WorldWideScience

Sample records for variable energy radio-frequency

  1. Radio Frequency Energy Harvesting Sources

    Directory of Open Access Journals (Sweden)

    Action NECHIBVUTE

    2017-12-01

    Full Text Available This radio frequency (RF energy harvesting is an emerging technology and research area that promises to produce energy to run low-power wireless devices. The great interest that has recently been paid to RF harvesting is predominantly driven by the great progress in both wireless communication systems and broadcasting technologies that have availed a lot of freely propagating ambient RF energy. The principle aim of an RF energy harvesting system is to convert the received ambient RF energy into usable DC power. This paper presents a state of the art concise review of RF energy harvesting sources for low power applications, and also discusses open research questions and future research directions on ambient RF energy harvesting.

  2. Radio Frequency Energy Harvesting for Long Lifetime Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Han, Bo; Nielsen, Rasmus Hjorth; Prasad, Ramjee

    2014-01-01

    , harvesting energy from the radio frequency (RF) waves gives the lowest system design. Previous research on RF energy harvesting is based on the model that the radio energy is omnidirectional in the air. In this paper, a directional transmission/receiving model is proposed which can further overcome the path...... loss of the RF signals. On the node level, a virtual floating gate based CMOS biasing is used for the energy conversion circuit. With the proposed technique, the sensor node is able to harvest the energy from base station up to 30 meters....

  3. Energy harvesting from radio frequency propagation using piezoelectric cantilevers

    KAUST Repository

    Al Ahmad, Mahmoud

    2012-02-01

    This work reports an induced strain in a piezoelectric cantilever due to radio frequency signal propagation. The piezoelectric actuator is coupled to radio frequency (RF) line through a gap of 0.25 mm. When a voltage signal of 10 Vpp propagates in the line it sets an alternating current in the actuator electrodes. This flowing current drives the piezoelectric cantilever to mechanical movement, especially when the frequency of the RF signal matches the mechanical resonant frequency of the cantilever. Output voltage signals versus frequency for both mechanical vibrational and RF signal excitations have been measured using different loads.© 2011 Elsevier Ltd. All rights reserved.

  4. Energy Saving Glass Lamination via Selective Radio Frequency Heating

    Energy Technology Data Exchange (ETDEWEB)

    Allan, Shawn M; Baranova, Inessa; Poley, Joseph; Reis, Henrique

    2012-02-27

    This project focused on advancing radio-frequency (RF) lamination technology closer to commercial implementation, in order to reduce the energy intensity of glass lamination by up to 90%. Lamination comprises a wide range of products including autoglass, architectural safety and innovative design glass, transparent armor (e.g. bullet proof glass), smart glass, mirrors, and encapsulation of photovoltaics. Lamination is also the fastest growing segment of glass manufacturing, with photovoltaics, architectural needs, and an anticipated transition to laminated side windows in vehicles. The state-of-the-art for glass lamination is to use autoclaves, which apply heat and uniform gas pressure to bond the laminates over the course of 1 to 18 hours. Laminates consist of layers of glass or other materials bonded with vinyl or urethane interlayers. In autoclaving, significant heat energy is lost heating the chamber, pressurized air, glass racks, and the glass. In RF lamination, the heat is generated directly in the vinyl interlayer, causing it to heat and melt quickly, in just 1 to 10 minutes, without significantly heating the glass or the equipment. The main purpose of this project was to provide evidence that low energy, rapid RF lamination quality met the same standards as conventionally autoclaved windows. The development of concepts for laminating curved glass with RF lamination was a major goal. Other primary goals included developing a stronger understanding of the lamination product markets described above, and to refine the potential benefits of commercial implementation. The scope of the project was to complete implementation concept studies in preparation for continuation into advanced development, pilot studies, and commercial implementation. The project consisted of 6 main tasks. The first dealt with lamination with poly-vinyl butyral (PVB) interlayers, which prior work had shown difficulties in achieving good quality laminates, working with Pilkington North

  5. Energy Saving Glass Lamination via Selective Radio Frequency Heating

    Energy Technology Data Exchange (ETDEWEB)

    Allan, Shawn M.

    2012-02-27

    This project focused on advancing radio-frequency (RF) lamination technology closer to commercial implementation, in order to reduce the energy intensity of glass lamination by up to 90%. Lamination comprises a wide range of products including autoglass, architectural safety and innovative design glass, transparent armor (e.g. bullet proof glass), smart glass, mirrors, and encapsulation of photovoltaics. Lamination is also the fastest growing segment of glass manufacturing, with photovoltaics, architectural needs, and an anticipated transition to laminated side windows in vehicles. The state-of-the-art for glass lamination is to use autoclaves, which apply heat and uniform gas pressure to bond the laminates over the course of 1 to 18 hours. Laminates consist of layers of glass or other materials bonded with vinyl or urethane interlayers. In autoclaving, significant heat energy is lost heating the chamber, pressurized air, glass racks, and the glass. In RF lamination, the heat is generated directly in the vinyl interlayer, causing it to heat and melt quickly, in just 1 to 10 minutes, without significantly heating the glass or the equipment. The main purpose of this project was to provide evidence that low energy, rapid RF lamination quality met the same standards as conventionally autoclaved windows. The development of concepts for laminating curved glass with RF lamination was a major goal. Other primary goals included developing a stronger understanding of the lamination product markets described above, and to refine the potential benefits of commercial implementation. The scope of the project was to complete implementation concept studies in preparation for continuation into advanced development, pilot studies, and commercial implementation. The project consisted of 6 main tasks. The first dealt with lamination with poly-vinyl butyral (PVB) interlayers, which prior work had shown difficulties in achieving good quality laminates, working with Pilkington North

  6. Nondestructive pasteurization of shell eggs using radio frequency energy

    Science.gov (United States)

    Shell eggs are on the top of the list of the 10 riskiest foods regulated by the Food and Drug Administration and 352 outbreaks from 1990 to 2006 were linked to eggs. The goals of this study were to design and assemble an apparatus to apply RF energy to shell eggs and to develop a process for pasteur...

  7. Treatment protocol development for disinfesting legumes using radio frequency energy

    Science.gov (United States)

    A pilot-scale 27 MHz, 6 kW RF unit was used to investigate RF heating and consequent quality attributes in three treated legumes. Only 5-7 min was needed to raise the central temperature of 3 kg samples to 60°C using RF energy, compared to more than 275 min when using forced hot air at 60°C. RF heat...

  8. A Novel Design of Radio Frequency Energy Relays on Power Transmission Lines

    OpenAIRE

    Jin Tong; Yigang He; Bing Li; Fangming Deng; Tao Wang

    2016-01-01

    In this paper, we investigate the energy problem of monitoring sensors on high-voltage power transmission lines and propose a wireless charging scheme for a Radio Frequency IDentification (RFID) sensor tag to solve a commercial efficiency problem: the maintenance-caused power outage. Considering the environmental influences on power transmission lines, a self-powered wireless energy relay is designed to meet the energy requirement of the passive RFID sensor tag. The relay can obtain the elect...

  9. A Novel Design of Radio Frequency Energy Relays on Power Transmission Lines

    Directory of Open Access Journals (Sweden)

    Jin Tong

    2016-06-01

    Full Text Available In this paper, we investigate the energy problem of monitoring sensors on high-voltage power transmission lines and propose a wireless charging scheme for a Radio Frequency IDentification (RFID sensor tag to solve a commercial efficiency problem: the maintenance-caused power outage. Considering the environmental influences on power transmission lines, a self-powered wireless energy relay is designed to meet the energy requirement of the passive RFID sensor tag. The relay can obtain the electric field energy from the transmission lines and wirelessly power the RFID sensor tags around for longer operating distance. A prototype of the energy relay is built and tested on a 110 kv line. The measurement results show that the energy relay can provide stable energy even with the influences of wind, noise and power outage. To our knowledge, it is the first work to power the RFID sensor tags on power transmission lines.

  10. Improved fluid simulations of radio-frequency plasmas using energy dependent ion mobilities

    Energy Technology Data Exchange (ETDEWEB)

    Greb, Arthur; Niemi, Kari; O' Connell, Deborah; Gans, Timo [York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom); Ennis, Gerard J.; MacGearailt, Niall [Intel Ireland Ltd., Leixlip (Ireland)

    2013-05-15

    Symmetric and asymmetric capacitively coupled radio-frequency plasmas in oxygen at 40 Pa, 300 V voltage amplitude and a discharge gap of 40 mm are investigated by means of one-dimensional numerical semi-kinetic fluid modeling on the basis of a simplified reaction scheme including the dominant positive and negative ions, background gas, and electrons. An improved treatment, by accounting for the dependence of ion mobilities on E/N, is compared to the standard approach, based on using zero-field mobility values only. The charged particle dynamics as a result of direct electron impact ionization of oxygen, secondary electron release from the electrodes, the spatial distribution of all involved particles as well as impact of geometry and model modification on ion energies is analyzed and compared to independent simulations and experiments.

  11. Identifying possible non-thermal effects of radio frequency energy on inactivating food microorganisms.

    Science.gov (United States)

    Kou, Xiaoxi; Li, Rui; Hou, Lixia; Zhang, Lihui; Wang, Shaojin

    2018-02-01

    Radio frequency (RF) heating has been successfully used for inactivating microorganisms in agricultural and food products. Athermal (non-thermal) effects of RF energy on microorganisms have been frequently proposed in the literature, resulting in difficulties for developing effective thermal treatment protocols. The purpose of this study was to identify if the athermal inactivation of microorganisms existed during RF treatments. Escherichia coli and Staphylococcus aureus in apple juice and mashed potato were exposed to both RF and conventional thermal energies to compare their inactivation populations. A thermal death time (TDT) heating block system was used as conventional thermal energy source to simulate the same heating treatment conditions, involving heating temperature, heating rate and uniformity, of a RF treatment at a frequency of 27.12 MHz. Results showed that a similar and uniform temperature distribution in tested samples was achieved in both heating systems, so that the central sample temperature could be used as representative one for evaluating thermal inactivation of microorganisms. The survival patterns of two target microorganisms in two food samples were similar both for RF and heating block treatments since their absolute difference of survival populations was  0.05) in inactivating bacteria between the RF and the heating block treatments at each set of temperatures. The solid temperature and microbial inactivation data demonstrated that only thermal effect of RF energy at 27.12 MHz was observed on inactivating microorganisms in foods. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Trapping ions from a fast beam in a radio-frequency ion trap: Exploring the energy exchange with the longitudinal radio-frequency field

    DEFF Research Database (Denmark)

    Svendsen, Annette; Lammich, Lutz; Vad Andersen, John Erik

    2013-01-01

    The possibility of injecting ions from an initially fast moving beam into a multipole radio-frequency (RF) ion trap without the use of buffer gas is described. The chosen trap geometry gives rise to an oscillating electric field along the direction of the incoming ions, and through an analytical...

  13. A study of radio frequency spectrum emitted by high energy air showers with LOFAR

    Science.gov (United States)

    Rossetto, Laura; Bonardi, Antonio; Buitink, Stijn; Corstanje, Arthur; Enriquez, J. Emilio; Falcke, Heino; Hörandel, Jörg R.; Mitra, Pragati; Mulrey, Katie; Nelles, Anna; Rachen, Jörg P.; Schellart, Pim; Scholten, Olaf; Thoudam, Satyendra; Trinh, Gia; ter Veen, Sander; Winchen, Tobias

    2017-03-01

    The high number density of radio antennas at the LOFAR core in Northern Netherlands allows to detect radio signals emitted by cosmic ray induced air showers, and to characterize the geometry of the observed cascade in a detailed way. We present here a study of the radio frequency spectrum in the 30 - 80 MHz regime, and its correlation with some geometrical parameters of the extensive air shower. An important goal of this study is to find a correlation between the frequency spectrum and the primary particle type. Preliminary results on how the frequency spectrum changes as function of distance to the shower axis, and as function of primary particles mass composition are shown. The final aim of this study is to find a method to infer information of primary cosmic rays in an independent way from the well-established fluorescence and surface detector techniques, in view of affirming the radio detection technique as reliable method for the study of high energy cosmic rays.

  14. Tailoring electron energy distribution functions through energy confinement in dual radio-frequency driven atmospheric pressure plasmas

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, C.; Waskoenig, J. [Centre for Plasma Physics, School of Maths and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Gans, T. [Centre for Plasma Physics, School of Maths and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom)

    2012-10-08

    A multi-scale numerical model based on hydrodynamic equations with semi-kinetic treatment of electrons is used to investigate the influence of dual frequency excitation on the effective electron energy distribution function (EEDF) in a radio-frequency driven atmospheric pressure plasma. It is found that variations of power density, voltage ratio, and phase relationship provide separate control over the electron density and the mean electron energy. This is exploited to directly influence both the phase dependent and time averaged effective EEDF. This enables tailoring the EEDF for enhanced control of non-equilibrium plasma chemical kinetics at ambient pressure and temperature.

  15. Heating uniformity and differential heating of insects in almonds associated with radio frequency energy

    Science.gov (United States)

    Radio frequency (RF) treatments have potential as alternatives to chemical fumigation for phytosanitary disinfestation treatments in the dried nut industry. To develop effective RF treatment protocols for almonds, it is desirable to determine heating uniformity and the occurrence of differential hea...

  16. 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.

  17. Ion velocities in the presheath of electronegative, radio-frequency plasmas measured by low-energy cutoff

    Energy Technology Data Exchange (ETDEWEB)

    Sobolewski, Mark A.; Wang, Yicheng; Goyette, Amanda [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

    2016-07-11

    Simple kinematic considerations indicate that, under certain conditions in radio-frequency (rf) plasmas, the amplitude of the low-energy peak in ion energy distributions (IEDs) measured at an electrode depends sensitively on ion velocities upstream, at the presheath/sheath boundary. By measuring this amplitude, the velocities at which ions exit the presheath can be determined and long-standing controversies regarding presheath transport can be resolved. Here, IEDs measured in rf-biased, inductively coupled plasmas in CF{sub 4} gas determined the presheath exit velocities of all significant positive ions: CF{sub 3}{sup +}, CF{sub 2}{sup +}, CF{sup +}, and F{sup +}. At higher bias voltages, we detected essentially the same velocity for all four ions. For all ions, measured velocities were significantly lower than the Bohm velocity and the electropositive ion sound speed. Neither is an accurate boundary condition for rf sheaths in electronegative gases: under certain low-frequency, high-voltage criteria defined here, either yields large errors in predicted IEDs. These results indicate that many widely used sheath models will need to be revised.

  18. Frequency, moisture content, and temperature dependent dielectric properties of potato starch related to drying with radio-frequency/microwave energy.

    Science.gov (United States)

    Zhu, Zhuozhuo; Guo, Wenchuan

    2017-08-24

    To develop advanced drying methods using radio-frequency (RF) or microwave (MW) energy, dielectric properties of potato starch were determined using an open-ended coaxial-line probe and network analyzer at frequencies between 20 and 4,500 MHz, moisture contents between 15.1% and 43.1% wet basis (w.b.), and temperatures between 25 and 75 °C. The results showed that both dielectric constant (ε') and loss factor (ε″) were dependent on frequency, moisture content, and temperature. ε' decreased with increasing frequency at a given moisture content or temperature. At low moisture contents (≤25.4% w.b.) or low temperatures (≤45 °C), ε″ increased with increasing frequency. However, ε″ changed from decrease to increase with increasing frequency at high moisture contents or temperatures. At low temperatures (25-35 °C), both ε' and ε″ increased with increasing moisture content. At low moisture contents (15.1-19.5% w.b.), they increased with increasing temperature. The change trends of ε' and ε″ were different and dependent on temperature and moisture content at their high levels. The penetration depth (d p ) decreased with increasing frequency. RF treatments may provide potential large-scale industrial drying application for potato starch. This research offers useful information on dielectric properties of potato starch related to drying with electromagnetic energy.

  19. LEP Radio Frequency Copper Cavity

    CERN Document Server

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  20. Design of an 81.25 MHz continuous-wave radio-frequency quadrupole accelerator for Low Energy Accelerator Facility

    Science.gov (United States)

    Ma, Wei; Lu, Liang; Xu, Xianbo; Sun, Liepeng; Zhang, Zhouli; Dou, Weiping; Li, Chenxing; Shi, Longbo; He, Yuan; Zhao, Hongwei

    2017-03-01

    An 81.25 MHz continuous wave (CW) radio frequency quadrupole (RFQ) accelerator has been designed for the Low Energy Accelerator Facility (LEAF) at the Institute of Modern Physics (IMP) of the Chinese Academy of Science (CAS). In the CW operating mode, the proposed RFQ design adopted the conventional four-vane structure. The main design goals are providing high shunt impendence with low power losses. In the electromagnetic (EM) design, the π-mode stabilizing loops (PISLs) were optimized to produce a good mode separation. The tuners were also designed and optimized to tune the frequency and field flatness of the operating mode. The vane undercuts were optimized to provide a flat field along the RFQ cavity. Additionally, a full length model with modulations was set up for the final EM simulations. Following the EM design, thermal analysis of the structure was carried out. In this paper, detailed EM design and thermal simulations of the LEAF-RFQ will be presented and discussed. Structure error analysis was also studied.

  1. Advanced anaerobic digestion of municipal sludge using a novel and energy-efficient radio frequency pretreatment system.

    Science.gov (United States)

    Hosseini Koupaie, E; Johnson, T; Eskicioglu, C

    2017-07-01

    Microwave (MW) sludge pretreatment systems are usually limited to a frequency of 2.45 GHz and the heating frequency is constrained by commercially available hardware. Studies using MW heating at this frequency have reported negative net energy balance (output energy as methane minus input electrical energy). This necessitates further research into more efficient thermal pretreatment technologies. In this research, a novel and highly efficient radio frequency (RF) pretreatment system at a frequency of 13.56 MHz was designed, implemented, and tested for the first time. The system was custom-designed based on the dielectric characteristics of thickened waste activated sludge (TWAS) to achieve a very efficient and uniform heating system. The effects of three factors including pretreatment method (RF vs. MW), final temperature (60, 90 and 120 °C), and stationary (holding) time (0, 1 and 2 h) on sludge solubilization and performance of mesophilic batch anaerobic digestion were evaluated simultaneously. Energy measurements were also made to compare the efficiency of the custom-designed RF and conventional MW heating systems. The differences in sludge disintegration (solubilization) using the RF and MW pretreatment systems were negligible (P > 0.05). No statistically significant difference was also observed between the two pretreatment systems in terms of mesophilic biogas production rate and extent (P > 0.05). The energy efficiency of the RF pretreatment system was measured between 67.3 and 95.5% for the temperature range of 25-120 °C which was significantly higher than that of the MW system efficiency which varied from 37 to 43%. Overall, the average input energy of the RF system was less than half of the energy consumed during the operation of the MW system to achieve a same target temperature. Considering the results of this research, the RF heating at a frequency of 13.56 MHz is suggested as an effective and energy-efficient technique for thermal

  2. Radio frequency spectrum management

    Science.gov (United States)

    Sujdak, E. J., Jr.

    1980-03-01

    This thesis is a study of radio frequency spectrum management as practiced by agencies and departments of the Federal Government. After a brief introduction to the international agency involved in radio frequency spectrum management, the author concentrates on Federal agencies engaged in frequency management. These agencies include the National Telecommunications and Information Administration (NTIA), the Interdepartment Radio Advisory Committee (IRAC), and the Department of Defense (DoD). Based on an analysis of Department of Defense frequency assignment procedures, recommendations are given concerning decentralizing military frequency assignment by delegating broader authority to unified commanders. This proposal includes a recommendation to colocate the individual Service frequency management offices at the Washington level. This would result in reduced travel costs, lower manpower requirements, and a common tri-Service frequency management data base.

  3. Radio Frequency Spectrum Management

    Science.gov (United States)

    1980-03-01

    limits, emmission standards, etc., cover many pages. Other available non-technical policy statements are of the motherhood-and-apple-pie ilk. Further...and 2) by allowing the onscene commander who is acutely aware of the radio frequency emmission environment in his area to make assignments. The author...need for investment in specific human capi- tal vice on the job experience, it will never eliminate it. Rather vice education and training in

  4. Energy resolved actinometry for simultaneous measurement of atomic oxygen densities and local mean electron energies in radio-frequency driven plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Greb, Arthur, E-mail: ag941@york.ac.uk; Niemi, Kari; O' Connell, Deborah; Gans, Timo [York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom)

    2014-12-08

    A diagnostic method for the simultaneous determination of atomic oxygen densities and mean electron energies is demonstrated for an atmospheric pressure radio-frequency plasma jet. The proposed method is based on phase resolved optical emission measurements of the direct and dissociative electron-impact excitation dynamics of three distinct emission lines, namely, Ar 750.4 nm, O 777.4 nm, and O 844.6 nm. The energy dependence of these lines serves as basis for analysis by taking into account two line ratios. In this frame, the method is highly adaptable with regard to pressure and gas composition. Results are benchmarked against independent numerical simulations and two-photon absorption laser-induced fluorescence experiments.

  5. 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...

  6. The effects of 2.45 GHz radio frequency energy on neurological tissue genes using an unrestrained murine model in vivo

    Science.gov (United States)

    Stevens, Brandon William

    The effects that radio frequency (RF) energy has on the body is currently an inconclusive and controversial topic. This is in part due to the differences and issues that can be found in previous studies. This thesis describes a study on the effect of continuous RF energy on the genome of in vivo mouse brain tissue for a duration of 31 days. To address the issues found in previous studies a new standardized procedure was followed. The genome of the brain tissue was quantified using RNA-seq and then analyzed using statistical combinations and empirical p-values. Transcripts with their respective p-values were uploaded into Integrity Pathway Analysis® to determine genes associated disease and function within the brain tissue. The results from this study provided evidence that supports RF energy induces changes in the genome. Additionally, the results provided evidence of the first reported case of a potential RF-controlled genetic transistor.

  7. Fast ion energy distribution from third harmonic radio frequency heating measured with a single crystal diamond detector at the Joint European Torus

    Energy Technology Data Exchange (ETDEWEB)

    Nocente, M.; Rebai, M.; Gorini, G. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Istituto di Fisica del Plasma “P. Caldirola,” Consiglio Nazionale delle Ricerche, Milano (Italy); Cazzaniga, C. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Istituto di Fisica del Plasma “P. Caldirola,” Consiglio Nazionale delle Ricerche, Milano (Italy); Rutherford Appleton Laboratory, ISIS Facility, Didcot (United Kingdom); Tardocchi, M.; Giacomelli, L.; Muraro, A. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Istituto di Fisica del Plasma “P. Caldirola,” Consiglio Nazionale delle Ricerche, Milano (Italy); Binda, F.; Eriksson, J. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Sharapov, S. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Collaboration: (EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)

    2015-10-15

    Neutron spectroscopy measurements with a single crystal diamond detector have been carried out at JET, for the first time in an experiment aimed at accelerating deuterons to MeV energies with radio frequency heating at the third harmonic. Data are interpreted by means of the expected response function of the detector and are used to extract parameters of the highly non-Maxwellian distribution function generated in this scenario. A comparison with observations using a time of flight and liquid scintillator neutron spectrometers is also presented. The results demonstrate the capability of diamond detectors to contribute to fast ion physics studies at JET and are of more general relevance in view of the application of such detectors for spectroscopy measurements in the neutron camera of next step tokamak devices.

  8. Foundations for radio frequency engineering

    CERN Document Server

    Geyi, Wen

    2015-01-01

    The book provides a comprehensive coverage of the fundamental topics in microwave engineering, antennas and wave propagation, and electromagnetic compatibility, including electromagnetic boundary value problems, waveguide theory, microwave resonators, antennas and wave propagation, microwave circuits, principles of electromagnetic compatibility designs, information theory and systems. Deals systematically with fundamental problems in radio frequency engineering, this important volume provides an updated treatment of radio frequency theory and techniques. The book can be used as a one-semester course for senior and first-year graduate students or as a reference for radio frequency engineers and applied physicists.

  9. 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...

  10. radio frequency based radio frequency based water level monitor

    African Journals Online (AJOL)

    eobe

    Key words: radio frequency, PIC microcontroller, encoder, decoder, water pump, residential. 1. ... The sensors emit high frequency (20kHz to 200 kHz) acoustic waves that are reflected back to and detected by the emitting transducer [2-4]. In addition, optical interface ... is another method; in this method optical sensors are.

  11. Radio frequency modulation made easy

    CERN Document Server

    Faruque, Saleh

    2017-01-01

    This book introduces Radio Frequency Modulation to a broad audience. The author blends theory and practice to bring readers up-to-date in key concepts, underlying principles and practical applications of wireless communications. The presentation is designed to be easily accessible, minimizing mathematics and maximizing visuals.

  12. Radio frequency propagation made easy

    CERN Document Server

    Faruque, Saleh

    2015-01-01

    This book introduces Radio Frequency Propagation to a broad audience.  The author blends theory and practice to bring readers up-to-date in key concepts, underlying principles and practical applications of wireless communications.  The presentation is designed to be easily accessible, minimizing mathematics and maximizing visuals.

  13. Radio frequency energy harvesting from a feeding source in a passive deep brain stimulation device for murine preclinical research.

    Science.gov (United States)

    Hosain, Md Kamal; Kouzani, Abbas Z; Tye, Susannah J; Samad, Mst Fateha; Kale, Rajas P; Bennet, Kevin E; Manciu, Felicia S; Berk, Michael

    2015-10-01

    This paper presents the development of an energy harvesting circuit for use with a head-mountable deep brain stimulation (DBS) device. It consists of a circular planar inverted-F antenna (PIFA) and a Schottky diode-based Cockcroft-Walton 4-voltage rectifier. The PIFA has the volume of π × 10(2) × 1.5 mm(3), resonance frequency of 915 MHz, and bandwidth of 16 MHz (909-925 MHz) at a return loss of -10 dB. The rectifier offers maximum efficiency of 78% for the input power of -5 dBm at a 5 kΩ load resistance. The developed rectenna operates efficiently at 915 MHz for the input power within -15 dBm to +5 dBm. For operating a DBS device, the DC voltage of 2 V is recorded from the rectenna terminal at a distance of 55 cm away from a 26.77 dBm transmitter in free space. An in-vitro test of the DBS device is presented. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  14. Radio Frequency Power Load and Associated Method

    Science.gov (United States)

    Srinivasan, V. Karthik (Inventor); Freestone, Todd M. (Inventor); Sims, William Herbert, III (Inventor)

    2014-01-01

    A radio frequency power load and associated method. A radio frequency power load apparatus may include a container with an ionized fluid therein. The apparatus may include one conductor immersed in a fluid and another conductor electrically connected to the container. A radio frequency transmission system may include a radio frequency transmitter, a radio frequency amplifier connected to the transmitter and a radio frequency power load apparatus connected to the amplifier. The apparatus may include a fluid having an ion source therein, one conductor immersed in a fluid, and another conductor electrically connected to the container. A method of dissipating power generated by a radio frequency transmission system may include constructing a waveguide with ionized fluid in a container and connecting the waveguide to an amplifier of the transmission system.

  15. Chemically Induced Radio-frequency Emission and Chemical Radiophysics

    Science.gov (United States)

    Buchachenko, Anatolii L.; Berdinskii, V. L.

    1983-01-01

    Chemical reactions involving free radicals can yield molecules with inverted populations of the nuclear Zeeman levels and able to store energy in the nuclear Zeeman reservoir. These molecules produce a radio-frequency electromagnetic field which induces radiative transitions between the Zeeman levels resulting in the conversion of the stored energy into radio-frequency emission from the molecules. The dependence of the recombination probability of the radicals on their spin state allows the elementary acts of radical reactions to be controlled by the application of radio-frequency electromagnetic fields ("chemical" radio receiver). The generation and reception of r.f. radiation in chemical reactions are the object of a new field of science: chemical radiophysics. 29 references.

  16. Nonthermal processing by radio frequency electric fields

    Science.gov (United States)

    Radio frequency electric fields (RFEF) processing is relatively new and has been shown to inactivate bacteria in apple juice, orange juice and apple cider at moderately low temperatures. Key equipment components of the process include a radio frequency power supply and a treatment chamber that is ca...

  17. Development of radio frequency treatments for dried pulses

    Science.gov (United States)

    Chemical fumigants are typically used to disinfest dried pulses of insect pests before shipment to importing countries, but the industry is exploring non-chemical alternatives. One possible alternative is the use of radio frequency (RF) energy to rapidly heat product to insecticidal levels. The cowp...

  18. DEMONSTRATION BULLETIN: RADIO FREQUENCY HEATING - IIT RESEARCH INSTITUTE

    Science.gov (United States)

    Radio frequency heating (RFH) is a process that uses electromagnetic energy generated by radio waves to heat soil in situ, thereby potentially enhancing the performance of standard soil vapor extraction (SVE) technologies. An RFH system developed by the IIT Research Institute ...

  19. Determining radio frequency heating uniformity in mixed beans for disinfestations

    Science.gov (United States)

    Our laboratory collaborates with USDA-ARS in Parlier, CA in developing thermal treatments based on radio frequency (RF) energy for insect control in legumes to meet postharvest phytosanitary regulations for international market. Our current study focuses on lentils and chickpeas that are two importa...

  20. Commissioning of helium injector for coupled radio frequency quadrupole and separated function radio frequency quadrupole accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Shixiang, E-mail: sxpeng@pku.edu.cn; Chen, Jia; Ren, Haitao; Zhao, Jie; Xu, Yuan; Zhang, Tao; Xia, Wenlong; Gao, Shuli; Wang, Zhi; Luo, Yuting; Guo, Zhiyu [SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871 (China); Zhang, Ailing; Chen, Jia' er [SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2014-02-15

    A project to study a new type of acceleration structure has been launched at Peking University, in which a traditional radio frequency quadrupole (RFQ) and a separated function radio frequency quadrupole are coupled in one cavity to accelerate the He+ beam. A helium injector for this project is developed. The injector consists of a 2.45 GHz permanent magnet electron cyclotron resonance ion source and a 1.16 m long low energy beam transport (LEBT). The commissioning of this injector was carried out and an onsite test was held in June 2013. A 14 mA He+ beam with the energy of 30 keV has been delivered to the end of the LEBT, where a diaphragm with the diameter of 7 mm is located. The position of the diaphragm corresponds to the entrance of the RFQ electrodes. The beam emittance and fraction were measured after the 7 mm diaphragm. Its rms emittance is about 0.14 π mm mrad and the fraction of He+ is about 99%.

  1. Improved fire resistant radio frequency anechoic materials

    Science.gov (United States)

    Robinson, D. A.

    1969-01-01

    Protective, flameproof foam covering improves the resistance to fire and surface contamination of low-cost radio frequency absorbing and shielding anechoic materials. This promotes safety of operating personnel and equipment being tested in an otherwise combustible anechoic chamber.

  2. An amplitude modulated radio frequency plasma generator

    Science.gov (United States)

    Lei, Fan; Li, Xiaoping; Liu, Yanming; Liu, Donglin; Yang, Min; Xie, Kai; Yao, Bo

    2017-04-01

    A glow discharge plasma generator and diagnostic system has been developed to study the effects of rapidly variable plasmas on electromagnetic wave propagation, mimicking the plasma sheath conditions encountered in space vehicle reentry. The plasma chamber is 400 mm in diameter and 240 mm in length, with a 300-mm-diameter unobstructed clear aperture. Electron densities produced are in the mid 1010 electrons/cm3. An 800 W radio frequency (RF) generator is capacitively coupled through an RF matcher to an internally cooled stainless steel electrode to form the plasma. The RF power is amplitude modulated by a waveform generator that operates at different frequencies. The resulting plasma contains electron density modulations caused by the varying power levels. A 10 GHz microwave horn antenna pair situated on opposite sides of the chamber serves as the source and detector of probe radiation. The microwave power feed to the source horn is split and one portion is sent directly to a high-speed recording oscilloscope. On mixing this with the signal from the pickup horn antenna, the plasma-induced phase shift between the two signals gives the path-integrated electron density with its complete time dependent variation. Care is taken to avoid microwave reflections and extensive shielding is in place to minimize electronic pickup. Data clearly show the low frequency modulation of the electron density as well as higher harmonics and plasma fluctuations.

  3. Radio Frequency Electromagnetic Radiation From Streamer Collisions.

    Science.gov (United States)

    Luque, Alejandro

    2017-10-16

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  4. Radio Frequency Electromagnetic Radiation From Streamer Collisions

    Science.gov (United States)

    Luque, Alejandro

    2017-10-01

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  5. Incorporation model of N into GaInNAs alloys grown by radio-frequency plasma-assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Aho, A.; Korpijärvi, V.-M.; Tukiainen, A.; Puustinen, J.; Guina, M. [Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3, FI-33720 Tampere (Finland)

    2014-12-07

    We present a Maxwell-Boltzmann electron energy distribution based model for the incorporation rate of nitrogen into GaInNAs grown by molecular beam epitaxy (MBE) using a radio frequency plasma source. Nitrogen concentration is predicted as a function of radio-frequency system primary resistance, N flow, and RF power, and group III growth rate. The semi-empirical model is shown to be repeatable with a maximum error of 6%. The model was validated for two different MBE systems by growing GaInNAs on GaAs(100) with variable nitrogen composition of 0%–6%.

  6. Low reflectance radio frequency load

    Science.gov (United States)

    Ives, R. Lawrence; Mizuhara, Yosuke M

    2014-04-01

    A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

  7. 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

  8. Characteristics of Radio-Frequency Circuits Utilizing Ferroelectric Capacitors

    Science.gov (United States)

    Eskridge, Michael; Gui, Xiao; MacLeod, Todd; Ho, Fat D.

    2011-01-01

    Ferroelectric capacitors, most commonly used in memory circuits and variable components, were studied in simple analog radio-frequency circuits such as the RLC resonator and Colpitts oscillator. The goal was to characterize the RF circuits in terms of frequency of oscillation, gain, etc, using ferroelectric capacitors. Frequencies of oscillation of both circuits were measured and studied a more accurate resonant frequency can be obtained using the ferroelectric capacitors. Many experiments were conducted and data collected. A model to simulate the experimental results will be developed. Discrepancies in gain and frequency in these RF circuits when conventional capacitors are replaced with ferroelectric ones were studied. These results will enable circuit designers to anticipate the effects of using ferroelectric components in their radio- frequency applications.

  9. Vacuum arc localization in CLIC prototype radio frequency accelerating structures

    CERN Document Server

    AUTHOR|(CDS)2091976; Koivunen, Visa

    2016-04-04

    A future linear collider capable of reaching TeV collision energies should support accelerating gradients beyond 100 MV/m. At such high fields, the occurrence of vacuum arcs have to be mitigated through conditioning, during which an accelerating structure’s resilience against breakdowns is slowly increased through repeated radio frequency pulsing. Conditioning is very time and resource consuming, which is why developing more efficient procedures is desirable. At CERN, conditioning related research is conducted at the CLIC high-power X-band test stands. Breakdown localization is an important diagnostic tool of accelerating structure tests. Abnormal position distributions highlight issues in structure design, manufacturing or operation and may consequently help improve these processes. Additionally, positioning can provide insight into the physics of vacuum arcs. In this work, two established positioning methods based on the time-difference-ofarrival of radio frequency waves are extended. The first method i...

  10. Radio frequency channel coding made easy

    CERN Document Server

    Faruque, Saleh

    2016-01-01

    This book introduces Radio Frequency Channel Coding to a broad audience. The author blends theory and practice to bring readers up-to-date in key concepts, underlying principles and practical applications of wireless communications. The presentation is designed to be easily accessible, minimizing mathematics and maximizing visuals.

  11. High Temperature Radio Frequency Loads

    CERN Document Server

    Federmann, S; Grudiev, A; Montesinos, E; Syratchev, I

    2011-01-01

    In the context of energy saving and recovery requirements the design of reliable and robust RF power loads which permit a high outlet temperature and high pressure of the cooling water is desirable. Cooling water arriving at the outlet withmore than 150 ◦C and high pressure has a higher value than water with 50 ◦C under low pressure. Conventional RF power loads containing dielectric and magnetic materials as well as sensitive ceramic windows usually do not permit going much higher than 90 ◦C. Here we present and discuss several design concepts for "metal only" RF high power loads. One concept is the application of magnetic steel corrugated waveguides near cutoff – this concept could find practical use above several GHz. Another solution are resonant structures made of steel to be installed in large waveguides for frequencies of 500 MHz or lower. Similar resonant structures above 100 MHz taking advantage of the rather high losses of normal steel may also be used in coaxial line geometries with large di...

  12. Radio frequency-assisted fast superconducting switch

    Energy Technology Data Exchange (ETDEWEB)

    Solovyov, Vyacheslav; Li, Qiang

    2017-12-05

    A radio frequency-assisted fast superconducting switch is described. A superconductor is closely coupled to a radio frequency (RF) coil. To turn the switch "off," i.e., to induce a transition to the normal, resistive state in the superconductor, a voltage burst is applied to the RF coil. This voltage burst is sufficient to induce a current in the coupled superconductor. The combination of the induced current with any other direct current flowing through the superconductor is sufficient to exceed the critical current of the superconductor at the operating temperature, inducing a transition to the normal, resistive state. A by-pass MOSFET may be configured in parallel with the superconductor to act as a current shunt, allowing the voltage across the superconductor to drop below a certain value, at which time the superconductor undergoes a transition to the superconducting state and the switch is reset.

  13. 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.

  14. REVIEW OF IMPROVEMENTS IN RADIO FREQUENCY PHOTONICS

    Science.gov (United States)

    2017-09-01

    AFRL-RY-WP-TR-2017-0156 REVIEW OF IMPROVEMENTS IN RADIO FREQUENCY PHOTONICS Preetpaul S. Devgan RF/EO Subsystems Branch Aerospace Components...Center (DTIC) (http://www.dtic.mil). AFRL-RY-WP-TR-2017-0156 HAS BEEN REVIEWED AND IS APPROVED FOR PUBLICATION IN ACCORDANCE WITH ASSIGNED DISTRIBUTION...public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions

  15. Radio Frequency Identification (RFID) und Dokumentenlogistik

    OpenAIRE

    Bioly, Sascha; Klumpp, Matthias

    2009-01-01

    This paper presents the development and technical concepts of radio frequency identification (RFID) as well as requirements of document logistics. Combining the two topics possibilities of implementing RFID technologies in document logistics (in finance) are discussed. This highlights the future potential of RFID systems in logistics in general as even in 'low-cost' and 'low-attention' areas as document logistics relevant business impacts and cost savings can be stipulated.

  16. 48 CFR 211.275 - Radio frequency identification.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Radio frequency identification. 211.275 Section 211.275 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS... Requirements Documents 211.275 Radio frequency identification. ...

  17. Inkjet Printed Radio Frequency Passive Components

    KAUST Repository

    McKerricher, Garret

    2015-12-01

    Inkjet printing is a mature technique for colourful graphic arts. It excels at customized, large area, high resolution, and small volume production. With the developments in conductive, and dielectric inks, there is potential for large area inkjet electronics fabrication. Passive radio frequency devices can benefit greatly from a printing process, since the size of these devices is defined by the frequency of operation. The large size of radio frequency passives means that they either take up expensive space “on chip” or that they are fabricated on a separate lower cost substrate and somehow bonded to the chips. This has hindered cost-sensitive high volume applications such as radio frequency identification tags. Substantial work has been undertaken on inkjet-printed conductors for passive antennas on microwave substrates and even paper, yet there has been little work on the printing of the dielectric materials aimed at radio frequency passives. Both the conductor and dielectric need to be integrated to create a multilayer inkjet printing process that is capable of making quality passives such as capacitors and inductors. Three inkjet printed dielectrics are investigated in this thesis: a ceramic (alumina), a thermal-cured polymer (poly 4 vinyl phenol), and a UV-cured polymer (acrylic based). For the conductor, both a silver nanoparticle ink as well as a custom in-house formulated particle-free silver ink are explored. The focus is on passives, mainly capacitors and inductors. Compared to low frequency electronics, radio frequency components have additional sensitivity regarding skin depth of the conductor and surface roughness, as well as dielectric constant and loss tangent of the dielectric. These concerns are investigated with the aim of making the highest quality components possible and to understand the current limitations of inkjet-fabricated radio frequency devices. An inkjet-printed alumina dielectric that provides quality factors of 200 and high

  18. Carbon nanotube radio-frequency electronics

    Science.gov (United States)

    Zhong, Donglai; Zhang, Zhiyong; Peng, Lian-Mao

    2017-05-01

    Carbon nanotube (CNT) is considered a promising material for radio-frequency (RF) applications, owing to its high carrier mobility and saturated drift velocity, as well as ultra-small intrinsic gate capacitance. Here, we review progress on CNT-based devices and integrated circuits for RF applications, including theoretical projection of RF performance of CNT-based devices, preparation of CNT materials, fabrication, optimization of RF field-effect transistors (FETs) structures, and ambipolar FET-based RF applications, and we outline challenges and prospects of CNT-based RF applications.

  19. Modulation of radio frequency signals by ULF waves

    Directory of Open Access Journals (Sweden)

    C. L. Waters

    2007-06-01

    Full Text Available The ionospheric plasma is continually perturbed by ultra-low frequency (ULF; 1–100 mHz plasma waves that are incident from the magnetosphere. In this paper we present a combined experimental and modeling study of the variation in radio frequency of signals propagating in the ionosphere due to the interaction of ULF wave energy with the ionospheric plasma. Modeling the interaction shows that the magnitude of the ULF wave electric field, e, and the geomagnetic field, B0, giving an e×B0 drift, is the dominant mechanism for changing the radio frequency. We also show how data from high frequency (HF Doppler sounders can be combined with HF radar data to provide details of the spatial structure of ULF wave energy in the ionosphere. Due to spatial averaging effects, the spatial structure of ULF waves measured in the ionosphere may be quite different to that obtained using ground based magnetometer arrays. The ULF wave spatial structure is shown to be a critical parameter that determines how ULF wave effects alter the frequency of HF signals propagating through the ionosphere.

  20. Modulation of radio frequency signals by ULF waves

    Directory of Open Access Journals (Sweden)

    C. L. Waters

    2007-06-01

    Full Text Available The ionospheric plasma is continually perturbed by ultra-low frequency (ULF; 1–100 mHz plasma waves that are incident from the magnetosphere. In this paper we present a combined experimental and modeling study of the variation in radio frequency of signals propagating in the ionosphere due to the interaction of ULF wave energy with the ionospheric plasma. Modeling the interaction shows that the magnitude of the ULF wave electric field, e, and the geomagnetic field, B0, giving an e×B0 drift, is the dominant mechanism for changing the radio frequency. We also show how data from high frequency (HF Doppler sounders can be combined with HF radar data to provide details of the spatial structure of ULF wave energy in the ionosphere. Due to spatial averaging effects, the spatial structure of ULF waves measured in the ionosphere may be quite different to that obtained using ground based magnetometer arrays. The ULF wave spatial structure is shown to be a critical parameter that determines how ULF wave effects alter the frequency of HF signals propagating through the ionosphere.

  1. Project 8: Using Radio Frequencies to Measure the Neutrino Mass

    CERN Document Server

    Oblath, N S

    2011-01-01

    It is well known that the neutrino masses affect the shape of the energy spectrum of tritium beta-decay electrons. However, experiments have yet to measure that distortion. The Project 8 experiment proposes to measure the spectral distortion in a novel way: using radio-frequency techniques to detect and measure the energies of the beta-decay electrons. We plan on measuring the radiation created from the cyclotron motion of the electrons in a strong magnetic field. I will report on the status of a prototype that is designed to demonstrate single-electron detection at energies near the tritium endpoint, 18.6 keV. I will also discuss the possibilities for scaling up to a neutrino-mass experiment.

  2. Water based fluidic radio frequency metamaterials

    Science.gov (United States)

    Cai, Xiaobing; Zhao, Shaolin; Hu, Mingjun; Xiao, Junfeng; Zhang, Naibo; Yang, Jun

    2017-11-01

    Electromagnetic metamaterials offer great flexibility for wave manipulation and enable exceptional functionality design, ranging from negative refraction, anomalous reflection, super-resolution imaging, transformation optics to cloaking, etc. However, demonstration of metamaterials with unprecedented functionalities is still challenging and costly due to the structural complexity or special material properties. Here, we demonstrate for the first time the versatile fluidic radio frequency metamaterials with negative refraction using a water-embedded and metal-coated 3D architecture. Effective medium analysis confirms that metallic frames create an evanescent environment while simultaneously water cylinders produce negative permeability under Mie resonance. The water-metal coupled 3D architectures and the accessory devices for measurement are fabricated by 3D printing with post electroless deposition. Our study also reveals the great potential of fluidic metamaterials and versatility of the 3D printing process in rapid prototyping of customized metamaterials.

  3. Optical generation of radio-frequency power

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Vawter, G.A.; Brennan, T.M.; Hammons, B.E.; Meyer, W.J.

    1994-11-01

    An optical technique for high-power radio-frequency (RF) signal generation is described. The technique uses a unique photodetector based on a traveling-wave design driven by an appropriately modulated light source. The traveling-wave photodetector (TWPD) exhibits simultaneously a theoretical quantum efficiency approaching 100 % and a very large electrical bandwidth. Additionally, it is capable of dissipating the high-power levels required for the RF generation technique. The modulated light source is formed by either the beating together of two lasers or by the direct modulation of a light source. A system example is given which predicts RF power levels of 100`s of mW`s at millimeter wave frequencies with a theoretical ``wall-plug`` efficiency approaching 34%.

  4. Measurement techniques for radio frequency nanoelectronics

    CERN Document Server

    Wallis, T Mitch

    2017-01-01

    Connect basic theory with real-world applications with this practical, cross-disciplinary guide to radio frequency measurement of nanoscale devices and materials.• Learn the techniques needed for characterizing the performance of devices and their constituent building blocks, including semiconducting nanowires, graphene, and other two dimensional materials such as transition metal dichalcogenides• Gain practical insights into instrumentation, including on-wafer measurement platforms and scanning microwave microscopy• Discover how measurement techniques can be applied to solve real-world problems, in areas such as passive and active nanoelectronic devices, semiconductor dopant profiling, subsurface nanoscale tomography, nanoscale magnetic device engineering, and broadband, spatially localized measurements of biological materialsFeaturing numerous practical examples, and written in a concise yet rigorous style, this is the ideal resource for researchers, practicing engineers, and graduate students new to ...

  5. A novel radio frequency assisted heat pump dryer

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, M.G.; Metaxas, A.C.

    1999-09-01

    This paper compares an experimental heat pump batch dryer with the implementation of volumetric Radio Frequency (RF) heating, in the combination drying of crushed brick particulate. Results are presented showing overall improvements in drying. A simplified mathematical drying model including the RF energy source has been developed using mass and energy conservation, confirming the experimental results. Drying is a widespread, energy intensive industrial unit operation. The economics of a drying process operation largely depend upon the dryers performance and ultimately the cost of energy consumption. To enhance the performance of a drying system, the damp air stream that exits the drying chamber can be recycled to reclaim the enthalpy of evaporation that it carries, by using a heat pump (Hodgett, 1976). However, because the medium that dries is still warm air, this system also suffers from heat transfer limitations, particularly towards the falling drying rate period. Such limitations in drying performance can be overcome with the use of Radio Frequency (RF) energy which generates heat volumetrically within the wet material by the combined mechanisms of dipole rotation and conduction effects which speeds up the drying process (Metaxas et al, 1983). Despite the clear advantages that heat pumps and high frequency heating offer for drying, the combination of these two techniques until recently has not been studied (Kolly et al, 1990; Marshall et al, 1995).A series of experiments carried out comprising a motor driven heat pump which was retro-fitted with the ability of imparting RF energy into a material at various stages of the drying cycle are described and compared with a mathematical model.

  6. Radio frequency surface plasma oscillations: electrical excitation and detection by Ar/Ag(111).

    Science.gov (United States)

    Serrano, Giulia; Tebi, Stefano; Wiespointner-Baumgarthuber, Stefan; Müllegger, Stefan; Koch, Reinhold

    2017-08-29

    We electrically excite surface plasma oscillations on a Ag(111) single crystal by alternating electric charging at radio frequency. The radio frequency signal energy of 2.2 μeV, used to induce surface plasma oscillations, is about 5 to 6 orders of magnitude lower than the plasmon energies reachable by optical excitation or electron impact. The detection of the surface plasma oscillations is achieved by nano-fabricated 2D single-crystal sensor-islands of Ar atoms, which are shown by imaging with a scanning tunneling microscope to restructure in response to the radio frequency surface plasma oscillations, providing nanometer spatial resolution and a characteristic decay time of ≈150 ns.

  7. CERN Open Days 2013, Point 4: LHC Radio Frequency

    CERN Multimedia

    CERN Photolab

    2013-01-01

    Stand description: At Point 4 visitors will descend into the LHC tunnel to see the "engine" of the collider: the accelerating cavities where the circulating particles get a small kick of energy as they pass by 11,000 times each second. During your visit underground, you will see the superconducting magnets as well as instruments for observing the beams. You will also walk through the huge cavern containing the Radio Frequency power plants which provide the particle beams with energy. On surface no restricted access  Above ground, you will see the cryogenics installations which keep the accelerator at a just few degrees above absolute zero. Lots of fascinating information and exhibits about CERN's accelerators and experiments will be on display, with CERN engineers and physicists on hand all day to answer your questions.

  8. Effects of radio frequency identification-related radiation on in vitro biologics.

    Science.gov (United States)

    Uysal, Ismail; Hohberger, Clive; Rasmussen, R Scott; Ulrich, David A; Emond, Jean-Pierre; Gutierrez, Alfonso

    2012-01-01

    The recent developments on the use of e-pedigree to identify the chain of custody of drugs suggests the use of advanced track and trace technologies such as two-dimensional barcodes and radio frequency identification (RFID) tags. RFID technology is used mainly for valuable commodities such as pharmaceutical products while incorporating additional functionalities like monitoring environmental variables to ensure product safety and quality. In its guidance for the use of RFID technologies for drugs (Compliance Policy Guide Section 400.210), the Food and Drug Administration outlined multiple parameters that would apply to any study or application using RFID. However, drugs approved under a Biologics License Application or protein drugs covered by a New Drug Application were excluded mainly due to concerns about the effects of radio frequency radiation (thermal and/or non-thermal) on biologics. Even though the thermal effects of radio frequency on biologics are relatively well understood, there are few studies in the literature about the non-thermal effects of radio frequency with regards to the protein structure integrity. In this paper, we analyze the non-thermal effects of radio frequency radiation by exposing a wide variety of biologics including biopharmaceuticals with vaccines, hormones, and immunoglobulins, as well as cellular blood products such as red blood cells and whole blood-derived platelets as well as fresh frozen plasma. In order to represent the majority of the frequency spectrum used in RFID applications, five different frequencies (13.56 MHz, 433 MHz, 868 MHz, 915 MHz, and 2.4 GHz) are used to account for the most commonly used international frequency bands for RFID. With the help of specialized radio frequency signal-generating hardware, magnetic and electromagnetic fields are created around the exposed products with power levels greater than Federal Communications Commission-regulated limits. The in vitro test results on more than 100

  9. Influence of radio frequency power on structure and ionic ...

    Indian Academy of Sciences (India)

    Wintec

    Abstract. Lithium phosphorus oxynitride (LiPON) thin films as solid electrolytes were prepared by radio frequency magnetron sputtering of a Li3PO4 target in ambient nitrogen atmosphere. The influence of radio frequency (rf) power on the structure and the ionic conductivity of LiPON thin films has been investigated.

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

    African Journals Online (AJOL)

    This paper elucidates a radio frequency (RF) based transmission and reception system used to remotely monitor and control the water Level of an overhead tank placed up to 100 meters away from the pump and controller. It uses two Radio Frequency transceivers along with a controller each installed at the overhead tank ...

  11. 47 CFR 80.1019 - Antenna radio frequency indicator.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna radio frequency indicator. 80.1019 Section 80.1019 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO... Act § 80.1019 Antenna radio frequency indicator. Each nonportable bridge-to-bridge transmitter must be...

  12. K-Band Radio frequency Interference Survey of Southeastern Michigan

    DEFF Research Database (Denmark)

    Curry, Shannon; Ahlers, Michael Faursby; Elliot, Harvey

    2010-01-01

    The Radio frequency Interference Survey of Earth (RISE) is a new type of instrument used to survey and characterize the presence of Radio Frequency Interference (RFI) that can affect microwave radiometers. It consists of a combined microwave radiometer and kurtosis spectrometer with broad frequency...

  13. 47 CFR 80.927 - Antenna radio frequency indicator.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna radio frequency indicator. 80.927 Section 80.927 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO... Boats § 80.927 Antenna radio frequency indicator. The transmitter must be equipped with a device which...

  14. Influence of radio frequency power on structure and ionic ...

    Indian Academy of Sciences (India)

    Lithium phosphorus oxynitride (LiPON) thin films as solid electrolytes were prepared by radio frequency magnetron sputtering of a Li3PO4 target in ambient nitrogen atmosphere. The influence of radio frequency (rf) power on the structure and the ionic conductivity of LiPON thin films has been investigated. The morphology ...

  15. Radio-frequency ion deflector for mass separation

    Energy Technology Data Exchange (ETDEWEB)

    Schlösser, Magnus, E-mail: magnus.schloesser@googlemail.com; Rudnev, Vitaly; Ureña, Ángel González, E-mail: laseres@pluri.ucm.es [Unidad de Láseres y Haces Moleculares, Instituto Plurisdisciplinar, Universidad Complutense de Madrid, Madrid 28040 (Spain)

    2015-10-15

    Electrostatic cylindrical deflectors act as energy analyzer for ion beams. In this article, we present that by imposing of a radio-frequency modulation on the deflecting electric field, the ion transmission becomes mass dependent. By the choice of the appropriate frequency, amplitude, and phase, the deflector can be used as mass filter. The basic concept of the new instrument as well as simple mathematic relations are described. These calculations and further numerical simulations show that a mass sensitivity is achievable. Furthermore, we demonstrate the proof-of-principle in experimental measurements, compare the results to those of from a 1 m linear time-of-flight spectrometer, and comment on the mass resolution of the method. Finally, some potential applications are indicated.

  16. Comparative study on various radio frequency spectrum sensing techniques

    Science.gov (United States)

    Gondesi, Raveendhar Reddy

    2011-12-01

    Cognitive radio (CR) is a self-monitoring wireless communication system. CR can utilize the radio frequency spectrum efficiently. The main objective of cognitive radio is to detect the primary user signal and determine whether a channel is free or not. The CR user can opportunistically use those idle spectrum bands without causing harmful interference to the licensed/primary users. There are several spectrum sensing techniques which can serve this purpose. In this research, the computational complexities for different local spectrum sensing techniques are calculated. Using the results obtained from computational complexities, the energy efficient and time efficient techniques are determined. From the results obtained in local sensing techniques, the cost efficient and bandwidth efficient combination for cooperative spectrum sensing is determined. Using MATLAB programming, the receiver operating characteristic curves for these spectrum sensing techniques are plotted.

  17. A Monte Carlo Method for Low Pressure Radio Frequency Discharges

    Directory of Open Access Journals (Sweden)

    Lahouaria Settaouti

    2003-06-01

    Full Text Available There is increasing interest in glow discharges because of their importance to a large number of application fields, like the microelectronics industry, flat plasma display panel technology, the laser and light industry and analytical spectrochemistry. To improve the capabilities of rf glow discharges, a good understanding of the discharge physics is highly desirable. The typical calculated results include the radio frequency (rf voltage, the electrical field distribution, the density of argon ions and electrons, the electron energy distribution function and information about the collision processes of the electrons with the Monte Carlo model. These results are presented throughout the discharge axis and as a function of time in the rf cycle. Moreover, we have investigated how many rf cycles have to be followed before a periodic steady state is reached.

  18. Monitoring Radio Frequency Interference in Southwest Virginia

    Science.gov (United States)

    Rapp, Steve

    2010-01-01

    The radio signals received from astronomical objects are extremely weak. Because of this, radio sources are easily shrouded by interference from devices such as satellites and cell phone towers. Radio astronomy is very susceptible to this radio frequency interference (RFI). Possibly even worse than complete veiling, weaker interfering signals can contaminate the data collected by radio telescopes, possibly leading astronomers to mistaken interpretations. To help promote student awareness of the connection between radio astronomy and RFI, an inquiry-based science curriculum was developed to allow high school students to determine RFI levels in their communities. The Quiet Skies Project_the result of a collaboration between the National Aeronautics and Space Administration (NASA), the National Science Foundation (NSF), and the National Radio Astronomy Observatory (NRAO)_encourages students to collect and analyze RFI data and develop conclusions as a team. Because the project focuses on electromagnetic radiation, it is appropriate for physics, physical science, chemistry, or general science classes. My class-about 50 students from 15 southwest Virginia high schools-participated in the Quiet Skies Project and were pioneers in the use of the beta version of the Quiet Skies Detector (QSD), which is used to detect RFI. Students have been involved with the project since 2005 and have collected and shared data with NRAO. In analyzing the data they have noted some trends in RFI in Southwest Virginia.

