WorldWideScience

Sample records for auxiliary radiofrequency heating

  1. Auxiliary radiofrequency heating of tokamaks, Task 3

    International Nuclear Information System (INIS)

    Scharer, J.E.

    1991-07-01

    The research performed under this grant during the past three years has been concentrated on the following several key tokamak ICRF (Ion Cyclotron Range of Frequencies) coupling and heating issues: efficient coupling during the L- to H-mode transition by analysis and computer simulation of ICRF antennas edge plasma profiles; analysis of both dielectric-filled waveguide and coil ICRF antenna coupling to plasma edge profiles; benchmarking the codes to compare with current JET, D-IIID and ASDEX experimental results; ICRF full-wave field solutions, power conservation and heating analyses; and the effects of fusion alpha particle or ion tail populations on the ICRF absorption. Research progress, publications, and conference and workshop presentations are summarized in this report. 15 refs

  2. Fusion Plasma Theory Grant: Task 3, Auxiliary Radiofrequency Heating of Tokamaks

    International Nuclear Information System (INIS)

    Scharer, J.E.

    1993-06-01

    The research performed under this grant during the past year has been concentrated on the following several key tokamak ICRF (Ion Cyclotron Range of Frequencies) coupling, heating and current drive issues. We have made progress in developing a ''3-D'' cavity backed antenna array code to examine ICRF coupling to general plasma edge profiles. The effects of the finite antenna length and feeders as well as Faraday shield blade angle are being examined. We are also developing an analysis to examine large k perpendicular ρ gyroradius interaction between alpha or beam particles and ICRF waves. This topic has important applications in the areas of ICRF heating for deuterium-tritium fusion plasmas, TAE modes, ash removal and minority ion current drive. Research progress, publications, and conference and workshop presentations are summarized in this report

  3. Radiofrequency plasma heating: proceedings

    International Nuclear Information System (INIS)

    Swenson, D.G.

    1985-01-01

    The conference proceedings include sessions on Alfven Wave Heating, ICRF Heating and Current Drive, Lower Hybrid Heating and Current Drive, and ECRF Heating. Questions of confinement, diagnostics, instabilities and technology are considered. Individual papers are cataloged separately

  4. Nuclear reactor auxiliary heat removal system

    International Nuclear Information System (INIS)

    Thompson, R.E.; Pierce, B.L.

    1977-01-01

    An auxiliary heat removal system to remove residual heat from gas-cooled nuclear reactors is described. The reactor coolant is expanded through a turbine, cooled in a heat exchanger and compressed by a compressor before reentering the reactor coolant. The turbine powers both the compressor and the pump which pumps a second fluid through the heat exchanger to cool the reactor coolant. A pneumatic starter is utilized to start the turbine, thereby making the auxiliary heat removal system independent of external power sources

  5. Transport in Auxiliary Heated NSTX Discharges

    International Nuclear Information System (INIS)

    LeBlanc, B.P.; Bell, M.G.; Bell, R.E.; Bitte, M.L.; Bourdelle, C.; Gates, D.A.; Kaye, S.M.; Maingi, R.; Menard, J.E.; Mueller, D.; Ono, M.; Paul, S.F.; Redi, M.H.; Roquemore, A.L.; Rosenberg, A.; Sabbagh, S.A.; Stutman, D.; Synakowski, E.J.; Soukhanovskii, V.A.; Wilson, J.R.

    2003-01-01

    The NSTX spherical torus (ST) provides a unique platform to investigate magnetic confinement in auxiliary-heated plasmas at low aspect ratio. Auxiliary power is routinely coupled to ohmically heated plasmas by deuterium neutral-beam injection (NBI) and by high-harmonic fast waves (HHFW) launch. While theory predicts both techniques to preferentially heat electrons, experiment reveals the electron temperature is greater than the ion temperature during HHFW, but the electron temperature is less than the ion temperature during NBI. In the following we present the experimental data and the results of transport analyses

  6. Auxiliary Heat Exchanger Flow Distribution Test

    International Nuclear Information System (INIS)

    Kaufman, J.S.; Bressler, M.M.

    1983-01-01

    The Auxiliary Heat Exchanger Flow Distribution Test was the first part of a test program to develop a water-cooled (tube-side), compact heat exchanger for removing heat from the circulating gas in a high-temperature gas-cooled reactor (HTGR). Measurements of velocity and pressure were made with various shell side inlet and outlet configurations. A flow configuration was developed which provides acceptable velocity distribution throughout the heat exchanger without adding excessive pressure drop

  7. Model predictions for auxiliary heating in spheromaks

    International Nuclear Information System (INIS)

    Fauler, T.K.; Khua, D.D.

    1997-01-01

    Calculations are presented of the plasma temperature waited for under auxiliary heating in spheromaks. A model, ensuring good agreement of earlier experiments with joule heating results, is used. The model includes heat losses due to magnetic fluctuations and shows that the plasma temperatures of the kilo-electron-volt order may be achieved in a small device with the radius of 0.3 m only

  8. Auxiliary plasma heating and fueling models for use in particle simulation codes

    International Nuclear Information System (INIS)

    Procassini, R.J.; Cohen, B.I.

    1989-01-01

    Computational models of a radiofrequency (RF) heating system and neutral-beam injector are presented. These physics packages, when incorporated into a particle simulation code allow one to simulate the auxiliary heating and fueling of fusion plasmas. The RF-heating package is based upon a quasilinear diffusion equation which describes the slow evolution of the heated particle distribution. The neutral-beam injector package models the charge exchange and impact ionization processes which transfer energy and particles from the beam to the background plasma. Particle simulations of an RF-heated and a neutral-beam-heated simple-mirror plasma are presented. 8 refs., 5 figs

  9. Progress on radio frequency auxiliary heating system designs in ITER

    International Nuclear Information System (INIS)

    Makowski, M.; Bosia, G.; Elio, F.

    1996-09-01

    ITER will require over 100 MW of auxiliary power for heating, on- and off-axis current drive, accessing the H-mode, and plasma shut-down. The Electron Cyclotron Range of Frequencies (ECRF) and Ion Cyclotron Range of Frequencies (ICRF) are two forms of Radio Frequency (RF) auxiliary power being developed for these applications. Design concepts for both the ECRF and ICRF systems are presented, key features and critical design issues are discussed, and projected performances outlined

  10. Direction of Impurity Pinch and Auxiliary Heating in Tokamak Plasmas

    International Nuclear Information System (INIS)

    Angioni, C.; Peeters, A.G.

    2006-01-01

    A mechanism of particle pinch for trace impurities in tokamak plasmas, arising from the effect of parallel velocity fluctuations in the presence of a turbulent electrostatic potential, is identified analytically by means of a reduced fluid model and verified numerically with a gyrokinetic code for the first time. The direction of such a pinch reverses as a function of the direction of rotation of the turbulence in agreement with the impurity pinch reversal observed in some experiments when moving from dominant auxiliary ion heating to dominant auxiliary electron heating

  11. Radiofrequency Heating Pathways for Gold Nanoparticles

    Science.gov (United States)

    Collins, C. B.; McCoy, R. S.; Ackerson, B. J.; Collins, G. J.

    2015-01-01

    This feature article reviews the thermal dissipation of nanoscopic gold under radiofrequency (RF) irradiation. It also presents previously unpublished data addressing obscure aspects of this phenomenon. While applications in biology motivated initial investigation of RF heating of gold nanoparticles, recent controversy concerning whether thermal effects can be attributed to nanoscopic gold highlight the need to understand the involved mechanism or mechanisms of heating. Both the nature of the particle and the nature of the RF field influence heating. Aspects of nanoparticle chemistry and physics, including the hydrodynamic diameter of the particle, the oxidation state and related magnetism of the core, and the chemical nature of the ligand shell may all strongly influence to what extent a nanoparticle heats in an RF field. Aspects of RF include: power, frequency and antenna designs that emphasize relative strength of magnetic or electric fields, and also influence the extent to which a gold nanoparticle heats in RF. These nanoparticle and RF properties are analysed in the context of three heating mechanisms proposed to explain gold nanoparticle heating in an RF field. This article also makes a critical analysis of the existing literature in the context of the nanoparticle preparations, RF structure, and suggested mechanisms in previously reported experiments. PMID:24962620

  12. Specifying the auxiliary heating system on TFCX

    International Nuclear Information System (INIS)

    Metzler, D.H.

    1983-01-01

    This paper reviews the status of heating systems for the TFCX-S (all superconducting coil) and TFCX-H (hybrid coil) options. Three systems were defined; preheating (electron), current drive, and bulk (ion) heating. Application of systems engineering techniques facilitated fruitful discussions of requirements and their impact on equipment between physicists and engineers. A low-cost, flexible combination of systems allows plasma experiments using all rf startup and current drive

  13. Plasma auxiliary heating and current drive

    International Nuclear Information System (INIS)

    1999-01-01

    Heating and current drive systems must fulfil several roles in ITER operating scenarios: heating through the H-mode transition and to ignition; plasma burn control; current drive and current profile control in steady state scenarios; and control of MHD instabilities. They must also perform ancillary functions, such as assisting plasma start-up and wall conditioning. It is recognized that no one system can satisfy all of these requirements with the degree of flexibility that ITER will require. Four heating and current drive systems are therefore under consideration for ITER: electron cyclotron waves at a principal frequency of 170 GHz; fast waves operating in the range 40-70 MHz (ion cyclotron waves); lower hybrid waves at 5 GHz; and neutral beam injection using negative ion beam technology for operation at 1 MeV energy. It is likely that several of these systems will be employed in parallel. The systems have been chosen on the basis of the maturity of physics understanding and operating experience in current experiments and on the feasibility of applying the relevant technology to ITER. Here, the fundamental physics describing the interaction of these heating systems with the plasma is reviewed, the relevant experimental results in the exploitation of the heating and current drive capabilities of each system are discussed, key aspects of their application to ITER are outlined, and the major technological developments required in each area are summarized. (author)

  14. Neoclassical offset toroidal velocity and auxiliary ion heating in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Lazzaro, E., E-mail: lazzaro@ifp.cnr.it [Istituto di Fisica del Plasma CNR (Italy)

    2016-05-15

    In conditions of ideal axisymmetry, for a magnetized plasma in a generic bounded domain, necessarily toroidal, the uniform absorption of external energy (e.g., RF or any isotropic auxiliary heating) cannot give rise to net forces or torques. Experimental evidence on contemporary tokamaks shows that the near central absorption of RF heating power (ICH and ECH) and current drive in presence of MHD activity drives a bulk plasma rotation in the co-I{sub p} direction, opposite to the initial one. Also the appearance of classical or neoclassical tearing modes provides a nonlinear magnetic braking that tends to clamp the rotation profile at the q-rational surfaces. The physical origin of the torque associated with P{sub RF} absorption could be due the effects of asymmetry in the equilibrium configuration or in power deposition, but here we point out also an effect of the response of the so-called neoclassical offset velocity to the power dependent heat flow increment. The neoclassical toroidal viscosity due to internal magnetic kink or tearing modes tends to relax the plasma rotation to this asymptotic speed, which in absence of auxiliary heating is of the order of the ion diamagnetic velocity. It can be shown by kinetic and fluid calculations, that the absorption of auxiliary power by ions modifies this offset proportionally to the injected power thereby forcing the plasma rotation in a direction opposite to the initial, to large values. The problem is discussed in the frame of the theoretical models of neoclassical toroidal viscosity.

  15. Ignition and burn propagation with suprathermal electron auxiliary heating

    International Nuclear Information System (INIS)

    Han Shensheng; Wu Yanqing

    2000-01-01

    The rapid development in ultrahigh-intensity lasers has allowed the exploration of applying an auxiliary heating technique in inertial confinement fusion (ICF) research. It is hoped that, compared with the 'standard fast ignition' scheme, raising the temperature of a hot-spot over the ignition threshold based on the shock-heated temperature will greatly reduce the required output energy of an ignition ultrahigh-intensity pulse. One of the key issues in ICF auxiliary heating is: how can we transport the exogenous energy efficiently into the hot-spot of compressed DT fuel? A scheme is proposed with three phases. First, a partial-spherical-shell capsule, such as double-conical target, is imploded as in the conventional approach to inertial fusion to assemble a high-density fuel configuration with a hot-spot of temperature lower than the ignition threshold. Second, a hole is bored through the shell outside the hot-spot by suprathermal electron explosion boring. Finally, the fuel is ignited by suprathermal electrons produced in the high-intensity ignition laser-plasma interactions. Calculations with a simple hybrid model show that the new scheme can possibly lead to ignition and burn propagation with a total drive energy of a few tens of kilojoules and an output energy as low as hundreds of joules for a single ignition ultrahigh-intensity pulse. (author)

  16. Energy confinement scaling in tokamaks: some implications of recent experiments with ohmic and strong auxiliary heating

    International Nuclear Information System (INIS)

    Goldston, R.J.

    1984-02-01

    Recent results from confinement scaling experiments on tokamaks with ohmic and strong auxiliary heating are reviewed. An attempt is made to draw these results together into a low-density ohmic confinement scaling law, and a scaling law for confinement with auxiliary heating. The auxiliary heating confinement law may also serve to explain the saturation in tau/sub E/ vs anti n/sub e/ observed in some ohmic heating density scaling experiments

  17. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation, including...

  18. Clinical observation on thermophysics in radiofrequency heating

    International Nuclear Information System (INIS)

    Qi Chao; Li Dingjiu; Guo Baozhong; Shi Yonggang; Yang Daoke

    2002-01-01

    Objective: To study the physical characters of NRL-001 heating machine. Methods: 151 patients with deep-seated tumors were heated by NRL-001 heating machine in the recent one year. NRL-001 heating machine with two pairs of perpendicular electrodes intercross the two magnetic fields at the center. thermocouples were placed in rectum, ear, esophageal lumen, tumor mass and peritoneal cavity for temperature measurement. The accuracy of the measurement system was evaluated by comparing the rectal mercury thermometer reading with the machine measured value right after the completion of heating. Results: The deviation between the values read by rectal mercury thermometer and the machine was 0.1-0.7 degree C. Intra-tumoral measurement in a patient with lung carcinoma revealed that the temperature within the tumor was 2.0 degree C higher than that in the esophagus. When the peritoneal cavity was heated after perfusion with hot normal saline, the temperature in peritoneal cavity was 0.5 degree C higher than that in the rectum which became even with heating time. Temperature homogeneity was obtained after 50 minutes and abdominal massage was able to shorten this interval. Conclusions: The temperature measurement system of NRL-001 heating machine, having acceptable discrepancies from the mercury thermometer, is reliable. The temperature in the ear, esophagus and rectum can be trusted when treating esophageal or peritoneo-pelvic lesions. Temperature in the esophagus is 2.0 degree C lower than that in lung tumor. Temperature measured in the heated region is about 2.0 degree C higher than that over the whole body. Intra-tumoral temperature measurement is highly recommended if possible. Peritoneo-pelvic heating after peritoneal perfusion is feasible, with the temperature homogeneity obtained as heating time is prolonged, thereby heating time over 120 min is recommended. Temperature measurement is, in fact, necessary for every session of hyperthermia

  19. 46 CFR 52.01-35 - Auxiliary, donkey, fired thermal fluid heater, and heating boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Auxiliary, donkey, fired thermal fluid heater, and... (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-35 Auxiliary, donkey, fired thermal... requirements for miscellaneous boiler types, such as donkey, fired thermal fluid heater, heating boiler, etc...

  20. Stochasticity and superadiabaticity in radiofrequency plasma heating

    International Nuclear Information System (INIS)

    Stix, T.H.

    1979-04-01

    In a plasma subject to radiofrequency fields, it is only the resonant particles - comprising just a minor portion of the total velocity distribution - which are strongly affected. Under near-fusion conditions, thermalization by Coulomb collisions is slow, and noncollisional stochasticity can play an important role in reshaping f(v). It is found that the common rf interactions, including Landau, cyclotron and transit-time damping, can be fitted in a unified manner by a simple two-step one-parameter (epsilon) mapping which can display collision-free stochastic or adiabatic (also called superadiabatic) behavior, depending on the choice of epsilon. The effect on the evolution of the space averaged f (x,v,t) is reasonably well described by a pseudo-stochastic diffusion function, D/sub PS/(v,epsilon) which is the quasilinear diffusion coefficient but with appropriate widening of the delta-function spikes. Coulomb collisions, leading to D/sub Coul/(v) which may be added and directly compared to D/sub PS/(v,epsilon), are introduced by Langevin terms in the mapping equations

  1. Heat removal performance of auxiliary cooling system for the high temperature engineering test reactor during scrams

    International Nuclear Information System (INIS)

    Takeda, Takeshi; Tachibana, Yukio; Iyoku, Tatsuo; Takenaka, Satsuki

    2003-01-01

    The auxiliary cooling system of the high temperature engineering test reactor (HTTR) is employed for heat removal as an engineered safety feature when the reactor scrams in an accident when forced circulation can cool the core. The HTTR is the first high temperature gas-cooled reactor in Japan with reactor outlet gas temperature of 950 degree sign C and thermal power of 30 MW. The auxiliary cooling system should cool the core continuously avoiding excessive cold shock to core graphite components and water boiling of itself. Simulation tests on manual trip from 9 MW operation and on loss of off-site electric power from 15 MW operation were carried out in the rise-to-power test up to 20 MW of the HTTR. Heat removal characteristics of the auxiliary cooling system were examined by the tests. Empirical correlations of overall heat transfer coefficients were acquired for a helium/water heat exchanger and air cooler for the auxiliary cooling system. Temperatures of fluids in the auxiliary cooling system were predicted on a scram event from 30 MW operation at 950 degree sign C of the reactor outlet coolant temperature. Under the predicted helium condition of the auxiliary cooling system, integrity of fuel blocks among the core graphite components was investigated by stress analysis. Evaluation results showed that overcooling to the core graphite components and boiling of water in the auxiliary cooling system should be prevented where open area condition of louvers in the air cooler is the full open

  2. Theoretical and numerical analysis of auxiliary heating for cryogenic target fabrication

    International Nuclear Information System (INIS)

    Yang Xiaohu; Tian Chenglin; Yin Yan; Xu Han; Zhuo Hongbin

    2008-01-01

    In order to compensate for the nonspherical-symmetric heat flux in the hohlraum, auxiliary heating is usually applied to the outside wall of the hohlraum during the cooling process. A one-dimensional heat exchange theoretical model has been proposed in the indirect-drive target, to analyze the required auxiliary heat flux. With a two dimensional axisymmetric model, the auxiliary heating mechanism has been simulated by FLUENT code. The optimum heat flux which is 635 W/m 2 has been obtained as the heaters around the outside of the hohlraum about 1.3 mm above and below the mid-plane. The result is in good agreement with the theoretical model. (authors)

  3. Electrode design for soil decontamination with Radio-Frequency heating

    Energy Technology Data Exchange (ETDEWEB)

    Roland, U.; Holzer, F.; Kraus, M.; Trommler, U.; Kopinke, F.D. [Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, Leipzig (Germany)

    2011-10-15

    Radio-frequency heating to enhance soil decontamination requires adjusted solutions for the electrode design depending on scale and remediation technique. Parallel plate electrodes provide widely homogeneous field and temperature distributions and are, therefore, most suitable for supporting biodegradation processes. For thermally enhanced soil vapor extraction, certain temperature gradients can be accepted and, therefore, the less-demanding geometry of rod-shaped electrodes is usually applied. For electrode lengths of some meters, a design with an air gap has to be used in order to focus heating to the desired depth. Perforated rod electrodes may be simultaneously employed as extraction wells. Placing an oxidation catalyst in situ within the electrodes is an option for handling of highly loaded air flows. Coaxial antenna may be utilized to selectively heat soil compartments far from the surface of the soil. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Preliminary report on the development of rf auxiliary heating systems for TEPR-1

    International Nuclear Information System (INIS)

    Reed, B.W.; Bowen, O.N.; Hill, H.M.; Lawson, J.Q.; Newman, W.G.; Sivo, A.J.

    1977-12-01

    Conceptual designs for 50 MW (expandable to 100 MW) ICRF and LHRF heating systems suitable for auxiliary heating of the TEPR-1 plasma to ignition temperatures are presented. Engineering milestones are enumerated and the extensions of current technology required for successful completion of the project are identified

  5. Radiofrequency Waves, Heating and Current Drive in Magnetically Confined Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Porkolab, M; Bonoli, P T; Temkin, R J [Plasma Science and Fusion Center, MIT, Cambridge, MA (United States); Pinsker, R I; Prater, R [General Atomics, San Diego, California (United States); Wilson, J R [Princeton Plasma Physics Laboratory, Princeton, NJ (United States)

    2012-09-15

    The need for supplementary heating of magnetically confined plasmas to fusion relevant temperatures ({approx}20 keV) has been recognized from the beginning of modern fusion plasma research. Although in tokamaks the plasmas are formed initially by ohmic heating (P{Omega}{approx}{eta}{sub R}j, where j is the current density and {eta}{sub R} is the resistivity) its effectiveness deteriorates with increasing temperature since the resistivity decreases as T{sub e}{sup -3/2}, and losses due to bremsstrahlung radiation increase as Z{sub eff}{sup 3} T{sub e}{sup 1/2} (where Z{sub eff} is the effective ion charge), and the plasma current cannot be raised to arbitrarily large values because of MHD stability limits. In addition, energy losses due to thermal conduction P{sub loss} are typically anomalously large compared to neoclassical predictions and the dependence on temperature is not well understood. Thus, the simplest form of steady state power balance indicates that losses due to radiation and heat conduction must be balanced by auxiliary heating of some form, P{sub aux}, which may simply be stated as P{sub {Omega}} + P{sub {alpha}} - P{sub loss} P{sub aux} where P{sub {alpha}} is the power input provided by alpha particles, which does not become significant until the temperature exceeds some tens of keV, depending on confinement and density. (author)

  6. Auxiliary heat exchanger for a gas-cooled nuclear reactor

    International Nuclear Information System (INIS)

    Ecker, H.; Gasch, K.; Lischer, R.; Spilker, H.

    1978-01-01

    The proposal concerns the design configuration of the individual components of a heat exchanger with circular cross-section, being placed within a lined pod of the concrete shell of the pressure vessel. The heat exchanger has got a vertical cooler installed below the circulator. The components are arranged in such manner that the access to the pipe lines for in-service inspections is assured. Uniform velocity distribution of the gas streaming into the cooler from below is to be achieved. (GL) 891 GL/GL 892 MKO [de

  7. Natural convection in an asymmetrically heated vertical channel with an adiabatic auxiliary plate

    International Nuclear Information System (INIS)

    Taieb, Soumaya; Hatem, Laatar Ali; Balti, Jalloul

    2013-01-01

    The effect of an auxiliary plate on natural convection in an asymmetrically heated channel is studied numerically in laminar regime. The computational procedure is made by solving the unsteady two dimensional Navier-Stokes and energy equations. This nonlinear system is integrated by a finite volume approach and then solved in time using the projection method, allowing the decoupling pressure from velocity. More than hundred simulations are performed to determine the best positions of the auxiliary plate that enhance the induced mass flow and the heat transfer rate for modified Rayleigh numbers ranging from Ra m = 10 2 to Ra m = 10 5 . Contour maps are plotted and then used to precise the enhancement rates of the mass flow and the heat transfer for any position of the auxiliary plate in the channel. The numerical results (velocity, pressure and temperature fields) provide detailed information about the evolution of the flow structure according to the geometry considered in this study. In addition, they permit to explain why the mass flow rate and Nusselt number are enhanced for certain positions of the auxiliary plate and are on the contrary deteriorated for others. (authors)

  8. Fusion plasma theory: Task 3, Auxiliary heating in tokamaks

    International Nuclear Information System (INIS)

    Scharer, J.E.

    1989-07-01

    The research that we have accomplished during the past year (1988--1989) includes the topics of ICRF fast wave waveguide coupling to H-mode profiles simulating CIT and full wave ICRF field solutions and a power conservation relation based on fundamental principles with JET and CIT heating applications. We have also published work on Fokker-Planck simulations of minority ion ICRF strong core electron sawteeth processes in JET, a publication on the effect of plasma edge density fluctuation and ponderomotive force effects on the coupling of ion Bernstein waves and a publication on the coupling of dielectric filled waveguides to plasmas in the ICRF. The analysis of ICRF H-mode coupling is crucial to the economic success of proposed ignition devices such as CIT and ITER. We have analyzed the coupling of ICRF waveguide launchers to H-mode density profiles modelled by a pedestal width and Gaussian edge variations with gradients comparable to current machines. We find that the launcher aperture spectrum, density gradients and width of the pedestal are important parameters in determining the coupling efficiency. The launcher-plasma admittance spectrum in k y -k z space is utilized to show that the H-mode launcher reflections increase when compared to the L-mode profile, but that they can be handled by launcher matching circuits and modest modifications of the H-mode profile. We plan to analyze the recent successful JET ICRF H-mode operation utilizing our formalism. We have also carried out a full wave ICRF field solution and the associated power conservation relation with expressions evaluated up to the third harmonic. We have implemented this in a computer code which utilizes invariant imbedding to solve the system of equations. 7 refs., 1 tab

  9. Biased divertor performance under auxiliary heating conditions on the TdeV tokamak

    International Nuclear Information System (INIS)

    Decoste, R.; Lachambre, J.L.; Demers, Y.

    1994-01-01

    Plasma biasing has been shown on TdeV in the ohmic regime to be very promising for divertor applications. Negative biasing, with shortened SOL density gradients, improves the divertor performance, whereas positive biasing, with longer gradients, does not do much for the divertor. The next objectives were to extrapolate those results to auxiliary heated plasmas and optimize/simplify the biasing geometry for future upgrades. New results are now available with an improved divertor geometry and auxiliary heating/current drive provided by a new lower hybrid (LH) system. The new geometry, optimized for positive biasing with predictably acceptable negative biasing performances, allows for a fair comparison between the two polarities. (author) 4 refs., 5 figs

  10. Energy Saving Glass Lamination via Selective Radio-Frequency Heating

    Energy Technology Data Exchange (ETDEWEB)

    Shulman, Holly S.; Allan, Shawn M.

    2009-11-11

    This Inventions and Innovations program supported the technical and commercial research and development needed to elevate Ceralink's energy saving process for flat glass lamination from bench scale to a self-supporting technology with significant potential for growth. Radio-frequency heating was any un-explored option for laminating glass prior to this program. With significant commercial success through time and energy savings in the wood, paper, and plastics industries, RF heating was found to have significant promise for the energy intensive glass lamination industry. A major technical goal of the program was to demonstrate RF lamination across a wide range of laminate sizes and materials. This was successfully accomplished, dispelling many skeptics' concerns about the abilities of the technology. Ceralink laminated panels up to 2 ft x 3 ft, with four sets processed simultaneously, in a 3 minute cycle. All major categories of interlayer materials were found to work with RF lamination. In addition to laminating glass, other materials including photovoltaic silicon solar cells, light emitting diodes, metallized glass, plastics (acrylic and polycarbonate), and ceramics (alumina) were found compatible with the RF process. This opens up a wide range of commercial opportunities beyond the initially targeted automotive industry. The dramatic energy savings reported for RF lamination at the bench scale were found to be maintained through the scale up of the process. Even at 2 ft x 3 ft panel sizes, energy savings are estimated to be at least 90% compared to autoclaving or vacuum lamination. With targeted promotion through conference presentations, press releases and internet presence, RF lamination has gained significant attention, drawing large audiences at American Ceramic Society meetings. The commercialization success of the project includes the establishment of a revenue-generating business model for providing process development and demonstrations for

  11. Study on enhancement of heat transfer of reactor vessel auxiliary cooling system of fast breeder reactor

    International Nuclear Information System (INIS)

    Nishi, Yoshihisa; Kinoshita, Izumi; Ueda, Nobuyuki; Furuya, Masahiro

    1996-01-01

    A reactor vessel auxiliary cooling system (RVACS), which is one of the decay heat removal systems of the fast breeder reactor (FBR), has passive safety as well as high reliability. However, the heat removal capability is relatively small, because its heat exchange is dependent on the natural convection of the air. The objectives of this report are to propose a heat transfer medium to enhance the heat transfer and to confirm the heat transfer performance of this system by experimental and analytical studies. From these studies, the following main results were obtained. (1) A porous plate with 5 mm thickness, 5 mm pore diameter, 92% porosity, was found to have the highest enhancement of heat transfer. (2) The heat transfer enhancement was demonstrated by large scale heat transfer experiments. Also, the heat transfer correlations, which can be used in the plant transient analyses, were derived from the experimental results. (3) Analysing the transient conditions of conventional pool-type FBR by means of the system analysis code, the applicable range of this system was assumed from the capability of the RVACS with porous plates. As a result, this type of RVACS was found to be applicable to conventional pool-type FBRs with capacity of about 500 MWe or less. (author)

  12. Study on decay heat removal capability of reactor vessel auxiliary cooling system

    International Nuclear Information System (INIS)

    Nishi, Y.; Kinoshita, I.

    1991-01-01

    The reactor vessel auxiliary cooling system (RVACS) is a simple, Passive decay heat removal system for an LMFBR. However, the heat removal capacity of this system is small compared to that of an immersed type of decay heat exchanger. In this study, a high-porosity porous body is proposed to enhance the RVACS's heat transfer performance to improve its applicability. The objectives of this study are to propose a new method which is able to use thermal radiation effectively, to confirm its heat removal capability and to estimate its applicability limit of RVACS for an LMFBR. Heat transfer tests were conducted in an experimental facility with a 3.5 m heat transfer height to evaluate the heat transfer performance of the high-porosity porous body. Using the experimental results, plant transient analyses were performed for a 300 MWe pool type LMFBR under a Total Black Out (TBO) condition to confirm the heat removal capability. Furthermore, the relationship between heat removal capability and thermal output of a reactor were evaluated using a simple parameter model

  13. Evaluation of heat exchange performance for the auxiliary component cooling water system cooling tower in HTTR

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Kameyama, Yasuhiko; Shimizu, Atsushi; Inoi, Hiroyuki; Yamazaki, Kazunori; Shimizu, Yasunori; Aragaki, Etsushi; Ota, Yukimaru; Fujimoto, Nozomu

    2006-09-01

    The auxiliary component cooling water system (ACCWS) is one of the cooling system in High Temperature Engineering Test Reactor (HTTR). The ACCWS has main two features, many facilities cooling, and heat sink of the vessel cooling system which is one of the engineering safety features. Therefore, the ACCWS is required to satisfy the design criteria of heat removal performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the ACCWS cooling tower was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that ACCWS cooling tower has the required heat exchange performance in the design. (author)

  14. Performance evaluation of a state-of-the-art solar air-heating system with auxiliary heat pump

    Science.gov (United States)

    1980-01-01

    The system in Solar House 2 consists of 57.9 sq. m. of Solaron Series 300 Collectors, 10.3 cu. m. of pebble bed storage, domestic water preheating capability and a Carrier air-to-air heat pump as an auxiliary heater. Although the control subsystem was specially constructed to facilitate experimental changes and data reduction, the balance of the solar system was assembled with off-the-shelf components. Since all components of the system are commercially available the system is considered to be a state of the art solar air-heating system. The system design is one that is recommended for residential and small office buildings.

  15. Moment approach to neoclassical flows, currents and transport in auxiliary heated tokamaks

    International Nuclear Information System (INIS)

    Kim, Yil Bong.

    1988-02-01

    The moment approach is utilized to derive the full complement of neoclassical transport processes in auxiliary heated tokamaks. The effects of auxiliary heating [neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH)] considered arise from the collisional interaction between the background plasma species and the fast-ion-tail species. From a known fast ion distribution function we evaluate the parallel (to the magnetic field) momentum and heat flow inputs to the background plasma. Then, through the momentum and heat flow balance equations, we can determine the induced parallel flows (and current) and radial transpot fluxes in ''equilibrium'' (on the time scale much longer than the collisional relaxation time, i.e., t >> 1ν/sub ii/). In addition to the fast-ion-induced current, the total neoclassical current includes the boostap current, which is driven by the pressure and temperature gradients, the Pfirsch-Schlueter current which is required for charge neutrality, and the neoclassical (including trapped particle effects) Spitzer current due to the parallel electric field. The radial transport fluxes also include off-diagonal compnents in the transport matrix which correspond to the Ware (neoclassical) pinch due to the inductive applied electric field an the fast-ion-induced radial fluxes, in addition to the usual pressure- and temperature-gradient-driven fluxes (particle diffusion and heat conduction). Once the tranport coefficient are completely determined, the radial fluxes and the heat fluxes can be substituted into the density and energy evolution equations to provide a complete description of ''equilibrium'' (δδt << ν/sub ii/) neoclassical transport processes in a plasma. 47 refs., 14 figs

  16. GOTHIC Simulation of APR1400 Auxiliary Charging Pump room heat up

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Hui-Un; Heo, Sun [KHNP, Daejeon (Korea, Republic of)

    2014-10-15

    As a part of the Advanced Power Reactor 1400 (APR1400) U. S. Nuclear Regulatory Commission Design Certification (NRC DC) project, we have been investigating Auxiliary Charging Pump (ACP) room heat up. With reference to the design specification of the ACP room, we determined input information and developed a GOTHIC model of the APR1400 ACP room. This calculation model is described herein, and representative results from the calculation are presented as well. The results of the present paper are used to determine the integrity of ACP operating in the accident. APR 1400 GOTHIC model was developed for ACP room heat up calculation. Calculation results confirm that door opening is cooling the room properly. It is found that the difference due to the surface option of heat conductors is insignificant. Based on this result, further studies should be performed to confirm integrity of ACP.

  17. Plasma heating by radiofrequency in the electron cyclotron resonance (ECR)

    International Nuclear Information System (INIS)

    Cunha Raposo, C. da; Aihara, S.; Universidade Estadual de Campinas

    1982-01-01

    The characteristics of the experimental set-up mounted in the Physical Institute of UFF (Brazil) to produce the gas ionization by radio-frequency are shown and its behaviour when confined by a mirror-geometry magnetic field is studied. The diagnostic is made by a langmuir probe and a prisme spectrogaph is used in order to verify the nature of the ionized helium gas and the degree of purity through its spectral lines. The argon ionization by R.f. is produced in the 'LISA' machine obtain a plasma column of approximatelly 60 cm length and with the Langmuir probe the study of the profile distribution of the plasma parameters such as: electron temperature and density and floating potencial in function of the magnetic field variation is made. The main focus is given to the fundamental electron cyclotron resonance (ECR). A new expression on the ion saturation current (I sub(is)) produced by radiofrequency is developed. (L.C.) [pt

  18. Non-invasive ultrasound-based temperature imaging for monitoring radiofrequency heating-phantom results

    International Nuclear Information System (INIS)

    Daniels, M J; Varghese, T; Madsen, E L; Zagzebski, J A

    2007-01-01

    Minimally invasive therapies (such as radiofrequency ablation) are becoming more commonly used in the United States for the treatment of hepatocellular carcinomas and liver metastases. Unfortunately, these procedures suffer from high recurrence rates of hepatocellular carcinoma (∼34-55%) or metastases following ablation therapy. The ability to perform real-time temperature imaging while a patient is undergoing radiofrequency ablation could provide a significant reduction in these recurrence rates. In this paper, we demonstrate the feasibility of ultrasound-based temperature imaging on a tissue-mimicking phantom undergoing radiofrequency heating. Ultrasound echo signals undergo time shifts with increasing temperature, which are tracked using 2D correlation-based speckle tracking methods. Time shifts or displacements in the echo signal are accumulated, and the gradient of these time shifts are related to changes in the temperature of the tissue-mimicking phantom material using a calibration curve generated from experimental data. A tissue-mimicking phantom was developed that can undergo repeated radiofrequency heating procedures. Both sound speed and thermal expansion changes of the tissue-mimicking material were measured experimentally and utilized to generate the calibration curve relating temperature to the displacement gradient. Temperature maps were obtained, and specific regions-of-interest on the temperature maps were compared to invasive temperatures obtained using fiber-optic temperature probes at the same location. Temperature elevation during a radiofrequency ablation procedure on the phantom was successfully tracked to within ±0.5 0 C

  19. Summary of energy and particle confinement in pellet-fuelled auxiliary-heated discharges on JET

    International Nuclear Information System (INIS)

    Milora, S.L.; Baylor, L.R.; Bartlett, D.V.

    1989-01-01

    A transient improvement in plasma performance and central confinement has been observed in auxiliary heated JET limiter plasmas associated with a peaking of the plasma density profile and strong centralized heating. Suitable target plasmas for ICRF and NBI heating experiments are created by deuterium pellet injection with a multi pellet injector system developed jointly by ORNL and JETZ . Two types of discharge conditions have been observed. In the first (type A), the density profiles decay gradually during the first 1.3s of the heating pulse while maintaining an elevated density core plasma inside r/a < 0.6 superimposed on a flat density pedestal. During this phase the central electron and ion temperatures increase rapidly (up to 12 keV and 10 keV respectively in the best discharges). This results in an increase in the central plasma pressure by approximately a factor of three (β(0) 5%) above gas fuelled discharges and gives rise to sharply increased pressure gradients in the plasma. An abrupt collapse of the central electron and ion temperatures terminates the enhanced phase at 1.3 s and leads eventually to a 20% decrease in plasma stored energy. While these discharges are predicted to be stable to kink modes, they approach the first stability boundary for ballooning modes in the region of steepest pressure gradient. The pressure and q profiles inferred from transport analysis are also close to those for which intermediate-n mode instability is predicted. (author) 11 refs., 4 figs

  20. Aspects Concerning the Heating/Drying of Oak Planks in a Radiofrequency Field

    Directory of Open Access Journals (Sweden)

    LAZA (BULC Marcela

    2013-05-01

    Full Text Available Heat transfer and the evaporation of moisture from wood may be achieved with the help of high-frequency currents, depending on the dielectric properties of wood. Since wood is generally a heterogeneous material, these properties may vary depending on frequency, humidity, temperature and density. This paper presents aspects related to the numerical modeling of the process of heating or drying oak planks arranged in a13.56 MHz radiofrequency applicator, correlated with experiments.

  1. INFLUENCE OF FEEDING ELECTRIC ENERGY QUALITY ON HEATING OF THE AUXILIARY MA-CHINES OF AC ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    O. YU. Baliichuk

    2014-04-01

    Full Text Available Purpose. The article aims to study the problem of increase the reliability of auxiliary machines for AC electric trains during operation in real conditions. Methodology. The peculiarity of system construction of auxiliary machines for AC electric rolling stock is the use of asynchronous motors for general industrial purpose. An engineering method of influence determination on the feeding voltage asymmetry and its deviation from the nominal value on heating of auxiliary machines insulation was proposed. Findings. It is found out that in case when the auxiliary machines of AC electric trains work under asymmetry factor of the voltage 10% or more and feeding voltage deviation from the nominal order 0.6 relative unit then it is possible the overheat of their isolation, even if it has class H. Originality. For the first time the issue of the total insulation heating under such boundary parameters combinations of energy quality, when each of them contributes to the heating insulation increase as compared to the nominal regime of the "rotating phase splitter−auxiliary machinery" system was illuminated. Practical value. Conducted research allow us to establish the boundary parameter values of feeding energy quality (asymmetry factor, feeding voltage deviations from the nominal value, at which additional isolation overheating of this class under the effect of specified factors will not exceed the agreed value.

  2. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Y.; Wang, W. X.; LeBlanc, B. P.; Guttenfelder, W.; Kaye, S. M.; Ethier, S.; Mazzucato, E.; Bell, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lee, K. C. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Domier, C. W. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2015-11-15

    In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delay of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. The observations imply that nonlocal flux-driven mechanism may be important for the observed turbulence and electron thermal transport.

  3. Heat Sink Effect on Tumor Ablation Characteristics as Observed in Monopolar Radiofrequency, Bipolar Radiofrequency, and Microwave, Using Ex Vivo Calf Liver Model

    Science.gov (United States)

    Pillai, Krishna; Akhter, Javid; Chua, Terence C.; Shehata, Mena; Alzahrani, Nayef; Al-Alem, Issan; Morris, David L.

    2015-01-01

    Abstract Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices. With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored. With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres. Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected. Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5. MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. PMID:25738477

  4. Comparison of collective Thomson scattering signals due to fast ions in ITER scenarios with fusion and auxiliary heating

    DEFF Research Database (Denmark)

    Salewski, Mirko; Asunta, O.; Eriksson, L.-G.

    2009-01-01

    Auxiliary heating such as neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH) will accelerate ions in ITER up to energies in the MeV range, i.e. energies which are also typical for alpha particles. Fast ions of any of these populations will elevate the collective Thomson...... functions of fast ions generated by NBI and ICRH are calculated for a steady-state ITER burning plasma equilibrium with the ASCOT and PION codes, respectively. The parameters for the auxiliary heating systems correspond to the design currently foreseen for ITER. The geometry of the CTS system for ITER...... is chosen such that near perpendicular and near parallel velocity components are resolved. In the investigated ICRH scenario, waves at 50MHz resonate with tritium at the second harmonic off-axis on the low field side. Effects of a minority heating scheme with He-3 are also considered. CTS scattering...

  5. Quench propagation and heating in the superconducting 600 A auxiliary busbars of the LHC

    International Nuclear Information System (INIS)

    Herzog, R.; Calvi, M.; Sonnemann, F.

    2002-01-01

    In the Large Hadron Collider (LHC) at CERN 22 km of flexible superconducting cable, the auxiliary busbar cable, will conduct currents of up to 600 A to a large number of corrector magnets distributed throughout the accelerator. A prototype cable with 42 active conductors underwent several experiments to measure the hot spot temperature and the quench propagation velocity as a function of the current. The former was evaluated for various energy extraction scenarios as they are foreseen for the LHC corrector circuits. The experimental results and the heat flow simulations show that the quench behavior in this busbar prototype is strongly influenced by the heat flow through the insulation material (polyimide) into the helium bath, leading to stable configurations above the critical temperature T c for currents between 250 A and 500 A. Special attention was paid to the study of discontinuities in the wires, like feed-throughs, where the wire is not immersed in liquid helium, and joints, where the wire cross-section is increased. The experiments and simulations led to a thorough understanding of the quench process in the wires of the prototype cable, which resulted in guidelines for the design, the use and the installation of the cable in the LHC

  6. Vacuum pumping system for the JT-60 radio-frequency heating system

    International Nuclear Information System (INIS)

    Yokokura, Kenji; Ikeda, Yoshitaka; Imai, Tuyoshi; Suganuma, Kazuaki; Nagashima, Takashi

    1988-01-01

    The basic design requirements set up for the JT-60 radio-frequency heating system included: (1) rapid pumping of gas released upon application of a radio-frequency power to maintain the pressure in the launchers at 10 -2 - 10 -3 Pa or less, (2) incorporation of a gas analysis system that can operate under a strong field and high pressure (>10 -2 Pa) to permit remote controlled data collection and processing, and (3) low cost, multiple functions and high reliability. The vacuum pumping system, consisting of three units for low hybrid radio-frequency (LHRF) and one unit for ion cyclotron radio-frequency (ICRF), is connected to each launcher provided at the four ports of JT-60. The LHRF unit is composed of a main pump, an alumina joint for electrical insulation from the launcher, a metallic gate valve for isolation from the JT-60 vacuum region, and various vacuum gauges. Only a turbo-molecular pump is used for the ICRF system because a large-scale differential pumping is not required. A gas measuring system is incorporated which consists of a mass filter, personal computer, turbo-molecular pump, and variable flow valve equipped with an APG control. This system is designed to identify and make use of gas impurities released during the launcher aging process. The control system employed consists of a personal computer, interlock control board, data logger and other devices such as vacuum gages. (Nogami, K.)

  7. Seismic dynamic analysis of Heat Exchangers inside of the Auxiliary Buildings in AP1000TM NPP

    International Nuclear Information System (INIS)

    Di Fonzo, M.; Aragon, J.; Moraleda, F.; Palazuelos, M.; San Vicente, J. L.

    2011-01-01

    Seismic dynamic analysis was carried out for the Heat Exchangers (RNS-HR) located inside of the Auxiliary Building in AP 1000 T M NPP. The main function of the RNS-HX is to provide shutdown reactor cooling. These equipment's are safety-related. So the seismic analysis was done using the methodology for Seismic Category I (SCI) structures. The most important topic is that the RNS-HX shall withstand the effects of the Safe Shutdown Earthquake (SSE) and maintain the specified design functions. for the analysis, two finite element models (FEM) were built in order to investigate the structural response of the couple system of building and equipment. The response spectra method was used. The floor response spectra (FRS) at the slab-wall connection were used as input Lateral seismic restrain was necessary to added in order to achieve the natural frequency of 33 Hz. The global structural response was obtained by means of the modal combination method indicated in the Regulatory Guide 1.92.

  8. Temperature responsive porous silicon nanoparticles for cancer therapy - spatiotemporal triggering through infrared and radiofrequency electromagnetic heating.

    Science.gov (United States)

    Tamarov, Konstantin; Xu, Wujun; Osminkina, Liubov; Zinovyev, Sergey; Soininen, Pasi; Kudryavtsev, Andrey; Gongalsky, Maxim; Gaydarova, Azha; Närvänen, Ale; Timoshenko, Victor; Lehto, Vesa-Pekka

    2016-11-10

    One critical functionality of the carrier system utilized in targeted drug delivery is its ability to trigger the release of the therapeutic cargo once the carrier has reached its target. External triggering is an alluring approach as it can be applied in a precise spatiotemporal manner. In the present study, we achieved external triggering through the porous silicon (PSi) nanoparticles (NPs) by providing a pulse of infrared or radiofrequency radiation. The NPs were grafted with a temperature responsive polymer whose critical temperature was tailored to be slightly above 37°C. The polymer coating improved the biocompatibility of the NPs significantly in comparison with their uncoated counterparts. Radiation induced a rapid temperature rise, which resulted in the collapse of the polymer chains facilitating the cargo release. Both infrared and radiofrequency radiation were able to efficiently trigger the release of the encapsulated drug in vitro and induce significant cell death in comparison to the control groups. Radiofrequency radiation was found to be more efficient in vitro, and the treatment efficacy was verified in vivo in a lung carcinoma (3LL) mice model. After a single intratumoral administration of the carrier system combined with radiofrequency radiation, there was clear suppression of the growth of the carcinoma and a prolongation of the survival time of the animals. The temperature responsive (TR) polymer grafted on the surface of porous silicon nanoparticles (PSi NPs) changes its conformation in response to the heating induced by infrared or radiofrequency radiation. The conformation change allows the loaded doxorubicin to escape from the pores, achieving controlled drug release from TR PSi NPs, which displayed efficacy against malignant cells both in vitro and in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Development of 8 MW Power Supply Based on Pulse Step Modulation Technique for Auxiliary Heating System on HL-2A

    International Nuclear Information System (INIS)

    Xu Weidong; Xuan Weimin; Yao Lieying; Wang Yingqiao

    2012-01-01

    The high voltage power supply (HVPS) based on pulse step modulation (PSM) has already been developed for the auxiliary heating system on HL-2A. This power supply consists of many switch power supplies, and its output voltage can be obtained by modulating their delay time and pulse widths. The PSM topology and control principle are presented in this paper. The simple algorithms for the control system are explained clearly. The switch power supply (SPS) module has been built and the test results show it can meet the requirements of the auxiliary heating system. Now, 112 SPS modules and the whole system have already been developed. Its maximum output is about 72 kV/93 A. The protection time is less than 5 μs. The different outputs of this power supply are used for the electron cyclotron resonant heating (ECRH) system with different duty ratios. The experimental results of the entire system are presented. The results indicate that the whole system can meet the requirements of the auxiliary heating system on HL-2A.

  10. Modeling of the L.F. turbulent spectrum during ohmic discharges, auxiliary heating and disruptions in Tokamak

    International Nuclear Information System (INIS)

    Truc, A.

    1983-07-01

    The spectrum of low frequency turbulence in the TFR tokamak, as observed along a central chord by a CO 2 laser light diffusion diagnostic, appears to be representable by four monomial branches joining to three vertices. This schematic representation permits to follow more easily the evolution of the turbulence during the life of the plasma, including the ohmic regime, the transitions to auxiliary heating and the minor and major disruptions

  11. 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.

  12. Heat explosion approach to radiofrequency heating of a conductor film on silicon substrate: Application for silicide film formation

    International Nuclear Information System (INIS)

    Pelleg, J.; Rosenberg, S.; Sinder, M.

    2011-01-01

    A qualitative analysis of the kinetics of phase formation in a conductor film/Si substrate system by radiofrequency (RF) heating is presented. The analysis is done by using the mathematical approach of the heat explosion theory. It is shown that the system can experience heating at constant temperature or a sudden temperature increase, i.e. heat explosion. The relation between the parameters of the system in the heat explosion regime is presented in a simple analytical form. It was found that measurable quantities, such as film thickness, sheet resistance, specimen dimensions and applied magnetic field, determine whether the process occurs in the constant heating or heat explosion stages. The model was tested for the Ta-Ti-Si system by considering some of the mentioned measurable quantities which were obtained by RF induction heating of Ta-Ti film on Si(1 1 1) and Si(1 0 0) substrates. The agreement of theory with experiment is reasonable. Concentration of Ta in the conductor film, film thickness and the orientation of the Si substrate might influence the reaction rate. On Si(1 1 1) substrates the reaction goes to completion, whereas on Si(1 0 0) intermediate phases remain. This observation was explained in terms of an interface reaction-controlled process of Si atoms transferring from the substrate to the film.

  13. A minimization procedure for estimating the power deposition and heat transport from the temperature response to auxiliary power modulation

    International Nuclear Information System (INIS)

    Eester, Dirk van

    2004-01-01

    A method commonly used for determining where externally launched power is absorbed inside a tokamak plasma is to examine the temperature response to modulation of the launched power. Strictly speaking, this response merely provides a first good guess of the actual power deposition rather than the deposition profile itself: not only local heat sources but also heat losses and heat wave propagation affect the temperature response at a given position. Making use of this, at first sight non-desirable, effect modulation becomes a useful tool for conducting transport studies. In this paper a minimization method based on a simple conduction-convection model is proposed for deducing the power deposition and transport characteristics from the experimentally measured (electron) energy density response to a modulation of the auxiliary heating power. An L-mode JET example illustrates the potential of the technique

  14. 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.

  15. Radiofrequency Thermal Ablation Heat Energy Transfer in an Ex-Vivo Model.

    Science.gov (United States)

    Thakur, Shivani; Lavito, Sandi; Grobner, Elizabeth; Grobner, Mark

    2017-12-01

    Little work has been done to consider the temperature changes and energy transfer that occur in the tissue outside the vein with ultrasound-guided vein ablation therapy. In this experiment, a Ex-Vivo model of the human calf was used to analyze heat transfer and energy degradation in tissue surrounding the vein during endovascular radiofrequency ablation (RFA). A clinical vein ablation protocol was used to determine the tissue temperature distribution in 10 per cent agar gel. Heat energy from the radiofrequency catheter was measured for 140 seconds at fixed points by four thermometer probes placed equidistant radially at 0.0025, 0.005, and 0.01 m away from the RFA catheter. The temperature rose 1.5°C at 0.0025 m, 0.6°C at 0.005 m, and 0.0°C at 0.01 m from the RFA catheter. There was a clinically insignificant heat transfer at the distances evaluated, 1.4 ± 0.2 J/s at 0.0025 m, 0.7 ± 0.3 J/s at 0.0050 m, and 0.3 ± 0.0 J/s at 0.01 m. Heat degradation occurred rapidly: 4.5 ± 0.5 J (at 0.0025 m), 4.0 ± 1.6 J (at 0.0050 m), and 3.9 ± 3.6 J (at 0.01 m). Tumescent anesthesia injected one centimeter around the vein would act as a heat sink to absorb the energy transferred outside the vein to minimize tissue and nerve damage and will help phlebologists strategize options for minimizing damage.

  16. Tribological changes on SS304 stainless steel induced by nitrogen plasma immersion ion implantation with and without auxiliary heating

    International Nuclear Information System (INIS)

    Mello, C.B.; Ueda, M.; Lepienski, C.M.; Reuther, H.

    2009-01-01

    In order to achieve quite thick treated layers with reasonable thickness uniformity in SS304 steel, the plasma immersion ion implantation (PIII) process was run in high-temperature, up to 350 deg. C, to induce high thermal diffusion but avoid the white layer formation. In these experiments, we heated the sample-holder with a shielded resistive wire properly wound around it and subjected the SS samples to nitrogen glow discharge PIII with relatively low voltages (10 kV) in different temperatures. We also treated the SS samples by the traditional PIII method, slowly increasing the high voltage pulse intensities, until 14 kV at the end of processing, reaching temperatures of up to 350 deg. C. These modes of treatments were compared with respect to nitrogen implantation profiles, X-ray diffraction, tribology and mechanical properties. X-ray diffraction results indicated a much higher efficiency of auxiliary heated PIII mode compared to the ordinary PIII. Very prominent γ N peaks were observed for the first mode, indicating large concentration of nitrogen in thick layers, confirmed by the nitrogen profiles measured by GDOS and AES. Improved mechanical and tribological properties were obtained for SS304 samples treated by the PIII with auxiliary heating, more than for ordinary PIII. Hardness was enhanced by up to 2.77 times, as seen by nanoindentation tests.

  17. Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

    International Nuclear Information System (INIS)

    Bitter, M.; Wong, K.L.; Scott, S.; Hsuan, H.; Grek, B.; Johnson, D.; Tait, G.

