Science.gov

Sample records for 1850-1990 mhz 2110-2150

  1. 47 CFR 101.69 - Transition of the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands from the fixed microwave...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., and 2160-2200 MHz bands from the fixed microwave services to personal communications services and...) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers... MHz bands from the fixed microwave services to personal communications services and...

  2. 47 CFR 101.69 - Transition of the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands from the fixed microwave...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., and 2160-2200 MHz bands from the fixed microwave services to personal communications services and...) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers... MHz bands from the fixed microwave services to personal communications services and...

  3. 47 CFR 101.69 - Transition of the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands from the fixed microwave...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., and 2160-2200 MHz bands from the fixed microwave services to personal communications services and...) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers... MHz bands from the fixed microwave services to personal communications services and...

  4. 47 CFR 101.69 - Transition of the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands from the fixed microwave...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., and 2160-2200 MHz bands from the fixed microwave services to personal communications services and...) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers... MHz bands from the fixed microwave services to personal communications services and...

  5. 47 CFR 27.1111 - Relocation of fixed microwave service licensees in the 2110-2150 and 2160-2200 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Relocation of fixed microwave service licensees... Incumbents § 27.1111 Relocation of fixed microwave service licensees in the 2110-2150 and 2160-2200 MHz bands... of incumbent fixed microwave service licensees in the 2110-2150 MHz and 2160-2200 MHz bands. [79...

  6. 47 CFR 27.1111 - Relocation of fixed microwave service licensees in the 2110-2150 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Relocation of fixed microwave service licensees... fixed microwave service licensees in the 2110-2150 MHz band. Part 22, subpart E and part 101, subpart B of this chapter contain provisions governing the relocation of incumbent fixed microwave...

  7. 47 CFR 101.69 - Transition of the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands from the fixed microwave...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (PCS), Advanced Wireless Services (AWS), and Mobile Satellite Services (MSS). The rules in this section... frequencies to other media or other fixed channels, including those in other microwave bands. (a) ET...

  8. 47 CFR 27.1111 - Relocation of fixed microwave service licensees in the 2110-2150 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Relocation of fixed microwave service licensees..., 2110-2155 MHz, 2160-2180 MHz Bands Relocation of Incumbents § 27.1111 Relocation of fixed microwave... contain provisions governing the relocation of incumbent fixed microwave service licensees in the...

  9. 47 CFR 27.1111 - Relocation of fixed microwave service licensees in the 2110-2150 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Relocation of fixed microwave service licensees..., 2110-2155 MHz, 2160-2180 MHz Bands Relocation of Incumbents § 27.1111 Relocation of fixed microwave... contain provisions governing the relocation of incumbent fixed microwave service licensees in the...

  10. 47 CFR 27.1111 - Relocation of fixed microwave service licensees in the 2110-2150 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Relocation of fixed microwave service licensees..., 2110-2155 MHz, 2160-2180 MHz Bands Relocation of Incumbents § 27.1111 Relocation of fixed microwave... contain provisions governing the relocation of incumbent fixed microwave service licensees in the...

  11. 47 CFR 101.82 - Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... between AWS and MSS (space-to-Earth downlink). Whenever an ET licensee (AWS or Mobile Satellite Service for space-to-Earth downlink in the 2130-2150 or 2180-2200 MHz bands) relocates an incumbent paired... section from any other AWS licensee or MSS space-to-Earth downlink operator which would have been...

  12. 47 CFR 101.82 - Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... between AWS and MSS (space-to-Earth downlink). Whenever an ET licensee (AWS or Mobile Satellite Service for space-to-Earth downlink in the 2130-2150 or 2180-2200 MHz bands) relocates an incumbent paired... section from any other AWS licensee or MSS space-to-Earth downlink operator which would have been...

  13. 47 CFR 101.82 - Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... between AWS and MSS (space-to-Earth downlink). Whenever an ET licensee (AWS or Mobile Satellite Service... among terrestrial stations. For terrestrial stations (AWS and MSS Ancillary Terrestrial Component (ATC..., that MSS operators (including MSS/ATC operators) are not obligated to reimburse voluntarily...

  14. 47 CFR 101.82 - Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... between AWS and MSS (space-to-Earth downlink). Whenever an ET licensee (AWS or Mobile Satellite Service... among terrestrial stations. For terrestrial stations (AWS and MSS Ancillary Terrestrial Component (ATC..., that MSS operators (including MSS/ATC operators) are not obligated to reimburse voluntarily...

  15. Assessing historical global sulfur emission patterns for the period 1850--1990

    SciTech Connect

    Lefohn, A.S.; Husar, J.D.; Husar, R.B.; Brimblecombe, P.

    1996-07-19

    Anthropogenic sulfur dioxide emissions from energy-producing and metal production activities have become an important factor in better understanding the relationship between humans and the environment. Concerns about (1) acid rain effects on the environment and (2) anthropogenic aerosols affecting possible global change have prompted interest in the transformation and fate of sulfur in the environment. One step in assessing the importance of sulfur emissions is the development of a reliable regional emission inventory of sulfur as a function of time. The objective of this research effort was to create a homogeneous database for historical sulfur emission estimates for the world. The time from 1850--1990 was selected to include the period of industrialization form the time the main production of fuels and minerals began until the most recent year for which complete production data exist. This research effort attempts to correct some of the deficiencies associated with previous global sulfur emission estimates by (1) identifying those production activities that resulted in sulfur emissions by country and (2) calculating historical emission trends by country across years. An important component of this study was the comparison of the sulfur emission results with those of previous studies.

  16. 47 CFR 27.1166 - Reimbursement under the Cost-Sharing Plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Cost-Sharing Policies Governing Microwave Relocation from the 2110-2150 Mhz and 2160-2200 Mhz Bands... microwave incumbent a monetary sum to relocate its own facilities, the AWS relocator must estimate the...

  17. 47 CFR 27.1172 - Dispute Resolution Under the Cost-Sharing Plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MHz Bands Cost-Sharing Policies Governing Microwave Relocation from the 2110-2150 Mhz and 2160-2200... provide evidentiary support to demonstrate that their calculation is reasonable and made in good...

  18. 47 CFR 27.1162 - Administration of the Cost-Sharing Plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Administration of the Cost-Sharing Plan. 27... Cost-Sharing Policies Governing Microwave Relocation from the 2110-2150 Mhz and 2160-2200 Mhz Bands § 27.1162 Administration of the Cost-Sharing Plan. The Wireless Telecommunications Bureau,...

  19. 47 CFR 27.1168 - Triggering a Reimbursement Obligation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Policies Governing Microwave Relocation from the 2110-2150 Mhz and 2160-2200 Mhz Bands § 27.1168 Triggering... relocator, MSS relocator (including MSS/ATC), or a voluntarily relocating microwave incumbent in accordance with the formula detailed in § 27.1164: (1) All or part of the relocated microwave link was...

  20. 47 CFR 101.73 - Mandatory negotiations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE... premium is directly related to relocation, such as system-wide relocations and analog-to-digital... Microwave Licensees in the 2110-2150 and 2160-2200 MHz bands. A separate mandatory negotiation period...

  1. 47 CFR 101.73 - Mandatory negotiations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE... premium is directly related to relocation, such as system-wide relocations and analog-to-digital... Microwave Licensees in the 2110-2150 and 2160-2200 MHz bands. A separate mandatory negotiation period...

  2. Spinsters, Bachelors, and Other Gender Transgressors in School Employment, 1850-1990.

    ERIC Educational Resources Information Center

    Blount, Jackie

    2000-01-01

    Traces the history and experiences of some educators who have transcended gender stereotypes. Presents a historical analysis of how fear of homosexuality emerged among educators and the public and how homophobia has permeated rigid gender-defined roles in school employment. (SLD)

  3. 805 MHz and 201 MHz RF cavity development for MUCOOL

    SciTech Connect

    DLi@lbl.gov

    2002-10-10

    A muon cooling channel calls for very high acceleratinggradient RF structures to restore the energy lost by muons in theabsorbers. The RF structures have to be operated in a strong magneticfield and thus the use of superconducting RF cavities is excluded. Toachieve a high shunt impedance while maintaining a large enough apertureto accommodate a large transverse emittance muon beam, the cavity designadopted is a pillbox-like geometry with thin Be foils to terminate theelectromagnetic field at the cavity iris. The possibility of using gridsof thin-walled metallic tubes for the termination is also being explored.Many of the RF-related issues for muon cooling channels are being studiedboth theoretically and experimentally using an 805 MHz cavity that has apillbox-like geometry with thin Be windows to terminate the cavityaperture. The design and performance of this cavity are reported here.High-power RF tests of the 805 MHz cavity are in progress at Lab G inFermilab. The cavity has exceeded its design gradient of 30 MV/m,reaching 34 MV/m without external magnetic field. No surface damage wasobserved at this gradient. The cavity is currently under conditioning atLab G with an external magnetic field of 2.5 T. We also present here a201 MHz cavity design for muoncooling channels. The proposed cavitydesign is also suitable for use in a proof-of-principle Muon IonizationCooling Experiment (MICE).

  4. 47 CFR 24.249 - Payment issues.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES Broadband PCS Policies Governing Microwave Relocation from the 1850-1990 Mhz Band § 24.249 Payment... directly to the PCS relocator or the voluntarily relocating microwave incumbent the amount owed...

  5. 47 CFR 24.249 - Payment issues.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES Broadband PCS Policies Governing Microwave Relocation from the 1850-1990 Mhz Band § 24.249 Payment... directly to the PCS relocator or the voluntarily relocating microwave incumbent the amount owed...

  6. 47 CFR 24.249 - Payment issues.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES Broadband PCS Policies Governing Microwave Relocation from the 1850-1990 Mhz Band § 24.249 Payment... directly to the PCS relocator or the voluntarily relocating microwave incumbent the amount owed...

  7. 47 CFR 27.1101 - 1710-1755 MHz and 2110-2155 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false 1710-1755 MHz and 2110-2155 MHz bands subject to competitive bidding. 27.1101 Section 27.1101 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... MHz, 2160-2180 MHz Bands Licensing and Competitive Bidding Provisions § 27.1101 1710-1755 MHz and...

  8. 47 CFR 27.17 - Discontinuance of service in the 1695-1710 MHz, 1755-1780 MHz, 1915-1920 MHz, 1995-2000 MHz, 2000...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... private, internal communications regulatory status that hold 600 MHz band authorizations or AWS....17 Section 27.17 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Applications and Licenses § 27.17 Discontinuance...

  9. The ionospheric refraction at 38 MHz.

    NASA Astrophysics Data System (ADS)

    Milogradov-Turin, J.

    The investigation of the observed shift of the North Polar Spur (NPS) at the 38 MHz survey of Milogradov-Turin and Smith (1973) in respect to the position of the NPS on the survey at 408 MHz convolved to the same resolution (Haslam and Salter 1977) has shown that there is no dependence of the NPS position on frequency and that the ionospheric refraction should be larger than believed.

  10. Providing primary standard calibrations beyond 20 MHz

    NASA Astrophysics Data System (ADS)

    Bickley, C. J.; Zeqiri, B.; Robinson, S. P.

    2004-01-01

    The number of applications of medical ultrasound utilising frequencies in excess of 20 MHz has shown a consistent increase over recent years. Coupled with the commercial availability of wide-bandwidth hydrophones whose response extends beyond 40 MHz, this has driven a growing need to develop hydrophone calibration techniques at elevated frequencies. The current National Physical Laboratory primary standard method of calibrating hydrophones is based on an optical interferometer. This has been in operation for around 20 years and provides traceability over the frequency range of 0.3 to 20 MHz. More recently, calibrations carried out using the interferometer have been extended to 60 MHz, although the uncertainties associated with these calibrations are poor, being in excess of +/-20% at high frequencies. Major contributions to the degraded calibration uncertainties arise from poor signal-to-noise at higher frequencies, the frequency response of the photodiodes used and the noise floor of the instrument. To improve the uncertainty of hydrophone calibrations above 20 MHz, it has been necessary to build and commission a new interferometer. Important features of the new primary standard are its use of a higher power laser to improve the signal-to-noise ratio, along with photodiodes whose greater bandwidth to improve the overall frequency response. This paper describes the design of key aspects of the new interferometer. It also presents some initial results of the performance assessment, including a detailed comparison of calibrations of NPL reference membrane hydrophones, undertaken using old and new interferometers for calibration up to 40 MHz.

  11. Non-thermal effects of 500MHz - 900MHz microwave radiation on enzyme kinetics.

    PubMed

    Pirogova, E; Vojisavljevic, V; Cosic, I

    2008-01-01

    Enzymes are essential for the catalysis of biochemical reactions and in the regulation of metabolic pathways. They function by greatly accelerating the rate of specific chemical reactions that would otherwise be slow. It has been shown that extremely low-power microwaves can influence enzyme activity [1-5]. This study is focused at investigating the effects of low level microwave exposures ranging from 500MHz to 900MHz on L-Lactate Dehydrogenase (LDH) enzyme activity. The results obtained revealed the increased bioactivity of the LDH upon microwave radiation at two particular frequencies 500MHz and 900MHz.

  12. 20 MHz/40 MHz Dual Element Transducers for High Frequency Harmonic Imaging

    PubMed Central

    Kim, Hyung Ham; Cannata, Jonathan M.; Liu, Ruibin; Chang, Jin Ho; Silverman, Ronald H.; Shung, K. Kirk

    2009-01-01

    Concentric annular type dual element transducers for second harmonic imaging at 20 MHz / 40 MHz were designed and fabricated to improve spatial resolution and depth of penetration for ophthalmic imaging applications. The outer ring element was designed to transmit the 20 MHz signal and the inner circular element was designed to receive the 40 MHz second harmonic signal. Lithium niobate (LiNbO3), with its low dielectric constant, was used as the piezoelectric material to achieve good electrical impedance matching. Double matching layers and conductive backing were used and optimized by KLM modeling to achieve high sensitivity and wide bandwidth for harmonic imaging and superior time-domain characteristics. Prototype transducers were fabricated and evaluated quantitatively and clinically. The average measured center frequency for the transmit ring element was 21 MHz and the one-way –3 dB bandwidth was greater than 50%. The 40 MHz receive element functioned at 31 MHz center frequency with acceptable bandwidth to receive attenuated and frequency downshifted harmonic signal. The lateral beam profile for the 20 MHz ring elements at the focus matched the Field II simulated results well, and the effect of outer ring diameter was also examined. Images of a posterior segment of an excised pig eye and a choroidal nevus of human eye were obtained both for single element and dual element transducers and compared to demonstrate the advantages of dual element harmonic imaging. PMID:19126492

  13. Analyses of 476 MHz and 952 MHz Crab Cavities for JLAB Electron Ion Collider

    SciTech Connect

    Park, HyeKyoung; Castilla, Alejandro; Delayen, Jean R.; De Silva, Subashini U.; Morozov, Vasiliy

    2016-05-01

    The Center for Accelerator Science at Old Dominion University has designed, fabricated and successfully tested a crab cavity for Electron Ion Collider at Jefferson Lab (JLEIC) [1]. This proof-of-principle cavity was based on the earlier MEIC design which used 748.5 MHz RF system. The updated JLEIC (called MEIC earlier) design [2] utilizes the components from PEP-II. It results in the change on the bunch repetition rate of stored beam to 476.3 MHz. The ion ring collider will eventually require 952.6 MHz crab cavities. This paper will present the analyses of crab cavities of both 476 MHz and 952 MHz options. It compares advantages and disadvantages of the options which provide the JLEIC design team important technical information for a system down selection.

  14. 47 CFR 27.1102 - Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2110-2155 MHz bands. 27.1102 Section 27.1102 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155... the 1710-1755 MHz and 2110-2155 MHz bands. (a) Eligibility for small business provisions. (1) A...

  15. 47 CFR 27.501 - 746-758 MHz, 775-788 MHz, and 805-806 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false 746-758 MHz, 775-788 MHz, and 805-806 MHz bands subject to competitive bidding. 27.501 Section 27.501 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive...

  16. 47 CFR 27.501 - 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding. 27.501 Section 27.501 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive...

  17. 47 CFR 27.501 - 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding. 27.501 Section 27.501 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive...

  18. 47 CFR 27.501 - 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding. 27.501 Section 27.501 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive...

  19. 47 CFR 15.231 - Periodic operation in the band 40.66-40.70 MHz and above 70 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Periodic operation in the band 40.66-40.70 MHz... Periodic operation in the band 40.66-40.70 MHz and above 70 MHz. (a) The provisions of this section are restricted to periodic operation within the band 40.66-40.70 MHz and above 70 MHz. Except as shown...

  20. The NATO III 5 MHz Distribution System

    NASA Technical Reports Server (NTRS)

    Vulcan, A.; Bloch, M.

    1981-01-01

    A high performance 5 MHz distribution system is described which has extremely low phase noise and jitter characteristics and provides multiple buffered outputs. The system is completely redundant with automatic switchover and is self-testing. Since the 5 MHz reference signals distributed by the NATO III distribution system are used for up-conversion and multiplicative functions, a high degree of phase stability and isolation between outputs is necessary. Unique circuit design and packaging concepts insure that the isolation between outputs is sufficient to quarantee a phase perturbation of less than 0.0016 deg when other outputs are open circuited, short circuited or terminated in 50 ohms. Circuit design techniques include high isolation cascode amplifiers. Negative feedback stabilizes system gain and minimizes circuit phase noise contributions. Balanced lines, in lieu of single ended coaxial transmission media, minimize pickup.

  1. 47 CFR 27.1102 - Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands. 27.1102 Section 27.1102 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz,...

  2. 47 CFR 27.1102 - Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands. 27.1102 Section 27.1102 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz,...

  3. 47 CFR 27.1101 - 1710-1755 MHz and 2110-2155 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false 1710-1755 MHz and 2110-2155 MHz bands subject to competitive bidding. 27.1101 Section 27.1101 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz,...

  4. 47 CFR 27.1001 - 1915-1920 MHz and 1995-2000 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false 1915-1920 MHz and 1995-2000 MHz bands subject to competitive bidding. 27.1001 Section 27.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1915-1920 MHz and...

  5. Miniaturized bendable 400 MHz artificial magnetic conductor

    NASA Astrophysics Data System (ADS)

    Presse, Anthony; Tarot, Anne-Claude

    2016-04-01

    A bendable artificial magnetic conductor (AMC) with a resonant frequency of 400 MHz is proposed. The dimensions of the unit cell are 50 × 50 mm2 or 0.07 × 0.07 λ0. The miniaturization is achieved with closely coupled patches printed on each side of a 0.127-mm-thick dielectric substrate. This last one is stacked on a flexible 3-mm-thick silicone over a ground plane. An AMC prototype is simulated and manufactured. Also, a printed inverted-F antenna is used to highlight the bandwidth of the AMC.

  6. Superconducting 112 MHz QWR electron gun

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Boulware, C.H.; Chang, X.; Grimm, T.L.; Rao, T.; Siegel, B.; Skaritka, J.; Than, R.; Winowski, M.; Wu, Q.; Xin, T.; Xue, L.

    2011-07-25

    Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electron cooling hadron beams in RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline our plans. This gun will also serve as a prototype for a future SRF gun to be used for coherent electron cooling of hadrons in eRHIC.

  7. Frequency Arrangement For 700 MHz Band

    NASA Astrophysics Data System (ADS)

    Ancans, G.; Bobrovs, V.; Ivanovs, G.

    2015-02-01

    The 694-790 MHz (700 MHz) band was allocated by the 2012 World Radiocommunication Conference (WRC-12) in ITU Region 1 (Europe included), to the mobile service on a co-primary basis with other services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT). At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15). In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.

  8. TEM Cell Testing of Cable Noise Reduction Techniques from 2 MHz to 200 MHz -- Part 2

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur T.; Evans, William C.; Reed, Joshua L.; Shimp, Samuel K., III; Fitzpatrick, Fred D.

    2008-01-01

    This paper presents empirical results of cable noise reduction techniques as demonstrated in a TEM cell operating with radiated fields from 2 - 200 MHz. It is the second part of a two-paper series. The first paper discussed cable types and shield connections. In this second paper, the effects of load and source resistances and chassis connections are examined. For each topic, well established theories are compared to data from a real-world physical system. Finally, recommendations for minimizing cable susceptibility (and thus cable emissions) are presented. There are numerous papers and textbooks that present theoretical analyses of cable noise reduction techniques. However, empirical data is often targeted to low frequencies (e.g. <50 KHz) or high frequencies (>100 MHz). Additionally, a comprehensive study showing the relative effects of various noise reduction techniques is needed. These include the use of dedicated return wires, twisted wiring, cable shielding, shield connections, changing load or source impedances, and implementing load- or source-to-chassis isolation. We have created an experimental setup that emulates a real-world electrical system, while still allowing us to independently vary a host of parameters. The goal of the experiment was to determine the relative effectiveness of various noise reduction techniques when the cable is in the presence of radiated emissions from 2 MHz to 200 MHz.

  9. 47 CFR 15.247 - Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., whichever is greater. Alternatively, frequency hopping systems operating in the 2400-2483.5 MHz band may... bandwidth of the hopping channel, whichever is greater, provided the systems operate with an output power no... synchronization with the transmitted signals. (i) For frequency hopping systems operating in the 902-928 MHz...

  10. A 300-MHz digitally compensated SAW oscillator.

    PubMed

    Cowan, W D; Slobodnik, A R; Roberts, G A; Silva, J H

    1988-01-01

    A method for compensating for the inherent temperature sensitivity of surface-acoustic-wave (SAW) oscillators is described. Results for a 300-MHz digitally compensated SAW oscillator (DCSO) show a reduction of temperature-induced frequency variation from +/-125 parts per million to +/-1.4 parts per million over the temperature range of -23 to 75 degrees C. This is accomplished using simple digital circuitry and microprocessor control. The temperature-sensing scheme, using a SAW structure with two delay paths of different temperature sensitivity on the same AT-cut quartz substrate, virtually eliminates thermal resistance and time-constant problems. Advantages over ovenized systems include fast warmup; reduced size, weight, and power dissipation; low cost potential; and the ability to compensate for other sources of frequency drift.

  11. BNL 703 MHz SRF cryomodule demonstration

    SciTech Connect

    Burrill,A.; Ben-Zvi, I.; Calaga, R.; Dalesio, L.; Dottavio, T.; Gassner, D.; Hahn, H.; Hoff, L.; Kayran, D.; Kewisch, J.; Lambiase, R.; Lederle, d.; Litvinenko, v.; Mahler, G.; McIntyre, G.; et al.

    2009-05-04

    This paper will present the preliminary results of the testing of the 703 MHz SRF cryomodule designed for use in the ampere class ERL under construction at Brookhaven National Laboratory. The preliminary cavity tests, carried out at Thomas Jefferson Laboratory, demonstrated cavity performance of 20 MV/m with a Qo of 1 x 10{sup 10}, results we expect to reproduce in the horizontal configuration. This test of the entire string assembly will allow us to evaluate all of the additional cryomodule components not previously tested in the VTA and will prepare us for our next milestone test which will be delivery of electrons from our injector through the cryomodule to the beam dump. This will also be the first demonstration of an accelerating cavity designed for use in an ampere class ERL, a key development which holds great promise for future machines.

  12. Compact Miniaturized Antenna for 210 MHz RFID

    NASA Technical Reports Server (NTRS)

    Lee, Richard Q.; Chun, Kue

    2008-01-01

    This paper describes the design and simulation of a miniaturized square-ring antenna. The miniaturized antenna, with overall dimensions of approximately one tenth of a wavelength (0.1 ), was designed to operate at around 210 MHz, and was intended for radio-frequency identification (RFID) application. One unique feature of the design is the use of a parasitic element to improve the performance and impedance matching of the antenna. The use of parasitic elements to enhance the gain and bandwidth of patch antennas has been demonstrated and reported in the literature, but such use has never been applied to miniaturized antennas. In this work, we will present simulation results and discuss design parameters and their impact on the antenna performance.

  13. Shift Register Clock Rate Effects on Coincidence Collection 50MHz versus 4MHz Comparison Tests

    SciTech Connect

    Newell, Matthew R.; Bourret, Steven C.; Swinhoe, Martyn Thomas

    2015-11-03

    The following report identifies and quantifies the timing differences between the older slower Shift Register Coincidence/Multiplicity modules and today’s modern higher speed devices. Modern high speed Shift Register Coincidence/Multiplicity instruments employ high speed internal clocks that run at frequencies more than ten times the older units, typically 50MHz. These higher speed clocks allow for a finer time resolution when recording input pulses.

  14. Propagation of Signals in the Frequency Band Between 30 MHz and 100 MHz.

    DTIC Science & Technology

    1985-09-01

    constant (Dolukhanov, 1971). The net effect of these differences is to produce a larger scattered field. Because narrowbeam antennas limit the spread...that limiting sporadic E propagation to frequencies less than 60 MHz is almost certainly too strict a constraint. However, the mechanism of propagation...with scattering angle effectively limits the minimum range over which communication is possible. The spread in arrival times and, hence, the bandwidth is

  15. Analysis of the 425-MHz Klystrode

    NASA Astrophysics Data System (ADS)

    Nguyen, K.; Warren, Gary D.; Ludeking, L.; Goplen, Bruce

    1991-10-01

    The results of analyses performed on a 500-kW peak power, 425-MHz Klystrode are presented. The Klystrode is an RF amplifier with three basic components; a gated-emission gun, a resonator (output cavity), and a spent-beam collector. The principal goal of the analysis is to understand the factors that limit the efficiency of the Klystrode and to suggest approaches to achieving improved efficiency. Numerical simulations were performed with the fully electromagnetic, two-and-one-half-dimensional, self-consistent particle-in-cell code, MAGIC. A resonator saturation theory was developed to predict Klystrode performance from startup to saturation. Based on this theory, a one-dimensional optimizing code, KLYDE, was developed to address the design tradeoffs. These tools have been employed to investigate the Klystrode performance over a wide range of parameters with good agreement between MAGIC, KLYDE, theory, and experiment. The analyses suggest that shortening the bunch length is the most effective way to achieve higher efficiencies.

  16. Imaging melanin cancer growth in-vivo using raster-scan optoacoustic mesoscopy (RSOM) at 50 MHz and 100 MHz

    NASA Astrophysics Data System (ADS)

    Omar, Murad; Schwarz, Mathias; Soliman, Dominik; Symvoulidis, Panagiotis; Ntziachristos, Vasilis

    2016-03-01

    We used raster-scan optoacoustic mesoscopy (RSOM) at 50 MHz, and at 100 MHz, to monitor tumor growth, and tumor angiogenesis, which is a central hallmark of cancer, in-vivo. In this study we compared the performance, and the effect of the 50 MHz, and the 100 MHz frequencies on the quality of the final image. The system is based on a reflection-mode implementation of RSOM. The detectors used are custom made, ultrawideband, and spherically focused. The use of such detectors enables light coupling from the same side as the detector, thus reflection-mode. Light is in turn coupled using a fiber bundle, and the detector is raster scanned in the xy-plane. Subsequently, to retrieve small features, the raw data are reconstructed using a multi-bandwidth, beamforming reconstruction algorithm. Comparison of the system performance at the different frequencies shows as expected a higher resolution in case of the 100 MHz detector compared to the 50 MHz. On the other hand the 50 MHz has a better SNR, can detect features from deeper layers, and has higher angular acceptance. Based on these characteristics the 50 MHz detector was mostly used. After comparing the performance we monitored the growth of B16F10 cells, melanin tumor, over the course of 9 days. We see correspondence between the optoacoustic measurements and the cryoslice validations. Additionally, in areas close to the tumor we see sprouting of new vessels, starting at day 4-5, which corresponds to tumor angiogenesis.

  17. 47 CFR 27.17 - Discontinuance of service in the 2000-2020 MHz and 2180-2200 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Discontinuance of service in the 2000-2020 MHz and 2180-2200 MHz bands. 27.17 Section 27.17 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Applications and...

  18. TEM Cell Testing of Cable Noise Reduction Techniques From 2 MHz to 200 MHz - Part 1

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur T.; Evans, William C.; Reed, Joshua L.; Shimp, Samuel K.; Fitzpatrick, Fred D.

    2008-01-01

    This paper presents empirical results of cable noise reduction techniques as demonstrated in a TEM cell operating with radiated fields from 2 - 200 MHz. It is the first part of a two-paper series. This first paper discusses cable types and shield connections. In the second paper, the effects of load and source resistances and chassis connections are examined. For each topic, well established theories are compared to data from a real-world physical system. Finally, recommendations for minimizing cable susceptibility (and thus cable emissions) are presented. There are numerous papers and textbooks that present theoretical analyses of cable noise reduction techniques. However, empirical data is often targeted to low frequencies (e.g. <50 KHz) or high frequencies (>100 MHz). Additionally, a comprehensive study showing the relative effects of various noise reduction techniques is needed. These include the use of dedicated return wires, twisted wiring, cable shielding, shield connections, changing load or source impedances, and implementing load- or source-to-chassis isolation. We have created an experimental setup that emulates a real-world electrical system, while still allowing us to independently vary a host of parameters. The goal of the experiment was to determine the relative effectiveness of various noise reduction techniques when the cable is in the presence of radiated emissions from 2 MHz to 200 MHz. The electronic system (Fig. 1) consisted of two Hammond shielded electrical enclosures, one containing the source resistance, and the other containing the load resistance. The boxes were mounted on a large aluminium plate acting as the chassis. Cables connecting the two boxes measured 81 cm in length and were attached to the boxes using standard D38999 military-style connectors. The test setup is shown in Fig. 2. Electromagnetic fields were created using an HP8657B signal generator, MiniCircuits ZHL-42W-SMA amplifier, and an EMCO 5103 TEM cell. Measurements were

  19. Design concepts and performance of NASA X-band (7162 MHz/8415 MHz) transponder for deep-space spacecraft applications

    NASA Technical Reports Server (NTRS)

    Mysoor, N. R.; Perret, J. D.; Kermode, A. W.

    1991-01-01

    The design concepts and measured performance characteristics are summarized of an X band (7162 MHz/8415 MHz) breadboard deep space transponder (DSP) for future spacecraft applications, with the first use scheduled for the Comet Rendezvous Asteroid Flyby (CRAF) and Cassini missions in 1995 and 1996, respectively. The DST consists of a double conversion, superheterodyne, automatic phase tracking receiver, and an X band (8415 MHz) exciter to drive redundant downlink power amplifiers. The receiver acquires and coherently phase tracks the modulated or unmodulated X band (7162 MHz) uplink carrier signal. The exciter phase modulates the X band (8415 MHz) downlink signal with composite telemetry and ranging signals. The receiver measured tracking threshold, automatic gain control, static phase error, and phase jitter characteristics of the breadboard DST are in good agreement with the expected performance. The measured results show a receiver tracking threshold of -158 dBm and a dynamic signal range of 88 dB.

  20. Cell death induced by GSM 900-MHz and DCS 1800-MHz mobile telephony radiation.

    PubMed

    Panagopoulos, Dimitris J; Chavdoula, Evangelia D; Nezis, Ioannis P; Margaritis, Lukas H

    2007-01-10

    In the present study, the TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay--a well known technique widely used for detecting fragmented DNA in various types of cells--was used to detect cell death (DNA fragmentation) in a biological model, the early and mid stages of oogenesis of the insect Drosophila melanogaster. The flies were exposed in vivo to either GSM 900-MHz (Global System for Mobile telecommunications) or DCS 1800-MHz (Digital Cellular System) radiation from a common digital mobile phone, for few minutes per day during the first 6 days of their adult life. The exposure conditions were similar to those to which a mobile phone user is exposed, and were determined according to previous studies of ours [D.J. Panagopoulos, A. Karabarbounis, L.H. Margaritis, Effect of GSM 900-MHz mobile phone radiation on the reproductive capacity of D. melanogaster, Electromagn. Biol. Med. 23 (1) (2004) 29-43; D.J. Panagopoulos, N. Messini, A. Karabarbounis, A.L. Philippetis, L.H. Margaritis, Radio frequency electromagnetic radiation within "safety levels" alters the physiological function of insects, in: P. Kostarakis, P. Stavroulakis (Eds.), Proceedings of the Millennium International Workshop on Biological Effects of Electromagnetic Fields, Heraklion, Crete, Greece, October 17-20, 2000, pp. 169-175, ISBN: 960-86733-0-5; D.J. Panagopoulos, L.H. Margaritis, Effects of electromagnetic fields on the reproductive capacity of D. melanogaster, in: P. Stavroulakis (Ed.), Biological Effects of Electromagnetic Fields, Springer, 2003, pp. 545-578], which had shown a large decrease in the oviposition of the same insect caused by GSM radiation. Our present results suggest that the decrease in oviposition previously reported, is due to degeneration of large numbers of egg chambers after DNA fragmentation of their constituent cells, induced by both types of mobile telephony radiation. Induced cell death is recorded for the first time, in all types of cells

  1. A 35 MHz PCMUT phased array for NDE ultrasound

    NASA Astrophysics Data System (ADS)

    Snook, Kevin; Jiang, Xiaoning; Hu, Changhong; Geng, Xuecang; Liu, Ruibin; Welter, John; Shung, Kirk; Hackenberger, Wesley S.

    2009-03-01

    In this paper, the development of a 35 MHz 64-channel Piezoelectric Composite based Micromachined Ultrasound Transducer (PCMUT) phased array for NDE ultrasound application is presented. A 35 MHz PMN-PT single crystal 1-3 composite based PC-MUT phased array was designed with extensive acoustic field and 1D modeling. The initial modeling results demonstrated that the focused detection resolution (10% of -3 dB beam width) could be as small as 30 μm in the azimuth direction. The maximum imaging depth for ceramic samples is around 20 mm. The PC-MUT array being developed will extend the state-of-art NDE phased array technology from approximately 20 MHz to 35 MHz, which will greatly enhance the imaging resolution for a broad range of NDE ultrasound applications.

  2. 330 MHz VLA Observations of 20 Galactic Supernova Remnants

    DTIC Science & Technology

    1992-03-01

    We present 330 MHz images and integrated flux densities for 20 previously identified 1st quadrant Galactic Supernova Remnants ( SNRs ). The...plerionic emission for SNRs whose intrinsic morphological type is not well established.

  3. A 45-MHz continuum survey of the northern hemisphere

    NASA Astrophysics Data System (ADS)

    Maeda, K.; Alvarez, H.; Aparici, J.; May, J.; Reich, P.

    We present a 45-MHz continuum survey in the declination range of +5 to +65 degrees in sets of maps in galactic and equatorial coordinates (epoch 1950). The observations were made at 46.5 MHz with a circular filled array of the Japanese Middle and Upper Atmosphere Radar (MU Radar) located at Shigaraki, Japan. The radar array consists of 475 crossed 3-element Yagis arranged within a circle of 103 m diameter, with a the half-power beam width of 3.6 degrees. In order to calibrate the data from the MU radar we used the Chilean 45-MHz survey which was made with an array of size comparable with that of the MU radar. The data processing was performed at the Maipu Radio Observatory, University of Chile, and this process brought the data to 45 MHz. The final maps were obtained at the Max-Plank-Institut fur Radioastronomie, Germany, using of the NOD2 program package.

  4. Real-Time, Polyphase-FFT, 640-MHz Spectrum Analyzer

    NASA Technical Reports Server (NTRS)

    Zimmerman, George A.; Garyantes, Michael F.; Grimm, Michael J.; Charny, Bentsian; Brown, Randy D.; Wilck, Helmut C.

    1994-01-01

    Real-time polyphase-fast-Fourier-transform, polyphase-FFT, spectrum analyzer designed to aid in detection of multigigahertz radio signals in two 320-MHz-wide polarization channels. Spectrum analyzer divides total spectrum of 640 MHz into 33,554,432 frequency channels of about 20 Hz each. Size and cost of polyphase-coefficient memory substantially reduced and much of processing loss of windowed FFTs eliminated.

  5. The 136 MHZ/400 MHz earth station antenna-noise temperature prediction program for RAE-B

    NASA Technical Reports Server (NTRS)

    Taylor, R. E.; Fee, J. J.; Chin, M.

    1972-01-01

    A simulation study was undertaken to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low noise periods. Antenna noise temperatures will be predicted for selected earth-based ground stations which will support RAE-B. Telemetry data acquisition will be at 400 MHz; tracking support at 136 MHz will be provided by the Goddard Range and Range Rate (RARR) stations. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973.

  6. The 136 MHz/400 MHz earth station antenna-noise temperature prediction program documentation for RAE-B

    NASA Technical Reports Server (NTRS)

    Chin, M.

    1972-01-01

    A simulation study to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods is described. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio (SNR) of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low-noise periods. Antenna-noise temperatures at 136 MHz and 400 MHz will be predicted for selected earth-based ground stations which will support RAE-B. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973. The RAE-B mission will be expecially susceptible to SNR degradation during the two eclipses of the Sun occurring in this period.

  7. 154 MHz Detection of Faint, Polarized Flares from UV Ceti

    NASA Astrophysics Data System (ADS)

    Lynch, C. R.; Lenc, E.; Kaplan, D. L.; Murphy, Tara; Anderson, G. E.

    2017-02-01

    We have detected four flares from UV Ceti at 154 MHz using the Murchison Widefield Array. The flares have flux densities between 10 and 65 mJy—a factor of 100 fainter than most flares in the literature at these frequencies—and are only detected in polarization. The circular polarized fractions are limited to > 27% at 3σ confidence and two of the flares exhibit polarity reversal. We suggest that these flares occur periodically on a timescale consistent with the rotational period of UV Ceti. During the brightest observed flare, we also detect significant linear polarization with a polarization fraction > 18%. Averaging the data in 6 minute, 10 MHz frequency bins we find that the flux density of these flares does not vary over the 30 MHz bandwidth of the Murchison Widefield Array; however, we cannot rule out finer time-frequency structure. Using the measured flux densities for the flares, we estimate brightness temperatures between ({10}13{--}{10}14) K, indicative of a coherent emission mechanism. The brightness temperature and polarization characteristics point to the electron cyclotron maser mechanism. We also calculate the flare rates given our four observed flares and compare them to flare rates for the set of M dwarf stars with known 100–200 MHz flares. Our measurement is the first for flares with intensities < 100 mJy at 100–200 MHz.

  8. A 100 MHz antenna based on magnetoelectric composite materials

    NASA Astrophysics Data System (ADS)

    Tatarenko, A. S.; Petrov, R.; Srinivasan, G.; Bichurin, M. I.

    2008-03-01

    Results on miniaturization of a 100 MHz-antenna based on magnetoelectric composites are presented. A composite with large and equal permittivity and permeability is sought for the task. In such composites both miniaturization and impedance match to free-space are possible. A sample of nickel zinc ferrite and bismuth strontium titanate prepared by the conventional ceramic processing is used. The dipole antenna operating at 100 MHz consists of a composite substrate 220 mm in diameter and 8.5 mm in width and a Cu-strip 6.5 mm in diameter. Antenna characteristics are measured with a vector network analyzer. Scattering parameter data indicates resonance at 98 MHz and an antenna miniaturization factor of 7-10, in agreement with theoretical estimates.

  9. 120 MW, 800 MHz Magnicon for a Future Muon Collider

    SciTech Connect

    Jay L. Hirshfield

    2005-12-15

    Development of a pulsed magnicon at 800 MHz was carried out for the muon collider application, based on experience with similar amplifiers in the frequency range between 915 MHz and 34.3 GHz. Numerical simulations using proven computer codes were employed for the conceptual design, while established design technologies were incorporated into the engineering design. A cohesive design for the 800 MHz magnicon amplifier was carried out, including design of a 200 MW diode electron gun, design of the magnet system, optimization of beam dynamics including space charge effects in the transient and steady-state regimes, design of the drive, gain, and output cavities including an rf choke in the beam exit aperture, analysis of parasitic oscillations and design means to eliminate them, and design of the beam collector capable of 20 kW average power operation.

  10. 318-MHz variability of complete samples of extragalactic radio sources

    NASA Technical Reports Server (NTRS)

    Dennison, B.; Broderick, J. J.; Ledden, J. E.; Odell, S. L.; Condon, J. J.

    1981-01-01

    It is found by a low-frequency variability survey, involving two- and three-epoch, 318-MHz observations of extragalactic sources in samples complete to 3 Jy at 1400 MHz and 1 Jy at 5000 MHz, that steep-spectrum sources do not seem to vary while all flat-spectrum sources exhibit low-frequency variability greater than 8% over about 5 yr. It is also found that the flat-spectrum sources with inverted spectra show the largest fractional variations, and that there is a correlation between the incidence of low-frequency variability and the determination that a source is an optically violent variable. These statistical properties are consistent with models which invoke radio and optical emission relativistic beaming.

  11. Millisecond solar radio spikes observed at 1420 MHz

    NASA Astrophysics Data System (ADS)

    Dabrowski, B. P.; Kus, A. J.

    We present results from observations of narrowband solar millisecond radio spikes at 1420 MHz. Observing data were collected between February 2000 and December 2001 with the 15-m radio telescope at the Centre for Astronomy Nicolaus Copernicus University in Torun, Poland, equipped with a radio spectrograph that covered the 1352-1490 MHz frequency band. The radio spectrograph has 3 MHz frequency resolution and 80 microsecond time resolution. We analyzed the individual radio spike duration, bandwidth and rate of frequency drift. A part of the observed spikes showed well-outlined subtle structures. On dynamic radio spectrograms of the investigated events we notice complex structures formed by numerous individual spikes known as chains of spikes and distinctly different structure of columns. Positions of active regions connected with radio spikes emission were investigated. It turns out that most of them are located near the center of the solar disk, suggesting strong beaming of the spikes emission.

  12. A 449 MHz modular wind profiler radar system

    NASA Astrophysics Data System (ADS)

    Lindseth, Bradley James

    This thesis presents the design of a 449 MHz radar for wind profiling, with a focus on modularity, antenna sidelobe reduction, and solid-state transmitter design. It is one of the first wind profiler radars to use low-cost LDMOS power amplifiers combined with spaced antennas. The system is portable and designed for 2-3 month deployments. The transmitter power amplifier consists of multiple 1-kW peak power modules which feed 54 antenna elements arranged in a hexagonal array, scalable directly to 126 elements. The power amplifier is operated in pulsed mode with a 10% duty cycle at 63% drain efficiency. The antenna array is designed to have low sidelobes, confirmed by measurements. The radar was operated in Boulder, Colorado and Salt Lake City, Utah. Atmospheric wind vertical and horizontal components at altitudes between 200m and 4km were calculated from the collected atmospheric return signals. Sidelobe reduction of the antenna array pattern is explored to reduce the effects of ground or sea clutter. Simulations are performed for various shapes of compact clutter fences for the 915-MHz beam-steering Doppler radar and the 449-MHz spaced antenna interferometric radar. It is shown that minimal low-cost hardware modifications to existing compact ground planes of 915-MHz beam-steering radar allow for reduction of sidelobes of up to 5dB. The results obtained on a single beam-steering array are extended to the 449 MHz triple hexagonal array spaced antenna interferometric radar. Cross-correlation, transmit beamwidth, and sidelobe levels are evaluated for various clutter fence configurations and array spacings. The resulting sidelobes are as much as 10 dB below those without a clutter fence and can be incorporated into existing and future 915 and 449 MHz wind profiler systems with minimal hardware modifications.

