WorldWideScience

Sample records for vhf stations microwave

  1. Final environmental assessment for vegetation control at VHF stations, microwave stations, electrical substations, and pole yards

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-13

    Southwestern Power Adm. operates very high frequency (VHF) and microwave radio stations, electrical substations, and pole yards for electric power transmission throughout AR, MO, and OK. Vegetation growth at the stations must be suppressed for safety of operation and personnel. Southwestern has been using a combination of mechanical/manual and herbicide control for this purpose; Federally- mandated reductions in staff and budgetary resources require Southwestern to evaluate all potentially efficient methods for vegetation control. Three alternatives were examined: no action, mechanical/manual control, and (proposed) a combination of mechanical/manual and herbicide control. Environmental impacts on air and water quality, wetlands, wildlife, endangered species, archaeological and other resources, farmland, human health, transportation, etc. were evaluated.

  2. 2-D inner-shelf current observations from a single VHF WEllen RAdar (WERA) station

    Science.gov (United States)

    Voulgaris, G.; Kumar, N.; Gurgel, K.-W.; Warner, J.C.; List, J.H.

    2011-01-01

    The majority of High Frequency (HF) radars used worldwide operate at medium to high frequencies (8 to 30 MHz) providing spatial resolutions ranging from 3 to 1.5 km and ranges from 150 to 50 km. This paper presents results from the deployment of a single Very High Frequency (VHF, 48 MHz) WEllen RAdar (WERA) radar with spatial resolution of 150 m and range 10-15 km, used in the nearshore off Cape Hatteras, NC, USA. It consisted of a linear array of 12 antennas operating in beam forming mode. Radial velocities were estimated from radar backscatter for a variety of wind and nearshore wave conditions. A methodology similar to that used for converting acoustically derived beam velocities to an orthogonal system is presented for obtaining 2-D current fields from a single station. The accuracy of the VHF radar-derived radial velocities is examined using a new statistical technique that evaluates the system over the range of measured velocities. The VHF radar velocities showed a bias of 3 to 7 cm/s over the experimental period explainable by the differences in radar penetration and in-situ measurement height. The 2-D current field shows good agreement with the in-situ measurements. Deviations and inaccuracies are well explained by the geometric dilution analysis. ?? 2011 IEEE.

  3. VHF SoOp (Signal of Opportunity) Technology Demonstration for Soil Moisture Measurement Using Microwave Hydraulic Boom Truck Platform

    Science.gov (United States)

    Joseph, Alicia; Deshpande, Manohar; O'Neill, Peggy; Miles, Lynn

    2017-04-01

    A goal of this research is to test deployable VHF antennas for 6U Cubesat platforms to enable validation of root zone soil moisture (RZSM) estimation algorithms for signal of opportunity (SoOp) remote sensing over the 240-270 MHz frequency band. The proposed work provides a strong foundation for establishing a technology development path for maturing a global direct surface soil moisture (SM) and RZSM measurement system over a variety of land covers. Knowledge of RZSM up to a depth of 1 meter and surface SM up to a depth of 0.05 meter on a global scale, at a spatial resolution of 1-10 km through moderate-to-heavy vegetation, is critical to understanding global water resources and the vertical moisture gradient in the Earth's surface layer which controls moisture interactions between the soil, vegetation, and atmosphere. Current observations of surface SM from space by L-band radiometers (1.4 GHz) and radars (1.26 GHz) are limited to measurements of surface SM up to a depth of 0.05 meter through moderate amounts of vegetation. This limitation is mainly due to the inability of L-band signals to penetrate through dense vegetation and deep into the soil column. Satellite observations of the surface moisture conditions are coupled to sophisticated models which extrapolate the surface SM into the root zone, thus providing an indirect estimate rather than a direct measurement of RZSM. To overcome this limitation, low-frequency airborne radars operating at 435 MHz and 118 MHz have been investigated, since these lower frequencies should penetrate denser vegetation and respond to conditions deeper in the soil. This presentation describes a new and less expensive technique for SM as well as RZSM direct measurement using Signal of Opportunity transmitters. Being less expensive and needing only passive simple RF receiver, the SoOp concept has the potential for being used for space borne applications, thus providing global SM and RZSM measurements. This study will describe

  4. VHF and L-band scintillation characteristics over an Indian low latitude station, Waltair (17.7° N, 83.3° E

    Directory of Open Access Journals (Sweden)

    P. V. S. Rama Rao

    2005-10-01

    Full Text Available Characteristics of simultaneous VHF (244 MHz and L-band (1.5 GHz scintillations recorded at a low-latitude station, Waltair (17.7° N, 83.3° E, during the low sunspot activity year of March 2004 to March 2005, suggest that the occurrence of scintillations is mainly due to two types, namely the Plasma Bubble Induced (PBI, which maximizes during the post sunset hours of winter and equinoctial months, and the Bottom Side Sinusoidal (BSS type, which maximizes during the post-midnight hours of the summer solstice months. A detailed study on the spectral characteristics of the scintillations at both the frequencies show that the post-sunset scintillations are strong with fast fading (≈40 fad/min and are multiple in nature in scattering, giving rise to steep spectral slopes, whereas the post-midnight scintillations, which occur mostly on the VHF signal with low fading rate (≈4 fad/min, are of the BSS type, often showing typical Fresnel oscillations with reduced roll off spectral slopes, indicating that the type of irregularity resembles a thin screen structure giving rise to weak scattering. Using the onset times of several similar scintillation patches across the two satellite (FLEETSAT 73° E, INMARSAT 65° E ray paths (sub-ionospheric points are separated by 82 km, the East ward movement of the irregularity patches is found to vary from 150 to 250 m/s during the post sunset hours and decrease slowly during the post midnight hours. Further, the east-west extent of the PBI type of irregularities is found to vary from 100 to 500 km, while that of the BSS type extend up to a few thousand kilometers. Keywords. Ionosphere (Ionospheric irregularities; Auroral ionosphere; Electric fields and currents

  5. VHF SoOp (Signal of Opportunity) Technology Demonstration for Soil Moisture Measurement Using Microwave Hydraulic Boom Truck Platform

    Science.gov (United States)

    Joseph, A. T.; Deshpande, M.; O'Neill, P. E.; Miles, L.

    2017-01-01

    A goal of this research is to test deployable VHF antennas for 6U Cubesat platforms to enable validation of root zone soil moisture (RZSM) estimation algorithms for signal of opportunity (SoOp) remote sensing over the 240-270 MHz frequency band. The proposed work provides a strong foundation for establishing a technology development path for maturing a global direct surface soil moisture (SM) and RZSM measurement system over a variety of land covers. Knowledge of RZSM up to a depth of 1 meter and surface SM up to a depth of 0.05 meter on a global scale, at a spatial resolution of 1-10 km through moderate-to-heavy vegetation, is critical to understanding global water resources and the vertical moisture gradient in the Earths surface layer which controls moisture interactions between the soil, vegetation, and atmosphere. Current observations of surface SM from space by L-band radiometers (1.4 GHz) and radars (1.26 GHz) are limited to measurements of surface SM up to a depth of 0.05 meter through moderate amounts of vegetation. This limitation is mainly due to the inability of L-band signals to penetrate through dense vegetation and deep into the soil column. Satellite observations of the surface moisture conditions are coupled to sophisticated models which extrapolate the surface SM into the root zone, thus providing an indirect estimate rather than a direct measurement of RZSM. To overcome this limitation, low-frequency airborne radars operating at 435 MHz and 118 MHz have been investigated, since these lower frequencies should penetrate denser vegetation and respond to conditions deeper in the soil.

  6. Microwave energy transmission test toward the SPS using the space station

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, N.; Matsumoto, H.; Miyatake, S.; Kimura, I.; Nagatomo, M.

    1986-12-01

    An outline of a project METT (Microwave Energy Transmission Test) using the Space Station is described. The objectives of the METT are to develop and test the technology of microwave energy transmission for the future Solar Power Satellite (SPS), and to estimate the environmental effects of the high power microwaves on the ionosphere and the atmosphere. Energy generated with solar cells is transmitted from a transmitting antenna on the bus platform near the Space Station to a rectenna on the sub-satellite or the ground station in order to test the total efficiency and the functions of the developed system of the energy transmission. Plasma similar to that in the D and E layers in the ionosphere is produced in a large balloon opened on the sub-satellite in order to investigate possible interactions between the SPS microwave and the ionospheric plasma and to determine the maximum power density of the microwave beam which passes through the ionosphere.

  7. Microwave energy transmission test toward the SPS using the Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, N.; Matsumoto, H.; Miyatake, S.; Kimura, I.; Nagatomo, M.

    1985-01-01

    An outline of a project METT (Microwave Energy Transmission Test) using the Space Station is described. The objectives of the METT are to develop and test the technology of microwave energy transmission for the future Solar Power Satellite (SPS), and to estimate the environmental effects of the high power microwaves on the ionosphere and the atmosphere. Energy generated with solar cells is transmitted from a transmitting antenna on the bus platform near the Space Station to a rectenna on the sub-satellite or the ground station in order to test the total efficiency and the functions of the development system of the energy transmission. Plasma similar to that in the D and E layers in the ionosphere is produced in a large balloon opened on the sub-satellite in order to investigate possible interactions between the SPS microwave and the ionospheric plasma and to determine the maximum power density of the microwave beam which passes through the ionosphere. 9 references.

  8. The Concept of Building a Radar Station Based on the Microwave Photonics Components

    Directory of Open Access Journals (Sweden)

    A. V. Shumov

    2016-01-01

    Full Text Available The microwave photonics is one of the most promising directions in modern radar engineering. Application of microwave photonics components provides a significant improvement in certain characteristics of radar:- dramatically improving informational content and resolution range of radar;- increasing range of target detection;- high noise immunity;- performance stability under changing climate, primarily, temperature conditions;- lessened weight and size parameters of antenna systems;- lessened cost.The article reviews and analyses modern domestic and foreign publications concerning the application of microwave photonics components in radar engineering.There is a lack of the deep-laid circuit solution of radar based on the active phased array antenna (APAA realizing all the major advantages of using microwave photonics components despite the fairly large number of articles concerned with hardware components of microwave photonics, circuit design, and creating the separate units of radio-photon radar.The article presents the elaboration results of a radar station (RS structure based on the components of microwave photonics, shows the selection and justifies the specific technical solutions for all the key units making the system as a whole: a device to form a sound signal, an optical transceiver unit, an optical digital receiver, and the fiber optic lines.The paper makes selection and justification of the specific hardware components (both domestic and foreign currently available at the world market to create the system thereby showing that now in engineering point of view it is already possible to implement a radar based on the components of microwave photonics.The calculation of tactical and technical characteristics of radar type “Voronezh-M” using microwave photonics components has shown a dramatically increased resolution and detection range, as well as, at least, 2 times reduced weight and size parameters of the product.

  9. Dicty_cDB: VHF264 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF264 (Link to dictyBase) - - - Contig-U16260-1 VHF264P (Link to Original site) VHF...264F 606 VHF264Z 693 VHF264P 1279 - - Show VHF264 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF2-C/VHF264Q.Seq.d/ Representative seq. ID VHF...264P (Link to Original site) Representative DNA sequence >VHF264 (VHF264Q) /CSM/VH/VHF2-C/VHF...DRRKNIRNMSVIAHVDHGKTTLSDSLIQRAGIIADKV SGDMRYMSCRADEQERGITIKSSSVSLHFEMPKEDKLPAGCTS

  10. Dicty_cDB: VHF181 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF181 (Link to dictyBase) - - - Contig-U16260-1 VHF181P (Link to Original site) VHF...181F 610 VHF181Z 416 VHF181P 1006 - - Show VHF181 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF1-D/VHF181Q.Seq.d/ Representative seq. ID VHF...181P (Link to Original site) Representative DNA sequence >VHF181 (VHF181Q) /CSM/VH/VHF1-D/VHF...VKYKMVNFTIDQIRAIMDRRENIRNMSVIAHVDHGKTTLSDSLIQRAGIIADKVSG DMRYMSCRADEQERGITIKSSSVSLHF

  11. Dicty_cDB: VHF777 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF777 (Link to dictyBase) - - - Contig-U16283-1 VHF777P (Link to Original site) VHF...777F 474 VHF777Z 669 VHF777P 1123 - - Show VHF777 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF7-D/VHF777Q.Seq.d/ Representative seq. ID VHF...777P (Link to Original site) Representative DNA sequence >VHF777 (VHF777Q) /CSM/VH/VHF7-D/VHF...PNIIGVEHYKVATDVQKILXRI*itsryychfryg*fi *rpksncipcs*dstflittirscprxhqygr*ir*tlrlyq

  12. Dicty_cDB: VHF354 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF354 (Link to dictyBase) - - - Contig-U16260-1 VHF354P (Link to Original site) VHF...354F 617 VHF354Z 721 VHF354P 1318 - - Show VHF354 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-C/VHF354Q.Seq.d/ Representative seq. ID VHF...354P (Link to Original site) Representative DNA sequence >VHF354 (VHF354Q) /CSM/VH/VHF3-C/VHF...no Acid sequence LSSAKKVKYKMVNFTIDQIRAIMDRRENIRNMSVIAHVDHGKTTLSDSLIQRAGIIADKV SGD

  13. Dicty_cDB: VHF590 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF590 (Link to dictyBase) - - - Contig-U16306-1 VHF590P (Link to Original site) VHF...590F 115 VHF590Z 603 VHF590P 698 - - Show VHF590 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF5-D/VHF590Q.Seq.d/ Representative seq. ID VHF...590P (Link to Original site) Representative DNA sequence >VHF590 (VHF590Q) /CSM/VH/VHF5-D/VHF5...qlphvlrqlk*sqnfhkkylkkvqeqqq--- ---rwifhrwccfqsthdamyflyqxfgslsw*snlxrpkist*xfyhifghfw*rls*l ss*ipi*lqkwysyv

  14. Dicty_cDB: VHF536 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF536 (Link to dictyBase) - - - Contig-U16531-1 VHF536P (Link to Original site) VHF...536F 255 VHF536Z 685 VHF536P 920 - - Show VHF536 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF5-B/VHF536Q.Seq.d/ Representative seq. ID VHF...536P (Link to Original site) Representative DNA sequence >VHF536 (VHF536Q) /CSM/VH/VHF5-B/VHF5...ti*mlhliskvmtvh*mslslfyggyfl*lsi*llwnysig qvvvcliksikxerllkstmt--- ---*erlcl*ilxlvsichf

  15. Dicty_cDB: VHF730 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF730 (Link to dictyBase) - - - Contig-U15767-1 VHF730P (Link to Original site) VHF...730F 569 VHF730Z 718 VHF730P 1267 - - Show VHF730 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF7-B/VHF730Q.Seq.d/ Representative seq. ID VHF...730P (Link to Original site) Representative DNA sequence >VHF730 (VHF730Q) /CSM/VH/VHF7-B/VHF...QEKRIPVLNSMDANDSINKKA RISWPDGFKYFFVDNQAGDSESAKSGKNLPIQRDIELNWNGEAYEYSNSNYFPINGQXFN DVSYPV--- ---lhvvvvkxvhtlpvnvnqivhf

  16. Dicty_cDB: VHF649 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF649 (Link to dictyBase) - - - Contig-U11031-1 VHF649P (Link to Original site) VHF...649F 562 VHF649Z 671 VHF649P 1213 - - Show VHF649 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF6-C/VHF649Q.Seq.d/ Representative seq. ID VHF...649P (Link to Original site) Representative DNA sequence >VHF649 (VHF649Q) /CSM/VH/VHF6-C/VHF...PNTPPTIKIELPSQSILKPSGQLKK*x* Translated Amino Acid sequence (All Frames) Frame A: i*qlvchlsivlfhhqviyphvlklekhf

  17. Dicty_cDB: VHF527 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF527 (Link to dictyBase) - - - Contig-U16260-1 VHF527P (Link to Original site) VHF...527F 571 VHF527Z 456 VHF527P 1007 - - Show VHF527 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF5-B/VHF527Q.Seq.d/ Representative seq. ID VHF...527P (Link to Original site) Representative DNA sequence >VHF527 (VHF527Q) /CSM/VH/VHF5-B/VHF...AKKVKYKMVNFTIDQIRAIMDRRENIRNMSVIAHVDHGKTTLSDSLIQRAGIIADKV SGDMRYMSCRADEQXRGITIKSSSVSLHF

  18. Dicty_cDB: VHF294 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF294 (Link to dictyBase) - - - Contig-U16441-1 VHF294P (Link to Original site) VHF...294F 573 VHF294Z 215 VHF294P 768 - - Show VHF294 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF2-D/VHF294Q.Seq.d/ Representative seq. ID VHF...294P (Link to Original site) Representative DNA sequence >VHF294 (VHF294Q) /CSM/VH/VHF2-D/VHF2...ssfst*scisfttfry*gfsdctfr*fhfn**RFWFNMEQCII QWVMFYS--- ---DCHVSIKKFFKWWQRLDRWCCXXXSCXXXSWWFWFPTFLRIQISNXXY*k

  19. Dicty_cDB: VHF690 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF690 (Link to dictyBase) - - - Contig-U11064-1 VHF690P (Link to Original site) VHF...690F 199 VHF690Z 419 VHF690P 598 - - Show VHF690 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF6-D/VHF690Q.Seq.d/ Representative seq. ID VHF...690P (Link to Original site) Representative DNA sequence >VHF690 (VHF690Q) /CSM/VH/VHF6-D/VHF6...vllksqsknqyl*hlikslidfinif*hgmhqiyhqrkkn*nq *k--- ---rrwfpr*rernhhfqlc*sts*rgcryw

  20. Dicty_cDB: VHF273 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF273 (Link to dictyBase) - - - Contig-U11514-1 VHF273P (Link to Original site) VHF...273F 644 VHF273Z 678 VHF273P 1302 - - Show VHF273 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF2-D/VHF273Q.Seq.d/ Representative seq. ID VHF...273P (Link to Original site) Representative DNA sequence >VHF273 (VHF273Q) /CSM/VH/VHF2-D/VHF...ctr*ccnvkdwchyssrl*syrs*ts*nrsifidr*iftsh*kdw**s llwfsnetr*skmcchcnwckhflwscckfstrnrrtwssssys*kywslly*fhrhlg

  1. Dicty_cDB: VHF243 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF243 (Link to dictyBase) - - - Contig-U16423-1 VHF243P (Link to Original site) VHF...243F 580 VHF243Z 334 VHF243P 894 - - Show VHF243 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF2-B/VHF243Q.Seq.d/ Representative seq. ID VHF...243P (Link to Original site) Representative DNA sequence >VHF243 (VHF243Q) /CSM/VH/VHF2-B/VHF2...AATCNAGATATTCCAGATTGGTTTGAAAAGATGG TACA sequence update 2002.10.25 Translated Amino Acid sequence ifihadkff*RISHF

  2. Dicty_cDB: VHF134 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF134 (Link to dictyBase) - - - Contig-U16260-1 VHF134P (Link to Original site) VHF...134F 533 VHF134Z 404 VHF134P 917 - - Show VHF134 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF1-B/VHF134Q.Seq.d/ Representative seq. ID VHF...134P (Link to Original site) Representative DNA sequence >VHF134 (VHF134Q) /CSM/VH/VHF1-B/VHF1...cid sequence LSSAKKVKYKMVNFTIDQIRAIMDRRENIRNMSVIAHVDHGKTTLSDSLIQRAGIIADKV SGDMRYMSCRADEQERGITIKSSSVSLHFEMPKE

  3. Dicty_cDB: VHF892 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF892 (Link to dictyBase) - - - Contig-U16260-1 VHF892P (Link to Original site) VHF...892F 140 VHF892Z 417 VHF892P 537 - - Show VHF892 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF8-D/VHF892Q.Seq.d/ Representative seq. ID VHF...892P (Link to Original site) Representative DNA sequence >VHF892 (VHF892Q) /CSM/VH/VHF8-D/VHF8... Translated Amino Acid sequence TIKSSSVSLHFEMPXEDKLPAGCTSHEFLINLIDSPSHVDFS--- ---ELTASPNILEPIYLVEITAPENAIGGI

  4. Dicty_cDB: VHF479 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF479 (Link to dictyBase) - - - Contig-U11426-1 VHF479P (Link to Original site) VHF...479F 629 VHF479Z 691 VHF479P 1300 - - Show VHF479 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF4-D/VHF479Q.Seq.d/ Representative seq. ID VHF...479P (Link to Original site) Representative DNA sequence >VHF479 (VHF479Q) /CSM/VH/VHF4-D/VHF...EKNPQEWRWSGGFFVDSISDYVVKSRNTERPDHDSLLF HVNIKEKQGTHFIRIPLSSKESPPYIIQNDTQFKISFFQRDSPENIDYIEPKEKLCYGWD EPSAEYVL

  5. Dicty_cDB: VHF754 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF754 (Link to dictyBase) - - - Contig-U16531-1 VHF754P (Link to Original site) VHF...754F 526 VHF754Z 624 VHF754P 1130 - - Show VHF754 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF7-C/VHF754Q.Seq.d/ Representative seq. ID VHF...754P (Link to Original site) Representative DNA sequence >VHF754 (VHF754Q) /CSM/VH/VHF7-C/VHF...ixnkmqwlkmlqvk*killk*ekvvslgiiftipf--- ---flvsichfnchc*itfccsrwnnlxllxfldsryllqw*

  6. Dicty_cDB: VHF461 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF461 (Link to dictyBase) - - - Contig-U11551-1 VHF461P (Link to Original site) VHF...461F 646 VHF461Z 261 VHF461P 887 - - Show VHF461 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF4-C/VHF461Q.Seq.d/ Representative seq. ID VHF...461P (Link to Original site) Representative DNA sequence >VHF461 (VHF461Q) /CSM/VH/VHF4-C/VHF4...TTAAATTATTAAAAATAGTAAATAAAAAAAA sequence update 2002.10.25 Translated Amino Acid sequence fyfifenfkthfhiiffl

  7. Dicty_cDB: VHF781 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF781 (Link to dictyBase) - - - Contig-U16440-1 VHF781P (Link to Original site) VHF...781F 452 VHF781Z 680 VHF781P 1112 - - Show VHF781 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF7-D/VHF781Q.Seq.d/ Representative seq. ID VHF...781P (Link to Original site) Representative DNA sequence >VHF781 (VHF781Q) /CSM/VH/VHF7-D/VHF...vlkmmmlkf*xixftr*r Frame C: glldinkleeiik*rfhlfylfl*rlllayhfhkilfqlisktaligsnfnhyiqikmim y*l*iqdqrmf*kdqqmvv

  8. Dicty_cDB: VHF435 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF435 (Link to dictyBase) - - - Contig-U16260-1 VHF435P (Link to Original site) VHF...435F 616 VHF435Z 703 VHF435P 1299 - - Show VHF435 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF4-B/VHF435Q.Seq.d/ Representative seq. ID VHF...435P (Link to Original site) Representative DNA sequence >VHF435 (VHF435Q) /CSM/VH/VHF4-B/VHF...AKKVKYKMVNFTIDQIRAIMDRRENIRNMSVIAHVDHGKTTLSDSLIQRAGIIADKV SGDMRYMSCRADEQERGITIKSSSVSLHF

  9. Dicty_cDB: VHF553 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF553 (Link to dictyBase) - - - Contig-U16433-1 VHF553P (Link to Original site) VHF...553F 122 VHF553Z 533 VHF553P 635 - - Show VHF553 Library VH (Link to library) Clone ID VHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF5-C/VHF553Q.Seq.d/ Representative seq. ID VHF...553P (Link to Original site) Representative DNA sequence >VHF553 (VHF553Q) /CSM/VH/VHF5-C/VHF5...ed Amino Acid sequence syhfylfiy*IIIYLLNYYLLSCVNYLPINFNILYIY--- ---YVINLTLDGDNVNGFPKTVTVKPAPSXEQXYAEGEGLVKVF

  10. Dicty_cDB: VHF163 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF163 (Link to dictyBase) - - - Contig-U11129-1 VHF163P (Link to Original site) VHF1...63F 611 VHF163Z 654 VHF163P 1245 - - Show VHF163 Library VH (Link to library) Clone ID VHF1...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF1-C/VHF163Q.Seq.d/ Representative seq. ID VHF1...63P (Link to Original site) Representative DNA sequence >VHF163 (VHF163Q) /CSM/VH/VHF1-C/VHF1...nt alignments: (bits) Value VHF163 (VHF163Q) /CSM/VH/VHF1-C/VHF163Q.Seq.d/ 2357 0.0 VHM584 (VHM584Q) /CSM/VH

  11. Dicty_cDB: VHF444 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available (Link to library) VHF444 (Link to dictyBase) - G20601 DDB0204337 Contig-U12392-1 VHF444P (Link to Original...site) VHF444F 579 VHF444Z 213 VHF444P 772 - - Show VHF444 Library VH (Link to library) Clone ID VHF444 (Link...tsukuba.ac.jp/CSM/VH/VHF4-B/VHF444Q.Seq.d/ Representative seq. ID VHF444P (Link to Original site) Representative...Representative DNA sequence >VHF444 (VHF444Q) /CSM/VH/VHF4-B/VHF444Q.Seq.d/ CAAAAGAAATAAATAATTATGCCATCA...significant alignments: (bits) Value VHF444 (VHF444Q) /CSM/VH/VHF4-B/VHF444Q.Seq.d/ 1479 0.0 VHA836 (VHA836Q)

  12. Dicty_cDB: VHF338 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF338 (Link to dictyBase) - - - Contig-U14303-1 VHF338P (Link to Original site) VHF3...38F 208 VHF338Z 685 VHF338P 873 - - Show VHF338 Library VH (Link to library) Clone ID VHF3... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-B/VHF338Q.Seq.d/ Representative seq. ID VHF3...38P (Link to Original site) Representative DNA sequence >VHF338 (VHF338Q) /CSM/VH/VHF3-B/VHF3...significant alignments: (bits) Value VHF338 (VHF338Q) /CSM/VH/VHF3-B/VHF338Q.Seq.d/ 1296 0.0 VHK267 (VHK267Q

  13. Dicty_cDB: VHF394 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF394 (Link to dictyBase) - - - Contig-U16260-1 VHF394P (Link to Original site) VHF3...94F 563 VHF394Z 417 VHF394P 960 - - Show VHF394 Library VH (Link to library) Clone ID VHF3... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-D/VHF394Q.Seq.d/ Representative seq. ID VHF3...94P (Link to Original site) Representative DNA sequence >VHF394 (VHF394Q) /CSM/VH/VHF3-D/VHF3...nt alignments: (bits) Value VHF394 (VHF394Q) /CSM/VH/VHF3-D/VHF394Q.Seq.d/ 1776 0

  14. Dicty_cDB: VHF340 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF340 (Link to dictyBase) - - - Contig-U11939-1 VHF340P (Link to Original site) VHF3...40F 113 VHF340Z 506 VHF340P 599 - - Show VHF340 Library VH (Link to library) Clone ID VHF3... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-B/VHF340Q.Seq.d/ Representative seq. ID VHF3...40P (Link to Original site) Representative DNA sequence >VHF340 (VHF340Q) /CSM/VH/VHF3-B/VHF3...Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHF340 (VHF340Q) /CSM/VH/VHF3-B/VHF3

  15. Dicty_cDB: VHF329 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF329 (Link to dictyBase) - - - Contig-U16260-1 VHF329P (Link to Original site) VHF3...29F 618 VHF329Z 633 VHF329P 1231 - - Show VHF329 Library VH (Link to library) Clone ID VHF3...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-B/VHF329Q.Seq.d/ Representative seq. ID VHF3...29P (Link to Original site) Representative DNA sequence >VHF329 (VHF329Q) /CSM/VH/VHF3-B/VHF3...s CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHF329 (VHF329Q) /CSM/VH/VHF3

  16. Dicty_cDB: VHF187 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF187 (Link to dictyBase) - - - Contig-U16363-1 VHF187P (Link to Original site) VHF1...87F 549 VHF187Z 707 VHF187P 1236 - - Show VHF187 Library VH (Link to library) Clone ID VHF1...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF1-D/VHF187Q.Seq.d/ Representative seq. ID VHF1...87P (Link to Original site) Representative DNA sequence >VHF187 (VHF187Q) /CSM/VH/VHF1-D/VHF1...* Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHF187 (VHF1

  17. Dicty_cDB: VHF368 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF368 (Link to dictyBase) - - - Contig-U12673-1 VHF368P (Link to Original site) VHF3...68F 597 VHF368Z 746 VHF368P 1323 - - Show VHF368 Library VH (Link to library) Clone ID VHF3...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-C/VHF368Q.Seq.d/ Representative seq. ID VHF3...68P (Link to Original site) Representative DNA sequence >VHF368 (VHF368Q) /CSM/VH/VHF3-C/VHF3...ikfpknkii*nki k*nkiky Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHF368 (VHF3

  18. Dicty_cDB: VHF348 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF348 (Link to dictyBase) - - - Contig-U13926-1 VHF348P (Link to Original site) VHF3...48F 539 VHF348Z 473 VHF348P 992 - - Show VHF348 Library VH (Link to library) Clone ID VHF3... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-B/VHF348Q.Seq.d/ Representative seq. ID VHF3...48P (Link to Original site) Representative DNA sequence >VHF348 (VHF348Q) /CSM/VH/VHF3-B/VHF3...ksxvlmliltck Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHF3

  19. Dicty_cDB: VHF312 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF312 (Link to dictyBase) - - - Contig-U15897-1 VHF312P (Link to Original site) VHF3...12F 543 VHF312Z 483 VHF312P 1006 - - Show VHF312 Library VH (Link to library) Clone ID VHF3...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-A/VHF312Q.Seq.d/ Representative seq. ID VHF3...12P (Link to Original site) Representative DNA sequence >VHF312 (VHF312Q) /CSM/VH/VHF3-A/VHF3... 4.0 %: extracellular, including cell wall 4.0 %: plasma membrane 4.0 %: peroxisomal >> prediction for VHF31

  20. Dicty_cDB: VHF375 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF375 (Link to dictyBase) - - - Contig-U16260-1 VHF375P (Link to Original site) VHF3...75F 432 VHF375Z 670 VHF375P 1082 - - Show VHF375 Library VH (Link to library) Clone ID VHF3...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-D/VHF375Q.Seq.d/ Representative seq. ID VHF3...75P (Link to Original site) Representative DNA sequence >VHF375 (VHF375Q) /CSM/VH/VHF3-D/VHF3...pperekv*pqksqiltnstknskqfkshxsfqr*xsnlkk Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHF3

  1. Dicty_cDB: VHF190 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available F0-ATPase putative regulatory protein IF1 (if1) mRNA, complete cds; nuclear gene for mitochondrial produc...VH (Link to library) VHF190 (Link to dictyBase) - - - Contig-U12594-1 - (Link to Original site) VHF1...90F 581 - - - - - - Show VHF190 Library VH (Link to library) Clone ID VHF190 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF1-D/VHF190Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF190 (VHF190Q) /CSM/VH/VHF1-D/VHF190Q.Seq.d/ ATTTTTCATTTTAAAAA

  2. Dicty_cDB: VHF331 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF331 (Link to dictyBase) - - - - - (Link to Original site) VHF3...31F 609 - - - - - - Show VHF331 Library VH (Link to library) Clone ID VHF331 (Link to dictyBase) Atlas ID... - NBRP ID - dictyBase ID - Link to Contig - Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-B/VHF3...31Q.Seq.d/ Representative seq. ID - (Link to Original site) Representative DNA sequence >VHF3...31 (VHF331Q) /CSM/VH/VHF3-B/VHF331Q.Seq.d/ AACTCTCGAGTGCAAAAAAAGTAAAGTACAAAATGGTTAATTTCA

  3. Dicty_cDB: VHF709 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF709 (Link to dictyBase) - - - Contig-U15897-1 - (Link to Original site) - - VHF...709Z 602 - - - - Show VHF709 Library VH (Link to library) Clone ID VHF709 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF7-A/VHF709Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF709 (VHF709Q) /CSM/VH/VHF7-A/VHF709Q.Seq.d/ XXXXXXXXXXCGTCCAA...vestir Frame B: ---sknfttrsrlqlccsfnglxpr**rw*tnrqhyhg*cksiwsssfnlsryyw*yrcs ilpqiq*kwchhsnlpiw*wsflyhf

  4. Dicty_cDB: VHF236 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF236 (Link to dictyBase) - - - Contig-U14303-1 - (Link to Original site) - - VHF...236Z 611 - - - - Show VHF236 Library VH (Link to library) Clone ID VHF236 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF2-B/VHF236Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF236 (VHF236Q) /CSM/VH/VHF2-B/VHF236Q.Seq.d/ XXXXXXXXXXTGCCATT...VQKISQELKHLT*tfvsylvlk Frame B: ---plvicc*ninvlhfveilsxhglay*xhcfplvlv*fqilsrmiqs

  5. Dicty_cDB: VHF140 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF140 (Link to dictyBase) - - - Contig-U15309-1 - (Link to Original site) - - VHF...140Z 518 - - - - Show VHF140 Library VH (Link to library) Clone ID VHF140 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF1-B/VHF140Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF140 (VHF140Q) /CSM/VH/VHF1-B/VHF140Q.Seq.d/ XXXXXXXXXXCCGATAA...EDYINMQIKQLENSENSQELIQKLNEHLSEYKASVEEIKHNVQNN Frame C: ---iixvtlmlflqngilhfigviil

  6. Dicty_cDB: VHF507 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF507 (Link to dictyBase) - - - Contig-U11594-1 - (Link to Original site) - - VHF...507Z 541 - - - - Show VHF507 Library VH (Link to library) Clone ID VHF507 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF5-A/VHF507Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF507 (VHF507Q) /CSM/VH/VHF5-A/VHF507Q.Seq.d/ XXXXXXXXXXTACCAAT...nvhsmiwihvglxlvigx*sncfvttsfikst mmvllcstftmllkpsixwivvsmkkyf*clemnxhfw*sviki*knv

  7. Dicty_cDB: VHF321 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF321 (Link to dictyBase) - - - Contig-U16260-1 - (Link to Original site) VHF...321F 617 - - - - - - Show VHF321 Library VH (Link to library) Clone ID VHF321 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF3-A/VHF321Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF321 (VHF321Q) /CSM/VH/VHF3-A/VHF321Q.Seq.d/ AACTCTCGAGTGCAAAA...VIAHVDHGKTTLSDSLIQRAGIIADKV SGDMRYMSCRADEQERGITIKSSSVSLHFEMPKEDKLPAGCTSHEFLINLIDSPGHVDFS SEVTAALRVTDGALVVIDC

  8. Dicty_cDB: VHF866 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF866 (Link to dictyBase) - - - Contig-U16600-1 - (Link to Original site) - - VHF...866Z 388 - - - - Show VHF866 Library VH (Link to library) Clone ID VHF866 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF8-C/VHF866Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF866 (VHF866Q) /CSM/VH/VHF8-C/VHF866Q.Seq.d/ XXXXXXXXXXAAGCAGC...Frame C: ---qhnnifklafptiknftgvpmxfvmtnegdnlgnftvkthfakffstyyscgeaghh yfdsccn*y*qkqgckfhs*h*xkssrr*lcfxqnwfi

  9. Dicty_cDB: VHF155 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF155 (Link to dictyBase) - - - - VHF155P (Link to Original site) VHF155F 587 VHF1...55Z 643 VHF155P 1210 - - Show VHF155 Library VH (Link to library) Clone ID VHF155 (Link... to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig - Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF1...-C/VHF155Q.Seq.d/ Representative seq. ID VHF155P (Link to... Original site) Representative DNA sequence >VHF155 (VHF155Q) /CSM/VH/VHF1-C/VHF155Q.Seq.d/ ATTCTCGATACTGGAA

  10. Dicty_cDB: VHF392 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF392 (Link to dictyBase) - - - - VHF392P (Link to Original site) VHF392F 568 VHF3...92Z 375 VHF392P 923 - - Show VHF392 Library VH (Link to library) Clone ID VHF392 (Link ...to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig - Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3...-D/VHF392Q.Seq.d/ Representative seq. ID VHF392P (Link to ...Original site) Representative DNA sequence >VHF392 (VHF392Q) /CSM/VH/VHF3-D/VHF392Q.Seq.d/ AACTCTCGAGTGCAAAA

  11. Dicty_cDB: VHF366 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF366 (Link to dictyBase) - - - Contig-U12131-1 | Contig-U13633-1 VHF3...66P (Link to Original site) VHF366F 590 VHF366Z 544 VHF366P 1114 - - Show VHF366 Library VH (Link to library) Clone ID VHF3...131-1 | Contig-U13633-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-C/VHF3...66Q.Seq.d/ Representative seq. ID VHF366P (Link to Original site) Representative DNA sequence >VHF366 (VHF3...66Q) /CSM/VH/VHF3-C/VHF366Q.Seq.d/ AATAATTTATTATTATTATTAATAAGTAATAGAAATAAAAGATGGAACCAATTCCAGATA

  12. Dicty_cDB: VHF310 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF310 (Link to dictyBase) - - - Contig-U16260-1 - (Link to Original site) - - VHF3...10Z 625 - - - - Show VHF310 Library VH (Link to library) Clone ID VHF310 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF3-A/VHF310Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF310 (VHF310Q) /CSM/VH/VHF3-A/VHF310Q.Seq.d/ XXXXXXXXXXTCGTCAA...omology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHF310 (VHF310Q) /CSM/VH/VHF3-A/VHF3

  13. Dicty_cDB: VHF315 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF315 (Link to dictyBase) - G20600 DDB0169270 Contig-U12450-1 VHF3...15P (Link to Original site) VHF315F 216 VHF315Z 353 VHF315P 549 - - Show VHF315 Library VH (Link to library) Clone ID VHF3...ontig-U12450-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF3-A/VHF3...15Q.Seq.d/ Representative seq. ID VHF315P (Link to Original site) Representative DNA sequence >VHF315 (VHF315Q) /CSM/VH/VHF3...-A/VHF315Q.Seq.d/ ATTAAAAAACTTCTTACTTGGACACCCCTTTTATATATATAAATAAAAACTTCTAAATAT AAATCCCA

  14. Dicty_cDB: VHF381 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF381 (Link to dictyBase) - - - Contig-U16508-1 - (Link to Original site) - - VHF3...81Z 645 - - - - Show VHF381 Library VH (Link to library) Clone ID VHF381 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHF3-D/VHF381Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHF381 (VHF381Q) /CSM/VH/VHF3-D/VHF381Q.Seq.d/ XXXXXXXXXXCAACCAA...ignments: (bits) Value VHF381 (VHF381Q) /CSM/VH/VHF3-D/VHF381Q.Seq.d/ 1223 0.0 VHP767 (VHP767Q) /CSM/VH/VHP7

  15. Dicty_cDB: VHF210 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF210 (Link to dictyBase) - - - Contig-U12400-1 | Contig-U16431-1 VHF...210P (Link to Original site) VHF210F 613 VHF210Z 636 VHF210P 1229 - - Show VHF210 Library VH (Link to library) Clone ID VHF...400-1 | Contig-U16431-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF2-A/VHF...210Q.Seq.d/ Representative seq. ID VHF210P (Link to Original site) Representative DNA sequence >VHF210 (VHF...210Q) /CSM/VH/VHF2-A/VHF210Q.Seq.d/ AATAAAATGATAAGATCATCAATAAAAAATAAAATAACAACAACAAAAAGTTTATCATGT

  16. Dicty_cDB: VHF575 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF575 (Link to dictyBase) - - - Contig-U15481-1 | Contig-U15981-1 VHF...575P (Link to Original site) VHF575F 586 VHF575Z 397 VHF575P 963 - - Show VHF575 Library VH (Link to library) Clone ID VHF...81-1 | Contig-U15981-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF5-D/VHF...575Q.Seq.d/ Representative seq. ID VHF575P (Link to Original site) Representative DNA sequence >VHF575 (VHF...575Q) /CSM/VH/VHF5-D/VHF575Q.Seq.d/ ATAATAATACAAAGAAGAAATGAAAAATATAAATAATAAAATTTTAAAGATTTTTATTCT

  17. Dicty_cDB: VHF296 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF296 (Link to dictyBase) - G23392 DDB0187414 Contig-U12449-1 VHF...296P (Link to Original site) VHF296F 241 VHF296Z 482 VHF296P 703 - - Show VHF296 Library VH (Link to library) Clone ID VHF...ontig-U12449-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF2-D/VHF...296Q.Seq.d/ Representative seq. ID VHF296P (Link to Original site) Representative DNA sequence >VHF296 (VHF296Q) /CSM/VH/VHF...2-D/VHF296Q.Seq.d/ GATTATCAGAAAGATTACATTATGAAATTATACCAGATTGTATTAAAATTATTGAAAGCT CAAAACAA

  18. Dicty_cDB: VHF436 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF436 (Link to dictyBase) - - - - VHF436P (Link to Original site) VHF436F 618 VHF...436Z 699 VHF436P 1297 - - Show VHF436 Library VH (Link to library) Clone ID VHF436 (Link... to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig - Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF...4-B/VHF436Q.Seq.d/ Representative seq. ID VHF436P (Link to... Original site) Representative DNA sequence >VHF436 (VHF436Q) /CSM/VH/VHF4-B/VHF436Q.Seq.d/ AACTCTCGAGTGCAAA

  19. Dicty_cDB: VHF158 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF158 (Link to dictyBase) - - - - VHF158P (Link to Original site) VHF158F 608 VHF...158Z 693 VHF158P 1281 - - Show VHF158 Library VH (Link to library) Clone ID VHF158 (Link... to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig - Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF...1-C/VHF158Q.Seq.d/ Representative seq. ID VHF158P (Link to... Original site) Representative DNA sequence >VHF158 (VHF158Q) /CSM/VH/VHF1-C/VHF158Q.Seq.d/ AACTCTCGAGTGCAAA

  20. Dicty_cDB: VHF847 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF847 (Link to dictyBase) - - - Contig-U15351-1 | Contig-U16514-1 VHF...847P (Link to Original site) VHF847F 478 VHF847Z 709 VHF847P 1167 - - Show VHF847 Library VH (Link to library) Clone ID VHF...351-1 | Contig-U16514-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF8-B/VHF...847Q.Seq.d/ Representative seq. ID VHF847P (Link to Original site) Representative DNA sequence >VHF847 (VHF...847Q) /CSM/VH/VHF8-B/VHF847Q.Seq.d/ TATGATGTTCCACTTATAATTCAAACGGTTGCCAATAATAAATCAACAAAACTCANTCTT

  1. Dicty_cDB: VHF272 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF272 (Link to dictyBase) - - - Contig-U15754-1 VHF272P (Link to Original site) VHF...272F 515 VHF272Z 603 VHF272P 1098 - - Show VHF272 Library VH (Link to library) Clone ID VHF...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHF2-C/VHF272Q.Seq.d/ Representative seq. ID VHF...272P (Link to Original site) Representative DNA sequence >VHF272 (VHF272Q) /CSM/VH/VHF2-C/VHF...id sequence (All Frames) Frame A: ixfssq**wnkkd*mihy*eiligrigvpm*vidngqlfvkimvvnhgptfhtimldhvh idgqrivlvdfvidfkifv*v*hf

  2. Design and Development of VHF Antennas for Space Borne Signal of Opportunity Receivers for Cubesat Platforms

    Science.gov (United States)

    Deshpande, Manohar; Piepmeier, Jeffrey

    2015-01-01

    Design and Development of VHF Antennas for Space Borne Signal of Opportunity Receivers for Cubesat Platforms. Space borne microwave remote sensors at VHF/UHF frequencies are important instruments to observe reflective properties of land surfaces through thick and heavy forestation on a global scale. One of the most cost effective ways of measuring land reflectivity at VHF/UHF frequencies is to use signals transmitted by existing communication satellites (operating at VHF/UHF band) as a signal of opportunity (SoOp) signal and passive receivers integrated with airborne/space borne platforms operating in the Low Earth Orbit (LEO). One of the critical components of the passive receiver is two antennas (one to receive only direct signal and other to receive only reflected signal) which need to have ideally high (>30dB) isolation. However, because of small size of host platforms and broad beam width of dipole antennas, achieving adequate isolation between two channels is a challenging problem and need to be solved for successful implementation of space borne SoOp technology for remote sensing. In this presentation a novel enabling VHF antenna technology for Cubesat platforms is presented to receive direct as well as reflected signal with needed isolation. The novel scheme also allows enhancing the gain of individual channels by factor of 2 without use of reflecting ground plane

  3. Transmission of microwave beamed-power from an orbiting space station to the ground

    Energy Technology Data Exchange (ETDEWEB)

    Welch, R.M. (Johannes Gutenberg Univ., Mainz, Germany); Davis, J.M.; Cox, S.K.