    1990-01-01

    The time history of the central toroidal plasma rotation velocity in Tokamak Fusion Test Reactor (TFTR) experiments [Phys. Rev. Lett. 55, 2587 (1985)] with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted Ti XXI Kα line radiation. The experiments were conducted for neutral beam powers in the range 2.1--3.8 MW and line-averaged densities in the range 1.8--3.0x10 19 m -2 . The observed rotation velocity increase during compression is consistent with theoretical estimates

  18. Heating of polymer substrate by discharge plasma in radiofrequency magnetron sputtering deposition

    International Nuclear Information System (INIS)

    Sirghi, Lucel; Popa, Gheorghe; Hatanaka, Yoshinori

    2006-01-01

    The substrate used for the thin film deposition in a radiofrequency magnetron sputtering deposition system is heated by the deposition plasma. This may change drastically the surface properties of the polymer substrates. Deposition of titanium dioxide thin films on polymethyl methacrylate and polycarbonate substrates resulted in buckling of the substrate surfaces. This effect was evaluated by analysis of atomic force microscopy topography images of the deposited films. The amount of energy received by the substrate surface during the film deposition was determined by a thermal probe. Then, the results of the thermal probe measurements were used to compute the surface temperature of the polymer substrate. The computation revealed that the substrate surface temperature depends on the substrate thickness, discharge power and substrate holder temperature. For the case of the TiO 2 film depositions in the radiofrequency magnetron plasma, the computation indicated substrate surface temperature values under the polymer melting temperature. Therefore, the buckling of polymer substrate surface in the deposition plasma may not be regarded as a temperature driven surface instability, but more as an effect of argon ion bombardment

  19. Heat structure coupling of CUPID and MARS for the multi-scale simulation of the passive auxiliary feedwater system

    International Nuclear Information System (INIS)

    Kyu Cho, Hyoung; Cho, Yun Je; Yoon, Han Young

    2014-01-01

    Graphical abstract: - Highlights: • PAFS is designed to replace a conventional active auxiliary feedwater system. • Multi-D T/H analysis code, CUPID was coupled with the 1-D system analysis code MARS. • The coupled CUPID and MARS was applied for the multi-scale analysis of the PAFS test facility. • The simulation result showed that the coupled code can reproduce important phenomena in PAFS. - Abstract: For the analysis of transient two-phase flows in nuclear reactor components, a three-dimensional thermal hydraulics code, named CUPID, has been developed. In the present study, the CUPID code was coupled with a system analysis code MARS in order to apply it for the multi-scale thermal-hydraulic analysis of the passive auxiliary feedwater system (PAFS). The PAFS is one of the advanced safety features adopted in the Advanced Power Reactor Plus (APR+), which is intended to completely replace the conventional active auxiliary feedwater system. For verification of the coupling and validation of the coupled code, the PASCAL test facility was simulated, which was constructed with an aim of validating the cooling and operational performance of the PAFS. The two-phase flow phenomena of the steam supply system including the condensation inside the heat exchanger tube were calculated by MARS while the natural circulation and the boil-off in the large water pool that contains the heat exchanger tube were simulated by CUPID. This paper presents the description of the PASCAL facility, the coupling method and the simulation results using the coupled code

  20. Modelling of Temperature Profiles and Transport Scaling in Auxiliary Heated Tokamaks

    DEFF Research Database (Denmark)

    Callen, J.D.; Christiansen, J.P.; Cordey, J.G.

    1987-01-01

    time , the heating effectiveness η, and the energy offset W(0). Considering both the temperature profile responses and the global transport scaling, the constant heat pinch or excess temperature gradient model is found to best characterize the present JET data. Finally, new methods are proposed......The temperature profiles produced by various heating profiles are calculated from local heat transport models. The models take the heat flux to be the sum of heat diffusion and a non-diffusive heat flow, consistent with local measurements of heat transport. Two models are developed analytically...... in detail: (i) a heat pinch or excess temperature gradient model with constant coefficients; and (ii) a non-linear heat diffusion coefficient (χ) model. Both models predict weak (lesssim20%) temperature profile responses to physically relevant changes in the heat deposition profile – primarily because...

  1. Sensitivity of energy and exergy performances of heating and cooling systems to auxiliary components

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2017-01-01

    . Different forms of energy (electricity and heat) are used in heating and cooling systems, and therefore, a holistic approach to system design and analysis is needed. In particular, distribution systems use electricity as a direct input to pumps and fans, and to other components. Therefore, exergy concept......Heating and cooling systems in buildings consist of three main subsystems: heating/cooling plant, distribution system, and indoor terminal unit. The choice of indoor terminal unit determines the characteristics of the distribution system and the heating and cooling plants that can be used...... should be used in design and analysis of the whole heating and cooling systems, in addition to the energy analysis. In this study, water-based (floor heating and cooling, and radiator heating) and air-based (air heating and cooling) heating and cooling systems were compared in terms of their energy use...

  2. Measurements of energetic helium-3 minority distributions during ion cyclotron radiofrequency heating in the Princeton large torus

    International Nuclear Information System (INIS)

    Hammett, G.W.; Kaita, R.; Wilson, J.R.

    1988-01-01

    Ion cyclotron radiofrequency heating experiments were performed with a 3 He minority ion species in a 4 He majority plasma in the Princeton Large Torus. The energetic 3 He ion 'tail' was measured directly with a charge exchange neutral analyser for the first time. Comparisons with bounce averaged quasi-linear calculations suggest a modestly peaked radiofrequency power deposition profile. The double charge exchange process 3 He ++ + 4 He o -> 3 He o + 4 He ++ demonstrated in these measurements may be useful as part of an alpha particle diagnostic in a fusion reactor experiment. (author). 21 refs, 4 figs

  3. Minimal vascular flows cause strong heat sink effects in hepatic radiofrequency ablation ex vivo.

    Science.gov (United States)

    Lehmann, Kai S; Poch, Franz G M; Rieder, Christian; Schenk, Andrea; Stroux, Andrea; Frericks, Bernd B; Gemeinhardt, Ole; Holmer, Christoph; Kreis, Martin E; Ritz, Jörg P; Zurbuchen, Urte

    2016-08-01

    The present paper aims to assess the lower threshold of vascular flow rate on the heat sink effect in bipolar radiofrequency ablation (RFA) ex vivo. Glass tubes (vessels) of 3.4 mm inner diameter were introduced in parallel to bipolar RFA applicators into porcine liver ex vivo. Vessels were perfused with flow rates of 0 to 1,500 ml/min. RFA (30 W power, 15 kJ energy input) was carried out at room temperature and 37°C. Heat sink effects were assessed in RFA cross sections by the decrease in ablation radius, area and by a high-resolution sector planimetry. Flow rates of 1 ml/min already caused a significant cooling effect (P ≤ 0.001). The heat sink effect reached a maximum at 10 ml/min (18.4 mm/s) and remained stable for flow rates up to 1,500 ml/min. Minimal vascular flows of ≥1 ml/min cause a significant heat sink effect in hepatic RFA ex vivo. A lower limit for volumetric flow rate was not found. The maximum of the heat sink effect was reached at a flow rate of 10 ml/min and remained stable for flow rates up to 1,500 ml/min. Hepatic inflow occlusion should be considered in RFA close to hepatic vessels. © 2016 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  4. Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

    International Nuclear Information System (INIS)

    Bitter, M.; Scott, S.; Wong, K.L.

    1986-07-01

    The time history of the central toroidal plasma rotation velocity in Tokamak Fusion Test Reactor (TFTR) experiments with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted TiXXI-Kα line radiation. The experiments were conducted for neutral beam powers in the range from 2.1 to 3.8 MW and line-averaged densities in the range from 1.8 to 3.0 x 10 19 m -2 . The observed rotation velocity increase during compression is in agreement with results from modeling calculations which assume classical slowing-down of the injected fast deuterium ions and momentum damping at the rate established in the precompression plasma

  5. Comparative Studies of the Operation Method of Solar Energy Water Heating System with Auxiliary Heat Pump Heater%热泵辅助供热太阳能热水系统运行模式对比分析

    Institute of Scientific and Technical Information of China (English)

    林辩启; 罗会龙; 王浩; 田盼雨

    2015-01-01

    太阳能热水系统与热泵辅助供热合理结合可取长补短,有效降低建筑能耗。简要概述了空气源热泵、水源热泵、地源热泵辅助供热太阳能热水系统的结构形式及其运行模式。在此基础上,对比分析了热泵辅助供热太阳能热水系统各种典型运行模式的特点及其适用的应用环境。%The appropriate combination of solar water heating system and heat pump auxiliary heating is an effective way to reduce the building energy consumption. The structure and operation method of solar water heating system with different auxiliary heating, such as air-source heat pump, water-source heat pump, and soil-source heat pump, were introduced briefly. The characteristics of all kinds of solar water heating system with auxiliary heating were compared and analyzed. The suitable application environment of solar water heating system with auxiliary heating was also presented.

  6. Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    Takase, Y.; Boivin, R.L.; Bombarda, F.; Bonoli, P.T.; Christensen, C.; Fiore, C.; Garnier, D.; Goetz, J.A.; Golovato, S.N.; Granetz, R.; Greenwald, M.; Horne, S.F.; Hubbard, A.; Hutchinson, I.H.; Irby, J.; LaBombard, B.; Lipschultz, B.; Marmar, E.; May, M.; Mazurenko, A.; McCracken, G.; OShea, P.; Porkolab, M.; Reardon, J.; Rice, J.; Rost, C.; Schachter, J.; Snipes, J.A.; Stek, P.; Terry, J.; Watterson, R.; Welch, B.; Wolfe, S.

    1997-01-01

    Enhanced confinement modes up to a toroidal field of B T =8T have been studied with up to 3.5 MW of radiofrequency (rf) heating power in the ion cyclotron range of frequencies (ICRF) at 80 MHz. H-mode is observed when the edge temperature exceeds a threshold value. The high confinement mode (H-mode) with higher confinement enhancement factors (H) and longer duration became possible after boronization by reducing the radiated power from the main plasma. A quasi-steady state with high confinement (H=2.0), high normalized beta (β N =1.5), low radiated power fraction (P rad main /P loss =0.3), and low effective charge (Z eff =1.5) has been obtained in Enhanced D α H-mode. This type of H-mode has enhanced levels of continuous D α emission and very little or no edge localized mode (ELM) activity, and reduced core particle confinement time relative to ELM-free H-mode. The pellet enhanced performance (PEP) mode is obtained by combining core fueling with pellet injection and core heating. A highly peaked pressure profile with a central value of 8 atmospheres was observed. The steep pressure gradient drives off-axis bootstrap current, resulting in a shear reversed safety factor (q) profile. Suppression of sawteeth appears to be important in maintaining the highly peaked pressure profile. Lithium pellets were found to be more effective than deuterium pellets in raising q 0 . copyright 1997 American Institute of Physics

  7. Comparison of the heat shock response induced by conventional heating and two methods of delivery of pulsed radiofrequency energy

    International Nuclear Information System (INIS)

    Laurence, J.A.; University of Sydney, NSW; McKenzie, D.R.; Veas, L.; French, P.W.

    2002-01-01

    Full text: In 2001, we published a (hypothetical) mechanism by which radiofrequency (RF) radiation from mobile phones could induce cancer, via the chronic induction of the heat shock response (HSR). This hypothesis provides the focus for our research. Other groups have reported induction of the HSR by RF at apparently non thermal levels. The aim of this study was to determine whether the HSR induced by RF is (a) truly non thermal and (b) quantitatively or qualitatively different from that induced by conventional heating of cells. A rat mast cell line, RBL-2H3, was chosen as the target RBL-2H3 cells were exposed in an air incubator at 41.1 deg C for 45 minutes and 75 minutes, and then returned to a 37 deg C incubator. Sham exposures were performed in the same air incubator at 37 deg C. Cells were exposed for 1 hour in the two pulsed RF exposure systems. The first was a converted 750W microwave oven that emits a short burst of 2.45GHz pulses at the start of each contiguous six minute period. This exposes cells to an average specific energy absorption rate (SAR) of 20W/kg. The second system was a TEM cell, which simulates. GSM pulses - the earner frequency is 0.9GHz pulse modulated at 217Hz. The SAR was approx 0.1W/kg. Both of these exposure systems are housed in incubators maintained at 37 deg C. Sham exposures were performed in the two systems with the same conditions but with no RF radiation present. Cell samples for the conventional heating and microwave exposures were taken 0, 2. 5, 5 and 20 hours after exposure, and expression of heat shock proteins hsp 110, 90, 70, 60 and 56 were determined by Western Blotting and compared between exposures

  8. Evaluation of transcatheter arterial chemoembolization combined with radiofrequency capacitive heating on clinical therapeutic effect of metastatic carcinoma

    International Nuclear Information System (INIS)

    Chen Qianli; Ye Qiang; Gu Weizhong; Zhang Jiazhong; Tong Qiangang; Xi Shunfa

    2006-01-01

    Objective: To evaluate clinical therapeutic efficacy and adverse efficacy of transcatheter arterial chemoembolization (TACE) combined with radiofrequency capacitive heating (RCH) for metastatic hepatic carcinoma (MHC). Methods: Thirty-nine cases of MHC were enrolled in this study and divided into two groups: study group (n=19) and control group (n=20). Before therapy, the Karnofsky's score of the patients was all beyond 60. Results: The carcinoma growth rate of the study group was -(0.38±0.22), while that of the control group was -(0.13±0.25), showing significant statistical difference (P 0.05). Conclusion: The therapeutic effect of MHC can be further improved by the treatment of TACE combined with radiofrequency capacitive heating without increase of adverse side effects. (authors)

  9. Real time plasma control experiments using the JET auxiliary plasma heating systems as the actuator

    International Nuclear Information System (INIS)

    Zornig, N.H.

    1999-01-01

    The role of the Real Time Power Control system (RTPC) in the Joint European Torus (JET) is described in depth. The modes of operation are discussed in detail and a number of successful experiments are described. These experiments prove that RTPC can be used for a wide range of experiments, including: (1) Feedback control of plasma parameters in real time using Ion Cyclotron Resonance Heating (ICRH) or Neutral Beam Heating (NBH) as the actuator in various JET operating regimes. It is demonstrated that in a multi-parameter space it is not sufficient to control one global plasma parameter in order to avoid performance limiting events. (2) Restricting neutron production and subsequent machine activation resulting from high performance pulses. (3) The simulation of α-particle heating effects in a DT-plasma in a D-only plasma. The heating properties of α-particles are simulated using ICRH-power, which is adjusted in real time. The simulation of α-particle heating in JET allows the effects of a change in isotopic mass to be separated from α-particle heating. However, the change in isotopic mass of the plasma ions appears to affect not only the global energy confinement time (τ E ) but also other parameters such as the electron temperature at the plasma edge. This also affects τ E , making it difficult to make a conclusive statement about any isotopic effect. (4) For future JET experiments a scheme has been designed which simulates the behaviour of a fusion reactor experimentally. The design parameters of the International Thermonuclear Experimental Reactor (ITER) are used. In the proposed scheme the most relevant dimensionless plasma parameters are similar in JET and ITER. It is also shown how the amount of heating may be simulated in real time by RTPC using the electron temperature and density as input parameters. The results of two demonstration experiments are presented. (author)

  10. Copper Heat Exchanger for the External Auxiliary Bus-Bars Routing Line in the LHC Insertion Regions

    CERN Document Server

    Garion, C; Seyvet, F; Sitko, M; Skoczen, B; Tock, J P

    2006-01-01

    The corrector magnets and the main quadrupoles of the LHC dispersion suppressors are powered by a special superconducting line (called auxiliary bus-bars line N), external to the cold mass and housed in a 50 mm diameter stainless steel tube fixed to the cold mass. As the line is periodically connected to the cold mass, the same gaseous and liquid helium cools both the magnets and the line. The final sub-cooling process (from around 4.5 K down to 1.9 K) consists in the phase transformation from liquid to superfluid helium. Heat is extracted from the line through the magnets via their point of junction. In dispersion suppressor zones, approximately 40 m long, the sub-cooling of the line is slightly delayed with respect to the magnets. This might have an impact on the readiness of the accelerator for operation. In order to accelerate the process, a special heat exchanger has been designed. It is located in the middle of the dispersion suppressor portion of the line. Its main function consists in providing a loca...

  11. Radiofrequency heating and magnetically induced displacement of dental magnetic attachments during 3.0 T MRI

    Science.gov (United States)

    Miyata, K; Hasegawa, M; Abe, Y; Tabuchi, T; Namiki, T; Ishigami, T

    2012-01-01

    Objective The aim of this study was to estimate the risk of injury from dental magnetic attachments due to their radiofrequency (RF) heating and magnetically induced displacement during 3.0 T MRI. Methods To examine the magnetic attachments, we adopted the American Society for Testing and Materials F2182-02a and F2052-06 standards in two MRI systems (Achieva 3.0 T Nova Dual; Philips, Tokyo, Japan, and Signa HDxt 3.0 T; GE Healthcare, Milwaukee, WI). The temperature change was measured in a cylindrical keeper (GIGAUSS D600; GC, Tokyo, Japan) with coping of the casting alloy and a keeper with a dental implant at the maximum specific absorption rate (SAR) for 20 min. To measure the magnetically induced displacement force, three sizes of keepers (GIGAUSS D400, D600 and D1000) were used in deflection angle tests conducted at the point of the maximum magnetic field strength. Results Temperature elevations of both coping and implant were higher in the Signa system than in the Achieva system. The highest temperature changes in the keeper with implant and keeper with coping were 0.6 °C and 0.8 °C in the Signa system, respectively. The temperature increase did not exceed 1.0 °C at any location. The deflection angle (α) was not measurable because it exceeded 90°. GIGAUSS D400 required an extra 3.0 g load to constrain the deflection angle to less than 45°; GIGAUSS D600 and D1000 required 5.0 and 9.0 g loads, respectively. Conclusions Dental magnetic attachments pose no risk due to RF heating and magnetically induced displacement at 3.0 T MRI. However, it is necessary to confirm that these keepers are securely attached to the prosthesis before imaging. PMID:22499128

  12. Auxiliary buildings

    International Nuclear Information System (INIS)

    Lakner, I.; Lestyan, E.

    1979-01-01

    The nuclear power station represents a complicated and a particular industrial project. Consequently, the design of the auxiliary buildings serving the power station (offices, kitchen, refreshment room, workshops, depots, water treatment plant building, boiler houses, etc.) requires more attention than usual. This chapter gives a short survey of the auxiliary buildings already completed and discusses the problems of their design, location and structure. (author)

  13. Seismic dynamic analysis of Heat Exchangers inside of the Auxiliary Buildings in AP1000{sup T}M NPP

    Energy Technology Data Exchange (ETDEWEB)

    Di Fonzo, M.; Aragon, J.; Moraleda, F.; Palazuelos, M.; San vicente, J. L.

    2011-07-01

    Seismic dynamic analysis was carried out for the Heat Exchangers (RNS-HR) located inside of the Auxiliary Building in AP 1000{sup T}M NPP. The main function of the RNS-HX is to provide shutdown reactor cooling. These equipment's are safety-related. So the seismic analysis was done using the methodology for Seismic Category I (SCI) structures. The most important topic is that the RNS-HX shall withstand the effects of the Safe Shutdown Earthquake (SSE) and maintain the specified design functions. for the analysis, two finite element models (FEM) were built in order to investigate the structural response of the couple system of building and equipment. The response spectra method was used. The floor response spectra (FRS) at the slab-wall connection were used as input Lateral seismic restrain was necessary to added in order to achieve the natural frequency of 33 Hz. The global structural response was obtained by means of the modal combination method indicated in the Regulatory Guide 1.92.

  14. Thermal transport properties of helium, helium--air mixtures, water, and tubing steel used in the CACHE program to compute HTGR auxiliary heat exchanger performance

    International Nuclear Information System (INIS)

    Tallackson, J.R.

    1976-02-01

    A description is presented of the thermal transport properties of the materials involved in digital computer calculations of heat transfer rates by the core auxiliary heat exchangers in large HTGR nuclear steam supply systems. These materials are pure helium, mixtures of helium with common gases having molecular weights in the range of 28 to 32, alloy steel tubing, and water. For use in programmed computations the viscosity, thermal conductivity, and specific heat are represented primarily by equations augmented by curves and tabulations. Materials supporting the development and selection of the property equations are included

  15. Treatment of cellulite with a bipolar radiofrequency, infrared heat, and pulsatile suction device: a pilot study.

    Science.gov (United States)

    Wanitphakdeedecha, Rungsima; Manuskiatti, Woraphong

    2006-12-01

    Very few therapeutic options have proven effective in the treatment of cellulite. To evaluate the effectiveness and adverse effects of a bipolar radiofrequency (RF), infrared (IR) heat and pulsatile suction device for the treatment of cellulite. Twelve subjects were treated with the RF-light-based device. All subjects were treated twice weekly for a total number of eight to nine treatments. Subjects were evaluated using standardized photographs, and measurements of body weight and circumference of treatment sites at baseline, immediately after the last treatment, and four weeks and one year after the last treatment. Clinical improvement scores of comparable photographs using a quartile grading scale (0 = 75% improvement) were judged independently by two non-treating dermatologists after the series of treatment. The average body weights at baseline, immediately after the last treatment, and four weeks and one year after the complete treatment were 56.30, 56.05, 56.23, and 56.53 kg, respectively. The average circumferential reductions of the abdomen and thigh at the last treatment visit were 5.17 +/- 1.04 cm (6.32%+/- 1.82%) and 3.50 +/- 2.16 cm (6.23 +/- 3.58%), respectively. At four weeks after the last treatment, the average circumferential reductions of the abdomen and thigh were sustained at 3.17 +/- 2.75 cm (4.04%+/- 3.69%) and 3.50 +/- 2.04 cm (6.26%+/- 3.52%), respectively. At one year follow-up visit, the average circumferential reductions of the abdomen and thigh were maintained at 3.83 +/- 0.76 cm (4.64%+/- 1.15%) and 3.13 +/- 3.54 (5.50%+/- 6.12%), respectively. Average clinical improvement scores of the abdomen and thigh after the series of treatments were 0.75 (corresponding to approximately 25% improvement), and 1.75 (corresponding to approximately 50% improvement), respectively. A bipolar RF, IR heat and pulsatile suction device provides a beneficial effect on reduction of abdomen and thigh circumference, and smoothening of the cellulite.

  16. Cooldown to residual heat removal entry conditions using atmospheric dump valves and auxiliary pressurizer spray following a loss-of-offsite power at Calvert Cliffs, Unit 1

    International Nuclear Information System (INIS)

    Jenks, R.P.

    1984-01-01

    An investigation of cooldown using atmospheric dump valves (ADVs) and auxiliary pressurizer spray (APS) following loss-of-offsite power at Calvert Cliffs-1 showed residual heat removal entry conditions could not be reached with the plant ADVs alone. Use of APS with the plant ADVs enhanced depressurization, but still provided insufficient cooldown. Effective cooldown and depressurization was shown to occur when rated steady state flow through the ADVs was increased by a factor of four. 6 refs., 30 figs., 2 tabs

  17. Citrate-capped gold nanoparticle electrophoretic heat production in response to a time-varying radiofrequency electric-field.

    Science.gov (United States)

    Corr, Stuart J; Raoof, Mustafa; Mackeyev, Yuri; Phounsavath, Sophia; Cheney, Matthew A; Cisneros, Brandon T; Shur, Michael; Gozin, Michael; McNally, Patrick J; Wilson, Lon J; Curley, Steven A

    2012-11-15

    The evaluation of heat production from gold nanoparticles (AuNPs) irradiated with radiofrequency (RF) energy has been problematic due to Joule heating of their background ionic buffer suspensions. Insights into the physical heating mechanism of nanomaterials under RF excitations must be obtained if they are to have applications in fields such as nanoparticle-targeted hyperthermia for cancer therapy. By developing a purification protocol which allows for highly-stable and concentrated solutions of citrate-capped AuNPs to be suspended in high-resistivity water, we show herein, for the first time, that heat production is only evident for AuNPs of diameters ≤ 10 nm, indicating a unique size-dependent heating behavior not previously observed. Heat production has also shown to be linearly dependent on both AuNP concentration and total surface area, and severely attenuated upon AuNP aggregation. These relationships have been further validated using permittivity analysis across a frequency range of 10 MHz to 3 GHz, as well as static conductivity measurements. Theoretical evaluations suggest that the heating mechanism can be modeled by the electrophoretic oscillation of charged AuNPs across finite length scales in response to a time-varying electric field. It is anticipated these results will assist future development of nanoparticle-assisted heat production by RF fields for applications such as targeted cancer hyperthermia.

  18. Auxiliary reactor for a hydrocarbon reforming system

    Science.gov (United States)

    Clawson, Lawrence G.; Dorson, Matthew H.; Mitchell, William L.; Nowicki, Brian J.; Bentley, Jeffrey M.; Davis, Robert; Rumsey, Jennifer W.

    2006-01-17

    An auxiliary reactor for use with a reformer reactor having at least one reaction zone, and including a burner for burning fuel and creating a heated auxiliary reactor gas stream, and heat exchanger for transferring heat from auxiliary reactor gas stream and heat transfer medium, preferably two-phase water, to reformer reaction zone. Auxiliary reactor may include first cylindrical wall defining a chamber for burning fuel and creating a heated auxiliary reactor gas stream, the chamber having an inlet end, an outlet end, a second cylindrical wall surrounding first wall and a second annular chamber there between. The reactor being configured so heated auxiliary reactor gas flows out the outlet end and into and through second annular chamber and conduit which is disposed in second annular chamber, the conduit adapted to carry heat transfer medium and being connectable to reformer reaction zone for additional heat exchange.

  19. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000 Btu/hr...

  20. Auxiliary cooling device for power plant

    International Nuclear Information System (INIS)

    Yamanoi, Kozo.

    1996-01-01

    An auxiliary cooling sea water pipeline for pumping up cooling sea water, an auxiliary cooling sea water pipeline and a primary side of an auxiliary cooling heat exchanger are connected between a sea water taking vessel and a sea water discharge pit. An auxiliary cooling water pump is connected to an auxiliary water cooling pipeline on the second side of the auxiliary cooling heat exchanger. The auxiliary cooling water pipeline is connected with each of auxiliary equipments of a reactor system and each of auxiliary equipments of the turbine system connected to a turbine auxiliary cooling water pipeline in parallel. During ordinary operation of the reactor, heat exchange for each of the auxiliary equipments of the reactor and heat exchange for each of the equipments of the turbine system are conducted simultaneously. Since most portions of the cooling devices of each of the auxiliary equipments of the reactor system and each of the auxiliary equipments of the turbine system can be used in common, the operation efficiency of the cooling device is improved. In addition, the space for the pipelines and the cost for the equipments can be reduced. (I.N.)

  1. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    Acosta, Eduardo; Amaya, Daniel; Carlevaris, Rodolfo; Patrignani, A.; Ramilo, L.; Santecchia, A.; Vindrola, C.

    2000-01-01

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100MWt, about 25MWe).CAREM design is based on light water integrated reactor with slightly enriched uranium.In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented.Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor

  2. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    Acosta, Eduardo; Amaya, Daniel; Carlevaris, Rodolfo; Patrignani, Alberto; Santecchia, Alberto; Vindrola, Carlos; Ramilo, Lucia B.

    2000-01-01

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100 M Wt, about 25 M We). CAREM design is based on light water integrated reactor with slightly enriched uranium. In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented. Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor. (author)

  3. Radiofrequency Neurotomy

    Science.gov (United States)

    ... your specific symptoms. What you can expect Before radiofrequency neurotomy Let your doctor know if you take ... tobacco products the day of your procedure. During radiofrequency neurotomy Radiofrequency neurotomy is an outpatient procedure, so ...

  4. Topics in stability and transport in tokamaks: Dynamic transition to second stability with auxiliary heating; stability of global Alfven waves in an ignited plasma

    International Nuclear Information System (INIS)

    Fu, G.

    1988-01-01

    The problem of access to the high-beta ballooning second-stability regime by means of auxiliary heating and the problem of the stability of global-shear Alfven waves in an ignited tokamak plasma are theoretically investigated. These two problems are related to the confinement of both the bulk plasma as well as the fusion-product alpha particles an dare fundamentally important to the operation of ignited tokamak plasma. First, a model that incorporates both transport and ballooning mode stability was developed in order to estimate the auxiliary heating power required for tokamak plasma to evolve in time self-consistently into a high-beta, globally self-stabilized equilibrium. The critical heating power needed for access to second stability is found to be proportional to the square root of the anomalous diffusivity induced by the ballooning instability. Next, the full effects of toroidicity are retained in a theoretical description of global-type-shear Alfven modes whose stability can be modified by the fusion-product alpha particles that will present in an ignited tokamak plasma. Toroidicity is found to induce mode coupling and to stabilize the so-called Global Alfven Eigenmodes (GAE)

  5. 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)

  6. In Vivo Radiofrequency Heating in Swine in a 3T (123.2 MHz) Birdcage Whole-Body Coil

    Science.gov (United States)

    Shrivastava, Devashish; Utecht, Lynn; Tian, Jinfeng; Hughes, John; Vaughan, J. Thomas

    2014-01-01

    Purpose To study in vivo radiofrequency (RF) heating produced due to power deposition from a 3T (Larmour frequency = 123.2 MHz), birdcage, whole-body coil. Methods The RF heating was simulated in a digital swine by solving the mechanistic generic bioheat transfer model (GBHTM) and the conventional, empirical Pennes bioheat transfer equation for the following two cases: (1) when the porcine head was in the isocenter, and (2) when the porcine trunk was in the isocenter. The simulation results were validated by making direct fluoroptic temperature measurements in the skin, brain, simulated hot regions, and rectum of ten swine (Case 1, N= 5, mean animal weight = 84.03 ± 6.85 kg, Whole-body average SAR = 2.65 ± 0.22 W/kg; Case 2, N= 5, mean animal weight = 81.59 ± 6.23 kg, Whole-body average SAR = 2.77 ± 0.26 W/kg) during one hour of exposure to a turbo spin echo sequence. Results The GBHTM simulated the RF heating more accurately compared to the Pennes equation. In vivo temperatures exceeded safe temperature thresholds with allowable SAR exposures. Hot regions may be produced deep inside the body, away from the skin. Conclusion SAR exposures to produce safe temperature thresholds may need re-investigation. PMID:24259413

  7. In vivo radiofrequency heating in swine in a 3T (123.2-MHz) birdcage whole body coil.

    Science.gov (United States)

    Shrivastava, Devashish; Utecht, Lynn; Tian, Jinfeng; Hughes, John; Vaughan, J Thomas

    2014-10-01

    To study in vivo radiofrequency (RF) heating produced due to power deposition from a 3T (Larmour frequency = 123.2 MHz), birdcage, whole body coil. The RF heating was simulated in a digital swine by solving the mechanistic generic bioheat transfer model (GBHTM) and the conventional, empirical Pennes bioheat transfer equation for two cases: 1) when the swine head was in the isocenter and 2) when the swine trunk was in the isocenter. The simulation results were validated by making direct fluoroptic temperature measurements in the skin, brain, simulated hot regions, and rectum of 10 swine (case 1: n = 5, mean animal weight = 84.03 ± 6.85 kg, whole body average SAR = 2.65 ± 0.22 W/kg; case 2: n = 5, mean animal weight = 81.59 ± 6.23 kg, whole body average SAR = 2.77 ± 0.26 W/kg) during 1 h of exposure to a turbo spin echo sequence. The GBHTM simulated the RF heating more accurately compared with the Pennes equation. In vivo temperatures exceeded safe temperature thresholds with allowable SAR exposures. Hot regions may be produced deep inside the body, away from the skin. SAR exposures that produce safe temperature thresholds need reinvestigation. Copyright © 2013 Wiley Periodicals, Inc.

  8. Mechanical (turbines and auxiliary equipment)

    CERN Document Server

    Sherry, A; Cruddace, AE

    2013-01-01

    Modern Power Station Practice, Volume 3: Mechanical (Turbines and Auxiliary Equipment) focuses on the development of turbines and auxiliary equipment used in power stations in Great Britain. Topics covered include thermodynamics and steam turbine theory; turbine auxiliary systems such as lubrication systems, feed water heating systems, and the condenser and cooling water plants. Miscellaneous station services, and pipework in power plants are also described. This book is comprised of five chapters and begins with an overview of thermodynamics and steam turbine theory, paying particular attenti

  9. Mechanical and microstructural characteristics of meat doughs, either heated by a continuous process in a radio-frequency field or conventionally in a waterbath.

    Science.gov (United States)

    van Roon, P S; Houben, J H; Koolmees, P A; van Vliet, T; Krol, B

    1994-01-01

    Meat doughs, all having the same chemical composition, were pasteurised to a comparable heat intensity (calculated as Cook values: target level of 5 min at 100°C): (i) while flowing through a glass tube (inner diameter 50 mm) mounted in a special radio-frequency (27 MHz) heating section; (ii) after flowing unheated through the glass tube at the same rate and heated in a waterbath; and (iii) after sampling immediately after the pump and heated in a waterbath. The cooked products were sampled in the core and at the rim of the product for rheological (oscillation and uniaxial compression tests at small strain), fracture measurements (uniaxial compression tests at high strain) and microstructural evaluation (light microscopy and video image analysis). Additional core samples were used for a sensory evaluation (triangle tests) of the texture of the differently processed doughs. The fast heating rate (25-30 K/min) at a mass flow of the dough of 100 kg/h (mean velocity 0.014 m/s) during dielectrical pasteurisation affected the mechanical character, the microstructure and the triangle test results of core samples from the sausages, compared to heating in a waterbath. Flow of the unheated dough through the tube of the continuous processing equipment, followed by heating in a waterbath, had little effect on the results of the mechanical tests, the microscopical evaluation and the triangle tests. The radio-frequency heated products had both higher storage and loss moduli (were more firm), fractured at higher stress values and were considered more firm in the sensory evaluation. The microstructure of dielectrically heated versus other samples displayed a more open structure of the protein matrix with larger irregularly shaped fat particles that were surrounded by relatively thin and compact protein bridges. The effects of flow and heating method on the behaviour of rim samples were very similar to their effects on the core of the products. A comparison of the mechanical

  10. Radio-frequency heating and neutral atom transport in a fluid-magnetohydrodynamic treatment of burning tokamak plasmas

    International Nuclear Information System (INIS)

    Conn, R.W.; Mau, T.K.; Prinja, A.K.

    1983-01-01

    A physical model for the space and time evolution of the primary parameters of ordinary and burning tokamak plasmas is described by employing a fluid plasma treatment coupled to a magnetohydrodynamic equilibrium description, the solution to the appropriate Maxwell equations, and the solution of the linear transport equation describing neutral atom transport in plasmas. The specific problems of plasma heating by ion cyclotron radiofrequency (ICRF) waves and neutral atom transport in the plasma edge and in complicated geometrical components such as divertor channels or pumped limiter structures are analyzed. A theoretical, onedimensional slab model of ICRF heating at ω = 2ω/SUB cD/ is developed and applied to determine the space-time response of tokamak plasmas. Generally, strong single-pass absorption is found for high-density, high (β) plasmas using a low k 11 spectrum (0.05 to 0.1 cm -1 ) although for (β > 1%, electron Landau damping becomes important. Deterministic and Monte Carlo methods to solve the neutral atom transport problem are described. Specific application to determine the spectrum of neutral atoms emerging from the duct of a pump limiter shows it to be hard (mean energy > 20 eV), indicating very incomplete energy thermalization. Uncertainties are identified in the overall problem of dynamic burning plasma analysis caused by the complexity of the problem itself and by uncertainties in fundamental areas such as plasma transport coefficients, stability, and plasma edge physics

  11. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities.

    Science.gov (United States)

    Dhakal, Pashupati; Ciovati, Gianluigi; Rigby, Wayne; Wallace, John; Myneni, Ganapati Rao

    2012-06-01

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low (∼120 °C) and high (∼800 °C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 °C with a maximum pressure of ∼1 × 10(-5) Torr and the maximum achievable temperature is estimated to be higher than 2000 °C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 °C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of ∼2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  12. Proceedings of the workshop of three large tokamak cooperation on energy confinement scaling under intensive auxiliary heating, May 18 ∼ 20, 1992, Naka

    International Nuclear Information System (INIS)

    1992-09-01

    The workshop of three large tokamak cooperation W22 on 'Energy confinement scaling under intensive auxiliary heating' was held 18-20 May, 1992, at Naka Fusion Research Establishment. This proceedings compiles 14 synopses of contributions (5 from JET, 4 from JT-60, 3 from TFTR, and 1 each from DIII-D JFT-2M) and the summary of the workshop. Topic sections are ; (i) L-mode confinement and scaling, (ii) Confinement at high β P regimes, Supershots, High poloidal beta enhanced confinement mode etc., (iii) Confinement at various H-mode regimes and scaling (including the VH-mode), (iv) Characteristic time scales for present tokamak regimes, and (v) Theoretical comparison with experimental data. (author)

  13. Effects of auxiliary heat sources on energy efficiency of active solar heating systems%辅助热源对主动式太阳能供暖系统节能性的影响

    Institute of Scientific and Technical Information of China (English)

    于国清; 周继瑞

    2015-01-01

    According to the solar fraction and the energy efficiency of auxiliary heating equipments, analyses the effects of different auxiliary heat sources on the energy efficiency of active solar heating systems by converting energy consumption to primary energy,and believes that the active solar heating system must satisfy certain conditions for achieving energy saving effect.The results indicate that the auxiliary heat source and the solar fraction have a great impact on the energy efficiency of solar heating systems.Compared to the gas-fired boiler heating alone,the solar heating system assisted by electric heating is energy efficient only when the solar fraction is greater than 65.4%,which is very difficult to achieve for many real systems.The primary energy consumption of the solar heating system assisted by heat pump is lower in general instances (when the average COP of heat pump is 2.5,the solar fraction should be greater than 7%).When heat pumps with average COP above 3.0 or gas-fired boilers are used as auxiliary heat sources,the solar heating system is energy efficient,and the higher the solar fraction is,the more obvious the energy saving effect is.%根据太阳能贡献率和辅助加热设备的能源效率,将系统的能耗折算成一次能源,分析不同辅助热源对太阳能供暖系统节能性的影响,认为主动式太阳能供暖系统要达到节能效果必须满足一定的前提条件。研究结果表明:辅助热源方式和太阳能贡献率对系统的节能性影响很大;相对于燃气锅炉单独供暖,电加热辅助太阳能供暖系统只有在太阳能贡献率高于65.4%时才节能,而大多数系统的太阳能贡献率很难达到这么高,因此要尽量避免使用;热泵辅助太阳能供暖系统在大多数情况下都是节能的(热泵的平均 COP =2.5时,太阳能贡献率需高于7%);采用平均COP 高于3.0的热泵或采用燃气锅炉作为辅助热源时,系统都是节

  14. Radiofrequency radiation

    International Nuclear Information System (INIS)

    Elder, J.A.; Czerski, P.A.; Stuchly, M.A.; Mild, K.H.; Sheppard, A.R.

    1989-01-01

    High-level radiofrequency radiation is a source of thermal energy that carries all of the known implications of heating for biological systems, including burns, temporary and permanent changes in reproduction, cataracts, and death. In general, no changes in chromosomes, DNA or the reproductive potential of animals exposed to RF radiation have been reported in the absence of significant rises in temperature, though there are limited data on DNA and chromosomal changes at non-thermal levels. Human data are currently limited and do not provide adequate information about the relationship between prolonged low-level RF radiation exposure and increased mortality or morbidity, including cancer incidence. In epidemiological studies and clinical reports of RF effects in man, the problems of quantification are numerous and include uncertainties about ''dose'', health effects, latent periods, dose-response relationships, and interactions with other physical or chemical agents. 228 refs, 6 figs, 2 tabs

  15. Efficacy and limitations of hyperthermia using a 13.56 MHz radiofrequency capacitive heating system

    International Nuclear Information System (INIS)

    Kawamori, Jiro; Ito, Hideo; Kato, Ken-ichi; Hayasaka, Kazumasa; Saito, Tsutomu; Urahashi, Shingo; Tanaka, Yoshiaki

    1996-01-01

    Between August 1989 and June 1995, 123 patients were treated with hyperthermia using a 13.56 MHz RF capacitive heating system (HEH 500C/OMRON). Hyperthermia was combined with radiation therapy in 103 patients, with radiochemotherapy in 15 patients, with chemotherapy in 3 patients, and was used in 2 patients. Among the 123 patients, 92 completed hyperthermia and the remaining 31 discontinued it. Of these 31 patients, hyperthermia was discontinued because of local pain during heating in 22 cases and because of the poor general condition the remaining 9 patients. The initial response rate of the 92 patients completing therapy was 54.3%. CR, PR, NC and PD were achieved in 15, 35, 37, and 5 case, respectively. Initial response rates for head/neck, breast, and bone/soft tissue tumors were better than for other primary sites. The initial response rate for superficial tumors was better than that for deep seated tumors. Prognostic factors that significantly influenced the initial response rate were the radiation dose, number of heating sessions, tumor histology, and primary site. Concerning pain during heating, severe pain or discontinuation due to pain occurred were observed in 49 cases (39.8%). The factors having a significant correlation with pain during heating were applicator arrangement, applicator size, heating site, and tumor depth. In 24 patients, erosions or ulcers occurred (27.2%). The factors having a significant correlation with acute skin reactions, were applicator arrangement, applicator size, radiation therapy, tumor depth, and proximity to bone. In 12 cases, fat necrosis was observed (13%). Multiple regression analysis showed that the thickness of the subcutaneous fat, and the applicator arrangement had a significant correlation with the occurrence of fat necrosis. (K.H.)

  16. Effect of variable heat transfer coefficient on tissue temperature next to a large vessel during radiofrequency tumor ablation

    Directory of Open Access Journals (Sweden)

    Pinheiro Cleber

    2008-07-01

    Full Text Available Abstract Background One of the current shortcomings of radiofrequency (RF tumor ablation is its limited performance in regions close to large blood vessels, resulting in high recurrence rates at these locations. Computer models have been used to determine tissue temperatures during tumor ablation procedures. To simulate large vessels, either constant wall temperature or constant convective heat transfer coefficient (h have been assumed at the vessel surface to simulate convection. However, the actual distribution of the temperature on the vessel wall is non-uniform and time-varying, and this feature makes the convective coefficient variable. Methods This paper presents a realistic time-varying model in which h is a function of the temperature distribution at the vessel wall. The finite-element method (FEM was employed in order to model RF hepatic ablation. Two geometrical configurations were investigated. The RF electrode was placed at distances of 1 and 5 mm from a large vessel (10 mm diameter. Results When the ablation procedure takes longer than 1–2 min, the attained coagulation zone obtained with both time-varying h and constant h does not differ significantly. However, for short duration ablation (5–10 s and when the electrode is 1 mm away from the vessel, the use of constant h can lead to errors as high as 20% in the estimation of the coagulation zone. Conclusion For tumor ablation procedures typically lasting at least 5 min, this study shows that modeling the heat sink effect of large vessels by applying constant h as a boundary condition will yield precise results while reducing computational complexity. However, for other thermal therapies with shorter treatment using a time-varying h may be necessary.

  17. Modeling of sawtooth destabilization during radio-frequency heating experiments in tokamak plasmas

    International Nuclear Information System (INIS)

    McClements, K.G.; Dendy, R.O.; Hastie, R.J.; Martin, T.J.

    1996-01-01

    Sawtooth oscillations in tokamaks have been stabilized using ion cyclotron resonance heating (ICRH), but often reappear while ICRH continues. It is shown that the reappearance of sawteeth during one particular ICRH discharge in the Joint European Torus (JET) [Campbell et al., Phys. Rev. Lett. 60, 2148 (1988)] was correlated with a change of sign in the energy δW associated with m=1 internal kink displacements. To compute δW, a new analytical model is used for the distribution function of heated minority ions, which is consistent with Fokker endash Planck simulations of ICRH. Minority ions have a stabilizing influence, arising from third adiabatic invariant conservation, but also contribute to a destabilizing shift of magnetic flux surfaces. As the minor radius of the q=1 surface rises, the stabilizing influence of minority ions diminishes, and the shape of the plasma cross section becomes increasingly important. It is shown that an increase in ICRH power can destabilize the kink mode: this is consistent with observations of sawteeth in JET discharges with varying levels of ICRH. It is suggested that the sawtooth-free period could be prolonged by minimizing the vertical extent of the ICRH power deposition profile.1996 American Institute of Physics

  18. The T-lock: automated compensation of radio-frequency induced sample heating

    International Nuclear Information System (INIS)

    Hiller, Sebastian; Arthanari, Haribabu; Wagner, Gerhard

    2009-01-01

    Modern high-field NMR spectrometers can stabilize the nominal sample temperature at a precision of less than 0.1 K. However, the actual sample temperature may differ from the nominal value by several degrees because the sample heating caused by high-power radio frequency pulses is not readily detected by the temperature sensors. Without correction, transfer of chemical shifts between different experiments causes problems in the data analysis. In principle, the temperature differences can be corrected by manual procedures but this is cumbersome and not fully reliable. Here, we introduce the concept of a 'T-lock', which automatically maintains the sample at the same reference temperature over the course of different NMR experiments. The T-lock works by continuously measuring the resonance frequency of a suitable spin and simultaneously adjusting the temperature control, thus locking the sample temperature at the reference value. For three different nuclei, 13 C, 17 O and 31 P in the compounds alanine, water, and phosphate, respectively, the T-lock accuracy was found to be <0.1 K. The use of dummy scan periods with variable lengths allows a reliable establishment of the thermal equilibrium before the acquisition of an experiment starts

  19. Assessment of magnetic field interactions and radiofrequency-radiation-induced heating of metallic spinal implants in 7 T field.

    Science.gov (United States)

    Tsukimura, Itsuko; Murakami, Hideki; Sasaki, Makoto; Endo, Hirooki; Yamabe, Daisuke; Oikawa, Ryosuke; Doita, Minoru

    2017-08-01

    The safety of metallic spinal implants in magnetic resonance imaging (MRI) performed using ultrahigh fields has not been established. Hence, we examined whether the displacement forces caused by a static magnetic field and the heating induced by radiofrequency radiation are substantial for spinal implants in a 7 T field. We investigated spinal rods of various lengths and materials, a screw, and a cross-linking bridge in accordance with the American Society for Testing and Materials guidelines. The displacement forces of the metallic implants in static 7 T and 3 T static magnetic fields were measured and compared. The temperature changes of the implants during 15-min-long fast spin-echo and balanced gradient-echo image acquisition sequences were measured in the 7 T field. The deflection angles of the metallic spinal materials in the 7 T field were 5.0-21.0° [median: 6.7°], significantly larger than those in the 3 T field (1.0-6.3° [2.2°]). Among the metallic rods, the cobalt-chrome rods had significantly larger deflection angles (17.8-21.0° [19.8°]) than the pure titanium and titanium alloy rods (5.0-7.7° [6.2°]). The temperature changes of the implants, including the cross-linked rods, were 0.7-1.0°C [0.8°C] and 0.6-1.0°C [0.7°C] during the fast spin-echo and balanced gradient-echo sequences, respectively; these changes were slightly larger than those of the controls (0.4-1.1°C [0.5°C] and 0.3-0.9°C [0.6°C], respectively). All of the metallic spinal implants exhibited small displacement forces and minimal heating, indicating that MRI examinations using 7 T fields may be performed safely on patients with these implants. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:1831-1837, 2017. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society.

  20. Investigation of Parallel Radiofrequency Transmission for the Reduction of Heating in Long Conductive Leads in 3 Tesla Magnetic Resonance Imaging.

    Directory of Open Access Journals (Sweden)

    Clare E McElcheran

    Full Text Available Deep Brain Stimulation (DBS is increasingly used to treat a variety of brain diseases by sending electrical impulses to deep brain nuclei through long, electrically conductive leads. Magnetic resonance imaging (MRI of patients pre- and post-implantation is desirable to target and position the implant, to evaluate possible side-effects and to examine DBS patients who have other health conditions. Although MRI is the preferred modality for pre-operative planning, MRI post-implantation is limited due to the risk of high local power deposition, and therefore tissue heating, at the tip of the lead. The localized power deposition arises from currents induced in the leads caused by coupling with the radiofrequency (RF transmission field during imaging. In the present work, parallel RF transmission (pTx is used to tailor the RF electric field to suppress coupling effects. Electromagnetic simulations were performed for three pTx coil configurations with 2, 4, and 8-elements, respectively. Optimal input voltages to minimize coupling, while maintaining RF magnetic field homogeneity, were determined for all configurations using a Nelder-Mead optimization algorithm. Resulting electric and magnetic fields were compared to that of a 16-rung birdcage coil. Experimental validation was performed with a custom-built 4-element pTx coil. In simulation, 95-99% reduction of the electric field at the tip of the lead was observed between the various pTx coil configurations and the birdcage coil. Maximal reduction in E-field was obtained with the 8-element pTx coil. Magnetic field homogeneity was comparable to the birdcage coil for the 4- and 8-element pTx configurations. In experiment, a temperature increase of 2±0.15°C was observed at the tip of the wire using the birdcage coil, whereas negligible increase (0.2±0.15°C was observed with the optimized pTx system. Although further research is required, these initial results suggest that the concept of optimizing p

  1. Investigation of Parallel Radiofrequency Transmission for the Reduction of Heating in Long Conductive Leads in 3 Tesla Magnetic Resonance Imaging.

    Science.gov (United States)

    McElcheran, Clare E; Yang, Benson; Anderson, Kevan J T; Golenstani-Rad, Laleh; Graham, Simon J

    2015-01-01

    Deep Brain Stimulation (DBS) is increasingly used to treat a variety of brain diseases by sending electrical impulses to deep brain nuclei through long, electrically conductive leads. Magnetic resonance imaging (MRI) of patients pre- and post-implantation is desirable to target and position the implant, to evaluate possible side-effects and to examine DBS patients who have other health conditions. Although MRI is the preferred modality for pre-operative planning, MRI post-implantation is limited due to the risk of high local power deposition, and therefore tissue heating, at the tip of the lead. The localized power deposition arises from currents induced in the leads caused by coupling with the radiofrequency (RF) transmission field during imaging. In the present work, parallel RF transmission (pTx) is used to tailor the RF electric field to suppress coupling effects. Electromagnetic simulations were performed for three pTx coil configurations with 2, 4, and 8-elements, respectively. Optimal input voltages to minimize coupling, while maintaining RF magnetic field homogeneity, were determined for all configurations using a Nelder-Mead optimization algorithm. Resulting electric and magnetic fields were compared to that of a 16-rung birdcage coil. Experimental validation was performed with a custom-built 4-element pTx coil. In simulation, 95-99% reduction of the electric field at the tip of the lead was observed between the various pTx coil configurations and the birdcage coil. Maximal reduction in E-field was obtained with the 8-element pTx coil. Magnetic field homogeneity was comparable to the birdcage coil for the 4- and 8-element pTx configurations. In experiment, a temperature increase of 2±0.15°C was observed at the tip of the wire using the birdcage coil, whereas negligible increase (0.2±0.15°C) was observed with the optimized pTx system. Although further research is required, these initial results suggest that the concept of optimizing pTx to reduce DBS

  2. Research and Development of a New Field Enhanced Low Temperature Thermionic Cathode that Enables Fluorescent Dimming and Loan Shedding without Auxiliary Cathode Heating

    Energy Technology Data Exchange (ETDEWEB)

    Feng Jin

    2009-01-07

    This is the final report for project entitled 'Research and development of a new field enhanced low temperature thermionic cathode that enables fluorescent dimming and load shedding without auxiliary cathode heating', under Agreement Number: DE-FC26-04NT-42329. Under this project, a highly efficient CNT based thermionic cathode was demonstrated. This cathode is capable of emitting electron at a current density two order of magnitude stronger then a typical fluorescent cathode at same temperatures, or capable of emitting at same current density but at temperature about 300 C lower than that of a fluorescent cathode. Detailed fabrication techniques were developed including CVD growth of CNTs and sputter deposition of oxide thin films on CNTs. These are mature technologies that have been widely used in industry for large scale materials processing and device fabrications, thus, with further development work, the techniques developed in this project can be scaled-up in manufacturing environment. The prototype cathodes developed in this project were tested in lighting plasma discharge environment. In many cases, they not only lit and sustain the plasma, but also out perform the fluorescent cathodes in key parameters such like cathode fall voltages. More work will be needed to further evaluate more detailed and longer term performance of the prototype cathode in lighting plasma.

  3. Effect of high temperature heat treatments on the quality factor of a large-grain superconducting radio-frequency niobium cavity

    Directory of Open Access Journals (Sweden)

    P. Dhakal

    2013-04-01

    Full Text Available Large-grain Nb has become a viable alternative to fine-grain Nb for the fabrication of superconducting radio-frequency cavities. In this contribution we report the results from a heat treatment study of a large-grain 1.5 GHz single-cell cavity made of “medium purity” Nb. The baseline surface preparation prior to heat treatment consisted of standard buffered chemical polishing. The heat treatment in the range 800–1400°C was done in a newly designed vacuum induction furnace. Q_{0} values of the order of 2×10^{10} at 2.0 K and peak surface magnetic field (B_{p} of 90 mT were achieved reproducibly. A Q_{0} value of (5±1×10^{10} at 2.0 K and B_{p}=90  mT was obtained after heat treatment at 1400°C. This is the highest value ever reported at this temperature, frequency, and field. Samples heat treated with the cavity at 1400°C were analyzed by secondary ion mass spectrometry, x-ray photoelectron spectroscopy, energy dispersive x ray, point-contact tunneling, and x-ray diffraction, and revealed a complex surface composition which includes titanium oxide, increased carbon, and nitrogen content but reduced hydrogen concentration compared to a non-heat-treated sample.

  4. Effect of high temperature heat treatments on the quality factor of a large-grain superconducting radio-frequency niobium cavity

    Science.gov (United States)

    Dhakal, P.; Ciovati, G.; Myneni, G. R.; Gray, K. E.; Groll, N.; Maheshwari, P.; McRae, D. M.; Pike, R.; Proslier, T.; Stevie, F.; Walsh, R. P.; Yang, Q.; Zasadzinzki, J.

    2013-04-01

    Large-grain Nb has become a viable alternative to fine-grain Nb for the fabrication of superconducting radio-frequency cavities. In this contribution we report the results from a heat treatment study of a large-grain 1.5 GHz single-cell cavity made of “medium purity” Nb. The baseline surface preparation prior to heat treatment consisted of standard buffered chemical polishing. The heat treatment in the range 800-1400°C was done in a newly designed vacuum induction furnace. Q0 values of the order of 2×1010 at 2.0 K and peak surface magnetic field (Bp) of 90 mT were achieved reproducibly. A Q0 value of (5±1)×1010 at 2.0 K and Bp=90mT was obtained after heat treatment at 1400°C. This is the highest value ever reported at this temperature, frequency, and field. Samples heat treated with the cavity at 1400°C were analyzed by secondary ion mass spectrometry, x-ray photoelectron spectroscopy, energy dispersive x ray, point-contact tunneling, and x-ray diffraction, and revealed a complex surface composition which includes titanium oxide, increased carbon, and nitrogen content but reduced hydrogen concentration compared to a non-heat-treated sample.

  5. Effect of high temperature heat treatments on the quality factor of a large-grain superconducting radio-frequency niobium cavity

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, P.; Ciovati, G.; Myneni, G. R.; Gray, K. E.; Groll, N.; Maheshwari, P.; McRae, D. M.; Pike, R.; Proslier, T.; Stevie, F.; Walsh, R. P.; Yang, Q.; Zasadzinzki, J.