  13. MHz gravitational waves from short-term anisotropic inflation

    NASA Astrophysics Data System (ADS)

    Ito, Asuka; Soda, Jiro

    2016-04-01

    We reveal the universality of short-term anisotropic inflation. As a demonstration, we study inflation with an exponential type gauge kinetic function which is ubiquitous in models obtained by dimensional reduction from higher dimensional fundamental theory. It turns out that an anisotropic inflation universally takes place in the later stage of conventional inflation. Remarkably, we find that primordial gravitational waves with a peak amplitude around 10-26~ 10-27 are copiously produced in high-frequency bands 10 MHz~100 MHz. If we could detect such gravitational waves in future, we would be able to probe higher dimensional fundamental theory.

  14. 47 CFR 90.355 - LMS operations below 512 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false LMS operations below 512 MHz. 90.355 Section 90.355 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Intelligent Transportation Systems Radio Service § 90.355...

  15. COSPAS/SARSAT 406-MHz emergency beacon digital controller

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    1988-01-01

    The digital control portion of a low-cost 406-MHz COSPAS/SARSAT emergency beacon has been designed and breadboarded at the NASA Lewis Research Center. This report discusses the requirements and design tradeoffs of the digital controller and describes the hardware and software design, which is available only to United States citizens and companies.

  16. Modeling of a 1700-MHz cluster cavity of planar triodes

    SciTech Connect

    Rees, D.E.; Friedrichs, C. Jr.

    1991-01-01

    In this paper we present the modeling and design of a 1700-MHz cluster-cavity vacuum tube amplifier. We used a three-dimensional, finite-difference code (MAFIA) to characterize the modes that the resonant structure of the amplifier will support. We describe the characteristics of the tube, including performance predictions. 1 ref., 5 figs., 1 tab.

  17. Radar - 449MHz - North Bend, OR (OTH) - Raw Data

    SciTech Connect

    Coleman, Tim

    2016-10-25

    **Winds.** A radar wind profiler measures the Doppler shift of electromagnetic energy scattered back from atmospheric turbulence and hydrometeors along 3-5 vertical and off-vertical point beam directions. Back-scattered signal strength and radial-component velocities are remotely sensed along all beam directions and are combined to derive the horizontal wind field over the radar. These data typically are sampled and averaged hourly and usually have 6-m and/or 100-m vertical resolutions up to 4 km for the 915 MHz and 8 km for the 449 MHz systems. **Temperature.** To measure atmospheric temperature, a radio acoustic sound system (RASS) is used in conjunction with the wind profile. These data typically are sampled and averaged for five minutes each hour and have a 60-m vertical resolution up to 1.5 km for the 915 MHz and 60-m up to 3.5k m for the 449 MHz. **Spectra.** The daily raw spectra data are available. The files are labeled "header" and "data." These data files are generated by LapXM, binary encoded, and are specific to this application. These datasets contain the raw data from the radar, such as signal-to-noise, signal power, radial velocity, and spectra widths.

  18. Radar - 449MHz - Astoria, OR (AST) - Raw Data

    SciTech Connect

    Coleman, Tim

    2016-10-25

    **Winds.** A radar wind profiler measures the Doppler shift of electromagnetic energy scattered back from atmospheric turbulence and hydrometeors along 3-5 vertical and off-vertical point beam directions. Back-scattered signal strength and radial-component velocities are remotely sensed along all beam directions and are combined to derive the horizontal wind field over the radar. These data typically are sampled and averaged hourly and usually have 6-m and/or 100-m vertical resolutions up to 4 km for the 915 MHz and 8 km for the 449 MHz systems. **Temperature.** To measure atmospheric temperature, a radio acoustic sound system (RASS) is used in conjunction with the wind profile. These data typically are sampled and averaged for five minutes each hour and have a 60-m vertical resolution up to 1.5 km for the 915 MHz and 60-m up to 3.5k m for the 449 MHz. **Spectra.** The daily raw spectra data are available. The files are labeled "header" and "data." These data files are generated by LapXM, binary encoded, and are specific to this application. These datasets contain the raw data from the radar, such as signal-to-noise, signal power, radial velocity, and spectra widths.

  19. Radar - 449MHz - Forks, WA (FKS) - Raw Data

    SciTech Connect

    Coleman, Tim

    2016-10-25

    **Winds.** A radar wind profiler measures the Doppler shift of electromagnetic energy scattered back from atmospheric turbulence and hydrometeors along 3-5 vertical and off-vertical point beam directions. Back-scattered signal strength and radial-component velocities are remotely sensed along all beam directions and are combined to derive the horizontal wind field over the radar. These data typically are sampled and averaged hourly and usually have 6-m and/or 100-m vertical resolutions up to 4 km for the 915 MHz and 8 km for the 449 MHz systems. **Temperature.** To measure atmospheric temperature, a radio acoustic sound system (RASS) is used in conjunction with the wind profile. These data typically are sampled and averaged for five minutes each hour and have a 60-m vertical resolution up to 1.5 km for the 915 MHz and 60-m up to 3.5k m for the 449 MHz. **Spectra.** The daily raw spectra data are available. The files are labeled "header" and "data." These data files are generated by LapXM, binary encoded, and are specific to this application. These datasets contain the raw data from the radar, such as signal-to-noise, signal power, radial velocity, and spectra widths.

  20. 47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of any of the other radio astronomy observatories noted in footnote US 311 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio...

  1. 47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of any of the other radio astronomy observatories noted in footnote US385 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio...

  2. 47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of any of the other radio astronomy observatories noted in footnote US385 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio...

  3. 47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of any of the other radio astronomy observatories noted in footnote US 311 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio...

  4. 47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... of any of the other radio astronomy observatories noted in footnote US 311 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio...

  5. Wireless communication link for capsule endoscope at 600 MHz.

    PubMed

    Khaleghi, A; Balasingham, I

    2015-01-01

    Simulation of a wireless communication link for a capsule endoscopy is presented for monitoring of small intestine in humans. The realized communication link includes the transmitting capsule antenna, the outside body receiving antenna and the model of the human body. The capsule antenna is designed for operating at the frequency band of 600 MHz with an impedance bandwidth of 10 MHz and omnidirectional radiation pattern. The quality of the communication link is improved by using directive antenna outside body inside matching layer for electromagnetic wave tuning to the body. The outside body antenna has circular polarization that guaranteeing the communication link for different orientations of the capsule inside intestine. It is shown that the path loss for the capsule in 60 mm from the abdomen surface varies between 37-47 dB in relation to the antenna orientation. This link can establish high data rate wireless communications for capsule endoscopy.

  6. JTIDS electromagnetic compatibility in the 960-1215 MHz band

    NASA Astrophysics Data System (ADS)

    Lokuta, Robert S.

    1992-01-01

    The Joint Tactical Information Distribution System (JTIDS) operates in the 960-1215 MHz frequency band. This band is allocated world-wide on a primary basis for aeronautical radio navigation. JTIDS was designed to be electromagnetically compatible with the Air Traffic Control systems that operate in this band. Over the past 15 years, extensive bench tests, flight tests, and analyses were conducted to assess the electromagnetic compatibility (EMC) of JTIDS in the 960-1215 MHz band. This report summarizes the results and conclusions of these efforts, presents some supporting data and provides specific guidance for the operation of JTIDS within the National Air Space. Guidance and recommendations are also provided to assist in the definition and scope of a JTIDS EMC test and analysis effort.

  7. 800MHz Crab Cavity Conceptual Design For the LHC Upgrade

    SciTech Connect

    Xiao, Liling; Li, Zenghai; Ng, Cho-Kuen; Seryi, Andrei; /SLAC

    2009-05-26

    In this paper, we present an 800 MHz crab cavity conceptual design for the LHC upgrade. The cell shape is optimized for lower maximum peak surface fields as well as higher transverse R/Q. A compact coax-to-coax coupler scheme is proposed to damp the LOM/SOM modes. A two-stub antenna with a notch filter is used as the HOM coupler to damp the HOM modes in the horizontal plane and rejects the operating mode at 800MHz. Multipacting (MP) simulations show that there are strong MP particles at the disks. Adding grooves along the short axis without changing the operating mode's RF characteristics can suppress the MP activities. Possible input coupler configurations are discussed.

  8. First Images from the 74 MHz VLA - Pie Town Link

    NASA Astrophysics Data System (ADS)

    Lane, W. M.; Cohen, A. S.; Kassim, N. E.; Lazio, T. J. W.

    2005-12-01

    A 74 MHz (4m wavelength) receiver has now been added to the VLBA antenna at Pie Town, bringing the full resolving power of the VLA + Pie Town Link to this low frequency. With baselines up to 73 km, corresponding to resolutions of ˜10 arcsec, and sensitivities ˜20 mJy bm-1, the first observations shown here have achieved by far the highest resolution and sensitivity of any images at this frequency to date.

  9. Deep Westerbork observations of Abell 2256 at 350 MHz

    NASA Astrophysics Data System (ADS)

    Brentjens, M. A.

    2008-10-01

    Deep polarimetric Westerbork observations of the galaxy cluster Abell 2256 are presented, covering a frequency range of 325-377 MHz. The central halo source has a diameter of the order of 1.2 Mpc (18´), which is somewhat larger than at 1.4 GHz. With α = -1.61±0.04, the halo spectrum between 1.4 GHz and 22.25 MHz is less steep than previously thought. The centre of the ultra steep spectrum source in the eastern part of the cluster exhibits a spectral break near 400 MHz. It is estimated to be at least 51 million years old, but possibly older than 125 million years. A final measurement requires observations in the 10-150 MHz range. It remains uncertain whether the source is a radio tail of Fabricant galaxy 122, situated in the northeastern tip of the source. Faraday rotation measure synthesis revealed no polarized flux at all in the cluster. The polarization fraction of the brightest parts of the relic area is less than 1%. The RM-synthesis nevertheless revealed 9 polarized sources in the field enabling an accurate measurement of the Galactic Faraday rotation (-33±2 rad m-2 in front of the relic). Based on its depolarization on longer wavelengths, the line-of-sight magnetic field in relic filament G is estimated to be between 0.02 and 2 μG. A value of 0.2 μG appears most reasonable given the currently available data.

  10. Detection of 610-MHz radio emission from hot magnetic stars

    NASA Astrophysics Data System (ADS)

    Chandra, P.; Wade, G. A.; Sundqvist, J. O.; Oberoi, D.; Grunhut, J. H.; ud-Doula, A.; Petit, V.; Cohen, D. H.; Oksala, M. E.; David-Uraz, A.

    2015-09-01

    We have carried out a study of radio emission from a small sample of magnetic O- and B-type stars using the Giant Metrewave Radio Telescope, with the goal of investigating their magnetospheres at low frequencies. These are the lowest frequency radio measurements ever obtained of hot magnetic stars. The observations were taken at random rotational phases in the 1390 and the 610 MHz bands. Out of the eight stars, we detect five B-type stars in both the 1390 and the 610 MHz bands. The three O-type stars were observed only in the 1390 MHz band, and no detections were obtained. We explain this result as a consequence of free-free absorption by the free-flowing stellar wind exterior to the confined magnetosphere. We also study the variability of individual stars. One star - HD 133880 - exhibits remarkably strong and rapid variability of its low-frequency flux density. We discuss the possibility of this emission being coherent emission as reported for CU Vir by Trigilio et al.

  11. MHz gravitational wave constraints with decameter Michelson interferometers

    NASA Astrophysics Data System (ADS)

    Chou, Aaron S.; Gustafson, Richard; Hogan, Craig; Kamai, Brittany; Kwon, Ohkyung; Lanza, Robert; Larson, Shane L.; McCuller, Lee; Meyer, Stephan S.; Richardson, Jonathan; Stoughton, Chris; Tomlin, Raymond; Weiss, Rainer; Holometer Collaboration

    2017-03-01

    A new detector, the Fermilab Holometer, consists of separate yet identical 39-meter Michelson interferometers. Strain sensitivity achieved is better than 10-21/√{Hz } between 1 to 13 MHz from a 130-h data set. This measurement exceeds the sensitivity and frequency range made from previous high frequency gravitational wave experiments by many orders of magnitude. Constraints are placed on a stochastic background at 382 Hz resolution. The 3 σ upper limit on ΩGW, the gravitational wave energy density normalized to the closure density, ranges from 5.6 ×1 012 at 1 MHz to 8.4 ×1 015 at 13 MHz. Another result from the same data set is a search for nearby primordial black hole binaries (PBHB). There are no detectable monochromatic PBHBs in the mass range 0.83 - 3.5 ×1 021 g between the Earth and the Moon. Projections for a chirp search with the same data set increase the mass range to 0.59 -2.5 ×1 025 g and distances out to Jupiter. This result presents a new method for placing limits on a poorly constrained mass range of primordial black holes. Additionally, solar system searches for PBHBs place limits on their contribution to the total dark matter fraction.

  12. Search for Radio Emissions From Extrasolar Planets at 150 MHz

    NASA Astrophysics Data System (ADS)

    Winterhalter, D.; Majid, W. A.; Kuiper, T. B.; Chandra, I.; Lazio, J.; Gupta, Y.; Naudet, C. J.; Zarka, P.; Bryden, G.; Gonzalez, W.

    2005-12-01

    Using the new 150 MHz receivers of the Giant Metrewave Radiotelescope (GMRT) in India, we have searched for radio emissions from a sub-set of known "hot Jupiters": UpsAnd, Tauboo, 70 Vir, HD162020, and HD179949. We have selected these targets based on the expected flux density and the level of background noise. Calibrations with GMRT at 150 MHz have confirmed the noise floor to be a few mJy over a 5 MHz bandwidth. The noise floor is well below the expected flux levels from the targets. No observation of these targets has been attempted previously at these frequencies with the sensitivity and aperture offered by GMRT. Radio maps of the targets were produced using the AIPS CLEANing and image making software, and will be presented. Dynamic spectra from the target regions will also be presented. In addition to the targets above, we have just (August 2005) completed new and deeper (longer integration times) radio observations of UpsAnd, HD179949 (evidence of star-planet magenic connection), HD188753Ab (newly discovered in tripple star system), HD209458b (transiting planet), and Gliese876 (red dwarf system containg "rocky" planet). Time permitting for analyses, we will present very preliminary, first-look, results.

  13. Search for Radio Emissions from Extrasolar Planets at 150 MHz

    NASA Astrophysics Data System (ADS)

    Winterhalter, D.; Majid, WA; Kuiper, TBH; Naudet, CJ; Bryden, G.; Chandra, I.; Gupta, Y.; Lazio, J.; Zarka, P.; Gonzalez, W.

    2005-12-01

    Using the new 150 MHz receivers of the Giant Metrewave Radiotelescope (GMRT) in India, we have searched for radio emissions from a sub-set of known "hot Jupiters": UpsAnd, Tauboo, 70 Vir, HD162020, and HD179949. We have selected these targets based on the expected flux density and the level of background noise. Calibrations with GMRT at 150 MHz have confirmed the noise floor to be a few mJy over a 5 MHz bandwidth. The noise floor is well below the expected flux levels from the targets. No observation of these targets has been attempted previously at these frequencies with the sensitivity and aperture offered by GMRT. Radio maps of the targets were produced using the AIPS CLEANing and image making software, and will be presented. Dynamic spectra from the target regions will also be presented. In addition to the targets above, we have just (August 2005) completed new and deeper (longer integration times) radio observations of UpsAnd, HD179949 (evidence of star-planet magenic connection), HD188753Ab (newly discovered in tripple star system), HD209458b (transiting planet), and Gliese876 (red dwarf system containg "rocky" planet). Time permitting for analyses, we will present very preliminary, first-look, results.

  14. Arecibo 1418 MHz Polarimetry and Morphological Classification of 95 Pulsars

    NASA Astrophysics Data System (ADS)

    Weitz, K. A.; Weisberg, J. M.; Dawson, B. R.; Despotes, J. T.; Morgan, J. J.; Zink, E. C.; Cordes, J. M.; Lundgren, S. C.; Backer, D. C.

    1995-12-01

    The classification of pulsars allows for the organization of groups of objects which share common features. These classes can then be studied for further correlations, providing insight into a variety of emission and evolutionary questions. Most classification systems are based on the analysis of polarized profiles over a wide frequency range. We gathered polarization data on over one hundred pulsars at 1418 MHz in fifteen observing sessions from 1989 to 1993, using the 305 meter Arecibo telescope. A 20 MHz digital multichannel correlation polarimeter was employed on-line. The multifrequency channels were then dedispersed before summing. All data for each individual pulsar were then calibrated and combined into one full Stokes parameter profile. This process led to polarized average pulse profiles for ninety-five of the pulsars. We used the Rankin (1983) system as the basis for our morphological classifications of the 95 pulsars. In Rankin's model, the frequency evolution of the polarized characteristics of each pulse component is assessed in order to distinguish core from hollow cone emission beams. We studied our 1418 MHz data and all other published polarimetry on each pulsar in order to determine the morphological classifications. We present the polarized profiles and discuss the morphological classifications for these 95 pulsars.

  15. DC SQUID RF magnetometer with 200 MHz bandwidth

    NASA Astrophysics Data System (ADS)

    Talanov, Vladimir; Lettsome, Nesco; Orozco, Antonio; Cawthorne, Alfred; Borzenets, Valery

    2012-02-01

    Because of periodic flux-to-voltage transfer function, Superconducting QUantum Interference Device (SQUID) magnetometers operate in a closed-loop regime [1], which linearizes the response, and increases the dynamic range and sensitivity. However, a transmission line delay between the SQUID and electronics fundamentally limits the closed-loop bandwidth at 20 MHz [1], although the intrinsic bandwidth of SQUIDs is in gigahertz range. We designed a DC SQUID based RF magnetometer capable of wideband sensing coherent magnetic fields up to 200 MHz. To overcome the closed-loop bandwidth limitation, we utilized a low-frequency flux-modulated closed-loop to simultaneously lock the quasi-static magnetic flux and provide AC bias for the RF flux. The SQUID RF voltage is processed by RF electronics based on a double lock-in technique. This yields a signal proportional to the amplitude and phase of the RF magnetic flux, with more than four decades of a linear response. For YBaCuO SQUID on bi-crystal SrTiO substrate at 77 K we achieved a flux noise density of 4 μφ0/Hz at 190 MHz, which is similar to that measured at kHz frequencies with conventional flux-locked loop. [1] D. Drung, et al., Supercond. Sci. Technol. 19, S235 (2006).

  16. A scanning SQUID microscope with 200 MHz bandwidth

    NASA Astrophysics Data System (ADS)

    Talanov, Vladimir V.; Lettsome, Nesco M., Jr.; Borzenets, Valery; Gagliolo, Nicolas; Cawthorne, Alfred B.; Orozco, Antonio

    2014-04-01

    We developed a scanning DC SQUID microscope with novel readout electronics capable of wideband sensing of RF magnetic fields from 50 to 200 MHz and simultaneously providing closed-loop response at kHz frequencies. To overcome the 20 MHz bandwidth limitation of traditional closed-loop SQUIDs, a flux-modulated closed-loop simultaneously locks the SQUID quasi-static flux and flux-biases the SQUID for amplification of the RF flux up to Φ0/4 in amplitude. Demodulating the SQUID voltage with a double lock-in technique yields a signal representative of both the amplitude and phase of the RF flux. This provides 80 dB of a linear dynamic range with a flux noise density of 4 μΦ0 Hz-1/2 at 200 MHz for a Y Ba2Cu3O7 bi-crystal SQUID at 77 K. We describe the electronics’ performance and present images for RF magnetic field of the travelling wave in a coplanar waveguide, the standing wave in an open-circuited microstrip, and a surface mounted device antenna.

  17. Fast Radio Transient searches with UTMOST at 843 MHz

    NASA Astrophysics Data System (ADS)

    Caleb, M.; Flynn, C.; Bailes, M.; Barr, E. D.; Bateman, T.; Bhandari, S.; Campbell-Wilson, D.; Green, A. J.; Hunstead, R. W.; Jameson, A.; Jankowski, F.; Keane, E. F.; Ravi, V.; van Straten, W.; Krishnan, V. Venkataraman

    2016-05-01

    We report the first radio interferometric search at 843 MHz for fast transients, particularly Fast Radio Bursts (FRBs). The recently recommissioned Swinburne University of Technology's digital backend for the Molonglo Observatory Synthesis Telescope array (the UTMOST) with its large collecting area (18 000 m2) and wide instantaneous field of view (7.80 deg2) is expected to be an efficient tool to detect FRBs. As an interferometer it will be capable of discerning whether the FRBs are truly a celestial population. We show that UTMOST at full design sensitivity can detect an event approximately every few days. We report on two preliminary FRB surveys at about 7 per cent and 14 per cent, respectively, of the array's final sensitivity. Several pulsars have been detected via single pulses and no FRBs were discovered with pulse widths (W), in the range 655.36 μs < W < 41.9 ms and dispersion measures (DMs) in the range 100 < DM < 2000 pc cm-3. This non-detection sets a 2σ upper limit of the sky rate of not more than 1000 events sky-1 d-1 at 843 MHz down to a flux limit of 11 Jy for 1 ms FRBs. We show that this limit is consistent with previous survey limits at 1.4 GHz and 145 MHz and set a lower limit on the mean spectral index of FRBs of α > -3.2.

  18. Velocities of auroral coherent echoes at 12 and 144 MHz

    NASA Astrophysics Data System (ADS)

    Koustov, A. V.; Danskin, D. W.; Uspensky, M. V.; Ogawa, T.; Janhunen, P.; Nishitani, N.; Nozawa, S.; Lester, M.; Milan, S.

    2002-10-01

    Two Doppler coherent radar systems are currently working at Hankasalmi, Finland, the STARE and CUTLASS radars operating at ~144 MHz and ~12 MHz, respectively. The STARE beam 3 is nearly co-located with the CUTLASS beam 5, providing an opportunity for echo velocity comparison along the same direction but at significantly different radar frequencies. In this study we consider an event when STARE radar echoes are detected at the same ranges as CUT-LASS radar echoes. The observations are complemented by EISCAT measurements of the ionospheric electric field and electron density behaviour at one range of 900 km. Two separate situations are studied; for the first one, CUTLASS observed F-region echoes (including the range of the EIS-CAT measurements), while for the second one CUTLASS observed E-region echoes. In both cases STARE E-region measurements were available. We show that F-region CUT-LASS velocities agree well with the convection component along the CUTLASS radar beam, while STARE velocities are typically smaller by a factor of 2 3. For the second case, STARE velocities are found to be either smaller or larger than CUTLASS velocities, depending on the range. Plasma physics of E-and F-region irregularities is discussed in attempt to explain the inferred relationship between various velocities. Special attention is paid to ionospheric refraction that is important for the detection of 12-MHz echoes.

  19. A 2-to-48-MHz Phase-Locked Loop

    NASA Technical Reports Server (NTRS)

    Koudelka, Robert D.

    2004-01-01

    A 2-to-48-MHz phase-locked loop (PLL), developed for the U.S. space program, meets or exceeds all space shuttle clock electrical interface requirements by taking as its reference a 2-to-48-MHz clock signal and outputting a phaselocked clock signal set at the same frequency as the reference clock with transistor- transistor logic (TTL) voltage levels. Because it is more adaptable than other PLLs, the new PLL can be used in industries that employ signaling devices and as a tool in future space missions. A conventional PLL consists of a phase/frequency detector, loop filter, and voltage-controlled oscillator in which each component exists individually and is integrated into a single device. PLL components phase-lock to a single frequency or to a narrow bandwidth of frequencies. It is this design, however, that prohibits them from maintaining phase lock to a dynamically changing reference clock when a large bandwidth is required a deficiency the new PLL overcomes. Since most PLL components require their voltage-controlled oscillators to operate at greater than 2-MHz frequencies, conventional PLLs often cannot achieve the low-frequency phase lock allowed by the new PLL. The 2-to-48-MHz PLL is built on a wire-wrap board with pins wired to three position jumpers; this makes changing configurations easy. It responds to variations in voltage-controlled oscillator (VCO) ranges, duty cycle, signal-to-noise ratio (SNR), amplitude, and jitter, exceeding design specifications. A consensus state machine, implemented in a VCO range detector which assures the PLL continues to operate in the correct range, is the primary control state machine for the 2-to-48-MHz PLL circuit. By using seven overlapping frequency ranges with hysteresis, the PLL output sets the resulting phase-locked clock signal at a frequency that agrees with the reference clock with TTL voltage levels. As a space-shuttle tool, the new PLL circuit takes the noisy, degraded reference clock signals as input and outputs

  20. Effects of gas pressure on 60/13.56 MHz dual-frequency capacitively coupled plasmas

    SciTech Connect

    Yuan, Q. H.; Yin, G. Q.; Xin, Y.; Ning, Z. Y.

    2011-05-15

    The electron energy probability functions (EEPFs) were measured with increasing gas pressure in 60/13.56 MHz dual-frequency capacitively coupled plasma (DF-CCP) using compensated Langmiur electrostatic probe. The transition pressure of heating mode from collisionless to collisional heating in 60/13.56 MHz DF-CCP is found to be significantly lower than that in 13.56 MHz single-frequency CCP. As the pressure increases, the EEPFs change from bi-Maxwellian to Druyvesteyn type which is similar with that in 60 MHz single-frequency CCP. The pressure dependence of electron densities, effective electron temperatures, floating potentials, and plasma potentials in 60/13.56 MHz DF-CCP were measured and were compared with that in 60 MHz single-frequency CCP. The pressure dependence of these plasma parameters in 60/13.56 MHz DF-CCP is similar with that in 60 MHz single-frequency CCP.

  1. 47 CFR 90.816 - Criteria for comparative 900 MHz SMR renewal proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.816 Criteria for comparative 900 MHz SMR renewal proceedings....

  2. 47 CFR 90.816 - Criteria for comparative 900 MHz SMR renewal proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.816 Criteria for comparative 900 MHz SMR renewal proceedings....

  3. 47 CFR 90.816 - Criteria for comparative 900 MHz SMR renewal proceedings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.816 Criteria for comparative 900 MHz SMR renewal proceedings....

  4. 47 CFR 90.816 - Criteria for comparative 900 MHz SMR renewal proceedings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.816 Criteria for comparative 900 MHz SMR renewal proceedings....

  5. 47 CFR 90.816 - Criteria for comparative 900 MHz SMR renewal proceedings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.816 Criteria for comparative 900 MHz SMR renewal proceedings....

  6. 47 CFR 27.1230 - Conversion of the 2500-2690 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service... 2500-2690 MHz band. BRS and EBS licensees in the 2500-2690 MHz band on the pre-transition A-I...

  7. A 27 Channels, 1 MHz Fibre-Optic Measuring System (Een 27-Kannaals, 1 MHz Optisch Meetsysteem)

    DTIC Science & Technology

    1993-03-01

    het meetsysteem liggen. Als kantelpunt van het laagdoorlaat filter is wtceindelijk een frequentie van 3,6 MHz gekozeii; deze waarde blijkt optimaal te...Optical Output Logic "I" Logic Ŕ" optical Port Core Diameter >2 4V ɘ 4V @ 1 6mA siniK 200Pm Overvoltage Protection Peek Wavelength WX +7V maximum 820nmj

  8. Optimized (2nd Pass) Gallium Arsenide (GaAs) Integrated Circuit Radio Frequency (RF) Booster Designs for 425 MHz and Dual Band (425 and 900 MHz)

    DTIC Science & Technology

    2010-11-01

    RF) Booster Designs for 425 MHz and Dual Band (425 and 900 MHz) John Penn Sensors and Electron Devices Directorate, ARL...in many wireless systems. This report documents a set of MMIC designs optimized for the 400 to 450 MHz ultra-high frequency (UHF) band and a dual...improve size and weight of wireless systems. This is an optimized set of designs based on a previous 1st pass design effort. Ten separate MMIC designs

  9. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject...

  10. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject...

  11. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject...

  12. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject...

  13. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject...

  14. 47 CFR 80.148 - Watch on 156.8 MHz (Channel 16).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Watch on 156.8 MHz (Channel 16). 80.148 Section... Watches § 80.148 Watch on 156.8 MHz (Channel 16). Each compulsory vessel, while underway, must maintain a watch for radiotelephone distress calls on 156.800 MHz whenever such station is not being used...

  15. 47 CFR 80.148 - Watch on 156.8 MHz (Channel 16).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Watch on 156.8 MHz (Channel 16). 80.148 Section... Watches § 80.148 Watch on 156.8 MHz (Channel 16). Each compulsory vessel, while underway, must maintain a watch for radiotelephone distress calls on 156.800 MHz whenever such station is not being used...

  16. 47 CFR 80.148 - Watch on 156.8 MHz (Channel 16).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Watch on 156.8 MHz (Channel 16). 80.148 Section... Watches § 80.148 Watch on 156.8 MHz (Channel 16). Each compulsory vessel, while underway, must maintain a watch for radiotelephone distress calls on 156.800 MHz whenever such station is not being used...

  17. 47 CFR 80.148 - Watch on 156.8 MHz (Channel 16).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Watch on 156.8 MHz (Channel 16). 80.148 Section... Watches § 80.148 Watch on 156.8 MHz (Channel 16). Each compulsory vessel, while underway, must maintain a watch for radiotelephone distress calls on 156.800 MHz whenever such station is not being used...

  18. 47 CFR 80.148 - Watch on 156.8 MHz (Channel 16).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Watch on 156.8 MHz (Channel 16). 80.148 Section... Watches § 80.148 Watch on 156.8 MHz (Channel 16). Each compulsory vessel, while underway, must maintain a watch for radiotelephone distress calls on 156.800 MHz whenever such station is not being used...

  19. 47 CFR 27.1300 - 600 MHz band subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false 600 MHz band subject to competitive bidding. 27.1300 Section 27.1300 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 600 MHz Band § 27.1300 600 MHz band subject...

  20. 47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MHz Public/Private Partnership with the licensee of the adjacent Upper 700 MHz D Block license... specific provisions relating to the 700 MHz Public/Private Partnership are set forth in subpart AA of this... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Public Safety Radio Pool § 90.18 Public...

  1. 47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MHz Public/Private Partnership with the licensee of the adjacent Upper 700 MHz D Block license... specific provisions relating to the 700 MHz Public/Private Partnership are set forth in subpart AA of this... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Public Safety Radio Pool § 90.18 Public...

  2. 47 CFR 22.599 - Assignment of 72-76 MHz channels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Assignment of 72-76 MHz channels. 22.599... 72-76 MHz channels. Because of the potential for interference to the reception of TV Channels 4 and 5 by broadcast television sets and video recorders, assignments of the 72-76 MHz channels are...

  3. 47 CFR 22.599 - Assignment of 72-76 MHz channels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Assignment of 72-76 MHz channels. 22.599... 72-76 MHz channels. Because of the potential for interference to the reception of TV Channels 4 and 5 by broadcast television sets and video recorders, assignments of the 72-76 MHz channels are...

  4. Speed of sound in diseased liver observed by scanning acoustic microscopy with 80 MHz and 250 MHz.

    PubMed

    Irie, So; Inoue, Kenta; Yoshida, Kenji; Mamou, Jonathan; Kobayashi, Kazuto; Maruyama, Hitoshi; Yamaguchi, Tadashi

    2016-01-01

    In this study, the speed of sound (SOS) of two types of rat livers (eight normal livers, four cirrhotic livers) was measured with a scanning acoustic microscope using two transducers, one of which had an 80-MHz and the other a 250-MHz center frequency. The 250-MHz transducer had a better spatial resolution adapted to studying fiber or hepatic parenchymal cells. In normal livers, averages of the SOS values were from 1598 to 1677 m/s at 80-MHz and from 1568 to 1668 m/s at 250-MHz. In the fiber tissue of cirrhotic livers, averages of the SOS values were from 1645 to 1658 m/s at 80-MHz and from 1610 to 1695 m/s at 250-MHz, while the SOS values in the other tissue of cirrhotic livers ranged from 1644 to 1709 m/s at 80-MHz and from 1641 to 1715 m/s at 250-MHz. In one liver, SOS in fiber tissue was larger than that of tissues without fiber while in others it was lower. The resulting two-dimensional SOS maps provide a unique quantitative insight of liver acoustic microstructures in a healthy liver and in a cirrhotic ones. This study would be helpful to understand the complex relationship between acoustic properties and liver disease including fiber tissue.

  5. Experimental and simulational result multipactors in 112 MHz QWR injector

    SciTech Connect

    Xin, T.; Ben-Zvi, I.; Belomestnykh, S.; Brutus, J. C.; Skaritka, J.; Wu, Q.; Xiao, B.

    2015-05-03

    The first RF commissioning of 112 MHz QWR superconducting electron gun was done in late 2014. The coaxial Fundamental Power Coupler (FPC) and Cathode Stalk (stalk) were installed and tested for the first time. During this experiment, we observed several multipacting barriers at different gun voltage levels. The simulation work was done within the same range. The comparison between the experimental observation and the simulation results are presented in this paper. The observations during the test are consisted with the simulation predictions. We were able to overcome most of the multipacting barriers and reach 1.8 MV gun voltage under pulsed mode after several round of conditioning processes.

  6. BNL 56 MHz HOM damper prototype fabrication at JLAB

    SciTech Connect

    Huque, N.; McIntyre, G.; Daly, E. F.; Clemens, W.; Wu, Q.; Seberg, S.; Bellavia, S.

    2015-05-03

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider’s (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  7. 13.56 MHz polymer rectifier by printing processes

    NASA Astrophysics Data System (ADS)

    Lin, Chang-Yu; Chou, Chia-Hung; Hou, Jack; Chan, Yi-Jen

    2007-09-01

    Printed electronics have attracted increasing attentions in recent years due to its flexible format, easy process and potentially low cost features. Achieving good performance organic Schottky diode as the key component of a rectifier for printed RFID applications became a critical task. The electrical performances of an organic Schottky diode electrical can be improved by inserting an intermediate layer between the semiconductor and electrode surfaces. This interface plays an important role in improving rectification ratio and lifetime of a polymer diode. In this work, a 13.56MHz rectifier based on a polymer Schottky diode will be demonstrated and a wireless energy transmission built on flexible substrates will be proposed.

  8. Power sources for search and rescue 406 MHz beacons

    NASA Technical Reports Server (NTRS)

    Attia, Alan I.; Perrone, David E.

    1987-01-01

    The results of a study directed at the selection of a commercially available, safe, low cost, light weight and long storage life battery for search and rescue (Sarsat) 406 MHz emergency beacons are presented. In the course of this work, five electrochemical systems (lithium-manganese dioxide, lithium-carbon monofluoride, lithium-silver vanadium oxide, alkaline cells, and cadmium-mercuric oxide) were selected for limited experimental studies to determine their suitability for this application. Two safe, commercially available batteries (lithium-manganese dioxide and lithium-carbon monofluoride) which meet the near term requirements and several alternatives for the long term were identified.

  9. Stabilised electromagnetic levitation at 2-13 MHz

    NASA Technical Reports Server (NTRS)

    Danley, T. J.; Schiffman, R. A.; Weber, J. K. R.; Krishnan, S.; Rey, C. A.; Bruno, P. A.; Nordine, P. C.

    1991-01-01

    SEL, the Stabilised Electromagnetic Levitator, has been developed to exploit the unique design opportunities available in containerless microgravity experiments. Efficiency and versatility are obtained with multiple coils driven by individual broadband amplifiers whose phase and frequency are controlled. The heating and positioning fields are decoupled. Specimen translation, spin, and for liquids, shape may be adjusted. An open coil structure provides access for optical and diagnostic probes. Results of experiments with a prototype device are discussed. Levitating and heating materials on earth were demonstrated at frequencies up to 13 MHz.

  10. Stabilised electromagnetic levitation at 2-13 MHz

    NASA Astrophysics Data System (ADS)

    Danley, T. J.; Schiffman, R. A.; Weber, J. K. R.; Krishnan, S.; Nordine, P. C.; Rey, C. A.; Bruno, P. A.

    SEL, the Stabilized Electromagnetic Levitator, has been developed to exploit the unique design opportunities available in containerless microgravity experiments. Efficiency and versatility are obtained with multiple coils driven by individual broadband amplifiers whose phase and frequency are controlled. The heating and positioning fields are decoupled. Specimen translation, spin, and for liquids, shape, may be adjusted. An open coil structure provides access for optical and diagnostic probes. Results of experiments with a prototype device are discussed. Levitating and heating materials on earth were demonstrated at frequencies up to 13 MHz.

  11. 2250-MHz High Efficiency Microwave Power Amplifier (HEMPA)

    NASA Technical Reports Server (NTRS)

    Sims, W. Herbert; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Tnis paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  12. Design Methodology and Consideratios for NOVA 53 MHZ RF Cavities

    SciTech Connect

    Ader, C.; Wildman, D.W.; /Fermilab

    2010-05-19

    The NO?A Experiment will construct a detector optimized for electron neutrino detection in the existing Neutrino at Main Injector (NuMI) beamline. This beamline is capable of operating at 400 kW of primary beam power and the upgrade will allow up to 700 kW. The cavities will operate at 53 MHz and three of them will be installed in the Recycler beamline. Thermal stability of the cavities is crucial since this affects the tuning. Results of finite element thermal and structural analysis involving the copper RF cavity will be presented.

  13. BNL 56 MHz HOM Damper Prototype Fabrication at JLab

    SciTech Connect

    Huque, Naeem A.; Daly, Edward F.; Clemens, William A.; McIntyre, Gary T.; Wu, Qiong; Seberg, Scott; Bellavia, Steve

    2015-09-01

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider's (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  14. MHz gravitational waves from short-term anisotropic inflation

    SciTech Connect

    Ito, Asuka; Soda, Jiro

    2016-04-18

    We reveal the universality of short-term anisotropic inflation. As a demonstration, we study inflation with an exponential type gauge kinetic function which is ubiquitous in models obtained by dimensional reduction from higher dimensional fundamental theory. It turns out that an anisotropic inflation universally takes place in the later stage of conventional inflation. Remarkably, we find that primordial gravitational waves with a peak amplitude around 10{sup −26}∼10{sup −27} are copiously produced in high-frequency bands 10 MHz∼100 MHz. If we could detect such gravitational waves in future, we would be able to probe higher dimensional fundamental theory.

  15. Development of 325 MHz single spoke resonators at Fermilab

    SciTech Connect

    Apollinari, G.; Gonin, I.V.; Khabiboulline, T.N.; Lanfranco, G.; Mukherjee, A.; Ozelis, J.; Ristori, L.; Sergatskov, D.; Wagner, R.; Webber, R.; /Fermilab

    2008-08-01

    The High Intensity Neutrino Source (HINS) project represents the current effort at Fermilab to produce an 8-GeV proton linac based on 400 independently phased superconducting cavities. Eighteen ?=0.21 single spoke resonators, operating at 325 MHz, comprise the first stage of the linac cold section. In this paper we present the current status of the production and testing of the first two prototype cavities. This includes descriptions of the fabrication, frequency tuning, chemical polishing, high pressure rinse, and high-gradient cold tests.

  16. Fabrication and Measurements of 500 MHz Double Spoke Cavity

    SciTech Connect

    Park, HyeKyoung; Hopper, Christopher S.; Delayen, Jean R.

    2014-12-01

    A 500 MHz β0=1 double spoke cavity has been designed and optimized for a high velocity application such as a compact electron accelerator at the Center for Accelerator Science at Old Dominion University [1] and the fabrication was recently completed at Jefferson Lab. The geometry specific to the double spoke cavity required a variety of tooling and fixtures. Also a number of asymmetric weld joints were expected to make it difficult to maintain minimal geometric deviation from the design. This paper will report the fabrication procedure, resulting tolerance from the design, initial test results and the lessons learned from the first β0=1 double spoke cavity fabrication.

  17. A 1400-MHz survey of 1478 Abell clusters of galaxies

    NASA Technical Reports Server (NTRS)

    Owen, F. N.; White, R. A.; Hilldrup, K. C.; Hanisch, R. J.

    1982-01-01

    Observations of 1478 Abell clusters of galaxies with the NRAO 91-m telescope at 1400 MHz are reported. The measured beam shape was deconvolved from the measured source Gaussian fits in order to estimate the source size and position angle. All detected sources within 0.5 corrected Abell cluster radii are listed, including the cluster number, richness class, distance class, magnitude of the tenth brightest galaxy, redshift estimate, corrected cluster radius in arcmin, right ascension and error, declination and error, total flux density and error, and angular structure for each source.

  18. Sonochemical Effect Using Ultrasonic Atomizer at 2.4 MHz

    NASA Astrophysics Data System (ADS)

    Shinashi, Kiyoaki; Houkin, Toshinori; Harada, Hisashi

    2012-07-01

    Sonochemical reactions were demonstrated using a commercial ultrasonic atomizer at 2.4 MHz. The influences of experimental conditions, bottom shape and glass thickness of reactors, irradiation method, and liquid height on the sonochemical yield were discussed. The sonochemical effect was evaluated by potassium iodide dosimetry and degradation of methylene blue. Direct and indirect irradiations were examined. The former had the highest yield. In the latter case, sonochemical yield decreased in the solution because glass prevented the transmission of ultrasonic waves. Poly film, on the other hand, could transmit ultrasonic waves very well without damage.

  19. High-power circulator test results at 350 and 700 MHz

    SciTech Connect

    Roybal, W.

    2000-08-01

    The high-power RF systems for the Accelerator Production of Tritium (APT) program require high-power circulators at 350 MHz and 700 MHz to protect 1 MW Continuous Wave (CW) klystrons from reflected power. The 350 MHz circulator is based on the CERN, EXF, and APS designs and has performed very well. The 700 MHz circulator is a new design. Prototype 700 MHz circulators have been high-power tested at Los Alamos National Laboratory (LANL). The first of these circulators has satisfied performance requirements. The circulator requirements, results from the testing, and lessons learned from this development are presented and discussed.

  20. 47 CFR 27.201 - WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding. 27.201 Section 27.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES...

  1. 47 CFR 27.201 - WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding. 27.201 Section 27.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES...

  2. 47 CFR 27.201 - WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding. 27.201 Section 27.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES...

  3. 47 CFR 27.77 - Restriction on mobile and portable equipment in the 1695-1710 MHz and 1755-1780 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Restriction on mobile and portable equipment in the 1695-1710 MHz and 1755-1780 MHz bands. 27.77 Section 27.77 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS...

  4. 47 CFR 27.201 - WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false WCS in the 2305-2320 MHz and 2345-2360 MHz bands subject to competitive bidding. 27.201 Section 27.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES...

