers, t

  12. Radio Frequency Identification

    Indian Academy of Sciences (India)

    V Rajaraman

    2017-06-01

    Radio Frequency Identification (RFID) has been around sinceearly 2000. Its use has currently become commonplace as thecost of RFID tags has rapidly decreased. RFID tags have alsobecome more ‘intelligent’ with the incorporation of processorsand sensors in them. They are widely used now in manyinnovative ways. RFIDs are an integral part of Internet ofThings (IOT) and IT systems of smart cities. In this article,we introduce the technology used by RFID systems, illustratetheir use in several applications, and discuss problems of privacyand security when they are used.

  13. Research of Low-Voltage Frequency Conversion Shore Connection Technology in Qinhuangdao Port%秦皇岛港低压变频岸电技术方案研究

    Institute of Scientific and Technical Information of China (English)

    李婷

    2012-01-01

    为进一步实现港口节能减排,秦皇岛港提出低压变频岸电技术方案。分析国内外港口采用的岸电技术与发展趋势,结合秦皇岛港煤五期码头到港主力船型、码头供电设施等情况,进行低压变频岸电方案研究。提出切实可行的岸电设计方案,并分析优缺点,为该港岸电最终方案择选提供可靠的方案支撑。可持续发展是秦皇岛港中远期提升煤炭运输市场竞争力的需要。%In order to realize further power-saving and exhaustion-reducing of Port, a technical plan of low-voltage frequency conversion is put forward by Qinhuangdao Port. The technology and development trend of shore connection in domestic and foreign ports is analyzed. Low-voltage frequency conversion shore connection project is researched , combined with the main ship type in port and connection supply facilities of the wharf in QHD port. The practical and feasible shore connection scheme is proposed, and the advantages and disadvantages of the scheme is analyzed for providing reliable solutions to support to the final choice. The project is the need of raising coal transport market competitiveness in long-term for Qinhuangdao Port.

  14. Analysis on High-Frequency Global Communications System Technology of US Air Force%美国空军短波全球通信系统技术分析

    Institute of Scientific and Technical Information of China (English)

    鞠茂光; 刘尚麟

    2013-01-01

    HFGCS (High Frequency Global Communications System) is a highly-automated, HF communication system and links US Air Force C2 (command and control) functions with globally-deployed strategic & tactical airborne platforms. This paper describes the basic situation of HFGCS, and analyzes the IP routing, HF station control signaling and communication data IP bearing, HF wireless IP protocol, end-to-end secure interoperability protocol and other technical characteristics of HFGCS, amd finally it gives the enlightenment for high-frequency communication network development in China, proposes some suggestions in strengthening the research of unified scheduling of HF station transceiver station resource, HF communication wireless IP protocol, HF communication information distribution, HF end-to-end secure communication interoperability technology, and each level should use IP technology, maintain the sustainability of HF communication development.%  短波全球通信系统 HFGCS,是高度自动化短波通信系统,为美国空军全球作战飞机部署和战略任务提供通信链路。这里首先介绍了 HFGCS 基本情况,然后分析了 IP 路由、短波台站控制信令和通信数据 IP 承载、短波无线 IP 协议、短波端到端保密互通等 HFGCS 具有特点的技术,最后给出了对中国短波通信网络发展的启示,建议加强短波台站收发信台资源统一调度、短波通信无线 IP 协议、短波通信信息分发、短波端到端保密通信等技术应用研究,各个层次都使用 IP 技术体制,保持短波通信网发展的可持续性。

  15. Study on Dual-Ultrasonic Vibrator Frequency Tracking Technology Based on FPGA%基于FPGA双超声振子频率跟踪技术的研究

    Institute of Scientific and Technical Information of China (English)

    杨军; 郭钟宁; 姚震; 温凯林

    2015-01-01

    为解决传统单超声、无超声生物质压缩技术的不足,提出了利用单个超声电源同时驱动两个超声振子的新方法,即双超声同步压缩生物质技术. 结合单超声振子谐振特性,在分析双超声振子谐振特性的基础上,得出双超声振子并联后的谐振特性可等效为单超声振子的谐振特性. 采用基于FPGA的最大电流法和相位差法相结合的方法实现频率自动跟踪功能,设计了电压电流相位采样电路和电流大小采样电路. 通过双超声同步压缩生物质实验,验证了该频率跟踪方式的有效性.%In order to solve the disadvantages of the technology of traditional single ultrasonic and non-ultrasonic vibration-assisted pelletizing of biomass ,a new method of dual-ultrasonic vibrator driven by a single power supply is presented ,which is named dual-ultrasonic synchronous vibration-assisted pelletizing of biomass technology. Through the analysis of the resonance characteristics of dual-ultrasonic vibrator compared with that of single ultrasonic vibrator ,it is concluded that the characteristics of dual-ultrasonic vibrator can be equivalent to the characteristics of single ultrasonic vibrator. The compound automatic frequency tracking method of combining the maximum current and the difference of current and voltage phase based on FPGA is realized. Voltage and current phase sampling circuit and current sampling circuit were designed. The effectiveness of the compound frequency tracking method is verified by the experiment of dual-ultrasonic synchronous vibration-assisted pelletizing of biomass.

  16. Fast frequency divider circuit using combinational logic

    Science.gov (United States)

    Helinski, Ryan

    2017-05-30

    The various technologies presented herein relate to performing on-chip frequency division of an operating frequency of a ring oscillator (RO). Per the various embodiments herein, a conflict between RO size versus operational frequency can be addressed by dividing the output frequency of the RO to a frequency that can be measured on-chip. A frequency divider circuit (comprising NOR gates and latches, for example) can be utilized in conjunction with the RO on the chip. In an embodiment, the frequency divider circuit can include a pair of latches coupled to the RO to facilitate dividing the oscillating frequency of the RO by 2. In another embodiment, the frequency divider circuit can include four latches (operating in pairs) coupled to the RO to facilitate dividing the oscillating frequency of the RO by 4. A plurality of ROs can be MUXed to the plurality of ROs by a single oscillation-counting circuit.

  17. Investigation on the application of radio frequency identification technology in the pasteurization of surgical devices%无线射频识别技术在手术灭菌器械管理中的应用研究

    Institute of Scientific and Technical Information of China (English)

    马俊; 汤维娟; 侯斌

    2014-01-01

    目的:调查无线射频识别( RFID)技术在我院使用的现状,为进一步推广使用提供依据。方法选取2013年6月本院消毒供应中心、手术室及病房262名工作人员,采取自制问卷进行调查,问卷Cronbach′s α系数为0.824。结果 RFID技术使用最多的为消毒供应中心及手术室。66.96%的使用者认为RFID“操作简便”,80.18%认为“使器械管理更规范”,80.36%认为RFID“能确保每个环节质量”,75.9%认为RFID技术的“器械包追溯功能”给临床带来的帮助最大,71.4%认为RFID技术优于传统器械管理在于“信息核对准确”。另外,RFID技术还需要在速度、信息上传点、标签管理等方面进行改进。结论 RFID技术能增加规范化管理,提升工作效率,保证工作质量,在临床使用取得良好的效果。%Objective To investigate the application of radio frequency identification ( RFID) in clinical practice in our hos-pital, so as to provide evidence for further extension of FRID technology.Methods Two hundred and sixty-two nurses from the central pasteurization and supply center ( CSSC) , the surgical suites and wards of the hospital in June 2013 were surveyed by a questionnaire developed by ourselves.The Cronbach′s αof the questionnaire was 0.824.Results FRID technology was used most frequently in the central pasteurization and supply center and surgical suites.66.96%of the people thought RFID was easy to operate, 80.18%of them held that it made surgical management more standard, and 80.36%agreed that the FRID technology could ensure the quality of all the links in the work.75.9%of the people surveyed had the opinion that the tracing function of the surgical kit inherent in the FRID tech-nology was most helpful to clinical work.And 71.4% of the people thought the superiority of RFID over conventional surgical device management lied in the accuracy of information check.However, further

  18. Low-frequency characteristics extension for vibration sensors

    Institute of Scientific and Technical Information of China (English)

    杨学山; 高峰; 候兴民

    2004-01-01

    Traditional magneto-electric vibration sensors and servo accelerometers have severe shortcomings when used to measure vibration where low frequency components predominate. A low frequency characteristic extension for velocity vibration sensors is presented in this paper. The passive circuit technology, active compensation technology and the closedcycle pole compensation technology are used to extend the measurable range and to improve low frequency characteristics of sensors. Thses three types of low frequency velocity vibration sensors have been developed and widely adopted in China.

  19. Practices of efficient high frequency dewatering screen technology in dry discharge of tailings%高效高频脱水筛在尾矿干排处理中的应用实践

    Institute of Scientific and Technical Information of China (English)

    李永亭; 张云龙

    2016-01-01

    The paper sets forth the feasibility of the application of efficient high frequency dewatering screen in dry discharge of tailings , and it has been successfully applied in one gold mine and obtained a dry tailings pile of which the water content is less than 15%.The paper introduces in detail the technical flowsheet and production index of this processing technology in the gold mine ,comprehensively analyzes the running cost and economic benefits of the dewatering screen .Practices prove that this technology requires low investment and low running cost ,renders high wa-ter recovery and prominent benefits ,and it can recover cyanide to the utmost .%阐述了采用高效高频脱水筛处理尾矿的可行性,并在某金矿的尾矿处理中得到了成功应用,最终可得到含水量小于15%的干堆尾矿.该文详细介绍了高效高频脱水筛处理某金矿尾矿的工艺流程和生产指标,且对其运行成本和经济效益进行了综合分析.实践证明,该尾矿处理工艺节省了投资费用,降低了运行成本,提高了回水率,经济效益显著,并可以最大限度地回收利用尾矿废水中的氰化物.

  20. 基于射频技术的野战物资管理系统设计与应用%Design and application of field material management system based on radio frequency technology

    Institute of Scientific and Technical Information of China (English)

    崔维斌; 吴天顺; 郭平彩; 马红京; 金晓芳

    2015-01-01

    目的:设计一种能够满足野战储备物资保障需要的野战物资管理系统,利用射频识别(RFID)技术建立能快速、准确、高效和智能的野战物资出入库管理平台。方法:采用RFID、局域无线网覆盖等计算机技术对野战仓库物资管理的全过程进行自动化数据采集,通过科学编码对物品的批次、保质期等进行科学管理。结果:智能化新技术在野战仓库管理中的研究和应用,快速实现了“三分四定”分组管理的要求。保证野战仓库管理各个环节数据输入的速度和准确性,确保及时准确地掌握库存真实数据,合理控制野战库存。结论:RFID技术的应用实现了野战物资快速化、自动化和智能化管理,提高了部队的后勤保障能力。%Objective:A material management system is design to meet the needs of field reserve materials security. An out of storage management platform in field supplies can be established by radio frequency identification (RFID) technology which is rapid, accurate, efficient, capable of intelligent. Methods:RFID, local area wireless network coverage and other computer technology are used on automated data acquisition during the whole process of material management. It ensures scientific management through scientific coding of goods by batch shelf of life in field warehouse. Results: Research and application of new intelligent technology in warehouse management system may help to achieve rapid implementation of grouping management requirements. It also ensure the speed and accuracy of data input in all aspects of warehouse management, so that the real inventory data may be mastered on time and accurately, and a reasonable field inventory be controlled. Conclusion: The field material management become quick, automatic and intelligent by using RFID. It can improve the logistics support ability of the army.

  1. Comparative investigation of power control of axial blowers for liquefiers and recirculation coolers: Phase controller, frequency converter, transformers, EC technology; Vergleich der Leistungsregelung von Axialventilatoren fuer Verfluessiger und Rueckkuehler: Phasenanschnittregler, Frequenzumformer, Transformatoren, EC Technik

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, G. [Hans Guentner GmbH, Fuerstenfeldbruck (Germany)

    2003-07-01

    Phase controllers are well suited for liquefaction pressure control, and energy savings are higher than with blower shut-off. They emit noise in the 300 Hz range and need an additional acoustic filter if noise reduction in part-load operation is required. Frequency controllers with all-terminal sinusoid filters have a higher saving potential at 40-80 percent of the volume flow as compared to phase controllers. Noise is significantly lower than in phase controllers, even with acoustic filters. The best performance was obtained with EC technology, which had the highest energy savings and noise levels similar to transformer control, which was hitherto considered to be the best option. (orig.) [German] Phasenanschnittregler sind zur Verfluessigungsdruckregelung gut geeignet und bieten ein groesseres Energieeinsparpotential als die Methode der Ventilatorabschaltung. Wenn die Schallreduzierung im Teillastbereich wichtig ist, sind sie wegen der stoerend wirkenden 300 Hz Tonanteilen nicht geeignet. Hier kann ein zusaetzlicher Geraeuschfilter groesstenteils Abhilfe schaffen. Frequenzregler mit allpoligem Sinusfilter haben deutliche Einsparpotentiale im Bereich von 40% bis 80% des Volumenstroms gegenueber den Phasenanschnittreglern. Die Schallreduzierung wirkt bis in die unteren Drehzahlbereiche und liegt deutlich unter den Werten der Phasenanschnittsteuerung mit Geraeuschfilter. Den hoechsten Gesamtwirkungsgrad ueber den ganzen Luftfoerderbereich liefert die getestete EC-Technik. In allen Betriebspunkten ist somit die hoechste Energieersparnis gegeben. Die Schallreduzierung ist gleichwertig mit den Ergebnissen der Transformatorregelung, die bisher als geraeuschlos bestes Verfahren eingesetzt wurde. (orig.)

  2. Frequency conversion of structured light.

    Science.gov (United States)

    Steinlechner, Fabian; Hermosa, Nathaniel; Pruneri, Valerio; Torres, Juan P

    2016-02-15

    Coherent frequency conversion of structured light, i.e. the ability to manipulate the carrier frequency of a wave front without distorting its spatial phase and intensity profile, provides the opportunity for numerous novel applications in photonic technology and fundamental science. In particular, frequency conversion of spatial modes carrying orbital angular momentum can be exploited in sub-wavelength resolution nano-optics and coherent imaging at a wavelength different from that used to illuminate an object. Moreover, coherent frequency conversion will be crucial for interfacing information stored in the high-dimensional spatial structure of single and entangled photons with various constituents of quantum networks. In this work, we demonstrate frequency conversion of structured light from the near infrared (803 nm) to the visible (527 nm). The conversion scheme is based on sum-frequency generation in a periodically poled lithium niobate crystal pumped with a 1540-nm Gaussian beam. We observe frequency-converted fields that exhibit a high degree of similarity with the input field and verify the coherence of the frequency-conversion process via mode projection measurements with a phase mask and a single-mode fiber. Our results demonstrate the suitability of exploiting the technique for applications in quantum information processing and coherent imaging.

  3. 正交频分复用技术及其在4G移动通信中的应用%Orthogonal Frequency Division Multiplexing Technology and Its Application in 4 G Mobile Communication

    Institute of Scientific and Technical Information of China (English)

    刘巧平; 李艳萍

    2014-01-01

    正交频分复用( OFDM)技术是一种特殊的多载波数字调制技术。由于OFDM的各个子载波存在正交性,极大地利用了频谱资源,所以在一定程度上缓解了未来频谱资源紧缺的问题;OFDM有良好的抗码间干扰能力和对抗频率选择性衰落,能够适应未来无线通信无失真高速数据传播的要求;各个子信道的调制和解调能用FFT和IFFT实现,因而能够满足无线通信系统中的业务要求。文中首先介绍了OFDM技术的基本原理,接着阐述了它的优势以及需要克服的缺陷,再分析了4G移动通信技术的特点,最后讨论了OFDM技术在4G移动通信系统中的应用。%OFDM (Orthogonal Frequency Division Multiplexing) is a special kind of multi-carrier digital modulation technique. Each OFDM subcarrier orthogonality exists,great using of spectrum resources,to a certain extent,ease the problem of shortage of spectrum re-sources in the future. OFDM has a good ability to resist intersymbol interference and fight against frequency selective fading,able to adapt to the future wireless high-speed data transmission without distortion. Each channel modulation and demodulation with FFT and IFFT is easy to implement,and thus can satisfy the requirements for the business in the wireless communication system. In this paper,introduce the key techniques of OFDM,describe the advantages of OFDM and the need to overcome the defects,and then analyze the characteristics of 4G mobile communication technology,finally discuss the application of OFDM in 4G mobile communication system.

  4. 采用低频配置的新型胎压监测系统设计%DESIGN OF A NEW TIRE PRESSURE MONITORING SYSTEM CONFIGURED BY LOW-FREQUENCY TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    李艳华; 肖文光

    2013-01-01

    在分析胎压监测系统工作原理的基础上阐述了手动配置轮胎压力传感器的不足,表现为气压降低、反复充气、效率低等方面。采用高、低频通信技术,设计实现了一种新的直接式胎压监测系统。该系统采用胎压专用传感器SP37和双模无线接收器MC33596分别完成轮胎内部信息的检测、发送和接收,通过低频触发实现各轮胎传感器 ID 的一键自动配置,软件上采用动态随机延时算法和节能策略,降低了多个传感器发生连续数据冲突的概率,延长了系统使用寿命。实际测试表明,该系统安装配置操作方便,跑车接收成功率可达到90%以上,具有很好的市场应用前景。%According to the working principle of tire pressure monitoring system, the lack of manual configuration is elaborated for tire pressure reduced, repeatedly inflated, low efficiency, etc. A kind of new direct tire pressure monitoring system is designed and implemented by using high and low frequency communication technology. In the system, the internal information of tires is detected, transmitted and received by dedicated sensor SP37 and wireless receiver MC33596. The tire sensor ID is automatically configured by low-frequency trigger. In the software design, the dynamic delay algorithm and the energy saving policy not only reduce the probability of continuous data conflict among sensors, but also extend the system life. The actual test result shows that the system can be installed and configured conveniently with high reception success rate up to more than 90%and good market prospects.

  5. 射频超声技术定量评估陕西地区正常儿童颈部动脉的研究%Radio frequency ultrasound technology to quantitatively assess of normal children In Shaanxi

    Institute of Scientific and Technical Information of China (English)

    李安茂; 冯晓蕾; 刘婷; 张婕; 白强; 李华; 陈广生

    2013-01-01

    【Objective】 To quantitative evaluat the normal children carotid artery intima-media thickness(IMT) and wall elastic various parameters of the salary range,and provide normal reference data for atherosclerosis early diagnosis and childhood intervention in Shaanxi. 【Methods】The quality intima-media thickness (QIMT)and quality arterial stiffness (QAS)of ultrasound radio frequency(RF) technology were applied for 150 normal children volunteer to obtain bilateral carotid intima-media thickness IMT,compliance index (distend compliance DC.conform compliance CC) and stiffness index (augmentation index AIX, a coefficient, βcoefficient, pulse wave velocity PWV) , parameters childhood range. 【Results】 1) Normal children aged 7 ~ 15 in Shaanxi had IMTC441. 483±85. 126)ntn,DC(0. 077±0. 030)mm2/kPa,CC(2. 290 ± 0. 952) mm2/kPa,AIX(-2. 804±2. 449),α(l. 453 + 0. 519),β(3. 002±l. 050),PWV(3. 650±0. 558) m/s. 2)Carotid artery between the right and left sides,between the different gender carotid parameters showed no significant differences. 【Conclusion】Application of radio frequency ultrasound technology can accurately provide normal childhood common carotid artery intima-media thickness IMT,vascular elastic parameter,and scientific basis for intervention in the prevention of arteriosclerosis in Shaanxi area.%[目的]定量评估陕西地区正常儿童双侧颈部动脉内中膜厚度及管壁弹性各项参数的大致范围,为动脉粥样硬化早期诊断和儿童期干预提供正常参考数据. [方法]对150例正常儿童志愿者应用超声射频信号血管内中膜分析技术QIMT及超声射频信号动脉僵硬度分析技术QAS获取双侧颈动脉的内中膜厚度(IMT)、顺应性指标(膨胀系数DC、顺应系数CC)及僵硬度指标(反射波增强指数AIX、a系数、β系数、脉搏波传导速度PWV),确定各项参数儿童期的大致范围. [结果]1)陕西地区7~15岁正常儿童IMT(441.483±85.126)μm,DC(0.077±0.030) mm2/k

  6. Analysis of Evaluation Technology of Insulation Systems for High Voltage Frequency Conversion Motor%高压变频电机绝缘结构评价技术解析

    Institute of Scientific and Technical Information of China (English)

    黄慧洁

    2014-01-01

    Evaluation technology of the insulation systems for high voltage frequency conversion motor was introduced, including thermal evaluation, acceptance test for mainwall insulation systems, and qualification tests for mainwall insulation systems, turn insulation systems, and stress control systems. It analyzed the difficulties met in electrical evaluation of the insulation systems, such as the unknown machine terminal voltages waveshape arising from converter operation, no reference systems can be used in mainwall insulation systems qualification tests, no test equipments to simulate the actual running situation of insulation systems. Methods to solve these problems were also discussed for reference.%介绍了高压变频电机绝缘结构评价技术,包括热评价、主绝缘认可试验及对主绝缘、匝间绝缘、应力控制和防晕结构的鉴别试验。讨论了目前高压变频电机绝缘结构电评价过程中遇到的电机运行时可能出现的端电压波形未知、主绝缘鉴别试验无基准结构可参考、难以获得完全模拟实际情况的电源条件等问题,并分析了解决这些问题的对策,供高压变频电机制造商和用户参考。

  7. Research on Frequency Calibration Technology of Low-Speed Transmission in Troposcatter Channel%散射信道下低速传输的校频技术研究

    Institute of Scientific and Technical Information of China (English)

    周现国; 李雪华; 徐志平

    2012-01-01

    Usually,phased lock loop( i. e. PLL) and other auxiliary methods are adopted in carrier recovery technology, but its fre- quency tracking range is seriously restricted,which means it could be easily out of lock. Therefore,PLL is usually not effective for low bit rate troposphere scatter communication. In order to solve the above problem, a estimation about carrier frequency error based on CORDIC algorithm and rectifying algorithm are presented,whose anti-noise performance is simulated completely with Matlab. The fre- quency error estimation and rectifying algorithm is implemented in Altera EP1C20F32417,and the test results are presented.%载波恢复技术通常是采用锁相环(PLL)和其他辅助手段提取载波,但锁相环的频率捕获范围受信噪比的制约,低信噪比下捕获范围小且容易失锁。对于散射信道,锁相环机制往往难以奏效。针对此问题,提出了一种新的载波频差估计和矫正方法,并借助Matlab工具对该算法的抗噪声性能进行了仿真,采用Altera公司的EPlC20F32417硬件实现了该频差估计和矫正算法,测试结果满足散射通信系统要求,可考虑应用于工程中。

  8. 基于PLC的微灌变频控制系统的设计与应用%Design and Application of Frequency Conversion Control System for Micro-irrigation Based on PLC Technology

    Institute of Scientific and Technical Information of China (English)

    李浩; 李金山; 段福义; 韩启彪; 孙秀路; 孙浩; 陈震

    2015-01-01

    Now in China ,the automation technology for water-saving irrigation in field is relatively backward .A PLC micro-irrigation frequency conversion control system is designed to save water and energy ,and give the flexible irrigation schemes ,as well as to give friendly man-machine interface for easy to operation .This control system ,by means of motor frequency conversion ,adjusts the wa‐ter pump to make sure that the micro-irrigation system runs steadily under set pressure .The touch screen's real-time display ,moni‐tor and control of the various working parameters make the choice of irrigation plans flexible .Field tests show that this system has favorable interface ,this system can face the needs of the micro-irrigation system under different pressures ,and this system has flexi‐ble irrigation plans ,so this system can save water .Compared with the traditional constant pressure irrigation ,this system saves en‐ergy for the frequency conversion control of the motor .%我国田间节水灌溉自动化技术相对落后,为增加节水节能效率,针对农业灌溉过程中,灌溉系统、灌溉方案的选择缺乏灵活性,缺乏友好的人机交互界面,操作复杂等情况,研究并设计了基于PLC技术的微灌变频控制系统。该控制系统通过电动机变频调速的方法,调节水泵运行工况,从而保证微灌系统在设定压力下稳定运行,并通过触摸屏实时显示、监测和控制系统运行的各工况参数,提高了作物灌溉方案选择的灵活性。田间试验表明,该系统人机界面良好,能够较好地满足微灌系统不同压力的需要,并可以灵活设定和选择灌溉方案,达到节水灌溉的目的。同时由于电机的变频控制具有较好的节能作用,与传统恒压灌溉的方式比,进一步降低了能源的浪费。

  9. Overview of the Advanced High Frequency Branch

    Science.gov (United States)

    Miranda, Felix A.

    2015-01-01

    This presentation provides an overview of the competencies, selected areas of research and technology development activities, and current external collaborative efforts of the NASA Glenn Research Center's Advanced High Frequency Branch.

  10. High Energy Single Frequency Resonant Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...

  11. Thermal-Diffusivity-Based Frequency References in Standard CMOS

    NARCIS (Netherlands)

    Kashmiri, S.M.

    2012-01-01

    In recent years, a lot of research has been devoted to the realization of accurate integrated frequency references. A thermal-diffusivity-based (TD) frequency reference provides an alternative method of on-chip frequency generation in standard CMOS technology. A frequency-locked loop locks the

  12. Thermal-Diffusivity-Based Frequency References in Standard CMOS

    NARCIS (Netherlands)

    Kashmiri, S.M.

    2012-01-01

    In recent years, a lot of research has been devoted to the realization of accurate integrated frequency references. A thermal-diffusivity-based (TD) frequency reference provides an alternative method of on-chip frequency generation in standard CMOS technology. A frequency-locked loop locks the outpu

  13. Radio Frequency Based Water Level Monitor and Controller for ...

    African Journals Online (AJOL)

    Radio Frequency Based Water Level Monitor and Controller for Residential Applications. ... Nigerian Journal of Technology ... This paper elucidates a radio frequency (RF) based transmission and reception system used to remotely monitor ...

  14. Frequency noise in frequency swept fiber laser

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2013-01-01

    This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto...

  15. Frequency noise in frequency swept fiber laser.

    Science.gov (United States)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2013-04-01

    This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto- optical modulators and forward propagating Brillouin scattering appear in the spectrum.

  16. Nanometer frequency synthesis beyond the phase-locked loop

    CERN Document Server

    Xiu, Liming

    2012-01-01

    This text presents a latest technology in frequency synthesis. The technology includes three key components: Time-Average-Frequency, Flying-Adder architecture, and Digital-to-Frequency converter. The coverage presents the case, through real application examples, that this Flying-Adder technology creates a new frontier for modern IC design. In so doing, it also discusses the weaknesses of current frequency synthesis techniques in dealing with certain problems in modern IC design. The result is a complete picture of this technology for professional design engineers, researchers, and advanced students.

  17. W频段卫星通信中正交频分复用技术的误码性能分析%Bit error rate analysis of orthogonal frequency division multiplexing technology in W-band satellite communication

    Institute of Scientific and Technical Information of China (English)

    赵乐; 宋爱民; 刘剑; 薛斌; 郭兴阳

    2015-01-01

    针对传统的卫星通信频段( C频段、Ku频段、Ka频段)应用逐渐趋于饱和的问题,研究了更高的W频段卫星通信。该频段带宽更宽,可以支持更高的数据传输速率,同等条件下天线尺寸更小并可获得更大的天线增益。正交频分复用技术具有很高的频带利用率,适合于高速数据传输,在W频段具有很好的应用前景。参照“IKNOW”项目中的链路预算,采用固态功放的Rapp模型,对OFDM技术应用在W频段卫星通信中的误码性能进行了仿真分析。仿真结果表明:在考虑功放非线性时,存在一个最佳的输入功率补偿点,使OFDM系统的误码率最低,并且发射功率越高,最佳补偿点对应的误码率越低。%Since traditional band applications ( C-band, Ku-band, Ka-band) for satellite communication will gradually tend to be saturated, the higher W-band was studied. W-band has a wider bandwidth, supports a higher data rate, acquires a smaller equipment size and a bigger antenna gain under the same conditions. Orthogonal Frequency Division Multiplexing ( OFDM) technology has a high spectrum efficiency, which makes it be suitable for high data rate transmission, so it has a good application prospect in W-band. Referring to the link budget of “IKNOW” project and using the Rapp model of solid-state power amplifier, the Bit Error Rate ( BER) of OFDM in W-band was simulated and analyzed. The simulation results show that there is a best input power backoff point which makes the BER be lowest when the nonlinear power amplifier is taken in account, and the higher the transmission power is, the lower the BER of the best input power backoff point will be.