    2013-04-01

    Large-grain Nb has become a viable alternative to fine-grain Nb for the fabrication of superconducting radio-frequency cavities. In this contribution we report the results from a heat treatment study of a large-grain 1.5 GHz single-cell cavity made of “medium purity” Nb. The baseline surface preparation prior to heat treatment consisted of standard buffered chemical polishing. The heat treatment in the range 800–1400°C was done in a newly designed vacuum induction furnace. Q{sub 0} values of the order of 2×10{sup 10} at 2.0 K and peak surface magnetic field (B{sub p}) of 90 mT were achieved reproducibly. A Q{sub 0} value of (5±1)×10{sup 10} at 2.0 K and B{sub p}=90mT was obtained after heat treatment at 1400°C. This is the highest value ever reported at this temperature, frequency, and field. Samples heat treated with the cavity at 1400°C were analyzed by secondary ion mass spectrometry, x-ray photoelectron spectroscopy, energy dispersive x ray, point-contact tunneling, and x-ray diffraction, and revealed a complex surface composition which includes titanium oxide, increased carbon, and nitrogen content but reduced hydrogen concentration compared to a non-heat-treated sample.

  6. A hybrid geothermal energy conversion technology: Auxiliary heating of geothermally preheated water or CO2 - a potential solution for low-temperature resources

    Science.gov (United States)

    Saar, Martin; Garapati, Nagasree; Adams, Benjamin; Randolph, Jimmy; Kuehn, Thomas

    2016-04-01

    compare over a range of parameters the net power and efficiencies of hybrid geothermal power plants that use brine or CO2 as the subsurface working fluid, that are then heated further with a secondary energy source that is unspecified here. Parameters varied include the subsurface working fluid (brine vs. CO2), geothermal reservoir depth (2.5-4.5 km), and turbine inlet temperature (200-600°C) after auxiliary heating. The hybrid power plant is numerically modeled using an iterative coupling approach of TOUGH2-ECO2N/ECO2H (Pruess, 2004) for simulation of the subsurface reservoir and Engineering Equation Solver for well bore fluid flow and surface power plant performance. We find that hybrid power plants that are CO2-based (subsurface) systems produce more net power than the sum of the power produced by individual power plants at low turbine inlet temperatures and brine based systems produce more power at high turbine inlet temperatures. Specifically, our results indicate that geothermal hybrid plants that are CO2-based are more efficient than brine-based systems when the contribution of the geothermal resource energy is higher than 48%.

  7. Auxiliary verbs in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2007-01-01

    Dinka, a Western Nilotic language, has a class of auxiliary verbs which is remarkable in the following four respects: (i) It is unusually large, comprising some 20 members; (ii) it is grammatically homogeneous in terms of both morphology and syntax; (iii) most of the auxiliary verbs correspond...... to adverbs in languages like English, while the rest are tense-aspect markers; and (iv) it is possible to combine several auxiliary verbs in a single clause. For some of the auxiliary verbs there are extant full verbs from which they have evolved. To some extent, therefore, it is possible to observe what...

  8. Window-mounted auxiliary solar heater

    Science.gov (United States)

    Anthony, K. G.; Herndon, E. P.

    1977-01-01

    System uses hot-air collectors, no thermal storage, and fan with thermostat switches. At cost of heating efficiency, unit could be manufactured and sold at price allowing immediate entry to market as auxiliary heating system. Its simplicity allows homeowner installation, and maintenance is minimal.

  9. Non-surgical radiofrequency facelift.

    Science.gov (United States)

    Narins, David J; Narins, Rhoda S

    2003-10-01

    There has been considerable interest in using non-ablative methods to rejuvenate the skin. The ThermaCool TC (Thermage Inc.) is a radiofrequency (RF) device that has been introduced to induce tightening of the address the problem of skin via a uniform volumetric heating into the deep dermis tightening, resulting in a 'non-surgical facelift'. Radiofrequency produces a uniform volumetric heating into the deep dermis. Twenty treatment areas in 17 patients were treated to evaluate the efficacy and safety of RF treatment to the brow and jowls. The technique was found to produce gradual tightening in most patients, and there were no adverse effects.

  10. Steam generator auxiliary systems

    International Nuclear Information System (INIS)

    Heinz, A.

    1982-01-01

    The author deals with damage and defect types obtaining in auxiliary systems of power plants. These concern water/steam auxiliary systems (feed-water tank, injection-control valves, slide valves) and air/fluegas auxiliary systems (blowers, air preheaters, etc.). Operating errors and associated damage are not dealt with; by contrast, weak spots are pointed out which result from planning and design. Damage types and events are collected in statistics in order to facilitate damage evaluation for arriving at improved design solutions. (HAG) [de

  11. Nuclear reactors with auxiliary boiler circuit

    International Nuclear Information System (INIS)

    George, B.V.; Cook, R.K.

    1976-01-01

    A gas-cooled nuclear reactor has a main circulatory system for the gaseous coolant incorporating one or more main energy converting units, such as gas turbines, and an auxiliary circulatory system for the gaseous coolant incorporating at least one steam generating boiler arranged to be heated by the coolant after its passage through the reactor core to provide steam for driving an auxiliary steam turbine, such an arrangement providing a simplified start-up procedure also providing emergency duties associated with long term heat removal on reactor shut down

  12. Non-isothermal decomposition kinetics, heat capacity and thermal safety of 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture

    International Nuclear Information System (INIS)

    Zhang, Jiao-Qiang; Gao, Hong-Xu; Ji, Tie-Zheng; Xu, Kang-Zhen; Hu, Rong-Zu

    2011-01-01

    Highlights: → Non-isothermal decomposition kinetics, heat capacity and thermal safety on 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture. → Apparent activation energy and pre-exponential constant obtained. → Thermal explosion temperature, adiabatic time-to-explosion, 50% drop height of impact sensitivity, and critical temperature of hot-spot initiation calculated. - Abstract: The specific heat capacity (C p ) of 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was determined with the continuous C p mode of microcalorimeter. The equation of C p with temperature was obtained. The standard molar heat capacity of GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was 1.225 J mol -1 K -1 at 298.15 K. With the help of the peak temperature (T p ) from the non-isothermal DTG curves of the mixture at different heating rates (β), the apparent activation energy (E k and E o ) and pre-exponential constant (A K ) of thermal decomposition reaction obtained by Kissinger's method and Ozawa's method. Using density (ρ) and thermal conductivity (λ), the decomposition heat (Q d , taking half-explosion heat), Zhang-Hu-Xie-Li's formula, the values (T e0 and T p0 ) of T e and T p corresponding to β → 0, thermal explosion temperature (T be and T bp ), adiabatic time-to-explosion (t TIad ), 50% drop height (H 50 ) of impact sensitivity, and critical temperature of hot-spot initiation (T cr,hotspot ) of thermal explosion of the mixture were calculated. The following results of evaluating the thermal safety of the mixture were obtained: T be = 441.64 K, T bp = 461.66 K, t Tlad = 78.0 s (n = 2), t Tlad = 74.87s (n = 1), t Tlad = 71.85 s (n = 0), H 50 = 21.33 cm.

  13. Uncertainties in the estimation of specific absorption rate during radiofrequency alternating magnetic field induced non-adiabatic heating of ferrofluids

    Science.gov (United States)

    Lahiri, B. B.; Ranoo, Surojit; Philip, John

    2017-11-01

    Magnetic fluid hyperthermia (MFH) is becoming a viable cancer treatment methodology where the alternating magnetic field induced heating of magnetic fluid is utilized for ablating the cancerous cells or making them more susceptible to the conventional treatments. The heating efficiency in MFH is quantified in terms of specific absorption rate (SAR), which is defined as the heating power generated per unit mass. In majority of the experimental studies, SAR is evaluated from the temperature rise curves, obtained under non-adiabatic experimental conditions, which is prone to various thermodynamic uncertainties. A proper understanding of the experimental uncertainties and its remedies is a prerequisite for obtaining accurate and reproducible SAR. Here, we study the thermodynamic uncertainties associated with peripheral heating, delayed heating, heat loss from the sample and spatial variation in the temperature profile within the sample. Using first order approximations, an adiabatic reconstruction protocol for the measured temperature rise curves is developed for SAR estimation, which is found to be in good agreement with those obtained from the computationally intense slope corrected method. Our experimental findings clearly show that the peripheral and delayed heating are due to radiation heat transfer from the heating coils and slower response time of the sensor, respectively. Our results suggest that the peripheral heating is linearly proportional to the sample area to volume ratio and coil temperature. It is also observed that peripheral heating decreases in presence of a non-magnetic insulating shielding. The delayed heating is found to contribute up to ~25% uncertainties in SAR values. As the SAR values are very sensitive to the initial slope determination method, explicit mention of the range of linear regression analysis is appropriate to reproduce the results. The effect of sample volume to area ratio on linear heat loss rate is systematically studied and the

  14. Uncertainties in the estimation of specific absorption rate during radiofrequency alternating magnetic field induced non-adiabatic heating of ferrofluids

    International Nuclear Information System (INIS)

    Lahiri, B B; Ranoo, Surojit; Philip, John

    2017-01-01

    Magnetic fluid hyperthermia (MFH) is becoming a viable cancer treatment methodology where the alternating magnetic field induced heating of magnetic fluid is utilized for ablating the cancerous cells or making them more susceptible to the conventional treatments. The heating efficiency in MFH is quantified in terms of specific absorption rate (SAR), which is defined as the heating power generated per unit mass. In majority of the experimental studies, SAR is evaluated from the temperature rise curves, obtained under non-adiabatic experimental conditions, which is prone to various thermodynamic uncertainties. A proper understanding of the experimental uncertainties and its remedies is a prerequisite for obtaining accurate and reproducible SAR. Here, we study the thermodynamic uncertainties associated with peripheral heating, delayed heating, heat loss from the sample and spatial variation in the temperature profile within the sample. Using first order approximations, an adiabatic reconstruction protocol for the measured temperature rise curves is developed for SAR estimation, which is found to be in good agreement with those obtained from the computationally intense slope corrected method. Our experimental findings clearly show that the peripheral and delayed heating are due to radiation heat transfer from the heating coils and slower response time of the sensor, respectively. Our results suggest that the peripheral heating is linearly proportional to the sample area to volume ratio and coil temperature. It is also observed that peripheral heating decreases in presence of a non-magnetic insulating shielding. The delayed heating is found to contribute up to ∼25% uncertainties in SAR values. As the SAR values are very sensitive to the initial slope determination method, explicit mention of the range of linear regression analysis is appropriate to reproduce the results. The effect of sample volume to area ratio on linear heat loss rate is systematically studied and

  15. A novel non-invasive radiofrequency dermal heating device for skin tightening of the face and neck.

    Science.gov (United States)

    Nelson, Andrew A; Beynet, David; Lask, Gary P

    2015-01-01

    Loose, lax skin is a common cosmetic complaint. Previous non-invasive skin tightening devices had modest efficacy and were associated with pain or downtime. New technologies may allow for effective skin tightening with a series of radiofrequency (RF) treatments with no downtime. To evaluate the efficacy and safety of a novel bipolar RF device for skin tightening. Fifteen consecutive female patients were enrolled in the case series; 14 completed the study and were included in the analysis. The device under investigation is a novel, bipolar RF device allowing for achievement and maintenance of optimal dermal temperatures to stimulate collagen remodeling and skin tightening. Patients underwent a series of 4-6 weekly treatments. Three blinded, experienced cosmetic physicians evaluated paired pre-treatment and post-treatment photographs and determined the associated improvement, if any. All patients (14/14) were determined to have a clinical improvement, as the pre-treatment and post-treatment photographs were correctly identified by the evaluators. It was observed that 21% (3/14) of patients had significant improvement, 50% (7/14) had moderate improvement, and 29% (4/14) had mild improvement. No pain, side effects, or adverse events were observed. This novel bipolar RF device represents a safe, effective treatment option for non-invasive skin tightening.

  16. Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave...... the generative model unchanged but make the variational distribution more expressive. Inspired by the structure of the auxiliary variable we also propose a model with two stochastic layers and skip connections. Our findings suggest that more expressive and properly specified deep generative models converge...... faster with better results. We show state-of-the-art performance within semi-supervised learning on MNIST (0.96%), SVHN (16.61%) and NORB (9.40%) datasets....

  17. Auxiliary mine ventilation manual

    International Nuclear Information System (INIS)

    Workplace Safety North

    2010-01-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  18. Auxiliary mine ventilation manual

    Energy Technology Data Exchange (ETDEWEB)

    Workplace Safety North

    2010-07-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  19. Auxiliary partial liver transplantation

    NARCIS (Netherlands)

    C.B. Reuvers (Cornelis Bastiaan)

    1986-01-01

    textabstractIn this thesis studies on auxiliary partial liver transplantation in the dog and the pig are reported. The motive to perform this study was the fact that patients with acute hepatic failure or end-stage chronic liver disease are often considered to form too great a risk for successful

  20. PS auxiliary magnet

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    Units of the PS auxiliary magnet system. The picture shows how the new dipoles, used for vertical and horizontal high-energy beam manipulation, are split for installation and removal so that it is not necessary to break the accelerator vacuum. On the right, adjacent to the sector valve and the windings of the main magnet, is an octupole of the set.

  1. Operation auxiliary system (SAO)

    International Nuclear Information System (INIS)

    Lolich, J.; Santome, D.; Drexler, J.

    1990-01-01

    This work presents an auxiliary system for nuclear power plants operation (SAO). The development purpose consisted in a computing supervision system to be installed at different sites of a reactor, mainly in the control room. The inclusion of this system to a nuclear power plant minimizes the possibility of human error for the facility operation. (Author) [es

  2. Stochastic heating of a single Brownian particle by charge fluctuations in a radio-frequency produced plasma sheath

    Science.gov (United States)

    Schmidt, Christian; Piel, Alexander

    2015-10-01

    The Brownian motion of a single particle in the plasma sheath is studied to separate the effect of stochastic heating by charge fluctuations from heating by collective effects. By measuring the particle velocities in the ballistic regime and by carefully determining the particle mass from the Epstein drag it is shown that for a pressure of 10 Pa, which is typical of many experiments, the proper kinetic temperature of the Brownian particle remains close to the gas temperature and rises only slightly with particle size. This weak effect is confirmed by a detailed model for charging and charge fluctuations in the sheath. A substantial temperature rise is found for decreasing pressure, which approximately shows the expected scaling with p-2. The system under study is an example for non-equilibrium Brownian motion under the influence of white noise without corresponding dissipation.

  3. Computer modeling of the combined effects of perfusion, electrical conductivity, and thermal conductivity on tissue heating patterns in radiofrequency tumor ablation.

    Science.gov (United States)

    Ahmed, Muneeb; Liu, Zhengjun; Humphries, Stanley; Goldberg, S Nahum

    2008-11-01

    To use an established computer simulation model of radiofrequency (RF) ablation to characterize the combined effects of varying perfusion, and electrical and thermal conductivity on RF heating. Two-compartment computer simulation of RF heating using 2-D and 3-D finite element analysis (ETherm) was performed in three phases (n = 88 matrices, 144 data points each). In each phase, RF application was systematically modeled on a clinically relevant template of application parameters (i.e., varying tumor and surrounding tissue perfusion: 0-5 kg/m(3)-s) for internally cooled 3 cm single and 2.5 cm cluster electrodes for tumor diameters ranging from 2-5 cm, and RF application times (6-20 min). In the first phase, outer thermal conductivity was changed to reflect three common clinical scenarios: soft tissue, fat, and ascites (0.5, 0.23, and 0.7 W/m- degrees C, respectively). In the second phase, electrical conductivity was changed to reflect different tumor electrical conductivities (0.5 and 4.0 S/m, representing soft tissue and adjuvant saline injection, respectively) and background electrical conductivity representing soft tissue, lung, and kidney (0.5, 0.1, and 3.3 S/m, respectively). In the third phase, the best and worst combinations of electrical and thermal conductivity characteristics were modeled in combination. Tissue heating patterns and the time required to heat the entire tumor +/-a 5 mm margin to >50 degrees C were assessed. Increasing background tissue thermal conductivity increases the time required to achieve a 50 degrees C isotherm for all tumor sizes and electrode types, but enabled ablation of a given tumor size at higher tissue perfusions. An inner thermal conductivity equivalent to soft tissue (0.5 W/m- degrees C) surrounded by fat (0.23 W/m- degrees C) permitted the greatest degree of tumor heating in the shortest time, while soft tissue surrounded by ascites (0.7 W/m- degrees C) took longer to achieve the 50 degrees C isotherm, and complete ablation

  4. Effect of hydrophobic coating on the magnetic anisotropy and radiofrequency heating of γ-Fe2O3 nanoparticles

    International Nuclear Information System (INIS)

    Singh, Mandeep; Ulbrich, Pavel; Prokopec, Vadym; Svoboda, Pavel; Šantavá, Eva; Štěpánek, František

    2013-01-01

    The effect of a hydrophobic (oleic acid) coating on the magnetic properties of maghemite (γ-Fe 2 O 3 ) nanoparticles was investigated. The nanoparticles were prepared by a novel bi-phasic co-precipitation route and their properties compared with uncoated nanoparticles and nanoparticles prepared by a standard single-phase process. The oleic acid coated nanoparticles had a mean diameter of 6 nm when the two-phase precipitation procedure was used compared to 12 nm for nanoparticles prepared in a single phase under otherwise identical conditions. Super Quantum Interference Device measurements show superparamagnetism of the nanoparticles, with a saturation magnetization at 4 K to be 66.4 emu/g and 89.0 emu/g for the coated nanoparticles obtained by two- and single-phase procedure, respectively. Zero-field-cooled and field-cooled curves reveal a dramatic shift in the blocking temperature of the coated nanoparticles, and a significant change in their anisotropy. The hydrophobic nanoparticles were able to form stable ferrofluids in a range of organic solvents and show good heating rates in a 400 kHz alternating magnetic field. - Highlights: ► Hydrophobic iron oxide nanoparticles synthesized by a new microemulsion approach. ► Strong influence of oleic acid coating on blocking temperature observed. ► Stable non-aqueous ferrofluids prepared. ► Favorable heating rates under alternating magnetic field

  5. Investigation of auxiliary heating in tandem mirrors and tokamaks and barrier cell pumping. Annual progress report, October 1, 1980 to December 31, 1981

    International Nuclear Information System (INIS)

    Emmert, G.A.; Scharer, J.

    1981-06-01

    The research has focussed on physics questions concerned with ECRH heating in tandem mirror plugs, pumping of tandem mirror thermal barriers by drift orbits, ICRH heating in tokamaks, and bundle divertors. We have concluded that drift-orbit pumping of thermal barriers is not feasible because the azimuthal E Vector X B Vector drift limits the excursion of trapped ions from a flux surface. We have developed a three-dimensional weakly relativistic (T/sub e/ less than or equal to 50 keV) ray tracing and absorption code for electron cyclotron heating in tandem mirror plugs and barriers. Cases run for TMX, MFTF-B and reactors at T/sub e/ > 10 keV show that strong absorption per pass is present and a careful choice of wave frequency and launch angle is required to ensure wave penetration and absorption in the plasma core. In the area of ion cyclotron frequency range heating in tokamaks, a three-dimensional hot plasma ray tracing theory and code has been developed to handle rays launched from any poloidal angle in the tokamak cross section. Wave heating in the central strong absorption zones is currently being investigated using a full wave solution for the various heating regimes

  6. Auxiliary office chair

    OpenAIRE

    Pascual Osés, Maite

    2007-01-01

    The aim of this project is to develop an auxiliary office chair, which favorably will compete with the existing chairs on the market. Evolutions of ergonomical survey in the work environment and on the configuration of offices require new products which fulfill the requirements properly. In order to achieve it a survey about office chairs has been carried out: types, characteristics, ways of usage and products on the market besides a large antropometrical study and ergonomics related to work ...

  7. Theoretical studies of the heating of toroidal plasmas with radiofrequency electromagnetic radiation. Progress report, July 1, 1985-June 30, 1986

    International Nuclear Information System (INIS)

    Swanson, D.G.; Wersinger, J.M.; Hanson, J.D.

    1986-04-01

    Progress is reported in several areas of interest to rf heating of plasmas. (1) The continuing improvement of the ray-tracing code includes improved speed and accuracy. The development of a complex ray-tracing code is largely implemented. This allows the following of rays through regions where normal ray-tracing methods fail. (2) A major contribution is in the area of parametric instabilities, and a way to minimize their effect on the lower hybrid waves. By following a bundle of rays and evaluating the growth rate for the most rapidly growing waves at each point, the daughter waves have been followed to the point where pump depletion begins to be important. (3) The continuing study of mode conversion problems has taken several directions. It has been shown that ion absorption of lower hybrid rays frequently involves cases where three types of waves are coupled through linear mode conversion in the same region of space, namely the cold lower hybrid wave, the warm lower hybrid wave, and an ion Bernstein mode. This three wave coupling problem is analyzed analytically in terms of a sixth order wave equation which describes coupling between all branches, but the analytical model may not adequately represent the physical problem. Numerical methods have been compared in terms of accuracy, and the comparisons show some touted methods to be useful only in very restricted ranges of parameter space. Finally, a method of reducing the order of the differential equations in mode conversion problems is described which is exact

  8. Does Artificial Ascites Induce the Heat-Sink Phenomenon during Percutaneous Radiofrequency Ablation of the Hepatic Subcapsular Area?: an in vivo Experimental Study Using a Rabbit Model

    International Nuclear Information System (INIS)

    Kim, Young Sun; Rhim, Hyun Chul; Choi, Dong Il; Lim, Hyo K.

    2009-01-01

    To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model. A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05). One rabbit from the 'W' group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups 'W' and 'R' throughout the procedures (39.2± 0.4 .deg. C in group W and 33.4±4.3 .deg. C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4±237.3 mL in group C, 1,172.0±468.9 mL in group R, and 1,030.6±665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group 'C' rabbits (p = 0.030). Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region

  9. Does artificial ascites induce the heat-sink phenomenon during percutaneous radiofrequency ablation of the hepatic subcapsular area?: an in vivo experimental study using a rabbit model.

    Science.gov (United States)

    Kim, Young Sun; Rhim, Hyunchul; Choi, Dongil; Lim, Hyo K

    2009-01-01

    To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model. A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05). One rabbit from the "W" group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups "W" and "R" throughout the procedures (39.2+/-0.4 degrees C in group W and 33.4+/-4.3 degrees C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4+/-237.3 mL in group C, 1,172.0+/-468.9 mL in group R, and 1,030.6+/-665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group "C" rabbits (p = 0.030). Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region.

  10. WORKSHOPS: Radiofrequency superconductivity

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991

  11. WORKSHOPS: Radiofrequency superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-01-15

    In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991.

  12. Annual progress report on an investigation of auxiliary heating in tandem mirrors and tokamaks for the period January 1, 1982-December 31, 1982

    International Nuclear Information System (INIS)

    Scharer, J.E.

    1982-07-01

    The research has focused on physics questions concerned with ECRF heating in tandem mirror plugs and barriers and ICRF coupling and heating in tokamaks. We have utilized a three-dimensional weakly relativistic (T/sub e/ less than or equal to 50 keV) ray tracing and absorption code we have developed for electron cyclotron heating in tandem mirror plugs and barriers. Cases run for TMX, MFTF-B and reactors at T/sub e/ > 10 keV show that strong absorption per pass is present and a careful choice of wave mode, frequency and launch angle is required to ensure wave penetration and absorption in the plasma core. At elevated electron temperatures (T/sub e/ > 10 keV), ordinary mode launch at theta approx. = 70 0 provides good single pass absorption without the edge absorption problems associated with the extraordinary mode. We have also developed an ICRF 1-D slab model to investigate coupling and heating in tokamak plasmas

  13. Theoretical studies of the heating of toroidal plasmas with radiofrequency electromagnetic radiation: Progress report, July 1, 1986-June 30, 1987

    International Nuclear Information System (INIS)

    Swanson, D.G.; Wersinger, J.M.; Hanson, J.D.

    1987-02-01

    Progress is reported in several areas of interest to rf heating of plasmas. (1) The development of the complex ray-tracing code is largely implemented. The complex focussing terms are nearing completion. This allows the following of rays through regions where normal ray-tracing methods fail. (2) A major contribution is in the area of parametric instabilities, and a way to minimize their effect on the lower hybrid waves. By following a bundle of rays and evaluating the growth rate for the most rapidly growing waves at each point, the daughter waves have been followed to the point where pump depletion begins to be important. It is found that pump depletion is a serious problem for lower hybrid rays in typical plasmas, but its effect can be diminished in some cases by frequency modulation. (3) The continuing study of mode conversion problems has taken several directions. It has been shown that ion absorption of lower hybrid rays frequently involves cases where three types of waves are coupled through linear mode conversion in the same region of space, namely the cold lower hybrid wave, the warm lower hybrid wave, and an ion Bernstein mode. This three wave coupling problem is analyzed analytically in terms of a sixth order wave equation which describes coupling between all branches, and an analytical model may now adequately represent the physical problem. The formal solution of this equation verifies the major expectations of the analysis, and gives analytic coupling coefficients for the case with no damping. Finally, the exact order reduction method has been developed to the extent where numerical methods need to be introduced. The analytic evaluation of the form of the Green function is completed, and numerical implementation will begin before the end of the current contracting period and continue through the extended renewal period

  14. Comparative investigation of conventional and R744 auxiliary heating systems in motor cars with low fuel consumption on the basis of a 1.9 l TDI engine; Vergleich konventioneller Zuheizsysteme mit R744-Zuheizsystemen in Automobilen mit geringem Kraftstoffverbrauch auf Basis eines 1,9 l TDI Motors

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, B.; Feuerecker, G.; Heinle, D.; Strauss, T. [Behr GmbH und Co. KG, Stuttgart (Germany). Entwicklungszentrum

    2003-07-01

    The heat emitted by modern consumption-optimized engines, especially diesel engines, is so low that auxiliary heating systems are required for thermal comfort. With R744 air conditioning systems, the air conditioner can be used as auxiliary heating system. The contribution therefore compares conventional PTC and fuel based auxiliary heating systems with three R744 auxiliary heating systems (air-to-air heat pump, coolant-to-air heat pump, and delta process). Simulations were carried out in order to compare heat-up, fuel consumption, and cost. The simulation models were used for calculating demand-oriented heating at different ambient temperatures with a 1.9 l TDI engine. The BEHR software BISS (Behr Integrierte System Simulation) was used as simulation tool. The performance of the heat pump was significantly lower than the performance of conventional auxiliary heating systems at all temperatures. On the other hand, the additional fuel consumption as referred to performance was 15 percent lower than for conventional heating systems. The PTC system had the best cost/profit ratio. (orig.) [German] Der Anteil verbrauchsoptimierter Verbrennungsmotoren, insbesondere Diesel, ist in Europa in den letzten Jahren rasant gestiegen. Die Waermeabgabe dieser Motoren ist inzwischen so niedrig, dass fuer eine rasche und komfortable Aufheizung der Fahrzeugkabine Zuheizsysteme eingesetzt werden muessen. Beim Einsatz von Kohlendioxid (R744) als Kaeltemittel einer Klimaanlage, ist auch ein Betrieb der Klimaanlage als Zuheizsystem denkbar. In diesem Beitrag werden die konventionellen Zuheizsysteme PTC-Zuheizer und Brennstoffzuheizer mit drei R744-Zuheizsystemen mittels Simulation bezueglich Aufheizverhalten, Kraftstoffverbrauch und Kosten bewertet. Die R744 Zuheizsysteme sind Luft-Luft Waermepumpe, Kuehlmittel-Luft-Waermepumpe und Dreiecksprozess. Mit den Simulationsmodellen wurden Berechnungen einer bedarfsorientierten Aufheizung fuer verschiedene Umgebungstemperaturen auf Basis eines

  15. radiofrequency cavity

    CERN Multimedia

    1988-01-01

    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.

  16. Radiofrequency Ablation of Lung Tumors

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Radiofrequency Ablation (RFA) / Microwave Ablation (MWA) of Lung Tumors ... and Microwave Ablation of Lung Tumors? What are Radiofrequency and Microwave Ablation of Lung Tumors? Radiofrequency ablation, ...

  17. Heat transfer equipment performance diagnosis of auxiliary systems in electric power stations; Diagnostico de comportamiento de equipo de transferencia de calor de sistemas auxiliares de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Esparza Gutierrez, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in order to control the performance, compare them among similar units and power stations, and inclusively verify possible recurrent causes of low availability in the referred systems. [Espanol] En este articulo se presenta la metodologia seguida para diagnosticar el comportamiento de equipos en los que se transfiere calor de los sistemas de agua de alimentacion, condensado y circulacion de las centrales termoelectricas (CTE). La toma de datos se realiza con la unidad en operacion normal, utilizando instrumentacion local sin necesidad de sacar de servicio a los equipos para su instalacion, ya que se ocupan los mismos puntos para instrumentos con que cuentan por diseno. El diagnostico de los equipos se realiza mediante el analisis de los datos recopilados, tanto de operacion real como de diseno; para ello, se efectua un balance termico de los sistemas de interes para obtener todas las condiciones y los datos de operacion. Posteriormente, se calculan los parametros indicativos de

  18. Heat transfer equipment performance diagnosis of auxiliary systems in electric power stations; Diagnostico de comportamiento de equipo de transferencia de calor de sistemas auxiliares de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Esparza Gutierrez, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in order to control the performance, compare them among similar units and power stations, and inclusively verify possible recurrent causes of low availability in the referred systems. [Espanol] En este articulo se presenta la metodologia seguida para diagnosticar el comportamiento de equipos en los que se transfiere calor de los sistemas de agua de alimentacion, condensado y circulacion de las centrales termoelectricas (CTE). La toma de datos se realiza con la unidad en operacion normal, utilizando instrumentacion local sin necesidad de sacar de servicio a los equipos para su instalacion, ya que se ocupan los mismos puntos para instrumentos con que cuentan por diseno. El diagnostico de los equipos se realiza mediante el analisis de los datos recopilados, tanto de operacion real como de diseno; para ello, se efectua un balance termico de los sistemas de interes para obtener todas las condiciones y los datos de operacion. Posteriormente, se calculan los parametros indicativos de

  19. Influence of moisture content on inactivation of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in powdered red and black pepper spices by radio-frequency heating.

    Science.gov (United States)

    Jeong, Seul-Gi; Kang, Dong-Hyun

    2014-04-17

    The influence of moisture content during radio-frequency (RF) heating on heating rate, dielectric properties, and inactivation of foodborne pathogens was investigated. The effect of RF heating on the quality of powdered red and black pepper spices with different moisture ranges was also investigated. Red pepper (12.6%, 15.2%, 19.1%, and 23.3% dry basis, db) and black pepper (10.1%, 17.2%, 23.7%, and 30.5% db) inoculated with Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium were treated in a RF heating system with 27.12 MHz. The heating rate of the sample was dependent on moisture content up to 19.1% (db) of red pepper and 17.2% (db) of black pepper, but there was a significant decrease in the heating rate when the moisture content was increased beyond these levels. The dielectric properties of both samples increased with a rise in moisture content. As the moisture content increased, treatment time required to reduce E. coli O157:H7 and S. Typhimurium by more than 7 log CFU/g (below the detection limit, 1 log CFU/g) decreased and then increased again without affecting product quality when the moisture content exceeded a level corresponding to the peak heating rate. RF treatment significantly (Pspices. These results suggest that RF heating can be effectively used to not only control pathogens but also reduce moisture levels in spices and that the effect of inactivation is dependent on moisture content. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. The efficiency analysis on solar energy auxiliary soil source heat pump heating in cold region%严寒地区太阳能辅助土壤源热泵供热经济性分析

    Institute of Scientific and Technical Information of China (English)

    王杨洋

    2016-01-01

    To solve the suction and discharge heat imbalance problems in soil source heat pump system long running in cold region,this paper put forward the solar assisted soil source heat pump system,and compared the efficiency of this plan with traditional central heating system,pointed out that the solar assisted soil source heat pump system in service life cycle had good energy conservation and environmental protection benefits.%为解决严寒地区土壤源热泵系统长期运行出现吸排热量失衡的问题,提出了太阳能辅助土壤源热泵系统方案,并将该方案与传统集中供热系统方案的经济性作了对比,指出太阳能辅助土壤源热泵系统在使用寿命周期内具有良好的节能环保效益。

  1. Radiofrequency-thermoablation in malignant liver disease

    International Nuclear Information System (INIS)

    Pichler, L.; Anzboeck, W.; Paertan, G.; Hruby, W.

    2002-01-01

    The clinical application of radiofrequency tumor ablation in primary liver tumors and metastatic liver disease is rapidly growing because this technique has proven to be simple, safe, and effective in first clinical studies. Most of the patients with malignant liver disease are not candidates for surgical resection due localisation or comorbidity, so radiofrequency therapy offers a good alternative for inoperable patients. With this method, high frequency alternating current is delivered to tissue via a needle electrode, the produced heat leads to coagulation necrosis. The largest focus of necrosis that can be induced with the currently available systems is approximately 4-5 cm with a single application. The radiofrequency needle is usually placed with US or CT guidance. For follow up examinations CT and MRI can be used, they proved to be equally accurate in the assessment of treatment response. (orig.) [de

  2. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  3. Ablation of liver metastases by radiofrequency

    International Nuclear Information System (INIS)

    Baere, T. de

    2012-01-01

    Radiofrequency is a thermal ablative technique that is most often used percuteanously under image guidance. Thermal damage is obtained through frictional heating of a high frequency current. The maximal volume of destruction obtained in one radiofrequency delivery is around 4 cm and consequently, best indication for treatment are tumours below 3 cm. When compared, radiofrequency and surgical removal for tumours below 25 mm in diameter demonstrated a rate of incomplete resection/ablation of 6% and 7.3% respectively. Median survival after the first radiofrequency of a liver metastasis of CRC is reported to be 24 to 52 months with a 5 years overall survival of 18 to 44%. The median overall survival increases from 22 to 48 months depending on the use of radiofrequency ablation as rescue treatment after failure of others, or as a first line treatment. For patients with a single tumour, less than 4 cm, the survival rates at 1, 3, and 5 years are respectively 97%, 84% and 40%, with a median survival of 50 months. Follow-up imaging requires to use contrast-enhanced CT or MRI, looking for local recurrences evidenced by local foci of enhancement at the periphery of the ablation zone. (author)

  4. Calculation of heat fluxes induced by radio frequency heating on the actively cooled protections of ion cyclotron resonant heating (ICRH) and lower hybrid (LH) antennas in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Ritz, G., E-mail: Guillaume.ritz@gmail.com [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France); Corre, Y., E-mail: Yann.corre@cea.fr [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France); Rault, M.; Missirlian, M. [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France); Portafaix, C. [ITER Organization, Route de Vinon-sur-Verdon, 13115 Saint Paul-lez-Durance (France); Martinez, A.; Ekedahl, A.; Colas, L.; Guilhem, D.; Salami, M.; Loarer, T. [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France)

    2013-10-15

    Highlights: ► The heat flux generated by radiofrequency (RF) heating was calculated using Tore Supra's heating antennas. ► The highest heat flux value, generated by ions accelerated in RF-rectified sheath potentials, was 5 MW/m{sup 2}. ► The heat flux on the limiters of antennas was in the same order of magnitude as that on the toroidal pumping limiter. -- Abstract: Lower hybrid current drive (LHCD) and ion cyclotron resonance heating (ICRH) are recognized as important auxiliary heating and current drive methods for present and next step fusion devices. However, these radio frequency (RF) systems generate a heat flux up to several MW/m{sup 2} on the RF antennas during plasma operation. This paper focuses on the determination of the heat flux deposited on the lateral protections of the RF antennas in Tore Supra. The heat flux was calculated by finite element method (FEM) using a model of the lateral protection. The FEM calculation was based on surface temperature measurements using infrared cameras monitoring the RF antennas. The heat flux related to the acceleration of electrons in front of the LHCD grills (LHCD active) and to the acceleration of ions in RF-rectified sheath potentials (ICRH active) were calculated. Complementary results on the heat flux related to fast ions (ICRH active with a relatively low magnetic field) are also reported in this paper.

  5. Radiofrequency ablation in dermatology

    Directory of Open Access Journals (Sweden)

    Sachdeva Silonie

    2007-01-01

    Full Text Available Radiofreqeuency ablation is a versatile dermatosurgical procedure used for surgical management of skin lesions by using various forms of alternating current at an ultra high frequency. The major modalities in radiofrequency are electrosection, electrocoagulation, electrodessication and fulguration. The use of radiofrequency ablation in dermatosurgical practice has gained importance in recent years as it can be used to treat most of the skin lesions with ease in less time with clean surgical field due to adequate hemostasis and with minimal side effects and complications. This article focuses on the major tissue effects and factors influencing radiofrequency ablation and its application for various dermatological conditions.

  6. Auxiliary services for petrochemistry. Cogeneration, thermocompression, steam distribution networks

    International Nuclear Information System (INIS)

    Vergerio, G.; Bruzzi, V.

    1999-01-01

    The article gives some guidelines for the choice of the most suitable energy vectors distributed in petrochemical plants and refineries for auxiliary services and for processes (mainly distillation). Conclusions are summed up in a diagram showing the most suitable heat sources and sinks for the various temperature ranges [it

  7. PWR auxiliary systems, safety and emergency systems, accident analysis, operation

    International Nuclear Information System (INIS)

    Meyer, P.J.

    1976-01-01

    The author presents a description of PWR auxiliary systems like volume control, boric acid control, coolant purification, -degassing, -storage and -treatment system and waste processing systems. Residual heat removal systems, emergency systems and containment designs are discussed. As an accident analysis the author gives a survey over malfunctions and disturbances in the field of reactor operations. (TK) [de

  8. Cooling system for auxiliary systems of a nuclear power plant

    International Nuclear Information System (INIS)

    Maerker, W.; Mueller, K.; Roller, W.

    1981-01-01

    From the reactor auxiliary and ancillary systems of a nuclear facility heat has to be removed without the hazard arising that radioactive liquids or gases may escape from the safe area of the nuclear facility. A cooling system is described allowing at every moment to make available cooling fluid at a temperature sufficiently low for heat exchangers to be able to remove the heat from such auxiliary systems without needing fresh water supply or water reservoirs. For this purpose a dry cooling tower is connected in series with a heat exchanger that is cooled on the secondary side by means of a refrigerating machine. The cooling pipes are filled with a nonfreezable fluid. By means of a bypass a minimum temperature is guaranteed at cold weather. (orig.) [de

  9. RADIOFREQUENCY SUPERCONDUCTIVITY: Workshop

    International Nuclear Information System (INIS)

    Lengeler, Herbert

    1989-01-01

    Superconducting radiofrequency is already playing an important role in the beam acceleration system for the TRISTAN electron-positron collider at the Japanese KEK Laboratory and new such systems are being prepared for other major machines. Thus the fourth Workshop on Radiofrequency Superconductivity, organized by KEK under the chairmanship of local specialist Yuzo Kojima and held just before the International Conference on High Energy Accelerators, had much progress to review and even more to look forward to

  10. Improving Energy Efficiency of Auxiliaries

    International Nuclear Information System (INIS)

    Carl T. Vuk

    2001-01-01

    The summaries of this report are: Economics Ultimately Dictates Direction; Electric Auxiliaries Provide Solid Benefits. The Impact on Vehicle Architecture Will be Important; Integrated Generators With Combined With Turbo Generators Can Meet the Electrical Demands of Electric Auxiliaries; Implementation Will Follow Automotive 42V Transition; Availability of Low Cost Hardware Will Slow Implementation; Industry Leadership and Cooperation Needed; Standards and Safety Protocols Will be Important. Government Can Play an Important Role in Expediting: Funding Technical Development; Incentives for Improving Fuel Economy; Developing Standards, Allowing Economy of Scale; and Providing Safety Guidelines

  11. Waste heat recovering device for reactors

    International Nuclear Information System (INIS)

    Sonoda, Masanobu; Shiraishi, Tadashi; Mizuno, Hiroyuki; Sekine, Yasuhiro.

    1982-01-01

    Purpose: To enable utilization of auxiliary-equipment-cooling water from a non-regenerative heat exchanger as a heat source, as well as prevent radioactive contamination. Constitution: A water warming device for recovering the heat of auxiliary equipment cooling water from a non-regenerative heat exchanger is disposed at the succeeding stage of the heat exchanger. Heat exchange is performed in the water warming device between the auxiliary equipment cooling water and a heat source water set to a higher pressure and recycled through the water warming device. The heat recovered from the auxiliary equipment cooling water is utilized in the heat source water for operating relevant equipments. (Aizawa, K.)

  12. Hydraulic turbines and auxiliary equipment

    Energy Technology Data Exchange (ETDEWEB)

    Luo Gaorong [Organization of the United Nations, Beijing (China). International Centre of Small Hydroelectric Power Plants

    1995-07-01

    This document presents a general overview on hydraulic turbines and auxiliary equipment, emphasizing the turbine classification, in accordance with the different types of turbines, standard turbine series in China, turbine selection based on the basic data required for the preliminary design, general hill model curves, chart of turbine series and the arrangement of application for hydraulic turbines, hydraulic turbine testing, and speed regulating device.

  13. Aspectual auxiliary verbs in Xitsonga

    African Journals Online (AJOL)

    Kate H

    Let him always come' e. á vá hátl-é vá yá étlélà. OPT 3PL quickly-OPT 3PL go sleep. 'Let them quickly go to bed'. 3.4 Negative markers. Negation is marked on AA verbs. The auxiliary verb hatla 'quickly' is negated in three tenses.

  14. 33 CFR 5.47 - Auxiliary ensign.

    Science.gov (United States)

    2010-07-01

    ... matching blue Coast Guard Auxiliary emblem is centered. The white slash shall be at a 70 degree angle, rising away from the hoist. (c) The Auxiliary emblem consists of a disk with the shield of the Coat of...

  15. Radiofrequency ablation of osteoid osteoma

    NARCIS (Netherlands)

    Vanderschueren, Geert Maria Joris Michael

    2009-01-01

    The main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the technical requirements needed for safe radiofrequency ablation and the clinical outcome after radiofrequency

  16. 45 CFR 707.10 - Auxiliary aids.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Auxiliary aids. 707.10 Section 707.10 Public Welfare Regulations Relating to Public Welfare (Continued) COMMISSION ON CIVIL RIGHTS ENFORCEMENT OF... § 707.10 Auxiliary aids. (a) The Agency shall furnish appropriate auxiliary aids where necessary to...

  17. 7 CFR 15b.37 - Auxiliary aids.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Auxiliary aids. 15b.37 Section 15b.37 Agriculture... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Other Aid, Benefits, or Services § 15b.37 Auxiliary aids... appropriate auxiliary aids to persons with impaired sensory, manual, or speaking skills, where necessary to...

  18. 30 CFR 57.6161 - Auxiliary facilities.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary facilities. 57.6161 Section 57.6161...-Underground Only § 57.6161 Auxiliary facilities. (a) Auxiliary facilities used to store explosive material near work places shall be wooden, box-type containers equipped with covers or doors, or facilities...

  19. Auxiliary resonant DC tank converter

    Science.gov (United States)

    Peng, Fang Z.

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  20. Proceedings: Power Plant Electric Auxiliary Systems Workshop

    International Nuclear Information System (INIS)

    1992-06-01

    The EPRI Power Plant Electric Auxiliary Systems Workshop, held April 24--25, 1991, in Princeton, New Jersey, brought together utilities, architect/engineers, and equipment suppliers to discuss common problems with power plant auxiliary systems. Workshop participants presented papers on monitoring, identifying, and solving problems with auxiliary systems. Panel discussions focused on improving systems and existing and future plants. The solutions presented to common auxiliary system problems focused on practical ideas that can enhance plant availability, reduce maintenance costs, and simplify the engineering process. The 13 papers in these proceedings include: Tutorials on auxiliary electrical systems and motors; descriptions of evaluations, software development, and new technologies used recently by electric utilities; an analysis of historical performance losses caused by power plant auxiliary systems; innovative design concepts for improving auxiliary system performance in future power plants

  1. Interactions between radiofrequency signals and living organisms

    International Nuclear Information System (INIS)

    Boudin, F.; Hours, M.; Lacronique, J.F.; Conil, E.; Hadjem, A.; El Habachi, A.; Wiart, K.; Mann, S.; Kundi, M.; Marc-Vergnes, J.P.; Roosli, M.; Mohler, E.; Frei, P.; Davis, Ch.C.; Balzano, Q.; Ait-Aissa, S.; Billaudel, B.; Poulletier De Gannes, F.; Hurtier, A.; Haro, E.; Taxile, M.; Veyret, B.; Lagroye, I.; Ait-Aissa, S.; Poulletier De Gannes, F.; Athane, A.; Veyret, B.; Lagroye, I.; Yardin, C.; Perrin, A.; Freire, M.; Bachelet, Ch.; Collin, A.; Pla, S.; Debouzy, J.C.; Leveque, Ph.; Van Nierop, L.E.; Huss, A.; Roosli, M.; Egger, M.; Calvez, M.; Salomon, D.

    2010-01-01

    This dossier is composed of 13 articles dealing with the interactions between radio-frequencies and living organisms. It is an overview of various scientific approaches to the field and is of interest for all citizens as the use of mobile phones is widely spread. In the first article it is shown how a model has been built to assess the distribution of the whole body exposure of the population. The second article reviews the state of the art in personal exposure measurements at radio-frequencies. The third article shows that the knowledge of the mechanism of action by which exposure increases the risk of health hazards is necessary. The fourth article shows that individual neuro-psychic factors take a prominent but maybe not unique, part in electromagnetic hypersensitivity. The fifth article shows that no evidence was found to link health disturbances of electromagnetic hypersensitive individuals with radiofrequency exposure. The sixth article shows that the wireless phone is not an athermal hazard to the brain. The seventh article shows that the in utero and post-natal exposure to Wi-Fi does not damage the brains of young rats. The eighth article concludes that recent studies provide no convincing proof of deleterious effects of radiofrequency exposure on the integrity of the blood-brain barrier for specific absorption rates up to 6 W/kg. The ninth article shows that no co-genotoxic effect of radiofrequency was found at levels of exposure that did not induce heating. The tenth article confirms that industry-sponsored studies were least likely to report results suggesting effects. The last article shows that general practitioners are increasingly questioned by their patients about the issue of electromagnetic waves. (A.C.)

  2. Auxiliary feedwater system aging study

    International Nuclear Information System (INIS)

    Kueck, J.D.

    1992-01-01

    The Phase 1 Auxiliary Feedwater (AFW) System Aging Study, NUREG/CR-5404 V1, focused on how and to what extent the various AFW system component types fail, how the failures have been and can be detected, and on the value of current testing requirements and practices. This follow-on study, which will be provided in full in NUREG/CR-5404 V2, provides a closure to the Phase 1 Study. For each of the component types and for the various sources of component failure identified in the Phase 1 Study, the methods of failure detection were designated and tabulated and the following findings became evident: Instrumentation and Control (I and C) related failures dominated the group of failures that were detected during demand conditions; many of the potential failure sources not detectable by the current monitoring practices were related to the I and C portion of the system; some component failure modes are actually aggravated by conventional test methods; and several important system functions did not undergo any function verification test. The goal of this follow-on study was to categorize and evaluate the deficiencies in testing identified by Phase 1 and to make specific recommendations for corrective action. In addition, this study presents discussions of alternate, state-of-the-art test methods, and provides a proposed Auxiliary Feedwater Pump test at normal operating pressure which should do much to verify system operability while eliminating degradation

  3. Fast beam radiofrequency spectroscopy

    International Nuclear Information System (INIS)

    Pipkin, F.M.

    1983-01-01

    The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

  4. WORKSHOP: Radiofrequency superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-10-15

    The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators.

  5. WORKSHOP: Radiofrequency superconductivity

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators

  6. Solar combisystems with forecast control to increase the solar fraction and lower the auxiliary energy cost

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Fan, Jianhua

    2011-01-01

    Solar Combi systems still need quite a lot of auxiliary energy especially in small systems without seasonal storage possibilities. The control of the auxiliary energy input both in time and power is important to utilize as much as possible of the solar energy available from the collectors and also...... energy sources. It can be either direct electric heating elements or a heat pump upgrading ambient energy in the air, ground, solar collector or waste heat from the house. The paper describes system modeling and simulation results. Advanced laboratory experiments are also starting now with three...

  7. Visualizing radiofrequency-skin interaction using multiphoton microscopy in vivo.

    Science.gov (United States)

    Tsai, Tsung-Hua; Lin, Sung-Jan; Lee, Woan-Ruoh; Wang, Chun-Chin; Hsu, Chih-Ting; Chu, Thomas; Dong, Chen-Yuan

    2012-02-01

    Redundant skin laxity is a major feature of aging. Recently, radiofrequency has been introduced for nonablative tissue tightening by volumetric heating of the deep dermis. Despite the wide range of application based on this therapy, the effect of this technique on tissue and the subsequent tissue remodeling have not been investigated in detail. Our objective is to evaluate the potential of non-linear optics, including multiphoton autofluorescence and second harmonic generation (SHG) microscopy, as a non-invasive imaging modality for the real-time study of radiofrequency-tissue interaction. Electro-optical synergy device (ELOS) was used as the radiofrequency source in this study. The back skin of nude mouse was irradiated with radiofrequency at different passes. We evaluated the effect on skin immediately and 1 month after treatment with multiphoton microscopy. Corresponding histology was performed for comparison. We found that SHG is negatively correlated to radiofrequency passes, which means that collagen structural disruption happens immediately after thermal damage. After 1 month of collagen remodeling, SHG signals increased above baseline, indicating that collagen regeneration has occurred. Our findings may explain mechanism of nonablative skin tightening and were supported by histological examinations. Our work showed that monitoring the dermal heating status of RF and following up the detailed process of tissue reaction can be imaged and quantified with multiphoton microscopy non-invasively in vivo. Copyright © 2011. Published by Elsevier Ireland Ltd.

  8. The Acquisition of Auxiliary Syntax: A Longitudinal Elicitation Study. Part 1: Auxiliary BE

    Science.gov (United States)

    Theakston, Anna L.; Rowland, Caroline F.

    2009-01-01

    Purpose: The question of how and when English-speaking children acquire auxiliaries is the subject of extensive debate. Some researchers posit the existence of innately given Universal Grammar principles to guide acquisition, although some aspects of the auxiliary system must be learned from the input. Others suggest that auxiliaries can be…

  9. Auxiliary feedwater system aging study

    International Nuclear Information System (INIS)

    Kueck, J.D.

    1993-07-01

    This report documents the results of a Phase I follow-on study of the Auxiliary Feedwater (AFW) System that has been conducted for the US Regulatory Commission's Nuclear Plant Aging research Program. The Phase I study found a number of significant AFW System functions that are not being adequately tested by conventional test methods and some that are actually being degraded by conventional testing. Thus, it was decided that this follow-on study would focus on these testing omissions nd equipment degradation. The deficiencies in current monitoring and operating practice are categorized and evaluated. Areas of component degradation caused by current practice are discussed. Recommendations are made for improved diagnostic methods and test procedures

  10. Radio-frequency energy in fusion power generation

    International Nuclear Information System (INIS)

    Lawson, J.Q.; Becraft, W.R.; Hoffman, D.J.

    1983-01-01

    The history of radio-frequency (rf) energy in fusion experiments is reviewed, and the status of current efforts is described. Potential applications to tasks other than plasma heating are described, as are the research and development needs of rf energy technology

  11. 47 CFR 73.1675 - Auxiliary antennas.

    Science.gov (United States)

    2010-10-01

    ... Class A TV licensees may request a decrease from the authorized facility's ERP in the license application. An FM, TV or Class A TV licensee may also increase the ERP of the auxiliary facility in a license... licensed main facility as an auxiliary facility with an ERP less than or equal to the ERP specified on the...

  12. 78 FR 27321 - Revision of Auxiliary Regulations

    Science.gov (United States)

    2013-05-10

    ... Auxiliary organizational structure, extending civil liability protection to Auxiliary units and members, and... entities. C. Assistance for Small Entities If you think that your business, organization, or governmental..., explain why you think your business or organization qualifies, how and to what degree this rule would...

  13. Radiofrequency in cosmetic dermatology.

    Science.gov (United States)

    Beasley, Karen L; Weiss, Robert A

    2014-01-01

    The demand for noninvasive methods of facial and body rejuvenation has experienced exponential growth over the last decade. There is a particular interest in safe and effective ways to decrease skin laxity and smooth irregular body contours and texture without downtime. These noninvasive treatments are being sought after because less time for recovery means less time lost from work and social endeavors. Radiofrequency (RF) treatments are traditionally titrated to be nonablative and are optimal for those wishing to avoid recovery time. Not only is there minimal recovery but also a high level of safety with aesthetic RF treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. International radiofrequency standards

    International Nuclear Information System (INIS)

    Lincoln, J.

    2001-01-01

    Of the various radiofrequency standards in use around the world, many are based on or similar to the Guidelines published by ICNIRP (The International Commission on Non-ionising Radiation Protection). This organisation is a working group operating in co-operation with the Environmental Health division of the World Health Organisation (WHO). This paper presents a very brief overview of current international standards, beginning with a summary of the salient points of the ICNIRP Guidelines. It should be remembered that these are guidelines only and do not exist as a separate standard. Copyright (2001) Australasian Radiation Protection Society Inc

  15. Hybrid mesons with auxiliary fields

    International Nuclear Information System (INIS)

    Buisseret, F.; Mathieu, V.

    2006-01-01

    Hybrid mesons are exotic mesons in which the color field is not in the ground state. Their understanding deserves interest from a theoretical point of view, because it is intimately related to nonperturbative aspects of QCD. Moreover, it seems that some recently detected particles, such as the π 1 (1600) and the Y(4260), are serious hybrid candidates. In this work, we investigate the description of such exotic hadrons by applying the auxiliary fields technique (also known as the einbein field method) to the widely used spinless Salpeter Hamiltonian with appropriate linear confinement. Instead of the usual numerical resolution, this technique allows to find simplified analytical mass spectra and wave functions of the Hamiltonian, which still lead to reliable qualitative predictions. We analyse and compare two different descriptions of hybrid mesons, namely a two-body q system with an excited flux tube, or a three-body qg system. We also compute the masses of the 1 -+ hybrids. Our results are shown to be in satisfactory agreement with lattice QCD and other effective models. (orig.)

  16. Radiofrequency ablation of liver tumors (II): clinical application and outcomes.

    Science.gov (United States)

    Vanagas, Tomas; Gulbinas, Antanas; Pundzius, Juozas; Barauskas, Giedrius

    2010-01-01

    Radiofrequency ablation is one of the alternatives in the management of liver tumors, especially in patients who are not candidates for surgery. The aim of this article is to review applicability of radiofrequency ablation achieving complete tumor destruction, utility of imaging techniques for patients' follow-up, indications for local ablative procedures, procedure-associated morbidity and mortality, and long-term results in patients with different tumors. The success of local thermal ablation consists in creating adequate volumes of tissue destruction with adequate "clear margin," depending on improved delivery of radiofrequency energy and modulated tissue biophysiology. Different volumes of coagulation necrosis are achieved applying different types of electrodes, pulsing energy sources, utilizing sophisticated ablation schemes. Some additional methods are used to increase the overall deposition of energy through alterations in tissue electrical conductivity, to improve heat retention within the tissue, and to modulate tolerance of tumor tissue to hyperthermia. Contrast-enhanced computed tomography, magnetic resonance imaging, ultrasound or positron emission tomography are applied to control the effectiveness of radiofrequency ablation. The long-term results of radiofrequency ablation are controversial.