  5. 47 CFR 90.492 - One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands. 90.492 Section 90.492 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Paging...

  6. 47 CFR 90.492 - One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands. 90.492 Section 90.492 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Paging...

  7. 47 CFR 90.492 - One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands. 90.492 Section 90.492 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Paging...

  8. 47 CFR 90.492 - One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands. 90.492 Section 90.492 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Paging...

  9. 47 CFR 90.492 - One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false One way paging operations in the 806-824/851-869 MHz and 896-901/935-940 MHz bands. 90.492 Section 90.492 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Paging...

  10. 47 CFR 27.1136 - Protection of mobile satellite services in the 2000-2020 MHz and 2180-2200 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Protection of mobile satellite services in the... Operations § 27.1136 Protection of mobile satellite services in the 2000-2020 MHz and 2180-2200 MHz bands. An... duly authorized mobile satellite service operations in these bands. Any such AWS licensees must...

  11. 47 CFR 27.1136 - Protection of mobile satellite services in the 2000-2020 MHz and 2180-2200 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Protection of mobile satellite services in the... Protection of mobile satellite services in the 2000-2020 MHz and 2180-2200 MHz bands. An AWS licensee of the... satellite service operations in these bands. Any such AWS licensees must protect mobile satellite...

  12. Synchrotron Spectral Curvature from 22 MHZ to 23 GHZ

    NASA Technical Reports Server (NTRS)

    Kogut, Alan J.

    2012-01-01

    We combine surveys of the radio sky at frequencies 22 MHz to 1.4 GHz with data from the ARCADE-2 instrument at frequencies 3 GHz to 10 GHz to characterize the frequency spectrum of diffuse synchrotron emission in the Galaxy. The radio spectrum steepens with frequency from 22 MHz to 10 GHz. The projected spectral index at 23 GHz derived from the low-frequency data agrees well with independent measurements using only data at frequencies 23 GHz and above. Comparing the spectral index at 23 GHz to the value from previously published analyses allows extension of the model to higher frequencies. The combined data are consistent with a power-law index beta = -2.64 +/-= 0.03 at 0.31 GHz, steepening by an amount of Delta-beta = 0.07 every octave in frequency. Comparison of the radio data to models including the cosmic-ray energy spectrum suggests that any break in the synchrotron spectrum must occur at frequencies above 23 GHz.

  13. Design and fabrication of a 40-MHz annular array transducer

    PubMed Central

    Ketterling, Jeffrey A.; Lizzi, Frederic L.; Aristizábal, Orlando; Turnbull, Daniel H.

    2006-01-01

    This paper investigates the feasibility of fabricating a 5-ring, focused annular array transducer operating at 40 MHz. The active piezoelectric material of the transducer was a 9-μm thick polyvinylidene fluoride (PVDF) film. One side of the PVDF was metallized with gold and forms the ground plane of the transducer. The array pattern of the transducer and electrical traces to each annulus were formed on a copper-clad polyimide film. The PVDF and polyimide were bonded with a thin layer of epoxy, pressed into a spherically curved shape, and then back filled with epoxy. A 5-ring transducer with equal area elements and 100 μm kerfs between annuli was fabricated and tested. The transducer had a total aperture of 6 mm and a geometric focus of 12 mm. The pulse/echo response from a quartz plate located at the geometric focus, two-way insertion loss (IL), complex impedance, electrical cross-talk, and lateral beamwidth were all measured for each annulus. The complex impedance data from each element were used to perform electrical matching and the measurements were repeated. After impedance matching, fc ≈ 36 MHz and BWs ranged from 31 to 39%. The ILs for the matched annuli ranged from −28 to −38 dB. PMID:16060516

  14. Experimental Limits on Gravitational Waves in the MHz frequency Range

    SciTech Connect

    Lanza, Robert Jr.

    2015-03-01

    This thesis presents the results of a search for gravitational waves in the 1-11MHz frequency range using dual power-recycled Michelson laser interferometers at Fermi National Accelerator Laboratory. An unprecedented level of sensitivity to gravitational waves in this frequency range has been achieved by cross-correlating the output fluctuations of two identical and colocated 40m long interferometers. This technique produces sensitivities better than two orders of magnitude below the quantum shot-noise limit, within integration times of less than 1 hour. 95% confidence level upper limits are placed on the strain amplitude of MHz frequency gravitational waves at the 10-21 Hz-1/2 level, constituting the best direct limits to date at these frequencies. For gravitational wave power distributed over this frequency range, a broadband upper limit of 2.4 x 10-21Hz-1/2 at 95% confidence level is also obtained. This thesis covers the detector technology, the commissioning and calibration of the instrument, the statistical data analysis, and the gravitational wave limit results. Particular attention is paid to the end-to-end calibration of the instrument’s sensitivity to differential arm length motion, and so to gravitational wave strain. A detailed statistical analysis of the data is presented as well.

  15. Constraints on the FRB rate at 700-900 MHz

    NASA Astrophysics Data System (ADS)

    Connor, Liam; Lin, Hsiu-Hsien; Masui, Kiyoshi; Oppermann, Niels; Pen, Ue-Li; Peterson, Jeffrey B.; Roman, Alexander; Sievers, Jonathan

    2016-07-01

    Estimating the all-sky rate of fast radio bursts (FRBs) has been difficult due to small-number statistics and the fact that they are seen by disparate surveys in different regions of the sky. In this paper we provide limits for the FRB rate at 800 MHz based on the only burst detected at frequencies below 1.4 GHz, FRB 110523. We discuss the difficulties in rate estimation, particularly in providing an all-sky rate above a single fluence threshold. We find an implied rate between 700 and 900 MHz that is consistent with the rate at 1.4 GHz, scaling to 6.4^{+29.5}_{-5.0} × 10^3 sky-1 d-1 for an HTRU-like survey. This is promising for upcoming experiments below a GHz like CHIME and UTMOST, for which we forecast detection rates. Given 110523's discovery at 32σ with nothing weaker detected, down to the threshold of 8σ, we find consistency with a Euclidean flux distribution but disfavour steep distributions, ruling out γ > 2.2.

  16. Programmable 10 MHz optical fiducial system for hydrodiagnostic cameras

    SciTech Connect

    Huen, T.

    1987-07-01

    A solid state light control system was designed and fabricated for use with hydrodiagnostic streak cameras of the electro-optic type. With its use, the film containing the streak images will have on it two time scales simultaneously exposed with the signal. This allows timing and cross timing. The latter is achieved with exposure modulation marking onto the time tick marks. The purpose of using two time scales will be discussed. The design is based on a microcomputer, resulting in a compact and easy to use instrument. The light source is a small red light emitting diode. Time marking can be programmed in steps of 0.1 microseconds, with a range of 255 steps. The time accuracy is based on a precision 100 MHz quartz crystal, giving a divided down 10 MHz system frequency. The light is guided by two small 100 micron diameter optical fibers, which facilitates light coupling onto the input slit of an electro-optic streak camera. Three distinct groups of exposure modulation of the time tick marks can be independently set anywhere onto the streak duration. This system has been successfully used in Fabry-Perot laser velocimeters for over four years in our Laboratory. The microcomputer control section is also being used in providing optical fids to mechanical rotor cameras.

  17. Very High Frequency (Beyond 100 MHz) PZT Kerfless Linear Arrays

    PubMed Central

    Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K. Kirk

    2010-01-01

    This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-µm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-µm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss). PMID:19942516

  18. Description of a New 400 MHZ Bandwidth Chirp Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Paganini, Lucas; Hartogh, Paul

    A new chirp transform spectrometer (CTS) with a bandwidth of 400 MHz and a spectral resolution of 100 kHz has been developed. The CTS is deviced using a digital chirp generator and a preprocessing unit based on a Complementary Metal Oxide Semiconductor (CMOS) and an Application-Specific Integrated Circuit (ASIC). A build in PC 104 computer handles the process control and the external communication via Ethernet and a Transistor-Transistor Logic (TTL) interface. The CTS has been applied to atmospheric science, i.e., a 25-K noise temperature, 22-GHz water vapor, and a 142-GHz ozone system. Astronomical observations have been performed using the Heinrich Hertz submillimeter telescope. In this paper, we describe the function of the CTS and provide information about its functional performance.

  19. A 20 MHz CMOS reorder buffer for a superscalar microprocessor

    NASA Technical Reports Server (NTRS)

    Lenell, John; Wallace, Steve; Bagherzadeh, Nader

    1992-01-01

    Superscalar processors can achieve increased performance by issuing instructions out-of-order from the original sequential instruction stream. Implementing an out-of-order instruction issue policy requires a hardware mechanism to prevent incorrectly executed instructions from updating register values. A reorder buffer can be used to allow a superscalar processor to issue instructions out-of-order and maintain program correctness. This paper describes the design and implementation of a 20MHz CMOS reorder buffer for superscalar processors. The reorder buffer is designed to accept and retire two instructions per cycle. A full-custom layout in 1.2 micron has been implemented, measuring 1.1058 mm by 1.3542 mm.

  20. Overview of MHz air shower radio experiments and results

    NASA Astrophysics Data System (ADS)

    Revenu, Benoît

    2013-05-01

    In this paper, I present a review of the main results obtained in the last 10 years in the field of radio-detection of cosmic-ray air showers in the MHz range. All results from all experiments cannot be reported here so that I will focus on the results more than on the experiments themselves. Modern experiments started in 2003 with CODALEMA and LOPES. In 2006, small-size autonomous prototypes setup were installed at the Pierre Auger Observatory site, to help the design of the Auger Engineering Radio Array (AERA). We will discuss the principal aspects of the radio data analysis and the determination of the primary cosmic ray characteristics: the arrival direction, the lateral distribution of the electric field, the correlation with the primary energy, the emission mechanisms and the sensitivity to the composition of the cosmic rays.

  1. Biological studies with continuous-wave radiofrequency (28 MHz) radiation

    SciTech Connect

    Wright, N.A.; Borland, R.G.; Cookson, J.H.; Coward, R.F.; Davies, J.A.; Nicholson, A.N.; Christie, J.L.; Flanagan, N.G.; Goodridge, V.D.

    1984-03-01

    Effects of high-frequency (28 MHz) continous-wave radiation have been studied in the rat and monkey. No histopathological or hematological changes could be attributed to the radiation. In the monkey there was an increase in urinary calcium concentration which was most likely due to restricted movement. In the rat there was reduced uptake of iodine by the thyroid, lower levels of plasma thyroid-stimulating hormone, and reduced ratio of protein bound to nonprotein bound iodine. Food consumption was also decreased. The changes are likely to have arisen as a compensatory response to an induced heat load. A nonthermal effect of continuous-wave high-frequency radiation has not been shown in this study. The effects were likely to be associated with either physiological compensation for induced heating or restriction of movement.

  2. 201 MHz Cavity R&D for MUCOOL and MICE

    SciTech Connect

    Li, Derun; Virostek, Steve; Zisman, Michael; Norem, Jim; Bross,Alan; Moretti, Alfred; Norris, Barry; Torun, Yagmur; Phillips, Larry; Rimmer, Robert; Stirbet, Mircea; Reep, Michael; Summers, Don

    2006-06-23

    We describe the design, fabrication, analysis and preliminary testing of the prototype 201 MHz copper cavity for a muon ionization cooling channel. Cavity applications include the Muon Ionization Cooling Experiment (MICE) as well as cooling channels for a neutrino factory or a muon collider. This cavity was developed by the US muon cooling (MUCOOL) collaboration and is being tested in the MUCOOL Test Area (MTA) at Fermilab. To achieve a high accelerating gradient, the cavity beam irises are terminated by a pair of curved, thin beryllium windows. Several fabrication methods developed for the cavity and windows are novel and offer significant cost savings as compared to conventional construction methods. The cavity's thermal and structural performances are simulated with an FEA model. Preliminary high power RF commissioning results will be presented.

  3. 915-MHz Radar Wind Profiler (915RWP) Handbook

    SciTech Connect

    Coulter, R

    2005-01-01

    The 915 MHz radar wind profiler/radio acoustic sounding system (RWP/RASS) measures wind profiles and backscattered signal strength between (nominally) 0.1 km and 5 km and virtual temperature profiles between 0.1 km and 2.5 km. It operates by transmitting electromagnetic energy into the atmosphere and measuring the strength and frequency of backscattered energy. Virtual temperatures are recovered by transmitting an acoustic signal vertically and measuring the electromagnetic energy scattered from the acoustic wavefront. Because the propagation speed of the acoustic wave is proportional to the square root of the virtual temperature of the air, the virtual temperature can be recovered by measuring the Doppler shift of the scattered electromagnetic wave.

  4. Developments of 700-Mhz 5-Cell Superconducting Cavities for APT

    SciTech Connect

    T. Tajima; K. C. D. Chan; R. C. Gentzlinger; W. B. Haynes; J. P. Kelley; F. L. Krawczyk; M. A. Madrid; D. I. Montoya; D. L. Schrage; A. H. Shapiro; J. Mammosser

    2001-07-01

    We have manufactured a total of six {beta} = 0.64, 700-MHz 5-cell cavities. The APT (Accelerator Production of Tritium) specification requires Q{sub 0} > 5 x 10{sup 9} at an accelerating field of 5 MV/m. So far, the results of vertical tests have shown maximum accelerating fields of 12 MV/m (peak surface field of 41 MV/m) and maximum low-field Q{sub 0} of 3.6 x 10{sup 10} at 2 K. The present limitations are available input power, field emission and quench. This type of cavities will also be used for an ADTF (Accelerator-Driven Test Facility) for AAA (Advanced Accelerator Applications) project.

  5. Natural noise above 50 MHZ from terrestrial and extraterrestrial sources

    NASA Technical Reports Server (NTRS)

    Smith, E. K.; Flock, W. L.

    1991-01-01

    This paper offers a brief overview of natural radio noise for frequencies above 50 MHz in terms of brightness temperature as observed from two vantage points. The first is from an Earth station located at 40 degrees north latitude and observing at elevation angles from 0 to 90 degrees with an ideal antenna. The second is a satellite in geostationary orbit communicating with the Earth. Earth station noise at VHF and UHF is dominated by galactic and solar noise. Emission from the atmosphere, gases and hydrometeors, are dominant at EHF and SHF. Radiative transfer theory is invoked in the calculation of brightness temperature from the atmosphere. The situation is not vastly different from geostationary orbit if communications is with the Earth. Emission from the land and sea, even under idealized conditions, enters significantly. Land is a much more effective emitter than sea water, but at frequencies above 30 GHz the differential becomes much less due to the increasing significance of atmospheric emission.

  6. Mobility Studies on Nitroxyl Radicals using ESR 300 MHz Spectrometer

    NASA Astrophysics Data System (ADS)

    Dhas, M. Kumara; Franklin Benial, A. Milton; Jawahar, A.

    2011-07-01

    The mobility studies on 14N labeled TEMPOL, carboxy PROXYL, carbamoyl PROXYL in pure water, pure water and glycerol at ratio (15:85) was carried out using 300 MHz ESR spectrometer. The ESR parameters such as linewidth, signal intensity ratio and correlation time were determined. The isotropic g-factor and hyperfine coupling constant were also estimated. This ESR study reveals that the dipolar and spin exchange interactions are less in the 14N labeled TEMPOL radical. This phenomenon can be explained in terms of the structural, physical and chemical properties of the TEMPOL molecule. The mobility of TEMPOL radical is not much affected by the high viscous medium. Hence the TEMPOL radical can be used as a good spin probe in high viscous medium.

  7. A 75 MHz light source for femtosecond stimulated raman microscopy.

    PubMed

    Ploetz, E; Marx, B; Klein, T; Huber, R; Gilch, P

    2009-10-12

    In femtosecond stimulated Raman microscopy (FSRM) a spectrally broad pulse (Raman probe) and a spectrally narrow pulse (Raman pump) interact in a sample and thereby generate a Raman spectrum of the focal volume. Here a novel light source for FSRM is presented. It consists of an 8-fs laser (repetition rate of 75 MHz) operating as Raman probe. A Yb(3+) based fiber amplifier generates the Raman pump light at 980 nm. The amplifier is seeded by the spectral wing of the 8-fs laser output which ensures synchronisation of pump and probe pulses. Spectral and temporal characteristics of these pulses are reported and simultaneous recording of broadband Raman spectra relying on these pulses is demonstrated.

  8. Multipacting optimization of a 750 MHz rf dipole

    SciTech Connect

    Delayen, Jean R.; Castillo, Alejandro

    2014-12-01

    Crab crossing schemes have been proposed to re-instate luminosity degradation due to crossing angles at the interaction points in next generation colliders to avoid the use of sharp bending magnets and their resulting large synchrotron radiation generation, highly undessirable in the detector region. The rf dipole has been considered for a different set of applications in several machines, both rings and linear colliders. We present in this paper a study of the effects on the multipacting levels and location depending on geometrical variations on the design for a crabbing/deflecting application in a high current (3/0.5 A), high repetition (750 MHz) electron/proton collider, as a matter to provide a comparison point for similar applications of rf dipoles.

  9. 1612 MHz OH maser emission from axisymmetric circumstellar envelopes - Miras

    NASA Technical Reports Server (NTRS)

    Collison, Alan J.; Fix, John D.

    1992-01-01

    Radiative transfer calculations are performed using a modified form of the Sobolev approximation to determine the inversion of the 1612 MHz line of OH in axisymmetric circumstellar envelopes around Miras. The mass loss is assumed to be occurring in the form of a smooth wind. Line profiles and maps are presented for three models of varying degrees of asymmetry and for various orientations of the envelopes. It is concluded that the axisymmetric models can reproduce many of the features of observed profiles and maps which both the standard, spherically symmetric model and the discrete emission model cannot easily explain. The model profiles reproduce all of the general features seen in the line profiles of real sources.

  10. The first operation of 56 MHz SRF cavity in RHIC

    SciTech Connect

    Wu, Q.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M.; DeSanto, L.; Goldberg, D.; Harvey, M.; Hayes, T.; McIntyre, G.; Mernick, K.; Orfin, P.; Seberg, S.; Severino, F.; Smith, K.; Than, R.; Zaltsman, A.

    2015-05-03

    A 56 MHz superconducting RF cavity has been designed, fabricated and installed in the Relativistic Heavy Ion Collider (RHIC). The cavity operates at 4.4 K with a “quiet helium source” to isolate the cavity from environmental acoustic noise. The cavity is a beam driven quarter wave resonator. It is detuned and damped during injection and acceleration cycles and is brought to operation only at store energy. For a first test operation, the cavity voltage was stabilized at 300 kV with full beam current. Within both Au + Au and asymmetrical Au + He3 collisions, luminosity improvement was detected from direct measurement, and the hourglass effect was reduced. One higher order mode (HOM) coupler was installed on the cavity. We report in this paper on our measurement of a broadband HOM spectrum excited by the Au beam.

  11. Hydrophone spatial averaging corrections from 1 to 100 MHz

    NASA Astrophysics Data System (ADS)

    Radulescu, Emil George

    The purpose of this work was to develop and experimentally verify a set of robust and readily applicable spatial averaging models to account for ultrasonic hydrophone probe's finite aperture in acoustic field measurements in the frequency range 1--100 MHz. Electronically and mechanically focused acoustic sources of different geometries were considered. The geometries included single element circular sources and rectangular shape transducers that were representative of ultrasound imaging arrays used in clinical diagnostic applications. The field distributions of the acoustic sources were predicted and used in the development of the spatial averaging models. The validity of the models was tested using commercially available hydrophone probes having active element diameters ranging from 50 to 1200 mum. The models yielded guidelines which were applicable to both linear and nonlinear wave propagation conditions. By accounting for hydrophones' finite aperture and correcting the recorded pressure-time waveforms, the models allowed the uncertainty associated with determining the key acoustic output parameters such as: Pulse Intensity Integral (PII) and the intensities derived from it to be minimized. In addition, the work offered a correction factor for the safety indicator Mechanical Index (MI) that is required by AIUM/NEMA standards. The novelty of this research stems primarily from the fact that, to the best of the author's knowledge, such comprehensive set of models and guidelines has not been developed so far. Although different spatial averaging models have already been suggested, they have been limited to circular geometries, linear propagation conditions and conventional, low megahertz medical imaging frequencies, only. Also, the spatial averaging models described here provided the necessary corrections to obtain the true sensitivity versus frequency response during calibration of hydrophone probes up to 100 MHz and allowed for a subsequent development of two novel

  12. 75 FR 45496 - Amendment of the Commission's Rules to Accommodate 30 Megahertz Channels in the 6525-6875 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... COMMISSION 47 CFR Part 101 Amendment of the Commission's Rules to Accommodate 30 Megahertz Channels in the 6525 6875 MHz Band; and to Provide for Conditional Authorization on Additional Channels in the 21.8 22...) * * * Receive Transmit (receive) (MHz) (transmit) (MHz) (3) 10 MHz bandwidth channels: * * * * * 22025 \\2\\...

  13. Beam dynamics and expected RHIC performance with 56MHz RF upgrade

    SciTech Connect

    Fedotov,A.V.; Ben-Zvi, I.

    2009-05-04

    An upgrade of the RHIC storage RF system with a superconducting 56 MHz cavity was recently proposed. This upgrade will provide a significant increase in the acceptance of the RHIC 197 MHz storage RF bucket. This paper summarizes simulations of beam evolution due to intra-beam scattering (IBS) for beam parameters expected with the 56 MHz SRF cavity upgrade. Expected luminosity improvements are shown for Au ions at 100 GeV/nucleon and protons at 250 GeV.

  14. Radiation Characterization of an Intra-Oral Wireless Device at Multiple ISM Bands: 433 MHz, 915 MHz, and 2.42 GHz

    PubMed Central

    Huo, Xueliang; Jow, Uei-Ming

    2010-01-01

    Intra-oral wireless devices are becoming more popular for physiological monitoring of the mouth environment and tongue-operated assistive technologies, such as the internal Tongue Drive System (iTDS). Here we present the experimental measurements and simulations of radiation performance of three commercial wireless transmitters operating at 433 MHz, 915 MHz, and 2.42 GHz, in the industrial-scientific-medical band when they were placed inside human mouth. The measurement and simulation results showed similarities in the attenuation patterns of all tested devices and indicated that the maximum attenuation occurs on the back of the head. There were no significant difference of average attenuation pattern between 433 MHz and 915 MHz, while the attenuation of 2.42 GHz was higher in simulations but not in the measurements. PMID:21096348

  15. Fast 704 MHz Ferroelectric Tuner for Superconducting Cavities

    SciTech Connect

    Jay L. Hirshfield

    2012-04-12

    The Omega-P SBIR project described in this Report has as its goal the development, test, and evaluation of a fast electrically-controlled L-band tuner for BNL Energy Recovery Linac (ERL) in the Electron Ion Collider (EIC) upgrade of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The tuner, that employs an electrically-controlled ferroelectric component, is to allow fast compensation to cavity resonance changes. In ERLs, there are several factors which significantly affect the amount of power required from the wall-plug to provide the RF-power level necessary for the operation. When beam loading is small, the power requirements are determined by (i) ohmic losses in cavity walls, (ii) fluctuations in amplitude and/or phase for beam currents, and (iii) microphonics. These factors typically require a substantial change in the coupling between the cavity and the feeding line, which results in an intentional broadening of the cavity bandwidth, which in turn demands a significant amount of additional RF power. If beam loading is not small, there is a variety of beam-drive phase instabilities to be managed, and microphonics will still remain an issue, so there remain requirements for additional power. Moreover ERL performance is sensitive to changes in beam arrival time, since any such change is equivalent to phase instability with its vigorous demands for additional power. In this Report, we describe the new modular coaxial tuner, with specifications suitable for the 704 MHz ERL application. The device would allow changing the RF-coupling during the cavity filling process in order to effect significant RF power savings, and also will provide rapid compensation for beam imbalance and allow for fast stabilization against phase fluctuations caused by microphonics, beam-driven instabilities, etc. The tuner is predicted to allow a reduction of about ten times in the required power from the RF source, as compared to a compensation system

  16. Neoplastic transformation in C3H 10T(1/2) cells after exposure to 835.62 MHz FDMA and 847.74 MHz CDMA radiations.

    PubMed

    Roti Roti JL; Malyapa, R S; Bisht, K S; Ahern, E W; Moros, E G; Pickard, W F; Straube, W L

    2001-01-01

    The effect of radiofrequency (RF) radiation in the cellular phone communication range (835.62 MHz frequency division multiple access, FDMA; 847.74 MHz code division multiple access, CDMA) on neoplastic transformation frequency was measured using the in vitro C3H 10T(1/2) cell transformation assay system. To determine if 835.62 MHz FDMA or 847.74 MHz CDMA radiations have any genotoxic effects that induce neoplastic transformation, C3H 10T(1/2) cells were exposed at 37 degrees C to either of the above radiations [each at a specific absorption rate (SAR) of 0.6 W/kg] or sham-exposed at the same time for 7 days. After the culture medium was changed, the cultures were transferred to incubators and refed with fresh growth medium every 7 days. After 42 days, the cells were fixed and stained with Giemsa, and transformed foci were scored. To determine if exposure to 835.62 MHz FDMA or 847.74 MHz CDMA radiation has any epigenetic effects that can promote neoplastic transformation, cells were first exposed to 4.5 Gy of X rays to induce the transformation process and then exposed to the above radiations (SAR = 0.6 W/kg) in temperature-controlled irradiators with weekly refeeding for 42 days. After both the 7-day RF exposure and the 42-day RF exposure after X irradiation, no statistically significant differences in the transformation frequencies were observed between incubator controls, the sham-exposed (maintained in irradiators without power to the antenna), and the 835.62 MHz FDMA or 847.74 MHz CDMA-exposed groups.

  17. Commissioning of the 112 MHz SRF Gun and 500 MHz bunching cavities for the CeC PoP Linac

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Litvinenko, V.; McIntosh, P.; Moss, A.; Narayan, G.; Orfin, P.; Pinayev, I.; Rao, T.; Skaritka, J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Wheelhouse, A.; Wu, Q.; Xiao, B.; Xin, T.; Xu, W.; Zaltsman, A.

    2015-05-03

    The Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment at BNL includes a short electron linac. During Phase 1, a 112 MHz superconducting RF photo-emission gun and two 500 MHz normal conducting bunching cavities were installed and are under commissioning. The paper describes the Phase1 linac layout and presents commissioning results for the cavities and associated RF, cryogenic and other sub-systems

  18. An ionization duct explanation of some plasma line observations with a 46.8-MHz radar and with a 430-MHz radar

    NASA Astrophysics Data System (ADS)

    Muldrew, D. B.

    1985-07-01

    Recently published HF-enhanced plasma line observations using a 46.8-MHz radar show that the upshifted decay line is absent. The upshifted spectrum considered of a single 'growing line' within a few hertz of 51.9 MHz (46.8 MHz plus the heating wave frequency of 5.1 MHz). The downshifted line was obscured by interference. The authors explain their observations by considering Langmuir wave propagation in the electron density depression generated by the ponderomotive force of the heating wave near reflection. Another approach, considered here, is to consider Langmuir wave propagation in magnetic field-aligned ionization ducts which are generated by the HF heating wave. This latter approach appears to yield a more satisfactory explanation of the observations. Using the duct model, it is predicted that for a radar frequency near 50 MHz the downshifted decay line will have a higher intensity and occur at a lower altitude than the upshifed decay line. Some published observations showing an 'early rise' time for the plasma line using a 430-MHz radar can also be explained using the duct model.

  19. RF breakdown of 805 MHz cavities in strong magnetic fields

    SciTech Connect

    Bowring, D.; Stratakis, D.; Kochemirovskiy, A.; Leonova, M.; Moretti, A.; Palmer, M.; Peterson, D.; Yonehara, K.; Freemire, B.; Lane, P.; Torun, Y.; Haase, A.

    2015-05-03

    Ionization cooling of intense muon beams requires the operation of high-gradient, normal-conducting RF structures in the presence of strong magnetic fields. We have measured the breakdown rate in several RF cavities operating at several frequencies. Cavities operating within solenoidal magnetic fields B > 0.25 T show an increased RF breakdown rate at lower gradients compared with similar operation when B = 0 T. Ultimately, this breakdown behavior limits the maximum safe operating gradient of the cavity. Beyond ionization cooling, this issue affects the design of photoinjectors and klystrons, among other applications. We have built an 805 MHz pillbox-type RF cavity to serve as an experimental testbed for this phenomenon. This cavity is designed to study the problem of RF breakdown in strong magnetic fields using various cavity materials and surface treatments, and with precise control over sources of systematic error. We present results from tests in which the cavity was run with all copper surfaces in a variety of magnetic fields.

  20. Merged and corrected 915 MHz Radar Wind Profiler moments

    SciTech Connect

    Jonathan Helmus,Virendra Ghate, Frederic Tridon

    2014-06-25

    The radar wind profiler (RWP) present at the SGP central facility operates at 915 MHz and was reconfigured in early 2011, to collect key sets of measurements for precipitation and boundary layer studies. The RWP is configured to run in two main operating modes: a precipitation (PR) mode with frequent vertical observations and a boundary layer (BL) mode that is similar to what has been traditionally applied to RWPs. To address issues regarding saturation of the radar signal, range resolution and maximum range, the RWP PR mode is set to operate with two different pulse lengths, termed as short pulse (SP) and long pulse (LP). Please refer to the RWP handbook (Coulter, 2012) for further information. Data from the RWP PR-SP and PR-LP modes have been extensively used to study deep precipitating clouds, especially their dynamical structure as the RWP data does not suffer from signal attenuation during these conditions (Giangrande et al., 2013). Tridon et al. (2013) used the data collected during the Mid-latitude Continental Convective Cloud Experiment (MC3E) to improve the estimation of noise floor of the RWP recorded Doppler spectra.

  1. Delivering Agents Locally into Articular Cartilage by Intense MHz Ultrasound

    PubMed Central

    Nieminen, Heikki J.; Ylitalo, Tuomo; Suuronen, Jussi-Petteri; Rahunen, Krista; Salmi, Ari; Saarakkala, Simo; Serimaa, Ritva; Hæggström, Edward

    2015-01-01

    There is no cure for osteoarthritis. Current drug delivery relies on systemic delivery or injections into the joint. Because articular cartilage (AC) degeneration can be local and drug exposure outside the lesion can cause adverse effects, localized drug delivery could permit new drug treatment strategies. We investigated whether intense megahertz ultrasound (frequency: 1.138 MHz, peak positive pressure: 2.7 MPa, Ispta: 5 W/cm2, beam width: 5.7 mm at −6 dB, duty cycle: 5%, pulse repetition frequency: 285 Hz, mechanical index: 1.1) can deliver agents into AC without damaging it. Using ultrasound, we delivered a drug surrogate down to a depth corresponding to 53% depth of the AC thickness without causing histologically detectable damage to the AC. This may be important because early osteoarthritis typically exhibits histopathologic changes in the superficial AC. In conclusion, we identify intense megahertz ultrasound as a technique that potentially enables localized non-destructive delivery of osteoarthritis drugs or drug carriers into articular cartilage. PMID:25922135

  2. Modulation improvements in the 201 MHZ RF generators at LAMPF

    SciTech Connect

    Parsons, W M; Lyles, J T.M.; Harris, H W

    1992-01-01

    Radio-frequency generators, operating at 201 MHz, power the first four stages of the Los Alamos Meson Physics Facility (LAMPF) accelerator. Each generator consists of four stages of seriesconnected, vacuum-tube amplifiers. The modulation scheme for each stage is different. The fist amplifier is a grid-modulated tetrode that produces 500 W peak-power. The second amplifier is a drive-modulated tetrode that produces 5 kill peak-power. The third stage is a grid- and plate-modulated tetrode that produces 130 kill peak-power. The last stage is a plate-modulated triode that produces 2.5 MW peak power. A modernization program has been initiated to improve the reliability of each of these stages. The first two stages of each generator are being replaced with a single, drive-modulated, solid-state amplifier. Specifications for the amplifier design, and requirements for integration into the system are presented. The third stage will be converted to a drive-modulated system using the current tetrode. This modification involves the development of a 17-kV, 15-A switching supply to replace the present plate-modulator. Design requirements for this switching supply are presented. The final stage will remain plate-modulated but will contain a new driver unit for the modulator tube.

  3. Adaptive optics optical coherence tomography at 1 MHz

    PubMed Central

    Kocaoglu, Omer P.; Turner, Timothy L.; Liu, Zhuolin; Miller, Donald T.

    2014-01-01

    Image acquisition speed of optical coherence tomography (OCT) remains a fundamental barrier that limits its scientific and clinical utility. Here we demonstrate a novel multi-camera adaptive optics (AO-)OCT system for ophthalmologic use that operates at 1 million A-lines/s at a wavelength of 790 nm with 5.3 μm axial resolution in retinal tissue. Central to the spectral-domain design is a novel detection channel based on four high-speed spectrometers that receive light sequentially from a 1 × 4 optical switch assembly. Absence of moving parts enables ultra-fast (50ns) and precise switching with low insertion loss (−0.18 dB per channel). This manner of control makes use of all available light in the detection channel and avoids camera dead-time, both critical for imaging at high speeds. Additional benefit in signal-to-noise accrues from the larger numerical aperture afforded by the use of AO and yields retinal images of comparable dynamic range to that of clinical OCT. We validated system performance by a series of experiments that included imaging in both model and human eyes. We demonstrated the performance of our MHz AO-OCT system to capture detailed images of individual retinal nerve fiber bundles and cone photoreceptors. This is the fastest ophthalmic OCT system we know of in the 700 to 915 nm spectral band. PMID:25574431

  4. Dynamic Nuclear Polarization at 700 MHz/460 GHz

    PubMed Central

    Barnes, Alexander B.; Markhasin, Evgeny; Daviso, Eugenio; Michaelis, Vladimir K.; Nanni, Emilio A.; Jawla, Sudheer; Mena, Elijah L.; DeRocher, Ronald; Thakkar, Ajay; Woskov, Paul; Herzfeld, Judith; Temkin, Richard J.; Griffin, Robert G.

    2014-01-01

    We describe the design and implementation of the instrumentation required to perform DNP-NMR at higher field strengths than previously demonstrated, and report the first magic-angle spinning (MAS) DNP-NMR experiments performed at H/e frequencies of 700 MHz/460 GHz. The extension of DNP-NMR to 16.4 T has required the development of probe technology, cryogenics, gyrotrons, and microwave transmission lines. The probe contains a 460 GHz microwave channel, with corrugated waveguide, tapers, and miter-bends that couple microwave power to the sample. Experimental efficiency is increased by a cryogenic exchange system for 3.2 mm rotors within the 89 mm bore. Sample temperatures ≤85 K, resulting in improved DNP enhancements, are achieved by a novel heat exchanger design, stainless steel and brass vacuum jacketed transfer lines, and a bronze probe dewar. In addition, the heat exchanger is preceded with a nitrogen drying and generation system in series with a pre-cooling refrigerator. This reduces liquid nitrogen usage from >400 liters per day to <100 liters per day and allows for continuous (>7 days) cryogenic spinning without detrimental frost or ice formation. Initial enhancements, ε=−40, and a strong microwave power dependence suggests the possibility for considerable improvement. Finally, two-dimensional spectra of a model system demonstrate that the higher field provides excellent resolution, even in a glassy, cryoprotecting matrix. PMID:23000974

  5. Solar S-bursts at Frequencies of 10 - 30 MHz

    NASA Astrophysics Data System (ADS)

    Melnik, V. N.; Konovalenko, A. A.; Rucker, H. O.; Dorovskyy, V. V.; Abranin, E. P.; Lecacheux, A.; Lonskaya, A. S.

    2010-06-01

    Solar S-bursts observed by the radio telescope UTR-2 in the period 2001 - 2002 are studied. The bursts chosen for a detailed analysis occurred in the periods 23 - 26 May 2001, 13 - 16 and 27 - 39 July 2002 during three solar radio storms. More than 800 S-bursts were registered in these days. Properties of S-bursts are studied in the frequency band 10 - 30 MHz. All bursts were always observed against a background of other solar radio activity such as type III and IIIb bursts, type III-like bursts, drift pairs and spikes. Moreover, S-bursts were observed during days when the active region was situated near the central meridian. Characteristic durations of S-bursts were about 0.35 and 0.4 - 0.6 s for the May and July storms, respectively. For the first time, we found that the instantaneous frequency width of S-bursts increased with frequency linearly. The dependence of drift rates on frequency followed the McConnell dependence derived for higher frequencies. We propose a model of S-bursts based on the assumption that these bursts are generated due to the confluence of Langmuir waves with fast magnetosonic waves, whose phase and group velocities are equal.

  6. Fade Measurements into Buildings from 500 to 3000 MHz

    NASA Technical Reports Server (NTRS)

    Vogel, Wolfhard J.; Torrence, Geoffrey W.

    1996-01-01

    Slant-path fade measurements from 500 to 3000 MHz were made into six different buildings employing a vector network analyzer, a tower-mounted transmitting antenna and an automatically positioned receiving antenna. The objective of the measurements was to provide information for satellite audio broadcasting and personal communications satellite design on the correlation of fading inside buildings. Fades were measured with 5 cm spatial separation and every 0.2% of the frequency. Median fades ranged from 10 to 20 dB in woodframe houses with metal roofs and walls without and with an aluminum heatshield, respectively. The median decorrelation distance was from 0.5 to 1.1 m and was independent of frequency. The attenuation into the buildings increased only moderately with frequency in most of the buildings with a median slope of about 1 to 3 dB/GHz, but increased fastest in the least attenuating building with a slope of 5 dB/GHz. The median decorrelation bandwidth ranged from 1.2 to 3.8% of frequency in five of the buildings, and was largest in the least attenuating building, with 20.2% of frequency.

  7. Fade Measurements into Buildings from 500 to 3000 MHz

    NASA Technical Reports Server (NTRS)

    Vogel, Wolfhard J.; Torrence, Geoffrey W.

    1996-01-01

    Slant-path fade measurements from 500 to 3000 MHz were made into six different buildings employing a vector network analyzer, a tower-mounted transmitting antenna and an automatically positioned receiving antenna. The objective of the measurements was to provide information for satellite audio broadcasting and personal communications satellite design on the correlation of fading inside buildings. Fades were measured with 5 cm spatial separation and every 0.2 percent of the frequency. Median fades ranged from 10 to 20 dB in woodframe houses with metal roofs and walls without and with an aluminum heat shield, respectively. The median decorrelation distance was from 0.5 to 1.1. m and was independent of frequency. The attenuation into the buildings increased only moderately with frequency in most of the buildings with a median slope of about 1 to 3 db/GHz, but increased fastest in the least attenuating building with a slope of 5 dB/GHz. The median decorrelation bandwidth ranged from 1.2 to 3.8 percent of frequency in five of the buildings, and was largest in the least attenuating building, with 20.2 percent of frequency.

  8. Dynamic nuclear polarization at 700 MHz/460 GHz.

    PubMed

    Barnes, Alexander B; Markhasin, Evgeny; Daviso, Eugenio; Michaelis, Vladimir K; Nanni, Emilio A; Jawla, Sudheer K; Mena, Elijah L; DeRocher, Ronald; Thakkar, Ajay; Woskov, Paul P; Herzfeld, Judith; Temkin, Richard J; Griffin, Robert G

    2012-11-01

    We describe the design and implementation of the instrumentation required to perform DNP-NMR at higher field strengths than previously demonstrated, and report the first magic-angle spinning (MAS) DNP-NMR experiments performed at (1)H/e(-) frequencies of 700 MHz/460 GHz. The extension of DNP-NMR to 16.4 T has required the development of probe technology, cryogenics, gyrotrons, and microwave transmission lines. The probe contains a 460 GHz microwave channel, with corrugated waveguide, tapers, and miter-bends that couple microwave power to the sample. Experimental efficiency is increased by a cryogenic exchange system for 3.2 mm rotors within the 89 mm bore. Sample temperatures ≤85 K, resulting in improved DNP enhancements, are achieved by a novel heat exchanger design, stainless steel and brass vacuum jacketed transfer lines, and a bronze probe dewar. In addition, the heat exchanger is preceded with a nitrogen drying and generation system in series with a pre-cooling refrigerator. This reduces liquid nitrogen usage from >700 l per day to <200 l per day and allows for continuous (>7 days) cryogenic spinning without detrimental frost or ice formation. Initial enhancements, ε=-40, and a strong microwave power dependence suggests the possibility for considerable improvement. Finally, two-dimensional spectra of a model system demonstrate that the higher field provides excellent resolution, even in a glassy, cryoprotecting matrix.

  9. Pulsar polarization: weak sources and emission features at 430 MHz

    SciTech Connect

    Rankin, J.M.; Benson, J.M.

    1981-03-01

    We have measured the Stokes parameters of the average profiles of 31 pulsars at 430 MHz. The three pulsars in our sample with interpulse emission (0823+26, 0950+08, and 1929+10) have measurable linear polarization angles. In particular, PSR 0950+08 exhibits a polarization angle signature that rotates smoothly and continuously through 180/sup 0/ across the interpulse-- main pulse waveform. Of the remaining 28 pulsars, 17 have simple profile shapes and 11 have double or complex profiles. The highest levels of linear polarization (60% to 83%) are found in four pulsars with simple profiles. The remaining 24 objects have linear polarizations more or less evenly distributed between 0% and 45%, and show no correlation of linear emission with pulse shape. Switching between dominant linear emission modes is revealed through sudden 90/sup 0/ shifts in the linear polarization angle, usually at the leading and/or trailing edges of the profiles. Interference between orthogonal emission states apparently causes much of the linear depolarization in this sample of objects. We further measure levels of circular polarization between 0% and 25% in these objects. Approximately one-half of the objects have circular levels less than approx.10%. The circular polarization fractions appear to be independent of both pulse shape and linear polarization level.

  10. Electrical discontinuity of tissue substitute models at 27. 12 MHz

    SciTech Connect

    Lehmann, J.F.; McDougall, J.A.; Guy, A.W.; Chou, C.K.; Esselman, P.C.; Warren, C.G.

    1983-01-01

    Tissue-substitute models consisting of layers of synthetic, electrically equivalent subcutaneous fat, muscle, and bone shaped in conformation with the normal anatomy are used for rapid determination of distribution of temperature and specific absorption rate throughout the tissues when exposed to electromagnetic radiation. The surfaces of the bisected models are approximated during a short exposure period, then separated and scanned with a thermograph. A method was developed to eliminate the electrical discontinuity at the bisected surfaces while allowing separation and subsequent thermographic scanning. A thin layer of silk screen wetted with propylene glycol saturated with sodium chloride was used at the fat interface and a 0.9% sodium chloride solution was used to wet the screen at the muscle interface to eliminate electrical discontinuity during exposure to 27.12-MHz diathermy. Tests showed that in the presence of an electrical discontinuity the heating pattern was grossly distorted. With the method used, the electrical discontinuity is minimized and the subsequent thermographic scanning reveals that the heating pattern is equivalent to that of an intact model.