    1982-01-01

    Transmission efficiencies and surface power densities are calculated from the interaction of a 10 GW microwave beam with rain clouds. Computations are made as a function of (a) frequency (2.45 to 10 GHz); (b) beam nadir angle; (c) raindrop size distribution; and (d) cloud shape. Scattered surface power densities outside of the receiving rectenna do not exceed 10 ..mu..W/cm/sup 2/ for frequencies of 2.45 and 3.3 GHz, even for extremely heavy rainfall rates. At higher frequencies exposure levels outside of the rectenna may reach 100 ..mu..W/cm/sup 2/, or two orders of magnitude less than the US safety standard. From the standpoint of public health and safety, the scattering of microwaves by rain clouds is not a serious problem, with scattered fluxes outside of the rectenna much smaller than sidelobe fluxes. Beam losses due to absorption in rain clouds are significant in some cases, with absorption losses far more important than scattering losses. The amount of scattering increases with increasing microwave frequency, increasing drop size and drop concentration and increasing nadir angle of the beam.

  4. A system for mapping sources of VHF and electric field pulses from in-cloud lightning at KSC

    Science.gov (United States)

    Thomson, Ewen M.; Medelius, Pedro J.

    1991-01-01

    The literature concerning VHF radiation and wideband electric fields from in-cloud lightning is reviewed. VHF location systems give impressive radio images of lightning in clouds with high spatial and temporal resolution. Using systems based on long and short baseline time-or-arrival and interferometry, workers have detected VHF sources that move at speeds of 10(exp 5) to 10(exp 8) m/s. The more slowly moving sources appear to be associated with channel formation but the physical basis for the higher speeds is not clear. In contrast, wideband electric fields are directly related to physical parameters such as current and tortuosity. A long baseline system is described to measure simultaneously VHF radiation and wideband electric fields at five stations at Kennedy Space Center. All signals are detected over remote, isolated ground planes with fiber optics for data transmission. The modification of this system to map rapidly varying dE/dt pulses is discussed.

  5. Design VHF Antennas for Space Borne Receivers for SmallSats

    Science.gov (United States)

    Deshpande, Manohar

    2017-01-01

    Space borne microwave remote sensors at VHF/UHF frequencies are important instruments to observe reflective properties of land surfaces through thick and heavy forestation on a global scale. One of the most cost effective ways of measuring land reflectivity at VHF/UHF frequencies is to use signals transmitted by existing communication satellites (operating at VHF/UHF band) as a signal of opportunity (SoOp) signal and passive receivers integrated with airborne/space borne platforms operating in the Low Earth Orbit (LEO). One of the critical components of the passive receiver is two antennas (one to receive only direct signal and other to receive only reflected signal) which need to have ideally high (>30dB) isolation. However, because of small size of host platforms and broad beam width of dipole antennas, achieving adequate isolation between two channels is a challenging problem and need to be solved for successful implementation of space borne SoOp technology for remote sensing. In this presentation a novel enabling VHF antenna technology for Cubesat platforms is presented to receive direct as well as reflected signal with needed isolation. The novel scheme also allows enhancing the gain of individual channels by factor of 2 without use of reflecting ground plane.

  6. Dicty_cDB: VHF476 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available uences producing significant alignments: (bits) Value VHF476 (VHF476Q) /CSM/VH/VHF4-D/VHF476Q.Seq.d/ 198 2e-...46 own update 2003.10.17 Homology vs DNA Score E Sequences producing significant alignments: (bits) Value...e 2008.10.29 Homology vs Protein Score E Sequences producing significant alignments: (bits) Value (Q54AX5) R

  7. Ionosphere VHF scintillations over Vaddeswaram (Geographic Latitude 16.31°N, Geographic Longitude 80.30°E, Dip 18°N), a latitude Indian station - A case study

    Science.gov (United States)

    Brahmanandam, P. S.; Uma, G.; Pant, T. K.

    2017-10-01

    This research reports the 250 MHz amplitude ionosphere scintillations recorded at Vaddeswaram (Geographic Latitude 16.31°N, Geographic Longitude 80.30°E, Dip 18°N), a low-latitude station in India. Though amplitude scintillations were recorded for four continuous days (05-08 November 2011), the presence of intense and long-duration scintillations on 06 November 2011 instigated us to verify the ionosphere background conditions. This research, therefore, is also used important databases including, diurnal variations of h‧F (virtual height of the F-layer) and the vertical drifts as measured by an advanced digital ionosonde radar located at an Indian equatorial station i.e. Trivandrum (Geographic Latitude 8.5°N, Geographic Longitude 77°E, Dip 0.5°N), equatorial Electrojet (EEJ) ground strength measured using magnetometers and the total electron content (TEC) maps provided by the International GPS Service (IGS) to study the background ionosphere conditions. The interesting observations are higher E × B drifts, the occurrence of long-duration range-type spread F signatures at Trivandrum and, thereafter, intense scintillations over Vaddeswaram. It was found a secondary peak at around 1600 LT in EEJ strength followed by a higher upward drift velocity (more than 60 m/s) with a significant raise of the F region up to 470 km over the magnetic equator on 06 November 2011. The possible physical mechanisms of these important observational results are discussed in the light of available literature.

  8. Extraction of forest stand parameters from CARABAS VHF SAR images

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Fredrik [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Centre for Image Analysis

    1999-10-01

    Methods for extracting stand-wise forest parameters from CARABAS VHF SAR images have been developed and evaluated. CARABAS is a unique airborne synthetic aperture radar (SAR), developed by the Swedish Defence Research Establishment. It differs a lot from ordinary microwave radars by using wavelengths between 3.3 and 15 m, making the image intensity highly correlated to stem volume. Furthermore, by providing its own illumination source, the sensor operates independently of daylight and weather conditions. Empirical regression models have been developed for relating backscattering amplitude to stem volume, stem diameter, and tree height. To make comparison between CARABAS image data and forest parameters effective, a fully automatic geo-coding algorithm was developed. Image texture features have also been investigated. By using the variogram as a discriminating feature, CARABAS images and aerial images were segmented into homogeneous regions. Furthermore, a method for discriminating recently clear felled areas from forested areas, combining information from Almaz-1 SAR images and SPOT panchromatic data has also been developed, serving as a comparison to the main work of this thesis. For forest stands at near-horizontal ground, the results for estimating stem volume, stem diameter, and tree height from CARABAS image data are very satisfactory. The root mean square errors for the estimates are comparable to subjective ground-based inventories for dense forest stands. The methods and algorithms described in this thesis have been developed towards an operational remote sensing tool. Altogether, significant potential for mapping of forest characteristics exists using the CARABAS VHF SAR sensor 57 refs, 14 figs, 7 tabs

  9. 47 CFR 80.911 - VHF transmitter.

    Science.gov (United States)

    2010-10-01

    ... MARITIME SERVICES Compulsory Radiotelephone Installations for Small Passenger Boats § 80.911 VHF..., measured at the power input terminals to the transmitter, and the output power of the transmitter, terminated in a matching artificial load, must be measured at the end of 10 minutes of continuous operation...

  10. The natural oscillations in stratospheric ozone observed by the GROMOS microwave radiometer at the NDACC station Bern

    Directory of Open Access Journals (Sweden)

    L. Moreira

    2016-08-01

    Full Text Available A multilinear parametric regression analysis was performed to assess the seasonal and interannual variations of stratospheric ozone profiles from the GROMOS (GROund-based Millimeter-wave Ozone Spectrometer microwave radiometer at Bern, Switzerland (46.95° N, 7.44° E; 577 m. GROMOS takes part in the Network for the Detection of Atmospheric Composition Change (NDACC. The study covers the stratosphere from 50 to 0.5 hPa (from 21 to 53 km and extends over the period from January 1997 to January 2015. The natural variability was fitted during the regression analysis through the annual and semi-annual oscillations (AO, SAO, the quasi-biennial oscillation (QBO, the El Niño–Southern Oscillation (ENSO and the solar activity cycle. Seasonal ozone variations mainly appear as an annual cycle in the middle and upper stratosphere and a semi-annual cycle in the upper stratosphere. Regarding the interannual variations, they are primarily present in the lower and middle stratosphere. In the lower and middle stratosphere, ozone variations are controlled predominantly by transport processes, due to the long lifetime of ozone, whereas in the upper stratosphere its lifetime is relatively short and ozone is controlled mainly by photochemistry. The present study shows agreement in the observed naturally induced ozone signatures with other studies. Further, we present an overview of the possible causes of the effects observed in stratospheric ozone due to natural oscillations at a northern midlatitude station. For instance regarding the SAO, we find that polar winter stratopause warmings contribute to the strength of this oscillation since these temperature enhancements lead to a reduction in upper stratospheric ozone. We have detected a strong peak amplitude of about 5 % for the solar cycle in lower stratospheric ozone for our 1.5 cycles of solar activity. Though the 11-year ozone oscillation above Bern is in phase with the solar cycle, we suppose

  11. The natural oscillations in stratospheric ozone observed by the GROMOS microwave radiometer at the NDACC station Bern

    Science.gov (United States)

    Moreira, Lorena; Hocke, Klemens; Navas-Guzmán, Francisco; Eckert, Ellen; von Clarmann, Thomas; Kämpfer, Niklaus

    2016-08-01

    A multilinear parametric regression analysis was performed to assess the seasonal and interannual variations of stratospheric ozone profiles from the GROMOS (GROund-based Millimeter-wave Ozone Spectrometer) microwave radiometer at Bern, Switzerland (46.95° N, 7.44° E; 577 m). GROMOS takes part in the Network for the Detection of Atmospheric Composition Change (NDACC). The study covers the stratosphere from 50 to 0.5 hPa (from 21 to 53 km) and extends over the period from January 1997 to January 2015. The natural variability was fitted during the regression analysis through the annual and semi-annual oscillations (AO, SAO), the quasi-biennial oscillation (QBO), the El Niño-Southern Oscillation (ENSO) and the solar activity cycle. Seasonal ozone variations mainly appear as an annual cycle in the middle and upper stratosphere and a semi-annual cycle in the upper stratosphere. Regarding the interannual variations, they are primarily present in the lower and middle stratosphere. In the lower and middle stratosphere, ozone variations are controlled predominantly by transport processes, due to the long lifetime of ozone, whereas in the upper stratosphere its lifetime is relatively short and ozone is controlled mainly by photochemistry. The present study shows agreement in the observed naturally induced ozone signatures with other studies. Further, we present an overview of the possible causes of the effects observed in stratospheric ozone due to natural oscillations at a northern midlatitude station. For instance regarding the SAO, we find that polar winter stratopause warmings contribute to the strength of this oscillation since these temperature enhancements lead to a reduction in upper stratospheric ozone. We have detected a strong peak amplitude of about 5 % for the solar cycle in lower stratospheric ozone for our 1.5 cycles of solar activity. Though the 11-year ozone oscillation above Bern is in phase with the solar cycle, we suppose that the strong amplitude is

  12. VHF/UHF/microwave LOS terrestrial propagation and system design

    Science.gov (United States)

    Fitzsimons, T. K.

    1986-10-01

    The telecommunication frequency range under discussion is from 30 MHz up to tens of GHz. For military communications this means the use of systems such as Combat Net Radio, Single-Channel Radio Access, Tactical and Fixed Radio Relay, Air-Ground-Air Systems, Common User Information Systems and Tactical Satellite. For civil communications the systems are not dissimilar - mobile radio, fixed radio relay systems, Air Traffic Control, etc. Of course there is a considerable amount of broadcasting and there are military and civil radar systems in these frequency bands. The spectrum range from 30 MHz to about 5 GHz is for the military in particular, prime spectrum; wide bandwidths (hence digital transmission) can be achieved, most propagation mechanisms are relatively stable and most of this part of the spectrum can be used by tactical systems either operating on the move or moving frequently to new sites. In addition to considerations of wanted performance and necessary characteristics such as ECM, the military systems are designed to meet requirements for rapid deployment in an environment which is difficult and unpredictable from the electromagnetic environment, topographic, and meteorological aspects.

  13. Dicty_cDB: VHF729 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ences producing significant alignments: (bits) Value VHF729 (VHF729Q) /CSM/VH/VHF...4-A/CHC421Q.Seq.d/ 139 9e-33 own update 2002.12.27 Homology vs DNA Score E Sequences producing significant alignments: (bits) Value... 139 2e-29 1 dna update 2008.10.31 Homology vs Protein Score E Sequences producing significant alignments: (bits) Value

  14. From ultrafast spectroscopy to bidirectional molecular switches: DHA/VHF

    Science.gov (United States)

    Schmidhammer, U.; De Waele, V.; Buntinx, G.; Riedle, E.

    The photoconversion from dihydroazulene (DHA) to vinylheptafulvene (VHF) is governed by two mechanisms: The ring opening proceeds on the excited energy surface on the picosecond time scale. It is followed by an intemal conversion to the VHF ground state that is accelerated by the presence of a conical intersection in the case of cyclopenta-DHA. This conical intersection hinders the photoinduced back reaction from the final VHF products. However, we successfully photoconverted the cyanophenyl-VHF-cis back to the DHA with a second delayed pulse. This opens the route to the development of bistable DHAs.

  15. Dicty_cDB: VHF823 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available uences producing significant alignments: (bits) Value VHF823 (VHF823Q) /CSM/VH/VH...186Q.Seq.d/ 86 1e-16 own update 2009. 4. 4 Homology vs DNA Score E Sequences producing significant alignments: (bits) Value...-13 1 dna update 2008.10.31 Homology vs Protein Score E Sequences producing significant alignments: (bits) Value

  16. Forming and detection of digital watermarks in the System for Automatic Identification of VHF Transmissions

    Directory of Open Access Journals (Sweden)

    О. В. Шишкін

    2013-07-01

    Full Text Available Forming and detection algorithms for digital watermarks are designed for automatic identification of VHF radiotelephone transmissions in the maritime and aeronautical mobile services. An audible insensitivity and interference resistance of embedded digital data are provided by means of OFDM technology jointly with normalized distortions distribution and data packet detection by the hash-function. Experiments were carried out on the base of ship’s radio station RT-2048 Sailor and USB ADC-DAC module of type Е14-140M L-CARD in the off-line processing regime in Matlab medium

  17. Characterization of aerosol in the atmosphere at Syowa Station by Helium Microwave Induced Plasma Atomic Emission Spectrometry (He-MIP-AES

    Directory of Open Access Journals (Sweden)

    Hitoshi Asano

    2010-12-01

    Full Text Available Atmospheric aerosols at Syowa Station, Antarctica were characterized by helium microwave induced plasma atomic emission spectrometry (He-MIP-AES. The He-MIP-AES can be considered as a suitable method for the characterization of the atmospheric particulate matter since measurements of grain size distribution, elemental analysis for each particle, and chemical state analysis can be available simultaneously. Previous characterization methods such as XRF, PIXE and ICP-MS cannot provide in situ analysis and they need a long time to measure of the distribution of the particle diameter and elemental analysis of each particle. The particle samples in the atmosphere were collected on the membrane lter at Syowa Station in Antarctica. The obtained particles were analyzed by the He-MIP-AES (HORIBA, particle analyzer DP-1000. Elemental analysis, chemical state analysis, and grain diameter distribution analysis were performed. The collected particles mainly contain sea salt (Na, Mg and Ca and soil origin constituents (Si and Fe. The counts of each element increase under blizzard and strong wind condition.

  18. Arctic and Antarctic polar mesosphere summer echoes observed with oblique incidence HF radars: analysis using simultaneous MF and VHF radar data

    Directory of Open Access Journals (Sweden)

    T. Ogawa

    2004-12-01

    Full Text Available Polar mesosphere summer echoes (PMSEs have been well studied using vertical incidence VHF radars at northern high-latitudes. In this paper, two PMSE events detected with the oblique incidence SuperDARN HF radars at Hankasalmi, Finland (62.3° N and Syowa Station, Antarctica (69.0° S, are analyzed, together with simultaneous VHF and medium-frequency (MF radar data. Altitude resolutions of the HF radars in the mesosphere and the lower thermosphere are too poor to know exact PMSE altitudes. However, a comparison of Doppler velocity from the HF radar and neutral wind velocity from the MF radar shows that PMSEs at the HF band appeared at altitudes within 80-90km, which are consistent with those from previous vertical incidence HF-VHF radar results. The HF-VHF PMSE occurrences exhibit a semidiurnal behavior, as observed by other researchers. It is found that in one event, PMSEs occurred when westward semidiurnal winds with large amplitude at 85-88km altitudes attained a maximum. When the HF-VHF PMSEs were observed at distances beyond 180km from MF radar sites, the MF radars detected no appreciable signatures of echo enhancement. Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides

  19. Arctic and Antarctic polar mesosphere summer echoes observed with oblique incidence HF radars: analysis using simultaneous MF and VHF radar data

    Directory of Open Access Journals (Sweden)

    T. Ogawa

    2004-12-01

    Full Text Available Polar mesosphere summer echoes (PMSEs have been well studied using vertical incidence VHF radars at northern high-latitudes. In this paper, two PMSE events detected with the oblique incidence SuperDARN HF radars at Hankasalmi, Finland (62.3° N and Syowa Station, Antarctica (69.0° S, are analyzed, together with simultaneous VHF and medium-frequency (MF radar data. Altitude resolutions of the HF radars in the mesosphere and the lower thermosphere are too poor to know exact PMSE altitudes. However, a comparison of Doppler velocity from the HF radar and neutral wind velocity from the MF radar shows that PMSEs at the HF band appeared at altitudes within 80-90km, which are consistent with those from previous vertical incidence HF-VHF radar results. The HF-VHF PMSE occurrences exhibit a semidiurnal behavior, as observed by other researchers. It is found that in one event, PMSEs occurred when westward semidiurnal winds with large amplitude at 85-88km altitudes attained a maximum. When the HF-VHF PMSEs were observed at distances beyond 180km from MF radar sites, the MF radars detected no appreciable signatures of echo enhancement.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides

  20. Dicty_cDB: VHF145 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHF145 (Link to dictyBase) - - - Contig-U15430-1 VHF145E (Link...) Clone ID VHF145 (Link to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U15430-1 Ori...ology vs DNA Score E Sequences producing significant alignments: (bits) Value N AC116984 |AC116984.2 Dictyos... theta DNA for complete sequence of nucleomorph chromosome 2. 48 2e-07 2 ES451909 | PREDICTED: similar to PI...al 16.0 %: nuclear 8.0 %: vacuolar 8.0 %: endoplasmic reticulum 4.0 %: cytoskeletal >> prediction for VHF145

  1. Broadband Grounded Vertical Antennas for 30-180 MHZ (VHF)

    Science.gov (United States)

    2013-10-18

    antennas are well known for their broadband gain (monocone, bicone ) but are never combined with a monopole. An eccentric combination of broadband...DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Broadband Grounded Vertical Antennas For 30-180 MZH (VHF) 5a. CONTRACT NUMBER 5b...18 Attorney Docket No. 102536 1 of 17 BROADBAND GROUNDED VERTICAL ANTENNAS FOR 30-180 MHZ (VHF) STATEMENT OF GOVERNMENT INTEREST

  2. Anechoic chamber for VHF and UHF bands

    Science.gov (United States)

    Morikawa, Takao; Sugiura, Akira; Harima, Katsushige; Masuzawa, Hiroshi

    1995-06-01

    Built in 1969, the anechoic chamber of CRL has been used to the fullest by researchers in many fields such as EMI, EMC, antenna design, standard of electric field intensity, and type approval testing. In particular, in the early days of space development in Japan, many satellite-born antennas were developed in this anechoic chamber. However, a quarter of a century has passed since its construction and deteriorated performance due to superannuation sometimes caused difficulties in experiments conducted in the chamber. In 1993, CRL constructed a Measuring Facility for Radio Research (MFRR) and the anechoic chamber for VHF-UHF bands was remodeled as one of the sub-facilities of MFRR. The remodeling work included full replacement of the electromagnetic shielding, absorbers and measurement system. Since the remodeled anechoic chamber is being used not only for EMI tests but also for other purposes, a full-anechoic chamber has been adopted. In addition the chamber has been designed for the frequency range between 30 MHz and 10 GHz. After the remodeling work, the performance of the chamber is greatly improved. The average shielding factor is better than 85 dB for all frequency ranges and the unwanted reflection characteristic is -30 dB for frequencies above 1 GHZ. This paper summarizes the remodeling work, and the specifications and performance of the remodeled anechoic chamber.

  3. Ultimate VHF Broadband Interferometer Zen KAWASAKI and Manabu AKITA

    Science.gov (United States)

    Kawasaki, Z.; Akita, M.

    2013-12-01

    Lightning Research Group of Osaka University (LRGOU) has been developing an interferometer for thunderstorm monitoring during these two decades. When LRGOU initiated this project, many related scientists claimed that LRGOU's system was a time of arrival and it must be a sophisticated TOA system. However the key technology of the system were broad band and digital data processing, and it is named the VHF broad band digital interferometer (BDITF), because the phase difference of Fourier components played the very important role. Then the BDITF finally has been realized as a quasi-real time lightning monitoring system, and LRGOU has been operating their BDITFs around Osaka area. Since the BDITF captures the VHF impulses associated with lightning discharges by amplitude triggering, it occasionally misses one of the bi-directional leader progressions because of relatively small amplitude VHF impulses mainly emitted by positive leader tips. All of high density of VHF pulses associated with recoil leaders may not be recorded. Then the ordinary BDITF is able to be accepted as the practical operational system, but from the aspect of science it has been sioriously expected to be improved its performance. To overcome the difficulty New Mexico Institute of Mining and Technology (NMIMT) and LRGOU have started the joint project, and a continuous recording system for digital signals is adopted [M. Stock et al, and M Akita et al,]. The field campaigns have been conducting in New Mexico and in Japan, and successful observations are accomplished. The algorithm to identify individual VHF pulses associated with lightning discharges from back ground noise and/or artificial noise, the dispersion of phase differences for all Fourier components is examined. In case by of small dispersion it is concluded that analyzed VHF pulse has high possibility to be emitted by lightning discharges. This interpretation means that the recorded VHF pulse shape might maintain without deformation during

  4. Reduced growth of soybean seedlings after exposure to weak microwave radiation from GSM 900 mobile phone and base station.

    Science.gov (United States)

    Halgamuge, Malka N; Yak, See Kye; Eberhardt, Jacob L

    2015-02-01

    The aim of this work was to study possible effects of environmental radiation pollution on plants. The association between cellular telephone (short duration, higher amplitude) and base station (long duration, very low amplitude) radiation exposure and the growth rate of soybean (Glycine max) seedlings was investigated. Soybean seedlings, pre-grown for 4 days, were exposed in a gigahertz transverse electromagnetic cell for 2 h to global system for mobile communication (GSM) mobile phone pulsed radiation or continuous wave (CW) radiation at 900 MHz with amplitudes of 5.7 and 41 V m(-1) , and outgrowth was studied one week after exposure. The exposure to higher amplitude (41 V m(-1)) GSM radiation resulted in diminished outgrowth of the epicotyl. The exposure to lower amplitude (5.7 V m(-1)) GSM radiation did not influence outgrowth of epicotyl, hypocotyls, or roots. The exposure to higher amplitude CW radiation resulted in reduced outgrowth of the roots whereas lower CW exposure resulted in a reduced outgrowth of the hypocotyl. Soybean seedlings were also exposed for 5 days to an extremely low level of radiation (GSM 900 MHz, 0.56 V m(-1)) and outgrowth was studied 2 days later. Growth of epicotyl and hypocotyl was found to be reduced, whereas the outgrowth of roots was stimulated. Our findings indicate that the observed effects were significantly dependent on field strength as well as amplitude modulation of the applied field. © 2015 Wiley Periodicals, Inc.

  5. VHF/UHF radar observations of tropical mesoscale convective systems over southern India

    Directory of Open Access Journals (Sweden)

    K. Kishore Kumar

    2005-07-01

    Full Text Available Several campaigns have been carried out to study the convective systems over Gadanki (13.5° N, 79.2° E, a tropical station in India, using VHF and UHF radars. The height-time sections of several convective systems are investigated in detail to study reflectivity, turbulence and vertical velocity structure. Structure and dynamics of the convective systems are the main objectives of these campaigns. The observed systems are classified into single- and multi-cell systems. It has been observed that most of the convective systems at this latitude are multi-cellular in nature. Simultaneous VHF and UHF radar observations are used to classify the observed precipitating systems as convective, intermediary and stratiform regions. Composite height profiles of vertical velocities in these regions were obtained and the same were compared with the profiles obtained at other geographical locations. These composite profiles of vertical velocity in the convective regions have shown their peaks in the mid troposphere, indicating that the maximum latent heat is being released at those heights. These profiles are very important for numerical simulations of the convective systems, which vary significantly from one geographical location to the other. Keywords. Meteorology and atmospheric dynamics (Mesoscale meteorology; Convective processes – Radio science (Remote sensing

  6. Advances in microwaves 3

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 3 covers the advances and applications of microwave signal transmission and Gunn devices. This volume contains six chapters and begins with descriptions of ground-station antennas for space communications. The succeeding chapters deal with beam waveguides, which offer interesting possibilities for transmitting microwave energy, as well as with parallel or tubular beams from antenna apertures. A chapter discusses the electron transfer mechanism and the velocity-field characteristics, with a particular emphasis on the microwave properties of Gunn oscillators. The l

  7. VHF signal power suppression in stratiform and convective precipitation

    Directory of Open Access Journals (Sweden)

    A. J. McDonald

    2006-03-01

    Full Text Available Previous studies have indicated that VHF clear-air radar return strengths are reduced during periods of precipitation. This study aims to examine whether the type of precipitation, stratiform and convective precipitation types are identified, has any impact on the relationships previously observed and to examine the possible mechanisms which produce this phenomenon. This study uses a combination of UHF and VHF wind-profiler data to define periods associated with stratiform and convective precipitation. This identification is achieved using an algorithm which examines the range squared corrected signal to noise ratio of the UHF returns for a bright band signature for stratiform precipitation. Regions associated with convective rainfall have been defined by identifying regions of enhanced range corrected signal to noise ratio that do not display a bright band structure and that are relatively uniform until a region above the melting layer.

    This study uses a total of 68 days, which incorporated significant periods of surface rainfall, between 31 August 2000 and 28 February 2002 inclusive from Aberystwyth (52.4° N, 4.1° W. Examination suggests that both precipitation types produce similar magnitude reductions in VHF signal power on average. However, the frequency of occurrence of statistically significant reductions in VHF signal power are very different. In the altitude range 2-4 km stratiform precipitation is related to VHF signal suppression approximately 50% of the time while in convective precipitation suppression is observed only 27% of the time. This statistical result suggests that evaporation, which occurs more often in stratiform precipitation, is important in reducing the small-scale irregularities in humidity and thereby the radio refractive index. A detailed case study presented also suggests that evaporation reducing small-scale irregularities in humidity may contribute to the observed VHF signal

  8. VHF signal power suppression in stratiform and convective precipitation

    Directory of Open Access Journals (Sweden)

    A. J. McDonald

    2006-03-01

    Full Text Available Previous studies have indicated that VHF clear-air radar return strengths are reduced during periods of precipitation. This study aims to examine whether the type of precipitation, stratiform and convective precipitation types are identified, has any impact on the relationships previously observed and to examine the possible mechanisms which produce this phenomenon. This study uses a combination of UHF and VHF wind-profiler data to define periods associated with stratiform and convective precipitation. This identification is achieved using an algorithm which examines the range squared corrected signal to noise ratio of the UHF returns for a bright band signature for stratiform precipitation. Regions associated with convective rainfall have been defined by identifying regions of enhanced range corrected signal to noise ratio that do not display a bright band structure and that are relatively uniform until a region above the melting layer. This study uses a total of 68 days, which incorporated significant periods of surface rainfall, between 31 August 2000 and 28 February 2002 inclusive from Aberystwyth (52.4° N, 4.1° W. Examination suggests that both precipitation types produce similar magnitude reductions in VHF signal power on average. However, the frequency of occurrence of statistically significant reductions in VHF signal power are very different. In the altitude range 2-4 km stratiform precipitation is related to VHF signal suppression approximately 50% of the time while in convective precipitation suppression is observed only 27% of the time. This statistical result suggests that evaporation, which occurs more often in stratiform precipitation, is important in reducing the small-scale irregularities in humidity and thereby the radio refractive index. A detailed case study presented also suggests that evaporation reducing small-scale irregularities in humidity may contribute to the observed VHF signal suppression.

  9. From VHF to UHF CMOS-MEMS Monolithically Integrated Resonators

    DEFF Research Database (Denmark)

    Teva, Jordi; Berini, Abadal Gabriel; Uranga, A.

    2008-01-01

    This paper presents the design, fabrication and characterization of microresonators exhibiting resonance frequencies in the VHF and UHF bands, fabricated using the available layers of the standard and commercial CMOS technology, AMS-0.35mum. The resonators are released in a post-CMOS process cons...

  10. Phase and coherence analysis of VHF scintillation over Christmas Island

    Directory of Open Access Journals (Sweden)

    E. B. Shume

    2014-03-01

    Full Text Available This short paper presents phase and coherence data from the cross-wavelet transform applied on longitudinally separated very high frequency (VHF equatorial ionospheric scintillation observations over Christmas Island. The phase and coherence analyses were employed on a pair of scintillation observations, namely, the east-looking and west-looking VHF scintillation monitors at Christmas Island. Our analysis includes 3 years of peak season scintillation data from 2008, 2009 (low solar activity, and 2011 (moderate solar activity. In statistically significant and high spectral coherence regions of the cross-wavelet transform, scintillation observations from the east-looking monitor lead those from the west-looking monitor by about 20 to 60 (40 ± 20 min (most frequent lead times. Using several years (seasons and solar cycle of lead (or lag and coherence information of the cross-wavelet transform, we envisage construction of a probability model for forecasting scintillation in the nighttime equatorial ionosphere.

  11. 47 CFR 101.141 - Microwave modulation.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Microwave modulation. 101.141 Section 101.141... SERVICES Technical Standards § 101.141 Microwave modulation. (a) Microwave transmitters employing digital modulation techniques and operating below 25.25 GHz (except for MVDDS stations in the 12,200-12,700 MHz band...

  12. PMSE Observations With the Tri-Static EISCAT VHF Radars

    Science.gov (United States)

    Mann, I.; Tjulin, A.; Häggström, I.

    2013-12-01

    The polar mesospheric summer echoes (PMSE) are generated in the ionosphere at roughly 80 to 90 altitude by electron irregularities in the presence of charged solid particles and PMSE are most likely observed when ice particles form onto nanodust. PMSE formation is an important part in understanding mesospheric processes, but is also an interesting example for dusty plasma phenomena occurring in space. To investigate the phenomena that lead to formation of PMSE it is helpful to study the radar reflectivity of the mesosphere at different angles. PMSE were previously studied at different aspect angles in order to better understand the scattering process. Another way is observing PMSE from multiple sites simultaneously. During this summer the EISCAT radars that are located in Northern Scandinavia could for the first time be used for tri-static observations in the VHF band and we carried out observations during three subsequent days in June 2013. The radar signal was transmitted in zenith direction with the EISCAT VHF antenna near Tromsø (69.59 deg N, 19.23 deg E) and the scattered signal was measured from Tromsø, Kiruna (67.86 deg N, 20.44 deg E) and Sodankylä (67.36 deg N, 26.63 deg E). Zenith observations were simultaneously carried out with the Tromsø UHF radar (933 MHz). Other groups have previously reported the observations of PMSE simultaneously with the EISCAT VHF and UHF radars, but with a much lower occurrence rate for the UHF. UHF observations made during this campaign are dominated by incoherent scatter. The VHF system in Tromsø detected PMSE for a large fraction of the observation time. The VHF receivers in Kiruna and Sodankylä were pointed at typical PMSE heights above the Tromsø transmitter and detected radar reflections at the same time and altitude as the Tromsø radar. These observations are among the first tri-static observations of PMSE. Preliminary results from the campaign will be presented and discussed.

  13. Microwave engineering

    CERN Document Server

    Pozar, David M

    2012-01-01

    The 4th edition of this classic text provides a thorough coverage of RF and microwave engineering concepts, starting from fundamental principles of electrical engineering, with applications to microwave circuits and devices of practical importance.  Coverage includes microwave network analysis, impedance matching, directional couplers and hybrids, microwave filters, ferrite devices, noise, nonlinear effects, and the design of microwave oscillators, amplifiers, and mixers. Material on microwave and RF systems includes wireless communications, radar, radiometry, and radiation hazards. A large

  14. The first operation and results of the Chung-Li VHF radar

    Science.gov (United States)

    Chao, J. K.; Kuo, F. S.; Chu, Y. S.; Fu, I. J.; Rottger, J.; Liu, C. H.

    1986-01-01

    The Chung-Li Very High Frequency (VHF) radar is used in the dual-mode operations, applying Doppler beam-swinging as well as the spaced-antenna-drift method. The design of the VHF radar is examined. Results of performance tests are discussed.

  15. Very Compact and Broadband Active Antenna for VHF Band Applications

    Directory of Open Access Journals (Sweden)

    Y. Taachouche

    2012-01-01

    Full Text Available An active receiving antenna with small size consisting of a monopole loaded with a transistor bipolar is presented in this paper. A transistor is used in order to miniaturize the receiving active antenna size in VHF band. The vertical size of the structure is equal to λ/175, where λ is the wavelength at the lower frequency of the bandwidth. Despite the very small size of the antenna, the frequency bandwidth is very wide and the gain is suitable for FM application with sensitive receivers.

  16. Space Station galley design

    Science.gov (United States)

    Trabanino, Rudy; Murphy, George L.; Yakut, M. M.

    1986-01-01

    An Advanced Food Hardware System galley for the initial operating capability (IOC) Space Station is discussed. Space Station will employ food hardware items that have never been flown in space, such as a dishwasher, microwave oven, blender/mixer, bulk food and beverage dispensers, automated food inventory management, a trash compactor, and an advanced technology refrigerator/freezer. These new technologies and designs are described and the trades, design, development, and testing associated with each are summarized.

  17. Microwave imaging

    CERN Document Server

    Pastorino, Matteo

    2010-01-01

    An introduction to the most relevant theoretical and algorithmic aspects of modern microwave imaging approaches Microwave imaging-a technique used in sensing a given scene by means of interrogating microwaves-has recently proven its usefulness in providing excellent diagnostic capabilities in several areas, including civil and industrial engineering, nondestructive testing and evaluation, geophysical prospecting, and biomedical engineering. Microwave Imaging offers comprehensive descriptions of the most important techniques so far proposed for short-range microwave imaging-in

  18. Miniaturization for ultrathin metamaterial perfect absorber in the VHF band

    Science.gov (United States)

    Khuyen, Bui Xuan; Tung, Bui Son; Yoo, Young Joon; Kim, Young Ju; Kim, Ki Won; Chen, Liang-Yao; Lam, Vu Dinh; Lee, Youngpak

    2017-03-01

    An efficient resolution for ultrathin metamaterial perfect absorber (MPA) is proposed and demonstrated in the VHF radio band (30-300 MHz). By adjusting the lumped capacitors and the through vertical interconnects, the absorber is miniaturized to be only λ/816 and λ/84 for its thickness and periodicity with respect to the operating wavelength (at 102 MHz), respectively. The detailed simulation and calculation show that the MPA can maintain an absorption rate over 90% in a certain range of incident angle and with a wide variation of capacitance. Additionally, we utilized the advantages of the initial single-band structure to realize a nearly perfect dual-band absorber in the same range. The results were confirmed by both simulation and experiment at oblique incidence angles up to 50°. Our work is expected to contribute to the actualization of future metamaterial-based devices working at radio frequency.

  19. 47 CFR 101.213 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 101.213 Section 101.213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Operational Requirements § 101.213 Station identification. Stations in these services are exempt...

  20. Microwave thawing of frozen parenteral solutions.

    Science.gov (United States)

    Walter, C W; Pauly, J A; Ausman, R K; Kundsin, R B; Holmes, C J

    1983-01-01

    A commercially available microwave oven modified for use at medication stations throughout hospitals allows timely thawing of frozen parenteral solutions. The inherent problems of safety and uniform heating have been overcome, thus making possible the preparation, storage, and distribution of admixtures on a regional basis and ensuring the integrity of the product. Most parenteral medications are not degraded by microwave energy, and thawing by microwave energy permits timely administration and allows coordination of medication for a series of patients.

  1. DSS 13 phase 2 pedestal room microwave layout

    Science.gov (United States)

    Cwik, T.; Chen, J. C.

    1991-01-01

    The design and predicted performance is described of the microwave layout for three band operation of the beam waveguide antenna Deep Space Station 13. Three pedestal room microwave candidate layout designs were produced for simultaneous X/S and X/Ka band operation. One of the three designs was chosen based on given constraints, and for this design the microwave performance was estimated.

  2. CW 100MW microwave power transfer in space

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, K. (Houston Univ., TX (United States). Inst. for Beam Particle Dynamics National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan) Texas Accelerator Center, The Woodlands, TX (United States)); Hiramatsu, S. (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)); Shiho, M. (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan))

    1991-01-01

    A proposal is made for high-power microwave transfer in space. The concept consists in a microwave power station integrating a multistage microwave free-electron laser and asymmetric dual-reflector system. Its use in space is discussed. 9 refs., 2 figs., 1 tab.

  3. Development Of VHF (240-270 MHz) Antennas For SoOp (Signal Of Opportunity) Receiver For 6u Cubesat Platforms

    Science.gov (United States)

    Joseph, A. T.; Deshpande, M.; O'Neill, P. E.; Miles, L.

    2016-01-01

    The main goal of this research is to design, fabricate, and test deployable VHF antennas for 6U Cubesat platforms to enable validation of root zone soil moisture (RZSM) estimation algorithms for signal of opportunity (SoOp) remote sensing over the 240-270 MHz frequency band. The proposed work provides a strong foundation for establishing a technology development path for maturing a truly global direct surface soil moisture (SM) and RZSM measurement system (Figure 1) over a variety of land covers with limited density restrictions. In SoOp methodology, signals transmitted by already existing transmitters (known as transmitters of opportunity, in this case the Military Satellite Communication (MilSatCom) System's UHF Follow-On program) are utilized to measure properties of reflecting targets by recording reflected signals using a simple passive microwave receiver.

  4. 75 FR 74719 - Auction of VHF Commercial Television Station Construction Permits Scheduled for February 15, 2011...

    Science.gov (United States)

    2010-12-01

    ... does an FCC construction permit or license constitute a guarantee of business success. Applicants... reminded, however, that events occurring after the short-form filing deadline, such as the acquisition of... control of an applicant, resulting from a merger for example, will be considered a major modification to...

  5. 75 FR 57947 - Auction of VHF Commercial Television Station Construction Permits Scheduled for February 15, 2011...

    Science.gov (United States)

    2010-09-23

    ... transaction data. The proposed minimum opening bid amounts are $200,000 for each construction permit available...; Comment Sought on Competitive Bidding Procedures for Auction 90 AGENCY: Federal Communications Commission... bidding procedures for Auction 90. DATES: Comments are due on or before September 30, 2010, and reply...

  6. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  7. Microwave Irradiation

    Indian Academy of Sciences (India)

    The rapid heating of food in the kitchen using microwave ovens ... analysis; application to waste treatment; polymer technology; .... Microwave heating for carrying out reactions on solids has also attracted considerable attention in recent years. For such 'dry media' reactions, solid supports such as alumina, silica and.

