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Sample records for 2110-2155 mhz 2160-2180

  1. 47 CFR 27.1176 - Cost-sharing requirements for AWS in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the...) Frequencies in the 2150-2160/62 MHz band have been reallocated from the Broadband Radio Service (BRS) to...

  2. 47 CFR 27.1176 - Cost-sharing requirements for AWS in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the...) Frequencies in the 2150-2160/62 MHz band have been reallocated from the Broadband Radio Service (BRS) to...

  3. 47 CFR 27.1176 - Cost-sharing requirements for AWS in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the...) Frequencies in the 2150-2160/62 MHz band have been reallocated from the Broadband Radio Service (BRS) to...

  4. 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...

  5. 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...

  6. 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...

  7. 47 CFR 27.1190 - Termination of cost-sharing obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band §...

  8. 47 CFR 27.1190 - Termination of cost-sharing obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band §...

  9. 47 CFR 27.1174 - Termination of Cost-Sharing Obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands... Broadband Radio Service Relocation From the 2150-2160/62 MHz Band Source: Sections 27.1176 through...

  10. 47 CFR 27.1190 - Termination of cost-sharing obligations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band §...

  11. 47 CFR 27.1174 - Termination of Cost-Sharing Obligations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands... Broadband Radio Service Relocation From the 2150-2160/62 MHz Band Source: Sections 27.1176 through...

  12. 47 CFR 27.1174 - Termination of Cost-Sharing Obligations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands... Broadband Radio Service Relocation From the 2150-2160/62 MHz Band Source: Sections 27.1176 through...

  13. 47 CFR 27.1182 - Reimbursement under the Cost-Sharing Plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band §...

  14. 47 CFR 27.1182 - Reimbursement under the Cost-Sharing Plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band §...

  15. 47 CFR 27.1188 - Dispute resolution under the Cost-Sharing Plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62...

  16. 47 CFR 27.1178 - Administration of the Cost-Sharing Plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band § 27.1178 Administration of the Cost-Sharing Plan. The Wireless Telecommunications Bureau, under...

  17. 47 CFR 27.1178 - Administration of the Cost-Sharing Plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band § 27.1178 Administration of the Cost-Sharing Plan. The Wireless Telecommunications Bureau, under...

  18. 47 CFR 27.1131 - Protection of Part 101 operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Protection of Part 101 operations. 27.1131... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Protection of Incumbent Operations § 27.1131 Protection of Part 101 operations. All AWS licensees, prior to...

  19. 47 CFR 27.1131 - Protection of Part 101 operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Protection of Part 101 operations. 27.1131... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2160-2180 MHz Bands Protection of Incumbent Operations § 27.1131 Protection of Part 101 operations. All AWS licensees, prior to...

  20. 47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... relocation, such as system-wide relocations and analog-to-digital conversions, versus other types of premiums... provide the PARS licensee with an equivalent number of 4 kHz voice channels. If digital facilities are being replaced with digital, the ET licensee must provide the PARS licensee with equivalent data...

  1. 47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... relocation, such as system-wide relocations and analog-to-digital conversions, versus other types of premiums... provide the PARS licensee with an equivalent number of 4 kHz voice channels. If digital facilities are being replaced with digital, the ET licensee must provide the PARS licensee with equivalent data...

  2. 47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... relocation, such as system-wide relocations and analog-to-digital conversions, versus other types of premiums... provide the PARS licensee with an equivalent number of 4 kHz voice channels. If digital facilities are being replaced with digital, the ET licensee must provide the PARS licensee with equivalent data...

  3. 47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... relocation, such as system-wide relocations and analog-to-digital conversions, versus other types of premiums... provide the PARS licensee with an equivalent number of 4 kHz voice channels. If digital facilities are being replaced with digital, the ET licensee must provide the PARS licensee with equivalent data...

  4. 47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... relocation, such as system-wide relocations and analog-to-digital conversions, versus other types of premiums... provide the PARS licensee with an equivalent number of 4 kHz voice channels. If digital facilities are being replaced with digital, the ET licensee must provide the PARS licensee with equivalent data...

  5. 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

    ... business is an entity that, together with its affiliates, its controlling interests and the affiliates of its controlling interests, has average gross revenues that are not more than $40 million for the... controlling interests and the affiliates of its controlling interests, has average gross revenues that are...

  6. 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

    ... business is an entity that, together with its affiliates, its controlling interests and the affiliates of its controlling interests, has average gross revenues that are not more than $40 million for the... controlling interests and the affiliates of its controlling interests, has average gross revenues that are...

  7. 47 CFR 27.1102 - Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... affiliates, its controlling interests and the affiliates of its controlling interests, has average gross... entity that, together with its affiliates, its controlling interests and the affiliates of its controlling interests, has average gross revenues that are not more than $15 million for the preceding...

  8. 47 CFR 27.1102 - Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... provisions. (1) A small business is an entity that, together with its affiliates, its controlling interests and the affiliates of its controlling interests, has average gross revenues that are not more than $40... affiliates, its controlling interests and the affiliates of its controlling interests, has average...

  9. 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

    ... business is an entity that, together with its affiliates, its controlling interests and the affiliates of its controlling interests, has average gross revenues that are not more than $40 million for the... controlling interests and the affiliates of its controlling interests, has average gross revenues that are...

  10. 47 CFR 27.1182 - Reimbursement under the Cost-Sharing Plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1695-1710 MHz, 1710-1755 MHz, 1755-1780 MHz, 2110-2155 MHz, 2155-2180 MHz, 2180-2200 MHz Bands Cost-Sharing Policies Governing Broadband Radio...

  11. 47 CFR 27.1188 - Dispute resolution under the Cost-Sharing Plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1695-1710 MHz, 1710-1755 MHz, 1755-1780 MHz, 2110-2155 MHz, 2155-2180 MHz, 2180-2200 MHz Bands Cost-Sharing Policies Governing Broadband...

  12. 47 CFR 27.1190 - Termination of cost-sharing obligations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1695-1710 MHz, 1710-1755 MHz, 1755-1780 MHz, 2110-2155 MHz, 2155-2180 MHz, 2180-2200 MHz Bands Cost-Sharing Policies Governing Broadband Radio...

  13. 47 CFR 27.1182 - Reimbursement under the Cost-Sharing Plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2000-2020 MHz, and 2180-2200 MHz bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the...

  14. 47 CFR 27.1190 - Termination of cost-sharing obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2000-2020 MHz, and 2180-2200 MHz bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the...

  15. 47 CFR 27.1188 - Dispute resolution under the Cost-Sharing Plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2000-2020 MHz, and 2180-2200 MHz bands Cost-Sharing Policies Governing Broadband Radio Service Relocation...

  16. 47 CFR 27.1174 - Termination of cost-sharing obligations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2000-2020 MHz, and... sunset date must satisfy their payment obligation in full. Cost-Sharing Policies Governing...

  17. 47 CFR 27.1178 - Administration of the Cost-Sharing Plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1695-1710 MHz, 1710-1755 MHz, 1755-1780 MHz, 2110-2155 MHz, 2155-2180 MHz, 2180-2200 MHz Bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band § 27.1178 Administration of the Cost-Sharing Plan. The...

  18. 47 CFR 27.1178 - Administration of the Cost-Sharing Plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz, 2000-2020 MHz, and 2180-2200 MHz bands Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band § 27.1178 Administration of the Cost-Sharing Plan. The Wireless...

  19. 47 CFR 27.1133 - Protection of Part 74 and Part 78 operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Protection of Part 74 and Part 78 operations. 27.1133 Section 27.1133 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz,...

  20. 47 CFR 27.1133 - Protection of Part 74 and Part 78 operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Protection of Part 74 and Part 78 operations. 27.1133 Section 27.1133 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155 MHz,...

  1. 500 MHz neutron detector

    SciTech Connect

    Yen, Yi-Fen; Bowman, J.D.; Matsuda, Y.

    1993-12-01

    A {sup 10}B-loaded scintillation detector was built for neutron transmission measurements at the Los Alamos Neutron Scattering Center. The efficiency of the detector is nearly 100% for neutron energies from 0 to 1 keV. The neutron moderation time in the scintillator is about 250 ns and is energy independent. The detector and data processing system are designed to handle an instantaneous rate as high as 500 MHz. The active area of the detector is 40 cm in diameter.

  2. Multi-MHz retinal OCT

    PubMed Central

    Klein, Thomas; Wieser, Wolfgang; Reznicek, Lukas; Neubauer, Aljoscha; Kampik, Anselm; Huber, Robert

    2013-01-01

    We analyze the benefits and problems of in vivo optical coherence tomography (OCT) imaging of the human retina at A-scan rates in excess of 1 MHz, using a 1050 nm Fourier-domain mode-locked (FDML) laser. Different scanning strategies enabled by MHz OCT line rates are investigated, and a simple multi-volume data processing approach is presented. In-vivo OCT of the human ocular fundus is performed at different axial scan rates of up to 6.7 MHz. High quality non-mydriatic retinal imaging over an ultra-wide field is achieved by a combination of several key improvements compared to previous setups. For the FDML laser, long coherence lengths and 72 nm wavelength tuning range are achieved using a chirped fiber Bragg grating in a laser cavity at 419.1 kHz fundamental tuning rate. Very large data sets can be acquired with sustained data transfer from the data acquisition card to host computer memory, enabling high-quality averaging of many frames and of multiple aligned data sets. Three imaging modes are investigated: Alignment and averaging of 24 data sets at 1.68 MHz axial line rate, ultra-dense transverse sampling at 3.35 MHz line rate, and dual-beam imaging with two laser spots on the retina at an effective line rate of 6.7 MHz. PMID:24156052

  3. Aircraft measurement of radio frequency noise at 121.5 MHz, 243MHz and 406MHz

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    An airborne survey measurement of terrestrial radio-frequency noise over U.S. metropolitan areas has been made at 121.5, 243 and 406 MHz with horizontal-polarization monopole antennas. Flights were at 25,000 feet altitude during the period from December 30, 1976 to January 8, 1977. Radio-noise measurements, expressed in equivalent antenna-noise temperature, indicate a steady-background noise temperature of 572,000 K, at 121.5 MHz, during daylight over New York City. This data is helpful in compiling radio-noise temperature maps; in turn useful for designing satellite-aided, emergency-distress search and rescue communication systems.

  4. 47 CFR 27.501 - 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false 746-763 MHz, 775-793 MHz, and 805-806 MHz bands... Procedures for the 698-806 MHz Band § 27.501 746-763 MHz, 775-793 MHz, and 805-806 MHz bands subject to competitive bidding. Mutually exclusive initial applications for licenses in the 746-763 MHz, 775-793 MHz,...

  5. 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).

  6. New OH masers at 13 441 MHz

    NASA Astrophysics Data System (ADS)

    Caswell, J. L.

    2004-07-01

    The Parkes radio telescope has been used to study maser emission from the 13441-MHz transition of highly excited OH. The targets were 56 catalogued sites of 6035-MHz maser emission. Eight 13441-MHz maser sites were detected, six of them new and two that had previously been reported. This more than doubles the number now known to 11. At every 13441-MHz maser site, spectral features occur as right- and left-hand circularly polarized matched pairs, with small, but mostly significant, frequency separation. This is attributed to the Zeeman effect in magnetic fields of a few mG. Some of the 13441-MHz maser sites show features at several different velocities. All of the 13441-MHz maser features have 6035-MHz counterparts that closely correspond in velocity. At three sites, features of 13441-MHz emission rival the intensities of their 6035-MHz counterparts; at the other sites, features are weaker than at 6035 MHz by factors of between 3 and 50. Upper limits at some sites searched can be set more than 2 orders of magnitude weaker than 6035-MHz emission. The detection statistics provide unique opportunities to test recent advances in maser modelling. A search for the 13434-MHz transition towards the same 56 targets yielded no detections.

  7. A low noise 500 MHz frequency source

    NASA Astrophysics Data System (ADS)

    Vulcan, A.; Bloch, M.; Tanski, W.

    A low-noise signal source providing multiple 500 MHz and 400 MHz outputs is presented whose noise characteristics approach the thermal limit at frequencies spaced greater than 1 MHz from the carrier. The unit uses bulk and surface acoustic wave resonators to insure low phase noise and spurious outputs and is totally redundant for failsafe operation. The packaging concept minimizes subassembly interconnections and provides both physical and electrical independence of two redundant generators; package shielding insures minimum conducted and radiated susceptibility.

  8. 47 CFR 101.79 - Sunset provisions for licensees in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... incumbent, as determined by TIA TSB 10-F (for terrestrial-to-terrestrial situations) or TIA TSB 86 (for MSS... determined as follows: (1) For the 2110-2150 MHz and 2160-2175 MHz and 2175-2180 MHz bands, ten years after the first ET license is issued in the respective band; and (2) For the 2180-2200 MHz band, for...

  9. 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

  10. A 50 MHz System for GMRT

    NASA Astrophysics Data System (ADS)

    Udaya Shankar, N.; Dwarakanath, K. S.; Amiri, S.; Somashekar, R.; Girish, B. S.; Laus, W.; Nayak, A.

    2009-09-01

    This paper describes a 50~MHz system being developed for GMRT to provide imaging capability in the frequency range 30-90~MHz. Due to its larger collecting area and higher antenna efficiency, the low-frequency GMRT system will be several times more sensitive than the present 74~MHz VLA system and is likely to remain a competitive instrument in this frequency band. In the first phase of this project, receiver systems consisting of V-dipole feeds and front-ends have been installed on four of the thirty GMRT antennas. Test observations were carried out on a number of bright 3CR sources. The initial results are encouraging. This paper will also describe results of simultaneous observations carried out using the existing GMRT correlator, the new GMRT software correlator and a system employing digitization and direct recording of signals at two antenna bases.

  11. Nonthermal galactic emission below 10 MHz

    NASA Technical Reports Server (NTRS)

    Novaco, J. C.; Brown, L. W.

    1977-01-01

    The Radio Astronomy Explorer-2 (RAE-2) satellite has provided new measurements of the nonthermal galactic radio emission at frequencies below 10 MHz. Measurements of the emission spectra are presented for the center, anticenter, north polar, and south polar directions at 22 frequencies between 0.25 and 9.18 MHz. Survey maps of the spatial distribution of the observed low frequency galactic emission at 1.31, 2.20, 3.93, 4.70, 6.55, and 9.18 MHz are presented. The observations were obtained with the 229-meter traveling-wave V-antenna on this lunar orbiting spacecraft. The improved frequency coverage offers additional insights into structure of the local galactic neighborhood.

  12. Detection of new pulsars at 111 MHz

    NASA Astrophysics Data System (ADS)

    Tyul'bashev, S. A.; Tyul'bashev, V. S.; Oreshko, V. V.; Logvinenko, S. V.

    2016-02-01

    The first results of a search for pulsars using the Large Phased Array of the Lebedev Physical Institute at 111 MHz for right ascensions 0h-24h and declinations 21°-42° are reported. Data with a time resolution of 100 ms in six frequency channels within a 2.5-MHz frequency band have been processed. Thirty-four pulsars have been detected, of which seventeen were observed on this telescope earlier; ten known pulsars had not been observed earlier. Seven new pulsars have been discovered.

  13. 47 CFR 15.245 - Operation within the bands 902-928 MHz, 2435-2465 MHz, 5785-5815 MHz, 10500-10550 MHz, and 24075...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... limited to intentional radiators used as field disturbance sensors, excluding perimeter protection systems... field disturbance sensors operating in the 24075-24175 MHz band and for other field disturbance sensors... disturbance sensors, 7.5 mV/m. (iii) Field disturbance sensors designed to be used in motor vehicles...

  14. 47 CFR 15.245 - Operation within the bands 902-928 MHz, 2435-2465 MHz, 5785-5815 MHz, 10500-10550 MHz, and 24075...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... limited to intentional radiators used as field disturbance sensors, excluding perimeter protection systems... field disturbance sensors operating in the 24075-24175 MHz band and for other field disturbance sensors... disturbance sensors, 7.5 mV/m. (iii) Field disturbance sensors designed to be used in motor vehicles...

  15. 47 CFR 15.245 - Operation within the bands 902-928 MHz, 2435-2465 MHz, 5785-5815 MHz, 10500-10550 MHz, and 24075...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... limited to intentional radiators used as field disturbance sensors, excluding perimeter protection systems... field disturbance sensors operating in the 24075-24175 MHz band and for other field disturbance sensors... disturbance sensors, 7.5 mV/m. (iii) Field disturbance sensors designed to be used in motor vehicles...

  16. 47 CFR 15.245 - Operation within the bands 902-928 MHz, 2435-2465 MHz, 5785-5815 MHz, 10500-10550 MHz, and 24075...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... limited to intentional radiators used as field disturbance sensors, excluding perimeter protection systems... field disturbance sensors operating in the 24075-24175 MHz band and for other field disturbance sensors... disturbance sensors, 7.5 mV/m. (iii) Field disturbance sensors designed to be used in motor vehicles...

  17. 47 CFR 15.245 - Operation within the bands 902-928 MHz, 2435-2465 MHz, 5785-5815 MHz, 10500-10550 MHz, and 24075...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... limited to intentional radiators used as field disturbance sensors, excluding perimeter protection systems... field disturbance sensors operating in the 24075-24175 MHz band and for other field disturbance sensors... disturbance sensors, 7.5 mV/m. (iii) Field disturbance sensors designed to be used in motor vehicles...

  18. BLAZAR SPECTRAL PROPERTIES AT 74 MHz

    SciTech Connect

    Massaro, F.; Funk, S.; Giroletti, M.; Paggi, A.; D'Abrusco, R.; Tosti, G.

    2013-10-01

    Blazars are the most extreme class of active galactic nuclei. Despite a previous investigation at 102 MHz for a small sample of BL Lac objects and our recent analysis of blazars detected in the Westerbork Northern Sky Survey, a systematic study of the blazar spectral properties at frequencies below 100 MHz has been never carried out. In this paper, we present the first analysis of the radio spectral behavior of blazars based on the recent Very Large Array Low-frequency Sky Survey (VLSS) at 74 MHz. We search for blazar counterparts in the VLSS catalog, confirming that they are detected at 74 MHz. We then show that blazars present radio-flat spectra (i.e., radio spectral indices of ∼0.5) when evaluated, which also about an order of magnitude in frequency lower than previous analyses. Finally, we discuss the implications of our findings in the context of the blazars-radio galaxies connection since the low-frequency radio data provide a new diagnostic tool to verify the expectations of the unification scenario for radio-loud active galaxies.

  19. 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

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transition of the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands from the fixed microwave services to personal communications services and emerging technologies. 101.69 Section 101.69 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES...

  20. 47 CFR 101.79 - Sunset provisions for licensees in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Sunset provisions for licensees in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands. 101.79 Section 101.79 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers,...

  1. 47 CFR 101.79 - Sunset provisions for licensees in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Sunset provisions for licensees in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands. 101.79 Section 101.79 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers,...

  2. 47 CFR 101.81 - Future licensing in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... extensions to existing FMS systems in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands will be authorized on a secondary basis to ET systems. All other modifications will render the modified FMS license... FMS licensee establishes that the modification would not add to the relocation costs of ET...

  3. 47 CFR 101.81 - Future licensing in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... extensions to existing FMS systems in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands will be authorized on a secondary basis to ET systems. All other modifications will render the modified FMS license... FMS licensee establishes that the modification would not add to the relocation costs of ET...

  4. 47 CFR 101.81 - Future licensing in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... extensions to existing FMS systems in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands will be authorized on a secondary basis to ET systems. All other modifications will render the modified FMS license... FMS licensee establishes that the modification would not add to the relocation costs of ET...

  5. 47 CFR 101.81 - Future licensing in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... extensions to existing FMS systems in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands will be authorized on a secondary basis to ET systems. All other modifications will render the modified FMS license... FMS licensee establishes that the modification would not add to the relocation costs of ET...

  6. 47 CFR 101.81 - Future licensing in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... extensions to existing FMS systems in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands will be authorized on a secondary basis to ET systems. All other modifications will render the modified FMS license... FMS licensee establishes that the modification would not add to the relocation costs of ET...

  7. 47 CFR 15.231 - Periodic operation in the band 40.66-40.70 MHz and above 70 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 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...

  8. 47 CFR 15.231 - Periodic operation in the band 40.66-40.70 MHz and above 70 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 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...

  9. 47 CFR 15.231 - Periodic operation in the band 40.66-40.70 MHz and above 70 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 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...

  10. Gyrotron FU CW VII for 300 MHz and 600 MHz DNP-NMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Idehara, Toshitaka; Kosuga, Kosuke; Agusu, La; Ogawa, Isamu; Takahashi, Hiroki; Smith, Mark E.; Dupree, Ray

    2010-07-01

    Gyrotron FU CW VII, one of the FU CW Series Gyrotrons, has been designed, constructed and completed operational tests successfully in the Research Center for Development of Far Infrared Region, University of Fukui (FIR FU). The gyrotron operates at around 200 GHz for the fundamental cyclotron resonances and at around 400 GHz for the second harmonics. These radiation frequencies will be applied to 300 MHz and 600 MHz DNP enhanced NMR spectroscopy.