  17. Heating in toroidal plasmas

    International Nuclear Information System (INIS)

    Knoepfel, H.; Mazzitelli, G.

    1984-01-01

    The article is a rather detailed report on the highlights in the area of the ''Heating in toroidal plasmas'', as derived from the presentations and discussions at the international symposium with the same name, held in Rome, March 1984. The symposium covered both the physics (experiments and theory) and technology of toroidal fusion plasma heating. Both large fusion devices (either already in operation or near completion) requiring auxiliary heating systems at the level of tens of megawatts, as well as physics of their heating processes and their induced side effects (as studied on smaller devices), received attention. Substantial progress was reported on the broad front of auxiliary plasma heating and Ohmic heating. The presentation of the main conclusions of the symposium is divided under the following topics: neutral-beam heating, Alfven wave heating, ion cyclotron heating, lower hybrid heating, RF current drive, electron cyclotron heating, Ohmic heating and special contributions

  18. Resolution of concerns in auxiliary feedwater piping

    International Nuclear Information System (INIS)

    Bain, R.A.; Testa, M.F.

    1994-01-01

    Auxiliary feedwater piping systems at pressurized water reactor (PWR) nuclear power plants have experienced unanticipated operating conditions during plant operation. These unanticipated conditions have included plant events involving backleakage through check valves, temperatures in portions of the auxiliary feedwater piping system that exceed design conditions, and the occurrence of unanticipated severe fluid transients. The impact of these events has had an adverse effect at some nuclear stations on plant operation, installed plant components and hardware, and design basis calculations. Beaver Valley Unit 2, a three loop pressurized water reactor nuclear plant, has observed anomalies with the auxiliary feedwater system since the unit went operational in 1987. The consequences of these anomalies and plant events have been addressed and resolved for Beaver Valley Unit 2 by performing engineering and construction activities. These activities included pipe stress, pipe support and pipe rupture analysis, the monitoring of auxiliary feedwater system temperature and pressure, and the modification to plant piping, supports, valves, structures and operating procedures

  19. Radiofrequency attenuator and method

    Science.gov (United States)

    Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Hall, Simon B [Palmerston North, NZ

    2009-01-20

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  20. Electromagnetic field sources in radiofrequency

    International Nuclear Information System (INIS)

    Oliveira, C.; Sebastiao, D.; Ladeira, D.; Antunes, M.; Correia, L.M.

    2010-01-01

    In the scope of the monIT Project, several measurements were made of electromagnetic fields in Portugal. This paper presents an analysis of the sources operating in the radiofrequency range, resulting from 2429 measurements in 466 locations.

  1. Performance assessment of auxiliary bearing in HTR-10 AMB helium circulator on the event of rotor drop

    International Nuclear Information System (INIS)

    Xiao Zhen; Yang Guojun; Li Yue; Shi Zhengang; Yu Suyuan

    2014-01-01

    In this paper, a model for analyzing internal contact stress arid external load of ball bearing from rotor displacement was developed based on the Hertz contact theory and applied to the analysis of the rotor drop test in HTR-10 helium circulator equipped with AMB (Active Magnetic Bearing) to gain a better understanding of auxiliary bearing performance at different stages after the rotor drop. It was shown that the auxiliary bearing can well resist axial impact produced by rotor drop, avoiding of internal severe plastic deformation and damage to the performance of the auxiliary bearing. Rotor's rotary motion and the heat accumulation of the inner ring resulted from the initial acute acceleration are the main contributor of radial load during the rotor idling and may cause the failure of auxiliary bearing. This paper analyzed the influence of this load and confirmed that the auxiliary bearing can still work in its loading limits. (authors)

  2. 30 CFR 75.331 - Auxiliary fans and tubing.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans and tubing. 75.331 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.331 Auxiliary fans and tubing. (a) When auxiliary fans and tubing are used for face ventilation, each auxiliary fan shall be— (1...

  3. The Acquisition of Auxiliary Syntax: A Longitudinal Elicitation Study. Part 2: The Modals and Auxiliary DO

    Science.gov (United States)

    Rowland, Caroline F.; Theakston, Anna L.

    2009-01-01

    Purpose: The study of auxiliary acquisition is central to work on language development and has attracted theoretical work from both nativist and constructivist approaches. This study is part of a 2-part companion set that represents a unique attempt to trace the development of auxiliary syntax by using a longitudinal elicitation methodology. The…

  4. 78 FR 25916 - Authorization of Radiofrequency Equipment

    Science.gov (United States)

    2013-05-03

    ...] Authorization of Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Proposed rule... bodies, and measurement procedures used to determine RF equipment compliance. The Commission believes... Commission is responsible for an equipment authorization program for radiofrequency (RF) devices under part 2...

  5. Measurement of radiofrequency fields

    International Nuclear Information System (INIS)

    Leonowich, J.A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs

  6. Enhanced Radiofrequency Ablation With Magnetically Directed Metallic Nanoparticles.

    Science.gov (United States)

    Nguyen, Duy T; Tzou, Wendy S; Zheng, Lijun; Barham, Waseem; Schuller, Joseph L; Shillinglaw, Benjamin; Quaife, Robert A; Sauer, William H

    2016-05-01

    Remote heating of metal located near a radiofrequency ablation source has been previously demonstrated. Therefore, ablation of cardiac tissue treated with metallic nanoparticles may improve local radiofrequency heating and lead to larger ablation lesions. We sought to evaluate the effect of magnetic nanoparticles on tissue sensitivity to radiofrequency energy. Ablation was performed using an ablation catheter positioned with 10 g of force over prepared ex vivo specimens. Tissue temperatures were measured and lesion volumes were acquired. An in vivo porcine thigh model was used to study systemically delivered magnetically guided iron oxide (FeO) nanoparticles during radiofrequency application. Magnetic resonance imaging and histological staining of ablated tissue were subsequently performed as a part of ablation lesion analysis. Ablation of ex vivo myocardial tissue treated with metallic nanoparticles resulted in significantly larger lesions with greater impedance changes and evidence of increased thermal conductivity within the tissue. Magnet-guided localization of FeO nanoparticles within porcine thigh preps was demonstrated by magnetic resonance imaging and iron staining. Irrigated ablation in the regions with greater FeO, after FeO infusion and magnetic guidance, created larger lesions without a greater incidence of steam pops. Metal nanoparticle infiltration resulted in significantly larger ablation lesions with altered electric and thermal conductivity. In vivo magnetic guidance of FeO nanoparticles allowed for facilitated radiofrequency ablation without direct infiltration into the targeted tissue. Further research is needed to assess the clinical applicability of this ablation strategy using metallic nanoparticles for the treatment of cardiac arrhythmias. © 2016 American Heart Association, Inc.

  7. Builtin vs. auxiliary detection of extrapolation risk.

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Miles Arthur; Kegelmeyer, W. Philip,

    2013-02-01

    A key assumption in supervised machine learning is that future data will be similar to historical data. This assumption is often false in real world applications, and as a result, prediction models often return predictions that are extrapolations. We compare four approaches to estimating extrapolation risk for machine learning predictions. Two builtin methods use information available from the classification model to decide if the model would be extrapolating for an input data point. The other two build auxiliary models to supplement the classification model and explicitly model extrapolation risk. Experiments with synthetic and real data sets show that the auxiliary models are more reliable risk detectors. To best safeguard against extrapolating predictions, however, we recommend combining builtin and auxiliary diagnostics.

  8. The biological effects of quadripolar radiofrequency sequential application: a human experimental study.

    Science.gov (United States)

    Nicoletti, Giovanni; Cornaglia, Antonia Icaro; Faga, Angela; Scevola, Silvia

    2014-10-01

    An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model. Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening. The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radiofrequency applications were performed on human full-thickness skin and subcutaneous tissue specimens harvested during surgery for body contouring. In the in vivo assessments the applications were performed on two volunteer patients scheduled for body contouring surgery at the end of the study. The assessment methods were: clinical examination and medical photography, temperature measurement with thermal imaging scan, and light microscopy histological examination. The ex vivo assessments allowed for identification of the effective safety range for human application. The in vivo assessments allowed for demonstration of the biological effects of sequential radiofrequency applications. After a course of radiofrequency applications, the collagen fibers underwent an immediate heat-induced rearrangement and were partially denaturated and progressively metabolized by the macrophages. An overall thickening and spatial rearrangement was appreciated both in the collagen and elastic fibers, the latter displaying a juvenile reticular pattern. A late onset in the macrophage activation after sequential radiofrequency applications was appreciated. Our data confirm the effectiveness of sequential radiofrequency applications in obtaining attenuation of the skin wrinkles by an overall skin tightening.

  9. New-generation radiofrequency technology.

    Science.gov (United States)

    Krueger, Nils; Sadick, Neil S

    2013-01-01

    Radiofrequency (RF) technology has become a standard treatment in aesthetic medicine with many indications due to its versatility, efficacy, and safety. It is used worldwide for cellulite reduction; acne scar revision; and treatment of hypertrophic scars and keloids, rosacea, and inflammatory acne in all skin types. However, the most common indication for RF technology is the nonablative tightening of tissue to improve skin laxity and reduce wrinkles. Radiofrequency devices are classified as unipolar, bipolar, or multipolar depending on the number of electrodes used. Additional modalities include fractional RF; sublative RF; phase-controlled RF; and combination RF therapies that apply light, massage, or pulsed electromagnetic fields (PEMFs). This article reviews studies and case series on these devices. Radiofrequency technology for aesthetic medicine has seen rapid advancements since it was used for skin tightening in 2003. Future developments will continue to keep RF technology at the forefront of the dermatologist's armamentarium for skin tightening and rejuvenation.

  10. Curricular Guidelines for Dental Auxiliary Radiology.

    Science.gov (United States)

    Journal of Dental Education, 1981

    1981-01-01

    AADS curricular guidelines suggest objectives for these areas of dental auxiliary radiology: physical principles of X-radiation in dentistry, related radiobiological concepts, principles of radiologic health, radiographic technique, x-ray films and intensifying screens, factors contributing to film quality, darkroom, and normal variations in…

  11. Auxiliary power unit for moving a vehicle

    Science.gov (United States)

    Akasam, Sivaprasad [Peoria, IL; Johnson, Kris W [Peoria, IL; Johnson, Matthew D [Peoria, IL; Slone, Larry M [Washington, IL; Welter, James Milton [Chillicothe, IL

    2009-02-03

    A power system is provided having at least one traction device and a primary power source configured to power the at least one traction device. In addition, the power system includes an auxiliary power source also configured to power the at least one traction device.

  12. Computation within the auxiliary field approach

    International Nuclear Information System (INIS)

    Baeurle, S.A.

    2003-01-01

    Recently, the classical auxiliary field methodology has been developed as a new simulation technique for performing calculations within the framework of classical statistical mechanics. Since the approach suffers from a sign problem, a judicious choice of the sampling algorithm, allowing a fast statistical convergence and an efficient generation of field configurations, is of fundamental importance for a successful simulation. In this paper we focus on the computational aspects of this simulation methodology. We introduce two different types of algorithms, the single-move auxiliary field Metropolis Monte Carlo algorithm and two new classes of force-based algorithms, which enable multiple-move propagation. In addition, to further optimize the sampling, we describe a preconditioning scheme, which permits to treat each field degree of freedom individually with regard to the evolution through the auxiliary field configuration space. Finally, we demonstrate the validity and assess the competitiveness of these algorithms on a representative practical example. We believe that they may also provide an interesting possibility for enhancing the computational efficiency of other auxiliary field methodologies

  13. Vacuum switchgear for power station auxiliary switchboards

    International Nuclear Information System (INIS)

    Coombs, P.E.

    1992-01-01

    Sizewell B is the first UK power station in which vacuum switchgear is used for the auxiliary switchboards. Previously the 3.3kV, 6.6kV or 11kV switchgear has used air-break circuit breakers and fused air-break contactors, known as motor starting devices or fused switching devices (FSD). The use of vacuum interrupters is therefore a new technology in this application, although it has been established in the UK distribution network and in industrial installations from the mid 1970s. Vacuum switchgear was already in use in the USA for power station auxiliary switchgear at the time that it was proposed for Sizewell B. The Sizewell B high voltage auxiliary switchgear comprises eight Unit and Station Auxiliary Switchboards at 3.3kV and 11kV, and four 3.3kV Essential Switchboards for the essential safety related circuits, making a total of 65 circuit breakers plus FSD panels. (Author)

  14. Aging assessment of auxiliary feedwater systems

    International Nuclear Information System (INIS)

    Casada, D.A.

    1989-01-01

    A study of Pressurized Water Reactor Auxiliary Feedwater (AFW) Systems has been conducted by Oak Ridge National Laboratory (ORNL) under the auspices of the Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. The study has reviewed historical failure experience and current monitoring practices for the AFW System. This paper provides an overview of the study approach and results. 7 figs

  15. Design and Experiment of Auxiliary Bearing for Helium Blower of HTR-PM

    International Nuclear Information System (INIS)

    Yang Guojun; Shi Zhengang; Liu Xingnan; Zhao Jingjing

    2014-01-01

    The helium blower is the important equipment for HTR-PM. Active magnetic bearing (AMB) instead of mechanical bearing is selected to support the rotor of the helium blower. However, one implication of AMB is the requirement to provide the auxiliary bearing to mitigate the effects of failures or overload conditions. The auxiliary bearing is used to support the rotor when the AMB fails to work. It must support the dropping rotor and bear the great impact force and friction heat. The design of the auxiliary bearing is one of the challenging problems in the whole system. It is very important for the helium blower with AMB of HTR-PM to make success. The rotor’s length of helium blower of HTR-PM is about 3.3 m, its weight is about 4000 kg and the rotating speed is 4000 r/min. The axial load is 4500kg, and the radial load is 1950kg. The angular contact ball bearing was selected as the auxiliary bearing. The test rig has been finished. It is difficult to analyze the falling course of the rotor. The preliminary analysis of the dropping rotor was done in the special condition. The impact force of auxiliary bearing was computed for the axial and radial load. And the dropping test of the blower rotor for HTR-10 will be introduced also in this paper. Results offer the important theoretical base for the protector design of the helium blower with AMB for HTR-PM. (author)

  16. Estimation of the electrical power needed for LHC magnets and radiofrequency at 7 TeV

    CERN Document Server

    Thiesen, H; Burnet, J P

    2012-01-01

    The purpose of this paper is to provide the electrical power needed from the grid for the power converters feeding the magnets (superconducting, warm and experiments) and the radiofrequency of the LHC. At 4 TeV, the active power required for the magnets is 17.6MW and the estimation is 25.5MW at 7 TeV. The active power needed for the radiofrequency depends on the beam intensity and on the bunch spacing. It will grow from 7MW to 10MW with 25ns bunch spacing operation. This does not include the power needed for the cryogenic and magnet auxiliary systems. This paper gives also the instantaneous profile of the power needed from the grid during the ramp and the reactive power which needs to be compensated by the static VAR compensators.

  17. Bipolar and monopolar radiofrequency treatment of osteoarthritic knee articular cartilage: acute and temporal effects on cartilage compressive stiffness, permeability, cell synthesis, and extracellular matrix composition.

    Science.gov (United States)

    Cook, James L; Kuroki, Keiichi; Kenter, Keith; Marberry, Kevin; Brawner, Travis; Geiger, Timothy; Jayabalan, Prakash; Bal, B Sonny

    2004-04-01

    The cellular, biochemical, biomechanical, and histologic effects of radiofrequency-generated heat on osteoarthritic cartilage were assessed. Articular cartilage explants (n=240) from 26 patients undergoing total knee arthroplasty were divided based on Outerbridge grade (I or II/III) and randomly assigned to receive no treatment (controls) or monopolar or bipolar radiofrequency at 15 or 30 W. Both potentially beneficial and harmful effects of radiofrequency treatment of articular cartilage were noted. It will be vital to correlate data from in vitro and in vivo study of radiofrequency thermal chondroplasty to determine the clinical usefulness of this technique.

  18. Radiofrequency fields in our surroundings

    International Nuclear Information System (INIS)

    2011-01-01

    In 2010, the National Radiation Protection Authority (NRPA) with the Post and Telecommunications Authority carried out a project where it is measured radiofrequency fields from various telecom systems in homes, kindergartens, schools, offices, and urban environments. Close to 99 percent of the measurement points were found values of less than one thousandth of the maximum. No values were near the limits. (AG)

  19. The English Primary Auxiliary Verbs: A Linguistic Theoretical Exercise

    African Journals Online (AJOL)

    Nekky Umera

    Abstract. Obviously, the fact remains that English Language is a sensitive Language ... Even though the English auxiliary verbs are of two kinds: Primary and Modal auxiliary ..... Therefore we are of the opinion that most speakers lack adequate.

  20. Design and scope of impact of auxiliary lanes : technical report.

    Science.gov (United States)

    2014-06-01

    For decades, Texas Department of Transportation districts have constructed auxiliary lanes to support interchange : ramp operations and to resolve congestion proximate to freeway entrance and exit ramps. While auxiliary lanes are : built throughout T...

  1. 14 CFR 29.757 - Hull and auxiliary float strength.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand the...

  2. 30 CFR 57.8529 - Auxiliary fan systems

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fan systems 57.8529 Section 57.8529 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Underground Only § 57.8529 Auxiliary fan systems When auxiliary fan systems are used, such systems shall...

  3. Bayesian Analysis of Geostatistical Models With an Auxiliary Lattice

    KAUST Repository

    Park, Jincheol; Liang, Faming

    2012-01-01

    of observations is large. In this article, we propose an auxiliary lattice-based approach for tackling this difficulty. By introducing an auxiliary lattice to the space of observations and defining a Gaussian Markov random field on the auxiliary lattice, our model

  4. Radiofrequency power deposition during magnetic resonance diagnostic examinations

    International Nuclear Information System (INIS)

    Grandolfo, M.; Vecchia, P.

    1988-01-01

    Magnetic Resonance Imaging and Spectroscopy (MRI, MRS) require that subjects be exposed to radiofrequency field, and the corresponding energy absorption leads to tissue heating. The main question, thus, to be considered in connection to safety and health aspects is related to the specific absorption rate (SAR) in the imaged subject and the exposure durations which might put a practical limit on the pulse sequence which can be used. In this paper some models and experimental results for radiofrequency power deposition in MRI and MRS machines are reviewed. Models show that energy dissipation is a function of the frequency, RF incident power density, exposure duration, coupling between the RF coil and the subject, and several properties of the exposed tissue, including conductivity, dielectric constant, specific gravity, size, and orientation relative to the field polarization. The ability of the body's normal thermoregulatory responses to cope with high levels of RF energy deposition must be also taken into account

  5. Novel high-resolution temperature probe for radiofrequency dosimetry

    International Nuclear Information System (INIS)

    Schuderer, Juergen; Schmid, Thomas; Urban, Gerald; Samaras, Theodoros; Kuster, Niels

    2004-01-01

    A novel integrated thermistor probe for temperature evaluations in radiofrequency-heated environments was realized. The probe's sensitive area is based on a highly resistive 50 μm x 100 μm layer of amorphous germanium processed on a glass tip. The small dimensions allow measurements with a distance as close as 150 μm from solid boundaries. Due to its high temperature resolution of 4 mK and its short response time of the order of 10 ms, the sensor is very well suited for dosimetric measurements in strong absorption gradients. The influence of radiofrequency (RF) electric fields on the signal is minimized due to the high resistance of the sensor and the leads. The probe was successfully used to determine the highly nonuniform absorption distribution resulting from the RF exposure of cell cultures placed in Petri dishes. (note)

  6. Novel high-resolution temperature probe for radiofrequency dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Schuderer, Juergen [Foundation for Research on Information Technologies in Society (IT' IS), Integrated Systems Laboratory IIS, Swiss Federal Institute of Technology (ETH), CH-8092 Zurich (Switzerland); Schmid, Thomas [Schmid and Partner Engineering AG, 8004 Zurich (Switzerland); Urban, Gerald [IMTEK, Albert-Ludwigs University Freiburg, 79110 Freiburg (Germany); Samaras, Theodoros [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kuster, Niels [Foundation for Research on Information Technologies in Society (IT' IS), Integrated Systems Laboratory IIS, Swiss Federal Institute of Technology (ETH), CH-8092 Zurich (Switzerland)

    2004-03-21

    A novel integrated thermistor probe for temperature evaluations in radiofrequency-heated environments was realized. The probe's sensitive area is based on a highly resistive 50 {mu}m x 100 {mu}m layer of amorphous germanium processed on a glass tip. The small dimensions allow measurements with a distance as close as 150 {mu}m from solid boundaries. Due to its high temperature resolution of 4 mK and its short response time of the order of 10 ms, the sensor is very well suited for dosimetric measurements in strong absorption gradients. The influence of radiofrequency (RF) electric fields on the signal is minimized due to the high resistance of the sensor and the leads. The probe was successfully used to determine the highly nonuniform absorption distribution resulting from the RF exposure of cell cultures placed in Petri dishes. (note)

  7. Combined kinetic and transport modeling of radiofrequency current drive

    International Nuclear Information System (INIS)

    Dumont, R.; Giruzzi, G.; Barbato, E.

    2000-07-01

    A numerical model for predictive simulations of radiofrequency current drive in magnetically confined plasmas is developed. It includes the minimum requirements for a self consistent description of such regimes, i.e., a 3-D ,kinetic equation for the electron distribution function, 1-D heat and current transport equations, and resonant coupling between velocity space and configuration space dynamics, through suitable wave propagation equations. The model finds its full application in predictive studies of complex current profile control scenarios in tokamaks, aiming at the establishment of internal transport barriers by the simultaneous use of various radiofrequency current drive methods. The basic properties of this non-linear numerical system are investigated and illustrated by simulations applied to reversed magnetic shear regimes obtained by Lower Hybrid and Electron Cyclotron current drive for parameters typical of the Tore Supra tokamak. (authors)

  8. WORKSHOP: Radiofrequency superconductivity

    International Nuclear Information System (INIS)

    Tückmantel, Joachim

    1993-01-01

    Full text: With superconducting radiofrequency playing a major role in the push for new machines to break fresh physics frontiers, it has become a tradition for experts and newcomers in this field from all over the world to meet every second year to hear progress reports from laboratories and to discuss common problems and possible solutions. The sixth such workshop was held from 4-8 October under the chairmanship of Ron Sundelin at the Continuous Electron Beam Accelerator Facility (CEBAF) under construction in Newport News, Virginia. With 170 participants from 14 countries including Eastern Europe and China, it reflected the growing interest in the field - looking back to 1984, when CERN was the host laboratory, the second workshop had less than 100 participants. The CEBAF meeting began with laboratory status reports, covering both high beam energy ('high beta') applications with 'spherical' cavities (as with CERN's LEP200), all using niobium as superconductor and working between 352 MHz and 3 GHz, and lower energy (low beta') applications with geometrically more complicated shapes such as quarter or half wave, split ring or spoke resonators, some using electrodeposited lead as superconductor and working around 100 MHz. During these talks it became clear that more and more laboratories have focused on routine problems, such as reliable series production and testing, running cavities with ancillaries in the machines, or building complete prototypes for projects to be approved by critical funding authorities. This contrasts with the heady days just a few years ago when - at least in the high beta community - the main objective was to explore new ideas. State-of-the-art summaries showed how at 1.3 and 3 GHz 25-30 MV/m have been reached by several laboratories using different preparation methods. Newer developments for common problems included r.f. windows, couplers, controls, and especially field emission, public enemy number one for

  9. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2003-01-01

    The NCSX (National Compact Stellarator Experiment) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral-beam injection, and radio-frequency. Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The plan is to provide 3 MW of 50 keV balanced neutral-beam tangential injection with pulse lengths of 500 msec for initial experiments, and to be upgradeable to pulse lengths of 1.5 sec. Subsequent upgrades will add 3 MW of neutral-beam injection. This Chapter discusses the NCSX neutral-beam injection requirements and design issues, and shows how these are provided by the candidate PBX-M (Princeton Beta Experiment-Modification) neutral-beam injection system. In addition, estimations are given for beam-heating efficiencies, scaling of heating efficiency with machine size an d magnetic field level, parameter studies of the optimum beam-injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of radio-frequency heating by mode-conversion ion-Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron-cyclotron heating. The initial MCIBW heating technique and the design of the radio-frequency system lend themselves to current drive, so that if current drive became desirable for any reason only minor modifications to the heating system described here would be needed. The radio-frequency system will also be capable of localized ion heating (bulk or tail), and possibly ion-Bernstein-wave-generated sheared flows

  10. Modified Darboux transformations with foreign auxiliary equations

    International Nuclear Information System (INIS)

    Schulze-Halberg, Axel

    2011-01-01

    We construct a new type of first-order Darboux transformations for the stationary Schroedinger equation. In contrast to the conventional case, our Darboux transformations support arbitrary (foreign) auxiliary equations. We show that among other applications, our formalism can be used to systematically construct Darboux transformations for Schroedinger equations with energy-dependent potentials, including a recent result (Lin et al., 2007) as a special case. -- Highlights: → We generalize the Darboux transformation for the Schroedinger equation. → By admitting arbitrary auxiliary functions, we provide a new tool for generating solutions. → As a special case we recover a recent result on energy-dependent potentials. → We extend the latter result to very general energy-dependence.

  11. Eigenstates with the auxiliary field method

    Energy Technology Data Exchange (ETDEWEB)

    Semay, Claude [Service de Physique Nucleaire et Subnucleaire, Universite de Mons-UMONS, 20 Place du Parc, 7000 Mons (Belgium); Silvestre-Brac, Bernard, E-mail: claude.semay@umons.ac.b, E-mail: silvestre@lpsc.in2p3.f [LPSC Universite Joseph Fourier, Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, Avenue des Martyrs 53, F-38026 Grenoble-Cedex (France)

    2010-07-02

    The auxiliary field method is a powerful technique to obtain approximate closed-form energy formulas for eigenequations in quantum mechanics. Very good results can be obtained for Schroedinger and semirelativistic Hamiltonians with various potentials, even in the case of many-body problems. This method can also provide approximate eigenstates in terms of well-known wavefunctions, for instance harmonic oscillator or hydrogen-like states, but with a characteristic size which depends on quantum numbers. In this paper, we consider two-body Schroedinger equations with linear, logarithmic and exponential potentials and show that analytical approximations of the corresponding eigenstates can be obtained with the auxiliary field method, with very good accuracy in some cases.

  12. Eigenstates with the auxiliary field method

    International Nuclear Information System (INIS)

    Semay, Claude; Silvestre-Brac, Bernard

    2010-01-01

    The auxiliary field method is a powerful technique to obtain approximate closed-form energy formulas for eigenequations in quantum mechanics. Very good results can be obtained for Schroedinger and semirelativistic Hamiltonians with various potentials, even in the case of many-body problems. This method can also provide approximate eigenstates in terms of well-known wavefunctions, for instance harmonic oscillator or hydrogen-like states, but with a characteristic size which depends on quantum numbers. In this paper, we consider two-body Schroedinger equations with linear, logarithmic and exponential potentials and show that analytical approximations of the corresponding eigenstates can be obtained with the auxiliary field method, with very good accuracy in some cases.

  13. Auxiliary facilities on nuclear ship 'MUTSU'

    International Nuclear Information System (INIS)

    Tsujimura, Shotaro; Takigami, Yoshio.

    1989-01-01

    The nuclear ship 'MUTSU' has been moored at SEKINEHAMA, MUTU City in AOMORI Prefecture and several tests and works are being carried out on the ship. The construction of the auxiliary facilities for these works on the ship was completed in safety in August 1988. After that the facilities have fulfilled their function. The outlines of design, fabrication and construction of the facilities are described in this paper. (author)

  14. Categorical Data Fusion Using Auxiliary Information

    OpenAIRE

    Fosdick, Bailey K.; DeYoreo, Maria; Reiter, Jerome P.

    2015-01-01

    In data fusion, analysts seek to combine information from two databases comprised of disjoint sets of individuals, in which some variables appear in both databases and other variables appear in only one database. Most data fusion techniques rely on variants of conditional independence assumptions. When inappropriate, these assumptions can result in unreliable inferences. We propose a data fusion technique that allows analysts to easily incorporate auxiliary information on the dependence struc...

  15. Radiofrequency power in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This document includes the various communications that were presented at the 11th topical conference on radio frequency power in plasmas which took place in Palm Springs in May 1995. It includes current diffusion studies to assess the non-inductive current deposition profiles, experiments for plasma to reach quickly an equilibrium state, and modelling of electrons in plasma. Some comparison studies also reveal the efficiency of the Quasi-Optical Grill antenna for reactor applications. Finally, a scenario for efficient mode conversion heating in the ion cyclotron range of frequency is presented. Separate abstracts were prepared for the 6 papers in this volume. (TEC).

  16. Solar/electric heating systems for the future energy system

    DEFF Research Database (Denmark)

    Furbo, Simon; Dannemand, Mark; Perers, Bengt

    elements/heat pump, advanced heat storage tanks and advanced control systems. Heat is produced by solar collectors in sunny periods and by electrical heating elements/heat pump. The electrical heating elements/heat pump will be in operation in periods where the heat demand cannot be covered by solar energy....... The aim is to use the auxiliary heating units when the electricity price is low, e.g. due to large electricity production by wind turbines. The unit is equipped with an advanced control system where the control of the auxiliary heating is based on forecasts of the electricity price, the heat demand...

  17. Radiofrequency Ablation of Hepatic Cysts : Case Report

    International Nuclear Information System (INIS)

    Lee, Ye Ri; Kim, Pyo Nyun

    2005-01-01

    Radiofrequency ablation has been frequently performed on intra-hepatic solid tumor, namely, hepatocellular carcinoma, metastatic tumor and cholangio carcinoma, for take the cure. But, the reports of radiofrequency ablation for intrahepatic simple cysts are few. In vitro experiment of animal and in vivo treatment for intrahepatic cysts of human had been reported in rare cases. We report 4 cases of radiofrequency ablation for symptomatic intrahepatic cysts

  18. Superconducting Radio-Frequency Cavities

    Science.gov (United States)

    Padamsee, Hasan S.

    2014-10-01

    Superconducting cavities have been operating routinely in a variety of accelerators with a range of demanding applications. With the success of completed projects, niobium cavities have become an enabling technology, offering upgrade paths for existing facilities and pushing frontier accelerators for nuclear physics, high-energy physics, materials science, and the life sciences. With continued progress in basic understanding of radio-frequency superconductivity, the performance of cavities has steadily improved to approach theoretical capabilities.

  19. Cutaneous remodeling and photorejuvenation using radiofrequency devices

    Directory of Open Access Journals (Sweden)

    Elsaie Mohamed

    2009-01-01

    Full Text Available Radio frequency (RF is electromagnetic radiation in the frequency range of 3-300GHz. The primary effects of RF energy on living tissue are considered to be thermal. The goal of the new devices based on these frequency ranges is to heat specific layers of the skin. The directed use of RF can induce dermal heating and cause collagen degeneration. Wound healing mechanisms promote the remodeling of collagen and wound contraction, which ultimately clinically enhances the appearance of mild to moderate skin laxity. Preliminary studies have reported efficacy in the treatment of laxity that involves the periorbital area and jowls. Because RF energy is not dependent on specific chromophore interaction, epidermal melanin is not at risk of destruction and treatment of all skin types is possible. As such, radiofrequency-based systems have been used successfully for nonablative skin rejuvenation, atrophic scar revision and treatment of unwanted hair, vascular lesions and inflammatory acne. The use of RF is becoming more popular, although a misunderstanding exists regarding the mechanisms and limitations of its actions. This concise review serves as an introduction and guide to many aspects of RF in the non ablative rejuvenation of skin.

  20. Radiofrequency (RF) radiation measurement for diathermy machine

    International Nuclear Information System (INIS)

    Rozaimah Abdul Rahim; Roha Tukimin; Mohd Amirul Nizam; Ahmad Fadzli; Mohd Azizi

    2010-01-01

    Full-text: Diathermy machine is one of medical device that use widely in hospital and clinic. During the diathermy treatment, high radiofrequency (RF) currents (shortwave and microwave) are used to heat deep muscular tissues through electromagnetic energy to body tissues. The heat increases blood flow, relieve pain and speeding up recovery. The stray RF radiation from the machine can exposes to unintended tissue of the patient, to the operator (physical therapist) and also can cause electromagnetic interference (EMI) effect to medical devices around the machine. The main objective of this study is to establish a database of the RF radiation exposure levels experienced by the operator and patient during the treatments. RF radiation (electric and magnetic field) produced by the diathermy machines were measured using special RF survey meters. The finding of this study confirms that radiation levels on the surface and near the applicator of the diathermy machine much more elevated due to the much closer distance to the source and they exceeding the occupational and general public exposure limit. The results also shows the field strengths drop very significantly when the distance of measurement increase. (author)

  1. System Study: Auxiliary Feedwater 1998-2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-12-01

    This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AFW results.

  2. Hyperkalaemia after radiofrequency ablation of hepatocellular carcinoma

    NARCIS (Netherlands)

    Verhoevena, BH; Haagsma, EB; Appeltans, BMG; Slooff, MJH; de Jong, KP

    Radiofrequency ablation of liver tumours is a useful therapy for otherwise unresectable tumours. The complication rate is said to be low. In this case report we describe hyperkalaemia after radiofrequency ablation of a hepatocellular carcinoma in a patient with end-stage renal insufficiency. (C)

  3. Predicting nurses' acceptance of radiofrequency identification technology.

    Science.gov (United States)

    Norten, Adam

    2012-10-01

    The technology of radiofrequency identification allows for the scanning of radiofrequency identification-tagged objects and individuals without line-of-sight requirements. Healthcare organizations use radiofrequency identification to ensure the health and safety of patients and medical personnel and to uncover inefficiencies. Although the successful implementation of a system incorporating radiofrequency identification technologies requires acceptance and use of the technology, some nurses using radiofrequency identification in hospitals feel like "Big Brother" is watching them. This predictive study used a theoretical model assessing the effect of five independent variables: privacy concerns, attitudes, subjective norms, controllability, and self-efficacy, on a dependent variable, nurses' behavioral intention to use radiofrequency identification. A Web-based questionnaire containing previously validated questions was answered by 106 US RNs. Multiple linear regression showed that all constructs together accounted for 60% of the variance in nurses' intention to use radiofrequency identification. Of the predictors in the model, attitudes provided the largest unique contribution when the other predictors in the model were held constant; subjective norms also provided a unique contribution. Privacy concerns, controllability, and self-efficacy did not provide a significant contribution to nurses' behavioral intention to use radiofrequency identification.

  4. Auxiliary equipment cooling circuit in nuclear reactors

    International Nuclear Information System (INIS)

    Yanagisawa, Ko.

    1986-01-01

    Purpose: To prevent the propagation of bacterias that transform NO 2 into NO 3 in auxiliary equipment coolants using corrosion inhibitors of nitrite type in BWR type reactors. Method: In auxiliary equipments coolant systems, water quality is controlled by using purified water as supplement water and nitrite such as Na 2 NO 2 as the corrosion inhibitors. However, in the circumstance where dissolved oxygen is present, bacteria propagate to oxidize NO 2 into NO 3 . Thus, NO 2 at 200 ppm is reduced to 20 ppm. In view of the above, a surge tank supplied from water supplement line is connected in series and a deaeration device is disposed thereto. Since the presence of dissolved oxygen causes the bacteria to propagate it is desired that the dissolved oxygen density in the supplement water is less than 5 ppm. Deaeration and pressure reduction in the surge tank can remove the dissolved oxygen, prevent NO 3 increase and also prevent stress corrosion cracks in the system pipeways. (Horiuchi, T.)

  5. Measurement and modelling of a radiofrequency micro-thruster

    International Nuclear Information System (INIS)

    Charles, C; Boswell, R W

    2012-01-01

    A capacitively coupled radiofrequency (rf) (13.56 MHz) cylindrical argon micro-discharge expanding into a larger glass tube is studied by performing optical and electrical measurements over a pressure range 0.3–5 Torr and a rf power range 5–40 W. Measurements of the axial and radial plasma density profiles at the Paschen minimum near 1.5 Torr are used to develop a global model of the discharge and estimate neutral heating from ion–neutral charge exchange collisions for micro-propulsion applications. (fast track communication)

  6. Experimental and clinical studies with radiofrequency-induced thermal endometrial ablation for functional menorrhagia

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, J.H.; Lewis, B.V.; Prior, M.V.; Roberts, T. (Watford General Hospital, Herts (England))

    1990-11-01

    A method of ablating the endometrium has been introduced into clinical practice that uses radiofrequency electromagnetic energy to heat the endometrium, using a probe inserted through the cervix. Preliminary studies suggest that over 80% of patients treated will develop either amenorrhea or a significant reduction in flow. The advantages of radiofrequency endometrial ablation over laser ablation or resection are the avoidance of intravascular fluid absorption, simplicity (no special operative hysteroscopic skills are required), speed of operation, and reduced cost compared with the Nd:YAG laser. In this paper, we describe the experimental studies performed during development of this new technique.

  7. Pulsed radiofrequency microwave fields around a quadrupole particle accelerator: measurement and safety evaluation

    International Nuclear Information System (INIS)

    Sachdev, R.N.; Swarup, G.; Rajan, K.K.; Joseph, L.

    1996-01-01

    Pulsed radiofrequency microwave radiation (RFMR) fields occur during the use of high power microwaves in plasma heating in fusion research, plasma and solid state diagnostics, particle accelerators and colliders, pump sources in lasers, material processing as well as in high power radars. This paper describes the experimental work done at Trombay for measurement of pulsed RFMR fields in the working area of a radiofrequency quadrupole (RFQ) accelerator with the use of a meter calibrated in continuous field and interprets the observed fields in the light of existing protection criteria for pulsed RFMR fields. (author)

  8. Thermistor guided radiofrequency ablation of atrial insertion sites in patients with accessory pathways.

    Science.gov (United States)

    Tracy, C M; Moore, H J; Solomon, A J; Rodak, D J; Fletcher, R D

    1995-11-01

    Radiofrequency ablation has gained acceptance in the treatment of patients with symptomatic Wolff-Parkinson-White syndrome. The purpose of this study was to characterize the relation between temperature and other electroconductive parameters in patients undergoing atrial insertion accessory pathway ablation utilizing a thermistor equipped catheter. The mean temperature and power at sites of atrial insertion ablation are lower than has been previously associated with creation of radiofrequency lesions in the ventricle. While high cavitary blood flow in the atrium may result in cooling, the thinner atrial tissue may require less energy to achieve adequate heating than ventricular myocardium.

  9. Radio-Frequency Applications for Food Processing and Safety.

    Science.gov (United States)

    Jiao, Yang; Tang, Juming; Wang, Yifen; Koral, Tony L

    2018-03-25

    Radio-frequency (RF) heating, as a thermal-processing technology, has been extending its applications in the food industry. Although RF has shown some unique advantages over conventional methods in industrial drying and frozen food thawing, more research is needed to make it applicable for food safety applications because of its complex heating mechanism. This review provides comprehensive information regarding RF-heating history, mechanism, fundamentals, and applications that have already been fully developed or are still under research. The application of mathematical modeling as a useful tool in RF food processing is also reviewed in detail. At the end of the review, we summarize the active research groups in the RF food thermal-processing field, and address the current problems that still need to be overcome.

  10. Comparison of auxiliary feedwater and EDRS operation during natural circulation of MRX

    International Nuclear Information System (INIS)

    Kim, Jae Hak; Park, Goon Cherl

    1997-01-01

    The MRX is an integral type ship reactor with 100 MWt power, which is designed by Japan Atomic Energy Research Institute. It is characterized by integral type PWR, in-vessel type control rod drive mechanism, water-filled containment vessel and passive decay heat removal system. Marine reactor should have high passive safety. Therefore, in this study, we simulated the loss of flow accident to verify the passive decay heat removal by natural circulation using RETRAN-03 code. auxiliary feed water systems are used for decay heat removal mechanism and results are compared with the loss of flow accident analysis using emergency decay heat removal system by JAERI. Results are very similar to case of EDRS 1 loop operation in JAERI analysis and decay heat is successfully removed by natural circulation

  11. Three story residence with solar heat--Manchester, New Hampshire

    Science.gov (United States)

    1981-01-01

    When heat lost through ducts is counted for accurate performance assessment, solar energy supplied 56 percent of building's space heating load. Average outdoor temperature was 53 degrees F; average indoor temperature was 69 degrees F. System operating modes included heating from solar collectors, storing heat, heating from storage, auxiliary heating with oil fired furnace, summer venting, and hot water preheating.

  12. 47 CFR 2.801 - Radiofrequency device defined.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency device defined. 2.801 Section 2... MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency device defined. As used in this part, a radiofrequency device is any device which in its operation is capable of...

  13. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

  14. Evaluation of radiofrequency dielectric heaters workers exposure

    International Nuclear Information System (INIS)

    Benes, M.; Del Frate, S.; Villalta, R.

    2008-01-01

    Radiofrequency dielectric heaters (RFDH) are widely used in the woodworking industry for gluing laminates by applying pressure and RF heating. The workers operating such equipment remain in the vicinity of the machinery all day and can therefore be exposed to considerable levels of electric and magnetic field at RFs. This work describes the method used to measure the strength of fields generated by this particular machinery. This procedure is based on current methods cited in the literature and introduces the necessary modifications to meet this specific case. In particular, as there is often a scarcity of technical data available relating to such heaters, it is suggested that a spectrum analyser be used for measurements in the frequencies domain. On the basis of the data obtained the norms of reference are established, the instrumentation to be used in successive stages determined as well as the identification of possible sources of interference from spurious signals. Furthermore, a mapping of the field strengths is presented and the means of determining the decay curve as a function of distance. This last type of measurement is done to estimate the effectiveness of grounding the machinery. The report ends with an estimate of the exposure of workers to electromagnetic fields and also some recommendations for reducing risk. (authors)

  15. Metallic implants and exposure to radiofrequency radiation

    International Nuclear Information System (INIS)

    Joyner, K.H.; Fleming, A.H.F.; MacFarlane, I.P.; Hocking, B.

    1988-01-01

    There is increasing use of radiofrequency radiation (RFR) in industry for communications, welding, security, radio, medicine, navigation etc. It has been recognised for some years that RFR may interact with cardiac pacemakers and steps have been taken to prevent this interference. It is less well recognised that other metallic implants may also act as antennas in an RFR field and possibly cause adverse health effects by heating local tissues. There are a large and increasing number of implants having metal components which may be found in RFR workers. These implants include artificial joints, rods and plates used in orthopaedics, rings in heart valves, wires in sutures, bionic ears, subcutaneous infusion systems and (external) transdermal drug delivery patches 1 . The physician concerned with job placement of such persons requires information on the likelihood of an implant interacting with RFR so as to impair health. The following outlines the approach developed in Telecom Australia, beginning with the general principles and then presenting a specific example discussion of a specific example

  16. Radiofrequency facial rejuvenation: evidence-based effect.

    Science.gov (United States)

    el-Domyati, Moetaz; el-Ammawi, Tarek S; Medhat, Walid; Moawad, Osama; Brennan, Donna; Mahoney, My G; Uitto, Jouni

    2011-03-01

    Multiple therapies involving ablative and nonablative techniques have been developed for rejuvenation of photodamaged skin. Monopolar radiofrequency (RF) is emerging as a gentler, nonablative skin-tightening device that delivers uniform heat to the dermis at a controlled depth. We evaluated the clinical effects and objectively quantified the histologic changes of the nonablative RF device in the treatment of photoaging. Six individuals of Fitzpatrick skin type III to IV and Glogau class I to II wrinkles were subjected to 3 months of treatment (6 sessions at 2-week intervals). Standard photographs and skin biopsy specimens were obtained at baseline, and at 3 and 6 months after the start of treatment. We performed quantitative evaluation of total elastin, collagen types I and III, and newly synthesized collagen using computerized histometric and immunohistochemical techniques. Blinded photographs were independently scored for wrinkle improvement. RF produced noticeable clinical results, with high satisfaction and corresponding facial skin improvement. Compared with the baseline, there was a statistically significant increase in the mean of collagen types I and III, and newly synthesized collagen, while the mean of total elastin was significantly decreased, at the end of treatment and 3 months posttreatment. A limitation of this study is the small number of patients, yet the results show a significant improvement. Although the results may not be as impressive as those obtained by ablative treatments, RF is a promising treatment option for photoaging with fewer side effects and downtime. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  17. Steady state flow evaluations for passive auxiliary feedwater system of APR

    International Nuclear Information System (INIS)

    Park, Jongha; Kim, Jaeyul; Seong, Hoje; Kang, Kyoungho

    2012-01-01

    This paper briefly introduces a methodology to evaluate steady state flow of APR+ Passive Auxiliary Feedwater System (PAFS). The PAFS is being developed as a safety grade passive system to completely replace the existing active Auxiliary Feedwater System (AFWS). Natural circulation cooling can be generally classified into the single-phase, two-phase, and boiling-condensation modes. The PAF is designed to be operated in a boiling-condensation natural circulation mode. The steady-state flow rate should be equal to the steady-state boiling/condensation rate determined by the steady-state energy and momentum balances in the PAFS. The determined steady-state flow rate can be used in the design optimization for the natural circulation loop of the PAFS through the steady-state momentum balance. Since the retarding force, which is to be balanced by the driving force in the natural circulation system design depends on the reliable evaluation of the success of a natural circulation system design depends on the reliable evaluation of the pressure loss coefficients. In PAFS, the core decay heat is released by natural circulation flow between the S G secondary side and the Passive Condensation Heat Exchanger (PCHX) that is immersed in the Passive Condensation Cooling Tank (PCCT). The PCCT is located on the top of Auxiliary building The driving force is determined by the difference between the S/G (heat Source) secondary water level and condensation liquid (heat sink) level. It will overcome retarding force at flowrate in the system, which is determined by vaporization and condensation of the steam which is generated at the S/G by the latent heat in system. In this study, the theoretical method to estimate the steady state flow rate in boiling-condensation natural circulation system is developed and compared with test results

  18. Auxiliary Electrodes for Chromium Vapor Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Fergus, Jeffrey; Shahzad, Moaiz; Britt, Tommy

    2018-05-15

    Measurement of chromia-containing vapors in solid oxide fuel cell systems is useful for monitoring and addressing cell degradation caused by oxidation of the chomia scale formed on alloys for interconnects and balance-of-plant components. One approach to measuring chromium is to use a solid electrolyte with an auxiliary electrode that relates the partial pressure of the chromium containing species to the mobile species in the electrolyte. One example is YCrO3 which can equilibrate with the chromium containing vapor and yttrium in yttria stabilized zirconia to establish an oxygen activity. Another is Na2CrO4 which can equilibrate with the chromium-containing vapor to establish a sodium activity.

  19. Auxiliary accelerating system for TRIUMF cyclotron

    International Nuclear Information System (INIS)

    Zach, M.; Fong, K.; Laxdal, R.; Mackenzie, G.H.; Pacak, V.; Pearson, J.; Richardson, J.R.; Stanford, G.; Worsham, R.

    1990-06-01

    A 92 MHz auxiliary accelerating cavity has been designed and manufactured for installation in the TRIUMF cyclotron. Operating at the fourth harmonic of the RF with a peak voltage of 150 kV, it almost doubles the present energy gain per turn in the 400-500 MeV range, and reduces by ∼50% the stripping loss of the H - beam. This significant improvement will allow a substantial increase in the extracted current above the present routine level of 150μA while maintaining the same levels of residual radioactivity. The system is completed and being commissioned. A description of the design and commissioning procedures is presented, and results of beam tests given. (Author) 7 refs., 5 figs

  20. On Estimating Quantiles Using Auxiliary Information

    Directory of Open Access Journals (Sweden)

    Berger Yves G.

    2015-03-01

    Full Text Available We propose a transformation-based approach for estimating quantiles using auxiliary information. The proposed estimators can be easily implemented using a regression estimator. We show that the proposed estimators are consistent and asymptotically unbiased. The main advantage of the proposed estimators is their simplicity. Despite the fact the proposed estimators are not necessarily more efficient than their competitors, they offer a good compromise between accuracy and simplicity. They can be used under single and multistage sampling designs with unequal selection probabilities. A simulation study supports our finding and shows that the proposed estimators are robust and of an acceptable accuracy compared to alternative estimators, which can be more computationally intensive.

  1. Cooling system for auxiliary reactor component

    International Nuclear Information System (INIS)

    Fujihira, Tomoko.

    1991-01-01

    A cooling system for auxiliary reactor components comprises three systems, that is, two systems of reactor component cooling water systems (RCCW systems) and a high pressure component cooling water system (HPCCW system). Connecting pipelines having partition valves are intervened each in a cooling water supply pipeline to an emmergency component of each of the RCCW systems, a cooling water return pipeline from the emmergency component of each of the RCCW systems, a cooling water supply pipeline to each of the emmergency components of one of the RCCW system and the HPCCW system and a cooling water return pipeline from each of the emmergency components of one of the RCCW system and the HPCCW system. With such constitution, cooling water can be supplied also to the emmergency components in the stand-by system upon periodical inspection or ISI, thereby enabling to improve the backup performance of the emmergency cooling system. (I.N.)

  2. Energic, Exergic, Exergo‐economic investigation and optimization of auxiliary cooling system (ACS equipped with compression refrigerating system (CRS

    Directory of Open Access Journals (Sweden)

    Omid Karimi Sadaghiyani

    2017-09-01

    Full Text Available Heller main cooling tower as air-cooled heat exchanger is used in the combined cycle power plants (CCPP to reduce the temperature of condenser. In extreme summer heat, the efficiency of the cooling tower is reduced and it lessens performance of Steam Turbine Generation (STG unit of Combined Cycle Power Plant (CCPP. Thus, the auxiliary cooling system (ACS is equipped with compression refrigerating system (CRS. This auxiliary system is linked with the Heller main cooling tower and improves the performance of power plant. In other words, this auxiliary system increases the generated power of STG unit of CCPP by decreasing the temperature of returning water from cooling tower Therefore, in the first step, the mentioned auxiliary cooling system (ACS as a heat exchanger and compression refrigerating system (CRS have been designed via ASPEN HTFS and EES code respectively. In order to validate their results, these two systems have been built and theirs experimentally obtained data have been compared with ASPEN and EES results. There are good agreements between results. After that, exergic and exergo-economic analysis of designed systems have been carried out. Finally, the compression refrigerating system (CRS has been optimized via Genetic Algorithm (GA. Increasing in exergy efficiency (ε from 14.23% up to 36.12% and decreasing the total cost rate (ĊSystem from 378.2 ($/h to 308.2 ($/h are as results of multi-objective optimization.

  3. Analysis of design of auxiliary system of Booshehr Nuclear Power Plant

    International Nuclear Information System (INIS)

    Naseh Hasanzadeh, M.

    1999-01-01

    Power plant's internal auxiliary system has an important role in its safety operation. Because of the decay heat and safety aspects in the nuclear power plants, this role is more important. In this thesis, operation of the nuclear power plant with PWR reactor is studied and deferent nuclear systems described. In the next section all electrical loads in the Booshehr Nuclear Power Plant identified and feeding methods of each load is determined. by use of the single line diagram of the internal auxiliary system, the nominal rating of all electrical devices as transformers, inverters, Ups, diesel generators and etc. is determined. In the following, short circuit calculations performed and by above conclusion, rating values of circuit breakers is determined. At last the starting problems of electrical motors is studied and the results of motor's behavior at starting moment is discussed

  4. Installation package for a domestic solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    The installation of two prototype solar heating and hot water systems is described. The systems consists of the following subsystems: solar collector, storage, control, transport, and auxiliary energy.

  5. Major factors in critical equipment reliability - Auxiliary systems; The development of an auxiliary system

    International Nuclear Information System (INIS)

    Forsthoffer, W.E.

    1992-01-01

    In this article, the author details the development of an actual auxiliary system in order to fully understand the function of each major component and how it contributes to the total operation and reliability of the system. Only after the function of an auxiliary system is thoroughly understood, can one proceed to discuss specifications, design audits, testing, operation and preventive maintenance. The application selected will be to develop a pressurized lubrication and steam turbine control oil system for the critical equipment unit. This example was selected since many readers will be familiar with this type and because it provides a good foundation towards understanding fluid sealing systems. In the exercise that follow, he will define the system requirements and determine the system parameters. This information will then be used for component sizing

  6. Energy consumption of auxiliary systems of electric cars

    Directory of Open Access Journals (Sweden)

    Evtimov Ivan

    2017-01-01

    Full Text Available The paper analyzes the power demand of the auxiliary systems of electric cars. On the basis of existing electric cars an analysis of energy consumption of different auxiliary systems is done. As a result possibilities for rational use of these systems have been proposed, which can increase the mileage per one charge of the battery.

  7. 14 CFR 25.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 25.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1142 Auxiliary power unit controls. Means must be provided on the flight deck for starting...

  8. 14 CFR 23.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 23.1142... Powerplant Controls and Accessories § 23.1142 Auxiliary power unit controls. Means must be provided on the... power unit. [Doc. No. 26344, 58 FR 18974, Apr. 9, 1993] ...

  9. 14 CFR 29.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 29.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 29.1142 Auxiliary power unit controls. Means must be provided on the flight deck for starting...

  10. Optimization of feed water control for auxiliary boiler

    International Nuclear Information System (INIS)

    Li Lingmao

    2004-01-01

    This paper described the feed water control system of the auxiliary boiler steam drum in Qinshan Phase III Nuclear Power Plant, analyzed the deficiency of the original configuration, and proposed the optimized configuration. The optimized feed water control system can ensure the stable and safe operation of the auxiliary boiler, and the normal operation of the users. (author)

  11. Dedicated auxiliary power units for Hybrid Electric Vehicles

    NARCIS (Netherlands)

    Mourad, S.; Weijer, C.J.T. van de

    1998-01-01

    The use of a dedicated auxiliary power unit is essential to utilize the potential that hybrid vehicles offer for efficient and ultra-clean transportation. An example of a hybrid project at the TNO Road-Vehicles Research Institute shows the development and the results of a dedicated auxiliary power

  12. The Range of Gapping and the Status of Auxiliaries.

    Science.gov (United States)

    Warner, A. R.

    Full verbs and auxiliaries are subject to gapping. In the simplest cases, this construction type involves apparent ellipsis within one or more clausal conjuncts under identity with the finite verb or auxiliary of a preceding conjunct. It has often been suggested that the apparent ellipsis must involve at least a verb. Some researchers see in the…

  13. Seismic qualification of PWR plant auxiliary feedwater systems

    International Nuclear Information System (INIS)

    Lu, S.C.; Tsai, N.C.