  11. 50 MHz dual-mode buck DC—DC converter

    NASA Astrophysics Data System (ADS)

    Zhang, Zhang; Xing, Wang; Wencheng, Yu; Ye, Tan; Yizhong, Yang; Guangjun, Xie

    2016-08-01

    A 50 MHz 1.8/0.9 V dual-mode buck DC—DC converter is proposed in this paper. A dual-mode control for high-frequency DC—DC converter is presented to enhance the conversion efficiency of light-load in this paper. A novel zero-crossing detector is proposed to shut down synchronous rectification transistor NMOS when the inductor crosses zero, which can decrease the power loss caused by reverse current and the trip point is adjusted by regulating IBIAS (BIAS current). A new logic control for pulse-skipping modulation loop is also presented in this paper, which has advantages of simple structure and low power loss. The proposed converter is realized in SMIC 0.18 μm 1-poly 6-metal mixed signal CMOS process. With switching loss, conduction loss and reverse current related loss optimized, an efficiency of 57% is maintained at 10 mA, and a peak efficiency of 71% is measured at nominal operating conditions with a voltage conversion of 1.8 to 0.9 V. Project supported by the National Natural Science Foundation of China (Nos. 61404043, 61401137), the Key Laboratory of Infrared Imaging Material and Detectors, Shanghai Institute of Technical Physics, CAS (Nos. IIMDKFJJ-13-06, IIMDKFJJ-14-03), and the Fundamental Research Funds for the Central University (No. 2015HGZX0026).

  12. 4 Kelvin Cryogenic Probe for 500 MHz NMR

    NASA Astrophysics Data System (ADS)

    Yoshimoto, F.; Takahashi, M.; Horiuchi, T.; Hobo, F.; Inoue, K.; Miki, T.; Hamada, M.; Okamura, T.; Yokoyama, S.; Maeda, H.

    2006-04-01

    This paper describes the development of a 4 K cryogenic probe for 500 MHz Nuclear Magnetic Resonance (NMR) analyses. As thermal noise is proportional to the square root of the RF coil temperature, sensitivity of a 4 K probe is expected to be double that of conventional 25 K probes. The 4 K probe apparatus consists of a closed-cycle cooling system, a 5 m long helium transfer line and the NMR probe itself. The cooling system produces cold helium mist with a Gifford-McMahon/Joule-Thomson (GM/JT) cryocooler. The helium mist traverses the transfer line and then cools the RF coil. An acceptable power input of 3.6 W for the NMR pulse sequence was demonstrated, which was more than the time-averaged heat input, 2 W, generated by a multi-dimensional NMR pulse sequence. The basic NMR sensitivity of the cryogenic probe remains insufficient at present, but increasing B1xy (the field component in the xy plane generated by unit current of the RF coil) and decreasing the noise temperature of the preamplifier are promising approaches for achieving higher sensitivity in the future.

  13. Adaptive optics optical coherence tomography at 1 MHz.

    PubMed

    Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Miller, Donald T

    2014-12-01

    Image acquisition speed of optical coherence tomography (OCT) remains a fundamental barrier that limits its scientific and clinical utility. Here we demonstrate a novel multi-camera adaptive optics (AO-)OCT system for ophthalmologic use that operates at 1 million A-lines/s at a wavelength of 790 nm with 5.3 μm axial resolution in retinal tissue. Central to the spectral-domain design is a novel detection channel based on four high-speed spectrometers that receive light sequentially from a 1 × 4 optical switch assembly. Absence of moving parts enables ultra-fast (50ns) and precise switching with low insertion loss (-0.18 dB per channel). This manner of control makes use of all available light in the detection channel and avoids camera dead-time, both critical for imaging at high speeds. Additional benefit in signal-to-noise accrues from the larger numerical aperture afforded by the use of AO and yields retinal images of comparable dynamic range to that of clinical OCT. We validated system performance by a series of experiments that included imaging in both model and human eyes. We demonstrated the performance of our MHz AO-OCT system to capture detailed images of individual retinal nerve fiber bundles and cone photoreceptors. This is the fastest ophthalmic OCT system we know of in the 700 to 915 nm spectral band.

  14. 75 FR 9210 - Wireless Telecommunications Bureau Seeks Comment on Petition for Rulemaking Regarding 700 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... COMMISSION Wireless Telecommunications Bureau Seeks Comment on Petition for Rulemaking Regarding 700 MHz Band...: Notice. SUMMARY: The Wireless Telecommunications Bureau seeks comment on a petition for rulemaking asking... Telecommunications Bureau seeks comment on the Petition.\\4\\ \\1\\ 700 MHz Block A Good Faith Purchaser...

  15. 47 CFR 90.801 - 900 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false 900 MHz SMR spectrum subject to competitive bidding. 90.801 Section 90.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Specialized Mobile Radio Service § 90.801 900 MHz SMR spectrum subject to competitive bidding....

  16. 47 CFR 90.801 - 900 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false 900 MHz SMR spectrum subject to competitive bidding. 90.801 Section 90.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Specialized Mobile Radio Service § 90.801 900 MHz SMR spectrum subject to competitive bidding....

  17. 47 CFR 90.801 - 900 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false 900 MHz SMR spectrum subject to competitive bidding. 90.801 Section 90.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Specialized Mobile Radio Service § 90.801 900 MHz SMR spectrum subject to competitive bidding....

  18. 47 CFR 90.801 - 900 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false 900 MHz SMR spectrum subject to competitive bidding. 90.801 Section 90.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Specialized Mobile Radio Service § 90.801 900 MHz SMR spectrum subject to competitive bidding....

  19. 78 FR 42701 - Improving Public Safety Communications in the 800 MHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ... action will allow qualified applicants to gain access to 900 MHz B/ILT spectrum without unnecessary delay, and promote spectrum efficiency, by allowing access to spectrum that may otherwise be unused during... 900 MHz B/ILT spectrum, including the ongoing needs of Sprint Nextel for access to this spectrum...

  20. 47 CFR 90.801 - 900 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false 900 MHz SMR spectrum subject to competitive bidding. 90.801 Section 90.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Specialized Mobile Radio Service § 90.801 900 MHz SMR spectrum subject to competitive bidding....

  1. 78 FR 66298 - Promoting Interoperability in the 700 MHz Commercial Spectrum; Requests for Waiver and Extension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-05

    ...In this document, the Federal Communications Commission (Commission) takes certain steps to implement an industry solution to provide interoperable Long Term Evolution (LTE) in the Lower 700 MHz band to improve choice and quality for consumers of mobile services. The Commission revises its Part 27 rules to modify the technical requirements for the Lower 700 MHz D and E blocks to eliminate......

  2. 47 CFR 80.303 - Watch on 156.800 MHz (Channel 16).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Watch on 156.800 MHz (Channel 16). 80.303... SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Coast Station Safety Watches § 80.303 Watch on 156.800 MHz (Channel 16). (a) During its hours of operation, each coast...

  3. 47 CFR 80.303 - Watch on 156.800 MHz (Channel 16).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Watch on 156.800 MHz (Channel 16). 80.303... SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Coast Station Safety Watches § 80.303 Watch on 156.800 MHz (Channel 16). (a) During its hours of operation, each coast...

  4. 47 CFR 80.303 - Watch on 156.800 MHz (Channel 16).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Watch on 156.800 MHz (Channel 16). 80.303... SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Coast Station Safety Watches § 80.303 Watch on 156.800 MHz (Channel 16). (a) During its hours of operation, each coast...

  5. 47 CFR 80.303 - Watch on 156.800 MHz (Channel 16).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Watch on 156.800 MHz (Channel 16). 80.303... SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Coast Station Safety Watches § 80.303 Watch on 156.800 MHz (Channel 16). (a) During its hours of operation, each coast...

  6. 47 CFR 80.303 - Watch on 156.800 MHz (Channel 16).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Watch on 156.800 MHz (Channel 16). 80.303... SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Coast Station Safety Watches § 80.303 Watch on 156.800 MHz (Channel 16). (a) During its hours of operation, each coast...

  7. 47 CFR 95.627 - MedRadio transmitters in the 401-406 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false MedRadio transmitters in the 401-406 MHz band... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Technical Regulations Technical Standards § 95.627 MedRadio transmitters in the 401-406 MHz band. The following provisions apply only to MedRadio transmitters operating...

  8. 47 CFR 95.627 - MedRadio transmitters in the 401-406 MHz band.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false MedRadio transmitters in the 401-406 MHz band... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Technical Regulations Technical Standards § 95.627 MedRadio transmitters in the 401-406 MHz band. The following provisions apply only to MedRadio transmitters operating...

  9. 47 CFR 95.1402 - Special requirements for 406 MHz PLBs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES PERSONAL RADIO SERVICES Personal Locator Beacons (PLB) § 95.1402 Special requirements for 406 MHz... Personal Locator Beacons (PLBs),” Version 1.1, RTCM Paper 76-2002/SC110-STD, dated June 19, 2002. This RTCM..._regulations/ibr_locations.html. (b) The 406 MHz PLB must contain, as an integral part, a homing...

  10. 47 CFR 95.1402 - Special requirements for 406 MHz PLBs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES PERSONAL RADIO SERVICES Personal Locator Beacons (PLB) § 95.1402 Special requirements for 406 MHz... Personal Locator Beacons (PLBs),” Version 1.1, RTCM Paper 76-2002/SC110-STD, dated June 19, 2002. This RTCM..._regulations/ibr_locations.html. (b) The 406 MHz PLB must contain, as an integral part, a homing...

  11. 47 CFR 95.1402 - Special requirements for 406 MHz PLBs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES PERSONAL RADIO SERVICES Personal Locator Beacons (PLB) § 95.1402 Special requirements for 406 MHz... Personal Locator Beacons (PLBs),” Version 1.1, RTCM Paper 76-2002/SC110-STD, dated June 19, 2002. This RTCM..._regulations/ibr_locations.html. (b) The 406 MHz PLB must contain, as an integral part, a homing...

  12. 47 CFR 27.905 - 1670-1675 MHz service licenses subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false 1670-1675 MHz service licenses subject to competitive bidding. 27.905 Section 27.905 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1670-1675 MHz Band § 27.905...

  13. 47 CFR 27.905 - 1670-1675 MHz service licenses subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false 1670-1675 MHz service licenses subject to competitive bidding. 27.905 Section 27.905 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1670-1675 MHz Band § 27.905...

  14. 47 CFR 27.905 - 1670-1675 MHz service licenses subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false 1670-1675 MHz service licenses subject to competitive bidding. 27.905 Section 27.905 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1670-1675 MHz Band § 27.905...

  15. 47 CFR 27.905 - 1670-1675 MHz service licenses subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false 1670-1675 MHz service licenses subject to competitive bidding. 27.905 Section 27.905 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1670-1675 MHz Band § 27.905...

  16. 47 CFR 27.905 - 1670-1675 MHz service licenses subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false 1670-1675 MHz service licenses subject to competitive bidding. 27.905 Section 27.905 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1670-1675 MHz Band § 27.905...

  17. 47 CFR 27.1301 - Designated entities in the 600 MHz band.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Designated entities in the 600 MHz band. 27.1301 Section 27.1301 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 600 MHz Band § 27.1301 Designated entities in...

  18. 47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... public/private partnership. 27.1308 Section 27.1308 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1308 Organization and structure of the 700 MHz public/private partnership. (a) The Upper...

  19. 47 CFR 90.1408 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... public/private partnership. 90.1408 Section 90.1408 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES 700 MHz Public/Private Partnership § 90.1408 Organization and structure of the 700 MHz public/private partnership. (a) The Upper...

  20. 47 CFR 90.1408 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... public/private partnership. 90.1408 Section 90.1408 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES 700 MHz Public/Private Partnership § 90.1408 Organization and structure of the 700 MHz public/private partnership. (a) The Upper...

  1. 47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... public/private partnership. 27.1308 Section 27.1308 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1308 Organization and structure of the 700 MHz public/private partnership. (a) The Upper...

  2. 47 CFR 22.651 - 470-512 MHz channels for trunked mobile operation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false 470-512 MHz channels for trunked mobile... Operation § 22.651 470-512 MHz channels for trunked mobile operation. The following channels are allocated... areas. All channels have a bandwidth of 20 kHz and are designated by their center frequencies in...

  3. 47 CFR 90.1408 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Commission may require or allow shall have the obligation to build out the Shared Wireless Broadband Network... MHz D Block licensee and the Network Assets Holder and such other related entities as the Commission... Upper 700 MHz D Block licensee, the Network Assets Holder, and related entities as the Commission...

  4. 47 CFR 95.1402 - Special requirements for 406 MHz PLBs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES PERSONAL RADIO SERVICES Personal Locator Beacons (PLB). § 95.1402 Special requirements for 406 MHz... Personal Locator Beacons (PLBs),” Version 1.1, RTCM Paper 76-2002/SC110-STD, dated June 19, 2002. This RTCM..._regulations/ibr_locations.html. (b) The 406 MHz PLB must contain, as an integral part, a homing...

  5. 47 CFR 95.1402 - Special requirements for 406 MHz PLBs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES PERSONAL RADIO SERVICES Personal Locator Beacons (PLB). § 95.1402 Special requirements for 406 MHz... Personal Locator Beacons (PLBs),” Version 1.1, RTCM Paper 76-2002/SC110-STD, dated June 19, 2002. This RTCM..._regulations/ibr_locations.html. (b) The 406 MHz PLB must contain, as an integral part, a homing...

  6. 47 CFR 80.1061 - Special requirements for 406.0-406.1 MHz EPIRB stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... integral part a “homing” beacon operating only on 121.500 MHz that meets all the requirements described in... “homing” beacon must have a continuous duty cycle that may be interrupted during the transmission of the....001, “Specification for COSPAS-SARSAT 406 MHz Distress Beacons,” Issue 3—Revision 4, October 2002,...

  7. 47 CFR 87.199 - Special requirements for 406.0-406.1 MHz ELTs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... contain as an integral part a homing beacon operating only on 121.500 MHz that meets all the requirements... MHz homing beacon must have a continuous duty cycle that may be interrupted during the transmission of... Beacon Type Approval Standard (C/S T.007). Additionally, an independent test facility must certify...

  8. 47 CFR 80.1061 - Special requirements for 406.0-406.1 MHz EPIRB stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... integral part a “homing” beacon operating only on 121.500 MHz that meets all the requirements described in... “homing” beacon must have a continuous duty cycle that may be interrupted during the transmission of the....001, “Specification for COSPAS-SARSAT 406 MHz Distress Beacons,” Issue 3—Revision 4, October 2002,...

  9. 47 CFR 90.804 - Aggregation of 900 MHz SMR licenses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Section 90.804 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.804 Aggregation of 900 MHz SMR licenses. The Commission will license each...

  10. 47 CFR 90.804 - Aggregation of 900 MHz SMR licenses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Section 90.804 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.804 Aggregation of 900 MHz SMR licenses. The Commission will license each...

  11. 47 CFR 90.804 - Aggregation of 900 MHz SMR licenses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Section 90.804 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.804 Aggregation of 900 MHz SMR licenses. The Commission will license each...

  12. 47 CFR 90.804 - Aggregation of 900 MHz SMR licenses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Section 90.804 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.804 Aggregation of 900 MHz SMR licenses. The Commission will license each...

  13. 47 CFR 90.804 - Aggregation of 900 MHz SMR licenses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Section 90.804 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.804 Aggregation of 900 MHz SMR licenses. The Commission will license each...

  14. Results of Bare Die Probing for RF Booster Chip at 450, 915, and 2400 MHz

    DTIC Science & Technology

    2010-04-01

    73 iv 3.14 ARL14G24 – BPSK Modulator, PA, Narrowband LNA, and TR Switch...67 ix Figure 73 . The behavior of the gain and NF for the LNA at 450 MHz. .......................................68 Figure 74. Measured...current mirror at 900 MHz. Blue is measured and pink is simulated data points. ...... 73 Figure 79. Layout of cascaded BPSK modulator and PA

  15. 47 CFR 90.279 - Power limitations applicable to the 421-430 MHz band.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... height above mean sea level. Limits of Effective Radiated Power (ERP) Corresponding to Effective Antenna... 47 Telecommunication 5 2014-10-01 2014-10-01 false Power limitations applicable to the 421-430 MHz... Bands § 90.279 Power limitations applicable to the 421-430 MHz band. (a) Base station authorizations...

  16. 47 CFR 90.279 - Power limitations applicable to the 421-430 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... height above mean sea level. Limits of Effective Radiated Power (ERP) Corresponding to Effective Antenna... 47 Telecommunication 5 2013-10-01 2013-10-01 false Power limitations applicable to the 421-430 MHz... Bands § 90.279 Power limitations applicable to the 421-430 MHz band. (a) Base station authorizations...

  17. 47 CFR 90.279 - Power limitations applicable to the 421-430 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... height above mean sea level. Limits of Effective Radiated Power (ERP) Corresponding to Effective Antenna... 47 Telecommunication 5 2011-10-01 2011-10-01 false Power limitations applicable to the 421-430 MHz... Bands § 90.279 Power limitations applicable to the 421-430 MHz band. (a) Base station authorizations...

  18. 47 CFR 90.279 - Power limitations applicable to the 421-430 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... height above mean sea level. Limits of Effective Radiated Power (ERP) Corresponding to Effective Antenna... 47 Telecommunication 5 2012-10-01 2012-10-01 false Power limitations applicable to the 421-430 MHz... Bands § 90.279 Power limitations applicable to the 421-430 MHz band. (a) Base station authorizations...

  19. Implementation and evaluation of the new wind algorithm in NASA's 50 MHz doppler radar wind profiler

    NASA Technical Reports Server (NTRS)

    Taylor, Gregory E.; Manobianco, John T.; Schumann, Robin S.; Wheeler, Mark M.; Yersavich, Ann M.

    1993-01-01

    The purpose of this report is to document the Applied Meteorology Unit's implementation and evaluation of the wind algorithm developed by Marshall Space Flight Center (MSFC) on the data analysis processor (DAP) of NASA's 50 MHz doppler radar wind profiler (DRWP). The report also includes a summary of the 50 MHz DRWP characteristics and performance and a proposed concept of operations for the DRWP.

  20. 47 CFR 90.1319 - Policies governing the use of the 3650-3700 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Wireless Broadband Services in the 3650-3700 MHz Band § 90.1319 Policies governing the use of the 3650-3700 MHz band. (a) Channels in this band... identifying the locations of registered stations will be available at http://wireless.fcc.gov/uls....

  1. Evaluating the More Suitable ISM Frequency Band for IoT-Based Smart Grids: A Quantitative Study of 915 MHz vs. 2400 MHz.

    PubMed

    Sandoval, Ruben M; Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Garcia-Haro, Joan

    2016-12-31

    IoT has begun to be employed pervasively in industrial environments and critical infrastructures thanks to its positive impact on performance and efficiency. Among these environments, the Smart Grid (SG) excels as the perfect host for this technology, mainly due to its potential to become the motor of the rest of electrically-dependent infrastructures. To make this SG-oriented IoT cost-effective, most deployments employ unlicensed ISM bands, specifically the 2400 MHz one, due to its extended communication bandwidth in comparison with lower bands. This band has been extensively used for years by Wireless Sensor Networks (WSN) and Mobile Ad-hoc Networks (MANET), from which the IoT technologically inherits. However, this work questions and evaluates the suitability of such a "default" communication band in SG environments, compared with the 915 MHz ISM band. A comprehensive quantitative comparison of these bands has been accomplished in terms of: power consumption, average network delay, and packet reception rate. To allow such a study, a dual-band propagation model specifically designed for the SG has been derived, tested, and incorporated into the well-known TOSSIM simulator. Simulation results reveal that only in the absence of other 2400 MHz interfering devices (such as WiFi or Bluetooth) or in small networks, is the 2400 MHz band the best option. In any other case, SG-oriented IoT quantitatively perform better if operating in the 915 MHz band.

  2. Evaluating the More Suitable ISM Frequency Band for IoT-Based Smart Grids: A Quantitative Study of 915 MHz vs. 2400 MHz

    PubMed Central

    Sandoval, Ruben M.; Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Garcia-Haro, Joan

    2016-01-01

    IoT has begun to be employed pervasively in industrial environments and critical infrastructures thanks to its positive impact on performance and efficiency. Among these environments, the Smart Grid (SG) excels as the perfect host for this technology, mainly due to its potential to become the motor of the rest of electrically-dependent infrastructures. To make this SG-oriented IoT cost-effective, most deployments employ unlicensed ISM bands, specifically the 2400 MHz one, due to its extended communication bandwidth in comparison with lower bands. This band has been extensively used for years by Wireless Sensor Networks (WSN) and Mobile Ad-hoc Networks (MANET), from which the IoT technologically inherits. However, this work questions and evaluates the suitability of such a “default” communication band in SG environments, compared with the 915 MHz ISM band. A comprehensive quantitative comparison of these bands has been accomplished in terms of: power consumption, average network delay, and packet reception rate. To allow such a study, a dual-band propagation model specifically designed for the SG has been derived, tested, and incorporated into the well-known TOSSIM simulator. Simulation results reveal that only in the absence of other 2400 MHz interfering devices (such as WiFi or Bluetooth) or in small networks, is the 2400 MHz band the best option. In any other case, SG-oriented IoT quantitatively perform better if operating in the 915 MHz band. PMID:28042863

  3. R&D ERL: 5 Cell 704 MHz SRF Cavity

    SciTech Connect

    Burrill, A.

    2010-01-01

    One of the key components for the superconducting RF Energy Recovery Linac, (ERL) under development in the Collider Accelerator Department at Brookhaven National Laboratory, is the Linac cavity and cryomodule. The cavity is a 5 cell accelerating cavity designed to operate at 703.75 MHz, and to accelerate 2 MeV electrons from the photoinjector up to 15-20 MeV, allow them to make a single pass around the ERL loop and then decelerate them back down to 2 MeV prior to sending them to the beam dump. This cavity was designed by Rama Calaga and Ilan Ben-Zvi at BNL and fabricated by Advanced Energy Systems in Medford, NY. The cavity was then delivered to Thomas Jefferson Laboratory in VA for chemical processing, testing and assembly of the hermetic string assembly suitable for shipment back to BNL. Once at BNL it was built into a complete cryomodule, installed in the ERL test facility and commissioned. This paper will review the key components of the cavity and cryomodule and discuss the present status of the cryomodule commissioning. The BNL 5 cell accelerating cavity has been designed for use in our high average current Energy Recovery Linac, a proof of principle machine to demonstrate key components necessary for the future upgrades to RHIC as well as applications for future ampere class high current, high brightness ERL programs. The cavity has been tested at greater than 20 MV/m with a Q{sub 0} of 1e{sup 10}, meeting the design specifications for use at full energy in the ERL. This paper will review the cavity design and specifications as well as the RF measurements that have been made both in the VTA at Jefferson Lab as well as during the commissioning in the ERL test cave at BNL. Finally the future plan for cavity testing and measurements prior to its use in ERL operations will be reviewed. The general physics parameters for the cavity can be found in table 1, and the reader is referred to Rama Calaga's Thesis for a much more detailed review of the cavity geometry

  4. 75 FR 6316 - Revisions to Rules Authorizing the Operation of Low Power Auxiliary Stations in the 698-806 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... 698-806 MHz Band; Public Interest Spectrum Coalition, Petition for Rulemaking Regarding Low Power... Stations in the 698-806 MHz Band; Public Interest Spectrum Coalition, Petition for Rulemaking Regarding...

  5. 47 CFR 27.1325 - Resolution of disputes after grant of the upper 700 MHz D block license.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 700 MHz D block license. 27.1325 Section 27.1325 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private... Security Bureau and the Wireless Telecommunications Bureau are delegated joint responsibility...

  6. 47 CFR 90.1432 - Conditions for waiver to allow limited and temporary wideband operations in the 700 MHz public...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... temporary wideband operations in the 700 MHz public safety spectrum. 90.1432 Section 90.1432... and temporary wideband operations in the 700 MHz public safety spectrum. (a) Wideband operations in the 700 MHz Public Safety spectrum. Wideband operations are prohibited in the public safety...

  7. 47 CFR 90.1432 - Conditions for waiver to allow limited and temporary wideband operations in the 700 MHz public...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... temporary wideband operations in the 700 MHz public safety spectrum. 90.1432 Section 90.1432... and temporary wideband operations in the 700 MHz public safety spectrum. (a) Wideband operations in the 700 MHz Public Safety spectrum. Wideband operations are prohibited in the public safety...

  8. 75 FR 3639 - Revisions to Rules Authorizing the Operation of Low Power Auxiliary Stations in the 698-806 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-22

    ... 698-806 MHz Band; Public Interest Spectrum Coalition, Petition for Rulemaking Regarding Low Power... Power Auxiliary Stations in the 698-806 MHz Band; Public Interest Spectrum Coalition, Petition for... Operation of Low Power Auxiliary Stations in the 698-806 MHz Band; Public Interest Spectrum...

  9. 47 CFR 90.1432 - Conditions for waiver to allow limited and temporary wideband operations in the 700 MHz public...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... temporary wideband operations in the 700 MHz public safety spectrum. 90.1432 Section 90.1432... and temporary wideband operations in the 700 MHz public safety spectrum. (a) Wideband operations in the 700 MHz Public Safety spectrum. Wideband operations are prohibited in the public safety...

  10. 75 FR 9113 - Revisions to Rules Authorizing the Operation of Low Power Auxiliary Stations in the 698-806 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... Stations in the 698-806 MHz Band; Public Interest Spectrum Coalition, Petition for Rulemaking Regarding Low... Authorizing the Operation of Low Power Auxiliary Stations in the 698-806 MHz Band; Public Interest Spectrum... Auxiliary Stations in the 698-806 MHz Band; Public Interest Spectrum Coalition, Petition for...

  11. 47 CFR 27.1325 - Resolution of disputes after grant of the upper 700 MHz D block license.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1325 Resolution of disputes after grant of the upper 700 MHz D block license. (a) The Upper 700 MHz D Block licensee, the Operating Company, the Network Assets Holder and the Public...

  12. 75 FR 3622 - Revisions to Rules Authorizing the Operation of Low Power Auxiliary Stations in the 698-806 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-22

    ...In this Report and Order, the Commission establishes a deadline for wireless microphones and other low power auxiliary stations to cease operation in the 700 MHz Band. The Commission also adopts an early clearing mechanism by which 700 MHz public safety and commercial licensees can provide notice that they are initiating operations in the 700 MHz Band. In addition, the Commission prohibits the......

  13. 78 FR 70499 - Private Land Mobile Radio Stations Below 800 MHz

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... No. 07-100; FCC 13-52] Private Land Mobile Radio Stations Below 800 MHz AGENCY: Final rule... changes to 47 CFR 90.425 of the Commission's rules to allow Private Land Mobile Radio (PLMR) licensees...

  14. Angular source size measurements and interstellar scattering at 103 MHz using interplanetary scintillation

    NASA Astrophysics Data System (ADS)

    Janardhan, P.; Alurkar, S. K.

    1993-03-01

    Data obtained between 1984 and 1987, using a radio telescope (RT) with a 10,000 sq m dipole array operating at 103 MHz, was used to determine the angular diameters of fourteen strongly scintillating radio sources. The method used exploited the technique of interplanetary scintillation (IPS), wherein the systematic variation of scintillation index with solar elongation was used as a unique indicator of the source size. The method has been used before but these are the first measurements at 103 MHz. These values were then used in conjunction with similar available measurements at 151.5 MHz to determine the contribution of interstellar scattering (ISS) to source broadening at 103 MHz. Enhanced scattering due to ISS in the plane of the galaxy has been confirmed.

  15. Higher Order Model Power Calculation of the 56 MHz SRF Cavity

    SciTech Connect

    Choi,E.

    2008-08-01

    In this report, the HOM power dissipated to the load in the 56 MHz RF cavity is calculated. The HOM frequencies and Q factors with the inserted HOM damper are obtained from the simulations by MWS and SLAC codes.

  16. 47 CFR 95.803 - 218-219MHz Service description.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... its administrative apparatus, its response transmitter units (RTUs), and one or more cell transmitter... § 95.811. (c) Each 218-219 MHz Service system service area is one of the cellular system service...

  17. Acoustic properties of bovine cancellous bone from 0.5 to 1.5 MHz

    NASA Astrophysics Data System (ADS)

    Lee, Kang Il; Roh, Heui-Seol; Yoon, S. W.

    2002-05-01

    Most previous studies using ultrasound for the diagnosis of osteoporosis have employed ultrasound in the frequency range from 0.2 to 1 MHz. Acoustic properties of 14 defatted bovine cancellous bone specimens were investigated in vitro. Speed of sound (SOS) and broadband ultrasonic attenuation (BUA) were measured using two matched pairs of transducers with the center frequencies of 1 and 2.25 MHz, respectively, in order to cover a broad frequency range from 0.5 to 1.5 MHz. In this frequency range, SOS and BUA show significant linear positive correlations with apparent bone density. These results suggest that the frequency range from 0.5 to 1.5 MHz may also be useful in the diagnosis of osteoporosis. [Work supported by BK21 Program, KRF (KRF-2000-015-DP0718), and KOSEF (KOSEF-2000-0238-100) in Korea.] a)For (Biomedical Ultrasound/Bioresponse to Vibration) Best Student Paper Award.

  18. DSN 64-meter antenna L-band (1668-MHz) microwave system performance overview

    NASA Technical Reports Server (NTRS)

    Withington, J.

    1988-01-01

    In 1985, L-band (1668 MHz) receive-only feed systems were installed on the three Deep Space Network 64 meter antennas to provide tracking support for two non-NASA spacecraft. The specifications, design approach, and operational test results are presented. The L-band microwave system met all of its tracking goals and is currently being upgraded to include a C-band (5000 MHz) uplink.

  19. Initial Approaches to Mitigating the Impacts of the AWS-3 Auction (1755-1780 MHz)

    DTIC Science & Technology

    2015-05-13

    AWS-3, Aeronautical Mobile Telemetry, LTE-A, Transition Plan, Transmitters, Receivers, Antenna Systems, Bandwidth Efficient Modulation, Spectrum 16... antenna systems will be modified to desensitize them to commercial operations in the 1755-1780 MHz and 2155-2180 MHz bands • Better filters and LNA’s...Or TBD Technologies identified in upcoming studies • Telemetry antenna systems will be modified to provide bi- directional capability to control

  20. Results from a MHz gravitational wave search using the Fermilab Holometer

    NASA Astrophysics Data System (ADS)

    Kamai, Brittany; Holometer Collaboration Collaboration

    2017-01-01

    The Fermilab Holometer, two nested 40 meter Michelson interferometers, has extended the accessible gravitational wave frequency range from kHz to a broad range of MHz frequencies. I will present results from a 130-hr campaign that measured the energy density of gravitational waves in the MHz band. Additionally, this dataset was used to place constraints on the abundance of primordial black hole binaries.

  1. 47 CFR 90.617 - Frequencies in the 809.750-824/854.750-869 MHz, and 896-901/935-940 MHz bands available for...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing Licensing and Use of... channels. These frequencies are available in non-border areas. Specialized Mobile Radio Systems will not be... part but exclude Special Mobilized Radio Systems as defined in § 90.603(c). 800 MHz high...

  2. 47 CFR 90.259 - Assignment and use of frequencies in the bands 216-220 MHz and 1427-1432 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... power is 2 watts. The maximum antenna height above average terrain (HAAT) is 152 m (500 feet). (5) In... of Charles City, Chesterfield, Dinwiddie, Goochland, Hanover, Henrico, Isle of Wight, James City, New... locations, secondary operations are performed in the 1427-1429.5 MHz band. The maximum power is 1 watt...

  3. 47 CFR 90.259 - Assignment and use of frequencies in the bands 216-220 MHz and 1427-1432 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... power is 2 watts. The maximum antenna height above average terrain (HAAT) is 152 m (500 feet). (5) In... of Charles City, Chesterfield, Dinwiddie, Goochland, Hanover, Henrico, Isle of Wight, James City, New... locations, secondary operations are performed in the 1427-1429.5 MHz band. The maximum power is 1 watt...

  4. 47 CFR 90.259 - Assignment and use of frequencies in the bands 216-220 MHz and 1427-1432 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... power is 2 watts. The maximum antenna height above average terrain (HAAT) is 152 m (500 feet). (5) In... of Charles City, Chesterfield, Dinwiddie, Goochland, Hanover, Henrico, Isle of Wight, James City, New... locations, secondary operations are performed in the 1427-1429.5 MHz band. The maximum power is 1 watt...

  5. 47 CFR 90.259 - Assignment and use of frequencies in the bands 216-220 MHz and 1427-1432 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... power is 2 watts. The maximum antenna height above average terrain (HAAT) is 152 m (500 feet). (5) In... of Charles City, Chesterfield, Dinwiddie, Goochland, Hanover, Henrico, Isle of Wight, James City, New... locations, secondary operations are performed in the 1427-1429.5 MHz band. The maximum power is 1 watt...

  6. 47 CFR 90.259 - Assignment and use of frequencies in the bands 216-220 MHz and 1427-1432 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... power is 2 watts. The maximum antenna height above average terrain (HAAT) is 152 m (500 feet). (5) In... of Charles City, Chesterfield, Dinwiddie, Goochland, Hanover, Henrico, Isle of Wight, James City, New... locations, secondary operations are performed in the 1427-1429.5 MHz band. The maximum power is 1 watt...

  7. OBSERVATIONS OF CRAB GIANT PULSES IN 20-84 MHz USING LWA1

    SciTech Connect

    Ellingson, S. W.; Wolfe, C. N.; Clarke, T. E.; Hicks, B. C.; Wilson, T. L.; Craig, J.; Taylor, G. B.; Lazio, T. J. W.

    2013-05-10

    We report the detection and observed characteristics of giant pulses from the Crab Nebula pulsar (B0531+21) in four frequency bands covering 20-84 MHz using the recently completed Long Wavelength Array Station 1 (LWA1) radio telescope. In 10 hr of observations distributed over a 72 day period in fall of 2012, 33 giant pulses having peak flux densities between 400 Jy and 2000 Jy were detected. Twenty-two of these pulses were detected simultaneously in channels of 16 MHz bandwidth centered at 44 MHz, 60 MHz, and 76 MHz, including one pulse which was also detected in a channel centered at 28 MHz. We quantify statistics of pulse amplitude and pulse shape characteristics, including pulse broadening. Amplitude statistics are consistent with expectations based on extrapolations from previous work at higher and lower frequencies. Pulse broadening is found to be relatively high, but not significantly greater than expected. We present procedures that have been found to be effective for observing giant pulses in this frequency range.

  8. Increasing output power of an 850 MHz tetrode with a floating-deck modulator

    SciTech Connect

    Rees, D.; Friedrichs, C.

    1990-01-01

    Designers of high-power amplifiers generally regard the region above 300 MHz as a domain dominated by velocity-modulated (klystron/TWT) devices. However, as the power requirements diminish, there are attractive alternatives. The high-power 850-MHz requirements of the ground test accelerator (GTA) program can be filled by 1-MW klystrons, but it would be more efficient to use a lower-power device for a 50-kW requirement. To meet the 850-MHz medium-power requirements, Los Alamos National Laboratory is developing an 850-MHz tetrode amplifier. These amplifiers will provide rf power to the momentum compactor and bunch rotator cavities of the GTA. Available tubes provide only a limited safety margin for a low-risk design at the power levels and duty factor required for GTA cavities. At 850 MHz, the output power capability of available tubes is reduced because of transit time effects and limited anode voltage holdoff. Pulsing the anode of the output tetrode amplifier will allow higher output power with minimum design risk. A floating-deck modulator acts as a high-voltage/high-current switch, so voltage is applied to the anode of the gridded tube only during the rf pulse. The anode voltage holdoff capability of the tube is substantially enhanced by operating in this mode. This paper will describe the design of the floating deck modulator and its impact on the design risk of the 850-MHz tetrode amplifier.

  9. Pilot Search for 54-MHz Maser Emission from Interstellar Hydroxyl Using LOFAR

    NASA Astrophysics Data System (ADS)

    Hoffman, Ian M.; Heald, G.; Oonk, R.; McKean, J.; Mol, J.; Hessels, J.; Toribio, C.; LOFAR Collaboration

    2014-01-01

    We present the results of the most sensitive search to date for the two 54-MHz spectral lines of the hydroxyl (OH) molecule. These are the preliminary results of a larger, planned observational campaign. The splitting of the rotational ground state of the hydroxyl molecule gives rise to the four familiar 1.7-GHz transitions by which OH is known in the interstellar medium. There are also two magnetic-dipole transitions among these states at frequencies of 53.2 MHz and 55.1 MHz. These 54-MHz transitions have never been detected astronomically. Because of the relative weakness of the magnetic-dipole emission process, it is expected that only maser emission will generate a detectable 54-MHz signal. Two previous searches have been conducted by other authors with other instruments toward Galactic sources of known 1720-MHz OH maser emission: three sources were searched at 55.1 MHz and two other sources were searched at 53.2 MHz, resulting in upper limits of approximately 30 Jy for spectral channels of 2 km/s in width. In preparation for our future observational campaign that will apply the unprecedented sensitivity of LOFAR to the search for 54-MHz OH emission, we conducted a pilot project using six hours of Commissioning Time. These observations employed 21 48-element stations and produced a spectral resolution of approximately 0.5 km/s for both the 53.2- and 55.1-MHz lines. This spectral resolution is a considerable improvement over previous searches since it is suitable both for resolving the characteristically narrow width of maser lines and for identifying radiofrequency interference. In our pilot observations, no emission was detected at either frequency with an upper limit of approximately 3 Jy. We observed the Galactic sources W75N and W3(OH), neither of which have been searched previously at either frequency. We discuss the astrophysical implications of these sensitive non-detections. LOFAR, the Low Frequency Array designed and constructed by ASTRON, has

  10. Microwave ablation using 915-MHz and 2.45-GHz systems: what are the differences?

    PubMed Central

    Simo, Kerri A; Tsirline, Victor B; Sindram, David; McMillan, Matthew T; Thompson, Kyle J; Swan, Ryan Z; McKillop, Iain H; Martinie, John B; Iannitti, David A

    2013-01-01

    Objectives This study was conducted to evaluate differences between 915-MHz and 2.45-GHz microwave ablation (MWA) systems in the ablation of hepatic tumours. Methods A retrospective analysis of patients undergoing hepatic tumour MWA utilizing two different systems over a 10-month period was carried out. Results Data for a total of 48 patients with a mean age of 58 ± 1.24 years were analysed. A total of 124 tumours were ablated; 72 tumours were ablated with a 915-MHz system and 52 with a 2.45-GHz system. Mean tumour diameters were 1.7 ± 0.1 cm in the 915-MHz group and 2.5 ± 0.2 cm in the 2.45-GHz group (P < 0.01). Mean ablation time per burn was 8.1 ± 0.3 min in the 915-MHz group and 4.0 ± 0.1 min in the 2.45-GHz group (P < 0.01). The mean number of burns per lesion was 2.0 ± 0.1 in the 915-MHz group and 1.7 ± 0.1 in the 2.45-GHz group (P < 0.05). The mean ablation time per lesion was 9.7 ± 0.7 min in the 915-MHz group, and 6.6 ± 0.6 min in the 2.45-GHz group (P < 0.01). The 2.45-GHz system demonstrated a better correlation between ablation time and tumour size (r2 = 0.6222) than the 915-MHz system; (r2 = 0.0696). Mean total energy applied per lesion, and energy applied per cm, were greater with the 915-MHz system (P < 0.05 and P < 0.01, respectively). Total energy applied per lesion was similarly correlated for the 2.45-GHz (r2 = 0.6263) and 915-MHz (r2 = 0.7012) systems. Mean total energy applied per cm/min was greater with the 2.45-GHz system (P < 0.05). Conclusions Both 915-MHz and 2.45-GHz MWA systems achieve reproducible hepatic tumour ablation. The 2.45-GHz system achieves equivalent, but more predictable and faster ablations using a single antenna system. PMID:23490330

  11. Developments and directions in 200 MHz very high power RF at LAMPF

    SciTech Connect

    Cliff, R.; Bush, E.D.; DeHaven, R.A.; Harris, H.W.; Parsons, M.

    1991-01-01

    The Los Alamos Meson Physics Facility (LAMPF), is a linear particle accelerator a half-mile long. It produces an 800 million electron- volt hydrogen-ion beam at an average current of more than one milliamp. The first RF section of the accelerator consists of four Alvarez drift-tube structures. Each of these structures is excited by an amplifier module at a frequency of 201.25 MHz. These amplifiers operate at a duty of 13 percent or more and at peak pulsed power levels of about 2.5 million watts. The second RF accelerator section consists of forty-four side-coupled-cavity structures. Each of these is excited by an amplifier module at a frequency of 805 MHz. These amplifiers operate at a duty of up to 12 percent and at peak pulsed power levels of about 1.2 million watts. The relatively high average beam current in the accelerator places a heavy demand upon components in the RF systems. The 201-MHz modules have always required a large share of maintenance efforts. In recent years, the four 201.25 MHz modules have been responsible for more than twice as much accelerator down-time as have the forty-four 805 MHz modules. This paper reviews recent, ongoing, and planned improvements in the 201-MHz systems. The Burle Industries 7835 super power triode is used in the final power amplifiers of each of the 201-MHz modules. This tube has been modified for operation at LAMPF by the addition of Penning ion vacuum pumps.'' This has enabled more effective tube conditioning and restarting. A calorimetry system of high accuracy is in development to monitor tube plate-power dissipation.

  12. Lightning electromagnetic radiation field spectra in the interval from 0. 2 to 20 MHz

    SciTech Connect

    Willett, J.C. ); Bailey, J.C. ); Leteinturier, C. ); Krider, E.P. )

    1990-11-20

    Average energy spectral densities are presented for the fast transitions in most of the components that produce large radiation field impulses from cloud-to-ground lightning; first and subsequent return strokes; stepped, dart-stepped, and 'chaotic' leaders; and 'characteristic' cloud pulses. A disagreement in the previous literature about the spectral energy radiated by return strokes at high frequencies is noted and explained. The authors show that the spectral amplitudes are not seriously distorted by propagation over less than 35 km of seawater, although as much as 45 km of such propagation does appear to produce significant attenuation above about 10 MHz. First and subsequent return strokes produce identical spectra between 0.2 and 20 MHz. The spectra of stepped and dart-stepped leader steps are nearly identical and are very similar to that of characteristic pulses. The spectra of leader steps also match return stroke spectra above 2-3 MHz after the former are increased by about 7 dB. The shapes of individual spectra do not depend on their amplitude, so the shapes of the average spectra are probably not distorted by the trigger thresholds used in the data acquisition. Return strokes are the strongest sources of radiation from cloud-to-ground lightning in the 0.2- to 20-MHz frequency range, although certain intracloud processes are stronger radiators above 8 MHz.