  11. 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.

  12. 47 CFR 15.233 - Operation within the bands 43.71-44.49 MHz, 46.60-46.98 MHz, 48.75-49.51 MHz and 49.66-50.0 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Operation within the bands 43.71-44.49 MHz, 46.60-46.98 MHz, 48.75-49.51 MHz and 49.66-50.0 MHz. 15.233 Section 15.233 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.233...

  13. 47 CFR 95.628 - MedRadio transmitters in the 413-419 MHz, 426-432 MHz, 438-444 MHz, and 451-457 MHz and 2360-2400...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Micropower Network (MMN) and in the 2360-2400 MHz band as part of a Medical Body Area Network (MBAN). (a... not exceed 6 MHz. (c) Requirements for Medical Body Area Networks. A MedRadio programmer/control... operate in the 2360-2400 MHz frequency band. (b) Requirements for a Medical Micropower Network....

  14. 47 CFR 95.628 - MedRadio transmitters in the 413-419 MHz, 426-432 MHz, 438-444 MHz, and 451-457 MHz and 2360-2400...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Micropower Network (MMN) and in the 2360-2400 MHz band as part of a Medical Body Area Network (MBAN). (a... not exceed 6 MHz. (c) Requirements for Medical Body Area Networks. A MedRadio programmer/control... operate in the 2360-2400 MHz frequency band. (b) Requirements for a Medical Micropower Network....

  15. BNl 703 MHz superconducting RF cavity testing

    SciTech Connect

    Sheehy, B.; Altinbas, Z.; Burrill, A.; Ben-Zvi, I.; Gassner, D.; Hahn, H.; Hammons, L.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Laloudakis, N.; Lederle, D.; Litvinenko, V.; McIntyre, G.; Pate, D.; Phillips, D.; Schultheiss, C.; Seda,T.; Than, R.; Xu, W.; Zaltsman, A.; Schultheiss, T.

    2011-03-28

    The BNL 5-cell, 703 MHz superconducting accelerating cavity has been installed in the high-current ERL experiment. This experiment will function as a proving ground for the development of high-current machines in general and is particularly targeted at beam development for an electron-ion collider (eRHIC). The cavity performed well in vertical tests, demonstrating gradients of 20 MV/m and a Q{sub 0} of 1e10. Here we will present its performance in the horizontal tests, and discuss technical issues involved in its implementation in the ERL.

  16. 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.

  17. Waveguide ultrasonic force microscopy at 60 MHz

    NASA Astrophysics Data System (ADS)

    Inagaki, K.; Kolosov, O. V.; Briggs, G. A. D.; Wright, O. B.

    2000-04-01

    We present measurements using ultrasonic force microscopy at ˜60 MHz, operating in a "waveguide" mode in which the cantilever base is vibrated and flexural ultrasonic vibrations are launched down the cantilever without exciting any particular cantilever resonance. The nonlinearity of the tip-sample force-distance curve allows the conversion of a modulated ultrasonic frequency into a low frequency vibration of the cantilever, detected in a conventional atomic force microscope. Images of Ge quantum dots on a Si substrate show contrast related to elasticity and adhesion differences, and this is interpreted with the Johnson-Kendall-Roberts model of the force-distance curve.

  18. 76 FR 11681 - Improving Public Safety Communications in the 800 MHz Band; New 800 MHz Band Plan for Puerto Rico...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ...This document summarizes the Fourth Report and Order, which establishes a new 800 MHz band plan for the U.S. Virgin Islands (USVI). This action is necessary to meet the Commission's goals to improve public safety communications in the 800 MHz band. The effect of this order ensures an orderly and efficient transition to the new 800 MHz band plan in the...

  19. Spectral behavior of Jupiter near 1 MHz

    NASA Technical Reports Server (NTRS)

    Brown, L. W.

    1974-01-01

    Emission from Jupiter has been observed by the IMP-6 spacecraft at 25 frequencies between 425 and 9900 kHz covering the period April 1971 to October 1972. The Jovian bursts were identified through the phase of the observed modulated signal detected from the spinning dipole antenna. Approximately 500 days of data have been scanned for Jupiter emissions with a positive detection of at least 382 events. The static spectral behavior of the emission has been investigated and can be divided naturally into three types. Type one (normal) shows a high correlation with earth-based observations and follows the same spectral behavior. These bursts are seldom detected much below 1 MHz. The second type (md-frequency) occurs near or below 1 MHz and shows low and high-frequency cutoffs. The emission peak is near 900 kHz with a 3 db bandwidth of approximately 450 kHz. A third type consists of a complex combination of the previous types.

  20. 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.

  1. A Four Channel 250 MHz Visual Counter

    SciTech Connect

    Flores, I.; Blando, P.; Crawford, H.; Engelage, J.; Greiner, L.; Ko, S.; Krebs, G.; Visser, G.

    1992-04-01

    A visual counter rated at 250 mhz. with a pulse-pair resolution of 2.6 nanoseconds for nuclear instrument module (NIM) signals has been designed. Pulse widths for NIM signals must be equal to or greater than 2 ns. The counter has a separate input for transistor-transistor logic (TTL) signals and for this logic level it operates at rates equal to or less than 190 mhz. TTL pulses must be greater than 4 ns. The design was implemented on a printed circuit card. Four of these cards were packaged into a single unit resulting in a four channel device that can be mounted into a 19 inch rack. Seven units were built; they are presently used in the experimental area and in the Main Control Room of the Bevalac. The counter accepts well defined NIM or TTL signals internally terminated with 50 ohms. All the controls and the signal input connectors are located on the front panel. An Overflow output, Gate, and Reset inputs are located on the back panel. The counters have 8 Light Emitting Diode digit displays which are 20.3 mm high with a viewing distance rating of 10 meters. Light filters are used for the LED displays greatly enhancing their visibility.

  2. 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.

  3. 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.

  4. 47 CFR 90.176 - Coordinator notification requirements on frequencies below 512 MHz, at 769-775/799-805 MHz, or at...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... frequencies below 512 MHz, at 769-775/799-805 MHz, or at 1427-1432 MHz. 90.176 Section 90.176... requirements on frequencies below 512 MHz, at 769-775/799-805 MHz, or at 1427-1432 MHz. (a) Frequencies below... Public Safety Pool and the Industrial/Business Pool. (c) Frequencies in the 769-775/799-805 MHz...

  5. 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...

  6. 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... synchronization with the transmitted signals. (i) For frequency hopping systems operating in the 902-928 MHz band... bandwidth of the hopping channel is 500 kHz. (ii) Frequency hopping systems operating in the 5725-5850...

  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, 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...

  8. 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...

  9. 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...

  10. RHIC 28 MHZ ACCELERATING CAVITY SYSTEM.

    SciTech Connect

    ROSE,J.; BRENNAN,J.M.; CAMPBELL,A.; KWIATKOWSKI,S.; RATTI,A.; PIRKL,W.

    2001-06-18

    The 28 MHz accelerating system consists of a quarter wave cavity driven by an inductively coupled 100kW tetrode amplifer and 1kW solid state driver amplifer. 40dB of rf feedback closed around the cavity and amplifers reduces small perturbations within the loop by a factor of 100, and reduces the time required to shift the phase at transition by a factor of 10, limited by the saturation of the drive chain. The cavity is tuned over a 200kHz range by a mechanical tuner which varies the gap capacitance. Broadband HOM damping is provided by two orthogonal loop coupled high pass filters. Design parameters and commissioning results are presented.

  11. 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.

  12. 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.

  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. Upgrading the LAMPF 201 MHz RF generators

    SciTech Connect

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

    1993-04-01

    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 series-connected, vacuum-tube amplifiers. The first amplifier is a grid-modulated tetrode that produces 500 W peak-power. The second amplifier is a drivemodulated tetrode that produces 5 kW peak-power. The third stage is a grid- and plate-modulated tetrode that produces 130 kW 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.

  15. Upgrading the LAMPF 201 MHz RF generators

    SciTech Connect

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

    1993-01-01

    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 series-connected, vacuum-tube amplifiers. The first amplifier is a grid-modulated tetrode that produces 500 W peak-power. The second amplifier is a drivemodulated tetrode that produces 5 kW peak-power. The third stage is a grid- and plate-modulated tetrode that produces 130 kW 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.

  16. 10- to 1800-MHz Dielectric Spectroscopy of Eggs in Storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dielectric constant and loss factor of egg albumen and egg yolk during 5 weeks of storage at 15 degrees C were measured at 24 degrees C over the frequency range from 10 MHz to 1800 MHz. Moisture and ash contents of albumen and yolk, as well as Haugh unit and yolk index were also measured. The di...

  17. Simultaneous Observations of Giant Pulses from Pulsar PSR B0950+08 at 42 MHz and 74 MHz

    NASA Astrophysics Data System (ADS)

    Tsai, -Wei, Jr.; Simonetti, John H.; Akukwe, Bernadine; Bear, Brandon; Gough, Jonathan D.; Shawhan, Peter; Kavic, Michael

    2016-02-01

    We report the detection of giant pulse (GP) emission from PSR B0950+08 in 12 hr of observations made simultaneously at 42 and 74 MHz, using the first station of the Long Wavelength Array. We detected 275 GPs (in 0.16% of the pulse periods) and 465 GPs (0.27%) at 42 and 74 MHz, respectively. The pulsar is weaker and produces less frequent GPs than at 100 MHz. Here, GPs are taken as having ≥slant 10 times the flux density of an average pulse (AP); their cumulative distribution of pulse strength follows a power law, with an index of -4.1 at 42 MHz and -5.1 at 74 MHz, which is much less steep than would be expected if we were observing the tail of a Gaussian distribution of normal pulses. We detected no other transient pulses in a wide dispersion measure range from 1 to 5000 pc cm-3. There were 128 GPs detected within the same periods from both 42 and 74 MHz, which means more than half of them are not generated in a wide band. The CLEAN-based algorithm was used to deconvolve the the effect of scattering broadening and we have concluded that the scattering effect from the interstellar medium at 42 and 74 MHz is weak and cannot be distinguished from the pulse profiles. We calculated the altitude r of the emission region using the dipolar magnetic field model. We found r(42 MHz) = 29.27 km (0.242% of RLC) and r(74 MHz) = 29.01 km (0.240% of RLC) for the AP, while for GPs, r(42 MHz) = 29.10 km (0.241% of RLC) and r(74 MHz) = 28.95 km (0.240% of RLC). GPs, which have a double-peak structure, have a smaller mean peak-to-peak separation compared to the AP.

  18. 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...

  19. 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.

  20. 47 CFR 15.231 - Periodic operation in the band 40.66-40.70 MHz and above 70 MHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Periodic operation in the band 40.66-40.70 MHz and above 70 MHz. 15.231 Section 15.231 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.231 Periodic operation in the band 40.66-40.70...

  1. 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 and above 70 MHz. 15.231 Section 15.231 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators Radiated Emission Limits, Additional Provisions § 15.231 Periodic operation in the band 40.66-40.70...

  2. Simultaneous Observations of Giant Pulses from Pulsar PSR B0031-07 AT 38 MHz AND 74 MHz

    NASA Astrophysics Data System (ADS)

    Tsai, Jr-Wei; Simonetti, John H.; Bear, Brandon; Gough, Jonathan D.; Newton, Joseph R.; Kavic, Michael

    2016-03-01

    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-3. No other transient pulses were detected in the data in the wide DM range from 1 to 5000 pc cm-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.

  3. 75 FR 56533 - Wireless Telecommunications Bureau Postpones Auction of 218-219 MHz Service and Phase II 220 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... COMMISSION Wireless Telecommunications Bureau Postpones Auction of 218-219 MHz Service and Phase II 220 MHz... document announces the postponement of Auction 89. FOR FURTHER INFORMATION CONTACT: Wireless... related documents are also available on the Internet at the Commission's Web site:...

  4. 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

  5. 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.

  6. Performance evaluation of wearable wireless body area networks during walking motions in 444.5 MHz and 2450 MHz.

    PubMed

    Takizawa, Kenichi; Watanabe, Katsuhiro; Kumazawa, Masaki; Hamada, Yusuke; Ikegami, Tetsushi; Hamaguchi, Kiyoshi

    2010-01-01

    This paper gives performance evaluation of wearable wireless body area networks (WBANs) during walking motion. In order to evaluate the performance, received signal strength (RSS), packet error rate (PER), and bit error rate (BER) are measured in an anechoic chamber and an office room. This measurement is conducted in the frequency band of 444.5 and 2450 MHz by using GFSK signal with symbol rate of 1 MHz. The results show that in the anechoic chamber the WBAN using the 444.5 MHz enables to provide error-free communication, on the other hand, the WBAN operated in the 2450 MHz faces packet errors. Measurement results in the office room give comparable performance between these frequencies. From these observations, the use of 2450 MHz for wearable WBANs needs reflection waves in order to compensate a shadowing effect caused by the human body using the WBAN. PMID:21097187

  7. Investigation of radio astronomical windows between 1 MHz and 2060 MHz in Universiti Malaya, Malaysia

    NASA Astrophysics Data System (ADS)

    Abidin, Zamri Zainal; Ibrahim, Zainol Abidin; Adnan, Syed Bahari Ramadzan Syed; Anuar, Norwati Khairul

    2009-08-01

    An indoor and an outdoor radio frequency survey was conducted in Universiti Malaya, Malaysia, as a test site, for the purpose of developing radio astronomy research in Malaysia. This is the first radio astronomical survey of any such done in Malaysia. Observation and analysis were done in the radio frequency spectrum between 1 MHz and 2060 MHz. In this paper, the experimental setup and procedure of surveying are outlined and the measured data are interpreted. The eight radio astronomical windows were investigated from a 24 h observation, with the emphasis on two of the most important radio astronomical windows which are protected by the Malaysian Communications and Multimedia Commission (MCMC). Some intermittent observations were also done for referencing purposes. The radio frequency interferences (RFIs) are found to be relatively low. The overall relative Interference-to-Noise ratio (INR) at this test site ranges between 5.72% and 11.74%. The average strength of RFI in the eight focused radio astronomical windows at this site ranges between -100 dBm and -90 dBm (equivalently between 9.23 × 10 4 Jy and 93.29 × 10 4 Jy at resolution bandwidth of 125 kHz).

  8. Hunting for MHz gravitational waves with the Fermilab Holometer

    NASA Astrophysics Data System (ADS)

    Kamai, Brittany; The Holometer Collaboration Collaboration

    2016-03-01

    The highest frequency end of the gravitational wave spectrum remains poorly constrained. Cosmic strings and primordial black holes are potential gravitational waves candidates that could radiate at MHz frequencies. The existence of nearby sources can be tested using the Fermilab Holometer, two nested 40 meter Michelson interferometers. This instrument can achieve strain sensitivity better than 10- 20 / rt .Hz within the 1-10 MHz frequency band. The Holometer is fully operational and has taken long observational campaigns acquiring 100s of hours of science quality data. I will present results of a search for narrow-lined sources and constraints on the stochastic background in the MHz band.

  9. Equipment testing with damped sinewaves between 1 and 50 MHz

    NASA Astrophysics Data System (ADS)

    Hardwick, C. John; Baldwin, R. E.

    1992-11-01

    Present lightning equipment test standards such as RTCA DO160C call for damped sinusoidal tests at 1 and 10 MHz. There has been some discussion in the lightning community about extending these tests to 50 frequencies in the region 1-50 MHz. This paper presents characteristics of such tests on cable bundles and notes the relationship between bundle current and injected voltage; important parameters are the cable loss and Q of the driving waveform.

  10. 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.

  11. 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.

  12. 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.

  13. 75 MHz Ultrasound Biomicroscopy of Anterior Segment of Eye

    PubMed Central

    Silverman, Ronald H.; Cannata, Jonathan; Shung, K. Kirk; Gal, Omer; Patel, Monica; Lloyd, Harriet O.; Feleppa, Ernest J.; Coleman, D. Jackson

    2006-01-01

    Very high frequency ultrasound (35–50 MHz) has had a significant impact upon clinical imaging of the anterior segment of the eye, offering an axial resolution as small as 30 μm. Higher frequencies, while potentially offering even finer resolution, are more affected by absorption in ocular tissues and even in the fluid coupling medium. Our aim was to develop and apply improved transducer technology utilizing frequencies beyond those routinely used for ultrasound biomicroscopy of the eye. A 75-MHz lithium niobate transducer with 2 mm aperture and 6 mm focal length was fabricated. We scanned the ciliary body and cornea of a human eye six years post-LASIK. Spectral parameter images were produced from the midband fit to local calibrated power spectra. Images were compared with those produced using a 35 MHz lithium niobate transducer of similar fractional bandwidth and focal ratio. The 75-MHz transducer was found to have a fractional bandwidth (−6 dB) of 61%. Images of the post-LASIK cornea showed higher stromal backscatter at 75 MHz than at 35 MHz. The improved lateral resolution resulted in better visualization of discontinuities in Bowman’s layer, indicative of microfolds or breaks occurring at the time of surgery. The LASIK surface was evident as a discontinuity in stromal backscatter between the stromal component of the flap and the residual stroma. The iris and ciliary body were visualized despite attenuation by the overlying sclera. Very high frequency ultrasound imaging of the anterior segment of the eye has been restricted to the 35–50 MHz band for over a decade. We showed that higher frequencies can be used in vivo to image the cornea and anterior segment. This improvement in resolution and high sensitivity to backscatter from the corneal stroma will provide benefits in clinical diagnostic imaging of the anterior segment. PMID:17147058

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. SARSAT 121.5/243 MHz technical evaluation

    NASA Technical Reports Server (NTRS)

    Hayes, E. J.; Kissel, F. J.; Bossuat, F.

    1984-01-01

    The NOAA 8 SARSAT system performance was tested at 121.5/243 MHz to measure detection probability, detection threshold, location accuracy, ambiguity resolution, and multiple access capacity. Detection probability exceeds 0.95 for a single satellite pass. Detection threshold margin varies from 2 dB (243 MHz, incoherent) to 20 dB (121.5, coherent). Position location error is 20 km 68% of the time. Ambiguity is resolved 75% of the time. The system can locate 10 separate test signals.

  20. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part 22 Cellular Radiotelephone systems, and within the 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)...

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

    NASA Astrophysics Data System (ADS)

    Ivancic, William D.

    1988-07-01

    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.

  2. CEREBELLAR HISTOGENESIS IN RATS EXPOSED TO 2450 MHZ MICROWAVE RADIATION

    EPA Science Inventory

    Pregnant rats were either exposed or sham exposed from day 13 of gestation until birth to 2450 MHz linearly polarized microwaves at 10 mW/sq cm. A third matching group served as cage control. After birth, the pups were kept with their mothers for 21 days without any treatment, an...

  3. 47 CFR 95.628 - MedRadio transmitters in the 413-419 MHz, 426-432 MHz, 438-444 MHz, and 451-457 MHz bands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... band as part of a Medical Body Area Network (MBAN). (a) Operating frequencies. A MedRadio station...) Requirements for Medical Body Area Networks. A MedRadio programmer/control transmitter shall not commence... 451-457 MHz bands as part of a Medical Micropower Network (MMN). (a) Operating frequency. Only...

  4. 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.

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. High power testing of the 402.5 MHZ and 805 MHZ RF windows for the spallation neutron source accelerator

    SciTech Connect

    Cummings, K. A.; De Baca, J. M.; Harrison, J. S.; Rodriguez, M. B.; Torrez, P. A.; Warner, D. K.

    2003-01-01

    Hisorically, Radio Frequency (RF) windows have been a common point of failure in input power couplers; therefore, reliable RF windows are critical to the success of the Spallation Neutron Source (SNS) project. The normal conducting part of the SNS accelerator requires six RF windows at 402.5 MHz and eight RF windows at 805 MHz[l]. Each RF window will transmit up to 180 kW of average power and 2.5 MW peak power at 60 Hz with 1.2 millisecond pulses. The RF windows, designed and manufactured by Thales, were tested at the full average power for 4 hours to ensure no problems with the high average power and then tested to an effective forward power level of 10 MW by testing at 2.5 MW forward power into a short and varying the phase of the standing wave. The sliding short was moved from 0 to 180 degrees to ensure no arcing or breakdown problems occur in any part of the window. This paper discusses the results of the high power testing of both the 402.5 MHz and the 805 MHz RF windows. Problems encountered during testing and the solutions for these problems are discussed.

  11. 75 FR 35315 - Improving Public Safety Communications in the 800 MHz Band; New 800 MHz Band Plan for Puerto Rico...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-22

    ... public safety and other land mobile communication systems operating in the band, 69 FR 67823, November 22... Puerto Rico market compared to other markets, 72 FR 39756, July 20, 2007. Rather than specify a band plan... 800 MHz band reconfiguration in Puerto Rico as well as alternative band plans, 73 FR 40274, July...

  12. 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.