    1983-08-01

    The NRC Standard Review Plan specifies that the auxiliary feedwater (AFW) system of a pressurized water reactor (PWR) is a safeguard system that functions in the event of a Safe Shutdown Earthquake (SSE) to remove the decay heat via the steam generator. Only recently licensed PWR plants have an AFW system designed to the current Standard Review Plan specifications. The NRC devised the Multiplant Action Plan C-14 in order to make a survey of the seismic capability of the AFW systems of operating PWR plants. The purpose of this survey is to enable the NRC to make decisions regarding the need of requiring the licensees to upgrade the AFW systems to an SSE level of seismic capability. To implement the first phase of the C-14 plan, the NRC issued a Generic Letter (GL) 81-14 to all operating PWR licensees requesting information on the seismic capability of their AFW systems. This report summarizes Lawrence Livermore National Laboratory's efforts to assist the NRC in evaluating the status of seismic qualification of the AFW systems in 40 PWR plants, by reviewing the licensees' responses to GL 81-14

  14. Simulation of a passive auxiliary feedwater system with TRACE5

    Energy Technology Data Exchange (ETDEWEB)

    Lorduy, María; Gallardo, Sergio; Verdú, Gumersindo, E-mail: maloral@upv.es, E-mail: sergalbe@iqn.upv.es, E-mail: gverdu@iqn.upv.es [Instituto Universitario de Seguridad Industrial, Radiofísica y Medioambiental (ISIRYM), València (Spain)

    2017-07-01

    The study of the nuclear power plant accidents occurred in recent decades, as well as the probabilistic risk assessment carried out for this type of facility, present human error as one of the main contingency factors. For this reason, the design and development of generation III, III+ and IV reactors, which include inherent and passive safety systems, have been promoted. In this work, a TRACE5 model of ATLAS (Advanced Thermal- Hydraulic Test Loop for Accident Simulation) is used to reproduce an accidental scenario consisting in a prolonged Station BlackOut (SBO). In particular, the A1.2 test of the OECD-ATLAS project is analyzed, whose purpose is to study the primary system cooling by means of the water supply to one of the steam generators from a Passive Auxiliary Feedwater System (PAFS). This safety feature prevents the loss of secondary system inventory by means of the steam condensation and its recirculation. Thus, the conservation of a heat sink allows the natural circulation flow rate until restoring stable conditions. For the reproduction of the test, an ATLAS model has been adapted to the experiment conditions, and a PAFS has been incorporated. >From the simulation test results, the main thermal-hydraulic variables (pressure, flow rates, collapsed water level and temperature) are analyzed in the different circuits, contrasting them with experimental data series. As a conclusion, the work shows the TRACE5 code capability to correctly simulate the behavior of a passive feedwater system. (author)

  15. Radiofrequency launchers for plasma heating and current drive. Report on the IAEA Technical Committee Meeting, held at Naka-machi, Ibaraki-ken, Japan, 10-12 November 1993

    International Nuclear Information System (INIS)

    Kimura, H.; Imai, T.; Yamamoto, T.

    1995-01-01

    The objective of the meeting was to review the present status of the plasma and RF launcher interaction for plasma heating and current drive in various frequency regimes (ion cyclotron to electron cyclotron) and to discuss a possible technical solution for the RF launchers to be installed on large fusion machines. The 23 papers presented during the meeting can be found in the published proceedings. This report of the meeting includes the various contributions presented at the meeting in summary fashion, describing the status of the heating and current drive experiments and the technologies of launching systems with different frequencies, innovative ideas for launching systems for next stage large fusion devices and new RF systems under development. 23 refs, 3 tabs

  16. [Radiofrequency ablation of hepatocellular carcinoma].

    Science.gov (United States)

    Widmann, Gerlig; Schullian, Peter; Bale, Reto

    2013-03-01

    Percutaneous radiofrequency ablation (RFA) is well established in the treatment of hepatocellular carcinoma (HCC). Due to its curative potential, it is the method of choice for non resectable BCLC (Barcelona Liver Clinic) 0 and A. RFA challenges surgical resection for small HCC and is the method of choice in bridging for transplantation and recurrence after resection or transplantation. The technical feasibility of RFA depends on the size and location of the HCC and the availability of ablation techniques (one needle techniques, multi-needle techniques). More recently, stereotactic multi-needle techniques with 3D trajectory planning and guided needle placement substantially improve the spectrum of treatable lesions including large volume tumors. Treatment success depends on the realization of ablations with large intentional margins of tumor free tissue (A0 ablation in analogy to R0 resection), which has to be documented by fusion of post- with pre-ablation images, and confirmed during follow-up imaging.

  17. Low power radiofrequency electromagnetic radiation for the treatment of pain due to osteoarthritis of the knee

    Directory of Open Access Journals (Sweden)

    U. Santosuosso

    2011-09-01

    Full Text Available Different techniques have been used in some rheumatic diseases to induce a therapeutic effect by heating deep tissues. These techniques are commonly known as ‘thermotherapy’ (1-4. It should be observed that adequate heating of deep tissues cannot be obtained by conduction or convection of heat because the skin and subcutaneous fat are good thermal insulators and because heating is reduced by blood flow in superficial vessels. Heating of deep tissues can instead be obtained by conversion of other forms of energy into heat. Conversion heat is generated by different types of radiations absorbed by deep tissues: when radiation interacts with tissues, some energy is converted into heat. High power radiofrequency electromagnetic radiation (RF, which produces strong thermal energy, has been widely applied in medicine for ablative procedures (5-7.

  18. Sea water take-up facility for cooling reactor auxiliary

    International Nuclear Information System (INIS)

    Numata, Noriko; Mizutani, Akira; Hirako, Shizuka; Uchiyama, Yuichi; Oda, Atsushi.

    1997-01-01

    The present invention provides an improvement of a cooling sea water take-up facility for cooling auxiliary equipments of nuclear power plant. Namely, an existent sea water take-up facility for cooling reactor auxiliary equipments has at least two circulation water systems and three independent sea water systems for cooling reactor auxiliary equipments. In this case, a communication water channel is disposed, which connects the three independent sea water systems for cooling reactor auxiliary equipments mutually by an opening/closing operation of a flow channel partitioning device. With such a constitution, even when any combination of two systems among the three circulation water systems is in inspection at the same time, one system for cooling the reactor auxiliary equipments can be kept operated, and one system is kept in a stand-by state by the communication water channel upon periodical inspection of water take-up facility for cooling the auxiliary equipments. As a result, the sea water take-up facility for cooling auxiliary equipments of the present invention have operation efficiency higher than that of a conventional case while keeping the function and safety at the same level as in the conventional case. (I.S.)

  19. Aging assessment of auxiliary feedwater pumps

    International Nuclear Information System (INIS)

    Greenstreet, W.L.

    1987-01-01

    ORNL is conducting aging assessments of auxiliary feedwater pumps to provide recommendations for monitoring and assessing the severity of time-dependent degradation as well as to recommend maintenance and replacement practices. Cornerstones of these activities are the identification of failure modes and causes and ranking of causes. Failure modes and causes of interest are those due to aging and service wear. Design details, functional requirements, and operating experience data were used to identify failure modes and causes and to rank the latter. Based on this input, potentially useful inspection, surveillance, and condition monitoring methods that are currently available for use or in the developmental stage were examined and recommendations made. The methods selected are listed and discussed in terms of use and information to be obtained. Relationships between inspection, surveillance, and monitoring and maintenance practices entered prominently into maintenance recommendations. These recommendations, therefore, embrace predictive as well as corrective and preventative maintenance practices. The recommendations are described, inspection details are discussed, and periodic inspection and maintenance interval guidelines are given. Surveillance testing at low-flow conditions is also discussed. It is shown that this type of testing can lead to accelerated aging

  20. Ignited tokamak devices with ohmic-heating dominated startup

    International Nuclear Information System (INIS)

    Cohn, D.R.; Bromberg, L.; Jassby, D.L.

    1986-01-01

    Startup of tokamaks such that the auxiliary heating power is significantly less than the ohmic heating power at all times during heating to ignition can be referred to as ''Ohmic-heating dominated startup.'' Operation in this mode could increase the certainty of heating to ignition since energy confinement during startup may be described by present scaling laws for ohmic heating. It could also reduce substantially the auxiliary heating power (the required power may be quite large for auxiliary-heating dominated startup). These advantages might be realized without the potentially demanding requirements for pure ohmic heating to ignition. In this paper the authors discuss the requirements for ohmic-heating dominated startup and present illustrative design parameters for compact experiment ignition devices that use high performance copper magnets

  1. Comparison of QuadrapolarTM radiofrequency lesions produced by standard versus modified technique: an experimental model

    Directory of Open Access Journals (Sweden)

    Safakish R

    2017-06-01

    Full Text Available Ramin Safakish Allevio Pain Management Clinic, Toronto, ON, Canada Abstract: Lower back pain (LBP is a global public health issue and is associated with substantial financial costs and loss of quality of life. Over the years, different literature has provided different statistics regarding the causes of the back pain. The following statistic is the closest estimation regarding our patient population. The sacroiliac (SI joint pain is responsible for LBP in 18%–30% of individuals with LBP. Quadrapolar™ radiofrequency ablation, which involves ablation of the nerves of the SI joint using heat, is a commonly used treatment for SI joint pain. However, the standard Quadrapolar radiofrequency procedure is not always effective at ablating all the sensory nerves that cause the pain in the SI joint. One of the major limitations of the standard Quadrapolar radiofrequency procedure is that it produces small lesions of ~4 mm in diameter. Smaller lesions increase the likelihood of failure to ablate all nociceptive input. In this study, we compare the standard Quadrapolar radiofrequency ablation technique to a modified Quadrapolar ablation technique that has produced improved patient outcomes in our clinic. The methodology of the two techniques are compared. In addition, we compare results from an experimental model comparing the lesion sizes produced by the two techniques. Taken together, the findings from this study suggest that the modified Quadrapolar technique provides longer lasting relief for the back pain that is caused by SI joint dysfunction. A randomized controlled clinical trial is the next step required to quantify the difference in symptom relief and quality of life produced by the two techniques. Keywords: lower back pain, radiofrequency ablation, sacroiliac joint, Quadrapolar radiofrequency ablation

  2. Design, Testing and Modeling of the Direct Reactor Auxiliary Cooling System for AHTRs

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Quiping [The Ohio State Univ., Columbus, OH (United States); Sun, Xiaodong [The Ohio State Univ., Columbus, OH (United States); Chtistensen, Richard [The Ohio State Univ., Columbus, OH (United States); Blue, Thomas [The Ohio State Univ., Columbus, OH (United States); Yoder, Graydon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-05-08

    The principal objective of this research is to test and model the heat transfer performance and reliability of the Direct Reactor Auxiliary Cooling System (DRACS) for AHTRs. In addition, component testing of fluidic diodes is to be performed to examine the performance and viability of several existing fluidic diode designs. An extensive database related to the thermal performance of the heat exchangers involved will be obtained, which will be used to benchmark a computer code for the DRACS design and to evaluate and improve, if needed, existing heat transfer models of interest. The database will also be valuable for assessing the viability of the DRACS concept and benchmarking any related computer codes in the future. The experience of making a liquid fluoride salt test facility available, with lessons learned, will greatly benefit the development of the Fluoride Salt-cooled High-temperature Reactor (FHR) and eventually the AHTR programs.

  3. Design, Testing and Modeling of the Direct Reactor Auxiliary Cooling System for AHTRs

    International Nuclear Information System (INIS)

    Lv, Quiping; Sun, Xiaodong; Chtistensen, Richard; Blue, Thomas; Yoder, Graydon; Wilson, Dane

    2015-01-01

    The principal objective of this research is to test and model the heat transfer performance and reliability of the Direct Reactor Auxiliary Cooling System (DRACS) for AHTRs. In addition, component testing of fluidic diodes is to be performed to examine the performance and viability of several existing fluidic diode designs. An extensive database related to the thermal performance of the heat exchangers involved will be obtained, which will be used to benchmark a computer code for the DRACS design and to evaluate and improve, if needed, existing heat transfer models of interest. The database will also be valuable for assessing the viability of the DRACS concept and benchmarking any related computer codes in the future. The experience of making a liquid fluoride salt test facility available, with lessons learned, will greatly benefit the development of the Fluoride Salt-cooled High-temperature Reactor (FHR) and eventually the AHTR programs.

  4. Trace analysis of auxiliary feedwater capacity for Maanshan PWR loss-of-normal-feedwater transient

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Che-Hao; Shih, Chunkuan [National Tsing Hua Univ., Taiwan (China). Inst. of Nuclear Engineering and Science; Wang, Jong-Rong; Lin, Hao-Tzu [Atomic Energy Council, Taiwan (China). Inst. of Nuclear Energy Research

    2013-07-01

    Maanshan nuclear power plant is a Westinghouse PWR of Taiwan Power Company (Taipower, TPC). A few years ago, TPC has made many assessments in order to uprate the power of Maanshan NPP. The assessments include NSSS (Nuclear Steam Supply System) parameters calculation, uncertainty acceptance, integrity of pressure vessel, reliability of auxiliary systems, and transient analyses, etc. Since the Fukushima Daiichi accident happened, it is necessary to consider transients with multiple-failure. Base on the analysis, we further study the auxiliary feedwater capability for Loss-of-Normal-Feedwater (LONF) transient. LONF is the limiting transient of non-turbine trip initiated event for ATWS (Anticipated Transient Without Scram) which results in a reduction in capability of the secondary system to remove the heat generated in the reactor core. If the turbine fails to trip immediately, the secondary water inventory will decrease significantly before the actuation of auxiliary feedwater (AFW) system. The heat removal from the primary side decreases, and this leads to increases of primary coolant temperature and pressure. The water level of pressurizer also increases subsequently. The heat removal through the relief valves and the auxiliary feedwater is not sufficient to fully cope with the heat generation from primary side. The pressurizer will be filled with water finally, and the RCS pressure might rise above the set point of relief valves for water discharge. RCS pressure depends on steam generator inventory, primary coolant temperature, negative reactivity feedback, and core power, etc. The RCS pressure may reach its peak after core power reduction. According to ASME Code Level C service limit criteria, the Reactor Coolant System (RCS) pressure must be under 22.06 MPa. The USNRC is developing an advanced thermal hydraulic code named TRACE for nuclear power plant safety analysis. The development of TRACE is based on TRAC and integrating with RELAP5 and other programs. SNAP

  5. Trace analysis of auxiliary feedwater capacity for Maanshan PWR loss-of-normal-feedwater transient

    International Nuclear Information System (INIS)

    Chen, Che-Hao; Shih, Chunkuan; Wang, Jong-Rong; Lin, Hao-Tzu

    2013-01-01

    Maanshan nuclear power plant is a Westinghouse PWR of Taiwan Power Company (Taipower, TPC). A few years ago, TPC has made many assessments in order to uprate the power of Maanshan NPP. The assessments include NSSS (Nuclear Steam Supply System) parameters calculation, uncertainty acceptance, integrity of pressure vessel, reliability of auxiliary systems, and transient analyses, etc. Since the Fukushima Daiichi accident happened, it is necessary to consider transients with multiple-failure. Base on the analysis, we further study the auxiliary feedwater capability for Loss-of-Normal-Feedwater (LONF) transient. LONF is the limiting transient of non-turbine trip initiated event for ATWS (Anticipated Transient Without Scram) which results in a reduction in capability of the secondary system to remove the heat generated in the reactor core. If the turbine fails to trip immediately, the secondary water inventory will decrease significantly before the actuation of auxiliary feedwater (AFW) system. The heat removal from the primary side decreases, and this leads to increases of primary coolant temperature and pressure. The water level of pressurizer also increases subsequently. The heat removal through the relief valves and the auxiliary feedwater is not sufficient to fully cope with the heat generation from primary side. The pressurizer will be filled with water finally, and the RCS pressure might rise above the set point of relief valves for water discharge. RCS pressure depends on steam generator inventory, primary coolant temperature, negative reactivity feedback, and core power, etc. The RCS pressure may reach its peak after core power reduction. According to ASME Code Level C service limit criteria, the Reactor Coolant System (RCS) pressure must be under 22.06 MPa. The USNRC is developing an advanced thermal hydraulic code named TRACE for nuclear power plant safety analysis. The development of TRACE is based on TRAC and integrating with RELAP5 and other programs. SNAP

  6. 46 CFR 182.620 - Auxiliary means of steering.

    Science.gov (United States)

    2010-10-01

    ... TONS) MACHINERY INSTALLATION Steering Systems § 182.620 Auxiliary means of steering. (a) Except as... personnel hazards during normal or heavy weather operation. (b) A suitable hand tiller may be acceptable as...

  7. Effects of Auxiliary-Source Connection in Multichip Power Module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Wang, Xiongfei

    2017-01-01

    the power loop and the gate loop like how the Kelvin-source connection does, owing to their involvement in the loop of the power source current. Three effects of the auxiliary-source connections are then analyzed, which are 1) the common source stray inductance reduction, 2) the transient drain......Auxiliary-source bond wires and connections are widely used in power modules with paralleled MOSFETs or IGBTs. This paper investigates the operation mechanism of the auxiliary-source connections in multichip power modules. It reveals that the auxiliary-source connections cannot fully decouple......-source current imbalance mitigation, and 3) the influence on the steady-state current distribution. Lastly, simulations and experimental results validate the theoretical analysis....

  8. New set of auxiliary fields for supergravity theories

    International Nuclear Information System (INIS)

    Oliveira Rivelles, V. de.

    1983-02-01

    A brief introduction on supersymmetry is given. The problems with the obtainment of the auxiliary fields in supergravity theories are discussed, after a short presentation of the supersymmetry algebra representations. (L.C.) [pt

  9. The installation of helium auxiliary systems in HTGR

    International Nuclear Information System (INIS)

    Qin Zhenya; Fu Xiaodong

    1993-01-01

    The inert gas Helium was chosen as reactor coolant in high temperature gas coolant reactor, therefore a set of Special and uncomplex helium auxiliary systems will be installed, the safe operation of HTR-10 can be safeguarded. It does not effect the inherent safety of HTR-10 MW if any one of all those systems were damaged during operation condition. This article introduces the design function and the system principle of all helium auxiliary systems to be installed in HTR-10. Those systems include: helium purification and its regeneration system, helium supply and storage system, pressure control and release system of primary system, dump system for helium auxiliary system and fuel handling, gaseous waste storage system, water extraction system for helium auxiliary systems and evacuation system for primary system

  10. Auxiliary fields for super Yang-Mills from division algebras

    CERN Document Server

    Evans, Jonathan M.

    1994-01-01

    Division algebras are used to explain the existence and symmetries of various sets of auxiliary fields for super Yang-Mills in dimensions d=3,4,6,10. (Contribution to G\\"ursey Memorial Conference I: Strings and Symmetries)

  11. Parallel Auxiliary Space AMG Solver for $H(div)$ Problems

    Energy Technology Data Exchange (ETDEWEB)

    Kolev, Tzanio V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-12-18

    We present a family of scalable preconditioners for matrices arising in the discretization of $H(div)$ problems using the lowest order Raviart--Thomas finite elements. Our approach belongs to the class of “auxiliary space''--based methods and requires only the finite element stiffness matrix plus some minimal additional discretization information about the topology and orientation of mesh entities. Also, we provide a detailed algebraic description of the theory, parallel implementation, and different variants of this parallel auxiliary space divergence solver (ADS) and discuss its relations to the Hiptmair--Xu (HX) auxiliary space decomposition of $H(div)$ [SIAM J. Numer. Anal., 45 (2007), pp. 2483--2509] and to the auxiliary space Maxwell solver AMS [J. Comput. Math., 27 (2009), pp. 604--623]. Finally, an extensive set of numerical experiments demonstrates the robustness and scalability of our implementation on large-scale $H(div)$ problems with large jumps in the material coefficients.

  12. Radiofrequency cold plasma nitrided carbon steel: Microstructural and micromechanical characterizations

    International Nuclear Information System (INIS)

    Bouanis, F.Z.; Bentiss, F.; Bellayer, S.; Vogt, J.B.; Jama, C.

    2011-01-01

    Highlights: → C38 carbon steel samples were plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge. → RF plasma treatment enables nitriding for non-heated substrates. → The morphological and chemical analyses show the formation of a uniform thickness on the surface of the nitrided C38 steel. → Nitrogen plasma active species diffuse into the samples and lead to the formation of Fe x N. → The increase in microhardness values for nitrided samples with plasma processing time is interpreted by the formation of a thicker nitrided layer on the steel surface. - Abstract: In this work, C38 carbon steel was plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge on non-heated substrates. General characterizations were performed to compare the chemical compositions, the microstructures and hardness of the untreated and plasma treated surfaces. The plasma nitriding was carried out on non-heated substrates at a pressure of 16.8 Pa, using N 2 gas. Surface characterizations before and after N 2 plasma treatment were performed by means of the electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Vickers microhardness measurements. The morphological and chemical analysis showed the formation of a uniform structure on the surface of the nitrided sample with enrichment in nitrogen when compared to untreated sample. The thickness of the nitride layer formed depends on the treatment time duration and is approximately 14 μm for 10 h of plasma treatment. XPS was employed to obtain chemical-state information of the plasma nitrided steel surfaces. The micromechanical results show that the surface microhardness increases as the plasma-processing time increases to reach, 1487 HV 0.005 at a plasma processing time of 8 h.

  13. Radiofrequency cold plasma nitrided carbon steel: Microstructural and micromechanical characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Bouanis, F.Z. [Universite Lille Nord de France, F-59000 Lille (France); Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F. [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Bellayer, S.; Vogt, J.B. [Universite Lille Nord de France, F-59000 Lille (France); Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Jama, C., E-mail: charafeddine.jama@ensc-lille.fr [Universite Lille Nord de France, F-59000 Lille (France); Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France)

    2011-05-16

    Highlights: {yields} C38 carbon steel samples were plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge. {yields} RF plasma treatment enables nitriding for non-heated substrates. {yields} The morphological and chemical analyses show the formation of a uniform thickness on the surface of the nitrided C38 steel. {yields} Nitrogen plasma active species diffuse into the samples and lead to the formation of Fe{sub x}N. {yields} The increase in microhardness values for nitrided samples with plasma processing time is interpreted by the formation of a thicker nitrided layer on the steel surface. - Abstract: In this work, C38 carbon steel was plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge on non-heated substrates. General characterizations were performed to compare the chemical compositions, the microstructures and hardness of the untreated and plasma treated surfaces. The plasma nitriding was carried out on non-heated substrates at a pressure of 16.8 Pa, using N{sub 2} gas. Surface characterizations before and after N{sub 2} plasma treatment were performed by means of the electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Vickers microhardness measurements. The morphological and chemical analysis showed the formation of a uniform structure on the surface of the nitrided sample with enrichment in nitrogen when compared to untreated sample. The thickness of the nitride layer formed depends on the treatment time duration and is approximately 14 {mu}m for 10 h of plasma treatment. XPS was employed to obtain chemical-state information of the plasma nitrided steel surfaces. The micromechanical results show that the surface microhardness increases as the plasma-processing time increases to reach, 1487 HV{sub 0.005} at a plasma processing time of 8 h.

  14. Comparison of Radiofrequency and Electrocautery With Conventional Scalpel Incisions.

    Science.gov (United States)

    Hasar, Zafer Burak; Ozmeric, Nurdan; Ozdemir, Burcu; Gökmenoğlu, Ceren; Baris, Emre; Altan, Gökçen; Kahraman, Sevil

    2016-11-01

    The disadvantages of conventional scalpels, including insufficient control of bleeding, prompted us to search for new alternative methods such as electrosurgery and radiosurgery. In this study, the conventional scalpel was compared with radiosurgery and electrosurgery for wound healing with assessment of lateral heat production, inflammation, and instrument performance. Incisions were made in the palatal mucosa of 42 Wistar rats using a scalpel, electrocautery instrument, or radiofrequency instrument. Postoperative hemostasis, tissue coagulation, and tissue sticking were measured, and pain evaluation through weight loss was recorded. Gingival biopsy specimens from the surgical area were obtained at the time of surgery and 2, 4, 7, and 14 days postoperatively and were evaluated immunohistochemically for inducible nitric oxide synthase and heat shock protein 70. Kruskal-Wallis, 1-way analysis of variance, and Mann-Whitney U tests were used for statistical evaluation. The rats in the electrosurgery and radiosurgery groups had aggressively greater weight loss when compared with the scalpel group in the first 7 days. Hemostasis was better in the electrocautery group, tissue coagulation was greater in the radiofrequency group (P < .001), and tissue sticking was lesser in the scalpel group (P < .001) compared with the other groups. Inducible nitric oxide synthase expression and heat shock protein 70 expression were similar in all 3 groups. Electrosurgery performed better regarding hemostasis, whereas a scalpel was superior in terms of tissue sticking and tissue coagulation. Radiosurgery was superior regarding hemostasis when compared with a conventional scalpel, but it was not as successful as electrosurgery. Copyright © 2016. Published by Elsevier Inc.

  15. An auxiliary differential equation FDTD method for anisotropic magnetized plasmas

    International Nuclear Information System (INIS)

    Liu Shaobin; Mo Jinjun; Yuan Naichang

    2004-01-01

    An auxiliary differential equation finite-difference time-domain (ADE-FDTD) methodology for anisotropic magnetized plasmas is derived. The method is based on a difference approximation of the auxiliary differential equation. A comparison with the JEC method is included. The CPU time saving by several times and accuracy of the method are confirmed by computing the reflection and transmission through a magnetized plasma layer with the direction of propagation parallel to the direction of the biasing field

  16. Operating experiences and degradation detection for auxiliary feedwater systems

    International Nuclear Information System (INIS)

    Casada, D.; Farmer, W.S.

    1992-01-01

    A study of Pressurized Water Reactor Auxiliary Feedwater (AFW) Systems has been conducted by Oak Ridge National Laboratory (ORNL) under the auspices of the Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. The results of the study are documented in NUREG/CR-5404, Vol. 1, Auxiliary Feedwater System Aging Study. The study reviewed historical failure experience and current monitoring practices for the AFW System. This paper provides an overview of the study approach and results

  17. New resonant circuits for the ISOLTRAP radiofrequency quadrupole trap

    CERN Document Server

    SENECAL, Pierre

    2015-01-01

    This report describes my work during my Summer Student Program. My main project was building and testing a resonance-circuit box for a radio-frequency power supply used with the radio-frequency cooler and buncher.

  18. Radiofrequency ablation of pulmonary tumors

    Energy Technology Data Exchange (ETDEWEB)

    Crocetti, Laura, E-mail: l.crocetti@med.unipi.i [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy); Lencioni, Riccardo [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy)

    2010-07-15

    The development of image-guided percutaneous techniques for local tumor ablation has been one of the major advances in the treatment of solid tumors. Among these methods, radiofrequency (RF) ablation is currently established as the primary ablative modality at most institutions. RF ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma when liver transplantation or surgical resection are not suitable options and is considered as a viable alternate to surgery for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer. Recently, RF ablation has been demonstrated to be a safe and valuable treatment option for patients with unresectable or medically inoperable lung malignancies. Resection should remain the standard therapy for non-small cell lung cancer (NSCLC) but RF ablation may be better than conventional external-beam radiation for the treatment of the high-risk individual with NSCLC. Initial favourable outcomes encourage combining radiotherapy and RF ablation, especially for treating larger tumors. In the setting of colorectal cancer lung metastases, survival rates provided by RF ablation in selected patients, are substantially higher than those obtained with any chemotherapy regimens and provide indirect evidence that RF ablation therapy improves survival in patients with limited lung metastatic disease.

  19. Dielectric-filled radiofrequency linacs

    Energy Technology Data Exchange (ETDEWEB)

    Faehl, R J; Keinigs, R K; Pogue, E W [Los Alamos National Lab., NM (United States)

    1997-12-31

    High current, high brightness electron beam accelerators promise to open up dramatic new applications. Linear induction accelerators are currently viewed as the appropriate technology for these applications. A concept by Humphries and Hwang may permit radiofrequency accelerators to fulfill the same functions with greater simplicity and enhanced flexibility. This concept involves the replacement of vacuum rf cavities with dielectric filled ones. Simple analysis indicates that the resonant frequencies are reduced by a factor of ({epsilon}{sub 0}/{epsilon}){sup 1/2} while the stored energy is increased by {epsilon}/{epsilon}{sub 0}. For a high dielectric constant like water, this factor can approach 80. A series of numerical calculations of simple pill-box cavities was performed. Eigenfunctions and resonant frequencies for a full system configuration, including dielectric material, vacuum beamline, and a ceramic window separating the two have been computed. These calculations are compared with the results of a small experimental cavity which have been constructed and operated. Low power tests show excellent agreement. (author). 4 figs., 8 refs.

  20. The radiofrequency magnetic dipole discharge

    Energy Technology Data Exchange (ETDEWEB)

    Martines, E., E-mail: emilio.martines@igi.cnr.it; Zuin, M.; Cavazzana, R.; Fassina, A.; Spolaore, M. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Marcante, M. [Dipartimento di Fisica, Università di Trento, via Sommarive 14, 38123 Povo, TN (Italy); TIFPA, Trento Institute for Fundamental Physics and Applications INFN, 38123 Trento (Italy)

    2016-05-15

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3–4 eV and higher in the cathode proximity. Plasma densities of the order of 10{sup 16 }m{sup −3} have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  1. The radiofrequency magnetic dipole discharge

    Science.gov (United States)

    Martines, E.; Zuin, M.; Marcante, M.; Cavazzana, R.; Fassina, A.; Spolaore, M.

    2016-05-01

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3-4 eV and higher in the cathode proximity. Plasma densities of the order of 1016 m-3 have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  2. A survey on monopolar radiofrequency treatment.

    Science.gov (United States)

    Suh, Dong Hye; Hong, Eun Sun; Kim, Hyun Joo; Lee, Sang Jun; Kim, Hei Sung

    2017-09-01

    This questionnaire-based study was aimed to measure the level of appreciation, awareness of the special tips, and practice patterns of monopolar radiofrequency among Korean dermatologists practicing a specific monopolar radiofrequency device (Thermage® Inc., Hayward, CA). A total of 82 surveys were analyzed to show that the majority of participants (78.8%) were highly satisfied with the outcomes of monopolar radiofrequency treatment. All respondents were aware of the Eye Tip 0.25 cm 2 , and the majority knew the difference between the Face tip (blue) and the Total tip (orange). Most (86.3%) agreed to the statement that 900 shots were appropriate for facial tightening in those between the ages of 35 and 65 years. 66.2% of participants reported to have perform monopolar radiofrequency to extra-facial sites within the past year. As for the tips, the Total tip was most popular for all body sties and the Big tip was favored for the abdomen, thighs and buttock. We hope our data allow dermatologists to better utilize monopolar radiofrequency. © 2017 Wiley Periodicals, Inc.

  3. Three-dimensional model of a liquid-cooled, low energy booster, radio-frequency cavity tuner at the superconducting super collider

    International Nuclear Information System (INIS)

    Ranganathan, R.; Propp, A.; Campbell, B.; Dao, B.

    1994-01-01

    A three-dimensional computational heat transfer and fluid flow model was developed to analyze a forced-flow, liquid-cooled, low energy booster (LEB), radio-frequency (RF) cavity, tuner concept. The results for a commercial dielectric heat transfer fluid indicated safe temperatures in the ferrite

  4. Non-Invasive Radiofrequency Field Treatment to Produce Hepatic Hyperthermia: Efficacy and Safety in Swine

    OpenAIRE

    ,; ,; ,; ,; ,; ,; ,; ,; ,

    2017-01-01

    The Kanzius non-invasive radio-frequency hyperthermia system (KNiRFH) has been investigated as a treatment option for hepatic hyperthermia cancer therapy. The treatment involves exposing the patient to an external high-power RF (13.56 MHz) electric field, whereby the propagating waves penetrate deep into the tumor causing targeted heating based on differential tissue dielectric properties. However, a comprehensive examination of the Kanzius system alongside any associated toxicities and its a...

  5. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency radiation exposure limits. 1... Procedures Implementing the National Environmental Policy Act of 1969 § 1.1310 Radiofrequency radiation... exposure to radiofrequency (RF) radiation as specified in § 1.1307(b), except in the case of portable...

  6. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion generator. 882.4400 Section... (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4400 Radiofrequency lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

  7. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency electrosurgical cautery apparatus... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency electrosurgical cautery apparatus. (a) Identification. A radiofrequency electrosurgical cautery apparatus is an AC...

  8. Osteoid osteoma of the spine: CT-guided monopolar radiofrequency ablation

    Energy Technology Data Exchange (ETDEWEB)

    Martel, Jose [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain)], E-mail: jmartel@fhalcorcon.es; Bueno, Angel [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain); Nieto-Morales, M Luisa [Servicio de Radiologia, Hospital Universitario de Tenerife (Spain); Ortiz, Eduardo J. [Departamento de Cirugia Ortopedica, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain)

    2009-09-15

    CT-guided percutaneous radiofrequency ablation and laser photocoagulation have become the methods of choice for the treatment of all osteoid osteomas except those in contact with neural structures. We report 10 patients with spinal osteoid osteoma adjacent to the neural elements treated with 12 sessions of CT-guided monopolar radiofrequency ablation. The size range of the lesion was 3-14 mm (mean, 7.5 mm) and the distance between the nidus and the adjacent spinal cord or nerve root was 2-12 mm (mean, 5 mm). No intact cortex between the tumor and the spinal cord or nerve roots constituted an exclusion criterion because of a higher risk of undesirable neurotoxic effects. Patients were under general anesthesia. After location of the lesion, a 11G-bone biopsy was introduced into the nidus. The radiofrequency electrode was inserted through the biopsy needle and heated at 90 deg. C for 4 min. Primary success was obtained in eight patients. At follow-up (mean, 19.5 months; range, 6-24 months), pain persisted in two patients after 2 months. Both of them were re-treated. All patients are currently pain-free and complications were not detected. In our opinion, radiofrequency ablation can also be considered the treatment of choice for spinal osteoid osteoma.

  9. Osteoid osteoma of the spine: CT-guided monopolar radiofrequency ablation

    International Nuclear Information System (INIS)

    Martel, Jose; Bueno, Angel; Nieto-Morales, M Luisa; Ortiz, Eduardo J.

    2009-01-01

    CT-guided percutaneous radiofrequency ablation and laser photocoagulation have become the methods of choice for the treatment of all osteoid osteomas except those in contact with neural structures. We report 10 patients with spinal osteoid osteoma adjacent to the neural elements treated with 12 sessions of CT-guided monopolar radiofrequency ablation. The size range of the lesion was 3-14 mm (mean, 7.5 mm) and the distance between the nidus and the adjacent spinal cord or nerve root was 2-12 mm (mean, 5 mm). No intact cortex between the tumor and the spinal cord or nerve roots constituted an exclusion criterion because of a higher risk of undesirable neurotoxic effects. Patients were under general anesthesia. After location of the lesion, a 11G-bone biopsy was introduced into the nidus. The radiofrequency electrode was inserted through the biopsy needle and heated at 90 deg. C for 4 min. Primary success was obtained in eight patients. At follow-up (mean, 19.5 months; range, 6-24 months), pain persisted in two patients after 2 months. Both of them were re-treated. All patients are currently pain-free and complications were not detected. In our opinion, radiofrequency ablation can also be considered the treatment of choice for spinal osteoid osteoma.

  10. Challenges in Radiofrequency Pasteurization of Shell Eggs: Coagulation Rings.

    Science.gov (United States)

    Lau, Soon Kiat; Thippareddi, Harshavardhan; Jones, David; Negahban, Mehrdad; Subbiah, Jeyamkondan

    2016-10-01

    A total of 50 different configurations of simple radiofrequency (RF) heating at 27.12 MHz of a shell egg were simulated using a finite element model with the purpose of pasteurizing the egg. Temperature-dependent thermal and dielectric properties of the yolk, albumen, and shell were measured, fitted, and introduced into the model. A regression equation that relates the top electrode voltage to the gap between the electrodes and vertical position of the egg was developed. Simulation and experimental results had good agreement in terms of temperature deviation (root mean squared error ranged from 0.35 °C to 0.48 °C) and both results demonstrated the development of a "coagulation ring" around the air cell. The focused heating near the air cell of the egg prevented pasteurization of the egg due to its impact on quality (coagulation). Analysis of the electric field patterns offered a perspective on how nonuniform RF heating could occur in heterogeneous food products. The results can be used to guide development of RF heating for heterogeneous food products and further development of RF pasteurization of eggs. © 2016 Institute of Food Technologists®.

  11. 46 CFR 58.25-10 - Main and auxiliary steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main and auxiliary steering gear. 58.25-10 Section 58.25... AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-10 Main and auxiliary steering gear. (a) Power-operated main and auxiliary steering gear must be separate systems that are independent throughout their...

  12. Numerical simulation of side heating for controlling angular ...

    Indian Academy of Sciences (India)

    In the present study, a 3-D coupled transient thermal analysis model with auxiliary side heating (parallel heating) is developed to control angular distortion. During analysis, parallel heating flames are placed at several locations from weld line in cross direction. A user defined subroutine is used to apply transient heat source ...

  13. 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

  14. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  15. Probabilistic cloning with supplementary information contained in the quantum states of two auxiliary systems

    International Nuclear Information System (INIS)

    Li, Lvjun; Qiu, Daowen

    2007-01-01

    In probabilistic cloning with two auxiliary systems, we consider and compare three different protocols for the success probabilities of cloning. We show that, in certain circumstances, it may increase the success probability to add an auxiliary system to the probabilistic cloning machine having one auxiliary system, but we always can find another cloning machine with one auxiliary system having the same success probability as that with two auxiliary systems

  16. The radiofrequency frontier: a review of radiofrequency and combined radiofrequency pulsed-light technology in aesthetic medicine.

    Science.gov (United States)

    Sadick, Neil; Sorhaindo, Lian

    2005-05-01

    Radiofrequency (RF) and combined RF light source technologies have established themselves as safe and effective treatment modalities for several dermatologic procedures, including skin tightening, hair and leg vein removal, acne scarring, skin rejuvenation, and wrinkle reduction. This article reviews the technology, clinical applications, and recent advances of RF and combined RF light/laser source technologies in aesthetic medicine.

  17. Painless, safe, and efficacious noninvasive skin tightening, body contouring, and cellulite reduction using multisource 3DEEP radiofrequency.

    Science.gov (United States)

    Harth, Yoram

    2015-03-01

    In the last decade, Radiofrequency (RF) energy has proven to be safe and highly efficacious for face and neck skin tightening, body contouring, and cellulite reduction. In contrast to first-generation Monopolar/Bipolar and "X -Polar" RF systems which use one RF generator connected to one or more skin electrodes, multisource radiofrequency devices use six independent RF generators allowing efficient dermal heating to 52-55°C, with no pain or risk of other side effects. In this review, the basic science and clinical results of body contouring and cellulite treatment using multisource radiofrequency system (Endymed PRO, Endymed, Cesarea, Israel) will be discussed and analyzed. © 2015 Wiley Periodicals, Inc.

  18. Standard guidelines for electrosurgery with radiofrequency current

    Directory of Open Access Journals (Sweden)

    Mutalik Sharad

    2009-08-01

    Full Text Available Definition: Radiofrequency (RF induces thermal destruction of the targeted tissue by an electrical current at a frequency of 0.5 MHz (RF. As the electrode tip is not heated, there is minimal thermal damage to the surrounding tissues, producing good esthetic results. Therefore, RF ablation is also known as cold ablation or "coblation." Modality: It has three modes of operation: (a Cut, (b cut and coagulate and (c coagulate. Therefore, it can be used for various purposes like incision, ablation, fulguration, shave excision and coagulation. Because of the coagulation facility, hemostasis can be achieved and operation becomes easier and faster. Indications: It is effective in treating various skin conditions like dermatosis papulosa nigra, warts, molluscum contagiosum, colloid milia, acquired junctional, compound and dermal melanocytic nevi, seborrheic keratosis, skin tags, granuloma pyogenicum, verrucous epidermal nevi, xanthelesma, rhinophyma, superficial basal cell carcinoma and telangiectasia. It can also be used for cosmetic indications such as resurfacing, earlobe repair and blepharoplasty. Anesthesia: The procedure is accomplished either under topical anesthesia eutactic mixture of local anesthetics or local injectable anesthesia, under all aseptic precautions. Procedure: While operating, only the tip of the electrode should come in contact with the tissue. Actual contact of the electrode with the tissue should be very brief in order to prevent excessive damage to the deeper tissues. This can be accomplished by moving the electrode quickly. Complications: Complications are uncommon and mainly occur due to an improper technique. The treating physician should be aware of the contraindications of the procedure as listed in these guidelines. Physician qualification: RF surgery may be performed by a dermatologist who has acquired adequate training during post-graduation or through recognized fellowships and workshops dedicated to RF surgery. He

  19. Safety of lumbar spine radiofrequency procedures in the presence of posterior pedicle screws: technical report of a cadaver study.

    Science.gov (United States)

    Gazelka, Halena M; Welch, Tasha L; Nassr, Ahmad; Lamer, Tim J

    2015-05-01

    To determine whether the thermal energy associated with lumbar spine radiofrequency neurotomy (RFN) performed near titanium and stainless steel pedicle screws is conducted to the pedicle screws or adjacent tissues, or both, thus introducing potential for thermal damage to those tissues. Cadaver study. Cadaver laboratory equipped with fluoroscopy, surgical spine implements, and radiofrequency generator. No live human subject; a fresh frozen (and thawed) cadaver torso was used for the study. Titanium and stainless steel pedicle screws were placed in the lumbar spine of a fresh frozen cadaver torso with real-time fluoroscopic guidance. Conventional RFN cannula placement was performed at the level of pedicle screws and a control (nonsurgically altered) lumbar level. Neurotomy was performed with conventional radiofrequency lesioning parameters. Temperatures were recorded at multiple sites through thermistor probes. Direct contact of the radiofrequency cannula with the pedicle screws during conventional RFN produced a substantial increase in temperature in the surrounding soft tissues. A small increase in temperature occurred at the same sites at the control level. Titanium and stainless steel pedicle screws are capable of sustaining large increases in temperature when the radiofrequency probe comes in contact with the screw. These results are suggestive that pedicle screws could serve as a possible source of tissue heating and thermal injury during RFN. Wiley Periodicals, Inc.

  20. Prospective, pilot evaluation of the performance of nanofractional radiofrequency for improvement of skin texture via skin resurfacing.

    Science.gov (United States)

    Bohnert, Krista; Dorizas, Andrew; Sadick, Neil

    2018-02-01

    The latest generation of radiofrequency, nanofractional radiofrequency, allows the heat energy to be delivered through the use of pins or needles as electrodes, facilitating increased efficacy and reduced pain, downtime, and side effects. The objective of this prospective pilot clinical study was to evaluate the efficacy of nanofractional radiofrequency in skin resurfacing. Seventeen subjects were enrolled in the study, and each received three nanofractional radiofrequency (160-pin tip) treatments in the facial area at 3-week intervals. Follow-up visits were scheduled at 1 and 2 months after the final treatment. Clinical photography, patient, and investigator assessments were conducted during the treatment visits and follow-up. All subjects completed the study. At the 1- and 2-month follow-up, there was a moderate to significant improvement (2.6 and 3.5, respectively, P = .01) according to the investigator global esthetic improvement scale rating. Most subjects reported that they were satisfied or very satisfied with the outcome and level of comfort. Nanofractional radiofrequency is a safe and effective strategy for improving texture, tone, and skin laxity with high patient satisfaction and tolerable safety profile. © 2017 Wiley Periodicals, Inc.

  1. Modes of oscillation in radiofrequency Paul traps

    DEFF Research Database (Denmark)

    Landa, H.; Reznik, B.; Drewsen, M.

    2012-01-01

    We examine the time-dependent dynamics of ion crystals in radiofrequency traps. The problem of stable trapping of general threedimensional crystals is considered and the validity of the pseudopotential approximation is discussed. We analytically derive the micromotion amplitude of the ions...

  2. Pulsed Radiofrequency Ablation for Treating Sural Neuralgia.

    Science.gov (United States)

    Abd-Elsayed, Alaa; Jackson, Markus; Plovanich, Elizabeth

    2018-01-01

    Sural neuralgia is persistent pain in the distribution of the sural nerve that provides sensation to the lateral posterior corner of the leg, lateral foot, and fifth toe. Sural neuralgia is a rare condition but can be challenging to treat and can cause significant limitation. We present 2 cases of sural neuralgia resistant to conservative management that were effectively treated by pulsed radiofrequency ablation. A 65-year-old female developed sural neuralgia after a foot surgery and failed conservative management. She had successful sural nerve blocks, and pulsed radiofrequency ablation led to an 80% improvement in her pain. A 33-year-old female presented with sural neuralgia secondary to two falls. The patient had tried several conservative modalities with no success. We performed diagnostic blocks and pulsed radiofrequency ablation, and the patient reported 80% improvement in her pain. Pulsed radiofrequency ablation may be a safe and effective treatment for patients with sural neuralgia that does not respond to conservative therapy. However, studies are needed to elucidate its effectiveness and safety profile.

  3. Radiofrequency and microwave interactions between biomolecular systems

    Czech Academy of Sciences Publication Activity Database

    Kučera, Ondřej; Cifra, Michal

    2016-01-01

    Roč. 42, č. 1 (2016), s. 1-8 ISSN 0092-0606 R&D Projects: GA ČR(CZ) GA15-17102S Institutional support: RVO:67985882 Keywords : Cell signaling * Radiofrequency * Bioelectrodynamics Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.241, year: 2016

  4. Management of trigeminal neuralgia by radiofrequency ...

    African Journals Online (AJOL)

    The outcome depends on the type of TN with best results with classical idiopathic type. Also better results occurred with isolated V3 affection. The radiofrequency thermocoagulation of trigeminal nerve is a low risk, highly effective and minimally invasive procedure that should be started with in all cases of TN.

  5. Potential health risks due to telecommunications radiofrequency ...

    African Journals Online (AJOL)

    Background: The global system mobile telecommunications system (GSM) which was recently introduced in Nigeria is now being used by over 40 million people in Nigeria. The use of GSM is accompanied with exposure of the users to radiofrequency radiation (RFR), which if significant, may produce health hazards. This is ...

  6. Radiofrequency catheter oblation in atrial flutter

    International Nuclear Information System (INIS)

    Yan Ji; Wang Heping; Xu Jian; Liu Fuyuan; Fan Xizhen; An Chunsheng; Han Xiaoping; Ding Xiaomei; Wang Jiasheng; Gu Tongyuan

    2002-01-01

    Objective: To evaluate the radiofrequency catheter ablation for type I atrial flutter through application of Holo catheter labelling with anatomic imaging localization to ablate the isthmus of IVCTA during complete double-way block. Methods: Eleven cases with type I atrial flutter undergone Holo catheter labelling technique and consecution with conduction time change of coronary venous sinus orifice with-right atrial lower lateral wall pace excitation, were performed with radiofrequency catheter ablation for the isthmus outcoming with complete double-way conduction block. Results: All together 11 cases with 4 of atrial flutter and 7 of sinus rhythm were undergone radiofrequency catheter ablation resulting with double-way conduction block of the isthmus accompanied by prolongation of right atrial conduction time 56.0 ± 2.3 ms and 53.0 ± 4.6 ms respectively. The right atrial excitation appeared to be in clockwise and counter-clockwise of single direction. No recurrence occurred during 3-34 months follow up with only one showing atrial fibrillation. Conclusions: The application of Holo catheter labelling technique with anatomic imaging localization to achieve the double-way conduction block by radiofrequency catheter ablation of TVC-TA isthmus, is a reliable method for treating atrial flutter

  7. Exploring channeling optimized radiofrequency energy: a review of radiofrequency history and applications in esthetic fields.

    Science.gov (United States)

    Belenky, Inna; Margulis, Ariel; Elman, Monica; Bar-Yosef, Udi; Paun, Silviu D

    2012-03-01

    Because of its high efficiency and safety, radiofrequency (RF) energy is widely used in the dermatological field for heating biological tissue in various esthetic applications, including skin tightening, skin lifting, body contouring, and cellulite reduction. This paper reviews the literature on the use of nonablative RF energy in the esthetic field and its scientific background. The purpose of this article is to describe in detail the extensive use of medical devices based on RF technology, the development of these medical devices over the years, and recent developments and trends in RF technology. The authors conducted a systematic search of publications that address safety and efficacy issues, technical system specifications, and clinical techniques. Finally, the authors focused on their own clinical experiences with the use of patented Channeling Optimized RF Energy technique and mechanical massage. An in-vivo study was conducted in domestic pigs, with a thermal video camera. Twenty-seven female patients participated in a cellulite and body shaping study. The treatments were conducted according to a three-phase protocol. An additional 16 females participated in a skin tightening case study. All of the patients underwent three treatment sessions at 3-week intervals, each according to a protocol specific to the area being treated. The review of the literature on RF-based systems revealed that these systems are safe, with low risks for potential side effects, and effective for cellulite, body contouring, and skin tightening procedures. The in-vivo measurements confirmed the theory that the penetration depth of RF is an inverse function of its frequency, and using a vacuum mechanism makes an additional contribution to the RF energy penetration. The heating effect of RF was also found to increase blood circulation and to induce collagen remodeling. The results from the cellulite and body shaping treatments showed an overall average improvement of 55% in the

  8. Auxiliary bearing design considerations for gas cooled reactors

    International Nuclear Information System (INIS)

    Penfield, S.R. Jr.; Rodwell, E.

    2001-01-01

    The need to avoid contamination of the primary system, along with other perceived advantages, has led to the selection of electromagnetic bearings (EMBs) in most ongoing commercial-scale gas cooled reactor (GCR) designs. However, one implication of magnetic bearings is the requirement to provide backup support to mitigate the effects of failures or overload conditions. The demands on these auxiliary or 'catcher' bearings have been substantially escalated by the recent development of direct Brayton cycle GCR concepts. Conversely, there has been only limited directed research in the area of auxiliary bearings, particularly for vertically oriented turbomachines. This paper explores the current state-of-the-art for auxiliary bearings and the implications for current GCR designs. (author)

  9. Electrospinning of aligned fibers with adjustable orientation using auxiliary electrodes

    International Nuclear Information System (INIS)

    Arras, Matthias M L; Grasl, Christian; Schima, Heinrich; Bergmeister, Helga

    2012-01-01

    A conventional electrospinning setup was upgraded by two turnable plate-like auxiliary high-voltage electrodes that allowed aligned fiber deposition in adjustable directions. Fiber morphology was analyzed by scanning electron microscopy and attenuated total reflection Fourier transform infrared spectroscopy (FTIR-ATR). The auxiliary electric field constrained the jet bending instability and the fiber deposition became controllable. At target speeds of 0.9 m s −1 90% of the fibers had aligned within 2°, whereas the angular spread was 70° without the use of auxiliary electrodes. It was even possible to orient fibers perpendicular to the rotational direction of the target. The fiber diameter became smaller and its distribution narrower, while according to the FTIR-ATR measurement the molecular orientation of the polymer was unaltered. This study comprehensively documents the feasibility of directed fiber deposition and offers an easy upgrade to existing electrospinning setups. (paper)

  10. Extensions of the auxiliary field method to solve Schroedinger equations

    International Nuclear Information System (INIS)

    Silvestre-Brac, Bernard; Semay, Claude; Buisseret, Fabien

    2008-01-01

    It has recently been shown that the auxiliary field method is an interesting tool to compute approximate analytical solutions of the Schroedinger equation. This technique can generate the spectrum associated with an arbitrary potential V(r) starting from the analytically known spectrum of a particular potential P(r). In the present work, general important properties of the auxiliary field method are proved, such as scaling laws and independence of the results on the choice of P(r). The method is extended in order to find accurate analytical energy formulae for radial potentials of the form aP(r) + V(r), and several explicit examples are studied. Connections existing between the perturbation theory and the auxiliary field method are also discussed

  11. Extensions of the auxiliary field method to solve Schroedinger equations

    Energy Technology Data Exchange (ETDEWEB)

    Silvestre-Brac, Bernard [LPSC Universite Joseph Fourier, Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, Avenue des Martyrs 53, F-38026 Grenoble-Cedex (France); Semay, Claude; Buisseret, Fabien [Groupe de Physique Nucleaire Theorique, Universite de Mons-Hainaut, Academie universitaire Wallonie-Bruxelles, Place du Parc 20, B-7000 Mons (Belgium)], E-mail: silvestre@lpsc.in2p3.fr, E-mail: claude.semay@umh.ac.be, E-mail: fabien.buisseret@umh.ac.be

    2008-10-24

    It has recently been shown that the auxiliary field method is an interesting tool to compute approximate analytical solutions of the Schroedinger equation. This technique can generate the spectrum associated with an arbitrary potential V(r) starting from the analytically known spectrum of a particular potential P(r). In the present work, general important properties of the auxiliary field method are proved, such as scaling laws and independence of the results on the choice of P(r). The method is extended in order to find accurate analytical energy formulae for radial potentials of the form aP(r) + V(r), and several explicit examples are studied. Connections existing between the perturbation theory and the auxiliary field method are also discussed.

  12. Reactor auxiliary cooling facility and coolant supplying method therefor

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Koji; Kinoshita, Shoichiro

    1996-06-07

    A reactor auxiliary cooling facility of the present invention comprises a coolant recycling line for recycling coolants by way of a reactor auxiliary coolant pump and a cooling load, a gravitational surge tank for supplying coolants to the coolant recycling line and a supplemental water supplying line for supplying a supply the supplemental water to the tank. Then, a pressurization-type supply water surge tank is disposed for operating the coolant recycling line upon performing an initial system performance test in parallel with the gravitational surge tank. With such a constitution, the period of time required from the start of the installation of reactor auxiliary cooling facilities to the completion of the system performance test can be shortened at a reduced cost without enlarging the scale of the facility. (T.M.)

  13. Linearized curvatures for auxiliary fields in the de Sitter space

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, M A

    1988-09-19

    New consistent linearized curvatures in the de Sitter space are constructed. The sequence of actions, describing bosonic and fermionic gauge auxiliary fields, is found based on these curvatures. The proposed actions are parametrized by two integer parameters, n greater than or equal to 0 and m greater than or equal to 0. The simplest case n=m=0 corresponds in the flat limit to the auxiliary fields of 'new minimal' supergravity. The hamiltonian formulation is developed for the auxiliary fields suggested; hamiltonians and first- and second-class constraints are constructed. Using these results, it is shown that the systems of fields proposed possess no dynamical degrees of freedom in de Sitter and flat spaces. In addition the hamiltonian formalism is analysed for some free dynamical systems based on linearized higher-spin curvatures introduced previously.