  13. Dielectric spectroscopy of fresh fruit and vegetable tissues from 10 to 1800 MHz.

    PubMed

    Nelson, Stuart O

    2005-01-01

    Dielectric spectroscopy data from measurements on tissue samples of nine fresh fruits and vegetables were used to study their dielectric behavior over the frequency range from 10 MHz to 1.8 GHz at 5 to 65 degrees C. Dielectric constant and loss-factor data are presented graphically for apple, avocado, banana, cantaloupe, carrot, cucumber, grape, orange, and potato, showing dielectric constants ranging from values of several hundred at 10 MHz to less than 100 at 1.8 GHz and loss factors on the order of one thousand at 10 MHz to less than 20 at 1.8 GHz. The dielectric loss factor increased consistently with increasing temperature at frequencies below 1 GHz. The dielectric constant increased with temperature at lower frequencies, but it decreased with temperature at the higher frequencies. This reversal of the sign of the temperature coefficient occurred at some point in the frequency range between 20 and 120 MHz where the temperature dependence of the dielectric constant was zero. At frequencies below this point, ionic conduction dominates the dielectric behavior, but above that point dipolar relaxation appears to control the behavior. Multiple linear regression provided equations for calculation of the loss factor in the frequency range from 10 to 300 MHz at temperatures from 5 to 65 degrees C. The data provide new information useful in understanding dielectric heating behavior and evaluating dielectric properties of such agricultural products for quality sensing applications.

  14. NEW 145 MHz SOURCE MEASUREMENTS BY PAPER IN THE SOUTHERN SKY

    SciTech Connect

    Jacobs, Daniel C.; Aguirre, James E.; Moore, David F.; Parsons, Aaron R.; Pober, Jonathan C.; Bradley, Richard F.; Parashare, Chaitali R.; Carilli, Chris L.; Gugliucci, Nicole E.; Manley, Jason R.; Van der Merwe, Carel

    2011-06-20

    We present observations from the Precision Array for Probing the Epoch of Reionization (PAPER) in South Africa, observed in 2010 May and September. Using two nights of drift scanning with PAPER's 60{sup 0} FWHM beam we have made a map covering the entire sky below +10{sup 0} declination with an effective center frequency of 145 MHz, a 70 MHz bandwidth, and a resolution of 26'. A 4800 deg{sup 2} region of this large map with the lowest Galactic emission reaches an rms of 0.7 Jy. We establish an absolute flux scale using sources from the 160 MHz Culgoora catalog. Using the 408 MHz Molonglo Reference Catalog (MRC) as a finding survey, we identify counterparts to 480 sources in our maps and compare our fluxes to the MRC and to 332 sources in the Culgoora catalog. For both catalogs, the ratio of PAPER to catalog flux averages to 1, with a standard deviation of 50%. This measured variation is consistent with comparisons between independent catalogs observed at different bands. The PAPER data represent new 145 MHz flux measurements for a large number of sources in the band expected to encompass cosmic reionization and represents a significant step toward establishing a model for removing foregrounds to the reionization signal.

  15. 27.12 MHz Radiofrequency Ablation for Benign Cutaneous Lesions

    PubMed Central

    Kim, Dong Hyun; Hyun, Dong Ju; Piquette, Raymonde; Beaumont, Clément; Germain, Lucie; Larouche, Danielle

    2016-01-01

    As surgical and/or ablative modalities, radiofrequency (RF) has been known to produce good clinical outcomes in dermatology. Recently, 27.12 MHz RF has been introduced and has several advantages over conventional 4 or 6 MHz in terms of the precise ablation and lesser pain perception. We aimed to evaluate the clinical efficacy and safety of 27.12 MHz RF for the treatment of benign cutaneous lesions. Twenty female patient subjects were enrolled. Digital photography and a USB microscope camera were used to monitor the clinical results before one session of treatment with 27.12 MHz RF and after 1 and 3 weeks. Treated lesions included telangiectasias, cherry and spider angiomas, skin tags, seborrheic keratoses, lentigo, milium, dilated pore, acne, piercing hole, and one case of neurofibroma. For vascular lesions, clinical results were excellent for 33.3%, good for 44.4%, moderate for 11.1%, and poor for 11.1%. For nonvascular lesions (epidermal lesions and other benign cutaneous lesions), clinical results were excellent for 48.3%, good for 45.2%, moderate for 3.2%, and poor for 3.2%. No serious adverse events were observed. Mild adverse events reported were slight erythema, scale, and crust. The 27.12 MHz RF treatment of benign vascular and nonvascular lesions appears safe and effective after 3 weeks of follow-up. PMID:27127789

  16. Polarization maser observations of late-type stars at OH 1665 and 1667 MHz

    NASA Astrophysics Data System (ADS)

    Gonidakis, I.; Chapman, J. M.; Deacon, R. M.; Green, A. J.

    2014-10-01

    We present full-polarization observations, taken with the Parkes radio telescope, of the OH masers at 1665 and 1667 MHz in 34 evolved stars comprising 25 post-Asymptotic Giant Branch (post-AGB) stars and nine high-mass AGB stars (known as LI sources). The main objectives of the present study were to investigate the OH mainline polarization properties of post-AGB stars and high-mass AGB stars and to determine whether there is an association between polarization properties and evolutionary age. Circular and/or linear polarization was detected from 21 of the 34 observed stars. Linear polarization was detected as often as circular polarization, and was relatively more common in the 1667 MHz line. Circular polarization is stronger at 1665 MHz. The massive AGB stars appear to have the strongest magnetic fields. For the post-AGB stars there is a trend for increasing magnetic field strength at the location of the OH mainline masers with increasing post-AGB age. We infer that changes to the stellar magnetic fields play a significant role in the emergence of non-spherical morphologies in post-AGB stars. Six sources show narrow linearly polarized features at 1667 MHz with no corresponding circular polarization at 1667 MHz, that are interpreted as candidate π-components. In one source, a candidate π-component is identified through a Zeeman triplet.

  17. The effect of chronic exposure to 835.62 MHz FDMA or 847.74 MHz CDMA radiofrequency radiation on the incidence of spontaneous tumors in rats.

    PubMed

    La Regina, Marie; Moros, Eduardo G; Pickard, William F; Straube, William L; Baty, Jack; Roti Roti, Joseph L

    2003-08-01

    This study was designed to determine whether chronic exposure to radiofrequency (RF) radiation from cellular phones increased the incidence of spontaneous tumors in F344 rats. Eighty male and 80 female rats were randomly placed in each of three irradiation groups. The sham group received no irradiation; the Frequency Division Multiple Access (FDMA) group was exposed to 835.62 MHz FDMA RF radiation; and the Code Division Multiple Access (CDMA) group was exposed to 847.74 MHz CDMA RF radiation. Rats were irradiated 4 h per day, 5 days per week over 2 years. The nominal time-averaged specific absorption rate (SAR) in the brain for the irradiated animals was 0.85 +/- 0.34 W/kg (mean +/- SD) per time-averaged watt of antenna power. Antennas were driven with a time-averaged power of 1.50 +/- 0.25 W (range). That is, the nominal time-averaged brain SAR was 1.3 +/- 0.5 W/kg (mean +/- SD). This number was an average from several measurement locations inside the brain, and it takes into account changes in animal weight and head position during irradiation. All major organs were evaluated grossly and histologically. The number of tumors, tumor types and incidence of hyperplasia for each organ were recorded. There were no significant differences among final body weights or survival days for either males or females in any group. No significant differences were found between treated and sham-exposed animals for any tumor in any organ. We conclude that chronic exposure to 835.62 MHz FDMA or 847.74 MHz CDMA RF radiation had no significant effect on the incidence of spontaneous tumors in F344 rats.

  18. Report on BIPM/CIPM key comparison CCAUV.U-K4: absolute calibration of medical hydrophones in the frequency range 0.5 MHz to 20 MHz

    NASA Astrophysics Data System (ADS)

    Rajagopal, S.; Fury, C. R.; Zeqiri, B.; Brandt, M.; Wilkens, V.; Koch, C.; Matsuda, Y.; Yoshioka, M.; Ping, Y.; Yan, Z.; Wenping, B.; Costa-Felix, R. P. B.; Oliveira, E. G.

    2016-01-01

    The key compariosn CCAUV.U-K4 involved measurement of end-of-cable loaded sensitivity in units of volts/pascal of two travelling standards, 1 mm element diamater medical hydrophones at medical ultrasound frequencies. This is a repetition of key comparison CCAUV.U-K2 but the scope has been extended upwards to 20 MHz and downwards to 0.5 MHz. The reduction in the lower frequency provided an overlap with the underwater acoustics key comparison CCAUV.W-K1 which covers the range 1 kHz to 0.5 MHz. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  19. Computational Electromagnetic Analysis in a Human Head Model with EEG Electrodes and Leads Exposed to RF-Field Sources at 915 MHz and 1748 MHz

    PubMed Central

    Angelone, Leonardo M.; Bit-Babik, Giorgi; Chou, Chung-Kwang

    2010-01-01

    An electromagnetic analysis of a human head with EEG electrodes and leads exposed to RF-field sources was performed by means of Finite-Difference Time-Domain simulations on a 1-mm3 MRI-based human head model. RF-field source models included a half-wave dipole, a patch antenna, and a realistic CAD-based mobile phone at 915 MHz and 1748 MHz. EEG electrodes/leads models included two configurations of EEG leads, both a standard 10–20 montage with 19 electrodes and a 32-electrode cap, and metallic and high resistive leads. Whole-head and peak 10-g average SAR showed less than 20% changes with and without leads. Peak 1-g and 10-g average SARs were below the ICNIRP and IEEE guideline limits. Conversely, a comprehensive volumetric assessment of changes in the RF field with and without metallic EEG leads showed an increase of two orders of magnitude in single-voxel power absorption in the epidermis and a 40-fold increase in the brain during exposure to the 915 MHz mobile phone. Results varied with the geometry and conductivity of EEG electrodes/leads. This enhancement confirms the validity of the question whether any observed effects in studies involving EEG recordings during RF-field exposure are directly related to the RF fields generated by the source or indirectly to the RF-field-induced currents due to the presence of conductive EEG leads. PMID:20681803

  20. Computational electromagnetic analysis in a human head model with EEG electrodes and leads exposed to RF-field sources at 915 MHz and 1748 MHz.

    PubMed

    Angelone, Leonardo M; Bit-Babik, Giorgi; Chou, Chung-Kwang

    2010-07-01

    An electromagnetic analysis of a human head with EEG electrodes and leads exposed to RF-field sources was performed by means of Finite-Difference Time-Domain simulations on a 1-mm(3) MRI-based human head model. RF-field source models included a half-wave dipole, a patch antenna, and a realistic CAD-based mobile phone at 915 MHz and 1748 MHz. EEG electrodes/leads models included two configurations of EEG leads, both a standard 10-20 montage with 19 electrodes and a 32-electrode cap, and metallic and high resistive leads. Whole-head and peak 10-g average SAR showed less than 20% changes with and without leads. Peak 1-g and 10-g average SARs were below the ICNIRP and IEEE guideline limits. Conversely, a comprehensive volumetric assessment of changes in the RF field with and without metallic EEG leads showed an increase of two orders of magnitude in single-voxel power absorption in the epidermis and a 40-fold increase in the brain during exposure to the 915 MHz mobile phone. Results varied with the geometry and conductivity of EEG electrodes/leads. This enhancement confirms the validity of the question whether any observed effects in studies involving EEG recordings during RF-field exposure are directly related to the RF fields generated by the source or indirectly to the RF-field-induced currents due to the presence of conductive EEG leads.

  1. Behavior, physiology, and energy deposition in rats chronically exposed to 2450-MHz radiation

    SciTech Connect

    D'Andrea, J.A.; Gandhi, O.P.

    1987-11-01

    The research program was initiated to determine both the specific absorption rate (SAR) and the behavioral and physiological consequences of chronic c-w microwave radiation exposure at 2450 MHz in the laboratory rat. Whole-body average and local SARs at discrete sites within the body of rats and mice were determined experimentally using different exposure systems and analytical techniques. The whole-body average SAR and the distribution of SAR within the body depends on a variety of factors: type of exposure system, polarization of the field, size of the animal, and angle of radiation incident on the body. Three experiments were conducted to determine the effects of chronic exposure to 2450-MHz microwave radiation on several measures of rat behavior and physiology. Groups of rats were exposed intermittently to 2450-MHz radiation at power densities of 0.5 mW/sq. cm. or 2.5 mW/sq. cm. for 90 days.

  2. A low-loss linear analog phase modulator for 8415 MHz transponder application

    NASA Technical Reports Server (NTRS)

    Mysoor, N.

    1989-01-01

    A breadboard single-section low-loss analog phase modulator with good thermal stability for a spacecraft transponder application has been analyzed, fabricated, and evaluated. A linear phase shift of 70 degrees with a linearity tolerance of plus or minus 7 percent was measured for this modulator from 8257 to 8634 MHz over the temperature range -20 C to 75 C. The measured insertion loss and the static delay variation with temperature were within 2 plus or minus 0.3 dB and 0.16 ps/C, respectively. Four sections will be cascaded to provide the X-band (8415 MHz) phase modulator. The generic modulator design can also be utilized at 7950 to 8075 MHz followed by X4 multiplication to provide modulation of a Ka-band downlink signal.

  3. Theoretical and experimental analysis of a piezoelectric plate connected to a negative capacitance at MHz frequencies

    NASA Astrophysics Data System (ADS)

    Mansoura, S. A.; Benard, P.; Morvan, B.; Maréchal, P.; Hladky-Hennion, A.-C.; Dubus, B.

    2015-11-01

    In this paper, a theoretical and experimental study of the electric impedance of a piezoelectric plate connected to a negative capacitance is performed in the MHz frequency range. The negative capacitance is realized with a circuit using current conveyors (CCII+). This circuit allows us to achieve important values of negative capacitance, of the same order of the static capacitance of the piezoelectric plate studied. Mason’s model is considered for the theoretical characterization of the piezoelectric plate connected to the negative capacitance circuit. The experimental results show a large tunability of the frequency of the piezoelectric parallel resonance over a range of 1.1 MHz to 1.28 MHz. Moreover, according to the value of the negative capacitance, the effective electromechanical coupling factor of the piezoelectric plate is evaluated. With a very good agreement with the theoretical estimation, an increase of approximately 50% of the effective electromechanical coupling factor is experimentally measured.

  4. Measurement of DNA damage after exposure to 2450 MHz electromagnetic radiation.

    PubMed

    Malyapa, R S; Ahern, E W; Straube, W L; Moros, E G; Pickard, W F; Roti Roti, J L

    1997-12-01

    Recent reports suggest that exposure to 2450 MHz electromagnetic radiation causes DNA single-strand breaks (SSBs) and double-strand breaks (DSBs) in cells of rat brain irradiated in vivo (Lai and Singh, Bioelectromagnetics 16, 207-210, 1995; Int. J. Radiat. Biol. 69, 513-521, 1996). Therefore, we endeavored to determine if exposure of cultured mammalian cells in vitro to 2450 MHz radiation causes DNA damage. The alkaline comet assay (single-cell gel electrophoresis), which is reportedly the most sensitive method to assay DNA damage in individual cells, was used to measure DNA damage after in vitro 2450 MHz irradiation. Exponentially growing U87MG and C3H 10T1/2 cells were exposed to 2450 MHz continuous-wave (CW) radiation in specially designed radial transmission lines (RTLs) that provided relatively uniform microwave exposure. Specific absorption rates (SARs) were calculated to be 0.7 and 1.9 W/kg. Temperatures in the RTLs were measured in real time and were maintained at 37 +/- 0.3 degrees C. Every experiment included sham exposure(s) in an RTL. Cells were irradiated for 2 h, 2 h followed by a 4-h incubation at 37 degrees C in an incubator, 4 h and 24 h. After these treatments samples were subjected to the alkaline comet assay as described by Olive et al. (Exp. Cell Res. 198, 259-267, 1992). Images of comets were digitized and analyzed using a PC-based image analysis system, and the "normalized comet moment" and "comet length" were determined. No significant differences were observed between the test group and the controls after exposure to 2450 MHz CW irradiation. Thus 2450 MHz irradiation does not appear to cause DNA damage in cultured mammalian cells under these exposure conditions as measured by this assay.

  5. IBS and expected luminosity performance for RHIC beams at top energy with 56 MHz SRF cavity

    SciTech Connect

    Fedotov,A.

    2008-10-01

    The purpose of RF system in RHIC is to capture injected bunches, accelerate them to the top energy, and store bunches at the top energy for many hours. The accelerating RF system operates at harmonic number h=360 of the particle revolution frequency f=78.196 kHz, which corresponds to 28.15MHz. The storage RF system accepts the shortened bunches at top energy and provides longitudinal focusing to keep these bunches short during the store time (collision mode). The storage system operates at harmonic number h=7x360=2520, which corresponds to an RF frequency of 197.05 MHz [1]. Recently, an upgrade of storage RF system with a superconducting 56 MHz cavity was proposed [2]. This upgrade will provide significant increase in the acceptance of storage RF bucket. Presently, the short bunch length for collisions is obtained via RF gymnastics with bunch rotation (called re-bucketing), because the length of 197MHz bucket of 5 nsec is too short to accommodate long bunches otherwise. However, due to bucket non-linearity and hardware complications some increase in the longitudinal emittance occurs during re-bucketing. The 56MHz cavity will produce sufficiently short bunches which would allow one to operate without re-bucketing procedure. This Note summarizes simulation of beam evolution due to Intra-beam scattering (IBS) for beam parameters expected with the 56 MHz SRF cavity upgrade. Expected luminosity improvement is shown both for Au ions at 100 GeV/nucleon and for protons at 250 GeV.

  6. Non-Io decametric radiation from Jupiter at frequencies above 30 MHz

    NASA Technical Reports Server (NTRS)

    Barrow, C. H.; Desch, M. D.

    1980-01-01

    Jovian Non-Io decametric radio events extending to frequencies of 30 MHz and above have been found in the Meudon-Nancay observations during 1978 and 1979, in the Voyager 1 PRA observations during February and March, 1979 and in the University of Colorado Radio Astronomy Observatory catalogue for 1960 to 1975. These events, which appear to be mostly associated with the Jovian A-source, query the existence of a cut-off, a little below 30 MHz, for the Non-Io emission and suggest the possibility of a single mechanism for both the Io and the Non-Io radiation.

  7. A MHz speed wavelength sweeping for ultra-high speed FBG interrogation

    NASA Astrophysics Data System (ADS)

    Kim, Gyeong Hun; Lee, Hwi Don; Eom, Tae Joong; Jeong, Myung Yung; Kim, Chang-Seok

    2015-09-01

    We demonstrated a MHz speed wavelength-swept fiber laser based on the active mode locking (AML) technique and applied to interrogation system of an array of fiber Bragg grating (FBG) sensors. MHz speed wavelength sweeping of wavelength-swept fiber laser can be obtained by programmable frequency modulation of the semiconductor optical amplifier (SOA) without any wavelength tunable filter. Both static and dynamic strain measurement of FBG sensors were successfully characterized with high linearity of an R-square value of 0.9999 at sweeping speed of 50 kHz.

  8. Airborne urban/suburban noise measurements at 121.5/243 MHz

    NASA Technical Reports Server (NTRS)

    Taylor, R. E.; Hill, J. S.

    1977-01-01

    An airborne measurement of the terrestrial, radio-frequency (RF) noise environment over U.S. metropolitan urban/suburban areas has been made at the 121.5/243 MHz emergency-distress search and rescue (S&R) communications frequencies. Profile contour plots of antenna-noise temperature for U.S.A. East Coast and mid-west urban/suburban areas is presented for daytime/nighttime observations at 121.5/243 MHz. These plots are helpful for compiling radio-noise environment maps; in turn useful for designing satellite-aided, emergency-distress search and rescue communication systems.

  9. UHF EPR spectrometer operating at frequencies between 400 MHz and 1 GHz.

    PubMed

    Quine, Richard W; Rinard, George A; Shi, Yilin; Buchanan, Laura; Biller, Joshua R; Eaton, Sandra S; Eaton, Gareth R

    2016-07-01

    A spectrometer was designed and constructed to facilitate measurements of T1, T2, spin echo signal-to-noise, and resonator quality factor, Q, between about 400 and 1000 MHz. Pulse patterns are generated at 250 MHz and mixed with the output from a second source to perform excitation and detection. A cross-loop resonator was constructed in which the same sample could be measured in the same resonator over the full range of frequencies. An air-core, 4-coil, water-cooled electromagnet with a large experimental volume was built.

  10. Imaging disulfide dinitroxides at 250 MHz to monitor thiol redox status.

    PubMed

    Elajaili, Hanan; Biller, Joshua R; Rosen, Gerald M; Kao, Joseph P Y; Tseytlin, Mark; Buchanan, Laura A; Rinard, George A; Quine, Richard W; McPeak, Joseph; Shi, Yilin; Eaton, Sandra S; Eaton, Gareth R

    2015-11-01

    Measurement of thiol-disulfide redox status is crucial for characterization of tumor physiology. The electron paramagnetic resonance (EPR) spectra of disulfide-linked dinitroxides are readily distinguished from those of the corresponding monoradicals that are formed by cleavage of the disulfide linkage by free thiols. EPR spectra can thus be used to monitor the rate of cleavage and the thiol redox status. EPR spectra of (1)H,(14)N- and (2)H,(15)N-disulfide dinitroxides and the corresponding monoradicals resulting from cleavage by glutathione have been characterized at 250 MHz, 1.04 GHz, and 9 GHz and imaged by rapid-scan EPR at 250 MHz.

  11. 47 CFR 90.1425 - Resolution of disputes after grant of the upper 700 MHz D block license.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Safety Broadband Licensee, the Operating Company, the Network Assets Holder, and the Upper 700 MHz D... Homeland Security Bureau and the Wireless Telecommunications Bureau are delegated joint responsibility...

  12. 47 CFR 27.1325 - Resolution of disputes after grant of the upper 700 MHz D block license.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 700 MHz D Block licensee, the Operating Company, the Network Assets Holder and the Public Safety... Security Bureau and the Wireless Telecommunications Bureau are delegated joint responsibility...

  13. Thickness design, fabrication, and evaluation of 100-MHz polyurea ultrasonic transducer.

    PubMed

    Nakazawa, Marie; Tabaru, Masaya; Aoyagi, Takahiro; Nakamura, Kentaro; Ueha, Sadayuki

    2013-10-01

    In this paper, we present a polyurea transducer that works at 100 MHz under water. The transducer was designed using an equivalent circuit model so that an aluminum (top)-polyurea-aluminum (bottom)-polyimide layer had a resonant frequency of 100 MHz and output sound pressure became maximum at that frequency. The thicknesses of the top aluminum electrode, polyurea, and bottom aluminum electrode were determined to be 3.3, 3.5, and 1.7 μm, respectively. A 100-MHz polyurea transducer with the designed thickness was fabricated using deposition equipment. To evaluate the performance of the designed and fabricated polyurea transducer, transmission-reception experiments with pulsed and burst waves were carried out. The results show that transmitting and receiving ultrasounds at a frequency of 100 MHz are possible as expected with the thickness design. To evaluate actual use, B-mode imaging of an onion was also performed using the transducer, which was formed into a line-focused shape. The result shows that the outer layer of the onion, of 0.1 to 0.2 mm thickness, was successfully imaged.

  14. 47 CFR 90.357 - Frequencies for LMS systems in the 902-928 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Frequencies for LMS systems in the 902-928 MHz band. 90.357 Section 90.357 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Intelligent Transportation Systems Radio...

  15. 77 FR 5406 - Amateur Radio Use of the Allocation at 5 MHz

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... COMMISSION 47 CFR Parts 2 and 97 Amateur Radio Use of the Allocation at 5 MHz AGENCY: Federal Communications... efficient and effective use by the Amateur Radio Service of five channels in the 5330.5-5406.4 kHz band (the... proceeding, in which it proposed to adopt the three rule modifications requested by the American Radio...

  16. 75 FR 33748 - Amateur Radio Use of the Allocation at 5 MHz

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ... COMMISSION 47 CFR Parts 2 and 97 Amateur Radio Use of the Allocation at 5 MHz AGENCY: Federal Communications... to the Amateur Radio Service. Specifically, the Commission proposes to modify the rules pertaining to... Commission proposes to amend parts 2 and 97 of the Commission's Rules relating to the Amateur Radio...

  17. Dynamic Wetting at MHz Vibration: Simple and Complex Liquid Films on an Ultrasonic Actuator

    NASA Astrophysics Data System (ADS)

    Manor, Ofer; Althshuler, Gennady; Mhatre, Sameer; Abezgauz, Ludmila

    2015-11-01

    We excite simple and complex liquid films on ultrasonic actuators that produce a MHz substrate vibration in the form of a surface acoustic wave (SAW). Transfer of momentum from the MHz vibration in the solid substrate to the neighboring liquid translates to convective stresses within the liquid and on the film free boundary. These stresses further invoke various flow mechanisms, also known as acoustic streaming and may support dynamic wetting or dewetting of liquid films. In particular, we use theory and experiment to study the interplay between viscous, capillary, and the vibrational dynamics of liquid films and their internal structure. We employ MHz ultrasonic actuators to study the dynamic wetting and dewetting of free and confined films of oil and water/surfactant solutions on flat surfaces and within microfluidic channels. We further excite films of evaporating solutions and suspensions in order to study the active influence of the solid vibration on the geometry of the molecule and particle patterns that are deposited in this process. We show the physics underlying these different systems may be explained using the convective dynamics the MHz substrate vibration excites in liquid films.

  18. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  19. 47 CFR 27.65 - Acceptance of interference in 2000-2020 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Acceptance of interference in 2000-2020 MHz. 27.65 Section 27.65 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.65 Acceptance...

  20. 47 CFR 27.303 - Upper 700 MHz commercial and public safety coordination zone.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Upper 700 MHz commercial and public safety coordination zone. 27.303 Section 27.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and...

  1. 47 CFR 27.303 - Upper 700 MHz commercial and public safety coordination zone.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Upper 700 MHz commercial and public safety coordination zone. 27.303 Section 27.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and...

  2. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  3. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  4. 47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... public/private partnership. 27.1308 Section 27.1308 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private... require or allow shall have the obligation to build out the Shared Wireless Broadband Network, as...

  5. 47 CFR 27.303 - Upper 700 MHz commercial and public safety coordination zone.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Upper 700 MHz commercial and public safety coordination zone. 27.303 Section 27.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and...

  6. 47 CFR 27.303 - Upper 700 MHz commercial and public safety coordination zone.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Upper 700 MHz commercial and public safety coordination zone. 27.303 Section 27.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and...

  7. 47 CFR 27.1303 - Upper 700 MHz D Block license conditions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....1303 Section 27.1303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1303 Upper... Block licensee shall have the exclusive right to build and operate the shared wireless broadband...

  8. 47 CFR 27.65 - Acceptance of interference in 2000-2020 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Acceptance of interference in 2000-2020 MHz. 27.65 Section 27.65 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.65 Acceptance...

  9. Storage effects on dielectric properties of eggs from 10 to 1800 MHz.

    PubMed

    Guo, W; Trabelsi, S; Nelson, S O; Jones, D R

    2007-06-01

    The dielectric constant and loss factor of egg albumen and egg yolk over the frequency range from 10 to 1800 MHz were measured at 24 degrees C at weekly intervals during 5-wk storage at 15 degrees C. Moisture and ash contents of albumen and yolk, as well as Haugh unit and yolk index, were also measured. The dielectric constant and loss factor of albumen were higher than those of yolk. Linear relationships were evident between the log of frequency, below about 1000 MHz, and the log of loss factor of albumen as well as that of yolk. The dielectric constants of albumen and yolk at 10 MHz were lower than those of fresh albumen and yolk when eggs were stored at 15 degrees C for 1 wk. However, after 2 wk in storage these dielectric constants rose and remained at higher levels for the rest of the 5-wk period. At frequencies of 100 MHz and higher, the dielectric constant was essentially constant during the entire storage period. Storage had much less influence on the loss factor of either albumen or yolk. In general, the moisture content and ash content of albumen and yolk decreased slightly as eggs aged. The moisture content of yolk increased somewhat with storage, and there was a corresponding decrease in albumen moisture content. The freshness qualities, Haugh unit and yolk index, also decreased as eggs aged. No obvious correlation between dielectric properties and moisture content, ash content, Haugh unit, or yolk index was observed.

  10. A 1.6 MHz survey of the galactic background radio emission

    NASA Technical Reports Server (NTRS)

    Ellis, G. R. A.; Mendillo, M.

    1987-01-01

    Observations of the galactic radio emission at 1.6 MHz have been made during the current solar activity minimum using a radio telescope with a beamwidth of 25 deg. The radiation intensity was mapped for six declinations between -12 and -72 degrees and from 1000 to 0500 hours R.A.

  11. VizieR Online Data Catalog: 1415MHz Survey of Bright Galaxies (Hummel, 1980)

    NASA Astrophysics Data System (ADS)

    Hummel, E.

    2003-11-01

    The radio continuum radiation at 1415MHz of 450 galaxies was observed with the Westerbork Synthesis Radio Telescope. 190 galaxies were detected. The survey provides data on the total intensity and on the structure of the radiation. The detection limit for point sources is 10mJy and the resolution is about 23" on average. (2 data files).

  12. Concept em design of the 650 MHz cavities for the Project X

    SciTech Connect

    Yakovlev, V.; Champion, M.; Gonin, I.; Lunin, A.; Kazakov, S.; Khabiboulline, T.; Solyak, N.; Saini, A.; /Fermilab

    2011-03-01

    Concept of the 650 MHz cavities for the Project X is presented. Choice of the basic parameters, i.e., number of cells, geometrical {beta}, apertures, coupling coefficients, etc., is discussed. The cavity optimization criteria are formulated. Results of the RF design are presented for the cavities of both the low-energy and high-energy sections.

  13. 47 CFR 15.229 - Operation within the band 40.66-40.70 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation within the band 40.66-40.70 MHz. 15.229 Section 15.229 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.229 Operation within the band...

  14. 47 CFR 15.250 - Operation of wideband systems within the band 5925-7250 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation of wideband systems within the band 5925-7250 MHz. 15.250 Section 15.250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.250...

  15. 47 CFR 15.240 - Operation in the band 433.5-434.5 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation in the band 433.5-434.5 MHz. 15.240 Section 15.240 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.240 Operation in the band...

  16. 47 CFR 15.241 - Operation in the band 174-216 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation in the band 174-216 MHz. 15.241 Section 15.241 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.241 Operation in the band...

  17. 47 CFR 15.239 - Operation in the band 88-108 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.239 Operation in the band 88-108 MHz. (a) Emissions from the intentional radiator shall be confined within a band 200 kHz wide centered... the general radiated emission limits in § 15.209. (d) A custom built telemetry intentional...

  18. 47 CFR 15.223 - Operation in the band 1.705-10 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Operation in the band 1.705-10 MHz. 15.223 Section 15.223 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.223 Operation in the band...

  19. 47 CFR 15.223 - Operation in the band 1.705-10 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation in the band 1.705-10 MHz. 15.223 Section 15.223 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.223 Operation in the band...

  20. 47 CFR 15.239 - Operation in the band 88-108 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.239 Operation in the band 88-108 MHz. (a) Emissions from the intentional radiator shall be confined within a band 200 kHz wide centered... the general radiated emission limits in § 15.209. (d) A custom built telemetry intentional...

  1. 47 CFR 15.225 - Operation within the band 13.110-14.010 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Operation within the band 13.110-14.010 MHz. 15.225 Section 15.225 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.225 Operation within the band...

  2. 47 CFR 15.241 - Operation in the band 174-216 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation in the band 174-216 MHz. 15.241 Section 15.241 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.241 Operation in the band...

  3. 47 CFR 15.241 - Operation in the band 174-216 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation in the band 174-216 MHz. 15.241 Section 15.241 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.241 Operation in the band...

  4. 47 CFR 15.250 - Operation of wideband systems within the band 5925-7250 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation of wideband systems within the band 5925-7250 MHz. 15.250 Section 15.250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.250...

  5. 47 CFR 15.223 - Operation in the band 1.705-10 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation in the band 1.705-10 MHz. 15.223 Section 15.223 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.223 Operation in the band...

  6. 47 CFR 15.223 - Operation in the band 1.705-10 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation in the band 1.705-10 MHz. 15.223 Section 15.223 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.223 Operation in the band...

  7. 47 CFR 15.250 - Operation of wideband systems within the band 5925-7250 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Operation of wideband systems within the band 5925-7250 MHz. 15.250 Section 15.250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.250...

  8. 47 CFR 15.243 - Operation in the band 890-940 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation in the band 890-940 MHz. 15.243 Section 15.243 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.243 Operation in the band...

  9. 47 CFR 15.227 - Operation within the band 26.96-27.28 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation within the band 26.96-27.28 MHz. 15.227 Section 15.227 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.227 Operation within the band...

  10. 47 CFR 15.239 - Operation in the band 88-108 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.239 Operation in the band 88-108 MHz. (a) Emissions from the intentional radiator shall be confined within a band 200 kHz wide centered... the general radiated emission limits in § 15.209. (d) A custom built telemetry intentional...

  11. 47 CFR 15.243 - Operation in the band 890-940 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation in the band 890-940 MHz. 15.243 Section 15.243 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.243 Operation in the band...

  12. 47 CFR 15.225 - Operation within the band 13.110-14.010 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation within the band 13.110-14.010 MHz. 15.225 Section 15.225 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.225 Operation within the band...

  13. 47 CFR 15.241 - Operation in the band 174-216 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Operation in the band 174-216 MHz. 15.241 Section 15.241 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.241 Operation in the band...

  14. 47 CFR 15.227 - Operation within the band 26.96-27.28 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation within the band 26.96-27.28 MHz. 15.227 Section 15.227 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.227 Operation within the band...

  15. 47 CFR 15.229 - Operation within the band 40.66-40.70 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Operation within the band 40.66-40.70 MHz. 15.229 Section 15.229 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.229 Operation within the band...

  16. 47 CFR 15.241 - Operation in the band 174-216 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation in the band 174-216 MHz. 15.241 Section 15.241 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.241 Operation in the band...

  17. 47 CFR 15.250 - Operation of wideband systems within the band 5925-7250 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation of wideband systems within the band 5925-7250 MHz. 15.250 Section 15.250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.250...

  18. 47 CFR 15.240 - Operation in the band 433.5-434.5 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation in the band 433.5-434.5 MHz. 15.240 Section 15.240 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.240 Operation in the band...

  19. 47 CFR 15.239 - Operation in the band 88-108 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.239 Operation in the band 88-108 MHz. (a) Emissions from the intentional radiator shall be confined within a band 200 kHz wide centered... the general radiated emission limits in § 15.209. (d) A custom built telemetry intentional...

  20. 47 CFR 15.229 - Operation within the band 40.66-40.70 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Operation within the band 40.66-40.70 MHz. 15.229 Section 15.229 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.229 Operation within the band...

  1. 47 CFR 15.243 - Operation in the band 890-940 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation in the band 890-940 MHz. 15.243 Section 15.243 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.243 Operation in the band...

  2. 47 CFR 15.225 - Operation within the band 13.110-14.010 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation within the band 13.110-14.010 MHz. 15.225 Section 15.225 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.225 Operation within the band...

  3. 47 CFR 15.227 - Operation within the band 26.96-27.28 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation within the band 26.96-27.28 MHz. 15.227 Section 15.227 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.227 Operation within the band...

  4. 47 CFR 15.227 - Operation within the band 26.96-27.28 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation within the band 26.96-27.28 MHz. 15.227 Section 15.227 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.227 Operation within the band...

  5. 47 CFR 15.229 - Operation within the band 40.66-40.70 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation within the band 40.66-40.70 MHz. 15.229 Section 15.229 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.229 Operation within the band...

  6. 47 CFR 15.240 - Operation in the band 433.5-434.5 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Operation in the band 433.5-434.5 MHz. 15.240 Section 15.240 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.240 Operation in the band...

  7. 47 CFR 15.240 - Operation in the band 433.5-434.5 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation in the band 433.5-434.5 MHz. 15.240 Section 15.240 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.240 Operation in the band...

  8. 47 CFR 15.243 - Operation in the band 890-940 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation in the band 890-940 MHz. 15.243 Section 15.243 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.243 Operation in the band...

  9. 47 CFR 15.250 - Operation of wideband systems within the band 5925-7250 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation of wideband systems within the band 5925-7250 MHz. 15.250 Section 15.250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.250...

  10. 47 CFR 15.240 - Operation in the band 433.5-434.5 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation in the band 433.5-434.5 MHz. 15.240 Section 15.240 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.240 Operation in the band...

  11. 47 CFR 15.227 - Operation within the band 26.96-27.28 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Operation within the band 26.96-27.28 MHz. 15.227 Section 15.227 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.227 Operation within the band...

  12. 47 CFR 15.239 - Operation in the band 88-108 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.239 Operation in the band 88-108 MHz. (a) Emissions from the intentional radiator shall be confined within a band 200 kHz wide centered... the general radiated emission limits in § 15.209. (d) A custom built telemetry intentional...

  13. 47 CFR 15.225 - Operation within the band 13.110-14.010 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation within the band 13.110-14.010 MHz. 15.225 Section 15.225 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.225 Operation within the band...

  14. 47 CFR 15.223 - Operation in the band 1.705-10 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation in the band 1.705-10 MHz. 15.223 Section 15.223 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.223 Operation in the band...

  15. 47 CFR 15.229 - Operation within the band 40.66-40.70 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation within the band 40.66-40.70 MHz. 15.229 Section 15.229 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.229 Operation within the band...

  16. 47 CFR 15.225 - Operation within the band 13.110-14.010 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Operation within the band 13.110-14.010 MHz. 15.225 Section 15.225 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.225 Operation within the band...

  17. 47 CFR 27.1303 - Upper 700 MHz D Block license conditions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1303 Upper... this winning bidder has entered, with the Public Safety Broadband Licensee and other related entities... must not discontinue, reduce, or impair service to public safety users unless and until, pursuant...

  18. 47 CFR 27.1303 - Upper 700 MHz D Block license conditions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1303 Upper... this winning bidder has entered, with the Public Safety Broadband Licensee and other related entities... must not discontinue, reduce, or impair service to public safety users unless and until, pursuant...

  19. 78 FR 1188 - Commercial Operations in the 3550-3650 MHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... Citizens Broadband Radio Service under part 95 of its rules for shared small cell use in the 3550-3650 MHz... Satellite Service (FSS) users. The Commission also seeks comment on how the unique characteristics of small cells may help reduce the need for geographic protections and enable shared access of the 3.5 GHz...

  20. 78 FR 59903 - Emission Mask Requirements for Digital Technologies on 800 MHz NPSPAC Channels; Analog FM...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ... COMMISSION 47 CFR Part 90 Emission Mask Requirements for Digital Technologies on 800 MHz NPSPAC Channels... Petition for Rulemaking filed by Harris Corporation (Harris). The NPRM proposes to require digital... affect reporting, recordkeeping and other compliance requirements. The NPRM proposes requiring...

  1. 77 FR 19575 - Promoting Interoperability in the 700 MHz Commercial Spectrum; Interoperability of Mobile User...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... meaningful access to a wide range of advanced devices. The result, they argue, is that this spectrum is being... interoperability requirement in the 700 MHz band is necessary to obtain affordable, advanced mobile devices to... on the Deployment of Advanced Broadband Services. The record to date suggests that, unless...

  2. 1800 MHz in vitro exposure device for experimental studies on the effects of mobile communication systems.

    PubMed

    Ardoino, L; Lopresto, V; Mancini, S; Pinto, R; Lovisolo, G A

    2004-01-01

    A wire patch cell (WPC) operating at the uplink frequency band of GSM 1800 MHz has been designed for in vitro experiments with the aim of investigating the possible biological effects of electromagnetic radiation associated with cellular phones. The 1800 MHz WPC design is a direct descendant of the original 900 MHz WPC introduced by Laval et al. This system provides a homogeneous specific absorption rate distribution, using four 3.5 cm petri dishes simultaneously. Numerical dosimetry has been performed using a commercial code (CST Microwave Studio), in order to evaluate accurately the efficiency of the structure (in terms of W kg(-1) per 1 W input power) and the distribution in the chosen biological target. The numerical results have been confirmed by experimental measurements performed by measuring thermal increase due to a high power impulse. The efficiency of the structure is 1.25 +/- 25% W kg(-1) per 1 W input power higher than the efficiency of the 900 MHz WPC. A few adjustments have been made in order to use the WPC in a standard incubator and to avoid thermal increases related to the radio frequency exposure. This exposure system has been adopted for the experiments scheduled in the RAMP and GUARD projects (VFPE).

  3. 47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Public Safety 700 MHz Nationwide Broadband Network. 90.18 Section 90.18 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Public Safety Radio Pool § 90.18 Public...

  4. 47 CFR 90.264 - Disaster communications between 2 and 10 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... capable of immediate change among the frequencies. (f) Only 2K80J3E, 100HA1A and those emission types... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Standards for Special Frequencies or Frequency Bands § 90.264 Disaster communications between 2 and 10 MHz. (a) The use of any particular...

  5. Performance of TES X-ray Microcalorimeters with AC Bias Read-Out at MHz Frequencies

    NASA Astrophysics Data System (ADS)

    Akamatsu, H.; Gottardi, L.; Adams, J.; Bandler, S.; Bruijn, M.; Chervenak, J.; Eckart, M.; Finkbeiner, F.; den Hartog, R.; Hoevers, H.; Kelley, R.; Kilbourne, C.; van der Kuur, J.; van den Linden, A. J.; Porter, F.; Sadleir, J.; Smith, S.; Kiviranta, M.

    2014-08-01

    At SRON we are developing Frequency Domain Multiplexing for the read-out of superconducting transition edge sensor microcalorimeters for future X-ray astrophysical missions. We will report on the performance of Goddard Space Flight Center pixels under AC bias in the MHz frequency range. Superconducting flux transformers are used to improve the impedance matching between the low ohmic TESs and the SQUID. We connected 5 pixels to the LC filters with resonant frequencies ranging between 1 and 5 MHz. For X-ray photons of 6 keV we measured a best X-ray energy resolution of 3.6 eV at 1.4 MHz, consistent with the integrated Noise Equivalent Power. In addition, we improved the electrical circuit by optimizing the coupling ratio of the impedance matching transformer. In addition, we improved electrical circuit for impedance matching; modified transformer coupling ratio. As a result, we got the integrated noise equivalent power resolution of 2.7 eV at 2.5 MHz. A characterization of the detector response as a function of the AC bias voltage, bias frequency and the applied magnetic field is presented.

  6. 47 CFR 25.265 - Acceptance of interference in 2000-2020 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Acceptance of interference in 2000-2020 MHz. 25.265 Section 25.265 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.265 Acceptance of interference in 2000-2020...