  13. R&D of BEPCII 500 MHz superconducting cavity

    NASA Astrophysics Data System (ADS)

    Liu, YaPing; Wang, GuangWei; Pan, WeiMin; Li, JiZhen; Liu, DeGui; Sun, Yi; Li, ZhongQuan; Dai, JianPing; Li, ShaoPeng; He, Kun; Wang, GuoPing; Zhao, GuangYuan; Ma, Qiang; Lin, HaiYing; Sha, Peng; Wang, QunYao; Qiu, Feng; Meng, FanBo; Li, Han

    2011-12-01

    Beijing Electron-Positron Collider Upgrade (BEPCII) adopts two 500 MHz superconducting cavities (SCCs) in each ring for higher accelerated gradient, higher Q and lower impedance (Wang et al. The proceedings of SRF'07). There's no spare cavity due to the limited time and funding during BEPCII construction. If any serious trouble happened on either one of the two cavities and could not be recovered in a short time, the operation of BEPCII facility will be affected. Therefore, since 2009 three spare cavities have been fabricated in China to ensure reliable operation, and two of them have been successfully vertically tested in January and July 2011. This paper will briefly present the manufacture, post-process and vertical test performance of the 500 MHz spare cavities.

  14. Possible radio emission from Uranus at 0.5 MHz

    NASA Technical Reports Server (NTRS)

    Brown, L. W.

    1975-01-01

    Radio emission from the direction of Uranus was detected in data from the radio astronomy experiment on the IMP-6 spacecraft. Previously, emission from the direction of Jupiter and Saturn was observed by the IMP-6 at a number of frequencies near 1 MHz during the period April 1971 to October 1972. These radio bursts were identified in the IMP-6 data through an analysis of the phase of the observed modulated signal detected from the spinning dipole antenna. This technique was applied to the direction of the planet Uranus with possible positive results. Over the approximately 500 days of data, three to six bursts with unique spectral characteristics were found. Identification with Uranus is confused by the likely presence of low level terrestrial and solar emission. The observed events persisted less than three minutes and are strongest in intensity near 0.5 MHz.

  15. Prototype 350 MHz niobium spoke-loaded cavities.

    SciTech Connect

    Delayen, J. R.; Kedzie, M.; Mammosser, J.; Piller, C.; Shepard, K. W.

    1999-05-10

    This paper reports the development of 350 MHz superconducting cavities of a spoke-loaded geometry, intended for the velocity range 0.2 < v/c < 0.6. Two prototype single-cell cavities have been designed, one optimized for velocity v/c = 0.4, and the other for v/c = 0.29. Construction of the prototype niobium cavities is nearly complete. Details of the design and construction are discussed, along with the results of cold tests.

  16. A Compact 500 MHz Femtosecond All-Fiber Ring Laser

    NASA Astrophysics Data System (ADS)

    Yang, Tong; Huang, Huichang; Yuan, Xiaozhi; Wei, Xiaoming; He, Xin; Mo, Shupei; Deng, Huaqiu; Yang, Zhongmin

    2013-05-01

    We demonstrate a fundamentally mode-locked all-fiber ring laser with the repetition rate up to 500 MHz and pulse duration of 250 fs at 1.5 µm. Only an optical integrated module, a 4.8 cm Er3+/Yb3+-codoped phosphate glass fiber, and a polarization controller are employed to construct the all-fiber ring cavity. Stable mode-locking laser is output by adjusting the polarization controller.

  17. 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.

  18. 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.

  19. Design for a 1 MHz soft magnetic material hysteresisgraph (abstract)

    NASA Astrophysics Data System (ADS)

    Dennison, Eric

    1993-05-01

    Until recently, high frequency (1 MHz) testing of magnetically soft materials has been typically limited to measurement of core loss and peak or inductive ac permeability. A high frequency hysteresisgraph allows direct examination of the hysteresis loop and calculation of values for magnetic parameters such as coercivity (Hc), peak permeability (μp), remanence (Br), core loss (Pc,Pcv,Pcm), bias drive field strength (Hbias), maximum H drive (Hmax) and maximum or saturation induction (Bmax). This paper describes the methods used to construct and calibrate a commercial high frequency magnetic hysteresisgraph which is capable of recording the primary current and secondary voltage waveforms of magnetic cores driven at up to 1 MHz. A system accuracy of 2% (for B and H parameter values) and 5% (for core loss) was achieved through careful control and calibration of signal phase shifts within the circuitry. System calibration, magnetic field calculations, and use of FFT post-processing of the acquired waveforms are discussed. The ability to accurately record the hysteresis loop of a material at 1 MHz allows high frequency core materials to be characterized not only by core loss and permeability, but by their hysteresis loop shape, coercivity, and remanence, both under pure ac and dc biased ac drive conditions. Changes in material characteristics due to dc biasing, temperature variations, defects, or mechanical stresses can be readily observed and described in terms of changes to the hysteresis curve shape.

  20. 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.

  1. Unknown radio emission at about 3 MHz recorded in Norway

    NASA Astrophysics Data System (ADS)

    Farges, T.; Blanc, E.; Strand, E.

    2012-04-01

    A wideband electric field antenna has been installed in Norway (at Hessdalen, 62°41' North and 11°12' East). A signal of 50 ms is automatically recorded every 5 s in order to monitor the spectral variations from 1 kHz to 5 MHz. Signals have been acquired during more than one year from September 2010 to December 2011. The measured electromagnetic spectrum is very similar to other spectra commonly measured in other places in the World. It shows emissions in numerous bands at fixed frequencies corresponding to radio transmissions in VLF, LF, MF and HF bands. However, one emission is quite different and arouses our curiosity. We find a quasi-continuous radio emission at a frequency varying from 2.7 to more than 3.4 MHz with a mean value of 3.0 MHz. The bandwidth is quite large (about 40 kHz) while it is about 9 kHz for all the other radio emissions at frequencies higher than 100 kHz. During the night, the frequency is relatively stable at about 3.1 MHz while during day-time a frequency shift of 200-300 kHz is often observed. These variations can be quick (few tens of minutes) or slow (several hours). Moreover, the emission disappears during day-time, the disappearance duration depending on the daylight duration. From November to the end of March, there is almost no disappearance while in April disappearances are more frequent and longer. From May to July, the emission disappears systematically during day-time from 6:00 UT to 20:00 UT. At the sunrise time the emission frequency suddenly decreases and systematically disappears when it reaches a threshold value (from 2.7 to 2.85 MHz). The emission (frequency and duration) is not influenced by the magnetic storms. We will show in the paper statistical results and some hypothesis on the mechanism which can produce this radio emission.

  2. 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

  3. 47 CFR 25.265 - Acceptance of interference in 2000-2020 MHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... (a) MSS receivers operating in the 2000-2020 MHz band must accept interference from lawful operations in the 1995-2000 MHz band, where such interference is due to: (1) The in-band power of any...

  4. 47 CFR 25.265 - Acceptance of interference in 2000-2020 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... (a) MSS receivers operating in the 2000-2020 MHz band must accept interference from lawful operations in the 1995-2000 MHz band, where such interference is due to: (1) The in-band power of any...

  5. 47 CFR 27.1031 - Reimbursement obligation of licensees at 1995-2000 MHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Reimbursement obligation of licensees at 1995-2000 MHz. 27.1031 Section 27.1031 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1915-1920 MHz and 1995-2000 MHz Reimbursement Obligation of Licensees at...

  6. 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... CARRIER SERVICES PUBLIC MOBILE SERVICES Paging and Radiotelephone Service 470-512 Mhz Trunked Mobile Operation § 22.651 470-512 MHz channels for trunked mobile operation. The following channels are...

  7. 47 CFR 22.651 - 470-512 MHz channels for trunked mobile operation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false 470-512 MHz channels for trunked mobile... CARRIER SERVICES PUBLIC MOBILE SERVICES Paging and Radiotelephone Service 470-512 Mhz Trunked Mobile Operation § 22.651 470-512 MHz channels for trunked mobile operation. The following channels are...

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a), and 1 CFR part 51. Copies of the...-406.1 MHz ELT must contain as an integral part a homing beacon operating only on 121.500 MHz that... (a) of this section. The 121.500 MHz homing beacon must have a continuous duty cycle that may...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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.

  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. Electrical conductivity of tissue at frequencies below 1 MHz

    NASA Astrophysics Data System (ADS)

    Gabriel, C.; Peyman, A.; Grant, E. H.

    2009-08-01

    A two-pronged approach, review and measurement, has been adopted to characterize the conductivity of tissues at frequencies below 1 MHz. The review covers data published in the last decade and earlier data not included in recent reviews. The measurements were carried out on pig tissue, in vivo, and pig body fluids in vitro. Conductivity data have been obtained for skeletal and myocardial muscle, liver, skull, fat, lung and body fluids (blood, bile, CSF and urine). A critical analysis of the data highlights their usefulness and limitations and enables suggestions to be made for measuring the electrical properties of tissues.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 24-MHz scanner for optoacoustic imaging of skin and burn.

    PubMed

    Vionnet, Laetitia; Gateau, Jerome; Schwarz, Mathias; Buehler, Andreas; Ermolayev, Volodymir; Ntziachristos, Vasilis

    2014-02-01

    Optoacoustic (photoacoustic) imaging uniquely visualizes optical contrast in high resolution and comes with very attractive characteristics for clinical imaging applications. In this paper, we showcase the performance of a scanner based on a 24 MHz center-frequency 128 element array, developed for applications in dermatology. We perform system characterization to examine the imaging performance achieved. We then showcase its imaging ability on healthy tissue and cancer. Finally, we image burns and human lesions in vivo and gain insights on the benefits and challenges of this approach as it is considered for diagnostic and treatment follow-up applications in dermatology and beyond. PMID:24216682

  2. 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.

  3. 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.

  4. Power sources for search and rescue 406 MHz beacons

    NASA Astrophysics Data System (ADS)

    Attia, Alan I.; Perrone, David E.

    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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. A 20-MHz ultrasound system for imaging the intestinal wall.

    PubMed

    Martin, R W; Silverstein, F E; Kimmey, M B

    1989-01-01

    An ultrasound system has been developed which uses high-frequency (20 MHz) ultrasound to provide high-resolution images of tissue. The system provides 0.21-mm range and 0.65-mm lateral resolution. The transducer aperture size is 1.8 mm maximum. Miniature probes have been developed which can image via the biopsy channels of standard fiberoptic endoscopes as well as probes for imaging in vitro. A commercially available video "frame grabber" is used in conjunction with a standard microcomputer for image acquisition. This allows images to be displayed and recorded on standard television equipment and be stored and manipulated digitally. The features of the system allow in vivo imaging, in vitro imaging after resection, and histological images of the same tissue region to be acquired and compared. This method is particularly useful in learning how to correctly interpret ultrasonic images of the intestinal wall. The use of 20 MHz is advantageous in achieving excellent resolution and small size probes. The system provides a unique approach to imaging the intestinal wall. PMID:2662554

  12. Possible radio emission from Uranus at 0.5 MHz

    NASA Technical Reports Server (NTRS)

    Brown, L. W.

    1976-01-01

    Radio emission from the direction of Uranus has been detected in data from the Goddard radio astronomy experiment on the IMP-6 spacecraft. Previously, emission from the direction of Jupiter and Saturn had been observed by IMP-6 at a number of frequencies near 1 MHz and were identified through an analysis of the phase of the observed modulated signal detected from the spinning dipole antenna. This technique was applied to the direction of Uranus with possible positive results. Over the approximately 500 days of data, three to six bursts with unique spectral characteristics have been found. The events persisted less than 3 minutes and are strongest in intensity near 0.5 MHz. Identification with Uranus is confused by the likely presence of low-level terrestrial and solar emission. Because of the unfavorable angular separation of earth and Uranus, there is a possibility that the bursts are atypical terrestrial magnetospheric phenomena, although the uniqueness of the set of events indicates the probable detection of radiation from Uranus.

  13. Cellular neoplastic transformation induced by 916 MHz microwave radiation.

    PubMed

    Yang, Lei; Hao, Dongmei; Wang, Minglian; Zeng, Yi; Wu, Shuicai; Zeng, Yanjun

    2012-08-01

    There has been growing concern about the possibility of adverse health effects resulting from exposure to microwave radiations, such as those emitted by mobile phones. The purpose of this study was to investigate the cellular neoplastic transformation effects of electromagnetic fields. 916 MHz continuous microwave was employed in our study to simulate the electromagnetic radiation of mobile phone. NIH/3T3 cells were adopted in our experiment due to their sensitivity to carcinogen or cancer promoter in environment. They were divided randomly into one control group and three microwave groups. The three microwave groups were exposed to 916 MHz EMF for 2 h per day with power density of 10, 50, and 90 w/m(2), respectively, in which 10 w/m(2) was close to intensity near the antenna of mobile phone. The morphology and proliferation of NIH/3T3 cells were examined and furthermore soft agar culture and animal carcinogenesis assay were carried out to determine the neoplastic promotion. Our experiments showed NIH/3T3 cells changed in morphology and proliferation after 5-8 weeks exposure and formed clone in soft agar culture after another 3-4 weeks depending on the exposure intensity. In the animal carcinogenesis study, lumps developed on the back of SCID mice after being inoculated into exposed NIH/3T3 cells for more than 4 weeks. The results indicate that microwave radiation can promote neoplastic transformation of NIH/3T3cells. PMID:22395787

  14. Experimental limits on gravitational waves in the MHz frequency range

    NASA Astrophysics Data System (ADS)

    Lanza, Robert Kingman, Jr.

    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 co-located 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 2.4x10 -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. SYNCHROTRON SPECTRAL CURVATURE FROM 22 MHz TO 23 GHz

    SciTech Connect

    Kogut, A.

    2012-07-10

    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.

  16. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... 22 of this chapter, Cellular Radiotelephone systems and within the 900 MHz Business/Industrial...

  17. 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...

  18. 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...

  19. 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...

  20. Comparison of 250 MHz R10K Origin 2000 and 400 MHz Origin 2000 Using NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Turney, Raymond D.; Thigpen, William W. (Technical Monitor)

    2001-01-01

    This report describes results of benchmark tests on Steger, a 250 MHz Origin 2000 system with R10K processors, currently installed at the NASA Ames National Advanced Supercomputing (NAS) facility. For comparison purposes, the tests were also run on Lomax, a 400 MHz Origin 2000 with R12K processors. The BT, LU, and SP application benchmarks in the NAS Parallel Benchmark Suite and the kernel benchmark FT were chosen to measure system performance. Having been written to measure performance on Computational Fluid Dynamics applications, these benchmarks are assumed appropriate to represent the NAS workload. Since the NAS runs both message passing (MPI) and shared-memory, compiler directive type codes, both MPI and OpenMP versions of the benchmarks were used. The MPI versions used were the latest official release of the NAS Parallel Benchmarks, version 2.3. The OpenMP versions used were PBN3b2, a beta version that is in the process of being released. NPB 2.3 and PBN3b2 are technically different benchmarks, and NPB results are not directly comparable to PBN results.

  1. Wideband impedance spectroscopy from 1 mHz to 10 MHz by combination of four- and two-electrode methods

    NASA Astrophysics Data System (ADS)

    Volkmann, J.; Klitzsch, N.

    2015-03-01

    Impedance Spectroscopy (IS) measurements allow to study a wide range of polarization mechanisms associated with different frequency ranges. Experimental devices usually cover limited frequency ranges with sufficient accuracy. We propose (a) a combination of four-electrode and two-electrode devices and (b) a data combination and mutual verification procedure using the actual sample under test. Hereby, we cover a frequency range from 1 mHz to 10 MHz. The data combination relies on the precondition that any dispersive disturbance decayed at some mutual point within an overlapping frequency range between 1 Hz and 45 kHz. We validate our data combination procedure by IS measurements on simple reference systems and comparison with widely accepted model functions, e.g. the complex refractive index model (CRIM) for high frequency behavior and Kramers-Kronig relations in terms of data consistency. In this respect, our suggested processing approach is superior to two selected alternative approaches. We successfully adapt typical empirical model functions, e.g. multi-Cole-Cole, to the resulting wideband data to show that they are fully applicable for further data analysis.

  2. Ultrahigh Frequency (100 MHz-300 MHz) Ultrasonic Transducers for Optical Resolution Medical Imagining.

    PubMed

    Fei, Chunlong; Chiu, Chi Tat; Chen, Xiaoyang; Chen, Zeyu; Ma, Jianguo; Zhu, Benpeng; Shung, K Kirk; Zhou, Qifa

    2016-01-01

    High resolution ultrasonic imaging requires high frequency wide band ultrasonic transducers, which produce short pulses and highly focused beam. However, currently the frequency of ultrasonic transducers is limited to below 100 MHz, mainly because of the challenge in precise control of fabrication parameters. This paper reports the design, fabrication, and characterization of sensitive broadband lithium niobate (LiNbO3) single element ultrasonic transducers in the range of 100-300 MHz, as well as their applications in high resolution imaging. All transducers were built for an f-number close to 1.0, which was achieved by press-focusing the piezoelectric layer into a spherical curvature. Characterization results demonstrated their high sensitivity and a -6 dB bandwidth greater than 40%. Resolutions better than 6.4 μm in the lateral direction and 6.2 μm in the axial direction were achieved by scanning a 4 μm tungsten wire target. Ultrasonic biomicroscopy images of zebrafish eyes were obtained with these transducers which demonstrate the feasibility of high resolution imaging with a performance comparable to optical resolution. PMID:27329379

  3. 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.

  4. Broadband pump-probe spectroscopy at 20-MHz modulation frequency.

    PubMed

    Preda, Fabrizio; Kumar, Vikas; Crisafi, Francesco; Figueroa Del Valle, Diana Gisell; Cerullo, Giulio; Polli, Dario

    2016-07-01

    We introduce an innovative high-sensitivity broadband pump-probe spectroscopy system, based on Fourier-transform detection, operating at 20-MHz modulation frequency. A common-mode interferometer employing birefringent wedges creates two phase-locked delayed replicas of the broadband probe pulse, interfering at a single photodetector. A single-channel lock-in amplifier demodulates the interferogram, whose Fourier transform provides the differential transmission spectrum. Our approach combines broad spectral coverage with high sensitivity, due to high-frequency modulation and detection. We demonstrate its performances by measuring two-dimensional differential transmission maps of a carbon nanotubes sample, simultaneously acquiring the signal over the entire 950-1350 nm range with 2.7·10-6  rms noise over 1.5 s integration time. PMID:27367078

  5. Pulsar polarisation below 200 MHz: Average profiles and propagation effects

    NASA Astrophysics Data System (ADS)

    Noutsos, A.; Sobey, C.; Kondratiev, V. I.; Weltevrede, P.; Verbiest, J. P. W.; Karastergiou, A.; Kramer, M.; Kuniyoshi, M.; Alexov, A.; Breton, R. P.; Bilous, A. V.; Cooper, S.; Falcke, H.; Grießmeier, J.-M.; Hassall, T. E.; Hessels, J. W. T.; Keane, E. F.; Osłowski, S.; Pilia, M.; Serylak, M.; Stappers, B. W.; ter Veen, S.; van Leeuwen, J.; Zagkouris, K.; Anderson, K.; Bähren, L.; Bell, M.; Broderick, J.; Carbone, D.; Cendes, Y.; Coenen, T.; Corbel, S.; Eislöffel, J.; Fender, R.; Garsden, H.; Jonker, P.; Law, C.; Markoff, S.; Masters, J.; Miller-Jones, J.; Molenaar, G.; Osten, R.; Pietka, M.; Rol, E.; Rowlinson, A.; Scheers, B.; Spreeuw, H.; Staley, T.; Stewart, A.; Swinbank, J.; Wijers, R.; Wijnands, R.; Wise, M.; Zarka, P.; van der Horst, A.

    2015-04-01

    Aims: We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial investigation of expected observational effects resulting from the propagation of polarised emission in the pulsar magnetosphere and the interstellar medium. Methods: The polarisation data presented in this paper have been calibrated for the geometric-projection and beam-shape effects that distort the polarised information as detected with the LOFAR antennas. We have used RM Synthesis to determine the amount of Faraday rotation in the data at the time of the observations. The ionospheric contribution to the measured Faraday rotation was estimated using a model of the ionosphere. To study the propagation effects, we have compared our low-frequency polarisation observations with archival data at 240, 400, 600, and 1400 MHz. Results: The predictions of magnetospheric birefringence in pulsars have been tested using spectra of the pulse width and fractional polarisation from multifrequency data. The derived spectra offer only partial support for the expected effects of birefringence on the polarisation properties, with only about half of our sample being consistent with the model's predictions. It is noted that for some pulsars these measurements are contaminated by the effects of interstellar scattering. For a number of pulsars in our sample, we have observed significant variations in the amount of Faraday rotation as a function of pulse phase, which is possibly an artefact of scattering. These variations are typically two orders of magnitude smaller than that observed at 1400 MHz by Noutsos et al. (2009), for a different sample of southern pulsars. In this paper we present a possible explanation for the difference in magnitude of this effect between the two frequencies, based on scattering. Finally, we have estimated the magnetospheric

  6. 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.

  7. 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.

  8. 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.