  19. Filamentation of a Magnetized, Radio Frequency Discharge

    Science.gov (United States)

    Konopka, Uwe; Lynch, Brian; Bandyopadhyay, Pintu; Sharma, Devendra; Thomas, Edward

    2014-10-01

    A filamentation instability has been observed in a radio-frequency (rf) discharge that was subject to an externally applied, homogeneous magnetic field. The instability arises in a uniform rf-discharge after the magnetic field strength is sufficiently increased. First, the plasma shows target-like glow structures, followed by spiral structures at higher fields. Finally, the plasma breaks up into individual, string-like, magnetic field aligned filaments that seem to repel each other. A variety of filamentation states can be observed, but their overall shapes follow the aforementioned rule of magnetic field strength dependency. The detailed picture of the discharge glow, however, depends on experiment specific conditions as the geometric shape and type of the discharge electrodes, the discharge pressure and power. In an effort to verify that the observed effect is universal, we compare experimental measurements made using two different high magnetic field, dusty plasma experiment facilities: the experiment that was located at the Max Planck Institute in Garching, Germany and the newly built MDPX (magnetized dusty plasma experiment) at Auburn University, Alabama. In both experimental setups we could observe filamentation. This work is supported from funding from DOE and NSF.

  20. Ultracold atoms in multiple radio-frequency dressed adiabatic potentials

    Science.gov (United States)

    Harte, T. L.; Bentine, E.; Luksch, K.; Barker, A. J.; Trypogeorgos, D.; Yuen, B.; Foot, C. J.

    2018-01-01

    We present the first experimental demonstration of a multiple radio-frequency dressed potential for the configurable magnetic confinement of ultracold atoms. We load cold 87Rb atoms into a double-well potential with an adjustable barrier height, formed by three radio-frequencies applied to atoms in a static quadrupole magnetic field. Our multiple radio-frequency approach gives precise control over the double-well characteristics, including the depth of individual wells and the height of the barrier, and enables reliable transfer of atoms between the available trapping geometries. We characterize the multiple radio-frequency dressed system using radio-frequency spectroscopy, finding good agreement with the eigenvalues numerically calculated using Floquet theory. This method creates trapping potentials that can be reconfigured by changing the amplitudes, polarizations, and frequencies of the applied dressing fields and easily extended with additional dressing frequencies.

  1. Dielectric properties of almond shells in the development of radio frequency and microwave pasteurization

    Science.gov (United States)

    To develop pasteurization treatments based on radio frequency (RF) or microwave energy, dielectric properties of almond shells were determined using an open-ended coaxial-probe with an impedance analyzer over a frequency range of 10 to 1800 MHz. Both the dielectric constant and loss factor of almond...

  2. Oncologic Efficacy of Radio Frequency Ablation for Small Renal Masses: Clear Cell vs Papillary Subtype.

    Science.gov (United States)

    Lay, Aaron H; Faddegon, Stephen; Olweny, Ephrem O; Morgan, Monica; Lorber, Gideon; Trimmer, Clayton; Leveillee, Raymond; Cadeddu, Jeffrey A; Gahan, Jeffrey C

    2015-09-01

    Current radio frequency ablation series do not distinguish renal cell carcinoma subtypes when reporting oncologic efficacy. Papillary neoplasms may be more amenable to radio frequency ablation than clear cell carcinoma because they are less vascular, which may limit heat energy loss. We report the long-term outcomes of patients treated with radio frequency ablation for small renal masses by renal cell carcinoma subtype. The records of patients undergoing radio frequency ablation for small renal masses (cT1a) at 2 institutions from March 2007 to July 2012 were retrospectively reviewed. Patients were included in analysis if they had biopsy confirmed clear cell or papillary renal cell carcinoma histology. Patients had at least 1 contrast enhanced cross-sectional image following radio frequency ablation. Demographic data between tumor subtypes were compared using the paired t-test. Oncologic outcomes were determined by Kaplan-Meier survival analysis and survivor curves were compared with the log rank test. A total of 229 patients met study inclusion criteria. There were 181 clear cell tumors and 48 papillary tumors. Median followup was 33.2 months. There was no difference between tumor groups based on patient age, tumor size or grade, or months of followup. Five-year disease-free survival was 89.7% for clear cell tumors and 100% for papillary tumors (p = 0.041). There was no significant difference in overall survival (88.4% vs 89.6%, p = 0.764). Radio frequency ablation outcomes seem to be determined in part by renal cell carcinoma subtype with clear cell renal tumors having less favorable outcomes. We hypothesize that this is due to differences in tumor vascularity. Our experience suggests that future tumor ablation studies should consider reporting outcomes based on tumor cell types. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  3. Optical Tunable-Based Transmitter for Multiple Radio Frequency Bands

    Science.gov (United States)

    Nguyen, Hung (Inventor); Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor); Freeman, Jon C. (Inventor)

    2016-01-01

    An optical tunable transmitter is used to transmit multiple radio frequency bands on a single beam. More specifically, a tunable laser is configured to generate a plurality of optical wavelengths, and an optical tunable transmitter is configured to modulate each of the plurality of optical wavelengths with a corresponding radio frequency band. The optical tunable transmitter is also configured to encode each of the plurality of modulated optical wavelengths onto a single laser beam for transmission of a plurality of radio frequency bands using the single laser beam.

  4. 77 FR 35426 - Certain Radio Frequency Integrated Circuits and Devices Containing Same; Institution of...

    Science.gov (United States)

    2012-06-13

    ... COMMISSION Certain Radio Frequency Integrated Circuits and Devices Containing Same; Institution of... within the United States after importation of certain radio frequency integrated circuits and devices... after importation of certain radio frequency integrated circuits and devices containing same that...

  5. 78 FR 19311 - Certain Radio Frequency Identification (“RFID”) Products And Components Thereof; Institution of...

    Science.gov (United States)

    2013-03-29

    ... COMMISSION Certain Radio Frequency Identification (``RFID'') Products And Components Thereof; Institution of... importation, and the sale within the United States after importation of certain radio frequency identification... sale within the United States after importation of certain radio frequency identification (``RFID...

  6. Radio Frequency Micro Ion Thruster for Precision Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to continue development of an engineering model radio frequency discharge, gridded micro ion thruster that produces sub-mN to mN thrust precisely...

  7. Radio Frequency Micro Ion Thruster for Precision Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to develop radio frequency discharge, gridded micro-ion thruster that produces sub-mN thrust precisely adjustable over a wide dynamic thrust range....

  8. 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.

  9. Harmonic Phase Responses of Radio Frequency Electronics: Wireline Test

    Science.gov (United States)

    2015-12-01

    ARL-TR-7552 ● DEC 2015 US Army Research Laboratory Harmonic Phase Responses of Radio Frequency Electronics: Wireline Test by...DEC 2015 US Army Research Laboratory Harmonic Phase Responses of Radio Frequency Electronics: Wireline Test by Gregory J Mazzaro, Sean F...DD-MM-YYYY) December 2015 2. REPORT TYPE Final 3. DATES COVERED (From - To) 08/2015 4. TITLE AND SUBTITLE Harmonic Phase Responses of Radio

  10. Photonic radio frequency phase-shift amplification by radio frequency interferometry.

    Science.gov (United States)

    Ayun, Moshe Ben; Schwarzbaum, Arye; Rosenberg, Seva; Pinchas, Monika; Sternklar, Shmuel

    2015-11-01

    We present a new technique for radio frequency (RF) phase-shift amplification based on RF interferometry and demonstrate it in an optical system. A striking feature of this amplifier is that the input phase noise is not amplified together with the input phase signal, so the phase sensitivity improves with higher phase amplification. We also predict that in the case of correlated amplitude noise, the sensitivity is not affected by the amplitude noise. With 600 MHz of modulated light and a phase amplification of 100, we demonstrate a phase resolution of 0.2 mrad, giving a distance resolution of 8 μm. We postulate that nanometric distance resolution can be achieved with sub-gigahertz modulation.

  11. Electrokinetic actuation of liquid metal for reconfigurable radio frequency devices

    Science.gov (United States)

    Gough, Ryan C.

    Liquid metals are an attractive material choice for designers wishing to combine the advantages of metals, such as high electrical conductivity, thermal conductivity, and reflectivity, with the inherently dynamic nature of fluids. Liquid metals have been utilized for a wide variety of applications, but their high electrical conductivity, surface smoothness, and linear response makes them especially attractive as tuning elements within reconfigurable radio frequency (RF) devices. The recent introduction of non-toxic liquid metal alloys onto the commercial market has further fueled interest in this versatile material. Early experiments with liquid metal as an RF tuning element have yielded promising results, but have largely depended on externally applied pressure to actuate the liquid metal. For commercial implementation this would necessitate the use of clunky and inefficient micro-pumps, which can require both high voltages and high power consumption. This reliance on hydraulic pumping has been a significant barrier to the incorporation of liquid metal as an RF tuning element in applications outside of a laboratory setting. Here, several electrical actuation techniques are demonstrated that allow for the rapid and repeatable actuation of non-toxic gallium alloys as tuning elements within reconfigurable RF devices. These techniques leverage the naturally high surface tension of liquid metals, as well as the unique electrochemistry of gallium-based alloys, to exercise wide-ranging and high fidelity control over both the metal's shape and position. Furthermore, this control is exercised with voltage and power levels that are each better than an order of magnitude below that achievable with conventional micro-pumps. This control does not require the constant application of actuation signals in order to maintain an actuated state, and can even be 'self-actuated', with the liquid metal supplying its own kinetic energy via the electrochemical conversion of its native

  12. Gold Nanoparticles and Radio Frequency Field Interactions: Effects of Nanoparticle Size, Charge, Aggregation, Radio Frequency, and Ionic Background.

    Science.gov (United States)

    Mironava, Tatsiana; Arachchilage, Visal T; Myers, Kenneth J; Suchalkin, Sergey

    2017-11-14

    In this study, we investigated experimentally the dependency of radio frequency (rf) absorption by gold nanoparticles (AuNPs) on frequency (10 kHz to 450 MHz), NP size (3.5, 17, and 36 nm), charge of the ligand shell (positive amino and negative carboxylic functional groups), aggregation state, and presence of electrolytes (0-1 M NaCl). In addition, we examined the effect of protein corona on the rf absorption by AuNPs. For the first time, rf energy absorption by AuNPs was analyzed in the 10 kHz to 450 MHz rf range. We have demonstrated that the previously reported rf heating of AuNPs can be solely attributed to the heating of the ionic background and AuNPs do not absorb noticeable rf energy regardless of the NP size, charge, aggregation, and presence of electrolytes. However, the formation of protein corona on the AuNP surface resulted in rf energy absorption by AuNP-albumin constructs, suggesting that protein corona might be partially responsible for the heating of AuNPs observed in vivo. The optimal frequency of rf absorption for the AuNP-albumin constructs is significantly higher than conventional 13.56 MHz, suggesting that the heating of AuNPs in rf field should be performed at considerably higher frequencies for better results in vivo.

  13. The design of a radio frequency quadrupole LINAC for the RIB ...

    Indian Academy of Sciences (India)

    2The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Saitama 351-0198, Japan. £Email: vaishali@veccal.ernet.in. Abstract. A radio frequency quadrupole LINAC has been designed for the VECC-RIB project for an input beam energy of 1.0 keV/u and q A. 1 16. The output energy will be about 90 keV/u ...

  14. Report on GMI Special Study #15: Radio Frequency Interference

    Science.gov (United States)

    Draper, David W.

    2015-01-01

    This report contains the results of GMI special study #15. An analysis is conducted to identify sources of radio frequency interference (RFI) to the Global Precipitation Measurement (GPM) Microwave Imager (GMI). The RFI impacts the 10 GHz and 18 GHz channels at both polarities. The sources of RFI are identified for the following conditions: over the water (including major inland water bodies) in the earth view, and over land in the earth view, and in the cold sky view. A best effort is made to identify RFI sources in coastal regions, with noted degradation of flagging performance due to the highly variable earth scene over coastal regions. A database is developed of such sources, including latitude, longitude, country and city of earth emitters, and position in geosynchronous orbit for space emitters. A description of the recommended approach for identifying the sources and locations of RFI in the GMI channels is given in this paper. An algorithm to flag RFI contaminated pixels which can be incorporated into the GMI Level 1Base/1B algorithms is defined, which includes Matlab code to perform the necessary flagging of RFI. A Matlab version of the code is delivered with this distribution.

  15. Radio frequency identification enabled wireless sensing for intelligent food logistics.

    Science.gov (United States)

    Zou, Zhuo; Chen, Qiang; Chen, Qing; Uysal, Ismail; Zheng, Lirong

    2014-06-13

    Future technologies and applications for the Internet of Things (IoT) will evolve the process of the food supply chain and create added value of business. Radio frequency identifications (RFIDs) and wireless sensor networks (WSNs) have been considered as the key technological enablers. Intelligent tags, powered by autonomous energy, are attached on objects, networked by short-range wireless links, allowing the physical parameters such as temperatures and humidities as well as the location information to seamlessly integrate with the enterprise information system over the Internet. In this paper, challenges, considerations and design examples are reviewed from system, implementation and application perspectives, particularly with focus on intelligent packaging and logistics for the fresh food tracking and monitoring service. An IoT platform with a two-layer network architecture is introduced consisting of an asymmetric tag-reader link (RFID layer) and an ad-hoc link between readers (WSN layer), which are further connected to the Internet via cellular or Wi-Fi. Then, we provide insights into the enabling technology of RFID with sensing capabilities. Passive, semi-passive and active RFID solutions are discussed. In particular, we describe ultra-wideband radio RFID which has been considered as one of the most promising techniques for ultra-low-power and low-cost wireless sensing. Finally, an example is provided in the form of an application in fresh food tracking services and corresponding field testing results.

  16. Compact Superconducting Radio-frequency Accelerators and Innovative RF Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kephart, Robert [Fermilab; Chattopadhyay, Swaapan [Northern Illinois U.; Milton, Stephen [Colorado State U.

    2015-04-10

    We will present several new technical and design breakthroughs that enable the creation of a new class of compact linear electron accelerators for industrial purposes. Use of Superconducting Radio-Frequency (SRF) cavities allow accelerators less than 1.5 M in length to create electron beams beyond 10 MeV and with average beam powers measured in 10’s of KW. These machines can have the capability to vary the output energy dynamically to produce brehmstrahlung x-rays of varying spectral coverage for applications such as rapid scanning of moving cargo for security purposes. Such compact accelerators will also be cost effective for many existing and new industrial applications. Examples include radiation crosslinking of plastics and rubbers, creation of pure materials with surface properties radically altered from the bulk, modification of bulk or surface optical properties of materials, sterilization of medical instruments animal solid or liquid waste, and destruction of organic compounds in industrial waste water effluents. Small enough to be located on a mobile platform, such accelerators will enable new remediation methods for chemical and biological spills and/or in-situ crosslinking of materials. We will describe one current design under development at Fermilab including plans for prototype and value-engineering to reduce costs. We will also describe development of new nano-structured field-emitter arrays as sources of electrons, new methods for fabricating and cooling superconducting RF cavities, and a new novel RF power source based on magnetrons with full phase and amplitude control.

  17. A graphical approach to radio frequency quadrupole design

    Science.gov (United States)

    Turemen, G.; Unel, G.; Yasatekin, B.

    2015-07-01

    The design of a radio frequency quadrupole, an important section of all ion accelerators, and the calculation of its beam dynamics properties can be achieved using the existing computational tools. These programs, originally designed in 1980s, show effects of aging in their user interfaces and in their output. The authors believe there is room for improvement in both design techniques using a graphical approach and in the amount of analytical calculations before going into CPU burning finite element analysis techniques. Additionally an emphasis on the graphical method of controlling the evolution of the relevant parameters using the drag-to-change paradigm is bound to be beneficial to the designer. A computer code, named DEMIRCI, has been written in C++ to demonstrate these ideas. This tool has been used in the design of Turkish Atomic Energy Authority (TAEK)'s 1.5 MeV proton beamline at Saraykoy Nuclear Research and Training Center (SANAEM). DEMIRCI starts with a simple analytical model, calculates the RFQ behavior and produces 3D design files that can be fed to a milling machine. The paper discusses the experience gained during design process of SANAEM Project Prometheus (SPP) RFQ and underlines some of DEMIRCI's capabilities.

  18. Radio frequency glow discharge-induced acidification of fluoropolymers.

    Science.gov (United States)

    Krawczyk, Benjamin M; Baltrusaitis, Jonas; Yoder, Colin M; Vargo, Terrence G; Bowden, Ned B; Kader, Khalid N

    2011-12-01

    Fluoropolymer surfaces are unique in view of the fact that they are quite inert, have low surface energies, and possess high thermal stabilities. Attempts to modify fluoropolymer surfaces have met with difficulties in that it is difficult to control the modification to maintain bulk characteristics of the polymer. In a previously described method, the replacement of a small fraction of surface fluorine by acid groups through radio frequency glow discharge created a surface with unexpected reactivity allowing for attachment of proteins in their active states. The present study demonstrates that 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) reacts with the acid groups on fluoropolymer surfaces in a novel reaction not previously described. This reaction yields an excellent leaving group in which a primary amine on proteins can substitute to form a covalent bond between a protein and these surfaces. In an earlier study, we demonstrated that collagen IV could be deposited on a modified PTFE surface using EDC as a linker. Once collagen IV is attached to the surface, it assembles to form a functional stratum resembling collagen IV in native basement membrane. In this study, we show data suggesting that the fluorine to carbon ratio determines the acidity of the fluoropolymer surfaces and how well collagen IV attaches to and assembles on four different fluoropolymer surfaces. Copyright © 2011 Wiley Periodicals, Inc.

  19. Hydrodynamic and kinetic modelling of complex radio-frequency plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Goedheer, W J; Venema, J [FOM Institute for Plasma Physics ' Rijnhuizen' , Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Land, V, E-mail: W.J.Goedheer@rijnhuizen.n [Center for Astrophysics, Space Physics and Engineering Research, Baylor University, Waco, TX 76798 (United States)

    2009-10-07

    In this paper hydrodynamic and kinetic approaches to model low-pressure capacitively coupled complex radio-frequency discharges are discussed and applied to discharges under micro-gravity. Complex plasmas contain dust grains with a large negative charge and are characterized by a strong coupling between the properties of the plasma and those of the dust grains. After a discussion of the physics and methods involved, examples are presented from modelling of experiments under micro-gravity in the PKE-Nefedov reactor on board the International Space Station. These discharges are simulated with a 2D cylindrically symmetric hydrodynamic model. Kinetic effects are studied with a 1D particle-in-cell plus Monte Carlo model in which capture and scattering by dust grains is included. Since experiments are often performed at low pressures, the electron energy distribution function is no longer determined by the local plasma properties. This has consequences for the charging of the dust. Results of simulations with this model are compared with the hydrodynamic results. In addition, we address the behaviour of the dust charge in decaying plasmas.

  20. Magnetoreception in birds: the effect of radio-frequency fields.

    Science.gov (United States)

    Wiltschko, Roswitha; Thalau, Peter; Gehring, Dennis; Nießner, Christine; Ritz, Thorsten; Wiltschko, Wolfgang

    2015-02-06

    The avian magnetic compass, probably based on radical pair processes, works only in a narrow functional window around the local field strength, with cryptochrome 1a as most likely receptor molecule. Radio-frequency fields in the MHz range have been shown to disrupt the birds' orientation, yet the nature of this interference is still unclear. In an immuno-histological study, we tested whether the radio-frequency fields interfere with the photoreduction of cryptochrome, but this does not seem to be the case. In behavioural studies, birds were not able to adjust to radio-frequency fields like they are able to adjust to static fields outside the normal functional range: neither a 2-h pre-exposure in a 7.0 MHz field, 480 nT, nor a 7-h pre-exposure in a 1.315 MHz field, 15 nT, allowed the birds to regain their orientation ability. This inability to adjust to radio-frequency fields suggests that these fields interfere directly with the primary processes of magnetoreception and therefore disable the avian compass as long as they are present. They do not have lasting adverse after-effects, however, as birds immediately after exposure to a radio-frequency field were able to orient in the local geomagnetic field. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  1. Personal exposure to radio frequency electromagnetic fields and implications for health

    OpenAIRE

    Frei, Patrizia

    2010-01-01

    Exposure to radio frequency electromagnetic fields (RF-EMFs), as produced by mobile phone base stations, broadcast transmitters and cordless phones, has considerably increased over the past 20 years, especially due to the rapid expansion of the mobile phone communication network. Little is known about typical RF-EMF exposure levels and the spatial and temporal variability of RF-EMFs in our environment. Moreover, the contribution of the various exposure sources to total exposure has not been q...

  2. Immunity of electronic devices against radio-frequency electromagnetic fields

    Directory of Open Access Journals (Sweden)

    Urbancokova Hana

    2017-01-01

    Full Text Available One of the major types of electromagnetic interference, which affect electronic devices in their normal operation, is the interference with radio-frequency electromagnetic fields. This interference is generated by the mainly radio and television transmitters, industrial equipment and other transmitters and receivers in general use for communication. Testing of electromagnetic susceptibility of electronic devices on radiated radio-frequency electromagnetic field is governed by the basic standard IEC 61000-4-3 and the equipment under test are exposed to test electromagnetic fields with an intensity from 1 V/m to 30 V/m, the most often in the frequency range from 80 MHz to 2 GHz. The aim of this paper is to explain the issue of electromagnetic susceptibility and to present sample the electromagnetic immunity tests of the basic set of the intrusion and hold-up alarm system against the radio-frequency electromagnetic field according to the relevant electromagnetic compatibility standards.

  3. Methods, Systems and Apparatuses for Radio Frequency Identification

    Science.gov (United States)

    Fink, Patrick W. (Inventor); Chu, Andrew W. (Inventor); Lin, Gregory Y. (Inventor); Kennedy, Timothy F. (Inventor); Ngo, Phong H. (Inventor); Brown, Dewey T. (Inventor); Byerly, Diane (Inventor)

    2017-01-01

    A system for radio frequency identification (RFID) includes an enclosure defining an interior region interior to the enclosure, and a feed for generating an electromagnetic field in the interior region in response to a signal received from an RFID reader via a radio frequency (RF) transmission line and, in response to the electromagnetic field, receiving a signal from an RFID sensor attached to an item in the interior region. The structure of the enclosure may be conductive and may include a metamaterial portion, an electromagnetically absorbing portion, or a wall extending in the interior region. Related apparatuses and methods for performing RFID are provided.

  4. Electrical characteristics for capacitively coupled radio frequency ...

    Indian Academy of Sciences (India)

    MURAT TANISLI

    2017-08-16

    Aug 16, 2017 ... plasma forms an environment which is free of charged particles moving in random directions [1,2]. ... RF-Generator Navio Matching Network used for sta- ble current and voltage values. This device has been .... the gas gain energy from the RF electric field. When He gas and Ne gas at 0.05 l/min flow rate ...

  5. UTag: Long-range Ultra-wideband Passive Radio Frequency Tags

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, F

    2007-03-14

    Long-range, ultra-wideband (UWB), passive radio frequency (RF) tags are key components in Radio Frequency IDentification (RFID) system that will revolutionize inventory control and tracking applications. Unlike conventional, battery-operated (active) RFID tags, LLNL's small UWB tags, called 'UTag', operate at long range (up to 20 meters) in harsh, cluttered environments. Because they are battery-less (that is, passive), they have practically infinite lifetimes without human intervention, and they are lower in cost to manufacture and maintain than active RFID tags. These robust, energy-efficient passive tags are remotely powered by UWB radio signals, which are much more difficult to detect, intercept, and jam than conventional narrowband frequencies. The features of long range, battery-less, and low cost give UTag significant advantage over other existing RFID tags.

  6. Achieving low-emissivity materials with high transmission for broadband radio-frequency signals.

    Science.gov (United States)

    Liu, Liu; Chang, Huiting; Xu, Tao; Song, Yanan; Zhang, Chi; Hang, Zhi Hong; Hu, Xinhua

    2017-07-07

    The use of low-emissivity (low-e) materials in modern buildings is an extremely efficient way to save energy. However, such materials are coated by metallic films, which can strongly block radio-frequency signals and prevent indoor-outdoor wireless communication. Here, we demonstrate that, when specially-designed metallic metasurfaces are covered on them, the low-e materials can remain low emissivity for thermal radiation and allow very high transmission for a broad band of radio-frequency signals. It is found that the application of air-connected metasurfaces with subwavelength periods is critical to the observed high transmission. Such effects disappear if periods are comparable to wavelengths or metal-connected structures are utilized. The conclusion is supported by both simulations and experiments. Advantages such as easy to process, low cost, large-area fabrication and design versatility of the metasurface make it a promising candidate to solve the indoor outdoor communication problem.

  7. Deposition rate in modulated radio-frequency silane plasmas

    NARCIS (Netherlands)

    A.C.W. Biebericher,; Bezemer, J.; W.F. van der Weg,; W. J. Goedheer,

    2000-01-01

    Plasma-enhanced chemical-vapor deposition of amorphous silicon by a square-wave amplitude-modulated radio-frequency excitation has been studied by optical emission spectroscopy and plasma modeling. By the modulation, the deposition rate is increased or reduced, depending on the plasma parameters.

  8. Switched-RC radio frequency N-path filters

    NARCIS (Netherlands)

    Ghaffari, A.

    2013-01-01

    Tunable on-chip Radio Frequency (RF) filtering is highly desirable for cost effective wireless communication devices. As mobile wireless devices increasingly support multiple RF-bands, tunable RF filtering is wanted. The tremendous growth of wireless communication combined with scarcely available

  9. 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.

  10. Topology optimization of radio frequency and microwave structures

    DEFF Research Database (Denmark)

    Aage, Niels

    This thesis focuses on topology optimization of conductor-based microwave and radio frequency electromagnetic devices. The research is motivated by the ever increasing usage of small hand-held, or autonomous, electric devices, which have lead to a series of new challenges for the design...

  11. The regulatory framework of the radio frequency spectrum under ...

    African Journals Online (AJOL)

    The Radio Frequency Spectrum (R.F.S) is the entire range of wavelengths of electromagnetic radiation in the frequency range of 3 kilohertz (KHZ) to 40,000 megahertz (MHZ). The RFS is arbitrarily divided into a number of wavebands, from very low frequencies (long wavelengths) to ultra-high and microwave frequencies ...

  12. 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…

  13. H- radio frequency source development at the Spallation Neutron Sourcea)

    Science.gov (United States)

    Welton, R. F.; Dudnikov, V. G.; Gawne, K. R.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Roseberry, R. T.; Santana, M.; Stockli, M. P.; Turvey, M. W.

    2012-02-01

    The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent ˜38 mA peak current in the linac and an availability of ˜90%. H- beam pulses (˜1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, ˜60 kW) of a copper antenna that has been encased with a thickness of ˜0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of ˜99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of ˜75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to ˜100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

  14. Improving AMS Detection of the Biomedical Radiotracer 41Ca with Segmented Radio-Frequency Quadrupoles

    Science.gov (United States)

    Alary, Jean-Francois; Javahery, Gholamreza; Kieser, William E.; Litherland, Albert E.; Cousins, Lisa M.

    41Ca is an important biomedical radiotracer finding many applications in biological, nutritional and medical studies. The detection of 41Ca by AMS is however limited by an important background signal of 41K originating from biological samples and from contaminated cesium in the source. An approach consisting of using PbF2-assisted in-source fluorination in combination with an Isobar Separator for Anions (ISA), a device incorporating a low energy radio frequency quadrupole (RFQ) gas cell, promises to push down the limit of detection of 41Ca attainable on small (biological sample preparation and less concern about variable 41K contamination of the cesium beam. The selective collision-induced fragmentation of KF3- versus CaF3-, occurring in the gas cell of an ISA equipped with a double segment RFQ, have been reported earlier1), leading to K being suppressed by a factor of 1e4 over Ca. We present here the future configuration of the ISA, redesigned using multi-segmented RFQ to enhance further this effect and improve transmission through the gas cell. A segmented RFQ is an appropriate tool to finely control ion energy down to the few eV's separating the fragmentation energies of the two fluoride species. This pre-commercial ISA destined to be used at the newly established A. E. Lalonde AMS laboratory at University of Ottawa (Canada) will be presented. Some practicalities of integrating a low energy RFQ-based device in a high energy AMS system will also be discussed.

  15. 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

    2009-01-01

    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. PMID:20144364

  16. Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Mastoridis, Themistoklis [Stanford Univ., CA (United States)

    2010-08-01

    The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC

  17. Radio Frequency Interference Suppression for Landmine Detection by Quadrupole Resonance

    Directory of Open Access Journals (Sweden)

    Liu Guoqing

    2006-01-01

    Full Text Available The quadrupole resonance (QR technology can be used as a confirming sensor for buried plastic landmine detection by detecting the explosives within the mine. We focus herein on the detection of TNT mines via the QR sensor. Since the frequency of the QR signal is located within the AM radio frequency band, the QR signal can be corrupted by strong radio frequency interferences (RFIs. Hence to detect the very weak QR signal, RFI mitigation is essential. Reference antennas, which receive RFIs only, can be used together with the main antenna, which receives both the QR signal and the RFIs, for RFI mitigation. The RFIs are usually colored both spatially and temporally, and hence exploiting only the spatial diversity of the antenna array may not give the best performance. We exploit herein both the spatial and temporal correlations of the RFIs to improve the TNT detection performance.

  18. Simple Stabilized Radio-Frequency Transfer With Optical Phase Actuation

    Science.gov (United States)

    Gozzard, David R.; Schediwy, Sascha W.; Courtney-Barrer, Benjamin; Whitaker, Richard; Grainge, Keith

    2018-02-01

    We describe and experimentally evaluate a stabilized radio-frequency transfer technique that employs optical phase sensing and optical phase actuation. This technique can be achieved by modifying existing stabilized optical frequency equipment and also exhibits advantages over previous stabilized radio-frequency transfer techniques in terms of size and complexity. We demonstrate the stabilized transfer of a 160 MHz signal over an 166 km fiber optical link, achieving an Allan deviation of 9.7x10^-12 Hz/Hz at 1 s of integration, and 3.9x10^-1414 Hz/Hz at 1000 s. This technique is being considered for application to the Square Kilometre Array SKA1-low radio telescope.

  19. Stable radio frequency dissemination by simple hybrid frequency modulation scheme.

    Science.gov (United States)

    Yu, Longqiang; Wang, Rong; Lu, Lin; Zhu, Yong; Wu, Chuanxin; Zhang, Baofu; Wang, Peizhang

    2014-09-15

    In this Letter, we propose a fiber-based stable radio frequency transfer system by a hybrid frequency modulation scheme. Creatively, two radio frequency signals are combined and simultaneously transferred by only one laser diode. One frequency component is used to detect the phase fluctuation, and the other one is the derivative compensated signal providing a stable frequency for the remote end. A proper ratio of the frequencies of the components is well maintained by parameter m to avoid interference between them. Experimentally, a stable 200 MHz signal is transferred over 100 km optical fiber with the help of a 1 GHz detecting signal, and fractional instability of 2×10(-17) at 10(5) s is achieved.

  20. 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.

  1. Radio frequency identification and its application in e-commerce

    OpenAIRE

    Bahr, Witold; Price, Brian J

    2016-01-01

    This chapter presents Radio Frequency Identification (RFID), which is one of the Automatic Identification and Data Capture (AIDC) technologies (Wamba and Boeck, 2008) and discusses the application of RFID in E-Commerce. Firstly RFID is defined and the tag and reader components of the RFID system are explained. Then historical context of RFID is briefly discussed. Next, RFID is contrasted with other AIDC technologies, especially the use of barcodes which are commonly applied in E-Commerce. Las...

  2. Rectification of radio frequency current in ferromagnetic nanowire

    OpenAIRE

    Yamaguchi, A.; Miyajima, H.; Ono, T.; Suzuki, Y.; Yuasa, S.; Tulapurkar, A.; Nakatani, Y.

    2006-01-01

    We report the rectification of a constant wave radio frequency (RF) current by using a single-layer magnetic nanowire; a direct-current voltage is resonantly generated when the RF current flows through the nanowire. The mechanism of the rectification is discussed in terms of the spin torque diode effect reported for magnetic tunnel junction devices and the rectification is shown to be direct attributable to resonant spin wave excitation by the RF current.

  3. INTEGRATING RADIO FREQUENCY IDENTIFICATION TECHNOLOGY IN ACADEMIC MANAGEMENT SYSTEM

    OpenAIRE

    Zainab Rasheed Mirza; M. Nawaz Brohi

    2014-01-01

    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 a...

  4. Design of a 6-bit CMOS digital radio frequency memory

    Science.gov (United States)

    Kranz, Gordon M.; Mehalic, Mark

    The authors describe the implementation of a digital radio frequency memory (DRFM) on a single integrated circuit. A VHSIC Hardware Description Language (VHDL) model of the DRFM was completed and used to design the VLSI components of the DRFM architecture. The model performed the specified time and frequency shift functions. A DRFM, with a 1K memory, a control unit, and a digital single-sideband modulator (DSSM) has been placed onto a silicon single chip layout design.

  5. Radio Frequency Identification (RFID): its usage and libraries

    OpenAIRE

    Rafiq, Muhammad

    2004-01-01

    Radio Frequency Identification (RFID) is one of the most exciting technologies that revolutionize the working practices by increasing efficiencies, and improving profitability. The article provides details about RFID, its components, how it works, and its usage in different sectors i.e. retail sales and supply chains, livestock industry, courier services, military and prisons, automobiles and logistics, entertainment industry, publishing industry, wireless transaction, and, especially, in...

  6. Scattering of radio frequency waves by turbulence in fusion plasmas

    Science.gov (United States)

    Ram, Abhay K.

    2016-10-01

    In tokamak fusion plasmas, coherent fluctuations in the form of blobs or filaments and incoherent fluctuations due to turbulence are routinely observed in the scrape-off layer. Radio frequency (RF) electromagnetic waves, excited by antenna structures placed near the wall of a tokamak, have to propagate through the scrape-off layer before reaching the core of the plasma. While the effect of fluctuations on RF waves has not been quantified experimentally, there are telltale signs, arising from differences between results from simulations and from experiments, that fluctuations can modify the spectrum of RF waves. Any effect on RF waves in the scrape-off layer can have important experimental consequences. For example, electron cyclotron waves are expected to stabilize the deleterious neoclassical tearing mode (NTM) in ITER. Spectral and polarization changes due to scattering will modify the spatial location and profile of the current driven by the RF waves, thereby affecting the control of NTMs. Pioneering theoretical studies and complementary computer simulations have been pursued to elucidate the impact of fluctuations on RF waves. From the full complement of Maxwell's equations for cold, magnetized plasmas, it is shown that the Poynting flux in the wake of filaments develops spatial structure due to diffraction and shadowing. The uniformity of power flow into the plasma is affected by side-scattering, modifications to the wave spectrum, and coupling to plasma waves other than the incident RF wave. The Snell's law and the Fresnel equations have been reformulated within the context of magnetized plasmas. They are distinctly different from their counterparts in scalar dielectric media, and reveal new and important physical insight into the scattering of RF waves. The Snell's law and Fresnel equations are the basis for the Kirchhoff approximation necessary to determine properties of the scattered waves. Furthermore, this theory is also relevant for studying back

  7. 76 FR 56984 - Revision to the Manual of Regulations and Procedures for Federal Radio Frequency Management

    Science.gov (United States)

    2011-09-15

    ... Manual of Regulations and Procedures for Federal Radio Frequency Management AGENCY: National... Radio Frequency Management (NTIA Manual). Specifically, NTIA updates the version of the Manual of Regulations and Procedures for Federal Radio Frequency Management with which federal agencies must comply when...

  8. 75 FR 54790 - Revision to the Manual of Regulations and Procedures for Federal Radio Frequency Management

    Science.gov (United States)

    2010-09-09

    ... Manual of Regulations and Procedures for Federal Radio Frequency Management AGENCY: National... Radio Frequency Management (NTIA Manual). Specifically, NTIA updates the version of the Manual of Regulations and Procedures for Federal Radio Frequency Management with which federal agencies must comply when...

  9. 77 FR 75567 - Revision to the Manual of Regulations and Procedures for Federal Radio Frequency Management

    Science.gov (United States)

    2012-12-21

    ... Manual of Regulations and Procedures for Federal Radio Frequency Management AGENCY: National... Radio Frequency Management (NTIA Manual). Specifically, NTIA updates the version of the Manual of Regulations and Procedures for Federal Radio Frequency Management with which federal agencies must comply when...

  10. 76 FR 18652 - Revision to the Manual of Regulations and Procedures for Federal Radio Frequency Management

    Science.gov (United States)

    2011-04-05

    ... Manual of Regulations and Procedures for Federal Radio Frequency Management AGENCY: National... Radio Frequency Management (NTIA Manual). Specifically, NTIA updates the version of the Manual of Regulations and Procedures for Federal Radio Frequency Management with which federal agencies must comply when...

  11. 78 FR 52097 - Revision to the Manual of Regulations and Procedures for Federal Radio Frequency Management

    Science.gov (United States)

    2013-08-22

    ... Manual of Regulations and Procedures for Federal Radio Frequency Management AGENCY: National... Radio Frequency Management (NTIA Manual). Specifically, NTIA is releasing a new edition of the NTIA Manual, which Federal agencies must comply with when requesting use of radio frequency spectrum. DATES...

  12. 75 FR 6818 - Revision to the Manual of Regulations and Procedures for Federal Radio Frequency Management

    Science.gov (United States)

    2010-02-11

    ... Manual of Regulations and Procedures for Federal Radio Frequency Management AGENCY: National... Radio Frequency Management (NTIA Manual). Specifically, the NTIA updates the version of the Manual of Regulations and Procedures for Federal Radio Frequency Management with which Federal agencies must comply when...

  13. Moessbauer absorption by thick ferromagnets in radio-frequency magnetic field

    CERN Document Server

    Dzyublik, A Y

    2002-01-01

    The dynamical scattering theory is developed for transmission of the Moessbauer radiation through a ferromagnetic absorber of arbitrary thickness whose magnetization periodically reverses under the influence of an external radio-frequency (RF) magnetic field. The thickness dependence of the Moessbauer absorption spectrum as well as the time dependence and energy distribution of the transmitted beam are analyzed. The transmitted spectrum as a function of the frequency of transmitted gamma-quanta, reveals a sideband structure separated by twice the frequency of the RF field, which collapses to a single line at high frequencies.

  14. Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

    Energy Technology Data Exchange (ETDEWEB)

    Manaa, C., E-mail: chadlia.el.manaa@gmail.com [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Lejeune, M. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Kouki, F. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Durand-Drouhin, O. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Bouchriha, H. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); and others

    2014-06-02

    We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method.

  15. Innovative technology evaluation report, radio frequency heating, KAI Technologies, Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Groeber, M.; Krietemeyer, S.; Saylor, E.

    1995-04-01

    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 USEAP and the USAF. The technology was used to remove hydrocarbon contamination from a contaminated site that had been used during waste treatment and storage operations in the past. This report discusses the results of this demonstration and presents an economic analysis of the process.

  16. 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.

  17. 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

  18. 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.

  19. Towards the Realization of Graphene Based Flexible Radio Frequency Receiver

    Directory of Open Access Journals (Sweden)

    Maruthi N. Yogeesh

    2015-11-01

    Full Text Available We report on our progress and development of high speed flexible graphene field effect transistors (GFETs with high electron and hole mobilities (~3000 cm2/V·s, and intrinsic transit frequency in the microwave GHz regime. We also describe the design and fabrication of flexible graphene based radio frequency system. This RF communication system consists of graphite patch antenna at 2.4 GHz, graphene based frequency translation block (frequency doubler and AM demodulator and graphene speaker. The communication blocks are utilized to demonstrate graphene based amplitude modulated (AM radio receiver operating at 2.4 GHz.

  20. Multifrequency radio frequency sensing with photonics-assisted spectrum compression.

    Science.gov (United States)

    Yin, Feifei; Gao, Yuyang; Dai, Yitang; Zhang, Junyi; Xu, Kun; Zhang, Ziping; Li, Jianqiang; Lin, Jintong

    2013-11-01

    We propose and demonstrate a multifrequency radio frequency (RF) spectrum estimation technology. With photonic assistance, a multifrequency RF signal ranging from 0 to 1 GHz is highly spectrally compressed and sensed using a single analog-to-digital converter with analog bandwidth of 42.6 MHz. By calculating the cross correlation of pseudo random binary sequence and the encoded signal, up to 40 RF tones are precisely recognized without large computational load. The employment of optical mixing decreased the cost and increased the performance compared to its electrical counterpart. The theory and performance are also discussed.

  1. Implantable radio frequency identification sensors: wireless power and communication.

    Science.gov (United States)

    Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2011-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm.

  2. Radio-frequency identification: its potential in healthcare.

    Science.gov (United States)

    2005-05-01

    Radio-frequency identification (RFID) technology is just starting to make inroads into healthcare. RFID uses radio-frequency tags attached to people or objects to provide identification, tracking, security, and other functions that fall under the general heading of automatic identification and data capture (AIDC). In the retail supply chain, RFID is already well established as a way to reduce theft and track objects from manufacture through shipment to delivery. In healthcare, basic RFID is already being used to track patients for anti-elopement and anti-abduction programs. As more sophisticated systems move into hospitals, RFID is also beginning to see use to provide more extensive patient identification than traditional bar coding can, and to track and locate capital equipment within the hospital. In years to come, RFID could be used for a variety of applications, including tracking and matching blood for transfusions, tracking pharmaceuticals, and combating the counterfeiting of medical products. RFID may ultimately be used for many of the functions currently carried out using bar coding--but not until the cost of RFID comes down. For the foreseeable future, the two technologies are likely to be used in tandem in many hospitals. In this article, we describe the components and operation of RFID systems and detail the different ways in which these systems are being used, and could be used, in hospitals.

  3. Ge Nanoislands Grown by Radio Frequency Magnetron Sputtering: Comprehensive Investigation of Surface Morphology and Optical Properties

    Directory of Open Access Journals (Sweden)

    Alireza Samavati

    2015-01-01

    Full Text Available The comprehensive investigation of the effect of growth parameters on structural and optical properties of Si-based single layer Ge nanoislands grown via Stranski-Krastanov mechanism employing radio frequency magnetron sputtering due to its high deposition rate, easy procedure, economical cost, and safety is carried out. The estimated width and height of Ge nanoislands produced by this technique are in the range of ∼8 to ∼30 and ∼2 to 8 nm, respectively. Varieties parameters are manipulated to optimize the surface morphology and structural and optical behavior of Ge nanoislands. The resulted nanoislands are analyzed using various analytical techniques including atomic force microscope, X-ray diffraction, energy dispersive X-ray spectroscopy, room temperature photoluminescence, and Raman spectroscopy. The optimum parameters for growing high quality samples having high number density and homogenous and small size distribution are found to be 400°C for substrate temperature, 300 sec for deposition time, 10 sccm for Ar flow, and 100 W for radio frequency power. The excellent features of the results suggest that our systematic investigation on the organized growth factors and their effects on surface parameters and photoluminescence emission energy may constitute a basis for the tunable growth of Ge nanoislands (100 nanoislands suitable in nanophotonics.

  4. Radio-frequency energy harvesting for wearable sensors

    OpenAIRE

    Borges, Luís M.; Chávez-Santiago, Raul; Barroca, Norberto; Velez, Fernando José; Balasingham, Ilangko

    2015-01-01

    The use of wearable biomedical sensors for the continuous monitoring of physiological signals will facilitate the involvement of the patients in the prevention and management of chronic diseases. The fabrication of small biomedical sensors transmitting physiological data wirelessly is possible as a result of the tremendous advances in ultra-low power electronics and radio communications. However, the widespread adoption of these devices depends very much on their ability to operate for long p...

  5. Developing Postharvest Disinfestation Treatments of Legumes Using Radio Frequency Energy.

    Science.gov (United States)

    There is an urgent need to develop technically effective and environmentally sound phytosanitary and quarantine treatments for the legume industry to replace chemical fumigation. The goal of this study was to develop practical non-chemical treatments for postharvest disinfestation of legumes using r...

  6. Developing Postharvest Disinfestation Treatments for Legumes Using Radio Frequency Energy

    Science.gov (United States)

    There is an urgent need to develop technically effective and environmentally sound phytosanitary and quarantine treatments for the legume industry to replace chemical fumigation. The goal of this study was to develop practical non-chemical treatments for postharvest disinfestations of legumes using ...

  7. Efficacy of monopolar dielectric transmission radio frequency in panniculus adiposus and cellulite reduction.

    Science.gov (United States)

    Albornoz-Cabello, Manuel; Ibáñez-Vera, Alfonso Javier; De la Cruz-Torres, Blanca

    2017-11-01

    Despite high incidence rate of cellulite, there are few studies regarding its treatment. Most of them present non-validated evaluation tools. Radio frequency is a focused treatment very used in aesthetics to reduce it. To know the efficacy of Monopolar Dielectric Radio frequency (MDR) treatment in dynamic applications to reduce cellulite, panniculus adiposus and gluteal and posterior thigh regions. Experimental study consisting of inferior members of nine women. They received 10 sessions based on dynamic applications of MDR. Variables included the following: Cellulite Severity Scale (CSS), appearance of the cutaneous area, flaccidity and ultrasound measurement of the panniculus adiposus. The final CSS score of the leg treated reflects statistically significative differences (p = 0.023) when compared with control leg (p = 0.622). Significant reductions of body perimeters at the level of the great trochanter (p = 0.02), the gluteal region (p = 0.03) and the midpoint of the posterior thigh (p = 0.01) are found. The reduction of the panniculus adiposus measured using ultrasound techniques shows significant changes in the midpoint of the posterior thigh (p = 0.028) as well as in the gluteal region (p = 0.03). The dynamic application of MDR seems to be effective in order to reduce not only the thickness of panniculus adiposus but also gluteal and posterior thigh perimeters.

  8. Radio-frequency identification of surgical sponges in the abdominal cavity of pigs.

    Science.gov (United States)

    Wiederkehr, Julio Cesar; Gama, Ricardo R; Wiederkehr, Henrique A; Stelmasuk, Kleber; Carvalho, Caroline A; Wiederkehr, Barbara A

    2014-06-01

    Counting the sponges is an important step in surgical procedures. A miscount may impact the patient's health, and it also has legal implications for the surgeon. This is an experimental study evaluating radio-frequency technology used in the perioperative period to identify surgical sponges left in the peritoneal cavity of swine. Radio-frequency labeled-disc identification tags were sewn into 40 surgical towels. Twenty labels had the ability to emit radio-frequency waves, and 20 labels were inert to radio-frequency identification. Twenty adult pigs that underwent laparotomy and randomly received two surgical sponges were scanned by a radio-frequency identification antenna. This method presented a positive predictive value of 100% and 100% specificity and sensitivity, as all of the tagged surgical sponges were detected. Radio-frequency identification has been proved to be a useful method for the identification of surgical sponges within the abdominal cavities of swine.

  9. Protein adsorption enhanced radio-frequency heating of silica nanoparticles.

    Science.gov (United States)

    Wosik, Jarek; Pande, Rohit; Xie, Leiming; Ketharnath, Dhivya; Srinivasan, Srimeenakshi; Godin, Biana

    2013-07-22

    Measurements of specific-absorption-rate (SAR) of silica 30, 50, and 100 nm nanoparticles (NP) suspended in water were carried out at 30 MHz in 7 kV/m radio-frequency (rf) electric field. Size dependent, NP-suspension interface related heating of silica NP was observed. To investigate a possible mechanism of heating, bovine serum albumin was adsorbed on the surface of silica NPs in suspension. It resulted in significant enhancement of SAR when compared to bare silica NPs. A calorimetric and rf loss model was used to calculate effective conductivity of silica NP with/without adsorbed albumin as a function of silica size and albumin concentration.

  10. A simple, tunable, and highly sensitive radio-frequency sensor.

    Science.gov (United States)

    Cui, Yan; Sun, Jiwei; He, Yuxi; Wang, Zheng; Wang, Pingshan

    2013-08-05

    We report a radio frequency (RF) sensor that exploits tunable attenuators and phase shifters to achieve high-sensitivity and broad band frequency tunability. Three frequency bands are combined to enable sensor operations from ∼20 MHz to ∼38 GHz. The effective quality factor (Qeff ) of the sensor is as high as ∼3.8 × 10(6) with 200 μl of water samples. We also demonstrate the measurement of 2-proponal-water-solution permittivity at 0.01 mole concentration level from ∼1 GHz to ∼10 GHz. Methanol-water solution and de-ionized water are used to calibrate the RF sensor for the quantitative measurements.

  11. 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.

  12. Numerical model study of radio frequency vessel sealing thermodynamics

    Science.gov (United States)

    Pearce, John

    2015-03-01

    Several clinically successful clinical radio frequency vessel-sealing devices are currently available. The dominant thermodynamic principles at work involve tissue water vaporization processes. It is necessary to thermally denature vessel collagen, elastin and their adherent proteins to achieve a successful fusion. Collagens denature at middle temperatures, between about 60 and 90 C depending on heating time and rate. Elastin, and its adherent proteins, are more thermally robust, and require temperatures in excess of the boiling point of water at atmospheric pressure to thermally fuse. Rapid boiling at low apposition pressures leads to steam vacuole formation, brittle tissue remnants and frequently to substantial disruption in the vessel wall, particularly in high elastin-content arteries. High apposition pressures substantially increase the equilibrium boiling point of tissue water and are necessary to ensure a high probability of a successful seal. The FDM numerical models illustrate the beneficial effects of high apposition pressures.

  13. Radio frequency communication system utilizing radiating transmission lines

    Science.gov (United States)

    Struven, Warren C.

    1984-01-01

    A radio communication system for use in tunnels, mines, buildings or other shielded locations in which a pair of radiating transmission lines (30), (31) extend through such location in spaced coextensive relation to each other. Each transmission line (30), (31) has at least one unidirectional amplifier (32), (33) interposed therein with the sense of the unidirectional amplifier (32) of one transmission line (30) being opposite to the sense of the unidirectional amplifier (33) of the other transmission line (31). Each of the amplifiers (32), (33) has a gain which is less than the coupling loss between the transmission lines (30), (31). Two or more mobile transceivers (35) in the location served by the system are coupled to the transmission lines (30), (31) by electromagnetic wave propagation in space in order to communicate directly with each other at a given radio frequency within the frequency range of the system.

  14. Electrochemical system and method for electropolishing superconductive radio frequency cavities

    Science.gov (United States)

    Taylor, E. Jennings; Inman, Maria E.; Hall, Timothy

    2015-04-14

    An electrochemical finishing system for super conducting radio frequency (SCRF) cavities including a low viscosity electrolyte solution that is free of hydrofluoric acid, an electrode in contact with the electrolyte solution, the SCRF cavity being spaced apart from the electrode and in contact with the electrolyte solution and a power source including a first electrical lead electrically coupled to the electrode and a second electrical lead electrically coupled to the cavity, the power source being configured to pass an electric current between the electrode and the workpiece, wherein the electric current includes anodic pulses and cathodic pulses, and wherein the cathodic pulses are interposed between at least some of the anodic pulses. The SCRF cavity may be vertically oriented during the finishing process.

  15. Multiplexed infrared photodetection using resonant radio-frequency circuits

    Energy Technology Data Exchange (ETDEWEB)

    Liu, R.; Lu, R.; Gong, S.; Wasserman, D. [Department of Electrical and Computer Engineering, University of Illinois Urbana Champaign, Urbana, Illinois 61801 (United States); Roberts, C. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Allen, J. W.; Allen, M. S. [Air Force Research Laboratory, Munitions Directorate, Eglin Air Force Base, Florida 32542 (United States); Wenner, B. R. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States)

    2016-02-08

    We demonstrate a room-temperature semiconductor-based photodetector where readout is achieved using a resonant radio-frequency (RF) circuit consisting of a microstrip split-ring resonator coupled to a microstrip busline, fabricated on a semiconductor substrate. The RF resonant circuits are characterized at RF frequencies as function of resonator geometry, as well as for their response to incident IR radiation. The detectors are modeled analytically and using commercial simulation software, with good agreement to our experimental results. Though the detector sensitivity is weak, the detector architecture offers the potential for multiplexing arrays of detectors on a single read-out line, in addition to high speed response for either direct coupling of optical signals to RF circuitry, or alternatively, carrier dynamics characterization of semiconductor, or other, material systems.

  16. High-Performance Control in Radio Frequency Power Amplification Systems

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod

    This thesis presents a broad study of methods for increasing the efficiency of narrow-band radio transmitters. The study is centered around the base station application and TETRA/TEDS networks. The general solution space studied is that of envelope tracking applied to linear class-A/B radio...... frequency power amplifiers (RFPAs) in conjunction with cartesian feedback (CFB) used to linearize the overall transmitter system. On a system level, it is demonstrated how envelope tracking is particularly useful for RF carriers with high peak-to-average power ratios, such as TEDS with 10dB. It is also...... and ripple voltage. It is found that the simple fourth-order filter buck converter is ideal for TETRA and TEDS envelope tracking power supplies. The problem of extracting maximum control bandwidth from a given power topology is given particular attention, with a range of, arguably new, insights resulting...

  17. Security risks associated with radio frequency identification in medical environments.

    Science.gov (United States)

    Hawrylak, Peter J; Schimke, Nakeisha; Hale, John; Papa, Mauricio

    2012-12-01

    Radio frequency identification (RFID) is a form of wireless communication that is used to identify assets and people. RFID has significant benefits to the medical environment. However, serious security threats are present in RFID systems that must be addressed in a medical environment. Of particular interest are threats to patient privacy and safety based on interception of messages, interruption of communication, modification of data, and fabrication of messages and devices. This paper presents an overview of these security threats present in RFID systems in a medical environment and provides guidance on potential solutions to these threats. This paper provides a roadmap for researchers and implementers to address the security issues facing RFID in the medical space.

  18. Spurs in digital radio frequency memory and applications of DRFM

    Science.gov (United States)

    Nityananda, B. V.

    1993-09-01

    A method to calculate the power level of harmonics generated in digital radio frequency memory (DRFM) due to sampling and quantization process is presented. The Fourier series analysis is used for the calculation of the harmonic levels. The quantization process generates the harmonics of the fundamental signal which is folded into the DRFM instantaneous bandwidth by the sampling process. Power level of the harmonics is dependent on the number of quantization bits of the analog to digital converter. It is also dependent on the ratio of signal frequency to sampling frequency. MATLAB programs for computation of harmonic power levels and plots of harmonic power levels of multibit DRFM are included in the thesis. Some applications of the DRFM, such as deception jammer, broadband frequency source, and radar simulator, are also discussed.

  19. Radio frequency feedback method for parallelized droplet microfluidics

    KAUST Repository

    Conchouso Gonzalez, David

    2016-12-19

    This paper reports on a radio frequency micro-strip T-resonator that is integrated to a parallel droplet microfluidic system. The T-resonator works as a feedback system to monitor uniform droplet production and to detect, in real-time, any malfunctions due to channel fouling or clogging. Emulsions at different W/O flow-rate ratios are generated in a microfluidic device containing 8 parallelized generators. These emulsions are then guided towards the RF sensor, which is then read using a Network Analyzer to obtain the frequency response of the system. The proposed T-resonator shows frequency shifts of 45MHz for only 5% change in the emulsion\\'s water in oil content. These shifts can then be used as a feedback system to trigger alarms and notify production and quality control engineers about problems in the droplet generation process.

  20. Analysis of transverse beam stabilization with radio frequency quadrupoles

    Science.gov (United States)

    Schenk, M.; Grudiev, A.; Li, K.; Papke, K.

    2017-10-01

    A radio frequency (rf) quadrupole has been considered as a potential alternative device for Landau damping in circular hadron colliders. The objective of this study is to benchmark and confirm its stabilizing effect predicted by stability diagram theory by means of numerical tracking simulations. To that end, two complementary models of the device are implemented in pyheadtail, a 6D macroparticle tracking code designed to study the formation and mitigation of collective instabilities. The rf quadrupole model is applied to a slow head-tail instability observed experimentally in the Large Hadron Collider to show that such a device can in principle provide beam stability similarly to magnetic octupoles. Thereafter, alternative usage schemes of rf quadrupoles also in combination with magnetic octupoles are proposed, discussed, and benchmarked with simulations.

  1. Peak radiated power measurement of the DOE Mark II container tag with integrated ST-676 sensor radio frequency identification device.

    Energy Technology Data Exchange (ETDEWEB)

    Jursich, Mark

    2010-04-01

    The total peak radiated power of the Department of Energy Mark II container tag was measured in the electromagnetic reverberation chamber facility at Sandia National Laboratories. The tag's radio frequency content was also evaluated for possible emissions outside the intentional transmit frequency band. No spurious emissions of any significance were found, and the radiated power conformed to the manufacturer's specifications.