  7. 47 CFR 25.265 - Acceptance of interference in 2000-2020 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Acceptance of interference in 2000-2020 MHz. 25.265 Section 25.265 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.265 Acceptance of interference in 2000-2020...

  8. 47 CFR 87.199 - Special requirements for 406.0-406.1 MHz ELTs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Atmospheric Administration (NOAA), the United States Program Manager for the 406.0-406.1 MHz COSPAS/SARSAT... registration card printed with the ELT identification code addressed to: NOAA/SARSAT Beacon Registration, E/SP3... information as required by NOAA. The registration card must also contain information regarding...

  9. 47 CFR 90.357 - Frequencies for LMS systems in the 902-928 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Intelligent Transportation Systems Radio Service § 90.357 Frequencies for LMS systems in the 902-928 MHz band. (a) Multilateration LMS systems will be... 47 Telecommunication 5 2011-10-01 2011-10-01 false Frequencies for LMS systems in the 902-928...

  10. Imaging Buried Culverts Using Ground Penetrating Radar: Comparing 100 MHZ Through 1 GHZ Antennae

    NASA Astrophysics Data System (ADS)

    Abdul Aziz, A.; Stewart, R. R.; Green, S. L.

    2013-12-01

    *Aziz, A A aabdulaziz@uh.edu Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA Stewart, R R rrstewart@uh.edu Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA *Green, S L slgreen@yahoo.com Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA A 3D ground penetrating radar (GPR) survey, using three different frequency antennae, was undertaken to image buried steel culverts at the University of Houston's La Marque Geophysical Observatory 30 miles south of Houston, Texas. The four culverts, under study, support a road crossing one of the area's bayous. A 32 m by 4.5 m survey grid was designed on the road above the culverts and data were collected with 100 MHz, 250 MHz, and 1 GHz antennae. We used an orthogonal acquisition geometry for the three surveys. Inline sampling was from 1.0 cm to 10 cm (from 1 GHz to 100 MHz antenna) with inline and crossline spacings ranging from 0.2 m to 0.5 m. We used an initial velocity of 0.1 m/ns (from previous CMP work at the site) for the display purposes. The main objective of the study was to analyze the effect of different frequency antennae on the resultant GPR images. We are also interested in the accuracy and resolution of the various images, in addition to developing an optimal processing flow.The data were initially processed with standard steps that included gain enhancement, dewow and temporal-filtering, background suppression, and 2D migration. Various radar velocities were used in the 2D migration and ultimately 0.12 m/ns was used. The data are complicated by multipathing from the surface and between culverts (from modeling). Some of this is ameliorated via deconvolution. The top of each of the four culverts was evident in the GPR images acquired with the 250 MHz and 100 MHz antennas. For 1 GHz, the top of the culvert was not clear due to the signal's attenuation. The 250 MHz

  11. The effect of radio frequency interference on the 136- to 138-MHz return link and 400.5- to 401.5-MHz forward link of the Tracking and Data Relay Satellite System

    NASA Technical Reports Server (NTRS)

    Jenny, J.; Lyttle, J. D.

    1973-01-01

    The purpose is to update the RFI estimates in the 136- to 138-MHz VHF band and to make estimates for the first time for the 400.5- to 401.5-MHz UHF band. These preliminary predictions are based on primarily ITU frequency-registration data, with missing data bridged by engineering judgement.

  12. Preferred Frequency Range, Technical Characteristics, and Interference Assessment for a Microwave Observatory of Subsurface and Subcanopy (MOSS) for 1 MHZ Bandwidth in the Frequency Range of 100-150 MHz

    NASA Technical Reports Server (NTRS)

    Honeycutt, Bryan L.

    2005-01-01

    This document presents rationale for the frequency band selection, technical and operational characteristics of active spaceborne sensors in the Earth Exploration-Satellite Service (active), and interference assessment for a 1 MHz bandwidth sensor in the 100-150 MHz frequency range. The active spaceborne sensors expected to be operating in the frequency range of 100-150 MHz is the synthetic aperture radar (SAR) such as the MOSS. The technical characteristics, mission objectives, orbital parameters, design parameters, antenna characteristics, and preliminary interference assessment are given for MOSS. The purpose of the document is to provide rationale for the frequency band selection, technical characteristics of the active spaceborne sensor Microwave Observatory of Subsurface and Subcanopy (MOSS) that can be used to analyze the compatibility of active spaceborne sensors and other systems of 1 MHz bandwidth in the 100-150 MHz frequency band.

  13. 47 CFR 22.853 - Eligibility to hold interest in licenses limited to 3 MHz of spectrum.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... limited to 3 MHz of spectrum. 22.853 Section 22.853 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.853 Eligibility to hold interest in licenses limited to 3 MHz of spectrum... authorizing the use of more than three megahertz of spectrum (either shared or exclusive) in the 800...

  14. 47 CFR 22.853 - Eligibility to hold interest in licenses limited to 3 MHz of spectrum.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... limited to 3 MHz of spectrum. 22.853 Section 22.853 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.853 Eligibility to hold interest in licenses limited to 3 MHz of spectrum... authorizing the use of more than three megahertz of spectrum (either shared or exclusive) in the 800...

  15. 47 CFR 22.853 - Eligibility to hold interest in licenses limited to 3 MHz of spectrum.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... limited to 3 MHz of spectrum. 22.853 Section 22.853 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.853 Eligibility to hold interest in licenses limited to 3 MHz of spectrum... authorizing the use of more than three megahertz of spectrum (either shared or exclusive) in the 800...

  16. 47 CFR 22.853 - Eligibility to hold interest in licenses limited to 3 MHz of spectrum.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... limited to 3 MHz of spectrum. 22.853 Section 22.853 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.853 Eligibility to hold interest in licenses limited to 3 MHz of spectrum... authorizing the use of more than three megahertz of spectrum (either shared or exclusive) in the 800...

  17. 47 CFR 22.853 - Eligibility to hold interest in licenses limited to 3 MHz of spectrum.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... limited to 3 MHz of spectrum. 22.853 Section 22.853 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.853 Eligibility to hold interest in licenses limited to 3 MHz of spectrum... authorizing the use of more than three megahertz of spectrum (either shared or exclusive) in the 800...

  18. 47 CFR 27.1132 - Protection of incumbent operations in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Protection of incumbent operations in the 2150-2160/62 MHz band. 27.1132 Section 27.1132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz,...

  19. 47 CFR 27.1132 - Protection of incumbent operations in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Protection of incumbent operations in the 2150-2160/62 MHz band. 27.1132 Section 27.1132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz,...

  20. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  1. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  2. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  3. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  4. 47 CFR 22.877 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  5. 47 CFR 90.1425 - Resolution of disputes after grant of the upper 700 MHz D block license.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES 700 MHz Public/Private Partnership § 90.1425 Resolution of disputes after grant of the upper 700 MHz D block license. (a) The Public... license terms, the NSA, or the Commission's rules may result in cancellation of the Public...

  6. 47 CFR 90.1425 - Resolution of disputes after grant of the upper 700 MHz D block license.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES 700 MHz Public/Private Partnership § 90.1425 Resolution of disputes after grant of the upper 700 MHz D block license. (a) The Public... license terms, the NSA, or the Commission's rules may result in cancellation of the Public...

  7. 78 FR 31472 - Wireless Telecommunications Bureau Seeks To Supplement the Record on the 600 MHz Band Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ... Commission's Electronic Comment Filing System (ECFS). See Electronic Filing of Documents in Rulemaking... other countries would be most likely to adopt to allow for global harmonization of the 600 MHz spectrum... utilize the 600 MHz band effectively, particularly in terms of network and device design. Further, we...

  8. 77 FR 18991 - Channel Spacing and Bandwidth Limitations for Certain Economic Area (EA)-Based 800 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ...)-Based 800 MHz Specialized Mobile Radio (SMR) Licensees AGENCY: Federal Communications Commission. ACTION...)-based 800 MHz Specialized Mobile Radio (SMR) licensees to exceed a channel spacing and bandwidth... flexibility to deploy new technologies and to better utilize their licensed spectrum, while also...

  9. SIMULTANEOUS OBSERVATIONS OF GIANT PULSES FROM PULSAR PSR B0031-07 AT 38 AND 74 MHz

    SciTech Connect

    Tsai, Jr-Wei; Simonetti, John H.; Bear, Brandon; Gough, Jonathan D.; Newton, Joseph R.; Kavic, Michael

    2016-03-15

    The first station of the Long Wavelength Array was used to study PSR B0031-07 with simultaneous observations at 38 and 74 MHz. We found that 158 (0.35%) of the observed pulses at 38 MHz and 221 (0.49%) of the observed pulses at 74 MHz qualified as giant pulses (GPs) in a total of 12 hr of observations. GPs are defined as having flux densities of a factor of ≥90 times that of an average pulse (AP) at 38 MHz and ≥80 times that of an AP at 74 MHz. The cumulative distribution of pulse strength follows a power law, with an index of −4.2 at 38 MHz and −4.9 at 74 MHz. This distribution has a much more gradual slope than would be expected if observing the tail of a Gaussian distribution of normal pulses. The dispersion measure (DM) value which resulted in the largest signal to noise for dedispersed pulses was DM = 10.9 pc cm{sup −3}. No other transient pulses were detected in the data in the wide DM range from 1 to 5000 pc cm{sup −3}. There were 12 GPs detected within the same period from both 38 and 74 MHz, meaning that the majority of them are not generated in a wide band.

  10. Polar mesosphere summer echoes observed with the EISCAT 933-MHz radar and the CUPRI 46.9-MHz radar, their similarity to 224-MHz radar echoes, and their relation to turbulence and electron density profiles

    NASA Astrophysics Data System (ADS)

    Roettger, J.; Rietveld, M. T.; La Hoz, C.; Hall, T.; Kelley, M. C.

    1990-08-01

    The relation of the coherent echoes from the mesosphere detected by an incoherent scatter UHF radar to the echoes registered simultaneously with a portable radar interferometer is analyzed. It is demonstrated that these 933-MHz echoes are of the same character as the VHF radar polar mesosphere summer echoes. It is also noted that a narrow electron density observed in the incoherent scatter UHF radar data occurs at the comparable altitude as the portable radar interferometer polar mesosphere summer echoes (PMSE). Potential origins of the scattering process of the PMSEs observed in VHF and UHF are discussed, with focus placed on enhanced electron density fluctuations as well as steep electron density gradients in the presence of cluster ions in the cold polar mesosphere.

  11. Search for 150 MHz radio emission from extrasolar planets in the TIFR GMRT Sky Survey

    NASA Astrophysics Data System (ADS)

    Sirothia, S. K.; Lecavelier des Etangs, A.; Gopal-Krishna; Kantharia, N. G.; Ishwar-Chandra, C. H.

    2014-02-01

    The ongoing radio continuum TIFR GMRT Sky Survey (TGSS) using the Giant Metrewave Radio Telescope (GMRT) at 150 MHz offers an unprecedented opportunity to undertake a fairly deep search for low-frequency radio emission from nearby extrasolar planets. Currently TGSS images are available for a little over a steradian, encompassing 175 confirmed exoplanetary systems. We have searched for their radio counterparts in the TGSS (150 MHz), supplemented with a search in the NRAO VLA Sky Survey (NVSS) and the VLA FIRST survey at 1.4 GHz. For 171 planetary systems, we find no evidence of radio emission in the TGSS maps, placing a 3σ upper limit between 8.7 mJy and 136 mJy (median ~24.8 mJy) at 150 MHz. These non-detections include the 55 Cnc system for which we place a 3σ upper limit of 28 mJy at 150 MHz. Nonetheless, for four of the extrasolar planetary systems, we find TGSS radio sources coinciding with or located very close to their coordinates. One of these is 61 Vir: for this system a large radio flux density was predicted in the scenario involving magnetosphere-ionosphere coupling and rotation-induced radio emission. We also found 150 MHz emissions toward HD 86226 and HD 164509, where strong radio emission can be produced by the presence of a massive satellite orbiting a rapidly rotating planet. We also detected 150 MHz emission within a synthesized beam from 1RXS1609 b, a pre-main-sequence star harboring a ~14 Jupiter mass planet (or a brown dwarf). With a bright X-ray-UV star and a high mass, the planet 1RXS1609 b presents the best characteristics for rotation-induced emissions with high radio power. Deeper high-resolution observations toward these planetary systems are needed to discriminate between the possibilities of background radio-source and radio-loud planets. At 1.4 GHz, radio emission toward the planet-harboring pulsar PSR B1620-26 is detected in the NVSS. Emissions at 1.4 GHz are also detected toward the very-hot-Jupiter WASP-77A b (in the FIRST survey

  12. Improved Anatomical Specificity of Non-invasive Neuro-stimulation by High Frequency (5 MHz) Ultrasound

    NASA Astrophysics Data System (ADS)

    Li, Guo-Feng; Zhao, Hui-Xia; Zhou, Hui; Yan, Fei; Wang, Jing-Yao; Xu, Chang-Xi; Wang, Cong-Zhi; Niu, Li-Li; Meng, Long; Wu, Song; Zhang, Huai-Ling; Qiu, Wei-Bao; Zheng, Hai-Rong

    2016-04-01

    Low frequency ultrasound (<1 MHz) has been demonstrated to be a promising approach for non-invasive neuro-stimulation. However, the focal width is limited to be half centimeter scale. Minimizing the stimulation region with higher frequency ultrasound will provide a great opportunity to expand its application. This study first time examines the feasibility of using high frequency (5 MHz) ultrasound to achieve neuro-stimulation in brain, and verifies the anatomical specificity of neuro-stimulation in vivo. 1 MHz and 5 MHz ultrasound stimulation were evaluated in the same group of mice. Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects. Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation. The equivalent diameter (ED) of the stimulation region with 5 MHz ultrasound (0.29 ± 0.08 mm) is significantly smaller than that with 1 MHz (0.83 ± 0.11 mm). The response latency of 5 MHz ultrasound (45 ± 31 ms) is also shorter than that of 1 MHz ultrasound (208 ± 111 ms). Consequently, high frequency (5 MHz) ultrasound can successfully activate the brain circuits in mice. It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner.

  13. Improved Anatomical Specificity of Non-invasive Neuro-stimulation by High Frequency (5 MHz) Ultrasound

    PubMed Central

    Li, Guo-Feng; Zhao, Hui-Xia; Zhou, Hui; Yan, Fei; Wang, Jing-Yao; Xu, Chang-Xi; Wang, Cong-Zhi; Niu, Li-Li; Meng, Long; Wu, Song; Zhang, Huai-Ling; Qiu, Wei-Bao; Zheng, Hai-Rong

    2016-01-01

    Low frequency ultrasound (<1 MHz) has been demonstrated to be a promising approach for non-invasive neuro-stimulation. However, the focal width is limited to be half centimeter scale. Minimizing the stimulation region with higher frequency ultrasound will provide a great opportunity to expand its application. This study first time examines the feasibility of using high frequency (5 MHz) ultrasound to achieve neuro-stimulation in brain, and verifies the anatomical specificity of neuro-stimulation in vivo. 1 MHz and 5 MHz ultrasound stimulation were evaluated in the same group of mice. Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects. Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation. The equivalent diameter (ED) of the stimulation region with 5 MHz ultrasound (0.29 ± 0.08 mm) is significantly smaller than that with 1 MHz (0.83 ± 0.11 mm). The response latency of 5 MHz ultrasound (45 ± 31 ms) is also shorter than that of 1 MHz ultrasound (208 ± 111 ms). Consequently, high frequency (5 MHz) ultrasound can successfully activate the brain circuits in mice. It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner. PMID:27093909

  14. Search and rescue satellite (SARSAT) error analysis of the 406 MHz system

    NASA Technical Reports Server (NTRS)

    Yionoulis, S. M.; Eisner, A.; Maurer, H. A.

    1984-01-01

    A computer simulation investigated conditions encountered by the SARSAT 406 MHz system. Three and four parameter emergency transmitter (ET) location solutions were determined. Latitude and longitude, a frequency bias, and in the four-parameters solutions, a linear frequency drift term were estimated. Earth gravity, frequency drift, and measurement noise are the major error contributors to the ET position. Time-tag ET height and velocity errors, although significant are not routinely present. In the four-parameter solutions the drift error is eliminated; however, the sensitivity to measurement noise increases. Using the four-parameter pass solutions, the 406 MHz oscillator specifications can be relaxed and still satisfy the 5 km positioning requirement. Since a linear oscillator drift is removed in the four-parameter solution, only the measurement noise over 10-15 min is important.

  15. Perpendicularly Biased YIG Tuners for the Fermilab Recycler 52.809 MHz Cavities

    SciTech Connect

    Madrak, R.; Kashikhin, V.; Makarov, A.; Wildman, D.

    2013-09-13

    For NOvA and future experiments requiring high intensity proton beams, Fermilab is in the process of upgrading the existing accelerator complex for increased proton production. One such improvement is to reduce the Main Injector cycle time, by performing slip stacking, previously done in the Main Injector, in the now repurposed Recycler Ring. Recycler slip stacking requires new tuneable RF cavities, discussed separately in these proceedings. These are quarter wave cavities resonant at 52.809 MHz with a 10 kHz tuning range. The 10 kHz range is achieved by use of a tuner which has an electrical length of approximately one half wavelength at 52.809 MHz. The tuner is constructed from 31/8” diameter rigid coaxial line, with 5 inches of its length containing perpendicularly biased, Al doped Yttrium Iron Garnet (YIG). The tuner design, measurements, and high power test results are presented.

  16. Simulation of the High-Pass Filter for 56MHz Cavity for RHIC

    SciTech Connect

    Wu, Q.; Ben-Zvi, I.

    2010-05-23

    The 56MHz Superconducting RF (SRF) cavity for RHIC places high demands High Order Mode (HOM) damping, as well as requiring a high field at gap with fundamental mode frequency. The damper of 56MHz cavity is designed to extract all modes to the resistance load outside, including the fundamental mode. Therefore, the circuit must incorporate a high-pass filter to reflect back the fundamental mode into the cavity. In this paper, we show the good frequency response map obtained from our filter's design. We extract a circuit diagram from the microwave elements that simulate well the frequency spectrum of the finalized filter. We also demonstrate that the power dissipation on the filter over its frequency range is small enough for cryogenic cooling.

  17. Distribution of mean Doppler shift, spectral width, and skewness of coherent 50-MHz auroral radar backscatter

    SciTech Connect

    Watermann, J.; McNamara, A.G. ); Sofko, G.J.; Koehler, J.A. )

    1989-06-01

    Some 7,700 radio aurora spectra obtained from a six link 50-MHz CW radar network set up on the Canadian prairies were analyzed with respect to the distributions of mean Doppler shift, spectral width and skewness. A comparison with recently published SABRE results obtained at 153 MHz shows substantial differences in the distributions which are probably due to different experimental and geophysical conditions. The spectra are mostly broad with mean Doppler shifts close to zero (type II spectra). The typical groupings of type I and type III spectra are clearly identified. All types appear to be in general much more symmetric than those recorded with SABRE, and the skewness is only weakly dependent on the sign of the mean Doppler shift. Its distribution peaks near zero and shows a weak positive correlation with the type II Doppler shifts while the mostly positive type I Doppler shifts are slightly negatively correlated with the skewness.

  18. Development of 400- to 450-MHz RFQ resonator-cavity mechanical designs

    SciTech Connect

    Hansborough, L.D.

    1982-01-01

    In the development of the radio-frequency quadrupole (RFQ) linac, the resonator cavity's mechanical design may be a challenge similar in magnitude to that of the development of the accelerator structure itself. Experience with the all-copper 425-MHz RFQ proof-of-principle linac has demonstrated that the resonator cavity must be structurally stiff and easily tunable. This experience has led to development of copper-plated steel structures having vanes that may be moved within a cylinder for tuning. Design of a flexible vane-to-cylinder radio-frequency (rf) joint, the vane, and the cylinder has many constraints dictated by the small-diameter cavities in the 400-MHz-frequency region. Two types of flexible, mechanical vane-to-cylinder rf joints are being developed at Los Alamos: the C-seal and the rf clamp-joint.

  19. Development of a 402.5 MHz 140 kW Inductive Output Tube

    SciTech Connect

    R. Lawrence Ives; Michael Read, Robert Jackson

    2012-05-09

    This report contains the results of Phase I of an SBIR to develop a Pulsed Inductive Output Tube (IOT) with 140 kW at 400 MHz for powering H-proton beams. A number of sources, including single beam and multiple beam klystrons, can provide this power, but the IOT provides higher efficiency. Efficiencies exceeding 70% are routinely achieved. The gain is typically limited to approximately 24 dB; however, the availability of highly efficient, solid state drivers reduces the significance of this limitation, particularly at lower frequencies. This program initially focused on developing a 402 MHz IOT; however, the DOE requirement for this device was terminated during the program. The SBIR effort was refocused on improving the IOT design codes to more accurately simulate the time dependent behavior of the input cavity, electron gun, output cavity, and collector. Significant improvement was achieved in modeling capability and simulation accuracy.

  20. High average power coherent vuv generation at 10 MHz repetition frequency by intracavity high harmonic generation.

    PubMed

    Ozawa, Akira; Zhao, Zhigang; Kuwata-Gonokami, Makoto; Kobayashi, Yohei

    2015-06-15

    Intracavity high harmonic generation was utilized to generate high average-power coherent radiation at vacuum ultraviolet (vuv) wavelengths. A ytterbium-doped fiber-laser based master-oscillator power-amplifier (MOPA) system with a 10 MHz repetition frequency was developed and used as a driving laser for an external cavity. A series of odd-order harmonic radiations was generated extending down to ∼ 30 nm (41 eV in photon energy). The 7th harmonic radiation generated was centered at 149 nm and had an average output power of up to 0.5 mW. In this way, we developed a sub-mW coherent vuv-laser with a 10 MHz repetition frequency, which, if used as an excitation laser source for photo-electron spectroscopy, could improve the signal count-rate without deterioration of the spectral-resolution caused by space-charge effects.

  1. Statistical characterization of the dynamic human body communication channel at 45 MHz.

    PubMed

    Nie, Zedong; Ma, Jingjing; Chen, Hong; Wang, Lei

    2013-01-01

    The dynamic human body communication (HBC) propagation channel at 45 MHz was statistical characterized in this paper. A large amount of measurement data has been gathered in practical environment with real activities -treadmill running at different speeds in a lab room. The received power between two lower legs was acquired from three volunteers, with more than 60,000 snap shot of data in total. The statistical analyses confirmed that the HBC propagation channel at 45 MHz followed the Gamma and Lognormal distributions at the slower (2 km/h and 4 km/h) and faster (6 km/h and 8 km/h) running activities, respectively. The channel is insensitive to body motion with the maximum average fade duration is 0.0413 s and the most averaging bad channel duration time being less than 60 ms with the percentage of the bad channel duration time being less than 4.35%.

  2. Conceptual design of the 26. 7 MHz RF system for RHIC

    SciTech Connect

    Rose, J.; Deng, D.P.; McKenzie-Wilson, R.; Pirkl, W.; Ratti, A.

    1993-01-01

    The 26.7 MHz (harmonic No. h=342) RF system will be used to capture the injected bunched beam from the AGS and accelerate it to a kinetic energy of up to 250 GeV for protons; 100 GeV/u for gold ions. All ions except protons cross transition, and are finally transferred to a storage RF system working at 196 MHz. Each RHIC ring will be provided with two single-ended capacitively loaded quarter-wave cavities; each of these can be dynamically tuned by 100 kHz to compensate for the change in speed of the beam, and can deliver at least 200 kV voltage. A 100 kW tetrode amplifier with local RF feedback is directly coupled to the cavity to minimize phase delay. Prototypes of cavity and amplifier have been built and first test results are presented.

  3. Conceptual design of the 26.7 MHz RF system for RHIC

    SciTech Connect

    Rose, J.; Deng, D.P.; McKenzie-Wilson, R.; Pirkl, W.; Ratti, A.

    1993-06-01

    The 26.7 MHz (harmonic No. h=342) RF system will be used to capture the injected bunched beam from the AGS and accelerate it to a kinetic energy of up to 250 GeV for protons; 100 GeV/u for gold ions. All ions except protons cross transition, and are finally transferred to a storage RF system working at 196 MHz. Each RHIC ring will be provided with two single-ended capacitively loaded quarter-wave cavities; each of these can be dynamically tuned by 100 kHz to compensate for the change in speed of the beam, and can deliver at least 200 kV voltage. A 100 kW tetrode amplifier with local RF feedback is directly coupled to the cavity to minimize phase delay. Prototypes of cavity and amplifier have been built and first test results are presented.

  4. The brightness temperature of Venus and the absolute flux-density scale at 608 MHz.

    NASA Technical Reports Server (NTRS)

    Muhleman, D. O.; Berge, G. L.; Orton, G. S.

    1973-01-01

    The disk temperature of Venus was measured at 608 MHz near the inferior conjunction of 1972, and a value of 498 plus or minus 33 K was obtained using a nominal CKL flux-density scale. The result is consistent with earlier measurements, but has a much smaller uncertainty. Our theoretical model prediction is larger by a factor of 1.21 plus or minus 0.09. This discrepancy has been noticed previously for frequencies below 1400 MHz, but was generally disregarded because of the large observational uncertainties. No way could be found to change the model to produce agreement without causing a conflict with well-established properties of Venus. Thus it is suggested that the flux-density scale may require an upward revision, at least near this frequency, in excess of what has previously been considered likely.

  5. Dark Current and X Ray Measurements of an 805 MHz Pillbox Cavity

    SciTech Connect

    J. Norem; P. Gruber; A. Bross; S. Geer; A. Moretti; Z Qian; D. M. Kaplan; Y. Torun; R. Rimmer; Derun Li; M. Zisman

    2003-05-01

    The muon cooling systems proposed for neutrino factories require low frequency (201 MHz) RF cavities with Be windows, at high gradient (Eacc {approx} 16 MV/m), in strong solenoidal magnetic field ({approx} 5 T). For the proposed Muon Ionization Cooling Experiment (MICE) [1], an experimental demonstration of cooling, we have an additional constraint that we must operate sensitive particle detectors very close to the RF cavities, which produce backgrounds from dark currents and x rays. To understand the processes involved in cavity conditioning and operation near particle detectors, we have constructed a test facility at Lab G of Fermilab, where a 5 Tesla superconducting solenoid, a 14 MW peak power klystron and a pillbox test cavity at 805 MHz are available. We present measurements of dark currents, x rays and surface structure from the pillbox cavity, with both copper and beryllium endplates, and discuss the interaction between surface structure and radiation backgrounds produced.

  6. Measurement of electrodynamics characteristics of higher order modes for harmonic cavity at 2400 MHz

    NASA Astrophysics Data System (ADS)

    Shashkov, Ya V.; Sobenin, N. P.; Gusarova, M. A.; Lalayan, M. V.; Bazyl, D. S.; Donetskiy, R. V.; Orlov, A. I.; Zobov, M. M.; Zavadtsev, A. A.

    2016-09-01

    In the frameworks of the High Luminosity Large Hadron Collider (HL-LHC) upgrade program an application of additional superconducting harmonic cavities operating at 800 MHz is currently under discussion. As a possible candidate, an assembly of two cavities with grooved beam pipes connected by a drift tube and housed in a common cryomodule, was proposed. In this article we discuss measurements of loaded Q-factors of higher order modes (HOM) performed on a scaled aluminium single cell cavity prototype with the fundamental frequency of 2400 MHz and on an array of two such cavities connected by a narrow beam pipe. The measurements were performed for the system with and without the matching load in the drift tube..

  7. Acoustic speed and attenuation coefficient in sheep aorta measured at 5-9 MHz.

    PubMed

    Fraser, Katharine H; Poepping, Tamie L; McNeilly, Alan; Megson, Ian L; Hoskins, Peter R

    2006-06-01

    B-mode ultrasound (US) images from blood vessels in vivo differ significantly from vascular flow phantom images. Phantoms with acoustic properties more closely matched to those of in vivo arteries may give better images. A method was developed for measuring the speed and attenuation coefficient of US over the range 5 to 9 MHz in samples of sheep aorta using a pulse-echo technique. The times-of-flight method was used with envelope functions to identify the reference points. The method was tested with samples of tissue-mimicking material of known acoustic properties. The tissue samples were stored in Krebs physiologic buffer solution and measured over a range of temperatures. At 37 degrees C, the acoustic speed and attenuation coefficient as a function of frequency in MHz were 1600 +/- 50 ms(-1) and 1.5 +/- 4f(0.94 +/- 1.3) dB cm(-1), respectively.

  8. High-Frequency (>50 MHz) Medical Ultrasound Linear Arrays Fabricated From Micromachined Bulk PZT Materials

    PubMed Central

    Liu, Changgeng; Zhou, Qifa; Djuth, Frank T.; Shung, K. Kirk

    2012-01-01

    This paper describes the development and characterization of a high-frequency (65-MHz) ultrasound transducer linear array. The array was built from bulk PZT which was etched using an optimized chlorine-based plasma dry-etching process. The median etch rate of 8 μm/h yielded a good profile (wall) angle (>83°) and a reasonable processing time for etch depths up to 40 μm (which corresponds to a 50-MHz transducer). A backing layer with an acoustic impedance of 6 MRayl and a front-end polymer matching layer yielded a transducer bandwidth of 40%. The major parameters of the transducer have been characterized. The two-way insertion loss and crosstalk between adjacent channels at the center frequency are 26.5 and −25 dB, respectively. PMID:24626041

  9. Comparison of higher order modes damping techniques for 800 MHz single cell superconducting cavities

    NASA Astrophysics Data System (ADS)

    Shashkov, Ya. V.; Sobenin, N. P.; Petrushina, I. I.; Zobov, M. M.

    2014-12-01

    At present, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOMs) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOMs damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOMs damping is analyzed. The problems of a multipacting discharge in the considered structures are discussed and the operating frequency detuning due to the Lorentz force is evaluated.

  10. Radio wave emitted by an extensive air showers in 10KHz to 1MHz region

    NASA Technical Reports Server (NTRS)

    Nichimura, J.

    1985-01-01

    The importance of radio waves in a frequency range of less than 1MHz in an EAS shower is discussed. Estimates of radio intensities at 10KHz, 100KHz and 1MHz in EAS showers made on the basis of the Kahn-Lerche theory. Negative charge excess in a shower is the main source of low frequency radio emission, in spite of the importance of the contribution of transverse current in the geomagnetic field in a higher frequency range. An estimate is also made for radio intensity produced when the shower hits the ground. The contribution of this process seems to be important at a large distance, i.e., beyond 1km from the shower axis.

  11. Circular polarization in 1612 MHz OH maser emission from OH/IR stars

    NASA Technical Reports Server (NTRS)

    Zell, Philip; Fix, John D.

    1991-01-01

    In order to study the incidence of circular polarization in the 1612 MHz OH emission from envelopes of OH/IR stars, the Arecibo radio telescope was used to obtain high-resolution, high signal-to-noise 1612 MHz spectra in both circular polarizations for several OH/IR stars. The method of Troland and Heiles (1982) was used to estimate the intensities of magnetic fields in the envelopes. The fields appear to have complex structures, and intensities on the order of 1-100 microG. The spectra are weakly polarized, probably as a result of weakly polarized emission from individual emitting elements. Integration over the Stokes parameter V yields nonzero results for three of the stars, suggesting that another polarizing mechanism (in addition to simple Zeeman splittings) is at work.

  12. Effects of microwaves (900 MHz) on peroxidase systems: A comparison between lactoperoxidase and horseradish peroxidase.

    PubMed

    Barteri, Mario; De Carolis, Roberta; Marinelli, Fiorenzo; Tomassetti, Goliardo; Montemiglio, Linda Celeste

    2016-01-01

    This work shows the effects of exposure to an electromagnetic field at 900 MHz on the catalytic activity of the enzymes lactoperoxidase (LPO) and horseradish peroxidase (HRP). Experimental evidence that irradiation causes conformational changes of the active sites and influences the formation and stability of the intermediate free radicals is documented by measurements of enzyme kinetics, circular dichroism spectroscopy (CD) and cyclic voltammetry.

  13. A 7.5 MHz Dual-Layer Transducer Array for 3-D Rectilinear Imaging

    PubMed Central

    Chen, Yuling; Nguyen, Man; Yen, Jesse T.

    2011-01-01

    The difficulties associated with fabrication and interconnection have limited the development of 2-D ultrasound transducer arrays with a large number of elements (>5000). In previous work, we described a 5 MHz center frequency PZT-P[VDF-TrFE] dual-layer transducer, which used 2 perpendicular 1-D arrays for 3-D rectilinear imaging. This design substantially reduces the channel count as well as fabrication complexity, which makes 3-D imaging more realizable. Higher frequencies (>5MHz) are more commonly used in clinical for imaging targets near transducers such as the breast, carotid, and musculoskeletal. In this paper, we present a 7.5 MHz dual-layer transducer array for 3-D rectilinear imaging. A modified acoustic stack model was designed and fabricated. PZT elements were sub-diced to eliminate lateral coupling. This sub-dicing process made the PZT into a 2–2 composite material, which could help improve transducer sensitivity and bandwidth. Full synthetic aperture 3-D data sets were acquired by interfacing the transducer with a Verasonics data acquisition system (VDAS). Offline 3-D beamforming was then performed to obtain volumes of a multi-wire phantom and a cyst phantom. The generalized coherence factor (GCF) was applied to improve the contrast of cyst images. The measured −6 dB fractional bandwidth of the transducer was 71% with a center frequency of 7.5 MHz. The measured lateral beamwidths were 0.521 mm and 0.482 mm in azimuth and elevation respectively, compared with a simulated beamwidth of 0.43 mm. PMID:21842584

  14. Improved measurement of the spectral index of the diffuse radio background between 90 and 190 MHz

    NASA Astrophysics Data System (ADS)

    Mozdzen, T. J.; Bowman, J. D.; Monsalve, R. A.; Rogers, A. E. E.

    2017-02-01

    We report absolutely calibrated measurements of diffuse radio emission between 90 and 190 MHz from the Experiment to Detect the Global EoR Signature (EDGES). EDGES employs a wide beam zenith-pointing dipole antenna centred on a declination of -26.7°. We measure the sky brightness temperature as a function of frequency averaged over the EDGES beam from 211 nights of data acquired from 2015 July to 2016 March. We derive the spectral index, β, as a function of local sidereal time (LST) and find -2.60 > β > -2.62 ± 0.02 between 0 and 12 h LST. When the Galactic Centre is in the sky, the spectral index flattens, reaching β = -2.50 ± 0.02 at 17.7 h. The EDGES instrument is shown to be very stable throughout the observations with night-to-night reproducibility of σβ < 0.003. Including systematic uncertainty, the overall uncertainty of β is 0.02 across all LST bins. These results improve on the earlier findings of Rogers & Bowman by reducing the spectral index uncertainty from 0.10 to 0.02 while considering more extensive sources of errors. We compare our measurements with spectral index simulations derived from the Global Sky Model (GSM) of de Oliveira-Costa et al. and with fits between the Guzmán et al. 45 MHz and Haslam et al. 408 MHz maps. We find good agreement at the transit of the Galactic Centre. Away from transit, the GSM tends to overpredict (GSM less negative) by 0.05 < Δβ = βGSM - βEDGES < 0.12, while the 45-408 MHz fits tend to overpredict by Δβ < 0.05.

  15. 47 CFR 90.357 - Frequencies for LMS systems in the 902-928 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... authorized on the following LMS sub-bands: LMS sub-band Forward link 1 904.000-909.750 MHz 927.750-928.000... links for LMS systems may also be contained within the LMS sub-band. However, the maximum allowable power in these sub-bands is 30 Watts ERP in accordance with § 90.205(l). 2 The frequency band...

  16. Dielectric properties of beef, beef liver, chicken and salmon at frequencies from 100 to 2500 MHz.

    PubMed

    Tran, V N; Stuchly, S S

    1987-01-01

    The dielectric properties of uncooked beef, beef liver, chicken and salmon meat were measured at frequencies between 100 and 2500 MHz and at selected temperatures between 1.2 degrees C and 65 degrees C. Experimental method and the sample holder are briefly described. The results for the dielectric constant and the dielectric loss factor are presented as a function of frequency at selected temperatures and show a trend consistent with theoretical expectation.

  17. Exposure to 1800 MHz radiofrequency radiation impairs neurite outgrowth of embryonic neural stem cells.

    PubMed

    Chen, Chunhai; Ma, Qinlong; Liu, Chuan; Deng, Ping; Zhu, Gang; Zhang, Lei; He, Mindi; Lu, Yonghui; Duan, Weixia; Pei, Liping; Li, Min; Yu, Zhengping; Zhou, Zhou

    2014-05-29

    A radiofrequency electromagnetic field (RF-EMF) of 1800 MHz is widely used in mobile communications. However, the effects of RF-EMFs on cell biology are unclear. Embryonic neural stem cells (eNSCs) play a critical role in brain development. Thus, detecting the effects of RF-EMF on eNSCs is important for exploring the effects of RF-EMF on brain development. Here, we exposed eNSCs to 1800 MHz RF-EMF at specific absorption rate (SAR) values of 1, 2, and 4 W/kg for 1, 2, and 3 days. We found that 1800 MHz RF-EMF exposure did not influence eNSC apoptosis, proliferation, cell cycle or the mRNA expressions of related genes. RF-EMF exposure also did not alter the ratio of eNSC differentiated neurons and astrocytes. However, neurite outgrowth of eNSC differentiated neurons was inhibited after 4 W/kg RF-EMF exposure for 3 days. Additionally, the mRNA and protein expression of the proneural genes Ngn1 and NeuroD, which are crucial for neurite outgrowth, were decreased after RF-EMF exposure. The expression of their inhibitor Hes1 was upregulated by RF-EMF exposure. These results together suggested that 1800 MHz RF-EMF exposure impairs neurite outgrowth of eNSCs. More attention should be given to the potential adverse effects of RF-EMF exposure on brain development.

  18. Effect of 19 MHz RF Radiation on Neurotransmitters in Mouse Brain.

    DTIC Science & Technology

    Mice were exposed to 19 MHz radiofrequency radiation and then euthanized by microwave-heating brain inactivation. Brain levels of 5-hydroxyindole acetic acid (5HIAA), homovanillic acid (HVA), serotonin (5HT), norepinephrine (NE), and dopamine (DA) were not altered by this radiation. Brain concentration of 5HIAA, 5 HT, NE, and DA was higher when control animals were euthanized by microwave inactivation than by cervical dislocation.

  19. Higher Order Mode Damper Study of the 56 MHz SRF Cavity

    SciTech Connect

    Choi,E.; Hahn, H.

    2008-08-01

    This report summarizes the study on the higher order mode (HOM) damper for the 56 MHz SRF cavity. The Q factors and frequencies of the HOMs with the HOM damper are measured and compared to the simulation. The high pass filter prototype for rejecting the fundamental mode is designed and tested. The filter measurement is also compared to the simulation. Based on the measurement, a new location of the HOM damper is chosen.

  20. Optimizing of the higher order mode dampers in the 56MHz SRF cavity

    SciTech Connect

    Wu, Q.; Ben-Zvi, I.

    2010-01-27

    Earlier, we reported that a 56 MHz cavity was designed for a luminosity upgrade of the RHIC, and presented the requirements for Higher Order Mode (HOM) damping, the design of the HOM dampers, along with measurements and simulations of the HOM dampers. In this report, we describe our optimization of the dampers performance, and the modifications we made to their original design. We also optimized the number of the HOM dampers, and tested different configurations of locations for them.

  1. 700MHz Spectrum Requirements for Canadian Public Safety Interoperable Mobile Broadband Data Communications

    DTIC Science & Technology

    2011-02-28

    time frame. The data demand for recurring emergency situations was modeled through an interactive process with active participation from Canadian...bande qui permettra aux divers organismes de sécurité publique de mieux planifier , coordonner et exécuter leurs mandats, tant dans le cadre de leurs...plan for 700MHz spectrum 2 Figure 2.1: Process to develop the Data Demand Model 4 Figure

  2. High power circulator for the 433.3 MHz proton linac

    NASA Astrophysics Data System (ADS)

    Shirai, T.; Inoue, M.; Iwashita, Y.; Noda, A.; Takekoshi, H.; Tsuruoka, S.

    1992-10-01

    A 433.3 MHz T-junction waveguide circulator with a dummy-load was constructed to isolate the klystron and a linac cavity at the high rf power level of 1 MW. The isolation is -34.9 dB at a low duty factor and it decreases to -23.8 dB at a high duty factor (1%), which shows enough performance for our linac operation.

  3. Phase-locked 10 MHz reference signal for frequency domain time-resolved fluorescence measurements

    NASA Astrophysics Data System (ADS)

    Smith, Trevor A.; Bird, Damian K.; Nuske, John W.

    2007-05-01

    A complete electronic system that is suitable for use in megahertz frequency domain time-resolved fluorescence instruments based on mode-locked lasers is described. The circuit produces a 10MHz signal, phase locked to the mode-locked laser pulse frequency, which is required by many commercial frequency synthesizers as the external reference signal. This device is particularly useful in conjunction with ultrafast gated intensified charge coupled device cameras capable of being frequency modulated for time-resolved fluorescence imaging.

  4. 7.5 MHz dual-layer transducer array for 3-D rectilinear imaging.

    PubMed

    Chen, Yuling; Nguyen, Man; Yen, Jesse T

    2011-07-01

    The difficulties associated with fabrication and interconnection have limited the development of 2-D ultrasound transducer arrays with a large number ofelements (>5000). In previous work, we described a 5 MHz center frequency PZT-P[VDF-TrFE] dual-layer transducer that used two perpendicular 1-D arrays for 3-D rectilinear imaging. This design substantially reduces the channel count as well as fabrication complexity, which makes 3-D imaging more realizable. Higher frequencies (>5 MHz) are more commonly used in clinical applications or imaging targets near transducers, such as the breast, carotid and musculoskeletal tissue. In this paper, we present a 7.5 MHz dual-layer transducer array for 3-D rectilinear imaging. A modified acoustic stack model was designed and fabricated. PZT elements were sub-diced to eliminate lateral coupling. This sub-dicing process made the PZT into a 2-2 composite material, which could help improve transducer sensitivity and bandwidth. Full synthetic-aperture 3-D data sets were acquired by interfacing the transducer with a Verasonics data-acquisition system (VDAS). Offline 3-D beamforming was then performed to obtain volumes of a multiwire phantom and a cyst phantom. The generalized coherence factor (GCF) was applied to improve the contrast of cyst images. The measured -6 dB fractional bandwidth of the transducer was 71% with a center frequency of 7.5 MHz. The measured lateral beamwidths were 0.521 mm and 0.482 mm in azimuth and elevation, respectively, compared with a simulated beamwidth of 0.43 mm.