  8. Letter to the Editor: Complete maps of the aspect sensitivity of VHF atmospheric radar echoes

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    1999-08-01

    Full Text Available Using the MU radar at Shigaraki, Japan (34.85°N, 136.10°E, we measure the power distribution pattern of VHF radar echoes from the mid-troposphere. The large number of radar beam-pointing directions (320 allows the mapping of echo power from 0° to 40° from zenith, and also the dependence on azimuth, which has not been achieved before at VHF wavelengths. The results show how vertical shear of the horizontal wind is associated with a definite skewing of the VHF echo power distribution, for beam angles as far as 30° or more from zenith, so that aspect sensitivity cannot be assumed negligible at any beam-pointing angle that most existing VHF radars are able to use. Consequently, the use of VHF echo power to calculate intensity of atmospheric turbulence, which assumes only isotropic backscatter at large beam zenith angles, will sometimes not be valid.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; turbulence; instruments and techniques

  9. PENUMBUHAN LAPISAN TIPIS SILIKON MIKROKRISTAL TERHIDROGENASI DENGAN TEKNIK HWC-VHF-PECVD

    Directory of Open Access Journals (Sweden)

    Ida Usman

    2012-02-01

    Full Text Available Telah dikembangkan teknik HWC-VHF-PECVD (Hot Wire Cell Very High Frequency Plasma Enhanced Chemical Vapor Deposition untuk menumbuhkan lapisan tipis silikon mikrokristal terhidrogenasi (mc-Si:H. Dari hasil penumbuhan lapisan tipis yang dilakukan, teknik HWC-VHF-PECVD memperlihatkan laju deposisi yang lebih tinggi dibandingkan laju deposisi lapisan tipis yang diperoleh dari teknik PECVD maupun teknik VHF-PECVD konvensional. Berdasarkan hasil pengukuran XRD dan SEM, lapisan yang diperoleh pada temperatur filamen yang rendah masih berstruktur amorf. Indikasi yang mengarah pada pembentukan lapisan tipis berstruktur mikrokristalin mulai terlihat pada temperatur filamen ≥ 500oC, dimana puncak-puncak di fraksi spektrum XRD untuk orientasi kristalin tertentu mulai terbentu, sejalan dengan pembentukan butiran-butiran kristalin dari hasil foto SEM permukaan lapisan-lapisan tersebut.

  10. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  11. Microwave Measurements

    CERN Document Server

    Skinner, A D

    2007-01-01

    The IET has organised training courses on microwave measurements since 1983, at which experts have lectured on modern developments. Their lecture notes were first published in book form in 1985 and then again in 1989, and they have proved popular for many years with a readership beyond those who attended the courses. The purpose of this third edition of the lecture notes is to bring the latest techniques in microwave measurements to this wider audience. The book begins with a survey of the theory of current microwave circuits and continues with a description of the techniques for the measureme

  12. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2013-01-01

    Microwave photonics continues to see rapid growth. The integration of optical fiber and wireless networks has become a commercial reality and is becoming increasingly pervasive. Such hybrid technology will lead to many innovative applications, including backhaul solutions for mobile networks and ultrabroadband wireless networks that can provide users with very high bandwidth services. Microwave Photonics, Second Edition systematically introduces important technologies and applications in this emerging field. It also reviews recent advances in micro- and millimeter-wavelength and terahertz-freq

  13. Microwave materials for wireless applications

    CERN Document Server

    Cruickshank, David B

    2011-01-01

    This practical resource offers you an in-depth, up-to-date understanding of the use of microwave magnetic materials for cutting-edge wireless applications. The book discusses device applications used in wireless infrastructure base stations, point-to-point radio links, and a range of more specialized microwave systems. You find detailed discussions on the attributes of each family of magnetic materials with respect to specific wireless applications. Moreover, the book addresses two of the hottest topics in the field today - insertion loss and intermodulation. This comprehensive reference also

  14. A VHF Class E DC-DC Converter with Self-Oscillating Gate Driver

    DEFF Research Database (Denmark)

    Andersen, Toke Meyer; Christensen, Søren K.; Knott, Arnold

    2011-01-01

    This paper describes the analysis and design of a DC-DC converter topology which is operational at frequencies in the Very High Frequency (VHF) band ranging from 30 MHz − 300 MHz. The presented topology, which consists of a class E inverter, class E rectifier, and self-oscillating gate driver, is...

  15. First wind shear observation in PMSE with the tristatic EISCAT VHF radar

    Science.gov (United States)

    Mann, I.; Häggström, I.; Tjulin, A.; Rostami, S.; Anyairo, C. C.; Dalin, P.

    2016-11-01

    The Polar Summer Mesosphere has the lowest temperatures that occur in the entire Earth system. Water ice particles below the optically observable size range participate there in the formation of strong radar echoes (Polar Mesospheric Summer Echoes, PMSE). To study PMSE we carried out observations with the European Incoherent Scatter (EISCAT) VHF and EISCAT UHF radar simultaneously from a site near Tromsø (69.58°N, 19.2272°E) and observed VHF backscattering also with the EISCAT receivers in Kiruna (67.86°N, 20.44°E) and Sodankylä (67.36°N, 26.63°E). This is one of the first tristatic measurements with EISCAT VHF, and we therefore describe the observations and geometry in detail. We present observations made on 26 June 2013 from 7:00 to 13:00 h UT where we found similar PMSE patterns with all three VHF receivers and found signs of wind shear in PMSE. The observations suggest that the PMSE contains sublayers that move in different directions horizontally, and this points to Kelvin-Helmholtz instability possibly playing a role in PMSE formation. We find no signs of PMSE in the UHF data. The electron densities that we derive from observed incoherent scatter at UHF are at PMSE altitudes close to the noise level but possibly indicate reduced electron densities directly above the PMSE.

  16. VHF/UHF filters and multicouplers application of air resonators

    CERN Document Server

    Piette, Bernard

    2013-01-01

    This book describes the various devices used in radio communication and broadcasting to achieve high selectivity filtering and coupling. After providing a background in the basics of microwave theory and more detailed material - including a special chapter on precision and errors in measurement - the reader will find detailed descriptions, manufacturing processes, and, for the most useful instances, a number of worked-through formulas, which will allow engineers and technicians to design circuits or components for filtering or coupling applications. Content is covered in this format across a b

  17. Testing VHF/GPS collar design and safety in the study of free-roaming horses.

    Directory of Open Access Journals (Sweden)

    Gail H Collins

    Full Text Available Effective and safe monitoring techniques are needed by U.S. land managers to understand free-roaming horse behavior and habitat use and to aid in making informed management decisions. Global positioning system (GPS and very high frequency (VHF radio collars can be used to provide high spatial and temporal resolution information for detecting free-roaming horse movement. GPS and VHF collars are a common tool used in wildlife management, but have rarely been used for free-roaming horse research and monitoring in the United States. The purpose of this study was to evaluate the design, safety, and detachment device on GPS/VHF collars used to collect free-roaming horse location and movement data. Between 2009 and 2010, 28 domestic and feral horses were marked with commercial and custom designed VHF/GPS collars. Individual horses were evaluated for damage caused by the collar placement, and following initial observations, collar design was modified to reduce the potential for injury. After collar modifications, which included the addition of collar length adjustments to both sides of the collar allowing for better alignment of collar and neck shapes, adding foam padding to the custom collars to replicate the commercial collar foam padding, and repositioning the detachment device to reduce wear along the jowl, we observed little to no evidence of collar wear on horses. Neither custom-built nor commercial collars caused injury to study horses, however, most of the custom-built collars failed to collect data. During the evaluation of collar detachment devices, we had an 89% success rate of collar devices detaching correctly. This study showed that free-roaming horses can be safely marked with GPS and/or VHF collars with minimal risk of injury, and that these collars can be a useful tool for monitoring horses without creating a risk to horse health and wellness.

  18. An analysis on the mid-latitude scintillation and coherence frequency bandwidth using transionospheric VHF signals

    Energy Technology Data Exchange (ETDEWEB)

    Juang, Zhen [Los Alamos National Laboratory; Roussel-dupre, Robert [Los Alamos National Laboratory

    2008-01-01

    An analysis was perfonned on the mid-latitude scintillation and coherence frequency bandwidth (Fcoh) using transionospheric VHF signal data. The data include 1062 events spanning from November 1997 to June 2002. Each event records FORTE satellite received VHF signals from LAPP located at Los Alamos, New Mexico. Fcohs were derived to study scintillation characteristics on diurnal and seasonal variations, as well as changes due to solar and geomagnetic activities. Comparisons to the VHFIUHF coherence frequency bandwidth studies previously reported at equatorial and mid-latitude regions are made using a 4th power frequency dependence relationship. Furthennore, a wideband ionospheric scintillation model, WBMOD, was used to estimate Fcohs and compared with our VHF Fcoh values. Our analysis indicates mid-latitude scintillation characteristics that are not previously revealed. At the VHF bottom frequency range (3035 MHz), distinguished smaller Fcohs are found in time period from sunset to midnight, in wann season from May to August, and in low solar activity years. The effects of geomagnetic storm activity on Fcoh are characterized by a sudden transition at a Kp index of 50-60. Comparisons with median Fcohs estimated from other studies validated our VHF Fcohs for daytime while an order of magnitude larger Fcohs are found for nighttime, implying a time-dependent issue in applying the 4th order power relationship. Furthermore, comparisons with WBMOD-estimated Fcohs indicated generally matched median scintillation level estimates while differences do exist for those events undergoing high geomagnetic stonn activity which may imply underestimates of scintillation level by the WBMOD in the mid-latitude regions.

  19. Molecular Switching in Confined Spaces: Effects of Encapsulating the DHA/VHF Photo-Switch in Cucurbiturils

    DEFF Research Database (Denmark)

    Petersen, Michael Å.; Rasmussen, Brian; Andersen, Nicolaj N.

    2017-01-01

    complexes, the kinetics of the thermal VHF-to-DHA back-reaction is accelerated, while in CB8 inclusion complexes, the kinetics is slowed down as compared to the free photo-switch. The effect of the CB encapsulation of the photo-switch can be effectively canceled by introducing a guest that binds the CB more...... strongly. According to DFT calculations, a stabilization of the reactive s-cis VHF conformer relative to the s-trans VHF appears to be a contributing factor responsible for the accelerated back-reaction when encapsulated in CB7....

  20. Fire Stations

    Data.gov (United States)

    Department of Homeland Security — Fire Stations in the United States Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their...

  1. A Microwave Thruster for Spacecraft Propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Chiravalle, Vincent P [Los Alamos National Laboratory

    2012-07-23

    This presentation describes how a microwave thruster can be used for spacecraft propulsion. A microwave thruster is part of a larger class of electric propulsion devices that have higher specific impulse and lower thrust than conventional chemical rocket engines. Examples of electric propulsion devices are given in this presentation and it is shown how these devices have been used to accomplish two recent space missions. The microwave thruster is then described and it is explained how the thrust and specific impulse of the thruster can be measured. Calculations of the gas temperature and plasma properties in the microwave thruster are discussed. In addition a potential mission for the microwave thruster involving the orbit raising of a space station is explored.

  2. Investigation into the Effects of VHF and UHF Band Radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

    National Research Council Canada - National Science Library

    Dickens, Andrew

    1994-01-01

    This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards...

  3. Investigation into the effects of VHF and UHF band radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

    Science.gov (United States)

    Dickens, Andrew

    1995-01-01

    This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards. Tests carried out on the basis of these reports show that sources of VHF and UHF radiation such as two-way hand held police communications devices do cause reproducible adverse effects. This investigation examines reproducible effects and explores possible causes.

  4. Microwave Sterilization and Depyrogenation System

    Science.gov (United States)

    Akse, James R.; Dahl, Roger W.; Wheeler, Richard R., Jr.

    2009-01-01

    A fully functional, microgravity-compatible microwave sterilization and depyrogenation system (MSDS) prototype was developed that is capable of producing medical-grade water (MGW) without expendable supplies, using NASA potable water that currently is available aboard the International Space Station (ISS) and will be available for Lunar and planetary missions in the future. The microwave- based, continuous MSDS efficiently couples microwaves to a single-phase, pressurized, flowing water stream that is rapidly heated above 150 C. Under these conditions, water is rapidly sterilized. Endotoxins, significant biological toxins that originate from the cell walls of gram-negative bacteria and which represent another defining MGW requirement, are also deactivated (i.e., depyrogenated) albeit more slowly, with such deactivation representing a more difficult challenge than sterilization. Several innovations culminated in the successful MSDS prototype design. The most significant is the antenna-directed microwave heating of a water stream flowing through a microwave sterilization chamber (MSC). Novel antenna designs were developed to increase microwave transmission efficiency. These improvements resulted in greater than 95-percent absorption of incident microwaves. In addition, incorporation of recuperative heat exchangers (RHxs) in the design reduced the microwave power required to heat a water stream flowing at 15 mL/min to 170 C to only 50 W. Further improvements in energy efficiency involved the employment of a second antenna to redirect reflected microwaves back into the MSC, eliminating the need for a water load and simplifying MSDS design. A quick connect (QC) is another innovation that can be sterilized and depyrogenated at temperature, and then cooled using a unique flow design, allowing collection of MGW at atmospheric pressure and 80 C. The final innovation was the use of in-line mixers incorporated in the flow path to disrupt laminar flow and increase contact time

  5. Broadband VHF observations for lightning impulses from a small satellite SOHLA-1 (Maido 1)

    Science.gov (United States)

    Morimoto, T.; Kikuchi, H.; Ushio, T.; Kawasaki, Z.; Hidekazu, H.; Aoki, T.

    2009-12-01

    Lightning Research Group of Osaka University (LRG-OU) has been developing VHF Broadband Digital Interferometer (DITF) to image precise lightning channels and monitor lightning activity widely. The feature of broadband DITF is its ultrawide bandwidth (from 25MHz to 100MHz) and implicit redundancy for estimating VHF source location. LRG-OU considers an application of the broadband DITF to the spaceborne measurement system and joins the SOHLA (Space Oriented Higashi-Osaka Leading Associate) satellite project. The SOHLA satellite project represents a technology transfer program to expand the range of the space development community in Japan. The objective is to get SMEs (Small and Medium sized manufacturing Enterprises) involved in small space projects and new space technologies. Under the cooperative agreement, JAXA (Japan Aerospace Exploration Agency) intends to contribute to socio-economic development by returning its R&D results to society, and SOHLA tries to revitalize the local economy through the commercialization of versatile small satellites. According to the agreement, JAXA provides SOHLA its technical information on small satellites and other technical assistance for the development of the small satellites, SOHLA-1. The prime objective of the SOHLA-1 program is to realize low-cost and short term development of a microsatellite which utilizes the components and bus technologies of JAXA’s MicroLabSat. SOHLA-1 is a spin-stabilized microsatellite of MicroLabSat heritage (about 50 kg). The spin axis is fixed to inertial reference frame. The spin axis (z-axis) lies in the plane containing the solar direction and the normal to the orbital plane. LRG-OU takes responsibility for a science mission of SOHLA-1. To examine the feasibility of the DITF receiving VHF lightning impulses in space, LRG-OU proposes the BMW (Broadband Measurement of Waveform for VHF Lightning Impulses). BMW consists of a single pair of an antenna, a band-pass filter, an amplifier, and an

  6. Comparison study of Lightning VHF interferometric and LF time-of-arival maps

    Science.gov (United States)

    Kudo, A.; Stock, M.; Kawasaki, Z.; Ushio, T.

    2016-12-01

    Lightning discharges radiate broad band frequency electromagnetic waves from ULF to UHF. Using sensors which detect this radiation is an effective technique to detect lightning flashes, even if they are in a cloud. If multiple sensors are present, a lightning flash can be located using various techniques. At low frequencies, the power radiated by lightning is very high, but because the wavelengths are long, the location resolution is somewhat low. At very high frequencies, the wavelengths are much shorter allowing for much better location resolution, but the power radiation is also much lower, making it more difficult to detect. The VHF band is a good compromise between good location resolution, and good detection efficiency. One technique to locate VHF signals from lightning is interferometry. Using this technique, the signals arriving at three or more VHF broadband antennas are coherently combined to produce an image of the lightning flash. The current generation broadband lightning interferometer being developed in Japan by RAIRAN and the University of Osaka called Lightning Interferometer via VHF Emission (LIVE). Currently, LIVE is installed in Kaizuka, a city to the south of Osaka, near Osaka Bay to observe Japanese summer lightning. In the current study, we are comparing the high detail, 2-dimensional lightning maps produced by LIVE to the lower detail, 3-dimensional maps produced by a low frequency time-of-arrival system called the Broadband Observation network for Lightning and Thunderstorms (BOLT). In order to better compare the data, a new GPS timing device is being developed for LIVE to allow high absolute timing accuracy without sacrificing one of the 4 high speed digitizer channels. The objectives of the study are to better understand Japanese summer lightning, and to prepare for a future campaign as part of the GLM validation study.

  7. Bias-Voltage Stabilizer for HVHF Amplifiers in VHF Pulse-Echo Measurement Systems

    Directory of Open Access Journals (Sweden)

    Hojong Choi

    2017-10-01

    Full Text Available The impact of high-voltage–high-frequency (HVHF amplifiers on echo-signal quality is greater with very-high-frequency (VHF, ≥100 MHz ultrasound transducers than with low-frequency (LF, ≤15 MHz ultrasound transducers. Hence, the bias voltage of an HVHF amplifier must be stabilized to ensure stable echo-signal amplitudes. We propose a bias-voltage stabilizer circuit to maintain stable DC voltages over a wide input range, thus reducing the harmonic-distortion components of the echo signals in VHF pulse-echo measurement systems. To confirm the feasibility of the bias-voltage stabilizer, we measured and compared the deviations in the gain of the HVHF amplifier with and without a bias-voltage stabilizer. Between −13 and 26 dBm, the measured gain deviations of a HVHF amplifier with a bias-voltage stabilizer are less than that of an amplifier without a bias-voltage stabilizer. In order to confirm the feasibility of the bias-voltage stabilizer, we compared the pulse-echo responses of the amplifiers, which are typically used for the evaluation of transducers or electronic components used in pulse-echo measurement systems. From the responses, we observed that the amplitudes of the echo signals of a VHF transducer triggered by the HVHF amplifier with a bias-voltage stabilizer were higher than those of the transducer triggered by the HVHF amplifier alone. The second, third, and fourth harmonic-distortion components of the HVHF amplifier with the bias-voltage stabilizer were also lower than those of the HVHF amplifier alone. Hence, the proposed scheme is a promising method for stabilizing the bias voltage of an HVHF amplifier, and improving the echo-signal quality of VHF transducers.

  8. First wind shear observation in PMSE with the tristatic EISCAT VHF radar

    OpenAIRE

    Mann, Ingrid; Häggström, I.; Tjulin, A; Rostami, S; Anyairo, CC; Dalin, P

    2016-01-01

    (c) American Geophysical Union, reprinted with permission. Article also available at source: https://doi.org/10.1002/2016JA023080 The Polar Summer Mesosphere has the lowest temperatures that occur in the entire Earth system. Water ice particles below the optically observable size range participate there in the formation of strong radar echoes (Polar Mesospheric Summer Echoes, PMSE). To study PMSE we carried out observations with the European Incoherent Scatter (EISCAT) VHF and EIS...

  9. Bias-Voltage Stabilizer for HVHF Amplifiers in VHF Pulse-Echo Measurement Systems.

    Science.gov (United States)

    Choi, Hojong; Park, Chulwoo; Kim, Jungsuk; Jung, Hayong

    2017-10-23

    The impact of high-voltage-high-frequency (HVHF) amplifiers on echo-signal quality is greater with very-high-frequency (VHF, ≥100 MHz) ultrasound transducers than with low-frequency (LF, ≤15 MHz) ultrasound transducers. Hence, the bias voltage of an HVHF amplifier must be stabilized to ensure stable echo-signal amplitudes. We propose a bias-voltage stabilizer circuit to maintain stable DC voltages over a wide input range, thus reducing the harmonic-distortion components of the echo signals in VHF pulse-echo measurement systems. To confirm the feasibility of the bias-voltage stabilizer, we measured and compared the deviations in the gain of the HVHF amplifier with and without a bias-voltage stabilizer. Between -13 and 26 dBm, the measured gain deviations of a HVHF amplifier with a bias-voltage stabilizer are less than that of an amplifier without a bias-voltage stabilizer. In order to confirm the feasibility of the bias-voltage stabilizer, we compared the pulse-echo responses of the amplifiers, which are typically used for the evaluation of transducers or electronic components used in pulse-echo measurement systems. From the responses, we observed that the amplitudes of the echo signals of a VHF transducer triggered by the HVHF amplifier with a bias-voltage stabilizer were higher than those of the transducer triggered by the HVHF amplifier alone. The second, third, and fourth harmonic-distortion components of the HVHF amplifier with the bias-voltage stabilizer were also lower than those of the HVHF amplifier alone. Hence, the proposed scheme is a promising method for stabilizing the bias voltage of an HVHF amplifier, and improving the echo-signal quality of VHF transducers.

  10. Microwave Filters

    OpenAIRE

    Zhou, Jiafeng

    2010-01-01

    The general theory of microwave filter design based on lumped-element circuit is described in this chapter. The lowpass prototype filters with Butterworth, Chebyshev and quasielliptic characteristics are synthesized, and the prototype filters are then transformed to bandpass filters by lowpass to bandpass frequency mapping. By using immitance inverters ( J - or K -inverters), the bandpass filters can be realized by the same type of resonators. One design example is given to verify the theory ...

  11. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore......, this paper presents methods to analyze station capacity. Four methods to analyze station capacity are developed. The first method is an adapted UIC 406 capacity method that can be used to analyze switch zones and platform tracks at stations that are not too complex. The second method examines the need...... the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station...

  12. Amtrak Stations

    Data.gov (United States)

    Department of Homeland Security — Updated database of the Federal Railroad Administration's (FRA) Amtrak Station database. This database is a geographic data set containing Amtrak intercity railroad...

  13. Advances in microwaves 8

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 8 covers the developments in the study of microwaves. The book discusses the circuit forms for microwave integrated circuits; the analysis of microstrip transmission lines; and the use of lumped elements in microwave integrated circuits. The text also describes the microwave properties of ferrimagnetic materials, as well as their interaction with electromagnetic waves propagating in bounded waveguiding structures. The integration techniques useful at high frequencies; material technology for microwave integrated circuits; specific requirements on technology for d

  14. Structure, optical properties and thermal stability of HfErO films deposited by simultaneous RF and VHF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.Y. [Soochow University, College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou (China); Nanjing University of Posts and Telecommunications, School of Tongda, Nanjing (China); Soochow University, Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Suzhou (China); He, H.J.; Zhang, Z.; Jin, C.G.; Yang, Y.; Wang, Y.Y.; Ye, C. [Soochow University, College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou (China); Soochow University, Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Suzhou (China); Zhuge, L.J. [Soochow University, Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Suzhou (China); Soochow University, Analysis and Testing Center, Suzhou (China); Wu, X.M. [Soochow University, College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou (China); Soochow University, Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Suzhou (China); Chinese Academy of Sciences, State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai (China)

    2015-01-23

    HfErO films are deposited on Si substrates by simultaneous radio frequency (RF) and very high frequency (VHF) magnetron sputtering technique. The content of the doped ingredient of Er and the body composition of HfO{sub x} are, respectively, controlled through the VHF and RF powers. Low content of Er doping in the HfErO films can be achieved, because the VHF source of 27.12 MHz has higher ion energy and lower ion flux than the RF source resulting in low sputtering rate in the magnetron sputtering system. The structure, optical properties and thermal stability of the HfErO films are investigated in this work. Results show that the doped content of Er is independently controlled by the VHF power. The oxygen vacancies are created by the Er incorporation. The hafnium in the HfErO films forms mixed valence of Hf{sup 2+} and Hf{sup 4+}. The HfErO films are composed with the structures of HfO{sub 2}, HfO and ErO{sub x}, which can be optimized through the VHF power. At high VHF power, the Hf-Er-O bonds are formed, which demonstrates that the Er atoms are doped into the lattice of HfO{sub 2} in the HfErO films. The HfErO films have bad thermal stability as the crystallization temperature decreases from 900 to 800 C. After thermal annealing, cubic phase of HfO{sub 2} are stabilized, which is ascribed to the oxygen vacancies creation by the Er incorporation. The optical properties such as the refractive index and the optical band gap of the HfErO films are optimized by the VHF power. (orig.)

  15. VHF radar observation of atmospheric winds, associated shears and C2n at a tropical location: interdependence and seasonal pattern

    Directory of Open Access Journals (Sweden)

    A. R. Jain

    Full Text Available The turbulence refractivity structure constant (C2n is an important parameter of the atmosphere. VHF radars have been used extensively for the measurements of C2n. Presently, most of such observations are from mid and high latitudes and only very limited observations are available for equatorial and tropical latitudes. Indian MST radar is an excellent tool for making high-resolution measurements of atmospheric winds, associated shears and turbulence refractivity structure constant (C2n. This radar is located at Gadanki (13.45° N, 79.18° E, a tropical station in India. The objective of this paper is to bring out the height structure of C2n for different seasons using the long series of data (September 1995 – August 1999 from Indian MST radar. An attempt is also made to understand such changes in the height structure of C2n in relation to background atmospheric parameters such as horizontal winds and associated shears. The height structure of C2n, during the summer monsoon and post-monsoon season, shows specific height features that are found to be related to Tropical Easterly Jet (TEJ winds. It is important to examine the nature of the radar back-scatterers and also to understand the causative mechanism of such scatterers. Aspect sensitivity of the received radar echo is examined for this purpose. It is observed that radar back-scatterers at the upper tropospheric and lower stratospheric heights are more anisotropic, with horizontal correlation length of 10–20 m, as compared to those observed at lower and middle tropospheric heights.Key words. Meteorology and atmospheric dynamics (climatology; tropical meteorology; turbulence

  16. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  17. Measurements methodology for evaluation of Digital TV operation in VHF high-band

    Science.gov (United States)

    Pudwell Chaves de Almeida, M.; Vladimir Gonzalez Castellanos, P.; Alfredo Cal Braz, J.; Pereira David, R.; Saboia Lima de Souza, R.; Pereira da Soledade, A.; Rodrigues Nascimento Junior, J.; Ferreira Lima, F.

    2016-07-01

    This paper describes the experimental setup of field measurements carried out for evaluating the operation of the ISDB-TB (Integrated Services Digital Broadcasting, Terrestrial, Brazilian version) standard digital TV in the VHF-highband. Measurements were performed in urban and suburban areas in a medium-sized Brazilian city. Besides the direct measurements of received power and environmental noise, a measurement procedure involving the injection of Gaussian additive noise was employed to achieve the signal to noise ratio threshold at each measurement site. The analysis includes results of static reception measurements for evaluating the received field strength and the signal to noise ratio thresholds for correct signal decoding.

  18. Luminous phenomena and electromagnetic VHF wave emission originated from earthquake-related radon exhalation

    Science.gov (United States)

    Seki, A.; Tobo, I.; Omori, Y.; Muto, J.; Nagahama, H.

    2013-12-01

    Anomalous luminous phenomena and electromagnetic wave emission before or during earthquakes have been reported (e.g., the 1965 Matsushiro earthquake swarm). However, their mechanism is still unsolved, in spite of many models for these phenomena. Here, we propose a new model about luminous phenomena and electromagnetic wave emission during earthquake by focusing on atmospheric radon (Rn-222) and its daughter nuclides (Po-218 and Po-214). Rn-222, Po-218 and Po-214 are alpha emitters, and these alpha particles ionize atmospheric molecules. A light emission phenomenon, called 'the air luminescence', is caused by de-excitation of the ionized molecules of atmospheric nitrogen due to electron impact ionization from alpha particles. The de-excitation is from the second positive system of neutral nitrogen molecules and the first negative system of nitrogen molecule ion. Wavelengths of lights by these transitions include the visible light wavelength. So based on this mechanism, we proposed a new luminous phenomenon model before or during earthquake: 1. The concentration of atmospheric radon and its daughter nuclides increase anomalously before or during earthquakes, 2. Nitrogen molecules and their ions are excited by alpha particles emitted from Rn-222, Po-218 and Po-214, and air luminescence is generated by their de-excitation. Similarly, electromagnetic VHF wave emission can be explained by ionizing effect of radon and its daughter nuclides. Boyarchuk et al. (2005) proposed a model that electromagnetic VHF wave emission is originated when excited state of neutral clusters changes. Radon gas ionizes atmosphere and forms positively and negatively charged heavy particles. The process of ion hydration in ordinary air can be determined by the formation of complex chemically active structures of the various types of ion radicals. As a result of the association of such hydration radical ions, a neutral cluster, which is dipole quasi-molecules, is formed. A neutral cluster

  19. Observations of Mesospheric Turbulence by Rocket Probe and VHF Radar, Part 2.4A

    Science.gov (United States)

    Royrvik, O.; Smith, L. G.

    1984-01-01

    Data from the Jicamarca VHF radar and from a Languir probe fine-structure on a Nike Orion rocket launched from Punto Lobos, Peru, have been compared. A single mesospheric scattering layer was observed by the radar. The Langmuir probe detected irregularities in the electron-density profile in a narrow region between 85.2 and 86.6 km. It appears from a comparison between these two data sets that turbulence in the neutral atmosphere is the mechanism generating the refractive index irregularities.

  20. An HF and lower VHF spectrum assessment system exploiting instantaneously wideband capture

    Science.gov (United States)

    Barnes, Rod I.; Singh, Malkiat; Earl, Fred

    2017-09-01

    We report on a spectral environment evaluation and recording (SEER) system, for instantaneously wideband spectral capture and characterization in the HF and lower VHF band, utilizing a direct digital receiver coupled to a data recorder. The system is designed to contend with a wide variety of electromagnetic environments and to provide accurately calibrated spectral characterization and display from very short (ms) to synoptic scales. The system incorporates a novel RF front end involving automated gain and equalization filter selection which provides an analogue frequency-dependent gain characteristic that mitigates the high dynamic range found across the HF and lower VHF spectrum. The system accurately calibrates its own internal noise and automatically subtracts this from low variance, external spectral estimates, further extending the dynamic range over which robust characterization is possible. Laboratory and field experiments demonstrate that the implementation of these concepts has been effective. Sensitivity to varying antenna load impedance of the internal noise reduction process has been examined. Examples of software algorithms to provide extraction and visualization of spectral behavior over narrowband, wideband, short, and synoptic scales are provided. Application in HF noise spectral density monitoring, spectral signal strength assessment, and electromagnetic interference detection is possible with examples provided. The instantaneously full bandwidth collection provides some innovative applications, and this is demonstrated by the collection of discrete lightning emissions, which form fast ionograms called "flashagrams" in power-delay-frequency plots.

  1. Measurements and simulation of ionospheric scattering on VHF and UHF radar signals: Channel scattering function

    Science.gov (United States)

    Rogers, Neil C.; Cannon, Paul S.; Groves, Keith M.

    2009-02-01

    The design and operation of transionospheric VHF and UHF radars requires knowledge of amplitude and phase scintillation due to ionospheric scattering. Phase coherence is of particular importance where long coherent integration periods and large bandwidths are required. A thin phase screen, parabolic equation based, Trans-Ionospheric Radio Propagation Simulator (TIRPS) is described. Modeled channel scattering functions (CSFs) are compared to experimental VHF and UHF data derived from the Advanced Research Projects Agency Long-range Tracking and Instrumentation Radar on Kwajalein Island (9.4°N, 166.8°E). TIRPS quantitatively reproduces the experimental results, including the quasi-parabolic profile observed in the measured CSFs under strong turbulence conditions. Variations in the simulated CSF with ionospheric phase screen parameters are also presented. Under conditions of high integrated strength of turbulence (CkL), a low phase spectral index (p = 1), indicating relatively dense small-scale irregularities, produces pronounced range spreading. Conversely, when the spectral index is high (p = 4), indicative of strong focusing/defocusing by large-scale irregularities, there is increased Doppler spreading and, when the outer scale of irregularities is large, a greater likelihood of asymmetry of the CSF about the zero Doppler axis.

  2. PMSE strength during enhanced D region electron densities: Faraday rotation and absorption effects at VHF frequencies

    Science.gov (United States)

    Chau, Jorge L.; Röttger, Jürgen; Rapp, Markus

    2014-10-01

    In this paper we study the effects of absorption and Faraday rotation on measurements of polar mesosphere summer echoes (PMSE). We found that such effects can produce significant reduction of signal-to-noise ratio (SNR) when the D region electron densities (Ne) are enhanced, and VHF radar systems with linearly polarized antennas are used. In particular we study the expected effects during the strong solar proton event (SPE) of July 2000, also known as the Bastille day flare event. During this event, a strong anti-correlation between the PMSE SNR and the D-region Ne was found over three VHF radar sites at high latitudes: Andøya, Kiruna, and Svalbard. This anti-correlation has been explained (a) in terms of transport effects due to strong electric fields associated to the SPE and (b) due to a limited amount of aerosol particles as compared to the amount of D-region electrons. Our calculations using the Ne profiles used by previous researchers explain most, if not all, of the observed SNR reduction in both time (around the SPE peak) and altitude. This systematic effect, particularly the Faraday rotation, should be recognized and tested, and possibly avoided (e.g., using circular polarization), in future observations during the incoming solar maximum period, to contribute to the understanding of PMSE during enhanced D region Ne.

  3. Microwave Frequency Multiplier

    Science.gov (United States)

    Velazco, J. E.

    2017-02-01

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

  4. Observation Station

    Science.gov (United States)

    Rutherford, Heather

    2011-01-01

    This article describes how a teacher integrates science observations into the writing center. At the observation station, students explore new items with a science theme and use their notes and questions for class writings every day. Students are exposed to a variety of different topics and motivated to write in different styles all while…

  5. Microwave Breast Imaging Techniques

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, Tonny

    2010-01-01

    This paper outlines the applicability of microwave radiation for breast cancer detection. Microwave imaging systems are categorized based on their hardware architecture. The advantages and disadvantages of various imaging techniques are discussed. The fundamental tradeoffs are indicated between...

  6. Molecular Switching in Confined Spaces: Effects of Encapsulating the DHA/VHF Photo-Switch in Cucurbiturils.

    Science.gov (United States)

    Petersen, Michael Å; Rasmussen, Brian; Andersen, Nicolaj N; Sauer, Stephan P A; Nielsen, Mogens Brøndsted; Beeren, Sophie R; Pittelkow, Michael

    2017-09-18

    Confinement of reactive chemical species uniquely affects chemical reactivity by restricting the physical space available and by restricting access to interactions with the solvent. In Nature, for example, confined protein binding pockets govern processes following photoisomerization reactions and the isomerizations themselves. Here we describe the first example of a dihydroazulene/vinylheptafulvene (DHA/VHF) photo-switch functioning in water, and we show how its switching behavior is strongly influenced by supramolecular interactions with a series of cucurbit[n]uril (CB) host molecules. In CB7 inclusion complexes, the kinetics of the thermal VHF-to-DHA back-reaction is accelerated, while in CB8 inclusion complexes, the kinetics is slowed down as compared to the free photo-switch. The effect of the CB encapsulation of the photo-switch can be effectively canceled by introducing a guest that binds the CB more strongly. According to DFT calculations, a stabilization of the reactive s-cis VHF conformer relative to the s-trans VHF appears to be a contributing factor responsible for the accelerated back-reaction when encapsulated in CB7. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Advances in microwaves 7

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 7 covers the developments in the study of microwaves. The book discusses the effect of surface roughness on the propagation of the TEM mode, as well as the voltage breakdown of microwave antennas. The text also describes the theory and design considerations of single slotted-waveguide linear arrays and the techniques and theories that led to the achievement of wide bandwidths and ultralow noise temperatures for communication applications. The book will prove invaluable to microwave engineers.

  8. Nonlinearities in Microwave Superconductivity

    OpenAIRE

    Ledenyov, Dimitri O.; Ledenyov, Viktor O.

    2012-01-01

    The research is focused on the modeling of nonlinear properties of High Temperature Superconducting (HTS) thin films, using Bardeen, Cooper, Schrieffer and Lumped Element Circuit theories, with purpose to enhance microwave power handling capabilities of microwave filters and optimize design of microwave circuits in micro- and nano- electronics.

  9. Microwave processing heats up

    Science.gov (United States)

    Microwaves are a common appliance in many households. In the United States microwave heating is the third most popular domestic heating method food foods. Microwave heating is also a commercial food processing technology that has been applied for cooking, drying, and tempering foods. It's use in ...

  10. Complementary code and digital filtering for detection of weak VHF radar signals from the mesoscale. [SOUSY-VHF radar, Harz Mountains, Germany

    Science.gov (United States)

    Schmidt, G.; Ruster, R.; Czechowsky, P.

    1983-01-01

    The SOUSY-VHF-Radar operates at a frequency of 53.5 MHz in a valley in the Harz mountains, Germany, 90 km from Hanover. The radar controller, which is programmed by a 16-bit computer holds 1024 program steps in core and controls, via 8 channels, the whole radar system: in particular the master oscillator, the transmitter, the transmit-receive-switch, the receiver, the analog to digital converter, and the hardware adder. The high-sensitivity receiver has a dynamic range of 70 dB and a video bandwidth of 1 MHz. Phase coding schemes are applied, in particular for investigations at mesospheric heights, in order to carry out measurements with the maximum duty cycle and the maximum height resolution. The computer takes the data from the adder to store it in magnetic tape or disc. The radar controller is programmed by the computer using simple FORTRAN IV statements. After the program has been loaded and the computer has started the radar controller, it runs automatically, stopping at the program end. In case of errors or failures occurring during the radar operation, the radar controller is shut off caused either by a safety circuit or by a power failure circuit or by a parity check system.

  11. Frequency Reuse, Cell Separation, and Capacity Analysis of VHF Digital Link Mode 3 TDMA

    Science.gov (United States)

    Shamma, Mohammed A.; Nguyen, Thanh C.; Apaza, Rafael D.

    2003-01-01

    The most recent studies by the Federal Aviation Administration (FAA) and the aviation industry have indicated that it has become increasingly difficult to make new VHF frequency or channel assignments to meet the aviation needs for air-ground communications. FAA has planned for several aggressive improvement measures to the existing systems, but these measures would not meet the projected voice communications needs beyond 2009. FAA found that since 1974 there has been, on the average, a 4 percent annual increase in the number of channel assignments needed to satisfy the air-ground communication traffic (approximately 300 new channel assignments per year). With the planned improvement measures, the channel assignments are expected to reach a maximum number of 16615 channels by about 2010. Hence, the FAA proposed the use of VDL Mode 3 as a new integrated digital voice and data communications systems to meet the future air traffic demand. This paper presents analytical results of frequency reuse; cell separation and capacity estimation of VDL Mode 3 TDMA systems that FAA has planned to implement the future VHF air-ground communications system by the year 2010. For TDMA, it is well understood that the frequency reuse factor is a crucial parameter for capacity estimation. Formulation of this frequency reuse factor is shown, taking into account the limitation imposed by the requirement to have a sufficient Signal to Co-Channel Interference Ratio. Several different values for the Signal to Co-Channel Interference Ratio were utilized corresponding to the current analog VHF DSB-AM systems, and the future digital VDL Mode 3. The required separation of Co-Channel cells is computed for most of the Frequency Protected Service Volumes (FPSV's) currently in use by the FAA. Additionally, the ideal cell capacity for each FPSV is presented. Also, using actual traffic for the Detroit air space, a FPSV traffic distribution model is used to generate a typical cell for channel capacity

  12. Layered Polar Mesospheric Summer Echoes Observed with the Tri-Static Eiscat VHF

    Science.gov (United States)

    Mann, I.; Anyairo, C.; Häggström, I.; Tjulin, A.

    2014-12-01

    Polar mesospheric summer echoes (PMSE) are strong radar echoes that are typically observed at 50 to 500 MHz. They are often discussed in the context of dusty plasma studies and linked to e.g. the existence of charged ice particles, neutral atmospheric turbulence and atmospheric stratification. The PMSE are observed at mesospheric temperature minimum when ice particles form, though the exact path of formation is still a topic for research. Mesospheric smoke particles that are assumed to form after or during the meteor ablation process possibly contribute to the formation of the ice particles. For understanding the formation of the radar echoes their variation with scattering angle is an important parameter. We analyze PMSE observations with the tri-static EISCAT VHF radar (224 MHz) during one day in June when PMSE were observed almost continuously from 7:00 to 13:00 UT. The radar signal was transmitted and received in zenith direction with the EISCAT VHF antenna near Tromsø. The receivers in Kiruna and Sodankylä were pointed at typical PMSE heights above the Tromsø transmitter and detected radar reflections at the same time and altitude as the Tromsø radar. The altitude of the PMSE changed with time and the extension of the echoes in altitude was smaller toward the end of the observation. These observations are among the first tri-static observations of PMSE. The observations suggest that the scattering process underlying the PMSE occurs over a broad range of scattering angles. Based on the observations we will show that the spectral width of the received echoes is most likely determined by the variations within the observed volume rather than by the scattering process. The observed frequency shifts suggest a layer structure and horizontal motions that vary with altitude. UHF (933 MHz) radar observations were carried out in parallel, they display predominantly incoherent scatter and an electron density typical for the altitude. Some other studies, have in

  13. F/FB-111 Avionics Test Station and Component Specialist/Technician. Automatic Test Stations Manual and Electronic Warfare Test Stations. Training Requirements Analysis (451X6). Volume 2

    Science.gov (United States)

    1991-11-01

    A ALIGN AN/ALM-204 TEST STATION TRUs (Z1348) A CALIBRATE HPMA (Z1351) A CLEAN CONTACTS (F 210) A ORDER PARTS A REMOVE AND REPLACE COMPONENTS (TASK...MICROWAVE ASSEMBLIES ( HPMA ) 327 TASK : 01130 TASK STKTm2: PERFORM OPERATIONAL TEST OF LRUs THAT RUN ON THE AN/ALM-204 TEST STATION TASK NOTES: LRUu ARE...POWER AMPLIFIER HBR HIGH BAND RECEIVER HDI HORIZONTAL DISPLAY INDICATOR HF HIGH FREQUENCY HFPA HIGH FREQUENCY POWER AMPLIFIER HPMA HIGH POWER MICROWAVE

  14. Medical applications of microwaves

    Science.gov (United States)

    Vrba, Jan; Lapes, M.

    2004-04-01

    Medical applications of microwaves (i.e. a possibility to use microwave energy and/or microwave technique and technology for therapeutical purposes) are a quite new and a very rapidly developing field. Microwave thermotherapy is being used in medicine for the cancer treatment and treatment of some other diseases since early eighties. In this contribution we would like to offer general overview of present activities in the Czech Republic, i.e. clinical applications and results, technical aspects of thermo therapeutic equipment and last but not least, prospective diagnostics based on microwave principals ant technology and instrumentation.