  2. Feasibility study of a decelerating radio frequency quadrupole system for the antiproton decelerator AD

    CERN Document Server

    Bosser, Jacques; Brouet, M; Couturier, B; Gelato, G; Giovannozzi, Massimo; Grandclaude, F; Hémery, J Y; Lombardi, A M; Mikkelsen, U; Maury, S; Möhl, D; Pedersen, F; Pirkl, Werner; Raich, U; Umstätter, H H; Vretenar, Maurizio

    1998-01-01

    This feasibility study reports on a decelerating Radio-Frequency Quadrupole (RFQ) system for post-deceleration of the 100 MeV/c antiproton beam of the AD machine. The corresponding kinetic energy of 5.314 MeV is reduced to values which can be chosen between 10 to 100 keV with minimal blow-up of the normalised beam emittances. This wide range of output energy is required for the second phase of the ASACUSA experiment; it is achieved by electrostatic means. The study gives details of the overall performance of the system, the proposed implementation of the RFQ, the associated rf equipment, the beam lines, the diagnostics as well as estimations for the cost and the manpower requirements of the project.

  3. An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source

    Energy Technology Data Exchange (ETDEWEB)

    C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg

    2011-09-01

    We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ('afterburner'). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

  4. Upgrading producer gas quality from rubber wood gasification in a radio frequency tar thermocatalytic treatment reactor.

    Science.gov (United States)

    Anis, Samsudin; Zainal, Z A

    2013-12-01

    This study focused on improving the producer gas quality using radio frequency (RF) tar thermocatalytic treatment reactor. The producer gas containing tar, particles and water was directly passed at a particular flow rate into the RF reactor at various temperatures for catalytic and thermal treatments. Thermal treatment generates higher heating value of 5.76 MJ Nm(-3) at 1200°C. Catalytic treatments using both dolomite and Y-zeolite provide high tar and particles conversion efficiencies of about 97% on average. The result also showed that light poly-aromatic hydrocarbons especially naphthalene and aromatic compounds particularly benzene and toluene were still found even at higher reaction temperatures. Low energy intensive RF tar thermocatalytic treatment was found to be effective for upgrading the producer gas quality to meet the end user requirements and increasing its energy content. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Studies on the radio frequency power supply system for the ITER NB injector ion source

    Energy Technology Data Exchange (ETDEWEB)

    Gaio, E. [Consorzio RFX-Associazione EURATOM-ENEA sulla Fusione, C.so Stati Uniti 4, 35127 Padova (Italy)], E-mail: elena.gaio@igi.cnr.it; Kraus, W.; Martens, C. [Max-Planck-Institut fuer Plasmaphysik, Postfach 1533, D-85740 Garching (Germany); Piovan, R. [Consorzio RFX-Associazione EURATOM-ENEA sulla Fusione, C.so Stati Uniti 4, 35127 Padova (Italy); Speth, E. [Max-Planck-Institut fuer Plasmaphysik, Postfach 1533, D-85740 Garching (Germany); Toigo, V. [Consorzio RFX-Associazione EURATOM-ENEA sulla Fusione, C.so Stati Uniti 4, 35127 Padova (Italy)

    2007-10-15

    In the framework of the European activities on the ITER neutral beam (NB) injector, the design of a 1 MHz, 1 MW power supply (PS) system for the radio frequency (RF) driven ion source, has been developed in cooperation between IPP and RFX laboratories. This paper describes the studies performed with particular emphasis on the system design, the definition of the best modularity level to be adopted and the integration of the RF PS in the overall power supply system of the NB injector. Dedicated analyses were addressed to the RF matching network optimization which led to an improved and simplified solution without both matching transformers and remotely controlled variable capacitors in the source.

  6. Wireless Chalcogenide Nanoionic-Based Radio-Frequency Switch

    Science.gov (United States)

    Nessel, James; Miranda, Felix

    2013-01-01

    A new nonvolatile nanoionic switch is powered and controlled through wireless radio-frequency (RF) transmission. A thin layer of chalcogenide glass doped with a metal ion, such as silver, comprises the operational portion of the switch. For the switch to function, an oxidizable electrode is made positive (anode) with respect to an opposing electrode (cathode) when sufficient bias, typically on the order of a few tenths of a volt or more, is applied. This action causes the metal ions to flow toward the cathode through a coordinated hopping mechanism. At the cathode, a reduction reaction occurs to form a metal deposit. This metal deposit creates a conductive path that bridges the gap between electrodes to turn the switch on. Once this conductive path is formed, no further power is required to maintain it. To reverse this process, the metal deposit is made positive with respect to the original oxidizable electrode, causing the dissolution of the metal bridge thereby turning the switch off. Once the metal deposit has been completely dissolved, the process self-terminates. This switching process features the following attributes. It requires very little to change states (i.e., on and off). Furthermore, no power is required to maintain the states; hence, the state of the switch is nonvolatile. Because of these attributes the integration of a rectenna to provide the necessary power and control is unique to this embodiment. A rectenna, or rectifying antenna, generates DC power from an incident RF signal. The low voltages and power required for the nanoionic switch control are easily generated from this system and provide the switch with a novel capability to be operated and powered from an external wireless device. In one realization, an RF signal of a specific frequency can be used to set the switch into an off state, while another frequency can be used to set the switch to an on state. The wireless, miniaturized, and nomoving- part features of this switch make it

  7. Optimizing radio frequency identification network planning through ring probabilistic logic neurons

    Directory of Open Access Journals (Sweden)

    Aydin Azizi

    2016-08-01

    Full Text Available Radio frequency identification is a developing technology that has recently been adopted in industrial applications for identification and tracking operations. The radio frequency identification network planning problem deals with many criteria like number and positions of the deployed antennas in the networks, transmitted power of antennas, and coverage of network. All these criteria must satisfy a set of objectives, such as load balance, economic efficiency, and interference, in order to obtain accurate and reliable network planning. Achieving the best solution for radio frequency identification network planning has been an area of great interest for many scientists. This article introduces the Ring Probabilistic Logic Neuron as a time-efficient and accurate algorithm to deal with the radio frequency identification network planning problem. To achieve the best results, redundant antenna elimination algorithm is used in addition to the proposed optimization techniques. The aim of proposed algorithm is to solve the radio frequency identification network planning problem and to design a cost-effective radio frequency identification network by minimizing the number of embedded radio frequency identification antennas in the network, minimizing collision of antennas, and maximizing coverage area of the objects. The proposed solution is compared with the evolutionary algorithms, namely genetic algorithm and particle swarm optimization. The simulation results show that the Ring Probabilistic Logic Neuron algorithm obtains a far more superior solution for radio frequency identification network planning problem when compared to genetic algorithm and particle swarm optimization.

  8. 47 CFR 2.803 - Marketing of radio frequency devices prior to equipment authorization.

    Science.gov (United States)

    2010-10-01

    ..., commercial, industrial, scientific, and medical users (excluding products sold to other parties or for... 47 Telecommunication 1 2010-10-01 2010-10-01 false Marketing of radio frequency devices prior to... FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency...

  9. 78 FR 13893 - Certain Radio Frequency Identification (“RFID”) Products and Components Thereof; Notice of...

    Science.gov (United States)

    2013-03-01

    ... COMMISSION Certain Radio Frequency Identification (``RFID'') Products and Components Thereof; Notice of... Commission has received a complaint entitled Certain Radio Frequency Identification (``RFID'') Products and..., the sale for importation, and the sale within the United States after importation of certain radio...

  10. 48 CFR 552.211-92 - Radio Frequency Identification (RFID) using passive tags.

    Science.gov (United States)

    2010-10-01

    ... Identification (RFID) using passive tags. 552.211-92 Section 552.211-92 Federal Acquisition Regulations System... Provisions and Clauses 552.211-92 Radio Frequency Identification (RFID) using passive tags. As prescribed in 511.204(b)(11), insert the following clause: Radio Frequency Identification (RFID) Using Passive Tags...

  11. Investigations and Applications of Field- and Photo-emitted Electron Beams from a Radio Frequency Gun

    Energy Technology Data Exchange (ETDEWEB)

    Panuganti, SriHarsha [Northern Illinois Univ., DeKalb, IL (United States)

    2015-08-01

    Production of quality electron bunches using e cient ways of generation is a crucial aspect of accelerator technology. Radio frequency electron guns are widely used to generate and rapidly accelerate electron beams to relativistic energies. In the current work, we primarily study the charge generation processes of photoemission and eld emission inside an RF gun installed at Fermilab's High Brightness Electron Source Laboratory (HBESL). Speci cally, we study and characterize second-order nonlinear photoemission from a Cesium Telluride (Cs2Te) semiconductor photocathode, and eld emission from carbon based cathodes including diamond eld emission array (DFEA) and carbon nanotube (CNT) cathodes located in the RF gun's cavity. Finally, we discuss the application experiments conducted at the facility to produce soft x-rays via inverse Compton scattering (ICS), and to generate uniformly lled ellipsoidal bunches and temporally shaped electron beams from the Cs2Te photocathode.

  12. Evolutionary Beamforming Optimization for Radio Frequency Charging in Wireless Rechargeable Sensor Networks.

    Science.gov (United States)

    Yao, Ke-Han; Jiang, Jehn-Ruey; Tsai, Chung-Hsien; Wu, Zong-Syun

    2017-08-20

    This paper investigates how to efficiently charge sensor nodes in a wireless rechargeable sensor network (WRSN) with radio frequency (RF) chargers to make the network sustainable. An RF charger is assumed to be equipped with a uniform circular array (UCA) of 12 antennas with the radius λ, where λ is the RF wavelength. The UCA can steer most RF energy in a target direction to charge a specific WRSN node by the beamforming technology. Two evolutionary algorithms (EAs) using the evolution strategy (ES), namely the Evolutionary Beamforming Optimization (EBO) algorithm and the Evolutionary Beamforming Optimization Reseeding (EBO-R) algorithm, are proposed to nearly optimize the power ratio of the UCA beamforming peak side lobe (PSL) and the main lobe (ML) aimed at the given target direction. The proposed algorithms are simulated for performance evaluation and are compared with a related algorithm, called Particle Swarm Optimization Gravitational Search Algorithm-Explore (PSOGSA-Explore), to show their superiority.

  13. Evolutionary Beamforming Optimization for Radio Frequency Charging in Wireless Rechargeable Sensor Networks

    Science.gov (United States)

    Yao, Ke-Han; Jiang, Jehn-Ruey; Tsai, Chung-Hsien; Wu, Zong-Syun

    2017-01-01

    This paper investigates how to efficiently charge sensor nodes in a wireless rechargeable sensor network (WRSN) with radio frequency (RF) chargers to make the network sustainable. An RF charger is assumed to be equipped with a uniform circular array (UCA) of 12 antennas with the radius λ, where λ is the RF wavelength. The UCA can steer most RF energy in a target direction to charge a specific WRSN node by the beamforming technology. Two evolutionary algorithms (EAs) using the evolution strategy (ES), namely the Evolutionary Beamforming Optimization (EBO) algorithm and the Evolutionary Beamforming Optimization Reseeding (EBO-R) algorithm, are proposed to nearly optimize the power ratio of the UCA beamforming peak side lobe (PSL) and the main lobe (ML) aimed at the given target direction. The proposed algorithms are simulated for performance evaluation and are compared with a related algorithm, called Particle Swarm Optimization Gravitational Search Algorithm-Explore (PSOGSA-Explore), to show their superiority. PMID:28825648

  14. Detection of pulsars PSR 1133 + 16 and PSR 2045-16 at low radio frequencies

    Science.gov (United States)

    Reyes, F.; Carr, T. D.; Oliver, J. P.; May, J.; Bitran, M.; Aparici, J.

    1981-12-01

    Two pulsars have been observed at low radio frequencies using a narrow bandwidth to avoid pulse dispersion problems, PSR 1133 + 16 was observed at 26.3 MHz using the University of Florida 640-dipole radiotelescope. PSR 2045-16 was observed at 45 MHz using the MaipuRadio Astronomy Observatory 528-dipole radiotelescope. Digital averaging and period-stacking techniques were used in order to increase the signal-to-noise ratio. Both pulsars were successfully detected by averaging typically 400 to 600 periods. The integrated pulse profile, pulse width and an estimate of the pulse flux density and energy were obtained. The systematic observation of pulsars using both radiotelescopes will be soon started.

  15. A computationally assisted spectroscopic technique to measure secondary electron emission coefficients in radio frequency plasmas

    CERN Document Server

    Daksha, M; Schuengel, E; Korolov, I; Derzsi, A; Koepke, M; Donko, Z; Schulze, J

    2016-01-01

    A Computationally Assisted Spectroscopic Technique to measure secondary electron emission coefficients ($\\gamma$-CAST) in capacitively-coupled radio-frequency plasmas is proposed. This non-intrusive, sensitive diagnostic is based on a combination of Phase Resolved Optical Emission Spectroscopy and particle-based kinetic simulations. In such plasmas (under most conditions in electropositive gases) the spatio-temporally resolved electron-impact excitation/ionization rate features two distinct maxima adjacent to each electrode at different times within each RF period. While one maximum is the consequence of the energy gain of electrons due to sheath expansion, the second maximum is produced by secondary electrons accelerated towards the plasma bulk by the sheath electric field at the time of maximum voltage drop across the adjacent sheath. Due to these different excitation/ionization mechanisms, the ratio of the intensities of these maxima is very sensitive to the secondary electron emission coefficient $\\gamma$...

  16. Microminiature radio frequency transmitter for communication and tracking applications

    Science.gov (United States)

    Crutcher, Richard I.; Emery, Mike S.; Falter, Kelly G.; Nowlin, C. H.; Rochelle, Jim M.; Clonts, Lloyd G.

    1997-02-01

    A micro-miniature radio frequency (rf) transmitter has been developed and demonstrated by the Oak Ridge National Laboratory. The objective of the rf transmitter development was to maximize the transmission distance while drastically shrinking the overall transmitter size, including antenna. Based on analysis and testing, an application-specific integrated circuit (ASIC) with a 16-GHz gallium arsenide (GaAs) oscillator and integrated on-chip antenna was designed and fabricated using microwave monolithic integrated circuit (MMIC) technology. Details of the development and the results of various field tests are discussed. The rf transmitter is applicable to covert surveillance and tracking scenarios due to its small size of 2.2 multiplied by 2.2 mm, including the antenna. Additionally, the 16-GHz frequency is well above the operational range of consumer-grade radio scanners, providing a degree of protection from unauthorized interception. Variations of the transmitter design have been demonstrated for tracking and tagging beacons, transmission of digital data, and transmission of real-time analog video from a surveillance camera. Preliminary laboratory measurements indicate adaptability to direct-sequence spread-spectrum transmission, providing a low probability of intercept and/or detection. Concepts related to law enforcement applications are presented.

  17. Operating a radio-frequency plasma source on water vapor.

    Science.gov (United States)

    Nguyen, Sonca V T; Foster, John E; Gallimore, Alec D

    2009-08-01

    A magnetically enhanced radio-frequency (rf) plasma source operating on water vapor has an extensive list of potential applications. In this work, the use of a rf plasma source to dissociate water vapor for hydrogen production is investigated. This paper describes a rf plasma source operated on water vapor and characterizes its plasma properties using a Langmuir probe, a residual gas analyzer, and a spectrometer. The plasma source operated first on argon and then on water vapor at operating pressures just over 300 mtorr. Argon and water vapor plasma number densities differ significantly. In the electropositive argon plasma, quasineutrality requires n(i) approximately = n(e), where n(i) is the positive ion density. But in the electronegative water plasma, quasineutrality requires n(i+) = n(i-) + n(e). The positive ion density and electron density of the water vapor plasma are approximately one and two orders of magnitude lower, respectively, than those of argon plasma. These results suggest that attachment and dissociative attachment are present in electronegative water vapor plasma. The electron temperature for this water vapor plasma source is between 1.5 and 4 eV. Without an applied axial magnetic field, hydrogen production increases linearly with rf power. With an axial magnetic field, hydrogen production jumps to a maximum value at 500 W and then saturates with rf power. The presence of the applied axial magnetic field is therefore shown to enhance hydrogen production.

  18. Accessibility of Radio Frequency Identification Technology in Facilities Maintenance

    Directory of Open Access Journals (Sweden)

    Chien-Ho Ko

    2017-01-01

    Full Text Available Replacing old buildings with new structures is an expensive proposition, but the service life of existing buildings can be extended by improving facilities maintenance. In particular, effective use of information technology can improve facilities maintenance and reduce maintenance costs. In recent years, some scholars have begun to apply Radio Frequency Identification (RFID technology to facilities maintenance. The present study examines the effective reading range for RFID applications within the context of facilities maintenance, where such applications can provide advantages including automatic reading and encoding of equipment, rapid reading and encoding of tag information, and tag-based data storage. However, the reading range of RFID tags can be limited by the presence of water vapor, electrical appliances, and metal surfaces. Through practical onsite testing, the study examines how effective reading range is impacted by dust, water, metal surfaces and electrical equipment, along with various reading and writing angles. Experimental results show that the presence of dust and water both have insignificant impacts on RFID signal reading. However, metal surfaces were found to have a significant negative effect on signal reading and RFID tags should be kept an appropriate distance from such materials. The results of this study can be taken as reference for the use of RFID in facilities maintenance and management.

  19. An application of uncertain numbers in radio frequency power measurement

    Science.gov (United States)

    Hall, B. D.

    2009-06-01

    The uncertain-numbers method (Hall B D 2006 Metrologia 43 L56-61) is an alternative computational procedure to the Law of Propagation of Uncertainty (LPU) described in the Guide to the Expression of Uncertainty in Measurement. One advantage of the method is that data processing can be carried out in an arbitrary series of steps and much of the mathematical analysis normally associated with the LPU can be automated by software. This has applications for measuring systems, which are modular in design and use internal data processing to apply corrections to raw data. Several scenarios involving radio frequency power measurements are used to illustrate the new method in this context. The scenarios show something of the difficulty inherent in calculating uncertainty for modern measurement systems and in particular highlight the occurrence of systematic errors arising from internal instrument correction factors. Such errors introduce correlation to a series of measurements and must be handled with care when functions of results, such as means, differences and ratios, are required.

  20. Radio Frequency Interference Site Survey for Thai Radio Telescopes

    Science.gov (United States)

    Jaroenjittichai, P.; Punyawarin, S.; Singwong, D.; Somboonpon, P.; Prasert, N.; Bandudej, K.; Kempet, P.; Leckngam, A.; Poshyachinda, S.; Soonthornthum, B.; Kramer, B.

    2017-09-01

    Radio astronomical observations have increasingly been threaten by the march of today telecommunication and wireless technology. Performance of radio telescopes lies within the fact that astronomical sources are extremely weak. National Astronomy Research Institute of Thailand (NARIT) has initiated a 5-year project, known as the Radio Astronomy Network and Geodesy for Development (RANGD), which includes the establishment of 40-meter and 13-meter radio telescopes. Possible locations have been narrowed down to three candidates, situated in the Northern part of Thailand, where the atmosphere is sufficiently dry and suitable for 22 and 43 GHz observations. The Radio Frequency Interference (RFI) measurements were carried out with a DC spectrum analyzer and directional antennas at 1.5 meter above ground, from 20 MHz to 6 GHz with full azimuth coverage. The data from a 3-minute pointing were recorded for both horizontal and vertical polarizations, in maxhold and average modes. The results, for which we used to make preliminary site selection, show signals from typical broadcast and telecommunication services and aeronautics applications. The signal intensity varies accordingly to the presence of nearby population and topography of the region.

  1. Accoustic Localization of Breakdown in Radio Frequency Accelerating Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Peter Gwin [IIT, Chicago

    2016-07-01

    Current designs for muon accelerators require high-gradient radio frequency (RF) cavities to be placed in solenoidal magnetic fields. These fields help contain and efficiently reduce the phase space volume of source muons in order to create a usable muon beam for collider and neutrino experiments. In this context and in general, the use of RF cavities in strong magnetic fields has its challenges. It has been found that placing normal conducting RF cavities in strong magnetic fields reduces the threshold at which RF cavity breakdown occurs. To aid the effort to study RF cavity breakdown in magnetic fields, it would be helpful to have a diagnostic tool which can localize the source of breakdown sparks inside the cavity. These sparks generate thermal shocks to small regions of the inner cavity wall that can be detected and localized using microphones attached to the outer cavity surface. Details on RF cavity sound sources as well as the hardware, software, and algorithms used to localize the source of sound emitted from breakdown thermal shocks are presented. In addition, results from simulations and experiments on three RF cavities, namely the Aluminum Mock Cavity, the High-Pressure Cavity, and the Modular Cavity, are also given. These results demonstrate the validity and effectiveness of the described technique for acoustic localization of breakdown.

  2. Radio frequency integrated circuit design for cognitive radio systems

    CERN Document Server

    Fahim, Amr

    2015-01-01

    This book fills a disconnect in the literature between Cognitive Radio systems and a detailed account of the circuit implementation and architectures required to implement such systems.  Throughout the book, requirements and constraints imposed by cognitive radio systems are emphasized when discussing the circuit implementation details.  In addition, this book details several novel concepts that advance state-of-the-art cognitive radio systems.  This is a valuable reference for anybody with background in analog and radio frequency (RF) integrated circuit design, needing to learn more about integrated circuits requirements and implementation for cognitive radio systems. ·         Describes in detail cognitive radio systems, as well as the circuit implementation and architectures required to implement them; ·         Serves as an excellent reference to state-of-the-art wideband transceiver design; ·         Emphasizes practical requirements and constraints imposed by cognitive radi...

  3. Targeted Treatment With Radio Frequency Ablation for Lingual Tonsil.

    Science.gov (United States)

    Renkonen, Suvi; Mäkitie, Antti A; Bäck, Leif

    2018-01-01

    Benign enlargement of the lingual tonsils due to various causes may cause symptoms that warrant treatment. Conventional lingual tonsillectomy remains a challenging procedure, and there is no established standard procedure. We aimed to review the patients receiving different methods of lingual tonsil surgery for various indications at our institute. Retrospective clinical data on all patients with an ablative operation of the tongue base during the 8-year period between 2007 and 2014 at the Helsinki University Hospital, Helsinki, Finland, were reviewed. The larger cohort comprised 35 patients, of whom 26 were men (74%). Ten patients had undergone solely lingual tonsil radio frequency ablation (LTRFA). The minimum follow-up time for all patients was 2 years. Of the 10 patients, 5 patients with LTRFA had been operated on because of symptomatic lingual tonsil hypertrophy and 5 because of periodic fever associated with possible lingual tonsil involvement. In 2 of the 5 patients with periodic fever, the fever cycles ended after the operation. Of the 5 patients, 3 patients with symptomatic lingual tonsil hypertrophy have been non-symptomatic after 1 to 3 treatment sessions. The last 2 patients continue to have persistent symptoms. There were no major complications. Development of new approaches for the management of various lingual tonsil conditions is warranted. Lingual tonsil volume reduction by LTRFA seems to be a treatment alternative with low morbidity but with limited curative effect only.

  4. Optical Programmable Radio Frequency Matched Filtering Using Photorefractive Effect.

    Science.gov (United States)

    Lee, Byoungho

    In this thesis the feasibility of optical programmable radio frequency (rf) matched filtering using the photorefractive effect is studied. The optical rf matched filter system proposed in this thesis is based on the use of a photorefractive crystal with a unique interface that provides easy input of rf signals for programming and for the correlation operation. The rf signals are given to an acousto-optic modulator. Laser beams deflected from the modulator have wavefronts which contain the information of the rf signals. The beams illuminate a photorefractive crystal to form reference gratings or to be correlated with the holograms. Reference holograms are stored by angular multiplexing one of the pump beams. This is performed by using a mode-locked laser and letting the pulse repetition rate be integrally related to the electrical signal frequencies given to the acousto-optic modulators. This method allows stable grating formation with nondegenerate waves. An orthogonal signal storage and reading method is devised, which enables one to distinguish different beams illuminating the same hologram region. Experiments were performed with a mode-locked argon ion laser and a cerium-doped strontium barium niobate crystal which is used as a photorefractive medium. The results verify the ideas on which the optical programmable rf matched filter is based. This study raises the possibility of forming a large number of parallel matched filters in a single photorefractive crystal which would allow easy signal storage and rapid correlation analyses.

  5. Propagation of radio frequency waves through density fluctuations

    Science.gov (United States)

    Valvis, S. I.; Papagiannis, P.; Papadopoulos, A.; Hizanidis, K.; Glytsis, E.; Bairaktaris, F.; Zisis, A.; Tigelis, I.; Ram, A. K.

    2017-10-01

    On their way to the core of a tokamak plasma, radio frequency (RF) waves, excited in the vacuum region, have to propagate through a variety of density fluctuations in the edge region. These fluctuations include coherent structures, like blobs that can be field aligned or not, as well as turbulent and filamentary structures. We have been studying the effect of fluctuations on RF propagation using both theoretical (analytical) and computational models. The theoretical results are being compared with those obtained by two different numerical codes ``a Finite Difference Frequency Domain code and the commercial COMSOL package. For plasmas with arbitrary distribution of coherent and turbulent fluctuations, we have formulated an effective dielectric permittivity of the edge plasma. This permittivity tensor is then used in numerical simulations to study the effect of multi-scale turbulence on RF waves. We not only consider plane waves but also Gaussian beams in the electron cyclotron and lower hybrid range of frequencies. The analytical theory and results from simulations on the propagation of RF waves will be presented. Supported in part by the Hellenic National Programme on Controlled Thermonuclear Fusion associated with the EUROfusion Consortium and by DoE Grant DE-FG02-91ER-54109.

  6. A whole body statistical shape model for radio frequency simulation.

    Science.gov (United States)

    Lee, Su-Lin; Ali, Khaleda; Brizzi, Alessio; Keegan, Jennifer; Hao, Yang; Yang, Guang-Zhong

    2011-01-01

    The development of ultra low power wireless sensors for customized wearable and implantable medical devices requires patient specific models for radio frequency simulation to understand wave propagation in the body. In practice, the creation of a patient specific whole-body model is difficult and time consuming to create. It is therefore necessary to establish a method for studying a population in a statistical manner. In this paper, we present a statistical shape model for the whole body for RF simulation. It is built from 10 male and 10 female subjects of varying size and height. This model has the ability to instantiate a new surface mesh with the parameters allowed by the training set. This model would provide shapes of varying sizes for studies, without the requirement of obtaining subject specific whole body models. Results from finite-differences time-domain simulation are presented on the extreme shapes from the model and demonstrate the need for a full understanding of the range in body shapes.

  7. 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

  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. Development of A Pulse Radio-Frequency Plasma Jet

    Science.gov (United States)

    Wang, Shou-Guo; Zhao, Ling-Li; Yang, Jing-Hua

    2013-09-01

    A small pulse plasma jet was driven by new developed radio-frequency (RF) power supply of 6.78 MHz. In contrast to the conventional RF 13.56 MHz atmospheric pressure plasma jet (APPJ), the power supply was highly simplified by eliminating the matching unit of the RF power supply and using a new circuit, moreover, a pulse controller was added to the circuit to produce the pulse discharge. The plasma jet was operated in a capacitively coupled manner and exhibited low power requirement of 5 W at atmospheric pressure using argon as a carrier gas. The pulse plasma plume temperature remained at less than 45 °C for an extended period of operation without using water to cool the electrodes. Optical emission spectrum measured at a wide range of 200-1000 nm indicated various excited species which were helpful in applying the plasma jet for surface sterilization to human skin or other sensitive materials. Institude of Plasma Physics, Chinese Academy of Science, Hefei, China.

  10. 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.

  11. Management of surgical instruments with radio frequency identification tags.

    Science.gov (United States)

    Kusuda, Kaori; Yamashita, Kazuhiko; Ohnishi, Akiko; Tanaka, Kiyohito; Komino, Masaru; Honda, Hiroshi; Tanaka, Shinichi; Okubo, Takashi; Tripette, Julien; Ohta, Yuji

    2016-01-01

    To prevent malpractices, medical staff has adopted inventory time-outs and/or checklists. Accurate inventory and maintenance of surgical instruments decreases the risk of operating room miscounting and malfunction. In our previous study, an individual management of surgical instruments was accomplished using Radio Frequency Identification (RFID) tags. The purpose of this paper is to evaluate a new management method of RFID-tagged instruments. The management system of RFID-tagged surgical instruments was used for 27 months in clinical areas. In total, 13 study participants assembled surgical trays in the central sterile supply department. While using the management system, trays were assembled 94 times. During this period, no assembly errors occurred. An instrument malfunction had occurred after the 19th, 56th, and 73 th uses, no malfunction caused by the RFID tags, and usage history had been recorded. Additionally, the time it took to assemble surgical trays was recorded, and the long-term usability of the management system was evaluated. The system could record the number of uses and the defective history of each surgical instrument. In addition, the history of the frequency of instruments being transferred from one tray to another was recorded. The results suggest that our system can be used to manage instruments safely. Additionally, the management system was acquired of the learning effect and the usability on daily maintenance. This finding suggests that the management system examined here ensures surgical instrument and tray assembly quality.

  12. High-performance radio frequency transistors based on diameter-separated semiconducting carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yu; Che, Yuchi; Zhou, Chongwu, E-mail: chongwuz@usc.edu [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Seo, Jung-Woo T.; Hersam, Mark C. [Department of Materials Science and Engineering and Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States); Gui, Hui [Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089 (United States)

    2016-06-06

    In this paper, we report the high-performance radio-frequency transistors based on the single-walled semiconducting carbon nanotubes with a refined average diameter of ∼1.6 nm. These diameter-separated carbon nanotube transistors show excellent transconductance of 55 μS/μm and desirable drain current saturation with an output resistance of ∼100 KΩ μm. An exceptional radio-frequency performance is also achieved with current gain and power gain cut-off frequencies of 23 GHz and 20 GHz (extrinsic) and 65 GHz and 35 GHz (intrinsic), respectively. These radio-frequency metrics are among the highest reported for the carbon nanotube thin-film transistors. This study provides demonstration of radio frequency transistors based on carbon nanotubes with tailored diameter distributions, which will guide the future application of carbon nanotubes in radio-frequency electronics.

  13. Pulsed radio frequency radiation affects cognitive performance and the waking electroencephalogram.

    Science.gov (United States)

    Regel, Sabine J; Gottselig, Julie M; Schuderer, Jürgen; Tinguely, Gilberte; Rétey, Julia V; Kuster, Niels; Landolt, Hans-Peter; Achermann, Peter

    2007-05-28

    We investigated the effects of radio frequency electromagnetic fields on brain physiology. Twenty-four healthy young men were exposed for 30 min to pulse-modulated or continuous-wave radio frequency electromagnetic fields (900 MHz; peak specific absorption rate 1 W/kg), or sham exposed. During exposure, participants performed cognitive tasks. Waking electroencephalogram was recorded during baseline, immediately after, and 30 and 60 min after exposure. Pulse-modulated radio frequency electromagnetic field exposure reduced reaction speed and increased accuracy in a working-memory task. It also increased spectral power in the waking electroencephalogram in the 10.5-11 Hz range 30 min after exposure. No effects were observed for continuous-wave radio frequency electromagnetic fields. These findings provide further evidence for a nonthermal biological effect of pulsed radio frequency electromagnetic fields.

  14. Measuring the drinking behaviour of individual pigs housed in group using radio frequency identification (RFID).

    Science.gov (United States)

    Maselyne, J; Adriaens, I; Huybrechts, T; De Ketelaere, B; Millet, S; Vangeyte, J; Van Nuffel, A; Saeys, W

    2016-09-01

    Changes in the drinking behaviour of pigs may indicate health, welfare or productivity problems. Automated monitoring and analysis of drinking behaviour could allow problems to be detected, thus improving farm productivity. A high frequency radio frequency identification (HF RFID) system was designed to register the drinking behaviour of individual pigs. HF RFID antennas were placed around four nipple drinkers and connected to a reader via a multiplexer. A total of 55 growing-finishing pigs were fitted with radio frequency identification (RFID) ear tags, one in each ear. RFID-based drinking visits were created from the RFID registrations using a bout criterion and a minimum and maximum duration criterion. The HF RFID system was successfully validated by comparing RFID-based visits with visual observations and flow meter measurements based on visit overlap. Sensitivity was at least 92%, specificity 93%, precision 90% and accuracy 93%. RFID-based drinking duration had a high correlation with observed drinking duration (R 2=0.88) and water usage (R 2=0.71). The number of registrations after applying the visit criteria had an even higher correlation with the same two variables (R 2=0.90 and 0.75, respectively). There was also a correlation between number of RFID visits and number of observed visits (R 2=0.84). The system provides good quality information about the drinking behaviour of individual pigs. As health or other problems affect the pigs' drinking behaviour, analysis of the RFID data could allow problems to be detected and signalled to the farmer. This information can help to improve the productivity and economics of the farm as well as the health and welfare of the pigs.

  15. Hair removal using a combination radio-frequency and intense pulsed light source.

    Science.gov (United States)

    Yaghmai, Dina; Garden, Jerome M; Bakus, Aboneal D; Spenceri, Elizabeth A; Hruza, George J; Kilmer, Suzanne L

    2004-12-01

    The long-term removal of unwanted hair is achieved by many laser and intense pulse light sources. One limitation is the treatment of individuals with dark skin. The light energy with the current systems has to penetrate through the epidermis before being absorbed by the hair follicle. In individuals with dark skin the high melanin concentration in the epidermis absorbs high energies that can lead to complications. The objective of our study was to study a new system that combines optical energy, intense pulsed light (IPL), with radio frequency (RF). This allows for the use of less optical energy due to the addition of RF energy. The lower optical fluence allows for safer treatment of darker skin types. This was a multicenter study, in which 87 patients were enrolled. A single treatment was performed on a specified body site. Twenty-one of the 69 subjects that completed the study had skin types IV-VI. Each subject was evaluated at 1, 7, 30, and 90 days after the treatment session. Hair counts were significantly reduced from baseline after one treatment by an average of 46%. Individual patient data showed that the percentage in hair count reduction achieved ranged from 0 to 100%, with 43% of the patients having a 50% or greater decrease. The combination of optical energy and RF when delivered simultaneously achieves effective hair reduction with the use of less optical energy, allowing for the safe treatment of all skin types.

  16. Radio frequency coil technology for small-animal MRI.

    Science.gov (United States)

    Doty, F David; Entzminger, George; Kulkarni, Jatin; Pamarthy, Kranti; Staab, John P

    2007-05-01

    A review of the theory, technology, and use of radio frequency (RF) coils for small-animal MRI is presented. It includes a brief overview of MR signal-to-noise (S/N) analysis and discussions of the various coils commonly used in small-animal MR: surface coils, linear volume coils, birdcages, and their derivatives. The scope is limited to mid-range coils, i.e. coils where the product (fd) of the frequency f and the coil diameter d is in the range 2-30 MHz-m. Common applications include mouse brain and body coils from 125 to 750 MHz, rat body coils up to 500 MHz, and small surface coils at all fields. In this regime, all the sources of loss (coil, capacitor, sample, shield, and transmission lines) are important. All such losses may be accurately captured in some modern full-wave 3D electromagnetics software, and new simulation results are presented for a selection of surface coils using Microwave Studio 2006 by Computer Simulation Technology, showing the dramatic importance of the "lift-off effect". Standard linear circuit simulators have been shown to be useful in optimization of complex coil tuning and matching circuits. There appears to be considerable potential for trading S/N for speed using phased arrays, especially for a larger field of view. Circuit simulators are shown to be useful for optimal mismatching of ultra-low-noise preamps based on the enhancement-mode pseudomorphic high-electron-mobility transistor for optimal coil decoupling in phased arrays. Cryogenically cooled RF coils are shown to offer considerable opportunity for future gains in S/N in smaller samples.

  17. Nanoionics-Based Switches for Radio-Frequency Applications

    Science.gov (United States)

    Nessel, James; Lee, Richard

    2010-01-01

    Nanoionics-based devices have shown promise as alternatives to microelectromechanical systems (MEMS) and semiconductor diode devices for switching radio-frequency (RF) signals in diverse systems. Examples of systems that utilize RF switches include phase shifters for electronically steerable phased-array antennas, multiplexers, cellular telephones and other radio transceivers, and other portable electronic devices. Semiconductor diode switches can operate at low potentials (about 1 to 3 V) and high speeds (switching times of the order of nanoseconds) but are characterized by significant insertion loss, high DC power consumption, low isolation, and generation of third-order harmonics and intermodulation distortion (IMD). MEMS-based switches feature low insertion loss (of the order of 0.2 dB), low DC power consumption (picowatts), high isolation (>30 dB), and low IMD, but contain moving parts, are not highly reliable, and must be operated at high actuation potentials (20 to 60 V) generated and applied by use of complex circuitry. In addition, fabrication of MEMS is complex, involving many processing steps. Nanoionics-based switches offer the superior RF performance and low power consumption of MEMS switches, without need for the high potentials and complex circuitry necessary for operation of MEMS switches. At the same time, nanoionics-based switches offer the high switching speed of semiconductor devices. Also, like semiconductor devices, nanoionics-based switches can be fabricated relatively inexpensively by use of conventional integrated-circuit fabrication techniques. More over, nanoionics-based switches have simple planar structures that can easily be integrated into RF power-distribution circuits.

  18. Imaging Interplanetary CMEs at Radio Frequency From Solar Polar Orbit

    Science.gov (United States)

    Wu, Ji; Sun, Weiying; Zheng, Jianhua; Zhang, Cheng; Wang, Chi; Wang, C. B.; Wang, S.

    Coronal mass ejections (CMEs) are violent discharges of plasma and magnetic fields from the Sun's corona. They have come to be recognized as the major driver of physical conditions in the Sun-Earth system. Consequently, the detection of CMEs is important for un-derstanding and ultimately predicting space weather conditions. The Solar Polar Orbit Radio Telescope (SPORT) is a proposed mission to observe the propagation of interplanetary CMEs from solar polar orbit. The main payload (radio telescope) on board SPORT will be an in-terferometric imaging radiometer working at the meter wavelength band, which will follow the propagation of interplanetary CMEs from a distance of a few solar radii to near 1 AU from solar polar orbit. The SPORT spacecraft will also be equipped with a set of optical and in situ measurement instruments such as a EUV solar telescope, a solar wind plasma experiment, a solar wind ion composition instrument, an energetic particle detector, a wave detector, a mag-netometer and an interplanetary radio burst tracker. In this paper, we first describe the current shortage of interplanetary CME observations. Next, the scientific motivation and objectives of SPORT are introduced. We discuss the basic specifications of the main radio telescope of SPORT with reference to the radio emission mechanisms and the radio frequency band to be observed. Finally, we discuss the key technologies of the SPORT mission, including the con-ceptual design of the main telescope, the image retrieval algorithm and the solar polar orbit injection. Other payloads and their respective observation objectives are also briefly discussed. Key words: Interplanetary CMEs; Interferometric imaging; Solar polar orbit; Radiometer.

  19. Evaluating the Readability of Radio Frequency Identification for Construction Materials

    Directory of Open Access Journals (Sweden)

    Younghan Jung

    2017-01-01

    Full Text Available Radio Frequency Identification (RFID, which was originally introduced to improve material handling and speed production as part of supply chain management, has become a globally accepted technology that is now applied on many construction sites to facilitate real-time information visibility and traceability. This paper describes a senior undergraduate project for a Construction Management (CM program that was specifically designed to give the students a greater insight into technical research in the CM area. The students were asked to determine whether it would be possible to utilize an RFID system capable of tracking tagged equipment, personnel and materials across an entire construction site. This project required them to set up an experimental program, execute a series of experiments, analyze the results and summarize them in a report. The readability test was performed using an active Ultra-High frequency (UHF, 433.92 MHz RFID system with various construction materials, including metal, concrete, wood, plastic, and aluminum. The readability distance distances are measured for each of the six scenarios. The distance at which a tag was readable with no obstructions was found to be an average of 133.9m based on three measurements, with a standard deviation of 3.9m. This result confirms the manufacturer’s claimed distance of 137.2m. The RFID tag embedded under 50.8mm of concrete was readable for an average distance of only 12.2m, the shortest readable distance of any of the scenarios tested. At the end of the semester, faculty advisors held an open discussion session to gather feedback and elicit the students’ reflections on their research experiences, revealing that the students’ overall impressions of their undergraduate research had positively affected their postgraduate education plans.

  20. An analytical description of balanced steady-state free precession with finite radio-frequency excitation.

    Science.gov (United States)

    Bieri, Oliver

    2011-02-01

    Conceptually, the only flaw in the standard steady-state free precession theory is the assumption of quasi-instantaneous radio-frequency pulses, and 10-20% signal deviations from theory are observed for common balanced steady-state free precession protocols. This discrepancy in the steady-state signal can be resolved by a simple T(2) substitution taking into account reduced transverse relaxation effects during finite radio-frequency excitation. However, finite radio-frequency effects may also affect the transient phase of balanced steady-state free precession, its contrast or its spin-echo nature and thereby have an adverse effect on common steady-state free precession magnetization preparation methods. As a result, an in-depth understanding of finite radio-frequency effects is not only of fundamental theoretical interest but also has direct practical implications. In this article, an analytical solution for balanced steady-state free precession with finite radio-frequency pulses is derived for the transient phase (under ideal conditions) and in the steady state demonstrating that balanced steady-state free precession key features are preserved but revealing an unexpected dependency of finite radio-frequency effects on relaxation times for the transient decay. Finally, the mathematical framework reveals that finite radio-frequency theory can be understood as a generalization of alternating repetition time and fluctuating equilibrium steady-state free precession sequence schemes. Copyright © 2010 Wiley-Liss, Inc.

  1. [Microstrip antenna design and system research of radio frequency identification temperature sensor].

    Science.gov (United States)

    Yang, Hao; Yang, Xiaohe; Chen, Yuquan; Pan, Min

    2008-12-01

    Radio frequency identification sensor network, which is a product of integrating radio frequency identification (RFID) with wireless sensor network (WSN), is introduced in this paper. The principle of radio frequency identification sensor is analyzed, and the importance of the antenna is emphasized. Then three kinds of common antennae, namely coil antenna, dipole antenna and microstrip antenna, are discussed. Subsequently, according to requirement, we have designed a microstrip antenna in a wireless temperature-monitoring and controlling system. The measurement of factual effect showed the requirement was fulfilled.

  2. 78 FR 49529 - Radio Frequency Wireless Technology in Medical Devices; Guidance for Industry and Food and Drug...

    Science.gov (United States)

    2013-08-14

    ... 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... considerations related to the incorporation and integration of radio frequency (RF) wireless technology in...

  3. Mapping the Orion Molecular Cloud Complex in Radio Frequencies

    Science.gov (United States)

    Castelaz, Michael W.; Lemly, C.

    2013-01-01

    The purpose of this research project was to create a large-scale intensity map of the Orion Molecular Cloud Complex at a radio frequency of 1420 MHz. A mapping frequency of 1420 MHz was chosen because neutral hydrogen, which is the primary component of the Orion Molecular Complex, naturally emits radio waves at this frequency. The radio spectral data for this project were gathered using a 4.6-m radio telescope whose spectrometer was tuned to 1420 MHz and whose beam width was 2.7 degrees. The map created for this project consisted of an eight-by-eight grid centered on M42 spanning 21.6 degrees per side. The grid consisted of 64 individual squares spanning 2.7 degrees per side (corresponding to the beam width of the telescope). Radio spectra were recorded for each of these individual squares at an IF gain of 18. Each spectrum consisted of intensity on an arbitrary scale from 0 to 10 plotted as a function frequencies ranging from -400 kHz to +100 kHz around the origin of 1420 MHz. The data from all 64 radio spectra were imported into Wolfram Alpha, which was used to fit Gaussian functions to the data. The peak intensity and the frequency at which this peak intensity occurs could then be extracted from the Gaussian functions. Other helpful quantities that could be calculated from the Gaussian functions include flux (integral of Gaussian function over frequency range), average value of intensity (flux integral divided by frequency range), and half maximum of intensity. Because all of the radio spectra were redshifted, the velocities of the hydrogen gas clouds of the Orion Molecular Cloud Complex could be calculated using the Doppler equation. The data extracted from the Gaussian functions were then imported into Mathcad to create 2D grayscale maps with right ascension (RA) on the x-axis, declination on the y-axis, and intensity (or flux, etc.) represented on a scale from black to white (with white representing the highest intensities). These 2D maps were then imported

  4. The Radio Frequency Health Node Wireless Sensor System

    Science.gov (United States)

    Valencia, J. Emilio; Stanley, Priscilla C.; Mackey, Paul J.

    2009-01-01

    The Radio Frequency Health Node (RFHN) wireless sensor system differs from other wireless sensor systems in ways originally intended to enhance utility as an instrumentation system for a spacecraft. The RFHN can also be adapted to use in terrestrial applications in which there are requirements for operational flexibility and integrability into higher-level instrumentation and data acquisition systems. As shown in the figure, the heart of the system is the RFHN, which is a unit that passes commands and data between (1) one or more commercially available wireless sensor units (optionally, also including wired sensor units) and (2) command and data interfaces with a local control computer that may be part of the spacecraft or other engineering system in which the wireless sensor system is installed. In turn, the local control computer can be in radio or wire communication with a remote control computer that may be part of a higher-level system. The remote control computer, acting via the local control computer and the RFHN, cannot only monitor readout data from the sensor units but can also remotely configure (program or reprogram) the RFHN and the sensor units during operation. In a spacecraft application, the RFHN and the sensor units can also be configured more nearly directly, prior to launch, via a serial interface that includes an umbilical cable between the spacecraft and ground support equipment. In either case, the RFHN wireless sensor system has the flexibility to be configured, as required, with different numbers and types of sensors for different applications. The RFHN can be used to effect realtime transfer of data from, and commands to, the wireless sensor units. It can also store data for later retrieval by an external computer. The RFHN communicates with the wireless sensor units via a radio transceiver module. The modular design of the RFHN makes it possible to add radio transceiver modules as needed to accommodate additional sets of wireless sensor

  5. Endotoxin removal by radio frequency gas plasma (glow discharge)

    Science.gov (United States)

    Poon, Angela

    2011-12-01

    Contaminants remaining on implantable medical devices, even following sterilization, include dangerous fever-causing residues of the outer lipopolysaccharide-rich membranes of Gram-negative bacteria such as the common gut microorganism E. coli. The conventional method for endotoxin removal is by Food & Drug Administration (FDA)-recommended dry-heat depyrogenation at 250°C for at least 45 minutes, an excessively time-consuming high-temperature technique not suitable for low-melting or heat-distortable biomaterials. This investigation evaluated the mechanism by which E. coli endotoxin contamination can be eliminated from surfaces during ambient temperature single 3-minute to cumulative 15-minute exposures to radio-frequency glow discharge (RFGD)-generated residual room air plasmas activated at 0.1-0.2 torr in a 35MHz electrodeless chamber. The main analytical technique for retained pyrogenic bio-activity was the Kinetic Chromogenic Limulus Amebocyte Lysate (LAL) Assay, sufficiently sensitive to document compliance with FDA-required Endotoxin Unit (EU) titers less than 20 EU per medical device by optical detection of enzymatic color development corresponding to LAL Assay of sterile water extracts from both glass and Ge specimens. The Ge prism MAIR-IR measurements were repeated after employing 3-minute RFGD treatments sequentially for more than 10 cycles to observe removal of deposited matter that correlated with diminished EU titers. The results showed that 5 cycles, for a total exposure time of 15 minutes to low-temperature gas plasma, was sufficient to reduce endotoxin titers to below 0.05 EU/ml, and correlated with concurrent reduction of major endotoxin reference standard absorption bands at 3391 cm-1, 2887 cm-1, 1646 cm -1 1342 cm-1, and 1103 cm-1 to less than 0.05 Absorbance Units. Band depletion varied from 15% to 40% per 3-minute cycle of RFGD exposure, based on peak-to-peak analyses. In some cases, 100% of all applied biomass was removed within 5 sequential

  6. Radio-Frequency Tank Eigenmode Sensor for Propellant Quantity Gauging

    Science.gov (United States)

    Zimmerli, Gregory A.; Buchanan, David A.; Follo, Jeffrey C.; Vaden, Karl R.; Wagner, James D.; Asipauskas, Marius; Herlacher, Michael D.

    2010-01-01

    Although there are several methods for determining liquid level in a tank, there are no proven methods to quickly gauge the amount of propellant in a tank while it is in low gravity or under low-settling thrust conditions where propellant sloshing is an issue. Having the ability to quickly and accurately gauge propellant tanks in low-gravity is an enabling technology that would allow a spacecraft crew or mission control to always know the amount of propellant onboard, thus increasing the chances for a successful mission. The Radio Frequency Mass Gauge (RFMG) technique measures the electromagnetic eigenmodes, or natural resonant frequencies, of a tank containing a dielectric fluid. The essential hardware components consist of an RF network analyzer that measures the reflected power from an antenna probe mounted internal to the tank. At a resonant frequency, there is a drop in the reflected power, and these inverted peaks in the reflected power spectrum are identified as the tank eigenmode frequencies using a peak-detection software algorithm. This information is passed to a pattern-matching algorithm, which compares the measured eigenmode frequencies with a database of simulated eigenmode frequencies at various fill levels. A best match between the simulated and measured frequency values occurs at some fill level, which is then reported as the gauged fill level. The database of simulated eigenmode frequencies is created by using RF simulation software to calculate the tank eigenmodes at various fill levels. The input to the simulations consists of a fairly high-fidelity tank model with proper dimensions and including internal tank hardware, the dielectric properties of the fluid, and a defined liquid/vapor interface. Because of small discrepancies between the model and actual hardware, the measured empty tank spectra and simulations are used to create a set of correction factors for each mode (typically in the range of 0.999 1.001), which effectively accounts for

  7. 78 FR 43916 - Certain Radio Frequency Identification (RFID) Products and Components Thereof; Commission...

    Science.gov (United States)

    2013-07-22

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Radio Frequency Identification (RFID) Products and Components Thereof; Commission Determination Not To Review an Initial Determination Terminating Investigation Based on a Settlement Agreement...

  8. Photonic radio-frequency dissemination via optical fiber with high-phase stability.

    Science.gov (United States)

    Wang, Xiaocheng; Liu, Zhangweiyi; Wang, Siwei; Sun, Dongning; Dong, Yi; Hu, Weisheng

    2015-06-01

    We demonstrate a photonic radio-frequency transmission system via optical fiber. Optical radio-frequency signal is generated utilizing a Mach-Zehnder modulator based on double-side-band with carrier suppression modulation scheme. The phase error induced by optical fiber transmission is transferred to an intermediate frequency signal by the dual-heterodyne phase error transfer scheme, and then canceled by a phase locked loop. With precise phase compensation, a radio frequency with high-phase stability can be obtained at the remote end. We performed 20.07-GHz radio-frequency transfer over 100-km optical fiber, and achieved residual phase noise of -65  dBc/Hz at 1-Hz offset frequency, and the RMS timing jitter in the frequency range from 0.01 Hz to 1 MHz reaches 110 fs. The long-term frequency stability also achieves 8×10(-17) at 10,000 s averaging time.

  9. Radio-frequency transparent demodulation for broadband hybrid wireless-optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Sambaraju, Rakesh; Alemany, Ruben

    2010-01-01

    A novel demodulation technique which is transparent to radio-frequency (RF) carrier frequency is presented and experimentally demonstrated for multigigabit wireless signals. The presented demodulation technique employs optical single-sideband filtering, coherent detection, and baseband digital...

  10. A C-Band Radio Frequency Interference (RFI) Detection and Mitigation Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Radio Frequency Interference (RFI) can render microwave radiometer measurements useless. We propose a method and an architecture that can be used to identify sources...

  11. An L-Band Radio Frequency Interference (RFI) Detection and Mitigation Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Radio Frequency Interference (RFI) can render microwave radiometer measurements useless. We have proposed a method and an architecture that can be used to identify...

  12. Electromagnetic interference from radio frequency identification inducing potentially hazardous incidents in critical care medical equipment

    NARCIS (Netherlands)

    van der Togt, R.; van Lieshout, E.J.; Hensbroek, R.A.; 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

  13. Electromagnetic interference from radio frequency identification inducing potentially hazardous incidents in critical care medical equipment

    NARCIS (Netherlands)

    van der Togt, Remko; van Lieshout, Erik Jan; Hensbroek, Reinout; 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

  14. An Intelligent Traffic Flow Control System Based on Radio Frequency Identification and Wireless Sensor Networks

    National Research Council Canada - National Science Library

    Chao, Kuei-Hsiang; Chen, Pi-Yun

    2014-01-01

    This study primarily focuses on the use of radio frequency identification (RFID) as a form of traffic flow detection, which transmits collected information related to traffic flow directly to a control system through an RS232 interface...

  15. WindSat Radio-Frequency Interference Signature and Its Identification Over Land and Ocean

    National Research Council Canada - National Science Library

    Li, L; Gaiser, Peter W; Bettenhausen, Michael H; Johnston, William

    2006-01-01

    Radio-frequency interference (RFI) in the spaceborne multichannel radiometer data of WindSat and the Advanced Microwave Scanning Radiometer EOS is currently being detected using a spectral difference technique...

  16. First Demonstration of Electron Beam Generation and Characterization with an All Superconducting Radio-frequency (SRF) Photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Kamps, T; Barday, R; Jankowiak, A; Knobloch, J; Kugeler, O; Matveenko, A N; Neumann, A; Quast, T; Rudolph, J; Schubert, S G; Volker, J; Kneisel, P; Nietubyc, R; Sekutowicz, J K; Smedley, J; Volkov, V; Weinberg, G

    2011-09-01

    In preparation for a high brightness, high average current electron source for the energy-recovery linac BERLinPro an all superconducting radio-frequency photoinjector is now in operation at Helmholtz-Zentrum Berlin. The aim of this experiment is beam demonstration with a high brightness electron source able to generate sub-ps pulse length electron bunches from a superconducting (SC) cathode film made of Pb coated on the backwall of a Nb SRF cavity. This paper describes the setup of the experiment and first results from beam measurements.

  17. [Discussion on the electromagnetic compatibility testing and evaluation of radio frequency ablation catheter].

    Science.gov (United States)

    Wang, Yuji; Yang, Jiangang

    2014-11-01

    With the enforcement of YY 0505-2012, the testing items and evaluation points of radio frequency ablation catheter in electromagnetic compatibility field should be studied and discussed. Based on the requirements of relevant standards, this paper discusses on the testing items that should be applied and the evaluation points that should be focused on by analyzing the intended use and the structure of radio frequency ablation catheter, when it intends to apply registration individually with the basic knowledge of electromagnetic compatibility field.

  18. Numerical Modeling of The Electromagnetic Field Of Pine Plank In Radio Frequency Heating

    Directory of Open Access Journals (Sweden)

    LAZA (BULC Marcela

    2012-10-01

    Full Text Available This paper presents a study on the process of heating in radio frequency a pine plank in a „staggered-through field” applicator.The purpose of this study is to develop constructive solutions by controlling the value of the voltage applied, so that the material sujected to heating wouldn’t be damaged by temperature over 70 degreevalue, proving the advantage of using the method of heating dielectric materials in radio frequency field.

  19. Implementation of a Digital Radio Frequency Memory in a Xilinx Virtex-4 FPGA

    OpenAIRE

    Gustafsson, Kristian

    2005-01-01

    Digital Radio Frequency Memory (DRFM) is a technique widely used by the defense industry in, for example, electronic countermeasure equipment for generating false radar targets. The purpose of the DRFM technique is to use high-speed sampling to digitally store and recreate radio frequency and microwave signals. At Saab Bofors Dynamics AB the technique is used, among others, in the Electronic Warfare Simulator (ELSI). The DRFM technique is implemented in a full-custom ASIC circuit that has bee...

  20. Radio frequency identification-enabled capabilities in a healthcare context: An exploratory study.

    Science.gov (United States)

    Hornyak, Rob; Lewis, Mark; Sankaranarayan, Balaji

    2016-09-01

    Increasingly, the adoption and use of radio frequency identification systems in hospital settings is gaining prominence. However, despite the transformative impact that radio frequency identification has in healthcare settings, few studies have examined how and why this change may occur. The purpose of this study is to systematically understand how radio frequency identification can transform work practices in an operational process that directly impacts cost and operational efficiency and indirectly contributes to impacting patient safety and quality of care. We leverage an interdisciplinary framework to explore the contextual characteristics that shape the assimilation of radio frequency identification in healthcare settings. By linking the use of radio frequency identification with specific contextual dimensions in healthcare settings, we provide a data-driven account of how and why radio frequency identification can be useful in inventory management in this setting. In doing so, we also contribute to recent work by information systems scholars who argue for a reconfiguration of conventional assumptions regarding the role of technology in contemporary organizations. © The Author(s) 2015.

  1. Mission Assessment of the Faraday Accelerator with Radio-frequency Assisted Discharge (FARAD)

    Science.gov (United States)

    Dankanich, John W.; Polzin, Kurt A.

    2008-01-01

    Pulsed inductive thrusters have typically been considered for future, high-power, missions requiring nuclear electric propulsion. These high-power systems, while promising equivalent or improved performance over state-of-the-art propulsion systems, presently have no planned missions for which they are well suited. The ability to efficiently operate an inductive thruster at lower energy and power levels may provide inductive thrusters near term applicability and mission pull. The Faraday Accelerator with Radio-frequency Assisted Discharge concept demonstrated potential for a high-efficiency, low-energy pulsed inductive thruster. The added benefits of energy recapture and/or pulse compression are shown to enhance the performance of the pulsed inductive propulsion system, yielding a system that con compete with and potentially outperform current state-of-the-art electric propulsion technologies. These enhancements lead to mission-level benefits associated with the use of a pulsed inductive thruster. Analyses of low-power near to mid-term missions and higher power far-term missions are undertaken to compare the performance of pulsed inductive thrusters with that delivered by state-of-the-art and development-level electric propulsion systems.