  5. Background-free broadband CARS spectroscopy from a 1-MHz ytterbium laser.

    PubMed

    Kumar, Vikas; Osellame, R; Ramponi, R; Cerullo, G; Marangoni, M

    2011-08-01

    We introduce a novel configuration for broadband, time-resolved CARS spectroscopy/microscopy in which pump, Stokes and probe pulses are all derived from a single femtosecond Yb:KYW laser. The 1-MHz repetition rate of the system allows very intense CARS signals to be obtained over short acquisition times, while a delayed probe pulse ensures an efficient non-resonant background suppression.

  6. [Influence of 900 MHz frequency electromagnetic radiation on some blood indices].

    PubMed

    Badzhinian, S A; Malakian, M G; Egiazarian, D E; Agdzhoian, R L; Abramian, L E

    2013-01-01

    The paper represents the results of research of some functional indices of blood plasma and erythrocytes in rats obtained on days 1 and 5 after exposure of the organism to low intensive electromagnetic irradiation (EMI) with 900 MHz frequency using the following two irradiation schemes: single 2 h/1 day and fractional 0.5 h/4 days. According to the data obtained, a significant increase of lipid peroxidation (LPO) intensity is registered in animal erythrocyte membranes after the influence of 900 MHz frequency EMI irrespective of the scheme applied. Inhibition of the activity of low-molecular non-enzymatic water-soluble blood antioxidants and enhancement of blood plasma LPO processes is observed on the background of a single prolonged exposure. Stimulation of the antioxidant activity with an abrupt decrease in the blood LPO activity takes place after exposure to fractional irradiation. Single long-lasting exposure, rather than intermittent shortterm exposure to 900 MHz frequency EMI facilitates the appearance of shifts in the activity of Ca(2+)-dependent K(+)-channels of erythrocytes and hyperpolarization of erythrocytes membranes.

  7. Oxidative and genotoxic effects of 900 MHz electromagnetic fields in the earthworm Eisenia fetida.

    PubMed

    Tkalec, Mirta; Stambuk, Anamaria; Srut, Maja; Malarić, Krešimir; Klobučar, Göran I V

    2013-04-01

    Accumulating evidence suggests that exposure to radiofrequency electromagnetic field (RF-EMF) can have various biological effects. In this study the oxidative and genotoxic effects were investigated in earthworms Eisenia fetida exposed in vivo to RF-EMF at the mobile phone frequency (900 MHz). Earthworms were exposed to the homogeneous RF-EMF at field levels of 10, 23, 41 and 120 V m(-1) for a period of 2h using a Gigahertz Transversal Electromagnetic (GTEM) cell. At the field level of 23 V m(-1) the effect of longer exposure (4h) and field modulation (80% AM 1 kHz sinusoidal) was investigated as well. All exposure treatments induced significant genotoxic effect in earthworms coelomocytes detected by the Comet assay, demonstrating DNA damaging capacity of 900 MHz electromagnetic radiation. Field modulation additionally increased the genotoxic effect. Moreover, our results indicated the induction of antioxidant stress response in terms of enhanced catalase and glutathione reductase activity as a result of the RF-EMF exposure, and demonstrated the generation of lipid and protein oxidative damage. Antioxidant responses and the potential of RF-EMF to induce damage to lipids, proteins and DNA differed depending on the field level applied, modulation of the field and duration of E. fetida exposure to 900 MHz electromagnetic radiation. Nature of detected DNA lesions and oxidative stress as the mechanism of action for the induction of DNA damage are discussed.

  8. Spreading dynamics of a partially wetting water film atop a MHz substrate vibration

    SciTech Connect

    Altshuler, Gennady; Manor, Ofer

    2015-10-15

    A MHz vibration, or an acoustic wave, propagating in a solid substrate may support the convective spreading of a liquid film. Previous studies uncovered this ability for fully wetting silicon oil films under the excitation of a MHz Rayleigh surface acoustic wave (SAW), propagating in a lithium niobate substrate. Partially wetting de-ionized water films, however, appeared immune to this spreading mechanism. Here, we use both theory and experiment to reconsider this situation and show partially wetting water films may spread under the influence of a propagating MHz vibration. We demonstrate distinct capillary and convective (vibrational/acoustic) spreading regimes that are governed by a balance between convective and capillary mechanisms, manifested in the non-dimensional number θ{sup 3}/We, where θ is the three phase contact angle of the liquid with the solid substrate and We ≡ ρU{sup 2}H/γ; ρ, γ, H, and U are the liquid density, liquid/vapour surface tension, characteristic film thickness, and the characteristic velocity amplitude of the propagating vibration on the solid surface, respectively. Our main finding is that the vibration will support a continuous spreading motion of the liquid film out of a large reservoir if the convective mechanism prevails (θ{sup 3}/We < 1); otherwise (θ{sup 3}/We > 1), the dynamics of the film is governed by the capillary mechanism.

  9. Chronic exposure to GSM 1800-MHz microwaves reduces excitatory synaptic activity in cultured hippocampal neurons.

    PubMed

    Xu, Shujun; Ning, Wei; Xu, Zhengping; Zhou, Suya; Chiang, Huai; Luo, Jianhong

    2006-05-08

    The world wide proliferation of mobile phones raises the concern about the health effects of 1800-MHz microwaves on the brain. The present study assesses the effects of microwave exposure on the function of cultured hippocampal neurons of rats using whole cell patch-clamp analysis combined with immunocytochemistry. We showed that chronic exposure (15 min per day for 8 days) to Global System for Mobile Communication (GSM) 1800-MHz microwaves at specific absorption rate (SAR) of 2.4 W/kg induced a selective decrease in the amplitude of alpha-amino-3-hydroxy-5-methyl-4-soxazole propionic acid (AMPA) miniature excitatory postsynaptic currents (mEPSCs), whereas the frequency of AMPA mEPSCs and the amplitude of N-methyl-D-aspartate (NMDA) mEPSCs did not change. Furthermore, the GSM microwave treatment decreased the expression of postsynaptic density 95 (PSD95) in cultured neurons. Our results indicated that 2.4 W/kg GSM 1800-MHz microwaves may reduce excitatory synaptic activity and the number of excitatory synapses in cultured rat hippocampal neurons.

  10. 80-MHz intravascular ultrasound transducer using PMN-PT free-standing film.

    PubMed

    Li, Xiang; Wu, Wei; Chung, Youngsoo; Shih, Wan Y; Shih, Wei-Heng; Zhou, Qifa; Shung, K Kirk

    2011-11-01

    [Pb(Mg(1/3)Nb(2/3))O(3)](0.63)[PbTiO(3)](0.37) (PMN-PT) free-standing film of comparable piezoelectric properties to bulk material with thickness of 30 μm has been fabricated using a modified precursor coating approach. At 1 kHz, the dielectric permittivity and loss were 4364 and 0.033, respectively. The remnant polarization and coercive field were 28 μC/cm(2) and 18.43 kV/cm. The electromechanical coupling coefficient k(t) was measured to be 0.55, which was close to that of bulk PMN-PT single-crystal material. Based on this film, high-frequency (82 MHz) miniature ultrasonic transducers were fabricated with 65% bandwidth and 23 dB insertion loss. Axial and lateral resolutions were determined to be as high as 35 and 176 μm. In vitro intravascular imaging on healthy rabbit aorta was performed using the thin film transducers. In comparison with a 35-MHz IVUS transducer, the 80-MHz transducer showed superior resolution and contrast with satisfactory penetration depth. The imaging results suggest that PMN-PT free-standing thin film technology is a feasible and efficient way to fabricate very-high-frequency ultrasonic transducers.

  11. Experimental study of a very high frequency, 162 MHz, segmented electrode, capacitively coupled plasma discharge

    NASA Astrophysics Data System (ADS)

    Sirse, Nishant; Harvey, Cleo; Gaman, Cezar; Ellingboe, Bert

    2016-09-01

    Radio-frequency capacitively coupled plasma (CCP) discharge operating at a very high frequency, 30-300 MHz, offers many advantages over standard 13.56 MHz CCP. However, there is a limited flexibility on the choice of driving frequency and substrate size due to plasma non-uniformity caused by the standing wave effect and edge effect. To overcome this issue segmented electrode CCP's are proposed and researched. Despite its numerous advantages the power coupling mechanism and plasma chemistry in this type of discharge are not fully understood due to lack of experimental data. In this paper, we present the experimental study of a segmented electrode, 3x4 tile array (10x10 cm square tile with 1 cm tile-to-tile separation), CCP discharge driven at 162 MHz. We measured plasma uniformity and gas temperature using hairpin probe and optical emission spectroscopy respectively. A homemade RF compensated Langmuir probe is employed to measure the Electron Energy Distribution Function (EEDF) by second harmonic technique. Energy resolved quadrupole mass spectrometer is utilized to measure the ion energy distribution. Discharge/plasma properties are investigated for several operating conditions and for power coupling mode in both washer board and checker board configuration. The experimental results show that the uniform plasma density can be maintained over a large area along with highly non-equilibrium condition to produce unique gas phase plasma chemistry.

  12. Suppression of the 1 MHz beam current modulation in the LEDA/CRITS proton source

    SciTech Connect

    Balleyguier, P.; Sherman, J.; Zaugg, T.

    1998-12-01

    Earlier operation of a microwave proton source exhibited an approximate 1-MHz modulation in the beam current. This oscillation could cause instabilities at higher energies in the linac, as the low-level RF control for linac operation rolls off at 200 kHz. Tests on a dummy load show the modulation is created by the magnetron itself: at a typical power level required for the source operation (680W), the 1-MHz sideband level was as high as {minus}4 dB from carrier. Since the magnetron exhibited better behavior at higher levels, a RF power attenuator is inserted to force the magnetron to run at a 50% higher power level for the same final power in the load. This attenuator is made of two antennas plunged in the waveguide and connected to dummy loads by a coaxial line. As the antenna are separated by a quarter of the guided wavelength, mismatching effects approximately cancel each other. The antenna length is experimentally adjusted to obtain the {minus}1.8 dB attenuation required. Magnetron operation at the higher power level gives a beam current spectrum free of the 1-MHz modulation, showing the coherent beam noise is not generated by plasma chamber phenomena.

  13. Project Phoenix: SETI Observations from 1200 to 1750 MHz with the Upgraded Arecibo Telescope

    NASA Astrophysics Data System (ADS)

    Backus, P. R.; Project Phoenix Team

    2001-05-01

    Project Phoenix, the privately funded continuation of NASA's Targeted Search SETI Program, has taken advantage of the wide frequency coverage made possible by the upgraded Arecibo Telescope. Our goal is to search for evidence of narrowband extraterrestrial radio signals from nearby stars in the microwave portion of the spectrum. The signal detection system processes a 20 MHz bandwidth with 28.74 million 1 Hz wide channels in each of two circular polarizations. The system is sensitive to signals that are continuously present, or pulsed regularly, even if their frequencies drift by up to about 1 Hz per second. A database of terrestrial signals found in the previous week is used to match against detections for each observation. Candidate signals, i.e., those not in the database, are checked immediately with a "pseudo-interferometric" observation between Arecibo and the 76 meter Lovell Telescope at the Jodrell Bank Observatory. Since 1998 October, we have conducted approximately 8 weeks of observations at L-Band, 1200 to 1750 MHz. Approximately 150 MHz of that range is too heavily occupied by terrestrial signals for effective observing. This paper will describe the results of the observations and the terrestrial signal environment in this frequency range.

  14. Project Phoenix: SETI Observations from 1200 to 1750 MHz with the Upgraded Arecibo Telescope

    NASA Astrophysics Data System (ADS)

    Backus, P. R.; Project Phoenix Team

    2002-12-01

    Project Phoenix, the privately funded continuation of NASA's Targeted Search SETI Program, has taken advantage of the wide frequency coverage made possible by the upgraded Arecibo Telescope. Our goal is to search for evidence of narrowband extraterrestrial radio signals from nearby stars in the microwave portion of the spectrum. The signal detection system processes a 20-MHz bandwidth with 1-Hz wide channels in each of two circular polarizations. The system is sensitive to signals that are continuously present, or pulsed regularly, even if their frequencies drift by up to about 1 Hz per second. A database of terrestrial signals found in the previous week is used to match against detections for each observation. Candidate signals, i.e., those not in the database, are checked immediately with a ``pseudo-interferometric'' observation between Arecibo and the 76-m Lovell Telescope at the Jodrell Bank Observatory. Since 1998 October, we have conducted approximately 8 weeks of observations at L-Band, 1200 to 1750 MHz. Approximately 180 MHz of that range is too heavily occupied by terrestrial signals for effective observing.

  15. Foregrounds for redshifted 21-cm studies of reionization: Giant Meter Wave Radio Telescope 153-MHz observations

    NASA Astrophysics Data System (ADS)

    Ali, Sk. Saiyad; Bharadwaj, Somnath; Chengalur, Jayaram N.

    2008-04-01

    Foreground subtraction is the biggest challenge for future redshifted 21-cm observations to probe reionization. We use a short Giant Meter Wave Radio Telescope (GMRT) observation at 153MHz to characterize the statistical properties of the background radiation across ~1° to subarcmin angular scales, and across a frequency band of 5MHz with 62.5kHz resolution. The statistic we use is the visibility correlation function, or equivalently the angular power spectrum Cl. We present the results obtained from using relatively unsophisticated, conventional data calibration procedures. We find that even fairly simple-minded calibration allows one to estimate the visibility correlation function at a given frequency V2(U, 0). From our observations, we find that V2(U, 0) is consistent with foreground model predictions at all angular scales except the largest ones probed by our observations where the model predictions are somewhat in excess. On the other hand, the visibility correlation between different frequencies κ(U, Δν) seems to be much more sensitive to calibration errors. We find a rapid decline in κ(U, Δν), in contrast with the prediction of less than 1 per cent variation across 2.5MHz. In this case, however, it seems likely that a substantial part of the discrepancy may be due to limitations of data reduction procedures.

  16. An analog memory integrated circuit for waveform acquisition up to 900 MHz

    SciTech Connect

    Haller, G.M.; Wooley, B.A.

    1993-12-01

    The design and implementation of a switched-capacitor memory suitable for capturing high-speed analog waveforms is described. Highlights of the presented circuit are a 900 MHz sampling frequency (generated on chip), input signal independent cell pedestals and sampling instances, and cell gains that are insensitive to component sizes. A two-channel version of the memory with 32 cells for each channel has been integrated in a 2-{mu}m complementary metal oxide semiconductor (CMOS) process with poly-to-poly capacitors. The measured rms cel pedestal variation in a channel after baseline subtraction is less than 0.3 mV across the full input signal range. The cell-to-cell gain matching is better than 0.01% rms, and the nonlinearity is less than 0.03% for a 2.5-V input range. The dynamic range of the memory exceeds 13 bits, and the peak signal-to-(noise+distortion) ratio for a 21.4 MHz sine wave sampled at 900 MHz is 59 dB.

  17. Sustaining GHz oscillation of carbon nanotube based oscillators via a MHz frequency excitation

    NASA Astrophysics Data System (ADS)

    Motevalli, Benyamin; Taherifar, Neda; Zhe Liu, Jefferson

    2016-05-01

    There have been intensive studies to investigate the properties of gigahertz nano-oscillators based on multi-walled carbon nanotubes (MWCNTs). Many of these studies, however, revealed that the unique telescopic translational oscillations in such devices would damp quickly due to various energy dissipation mechanisms. This challenge remains the primary obstacle against its practical applications. Herein, we propose a design concept in which a GHz oscillation could be re-excited by a MHz mechanical motion. This design involves a triple-walled CNT, in which sliding of the longer inner tube at a MHz frequency can re-excite and sustain a GHz oscillation of the shorter middle tube. Our molecular dynamics (MD) simulations prove this design concept at ˜10 nm scale. A mathematical model is developed to explore the feasibility at a larger size scale. As an example, in an oscillatory system with the CNT’s length above 100 nm, the high oscillatory frequency range of 1.8-3.3 GHz could be excited by moving the inner tube at a much lower frequency of 53.4 MHz. This design concept together with the mechanical model could energize the development of GHz nano-oscillators in miniaturized electro-mechanical devices.

  18. Immunotropic influence of 900 MHz microwave GSM signal on human blood immune cells activated in vitro.

    PubMed

    Stankiewicz, Wanda; Dabrowski, Marek P; Kubacki, Roman; Sobiczewska, Elzbieta; Szmigielski, Stanisław

    2006-01-01

    In an earlier study we reported that G(o) phase peripheral blood mononulclear cells (PBMC) exposed to low-level (SAR = 0.18 W/kg) pulse-modulated 1300 MHz microwaves and subsequently cultured, demonstrate changed immune activity (Dabrowski et al., 2003). We investigated whether cultured immune cells induced into the active phases of cell cycle (G(1), S) and then exposed to microwaves will also be sensitive to electromagnetic field. An anechoic chamber of our design containing a microplate with cultured cells and an antenna emitting microwaves (900 MHz simulated GSM signal, 27 V/m, SAR 0.024 W/kg) was placed inside the ASSAB incubator. The microcultures of PBMC exposed to microwaves demonstrated significantly higher response to mitogens and higher immunogenic activity of monocytes (LM index) than control cultures. LM index, described in detail elsewhere (Dabrowski et al., 2001), represents the monokine influence on lymphocyte mitogenic response. The results suggest that immune activity of responding lymphocytes and monocytes can be additionally intensified by 900 MHz microwaves.

  19. Untersuchung der Störwirkung von LTE auf SRD Anwendungen bei 868 MHz

    NASA Astrophysics Data System (ADS)

    Welpot, M.; Wunderlich, S.; Gaspard, I.

    2014-11-01

    Moderne Hausautomatisierungssysteme, Alarmanlagen oder auch Funk-Zugangssysteme in Haus und Automobil setzen auf frei nutzbare Frequenzen in ISM/SRD-Bändern. Die rasante Zunahme an privaten und kommerziell genutzten Applikationen im SRD-Band bei 868 MHz und der Ausbau der LTE-Mobilfunknetze im Frequenzbereich unterhalb von 1 GHz ("Digital Dividend") wirft zunehmend die Frage nach der Funkverträglichkeit dieser Systeme untereinander auf. Während die SRD-Funkmodule auf eine geringe Sendeleistung von ~ +14 dBm beschränkt sind (Ralf and Thomas, 2009), beträgt die maximale LTE-Sendeleistung im Uplink nach (ETSI-Norm, 2011) +23 dBm. Zusammen mit der Einführung von LTE im Frequenzbereich unterhalb 1 GHz als DSL-Ersatz vor allem in ländlichen Gebieten, ergibt sich damit als mögliches Störszenario, dass durch die Aussendung des LTE-Endgerätes im Bereich von ca. 850 MHz die SRD-Funkverbindungen bei 868 MHz insbesondere dann gestört werden, wenn die Antennen beider Funksysteme räumlich nahe zueinander angeordnet sind und folglich nur eine geringe zusätzliche Entkopplung der Systeme bieten. In der vorliegenden Arbeit wird das LTE-Störpotential auf SRD-Empfänger praxisnah untersucht.

  20. Compact 400-Mhz Half-Wave Spoke Resonator Crab Cavitiy for the LHC Update

    SciTech Connect

    Li, Zenghai; Xiao, Liling; Ng, Cho; Markiewicz, Thomas; /SLAC

    2010-08-26

    Crab cavities are proposed for the LHC upgrade to improve the luminosity. There are two possible crab cavity installations for the LHC upgrade: the global scheme at Interaction Region (IR) 4 where the beam-beam separation is about 420-mm, and the local scheme at the IR5 where the beam-beam separation is only 194-mm. One of the design requirements as the result of a recent LHC-Crab cavity workshop is to develop a 400-MHz cavity design that can be utilized for either the global or local schemes at IR4 or IR5. Such a design would offer more flexibility for the final upgrade installation, as the final crabbing scheme is yet to be determined, and save R&D cost. The cavity size of such a design, however, is limited by the beam-beam separation at IR5 which can only accommodate a cavity with a horizontal size of about 145-mm, which is a design challenge for a 400-MHz cavity. To meet the new design requirements, we have developed a compact 400-MHz half-wave spoke resonator (HWSR) crab cavity that can fit into the tight spaces available at either IR4 or IR5. In this paper, we present the optimization of the HWSR cavity shape and the design of HOM, LOM, and SOM couplers for wakefield damping.

  1. Suppression of a 1 MHz Beam Current Modulation in a Microwave Proton Source

    NASA Astrophysics Data System (ADS)

    Balleyguier, Pascal; Sherman, Joseph; Zaugg, Thomas

    1998-04-01

    Earlier operation of a microwave proton source exhibited an approximate 1-MHz modulation in the beam current. This oscillation could cause instabilities at higher energies in the linac, as the low-level RF control for linac operation rolls off at 200 kHz. Tests on a dummy load show the modulation is created by the magnetron itself: at a typical power level required for the source operation (680W), the 1-MHz sideband level was as high as -4 dB from carrier. Since the magnetron exhibited better behavior at higher levels, a RF power attenuator is inserted to force the magnetron to run at a 50 per cent higher power level for the same final power in the load. This attenuator is made of two antennas plunged in the waveguide and connected to dummy loads by a coaxial line. As the antenna are separated by a quarter of the guided wavelength, mismatching effects approximately cancel each other. The antenna length is experimentally adjusted to obtain the -1.8 dB attenuation required. Magnetron operation at the higher power level gives a beam current spectrum free of the 1-MHz modulation, showing the coherent beam noise is not generated by plasma chamber phenomena.

  2. Digital cross-correlation at 250 MHz using high-performance FPGAs

    NASA Astrophysics Data System (ADS)

    von Herzen, Brian

    1998-07-01

    This paper describes a 250 MHz cross-correlator for radio astronomy built using field-programmable gate arrays (FPGA's). Experimental results indicate that CMOS FPGA's can operate reliably at 250 MHz. Long-term integration tests of up to 10(superscript 12) samples have been taken, demonstrating the correlator accuracy down to the limits of the testing apparatus. Recent estimates indicate that higher-performance FPGA's available early in 1998 can attain speeds of over 300 MHz using 20% fewer logic elements than previous designs. The FPGA correlator can be reconfigured for 2, 3, 4, or even 9 levels of sensitivity, permitting a tradeoff of the number of lags with the sensitivity desired. Although FPGA's have historically been more expensive than custom chips, starting this year FPGA correlators are actually less expensive than custom correlator chips. This cost reduction is due to the fact that FPGA's are standard components in the electronics industry and are produced in much higher volumes than custom correlators. As an example, a 1024-lag 4-level cross- correlator can be produced for an FPG chip cost of less than $80 in 1998. FPGA's continue to drop in price faster than custom devices because volumes continue to increase and FPGA architectures continue to improve. The demonstrated high performance of FPGA's coupled with their extreme flexibility, reconfigurability and lower cost make FPGA's ideally suited for the next generation of large correlator arrays.

  3. Development of lead-free single-element ultrahigh frequency (170-320MHz) ultrasonic transducers.

    PubMed

    Lam, Kwok Ho; Ji, Hong Fen; Zheng, Fan; Ren, Wei; Zhou, Qifa; Shung, K Kirk

    2013-07-01

    This paper presents the design, fabrication and characterization of single-element ultrahigh frequency (UHF) ultrasonic transducers in which the center frequency ranged from 170 to 320MHz. The center frequency of >300MHz is the highest value of lead-free ceramic ultrasonic transducers ever reported. With concern in the environmental pollution of lead-based materials, the transducer elements presented in this work were lead-free K0.5Na0.5NbO3/Bi0.5Na0.5TiO3 (KNN/BNT) composite thick films. All transducers were evaluated in a pulse-echo arrangement. The measured -6dB bandwidth of the transducers ranged from 35% to 64%. With the optimized piezoelectric properties of the composite film, the insertion loss of the UHF transducers was measured and determined to range from -50 to -60dB. In addition to the pulse-echo measurement, a 6μm tungsten wire phantom was also imaged with a 205MHz transducer to demonstrate the imaging capability. The measured -6dB axial and lateral resolutions were found to be 12μm and 50μm, respectively. The transducer performance presented in this work is shown to be better or comparable to previously reported results even though the frequency is much higher.

  4. Compatibility of Band 2 broadcast transmissions at frequencies below 105 MHz with private mobile radio in the band 105-108 MHz

    NASA Astrophysics Data System (ADS)

    Millard, G. H.; Thoday, R. D. C.

    1986-08-01

    Consideration is given to the problems that may arise with the operation of Private Mobile Radio (PMR) receiving base-stations using the frequency band 105 to 108 MHz in proximity to broadcast transmitters in Band 2. The existing criteria for the protection of the Broadcasting Service from land mobile and the protection of PMR from broadcast transmitters are given. Measurements made to assess the characteristics of both broadcast transmitters and PMR base-station receivers provide results for the levels of transmitter sideband noise and spurious emissions, and for the susceptibility of the base-station receivers to adjacent-channel interference. These show that the existing ITU sharing criteria for broadcast and mobile services in closely-spaced frequency bands are necessary but are insufficient to permit co-ordinate planning of these services on a non-interference bases. Results show the importance of taking these factors into account when planning these services.

  5. A COMBINED LOW-RADIO FREQUENCY/X-RAY STUDY OF GALAXY GROUPS. I. GIANT METREWAVE RADIO TELESCOPE OBSERVATIONS AT 235 MHz AND 610 MHz

    SciTech Connect

    Giacintucci, Simona; O'Sullivan, Ewan; Vrtilek, Jan; David, Laurence P.; Mazzotta, Pasquale; Gitti, Myriam; Jones, Christine; Forman, William R.; Raychaudhury, Somak; Ponman, Trevor; Venturi, Tiziana; Athreya, Ramana M.; Clarke, Tracy E.; Murgia, Matteo; Ishwara-Chandra, C. H.

    2011-05-10

    We present new Giant Metrewave Radio Telescope observations at 235 MHz and 610 MHz of 18 X-ray bright galaxy groups. These observations are part of an extended project, presented here and in future papers, which combines low-frequency radio and X-ray data to investigate the interaction between central active galactic nuclei (AGNs) and the intra-group medium (IGM). The radio images show a very diverse population of group-central radio sources, varying widely in size, power, morphology, and spectral index. Comparison of the radio images with Chandra and XMM-Newton X-ray images shows that groups with significant substructure in the X-ray band and marginal radio emission at {approx}>1 GHz host low-frequency radio structures that correlate with substructures in IGM. Radio-filled X-ray cavities, the most evident form of AGN/IGM interaction in our sample, are found in half of the systems and are typically associated with small, low-, or mid-power double radio sources. Two systems, NGC5044 and NGC4636, possess multiple cavities, which are isotropically distributed around the group center, possibly due to group weather. In other systems the radio/X-ray correlations are less evident. However, the AGN/IGM interaction can manifest itself through the effects of the high-pressure medium on the morphology, spectral properties, and evolution of the radio-emitting plasma. In particular, the IGM can confine fading radio lobes in old/dying radio galaxies and prevent them from dissipating quickly. Evidence for radio emission produced by former outbursts that co-exist with current activity is found in six groups of the sample.

  6. 47 CFR 27.1176 - Cost-sharing requirements for AWS in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... from this spectrum, including BRS incumbents occupying the 2150-2162 MHz band on a primary basis, must... § 27.1190. If an AWS licensee enters into a spectrum leasing arrangement and the spectrum...

  7. 47 CFR 27.1255 - Relocation Criteria for Broadband Radio Service Licensees in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... co-channel to the 2150-2160/62 MHz band, must relocate any incumbent BRS system that is within the... to Enable Multipoint Distribution Service and Instructional Television Fixed Service Licensees...

  8. 47 CFR 25.147 - Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.147 Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz. If an...

  9. 47 CFR 25.147 - Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.147 Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz. If an...

  10. 47 CFR 25.147 - Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.147 Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz. If an...

  11. 47 CFR 25.147 - Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.147 Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz. If an...

  12. Update on the CeC PoP 704 MHz 5-cell cavity cryomodule design and fabrication

    SciTech Connect

    Brutus, J. C.; Belomestnykh, S.; Ben-Zvi, I.; Grimm, T.; Huang, Y.; Jecks, R.; Kelly, M.; Litvinenko, V.; Pinayev, I.; Reid, T.; Skaritka, J.; Snydstrup, L.; Than, R.; Tuozzolo, J.; Xu, W.; Yancey, J.; Gerbick, S.

    2015-05-03

    A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the new technique of cooling proton and ion beams that may increase the beam luminosity in certain cases, by as much as tenfold. The 704 MHz cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up to 22MeV. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for CeC PoP experiment.

  13. 47 CFR 27.1255 - Relocation Criteria for Broadband Radio Service Licensees in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio... co-channel to the 2150-2160/62 MHz band, must relocate any incumbent BRS system that is within...

  14. Development of calibration techniques for ultrasonic hydrophone probes in the frequency range from 1 to 100 MHz

    NASA Astrophysics Data System (ADS)

    Umchid, Sumet

    The primary objective of this research was to develop and optimize the calibration techniques for ultrasonic hydrophone probes used in acoustic field measurements up to 100 MHz. A dependable, 100 MHz calibration method was necessary to examine the behavior of a sub-millimeter spatial resolution fiber optic (FO) sensor and assess the need for such a sensor as an alternative tool for high frequency characterization of ultrasound fields. Also, it was of interest to investigate the feasibility of using FO probes in high intensity fields such as those employed in HIFU (High Intensity Focused Ultrasound) applications. In addition to the development of a novel, 100 MHz calibration technique the innovative elements of this research include implementation of a prototype FO sensor with an active diameter of about 10 hum that exhibits uniform sensitivity over the considered frequency range and does not require any spatial averaging corrections up to about 75 MHz. The calibration technique provided the sensitivity of conventional, finite aperture piezoelectric hydrophone probes as a virtually continuous function of frequency and allowed the verification of the uniformity of the FO sensor frequency response. As anticipated, the overall uncertainty of the calibration was dependent on frequency and determined to be about +/-12% (+/-1 dB) up to 40 MHz, +/-20% (+/-1.5 dB) from 40 to 60 MHz and +/-25% (+/-2 dB) from 60 to 100 MHz. The outcome of this research indicates that once fully developed and calibrated, the combined acousto-optic system will constitute a universal reference tool in the wide, 100 MHz bandwidth.

  15. Evaluation of recurrent hyphema after trabeculectomy with ultrabiomicroscopy 50-80 MHz: a case report

    PubMed Central

    2012-01-01

    Background Hyphema is a complication that can occur after glaucoma filtering surgery. Biomicroscopic examination of the anterior segment is commonly used to diagnose it and gonioscopy may provide a useful support to find the source of the haemorrhage. Unfortunately, when the blood hides the structure of the anterior segment the gonioscopic examination fails. In this case we performed ultrabiomiscroscopy with 50–80 MHz probes to overcome the limits of gonioscopy. The use of this technique to study the anterior segment of the eye has previously been reported in literature, but we illustrates its importance for performing a correct diagnosis in a specific case of hyphema. Case presentation We report a case of a sixty-year-old caucasian male with recurrent hyphema in the left eye. The episodes of hyphema were four in two years and the patient came to the hospital for the first time in the last occasion. The past episodes were managed with topical corticosteroids and mydriatic drops. He referred surgical trabeculectomy in both eyes 5 years before the first symptoms and no specific eye trauma before the first episode. The examination of the anterior segment revealed a 2 mm hyphema in the left eye due to blood leakage through the superior iridectomy. Gonioscopy could not identify the source of the haemorrhage. B-scan ultrasound and ultrabiomiscroscopy, with 50–80 MHz probes, were performed. Ultrabiomiscroscopy, mainly with the probe of 80 MHz, provided images of high resolution of the structures of the anterior segment and it allowed the visualization of an abnormal vessel at the inner margin of the trabeculectomy opening, probably responsible of the recurrent hyphema. Conclusion Ultrabiomicroscopy proved to be a useful diagnostic technique for identifying the cause of the recurrent hyphema when other examination techniques are not applicable. PMID:23035908

  16. VizieR Online Data Catalog: NAIC 611 MHz Survey Source List (Durdin+ 1975)

    NASA Astrophysics Data System (ADS)

    Durdin, J. M.; Pleticha, D.; Condon, J. J.; Yerbury, M. J.; Jauncey, D. L.; Hazard, C.

    2000-01-01

    The 1000 foot Arecibo reflector was used with a multiple feed system to map the region 0h < RA < 12h, -2d < DEC < +18d at 611 MHz. The observations were made in meridian transit mode using an array of ten line feeds with the electric polarization vector in the east-west plane. The beam power pattern of each feed was approximately Gaussian and circulary symmetric with a half power beam width of about 12.6 arcmin. A source list was produced containing fluxes and positions of 3118 radio sources stronger than 0.35 Jy. The source list is complete for strong, unresolved sources. However it is not intended to be complete for objects highly resolved by the 12.6 arcmin beamsize. The list's lower limit of 0.35 Jy is about 5 times the average sky confusion. The survey was calibrated to the KPW (Kellermann, Pauliny-Toth, and Williams 1969ApJ...157....1K) flux scale. The secondary calibrators were ten sources measured at Arecibo at 606 MHz based on the KPW scale (Condon, Niell and Jauncey 1971). Marked by an asterisk in Table 2, these sources were too few to be used alone to calibrate all of the declination strips. Since a more complete list of good calibration sources did not exist at 611 MHz, the fluxes of 159 additional sources were independently measured accurate to about 7 percent at Arecibo in the Fall of 1973. Table 2 gives their assigned fluxes. These sources were tied to the KPW scale through the ten secondary calibrators. (2 data files).

  17. Phase-locked MHz pulse selector for x-ray sources.

    PubMed

    Förster, Daniel F; Lindenau, Bernd; Leyendecker, Marko; Janssen, Franz; Winkler, Carsten; Schumann, Frank O; Kirschner, Jürgen; Holldack, Karsten; Föhlisch, Alexander

    2015-05-15

    Picosecond x-ray pulses are extracted with a phase-locked x-ray pulse selector at 1.25 MHz repetition rate from the pulse trains of the accelerator-driven multiuser x-ray source BESSY II preserving the peak brilliance at high pulse purity. The system consists of a specially designed in-vacuum chopper wheel rotating with ≈1  kHz angular frequency. The wheel is driven in an ultrahigh vacuum and is levitated on magnetic bearings being capable of withstanding high centrifugal forces. Pulses are picked by 1252 high-precision slits of 70 μm width on the outer rim of the wheel corresponding to a temporal opening window of the chopper of 70 ns. We demonstrate how the electronic phase stabilization of ±2  ns together with an arrival time jitter of the individual slits of the same order of magnitude allows us to pick short single bunch x-ray pulses out of a 200 ns ion clearing gap in a multibunch pulse train as emitted from a synchrotron facility at 1.25 MHz repetition rate with a pulse purity below the shot noise detection limit. The approach is applicable to any high-repetition pulsed radiation source, in particular in the x-ray spectral range up to 10 keV. The opening window in a real x-ray beamline, its stability, as well as the limits of mechanical pulse picking techniques in the MHz range are discussed.

  18. The toxic effects of mobile phone radiofrequency (940 MHz) on the structure of calf thymus DNA.

    PubMed

    Hekmat, Azadeh; Saboury, Ali Akbar; Moosavi-Movahedi, Ali Akbar

    2013-02-01

    Currently, the biological effects of nonionizing electromagnetic fields (EMFs) including radiofrequency (RF) radiation have been the subject of numerous experimental and theoretical studies. The aim of this study is to evaluate the possible biological effects of mobile phone RF (940 MHz, 15 V/m and SAR=40 mW/kg) on the structure of calf thymus DNA (ct DNA) immediately after exposure and 2 h after 45 min exposure via diverse range of spectroscopic instruments. The UV-vis and circular dichroism (CD) experiments depict that mobile phone EMFs can remarkably cause disturbance on ct DNA structure. In addition, the DNA samples, immediately after exposure and 2 h after 45 min exposure, are relatively thermally unstable compared to the DNA solution, which was placed in a small shielded box (unexposed ct DNA). Furthermore, the exposed DNA samples (the DNA samples that were exposed to 940 MHz EMF) have more fluorescence emission when compared with the unexposed DNA, which may have occurred attributable to expansion of the exposed DNA structure. The results of dynamic light scattering (DLS) and zeta potential experiments demonstrate that RF-EMFs lead to increment in the surface charge and size of DNA. The structure of DNA immediately after exposure is not significantly different from the DNA sample 2 h after 45 min exposure. In other words, the EMF-induced conformational changes are irreversible. Collectively, our results reveal that 940 MHz can alter the structure of DNA. The displacement of electrons in DNA by EMFs may lead to conformational changes of DNA and DNA disaggregation. Results from this study could have an important implication on the health effects of RF-EMFs exposure. In addition, this finding could proffer a novel strategy for the development of next generation of mobile phone.

  19. Proliferation and cytogenetic studies in human blood lymphocytes exposed in vitro to 2450 MHz radiofrequency radiation.

    PubMed

    Vijayalaxmi; Mohan, N; Meltz, M L; Wittler, M A

    1997-12-01

    Aliquots of human peripheral blood collected from two healthy human volunteers were exposed in vitro to continuous wave 2450 MHz radiofrequency radiation (RFR), either continuously for a period of 90 min or intermittently for a total exposure period of 90 min (30 min on and 30 min off, repeated three times). Blood aliquots which were sham-exposed or exposed in vitro to 150 cGy gamma radiation served as controls. The continuous wave 2450 MHz RFR was generated with a net forward power of 34.5 W and transmitted from a standard gain rectangular antenna horn in a vertically downward direction. The mean power density at the position of the cells was 5.0 mW/cm2. The mean specific absorption rate calculated by Finite Difference Time Domain analysis was 12.46 W/kg. Immediately after exposure, lymphocytes were cultured for 48 and 72 h to determine the incidence of chromosomal aberrations and micronuclei, respectively. Proliferation indices were also recorded. There were no significant differences between RFR-exposed and sham-exposed lymphocytes with respect to; (a) mitotic indices; (b) incidence of cells showing chromosome damage; (c) exchange aberrations; (d) acentric fragments; (e) binucleate lymphocytes, and (f) micronuclei, for either the continuous or intermittent RFR exposures. In contrast, the response of positive control cells exposed to 150 cGy gamma radiation was significantly different from RFR-exposed and sham-exposed lymphocytes. Thus, there is no evidence for an effect on mitogen-stimulated proliferation kinetics or for excess genotoxicity within 72 h in human blood lymphocytes exposed in vitro to 2450 MHz RFR.

  20. Central FPGA-based destination and load control in the LHCb MHz event readout

    NASA Astrophysics Data System (ADS)

    Jacobsson, R.

    2012-10-01

    The readout strategy of the LHCb experiment is based on complete event readout at 1 MHz. A set of 320 sub-detector readout boards transmit event fragments at total rate of 24.6 MHz at a bandwidth usage of up to 70 GB/s over a commercial switching network based on Gigabit Ethernet to a distributed event building and high-level trigger processing farm with 1470 individual multi-core computer nodes. In the original specifications, the readout was based on a pure push protocol. This paper describes the proposal, implementation, and experience of a non-conventional mixture of a push and a pull protocol, akin to credit-based flow control. An FPGA-based central master module, partly operating at the LHC bunch clock frequency of 40.08 MHz and partly at a double clock speed, is in charge of the entire trigger and readout control from the front-end electronics up to the high-level trigger farm. One FPGA is dedicated to controlling the event fragment packing in the readout boards, the assignment of the farm node destination for each event, and controls the farm load based on an asynchronous pull mechanism from each farm node. This dynamic readout scheme relies on generic event requests and the concept of node credit allowing load control and trigger rate regulation as a function of the global farm load. It also allows the vital task of fast central monitoring and automatic recovery in-flight of failing nodes while maintaining dead-time and event loss at a minimum. This paper demonstrates the strength and suitability of implementing this real-time task for a very large distributed system in an FPGA where no random delays are introduced, and where extreme reliability and accurate event accounting are fundamental requirements. It was in use during the entire commissioning phase of LHCb and has been in faultless operation during the first two years of physics luminosity data taking.

  1. A 14-bit 40-MHz analog front end for CCD application

    NASA Astrophysics Data System (ADS)

    Jingyu, Wang; Zhangming, Zhu; Shubin, Liu

    2016-06-01

    A 14-bit, 40-MHz analog front end (AFE) for CCD scanners is analyzed and designed. The proposed system incorporates a digitally controlled wideband variable gain amplifier (VGA) with nearly 42 dB gain range, a correlated double sampler (CDS) with programmable gain functionality, a 14-bit analog-to-digital converter and a programmable timing core. To achieve the maximum dynamic range, the VGA proposed here can linearly amplify the input signal in a gain range from -1.08 to 41.06 dB in 6.02 dB step with a constant bandwidth. A novel CDS takes image information out of noise, and further amplifies the signal accurately in a gain range from 0 to 18 dB in 0.035 dB step. A 14-bit ADC is adopted to quantify the analog signal with optimization in power and linearity. An internal timing core can provide flexible timing for CCD arrays, CDS and ADC. The proposed AFE was fabricated in SMIC 0.18 μm CMOS process. The whole circuit occupied an active area of 2.8 × 4.8 mm2 and consumed 360 mW. When the frequency of input signal is 6.069 MHz, and the sampling frequency is 40 MHz, the signal to noise and distortion (SNDR) is 70.3 dB, the effective number of bits is 11.39 bit. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033), the National High-Tech Program of China (No. 2013AA014103), and the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory (No. ZHD201302).

  2. Fabrication of the prototype 201.25 mhz cavity for a muon ionization cooling experiment

    SciTech Connect

    Rimmer, R.A.; Manning, S.; Manus, R.; Phillips, L.; Stirbet, M.; Worland, K.; Wu, G.; Li, D.; MacGill, R.; Staples, J.; Virostek, S.; Zisman, M.S.; Taminger, K.; Hafley, R.; Martin, R.; Summers, D.; Reep, M.

    2005-05-20

    We describe the fabrication and assembly of the first prototype 201. 25 MHz copper cavity for the muon ionization cooling experiment (MICE). This cavity was developed by the US MUCOOL collaboration and will be tested in the new MUCOOL Test Area at Fermilab. We outline the component and subassembly fabrication steps and the various metal forming and joining methods used to produce the final cavity shape. These include spinning, brazing, TIG welding, electron beam welding, electron beam annealing and deep drawing. Some of the methods developed for this cavity are novel and offer significant cost savings over conventional methods.

  3. Fabrication of the Prototype 201.25 MHz Cavity for a Muon Ionization Cooling Experiment

    SciTech Connect

    R.A. Rimmer; S. Manning; R. Manus; L. Phillips; M. Stirbet; K. Worland; G. Wu; D. Li; R. MacGill; J. Staples; S. Virostek; M. Zisman; K. Taminger; R. Hafley; R. Martin; D. Summers; M. Reep

    2005-05-01

    We describe the fabrication and assembly of the first prototype 201.25 MHz copper cavity for the muon ionization cooling experiment (MICE). This cavity was developed by the US MUCOOL collaboration and will be tested in the new MUCOOL Test Area at Fermilab. We outline the component and subassembly fabrication steps and the various metal forming and joining methods used to produce the final cavity shape. These include spinning, brazing, TIG welding, electron beam welding, electron beam annealing and deep drawing. Some of the methods developed for this cavity are novel and offer significant cost savings over conventional construction methods.