  15. High brightness microwave lamp

    Science.gov (United States)

    Kirkpatrick, Douglas A.; Dolan, James T.; MacLennan, Donald A.; Turner, Brian P.; Simpson, James E.

    2003-09-09

    An electrodeless microwave discharge lamp includes a source of microwave energy, a microwave cavity, a structure configured to transmit the microwave energy from the source to the microwave cavity, a bulb disposed within the microwave cavity, the bulb including a discharge forming fill which emits light when excited by the microwave energy, and a reflector disposed within the microwave cavity, wherein the reflector defines a reflective cavity which encompasses the bulb within its volume and has an inside surface area which is sufficiently less than an inside surface area of the microwave cavity. A portion of the reflector may define a light emitting aperture which extends from a position closely spaced to the bulb to a light transmissive end of the microwave cavity. Preferably, at least a portion of the reflector is spaced from a wall of the microwave cavity. The lamp may be substantially sealed from environmental contamination. The cavity may include a dielectric material is a sufficient amount to require a reduction in the size of the cavity to support the desired resonant mode.

  16. Disturbance-induced responses of VHF and satellite tagged harbour seals

    DEFF Research Database (Denmark)

    Andersen, Signe May; Teilmann, Jonas; Dietz, Rune

    2014-01-01

    ABSTRACT 1. The response of individual harbour seals (Phoca vitulina) to controlled and sporadic disturbances when hauled out in the Anholt seal reserve, Denmark, was studied. Sporadic disturbances from pedestrians, boats, low-flying aeroplanes and grey seals (Halichoerus grypus) were observed...... in or near the reserve. VHF and satellite transmitters were attached to eight harbour seals to determine post-disturbance and undisturbed behaviour during the pre-breeding period (25 April to 21 May 2008). 2. Both disturbed and undisturbed seals mostly returned to the haul-out site from dusk and throughout...... within 40 km from the haul-out site. The maximum extent of post-disturbance trips, however, varied among individuals and disturbance types, and was strongly correlated with the duration of trips. 3. Disturbed and undisturbed seals used the same areas, suggesting that these areas represent normal foraging...

  17. Graphene-based tunable non-foster circuit for VHF applications

    Directory of Open Access Journals (Sweden)

    Jing Tian

    2016-06-01

    Full Text Available This paper presents a negative impedance converter (NIC based on graphene field effect transistors (GFETs for VHF applications. The NIC is designed following Linvill’s open circuit stable (OCS topology. The DC modelling parameters of GFET are extracted from a device measured by Meric et al. [IEEE Electron Devices Meeting, 23.2.1 (2010] Estimated parasitics are also taken into account. Simulation results from Keysight Advanced Design System (ADS show good NIC performance up to 200 MHz and the value of negative capacitance is directly proportional to the capacitive load. In addition, it has been shown that by varying the supply voltage the value of negative capacitance can also be tuned. The NIC stability has been tested up to 2 GHz (10 times the maximum operation frequency using Nyquist stability criterion to ensure there are no oscillation issues.

  18. Simultaneous observation of sporadic E with a rapid-run ionosonde and VHF coherent backscatter radar

    Directory of Open Access Journals (Sweden)

    T. Maruyama

    2006-03-01

    Full Text Available During the SEEK 2 rocket campaign, ionograms were recorded every minute at the Yamagawa Radio Observatory at about 90km west of the region monitored by a VHF (very high frequency coherent backscatter radar. Sporadic E-layer parameters, which include the critical (foEs and blanketing (fbEs frequencies, the layer height (h'Es, and the width of the range spread of sporadic E-traces, were compared with RTI (range-time-intensity plots of VHF quasi-periodic (QP and continuous coherent backscatter echoes. A close relationship was found between the appearance of QP echoes in the RTI plots and the level of spatial inhomogeneity in sporadic E plasma, signified here by the difference between foEs and fbEs. During QP echo events, foEs increased while fbEs decreased, so that the difference foEs-fbEs was enhanced, indicating the development of strong spatial structuring in electron density within a sporadic E-layer. On the other hand, increases in sporadic E range spreading also correlated with the occurrence of QP echoes but the degree of correlation varied from event to event. Continuous radar echoes were observed in association with low altitude sporadic E-layers, located well below 100 km and at times as low as 90 km. During the continuous echo events, both foEs and fbEs were less variable, and the difference foEs-fbEs was small and not as dynamic as in the QP echoes. On the other hand, the Es-layer spread intensified during continuous echoes, which means that some patchiness or corrugation in those low altitude layers is also necessary for the continuous backscatter echoes to take place.

  19. Simultaneous observation of sporadic E with a rapid-run ionosonde and VHF coherent backscatter radar

    Directory of Open Access Journals (Sweden)

    T. Maruyama

    2006-03-01

    Full Text Available During the SEEK 2 rocket campaign, ionograms were recorded every minute at the Yamagawa Radio Observatory at about 90km west of the region monitored by a VHF (very high frequency coherent backscatter radar. Sporadic E-layer parameters, which include the critical (foEs and blanketing (fbEs frequencies, the layer height (h'Es, and the width of the range spread of sporadic E-traces, were compared with RTI (range-time-intensity plots of VHF quasi-periodic (QP and continuous coherent backscatter echoes. A close relationship was found between the appearance of QP echoes in the RTI plots and the level of spatial inhomogeneity in sporadic E plasma, signified here by the difference between foEs and fbEs. During QP echo events, foEs increased while fbEs decreased, so that the difference foEs-fbEs was enhanced, indicating the development of strong spatial structuring in electron density within a sporadic E-layer. On the other hand, increases in sporadic E range spreading also correlated with the occurrence of QP echoes but the degree of correlation varied from event to event. Continuous radar echoes were observed in association with low altitude sporadic E-layers, located well below 100 km and at times as low as 90 km. During the continuous echo events, both foEs and fbEs were less variable, and the difference foEs-fbEs was small and not as dynamic as in the QP echoes. On the other hand, the Es-layer spread intensified during continuous echoes, which means that some patchiness or corrugation in those low altitude layers is also necessary for the continuous backscatter echoes to take place.

  20. Recent Comparisons of VHF Lightning Mapping Using Interferometry and Time-of-Arrival Techniques

    Science.gov (United States)

    Lojou, J.; Cummins, K. L.

    2005-12-01

    As part of Vaisala's technology and applications test bed in the Dallas-Fort Worth area in Texas, we have been operating two overlapping Total Lightning detection networks. One network employs VHF Interferometry (both 2- and 3-timensional instrumentation) and the other employs VHF 3-dimensional Time-Of-Arrival (TOA) techniques. For the first time, these two technologies can be compared and contrasted in a common region where they both exhibit good performance. The aim of the work presented is to evaluate the spatial and temporal "description" of lightning flashes provided by these two techniques, and to compare and contrast the relative strengths of these two approaches for Total Lightning mapping. This study employs data acquired during the summer of 2005. The analysis set includes data obtained by these two networks, as well as cloud-to-ground location data from the U.S. National Lightning Detection Network (NLDN). The spatial extent and vertical profile of sources from individual in-cloud and cloud-to-ground flashes are compared for various storm conditions, with both technologies clearly contributing supplemental information not provided by the other. Leader propagation velocities show a substantially unimodal distribution centered at about 105 m/s for TOA-derived sources, whereas the velocity distribution for sources detected using interferometry exhibit a bimodal distribution with the second mode at about 107 m/s. The most-probable interval-between-sources for TOA-derived sources seems to be a few milliseconds, whereas interferometry produces large populations with intervals near 100 microseconds and 100 milliseconds.

  1. Initial assessment: electromagnetic compatibility aspects of proposed SPS Microwave Power Transmission System (MPTS) operations

    Energy Technology Data Exchange (ETDEWEB)

    1978-02-01

    An analysis of major concerns with regard to the effects on radio and electronic systems by the proposed Microwave Power Transmission System for transmitting power from a satellite solar power station to earth is presented. (LCL)

  2. Using your microwave oven. Lesson 6, Microwave oven management

    OpenAIRE

    Woodard, Janice Emelie, 1929-

    1984-01-01

    Discusses cooking and reheating foods in microwave ovens, and adapting conventional recipes for the microwave. Revised Includes the publication: Adapting conventional recipes to microwave cooking : fact sheet 84 by Janice Woodard, Rebecca Lovingood, R.H. Trice.

  3. Microwave and RF engineering

    CERN Document Server

    Sorrentino, Roberto

    2010-01-01

    An essential text for both students and professionals, combining detailed theory with clear practical guidance This outstanding book explores a large spectrum of topics within microwave and radio frequency (RF) engineering, encompassing electromagnetic theory, microwave circuits and components. It provides thorough descriptions of the most common microwave test instruments and advises on semiconductor device modelling. With examples taken from the authors' own experience, this book also covers:network and signal theory;electronic technology with guided electromagnetic pr

  4. VHF volume-imaging radar observation of aspect-sensitive scatterers tilted in mountain waves above a convective boundary layer

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    2005-06-01

    Full Text Available Thin stable atmospheric layers cause VHF radars to receive increased echo power from near zenith. Layers can be tilted from horizontal, for instance by gravity waves, and the direction of VHF "glinting" is measurable by spatial domain interferometry or many-beam Doppler beam swinging (DBS. This paper uses the Middle and Upper atmosphere (MU radar, Shigaraki, Japan as a volume-imaging radar with 64-beam DBS, to show tilting of layers and air flow in mountain waves. Tilt of aspect-sensitive echo power from horizontal is nearly parallel to air flow, as assumed in earlier measurements of mountain-wave alignment. Vertical-wind measurements are self-consistent from different beam zenith angles, despite the combined effects of aspect sensitivity and horizontal-wind gradients.

  5. Analysis of the VHF-UHF electromagnetic radiation of lightning: Application to a model of the negative stepped leader propagation

    Science.gov (United States)

    Taudiere, Isabelle

    1991-03-01

    The space and time characteristics of the VHF-UHF radiation from lightning are analyzed on the bases of 300 MHz emission sources, localized in three dimensions by interferometric measurements. The main phases that contribute to the development of intracloud lightning are examined in detail, also using electric field measurements at the lower frequency. This research is complemented by an experimental and theoretical analysis of long discharge (8m) radio emissions generated with both polarities in the laboratory. These investigations revealed that the VHF radiation is associated with the channel reillumination phase accompanying each step in the negative spark. The outcome of this work is the creation of a simple model for the propagation of the negative leader. The current and the radiated field during this phase of the discharge are computed from an equivalent electric circuit using the physical laws governing the variation of resistance. The extrapolation of these results to the case of the stepped leader of natural lightning is discussed.

  6. Advanced microwave processing concepts

    Energy Technology Data Exchange (ETDEWEB)

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymeric materials. The variable frequency microwave furnace, whose initial conception and design was funded by the AIM Materials Program, allows the authors, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of various thermoset resins will be studied because it holds the potential of in-situ curing of continuous-fiber composites for strong, lightweight components or in-situ curing of adhesives, including metal-to-metal. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.

  7. Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars

    Directory of Open Access Journals (Sweden)

    A. Westman

    2004-04-01

    Full Text Available Meteor head echo altitude distributions have been derived from data collected with the EISCAT VHF (224MHz and UHF (930MHz high-power, large-aperture (HPLA radars. At the high-altitude end, the distributions cut off abruptly in a manner reminiscent of the trail echo height ceiling effect observed with classical meteor radars. The target dimensions are shown to be much smaller than both the VHF and the UHF probing wavelengths, but the cutoff heights for the two systems are still clearly different, the VHF cutoff being located several km above the UHF one. A single-collision meteor-atmosphere interaction model is used to demonstrate that meteors in the (1.3–7.2µg mass range will ionise such that critical electron density at 224MHz is first reached at or around the VHF cutoff altitude and critical density at 930MHz will be reached at the UHF cutoff altitude. The observed seasonal variation in the cutoff altitudes is shown to be a function of the seasonal variation of atmospheric density with altitude. Assuming that the electron density required for detection is in the order of the critical density, the abrupt altitude cutoffs can be explained as a consequence of the micrometeoroid joint size-speed distribution dropping off so fast at the large-mass, high-velocity end that above a certain altitude the number of detectable events becomes vanishingly small. Conversely, meteors at the low-mass end of the distribution will be gradually retarded such that the ionisation they generate never reaches critical density. These particles will remain unobservable.Key words. Radio science (instruments and techniques – Interplatery physics (interplanetary dust – General or miscellaneous (new fields

  8. VHF digital ultrasound three-dimensional scanning in the diagnosis of myopic regression after corneal refractive surgery.

    Science.gov (United States)

    Reinstein, Dan Z; Ameline, Barbara; Puech, Michel; Montefiore, Guy; Laroche, Laurent

    2005-01-01

    To perform VHF digital ultrasound scanning and analysis of a case of high-myopic undercorrection in an eye that had undergone multiple surgical interventions for the correction of an initial refraction of -12.00 diopters (D). A 49-year-old woman was evaluated after undergoing three surgical interventions for correction of an initial refraction of -12.00 D in the left eye. Automated lamellar keratoplasty (ALK) was followed by arcuate keratotomy (for induced astigmatism) and surface photorefractive keratectomy (PRK). The residual ametropia on presentation was -6.75 -3.50 x 95 degrees. VHF digital ultrasound scanning and analysis was performed. On ultrasound, the ALK interface was clearly visible. Residual stromal thickness beneath the cap was at least 275 microm. The absence of Bowman's layer indicated the region of PRK. New stroma and nascent stromal layers were differentiated within the flap. Neo stromal deposition and central epithelial hyperplasia were determined to be responsible for the myopic shift, as opposed to biomechanical changes. In this case, refraction, slit-lamp examination, and topography were unable to provide a diagnosis for regression following multiple corneal refractive procedures. By providing layered anatomical mapping, VHF digital ultrasound scanning was able to exclude a diagnosis of ectasia and provide anatomical diagnostic information to explain the clinical observations.

  9. Disturbances in VHF/UHF telemetry links as a possible effect of the 2003 Hokkaido Tokachi-oki earthquake

    Directory of Open Access Journals (Sweden)

    H. Nagamoto

    2008-08-01

    Full Text Available The data on radio telemetry links (for water information at VHF/UHF in Hokkaido are used to investigate the rate of disturbances on radio links (or connection failure and its association with a huge earthquake, Tokachi-oki earthquake on 26 September 2003. Especially, the telemetry links at the Tokachi region closest to the earthquake epicenter, showed a significant increase in disturbances on radio links two weeks to a few days before the earthquake on the basis of analysis during a long interval from 1 June 2002 to 3 November 2007 (over 5 years. We suggest that these severe disturbances in VHF/UHF telemetry links are attributed to the generation of seismogenic VHF/UHF radio noises (emissions. Based on this idea, we have estimated that the intensity of these seismogenic emissions is on the order of 10–19 dB μV/m. Finally, the present result was compared with other physical parameters already obtained for this earthquake.

  10. First results from an iron lidar and a VHF radar at Davis, Antarctica

    Science.gov (United States)

    Luebken, F.; Morris, R. J.; Hoeffner, J.; Kaifler, B.; Viehl, T.

    2012-12-01

    We present temperature measurements at Davis, Antarctica (69°S, 78°E), and compare with simultaneous and co-located radar measurements of polar mesosphere summer echoes (PMSE). The mobile scanning iron lidar of the IAP in Kuehlungsborn was installed at Davis in December 2010. It measures iron densities, vertical winds, and temperatures in the iron layer, i. e. from approximately 80 to 100 km. It is based on probing the Doppler broadened resonance line of iron atoms at 386 nm and can operate under daylight conditions. Typical values for temperature uncertainty, altitude and time resolution are 3-5 K, 1 km, and 1 hour, respectively. The lidar also measures neutral air densities and temperatures in the stratosphere and lower mesosphere. At Davis the lidar has up to now achieved approximately 2700 hours of data which is presumably the largest nearly continuous data set in Antarctica. The mesopause altitude changes throughout the summer season by several kilometers, significantly different from the northern hemisphere summer. Depending on altitude, temperatures can be warmer or colder compared to the NH summer. Temperatures at Davis near 86 km are rather similar to the NH, but they are much colder at higher altitudes. The thermal structure around the mesopause at Davis is closely related to the general circulation in the stratosphere, namely to the transition from winter to summer conditions. Different from expectations we sometimes find the mesopause significantly higher and colder(!) compared to the NH. Furthermore, we find large thermal tides in the summer months with amplitudes of up to 6-7~K, which is much larger than expected from models. The Australien Antarctic Division operates a 55 MHz VHF radar at Davis since February 2003. We report first simultaneous measurements of PMSE and temperatures by the Fe lidar. PMSE are strong radar echoes related to ice particles and therefore require atmospheric temperatures being lower than the frost point temperature

  11. Integrated microwave photonics

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.; Heideman, Rene; Leinse, Arne; Sales, S.; Capmany, J.

    2013-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A

  12. Microwave hydrology: A trilogy

    Science.gov (United States)

    Stacey, J. M.; Johnston, E. J.; Girard, M. A.; Regusters, H. A.

    1985-01-01

    Microwave hydrology, as the term in construed in this trilogy, deals with the investigation of important hydrological features on the Earth's surface as they are remotely, and passively, sensed by orbiting microwave receivers. Microwave wavelengths penetrate clouds, foliage, ground cover, and soil, in varying degrees, and reveal the occurrence of standing liquid water on and beneath the surface. The manifestation of liquid water appearing on or near the surface is reported by a microwave receiver as a signal with a low flux level, or, equivalently, a cold temperature. Actually, the surface of the liquid water reflects the low flux level from the cosmic background into the input terminals of the receiver. This trilogy describes and shows by microwave flux images: the hydrological features that sustain Lake Baykal as an extraordinary freshwater resource; manifestations of subsurface water in Iran; and the major water features of the Congo Basin, a rain forest.

  13. Long-period unstable gravity-waves and associated VHF radar echoes

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    Full Text Available VHF atmospheric radar is used to measure the wind velocity and radar echo power related to long-period wind perturbations, including gravity waves, which are observed commonly in the lower stratosphere and tropopause region, and sometimes in the troposphere. These wind structures have been identified previously as either inertia-gravity waves, often associated with jet streams, or mountain waves. At heights of peak wind shear, imbalances are found between the echo powers of a symmetric pair of radar beams, which are expected to be equal. The largest of these power differences are found for conditions of simultaneous high wind shear and high aspect sensitivity. It is suggested that the effect might arise from tilted specular reflectors or anisotropic turbulent scatterers, a result of, for example, Kelvin-Helmholtz instabilities generated by the strong wind shears. This radar power-difference effect could offer information about the onset of saturation in long-period waves, and the formation of thin layers of turbulence.

  14. Anisotropy of Doppler spectral parameters in the VHF radar observations at MU and White Sands

    Directory of Open Access Journals (Sweden)

    G. D. Nastrom

    2001-08-01

    Full Text Available Significant differences are found between the mean spectral widths from beams in the meridional plane and in the zonal plane at both the MU and the White Sands VHF radars. The spectral width in the beam directed perpendicular to the prevailing wind is greater than that in the beam parallel to the wind. The magnitudes of the differences in spectral width show a linear relationship with wind speed, with the greatest differences at the greatest wind speeds. The differences in spectral width show a positive correlation with the differences in backscattered power. The anisotropy in backscattered power is well-known and is usually attributed to aspect sensitivity effects. However, the anisotropy in spectral width does not appear to be due to the same mechanism, and while several hypotheses to account for this are considered, including finite range-volume effects, effects from the tilting of isentropic layers, and anisotropic turbulence effects, it is seen that each of these suggestions has its shortcomings.Key words. Meteorology and atmospheric dynamics (turbulence; instruments and techniques

  15. Anisotropy of Doppler spectral parameters in the VHF radar observations at MU and White Sands

    Directory of Open Access Journals (Sweden)

    G. D. Nastrom

    Full Text Available Significant differences are found between the mean spectral widths from beams in the meridional plane and in the zonal plane at both the MU and the White Sands VHF radars. The spectral width in the beam directed perpendicular to the prevailing wind is greater than that in the beam parallel to the wind. The magnitudes of the differences in spectral width show a linear relationship with wind speed, with the greatest differences at the greatest wind speeds. The differences in spectral width show a positive correlation with the differences in backscattered power. The anisotropy in backscattered power is well-known and is usually attributed to aspect sensitivity effects. However, the anisotropy in spectral width does not appear to be due to the same mechanism, and while several hypotheses to account for this are considered, including finite range-volume effects, effects from the tilting of isentropic layers, and anisotropic turbulence effects, it is seen that each of these suggestions has its shortcomings.

    Key words. Meteorology and atmospheric dynamics (turbulence; instruments and techniques

  16. Range imaging observations of PMSE using the EISCAT VHF radar: Phase calibration and first results

    Directory of Open Access Journals (Sweden)

    J. R. Fernandez

    2005-01-01

    Full Text Available A novel phase calibration technique for use with the multiple-frequency Range IMaging (RIM technique is introduced based on genetic algorithms. The method is used on data collected with the European Incoherent SCATter (EISCAT VHF radar during a 2002 experiment with the goal of characterizing the vertical structure of Polar Mesosphere Summer Echoes (PMSE over northern Norway. For typical Doppler measurements, the initial phases of the transmitter and receiver are not required to be the same. The EISCAT receiver systems exploit this fact, allowing a multi-static configuration. However, the RIM method relies on the small phase differences between closely spaced frequencies. As a result, the high-resolution images produced by the RIM method can be significantly degraded if not properly calibrated. Using an enhanced numerical radar simulator, in which data from multiple sampling volumes are simultaneously generated, the proposed calibration method is validated. Subsequently, the method is applied to preliminary data from the EISCAT radar, providing first results of RIM images of PMSE. Data using conventional analysis techniques, and confirmed by RIM, reveal an often-observed double-layer structure with higher stability in the lower layer. Moreover, vertical velocity oscillations exhibit a clear correlation with the apparent motion of the layers shown in the echo power plots.

  17. Frequency domain interferometry mode observations of PMSE using the EISCAT VHF radar

    Directory of Open Access Journals (Sweden)

    P. B. Chilson

    2000-12-01

    Full Text Available During the summer of 1997 investigations into the nature of polar mesosphere summer echoes (PMSE were conducted using the European incoherent scatter (EISCAT VHF radar in Norway. The radar was operated in a frequency domain interferometry (FDI mode over a period of two weeks to study the frequency coherence of the returned radar signals. The operating frequencies of the radar were 224.0 and 224.6 MHz. We present the first results from the experiment by discussing two 4-h intervals of data collected over two consecutive nights. During the first of the two days an enhancement of the FDI coherence, which indicates the presence of distinct scattering layers, was found to follow the lower boundary of the PMSE. Indeed, it is not unusual to observe that the coherence values are peaked around the heights corresponding to both the lower- and upper-most boundaries of the PMSE layer and sublayers. A Kelvin-Helmholtz mechanism is offered as one possible explanation for the layering structure. Additionally, our analysis using range-time-pseudocolor plots of signal-to-noise ratios, spectrograms of Doppler velocity, and estimates of the positions of individual scattering layers is shown to be consistent with the proposition that upwardly propagating gravity waves can become steepened near the mesopause.Key words: Ionosphere (polar ionosphere · Meteorology and Atmospheric Dynamics (middle atmosphere dynamics · Radio Science (Interferometry

  18. Frequency domain interferometry mode observations of PMSE using the EISCAT VHF radar

    Directory of Open Access Journals (Sweden)

    P. B. Chilson

    Full Text Available During the summer of 1997 investigations into the nature of polar mesosphere summer echoes (PMSE were conducted using the European incoherent scatter (EISCAT VHF radar in Norway. The radar was operated in a frequency domain interferometry (FDI mode over a period of two weeks to study the frequency coherence of the returned radar signals. The operating frequencies of the radar were 224.0 and 224.6 MHz. We present the first results from the experiment by discussing two 4-h intervals of data collected over two consecutive nights. During the first of the two days an enhancement of the FDI coherence, which indicates the presence of distinct scattering layers, was found to follow the lower boundary of the PMSE. Indeed, it is not unusual to observe that the coherence values are peaked around the heights corresponding to both the lower- and upper-most boundaries of the PMSE layer and sublayers. A Kelvin-Helmholtz mechanism is offered as one possible explanation for the layering structure. Additionally, our analysis using range-time-pseudocolor plots of signal-to-noise ratios, spectrograms of Doppler velocity, and estimates of the positions of individual scattering layers is shown to be consistent with the proposition that upwardly propagating gravity waves can become steepened near the mesopause.

    Key words: Ionosphere (polar ionosphere · Meteorology and Atmospheric Dynamics (middle atmosphere dynamics · Radio Science (Interferometry

  19. Study of CNT growth using nanocatalyst Ag precursor by HWC-VHF-PECVD

    Energy Technology Data Exchange (ETDEWEB)

    Eliyana, Ajeng; Rosikin, Ahmad; Winata, Toto, E-mail: toto@fi.itb.ac.id [Physics of Electronics Material Research Division, Physics Programme, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132, West Java (Indonesia)

    2015-04-16

    The study of CNT growth has been done by using silver (Ag) nanocatalyst as a guide precursor on corning glass 7059 substrate. The silver catalyst was prepared by the evaporation method by varying deposition time for 50, 25, and 14 seconds. The silver films were then annealed at temperature of 400°C for 4 hours. From Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) results the grain sizes are 65 nm, 57 nm, and 33 nm, and also the atomic compositions are 6,06%, 4,52%, and 3,73% for 14, 25 and 50 seconds samples, respectively. The 33 nm samples were then used for CNT growth by using Hot Wire Cell (HWC) – Very High Frequency (VHF) – Plasma Enhanced Chemical Vapor Deposition (PECVD) at 275 ° C deposition temperature and pressure of 300 mTorr. The rf power was varied from 8 to 20 watts, with deposition time for 60 minutes. The methane (CH4) 99.999% was used as Carbon sources. Hydrogen gas (H2) was used to etch the oxide layer formed during the pre-deposition process. The diameter and length for the CNT are 125 nm and 1.650 to 2.989 nm respectively.

  20. On the VHF source retrieval errors associated with Lightning Mapping Arrays (LMAs)

    Science.gov (United States)

    Koshak, W. J.

    2016-12-01

    A common method for retrieving the lightning Very High Frequency (VHF) radio source (x, y, z, t) emission is to minimize a (reduced) chi-squared function that indicates how well the model arrival times associated with the model source represent the arrival time measurements at each Lightning Mapping Array (LMA) site. The Levenberg-Marquardt (LM) algorithm is usually employed to find the minimum of the chi-squared function, and the model source producing this minimum is considered to be the optimal source solution. Because the chi-squared mathematical surface is nonlinear, it is important to feed the LM algorithm an accurate initial guess (xo, yo, zo, to) in parameter space to avoid parameter searches that terminate at a relative minima of the chi-squared surface. Source initialization is commonly performed using a linear retrieval algorithm first introduced in Koshak and Solakiewicz (1996), and further applied in Koshak et al. (2004). Monte Carlo simulations and theoretical inferences both show that source retrieval errors (particularly source altitude errors) increase with horizontal source range. In the present study, the effect of modifying certain elements of the retrieval (i. e., the LMA site locations, the number of sites employed, and the retrieval algorithm characteristics) are examined to assess and quantify associated improvements in retrieval results.

  1. Signal processing techniques for phase-coded HF-VHF radars

    Directory of Open Access Journals (Sweden)

    J. A. Baskaradas

    2003-06-01

    Full Text Available HF-VHF radar techniques are easy to employ and commonly used in geophysical applications. They include deep radio soundings, used for probing the ionosphere, stratosphere-mesosphere measurement, weather forecast and radio-glaciology. Fast algorithms and powerful processors facilitate the development of several kinds of low power radars, but the reduction of the transmitted power has to be compensated by on-line processing of an encoded signal to maintain a favorable signal-to-noise ratio suitable for detection. Moreover, radars have to reconstruct return echoes with different travel times due to various origins (multi-path, adjacent objects, etc.. Such needs can be accomplished by means of signal phase coding and one of the most attractive is the reversal phase code. The composite echo signal must be processed to extract the physical information useful for the measurement considered. In this paper some algorithms used for on-line processing of phase-coded signals will be described, both in time and frequency domain.

  2. Environmental assessment: South microwave communication facilities

    Energy Technology Data Exchange (ETDEWEB)

    1989-06-01

    Western Area Power Administration (Western) is proposing to construct, operate, and maintain eight microwave repeater stations in southwestern Colorado, southeastern Utah, and northern Arizona, in order to meet the minimum fade criteria established by the Western Systems Coordinating Council (WSCC) for the operation and protection of electric power systems. The proposed microwave facilities would increase the reliability of communication. This environmental assessment (EA) describes the existing environmental conditions and the impacts from construction of the eight microwave communication facilities. The EA was prepared in compliance with the National Environmental Policy Act of 1969, the Council on Environmental Quality Regulations (40 CFR 1500-1508), and the Department of Energy Guidelines (52 FR 47662, December 15, 1987). The proposed project would consist of constructing eight microwave facilities, each of which would include a self-supported lattice tower, an equipment building, a propane tank, distribution lines to provide electric power to the sites, and access roads to the sites. The facilities would be constructed in San Miguel and Montezuma Counties in Colorado, San Juan County, Utah, and Navajo, Apache, Coconino, and Yavapai Counties in Arizona. 20 refs., 2 figs., 2 tabs.

  3. Linked Station Neighbors

    Data.gov (United States)

    Federal Communications Commission — This file that is a subset of the Linked-Station Set file. This file specifies, for each U.S. or impeding Canadian station part of a linked station set, the set of...

  4. Gold Nanoparticle Microwave Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  5. Advances in microwaves 4

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 4 covers some innovations in the devices and applications of microwaves. This volume contains three chapters and begins with a discussion of the application of microwave phasers and time delay elements as beam steering elements in array radars. The next chapter provides first an overview of the technical aspects and different types of millimeter waveguides, followed by a survey of their application to railroads. The last chapter examines the general mode of conversion properties of nonuniform waveguides, such as waveguide tapers, using converted Maxwell's equatio

  6. Microwave coupler and method

    Science.gov (United States)

    Holcombe, C. E.

    1984-11-01

    The present invention is directed to a microwave coupler for enhancing the heating or metallurgical treatment of materials within a cold-wall, rapidly heated cavity as provided by a microwave furnace. The coupling material of the present invention is an alpha-rhombohedral-boron-derivative-structure material such as boron carbide or boron silicide which can be appropriately positioned as a susceptor within the furnace to heat other material or be in powder particulate form so that composites and structures of boron carbide such as cutting tools, grinding wheels and the like can be rapidly and efficiently formed within microwave furnaces.

  7. Advances in microwaves

    CERN Document Server

    Young, Leo

    1967-01-01

    Advances in Microwaves, Volume 2 focuses on the developments in microwave solid-state devices and circuits. This volume contains six chapters that also describe the design and applications of diplexers and multiplexers. The first chapter deals with the parameters of the tunnel diode, oscillators, amplifiers and frequency converter, followed by a simple physical description and the basic operating principles of the solid state devices currently capable of generating coherent microwave power, including transistors, harmonic generators, and tunnel, avalanche transit time, and diodes. The next ch

  8. Emitron: microwave diode

    Science.gov (United States)

    Craig, G.D.; Pettibone, J.S.; Drobot, A.T.

    1982-05-06

    The invention comprises a new class of device, driven by electron or other charged particle flow, for producing coherent microwaves by utilizing the interaction of electromagnetic waves with electron flow in diodes not requiring an external magnetic field. Anode and cathode surfaces are electrically charged with respect to one another by electron flow, for example caused by a Marx bank voltage source or by other charged particle flow, for example by a high energy charged particle beam. This produces an electric field which stimulates an emitted electron beam to flow in the anode-cathode region. The emitted electrons are accelerated by the electric field and coherent microwaves are produced by the three dimensional spatial and temporal interaction of the accelerated electrons with geometrically allowed microwave modes which results in the bunching of the electrons and the pumping of at least one dominant microwave mode.

  9. Microwave Oven Observations.

    Science.gov (United States)

    Sumrall, William J.; Richardson, Denise; Yan, Yuan

    1998-01-01

    Explains a series of laboratory activities which employ a microwave oven to help students understand word problems that relate to states of matter, collect data, and calculate and compare electrical costs to heat energy costs. (DDR)

  10. Microwave Service Towers

    Data.gov (United States)

    Department of Homeland Security — This file is an extract of the Universal Licensing System (ULS) licensed by the Wireless Telecommunications Bureau (WTB). It consists of Microwave Transmitters (see...

  11. The Cosmic Microwave Background

    Science.gov (United States)

    Pierpaoli, E.

    2011-03-01

    In these lectures I present the physical aspects of the Cosmic Microwave Background primary and secondary anisotropies; the characteristics of the CMB power spectra and their dependence on cosmological parameters. I also discuss the observational status and future perspectives.

  12. Effect of solar and magnetic activity on VHF scintillations near the equatorial anomaly crest

    Directory of Open Access Journals (Sweden)

    R. P. Singh

    2004-09-01

    Full Text Available The VHF amplitude scintillation recorded during the period January 1991 to December 1993 in the declining phase of a solar cycle and April 1998 to December 1999 in the ascending phase of the next solar cycle at Varanasi (geogr. lat.=25.3°, long.=83.0°, dip=37°N have been analyzed to study the behavior of ionospheric irregularities during active solar periods and magnetic storms. It is shown that irregularities occur at arbitrary times and may last for <30min. A rise in solar activity increases scintillations during winter (November-February and near equinoxes (March-April; September-October, whereas it depresses the scintillations during the summer (May-July. In general, the role of magnetic activity is to suppress scintillations in the pre-midnight period and to increase it in the post-midnight period during equinox and winter seasons, whilst during summer months the effect is reversed. The pre-midnight scintillation is sometimes observed when the main phase of Dst corresponds to the pre-midnight period. The annual variation shows suppression of scintillations on disturbed days, both during pre-midnight and post-midnight period, which becomes more effective during years of high solar activity. It is observed that for magnetic storms for which the recovery phase starts post-midnight, the probability of occurrence of irregularities is enhanced during this time. If the magnetic storm occurred during daytime, then the probability of occurrence of scintillations during the night hours is decreased. The penetration of magnetospheric electric fields to the magnetic equator affects the evolution of low-latitude irregularities. A delayed disturbance dynamo electric field also affects the development of irregularities.

  13. Simulation of Controller Pilot Data Link Communications over VHF Digital Link Mode 3

    Science.gov (United States)

    Bretmersky, Steven C.; Murawski, Robert; Nguyen, Thanh C.; Raghavan, Rajesh S.

    2004-01-01

    The Federal Aviation Administration (FAA) has established an operational plan for the future Air Traffic Management (ATM) system, in which the Controller Pilot Data Link Communications (CPDLC) is envisioned to evolve into digital messaging that will take on an ever increasing role in controller to pilot communications, significantly changing the way the National Airspace System (NAS) is operating. According to FAA, CPDLC represents the first phase of the transition from the current analog voice system to an International Civil Aviation Organization (ICAO) compliant system in which digital communication becomes the alternate and perhaps primary method of routine communication. The CPDLC application is an Air Traffic Service (ATS) application in which pilots and controllers exchange messages via an addressed data link. CPDLC includes a set of clearance, information, and request message elements that correspond to existing phraseology employed by current Air Traffic Control (ATC) procedures. These message elements encompass altitude assignments, crossing constraints, lateral deviations, route changes and clearances, speed assignments, radio frequency assignments, and various requests for information. The pilot is provided with the capability to respond to messages, to request clearances and information, to report information, and to declare/rescind an emergency. A 'free text' capability is also provided to exchange information not conforming to defined formats. This paper presents simulated results of the aeronautical telecommunication application Controller Pilot Data Link Communications over VHF Digital Link Mode 3 (VDL Mode 3). The objective of this simulation study was to determine the impact of CPDLC traffic loads, in terms of timely message delivery and capacity of the VDL Mode 3 subnetwork. The traffic model is based on and is used for generating air/ground messages with different priorities. Communication is modeled for the en route domain of the Cleveland

  14. Seasonal and diurnal changes in wind variability from Flatland VHF profiler observations

    Energy Technology Data Exchange (ETDEWEB)

    Nastrom, G.D. [Saint Cloud State Univ., MN (United States). Dept. of Earth Sci.; Clark, W.L. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Aeronomy Lab.; Zandt, T.E. van [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Aeronomy Lab.; Warnock, J.M. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Aeronomy Lab.

    1996-02-01

    Climatological results are presented on the hourly variance of the wind observed in the mid-troposphere (3 to 9 km MSL). This quantity roughly indicates the energy in the atmospheric wind field for variations with periods roughly less than 1 hour. Observations are from the Flatland VHF research wind profiler, located near Champaign/Urbana, Illinois, well away from significant orographic features. The period of record covers two years, September 1990 through August 1992. The values of the variance of the winds along vertical and oblique (15 degrees from zenith in the cardinal directions) beams are presented versus height, season, time-of-day, and beam pointing direction. It is found that the hourly variance values have approximately lognormal frequency distribution. The mean hourly variance is significantly larger for the oblique wind observations than for the vertical. Mean wind variances also tend to be larger in the east/west steering plane than in the north/south plane. The mean variance generally increases with height, but faster than would be expected if it were due solely to the decrease in atmospheric density, implying the presence of local source/sinks of wind energy. The rate of change with height is noticeably different for the vertical and oblique beams, being much less for the vertical beam, in some seasons even decreasing with height. With respect to season, the mean hourly variance is smallest in the summer and largest in the winter. With respect to diurnal changes, the variance is maximum during the afternoon for spring, summer, and autumn, with the maximum up to a factor of two larger than the minimum. In winter, the diurnal change is much smaller, with little indication of an afternoon maximum. (orig.)

  15. VHF radar observations of turbulent structures in the polar mesopause region

    Directory of Open Access Journals (Sweden)

    P. Czechowsky

    Full Text Available The mobile SOUSY VHF Radar was operated in the summer of 1987 during the MAC/SINE campaign in northern Norway to study the polar mesosphere summer echoes (PMSE. Measurements of the spectral width indicate that two types of structures occur. In general mesospheric layers are bifurcated exhibiting a narrow spectral width and a well-defined aspect sensitivity. However, for about 10% of the observation time cells of enhanced turbulence characterized by extremely broad spectral widths appear predominantly in the upper sublayer above 86 km. Identification and separation of beam and shear broadening allows a determination of the turbulence-induced component of the spectral width. This case study reveals that during several events these cloud-like structures of enhanced turbulence move with an apparent velocity of several tens of meters per second which is almost identical with the phase trace velocity of simultaneously observed waves. Since, at that time, the Richardson number was less than a quarter, it was concluded that these turbulent cells were generated by a Kelvin-Helmholtz mechanism. The horizontal extent of these structures was calculated to be less than 40 km. A general relation between spectral width and echo power was not detected. The turbulent component of the spectral width was used to calculate typical values of the energy dissipation rate at times where narrow spectral width dominates and during periods of enhanced turbulence. In addition, the outer scale of the inertial subrange (buoyancy scale was estimated. For the first time the occurrence and motion of this type of structures of enhanced spectral width is analyzed and discussed in detail.

  16. VHF radar observations of turbulent structures in the polar mesopause region

    Directory of Open Access Journals (Sweden)

    P. Czechowsky

    1997-08-01

    Full Text Available The mobile SOUSY VHF Radar was operated in the summer of 1987 during the MAC/SINE campaign in northern Norway to study the polar mesosphere summer echoes (PMSE. Measurements of the spectral width indicate that two types of structures occur. In general mesospheric layers are bifurcated exhibiting a narrow spectral width and a well-defined aspect sensitivity. However, for about 10% of the observation time cells of enhanced turbulence characterized by extremely broad spectral widths appear predominantly in the upper sublayer above 86 km. Identification and separation of beam and shear broadening allows a determination of the turbulence-induced component of the spectral width. This case study reveals that during several events these cloud-like structures of enhanced turbulence move with an apparent velocity of several tens of meters per second which is almost identical with the phase trace velocity of simultaneously observed waves. Since, at that time, the Richardson number was less than a quarter, it was concluded that these turbulent cells were generated by a Kelvin-Helmholtz mechanism. The horizontal extent of these structures was calculated to be less than 40 km. A general relation between spectral width and echo power was not detected. The turbulent component of the spectral width was used to calculate typical values of the energy dissipation rate at times where narrow spectral width dominates and during periods of enhanced turbulence. In addition, the outer scale of the inertial subrange (buoyancy scale was estimated. For the first time the occurrence and motion of this type of structures of enhanced spectral width is analyzed and discussed in detail.

  17. The relationship between VHF radar auroral backscatter amplitude and Doppler velocity: a statistical study

    Directory of Open Access Journals (Sweden)

    B. A. Shand

    1996-08-01

    Full Text Available A statistical investigation of the relationship between VHF radar auroral backscatter intensity and Doppler velocity has been undertaken with data collected from 8 years operation of the Wick site of the Sweden And Britain Radar-auroral Experiment (SABRE. The results indicate three different regimes within the statistical data set; firstly, for Doppler velocities <200 m s–1, the backscatter intensity (measured in decibels remains relatively constant. Secondly, a linear relationship is observed between the backscatter intensity (in decibels and Doppler velocity for velocities between 200 m s–1 and 700 m s–1. At velocities greater than 700 m s–1 the backscatter intensity saturates at a maximum value as the Doppler velocity increases. There are three possible geophysical mechanisms for the saturation in the backscatter intensity at high phase speeds: a saturation in the irregularity turbulence level, a maximisation of the scattering volume, and a modification of the local ambient electron density. There is also a difference in the dependence of the backscatter intensity on Doppler velocity for the flow towards and away from the radar. The results for flow towards the radar exhibit a consistent relationship between backscatter intensity and measured velocities throughout the solar cycle. For flow away from the radar, however, the relationship between backscatter intensity and Doppler velocity varies during the solar cycle. The geometry of the SABRE system ensures that flow towards the radar is predominantly associated with the eastward electrojet, and flow away is associated with the westward electrojet. The difference in the backscatter intensity variation as a function of Doppler velocity is attributed to asymmetries between the eastward and westward electrojets and the geophysical parameters controlling the backscatter amplitude.