  2. Radio Frequency Plasma Discharge Lamps for Use as Stable Calibration Light Sources

    Science.gov (United States)

    McAndrew, Brendan; Cooper, John; Arecchi, Angelo; McKee, Greg; Durell, Christopher

    2012-01-01

    Stable high radiance in visible and near-ultraviolet wavelengths is desirable for radiometric calibration sources. In this work, newly available electrodeless radio-frequency (RF) driven plasma light sources were combined with research grade, low-noise power supplies and coupled to an integrating sphere to produce a uniform radiance source. The stock light sources consist of a 28 VDC power supply, RF driver, and a resonant RF cavity. The RF cavity includes a small bulb with a fill gas that is ionized by the electric field and emits light. This assembly is known as the emitter. The RF driver supplies a source of RF energy to the emitter. In commercial form, embedded electronics within the RF driver perform a continual optimization routine to maximize energy transfer to the emitter. This optimization routine continually varies the light output sinusoidally by approximately 2% over a several-second period. Modifying to eliminate this optimization eliminates the sinusoidal variation but allows the output to slowly drift over time. This drift can be minimized by allowing sufficient warm-up time to achieve thermal equilibrium. It was also found that supplying the RF driver with a low-noise source of DC electrical power improves the stability of the lamp output. Finally, coupling the light into an integrating sphere reduces the effect of spatial fluctuations, and decreases noise at the output port of the sphere.

  3. Optical Measurements of Strong Radio-Frequency Fields Using Rydberg Atoms

    Science.gov (United States)

    Miller, Stephanie Anne

    There has recently been an initiative toward establishing atomic measurement standards for field quantities, including radio-frequency, millimeter-wave, and micro-wave electric fields. Current measurement standards are obtained using dipole antennas, which are fundamentally limited in frequency bandwidth (set by the physical size of the antenna) and accuracy (due to the metal perturbing the field during the measurement). Establishing an atomic standard rectifies these problems. My thesis work contributes to an ongoing effort towards establishing the viability of using Rydberg electromagnetically induced transparency (EIT) to perform atom-based measurements of radio-frequency (RF) fields over a wide range of frequencies and field strengths, focusing on strong-field measurements. Rydberg atoms are atoms with an electron excited to a high principal quantum number, resulting in a high sensitivity to an applied field. A model based on Floquet theory is implemented to accurately describe the observed atomic energy level shifts from which information about the field is extracted. Additionally, the effects due to the different electric field domains within the measurement volume are accurately modeled. Absolute atomic measurements of fields up to 296 V/m within a +/-0.35% relative uncertainty are demonstrated. This is the strongest field measured at the time of data publication. Moreover, the uncertainty is over an order of magnitude better than that of current standards. A vacuum chamber setup that I implemented during my graduate studies is presented and its unique components are detailed. In this chamber, cold-atom samples are generated and Rydberg atoms are optically excited within the ground-state sample. The Rydberg ion detection and imaging procedure are discussed, particularly the high magnification that the system provides. By analyzing the position of the ions, the spatial correlation g(2) (r) of Rydberg-atom distributions can be extracted. Aside from ion

  4. Relics in galaxy clusters at high radio frequencies

    Science.gov (United States)

    Kierdorf, M.; Beck, R.; Hoeft, M.; Klein, U.; van Weeren, R. J.; Forman, W. R.; Jones, C.

    2017-04-01

    Aims: We investigated the magnetic properties of radio relics located at the peripheries of galaxy clusters at high radio frequencies, where the emission is expected to be free of Faraday depolarization. The degree of polarization is a measure of the magnetic field compression and, hence, the Mach number. Polarization observations can also be used to confirm relic candidates. Methods: We observed three radio relics in galaxy clusters and one radio relic candidate at 4.85 and 8.35 GHz in total emission and linearly polarized emission with the Effelsberg 100-m telescope. In addition, we observed one radio relic candidate in X-rays with the Chandra telescope. We derived maps of polarization angle, polarization degree, and Faraday rotation measures. Results: The radio spectra of the integrated emission below 8.35 GHz can be well fitted by single power laws for all four relics. The flat spectra (spectral indices of 0.9 and 1.0) for the so-called Sausage relic in cluster CIZA J2242+53 and the so-called Toothbrush relic in cluster 1RXS 06+42 indicate that models describing the origin of relics have to include effects beyond the assumptions of diffuse shock acceleration. The spectra of the radio relics in ZwCl 0008+52 and in Abell 1612 are steep, as expected from weak shocks (Mach number ≈2.4). Polarization observations of radio relics offer a method of measuring the strength and geometry of the shock front. We find polarization degrees of more than 50% in the two prominent Mpc-sized radio relics, the Sausage and the Toothbrush, which are among the highest percentages of linear polarization detected in any extragalactic radio source to date. This is remarkable because the large beam size of the Effelsberg single-dish telescope corresponds to linear extensions of about 300 kpc at 8.35 GHz at the distances of the relics. The high degree of polarization indicates that the magnetic field vectors are almost perfectly aligned along the relic structure, as expected for shock

  5. Monitoring Pharmacy Student Adherence to World Health Organization Hand Hygiene Indications Using Radio Frequency Identification.

    Science.gov (United States)

    Decker, Andrew S; Cipriano, Gabriela C; Tsouri, Gill; Lavigne, Jill E

    2016-04-25

    Objective. To assess and improve student adherence to hand hygiene indications using radio frequency identification (RFID) enabled hand hygiene stations and performance report cards. Design. Students volunteered to wear RFID-enabled hospital employee nametags to monitor their adherence to hand-hygiene indications. After training in World Health Organization (WHO) hand hygiene methods and indications, student were instructed to treat the classroom as a patient care area. Report cards illustrating individual performance were distributed via e-mail to students at the middle and end of each 5-day observation period. Students were eligible for individual and team prizes consisting of Starbucks gift cards in $5 increments. Assessment. A hand hygiene station with an RFID reader and dispensing sensor recorded the nametag nearest to the station at the time of use. Mean frequency of use per student was 5.41 (range: 2-10). Distance between the student's seat and the dispenser was the only variable significantly associated with adherence. Student satisfaction with the system was assessed by a self-administered survey at the end of the study. Most students reported that the system increased their motivation to perform hand hygiene as indicated. Conclusion. The RFID-enabled hand hygiene system and benchmarking reports with performance incentives was feasible, reliable, and affordable. Future studies should record video to monitor adherence to the WHO 8-step technique.

  6. Assessment of radio frequency heating on composition, microstructure, flowability and rehydration characteristics of milk powder

    Directory of Open Access Journals (Sweden)

    Yu ZHONG

    2017-10-01

    Full Text Available Abstract Radio frequency heating (RFH provides higher efficiency and more uniform heating zone compared with conventional method. The aim of present work is to evaluate the effect of RFH (at 90 °C for 5 or 10 min on the changes in composition (protein oxidation and fat distribution, microstructure, flow characteristic and rehydration property of infant milk powder. The results indicate that the concentration of protein dityrosine was slightly enhanced, more free fat appeared on powder surfaces (> 50% increase, and porosity in powder matrix as tested by SEM was increased after RFH treatment. For powder flowability, raw sample had low cohesiveness (specific energy = 4.39 mJ/g, and RFH provided better flowability and decreased compressibility. Moreover, RFH had some negative impacts on wettability and solubility of powder particles with contact angle increase at least 5% and solubility decrease of 2%~4%, indicating worse rehydration abilities. Guggenheim-Anderson-de Boer (GAB model was applied to fit moisture vapor sorption isotherms, and longer RFH duration leading to higher c values (about 63% increase at 10 min. In addition, the RFH initiated browning reaction as CIE a* values increased from -1.8 to -1.3.

  7. First-principles calculations of niobium hydride formation in superconducting radio-frequency cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Denise C.; Cooley, Lance D.; Seidman, David N.

    2013-09-01

    Niobium hydride is suspected to be a major contributor to degradation of the quality factor of niobium superconducting radio-frequency (SRF) cavities. In this study, we connect the fundamental properties of hydrogen in niobium to SRF cavity performance and processing. We modeled several of the niobium hydride phases relevant to SRF cavities and present their thermodynamic, electronic, and geometric properties determined from calculations based on density-functional theory. We find that the absorption of hydrogen from the gas phase into niobium is exothermic and hydrogen becomes somewhat anionic. The absorption of hydrogen by niobium lattice vacancies is strongly preferred over absorption into interstitial sites. A single vacancy can accommodate six hydrogen atoms in the symmetrically equivalent lowest-energy sites and additional hydrogen in the nearby interstitial sites affected by the strain field: this indicates that a vacancy can serve as a nucleation center for hydride phase formation. Small hydride precipitates may then occur near lattice vacancies upon cooling. Vacancy clusters and extended defects should also be enriched in hydrogen, potentially resulting in extended hydride phase regions upon cooling. We also assess the phase changes in the niobium-hydrogen system based on charge transfer between niobium and hydrogen, the strain field associated with interstitial hydrogen, and the geometry of the hydride phases. The results of this study stress the importance of not only the hydrogen content in niobium, but also the recovery state of niobium for the performance of SRF cavities.

  8. Study of dual radio frequency capacitively coupled plasma: an analytical treatment matched to an experiment

    Science.gov (United States)

    Saikia, P.; Bhuyan, H.; Escalona, M.; Favre, M.; Wyndham, E.; Maze, J.; Schulze, J.

    2018-01-01

    The behavior of a dual frequency capacitively coupled plasma (2f CCP) driven by 2.26 and 13.56 MHz radio frequency (rf) source is investigated using an approach that integrates a theoretical model and experimental data. The basis of the theoretical analysis is a time dependent dual frequency analytical sheath model that casts the relation between the instantaneous sheath potential and plasma parameters. The parameters used in the model are obtained by operating the 2f CCP experiment (2.26 MHz + 13.56 MHz) in argon at a working pressure of 50 mTorr. Experimentally measured plasma parameters such as the electron density, electron temperature, as well as the rf current density ratios are the inputs of the theoretical model. Subsequently, a convenient analytical solution for the output sheath potential and sheath thickness was derived. A comparison of the present numerical results is done with the results obtained in another 2f CCP experiment conducted by Semmler et al (2007 Plasma Sources Sci. Technol. 16 839). A good quantitative correspondence is obtained. The numerical solution shows the variation of sheath potential with the low and high frequency (HF) rf powers. In the low pressure plasma, the sheath potential is a qualitative measure of DC self-bias which in turn determines the ion energy. Thus, using this analytical model, the measured values of the DC self-bias as a function of low and HF rf powers are explained in detail.

  9. Kinetic investigation of the ion angular distribution in capacitive radio-frequency plasmas

    Science.gov (United States)

    Shihab, Mohammed; Mussenbrock, Thomas

    2017-11-01

    One of the key parameters in the context of plasma assisted processing in semiconductor fabrication using capacitive radio-frequency plasmas is the ion flux distribution at the substrate. Whereas the ion energy distribution function determines the etching rate and selectivity, the ion angular distribution controls the etching profile. In this contribution, we reveal the effect of the ion flux and the sheath potential on the ion angular distribution and the direct ion heat flux at the bottom of etching profiles in geometrically symmetric plasma reactors. The ion angular distribution and the direct ion heat flux are calculated as a function of the sheath potential, the driving frequency, and the phase shift between the two distinct harmonics of the driving voltage of dual frequency discharges. For this task, self-consistent particle-in-cell simulations subject to Monte Carlo collision are carried out. The results from particle-in-cell simulations which are computationally very expensive are compared and verified with those from the novel ensemble-in-spacetime model. It is confirmed that increasing the voltage of the high-frequency component, the high-frequency component, and/or make a phase shift of π/2 between the dual frequency, narrow the ion angular distribution and increase the direct ion heat flux to the etching profile bottom. In all simulation cases, a correlation between the narrowing of the ion angular distribution and the increase of the sheath potential and the sheath ion flux is found.

  10. A Radio Frequency Radiation Exposure System for Rodents based on Reverberation Chambers.

    Science.gov (United States)

    Capstick, Myles; Kuster, Niels; Kuehn, Sven; Berdinas-Torres, Veronica; Gong, Yijian; Wilson, Perry; Ladbury, John; Koepke, Galen; McCormick, David L; Gauger, James; Melnick, Ronald L

    2017-08-01

    In this paper we present the novel design features, their technical implementation, and an evaluation of the radio Frequency (RF) exposure systems developed for the National Toxicology Program (NTP) of the National Institute of Environmental Health Sciences (NIEHS) studies on the potential toxicity and carcinogenicity of 2nd and 3rd generation mobile-phone signals. The system requirements for this 2-year NTP cancer bioassay study were the tightly-controlled lifetime exposure of rodents (1568 rats and 1512 mice) to three power levels plus sham simulating typical daily, and higher, exposures of users of GSM and CDMA (IS95) signals. Reverberation chambers and animal housing were designed to allow extended exposure time per day for free-roaming individually-housed animals. The performance of the chamber was characterized in terms of homogeneity, stirred to unstirred energy, efficiency. The achieved homogeneity was 0.59 dB and 0.48 dB at 900 and 1900 MHz respectively. The temporal variation in the electric field strength was optimized to give similar characteristics to that of the power control of a phone in a real network using the two stirrers. Experimental dosimetry was performed to validate the SAR sensitivity and determine the SAR uniformity throughout the exposure volume; SAR uniformities of 0.46 dB and 0.40 dB, respectively, for rats and mice were achieved.

  11. Capacitively coupled radio-frequency discharges in nitrogen at low pressures

    KAUST Repository

    Alves, Luís Lemos

    2012-07-06

    This paper uses experiments and modelling to study capacitively coupled radio-frequency (rf) discharges in pure nitrogen, at 13.56MHz frequency, 0.11 mbar pressures and 230W coupled powers. Experiments performed on two similar (not twin) setups, existing in the LATMOS and the GREMI laboratories, include electrical and optical emission spectroscopy (OES) measurements. Electrical measurements give the rf-applied and the direct-current-self-bias voltages, the effective power coupled to the plasma and the average electron density. OES diagnostics measure the intensities of radiative transitions with the nitrogen second-positive and first-negative systems, and with the 811.5 nm atomic line of argon (present as an actinometer). Simulations use a hybrid code that couples a two-dimensional time-dependent fluid module, describing the dynamics of the charged particles (electrons and positive ions N 2 + and N 4 + ), and a zero-dimensional kinetic module, describing the production and destruction of nitrogen (atomic and molecular) neutral species. The coupling between these modules adopts the local mean energy approximation to define spacetime-dependent electron parameters for the fluid module and to work out spacetime-averaged rates for the kinetic module. The model gives general good predictions for the self-bias voltage and for the intensities of radiative transitions (both average and spatially resolved), underestimating the electron density by a factor of 34. © 2012 IOP Publishing Ltd.

  12. 3C-SiC microdisk mechanical resonators with multimode resonances at radio frequencies

    Science.gov (United States)

    Lee, Jaesung; Zamani, Hamidrera; Rajgopal, Srihari; Zorman, Christian A.; X-L Feng, Philip

    2017-07-01

    We report on the design, modeling, fabrication and measurement of single-crystal 3C-silicon carbide (SiC) microdisk mechanical resonators with multimode resonances operating at radio frequencies (RF). These microdisk resonators (center-clamped on a vertical stem pedestal) offer multiple flexural-mode resonances with frequencies dependent on both disk and anchor dimensions. The resonators are made using a novel fabrication method comprised of focused ion beam nanomachining and hydroflouic : nitric : acetic (HNA) acid etching. Resonance peaks (in the frequency spectrum) are detected through laser-interferometry measurements. Resonators with different dimensions are tested, and multimode resonances, mode splitting, energy dissipation (in the form of quality factor measurement) are investigated. Further, we demonstrate a feedback oscillator based on a passive 3C-SiC resonator. This investigation provides important guidelines for microdisk resonator development, ranging from an analytical prediction of frequency scaling law to fabrication, suggesting RF microdisk resonators can be good candidates for future sensing applications in harsh environments.

  13. Beam emittance measurements and simulations of injector line for radio frequency quadrupole.

    Science.gov (United States)

    Mathew, Jose V; Rao, S V L S; Pande, Rajni; Singh, P

    2015-07-01

    A 400 keV deuteron (D(+)) radio frequency quadrupole (RFQ) accelerator has been designed, built, and commissioned at the Bhabha Atomic Research Centre, India. A beam line has been developed for injecting deuterons into the 400 keV RFQ. This comprises of a RF plasma ion source and a low energy beam transport (LEBT) system, consisting of two solenoid magnets and two steerer magnets. The ion source is characterized in terms of transverse beam emittance. A slit-wire scanner based emittance measurement setup has been developed for the transverse emittance measurements of H(+) and D(+) beams. The measured emittance values are found to be well within the acceptance value for the RFQ. These measured emittance parameters are used to optimize the solenoid fields in LEBT to match the beam from the ion source to RFQ. TRACEWIN simulation code is used for the beam transport simulations. The simulations show 99% transmission of D(+) beam through the RFQ, while 95% transmission has been measured experimentally.

  14. The Low-Frequency Environment of the Murchison Widefield Array: Radio-Frequency Interference Analysis and Mitigation

    Science.gov (United States)

    Offringa, A. R.; Wayth, R. B.; Hurley-Walker, N.; Kaplan, D. L.; Barry, N.; Beardsley, A. P.; Bell, M. E.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Callingham, J. R.; Cappallo, R. J.; Carroll, P.; Deshpande, A. A.; Dillon, J. S.; Dwarakanath, K. S.; Ewall-Wice, A.; Feng, L.; For, B.-Q.; Gaensler, B. M.; Greenhill, L. J.; Hancock, P.; Hazelton, B. J.; Hewitt, J. N.; Hindson, L.; Jacobs, D. C.; Johnston-Hollitt, M.; Kapińska, A. D.; Kim, H.-S.; Kittiwisit, P.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Morgan, J.; Neben, A. R.; Oberoi, D.; Ord, S. M.; Paul, S.; Pindor, B.; Pober, J. C.; Prabu, T.; Procopio, P.; Riding, J.; Udaya Shankar, N.; Sethi, S.; Srivani, K. S.; Staveley-Smith, L.; Subrahmanyan, R.; Sullivan, I. S.; Tegmark, M.; Thyagarajan, N.; Tingay, S. J.; Trott, C. M.; Webster, R. L.; Williams, A.; Williams, C. L.; Wu, C.; Wyithe, J. S.; Zheng, Q.

    2015-03-01

    The Murchison Widefield Array is a new low-frequency interferometric radio telescope built in Western Australia at one of the locations of the future Square Kilometre Array. We describe the automated radio-frequency interference detection strategy implemented for the Murchison Widefield Array, which is based on the aoflagger platform, and present 72-231 MHz radio-frequency interference statistics from 10 observing nights. Radio-frequency interference detection removes 1.1% of the data. Radio-frequency interference from digital TV is observed 3% of the time due to occasional ionospheric or atmospheric propagation. After radio-frequency interference detection and excision, almost all data can be calibrated and imaged without further radio-frequency interference mitigation efforts, including observations within the FM and digital TV bands. The results are compared to a previously published Low-Frequency Array radio-frequency interference survey. The remote location of the Murchison Widefield Array results in a substantially cleaner radio-frequency interference environment compared to Low-Frequency Array's radio environment, but adequate detection of radio-frequency interference is still required before data can be analysed. We include specific recommendations designed to make the Square Kilometre Array more robust to radio-frequency interference, including: the availability of sufficient computing power for radio-frequency interference detection; accounting for radio-frequency interference in the receiver design; a smooth band-pass response; and the capability of radio-frequency interference detection at high time and frequency resolution (second and kHz-scale respectively).

  15. Reconfigurable radio-frequency arbitrary waveforms synthesized in a silicon photonic chip.

    Science.gov (United States)

    Wang, Jian; Shen, Hao; Fan, Li; Wu, Rui; Niu, Ben; Varghese, Leo T; Xuan, Yi; Leaird, Daniel E; Wang, Xi; Gan, Fuwan; Weiner, Andrew M; Qi, Minghao

    2015-01-12

    Photonic methods of radio-frequency waveform generation and processing can provide performance advantages and flexibility over electronic methods due to the ultrawide bandwidth offered by the optical carriers. However, bulk optics implementations suffer from the lack of integration and slow reconfiguration speed. Here we propose an architecture of integrated photonic radio-frequency generation and processing and implement it on a silicon chip fabricated in a semiconductor manufacturing foundry. Our device can generate programmable radio-frequency bursts or continuous waveforms with only the light source, electrical drives/controls and detectors being off-chip. It modulates an individual pulse in a radio-frequency burst within 4 ns, achieving a reconfiguration speed three orders of magnitude faster than thermal tuning. The on-chip optical delay elements offer an integrated approach to accurately manipulating individual radio-frequency waveform features without constraints set by the speed and timing jitter of electronics, and should find applications ranging from high-speed wireless to defence electronics.

  16. Slow Radio-Frequency Processing of Large Oil Shale Volumes to Produce Petroleum-Like Shale Oil

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, A K

    2003-08-20

    A process is proposed to convert oil shale by radio frequency heating over a period of months to years to create a product similar to natural petroleum. Electrodes would be placed in drill holes, either vertical or horizontal, and a radio frequency chosen so that the penetration depth of the radio waves is of the order of tens to hundreds of meters. A combination of excess volume production and overburden compaction drives the oil and gas from the shale into the drill holes, where it is pumped to the surface. Electrical energy for the process could be provided initially by excess regional capacity, especially off-peak power, which would generate {approx}3 x 10{sup 5} bbl/day of synthetic crude oil, depending on shale grade. The electricity cost, using conservative efficiency assumptions, is $4.70 to $6.30/bbl, depending on grade and heating rate. At steady state, co-produced gas can generate more than half the electric power needed for the process, with the fraction depending on oil shale grade. This would increase production to 7.3 x 10{sup 5} bbl/day for 104 l/Mg shale and 1.6 x 10{sup 6} bbl/day for 146 l/Mg shale using a combination of off-peak power and power from co-produced gas.

  17. Diagnostic of capacitively coupled radio frequency plasma from electrical discharge characteristics: comparison with optical emission spectroscopy and fluid model simulation

    Science.gov (United States)

    Xiang, HE; Chong, LIU; Yachun, ZHANG; Jianping, CHEN; Yudong, CHEN; Xiaojun, ZENG; Bingyan, CHEN; Jiaxin, PANG; Yibing, WANG

    2018-02-01

    The capacitively coupled radio frequency (CCRF) plasma has been widely used in various fields. In some cases, it requires us to estimate the range of key plasma parameters simpler and quicker in order to understand the behavior in plasma. In this paper, a glass vacuum chamber and a pair of plate electrodes were designed and fabricated, using 13.56 MHz radio frequency (RF) discharge technology to ionize the working gas of Ar. This discharge was mathematically described with equivalent circuit model. The discharge voltage and current of the plasma were measured at different pressures and different powers. Based on the capacitively coupled homogeneous discharge model, the equivalent circuit and the analytical formula were established. The plasma density and temperature were calculated by using the equivalent impedance principle and energy balance equation. The experimental results show that when RF discharge power is 50–300 W and pressure is 25–250 Pa, the average electron temperature is about 1.7–2.1 eV and the average electron density is about 0.5 × 1017–3.6 × 1017 m‑3. Agreement was found when the results were compared to those given by optical emission spectroscopy and COMSOL simulation.

  18. Assessment of Radio Frequency Propagation in a Naval Shipboard Environment

    National Research Council Canada - National Science Library

    Estes, Daniel

    2001-01-01

    .... The internal volume of a combat ship is a generally un-studied wireless environment. While a preliminary study demonstrated that radio energy can be radiated and received from compartment to compartment (room to room...

  19. Prototype superconducting radio-frequency cavity for LEP

    CERN Multimedia

    1985-01-01

    This niobium superconducting cavity was part of the prototype stages for an upgrade to LEP, known as LEP-2. Superconducting cavities would eventually replace the traditional copper cavities and allow beam energies of 100 GeV.

  20. Possible Explanation for Cancer in Rats due to Cell Phone Radio Frequency Radiation

    Science.gov (United States)

    Feldman, Bernard J.

    Very recently, the National Toxicology Program reported a correlation between exposure to whole body 900 MHz radio frequency radiation and cancer in the brains and hearts of Sprague Dawley male rats. Assuming that the National Toxicology Program is statistically significant, I propose the following explanation for these results. The neurons around the brain and heart form closed electrical circuits and, following Faraday's Law, 900 MHz radio frequency radiation induces 900 MHz electrical currents in these neural circuits. In turn, these 900 MHz currents in the neural circuits generate sufficient localized heat in the neural cells to shift the equilibrium concentration of carcinogenic radicals to higher levels and thus, to higher incidences of cancer.

  1. Radio-frequency reflectometry on an undoped AlGaAs/GaAs single electron transistor

    DEFF Research Database (Denmark)

    MacLeod, S. J.; See, A. M.; Keane, Z. K.

    2014-01-01

    Radio frequency reflectometry is demonstrated in a sub-micron undoped AlGaAs/GaAs device. Undoped single electron transistors (SETs) are attractive candidates to study single electron phenomena, due to their charge stability and robust electronic properties after thermal cycling. However, these d......Radio frequency reflectometry is demonstrated in a sub-micron undoped AlGaAs/GaAs device. Undoped single electron transistors (SETs) are attractive candidates to study single electron phenomena, due to their charge stability and robust electronic properties after thermal cycling. However...

  2. Development of a novel radio-frequency negative hydrogen ion source in conically converging configuration.

    Science.gov (United States)

    Jung, B K; Dang, J J; An, Y H; Chung, K J; Hwang, Y S

    2014-02-01

    Volume-produced negative ion source still requires enhancement of current density with lower input RF (radio-frequency) power in lower operating pressure for various applications. To confirm recent observation of efficient negative ion production with a short cylindrical chamber with smaller effective plasma size, the RF-driven transformer-coupled plasma H(-) ion source at Seoul National University is modified by adopting a newly designed quartz RF window to reduce the chamber length. Experiments with the reduced chamber length show a few times enhancement of H(-) ion beam current compared to that extracted from the previous chamber design, which is consistent with the measured H(-) ion population. Nevertheless, decrease in H(-) ion beam current observed in low pressure regime below ∼5 mTorr owing to insufficient filtering of high energy electrons in the extraction region needs to be resolved to address the usefulness of electron temperature control by the change of geometrical configuration of the discharge chamber. A new discharge chamber with conically converging configuration has been developed, in which the chamber diameter decreases as approaching to the extraction region away from the planar RF antenna such that stronger filter magnetic field can be utilized to prohibit high energy electrons from transporting to the extraction region. First experimental results for the H(-) ion beam extraction with this configuration show that higher magnetic filter field makes peak negative beam currents happen in lower operating pressure. However, overall decrease in H(-) ion beam current due to the change of chamber geometry still requires further study of geometrical effect on particle transport and optimization of magnetic field in this novel configuration.

  3. 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...

  4. Characterization of an Outdoor Ambient Radio Frequency Environment

    Science.gov (United States)

    2016-02-16

    Department of Defense (DOD) standard for electromagnetic interference (EMI) measurements in an anechoic (i.e., non-echoing) chamber ), and CISPR 162 (the...closed-loop laboratory or an isolated anechoic chamber environment. Although this TOP addresses only the characterization of the ambient RF environment...systems are initially tested in an anechoic chamber , with low ambient RF energy present. These systems transition to open-air facilities to verify

  5. A New Laboratory Radio Frequency Identification (RFID System for Behavioural Tracking of Marine Organisms

    Directory of Open Access Journals (Sweden)

    Francesc Sardà

    2011-10-01

    Full Text Available Radio frequency identification (RFID devices are currently used to quantify several traits of animal behaviour with potential applications for the study of marine organisms. To date, behavioural studies with marine organisms are rare because of the technical difficulty of propagating radio waves within the saltwater medium. We present a novel RFID tracking system to study the burrowing behaviour of a valuable fishery resource, the Norway lobster (Nephrops norvegicus L.. The system consists of a network of six controllers, each handling a group of seven antennas. That network was placed below a microcosm tank that recreated important features typical of Nephrops’ grounds, such as the presence of multiple burrows. The animals carried a passive transponder attached to their telson, operating at 13.56 MHz. The tracking system was implemented to concurrently report the behaviour of up to three individuals, in terms of their travelled distances in a specified unit of time and their preferential positioning within the antenna network. To do so, the controllers worked in parallel to send the antenna data to a computer via a USB connection. The tracking accuracy of the system was evaluated by concurrently recording the animals’ behaviour with automated video imaging. During the two experiments, each lasting approximately one week, two different groups of three animals each showed a variable burrow occupancy and a nocturnal displacement under a standard photoperiod regime (12 h light:12 h dark, measured using the RFID method. Similar results were obtained with the video imaging. Our implemented RFID system was therefore capable of efficiently tracking the tested organisms and has a good potential for use on a wide variety of other marine organisms of commercial, aquaculture, and ecological interest.

  6. A new laboratory radio frequency identification (RFID) system for behavioural tracking of marine organisms.

    Science.gov (United States)

    Aguzzi, Jacopo; Sbragaglia, Valerio; Sarriá, David; García, José Antonio; Costa, Corrado; del Río, Joaquín; Mànuel, Antoni; Menesatti, Paolo; Sardà, Francesc

    2011-01-01

    Radio frequency identification (RFID) devices are currently used to quantify several traits of animal behaviour with potential applications for the study of marine organisms. To date, behavioural studies with marine organisms are rare because of the technical difficulty of propagating radio waves within the saltwater medium. We present a novel RFID tracking system to study the burrowing behaviour of a valuable fishery resource, the Norway lobster (Nephrops norvegicus L.). The system consists of a network of six controllers, each handling a group of seven antennas. That network was placed below a microcosm tank that recreated important features typical of Nephrops' grounds, such as the presence of multiple burrows. The animals carried a passive transponder attached to their telson, operating at 13.56 MHz. The tracking system was implemented to concurrently report the behaviour of up to three individuals, in terms of their travelled distances in a specified unit of time and their preferential positioning within the antenna network. To do so, the controllers worked in parallel to send the antenna data to a computer via a USB connection. The tracking accuracy of the system was evaluated by concurrently recording the animals' behaviour with automated video imaging. During the two experiments, each lasting approximately one week, two different groups of three animals each showed a variable burrow occupancy and a nocturnal displacement under a standard photoperiod regime (12 h light:12 h dark), measured using the RFID method. Similar results were obtained with the video imaging. Our implemented RFID system was therefore capable of efficiently tracking the tested organisms and has a good potential for use on a wide variety of other marine organisms of commercial, aquaculture, and ecological interest.

  7. Characterizing L-band Radio-Frequency Interference (RFI) Using SMAP Microwave Radiometer Data

    Science.gov (United States)

    Mohammed, P.; Piepmeier, J. R.; Bringer, A.; Johnson, J. T.; Soldo, Y.; de Matthaeis, P.

    2016-12-01

    The L-band microwave radiometer on NASA's Soil Moisture Active Passive (SMAP) satellite measures electromagnetic radiation upwelling from Earth within the 1400-1427 MHz band. This relatively low microwave frequency is used to achieve penetration through vegetation and first few centimeters of soil. This frequency band is specifically selected, however, because it is exclusively allocated, on a primary basis, to passive sensing in the Earth Exploration Satellite and Radio Astronomy Services by international treaty. Thus, local administrations prohibit intentional transmissions within the band, and any non-natural signal in this band is considered to be radio-frequency interference (RFI). The SMAP radiometer has an advanced radiometer receiver providing time, frequency, polarization, and statistical diversity information on observed signals for RFI detection and filtering. Here we use this signal information to characterize the RFI environmental on local, regional, and global bases. RFI environment assessment is of interest for several reasons: 1) Reporting instances of interference harmful to SMAP performance to the appropriate regulators; 2) Informing spectrum managers and regulators of the state of the spectrum; and 3) Alerting SMAP users and future developers of trouble spots. We find the RF environment is highly variable around the globe. Global maps of RFI rate-of-occurrence exhibit a contrast in detected RFI between Eastern and Western Hemispheres and between Northern and Southern Hemispheres. Peak-hold maps show both isolated and distributed regions of severe RFI, some of which correspond to populated areas and others to geographically isolated long-range radars. Maps of kurtosis-excess reveal much RFI likely due to terrestrial radar systems, although other analysis indicates proliferation of low-level non-radar sources. In one case of intense RFI there is no kurtosis-excess indicating noise-like behavior due to either the use advanced digital modulation

  8. Effects of 1.84 GHz radio-frequency electromagnetic field on sperm ...

    African Journals Online (AJOL)

    sunny t

    Full Length Research Paper. Effects of 1.84 GHz radio-frequency electromagnetic field on sperm maturation in epididymis micro- environment. Guangzhou An1*, Jing Li1, Shenglong Xu1, Tao Zhao1, Kangchu Li1, Jiajin Lin1, Yan Zhou1,. Lihua Zeng2, Guozhen Guo2 and Guirong Ding1. 1Department of Radiation Biology, ...

  9. The Combined Effects of Radio Frequency and Gamma Irradiation on P-Channel MOSFETS

    Science.gov (United States)

    2010-09-01

    were further demonstrated. The MOSFET replaced the Bipolar Junction Transistor ( BJT ) (invented in 1945 at Bell Laboratories) in most electronic...voltage of metal oxide semiconductor field effect transistors . The combined effects of gigahertz radio frequency waves and gamma irradiation on...semiconductor field effect transistor (MOSFET) is a common component in many electronic devices including cellular telephones, communication systems, and

  10. Improved Wireless Security through Physical Layer Protocol Manipulation and Radio Frequency Fingerprinting

    Science.gov (United States)

    2014-09-18

    deception is reminiscent of firewall-based obstructions to nmap operating system fingerprinting [KS05]. Some arbitrary waveform generators and software... fingerprinting experiments due to their widespread use in critical infrastructure (CI) and supervisory control and data acquistion (SCADA) applications and...IMPROVEDWIRELESS SECURITY THROUGH PHYSICAL LAYER PROTOCOL MANIPULATION AND RADIO FREQUENCY FINGERPRINTING DISSERTATION Benjamin W. Ramsey, Captain

  11. Industrial-scale radio frequency treatments for insect control in lentils

    Science.gov (United States)

    Radio frequency (RF) treatments are considered to be a potential postharvest technology for disinfesting legumes of internal seed pests such as the cowpea weevil. After treatment protocols are shown to control postharvest insects without significant quality degradation, it is important to scale-up l...

  12. CoSMOS: Performance of Kurtosis Algorithm for Radio Frequency Interference Detection and Mitigation

    DEFF Research Database (Denmark)

    Misra, Sidharth; Kristensen, Steen Savstrup; Skou, Niels

    2007-01-01

    The performance of a previously developed algorithm for Radio Frequency Interference (RFI) detection and mitigation is experimentally evaluated. Results obtained from CoSMOS, an airborne campaign using a fully polarimetric L-band radiometer are analyzed for this purpose. Data is collected using two...

  13. Determining radio frequency heating uniformity of mixed beans during disinfestation treatments

    Science.gov (United States)

    Since chickpeas and lentils are difficulty to artificially infest with live insects for radio frequency (RF) treatment validation, black-eyed peas and mung beans were selected to infest with insects before mixing with chickpeas and lentils. Temperature difference between black-eyed pea and chickpea ...

  14. Epiphysiodesis Made with Radio Frequency Ablation: First Results from a Pilot Study

    DEFF Research Database (Denmark)

    Shiguetomi Medina, Juan Manuel; Rahbek, Ole; Stødkilde-Jørgensen, Hans

    to the surrounding cartilage structures was found. The animals could walk normally after the anesthesia and no signs of pain or discomfort were presented during the follow-up period. Conclusions Epiphysiodesis using radio frequency ablation is an innovative technique that may represent an alternative way...

  15. Ultracold atoms in radio-frequency dressed potentials beyond the rotating-wave approximation

    DEFF Research Database (Denmark)

    Hofferberth, S.; Fischer, B.; Schumm, Thorsten

    2007-01-01

    We study dressed Bose-Einstein condensates in an atom chip radio-frequency trap. We show that in this system sufficiently strong dressing can be achieved to cause the widely used rotating-wave approximation (RWA) to break down. We present a full calculation of the atom-field coupling which shows...

  16. Radio Frequency Heat Treatments to Disinfest Dried Pulses of Cowpea Weevil

    Science.gov (United States)

    To explore the potential of radio frequency (RF) heat treatments as an alternative to chemical fumigants for disinfestation of dried pulses, the relative heat tolerance and dielectric properties of different stages of the cowpea weevil (Callosobruchus maculatus) was determined. Among the immature st...

  17. Effect of thermal and radio frequency electric fields treatments on Escherichia coli bacteria in apple juice

    Science.gov (United States)

    The need for a non-thermal intervention technology that can achieve microbial safety without altering nutritional quality of liquid foods led to the development of the radio frequency electric fields (RFEF) process. However, insight into the mechanism of bacterial inactivation by this technology is ...

  18. Epiphysiodesis Made with Radio Frequency Ablation: First Results From a Pilot Study

    DEFF Research Database (Denmark)

    Shiguetomi Medina, Juan Manuel; Gottliebsen, Martin; Rahbek, Ole

    the procedure and 12 weeks later. The length of both tibiae was measured. Both legs were equal at the beginning of the study and there was a leg length difference of around 4mm at the end. No damage to the surrounding cartilage structures was found. Epiphysiodesis using radio frequency ablation is an innovative...

  19. Inactivation of Lactobacillus plantarum in apple cider using radio frequency electric fields

    Science.gov (United States)

    Radio frequency electric fields (RFEF) processing is effective at inactivating Gram negative bacteria in fruit juices at moderately low temperatures, but has yet to be shown to be effective at reducing Gram positive bacteria. Lactobacillus plantarum ATCC 49445, a Gram positive bacterium, was inocula...

  20. Dielectric properties of dried vegetable powders and their temperature profile during radio frequency heating

    Science.gov (United States)

    Recently, Salmonella contamination was identified in low-moisture foods including dried vegetable powder. Radio Frequency (RF) dielectric heating is a potential alternative pasteurization method with short heating time. Dielectric properties of broccoli powder with 6.9, 9.1, 12.2, and 14.9%, w. b....

  1. Detection of radio-frequency interference in microwave radiometers using spectral kurtosis

    DEFF Research Database (Denmark)

    Søbjærg, Sten Schmidl; Svoboda, Jan; Balling, Jan E.

    2012-01-01

    This paper describes the spectral kurtosis detector as an additional indicator for radio frequency interference, RFI in passive remote sensing systems. The estimator is based on continuous Fast Fourier Transformation of samples, followed by evaluation of each frequency bin in subsequent data blocks...

  2. 77 FR 67833 - Certain Radio Frequency Integrated Circuits and Devices Containing Same; Notice of Commission...

    Science.gov (United States)

    2012-11-14

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Radio Frequency Integrated Circuits and Devices Containing Same; Notice of Commission Determination Not To Review an Initial Determination Terminating the Investigation in its Entirety AGENCY: U.S...

  3. Determining radio frequency heating uniformity of mixed beans for disinfestation treatments

    Science.gov (United States)

    Chickpeas and lentils are two important legumes grown in the US and need phytosanitary treatments before exportation, but it is difficult to artificially infest them with live cowpea weevil for radio frequency (RF) treatment validation. To evaluate the more readily infested black-eyed peas and mung ...

  4. Gold Nanoparticle-Based Sensors Activated by External Radio Frequency Fields

    DEFF Research Database (Denmark)

    Della Vedova, Paolo; Ilieva, Mirolyuba; Zhurbenko, Vitaliy

    2015-01-01

    A novel molecular beacon (a nanomachine) is constructed that can be actuated by a radio frequency (RF) field. The nanomachine consists of the following elements arranged in molecular beacon configuration: a gold nanoparticle that acts both as quencher for fluorescence and a localized heat source...

  5. The Diffusion and Impact of Radio Frequency Identification in Supply Chains: A Multi-Method Approach

    Science.gov (United States)

    Wu, Xiaoran

    2012-01-01

    As a promising and emerging technology for supply chain management, Radio Frequency Identification (RFID) is a new alternative to existing tracking technologies and also allows a range of internal control and supply chain coordination. RFID has generated a significant amount of interest and activities from both practitioners and researchers in…

  6. Developing hot air assisted radio frequency drying for in-shell Macadamia nuts

    Science.gov (United States)

    Dehydration offers a means of preserving foods in a stable and safe condition as it reduces water activity and extends shelf-life of perishable agricultural products. The purpose of this study was to develop radio frequency (RF) drying protocols for in-shell macadamia nuts based on conventional hot ...

  7. Thermal Injury in Human Subjects Due to 94-GHz Radio Frequency Radiation Exposures

    Science.gov (United States)

    2016-02-24

    Dynamics Information Technology Jeffrey S. Eggers Bioeffects Division Veterinary Sciences Branch Philip E. Tobin Bioeffects...Directorate, Bioeffects Division, Veterinary Sciences Branch and Radio Frequency Bioeffects Branch (711 HPW/RHDV and 711 HPW/RHDR) 4141 Petroleum Road...Methodology ......................................................................................... 2 2.3 Pathology

  8. The design of a radio frequency quadrupole LINAC for the RIB ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 59; Issue 6. The design of a radio frequency quadrupole LINAC for the RIB project at VECC Kolkata. V Banerjee Alok Chakrabarti ... for rf structure design study. The beam dynamics and rf-structure design along with the results of the cold model tests will be presented.

  9. MARINER 9 SPACE PROBE ATOP ATLAS CENTAUR UNDERGOES RADIO FREQUENCY INTERFERENCE TESTS

    Science.gov (United States)

    1971-01-01

    An Atlas-Centaur rocket undergoes radio frequency interference tests at Cape Kennedy's Complex 36B prior to launch to Mars. The spacecraft was launched on a five and one-half month journey to mars, where it will enter orbit and return data about that planet's surface and atmosphere. Launch took place at 6:23 p.m. EDT, May 30, 1971.

  10. System Control Applications of Low-Power Radio Frequency Devices

    Science.gov (United States)

    van Rensburg, Roger

    2017-09-01

    This paper conceptualizes a low-power wireless sensor network design for application employment to reduce theft of portable computer devices used in educational institutions today. The aim of this study is to design and develop a reliable and robust wireless network that can eradicate accessibility of a device’s human interface. An embedded system supplied by an energy harvesting source, installed on the portable computer device, may represent one of multiple slave nodes which request regular updates from a standalone master station. A portable computer device which is operated in an undesignated area or in a field perimeter where master to slave communication is restricted, indicating a possible theft scenario, will initiate a shutdown of its operating system and render the device unusable. Consequently, an algorithm in the device firmware may ensure the necessary steps are executed to track the device, irrespective whether the device is enabled. Design outcomes thus far indicate that a wireless network using low-power embedded hardware, is feasible for anti-theft applications. By incorporating one of the latest Bluetooth low-energy, ANT+, ZigBee or Thread wireless technologies, an anti-theft system may be implemented that has the potential to reduce major portable computer device theft in institutions of digitized learning.

  11. Hydroxyapatite thin films grown by pulsed laser deposition and radio-frequency magnetron sputtering: comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Nelea, V.; Morosanu, C.; Iliescu, M.; Mihailescu, I.N

    2004-04-30

    Hydroxyapatite (HA) thin films for applications in the biomedical field were grown by pulsed laser deposition (PLD) and radio-frequency magnetron sputtering (RF-MS) techniques. The depositions were performed from pure hydroxyapatite targets on Ti-5Al-2.5Fe (TiAlFe) alloys substrates. In order to prevent the HA film penetration by Ti atoms or ions diffused from the Ti-based alloy during and after deposition, the substrates were pre-coated with a thin buffer layer of TiN. In both cases, TiN was introduced by reactive PLD from TiN targets in low-pressure N{sub 2}. The PLD films were grown in vacuum onto room temperature substrates. The RF-MS films were deposited in low-pressure argon on substrates heated at 550 deg. C. The initially amorphous PLD thin films were annealed at 550 deg. C for 1 h in ambient air in order to restore the initial crystalline structure of HA target. The thickness of the PLD and RF-MS films were {approx}1 {mu}m and {approx}350 nm, respectively. All films were structurally studied by scanning electron microscopy (SEM), grazing incidence X-ray diffraction (GIXRD), energy dispersive X-ray spectrometry (EDS) and white light confocal microscopy (WLCM). The mechanical properties of the films were tested by Berkovich nano-indentation. Both PLD and RF-MS films mostly contain HA phase and exhibit good mechanical characteristics. Peaks of CaO were noticed as secondary phase in the GIXRD patterns only for RF-MS films. By its turn, the sputtered films were smoother as compared to the ones deposited by PLD (50 nm versus 250 nm average roughness). The RF-MS films were harder, more mechanically resistant and have a higher Young modulus.

  12. Structural and optical properties of Al/ZnO thin films deposited by radio frequency sputtering

    Science.gov (United States)

    Osanyinlusi, O.; Mukolu, A. I.; Zebaze Kana, M. G.

    2016-09-01

    The effects of annealing temperature and variation of sample thickness on the structural and optical properties of zinc oxide thin films with aluminium contact (Al/ZnO) have been investigated. The study involved the synthesis of a bilayer thin film of Al/ZnO with varied thicknesses on a glass slide substrate by using radio frequency magnetron sputtering deposition technique. 99.99% pure ZnO and aluminium were used as the sputtering target. The films were then annealed in vacuum at annealing temperatures of 200 °C and 400 °C. The structural and optical properties of Al/ZnO thin films grown were characterized by x-ray diffraction (XRD) and optical measurements respectively. The results obtained from the XRD patterns showed that Al/ZnO films (both as-deposited and annealed), exhibits a crystalline structure with (002) preferred orientation. The peak intensity of the preferred plane increases as the annealing temperature increases. The optical studies of the Al/ZnO films showed a maximum value of transmittance ranging from 82% to 91% depending on the condition of the films. A decrease in transmittance as the thickness of the films increases was observed. The transmittance also increased with increasing annealing temperature. The energy gaps (E g) were determined from the transmittance data and found to be in the range 3.73-3.83 eV. The results obtained from the experiment also show that the optical band gap increases as the thickness and annealing temperature increase.

  13. Radio frequency models of novae in eruption. I. The free-free process in bipolar morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, V. A. R. M.; Simon, T.; Woudt, P. A. [Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Chomiuk, L. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Munari, U. [NAF Astronomical Observatory of Padova, I-36012 Asiago (VI) (Italy); Steffen, W. [Instituto de Astronomía, Universidad Nacional Autónoma de México, C.P. 22860, Ensenada (Mexico); Koning, N. [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); O' Brien, T. J. [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom); Bode, M. F., E-mail: vribeiro@ast.uct.ac.za [Astrophysics Research Institute, Liverpool John Moores University, IC2 Liverpool Science Park, 146 Brownlow Hill, L3 5RF (United Kingdom)

    2014-09-01

    Observations of novae at radio frequencies provide us with a measure of the total ejected mass, density profile, and kinetic energy of a nova eruption. The radio emission is typically well characterized by the free-free emission process. Most models to date have assumed spherical symmetry for the eruption, although for as long as there have been radio observations of these systems, it has been known that spherical eruptions are too simplistic a geometry. In this paper, we build bipolar models of the nova eruption, assuming the free-free process, and show the effects of varying different parameters on the radio light curves. The parameters considered include the ratio of the minor- to major-axis, the inclination angle, and shell thickness. We also show the uncertainty introduced when fitting spherical-model synthetic light curves to bipolar-model synthetic light curves. We find that the optically thick phase rises with the same power law (S {sub ν}∝t {sup 2}) for both the spherical and bipolar models. In the bipolar case, there is a 'plateau' phase—depending on the thickness of the shell as well as the ratio of the minor- to major-axis—before the final decline, which follows the same power law (S {sub ν}∝t {sup –3}) as in the spherical case. Finally, fitting spherical models to the bipolar-model synthetic light curves requires, in the worst-case scenario, doubling the ejected mass, more than halving the electron temperature, and reducing the shell thickness by nearly a factor of 10. This implies that in some systems we have been over-predicting the ejected masses and under-predicting the electron temperature of the ejecta.

  14. Radio Frequency Models of Novae in Eruption. I. The Free-Free Process in Bipolar Morphologies

    Science.gov (United States)

    Ribeiro, V. A. R. M.; Chomiuk, L.; Munari, U.; Steffen, W.; Koning, N.; O'Brien, T. J.; Simon, T.; Woudt, P. A.; Bode, M. F.

    2014-09-01

    Observations of novae at radio frequencies provide us with a measure of the total ejected mass, density profile, and kinetic energy of a nova eruption. The radio emission is typically well characterized by the free-free emission process. Most models to date have assumed spherical symmetry for the eruption, although for as long as there have been radio observations of these systems, it has been known that spherical eruptions are too simplistic a geometry. In this paper, we build bipolar models of the nova eruption, assuming the free-free process, and show the effects of varying different parameters on the radio light curves. The parameters considered include the ratio of the minor- to major-axis, the inclination angle, and shell thickness. We also show the uncertainty introduced when fitting spherical-model synthetic light curves to bipolar-model synthetic light curves. We find that the optically thick phase rises with the same power law (S νvpropt 2) for both the spherical and bipolar models. In the bipolar case, there is a "plateau" phase—depending on the thickness of the shell as well as the ratio of the minor- to major-axis—before the final decline, which follows the same power law (S νvpropt -3) as in the spherical case. Finally, fitting spherical models to the bipolar-model synthetic light curves requires, in the worst-case scenario, doubling the ejected mass, more than halving the electron temperature, and reducing the shell thickness by nearly a factor of 10. This implies that in some systems we have been over-predicting the ejected masses and under-predicting the electron temperature of the ejecta.

  15. Guidelines for predicting lesion size at common endocardial locations during radio-frequency ablation.

    Science.gov (United States)

    Tungjitkusolmun, S; Vorperian, V R; Bhavaraju, N; Cao, H; Tsai, J Z; Webster, J G

    2001-02-01

    We used the finite element method to study the effect of radio-frequency (RF) catheter ablation on tissue heating and lesion formation at different intracardiac sites exposed to different regional blood velocities. We examined the effect of application of RF current in temperature- and power-controlled mode above and beneath the mitral valve annulus where the regional blood velocities are high and low respectively. We found that for temperature-controlled ablation, more power was delivered to maintain the preset tip temperature at sites of high local blood velocity than at sites of low local blood velocity. This induced more tissue heating and larger lesion volumes than ablations at low velocity regions. In contrast, for power-controlled ablation, tissue heating was less at sites of high compared with low local blood velocity for the same RF power setting. This resulted in smaller lesion volumes at sites of low local velocity. Our numerical analyzes showed that during temperature-controlled ablation at 60 degrees C, the lesion volumes at sites above and underneath the mitral valve were comparable when the duration of RF current application was 10 s. When the duration of RF application was extended to 60 s and 120 s, lesion volumes were 33.3% and 49.4% larger above the mitral valve than underneath the mitral valve. Also, with temperature-controlled ablation, tip temperature settings of 70 degrees C or greater were associated with a risk of tissue overheating during long ablations at high local blood velocity sites. In power-controlled ablation (20 W), the lesion volume formed underneath the mitral valve was 165.7% larger than the lesion volume above the mitral valve after 10 s of ablation. We summarized the guidelines for energy application at low and high flow regions.

  16. Design of catheter radio frequency coils using coaxial transmission line resonators for interventional neurovascular MR imaging.

    Science.gov (United States)

    Zhang, Xiaoliang; Martin, Alastair; Jordan, Caroline; Lillaney, Prasheel; Losey, Aaron; Pang, Yong; Hu, Jeffrey; Wilson, Mark; Cooke, Daniel; Hetts, Steven W

    2017-04-01

    It is technically challenging to design compact yet sensitive miniature catheter radio frequency (RF) coils for endovascular interventional MR imaging. In this work, a new design method for catheter RF coils is proposed based on the coaxial transmission line resonator (TLR) technique. Due to its distributed circuit, the TLR catheter coil does not need any lumped capacitors to support its resonance, which simplifies the practical design and construction and provides a straightforward technique for designing miniature catheter-mounted imaging coils that are appropriate for interventional neurovascular procedures. The outer conductor of the TLR serves as an RF shield, which prevents electromagnetic energy loss, and improves coil Q factors. It also minimizes interaction with surrounding tissues and signal losses along the catheter coil. To investigate the technique, a prototype catheter coil was built using the proposed coaxial TLR technique and evaluated with standard RF testing and measurement methods and MR imaging experiments. Numerical simulation was carried out to assess the RF electromagnetic field behavior of the proposed TLR catheter coil and the conventional lumped-element catheter coil. The proposed TLR catheter coil was successfully tuned to 64 MHz for proton imaging at 1.5 T. B1 fields were numerically calculated, showing improved magnetic field intensity of the TLR catheter coil over the conventional lumped-element catheter coil. MR images were acquired from a dedicated vascular phantom using the TLR catheter coil and also the system body coil. The TLR catheter coil is able to provide a significant signal-to-noise ratio (SNR) increase (a factor of 200 to 300) over its imaging volume relative to the body coil. Catheter imaging RF coil design using the proposed coaxial TLR technique is feasible and advantageous in endovascular interventional MR imaging applications.

  17. Particle modelling of magnetically confined oxygen plasma in low pressure radio frequency discharge

    Energy Technology Data Exchange (ETDEWEB)

    Benyoucef, Djilali [Laboratoire Génie Electrique et Energie Renouvelables, Chlef University (Algeria); Yousfi, Mohammed [Université de de Toulouse, LAPLACE, UMR CNRS 5213, 118 Route de Narbonne, Toulouse 31062 (France)

    2015-01-15

    The main objective of this paper is the modelling and simulation of a radio frequency (RF) discharge in oxygen at low pressure and at room temperature, including the effect of crossed electric and magnetic fields for generation and confinement of oxygen plasma. The particle model takes into account one axial dimension along the electric field axis and three velocity components during the Monte Carlo treatment of the collisions between charged particles and background gas. The simulation by this developed code allows us not only to determine the electrodynamics characteristics of the RF discharge, but also to obtain kinetics and energetic description of reactive oxygen plasma at low pressure. These information are very important for the control of the deep reactive-ion etching technology of the silicon to manufacture capacitors with high density and for the deposition thick insulating films or thick metal to manufacture micro-coils. The simulation conditions are as follows: RF peak voltage of 200 V, frequency of 13.56 MHz, crossed magnetic field varying from 0 to 50 Gauss, and oxygen pressure of 13.8 Pa. In the presence of magnetic field, the results show an increase of the plasma density, a decrease of the electron mean energy, and also a reduction of the ratio between electron density and positive ion density. Finally in order to validate, the results are successfully compared with measurements already carried out in the literature. The conditions of comparison are from 100 to 300 V of the peak voltage at 13.56 MHz under a pressure of 13.8 Pa and a gap distance of 2.5 cm.

  18. Three-dimensional self-consistent simulations of multipacting in superconducting radio frequency cavities

    Energy Technology Data Exchange (ETDEWEB)

    Chet Nieter

    2010-12-01

    Superconducting radio frequency (SRF) cavities are a popular choice among researchers designing new accelerators because of the reduced power losses due to surface resistance. However, SRF cavities still have unresolved problems, including the loss of power to stray electrons. Sources of these electrons are field emission from the walls and ionization of background gas, but the predominant source is secondary emission yield (SEY) from electron impact. When the electron motion is in resonance with the cavity fields the electrons strike the cavity surface repeatedly creating a resonant build up of electrons referred to as multipacting. Cavity shaping has successfully reduced multipacting for cavities used in very high energy accelerators. However, multipacting is still a concern for the cavity power couplers, where shaping is not possible, and for cavities used to accelerate particles at moderate velocities. This Phase II project built upon existing models in the VORPAL simulation framework to allow for simulations of multipacting behavior in SRF cavities and their associated structures. The technical work involved allowed existing models of secondary electron generation to work with the complex boundary conditions needed to model the cavity structures. The types of data produced by VORPAL were also expanded to include data common used by cavity designers to evaluate cavity performance. Post-processing tools were also modified to provide information directly related to the conditions that produce multipacting. These new methods were demonstrated by running simulations of a cavity design being developed by researchers at Jefferson National Laboratory to attempt to identify the multipacting that would be an issue for the cavity design being considered. These simulations demonstrate that VORPAL now has the capabilities to assist researchers working with SRF cavities to understand and identify possible multipacting issues with their cavity designs.