  14. Reactor auxiliary cooling facility and coolant supplying method therefor

    International Nuclear Information System (INIS)

    Ando, Koji; Kinoshita, Shoichiro.

    1996-01-01

    A reactor auxiliary cooling facility of the present invention comprises a coolant recycling line for recycling coolants by way of a reactor auxiliary coolant pump and a cooling load, a gravitational surge tank for supplying coolants to the coolant recycling line and a supplemental water supplying line for supplying a supply the supplemental water to the tank. Then, a pressurization-type supply water surge tank is disposed for operating the coolant recycling line upon performing an initial system performance test in parallel with the gravitational surge tank. With such a constitution, the period of time required from the start of the installation of reactor auxiliary cooling facilities to the completion of the system performance test can be shortened at a reduced cost without enlarging the scale of the facility. (T.M.)

  15. Nonsurgical tightening of skin laxity: a new radiofrequency approach.

    Science.gov (United States)

    Rusciani, Antonio; Curinga, Giuseppe; Menichini, Giulio; Alfano, Carmine; Rusciani, Luigi

    2007-04-01

    Improvement in skin laxity can be difficult to achieve without invasive surgical procedures. Monopolar radiofrequency (RF) treatment is used by physicians to heat skin and promote tissue tightening and contouring. RF technology produces an electric current that generates heat through resistance in the dermis and subcutaneous tissue. The thermal effect depends on the conductivity features of the treated tissue. When heated, collagen fibrils will denature and contract, which is believed to lead to the observed tissue tightening. Ninety-three consecutive patients with mild to moderate laxity were included in the study. The Surgitron Dual Frequency RF (Radiowave technology, Ellman International) was used to treat skin laxity. The application of RF energy took place in an ambulatory setting with no need for skin sterilization or anesthesia. Patients immediately noticed a microlifting retraction in the treated tissues according to the vectors mapped in the area. There were no significant complications and the majority of patients were satisfied with the procedure and able to return to their daily routine after leaving the office, thereby substantiating the popularity of noninvasive rejuvenating procedures.

  16. Experimental investigation of a directionally enhanced DHX concept for high temperature Direct Reactor Auxiliary Cooling Systems

    International Nuclear Information System (INIS)

    Hughes, Joel T.; Blandford, Edward D.

    2016-01-01

    Highlights: • A novel directional heat exchanger design has been developed. • Hydrodynamic tests have been performed on the proposed design. • Heat transfer performance is inferred by hydrodynamic results. • Results are discussed and future work is suggested. - Abstract: The use of Direct Reactor Auxiliary Cooling Systems (DRACSs) as a safety-related decay heat removal system for advanced reactors has developed historically through the Sodium Fast Reactor (SFR) community. Beginning with the EBR-II, DRACSs have been utilized in a large number of past and current SFR designs. More recently, the DRACS has been adopted for Fluoride Salt-Cooled High-Temperature Reactors (FHRs) for similar decay heat removal functions. In this paper we introduce a novel directionally enhanced DRACS Heat Exchanger (DHX) concept. We present design options for optimizing such a heat exchanger so that shell-side heat transfer is enhanced in one primary coolant flow direction and degraded in the opposite coolant flow direction. A reduced-scale experiment investigating the hydrodynamics of a directionally enhanced DHX was built and the data collected is presented. The concept of thermal diodicity is expanded to heat exchanger technologies and used as performance criteria for evaluating design options. A heat exchanger that can perform as such would be advantageous for use in advanced reactor concepts where primary coolant flow reversal is expected during Loss-of-Forced-Circulation (LOFC) accidents where the ability to circulate coolant is compromised. The design could also find potential use in certain advanced Sodium Fast Reactor (SFR) designs utilizing fluidic diode concepts.

  17. Experimental investigation of a directionally enhanced DHX concept for high temperature Direct Reactor Auxiliary Cooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Joel T.; Blandford, Edward D., E-mail: edb@unm.edu

    2016-07-15

    Highlights: • A novel directional heat exchanger design has been developed. • Hydrodynamic tests have been performed on the proposed design. • Heat transfer performance is inferred by hydrodynamic results. • Results are discussed and future work is suggested. - Abstract: The use of Direct Reactor Auxiliary Cooling Systems (DRACSs) as a safety-related decay heat removal system for advanced reactors has developed historically through the Sodium Fast Reactor (SFR) community. Beginning with the EBR-II, DRACSs have been utilized in a large number of past and current SFR designs. More recently, the DRACS has been adopted for Fluoride Salt-Cooled High-Temperature Reactors (FHRs) for similar decay heat removal functions. In this paper we introduce a novel directionally enhanced DRACS Heat Exchanger (DHX) concept. We present design options for optimizing such a heat exchanger so that shell-side heat transfer is enhanced in one primary coolant flow direction and degraded in the opposite coolant flow direction. A reduced-scale experiment investigating the hydrodynamics of a directionally enhanced DHX was built and the data collected is presented. The concept of thermal diodicity is expanded to heat exchanger technologies and used as performance criteria for evaluating design options. A heat exchanger that can perform as such would be advantageous for use in advanced reactor concepts where primary coolant flow reversal is expected during Loss-of-Forced-Circulation (LOFC) accidents where the ability to circulate coolant is compromised. The design could also find potential use in certain advanced Sodium Fast Reactor (SFR) designs utilizing fluidic diode concepts.

  18. High Performance Auxiliary Power Unit Technology Demonstrator.

    Science.gov (United States)

    1980-12-01

    aft bearings 1.13 P3 - Power producer CDP 1.14 DPHE - Lube pressure drop at heat exchanger 1.15 POFP - Load airflow orifice pressure 1.16 DPOFP - Load...P𔃽I -PSI G PEBL -PSIG P2 -PS.IG DPHE -PID POFP -F Iu 0. 022±_ 77. 3478 6o5. 6 4±4 ±8L-. 4852 19. 51-17.4 DPOFP -PSID Ni -,. N2-i -RPM NSATM -FPM...28. 0250 83. 3505 29. 861 1:9. 7680 PGi -PSIG PEBL -PSIG P3 -PSIG DPHE -PSID POFP -PSIG 0. 0100 77. 9199 72.4862 17. 25 ±19. 4122 1= DPOFP -PSID NI

  19. Alkali Metal Heat Pipe Life Issues

    International Nuclear Information System (INIS)

    Reid, Robert S.

    2004-01-01

    One approach to fission power system design uses alkali metal heat pipes for the core primary heat-transfer system. Heat pipes may also be used as radiator elements or auxiliary thermal control elements. This synopsis characterizes long-life core heat pipes. References are included where information that is more detailed can be found. Specifics shown here are for demonstration purposes and do not necessarily reflect current Nasa Project Prometheus point designs. (author)

  20. Improving Semi-Supervised Learning with Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae

    Deep generative models based upon continuous variational distributions parameterized by deep networks give state-of-the-art performance. In this paper we propose a framework for extending the latent representation with extra auxiliary variables in order to make the variational distribution more...... expressive for semi-supervised learning. By utilizing the stochasticity of the auxiliary variable we demonstrate how to train discriminative classifiers resulting in state-of-the-art performance within semi-supervised learning exemplified by an 0.96% error on MNIST using 100 labeled data points. Furthermore...

  1. TMI-2 auxiliary building elevator shaft and pit decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Bengel, T.G.

    1986-01-01

    Decontamination of the elevator pit and shaft in the auxiliary building at Three Mile Island Unit 2 (TMI-2) was performed to remove high radiation and contamination levels which prevented personnel from utilizing the elevator. The radiation and contamination levels in the TMI-2 auxiliary building elevator shaft have been reduced to the point where plant personnel are again permitted to ride in the elevator without a radiation work permit, with the exception of access to the 281-ft (basement) level. Based on the declassification and expanded use of the elevator, the task goal has been met. The tax expended 16.16 man-rem and 621 man-hours.

  2. Intrinsically safe electrical installations, auxiliary circuits and electric communication equipment

    Energy Technology Data Exchange (ETDEWEB)

    Herms, C D

    1981-11-19

    Technical progress has not stopped short of electrical systems in mining, so that three new chapters are new included in the VDE regulations leaflet No. 0118 on 'Installation of electrical systems in underground coal mining'. The regulations on intrinsically safe electric systems, auxiliary circuits and communication systems are briefly described, and grounds for the regulations are presented. The regulations already take account of European regulations on intrinsic safety which will soon be published in a European Regulation on Mine Explosions. In the chapters on auxiliary circuits and communication systems, protection against direct contact, fires, and explosions is discussed as well as the further goal of reliable signal transmission.

  3. Analysis and Measurement of NOx Emissions in Port Auxiliary Vessels

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez

    2013-09-01

    Full Text Available This paper is made NOx pollution emitted by port auxiliary vessels, specifically by harbour tugs, due to its unique operating characteristics of operation, require a large propulsion power changes discontinuously, also possess some peculiar technical characteristics, large tonnage and high propulsive power, that differentiate them from other auxiliary vessels of the port. Taking into account all the above features, there are no studies of the NOx emission engines caused by different working regimes of power because engine manufacturers have not measured these emissions across the range of operating power, but usually we only report the pollution produced by its engines to a maximum continuous power.

  4. Indication of the radiofrequency induced lesion size by pre-ablation measurements

    DEFF Research Database (Denmark)

    Stagegaard, Niels; Petersen, Helen Høgh; Chen, Xu

    2005-01-01

    BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool for asses......BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool...... for assessing these factors prior to ablation may indicate the lesion size which will be obtained for any given catheter position. METHODS AND RESULTS: Radiofrequency ablation was performed in vitro on strips of left ventricular porcine myocardium during two different levels of convective cooling (0 or 0.1 m....../s), two different contact pressures (10 or 30 g) and parallel or perpendicular electrode-tissue orientation using 7F 4 mm tip catheters. Prior to ablation the impedance rise (DeltaIMP) caused by the obtained contact and the temperature rise with a 0.6 W 5 s test pulse (DeltaT) were measured. Subsequently...

  5. Single-tube condensation experiment in Passive Auxiliary Feedwater System of APR1400+

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chang Wook; No, Hee Cheon; Yun, Bong Yo; Jeon, Byong Guk [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2012-05-15

    Conventional Korean nuclear power plants, Advanced Power Reactors (APR), are characterized by an active cooling system. However, Active cooling system may not prevent significant damage without any AC power source available for its operation as vividly illustrated through the recent Fukushima incident. In the APR1400+ to be designed, an independent passive cooling system was added in order to overcome the aforementioned shortcomings. In the Passive Auxiliary Feedwater System (PAFS), gravity force and density difference between steam and water are used. The system comprises of 240 condensation tubes to efficiently remove decay heat. Before applying the PAFS to APR1400+, the system's safety and heat removal performance must be verified. The present study experimentally evaluates the heat removal performance of a single tube in the PAFS. The objectives of SCOP (Single-tube Condensation experiment facility of PAFS) are the evaluation of the heat removal performance in the tube of the PAFS and database construction under various tube designs and test conditions. Reaching these objectives, we developed advanced measurement techniques for the amount of moisture, heat flux, and water film thickness.

  6. Improvement of Equipment reliability for Auxiliary Feed Water System

    Energy Technology Data Exchange (ETDEWEB)

    Deok, Lee Sang; Kwan, Lee Yong [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    According to AP913 ER) of INPO, Number of the event related to equipment is higher than others like external or human performance. In the top 25 systems, Auxiliary feed water system is the seventh highest among systems. AWFS consists of many component and complex system and Main Function of AFWS is to supply feedwater to the steam generators for the removal of heat from the RCS(Reactor Coolant System) in event the main feedwater system is unavailable following a transient or accident. Reliability of component means how well operate on demands and monitoring is necessary to keep track of condition of component. If component performance is lower than the required value, corrective action for failure mode should be done. The objective of this study is focused to improve of AF pump by adding the tasks of SHR(System Health Report) into the task of system engineer walkdown of PMT(Preventive Maintenance Template). Increasing the reliability of AF pump will contribute to improvement of reliability of AFWS. Based on operating history, there was high vibration of AF pump during performance test. In that case, there were a lot of maintenance works for normal operation of AF pump. Vibration problem related pump can't be detected by tasks of SE walkdown because it's not running during normal operation except for surveillance test. CHR(Component Health Report) of AF pump in AFWS can be made from necessary part which means monitoring and functional failure because problem of Stand-by pump can be covered by conducting monitoring and analysis of functional failure. To improve reliability of AF pump, walkdown of PMT and SHR should be conducted both in accordance with surveillance test frequency. Health of AF pump based on operation history can be verified first and then can find out which parts of pump are weak. Finally, weak part can be managed intensively and failure can be reduced according to SE walkdown. But this work can be risky and burdensome because all parts of

  7. Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

    Science.gov (United States)

    Cartier, Victoire; Boursier, Jérôme; Lebigot, Jérôme; Oberti, Frédéric; Fouchard-Hubert, Isabelle; Aubé, Christophe

    2016-03-01

    Thermo-ablation by radiofrequency is recognized as a curative treatment for early-stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure. A total of 171 consecutive patients with 214 hepatocellular carcinomas were retrospectively included. One hundred fifty-eight tumors were treated with an expandable monopolar electrode and 56 with a multipolar technique using several linear bipolar electrodes. Imaging studies at 6 weeks after treatment, then every 3 months, assessed local effectiveness. Radiofrequency failure was defined as persistent residual tumor after two sessions (primary radiofrequency failure) or local tumor recurrence during follow-up. This study received institutional review board approval (number 2014/77). Imaging showed complete tumor ablation in 207 of 214 lesions after the first session of radiofrequency. After a second session, only two cases of residual viable tumor were observed. During follow-up, there were 46 local tumor recurrences. Thus, radiofrequency failure occurred in 48/214 (22.4%) cases. By multivariate analysis, technique (P radiofrequency failure. Failure rate was lower with the multipolar technique for tumors radiofrequency, multipolar radiofrequency improves tumor ablation with a subsequent lower rate of local tumor recurrence. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  8. From mini-invasive to non-invasive treatment using monopolar radiofrequency: the next orthopaedic frontier.

    Science.gov (United States)

    Whipple, Terry L

    2009-10-01

    Tendinopathy arises from a failed tendon healing process. Current non-invasive therapeutic alternatives are anti-inflammatory in nature, and outcomes are unpredictable. The benefit of invasive alternatives resides in the induction of the healing response. A new technology that uses non-invasive monopolar capacitive coupled radiofrequency has demonstrated the ability to raise temperatures in tendons and ligaments above 50 degrees C, the threshold for collagen modulation, tissue shrinkage and recruitment of macrophages, fibroblasts, and heat shock protein factors, without damaging the overlying structures, resulting in activation of the wound healing response. Monopolar capacitive-coupled radiofrequency offers a new non-invasive choice for tendinopathies and sprained ligaments. It does not interfere with subsequent surgical procedures should they become necessary.

  9. Radiofrequency hyperthermia for advanced malignant liver tumors

    International Nuclear Information System (INIS)

    Nagata, Y.; Okuno, Y.; Mitsumori, M.; Akuta, K.; Nishimura, Y.; Masunaga, S.; Kanamori, S.; Fujishiro, M.; Hiraoka, M.; Takahashi, M.; Abe, M.

    1996-01-01

    Purpose: To evaluate thermometry and the clinical results of radiofrequency (RF) thermotherapy for advanced malignant liver tumors. Materials and Methods One-hundred and seventy-three patients with malignant liver tumors treated between 1983 and 1995 underwent hyperthermia. Surgery were contraindicated in all patients. The 173 tumors consisted of 114 hepatocellular carcinomas(HCCs), and 59 non-HCCs(45 metastatic liver tumors and 12 cholangiocarcinomas). Eight MHz RF capacitive heating equipment was used for hyperthermia. Two opposing 25-cm or 30-cm electrodes were generally used for heating liver tumors. Our standard protocol was to administer hyperthermia 40-50 minutes twice a week to a total of 8 sessions. Temperature of the liver tumor was measured by microthermocouples. In each patient, a single catheter was inserted into the liver tumor through the normal liver. Transcatheter arterial embolization, radiotherapy, immunotherapy, and chemotherapy were combined with hyperthermia depending on the patient's liver function and tumor location. The therapeutic efficacy was evaluated by the change in tumor size assessed by computed tomography (CT) three or four months after the completion of treatment. Results One-hundred and forty (81%) of 173 patients underwent hyperthermia more than 4 times. Thermometry could be performed in 77(55%) of these 140 patients. Neither systolic nor diastolic blood pressure changed significantly after hyperthermia. However, pulse rate significantly increased from 82.8 ± 1.1 to 96.5 ± 1.3 beats/min. Only 21 patients (11%) showed a decrease in pulse rate after hyperthermia. Body temperature increased from 36.3 ±0.1 to 37.4±0.2 after hyperthermia. Sequelae of hyperthermia included focal fat burning in 20 (12%), gastric ulceration in 4 (2%), and liver necrosis in 1(1%). Sequelae of thermometry were severe peritoneal pain in 7 (11%), intraperitoneal hematoma in 1(1%), and pneumothorax in one (1%) patient. The maximal tumor temperature

  10. Effects of Radiofrequency Induced local Hyperthermia on Normal Canine Liver

    International Nuclear Information System (INIS)

    Suh, Chang Ok; Loh, John J. K.; Seong, Jin Sil

    1991-01-01

    In order to assess the effects of radiofrequency-induced local hyperthermia on the normal liver, histopathologic findings and biochemical changes after localized hyperthermia in canine liver were studied. Hyperthermia was externally administered using the Thermotron RF-8 (Yamamoto Vinyter Co., Japan; Capacitive type heating machine) with parallel opposed electrodes. Thirteen dogs were used and allocated into one control group (N=3) and two treatment groups according to the treatment temperature. Group I (N=5) was heated with 42.5±0.5.deg.C for 30 minutes, and Group(N=5) was heated with 45±0.5.deg.C for 15-30 minutes. Samples of liver tissue were obtained through a needle biopsy immediately after hyperthermia and 7, 14 and 28 days after treatment and examined for SGOT, SGPT and alkaline phosphatase. Although SGOT and SGPT were elevated after hyperthermia in both groups (three of five in each group), there was no liver cell necrosis or hyperthermia related mortality in Group I. A hydropic swelling of hepatocytes was prominent histologic finding. Hyperthermia with 45.deg.C for 30 minutes was fatal and showed extensive liver cell necrosis. In conclusion, liver damage day heat of 42.5±0.5.deg.C for 30 minutes is reversible, and liver damage by heat of 45±0.5.deg.C for 30 minutes can be fatal or irreversible. However, these results cannot be applied directly to human trial. Therefore, in order to apply hyperthermic treatment on human liver tumor safely, close observation of temperature with proper thermometry is mandatory. Hyperthermic treatment should be confined to the tumor area while sparing a normal liver as much as possible

  11. Image-guided radiofrequency ablation (RFA) of spinal tumors

    International Nuclear Information System (INIS)

    Gevargez, Athour; Groenemeyer, Dietrich H.W.

    2008-01-01

    Purpose: To evaluate retrospectively the efficacy and safety of radiofrequency ablation (RFA) in patients with spinal tumors. Materials and methods: Forty-one patients (25 men, 16 women; age range, 46-82 years) with nonresectable primary or secondary tumor involvement of the spine unresponsive to chemo- and radiotherapy received RFA treatment. Two radiofrequency ablation systems, one with a cool-tip electrode and one with an expandable electrode catheter, were used. Both systems work impedance controlled with a power output of 150- 200 W. Each coagulation cycle lasted 12-15 min depending on tumor impedance. Several single RFA cycles of 15 min each were used for overlapping RFAs in tumors with diameters of more than 3 cm. Temperature was kept between 50 deg. C and 120 deg. C and was chosen according to spinal cord distance and patient heat tolerance during the ablation. Multi-slice computed tomography (CT) combined with C-arm fluoroscopy guided the intervention. Efficacy outcomes were assessed after about 6 weeks, 6 months, and more than 6 months using standardized questionnaires and indices regarding tumor pain, pain disability, functional activities, quality of life, neurological status, and tumor progression. Results: RFA significantly reduced tumor-induced pain within 6 weeks, improved daily activities, and maintained quality of life. Mean time to tumor progression was 730 ± 54 days (Kaplan-Meier estimate). No RFA-associated complications were reported. Conclusion: RFA of primary and secondary spinal tumors, which were unresponsive to chemo- and radiotherapy and prone to progression, is a safe, resource-saving, and highly effective percutaneous technique in patients with nonresectable spinal tumors

  12. Development of KALIMER auxiliary sodium and cover gas management system

    International Nuclear Information System (INIS)

    Kwon, Sang Woon; Hwang, Sung Tae

    1996-11-01

    The objectives of this report are to develop and to describe the auxiliary liquid metal and cover gas management systems of KALIMER. the system includes following system: (1) Auxiliary liquid metal system (2) Inert gas receiving and processing system (3) Impurity monitoring and analysis system. Auxiliary liquid metal and cover gas management system of KALIMER was developed. Functions of each systems and design basis were describes. The auxiliary liquid metal system receives, transfers, and purifies all sodium used in the plant. The system furnishes the required sodium quantity at the pressure, temperature, flow rate, and purity specified by the interfacing system. The intermediated sodium processing subsystem (ISPS) provides continuous purification of IHTS sodium, as well as performs the initial fill operation for both the IHTS and reactor vessel. The primary sodium processing subsystem provides purification (cold trapping) for sodium used in the reactor vessel. The inert gas receiving and processing (IGRP) system provides liquefied and ambient gas storage, delivers inert gases of specified composition and purity at regulated flow rates and pressures to points of usage throughout the KALIMER, and accepts the contaminated gases through its vacuum facilities for storage and transfer to the gas radwaste system. Three gases are used in the KALIMER: helium, argon, and nitrogen. 11 tabs., 12 figs. (Author)

  13. Auxiliary controller for time-to-digital converter module readout

    International Nuclear Information System (INIS)

    Ermolin, Yu.V.

    1992-01-01

    The KD-225 auxiliary controller for time-to-digital converter module readout in the SUMMA crate is described. After readout and preliminary processing the data are written in the P-140 buffer memory module. The controller is used in the FODS-2 experimental setup data acquisition system. 12 refs.; 1 fig

  14. Auxiliary equation method for solving nonlinear partial differential equations

    International Nuclear Information System (INIS)

    Sirendaoreji,; Jiong, Sun

    2003-01-01

    By using the solutions of an auxiliary ordinary differential equation, a direct algebraic method is described to construct several kinds of exact travelling wave solutions for some nonlinear partial differential equations. By this method some physically important nonlinear equations are investigated and new exact travelling wave solutions are explicitly obtained with the aid of symbolic computation

  15. 76 FR 22295 - National Poultry Improvement Plan and Auxiliary Provisions

    Science.gov (United States)

    2011-04-21

    ... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection 9 CFR Part 145 [Docket No. APHIS-2009-0031] RIN 0579-AD21 National Poultry Improvement Plan and Auxiliary Provisions Correction In rule document 2011-6539 appearing on pages 15791-15798 in the issue of Tuesday, March 22, 2011, make the...

  16. Development of KALIMER auxiliary sodium and cover gas management system

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Sang Woon; Hwang, Sung Tae [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-11-01

    The objectives of this report are to develop and to describe the auxiliary liquid metal and cover gas management systems of KALIMER. the system includes following system: (1) Auxiliary liquid metal system (2) Inert gas receiving and processing system (3) Impurity monitoring and analysis system. Auxiliary liquid metal and cover gas management system of KALIMER was developed. Functions of each systems and design basis were describes. The auxiliary liquid metal system receives, transfers, and purifies all sodium used in the plant. The system furnishes the required sodium quantity at the pressure, temperature, flow rate, and purity specified by the interfacing system. The intermediated sodium processing subsystem (ISPS) provides continuous purification of IHTS sodium, as well as performs the initial fill operation for both the IHTS and reactor vessel. The primary sodium processing subsystem provides purification (cold trapping) for sodium used in the reactor vessel. The inert gas receiving and processing (IGRP) system provides liquefied and ambient gas storage, delivers inert gases of specified composition and purity at regulated flow rates and pressures to points of usage throughout the KALIMER, and accepts the contaminated gases through its vacuum facilities for storage and transfer to the gas radwaste system. Three gases are used in the KALIMER: helium, argon, and nitrogen. 11 tabs., 12 figs. (Author).

  17. Auxiliary basis expansions for large-scale electronic structure calculations.

    Science.gov (United States)

    Jung, Yousung; Sodt, Alex; Gill, Peter M W; Head-Gordon, Martin

    2005-05-10

    One way to reduce the computational cost of electronic structure calculations is to use auxiliary basis expansions to approximate four-center integrals in terms of two- and three-center integrals, usually by using the variationally optimum Coulomb metric to determine the expansion coefficients. However, the long-range decay behavior of the auxiliary basis expansion coefficients has not been characterized. We find that this decay can be surprisingly slow. Numerical experiments on linear alkanes and a toy model both show that the decay can be as slow as 1/r in the distance between the auxiliary function and the fitted charge distribution. The Coulomb metric fitting equations also involve divergent matrix elements for extended systems treated with periodic boundary conditions. An attenuated Coulomb metric that is short-range can eliminate these oddities without substantially degrading calculated relative energies. The sparsity of the fit coefficients is assessed on simple hydrocarbon molecules and shows quite early onset of linear growth in the number of significant coefficients with system size using the attenuated Coulomb metric. Hence it is possible to design linear scaling auxiliary basis methods without additional approximations to treat large systems.

  18. Specific features of auxiliary water supply at underground NPPs

    International Nuclear Information System (INIS)

    Pergamenshchik, B.K.; Pavlov, A.S.

    1991-01-01

    Specific features of auxiliary water supply systems for underground NPPs related to peculiarities of NPP basis equipment arrangement, are considered. Circulation water supply scheme, in which water cooling storage basin (cooling towers) with operational area corresponding to NPP power is on the surface and has traditional design, is proposed. Sufficiently high efficiency of the arrangement proposed is proved

  19. Verb and auxiliary movement in agrammatic Broca's aphasia

    NARCIS (Netherlands)

    Bastiaanse, Y.R.M.; Thompson, C.K.

    Verb production in agrammatic Broca's aphasia has repeatedly been shown to be impaired by a number of investigators. Not only is the number of verbs produced often significantly reduced, but verb inflections and auxiliaries are often omitted as well (e.g., Bastiaanse, Jonkers, & Moltmaker-Osinga,

  20. Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

    Directory of Open Access Journals (Sweden)

    Yanfeng Liu

    2017-10-01

    Full Text Available This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces the auxiliary heating by 7390 MJ, and reduces the annual operation cost by 2010 RMB. Under time and spatial partition heating, optimization analyses were conducted for the two system capacity parameters of the solar collector area and tank volume and the one operation parameter of auxiliary heater setting outlet temperature. The results showed that a reasonable choice of the solar collector area can reduce the dynamic annual cost, the increased tank volume is advantageous to heat storage, and the auxiliary heater setting outlet temperature have greater influence on the indoor heating effect. The advanced opening of solar water heating system and the normal opening of passive air vents are recommended. Based on the comparison of the two modes, the time and spatial partition heating technology is a better choice for rural dwellings.

  1. Fraxelated radiofrequency device for acne scars

    Science.gov (United States)

    Rao, Babar K.; Khokher, Sairah

    2012-09-01

    Acne scars can be improved with various treatments such as topical creams, chemical peels, dermal fillers, microdermabrasion, laser, and radiofrequency devices. Some of these treatments especially lasers and deep chemical peels can have significant side effects such as post inflammatory hyperpigmentation in darker skin types. Fraxelated RF Laser devices have been reported to have lower incidence of side effects in all skin phototypes. Nine patients between ages 18 and 35 of various skin phototypes were selected from a private practice and treated with a RF fraxelated device (E-matrix) for acne scars. Outcomes were measured by physician observation, subjective feedback received by patients, and comparison of before and after photographs. In this small group of patients with various skin phototypes, fraxelated radiofrequency device improved acne scars with minimal side effects and downtime.

  2. Arthroscopic surgery using radio-frequency electrocautery

    International Nuclear Information System (INIS)

    Takatsuka, Shigeyuki; Yoshida, Kan; Nakagawa, Kiyomasa; Yamamoto, Etsuhide; Kubota, Yoshiyuki; Narinobou, Masayoshi; Terai, Koichi; Hasegawa, Hiroshi

    2008-01-01

    Arthroscopic surgery using radio-frequency electrocautery was carried out on 23 temporomandibular joints (TMJs) in 13 patients. Because these patients did not respond to conservative therapy, surgery was indicated. Preoperative MRI showed anterior disc displacement without reduction in all patients. Disturbed translation was also recognized in all of the discs and mandibular condyles. Intraoperative arthroscopic examination showed severe fibrous adhesion in the upper joint compartment and disc displacement. Four joints showed perforation between the disc and retrodiscal tissue. Postoperative findings included an increased range of vertical maximal mouth opening and decreased pain on mandibular movement. Analyses of postoperative MRI indicated recovery of disc and condylar translation. These results suggested that the introduction of arthroscopic surgery using radiofrequency electrocautery would significantly reduce the number of patients with osteoarthritic TMJ disorders. (author)

  3. Temperature-controlled irrigated tip radiofrequency catheter ablation

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, Adrian

    1998-01-01

    INTRODUCTION: In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion......: We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip....

  4. Experimental study on the supercritical startup and heat transport capability of a neon-charged cryogenic loop heat pipe

    International Nuclear Information System (INIS)

    Guo, Yuandong; Lin, Guiping; He, Jiang; Bai, Lizhan; Zhang, Hongxing; Miao, Jianyin

    2017-01-01

    Highlights: • A neon-charged CLHP integrated with a G-M cryocooler was designed and investigated. • The CLHP can realize the supercritical startup with an auxiliary heat load of 1.5 W. • Maximum heat transport capability of the CLHP was 4.5 W over a distance of 0.6 m. • There existed an optimum auxiliary heat load to expedite the supercritical startup. • There existed an optimum charged pressure to reach the largest heat transfer limit. - Abstract: Neon-charged cryogenic loop heat pipe (CLHP) can realize efficient cryogenic heat transport in the temperature range of 30–40 K, and promises great application potential in the thermal control of future space infrared exploration system. In this work, extensive experimental studies on the supercritical startup and heat transport capability of a neon-charged CLHP integrated with a G-M cryocooler were carried out, where the effects of the auxiliary heat load applied to the secondary evaporator and charged pressure of the working fluid were investigated. Experimental results showed that the CLHP could successfully realize the supercritical startup with an auxiliary heat load of 1.5 W, and there existed an optimum auxiliary heat load and charged pressure of the working fluid respectively, to achieve the maximum temperature drop rate of the primary evaporator during the supercritical startup. The CLHP could reach a maximum heat transport capability of 4.5 W over a distance of 0.6 m corresponding to the optimum charged pressure of the working fluid; however, the heat transport capability decreased with the increase of the auxiliary heat load. Furthermore, the inherent mechanisms responsible for the phenomena observed in the experiments were analyzed and discussed, to provide a better understanding from the theoretical view.

  5. Effect of Radiofrequency Endometrial Ablation on Dysmenorrhea.

    Science.gov (United States)

    Wyatt, Sabrina N; Banahan, Taylor; Tang, Ying; Nadendla, Kavita; Szychowski, Jeff M; Jenkins, Todd R

    To examine rates of dysmenorrhea after radiofrequency endometrial ablation in patients with and without known dysmenorrhea symptoms prior to the procedure in a diverse population. Retrospective cohort study (Canadian Task Force classification II-2). Academic gynecology practice. A total of 307 women underwent endometrial ablation between 2007 and 2013 at our institution. Patients who had preoperative and postoperative pain symptom assessments as well as a description of pain timing recorded were included in our analysis. Exclusion criteria were age dysmenorrhea was evaluated. Demographic information and other outcome variables were used to evaluate factors associated with resolution of dysmenorrhea. A total of 307 patients who underwent radiofrequency endometrial ablation were identified. After exclusions, 296 charts were examined, and 144 patients met our enrollment criteria. The mean age of the study cohort was 45.4 ± 6.2 years; 57 patients (40%) were African American, 16 (11%) had a body mass index (BMI) > 40, and 41 (29%) were of normal weight. Preoperative dysmenorrhea was reported by 100 patients (69%); 48 of these patients (48%) experienced resolution of symptoms postoperatively. Only 3 of the 44 patients (7%) without preoperative dysmenorrhea reported new-onset dysmenorrhea postoperatively. Significantly fewer patients had dysmenorrhea after compared to before radiofrequency ablation (55 of 144 [38%] vs 100 of 144 [69%]; p dysmenorrhea after ablation was associated with reduction in bleeding volume (p = .048) but not with a reduction in frequency of bleeding (p = .12). Approximately one-half of women who undergo radiofrequency endometrial ablation to treat heavy menstrual bleeding who also have preoperative dysmenorrhea exhibit documented pain resolution after the procedure. Resolution of dysmenorrhea is more likely if menstrual flow volume is decreased postprocedure. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

  6. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

    Energy Technology Data Exchange (ETDEWEB)

    Majdalany, Bill S., E-mail: bmajdala@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States); Elliott, Eric D., E-mail: eric.elliott@osumc.edu [The Ohio State University Wexner Medical Center, Division of Interventional Radiology, Department of Radiology (United States); Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu; Hanje, A. James, E-mail: James.Hanje@osumc.edu [The Ohio State University Wexner Medical Center, Division of Gastroenterology and Hepatology, Department of Medicine (United States); Saad, Wael E. A., E-mail: wsaad@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States)

    2016-07-15

    Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

  7. Issues in epidemiological studies of radiofrequency workers

    International Nuclear Information System (INIS)

    Hocking, B.

    1985-01-01

    The paper reviews some of the issues in a proposed epidemiological study of radiofrequency workers. First a few other epidemiological studies are discussed to illustrate some of the common problems such as inadequate definition of effects and/or exposure. Then technical problems in determining dosage and responses as well as study design are reviewed, and finally the administrative aspects of ethics, industrial relations and costs are considered

  8. ROLE OF RADIOFREQUENCY ABLATION IN ADENOMA SEBACEUM

    Directory of Open Access Journals (Sweden)

    Ch. Madh

    2016-03-01

    Full Text Available Adenoma sebaceum, pathognomonic of tuberous sclerosis, are tiny angiofibromas which commonly occur over central part of face. Recurrence after treatment is common and hence a need for inexpensive, safe and efficient treatment is required. Radiofrequency ablation is a safe and an economical procedure and has been known to cause less scarring with good aesthetic results compared to other ablative methods such as electrocautery.

  9. Test facility for auxiliary cooling system (ACS) of fast breeder reactor for Power Reactor and Nuclear Fuel Development Corporation (PNC)

    International Nuclear Information System (INIS)

    1983-01-01

    In preparation of constructing ''Monju'', a prototype fast breeder reactor, PNC has been pushing forward its research and development projects and the ACS was constructed under these projects. The auxiliary cooling system is an important engineered safety feature, and is used for safe removal of heat from the reactor at the shutdown. The ACS serves as a means of testing and assessing the auxiliary cooling system for the ''Monju'' and is designed and manufactured to have one fifth capacity of the Monju. The air heat exchanger and the ACS system was designed to withstand higher temperature range of the conventional design code (MITI-501), and finned tubes were applied for effective heat removal. Preheating system was designed to heat up the whole system over 200 0 C within 20 hours to prevent sodium from freezing. Basic performance of ACS was verified satisfactorily by a series of performance tests, such as start up test, flow rate measurement and preheating test before delivery. The experience from designing and construction of ACS and data obtained by these tests will be very instructive for designing and construction of the ''Monju''. (author)

  10. Investigation of radiofrequency plasma sources for space travel

    International Nuclear Information System (INIS)

    Charles, C; Boswell, R W; Takahashi, K

    2012-01-01

    Optimization of radiofrequency (RF) plasma sources for the development of space thrusters differs from other applications such as plasma processing of materials since power efficiency, propellant usage, particle acceleration or heating become driving parameters. The development of two RF (13.56 MHz) plasma sources, the high-pressure (∼1 Torr) capacitively coupled ‘pocket rocket’ plasma micro-thruster and the low-pressure (∼1 mTorr) inductively coupled helicon double layer thruster (HDLT), is discussed within the context of mature and emerging electric propulsion devices. The density gradient in low-pressure expanding RF plasmas creates an electric field that accelerates positive ions out of the plasma. Generally, the total potential drop is similar to that of a wall sheath allowing the plasma electrons to neutralize the ion beam. A high-pressure expansion with no applied magnetic field can result in large dissociation rates and/or a collimated beam of ions of small area and a flowing heated neutral beam (‘pocket rocket’). A low-pressure expansion dominated by a magnetic field can result in the formation of electric double layers which produce a very directed neutralized beam of ions of large area (HDLT). (paper)

  11. Investigation of radiofrequency plasma sources for space travel

    Science.gov (United States)

    Charles, C.; Boswell, R. W.; Takahashi, K.

    2012-12-01

    Optimization of radiofrequency (RF) plasma sources for the development of space thrusters differs from other applications such as plasma processing of materials since power efficiency, propellant usage, particle acceleration or heating become driving parameters. The development of two RF (13.56 MHz) plasma sources, the high-pressure (˜1 Torr) capacitively coupled ‘pocket rocket’ plasma micro-thruster and the low-pressure (˜1 mTorr) inductively coupled helicon double layer thruster (HDLT), is discussed within the context of mature and emerging electric propulsion devices. The density gradient in low-pressure expanding RF plasmas creates an electric field that accelerates positive ions out of the plasma. Generally, the total potential drop is similar to that of a wall sheath allowing the plasma electrons to neutralize the ion beam. A high-pressure expansion with no applied magnetic field can result in large dissociation rates and/or a collimated beam of ions of small area and a flowing heated neutral beam (‘pocket rocket’). A low-pressure expansion dominated by a magnetic field can result in the formation of electric double layers which produce a very directed neutralized beam of ions of large area (HDLT).

  12. Radiofrequency amplifier based on a DC superconducting quantum interference device

    International Nuclear Information System (INIS)

    Martinis, J.M.; Hilbert, C.; Clarke, J.

    1986-01-01

    A method is described of amplifying a radiofrequency signal consisting of: disposing a single symmetrically biased dc SQUID and an input coil within a superconducting shield, the dc SQUID having a superconducting ring interrupted by two shunted Josephson junctions, and the input coil being inductively coupled solely to the ring of the single SQUID, establishing a constant magnetic flux threading the SQUID ring, applying the radiofrequency signal to the input coil from outside of the superconducting shield, obtaining an amplified radiofrequency signal solely from across the ring of the single SQUID, transmitting the amplified radiofrequency signal from across the SQUID ring to the outside of the superconducting shield

  13. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    Analytical Method of Auxiliary Sources solutions for plane wave scattering by circular impedance cylinders are derived by transformation of the exact eigenfunction series solutions employing the Hankel function wave transformation. The analytical Method of Auxiliary Sources solution thus obtained...

  14. Minimal set of auxiliary fields and S-matrix for extended supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Fradkin, E S; Vasiliev, M A [Physical Lebedev Institute - Moscow

    1979-05-19

    Minimal set of auxiliary fields for linearized SO(2) supergravity and one-parameter extension of the minimal auxiliary fields in the SO(1) supergravity are constructed. The expression for the S-matrix in SO(2) supergravity are given.

  15. Radiofrequency initiation and radiofrequency sustainment of laser initiated seeded high pressure plasma

    International Nuclear Information System (INIS)

    Paller, Eric S.; Scharer, John E.; Akhtar, Kamran; Kelly, Kurt; Ding, Guowen

    2001-01-01

    We examine radiofrequency initiation of high pressure(1-70 Torr) inductive plasma discharges in argon, nitrogen, air and organic seed gas mixtures. Millimeter wave interferometry, optical emission and antenna wave impedance measurements for double half-turn helix and helical inductive antennas are used to interpret the rf/plasma coupling, measure the densities in the range of 10 12 cm -3 and analyze the ionization and excited states of the gas mixtures. We have also carried out 193 nm excimer laser initiation of an organic gas seed plasma which is sustained at higher pressures(150 Torr) by radiofrequency coupling at 2.8 kW power levels

  16. Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

    International Nuclear Information System (INIS)

    Anfinsen, Ole-Gunnar

    1999-01-01

    The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks related to

  17. Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

    Energy Technology Data Exchange (ETDEWEB)

    Anfinsen, Ole-Gunnar

    1999-07-01

    The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks

  18. Impact of burning oil as auxiliary fuel in kraft recovery furnaces upon SO2 emissions

    International Nuclear Information System (INIS)

    Someshwar, A.V.; Caron, A.L.; Pinkerton, J.E.

    1990-01-01

    The relationship between burning medium sulfur oil as auxiliary fuel in kraft recovery furnaces and SO 2 emissions was examined. Analysis of long-term CEMS SO 2 data from four furnaces shows no increase in SO 2 emissions as a result of oil burning. The results of field tests conducted at four furnaces while co-firing oil with liquor (up to 34% of total heat input) show that (1) average SO 2 emissions during the oil firing period either decreased or remained unchanged; (2) the overall sulfur retention within the furnace remained consistently high (more than 90%) with increasing levels of oil burning; (3) apportioning stack SO 2 emissions between those derived from oil and black liquor was infeasible. The results indicate that the same alkali fume generation processes that lead to the efficient capture of SO 2 resulting from black liquor combustion may be responsible for the capture of SO 2 resulting from sulfur-containing oil combustion

  19. MTX [Microwave Tokamak Experiment] diagnostic and auxiliary systems for confinement, transport, and plasma physics studies

    International Nuclear Information System (INIS)

    Hooper, E.B.; Allen, S.L.; Casper, T.A.; Thomassen, K.I.

    1989-01-01

    This note describes the diagnostics and auxiliary systems on the Microwave Tokamak Experiment (MTX) for confinement, transport, and other plasma physics studies. It is intended as a reference on the installed and planned hardware on the machine for those who need more familiarity with this equipment. Combined with the tokamak itself, these systems define the opportunities and capabilities for experiments in the MTX facility. We also illustrate how these instruments and equipment are to be used in carrying out the MTX Operations Plan. Near term goals for MTX are focussed on the absorption and heating by the microwave beam from the FEL, but the Plan also includes using the facility to study fundamental phenomena in the plasma, to control MHD activity, and to drive current noninductively

  20. 47 CFR 74.601 - Classes of TV broadcast auxiliary stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Classes of TV broadcast auxiliary stations. 74... Television Broadcast Auxiliary Stations § 74.601 Classes of TV broadcast auxiliary stations. (a) TV pickup stations. A land mobile station used for the transmission of TV program material and related communications...

  1. BE, DO, and Modal Auxiliaries of 3-Year-Old African American English Speakers

    Science.gov (United States)

    Newkirk-Turner, Brandi L.; Oetting, Janna B.; Stockman, Ida J.

    2014-01-01

    Purpose: This study examined African American English--speaking children's use of BE, DO, and modal auxiliaries. Method: The data were based on language samples obtained from 48 three-year-olds. Analyses examined rates of marking by auxiliary type, auxiliary surface form, succeeding element, and syntactic construction and by a number of child…

  2. 30 CFR 57.22209 - Auxiliary fans (I-C mines).

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans (I-C mines). 57.22209 Section 57... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22209 Auxiliary fans (I-C mines). Electric auxiliary fans shall be approved by MSHA under the applicable requirements of 30 CFR part 18...

  3. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the applicable...

  4. Role of regional radiofrequency hyperthermia after hepatic artery block in the normal pit liver

    International Nuclear Information System (INIS)

    Luo Jingwei; Xu Guozhen; Xiong Jinghong; Liu Xiaoyun; Wang Weihu; Li Yexiong

    2003-01-01

    Objective: To study the temperature difference, tolerated high temperature, pathological changes between normal and blocked hepatic artery in radiofrequency hyperthermia for pig liver. Methods: Mature pig was used with iodine blocked right hepatic artery. Heat of the whole liver was given for 1 hour by SR-1000 radiofrequency hyperthermia with four thermocouple probes to measure the temperature of the right hepatic artery, right and left normal liver and rectum. Results: Temperature of blocked right liver increased by 10.2 degree C from 39.1 degree C to 49.3 degree C as compared with the left liver of which the temperature rose by 6.8 degree C from 39.7 degree C to 46.5 degree C but the temperature of right hepatic artery and rectum rose only by 3.3 degree C, 3.2 degree C respectively. After sacrificing the pig one week later, on lobe exploration, severe necrosis was observed in the right lobe but the left lobe was normal with a clear demarcation between the two lobes. Conclusions: Hepatic arterial iodine embolization potentiates radiofrequency hyperthermia in the liver. Liver with blocked artery showed conspicuous necrosis but liver with normal un-blocked artery was able to tolerate 46.5 degree C. This provides some evidence for the combination of regional hyperthermia and hepatic artery block in the treatment of advanced liver cancer

  5. Radiofrequency therapy in back pain and complex regional pain syndrome (CRPS

    Directory of Open Access Journals (Sweden)

    Norina Bergamin

    2011-01-01

    Full Text Available Percutaneous radiofrequency procedures are frequently used in the management of chronic pain. Continuous radiofrequency (CRF has been established as a safe and effective treatment for pain originating from facet and sacroiliac joints by way of co-agulation of their nerve supply. Different methods have been proposed to account for the complex nerve supply of the sacroiliac joint. Due to its neurodestructive property, CRF was limited to the treatment of neuropathic pain. When applied to the dorsal root ganglion (DRG for spinal pain or to the sympathetic ganglia in treatment of CRPS, heat related side effects have been reported. With the development of pulsed radiofrequency (PRF, a less destructive alternative to CRF became available, that is more suitable to treat neuropathic pain. PRF was adopted in the treatment of several pain conditions with different success. The results with PRF adjacent to the DRG are promising, whereas for facet and sacroiliac joint pain PRF could not yet be proven equally effective as CRF. As for PRF in CRPS there is almost no evidence available. The potential of PRF seems to lie in those areas where CRF is of limited value. Con-versely, it is questionable if PRF will ever be equally effective in indications, where CRF is already well established. Despite its active use in clinical practice, PRF is not validated yet nor is its mode of action. The literature in both cases is accumulating but further studies are urgently needed.

  6. Radiofrequency thermocoagulation for the treatment of lumbar intervertebral disc protrusion: a clinical observation of 30 cases

    International Nuclear Information System (INIS)

    Gong Weidong; Li Yazhou; Cao Wei; Yang Wei; Zhang Peng; Wang Zhimin; Wu Zhiqun

    2010-01-01

    Objective: To observe the clinical effects and safety of radiofrequency thermocoagulation in treating the lumbar intervertebral disc protrusion. Methods: Thirty patients with lumbar intervertebral disc protrusion, whose diagnoses were confirmed by clinical manifestations and CT findings, were involved in this study. The needle was punctured to the target point of the diseased intervertebral space under C-arm fluoroscopic guidance. After the testing of sensory nerve, motor nerve and temperature was made, the target needles were heated until the nerve radiofrequency temperature meter reached the point of 92 degree C. This point of temperature was held for 100 seconds and the procedure was repeated for four cycles. Results: Six months after the treatment, all patients showed an obvious improvement in VAS, which decreased from 7.83 ± 0.33 before operation to 2.37 ± 0.48 after treatment (P < 0.05). According to the modified Macnab therapeutic evaluation criteria, excellent result was seen in 9, good result in 12, fair result in 5 and poor result in 4 cases, with a total effective rate of 86.7%. No serious complications occurred in all patients. Conclusion: Radiofrequency thermocoagulation is an effective and safe method for the treatment of lumbar intervertebral disc protrusion. (authors)

  7. Mathematical 3D modelling and sensitivity analysis of multipolar radiofrequency ablation in the spine.

    Science.gov (United States)

    Matschek, Janine; Bullinger, Eric; von Haeseler, Friedrich; Skalej, Martin; Findeisen, Rolf

    2017-02-01

    Radiofrequency ablation is a valuable tool in the treatment of many diseases, especially cancer. However, controlled heating up to apoptosis of the desired target tissue in complex situations, e.g. in the spine, is challenging and requires experienced interventionalists. For such challenging situations a mathematical model of radiofrequency ablation allows to understand, improve and optimise the outcome of the medical therapy. The main contribution of this work is the derivation of a tailored, yet expandable mathematical model, for the simulation, analysis, planning and control of radiofrequency ablation in complex situations. The dynamic model consists of partial differential equations that describe the potential and temperature distribution during intervention. To account for multipolar operation, time-dependent boundary conditions are introduced. Spatially distributed parameters, like tissue conductivity and blood perfusion, allow to describe the complex 3D environment representing diverse involved tissue types in the spine. To identify the key parameters affecting the prediction quality of the model, the influence of the parameters on the temperature distribution is investigated via a sensitivity analysis. Simulations underpin the quality of the derived model and the analysis approach. The proposed modelling and analysis schemes set the basis for intervention planning, state- and parameter estimation, and control. Copyright © 2016. Published by Elsevier Inc.

  8. Performance of a Solar Heating System with Photovoltaic Thermal Hybrid Collectors and Heat Pump

    DEFF Research Database (Denmark)

    Dannemand, Mark; Furbo, Simon; Perers, Bengt

    2017-01-01

    . When the solar collectors are unable to supply the heat demand an auxiliary heat source is used. Heat pumps can generate this heat. Liquid/water heat pumps have better performance than air/water heat pumps in cold climates but requires installation of a tubing system for the cold side of the heat pump....... The tubes are typically placed in the ground, requires a significant land area and increase the installation cost. A new system design of a solar heating system with two storage tanks and a liquid/water heat pump is presented. The system consists of PVT collectors that generate both heat and electricity......The energy consumption in buildings accounts for a large part of the World’s CO2 emissions. Much energy is used for appliances, domestic hot water preparation and space heating. In solar heating systems, heat is captured by solar collectors when the sun is shining and used for heating purposes...

  9. Randomized Sham-controlled Double-Blind Multicenter Clinical Trial to Ascertain the Effect of Percutaneous Radiofrequency Treatment for Sacroiliac Joint Pain: Three-month Results

    NARCIS (Netherlands)

    C.W.J. van Tilburg (Cornelis); F.A. Schuurmans (Fleur A.); D.L. Stronks (Dirk); J.G. Groeneweg (George); F.J.P.M. Huygen

    2016-01-01

    markdownabstractObjectives: To investigate the effect of a percutaneous radiofrequency (RF) heat lesion compared with a sham procedure, applied to the lateral branches of L5, S1, S2, S3, and S4 nerve roots. Materials and Methods: Sixty patients aged 18 years and above with a medical history and

  10. Endovascular Radiofrequency Ablation for Varicose Veins

    Science.gov (United States)

    2011-01-01

    treatment plan. The RFA procedure involves the introduction of a guide wire into the target vein under ultrasound guidance followed by the insertion of an introducer sheath through which the RFA catheter is advanced. Once satisfactory positioning has been confirmed with ultrasound, a tumescent anaesthetic solution is injected into the soft tissue surrounding the target vein along its entire length. This serves to anaesthetize the vein, insulate the heat from damaging adjacent structures, including nerves and skin and compresses the vein increasing optimal contact of the vessel wall with the electrodes or expanded prongs of the RF device. The RF generator is then activated and the catheter is slowly pulled along the length of the vein. At the end of the procedure, hemostasis is then achieved by applying pressure to the vein entry point. Adequate and proper compression stockings and bandages are applied after the procedure to reduce the risk of venous thromboembolism and to reduce postoperative bruising and tenderness. Patients are encouraged to walk immediately after the procedure. Follow-up protocols vary, with most patients returning 1 to 3 weeks later for an initial follow-up visit. At this point, the initial clinical result is assessed and occlusion of the treated vessels is confirmed with ultrasound. Patients often have a second follow-up visit 1 to 3 months following RFA at which time clinical evaluation and ultrasound are repeated. If required, additional procedures such as phlebectomy or sclerotherapy may be performed during the RFA procedure or at any follow-up visits. Regulatory Status The Closure System® radiofrequency generator for endovascular thermal ablation of varicose veins was approved by Health Canada as a class 3 device in March 2005, registered under medical device license 67865. The RFA intravascular catheter was approved by Health Canada in November 2007 for the ClosureFast catheter, registered under medical device license 16574. The Closure System

  11. Versatile Auxiliary Orthodontic Spring for Orthodontic Correction of Impacted Teeth

    Directory of Open Access Journals (Sweden)

    Pavankumar Janardan Vibhute

    2011-01-01

    Full Text Available Malocclusion such as impacted tooth is not uncommon. Many approaches with various auxiliary springs have been reported in literature till date for correction of such malocclusions. They had biomechanical, retentive and stability drawbacks inherent in their designs. This article presents the innovative approach for orthodontic correction of impacted tooth, especially with light force appliance, i.e. Begg′s appliance, where round wires in round molar tubes are used throughout treatment. A versatile auxiliary orthodontic spring (VAOS is fabricated in the 0.018 inch Australian stainless steel round wire, which may be anchored on round molar buccal tube, and desirable force vector may be applied in any of the three dimensions. Fabrication and its clinical application are discussed.

  12. Vanishing auxiliary variables in PPS sampling - with applications in microscopy

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute; Jensen, Eva B. Vedel

    Recently, non-uniform sampling has been suggested in microscopy to increase efficiency. More precisely, sampling proportional to size (PPS) has been introduced where the probability of sampling a unit in the population is proportional to the value of an auxiliary variable. Unfortunately, vanishing...... auxiliary variables are a common phenomenon in microscopy and, accordingly, part of the population is not accessible, using PPS sampling. We propose a modification of the design, for which an optimal solution can be found, using a model assisted approach. The optimal design has independent interest...... in sampling theory. We verify robustness of the new approach by numerical results, and we use real data to illustrate the applicability....

  13. Renormalization of supersymmetric models without using auxiliary fields

    International Nuclear Information System (INIS)

    Urbanek, P.

    1986-01-01

    Previously a linear representation of supersymmetry (Ss) was used in investigations of renormalizability. There auxiliary fields have been introduced in order that the Ss-algebra closes 'off-shell'. When the auxiliary fields are eliminated by their equations of motion, the Ss representation becomes nonlinear and Ss closes only 'on-shell'. Following O.Piguet and K.Sibold 1984 Ss is expressed through Ward identities which are formulated as functional variations of the generating functional of the Green functions. These functional operators form a closed algebra, a fact essential for the proof of renormalizability, which is given. It is not necessary to use a specific subtraction scheme in the Green functions. The procedure is applied to the Wess-Zumino model and the supersymmetric extension of the quantum electrodynamics. 15 refs. (qui)

  14. Aging assessment of PWR [Pressurized Water Reactor] Auxiliary Feedwater Systems

    International Nuclear Information System (INIS)

    Casada, D.A.