  18. Statistics of 150-km echoes over Jicamarca based on low-power VHF observations

    Directory of Open Access Journals (Sweden)

    J. L. Chau

    2006-07-01

    Full Text Available In this work we summarize the statistics of the so-called 150-km echoes obtained with a low-power VHF radar operation at the Jicamarca Radio Observatory (11.97 S, 76.87 W, and 1.3 dip angle at 150-km altitude in Peru. Our results are based on almost four years of observations between August 2001 and July 2005 (approximately 150 days per year. The majority of the observations have been conducted between 08:00 and 17:00 LT. We present the statistics of occurrence of the echoes for each of the four seasons as a function of time of day and altitude. The occurrence frequency of the echoes is ~75% around noon and start decreasing after 15:00 LT and disappear after 17:00 LT in all seasons. As shown in previous campaign observations, the 150-echoes appear at a higher altitude (>150 km in narrow layers in the morning, reaching lower altitudes (~135 km around noon, and disappear at higher altitudes (>150 km after 17:00 LT. We show that although 150-km echoes are observed all year long, they exhibit a clear seasonal variability on altitudinal coverage and the percentage of occurrence around noon and early in the morning. We also show that there is a strong day-to-day variability, and no correlation with magnetic activity. Although our results do not solve the 150-km riddle, they should be taken into account when a reasonable theory is proposed.

  19. The relationship between VHF radar auroral backscatter amplitude and Doppler velocity: a statistical study

    Directory of Open Access Journals (Sweden)

    B. A. Shand

    Full Text Available A statistical investigation of the relationship between VHF radar auroral backscatter intensity and Doppler velocity has been undertaken with data collected from 8 years operation of the Wick site of the Sweden And Britain Radar-auroral Experiment (SABRE. The results indicate three different regimes within the statistical data set; firstly, for Doppler velocities <200 m s–1, the backscatter intensity (measured in decibels remains relatively constant. Secondly, a linear relationship is observed between the backscatter intensity (in decibels and Doppler velocity for velocities between 200 m s–1 and 700 m s–1. At velocities greater than 700 m s–1 the backscatter intensity saturates at a maximum value as the Doppler velocity increases. There are three possible geophysical mechanisms for the saturation in the backscatter intensity at high phase speeds: a saturation in the irregularity turbulence level, a maximisation of the scattering volume, and a modification of the local ambient electron density. There is also a difference in the dependence of the backscatter intensity on Doppler velocity for the flow towards and away from the radar. The results for flow towards the radar exhibit a consistent relationship between backscatter intensity and measured velocities throughout the solar cycle. For flow away from the radar, however, the relationship between backscatter intensity and Doppler velocity varies during the solar cycle. The geometry of the SABRE system ensures that flow towards the radar is predominantly associated with the eastward electrojet, and flow away is associated with the westward electrojet. The difference in the backscatter intensity variation as a function of Doppler velocity is attributed to asymmetries between the eastward and westward electrojets and the geophysical parameters controlling the backscatter amplitude.

  20. Cut-off low monitoring by the French VHF-ST-radar network during the ESTIME campaign

    Science.gov (United States)

    Caccia, J.-L.; Bertin, F.; Campistron, B.; Klaus, V.; Pointin, Y.; van Baelen, J.; Wilson, R.

    2000-05-01

    In order to investigate mesoscale strato-tropospheric exchanges, the field campaign `Echanges Stratosphère-Troposphère: Investigations à Moyenne Echelle' was conducted in France from late 1993 to mid 1995 and focused on cut-off low events. It involved the French research network of five VHF (Very High Frequency) ST (Strato-Tropospheric) radars deployed in southern France. Observations corresponding to three Intensive Observing Periods are reported here. The radar data analyzed and discussed are time-height diagrams of the aspect ratio (AR), that is, the vertical to oblique beam-returned power ratio, used for monitoring three cut-off low events. In order to discuss the validity of the method, 506 h of radar AR data were compared with time-height diagrams of the static stability and the humidity obtained from synoptic European Center for Medium-range Weather Forecasts model analyses. A dataset corresponding to 297 h of observations is analyzed and discussed here. It is concluded that the AR is a good tracer to document cut-off low events, including tropopause folding identification and the detection of tropospheric air masses of enhanced stability, in dry or weakly humid cases. On the other hand, although the effects of the specific humidity and its gradients on VHF radar echo power could not be extensively investigated, our results suggest that the same parameter cannot be used at mid- and lower-tropospheric levels when the effects of specific humidity significantly reinforce the moist static stability. It is important to take into account these insights in the context of future observing campaigns in which a network of VHF-ST-radars will be involved, and where their role will be to observe and to document the evolution of upper-level features or potential vorticity streamers, or more generally stratospheric-tropospheric exchanges.

  1. Microwave system engineering principles

    CERN Document Server

    Raff, Samuel J

    1977-01-01

    Microwave System Engineering Principles focuses on the calculus, differential equations, and transforms of microwave systems. This book discusses the basic nature and principles that can be derived from thermal noise; statistical concepts and binomial distribution; incoherent signal processing; basic properties of antennas; and beam widths and useful approximations. The fundamentals of propagation; LaPlace's Equation and Transmission Line (TEM) waves; interfaces between homogeneous media; modulation, bandwidth, and noise; and communications satellites are also deliberated in this text. This bo

  2. Microwave Processing of Materials

    Science.gov (United States)

    1994-01-01

    reactions in sol-gel processing, gas-phase synthesis , solution evaporation/decomposition, or hydrothermal reactions. Each of these, and other powder... synthesis methods, will be described next. Sol-Gel Decomposition/Drying Microwaves have been used in several of the processing stages to synthesize BaTiO3 ...high surface areas (10-700 m2/g). Hydrothermal Reactions Microwave- hydrothermal processing has been utilized in catalyzing the synthesis of crystalline

  3. A microwave powered sensor assembly for microwave ovens

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a microwave powered sensor assembly for micro- wave ovens. The microwave powered sensor assembly comprises a microwave antenna for generating an RF antenna signal in response to microwave radiation at a predetermined excitation frequency. A dc power supply circuit...... in a microwave oven chamber....... of the microwave powered sensor assembly is operatively coupled to the RF antenna signal for extracting energy from the RF antenna signal and produce a power supply voltage. A sensor is connected to the power supply voltage and configured to measure a physical or chemical property of a food item under heating...

  4. Microwave Plasma Hydrogen Recovery System

    Science.gov (United States)

    Atwater, James; Wheeler, Richard, Jr.; Dahl, Roger; Hadley, Neal

    2010-01-01

    A microwave plasma reactor was developed for the recovery of hydrogen contained within waste methane produced by Carbon Dioxide Reduction Assembly (CRA), which reclaims oxygen from CO2. Since half of the H2 reductant used by the CRA is lost as CH4, the ability to reclaim this valuable resource will simplify supply logistics for longterm manned missions. Microwave plasmas provide an extreme thermal environment within a very small and precisely controlled region of space, resulting in very high energy densities at low overall power, and thus can drive high-temperature reactions using equipment that is smaller, lighter, and less power-consuming than traditional fixed-bed and fluidized-bed catalytic reactors. The high energy density provides an economical means to conduct endothermic reactions that become thermodynamically favorable only at very high temperatures. Microwave plasma methods were developed for the effective recovery of H2 using two primary reaction schemes: (1) methane pyrolysis to H2 and solid-phase carbon, and (2) methane oligomerization to H2 and acetylene. While the carbon problem is substantially reduced using plasma methods, it is not completely eliminated. For this reason, advanced methods were developed to promote CH4 oligomerization, which recovers a maximum of 75 percent of the H2 content of methane in a single reactor pass, and virtually eliminates the carbon problem. These methods were embodied in a prototype H2 recovery system capable of sustained high-efficiency operation. NASA can incorporate the innovation into flight hardware systems for deployment in support of future long-duration exploration objectives such as a Space Station retrofit, Lunar outpost, Mars transit, or Mars base. The primary application will be for the recovery of hydrogen lost in the Sabatier process for CO2 reduction to produce water in Exploration Life Support systems. Secondarily, this process may also be used in conjunction with a Sabatier reactor employed to

  5. Lightning VHF radiation location system based on short-baseline TDOA technique — Validation in rocket-triggered lightning

    Science.gov (United States)

    Sun, Zhuling; Qie, Xiushu; Liu, Mingyuan; Cao, Dongjie; Wang, Dongfang

    2013-07-01

    A lightning VHF radiation location system based on short-baseline time-difference of arrival (TDOA) technology is newly developed. Based on the orthogonal 10 m-baseline antenna array with four identical broadband flat plane antennas, this system receives the lightning broadband VHF radiation signals and calculates TDOA between antennas in order to determine the location of lightning radiation sources in two dimensions (elevation and azimuth). To reduce noise and improve estimation accuracy of time delay, a general correlation time delay estimation algorithm based on direct correlation method and wavelet transform is proposed. Moreover, parabolic interpolation algorithm is used in the fractional delay estimation to improve the time resolution of the positioning system. In this paper, a rocket-triggered lightning discharge and a cloud lightning discharge are analyzed respectively, combining with simultaneous observations of high-speed camera and fast/slow electric field changes. The results indicate that the TDOA location system could effectively map the lightning radiation sources in 2 dimensions and are in a good agreement with the high-speed video camera images.

  6. Radar efficiency and the calculation of decade-long PMSE backscatter cross-section for the Resolute Bay VHF radar

    Directory of Open Access Journals (Sweden)

    N. Swarnalingam

    2009-04-01

    Full Text Available The Resolute Bay VHF radar, located in Nunavut, Canada (75.0° N, 95.0° W and operating at 51.5 MHz, has been used to investigate Polar Mesosphere Summer Echoes (PMSE since 1997. PMSE are a unique form of strong coherent radar echoes, and their understanding has been a challenge to the scientific community since their discovery more than three decades ago. While other high latitude radars have recorded strong levels of PMSE activities, the Resolute Bay radar has observed relatively lower levels of PMSE strengths. In order to derive absolute measurements of PMSE strength at this site, a technique is developed to determine the radar efficiency using cosmic (sky noise variations along with the help of a calibrated noise source. VHF radars are only rarely calibrated, but determination of efficiency is even less common. Here we emphasize the importance of efficiency for determination of cross-section measurements. The significant advantage of this method is that it can be directly applied to any MST radar system anywhere in the world as long as the sky noise variations are known. The radar efficiencies for two on-site radars at Resolute Bay are determined. PMSE backscatter cross-section is estimated, and decade-long PMSE strength variations at this location are investigated. It was noticed that the median of the backscatter cross-section distribution remains relatively unchanged, but over the years a great level of variability occurs in the high power tail of the distribution.

  7. Meteoroid Fragmentation as Revealed in Head- and Trail-Echoes Observed with the Arecibo UHF and VHF Radars

    Science.gov (United States)

    Mathews, J. D.; Malhorta, A.

    2011-01-01

    We report recent 46.8/430 MHz (VHF/UHF) radar meteor observations at Arecibo Observatory (AO) that reveal many previously unreported features in the radar meteor return - including flare-trails at both UHF and VHF - that are consistent with meteoroid fragmentation. Signature features of fragmentation include strong intra-pulse and pulse-to-pulse fading as the result of interference between or among multiple meteor head-echo returns and between head-echo and impulsive flare or "point" trail-echoes. That strong interference fading occurs implies that these scatterers exhibit well defined phase centers and are thus small compared with the wavelength. These results are consistent with and offer advances beyond a long history of optical and radar meteoroid fragmentation studies. Further, at AO, fragmenting and flare events are found to be a large fraction of the total events even though these meteoroids are likely the smallest observed by the major radars. Fragmentation is found to be a major though not dominate component of the meteors observed at other HPLA radars that are sensitive to larger meteoroids.

  8. Microwave engineering concepts and fundamentals

    CERN Document Server

    Khan, Ahmad Shahid

    2014-01-01

    Detailing the active and passive aspects of microwaves, Microwave Engineering: Concepts and Fundamentals covers everything from wave propagation to reflection and refraction, guided waves, and transmission lines, providing a comprehensive understanding of the underlying principles at the core of microwave engineering. This encyclopedic text not only encompasses nearly all facets of microwave engineering, but also gives all topics—including microwave generation, measurement, and processing—equal emphasis. Packed with illustrations to aid in comprehension, the book: •Describes the mathematical theory of waveguides and ferrite devices, devoting an entire chapter to the Smith chart and its applications •Discusses different types of microwave components, antennas, tubes, transistors, diodes, and parametric devices •Examines various attributes of cavity resonators, semiconductor and RF/microwave devices, and microwave integrated circuits •Addresses scattering parameters and their properties, as well a...

  9. A semiconductor nanowire Josephson junction microwave laser

    Science.gov (United States)

    Cassidy, Maja; Uilhoorn, Willemijn; Kroll, James; de Jong, Damaz; van Woerkom, David; Nygard, Jesper; Krogstrup, Peter; Kouwenhoven, Leo

    We present measurements of microwave lasing from a single Al/InAs/Al nanowire Josephson junction strongly coupled to a high quality factor superconducting cavity. Application of a DC bias voltage to the Josephson junction results in photon emission into the cavity when the bias voltage is equal to a multiple of the cavity frequency. At large voltage biases, the strong non-linearity of the circuit allows for efficient down conversion of high frequency microwave photons down to multiple photons at the fundamental frequency of the cavity. In this regime, the emission linewidth narrows significantly below the bare cavity linewidth to threshold lasing with a power conversion efficiency > 50%. The junction-cavity coupling and laser emission can be tuned rapidly via an external gate, making it suitable to be integrated into a scalable qubit architecture as a versatile source of coherent microwave radiation. This work has been supported by the Netherlands Organisation for Scientific Research (NWO/OCW), Foundation for Fundamental Research on Matter (FOM), European Research Council (ERC), and Microsoft Corporation Station Q.

  10. Vortices at Microwave Frequencies

    Science.gov (United States)

    Silva, Enrico; Pompeo, Nicola; Dobrovolskiy, Oleksandr V.

    2017-11-01

    The behavior of vortices at microwave frequencies is an extremely useful source of information on the microscopic parameters that enter the description of the vortex dynamics. This feature has acquired particular relevance since the discovery of unusual superconductors, such as cuprates. Microwave investigation then extended its field of application to many families of superconductors, including the artificially nanostructured materials. It is then important to understand the basics of the physics of vortices moving at high frequency, as well as to understand what information the experiments can yield (and what they can not). The aim of this brief review is to introduce the readers to some basic aspects of the physics of vortices under a microwave electromagnetic field, and to guide them to an understanding of the experiment, also by means of the illustration of some relevant results.

  11. Physics of the Microwave Oven

    Science.gov (United States)

    Vollmer, Michael

    2004-01-01

    This is the first of two articles about the physics of microwave ovens. This article deals with the generation of microwaves in the oven and includes the operation of the magnetrons, waveguides and standing waves in resonant cavities. It then considers the absorption of microwaves by foods, discussing the dielectric relaxation of water,…

  12. High-Rate Fabrication of a-Si-Based Thin-Film Solar Cells Using Large-Area VHF PECVD Processes

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Xunming [University of Toledo; Fan, Qi Hua

    2011-12-31

    The University of Toledo (UT), working in concert with it’s a-Si-based PV industry partner Xunlight Corporation (Xunlight), has conducted a comprehensive study to develop a large-area (3ft x 3ft) VHF PECVD system for high rate uniform fabrication of silicon absorber layers, and the large-area VHF PECVD processes to achieve high performance a-Si/a-SiGe or a-Si/nc-Si tandem junction solar cells during the period of July 1, 2008 to Dec. 31, 2011, under DOE Award No. DE-FG36-08GO18073. The project had two primary goals: (i) to develop and improve a large area (3 ft × 3 ft) VHF PECVD system for high rate fabrication of > = 8 Å/s a-Si and >= 20 Å/s nc-Si or 4 Å/s a-SiGe absorber layers with high uniformity in film thicknesses and in material structures. (ii) to develop and optimize the large-area VHF PECVD processes to achieve high-performance a-Si/nc-Si or a-Si/a-SiGe tandem-junction solar cells with >= 10% stable efficiency. Our work has met the goals and is summarized in “Accomplishments versus goals and objectives”.

  13. Water Level Station History

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Images contain station history information for 175 stations in the National Water Level Observation Network (NWLON). The NWLON is a network of long-term,...

  14. Fire Stations - 2009

    Data.gov (United States)

    Kansas Data Access and Support Center — Fire Stations in Kansas Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their jobs is...

  15. Hammond Bay Biological Station

    Data.gov (United States)

    Federal Laboratory Consortium — Hammond Bay Biological Station (HBBS), located near Millersburg, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). HBBS was established by...

  16. Weather Radar Stations

    Data.gov (United States)

    Department of Homeland Security — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  17. Fire Stations - 2007

    Data.gov (United States)

    Kansas Data Access and Support Center — Fire Station Locations in Kansas Any location where fire fighters are stationed at or based out of, or where equipment that such personnel use in carrying out their...

  18. Streamflow Gaging Stations

    Data.gov (United States)

    Department of Homeland Security — This map layer shows selected streamflow gaging stations of the United States, Puerto Rico, and the U.S. Virgin Islands, in 2013. Gaging stations, or gages, measure...

  19. Newport Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Newport Research Station is the Center's only ocean-port research facility. This station is located at Oregon State University's Hatfield Marine Science Center,...

  20. Big Game Reporting Stations

    Data.gov (United States)

    Vermont Center for Geographic Information — Point locations of big game reporting stations. Big game reporting stations are places where hunters can legally report harvested deer, bear, or turkey. These are...

  1. Reference Climatological Stations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Reference Climatological Stations (RCS) network represents the first effort by NOAA to create and maintain a nationwide network of stations located only in areas...

  2. Fundamentals of microwave photonics

    CERN Document Server

    Urick, V J; McKinney , Jason D

    2015-01-01

    A comprehensive resource to designing andconstructing analog photonic links capable of high RFperformanceFundamentals of Microwave Photonics provides acomprehensive description of analog optical links from basicprinciples to applications.  The book is organized into fourparts. The first begins with a historical perspective of microwavephotonics, listing the advantages of fiber optic links anddelineating analog vs. digital links. The second section coversbasic principles associated with microwave photonics in both the RFand optical domains.  The third focuses on analog modulationformats-starti

  3. Microwave circulator design

    CERN Document Server

    Linkhart, Douglas K

    2014-01-01

    Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.

  4. Application of Ground Based Microwave Radiometry for Characterizing Tropical Convection

    Science.gov (United States)

    Renju, R.; Raju, C. S.

    2016-12-01

    The characterization of the microphysical and thermodynamical properties of convective events over the tropical coastal station Thiruvananthapuram (TVM, 8.5o N 76.9oE) has been carried out by utilizing multiyear Microwave Radiometer Profiler (MRP) observations. The analyses have been extended to develop a methodology to identify convective events, based on the radiometric brightness temperature (Tb) differences, at 30 GHz and 22.5 GHz channels and are compared using reflectivity and rainfall intensity deduced from concurrent and collocated disdrometer measurements. In all 84 such convections were identified using the above methodology over the station for a period of years, 2010-2013; both during pre- and post- Indian summer monsoon months and further evaluated by computing their stability indices. The occurrence of convection over this coastal station peaks in the afternoon and early morning hours with genesis, respectively, over the land and the sea. The number of occurrence of convective events are less during monsoon deficit year whereas strong and more during heavy monsoon rainfall year. These findings are further evaluated with the percentage occurrence of fractional convective clouds derived from microwave payload SAPHIR observations on Megha-Tropique satellite. Based on the analyses the frequency of occurrence of convection can be related to the monsoonal rainfall obtaining over the region. The analyses also indicate that the microwave radiometric brightness temperature of humidity channels depicts the type of convection and respond two hours prior to the occurrence of rainfall. In addition to that the multi-angle observations of microwave radiometer profiler have been utilized to study the propagation of convective systems. This study and the methodology developed for identifying convection have significance in microwave (Ka- and W-band) satellite propagation characterization since convection and precipitation are the major hindrance to satellite

  5. Microwave extraction of bioactive compounds

    Directory of Open Access Journals (Sweden)

    Monika Blekić

    2011-01-01

    Full Text Available Microwave extraction presents novel extraction and treatment method for food processing. In paper, several examples of microwave extraction of bioactive compounds are presented. Also, novel innovative equipment for microwave extraction and hydrodiffusion with gravitation is presented. Advantage of using novel equipment for microwave extraction is shown, and it include, shorter treatment time, less usage or without any solvent use. Novel method is compared to standard extraction methods. Some positive and negative aspects of microwave heating can be observed, and also its influence on development of oxidation in sunflower oil subjected to microwave heating. Also, use of microwaves for the extraction of essential oils is shown. One can also see the advantages of solvent-free microwave extraction of essential oil from aromatic herbs in comparison with the standard extraction, and determination of antioxidant components in rice bran oil extracted by microwave-assisted method. Comparison of microwave and ultrasound extraction, as well as positive and negative aspects of the combination of microwaves and ultrasound is described.

  6. Passive and active RF-microwave circuits course and exercises with solutions

    CERN Document Server

    Jarry, Pierre

    2015-01-01

    Microwave and radiofrequency (RF) circuits play an important role in communication systems. Due to the proliferation of radar, satellite, and mobile wireless systems, there is a need for design methods that can satisfy the ever increasing demand for accuracy, reliability, and fast development times. This book explores the principal elements for receiving and emitting signals between Earth stations, satellites, and RF (mobile phones) in four parts; the theory and realization of couplers, computation and realization of microwave and RF filters, amplifiers and microwave and RF oscillators. Pas

  7. Leakage of Microwave Ovens

    Science.gov (United States)

    Abdul-Razzaq, W.; Bushey, R.; Winn, G.

    2011-01-01

    Physics is essential for students who want to succeed in science and engineering. Excitement and interest in the content matter contribute to enhancing this success. We have developed a laboratory experiment that takes advantage of microwave ovens to demonstrate important physical concepts and increase interest in physics. This experiment…

  8. Microwave Assisted Drug Delivery

    DEFF Research Database (Denmark)

    Jónasson, Sævar Þór; Zhurbenko, Vitaliy; Johansen, Tom Keinicke

    2014-01-01

    In this work, the microwave radiation is adopted for remote activation of pharmaceutical drug capsules inside the human body in order to release drugs at a pre-determined time and location. An array of controllable transmitting sources is used to produce a constructive interference at a certain f...

  9. Nonlinear Microwave Optomechanics

    NARCIS (Netherlands)

    Shevchuk, O.

    2017-01-01

    The nonlinearity is essential for creation of non-classical states of the cavity or mechanical resonator such as squeezed or cat states. A microwave cavity can be made nonlinear by, for instance, adding Josephson junctions. The mechanical resonator is inherently nonlinear. The radiation pressure

  10. INTERACT Station Catalogue - 2015

    DEFF Research Database (Denmark)

    INTERACT stations are located in all major environmental envelopes of the Arctic providing an ideal platform for studying climate change and its impact on the environment and local communities. Since alpine environments face similar changes and challenges as the Arctic, the INTERACT network also...... includes some alpine stations located outside the Arctic. The INTERACT research stations provide an ideal platform for circumarctic research and monitoring. Activities span from small short term research projects to larger long term monitoring programmes. The stations are thus visited by many researchers...... and research groups. Therefore, INTERACT has produced a catalogue of research stations including descriptions of the physical setting, facilities and services offered at the stations. It is our hope that this catalogue will help researchers identify research stations that suit their specific needs. The 2015...

  11. Microwave Power Beaming Infrastructure for Manned Lightcraft Operations: Part 2

    Science.gov (United States)

    Myrabo, Leik N.

    2008-04-01

    In the past ˜7 years, microwave gyrotron technology has rapidly evolved to a critical threshold wherein ultra-energetic space launch missions based on beamed energy propulsion (BEP) now appear eminently feasible. Over the next 20 years, hundred megawatt-class microwave power-beaming stations could be prototyped on high deserts and 3- to 4 km mountain peaks before migrating into low Earth orbit, along with their passive microwave relay satellites. Described herein is a 20 GW rechargeable nuclear power satellite and microwave power-beaming infrastructure designed for manned space launch operations in the year 2025. The technological readiness of 2500 GJ superconducting magnetic energy storage "batteries," 433-m ultralight space structures, 100 MW liquid droplet radiators, 1-6+ MW gyrotron sources, and mega-scale arrays (e.g., 3000 phase-locked units) is addressed. Microwave BEP is "breakthrough" technology with the very real potential to radically reduce space access costs by factors of 100 to 1000 in the forseeable future.

  12. Amtrak Rail Stations (National)

    Data.gov (United States)

    Department of Transportation — Updated database of the Federal Railroad Administration's (FRA) Amtrak Station database. This database is a geographic data set containing Amtrak intercity railroad...

  13. Space Station operations

    Science.gov (United States)

    Gray, R. H.

    1985-01-01

    An evaluation of the success of the Space Station will be based on the service provided to the customers by the Station crew, the productivity of the crew, and the costs of operation. Attention is given to details regarding Space Station operations, a summary of operational philosophies and requirements, logistics and resupply operations, prelaunch processing and launch operations, on-orbit operations, aspects of maintainability and maintenance, habitability, and questions of medical care. A logistics module concept is considered along with a logistics module processing timeline, a habitability module concept, and a Space Station rescue mission.

  14. Hekinan thermal power station

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    Hekinan thermal power station is situated at the port of Kinuura in Aichi Prefecture, Japan. Unit 1 began commercial operation in October 1991, Unit 2 in June 1992 and Unit 3 in April 1993. This brochure gives the specification of the main facilities of the power station, shows its layout; illustrates its pollution control equipment, gives specifications of its flue gas treatment systems and of its large steam turbine, describes its coal handling facilities and gives their specifications, and mentions the power station`s automated control system.

  15. Cooperative Station History Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various forms, photographs and correspondence documenting the history of Cooperative station instrumentation, location changes, inspections, and...

  16. Cosmic Microwave Background Anisotropies

    OpenAIRE

    Hu, Wayne; Dodelson,Scott

    2001-01-01

    Cosmic microwave background (CMB) temperature anisotropies have and will continue to revolutionize our understanding of cosmology. The recent discovery of the previously predicted acoustic peaks in the power spectrum has established a working cosmological model: a critical density universe consisting of mainly dark matter and dark energy, which formed its structure through gravitational instability from quantum fluctuations during an inflationary epoch. Future observations should test this mo...

  17. Microwave susceptibility experiments

    Energy Technology Data Exchange (ETDEWEB)

    McConaghy, C.

    1984-05-29

    In certain experimental environments, systems can be affected or damaged by microwave pulses. I have conducted tests at LLNL to understand the phenomenology of microwave susceptibility of system components and subsystem components. To date, my experiments have concentrated on bipolar transistors, similar to what might be used in discrete analog circuits, and on CMOS RAM chips, which might be used in a computer memory system. I observed a decrease in failure energies for both the transistor and the integrated curcuit as I shortened the microwave pulse width. An S band (2.86 GHz) transmit/receive (T/R) tube has also been tested both at S band and at X band (8.16 GHz). The S band pulse had limitations in rise-time from zero power, which had an effect on the amount of power that could be transmitted through the T/R tube, as much as 0.7% of the incident power passed through the tube. All tests were conducted in closed-waveguide or coax test-fixtures, in contrast to the anechoic chambers utilized by other experimenters. I have used both S band and X band Klystron generators. For very high power (greater than 1 MW), I used an additional pulse-compression cavity at S band. Other subsystem components such as an X band mixer and an X band T/R tube will be tested in the future. 8 references.

  18. Microwave-Assisted Olefin Metathesis

    Science.gov (United States)

    Nicks, François; Borguet, Yannick; Sauvage, Xavier; Bicchielli, Dario; Delfosse, Sébastien; Delaude, Lionel; Demonceau, Albert

    Since the first reports on the use of microwave irradiation to accelerate organic chemical transformations, a plethora of papers have been published in this field. In most examples, microwave heating has been shown to dramatically reduce reaction times, increase product yields, and enhance product purity by reducing unwanted side reactions compared to conventional heating methods. The present contribution aims at illustrating the advantages of this technology in olefin metathesis and, when data are available, at comparing microwave-heated and conventionally heated experiments

  19. Introduction to Microwave Linear [Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Whittum, David H

    1999-01-04

    The elements of microwave linear accelerators are introduced starting with the principles of acceleration and accelerating structures. Considerations for microwave structure modeling and design are developed from an elementary point of view. Basic elements of microwave electronics are described for application to the accelerator circuit and instrumentation. Concepts of beam physics are explored together with examples of common beamline instruments. Charged particle optics and lattice diagnostics are introduced. Considerations for fixed-target and colliding-beam experimentation are summarized.

  20. Radar observations of ionospheric irregularities at Syowa Station, Antarctica: a brief overview

    Directory of Open Access Journals (Sweden)

    T. Ogawa

    1996-12-01

    Full Text Available We briefly overview the radar observations that have been made for 30 years at Syowa Station, Antarctica for studying small-scale electron-density irregularities in the southern high-latitude E- and F-region ionosphere. Some observational results (i.e., long-term variations of radio aurora, Doppler spectra with narrow spectral widths and low Doppler velocities, and simultaneous observations of radar and optical auroras from VHF radars capable of detecting 1.3- to 3-m scale irregularities are presented. A new 50-MHz radar system equipped with phased-antenna arrays began operation in February 1995 to observe two-dimensional behaviours of E-region irregularities. An HF radar experiment also began in February 1995 to explore decameter-scale E- and F-region irregularities in the auroral zone and polar cap. These two radars will contribute to a better understanding of the ionospheric irregularities and ionospheric physics at southern high latitudes.

  1. An introduction to microwave measurements

    CERN Document Server

    Basu, Ananjan

    2014-01-01

    IntroductionAim and ScopeGeneral Electronic Measurements and Frequency LimitationsApplications and Importance of Microwave MeasurementsOverview of State-of-the-Art Microwave MeasurementsReferencesBackground InformationS-Parameters and Related Black-Box RepresentationSpectra of Commonly Encountered SignalsMicrowave Filters and Directional CouplersMicrowave Mixers, Switches, Attenuators, and ConnectorsConclusionProblemsReferencesTraditional Measurement TechniquesThe Power MeterTransmission MeasurementReflection MeasurementConclusionProblemsReferencesVector Network AnalyzerEnhancement of Scalar M

  2. The Microwave SQUID Multiplexer

    Science.gov (United States)

    Mates, John Arthur Benson

    2011-12-01

    This thesis describes a multiplexer of Superconducting Quantum Interference Devices (SQUIDs) with low-noise, ultra-low power dissipation, and great scalability. The multiplexer circuit measures the magnetic flux in a large number of unshunted rf SQUIDs by coupling each SQUID to a superconducting microwave resonator tuned to a unique resonance frequency and driving the resonators from a common feedline. A superposition of microwave tones measures each SQUID simultaneously using only two coaxial cables between the cryogenic device and room temperature. This multiplexer will enable the instrumentation of arrays with hundreds of thousands of low-temperature detectors for new applications in cosmology, materials analysis, and nuclear non-proliferation. The driving application of the Microwave SQUID Multiplexer is the readout of large arrays of superconducting transition-edge sensors, by some figures of merit the most sensitive detectors of electromagnetic signals over a span of more than nine orders of magnitude in energy, from 40 GHz microwaves to 200 keV gamma rays. Modern transition-edge sensors have noise-equivalent power as low as 10-20 W / Hz1/2 and energy resolution as good as 2 eV at 6 keV. These per-pixel sensitivities approach theoretical limits set by the underlying signals, motivating a rapid increase in pixel count to access new science. Compelling applications, like the non-destructive assay of nuclear material for treaty verification or the search for primordial gravity waves from inflation use arrays of these detectors to increase collection area or tile a focal plane. We developed three generations of SQUID multiplexers, optimizing the first for flux noise 0.17 muPhi0 / Hz1/2, the second for input current noise 19 pA / Hz1/2, and the last for practical multiplexing of large arrays of cosmic microwave background polarimeters based on transition-edge sensors. Using the last design we demonstrated multiplexed readout of prototype polarimeters with the

  3. Non-Ionizing Radiation Used in Microwave Ovens

    Science.gov (United States)

    ... in Microwave Ovens Non-Ionizing Radiation Used in Microwave Ovens Explore the interactive, virtual community of RadTown USA ! ... learn more About Non-Ionizing Radiation Used in Microwave Ovens Microwave Oven. Microwave ovens use electromagnetic waves that ...

  4. First simultaneous lidar observations of sodium layers and VHF radar observations of E-region field-aligned irregularities at the low-latitude station Gadanki

    Directory of Open Access Journals (Sweden)

    S. Sridharan

    2009-09-01

    Full Text Available Simultaneous observations of atmospheric sodium (Na made by a resonance lidar and E-region field-aligned-irregularities (FAI made by the Indian MST radar, both located at Gadanki (13.5° N, 79.2° E and horizontal winds acquired by a SKiYMET meteor radar at Trivandrum (8.5° N, 77° E are used to investigate the relationship among sodium layer, FAI and neutral winds in the mesosphere and lower thermosphere region. The altitudes and descent rates of higher altitude (~95 km Na layer and FAI agree quite well. The descending structures of the higher altitude Na layer and FAI are found to be closely related to the diurnal tidal phase structure in zonal winds observed over Trivandrum. At lower altitudes, the descent rate of FAI is larger than that of Na layer and zonal tidal phase. These observations support the hypothesis that the metallic ion layers are formed by the zonal wind shear associated with tidal winds and subsequently get neutralized to manifest in the form of descending Na layers. The descending FAI echoing layers are manifestation of the instabilities setting in on the ionization layer. In the present observations, the altitudes of occurrence of Na layer and FAI echoes being low, we surmise that it is quite possible that the FAI echoes are due to the descent of already formed irregularities at higher altitudes.

  5. Secure base stations

    NARCIS (Netherlands)

    Bosch, Peter; Brusilovsky, Alec; McLellan, Rae; Mullender, Sape J.; Polakos, Paul

    2009-01-01

    With the introduction of the third generation (3G) Universal Mobile Telecommunications System (UMTS) base station router (BSR) and fourth generation (4G) base stations, such as the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Evolved Node B (eNB), it has become important to

  6. Station Climatic Summaries, Asia

    Science.gov (United States)

    1989-07-01

    274 MALAYSIA SINGAPORE APRT 486940 8505 (OCDS) ................................................... 278 NORTH KOREA CHANGJON/ONSEIRI 470610 6809 (CB...526 BURSA 171160 8709 (OCDS) ................................................... 528 CIGLI/IZMIR 172180...SUMMARY * STATION: SINGAPORE AIRPORT, MALAYSIA STATION #: 486940 ICAO ID: WSSS LOCATION: 01022N, 10400E ELEVATION (FEET): 21 LST - GMT +8 PREPARED BY

  7. "Inventive" Learning Stations

    Science.gov (United States)

    Jarrett, Olga

    2010-01-01

    Learning stations can be used for myriad purposes--to teach concepts, integrate subject matter, build interest, and allow for inquiry--the possibilities are limited only by the imagination of the teacher and the supplies available. In this article, the author shares suggestions and a checklist for setting up successful learning stations. In…

  8. SPS rectifier stations

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The first of the twelves SPS rectifier stations for the bending magnets arrived at CERN at the end of the year. The photograph shows a station with the rectifiers on the left and in the other three cubicles the chokes, capacitors and resistor of the passive filter.

  9. Central Station Design Options

    DEFF Research Database (Denmark)

    2011-01-01

    . The work identifies the architecture, sizing and siting of prospective Central Stations in Denmark, which can be located at shopping centers, large car parking lots or gas stations. Central Stations are planned to be integrated in the Danish distribution grid. The Danish island of Bornholm, where a high...... penetration of wind power is present, is considered as special case. The distribution grid in Denmark is built using larger secondary distribution transformers (e.g. 630 kVA) which in general allows higher flexibility for the installation of Central Stations, compared to Bornholm’s distribution grid...... kWh battery-EV is not feasible in Bornholm at the 0.4 kV level, due to predominantly small size secondary distribution transformers, in the range of 100 - 200 kVA. This is possible at the 10kV level (MV level), if the Fast Charging station is equipped with its own dedicated transformer. With DC...

  10. [STEM on Station Education

    Science.gov (United States)

    Lundebjerg, Kristen

    2016-01-01

    The STEM on Station team is part of Education which is part of the External Relations organization (ERO). ERO has traditional goals based around BHAG (Big Hairy Audacious Goal). The BHAG model is simplified to a saying: Everything we do stimulates actions by others to advance human space exploration. The STEM on Station education initiate is a project focused on bringing off the earth research and learning into classrooms. Educational resources such as lesson plans, activities to connect with the space station and STEM related contests are available and hosted by the STEM on Station team along with their partners such as Texas Instruments. These educational activities engage teachers and students in the current happenings aboard the international space station, inspiring the next generation of space explorers.

  11. Capacity at Railway Stations

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    special focus when conducting UIC 406 capacity analyses.This paper describes how the UIC 406 capacity method can be expounded for stations. Commonly for the analyses of the stations it is recommended to include the entire station including the switch zone(s) and all station tracks. By including the switch...... zone(s) the possible conflicts with other trains (also in the opposite direction) are taken into account leading to more trustworthy results. Although the UIC 406 methodology proposes that the railway network should be divided into line sections when trains turn around and when the train order...... is changed, this paper recommends that the railway lines are not always be divided. In case trains turn around on open (single track) line, the capacity consumption may be too low if a railway line is divided. The same can be the case if only few trains are overtaken at an overtaking station. For dead end...

  12. The Epi Info Viral Hemorrhagic Fever (VHF) Application: A Resource for Outbreak Data Management and Contact Tracing in the 2014-2016 West Africa Ebola Epidemic.

    Science.gov (United States)

    Schafer, Ilana J; Knudsen, Erik; McNamara, Lucy A; Agnihotri, Sachin; Rollin, Pierre E; Islam, Asad

    2016-10-15

    The Epi Info Viral Hemorrhagic Fever application (Epi Info VHF) was developed in response to challenges managing outbreak data during four 2012 filovirus outbreaks. Development goals included combining case and contact data in a relational database, facilitating data-driven contact tracing, and improving outbreak data consistency and use. The application was first deployed in Guinea, when the West Africa Ebola epidemic was detected, in March 2014, and has been used in 7 African countries and 2 US states. Epi Info VHF enabled reporting of compatible data from multiple countries, contributing to international Ebola knowledge. However, challenges were encountered in accommodating the epidemic's unexpectedly large magnitude, addressing country-specific needs within 1 software product, and using the application in settings with limited Internet access and information technology support. Use of Epi Info VHF in the West Africa Ebola epidemic highlighted the fundamental importance of good data management for effective outbreak response, regardless of the software used. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  13. More Experiments with Microwave Ovens

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter; Karstadt, Detlef

    2004-01-01

    Microwave ovens can be used to perform exciting demonstrations that illustrate a variety of physics topics. Experiments discussed here show superheating, visualize the inhomogeneous heating that takes place in a microwave and also show how to use a mobile phone to detect radiation leaking from the oven. Finally eggs can give some spectacular…

  14. PROGRAMMING THE MICROWAVE-OVEN

    NARCIS (Netherlands)

    KOK, LP; VISSER, PE; BOON, ME

    1994-01-01

    Microwaves can be used to stimulate chemical bonding, diffusion of reagents into and out of the specimen, and coagulation processes in preparatory techniques. Temperature plays an important role in these processes. There are several ways of controlling the temperature of microwave-exposed tissue,

  15. Microwave drying of wood strands

    Science.gov (United States)

    Guanben Du; Siqun Wang; Zhiyong Cai

    2005-01-01

    Characteristics of microwave drying of wood strands with different initial moisture contents and geometries were investigated using a commercial small microwave oven under different power inputs. Temperature and moisture changes along with the drying efficiency were examined at different drying scenarios. Extractives were analyzed using gas chromatography=mass...

  16. Computer-Generated Microwave Holograms.

    Science.gov (United States)

    Leming, Charles W.; Hastings, Orestes Patterson, III

    1980-01-01

    Described is the phasor method of superposition of waves. The intensity pattern from a system of microwave sources is calculated point by point on a plane corresponding to a film emulsion, and then printed and directly converted to a hologram for 3-cm microwaves. Calculations, construction, and viewing of holograms are included. (Author/DS)

  17. Advances on integrated microwave photonics

    DEFF Research Database (Denmark)

    Dong, Jianji; Liao, Shasha; Yan, Siqi

    2017-01-01

    Integrated microwave photonics has attracted a lot of attentions and makes significant improvement in last 10 years. We have proposed and demonstrated several schemes about microwave photonics including waveform generation, signal processing and energy-efficient micro-heaters. Our schemes are all...... fabricated on silicon-on-insulator chips and have advantages of compactness and capability to integrate with electronics....

  18. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    Microwave band gap structures exhibit certain stop band characteristics based on the periodicity, impedance contrast and effective refractive index contrast. These structures though formed in one-, two- and three-dimensional periodicity, are huge in size. In this paper, microstrip-based microwave band gap structures are ...

  19. Microwave and Pulsed Power

    Energy Technology Data Exchange (ETDEWEB)

    Freytag, E.K.

    1993-03-01

    The goals of the Microwave and Pulsed Power thrust area are to identify realizable research and development efforts and to conduct high-quality research in those pulse power and microwave technologies that support existing and emerging programmatic requirements at Lawrence Livermore National Laboratory (LLNL). Our main objective is to work on nationally important problems while enhancing our basic understanding of enabling technologies such as component design and testing, compact systems packaging, exploratory physics experiments, and advanced systems integration and performance. During FY-92, we concentrated our research efforts on the six project areas described in this report. (1) We are investigating the superior electronic and thermal properties of diamond that may make it an ideal material for a high-power, solid-state switch. (2) We are studying the feasibility of using advanced Ground Penetrating Imaging Radar technology for reliable non-destructive evaluation of bridges and other high-value concrete structures. These studies include conceptual designs, modeling, experimental verifications, and image reconstruction of simulated radar data. (3) We are exploring the efficiency of pulsed plasma processing techniques used for the removal of NO{sub x} from various effluent sources. (4) We have finished the investigation of the properties of a magnetically delayed low-pressure gas switch, which was designed here at LLNL. (5) We are applying statistical electromagnetic theory techniques to help assess microwave effects on electronic subsystems, by using a mode stirred chamber as our measurement tool. (6) We are investigating the generation of perfluoroisobutylene (PFIB) in proposed CFC replacement fluids when they are subjected to high electrical stresses and breakdown environments.