  18. Communications technology

    Science.gov (United States)

    Cuccia, C. Louis; Sivo, Joseph

    1986-01-01

    The technologies for optimized, i.e., state of the art, operation of satellite-based communications systems are surveyed. Features of spaceborne active repeater systems, low-noise signal amplifiers, power amplifiers, and high frequency switches are described. Design features and capabilities of various satellite antenna systems are discussed, including multiple beam, shaped reflector shaped beam, offset reflector multiple beam, and mm-wave and laser antenna systems. Attitude control systems used with the antenna systems are explored, along with multiplexers, filters, and power generation, conditioning and amplification systems. The operational significance and techniques for exploiting channel bandwidth, baseband and modulation technologies are described. Finally, interconnectivity among communications satellites by means of RF and laser links is examined, as are the roles to be played by the Space Station and future large space antenna systems.

  19. VCO PLL Frequency Synthesizers for Spacecraft Transponders

    Science.gov (United States)

    Smith, Scott; Mysoor, Narayan; Lux, James; Cook, Brian

    2007-01-01

    Two documents discuss a breadboard version of advanced transponders that, when fully developed, would be installed on future spacecraft to fly in deep space. These transponders will be required to be capable of operation on any deepspace- communications uplink frequency channel between 7,145 and 7,235 MHz, and any downlink frequency channel between 8,400 and 8,500 MHz. The document focuses on the design and operation of frequency synthesizers for the receiver and transmitter. Heretofore, frequency synthesizers in deep-space transponders have been based on dielectric resonator oscillators (DROs), which do not have the wide tuning bandwidth necessary to tune over all channels in the uplink or downlink frequency bands. To satisfy the requirement for tuning bandwidth, the present frequency synthesizers are based on voltage-controlled-oscillator (VCO) phase-locked loops (PLLs) implemented by use of monolithic microwave integrated circuits (MMICs) implemented using inGaP heterojunction bipolar transistor (HBT) technology. MMIC VCO PLL frequency synthesizers similar to the present ones have been used in commercial and military applications but, until now, have exhibited too much phase noise for use in deep-space transponders. The present frequency synthesizers contain advanced MMIC VCOs, which use HBT technology and have lower levels of flicker (1/f) phase noise. When these MMIC VCOs are used with high-speed MMIC frequency dividers, it becomes possible to obtain the required combination of frequency agility and low phase noise.

  20. 植物声频控制技术对番茄生长性状、叶绿素及内源激素影响的研究%Effects of Plant Acoustic Frequency Technology on the Growth Traits, Chlorophyll Content and Endogenous Hormones of Lycopersicon esculentum

    Institute of Scientific and Technical Information of China (English)

    孟庆午; 周清; 郑劭婧; 高杨

    2012-01-01

    植物声频控制技术是利用作物与声波的协同关系,对作物发射一定波长和频率的声波,以促进作物生长及提高产量、质量的农业新技术.试验以番茄为试验材料,研究植物声频控制技术对番茄生长性状、叶绿素含量及内源激素生长素、赤霉素、玉米素核苷和脱落酸含量的影响.结果表明,植物声频控制技术能显著促进番茄的生长,可提高产量与叶片叶绿素的含量,还能刺激番茄内源激素生长素的分泌,并且刺激作用具有一定的时间积累效应.%Plant acoustic frequency technology was a new agricultural technology using certain wavelengths and frequencies of sound on the crops according to the sound and crops cooperative relations to increase the growth, yield and the quality of the crops. The effects of plant acoustic frequency control technology on Lycopersicon esculentum Mill, growth traits, chlorophyll content and endogenous plant hormones auxin, gibberellin, zeatin riboside and abscisic acid content were studied. The results showed that the plant acoustic frequency control technology could significantly promote the growth, yield and chlorophyll content of L. esculentum, stimulate the producing of endogenous hormone ghrelin secretion, which has time accumubation effect.

  1. Frequency-Locked Single-Frequency Fiber Laser at 2 Micron Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on our proprietary fiber technology and extensive experience in fiber laser development, a new single-frequency 2?]m fiber laser source will be developed. The...

  2. Difference-frequency combs in cold atom physics

    CERN Document Server

    Kliese, Russell; Puppe, Thomas; Rohde, Felix; Sell, Alexander; Zach, Armin; Leisching, Patrick; Kaenders, Wilhelm; Keegan, Niamh C; Bounds, Alistair D; Bridge, Elizabeth M; Leonard, Jack; Adams, Charles S; Cornish, Simon L; Jones, Matthew P A

    2016-01-01

    Optical frequency combs provide the clockwork to relate optical frequencies to radio frequencies. Hence, combs allow to measure optical frequencies with respect to a radio frequency where the accuracy is limited only by the reference signal. In order to provide a stable link between the radio and optical frequencies, the two parameters of the frequency comb must be fixed: the carrier envelope offset frequency $f_{\\rm ceo}$ and the pulse repetition-rate $f_{\\rm rep}$. We have developed the first optical frequency comb based on difference frequency generation (DFG) that eliminates $f_{\\rm ceo}$ by design - specifically tailored for applications in cold atom physics. An $f_{\\rm ceo}$-free spectrum at 1550 nm is generated from a super continuum spanning more than an optical octave. Established amplification and frequency conversion techniques based on reliable telecom fiber technology allow generation of multiple wavelength outputs. In this paper we discuss the frequency comb design, characterization, and optical...

  3. State Monitoring of High-Frequency Electric Resistance Welding Based on Digital Image Technology%基于数字图像技术的高频电阻焊状态监测

    Institute of Scientific and Technical Information of China (English)

    王会峰; 李云龙; 李记科

    2012-01-01

    为实现对高频电阻焊焊接过程的在线实时监测,通过对焊接现象、焊接缺陷及其成因的分析,提出了一种基于高速CCD成像和数字图像处理的焊接过程自动化监测方法.该方法利用架设在焊接区域上部的高速CCD相机获取焊接区的数字图像,通过对焊接区图像的特征加热面积、V型开口角大小、焊接熔合点位置、加热区对称度等多个参数的提取和测量,获取焊接区的多特征参数,然后将这些参数进行数据融合,得到当前的焊接状态.在图像处理中应用了基于非平衡R-G-B填充的抗干扰分割算法、基于直线拟合的V型角开口角大小及角分线检测算法,设计了面积对称度评价函数及基于BP神经网络的多特征融合模型.通过现场实验发现:文中方法能够有效监测焊接区的状态,有利于焊接质量控制.%In order to realize the real-time and on-line state monitoring of the high-frequency electric resistance welding (HF-ERW) , according to the analytical results of various welding phenomena as well as the welding defects and their causes, an automatic monitoring method based on the high-speed CCD imaging and the digital image processing is proposed. In this method, digital images of the welding region are obtained by using a CCD camera set on a fixed location above the welding region, and the parameters, such as the characteristic heating area, the value of V-type angle, the location of welding bond point and the symmetry degree of the heating region, are measured and processed through a multi-characteristic fusion, thus revealing the current welding state. Moreover, during the image processing, a new segmentation algorithm based on R-G-B non-equilibrium anti-inlerference technology is employed, the V-type angle detection and the corresponding bisection algorithm based on line fitting are adopted, a function to evaluate the symmetry degree of the heating region is designed, and a multi

  4. Multi-frequency excitation

    KAUST Repository

    Younis, Mohammad I.

    2016-03-10

    Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi- frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

  5. High-frequency ECG

    Science.gov (United States)

    Tragardh, Elin; Schlegel, Todd T.

    2006-01-01

    The standard ECG is by convention limited to 0.05-150 Hz, but higher frequencies are also present in the ECG signal. With high-resolution technology, it is possible to record and analyze these higher frequencies. The highest amplitudes of the high-frequency components are found within the QRS complex. In past years, the term "high frequency", "high fidelity", and "wideband electrocardiography" have been used by several investigators to refer to the process of recording ECGs with an extended bandwidth of up to 1000 Hz. Several investigators have tried to analyze HF-QRS with the hope that additional features seen in the QRS complex would provide information enhancing the diagnostic value of the ECG. The development of computerized ECG-recording devices that made it possible to record ECG signals with high resolution in both time and amplitude, as well as better possibilities to store and process the signals digitally, offered new methods for analysis. Different techniques to extract the HF-QRS have been described. Several bandwidths and filter types have been applied for the extraction as well as different signal-averaging techniques for noise reduction. There is no standard method for acquiring and quantifying HF-QRS. The physiological mechanisms underlying HF-QRS are still not fully understood. One theory is that HF-QRS are related to the conduction velocity and the fragmentation of the depolarization wave in the myocardium. In a three-dimensional model of the ventricles with a fractal conduction system it was shown that high numbers of splitting branches are associated with HF-QRS. In this experiment, it was also shown that the changes seen in HF-QRS in patients with myocardial ischemia might be due to the slowing of the conduction velocity in the region of ischemia. This mechanism has been tested by Watanabe et al by infusing sodium channel blockers into the left anterior descending artery in dogs. In their study, 60 unipolar ECGs were recorded from the entire

  6. Frequency selectivity at very low centre frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Marquardt, Torsten

    2010-01-01

    A significant factor in the decrease of sensitivity to low-frequency sound is the helicotrema shunt effect. In humans, it causes a slope increase of the middle-ear transfer function (METF) from 6 dB/oct to 12 dB/oct below approximately 50 Hz [Marquardt et al., J.Acoust. Soc. Am. 121, 3628......-3638 (2007)]. Recent experiments showed that the exact frequency varies from individual to individual. Besides, the helicotrema region in the METF has been found to highly influence frequency selectivity for centre frequencies (CFs) below 80 Hz (Jurado and Moore in prep). By using individual METF...... in the shape of the METFs, thought to be affected by the helicotrema impedance. Preliminary analysis indicates that individual differences in the METFs might underlay the observed individual differences in frequency selectivity. Main effects predicted by the calculations are a pronounced flattening off...

  7. Optical frequency standards for time and length applications

    Science.gov (United States)

    Hong, Feng-Lei

    2017-01-01

    The last decade has witnessed tremendous progress in research on optical frequency metrology. Optical frequency standards using optical lattice and single-ion trap technologies have reached levels of stability and accuracy that surpass the performance of the best Cs fountain atomic clocks by orders of magnitude. Optical frequency standards are also used for various applications including length metrology. Optical frequency measurement and links using optical frequency combs and optical fibres play important roles in the development of optical frequency standards. This article introduces optical frequency standards recommended by the International Committee for Weights and Measures (CIPM) along with updates provided by recent research results. Frequency ratio measurements and remote frequency comparisons are addressed in relation to the work whose goal is to redefine the second. Optical frequency standard and optical frequency comb applications are also described.

  8. The Opportunities and Challenges Brought about by RFID(Radio Frequency Identification Devices) Technology to ILAS(Integrated Library Automation System)%RFID技术带给ILAS的机遇与挑战

    Institute of Scientific and Technical Information of China (English)

    廖佳杰; 张丽; 王惠芳

    2015-01-01

    面对RFID技术带来的机遇与挑战,图书馆自动化集成系统(ILAS)开发商应主动实施基于RFID技术的应用开发,不能只是简单地应用RFID标签来取代条形码,而应在RFID技术基础上,创建全新的应用理念和业务模式,赋予ILAS智能化的内涵,充分利用RFID技术为图书馆信息化建设提供一个全新的手段。介绍了ILAS与RFID系统的应用现状,阐述了RFID技术带给ILAS的机遇与挑战。%Facing the opportunities and challenges brought about by the RFID technology, ILAS developers should actively implement the application development based on RFID technology, shouldn’t simply use RFID tags to replace the barcode, and should create a bran-new application concept and service mode based on RFID technology, give the intelligent connotation of ILAS, and provide a totally new method for library’s information construction by making full use of the RFID technology. This paper introduces the application status of ILAS and RFID system, and expounds the opportunities and challenges brought about by RFID technology to ILAS.

  9. Hyperfine phononic frequency comb

    CERN Document Server

    Ganesan, Adarsh; Seshia, Ashwin A

    2016-01-01

    Optical frequency combs [1-8] have resulted in significant advances in optical frequency metrology and found wide application to precise physical measurements [1-4, 9] and molecular fingerprinting [8]. A direct analogue of frequency combs in the phononic or acoustic domain has not been reported to date. In this letter, we report the first clear experimental evidence for a phononic frequency comb. In contrast to the Kerr nonlinearity [10] in optical frequency comb formation, the phononic frequency comb is generated through the intrinsic coupling of a driven phonon mode with an auto-parametrically excited sub-harmonic mode [16]. Through systematic experiments at different drive frequencies and amplitudes, we portray the well-connected process of phononic frequency comb formation and define attributes to control the features [17-18] associated with comb formation in such a system. Further, the interplay between these nonlinear resonances and the well-known Duffing phenomenon [12-14] is also observed. The present...

  10. Static electromagnetic frequency changers

    CERN Document Server

    Rozhanskii, L L

    1963-01-01

    Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work

  11. Modeling Frequency Comb Sources

    Directory of Open Access Journals (Sweden)

    Li Feng

    2016-06-01

    Full Text Available Frequency comb sources have revolutionized metrology and spectroscopy and found applications in many fields. Stable, low-cost, high-quality frequency comb sources are important to these applications. Modeling of the frequency comb sources will help the understanding of the operation mechanism and optimization of the design of such sources. In this paper,we review the theoretical models used and recent progress of the modeling of frequency comb sources.

  12. The Application of Library’s RFID(Radio Frequency Identification) Technology in the Practice%浅论图书馆RFID技术在实践中的应用

    Institute of Scientific and Technical Information of China (English)

    范红领

    2014-01-01

    阐述了图书馆RFID管理系统及其应用优势,探讨了图书馆RFID技术在实际应用中常见的问题及应对措施,提出了完善与发展图书馆RFID技术的策略。%This paper expounds library’s RFID management system and its application advantages, probes into some common problems existing in the actual application of library’s RFID technology, and puts forward some strategies for improving and developing library’s RFID technology.

  13. Eastern Frequency Response Study

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.

    2013-05-01

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  14. Radio-frequency integrated-circuit engineering

    CERN Document Server

    Nguyen, Cam

    2015-01-01

    Radio-Frequency Integrated-Circuit Engineering addresses the theory, analysis and design of passive and active RFIC's using Si-based CMOS and Bi-CMOS technologies, and other non-silicon based technologies. The materials covered are self-contained and presented in such detail that allows readers with only undergraduate electrical engineering knowledge in EM, RF, and circuits to understand and design RFICs. Organized into sixteen chapters, blending analog and microwave engineering, Radio-Frequency Integrated-Circuit Engineering emphasizes the microwave engineering approach for RFICs. Provide

  15. FPGA IMPLEMENTATION OF LOW POWER DIGITAL FREQUENCY

    Directory of Open Access Journals (Sweden)

    K. R. Rekha,

    2010-10-01

    Full Text Available In this Paper we are presenting a new FPGA approach to design an optimized use a Digital Frequency Synthesizer (DDFS in our system to generate a sampled sinusoidal wave of frequency. The major advantage of Digital Frequency Synthesizer (DFS is that its output frequency, phase and amplitude can be precisely and rapidly manipulated under the control of a DSP. Other inherent DFS attributes include the ability to tune with extremely fine frequency and phase resolution and to rapidly “hop” between the frequencies. These combined characteristics have made this technology popular in military, radar and communications systems. The digital circuits used to implementsignal processing functions do not suffer the effects of thermal drifts, aging and component variations associated with their analog counterparts. The implementation of digital functional blocks makes it possible to achieve a high degree of system integration. Recent advances in IC fabrication technology, particularly the CMOS technology coupled with advanced DSP algorithms and architectures provide possible single chip solutions to complex communication and signal processing sub-systems such as modulators, demodulators, local oscillators, and programmable clock generators, cellular base stations, up converters, down converters, power line communication,wireless local loop base stations etc .

  16. Frequency selective infrared sensors

    Science.gov (United States)

    Davids, Paul; Peters, David W

    2013-05-28

    A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.

  17. Status analysis of technology of mining medium-low-voltage frequency control equipment%矿用中低压变频调速设备技术的现状分析

    Institute of Scientific and Technical Information of China (English)

    李军; 申生太; 董淑棠; 顾潮青

    2016-01-01

    阐述了矿用设备运行中存在的问题,研究了当前各种矿用变频调速设备的工作原理、系统组成、功能及使用情况,探讨了矿用变频设备使用中应该关注的问题及采取的措施,针对不同矿用设备应该根据使用对象和工况特点进行选型配套,为用户全面了解矿用变频技术现状和选型配套提供了良好的技术支持。%The problems of mining equipment in the operation were elaborated,the operating principle,system composition,functions and service conditions of various kinds of mining fre-quency control equipment at present were studied,the issues of concern and the adopted meas-ures of mining frequency control equipment in use were discussed��Type selection and matching of different mining equipment should carry out according to using obj ects and operating condi-tions,which provided good technical supports for customers to overall understand the mining fre-quency control technical status and type selection and matching.

  18. Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, shows results......The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...

  19. 变频串联谐振技术在高压电缆交接试验中的应用%Application of Variable-Frequency Series Resonance Technology in Hand-over Acceptance Tests of High Voltage Power Cables

    Institute of Scientific and Technical Information of China (English)

    赵金明; 段肖华

    2012-01-01

    变频串联谐振耐压试验技术是当前高压试验的一种新方法.变频串联谐振的原理、组成及优点等进行了阐述,并对此技术在高压电缆交接试验中的应用进行了分析探讨,通过实例表明:此方法是科学、实用、高效的.%Variable-frequency series resonance withstand voltage technology is a new method widely in high voltage tests. This paper introduces the principle, composition and advantages of the technology, and discusses its applications in the acceptance tests of high voltage power cables. The actual examples show that the method is scientific and practical and efficient.

  20. High Reliability Technology of the Weld Zone of High-Frequency Electric Resistance Welding Linepipes%HFW管线钢管焊缝的高可靠性技术

    Institute of Scientific and Technical Information of China (English)

    孙宏; 王志太; 刘振伟

    2015-01-01

    为了解决HFW管线钢管焊缝可靠性问题, 通过使用高速摄像机实现了HFW焊接过程的动态可视化, 并构建了一个HFW数值分析模型, 从而优化HFW焊接条件并实现焊缝区域的均匀加热. 试验结果表明, 焊接条件优化后开发出的HFW钢管焊缝金属的夏比韧脆转变温度达到-90 ℃,且具有较高的低温吸收能量值. 此外, 开发的点融合串列束超声波检验方法实现了焊缝区氧化物的实时连续检测, 其灵敏度为常规方法的10倍以上.%To address the significant need for weld seam reliability,the HFW phenomena were visualized dynamically using a high-speed video camera,and an HFW numerical analysis model was constructed to develop optimization technology of HFW conditions and the homogeneous heating technology of the weld zone. The Charpy fracture transition temperature of the weld metal of the developed steel pipe was -90℃ showing the high absorbed energy value at cryogenic temperature. Furthermore, real-time continuous detection technology of the oxide of the weld zone was developed by a point converging tandem beam ultrasonic inspection method. This technology achieved high sensitivity 10 times or more than that of the conventional method.

  1. 基于FPGA的卫星数字频率信号处理关键技术研究与实现%Research and implementation of key technologies about satellite digital frequency signal processing based on FPGA

    Institute of Scientific and Technical Information of China (English)

    罗来金; 曾连荪

    2011-01-01

    This paper introduced how to use ALTERA Cyclone II series FPGA EP2C70F896C6N with equal precision frequency measurement method and corresponding digital signal processing IP core,and then completed design of the measurements and processing system about three directions angular velocity and temperature signals of a certain type satellite's Gyro X,Y,Z axis.Experimental results show that the FPGA-based digital frequency signal processing system has a high accuracy,high integration,high-speed and high reliability features compared with the previous digital frequency signal processing circuit,meets the signal processing circuit design for high standards in space systems.%采用等精度测频法及相应的数字信号处理IP核,以ALTERA公司Cyclone II系列EP2C70F896C6N FPGA为核心实现了某型卫星陀螺组合X、Y、Z轴3个方向上的角速度信号、温度信号的测量处理系统的设计。实验结果表明基于FPGA的数字频率信号处理系统相对于以往数字频率信号处理电路具有高精度、高集成度、高速和高可靠性的特点,满足航天系统对信号处理电路设计高标准的要求。

  2. Research on frequency tracking technology of electronic ballasts for electrodeless lamp%无极灯电子镇流器频率跟踪控制技术研究

    Institute of Scientific and Technical Information of China (English)

    沈豫; 林国庆; 唐建山

    2013-01-01

    Due to the excellent features of high efficiency, high color rendering, no flash and long life, electrode-less lamp becomes a new gas-discharge light source with a good development prospect. Electrodeless lamp has a negative resistance property, so that a reliable electronic ballast assorted is needed for the lamp. Based on the analysis of the electrical model of electrodeless lamp, a novel control strategy suitable for load characteristics of electrodeless lamp is presented in the paper. The resonant frequency is searched to get the trigger high voltage by frequency sweeping. In order to achieve the maximum output power and best load matching, the phase difference between inverter output voltage and resonant capacitor voltage is adopted as the phase loop control variable to track resonant frequency automatically in normal operation. Finally, the simulation and experiment results have proved the feasibility of the proposed strategy.%基于无极灯电气模型的分析,提出一种适合于无极灯负载特性的控制策略.通过扫频控制寻找谐振频率以产生点灯所需的高压脉冲,正常运行时以半桥逆变器中点电压与谐振电容电压的相位差作为闭环控制变量实现对谐振频率的自动跟踪控制,以获得最大的功率输出和最佳的负载匹配.电路仿真和实验结果验证了所提出的方案是可行的.

  3. Research on High-Frequency Modulated Signal Demodulation Technology in Laser Heterodyne Detection%激光外差探测中高频调制信号解调技术的研究

    Institute of Scientific and Technical Information of China (English)

    杨玮萍; 郑宾; 张志刚; 郭华玲; 陈栋; 王余敬

    2016-01-01

    激光外差干涉信号属于宽带高频信号,针对这一特点,提出了一种新型的激光外差干涉信号的高频调制信号解调系统。在AD8302相位解调方法的基础上,锁相环的设计可以消除解调结果中的差频信号。结果表明,相比于MATLAB软件解调和AD8302直接解调,该解调系统可以更准确地解调出样品表面1 MHz的微振动信号。因此,本系统是一种有效可行的相位解调方法。%The laser heterodyne interference signals belong to the wideband and high-frequency signals. According to this characteristic,a new kind of high-frequency modulated signals demodulation system for laser heterodyne in⁃terference signals is proposed. Based on the method of phase demodulation with AD8302,the design of phase locked loop can eliminate the differential frequency signals in the demodulation results. The results show that this demodulation system can demodulate 1 MHz micro-vibration signal on the surface of the sample accurately,com⁃pared with the MATLAB software demodulation and AD8302 direct demodulation. Therefore,this system is an effec⁃tive and feasible method for phase demodulation.

  4. An Automatic Meter Reading System Based on Integrated Carrier and Power Frequency Technology%基于载波和工频混合组网技术的集中抄表系统

    Institute of Scientific and Technical Information of China (English)

    王智慧; 李建歧; 渠晓峰; 赵涛

    2011-01-01

    低压电力线载波信道的衰减、干扰以及随机时变性使得载波通信方式无法满足集中抄表系统全采集、全覆盖的建设要求.工频通信也是通过电力线传输信号,并使用50Hz工频信号作为载波,与3~500kHz的载波通信频率范围互不冲突.本文利用工频通信传输距离远、可靠性高、成本低廉的特点,在不增加额外设备的条件下,实现了载波与工频两种通信方式的混合组网.针对所给出的组网方案,详细论述了集中器和采集器的系统实现.现场测试表明,该系统抄收成功率高、通信效果好,有效解决了载波通信盲点问题.%Low- voltage power line carrier channel attenuation, interference and random dynamicity make the carrier communication can not satisfy automatic meter reading system whole collection and coverage construction requirements.TWACS also transmits signal by power line, and uses the 50Hz power frequency signal as its carrier frequency, which is not conflictive with the 3 ~ 500kHz carrier communication frequency range. Based on the long transmission distance,high communication reliability and low cost of TWACS, this paper realizes a mixing network composed of carrier and power frequency communication without any additional equipment. Then the system implementation of concentrator and acquisition terminal is discussed, aiming at the given networking scheme. The field test proved that the system effectively solves the carrier communication blind spot problem, with high reading success rate and good communication effect.

  5. Radio frequency detection assembly and method for detecting radio frequencies

    Science.gov (United States)

    Cown, Steven H.; Derr, Kurt Warren

    2010-03-16

    A radio frequency detection assembly is described and which includes a radio frequency detector which detects a radio frequency emission produced by a radio frequency emitter from a given location which is remote relative to the radio frequency detector; a location assembly electrically coupled with the radio frequency detector and which is operable to estimate the location of the radio frequency emitter from the radio frequency emission which has been received; and a radio frequency transmitter electrically coupled with the radio frequency detector and the location assembly, and which transmits a radio frequency signal which reports the presence of the radio frequency emitter.

  6. Universal Optical Frequency Comb

    CERN Document Server

    Savchenkov, A A; Liang, W; Ilchenko, V S; Seidel, D; Maleki, L

    2010-01-01

    We demonstrate that whispering gallery mode resonators can be utilized to generate optical frequency combs based on four wave mixing process at virtually any frequency that lies in the transparency window of the resonator host material. We show theoretically how the morphology of the resonator can be engineered to produce a family of spectrally equidistant modes with anomalous group velocity dispersion appropriate for the comb generation. We present experimental results for a frequency comb centered at 794 nm to support our theoretical findings.

  7. Probability and Relative Frequency

    Science.gov (United States)

    Drieschner, Michael

    2016-01-01

    The concept of probability seems to have been inexplicable since its invention in the seventeenth century. In its use in science, probability is closely related with relative frequency. So the task seems to be interpreting that relation. In this paper, we start with predicted relative frequency and show that its structure is the same as that of probability. I propose to call that the `prediction interpretation' of probability. The consequences of that definition are discussed. The "ladder"-structure of the probability calculus is analyzed. The expectation of the relative frequency is shown to be equal to the predicted relative frequency. Probability is shown to be the most general empirically testable prediction.

  8. Frequency Response Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Etingov, Pavel V.; Kosterev, Dmitry; Dai, T.

    2014-12-31

    Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

  9. Frequency Response Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Etingov, Pavel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kosterev, Dmitry [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dai, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

  10. Optimization of frequency quantization

    CERN Document Server

    Tibabishev, V N

    2011-01-01

    We obtain the functional defining the price and quality of sample readings of the generalized velocities. It is shown that the optimal sampling frequency, in the sense of minimizing the functional quality and price depends on the sampling of the upper cutoff frequency of the analog signal of the order of the generalized velocities measured by the generalized coordinates, the frequency properties of the analog input filter and a maximum sampling rate for analog-digital converter (ADC). An example of calculating the frequency quantization for two-tier ADC with an input RC filter.

  11. Low Phase Noise Design Technology of Frequency Synthesizer at 1 Hz for Deep Space TT & C System%深空测控系统1 Hz低相噪频率合成技术

    Institute of Scientific and Technical Information of China (English)

    杜丹

    2015-01-01

    针对深空测控系统高精度测量对于信道附加相噪的要求,采用直接数字频率合成( DDS )正交调制方法设计频率综合器。通过巧妙的试验和外推方法,择优选取电压型鉴相器,在锁相环相噪模型的基础上,全面分析各部分相噪的贡献,综合设计环路带宽,有效控制附加相噪,实现低相噪频综器最理想的目标,即环路带内的相噪完全由参考决定,带外的相噪由压控振荡器( VCO)决定,并采用两源互比的方法完成1 Hz极低相位噪声的测试,测试结果为-73 dBc/Hz,与设计结果完全一致。该方法对于测控站极低相噪的设计具有一定参考价值。%For the additional phase noise requirements on channels in deep space TT&C system with high ac-curacy measurement,a frequency synthesizer is designed using direct digital synthesizing(DDS) quadrature modulation. A voltage-type phase discriminator is selected by smart test and extrapolation method. Based on phase noise model of phase locked loop,contributions from all parts of phase noise are analyzed. So the idea-lest performance of frequency synthesizer with low phase noise,i. e. loop in-band phase noise is depended on reference frequency,and out-band phase noise is determined by voltage-controlled oscillator(VCO),is implemented by loop bandwidth integrated design and efficient additional phase noise control. The 1 Hz low phase noise is tested through comparing two sources and it is-73 dBc/Hz,which is consistent with design re-sult. This method is valuable to low phase noise design in deep space TT&C ground station.