  19. Thermoelectric properties of cobalt–antimonide thin films prepared by radio frequency co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Aziz; Han, Seungwoo, E-mail: swhan@kimm.re.kr

    2015-07-31

    Co–Sb thin films with an Sb content in the range 65–76 at.%, were deposited on a thermally oxidized Si (100) substrate preheated at 200 °C using radio-frequency co-sputtering. Evaluation using scanning electron microscopy images and X-ray diffraction reveals that the films were polycrystalline, with a grain size in the range 100–250 nm. Energy-dispersive spectroscopy analysis indicates single-phase CoSb{sub 2} and CoSb{sub 3} films, as well as multiphase thin films with either CoSb{sub 2} or CoSb{sub 3} as the dominant phase. The electrical and thermoelectric properties were measured and found to be strongly dependent on the observed phases and the defect concentrations. The CoSb{sub 2} thin films were found to exhibit a significant n-type thermoelectric effect, which, coupled with the very low electrical resistivity, resulted in a larger power factor than that of the CoSb{sub 3} thin films. We find power factors of 0.73 mWm{sup −1} K{sup −2} and 0.67 mWm{sup −1} K{sup −2} for the CoSb{sub 2} and CoSb{sub 3} thin films, respectively. - Highlights: • Polycrystalline Co–Sb thin films were obtained by present deposition strategy. • CoSb{sub 2} and CoSb{sub 3} have semimetal and semiconductor characteristics respectively. • The Seebeck coefficient depends heavily on defect concentration and impurity phases. • Film properties in the second heating cycle were different from the first. • CoSb{sub 2} is found to possess significant n-type thermopower.

  20. Radio-Frequency Pulse Compression for Linear Accelerators.

    Science.gov (United States)

    Nantista, Christopher Dennis

    Recent efforts to develop plans for an electron -positron linear collider with center-of-mass energy approaching a TeV have highlighted the need for sources capable of delivering hundreds of megawatts of peak rf drive power at X-band frequencies. This need has driven work in the area of rf pulse compression, which enhances the peak power available from pulsed rf tubes by compressing their output pulses in time, accumulating the available energy into shorter pulses. The classic means of rf pulse compression for linear accelerators is SLED. This technique is described, and the problem it presents for multibunch acceleration explained. Other pulse compression schemes, capable of producing suitable output pulses are explored, both theoretically and experimentally, in particular Binary Pulse Compression and SLED-II. The merits of each are considered with regard to gain, efficiency, complexity, size and cost. The development of some novel system components, along with the theory behind their design, is also discussed. The need to minimize copper losses in long waveguide runs led to the use of the circular TE_{01} propagation mode in over-moded guide, requiring much attention to mechanisms of coupling power between modes. The construction and commissioning of complete, high-power pulse compression systems is reported on, as well as their use in the testing of X-band accelerating structures, which, along with the X-band klystrons used, were developed at SLAC in parallel with the pulse compression work. The focus of the dissertation is on SLED-II, the favored scheme in some current linear accelerator designs. In addition to our experimental results, practical implementation considerations and design improvements are presented. The work to date has led to detailed plans for SLED-II systems to be used in the Next Linear Collider Test Accelerator, now under construction at SLAC. The prototype of the upgraded system is near completion. Descriptions of various rf pulse

  1. A measurement method of time jitter of a laser pulse with respect to the radio-frequency wave phase in a photocathode radio-frequency gun

    CERN Document Server

    Liu Sheng Guang; Wang Ming Kai

    2002-01-01

    In a photo-cathode radio-frequency (rf) gun, the micro-bunched charge output from the gun is dependent linearly on the laser injection phase, due to the Scottay effect in the process of photoemission and the procedure of the electron longitudinal acceleration. Based on this principle, a new method is proposed, which should be utilized to measure the time jitter between the driving laser pulse and the rf phase with a very high resolution of a few tens of femto-seconds

  2. Flexible diodes for radio frequency (RF) electronics: a materials perspective

    KAUST Repository

    Semple, James

    2017-10-30

    Over the last decade, there has been increasing interest in transferring the research advances in radiofrequency (RF) rectifiers, the quintessential element of the chip in the RF identification (RFID) tags, obtained on rigid substrates onto plastic (flexible) substrates. The growing demand for flexible RFID tags, wireless communications applications and wireless energy harvesting systems that can be produced at a low-cost is a key driver for this technology push. In this topical review, we summarise recent progress and status of flexible RF diodes and rectifying circuits, with specific focus on materials and device processing aspects. To this end, different families of materials (e.g. flexible silicon, metal oxides, organic and carbon nanomaterials), manufacturing processes (e.g. vacuum and solution processing) and device architectures (diodes and transistors) are compared. Although emphasis is placed on performance, functionality, mechanical flexibility and operating stability, the various bottlenecks associated with each technology are also addressed. Finally, we present our outlook on the commercialisation potential and on the positioning of each material class in the RF electronics landscape based on the findings summarised herein. It is beyond doubt that the field of flexible high and ultra-high frequency rectifiers and electronics as a whole will continue to be an active area of research over the coming years.

  3. ALINE: A device dedicated to understanding radio-frequency sheaths

    Directory of Open Access Journals (Sweden)

    S. Devaux

    2017-08-01

    Full Text Available In fusion devices, radiofrequency (RF antennas are used for heating the plasma. Those antennas and the plasma interact with each other through the so-called RF sheaths, layers of plasma where the quasi-neutrality breaks down and large electric fields arise. Among the effects of RF sheaths, there is the enhancement of the particles and energy fluxes toward the surface of the antenna, which in turn generate hot spots and release impurities, which are both deleterious for plasma operations. RF sheaths comprehension stumbles on the difficulty to achieve in situ measurements of the sheath properties, as scrape-off layer plasmas are a harsh environment. The very goal of the ALINE device is to tackle this issue and to fulfil the blank between numerical simulations and full-scale experiment by providing measurements within the RF sheaths in a controlled environment. In this paper we report on the latest experimental results from ALINE, in which a cylindrical Langmuir probe mounted on a remotely controlled and programmable arm allows for plasma characterizations in the three dimensions of space around the stainless steel antenna, including the sheath. We present a series of density and potential profiles and three dimension (3D maps in the plasma surrounding a stainless-steel RF antenna as well as in the sheath itself, for unmagnetized and magnetized plasmas.

  4. Flexible diodes for radio frequency (RF) electronics: a materials perspective

    Science.gov (United States)

    Semple, James; Georgiadou, Dimitra G.; Wyatt-Moon, Gwenhivir; Gelinck, Gerwin; Anthopoulos, Thomas D.

    2017-12-01

    Over the last decade, there has been increasing interest in transferring the research advances in radiofrequency (RF) rectifiers, the quintessential element of the chip in the RF identification (RFID) tags, obtained on rigid substrates onto plastic (flexible) substrates. The growing demand for flexible RFID tags, wireless communications applications and wireless energy harvesting systems that can be produced at a low-cost is a key driver for this technology push. In this topical review, we summarise recent progress and status of flexible RF diodes and rectifying circuits, with specific focus on materials and device processing aspects. To this end, different families of materials (e.g. flexible silicon, metal oxides, organic and carbon nanomaterials), manufacturing processes (e.g. vacuum and solution processing) and device architectures (diodes and transistors) are compared. Although emphasis is placed on performance, functionality, mechanical flexibility and operating stability, the various bottlenecks associated with each technology are also addressed. Finally, we present our outlook on the commercialisation potential and on the positioning of each material class in the RF electronics landscape based on the findings summarised herein. It is beyond doubt that the field of flexible high and ultra-high frequency rectifiers and electronics as a whole will continue to be an active area of research over the coming years.

  5. Thermocatalytic treatment of biomass tar model compounds via radio frequency.

    Science.gov (United States)

    Anis, Samsudin; Zainal, Z A; Bakar, M Z A

    2013-05-01

    A new effective RF tar thermocatalytic treatment process with low energy intensive has been proposed to remove tar from biomass gasification. Toluene and naphthalene as biomass tar model compounds were removed via both thermal and catalytic treatment over a wide temperature range from 850 °C to 1200 °C and 450 °C to 900 °C, respectively at residence time of 0-0.7 s. Thermal characteristics of the new technique are also described in this paper. This study clearly clarified that toluene was much easier to be removed than naphthalene. Soot was found as the final product of thermal treatment of the tar model and completely removed during catalytic treatment. Radical reactions generated by RF non-thermal effect improve the tar removal. The study showed that Y-zeolite has better catalytic activity compared to dolomite on toluene and naphthalene removal due to its acidic nature and large surface area, even at lower reaction temperature of about 550 °C. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Hydrogen production in a radio-frequency plasma source operating on water vapor

    Science.gov (United States)

    Nguyen, Son-Ca Viet Thi

    The global energy and climate challenges have motivated development of innovative techniques to satisfy energy demand while minimizing emissions. To this end, hydrogen as an alternative energy carrier in the transportation sector is an attractive option. In addition, there is already a great need for hydrogen gas in several industrial processes such as hydro-cracking of crude oil to produce gasoline and production of ammonia and methanol. The current dominant methods of hydrogen production from fossil fuels are well-developed and have reached relatively high energy efficiencies (up to 85%), but these methods rely on non-renewable natural resources and produce carbon dioxide emissions. This work investigates the feasibility of hydrogen production by dissociating water molecules in a radio-frequency (RF) plasma discharge. In addition to the widespread usage of hydrogen gas, applications of water plasma have permeated in many areas of research, and information on basic behaviors of a water plasma discharge will provide fruitful insights for other researchers. An RF plasma source equipped with a double-helix antenna (m = 1 mode) and an applied axial magnetic field is designed to operate on water vapor. It is shown that water molecules are being dissociated in the discharge. Experimental results show that the rate of hydrogen production increases linearly with RF power in the absence of the applied axial magnetic field. With the magnetic field, the rate of hydrogen production increases from 250 to 500 W, and begins to saturate with RF power. Despite this saturation, it is shown that hydrogen increases with magnetic field strength at a fixed RF power. Further, the rate of hydrogen production increases with water input flow rate up to 100 sccm for a fixed RF power level, and begins to decrease at 125 sccm. This dissertation characterizes the rate of hydrogen production and plasma properties as a function of RF power, applied B-field strength, and water input flow rate. A

  7. Magnetic characterization of radio frequency heat affected micron size Fe3O4 powders: a bio-application perspective

    CSIR Research Space (South Africa)

    Roul, BK

    2009-05-01

    Full Text Available Micron size Fe3O4 powders were chemically prepared and processed by radio frequency (13.56 MHz) oxygen plasma irradiation technique at different elevated temperatures using low radio frequency (RF) power level. Low magnetic field RF superconducting...

  8. Three-dimensional multi-physics analysis and commissioning frequency tuning strategy of a radio-frequency quadrupole accelerator

    Science.gov (United States)

    Ma, Wei; Lu, Liang; Liu, Ting; Xu, Xianbo; Sun, Liepeng; Li, Chenxing; Shi, Longbo; Wang, Wenbin; He, Yuan; Zhao, Hongwei

    2017-09-01

    The resonant frequency stability of the radio frequency quadrupole (RFQ) is an important concern during commissioning. The power dissipated on the RFQ internal surface will heat the cavity and lead to a temperature rise and a structural deformation, especially in the continuous wave (CW) RFQs, which will cause the resonant frequency shifts. It is important to simulate the temperature rise, the deformation and the frequency shift of the RFQ cavity. The cooling water takes away the power to maintain the frequency stability. Meanwhile, the RFQ resonant frequency can be tuned by adjusting the water temperature. In this paper, a detailed three-dimensional multi-physics analysis of the Low Energy Accelerator Facility (LEAF) RFQ will be presented and a commissioning frequency tuning strategy will be studied.

  9. Design and characterization of a radio-frequency-powered glow discharge source for double-focusing mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.C.; Donohue, D.L.; Smith, D.H.; Lewis, T.A. (Oak Ridge National Lab., TN (United States)); Marcus, R. K. (Clemson Univ., SC (United States))

    1993-09-15

    A radio-frequency- (rf-) powered glow discharge has been interfaced to a double-focusing mass spectrometer. This type of discharge allows direct analysis of nonconducting, as well as conducting, solids. The rf discharge source and electrical system overcome several problems which have inhibited success in prior efforts. Problems of inadequate rf shielding, maintaining the necessary dc bias potential on the sample surface, preventing rf modulation of ion energies, and coupling of the accelerating potential to the discharge are resolved. Representative spectra of glass, soil, and brass matrices are presented. Preliminary relative sensitivity factors for conducting and non-conducting matrices show relatively small differences in ion yields across the periodic table. 31 refs., 9 figs., 2 tabs.

  10. Hybrid Radio Frequency/Free-Space Optics (RF/FSO) Wireless Sensor Network: Security Concerns and Protective Measures

    Science.gov (United States)

    Banerjee, Koushik; Sharma, Hemant; Sengupta, Anasuya

    Wireless sensor networks (WSNs) are ad hoc wireless networks that are written off as spread out structure and ad hoc deployment. Sensor networks have all the rudimentary features of ad hoc networks but to altered points—for instance, considerably lesser movement and far more energy necessities. Commonly used technology for communication is radio frequency (RF) communications. Free-space optics (FSO) is relatively new technology which has the prospective to deliver remarkable increases in network lifetime of WSN. Hybrid RF/FSO communications has been suggested to decrease power consumption by a single sensor node. It is observed that security plays a very important role for either RF WSN or hybrid RF/FSO WSN as those are vulnerable to numerous threats. In this paper, various possible attacks in RF/FSO WSN are discussed and aimed to propose some way out from those attacks.

  11. Radio-frequency MBE growth of cubic GaN on BP(001)/Si(001) hetero-structure

    Science.gov (United States)

    Kikuchi, T.; Somintac, A. S.; Odawara, M.; Udagawa, T.; Ohachi, T.

    2006-06-01

    Zincblende gallium nitride (c-GaN) was grown on zincblende boron monophosphide (BP)/silicon (001) using radio-frequency plasma-assisted molecular-beam epitaxy (RF-MBE). In spite of near perfect lattice-match coordination between c-GaN and BP, the initial nucleation of c-GaN was 3D island formation due to imperfect wetting. Using cross-sectional electron backscatter diffraction pattern (x-EBSD), it was found that dislocations were eliminated with an increase of epilayer thickness of c-GaN, and finally 99.4% c-GaN (001) was achieved. The (2x2) and (4x1) reconstructions of the surface of almost pure c-GaN (001) were confirmed by reflection high-energy electron diffraction (RHEED) under arsenic-contamination-free conditions.

  12. Plasma acceleration using a radio frequency self-bias effect

    Energy Technology Data Exchange (ETDEWEB)

    Rafalskyi, D.; Aanesland, A. [Laboratoire de Physique des Plasmas (CNRS, Ecole Polytechnique, Sorbonne Universités, UPMC Univ Paris 06, Univ Paris-Sud), Ecole Polytechnique, 91128 Palaiseau (France)

    2015-06-15

    In this work plasma acceleration using a RF self-bias effect is experimentally studied. The experiments are conducted using a novel plasma accelerator system, called Neptune, consisting of an inductively coupled plasma source and a RF-biased set of grids. The plasma accelerator can operate in a steady state mode, producing a plasma flow with separately controlled plasma flux and velocity without any magnetic configuration. The operating pressure at the source output is as low as 0.2 mTorr and can further be decreased. The ion and electron flows are investigated by measuring the ion and electron energy distribution functions both space resolved and with different orientations with respect to the flow direction. It is found that the flow of electrons from the source is highly anisotropic and directed along the ion flow and this global flow of accelerated plasma is well localized in the plasma transport chamber. The maximum flux is about 7.5·10{sup 15} ions s{sup −1} m{sup −2} (at standard conditions) on the axis and decreasing to almost zero at a radial distances of more than 15 cm from the flow axis. Varying the RF acceleration voltage in the range 20–350 V, the plasma flow velocity can be changed between 10 and 35 km/s. The system is prospective for different technology such as space propulsion and surface modification and also interesting for fundamental studies for space-related plasma simulations and investigation of the dynamo effect using accelerated rotating plasmas.

  13. Methods and applications of radio frequency geophysics in glaciology

    Science.gov (United States)

    Holschuh, Nicholas

    Simple radar systems of the past were used primarily for radar depth sounding, the process of using reflection travel times and electromagnetic velocities to determine the ice thickness. Modern radioglaciology uses both the travel times and reflection amplitudes to make inferences about the englacial and subglacial environments; however, non-uniqueness in geophysical data, combined with the large number of physical parameters that control reflection amplitude, have led to significant uncertainties in this type of analysis. In this set of studies, I improve on data collection, processing, and assimilation methods, with a focus on radar reflection amplitudes and internal layers. The first two studies are devoted to radar survey methods, in which I examine the impact of reflector geometry on amplitude (2), and investigate an independent measure of radar attenuation using variable-offset data, in an effort to eliminate the effects of ice chemistry and temperature on reflection amplitudes (3). These studies emphasize the fact that radar data are a product of both the physical system and the imaging process, and caution glaciologists from over-interpreting processing artifacts common in radar data collected in areas of complex glacial flow. In the following two chapters, I go on to provide glaciological applications of processed radar data, interpreting the record of complex flow left behind in englacial reflector slopes (4), and applying improved boundary conditions to better predict the maximum extent of West Antarctic collapse (5). These studies use geometric information from the bed reflector and englacial reflectors to describe the flow regime present in Antarctica today. Chapter 4 examines how boundary conditions that are difficult to observe directly (the geothermal heat flux, as well as the frictional and deformation characteristics of the ice-sheet substrate) manifest through internal layer deformation. Chapter 5 focuses on Marie Byrd Land (MBL), where

  14. Full three-dimensional approach to the design and simulation of a radio-frequency quadrupole

    Directory of Open Access Journals (Sweden)

    B. Mustapha

    2013-12-01

    Full Text Available We have developed a new full 3D approach for the electromagnetic and beam dynamics design and simulation of a radio-frequency quadrupole (RFQ. A detailed full 3D model including vane modulation was simulated, which was made possible by the ever advancing computing capabilities. The electromagnetic (EM design approach was first validated using experimental measurements on an existing prototype RFQ and more recently on the actual full size RFQ. Two design options have been studied, the original with standard sinusoidal modulation over the full length of the RFQ; in the second design, a trapezoidal modulation was used in the accelerating section of the RFQ to achieve a higher energy gain for the same power and length. A detailed comparison of both options is presented supporting our decision to select the trapezoidal design. The trapezoidal modulation increased the shunt impedance of the RFQ by 34%, the output energy by 15% with a similar increase in the peak surface electric field, but practically no change in the dynamics of the accelerated beam. The beam dynamics simulations were performed using three different field methods. The first uses the standard eight-term potential to derive the fields, the second uses 3D fields from individual cell-by-cell models, and the third uses the 3D fields for the whole RFQ as a single cavity. A detailed comparison of the results from TRACK shows a very good agreement, validating the 3D fields approach used for the beam dynamics studies. The EM simulations were mainly performed using the CST Microwave-Studio with the final results verified using other software. Detailed segment-by-segment and full RFQ frequency calculations were performed and compared to the measured data. The maximum frequency deviation is about 100 kHz. The frequencies of higher-order modes have also been calculated and finally the modulation and tuners effects on both the frequency and field flatness have been studied. We believe that with

  15. Manipulation of ultracold atoms in dressed adiabatic radio-frequency potentials

    DEFF Research Database (Denmark)

    Lesanovsky, Igor; Hofferberth, S.; Schmiedmayer, Jörg

    2006-01-01

    We explore properties of atoms whose magnetic hyperfine sublevels are coupled by an external magnetic radio frequency (rf) field. We perform a thorough theoretical analysis of this driven system and present a number of systematic approximations which eventually give rise to dressed adiabatic radio...... frequency potentials. The predictions of this analytical investigation are compared to numerically exact results obtained by a wave packet propagation. We outline the versatility and flexibility of this class of potentials and demonstrate their potential use to build atom optical elements such as double...... wells, interferometers, and ringtraps. Moreover, we perform simulations of interference experiments carried out in rf induced double-well potentials. We discuss how the nature of the atom-field coupling mechanism gives rise to a decrease of the interference contrast....

  16. 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.

  17. Lightning detection from Space Science and Applications Team review. [optical and radio frequency sensors

    Science.gov (United States)

    Few, A. A., Jr.

    1981-01-01

    The various needs for lightning data that exist among potential users of satellite lightning data were identified and systems were defined which utilize the optical and radio frequency radiations from lightning to serve as the satellite based lightning mapper. Three teams worked interactively with NASA to develop a system concept. An assessment of the results may be summarized as follows: (1) a small sensor system can be easily designed to operate on a geostationary satellite that can provide the bulk of the real time user requirements; (2) radio frequency systems in space may be feasible but would be much larger and more costly; RF technology for this problem lags the optical technology by years; and (3) a hybrid approach (optical in space and RF on the ground) would provide the most complete information but is probably unreasonably complex and costly at this time.

  18. Mapping of the radio frequency magnetic field with a MR snapshot FLASH technique.

    Science.gov (United States)

    Klose, U

    1992-01-01

    A fast method to measure the radio frequency magnetic field intensity distribution during magnetic resonance examinations within objects or patients is proposed. Using a snapshot FLASH sequence, several images are obtained with different transmitter amplitudes for the single prepulse prior to the imaging sequence. The signal intensity at each pixel within a selected slice is diminished by this prepulse, unless the pulse angle is 0 degrees or a multiple of 360 degrees. This condition can be used to measure that transmitter amplitude Umax for each pixel which causes an excitation of 360 degrees by the prepulse. The values of Umax can be visualized in an image and are inversely proportional to the radio frequency magnetic field strength at each position within the image. The method can also be used for in-vivo measurements, where it may be difficult to realize prepulses with sufficient high flip angles. In these cases, signal corresponding to a 180 degree prepulse can be used for calculating Umax.

  19. Etching mechanism of niobium in coaxial Ar/Cl2 radio frequency plasma

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Janardan [Old Dominion Univ., Norfolk, VA (United States); Im, Do [Old Dominion Univ., Norfolk, VA (United States); Popovic, Svetozar [Old Dominion Univ., Norfolk, VA (United States); Valente-Feliciano, Anne -Marie [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Phillips, H. Larry [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Vuskovic, Leposova [Old Dominion Univ., Norfolk, VA (United States)

    2015-03-18

    The understanding of the Ar/Cl2 plasma etching mechanism is crucial for the desired modification of inner surface of the three dimensional niobium (Nb) superconductive radio frequency cavities. Uniform mass removal in cylindrical shaped structures is a challenging task because the etch rate varies along the direction of gas flow. The study is performed in the asymmetric coaxial radio-frequency (rf) discharge with two identical Nb rings acting as a part of the outer electrode. The dependence of etch rate uniformity on pressure, rf power, dc bias, Cl2 concentration, diameter of the inner electrode, temperature of the outer cylinder, and position of the samples in the structure is determined. Furthermore, to understand the plasma etching mechanisms, we have studied several factors that have important influence on the etch rate and uniformity, which include the plasma sheath potential, Nb surface temperature, and the gas flow rate.

  20. Resonant-frequency discharge in a multi-cell radio frequency cavity

    Science.gov (United States)

    Popović, S.; Upadhyay, J.; Mammosser, J.; Nikolić, M.; Vušković, L.

    2014-11-01

    We are reporting experimental results on a microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency cryo-module. This discharge offers a mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the issues related to resonant detuning due to sustained multi-cell cavity plasma. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal.

  1. Nonflat time-variable dark energy cosmology

    Science.gov (United States)

    Pavlov, Anatoly; Westmoreland, Shawn; Saaidi, Khaled; Ratra, Bharat

    2013-12-01

    We generalize the time-variable dark energy scalar field Φ model (ΦCDM) to nonflat space. We show that even in the space-curvature-dominated epoch the scalar field solution is a time-dependent fixed point or attractor, with scalar field energy density that grows relative to the energy density in spatial curvature. This is the first example of a physically consistent and complete model of dynamical dark energy in a nonflat geometry.

  2. A Cost Benefit Analysis of Radio Frequency Identification (RFID) Implementation at the Defense Microelectronics Activity (DMEA)

    Science.gov (United States)

    2011-12-01

    are generally used in passive tag applications with high- water content, such as fruit. 7 Table 1. RFID Tag Attributes Active RFID Passive RFID ...Antennas As with all RFID technologies, antennas come in a large range of sizes, from under a square centimeter to larger than a square meter (Asif...ANALYSIS OF RADIO FREQUENCY IDENTIFICATION ( RFID ) IMPLEMENTATION AT THE DEFENSE MICROELECTRONICS ACTIVITY (DMEA) by James B. Gerber December

  3. Probing the continuous radio frequency spectrum of water relaxation using a carbon nanotube.

    Science.gov (United States)

    Kim, H T; Kim, D W; Hwang, J S; Shin, J S; Whang, D; Ahn, D; Hwang, S W

    2011-02-23

    We have obtained the continuous radio frequency spectrum of water molecule relaxation using carbon nanotubes (CNT) as a high-speed nanoprobe. Three sets of characteristic time scales are clearly identified. Two sets are attributed to the electric-field-driven polarization of water molecules bound to CNTs and the collective relaxation of water layers in the vicinity of CNTs, respectively. The third set is appreciable only in air, and can be related to triplet oxygen relaxation. © 2011 IOP Publishing Ltd

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

    OpenAIRE

    John Jairo Ramírez Echeverry

    2012-01-01

    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 soluti...

  5. Growth Enhancement of Radish Sprouts Induced by Low Pressure O2 Radio Frequency Discharge Plasma Irradiation

    Science.gov (United States)

    Kitazaki, Satoshi; Koga, Kazunori; Shiratani, Masaharu; Hayashi, Nobuya

    2012-01-01

    We studied growth enhancement of radish sprouts (Raphanus sativus L.) induced by low pressure O2 radio frequency (RF) discharge plasma irradiation. The average length of radish sprouts cultivated for 7 days after O2 plasma irradiation is 30-60% greater than that without irradiation. O2 plasma irradiation does not affect seed germination. The experimental results reveal that oxygen related radicals strongly enhance growth, whereas ions and photons do not.

  6. Radio-frequency properties of stacked long Josephson junctions with nonuniform bias current distribution

    DEFF Research Database (Denmark)

    Filatrella, G; Pedersen, Niels Falsig

    1999-01-01

    We have numerically investigated the behavior of stacks of long Josephson junctions considering a nonuniform bias profile. In the presence of a microwave field the nonuniform bias, which favors the formation of fluxons, can give rise to a change of the sequence of radio-frequency induced steps....... The amplitude of the steps is enhanced when the external frequency matches the fluxon shuttling regime. ©1999 American Institute of Physics....

  7. Repetitive control for high-performance resonant pulsed power supply in radio frequency applications

    OpenAIRE

    Ji, Chao; Zanchetta, Pericle; Carastro, Fabio; Clare, Jon C.

    2013-01-01

    This paper presents a novel three phase series resonant parallel loaded (SRPL) resonant converter topology for radio frequency (RF) applications. The proposed converter is capable to produce as output voltage a series of “long pulses”, each one lasting 1ms in time. Three individual single phase resonant stages are able to operate independently in conjunction with three separate single phase output rectification stages. Due to this important feature, the converter has a strong ability of rejec...

  8. CMOS radio frequency circuits for short-range direct-conversion receivers

    OpenAIRE

    Kaukovuori, Jouni

    2008-01-01

    The research described in this thesis is focused on the design and implementation of radio frequency (RF) circuits for direct-conversion receivers. The main interest is in RF front-end circuits, which contain low-noise amplifiers, downconversion mixers, and quadrature local oscillator signal generation circuits. Three RF front-end circuits were fabricated in a short-channel CMOS process and experimental results are presented. A low-noise amplifier (LNA) is typically the first amplifying b...

  9. Noise performance of the radio-frequency single-electron transistor

    OpenAIRE

    Roschier, Leif; Hakonen, Pertti J.; Bladh, K.; Delsing, P.; Lehnert, K. W.; Spietz, Lafe; Schoelkopf, Rob

    2004-01-01

    We have analyzed a radio-frequency single-electron-transistor (RF-SET) circuit that includes a high-electron-mobility-transistor (HEMT)amplifier, coupled to the single-electron-transistor (SET) via an impedance transformer. We consider how power is transferred between different components of the circuit, model noise components, and analyze the operating conditions of practical importance. The results are compared with experimental data on SETs. Good agreement is obtained between our noise mod...

  10. Adiabatic radio-frequency potentials for the coherent manipulation of matter waves

    DEFF Research Database (Denmark)

    Lesanovsky, Igor; Schumm, Thorsten; Hofferberth, S.

    2006-01-01

    Adiabatic dressed state potentials are created when magnetic substates of trapped atoms are coupled by a radio-frequency field. We discuss their theoretical foundations and point out fundamental advantages over potentials purely based on static fields. The enhanced flexibility enables one...... to implement numerous configurations, including double wells, Mach-Zehnder, and Sagnac interferometers which even allows for internal state-dependent atom manipulation. These can be realized using simple and highly integrated wire geometries on atom chips....

  11. Low-Power Radio-Frequency SiGe Analog-to-Digital Converter

    Science.gov (United States)

    Thompson, Willie L, II; Hall, Wesley G.; Piepmeier, Jeffrey R.; Johnson-Bey, Charles T.

    2003-01-01

    A low-power, radio-frequency analog-to-digital converter (RF-ADC) for soil moisture remote sensing was designed and fabricated. The RF-ADC is the fundamental component used in a direct-sampling digital radiometer, which is proposed to minimize the power dissipation and system complexity for synthetic thinned array radiometer. The circuit was implemented using 0.8 micron 35-GHz silicon germanium BiCMOS technology. The total power dissipation was 222 mW.

  12. Application safety evaluation of the radio frequency identification tag under magnetic resonance imaging

    OpenAIRE

    Fei, Xiaolu; Li,Shanshan; Gao, Shan; Wei, Lan; Wang, Lihong

    2014-01-01

    Background Radio Frequency Identification(RFID) has been widely used in healthcare facilities, but it has been paid little attention whether RFID applications are safe enough under healthcare environment. The purpose of this study is to assess the effects of RFID tags on Magnetic Resonance (MR) imaging in a typical electromagnetic environment in hospitals, and to evaluate the safety of their applications. Methods A Magphan phantom was used to simulate the imaging objects, while active RFID ta...

  13. ASACUSA's radio-frequency quadrupole decelerator, open to show the four-rod structure along the centre, which crosses 35 resonator chambers formed by the vertical partitions.

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    The Radio-Frequency Quadrupole, RFQD, which further decelerates antiprotons ejected from the Antiproton Decelerator (AD). Starting from a momentum of 100 MeV/c (kinetic energy 5.3 MeV), the RFQD delivers very-low-energy antiprotons, adjustable between 10 and 110 keV, to the experiment ASACUSA. In picture _02, the view from the upstream end shows its 4-rod structure, traversing 35 resonator chambers formed by the vertical partitions. The tank has an inner diameter of 390 mm and is pumped to a vacuum of a few E-8 Torr.

  14. Evaluation of heating uniformity in radio frequency heating systems using carrot and radish

    Science.gov (United States)

    Kong, Ling; Zhang, Min; Wang, Yuchuan; Adhikari, Benu; Yang, Zaixing

    2016-10-01

    Lack of heating uniformity is a major problem impeding the broader adaptation of radio frequency heaters in industrial applications. The overall aim of this study was to evaluate the uniformity of heating or temperature distribution within food samples (three different carrot and one radish rectangles) placed vertically and horizontally within a radio frequency heating cavity. The intensity of the electric field in radio frequency was found to be symmetrical. The temperatures at the vertically top positions were lower than the vertically bottom positions at the equidistance from the vertical center with the highest was at the vertically central position. The rate of temperature rise at all the positions were higher in taller (higher mass) than the shorter (lower mass) rectangles of carrots. The temperatures at the corners and edges were lower than at the cross sectionally central positions at all the heights tested in both carrots and radishes. The rate of temperature rise at all the vertical positions was higher in radish rectangles than in the carrot rectangles of the same dimensions. The similarity of temperature distribution in carrot and radish rectangles suggested that the heating patterns and uniformity in carrots and radishes in RF heating were almost the same.

  15. Implementasi Simple Additive Weighting Untuk Monitoring Aktivitas Perkuliahan Dengan Menggunakan Radio Frequency Identification

    Directory of Open Access Journals (Sweden)

    Ashari Darmawan

    2017-05-01

    Full Text Available Monitoring of learning activities has a very important role to improve the quality of education in University. The research  aims to develop a monitoring system of learning activities in real time by using simple additive weighting and radio frequency identification technology.A simple additive weighting method is used to determine the weighting of each criterion involved in the system, while radio frequency identification technology is used electronically to identify and store learning activity information. Monitoring system built using learning activities data in the room and lecturer activities using radio frequency identification tag in real time. The results of the system include the recording of monitoring data of lecturing activities that produce lecturer attendance reports on each class in real  time, thus making efficient the time, effort and cost. The system also produces a ranking of lecturer discipline on each of the criteria that gives the difference of outcomes among the consistent lecturers present on schedule with inconsistent lecturers present on schedule. The results of monitoring of lecture activities can be used for university leaders as a decision-making material quickly based on actual data in real time to improve the quality of the learning process.

  16. A Framework for Sediment Particle Tracking via Radio Frequency IDentification (RFID)

    Science.gov (United States)

    Tsakiris, Achilleas; Papanicolaou, Thanos; Abban, Benjamin

    2016-04-01

    The study of sedimentary and morphodynamic processes in riverine environments has recently been shifting from the traditional Eulerian, static perspective to a Lagrangian perspective, which considers the movement characteristics of the individual transported particles, such as their travel and resting distance and time. The Lagrangian framework, in turn allows to better study processes such as bedload particle diffusion, erosion and deposition within a river reach, to more accurately predict bedload fluxes especially through the use of stochastic Discrete Particle models. A technology that goes hand-in-hand with this Lagrangian perspective is Radio Frequency IDentification (RFID), which has been recently applied for tracking the movement of tagged sediment particles within the river continuum. RFID allows the wireless, bidirectional exchange of information between a base station, known as the reader, with a typically large number of transponders (or tags) via an (excitation) antenna. RFID allows essentially the unique, wireless detection and identification of a transponder over a distance. The goal of this study is to further enhance the utility of RFID in riverine applications by developing a framework that allows extracting the 3D location of RFID tagged sediment particles in nearly real-time. To address the goal of this coupled theoretical and experimental study, a semi-theoretical approach based on antenna inductive coupling was combined with experimental measurements for developing a relationship that provides an estimate of the distance between a tagged particle and the antenna using the Return Signal Strength Indication (RSSI). The RSSI quantifies the magnetic energy transmitted from the transponder to the antenna. The RFID system used in this study was a passive, Low-Frequency (LF) system, which ensured that the LF radio waves could penetrate through the river bed material. The RSSI of the signal transmitted from each transponder was measured with an

  17. Observation of a variable sub-THz radiation driven by a low energy electron beam from a thermionic rf electron gun

    Directory of Open Access Journals (Sweden)

    A. V. Smirnov

    2015-09-01

    Full Text Available We report observations of an intense sub-THz radiation extracted from a ∼3  MeV electron beam with a flat transverse profile propagating between two parallel oversized copper gratings with side openings. Low-loss radiation outcoupling is accomplished using a horn antenna and a miniature permanent magnet separating sub-THz and electron beams. A tabletop experiment utilizes a radio frequency thermionic electron gun delivering a thousand momentum-chirped microbunches per macropulse and an alpha-magnet with a movable beam scraper producing sub-mm microbunches. The radiated energy of tens of micro-Joules per radio frequency macropulse is demonstrated. The frequency of the radiation peak was generated and tuned across two frequency ranges: (476–584 GHz with 7% instantaneous spectrum bandwidth, and (311–334 GHz with 38% instantaneous bandwidth. This prototype setup features a robust compact source of variable frequency, narrow bandwidth sub-THz pulses.

  18. Effect of pulsed discharge on the ignition of pulse modulated radio frequency glow discharge at atmospheric pressure

    Science.gov (United States)

    Qiu, Shenjie; Guo, Ying; Han, Qianhan; Bao, Yun; Zhang, Jing; Shi, J. J.

    2018-01-01

    A pulsed discharge is introduced between two sequential pulse-modulated radio frequency glow discharges in atmospheric helium. The dependence of radio frequency discharge ignition on pulsed discharge intensity is investigated experimentally with the pulse voltage amplitudes of 650, 850, and 1250 V. The discharge characteristics and dynamics are studied in terms of voltage and current waveforms, and spatial-temporal evolution of optical emission. With the elevated pulsed discharge intensity of two orders of magnitude, the ignition of radio frequency discharge is enhanced by reducing the ignition time and achieving the stable operation with a double-hump spatial profile. The ignition time of radio frequency discharge is estimated to be 2.0 μs, 1.5 μs, and 1.0 μs with the pulse voltage amplitudes of 650, 850, and 1250 V, respectively, which is also demonstrated by the spatial-temporal evolution of optical emission at 706 and 777 nm.

  19. Feasibility of Radio Frequency Identification (RFID) and Item Unique Identification (IUID) in the Marine Corps Small Arms Weapons Tracking System

    Science.gov (United States)

    2008-12-04

    the potential ability to hack in and retrieve valued information. Therefore, outside RFID readers have the potential = = ^Åèìáëáíáçå=oÉëÉ~êÅÜ...Feasibility of Radio Frequency Identification ( RFID ) and Item Unique Identification (IUID) in the Marine Corps Small Arms Weapons Tracking...REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Feasibility of Radio Frequency Identification ( RFID ) and Item Unique

  20. Discrimination between weaned and unweaned Atlantic cod (Gadus morhua in capture-based aquaculture (CBA by X-ray imaging and radio-frequency metal detector.

    Directory of Open Access Journals (Sweden)

    Ekrem Misimi

    Full Text Available The aim of this study was to investigate the feasibility of two detection methods for use in discrimination and sorting of adult Atlantic cod (about 2 kg in the small scale capture-based aquaculture (CBA. Presently, there is no established method for discrimination of weaned and unweaned cod in CBA. Generally, 60-70% of the wild-caught cod in the CBA are weaned into commercial dry feed. To increase profitability for the fish farmers, unweaned cod must be separated from the stock, meaning the fish must be sorted into two groups - unweaned and weaned from moist feed. The challenges with handling of large numbers of fish in cages, defined the limits of the applied technology. As a result, a working model was established, focusing on implementing different marking materials added to the fish feed, and different technology for detecting the feed presence in the fish gut. X-ray imaging in two modes (planar and dual energy band and sensitive radio-frequency metal detection were the detection methods that were chosen for the investigations. Both methods were tested in laboratory conditions using dead fish with marked feed inserted into the gut cavity. In particular, the sensitive radio-frequency metal detection method with carbonyl powder showed very promising results in detection of marked feed. Results show also that Dual energy band X-ray imaging may have potential for prediction of fat content in the feed. Based on the investigations it can be concluded that both X-ray imaging and sensitive radio-frequency metal detector technology have the potential for detecting cod having consumed marked feed. These are all technologies that may be adapted to large scale handling of fish from fish cages. Thus, it may be possible to discriminate between unweaned and weaned cod in a large scale grading situation. Based on the results of this study, a suggestion for evaluation of concept for in-situ sorting system is presented.

  1. Discrimination between Weaned and Unweaned Atlantic Cod (Gadus morhua) in Capture-Based Aquaculture (CBA) by X-Ray Imaging and Radio-Frequency Metal Detector

    Science.gov (United States)

    Misimi, Ekrem; Martinsen, Svein; Mathiassen, John Reidar; Erikson, Ulf

    2014-01-01

    The aim of this study was to investigate the feasibility of two detection methods for use in discrimination and sorting of adult Atlantic cod (about 2 kg) in the small scale capture-based aquaculture (CBA). Presently, there is no established method for discrimination of weaned and unweaned cod in CBA. Generally, 60–70% of the wild-caught cod in the CBA are weaned into commercial dry feed. To increase profitability for the fish farmers, unweaned cod must be separated from the stock, meaning the fish must be sorted into two groups – unweaned and weaned from moist feed. The challenges with handling of large numbers of fish in cages, defined the limits of the applied technology. As a result, a working model was established, focusing on implementing different marking materials added to the fish feed, and different technology for detecting the feed presence in the fish gut. X-ray imaging in two modes (planar and dual energy band) and sensitive radio-frequency metal detection were the detection methods that were chosen for the investigations. Both methods were tested in laboratory conditions using dead fish with marked feed inserted into the gut cavity. In particular, the sensitive radio-frequency metal detection method with carbonyl powder showed very promising results in detection of marked feed. Results show also that Dual energy band X-ray imaging may have potential for prediction of fat content in the feed. Based on the investigations it can be concluded that both X-ray imaging and sensitive radio-frequency metal detector technology have the potential for detecting cod having consumed marked feed. These are all technologies that may be adapted to large scale handling of fish from fish cages. Thus, it may be possible to discriminate between unweaned and weaned cod in a large scale grading situation. Based on the results of this study, a suggestion for evaluation of concept for in-situ sorting system is presented. PMID:24743448

  2. Discrimination between weaned and unweaned Atlantic cod (Gadus morhua) in capture-based aquaculture (CBA) by X-ray imaging and radio-frequency metal detector.

    Science.gov (United States)

    Misimi, Ekrem; Martinsen, Svein; Mathiassen, John Reidar; Erikson, Ulf

    2014-01-01

    The aim of this study was to investigate the feasibility of two detection methods for use in discrimination and sorting of adult Atlantic cod (about 2 kg) in the small scale capture-based aquaculture (CBA). Presently, there is no established method for discrimination of weaned and unweaned cod in CBA. Generally, 60-70% of the wild-caught cod in the CBA are weaned into commercial dry feed. To increase profitability for the fish farmers, unweaned cod must be separated from the stock, meaning the fish must be sorted into two groups - unweaned and weaned from moist feed. The challenges with handling of large numbers of fish in cages, defined the limits of the applied technology. As a result, a working model was established, focusing on implementing different marking materials added to the fish feed, and different technology for detecting the feed presence in the fish gut. X-ray imaging in two modes (planar and dual energy band) and sensitive radio-frequency metal detection were the detection methods that were chosen for the investigations. Both methods were tested in laboratory conditions using dead fish with marked feed inserted into the gut cavity. In particular, the sensitive radio-frequency metal detection method with carbonyl powder showed very promising results in detection of marked feed. Results show also that Dual energy band X-ray imaging may have potential for prediction of fat content in the feed. Based on the investigations it can be concluded that both X-ray imaging and sensitive radio-frequency metal detector technology have the potential for detecting cod having consumed marked feed. These are all technologies that may be adapted to large scale handling of fish from fish cages. Thus, it may be possible to discriminate between unweaned and weaned cod in a large scale grading situation. Based on the results of this study, a suggestion for evaluation of concept for in-situ sorting system is presented.

  3. Degradation of methylene blue by radio frequency plasmas in water under ultraviolet irradiation.

    Science.gov (United States)

    Maehara, Tsunehiro; Nishiyama, Kyohei; Onishi, Shingo; Mukasa, Shinobu; Toyota, Hiromichi; Kuramoto, Makoto; Nomura, Shinfuku; Kawashima, Ayato

    2010-02-15

    The degradation of methylene blue by radio frequency (RF) plasmas in water under ultraviolet (UV) irradiation was studied experimentally. When the methylene blue solution was exposed to RF plasma, UV irradiation from a mercury vapor lamp enhanced degradation significantly. A lamp without power supply also enhanced degradation since weak UV light was emitted weakly from the lamp due to the excitation of mercury vapor by stray RF power. Such an enhancement is explained by the fact that after hydrogen peroxide is produced via the recombination process of OH radicals around the plasma, OH radicals reproduced from hydrogen peroxide via the photolysis process degrade methylene blue.

  4. High resolution kilometric range optical telemetry in air by radio frequency phase measurement

    Energy Technology Data Exchange (ETDEWEB)

    Guillory, Joffray; García-Márquez, Jorge; Truong, Daniel; Wallerand, Jean-Pierre [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Šmíd, Radek [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Institute of Scientific Instruments of the CAS, Kralovopolska 147, 612 64 Brno (Czech Republic); Alexandre, Christophe [Centre d’Études et de Recherche en Informatique et Communications (CEDRIC), Cnam, 292 rue St-Martin, 75003 Paris (France)

    2016-07-15

    We have developed an optical Absolute Distance Meter (ADM) based on the measurement of the phase accumulated by a Radio Frequency wave during its propagation in the air by a laser beam. In this article, the ADM principle will be described and the main results will be presented. In particular, we will emphasize how the choice of an appropriate photodetector can significantly improve the telemeter performances by minimizing the amplitude to phase conversion. Our prototype, tested in the field, has proven its efficiency with a resolution better than 15 μm for a measurement time of 10 ms and distances up to 1.2 km.

  5. Stabilized operation of the Spallation Neutron Source radio-frequency quadrupole

    Directory of Open Access Journals (Sweden)

    Sang-ho Kim

    2010-07-01

    Full Text Available The Spallation Neutron Source (SNS radio-frequency quadrupole (RFQ had resonance control instabilities at duty factors higher than approximately 4%. Systematic investigations have been carried out to understand the cause of the instability and to ensure the operational stability of the RFQ. The most critical source of the instability is revealed to be an interaction between hydrogen released by beam bombardments and the RFQ rf field resulting in a discharge, which consumes additional rf power and could cause the RFQ to operate in an unstable region. This paper reports improvement of the SNS RFQ operational stability based on the findings during the SNS operation.

  6. Electron properties and air mixing in radio frequency driven argon plasma jets at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Gessel, Bram van; Bruggeman, Peter [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Brandenburg, Ronny [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany)

    2013-08-05

    A time modulated radio frequency (RF) plasma jet operated with an Ar mixture is investigated by measuring the electron density and electron temperature using Thomson scattering. The measurements have been performed spatially resolved for two different electrode configurations and as a function of the plasma dissipated power and air concentration admixed to the Ar. Time resolved measurements of electron densities and temperatures during the RF cycle and after plasma power switch-off are presented. Furthermore, the influence of the plasma on the air entrainment into the effluent is studied using Raman scattering.

  7. Indication of radio frequency interference (RFI) sources for solar burst monitoring in Malaysia

    Science.gov (United States)

    Hamidi, Z. S.; Abidin, Z. Z.; Ibrahim, Z. A.; Shariff, N. N. M.

    2012-06-01

    Apart of monitoring the Sun project, the Radio Frequency Interference (RFI) surveying in the region of (1-1200) MHz has been conducted. The main objective of this surveying is to test and qualify the potential of monitoring a continuous radio emission of Solar in Malaysia. This work is also an initiative of International Space Weather Initiative (ISWI) project where Malaysia is one of the country that participate a e-Callisto Spectrometer network in order to study the behavior of Solar radio burst in frequency of (45-800) MHz region which will be install in this October. Detail results will indicate the potential of monitoring a solar in Malaysia.

  8. Distributed fiber temperature and strain sensor using coherent radio-frequency detection of spontaneous Brillouin scattering

    Science.gov (United States)

    Geng, Jihong; Staines, Sean; Blake, Mike; Jiang, Shibin

    2007-08-01

    A novel technique that enables coherent detection of spontaneous Brillouin scattering in the radio-frequency (<500 MHz) region with excellent long-term stability has been demonstrated for distributed measurements of temperature and strain in long fiber. An actively stabilized single-frequency Brillouin fiber laser with extremely low phase noise and intensity noise is used as a well-defined, frequency-shifted local oscillator for the heterodyne detection, yielding measurements of spontaneous Brillouin scattering with high frequency stability. Based on this approach, a highly stable real-time fiber sensor for distributed measurements of both temperature and strain over long fiber has been developed utilizing advanced digital signal processing techniques.

  9. Improvement on control system of the JT-60 radio frequency heating system

    Energy Technology Data Exchange (ETDEWEB)

    Shinozaki, Shin-ichi; Moriyama, Shinichi; Hiranai, Shinichi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Sato, Fumiaki [Nippon Advanced Technology Co., Ltd., Tokai, Ibaraki (Japan)

    2003-03-01

    On the JT-60 radio frequency (RF) heating system, the decrease in the activity ratio was a problem because of the deterioration of the control system. To improve the reliability, we replaced CAMAC system for a power injection control system, which was a main cause of the trouble, with the microprocessor system. And, a function of computer supported programming function of RF power injection form was introduced, which contributed to reduce a load of operators. Furthermore, personal computers with network communication were introduced to improve a maintenance ability of the control system. As a result, the activity ratio of the RF heating system was improved significantly. (author)

  10. Radio Frequency Interference Detection and Mitigation Techniques Using Data from Ecosar 2014 Flight Campaign

    Science.gov (United States)

    Osmanoglu, Batuhan; Rincon, Rafael F.; Lee, SeungKuk; Fatoyinb, Temilola; Bollian, Tobias

    2016-01-01

    Radio frequency interference (RFI) has strong influence on wide band airborne radar systems, especially operaingat L-band (1-2 GHz) or lower frequencies. EcoSAR is a P-band digital beamforming radar system, and RFI has tobe removed from raw echoes to obtain science quality data. In this paper we describe the current methodologyused to tackle RFI with EcoSAR, and provide an example on its performance. Finally, we discuss the advantagesand disadvantages of the method and mention potential improvements.

  11. Measurement of radio-frequency temporal phase modulation using spectral interferometry

    Science.gov (United States)

    Jachura, Michał; Szczepanek, Jan; Wasilewski, Wojciech; Karpiński, Michał

    2018-02-01

    We present an optical method to measure radio-frequency electro-optic phase modulation profiles by employing spectrum-to-time mapping realized by highly chirped optical pulses. We directly characterize temporal phase modulation profiles of up to 12.5 GHz bandwidth, with temporal resolution comparable to high-end electronic oscilloscopes. The presented optical setup is a valuable tool for direct characterization of complex temporal electro-optic phase modulation profiles, which is indispensable for practical realization of deterministic spectral-temporal reshaping of quantum light pulses.

  12. Particle simulation of radio frequency waves with fully-kinetic ions and gyrokinetic electrons

    Science.gov (United States)

    Lin, Jingbo; Zhang, Wenlu; Liu, Pengfei; Lin, Zhihong; Dong, Chao; Cao, Jintao; Li, Ding

    2018-01-01

    A toroidal particle-in-cell (PIC) code, suitable for investigating nonlinear phenomena in radio frequency (RF) heating and current drive, is developed and verified thereafter through a series of fidelity tests for field solvers and single particle motions in toroidal geometry, where simulation results show good coincidence with analytical prediction. The RF capability is then demonstrated through the integrated benchmarks with linear lower hybrid wave and ion Bernstein wave theory in cylindrical geometry, where the analytic result is easily available. The frequency and mode structure in the simulations agree well with the theoretical prediction.

  13. Radio Frequency Interference Mitigation for the Planned SMAP Radar and Radiometer

    Science.gov (United States)

    Spencer, Michael; Chan, Samuel; Belz, Eric; Piepmeier, Jeffrey; Mohammed, Priscilla; Kim, Edward; Johnson, Joel T.

    2011-01-01

    NASA's planned SMAP mission will utilize a radar operating in a band centered on 1.26 GHz and a co-observing radiometer operating at 1.41 GHz to measure surface soil moisture. Both the radar and radiometer sub-systems are susceptible to radio frequency interference (RFI). Any significant impact of such interference requires mitigation in order to avoid degradation in the SMAP science products. Studies of RFT detection and mitigation methods for both the radar and radiometer are continuing in order to assess the risk to mission products and to refine the performance achieved.

  14. Low-beam-loss design of a compact, high-current deuteron radio frequency quadrupole accelerator

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2004-10-01

    Full Text Available A 201.5 MHz, 50 mA, 2.0 MeV deuteron radio frequency quadrupole accelerator is proposed as the neutron generator for the neutron experiment facility project at Peking University, China. Based on better understanding of beam losses, some new optimization procedures concerning both longitudinal and transverse dynamics are adopted. Accordingly, the beam transmission efficiency is improved from 91.2% to 98.3% and the electrode length is shortened from 2.91 to 2.71 m. The fundamental physical analyses are performed to look inside the new design recipe and explain why it works.

  15. A Radio-Frequency-over-Fiber link for large-array radio astronomy applications

    Science.gov (United States)

    Mena, J.; Bandura, K.; Cliche, J.-F.; Dobbs, M.; Gilbert, A.; Tang, Q. Y.

    2013-10-01

    A prototype 425-850 MHz Radio-Frequency-over-Fiber (RFoF) link for the Canadian Hydrogen Intensity Mapping Experiment (CHIME) is presented. The design is based on a directly modulated Fabry-Perot (FP) laser, operating at ambient temperature, and a single-mode fiber. The dynamic performance, gain stability, and phase stability of the RFoF link are characterized. Tests on a two-element interferometer built at the Dominion Radio Astrophysical Observatory for CHIME prototyping demonstrate that RFoF can be successfully used as a cost-effective solution for analog signal transport on the CHIME telescope and other large-array radio astronomy applications.

  16. Improved eigensubspace-based approach for radio frequency interference filtering of synthetic aperture radar images

    Science.gov (United States)

    Zhou, Chunhui; Li, Fei; Li, Ning; Zheng, Huifang; Wang, Robert; Wang, Xiangyu

    2017-04-01

    The radio frequency interference (RFI) has an adverse effect on the useful signals, which can degrade the image quality seriously. An improved eigensubspace-based approach for RFI filtering of synthetic aperture radar images is developed. In the preprocessing stage of the proposed approach, the data sets that need subsequent processing can be selected in both frequency and time domain. Then, the data can be processed by the traditional eigensubspace-based approach. Compared with the traditional eigensubspace-based approach, our approach can work more efficiently and effectively.

  17. Solid state generator for powerful radio frequency ion sources in neutral beam injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, W.; Fantz, U.; Heinemann, B.; Franzen, P.

    2015-02-15

    Radio frequency ion sources used in neutral beam injection systems (NBI) of fusion machines are currently supplied by self-excited RF generators. These generators have both a low power efficiency and a limited frequency stability, therefore transistorized amplifiers are being considered for the power supply of the next generation of RF sources. A 75 kW generator, originally designed for broadcasting, has been tested with a negative ion source. High operational reliability and a very good matching to the plasma load has been demonstrated. These results make this generator type a very promising candidate for future NBI systems.

  18. Single particle dynamics in a radio-frequency produced plasma sheath

    Science.gov (United States)

    Rubin-Zuzic, M.; Nosenko, V.; Zhdanov, S.; Ivlev, A.; Thomas, H.; Khrapak, S.; Couedel, L.

    2018-01-01

    Recently different research groups have investigated the motion of a single dust particle levitated in a rf plasma. Here we describe a highly resolved experiment where a single spherical melamine formaldehyde microparticle is suspended in the plasma sheath above the lower electrode of a capacitively coupled radio-frequency discharge at controlled pressure, power and neutral gas flow rate. The particle's horizontal oscillation is investigated, from which its neutral gas damping rate, kinetic temperature and eigenfrequency of the potential trap are measured. Compared to prior experiments we report about inhomogeneous and anisotropic velocity variations.

  19. Validation of Radio Frequency Telemetry Concept in the Presence of Biological Tissue-Like Stratified Media

    Science.gov (United States)

    Miranda, Felix A.; Simons, Rainee N.; Haal, David G.

    2004-01-01

    In this paper we discuss a novel radio frequency (RF) telemetry concept for biomedical applications. The concept consists of a miniaturized spiral inductor/antenna for bio-MEMS sensors and an external pick-up antenna integrated into a handheld device. The measured relative signal strength in the presence of biological phantoms ranged from 5.9 to 7.5 dB for antenna separations of 5 and 10 cm. These relative signal strengths are easily measurable, therefore validating the RF telemetry concept for biomedical applications.

  20. Occupational exposure to radio frequency/microwave radiation and the risk of brain tumors

    DEFF Research Database (Denmark)

    Berg, Gabriele; Spallek, Jacob; Schüz, Joachim

    2006-01-01

    It is still under debate whether occupational exposure to radio frequency/microwave electromagnetic fields (RF/MW-EMF) contributes to the development of brain tumors. This analysis examined the role of occupational RF/MW-EMF exposure in the risk of glioma and meningioma. A population-based, case....... No significant association between occupational exposure to RF/MW-EMF and brain tumors was found. For glioma, the adjusted odds ratio for highly exposed persons compared with persons not highly exposed was 1.21 (95% confidence interval: 0.69, 2.13); for meningioma, it was 1.34 (95% confidence interval: 0.64, 2...

  1. Radio Frequency Interference Detection for Passive Remote Sensing Using Eigenvalue Analysis

    Science.gov (United States)

    Schoenwald, Adam; Kim, Seung-Jun; Mohammed-Tano, Priscilla

    2017-01-01

    Radio frequency interference (RFI) can corrupt passive remote sensing measurements taken with microwave radiometers. With the increasingly utilized spectrum and the push for larger bandwidth radiometers, the likelihood of RFI contamination has grown significantly. In this work, an eigenvalue-based algorithm is developed to detect the presence of RFI and provide estimates of RFI-free radiation levels. Simulated tests show that the proposed detector outperforms conventional kurtosis-based RFI detectors in the low-to-medium interferece-to-noise-power-ratio (INR) regime under continuous wave (CW) and quadrature phase shift keying (QPSK) RFIs.