  20. Statistical characteristics of low-latitude ionospheric field-aligned irregularities obtained with the Piura VHF radar

    Directory of Open Access Journals (Sweden)

    J. L. Chau

    2002-08-01

    Full Text Available We present a summary of the statistical characteristics of echoes from ionospheric (E- and F-region field-aligned irregularities obtained with the Piura VHF radar. This radar is located at ~ 7.0° dip latitude, just outside the equatorial electrojet (EEJ region. Our results are based on (1 intermittent observations made between 1991 and 1999 just few days a year, and (2 continuous observations made between January 2000 and June 2001. During most of the intermittent observations, simultaneous measurements of EEJ and equatorial spread F (ESF irregularities were performed with the Jicamarca VHF radar. From the continuous measurements, we have obtained the diurnal and seasonal characteristics of a variety of parameters (percentage of occurrence, signal-to-noise ratio and/or Doppler velocities from the lower and upper E-region irregularities and also from F-region irregularities over Piura. For example, we have found that (1 the E-region echoes are stronger and occur more frequently during local summer (i.e. between December and March; (2 between May and June, the E-region echoes are weaker and occur less frequently; moreover, during these months, a semidiurnal wave with large amplitudes is observed in the meridional wind (> 100 ms- 1; (3 there is vertical wavelength of about 20 km in the Doppler velocity, particularly after midnight; (4 the lower (upper E-region Doppler velocities are influenced mainly by meridional winds (equatorial F-region vertical drifts. In addition, we have observed that the seasonal and daily occurrences of Piura F-region irregularities are similar to the occurrence of topside ESF irregularities over Jicamarca. The likelihood of occurrence of F-region irregularities over Piura and, therefore, topside ESF over Jicamarca is greater when there are no E-region irregularities over Piura. On the other hand, there is more probability of observing bottomtype/bottomside ESF irregularities over Jicamarca when E-region irregularities

  1. PMSE observations with the EISCAT VHF- and UHF-radars: Ice particles and their effect on ambient electron densities

    Science.gov (United States)

    Li, Qiang; Rapp, Markus

    2013-11-01

    It is now well understood that the occurrence of PMSE is closely connected to the presence of ice particles. These ice particles modify the ambient electron density by electron attachment which occasionally leads to large electron density depletions which have also been called ‘biteouts’. There has been some debate in the literature regarding the relative depth of such depletions which is usually expressed by the parameter Λ=|ZA|NA/ne. Here, |ZA|NA is the charge number density of ice particles and ne is the electron density. In this paper, we present, for the first time, the statistical distribution of Λ using measurements with the EISCAT VHF- and UHF-radars. Based on 25 h of simultaneous observations, we derived a total of 757 Λ values based on 15 min of data each. In each of these cases, PMSE were observed with the EISCAT VHF-radar but not with the UHF-radar and the UHF-measurement were hence used to determine the electron density profile. From these 757 cases, there are 699 cases with Λ⪡1, and only 33 cases with Λ>0.5 (21 cases with Λ>1). A correlation analysis of Λ versus PMSE volume reflectivities further reveals that there is no strong dependence between the two parameters. This is in accordance with current PMSE-theory based on turbulence in combination with a large Schmidt-number. The maxima of Λ from each profile show a negative relationship with the undisturbed electron densities deduced at the same altitudes. This reveals that the variability of Λ mainly depends on the variability of the electron densities. In addition, variations of aerosol number densities may also play a role. Although part of the observations were conducted during the HF heating experiments, the so-called overshoot effects did not significantly bias our statistical results. In order to avoid missing biteouts because of a superposition of coherent and incoherent scatter in the UHF-data, we finally calculated spectral parameters n by applying a simple fit to auto

  2. Waste Transfer Stations

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund

    2011-01-01

    tion and transport is usually the most costly part of any waste management system; and when waste is transported over a considerable distance or for a long time, transferring the waste from the collection vehicles to more efficient transportation may be economically beneficial. This involves...... a transfer station where the transfer takes place. These stations may also be accessible by private people, offering flexibility to the waste system, including facilities for bulky waste, household hazardous waste and recyclables. Waste transfer may also take place on the collection route from small...... describes the main features of waste transfer stations, including some considerations about the economical aspects on when transfer is advisable....

  3. Space station operations management

    Science.gov (United States)

    Cannon, Kathleen V.

    1989-01-01

    Space Station Freedom operations management concepts must be responsive to the unique challenges presented by the permanently manned international laboratory. Space Station Freedom will be assembled over a three year period where the operational environment will change as significant capability plateaus are reached. First Element Launch, Man-Tended Capability, and Permanent Manned Capability, represent milestones in operational capability that is increasing toward mature operations capability. Operations management concepts are being developed to accomodate the varying operational capabilities during assembly, as well as the mature operational environment. This paper describes operations management concepts designed to accomodate the uniqueness of Space Station Freedoom, utilizing tools and processes that seek to control operations costs.

  4. Potential of commercial microwave link network derived rainfall for river runoff simulations

    Science.gov (United States)

    Smiatek, Gerhard; Keis, Felix; Chwala, Christian; Fersch, Benjamin; Kunstmann, Harald

    2017-03-01

    Commercial microwave link networks allow for the quantification of path integrated precipitation because the attenuation by hydrometeors correlates with rainfall between transmitter and receiver stations. The networks, operated and maintained by cellphone companies, thereby provide completely new and country wide precipitation measurements. As the density of traditional precipitation station networks worldwide is significantly decreasing, microwave link derived precipitation estimates receive increasing attention not only by hydrologists but also by meteorological and hydrological services. We investigate the potential of microwave derived precipitation estimates for streamflow prediction and water balance analyses, exemplarily shown for an orographically complex region in the German Alps (River Ammer). We investigate the additional value of link derived rainfall estimations combined with station observations compared to station and weather radar derived values. Our river runoff simulation system employs a distributed hydrological model at 100 × 100 m grid resolution. We analyze the potential of microwave link derived precipitation estimates for two episodes of 30 days with typically moderate river flow and an episode of extreme flooding. The simulation results indicate the potential of this novel precipitation monitoring method: a significant improvement in hydrograph reproduction has been achieved in the extreme flooding period that was characterized by a large number of local strong precipitation events. The present rainfall monitoring gauges alone were not able to correctly capture these events.

  5. A Microwave Radiance Assimilation Study for a Tundra Snowpack

    Science.gov (United States)

    Kim, Edward; Durand, Michael; Margulis, Steve; England, Anthony

    2010-01-01

    Recent studies have begun exploring the assimilation of microwave radiances for the modeling and retrieval of snow properties. At a point scale, and for short durations (i week), radiance assimilation (RA) results are encouraging. However, in order to determine how practical RA might be for snow retrievals when applied over longer durations, larger spatial scales, and/or different snow types, we must expand the scope of the tests. In this paper we use coincident microwave radiance measurements and station data from a tundra site on the North Slope of Alaska. The field data are from the 3rd Radio-brightness Energy Balance Experiment (REBEX-3) carried out in 1994-95 by the University of Michigan. This dataset will provide a test of RA over months instead of one week, and for a very different type of snow than previous snow RA studies. We will address the following questions: flow well can a snowpack physical model (SM), forced with local weather, match measured conditions for a tundra snowpack?; How well can a microwave emission model, driven by the snowpack model, match measured microwave brightnesses for a tundra snowpack?; How well does RA increase or decrease the fidelity of estimates of snow depth and temperatures for a tundra snowpack?

  6. TV Analog Station Transmitters

    Data.gov (United States)

    Department of Homeland Security — This file is an extract from the Consolidated Database System (CDBS) licensed by the Media Bureau. It consists of Analog Television Stations (see Rule Part47 CFR...

  7. ASOS Station Photos

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The images contained in this library are of stations in the Automated Surface Observing System (ASOS) network. These images were taken between 1998-2001 for the ASOS...

  8. Signal Station Inspection Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Handwritten reports resulting from detailed inspections of US Army Signal Service Stations, 1871-1889. Features reported included instrument exposure and condition,...

  9. Active Marine Station Metadata

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

  10. Master Station History Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Standard/Legacy MSHR, formally identified as the DSI-9767 dataset, is the legacy dataset/report sorted by NCDC Station ID and period of record. This...

  11. Materials Test Station

    Data.gov (United States)

    Federal Laboratory Consortium — When completed, the Materials Test Station at the Los Alamos Neutron Science Center will meet mission need. MTS will provide the only fast-reactor-like irradiation...

  12. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  13. USRCRN Station Information

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Documentation of United States Regional Climate Reference Network (USRCRN) installations in 2009. Installations documented are for USRCRN pilot project stations in...

  14. Station Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The following plan is the result of a recent initiative in Region 5 to produce general management guidance based on stated objectives for individual field stations....

  15. "Central Station" Londonis

    Index Scriptorium Estoniae

    2000-01-01

    Londoni galeriis Milch seitsme läti, leedu ja eesti kunstniku projekt "Central Station". Kuraatorid Lisa Panting, Sally Tallant. Eestist osalevad Hanno Soans (Catarina Campinoga koostöös valminud video), Kiwa, Kai Kaljo

  16. Electrostatic pickup station

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    Electrostatic pickup station, with 4 interleaved electrodes, to measure beam position in the horizontal and vertical plane. This type is used in the transfer lines leaving the PS (TT2, TT70, TTL2). See also 7904075.

  17. Mukilteo Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — Research at the Mukilteo Research Station focuses on understanding the life cycle of marine species and the impacts of ecosystem stressors on anadromous and marine...

  18. Maine Field Station

    Data.gov (United States)

    Federal Laboratory Consortium — In 2000 NOAA's National Marine Fisheries Service established the Maine Field Station in Orono, ME to have more direct involvement in the conservation of the living...

  19. Routes and Stations

    Data.gov (United States)

    Department of Homeland Security — he Routes_Stations table is composed of fixed rail transit systems within the Continental United States, Alaska, Hawaii, the District of Columbia, and Puerto Rico....

  20. Public Transit Stations

    Data.gov (United States)

    Department of Homeland Security — fixed rail transit stations within the Continental United States, Alaska, Hawaii, the District of Columbia, and Puerto Rico. The modes of transit that are serviced...

  1. FEMA DFIRM Station Start

    Data.gov (United States)

    Minnesota Department of Natural Resources — This table contains information about station starting locations. These locations indicate the reference point that was used as the origin for distance measurements...

  2. Toward all weather, long record, and real-time land surface temperature retrievals from microwave satellite observations

    Science.gov (United States)

    Jimenez, Carlos; Prigent, Catherine; Aires, Filipe; Ermida, Sofia

    2017-04-01

    The land surface temperature can be estimated from satellite passive microwave observations, with limited contamination from the clouds as compared to the infrared satellite retrievals. With ˜60% cloud cover in average over the globe, there is a need for "all weather," long record, and real-time estimates of land surface temperature (Ts) from microwaves. A simple yet accurate methodology is developed to derive the land surface temperature from microwave conical scanner observations, with the help of pre-calculated land surface microwave emissivities. The method is applied to the Special Sensor Microwave/Imagers (SSM/I) and the Earth observation satellite (EOS) Advanced Microwave Scanning Radiometer (AMSR-E) observations?, regardless of the cloud cover. The SSM/I results are compared to infrared estimates from International Satellite Cloud Climatology Project (ISCCP) and from Advanced Along Track Scanning Radiometer (AATSR), under clear-sky conditions. Limited biases are observed (˜0.5 K for both comparisons) with a root-mean-square difference (RMSD) of ˜5 K, to be compared to the RMSE of ˜3.5 K between ISCCP et AATSR. AMSR-E results are compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) clear-sky estimates. As both instruments are on board the same satellite, this reduces the uncertainty associated to the observations match-up, resulting in a lower RMSD of ˜ 4K. The microwave Ts is compared to in situ Ts time series from a collection of ground stations over a large range of environments. For 22 stations available in the 2003-2004 period, SSM/I Ts agrees very well for stations in vegetated environments (down to RMSD of ˜2.5 K for several stations), but the retrieval methodology encounters difficulties under cold conditions due to the large variability of snow and ice surface emissivities. For 10 stations in the year 2010, AMSR-E presents an all-station mean RMSD of ˜4.0 K with respect tom the ground Ts. Over the same stations, MODIS

  3. Microwave systems design

    CERN Document Server

    Awang, Zaiki

    2014-01-01

    The aim of this book is to serve as a design reference for students and as an up-to-date reference for researchers. It also acts as an excellent introduction for newcomers to the field and offers established rf/microwave engineers a comprehensive refresher.  The content is roughly classified into two – the first two chapters provide the necessary fundamentals, while the last three chapters focus on design and applications. Chapter 2 covers detailed treatment of transmission lines. The Smith chart is utilized in this chapter as an important tool in the synthesis of matching networks for microwave amplifiers. Chapter 3 contains an exhaustive review of microstrip circuits, culled from various references. Chapter 4 offers practical design information on solid state amplifiers, while Chapter 5 contains topics on the design of modern planar filters, some of which were seldom published previously. A set of problems at the end of each chapter provides the readers with exercises which were compiled from actual uni...

  4. Enhanced Master Station History Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Enhanced Master Station History Report (EMSHR) is a compiled list of basic, historical information for every station in the station history database, beginning...

  5. Gas Stations, US, 2010, NAVTEQ

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Gas_Stations dataset is derived from the Navteq 'AUTOSVC' SDC layer (FAC_TYPE=5540) and contains gas stations and petrol stations. This NAVTEQ dataset is...

  6. The Princess Elisabeth Station

    Science.gov (United States)

    Berte, Johan

    2012-01-01

    Aware of the increasing impact of human activities on the Earth system, Belgian Science Policy Office (Belspo) launched in 1997 a research programme in support of a sustainable development policy. This umbrella programme included the Belgian Scientific Programme on Antarctic Research. The International Polar Foundation, an organization led by the civil engineer and explorer Alain Hubert, was commissioned by the Belgian Federal government in 2004 to design, construct and operate a new Belgian Antarctic Research Station as an element under this umbrella programme. The station was to be designed as a central location for investigating the characteristic sequence of Antarctic geographical regions (polynia, coast, ice shelf, ice sheet, marginal mountain area and dry valleys, inland plateau) within a radius of 200 kilometers (approx.124 miles) of a selected site. The station was also to be designed as "state of the art" with respect to sustainable development, energy consumption, and waste disposal, with a minimum lifetime of 25 years. The goal of the project was to build a station and enable science. So first we needed some basic requirements, which I have listed here; plus we had to finance the station ourselves. Our most important requirement was that we decided to make it a zero emissions station. This was both a philosophical choice as we thought it more consistent with Antarctic Treaty obligations and it was also a logistical advantage. If you are using renewable energy sources, you do not have to bring in all the fuel.

  7. Microwave power coupling with electron cyclotron resonance ...

    Indian Academy of Sciences (India)

    The effect of microwave power coupling to the plasma was studied by varying the microwave power. ... plasma is produced by the interaction of microwave radiation, in the presence of appro- priate magnetic field ... microwaves are used in resonant mode to couple the electromagnetic energy to the plasma for generating ...

  8. Comparison of wind measurements in the troposphere and mesosphere by VHF/MF radars and in-situ techniques

    Directory of Open Access Journals (Sweden)

    N. Engler

    2008-11-01

    Full Text Available Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less than the radiosonde data by about 15% for spaced antenna observations and by about 10% for the Doppler beam swinging experiment. At mesospheric altitudes the spaced antenna winds obtained from the wide-beam Andenes MF radar are underestimated in the order of 35% and winds from the narrow-beam Saura MF radar are underestimated by about 20% compared to falling sphere winds at altitudes between 70 and 80 km. Furthermore, the relation between wind measurements using narrow-beam and wide-beam antenna arrangements for the MF radars is discussed and VHF radar observations are compared to the wide-beam MF radar.

  9. Comparison of wind measurements in the troposphere and mesosphere by VHF/MF radars and in-situ techniques

    Science.gov (United States)

    Engler, N.; Singer, W.; Latteck, R.; Strelnikov, B.

    2008-11-01

    Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less than the radiosonde data by about 15% for spaced antenna observations and by about 10% for the Doppler beam swinging experiment. At mesospheric altitudes the spaced antenna winds obtained from the wide-beam Andenes MF radar are underestimated in the order of 35% and winds from the narrow-beam Saura MF radar are underestimated by about 20% compared to falling sphere winds at altitudes between 70 and 80 km. Furthermore, the relation between wind measurements using narrow-beam and wide-beam antenna arrangements for the MF radars is discussed and VHF radar observations are compared to the wide-beam MF radar.

  10. Observation of polar mesosphere summer echoes with calibrated VHF radars at 69° in the Northern and Southern hemispheres

    Science.gov (United States)

    Latteck, R.; Singer, W.; Morris, R. J.; Holdsworth, D. A.; Murphy, D. J.

    2007-07-01

    Polar Mesosphere Summer Echoes (PMSE) observed in the northern and southern hemisphere were studied using continuous measurements obtained by calibrated VHF radars located at Andenes (69.3°N) and Davis (68.6°S) during the boreal summer 2004 and the austral summer 2004/2005. The PMSE observed at Davis have a lower peak volume reflectivity of approximately 4 . 10-11 m-1 compared with their counterparts (7 . 10-10 m-1) observed at Andenes. The duration of the PMSE season is correlated with the dynamical and thermal state of the mesopause region supported by recent studies using meridional winds and temperatures. PMSE occurred less frequently but with greater variability above Davis. The diurnal variation of PMSE occurrence has a maximum around 11-16 LT in both hemispheres, and a minimum occurs during late evening with a longer duration in the southern hemisphere. The mean PMSE season at both sites started around 34 days before solstice, but the duration of the Davis PMSE season is about 9 days shorter than at Andenes. The maximum occurrence height of PMSE at Davis is 86 km which is about 1 km higher than at Andenes.

  11. Comparison of wind measurements in the troposphere and mesosphere by VHF/MF radars and in-situ techniques

    Energy Technology Data Exchange (ETDEWEB)

    Engler, N.; Singer, W.; Latteck, R.; Strelnikov, B. [Rostock Univ., Kuehlungsborn (Germany). Leibniz Inst. of Atmospheric Physics

    2008-07-01

    Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less than the radiosonde data by about 15% for spaced antenna observations and by about 10% for the Doppler beam swinging experiment. At mesospheric altitudes the spaced antenna winds obtained from the wide-beam Andenes MF radar are underestimated in the order of 35% and winds from the narrow-beam Saura MF radar are underestimated by about 20% compared to falling sphere winds at altitudes between 70 and 80 km. Furthermore, the relation between wind measurements using narrow-beam and wide-beam antenna arrangements for the MF radars is discussed and VHF radar observations are compared to the wide-beam MF radar. (orig.)

  12. Calculating the azimuth of mountain waves, using the effect of tilted fine-scale stable layers on VHF radar echoes

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    1999-02-01

    Full Text Available A simple method is described, based on standard VHF wind-profiler data, where imbalances of echo power between four off-vertical radar beams, caused by mountain waves, can be used to calculate the orientation of the wave pattern. It is shown that the mountain wave azimuth (direction of the horizontal component of the wavevector, is given by the vector [ W (PE - P W ,W (PN - P S ]; PN, PS, PE, PW are radar echo powers, measured in dB, in beams pointed away from vertical by the same angle towards north, south, east and west respectively, and W is the vertical wind velocity. The method is applied to Aberystwyth MST radar data, and the calculated wave vector usually, but not always, points into the low-level wind direction. The mean vertical wind at Aberystwyth, which may also be affected by tilted aspect-sensitive layers, is investigated briefly using the entire radar output 1990-1997. The mean vertical-wind profile is inconsistent with existing theories, but a new mountain-wave interpretation is proposed.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides; instruments and techniques.

  13. Effect of power on growth of nanocrystalline silicon films deposited by VHF PECVD technique for solar cell applications

    Science.gov (United States)

    Juneja, Sucheta; Verma, Payal; Savelyev, Dmitry A.; Khonina, Svetlana N.; Sudhakar, S.; Kumar, Sushil

    2016-04-01

    An investigation of the effect of power on the deposition of nanocrystalline silicon thin films were carried out using a gaseous mixture of silane and hydrogen in the 60MHz assisted VHF plasma enhanced chemical vapor deposition (PECVD) technique. The power was varied from 10 to 50 watt maintaining all other parameters constant. Corresponding layer properties w.r.t. material microstructure, optical, hydrogen content and electrical transport are studied in detail. The structural properties have been studied by Raman spectroscopy and x-ray diffraction (XRD). The presence of nano-sized crystals and their morphology have been investigated using atomic force microscopy (AFM). The role of bonded hydrogen content in the films have been studied from the results of Fourier transform infrared spectroscopy. It was observed from the results that with increase in power, crystalline volume fraction increases and crystallite size changes from 4 to 9 nm. The optical band gap varies from 1.7 to 2.1eV due to quantum confinement effect and which further can be explained with reduced hydrogen content. These striking features of nc-Si films can be used to fabricate stable thin film solar cells.

  14. Case study of stratospheric gravity waves of convective origin over Arctic Scandinavia. VHF radar observations and numerical modelling

    Energy Technology Data Exchange (ETDEWEB)

    Rechou, A. [La Reunion Univ., St. Denis Messag, Ile de La Reunion (France). Lab. de l' Atmosphere et des Cyclones; Arnault, J.; Dalin, P.; Kirkwood, S. [Swedish Institute of Space Physics, Kiruna (Sweden)

    2013-03-01

    Orography is a well-known source of gravity and inertia-gravity waves in the atmosphere. Other sources, such as convection, are also known to be potentially important but the large amplitude of orographic waves over Scandinavia has generally precluded the possibility to study such other sources experimentally in this region. In order to better understand the origin of stratospheric gravity waves observed by the VHF radar ESRAD (Esrange MST radar) over Kiruna, in Arctic Sweden (67.88 N, 21.10 E), observations have been compared to simulations made using the Weather Research and Forecasting model (WRF) with and without the effects of orography and clouds. This case study concerns gravity waves observed from 00:00 UTC on 18 February to 12:00 UTC on 20 February 2007. We focus on the wave signatures in the static stability field and vertical wind deduced from the simulations and from the observations as these are the parameters which are provided by the observations with the best height coverage. As is common at this site, orographic gravity waves were produced over the Scandinavian mountains and observed by the radar. However, at the same time, southward propagation of fronts in the Barents Sea created short-period waves which propagated into the stratosphere and were transported, embedded in the cyclonic winds, over the radar site. (orig.)

  15. Development of a Coherent Bistatic Vegetation Model for Signal of Opportunity Applications at VHF UHF-Bands

    Science.gov (United States)

    Kurum, Mehmet; Deshpande, Manohar; Joseph, Alicia T.; O'Neill, Peggy E.; Lang, Roger H.; Eroglu, Orhan

    2017-01-01

    A coherent bistatic vegetation scattering model, based on a Monte Carlo simulation, is being developed to simulate polarimetric bi-static reflectometry at VHF/UHF-bands (240-270 MHz). The model is aimed to assess the value of geostationary satellite signals of opportunity to enable estimation of the Earth's biomass and root-zone soil moisture. An expression for bistatic scattering from a vegetation canopy is derived for the practical case of a ground-based/low altitude platforms with passive receivers overlooking vegetation. Using analytical wave theory in conjunction with distorted Born approximation (DBA), the transmit and receive antennas effects (i.e., polarization, orientation, height, etc.) are explicitly accounted for. Both the coherency nature of the model (joint phase and amplitude information) and the explicit account of system parameters (antenna, altitude, polarization, etc) enable one to perform various beamforming techniques to evaluate realistic deployment configurations. In this paper, several test scenarios will be presented and the results will be evaluated for feasibility for future biomass and root-zone soil moisture application using geostationary communication satellite signals of opportunity at low frequencies.

  16. Scattering Effects of Solar Panels on Space Station Antenna Performance

    Science.gov (United States)

    Panneton, Robert J.; Ngo, John C.; Hwu, Shian U.; Johnson, Larry A.; Elmore, James D.; Lu, Ba P.; Kelley, James S.

    1994-01-01

    Characterizing the scattering properties of the solar array panels is important in predicting Space Station antenna performance. A series of far-field, near-field, and radar cross section (RCS) scattering measurements were performed at S-Band and Ku-Band microwave frequencies on Space Station solar array panels. Based on investigation of the measured scattering patterns, the solar array panels exhibit similar scattering properties to that of the same size aluminum or copper panel mockup. As a first order approximation, and for worse case interference simulation, the solar array panels may be modeled using perfect reflecting plates. Numerical results obtained using the Geometrical Theory of Diffraction (GTD) modeling technique are presented for Space Station antenna pattern degradation due to solar panel interference. The computational and experimental techniques presented in this paper are applicable for antennas mounted on other platforms such as ship, aircraft, satellite, and space or land vehicle.

  17. Nighttime enhancements in total electron content near Arecibo and their association with VHF scintillations

    Energy Technology Data Exchange (ETDEWEB)

    Kersley, L.; Aarons, J.; Klobuchar, J.A.

    1980-08-01

    From the analysis of 16 months of transionospheric propagation data taken near Arecibo it has been found that there are associations between nighttime enhancements and quasi-periodic fluctuations in total electron content and the occurrence of amplitude scintillations. A postmidnight peak is found in the occurrence of electron content increases, maximum wave activity, and largest scintillation index, with some evidence to suggest a second premidnight peak in winter and reduced probability of the features being found at equinox. An analysis of the large-scale variations of the total content data for three stations has shown that the postsunset minimum in electron content propagates at high speed toward the northeast, while the premidnight minimum advances toward the south with the main postmidnight maximum having northward component of motion. The results are discussed in terms of the known dynamical features of the ionosphere at Arecibo and in particular the effects of the neutral wind on the bottpmside ionosphere. It appears that conditions conducive to the production of nighttime enhancements in total electron content may also allow the penetration of medium scale gravity waves through the lower thermosphere with an unstable breakdown process giving rise to the development of scintillation-producing irregularities.

  18. Microwave mixer technology and applications

    CERN Document Server

    Henderson, Bert

    2013-01-01

    Although microwave mixers play a critical role in wireless communication and other microwave applications employing frequency conversion circuits, engineers find that most books on this subject emphasize theoretical aspects, rather than practical applications. That's about to change with the forthcoming release of Microwave Mixer Technology and Applications. Based on a review of over one thousand patents on mixers and frequency conversion, authors Bert Henderson and Edmar Camargo have written a comprehensive book for mixer designers who want solid ideas for solving their own design challenges.

  19. Fast microwave assisted pyrolysis of biomass using microwave absorbent.

    Science.gov (United States)

    Borges, Fernanda Cabral; Du, Zhenyi; Xie, Qinglong; Trierweiler, Jorge Otávio; Cheng, Yanling; Wan, Yiqin; Liu, Yuhuan; Zhu, Rongbi; Lin, Xiangyang; Chen, Paul; Ruan, Roger

    2014-03-01

    A novel concept of fast microwave assisted pyrolysis (fMAP) in the presence of microwave absorbents was presented and examined. Wood sawdust and corn stover were pyrolyzed by means of microwave heating and silicon carbide (SiC) as microwave absorbent. The bio-oil was characterized, and the effects of temperature, feedstock loading, particle sizes, and vacuum degree were analyzed. For wood sawdust, a temperature of 480°C, 50 grit SiC, with 2g/min of biomass feeding, were the optimal conditions, with a maximum bio-oil yield of 65 wt.%. For corn stover, temperatures ranging from 490°C to 560°C, biomass particle sizes from 0.9mm to 1.9mm, and vacuum degree lower than 100mmHg obtained a maximum bio-oil yield of 64 wt.%. This study shows that the use of microwave absorbents for fMAP is feasible and a promising technology to improve the practical values and commercial application outlook of microwave based pyrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Telephony Earth Station

    Science.gov (United States)

    Morris, Adrian J.; Kay, Stan

    The Telephony Earth Station (TES), a digital full-mesh SCPC (single channel per carrier) system designed for satellite voice and data transmission is described. As compared to companded FM, the advanced speech compression and forward error correction techniques used by TES better achieve the quality, power, and bandwidth ideal for each application. In addition, the TES offers a fully demand-assigned voice call setup, handles point-to-point data channels, supports a variety of signaling schemes, and does not require any separate pilot receivers at the station, while keeping costs low through innovative technology and packaging. The TES can be used for both C-band and Ku-band (domestic or international) applications, and is configurable either as an VSAT (very small aperture terminal) using an SSPA, or as a larger station depending on the capacity requirements. A centralized DAMA processor and network manager is implemented using a workstation.

  1. Hydrogen Fuelling Stations

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard

    This thesis concerns hydrogen fuelling stations from an overall system perspective. The study investigates thermodynamics and energy consumption of hydrogen fuelling stations for fuelling vehicles for personal transportation. For the study a library concerning the components in a hydrogen fuelling...... station has been developed in Dymola. The models include the fuelling protocol (J2601) for hydrogen vehicles made by Society of Automotive Engineers (SAE) and the thermodynamic property library CoolProp is used for retrieving state point. The components in the hydrogen fuelling library are building up....... A system consisting of one high pressure storage tank is used to investigate the thermodynamics of fuelling a hydrogen vehicle. The results show that the decisive parameter for how the fuelling proceeds is the pressure loss in the vehicle. The single tank fuelling system is compared to a cascade fuelling...

  2. Wide spectrum microwave pulse measurement

    Energy Technology Data Exchange (ETDEWEB)

    King, R.J.

    1986-01-01

    Various techniques are postulated as diagnostics for wide band microwave pulses. The diagnostics include determinations of both the instantaneous amplitude and the frequency content of one-shot pulses. 6 refs., 11 figs. (WRF)

  3. Scanning Microwave Induced Acoustic Tomography

    National Research Council Canada - National Science Library

    Wang, Lihong V

    2001-01-01

    .... Cancerous breast tissues are found to be 2-5 times more strongly absorbing than surrounding normal breast tissues in the microwave, which has been attributed to an increase in bound water and sodium...

  4. Hydrogen vehicle fueling station

    Energy Technology Data Exchange (ETDEWEB)

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A. [Los Alamos National Lab., NM (United States)] [and others

    1995-09-01

    Hydrogen fueling stations are an essential element in the practical application of hydrogen as a vehicle fuel, and a number of issues such as safety, efficiency, design, and operating procedures can only be accurately addressed by a practical demonstration. Regardless of whether the vehicle is powered by an internal combustion engine or fuel cell, or whether the vehicle has a liquid or gaseous fuel tank, the fueling station is a critical technology which is the link between the local storage facility and the vehicle. Because most merchant hydrogen delivered in the US today (and in the near future) is in liquid form due to the overall economics of production and delivery, we believe a practical refueling station should be designed to receive liquid. Systems studies confirm this assumption for stations fueling up to about 300 vehicles. Our fueling station, aimed at refueling fleet vehicles, will receive hydrogen as a liquid and dispense it as either liquid, high pressure gas, or low pressure gas. Thus, it can refuel any of the three types of tanks proposed for hydrogen-powered vehicles -- liquid, gaseous, or hydride. The paper discusses the fueling station design. Results of a numerical model of liquid hydrogen vehicle tank filling, with emphasis on no vent filling, are presented to illustrate the usefulness of the model as a design tool. Results of our vehicle performance model illustrate our thesis that it is too early to judge what the preferred method of on-board vehicle fuel storage will be in practice -- thus our decision to accommodate all three methods.

  5. Microwave remote sensing from space

    OpenAIRE

    Carver, Keith R.; Elachi, Charles; Ulaby, Fawwaz T.

    1985-01-01

    Spaceborne microwave remote sensors provide perspectives of the earth surface and atmosphere which are of unique value in scientific studies of geomorphology, oceanic waves and topography, atmospheric water vapor and temperatures, vegetation classification and stress, ice types and dynamics, and hydrological characteristics. Microwave radars and radiometers offer enhanced sensitivities to the geometrical characteristics of the earth's surface and its cover, to water in all its forms--soil and...

  6. Microwave applications of soft ferrites

    CERN Document Server

    Pardavi-Horvath, M P

    2000-01-01

    Signal processing requires broadband, low-loss, low-cost microwave devices (circulators, isolators, phase shifters, absorbers). Soft ferrites (garnets, spinels, hexaferrites), applied in planar microwave devices, are reviewed from the point of view of device requirements. Magnetic properties, specific to operation in high-frequency electromagnetic fields, are discussed. Recent developments in thick film ferrite technology and device design are reviewed. Magnetic losses related to planar shape and inhomogeneous internal fields are analyzed.

  7. Cosmic microwave background, where next?

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Ground-based, balloon-borne and space-based experiments will observe the Cosmic Microwave Background in greater details to address open questions about the origin and the evolution of the Universe. In particular, detailed observations the polarization pattern of the Cosmic Microwave Background radiation have the potential to directly probe physics at the GUT scale and illuminate aspects of the physics of the very early Universe.

  8. The organized Space Station

    Science.gov (United States)

    Lew, Leong W.

    Space Station organization designers should consider the onboard stowage system to be an integral part of the environment structured for productive working conditions. In order to achieve this, it is essential to use an efficient inventory control system able to track approximately 50,000 items over a 90-day period, while maintaining peak crew performance. It is noted that a state-of-the-art bar-code inventory management system cannot satisfy all Space Station requirements, such as the location of a critical missing item.

  9. Microwave remote sensing from space

    Science.gov (United States)

    Carver, K. R.; Elachi, C.; Ulaby, F. T.

    1985-01-01

    Spaceborne microwave remote sensors provide perspectives of the earth surface and atmosphere which are of unique value in scientific studies of geomorphology, oceanic waves and topography, atmospheric water vapor and temperatures, vegetation classification and stress, ice types and dynamics, and hydrological characteristics. Microwave radars and radiometers offer enhanced sensitivities to the geometrical characteristics of the earth's surface and its cover, to water in all its forms - soil and vegetation moisture, ice, wetlands, oceans, and atmospheric water vapor, and can provide high-resolution imagery of the earth's surface independent of cloud cover or sun angle. A brief review of the historical development and principles of active and passive microwave remote sensing is presented, with emphasis on the unique characteristics of the information obtainable in the microwave spectrum and the value of this information to global geoscientific studies. Various spaceborne microwave remote sensors are described, with applications to geology, planetology, oceanography, glaciology, land biology, meteorology, and hydrology. A discussion of future microwave remote sensor technological developments and challenges is presented, along with a summary of future missions being planned by several countries.

  10. Tunable Multiband Microwave Photonic Filters

    Directory of Open Access Journals (Sweden)

    Mable P. Fok

    2017-11-01

    Full Text Available The increasing demand for multifunctional devices, the use of cognitive wireless technology to solve the frequency resource shortage problem, as well as the capabilities and operational flexibility necessary to meet ever-changing environment result in an urgent need of multiband wireless communications. Spectral filter is an essential part of any communication systems, and in the case of multiband wireless communications, tunable multiband RF filters are required for channel selection, noise/interference removal, and RF signal processing. Unfortunately, it is difficult for RF electronics to achieve both tunable and multiband spectral filtering. Recent advancements of microwave photonics have proven itself to be a promising candidate to solve various challenges in RF electronics including spectral filtering, however, the development of multiband microwave photonic filtering still faces lots of difficulties, due to the limited scalability and tunability of existing microwave photonic schemes. In this review paper, we first discuss the challenges that were facing by multiband microwave photonic filter, then we review recent techniques that have been developed to tackle the challenge and lead to promising developments of tunable microwave photonic multiband filters. The successful design and implementation of tunable microwave photonic multiband filter facilitate the vision of dynamic multiband wireless communications and radio frequency signal processing for commercial, defense, and civilian applications.

  11. Microwave Drying of Moist Coals

    Science.gov (United States)

    Salomatov, Vl. V.; Karelin, V. A.; Sladkov, S. O.; Salomatov, Vas. V.

    2017-03-01

    Physical principles and examples of practical implementation of drying large bodies of coal by microwave radiation are considered. It is shown that energy consumption in microwave drying of brown coals decreases to 1.5-1.8 (kW·h)/ kg as compared with traditional types of drying, for which the expenditures of energy amount to 3.0 (kW·h)/kg. In using microwave drying, the technological time of drying decreases to 4 h, whereas the time of convective drying, with other things being equal, comes to 8-20 h. Parallel with microwave radiation drying, grinding of a fuel takes place, as well as entrainment of such toxic and ecologically harmful elements as mercury, chlorine, phosphorus, sulfur, and nitrogen. An analysis of the prospects of using a microwave energy for drying coal fuel has shown that microwave radiation makes it possible to considerably economize in energy, increase explosional safety, improve the ecological situation, and reduce the metal content and overall dimensions of the equipment.

  12. Study of federal microwave standards

    Energy Technology Data Exchange (ETDEWEB)

    David, L.

    1980-08-01

    Present and future federal regulatory processes which may impact the permissible levels of microwave radiation emitted by the SPS Microwave Power Transmission (MPTS) were studied. An historical development of US occupational and public microwave standards includes an overview of Western and East European philosophies of environmental protection and neurophysiology which have led to the current widely differing maximum permissible exposure limits to microwaves. The possible convergence of microwave standards is characterized by a lowering of Western exposure levels while Eastern countries consider standard relaxation. A trend toward stricter controls on activities perceived as harmful to public health is under way as is interest in improving the federal regulatory process. Particularly relevant to SPS is the initiation of long-term, low-level microwave exposure programs. Coupled with new developments in instrumentation and dosimetry, the results from chronic exposure program and population exposure studies could be expected within the next five to ten years. Also discussed is the increasing public concern that rf energy is yet another hazardous environmental agent.

  13. Spatial variability of the aspect sensitivity of VHF radar echoes in the troposphere and lower stratosphere during jet stream passages

    Directory of Open Access Journals (Sweden)

    J. G. Yoe

    Full Text Available The aspect sensitivity of SOUSY-VHF-radar oblique-beam echoes from the troposphere and lower stratosphere has been examined for a number of jet stream passages during the years 1990 - 1992. When the core of the jet is overhead or nearly so, vertical profiles of the aspect sensitivity display two notable features. First, the distinction between mainly isotropic and strongly aspect-sensitive echoes in the troposphere and the lower stratosphere, respectively, often reported for measurements made during calm conditions, does not necessarily prevail in the vicinity of the jet stream. Second, echoes obtained at altitudes near the height of the horizontal wind maximum are found to be more aspect sensitive for beams directed parallel to the horizontal flow or nearly so, than for other beam directions. It is demonstrated that time-averaged horizontal wind speeds estimated from the radar data, taking into account the reduced effective oblique-beam zenith angle resulting from aspect sensitivity, may exceed uncorrected wind speeds by as much as 10 m s-1 in these circumstances. Implications for wind profiling and for describing the backscattering process are discussed. Doppler spectral widths examined for one jet stream passage are found to be narrower in a beam aligned with the horizontal wind at heights near the wind speed maximum than corresponding widths measured in a beam projected at right angles to the jet. The narrowest spectra thus coincide with the most aspect-sensitive echoes, consistent with the hypothesis that such returns result from specular backscattering processes.

  14. Calculating the azimuth of mountain waves, using the effect of tilted fine-scale stable layers on VHF radar echoes

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    Full Text Available A simple method is described, based on standard VHF wind-profiler data, where imbalances of echo power between four off-vertical radar beams, caused by mountain waves, can be used to calculate the orientation of the wave pattern. It is shown that the mountain wave azimuth (direction of the horizontal component of the wavevector, is given by the vector [ W (PE - P W ,W (PN - P S ]; PN, PS, PE, PW are radar echo powers, measured in dB, in beams pointed away from vertical by the same angle towards north, south, east and west respectively, and W is the vertical wind velocity. The method is applied to Aberystwyth MST radar data, and the calculated wave vector usually, but not always, points into the low-level wind direction. The mean vertical wind at Aberystwyth, which may also be affected by tilted aspect-sensitive layers, is investigated briefly using the entire radar output 1990-1997. The mean vertical-wind profile is inconsistent with existing theories, but a new mountain-wave interpretation is proposed.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides; instruments and techniques.

  15. Space Station Water Quality

    Science.gov (United States)

    Willis, Charles E. (Editor)

    1987-01-01

    The manned Space Station will exist as an isolated system for periods of up to 90 days. During this period, safe drinking water and breathable air must be provided for an eight member crew. Because of the large mass involved, it is not practical to consider supplying the Space Station with water from Earth. Therefore, it is necessary to depend upon recycled water to meet both the human and nonhuman water needs on the station. Sources of water that will be recycled include hygiene water, urine, and cabin humidity condensate. A certain amount of fresh water can be produced by CO2 reduction process. Additional fresh water will be introduced into the total pool by way of food, because of the free water contained in food and the water liberated by metabolic oxidation of the food. A panel of scientists and engineers with extensive experience in the various aspects of wastewater reuse was assembled for a 2 day workshop at NASA-Johnson. The panel included individuals with expertise in toxicology, chemistry, microbiology, and sanitary engineering. A review of Space Station water reclamation systems was provided.

  16. Galileo Station Keeping Strategy

    Science.gov (United States)

    Perez-Cambriles, Antonio; Bejar-Romero, Juan Antonio; Aguilar-Taboada, Daniel; Perez-Lopez, Fernando; Navarro, Daniel

    2007-01-01

    This paper presents analyses done for the design and implementation of the Maneuver Planning software of the Galileo Flight Dynamics Facility. The station keeping requirements of the constellation have been analyzed in order to identify the key parameters to be taken into account in the design and implementation of the software.

  17. Kiowa Creek Switching Station

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  18. Summit Station Skiway Review

    Science.gov (United States)

    2013-03-01

    operating procedures (SOPs) for future construction and maintenance efforts. DISCLAIMER: The contents of this report are not to be used for...Runway Construction .......................................................... 22 Appendix B: Rammsonde Instructions...13. Snow accumulation at Summit Station in the Bamboo Forest. .......................................... 13 Figure 14. Strength of Summit skiway

  19. Electrostatic pickup station

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    Electrostatic pickup station, with 4 electrodes, to measure beam position in the horizontal and vertical plane. This type is used in the transfer lines leaving the PS (TT2, TTL2, TT70). See also 8206063, where the electrode shapes are clearly visible.