  9. Time delay spectrometry for hydrophone calibrations below 1 MHz.

    PubMed

    Gammell, P M; Harris, G R

    1999-11-01

    Knowing the response of miniature ultrasonic hydrophones at frequencies below 1 MHz is important for assessing the accuracy of acoustic pressure pulse measurements in medical ultrasound applications. Therefore, a time delay spectrometry (TDS) system was developed as an efficient means to measure hydrophone sensitivity in this frequency range. In TDS a swept-frequency signal is transmitted. A tracking receiver distinguishes arrivals with different propagation delays by their frequency offset relative to the signal being transmitted, thus eliminating spurious signals such as those reflected from the water surface or tank walls. Two piezoelectric ceramic source transducers were used: a standard planar disk and a disk with varying thickness to broaden the thickness-resonance. This latter design was preferred for its more uniform response without significant sensitivity loss. TDS is not an absolute method, but it was demonstrated to provide efficient, accurate calibrations via comparison with a reference hydrophone using a substitution technique. PMID:10573913

  10. 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.

  11. 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.

  12. Performance characteristics of a 425 MHz RFQ linac

    SciTech Connect

    Stovall, J.E.; Crandall, K.R.; Hamm, R.W.

    1980-01-01

    A radio-frequency quadrupole (RFQ) focused proton linac has been developed and successfully tested at the Los Alamos Scientific Laboratory (LASL) for the purpose of evaluating its performance and applicability as a low-beta accelerator. The geometry of the structure was designed to accept a 100-keV beam, focus, bunch, and accelerate it to 640 keV in 1.1 m with a high-capture efficiency and minimum emittance growth. The accelerator test facility includes an injector, low-energy transport section for transverse matching, and a high-energy transport section for analysis of the beam properties. The accelerator cavity is exited through a manifold powered by a 450-MHz klystron. Diagnostic instrumentation was prepared to facilitate operation of the accelerator and to analyze its performance. Measurements of the beam properties are presented and compared with the expected properties resulting from numerical calculations of the beam dynamics.

  13. Imaging Jupiter's radiation belts down to 127 MHz with LOFAR

    NASA Astrophysics Data System (ADS)

    Girard, J. N.; Zarka, P.; Tasse, C.; Hess, S.; de Pater, I.; Santos-Costa, D.; Nenon, Q.; Sicard, A.; Bourdarie, S.; Anderson, J.; Asgekar, A.; Bell, M. E.; van Bemmel, I.; Bentum, M. J.; Bernardi, G.; Best, P.; Bonafede, A.; Breitling, F.; Breton, R. P.; Broderick, J. W.; Brouw, W. N.; Brüggen, M.; Ciardi, B.; Corbel, S.; Corstanje, A.; de Gasperin, F.; de Geus, E.; Deller, A.; Duscha, S.; Eislöffel, J.; Falcke, H.; Frieswijk, W.; Garrett, M. A.; Grießmeier, J.; Gunst, A. W.; Hessels, J. W. T.; Hoeft, M.; Hörandel, J.; Iacobelli, M.; Juette, E.; Kondratiev, V. I.; Kuniyoshi, M.; Kuper, G.; van Leeuwen, J.; Loose, M.; Maat, P.; Mann, G.; Markoff, S.; McFadden, R.; McKay-Bukowski, D.; Moldon, J.; Munk, H.; Nelles, A.; Norden, M. J.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Röttgering, H.; Rowlinson, A.; Schwarz, D.; Smirnov, O.; Steinmetz, M.; Swinbank, J.; Tagger, M.; Thoudam, S.; Toribio, M. C.; Vermeulen, R.; Vocks, C.; van Weeren, R. J.; Wijers, R. A. M. J.; Wucknitz, O.

    2016-03-01

    Context. With the limited amount of in situ particle data available for the innermost region of Jupiter's magnetosphere, Earth-based observations of the giant planets synchrotron emission remain the sole method today of scrutinizing the distribution and dynamical behavior of the ultra energetic electrons magnetically trapped around the planet. Radio observations ultimately provide key information about the origin and control parameters of the harsh radiation environment. Aims: We perform the first resolved and low-frequency imaging of the synchrotron emission with LOFAR. At a frequency as low as 127 MHz, the radiation from electrons with energies of ~1-30 MeV are expected, for the first time, to be measured and mapped over a broad region of Jupiter's inner magnetosphere. Methods: Measurements consist of interferometric visibilities taken during a single 10-hour rotation of the Jovian system. These visibilities were processed in a custom pipeline developed for planetary observations, combining flagging, calibration, wide-field imaging, direction-dependent calibration, and specific visibility correction for planetary targets. We produced spectral image cubes of Jupiter's radiation belts at the various angular, temporal, and spectral resolutions from which flux densities were measured. Results: The first resolved images of Jupiter's radiation belts at 127-172 MHz are obtained with a noise level ~20-25 mJy/beam, along with total integrated flux densities. They are compared with previous observations at higher frequencies. A greater extent of the synchrotron emission source (≥4 RJ) is measured in the LOFAR range, which is the signature - as at higher frequencies - of the superposition of a "pancake" and an isotropic electron distribution. Asymmetry of east-west emission peaks is measured, as well as the longitudinal dependence of the radial distance of the belts, and the presence of a hot spot at λIII = 230° ± 25°. Spectral flux density measurements are on the low

  14. 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.

  15. 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.

  16. 47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... require or allow shall have the obligation to build out the Shared Wireless Broadband Network, as provided... (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz...

  17. 47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... require or allow shall have the obligation to build out the Shared Wireless Broadband Network, as provided... (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz...

  18. 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... geographic coverage and population served; (ii) An explanation of its record of expansion, including...

  19. DETECTION AND FLUX DENSITY MEASUREMENTS OF THE MILLISECOND PULSAR J2145–0750 BELOW 100 MHz

    SciTech Connect

    Dowell, J.; Taylor, G. B.; Craig, J.; Henning, P. A.; Schinzel, F.; Ray, P. S.; Blythe, J. N.; Clarke, T.; Helmboldt, J. F.; Ellingson, S. W.; Wolfe, C. N.; Lazio, T. J. W.; Stovall, K.

    2013-09-20

    We present flux density measurements and pulse profiles for the millisecond pulsar PSR J2145–0750 spanning 37 to 81 MHz using data obtained from the first station of the Long Wavelength Array. These measurements represent the lowest frequency detection of pulsed emission from a millisecond pulsar to date. We find that the pulse profile is similar to that observed at 102 MHz. We also find that the flux density spectrum between ≈40 MHz to 5 GHz is suggestive of a break and may be better fit by a model that includes spectral curvature with a rollover around 730 MHz rather than a single power law.

  20. 47 CFR 90.615 - Individual channels available in the General Category in 806-824/851-869 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Category in 806-824/851-869 MHz band. 90.615 Section 90.615 Telecommunication FEDERAL COMMUNICATIONS...-824 Mhz, 851-869 Mhz, 896-901 Mhz, and 935-940 Mhz Bands § 90.615 Individual channels available in the... 511-550 at locations farther then 110 km (68.4 miles) from the U.S./Mexico border and 140 km (87...

  1. 47 CFR 90.615 - Individual channels available in the General Category in 806-824/851-869 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Category in 806-824/851-869 MHz band. 90.615 Section 90.615 Telecommunication FEDERAL COMMUNICATIONS...-824 Mhz, 851-869 Mhz, 896-901 Mhz, and 935-940 Mhz Bands § 90.615 Individual channels available in the... 511-550 at locations farther then 110 km (68.4 miles) from the U.S./Mexico border and 140 km (87...

  2. 47 CFR 90.615 - Individual channels available in the General Category in 806-824/851-869 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Category in 806-824/851-869 MHz band. 90.615 Section 90.615 Telecommunication FEDERAL COMMUNICATIONS...-824 Mhz, 851-869 Mhz, 896-901 Mhz, and 935-940 Mhz Bands § 90.615 Individual channels available in the... 511-550 at locations farther then 110 km (68.4 miles) from the U.S./Mexico border and 140 km (87...

  3. 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

  4. 78 FR 8229 - Service Rules for Advanced Wireless Services in the 2000-2020 MHz and 2180-2200 MHz Bands, etc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ...In this document, the Federal Communications Commission (``Commission'') increases the Nation's supply of spectrum for mobile broadband by adopting flexible use rules for up to 40 megahertz of spectrum in the 2 GHz band (2000-2020 MHz and 2180-2200 MHz), which we term the AWS-4 band. In so doing, we carry out a recommendation in the National Broadband Plan that the Commission enable the......

  5. 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

  6. Perfectly matched pulsed 2MHz RF network and CW 30MHz RF matching network for the J-PARC RF-driven H- ion source

    NASA Astrophysics Data System (ADS)

    Ueno, A.; Namekawa, Y.; Yamazaki, S.; Ohkoshi, K.; Koizumi, I.; Ikegami, K.; Takagi, A.; Oguri, H.

    2013-02-01

    In order to satisfy the Japan Proton Accelerator Research Complex (J-PARC) 2nd stage requirements of an H- ion beam current of 60mA within normalized emittances of 1.5πmmṡmrad both horizontally and vertically, a flat top beam duty factor of 1.25% (500μs×25Hz) and a life-time of more than 50days, a cesiated RF-driven H- ion source using a internal-antenna developed at the Spallation Neutron Source (SNS) was developed. As similar as the SNS ion source, the 60kW pulsed 2MHz-RF and 200W CW 30MHz-RF systems are used in order to produce pulsed high-temperature 2MHz-RF plasma and CW low-temperature 30MHz-RF plasma. Each matching network for each system is composed of two vacuum variable condensers (VVCs). In order to supply pulsed 60kW-2MHz-RF power from the power supply (PS) on the ground level, a one-turn isolation transformer using FINEMET cores is installed between the PS and the J-PARC ion source. By comprehending the matching networks with the LTspice IV simulations and high- and low- power experiments and setting the parameters properly, the pulsed 2MHz-RF power up to 46 kW is successfully input to the hydrogen plasma without any misfire and with almost no reflected power.

  7. 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.

  8. 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.

  9. Graphene based plasmonic terahertz amplitude modulator operating above 100 MHz

    NASA Astrophysics Data System (ADS)

    Jessop, D. S.; Kindness, S. J.; Xiao, L.; Braeuninger-Weimer, P.; Lin, H.; Ren, Y.; Ren, C. X.; Hofmann, S.; Zeitler, J. A.; Beere, H. E.; Ritchie, D. A.; Degl'Innocenti, R.

    2016-04-01

    The terahertz (THz) region of the electromagnetic spectrum holds great potential in many fields of study, from spectroscopy to biomedical imaging, remote gas sensing, and high speed communication. To fully exploit this potential, fast optoelectronic devices such as amplitude and phase modulators must be developed. In this work, we present a room temperature external THz amplitude modulator based on plasmonic bow-tie antenna arrays with graphene. By applying a modulating bias to a back gate electrode, the conductivity of graphene is changed, which modifies the reflection characteristics of the incoming THz radiation. The broadband response of the device was characterized by using THz time-domain spectroscopy, and the modulation characteristics such as the modulation depth and cut-off frequency were investigated with a 2.0 THz single frequency emission quantum cascade laser. An optical modulation cut-off frequency of 105 ± 15 MHz is reported. The results agree well with a lumped element circuit model developed to describe the device.

  10. 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

  11. Effects of 900 MHz radiofrequency radiation on skin hydroxyproline contents.

    PubMed

    Çam, Semra Tepe; Seyhan, Nesrin; Kavaklı, Cengiz; Çelikbıçak, Ömür

    2014-09-01

    The present study aimed to investigate the possible effect of pulse-modulated radiofrequency radiation (RFR) on rat skin hydroxyproline content, since skin is the first target of external electromagnetic fields. Skin hydroxyproline content was measured using liquid chromatography mass spectrometer method. Two months old male wistar rats were exposed to a 900 MHz pulse-modulated RFR at an average whole body specific absorption rate (SAR) of 1.35 W/kg for 20 min/day for 3 weeks. The radiofrequency (RF) signals were pulse modulated by rectangular pulses with a repetition frequency of 217 Hz and a duty cycle of 1:8 (pulse width 0.576 ms). A skin biopsy was taken at the upper part of the abdominal costa after the exposure. The data indicated that whole body exposure to a pulse-modulated RF radiation that is similar to that emitted by the global system for mobile communications (GSM) mobile phones caused a statistically significant increase in the skin hydroxyproline level (p = 0.049, Mann-Whitney U test). Under our experimental conditions, at a SAR less than the International Commission on Non-Ionizing Radiation Protection safety limit recommendation, there was evidence that GSM signals could alter hydroxyproline concentration in the rat skin. PMID:24760629

  12. Merged and corrected 915 MHz Radar Wind Profiler moments

    DOE Data Explorer

    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.

  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. PMID:25574431

  14. 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. PMID:23000974

  15. 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

  16. 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.

  17. 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.

  18. Imaging on PAPER: Centaurus A at 148 MHz

    NASA Astrophysics Data System (ADS)

    Stefan, Irina I.; Carilli, Chris L.; Green, David A.; Ali, Zaki; Aguirre, James E.; Bradley, Richard F.; DeBoer, David; Dexter, Matthew; Gugliucci, Nicole E.; Harris, D. E.; Jacobs, Daniel C.; Klima, Pat; MacMahon, David; Manley, Jason; Moore, David F.; Parsons, Aaron R.; Pober, Jonathan C.; Walbrugh, William P.

    2013-06-01

    We present observations taken with the Precision Array for Probing the Epoch of Reionization (PAPER) of the Centaurus A field in the frequency range 114-188 MHz. The resulting image has a 25 arcmin resolution, a dynamic range of 3500 and an rms of 0.5 Jy beam-1 (for a beam size of 25 arcmin × 23 arcmin). A spectral index map of Cen A is produced across the full band. The spectral index distribution is qualitatively consistent with electron reacceleration in regions of excess turbulence in the radio lobes, as previously identified morphologically. Hence, there appears to be an association of `severe weather' in radio lobes with energy input into the relativistic electron population. We compare the PAPER large-scale radio image with the X-ray image from the ROSAT All Sky Survey. There is a tentative correlation between radio and X-ray features at the end of the southern lobe, some 200 kpc from the nucleus, as might be expected from inverse Compton (IC) scattering of the cosmic microwave background by the relativistic electrons also responsible for the radio synchrotron emission. The magnetic fields derived from the (possible) IC and radio emission are of similar magnitude to fields derived under the minimum pressure assumptions, ˜ 1 μG. However, the X-ray field is complex, with large-scale gradients and features possibly unrelated to Cen A. If these X-ray features are unrelated to Cen A, then these fields are lower limits.

  19. Maps of Jovian radio emission at 1412 MHz

    NASA Technical Reports Server (NTRS)

    Pater, I. D.

    1978-01-01

    Jupiter was observed with the Westerbork Radio Telescope at a frequency of 1412 MHz in December 1977 when it was at its most northerly opposition to the earth. Pictures were obtained of Jupiter in all four Stokes parameters at 24 different rotational aspects of the planet, each integrated over 15 degrees of Jovian rotation. The maps clearly indicate the presence of higher order terms in the dipolar field of Jupiter at distances of approximately 2 Rj from the center. They also show a displacement of the main dipole of 0.119 plus or minus 0.009 Rj from the center of the disk towards longitude 135-145 degree and a displacement of 0.04 plus or minus 0.04 Rj towards the north in agreement with the displacement found by the Pioneer spacecraft. From the data it is estimated that the thermal disk temperature at this frequency is more than 300 K but less than 340 K, which implies an ammonia mixing ratio of approximately 0.0005.

  20. Dynamic nuclear polarization at 700 MHz/460 GHz

    NASA Astrophysics Data System (ADS)

    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 1H/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.

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ... respect to one aspect of the Report and Order, 73 FR 67794, November 17, 2008, in this proceeding, to...&O. See Report and Order (800 MHz R&O), 69 FR 67823, November 22, 2004; Supplemental Report and Order on Reconsideration (800 MHz Supplemental R&O), 70 FR 6758, February 8, 2005. Shortly thereafter,...

  3. 47 CFR 90.1001 - 220 MHz service subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false 220 MHz service subject to competitive bidding. 90.1001 Section 90.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Service § 90.1001 220 MHz service subject to competitive bidding. Mutually exclusive initial...

  4. 47 CFR 90.1001 - 220 MHz service subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false 220 MHz service subject to competitive bidding. 90.1001 Section 90.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Service § 90.1001 220 MHz service subject to competitive bidding. Mutually exclusive initial...

  5. 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...

  6. 47 CFR 22.599 - Assignment of 72-76 MHz channels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... to the following conditions: (a) Assignments of 72-76 MHz channels for use within 129 kilometers (80... immediately discontinued. (b) 72-76 MHz channels may be assigned for use within 16 kilometers (10 miles) of a... to § 22.413. However, for use within 50 meters (164 feet) of a TV station transmitting on TV...

  7. 47 CFR 22.599 - Assignment of 72-76 MHz channels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to the following conditions: (a) Assignments of 72-76 MHz channels for use within 129 kilometers (80... immediately discontinued. (b) 72-76 MHz channels may be assigned for use within 16 kilometers (10 miles) of a... to § 22.413. However, for use within 50 meters (164 feet) of a TV station transmitting on TV...

  8. 47 CFR 22.599 - Assignment of 72-76 MHz channels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... to the following conditions: (a) Assignments of 72-76 MHz channels for use within 129 kilometers (80... immediately discontinued. (b) 72-76 MHz channels may be assigned for use within 16 kilometers (10 miles) of a... to § 22.413. However, for use within 50 meters (164 feet) of a TV station transmitting on TV...

  9. 47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Network. 90.18 Section 90.18 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... 700 MHz Nationwide Broadband Network. The 763-768/793-798 MHz band is dedicated to a broadband public..., pursuant to a Network Sharing Agreement and such other agreements as the Commission may require....

  10. 47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Network. 90.18 Section 90.18 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... 700 MHz Nationwide Broadband Network. The 763-768/793-798 MHz band is dedicated to a broadband public..., pursuant to a Network Sharing Agreement and such other agreements as the Commission may require....

  11. VizieR Online Data Catalog: M51 total intensity image at 333MHz (Mulcahy+, 2016)

    NASA Astrophysics Data System (ADS)

    Mulcahy, D. D.; Fletcher, A.; Beck, R.; Mitra, D.; Scaife, A. M. M.

    2016-06-01

    Total intensity image M51 with the 325MHz receiver of the GMRT at 15-arcsec resolution. Only the upperband data was used and thus the central frequency is 333MHz. Full details of the observation,calibration and imaging can be seen in the paper. (2 data files).

  12. 47 CFR 90.1408 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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...

  13. REWARMING MICE FROM HYPOTHERMIA BY EXPOSURE TO 2450-MHZ MICROWAVE RADIATION

    EPA Science Inventory

    Radiofrequency (RF) radiation between frequencies of 1 MHz and 100 GHz is, to varying degrees, readily transmitted and absorbed in biological tissues. Because of its internal absorption characteristics, RF radiation in the microwave spectrum (300-10,000 MHz) has been used in case...

  14. 47 CFR 90.1209 - Policies governing the use of the 4940-4990 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Policies governing the use of the 4940-4990 MHz band. 90.1209 Section 90.1209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing Licensing and Use of Frequencies in the 4940-4990 MHz Band...

  15. 47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Network. 90.18 Section 90.18 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... 700 MHz Nationwide Broadband Network. The 763-768/793-798 MHz band is dedicated to a broadband public..., pursuant to a Network Sharing Agreement and such other agreements as the Commission may require....

  16. 47 CFR 22.413 - Developmental authorization of 72-76 MHz fixed transmitters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Developmental Authorizations § 22.413 Developmental authorization... 5, 72-76 MHz channels are assigned for use within 16 kilometers (10 miles) of the antenna of any... substantial interruptions. (3) If a proposed 72-76 MHz fixed transmitter antenna is to be located within...

  17. 47 CFR 22.413 - Developmental authorization of 72-76 MHz fixed transmitters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Developmental Authorizations § 22.413 Developmental authorization... 5, 72-76 MHz channels are assigned for use within 16 kilometers (10 miles) of the antenna of any... substantial interruptions. (3) If a proposed 72-76 MHz fixed transmitter antenna is to be located within...

  18. 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.

  19. 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...

  20. 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...

  1. 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 80.148 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO... Watches § 80.148 Watch on 156.8 MHz (Channel 16). Each compulsory vessel, while underway, must maintain...

  2. 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 Section 80.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO... 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, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Watch on 156.800 MHz (Channel 16). 80.303 Section 80.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO... Watches § 80.303 Watch on 156.800 MHz (Channel 16). (a) During its hours of operation, each coast...

  4. 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 80.148 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO... Watches § 80.148 Watch on 156.8 MHz (Channel 16). Each compulsory vessel, while underway, must maintain...

  5. 47 CFR 90.804 - Aggregation of 900 MHz SMR licenses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Aggregation of 900 MHz SMR licenses. 90.804 Section 90.804 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO... Radio Service § 90.804 Aggregation of 900 MHz SMR licenses. The Commission will license each...

  6. 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...

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this standard can be inspected at the Federal... 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this standard can be inspected at the Federal... 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...

  9. 47 CFR 87.199 - Special requirements for 406.0-406.1 MHz ELTs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this standard can be inspected at the Federal... 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...

  10. 47 CFR 87.199 - Special requirements for 406.0-406.1 MHz ELTs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this standard can be inspected at the Federal... 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...