    1988-01-01

    In support of the Nuclear Regulatory Commission's Nuclear Plant Aging Research (NPAR) Program, Oak Ridge National Laboratory is conducting a review of Pressurized Water Reactor Auxiliary Feedwater Systems. Two of the objectives of the NPAR Program are to identify failure modes and causes and identify methods to detect and track degradation. In Phase I of the Auxiliary Feedwater System study, a detailed review of system design and operating and surveillance practices at a reference plant is being conducted to determine failure modes and to provide an indication of the ability of current monitoring methods to detect system degradation. The extent to which current practices are contributing to aging and service wear related degradation is also being assessed. This paper provides a description of the study approach, examples of results, and some interim observations and conclusions. 1 fig., 1 tab

  15. Component Data Base for Space Station Resistojet Auxiliary Propulsion

    Science.gov (United States)

    Bader, Clayton H.

    1988-01-01

    The resistojet was baselined for Space Station auxiliary propulsion because of its operational versatility, efficiency, and durability. This report was conceived as a guide to designers and planners of the Space Station auxiliary propulsion system. It is directed to the low thrust resistojet concept, though it should have application to other station concepts or systems such as the Environmental Control and Life Support System (ECLSS), Manufacturing and Technology Laboratory (MTL), and the Waste Fluid Management System (WFMS). The information will likely be quite useful in the same capacity for other non-Space Station systems including satellite, freeflyers, explorers, and maneuvering vehicles. The report is a catalog of the most useful information for the most significant feed system components and is organized for the greatest convenience of the user.

  16. Theory of energy level and its application in water-loop heat pump system

    International Nuclear Information System (INIS)

    Yu, Qi Dong

    2017-01-01

    Highlights: • Novel theory of saving energy and its application in water loop heat pump. • Reverse energy caused by units to water loop and its solution. • New method for determining the energy-saving range of water loop heat pump. • Capacity model of auxiliary heat source and its size for all building types. • Advice for reducing total energy consumption of water loop heat pump. - Abstract: It is a difficult problem to how to determine the reverse energy caused by units to water loop when a water-loop heat pump (WLHP) is in cooling and heating simultaneous mode, which not only has a great impact on energy-saving rate but also decides the use of auxiliary heat source in winter. This paper presents a theory of energy level to improve the research on WLHP system by using the relationship among building, circulating water and units. In this theory, the circulating water replaces building load as a new method to convert the reverse energy into energy change of circulating water and the equation of energy level also is built to determine the energy-saving range of WLHP system and report the capacity model of auxiliary heat source for all building types. An office building with different auxiliary powers is tested to analyze system operation characteristic and the effect of auxiliary heat source on unit and system and the results validate previous conclusions and suggest that an energy balance should be considered between units and auxiliary power to improve overall operation.

  17. CRBRP decay heat removal systems

    International Nuclear Information System (INIS)

    Hottel, R.E.; Louison, R.; Boardman, C.E.; Kiley, M.J.

    1977-01-01

    The Decay Heat Removal Systems for the Clinch River Breeder Reactor Plant (CRBRP) are designed to adequately remove sensible and decay heat from the reactor following normal shutdown, operational occurrences, and postulated accidents on both a short term and a long term basis. The Decay Heat Removal Systems are composed of the Main Heat Transport System, the Main Condenser and Feedwater System, the Steam Generator Auxiliary Heat Removal System (SGAHRS), and the Direct Heat Removal Service (DHRS). The overall design of the CRBRP Decay Heat Removal Systems and the operation under normal and off-normal conditions is examined. The redundancies of the system design, such as the four decay heat removal paths, the emergency diesel power supplies, and the auxiliary feedwater pumps, and the diversities of the design such as forced circulation/natural circulation and AC Power/DC Power are presented. In addition to overall design and system capabilities, the detailed designs for the Protected Air Cooled Condensers (PACC) and the Air Blast Heat Exchangers (ABHX) are presented

  18. Auxiliary representations of Lie algebras and the BRST constructions

    International Nuclear Information System (INIS)

    Burdik, C.; Pashnev, A.I.; Tsulaya, M.M.

    2000-01-01

    The method of construction of auxiliary representations for a given Lie algebra is discussed in the framework of the BRST approach. The corresponding BRST charge turns out to be nonhermitian. This problem is solved by the introduction of the additional kernel operator in the definition of the scalar product in the Fock space. The existence of the kernel operator is proved for any Lie algebra

  19. Surgical nurse: his leadership style with nursing auxiliary personnel

    OpenAIRE

    Galvão, Cristina Maria; Trevizan, Maria Auxiliadora; Okino Sawada, Namie

    2008-01-01

    This investigation as carried out in order to promote follow-up in the studies concerning nurse`s leadership in the hospital context. Emphasys is given to the nurses that works in surgical ward unities. As a theoretical framework, authors utilized the model of leadership proposed by Hersey na Blanchard, named Situational Leadership. The objective was to analyze the correspondence of opinion between nurses and nursing auxiliary personnel about the leadership style of nurse should adopt in acco...

  20. Restarting Automata with Auxiliary Symbols and Small Lookahead

    DEFF Research Database (Denmark)

    Schluter, Natalie Elaine

    2012-01-01

    We present a study on lookahead hierarchies for restarting automata with auxiliary symbols and small lookahead. In particular, we show that there are just two different classes of languages recognised by RRWW automata, through the restriction of lookahead size. We also show that the respective...... (left-) monotone restarting automaton models characterise the context-free languages and that the respective right-left-monotone restarting automata characterise the linear languages both with just lookahead length 2....

  1. Tube Model Predictive Control with an Auxiliary Sliding Mode Controller

    Directory of Open Access Journals (Sweden)

    Miodrag Spasic

    2016-07-01

    Full Text Available This paper studies Tube Model Predictive Control (MPC with a Sliding Mode Controller (SMC as an auxiliary controller. It is shown how to calculate the tube widths under SMC control, and thus how much the constraints of the nominal MPC have to be tightened in order to achieve robust stability and constraint fulfillment. The analysis avoids the assumption of infinitely fast switching in the SMC controller.

  2. Exact fluctuations of nonequilibrium steady states from approximate auxiliary dynamics

    OpenAIRE

    Ray, Ushnish; Chan, Garnet Kin-Lic; Limmer, David T.

    2017-01-01

    We describe a framework to significantly reduce the computational effort to evaluate large deviation functions of time integrated observables within nonequilibrium steady states. We do this by incorporating an auxiliary dynamics into trajectory based Monte Carlo calculations, through a transformation of the system's propagator using an approximate guiding function. This procedure importance samples the trajectories that most contribute to the large deviation function, mitigating the exponenti...

  3. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling.

    Science.gov (United States)

    Aerts, Sam; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-01

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information-inside hotspots or in search of them-based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km2. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. Copyright © 2013 Elsevier Inc. All rights

  4. Bayesian Analysis of Geostatistical Models With an Auxiliary Lattice

    KAUST Repository

    Park, Jincheol

    2012-04-01

    The Gaussian geostatistical model has been widely used for modeling spatial data. However, this model suffers from a severe difficulty in computation: it requires users to invert a large covariance matrix. This is infeasible when the number of observations is large. In this article, we propose an auxiliary lattice-based approach for tackling this difficulty. By introducing an auxiliary lattice to the space of observations and defining a Gaussian Markov random field on the auxiliary lattice, our model completely avoids the requirement of matrix inversion. It is remarkable that the computational complexity of our method is only O(n), where n is the number of observations. Hence, our method can be applied to very large datasets with reasonable computational (CPU) times. The numerical results indicate that our model can approximate Gaussian random fields very well in terms of predictions, even for those with long correlation lengths. For real data examples, our model can generally outperform conventional Gaussian random field models in both prediction errors and CPU times. Supplemental materials for the article are available online. © 2012 American Statistical Association, Institute of Mathematical Statistics, and Interface Foundation of North America.

  5. Auxiliary/Master microprocessor CAMAC Crate Controller applications

    International Nuclear Information System (INIS)

    Barsotti, E.

    1975-01-01

    The need for further sophistication of an already complex serial CAMAC control system at Fermilab led to the development of an Auxilary/Master CAMAC Crate Controller. The controller contains a Motorola 6800 microprocessor, 2K bytes of RAM, and 8K bytes of PROM memory. Bussed dataway lines are time shared with CAMAC signals to provide memory expansion and direct addressing of peripheral devices without the need of external cabling. The Auxiliary/Master Crate Controller (A/MCC) can function as either a Master, i.e., stand alone, crate controller or as an Auxiliary controller to Fermilab's Serial Crate Controller (SCC). Two modules, one single- and one double-width, make up an A/MCC. The microprocessor has one nonmaskable and one maskable vectored interrupt. Time sharing the dataway between SCC programmed and block transfer generated dataway cycles and A/MCC operations still allows a 99 percent microprocessor CPU busy time. Since the conception of the A/MCC, there has been an increasing number of control system-related projects proposed which would not have been possible or would have been very difficult to implement without such a device. The first such application now in use at Fermilab is a stand-alone control system for a mass spectrometer experiment in the Main Ring Internal Target Area. This application in addition to other proposed A/MCC applications, both stand-alone and auxiliary, is discussed

  6. Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

  7. ADAPTIVE SELECTION OF AUXILIARY OBJECTIVES IN MULTIOBJECTIVE EVOLUTIONARY ALGORITHMS

    Directory of Open Access Journals (Sweden)

    I. A. Petrova

    2016-05-01

    Full Text Available Subject of Research.We propose to modify the EA+RL method, which increases efficiency of evolutionary algorithms by means of auxiliary objectives. The proposed modification is compared to the existing objective selection methods on the example of travelling salesman problem. Method. In the EA+RL method a reinforcement learning algorithm is used to select an objective – the target objective or one of the auxiliary objectives – at each iteration of the single-objective evolutionary algorithm.The proposed modification of the EA+RL method adopts this approach for the usage with a multiobjective evolutionary algorithm. As opposed to theEA+RL method, in this modification one of the auxiliary objectives is selected by reinforcement learning and optimized together with the target objective at each step of the multiobjective evolutionary algorithm. Main Results.The proposed modification of the EA+RL method was compared to the existing objective selection methods on the example of travelling salesman problem. In the EA+RL method and its proposed modification reinforcement learning algorithms for stationary and non-stationary environment were used. The proposed modification of the EA+RL method applied with reinforcement learning for non-stationary environment outperformed the considered objective selection algorithms on the most problem instances. Practical Significance. The proposed approach increases efficiency of evolutionary algorithms, which may be used for solving discrete NP-hard optimization problems. They are, in particular, combinatorial path search problems and scheduling problems.

  8. Effect of radiofrequency on capacitance of low density plasma sheath

    International Nuclear Information System (INIS)

    Carneiro, L.T.; Cunha Rapozo, C. da

    1988-01-01

    It is shown that the influence of induced radiofrequency potential (V RF ) modifies the Bohm theory on ion saturation current, measured with Langmuir probes. The effect of radiofrequency potential on diode type plasma sheath resonance is also investigated. (M.C.K.)

  9. 77 FR 43535 - Grantee Codes for Certified Radiofrequency Equipment

    Science.gov (United States)

    2012-07-25

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 2 [FCC 12-60] Grantee Codes for Certified Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: This document... authorization program for radiofrequency (RF) devices under part 2 of its rules. This program is one of the...

  10. CT-guided radiofrequency tumor ablation in children

    International Nuclear Information System (INIS)

    Botsa, Evanthia; Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas; Koutsogiannis, Ioannis; Ziakas, Panayiotis D.; Alexopoulou, Efthimia

    2014-01-01

    Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

  11. Level of Radiofrequency (RF) Radiations from GSM Base Stations ...

    African Journals Online (AJOL)

    Levels of radiofrequency radiations around two global systems for mobile communication (GSM) base stations located in the vicinity of a residential quarter and workplace complex were measured. The effects of the radiofrequency radiations on albino mice placed in exposure cages and located around the base stations ...

  12. Mechanisms for enlarging lesion size during irrigated tip radiofrequency ablation

    DEFF Research Database (Denmark)

    Petersen, Helen Høgh; Roman-Gonzalez, Javier; Johnson, Susan B

    2004-01-01

    INTRODUCTION: Irrigated tip radiofrequency ablation of cardiac arrhythmias was developed to increase the size of the radiofrequency-induced lesion, since cooling of the electrode tip allows use of higher power settings. The purpose of this study was to determine if the increased lesion size during...

  13. Occupational exposure to radiofrequency fields in antenna towers

    International Nuclear Information System (INIS)

    Alanko, T.; Hietanen, M.

    2007-01-01

    Exposure of workers to radiofrequency fields was assessed in two medium-sized antenna towers. Towers had transmitting antennas from different networks, e.g. mobile phone networks, radio and digital TV sub-stations and amateur radio. The levels of radiofrequency fields were measured close to the ladders of the towers. All measured values were below ICNIRP occupational reference levels. (authors)

  14. CT-guided radiofrequency tumor ablation in children

    Energy Technology Data Exchange (ETDEWEB)

    Botsa, Evanthia [National and Kapodistrian University of Athens, First Pediatric Clinic, Agia Sofia Children' s Hospital, Athens (Greece); Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas [Sotiria General Hospital for Chest Diseases, Department of Medical Imaging and Interventional Radiology, Athens (Greece); Koutsogiannis, Ioannis [General Military Hospital NIMTS, Department of Medical Imaging, Athens (Greece); Ziakas, Panayiotis D. [Warren Alpert Medical School of Brown University Rhode Island Hospital, Division of Infectious Diseases, Providence, RI (United States); Alexopoulou, Efthimia [Attikon University Hospital, Second Department of Radiology, Athens University School of Medicine, Athens (Greece)

    2014-11-15

    Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

  15. Comparative Study of Electric Energy Storages and Thermal Energy Auxiliaries for Improving Wind Power Integration in the Cogeneration System

    Directory of Open Access Journals (Sweden)

    Yanjuan Yu

    2018-01-01

    Full Text Available In regards to the cogeneration system in Northern China, mainly supported by combined heat and power (CHP plants, it usually offers limited operation flexibility due to the joint production of electric and thermal power. For that large-scale wind farms included in the cogeneration system, a large amount of wind energy may have to be wasted. To solve this issue, the utilization of the electric energy storages and the thermal energy auxiliaries are recommended, including pumped hydro storage (PHS, compressed air energy storage (CAES, hydrogen-based energy storage (HES, heat storage (HS, electric boilers (EB, and heat pumps (HP. This paper proposes a general evaluation method to compare the performance of these six different approaches for promoting wind power integration. In consideration of saving coal consumption, reducing CO2 emissions, and increasing investment cost, the comprehensive benefit is defined as the evaluation index. Specifically, a wind-thermal conflicting expression (WTCE is put forward to simplify the formulation of the comprehensive benefit. Further, according to the cogeneration system of the West Inner Mongolia (WIM power grid, a test system is modelled to perform the comparison of the six different approaches. The results show that introducing the electric energy storages and the thermal energy auxiliaries can both contribute to facilitating wind power integration, and the HP can provide the best comprehensive benefit.

  16. Analysis of public perception of increased radiofrequency exposure from mobile phone in Southwestern Nigeria

    International Nuclear Information System (INIS)

    Oladapo, O.O.; Ishola, G.A.; Ayokunnnu, D.O.

    2011-01-01

    Wireless communication devices have been increasingly used recently in Nigeria with a corresponding public perception of increase in radiofrequency (RF) radiation. This perception has developed into public concerns, thus requiring verification. For the purpose of verification, a survey in form of an opinion poll was conducted by means of an interview using questionnaires. The survey shows that people actually experienced symptoms like headache, fatigue, dizziness, and heat sensation. However, out of the respondents that have experienced one symptoms or the other, 84% still believe it is safe to use mobile phones. Only 4 % of those that claimed they experienced symptoms had consulted a doctor in connection with the symptoms.

  17. Intraoperative radio-frequency capacitive hyperthermia and radiation therapy for unresectable pancreatic cancer

    International Nuclear Information System (INIS)

    Nakazawa, M.; Yamashita, T.; Hashida, I.

    1988-01-01

    The authors have initiated intraoperative radiation therapy (IORT) and intraoperative radio-frequency capacitive hyperthermia (IOHT) for unresectable pancreatic cancer. After gastric (corpus) resection, IORT and IOHT were conducted and gastro-duodenostomy was performed IORT was delivered with 12 meV electron (25 Gy) and 10 MV Linac x-ray (7.5 Gy). IOHT was done with 13.56 MHz capacitive equipment aiming 43 0 C for over 30 min along with concurrent administration of 500 mg 5-FU. Five cases were heated by the conventional method and two additional cases were heated with a newly fabricated applicator. Attained temperatures monitored directly from tumor were 38.5 0 C-44.3 0 C (over 43 0 C in four cases, 40 0 C in one case, and below 40 0 C in two cass.) Pain relief was achieved in most cases. Using the new applicators, the authors could avoid unexpected hot spots and insufficient heating

  18. Active stabilization of ion trap radiofrequency potentials

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K. G.; Wong-Campos, J. D.; Restelli, A.; Landsman, K. A.; Neyenhuis, B.; Mizrahi, J.; Monroe, C. [Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742 (United States)

    2016-05-15

    We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.

  19. Ion transmission in a linear radiofrequency spectrometer

    International Nuclear Information System (INIS)

    Gomet, J.-C.

    1975-01-01

    A linear radiofrequency spectrometer is used for the purpose of experimental determination of the absolute ionization cross sections of various ions obtained by electron impact on polyatomic molecules. The transmission of the apparatus is studied: it does not only depend on the mass resolution of the spectrometer, but also on the nature of ions. It is affected by charge transfers, especially for the parent ions. An empiric way of correction of the apparatus function is given which allows the use at 10 -6 Torr [fr

  20. Radiofrequency Energy and Electrode Proximity Influences Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation Lesion Size: An In Vitro Study with Clinical Correlation.

    Science.gov (United States)

    Staudt, Michael D; Maturu, Sarita; Miller, Jonathan P

    2018-02-16

    Radiofrequency thermocoagulation of epileptogenic foci via stereoelectroencephalography (SEEG) electrodes has been suggested as a treatment for medically intractable epilepsy, but reported outcomes have been suboptimal, possibly because lesions generated using conventional high-energy radiofrequency parameters are relatively small. To describe a technique of delivering low energy across separate SEEG electrodes in order to create large confluent radiofrequency lesions. The size and configuration of radiofrequency lesions using different radiofrequency intensity and interelectrode distance was assessed in egg whites. Magnetic resonance images (MRI) from 3 patients who had undergone radiofrequency lesion creation were evaluated to determine the contribution of lesion intensity and electrode separation on lesion size. Electroencephalography, MRI, and clinical data were assessed before and after lesion creation. Both in Vitro and in Vivo analysis revealed that less energy paradoxically produced larger lesions, with the largest possible lesions produced when radiofrequency power was applied for long duration at less than 3 W. Linear separation of electrodes also contributed to lesion size, with largest lesions produced when electrodes were separated by a linear distance of between 5 and 12 mm. Clinical lesions produced using these parameters were large and resulted in improvement in interictal and ictal activity. Radiofrequency lesions produced using low-energy delivery between SEEG electrodes in close proximity can produce a large lesion. These findings might have advantages for treatment of focal epilepsy.

  1. S-matrix for the theories that admit closure of the algebra with the aid of auxiliary fields. Auxiliary fields in supergravity. [Word identities

    Energy Technology Data Exchange (ETDEWEB)

    Fradkin, E S; Vasiliev, M A [AN SSSR, Moscow. Fizicheskij Inst.

    1978-08-19

    A minimal set of auxiliary fields (scalarpseudoscalar and pseudovector) providing the closed algebra in supergravity is constructed. A compact scheme for the generating functional with closed gauge algebra is proposed. The S-matrix and the Ward identities for arbitrary theory that admits the closing of the algebra by introducing auxiliary fields is obtained.

  2. 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.

  3. Radiofrequency ablation of hepatocellular carcinoma: pros and cons.

    Science.gov (United States)

    Rhim, Hyunchul; Lim, Hyo K

    2010-09-01

    Among locoregional treatments for hepatocellular carcinoma (HCC), radiofrequency ablation (RFA) has been accepted as the most popular alternative to curative transplantation or resection, and it shows an excellent local tumor control rate and acceptable morbidity. The benefits of RFA have been universally validated by the practice guidelines of international societies of hepatology. The main advantages of RFA include 1) it is minimally invasive with acceptable morbidity, 2) it enables excellent local tumor control, 3) it has promising long-term survival, and 4) it is a multimodal approach. Based on these pros, RFA will play an important role in managing the patient with early HCC (smaller than 3 cm with fewer than four tumors). The main limitations of current RFA technology in hepatic ablation include 1) limitation of ablation volume, 2) technically infeasible in some tumors due to conspicuity and dangerous location, and 3) the heat-sink effect. Many technical approaches have been introduced to overcome those limitations, including a novel guiding modality, use of artificial fluid or air, and combined treatment strategies. RFA will continue to play a role as a representative ablative modality in the management of HCC, even in the era of targeted agents.

  4. Radiofrequency-dressed-state potentials for neutral atoms

    DEFF Research Database (Denmark)

    Hofferberth, S.; Lesanovsky, Igor; Fischer, B.

    2006-01-01

    Potentials for atoms can be created by external fields acting on properties such as magnetic moment, charge, polarizability, or by oscillating fields that couple internal states. The most prominent realization of the latter is the optical dipole potential formed by coupling ground and electronica......Potentials for atoms can be created by external fields acting on properties such as magnetic moment, charge, polarizability, or by oscillating fields that couple internal states. The most prominent realization of the latter is the optical dipole potential formed by coupling ground...... and electronically excited states of an atom with light. Here, we present an extensive experimental analysis of potentials derived from radiofrequency (RF) coupling of electronic ground states. The coupling is magnetic and the vector character allows the design of versatile microscopic state-dependent potential...... landscapes. Compared with standard magnetic trapping, we find no additional heating or (collisional) loss up to densities of 1015 atoms cm-3. We demonstrate robust evaporative cooling in RF potentials, which allows easy production of Bose-Einstein condensates in complex potentials. Altogether, this makes RF...

  5. Percutaneous radiofrequency ablation of osteoid osteomas. Technique and results

    International Nuclear Information System (INIS)

    Bruners, P.; Penzkofer, T.; Guenther, R. W.; Mahnken, A.

    2009-01-01

    Purpose: Osteoid osteoma is a benign primary bone tumor that typically occurs in children and young adults. Besides local pain, which is often worse at night, prompt relief due to medication with acetylsalicylic acid (ASS) is characteristic for this bone lesion. Because long-term medication with ASS does not represent an alternative treatment strategy due to its potentially severe side effects, different minimally invasive image-guided techniques for the therapy of osteoid osteoma have been developed. In this context radiofrequency (RF) ablation in particular has become part of the clinical routine. The technique and results of image-guided RF ablation are compared to alternative treatment strategies. Materials and Methods: Using this technique, an often needle-shaped RF applicator is percutaneously placed into the tumor under image guidance. Then a high-frequency alternating current is applied by the tip of the applicator which leads to ionic motion within the tissue resulting in local heat development and thus in thermal destruction of the surrounding tissue including the tumor. Results: The published primary and secondary success rates of this technique are 87 and 83%, respectively. Surgical resection and open curettage show comparable success rates but are associated with higher complication rates. In addition image-guided RF ablation of osteoid osteomas is associated with low costs. (orig.)

  6. Liver resection with bipolar radiofrequency device: Habib 4X.

    Science.gov (United States)

    Pai, Madhava; Jiao, Long R; Khorsandi, Shirin; Canelo, Ruben; Spalding, Duncan R C; Habib, Nagy A

    2008-01-01

    Intraoperative blood loss has been shown to be an important factor correlating with morbidity and mortality in liver surgery. In spite of the technological advances in hepatic parenchymal transection devices, bleeding remains the single most important complication of liver surgery. The role of radiofrequency (RF) in liver surgery has been expanded from tumour ablation to major hepatic resections in the last decade. Habib 4X, a new bipolar RF device designed specifically for liver resection is described here. Habib 4X is a bipolar, handheld, disposable RF device and consists of two pairs of opposing electrodes which is introduced perpendicularly into the liver, along the intended transection line. It produces controlled RF energy between the electrodes and the heat produced seals even major biliary and blood vessels and enables resection of the liver parenchyma with a scalpel without blood loss or biliary leak. Three hundred and eleven patients underwent 384 liver resections from January 2002 to October 2007 with this device. There were 109 major resections and none of the patients had vascular inflow occlusion (Pringle's manoeuvre). Mean intraoperative blood loss was 305 ml (range 0-4300) ml, with less than 5% (n=18) rate of transfusion. Habib 4X is an additional device for hepatobiliary surgeons to perform liver resections with minimal blood loss and low morbidity and mortality rates.

  7. Design, construction and test run of a two-tonne capacity solar rice dryer with rice-husk-fired auxiliary heater

    International Nuclear Information System (INIS)

    Iloeje, O.C.; Ekechukwu, O.V.; Ezeike, G.O.I.

    1993-09-01

    The design and construction details of a two-tonne per batch capacity natural-circulation solar rice dryer and the highlights of the design of its rice-husk-fired auxiliary heating system which is still under construction are presented. The dryer measures approximately 17.7m long by 9.8m wide by 6m high. Preliminary results of a test run on the solar dryer section only is reported. (author). 5 refs, 3 figs

  8. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, A. V., E-mail: ave@cardio-tomsk.ru; Evtushenko, V. V. [National Research Tomsk State University, Tomsk (Russian Federation); Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Saushkina, Yu. V.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Smyshlyaev, K. A.; Kurlov, I. O. [Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Lishmanov, Yu. B.; Anfinogenova, Ya. D. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Sergeevichev, D. S. [Academician E.N. Meshalkin State Research Institute of Circulation Pathology, Novosibirsk (Russian Federation); Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V. [National Research Tomsk State University, Tomsk (Russian Federation); Lotkov, A. I. [Institute of Strength Physics and Materials Science of the Siberian Branch of the RAS, Tomsk (Russian Federation); Pokushalov, E. A.

    2015-11-17

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using {sup 123}I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  9. Radiofrequency spark chambers and delay line resonators

    International Nuclear Information System (INIS)

    Sayag, Jacques

    1971-01-01

    According to a suggestion of A. Kastler, a spark chamber was excited by an undamped radiofrequency pulse and tracks about 1 mm wide obtained; the result was interpreted by computation of the coefficients of electronic amplification and partial ambipolar diffusion. This work led us to the construction of a new fast triggering undamped wave-train generator of very high tension (patent taken out by the C.E.A. under the no.: EN 7 134 650 the 27.9.1971). Since this apparatus uses a resonant storage line, its design implied a precise knowledge of high impedance delay lines. The experimental radiofrequency spectra of the input impedance of opened or short-circuited lines were plotted completely and analysed by the circuits theory, new measuring methods were established, dispersion relations accurately checked and the equivalence of the formulas, within the third order, with theses of Debye's Dipolar Absorption demonstrated. General properties of Hilbert's transform were also investigated. From the experimental point of view, the electromagnetic energy storage process was extended to the case of a liquid nitrogen-immersed resonant delay line. The good behavior of the cryogenic experiment, where the main difficulty of icing was overcame by the construction of special electrodes, offers great promise for extrapolation to superconductivity. (author) [fr

  10. A sheath model for arbitrary radiofrequency waveforms

    Science.gov (United States)

    Turner, M. M.; Chabert, Pascal

    2012-10-01

    The sheath is often the most important region of a rf plasma, because discharge impedance, power absorption and ion acceleration are critically affected by the behaviour of the sheath. Consequently, models of the sheath are central to any understanding of the physics of rf plasmas. Lieberman has supplied an analytical model for a radio-frequency sheath driven by a single frequency, but in recent years interest has been increasing in radio-frequency discharges excited by increasingly complex wave forms. There has been limited success in generalizing the Lieberman model in this direction, because of mathematical complexities. So there is essentially no sheath model available to describe many modern experiments. In this paper we present a new analytical sheath model, based on a simpler mathematical framework than that of Lieberman. For the single frequency case, this model yields scaling laws that are identical in form to those of Lieberman, differing only by numerical coefficients close to one. However, the new model may be straightforwardly solved for arbitrary current waveforms, and may be used to derive scaling laws for such complex waveforms. In this paper, we will describe the model and present some illustrative examples.

  11. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-01

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possibly IBW-generated sheared flows

  12. Heating and current drive on NSTX

    Science.gov (United States)

    Wilson, J. R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C. K.; Rogers, J. H.; Schilling, G.

    1997-04-01

    Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (˜45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation.

  13. Heating and current drive on NSTX

    International Nuclear Information System (INIS)

    Wilson, J.R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C.K.; Rogers, J.H.; Schilling, G.

    1997-01-01

    Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (∼45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation. copyright 1997 American Institute of Physics

  14. Image-guided radiofrequency ablation of renal cell carcinoma

    International Nuclear Information System (INIS)

    Boss, Andreas; Clasen, Stephan; Pereira, Philippe L.; Kuczyk, Markus; Schick, Fritz

    2007-01-01

    The incidence of renal cell carcinoma is rising with the increased number of incidental detection of small tumours. During the past few years, percutaneous imaging-guided radiofrequency ablation has evolved as a minimally invasive treatment of small unresectable renal tumours offering reduced patient morbidity and overall health care costs. In radiofrequency ablation, thermal energy is deposited into a targeted tumour by means of a radiofrequency applicator. In recent studies, radiofrequency ablation was shown to be an effective and safe modality for local destruction of renal cell carcinoma. Radiofrequency applicator navigation can be performed via ultrasound, computed tomography or magnetic resonance guidance; however, ultrasound seems less favourable because of the absence of monitoring capabilities during ablation. On-line monitoring of treatment outcome can only be performed with magnetic resonance imaging giving the possibility of eventual applicator repositioning to ablate visible residual tumour tissue. Long-term follow-up is crucial to assess completeness of tumour ablation. New developments in ablation technology and radiological equipment will further increase the indication field for radiofrequency ablation of renal cell carcinoma. Altogether, radiofrequency ablation seems to be a promising new modality for the minimally invasive treatment of renal cell carcinoma, which was demonstrated to exhibit high short-term effectiveness. (orig.)

  15. Assessment of a potential rapid condensation induced water hammer in a passive auxiliary feedwater system

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Shin, Byung Soo; Do, Kyu Sik [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Moody, Frederick J. [General Electric (Retired), CA (United States)

    2012-10-15

    A passive auxiliary feedwater system (PAFS) which is incorporated in the APR+ system is a kind of closed natural circulation loop. The PAFS has no operating functions during normal plant operation, but it has a dedicated safety function of the residual heat removal following initiating events, including the unlikely event of the most limiting single failure occurring coincident with a loss of offsite power, when the feedwater system becomes inoperable or unavailable. Even in the unlikely event of a station blackout, the isolation valves can be opened either by DC power or manual operation and then the PAFS can also provide adequate condensate to the steam generator (SG). The PAFS piping in the vicinity of each of the two SGs is designed to minimize the potential for destructive water hammer during start up operation by setting the stroke time for full close or full open of the condensate isolation valves upon receipt of a passive auxiliary feedwater actuation signal. The temperature of the stagnant condensate water and its surrounding tubes and piping during the reactor normal operation modes may fall to the ambient temperature. A possible concern is the introduction of saturated steam into the PAFS recirculation pipe downstream of the PCHX in the beginning of the PAFS operation. Although the steam introduction rate is expected to be slow, a rapid condensation rate is expected due to the initial cold surrounding temperature in the pipe, which could result in a localized pressure reduction and the propagation of decompression and velocity disturbances into the condensate water leg, which might cause the sudden closure of check valves and associated water hammer. Thus, it is requisite for the licensing review of the PAFS design to confirm if destructive water hammers will not be produced due to such rapid condensation induced decompressions in the system. This paper addresses an assessment of the potential local decompressions which could result from the steam

  16. Seismic Qualification of Auxiliary Feed Water Control Valve

    International Nuclear Information System (INIS)

    Hwang, K. M.; Jang, J. B.; Kim, J. K.; Suh, Y. P.

    2006-01-01

    Although domestic nuclear power industry has almost accomplished technical independence, Auxiliary Feed Water Control Valve (AFWCV) is still depending on import. In order to jump to advanced nation in nuclear power industry, it is very important to achieve technical independence in designing and manufacturing AFWCV. At last, AFWCV is self-manufactured using the domestic technology under the financial support of the government. Therefore, the seismic qualification is carried out to verify the safety and operability of AFWCV against the earthquake in this study

  17. Sampling general N-body interactions with auxiliary fields

    Science.gov (United States)

    Körber, C.; Berkowitz, E.; Luu, T.

    2017-09-01

    We present a general auxiliary field transformation which generates effective interactions containing all possible N-body contact terms. The strength of the induced terms can analytically be described in terms of general coefficients associated with the transformation and thus are controllable. This transformation provides a novel way for sampling 3- and 4-body (and higher) contact interactions non-perturbatively in lattice quantum Monte Carlo simulations. As a proof of principle, we show that our method reproduces the exact solution for a two-site quantum mechanical problem.

  18. Nuclear Reactor RA Safety Report, Vol. 8, Auxiliary system

    International Nuclear Information System (INIS)

    1986-11-01

    This volume describes RA reactor auxiliary systems, as follows: special ventilation system, special drainage system, hot cells, systems for internal transport. Ventilation system is considered as part of the reactor safety and protection system. Its role is eliminate possible radioactive particles dispersion in the environment. Special drainage system includes pipes and reservoirs with the safety role, meaning absorption or storage of possible radioactive waste water from the reactor building. Hot cells existing in the RA reactor building are designed for production of sealed radioactive sources, including packaging and transport [sr

  19. Sandia Laboratories technical capabilities. Auxiliary capabilities: environmental health information science

    International Nuclear Information System (INIS)

    1975-09-01

    Sandia Laboratories is an engineering laboratory in which research, development, testing, and evaluation capabilities are integrated by program management for the generation of advanced designs. In fulfilling its primary responsibility to ERDA, Sandia Laboratories has acquired extensive research and development capabilities. The purpose of this series of documents is to catalog the many technical capabilities of the Laboratories. After the listing of capabilities, supporting information is provided in the form of highlights, which show applications. This document deals with auxiliary capabilities, in particular, environmental health and information science. (11 figures, 1 table) (RWR)

  20. Exergy performance of different space heating systems: A theoretical study

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    , the effects of floor covering resistance on the whole system performance were studied using two heat sources; a natural gas fired condensing boiler and an air-source heat pump. The heating systems were also compared in terms of auxiliary exergy use for pumps and fans. The low temperature floor heating system......Three space heating systems (floor heating with different floor covering resistances, radiator heating with different working temperatures, warm-air heating with and without heat recovery) were compared using a natural gas fired condensing boiler as the heat source. For the floor heating systems...... performed better than other systems in terms of exergy demand. The use of boiler as a heat source for a low-exergy floor heating system creates a mismatch in the exergy supply and demand. Although an air-source heat pump could be a better heat source, this depends on the origin of the electricity supplied...

  1. Clinical application and developmental trend of radiofrequency ablation technology

    International Nuclear Information System (INIS)

    Chen Dongfeng

    2009-01-01

    For recent two decades, radiofrequency ablation technology has made great progress in the field of the treatment for neoplasm. At the very beginning, radiofrequency ablation was adopted in treating the hepatic carcinoma, and since then it has been gradually practiced in treating malignancies of lung, bone, kidney, breast, prostate and other solid tumors. Statistical report of the year 2008 has indicated that in the aspect of similar therapeutic measures radiofrequency ablation therapy for tumors holds a 9% market share. Moreover, in the coming years the clinical use of this kind of therapy for tumors will be steadily increasing by 13% every year. (authors)

  2. Super high field ohmically heated tokamak operation

    International Nuclear Information System (INIS)

    Cohn, D.R.; Bromberg, L.; Leclaire, R.J.; Potok, R.E.; Jassby, D.L.

    1986-01-01

    The authors discuss a super high field mode of tokamak operation that uses ohmic heating or near ohmic heating to ignition. The super high field mode of operation uses very high values of Β/sup 2/α, where Β is the magnetic field and a is the minor radius (Β/sup 2/α > 100 T/sup 2/m). We analyze copper magnet devices with major radii from 1.7 to 3.0 meters. Minimizing or eliminating the need for auxiliary heating has the potential advantages of reducing uncertainty in extrapolating the energy confinement time of current tokamak devices, and reducing engineering problems associated with large auxiliary heating requirements. It may be possible to heat relatively short pulse, inertially cooled tokamaks to ignition with ohmic power alone. However, there may be advantages in using a very small amount of auxiliary power (less than the ohmic heating power) to boost the ohmic heating and provide a faster start-up, expecially in relatively compact devices

  3. Prototype solar heating and cooling systems including potable hot water

    Science.gov (United States)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  4. Installation package for a solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    Development and installation of two commercial solar heating and hot water systems are reported. The systems consist of the following subsystems: collector, storage, transport, hot water, auxiliary energy and controls. General guidelines are provided which may be utilized in development of detailed installation plans and specifications. In addition, operation, maintenance and repair of a solar heating and hot water system instructions are included.

  5. Aging and low-flow degradation of auxiliary feedwater pumps

    International Nuclear Information System (INIS)

    Adams, M.L.

    1991-01-01

    This paper documents the results of research done under the auspices of the Nuclear Regulatory Commission Nuclear Plant Aging Research Program. It examines the degradation imparted to safety Auxiliary Feedwater System pumps at nuclear plants due to the low flow operation. The Auxiliary Feedwater (AFW) System is normally a stand-by system. As such it is operated most often in the test mode. Since few plants are equipped with full flow test loops, most testing is accomplished at minimum flow conditions in pump by-pass lines. It is the vibration and hydraulic forces generated at low flow conditions that have been shown to be the major causes of AFW pump aging and degradation. The wear can be manifested in a number of ways, such as impeller or diffuser breakage, thrust bearing and/or balance device failure due to excessive loading, cavitation damage on such stage impellers, increase seal leakage or failure, sear injection piping failure, shaft or coupling breakage, and rotating element seizure

  6. On the Auxiliary Status of Dare in Old English

    Directory of Open Access Journals (Sweden)

    Tomaszewska Magdalena

    2014-12-01

    Full Text Available OE *durran ‘dare’ belongs to a group of the so-called preterite-present verbs which developed weak past tense forms replacing the originally strong forms throughout the paradigm. The present study hypothesizes that the potential sources of this development are related to the decay of the subjunctive mood in Old English. Further, this corpus-based study analyses the status of DARE in Old English, with the findings showing that the verb displayed both lexical and auxiliary verb characteristics. These results are juxtaposed and compared with the verb's developments in Middle English. The databases examined are the corpus of The Dictionary of Old English in Electronic Form (A-G and the Innsbruck Computer Archive of Machine-Readable English Texts. In both cases, a search of potential forms was performed on all the files of the corpora, the raw results were then analysed in order to eliminate irrelevant instances (adjectives, nouns, foreign words, etc.. The relevant forms were examined with the aim to check the properties of DARE as a lexical and an auxiliary verb, and compare the findings with Molencki’s (2002, 2005 observations.

  7. VLTI auxiliary telescopes: a full object-oriented approach

    Science.gov (United States)

    Chiozzi, Gianluca; Duhoux, Philippe; Karban, Robert

    2000-06-01

    The Very Large Telescope (VLT) Telescope Control Software (TCS) is a portable system. It is now in use or will be used in a whole family of ESO telescopes VLT Unit Telescopes, VLTI Auxiliary Telescopes, NTT, La Silla 3.6, VLT Survey Telescope and Astronomical Site Monitors in Paranal and La Silla). Although it has been developed making extensive usage of Object Oriented (OO) methodologies, the overall development process chosen at the beginning of the project used traditional methods. In order to warranty a longer lifetime to the system (improving documentation and maintainability) and to prepare for future projects, we have introduced a full OO process. We have taken as a basis the United Software Development Process with the Unified Modeling Language (UML) and we have adapted the process to our specific needs. This paper describes how the process has been applied to the VLTI Auxiliary Telescopes Control Software (ATCS). The ATCS is based on the portable VLT TCS, but some subsystems are new or have specific characteristics. The complete process has been applied to the new subsystems, while reused code has been integrated in the UML models. We have used the ATCS on one side to tune the process and train the team members and on the other side to provide a UML and WWW based documentation for the portable VLT TCS.

  8. Dynamic analysis of auxiliary buildings in nuclear power plants

    International Nuclear Information System (INIS)

    Subramanian, K.V.; Madhava Rao, A.S.; Warudkar, A.S.

    1989-01-01

    All nuclear power plants have a large number of auxiliary buildings housing various services and control systems required for the operation of the plant. Illustrative examples are turbine building, control building, service building etc. These buildings are seismically qualified as Class I or Class II structures. Usually, these auxiliary buildings are of low rise type with two or three floors and floor heights varying from five to eight meters and of framed construction in steel or concrete or a combination of both the materials. The floors are usually staggered with large cutouts and may not extend over the full area in plan. Some of the bays are often of double story height with the columns continuous over a story in order to accommodate cranes and other equipment. The structural elements supporting the roof may consist of steel roof trusses instead of beams. The seismic analysis of these structures involves the formulation of the analytical model that can simulate the physical behavior of the structure as close as possible taking into consideration the practical aspects. The criteria adopted to formulate the mathematical model has an important bearing on the evaluated dynamic characteristics and seismic response

  9. Stereoselective conjugate radical additions: application of a fluorous oxazolidinone chiral auxiliary for efficient tin removal.

    Science.gov (United States)

    Hein, Jason E; Zimmerman, Jake; Sibi, Mukund P; Hultin, Philip G

    2005-06-23

    [reaction: see text] A series of asymmetric free-radical-mediated intermolecular conjugate additions using a fluorous oxazolidinone chiral auxiliary has been completed. The fluorous auxiliary facilitated product isolation using fluorous solid phase extractions (FSPE), effectively removing excess organic and organometallic reagents. Parallel reactions carried out with a similar but nonfluorous norephedrine-derived oxazolidinone demonstrated the superior stereoselectivity and purification obtainable with the fluorous chiral auxiliary.

  10. Entanglement Capacity of Two-Qubit Unitary Operator with the Help of Auxiliary System

    International Nuclear Information System (INIS)

    Hu Baolin; Di Yaomin

    2007-01-01

    The entanglement capacity of general two-qubit unitary operators is studied when auxiliary systems are allowed, and the analytical results based on linear entropy when input states are disentangled are given. From the results the condition for perfect entangler, α 1 = α 2 = π/4, is obtained. Contrary to the case without auxiliary system, the parameter α 3 may play active role to the entanglement capacity when auxiliary systems are allowed.

  11. The relationship among the solutions of two auxiliary ordinary differential equations

    International Nuclear Information System (INIS)

    Liu Xiaoping; Liu Chunping

    2009-01-01

    In a recent article [Phys. Lett. A 356 (2006) 124], Sirendaoreji extended their auxiliary equation method by introducing a new auxiliary ordinary differential equation (NAODE) and its 14 solutions. Then the author studied some nonlinear evolution equations (NLEEs) and got more exact travelling wave solutions. In this paper, we will show that the 14 solutions of the NAODE are actually the same as the solutions obtained by original auxiliary equation method, and they are only different in the form.

  12. The Future Mission Tasking and Resourcing of the U.S. Coast Guard Auxiliary

    Science.gov (United States)

    2012-09-01

    the years. Therefore, this study cannot present what the demographic makeup of the Auxiliary was at any past point, and cannot identify if there were...Auxiliary, and the Nation’s projected demographic composition. The demographic makeup of the country, the country’s future volunteers, is changing...command in the spring of 2010.104 This one-page document broad- brushes three prioritized overarching Auxiliary missions: 1) to promote and improve

  13. Radiofrequency contact currents: sensory responses and dosimetry

    International Nuclear Information System (INIS)

    Kavet, Robert; Tell, R.A.; Olsen, R.G.

    2014-01-01

    The process of setting science-based exposure standards (or guidelines) for radiofrequency (RF) contact current exposure has been disadvantaged by a lack of relevant data. The authors first review the essential features and results of the available studies and illustrate the apparent discrepancies among them. Then, they examine the manner in which current was administered in these studies and suggest as to how the physical relationship of a contacting finger to the current electrode may play a role in affecting sensory thresholds specific to those configurations. A major factor in this analysis relates to whether current density is uniformly distributed across the contact area or whether an electrode's 'edge effects' enhance currents with a net effect of decreasing apparent thresholds, when expressed as the bulk current entering a subject. For an exposure with a clear hazard potential, thresholds of human sensory response to RF currents require further investigation. (authors)

  14. LAPAROSCOPIC NEPHRECTOMY USING RADIOFREQUENCY THERMAL ABLATION

    Directory of Open Access Journals (Sweden)

    B. Ya. Alekseev

    2012-01-01

    Full Text Available The wide use of current diagnostic techniques, such as ultrasound study, computed tomography, and magnetic resonance imaging, has led to significantly increased detection rates for disease in its early stages. This gave rise to a change in the standards for the treatment of locally advanced renal cell carcinoma (RCC. Laparoscopic nephrectomy (LN has recently become the standard treatment of locally advanced RCC in the clinics having much experience with laparoscopic surgery. The chief drawback of LN is difficulties in maintaining intraoperative hemostasis and a need for creating renal tissue ischemia. The paper gives the intermediate results of application of the new procedure of LN using radiofrequency thermal ablation in patients with non-ischemic early-stage RCC.

  15. Emerging indications of endoscopic radiofrequency ablation

    Science.gov (United States)

    Becq, Aymeric; Camus, Marine; Rahmi, Gabriel; de Parades, Vincent; Marteau, Philippe

    2015-01-01

    Introduction Radiofrequency ablation (RFA) is a well-validated treatment of dysplastic Barrett's esophagus. Other indications of endoscopic RFA are under evaluation. Results Four prospective studies (total 69 patients) have shown that RFA achieved complete remission of early esophageal squamous intra-epithelial neoplasia at a rate of 80%, but with a substantial risk of stricture. In the setting of gastric antral vascular ectasia, two prospective monocenter studies, and a retrospective multicenter study, (total 51 patients), suggest that RFA is efficacious in terms of reducing transfusion dependency. In the setting of chronic hemorrhagic radiation proctopathy, a prospective monocenter study and a retrospective multicenter study (total 56 patients) suggest that RFA is an efficient treatment. A retrospective comparative study (64 patients) suggests that RFA improves stents patency in malignant biliary strictures. Conclusions Endoscopic RFA is an upcoming treatment modality in early esophageal squamous intra-epithelial neoplasia, as well as in gastric, rectal, and biliary diseases. PMID:26279839

  16. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.

    2015-01-01

    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  17. Optical generation of radio-frequency power

    International Nuclear Information System (INIS)

    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%

  18. Radiofrequency identification for inventory in neurointerventional practice.

    Science.gov (United States)

    Byers, Ernest; Gomez, Max A; Sheridan, Robert M; Orr, Nelson W; Hirsch, Joshua A

    2011-03-01

    Implementations of radiofrequency identification (RFID) systems within hospital settings are not unique or without controversy. To date, little consideration has been given to use of this technology in clinical interventional radiologic practice. The potential financial advantages coupled with benefits to quality and safety and increases in staff satisfaction are considerable. The authors outline these advantages by enabling readers to broadly consider the systemic perspective of implementing RFID technology with an associated vision toward downstream growth. Furthermore, the authors demonstrate the benefits of RFID technology integration in reducing cost and increasing quality assurance and the on-time delivery of services. Implementing RFID requires commitment from frontline technologist staff members to work collaboratively with management and external vendors. Ultimately, the authors believe this technology can positively influence patient care. Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  19. Radiofrequency Electromagnetic Field Map of Timisoara

    Science.gov (United States)

    Stefu, N.; Solyom, I.; Arama, A.

    2015-12-01

    There are many electromagnetic field (EMF) sources nowadays acting simultaneously, especially in urban areas, making the theoretical estimation of electromagnetic power at ground level very difficult. This paper reports on EMF maps built with measurements collected in Timisoara, at various radiofrequencies. A grid of 15×15 squares was built (approximate resolution 400m x 400m) and measurements of the average and maximum values of the electric field E, magnetic field H and total power density S at 0.9, 1.8 and 2.4 GHz were collected in every node of the grid. Positions of the nodes in terms of latitude and longitude were also collected. Maps were built presenting the spatial distribution of the measured quantities over Timisoara. Potential influences of EMF on public health are discussed.

  20. Freescale Sdn Bhd: Monitoring Radiofrequency Assessment

    International Nuclear Information System (INIS)

    Wan Saffiey Wan Abdullah; Noor Ezati Shuib; Rozaimah Abdul Rahim; Pasupathy, E.; Muhammad Yusri Yahaya

    2015-01-01

    Freescale Semiconductor (M) Sdn Bhd, requested the assistance of Malaysian Nuclear Agency (Nuclear Malaysia) to conduct an electromagnetic radiation (Radiofrequency Radiation) measurements around its facilities at Freescale Semiconductor (M) Sdn Bhd, 2, Jalan SS8/2, Sungai Wai Free Industrial Zone, 47300 Petaling Jaya, Selangor. Nuclear Agency Non-Ionising Radiation (NIR) Group carried out the measurement on 30th July 2012. In carrying out the work, the Group was assisted by Mr Daniel. The main objectives of the measurement were to assess the presence of electromagnetic radiation (RF field) in an accessible work places within and around the facilities and to advise the company on outcomes of the assessment and measurement based on international recommendations of standard guidelines issued by Malaysian Communication and Multimedia Commission (MCMC) and International Commission on Non-Ionising Radiation Protection (ICNIRP). (author)

  1. Radio-frequency quadrupole linear accelerator

    International Nuclear Information System (INIS)

    Wangler, T.P.; Stokes, R.H.

    1980-01-01

    The radio-frequency quadrupole (RFQ) is a new linear accelerator concept in which rf electric fields are used to focus, bunch, and accelerate the beam. Because the RFQ can provide strong focusing at low velocities, it can capture a high-current dc ion beam from a low-voltage source and accelerate it to an energy of 1 MeV/nucleon within a distance of a few meters. A recent experimental test at the Los Alamos Scientific Laboratory (LASL) has confirmed the expected performance of this structure and has stimulated interest in a wide variety of applications. The general properties of the RFQ are reviewed and examples of applications of this new accelerator are presented

  2. A battery-fuel cell hybrid auxiliary power unit for trucks: Analysis of direct and indirect hybrid configurations

    International Nuclear Information System (INIS)

    Samsun, Remzi Can; Krupp, Carsten; Baltzer, Sidney; Gnörich, Bruno; Peters, Ralf; Stolten, Detlef

    2016-01-01

    Highlights: • A battery-fuel cell hybrid auxiliary power unit for heavy duty vehicles is reported. • Comparison of direct and indirect hybrids using representative load profiles. • Evaluation based on validated fuel cell system and battery models. • Indirect hybrid with constant fuel cell load yields 29.3% hybrid system efficiency. • Fuel cell should be pre-heated using waste heat from the diesel engine during drive. - Abstract: The idling operation of engines in heavy duty vehicles to cover electricity demand during layovers entails significant fuel consumption and corresponding emissions. Indeed, this mode of operation is highly inefficient and a noteworthy contributor to the transportation sector’s aggregate carbon dioxide emissions. Here, a potential solution to this wasteful practice is outlined in the form of a hybrid battery-fuel cell system for application as an auxiliary power unit for trucks. Drawing on experimentally-validated fuel cell and battery models, several possible hybrid concepts are evaluated and direct and indirect hybrid configurations analyzed using a representative load profile. The results indicate that a direct hybrid configuration is only applicable if the load demand profile does not deviate strongly from the assumed profile. Operation of an indirect hybrid with a constant fuel cell load yields the greatest hybrid system efficiency, at 29.3%, while battery size could be reduced by 87% if the fuel cell is operated at the highest dynamics. Maximum efficiency in truck applications can be achieved by pre-heating the system prior to operation using exhaust heat from the motor, which increased system efficiency from 25.3% to 28.1%, including start-up. These findings confirm that hybrid systems could offer enormous fuel savings and constitute a sizeable step on the path toward energy-efficient and environmentally-friendly heavy duty vehicles that does not necessitate a fuel switch.

  3. Experimental fast reactor JOYO MK-III functional test. Primary auxiliary cooling system test

    International Nuclear Information System (INIS)

    Karube, Koji; Akagi, Shinji; Terano, Toshihiro; Onuki, Osamu; Ito, Hideaki; Aoki, Hiroshi; Odo, Toshihiro

    2004-03-01

    This paper describes the results of primary auxiliary cooling system, which were done as a part of JOYO MK-III function test. The aim of the tests was to confirm the operational performance of primary auxiliary EMP and the protection system including siphon breaker of primary auxiliary cooling system. The items of the tests were: (Test No.): (Test item). 1) SKS-117: EMP start up test. 2) SKS-118-1: EMP start up test when pony motor running. 3) SKS-121: Function test of siphon breaker. The results of the tests satisfied the required performance, and demonstrated successful operation of primary auxiliary cooling system. (author)

  4. Effect of Mobile Phone Radiofrequency Electromagnetic Fields on ...

    African Journals Online (AJOL)

    olayemitoyin

    Summary: Since cell phones emit radiofrequency electromagnetic fields (EMFs), this study tested the hypothesis that cell phones placed ... mobile phones on autonomic modulation of the heart. ..... Electrocardiogram and Its Technology. J. Am.

  5. Radio-frequency wave enhanced runaway production rate

    International Nuclear Information System (INIS)

    Chan, V.S.; McClain, F.W.

    1983-01-01

    Enhancement of runaway electron production (over that of an Ohmic discharge) can be achieved by the addition of radio-frequency waves. This effect is studied analytically and numerically using a two-dimensional Fokker--Planck quasilinear equation

  6. Administrative norms on radiofrequency radiation for occupationally exposed persons

    International Nuclear Information System (INIS)

    Saxeboel, G.

    1982-01-01

    The report presents a proposal for administrative norms on radiofrequency (RF) radiation for occupationally exposed persons. The norms establish maximum allowable field exposure in a frequency range from 1 MHz too 300 GHz. (RF)

  7. Ion-storage in radiofrequency electric quadrupole field

    International Nuclear Information System (INIS)

    Gheorghe, V.

    1976-01-01

    The confinement of charged particles in a quadrupole radiofrequency electric field are presented. The stability diagrams and phase space trajectories for the quadrupole mass spectrometer and for the ion trap are represented and their main characteristics are discussed. (author)

  8. Process for selected gas oxide removal by radiofrequency catalysts

    Science.gov (United States)

    Cha, Chang Y.

    1993-01-01

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

  9. Combined Effect of Ambient Temperature with Radiofrequency Electromagnetic Radiation in Rabbit

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Choi, Dae Seong; Komarova, Ludmila N.; Petin, Vladislav G.