  12. SMART TRAVELLING WITH RADIO FREQUENCY IDENTIFICATION

    Directory of Open Access Journals (Sweden)

    Zainab Rasheed Fahad Mirza

    2013-01-01

    Full Text Available Radio Frequency Identification (RFID technology is being widely used now-a-days and is becoming more popular with every passing day. There are varied applications of this technology in various fields such as industry, communication, travel and transportation. Roads, rail ways, air traffic and container vessel shipping all share underlying abstractions of transportation nets with hubs. This study is concerned with applications of RFID technology with Cloud computing, innovation in the field of travelling and its applications for different modes of transportation at Harbors, airports, train stations, road intersections providing security, coordination, to the users. Combined with other technologies, RFID technology is being used for modern airports baggage system, for railroad car identification, in container transportation systems, for fuel supply control of vehicles, in traffic management system and in travelling information system.

  13. Fast Hopping Frequency Generation in Digital CMOS

    CERN Document Server

    Farazian, Mohammad; Gudem, Prasad S

    2013-01-01

    Overcoming the agility limitations of conventional frequency synthesizers in multi-band OFDM ultra wideband is a key research goal in digital technology. This volume outlines a frequency plan that can generate all the required frequencies from a single fixed frequency, able to implement center frequencies with no more than two levels of SSB mixing. It recognizes the need for future synthesizers to bypass on-chip inductors and operate at low voltages to enable the increased integration and efficiency of networked appliances. The author examines in depth the architecture of the dividers that generate the necessary frequencies from a single base frequency and are capable of establishing a fractional division ratio.   Presenting the first CMOS inductorless single PLL 14-band frequency synthesizer for MB-OFDMUWB makes this volume a key addition to the literature, and with the synthesizer capable of arbitrary band-hopping in less than two nanoseconds, it operates well within the desired range on a 1.2-volt power s...

  14. 77 FR 8222 - Notice Requesting Nominations for the Subcommittee on Automated and High Frequency Trading

    Science.gov (United States)

    2012-02-14

    ... COMMISSION Notice Requesting Nominations for the Subcommittee on Automated and High Frequency Trading AGENCY... Automated and High Frequency Trading within the Technology Advisory Committee. SUMMARY: The Commodity... Automated and High Frequency Trading (Subcommittee) under the auspices of the Technology Advisory Committee...

  15. Medium Frequency Electrotherapy Product Registration Inspection Technology Index and its Detection Method%中频电疗产品注册检验技术指标及其检测方法

    Institute of Scientific and Technical Information of China (English)

    王澜; 邢立镛; 苏宁; 谢胜芬

    2016-01-01

    According to the new technical indicators in the State Food and Drug Administration “electrotherapy product registration technical review guidelines”. this paper analyzes and interpretes the new inspection method combined with\\ the existing ones. Some thoughts and discussions are suggested in order to improve the quality of mid-frequency electrotherapy product.%本文就国家食品药品监督管理总局修订的《中频电疗产品注册技术审查指导原则》新增的技术指标进行分析解读,并结合我单位的检测情况对其检测方法进行探讨,提出一些思考和建议,以期对提高中频电疗产品的产品质量有所帮助。

  16. Low Noise Amplifier for 2.45 GHz Frequency Band at 0.18 μm CMOS Technology for IEEE Standard 802.11 b/g WLAN

    Directory of Open Access Journals (Sweden)

    Viranjay M. Srivastava

    2012-08-01

    Full Text Available This paper presents the design of low noise amplifier (LNA at 2.45 GHz and integrated at 0.18 µm RF CMOS process technology. This type of LNA at 2.45 GHz is use in the Bluetooth receiver. The proposed method is useful to optimize noise performance and power gain while maintaining good input and output matching. The amplifier is designed to be used as first stage of a receiver for wireless communication. The main aim of designer is to achieve low noise figure with improved gain with the help of CMOS technology by using single stage n-MOS amplifier. The simulation results show a forward gain of 14.0 dB, a noise-figure of 0.5 dB and stability factor is approximate unity, in which the circuit operates at 14.2 mA drain current with supply voltage of 3.5 V and biasing voltage of 1.5 V.

  17. Application of Wireless Radio Frequency Collecting Technology in Electric Power Meter Collection%无线射频集抄技术在电力抄表中的应用

    Institute of Scientific and Technical Information of China (English)

    王春霞; 吴慧

    2012-01-01

    In this paper,based on the GPRS(General Packet Radio Service) mobile communications network,the meter data wireless collecting system is designed,the GPRS data transparent transmission module is developed and the meter data wireless transmission network is realized.With the help of the wireless IP technology and VPN(Virtual Private Network) technology,the remote wireless meter reading for industrial and civilian users is carried out efficiently and at low cost.%文中基于GPRS(General Packet Radio Service,通用无线分组业务)移动通信网络,设计了电表数据的无线集抄系统,开发了GPRS数据透明传输模块,实现了电表数据的无线传输网络。它借助于无线IP技术、虚拟数据专用网VPN(Virtual Private Network)技术,能高效、低成本进行工业或民用电表数据的远程无线集抄。

  18. 多频多段人体生物电阻抗测量系统%A Bioelectrical Impedance Measurement System Based on Multi-Frequency and Multi-Segment Technology

    Institute of Scientific and Technical Information of China (English)

    高秀娥; 唐佳; 陈波

    2012-01-01

    Bioelectrical impedance is an important composition of human body, and reflects the physical conditions of human tissues to some extent. Based on this, a multi-frequency and multi-segment bioelectrical impedance measurement system is designed on the principle of eight electrodes. In fact, the system, which consists of MCU system, sinusoidal excitation current source, RMS-to-DC circuit and etc, has achieved the impedance measurement of the extremities as well as the trunk under the frequency ranged from 5 ~ 500 kHz. Experiment results show that the system finally realizes high-accuracy measurements of amplitude and phase of bioelectrical impedance with the result of a relative error of magnitude which is less than 0. 7% and an absolute error of phase which is less than 0.8°.%人体生物电阻抗是人体体成分的重要组成部分,在一定程度上反映了人体组织的生理状况.基于此,设计了一套基于八电极的多频多段人体生物电阻抗测量系统.测量系统由单片机系统、正弦交流激励电流源、有效值检测电路等组成,实现了5 ~ 500 kHz频率范围的左右上下肢及躯干的5段测量.测试结果表明,测量系统实现了人体生物电阻抗的幅值和相位的高精度测量,幅值相对误差小于0.7%,相位绝对误差小于0.8°.

  19. FET frequency discriminator

    Science.gov (United States)

    Mawhinney, F. D.

    1982-03-01

    The FET Frequency Discriminator is an experimental microwave frequency discriminator developed for use in a specialized set-on VCO frequency memory system. Additional development and evaluation work has been done during this program to more fully determine the applicability of the FET frequency discriminator as a low-cost, expendable receiver front-end for both surveillance and ECM systems. Various methods for adjusting the frequency-to-voltage characteristic of the discriminator as well as the effects of detector characteristics and ambient temperature changes were evaluated. A number of discriminators for use in the 7- to 11-GHz and the 11to 18-GHz bands were fabricated and tested. Interim breadboard and final packaged models were either delivered or installed in developmental frequency systems. The major limitations and deficiencies of the FET frequency discriminator that were reviewed during the program include the effects of temperature, input power level variations, nonlinearity, and component repeatability. Additional effort will be required to advance the developmental status of the FET frequency discriminator to the level necessary for inclusion in low-cost receiver systems, but the basic simplicity of the approach continues to show much promise.

  20. Microfabricated ion frequency standard

    Science.gov (United States)

    Schwindt, Peter; Biedermann, Grant; Blain, Matthew G.; Stick, Daniel L.; Serkland, Darwin K.; Olsson, III, Roy H.

    2010-12-28

    A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

  1. Breakfast frequency among adolescents

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Damsgaard, Mogens Trab

    2016-01-01

    , quality of family communication and family support. Further, analyses suggested that the associations were more pronounced among girls, immigrants and adolescents from other family structure than traditional. The study highlights the importance of the family setting in promoting regular breakfast......OBJECTIVE: To investigate (i) associations between adolescents' frequency of breakfast and family functioning (close relations to parents, quality of family communication and family support) and (ii) if any observed associations between breakfast frequency and family functioning vary...... (n 3054) from a random sample of forty-one schools. RESULTS: Nearly one-quarter of the adolescents had low breakfast frequency. Low breakfast frequency was associated with low family functioning measured by three dimensions. The OR (95 % CI) of low breakfast frequency was 1·81 (1·40, 2...

  2. Application of radio frequency identification technology in the logistics management of modern medical supplies%射频识别技术在医用耗材物流管理中的应用

    Institute of Scientific and Technical Information of China (English)

    邹冬梅; 蔡颖尔; 黄燕尔

    2015-01-01

    目的:探讨医用耗材管理的现状及射频识别(RFID)技术在医用耗材管理中的应用。方法:总结医用耗材实行零库存管理经验,为医用耗材管理提供方向和依据,并对医用耗材实施规范、系统及全面的管理。结果:医用物品物流管理的应用,对于降低医疗成本、提高医用耗材管理水平、加快资金的周转对医院可持续发展均具有重要意义。结论:医用耗材在医疗卫生实践中的地位及发挥的作用是无可替代,而RFID技术作为一项先进的自动识别和数据采集技术,在未来医疗领域中将是医院医用物品物流管理不可缺少的组成部分。%Objective:To understand the status of medical supplies management and explore the application of RFID technology in medical supplies management.Methods: The implementation of inventory management summarizes some of the experiences from medical supplies, medical supplies in the future direction and management to provide some basis for the implementation of standardized medical supplies, systematic and comprehensive management.Results: Reduce health care costs and improve the level of medical supplies management and accelerate the flow of funds has important significance for the sustainable development of the hospital.Conclusion:The role played by medical supplies and health care practice in the status is irreplaceable, RFID technology as an advanced automatic identification and data capture technologies in the medical field in the future become a hospital for medical goods logistics management indispensable component.

  3. Dielectric heating. Technologies; Chauffage dielectrique. Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Roussy, G. [Universite Henri-Poincare, Dir. de Recherche, 54 - Nancy (France); Rochas, J.F. [Societe Sairem, 69 - Lyon (France); Oberlin, C. [Electricite de France (EDF), 75 - Paris (France)

    2003-08-01

    The electrothermal heating processes are of two types: the indirect heating (indirect resistance, infrared, indirect arc and plasma heating) in which the energy transfer from the source to the receptor complies with the usual thermal laws, and the direct heating (direct ohmic, induction, high-frequency, microwave, electron bombardment, laser and direct arc heating) in which the receptor is crossed by an electric current which generates a heat release inside the receptor. This paper treats of the technologies used in high frequency and microwave heating: 1 - techniques of implementation of high-frequency (HF) heating: HF generator, energy transmission line, HF applicator, impedance adjustment system, auxiliary devices; 2 - techniques of implementation of microwave heating: microwave generator, wave guide, microwave applicator, impedance adjustment circuit, auxiliary devices. (J.S.)

  4. Detecting deception via eyeblink frequency modulation

    Directory of Open Access Journals (Sweden)

    Brandon S. Perelman

    2014-02-01

    Full Text Available To assess the efficacy of using eyeblink frequency modulation to detect deception about a third party, 32 participants were sent on a mission to deliver a package to an interviewer. 17 of the participants lied to the interviewer about the details of their mock mission and 15 responded truthfully. During the interview, eyeblink frequency data were collected via electromyography and recorded video. Liars displayed eyeblink frequency suppression while lying, while truth tellers exhibited an increase in eyeblink frequency during the mission relevant questioning period. The compensatory flurry of eyeblinks following deception observed in previous studies was absent in the present study. A discriminant function using eyeblink suppression to predict lying correctly classified 81.3% of cases, with a sensitivity of 88.2% and a specificity of 73.3%. This technique, yielding a reasonable sensitivity, shows promise for future testing as, unlike polygraph, it is compatible with distance technology.

  5. High-frequency micromechanical columnar resonators

    Directory of Open Access Journals (Sweden)

    Jenny Kehrbusch, Elena A Ilin, Peter Bozek, Bernhard Radzio and Egbert Oesterschulze

    2009-01-01

    Full Text Available High-frequency silicon columnar microresonators are fabricated using a simple but effective technological scheme. An optimized fabrication scheme was invented to obtain mechanically protected microcolumns with lateral dimensions controlled on a scale of at least 1 μm. In this paper, we investigate the influence of the environmental conditions on the mechanical resonator properties. At ambient conditions, we observed a frequency stability δf/f of less than 10−6 during 5 h of operation at almost constant temperature. However, varying the temperature shifts the frequency by approximately −173 Hz °C− 1. In accordance with a viscous damping model of the ambient gas, we perceived that the quality factor of the first flexural mode decreased with the inverse of the square root of pressure. However, in the low-pressure regime, a linear dependence was observed. We also investigated the influence of the type of the immersing gas on the resonant frequency.

  6. Frequency comb generation in quadratic nonlinear media

    CERN Document Server

    Ricciardi, Iolanda; Parisi, Maria; Maddaloni, Pasquale; Santamaria, Luigi; De Natale, Paolo; De Rosa, Maurizio

    2014-01-01

    Optical frequency combs are nowadays routinely used tools in a wide range of scientific and technological applications. Different techniques have been developed for generating optical frequency combs, like mode-locking in lasers and third-order interactions in microresonators, or to extend their spectral capabilities, using frequency conversion processes in nonlinear materials. Here, we experimentally demonstrate and theoretically explain the onset of optical frequency combs in a simple cavity-enhanced second-harmonic-generation system, exploiting second-order nonlinear interactions. We develop an elemental model which provides a deep physical insight into the observed dynamics. Moreover, despite the different underlying physical mechanism, the proposed model is remarkably similar to the description of third-order effects in microresonators, revealing a potential variety of new effects to be explored. Finally, exploiting a nonlinearity intrinsically stronger than the third-order one, our work lays the groundw...

  7. 光纤光栅外腔半导体激光器频率调谐技术研究%Study on frequency tuning technology of fiber Bragg grating external cavity semiconductor laser

    Institute of Scientific and Technical Information of China (English)

    高源

    2016-01-01

    Based on the analysis of the basic characteristics of fiber Bragg grating external cavity semiconductor laser (FBG -ECL),the frequency tuning methods for this type of lasers are investigated,including temperature tuning method and stress tuning method.The center wavelength of fiber Bragg grating is changed by the axial stress tuning method to realize the frequency tuning.The piezoelectric ceramic(PZT)was used to exert an axial stress on the grat-ing,and the amount of change in the center wavelength of the fiber Bragg grating was controlled by adjusting PZT drive voltage.The experimental results show that,for the FBG -ECL with wavelength 1550 nm,when the PZT drive voltage adds up to 126 V,tuning range can reach 100 GHz and tuning speed can reach 2 ms per cycle.%在分析了光纤光栅外腔半导体激光器(FBG -ECL)基本特性的基础上,调研了适用于该类型激光器的频率调谐方法,包括温度调谐法和应力调谐法,选取轴向应力调谐法改变光纤光栅的布拉格中心波长,进而实现频率调谐。利用压电陶瓷(PZT)来对光纤光栅施加轴向应力,通过调整 PZT 驱动电压值的大小来控制光纤光栅布拉格中心波长的变化量。实验结果表明,对于波长1550 nm 的光纤光栅激光器,当 PZT 的驱动电压增加到126 V 时,可实现0.8 nm,即100 GHz 的调谐范围以及每周期2 ms 的调谐速度。

  8. Frequency comb swept lasers.

    Science.gov (United States)

    Tsai, Tsung-Han; Zhou, Chao; Adler, Desmond C; Fujimoto, James G

    2009-11-09

    We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep rate of 1kHz and 120kHz, respectively over a 135nm tuning range centered at 1310nm with average output powers of 50mW. A 25GHz free spectral range frequency comb filter in the swept lasers causes the lasers to generate a series of well defined frequency steps. The narrow bandwidth (0.015nm) of the frequency comb filter enables a approximately -1.2dB sensitivity roll off over approximately 3mm range, compared to conventional swept source and FDML lasers which have -10dB and -5dB roll offs, respectively. Measurements at very long ranges are possible with minimal sensitivity loss, however reflections from outside the principal measurement range of 0-3mm appear aliased back into the principal range. In addition, the frequency comb output from the lasers are equally spaced in frequency (linear in k-space). The filtered laser output can be used to self-clock the OCT interference signal sampling, enabling direct fast Fourier transformation of the fringe signals, without the need for fringe recalibration procedures. The design and operation principles of FC swept lasers are discussed and designs for short cavity lasers for OCT and interferometric measurement applications are proposed.

  9. High Temperature, High Frequency Fuel Metering Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Active Signal Technologies and its subcontractor Moog propose to develop a high-frequency actuator driven valve intended to achieve TRL 6 by the end of Phase II....

  10. Frequency standards from government laboratories over the next 25 years

    Science.gov (United States)

    Maleki, L.

    1994-01-01

    Based on a number of considerations including projected needs, current status, future trends, and status of key technologies, an attempt is made to project the future of government supported frequency standards development in the next 25 years.

  11. Research and Design of Voice Controlled Automobile Skylight based on the Frequency Cepstrum Coefficients Technology%基于 MEL 频率倒谱系数技术的音控汽车天窗的研究设计

    Institute of Scientific and Technical Information of China (English)

    袁霞; 赵向阳

    2015-01-01

    基于对语音信号的研究,采用M EL频率倒谱系数对语音信号进行提取,动态规划的思想进行语音信号的匹配,以汽车天窗为控制对象,实现了系统样机的研制。测试结果表明,系统在车内噪音低于70分贝下的平均识别率高达93%。%This paper realized the development of the system prototype , based on the study of speech signal ,the extraction of speech by Mel Frequency Cepstrum Coefficient ,matching the speech signal through the idea of dynamic programming ,automobile skylight as the control object .The test re‐sults showed that the average recognition rate of the system is high to 93.6% when the vehicle interior noise less than 70 decibels .

  12. Design of wireless smart sensing tag based on radio frequency technology%基于射频技术的无线智能传感标签设计

    Institute of Scientific and Technical Information of China (English)

    张世辉; 李松; 陈硕; 翁雪涛

    2015-01-01

    针对目前普通电子标签和现有传感标签功能的局限性,设计了一种集射频识别、传感信息采集、物流仓储信息显示于一体的特高频( UHF)智能传感标签。该标签采用ATmega 328P为控制核心,温湿度传感器SHT10、运动传感器MPU6050为感知器件,LED作为信息显示器件,UHF无源标签芯片UCODE I2 C作为射频信号的收发器,在减少功耗的同时,实现了环境监测、姿态监控和物流操作信息提示。%A novel ultra high frequency( UHF ) smart sensing tag integrates RFID chip,sensing information acquisition and logistics warehouse information displaying is designed. Temperature and humidity sensor SHT10 and MPU6050 motion sensor are used as sensing device,LED as information display device,UHF passive tag chip UCODE I2 C are used as transceiver of RF signal,it reduces power consumption and realize environment and posture monitoring and logistics operating information display.

  13. The Low Carbon Technology for Frequency Constant Pressure Water Supply Control and Application%恒压供水变频控制低碳技术及应用

    Institute of Scientific and Technical Information of China (English)

    卢祥江; 武宇龙

    2014-01-01

    In view of the problems of instability, excessive energy consumption and long time lag of current variable frequency constant pressure water supply, the model free control method was applied to the constant pressure water supply system, and on the basis of research of water supply characteristics, the specific water supply equipment was analyzed and improved. The practice showed that the improved water supply system realized stable pressure water supply, obvious effect of energy-saving, fast response speed and long-term stable and reliable operation.%针对当前变频恒压供水压力不稳定、能耗过大、滞后时间过长等问题,将无模型控制方式运用到恒压变频供水系统中,同时在分析供水特性的基础上,对具体的供水设备进行分析和改进。实践表明,改进之后的供水系统实现了供水压力稳定,节能效果明显,反应执行速度快捷,长期运行稳定可靠。

  14. Broadband frequency conversion

    DEFF Research Database (Denmark)

    Sanders, Nicolai Højer; Jensen, Ole Bjarlin; Dam, Jeppe Seidelin;

    that ensures phase matching over a broad spectral range in the BBO crystal. Since the tuning mechanism relies on all-passive components with extremely short response times the proposed method is well suited for short pulse, broad bandwidth laser sources like mode-locked lasers or super-continuum sources......We demonstrate a method for frequency conversion of broadly tunable or broad bandwidth light in a static, passive setup. Using simple optical components like lenses, mirrors and gratings and a BiBO crystal as the nonlinear material, we are able to frequency double a single-frequency, tunable...

  15. Pragmatic circuits frequency domain

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Frequency Domain goes through the Laplace transform to get from the time domain to topics that include the s-plane, Bode diagrams, and the sinusoidal steady state. This second of three volumes ends with a-c power, which, although it is just a special case of the sinusoidal steady state, is an important topic with unique techniques and terminology. Pragmatic Circuits: Frequency Domain is focused on the frequency domain. In other words, time will no longer be the independent variable in our analysis. The two other volumes in the Pragmatic Circuits series include titles on DC

  16. From frequency to time-average-frequency a paradigm shift in the design of electronic system

    CERN Document Server

    Xiu, Liming

    2015-01-01

    Written in a simple, easy to understand style, this book will teach PLL users how to use new clock technology in their work in order to create innovative applications.       Investigates the clock frequency concept from a different perspective--at an application level       Teaches engineers to use this new clocking technology to create innovations in chip/system level, through real examples extracted from commercial products  

  17. CHP Technologies

    Science.gov (United States)

    Learn about CHP technologies, including reciprocating engines, combustion turbines, steam turbines, microturbines, fuel cells, and waste heat to power. Access the Catalog of CHP Technologies and the Biomass CHP Catalog of Technologies.

  18. Assistive Technology

    Science.gov (United States)

    ... Page Resize Text Printer Friendly Online Chat Assistive Technology Assistive technology (AT) is any service or tool that helps ... be difficult or impossible. For older adults, such technology may be a walker to improve mobility or ...

  19. Microwave Radiometer - high frequency

    Data.gov (United States)

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

  20. Multi-frequency axial transmission bone ultrasonometer.

    Science.gov (United States)

    Tatarinov, Alexey; Egorov, Vladimir; Sarvazyan, Noune; Sarvazyan, Armen

    2014-07-01

    The last decade has seen a surge in the development of axial transmission QUS (Quantitative UltraSound) technologies for the assessment of long bones using various modes of acoustic waves. The condition of cortical bones and the development of osteoporosis are determined by numerous mechanical, micro-structural, and geometrical or macro-structural bone properties like hardness, porosity and cortical thickness. Such complex manifestations of osteoporosis require the evaluation of multiple parameters with different sensitivities to the various properties of bone that are affected by the disease. This objective may be achieved by using a multi-frequency ultrasonic examination The ratio of the acoustic wavelength to the cortical thickness can be changed by varying the frequency of the ultrasonic pulse propagating through the long bone that results in the change in composition of the induced wave comprised of a set of numerous modes of guided, longitudinal, and surface acoustic waves. The multi-frequency axial transmission QUS method developed at Artann Laboratories (Trenton, NJ) is implemented in the Bone Ultrasonic Scanner (BUSS). In the current version of the BUSS, a train of ultrasonic pulses with 60, 100, 400, 800, and 1200 kHz frequencies is used. The developed technology was tested on a variety of bone phantoms simulating normal, osteopenic, and osteoporotic bones. The results of this study confirm the feasibility of the multi-frequency approach for the assessment of the processes leading to osteoporosis.

  1. 基于变频和PLC技术的自动剪板机控制系统%Control System for Automatic Plate Shearing Machine Based on Technology of Frequency Conversion and PLC

    Institute of Scientific and Technical Information of China (English)

    李增权

    2016-01-01

    为克服普通剪板机加工精度不高,人工操作繁琐、容易出错,能耗大,效率低的不足,提出了剪板机升级为自动控制的实现方案:以PLC可编程控制系统为核心,实现多台电机的同步协调运转;再经过变频调速器控制喂料电机,实现频繁的启动、制动及精确定长。在喂料电机及自动定长单元设计中,提出了Pang-Pang控制与谨慎控制相结合的设计思路,兼顾了生产效率和定长精度两者的需求。经实验室模拟调试,系统的控制功能及控制精度达到了设计要求。该剪板机具有自动化程度高、定长精确、能耗低、喂料电机能适应频繁的启动、制动等优点,提高了生产效率和板材的剪切质量。%To overcome the deficiencies of current plate shearing machine, which are the bad machining precision, complex artificial operation, easy errors, energy-wasting and inefficient, this paper puts forward such a realization scheme for the plate shearing machine to update it to automatic controlling, which is to take PLC programmable control system as its core to realize the synchronous operation coordinately with multi electric machinery. Then, frequent starting, braking and accurate fixing length will be realized through the controlling of the feeding motor by frequency converter. In the modular design of the feeding motor and automatic fixing length, put forward a design idea of integrating Pang-Pang control with conservative control to take both the productivity and accurate length-fixing into consideration. After analogue debugging in laboratory, both the control function and the control precision of the system meet design requirements. Such plate shearing machine enhances production efficiency and cutting quality of the plates with its advantages of high automation, accurate length fixing, lower energy-wasting, and also the frequent starting and braking of the feeding motor.

  2. Intelligent Management of Power Supply Based on Radio Frequency Identiifcation Technology%基于射频识别技术的电源权限智能管理

    Institute of Scientific and Technical Information of China (English)

    陈丽; 赵彦敏; 张泉斌

    2015-01-01

    该系统采用NXP公司的MFRC522射频识别芯片和STC公司的STC12C5A60S2单片机为主要构架,实现了对公共电源使用权限的智能管理。系统利用芯片MFRC522与电子标签卡通信,将读出的序列号发送给单片机进行分析处理,从而实现用户身份的智能识别。针对不同的识别结果,系统对公共电源输出进行相应的控制,对合法用户进行供电,非法用户则不予供电。系统还集成了断电监测、短路保护等功能。从测试结果来看,该系统能为用户提供便捷、稳定、廉价的电源权限管理解决方案。%The system uses the MFRC522 NXP radio frequency identiifcation chip and STC company's STC12C5A60S2 microcontroller as the main framework, to achieve the public power of the use of intelligent management. The system uses chip MFRC522 and electronic label card to communicate with the serial number, and the serial number is transmitted to the single chip microcomputer for analysis and processing, so as to realize the intelligent recognition of user's identity. For different results, the system of the public power output for the corresponding control, power supply for legitimate users, illegal users are not power. The system also integrates the functions of power failure monitoring, short circuit protection and so on. From the test results, the system can provide users with convenient, stable, affordable power management solutions.

  3. 岸基高频地波雷达资料后处理技术研究%Study on the post-processing technology of High Frequency radar data

    Institute of Scientific and Technical Information of China (English)

    杨锦坤; 苗庆生; 刘玉龙

    2015-01-01

    综述了国内外高频地波雷达发展和研究现状,系统介绍了岸基高频地波雷达资料接收、预处理、计算机自动质量控制、可视化人机交互审核和标准化输出等后处理工作内容与流程,详细阐述并以示例验证了岸基高频地波雷达资料非法码检验、常规范围检验、相关性检验、气候学检验、统计学检验等质量控制方法和通过实测矢量场图、网格化矢量场图进行资料深入审核的原理与方法,最后较为具体的提出了岸基高频地波雷达资料后处理系统的逻辑、物理和功能架构设计及技术指标和运行环境.研究成果紧密贴合我国海洋观测网建设运行实际需求,对于我国岸基高频地波雷达资料后处理技术水平和能力提升,具有科学和重要的技术参考价值.%This paper reviews the domestic and overseas development of HF radar, then systematically introduces HF radar data reception, preprocessing, computer automated quality control, visualization, human-computer visual interaction check and standard output and other post-processing contents and processes, then elaborates quality control methods, such as illegal code testing, range test, correlation test, climatology testing, statistical tests and verification with examples and principles of data check by plotting measured and gridded vector field. Finally this paper puts forward technical specifications and operating environment and architecture design of post-processing system in the field of logic, physics and function. Researches fit closely with the actual demand of construction of marine observing network, which has scientific and important technical reference value for the technology and capacity building of HF radar data post-processing.

  4. Insider protection technology developments

    Energy Technology Data Exchange (ETDEWEB)

    Foesch, J.; Bortniak, P.; Waddoups, I.