  11. 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....

  12. 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....

  13. 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....

  14. 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....

  15. 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....

  16. A High-Pressure, High-Resolution NMR Probe for Experiments at 500 MHz

    NASA Astrophysics Data System (ADS)

    Ballard, Lance; Yu, Aimee; Reiner, Carl; Jonas, Jiri

    1998-07-01

    A novel high-pressure, high-resolution NMR probe is described which operates at a frequency of 500 MHz. The design features an alternative RF coil (8 mm sample tube) for high frequency, sensitivity, probe power, and resolution (< 3.0 × 10-9). The probe is capable of pressures to at least 5 kbar over a temperature range of -30 to 80°C, and has a double-tuned1H/2H circuit which can tune at1H frequencies of either 300 or 500 MHz. The sensitivity of the 300-MHz circuit is over twice that of previous 10-mm high-pressure NMR probe designs, while at 500 MHz the sensitivity is nearly five times that of previous 300-MHz pressure probes. Potential biochemical applications are demonstrated by 2D NOESY spectra of a Troponin C mutant.

  17. Results of Q Disease Tests With 350-MHz Spoke Cavities

    NASA Astrophysics Data System (ADS)

    Tajima, Tsuyoshi; Edwards, Randy L.; Krawczyk, Frank L.; Liu, Jian-Fei; Schrage, Dale L.; Shapiro, Alan H.

    2003-07-01

    Spoke cavities have been developed at LANL for an accelerator-driven nuclear waste transmutation system. One of the most important issues for this development is how we can build and operate the accelerator at minimum costs. It would save a significant amount of money if we do not need to heat treat the cavity at high temperatures to avoid Q disease. This motivated us to check to see if Q disease occurs with 350-MHz spoke cavities. We have tested 3 cavities, ANL, LANL/EZ02 and LANL/EZ01 so far. The ANL cavity was made of RRR˜150 and the LANL cavities were made of RRR˜250 niobium. The ANL cavity was chemically polished 98 microns at LANL with a standard buffered chemical polishing (BCP) solution, i.e., HF:HNO3:H3PO4=1:1:2 by volume, at 14 - 18 °C. We did not see any Q degradation after holding the cavity at 100 - 102 K for 13 hours or at 100 - 142 K for 86 hours. This cavity was unintentionally baked at >200 °C under poor vacuum, which may have caused thicker oxide layer that prevent the Q disease from occurring as well as due to lower RRR. The LANL/EZ02 and LANL/EZ01 cavities were polished 150 microns with standard BCP solution at <15 °C. The LANL/EZ02 cavity showed a ˜50 % Q degradation after holding the cavity at 100 - 132 K for 61 hours. More systematic tests with LANL/EZ01 to determine the dangerous temperature range precisely are under way by changing the holding temperature every 10 K. The detail of the results will be presented here.

  18. The Search for Ionospheric Effects at 150 MHz with PAPER

    NASA Astrophysics Data System (ADS)

    Gugliucci, Nicole E.; Bradley, R.; PAPER Collaboration

    2012-01-01

    PAPER (the Precision Array to Probe the Epoch of Reionization) is a telescope designed to detect the redshifted hydrogen signal from the early universe. The hydrogen is at a redshift of approximately 6-14, bringing the spin-flip transition of neutral hydrogen from 1.4 GHz to a regime between 100 and 230 GHz. PAPER has a test site with 32 antennas in the Radio Quiet Zone of Green Bank, West Virginia, and a 64-antenna array at the Square Kilometer Array candidate site in the Karoo, South Africa. Astronomical observations at such low frequencies are made more challenging by the refractive properties of the ionosphere. We present the angular shifts in bright source positions (Cyg A, Cas A, Vir A, and Tau A) as probes of the variations in the total electron content (TEC) along the lines of sight between the sources and the 32-element array in Green Bank. With an integration time of 10 seconds, we can probe for the small fluctuations, using the visibilities, that may be the most difficult to calibrate in upcoming experiments and observations. More sensitive probes of longer timescales are also done by imaging the sky with both the 32 and 64-element arrays. Here again, the bright source position stability is used as an indicator of the TEC stability. The wideband nature of the PAPER instrument enables it to probe the effects of a varying TEC over a nearly 100 MHz bandwidth. We compare these measurements to more traditional methods of probing the ionosphere, such as GPS satellites, and we discuss the implications that these measurements will have on experiments aimed at detecting the epoch of reionization.

  19. 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

  20. Flexible A-scan rate MHz OCT: computational downscaling by coherent averaging

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Tom; Wieser, Wolfgang; Klein, Thomas; Petermann, Markus; Kolb, Jan-Phillip; Eibl, Matthias; Huber, Robert

    2016-03-01

    In order to realize fast OCT-systems with adjustable line rate, we investigate averaging of image data from an FDML based MHz-OCT-system. The line rate can be reduced in software and traded in for increased system sensitivity and image quality. We compare coherent and incoherent averaging to effectively scale down the system speed of a 3.2 MHz FDML OCT system to around 100 kHz in postprocessing. We demonstrate that coherent averaging is possible with MHz systems without special interferometer designs or digital phase stabilisation. We show OCT images of a human finger knuckle joint in vivo with very high quality and deep penetration.

  1. 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

    ... 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... Economic Area market (EA)-based 800 MHz Specialized Mobile Radio (SMR) licensees in the...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. Reactive Near-field to Far-field Transformation at 30 to 150MHz

    NASA Astrophysics Data System (ADS)

    Watanabe, Takuto; Hashimoto, Osamu; Takizawa, Koji; Kurihara, Hiroshi

    In this paper, radiation patterns of a small loop antenna (l<λ/10) were estimated by reactive near-field (E- and H- field) obtained by FIT (Finite Integral Technique) analysis at 30 to 150MHz applying the equivalent theorem. Then, accuracy of estimation was examined by variations of sampling intervals of reactive near-field on a virtual closed surface S (L×L×L) divided into Δx=Δy=Δz. As a result, an estimated result at the condition of Δx=Δy=Δz=L/30 was good agreement with the simulation (MW-studio/CST) within 0.3dB difference. Moreover differences of estimated results, between the minimum interval (L/30) and the maximum interval (L), were within 3.05dB at 30MHz, 3.44dB at 75MHz, and 3.56dB at 150MHz.

  7. 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.

  8. 76 FR 62309 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Chapter I Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: In this...

  9. 47 CFR 22.413 - Developmental authorization of 72-76 MHz fixed transmitters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Developmental Authorizations § 22.413 Developmental authorization... authorization for a 72-76 MHz fixed station and wish to request a regular authorization must file an...

  10. Specific absorption rate in models of man and monkey at 225 and 2000 MHz

    SciTech Connect

    Olsen, R.G.; Griner, T.A.

    1987-01-01

    Full-size models of a man and a rhesus monkey were exposed to radiofrequency (RF) radiation at 225 MHz. The model of man was also exposed to 2000 MHz. Specific absorption rates (SARs) were measured in partial-body sections, such as the arms, legs, etc., using gradient-layer calorimeters. Also, front-surface thermographic images were obtained to qualitatively show the heating patterns. For all of the configurations used, the SAR in the limbs was much higher than in the torso. Agreement (whole-body SARs) with spheroidal models was better for both models at 225 MHz than at 2000 MHz. These results indicate that in the frequency range two orders of magnitude above whole-body resonance, SAR in the limbs significantly contributes to the whole-body average SAR.

  11. 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... Block licensee shall have the exclusive right to build and operate the shared wireless broadband...

  12. 47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (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...

  13. 47 CFR 27.1300 - 600 MHz band subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... competitive bidding. As required by section 6403(c) of the Spectrum Act, applications for 600 MHz band initial licenses are subject to competitive bidding. The general competitive bidding procedures set forth in 47...

  14. 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.

  15. 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...

  16. 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...

  17. 78 FR 45524 - Auction of H Block Licenses in the 1915-1920 MHz and 1995-2000 MHz Bands; Comment Sought on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    .... SUMMARY: This document announces the intention to hold an auction of H Block licenses in the 1915-1920 and...) announces its intention to hold an auction of licenses in the 1915-1920 MHz (Lower H Block) and 1995-2000... with the bidders' need to study round results and adjust their bidding strategies. Under this...

  18. 47 CFR 101.82 - Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  19. 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 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...

  20. 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 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...

  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, 2012 CFR

    2012-10-01

    ... Frequencies in the 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Processing of... minimum required median desired signal, as measured at the R.F. input of the receiver, will be as follows... minimum median desired signal levels specified in § 22.970(a)(1)(i) of this chapter and §...

  2. 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, 2014 CFR

    2014-10-01

    ... Frequencies in the 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Processing of... minimum required median desired signal, as measured at the R.F. input of the receiver, will be as follows... minimum median desired signal levels specified in § 22.970(a)(1)(i) of this chapter and §...

  3. 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, 2013 CFR

    2013-10-01

    ... Frequencies in the 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Processing of... minimum required median desired signal, as measured at the R.F. input of the receiver, will be as follows... minimum median desired signal levels specified in § 22.970(a)(1)(i) of this chapter and §...

  4. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... Procedures and Process-Unacceptable Interference § 90.672 Unacceptable interference to non-cellular 800...

  5. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... Procedures and Process-Unacceptable Interference § 90.672 Unacceptable interference to non-cellular 800...

  6. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... Procedures and Process-Unacceptable Interference § 90.672 Unacceptable interference to non-cellular 800...

  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. Detection of Pulsed Emission from the Millisecond Pulsar PSR J2145-0750 Below 100 MHz

    NASA Astrophysics Data System (ADS)

    Taylor, Gregory B.; Dowell, J.; Wavelength Array, Long

    2014-01-01

    Millisecond pulsars (MPSs) are distinguished from normal pulsars by faster rotation periods, weaker magnetic fields, and flux density spectra that are well fit by a single power law down to 100 MHz. Below 100 MHz some MSPs show a break in the power law, however, additional observations, particularly of the pulse profile, are needed in this frequency range to provide better constraints on emission mechanisms. The first station of the Long Wavelength Array, LWA1, is a low frequency telescope that is ideally suited to address these questions. We present recent results from LWA1 on the millisecond pulsar PSR J2145-0750. Using coherent dedispersion we detected pulsed emission between 37 and 85 MHz. From this we derive flux densities and pulse profiles at 41, 57, 65, 73, and 81 MHz. We find that the flux density spectrum of PSR J2145-0750 appears to flatten below 100 MHz relative to the spectral index of ~-1.6 found in the literature. We also find that the pulse profile shows little evolution over this frequency range and is similar to profiles found at 102 MHz. We also discuss the prospects for precision dispersion measure monitoring at these frequencies. Construction of the LWA has been supported by the Office of Naval Research under Contract N00014-07-C-0147. Support for operations and continuing development of the LWA1 is provided by the National Science Foundation under grants AST-1139963 and AST-1139974 of the University Radio Observatory program.

  10. 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

  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. Search for 54-MHz Maser Emission from Interstellar Hydroxyl Using the Long Wavelength Array

    NASA Astrophysics Data System (ADS)

    Hoffman, Ian M.

    2015-01-01

    We present the results of an observational campaign using the Long Wavelength Array (LWA). The level splitting of the rotational ground state of the hydroxyl (OH) molecule gives rise to the four familiar 1.7-GHz (18-cm) 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 radiative process, it is expected that only maser emission will generate a detectable 54-MHz signal. Many of the prevailing pumping models for 18-cm masers are also suggestive of population inversions of the 54-MHz transitions. We have targeted our search toward Galactic locations that are known to exhibit strong 1720-MHz maser emission from OH with the expectation that either of the 54-MHz transitions will also be overpopulated.Using the LWA station LWA1, we have searched the sources NGC 7538, G33.64-0.21, W75N, and Sgr A. For each target we employed 20 hours of integration time in beam-formed mode. We employed 1024 spectral channels in a 250-kHz observing band for each of the two transitions, resulting in a velocity resolution of approximately 1.4 km/s. We did not detect masers in either transition toward any of the sources. Previously reported observations of W75N using LOFAR also resulted in a non-detection; none of the other sources have been searched previously for either 53.2- or 55.1-MHz emission. We discuss the results in the context of previous and ongoing searches for 54-MHz emission.This work is supported by Wittenberg University through the Physics Department. Construction of the LWA has been supported by the Office of Naval Research under Contract N00014-07-C-0147. Support for operations and continuing development of the LWA1 is provided by the National Science Foundation under grants AST-1139963 and AST-1139974 of the University Radio Observatory

  13. Genotoxicity evaluation of electromagnetic fields generated by 835-MHz mobile phone frequency band.

    PubMed

    Chang, S-K; Choi, J-S; Gil, H-W; Yang, J-O; Lee, E-Y; Jeon, Y-S; Lee, Z-W; Lee, M; Hong, M-Y; Ho Son, T-; Hong, S-Y

    2005-04-01

    It is still unclear whether the exposure to electromagnetic fields (EMFs) generated by mobile phone radiation is directly linked to cancer. We examined the biological effects of an EMF at 835 MHz, the most widely used communication frequency band in Korean CDMA mobile phone networks, on bacterial reverse mutation (Ames assay) and DNA stability (in vitro DNA degradation). In the Ames assay, tester strains alone or combined with positive mutagen were applied in an artificial mobile phone frequency EMF generator with continuous waveform at a specific absorption rate (SAR) of 4 W/kg for 48 h. In the presence of the 835-MHz EMF radiation, incubation with positive mutagen 4-nitroquinoline-1-oxide and cumene hydroxide further increased the mutation rate in Escherichia coli WP2 and TA102, respectively, while the contrary results in Salmonella typhimurium TA98 and TA1535 treated with 4-nitroquinoline-1-oxide and sodium azide, respectively, were shown as antimutagenic. However, these mutagenic or co-mutagenic effects of 835-MHz radiation were not significantly repeated in other relevant strains with same mutation type. In the DNA degradation test, the exposure to 835-MHz EMF did not change the rate of degradation observed using plasmid pBluescript SK(+) as an indicator. Thus, we suggest that 835-MHz EMF under the conditions of our study neither affected the reverse mutation frequency nor accelerated DNA degradation in vitro. PMID:15785322

  14. 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

  15. 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. PMID:16673832

  16. 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

    ... Frequencies in the 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Processing of... minimum required median desired signal, as measured at the R.F. input of the receiver, will be as follows... signal levels specified in § 22.970(a)(1)(i) of this chapter and § 90.672(a)(1)(i) shall apply; (ii)...

  17. 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. PMID:20681803

  18. Temperate zone sporadic-E maps /f/0/E/s/ greater than 7 MHz/

    NASA Technical Reports Server (NTRS)

    Smith, E. K.

    1978-01-01

    Three maps are presented of f(0) sporadic-E greater than 7 MHz for temperate zones. During map preparation it was assumed that: (1) the geographical area would be between plus and minus 60 deg geomagnetic latitude, excluding the equatorial zone, (2) the maps would be for f(0) sporadic-E greater than 7 MHz, (3) sunspot cycle variation would be ignored, (4) one map would represent the peak sporadic-E period with a discontinuity at the geographic equator, (5) one map would represent non-peak periods with a discontinuity at the geographic equator, (6) one map would represent all twelve months with no equatorial discontinuity, and (7) previously determined coefficients for median and upper decile f(0) sporadic-E would be extrapolated to 7 MHz.

  19. 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.

  20. Developmental and teratogenic effects of 2450-MHz microwaves in mice. Final report

    SciTech Connect

    Szmigielski, S.; Chazan, B.

    1986-01-01

    The report describes results of experimental investigations performed during 1982-1985 which indicate that exposure of pregnant mice to nonthermal 2450-MHz microwave fields during the whole period of gestation did not influence the course and outcome of pregnancy. However, both loss of early pregnancy and development of malformations are possible after exposure to thermal fields. An original finding from the investigations is enhancement of teratogenic potency of cytosine arabinoside (ara-C) in pregnant mice exposed to non-thermal 2450-MHz microwave fields. In another investigation, female and male mice (parents) were exposed to non-thermal 2450-MHz microwave fields for 3-5 months (2 hr daily) prior to fertilization. It was found that exposure of parents to microwaves may influence both the course and outcome of pregnancy.

  1. 30 MHz backscatter and Doppler signals from individual microbubbles undergoing inertial cavitation

    NASA Astrophysics Data System (ADS)

    Yoon, Johanna M.; Everbach, E. Carr

    2002-05-01

    Short pulses (1-2 microseconds duration) of 30 MHz ultrasound were used to interrogate individual OptisonTM and PESDA microbubbles convected in a coaxial jet flow or adhering to a thin MylarTM window. Backscattered signals were recorded as the bubbles were forced into symmetrical or asymmetrical collapse by application of 1 MHz ultrasound pulses from a focused source in water. Peak-to-peak amplitudes of the backscattered signal were converted to radius-time curves via comparison with similar signals from a monodisperse population of polystyrene spheres of known diameter. Additionally, backscattered signals were mixed with reference sinusoids at 30 MHz and low-pass filtered to yield Doppler signals. Results are consistent with theoretical models and provide a possible method to quantify asymmetrical bubble collapse via Doppler signature.

  2. Characterization of a 10-MHz quadrant APD for measuring frequency oscillations and tip displacements of microcantilevers

    NASA Astrophysics Data System (ADS)

    Burke, Brian G.; LaVan, David A.

    2012-10-01

    The room-temperature response of a 10-MHz quadrant avalanche photodiode (APD) is investigated for detection of high frequency oscillations and tip displacements of fabricated microcantilevers. Currently, no quadrant detectors with a response bandwidth in the megahertz range are available, and oscillations on the order of a few microseconds cannot be resolved. A comparison is made between optical and opto-mechanical measurements to characterize this detector by investigating the frequency response and signal-to-noise (SNR) of pulsed laser signals up to 10 MHz and reflected laser signals from freely vibrating microcantilevers up to 1.64 MHz. The power level of the minimum detectable signal incident on the APD is found to be 28.2 ± 5.0 nW for optical measurements and 1.0 μW ± 5.0 nW for opto-mechanical measurements.

  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. PMID:9399707

  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. Preparation of the UNDERC 200 MHz /sup 1/H NMR spectral catalog, Volume II

    SciTech Connect

    Gaides, G.E.; Farnum, S.A.; Wolfson, A.C.; Farnum, B.W.

    1984-01-01

    High resolution 200 MHz /sup 1/H NMR is used extensively to identify the components of complex low-rank coal-derived materials. We have compiled a catalog of 302 spectra of standards: (1) and are compiling a second, similar volume of 125 additional spectra. Many of these new compounds have only recently become available from commercial suppliers, or by synthesis. Like the previous catalog, Volume II is divided into two sections: a tabular section of all the compounds with their correct names, structure, and a line list of the chemical shifts, and a section which contains the actual spectra. Each section is arranged by functional group, for example, alkanes, phenols, etc. in order of their chromatographic elution. There is also an appendix which lists the suppliers of all the compounds in the catalog. Volume II contains several features not incorporated in the original catalog. We have added an alphabetical listing of all the compounds in both NMR catalogs, as well as formula and molecular weight indices. An added feature of this volume is the expanded coverage of nitrogen-containing compounds. Though there are many /sup 1/H NMR spectral catalogs in print, there are none that contain spectra run on 200 MHz spectrometers. Many spectra that appear complex at 60 MHz become first order at 200 MHz, facilitating their interpretation. At the UNDERC the majority of our samples are extremely complex mixtures. The simplification of the spectra of the individual components is necessary to characterize these coal-derived liquids. Another advantage of /sup 1/H NMR spectra run at 200 MHz is the greater than eleven-fold increase in sensitivity over those run at 60 MHz (2). Smaller, or more dilute samples may therefore be utilized. 2 references, 1 figure.

  7. Detachable 400-MHz acousto-optic phase modulator for a single-mode optical fiber.

    PubMed

    Patterson, D B; Godil, A A; Kino, G S; Khuri-Yakub, B T

    1989-02-15

    A single-mode-fiber phase modulator was constructed by contacting the fiber with a lapped glass capillary tube. The capillary's inner surface provides a long, effectively semicircular contact region to the fiber, allowing throughput of acoustic waves launched from a thin-film ZnO transducer fabricated directly onto the capillary's other lapped face. The device operated at a center frequency of 416 MHz with a FWHM bandwidth of 14 MHz. The maximum phase shift was 0.033 rad/ radicalmw, with a largest measured value of 1.2 rad at 1.3-W input electrical power. PMID:19749885

  8. A Betatron tune fitting package for the Tevatron 21.4 MHz Schottky

    SciTech Connect

    Lebrun, Paul L.G.; Sen, Tanaji; You, Jian-Ming; Yuan, Zong-Wei; Todesco, Ezio; /CERN

    2005-05-01

    The Fermilab Tevatron is equipped with two independent Schottky monitors for measurement of betatron tunes, one operating at 21.4 MHz and the other at 1.7 GHz. A new front-end and related data acquisition for the 21.4 MHz resonator has been installed and commissioned during the FY04 Collider RunII. Sophisticated fitting strategies are required to analyze the spectra. Optimization of this fitting package allows us to report tune and chromaticity measurements at almost 1 Hz.