  2. Nanoindentation behaviors of amorphous carbon films containing nanocrystalline graphite and diamond clusters prepared by radio frequency sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Xue [Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan); Nose, Kenji [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan); Diao, Dongfeng, E-mail: dfdiao@szu.edu.cn [Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Nanosurface Science and Engineering Research Institute, Shenzhen University, Shenzhen 518060 (China); Yoshida, Toyonobu [Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan)

    2013-05-15

    Amorphous carbon (a-C) films were prepared by a radio-frequency sputtering method. Nano structures in the films were controlled by changing the ion irradiation energy and deposition temperature. It was found that nanocrystalline graphite and diamond clusters were embedded in the pure amorphous structure with sizes of approximately 5 nm. a-C films contained nanocrystalline graphite clusters (a-C:NCG) were obtained with the ion energy ranging from 50 to 120 eV and temperature in 300–370 K. a-C film contained nanocrystalline diamond clusters (a-C:NCD) was obtained with 120 eV at 570 K. Nanoindentation behaviors of these carbon films were compared with pure amorphous structured carbon film. The percentage of elastic recoveries of a-C:NCD, a-C, and a-C:NCG films were obtained to be 81.9%, 84.3%, and 87.5%, respectively. Pop-in steps with about 3 nm displacement appeared in loading curves for a-C:NCG film, and 10 nm for a-C:NCD film. These results showed that the nanoindentation behaviors of amorphous carbon film containing cross-linked nanocrystalline graphite clusters is better than that of diamond clusters.

  3. Kinetics of electrons and neutral particles in radio-frequency transformer coupled plasma H- ion source at Seoul National University

    Science.gov (United States)

    Chung, K. J.; Dang, J. J.; Kim, J. Y.; Cho, W. H.; Hwang, Y. S.

    2016-10-01

    In volume production H- ion sources, control of electron temperature is essential due to its close correlation with the generation of vibrationally-excited hydrogen molecules in the driver region as well as the generation of H- ions by dissociative attachment in the extraction region. In the ion source group at Seoul National University (SNU) in Korea, a lot of research effort has been made to the development of a volume production H- ion source based on radio-frequency (RF) transformer-coupled plasma (TCP) for long lifetime continuous wave (CW) operation. It has a spiral RF antenna located outside the discharge chamber to generate a plasma with high electron temperature in the driver region and employs a magnetic filter field to prevent high energy electrons from being transported to the extraction region. In this paper, we present the recent progress on understanding of the underlying physics of the RF TCP H- ion source at SNU. Special attention is paid to the characterization of electron kinetics regime for controlling electron energy distribution and the influence of relaxation of neutral particles during the transport across the magnetic filter region. Effect of the degree of dissociation on the production of H- ions is also discussed.

  4. Energy conservation by reducing process variability

    Energy Technology Data Exchange (ETDEWEB)

    Wising, Ulrika; Lafourcade, Sebastien [Pepite S.A., Liege (Belgium); Mack, Philippe [Pepite Technologies Inc., Montreal (Canada)

    2011-12-21

    Energy conservation is becoming an increasingly important instrument to stay competitive in today is increasingly global market. Important investments have been made in infrastructure and personnel in order to improve the management of energy such as increased metering, energy dashboards, energy managers, etc. Despite these investments, the results have not materialized and there is still a significant potential to further reduce energy consumption. In this paper a new methodology will be presented that helps industry better operate existing assets in order to reduce energy consumption, without having to make capital investments. The methodology uses a combination of advanced data analysis tools and a specific implementation scheme that has lead to significant savings in industry. The advanced data analysis tools are used to analyze the variability of the process in order to assess when the plant has been operated well or not so well in the past. By finding the root causes of these variations and the key variables that can explain them, improved operating guidelines and models can be developed and implemented. The specific implementation scheme is an important part of the methodology as it involves the people operating the plant. Several user cases will be presented showing an energy conservation of between 10%-20% without capital investments necessary. (author)

  5. An Approach to Near Field Data Selection in Radio Frequency Identification

    Science.gov (United States)

    Winkworth, Robert D.

    Personal identification is needed in many civil activities, and the common identification cards, such as a driver's license, have become the standard document de facto. Radio frequency identification has complicated this matter. Unlike their printed predecessors, contemporary RFID cards lack a practical way for users to control access to their individual fields of data. This leaves them more available to unauthorized parties, and more prone to abuse. Here, then was undertaken a means to test a novel RFID card technology that allows overlays to be used for reliable, reversible data access settings. Similar to other proposed switching mechanisms, it offers advantages that may greatly improve outcomes. RFID use is increasing in identity documents such as drivers' licenses and passports, and with it concern over the theft of personal information, which can enable unauthorized tracking or fraud. Effort put into designing a strong foundation technology now may allow for widespread development on them later. In this dissertation, such a technology was designed and constructed, to drive the central thesis that selective detuning could serve as a feasible, reliable mechanism. The concept had been illustrated effective in limiting access to all fields simultaneously before, and was here effective in limiting access to specific fields selectively. A novel card was produced in familiar dimensions, with an intuitive interface by which users may conceal the visible print of the card to conceal the wireless emissions it allows. A discussion was included of similar technologies, involving capacitive switching, that could further improve the outcomes if such a product were put to large-scale commercial fabrication. The card prototype was put to a battery of laboratory tests to measure the degree of independence between data fields and the reliability of the switching mechanism when used under realistically variable coverage, demonstrating statistically consistent performance in

  6. An unshielded radio-frequency atomic magnetometer with sub-femtoTesla sensitivity

    Directory of Open Access Journals (Sweden)

    David A. Keder

    2014-12-01

    Full Text Available We demonstrate a radio-frequency potassium-vapor magnetometer operating with sensitivities of 0.3 fT/ Hz at 0.5 MHz and 0.9 fT/ Hz at 1.31 MHz in the absence of radio-frequency and mu-metal or magnetic shielding. The use of spatially separated magnetometers, two voxels within the same cell, permits for the subtraction of common mode noise and the retention of a gradient signal, as from a local source. At 0.5 MHz the common mode noise was white and measured to be 3.4 fT/ Hz ; upon subtraction the noise returned to the values observed when the magnetometer was shielded. At 1.31 MHz, the common mode noise was from a nearby radio station and was reduced by a factor of 33 upon subtraction, limited only by the radio signal picked up by receiver electronics. Potential applications include in-the-field low-field magnetic resonance, such as the use of nuclear quadrupole resonance for the detection of explosives.

  7. Homogeneous spectral spanning of terahertz semiconductor lasers with radio frequency modulation.

    Science.gov (United States)

    Wan, W J; Li, H; Zhou, T; Cao, J C

    2017-03-08

    Homogeneous broadband and electrically pumped semiconductor radiation sources emitting in the terahertz regime are highly desirable for various applications, including spectroscopy, chemical sensing, and gas identification. In the frequency range between 1 and 5 THz, unipolar quantum cascade lasers employing electron inter-subband transitions in multiple-quantum-well structures are the most powerful semiconductor light sources. However, these devices are normally characterized by either a narrow emission spectrum due to the narrow gain bandwidth of the inter-subband optical transitions or an inhomogeneous broad terahertz spectrum from lasers with heterogeneous stacks of active regions. Here, we report the demonstration of homogeneous spectral spanning of long-cavity terahertz semiconductor quantum cascade lasers based on a bound-to-continuum and resonant phonon design under radio frequency modulation. At a single drive current, the terahertz spectrum under radio frequency modulation continuously spans 330 GHz (~8% of the central frequency), which is the record for single plasmon waveguide terahertz lasers with a bound-to-continuum design. The homogeneous broadband terahertz sources can be used for spectroscopic applications, i.e., GaAs etalon transmission measurement and ammonia gas identification.

  8. Use of a controlled subdermal radio frequency thermistor for treating the aging neck: Consensus recommendations.

    Science.gov (United States)

    Kinney, Brian M; Andriessen, Anneke; DiBernardo, Barry E; Bloom, Jason; Branson, Dennis F; Gentile, Richard D; Goldberg, David J; Lorenc, Paul Z; Nestor, Mark; Wu, Douglas

    2017-12-01

    A new temperature-controlled device has been used as a percutaneous radio frequency probe to treat lax submental and other facial areas. It has significant advantages over other esthetic devices as it provides the dual benefit of fat lipolysis and skin tightening. Our goal here is to present consensus recommendations for treating the aging neck. A panel of 11 expert physicians convened in Dallas, Texas, on October 15, 2016 to arrive at a consensus on the best current practice for submental skin tightening and contour improvement. Prior to the meeting, a comprehensive review of the literature was performed and a survey was sent to esthetic dermatologists and plastic surgeons who were queried about various aspects of neck rejuvenation. The literature search revealed 10 different technologies for neck rejuvenation evaluated in double-blind (n = 2) and single-blind (n = 1) clinical trials and other clinical evaluations (n = 21). The survey was sent via an email to 1248 individuals and was completed by 92 respondents. Review of the data and discussion by meeting attendees generated eight consensus recommendations. Subdermal monopolar radio frequency represents an effective means for disrupting fat volume and skin tightening of the face, neck, and jawline. For suitable patients, this treatment can be used to achieve significant esthetic improvements.

  9. Radio Frequency Transistors and Circuits Based on CVD MoS2.

    Science.gov (United States)

    Sanne, Atresh; Ghosh, Rudresh; Rai, Amritesh; Yogeesh, Maruthi Nagavalli; Shin, Seung Heon; Sharma, Ankit; Jarvis, Karalee; Mathew, Leo; Rao, Rajesh; Akinwande, Deji; Banerjee, Sanjay

    2015-08-12

    We report on the gigahertz radio frequency (RF) performance of chemical vapor deposited (CVD) monolayer MoS2 field-effect transistors (FETs). Initial DC characterizations of fabricated MoS2 FETs yielded current densities exceeding 200 μA/μm and maximum transconductance of 38 μS/μm. A contact resistance corrected low-field mobility of 55 cm(2)/(V s) was achieved. Radio frequency FETs were fabricated in the ground-signal-ground (GSG) layout, and standard de-embedding techniques were applied. Operating at the peak transconductance, we obtain short-circuit current-gain intrinsic cutoff frequency, fT, of 6.7 GHz and maximum intrinsic oscillation frequency, fmax, of 5.3 GHz for a device with a gate length of 250 nm. The MoS2 device afforded an extrinsic voltage gain Av of 6 dB at 100 MHz with voltage amplification until 3 GHz. With the as-measured frequency performance of CVD MoS2, we provide the first demonstration of a common-source (CS) amplifier with voltage gain of 14 dB and an active frequency mixer with conversion gain of -15 dB. Our results of gigahertz frequency performance as well as analog circuit operation show that large area CVD MoS2 may be suitable for industrial-scale electronic applications.

  10. Protection of Hawaii’s observatories from light pollution and radio frequency interference

    Science.gov (United States)

    Wainscoat, Richard

    2015-08-01

    The island of Hawaii is home to Maunakea Observatory, the largest collection of optical and infrared telescopes in the world. Haleakala Observatory on Maui is also an excellent observing site, and is home to the Pan-STARRS telescopes, the Faulkes Telescope North, solar telescopes, and military telescopes.The dark night sky over Maunakea has been well protected by a strong lighting ordinance, and remains very dark. The National Park Service night sky team recently visited Maunakea, and found it to have a darker night sky than any of the US National Parks that they have visited.Haleakala is more threatened, because Maui has a weaker lighting ordinance, and it is a smaller island, meaning that people live and work closer to the telescopes. Haleakala is also closer to Honolulu, and the urban glow from Honolulu contributes to an artificially bright sky in the northwest direction. Although there is no astronomical research done on the island of Kauai, it has some of the best lighting in the world, because endangered birds on Kauai become confused and disoriented by unshielded lights.The county and state lighting regulations will be described in detail. Enforcement issues will also be discussed.The efforts that have been made to protect Maunakea observatory from radio frequency interference, and to reduce radio frequency interference on Haleakala will also be described.

  11. Characterization of a Prototype Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

    Science.gov (United States)

    Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

    2007-01-01

    The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for interspacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of the medium, moving platforms, and radiated power. The Path Emulator for Radio Frequency Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

  12. Resonant-frequency discharge in a multi-cell radio frequency cavity

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, S; Upadhyay, J; Mammosser, J; Nikolic, M; Vuskovic, L

    2014-11-07

    We are reporting experimental results on microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency (SRF) cryomodule (in situ operation). This discharge offers an efficient mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the problems related to generation and sustaining the multi-cell cavity plasma, which are breakdown and resonant detuning. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal.

  13. Analysis of Radio Frequency Blackout for a Blunt-Body Capsule in Atmospheric Reentry Missions

    Directory of Open Access Journals (Sweden)

    Yusuke Takahashi

    2016-01-01

    Full Text Available A numerical analysis of electromagnetic waves around the atmospheric reentry demonstrator (ARD of the European Space Agency (ESA in an atmospheric reentry mission was conducted. During the ARD mission, which involves a 70% scaled-down configuration capsule of the Apollo command module, radio frequency blackout and strong plasma attenuation of radio waves in communications with data relay satellites and air planes were observed. The electromagnetic interference was caused by highly dense plasma derived from a strong shock wave generated in front of the capsule because of orbital speed during reentry. In this study, the physical properties of the plasma flow in the shock layer and wake region of the ESA ARD were obtained using a computational fluid dynamics technique. Then, electromagnetic waves were expressed using a frequency-dependent finite-difference time-domain method using the plasma properties. The analysis model was validated based on experimental flight data. A comparison of the measured and predicted results showed good agreement. The distribution of charged particles around the ESA ARD and the complicated behavior of electromagnetic waves, with attenuation and reflection, are clarified in detail. It is suggested that the analysis model could be an effective tool for investigating radio frequency blackout and plasma attenuation in radio wave communication.

  14. Influences of the shielding cylinder on the length of radio-frequency cold atmospheric plasma jets

    Science.gov (United States)

    Li, He-Ping; Li, Jing; Zhang, Xiao-Fei; Guo, Heng; Chen, Jian; Department of Engineering Physics Team

    2017-10-01

    Cold atmospheric plasma jets driven by a radio frequency power supply contain abundant species and complex chemical reactions, which have wide applications in the fields of materials processing and modifications, food engineering, bio-medical science, etc. Our previous experiments have shown that the total length of a radio-frequency cold atmospheric plasma (RF-CAP) jet can exceed 1 meter with the shielding of a quartz tube. However, the shielding mechanisms of the solid cylinder has not been studied systematically. In this study, a two-dimensional, quasi-steady fluid model is used to investigate the influences of the shielding tube on the length of the RF-CAP jets under different conditions. The simulation results show that the total jet length grows monotonously; while simultaneously, the jet length out of the tube shows a non-monotonic variation trend, with the increase of the tube length, which is in good agreement with the experimental observations. The shielding mechanisms of the solid cylinder on the RF-CAP jet is also discussed in detail based on the modeling results. This work was supported by the National Natural Science Foundation of China (11475103, 21627812), the National Key Research and Development Program of China (2016YFD0102106) and Tsinghua University Initiative Scientific Program (20161080108).

  15. Exposure of radio officers to radio frequency radiation on Danish merchant ships.

    Science.gov (United States)

    Skotte, J

    1984-12-01

    Exposure of radio officers to radio frequency radiation from telegraphy and telephony equipment on ships was investigated. Eighty-five measurements were made of 12 radio transmitters operating in the 400 kHz to 25 MHz range (power up to 1200 W) and three VHF telephony transmitters in the 150 MHz band. Field measurements were made at positions normally occupied by radio officers approximately 1 m, 0.5 m and 0.25 m from the antenna feed lines. The distance between the radio operator and the measurement location was at least 0.5 m. The ratio of the electric and magnetic field strength squared (MF and HF transmitters) to ANSI C95.1-1982 radio frequency protection guides ranged from 0.001 to 0.26 (geometric mean 0.02) at the location of the seated radio officer's head. A minimum distance of 0.5 m between antenna feed lines and personnel is recommended. This would normally ensure an exposure below the ANSI safety levels.

  16. Exposure of radio officers to radio frequency radiation on Danish merchant ships

    Energy Technology Data Exchange (ETDEWEB)

    Skotte, J.

    1984-12-01

    Exposure of radio officers to radio frequency radiation from telegraphy and telephony equipment on ships was investigated. Eighty-five measurements were made of 12 radio tranmitters operating in the 400 kHz to 25 MHz range (power up to 1200 W) and three VHF telephony transmitters in the 150 MHz band. Field measurments were made at positions normally occupied by radio officers approximately 1 m, 0.5 m and 0.25 m from the antenna feed lines. The distance between the radio operator and the measurement location was at least 0.5 m. The ratio of the electric and magnetic field strength squared (MF and HF transmitters) to ANSI C95.1-1982 radio frequency protection guides ranged from 0.001 to 0.26 (geometric mean 0.02) at the location of the seated radio officer's head. A minimum distance of 0.5 m between antenna feed lines and personnel is recommended. This would normally ensure an exposure below the ANSI safety levels.

  17. Communication Characteristics of Faulted Overhead High Voltage Power Lines at Low Radio Frequencies

    Directory of Open Access Journals (Sweden)

    Nermin Suljanović

    2017-11-01

    Full Text Available This paper derives a model of high-voltage overhead power line under fault conditions at low radio frequencies. The derived model is essential for design of communication systems to reliably transfer information over high voltage power lines. In addition, the model can also benefit advanced systems for power-line fault detection and classification exploiting the phenomenon of changed conditions on faulted power line, resulting in change of low radio frequency signal propagation. The methodology used in the paper is based on the multiconductor system analysis and propagation of electromagnetic waves over the power lines. The model for the high voltage power line under normal operation is validated using actual measurements obtained on 400 kV power line. The proposed model of faulted power lines extends the validated power-line model under normal operation. Simulation results are provided for typical power line faults and typical fault locations. Results clearly indicate sensitivity of power-line frequency response on different fault types.

  18. Enhanced control of the ionization rate in radio-frequency plasmas with structured electrodes via tailored voltage waveforms

    Science.gov (United States)

    Doyle, Scott J.; Lafleur, Trevor; Gibson, Andrew R.; Tian, Peng; Kushner, Mark J.; Dedrick, James

    2017-12-01

    Radio-frequency capacitively coupled plasmas that incorporate structured electrodes enable increases in the electron density within spatially localized regions through the hollow cathode effect (HCE). This enables enhanced control over the spatial profile of the plasma density, which is useful for several applications including materials processing, lighting and spacecraft propulsion. However, asymmetries in the powered and grounded electrode areas inherent to the hollow cathode geometry lead to the formation of a time averaged dc self-bias voltage at the powered electrode. This bias alters the energy and flux of secondary electrons leaving the surface of the cathode and consequentially can moderate the increased localized ionization afforded by the hollow cathode discharge. In this work, two-dimensional fluid-kinetic simulations are used to demonstrate control of the dc self-bias voltage in a dual-frequency driven (13.56, 27.12 MHz), hollow cathode enhanced, capacitively coupled argon plasma over the 66.6–200 Pa (0.5–1.5 Torr) pressure range. By varying the phase offset of the 27.12 MHz voltage waveform, the dc self-bias voltage varies by 10%–15% over an applied peak-to-peak voltage range of 600–1000 V, with lower voltages showing higher modulation. Resulting ionization rates due to secondary electrons within the hollow cathode cavity vary by a factor of 3 at constant voltage amplitude, demonstrating the ability to control plasma properties relevant for maintaining and enhancing the HCE.

  19. Radio frequency measurements of tunnel couplings and singlet–triplet spin states in Si:P quantum dots

    Science.gov (United States)

    House, M. G.; Kobayashi, T.; Weber, B.; Hile, S. J.; Watson, T. F.; van der Heijden, J.; Rogge, S.; Simmons, M. Y.

    2015-01-01

    Spin states of the electrons and nuclei of phosphorus donors in silicon are strong candidates for quantum information processing applications given their excellent coherence times. Designing a scalable donor-based quantum computer will require both knowledge of the relationship between device geometry and electron tunnel couplings, and a spin readout strategy that uses minimal physical space in the device. Here we use radio frequency reflectometry to measure singlet–triplet states of a few-donor Si:P double quantum dot and demonstrate that the exchange energy can be tuned by at least two orders of magnitude, from 20 μeV to 8 meV. We measure dot–lead tunnel rates by analysis of the reflected signal and show that they change from 100 MHz to 22 GHz as the number of electrons on a quantum dot is increased from 1 to 4. These techniques present an approach for characterizing, operating and engineering scalable qubit devices based on donors in silicon. PMID:26548556

  20. Characterization of etch pits found on a large-grain bulk niobium superconducting radio-frequency resonant cavity

    Directory of Open Access Journals (Sweden)

    Xin Zhao

    2010-12-01

    Full Text Available The performance of superconducting radio-frequency (SRF resonant cavities made of bulk niobium is limited by nonlinear localized effects. Surface analysis of regions of higher power dissipation is thus of intense interest. Such areas (referred to as “hotspots” were identified in a large-grain single-cell cavity that had been buffered-chemical polished and dissected for examination by high resolution electron microscopy, electron backscattered diffraction microscopy (EBSD, and optical microscopy. Pits with clearly discernible crystal facets were observed in both “hotspot” and “coldspot” specimens. The pits were found in-grain, at bicrystal boundaries, and on tricrystal junctions. They are interpreted as etch pits induced by crystal defects (e.g. dislocations. All coldspots examined had a qualitatively lower density of etch pits or relatively smooth tricrystal boundary junctions. EBSD mapping revealed the crystal orientation surrounding the pits. Locations with high pit density are correlated with higher mean values of the local average misorientation angle distributions, indicating a higher geometrically necessary dislocation content. In addition, a survey of the samples by energy dispersive x-ray analysis did not show any significant contamination of the samples’ surface. The local magnetic field enhancement produced by the sharp-edge features observed on the samples is not sufficient to explain the observed degradation of the cavity quality factor, which starts at peak surface magnetic field as low as 20 mT.

  1. In situ radio-frequency heating for soil remediation at a former service station: case study and general aspects

    Energy Technology Data Exchange (ETDEWEB)

    Huon, G.; Simpson, T.; Maini, G. [Ecologia Environmental Solutions Ltd., Sittingbourne, Kent (United Kingdom); Holzer, F.; Kopinke, F.D.; Roland, U. [Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, Leipzig (Germany); Will, F. [Total UK, Watford (United Kingdom)

    2012-08-15

    In situ radio-frequency heating (ISRFH) was successfully applied during remediation of a former petrol station. Using a three-electrode array in combination with extraction wells for soil vapor extraction (SVE), pollution consisting mainly of benzene, toluene, ethylbenzene, xylenes, and mineral oil hydrocarbons (in total about 1100 kg) was eliminated from a chalk soil in the unsaturated zone. Specially designed rod electrodes allowed selective heating of a volume of approximately 480 m{sup 3}, at a defined depth, to a mean temperature of about 50 C. The heating drastically increased the extraction rates. After switching off ISRFH, SVE remained highly efficient for some weeks due to the heat-retaining properties of the soil. Comparison of an optimized regime of ISRFH/SVE with conventional ''cold'' SVE showed a reduction of remediation time by about 80 % while keeping the total energy consumption almost constant. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Elimination of transmissible spongiform encephalopathy infectivity and decontamination of surgical instruments by using radio-frequency gas-plasma treatment.

    Science.gov (United States)

    Baxter, H C; Campbell, G A; Whittaker, A G; Jones, A C; Aitken, A; Simpson, A H; Casey, M; Bountiff, L; Gibbard, L; Baxter, R L

    2005-08-01

    It has now been established that transmissible spongiform encephalopathy (TSE) infectivity, which is highly resistant to conventional methods of deactivation, can be transmitted iatrogenically by contaminated stainless steel. It is important that new methods are evaluated for effective removal of protein residues from surgical instruments. Here, radio-frequency (RF) gas-plasma treatment was investigated as a method of removing both the protein debris and TSE infectivity. Stainless-steel spheres contaminated with the 263K strain of scrapie and a variety of used surgical instruments, which had been cleaned by a hospital sterile-services department, were examined both before and after treatment by RF gas plasma, using scanning electron microscopy and energy-dispersive X-ray spectroscopic analysis. Transmission of scrapie from the contaminated spheres was examined in hamsters by the peripheral route of infection. RF gas-plasma treatment effectively removed residual organic residues on reprocessed surgical instruments and gross contamination both from orthopaedic blades and from the experimentally contaminated spheres. In vivo testing showed that RF gas-plasma treatment of scrapie-infected spheres eliminated transmission of infectivity. The infectivity of the TSE agent adsorbed on metal spheres could be removed effectively by gas-plasma cleaning with argon/oxygen mixtures. This treatment can effectively remove 'stubborn' residual contamination on surgical instruments.

  3. Influence of conductivity on the generation of a radio frequency plasma surrounded by bubbles in water

    Energy Technology Data Exchange (ETDEWEB)

    Maehara, T; Honda, S; Inokuchi, C; Mukasa, S; Toyota, H; Nomura, S [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577 (Japan); Kuramoto, M [Integrated Center for Sciences, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577 (Japan); Kawashima, A, E-mail: maehara@phys.sci.ehime-u.ac.jp [Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566 (Japan)

    2011-06-15

    A radio frequency plasma was generated and maintained in water over a wide range of water conductivities (0.2-7000 mS m{sup -1}). The conductivity of water was changed by adding NaCl to it. The size of the plasma increased with conductivity. Although the intensity of the OH(A-X) line monotonically decreased with increasing conductivity, the generation of hydrogen peroxide and the degradation of methylene blue suggested that the number of generated OH radicals decreased with increasing conductivity in the range 0.2-80 mS m{sup -1} and increased in the range 80-7000 mS m{sup -1}. Ultraviolet irradiation was found to enhance the degradation of methylene blue not only in pure water but also in high-conductivity water ({approx_equal}5000 mS m{sup -1}).

  4. Development of a remotely maintainable radio-frequency module for the Compact Ignition Tokamak

    Science.gov (United States)

    Snider, J. D.

    The Compact Ignition Tokamak (CIT) will require reliable remote handling (RH) systems to overcome failures in diagnostic and operational equipment. Oak Ridge National Laboratory (ORNL) is responsible for the ex-vessel remote maintenance systems for the CIT. Part of this effort is performing remote maintenance demonstrations on replicas of various CIT equipment. To ensure successful RH, the machine must be designed with proven remote maintenance features. In the demonstrations, critical remote maintenance features are tested before actual CIT equipment designs are finalized. Designs and procedures required to remotely remove and install a radio-frequency (RF) module from a modplane port on the tokamak were recently demonstrated at ORNL. This testing identified both successful design features for remote maintenance of the RF module and areas that require further development.

  5. Recent research trends of radio-frequency biosensors for biomolecular detection.

    Science.gov (United States)

    Lee, Hee-Jo; Yook, Jong-Gwan

    2014-11-15

    This article reviews radio-frequency (RF) biosensors based on passive and/or active devices and circuits. In particular, we focus on RF biosensors designed for detection of various biomolecules such as biotin-streptavidin, DNA hybridization, IgG, and glucose. The performance of these biosensors has been enhanced by the introduction of various sensing schemes with diverse nanomaterials (e.g., carbon nanotubes, graphene oxide, magnetic and gold nanoparticles, etc.). In addition, the RF biosensing platforms that can be associated with an RF active system are discussed. Finally, the challenges of RF biosensors are presented and suggestions are made for their future direction and prospects. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Cryocooled wideband digital channelizing radio-frequency receiver based on low-pass ADC

    Energy Technology Data Exchange (ETDEWEB)

    Vernik, Igor V; Kirichenko, Dmitri E; Dotsenko, Vladimir V; Miller, Robert; Webber, Robert J; Shevchenko, Pavel; Talalaevskii, Andrei; Gupta, Deepnarayan; Mukhanov, Oleg A [HYPRES, Inc., 175 Clearbrook Road, Elmsford, NY 10523 (United States)

    2007-11-15

    We have demonstrated a digital receiver performing direct digitization of radio-frequency signals over a wide frequency range from kilohertz to gigahertz. The complete system, consisting of a cryopackaged superconductor all-digital receiver (ADR) chip followed by room-temperature interface electronics and a field programmable gate array (FPGA) based post-processing module, has been developed. The ADR chip comprises a low-pass analog-to-digital converter (ADC) delta modulator with phase modulation-demodulation architecture together with digital in-phase and quadrature mixer and a pair of digital decimation filters. The chip is fabricated using a 4.5 kA cm{sup -2} process and is cryopackaged using a commercial-off-the-shelf cryocooler. Experimental results in HF, VHF, UHF and L bands and their analysis, proving consistent operation of the cryopackaged ADR chip up to 24.32 GHz clock frequency, are presented and discussed.

  7. Radio frequency identification--an innovative solution to guide dexterous prosthetic hands.

    Science.gov (United States)

    Trachtenberg, Matthew S; Singhal, Girish; Kaliki, Rahul; Smith, Ryan J; Thakor, Nitish V

    2011-01-01

    Dexterous manipulation of a multi-fingered prosthetic hand requires far more cognitive effort compared to typical 1 degree of freedom hands, which hinders their acceptance clinically. This paper presents a Myoelectrically-Operated Radio Frequency Identification (RFID) Prosthetic Hand (MORPH); an implementation of RFID with a myoelectric prosthetic hand as a means to amplify the controllable degrees of freedom. Contextual information from an object equipped with an RFID tag allows automatic preshaping along with dexterous control in an attempt to reduce the cognitive effort required to operate the terminal device. The myoelectric-RFID hybrid has been demonstrated in a proof-of-concept case study where an amputee was fitted with the device and subjected to activities adapted from the Jebsen Hand Function Test and the Smith Hand Function Evaluation with RFID-tagged and untagged items. Evaluation tests revealed that the MORPH system performed significantly better in 4 of the 8 tasks, and comparable to the control in the remainder.

  8. Upgrade of the radio frequency quadrupole cooler and buncher for the HIE-ISOLDE project

    CERN Document Server

    Babcock, Carla

    2013-01-01

    The upgrade to the ISOLDE facility, HIE-ISOLDE, will include an upgrade to the RFQCB (radio frequency quadrupole cooler and buncher), the focus of which will be fixing the problems of alignment with the current machine, improving the integrity of the vacuum system, stabilizing the internal gas pressure, and the changes associated with a new position. The beam passage inside the RFQCB has been simulated with an independent code to highlight the importance of the internal gas pressure, to motivate design changes in the new RFQCB and to explain ways to improve the performance of the current machine. The suspected misalignment of ISCOOL has been quantified, and, using a simulation of ions passing through the external injection electrodes, the effect of the misalignment on machine acceptance has been detailed. Plans for the future RFQCB test stand and HIE-ISOLDE installation have been outlined. (C) 2013 Elsevier B.V. All rights reserved.

  9. Effect of radio frequency waves of electromagnetic field on the tubulin.

    Science.gov (United States)

    Taghi, Mousavi; Gholamhosein, Riazi; Saeed, Rezayi-Zarchi

    2013-09-01

    Microtubules (MTs) are macromolecular structures consisting of tubulin heterodimers and present in almost every eukaryotic cell. MTs fulfill all conditions for generation of electromagnetic field and are electrically polar due to the electrical polarity of a tubulin heterodimer. The calculated static electric dipole moment of about 1000 Debye makes them capable of being aligned parallel to the applied electromagnetic field direction. In the present study, the tubulin heterodimers were extracted and purified from the rat brains. MTs were obtained by polymerization in vitro. Samples of microtubules were adsorbed in the absence and in the presence of electromagnetic fields with radio frequency of 900 Hz. Our results demonstrate the effect of electromagnetic field with 900 Hz frequency to change the structure of MTs. In this paper, a related patent was used that will help to better understand the studied subject.

  10. Review of Radio Frequency Identification and Wireless Technology for Structural Health Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Dhital, Dipesh; Chia, Chen Ciang; Lee, Jung Ryul [Chonbuk National University, Jeonju (Korea, Republic of); Park, Chan Yik [Aeronautical Technology Directorate, Agency for Defense Development, Daejeon (Korea, Republic of)

    2010-06-15

    Radio frequency identification(RFID) combined with wireless technology has good potential for structural health monitoring(SHM). We describe several advantages of RFID and wireless technologies for SHM, and review SHM examples with working principles, design and technical details for damage detection, heat exposure monitoring, force/strain sensing, and corrosion detection in concrete, steel, carbon fiber reinforced polymer(CFRP), and other materials. Various sensors combined with wireless communication are also discussed. These methodologies can be readily developed, implemented, and customized. There are some technical difficulties, but solutions are being addressed. Lastly, a surface acoustic wave-based RFID system is presented, and possible future trends of SHM based on RFID and wireless technology are presented

  11. Physics-based parametrization of the surface impedance for radio frequency sheaths

    Science.gov (United States)

    Myra, J. R.

    2017-07-01

    The properties of sheaths near conducting surfaces are studied for the case where both magnetized plasma and intense radio frequency (rf) waves coexist. The work is motivated primarily by the need to understand, predict, and control ion cyclotron range of frequency (ICRF) interactions with tokamak scrape-off layer plasmas and is expected to be useful in modeling rf sheath interactions in global ICRF codes. Employing a previously developed model for oblique angle magnetized rf sheaths [J. R. Myra and D. A. D'Ippolito, Phys. Plasmas 22, 062507 (2015)], an investigation of the four-dimensional parameter space governing these sheath is carried out. By combining numerical and analytical results, a parametrization of the surface impedance and voltage rectification for rf sheaths in the entire four-dimensional space is obtained.

  12. Radio Frequency Sensing of Particulate Matter Accumulation on a Gasoline Particulate Filter

    Energy Technology Data Exchange (ETDEWEB)

    Parks, II, James E [ORNL; Prikhodko, Vitaly Y [ORNL; Sappok, Alex [Filter Sensing Technologies; Ragaller, Paul [Filter Sensing Technologies; Bromberg, L. [Massachusetts Institute of Technology (MIT)

    2016-10-30

    Filter Sensing Technology’s radio frequency (RF) sensor for particulate filter on-board diagnostics (OBD) was studied on a lean gasoline engine at the National Transportation Research Center (NTRC) at Oak Ridge National Laboratory (ORNL). The response of the RF sensor to particulate matter (PM) or “soot” accumulation on the gasoline particulate filter (GPF) installed in the engine exhaust was evaluated. In addition, end plugs of the GPF were purposely removed, and subsequent changes to the RF sensor measured soot loading on the GPF were characterized. Results from the study showed that the RF sensor can accurately measure soot accumulation on a GPF; furthermore, the predicted decreased soot accumulation due to plug removal was detected by the RF sensor. Overall, the studies were short and preliminary in nature; however, clearly, the RF sensor demonstrated the capability of measuring GPF soot loading at a level suitable for use in lean gasoline engine emission control OBD and control.

  13. Global model for active control of capacitive radio frequency magnetron discharges

    Science.gov (United States)

    Engel, Dennis; Krueger, Dennis; Woelfel, Christian; Oberberg, Moritz; Lunze, Jan; Awakowicz, Peter; Brinkmann, Ralf Peter

    2016-09-01

    Sputtering technologies have a widespread of applications in modern industries. Up to now, no appropriate model is available for active control of these processes. Controlling inhibits the drift of process parameters and therefore helps to improve the quality of deposited thin films. The aim of this work is to develop a global model for radio frequency capacitively coupled plasma (RF-CCP) magnetron discharges. Several global models for RF-CCPs have been proposed, but most of them neglect the existence of a magnetic field inside the plasma. This work builds on existing models but takes into account the underlying magnetic field. Therefore a lumped circuit model with its corresponding system of differential equations is formulated and the influence of the magnetic field is analysed. The proposed model is used to investigate several parameters such as neutral gas pressure, magnetic field strength or applied voltage, to be able to actively control thin film growth.

  14. Simultaneous frequency upconversion and phase coding of a radio-frequency signal for photonic radars.

    Science.gov (United States)

    Zhu, Sha; Shi, Zhan; Li, Ming; Zhu, Ning Hua; Li, Wei

    2018-02-01

    We report a photonic approach to simultaneously realize frequency upconversion and phase coding of a radio-frequency (RF) signal based on polarization manipulation of optical signals. An intermediate frequency (IF) signal is upconverted to the local frequency (LO) band using a dual-polarization dual-parallel Mach-Zehnder modulator, while a high-speed polarization modulator is used to realize high-speed phase coding of the upconverted signal. The key advantage of the proposed method is that no optical or electrical filters are required to remove the residual IF, LO, and undesired downconverted signals, which ensures a broad operation bandwidth, excellent isolation, and wide tunability. The proposed scheme is theoretically analyzed and experimentally verified.

  15. The Interaction of Radio-Frequency Fields With Dielectric Materials at Macroscopic to Mesoscopic Scales

    Science.gov (United States)

    Baker-Jarvis, James; Kim, Sung

    2012-01-01

    The goal of this paper is to overview radio-frequency (RF) electromagnetic interactions with solid and liquid materials from the macroscale to the nanoscale. The overview is geared toward the general researcher. Because this area of research is vast, this paper concentrates on currently active research areas in the megahertz (MHz) through gigahertz (GHz) frequencies, and concentrates on dielectric response. The paper studies interaction mechanisms both from phenomenological and fundamental viewpoints. Relaxation, resonance, interface phenomena, plasmons, the concepts of permittivity and permeability, and relaxation times are summarized. Topics of current research interest, such as negative-index behavior, noise, plasmonic behavior, RF heating, nanoscale materials, wave cloaking, polaritonic surface waves, biomaterials, and other topics are overviewed. Relaxation, resonance, and related relaxation times are overviewed. The wavelength and material length scales required to define permittivity in materials is discussed. PMID:26900513

  16. 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.

  17. Pulsed laser deposition of yttrium photocathode suitable for use in radio-frequency guns

    Science.gov (United States)

    Lorusso, A.; Trovò, M.; Demidovich, A.; Cinquegrana, P.; Gontad, F.; Broitman, E.; Chiadroni, E.; Perrone, A.

    2017-12-01

    Yttrium (Y) thin film was grown by pulsed laser deposition (PLD) on a copper (Cu) polycrystalline substrate. Ex situ morphological and structural characterisations of the circular Y film of 1.2 µm thickness and 3 mm diameter have shown a very low droplet density on the film surface and a crystalline feature with a preferred orientation along the Y (100) plane. Moreover, Y thin film resulted in being very adherent to the Cu substrate and more scratch resistant than Cu bulk. A twin thin film was deposited also on a Cu backflange of a radio-frequency (RF) gun to test the suitability of the metallic thin film as photocathode. It was observed that the Y-coated photocathode was characterised by a quantum efficiency ( QE) higher than that of the Cu bulk photocathode even if the presence of space charge effects didn't allow deriving the absolute maximum value of QE of Y photocathode.

  18. Magnesium diboride on inner wall of copper tube: A test case for superconducting radio frequency cavities

    Science.gov (United States)

    Withanage, Wenura K.; Lee, N. H.; Penmatsa, Sashank V.; Wolak, M. A.; Nassiri, A.; Xi, X. X.

    2017-10-01

    Superconductor magnesium diboride is considered one of the viable materials to substitute bulk niobium for superconducting radio frequency cavities. Utilizing a MgB2 coating on the inner wall of a copper cavity will allow operation at higher temperatures (20-25 K) than Nb cavities due to the high transition temperature of MgB2 (39 K) and the high thermal conductivity of Cu. In this paper, we present results of MgB2 coating on Cu tubes with similar dimensions to a 3 GHz cavity, as the first step towards coating the actual cavity, using the hybrid physical chemical vapor deposition technique. The results show successful coating of a uniform MgB2 layer on the inner wall of the Cu tubes with Tc as high as 37 K.

  19. 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.

  20. Radio-frequency oxygen-plasma-enhanced pulsed laser deposition of IGZO films

    Directory of Open Access Journals (Sweden)

    Chia-Man Chou

    2017-07-01

    Full Text Available We demonstrate the crystalline structures, optical transmittance, surface and cross-sectional morphologies, chemical compositions, and electrical properties of indium gallium zinc oxide (IGZO-based thin films deposited on glass and silicon substrates through pulsed laser deposition (PLD incorporated with radio-frequency (r.f.-generated oxygen plasma. The plasma-enhanced pulsed laser deposition (PEPLD-based IGZO thin films exhibited a c-axis-aligned crystalline (CAAC structure, which was attributed to the increase in Zn-O under high oxygen vapor pressure (150 mTorr. High oxygen vapor pressure (150 mTorr and low r.f. power (10 W are the optimal deposition conditions for fabricating IGZO thin films with improved electrical properties.

  1. Magnesium diboride on inner wall of copper tube: A test case for superconducting radio frequency cavities

    Directory of Open Access Journals (Sweden)

    Wenura K. Withanage

    2017-10-01

    Full Text Available Superconductor magnesium diboride is considered one of the viable materials to substitute bulk niobium for superconducting radio frequency cavities. Utilizing a MgB_{2} coating on the inner wall of a copper cavity will allow operation at higher temperatures (20–25 K than Nb cavities due to the high transition temperature of MgB_{2} (39 K and the high thermal conductivity of Cu. In this paper, we present results of MgB_{2} coating on Cu tubes with similar dimensions to a 3 GHz cavity, as the first step towards coating the actual cavity, using the hybrid physical chemical vapor deposition technique. The results show successful coating of a uniform MgB_{2} layer on the inner wall of the Cu tubes with T_{c} as high as 37 K.

  2. 3D Acoustic Modes, Shot Noise and Strain Displacements in a Radio Frequency Quantum Point Contact

    Science.gov (United States)

    Stettenheim, J.; Thalakulam, M.; Pan, F.; Bal, M.; Pfeiffer, L. N.; West, K. W.; Rimberg, A. J.

    2009-03-01

    As previously reported, our broadband frequency resolved measurements of shot noise in a radio frequency QPC (RF-QPC) reveal a remarkable frequency dependence absent from theoretical predictions. Based on piezoelectric coupling in GaAs, our data suggest a feedback loop in which shot noise drives resonant acoustic vibrations that in turn create correlations in electron tunneling. The feedback concentrates the initially white noise in a narrow band around the sample's resonant frequency, allowing shot noise spectrum engineering. We solve for the 3D acoustic modes of our samples, finding close correspondence with measured frequencies. We have determined that the geometry and magnitude of the polarization field selects the acoustic mode excited. As polarization fields and strain displacements are linked in GaAs, we estimate the ultimate mechanical displacement sensitivity of our RF-QPC.

  3. Flux pinning characteristics in cylindrical ingot niobium used in superconducting radio frequency cavity fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Dhavale Ashavai, Pashupati Dhakal, Anatolii A Polyanskii, Gianluigi Ciovati

    2012-04-01

    We present the results of from DC magnetization and penetration depth measurements of cylindrical bulk large-grain (LG) and fine-grain (FG) niobium samples used for the fabrication of superconducting radio frequency (SRF) cavities. The surface treatment consisted of electropolishing and low temperature baking as they are typically applied to SRF cavities. The magnetization data were fitted using a modified critical state model. The critical current density Jc and pinning force Fp are calculated from the magnetization data and their temperature dependence and field dependence are presented. The LG samples have lower critical current density and pinning force density compared to FG samples which implies a lower flux trapping efficiency. This effect may explain the lower values of residual resistance often observed in LG cavities than FG cavities.

  4. Laser polishing of niobium for superconducting radio-frequency accelerator applications

    Directory of Open Access Journals (Sweden)

    Liang Zhao

    2014-08-01

    Full Text Available Interior surfaces of niobium cavities used in superconducting radio frequency accelerators are now obtained by buffered chemical polish and/or electropolish. Laser polishing is a potential alternative, having advantages of speed, freedom from noxious chemistry and availability of in-process inspection. We studied the influence of the laser power density and laser beam raster rate on the surface topography. These two factors need to be combined carefully to smooth the surface without damage. Computational modeling was used to estimate the surface temperature and gain insight into the mechanism of laser polishing. Power spectral density analysis of surface topography measurements shows that laser polishing can produce smooth topography similar to that obtained by electropolish. This is a necessary first step toward introducing laser polishing as an alternative to the currently practiced chemical polishing.

  5. Implantation of radio frequency identification device (RFID) microchip in disaster victim identification (DVI).

    Science.gov (United States)

    Meyer, Harald J; Chansue, Nantarika; Monticelli, Fabio

    2006-03-10

    The tsunami catastrophe of December 2004 left more than 200,000 dead. Disaster victim identification (DVI) teams were presented with the unprecedented challenge of identifying thousands of mostly markedly putrefied and partially skeletised bodies. To this end, an adequate body tagging method is essential. Conventional body bag tagging in terms of writing on body bags and placing of tags inside body bags proved unsatisfactory and problem prone due to consequences of cold storage, formalin (formaldehyde) embalming and body numbers inside storage facilities. The placement of radio frequency identification device (RFID) microchips inside victim bodies provided a practical solution to problems of body tagging and attribution in the DVI setting encountered by the Austrian DVI team in Thailand in early 2005.

  6. Radio Frequency Compatibility of an RFID Tag on Glideslope Navigation Receivers

    Science.gov (United States)

    Nguyen, Truong X.; Mielnik, John J.

    2008-01-01

    A process is demonstrated to show compatibility between a radio frequency identification (RFID) tag and an aircraft glideslope (GS) radio receiver. The particular tag chosen was previously shown to have significant peak spurious emission levels that far exceeded the emission limits in the GS aeronautical band. The spurious emissions are emulated in the study by capturing the RFID fundamental transmission and playing back the signal in the GS band. The signal capturing and playback are achieved with a vector signal generator and a spectrum analyzer that can output the in-phase and quadrature components (IQ). The simulated interference signal is combined with a desired GS signal before being injected into a GS receiver s antenna port for interference threshold determination. Minimum desired propagation loss values to avoid interference are then computed and compared against actual propagation losses for several aircraft.

  7. Fast shut-down protection system for radio frequency breakdown and multipactor testing

    Science.gov (United States)

    Graves, T. P.; Hanson, P.; Michaelson, J. M.; Farkas, A. D.; Hubble, A. A.

    2014-02-01

    Radio frequency (RF) breakdown such as multipactor or ionization breakdown is a device-limiting phenomenon for on-orbit spacecraft used for communication, navigation, or other RF payloads. Ground testing is therefore part of the qualification process for all high power components used in these space systems. This paper illustrates a shut-down protection system to be incorporated into multipactor/ionization breakdown ground testing for susceptible RF devices. This 8 channel system allows simultaneous use of different diagnostic classes and different noise floors. With initiation of a breakdown event, diagnostic signals increase above a user-specified level, which then opens an RF switch to eliminate RF power from the high power amplifier. Examples of this system in use are shown for a typical setup, illustrating the reproducibility of breakdown threshold voltages and the lack of multipactor conditioning. This system can also be utilized to prevent excessive damage to RF components in tests with sensitive or flight hardware.

  8. Improvement of technical purpose materials performance characteristics with the radio frequency low pressure plasma

    Science.gov (United States)

    Makhotkina, L. Yu; Khristoliubova, V. I.

    2017-11-01

    The main aim of the work is to solve the actual problem of increasing the competitiveness of tanning products by reducing the prime cost and improving the quality of finished products due to the increased durability of the working elements of tanneries. The impact of the low pressure radio frequency (RF) plasma in the processes of treating for modification of the materials for special purposes is considered in the article. The results of working elements of tanneries and the materials for special purposes sample processing by a RF low pressure plasma are described. As a result of leather materials nano structuring and nano modifying physical, mechanical and hygienic characteristics were increased. Processing of the technical purpose materials allows to increase operational performance of products and extend their lifespan.

  9. Blood-brain barrier disruption by continuous-wave radio frequency radiation.

    Science.gov (United States)

    Sirav, Bahriye; Seyhan, Nesrin

    2009-01-01

    The increasing use of cellular phones and the increasing number of associated base stations are becoming a widespread source of non ionizing electromagnetic radiation. Some biological effects are likely to occur even at low-level EM fields. This study was designed to investigate the effects of 900 and 1,800 MHz Continuous Wave Radio Frequency Radiation (CW RFR) on the permeability of Blood Brain Barrier (BBB) of rats. Results have shown that 20 min RFR exposure of 900 and 1,800 MHz induces an effect and increases the permeability of BBB of male rats. There was no change in female rats. The scientific evidence on RFR safety or harm remains inconclusive. More studies are needed to demonstrate the effects of RFR on the permeability of BBB and the mechanisms of that breakdown.

  10. Electric field and radio frequency measurements for rocket engine health monitoring applications

    Science.gov (United States)

    Valenti, Elizabeth L.

    1992-01-01

    Electric-field (EF) and radio-frequency (RF) emissions generated in the exhaust plumes of the diagnostic testbed facility thruster (DTFT) and the SSME are examined briefly for potential applications to plume diagnostics and engine health monitoring. Hypothetically, anomalous engine conditions could produce measurable changes in any characteristic EF and RF spectral signatures identifiable with a 'healthly' plumes. Tests to determine the presence of EF and RF emissions in the DTFT and SSME exhaust plumes were conducted. EF and RF emissions were detected using state-of-the-art sensors. Analysis of limited data sets show some apparent consistencies in spectral signatures. Significant emissions increases were detected during controlled tests using dopants injected into the DTFT.

  11. Radio frequency identification (RFID) in health care: privacy and security concerns limiting adoption.

    Science.gov (United States)

    Rosenbaum, Benjamin P

    2014-03-01

    Radio frequency identification (RFID) technology has been implemented in a wide variety of industries. Health care is no exception. This article explores implementations and limitations of RFID in several health care domains: authentication, medication safety, patient tracking, and blood transfusion medicine. Each domain has seen increasing utilization of unique applications of RFID technology. Given the importance of protecting patient and data privacy, potential privacy and security concerns in each domain are discussed. Such concerns, some of which are inherent to existing RFID hardware and software technology, may limit ubiquitous adoption. In addition, an apparent lack of security standards within the RFID domain and specifically health care may also hinder the growth and utility of RFID within health care for the foreseeable future. Safeguarding the privacy of patient data may be the most important obstacle to overcome to allow the health care industry to take advantage of the numerous benefits RFID technology affords.

  12. Rule Based System for Medicine Inventory Control Using Radio Frequency Identification (RFID

    Directory of Open Access Journals (Sweden)

    Ardhyanti Mita Nugraha Joanna

    2018-01-01

    Full Text Available Rule based system is very efficient to ensure stock of drug to remain available by utilizing Radio Frequency Identification (RFID as input means automatically. This method can ensure the stock of drugs to remain available by analyzing the needs of drug users. The research data was the amount of drug usage in hospital for 1 year. The data was processed by using ABC classification to determine the drug with fast, medium and slow movement. In each classification result, rule based algorithm was given for determination of safety stock and Reorder Point (ROP. This research yielded safety stock and ROP values that vary depending on the class of each drug. Validation is done by comparing the calculation of safety stock and reorder point both manually and by system, then, it was found that the mean deviation value at safety stock was 0,03 and and ROP was 0,08.

  13. Multianalyte chemical identification and quantitation using a single radio frequency identification sensor.

    Science.gov (United States)

    Potyrailo, Radislav A; Morris, William G

    2007-01-01

    We demonstrate an approach for multianalyte chemical identification and quantitation using a single conventional radio frequency identification (RFID) tag that has been adapted for chemical sensing. Unlike other approaches of using RFID sensors, where a special tag should be designed at a much higher cost, we utilize a conventional RFID tag and coat it with a chemically sensitive film. As an example, we demonstrate detection of several vapors of industrial, health, law enforcement, and security interest (ethanol, methanol, acetonitrile, water vapors) with a single 13.56-MHz RFID tag coated with a solid polymer electrolyte sensing film. By measuring simultaneously several parameters of the complex impedance from such an RFID sensor and applying multivariate statistical analysis methods, we were able to identify and quantify several vapors of interest. With a careful selection of the sensing film and measurement conditions, we achieved parts-per-billion vapor detection limits in air. These RFID sensors are very attractive as ubiquitous multianalyte distributed sensor networks.

  14. Compound Semiconductor Devices for Low-Power High-Efficiency Radio Frequency Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Baca, A.G.; Chang, P.C.; Hietala, V.M.; Sloan, L.R.

    1999-02-18

    The power consumption of Radio Frequency (RF) electronics is a significant issue for Wireless systems. Since most wireless systems are portable and thus battery operated, reductions in DC power consumption can significantly reduce the weight and/or increase the battery lifetime of the system. As transmission consumes significantly more power than reception for most Wireless applications, previous efforts have been focused on increasing the efficiency of RF power amplification. These efforts have resulted in large increases in transmit efficiencies with research-grade amplifier efficiencies approaching 100%. In this paper, they describe their efforts on reducing power consumption of reception and other small signal RF functions. Additionally, recent power efficiency measurements on InP HEMT devices for transmission are presented. This work focuses on the needs of today's typical portable Wireless systems, which operate at frequencies up to several GHz.

  15. Piezoelectric coefficient of InN films prepared by radio-frequency sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wintrebert-Fouquet, M. [Physics Department, Macquarie University, North Ryde NSW 2109 (Australia)], E-mail: mariew@ics.mq.edu.au; Butcher, K.S.A.; Guy, I.L.; Zheng, Z. [Physics Department, Macquarie University, North Ryde NSW 2109 (Australia)

    2008-09-01

    An interferometric method has been used to measure the piezoelectric coefficient d{sub 33} in indium nitride films deposited by radio-frequency sputtering on borosilicate glass coated with gold. This low temperature growth technique has the advantage of being able to produce samples for piezoelectric measurements where the InN film is grown directly on an Au metal back contact, allowing the accurate measurement of the piezoelectric coefficient of the InN layer without any parasitic series resistance. The InN growth conditions are described, and both crystal and optical characterizations of the film are presented. The measured value of the coefficient was found to be 4.0 {+-} 0.1 pm V{sup -1}.

  16. Effect of laser intensity on radio frequency emissions from laser induced breakdown of atmospheric air

    Energy Technology Data Exchange (ETDEWEB)

    Vinoth Kumar, L.; Manikanta, E.; Leela, Ch.; Prem Kiran, P., E-mail: premkiranuoh@gmail.com, E-mail: prem@uohyd.ac.in [Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad 500046 (India)

    2016-06-07

    The studies on the effect of input laser intensity, through the variation of laser focusing geometry, on radio frequency (RF) emissions, over 30–1000 MHz from nanosecond (ns) and picosecond (ps) laser induced breakdown (LIB) of atmospheric air are presented. The RF emissions from the ns and ps LIB were observed to be decreasing and increasing, respectively, when traversed from tight to loose focusing conditions. The angular and radial intensities of the RF emissions from the ns and ps LIB are found to be consistent with sin{sup 2}θ/r{sup 2} dependence of the electric dipole radiation. The normalized RF emissions were observed to vary with incident laser intensity (Iλ{sup 2}), indicating the increase in the induced dipole moment at moderate input laser intensities and the damping of radiation due to higher recombination rate of plasma at higher input laser intensities.

  17. 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.

  18. Detection of Linear Polarization from SNR Cassiopeia A at Low Radio Frequencies

    Science.gov (United States)

    Raja, Wasim; Deshpande, Avinash A.

    2015-03-01

    We report detection of the weak but significant linear polarization from the Supernova Remnant Cas A at low radio frequencies (327 MHz) using the GMRT. The spectro-polarimetric data (16 MHz bandwidth with 256 spectral channels) was analyzed using the technique of Faraday Tomography. Ascertaining association of this weak polarization to the source is non-trivial in the presence of the remnant instrumental polarization (constant, and establish the anti-correlation as well as the correspondence of this correlation with the mean X-ray profile (Figure 1). Given the angular and RM-resolution in our data, the observed depolarization relative to that at higher frequencies, implies that the mixing of thermal and non-thermal plasma within the source might be occurring on spatial scales ~ 1000 AU, assuming random superposition of polarization states.

  19. Sn-doped β-Ga2O3 nanowires deposited by radio frequency powder sputtering

    Science.gov (United States)

    Lee, Su Yong; Kang, Hyon Chol

    2018-01-01

    We report the synthesis and characterization of Sn-doped β-Ga2O3 nanowires (NWs) deposited using radio frequency powder sputtering. The growth sequence of Sn-doped β-Ga2O3 NWs is similar to that of the undoped β-Ga2O3 NWs. Self-assembled Ga clusters act as seeds for initiating the growth of Sn-doped β-Ga2O3 NWs through a vapor–liquid–solid process, while Sn atoms are incorporated into the trunk of NWs uniformly. Different from the straight shape of undoped NWs, the conical shape of NWs is observed, which is attributed to the change in supersaturation conditions and the diffusion of the catalyst tip and reaction species.

  20. A Novel L-Shape Ultra Wideband Chipless Radio-Frequency Identification Tag

    Directory of Open Access Journals (Sweden)

    Khaled Issa

    2017-01-01

    Full Text Available A novel compact dual-polarized-spectral-signature-based chipless radio-frequency identification (RFID tag is presented. Specifically, an L-shape resonator-based structure is optimized to have different spectral signatures in both horizontal and vertical polarizations, in order to double the encoding capacity. Resonators’ slot width and the space between closely placed resonators are also optimized to enhance the mutual coupling, thereby helping in achieving high-data encoding density. The proposed RFID tag operates over 5 GHz to 10 GHz frequency band. As a proof of concept, three different 18-bit dual-polarized RFID tags are simulated, fabricated, and tested in an anechoic chamber environment. The measurement data show reasonable agreement with the simulation results, with respect to resonators’ frequency positions, null depth, and their bandwidth over the operational spectrum.