    1994-08-01

    Sandia National Laboratories evaluates and develops new techniques and technologies to ensure the integrity of special nuclear material (SNM) against potential insider threats. We have evaluated several types of sensor technologies and subsystems to monitor and/or track materials and personnel. This past year`s effort has been directed at characterizing commercial developments that meet the Department of Energy`s (DOE) needs in some of these areas. Some of these evaluations are complete and some are still in progress. This paper discusses our work with infrared light (IR), radio frequency (RF), and RF proximity technologies. After these technologies are judged to be applicable to DOE`s needs, we incorporate them into the generic, real time, personnel tracking and material monitoring system.

  5. Accelerator Technology Division

    Science.gov (United States)

    1992-04-01

    In fiscal year (FY) 1991, the Accelerator Technology (AT) division continued fulfilling its mission to pursue accelerator science and technology and to develop new accelerator concepts for application to research, defense, energy, industry, and other areas of national interest. This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; (Phi) Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

  6. Terrestrial Digital Television Broadcast Single Frequency Network (SFN) Group Gateway Key Technologies and Test Methods%地面数字电视广播单频网(SFN)组网关键技术与测试方法

    Institute of Scientific and Technical Information of China (English)

    杨延冬; 呼和; 黄艳萍; 吕倩

    2014-01-01

    TV with the single frequency network will also DTMB standard promotion and inter-nationalization have been adopted by other more countries and regions , its promotion prospects .

  7. Term frequency inverse document frequency (TF-IDF) technique and ...

    African Journals Online (AJOL)

    Term frequency inverse document frequency (TF-IDF) technique and artificial neural ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL ... Electronic mail contents are extracted and Term Frequency Inverse ...

  8. Low Frequency Radio Astronomy Summary: A Festschrift For Bill Erickson

    Science.gov (United States)

    Clark, B. G.; Kassim, N. E.; Perez, M. R.

    2005-12-01

    The science and technological issues presented at this workshop in honor of Bill Erickson's 74th birthday, are certainly opening up a new window of astronomical observations at the low end of the radio frequency spectrum. We briefly review some of the contributions concentrating our comments on the topics of science, technology, and history.

  9. Frequency Standards and Metrology

    Science.gov (United States)

    Maleki, Lute

    2009-04-01

    Preface / Lute Maleki -- Symposium history / Jacques Vanier -- Symposium photos -- pt. I. Fundamental physics. Variation of fundamental constants from the big bang to atomic clocks: theory and observations (Invited) / V. V. Flambaum and J. C. Berengut. Alpha-dot or not: comparison of two single atom optical clocks (Invited) / T. Rosenband ... [et al.]. Variation of the fine-structure constant and laser cooling of atomic dysprosium (Invited) / N. A. Leefer ... [et al.]. Measurement of short range forces using cold atoms (Invited) / F. Pereira Dos Santos ... [et al.]. Atom interferometry experiments in fundamental physics (Invited) / S. W. Chiow ... [et al.]. Space science applications of frequency standards and metrology (Invited) / M. Tinto -- pt. II. Frequency & metrology. Quantum metrology with lattice-confined ultracold Sr atoms (Invited) / A. D. Ludlow ... [et al.]. LNE-SYRTE clock ensemble: new [symbol]Rb hyperfine frequency measurement - spectroscopy of [symbol]Hg optical clock transition (Invited) / M. Petersen ... [et al.]. Precise measurements of S-wave scattering phase shifts with a juggling atomic clock (Invited) / S. Gensemer ... [et al.]. Absolute frequency measurement of the [symbol] clock transition (Invited) / M. Chwalla ... [et al.]. The semiclassical stochastic-field/atom interaction problem (Invited) / J. Camparo. Phase and frequency noise metrology (Invited) / E. Rubiola ... [et al.]. Optical spectroscopy of atomic hydrogen for an improved determination of the Rydberg constant / J. L. Flowers ... [et al.] -- pt. III. Clock applications in space. Recent progress on the ACES mission (Invited) / L. Cacciapuoti and C. Salomon. The SAGAS mission (Invited) / P. Wolf. Small mercury microwave ion clock for navigation and radioScience (Invited) / J. D. Prestage ... [et al.]. Astro-comb: revolutionizing precision spectroscopy in astrophysics (Invited) / C. E. Kramer ... [et al.]. High frequency very long baseline interferometry: frequency standards and

  10. Micromachined components for terahertz frequency applications

    CERN Document Server

    Parkhurst, G M

    2001-01-01

    lithographic technology for the fabrication of terahertz circuits, the integration of an active solid state device is explored. The device chosen for this work is the resonant tunnel diode (RTD). Some background discussion of the operation of these devices as oscillators is presented, and techniques for full integration of devices into a waveguide, using processes which are completely compatible with semiconductor manufacturing technology, are explored experimentally. Two main problems prevent the use of the terahertz frequency band (defined for present purposes as 100GHz - 10THz) in a wider range of applications. The first is the absence of a convenient, cheap solid-state source of power and the second is the significant cost of conventional passive components. In this Thesis, the second issue is addressed in detail, describing developments in the fabrication and characterisation of low cost lithographically-produced terahertz frequency passive components. An extensive study of the use of ultra-thick UV phot...

  11. Direct frequency comb laser cooling and trapping

    CERN Document Server

    Jayich, A M; Campbell, W C

    2016-01-01

    Continuous wave (CW) lasers are the enabling technology for producing ultracold atoms and molecules through laser cooling and trapping. The resulting pristine samples of slow moving particles are the de facto starting point for both fundamental and applied science when a highly-controlled quantum system is required. Laser cooled atoms have recently led to major advances in quantum information, the search to understand dark energy, quantum chemistry, and quantum sensors. However, CW laser technology currently limits laser cooling and trapping to special types of elements that do not include highly abundant and chemically relevant atoms such as hydrogen, carbon, oxygen, and nitrogen. Here, we demonstrate that Doppler cooling and trapping by optical frequency combs may provide a route to trapped, ultracold atoms whose spectra are not amenable to CW lasers. We laser cool a gas of atoms by driving a two-photon transition with an optical frequency comb, an efficient process to which every comb tooth coherently cont...

  12. Single frequency intracavity SRO

    DEFF Research Database (Denmark)

    Abitan, Haim; Buchhave, Preben

    2000-01-01

    Summary form only given. A single resonance optical parametric oscillator (SRO) is inserted intracavity to a CW high power, single frequency, and ring Nd:YVO4 laser. We obtain a stable single frequency CW SRO with output at 1.7-1.9 μm (idler) and a resonating signal at 2.3-2.6 μm. The behavior...... of the two coupled resonators is simulated and the output power from the SRO is described as a function of the diode pumping power supplied to the Nd:YVO4 laser....

  13. Mid-frequency readers

    OpenAIRE

    Nation, Ian Stephen Paul; Anthony, Laurence

    2013-01-01

    This article describes a new free extensive reading resource for learning the mid-frequency words of English and for reading well known texts with minor vocabulary adaptation. A gap exists between the end of graded readers at around 3,000 word families and the vocabulary size needed to read unsimplified texts at around 8,000 word families. Mid-frequency readers are designed to fill this gap. They consist of texts from Project Gutenberg adapted for learners with a vocabulary size of 4,000 word...

  14. Satellite communication antenna technology

    Science.gov (United States)

    Mittra, R. (Editor); Imbriale, W. A. (Editor); Maanders, E. J. (Editor)

    1983-01-01

    A general overview of current technology in the field of communication satellite antennas is presented. Among the topics discussed are: the design of multiple beam systems; frequency reuse; and polarization control of antenna measurements. Consideration is also given to: contour beam synthesis; dual shaped reflector synthesis; beam shaping; and offset reflector design. The applications of the above technologies to present and future generations of communications satellites is considered, with emphasis given to such systems as: the Intelsats; the Defense Satellite Communications System, (DSCS-III); Satellite Business System (SBS), and Comstar.

  15. Metagenome Fragment Classification Using -Mer Frequency Profiles

    OpenAIRE

    Gail Rosen; Elaine Garbarine; Diamantino Caseiro; Robi Polikar; Bahrad Sokhansanj

    2008-01-01

    A vast amount of microbial sequencing data is being generated through large-scale projects in ecology, agriculture, and human health. Efficient high-throughput methods are needed to analyze the mass amounts of metagenomic data, all DNA present in an environmental sample. A major obstacle in metagenomics is the inability to obtain accuracy using technology that yields short reads. We construct the unique -mer frequency profiles of 635 microbial genomes publicly available as of February 2008....

  16. Very High Frequency Switch-Mode Power Supplies

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre

    The importance of technology and electronics in our daily life is constantly increasing. At the same time portability and energy efficiency are currently some of the hottest topics. This creates a huge need for power converters in a compact form factor and with high efficiency, which can supply...... these electronic devices. This calls for new technologies in order to miniaturize the power electronics of today. One way to do this is by increasing the switching frequency dramatically and develop very high frequency switch mode power supplies. If these converters can be designed to operate efficiently, a huge...... of technologies for very high frequency switch mode power supplies. At these highly elevated frequencies normal bulky magnetics with heavy cores consisting of rare earth materials, can be replaced by air core inductors embedded in the printed circuit board. This is investigated thoroughly and both spirals...

  17. Microresonator-based optical frequency combs.

    Science.gov (United States)

    Kippenberg, T J; Holzwarth, R; Diddams, S A

    2011-04-29

    The series of precisely spaced, sharp spectral lines that form an optical frequency comb is enabling unprecedented measurement capabilities and new applications in a wide range of topics that include precision spectroscopy, atomic clocks, ultracold gases, and molecular fingerprinting. A new optical frequency comb generation principle has emerged that uses parametric frequency conversion in high resonance quality factor (Q) microresonators. This approach provides access to high repetition rates in the range of 10 to 1000 gigahertz through compact, chip-scale integration, permitting an increased number of comb applications, such as in astronomy, microwave photonics, or telecommunications. We review this emerging area and discuss opportunities that it presents for novel technologies as well as for fundamental science.

  18. Multiband frequency selective surface

    Science.gov (United States)

    Wu, Te-Kao

    1998-10-01

    This paper addresses the similarity of microwave/millimeter wave frequency selective surfaces (FSS) to optical filters. Specifically, the design approaches of the 4-band FSSs developed for NASA's CASSINI high gain antenna are described in detail. Representative RF test results are given to demonstrate the validity of these designs. These design approaches are very general and can be applied to multiband optical filters.

  19. 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...

  20. Frequency of orthodontic extraction

    Directory of Open Access Journals (Sweden)

    Camila de S. Dardengo

    2016-02-01

    Full Text Available Introduction: The option of dental extraction for orthodontic purposes has been debated for more than 100 years, including periods when it was widely used in treatment, including the present, during which other methods are used to avoid dental extractions. The objective was to analyze the frequency of tooth extraction treatment performed between 1980 and 2011 at the Orthodontic Clinic of Universidade Estadual do Rio de Janeiro (UERJ. Material and Methods: The clinical records of 1484 patients undergoing orthodontic treatment were evaluated. The frequency of extractions was evaluated with regard to sex, Angle's classification, the different combinations of extractions and the period when orthodontic treatment began. Chi-square test was used to determine correlations between variables, while the chi-square test for trends was used to assess the frequency of extractions over the years. Results: There was a reduction of approximately 20% in the frequency of cases treated with tooth extraction over the last 32 years. The most frequently extracted teeth were first premolars. Patients with Class I malocclusion showed fewer extractions, while Class II patients underwent a higher number of extraction treatment. There were no statistically significant differences with regard to sex. Conclusion: New features introduced into the orthodontic clinic and new esthetic concepts contributed to reducing the number of cases treated with dental extractions. However, dental extractions for orthodontic purposes are still well indicated in certain cases.

  1. All-frequency reflectionlessness

    CERN Document Server

    Philbin, T G

    2016-01-01

    We derive planar permittivity profiles that do not reflect perpendicularly exiting radiation of any frequency. The materials obey the Kramers-Kronig relations and have no regions of gain. Reduction of the Casimir force by means of such materials is also discussed.

  2. Multiple Frequency Parametric Sonar

    Science.gov (United States)

    2015-09-28

    300003 1 MULTIPLE FREQUENCY PARAMETRIC SONAR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...beams. However, the multiple nonlinear interactions are not taken advantage of in order to generate additional efficiencies, bandwidth, and SNR...array. [0050] It will be understood that many additional changes in details, materials , steps, and arrangements of parts which have been described

  3. Technology Maturity is Technology Superiority

    Science.gov (United States)

    2008-09-09

    Dominant Air Power: Design For Tomorrow…Deliver Today 2 TECHNOLOGY MATURITY CONFERENCE • ONE DEFINITION OF MATURITY – GOOD JUDGEMENT COMES FROM...EXPERIENCE—EXPERIENCE COMES FROM BAD JUDGEMENT Dominant Air Power: Design For Tomorrow…Deliver Today 3 TECHNOLOGY MATURITY CONFERENCE • THIS WILL BE A...2008 TECHNOLOGY MATURITY CONFERENCE “ TECHNOLOGY MATURITY IS TECHNOLOGY SUPERIORITY” Aeronautical Systems Center Dr. Tom Christian ASC/EN, WPAFB OH

  4. HIGHER FREQUENCY ULTRASONIC LIGHT MODULATORS.

    Science.gov (United States)

    LIGHT), (* MODULATORS , (*ULTRASONIC RADIATION, MODULATORS ), OPTICAL COMMUNICATIONS, BANDWIDTH, TRANSDUCERS, HIGH FREQUENCY, VERY HIGH FREQUENCY, ATTENUATION, DATA PROCESSING, OPTICAL EQUIPMENT, ANALOG COMPUTERS, THEORY.

  5. Microwave Frequency Multiplier

    Science.gov (United States)

    Velazco, J. E.

    2017-02-01

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

  6. Frequency-domain trade-offs for dielectric elastomer generators

    Science.gov (United States)

    Zanini, Plinio; Rossiter, Jonathan M.; Homer, Martin

    2017-04-01

    Dielectric Elastomer Generators (DEGs) are an emerging energy harvesting technology based on a the cyclic stretching of a rubber-like membrane. However, most design processes do not take into account different excitation frequencies; thus limits the applicability studies since in real-world situations forcing frequency is not often constant. Through the use of a practical design scenario we use modeling and simulation to determine the material frequency response and, hence, carefully investigate the excitation frequencies that maximize the performance (power output, efficiency) of DEGs and the factors that influence it.

  7. Globalization & technology

    DEFF Research Database (Denmark)

    Narula, Rajneesh

    Technology and globalization are interdependent processes. Globalization has a fundamental influence on the creation and diffusion of technology, which, in turn, affects the interdependence of firms and locations. This volume examines the international aspect of this interdependence at two levels...

  8. Living Technology

    DEFF Research Database (Denmark)

    2010-01-01

    This book is aimed at anyone who is interested in learning more about living technology, whether coming from business, the government, policy centers, academia, or anywhere else. Its purpose is to help people to learn what living technology is, what it might develop into, and how it might impact...... our lives. The phrase 'living technology' was coined to refer to technology that is alive as well as technology that is useful because it shares the fundamental properties of living systems. In particular, the invention of this phrase was called for to describe the trend of our technology becoming...... increasingly life-like or literally alive. Still, the phrase has different interpretations depending on how one views what life is. This book presents nineteen perspectives on living technology. Taken together, the interviews convey the collective wisdom on living technology's power and promise, as well as its...

  9. Living Technology

    DEFF Research Database (Denmark)

    2010-01-01

    This book is aimed at anyone who is interested in learning more about living technology, whether coming from business, the government, policy centers, academia, or anywhere else. Its purpose is to help people to learn what living technology is, what it might develop into, and how it might impact...... our lives. The phrase 'living technology' was coined to refer to technology that is alive as well as technology that is useful because it shares the fundamental properties of living systems. In particular, the invention of this phrase was called for to describe the trend of our technology becoming...... increasingly life-like or literally alive. Still, the phrase has different interpretations depending on how one views what life is. This book presents nineteen perspectives on living technology. Taken together, the interviews convey the collective wisdom on living technology's power and promise, as well as its...

  10. Emerging Technologies

    OpenAIRE

    Salgar, S. M.

    2004-01-01

    Phenomenal advancements have taken place in the field of Information and communication technologies in the last decade. Spectacular and innovative changes are expected to take place in these fields in coming decade. Networking technologies are going through a sea change. This paper enumerates the likely networking technologies which are emerging, particularly WLANs. Most of the personal communication in the country will be through cellular/ mobile technologies, which are also covered in the p...

  11. [Frequency dependance of compliance].

    Science.gov (United States)

    Gayrard, P

    1975-01-01

    Resistance of peripheral or "small" airways is only a small part of the total pulmonary resistance (Raw). Even considerable obstruction in these airways will have little effect on total resistance. Conversely this will lead to inequality in the time constants of units in parallel, and dynamic lung compliance (C dyn) shall fall as respiratory frequence increases. C dyn is measured from simultaneous recordings of transpulmonary pressure (esophageal balloon) and volume obtained from a volume displacement plethysmograph. If Raw and static compliance are found to be normal, the frequency dependance of compliance will result from peripheral airway obstruction only. Early stages of chronic airway obstruction can be established by this method. However this appear not suitable for wide-scale studies.

  12. Soulful Technologies

    DEFF Research Database (Denmark)

    Fausing, Bent

    2010-01-01

    or anthropomorphism is important for the branding of new technology. Technology is seen as creating a techno-transcendence towards a more qualified humanity which is in contact with fundamental human values like intuition, vision, and sensing; all the qualities that technology, industrialization, and rationalization...

  13. Technology Tiers

    DEFF Research Database (Denmark)

    Karlsson, Christer

    2015-01-01

    A technology tier is a level in a product system: final product, system, subsystem, component, or part. As a concept, it contrasts traditional “vertical” special technologies (for example, mechanics and electronics) and focuses “horizontal” feature technologies such as product characteristics...

  14. Technology Tiers

    DEFF Research Database (Denmark)

    Karlsson, Christer

    2015-01-01

    A technology tier is a level in a product system: final product, system, subsystem, component, or part. As a concept, it contrasts traditional “vertical” special technologies (for example, mechanics and electronics) and focuses “horizontal” feature technologies such as product characteristics...

  15. Assistive Technologies

    Science.gov (United States)

    Auat Cheein, Fernando A., Ed.

    2012-01-01

    This book offers the reader new achievements within the Assistive Technology field made by worldwide experts, covering aspects such as assistive technology focused on teaching and education, mobility, communication and social interactivity, among others. Each chapter included in this book covers one particular aspect of Assistive Technology that…

  16. Frequency selective bolometers

    DEFF Research Database (Denmark)

    Kowitt, M.S.; Fixsen, D.J.; Goldin, A.

    1996-01-01

    -dimensional transmission-line model. Instruments based on FSB technology should have several advantages over current multiband bolometric radiometers including smaller and more compact cryogenic optics; reduced demands on cryostat size and weight, high coupling efficiency, minimum constraints on the geometry in the focal...

  17. Radio frequency ion source

    CERN Document Server

    Shen Guan Ren; Gao Fu; LiuNaiYi

    2001-01-01

    The study on Radio Frequency Ion Source is mainly introduced, which is used for CIAE 600kV ns Pulse Neutron Generator; and obtained result is also presented. The RF ion source consists of a diameter phi 25 mm, length 200 mm, coefficient of expansion =3.5 mA, beam current on target >=1.5 mA, beam spot =100 h.

  18. Frequency steerable acoustic transducers

    Science.gov (United States)

    Senesi, Matteo

    Structural health monitoring (SHM) is an active research area devoted to the assessment of the structural integrity of critical components of aerospace, civil and mechanical systems. Guided wave methods have been proposed for SHM of plate-like structures using permanently attached piezoelectric transducers, which generate and sense waves to evaluate the presence of damage. Effective interrogation of structural health is often facilitated by sensors and actuators with the ability to perform electronic, i.e. phased array, scanning. The objective of this research is to design an innovative directional piezoelectric transducer to be employed for the localization of broadband acoustic events, or for the generation of Lamb waves for active interrogation of structural health. The proposed Frequency Steerable Acoustic Transducers (FSATs) are characterized by a spatial arrangement of active material which leads to directional characteristics varying with frequency. Thus FSATs can be employed both for directional sensing and generation of guided waves without relying on phasing and control of a large number of channels. The analytical expression of the shape of the FSATs is obtained through a theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. The FSAT configurations analyzed in this work are a quadrilateral array and a geometry which corresponds to a spiral in the wavenumber domain. The quadrilateral array is experimentally validated, confirming the concept of frequency-dependent directionality. Its limited directivity is improved by the Wavenumber Spiral FSAT (WS-FSAT), which, instead, is characterized by a continuous frequency dependent directionality. Preliminary validations of the WS-FSAT, using a laser doppler vibrometer, are followed by the implementation of the WS-FSAT as a properly shaped piezo transducer. The prototype is first used for localization of acoustic broadband sources. Signal processing

  19. Air Force Laboratory’s 2005 Technology Milestones

    Science.gov (United States)

    2006-01-01

    as well as advanced high-power cooling technology demonstrations required for high-power microwave anode. Background AFRL researches, develops... germination period has not prevented physicists, chemists, biologists, and doctors from quickly embracing the technology. Payoff AFRL sponsored Dr. James...electromagnetic waves, THz frequencies are located between microwaves and infrared frequencies. THz frequencies are 100 to 1,000 times lower in frequency than

  20. 三维与二维高频超声技术应用于针灸穴位定位的可行性研究%Study of locating acupuncture point by high frequency 3-dimensional and 2-dimensional ultrasonic technology

    Institute of Scientific and Technical Information of China (English)

    高东雯; 肖沪生; 徐智章; 张爱宏; 徐芳; 银浩强; 任亚娟; 彭欣; 王奇

    2013-01-01

    Objective:High frequency 3-dimensional and 2-dimensional ultrasonic technology were applied on pork acupuncture research,discuss the location feasibility of New Zealand big ear rabbits and human body by this methods.Methods:①The acupuncture needle was pierced into the pork.The three dimensional probe was used to observe the needle position synchronously from longitudinal section,cross-section and coronal section.Evaluate the accuracy of three dimensional ultrasonic localization.②The needle A was fixed into pork and its needlepoint was set as the bull' s-eye.The needle B was guided by Ultrasound to the bull's-eye and the needle B was blind acupunctured to the bull's-eye 30 times.The distance of two tips was measured.Analyze the accuracy of blind acupuncture.③Acupuncture needles were pierced into Zusanli which located in the dorsolateral side of the double legs of four New Zealand big ear rabbits.The accuracy of the location of acupuncture needles were real-time,precisely observed.④The 15 different acupuncture points and 30 same acupuncture points of 15 volunteers were detected by ultrasonography when the ultrasound sectional images in accordance with meridian anatomy sectional picture and the movement of acupuncture needle pinpoint was observed by high-frequency ultrasound dynamically.Results:The piercing point of pork was precisely located by 3-dimension high frequency ultrasonic technology.The needles spatial location can be displayed accurately.The piercing point of pork and the Zusanli of New Zealand big ear rabbits,15 different acupuncture points and 30 same acupuncture points of 15 volunteers were accurately located by 2-dimensional high frequency ultrasonic technology.Conclusion:Locating the acupuncture point by high frequency ultrasonic technology has precise,intuitive,dynamic,simple,inexpensive characteristics and high clinical value.It should be used as the acupuncture point standard of human body.%目的:应用三维及二维高频超声技术对

  1. Orthogonal Frequency Division Multiplexing System with Frequency Offset Estimation

    Directory of Open Access Journals (Sweden)

    Meghashree D.Nimje

    2013-03-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM system, use a large number of parallel narrowband subcarriers instead of a single wide-band carrier to transport information. Orthogonal frequency division multiplexing is the modulation technique use in digital communication systems . Carrier frequency offset occurs due to Doppler effect or noise. Carrier frequency offsets (CFOs is the Offset between the transmitter and the receiver oscillators .CFO damages the orthogonality of the carries ,resulting in degradation of the systems performance. Carrier frequency offset estimation method is discussed in this paper. In this paper one complex training sequence use, which can effectively estimate carrier frequency offset in the time domain and frequency domain. Here fine and coarse frequency is estimated to improve the improve the system performance. This paper shows the estimation range for frequency offset can be improve to large extent..

  2. Sensemaking technologies

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    Research scope: The scope of the project is to study technological implementation processes by using Weick's sensemaking concept (Weick, 1995). The purpose of using a social constructivist approach to investigate technological implementation processes is to find out how new technologies transform......, Orlikowski 2000). Viewing the use of technology as a process of enactment opens up for investigating the social processes of interpreting new technology into the organisation (Orlikowski 2000). The scope of the PhD project will therefore be to gain a deeper understanding of how the enactment of new...... & Brass, 1990; Kling 1991; Orlikowski 2000). It also demonstrates that technology is a flexible variable adapted to the organisation's needs, culture, climate and management philosophy, thus leading to different uses and outcomes of the same technology in different organisations (Barley 1986; 1990...

  3. Radio frequency science considerations. [technology utilization of telecommunications system

    Science.gov (United States)

    Croft, T. A.

    1974-01-01

    Use of the 400 MHz telecommunications system to obtain scientific information, to provide backup information for the experiments flown, and to obtain measurements which aid in designing future probes is considered. Recommended objectives of such a program are summarized and include: measure 400 MHz amplitude to determine adsorption and perhaps scintillation (if data rate permits); measure noise strength near 400 MHz to reexamine 400 MHz choice and to observe thermal, cosmic, and local synchrotron noise trends; probe VSWR sensing to monitor integrity of system, icing, and possible plasma effects; after the probe is finished, have the bus radio occultation in the same region where the probe fell to evaluate the occultation.

  4. Advanced packaging technology for high frequency photonic applications

    Energy Technology Data Exchange (ETDEWEB)

    Armendariz, M.G.; Hadley, G.R.; Warren, M.E.

    1996-03-01

    An advanced packaging concept has been developed for optical devices. This concept allows multiple fibers to be coupled to photonic integrated circuits, with no fiber penetration of the package walls. The principles used to accomplish this concept involves a second-order grating to couple light in or out of the photonic circuit, and a binary optic lens which receives this light and focuses it into a single-mode optical fiber. Design, fabrication and electrical/optical measurements of this packaging concept are described.

  5. Nanoscale Imaging Technology for THz Frequency Transmission Microscopy

    Science.gov (United States)

    2014-12-16

    Microscopy, Analytical Chemistry , (06 2013): 0. doi: 10.1021/ac4010088 Yung Yu Wang, Peter J. Burke. Polyelectrolyte multilayer electrostatic gating of...C. G. Densmore, S. K. Doorn, P. J. Burke. Effect of source, surfactant , and deposition process on electronic properties of nanotube arrays, (09

  6. Ohmic Contacts for Technology for Frequency Agile Digitally Synthesized Transmitters

    Science.gov (United States)

    2010-07-01

    Catalyzed by Ru) Gold potassium cyanide 0.2 g/L Hydrazine hydrate 4ml/L NaOH (pH adjustment) As needed PH 12.2 Temperature 70 - 80°C Table V. Second...electroless Au bath (auto-catalytic). [7] Au Bath #2 (Auto-catalytic) Gold potassium cyanide 5.8 g/L Potassium cyanide 6.5 g/L KOH 11.2 g/L KBH4...result in a non- uniform plating potential (and a non-uniform deposition rate) across the wa- fer. Alternatively, a selective electroless process can

  7. Manufacturing Technology Study on Radio Frequency Power Modules Packaging Techniques.

    Science.gov (United States)

    1981-01-01

    transmitter, without adequate waterproofing procedures for the transducer cables. No detailed mapping was carried out, since no mechanical carriage was... cosmetic and does not affect hermetic seal of module. A.7 Final Electrical Test Method: Test performed on computer controlled automatic module test...dull gray due to reaction to salt environment. Discoloration is cosmetic only since solder coating is used to prevent oxidation of copper runs. Gold

  8. Appropriate Technology as Indian Technology.

    Science.gov (United States)

    Barry, Tom

    1979-01-01

    Describes the mounting enthusiasm of Indian communities for appropriate technology as an inexpensive means of providing much needed energy and job opportunities. Describes the development of several appropriate technology projects, and the goals and activities of groups involved in utilizing low scale solar technology for economic development on…

  9. DEMODULATION OF FREQUENCY OR SPACE MODULATED LIGHT.

    Science.gov (United States)

    LIGHT , DEMODULATION), (*OPTICAL COMMUNICATIONS, FREQUENCY MODULATION), (*FREQUENCY MODULATION, LIGHT ), OPTICAL TRACKING, BEAMS(ELECTROMAGNETIC), DEFLECTION, MICROWAVE FREQUENCY, ELECTRON BEAMS, PHOTOCATHODES

  10. Resonance frequency analysis

    Directory of Open Access Journals (Sweden)

    Rajiv K Gupta

    2011-01-01

    Full Text Available Initial stability at the placement and development of osseointegration are two major issues for implant survival. Implant stability is a mechanical phenomenon which is related to the local bone quality and quantity, type of implant, and placement technique used. The application of a simple, clinically applicable, non-invasive test to assess implant stability and osseointegration is considered highly desirable. Resonance frequency analysis (RFA is one of such techniques which is most frequently used now days. The aim of this paper was to review and analyze critically the current available literature in the field of RFA, and to also discuss based on scientific evidence, the prognostic value of RFA to detect implants at risk of failure. A search was made using the PubMed database to find all the literature published on "Resonance frequency analysis for implant stability" till date. Articles discussed in vivo or in vitro studies comparing RFA with other methods of implant stability measurement and articles discussing its reliability were thoroughly reviewed and discussed. A limited number of clinical reports were found. Various studies have demonstrated the feasibility and predictability of the technique. However, most of these articles are based on retrospective data or uncontrolled cases. Randomized, prospective, parallel-armed longitudinal human trials are based on short-term results and long-term follow up are still scarce in this field. Nonetheless, from available literature, it may be concluded that RFA technique evaluates implant stability as a function of stiffness of the implant bone interface and is influenced by factors such as bone type, exposed implant height above the alveolar crest. Resonance frequency analysis could serve as a non-invasive diagnostic tool for detecting the implant stability of dental implants during the healing stages and in subsequent routine follow up care after treatment. Future studies, preferably randomized

  11. Applications of Radio Frequency Identification (RFID) in Mining Industries

    Science.gov (United States)

    Khairul Nizam Mahmad, Mohd; Z, Mohd Remy Rozainy M. A.; Baharun, Norlia

    2016-06-01

    RFID technology has recently become a dream of many companies or organizations because of its strategic potential in transforming mining operations. Now is the perfect time, for RFID technology arise as the next revolution in mining industries. This paper will review regarding the application of RFID in mining industries and access knowledge regarding RFID technology and overseen the opportunity of this technology to become an importance element in mining industries. The application of Radio-Frequency Identification (RFID) in mining industries includes to control of Personal Protective Equipment (PPE), control of personnel to access mining sites and RFID solutions for tracking explosives.