  20. Designing a Weather Station

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

  1. Intersunspot Microwave Sources

    Science.gov (United States)

    Bakunina, I. A.; Melnikov, V. F.; Solov'ev, A. A.; Abramov-Maximov, V. E.

    2015-01-01

    We studied a number of solar active regions using two-dimensional spatially resolved microwave observations. Data from the Nobeyama Radioheliograph and the Siberian Solar Radio Telescope together with observations by the Michelson Doppler Imager (MDI) onboard the Solar and Heliospheric Observatory (SOHO) have allowed us to identify long-lived intersunspot sources (ISSs) in most of the investigated active regions. Their centers are often located above the line-of-sight magnetic field inversion line that separates the leading and following polarities of a full active region (first type of ISS) or above the inversion line that separates magnetic polarities inside of a complex of sunspots (second type of ISS). ISSs of the first type are extended and, in general, they are sources of bremsstrahlung emission. ISSs of the second type are compact and are, most likely, sources of gyroresonance or gyrosynchrotron emission. We propose a qualitative model involving three types of magnetic connectivity to explain how long-lasting ISSs may be generated.

  2. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen

  3. New Small Satellite Capabilities for Microwave Atmospheric Remote Sensing: The Earth Observing Nanosatellite-Microwave (EON-MW)

    Science.gov (United States)

    Blackwell, W. J.

    2015-12-01

    Four nanosatellite advanced technology missions flying microwave radiometers for high-resolution atmospheric sensing are in varying stages of development. Microwave instrumentation is particularly well suited for implementation on a very small satellite, as the sensor requirements for power, pointing, and spatial resolution (aperture size) can be accommodated by a nanosatellite platform. The first mission, the Microsized Microwave Atmospheric Satellite (MicroMAS), was developed to demonstrate temperature sounding in nine channels near 118 GHz on a 3U CubeSat (10x10x34 cm; 4.25 kg). MicroMAS was recently released from the International Space Station (ISS) for a 100-day mission, and while an eventual transmitter failure prevented demonstration of the radiometer payload, all key spacecraft subsystems provided on-orbit data to validate performance. Two 3U CubeSat follow-on missions, MicroMAS-2 (12 channels near 90, 118, 183, and 206 GHz; cross-track scanning) and MiRaTA (12 channels near 60, 183, and 206 GHz; no scanning; GPSRO onboard), will launch in 2016 for further demonstration. Building upon this work, the Earth Observing Nanosatellite-Microwave mission is being formulated by MIT Lincoln Laboratory for the NOAA National Environmental Satellite, Data, and Information Service as part of the Polar Follow-On (PFO) budget request to extend JPSS for two more missions, and provides a means to mitigate the risk of a gap in continuity of weather observations. The PFO request aims to achieve robustness in the polar satellite system to ensure continuity of NOAA's polar weather observations. The baseline EON-MW design accommodates a scanning 22-channel high-resolution microwave spectrometer on a 12U (22x22x34 cm, 20 kg) CubeSat platform to provide data continuity with the existing AMSU and ATMS microwave sounding systems. EON-MW will nominally be launched into a sun-synchronous orbit for a two to three year mitigation mission in 2019 that will also extend technology

  4. Space solar power stations. Problems of energy generation and using its on the earth surface and nearest cosmos

    Science.gov (United States)

    Sinkevich, OA; Gerasimov, DN; Glazkov, VV

    2017-11-01

    Three important physical and technical problems for solar power stations (SPS) are considered: collection of solar energy and effective conversion of this energy to electricity in space power stations, energy transportation by the microwave beam to the Earth surface and direct utilization of the microwave beam energy for global environmental problems. Effectiveness of solar energy conversion into electricity in space power stations using gas and steam turbines plants, and magneto-hydrodynamic generator (MHDG) are analyzed. The closed cycle MHDG working on non–equilibrium magnetized plasmas of inert gases seeded with the alkaline metal vapors are considered. The special emphases are placed on MHDG and gas-turbine installations that are operating without compressor. Also opportunities for using the produced by space power stations energy for ecological needs on Earth and in Space are discussed.

  5. Battery charging stations

    Energy Technology Data Exchange (ETDEWEB)

    Bergey, M.

    1997-12-01

    This paper discusses the concept of battery charging stations (BCSs), designed to service rural owners of battery power sources. Many such power sources now are transported to urban areas for recharging. A BCS provides the opportunity to locate these facilities closer to the user, is often powered by renewable sources, or hybrid systems, takes advantage of economies of scale, and has the potential to provide lower cost of service, better service, and better cost recovery than other rural electrification programs. Typical systems discussed can service 200 to 1200 people, and consist of stations powered by photovoltaics, wind/PV, wind/diesel, or diesel only. Examples of installed systems are presented, followed by cost figures, economic analysis, and typical system design and performance numbers.

  6. Microwave Plasma System: PVA Tepla 300

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: Microwave AsherA tool using microwave oxygen plasma to remove organics on the surfacesSpecifications / Capabilities:Frequency: 2.45 GHzPower:...

  7. Student Microwave Experiments Involving the Doppler Effect.

    Science.gov (United States)

    Weber, F. Neff; And Others

    1980-01-01

    Described is the use of the Doppler Effect with microwaves in the measurement of the acceleration due to gravity of falling objects. The experiments described add to the repertoire of quantitative student microwave experiments. (Author/DS)

  8. DMSP SSM/I- Microwave Imager

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SSM/I is a seven-channel, four frequency, linearly-polarized, passive microwave radiometric system which measures atmospheric, ocean and terrain microwave...

  9. Digital microwave communication engineering point-to-point microwave systems

    CERN Document Server

    Kizer, George

    2013-01-01

    The first book to cover all engineering aspects of microwave communication path design for the digital age Fixed point-to-point microwave systems provide moderate-capacity digital transmission between well-defined locations. Most popular in situations where fiber optics or satellite communication is impractical, it is commonly used for cellular or PCS site interconnectivity where digital connectivity is needed but not economically available from other sources, and in private networks where reliability is most important. Until now, no book has adequately treated all en

  10. Observations of mesosphere summer echoes with calibrated VHF radars at latitudes between 54°N and 69°N in summer 2004

    Science.gov (United States)

    Latteck, R.; Singer, W.; Kirkwood, S.; Jönsson, L. O.; Eriksson, Håkan

    2005-08-01

    Mesosphere Summer Echoes (MSE) have been observed with 50-MHz VHF radars at middle (MSE) and polar latitudes (PMSE) for more than 20 years. The occurrence and seasonal variation of these radar echoes as well as their dependence on solar and geomagnetic activity are mostly studied basing on relative signal strength measurements (signal-to-noise ratios). The latitudinal dependence of the appearance and intensity of mesospheric summer echoes is still an open question as the widely used relative signal strength observations are determined by the atmospheric properties as well as by the individual radar characteristics. The use of absolutely calibrated echo powers allows a system in-depended comparison of mesospheric summer echoes observed at different sites by different systems. We present two different radar calibration methods. One applies a noise source to calibrate the receive path of the radar only, a second uses the radar signal itself to calibrate the complete transmitting and receiving path of the radar system. Both techniques and the same calibration hardware have been applied to the ALWIN VHF radar at Andenes/Norway (69°N), the ESRAD radar at Kiruna/Sweden (68deg;N) and OSWIN radar at Kühlungsborn/Germany (54°N). The sensitivity of the different radar systems and the seasonal and diurnal variation of the occurrence of mesospheric summer echoes at different locations are discussed on the basis of radar backscatter cross-sections.

  11. SISTEMA WEB DE GEOLOCALIZACIÓN Y MONITOREO DE LA TORTUGA PODOCNEMIS LEWYANA EN EL RÍO SINÚ, MEDIANTE EL USO DE ANTENAS VHF Y DISPOSITIVOS GPS

    Directory of Open Access Journals (Sweden)

    Mario Macea Anaya

    2016-03-01

    Full Text Available Este trabajo tiene como finalidad el diseño e implementación de una aplicación para el monitoreo de las Tortugas de Río Podocnemis Lewyana, utilizando las tecnologías GPS (Global Positioning System y VHF (Very High Frequency. La aplicación permite apoyar los procesos de conservación y recuperación de la especie en el Departamento de Córdoba, en las poblaciones de Caño Viejo y Cotocá Arriba del municipio Santa Cruz de Lorica, Colombia. El uso de esa herramienta está dirigido a biólogos y personas de las comunidades rurales dedicadas a conservar dicha especie. En el desarrollo del proyecto se utilizaron 18 Tortugas de Río para su monitoreo. El resultado del trabajo es la aplicación Web Podocnemis-Soft. Su funcionamiento se basa en un dispositivo GPS y VHF, ubicado en una o varias de las tortugas Podocnemis Lewyana; los dispositivos envían los datos de la ubicación de la tortuga hasta un servidor para su procesamiento y posterior visualización de la información.

  12. Relationship between propagation direction of gravity waves in OH and OI airglow images and VHF radar echo occurrence during the SEEK-2 campaign

    Directory of Open Access Journals (Sweden)

    F. Onoma

    2005-10-01

    Full Text Available We report simultaneous observations of atmospheric gravity waves (AGW in OI (557.7nm and OH airglow images and VHF radar backscatter from field-aligned irregularities (FAI in the E-region during the SEEK-2 (Sporadic-E Experiment over Kyushu 2 campaign period from 29 July to 9 August 2002. An all-sky imager was operated at Nishino-Omote (30.5 N, 130.1 E, Japan. On 14 nights, 17 AGW events were detected in OI and OH airglow images. AGW propagated mostly toward the northeast or southeast. From comparison with the E-region FAI occurrence, which is detected by a nearby VHF radar (31.57MHz, we found that AGW tended to propagate southeastward during FAI events. This result suggests that the interaction between AGW and E-region plasma plays an important role in generating FAI. Furthermore, polarization electric fields generated directly by AGW may contribute to the FAI generation.

    Keywords. Atmospheric composition and structure (Airglow and aurora, Ionosphere (Ionospheric irregularities, Mid-latitude ionosphere

  13. Compact Microwave Fourier Spectrum Analyzer

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry

    2009-01-01

    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  14. Weigh-in-Motion Stations

    Data.gov (United States)

    Department of Homeland Security — The data included in the GIS Traffic Stations Version database have been assimilated from station description files provided by FHWA for Weigh-in-Motion (WIM), and...

  15. Automatic Traffic Recorder (ATR) Stations

    Data.gov (United States)

    Department of Homeland Security — The data included in the GIS Traffic Stations Version database have been assimilated from station description files provided by FHWA for Weigh-in-Motion (WIM), and...

  16. Emergency Medical Service (EMS) Stations

    Data.gov (United States)

    Kansas Data Access and Support Center — EMS Locations in Kansas The EMS stations dataset consists of any location where emergency medical services (EMS) personnel are stationed or based out of, or where...

  17. 21 CFR 1030.10 - Microwave ovens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microwave ovens. 1030.10 Section 1030.10 Food and... ovens. (a) Applicability. The provisions of this standard are applicable to microwave ovens manufactured after October 6, 1971. (b) Definitions. (1) Microwave oven means a device designed to heat, cook, or dry...

  18. Mechanical characterization of microwave sintered zinc oxide

    Indian Academy of Sciences (India)

    The mechanical characterization of microwave sintered zinc oxide disks is reported. The microwave sintering was done with a specially designed applicator placed in a domestic microwave oven operating at a frequency of 2.45 GHz to a maximum power output of 800 Watt. These samples with a wide variation of density ...

  19. Microwave synthesis and mechanical characterization of functionally ...

    Indian Academy of Sciences (India)

    Skin depth of electromagnetic radiation increases with tem- perature and consequently material–microwave interaction increases with temperature. At high temperatures, efficient penetration of microwaves provides sufficient volume for material–microwave interaction and hence substantial vol- umetric heating of metal ...

  20. Project META (Microwave Energy Transmission for Aircraft)

    Science.gov (United States)

    2009-09-01

    viability of using microwave energy transmission technology to power air vehicles remotely was investigated. On-board antennas ( rectennas ) harvest... rectenna to receive microwave energy and convert it to usable DC power. A prototype was designed and experimentally tested under controlled...beamed energy, beaming energy, remotely powered aircraft, rectenna , microwave propulsion 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

  1. Space Station fluid management logistics

    Science.gov (United States)

    Dominick, Sam M.

    1990-01-01

    Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

  2. A Microwave Plasma Closing Switch

    Science.gov (United States)

    Lock Kang, Weng; Rader, Mark; Alexeff, Igor

    1996-11-01

    A microwave plasma closing switch has been constructed using a fluorescent lamp as the central conductor of a coaxial line. When the lamp is energized, the coaxial line transmits microwaves. When the lamp is de-energized, the plasma conductor disappears, and the system reverts to a waveguide beyond cutoff. We have observed up to 61 dB difference in transmission between energized and de-energized operation. A simple model of the line using capacitors, inductors and resistors using the resistance measured in the tube predicts the observed behavior very successfully.

  3. Build Your Own Space Station

    Science.gov (United States)

    Bolinger, Allison

    2016-01-01

    This presentation will be used to educate elementary students on the purposes and components of the International Space Station and then allow them to build their own space stations with household objects and then present details on their space stations to the rest of the group.

  4. Air and radiation monitoring stations

    CERN Multimedia

    AUTHOR|(SzGeCERN)582709

    2015-01-01

    CERN has around 100 monitoring stations on and around its sites. New radiation measuring stations, capable of detecting even lower levels of radiation, were installed in 2014. Two members of HE-SEE group (Safety Engineering and Environment group) in front of one of the new monitoring stations.

  5. A microwave technique for mapping ice temperature in the Arctic seasonal sea ice zone

    Energy Technology Data Exchange (ETDEWEB)

    St. Germain, K.M. [Naval Research Lab., Washington, DC (United States). Remote Sensing Div.; Cavalieri, D.J. [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center

    1997-07-01

    A technique for deriving ice temperature in the Arctic seasonal sea ice zone from passive microwave radiances has been developed. The algorithm operates on brightness temperatures derived from the Special Sensor Microwave/Imager (SSM/I) and uses ice concentration and type from a previously developed thin ice algorithm to estimate the surface emissivity. Comparisons of the microwave derived temperatures with estimates derived from infrared imagery of the Bering Strait yield a correlation coefficient of 0.93 and an RMS difference of 2.1 K when coastal and cloud contaminated pixels are removed. SSM/I temperatures were also compared with a time series of air temperature observations from Gambell on St. Lawrence Island and from Point Barrow, AK weather stations. These comparisons indicate that the relationship between the air temperature and the ice temperature depends on ice type.

  6. Parametric study of microwave-powered high-altitude airplane platforms designed for linear flight

    Science.gov (United States)

    Morris, C. E. K., Jr.

    1981-01-01

    The performance of a class of remotely piloted, microwave powered, high altitude airplane platforms is studied. The first part of each cycle of the flight profile consists of climb while the vehicle is tracked and powered by a microwave beam; this is followed by gliding flight back to a minimum altitude above a microwave station and initiation of another cycle. Parametric variations were used to define the effects of changes in the characteristics of the airplane aerodynamics, the energy transmission systems, the propulsion system, and winds. Results show that wind effects limit the reduction of wing loading and the increase of lift coefficient, two effective ways to obtain longer range and endurance for each flight cycle. Calculated climb performance showed strong sensitivity to some power and propulsion parameters. A simplified method of computing gliding endurance was developed.

  7. Microwave vegetation indices derived from satellite microwave radiometers

    Science.gov (United States)

    Vegetation indices are valuable in many fields of geosciences. Conventional, visible-near infrared, indices are often limited by the effects of atmosphere, background soil conditions, and saturation at high levels of vegetation. In this study, the theoretical basis for a new type of passive microwav...

  8. Southeast Regional Experiment Station

    Science.gov (United States)

    1994-08-01

    This is the final report of the Southeast Regional Experiment Station project. The Florida Solar Energy Center (FSEC), a research institute of the University of Central Florida (UCF), has operated the Southeast Regional Experiment Station (SE RES) for the US Department of Energy (DOE) since September 1982. Sandia National Laboratories, Albuquerque (SNLA) provides technical program direction for both the SE RES and the Southwest Regional Experiment Station (SW RES) located at the Southwest Technology Development Institute at Las Cruces, New Mexico. This cooperative effort serves a critical role in the national photovoltaic program by conducting system evaluations, design assistance and technology transfer to enhance the cost-effective utilization and development of photovoltaic technology. Initially, the research focus of the SE RES program centered on utility-connected PV systems and associated issues. In 1987, the SE RES began evaluating amorphous silicon (a-Si) thin-film PV modules for application in utility-interactive systems. Stand-alone PV systems began receiving increased emphasis at the SE RES in 1986. Research projects were initiated that involved evaluation of vaccine refrigeration, water pumping and other stand-alone power systems. The results of this work have led to design optimization techniques and procedures for the sizing and modeling of PV water pumping systems. Later recent research at the SE RES included test and evaluation of batteries and charge controllers for stand-alone PV system applications. The SE RES project provided the foundation on which FSEC achieved national recognition for its expertise in PV systems research and related technology transfer programs. These synergistic products of the SE RES illustrate the high visibility and contributions the FSEC PV program offers to the DOE.

  9. Submerged AUV Charging Station

    Science.gov (United States)

    Jones, Jack A.; Chao, Yi; Curtin, Thomas

    2014-01-01

    Autonomous Underwater Vehicles (AUVs) are becoming increasingly important for military surveillance and mine detection. Most AUVs are battery powered and have limited lifetimes of a few days to a few weeks. This greatly limits the distance that AUVs can travel underwater. Using a series of submerged AUV charging stations, AUVs could travel a limited distance to the next charging station, recharge its batteries, and continue to the next charging station, thus traveling great distances in a relatively short time, similar to the Old West “Pony Express.” One solution is to use temperature differences at various depths in the ocean to produce electricity, which is then stored in a submerged battery. It is preferred to have the upper buoy submerged a reasonable distance below the surface, so as not to be seen from above and not to be inadvertently destroyed by storms or ocean going vessels. In a previous invention, a phase change material (PCM) is melted (expanded) at warm temperatures, for example, 15 °C, and frozen (contracted) at cooler temperatures, for example, 8 °C. Tubes containing the PCM, which could be paraffin such as pentadecane, would be inserted into a container filled with hydraulic oil. When the PCM is melted (expanded), it pushes the oil out into a container that is pressurized to about 3,000 psi (approx equals 20.7 MPa). When a valve is opened, the high-pressure oil passes through a hydraulic motor, which turns a generator and charges a battery. The low-pressure oil is finally reabsorbed into the PCM canister when the PCM tubes are frozen (contracted). Some of the electricity produced could be used to control an external bladder or a motor to the tether line, such that depth cycling is continued for a very long period of time. Alternatively, after the electricity is generated by the hydraulic motor, the exiting low-pressure oil from the hydraulic motor could be vented directly to an external bladder on the AUV, such that filling of the bladder

  10. Recent Advancements in Microwave Imaging Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    H. Park; C.C. Chang; B.H. Deng; C.W. Domier; A.J.H. Donni; K. Kawahata; C. Liang; X.P. Liang; H.J. Lu; N.C. Luhmann, Jr.; A. Mase; H. Matsuura; E. Mazzucato; A. Miura; K. Mizuno; T. Munsat; K. and Y. Nagayama; M.J. van de Pol; J. Wang; Z.G. Xia; W-K. Zhang

    2002-03-26

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented.

  11. The effect of cloud liquid water on temperature retrievals from microwave measurements

    Science.gov (United States)

    Bernet, Leonie; Navas-Guzmán, Francisco; Kämpfer, Niklaus

    2017-04-01

    Ground-based microwave radiometry provides atmospheric profiles for both clear sky and cloudy weather conditions. The effect of clouds on measurements from microwave radiometers is low compared to other remote sensing techniques but cannot be neglected at certain frequencies. In this study, clouds have been characterized and included in microwave retrievals in order to investigate their effect on tropospheric temperature profiles measured by the TEMPERA microwave radiometer. TEMPERA retrieves atmospheric temperature profiles by measuring emitted radiation of molecular oxygen at around 60 GHz. Because cloud liquid water also absorbs and emits radiation at the used frequency range, it is important to analyse the influence of liquid water on the microwave retrieval. In order to characterize the clouds, data from various instruments have been used, all located at the aerological station of MeteoSwiss at Payerne (Switzerland). Cloud base altitudes were detected using ceilometer measurements while the integrated liquid water (ILW) was measured by a HATPRO radiometer. Additional cloud information was obtained from a co-located sky camera and using an automatic partial cloud amount detection algorithm (APCADA). All this information has been used to characterize the clouds by means of a Liquid Water Content (LWC) profile. Different LWC profiles (shapes and values) have been tested to find the best cloud characterization depending on cloud type, altitude and ILW. Temperature profiles have been obtained incorporating this liquid water profile in the inversion algorithm and they have been evaluated against retrievals without considering clouds, in order to assess the liquid water effect on microwave measurements. The results have been compared with the temperature profiles from radiosondes which are regularly launched twice a day at the aerological station. Two years of data have been analyzed and almost 300 non-precipitating cloud cases were studied. The statistical analysis

  12. Korea Geodetic VLBI Station Sejong

    Science.gov (United States)

    Yi, S.; Moon, Y.; Kim, S.; Lee, J.; Joo, H. e.; Oh, H.

    2012-12-01

    The Sejong VLBI station has been constructed by the National Geographic Information Institute (NGII) in the Republic of Korea. It took approximately four years from 2008 to the end of 2011. In February 2012, we successfully carried out a fringe-test with the Kashima 11-m antenna of the National Institute of Information and Communications Technology (NICT) in Japan. In March, the Sejong station was accepted as an IVS network station by acceptance of the IVS Directing Board which was held at the 7th IVS General Meeting in Spain. This report summarizes activities of the Sejong station as a new IVS Network Station.

  13. Controlled zone microwave plasma system

    Science.gov (United States)

    Ripley, Edward B [Knoxville, TN; Seals, Roland D [Oak Ridge, TN; Morrell, Jonathan S [Knoxville, TN

    2009-10-20

    An apparatus and method for initiating a process gas plasma. A conductive plate having a plurality of conductive fingers is positioned in a microwave applicator. An arc forms between the conductive fingers to initiate the formation of a plasma. A transport mechanism may convey process materials through the plasma. A spray port may be provided to expel processed materials.

  14. Microwave Oven Repair. Teacher Edition.

    Science.gov (United States)

    Smreker, Eugene

    This competency-based curriculum guide for teachers addresses the skills a technician will need to service microwave ovens and to provide customer relations to help retain the customer's confidence in the product and trust in the service company that performs the repair. The guide begins with a task analysis, listing 20 cognitive tasks and 5…

  15. ULTRARAPID VACUUM-MICROWAVE HISTOPROCESSING

    NARCIS (Netherlands)

    KOK, LP; BOON, ME

    A novel histoprocessing method for paraffin sections is presented in which the combination of vacuum and microwave exposure is the key element. By exploiting the decrease in boiling temperature under vacuum, the liquid molecules in the tissues have been successfully extracted and exchanged at

  16. Silicon nitride microwave photonic circuits

    NARCIS (Netherlands)

    Roeloffzen, C.G.H.; Zhuang, L.; Taddei, Caterina; Taddei, Caterina; Leinse, Arne; Heideman, Rene; van Dijk, Paulus W.L.; Oldenbeuving, Ruud; Marpaung, D.A.I.; Burla, M.; Buria, Maurizio; Boller, Klaus J.

    2013-01-01

    We present an overview of several microwave photonic processing functionalities based on combinations of Mach-Zehnder and ring resonator filters using the high index contrast silicon nitride (TriPleXTM) waveguide technology. All functionalities are built using the same basic building blocks, namely

  17. Microwave applicators for BPH thermotherapy

    Science.gov (United States)

    Vrba, Jan; Hlavac, R.; Herza, Jan; Chovanec, Roman; Cvek, Jakub; Oppl, L.

    2004-04-01

    Paper deals with new results in the field of intracavitary microwave applicators used for Benign Prostatic Hyperplasia (BPH) treatment. We demonstrate here that it is necessary to use more sophisticated applicators than a simple monopole radiating structure. One of the good possibilities for safe and efficient treatments we propose here is a helix structure.

  18. Microwave Treatment for Cardiac Arrhythmias

    Science.gov (United States)

    Hernandez-Moya, Sonia

    2009-01-01

    NASA seeks to transfer the NASA developed microwave ablation technology, designed for the treatment of ventricular tachycardia (irregular heart beat), to industry. After a heart attack, many cells surrounding the resulting scar continue to live but are abnormal electrically; they may conduct impulses unusually slowly or fire when they would typically be silent. These diseased areas might disturb smooth signaling by forming a reentrant circuit in the muscle. The objective of microwave ablation is to heat and kill these diseased cells to restore appropriate electrical activity in the heart. This technology is a method and apparatus that provides for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In comparison with other methods that involve direct-current pulses or radio frequencies below 1 GHz, this method may prove more effective in treating ventricular tachycardia. This is because the present method provides for greater control of the location, cross-sectional area, and depth of a lesion via selection of the location and design of the antenna and the choice of microwave power and frequency.

  19. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc bias...

  20. Draper Station Analysis Tool

    Science.gov (United States)

    Bedrossian, Nazareth; Jang, Jiann-Woei; McCants, Edward; Omohundro, Zachary; Ring, Tom; Templeton, Jeremy; Zoss, Jeremy; Wallace, Jonathan; Ziegler, Philip

    2011-01-01

    Draper Station Analysis Tool (DSAT) is a computer program, built on commercially available software, for simulating and analyzing complex dynamic systems. Heretofore used in designing and verifying guidance, navigation, and control systems of the International Space Station, DSAT has a modular architecture that lends itself to modification for application to spacecraft or terrestrial systems. DSAT consists of user-interface, data-structures, simulation-generation, analysis, plotting, documentation, and help components. DSAT automates the construction of simulations and the process of analysis. DSAT provides a graphical user interface (GUI), plus a Web-enabled interface, similar to the GUI, that enables a remotely located user to gain access to the full capabilities of DSAT via the Internet and Webbrowser software. Data structures are used to define the GUI, the Web-enabled interface, simulations, and analyses. Three data structures define the type of analysis to be performed: closed-loop simulation, frequency response, and/or stability margins. DSAT can be executed on almost any workstation, desktop, or laptop computer. DSAT provides better than an order of magnitude improvement in cost, schedule, and risk assessment for simulation based design and verification of complex dynamic systems.

  1. Innovative Railway Stations

    Science.gov (United States)

    Rzepnicka, Sylwia; Załuski, Daniel

    2017-10-01

    In relation to modern demographic trends, evolving technologies and environment-friendly solutions increases the potential of rail considered as sustainable form of public transport. Contemporary tendencies of designing railway stations in Europe are focused on lowering energy consumption and reducing carbon emission. The main goal of the designers is to create a friendly and intuitive space for its users and at the same time a building that uses renewable energy sources and minimizes negative impact on the environment by the increase of biologically active areas, reuse of rainwater and greywater, innovative heating and cooling solutions and reduction of energy losses. The optimisation of a life circle in railway architecture introduces new approach to passenger service. Examples mentioned in the content of this article help to synthesize changes in approach to the design within the context of sustainability.

  2. Study of microwave components for an electron cyclotron resonance ...

    Indian Academy of Sciences (India)

    rious aspects of the microwave system including design, fabrication, characterization and performance studies of the microwave components. Keywords. Microwave system; microwave studio software; network analyser; electron cyclotron resonance ion source. 1. Introduction. Microwave systems at 2.45 GHz have been ...

  3. Microwave SQUID multiplexer demonstration for cosmic microwave background imagers

    Science.gov (United States)

    Dober, B.; Becker, D. T.; Bennett, D. A.; Bryan, S. A.; Duff, S. M.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Hubmayr, J.; Mates, J. A. B.; Reintsema, C. D.; Vale, L. R.; Ullom, J. N.

    2017-12-01

    Key performance characteristics are demonstrated for the microwave superconducting quantum interference device (SQUID) multiplexer (μmux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the μmux produces a white, input referred current noise level of 29 pA/ √{H z } at a microwave probe tone power of -77 dB, which is well below the expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure 98 pA/ √{H z } in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e., phonon) noise. Furthermore, the power spectral density is white over a range of frequencies down to ˜100 mHz, which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the μmux as a viable readout technique for future CMB imaging instruments.

  4. An ambiguity-function-based method for analysis of Doppler decompressed radar signals applied to EISCAT measurements of oblique UHF-VHF meteor echoes

    Science.gov (United States)

    Wannberg, G.; Pellinen-Wannberg, A.; Westman, A.

    1996-05-01

    Binary phase modulation using Barker codes as the modulating sequences is often used as a pulse compression technique in incoherent scatter radar measurements of the ionospheric E region. Demodulation of the compressed signal is usually accomplished by matched filtering techniques. If the target has appreciable velocity, the resulting Doppler shift detunes the scattered signal relative to the filter, and the target response spreads over a large range interval. The paper describes the development of a new data analysis method, based on an ambiguity function description of radar total-power measurements, which uses the characteristic Doppler decompression signatures to identify, extract, and analyze high-velocity events from conventional Barker-coded power profile type incoherent scatter (IS) measurements. Data sets recorded with the European Incoherent Scatter UHF (931 MHz) and VHF (224 MHz) radars during the 1990-1991 Geminid and 1993 Perseid showers are shown to contain many events which are associated with individual meteors crossing the radar beams over a wide range of aspect angles, including a few near-radial cases. Line-of-sight velocities and effective cross sections are derived for some of the best dual radar events. The cross sections are very small and increase with decreasing wavelength, something not observed before. It is suggested that this is indicative of a scattering mechanism different from the one operating at near-normal incidence at VHF, and Rayleigh scatter from compact "balls" of plasma contained within the meteor coma is proposed as a possible candidate, in qualitative agreement with the observations. Finally, some signal-processing related aspects of the method are discussed. It is shown that most IS radars should be able to apply it to their existing programs with very little effort and without having to compromise the performance in normal E region applications. The method could therefore become a powerful tool for studies of meteor

  5. High-resolution observation of field-aligned irregularities in the ionosphere using multi-frequency range imaging of VHF atmospheric radar

    Science.gov (United States)

    Chen, Jenn-Shyong; Furumoto, Jun-ichi; Su, Ching-Lun; Chu, Yen-Hsyang

    Field-aligned irregularity (FAI) in the ionosphere is a topic of interest to atmospheric radar community. In addition to the field-aligned characteristic, quasi-periodic (QP) appearance of FAI echoes has been observed frequently by very-high-frequency (VHF) atmospheric radar. The occurrence range of QP FAI echoes changes with time, and the slope of range versus time can be positive or negative, depending on occurrence time of the echoes. Several mechanisms responsible for the QP FAI echoes have been proposed, e.g., modulation in altitude by a passing atmospheric gravity wave, semidiurnal neutral-wind variation, and so on. Owing to the finite pulse length of radar in observation, the range resolution of measurement is limited within hundreds of meters. In view of this, the range imaging (RIM) using multiple frequencies has been employed to improve the range resolution of measurement. The multi-frequency technique transmits a set of slightly different frequencies sequentially during each radar pulse, and the radar returns at different transmitting frequencies are received, respectively. With adaptive retrieval algorithms for these radar returns, it is capable of resolving the echo structures at meter scale in the range direction. RIM has been employed in the lower atmosphere successfully. In this study, the performance of RIM for FAI was first carried out with the Middle and Upper atmosphere Radar (46 MHz; 34.85(°) N, 136.10(°) N; Japan) and the Chung-Li VHF radar (52 MHz; 24.9(°) N, 121.1(°) E; Taiwan). Some initial results of high-resolution FAI echoes within the range gate will be shown.

  6. Photochemical Assessment Monitoring Stations (PAMS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Photochemical Assessment Monitoring Stations (PAMS). This file provides information on the numbers and distribution (latitude/longitude) of air monitoring sites...

  7. Station History Of The Seismic Station In Ahmadu Bello University ...

    African Journals Online (AJOL)

    The data were used to create the station history plots which display the travel times, the distance time curve and events location on a world seismicity map with Zaria as the center. KEY WORDS: History, Events, Station, Teleseismic, Travel time. Global Journal of Pure and Applied Sciences Vol.11(2) 2005: 309-315.

  8. Methodology of satellite microwave diagnostics of latitudinal-zonal and seasonal variations of frozen soil and sea ice

    Directory of Open Access Journals (Sweden)

    V. V. Melentiev

    2013-01-01

    Full Text Available In the frame of the work we have had investigated the utility of 6.9GHz dual polarization passive microwave data from the sensor AMSR-E for quantitative assessment of spatial and temporal variations of permafrost, seasonally frozen grounds and sea ice properties along the transect 70° E in 2005–2008 years. Analysis of the factors which could be detected with using study of the spatial-temporal variations of the microwave emissivity (brightness temperatures of the system «Earth-atmosphere» was carried out with using in situ data obtained from meteorological stations situated along the investigated transect of the Western Siberia and geocryologic station Marre-Sale (Yamal Peninsula. A new method of visualization of the brightness temperatures in spatial-temporal dimensions was suggested and practical applied. Eight latitudinal zones with intrinsic peculiarities of the spatial and seasonal variability of the brightness temperatures were revealed and investigated in many details. Comparison of the location of these zones with geographic distribution of biomes in Western Siberia was provided and it shows that satellite passive microwave information can be used for classification of the territories inside biomes. In frame of this study the annual brightness temperatures course for tundra zone area has been strictly divided into four periods (seasons characterized by different types of microwave emissivity variations. For boreal needle-leaved forest zone these seasons are manifested weaker. Comprehensive analysis of the satellite microwave survey data and corresponding the in situ data has shown satisfactory correlation between the brightness temperatures of the tundra areas on the Yamal Peninsula and their thermodynamic ground-trough temperatures at the square of geocryologic station Marre-Sale during winter period of stable frozen conditions and vegetation period. In these periods one-channel satellite microwave survey could be applied for the

  9. Magnetic Resonance with Squeezed Microwaves

    Science.gov (United States)

    Bienfait, A.; Campagne-Ibarcq, P.; Kiilerich, A. H.; Zhou, X.; Probst, S.; Pla, J. J.; Schenkel, T.; Vion, D.; Esteve, D.; Morton, J. J. L.; Moelmer, K.; Bertet, P.

    2017-10-01

    Vacuum fluctuations of the electromagnetic field set a fundamental limit to the sensitivity of a variety of measurements, including magnetic resonance spectroscopy. We report the use of squeezed microwave fields, which are engineered quantum states of light for which fluctuations in one field quadrature are reduced below the vacuum level, to enhance the detection sensitivity of an ensemble of electronic spins at millikelvin temperatures. By shining a squeezed vacuum state on the input port of a microwave resonator containing the spins, we obtain a 1.2-dB noise reduction at the spectrometer output compared to the case of a vacuum input. This result constitutes a proof of principle of the application of quantum metrology to magnetic resonance spectroscopy.

  10. Microwave waste processing technology overview

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, R.D.

    1993-02-01

    Applications using microwave energy in the chemical processing industry have increased within the last ten years. Recently, interest in waste treatment applications process development, especially solidification, has grown. Microwave waste processing offers many advantages over conventional waste treatment technologies. These advantages include a high density, leach resistant, robust waste form, volume and toxicity reduction, favorable economics, in-container treatment, good public acceptance, isolated equipment, and instantaneous energy control. The results from the {open_quotes}cold{close_quotes} demonstration scale testing at the Rocky Flats nuclear weapons facility are described. Preliminary results for a transuranic (TRU) precipitation sludge indicate that volume reductions of over 80% are achievable over the current immobilization process. An economic evaluation performed demonstrated cost savings of $11.68 per pound compared to the immobilization process currently in use on wet sludge.

  11. Tapping mode microwave impedance microscopy

    KAUST Repository

    Lai, K.

    2009-01-01

    We report tapping mode microwave impedance imaging based on atomic force microscope platforms. The shielded cantilever probe is critical to localize the tip-sample interaction near the tip apex. The modulated tip-sample impedance can be accurately simulated by the finite-element analysis and the result agrees quantitatively to the experimental data on a series of thin-film dielectric samples. The tapping mode microwave imaging is also superior to the contact mode in that the thermal drift in a long time scale is totally eliminated and an absolute measurement on the dielectric properties is possible. We demonstrated tapping images on working nanodevices, and the data are consistent with the transport results. © 2009 American Institute of Physics.

  12. Latitudinal GRBR-TEC estimation in Southeast Asia region based on the two-station method

    Science.gov (United States)

    Watthanasangmechai, Kornyanat; Yamamoto, Mamoru; Saito, Akinori; Tsugawa, Takuya; Yokoyama, Tatsuhiro; Supnithi, Pornchai; Yatini, Clara Yono

    2014-10-01

    Total electron content (TEC) is an important parameter for revealing latitudinal ionospheric structures, such as the equatorial ionization anomaly (EIA) in Southeast Asia. Understanding the EIA is beneficial for studying equatorial spread F. To reveal the structures, the absolute TEC as a function of latitude must be accurately determined. In early 2012, we expanded a GNU Radio Beacon Receiver (GRBR) network to provide latitudinal coverage in the Thailand-Indonesia sector. We employed the GRBR network to receive VHF and UHF signals from polar low-Earth-orbit satellites. The TEC offset is an unknown parameter in the absolute TEC estimation process. We propose a new technique based on the two-station method to estimate the offset for the latitudinal TEC estimation, and it works better than the original method for a sparse network. The TEC estimation system requires two iterations to minimize the root-mean-square error (RMSE). Once the RMSE reaches the global minimum, the absolute TECs are estimated simultaneously over five GRBR stations. GPS-TECs from local stations are used as the initial guess of the offset estimation. The height of the ionospheric pierce point is determined from the ionosonde hmF2. As a result, the latitudinal GRBR-TEC was successfully estimated from the polar orbit satellites. The two EIA humps were clearly captured by the GRBR-TEC. The result was well verified with the TEC reconstructed from the C/NOFS density data and the ionosonde bottomside data. This is a significant step showing that the GRBR is a useful tool for the study of low-latitude ionospheric features.

  13. Time-of-Flight Microwave Camera.

    Science.gov (United States)

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-10-05

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable "stealth" regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows "camera-like" behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum.

  14. Microwave chemistry for inorganic nanomaterials synthesis.

    Science.gov (United States)

    Bilecka, Idalia; Niederberger, Markus

    2010-08-01

    This Feature Article gives an overview of microwave-assisted liquid phase routes to inorganic nanomaterials. Whereas microwave chemistry is a well-established technique in organic synthesis, its use in inorganic nanomaterials' synthesis is still at the beginning and far away from having reached its full potential. However, the rapidly growing number of publications in this field suggests that microwave chemistry will play an outstanding role in the broad field of Nanoscience and Nanotechnology. This article is not meant to give an exhaustive overview of all nanomaterials synthesized by the microwave technique, but to discuss the new opportunities that arise as a result of the unique features of microwave chemistry. Principles, advantages and limitations of microwave chemistry are introduced, its application in the synthesis of different classes of functional nanomaterials is discussed, and finally expected benefits for nanomaterials' synthesis are elaborated.

  15. Stanwell power station project

    Energy Technology Data Exchange (ETDEWEB)

    Mills, David R; J Dey, Christopher [University of Sidney, Sidney (Australia); Morrison, Graham L [University of New South Wales, Sidney (Australia)

    2000-07-01

    This paper describes the Compact Linear Fresnel Reflector (CLFR) being developed for installation at the Stanwell power station in Queensland Australia. Stanwell Corporation Limited (SCL). Solahart International, Solsearch Pty. Ltd. And the universities of Sidney and New South Wales are cooperating in the project, and this first plant being partly funded by the Australian Greenhouse Office. The solar plant will be attached to a 1440 MW(e) coal fired plant. The 17000 m{sup 2} array will be the largest array in Australia, producing a peak of 13 MW of thermal energy which will offset the use of coal in the generation of electricity. It will use direct steam generation and will feed either steam or hot water at 265 Celsius degrees directly into the power station preheating cycle. The CLFR system, first developed by the University of Sidney and Solsearch Pty. Ltd., is simple and offers small reflector size, low structural cost, fixed receiver geometry. Initial installed plant costs are approximately US$1000 per kWe, but this includes the effect of high up-front design costs and the cost should drop substantially in the second and subsequent plants. [Spanish] Proyecto de la Planta Electrica Stanwell este articulo describe el Reflector Lineal Compacto Fresnel (CLFR, siglas en ingles) que se esta desarrollando para la instalacion de la planta electrica Stanwell en Queensland, Australia. La Corporacion Stanwell Limited (SCL), Solahart International, Solsearch Pty. Ltd., las universidades de Sidney y de New South Wales estan cooperando en este proyecto, y esta primera planta esta parcialmente auspiciada por la Australian Greenhouse Office. La planta solar sera anexa a una planta de carbon de 1440 MW(e). Este arreglo de 17000 m{sup 2} sera el mayor en Australia y producira un maximo de 13 MW en energia termica la cual contrarrestara el uso del carbon en la generacion de electricidad. Utilizara generacion con vapor directo y alimentara ya sea vapor o agua caliente a 265 grados

  16. Note: cryogenic coaxial microwave filters.

    Science.gov (United States)

    Tancredi, G; Schmidlin, S; Meeson, P J

    2014-02-01

    The careful filtering of microwave electromagnetic radiation is critical for controlling the electromagnetic environment for experiments in solid-state quantum information processing and quantum metrology at millikelvin temperatures. We describe the design and fabrication of a coaxial filter assembly and demonstrate that its performance is in excellent agreement with theoretical modelling. We further perform an indicative test of the operation of the filters by making current-voltage measurements of small, underdamped Josephson junctions at 15 mK.

  17. Compact planar microwave blocking filters

    Science.gov (United States)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

    2012-01-01

    A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

  18. Comparing Cosmic Microwave Background Datasets

    OpenAIRE

    Knox, L.; Bond, J..R.; Jaffe, A. H.; Segal, M; Charbonneau, D

    1998-01-01

    To extract reliable cosmic parameters from cosmic microwave background datasets, it is essential to show that the data are not contaminated by residual non-cosmological signals. We describe general statistical approaches to this problem, with an emphasis on the case in which there are two datasets that can be checked for consistency. A first visual step is the Wiener filter mapping from one set of data onto the pixel basis of another. For more quantitative analyses we develop and apply both B...