  1. 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.

  2. Exposure to radio-frequency electromagnetic fields and behavioural problems in Bavarian children and adolescents.

    Science.gov (United States)

    Thomas, Silke; Heinrich, Sabine; von Kries, Rüdiger; Radon, Katja

    2010-02-01

    Only few studies have so far investigated possible health effects of radio-frequency electromagnetic fields (RF EMF) in children and adolescents, although experts discuss a potential higher vulnerability to such fields. We aimed to investigate a possible association between measured exposure to RF EMF fields and behavioural problems in children and adolescents. 1,498 children and 1,524 adolescents were randomly selected from the population registries of four Bavarian (South of Germany) cities. During an Interview data on participants' mental health, socio-demographic characteristics and potential confounders were collected. Mental health behaviour was assessed using the German version of the Strengths and Difficulties Questionnaire (SDQ). Using a personal dosimeter, we obtained radio-frequency EMF exposure profiles over 24 h. Exposure levels over waking hours were expressed as mean percentage of the reference level. Overall, exposure to radiofrequency electromagnetic fields was far below the reference level. Seven percent of the children and 5% of the adolescents showed an abnormal mental behaviour. In the multiple logistic regression analyses measured exposure to RF fields in the highest quartile was associated to overall behavioural problems for adolescents (OR 2.2; 95% CI 1.1-4.5) but not for children (1.3; 0.7-2.6). These results are mainly driven by one subscale, as the results showed an association between exposure and conduct problems for adolescents (3.7; 1.6-8.4) and children (2.9; 1.4-5.9). As this is one of the first studies that investigated an association between exposure to mobile telecommunication networks and mental health behaviour more studies using personal dosimetry are warranted to confirm these findings.

  3. Development and beam test of a continuous wave radio frequency quadrupole accelerator

    Science.gov (United States)

    Ostroumov, P. N.; Mustapha, B.; Barcikowski, A.; Dickerson, C.; Kolomiets, A. A.; Kondrashev, S. A.; Luo, Y.; Paskvan, D.; Perry, A.; Schrage, D.; Sharamentov, S. I.; Sommer, R.; Toter, W.; Zinkann, G.

    2012-11-01

    The front end of any modern ion accelerator includes a radio frequency quadrupole (RFQ). While many pulsed ion linacs successfully operate RFQs, several ion accelerators worldwide have significant difficulties operating continuous wave (CW) RFQs to design specifications. In this paper we describe the development and results of the beam commissioning of a CW RFQ designed and built for the National User Facility: Argonne Tandem Linac Accelerator System (ATLAS). Several innovative ideas were implemented in this CW RFQ. By selecting a multisegment split-coaxial structure, we reached moderate transverse dimensions for a 60.625-MHz resonator and provided a highly stabilized electromagnetic field distribution. The accelerating section of the RFQ occupies approximately 50% of the total length and is based on a trapezoidal vane tip modulation that increased the resonator shunt impedance by 60% in this section as compared to conventional sinusoidal modulation. To form an axially symmetric beam exiting the RFQ, a very short output radial matcher with a length of 0.75βλ was developed. The RFQ is designed as a 100% oxygen-free electronic (OFE) copper structure and fabricated with a two-step furnace brazing process. The radio frequency (rf) measurements show excellent rf properties for the resonator, with a measured intrinsic Q equal to 94% of the simulated value for OFE copper. An O5+ ion beam extracted from an electron cyclotron resonance ion source was used for the RFQ commissioning. In off-line beam testing, we found excellent coincidence of the measured beam parameters with the results of beam dynamics simulations performed using the beam dynamics code TRACK, which was developed at Argonne. These results demonstrate the great success of the RFQ design and fabrication technology developed here, which can be applied to future CW RFQs.

  4. Magneto-optical properties of yttrium iron garnet (YIG) thin films elaborated by radio frequency sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Boudiar, T. [DIOM Laboratory, Faculty des Sciences, 23 rue du Docteur Paul Michelon, 42023 Saint-Etienne (France)]. E-mail: toufik.boudiar@univ-st-etienne.fr; Payet-Gervy, B. [DIOM Laboratory, Faculty des Sciences, 23 rue du Docteur Paul Michelon, 42023 Saint-Etienne (France); Blanc-Mignon, M.-F. [DIOM Laboratory, Faculty des Sciences, 23 rue du Docteur Paul Michelon, 42023 Saint-Etienne (France); Rousseau, J.-J. [DIOM Laboratory, Faculty des Sciences, 23 rue du Docteur Paul Michelon, 42023 Saint-Etienne (France); Le Berre, M. [LPM, UMR 5511, INSA Lyon, 7 av. Jean Capelle, 69621 Villeurbanne (France); Joisten, H. [CEA-LETI, 17 rue des martyrs, 38041 Grenoble (France)

    2004-12-01

    Thin films of yttrium iron garnet (YIG) are grown by radio frequency magnetron non reactive sputtering system. Thin films are crystallised by heat-treatment to obtain magneto-optical properties. On quartz substrate, the network of cracks observed on the annealed samples can be explained by the difference between the thermal expansion coefficient of substrate and YIG. Physico-chemical analysis shown that the obtained material has a correct stoichiometry and is crystallised as FCC. The Faraday rotation of thin films is measured with a classical ellipsometric system based on transmission which allows us to obtained an accuracy of 0.01 deg. The variation of Faraday rotation is studied on the one hand versus radio frequency power applied to the cathode during the deposition and on the other hand versus the applied magnetic field. The results are compared with those obtained by vibrating sample magnetometer analysis in perpendicular configuration. A maximum Faraday rotation is observed to be 1900 deg./cm at the wavelength of 594nm for a YIG thin film formed on quartz substrate and annealed at 740 deg. C. The values of the Faraday rotation coefficients obtained in the study versus the wavelength are comparable to those of the literature for the bulk material. In order to eliminate the stress due to the heat-treatment, we made some films on single crystals of gadolinium gallium garnet (111) substrates for which thermal expansion coefficient is near than the YIG one. The material crystallises with no crackles and the Faraday effect is equivalent.

  5. The Breakthrough Listen Search for Intelligent Life: Radio Frequency Interference in the Green Bank Telescope

    Science.gov (United States)

    Dana, Ryan

    2018-01-01

    In the search for extra terrestrial intelligence, the vast majority of our “signals of interest,” are simply satellite radio frequency interference. The goal to my research, therefore, was to accurately predict the exact locations of satellites in our sky to analyze specific satellites causing the interference as well as potentially predict when satellites will cross in the way of our beams so that we can further optimize our scripts and get more usable data.I have built an algorithm that plots the exact location in altitude and azimuth of any grouping of satellites that you want in the sky from any position on earth in latitude, longitude, and elevation. From there, you can input a specific right ascension and declination of the location you are trying to track in the sky with a telescope. Using these inputs, we can calculate the angular and positional distance of certain satellites to our beam to further analyze satellite radio frequency interference.The process begins by importing a list of Two Line Element information that the algorithm reads in. Two Line Elements are how Satellites are organized and are updated frequently. They give a variety of information ranging from the Satellite ID to its Mean Motion or anomaly. From there, the code breaks up the information given by these elements to predict their location. The algorithm can also plot in 3D coordinates around an earthlike sphere to conceptualize the route that each Satellite has taken.The code has been used in a variety of ways but most notably to identify satellites interfering with the beam for Arecibo’s Ross 128 Candidate signal. From here, the code will be the backbone to calculating drift rates, Doppler shifts and intensity of certain satellites and why our team consistently receives estranged satellite signals of interest. Furthermore, in the case of a serious candidate signal in the near future, it will be important to analyze satellites interfering in the beam.

  6. The effects of radio-frequency electromagnetic fields on T cell function during development.

    Science.gov (United States)

    Ohtani, Shin; Ushiyama, Akira; Maeda, Machiko; Ogasawara, Yuki; Wang, Jianqing; Kunugita, Naoki; Ishii, Kazuyuki

    2015-05-01

    With the widespread use of radio-frequency devices, it is increasingly important to understand the biological effects of the associated electromagnetic fields. Thus, we investigated the effects of radio-frequency electromagnetic fields (RF-EMF) on T cell responses during development due to the lack of science-based evidence for RF-EMF effects on developmental immune systems. Sprague Dawley (SD) rats were exposed to 2.14-GHz wideband code division multiple-access (W-CDMA) RF signals at a whole-body specific absorption rate (SAR) of 0.2 W/kg. Exposures were performed for a total of 9 weeks spanning in utero development, lactation and the juvenile period. Rats were continuously exposed to RF-EMF for 20 h/day, 7 days/week. Comparisons of control and exposed rats using flow cytometry revealed no changes in the numbers of CD4/CD8 T cells, activated T cells or regulatory T cells among peripheral blood cells, splenocytes and thymocytes. Expression levels of 16 genes that regulate the immunological Th1/Th2 paradigm were analyzed using real-time PCR in the spleen and thymus tissues of control and RF-EMF-exposed rats. Although only the Il5 gene was significantly regulated in spleen tissues, Il4, Il5 and Il23a genes were significantly upregulated in thymus tissues following exposure to RF-EMF. However, ELISAs showed no changes in serum IL-4 protein concentrations. These data indicate no adverse effects of long-term RF-EMF exposure on immune-like T cell populations, T cell activation, or Th1/Th2 balance in developing rats, although significant transcriptional effects were observed. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  7. Development and beam test of a continuous wave radio frequency quadrupole accelerator

    Directory of Open Access Journals (Sweden)

    P. N. Ostroumov

    2012-11-01

    Full Text Available The front end of any modern ion accelerator includes a radio frequency quadrupole (RFQ. While many pulsed ion linacs successfully operate RFQs, several ion accelerators worldwide have significant difficulties operating continuous wave (CW RFQs to design specifications. In this paper we describe the development and results of the beam commissioning of a CW RFQ designed and built for the National User Facility: Argonne Tandem Linac Accelerator System (ATLAS. Several innovative ideas were implemented in this CW RFQ. By selecting a multisegment split-coaxial structure, we reached moderate transverse dimensions for a 60.625-MHz resonator and provided a highly stabilized electromagnetic field distribution. The accelerating section of the RFQ occupies approximately 50% of the total length and is based on a trapezoidal vane tip modulation that increased the resonator shunt impedance by 60% in this section as compared to conventional sinusoidal modulation. To form an axially symmetric beam exiting the RFQ, a very short output radial matcher with a length of 0.75βλ was developed. The RFQ is designed as a 100% oxygen-free electronic (OFE copper structure and fabricated with a two-step furnace brazing process. The radio frequency (rf measurements show excellent rf properties for the resonator, with a measured intrinsic Q equal to 94% of the simulated value for OFE copper. An O^{5+} ion beam extracted from an electron cyclotron resonance ion source was used for the RFQ commissioning. In off-line beam testing, we found excellent coincidence of the measured beam parameters with the results of beam dynamics simulations performed using the beam dynamics code TRACK, which was developed at Argonne. These results demonstrate the great success of the RFQ design and fabrication technology developed here, which can be applied to future CW RFQs.

  8. A comparison of conventional and radio frequency defrosting of lean beef meats: Effects on water binding characteristics.

    Science.gov (United States)

    Farag, K W; Duggan, E; Morgan, D J; Cronin, D A; Lyng, J G

    2009-10-01

    The effect of defrosting rate (slow conventional air vs. fast radio frequency (RF) method) on water holding properties of lean beef meat (whole, minced and comminuted) was investigated using a conventional centrifugation method (drip loss), nuclear magnetic resonance relaxometry (NMR) and dielectric spectroscopy. Tempering by radio frequency (RF) or a conventional air method had no subsequent effect (P⩾0.05) on drip loss. However, thawing by RF resulted in a significant decrease in drip loss (Pwater binding in meat following RF tempering/thawing.

  9. The Radio Frequency Environment at 240-270 MHz with Application to Signal-of-Opportunity Remote Sensing

    Science.gov (United States)

    Piepmeier, Jeffrey R.; Vega, Manuel; Fritts, Matthew; Du Toit, Cornelis; Knuble, Joseph; Lin, Yao-Cheng; Nold, Benjamin; Garrison, James

    2017-01-01

    Low frequency observations are desired for soil moisture and biomass remote sensing. Long wavelengths are needed to penetrate vegetation and Earths land surface. In addition to the technical challenges of developing Earth observing spaceflight instruments operating at low frequencies, the radio frequency spectrum allocated to remote sensing is limited. Signal-of-opportunity remote sensing offers the chance to use existing signals exploiting their allocated spectrum to make Earth science measurements. We have made observations of the radio frequency environment around 240-270 MHz and discuss properties of desired and undesired signals.

  10. Model of the Radio Frequency (RF) Excitation Response from Monopole and Dipole Antennas in a Large Scale Tank

    Science.gov (United States)

    Wilson, Jeffrey D.; Zimmerli, Gregory A.

    2012-01-01

    Good antenna-mode coupling is needed for determining the amount of propellant in a tank through the method of radio frequency mass gauging (RFMG). The antenna configuration and position in a tank are important factors in coupling the antenna to the natural electromagnetic modes. In this study, different monopole and dipole antenna mounting configurations and positions were modeled and responses simulated in a full-scale tank model with the transient solver of CST Microwave Studio (CST Computer Simulation Technology of America, Inc.). The study was undertaken to qualitatively understand the effect of antenna design and placement within a tank on the resulting radio frequency (RF) tank spectrum.

  11. Radio frequency phototube and optical clock: High resolution, high rate and highly stable single photon timing technique

    Energy Technology Data Exchange (ETDEWEB)

    Margaryan, Amur

    2011-10-01

    A new timing technique for single photons based on the radio frequency phototube and optical clock or femtosecond optical frequency comb generator is proposed. The technique has a 20 ps resolution for single photons, is capable of operating with MHz frequencies and achieving 10 fs instability level.

  12. Automatic DGD and GVD compensation at 640 Gb/s based on scalar radio-frequency spectrum measurement

    DEFF Research Database (Denmark)

    Paquot, Yvan; Schröder, Jochen; Palushani, Evarist

    2013-01-01

    of separate GVD and DGD compensators using an impairment monitor based on an integrated all-optical radio-frequency (RF) spectrum analyzer. We show that low-bandwidth measurement of only a single tone in the RF spectrum is sufficient for automatic compensation for multiple degrees of freedom using...

  13. Mathematical modeling of a radio-frequency path for IEEE 802.11ah based wireless sensor networks

    Science.gov (United States)

    Tyshchenko, Igor; Cherepanov, Alexander; Dmitrii, Vakhnin; Popova, Mariia

    2017-09-01

    This article discusses the process of creating the mathematical model of a radio-frequency path for an IEEE 802.11ah based wireless sensor networks using M atLab Simulink CAD tools. In addition, it describes occurring perturbing effects and determining the presence of a useful signal in the received mixture.

  14. Essays on the Effect of Radio Frequency Identification (RFID) on the Management of Healthcare Supply Chain Performance

    Science.gov (United States)

    Cakici, Ozden Engin

    2012-01-01

    This dissertation examines three issues on the effect of Radio Frequency Identification (RFID) on the management of healthcare supply chain performance within the context of inventory management. Motivated by a case study conducted in a radiology practice, the second chapter analyzes the incremental benefits of RFID over barcodes for managing…

  15. Exposure to radio frequency electromagnetic fields from wireless computer networks: duty factors of Wi-Fi devices operating in schools.

    Science.gov (United States)

    Khalid, M; Mee, T; Peyman, A; Addison, D; Calderon, C; Maslanyj, M; Mann, S

    2011-12-01

    The growing use of wireless local area networks (WLAN) in schools has prompted a study to investigate exposure to the radio frequency (RF) electromagnetic fields from Wi-Fi devices. International guidelines on limiting the adverse health effects of RF, such as those of ICNIRP, allow for time-averaging of exposure. Thus, as Wi-Fi signals consist of intermittent bursts of RF energy, it is important to consider the duty factors of devices in assessing the extent of exposure and compliance with guidelines. Using radio packet capture methods, the duty factor of Wi-Fi devices has been assessed in a sample of 6 primary and secondary schools during classroom lessons. For the 146 individual laptops investigated, the range of duty factors was from 0.02 to 0.91%, with a mean of 0.08% (SD 0.10%). The duty factors of access points from 7 networks ranged from 1.0% to 11.7% with a mean of 4.79% (SD 3.76%). Data gathered with transmit time measuring devices attached to laptops also showed similar results. Within the present limited sample, the range of duty factors from laptops and access points were found to be broadly similar for primary and secondary schools. Applying these duty factors to previously published results from this project, the maximum time-averaged power density from a laptop would be 220 μW m(-2), at a distance of 0.5 m and the peak localised SAR predicted in the torso region of a 10 year old child model, at 34 cm from the antenna, would be 80 μW kg(-1). Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  16. Simulations of the HIE-ISOLDE radio frequency quadrupole cooler and buncher vacuum using the Monte Carlo test particle code Molflow

    CERN Document Server

    Hermann, M; Vandoni, G; Kersevan, R

    2013-01-01

    The existing ISOLDE radio frequency quadrupole cooler and buncher (RFQCB) will be upgraded in the framework of the HIE-ISOLDE design study. In order to improve beam properties, the upgrade includes vacuum optimization with the aim of tayloring the overall pressure profile: increasing gas pressure at the injection to enhance cooling and reducing it at the extraction to avoid emittance blow up while the beam is being bunched. This paper describes the vacuum modelling of the present RFQCB using Test Particle Monte Carlo (Molflow+). In order to benchmark the simulation results, real pressure profiles along the existing RFQCB are measured using variable helium flux in the cooling section and compared with the pressure profiles obtained with Molflow+. Vacuum conditions of the improved future RFQCB can then be simulated to validate its design. (C) 2013 Elsevier B.V. All rights reserved.

  17. Characterization of Nb Superconducting Radio Frequency Cavities Based On In-Situ STEM And EELS

    Science.gov (United States)

    Tao, Runzhe

    Niobium, a 4d transition metal, has the highest superconducting transition temperature (Tc=9.2K) of any elemental superconductor as type II superconductor with coherent length, sigma approximately that of the penetration length, lambda. Pure niobium is grey in color and very soft, which makes this metal easily fabricable into different shapes for superconducting radio- frequency (SRF) cavities. Such cavities are used in some modern accelerators (SNS, CEBAF, XFEL), and are intended for usage in the next generation of particle accelerators, such as ILC. Since the crucial part of the cavities is top 100 nm of Nb near the inner cavity surface, considering the penetration depth is around 40 nm, it has attracted more and more attention in improving the surface process for optimizing the performance of the cavities. Nowadays, the main treatment of the Nb surface includes electro polishing (EP), buffered chemical polishing (BCP), high temperature baking (800 °C, 1000 °C and 1200 °C) and mild baking (120 °C). Firstly, the two half cells are welded together and the weld line is quite rough; there exists a lot of visible pits and defects on the inner shell of cavities. In this Ph.D. thesis, novel techniques in a scanning transmission electron microscope (STEM) that can be used to analyze the atomic scale structure-property relationship, both at room tem- perature and high/LN 2 temperature, are explored. Specifically, by using correlated Z-contrast imaging and electron energy loss spectrum (EELS), the structure, composition and bonding can be characterized directly on the atomic scale, also, light atoms, like H, O and C, are visible in ABF images. For the examining the defect behavior on the cavity surface, heating and cold stages are involved to simulate the baking treatment and low-temperature environments. These studies will serve as an important reference for qualifying different surface treatments to further improve SRF cavities' performance. The experimental results

  18. Radio-frequency ring applicator: Energy distributions measured in the CDRH phantom

    NARCIS (Netherlands)

    G.C. van Rhoon (Gerard); P. Raskmark (P.); S.N. Hornsleth (S.); P.M. van den Berg (Peter)

    1994-01-01

    textabstractSAR distributions were measured in the CDRH phanton, a 1 cm fatequivalent shell filled with an abdomen-equivalent liquid (σ=0.4−1.0 S m−1; dimensions 22×32×57 cm) to demonstrate the feasibility of the ring applicator to obtain deep heating. The ring electrodes were fixed in a PVC tube;

  19. A study of the radio frequency spectrum emitted by high-energy air showers with LOFAR

    NARCIS (Netherlands)

    Rossetto, L.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Nelles, A.; Rachen, J. P.; Schellart, P.; Scholten, O.; Ter Veen, S.; Thoudam, S.; Trinh, T. N G

    2015-01-01

    The LOw Frequency ARray (LOFAR) is a multipurpose radio antenna array aimed to detect radio signals in the frequency range 10 - 240 MHz, covering a large surface in Northern Europe with a higher density in the Northern Netherlands. The detection of the radio signal emitted by extensive air showers

  20. Radio frequency energy for postharvest control of pests in dry nuts and legumes

    Science.gov (United States)

    Methyl bromide (MeBr) is widely used as a fumigant in insect control, but it is harmful to the environment and a concern to human health. The Montreal Protocol on Substances that Deplete the Ozone Layer calls for the elimination of MeBr by 2005 in developed countries and by 2015 in developing countr...

  1. Directed Energy: Medical Effects of Radio Frequency Exposure (Microwave & Millimeter Wave) - A Literature Review

    Science.gov (United States)

    2013-01-01

    for nutrition augmentation. If not possible, then parenteral nutrition augmentation should be done. Glucose should be kept at 80-110 mg/dL (insulin...rabbits at 2.45- GHz microwave exposure. IEEE Trans Biomed Eng 2010; 57(5):1234-42. 25. Armstrong LE. Exertional heatstroke in American football

  2. Direct conversion of light to radio frequency energy. [using photoklystrons for solar power satellites

    Science.gov (United States)

    Freeman, J. W.; Simons, S.

    1981-01-01

    A description is presented of the test results obtained with the latest models of the phototron. The phototron was conceived as a replacement for the high voltage solar cell-high power klystron combination for the solar power satellite concept. Physically, the phototron is a cylindrical evacuated glass tube with a photocathode, two grids, and a reflector electrode in a planar configuration. The phototron can be operated either in a biased mode where a low voltage is used to accelerate the electron beam produced by the photocathode or in an unbiased mode referred to as self-oscillation. The device is easily modulated by light input or voltage to broadcast in AM or FM. The range of operation of the present test model phototrons is from 2 to 200 MHz.

  3. Radio frequency energy harvesting and low power data transmission for autonomous wireless sensor nodes

    NARCIS (Netherlands)

    Rodrigues Mansano, A.L.

    2016-01-01

    Since the Internet of Things (IoT) is expected to be the new technology to drive the semiconductor industry, significant research efforts have been made to develop new circuit and system techniques for autonomous/very low-power operation of wireless sensor nodes. Very low-power consumption of

  4. Evaluation of speech recognition of cochlear implant recipients using a personal digital adaptive radio frequency system.

    Science.gov (United States)

    Wolfe, Jace; Morais, Mila; Schafer, Erin; Mills, Emily; Mülder, Hans E; Goldbeck, Felix; Marquis, Francois; John, Andrew; Hudson, Mary; Peters, B Robert; Lianos, Leslie

    2013-09-01

    Previous research supports the use of frequency modulation (FM) systems for improving speech recognition in noise of individuals with cochlear implants (CIs). However, at this time, there is no published research on the potential speech recognition benefit of new digital adaptive wireless radio transmission systems. The goal of this study was to compare speech recognition in quiet and in noise of CI recipients while using traditional, fixed-gain analog FM systems, adaptive analog FM systems, and adaptive digital wireless radio frequency transmission systems. A three-way repeated-measures design was used to examine performance differences among devices, among speech recognition conditions in quiet and in increasing levels of background noise, and between users of Advanced Bionics and Cochlear CIs. Seventeen users of Advanced Bionics Harmony CI sound processors and 20 users of Cochlear Nucleus 5 sound processors were included in the study. Participants were tested in a total of 32 speech-recognition-in noise-test conditions, which included one no-FM and three device conditions (fixed-gain FM, adaptive FM, and adaptive digital) at the following signal levels: 64 dBA speech (at the location of the participant) in quiet and 64 dBA speech with competing noise at 50, 55, 60, 65, 70, 75, and 80 dBA noise levels. No significant differences were detected between the users of Advanced Bionics and Cochlear CIs. All of the radio frequency system conditions (i.e., fixed-gain FM, adaptive FM, and adaptive digital) outperformed the no-FM conditions in test situations with competing noise. Specifically, in conditions with 70, 75, and 80 dBA of competing noise, the adaptive digital system provided better performance than the fixed-gain and adaptive FM systems. The adaptive FM system did provide better performance than the fixed-gain FM system at 70 and 75 dBA of competing noise. At the lower noise levels of 50, 55, 60, and 65 dBA, no significant differences were detected across the

  5. A radio frequency tracing experiment of bedload transport in a small braided mountain stream

    Science.gov (United States)

    Liebault, F.; Chapuis, M.; Bellot, H.; Deschatres, M.

    2009-04-01

    Radio frequency identification technology is used for monitoring the displacement of coarse particles in streams since the beginning of the 2000s. Passive integrated transponders (PIT tags) are small, cheap and long-lasting electronic tags that can be programmed with their own identification code. Initially used in environmental research for animal tracking, they have been deployed successfully in a variety of fluvial environments for coarse sediment tracing. Pioneering studies conducted in both semiarid and humid small upland streams with low intensity bedload transport gave recovery rates above 85% (Nichols 2004; Lamarre et al. 2005). Here we present an experiment of radio frequency sediment tracing implemented on a small braided mountain stream with a high intensity bedload transport and a wide active channel (mean active channel width: about 20 m). The study site is the Bouinenc Torrent, a tributary to the Bléone River in SE France that drains a 39 km² mountainous drainage basin of the Southern Prealps. In spring 2008, we deployed 451 tracers with b-axis ranging from 23 to 520 mm. Tracers were deployed along 8 cross sections located in the upstream part of the lowest 2.3 km of the stream. We developed a RFID detection system composed of an antenna and a reader unit; this system is characterized by a range of detection of 80 cm in optimal configuration. Two small intensity flow events occurred in June 2008 and entrained the tracers deployed in the most active part of the active channel. We mapped the position of the displaced tracers with a dGPS in July 2008. We obtained an overall recovery rate of 88%. The recovery rate calculated for the active tracers (those that were displaced after the flow events) was 76%. The projection of the tracer dispersion cloud on high resolution aerial photographs obtained with a drone allows us to calculate the distance of transport for each tracer. Mean and maximal distances of transport were respectively 796 m (+/- 53 m) and 2

  6. Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood-brain barrier in male & female rats.

    Science.gov (United States)

    Sırav, Bahriye; Seyhan, Nesrin

    2016-09-01

    With the increased use of mobile phones, their biological and health effects have become more important. Usage of mobile phones near the head increases the possibility of effects on brain tissue. This study was designed to investigate the possible effects of pulse modulated 900MHz and 1800MHz radio-frequency radiation on the permeability of blood-brain barrier of rats. Study was performed with 6 groups of young adult male and female wistar albino rats. The permeability of blood-brain barrier to intravenously injected evans blue dye was quantitatively examined for both control and radio-frequency radiarion exposed groups. For male groups; Evans blue content in the whole brain was found to be 0.08±0.01mg% in the control, 0.13±0.03mg% in 900MHz exposed and 0.26±0.05mg% in 1800MHz exposed animals. In both male radio-frequency radiation exposed groups, the permeability of blood-brain barrier found to be increased with respect to the controls (pradiation exposure was found more effective on the male animals (p0.01). However 900MHz pulse modulated radio-frequency exposure was found effective on the permeability of blood-brain barrier of female animals. Results have shown that 20min pulse modulated radio-frequency radiation exposure of 900MHz and 1800MHz induces an effect and increases the permeability of blood-brain barrier of male rats. For females, 900MHz was found effective and it could be concluded that this result may due to the physiological differences between female and male animals. The results of this study suggest that mobile phone radation could lead to increase the permeability of blood-brain barrier under non-thermal exposure levels. More studies are needed to demonstrate the mechanisms of that breakdown. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Micro-miniature radio frequency transmitter for communication and tracking applications

    Energy Technology Data Exchange (ETDEWEB)

    Crutcher, R.I.; Emery, M.S.; Falter, K.G.; Nowlin, C.H. [Oak Ridge National Lab., TN (United States); Rochelle, J.M.; Clonts, L.G. [Univ. of Tennessee, Knoxville, TN (United States). Electrical Engineering Dept.

    1996-12-31

    A micro-miniature radio frequency (rf) transmitter has been developed and demonstrated by the Oak Ridge National Laboratory. The objective of the rf transmitter development was to maximize the transmission distance while drastically shrinking the overall transmitter size, including antenna. Based on analysis and testing, an application-specific integrated circuit (ASIC) with a 16-GHz gallium arsenide (GaAs) oscillator and integrated on-chip antenna was designed and fabricated using microwave monolithic integrated circuit (MMIC) technology. Details of the development and the results of various field tests will be discussed. The rf transmitter is applicable to covert surveillance and tracking scenarios due to its small size of 2.2 x 2.2 mm, including the antenna. Additionally, the 16-GHz frequency is well above the operational range of consumer-grade radio scanners, providing a degree of protection from unauthorized interception. Variations of the transmitter design have been demonstrated for tracking and tagging beacons, transmission of digital data, and transmission of real-time analog video from a surveillance camera. Preliminary laboratory measurements indicate adaptability to direct-sequence spread-spectrum transmission, providing a low probability of intercept and/or detection. Concepts related to law enforcement applications will be presented.

  8. Emissive sheath measurements in the afterglow of a radio frequency plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sheehan, J. P., E-mail: sheehanj@umich.edu; Hershkowitz, N. [Nuclear Engineering and Engineering Physics, University of Wisconsin—Madison, Madison, Wisconsin 53706 (United States); Barnat, E. V.; Weatherford, B. R. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Kaganovich, I. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

    2014-01-15

    The difference between the plasma potential and the floating potential of a highly emissive planar surface was measured in the afterglow of a radio frequency discharge. A Langmuir probe was used to measure the electron temperature and an emissive probe was used to measure the spatial distribution of the potential using the inflection point in the limit of zero emission technique. Time-resolved measurements were made using the slow-sweep method, a technique for measuring time-resolved current-voltage traces. This was the first time the inflection point in the limit of zero emission was used to make time-resolved measurements. Measurements of the potential profile of the presheath indicate that the potential penetrated approximately 50% farther into the plasma when a surface was emitting electrons. The experiments confirmed a recent kinetic theory of emissive sheaths, demonstrating that late in the afterglow as the plasma electron temperature approached the emitted electron temperature, the emissive sheath potential shrank to zero. However, the difference between the plasma potential and the floating potential of a highly emissive planar surface data appeared to be much less sensitive to the electron temperature ratio than the theory predicts.

  9. The Design and Operation of Ultra-Sensitive and Tunable Radio-Frequency Interferometers.

    Science.gov (United States)

    Cui, Yan; Wang, Pingshan

    2014-12-01

    Dielectric spectroscopy (DS) is an important technique for scientific and technological investigations in various areas. DS sensitivity and operating frequency ranges are critical for many applications, including lab-on-chip development where sample volumes are small with a wide range of dynamic processes to probe. In this work, we present the design and operation considerations of radio-frequency (RF) interferometers that are based on power-dividers (PDs) and quadrature-hybrids (QHs). Such interferometers are proposed to address the sensitivity and frequency tuning challenges of current DS techniques. Verified algorithms together with mathematical models are presented to quantify material properties from scattering parameters for three common transmission line sensing structures, i.e., coplanar waveguides (CPWs), conductor-backed CPWs, and microstrip lines. A high-sensitivity and stable QH-based interferometer is demonstrated by measuring glucose-water solution at a concentration level that is ten times lower than some recent RF sensors while our sample volume is ~1 nL. Composition analysis of ternary mixture solutions are also demonstrated with a PD-based interferometer. Further work is needed to address issues like system automation, model improvement at high frequencies, and interferometer scaling.

  10. Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

    Science.gov (United States)

    Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Paval, Jaijesh; Kedage, Vivekananda; Bhat, M Shankaranarayana; Nayak, Satheesha; Bhat, P Gopalakrishna

    2013-07-01

    In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

  11. Analysis of the possibility of applying radio frequency identification in the flexible production process

    Directory of Open Access Journals (Sweden)

    Mirkov Gligorije I.

    2017-01-01

    Full Text Available Flexible manufacturing systems (FMS as a complex and stochastic environments require the development of innovative, intelligent control architectures in order to improve flexibility, agility and reconfiguration. Distribution management system addresses this challenge by introducing the optimal process management which is supported by the autonomous control units that cooperate with each other. Most of the existing transport management system, has a lack of flexibility and agility, especially in cases where a large variety of products, a small representation of parts of smaller dimensions. In such cases, the system is insensitive to random ‘ad-hoc’ events. Phase transport parts through flexible manufacturing system can be potentially used to obtain information about the product in order to process management. Radio frequency identification (RFID has been introduced as new technology allows monitoring, identifying and categorizing parts. This paper gives grounds on the flexible cell architecture (FMC and the deployment of RFID devices with the aim of the distribution and tracking of parts. The paper gives an example of setting agent base control architecture FMC.

  12. Analysis of Glass-Reinforced Epoxy Material for Radio Frequency Resonator

    Science.gov (United States)

    Islam, M. T.; Misran, N.; Yatim, Baharudin

    2014-01-01

    A radio frequency (RF) resonator using glass-reinforced epoxy material for C and X band is proposed in this paper. Microstrip line technology for RF over glass-reinforced epoxy material is analyzed. Coupling mechanism over RF material and parasitic coupling performance is explained utilizing even and odd mode impedance with relevant equivalent circuit. Babinet's principle is deployed to explicate the circular slot ground plane of the proposed resonator. The resonator is designed over four materials from different backgrounds which are glass-reinforced epoxy, polyester, gallium arsenide (GaAs), and rogers RO 4350B. Parametric studies and optimization algorithm are applied over the geometry of the microstrip resonator to achieve dual band response for C and X band. Resonator behaviors for different materials are concluded and compared for the same structure. The final design is fabricated over glass-reinforced epoxy material. The fabricated resonator shows a maximum directivity of 5.65 dBi and 6.62 dBi at 5.84 GHz and 8.16 GHz, respectively. The lowest resonance response is less than −20 dB for C band and −34 dB for X band. The resonator is prototyped using LPKF (S63) drilling machine to study the material behavior. PMID:24977230

  13. Electron current extraction from radio frequency excited micro-dielectric barrier discharges

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun-Chieh; Kushner, Mark J. [Electrical Engineering and Computer Science Department, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109 (United States); Leoni, Napoleon; Birecki, Henryk; Gila, Omer [Hewlett Packard Research Labs, Palo Alto, California 94304 (United States)

    2013-01-21

    Micro dielectric barrier discharges (mDBDs) consist of micro-plasma devices (10-100 {mu}m diameter) in which the electrodes are fully or partially covered by dielectrics, and often operate at atmospheric pressure driven with radio frequency (rf) waveforms. In certain applications, it may be desirable to extract electron current out of the mDBD plasma, which necessitates a third electrode. As a result, the physical structure of the m-DBD and the electron emitting properties of its materials are important to its operation. In this paper, results from a two-dimensional computer simulation of current extraction from mDBDs sustained in atmospheric pressure N{sub 2} will be discussed. The mDBDs are sandwich structures with an opening of tens-of-microns excited with rf voltage waveforms of up to 25 MHz. Following avalanche by electron impact ionization in the mDBD cavity, the plasma can be expelled from the cavity towards the extraction electrode during the part of the rf cycle when the extraction electrode appears anodic. The electron current extraction can be enhanced by biasing this electrode. The charge collection can be controlled by choice of rf frequency, rf driving voltage, and permittivity of the dielectric barrier.

  14. Separation of Radio-Frequency Sources and Localization of Partial Discharges in Noisy Environments

    Science.gov (United States)

    Robles, Guillermo; Fresno, José Manuel; Martínez-Tarifa, Juan Manuel

    2015-01-01

    The detection of partial discharges (PD) can help in early-warning detection systems to protect critical assets in power systems. The radio-frequency emission of these events can be measured with antennas even when the equipment is in service which reduces dramatically the maintenance costs and favours the implementation of condition-based monitoring systems. The drawback of these type of measurements is the difficulty of having a reference signal to study the events in a classical phase-resolved partial discharge pattern (PRPD). Therefore, in open-air substations and overhead lines where interferences from radio and TV broadcasting and mobile communications are important sources of noise and other pulsed interferences from rectifiers or inverters can be present, it is difficult to identify whether there is partial discharges activity or not. This paper proposes a robust method to separate the events captured with the antennas, identify which of them are partial discharges and localize the piece of equipment that is having problems. The separation is done with power ratio (PR) maps based on the spectral characteristics of the signal and the identification of the type of event is done localizing the source with an array of four antennas. Several classical methods to calculate the time differences of arrival (TDOA) of the emission to the antennas have been tested, and the localization is done using particle swarm optimization (PSO) to minimize a distance function. PMID:25923935

  15. Iron Oxide Nanoparticle-Based Magnetic Ink Development for Fully Printed Tunable Radio-Frequency Devices

    KAUST Repository

    Vaseem, Mohammad

    2018-01-30

    The field of printed electronics is still in its infancy and most of the reported work is based on commercially available nanoparticle-based metallic inks. Although fully printed devices that employ dielectric/semiconductor inks have recently been reported, there is a dearth of functional inks that can demonstrate controllable devices. The lack of availability of functional inks is a barrier to the widespread use of fully printed devices. For radio-frequency electronics, magnetic materials have many uses in reconfigurable components but rely on expensive and rigid ferrite materials. A suitable magnetic ink can facilitate the realization of fully printed, magnetically controlled, tunable devices. This report presents the development of an iron oxide nanoparticle-based magnetic ink. First, a tunable inductor is fully printed using iron oxide nanoparticle-based magnetic ink. Furthermore, iron oxide nanoparticles are functionalized with oleic acid to make them compatible with a UV-curable SU8 solution. Functionalized iron oxide nanoparticles are successfully embedded in the SU8 matrix to make a magnetic substrate. The as-fabricated substrate is characterized for its magnetostatic and microwave properties. A frequency tunable printed patch antenna is demonstrated using the magnetic and in-house silver-organo-complex inks. This is a step toward low-cost, fully printed, controllable electronic components.

  16. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Munafò, A., E-mail: munafo@illinois.edu; Alfuhaid, S. A., E-mail: alfuhai2@illinois.edu; Panesi, M., E-mail: mpanesi@illinois.edu [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Talbot Laboratory, 104 S. Wright St., Urbana, Illinois 61801 (United States); Cambier, J.-L., E-mail: jean-luc.cambier@us.af.mil [Edwards Air Force Base Research Laboratory, 10 E. Saturn Blvd., Edwards AFB, California 93524 (United States)

    2015-10-07

    The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.

  17. Spatial transformation-enabled electromagnetic devices: from radio frequencies to optical wavelengths.

    Science.gov (United States)

    Jiang, Zhi Hao; Turpin, Jeremy P; Morgan, Kennith; Lu, Bingqian; Werner, Douglas H

    2015-08-28

    Transformation optics provides scientists and engineers with a new powerful design paradigm to manipulate the flow of electromagnetic waves in a user-defined manner and with unprecedented flexibility, by controlling the spatial distribution of the electromagnetic properties of a medium. Using this approach, over the past decade, various previously undiscovered physical wave phenomena have been revealed and novel electromagnetic devices have been demonstrated throughout the electromagnetic spectrum. In this paper, we present versatile theoretical and experimental investigations on designing transformation optics-enabled devices for shaping electromagnetic wave radiation and guidance, at both radio frequencies and optical wavelengths. Different from conventional coordinate transformations, more advanced and versatile coordinate transformations are exploited here to benefit diverse applications, thereby providing expanded design flexibility, enhanced device performance, as well as reduced implementation complexity. These design examples demonstrate the comprehensive capability of transformation optics in controlling electromagnetic waves, while the associated novel devices will open up new paths towards future integrated electromagnetic component synthesis and design, from microwave to optical spectral regimes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  18. Study of electron-extraction characteristics of an inductively coupled radio-frequency plasma neutralizer

    Science.gov (United States)

    Jianwu, HE; Longfei, MA; Senwen, XUE; Chu, ZHANG; Li, DUAN; Qi, KANG

    2018-01-01

    Inductively coupled radio-frequency (RF) plasma neutralizer (RPN) is an insert-free device that can be employed as an electron source in electric propulsion applications. Electron-extraction characteristics of the RPN are related to the bulk plasma parameters and the device’s geometry. Therefore, the effects of different electron-extraction apertures and operational parameters upon the electron-extraction characteristics are investigated according to the global nonambipolar flow and sheath model. Moreover, these models can also be used to explain why the electron-extraction characteristics of the RPN strongly depend upon the formation of the anode spot. During the experimental study, two types of anode spots are observed. Each of them has unique characteristics of electron extraction. Moreover, the hysteresis of an anode spot is observed by changing the xenon volume-flow rates or the bias voltages. In addition, the rapid ignited method, gas-utilization factor, electron-extraction cost and other factors that need to be considered in the design of the RPN are also discussed.

  19. Separation of Radio-Frequency Sources and Localization of Partial Discharges in Noisy Environments

    Directory of Open Access Journals (Sweden)

    Guillermo Robles

    2015-04-01

    Full Text Available The detection of partial discharges (PD can help in early-warning detection systems to protect critical assets in power systems. The radio-frequency emission of these events can be measured with antennas even when the equipment is in service which reduces dramatically the maintenance costs and favours the implementation of condition-based monitoring systems. The drawback of these type of measurements is the difficulty of having a reference signal to study the events in a classical phase-resolved partial discharge pattern (PRPD. Therefore, in open-air substations and overhead lines where interferences from radio and TV broadcasting and mobile communications are important sources of noise and other pulsed interferences from rectifiers or inverters can be present, it is difficult to identify whether there is partial discharges activity or not. This paper proposes a robust method to separate the events captured with the antennas, identify which of them are partial discharges and localize the piece of equipment that is having problems. The separation is done with power ratio (PR maps based on the spectral characteristics of the signal and the identification of the type of event is done localizing the source with an array of four antennas. Several classical methods to calculate the time differences of arrival (TDOA of the emission to the antennas have been tested, and the localization is done using particle swarm optimization (PSO to minimize a distance function.

  20. Microstructural characterization of radio frequency and direct current plasma-sprayed Al2O3 coatings

    Science.gov (United States)

    Chen, H. C.; Pfender, E.; Dzur, B.; Nutsch, G.

    2000-06-01

    Microstructures of radio frequency (RF) and direct current (DC) plasma-sprayed Al2O3 coatings deposited onto steel substrates were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), electron microprobe analysis (EMPA), polarizing optical microscopy (OM), and transmission electron microscopy (TEM). Because RF and DC plasmas produce different particle heating and acceleration, the morphology, phase structure, and fracture modes of the coatings vary substantially. In the case of RF coatings, a clear lamellar microstructure with relatively thick lamellae was observed, which is due to the large particles and the low particle velocities, with α-Al2O3 as the predominant phase and with delamination type of fracture detected on the fracture surface. In contrast, the DC coatings consisted of predominantly metastable γ-Al2O3 as well as amorphous phases, with a mixed fracture mode of the coating observed. In spite of limited interfacial interdiffusion detected by EMPA, TEM showed an interfacial layer existing at the interface between the coating and the substrate for both cases. For RF coatings, the interfacial layer on the order of 1 µm was composed of three sublayers, each of which was different in composition and morphology. However, the interfacial layer for the DC coating consisted primarily of an amorphous phase, containing both coating and substrate materials with or without platelike microcrystals; although in some regions a thick amorphous Al2O3 layer was in direct contact with the substrate.

  1. A Novel Micro- and Nano-Scale Positioning Sensor Based on Radio Frequency Resonant Cavities

    Science.gov (United States)

    Asua, Estibaliz; Etxebarria, Victor; García-Arribas, Alfredo; Feutchwanger, Jorge; Portilla, Joaquín; Lucas, Julio

    2014-01-01

    In many micro- and nano-scale technological applications high sensitivity displacement sensors are needed, especially in ultraprecision metrology and manufacturing. In this work a new way of sensing displacement based on radio frequency resonant cavities is presented and experimentally demonstrated using a first laboratory prototype. The principle of operation of the new transducer is summarized and tested. Furthermore, an electronic interface that can be used together with the displacement transducer is designed and proved. It has been experimentally demonstrated that very high and linear sensitivity characteristic curves, in the range of some kHz/nm; are easily obtainable using this kind of transducer when it is combined with a laboratory network analyzer. In order to replace a network analyzer and provide a more affordable, self-contained, compact solution, an electronic interface has been designed, preserving as much as possible the excellent performance of the transducer, and turning it into a true standalone positioning sensor. The results obtained using the transducer together with a first prototype of the electronic interface built with cheap discrete elements show that positioning accuracies in the micrometer range are obtainable using this cost-effective solution. Better accuracies would also be attainable but using more involved and costly electronics interfaces. PMID:24887041

  2. A compact radio frequency quadrupole for ion bunching in the WITCH experiment

    CERN Document Server

    Traykov, E.; Breitenfeldt, M.; Delahaye, P.; De Leebeeck, V.; Friedag, P.; Herlert, A.; Geeraert, N.; Heirman, W.; Lonne, P.I.; Mader, J.; Roccia, S.; Soti, G.; Tandecki, M.; Timmermans, M.; Thiboud, J.; Van Gorp, S.; Wauters, F.; Weinheimer, C.; Zakoucky, D.; Severijns, N.

    2011-01-01

    During the last several years the WITCH (Weak Interaction Trap for CHarged particles) experimental setup at ISOLDE has undergone various upgrades aiming at improvement of general performance. An essential innovation, a compact Radio Frequency Quadrupole (RFQ) ion cooler and buncher device, was designed and successfully commissioned as a part of the off-line tuning system of WITCH. The RFQ is coupled to the existing surface ionization ion source providing high intensity ion bunches (up to 10(7) ions per bunch) towards the pulsed drift tube and the Penning traps of WITCH. This achievement allows for loading and tuning of the Penning traps in the domain of space charge limits and grants off-line operation independently of the REX-ISOLDE ion source. The current upgrade allows for a more thorough and frequent testing with bunched stable ion beams of high intensities, which will be used for studying various systematic effects involved in experiments with radioactive ions. (C) 2011 Elsevier B.V. All rights reserved.

  3. Influence of finite geometrical asymmetry of the electrodes in capacitively coupled radio frequency plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bora, B., E-mail: bbora@cchen.cl; Soto, L. [Comisión Chilena de Energía Nuclear, Santiago, Chile and Center for Research and Applications in Plasma Physics and Pulsed Power, P4 (Chile)

    2014-08-15

    Capacitively coupled radio frequency (CCRF) plasmas are widely studied in last decades due to the versatile applicability of energetic ions, chemically active species, radicals, and also energetic neutral species in many material processing fields including microelectronics, aerospace, and biology. A dc self-bias is known to generate naturally in geometrically asymmetric CCRF plasma because of the difference in electrode sizes known as geometrical asymmetry of the electrodes in order to compensate electron and ion flux to each electrode within one rf period. The plasma series resonance effect is also come into play due to the geometrical asymmetry and excited several harmonics of the fundamental in low pressure CCRF plasma. In this work, a 13.56 MHz CCRF plasma is studied on the based on the nonlinear global model of asymmetric CCRF discharge to understand the influences of finite geometrical asymmetry of the electrodes in terms of generation of dc self-bias and plasma heating. The nonlinear global model on asymmetric discharge has been modified by considering the sheath at the grounded electrode to taking account the finite geometrical asymmetry of the electrodes. The ion density inside both the sheaths has been taken into account by incorporating the steady-state fluid equations for ions considering that the applied rf frequency is higher than the typical ion plasma frequency. Details results on the influences of geometrical asymmetry on the generation of dc self-bias and plasma heating are discussed.

  4. An Analysis of the Privacy Threat in Vehicular Ad Hoc Networks due to Radio Frequency Fingerprinting

    Directory of Open Access Journals (Sweden)

    Gianmarco Baldini

    2017-01-01

    Full Text Available In Vehicular Ad Hoc Networks (VANETs used in the road transportation sector, privacy risks may arise because vehicles could be tracked on the basis of the information transmitted by the Vehicle to Vehicle (V2V and Vehicle to Infrastructure (V2I communications implemented with the Dedicated Short Range Communications (DSRC standards operating at 5.9 GHz. Various techniques have been proposed in the literature to mitigate these privacy risks including the use of pseudonym schemes, but they are mostly focused on data anonymization at the network and application layer. At the physical layer, the capability to accurately identify and fingerprint wireless devices through their radio frequency (RF emissions has been demonstrated in the literature. This capability may generate a privacy threat because vehicles can be tracked using the RF emissions of their DSRC devices. This paper investigates the privacy risks related to RF fingerprinting to determine if privacy breaches are feasible in practice. In particular, this paper analyzes the tracking accuracy in challenging RF environments with high attenuation and fading.

  5. Wavelet-based Characterization of Small-scale Solar Emission Features at Low Radio Frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, A. [Indian Institute of Science Education and Research, Pune-411008 (India); Sharma, R.; Oberoi, D. [National Centre for Radio Astrophysics, Tata Institute for Fundamental Research, Pune 411007 (India); Das, S. B. [Indian Institute of Science Education and Research, Kolkata-741249 (India); Pankratius, V.; Lonsdale, C. J.; Cappallo, R. J.; Corey, B. E.; Kratzenberg, E. [MIT Haystack Observatory, Westford, MA 01886 (United States); Timar, B. [California Institute of Technology, Pasadena, CA 91125 (United States); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Briggs, F. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Deshpande, A. A. [Raman Research Institute, Bangalore 560080 (India); Emrich, D. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); Goeke, R. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Greenhill, L. J. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hazelton, B. J. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140 (New Zealand); Kaplan, D. L. [Department of Physics, University of Wisconsin–Milwaukee, Milwaukee, WI 53201 (United States); Kasper, J. C., E-mail: akshay@students.iiserpune.ac.in [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); and others

    2017-07-01

    Low radio frequency solar observations using the Murchison Widefield Array have recently revealed the presence of numerous weak short-lived narrowband emission features, even during moderately quiet solar conditions. These nonthermal features occur at rates of many thousands per hour in the 30.72 MHz observing bandwidth, and hence necessarily require an automated approach for their detection and characterization. Here, we employ continuous wavelet transform using a mother Ricker wavelet for feature detection from the dynamic spectrum. We establish the efficacy of this approach and present the first statistically robust characterization of the properties of these features. In particular, we examine distributions of their peak flux densities, spectral spans, temporal spans, and peak frequencies. We can reliably detect features weaker than 1 SFU, making them, to the best of our knowledge, the weakest bursts reported in literature. The distribution of their peak flux densities follows a power law with an index of −2.23 in the 12–155 SFU range, implying that they can provide an energetically significant contribution to coronal and chromospheric heating. These features typically last for 1–2 s and possess bandwidths of about 4–5 MHz. Their occurrence rate remains fairly flat in the 140–210 MHz frequency range. At the time resolution of the data, they appear as stationary bursts, exhibiting no perceptible frequency drift. These features also appear to ride on a broadband background continuum, hinting at the likelihood of them being weak type-I bursts.

  6. A comparison of conventional and radio frequency tempering of beef meats: Effects on product temperature distribution.

    Science.gov (United States)

    Farag, K W; Lyng, J G; Morgan, D J; Cronin, D A

    2008-10-01

    This study aimed to develop radio frequency (RF) pilot-scale protocols for tempering beef meat blends (4kg blocks) to achieve average temperatures between -2 and -5°C. Post-tempering temperature distribution in these blocks was compared to products tempered by conventional methods. The optimum RF power-time combination for tempering lean and 50:50 lean:fat mixtures to the target range was 500W for 11min which produced respective means of -3.6°C (s.d. 1.1) and -3.4°C (s.d. 1.5). In contrast, 400W for 11min was optimum for fat (mean -4.9°C, s.d. 2.1). This study shows the principal advantages of RF over conventional tempering as an approximate 30 fold tempering time reduction and a greater uniformity of end point temperature distribution under the conditions employed. Furthermore, power consumption was reduced approximately ninefold with RF compared to conventional tempering. More uniform temperature distribution was achieved in samples that were comminuted to a greater extent.

  7. The radio-frequency fluctuation effect on the floating harmonic method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaewon; Kim, Kyung-Hyun [Department of Electrical Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of); Kim, Dong-Hwan [Department of Nanoscale Semiconductor Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of); Chung, Chin-Wook, E-mail: joykang@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of); Department of Nanoscale Semiconductor Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of)

    2016-08-15

    The radio-frequency (RF) plasma diagnostics with an electrical probe facing a challenge, because the RF fluctuation oscillates the plasma potential and distorts the current-voltage (I-V) curve. As Langmuir probe is widely used in plasma diagnostics, many researchers have been studying the effect of RF fluctuation on probe and compensation methods. On the other hand, there have not been enough studies on the fluctuation effect on the floating harmonic method. Therefore, we investigated the impact of RF fluctuation on the floating harmonic method theoretically and experimentally. When the electrons are in ideal Maxwellian distribution, the floating potential is negatively shifted by the RF fluctuation, but the fluctuation does not distort I-V curve around the floating potential. However, in practical plasmas, the I-V curve and their harmonic components are distorted. This RF fluctuation effect becomes more significant in a low density plasma with a high impedance sheath. The second harmonic current decreases with the RF fluctuation while the first harmonic current is merely affected. Therefore, the electron temperatures measured with the floating harmonic method under low density plasma with uncompensated probe are overestimated than the results obtained with the compensated probe.

  8. Spin biochemistry modulates reactive oxygen species (ROS production by radio frequency magnetic fields.

    Directory of Open Access Journals (Sweden)

    Robert J Usselman

    Full Text Available The effects of weak magnetic fields on the biological production of reactive oxygen species (ROS from intracellular superoxide (O2•- and extracellular hydrogen peroxide (H2O2 were investigated in vitro with rat pulmonary arterial smooth muscle cells (rPASMC. A decrease in O2•- and an increase in H2O2 concentrations were observed in the presence of a 7 MHz radio frequency (RF at 10 μTRMS and static 45 μT magnetic fields. We propose that O2•- and H2O2 production in some metabolic processes occur through singlet-triplet modulation of semiquinone flavin (FADH• enzymes and O2•- spin-correlated radical pairs. Spin-radical pair products are modulated by the 7 MHz RF magnetic fields that presumably decouple flavin hyperfine interactions during spin coherence. RF flavin hyperfine decoupling results in an increase of H2O2 singlet state products, which creates cellular oxidative stress and acts as a secondary messenger that affects cellular proliferation. This study demonstrates the interplay between O2•- and H2O2 production when influenced by RF magnetic fields and underscores the subtle effects of low-frequency magnetic fields on oxidative metabolism, ROS signaling, and cellular growth.

  9. Pilot-scale radio frequency pasteurisation of chili powder: heating uniformity and heating model.

    Science.gov (United States)

    Li, Yukun; Zhang, Yongdi; Lei, Yujie; Fu, Hongfei; Chen, Xiangwei; Wang, Yunyang

    2016-08-01

    Microbial contamination is a vital obstacle needed to overcome for food safety of condiments. Radio frequency (RF) pasteurisation is a new technology to solve this obstacle. Temperature distribution and heating uniformity of sample, which are influenced by different factors, are the most important things affecting the nutritional ingredients and microbial safety of sample in the process of RF pasteurisation. This study demonstrated the location of cold spot in chili powder by analysing temperature distribution in horizontal and vertical direction. The related models were established and the accuracy was verified. Cold spot located on the centre of sample surface in the process of RF pasteurisation. The averaged temperature of sample increased linearly. The uniformity index decreased as the averaged temperature increased. Both the correlation coefficient of two equations were greater than 0.91. The error value of heating rate and heating uniformity index was 0.54% and 0.75% between the measured value and predicted value. Electric field was not uniformly distributed between RF parallel-plate electrodes in the RF pasteurisation of chili powder. The heating models were reliable to predict experiment results with high precision and accuracy. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  10. Dust coupling parameter of radio-frequency-discharge complex plasma under microgravity conditions

    Science.gov (United States)

    Zhukhovitskii, D. I.; Naumkin, V. N.; Khusnulgatin, A. I.; Molotkov, V. I.; Lipaev, A. M.

    2017-10-01

    Oscillation of particles in a dust crystal formed in a low-pressure radio-frequency gas discharge under microgravity conditions is studied. Analysis of experimental data obtained in our previous study shows that the oscillations are highly isotropic and nearly homogeneous in the bulk of a dust crystal; oscillations of the neighboring particles are significantly correlated. We demonstrate that the standard deviation of the particle radius vector along with the local particle number density fully define the coupling parameter of the particle subsystem. The latter proves to be of the order of 100, which is two orders of magnitude lower than the coupling parameter estimated for the Brownian diffusion of particles with the gas temperature. This means significant kinetic overheating of particles under stationary conditions. A theoretical interpretation of the large amplitude of oscillation implies the increase of particle charge fluctuations in the dust crystal. The theoretical estimates are based on the ionization equation of state for the complex plasma and the equation for the plasma perturbation evolution. They are shown to match the results of experimental data processing. Estimated order of magnitude of the coupling parameter accounts for the existence of the solid-liquid phase transition observed for similar systems in experiments.