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

    NASA Astrophysics Data System (ADS)

    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 1H,14N- and 2H,15N-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.

  10. 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.

  11. 77 FR 33972 - Channel Spacing and Bandwidth Limitations for Certain Economic Area (EA)-based 800 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ...In this document the Commission amends its rules to allow Economic Area (EA)-based 800 MHz Specialized Mobile Radio (SMR) licensees to exceed a legacy channel spacing and bandwidth limitation, subject to conditions to protect 800 MHz public safety licensees from harmful interference. Licensees are permitted to exceed the channel spacing and bandwidth limitation in the 813.5-824/858.5-869 MHz......

  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

    ... (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private... Security Bureau and the Wireless Telecommunications Bureau are delegated joint responsibility...

  13. 77 FR 43008 - Unlicensed Personal Communications Service Devices in the 1920-1930 MHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-23

    ...This document modifies the rules governing the operation of Unlicensed Personal Communications Service (UPCS) devices in the 1920- 1930 MHz band (UPCS band) to promote more efficient use of the UPCS band and to facilitate the introduction of a new generation of unlicensed devices capable of supporting broadband connectivity using Digital Enhanced Cordless Telecommunications (DECT)...

  14. DIFFERENTIAL EFFECTS OF 200, 591, AND 2,450 MHZ RADIATION ON RAT BRAIN ENERGY METABOLISM

    EPA Science Inventory

    Three key compounds in brain metabolism have been measured during and after exposure to continuous wave radiofrequency radiation at 200, 591, and 2,450 MHz. Frequency-dependent changes have been found for all three compounds. Changes in NADH fluorescence have been measured on the...

  15. 47 CFR 95.627 - MedRadio transmitters in the 401-406 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Radio programmer/control transmitters operating in the 401-406 MHz band must operate under the control... used by the programmer/control transmitter for a communications session. Before the monitoring system of a MedRadio programmer/control transmitter initiates a MedRadio communications session,...

  16. EXPOSURE OF RATS TO 425-MHZ (CW) RADIOFREQUENCY RADIATION: EFFECTS ON LYMPHOCYTES

    EPA Science Inventory

    Four experiments were performed in which six pregnant rats were exposed from day 12 of pregnancy to parturition, for 4 hours a day in a temperature-controlled environment, to 425-MHz (CW) radiation, using a multimode rectangular strip transmission line. Four male pups born to eac...

  17. SYSTEMS FOR EXPOSING MICE TO 2,450-MHZ ELECTROMAGNETIC FIELDS

    EPA Science Inventory

    Two systems for exposing mice to 2,450-MHz electromagnetic fields are described. In a waveguide system, four mice were placed in a Styrofoam cage and exposed dorsally to circularly polarized electromagnetic fields. The temperature and humidity in the mouse holder were kept consta...

  18. 47 CFR 27.1230 - Conversion of the 2500-2690 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Conversion of the 2500-2690 MHz band. 27.1230 Section 27.1230 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband...

  19. 47 CFR 27.1303 - Upper 700 MHz D Block license conditions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Block licensee shall have the exclusive right to build and operate the shared wireless broadband network... 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...

  20. 47 CFR 27.1230 - Conversion of the 2500-2690 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Conversion of the 2500-2690 MHz band. 27.1230 Section 27.1230 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband...

  1. 47 CFR 27.1230 - Conversion of the 2500-2690 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Conversion of the 2500-2690 MHz band. 27.1230 Section 27.1230 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband...

  2. 47 CFR 27.1230 - Conversion of the 2500-2690 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Conversion of the 2500-2690 MHz band. 27.1230 Section 27.1230 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband...

  3. 47 CFR 27.1230 - Conversion of the 2500-2690 MHz band.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Conversion of the 2500-2690 MHz band. 27.1230 Section 27.1230 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband...

  4. 47 CFR 27.1303 - Upper 700 MHz D Block license conditions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Block licensee shall have the exclusive right to build and operate the shared wireless broadband network... 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...

  5. CHRONIC EXPOSURE OF RATS TO 100-MHZ (CW) RADIOFREQUENCY RADIATION: ASSESSMENT OF BIOLOGICAL EFFECTS

    EPA Science Inventory

    A multidisciplinary approach was employed to assess the possible biological effects of chronic exposure of rats to 100-MHz continuous wave (CW) radiofrequency (RF) radiation. A group of 20 time-bred rats were exposed in a transverse electronmagnetic mode (TEM) transmission line t...

  6. EFFECTS OF 200, 591 AND 2450 MHZ MICROWAVES ON CEREBRAL ENERGY METABOLISM

    EPA Science Inventory

    Earlier work has shown that levels of key biochemicals in the energy production system of rat brain are affected by exposure to 591 MHz microwave radiation at 13.8 mW/sq cm. The objectives of this study were to determine whether there are direct microwave effects on the biologica...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 47 CFR 15.243 - Operation in the band 890-940 MHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  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 15.225 - 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. Summary on the Fundamental Mode Damper Experiments of the 56 MHz SRF Cavity

    SciTech Connect

    Choi,E.; Hahn, H.

    2008-07-01

    This report summarizes the experimental results done with the fundamental damper for the 56 MHz prototype Cu cavity. Various measurements were done on the cavity including determination of the position of the fundamental damper and measurement of the frequency and Q factor changes while the damper is withdrawn. Prediction on the dissipated power while the damper is withdrawn was made by experiments.

  15. 76 FR 51271 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-18

    ... COMMISSION 47 CFR Part 90 Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the... interoperable public safety broadband network. The establishment of a common air interface for 700 MHz public safety broadband networks will create a foundation for interoperability and provide a clear path for...

  16. Pilot observations at 74 MHz for global 21cm cosmology with the Parkes 64 m

    NASA Astrophysics Data System (ADS)

    Bannister, Keith; McConnell, David; Reynolds, John; Chippendale, Aaron; Landecker, Tom L.; Dunning, Alex

    2013-10-01

    We propose a single pilot observing session using the existing 74 MHz feed at Parkes to evaluate tools and techniques to optimise low frequency (44-88 MHz) observing. 1. A continuum map of the diffuse emission in the Southern sky at 74 MHz. Such a map would be of great help to single-dipole 21cm cosmology experiments, whose diffuse Galactic foregrounds are currently poorly constrained (Pritchard & Loeb, 2010b; de Oliveira-Costa et al., 2008). 2. A wideband (44-88 MHz) map of of the Southern sky, which can be used as a direct detection of the dark ages global signal. Recent theoretical work has shown that the Parkes aperture of 64 m is the optimal size for such a direct detection, which could be achieved at 25? in as little as 100 hrs of observing (Liu et al., 2012). After receiving a 4.1 grade in the previous round, our observations were not scheduled due to limited receiver changes. We are therefore re-proposing as formality. Since the proposal, we have obtained RFI measurements with the feed pointed at zenith. We are confident the dominant source of RFI can be found and removed. If observing at this band is possible, at least two scientific outputs relevant to global 21cm cosmology (among many others) are put within reach:

  17. GROWTH AND DEVELOPMENT OF MICE OFFSPRING AFTER IRRADIATION IN UTERO WITH 2,450-MHZ MICROWAVES

    EPA Science Inventory

    Mice offspring irradiated in utero with 2,450-MHz radio-frequency (RF) radiation at 0 or 28 mW/cm. sq. (whole-body averaged specific absorption rate = 0 or 16.5 W/kg) for 100 minutes daily on days 6 through 17 of gestation were evaluated for maturation and development on days 1, ...

  18. MEASUREMENT OF BLOOD-BRAIN BARRIER PERMEATION IN RATS DURING EXPOSURE TO 2450-MHZ MICROWAVES

    EPA Science Inventory

    Adult rats anesthesized with pentobarbital and injected intravenously with a mixture of (C) sucrose and (H) inulin were exposed for 30 min. to an environment at an ambient temperature of 22, 30, or 40 C, or were exposed at 22 C to 2450-MHz CW microwave radiation at power densitie...

  19. ASSESSMENT OF IMMUNE FUNCTION DEVELOPMENT IN MICE IRRADIATED IN UTERO WITH 2450-MHZ MICROWAVES

    EPA Science Inventory

    Groups of time-bred pregnant mice were irradiated with 2450-MHz microwaves at an incident power density of 28 mW/sq. cm. for 100 min daily from day 6 to day 18 of pregnancy. The average specific absorption rate (SAR) was 16.5 W/kg. Two experiments were performed under these condi...

  20. Dielectric Properties of Uncooked Chicken Breast Muscles from 10 to 1800 MHz

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dielectric properties, consisting of the dielectric constant and loss factor, were measured (by using an open-ended coaxial-line probe) for uncooked chicken breast muscle Pectoralis major and Pectoralis minor, deboned at 2 and 24 h postmortem, over the frequency range from 10 to 1800 MHz at tem...

  1. BIOLOGICAL EFFECTS OF LONG-TERM EXPOSURE OF RATS TO 970-MHZ RADIOFREQUENCY RADIATION

    EPA Science Inventory

    Rats (N=16) exposed individually in circularly polarized waveguides to 970-MHz electromagnetic radiation (SAR=2.5 mW/g, 22 h daily for 70 consecutive days) had significantly higher serum levels of triglycerides, albumin, and total protein compared with sham-irradiated controls. N...

  2. Dielectric properties of sweetpotato purees at 915 MHz as affected by temperature and chemical composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A process for rapid sterilization and aseptic packaging of sweetpotato puree using a continuous flow microwave system operating at 915 MHz has been successfully developed. This development offers an opportunity for converting sweetpotato roots into a functional ingredient for the food industry....

  3. 47 CFR 90.279 - Power limitations applicable to the 421-430 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Power limitations applicable to the 421-430 MHz band. 90.279 Section 90.279 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Standards for Special Frequencies or Frequency Bands § 90.279 Power...

  4. 47 CFR 90.279 - Power limitations applicable to the 421-430 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Power limitations applicable to the 421-430 MHz band. 90.279 Section 90.279 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Standards for Special Frequencies or Frequency Bands § 90.279 Power...

  5. BEHAVIOR, PHYSIOLOGY, AND ENERGY DEPOSITION IN RATS CHRONICALLY EXPOSED TO 2450 MHZ RADIATION

    EPA Science Inventory

    The research program was initiated to determine both the specific absorption rate (SAR) and the behavioral and physiological consequences of chronic CW microwave radiation exposure at 2450 MHz in the laboratory rat. Whole-body average and local SARs at discrete sites within the b...

  6. FETAL AND MATERNAL EFFECTS OF CONTINUAL EXPOSURE OF RATS TO 970-MHZ CIRCULARLY-POLARIZED MICROWAVES

    EPA Science Inventory

    Virtually continual exposure to 970-MHz microwaves in circularly-polarized waveguides was used to elicit fetal responses in Sprague-Dawley rats during gestation. wo hundred fifty rats were exposed to microwave radiation at whole-body averaged specific absorption rates (SAR) of 0....

  7. EFFECT OF 2450 MHZ MICROWAVE EXPOSURE ON BEHAVIOURAL THERMOREGULATION IN MICE

    EPA Science Inventory

    The purpose of this study was to determine the threshold specific absorption rate (SAR) during exposure to 2450 MHz continuous wave (CW) microwaves that affected thermoregulatory behavior in mice. A plexiglas shuttle box was placed inside a waveguide imposed with a temperature gr...

  8. 75 FR 33220 - Unlicensed Personal Communications Services Devices in the 1920-1930 MHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... Rulemaking Proceedings, 63 FR 24121 (1998). Electronic Filers: Comments may be filed electronically using the... COMMISSION 47 CFR Part 15 Unlicensed Personal Communications Services Devices in the 1920- 1930 MHz Band... Commission proposes changes to its rules to enable Unlicensed Personal Communications Service (UPCS)...

  9. 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.

  10. 47 CFR 90.357 - Frequencies for LMS systems in the 902-928 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 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...

  11. 47 CFR 90.357 - Frequencies for LMS systems in the 902-928 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 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...

  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. OBSERVATIONS OF SYRIAN HAMSTER FETUSES AFTER EXPOSURE TO 2450-MHZ MICROWAVES

    EPA Science Inventory

    The teratogenic potential of microwaves was examined in a rodent species, the Syrian hamster. Exposure of hamsters to 2450-MHz CW microwaves at a power denisty of 20 mW/sq. cm. for 100 minutes daily on days 6-14 of gestation caused no significant change in fetal survival, body we...

  14. 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.

  15. 78 FR 70499 - Private Land Mobile Radio Stations Below 800 MHz

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... announcing the effective date of those rules. DATES: 47 CFR 90.187 and 47 CFR 90.425 published at 78 FR 28749... of part 90 of the Commission's rules, FCC 13-52, published at 78 FR 28749, May 16, 2013. The OMB... COMMISSION 47 CFR Part 90 Private Land Mobile Radio Stations Below 800 MHz AGENCY: Final rule;...

  16. TEMPERATURE REGULATION IN THE UNRESTRAINED RABBIT DURING EXPOSURE TO 600 MHZ RADIOFREQUENCY RADIATION

    EPA Science Inventory

    Six male New Zealand white rabbits were individually exposed to 600 MHz radiofrequency (RF) radiation for 90 min in a waveguide exposure system at an ambient temperature (Ta) of 20 or 30 C. Immediately after exposure, the rabbit was removed from the exposure chamber and its colon...

  17. 47 CFR 27.303 - Upper 700 MHz commercial and public safety coordination zone.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 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...

  18. 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...

  19. 47 CFR 90.266 - Long distance communications on frequencies below 25 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Long distance communications on frequencies below 25 MHz. 90.266 Section 90.266 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Standards for Special Frequencies or Frequency Bands § 90.266 Long...

  20. 47 CFR 90.264 - Disaster communications between 2 and 10 MHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Disaster communications between 2 and 10 MHz. 90.264 Section 90.264 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Standards for Special Frequencies or Frequency Bands § 90.264 Disaster communications between...

  1. 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

  2. Radio emission of RRAT-pulsars at a frequency of 111 MHz

    NASA Astrophysics Data System (ADS)

    Losovsky, Boris; Dmitry Dumsky, Mr/.

    We will report about our resalts concerning the observations of a number of Rotating Radio Transient (RRAT) pulsars .These observations have been carried out at Large Phased Array of P.N. Lebedev Physical Institute at 111 MHz during 2010-2013 years. RRAT- pulsars were first discovered in archive Parkes Multibeam Pulsar Survey [1,2]and Arecibo Pulsar Survey[3] at higher frequency 1400 MHz and some pulsars were discovered at frequency of 350 MHz with Green Bank Telescope[4]. A characteristic feature of these pulsars is sporadic radio emission in rare active phase and no radio emission for a long time making it difficult to find periodicity .Fast Folding Algorithm processing of observations at 111 MHz shows that even in passive phase RRAT-pulsars generate weak radio emission with the period corresponding to the period of sporadic radio pulses observed in the active phase. The flux density of the radio emission of these pulsars in passive phase is rather small even at low frequency 111 MHz, that greatly complicates its registration at high frequencies since flux density of the RRAT- pulsars decreases with increasing frequency.\\ ȩnterline{References}\\ 1.McLaughlin M.A., Lyne A.G., Lorimer D.R. et al., 2006, Nature,439,817. 2.Keane E.F., Ludovici D.A., Eatough E.P. et al., 2010, MNRAS,401,1057. 3.Deneva J.S., Cordes J.M., McLaughlin M.A. et al., 2009,ApJ,703,2259. 4.Keane E.F.,McLaughlin M.A., Bull.Astr.Soc.India, 2011,39,1.

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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... Broadband License, the Upper 700 MHz D Block license, or both. (c) The Chiefs of the Public Safety and Homeland Security Bureau and the Wireless Telecommunications Bureau are delegated joint responsibility...

  9. 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

    ... Safety Broadband Licensee, the Operating Company, the Network Assets Holder, and the Upper 700 MHz D... Broadband License, the Upper 700 MHz D Block license, or both. (c) The Chiefs of the Public Safety and Homeland Security Bureau and the Wireless Telecommunications Bureau are delegated joint responsibility...

  10. 78 FR 77029 - Wireless Telecommunications Bureau Seeks Comment on a Proposal To License the 600 MHz Band Using...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Electronic Comment Filing System (ECFS). See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR... 77 FR 69934 November 21, 2012 (NPRM), the Commission sought public comment on creating a 600 MHz band... MHz Bands 78 FR 51559 August 20, 2013 (AWS-3 NPRM), WTB seeks comment on applying this approach. 4....

  11. 47 CFR 15.323 - Specific requirements for devices operating in the 1920-1930 MHz band.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... intended transmission and have a maximum reaction time less than 50xSQRT (1.25/emission bandwidth in MHz... reaction time shall be 35xSQRT (1.25/emission bandwidth in MHz) microseconds but shall not be required to... must incorporate a mechanism for monitoring the time and spectrum windows that its transmission...

  12. 47 CFR 15.323 - Specific requirements for devices operating in the 1920-1930 MHz sub-band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... intended transmission and have a maximum reaction time less than 50xSQRT (1.25/emission bandwidth in MHz... reaction time shall be 35xSQRT (1.25/emission bandwidth in MHz) microseconds but shall not be required to... must incorporate a mechanism for monitoring the time and spectrum windows that its transmission...

  13. 47 CFR 15.323 - Specific requirements for devices operating in the 1920-1930 MHz band.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... intended transmission and have a maximum reaction time less than 50xSQRT (1.25/emission bandwidth in MHz... reaction time shall be 35xSQRT (1.25/emission bandwidth in MHz) microseconds but shall not be required to... must incorporate a mechanism for monitoring the time and spectrum windows that its transmission...

  14. 47 CFR 15.323 - Specific requirements for devices operating in the 1920-1930 MHz band.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... intended transmission and have a maximum reaction time less than 50xSQRT (1.25/emission bandwidth in MHz... reaction time shall be 35xSQRT (1.25/emission bandwidth in MHz) microseconds but shall not be required to... must incorporate a mechanism for monitoring the time and spectrum windows that its transmission...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. A 300 MHz and 600 MHz proton NMR study of a 12 base pair restriction fragment: investigation of structure by relaxation measurements.

    PubMed Central

    Early, T A; Kearns, D R; Hillen, W; Wells, R D

    1980-01-01

    The 1H NMR spectrum of a 12 base pair DNA restriction fragment has been measured at 300 and 600 MHz and resonances from over 70 protons are individually resolved. Relaxation rate measurements have been carried out at 300 MHz and compared with the theoretical predictions obtained using an isotropic rigid rotor model with coordinates derived from a Dreiding model of DNA. The model gives results that are in excellent agreement with experiment for most protons when a 7 nsec rotational correlation time is used, although agreement is improved for certain base protons by using a shorter correlation time for the sugar group, or by increasing the sugar-base interproton distances. A comparison of non-selective and selective spin-lattice relaxation rates for carbon bound protons indicates that there is extensive spin diffusion even in this short DNA fragment. Examination of the spin-spin relaxation rates for the same type of proton on different base pairs reveals little sequence effect on conformation. PMID:6258152

  1. A BIPM/CIPM key comparison covering the calibration of ultrasonic hydrophones over the frequency range 1 MHz to 15 MHz

    NASA Astrophysics Data System (ADS)

    Zeqiri, Bajram; Lee, Nigel D.

    2002-11-01

    A central objective of the Mutual Recognition Arrangement (MRA), signed by national measurement institute (NMI) directors in 1999, is the establishment of the degrees of equivalence of national measurement standards held by each institute. International comparisons, known as key comparisons, represent the sole mechanism for establishing these degrees of equivalence. In this paper we describe a key comparison, undertaken under the auspices of the BIPM/CIPM Consultative Committee for Acoustics, Ultrasound, and Vibration, related to the realization of the acoustic pascal in water at ultrasonic frequencies. This is most appropriately achieved through a comparison of calibrations of stable transfer standard hydrophones; 1 mm active element bilaminar membrane hydrophones, being chosen for this purpose. With NPL acting as the pilot laboratory, two hydrophones were calibrated using the NPL primary standard laser interferometer and circulated sequentially to participant NMI laboratories in Germany, China, The Netherlands, and Denmark. Laboratories were asked to report values for the hydrophone open-circuit free-field sensitivity over the frequency range 1 MHz to 15 MHz. The principal calibration methods used by the NMIs were optical interferometry and/or two-transducer reciprocity. The key comparison process, its results, and the analysis used to derive the key comparison reference values, are all described in detail.

  2. Optimization of dynamic nuclear polarization experiments in aqueous solution at 15 MHz/9.7 GHz: a comparative study with DNP at 140 MHz/94 GHz.