    2010-01-01

    There has been an increasing interest in synergistic effects observed after combined action of various agents. Many studies have shown that numerous physical and chemical agents combined with hyperthermia can interact in a synergistic manner when the effect produced by both agents used in combination exceeded the expected results from simple summation of the every effect produced by heat and the particular agent. I t was found that ambient temperature had a profound effect on the thermoregulatory responses to radiofrequency electromagnetic radiation (RFR) in various animals and humans. An extensive quantitative investigation of synergistic interaction of ambient temperature and microwaves has been published for rabbit heating. I t would be of interest to estimate whether or not the general features of the combined action revealed with unicellular organisms can be expressed for animals exposed to microwave power combined with a higher environmental temperature.

  10. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

    Energy Technology Data Exchange (ETDEWEB)

    Aerts, Sam, E-mail: sam.aerts@intec.ugent.be; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-15

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km{sup 2}. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an

  11. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

    International Nuclear Information System (INIS)

    Aerts, Sam; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-01-01

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km 2 . In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an

  12. Paying attention to radiofrequency ablation therapy for neoplasms

    International Nuclear Information System (INIS)

    Wang Zhongming; Li Linsun

    2010-01-01

    Radiofrequency ablation is an effective treatment for malignant tumors. With the development of imaging technique, it has been widely used in treating different kinds of malignant tumors, such as liver cancer, lung cancer, kidney carcinoma, etc. Radiofrequency ablation has a lot of advantages. As a minimally-invasive, safe and effective treatment with less sufferings and fewer complications, this technique has attracted more and more attention of the experts both at home and abroad. (authors)

  13. Eye examinations of laser and radiofrequency radiation workers

    International Nuclear Information System (INIS)

    Hocking, B.

    1988-01-01

    There are a growing number of uses of lasers and radiofrequency radiation in industry. Because these radiations may lead to various ocular effects, examinations of the eye are required for laser and radiofrequency workers as part of safe working practices. Various issues concerning these examinations are raised for discussion including: handling personal data, placement criteria, data collection, quality control, control data, the load on service providers, and costs

  14. Saline-enhanced radiofrequency electrocoagulation in bovine liver

    International Nuclear Information System (INIS)

    Shin, Hong Seop; Oh, Joo Hyeong; Yoon, Yup; Kim, Hyun Cheol; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Kim, Eui Jong

    1997-01-01

    To determine the effectiveness of saline-enhanced radiofrequency electrocoagulation in bovine liver tissue Saline-enhanced radiofrequency electrocoagulation (group I), hot saline injection induced by radiofrequency electrocoagulation (group II), and radiofrequency electrocoagulation (group III) were performed in ex vivo bovine liver. Radiofrequency power was 100 and 200 watts, and current was applied for 10, 20, and 30 seconds. Tissue was histopathologically examined for thermal injury. The largest diameter of thermal injury was about 41.0 mm in group I, 12.3 mm in group II and 9.3 mm in group III. The mean diameter of the injury increased with higher wattage in group I and II and with longer procedure time in group I (p<0.05). At corresponding wattage and times, group I showed a larger diameter of thermal injury and more increase in than group II or III (p<0.05). The degree of carbonization was more severe in group III than in groups I and II. Grossly, thermal injury showed a well-defined, relatively spherical configuration without extension along parenchymal interstitium. In an animal model, saline-enhanced radiofrequency electrocoagulation may effectively induce thermal injury, and may thus be another effective tool for use in the treatment of hepatic tumors. Further clinical experience is needed

  15. Treatment of Refractory Idiopathic Supraorbital Neuralgia Using Percutaneous Pulsed Radiofrequency.

    Science.gov (United States)

    Luo, Fang; Lu, Jingjing; Ji, Nan

    2018-02-26

    No ideal therapeutic method currently exists for refractory idiopathic supraorbital neuralgia patients who do not respond to conservative therapy, including medications and nerve blocks. Pulsed radiofrequency is a neuromodulation technique that does not produce sequelae of nerve damage after treatment. However, the efficacy of percutaneous pulsed radiofrequency for the treatment of refractory idiopathic supraorbital neuralgia is still not clear. The purpose of our study was to evaluate the efficacy and safety of pulsed radiofrequency treatment of the supraorbital nerve for refractory supraorbital neuralgia patients. We prospectively investigated the long-term effects of ultrasound-guided percutaneous pulsed radiofrequency in the treatment of 22 refractory idiopathic supraorbital neuralgia patients. A reduction in the verbal pain numeric rating scale score of more than 50% was used as the standard of effectiveness. The effectiveness rates at different time points within 2 years were calculated. After a single pulsed radiofrequency treatment, the effectiveness rate at 1 and 3 months was 77%, and the rates at 6 months, 1 year, and 2 years were 73%, 64%, and 50%, respectively. Except for a small portion of patients (23%) who experienced mild upper eyelid ecchymosis that gradually disappeared after approximately 2 weeks, no obvious complications were observed. In conclusion, the results of our study demonstrate that for patients with refractory idiopathic supraorbital neuralgia, percutaneous pulsed radiofrequency may be an effective and safe treatment choice. © 2018 World Institute of Pain.

  16. Saline-enhanced radiofrequency electrocoagulation in bovine liver

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hong Seop; Oh, Joo Hyeong; Yoon, Yup; Kim, Hyun Cheol; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Kim, Eui Jong [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

    1997-08-01

    To determine the effectiveness of saline-enhanced radiofrequency electrocoagulation in bovine liver tissue Saline-enhanced radiofrequency electrocoagulation (group I), hot saline injection induced by radiofrequency electrocoagulation (group II), and radiofrequency electrocoagulation (group III) were performed in ex vivo bovine liver. Radiofrequency power was 100 and 200 watts, and current was applied for 10, 20, and 30 seconds. Tissue was histopathologically examined for thermal injury. The largest diameter of thermal injury was about 41.0 mm in group I, 12.3 mm in group II and 9.3 mm in group III. The mean diameter of the injury increased with higher wattage in group I and II and with longer procedure time in group I (p<0.05). At corresponding wattage and times, group I showed a larger diameter of thermal injury and more increase in than group II or III (p<0.05). The degree of carbonization was more severe in group III than in groups I and II. Grossly, thermal injury showed a well-defined, relatively spherical configuration without extension along parenchymal interstitium. In an animal model, saline-enhanced radiofrequency electrocoagulation may effectively induce thermal injury, and may thus be another effective tool for use in the treatment of hepatic tumors. Further clinical experience is needed.

  17. Conventional Radiofrequency Thermocoagulation vs Pulsed Radiofrequency Neuromodulation of Ganglion Impar in Chronic Perineal Pain of Nononcological Origin.

    Science.gov (United States)

    Usmani, Hammad; Dureja, G P; Andleeb, Roshan; Tauheed, Nazia; Asif, Naiyer

    2018-01-10

    Chronic nononcological perineal pain has been effectively managed by ganglion Impar block. Chemical neurolysis, cryoablation, and radiofrequency ablation have been the accepted methods of blockade. Recently, pulsed radiofrequency, a novel variant of conventional radiofrequency, has been used for this purpose. This was a prospective, randomized, double-blind study. Two different interventional pain management centers in India. To compare the efficacy of conventional radiofrequency and pulsed radiofrequency for gangliom Impar block. The patients were randomly allocated to one of two groups. In the conventional radiofrequency (CRF) group (N = 34), conventional radiofrequency ablation was done, and in the PRF pulsed radiofrequency (PRF) group (N = 31), pulsed radiofrequency ablation was done. After informed and written consent, fluoroscopy-guided ganglion Impar block was performed through the first intracoccygeal approach. The extent of pain relief was assessed by visual analog scale (VAS) at 24 hours, and at the first, third, and sixth weeks following the intervention. A questionnaire to evaluate subjective patient satisfaction was also used at each follow-up visit. In the CRF group, the mean VAS score decreased significantly from the baseline value at each follow-up visit. But in the PRF group, this decrease was insignificant except at 24-hour follow-up. Intergroup comparison also showed significantly better pain relief in the CRF group as compared with the PRF group. At the end of follow-up, 28 patients (82%) in the CRF group and four patients (13%) in the PRF group had excellent results, as assessed by the subjective patient satisfaction questionnaire. There was no complication in any patient of either study group, except for short-lived infection at the site of skin puncture in a few. Ganglion Impar block by conventional radiofrequency provided a significantly better quality of pain relief with no major side effects in patients with chronic

  18. Investigations of Intelligent Solar Heating Systems for Single Family House

    DEFF Research Database (Denmark)

    Andersen, Elsa; Chen, Ziqian; Fan, Jianhua

    2014-01-01

    Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank is a......, the control strategy of intelligent solar heating systems is investigated and the yearly auxiliary energy use of the systems and the electricity price for supplying the consumers with domestic hot water and space heating are calculated....... systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys......Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank...

  19. Comparison of wet radiofrequency ablation with dry radiofrequency ablation and radiofrequency ablation using hypertonic saline preinjection: ex vivo bovine liver

    International Nuclear Information System (INIS)

    Lee, Jeong Min; Han, Joon Koo; Kim, Se Hyung; Lee, Jae Young; Park, Hee Sun; Hur, Hurn; Choi, Byung Ihn; Shin, Kyung Sook

    2004-01-01

    We wished to compare the in-vitro efficiency of wet radiofrequency (RF) ablation with the efficiency of dry RF ablation and RF ablation with preinjection of NaCl solutions using excised bovine liver. Radiofrequency was applied to excised bovine livers in a monopolar mode for 10 minutes using a 200 W generator and a perfused-cooled electrode with or without injection or slow infusion of NaCl solutions. After placing the perfused-cooled electrode in the explanted liver, 50 ablation zones were created with five different regimens: group A; standard dry RF ablation, group B; RF ablation with 11 mL of 5% NaCl solution preinjection, group C; RF ablation with infusion of 11 mL of 5% NaCl solution at a rate of 1 mL/min, group D; RFA with 6 mL of 36% NaCl solution preinjection, group E; RF ablation with infusion of 6 mL of 36% NaCl solution at a rate of 0.5 mL/min. In groups C and E, infusion of the NaCl solutions was started 1 min before RF ablation and then maintained during RF ablation (wet RF ablation). During RF ablation, we measured the tissue temperature at 15 mm from the electrode. The dimensions of the ablation zones and changes in impedance, current and liver temperature during RF ablation were then compared between the groups. With injection or infusion of NaCl solutions, the mean initial tissue impedance prior to RF ablation was significantly less in groups B, C, D, and E (43-75 Ω) than for group A (80 Ω) (ρ 3 in group A; 12.4 ± 3.8 cm 3 in group B; 80.9 ± 9.9 cm 3 in group C; 45.3 ± 11.3 cm 3 in group D and 81.6 ± 8.6 cm 3 in group E. The tissue temperature measured at 15 mm from the electrode was higher in groups C, D and E than other groups (ρ < 0.05): 53 ± 12 .deg. C in group A, 42 ± 2 .deg. C in group B, 93 ± 8 .deg. C in group C; 79 ± 12 .deg. C in group D and 83 ± 8 .deg.C in group E. Wet RF ablation with 5% or 36% NaCl solutions shows better efficiency in creating a large ablation zone than does dry RF ablation or RF ablation with

  20. Design of auxiliary shield for remote controlled metallographic microscope

    International Nuclear Information System (INIS)

    Matsui, Hiroki; Okamoto, Hisato

    2014-06-01

    The remote controlled optical microscope installed in the lead cell at the Reactor Fuel Examination Facility (RFEF) in Japan Atomic Energy Agency (JAEA) has been upgraded to a higher performance unit to study the effect of the microstructural evolution in clad material on the high burn-up fuel behavior under the accident condition. The optical pass of the new microscope requires a new through hole in the shielding lead wall of the cell. To meet safety regulations, auxiliary lead shieldings were designed to cover the lost shielding function of the cell wall. Particle and Heavy Ion Transport Code System (PHITS) was used to calculate and determine the shape and setting positions of the shielding unit. Seismic assessments of the unit were also performed. (author)

  1. LOX/LH2 vane pump for auxiliary propulsion systems

    Science.gov (United States)

    Hemminger, J. A.; Ulbricht, T. E.

    1985-01-01

    Positive displacement pumps offer potential efficiency advantages over centrifugal pumps for future low thrust space missions. Low flow rate applications, such as space station auxiliary propulsion or dedicated low thrust orbiter transfer vehicles, are typical of missions where low flow and high head rise challenge centrifugal pumps. The positive displacement vane pump for pumping of LOX and LH2 is investigated. This effort has included: (1) a testing program in which pump performance was investigated for differing pump clearances and for differing pump materials while pumping LN2, LOX, and LH2; and (2) an analysis effort, in which a comprehensive pump performance analysis computer code was developed and exercised. An overview of the theoretical framework of the performance analysis computer code is presented, along with a summary of analysis results. Experimental results are presented for pump operating in liquid nitrogen. Included are data on the effects on pump performance of pump clearance, speed, and pressure rise. Pump suction performance is also presented.

  2. Development of the APR+ Auxiliary Building General Arrangement (GA)

    International Nuclear Information System (INIS)

    Moon, Hyung Keun; Park, Young Sheop; Kang, Yong Chul

    2011-01-01

    The general arrangement (GA) drawing of a nuclear power plant is the most basic drawing which contains all of the plant equipment, systems, and rooms. Therefore, it should be issued at an early design stage to provide the contours of the overall plant structure. This type of drawing is typically used widely throughout the design stages. The development project of APR+ (Advanced Power Reactor+), as a succeeding model of the APR1400 (Advanced Power Reactor 1400) design, has its own GA that encompasses all of its power buildings. This was developed starting in October of 2009. Among several of the buildings in this design, the Auxiliary Building (AB) is one of the most important buildings to produce electricity, and to protect against undesirable radiation emissions. This paper focuses on the design characteristics of the general arrangement of the AB

  3. Auxiliary fields in the geometrical relativistic particle dynamics

    International Nuclear Information System (INIS)

    Amador, A; Bagatella, N; Rojas, E; Cordero, R

    2008-01-01

    We describe how to construct the dynamics of relativistic particles, following either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline. We point out that the mechanical content of such models can be extracted wisely from a lower order action, which can be performed by implementing in the action a finite number of constraints that involve the geometrical relationship structures inherent to a curve and by using a covariant formalism. We emphasize our approach for null curves. For such systems, the natural time parameter is a pseudo-arclength whose properties resemble those of the standard proper time. We illustrate the formalism by applying it to some models for relativistic particles

  4. Auxiliary fields in the geometrical relativistic particle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Amador, A; Bagatella, N; Rojas, E [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico); Cordero, R [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N, Edificio 9, 07738 Mexico D.F (Mexico)], E-mail: aramador@gmail.com, E-mail: nbagatella@uv.mx, E-mail: cordero@esfm.ipn.mx, E-mail: efrojas@uv.mx

    2008-03-21

    We describe how to construct the dynamics of relativistic particles, following either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline. We point out that the mechanical content of such models can be extracted wisely from a lower order action, which can be performed by implementing in the action a finite number of constraints that involve the geometrical relationship structures inherent to a curve and by using a covariant formalism. We emphasize our approach for null curves. For such systems, the natural time parameter is a pseudo-arclength whose properties resemble those of the standard proper time. We illustrate the formalism by applying it to some models for relativistic particles.

  5. Bistable energy harvesting enhancement with an auxiliary linear oscillator

    Science.gov (United States)

    Harne, R. L.; Thota, M.; Wang, K. W.

    2013-12-01

    Recent work has indicated that linear vibrational energy harvesters with an appended degree-of-freedom (DOF) may be advantageous for introducing new dynamic forms to extend the operational bandwidth. Given the additional interest in bistable harvester designs, which exhibit a propitious snap through effect from one stable state to the other, it is a logical extension to explore the influence of an added DOF to a bistable system. However, bistable snap through is not a resonant phenomenon, which tempers the presumption that the dynamics induced by an additional DOF on bistable designs would inherently be beneficial as for linear systems. This paper presents two analytical formulations to assess the fundamental and superharmonic steady-state dynamics of an excited bistable energy harvester to which is attached an auxiliary linear oscillator. From an energy harvesting perspective, the model predicts that the additional linear DOF uniformly amplifies the bistable harvester response magnitude and generated power for excitation frequencies less than the attachment’s resonance while improved power density spans a bandwidth below this frequency. Analyses predict bandwidths having co-existent responses composed of a unique proportion of fundamental and superharmonic dynamics. Experiments validate key analytical predictions and observe the ability for the coupled system to develop an advantageous multi-harmonic interwell response when the initial conditions are insufficient for continuous high-energy orbit at the excitation frequency. Overall, the addition of an auxiliary linear oscillator to a bistable harvester is found to be an effective means of enhancing the energy harvesting performance and robustness.

  6. STARTER-GENERATOR SYSTEM FOR AUXILIARY POWER UNIT

    Directory of Open Access Journals (Sweden)

    A. V. Levin

    2017-01-01

    Full Text Available The article presents a starter-generator system for an auxiliary power unit of an aircraft. A feature of the presented system is the use of a synchronous generator with excitation from permanent magnets and a semiconductor converter. The main problem of the system is the generation of electric energy of an aircraft on the basis of a synchronous generator with excitation from permanent magnets is the absence of the possibility of regulating the voltage and frequency of electrical energy, in this connection, a semiconductor converter that ensures the conversion of generated electric energy with significant mass-dimensions characteristics.The article proposes an approach to designing a starter-generator system with a parallel connection of a synchronous generator with excitation from permanent magnets and a semiconductor converter. This approach makes it possible to significantly reduce the part of the electrical energy that needs to be converted, as a consequence, the semiconductor converter has significantly smaller mass-and-batch characteristics.In the article the modes of generation of electric energy and the starter mode of operation of the starter-generator system are considered in detail, the circuit realization of the semiconductor converter is shown. A scheme for replacing one phase of the system for generating electric energy and calculating electric parameters is presented.The possibility of creating a highly efficient starter-generator system based on a synchronous generator with excitation from permanent magnets and a semiconductor converter for an auxiliary power plant of aircrafts is shown. Structural and basic schemes for constructing a system for generating electrical energy are proposed. The approach to the choice of rational circuit solutions is substantiated, basic estimates of the electrical parameters of the system are obtained. The possibility of achieving a specific mass of a semiconductor converter for synchronous

  7. Radiofrequency thermal ablation of benign cystic lesion: an experimental pilot study in a porcine gallbladder model

    International Nuclear Information System (INIS)

    Song, Ho Taek; Rhim, Hyun Chul; Choi, Jung Bin; Oh, Jae Cheon; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Seo, Heung Suk; Joo, Kyung Bin

    2001-01-01

    To determine whether radiofrequency thermal ablation can be used to treat benign cystic lesions in a porcine gallbladder model. This experimental study of radiofrequency thermal ablation involved the use of 15 exvivo porcine gallbladders and 15-G expandable needle electrodes. To investigate optimal temperature parameters, three groups of five were designated according to target temperature:Group A: 70 deg C; Group B: 80 deg C; Group C: 90 deg C. After the target temperature was reached, ablation lasted for one minute. Gallbladder width, height and length were measured before and after ablation , and the estimated volume reduction ratios of the three groups were compared. Whether adjacent liver parenchyma around the gallbladder fossa was ablated by heat conducted from hot bile was also determined, and the thickness of the ablated area of the liver was measured. The volume reduction ratio in Group A, B and C was 42.7%, 41.7% and 42.9%, respectively (ρ>.05). In all 15 cases, gallbladder walls lost their transparency and elasticity at about 70 deg C. In nine of ten cases in Groups B and C, the hepatic capsule around the gallbladder fossa was retracted at about 80 deg C. The mean thickness of liver parenchymal damage adjacent to the gallbladder was 5.4 mm in Group B and 9.8 mm in Group C. In Group A livers, only one case showed minimal gradual parenchymal change. Microscopically, all three groups showed complete coagulation necrosis of the wall. On the basis of this feasibility study, radiofrequency thermal ablation is potentially suitable for the ultrasound-guided treatment of symptomatic cystic lesions including benign hepatic or renal cyst

  8. The efficacy of two electrodes radiofrequency technique: comparison study using a cadaveric interspinous ligament and temperature measurement using egg white.

    Science.gov (United States)

    Lee, Chang-Hyung; Derby, Richard; Choi, Hyun-Seok; Lee, Sang-Heon; Kim, Se Hoon; Kang, Yoon Kyu

    2010-01-01

    One technique in radiofrequency neurotomies uses 2 electrodes that are simultaneously placed to lie parallel to one another. Comparing lesions on cadaveric interspinous ligament tissue and measuring the temperature change in egg white allows us to accurately measure quantitatively the area of the lesion. Fresh cadaver spinal tissue and egg white tissue were used. A series of samples were prepared with the electrodes placed 1 to 7 mm apart. Using radiofrequency, the needle electrodes were heated in sequential or simultaneous order and the distance of the escaped lesion area and temperature were measured. Samples of cadaver interspinous ligament showed sequential heating of the needles limits the placement of the needle electrodes up to 2 mm apart from each other and up to 4 mm apart when heated simultaneously. The temperature at the escaped lesion area decreased according to the distance for egg white. There was a significant difference in temperature at the escaped lesion area up to 6 mm apart and the temperature was above 50 degrees celsius up to 5 mm in simultaneous lesion and 3 mm in the sequential lesion. The limitations of this study include cadaveric experimentation and use of intraspinous ligament rather than medial branch of the dorsal ramus which is difficult to identify. Heating the 2 electrodes simultaneously appears to coagulate a wider area and potentially produce better results in less time.

  9. Modal Auxiliaries and Their Semantic Functions Used by Advanced EFL Learners

    Science.gov (United States)

    Torabiardakani, Najmeh; Khojasteh, Laleh; Shokrpour, Nasrin

    2015-01-01

    Since modal auxiliary verbs have been proved to be one of the most troublesome grammatical structures in English, the researchers of this study decided to do an analysis on the ways in which advanced EFL Iranian students use modal auxiliaries focusing specially on nine modals' semantic functions. Consequently, was conducted based on the following…

  10. Auxiliary Armed Forces and Innovations in Security Governance in Mozambique’s Civil War

    NARCIS (Netherlands)

    Jentzsch, C.

    2017-01-01

    Who rules during the civil war? This article argues that the concept of armed group governance must be expanded to include auxiliary armed forces linked to rebels or the government. Comparing the organization of rebel and government auxiliaries, the article demonstrates that security governance

  11. 14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine tests in auxiliary power unit (APU... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...

  12. Auxiliary bearing design and rotor dynamics analysis of blower fan for HTR-10

    International Nuclear Information System (INIS)

    Gao Mingshan; Yang Guojun; Xu Yang; Zhao Lei; Yu Suyuan

    2005-01-01

    The electromagnetic bearing instead of ordinary mechanical bearing was chosen to support the rotor in the blower fan system with helium of 10 MW high temperature gas-cooled test reactor (HTR-10), and the auxiliary bearing was applied in the HTR-10 as the backup protector. When the electromagnetic bearing doesn't work suddenly for the power broken, the auxiliary bearing is used to support the falling rotor with high rotating speed. The rotor system will be protected by the auxiliary bearing. The design of auxiliary bearing is the ultimate safeguard for the system. This rotor is vertically mounted to hold the blower fan. The rotor's length is about 1.5 m, its weight is about 240 kg and the rotating speed is about 5400 r/min. Auxiliary bearing design and rotor dynamics analysis are very important for the design of blower fan to make success. The research status of the auxiliary bearing was summarized in the paper. A sort of auxiliary bearing scheme was proposed. MSC.Marc was selected to analyze the vibration mode and the natural frequency of the rotor. The scheme design of auxiliary bearing and analysis result of rotor dynamics offer the important theoretical base for the protector design and control system of electromagnetic bearing of the blower fan. (authors)

  13. How Does Dissociation between Written and Oral Forms Affect Reading: Evidence from Auxiliary Verbs in Arabic

    Science.gov (United States)

    Ibrahim, Raphiq

    2011-01-01

    In Arabic, auxiliary verbs are necessary in the written language, but absent from the oral language. This is contrary to languages such as English and French in which auxiliary verbs are mandatory in both written and oral languages. This fact was exploited to examine if dissociation between written and oral forms affects reading measures like…

  14. Dummy auxiliaries in child and adult second language acquisition of Dutch

    NARCIS (Netherlands)

    Blom, W.B.T.; de Korte, S.

    2011-01-01

    In previous research it has been observed that second language (L2) learners of Dutch and German use analytic verbs in contexts where the target language requires synthetic verbs. These analytic verbs consist of a semantically empty auxiliary (dummy auxiliary) that selects a lexical infinitive. In

  15. A probabilistic evaluation of the Shearon Harris Nuclear Power Plant auxiliary feedwater isolation system

    International Nuclear Information System (INIS)

    Anoba, R.C.

    1989-01-01

    This paper reports on a fault tree approach that was used to evaluate the safety significance of modifying the Shearon Harris Auxiliary Feedwater Isolation System. The design modification was a result of on-site reviews which identified a single failure in the Auxiliary Feedwater Isolation circuitry

  16. 29 CFR Appendix II to Part 1918 - Tables for Selected Miscellaneous Auxiliary Gear (Mandatory)

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Tables for Selected Miscellaneous Auxiliary Gear (Mandatory) II Appendix II to Part 1918 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND.... 1918, App. II Appendix II to Part 1918—Tables for Selected Miscellaneous Auxiliary Gear (Mandatory...

  17. Goal programming for cyclical auxiliary police scheduling at UiTM Cawangan Perlis

    Science.gov (United States)

    Mustapar, Wasilatul Effah; Nasir, Diana Sirmayunie Mohd; Nor, Nor Azriani Mohamad; Abas, Sharifah Fhahriyah Syed

    2017-11-01

    Constructing a good and fair schedule for shift workers poses a great challenge as it requires a lot of time and effort. In this study, goal programming has been applied on scheduling to achieve the hard and soft constraints for a cyclical schedule that would ease the head of auxiliary police at building new schedules. To accomplish this goal, shift types were assigned in order to provide a fair schedule that takes into account the auxiliary police's policies and preferences. The model was run using Lingo software. Three out of four goals set for the study were achieved. In addition, the results considered an equal allocation for every auxiliary police, namely 70% for total duty and 30% for the day. Furthermore, the schedule was able to cyclically generate another 10 sets schedule. More importantly, the model has provided unbiased scheduling of auxiliary policies which led to high satisfaction in auxiliary police management.

  18. Percutaneous radiofrequency treatment for refractory anteromedial pain of osteoarthritic knees.

    Science.gov (United States)

    Ikeuchi, Masahiko; Ushida, Takahiro; Izumi, Masashi; Tani, Toshikazu

    2011-04-01

    Although severe knee osteoarthritis with refractory pain is commonly treated surgically, this is often not an option for patients with poor health status or unwillingness to undergo major surgery. We examined the efficacy of radiofrequency application to sensory nerves as a novel alternative treatment for refractory knee pain. This study was an open-label, nonrandomized, and controlled study. Patients complaining of refractory anteromedial knee pain associated with radiological osteoarthritis (moderate or severe) were included. They were assigned to one of two groups: those receiving radiofrequency thermocoagulation (N = 18) or those receiving nerve block (N = 17), depending on the time period that they were referred to the clinic. Radiofrequency current or local anesthetics was applied to the medial retinacular nerve and the infrapatellar branch of the saphenous nerve. Western Ontario McMaster Universities osteoarthritis index score, pain visual analog scale (VAS), and patient's global assessment were assessed with a minimum follow-up of 6 months.   Radiofrequency treatment significantly decreased knee pain as measured by VAS for 12 weeks compared with the control group. In terms of responders, more patients in the RF group responded to the treatment than in the control group. The differences were statistically significant at 4 weeks, 8 weeks, and 12 weeks in pain VAS. Eight patients (44%) treated with radiofrequency rated excellent or good but only three (18%) in the control group rated good, although the difference was not statistically significant. Some patients were able to benefit substantially from radiofrequency treatment. Even if its effective period is limited, radiofrequency application is a promising treatment to alleviate refractory anteromedial knee pain with osteoarthritis. Further experience and technical improvements are needed to establish its role in the management of knee osteoarthritis. Wiley Periodicals, Inc.

  19. Simulation Study of the Energy Performance of Different Space Heating Methods in Plus-energy Housing

    DEFF Research Database (Denmark)

    Schøtt, Jacob; Andersen, Mads E.; Kazanci, Ongun Berk

    2016-01-01

    Due to a shortage of energy resources, the focus on indoor environment and energy use in buildings is increasing which sets higher standards for the performance of HVAC systems in buildings. The variety of available heating systems for both residential buildings and office buildings is therefore...... cases the heat source was a natural gas fired condensing boiler, and for the floor heating cases also an air-to-water heat pump was used to compare two heat sources. The systems were also compared in terms of auxiliary energy use for pumps and fans. The results show that the investigated floor heating...... from the low temperature heating potential since an increased floor covering requires higher average water temperatures in the floor loops and decreases the COP of the heat pump. The water-based heating systems required significantly less auxiliary energy input compared to the air-based heating system...

  20. Heralded linear optical quantum Fredkin gate based on one auxiliary qubit and one single photon detector

    International Nuclear Information System (INIS)

    Zhu Chang-Hua; Cao Xin; Quan Dong-Xiao; Pei Chang-Xing

    2014-01-01

    Linear optical quantum Fredkin gate can be applied to quantum computing and quantum multi-user communication networks. In the existing linear optical scheme, two single photon detectors (SPDs) are used to herald the success of the quantum Fredkin gate while they have no photon count. But analysis results show that for non-perfect SPD, the lower the detector efficiency, the higher the heralded success rate by this scheme is. We propose an improved linear optical quantum Fredkin gate by designing a new heralding scheme with an auxiliary qubit and only one SPD, in which the higher the detection efficiency of the heralding detector, the higher the success rate of the gate is. The new heralding scheme can also work efficiently under a non-ideal single photon source. Based on this quantum Fredkin gate, large-scale quantum switching networks can be built. As an example, a quantum Beneš network is shown in which only one SPD is used. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  1. Systems for Nuclear Auxiliary Power annual report, government fiscal year 1976/TQ

    International Nuclear Information System (INIS)

    1976-01-01

    The overall objective of the Systems for Nuclear Auxiliary Power (SNAP) Program is to continue system and component engineering activities relating to the zirconium hydride (ZrH) reactor. The specific objectives for FY 1976/TQ were to: (1) study standardized ZrH reactor space power systems and components, (2) perform preconceptual analysis and design of ZrH reactor--organic Rankine power systems for subsea applications, (3) conduct fuel and hydrogen barrier investigations, (4) perform system studies in support of the Department of Defense and their contractors as directed by ERDA, (5) test components, and (6) provide for material disposal and facility surveillance. In the study, representative systems which utilize Brayton, Rankine, and Stirling cycle power conversion units as well as thermoelectric modules, are analyzed at power levels of 10, 25, 50, and 75 kWe. Waste heat rejection is accomplished by concentric, cylindrical space radiators which can be nested during launch for space shuttle integration. Subsequent studies, which supported this effort, were completed and provided useful information on system reliability and survivability

  2. Heat Transfer Characteristics of SiC-coated Heat Pipe for Passive Decay Heat Removal

    International Nuclear Information System (INIS)

    Kim, Kyung Mo; Kim, In Guk; Jeong, Yeong Shin; Bang, In Cheol

    2014-01-01

    The main concern with the Fukushima accident was the failure of active and passive core cooling systems. The main function of existing passive decay heat removal systems is feeding additional coolant to the reactor core. Thus, an established emergency core cooling system (ECCS) cannot operate properly because of impossible depressurization under the station blackout (SBO) condition. Therefore, a new concept for passive decay heat removal system is required. In this study, an innovative hybrid control rod concept is considered for passive in-core decay heat removal that differs from the existing direct vessel injection core cooling system and passive auxiliary feedwater system (PAFS). The heat transfer between the evaporator and condenser sections occurs by phase change of the working fluid and capillary action induced by wick structures installed on the inner wall of the heat pipe. In this study, a hybrid control rod is developed to take the roles of both neutron absorption and heat removal by combining the functions of a heat pipe and control rod. Previous studies on enhancing the heat removal capacity of heat pipes used nanofluids, self-rewetting fluids, various wick structures and condensers. Many studies have examined the thermal performances of heat pipes using various nanofluids. They concluded that the enhanced thermal performance of the heat pipe using nanofluids is due to nanoparticle deposition on the wick structures. Thus, the wick structure of heat pipes has been modified by nanoparticle deposition to enhance the heat removal capacity. However, previous studies used relatively small heat pipes and narrow ranges of heat loads. The environment of a nuclear reactor is very specific, and the decay heat produced by fission products after shutdown is relatively large. Thus, this study tested a large-scale heat pipe over a wide range of power. The concept of a hybrid heat pipe for an advanced in-core decay heat removal system was introduced for complete

  3. Heat Transfer Characteristics of SiC-coated Heat Pipe for Passive Decay Heat Removal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Mo; Kim, In Guk; Jeong, Yeong Shin; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The main concern with the Fukushima accident was the failure of active and passive core cooling systems. The main function of existing passive decay heat removal systems is feeding additional coolant to the reactor core. Thus, an established emergency core cooling system (ECCS) cannot operate properly because of impossible depressurization under the station blackout (SBO) condition. Therefore, a new concept for passive decay heat removal system is required. In this study, an innovative hybrid control rod concept is considered for passive in-core decay heat removal that differs from the existing direct vessel injection core cooling system and passive auxiliary feedwater system (PAFS). The heat transfer between the evaporator and condenser sections occurs by phase change of the working fluid and capillary action induced by wick structures installed on the inner wall of the heat pipe. In this study, a hybrid control rod is developed to take the roles of both neutron absorption and heat removal by combining the functions of a heat pipe and control rod. Previous studies on enhancing the heat removal capacity of heat pipes used nanofluids, self-rewetting fluids, various wick structures and condensers. Many studies have examined the thermal performances of heat pipes using various nanofluids. They concluded that the enhanced thermal performance of the heat pipe using nanofluids is due to nanoparticle deposition on the wick structures. Thus, the wick structure of heat pipes has been modified by nanoparticle deposition to enhance the heat removal capacity. However, previous studies used relatively small heat pipes and narrow ranges of heat loads. The environment of a nuclear reactor is very specific, and the decay heat produced by fission products after shutdown is relatively large. Thus, this study tested a large-scale heat pipe over a wide range of power. The concept of a hybrid heat pipe for an advanced in-core decay heat removal system was introduced for complete

  4. Evaluation of the clinical efficacy of fractional radiofrequency microneedle treatment in acne scars and large facial pores.

    Science.gov (United States)

    Cho, Soo Ick; Chung, Bo Young; Choi, Min Gyu; Baek, Ji Hwoon; Cho, Hee Jin; Park, Chun Wook; Lee, Cheol Heon; Kim, Hye One

    2012-07-01

    Fractional technology overcomes the problems of ablative lasers, such as inaccurate depth control and damage to the epidermis. Minimally invasive fractional radiofrequency microneedle devices allow for more-selective heating of the dermis. To evaluate the clinical efficacy of fractional radiofrequency microneedle (ERM) treatment in acne scars and large facial pores. Thirty patients with acne scars and large facial pores were enrolled. Bipolar radiofrequency energy was delivered to the skin through the electrodes of the FRM device. Skin lesions were evaluated according to grade of acne scars, Investigator Global Assessment of large pores, skin surface roughness, transepidermal water loss (TEWL), dermal density, microscopic and composite image, sebum measurement, and questionnaires regarding patient satisfaction. The grade of acne scars and Investigator Global Assessment of large pores improved in more than 70% of all patients. Skin surface roughness, dermal density, and microscopic and composite images also improved, whereas TEWL and sebum measurement did not change. Clinical improvement from FRM treatment appeared to be related to dermal matrix regeneration. FRM treatment may be effective in improving acne scars and facial pores. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  5. Simulation on Temperature Field of Radiofrequency Lesions System Based on Finite Element Method

    International Nuclear Information System (INIS)

    Xiao, D; Qian, Z; Li, W; Qian, L

    2011-01-01

    This paper mainly describes the way to get the volume model of damaged region according to the simulation on temperature field of radiofrequency ablation lesion system in curing Parkinson's disease based on finite element method. This volume model reflects, to some degree, the shape and size of the damaged tissue during the treatment with all tendencies in different time or core temperature. By using Pennes equation as heat conduction equation of radiofrequency ablation of biological tissue, the author obtains the temperature distribution field of biological tissue in the method of finite element for solving equations. In order to establish damage models at temperature points of 60 deg. C, 65 deg. C, 70 deg. C, 75 deg. C, 80 deg. C, 85 deg. C and 90 deg. C while the time points are 30s, 60s, 90s and 120s, Parkinson's disease model of nuclei is reduced to uniform, infinite model with RF pin at the origin. Theoretical simulations of these models are displayed, focusing on a variety of conditions about the effective lesion size on horizontal and vertical. The results show the binary complete quadratic non-linear joint temperature-time models of the maximum damage diameter and maximum height. The models can comprehensively reflect the degeneration of target tissue caused by radio frequency temperature and duration. This lay the foundation for accurately monitor of clinical RF treatment of Parkinson's disease in the future.

  6. Thermal Response of In Vivo Human Skin to Fractional Radiofrequency Microneedle Device

    Directory of Open Access Journals (Sweden)

    Woraphong Manuskiatti

    2016-01-01

    Full Text Available Background. Fractional radiofrequency microneedle system (FRMS is a novel fractional skin resurfacing system. Data on thermal response to this fractional resurfacing technique is limited. Objectives. To investigate histologic response of in vivo human skin to varying energy settings and pulse stacking of a FRMS in dark-skinned subjects. Methods. Two female volunteers who were scheduled for abdominoplasty received treatment with a FRMS with varying energy settings at 6 time periods including 3 months, 1 month, 1 week, 3 days, 1 day, and the time immediately before abdominoplasty. Biopsy specimens were analyzed using hematoxylin and eosin (H&E, Verhoeff-Van Gieson (VVG, colloidal iron, and Fontana-Masson stain. Immunohistochemical study was performed by using Heat Shock Protein 70 (HSP70 antibody and collagen III monoclonal antibody. Results. The average depth of radiofrequency thermal zone (RFTZ ranged from 100 to 300 μm, correlating with energy levels. Columns of cell necrosis and collagen denaturation followed by inflammatory response were initially demonstrated, with subsequent increasing of mucin at 1 and 3 months after treatment. Immunohistochemical study showed positive stain with HSP70. Conclusion. A single treatment with a FRMS using appropriate energy setting induces neocollagenesis. This wound healing response may serve as a mean to improve the appearance of photodamaged skin and atrophic scars.

  7. Stepwise radiofrequency ablation of Barrett's esophagus preserves esophageal inner diameter, compliance, and motility

    NARCIS (Netherlands)

    Beaumont, H.; Gondrie, J. J.; McMahon, B. P.; Pouw, R. E.; Gregersen, H.; Bergman, J. J.; Boeckxstaens, G. E.

    2009-01-01

    Background and aim: Stepwise endoscopic circumferential and focal radiofrequency ablation is safe and effective for the eradication of Barrett's esophagus. In contrast to other techniques, radiofrequency ablation appears to avoid significant esophageal scarring or stenosis. Our aim was to evaluate

  8. Radiofrequency radiation leakage from microwave ovens

    International Nuclear Information System (INIS)

    Lahham, A.; Sharabati, A.

    2013-01-01

    This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm -1 with an average value equalling 3.64 μW cm -2 . Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm -2 . The highest radiation leakage from any tested oven was ∼16.4 μW cm -2 , and found in two cases only. In no case did the leakage exceed the limit of 1 μWcm -1 recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age. (authors)

  9. Radiofrequency generation by coherently moving fluxons

    Science.gov (United States)

    Dobrovolskiy, O. V.; Sachser, R.; Huth, M.; Shklovskij, V. A.; Vovk, R. V.; Bevz, V. M.; Tsindlekht, M. I.

    2018-04-01

    A lattice of Abrikosov vortices in type II superconductors is characterized by a periodic modulation of the magnetic induction perpendicular to the applied magnetic field. For a coherent vortex motion under the action of a transport current, the magnetic induction at a given point of the sample varies in time with a washboard frequency fWB = v/d, where v is the vortex velocity and d is the distance between the vortices in the direction of motion. Here, by using a spectrum analyzer connected to a 50 nm-wide Au nanowire meander near the surface of a superconducting Nb film, we detect an ac voltage induced by coherently moving fluxons. The voltage is peaked at the washboard frequency, fWB, and its subharmonics, fTOF = fWB/5, determined by the antenna width. By sweeping the dc current value, we reveal that fWB can be tuned from 100 MHz to 1.5 GHz, thereby demonstrating that patterned normal metal/superconductor nanostructures can be used as dc-tunable generators operating in the radiofrequency range.

  10. Spin gymnastics with selective radiofrequency pulses

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, R.; Kupce, E. [Cambridge Univ. (United Kingdom)

    1994-12-31

    Although high resolution NMR spectra are normally excited with short intense radiofrequency pulses, there is an entire family of new experiments that can be performed with frequency-selective or ``soft`` pulses. Time-consuming two-dimensional spectroscopy may be reduced to a much shorter one-dimensional version with much finer digitization in the frequency domain. A large number of soft pulses can be combined to form a ``polychromatic pulse`` that has uniform excitation over the entire range of proton shifts except for a rejection notch at the water frequency. Polychromatic pulses can also be used to create antiphase magnetization in preparation for a coherence transfer or double-quantum experiment. An excitation profile can be designed in the form of a ``template`` that exactly matches the spectrum of a given chemical compound but has zero excitation elsewhere. This is achieved by using the information in the experimental free induction decay to construct a suitable array of soft pulses that has the required excitation pattern. In this manner, interpenetrating spectra can be separated into the spectra of the pure components, for example those of a and b glucose. Selective Hartmann-Hahn coherence transfer experiments employ similar soft pulse techniques. If several such transfers are concatenated, the method may be used as a test to see whether a group of protons is linked in an unbroken chain by scalar spin-spin interactions. (authors). 24 refs., 18 figs.

  11. Radiofrequency ablation for renal tumors. Our experience

    International Nuclear Information System (INIS)

    Hiraoka, Kenji; Kawauchi, Akihiro; Nakamura, Terukazu; Soh, Jintetsu; Mikami, Kazuya; Miki, Tsuneharu

    2009-01-01

    The objective of this study was to report our results of percutaneous radiofrequency ablation (RFA) for renal tumors and to assess predictors of therapeutic efficacy. Forty patients (median age 73 years) with renal tumors were treated with RFA under local or epidural anesthesia. All of them had high surgical risk or refused radical surgery. Tumors were punctured percutaneously using the Radionics Cool-tip RF System under computed tomography or ultrasonographic guidance. Median tumor diameter was 24 mm. After RFA, contrast-enhanced computed tomography or magnetic resonance imaging was performed within 1 month. Complete response (CR) was defined as no enhancement inside the tumor. Factors related to the outcome and to renal function were assessed. Median follow up was 16 months. CR was observed in 34 cases (85.0%). A significant difference in CR rate was observed between tumors ≤30 mm and those >30 mm. Outcomes tended to be better for tumors in the mid to lower kidney, and those away from the renal hilum. Recurrence was observed in one case (2.9%), but a CR was obtained again by additional RFA. Out of a total of 77 RFA procedures, complications occurred in only three cases (3.9%), and conservative treatment was possible in all cases. Serum creatinine levels 3 months after RFA did not differ from those before RFA. Percutaneous RFA is a safe and effective treatment for small renal tumors in patients with high surgical risk or who refuse radical surgery. (author)

  12. Radio-frequency plasma spraying of ceramics

    International Nuclear Information System (INIS)

    Okada, T.; Hamatani, H.; Yoshida, T.

    1989-01-01

    This study was aimed at developing a novel spraying process using a radio-frequency (rf) plasma. Experiments of Al 2 O 3 and ZrO 2 - 8 wt% Y 2 O 3 spraying showed that the initial powder size was the most important parameter for depositing dense coatings. The optimum powder sizes of Al 2 O 3 and ZrO 2 - 8 wt% Y 2 O 3 were considered to be around 100 and 80 μm, respectively. The use of such large-size powders compared with those used by conventional dc plasma spraying made it possible to deposit adherent ceramics coatings of 150 to 300 μm on as-rolled SS304 substrates. It was also shown that low particle velocity of about 10 m/s, which is peculiar to rf plasma spraying, was sufficient for particle deformation, though it imposed a severe limitation on the substrate position. These experimental results prove that rf plasma spraying is an effective process and a strong candidate to open new fields of spraying applications

  13. Characterization of tracked radiofrequency ablation in phantom

    International Nuclear Information System (INIS)

    Chen, Chun-Cheng R.; Miga, Michael I.; Galloway, Robert L.

    2007-01-01

    In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized. To study the use of computational models of RFA in planning needle placement, this work compared ablations performed with an optically tracked RFA device with corresponding models of the ablations. The calibration of the tracked device allowed the positions of distal features of the device, particularly the tips of the needle electrodes, to be determined to within 1.4±0.6 mm of uncertainty. Ablations were then performed using the tracked device in a phantom system based on an agarose-albumin mixture. Images of the sliced phantom obtained from the ablation experiments were then compared with the predictions of a bioheat transfer model of RFA, which used the positional data of the tracked device obtained during ablation. The model was demonstrated to predict 90% of imaged pixels classified as being ablated. The discrepancies between model predictions and observations were analyzed and attributed to needle tracking inaccuracy as well as to uncertainties in model parameters. The results suggest the feasibility of using finite element modeling to plan ablations with predictable outcomes when implemented using tracked RFA

  14. VLTI First Fringes with Two Auxiliary Telescopes at Paranal

    Science.gov (United States)

    2005-03-01

    World's Largest Interferometer with Moving Optical Telescopes on Track Summary The Very Large Telescope Interferometer (VLTI) at Paranal Observatory has just seen another extension of its already impressive capabilities by combining interferometrically the light from two relocatable 1.8-m Auxiliary Telescopes. Following the installation of the first Auxiliary Telescope (AT) in January 2004 (see ESO PR 01/04), the second AT arrived at the VLT platform by the end of 2004. Shortly thereafter, during the night of February 2 to 3, 2005, the two high-tech telescopes teamed up and quickly succeeded in performing interferometric observations. This achievement heralds an era of new scientific discoveries. Both Auxiliary Telescopes will be offered from October 1, 2005 to the community of astronomers for routine observations, together with the MIDI instrument. By the end of 2006, Paranal will be home to four operational ATs that may be placed at 30 different positions and thus be combined in a very large number of ways ("baselines"). This will enable the VLTI to operate with enormous flexibility and, in particular, to obtain extremely detailed (sharp) images of celestial objects - ultimately with a resolution that corresponds to detecting an astronaut on the Moon. PR Photo 07a/05: Paranal Observing Platform with AT1 and AT2 PR Photo 07b/05: AT1 and AT2 with Open Domes PR Photo 07c/05: Evening at Paranal with AT1 and AT2 PR Photo 07d/05: AT1 and AT2 under the Southern Sky PR Photo 07e/05: First Fringes with AT1 and AT2 PR Video Clip 01/05: Two ATs at Paranal (Extract from ESO Newsreel 15) A Most Advanced Device ESO PR Video 01/05 ESO PR Video 01/05 Two Auxiliary Telescopes at Paranal [QuickTime: 160 x 120 pix - 37Mb - 4:30 min] [QuickTime: 320 x 240 pix - 64Mb - 4:30 min] ESO PR Photo 07a/05 ESO PR Photo 07a/05 [Preview - JPEG: 493 x400 pix - 44k] [Normal - JPEG: 985 x 800 pix - 727k] [HiRes - JPEG: 5000 x 4060 pix - 13.8M] Captions: ESO PR Video Clip 01/05 is an extract from

  15. Operation of the main feedwater system turbopump following plant trip with total failure of the auxiliary feedwater system

    International Nuclear Information System (INIS)

    Lucas Alvaro, A.M. de; Rosa Martinez, B. de la; Alcaide, F.; Toledano Camara, C.

    1993-01-01

    The Auxiliary Feedwater System (AF) is a safeguard system which has been designed to supply feedwater to the steam generators, cool the primary system and remove decay heat from the reactor when the main feedwater pumps fail due to loss of power or any other reason. Thus, when plant trip occurs, the AF system pumps start up automatically, allowing removal of decay heat from the reactor. However, even though this system (2 motor-driven pumps and 1 turbopump) is highly reliable, injection of water to the steam generators must be ensured when it fails completely. To do this, if plant trip has not been caused by loss of off site power or failure of the Main Feedwater System (FW) turbopumps, one of these turbopumps can be used to achieve removal of decay heat. Since a large amount of steam is consumed by these turbopumps, an analysis has been performed to determine whether one of these pumps can be used and what actions are necessary to inject water into the steam generators. Results show that, for the case in question, a FW turbopump can be used to remove decay heat from the reactor. (author)

  16. Auxiliary equipment for cooling water in a reactor

    International Nuclear Information System (INIS)

    Konno, Yasuhiro; Sakairi, Toshiaki.

    1975-01-01

    Object: To effectively make use of pressure energy of reactor water, which has heretofore been discarded, to enable supply of emergency power supply of high reliability and to prevent spreading of environmental contamination. Structure: Sea water pumped by a sea water supply pump is fed to a heat exchanger. Reactor water carried through piping on the side to be cooled is removed in heat by the heat exchanger to be cooled and returned, and then again returned to the reactor. On the other hand, sea water heated by the heat exchanger is fed to a water wheel to drive the water wheel, after which it is discharged into a discharging path. A generator may be directly connected to the water wheel to use the electricity generated by the generator as the emergency power source. (Kamimura, M.)

  17. Systematic Review of Radiofrequency Ablation and Pulsed Radiofrequency for Management of Cervicogenic Headaches.

    Science.gov (United States)

    Grandhi, Ravi K; Kaye, Alan David; Abd-Elsayed, Alaa

    2018-02-23

    Cervicogenic headache (CHA) is a secondary headache which has a source in the upper cervical spine. Many traditional analgesic choices lack good efficacy in managing the associated pain. As a result, in management of CHA, radiofrequency ablation (RFA) or pulse radiofrequency (PRF) has been tried with success. Our study investigated the use of RFA and PRF for the management of CHA. In the present investigation, a review of the literature was conducted using PubMed (1966 to February 2017). The quality assessment was determined using The Cochrane Risk of Bias. After initial search and consultation with experts, 34 articles were identified for initial review and 10 articles met inclusion for review. Criteria for inclusion were primarily based on identification of articles discussing cervicogenic headaches which were previously treatment resistant and occurred without any other pathology of the craniofacial region or inciting event such as trauma. This systematic review demonstrated that RFA and PRFA provide very limited benefit in the management of CHA. At present, there is no high-quality RCT and/or strong non-RCTs to support the use of these techniques, despite numerous case reports which have demonstrated benefit. This review is one of the first to provide a comprehensive overview of the use of RFA and PRF in the management of CHA.

  18. Symplicity multi-electrode radiofrequency renal denervation system feasibility study.

    Science.gov (United States)

    Whitbourn, Robert; Harding, Scott A; Walton, Antony

    2015-05-01

    The aim of this study was to test the safety and performance of the Symplicity™ multi-electrode radio-frequency renal denervation system which was designed to reduce procedure time during renal denervation. The multi-electrode radiofrequency renal denervation system feasibility study is a prospective, non-randomised, open label, feasibility study that enrolled 50 subjects with hypertension. The study utilises a new renal denervation catheter which contains an array of four electrodes mounted in a helical configuration at 90 degrees from each other to deliver radiofrequency energy simultaneously to all four renal artery quadrants for 60 seconds. The protocol specified one renal denervation treatment towards the distal end of each main renal artery with radiofrequency energy delivered for 60 seconds per treatment. Total treatment time for both renal arteries was two minutes. The 12-month change in office systolic blood pressure (SBP) and 24-hour SBP was -19.2±25.2 mmHg, prenal artery stenosis or hypertensive emergencies occurred. The Symplicity multi-electrode radiofrequency renal denervation system was associated with a significant reduction in SBP at 12 months and minimal complications whilst it also reduced procedure time. NCT01699529.

  19. Radiofrequency for the treatment of skin laxity: mith or truth*

    Science.gov (United States)

    de Araújo, Angélica Rodrigues; Soares, Viviane Pinheiro Campos; da Silva, Fernanda Souza; Moreira, Tatiane da Silva

    2015-01-01

    The nonablative radiofrequency is a procedure commonly used for the treatment of skin laxity from an increase in tissue temperature. The goal is to induce thermal damage to thus stimulate neocollagenesis in deep layers of the skin and subcutaneous tissue. However, many of these devices haven't been tested and their parameters are still not accepted by the scientific community. Because of this, it is necessary to review the literature regarding the physiological effects and parameters for application of radiofrequency and methodological quality and level of evidence of studies. A literature search was performed in MEDLINE, PEDro, SciELO, PubMed, LILACS and CAPES and experimental studies in humans, which used radiofrequency devices as treatment for facial or body laxity, were selected. The results showed that the main physiological effect is to stimulate collagen synthesis. There was no homogeneity between studies in relation to most of the parameters used and the methodological quality of studies and level of evidence for using radiofrequency are low. This fact complicates the determination of effective parameters for clinical use of this device in the treatment of skin laxity. The analyzed studies suggest that radiofrequency is effective, however the physiological mechanisms and the required parameters are not clear in the literature. PMID:26560216

  20. Treatment of acne vulgaris with fractional radiofrequency microneedling.

    Science.gov (United States)

    Kim, Sang Tae; Lee, Kang Hoon; Sim, Hyung Jun; Suh, Kee Suck; Jang, Min Soo

    2014-07-01

    Fractional radiofrequency microneedling is a novel radiofrequency technique that uses insulated microneedles to deliver energy to the deep dermis at the point of penetration without destruction of the epidermis. It has been used for the treatment of various dermatological conditions including wrinkles, atrophic scars and hypertrophic scars. There have been few studies evaluating the efficacy of fractional radiofrequency microneedling in the treatment of acne, and none measuring objective parameters like the number of inflammatory and non-inflammatory acne lesions or sebum excretion levels. The safety and efficacy of fractional radiofrequency microneedling in the treatment of acne vulgaris was investigated. In a prospective clinical trial, 25 patients with moderate to severe acne were treated with fractional radiofrequency microneedling. The procedure was carried out three times at 1-month intervals. Acne lesion count, subjective satisfaction score, sebum excretion level and adverse effects were assessed at baseline and at 4, 8 and 12 weeks after the first treatment as well as 4, 8 and 12 weeks after the last treatment. Number of acne lesions (inflammatory and non-inflammatory) decreased. Sebum excretion and subjective satisfaction were more favorable at every time point compared with the baseline values (P acne vulgaris. © 2014 Japanese Dermatological Association.