  4. Mapping the radio sky from 0.1 to 100 MHz with NOIRE

    NASA Astrophysics Data System (ADS)

    Cecconi, B.; Laurens, A.; Briand, C.; Girard, J.; Bucher, M.; Puy, D.; Segret, B.; Bentum, M.

    2016-12-01

    The goal of the NOIRE study (Nanosats pour un Observatoire Interférométrique Radio dans l'Espace) is to assess the scientific interest and technical feasibility of a space borne radio interferometer operating from a few kHz to a few 10 MHz. Such observatory would be able to build a global sky map with an unprecedented spatial resolution depending on the selected technical implementation. We present a review of our understanding of the Galactic mapping, assessing the instrument requirement for such observations.

  5. Bulk Current Injection Testing of Cable Noise Reduction Techniques, 50 kHz to 400 MHz

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur T.; Hare, Richard J.; Singh, Manisha

    2009-01-01

    This paper presents empirical results of cable noise reduction techniques as demonstrated using bulk current injection (BCI) techniques with radiated fields from 50 kHz - 400 MHz. It is a follow up to the two-part paper series presented at the Asia Pacific EMC Conference that focused on TEM cell signal injection. This paper discusses the effects of cable types, shield connections, and chassis connections on cable noise. For each topic, well established theories are compared with data from a real-world physical system.

  6. VLA observations of the supernova remnant Puppus A at 327 and 1515 MHz

    NASA Technical Reports Server (NTRS)

    Dubner, G. M.; Braun, R.; Winkler, P. F.; Goss, W. M.

    1991-01-01

    Very Large Array radio images of Puppis A at 327 and 1515 MHz are presented. The observations were performed with the VLA in the C/D and B/C configurations, respectively. The angular resolution is about 77 arcsec x 43 arcsec. The observed radio shell shows signs of interaction between the expanding shock front and the inhomogeneous surrounding medium. An excellent correlation is found between radio and X-ray emission, mainly toward the NE border of the remnant. There is little correspondence between the optical and radio images, suggesting a different origin for the emission. A region of steeper radio spectral index is associated with the highly decelerated eastern periphery.

  7. Sonoluminescence and sonochemiluminescence study of cavitation field in a 1.2MHz focused ultrasound

    NASA Astrophysics Data System (ADS)

    Yin, Hui; Qiao, Yangzi; Cao, Hua; Wan, Mingxi

    2017-03-01

    An intensified CCD (ICCD) and an electron-multiplying CCD (EMCCD) were employed to observe the spatial distribution of sonoluminescence (SL) and sonochemiluminescence (SCL) generated by cavitation bubbles in a 1.2MHz HIFU field. Various sonication conditions, which are free field and focal region near a water-parenchyma interface, were studied. In addition, the differences of two shells coated UCAs were also investigated. In this study, an acoustic radiation force (ARF) counterbalance appliance was added to reduce bubble displacement. Cavitation mapping in this situation was also operated through SCL recording. SCL was also employed to measure cavitation does and map the spatial distribution of cavitation near a boundary of parenchyma.

  8. Acoustic emissions during 3.1 MHz ultrasound bulk ablation in vitro.

    PubMed

    Mast, T Douglas; Salgaonkar, Vasant A; Karunakaran, Chandrapriya; Besse, John A; Datta, Saurabh; Holland, Christy K

    2008-09-01

    Acoustic emissions associated with cavitation and other bubble activity have previously been observed during ultrasound (US) ablation experiments. Because detectable bubble activity may be related to temperature, tissue state and sonication characteristics, these acoustic emissions are potentially useful for monitoring and control of US ablation. To investigate these relationships, US ablation experiments were performed with simultaneous measurements of acoustic emissions, tissue echogenicity and tissue temperature on fresh bovine liver. Ex vivo tissue was exposed to 0.9-3.3-s bursts of unfocused, continuous-wave, 3.10-MHz US from a miniaturized 32-element array, which performed B-scan imaging with the same piezoelectric elements during brief quiescent periods. Exposures used pressure amplitudes of 0.8-1.4 MPa for exposure times of 6-20 min, sufficient to achieve significant thermal coagulation in all cases. Acoustic emissions received by a 1-MHz, unfocused passive cavitation detector, beamformed A-line signals acquired by the array, and tissue temperature detected by a needle thermocouple were sampled 0.3-1.1 times per second. Tissue echogenicity was quantified by the backscattered echo energy from a fixed region-of-interest within the treated zone. Acoustic emission levels were quantified from the spectra of signals measured by the passive cavitation detector, including subharmonic signal components at 1.55 MHz, broadband signal components within the band 0.3-1.1 MHz and low-frequency components within the band 10-30 kHz. Tissue ablation rates, defined as the thermally ablated volumes per unit time, were assessed by quantitative analysis of digitally imaged, macroscopic tissue sections. Correlation analysis was performed among the averaged and time-dependent acoustic emissions in each band considered, B-mode tissue echogenicity, tissue temperature and ablation rate. Ablation rate correlated significantly with broadband and low-frequency emissions, but was

  9. Effects of microwaves (900 MHz) on the cochlear receptor: exposure systems and preliminary results.

    PubMed

    Marino, C; Cristalli, G; Galloni, P; Pasqualetti, P; Piscitelli, M; Lovisolo, G A

    2000-06-01

    The purpose of this paper is to present the experimental device and the work in progress performed in search for objective organic correlation of damage to hearing, examining possible acoustic otofunctional effects on the cochlear epithelium of the rat due to exposure to microwaves (900 MHz). Two experiments using male Sprague-Dawley rats were carried out with a far-field exposure in a cubic chamber. No statistically significant evidence was obtained at both specific absorption rate (SAR) values. The exposure system and the diagnostic apparatus are extremely useful to investigate a potential effect on the auditory system: however, with the parameters applied in these experiments, no evidence was observed.

  10. Design and Construction of a New 1420 MHz Receiver System for a 12-meter Radio Telescope

    NASA Astrophysics Data System (ADS)

    Lemley, Cameron; Castelaz, M. W.

    2014-01-01

    During the summer of 2013, a new 1420 MHz receiver system was designed and constructed for the 12-meter radio telescope at the Pisgah Astronomical Research Institute (PARI). The new radio receiver system consists of a feedhorn (which is a duplicate of the feedhorn that is currently installed on PARI’s 4.6-meter radio telescope), a low-noise amplifier, a bandpass filter, a downconverter, a SpectraCyber 1420 MHz Hydrogen Line Spectrometer, CommScope CNT-600 braided coaxial cable, and a power supply. Each component was individually tested on the preexisting 4.6-meter radio telescope receiver system before being installed on the 12-meter telescope. This testing process revealed that the spectrometer that was intended for use in the new 12-meter receiver system would require 12-bit software, which was acquired soon thereafter. The new receiver system was then assembled on a rolling cart for further testing. After the 1420 MHz receiver system was moved outside, it successfully detected its first extraterrestrial radio signal. The next step of this project was the installation of the feedhorn at the focus of the 12-meter parabolic reflector and the mounting of the additional receiver system components inside the radio frequency (RF) room of the 12-meter telescope. Following its installation on the 12-meter telescope, the new receiver system was connected to the PARI network via ethernet using a device called a SitePlayer Telnet. The 12-meter telescope was focused by taking continuum scans of Virgo A during its meridian crossing. The positioning of the feedhorn had to be adjusted several times before the new radio receiver system was precisely focused. After focusing the 12-meter telescope, spectra were taken of both the Orion Nebula and the Crab Nebula to test the abilities of the new 1420 MHz receiver system. As a final test of both the angular resolution and time resolution of the new radio receiver system, the 12-meter telescope was used to observe the pulsar PSR J

  11. Development and Production of a 201 MHz, 5.0 MW Peak Power Klystron

    SciTech Connect

    Aymar, Galen; Eisen, Edward; Stockwell, Brad; Begum, rasheda; Lenci, Steve; Eisner, Rick; Cesca, Eugene

    2016-01-01

    Communications & Power Industries LLC has designed and manufactured the VKP-8201A, a high peak power, high gain, VHF band klystron. The klystron operates at 201.25 MHz, with 5.0 MW peak output power, 34 kW average output power, and a gain of 36 dB. The klystron is designed to operate between 1.0 MW and 4.5 MW in the linear range of the transfer curve. The klystron utilizes a unique magnetic field which enables the use of a proven electron gun design with a larger electron beam requirement. Experimental and predicted performance data are compared.

  12. Picosecond supercontinuum laser with consistent emission parameters over variable repetition rates from 1 to 40 MHz

    NASA Astrophysics Data System (ADS)

    Schönau, Thomas; Siebert, Torsten; Härtel, Romano; Klemme, Dietmar; Lauritsen, Kristian; Erdmann, Rainer

    2013-02-01

    An freely triggerable picosecond visible supercontinuum laser source is presented that allows for a uniform spectral profile and equivalent pulse characteristics over variable repetition rates from 1 to 40MHz. The system features PM Yb3+-doped fiber amplification of a picosecond gain-switched seed diode at 1062 nm. The pump power in the multi-stage amplifier is actively adjusted by a microcontroller for a consistent peak power of the amplified signal in the full range of repetition rates. The length of the PCF is scaled to deliver a homogeneous spectrum and minimized distortion of the temporal pulse shape.

  13. Ultrasonic Scattering Measurements of a Live Single Cell at 86 MHz

    PubMed Central

    Lee, Changyang; Jung, Hayong; Lam, Kwok Ho; Yoon, Changhan; Shung, K. Kirk

    2016-01-01

    Cell separation and sorting techniques have been employed biomedical applications such as cancer diagnosis and cell gene expression analysis. The capability to accurately measure ultrasonic scattering properties from cells is crucial in making an ultrasonic cell sorter a reality if ultrasound scattering is to be used as the sensing mechanism as well. To assess the performance of sensing and identifying live single cells with high-frequency ultrasound, an 86-MHz lithium niobate press-focused single-element acoustic transducer was used in a high-frequency ultrasound scattering measurement system that was custom designed and developed for minimizing noise and allowing better mobility. Peak-to-peak echo amplitude, integrated backscatter (IB) coefficient, spectral parameters including spectral slope and intercept, and midband fit from spectral analysis of the backscattered echoes were measured and calculated from a live single cell of two different types on an agar surface: leukemia cells (K562 cells) and red blood cells (RBCs). The amplitudes of echo signals from K562 cells and RBCs were 48.25 ± 11.98 mVpp and 56.97 ± 7.53 mVpp, respectively. The IB coefficient was −89.39 ± 2.44 dB for K562 cells and −89.00 ± 1.19 dB for RBCs. The spectral slope and intercept were 0.30 ± 0.19 dB/MHz and −56.07 ± 17.17 dB, respectively, for K562 cells and 0.78 ± 0.092 dB/MHz and −98.18 ± 8.80 dB, respectively, for RBCs. Midband fits of K562 cells and RBCs were −31.02 ± 3.04 dB and −33.51 ± 1.55 dB, respectively. Acoustic cellular discrimination via these parameters was tested by Student’s t-test. Their values, except for the IB value, showed statistically significant difference (p < 0.001). This paper reports for the first time that ultrasonic scattering measurements can be made on a live single cell with a highly focused high-frequency ultrasound microbeam at 86 MHz. These results also suggest the feasibility of ultrasonic scattering as a sensing mechanism in

  14. Front end processing for a 100 MHZ Flash-ADC-System

    SciTech Connect

    Eckerlin, G.; Elsen, E.; Schmitt, H.V.D.; Wagner, A.; Walter, P.V.

    1986-06-01

    An intelligent interface for readout of a high speed (100 MHz), multichannel Flash-ADC System is described. 3072 FADC channels are controlled and read by a system of 34 microprocessors M68000 placed at two different hierarchical levels. In addition to the readout itself, the processors perform a detailed pulse shape analysis necessary for a compact and manageable data format. The purpose of the system is to exploit the good double tract separation and time resolution provided by Flash-ADCs in conjunction with large drift chamber detectors such as JADE at PETRA and OPAL at LEP. Details of the system presently being installed at JADE are reviewed.

  15. Status of the mechanical design of the 650 MHz cavities for Project X

    SciTech Connect

    Barbanotti, S.; Grimm, C.; Champion, M.; Foley, M.; Ginsburg, C.M.; Gonin, I.; Peterson, T.; Ristori, L.; Yakovlev, V.; /Fermilab

    2011-03-01

    In the high-energy section of the Project X Linac, acceleration of H{sup -} ions takes place in superconducting cavities operating at 650 MHz. Two families of five-cell elliptical cavities are planned: beta = 0.61 and beta = 0.9. A specific feature of the Project X Linac is low beam loading, and thus, low bandwidth and higher sensitivity to microphonics. Efforts to optimize the mechanical design of the cavities to improve their mechanical stability in response to the helium bath pressure fluctuations will be presented. These efforts take into account constraints such as cost and ease of fabrication. Also discussed will be the overall design status of the cavities and their helium jackets. The proposed design of the 3 GeV Project X superconducting (SC) Linac employs 650 MHz five-cell elliptical cavities to accelerate 1.0 mA of average H-beam current in the 160-3000 MeV energy range. The 650 MHz region of the Linac is divided into two sections with two different geometric phase velocity factors: beta = 0.61 to cover the 160-520 MeV range and beta = 0.9 to cover the 520-3000 MeV range. Approximately 40 beta = 0.61 and 150 beta = 0.9 cavities are currently planned for the project. An R&D program is in progress at FNAL, in collaboration with TJNAF and India, to develop the 650 MHz cavities for the proposed Linac design. This R&D program includes the design and fabrication of several beta = 0.61 and beta = 0.9 single-cell prototypes for evaluation prior to production of the five-cell cavities. FNAL has contracted AES to fabricate the beta = 0.9 prototypes, while TJNAF is building beta = 0.61 prototypes of their own design. In the remainder of this paper we will restrict our discussion to the five-cell beta = 0.9 cavities.

  16. First high gradient test results of a dressed 325 MHz superconducting single spoke resonator at Fermilab

    SciTech Connect

    Webber, R.C.; Khabiboulline, T.; Madrak, R.; Nicol, T.; Ristori, L.; Soyars, W.; Wagner, R.; /Fermilab

    2010-09-01

    A new superconducting RF cavity test facility has been commissioned at Fermilab in conjunction with first tests of a 325 MHz, {beta} = 0.22 superconducting single-spoke cavity dressed with a helium jacket and prototype tuner. The facility is described and results of full gradient, CW cavity tests with a high Q{sub ext} drive coupler are reported. Sensitivities to Q disease and externally applied magnetic fields were investigated. Results are compared to bare cavity results obtained prior to hydrogen degassing and welding into the helium jacket.

  17. Simulations of multipacting in the cathode stalk and FPC of 112 MHz superconducting electron gun

    SciTech Connect

    Xin T.; Ben-Zvi, I.; Belomestnykh, S.; Chang, X.; Rao, T.; Skaritka, J.; Wu, Q.; Wang, E.; Liang, X.

    2012-05-20

    A 112 MHz superconducting quarter-wave resonator electron gun will be used as the injector of the Coherent Electron Cooling (CEC) proof-of-principle experiment at BNL. Furthermore, this electron gun can be used for testing of the performance of various high quantum efficiency photocathodes. In a previous paper, we presented the design of the cathode stalks and a Fundamental Power Coupler (FPC). In this paper we present updated designs of the cathode stalk and FPC. Multipacting in the cathode stalk and FPC was simulated using three different codes. All simulation results show no serious multipacting in the cathode stalk and FPC.

  18. 3D simulations of multipacting in the 56 MHz SRF cavity

    SciTech Connect

    Wu Q.; Belomestnykh, S.; Ge, L.; Ko, K.; Li, Z.; Ng, C.; Xiao, L.

    2012-05-20

    The 56 MHz SRF Quarter-Wave Resonator (QWR) is designed for RHIC as a storage cavity to improve the collider performance. 2D multipacting simulation has been done for the cavity alone. Ripples were added to the outer body of the cavity for multipacting suppression based on the simulation findings. During operation, there will be four higher order mode (HOM) couplers. All of these components will be exposed to high RF fields. In this paper we compare 2D and 3D codes simulation results for multipacting in the cavity. We also report 3D simulation results for multipacting simulation at the couplers.

  19. Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity

    SciTech Connect

    Burrill,A.

    2009-01-01

    The 56 MHz cavity presents a unique challenge in preparing it for RF testing prior to construction of the cryomodule. This challenge arises due to the physical dimensions and subsequent weight of the cavity, and is further complicated by the coaxial geometry, and the need to properly chemically etch and high pressure rinse the entire inner surface prior to RF testing. To the best of my knowledge, this is the largest all niobium SRF cavity to be chemically etched and subsequently tested in a vertical dewar at 4K, and these processes will be the topic of this technical note.

  20. Frequency-domain multiplex with eight-input SQUID and readout electronics over 1 MHz

    NASA Astrophysics Data System (ADS)

    Masui, K.; Takei, Y.; Ikeda, H.; Kimura, S.; Mitsuda, K.; Yamasaki, N. Y.

    2006-04-01

    In a magnetic summation method, TES and SQUID driving circuits are isolated and thus small crosstalk and stray impedance are expected. Since a FLL circuit with a large bandwidth and a small noise level is required for a SQUID, we designed and produced an electronics to meet our design of multiplexing with an 8-input SQUID. The FLL circuit achieved an open loop-gain bandwidth product of 8 MHz with 1 m wire length, which is enough for a TES to be operated with a bias current of 70 μA, and a noise level of 30 pA/√{Hz}.

  1. A model of diffuse Galactic radio emission from 10 MHz to 100 GHz

    NASA Astrophysics Data System (ADS)

    de Oliveira-Costa, Angélica; Tegmark, Max; Gaensler, B. M.; Jonas, Justin; Landecker, T. L.; Reich, Patricia

    2008-07-01

    Understanding diffuse Galactic radio emission is interesting both in its own right and for minimizing foreground contamination of cosmological measurements. cosmic microwave background experiments have focused on frequencies >~10GHz, whereas 21-cm tomography of the high-redshift universe will mainly focus on <~0.2GHz, for which less is currently known about Galactic emission. Motivated by this, we present a global sky model derived from all publicly available total power large-area radio surveys, digitized with optical character recognition when necessary and compiled into a uniform format, as well as the new Villa Elisa data extending the 1.42-GHz map to the entire sky. We quantify statistical and systematic uncertainties in these surveys by comparing them with various global multifrequency model fits. We find that a principal component based model with only three components can fit the 11 most accurate data sets (at 10, 22, 45 and 408 MHz and 1.42, 2.326, 23, 33, 41, 61, 94 GHz) to an accuracy around 1-10 per cent depending on frequency and sky region. Both our data compilation and our software returning a predicted all-sky map at any frequency from 10 MHz to 100 GHz are publicly available at http://space.mit.edu/home/angelica/gsm.

  2. Design and first cold test of BNL superconducting 112 MHz QWR for electron gun applications

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Boulware, C.H.; Chang, X.; Grimm, T.L.; Siegel, B.; Than, R.; Winowski, M.

    2011-03-28

    Brookhaven National Laboratory and Niowave, Inc. have designed, fabricated, and performed the first cold test of a superconducting 112 MHz quarter-wave resonator (QWR) for electron gun experiments. The first cold test of the QWR cryomodule has been completed at Niowave. The paper discusses the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule for future experiments. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electron cooling ion/proton beams at RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline plans for the cryomodule upgrade for future experiments.

  3. Radial Modulation Contrast Imaging Using a 20-MHz Single-Element Intravascular Ultrasound Catheter

    PubMed Central

    Yu, Francois T. H.; Villanueva, Flordeliza S.; Chen, Xucai

    2014-01-01

    Contrast-enhanced intravascular ultrasound imaging is a promising tool for the characterization of coronary vasa vasorum proliferation, which has been identified as a marker of, and possible etiologic factor in, the development of high-risk atherosclerotic plaques. Resonance-based nonlinear detection methods have required the development of prototype catheters which are not commercially available, thus limiting clinical translation. In this study, we investigated the performances of a radial modulation imaging approach (25/3 MHz combination) using simulations, implemented it on a clinical 20-MHz rotating catheter, and tested it in a wall-less tissue-mimicking flow phantom perfused with lipid-encapsulated microbubbles (MBs). The effects of the phase lag, low-frequency pressure, and MB concentration on the envelope subtracted radial modulation signals were investigated as a function of depth. Our dual-pulse dual-frequency approach produced contrast-specific images with contrast-to-tissue improvements over B-mode of 15.1 ± 2.1 dB at 2 mm and 6.8 ± 0.1 dB at 4 mm depths. Using this imaging strategy, 200-μm-diameter cellulose tubing perfused with MBs could be resolved while surrounding tissue scattering was suppressed. These results raise promise for the detection of coronary vasa vasorum and may ultimately facilitate the detection of plaque at risk for rupture. PMID:24803134

  4. MHz rate and efficient synchronous heralding of single photons at telecom wavelengths.

    PubMed

    Pomarico, Enrico; Sanguinetti, Bruno; Guerreiro, Thiago; Thew, Rob; Zbinden, Hugo

    2012-10-08

    We report on the realization of a synchronous source of heralded single photons at telecom wavelengths with MHz heralding rates and high heralding efficiency. This source is based on the generation of photon pairs at 810 and 1550 nm via Spontaneous Parametric Down Conversion (SPDC) in a 1 cm periodically poled lithium niobate (PPLN) crystal pumped by a 532 nm pulsed laser. As high rates are fundamental for multi-photon experiments, we show that single telecom photons can be announced at 4.4 MHz rate with 45% heralding efficiency. When we focus only on the optimization of the coupling of the heralded photon, the heralding efficiency can be increased up to 80%. Furthermore, we experimentally observe that group velocity mismatch inside long crystals pumped in a pulsed mode affects the spectrum of the emitted photons and their fibre coupling efficiency. The length of the crystal in this source has been chosen as a trade off between high brightness and high coupling efficiency.

  5. 28 MHz swept source at 1.0 μm for ultrafast quantitative phase imaging

    PubMed Central

    Wei, Xiaoming; Lau, Andy K. S.; Xu, Yiqing; Tsia, Kevin K.; Wong, Kenneth K. Y.

    2015-01-01

    Emerging high-throughput optical imaging modalities, in particular those providing phase information, necessitate a demanding speed regime (e.g. megahertz sweep rate) for those conventional swept sources; while an effective solution is yet to be demonstrated. We demonstrate a stable breathing laser as inertia-free swept source (BLISS) operating at a wavelength sweep rate of 28 MHz, particularly for the ultrafast interferometric imaging modality at 1.0 μm. Leveraging a tunable dispersion compensation element inside the laser cavity, the wavelength sweep range of BLISS can be tuned from ~10 nm to ~63 nm. It exhibits a good intensity stability, which is quantified by the ratio of standard deviation to the mean of the pulse intensity, i.e. 1.6%. Its excellent wavelength repeatability, <0.05% per sweep, enables the single-shot imaging at an ultrafast line-scan rate without averaging. To showcase its potential applications, it is applied to the ultrafast (28-MHz line-scan rate) interferometric time-stretch (iTS) microscope to provide quantitative morphological information on a biological specimen at a lateral resolution of 1.2 μm. This fiber-based inertia-free swept source is demonstrated to be robust and broadband, and can be applied to other established imaging modalities, such as optical coherence tomography (OCT), of which an axial resolution better than 12 μm can be achieved. PMID:26504636

  6. A LOFAR Detection of the Low-mass Young Star T Tau at 149 MHz

    NASA Astrophysics Data System (ADS)

    Coughlan, Colm P.; Ainsworth, Rachael E.; Eislöffel, Jochen; Hoeft, Matthias; Drabent, Alexander; Scaife, Anna M. M.; Ray, Tom P.; Bell, Martin E.; Broderick, Jess W.; Corbel, Stéphane; Grießmeier, Jean-Mathias; van der Horst, Alexander J.; van Leeuwen, Joeri; Markoff, Sera; Pietka, Malgorzata; Stewart, Adam J.; Wijers, Ralph A. M. J.; Zarka, Philippe

    2017-01-01

    Radio observations of young stellar objects (YSOs) enable the study of ionized plasma outflows from young protostars via their free–free radiation. Previous studies of the low-mass young system T Tau have used radio observations to model the spectrum and estimate important physical properties of the associated ionized plasma (local electron density, ionized gas content, and emission measure). However, without an indication of the low-frequency turnover in the free–free spectrum, these properties remain difficult to constrain. This paper presents the detection of T Tau at 149 MHz with the Low Frequency Array (LOFAR)—the first time a YSO has been observed at such low frequencies. The recovered total flux indicates that the free–free spectrum may be turning over near 149 MHz. The spectral energy distribution is fitted and yields improved constraints on local electron density ((7.2+/- 2.1)× {10}3 cm‑3), ionized gas mass ((1.0+/- 1.8)× {10}-6 {M}ȯ ), and emission measure ((1.67+/- 0.14)× {10}5 pc cm‑6).

  7. A 250 MHz Level 1 Trigger and Distribution System for the GlueX experiment

    SciTech Connect

    Abbott, David J.; Cuevas, R. Christopher; Doughty, David Charles; Jastrzembski, Edward A.; Barbosa, Fernando J.; Raydo, Benjamin J.; Dong, Hai T.; Wilson, Jeffrey S.; Gupta, Abishek; Taylor, Mark; Somov, S.

    2009-11-01

    The GlueX detector now under construction at Jefferson Lab will search for exotic mesons though photoproduction (10^8 tagged photons per second) on a liquid hydrogen target. A Level 1 hardware trigger design is being developed to reduce total electromagnetic (>200 MHz) and hadronic (>350 kHz) rates to less than 200 kHz. This trigger is dead timeless and operates on a global synchronized 250 MHz clock. The core of the trigger design is based on a custom pipelined flash ADC board that uses a VXS backplane to collect samples from all ADCs in a VME crate. A custom switch-slot board called a Crate Trigger Processor (CTP) processes this data and passes the crate level data via a multi-lane fiber optic link to the Global Trigger Processing Crate (also VXS). Within this crate detector sub-system processor (SSP) boards can accept all individual crate links. The subsystem data are processed and finally passed to global trigger boards (GTP) where the final L1 decision is made. We present details of the trigger design and report some performance results on current prototype systems.

  8. Evaluation of a 433 MHz Band Body Sensor Network for Biomedical Applications

    PubMed Central

    Kim, Saim; Brendle, Christian; Lee, Hyun-Young; Walter, Marian; Gloeggler, Sigrid; Krueger, Stefan; Leonhardt, Steffen

    2013-01-01

    Body sensor networks (BSN) are an important research topic due to various advantages over conventional measurement equipment. One main advantage is the feasibility to deploy a BSN system for 24/7 health monitoring applications. The requirements for such an application are miniaturization of the network nodes and the use of wireless data transmission technologies to ensure wearability and ease of use. Therefore, the reliability of such a system depends on the quality of the wireless data transmission. At present, most BSNs use ZigBee or other IEEE 802.15.4 based transmission technologies. Here, we evaluated the performance of a wireless transmission system of a novel BSN for biomedical applications in the 433 MHz ISM band, called Integrated Posture and Activity NEtwork by Medit Aachen (IPANEMA) BSN. The 433 MHz ISM band is used mostly by implanted sensors and thus allows easy integration of such into the BSN. Multiple measurement scenarios have been assessed, including varying antenna orientations, transmission distances and the number of network participants. The mean packet loss rate (PLR) was 0.63% for a single slave, which is comparable to IEEE 802.15.4 BSNs in the proximity of Bluetooth or WiFi networks. Secondly, an enhanced version is evaluated during on-body measurements with five slaves. The mean PLR results show a comparable good performance for measurements on a treadmill (2.5%), an outdoor track (3.4%) and in a climate chamber (1.5%). PMID:23344383

  9. Induction of Autophagy in the Striatum and Hypothalamus of Mice after 835 MHz Radiofrequency Exposure

    PubMed Central

    Kim, Hak Rim

    2016-01-01

    The extensive use of wireless mobile phones and associated communication devices has led to increasing public concern about potential biological health-related effects of the exposure to electromagnetic fields (EMFs). EMFs emitted by a mobile phone have been suggested to influence neuronal functions in the brain and affect behavior. However, the affects and phenotype of EMFs exposure are unclear. We applied radiofrequency (RF) of 835 MHz at a specific absorption rate (SAR) of 4.0 W/kg for 5 hours/day for 4 and 12 weeks to clarify the biological effects on mouse brain. Interestingly, microarray data indicated that a variety of autophagic related genes showed fold-change within small range after 835 MHz RF exposure. qRT-PCR revealed significant up-regulation of the autophagic genes Atg5, LC3A and LC3B in the striatum and hypothalamus after a 12-week RF. In parallel, protein expression of LC3B-II was also increased in both brain regions. Autophagosomes were observed in the striatum and hypothalamus of RF-exposed mice, based on neuronal transmission electron microscopy. Taken together, the results indicate that RF exposure of the brain can induce autophagy in neuronal tissues, providing insight into the protective mechanism or adaptation to RF stress. PMID:27073885

  10. NRAO 43-m telescope operation at 170-1700 MHz: a Bi-Static Radar Collaboration

    NASA Astrophysics Data System (ADS)

    Langston, Glen

    2007-08-01

    The NRAO 43m telescope has been refurbished and begun regular observations in the frequency range 170 - 1700 MHz. The 43 m operations support a Bi-Static Radar Collaboration to measure the Earth's ionospheric turbulence. Researchers from Chalmers University of Technology in Sweden have designed and built a unique design wide-band feed, 150 - 1700 MHz. Lincoln Laboratories/MIT has packaged the feed with room temperature low noise amplifiers. Lincoln Laboratories has installed a high-dynamic range RF system together with a wide-band sampler system. The NRAO operates the 43 m telescope according to schedules authored by Lincoln Laboratories. Currently the 43 m telescope is tracking spacecraft 48 hr a week. The tracking antenna operation is completely automated. A group at MIT/Haystack have installed a second radar experiment at the 43 m as well as an array of 6 ‘discone’ antennas. Their experiment is testing the use of reflected FM radio stations as probes of the ionosphere.

  11. Authentication of beef versus horse meat using 60 MHz 1H NMR spectroscopy.

    PubMed

    Jakes, W; Gerdova, A; Defernez, M; Watson, A D; McCallum, C; Limer, E; Colquhoun, I J; Williamson, D C; Kemsley, E K

    2015-05-15

    This work reports a candidate screening protocol to distinguish beef from horse meat based upon comparison of triglyceride signatures obtained by 60 MHz (1)H NMR spectroscopy. Using a simple chloroform-based extraction, we obtained classic low-field triglyceride spectra from typically a 10 min acquisition time. Peak integration was sufficient to differentiate samples of fresh beef (76 extractions) and horse (62 extractions) using Naïve Bayes classification. Principal component analysis gave a two-dimensional "authentic" beef region (p=0.001) against which further spectra could be compared. This model was challenged using a subset of 23 freeze-thawed training samples. The outcomes indicated that storing samples by freezing does not adversely affect the analysis. Of a further collection of extractions from previously unseen samples, 90/91 beef spectra were classified as authentic, and 16/16 horse spectra as non-authentic. We conclude that 60 MHz (1)H NMR represents a feasible high-throughput approach for screening raw meat.

  12. Accurate Polarization Calibration at 800 MHz with the Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Liao, Yu-Wei; Chang, Tzu-Ching; Kuo, Cheng-Yu; Masui, Kiyoshi Wesley; Oppermann, Niels; Pen, Ue-Li; Peterson, Jeffrey B.

    2016-12-01

    Polarization leakage of foreground synchrotron emission is a critical issue in H i intensity mapping experiments. While the sought-after H i emission is unpolarized, polarized foregrounds such as Galactic and extragalactic synchrotron radiation, if coupled with instrumental impurity, can mimic or overwhelm the H i signals. In this paper, we present the methodology for polarization calibration at 700-900 MHz, applied on data obtained from the Green Bank Telescope (GBT). We use astrophysical sources, both polarized and unpolarized sources including quasars and pulsars, as calibrators to characterize the polarization leakage and control systematic effects in our GBT H i intensity mapping project. The resulting fractional errors on polarization measurements on boresight are well controlled to within 0.6%-0.8% of their total intensity. The polarized beam patterns are measured by performing spider scans across both polarized quasars and pulsars. A dominant Stokes I to V leakage feature and secondary features of Stokes I to Q and I to U leakages in the 700-900 MHz frequency range are identified. These characterizations are important for separating foreground polarization leakage from the H i 21 cm signal.

  13. Direct-written polymer field-effect transistors operating at 20 MHz

    NASA Astrophysics Data System (ADS)

    Perinot, Andrea; Kshirsagar, Prakash; Malvindi, Maria Ada; Pompa, Pier Paolo; Fiammengo, Roberto; Caironi, Mario

    2016-12-01

    Printed polymer electronics has held for long the promise of revolutionizing technology by delivering distributed, flexible, lightweight and cost-effective applications for wearables, healthcare, diagnostic, automation and portable devices. While impressive progresses have been registered in terms of organic semiconductors mobility, field-effect transistors (FETs), the basic building block of any circuit, are still showing limited speed of operation, thus limiting their real applicability. So far, attempts with organic FETs to achieve the tens of MHz regime, a threshold for many applications comprising the driving of high resolution displays, have relied on the adoption of sophisticated lithographic techniques and/or complex architectures, undermining the whole concept. In this work we demonstrate polymer FETs which can operate up to 20 MHz and are fabricated by means only of scalable printing techniques and direct-writing methods with a completely mask-less procedure. This is achieved by combining a fs-laser process for the sintering of high resolution metal electrodes, thus easily achieving micron-scale channels with reduced parasitism down to 0.19 pF mm‑1, and a large area coating technique of a high mobility polymer semiconductor, according to a simple and scalable process flow.

  14. A 200 MHz 35 MW Multiple Beam Klystron for Accelerator Applications Final Report

    SciTech Connect

    R. Lawrence Ives; Michael Read; Patrick Ferguson; David Marsden

    2011-11-28

    Calabazas Creek Research, Inc. (CCR) performed initial development of a compact and reliable 35 MW, multiple beam klystron (MBK) at 200 MHz with a pulse length of 0.125 ms and a 30 Hz repetition rate. The device was targeted for acceleration and ionization cooling of a muon collider, but there are several other potential applications in this frequency range. The klystron uses multiple beams propagating in individual beam tunnels to reduce space charge and allow reduction in the accelerating voltage. This allows a significant reduction in length over a single beam source. More importantly this allows more efficient and less expensive power supplies. At 200 MHz, the interaction circuit for a single beam klystron would be more than six meters long to obtain 50% efficiency and 50 dB gain. This would require a beam voltage of approximately 400 kV and current of 251 A for a microperveance of 1.0. For an eight beam MBK with the same beam perveance, a three meter long interaction circuit achieves the same power and gain. Each beam operates at 142 kV and 70A. The Phase I demonstrated that this device could be fabricated with funding available in a Phase II program and could achieve the program specifications.

  15. Architecture and design of a 500-MHz gallium-arsenide processing element for a parallel supercomputer

    NASA Technical Reports Server (NTRS)

    Fouts, Douglas J.; Butner, Steven E.

    1991-01-01

    The design of the processing element of GASP, a GaAs supercomputer with a 500-MHz instruction issue rate and 1-GHz subsystem clocks, is presented. The novel, functionally modular, block data flow architecture of GASP is described. The architecture and design of a GASP processing element is then presented. The processing element (PE) is implemented in a hybrid semiconductor module with 152 custom GaAs ICs of eight different types. The effects of the implementation technology on both the system-level architecture and the PE design are discussed. SPICE simulations indicate that parts of the PE are capable of being clocked at 1 GHz, while the rest of the PE uses a 500-MHz clock. The architecture utilizes data flow techniques at a program block level, which allows efficient execution of parallel programs while maintaining reasonably good performance on sequential programs. A simulation study of the architecture indicates that an instruction execution rate of over 30,000 MIPS can be attained with 65 PEs.

  16. Exposure to 1800 MHz radiofrequency radiation induces oxidative damage to mitochondrial DNA in primary cultured neurons.

    PubMed

    Xu, Shangcheng; Zhou, Zhou; Zhang, Lei; Yu, Zhengping; Zhang, Wei; Wang, Yuan; Wang, Xubu; Li, Maoquan; Chen, Yang; Chen, Chunhai; He, Mindi; Zhang, Guangbin; Zhong, Min

    2010-01-22

    Increasing evidence indicates that oxidative stress may be involved in the adverse effects of radiofrequency (RF) radiation on the brain. Because mitochondrial DNA (mtDNA) defects are closely associated with various nervous system diseases and mtDNA is particularly susceptible to oxidative stress, the purpose of this study was to determine whether radiofrequency radiation can cause oxidative damage to mtDNA. In this study, we exposed primary cultured cortical neurons to pulsed RF electromagnetic fields at a frequency of 1800 MHz modulated by 217 Hz at an average special absorption rate (SAR) of 2 W/kg. At 24 h after exposure, we found that RF radiation induced a significant increase in the levels of 8-hydroxyguanine (8-OHdG), a common biomarker of DNA oxidative damage, in the mitochondria of neurons. Concomitant with this finding, the copy number of mtDNA and the levels of mitochondrial RNA (mtRNA) transcripts showed an obvious reduction after RF exposure. Each of these mtDNA disturbances could be reversed by pretreatment with melatonin, which is known to be an efficient antioxidant in the brain. Together, these results suggested that 1800 MHz RF radiation could cause oxidative damage to mtDNA in primary cultured neurons. Oxidative damage to mtDNA may account for the neurotoxicity of RF radiation in the brain.

  17. A 140 GHz pulsed EPR/212 MHz NMR spectrometer for DNP studies.

    PubMed

    Smith, Albert A; Corzilius, Björn; Bryant, Jeffrey A; DeRocher, Ronald; Woskov, Paul P; Temkin, Richard J; Griffin, Robert G

    2012-10-01

    We described a versatile spectrometer designed for the study of dynamic nuclear polarization (DNP) at low temperatures and high fields. The instrument functions both as an NMR spectrometer operating at 212 MHz ((1)H frequency) with DNP capabilities, and as a pulsed-EPR operating at 140 GHz. A coiled TE(011) resonator acts as both an NMR coil and microwave resonator, and a double balanced ((1)H, (13)C) radio frequency circuit greatly stabilizes the NMR performance. A new 140 GHz microwave bridge has also been developed, which utilizes a four-phase network and ELDOR channel at 8.75 GHz, that is then multiplied and mixed to obtain 140 GHz microwave pulses with an output power of 120 mW. Nutation frequencies obtained are as follows: 6 MHz on S=1/2 electron spins, 100 kHz on (1)H, and 50 kHz on (13)C. We demonstrate basic EPR, ELDOR, ENDOR, and DNP experiments here. Our solid effect DNP results demonstrate an enhancement of 144 and sensitivity gain of 310 using OX063 trityl at 80 K and an enhancement of 157 and maximum sensitivity gain of 234 using Gd-DOTA at 20 K, which is significantly better performance than previously reported at high fields (≥3 T).

  18. Quasi-periodic (~mHz) dayside auroral brightennings associated with high-speed solar wind

    NASA Astrophysics Data System (ADS)

    Liou, K.

    2013-12-01

    It has been reported that dayside auroral pulsations of a few mHz frequency can occur when variations of solar wind dynamic pressure at the same frequency appear. Magnetospheric compression/decompression is attributed to the auroral pulsations. Here we report another type of dayside auroral pulsations not associated with solar wind dynamic pressure changes by using global auroral images acquired from the Ultraviolet Imager (UVI) on board the Polar satellite. From one periodic (~2 - 8 mHz) auroral event that occurred on February 8, 2000, it is found that the auroral enhancements covered most of the day (~05 - 16 MLT) sector and did not show a latitudinal dependence. Based on in situ particle data from DMSP SSJ/4, the brightennings were associated mainly with enhanced particle precipitations from the central plasma sheet (i.e., diffuse aurora). There was no geomagnetic pulsation on the ground and in the dawn sector of the magnetosheath as indicated by the Geotail measurements. While the auroral pulsations occurred during high solar wind speed (> 600 km/s), they commenced when the interplanetary magnetic field turned northward, suggesting the Kelvin-Helmholtz instability being a source of the pulsations. We will present detail analysis results and discuss other possible mechanisms in the context of current theories.

  19. Cryogenic sub-system for the 56 MHz SRF storage cavity for RHIC

    SciTech Connect

    Huang, Y.; Than, R.; Orfin, P.; Lederle, D.; Tallerico, T.; Masi L.; Talty, P.; Zhang, Y.

    2011-03-28

    A 56 MHz Superconducting RF Storage Cavity is being constructed for the RHIC collider. This cavity is a quarter wave resonator that will be operated in a liquid helium bath at 4.4 K. The cavity requires an extremely quiet environment to maintain its operating frequency. The cavity, besides being engineered for a mechanically quiet system, also requires a quiet cryogenic system. The helium is taken from RHIC's main helium supply header at 3.5 atm, 5.3K at a phase separator tank. The boil-off is sent back to the RHIC refrigeration system to recover the cooling. To acoustically separate the RHIC helium supply and return lines, a condenser/boiler heat exchanger condenses the helium vapor generated in the RF cavity bath. A system description and operating parameters are given about the cryogen delivery system. The 56 MHz superconducting storage RF cavity project is making progress. The cryogenic system design is in its final stage. The helium supply lines have been tapped into the RHIC helium distribution lines. The plate-and-fin heat exchanger design is near completion and specification will be sent out for bid soon. The cold helium vapor heating system design will start soon as well. A booster compressor specification is underway. The first phase separator and transfer line design work is near completion and will be sent out for bid soon.

  20. Orthogonal resonators for pulse in vivo electron paramagnetic imaging at 250 MHz

    PubMed Central

    Sundramoorthy, Subramanian V.; Epel, Boris; Halpern, Howard J.

    2014-01-01

    A 250 MHz bimodal resonator with a 19 mm internal diameter for in vivo pulse electron paramagnetic resonance (EPR) imaging is presented. Two separate coaxial cylindrical resonators inserted one into another were used for excitation and detection. The Alderman-Grant excitation resonator (AGR) showed the highest efficiency among all the excitation resonators tested. The magnetic field of AGR is confined to the volume of the detection resonator, which results in highly efficient use of the radio frequency power. A slotted inner single loop single gap resonator (SLSG LGR), coaxial to the AGR, was used for signal detection. The resulting bimodal resonator (AG/LGR) has two mutually orthogonal magnetic field modes; one of them has the magnetic field in the axial direction. The resonator built in our laboratory achieved 40dB isolation over 20 MHz bandwidth with quality factors of detection and excitation resonators of 36 and 11 respectively. Considerable improvement of the B1 homogeneity and EPR image quality in comparison with reflection loop-gap resonator of similar size and volume was observed. PMID:24530507