  11. Anthropogenic Radio-Frequency Electromagnetic Fields Elicit Neuropathic Pain in an Amputation Model.

    Science.gov (United States)

    Black, Bryan; Granja-Vazquez, Rafael; Johnston, Benjamin R; Jones, Erick; Romero-Ortega, Mario

    2016-01-01

    Anecdotal and clinical reports have suggested that radio-frequency electromagnetic fields (RF EMFs) may serve as a trigger for neuropathic pain. However, these reports have been widely disregarded, as the epidemiological effects of electromagnetic fields have not been systematically proven, and are highly controversial. Here, we demonstrate that anthropogenic RF EMFs elicit post-neurotomy pain in a tibial neuroma transposition model. Behavioral assays indicate a persistent and significant pain response to RF EMFs when compared to SHAM surgery groups. Laser thermometry revealed a transient skin temperature increase during stimulation. Furthermore, immunofluorescence revealed an increased expression of temperature sensitive cation channels (TRPV4) in the neuroma bulb, suggesting that RF EMF-induced pain may be due to cytokine-mediated channel dysregulation and hypersensitization, leading to thermal allodynia. Additional behavioral assays were performed using an infrared heating lamp in place of the RF stimulus. While thermally-induced pain responses were observed, the response frequency and progression did not recapitulate the RF EMF effects. In vitro calcium imaging experiments demonstrated that our RF EMF stimulus is sufficient to directly contribute to the depolarization of dissociated sensory neurons. Furthermore, the perfusion of inflammatory cytokine TNF-α resulted in a significantly higher percentage of active sensory neurons during RF EMF stimulation. These results substantiate patient reports of RF EMF-pain, in the case of peripheral nerve injury, while confirming the public and scientific consensus that anthropogenic RF EMFs engender no adverse sensory effects in the general population.

  12. Performance characterization of screen printed radio frequency identification antennas with silver nanopaste

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong-Youn, E-mail: dongyoun.shin@gmail.co [Nanomachine Research Division, Korea Institute of Machinery and Materials, 171 Jang-dong, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of); Lee, Yongshik, E-mail: yongshik.lee@yonsei.ac.k [School of Electrical and Electronic Engineering, Yonsei University, 134 Sinchon-Dong, Seodaemun-Gu, Seoul, 120-749 (Korea, Republic of); Kim, Chung Hwan, E-mail: chkim@kimm.re.k [Nanomachine Research Division, Korea Institute of Machinery and Materials, 171 Jang-dong, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of)

    2009-09-01

    The era of wireless communication has come and it is going to flourish in the form of radio frequency identification (RFID) tags. The employment of RFID tags in daily commodities, however, is constrained due to the manufacturing cost. Therefore, industries in the field have sought for alternative manufacturing methods at an ultra low cost and various printing processes have been considered such as inkjet, gravure, flexo, off-set and screen. Although such printing processes are age-old, their applications have been mainly limited to graphic arts and design rules for electronic appliances have not been fully established yet. In this paper, the selection of ink and printing process to fabricate RFID antennas is discussed. The developed silver nanopaste in the range of 20 to 50 nm without the inclusion of microparticles and flakes was sintered at 120 {sup o}C for 1 min, which is lower than that of conventional silver paste with microparticles and flakes, and its resistivity was found to be approximately 3 {mu}{Omega} cm. The radiation performances of various screen printed RFID antennas with silver nanopaste were found comparable to those of copper etched ones.

  13. Radio Frequency Plasma Synthesis of Boron Nitride Nanotubes (BNNTs) for Structural Applications: Part I

    Science.gov (United States)

    Hales, Stephen J.; Alexa, Joel A.; Jensen, Brian J.; Thomsen, Donald L.

    2016-01-01

    It is evident that nanotubes, such as carbon, boron nitride and even silicon, offer great potential for many aerospace applications. The opportunity exists to harness the extremely high strength and stiffness exhibited by high-purity, low-defect nanotubes in structural materials. Even though the technology associated with carbon nanotube (CNT) development is mature, the mechanical property benefits have yet to be fully realized. Boron nitride nanotubes (BNNTs) offer similar structural benefits, but exhibit superior chemical and thermal stability. A broader range of potential structural applications results, particularly as reinforcing agents for metal- and ceramic- based composites. However, synthesis of BNNTs is more challenging than CNTs mainly because of the higher processing temperatures required, and mass production techniques have yet to emerge. A promising technique is radio frequency plasma spray (RFPS), which is an inductively coupled, very high temperature process. The lack of electrodes and the self- contained, inert gas environment lend themselves to an ultraclean product. It is the aim of this White Paper to survey the state of the art with regard to nano-material production by analyzing the pros and cons of existing methods. The intention is to combine the best concepts and apply the NASA Langley Research Center (LaRC) RFPS facility to reliably synthesize large quantities of consistent, high-purity BNNTs.

  14. Radical-pair-based magnetoreception in birds: radio-frequency experiments and the role of cryptochrome.

    Science.gov (United States)

    Nießner, Christine; Winklhofer, Michael

    2017-07-01

    The radical-pair hypothesis of magnetoreception has gained a lot of momentum, since the flavoprotein cryptochrome was postulated as a structural candidate to host magnetically sensitive chemical reactions. Here, we first discuss behavioral tests using radio-frequency magnetic fields (0.1-10 MHz) to specifically disturb a radical-pair-based avian magnetic compass sense. While disorienting effects of broadband RF magnetic fields have been replicated independently in two competing labs, the effects of monochromatic RF magnetic fields administered at the electronic Larmor frequency (~1.3 MHz) are disparate. We give technical recommendations for future RF experiments. We then focus on two candidate magnetoreceptor proteins in birds, Cry1a and Cry1b, two splice variants of the same gene (Cry1). Immunohistochemical studies have identified Cry1a in the outer segments of the ultraviolet/violet-sensitive cone photoreceptors and Cry1b in the cytosol of retinal ganglion cells. The identification of the host neurons of these cryptochromes and their subcellular expression patterns presents an important advance, but much work lies ahead to gain some functional understanding. In particular, interaction partners of cryptochrome Cry1a and Cry1b remain to be identified. A candidate partner for Cry4 was previously suggested, but awaits independent replication.

  15. Magnetoreception in the wood mouse (Apodemus sylvaticus): influence of weak frequency-modulated radio frequency fields

    Science.gov (United States)

    Malkemper, E. Pascal; Eder, Stephan H. K.; Begall, Sabine; Phillips, John B.; Winklhofer, Michael; Hart, Vlastimil; Burda, Hynek

    2015-01-01

    The mammalian magnetic sense is predominantly studied in species with reduced vision such as mole-rats and bats. Far less is known about surface-dwelling (epigeic) rodents with well-developed eyes. Here, we tested the wood mouse Apodemus sylvaticus for magnetoreception using a simple behavioural assay in which mice are allowed to build nests overnight in a visually symmetrical, circular arena. The tests were performed in the ambient magnetic field or in a field rotated by 90°. When plotted with respect to magnetic north, the nests were bimodally clustered in the northern and southern sectors, clearly indicating that the animals used magnetic cues. Additionally, mice were tested in the ambient magnetic field with a superimposed radio frequency magnetic field of the order of 100 nT. Wood mice exposed to a 0.9 to 5 MHz frequency sweep changed their preference from north-south to east-west. In contrast to birds, however, a constant frequency field tuned to the Larmor frequency (1.33 MHz) had no effect on mouse orientation. In sum, we demonstrated magnetoreception in wood mice and provide first evidence for a radical-pair mechanism in a mammal. PMID:25923312

  16. Development of a radio frequency heating system for sterilization of vacuum-packed fish in water.

    Science.gov (United States)

    Uemura, Kunihiko; Kanafusa, Sumiyo; Takahashi, Chieko; Kobayashi, Isao

    2017-04-01

    We developed equipment that quickly and uniformly heats packed whole fish in circulating tap water using radio frequency (RF) heating. Four vacuumed plastic-packed Pacific sauries in tap water were set in a radial arrangement between coaxial cylindrical electrodes in a closed vessel. For sterilization testing, Bacillus subtilis spores added in the center of the sauries were counted after treatment. For quality assurance, meat color and backbone hardness were measured after treatment. The temperature at the center of the sauries was increased up to 130 °C for 19 min using 9 kW RF heating, and up to 119 °C for 45 min using conventional heating (CH) at 120 °C. B. subtilis spores were decreased by five logarithmic orders using RF heating and by four logarithmic orders using CH. The RF-treated meat was brighter than the CH-treated meat, and the RF-treated backbone was softer than CH-treated one.

  17. Evaluation of radio-frequency heating in controlling Salmonella enterica in raw shelled almonds.

    Science.gov (United States)

    Jeong, Seul-Gi; Baik, Oon-Doo; Kang, Dong-Hyun

    2017-08-02

    This study was conducted to investigate the efficacy of radio-frequency (RF) heating to reduce Salmonella enterica serovars Enteritidis, Typhimurium, and Senftenberg in raw shelled almonds compared to conventional convective heating, and the effect of RF heating on quality by measuring changes in the color and degree of lipid oxidation. Agar-grown cells of three pathogens were inoculated onto the surface or inside of raw shelled almonds using surface inoculation or the vacuum perfusion method, respectively, and subjected to RF or conventional heating. RF heating for 40s achieved 3.7-, 6.0-, and 5.6-log reductions in surface-inoculated S. Enteritidis, S. Typhimurium, and S. Senftenberg, respectively, whereas the reduction of these pathogens following convective heating for 600s was 1.7, 2.5, and 3.7 log, respectively. RF heating reduced internally inoculated pathogens to below the detection limit (0.7 logCFU/g) after 30s. However, conventional convective heating did not attain comparable reductions even at the end of treatment (600s). Color values, peroxide values, and acid values of RF-treated (40-s treatment) almonds were not significantly (P>0.05) different from those of nontreated samples. These results suggest that RF heating can be applied to control internalized pathogens as well as surface-adhering pathogens in raw almonds without affecting product quality. Copyright © 2017. Published by Elsevier B.V.

  18. Does radio frequency radiation induce micronuclei frequency in exfoliated bladder cells of diabetic rats?

    Science.gov (United States)

    Gurbuz, N; Sirav, B; Kuzay, D; Ozer, C; Seyhan, N

    2015-07-01

    For many years there has been a discussion among both experts and the general public regarding the effects of radio frequency (RF) radiation on the human organism. The purpose of the present study was to evaluate the relationship of micronucleui (MN) frequency and RF radiation in exfoliated bladder cells of non-diabetic and diabetic rats. Three groups were used in the experiment: Group I (n=6): diabetic group without RF exposure; Group II (n=6): diabetic group exposed 2100 MHz RF radiation and Group III (n=6): control animals (non-diabetic group, no RF exposure). RF exposure in the experiment resulted in a whole body average SAR of 0.24 W/kg with an ERMS field of 17.5 V/m in non-thermal levels. Results showed that there was no statistically important differences between non-RF exposed diabetes group and control group; Group I and Group III (p>0.05). There was no statistically important differences between diabetes group and diabetes+RF exposed group (Group I and Group II) (p>0.05). RF exposure did not result in increased MN frequencies in exfoliated bladder cells of diabetic rats with respect to control animals (Group II and Group III), either and this result found no statistically important (p>0.05). This study suggested no possible genotoxic effects of RF radiation among human beings especially with chronic disorders, such as diabetes.

  19. Surface Modification of Direct-Current and Radio-Frequency Oxygen Plasma Treatments Enhance Cell Biocompatibility.

    Science.gov (United States)

    Chou, Wan-Ching; Wang, Rex C-C; Liu, Cheng; Yang, Chyun-Yu; Lee, Tzer-Min

    2017-10-25

    The sand-blasting and acid etching (SLA) method can fabricate a rough topography for mechanical fixation and long-term stability of titanium implant, but can not achieve early bone healing. This study used two kinds of plasma treatments (Direct-Current and Radio-Frequency plasma) to modify the SLA-treated surface. The modification of plasma treatments creates respective power range and different content functional OH groups. The results show that the plasma treatments do not change the micron scale topography, and plasma-treated specimens presented super hydrophilicity. The X-ray photoelectron spectroscopy (XPS)-examined result showed that the functional OH content of the RF plasma-treated group was higher than the control (SLA) and DC treatment groups. The biological responses (protein adsorption, cell attachment, cell proliferation, and differentiation) promoted after plasma treatments, and the cell responses, have correlated to the total content of amphoteric OH groups. The experimental results indicated that plasma treatments can create functional OH groups on SLA-treated specimens, and the RF plasma-treated SLA implant thus has potential for achievement of bone healing in early stage of implantation.

  20. Analysis of the Effect of Radio Frequency Interference on Repeat Track Airborne InSAR System

    Directory of Open Access Journals (Sweden)

    Ding Bin

    2012-03-01

    Full Text Available The SAR system operating at low frequency is susceptible to Radio Frequency Interference (RFI from television station, radio station, and some other civil electronic facilities. The presence of RFI degrades the SAR image quality, and obscures the targets in the scene. Furthermore, RFI can cause interferometric phase error in repeat track InSAR system. In order to analyze the effect of RFI on interferometric phase of InSAR, real measured RFI signal are added on cone simulated SAR echoes. The imaging and interferometric processing results of both the RFI-contaminated and raw data are given. The effect of real measured RFI signal on repeat track InSAR system is analyzed. Finally, the imaging and interferometric processing results of both with and without RFI suppressed of the P band airborne repeat track InSAR real data are presented, which demonstrates the efficiency of the RFI suppression method in terms of decreasing the interferometric phase errors caused by RFI.

  1. Verification of radio frequency pasteurization treatment for controlling Aspergillus parasiticus on corn grains.

    Science.gov (United States)

    Zheng, Ajuan; Zhang, Lihui; Wang, Shaojin

    2017-05-16

    Radio frequency (RF) heating has been proposed and tested to achieve a required anti-fungal efficacy on various food samples due to its advantage of deeper penetration depth and better heating uniformity. The purpose of this study was to validate applications of RF treatments for controlling Aspergillus parasiticus in corn while maintaining product quality. A pilot-scale, 27.12MHz, 6kW RF heating system together with hot air heating was used to rapidly pasteurize 3.0kg corn samples. Results showed that the pasteurizing effect of RF heating on Aspergillus parasiticus increased with increasing heating temperature and holding time, and RF heating at 70°C holding in hot air for at least 12min resulted in 5-6 log reduction of Aspergillus parasiticus in corn samples with the moisture content of 15.0% w.b. Furthermore, thermal resistance of Aspergillus parasiticus decreased with increasing moisture content (MC) of corn samples. Quality (MC, water activity - a w , protein, starch, ash, fat, fatty acid, color, electrical conductivity and germination rate) of RF treated corn met the required quality standard used in cereal industry. Therefore, RF treatments can provide an effective and rapid heating method to control Aspergillus parasiticus and maintain acceptable corn quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A synchronous hepatocellular carcinoma and renal cell carcinoma treated with radio-frequency ablation

    Directory of Open Access Journals (Sweden)

    Yoon Serk Lee

    2014-09-01

    Full Text Available Radio-frequency ablation (RFA is a curative treatment for hepatocellular carcinoma (HCC. Percutaneous RFA has been shown to be beneficial for patients with small renal cell carcinoma (RCC lacking indications for resection. We experienced the case of a 53-year-old male who had conditions that suggested HCC, RCC, and alcoholic liver cirrhosis. Abdominal contrast-enhanced computed tomography (CT and magnetic resonance image showed liver cirrhosis with 2.8 cm ill-defined mass in segment 2 of the liver and 1.9 cm hypervascular mass in the left kidney. These findings were compatible with the double primary cancers of HCC and RCC. Transarterial chemoembolization (TACE was performed to treat the HCC. After the TACE, a focal lipiodol uptake defect was noticed on a follow up CT images and loco-regional treatment was recommended. Therefore, we performed RFAs to treat HCC and RCC. There was no evidence of recurrence in the follow up image after 1 month.

  3. Upgrade and experimental results of radio frequency ion source for neutral beam injector

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yahong, E-mail: xieyh@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hu, Chundong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Jiang, Caichao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate school, University of Science and Technology of China, Hefei 230026 (China); Gu, Yuming; Xu, Yongjian; Chen, Shiyong; Liang, Lizhen; Liu, Zhimin; Xie, Yuanlai [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2017-01-15

    Highlights: • The RF ion source was developed in ASIPP for the first time. • The gas control was employed for the initial plasma production successfully. • The RF power was controlled for the stable plasma generation with high power. • Long pulse operation was tested and analyzed with 400 s. - Abstract: A radio frequency (RF) ion source was designed and developed for neutral beam injector in Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). Recently, the RF ion source was upgraded with new RF power generator (50 kW with frequency of 1 MHz), a new matching unit and the faraday shield with water cooling. Two new methods were used for the ion source tests on the test bed. The high pressure was used for the ignition of plasma and change to low pressure of 0.3 Pa to maintain the plasma. The RF plasma can be generated without the start filament successfully. In order to avoid the plasma oscillation with high power, the RF power was set to increase with two stages without change the matching unit. High power of 46 kW with pulse length of 22 s was achieved on the test bed and the plasma duration can be extended too.

  4. Spatiotemporal study of gas heating mechanisms in a radio-frequency electrothermal plasma micro-thruster

    Directory of Open Access Journals (Sweden)

    Amelia eGreig

    2015-10-01

    Full Text Available A spatiotemporal study of neutral gas temperature during the first 100 s of operation for a radio-frequency electrothermal plasma micro-thruster operating on nitrogen at 60 W and 1.5 Torr is performed to identify the heating mechanisms involved. Neutral gas temperature is estimated from rovibrational band fitting of the nitrogen second positive system. A set of baffles are used to restrict the optical image and separate the heating mechanisms occurring in the central bulk discharge region and near the thruster walls.For each spatial region there are three distinct gas heating mechanisms being fast heating from ion-neutral collisions with timescales of tens of milliseconds, intermediate heating with timescales of 10 s from ion bombardment on the inner thruster tube surface creating wall heating, and slow heating with timescales of 100 s from gradual warming of the entire thruster housing. The results are discussed in relation to optimising the thermal properties of future thruster designs.

  5. High temperature radio-frequency superconducting quantum interference device system for detection of magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pretzell, Alf

    2012-07-01

    This doctoral thesis was aimed at establishing a set-up with high-temperature superconductor (HTS) radio-frequency (rf) superconducting quantum interference device (SQUID) technology for the detection of magnetic nanoparticles and in particular for testing applications of magnetic nanoparticle immunoassays. It was part of the EU-project ''Biodiagnostics'' running from 2005 to 2008. The method of magnetic binding assays was developed as an alternative to other methods of concentration determination like enzyme linked immunosorbent assay (ELISA), or fluorescent immunoassay. The ELISA has sensitivities down to analyte-concentrations of pg/ml. Multiple incubation and washing steps have to be performed for these techniques, the analyte has to diffuse to the site of binding. The magnetic assay uses magnetic nanoparticles as markers for the substance to be detected. It is being explored by current research and shows similar sensitivity compared to ELISA but in contrast - does not need any washing and can be read out directly after binding - can be applied in solution with opaque media, e.g. blood or muddy water - additionally allows magnetic separation or concentration - in combination with small magnetoresistive or Hall sensors, allows detection of only a few particles or even single beads. For medical or environmental samples, maybe opaque and containing a multitude of substances, it would be advantageous to devise an instrument, which allows to be read out quickly and with high sensitivity. Due to the mentioned items the magnetic assay might be a possibility here.

  6. On-Board Particulate Filter Failure Prevention and Failure Diagnostics Using Radio Frequency Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sappok, Alex [Filter Sensing Technologies; Ragaller, Paul [Filter Sensing Technologies; Herman, Andrew [CTS Corporation; Bromberg, L. [Massachusetts Institute of Technology (MIT); Prikhodko, Vitaly Y [ORNL; Parks, II, James E [ORNL; Storey, John Morse [ORNL

    2017-01-01

    The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directly monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications. The testing included controlled engine dynamometer evaluations, which characterized soot slip from various filter failure modes, as well as on-road fleet vehicle tests. The results show a high sensitivity to detect conditions resulting in soot leakage from the particulate filter, as well as potential for direct detection of structural failures including internal cracks and melted regions within the filter media itself. Furthermore, the measurements demonstrate, for the first time, the capability to employ a direct and continuous monitor of particulate filter diagnostics to both prevent and detect potential failure conditions in the field.

  7. Analysis of heating, ventilation, and air conditioning ducts as a radio frequency communication channel

    Science.gov (United States)

    Nikitin, Pavel Viktorovich

    2002-01-01

    A typical HVAC duct system is a network of interconnected hollow metal pipes which can serve as waveguides and carry electromagnetic waves. This work presents an analysis of this system as a radio frequency communication channel. Two main parts of the analysis include channel modelling and antenna design. The propagation modelling approach used here is based on the waveguide mode theory and employs the transfer matrix method to describe propagation through various cascaded HVAC elements. This allows one to model the channel response in the frequency domain. Impulse response characteristics of the ducts are also analyzed in this work. The approximate transfer matrices of cylindrical straight sections, bends, and tapers are derived analytically. The transforming properties of cylindrical T-junctions are analyzed experimentally. Antenna designs in waveguides and free-space are different. In waveguides, mode excitation characteristics are important as well as the impedance match. The criteria for antenna design in waveguides are presented here. Antennas analyzed in this work are monopole antennas, dipole antennas, and antenna arrays. The developed model can predict both channel response and antenna characteristics for a given geometry and dimensions of the duct system and the antennas. The model is computationally efficient and can potentially be applied to duct systems of multiple story buildings. The accuracy of the model has been validated with extensive experimental measurements on real HVAC ducts.

  8. Study of Temperature Wave Propagation in Superfluid Helium Focusing on Radio-Frequency Cavity Cooling

    CERN Document Server

    Koettig, T; Avellino, S; Junginger, T; Bremer, J

    2015-01-01

    Oscillating Superleak Transducers (OSTs) can be used to localize quenches of superconducting radio-frequency cavities. Local hot spots at the cavity surface initiate temperature waves in the surrounding superfluid helium that acts as cooling fluid at typical temperatures in the range of 1.6 K to 2 K. The temperature wave is characterised by the properties of superfluid helium such as the second sound velocity. For high heat load densities second sound velocities greater than the standard literature values are observed. This fast propagation has been verified in dedicated small scale experiments. Resistors were used to simulate the quench spots under controlled conditions. The three dimensional propagation of second sound is linked to OST signals. The aim of this study is to improve the understanding of the OST signal especially the incident angle dependency. The characterised OSTs are used as a tool for quench localisation on a real size cavity. Their sensitivity as well as the time resolution was proven to b...

  9. Power efficiency improvements with the radio frequency H{sup −} ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kalvas, T., E-mail: taneli.kalvas@jyu.fi; Tarvainen, O.; Komppula, J.; Koivisto, H.; Tuunanen, J. [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland); Potkins, D.; Stewart, T.; Dehnel, M. [D-Pace, Inc., P.O. Box 201, Nelson, British Columbia V1L 5P9 (Canada)

    2016-02-15

    CW 13.56 MHz radio frequency-driven H{sup −} ion source is under development at the University of Jyväskylä for replacing an existing filament-driven ion source at the MCC30/15 cyclotron. Previously, production of 1 mA H{sup −} beam, which is the target intensity of the ion source, has been reported at 3 kW of RF power. The original ion source front plate with an adjustable electromagnet based filter field has been replaced with a new front plate with permanent magnet filter field. The new structure is more open and enables a higher flux of ro-vibrationally excited molecules towards the plasma electrode and provides a better control of the potential near the extraction due to a stronger separation of the main plasma from the plasma electrode. While the original system provided better control over the e{sup −}/H{sup −} ratio, the new configuration has led to a higher production efficiency of 1 mA H{sup −} at 1.75 kW RF power. The latest results and upgrade plans are presented.

  10. Solid-State Radio Frequency Plasma Heating Using a Nonlinear Transmission Line

    Science.gov (United States)

    Miller, Kenneth; Ziemba, Timothy; Prager, James; Slobodov, Ilia

    2015-11-01

    Radio Frequency heating systems are rarely used by the small-scale validation platform experiments due to the high cost and complexity of these systems, which typically require high power gyrotrons or klystrons, associated power supplies, waveguides and vacuum systems. The cost and complexity of these systems can potentially be reduced with a nonlinear transmission line (NLTL) based system. In the past, NLTLs have lacked a high voltage driver that could produce long duration high voltage pulses with fast rise times at high pulse repetition frequency. Eagle Harbor Technologies, Inc. (EHT) has created new high voltage nanosecond pulser, which combined with NLTL technology will produce a low-cost, fully solid-state architecture for the generation of the RF frequencies (0.5 to 10 GHz) and peak power levels (~ 10 MW) necessary for plasma heating and diagnostic systems for the validation platform experiments within the fusion science community. The proposed system does not require the use of vacuum tube technology, is inherently lower cost, and is more robust than traditional high power RF heating schemes. Design details and initial bench testing results for the new RF system will be presented. This work is supported under DOE Grant # DE-SC0013747.

  11. Reduction and degradation of amyloid aggregates by a pulsed radio-frequency cold atmospheric plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Bayliss, D L; Walsh, J L; Iza, F; Kong, M G [Department of Electronic and Electrical Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Shama, G [Department of Chemical Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)], E-mail: m.g.kong@lboro.ac.uk

    2009-11-15

    Surface-borne amyloid aggregates with mature fibrils are used as a non-infectious prion model to evaluate cold atmospheric plasmas (CAPs) as a prion inactivation strategy. Using a helium-oxygen CAP jet with pulsed radio-frequency (RF) excitation, amyloid aggregates deposited on freshly cleaved mica discs are reduced substantially leaving only a few spherical fragments of sub-micrometer sizes in areas directly treated by the CAP jet. Outside the light-emitting part of the CAP jet, plasma treatment results in a 'skeleton' of much reduced amyloid stacks with clear evidence of fibril fragmentation. Analysis of possible plasma species and the physical configuration of the jet-sample interaction suggests that the skeleton structures observed are unlikely to have arisen as a result of physical forces of detachment, but instead by progressive diffusion of oxidizing plasma species into porous amyloid aggregates. Composition of chemical bonds of this reduced amyloid sample is very different from that of intact amyloid aggregates. These suggest the possibility of on-site degradation by CAP treatment with little possibility of spreading contamination elsewhere , thus offering a new reaction chemistry route to protein infectivity control with desirable implications for the practical implementation of CAP-based sterilization systems.

  12. Finite element based contact analysis of radio frequency MEMs switch membrane surfaces

    Science.gov (United States)

    Liu, Jin-Ya; Chalivendra, Vijaya; Huang, Wenzhen

    2017-10-01

    Finite element simulations were performed to determine the contact behavior of radio frequency (RF) micro-electro-mechanical (MEM) switch contact surfaces under monotonic and cyclic loading conditions. Atomic force microscopy (AFM) was used to capture the topography of RF-MEM switch membranes and later they were analyzed for multi-scale regular as well as fractal structures. Frictionless, non-adhesive contact 3D finite element analysis was carried out at different length scales to investigate the contact behavior of the regular-fractal surface using an elasto-plastic material model. Dominant micro-scale regular patterns were found to significantly change the contact behavior. Contact areas mainly cluster around the regular pattern. The contribution from the fractal structure is not significant. Under cyclic loading conditions, plastic deformation in the 1st loading/unloading cycle smooth the surface. The subsequent repetitive loading/unloading cycles undergo elastic contact without changing the morphology of the contacting surfaces. The work is expected to shed light on the quality of the switch surface contact as well as the optimum design of RF MEM switch surfaces.

  13. Combinative exposure effect of radio frequency signals from CDMA mobile phones and aphidicolin on DNA integrity.

    Science.gov (United States)

    Tiwari, R; Lakshmi, N K; Surender, V; Rajesh, A D V; Bhargava, S C; Ahuja, Y R

    2008-01-01

    The aim of present study is to assess DNA integrity on the effect of exposure to a radio frequency (RF) signal from Code Division Multiple Access (CDMA) mobile phones. Whole blood samples from six healthy male individuals were exposed for RF signals from a CDMA mobile phone for 1 h. Alkaline comet assay was performed to assess the DNA damage. The combinative exposure effect of the RF signals and APC at two concentrations on DNA integrity was studied. DNA repair efficiency of the samples was also studied after 2 h of exposure. The RF signals and APC (0.2 microg/ml) alone or in synergism did not have any significant DNA damage as compared to sham exposed. However, univariate analysis showed that DNA damage was significantly different among combinative exposure of RF signals and APC at 0.2 microg/ml (p < 0.05) and at 2 microg/ml (p < 0.02). APC at 2 microg/ml concentration also showed significant damage levels (p < 0.05) when compared to sham exposed. DNA repair efficiency also varied in a significant way in combinative exposure sets (p < 0.05). From these results, it appears that the repair inhibitor APC enhances DNA breaks at 2 microg/ml concentration and that the damage is possibly repairable. Thus, it can be inferred that the in vitro exposure to RF signals induces reversible DNA damage in synergism with APC.

  14. Development of Ultra High Gradient and High Q{sub 0} Superconducting Radio Frequency Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Clemens, William A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Follkie, James E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Harris, Teena M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kushnick, Peter W. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Machie, Danny [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Martin, Robert E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, Ari D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Perry, Era A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Slack, Gary L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Williams, R. S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Adolphsen, C. [SLAC, Menlo Park, California, (United States); Li, Z. [SLAC, Menlo Park, California, (United States); Hao, J. K. [Peking University, Beijing (China); Li, Y. M. [Peking University, Beijing (China); Liu, K. X. [Peking University, Beijing (China)

    2013-06-01

    We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q{sub 0} superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q{sub 0} of 10{sup 10} at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q{sub 0} of 2-10{sup 10} at 2K.

  15. Development of a Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

    Science.gov (United States)

    Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

    2007-01-01

    The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and. control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for inter-spacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of medium, moving platforms, and radiated power. The Path Emulator for RF Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

  16. Lamb dip and infrared-radio frequency double resonance spectroscopy of 188OsO4

    Science.gov (United States)

    Ricci, L.; Pavone, F. S.; Prevedelli, M.; Zink, L. R.; Inguscio, M.; Scappini, F.; Sassi, M. P.

    1991-02-01

    The frequency of seven rovibrational transitions in the ν3 band, Q branch of 188OsO4 have been measured with high accuracy. The spectrometer used consists of two CO2 lasers [˜3 W on the 10R(0)], the first of which is stabilized on the 4.3 μm fluorescence Lamb dip of the CO2 and the second on the saturated absorption dip of the rovibrational transitions of 188OsO4. The OsO4 transition frequencies are obtained combining the known frequency of the first laser with the measured frequency of the beat note between the two laser beams. For the assignment of the transitions the recent Fourier transform analysis by Bobin et al. [J. Mol. Spectrosc. 122, 229 (1987)] was used. The access to the 10R(0) laser line has made it possible to investigate, for the first time, the Q branch of the ν3 band of OsO4 in a sub-Doppler regime. Furthermore, the tetrahedral fine structure in the ground and in the ν3 state has been analyzed using the infrared-radio frequency double resonance technique. The tetrahedral splitting constants, Dt for the ground state and Z3t for the ν3 state, have been calculated with higher accuracy than in previous works.

  17. Roll-to-Roll Screen Printed Radio Frequency Identification Transponder Antennas for Vehicle Tracking Systems

    Science.gov (United States)

    Zichner, Ralf; Baumann, Reinhard R.

    2013-05-01

    Vehicle tracking systems based on ultra high frequency (UHF) radio frequency identification (RFID) technology are already introduced to control the access to car parks and corporate premises. For this field of application so-called Windshield RFID transponder labels are used, which are applied to the inside of the windshield. State of the art for manufacturing these transponder antennas is the traditional lithography/etching approach. Furthermore the performance of these transponders is limited to a reading distance of approximately 5 m which results in car speed limit of 5 km/h for identification. However, to achieve improved performance compared to existing all-purpose transponders and a dramatic cost reduction, an optimized antenna design is needed which takes into account the special dielectric and in particular metallic car environment of the tag and an roll-to-roll (R2R) printing manufacturing process. In this paper we focus on the development of a customized UHF RFID transponder antenna design, which is adopted for vehicle geometry as well as R2R screen printing manufacturing processes.

  18. Design and Development of a Clinical Risk Management Tool Using Radio Frequency Identification (RFID).

    Science.gov (United States)

    Pourasghar, Faramarz; Tabrizi, Jafar Sadegh; Yarifard, Khadijeh

    2016-04-01

    Patient safety is one of the most important elements of quality of healthcare. It means preventing any harm to the patients during medical care process. This paper introduces a cost-effective tool in which the Radio Frequency Identification (RFID) technology is used to identify medical errors in hospital. The proposed clinical error management system (CEMS) is consisted of a reader device, a transfer/receiver device, a database and managing software. The reader device works using radio waves and is wireless. The reader sends and receives data to/from the database via the transfer/receiver device which is connected to the computer via USB port. The database contains data about patients' medication orders. The CEMS has the ability to identify the clinical errors before they occur and then warns the care-giver with voice and visual messages to prevent the error. This device reduces the errors and thus improves the patient safety. A new tool including software and hardware was developed in this study. Application of this tool in clinical settings can help the nurses prevent medical errors. It can also be a useful tool for clinical risk management. Using this device can improve the patient safety to a considerable extent and thus improve the quality of healthcare.

  19. Battery-free radio frequency identification (RFID) sensors for food quality and safety.

    Science.gov (United States)

    Potyrailo, Radislav A; Nagraj, Nandini; Tang, Zhexiong; Mondello, Frank J; Surman, Cheryl; Morris, William

    2012-09-05

    Market demands for new sensors for food quality and safety stimulate the development of new sensing technologies that can provide an unobtrusive sensor form, battery-free operation, and minimal sensor cost. Intelligent labeling of food products to indicate and report their freshness and other conditions is one important possible application of such new sensors. This study applied passive (battery-free) radio frequency identification (RFID) sensors for the highly sensitive and selective detection of food freshness and bacterial growth. In these sensors, the electric field generated in the RFID sensor antenna extends from the plane of the RFID sensor and is affected by the ambient environment, providing the opportunity for sensing. This environment may be in the form of a food sample within the electric field of the sensing region or a sensing film deposited onto the sensor antenna. Examples of applications include monitoring of milk freshness, fish freshness, and bacterial growth in a solution. Unlike other food freshness monitoring approaches that require a thin film battery for operation of an RFID sensor and fabrication of custom-made sensors, the passive RFID sensing approach developed here combines the advantages of both battery-free and cost-effective sensor design and offers response selectivity that is impossible to achieve with other individual sensors.

  20. Repetitive cleaning of a stainless steel first mirror using radio frequency plasma

    Science.gov (United States)

    Peng, Jiao; Yan, Rong; Ding, Rui; Chen, Junling; Zhu, Dahuan; Zhang, Zengming

    2017-10-01

    First mirrors (FMs) are crucial components of optical diagnostic systems in present-day tokamaks and future fusion reactors. Their lifetimes should be extremely limited due to their proximity to burning plasma, greatly influencing the safe operation of corresponding diagnostics. Repetitive cleaning is expected to provide a solution to the frequent replacement of contaminated FMs, thus prolonging their lifetimes. Three repetitive cleaning cycles using radio frequency plasma were applied to stainless steel (SS) FM samples, to evaluate the change of the mirrors’ optical properties and morphology during each cycle. Amorphous carbon films were deposited on mirror surfaces under identical conditions in three cycles. In three cycles with identical cleaning parameters, the total reflectivity was restored at up to 95%. Nevertheless, with successive cleaning cycles, the FM surfaces gradually appeared to roughen due to damage to the grain boundaries. Correspondingly, the diffuse reflectivity increased from a few percent to 20% and 27% after the second and third cycles. After optimizing the cleaning parameters of the second and third cycles, the roughness showed a significant decrease, and simultaneously the increase of diffuse reflectivity was remarkably improved.

  1. Surface Modification of Direct-Current and Radio-Frequency Oxygen Plasma Treatments Enhance Cell Biocompatibility

    Directory of Open Access Journals (Sweden)

    Wan-Ching Chou

    2017-10-01

    Full Text Available The sand-blasting and acid etching (SLA method can fabricate a rough topography for mechanical fixation and long-term stability of titanium implant, but can not achieve early bone healing. This study used two kinds of plasma treatments (Direct-Current and Radio-Frequency plasma to modify the SLA-treated surface. The modification of plasma treatments creates respective power range and different content functional OH groups. The results show that the plasma treatments do not change the micron scale topography, and plasma-treated specimens presented super hydrophilicity. The X-ray photoelectron spectroscopy (XPS-examined result showed that the functional OH content of the RF plasma-treated group was higher than the control (SLA and DC treatment groups. The biological responses (protein adsorption, cell attachment, cell proliferation, and differentiation promoted after plasma treatments, and the cell responses, have correlated to the total content of amphoteric OH groups. The experimental results indicated that plasma treatments can create functional OH groups on SLA-treated specimens, and the RF plasma-treated SLA implant thus has potential for achievement of bone healing in early stage of implantation.

  2. Ultraminiaturized photovoltaic and radio frequency powered optoelectronic systems for wireless optogenetics

    Science.gov (United States)

    Park, Sung Il; Shin, Gunchul; Banks, Anthony; McCall, Jordan G.; Siuda, Edward R.; Schmidt, Martin J.; Chung, Ha Uk; Nim Noh, Kyung; Guo-Han Mun, Jonathan; Rhodes, Justin; Bruchas, Michael R.; Rogers, John A.

    2015-10-01

    Objective. Wireless control and power harvesting systems that operate injectable, cellular-scale optoelectronic components provide important demonstrated capabilities in neuromodulatory techniques such as optogenetics. Here, we report a radio frequency (RF) control/harvesting device that offers dramatically reduced size, decreased weight and improved efficiency compared to previously reported technologies. Combined use of this platform with ultrathin, multijunction, high efficiency solar cells allows for hundred-fold reduction of transmitted RF power, which greatly enhances the wireless coverage. Approach. Fabrication involves separate construction of the harvester and the injectable µ-ILEDs. To test whether the presence of the implantable device alters behavior, we implanted one group of wild type mice and compared sociability behavior to unaltered controls. Social interaction experiments followed protocols defined by Silverman et al. with minor modifications. Main results. The results presented here demonstrate that miniaturized RF harvesters, and RF control strategies with photovoltaic harvesters can, when combined with injectable µ-ILEDs, offer versatile capabilities in optogenetics. Experimental and modeling studies establish a range of effective operating conditions for these two approaches. Optogenetics studies with social groups of mice demonstrate the utility of these systems. Significance. The addition of miniaturized, high performance photovoltaic cells significantly expands the operating range and reduces the required RF power. The platform can offer capabilities to modulate signaling path in the brain region of freely-behaving animals. These suggest its potential for widespread use in neuroscience.

  3. Structure and dielectric properties in the radio frequency range of polymer composites based on vanadium dioxide

    Directory of Open Access Journals (Sweden)

    Kolbunov V.R.

    2015-06-01

    Full Text Available Polymer composites with active fillers are recently considered to be promising materials for the design of new functional devices with controllable properties and are intensively investigated. Dielectric studies are one of the most effective methods for studying structural features and mechanisms of conductivity formation for this type of two-component systems. The paper presents research results of the dielectric characteristics in the range of radio frequency of 50 kHz — 10 MHz and temperature range of 30—60°C of polyethylene composites of vanadium dioxide with different volume fractions of filler. Two dispersion areas were found: a high-frequency area caused by the Maxwell charge separation on the boundaries of the polyethylene matrix — conductive filler of VI2 crystallites, and a low frequency area associated with the presence of the transition layer at this boundary. The relative permittivity of the composite has a tendency to a decrease in absolute value with increasing temperature. The analysis of the low-frequency dependence of the dielectric constant of the value of the filler’s volume fraction revealed that the investigated composite belongs to two-component statistical mixtures with a transition layer between the components.

  4. Improved Radio Frequency Identification Indoor Localization Method via Radial Basis Function Neural Network

    Directory of Open Access Journals (Sweden)

    Dongliang Guo

    2014-01-01

    Full Text Available Indoor localization technique has received much attention in recent years. Many techniques have been developed to solve the problem. Among the recent proposed methods, radio frequency identification (RFID indoor localization technology has the advantages of low-cost, noncontact, non-line-of-sight, and high precision. This paper proposed two radial basis function (RBF neural network based indoor localization methods. The RBF neural networks are trained to learn the mapping relationship between received signal strength indication values and position of objects. Traditional method used the received signal strength directly as the input of neural network; we added another input channel by taking the difference of the received signal strength, thus improving the reliability and precision of positioning. Fuzzy clustering is used to determine the center of radial basis function. In order to reduce the impact of signal fading due to non-line-of-sight and multipath transmission in indoor environment, we improved the Gaussian filter to process received signal strength values. The experimental results show that the proposed method outperforms the existing methods as well as improves the reliability and precision of the RFID indoor positioning system.

  5. Global particle in cell simulation of radio frequency waves in tokamak ∖fs20

    Science.gov (United States)

    Kuley, Animesh; Lin, Z.; Bao, J.; Lau, C.; Sun, G. Y.

    2016-10-01

    We are looking into a new nonlinear kinetic simulation model to study the radio frequency heating and current drive of fusion plasmas using toroidal code GTC. In this model ions are considered as fully kinetic (FK) particles using Vlasov equation and the electrons are treated as drift kinetic (DK) particles using drift kinetic equation. We have benchmarked this numerical model to verify the linear physics of normal modes, conversion of slow and fast waves and its propagation in the core region of the tokamak using the Boozer coordinates. In the nonlinear simulation of ion Bernstein wave (IBW) in a tokamak, parametric decay instability (PDI) is observed where a large amplitude pump wave decays into an IBW sideband and an ion cyclotron quasi-mode (ICQM). The ICQM induces an ion perpendicular heating, with a heating rate proportional to the pump wave intensity. Finally, in the electromagnetic LH simulation, nonlinear wave trapping of electrons is verified and plasma current is nonlinearly driven. Presently we are working on the development of new PIC simulation model using cylindrical coordinates to address the RF wave propagation from the edge of the tokamak to the core region and the parametric instabilities associated with this RF waves. We have verified the cyclotron integrator using Boris push method.

  6. 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.

  7. Role of thermal resistance on the performance of superconducting radio frequency cavities

    Science.gov (United States)

    Dhakal, Pashupati; Ciovati, Gianluigi; Myneni, Ganapati Rao

    2017-03-01

    Thermal stability is an important parameter for the operation of the superconducting radio frequency (SRF) cavities used in particle accelerators. The rf power dissipated on the inner surface of the cavities is conducted to the helium bath cooling the outer cavity surface and the equilibrium temperature of the inner surface depends on the thermal resistance. In this manuscript, we present the results of direct measurements of thermal resistance on 1.3 GHz single cell SRF cavities made from high purity large-grain and fine-grain niobium as well as their rf performance for different treatments applied to outer cavity surface in order to investigate the role of the Kapitza resistance to the overall thermal resistance and to the SRF cavity performance. The results show no significant impact of the thermal resistance to the SRF cavity performance after chemical polishing, mechanical polishing or anodization of the outer cavity surface. Temperature maps taken during the rf test show nonuniform heating of the surface at medium rf fields. Calculations of Q0(Bp) curves using the thermal feedback model show good agreement with experimental data at 2 and 1.8 K when a pair-braking term is included in the calculation of the Bardeen-Cooper-Schrieffer surface resistance. These results indicate local intrinsic nonlinearities of the surface resistance, rather than purely thermal effects, to be the main cause for the observed field dependence of Q0(Bp) .

  8. 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

  9. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Binder-free highly conductive graphene laminate for low cost printed radio frequency applications

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xianjun; Leng, Ting; Zhang, Xiao; Hu, Zhirun, E-mail: Z.Hu@manchester.ac.uk [School of Electrical and Electronic Engineering, University of Manchester, Manchester (United Kingdom); Chen, Jia Cing; Chang, Kuo Hsin [BGT Materials Limited, Photon Science Institute, University of Manchester, Manchester M13 9PL (United Kingdom); Geim, Andre K. [Manchester Centre for Mesoscience and Nanotechnology, University of Manchester, Manchester (United Kingdom); Novoselov, Kostya S. [School of Physics and Astronomy, University of Manchester, Manchester (United Kingdom)

    2015-05-18

    In this paper, we demonstrate realization of printable radio frequency identification (RFID) antenna by low temperature processing of graphene ink. The required ultra-low resistance is achieved by rolling compression of binder-free graphene laminate. With compression, the conductivity of graphene laminate is increased by more than 50 times compared to that of as-deposited one. Graphene laminate with conductivity of 4.3 × 10{sup 4 }S/m and sheet resistance of 3.8 Ω/sq (with thickness of 6 μm) is presented. Moreover, the formation of graphene laminate from graphene ink reported here is simple and can be carried out in low temperature (100 °C), significantly reducing the fabrication costs. A dipole antenna based on the highly conductive graphene laminate is further patterned and printed on a normal paper to investigate its RF properties. The performance of the graphene laminate antenna is experimentally measured. The measurement results reveal that graphene laminate antenna can provide practically acceptable return loss, gain, bandwidth, and radiation patterns, making it ideal for low cost printed RF applications, such as RFID tags and wearable wireless sensor networks.

  11. How Radio Frequency Identification Improves Pharmaceutical Industry: A Comprehensive Review Literature

    Directory of Open Access Journals (Sweden)

    Roxana Sharifian

    2016-05-01

    Full Text Available According to the vital role of pharmaceutical industry in health care system, pharmaceutical supply chain security, standard production and distribution of the pharmaceutical products are of great importance for pharmaceutical companies. Therefore, applying technology, especially Radio Frequency Identification (RFID, is essential to achieve these goals. Moreover, due to the importance of security in production and distribution and also the quality of pharmaceutical products, international pharmaceutical Institutes such as Food and Drug Administration (FDA and huge pharmaceutical companies apply RFID to increase their success and improve their efficiency and effectiveness. The present study explains the concept of RFID, its application and importance in pharmaceutical industry, and its role in struggling against counterfeit medicines in addition to presenting a framework of RFID in struggling against counterfeit medicines. It is discussed that RFID has various applications in pharmaceutical industry such as inventory and property management system, access control and machines’ performances, producing sterile pharmaceutical products, anti-thieving mechanism, preventing medicines’ diversion.Counterfeit medicines and recognition of counterfeit medicines. As a conclusion RFID can be suggested to make the pharmaceutical industry and health system smart. Therefore, it is suggested to establish this technology in pharmaceutical supply chain by the use of Information Technology and create a team of related specialists in order to successful application of this technology and gain the positive related results.

  12. 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.

  13. Is local stiffness, as measured by radio frequency, more sensitive than intima-media thickness?

    Science.gov (United States)

    Novo, G; Di Miceli, R; Novo, S

    2013-12-01

    The aim of our study was to explore the changes in common carotid arterial intima-media thickness (CCA IMT) and local arterial stiffness to evaluate, non-invasively, early vascular disease in patients with cardiovascular (CV) risk factors and "normal" carotid IMT (local stiffness with Quality Arterial Stiffness technology, based on Radio frequency signal (RFQAS-ESAOTE, Italy). CCA distensibility coefficient (DC), compliance coefficient (CC), pulse wave velocity (PWV) and β parameter were measured in patients, with and without traditional cardiovascular risk factors. 25 subjects with risk factors (mean age 49±13) were compared with 25 controls (mean age 36±12). We did not find any significant differences in the IMT measurement between subjects with CV risk factors compared to controls (0.530±0.99 mm vs. 0.626±0.127 mm; P=5.68). The mean DC (0.030±0.014 1/kPa vs. 0.0221±0.016 1/kPa; P6.05 m/s better identified, among patients with IMT <0.9 mm, those with cardiovascular risk factors (sensitivity 82.0% specificity 62.0%; AUC 0.73). Increased stiffness is a result of change both in quantity and quality of the arterial wall. Arterial functional changes and distention alterations may herald the onset of vascular disease before manifestation of symptoms or detection of preclinical atherosclerotic lesions.

  14. An expression for the frequency spectrum of a digital radio frequency memory signal

    Science.gov (United States)

    Berger, Scott D.; Meer, David E.

    A digital radio-frequency memory (DRFM) is an electronic countermeasures device that samples and quantizes (analog to digital conversion) an incoming radar signal and produces (digital to analog conversion) a jamming signal from the sampled radar signal. An equation for the frequency spectrum of a signal produced by a DRFM is derived. The derivation of the equation assumes that the incoming radar signal has a finite duration and a single frequency, that the ratio of the radar frequency (after heterodyning to baseband) to the sampling frequency is rational, and that the components used in the DRFM are ideal. The quantization of the sampled values causes harmonics in the DRFM signal. The magnitude of the harmonics is a major concern to the designers of DRFM systems, and an equation for predicting the magnitude of the harmonics is necessary for performance analysis. This equation provides an easy and fast method for determining how the magnitude of the harmonics is affected by the number of quantization levels (bits) in the analog-to-digital converter.

  15. Cyber security with radio frequency interferences mitigation study for satellite systems

    Science.gov (United States)

    Wang, Gang; Wei, Sixiao; Chen, Genshe; Tian, Xin; Shen, Dan; Pham, Khanh; Nguyen, Tien M.; Blasch, Erik

    2016-05-01

    Satellite systems including the Global Navigation Satellite System (GNSS) and the satellite communications (SATCOM) system provide great convenience and utility to human life including emergency response, wide area efficient communications, and effective transportation. Elements of satellite systems incorporate technologies such as navigation with the global positioning system (GPS), satellite digital video broadcasting, and information transmission with a very small aperture terminal (VSAT), etc. The satellite systems importance is growing in prominence with end users' requirement for globally high data rate transmissions; the cost reduction of launching satellites; development of smaller sized satellites including cubesat, nanosat, picosat, and femtosat; and integrating internet services with satellite networks. However, with the promising benefits, challenges remain to fully develop secure and robust satellite systems with pervasive computing and communications. In this paper, we investigate both cyber security and radio frequency (RF) interferences mitigation for satellite systems, and demonstrate that they are not isolated. The action space for both cyber security and RF interferences are firstly summarized for satellite systems, based on which the mitigation schemes for both cyber security and RF interferences are given. A multi-layered satellite systems structure is provided with cross-layer design considering multi-path routing and channel coding, to provide great security and diversity gains for secure and robust satellite systems.

  16. Spin Biochemistry Modulates Reactive Oxygen Species (ROS) Production by Radio Frequency Magnetic Fields

    Science.gov (United States)

    Usselman, Robert J.; Hill, Iain; Singel, David J.; Martino, Carlos F.

    2014-01-01

    The effects of weak magnetic fields on the biological production of reactive oxygen species (ROS) from intracellular superoxide (O2•−) and extracellular hydrogen peroxide (H2O2) were investigated in vitro with rat pulmonary arterial smooth muscle cells (rPASMC). A decrease in O2•− and an increase in H2O2 concentrations were observed in the presence of a 7 MHz radio frequency (RF) at 10 μTRMS and static 45 μT magnetic fields. We propose that O2•− and H2O2 production in some metabolic processes occur through singlet-triplet modulation of semiquinone flavin (FADH•) enzymes and O2•− spin-correlated radical pairs. Spin-radical pair products are modulated by the 7 MHz RF magnetic fields that presumably decouple flavin hyperfine interactions during spin coherence. RF flavin hyperfine decoupling results in an increase of H2O2 singlet state products, which creates cellular oxidative stress and acts as a secondary messenger that affects cellular proliferation. This study demonstrates the interplay between O2•− and H2O2 production when influenced by RF magnetic fields and underscores the subtle effects of low-frequency magnetic fields on oxidative metabolism, ROS signaling, and cellular growth. PMID:24681944

  17. Role of Radio Frequency and Microwaves in Magnetic Fusion Plasma Research

    Directory of Open Access Journals (Sweden)

    Hyeon K. Park

    2017-10-01

    Full Text Available The role of electromagnetic (EM waves in magnetic fusion plasma—ranging from radio frequency (RF to microwaves—has been extremely important, and understanding of EM wave propagation and related technology in this field has significantly advanced magnetic fusion plasma research. Auxiliary heating and current drive systems, aided by various forms of high-power RF and microwave sources, have contributed to achieving the required steady-state operation of plasmas with high temperatures (i.e., up to approximately 10 keV; 1 eV = 10000 K that are suitable for future fusion reactors. Here, various resonance values and cut-off characteristics of wave propagation in plasmas with a nonuniform magnetic field are used to optimize the efficiency of heating and current drive systems. In diagnostic applications, passive emissions and active sources in this frequency range are used to measure plasma parameters and dynamics; in particular, measurements of electron cyclotron emissions (ECEs provide profile information regarding electron temperature. Recent developments in state-of-the-art 2D microwave imaging systems that measure fluctuations in electron temperature and density are largely based on ECE. The scattering process, phase delays, reflection/diffraction, and the polarization of actively launched EM waves provide us with the physics of magnetohydrodynamic instabilities and transport physics.

  18. Radio frequency heating induced edge plasma convection: self-consistent simulations and experiments on ASDEX Upgrade

    Science.gov (United States)

    Zhang, W.; Tierens, W.; Noterdaeme, J.-M.; Bobkov, V.; Aguiam, D.; Coster, D.; Fuenfgelder, H.; Jacquot, J.; Ochoukov, R.; Silva, A.; Colas, L.; Křivská, A.; the ASDEX Upgrade Team; the MST1 Team

    2017-11-01

    Plasma heating with waves in the ion cyclotron range of frequency (ICRF) affects the edge plasma and the edge plasma affects the ICRF heating. In simulations, these nonlinear ICRF—edge plasma interactions have been self-consistently simulated by running the EMC3-EIRENE, RAPLICASOL and SSWICH codes in an iterative way on ASDEX Upgrade for the first time. In experiments, the edge plasma convection induced by powered 3-strap antennas is measured with the antenna embedded reflectometers for the first time. Both the simulation and experimental results indicate that the ICRF induced convective cells are most significant on the top and bottom of the antennas; the edge plasma convection induced by 3-strap antennas in optimized antenna feeding configuration (dipole phasing, power ratio between the center and outer straps ~1.5) is smallest among the studied cases. The simulation results also suggest that compared to the 2-strap antennas, the 3-strap antennas can significantly reduce the plasma convection associated with the radio-frequency sheaths, even with unfavorable power balance between the straps in dipole phasing.

  19. Phase stabilized downlink transmission for wideband radio frequency signal via optical fiber link.

    Science.gov (United States)

    Zhang, Anxu; Dai, Yitang; Yin, Feifei; Ren, Tianpeng; Xu, Kun; Li, Jianqiang; Tang, Geshi

    2014-09-08

    In this paper, we propose and demonstrate a phase stabilized wideband downlink transmission scheme, which directly transmits the received radio frequency (RF) signals from remote antennas to central station. A reference RF tone is round-trip transferred between the central station and remote end to obtain the delay variation caused by the fiber link. The delay variation is then used to alter a tunable laser. Since optical carriers with different wavelengths propagate at different velocities in fiber, a tunable optical delay line is realized to cancel the delay variation of the fiber link. The tunable delay range is in proportion to the length of the fiber link, which means a very long delivery distance can be expected. Experimentally, a RF signal at frequency of 2.50 GHz has been downlink transferred through a 45 km fiber link, with stability of 3.3 x 10⁻¹³ at 1 s and 7.5 x 10⁻¹⁷ at 10⁴s.

  20. Flexible Gallium Nitride for High-Performance, Strainable Radio-Frequency Devices.

    Science.gov (United States)

    Glavin, Nicholas R; Chabak, Kelson D; Heller, Eric R; Moore, Elizabeth A; Prusnick, Timothy A; Maruyama, Benji; Walker, Dennis E; Dorsey, Donald L; Paduano, Qing; Snure, Michael

    2017-11-02

    Flexible gallium nitride (GaN) thin films can enable future strainable and conformal devices for transmission of radio-frequency (RF) signals over large distances for more efficient wireless communication. For the first time, strainable high-frequency RF GaN devices are demonstrated, whose exceptional performance is enabled by epitaxial growth on 2D boron nitride for chemical-free transfer to a soft, flexible substrate. The AlGaN/GaN heterostructures transferred to flexible substrates are uniaxially strained up to 0.85% and reveal near state-of-the-art values for electrical performance, with electron mobility exceeding 2000 cm(2) V(-1) s(-1) and sheet carrier density above 1.07 × 10(13) cm(-2) . The influence of strain on the RF performance of flexible GaN high-electron-mobility transistor (HEMT) devices is evaluated, demonstrating cutoff frequencies and maximum oscillation frequencies greater than 42 and 74 GHz, respectively, at up to 0.43% strain, representing a significant advancement toward conformal, highly integrated electronic materials for RF applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.