    PubMed

    Türke, Maria-Teresa; Tkach, Igor; Reese, Marcel; Höfer, Peter; Bennati, Marina

    2010-06-14

    Dynamic nuclear polarization is emerging as a potential tool to increase the sensitivity of NMR aiming at the detection of macromolecules in liquid solution. One possibility for such an experimental design is to perform the polarization step between electrons and nuclei at low magnetic fields and then transfer the sample to a higher field for NMR detection. In this case, an independent optimization of the polarizer and detection set ups is required. In the present paper we describe the optimization of a polarizer set up at 15 MHz (1)H NMR/9.7 GHz EPR frequencies based on commercial hardware. The sample consists of the nitroxide radical TEMPONE-D,(15)N in water, for which the dimensions were systematically decreased to fit the homogeneous B(1) region of a dielectric ENDOR resonator. With an available B(1) microwave field up to 13 G we observe a maximum DNP enhancement of -170 at room temperature by irradiating on either one of the EPR lines. The DNP enhancement was saturated at all polarizer concentrations. Pulsed ELDOR experiments revealed that the saturation level of the two hyperfine lines is such that the DNP enhancements are well consistent with the coupling factors derived from NMRD data. By raising the polarizing field and frequencies 10-fold, i.e. to 140 MHz (1)H/94 GHz EPR, we reach an enhancement of -43 at microwave field strengths (B(1) approximately 5 G). The results are discussed in view of an application for a DNP spectrometer. PMID:20454734

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Observation of solar radio bursts using swept-frequency radiospectrograph in 20-40 MHz Band

    NASA Astrophysics Data System (ADS)

    Aoyama, Takashi; Oya, Hiroshi

    A new station for the observation of solar decametric radio bursts has been developed at Miyagi Vocational Training College in Tsukidate, Miyagi, Japan. Using the swept frequency radiospectrograph covering a frequency range from 20 MHz to 40 MHz within 200 msec, with bandwidth of 30 KHz, the radio outbursts from the sun have been currently monitored with colored dynamic spectrum display. After July 1982, successful observations provide the data which include all types of solar radio bursts such as type I, II, III, IV and V in the decametric wavelength range. In addition to these typical radio bursts, rising tone bursts with fast drift rate followed by strong type III bursts and a series of bursts repeating rising and falling tone bursts with slow drift rate have been observed.

  8. An electronically tuned, stable 8415-MHz dielectric resonator FET oscillator for space applications

    NASA Technical Reports Server (NTRS)

    Lakshminarayana, M.

    1988-01-01

    A voltage-controlled 8415 MHz FET oscillator stabilized by a dielectric resonator is described. The oscillator provides a linear electronic tuning range of over 3.2 MHz with a flat power output equal to +1.8 dBm (27 C nominal), a single-sideband noise to carrier ratio of -68 dBc/Hz at 1 kHz off carrier, and a frequency temperature coefficient of 0.54 part per million/C over a -24 to 75 C range. The oscillator withstood 150 krads(Si) of gamma radiation with no significant performance degradation. The overall performance of the oscillator is in many ways far superior to that of an equivalent bipolar oscillator for space applications.

  9. An electronically tuned, stable 8415 MHz dielectric resonator FET oscillator for space applications

    NASA Technical Reports Server (NTRS)

    Mysoor, Narayan R.

    1990-01-01

    A voltage-controlled 8415-MHz FET oscillator stabilized by a dielectric resonator is described. The oscillator provides over 3.2-MHz linear electronic tuning range with a flat power output equal to +1.8 dBm (27 C, nominal), a single-sideband noise-to-carrier ratio of -68 dBc/Hz at 1 kHz off carrier, and a frequency-temperature coefficient of 0.54 parts per million/C over a -24 C to 75 C range. The oscillator withstood 150 Krads (Si) of gamma radiation with no significant performance degradation. The overall performance of the FET oscillator is far superior in many ways to that of an equivalent bipolar oscillator for space applications. For space applications, the FET dielectric resonator oscillator (DRO) is preferred over bipolar DRO because of its lower DC power consumption, better thermal frequency stability, linear electronic tunability, and higher RF output power capability.

  10. Radio propagation at 900 MHz in urban areas: Models with a fixed frequency and experimental results

    NASA Astrophysics Data System (ADS)

    Olivier, P.; Tiffon, J.

    1984-09-01

    Models which describe multipath propagation are examined in order to design a 900 MHz mobile communication system adapted to urban areas. A justification of the experimental data treatment is derived from this analysis. The measurements were made at a fixed 855 MHz frequency, transmitting from three locations. The fast fluctuations of the received signals are well represented by a Rayleigh process, which means that there are practically no paths of direct transmission. The coherence length is 1 m. The statistical distribution of the average field is Gaussian and the normal deviation decreases with the distance emitter-receiver. The empiric Okumura-Hata prediction model agrees well with the experimental results, giving an average cell field decreasing with distance with a logarithmic law.

  11. 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. PMID:16785018

  12. Pump-seed synchronization for MHz repetition rate, high-power optical parametric chirped pulse amplification.

    PubMed

    Fattahi, Hanieh; Teisset, Catherine Yuriko; Pronin, Oleg; Sugita, Atsushi; Graf, Roswitha; Pervak, Vladimir; Gu, Xun; Metzger, Thomas; Major, Zsuzsanna; Krausz, Ferenc; Apolonski, Alexander

    2012-04-23

    We report on an active synchronization between two independent mode-locked lasers using a combined electronic-optical feedback. With this scheme, seed pulses at MHz repetition rate were amplified in a non-collinear optical parametric chirped pulse amplifier (OPCPA). The amplifier was seeded with stretched 1.5 nJ pulses from a femtosecond Ti:Sapphire oscillator, while pumped with the 1 ps, 2.9 µJ frequency-doubled output of an Yb:YAG thin-disk oscillator. The residual timing jitter between the two oscillators was suppressed to 120 fs (RMS), allowing for an efficient and broadband amplification at 11.5 MHz to a pulse energy of 700 nJ and an average power of 8 W. First compression experiment with 240 nJ amplified pulse energy resulted in a pulse duration of ~10 fs. PMID:22535076

  13. Optical breakdown of multilayer thin-films induced by ultrashort pulses at MHz repetition rates.

    PubMed

    Angelov, Ivan B; von Pechmann, Maximilian; Trubetskov, Michael K; Krausz, Ferenc; Pervak, Vladimir

    2013-12-16

    Multilayer coatings composed of TiO(2), Ta(2)O(5), HfO(2), or Al(2)O(3) as high-index materials and SiO(2) as low-index material were investigated for laser-induced damage using 1 ps, 5 µJ pulses generated by a mode-locked Yb:YAG thin-disk oscillator operating at a wavelength of 1030 nm and repetition rate of 11.5 MHz. Previously reported linear band gap dependence of damage threshold at kHz repetition rates was confirmed also for the MHz regime. Additionally, we studied the effect of electric field distribution inside of the layer stack. We did not observe any significant influence of thermal effects on the laser-induced damage threshold in this regime. PMID:24514719

  14. 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.

  15. 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.

  16. Characterization of a 40-MHz Focused Transducer with a Fiber Grating Laser Hydrophone

    PubMed Central

    Lau, Sien-Ting; Shao, Li-Yang; Chan, Helen Lai-Wa; Tam, Hwa-Yaw; Hu, Chang-Hong; Kim, Hyung-Ham; Liu, Ruibin; Zhou, Qifa; Shung, K. Kirk

    2009-01-01

    A novel fiber-optic hydrophone based on a dual-polarization, short-cavity fiber grating laser as the sensing element is described. Wet chemical etching was used to fabricate a thinned fiber sensor to extend its frequency response as well as spatial resolution. The lateral beam profile at the focal plane of a 40-MHz lens-focused lithium niobate (LiNbO3) transducer was measured with the fiber sensor, and a tomographic technique was used to compute the transducer profile, which is compared with that obtained by a PVDF hydrophone. The fiber hydrophone has a sensitivity of approximately −259 dB re 1V/µPa up to 40 MHz, which is higher than that of a commercial PVDF hydrophone. Moreover, it is capable of accurately characterizing the beam generated by high-frequency transducer. PMID:19126496

  17. 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.

  18. A semiconductor opening switch based generator with pulse repetitive frequency of 4 MHz.

    PubMed

    Wang, Gang; Su, Jiancang; Ding, Zhenjie; Yuan, Xuelin; Pan, Yafeng

    2013-12-01

    A MHz repetitive and nanosecond pulsed power generator based on the semiconductor opening switch (SOS) is developed, in which the pulse compression unit utilizes several Radio Frequency (RF) MOSFETs and a saturable Linear Transformer Driver (LTD). The RF MOSFETs are employed to obtain the forward pumping current pulses with the duration of tens of nanoseconds; the saturable LTD is used to raise the pulse voltage, to compress the pulse width and to pump SOS reversely. The SOS assembly cuts off the reverse current in a few nanoseconds, leading to a narrow output pulse on an external load. The experimental results show that the amplitude of the output pulse on a 106 Ω resistive load is about 3.8 kV and the width is 2 ns. Due to the repetitive ability of the RF MOSFETs, the generator can operate at a repetitive frequency of higher than 4 MHz in burst mode. PMID:24387463

  19. Dicke’S Superradiance in Astrophysics. II. The OH 1612 MHz Line

    NASA Astrophysics Data System (ADS)

    Rajabi, Fereshteh; Houde, Martin

    2016-09-01

    We apply the concept of superradiance that was introduced by Dicke in 1954 to the OH molecule 1612 MHz spectral line, which is often used for the detection of masers in the circumstellar envelopes of evolved stars. Because the detection of 1612 MHz OH masers in the outer shells of envelopes of these stars implies the existence of a population inversion and a high level of velocity coherence, and that these are two necessary requirements for superradiance, we investigate whether superradiance can also happen in these regions. Superradiance is characterized by high-intensity, spatially compact, burst-like features taking place over timescales on the order of seconds to years, depending on the size and physical conditions present in the regions harboring such sources of radiation. Our analysis suggests that superradiance provides a valid explanation for previous observations of intensity flares detected in that spectral line for the U Orionis Mira star and the IRAS 18276-1431 preplanetary nebula.

  20. 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.

  1. 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 3⅛″ 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.

  2. 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

  3. 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.

  4. 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.

  5. 916 MHz electromagnetic field exposure affects rat behavior and hippocampal neuronal discharge☆

    PubMed Central

    Hao, Dongmei; Yang, Lei; Chen, Su; Tian, Yonghao; Wu, Shuicai

    2012-01-01

    Wistar rats were exposed to a 916 MHz, 10 W/m2 mobile phone electromagnetic field for 6 hours a day, 5 days a week. Average completion times in an eight-arm radial maze were longer in the exposed rats than control rats after 4–5 weeks of exposure. Error rates in the exposed rats were greater than the control rats at 6 weeks. Hippocampal neurons from the exposed rats showed irregular firing patterns during the experiment, and they exhibited decreased spiking activity 6–9 weeks compared with that after 2–5 weeks of exposure. These results indicate that 916 MHz electromagnetic fields influence learning and memory in rats during exposure, but long-term effects are not obvious. PMID:25657684

  6. Design of the 26.7 MHz rf cavity for RHIC

    SciTech Connect

    Rose, J.; Brodowski, J.; Deng, D.P.; Kwiatkowski, S.; Pirkl, W.; Ratti, A.

    1995-05-01

    The accelerating system for RHIC operates at 26.7 MHz (h = 342) and must capture the injected beam, accelerate it to top energy, and shorten the bunches prior to rebucketing into the storage (h = 2508) system. These different functions set the design parameters of the cavity. The frequency of 26.7 MHz has been chosen in order to provide large enough buckets to capture the injected beam from the AGS and a large linear region for debunching during a bunch rotation at top energy. Provision of the large linear region also dictates the voltage requirement of 400 kV per cavity. The cavity must be tuned {approximately}90 kHz to compensate for the change in speed of the gold beam.

  7. Surface-acoustic-wave filter with a center frequency of 960 MHz

    NASA Astrophysics Data System (ADS)

    Guliaev, Iu. V.; Fedorets, V. N.; Buliuk, A. N.

    1985-05-01

    The paper reports the experimental characteristics of a SAW bandpass filter operating at the third harmonic with a center frequency of 960 MHz. The filter, fabricated by optical lithography, has a passband of 7 MHz at the 3 dB level; the insertion loss is 15 dB; the sidelobe suppression is at least 43 dB; the shape factor of the amplitude-frequency response curve at the 3 and 40 dB levels is 2.6; and the nonuniformity of this curve in the passband is 0.6 dB. Experimental results indicate that SAW absorption in the metal films from which the electrodes and the electrostatic shield between converters are fabricated must be taken into account in the design of devices for the microwave range.

  8. 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.

  9. 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.

  10. 4D Optical Coherence Tomography based Microangiography achieved by 1.6 MHz FDML Swept source

    PubMed Central

    Zhi, Zhongwei; Qin, Wan; Wang, Jingang; Wei, Wei; Wang, Ruikang K.

    2015-01-01

    We demonstrate the use of an ultra-high speed swept-source optical coherence tomography (OCT) to achieve optical microangiography (OMAG) of microcirculatory tissue beds in vivo. The system is based on a 1310 nm Fourier domain mode locking (FDML) laser with 1.6MHz A-line rate, providing a frame rate of 3.415 KHz, an axial resolution of ~10 µm and signal to noise ratio of 102 dB. Motion from blood flow causes change in OCT signals between consecutive B-frames acquired at the same location. Intensity based inter-frame subtraction algorithm is applied to extract blood flow from tissue background without any motion correction. We demonstrate the capability of this 1.6 MHz OCT system for 4D optical microangiography of in vivo tissue at a volume rate of 4.7 volumes/s (volume size: 512×200×720 voxels). PMID:25872072

  11. Efficient Dynamic Nuclear Polarization at 800 MHz/527 GHz with Trityl-Nitroxide Biradicals.

    PubMed

    Mathies, Guinevere; Caporini, Marc A; Michaelis, Vladimir K; Liu, Yangping; Hu, Kan-Nian; Mance, Deni; Zweier, Jay L; Rosay, Melanie; Baldus, Marc; Griffin, Robert G

    2015-09-28

    Cross-effect (CE) dynamic nuclear polarization (DNP) is a rapidly developing technique that enhances the signal intensities in magic-angle spinning (MAS) NMR spectra. We report CE DNP experiments at 211, 600, and 800 MHz using a new series of biradical polarizing agents referred to as TEMTriPols, in which a nitroxide (TEMPO) and a trityl radical are chemically tethered. The TEMTriPol molecule with the optimal performance yields a record (1) H NMR signal enhancement of 65 at 800 MHz at a concentration of 10 mM in a glycerol/water solvent matrix. The CE DNP enhancement for the TEMTriPol biradicals does not decrease as the magnetic field is increased in the manner usually observed for bis-nitroxides. Instead, the relatively strong exchange interaction between the trityl and nitroxide moieties determines the magnetic field at which the optimum enhancement is observed. PMID:26268156

  12. Computer-aided studies of the ALS 500 MHz storage ring cavity

    SciTech Connect

    Lo, C.C.; Taylor, B.

    1989-03-01

    The design of the ALS storage ring 500 MHz cavity has been modeled with Mafia and Urmel codes. The effects of the holes cut for the drive port, the higher order mode damping port, the probe port and tuner plunger were modeled with the Mafia codes. The frequency dependence on the shape and spacing of the nose cones and the general shape of the cavity were modeled with Urmel codes. 9 refs., 7 figs., 1 tab.

  13. Superradiance on the mHz linewidth clock transition in 87Sr

    NASA Astrophysics Data System (ADS)

    Norcia, Matthew; Winchester, Matthew; Cline, Julia; Thompson, James

    2016-05-01

    In this talk, I will discuss our recent experimental explorations of superradiant emission from the mHz linewidth clock transition in an ensemble of cold 87 Sr atoms confined within a high-finesse optical cavity. Recent proposals suggest that superradiant lasers based on such dipole-forbidden transitions in alkaline earth atoms could achieve linewidths below the current state of the art, with reduced sensitivity to environmental perturbations.

  14. Plasma Response to the Application of 30 MHz RF Power in the NSTX Device

    SciTech Connect

    J.R. Wilson; R.E. Bell; S. Bernabei; J.C. Hosea; B.P. LeBlanc; T.K. Mau; J. Menard; M. Ono; F. Paoletti; R. Pinsker; C.K. Phillips; A. Rosenberg; P.M. Ryan; S. Sabbagh; D. Stutman; D.W. Swain; J.B. Wilgen; Y. Takase

    2001-05-08

    Radio-frequency power at 30 MHz has been applied in a variety of situations to National Spherical Torus Experiment (NSTX) plasmas. The response of the plasma is observed in order to study both the physics of High Harmonic Fast Wave (HHFW) heating and as a tool to extend the performance of NSTX plasmas. In this paper we will discuss the progress made to date towards these goals.

  15. High power input coupler development for BEPCII 500 MHz superconducting cavity

    NASA Astrophysics Data System (ADS)

    Huang, Tongming; Pan, Weimin; Ma, Qiang; Wang, Guangwei; Dai, Xuwen; Zhang, Zhanjun; Furuya, T.; Mitsunobu, S.

    2010-11-01

    A high power input coupler for a 500 MHz superconducting cavity (SCC) of the upgrade project of Beijing Electron Positron Collider (BEPCII) has been developed in China. Several prototypes have been fabricated and tested successfully. A maximum of 420 kW continuous wave (CW) RF power in traveling wave (TW) mode was achieved in the high power test. The detailed design, fabrication and test of the coupler are described in this paper.

  16. Design of a 325 MHz half wave resonator prototype at IHEP

    NASA Astrophysics Data System (ADS)

    Zhang, Xin-Yin; Pan, Wei-Min; Wang, Guang-Wei; Xu, Bo; Zhao, Guang-Yuan; He, Fei-Si; Li, Zhong-Quan; Ma, Qiang; Dai, Jin; Chen, Xu; Mi, Zheng-Hui; Sha, Peng; Lin, Hai-Ying; Wang, Qun-Yao; Liu, Ya-Ping; Xue, Zhou; Huang, Xuan-Fang; Wang, Mu-Yuan; Sun, Yi

    2016-08-01

    A 325 MHz β = 0.14 superconducting half-wave resonator prototype has been developed at the Institute of High Energy Physics, Beijing, which can be applied in the low energy section of continuous wave high current proton linear accelerators. The electromagnetic design, multipacting simulation, mechanical optimization and fabrication are introduced in detail. Test results at room temperature and 4.2 K, and a comparison between measured and simulated results, are analyzed in this paper.

  17. A 70-MHz 32-b microprocessor with 1. 0-. mu. m BiCMOS macrocell library

    SciTech Connect

    Hotta, T.; Bandoh, T. . Hitachi Research Lab.); Hotta, A.; Nakano, T. ); Iwamoto, S.; Adachi, S. )

    1990-06-01

    A custom 529K-transistor microprocessor with a five-stage pipeline has been implemented on a 12.98-mm{sup 2} die. Employing BiCMOS macrocells, a 32-b execution unit, extendible ROM, RAM a PLL clock generator with bipolar drivers, and sense circuits, a peak performance of 70 MIPS is achieved. Power consumption is 2.1 W at 40 MHz.

  18. Aero-optics: Simultaneous MHz Rate Planar Flow Visualization and Optical Wavefront Measurements

    NASA Astrophysics Data System (ADS)

    Thurow, Brian; Samimy, Mo; Lempert, Walter; Harris, Scott; Widiker, Jeff; Duncan, Bradley

    2002-11-01

    In response to a need for more detailed understanding of aero-optic effects in realistic flows (high-speed and compressible), we apply very recently developed MHz rate planar diagnostic techniques to simultaneously perform flow visualization and wavefront measurement on a Mach 1.3 rectangular jet. A custom-built pulse burst laser is used to produce 17 pulses (10 nsec duration) with inter-pulse timing of 4 microseconds (250 kHz). The pulses were formed into a laser sheet and illuminated the mixing layer in a streamwise plane of a Mach 1.3 rectangular, aspect ratio 3 jet. Images were captured using a Dalsa 64K1M camera that can record 17 images at framing rates as high as 1 MHz. Optical wavefronts were measured at rates up to 1 MHz using a newly designed Shack-Hartmann (SH) wavefront sensor. A 10 mW HeNe laser beam was spatially filtered and expanded to a 2.5 cm diameter and passed through the center of the rectangular jet 8 nozzle exit heights downstream of the nozzle exit. A lenslet array (1.024 mm pitch, 260 mm f. l.) and a -1000 mm f. l. lens are used to form a grid pattern of dots onto a PSI-IV camera capable of capturing 28 frames at 1 MHz framing rates. The camera was operated at 500 kHz and imaged a 6 x 6 pattern of dots. The displacement of each dot corresponds to the local wavefront tilt induced by the jet as the initially planar wavefront passes through the flow. Results are being analyzed to obtain a correlation between turbulence structures contained in the mixing layer of the jet and the optical distortion produced by these structures.

  19. 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. PMID:21842584

  20. 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.

  1. 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

  2. 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. PMID:25577980

  3. 47 CFR 80.1061 - Special requirements for 406.0-406.1 MHz EPIRB stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... specified in § 80.1101(c)(5). (b) The 406.0-406.1 EPIRB must contain as an integral part a “homing” beacon... document described in paragraph (a) of this section. The 121.500 MHz “homing” beacon must have a continuous... the EPIRB identification code addressed to: NOAA/SARSAT Beacon Registration, E/SP3, Federal Building...