  12. Microwave Frequency Polarizers

    Science.gov (United States)

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

    2013-01-01

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

  13. Frequency Dependent Attenuation Revisited

    CERN Document Server

    Richard, Kowar; Xavier, Bonnefond

    2009-01-01

    The work is inspired by thermo-and photoacoustic imaging, where recent efforts are devoted to take into account attenuation and varying wave speed parameters. In this paper we study causal equations describing propagation of attenuated pressure waves. We review standard models like frequency power laws and and the thermo-viscous equation. The lack of causality of standard models in the parameter range relevant for photoacoustic imaging requires to derive novel equations. The main ingredients for deriving causal equations are the Kramers-Kronig relation and the mathematical concept of linear system theory. The theoretical results of this work are underpined by numerical experiments.

  14. High frequency electromagnetic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Daily, W.; Ramirez, A.; Ueng, T.; Latorre, R.

    1989-09-01

    An experiment was conducted in G Tunnel at the Nevada Test Site to evaluate high frequency electromagnetic tomography as a candidate for in situ monitoring of hydrology in the near field of a heater placed in densely welded tuff. Tomographs of 200 MHz electromagnetic permittivity were made for several planes between boreholes. Data were taken before the heater was turned on, during heating and during cooldown of the rockmass. This data is interpreted to yield maps of changes in water content of the rockmass as a function of time. This interpretation is based on laboratory measurement of electromagnetic permittivity as a function of water content for densely welded tuff. 8 refs., 6 figs.

  15. Lunch frequency among adolescents

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Krølner, Rikke

    2016-01-01

    frequency was most common among students who were boys, 13- and 15-year-olds, from medium and low family social class, descendants of immigrants, living in a single-parent family and in a reconstructed family. School-level analyses suggested that having access to a canteen at school was associated with low...... students appears to be largely influenced by sociodemographic factors. Additionally, the presence of an adult during lunch breaks promotes frequent lunch consumption while availability of a canteen may discourage frequent lunch consumption. These findings vary between older and younger students....

  16. Roller Bearing Health Monitoring Using CPLE Frequency Analysis Method

    Science.gov (United States)

    Jong, Jen-Yi; Jones, Jess H.

    2007-01-01

    This paper describes a unique vibration signature analysis technique Coherence Phase Line Enhancer (CPLE) Frequency Analysis - for roller bearing health monitoring. Defects of roller bearing (e.g. wear, foreign debris, crack in bearing supporting structure, etc.) can cause small bearing characteristic frequency shifts due to minor changes in bearing geometry. Such frequency shifts are often too small to detect by the conventional Power Spectral Density (PSD) due to its frequency bandwidth limitation. This Coherent Phase Line Enhancer technology has been evolving over the last few years and has culminated in the introduction of a new and novel frequency spectrum which is fully described in this paper. This CPLE technology uses a "key phasor" or speed probe as a preprocessor for this analysis. With the aid of this key phasor, this CPLE technology can develop a two dimensional frequency spectrum that preserves both amplitude and phase that is not normally obtained using conventional frequency analysis. This two-dimensional frequency transformation results in several newly defined spectral functions; i. e. CPLE-PSD, CPLE-Coherence and the CPLE-Frequency. This paper uses this CPLE frequency analysis to detect subtle, low level bearing related signals in the High Pressure Fuel Pump (HPFP) of the Space Shuttle Main Engine (SSME). For many rotating machinery applications, a key phasor is an essential measurement that is used in the detection of bearing related signatures. There are times however, when a key phasor is not available; i. e. during flight of any of the SSME turbopumps or on the SSME High Pressure Oxygen Turbopump (HPOTP) where no speed probe is present. In this case, the CPLE analysis approach can still be achieved using a novel Pseudo Key Phasor (PKP) technique to reconstruct a 1/Rev PKP signal directly from external vibration measurements. This paper develops this Pseudo Key Phasor technique and applies it to the SSME vibration data.

  17. Time-frequency, bi-frequency detector analysis of noise technology radar

    OpenAIRE

    Heuschel, Eugene R.

    2006-01-01

    Enemy integrated air defense systems (IADS) using low probability of intercept (LPI) emitters can cause significant problems for suppression of enemy air defense (SEAD) techniques. New threat emitter configurations using low-power random noise modulation have a significant processing gain unavailable to non-cooperative intercept receivers. Consequently, the detection of these emitters can not be accomplished with conventional intercept receiver detection methods. This thesis examines the...

  18. Multiple frequency atmospheric radar techniques

    Science.gov (United States)

    Stitt, Gary Richard

    The use of multiple frequency coding to improve the vertical resolution of pulsed-Doppler very high frequency atmospheric radars, especially with regards to the two-frequency techniques known as frequency domain interferometry (FDI), is presented. This technique consists of transmitting alternate pulses on two distinct carrier frequencies. The two resulting time series are used to evaluate the normalized cross-correlation function, whose magnitude and phase are related to the thickness and position of a scattering layer. These same time series are also used to evaluate cross-spectra, which yield magnitude and phase values for each Doppler frequency component of the return signal.

  19. Frequency Population Growth Rate

    Directory of Open Access Journals (Sweden)

    Nouralah Salehi Asfiji

    2012-10-01

    Full Text Available The Solow growth model assumes that labor force grows exponentially. That is not a realistic assumption. In generalized logistic equations that describes more accurately population growth. Economic growth is not a smooth process. Real GDP has fluctuations in the growth rate. We call these fluctuations business cycles. Business cycle theory came about from the failures of classical economics in being able to illuminate on the causes of the Great Depression. The logistic growth model to explain changes in population growth rates are not. In this paper a new analysis of the population growth rate in the frequency space is described with mathematical logic and economic reasoning, so that, firstly, to a higher level of capital per capita, or at least equal to the Solow growth model reaches Second, the limits of saturation (Carrying-Capacity is not, and ultimately, population growth rates have an impact on long-term per capita amounts. The initial classic assumption is changed in this article based on the available frequencies in the population growth equation.

  20. Malaria haplotype frequency estimation.

    Science.gov (United States)

    Wigger, Leonore; Vogt, Julia E; Roth, Volker

    2013-09-20

    We present a Bayesian approach for estimating the relative frequencies of multi-single nucleotide polymorphism (SNP) haplotypes in populations of the malaria parasite Plasmodium falciparum by using microarray SNP data from human blood samples. Each sample comes from a malaria patient and contains one or several parasite clones that may genetically differ. Samples containing multiple parasite clones with different genetic markers pose a special challenge. The situation is comparable with a polyploid organism. The data from each blood sample indicates whether the parasites in the blood carry a mutant or a wildtype allele at various selected genomic positions. If both mutant and wildtype alleles are detected at a given position in a multiply infected sample, the data indicates the presence of both alleles, but the ratio is unknown. Thus, the data only partially reveals which specific combinations of genetic markers (i.e. haplotypes across the examined SNPs) occur in distinct parasite clones. In addition, SNP data may contain errors at non-negligible rates. We use a multinomial mixture model with partially missing observations to represent this data and a Markov chain Monte Carlo method to estimate the haplotype frequencies in a population. Our approach addresses both challenges, multiple infections and data errors.

  1. Nigerian Journal of Technological Development: Editorial Policies

    African Journals Online (AJOL)

    Nigerian Journal of Technological Development: Editorial Policies. Journal Home > About the ... Frequency. This journal published two issues, in one volume per year. ... Dept. of Mechanical Engineering,. Mississipi State University,. USA. Prof.

  2. Arbitrary optical frequency synthesis traced to an optical frequency comb

    Science.gov (United States)

    Cai, Zihang; Zhang, Weipeng; Yang, Honglei; Li, Yan; Wei, Haoyun

    2016-11-01

    An arbitrary optical frequency synthesizer with a broad tuning range and high frequency accuracy is presented. The system includes an external cavity diode laser (ECDL) as the output laser, an Erbium-doped optical frequency comb being a frequency reference, and a control module. The optical frequency from the synthesizer can be continuously tuned by the large-scale trans-tooth switch and the fine intra-tooth adjustment. Robust feedback control by regulating the current and PZT voltage enables the ECDL to phase-lock to the Erbium-doped optical frequency comb, therefore to keep stable frequency output. In the meanwhile, the absolute frequency of the synthesizer is determined by the repetition rate, the offset frequency and the beat frequency. All the phase lock loops in the system are traced back to a Rubidium clock. A powerful and friendly software is developed to make the operation convenient by integrating the functions of frequency setting, tuning, tracing, locking and measuring into a LabVIEW interface. The output frequency tuning span and the uncertainty of the system are evaluated as >6 THz and Ring-Down Spectroscopy.

  3. Sensemaking technologies

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    & Brass, 1990; Kling 1991; Orlikowski 2000). It also demonstrates that technology is a flexible variable adapted to the organisation's needs, culture, climate and management philosophy, thus leading to different uses and outcomes of the same technology in different organisations (Barley 1986; 1990......, Orlikowski 2000). Viewing the use of technology as a process of enactment opens up for investigating the social processes of interpreting new technology into the organisation (Orlikowski 2000). The scope of the PhD project will therefore be to gain a deeper understanding of how the enactment of new...

  4. Chemistry Technology

    Data.gov (United States)

    Federal Laboratory Consortium — Chemistry technology experts at NCATS engage in a variety of innovative translational research activities, including:Design of bioactive small molecules.Development...

  5. Mechanical control of a microrod-resonator optical frequency comb

    CERN Document Server

    Papp, Scott B; Diddams, Scott A

    2012-01-01

    Robust control and stabilization of optical frequency combs enables an extraordinary range of scientific and technological applications, including frequency metrology at extreme levels of precision, novel spectroscopy of quantum gases and of molecules from visible wavelengths to the far infrared, searches for exoplanets, and photonic waveform synthesis. Here we report on the stabilization of a microresonator-based optical comb (microcomb) by way of mechanical actuation. This represents an important step in the development of microcomb technology, which offers a pathway toward fully-integrated comb systems. Residual fluctuations of our 32.6 GHz microcomb line spacing reach a record stability level of $5\\times10^{-15}$ for 1 s averaging, thereby highlighting the potential of microcombs to support modern optical frequency standards. Furthermore, measurements of the line spacing with respect to an independent frequency reference reveal the effective stabilization of different spectral slices of the comb with a $&...

  6. Microwave transistor oscillator frequency tripling

    OpenAIRE

    B. A. Kotserzhynskyi

    2010-01-01

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

  7. Microwave transistor oscillator frequency tripling

    Directory of Open Access Journals (Sweden)

    B. A. Kotserzhynskyi

    2010-01-01

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

  8. An introduction to orthogonal frequency-division multiplexing

    OpenAIRE

    Edfors, Ove; Sandell, Magnus; van de Beek, Jan-Jaap; Landström, Daniel; Sjöberg, Frank

    1996-01-01

    This report is an introduction to orthogonal frequency-division multiplexing (OFDM). The focus is on signal processing areas pursued by our research group at Luleå University of Technology. We present an historical background and some frequently used system models. Typical areas of applications are also described, both wireless and wired. In addition to the general overview, the addressed areas include synchronization, channel estimation and channel coding. Both time and frequency synchroniza...

  9. Technology handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 3: Technology is part of a series of publications that presents articles featuring the whole spectrum of vacuum physics. This particular volume presents materials that deal with technology concerns in vacuum mechanics. The first material talks about the utilization of ceramic materials in the construction of vacuum devices. The next paper details the application of vacuum physics in soldering and brazing process. The last article deals with the utilization of vacuum technology in high frequency heating. The book will be of great use to professionals involved

  10. Frequency doubling crystals

    Science.gov (United States)

    Wang, Francis; Velsko, Stephan P.

    1989-01-01

    A systematic approach to the production of frequency conversion crystals is described in which a chiral molecule has attached to it a "harmonic generating unit" which contributes to the noncentrosymmetry of the molecule. Certain preferred embodiments of such harmonic generating units include carboxylate, guanadyly and imidazolyl units. Certain preferred crystals include L-arginine fluoride, deuterated L-arginine fluoride, L-arginine chloride monohydrate, L-arginine acetate, dithallium tartrate, ammonium N-acetyl valine, N-acetyl tyrosine and N-acetyl hydroxyproline. Chemical modifications of the chiral molecule, such as deuteration, halogenation and controlled counterion substitution are available to adapt the dispersive properties of a crystal in a particular wavelength region.

  11. Matsubara Frequency Sums

    CERN Document Server

    Kumar, Alok

    2010-01-01

    We cannot use directly the results of zero-temperature at finite temperature, for at finite temperature the average is to be carried over all highly degenerate excited states unlike zero-temperature average is only on unique ground state. One of the formal way to take into account the finite temperature into quantum field theory is due to Matsubara, to replace temporal component of eigenvalues $k_{4}$ by $\\omega_{n}=\\frac{2\\pi n}{\\beta}$ $(\\frac{2\\pi (n+{1/2})}{\\beta})$ with summation over all integer values of $n$. The summation is done with the infinite series expansion of $\\coth (\\pi y)$. With the chemical potential $\\mu$, $\\omega_{n}$ will be replaced by $\\omega_{n} - \\mu$ in the eigenvalues and the summation over $n$ cannot be done easily. Various methods exist to evaluate it. We use the infinite series expansion of $\\coth (\\pi y)$ to work operationally for such Matsubara frequency sums.

  12. Frequency mixing crystal

    Science.gov (United States)

    Ebbers, Christopher A.; Davis, Laura E.; Webb, Mark

    1992-01-01

    In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmoic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X.sub.2 Y(NO.sub.3).sub.5 .multidot.2 nZ.sub.2 o wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

  13. High Frequency Oscillatory Ventilation

    Directory of Open Access Journals (Sweden)

    AC Bryan

    1996-01-01

    Full Text Available High frequency oscillatory (HFO ventilation using low tidal volume and peak airway pressures is extremely efficient at eliminating carbon dioxide and raising pH in the newborn infant with acute respiratory failure. Improvement in oxygenation requires a strategy of sustained or repetitive inflations to 25 to 30 cm H2O in order to place the lung on the deflation limb of the pressure-volume curve. This strategy has also been shown to decrease the amount of secondary lung injury in animal models. Experience of the use of HFO ventilation as a rescue therapy as well as several published controlled trials have shown improved outcomes and a decrease in the use of extracorporeal membrane oxygenation when it has been used in newborns.

  14. High frequency nanotube oscillator

    Science.gov (United States)

    Peng, Haibing [Houston, TX; Zettl, Alexander K [Kensington, TX

    2012-02-21

    A tunable nanostructure such as a nanotube is used to make an electromechanical oscillator. The mechanically oscillating nanotube can be provided with inertial clamps in the form of metal beads. The metal beads serve to clamp the nanotube so that the fundamental resonance frequency is in the microwave range, i.e., greater than at least 1 GHz, and up to 4 GHz and beyond. An electric current can be run through the nanotube to cause the metal beads to move along the nanotube and changing the length of the intervening nanotube segments. The oscillator can operate at ambient temperature and in air without significant loss of resonance quality. The nanotube is can be fabricated in a semiconductor style process and the device can be provided with source, drain, and gate electrodes, which may be connected to appropriate circuitry for driving and measuring the oscillation. Novel driving and measuring circuits are also disclosed.

  15. Instantaneous Frequency Attribute Comparison

    Science.gov (United States)

    Yedlin, M. J.; Margrave, G. F.; Ben Horin, Y.

    2013-12-01

    The instantaneous seismic data attribute provides a different means of seismic interpretation, for all types of seismic data. It first came to the fore in exploration seismology in the classic paper of Taner et al (1979), entitled " Complex seismic trace analysis". Subsequently a vast literature has been accumulated on the subject, which has been given an excellent review by Barnes (1992). In this research we will compare two different methods of computation of the instantaneous frequency. The first method is based on the original idea of Taner et al (1979) and utilizes the derivative of the instantaneous phase of the analytic signal. The second method is based on the computation of the power centroid of the time-frequency spectrum, obtained using either the Gabor Transform as computed by Margrave et al (2011) or the Stockwell Transform as described by Stockwell et al (1996). We will apply both methods to exploration seismic data and the DPRK events recorded in 2006 and 2013. In applying the classical analytic signal technique, which is known to be unstable, due to the division of the square of the envelope, we will incorporate the stabilization and smoothing method proposed in the two paper of Fomel (2007). This method employs linear inverse theory regularization coupled with the application of an appropriate data smoother. The centroid method application is straightforward and is based on the very complete theoretical analysis provided in elegant fashion by Cohen (1995). While the results of the two methods are very similar, noticeable differences are seen at the data edges. This is most likely due to the edge effects of the smoothing operator in the Fomel method, which is more computationally intensive, when an optimal search of the regularization parameter is done. An advantage of the centroid method is the intrinsic smoothing of the data, which is inherent in the sliding window application used in all Short-Time Fourier Transform methods. The Fomel technique

  16. Robust power system frequency control

    CERN Document Server

    Bevrani, Hassan

    2014-01-01

    This updated edition of the industry standard reference on power system frequency control provides practical, systematic and flexible algorithms for regulating load frequency, offering new solutions to the technical challenges introduced by the escalating role of distributed generation and renewable energy sources in smart electric grids. The author emphasizes the physical constraints and practical engineering issues related to frequency in a deregulated environment, while fostering a conceptual understanding of frequency regulation and robust control techniques. The resulting control strategi

  17. Frequency mixer having ferromagnetic film

    Energy Technology Data Exchange (ETDEWEB)

    Khitun, Alexander; Roshchin, Igor V.; Galatsis, Kosmas; Bao, Mingqiang; Wang, Kang L.

    2016-03-29

    A frequency conversion device, which may include a radiofrequency (RF) mixer device, includes a substrate and a ferromagnetic film disposed over a surface of the substrate. An insulator is disposed over the ferromagnetic film and at least one microstrip antenna is disposed over the insulator. The ferromagnetic film provides a non-linear response to the frequency conversion device. The frequency conversion device may be used for signal mixing and amplification. The frequency conversion device may also be used in data encryption applications.

  18. Advanced Communication Technology Satellite (ACTS) multibeam antenna technology verification experiments

    Science.gov (United States)

    Acosta, Roberto J.; Larko, Jeffrey M.; Lagin, Alan R.

    1992-01-01

    The Advanced Communication Technology Satellite (ACTS) is a key to reaching NASA's goal of developing high-risk, advanced communications technology using multiple frequency bands to support the nation's future communication needs. Using the multiple, dynamic hopping spot beams, and advanced on board switching and processing systems, ACTS will open a new era in communications satellite technology. One of the key technologies to be validated as part of the ACTS program is the multibeam antenna with rapidly reconfigurable hopping and fixed spot beam to serve users equipped with small-aperature terminals within the coverage areas. The proposed antenna technology experiments are designed to evaluate in-orbit ACTS multibeam antenna performance (radiation pattern, gain, cross pol levels, etc.).

  19. High-current, high-frequency capacitors

    Science.gov (United States)

    Renz, D. D.

    1983-06-01

    The NASA Lewis high-current, high-frequency capacitor development program was conducted under a contract with Maxwell Laboratories, Inc., San Diego, California. The program was started to develop power components for space power systems. One of the components lacking was a high-power, high-frequency capacitor. Some of the technology developed in this program may be directly usable in an all-electric airplane. The materials used in the capacitor included the following: the film is polypropylene, the impregnant is monoisopropyl biphenyl, the conductive epoxy is Emerson and Cuming Stycast 2850 KT, the foil is aluminum, the case is stainless steel (304), and the electrode is a modified copper-ceramic.

  20. Parametric nanomechanical amplification at very high frequency.

    Science.gov (United States)

    Karabalin, R B; Feng, X L; Roukes, M L

    2009-09-01

    Parametric resonance and amplification are important in both fundamental physics and technological applications. Here we report very high frequency (VHF) parametric resonators and mechanical-domain amplifiers based on nanoelectromechanical systems (NEMS). Compound mechanical nanostructures patterned by multilayer, top-down nanofabrication are read out by a novel scheme that parametrically modulates longitudinal stress in doubly clamped beam NEMS resonators. Parametric pumping and signal amplification are demonstrated for VHF resonators up to approximately 130 MHz and provide useful enhancement of both resonance signal amplitude and quality factor. We find that Joule heating and reduced thermal conductance in these nanostructures ultimately impose an upper limit to device performance. We develop a theoretical model to account for both the parametric response and nonequilibrium thermal transport in these composite nanostructures. The results closely conform to our experimental observations, elucidate the frequency and threshold-voltage scaling in parametric VHF NEMS resonators and sensors, and establish the ultimate sensitivity limits of this approach.

  1. Phase noise and frequency stability in oscillators

    CERN Document Server

    Rubiola, Enrico

    2009-01-01

    Presenting a comprehensive account of oscillator phase noise and frequency stability, this practical text is both mathematically rigorous and accessible. An in-depth treatment of the noise mechanism is given, describing the oscillator as a physical system, and showing that simple general laws govern the stability of a large variety of oscillators differing in technology and frequency range. Inevitably, special attention is given to amplifiers, resonators, delay lines, feedback, and flicker (1/f) noise. The reverse engineering of oscillators based on phase-noise spectra is also covered, and end-of-chapter exercises are given. Uniquely, numerous practical examples are presented, including case studies taken from laboratory prototypes and commercial oscillators, which allow the oscillator internal design to be understood by analyzing its phase-noise spectrum. Based on tutorials given by the author at the Jet Propulsion Laboratory, international IEEE meetings, and in industry, this is a useful reference for acade...

  2. Ultra-Wideband Radio Frequency Identification Systems

    CERN Document Server

    Nekoogar, Faranak

    2012-01-01

    Ultra-Wideband Radio Frequency Identification Systems describes the essentials of radio frequency identification systems as well as their target markets. The authors provide a study of commercially available RFID systems and characterizes their performance in terms of read range and reliability in the presence of conductive and dielectric materials. The capabilities and limitations of some commercial RFID systems are reported followed by comprehensive discussions of the advantages and challenges of using ultra-wideband technology for tag/reader communications. The book presents practical aspects of UWB RFID system such as: pulse generation, remote powering, tag and reader antenna design, as well as special applications of  UWB RFIDs in a simple and easy-to-understand language.

  3. Graphene radio frequency receiver integrated circuit.

    Science.gov (United States)

    Han, Shu-Jen; Garcia, Alberto Valdes; Oida, Satoshi; Jenkins, Keith A; Haensch, Wilfried

    2014-01-01

    Graphene has attracted much interest as a future channel material in radio frequency electronics because of its superior electrical properties. Fabrication of a graphene integrated circuit without significantly degrading transistor performance has proven to be challenging, posing one of the major bottlenecks to compete with existing technologies. Here we present a fabrication method fully preserving graphene transistor quality, demonstrated with the implementation of a high-performance three-stage graphene integrated circuit. The circuit operates as a radio frequency receiver performing signal amplification, filtering and downconversion mixing. All circuit components are integrated into 0.6 mm(2) area and fabricated on 200 mm silicon wafers, showing the unprecedented graphene circuit complexity and silicon complementary metal-oxide-semiconductor process compatibility. The demonstrated circuit performance allow us to use graphene integrated circuit to perform practical wireless communication functions, receiving and restoring digital text transmitted on a 4.3-GHz carrier signal.

  4. Thermally activated technologies: Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2003-05-01

    The purpose of this Technology Roadmap is to outline a set of actions for government and industry to develop thermally activated technologies for converting America’s wasted heat resources into a reservoir of pollution-free energy for electric power, heating, cooling, refrigeration, and humidity control. Fuel flexibility is important. The actions also cover thermally activated technologies that use fossil fuels, biomass, and ultimately hydrogen, along with waste heat.

  5. Thermally activated technologies: Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2003-05-01

    The purpose of this Technology Roadmap is to outline a set of actions for government and industry to develop thermally activated technologies for converting America’s wasted heat resources into a reservoir of pollution-free energy for electric power, heating, cooling, refrigeration, and humidity control. Fuel flexibility is important. The actions also cover thermally activated technologies that use fossil fuels, biomass, and ultimately hydrogen, along with waste heat.

  6. Plastics Technology.

    Science.gov (United States)

    Barker, Tommy G.

    This curriculum guide is designed to assist junior high schools industrial arts teachers in planning new courses and revising existing courses in plastics technology. Addressed in the individual units of the guide are the following topics: introduction to production technology; history and development of plastics; safety; youth leadership,…

  7. Lasers technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The Lasers Technology Program of IPEN is committed to the development of new lasers based on the research of optical materials and new technologies, as well to laser applications in several areas: Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. The Program is basically divided into two main areas: Material and Laser Development and Laser Applications.

  8. Maritime Technology

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1997-01-01

    Elementary introduction to the subject "Maritime Technology".The contents include drawings, sketches and references in English without any supplementary text.......Elementary introduction to the subject "Maritime Technology".The contents include drawings, sketches and references in English without any supplementary text....

  9. Maritime Technology

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1997-01-01

    Elementary introduction to the subject "Maritime Technology".The contents include drawings, sketches and references in English without any supplementary text.......Elementary introduction to the subject "Maritime Technology".The contents include drawings, sketches and references in English without any supplementary text....

  10. Technology Push

    Science.gov (United States)

    Kennedy, Mike

    2008-01-01

    When students, teachers, administrators and others employed in education arrive at work every day on thousands of campuses across the nation, it should come as no surprise that at every step along the way, technology is there to greet them. Technological advancements in education, as well as in facilities operation and management, are not a…

  11. Robust power system frequency control

    CERN Document Server

    Bevrani, Hassan

    2008-01-01

    Emphasizes the physical and engineering aspects of the power system frequency control design problem while providing a conceptual understanding of frequency regulation and application of robust control techniques. This book summarizes the author's research outcomes, contributions and experiences with power system frequency regulation.

  12. Sensemaking technology

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    Research objective: The object of the LOK research project is to gain a better understanding of the technological strategic processes in organisations by using the concept/metaphor of sensemaking. The project will investigate the technological strategies in organisations in order to gain a deeper...... understanding of the cognitive competencies and barriers towards implementing new technology in organisations. The research will therefore concentrate on researching the development process in the organisation's perception of the external environmental elements of customers, suppliers, competitors, internal...... and external technology and legislation and the internal environmental elements of structure, power relations and political arenas. All of these variables have influence on which/how technologies are implemented thus creating different outcomes all depending on the social dynamics that are triggered by changes...

  13. Sensemaking technology

    DEFF Research Database (Denmark)

    Madsen, Charlotte Øland

    Research objective: The object of the LOK research project is to gain a better understanding of the technological strategic processes in organisations by using the concept/metaphor of sensemaking. The project will investigate the technological strategies in organisations in order to gain a deeper...... understanding of the cognitive competencies and barriers towards implementing new technology in organisations. The research will therefore concentrate on researching the development process in the organisation's perception of the external environmental elements of customers, suppliers, competitors, internal...... and external technology and legislation and the internal environmental elements of structure, power relations and political arenas. All of these variables have influence on which/how technologies are implemented thus creating different outcomes all depending on the social dynamics that are triggered by changes...

  14. Technology collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Jacob [Halliburton (Brazil)

    2011-07-01

    The aim of this paper is to present Halliburton's Brazilian technology center. Halliburton has technology centers in the United States, Saudi Arabia, India, Singapore and Brazil, all of which aim at delivering accelerated innovation in the oil sector. The technology centers engage in research and development activities with the help of various universities and in collaboration with the customer or supplier. The Halliburton Brazil technology center provides its customers with timely research and development solutions for enhancing recovery and mitigating reservoir uncertainty; they are specialized in finding solutions for pre- and post-salt carbonate drilling and in the enhancement of production from mature fields. This presentation showcased the work carried out by the Halliburton Brazil technology center to help customers develop their deepwater field activities.

  15. Frequency-agile antennas for wireless communications

    CERN Document Server

    Petosa, Aldo

    2013-01-01

    Mobile data subscriptions are expected to more than double and mobile wireless traffic to increase by more than tenfold over the next few years. Proliferation of smart phones, tablets, and other portable devices are placing greater demands for services such as web browsing, global positioning, video streaming, and video telephony. Many of the proposed solutions to deal with these demands will have a significant impact on antenna designs. Antennas with frequency agility are considered a promising technology to help implement these new solutions.This book provides readers with a sense of the cap

  16. Demand as Frequency-controlled Reserve

    DEFF Research Database (Denmark)

    Bang, Christian; Rasmussen, Christian Brandt; Østergaard, Jacob

    with great enthusiasm from all DFR project members who have shown a memorable dedication to their work. Active control of electricity demand is a key technology when creating a more dynamic, wind power friendly energy system. In this demonstration project, we have developed and tested devices, which use...... electric loads to provide frequency controlled primary reserves. The devices collected data from domestic households and industrial loads covering i.e. circulation pumps, electrical domestic heating, bottle coolers, a wastewater treatment plant etc., that have been analysed and used for the papers...

  17. Cultures of High-frequency Trading

    DEFF Research Database (Denmark)

    Lange, Ann-Christina; Lenglet, Marc; Seyfert, Robert

    2016-01-01

    As part of ongoing work to lay a foundation for social studies of high-frequency trading (HFT), this paper introduces the culture(s) of HFT as a sociological problem relating to knowledge and practice. HFT is often discussed as a purely technological development, where all that matters is the speed...... of allocating, processing and transmitting data. Indeed, the speed at which trades are executed and data transmitted is accelerating, and it is fair to say that algorithms are now the primary interacting agents operating in the financial markets. However, we contend that HFT is first and foremost a cultural...

  18. Meteor forward scattering at multiple frequencies

    Science.gov (United States)

    Nedeljkovic, Sasa

    2006-08-01

    Meteor forward scattering is a well known method of detecting meteors using a radio telescope to receive signals from distant transmitters scattered from a meteor trail. The traditional way of performing the meteor forward scattering is to tune the receiver to some particular frequency to match a distant transmitter and wait for reflected signals. In this paper I will show how new technologies can be used to make a simpler digital radio telescope capable of analyzing broadband spectra from 0 to 250 MHz. Such spectra contain information about several reflections on a single meteor, which can be enough to calculate the meteor's kinetic parameters.

  19. Vertical Nanowire High-Frequency Transistors

    OpenAIRE

    Johansson, Sofia

    2014-01-01

    This thesis explores a novel transistor technology based on vertical InAs nanowires, which could be considered both for low-power high-frequency analog applications and for replacing Si CMOS in the continued scaling of digital electronics. The potential of this device - the vertical InAs nanowire MOSFET – lies in the combination of the outstanding transport properties of InAs and the improved electrostatic control of the gate-all-around geometry. Three generations of the vertical InAs nanowir...

  20. Vertical Nanowire High-Frequency Transistors

    OpenAIRE

    Johansson, Sofia

    2014-01-01

    This thesis explores a novel transistor technology based on vertical InAs nanowires, which could be considered both for low-power high-frequency analog applications and for replacing Si CMOS in the continued scaling of digital electronics. The potential of this device - the vertical InAs nanowire MOSFET – lies in the combination of the outstanding transport properties of InAs and the improved electrostatic control of the gate-all-around geometry. Three generations of the vertical InAs nano...

  1. Minimization of nanosatellite low frequency magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Belyayev, S. M., E-mail: belyayev@isr.lviv.ua [Lviv Centre of Institute for Space Research, Lviv 79060 (Ukraine); Royal Institute of Technology, Stockholm 11428 (Sweden); Dudkin, F. L. [Lviv Centre of Institute for Space Research, Lviv 79060 (Ukraine)

    2016-03-15

    Small weight and dimensions of the micro- and nanosatellites constrain researchers to place electromagnetic sensors on short booms or on the satellite body. Therefore the electromagnetic cleanliness of such satellites becomes a central question. This paper describes the theoretical base and practical techniques for determining the parameters of DC and very low frequency magnetic interference sources. One of such sources is satellite magnetization, the reduction of which improves the accuracy and stability of the attitude control system. We present design solutions for magnetically clean spacecraft, testing equipment, and technology for magnetic moment measurements, which are more convenient, efficient, and accurate than the conventional ones.

  2. Relations between the technological standards and technological appropriation

    Directory of Open Access Journals (Sweden)

    Carlos Alberto PRADO GUERRERO

    2010-06-01

    Full Text Available The objective of this study is to analyze the educational practices of using Blackboard in blended learning environments with students of higher education to understand the relationship between technological appropriation and standards of educational technology. To achieve that goal, the following research question was raised: ¿To what extent are the standards of education technology with the appropriation of technology in blended learning environments in higher educa­tion related? The contextual framework of this work includes the following topics: the institution, teaching, teachers and students. The design methodology that was used is of a correlation type. Correlations were carried out to determine the frequency and level in the technological standards as well as the appropriation of technology. In the comparison of the results obtained by the students, the teachers and the platform; we found that students in the school study showed a high degree of technology ownership and this was the same for the performance shown on the technological standards. It was established that teachers play a key role in developing the techno­logical appropriation of students and performance in technology standards.

  3. Radio frequency heating for in-situ remediation of DNAPL

    Energy Technology Data Exchange (ETDEWEB)

    Kasevich, R.S. [KAI Technologies, Woburn, MA (United States)

    1996-08-01

    In-situ radio frequency (RF) heating technology for treating soils contaminated with dense nonaqueous phase liquids (DNAPLs) is described. RF imparts heat to non-conducting materials through the application of carefully controlled RF transmissions, improving contaminant flow characteristics and facilitating separation and removal from subsurface soils. The paper outlines advantages and limitations of RF remediation, process operations, general technology considerations, low permeability media considerations, commercial availability, and costs. Two case histories of RF remediation are briefly summarized. 13 refs., 10 figs.

  4. On the Ongoing Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, describes......The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...

  5. Improvement on Frequency Performance of SOI SiGe HBT

    Institute of Scientific and Technical Information of China (English)

    DAI Guang-hao; WANG Sheng-rong; LI Wen-jie

    2006-01-01

    Based on the advantages of SOI technology,the frequency performance of SiGe HBT with SOI structure has been simulated. Compared with bulk SiGe HBT,the results show that the buried oxide layer(BOX) can reduce collector-base capacitance CCB with the maximum value 89.3%,substrate-base capacitance CSB with 94.6%,and the maximum oscillation frequency is improved by 2.7. The SOI structure improves the frequency performance of SiGe HBT,which is adaptable to high-speed and high power applications.

  6. Ergonomics technology

    Science.gov (United States)

    Jones, W. L.

    1977-01-01

    Major areas of research and development in ergonomics technology for space environments are discussed. Attention is given to possible applications of the technology developed by NASA in industrial settings. A group of mass spectrometers for gas analysis capable of fully automatic operation has been developed for atmosphere control on spacecraft; a version for industrial use has been constructed. Advances have been made in personal cooling technology, remote monitoring of medical information, and aerosol particle control. Experience gained by NASA during the design and development of portable life support units has recently been applied to improve breathing equipment used by fire fighters.

  7. Alternative Approaches for Incentivizing the Frequency Responsive Reserve Ancillary Service

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E.; Milligan, M.; Kirby, B.; Tuohy, A.; Brooks, D.

    2012-03-01

    Frequency responsive reserve is the autonomous response of generators and demand response to deviations of system frequency, usually as a result of the instantaneous outage of a large supplier. Frequency responsive reserve arrests the frequency decline resulting in the stabilization of system frequency, and avoids the triggering of under-frequency load-shedding or the reaching of unstable frequencies that could ultimately lead to system blackouts. It is a crucial service required to maintain a reliable and secure power system. Regions with restructured electricity markets have historically had a lack of incentives for frequency responsive reserve because generators inherently provided the response and on large interconnected systems, more than sufficient response has been available. This may not be the case in future systems due to new technologies and declining response. This paper discusses the issues that can occur without proper incentives and even disincentives, and proposes alternatives to introduce incentives for resources to provide frequency responsive reserve to ensure an efficient and reliable power system.

  8. Accelerator Technology Division annual report, FY 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

    This paper discusses: accelerator physics and special projects; experiments and injectors; magnetic optics and beam diagnostics; accelerator design and engineering; radio-frequency technology; accelerator theory and simulation; free-electron laser technology; accelerator controls and automation; and high power microwave sources and effects.

  9. Buildings for advanced technology

    CERN Document Server

    Teague, E; Murday, James

    2015-01-01

    This book deals with the design and construction of buildings for nanoscale science and engineering research. The information provided in this book is useful for designing and constructing buildings for such advanced technologies as nanotechnology, nanoelectronics and biotechnology. The book outlines the technology challenges unique to each of the building environmental challenges outlined below and provides best practices and examples of engineering approaches to address them: • Establishing and maintaining critical environments: temperature, humidity, and pressure • Structural vibration isolation • Airborne vibration isolation (acoustic noise) • Isolation of mechanical equipment-generated vibration/acoustic noise • Cost-effective power conditioning • Grounding facilities for low electrical interference • Electromagnetic interference (EMI)/Radio frequency interference (RFI) isolation • Airborne particulate contamination • Airborne organic and chemical contamination • Environment, safety a...

  10. Research of Frequency Discriminator on Frequency Lock Loops

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Frequency lock loops (FLL) discriminating algorithms for direct-sequence spread-spectrum are discussed. The existing algorithms can't solve the problem of data bit reversal during one pre-detection integral period. And when the initial frequency offset is large, the frequency discriminator can't work normally. To solve these problems, a new FLL discriminating algorithm is introduced. The least-squares discriminator is used in this new algorithm. As the least-squares discriminator has a short process unit period, the corresponding frequency discriminating range is large. And the data bit reversal just influence one process unit period, so the least-squares discriminated result will not be affected. Compared with traditional frequency discriminator, the least-squares algorithm can effectively solve the problem of data bit reversal and can endure larger initial frequency offset.

  11. High spectral purity Kerr frequency comb radio frequency photonic oscillator.

    Science.gov (United States)

    Liang, W; Eliyahu, D; Ilchenko, V S; Savchenkov, A A; Matsko, A B; Seidel, D; Maleki, L

    2015-08-11

    Femtosecond laser-based generation of radio frequency signals has produced astonishing improvements in achievable spectral purity, one of the basic features characterizing the performance of an radio frequency oscillator. Kerr frequency combs hold promise for transforming these lab-scale oscillators to chip-scale level. In this work we demonstrate a miniature 10 GHz radio frequency photonic oscillator characterized with phase noise better than -60 dBc Hz(-1) at 10 Hz, -90 dBc Hz(-1) at 100 Hz and -170 dBc Hz(-1) at 10 MHz. The frequency stability of this device, as represented by Allan deviation measurements, is at the level of 10(-10) at 1-100 s integration time-orders of magnitude better than existing radio frequency photonic devices of similar size, weight and power consumption.

  12. Technology Innovation

    Science.gov (United States)

    EPA produces innovative technologies and facilitates their creation in line with the Agency mission to create products such as the stormwater calculator, remote sensing, innovation clusters, and low-cost air sensors.

  13. Banana technology

    Science.gov (United States)

    van Amstel, Willem D.; Schellekens, E. P. A.; Walravens, C.; Wijlaars, A. P. F.

    1999-09-01

    With 'Banana Technology' an unconventional hybrid fabrication technology is indicated for the production of very large parabolic and hyperbolic cylindrical mirror systems. The banana technology uses elastic bending of very large and thin glass substrates and fixation onto NC milled metal moulds. This technology has matured during the last twenty years for the manufacturing of large telecentric flat-bed scanners. Two construction types, called 'internal banana' and 'external banana; are presented. Optical figure quality requirements in terms of slope and curvature deviations are discussed. Measurements of these optical specifications by means of a 'finishing rod' type of scanning deflectometer or slope tester are presented. Design constraints for bending glass and the advantages of a new process will be discussed.

  14. Exploration technology

    Energy Technology Data Exchange (ETDEWEB)

    Roennevik, H.C. [Saga Petroleum A/S, Forus (Norway)

    1996-12-31

    The paper evaluates exploration technology. Topics discussed are: Visions; the subsurface challenge; the creative tension; the exploration process; seismic; geology; organic geochemistry; seismic resolution; integration; drilling; value creation. 4 refs., 22 figs.

  15. UPLIFTING TECHNOLOGY

    National Research Council Canada - National Science Library

    Thomas K Grose

    2015-01-01

      Inspired by Star Trek turbolifts, German engineering firm ThyssenKrupp says it's ready to replace cables and pulleys using maglev, or magnetic levitation technology, that enables the world's fastest...

  16. Videodisc technology

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, F.E. Jr.

    1981-03-01

    An overview of the technology of videodiscs is given. The emphasis is on systems that use reflection or transmission of laser light. Possible use of videodiscs for storage of bibliographic information is considered. 6 figures, 3 tables. (RWR)

  17. USING OF RFID TECHNOLOGY IN MAINTENANCE MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Michal Balog

    2015-06-01

    Full Text Available Automated data collection helps to improve the precision of decision-making processes. Currently, the radio frequency identification technology belongs to the most common application in the field of identification technology. In the world, the implementation of RFID technology is used in almost all areas of industry. RFID tags allow to use of the different products and materials applications. The article provides an overview of using this technology to record and register maintenance intervals of railway wagons. The application of RFID technology helps to avoid huge disasters and accidents caused by lack of information about the technical state of rail freight wagons.

  18. Resonance frequency in ferromagnetic superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Rongke; Huang Andong [School of Science, Shenyang University of Technology, Shenyang 110870 (China); Li Da; Zhang Zhidong, E-mail: rkqiu@163.com [Shenyang National Laboratory for Materials Science, Institute of Metal Research and International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016 (China)

    2011-10-19

    The resonance frequency in two-layer and three-layer ferromagnetic superlattices is studied, using the Callen's Green function method, the Tyablikov decoupling approximation and the Anderson-Callen decoupling approximation. The effects of interlayer exchange coupling, anisotropy, external magnetic field and temperature on the resonance frequency are investigated. It is found that the resonance frequencies increase with increasing external magnetic field. In a parameter region of the asymmetric system, each sublayer corresponds to its own resonance frequency. The anisotropy of a sublayer affects only the resonance frequency corresponding to this sublayer. The stronger the anisotropy, the higher is the resonance frequency. The interlayer exchange coupling affects only the resonance frequencies belonging to the sublayers connected by it. The stronger the interlayer exchange coupling, the higher are the resonance frequencies. All the resonance frequencies decrease as the reduced temperature increases. The results direct the method to enhance and adjust the resonance frequency of magnetic multilayered materials with a wide band.

  19. Digital frequency control of satellite frequency standards. [Defense Navigation Satellites

    Science.gov (United States)

    Nichols, S. A.

    1973-01-01

    In the Frequency and Time Standard Development Program of the TIMATION System, a new miniaturized rubidium vapor frequency standard has been tested and analyzed for possible use on the TIMATION 3A launch, as part of the Defense Navigation Satellite Development Program. The design and construction of a digital frequency control was required to remotely control this rubidium vapor frequency standard as well as the quartz oscillator in current use. This control must be capable of accepting commands from a satellite telemetry system, verify that the correct commands have been sent and control the frequency to the requirements of the system. Several modifications must be performed to the rubidium vapor frequency standard to allow it to be compatible with the digital frequency control. These include the addition of a varactor to voltage tune the coarse range of the flywheel oscillator, and a modification to supply the C field current externally. The digital frequency control for the rubidium vapor frequency standard has been successfully tested in prototype form.

  20. Fabrication Technology

    Energy Technology Data Exchange (ETDEWEB)

    Blaedel, K.L.

    1993-03-01

    The mission of the Fabrication Technology thrust area is to have an adequate base of manufacturing technology, not necessarily resident at Lawrence Livermore National Laboratory (LLNL), to conduct the future business of LLNL. The specific goals continue to be to (1) develop an understanding of fundamental fabrication processes; (2) construct general purpose process models that will have wide applicability; (3) document findings and models in journals; (4) transfer technology to LLNL programs, industry, and colleagues; and (5) develop continuing relationships with the industrial and academic communities to advance the collective understanding of fabrication processes. The strategy to ensure success is changing. For technologies in which they are expert and which will continue to be of future importance to LLNL, they can often attract outside resources both to maintain their expertise by applying it to a specific problem and to help fund further development. A popular vehicle to fund such work is the Cooperative Research and Development Agreement with industry. For technologies needing development because of their future critical importance and in which they are not expert, they use internal funding sources. These latter are the topics of the thrust area. Three FY-92 funded projects are discussed in this section. Each project clearly moves the Fabrication Technology thrust area towards the goals outlined above. They have also continued their membership in the North Carolina State University Precision Engineering Center, a multidisciplinary research and graduate program established to provide the new technologies needed by high-technology institutions in the US. As members, they have access to and use of the results of their research projects, many of which parallel the precision engineering efforts at LLNL.

  1. Cognitive technologies

    CERN Document Server

    Mello, Alan; Figueiredo, Fabrício; Figueiredo, Rafael

    2017-01-01

    This book focuses on the next generation optical networks as well as mobile communication technologies. The reader will find chapters on Cognitive Optical Network, 5G Cognitive Wireless, LTE, Data Analysis and Natural Language Processing. It also presents a comprehensive view of the enhancements and requirements foreseen for Machine Type Communication. Moreover, some data analysis techniques and Brazilian Portuguese natural language processing technologies are also described here. .

  2. Lasers technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Laser Technology Program of IPEN is developed by the Center for Lasers and Applications (CLA) and is committed to the development of new lasers based on the research of new optical materials and new resonator technologies. Laser applications and research occur within several areas such as Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. Additional goals of the Program are human resource development and innovation, in association with Brazilian Universities and commercial partners.

  3. Fabrication Technology

    Energy Technology Data Exchange (ETDEWEB)

    Blaedel, K.L.

    1993-03-01

    The mission of the Fabrication Technology thrust area is to have an adequate base of manufacturing technology, not necessarily resident at Lawrence Livermore National Laboratory (LLNL), to conduct the future business of LLNL. The specific goals continue to be to (1) develop an understanding of fundamental fabrication processes; (2) construct general purpose process models that will have wide applicability; (3) document findings and models in journals; (4) transfer technology to LLNL programs, industry, and colleagues; and (5) develop continuing relationships with the industrial and academic communities to advance the collective understanding of fabrication processes. The strategy to ensure success is changing. For technologies in which they are expert and which will continue to be of future importance to LLNL, they can often attract outside resources both to maintain their expertise by applying it to a specific problem and to help fund further development. A popular vehicle to fund such work is the Cooperative Research and Development Agreement with industry. For technologies needing development because of their future critical importance and in which they are not expert, they use internal funding sources. These latter are the topics of the thrust area. Three FY-92 funded projects are discussed in this section. Each project clearly moves the Fabrication Technology thrust area towards the goals outlined above. They have also continued their membership in the North Carolina State University Precision Engineering Center, a multidisciplinary research and graduate program established to provide the new technologies needed by high-technology institutions in the US. As members, they have access to and use of the results of their research projects, many of which parallel the precision engineering efforts at LLNL.

  4. The development of inverter technology in Haier refrigerator%海尔冰箱变频技术的发展

    Institute of Scientific and Technical Information of China (English)

    海尔集团

    2005-01-01

    Frequency conversion technology will be development direction of air-condition and fridge in the future. In this paper,Charateristic of the frequency conversion fridge was discussed in detail and discussed effect of frequency compressor in the fridge.

  5. Technology and technology transfer: some basic issues

    OpenAIRE

    Shamsavari, Ali; Adikibi, Owen; Taha, Yasser

    2002-01-01

    This paper addresses various issues relating to technology and transfer of technology such as technology and society, technology and science, channels and models of technology transfer, the role of multinational companies in transfer of technology, etc. The ultimate objective is to pose the question of relevance of some existing models and ideas like technological independence in an increasingly globalised world economy.

  6. Radio Frequency Identification (RFID) in healthcare: a literature review.

    Science.gov (United States)

    Kolokathi, Aikaterini; Rallis, Panagiotis

    2013-01-01

    Creating and maintaining a safe and high-quality health care environment is of great importance for global community. New technologies and their applications can help us achieve this goal. Radio-Frequency Identification (RIFD) technology is considered one of those technologies and even today there are some interesting deployments in the health industry. As a result, this work aims to present the basic idea behind RFID solutions, problems that can be addressed with the adoption of RFID and the benefits of relative applications.

  7. Counting Frequencies from Zotero Items

    Directory of Open Access Journals (Sweden)

    Spencer Roberts

    2013-04-01

    Full Text Available In Counting Frequencies you learned how to count the frequency of specific words in a list using python. In this lesson, we will expand on that topic by showing you how to get information from Zotero HTML items, save the content from those items, and count the frequencies of words. It may be beneficial to look over the previous lesson before we begin.

  8. Counting Word Frequencies with Python

    Directory of Open Access Journals (Sweden)

    William J. Turkel

    2012-07-01

    Full Text Available Your list is now clean enough that you can begin analyzing its contents in meaningful ways. Counting the frequency of specific words in the list can provide illustrative data. Python has an easy way to count frequencies, but it requires the use of a new type of variable: the dictionary. Before you begin working with a dictionary, consider the processes used to calculate frequencies in a list.

  9. Authentication of Radio Frequency Identification Devices Using Electronic Characteristics

    Science.gov (United States)

    Chinnappa Gounder Periaswamy, Senthilkumar

    2010-01-01

    Radio frequency identification (RFID) tags are low-cost devices that are used to uniquely identify the objects to which they are attached. Due to the low cost and size that is driving the technology, a tag has limited computational capabilities and resources. This limitation makes the implementation of conventional security protocols to prevent…

  10. Shoaling and shoreline dissipation of low‐frequency waves

    NARCIS (Netherlands)

    Van Dongeren, A.; Battjes, J.A.; Janssen, T.; Van Noorloos, J.; Steenhauer, K.; Steenbergen, G.; Reniers, A.

    2007-01-01

    The growth rate, shoreline reflection, and dissipation of low‐frequency waves are investigated using data obtained from physical experiments in the Delft University of Technology research flume and by parameter variation using the numerical model Delft3D‐SurfBeat. The growth rate of the shoaling inc

  11. SiGe Building Blocks for Microwave Frequency Synthesizers

    OpenAIRE

    Vaucher, Cicero S.; Apostolidou, M; Farrugia, Andrew; Praamsma, Louis

    2004-01-01

    Implementations of Ku- and Ka-band PLL building blocks in the Philips QUBiC4G SiGe technology are presented: a 10 GHz fully-integrated low-phase-noise differential Colpttis oscillator, a 25 GHz low-power adaptive prescaler, and a 18 GHz truly-modular fully-programmable frequency divider.

  12. Understanding Inertial and Frequency Response of Wind Power Plants: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, E.; Gevorgian, V.; Singh, M.; Santoso, S.

    2012-07-01

    The objective of this paper is to analyze and quantify the inertia and frequency responses of wind power plants with different wind turbine technologies (particularly those of fixed speed, variable slip with rotor-resistance controls, and variable speed with vector controls).

  13. Low-frequency switching voltage regulators for terrestrial photovoltaic systems

    Science.gov (United States)

    Delombard, R.

    1984-01-01

    The photovoltaic technology project and the stand alone applications project are discussed. Two types of low frequency switching type regulators were investigated. The design, operating characteristics and field application of these regulators is described. The regulators are small in size, low in cost, very low in power dissipation, reliable and allow considerable flexibility in system design.

  14. Frequency Resonance in Stochastic Systems

    Institute of Scientific and Technical Information of China (English)

    钱敏; 张雪娟

    2003-01-01

    The phenomenon of frequency resonance, which is usually related to deterministic systems, is investigated in stochastic systems. We show that for those autonomous systems driven only by white noise, if the output power spectrum exhibits a nonzero peak frequency, then applying a periodic signel just on this noise-induced central frequency can also induce a resonance phenomenon, which we call the frequency stochastic resonance. The effect of such a resonance in a coupled stochastic system is shown to be much better than that in a single-oscillator system.

  15. Mixed Frequency Ultrasound Phased Array

    Institute of Scientific and Technical Information of China (English)

    香勇; 霍健; 施克仁; 陈以方

    2004-01-01

    A mixed frequency ultrasonic phased array (MPA) was developed to improve the focus, in which the element excitation frequencies are not all the same as in a normal constant frequency phased array. A theoretical model of the mixed frequency phased array based on the interference principle was used to simulate the array's sound distribution. The pressure intensity in the array focal area was enhanced and the scanning area having effective contrast resolution was enlarged. The system is especially useful for high intensity focused ultrasound (HIFU) with more powerful energy and ultrasound imaging diagnostics with improved signal to noise ratios, improved beam forming and more uniform imaging quality.

  16. Radio Frequency Anechoic Chamber Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the design, manufacture, and test of antenna systems. The facility is also used as an electromagnetic compatibility/radio frequency interference...

  17. Lexical frequency and voice assimilation.

    Science.gov (United States)

    Ernestus, Mirjam; Lahey, Mybeth; Verhees, Femke; Baayen, R Harald

    2006-08-01

    Acoustic duration and degree of vowel reduction are known to correlate with a word's frequency of occurrence. The present study broadens the research on the role of frequency in speech production to voice assimilation. The test case was regressive voice assimilation in Dutch. Clusters from a corpus of read speech were more often perceived as unassimilated in lower-frequency words and as either completely voiced (regressive assimilation) or, unexpectedly, as completely voiceless (progressive assimilation) in higher-frequency words. Frequency did not predict the voice classifications over and above important acoustic cues to voicing, suggesting that the frequency effects on the classifications were carried exclusively by the acoustic signal. The duration of the cluster and the period of glottal vibration during the cluster decreased while the duration of the release noises increased with frequency. This indicates that speakers reduce articulatory effort for higher-frequency words, with some acoustic cues signaling more voicing and others less voicing. A higher frequency leads not only to acoustic reduction but also to more assimilation.

  18. 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

  19. Frequency hopping millimeter wave reflectometer

    Science.gov (United States)

    Cupido, L.; Sánchez, J.; Estrada, T.

    2004-10-01

    Reflectometry techniques are employed to study density fluctuations in fusion plasmas either using one channel or two channels with slightly different frequencies, to probe simultaneously closely spaced plasma layers (for radial correlation studies). The present article describes a novel system with increasing measuring capability utilizing only one single frequency that can be hopped during the discharge. This broadband fast hopping mm-wave reflectometer (BFHR) has been developed for both ASDEX upgrade (Max Plank Institute-Garching-Germany) and TJ-II stellarator (CIEMAT-Spain). The BFHR incorporates frequency synthesizers at microwave frequencies multiplied into the millimeter-wave range and uses heterodyne detection for sensitive phase and amplitude measurements.