  4. 47 CFR 80.1061 - Special requirements for 406.0-406.1 MHz EPIRB stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... specified in § 80.1101(c)(5). (b) The 406.0-406.1 EPIRB must contain as an integral part a “homing” beacon... document described in paragraph (a) of this section. The 121.500 MHz “homing” beacon must have a continuous... the EPIRB identification code addressed to: NOAA/SARSAT Beacon Registration, E/SP3, Federal Building...

  5. 47 CFR 80.1061 - Special requirements for 406.0-406.1 MHz EPIRB stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specified in § 80.1101(c)(5). (b) The 406.0-406.1 EPIRB must contain as an integral part a “homing” beacon... document described in paragraph (a) of this section. The 121.500 MHz “homing” beacon must have a continuous... the EPIRB identification code addressed to: NOAA/SARSAT Beacon Registration, E/SP3, Federal Building...

  6. A compact high efficiency 8 kW 325 MHz power amplifier for accelerator applications

    NASA Astrophysics Data System (ADS)

    Mishra, Jitendra Kumar; Ramarao, B. V.; Pande, Manjiri M.; Singh, P.

    2014-11-01

    A solid state RF power amplifier (SSRFPA) has been designed and developed for 8 kW RF power at 325 MHz. The work was carried out to achieve high efficiency (over 70% efficiency), high gain and compact size for the amplifier module. The sub-components of this amplifier like a 1 kW amplifier module at 325 MHz, an 8-way RF power combiner rated for 8 kW RF power and a micro-strip based power divider have been designed and developed in-house. The size of the amplifier is miniaturized by incorporating innovative design techniques and proper selection of the substrate material in the input/output matching networks. Measured power gain and conversion efficiency of the solid state RF power amplifier module at 1.06 kW output is 21.7 dB and 73.2%, respectively. A coaxial line based 8-way Wilkinson power combiner has been designed and developed. Return loss of the combiner at the output (combined) port is 26.4 dB at 325 MHz. Transmission parameters of the combiner from each input (splitting) port to output port are 9.1 dB±0.15 dB. This amplifier uses a pre-driver of 20 W and a driver amplifier of 150 W. Total power gain and efficiency of 8 kW SSRFPA have been 92.3 dB (including the driver stages) and 68.3%, respectively. The harmonic content in the RF output is less than -50 dBc for all the harmonics. Main features of this development are high power density (kW/cm3), large value for kW/module, high efficiency (68.3%) for 8 kW SSRFPA at 325 MHz and rugged operation.

  7. 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.

  8. 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. PMID:23485349

  9. Development of lead-free single-element ultrahigh frequency (170 – 320 MHz) ultrasonic transducers

    PubMed Central

    Lam, Kwok Ho; Ji, Hong Fen; Zheng, Fan; Ren, Wei; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    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 320 MHz. The center frequency of > 300 MHz 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 −6 dB 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 −60 dB. In addition to the pulse-echo measurement, a 6-μm tungsten wire phantom was also imaged with a 205 MHz transducer to demonstrate the imaging capability. The measured −6 dB axial and lateral resolutions were found to be 12 μm and 50 μm, 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. PMID:23485349

  10. The Expansion of Arecibo in Summer 2008: A Receiver at 600-1200 MHz

    NASA Astrophysics Data System (ADS)

    Jones, Kristen; Rajagopalan, G.; Whitlow, D.

    2009-01-01

    The purpose of this project is to investigate the radio frequency interference (RFI) environment seen through the Arecibo telescope and recommend necessary limits for a cooled receiver in the 600-1200 MHz regime. Preliminary discriminatory measurements were made using the Hilltop RFI Monitoring system. Strong TV and cell phone signals dominate the band from 450 to 1200 MHz. We seek to overcome this RFI for a number of reasons. It is feasible that the dish will see less troublesome RFI than the Hilltop Monitoring sees. Additionally, this region is astronomically essential, as it is ideal for both pulsar research and high z HI studies. We have constructed an antenna and receiver optimized in the 600-1200 MHz band and have installed them in the Gregorian Dome. We are currently working to focus and calibrate the receiver and to produce spectra across the band from sample regions of the entire Arecibo beam. This information will guide the limits and filters necessary to make a cooled receiver functional in this useful region. We graciously thank the National Science Foundation's Research Experience for Undergraduates program for funding this research.

  11. Measurements at TRIUMF on a 80 MHz Cavity Model for the CERN PS Upgrade for LHC.

    NASA Astrophysics Data System (ADS)

    Mitra, A. K.; Poirier, R. L.; Losito, R.

    1997-05-01

    The RF system of the CERN PS being upgraded to bunch a beam that can be captured by the SPS 200 MHz RF system for injection into LHC. Two identical 80 MHz cavities are part of this PS upgrade programme. At CERN, the cavity has been designed using SUPERFISH and MAFIA concerning its shape, tuning devices and amplifier coupling loop. TRIUMF has built a simplified full-scale, copper-lined, wooden model, designed such that the field patters of the fundamental accelerating mode and the longitudinal modes agree closely to CERN cavity ones. The aim of constructing the wooden model was primarily to check the design of the capacitive tuners, the power coupling loop and the HOM dampers for the longitudinal modes up to 1 GHz. The results of the measurements were used to define the parameters of the tuners and a reliable model to describe the interaction of the coupling look with the fundamental mode of the final CERN cavity. Five quarter-wave antennae are adequate to damp the first fifteen longitudinal modes. In order not to decrease the shunt impedance of the fundamental mode by more than 5%, a three-element filter has been used with the antenna which damps the first longitudinal mode at 256 MHz.

  12. Great progress in developing 500 MHz single cell superconducting cavity in China

    NASA Astrophysics Data System (ADS)

    Liu, JianFei; Hou, HongTao; Mao, DongQing; Feng, ZiQiang; Ma, ZhenYu; Luo, Chen; Zhao, ShenJie; Zhao, YuBin; Yu, HaiBo; Yin, Bo; Zhang, ZhiGang; Zheng, Xiang; Li, Zheng

    2011-12-01

    Superconducting cavities have been adopted in many kinds of accelerator facilities such as synchrotron radiation light source, hard X-ray free electron laser linac, colliders and energy recovery linacs (ERL). The 500 MHz superconducting cavities will be a candidate to be installed in the high current accelerators and high current ERLs for their large beam aperture, low higher order modes impedance and high current threshold value. This paper presents great progress in the whole sequence of developing 500 MHz superconducting cavity in China. It describes the first in-house successful development of 500 MHz single cell superconducting cavity including the deep-drawing of niobium half cells, electron beam wielding of cavity, surface preparations and vertical testing. The highest accelerating gradient of the fabricated cavity #SCD-02 higher than 10 MV/m was obtained while the quality factor was better than 4×108 at 4.2 K, which has reached the world level of the same kind of cavities.

  13. Sustaining GHz oscillation of carbon nanotube based oscillators via a MHz frequency excitation.

    PubMed

    Motevalli, Benyamin; Taherifar, Neda; Liu, Jefferson Zhe

    2016-05-20

    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. PMID:27070404

  14. Ultrasonic imaging using air-coupled P(VDF/TrFE) transducers at 2 MHz.

    PubMed

    Takahashi, Sadayuki; Ohigashi, Hiroji

    2009-05-01

    A reflection non-contact ultrasonic microscope system working both in amplitude and phase difference modes at 2 MHz has been developed using an air-coupled concave transducer made of piezoelectric polymer films of poly(vinylidene fluoride/trifluoroethylene) [P(VDF/TrFE)]. The transducer is composed of three 95 microm-thick P(VDF/TrFE) films stacked together, each of which is activated electrically in parallel by a driving source. The transducer has a wide aperture angle of 140 degrees and a focal length of 10mm. The measured two-way transducer insertion loss is 80 dB at 1.83 MHz. Despite 20 dB higher insertion loss than that estimated from Mason's equivalent circuit, we have obtained clear amplitude acoustic images of a coin with transverse resolution of 150 microm, and clear phase difference acoustic images of the rough surface of a paper currency bill with depth resolution of sub-micrometer. Using two planar transducers of P(VDF/TrFE), we have also successfully measured in through-transmission mode the sound velocity and absorption of a 3mm-thick silicone-rubber plate. The present study proves that, owing to its low acoustic impedance and flexibility, P(VDF/TrFE) piezoelectric film is very useful for high frequency acoustic imaging in air in the MHz range. PMID:19215951

  15. 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.

  16. Performance of an LPD prototype detector at MHz frame rates under Synchrotron and FEL radiation

    NASA Astrophysics Data System (ADS)

    Koch, A.; Hart, M.; Nicholls, T.; Angelsen, C.; Coughlan, J.; French, M.; Hauf, S.; Kuster, M.; Sztuk-Dambietz, J.; Turcato, M.; Carini, G. A.; Chollet, M.; Herrmann, S. C.; Lemke, H. T.; Nelson, S.; Song, S.; Weaver, M.; Zhu, D.; Meents, A.; Fischer, P.

    2013-11-01

    A MHz frame rate X-ray area detector (LPD — Large Pixel Detector) is under development by the Rutherford Appleton Laboratory for the European XFEL. The detector will have 1 million pixels and allows analogue storage of 512 images taken at 4.5 MHz in the detector front end. The LPD detector has 500 μm thick silicon sensor tiles that are bump bonded to a readout ASIC. The ASIC's preamplifier provides relatively low noise at high speed which results in a high dynamic range of 105 photons over an energy range of 5-20 keV. Small scale prototypes of 32 × 256 pixels (LPD 2-Tile detector) and 256 × 256 pixels (LPD supermodule detector) are now available for X-ray tests. The performance of prototypes of the detector is reported for first tests under synchrotron radiation (PETRA III at DESY) and Free-Electron-Laser radiation (LCLS at SLAC). The initial performance of the detector in terms of signal range and noise, radiation hardness and spatial and temporal response are reported. The main result is that the 4.5 MHz sampling detection chain is reliably working, including the analogue on-chip memory concept. The detector is at least radiation hard up to 5 MGy at 12 keV. In addition the multiple gain concept has been demonstrated over a dynamic range to 104 at 12 keV with a readout noise equivalent to < 1 photon rms in its most sensitive mode.

  17. Spreading dynamics of a partially wetting water film atop a MHz substrate vibration

    NASA Astrophysics Data System (ADS)

    Altshuler, Gennady; Manor, Ofer

    2015-10-01

    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 θ3/We, where θ is the three phase contact angle of the liquid with the solid substrate and We ≡ ρU2H/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 (θ3/We < 1); otherwise (θ3/We > 1), the dynamics of the film is governed by the capillary mechanism.

  18. A 40-100 MHz B-scan ultrasound backscatter microscope for skin imaging.

    PubMed

    Turnbull, D H; Starkoski, B G; Harasiewicz, K A; Semple, J L; From, L; Gupta, A K; Sauder, D N; Foster, F S

    1995-01-01

    There is a growing interest in high resolution, subsurface imaging of cutaneous tissues using higher frequency ultrasound, and several commercial systems have been developed recently which operate at 20 MHz. Some of the possible applications of higher frequency skin imaging include tumour staging, boundary definition, and studies of the response of tumours to therapy, investigations of inflammatory skin conditions such as psoriasis and eczema, and basic studies of skin aging, sun damage and the effects of irritants. Investigation of these areas is quite new, and the role of ultrasound skin imaging is continuing to evolve. Lateral resolution in the 20 MHz imaging systems ranges from 200 to 300 microns, which limits imaging applications to cutaneous structures which are relatively large in size. In this paper, a real-time ultrasound backscatter microscope (UBM) for skin imaging is described which operates in the 40-100 MHz range, providing axial resolution between 17 and 30 microns and lateral resolution between 33 and 94 microns. This improvement in resolution over current skin ultrasound systems should prove useful in determining the margins of small skin lesions, and in obtaining more precise, in vivo skin thickness measurements to characterize nonmalignant skin disease. Example images of normal skin, seborrhoeic keratosis and malignant melanoma illustrate the imaging potential of this system. PMID:7754581

  19. PROPERTIES OF PHANTOM TISSUE-LIKE POLYMETHYLPENTENE IN THE FREQUENCY RANGE 20–70 MHZ

    PubMed Central

    Madsen, Ernest L; Deaner, Meagan E; Mehi, James

    2011-01-01

    Quantitative ultrasound (QUS) has been employed to characterize soft tissues at ordinary abdominal ultrasound frequencies (2–15 MHz) and is beginning application at high frequencies (20–70 MHz). For example, backscatter and attenuation coefficients can be estimated in vivo using a reference phantom. At high frequencies it is crucial that reverberations do not compromise the measurements. Such reverberations can occur between the phantom's scanning window and transducer components as well as within the scanning window between its surfaces. Transducers are designed to minimize reverberations between the transducer and soft tissue. Thus, the acoustic impedance of a phantom scanning window should be tissue-like; polymethylpentene (TPX) is commonly used because of its tissue-like acoustic impedance. For QUS it is also crucial to correct for the transmission coefficient of the scanning window. Computation of the latter requires knowledge of the ultrasonic properties, viz, density, speed and attenuation coefficients. This work reports values for the ultrasonic properties of two versions of TPX over the high frequency range. One form (TPX film) is used as a scanning window on high frequency phantoms, and at 40 MHz and 22°C was found to have an attenuation coefficient of 120 dB/cm and a propagation speed of 2093 m/s. PMID:21723451

  20. 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.

  1. 250 MHz/GHz scintillation parameters in the equatorial, polar, and auroral environments. Environmental research papers

    SciTech Connect

    Basu; MacKenzie, E.; Basu; Costa, E.; Fougere, P.F.

    1986-03-28

    Ionospheric scintillation effects encountered in the equatorial-anomaly crest, polar-cap, and auroral regions have been contrasted to provide information for the design and evaluation of the performance of satellite communication links in these regions. The equatorial-anomaly region is identified as the most-disturbed irregularity environment where the amplitude and phase structures of VHF/L-band scintillations are primarily dictated by the strength of scattering rather than ionospheric motion. In the anomaly region, the spectra of intense amplitude scintillations at VHF and L-band are characterized by uniform power spectral density from the lowest frequency (10 MHz) to 4 Hz at VHF and to 1 Hz at L-band and steep rolloff at higher fluctuation frequencies with power law indices of -5 to 07. Such structures are compatible with intensity decorrelation times of 0.1 and 0.3 sec at VHF and L-band frequencies, respectively. The phase spectra are described by power-law variation of psd with frequency with typical spectral indices of -2. 4. The strong scattering at VHF induces extreme phase rates of 200 deg. in 0.1 sec. The 90th percentile values of rms phase deviation at 250 MHz with 100-sec detrend are found to be 16 rads in the early evening hours whereas amplitude scintillation can cover the entire dynamic range of 30 dB not only at 250 MHz but at L-band as well.

  2. 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.

  3. Temperature regulation in the unrestrained rabbit during exposure to 600-MHz radiofrequency radiation

    SciTech Connect

    Gordon, C.J.; Long, M.D.; Fehlner, K.S.

    1986-01-01

    Six male New Zealand white rabbits were individually exposed to 600-MHz radiofrequency (RF) radiation for 90 min in a waveguide exposure system at an ambient temperature (Ta) of 20 or 30 C. Immediately after exposure, the rabbit was removed from the exposure chamber and its colonic and ear skin temperatures were quickly measured. The whole-body specific absorption rate (SAR) required to increase colonic and ear skin temperature was determined. At a Ta of 20 C, the threshold SAR for elevating colonic and ear skin temperature was 0.64 and 0.26 W/kg, respectively. At a Ta of 30 C, the threshold SARs were slightly less than at 20 C, with values of 0.26 W/kg for elevating colonic temperature and 0.19 W/kg for elevating ear skin temperature. The relationship between heat load and elevation in deep body temperature shown in the study at 600 MHz is similar to past studies that employed much-higher frequencies of RF radiation (2450-2884 MHz).

  4. 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.

  5. 76 FR 49364 - Fixed and Mobile Services in the Mobile Satellite Service Bands at 1525-1559 MHz and 1626.5-1660...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ..., published at 76 FR 31252, May 31, 2011. This is a summary of the Commission's document, Report No. 2932... COMMISSION 47 CFR Parts 1, 2, and 25 Fixed and Mobile Services in the Mobile Satellite Service Bands at 1525... Satellite Service Bands at 1525-1559 MHz and 1626.5-1660.5 MHz, 1610-1626.5 MHz and 2483.5-2500 MHz,...

  6. 47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15,...

  7. 47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15,...

  8. 47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15,...

  9. 47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15,...

  10. 47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15,...

  11. 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...

  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 27.1176 - 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...

  14. Development of calibration techniques for ultrasonic hydrophone probes in the frequency range from 1 to 100 MHz

    PubMed Central

    Umchid, S.; Gopinath, R.; Srinivasan, K.; Lewin, P. A.; Daryoush, A. S.; Bansal, L.; El-Sherif, M.

    2009-01-01

    The primary objective of this work 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 and validation of a novel, 100 MHz calibration technique the innovative elements of this research include implementation and testing of a prototype FO sensor with an active diameter of about 10 μm that exhibits uniform sensitivity over the considered frequency range and does not require any spatial averaging corrections up to about 75 MHz. The results of the calibration measurements are presented and it is shown that the optimized calibration technique allows the sensitivity of the hydrophone probes to be determined as a virtually continuous function of frequency and is also well suited to verify 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. PMID:19110289

  15. Solar U- and J- Bursts at the Frequencies 10-30MHz

    NASA Astrophysics Data System (ADS)

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

    2006-08-01

    In the present report we discuss the results of observations of solar U- and J- bursts over the frequency range 10-30MHz, which have been obtained within the framework of an international observational campaign in June - August, 2004 at the radio telescope UTR-2 (Kharkov, Ukraine). We succeed to observe these types of bursts for the first time at such a low frequencies due to combination of large effective area of the radio telescope and high sensitivity of the new back-end. During June - August, 2004 about 30 U- and J- bursts were registered, and only 5 of them were confidently identified as U-bursts that may speak about the relative sparsity of the latter at mentioned frequencies. Both the isolated bursts and their sequences were observed. On average the turning frequencies lay in the range 10-22 MHz that corresponds to the arches heliocentric heights of 1.6-2.2 solar radii. In some sequences the bursts turning frequency was stable that may indicate the arch stability, while in others the turning frequency had tendency to vary from burst to burst. Durations of U- and J- bursts did not differ from those of usual Type III bursts (3-7s), while the drift rates of an ascending arm (on the average -1MHz/ s) was a little bit lower, than those of ordinary Type III bursts in this range. The harmonic structure of U- and J- bursts, and also Jb-J pairs (analogous to IIIb-III pairs) were registered. Also L-shaped bursts (Leblanc and Hoyos, 1985) were recorded. A specific feature of L-shaped bursts is prolonged zero-drift region on their dynamic spectra. The sizes and configurations of the arches were estimated on the base of obtained data. Possible explanations of the observed properties of U- and J- bursts are discussed.

  16. Thrombolysis using multi-frequency high intensity focused ultrasound at MHz range: an in vitro study

    NASA Astrophysics Data System (ADS)

    Suo, Dingjie; Guo, Sijia; Lin, Weili; Jiang, Xiaoning; Jing, Yun

    2015-09-01

    High intensity focused ultrasound (HIFU) based thrombolysis has emerged as a promising drug-free treatment approach for ischemic stroke. The large amount of acoustic power required by this approach, however, poses a critical challenge to the future clinical translation. In this study, multi-frequency acoustic waves at MHz range (near 1.5 MHz) were introduced as HIFU excitations to reduce the required power for treatment as well as the treatment time. In vitro bovine blood clots weighing around 150 mg were treated by single-frequency and multi-frequency HIFU. The pulse length was 2 ms for all experiments except the ones where the duty cycle was changed. It was found that dual-frequency thrombolysis efficiency was statistically better than single-frequency under the same acoustic power and excitation condition. When varying the acoustic power but fixing the duty cycle at 5%, it was found that dual-frequency ultrasound can save almost 30% power in order to achieve the same thrombolysis efficiency. In the experiment where the duty cycle was increased from 0.5% to 10%, it was shown that dual-frequency ultrasound can achieve the same thrombolysis efficiency with only half of the duty cycle of single-frequency. Dual-frequency ultrasound could also accelerate the thrombolysis by a factor of 2-4 as demonstrated in this study. No significant differences were found between dual-frequencies with different frequency differences (0.025, 0.05, and 0.1 MHz) and between dual-frequency and triple-frequency. The measured cavitation doses of dual-frequency and triple-frequency excitations were at about the same level but both were significantly higher than that of single-frequency.

  17. 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).

  18. 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}.

  19. Mechanism of lethal action of 2,450-MHz radiation on microorganisms.

    PubMed Central

    Vela, G R; Wu, J F

    1979-01-01

    Various bacteria, actinomycetes, fungi, and bacteriophages were exposed to microwaves of 2,450 +/- 20 MHz in the presence and in the absence of water. It was found that microorganisms were inactivated only when in the presence of water and that dry or lyophilized organisms were not affected even by extended exposures. The data presented here prove that microorganisms are killed by "thermal effect" only and that, most likely, there is no "nonthermal effect"; cell constituents other than water do not absorb sufficient energy to kill microbial cells. PMID:453828

  20. 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.