  20. Automatic oscillator frequency control system

    Science.gov (United States)

    Smith, S. F. (Inventor)

    1985-01-01

    A frequency control system makes an initial correction of the frequency of its own timing circuit after comparison against a frequency of known accuracy and then sequentially checks and corrects the frequencies of several voltage controlled local oscillator circuits. The timing circuit initiates the machine cycles of a central processing unit which applies a frequency index to an input register in a modulo-sum frequency divider stage and enables a multiplexer to clock an accumulator register in the divider stage with a cyclical signal derived from the oscillator circuit being checked. Upon expiration of the interval, the processing unit compares the remainder held as the contents of the accumulator against a stored zero error constant and applies an appropriate correction word to a correction stage to shift the frequency of the oscillator being checked. A signal from the accumulator register may be used to drive a phase plane ROM and, with periodic shifts in the applied frequency index, to provide frequency shift keying of the resultant output signal. Interposition of a phase adder between the accumulator register and phase plane ROM permits phase shift keying of the output signal by periodic variation in the value of a phase index applied to one input of the phase adder.

  1. Numeracy, frequency, and Bayesian reasoning

    Directory of Open Access Journals (Sweden)

    Gretchen B. Chapman

    2009-02-01

    Full Text Available Previous research has demonstrated that Bayesian reasoning performance is improved if uncertainty information is presented as natural frequencies rather than single-event probabilities. A questionnaire study of 342 college students replicated this effect but also found that the performance-boosting benefits of the natural frequency presentation occurred primarily for participants who scored high in numeracy. This finding suggests that even comprehension and manipulation of natural frequencies requires a certain threshold of numeracy abilities, and that the beneficial effects of natural frequency presentation may not be as general as previously believed.

  2. A graphene based frequency quadrupler

    Science.gov (United States)

    Cheng, Chuantong; Huang, Beiju; Mao, Xurui; Zhang, Zanyun; Zhang, Zan; Geng, Zhaoxin; Xue, Ping; Chen, Hongda

    2017-04-01

    Benefit from exceptional electrical transport properties, graphene receives worldwide attentions, especially in the domain of high frequency electronics. Due to absence of effective bandgap causing off-state the device, graphene material is extraordinarily suitable for analog circuits rather than digital applications. With this unique ambipolar behavior, graphene can be exploited and utilized to achieve high performance for frequency multipliers. Here, dual-gated graphene field-effect transistors have been firstly used to achieve frequency quadrupling. Two Dirac points in the transfer curves of the designed GFETs can be observed by tuning top-gate voltages, which is essential to generate the fourth harmonic. By applying 200 kHz sinusoid input, arround 50% of the output signal radio frequency power is concentrated at the desired frequency of 800 kHz. Additionally, in suitable operation areas, our devices can work as high performance frequency doublers and frequency triplers. Considered both simple device structure and potential superhigh carrier mobility of graphene material, graphene-based frequency quadruplers may have lots of superiorities in regards to ultrahigh frequency electronic applications in near future. Moreover, versatility of carbon material system is far-reaching for realization of complementary metal-oxide-semiconductor compatible electrically active devices.

  3. Frequency dependent polarization analysis of high-frequency seismograms

    Science.gov (United States)

    Park, Jeffrey; Vernon, Frank L., III; Lindberg, Craig R.

    1987-11-01

    We present a multitaper algorithm to estimate the polarization of particle motion as a function of frequency from three-component seismic data. This algorithm is based on a singular value decomposition of a matrix of eigenspectra at a given frequency. The right complex eigenvector zˆ corresonding to the largest singular value of the matrix has the same direction as the dominant polarization of seismic motion at that frequency. The elements of the polarization vector zˆ specify the relative amplitudes and phases of motion measured along the recorded components within a chosen frequency band. The width of this frequency band is determined by the time-bandwidth product of the prolate spheroidal tapers used in the analysis. We manipulate the components of zˆ to determine the apparent azimuth and angle of incidence of seismic motion as a function of frequency. The orthogonality of the eigentapers allows one to calculate easily uncertainties in the estimated azimuth and angle of incidence. We apply this algorithm to data from the Anza Seismic Telemetered Array in the frequency band 0 ≤ ƒ ≤ 30 Hz. The polarization is not always a smooth function of frequency and can exhibit sharp jumps, suggesting the existence of scattered modes within the crustal waveguide and/or receiver site resonances.

  4. Absolute frequency measurement of unstable lasers with optical frequency combs

    Science.gov (United States)

    Beverini, N.; Poli, N.; Sutyrin, D.; Wang, F.-Y.; Schioppo, M.; Tarallo, M. G.; Tino, G. M.

    2010-09-01

    Here we report on absolute frequency measurements of a commercial high power CW diode-pumped solid-state laser (Coherent Verdi-V5). This kind of lasers usually presents large frequency jitter (up to 50 MHz) both in the short term (1 ms time scale) and in the long term (>10 s time scale). A precise measurement of absolute frequency deviations in both temporal scales should require a set of different devices (optical cavities, optical wave-meters), each suited for measurements only at a specific integration time. Here we demonstrate how a frequency comb can be used to overcome this difficulty, allowing in a single step a full characterization of both short ( 103 s) absolute frequency jitter with a resolution better than 1 MHz. We demonstrate in this way the flexibility of optical frequency combs for absolute frequency measurements not only of ultra-stable lasers but also of relatively unstable lasers. The absolute frequency calibration of the Verdi laser that we have obtained have been used in order to improve the accuracy of the measurements of the local gravitational acceleration value with 88Sr atoms trapped in 1D vertical lattices.

  5. Technology cycles and technology revolutions

    Energy Technology Data Exchange (ETDEWEB)

    Paganetto, Luigi; Scandizzo, Pasquale Lucio

    2010-09-15

    Technological cycles have been characterized as the basis of long and continuous periods economic growth through sustained changes in total factor productivity. While this hypothesis is in part consistent with several theories of growth, the sheer magnitude and length of the economic revolutions experienced by humankind seems to indicate surmise that more attention should be given to the origin of major technological and economic changes, with reference to one crucial question: role of production and use of energy in economic development.

  6. Integrated Arrays on Silicon at Terahertz Frequencies

    Science.gov (United States)

    Chattopadhayay, Goutam; Lee, Choonsup; Jung, Cecil; Lin, Robert; Peralta, Alessandro; Mehdi, Imran; Llombert, Nuria; Thomas, Bertrand

    2011-01-01

    In this paper we explore various receiver font-end and antenna architecture for use in integrated arrays at terahertz frequencies. Development of wafer-level integrated terahertz receiver front-end by using advanced semiconductor fabrication technologies and use of novel integrated antennas with silicon micromachining are reported. We report novel stacking of micromachined silicon wafers which allows for the 3-dimensional integration of various terahertz receiver components in extremely small packages which easily leads to the development of 2- dimensioanl multi-pixel receiver front-ends in the terahertz frequency range. We also report an integrated micro-lens antenna that goes with the silicon micro-machined front-end. The micro-lens antenna is fed by a waveguide that excites a silicon lens antenna through a leaky-wave or electromagnetic band gap (EBG) resonant cavity. We utilized advanced semiconductor nanofabrication techniques to design, fabricate, and demonstrate a super-compact, low-mass submillimeter-wave heterodyne frontend. When the micro-lens antenna is integrated with the receiver front-end we will be able to assemble integrated heterodyne array receivers for various applications such as multi-pixel high resolution spectrometer and imaging radar at terahertz frequencies.

  7. Behavioral estimates of human frequency selectivity at low frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado

    A fundamental property of our hearing organ is its ability to break down sound into different spectral components, allowing us to make use of the richness in natural sound phenomena. Auditory filters, which conceptualize this property of the ear, however, have not been appropriately described...... at low sound frequencies. As a consequence of our lack of knowledge, we cannot accurately model our perception of complex low-frequency sound (such as that emitted by wind turbines or industrial processes, which can easily produce annoyance) nor make meaningful predictions of our perception based...... on physical sound measurements. In this PhD thesis a detailed description of frequency selectivity at low frequencies is given. Different experiments have been performed to determine the properties of human auditory filters. Besides, loudness perception of low-frequency sinusoidal signals has been evaluated...

  8. Frequency stabilized lasers for space applications

    Science.gov (United States)

    Lieber, Mike; Adkins, Mike; Pierce, Robert; Warden, Robert; Wallace, Cynthia; Weimer, Carl

    2014-09-01

    metrology, spectroscopy, atomic clocks and geodesy. This technology will be a key enabler to several proposed NASA science missions. Although lasers such as Q-switched Nd-YAG are now commonly used in space, other types of lasers - especially those with narrow linewidth - are still few in number and more development is required to advance their technology readiness. In this paper we discuss a reconfigurable laser frequency stabilization testbed, and end-to-end modeling to support system development. Two important features enabling testbed flexibility are that the controller, signal processing and interfaces are hosted on a field programmable gate array (FPGA) which has spacequalified equivalent parts, and secondly, fiber optic relay of the beam paths. Given the nonlinear behavior of lasers, FPGA implementation is a key system reliability aspect allowing on-orbit retuning of the control system and initial frequency acquisition. The testbed features a dual sensor system, one based upon a high finesse resonator cavity which provides relative stability through Pound-Drever-Hall (PDH) modulation and secondly an absolute frequency reference by dither locking to an acetylene gas cell (GC). To provide for differences between ground and space implementation, we have developed an end-to-end Simulink/ Matlab®-based control system model of the testbed components including the important noise sources. This model is in the process of being correlated to the testbed data which then can be used for trade studies, and estimation of space-based performance and sensitivities. A 1530 nm wavelength semiconductor laser is used for this initial work.

  9. Low-Frequency-Noise Reduction Technique for Linear Analog CMOS IC's

    OpenAIRE

    Koh, Jeongwook

    2007-01-01

    For AMS (analog-mixed signal) and RF (radio frequency) implementations CMOS (Complementary Metal Oxide Semiconductor) technology platforms are the mainstream today. These platforms provide great density and power savings on digital parts on the same chip and, in addition, a good mix of components for analog design. The analog performance of CMOS technology is worse compared to other technology options (e.g. bipolar technology), and its major advantage is the lower total cost of system. Severa...

  10. Knowledge Technologies

    CERN Document Server

    Milton, Nick

    2008-01-01

    Several technologies are emerging that provide new ways to capture, store, present and use knowledge. This book is the first to provide a comprehensive introduction to five of the most important of these technologies: Knowledge Engineering, Knowledge Based Engineering, Knowledge Webs, Ontologies and Semantic Webs. For each of these, answers are given to a number of key questions (What is it? How does it operate? How is a system developed? What can it be used for? What tools are available? What are the main issues?). The book is aimed at students, researchers and practitioners interested in Knowledge Management, Artificial Intelligence, Design Engineering and Web Technologies. During the 1990s, Nick worked at the University of Nottingham on the application of AI techniques to knowledge management and on various knowledge acquisition projects to develop expert systems for military applications. In 1999, he joined Epistemics where he worked on numerous knowledge projects and helped establish knowledge management...

  11. Persuasive Technology

    DEFF Research Database (Denmark)

    This book constitutes the proceedings of the 5th International Conference on Persuasive Technology, PERSUASIVE 2010, held in Copenhagen Denmark in June 2010. The 25 papers presented were carefully reviewed and selected from 80 submissions. In addition three keynote papers are included in this vol......This book constitutes the proceedings of the 5th International Conference on Persuasive Technology, PERSUASIVE 2010, held in Copenhagen Denmark in June 2010. The 25 papers presented were carefully reviewed and selected from 80 submissions. In addition three keynote papers are included...... in this volume. The topics covered are emotions and user experience, ambient persuasive systems, persuasive design, persuasion profiles, designing for health, psychology of persuasion, embodied and conversational agents, economic incentives, and future directions for persuasive technology....

  12. Seafood Technology

    DEFF Research Database (Denmark)

    Børresen, Torger

    This presentation will fill the total picture of this conference between fisheries and aquaculture, blue biotech and bioconservation, by considering the optimal processing technology of marine resources from the raw material until the seafood reaches the plate of the consumer. The situation today...... must be performed such that total traceability and authenticity of the final products can be presented on demand. The most important aspects to be considered within seafood technology today are safety, healthy products and high eating quality. Safety can be divided into microbiological safety...... and not presenting any safety risk per se. Seafood is healthy due to the omega-3 fatty acids and the nutritional value of vitamins, peptides and proteins. The processing technology must however be performed such that these valuable features are not lost during production. The same applies to the eating quality. Any...

  13. Persuasive Technology

    DEFF Research Database (Denmark)

    This book constitutes the proceedings of the 5th International Conference on Persuasive Technology, PERSUASIVE 2010, held in Copenhagen Denmark in June 2010. The 25 papers presented were carefully reviewed and selected from 80 submissions. In addition three keynote papers are included in this vol......This book constitutes the proceedings of the 5th International Conference on Persuasive Technology, PERSUASIVE 2010, held in Copenhagen Denmark in June 2010. The 25 papers presented were carefully reviewed and selected from 80 submissions. In addition three keynote papers are included...... in this volume. The topics covered are emotions and user experience, ambient persuasive systems, persuasive design, persuasion profiles, designing for health, psychology of persuasion, embodied and conversational agents, economic incentives, and future directions for persuasive technology....

  14. Technology Transfer

    Science.gov (United States)

    Smith, Nanette R.

    1995-01-01

    The objective of this summer's work was to attempt to enhance Technology Application Group (TAG) ability to measure the outcomes of its efforts to transfer NASA technology. By reviewing existing literature, by explaining the economic principles involved in evaluating the economic impact of technology transfer, and by investigating the LaRC processes our William & Mary team has been able to lead this important discussion. In reviewing the existing literature, we identified many of the metrics that are currently being used in the area of technology transfer. Learning about the LaRC technology transfer processes and the metrics currently used to track the transfer process enabled us to compare other R&D facilities to LaRC. We discuss and diagram impacts of technology transfer in the short run and the long run. Significantly, it serves as the basis for analysis and provides guidance in thinking about what the measurement objectives ought to be. By focusing on the SBIR Program, valuable information regarding the strengths and weaknesses of this LaRC program are to be gained. A survey was developed to ask probing questions regarding SBIR contractors' experience with the program. Specifically we are interested in finding out whether the SBIR Program is accomplishing its mission, if the SBIR companies are providing the needed innovations specified by NASA and to what extent those innovations have led to commercial success. We also developed a survey to ask COTR's, who are NASA employees acting as technical advisors to the SBIR contractors, the same type of questions, evaluating the successes and problems with the SBIR Program as they see it. This survey was developed to be implemented interactively on computer. It is our hope that the statistical and econometric studies that can be done on the data collected from all of these sources will provide insight regarding the direction to take in developing systematic evaluations of programs like the SBIR Program so that they can

  15. Soulful Technologies

    DEFF Research Database (Denmark)

    Fausing, Bent

    2010-01-01

    Samsung introduced in 2008 a mobile phone called "Soul" made with a human touch and including itself a "magic touch". Through the analysis of a Nokia mobile phone TV-commercials I want to examine the function and form of digital technology in everyday images. The mobile phone and its digital came...... commercials and internet commercials for mobile phones from Nokia, or handheld computers, as Sony-Ericsson prefers to call them. Digital technology points towards a forgotten pre-human and not only post-human condition....

  16. Playful Technology

    DEFF Research Database (Denmark)

    Johansen, Stine Liv; Eriksson, Eva

    2013-01-01

    In this paper, the design of future services for children in Danish public libraries is discussed, in the light of new challenges and opportunities in relation to new media and technologies. The Danish government has over the last few years initiated and described a range of initiatives regarding...... in the library, the changing role of the librarians and the library space. We argue that intertwining traditional library services with new media forms and engaging play is the core challenge for future design in physical public libraries, but also that it is through new media and technology that new...

  17. Playful Technology

    DEFF Research Database (Denmark)

    Johansen, Stine Liv; Eriksson, Eva

    2013-01-01

    in the library, the changing role of the librarians and the library space. We argue that intertwining traditional library services with new media forms and engaging play is the core challenge for future design in physical public libraries, but also that it is through new media and technology that new......In this paper, the design of future services for children in Danish public libraries is discussed, in the light of new challenges and opportunities in relation to new media and technologies. The Danish government has over the last few years initiated and described a range of initiatives regarding...

  18. Architectural technology

    DEFF Research Database (Denmark)

    2005-01-01

    The booklet offers an overall introduction to the Institute of Architectural Technology and its projects and activities, and an invitation to the reader to contact the institute or the individual researcher for further information. The research, which takes place at the Institute of Architectural...... Technology at the Roayl Danish Academy of Fine Arts, School of Architecture, reflects a spread between strategic, goal-oriented pilot projects, commissioned by a ministry, a fund or a private company, and on the other hand projects which originate from strong personal interests and enthusiasm of individual...

  19. Low-frequency-noise complaints

    DEFF Research Database (Denmark)

    Pedersen, Christian Sejer; Møller, Henrik; Persson-Waye, Kerstin

    2008-01-01

    From 203 cases of low-frequency complaints a random selection of twenty-one cases were investigated. The main aim of the investigation was to answer the question whether the annoyance is caused by an external physical sound or by a physically non-existing sound, i.e. low-frequency tinnitus. Noise...... of the complainants are annoyed by a physical sound (20-180 Hz), while others suffer from low-frequency tinnitus (perceived frequency 40-100 Hz). Physical sound at frequencies below 20 Hz (infrasound) is not responsible for the annoyance - or at all audible - in any of the investigated cases, and none...... of the complainants has extraordinary hearing sensitivity at low frequencies. For comparable cases of low-frequency noise complaints in general, it is anticipated that physical sound is responsible in a substantial part of the cases, while low-frequency tinnitus is responsible in another substantial part of the cases....

  20. Gaming Frequency and Academic Performance

    Science.gov (United States)

    Ip, Barry; Jacobs, Gabriel; Watkins, Alan

    2008-01-01

    There are numerous claims that playing computer and video games may be educationally beneficial, but there has been little formal investigation into whether or not the frequency of exposure to such games actually affects academic performance. This paper explores the issue by analysing the relationships between gaming frequency--measured as the…

  1. Frequency Sensitivity in Nervous Systems

    Institute of Scientific and Technical Information of China (English)

    LIU Feng; WANG Wei

    2001-01-01

    We first demonstrate how to quantify the information conveyed in temporal firing patterns of neurons. We then show that neurons are more sensitive to signals with frequencies within the range of 20 - 70 Hz in weak signal detection. Such frequency sensitivity is characterized by both the output signal-to-noise ratio and the information measures.

  2. A variable frequency semiconductor laser

    Energy Technology Data Exchange (ETDEWEB)

    Tosikhiro, F.; Khiromoto, S.

    1984-03-27

    A variable frequency, power stabilized semiconductor laser is patented. This laser includes, in addition to an active layer, a photoconducting channel layer and a layer made from a material manifesting a Pockels effect. A voltage is injected between these two layers to vary the emission frequency. The laser pumping voltage is stabilized.

  3. Lexical Frequency in Sign Languages

    Science.gov (United States)

    Johnston, Trevor

    2012-01-01

    Measures of lexical frequency presuppose the existence of corpora, but true machine-readable corpora of sign languages (SLs) are only now being created. Lexical frequency ratings for SLs are needed because there has been a heavy reliance on the interpretation of results of psycholinguistic and neurolinguistic experiments in the SL research…

  4. Frequency-controlled voltage regulator

    Science.gov (United States)

    Mclyman, W. T.

    1980-01-01

    Converting input ac to higher frequency reduce size and weight and makes possible unique kind of regulation. Since conversion frequency is above range of human hearing, supply generated on audible noise. It also exploits highfrequency conversion features to regulate its output voltage in novel way. Circuit is inherently short-circuit proof.

  5. Microwave mixer technology and applications

    CERN Document Server

    Henderson, Bert

    2013-01-01

    Although microwave mixers play a critical role in wireless communication and other microwave applications employing frequency conversion circuits, engineers find that most books on this subject emphasize theoretical aspects, rather than practical applications. That's about to change with the forthcoming release of Microwave Mixer Technology and Applications. Based on a review of over one thousand patents on mixers and frequency conversion, authors Bert Henderson and Edmar Camargo have written a comprehensive book for mixer designers who want solid ideas for solving their own design challenges.

  6. Laser Spectroscopy and Frequency Combs

    Science.gov (United States)

    Hänsch, Theodor W.; Picqué, Nathalie

    2013-12-01

    The spectrum of a frequency comb, commonly generated by a mode-locked femtosecond laser consists of several hundred thousand precisely evenly spaced spectral lines. Such laser frequency combs have revolutionized the art measuring the frequency of light, and they provide the long-missing clockwork for optical atomic clocks. The invention of the frequency comb technique has been motivated by precision laser spectroscopy of the simple hydrogen atom. The availability of commercial instruments is facilitating the evolution of new applications far beyond the original purpose. Laser combs are becoming powerful instruments for broadband molecular spectroscopy by dramatically improving the resolution and recording speed of Fourier spectrometers and by creating new opportunities for highly multiplexed nonlinear spectroscopy, such as two-photon spectroscopy or coherent Raman spectroscopy. Other emerging applications of frequency combs range from fundamental research in astronomy, chemistry, or attosecond science to telecommunications and satellite navigation.

  7. Frequency conversion of structured light

    CERN Document Server

    Steinlechner, Fabian; Pruneri, Valerio; Torres, Juan P

    2015-01-01

    We demonstrate the coherent frequency conversion of structured light, optical beams in which the phase varies in each point of the transverse plane, from the near infrared (803nm) to the visible (527nm). The frequency conversion process makes use of sum-frequency generation in a periodically poled lithium niobate (ppLN) crystal with the help of a 1540-nm Gaussian pump beam. We perform far-field intensity measurements of the frequency-converted field, and verify the sought-after transformation of the characteristic intensity and phase profiles for various input modes. The coherence of the frequency-conversion process is confirmed using a mode-projection technique with a phase mask and a single-mode fiber. The presented results could be of great relevance to novel applications in high-resolution microscopy and quantum information processing.

  8. Swiss and Turkish Pre-Service Science Teachers' Anxiety Levels for Educational Technology

    Science.gov (United States)

    Efe, Hulya Aslan; Efe, Rifat

    2016-01-01

    This study aims to culturally explain pre-service science teachers' instructional technology-related anxiety levels by analyzing the variables of their instructional technology using experiences, frequency of using instructional technologies, access to instructional technologies, instructional technology-related attitude and their instructional…

  9. Manufacturing technologies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Manufacturing Technologies Center is an integral part of Sandia National Laboratories, a multiprogram engineering and science laboratory, operated for the Department of Energy (DOE) with major facilities at Albuquerque, New Mexico, and Livermore, California. Our Center is at the core of Sandia`s Advanced Manufacturing effort which spans the entire product realization process.

  10. Blast Technologies

    Science.gov (United States)

    2011-06-27

    Team Leader Risa Scherer Blast Mitigation Interior and Laboratory Team Leader Blast Technologies POC’s Government Point Of Contacts (POCs): To...to yield injury assessments at higher fidelities and with higher confidence UNCLASSIFIED UNCLASSIFIED Risa Scherer Blast Mitigation Interior and

  11. Energy Technology.

    Science.gov (United States)

    Eaton, William W.

    Reviewed are technological problems faced in energy production including locating, recovering, developing, storing, and distributing energy in clean, convenient, economical, and environmentally satisfactory manners. The energy resources of coal, oil, natural gas, hydroelectric power, nuclear energy, solar energy, geothermal energy, winds, tides,…

  12. Strategic Technology

    Science.gov (United States)

    2012-03-11

    the spectrum of future conflict and engagement. Technology Surprise Francis Fukuyama , in his introduction to the book Blindside, summarizes recent...atrocities or large-scale natural disasters abroad 12 Francis Fukuyama , ed, Blindside (Baltimore, MD: Brookings Institute Press, 2007), 1. 13 Defense

  13. (Environmental technology)

    Energy Technology Data Exchange (ETDEWEB)

    Boston, H.L.

    1990-10-12

    The traveler participated in a conference on environmental technology in Paris, sponsored by the US Embassy-Paris, US Environmental Protection Agency (EPA), the French Environmental Ministry, and others. The traveler sat on a panel for environmental aspects of energy technology and made a presentation on the potential contributions of Oak Ridge National Laboratory (ORNL) to a planned French-American Environmental Technologies Institute in Chattanooga, Tennessee, and Evry, France. This institute would provide opportunities for international cooperation on environmental issues and technology transfer related to environmental protection, monitoring, and restoration at US Department of Energy (DOE) facilities. The traveler also attended the Fourth International Conference on Environmental Contamination in Barcelona. Conference topics included environmental chemistry, land disposal of wastes, treatment of toxic wastes, micropollutants, trace organics, artificial radionuclides in the environment, and the use biomonitoring and biosystems for environmental assessment. The traveler presented a paper on The Fate of Radionuclides in Sewage Sludge Applied to Land.'' Those findings corresponded well with results from studies addressing the fate of fallout radionuclides from the Chernobyl nuclear accident. There was an exchange of new information on a number of topics of interest to DOE waste management and environmental restoration needs.

  14. GIG Technologies

    Science.gov (United States)

    2008-08-08

    caching • GIG as a sensor • Cyber SA/defense • Cross Domain Information Sharing • Multi-Level Security solutions • Enterprise Service Bus ( ESB ...Link Layer Technologies Integrated Link Layer All Optical Core For Terrestrial and Space Networks Separate Transmission Networks Mid-Term Integrated

  15. Geospatial Technology

    Science.gov (United States)

    Reed, Philip A.; Ritz, John

    2004-01-01

    Geospatial technology refers to a system that is used to acquire, store, analyze, and output data in two or three dimensions. This data is referenced to the earth by some type of coordinate system, such as a map projection. Geospatial systems include thematic mapping, the Global Positioning System (GPS), remote sensing (RS), telemetry, and…

  16. Sport Technology

    CSIR Research Space (South Africa)

    Kirkbride, T

    2007-11-01

    Full Text Available in design and manufacturing to virtual reality. There are carbon fiber materials used and in performance analysis that use video base technology. In the 1999 cricket World Cup, small earphones were used for Hansie to communicate with the coach and were later...

  17. Vacuum Technology

    Energy Technology Data Exchange (ETDEWEB)

    Biltoft, P J

    2004-10-15

    The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

  18. Acoustic resonance frequency locked photoacoustic spectrometer

    Science.gov (United States)

    Pilgrim, Jeffrey S.; Bomse, David S.; Silver, Joel A.

    2003-09-09

    A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell, the acoustic source having a source frequency; repeatedly and continuously sweeping the source frequency across the resonance frequency at a sweep rate; and employing an odd-harmonic of the source frequency sweep rate to maintain the source frequency sweep centered on the resonance frequency.

  19. Frequency-Locking in Coupled Chaotic Systems

    Institute of Scientific and Technical Information of China (English)

    HU Bam-Bi; LIU Zong-Hua; ZHENG Zhi-Gang

    2001-01-01

    A novel approach is presented for measuring the phase synchronization (frequency-locking) of coupled N nonidentical oscillators, which can characterize frequency-locking for chaotic systems without well-defined phase by measuring the mean frequency. Numerical simulations confirm the existence of frequency-locking. The relations between the mean frequency and the coupling strength and the frequency mismatch are given. For the coupled hyperchaotic systems, the frequency-locking can be better characterized by more than one mean frequency curves.

  20. High frequency conductivity of hot electrons in carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Amekpewu, M., E-mail: mamek219@gmail.com [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, S.Y. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Musah, R. [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, N.G. [Department of Mathematics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Abukari, S.S.; Dompreh, K.A. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana)

    2016-05-01

    High frequency conductivity of hot electrons in undoped single walled achiral Carbon Nanotubes (CNTs) under the influence of ac–dc driven fields was considered. We investigated semi-classically Boltzmann's transport equation with and without the presence of the hot electrons’ source by deriving the current densities in CNTs. Plots of the normalized current density versus frequency of ac-field revealed an increase in both the minimum and maximum peaks of normalized current density at lower frequencies as a result of a strong injection of hot electrons. The applied ac-field plays a twofold role of suppressing the space-charge instability in CNTs and simultaneously pumping an energy for lower frequency generation and amplification of THz radiations. These have enormous promising applications in very different areas of science and technology.

  1. High frequency conductivity of hot electrons in carbon nanotubes

    Science.gov (United States)

    Amekpewu, M.; Mensah, S. Y.; Musah, R.; Mensah, N. G.; Abukari, S. S.; Dompreh, K. A.

    2016-05-01

    High frequency conductivity of hot electrons in undoped single walled achiral Carbon Nanotubes (CNTs) under the influence of ac-dc driven fields was considered. We investigated semi-classically Boltzmann's transport equation with and without the presence of the hot electrons' source by deriving the current densities in CNTs. Plots of the normalized current density versus frequency of ac-field revealed an increase in both the minimum and maximum peaks of normalized current density at lower frequencies as a result of a strong injection of hot electrons. The applied ac-field plays a twofold role of suppressing the space-charge instability in CNTs and simultaneously pumping an energy for lower frequency generation and amplification of THz radiations. These have enormous promising applications in very different areas of science and technology.

  2. Frequency jumps in single chip microwave LC oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Gualco, Gabriele; Grisi, Marco; Boero, Giovanni, E-mail: giovanni.boero@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015 (Switzerland)

    2014-12-15

    We report on the experimental observation of oscillation frequency jumps in microwave LC oscillators fabricated using standard complementary metal-oxide-semiconductor technologies. The LC oscillators, operating at a frequency of about 20 GHz, consist of a single turn planar coil, a metal-oxide-metal capacitor, and two cross-coupled metal-oxide-semiconductor field effect transistors used as negative resistance network. At 300 K as well as at 77 K, the oscillation frequency is a continuous function of the oscillator bias voltage. At 4 K, frequency jumps as large as 30 MHz are experimentally observed. This behavior is tentatively attributed to the emission and capture of single electrons from defects and dopant atoms.

  3. Modelocked mid-infrared frequency combs in a silicon microresonator

    CERN Document Server

    Yu, Mengjie; Griffith, Austin G; Lipson, Michal; Gaeta, Alexander L

    2016-01-01

    Mid-infrared (mid-IR) frequency combs have broad applications in molecular spectroscopy and chemical/biological sensing. Recently developed microresonator-based combs in this wavelength regime could enable portable and robust devices using a single-frequency pump field. Here, we report the first demonstration of a modelocked microresonator-based frequency comb in the mid-IR spanning 2.4 {\\mu}m to 4.3 {\\mu}m. We observe high pump-to-comb conversion efficiency, in which 40% of the pump power is converted to the output comb power. Utilizing an integrated PIN structure allows for tuning the silicon microresonator and controling modelocking and cavity soliton formation, simplifying the generation, monitoring and stabilization of mid-IR frequency combs via free-carrier detection and control. Our results significantly advance microresonator-based comb technology towards a portable and robust mid-IR spectroscopic device that operates at low pump powers.

  4. Soviet precision timekeeping research and technology

    Energy Technology Data Exchange (ETDEWEB)

    Vessot, R.F.C.; Allan, D.W.; Crampton, S.J.B.; Cutler, L.S.; Kern, R.H.; McCoubrey, A.O.; White, J.D.

    1991-08-01

    This report is the result of a study of Soviet progress in precision timekeeping research and timekeeping capability during the last two decades. The study was conducted by a panel of seven US scientists who have expertise in timekeeping, frequency control, time dissemination, and the direct applications of these disciplines to scientific investigation. The following topics are addressed in this report: generation of time by atomic clocks at the present level of their technology, new and emerging technologies related to atomic clocks, time and frequency transfer technology, statistical processes involving metrological applications of time and frequency, applications of precise time and frequency to scientific investigations, supporting timekeeping technology, and a comparison of Soviet research efforts with those of the United States and the West. The number of Soviet professionals working in this field is roughly 10 times that in the United States. The Soviet Union has facilities for large-scale production of frequency standards and has concentrated its efforts on developing and producing rubidium gas cell devices (relatively compact, low-cost frequency standards of modest accuracy and stability) and atomic hydrogen masers (relatively large, high-cost standards of modest accuracy and high stability). 203 refs., 45 figs., 9 tabs.

  5. Accessibility and Usage of Technology by North Carolina Agriculture Teachers

    Science.gov (United States)

    Williams, Maegen R.; Warner, Wendy J.; Flowers, James L.; Croom, D. Barry

    2014-01-01

    This study examined the integration of technology into the instructional process in North Carolina agricultural education classrooms. The study used survey research methodology to collect information on the availability of instructional technology and the frequency of instructional technology use by North Carolina agriculture teachers. The study…

  6. Advanced Communications Technology Satellite (ACTS)

    Science.gov (United States)

    Olmstead, Dean A.; Schertler, Ronald J.

    The benefits that will be offered by the NASA-sponsored communication spacecraft ACTS which is scheduled for launch in 1992 are described together with examples of demonstrations on proposed data, video, and voice applications supported by the advanced ACTS technologies. Compared to existing satellite service, the ACTS will provide lower cost, better service, greater convenience, and improved service reliability of telecommunications to customers around the world. In addition, the pioneering ACTS technology will provide many capabilities qualitatively different from those of current satellite systems, such as on-demand assignment, frequency reuse, and the flexible targeting of spot beams directly to the very-small-aperture terminals at customer premises.

  7. Frequency domain processing of on-chip biphoton frequency comb

    CERN Document Server

    Jaramillo-Villegas, Jose A; Odele, Ogaga D; Leaird, Daniel E; Ou, Zhe-Yu; Qi, Minghao; Weiner, Andrew M

    2016-01-01

    Quantum information processing (QIP) promises to improve the security of our communications as well as to solve some algorithms with exponential complexity in polynomial time. Biphotons have been demonstrated as one of the most promising platforms for real implementations of QIP systems. In particular, time-bin entangled photons have been used for implementations of quantum gates which require highly stable interferometers. On the other hand, frequency-bin entanglement has been proposed to avoid the use of interferometers and the complexity of their stabilization, which potentially makes the implementation of quantum gates highly scalable. Through Fourier transform pulse shaping and electro-optic modulation, there has been a wide range of experiments that show control of entangled photons in the frequency domain. In addition, biphoton frequency combs (BFC) have also been generated using bulk optics and frequency filtering of broadband continuous biphoton spectra. However, on-chip entangled photon pair generat...

  8. Monolithically integrated absolute frequency comb laser system

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  9. Calibration of High Frequency MEMS Microphones

    Science.gov (United States)

    Shams, Qamar A.; Humphreys, William M.; Bartram, Scott M.; Zuckewar, Allan J.

    2007-01-01

    Understanding and controlling aircraft noise is one of the major research topics of the NASA Fundamental Aeronautics Program. One of the measurement technologies used to acquire noise data is the microphone directional array (DA). Traditional direction array hardware, consisting of commercially available condenser microphones and preamplifiers can be too expensive and their installation in hard-walled wind tunnel test sections too complicated. An emerging micro-machining technology coupled with the latest cutting edge technologies for smaller and faster systems have opened the way for development of MEMS microphones. The MEMS microphone devices are available in the market but suffer from certain important shortcomings. Based on early experiments with array prototypes, it has been found that both the bandwidth and the sound pressure level dynamic range of the microphones should be increased significantly to improve the performance and flexibility of the overall array. Thus, in collaboration with an outside MEMS design vendor, NASA Langley modified commercially available MEMS microphone as shown in Figure 1 to meet the new requirements. Coupled with the design of the enhanced MEMS microphones was the development of a new calibration method for simultaneously obtaining the sensitivity and phase response of the devices over their entire broadband frequency range. Over the years, several methods have been used for microphone calibration. Some of the common methods of microphone calibration are Coupler (Reciprocity, Substitution, and Simultaneous), Pistonphone, Electrostatic actuator, and Free-field calibration (Reciprocity, Substitution, and Simultaneous). Traditionally, electrostatic actuators (EA) have been used to characterize air-condenser microphones for wideband frequency ranges; however, MEMS microphones are not adaptable to the EA method due to their construction and very small diaphragm size. Hence a substitution-based, free-field method was developed to

  10. Electromagnetic interference from radio frequency identification inducing potentially hazardous incidents in critical care medical equipment

    NARCIS (Netherlands)

    Togt, R. van der; Lieshout, E.J. van; Hensbroek, R.; Beinat, E.; Binnekade, J.M.; Bakker, P.J.M.

    2008-01-01

    Context: Health care applications of autoidentification technologies, such as radio frequency identification (RFID), have been proposed to improve patient safety and also the tracking and tracing of medical equipment. However, electromagnetic interference (EMI) by RFID on medical devices has never

  11. Principle of frequency selection of terminology and general economic vocabulary for economic textbook for translation

    OpenAIRE

    Golandam А. K.

    2012-01-01

    Due to the rapid development of technology and increase production increased practical importance economic translation. This article discusses the frequency of words on the principle of selection economic translation.

  12. Principle of frequency selection of terminology and general economic vocabulary for economic textbook for translation

    Directory of Open Access Journals (Sweden)

    Golandam А. K.

    2012-06-01

    Full Text Available Due to the rapid development of technology and increase production increased practical importance economic translation. This article discusses the frequency of words on the principle of selection economic translation.

  13. A Space-Qualified Single Frequency Fiber Laser for LISA Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Single frequency high power lasers have been considered to be an enabling technology for NASA's Laser Interferometer Space Antenna (LISA). PolarOnyx proposes, for...

  14. Single Frequency Lasers for Space-Based Wind and Aerosol Lidar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR will develop single frequency cw laser technology for 2um lidar and UV interferometer locking control critical to NASA missions that will measure...

  15. Comparison of ultra-stable radio frequency signals synthesized from independent secondary microwave frequency standards

    CERN Document Server

    Hartnett, John G; Ivanov, Eugene N; Povey, Travis; Nand, Nitin R; Floch, Jean-Michel le

    2013-01-01

    The phase noise and frequency stability measurements of 1 GHz, 100 MHz, and 10 MHz signals are presented which have been synthesized from microwave cryogenic sapphire oscillators using ultra-low-vibration pulse-tube cryocooler technology. We present the measured data using independent cryogenic oscillators for the 100 MHz and 10 MHz synthesized signals, whereas previously we only estimated the expected results based on residual phase noise measurements, when only one cryogenic oscillator was available. In addition we present the design of a 1 GHz synthesizer using a Crystek voltage controlled oscillator phase locked to 1 GHz output derived from a cryogenic sapphire oscillator.

  16. High-frequency magnetic components

    CERN Document Server

    Kazimierczuk, Marian K

    2009-01-01

    If you are looking for a complete study of the fundamental concepts in magnetic theory, read this book. No other textbook covers magnetic components of inductors and transformers for high-frequency applications in detail. This unique text examines design techniques of the major types of inductors and transformers used for a wide variety of high-frequency applications including switching-mode power supplies (SMPS) and resonant circuits. It describes skin effect and proximity effect in detail to provide you with a sound understanding of high-frequency phenomena. As well as this, you will disco

  17. Frequency synthesizers concept to product

    CERN Document Server

    Chenakin, Alexander

    2011-01-01

    A frequency synthesizer is an electronic system for generating any of a range of frequencies from a single fixed oscillator. They are found in modern devices like radio receivers, mobile phones, and GPS systems. This comprehensive resource offers RF and microwave engineers a thorough overview of both well-established and recently developed frequency synthesizer design techniques. Professionals find expert guidance on all design aspects, including main architectures, key building blocks, and practical circuit implementation. Engineers learn the development process and gain a solid understanding

  18. Technology Programme

    Energy Technology Data Exchange (ETDEWEB)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo (ed.)

    2005-07-01

    The technology activities carried out by the Euratom-ENEA Association in the framework of the European Fusion Development Agreement concern the Next Step (International Thermonuclear Experimental Reactor - ITER), the Long-Term Programme (breeder blanket, materials, International Fusion Materials Irradiation Facility - IFMIF), Power Plant Conceptual Studies and Socio-Economic Studies. The Underlying Technology Programme was set up to complement the fusion activities as well to develop technologies with a wider range of interest. The Technology Programme mainly involves staff from the Frascati laboratories of the Fusion Technical and Scientific Unit and from the Brasimone laboratories of the Advanced Physics Technologies Unit. Other ENEA units also provide valuable contributions to the programme. ENEA is heavily engaged in component development/testing and in design and safety activities for the European Fusion Technology Programme. Although the work documented in the following covers a large range of topics that differ considerably because they concern the development of extremely complex systems, the high level of integration and coordination ensures the capability to cover the fusion system as a whole. In 2004 the most significant testing activities concerned the ITER primary beryllium-coated first wall. In the field of high-heat-flux components, an important achievement was the qualification of the process for depositing a copper liner on carbon fibre composite (CFC) hollow tiles. This new process, pre-brazed casting (PBC), allows the hot radial pressing (HRP) joining procedure to be used also for CFC-based armour monoblock divertor components. The PBC and HRP processes are candidates for the construction of the ITER divertor. In the materials field an important milestone was the commissioning of a new facility for chemical vapour infiltration/deposition, used for optimising silicon carbide composite (SiCf/SiC) components. Eight patents were deposited during 2004

  19. Ultrahigh and microwave frequency nanomechanical systems

    Science.gov (United States)

    Huang, Xue Ming Henry

    Nanodevices that operate with fundamental frequencies in the previously inaccessible microwave range (greater than 1 gigahertz) have been constructed. Two advances have been crucial to breaking the 1-GHz barrier in nanoelectromechanical systems (NEMS): the use of 3C- silicon carbide epilayers, and the development of balanced, high frequency displacement transducers. This achievement represents a significant advance in the quest for extremely high frequency nanoelectromechanical systems.However, silicon carbide nanomechanical resonators with fundamental frequencies in the ultrahigh frequency and microwave range have exhibited deteriorating quality factors compared to devices at lower frequencies, which could significantly restrict the application of this developing technology. Our experiments have established a strong correlation between silicon carbide surface roughness and deteriorating quality factor. Also, dissipation in such devices increases as the aspect ratio of the doubly clamped beams is reduced. Based on such observations, we have then demonstrated that the SiC free-free beam nanomechanical resonators offer significant improvement in quality factor compared to doubly clamped beam design operating at similar frequencies.Apart from 3C-SiC epilayers on silicon, polished 6H-SiC bulk material based NEMS are also made possible by our invention. A tilted Electron Cyclotron Resonance (ECR) etching technique has been developed to fabricate suspended nanomechanical structures from bulk 6H-SiC wafers. A suspended nanoscale, doubly clamped beam resonator has been made as an initial demonstration of this new fabrication method. Fundamental flexural mode mechanical resonance is detected at 171.2 MHz, with a quality factor of about 3000. The ability to fabricate 3-D suspended nanostructures from 6H-SiC is an important breakthrough in NEMS not only because it enables electronic integration, but also because it provides a unique platform for exploring the effects of

  20. The influences of low frequency noise on mental performance

    Directory of Open Access Journals (Sweden)

    J. Hatami

    2008-01-01

    Full Text Available AbstractBackground and Purpose: Although the evolution of industrial systems toward digital technologies decreased the exposure to high levels of noise, it has created some problems encountered with low level and provoking noise (low frequency noise. In the present work, the mental performance of students exposed to low frequency and reference noises at low and high levels (45 & 65 dB were studied. Additionally, other factors such as annoyance, sensitivity to low frequency noise and hearing status of participants were considered.Materials and Methods: After generating low frequency and reference noises required for the study, a pilot study was conducted. Then, 54 students participated in the main study after preliminary tests. Their mental performances were evaluated with standard psychological tests while they were exposed to low frequency and reference noises at 45 and 65 dBA.Results: The results showed that noise annoyance and low frequency noise sensitivity do not have a significant correlation with age and sex. The results also revealed that, low frequency noise at 65 dB can decrease concentration (P=0.003 and increase response time (P=0.039 of performance in comparison with low frequency noise at 45 dB. On the other hand, reference noise at 65 dB can increase speed (P<0.001 of performance in comparison with reference noise at 45 dB.Conclusion: Low frequency noise can reduce the mental performance and increase its response time.Key words: Low Frequency Noise, Reference Noise, Noise Annoyance, Mental PerformanceJ Mazand Univ Med Sci 2008; 18(63: 55-65(Persian

  1. Hearing Assistive Technology

    Science.gov (United States)

    ... for the Public / Hearing and Balance Hearing Assistive Technology Hearing Assistive Technology: FM Systems | Infrared Systems | Induction ... Assistive Technology Systems Solutions What are hearing assistive technology systems (HATS)? Hearing assistive technology systems (HATS) are ...

  2. Single-frequency reflection characterisation of shock tube excited plasma

    Science.gov (United States)

    Tian, Jing; Tang, Pu; Ma, Ping; Li, Lutong; Li, Ruiming; He, Ziyuan; Chen, Bo

    2017-08-01

    Plasma has been of great interest to engineers and scientists during the past few decades due to its wide applications. Besides, the plasma-sheath-caused lose of communication (i.e. re-entry blackout) that happens when a spacecraft re-enters the earth atmosphere is still a problem to be solved. The microwave characterisation of shock tube excited plasma has been an important method for exploring the transmission and reflection of microwave signals in plasma. The existing frequency sweep or multi-frequency technologies are not desirable for the characterisation of high-speed time-varying plasma generated in shock tubes. Hence, in this paper a novel signal-frequency approach is proposed to measure both electron density and collision frequency of plasma in shock tube. As frequency sweep is not required in this method, it is extremely suitable for characterising the shock tube excited high-speed time-varying plasma. The genetic algorithm is applied to extract electron density and collision frequency from the reflection coefficient. Simulation results demonstrate excellent accuracy for electron density within 1 010˜1 012 cm-3 and collision frequency within 5 ×1 010˜1 012 Hz. This work paves the way for a fast and compact microwave reflection measurement of shock tube generated plasma.

  3. A Survey of Advanced Microwave Frequency Measurement Techniques

    Directory of Open Access Journals (Sweden)

    Anand Swaroop Khare

    2012-06-01

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

  4. Capacitance-Based Frequency Adjustment of Micro Piezoelectric Vibration Generator

    Directory of Open Access Journals (Sweden)

    Xinhua Mao

    2014-01-01

    Full Text Available Micro piezoelectric vibration generator has a wide application in the field of microelectronics. Its natural frequency is unchanged after being manufactured. However, resonance cannot occur when the natural frequencies of a piezoelectric generator and the source of vibration frequency are not consistent. Output voltage of the piezoelectric generator will sharply decline. It cannot normally supply power for electronic devices. In order to make the natural frequency of the generator approach the frequency of vibration source, the capacitance FM technology is adopted in this paper. Different capacitance FM schemes are designed by different locations of the adjustment layer. The corresponding capacitance FM models have been established. Characteristic and effect of the capacitance FM have been simulated by the FM model. Experimental results show that the natural frequency of the generator could vary from 46.5 Hz to 42.4 Hz when the bypass capacitance value increases from 0 nF to 30 nF. The natural frequency of a piezoelectric vibration generator could be continuously adjusted by this method.

  5. Design & Implementation of High Switching & Low Phase Noise Frequency Synthesizer

    Directory of Open Access Journals (Sweden)

    Ali M. N. Hassan

    2006-01-01

    Full Text Available This research describes the design & implementation of frequency synthesizer using single loop Phase lock loop with the following specifications: Frequency range (1.5 – 2.75 GHz,Step size (1 MHz, Switching time 36.4 µs, & phase noise @10 kHz = -92dBc & spurious -100 dBc The development in I.C. technology provide the simplicity in the design of frequency synthesizer because it implements the phase frequency detector(PFD , prescalar & reference divider in single chip. Therefore our system consists of a single chip contains (low phase noise PFD, charge pump, prescalar & reference divider, voltage controlled oscillator , loop filter & reference oscillator. The single chip is used to provide the following properties :•Low power consumptionSmall size, light weight.Flexibility in selecting crystal oscillator frequencies to fit into the system frequency planning.•High reliability.The application of this synthesizer in frequency hopping systems, satellite communications & radar because it has high switching speed ,low phase noise & low spurious level.

  6. Piezoelectric films for high frequency ultrasonic transducers in biomedical applications.

    Science.gov (United States)

    Zhou, Qifa; Lau, Sienting; Wu, Dawei; Shung, K Kirk

    2011-02-01

    Piezoelectric films have recently attracted considerable attention in the development of various sensor and actuator devices such as nonvolatile memories, tunable microwave circuits and ultrasound transducers. In this paper, an overview of the state of art in piezoelectric films for high frequency transducer applications is presented. Firstly, the basic principles of piezoelectric materials and design considerations for ultrasound transducers will be introduced. Following the review, the current status of the piezoelectric films and recent progress in the development of high frequency ultrasonic transducers will be discussed. Then details for preparation and structure of the materials derived from piezoelectric thick film technologies will be described. Both chemical and physical methods are included in the discussion, namely, the sol-gel approach, aerosol technology and hydrothermal method. The electric and piezoelectric properties of the piezoelectric films, which are very important for transducer applications, such as permittivity and electromechanical coupling factor, are also addressed. Finally, the recent developments in the high frequency transducers and arrays with piezoelectric ZnO and PZT thick film using MEMS technology are presented. In addition, current problems and further direction of the piezoelectric films for very high frequency ultrasound application (up to GHz) are also discussed.

  7. Photonic Arbitrary Waveform Generation Technology

    Science.gov (United States)

    2006-06-01

    radar/ lidar , optical communications, and signal processing. Our key achievements are as follows: • Frequency domain based architecture using...and combining the result onto a photodetector . The derivative of the time varying voltage applied to the phase modulator determines the addition... photodetectors would also be warranted. 28 References [1] K. Nosu, “Advanced coherent lightwave technologies,” IEEE Commun. Magn,, vol. 26

  8. Manufacturing technology

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, J.A.; Floyd, H.L.; Goetsch, B.; Doran, L. [eds.

    1993-08-01

    This bulletin depicts current research on manufacturing technology at Sandia laboratories. An automated, adaptive process removes grit overspray from jet engine turbine blades. Advanced electronic ceramics are chemically prepared from solution for use in high- voltage varistors. Selective laser sintering automates wax casting pattern fabrication. Numerical modeling improves performance of photoresist stripper (simulation on Cray supercomputer reveals path to uniform plasma). And mathematical models help make dream of low- cost ceramic composites come true.

  9. High-frequency seafloor acoustics

    National Research Council Canada - National Science Library

    Jackson, D. R; Richardson, M. D

    2007-01-01

    This title provides access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics...

  10. Frequency Steered Acoustic Transducer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase II project is to fabricate, characterize, and verify performance of a new type of frequency steered acoustic transducer...

  11. Harvesting Low-Frequency (Nanogenerator.

    Science.gov (United States)

    Zi, Yunlong; Guo, Hengyu; Wen, Zhen; Yeh, Min-Hsin; Hu, Chenguo; Wang, Zhong Lin

    2016-04-26

    Electromagnetic generators (EMGs) and triboelectric nanogenerators (TENGs) are the two most powerful approaches for harvesting ambient mechanical energy, but the effectiveness of each depends on the triggering frequency. Here, after systematically comparing the performances of EMGs and TENGs under low-frequency motion (10-100 V) and independent of frequency so that most of the generated power can be effectively used to power the devices. Furthermore, a TENG also has advantages of light weight, low cost, and easy scale up through advanced structure designs. All these merits verify the possible killer application of a TENG for harvesting energy at low frequency from motions such as human motions for powering small electronics and possibly ocean waves for large-scale blue energy.

  12. Optical frequency combs generated mechanically

    CERN Document Server

    Sumetsky, M

    2016-01-01

    It is shown that a highly equidistant optical frequency comb can be generated by the parametric excitation of an optical bottle microresonator with nanoscale effective radius variation by its natural mechanical vibrations.

  13. Frequency Steered Acoustic Transducer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is to develop, fabricate, and characterize a novel frequency steered acoustic transducer (FSAT) for the...

  14. Geographies of High Frequency Trading

    DEFF Research Database (Denmark)

    Grindsted, Thomas Skou

    2016-01-01

    This paper investigates the geographies of high frequency trading. Today shares shift hands within micro seconds, giving rise to a form of financial geographies termed algorithmic capitalism. This notion refers to the different spatio-temporalities produced by high frequency trading, under...... the valuation of time. As high frequency trading accelerates financial markets, the paper examines the spatio-temporalities of automated trading by the ways in which the speed of knowledge exploitation in financial markets is not only of interest, but also the expansion between different temporalities....... The paper demonstrates how the intensification of time-space compression produces radical new dynamics in the financial market and develops information rent in HFT as convertible to a time rent and a spatio-temporal rent. The final section discusses whether high frequency trading only responds to crises...

  15. Emerging technologies

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shin-yee

    1993-03-01

    The mission of the Emerging Technologies thrust area at Lawrence Livermore National Laboratory is to help individuals establish technology areas that have national and commercial impact, and are outside the scope of the existing thrust areas. We continue to encourage innovative ideas that bring quality results to existing programs. We also take as our mission the encouragement of investment in new technology areas that are important to the economic competitiveness of this nation. In fiscal year 1992, we have focused on nine projects, summarized in this report: (1) Tire, Accident, Handling, and Roadway Safety; (2) EXTRANSYT: An Expert System for Advanced Traffic Management; (3) Odin: A High-Power, Underwater, Acoustic Transmitter for Surveillance Applications; (4) Passive Seismic Reservoir Monitoring: Signal Processing Innovations; (5) Paste Extrudable Explosive Aft Charge for Multi-Stage Munitions; (6) A Continuum Model for Reinforced Concrete at High Pressures and Strain Rates: Interim Report; (7) Benchmarking of the Criticality Evaluation Code COG; (8) Fast Algorithm for Large-Scale Consensus DNA Sequence Assembly; and (9) Using Electrical Heating to Enhance the Extraction of Volatile Organic Compounds from Soil.

  16. Technology Management

    DEFF Research Database (Denmark)

    Pilkington, Alan

    2014-01-01

    This paper reports a bibliometric analysis (co-citation network analysis) of 10 journals in the management of technology (MOT) field. As well as introducing various bibliometric ideas, network analysis tools identify and explore the concepts covered by the field and their inter-relationships. Spe......This paper reports a bibliometric analysis (co-citation network analysis) of 10 journals in the management of technology (MOT) field. As well as introducing various bibliometric ideas, network analysis tools identify and explore the concepts covered by the field and their inter......-relationships. Specific results from different levels of analysis show the different dimensions of technology management: • Co-word terms identify themes • Journal co-citation network: linking to other disciplines • Co-citation network show concentrations of themes The analysis shows that MOT has a bridging role...... in integrating ideas from several distinct disciplines. This suggests that management and strategy are central to MOT which essentially relates to the firm rather than policy. Similarly we have a dual focus on capabilities, but can see subtle differences in how we view these ideas, either through an inwards...

  17. Parametric effects of word frequency effect in memory for mixed frequency lists

    OpenAIRE

    Lohnas, Lynn J.; Kahana, Michael J.

    2013-01-01

    The word frequency paradox refers to the finding that low frequency words are better recognized than high frequency words yet high frequency words are better recalled than low frequency words. Rather than comparing separate groups of low and high frequency words, we sought to quantify the functional relation between word frequency and memory performance across the broad range of frequencies typically used in episodic memory experiments. Here we report that both low frequency and high frequenc...

  18. Day-Ahead Scheduling Considering Demand Response as a Frequency Control Resource

    Directory of Open Access Journals (Sweden)

    Yu-Qing Bao

    2017-01-01

    Full Text Available The development of advanced metering technologies makes demand response (DR able to provide fast response services, e.g., primary frequency control. It is recognized that DR can contribute to the primary frequency control like thermal generators. This paper proposes a day-ahead scheduling method that considers DR as a frequency control resource, so that the DR resources can be dispatched properly with other resources. In the proposed method, the objective of frequency control is realized by defining a frequency limit equation under a supposed contingency. The frequency response model is used to model the dynamics of system frequency. The nonlinear frequency limit equation is transformed to a linear arithmetic equation by piecewise linearization, so that the problem can be solved by mixed integer linear programming (MILP. Finally, the proposed method is verified on numerical examples.

  19. Primary Frequency Standards at NIST

    Science.gov (United States)

    2001-11-01

    Mode-Locked Laser, ” Physical Review Letters , 82,3568-337 I. J. Reicher, M. Niering, R. Holzwarth, M. Weitz, T. Udem, and T. W. Hansch, 2000, “Phase...Coherent Vacuum- Ultraviolet to Radio Frequency Comparison with a Mode-Locked Laser, ’’ Physical Review Letters , 84,3232-3235. M. Niering, R...Measurement of the Hydrogen IS- 2s Transition Frequency by Phase Coherent Comparison with a Microwave Cesium Fountain Clock,” Physical Review Letters , 84

  20. Microresonator Frequency Comb Optical Clock

    Science.gov (United States)

    2014-07-22

    Number Microresonator frequency comb optical clock Block 13: Supplementary Note © 2014 . Published in Optica , Vol. Ed. 0 1, (1) (2014), (, (1). DoD...Oscillators. http://dx.doi.org/10.1364/ OPTICA .1.000010 1. INTRODUCTION Optical frequency combs enable extraordinary measurement precision and accuracy...1, No. 1 / July 2014 / Optica 10 deviation for 1 s averaging is completely dominated by the Rb reference, and the microcomb contribution is only ɚ