  19. Directional microwave applicator and methods

    Science.gov (United States)

    Fink, Patrick W. (Inventor); Lin, Greg Y. (Inventor); Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor)

    2008-01-01

    A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095'' (2.4 mm) but the design permits for smaller diameters.

  20. Harmonic distortion in microwave photonic filters.

    Science.gov (United States)

    Rius, Manuel; Mora, José; Bolea, Mario; Capmany, José

    2012-04-09

    We present a theoretical and experimental analysis of nonlinear microwave photonic filters. Far from the conventional condition of low modulation index commonly used to neglect high-order terms, we have analyzed the harmonic distortion involved in microwave photonic structures with periodic and non-periodic frequency responses. We show that it is possible to design microwave photonic filters with reduced harmonic distortion and high linearity even under large signal operation.

  1. Swedish encapsulation station review

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Sven Olof; Brunzell, P.; Heibel, R.; McCarthy, J.; Pennington, C.; Rusch, C.; Varley, G. [NAC International, Zuerich (Switzerland)

    1998-06-01

    In the Encapsulation Station (ES) Review performed by NAC International, a number of different areas have been studied. The main objectives with the review have been to: Perform an independent review of the cost estimates for the ES presented in SKB`s document `Plan 1996`. This has been made through comparisons between the ES and BNFL`s Waste Encapsulation Plant (WEP) at Sellafield as well as with the CLAB facility. Review the location of the ES (at the CLAB site or at the final repository) and its interaction with other parts of the Swedish system for spent fuel management. Review the logistics and plant capacity of the ES. Identify important safety aspects of the ES as a basis for future licensing activities. Based on NAC International`s experience of casks for transport and storage of spent fuel, review the basic design of the copper/steel canister and the transport cask. This review insides design, manufacturing, handling and licensing aspects. Perform an overall comparison between the ES project and the CLAB project with the objective to identify major project risks and discuss their mitigation 19 refs, 9 figs, 35 tabs

  2. TCSP ER-2 MICROWAVE TEMPERATURE PROFILER (MTP) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The TCSP ER-2 Microwave Temperature Profiler (MTP) dataset was collected by the ER-2 Microwave Temperature Profiler (MTP), which is a passive microwave radiometer...

  3. Advanced Microwave Electrothermal Thruster (AMET) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Orbital Technologies Corporation (ORBITEC) and the University of Alabama at Huntsville (UAH) propose to develop the Advanced Microwave Electrothermal Thruster...

  4. Compact superconducting coplanar microwave beam splitters

    Energy Technology Data Exchange (ETDEWEB)

    Baust, Alexander; Haeberlein, Max; Goetz, Jan; Hoffmann, Elisabeth; Menzel, Edwin P.; Schwarz, Manuel J.; Wulschner, Friedrich; Zhong, Ling; Deppe, Frank; Marx, Achim; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TUM, Garching (Germany); Kalb, Norbert; Losinger, Thomas [Physik-Department, TUM, Garching (Germany)

    2012-07-01

    The recent evolution of circuit quantum electrodynamics systems making use of standing-wave microwave modes towards setups for propagating quantum microwaves has triggered the need for low-loss superconducting microwave beam splitters. Such a device should have ports compatible with the coplanar geometry relevant for circuit QED and, at the same time, be compact allowing for scalability. This combination presents fundamental and technological challenges. In this work, we present the fabrication and characterization of various compact superconducting coplanar microwave beam splitters. In addition, we discuss efforts towards a tunable beam splitter.

  5. Use of microwave in diagnostic pathology

    Directory of Open Access Journals (Sweden)

    Basavaradhya Sahukar Shruthi

    2013-01-01

    Microwaves a form of electromagnetic wave-induced heat, when applied in histotechnology, reproducibly yields histolologic material of similar or superior quality to that provided by conventional processing methods, making it more popular in the recent years. A laboratory microwave offers features like maximum output of 2000-3000 watts, an in-built source of adjustable temperature probe, facility for ventilation of hazardous fumes, but is expensive. Considering the usefulness of microwave in histotechnology, i.e., reducing the time required for the diagnosis, replacing the conventional equipments of laboratories by microwave-guided ones is a remarkable and an acceptable change.

  6. Microwave power engineering generation, transmission, rectification

    CERN Document Server

    Okress, Ernest C

    1968-01-01

    Microwave Power Engineering, Volume 1: Generation, Transmission, Rectification considers the components, systems, and applications and the prevailing limitations of the microwave power technology. This book contains four chapters and begins with an introduction to the basic concept and developments of microwave power technology. The second chapter deals with the development of the main classes of high-power microwave and optical frequency power generators, such as magnetrons, crossed-field amplifiers, klystrons, beam plasma amplifiers, crossed-field noise sources, triodes, lasers. The third

  7. Time-of-Flight Microwave Camera

    National Research Council Canada - National Science Library

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-01-01

    .... We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points...

  8. Simple microwave preionization source for ohmic plasmas

    Science.gov (United States)

    Choe, W.; Kwon, Gi-Chung; Kim, Junghee; Kim, Jayhyun; Jeon, Sang-Jean; Huh, Songwhe

    2000-07-01

    A simple economical 2.45 GHz microwave system has been developed and utilized for preionization on the Korea Advanced Institute of Science and Technology (KAIST)-TOKAMAK. The magnetron microwave source was obtained from a widely used, household microwave oven. Since ac operation of the magnetron is not suitable for tokamak application, the magnetron cathode bias circuit was modified to obtain continuous and stable operation of the magnetron for several hundred milliseconds. Application of the developed microwave system to KAIST-TOKAMAK resulted in a reduction of ohmic flux consumption.

  9. AMSR-E/Aqua Monthly Global Microwave Land Surface Emissivity

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set is a global land emissivity product using passive microwave observations from the Advanced Microwave Scanning Radiometer - Earth Observing System...

  10. Behaviors of young children around microwave ovens.

    Science.gov (United States)

    Robinson, Marla R; O'Connor, Annemarie; Wallace, Lindsay; Connell, Kristen; Tucker, Katherine; Strickland, Joseph; Taylor, Jennifer; Quinlan, Kyran P; Gottlieb, Lawrence J

    2011-11-01

    Scald burn injuries are the leading cause of burn-related emergency room visits and hospitalizations for young children. A portion of these injuries occur when children are removing items from microwave ovens. This study assessed the ability of typically developing children aged 15 months to 5 years to operate, open, and remove the contents from a microwave oven. The Denver Developmental Screening Test II was administered to confirm typical development of the 40 subjects recruited. All children recruited and enrolled in this study showed no developmental delays in any domain in the Denver Developmental Screening Test II. Children were observed for the ability to open both a push and pull microwave oven door, to start the microwave oven, and to remove a cup from the microwave oven. All children aged 4 years were able to open the microwaves, turn on the microwave, and remove the contents. Of the children aged 3 years, 87.5% were able to perform all study tasks. For children aged 2 years, 90% were able to open both microwaves, turn on the microwave, and remove the contents. In this study, children as young as 17 months could start a microwave oven, open the door, and remove the contents putting them at significant risk for scald burn injury. Prevention efforts to improve supervision and caregiver education have not lead to a significant reduction in scald injuries in young children. A redesign of microwave ovens might prevent young children from being able to open them thereby reducing risk of scald injury by this mechanism.

  11. 47 CFR 97.109 - Station control.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station control. 97.109 Section 97.109... SERVICE Station Operation Standards § 97.109 Station control. (a) Each amateur station must have at least one control point. (b) When a station is being locally controlled, the control operator must be at the...

  12. 47 CFR 80.519 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 80.519 Section 80.519... MARITIME SERVICES Private Coast Stations and Marine Utility Stations § 80.519 Station identification. (a.... In lieu of the identification of the station by voice, the official call sign may be transmitted by...

  13. 47 CFR 73.787 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Station identification. 73.787 Section 73.787... International Broadcast Stations § 73.787 Station identification. (a) A licensee of an international broadcast station shall make station identification announcement (call letters and location), at the beginning and...

  14. Electromagnetic and microwave absorbing properties of hollow ...

    Indian Academy of Sciences (India)

    Keywords. Nanomaterials; nanospheres; CVD; electric; magnetic; microwave absorption properties. 1. Introduction. In recent years, microwave absorbing materials have attracted considerable attention because it is an essential part of a stealthy defense system for all military platforms, either as aircraft, sea or land vehicles.

  15. Microwave synthesis and mechanical characterization of functionally ...

    Indian Academy of Sciences (India)

    Microwave synthesis and mechanical characterization of functionally graded material for applications in fusion devices ... compact with fine microstructure and good mechanical property has been synthesized by employing microwave heating method at a temperature of 800 °C and in a short processing time of 30 min.

  16. Microwave Accelerated Aza-Claisen Rearrangement

    Directory of Open Access Journals (Sweden)

    Eva Gajdošíková

    2008-11-01

    Full Text Available A study of microwave-induced and standard thermal Overman rearrangement of selected allylic trichloroacetimidates 1a-1f, 6-8 to the corresponding acetamides 2a-2f, 9-11 is reported. The microwave-assisted rearrangement of trifluoroacetimidate 13 is also described. Using this methodology, an efficient access to versatile allylic trihaloacetamides building synthons was established.

  17. An introduction to high power microwaves

    Science.gov (United States)

    Benford, James; Swegle, John

    1992-02-01

    The area of high power microwaves has emerged in recent years as a new technology allowing new applications and offering innovative approaches to existing applications. The great leap in microwave power levels has been driven by a mix of sources that either push conventional microwave device physics in new directions or employ altogether new interaction mechanisms. Running counter to the trend in conventional microwave electronics toward miniaturization with solid-state devices intrinsically limited in their peak power capability, high power microwave generation taps the immense power and energy reservoirs of modern intense relativistic electron beam technology. The term high power microwaves (HPM) is used to denote devices that exceed 100 MW in peak power and span the cm- and mm-wave range of frequencies between 1 and 300 GHz. This definition is arbitrary, but does cleanly divide the conventional microwave devices, which do not exceed 100 MW, from a collection of microwave-generating devices that have now reached powers as high as 15 GW.

  18. Microwave dielectric properties of nanostructured nickel ferrite

    Indian Academy of Sciences (India)

    Wintec

    ... microwave dielectric; co-precipitation. 1. Introduction. Ferrites find wide technological applications in making cores of audio frequency and high frequency transformers, coils (inductors), chokes, permanent magnets, magneto- optical displays, microwave absorbers, wave guides in the. GHz region and chlorine gas sensors ...

  19. Characteristics of microwave propagation in vapourised troposphere ...

    African Journals Online (AJOL)

    Microwave communication equipment design in temperate region may not be very suitable in the tropics because the characteristics of the troposphere as the medium of propagation differ ... The meteorological vertical data taken from radiosonde confirms evidence of super-refraction and ducting of the microwave signal.

  20. Prospects of microwave processing: An overview

    Indian Academy of Sciences (India)

    Administrator

    wave heating. In addition, microwave energy is being explored for the sintering of metal powders also. Ceramic and metal nanopowders have been sintered in microwave. Furthermore, initiatives ... is energy conversion rather than heat transfer. Since micro- .... present review paper provides an overview of the micro- wave ...

  1. Microwave bale moisture sensing: Field trial

    Science.gov (United States)

    A microwave moisture measurement technique was developed for moisture sensing of cotton bales after the bale press. The technique measures the propagation delay of a microwave signal that is transmitted through the cotton bale. This research conducted a field trial to test the sensor in a commercial...

  2. Microwave bale moisture sensing: Field trial continued

    Science.gov (United States)

    A microwave moisture measurement technique was developed at the USDA, ARS Cotton Production and Processing Research Unit for moisture sensing of cotton bales after the bale press. The technique measures the propagation delay of a microwave signal that is transmitted through the cotton bale. This res...

  3. Anisotropy of Wood in the Microwave Region

    Science.gov (United States)

    Ziherl, Sasa; Bajc, Jurij; Urankar, Bernarda; Cepic, Mojca

    2010-01-01

    Wood is transparent for microwaves and due to its anisotropic structure has anisotropic dielectric properties. A laboratory experiment that allows for the qualitative demonstration and quantitative measurements of linear dichroism and birefringence in the microwave region is presented. As the proposed experiments are based on the anisotropy (of…

  4. Microwave remote sensing laboratory design

    Science.gov (United States)

    Friedman, E.

    1979-01-01

    Application of active and passive microwave remote sensing to the study of ocean pollution is discussed. Previous research efforts, both in the field and in the laboratory were surveyed to derive guidance for the design of a laboratory program of research. The essential issues include: choice of radar or radiometry as the observational technique; choice of laboratory or field as the research site; choice of operating frequency; tank sizes and material; techniques for wave generation and appropriate wavelength spectrum; methods for controlling and disposing of pollutants used in the research; and pollutants other than oil which could or should be studied.

  5. Multiband rectenna for microwave applications

    Science.gov (United States)

    Okba, Abderrahim; Takacs, Alexandru; Aubert, Hervé; Charlot, Samuel; Calmon, Pierre-François

    2017-02-01

    This paper reports a multiband rectenna (rectifier + antenna) suitable for the electromagnetic energy harvesting of the spill-over loss of microwave antennas placed on board of geostationary satellites. Such rectenna is used for powering autonomous wireless sensors for satellite health monitoring. The topology of the rectenna is presented. The experimental results demonstrate that the proposed compact rectenna can harvest efficiently the incident electromagnetic energy at three different frequencies that are close to the resonant frequencies of the cross-dipoles implemented in the antenna array. xml:lang="fr"

  6. Simulations of the Microwave Sky

    Energy Technology Data Exchange (ETDEWEB)

    Sehgal, Neelima; /KIPAC, Menlo Park; Bode, Paul; /Princeton U., Astrophys. Sci. Dept.; Das, Sudeep; /Princeton U., Astrophys. Sci. Dept. /Princeton U.; Hernandez-Monteagudo, Carlos; /Garching, Max Planck Inst.; Huffenberger, Kevin; /Miami U.; Lin, Yen-Ting; /Tokyo U., IPMU; Ostriker, Jeremiah P.; /Princeton U., Astrophys. Sci. Dept.; Trac, Hy; /Harvard-Smithsonian Ctr. Astrophys.

    2009-12-16

    We create realistic, full-sky, half-arcminute resolution simulations of the microwave sky matched to the most recent astrophysical observations. The primary purpose of these simulations is to test the data reduction pipeline for the Atacama Cosmology Telescope (ACT) experiment; however, we have widened the frequency coverage beyond the ACT bands and utilized the easily accessible HEALPix map format to make these simulations applicable to other current and near future microwave background experiments. Some of the novel features of these simulations are that the radio and infrared galaxy populations are correlated with the galaxy cluster and group populations, the primordial microwave background is lensed by the dark matter structure in the simulation via a ray-tracing code, the contribution to the thermal and kinetic Sunyaev-Zel'dovich (SZ) signals from galaxy clusters, groups, and the intergalactic medium has been included, and the gas prescription to model the SZ signals has been refined to match the most recent X-ray observations. The cosmology adopted in these simulations is also consistent with the WMAP 5-year parameter measurements. From these simulations we find a slope for the Y{sub 200} - M{sub 200} relation that is only slightly steeper than self-similar, with an intrinsic scatter in the relation of {approx} 14%. Regarding the contamination of cluster SZ flux by radio galaxies, we find for 148 GHz (90 GHz) only 3% (4%) of halos have their SZ decrements contaminated at a level of 20% or more. We find the contamination levels higher for infrared galaxies. However, at 90 GHz, less than 20% of clusters with M{sub 200} > 2.5 x 10{sup 14}M{sub {circle_dot}} and z < 1.2 have their SZ decrements filled in at a level of 20% or more. At 148 GHz, less than 20% of clusters with M{sub 200} > 2.5 x 10{sup 14}M{sub {circle_dot}} and z < 0.8 have their SZ decrements filled in at a level of 50% or larger. Our models also suggest that a population of very high flux

  7. Design of microwave active devices

    CERN Document Server

    Gautier , Jean-Luc

    2014-01-01

    This book presents methods for the design of the main microwave active devices. The first chapter focuses on amplifiers working in the linear mode. The authors present the problems surrounding narrowband and wideband impedance matching, stability, polarization and the noise factor, as well as specific topologies such as the distributed amplifier and the differential amplifier. Chapter 2 concerns the power amplifier operation. Specific aspects on efficiency, impedance matching and class of operation are presented, as well as the main methods of linearization and efficiency improvement. Freq

  8. Stochastic model in microwave propagation

    Energy Technology Data Exchange (ETDEWEB)

    Ranfagni, A. [“Nello Carrara” Institute of Applied Physics, CNR Florence Research Area, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Mugnai, D., E-mail: d.mugnai@ifac.cnr.it [“Nello Carrara” Institute of Applied Physics, CNR Florence Research Area, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy)

    2011-11-28

    Further experimental results of delay time in microwave propagation are reported in the presence of a lossy medium (wood). The measurements show that the presence of a lossy medium makes the propagation slightly superluminal. The results are interpreted on the basis of a stochastic (or path integral) model, showing how this model is able to describe each kind of physical system in which multi-path trajectories are present. -- Highlights: ► We present new experimental results on electromagnetic “anomalous” propagation. ► We apply a path integral theoretical model to wave propagation. ► Stochastic processes and multi-path trajectories in propagation are considered.

  9. Microwave chirality discrimination in enantiomeric liquids

    Science.gov (United States)

    Hollander, E.; Kamenetskii, E. O.; Shavit, R.

    2017-07-01

    Chirality discrimination is of fundamental interest in biology, chemistry, and metamaterial studies. In optics, near-field plasmon-resonance spectroscopy with superchiral probing fields is effectively applicable for analyses of large biomolecules with chiral properties. We show possibility for microwave near-field chirality discrimination analysis based on magnon-resonance spectroscopy. Newly developed capabilities in microwave sensing using magnetoelectric (ME) probing fields originated from multiresonance magnetic-dipolar-mode oscillations in quasi-2D yttrium-iron-garnet disks provide potential for unprecedented measurements of chemical and biological objects. We report on microwave near-field chirality discrimination for aqueous D- and L-glucose solutions. The shown ME-field sensing is addressed to deepen our understanding of microwave-biosystem interactions. It can also be important for an analysis and design of microwave chiral metamaterials.

  10. Quantum teleportation of propagating quantum microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Di Candia, R.; Felicetti, S.; Sanz, M. [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); Fedorov, K.G.; Menzel, E.P. [Bayerische Akademie der Wissenschaften, Walther-Meissner-Institut, Garching (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Zhong, L.; Deppe, F.; Gross, R. [Bayerische Akademie der Wissenschaften, Walther-Meissner-Institut, Garching (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Marx, A. [Bayerische Akademie der Wissenschaften, Walther-Meissner-Institut, Garching (Germany); Solano, E. [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); Basque Foundation for Science, IKERBASQUE, Bilbao (Spain)

    2015-12-15

    Propagating quantum microwaves have been proposed and successfully implemented to generate entanglement, thereby establishing a promising platform for the realisation of a quantum communication channel. However, the implementation of quantum teleportation with photons in the microwave regime is still absent. At the same time, recent developments in the field show that this key protocol could be feasible with current technology, which would pave the way to boost the field of microwave quantum communication. Here, we discuss the feasibility of a possible implementation of microwave quantum teleportation in a realistic scenario with losses. Furthermore, we propose how to implement quantum repeaters in the microwave regime without using photodetection, a key prerequisite to achieve long distance entanglement distribution. (orig.)

  11. Applications of Graphene at Microwave Frequencies

    Directory of Open Access Journals (Sweden)

    M. Bozzi

    2015-09-01

    Full Text Available In view to the epochal scenarios that nanotechnology discloses, nano-electronics has the potential to introduce a paradigm shift in electronic systems design similar to that of the transition from vacuum tubes to semiconductor devices. Since low dimensional (1D and 2D nano-structured materials exhibit unprecedented electro-mechanical properties in a wide frequency range, including radio-frequencies (RF, microwave nano-electronics provides an enormous and yet widely undiscovered opportunity for the engineering community. Carbon nano-electronics is one of the main research routes of RF/microwave nano-electronics. In particular, graphene has shown proven results as an emblematic protagonist, and a real solution for a wide variety of microwave electronic devices and circuits. This paper introduces graphene properties in the microwave range, and presents a paradigm of novel graphene-based devices and applications in the microwave/RF frequency range.

  12. VT Data - Electric Charging Stations

    Data.gov (United States)

    Vermont Center for Geographic Information — Locations of Electric Charging Stations provided by the NREL national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy....

  13. Interior Alaska Gravity Station Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 9416 records. This data base was received in March 1997. Principal gravity parameters include Free-air Anomalies which have been...

  14. WVU Hydrogen Fuel Dispensing Station

    Energy Technology Data Exchange (ETDEWEB)

    Davis, William [West Virginia University Research Corporation, Morgantown, WV (United States)

    2015-09-01

    The scope of this project was changed during the course of the project. Phase I of the project was to construct a site similar to the site at Central West Virginia Regional Airport in Charleston, WV to show that duplication of the site was a feasible method of conducting hydrogen stations. Phase II of the project was necessitated due to a lack of funding that was planned for the development of the station in Morgantown. The US Department of Energy determined that the station in Charleston would be dismantled and moved to Morgantown and reassembled at the Morgantown site. This necessitated storage of the components of the station for almost a year at the NAFTC Headquarters which caused a number of issues with the equipment that will be discussed in later portions of this report. This report will consist of PHASE I and PHASE II with discussions on each of the tasks scheduled for each phase of the project.

  15. Gravity Station Data for Spain

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 28493 records. This data base was received in April 1997. Principal gravity parameters include Free-air Anomalies which have been...

  16. Relation of decorrelated transionospheric GPS signal fluctuations from two stations in the northern anomaly crest region with equatorial ionospheric dynamics

    Science.gov (United States)

    Paul, K. S.; Paul, A.

    2017-05-01

    The ionosphere around the northern crest of the equatorial ionization anomaly (EIA) and beyond exhibits rapid temporal as well as spatial development of ionization density irregularities during postsunset hours. A GPS campaign was conducted during September 2012 and April 2013 from the Institute of Radio Physics and Electronics, Calcutta (22.58°N, 88.38°E geographic; magnetic dip: 32°N), and North Bengal University (NBU), Siliguri (26.72°N, 88.39°E geographic, magnetic dip: 39.49°N) in India in order to assess and quantify differences, if any, in the nature of carrier to noise ratio (C/N0) fluctuations observed on the same satellite link around the same time interval from these stations. Significant decorrelation of the received signals was found when tracking the same satellite vehicle (SV) link from these stations during periods of scintillations. Low values of correlation coefficient of C/N0 at L1 frequency recorded on the same SV link at these two stations were found to correspond with high irregularity characteristic velocities. North-south spatial displacement rates of the impact of ionospheric irregularities were calculated based on coordinated GPS observations which followed an increasing trend with irregularity characteristic velocities measured at VHF. Values of characteristic velocities in excess of 36 m/s were also found to result in large receiver position deviations 3.5-4.0 m during periods of scintillations. Information related to time lag associated with occurrence of scintillations on the same SV link observed from two stations could be useful for improving performance of transionospheric satellite-based position determination techniques.

  17. Conveying International Space Station Science

    Science.gov (United States)

    Goza, Sharon P.

    2017-01-01

    Over 1,000 experiments have been completed, and others are being conducted and planed on the International Space Station (ISS). In order to make the information on these experiments accessible, the IGOAL develops mobile applications to easily access this content and video products to convey high level concepts. This presentation will feature the Space Station Research Explorer as well as several publicly available video examples.

  18. Summit Station Skiway Cost Analysis

    Science.gov (United States)

    2016-07-01

    ER D C/ CR RE L TR -1 6- 9 Engineering for Polar Operations, Logistics , and Research (EPOLAR) Summit Station Skiway Cost Analysis Co ld...and Research (EPOLAR) ERDC/CRREL TR-16-9 July 2016 Summit Station Skiway Cost Analysis Terry D. Melendy Cold Regions Research and Engineering...snapshot at the current operating costs . We collected alternative skiway concepts, such as those at the NEEM camp, from the NEEM logistics and project

  19. Internationalization of the Space Station

    Science.gov (United States)

    Lottmann, R. V.

    1985-01-01

    Attention is given to the NASA Space Station system elements whose production is under consideration by potential foreign partners. The ESA's Columbus Program declaration encompasses studies of pressurized modules, unmanned payload carriers, and ground support facilities. Canada has expressed interest in construction and servicing facilities, solar arrays, and remote sensing facilities. Japanese studies concern a multipurpose experimental module concept. Each of these foreign investments would expand Space Station capabilities and lay the groundwork for long term partnerships.

  20. Space stations systems and utilization

    CERN Document Server

    Messerschmid, Ernst

    1999-01-01

    The design of space stations like the recently launched ISS is a highly complex and interdisciplinary task. This book describes component technologies, system integration, and the potential usage of space stations in general and of the ISS in particular. It so adresses students and engineers in space technology. Ernst Messerschmid holds the chair of space systems at the University of Stuttgart and was one of the first German astronauts.

  1. Tsukuba 32-m VLBI Station

    Science.gov (United States)

    Kawabata, Ryoji; Kurihara, Shinobu; Fukuzaki, Yoshihiro; Kuroda, Jiro; Tanabe, Tadashi; Mukai, Yasuko; Nishikawa, Takashi

    2013-01-01

    The Tsukuba 32-m VLBI station is operated by the Geospatial Information Authority of Japan. This report summarizes activities of the Tsukuba 32-m VLBI station in 2012. More than 200 sessions were observed with the Tsukuba 32-m and other GSI antennas in accordance with the IVS Master Schedule of 2012. We have started installing the observing facilities that will be fully compliant with VLBI2010 for the first time in Japan.

  2. NOVEL SNOW DEPTH RETRIEVAL METHOD USING TIME SERIES SSMI PASSIVE MICROWAVE IMAGERY

    Directory of Open Access Journals (Sweden)

    Z. Nikraftar

    2016-06-01

    Full Text Available The Special Sensor Microwave Imager (SSM/I and the Special Sensor Microwave Imager Sounder (SSM/IS are satellites that work in passive microwave range. The SSM/I has capability to measure geophysical parameters which these parameters are key to investigate the climate and hydrology condition in the world. In this research the SSMI passive microwave data is used to study the feasibility of monitoring snow depth during snowfall month from 2010 to 2015 using an algorithm in conjunction with ground depth measured at meteorological stations of the National Centre for Environmental Information (NCEI. The previous procedures for snow depth retrieval algorithms uses only one or two passive bands for modelling snow depth. This study enable us to use of a nonlinear multidimensional regression algorithm which incorporates all channels and their related weighting coefficients for each band. Higher value of these coefficients are indicator of the importance of each band in the regression model. All channels and their combination were used in support of the vector algorithm combined with genetic algorithm (GA for feature selection to estimate snow depth. The results were compared with those algorithms developed by recent researchers and the results clearly shows the superiority of proposed method (R2 = 0.82 and RMSE = 6.3 cm.

  3. Hyper-energetic manned aerospacecraft propelled by intense pulsed microwave power beam

    Energy Technology Data Exchange (ETDEWEB)

    Myrabo, L.N. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1995-11-01

    The objective of this research was to exploit wireless power transmission (microwave/millimeter)--to lower manned space transportation costs by two or three orders of magnitude. Concepts have been developed for lightweight, mass-producible, beam-propelled aerospacecraft called Lightcraft. The vehicles are designed for a ``mass-poor, energy-rich`` (i.e., hyper-energetic) flight infrastructure which utilizes remote microwave power stations to build an energy-beam highway to space. Although growth in laser power levels has lagged behind expectations, microwave and millimeter-wave source technology now exists for rapid scaling to the megawatt and gigawatt time-average power levels. The design exercise focused on the engine, structure, and receptive optics requirements for a 15 meter diameter, 5 person Earth-to-moon aerospacecraft. Key elements in the air breathing accelerator propulsion system are: (a) a ``flight-weight`` 35GHz rectenna electric powerplant, (b) microwave-induced ``Air Spike`` and perimeter air-plasma generators, and (c) MagnetoHydroDynamic-Fanjet (or MHD-Fanjet) engine with its superconducting magnets and external electrodes.

  4. Hey] What's Space Station Freedom?

    Science.gov (United States)

    Vonehrenfried, Dutch

    This video, 'Hey] What's Space Station Freedom?', has been produced as a classroom tool geared toward middle school children. There are three segments to this video. Segment One is a message to teachers presented by Dr. Jeannine Duane, New Jersey, 'Teacher in Space'. Segment Two is a brief Social Studies section and features a series of Presidential Announcements by President John F. Kennedy (May 1961), President Ronald Reagan (July 1982), and President George Bush (July 1989). These historical announcements are speeches concerning the present and future objectives of the United States' space programs. In the last segment, Charlie Walker, former Space Shuttle astronaut, teaches a group of middle school children, through models, computer animation, and actual footage, what Space Station Freedom is, who is involved in its construction, how it is to be built, what each of the modules on the station is for, and how long and in what sequence this construction will occur. There is a brief animation segment where, through the use of cartoons, the children fly up to Space Station Freedom as astronauts, perform several experiments and are given a tour of the station, and fly back to Earth. Space Station Freedom will take four years to build and will have three lab modules, one from ESA and another from Japan, and one habitation module for the astronauts to live in.

  5. Hey! What's Space Station Freedom?

    Science.gov (United States)

    Vonehrenfried, Dutch

    1992-01-01

    This video, 'Hey! What's Space Station Freedom?', has been produced as a classroom tool geared toward middle school children. There are three segments to this video. Segment One is a message to teachers presented by Dr. Jeannine Duane, New Jersey, 'Teacher in Space'. Segment Two is a brief Social Studies section and features a series of Presidential Announcements by President John F. Kennedy (May 1961), President Ronald Reagan (July 1982), and President George Bush (July 1989). These historical announcements are speeches concerning the present and future objectives of the United States' space programs. In the last segment, Charlie Walker, former Space Shuttle astronaut, teaches a group of middle school children, through models, computer animation, and actual footage, what Space Station Freedom is, who is involved in its construction, how it is to be built, what each of the modules on the station is for, and how long and in what sequence this construction will occur. There is a brief animation segment where, through the use of cartoons, the children fly up to Space Station Freedom as astronauts, perform several experiments and are given a tour of the station, and fly back to Earth. Space Station Freedom will take four years to build and will have three lab modules, one from ESA and another from Japan, and one habitation module for the astronauts to live in.

  6. Cryogenic pulsed inductive microwave magnetometer

    Science.gov (United States)

    Kos, A. B.; Nibarger, J. P.; Lopusnik, R.; Silva, T. J.; Celinski, Z.

    2003-05-01

    A cryogenic pulsed inductive microwave magnetometer is used to characterize the switching dynamics in thin-film magnetic materials at low temperatures and microwave frequencies. The system is contained inside a 20-cm-diam ultrahigh vacuum chamber and cooled by a cryopump that allows measurements between 20 and 350 K. A temperature controller regulates the sample temperature using two silicon diodes as sensors. Applied magnetic fields of up to 36 kA/m (450 Oe) are generated by a four-pole, water-cooled electromagnet with independent control of each axis. Magnetic switching in the sample is driven by high-speed current step pulses in a coplanar waveguide structure with the sample placed in a flip-chip configuration. A 20 GHz sampling oscilloscope is used to record the dynamics of the magnetic reorientation. The switching dynamics are given for a 10-nm-thick Ni-Fe film at 30 K in response to a 1 kA/m field step.

  7. VHF scintillations, orientation of the anisotropy of F-region irregularities and direction of plasma convection in the polar cap

    Directory of Open Access Journals (Sweden)

    E. D. Tereshchenko

    2008-06-01

    Full Text Available Scintillation data recorded at the polar cap station Barentsburg are shown to occasionally exhibit two or more peaks in the latitudinal profiles of the amplitude dispersion. Comparison with concurrent SuperDARN radar convection maps indicates that multiple peaks occur when Barentsburg is located within the area of strong changes in the plasma flow direction. When parameters of the ionospheric irregularities are inferred from the scintillation data, the orientation of the irregularity anisotropy in a plane perpendicular to the magnetic field is found to coincide well with the E×B flow direction, individually for each peak of the scintillation data. The differences were found to be mostly less than 20° for a data set comprised of 104 events. The conclusion is made that analysis of scintillation data allows one to infer the direction of plasma flow with a certain degree of detail.

  8. 47 CFR 73.6016 - Digital Class A TV station protection of TV broadcast stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital Class A TV station protection of TV... Class A TV station protection of TV broadcast stations. Digital Class A TV stations must protect... existing Class A TV station or to change the facilities of a digital Class A TV station will not be...

  9. Study of microwave components for an electron cyclotron resonance ...

    Indian Academy of Sciences (India)

    Keywords. Microwave system; microwave studio software; network analyser; electron cyclotron resonance ion source. ... of ∼13 eV was obtained. This article describes various aspects of the microwave system including design, fabrication, characterization and performance studies of the microwave components.

  10. Microwave Cooking: Knowledge, Attitudes, and Practices of California Foods Teachers.

    Science.gov (United States)

    Stalder, Laura D.; And Others

    1990-01-01

    A survey of 500 California secondary foods teachers (172 responses) indicated their understanding of microwave cooking principles and techniques and positive attitudes toward microwave cooking and safety. A majority used microwave instruction in their classrooms, although many indicated a need for ovens and microwave educational materials. (SK)

  11. Accelerated staining technique using kitchen microwave oven.

    Science.gov (United States)

    Mukunda, Archana; Narayan, T V; Shreedhar, Balasundhari; Shashidhara, R; Mohanty, Leeky; Shenoy, Sadhana

    2015-01-01

    Histopathological diagnosis of specimens is greatly dependent on good sample preparation and staining. Both of these processes is governed by diffusion of fluids and dyes in and out of the tissue, which is the key to staining. Diffusion of fluids can be accelerated by the application of heat that reduces the time of staining from hours to the minute. We modified an inexpensive model of kitchen microwave oven for staining. This study is an attempt to compare the reliability of this modified technique against the tested technique of routine staining so as to establish the kitchen microwave oven as a valuable diagnostic tool. Sixty different tissue blocks were used to prepare 20 pairs of slides for 4 different stains namely hematoxylin and eosin, Van Gieson's, 0.1% toluidine blue and periodic acid-Schiff. From each tissue block, two bits of tissues were mounted on two different slides. One slide was stained routinely, and the other stained inside a microwave. A pathologist evaluated the stained slides and the results so obtained were analyzed statistically. Microwave staining considerably cut down the staining time from hours to seconds. Microwave staining showed no loss of cellular and nuclear details, uniform-staining characteristics and was of excellent quality. The cellular details, nuclear details and staining characteristics of microwave stained tissues were better than or equal to the routine stained tissue. The overall quality of microwave-stained sections was found to be better than the routine stained tissue in majority of cases.

  12. [Eye heating caused by microwave ovens].

    Science.gov (United States)

    Leitgeb, N; Tropper, K

    1993-01-01

    To clarify the question as to whether microwave ovens represent a risk for the eyes, a worst-case situation was investigated in which it was assumed that a child observes the internal heating process with its eyes as close to the door of a microwave oven as it is possible to get. As expected, heating of the eyes was observed, which, however, was caused mainly by the conventional heating process rather than by microwave radiation. Significant microwave heating was observed only when increased scattered radiation was simulated by inactivating the safety contacts and opening the door of the microwave oven. When the door is opened to a clearly visible gap width (2.3 cm), the contribution of the microwave component to the overall temperature increase of 5 degrees C after one hour of continuous exposure did not exceed 16%. Even at the maximum possible door gap width which just did not cause the oven to switch off automatically (2.6 cm), 15 minutes of continuous exposure contributed only 50% to the 2 degrees C temperature increase. On the basis of these results, damage to the eye through the use of microwave ovens can be excluded.

  13. Continuous microwave flow synthesis of mesoporous hydroxyapatite.

    Science.gov (United States)

    Akram, Muhammad; Alshemary, Ammar Z; Goh, Yi-Fan; Wan Ibrahim, Wan Aini; Lintang, Hendrik O; Hussain, Rafaqat

    2015-11-01

    We have successfully used continuous microwave flow synthesis (CMFS) technique for the template free synthesis of mesoporous hydroxyapatite. The continuous microwave flow reactor consisted of a modified 2.45GHz household microwave, peristaltic pumps and a Teflon coil. This cost effective and efficient system was exploited to produce semi-crystalline phase pure nano-sized hydroxyapatite. Effect of microwave power, retention time and the concentration of reactants on the phase purity, degree of crystallinity and surface area of the final product was studied in detail. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to study the phase purity and composition of the product, while transmission electron microscopy (TEM) was used to study the effect of process parameters on the morphology of hydroxyapatite. The TEM analysis confirmed the formation of spherical particles at low microwave power; however the morphology of the particles changed to mesoporous needle and rod-like structure upon exposing the reaction mixture to higher microwave power and longer retention time inside the microwave. The in-vitro ion dissolution behavior of the as synthesized hydroxyapatite was studied by determining the amount of Ca(2+) ion released in SBF solution. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Design of an L-Band Dual Feedhorn for the Purposes of Microwave Search for ExtraTerrensial Intelligence

    Directory of Open Access Journals (Sweden)

    M. Gimersky

    1994-07-01

    Full Text Available Logic behind the design of a dual feedhorn for the 26-meter Cassegrainian antennaof the Agassiz Station-Harvard-Smithsonian Observatory is presented in the paper. Theoretically predicted arid measured results in the "waterhole" band (1.4-1.7 GHz are presented. The antenna has been utilized in the Harvard Wide-Bandwidth HighResolution Microwave Search for ExtraTerrestrial Intelligence (SETI Program, with the Observatory as a SETI-dedicated facility.

  15. The variability of the occurrence of the Field Aligned Irregularities in the middle-latitude F region using the VHF radar observation at Daejon, South Korea.

    Science.gov (United States)

    Oh, S. J.; Kil, H.; Tae-yong, Y.; Kwak, Y. S.; Lee, W. K.

    2016-12-01

    The VHF radar observations at Daejeon in South Korea reveal the highly variable nature of the field-aligned irregularities (FAIs) in the middle-latitude F-region. Medium-scale travelling ionospheric disturbances (MSTIDs) are suggested as the source of FAIs, however, the occurrence climatology of the FAIs cannot be fully explained by the existence of the MSTIDs. Moreover, the occurrence climatology of the FAIs with respect to local time (pre-midnight and post-midnight) likely to have separate onset mechanisms. We investigate the role of the ionospheric disturbances(MSTIDs, Equatorial Plasma Bubbles(EPBs)) in the creation of the FAIs using the radar data at Daejon , the total electron content maps over Japan acquired during 2010-2015. and the measurements of the ion density by Swarm (2014,2015). We assess the causal linkage of the occurrence of the FAIs by examining the correlative occurrence of MSTIDs in middle latitude F-region and EPB in low latitude F-region.

  16. Observations of VHF emissions from 50-mA electron beam injections in the ionosphere that are associated with beam-induced discharges

    Science.gov (United States)

    Goerke, R. T.; Kellogg, P. J.; Monson, S. J.; Franz, R. C.; Nemzek, R. J.; Anderson, H. R.; Potter, D. W.; Denig, W. F.; Szuszczewicz, E. P.; Earle, G. D.

    1992-01-01

    Results are presented of observations of strong VHF plasma waves with amplitudes in excess of 0.1 mV/m (Hz)1/2 associated with 50 mA electron beam injections in the ionosphere. Data from three swept-frequency receivers carried on two daughter payloads are analyzed to determine the emission spectra of the electron beam for various energies and currents. These results were obtained from the rocket-borne experiment SCEX 3, NASA flight 39.002 UE, launched February 1, 1990. The accelerator payload also carried photometers, which measured luminosity at wavelengths of 391.4 and 380.5 nm. Several times during electron gun activity the measured luminosity increased much faster than proportional to the beam current. This nonlinear increase is evidence that a discharge is occurring in the vicinity of the accelerator payload. It is inferred from the uniform distribution of the luminosity around the accelerator payload that the observed discharge extends significantly outside the beam cylinder.

  17. Microwave line of sight link engineering

    CERN Document Server

    Angueira, Pablo

    2012-01-01

    A comprehensive guide to the design, implementation, and operation of line of sight microwave link systems The microwave Line of Sight (LOS) transport network of any cellular operator requires at least as much planning effort as the cellular infrastructure itself. The knowledge behind this design has been kept private by most companies and has not been easy to find. Microwave Line of Sight Link Engineering solves this dilemma. It provides the latest revisions to ITU reports and recommendations, which are not only key to successful design but have changed dramatically in

  18. Heating of matter by microwaves without convection

    OpenAIRE

    Drašković, Draško

    2012-01-01

    This thesis considers heating of matter by means of microwaves. The most common device that uses micro waves for the heating of matter is the microwave oven. Because of the microwave ovens ubiquity and accessibility there are many articles that address the way it works and in how it heats matter. However, it appears that articles contradict each other in their claims that the heating of the matter is either from the inside or from the outside. What actually means »heating the material in the...

  19. RF and microwave coupled-line circuits

    CERN Document Server

    Mongia, R K; Bhartia, P; Hong, J; Gupta, K C

    2007-01-01

    This extensively revised edition of the 1999 Artech House classic, RF and Microwave Coupled-Line Circuits, offers you a thoroughly up-to-date understanding of coupled line fundamentals, explaining their applications in designing microwave and millimeter-wave components used in today's communications, microwave, and radar systems. The Second Edition includes a wealth of new material, particularly relating to applications. You find brand new discussions on a novel simple design technique for multilayer coupled circuits, high pass filters using coupled lines, software packages used for filter des

  20. Microwave filters and circuits contributions from Japan

    CERN Document Server

    Matsumoto, Akio

    1970-01-01

    Microwave Filters and Circuits: Contributions from Japan covers ideas and novel circuits used to design microwave filter that have been developed in Japan, as well as network theory into the field of microwave transmission networks. The book discusses the general properties and synthesis of transmission-line networks; transmission-line filters on the image-parameter basis; and experimental results on a class of transmission-line filter constructed only with commensurate TEM lossless transmission lines. The text describes lines constants, approximation problems in transmission-line networks, as

  1. Effects of microwave radiation on living tissues

    Energy Technology Data Exchange (ETDEWEB)

    Surrell, J.A.; Alexander, R.C.; Cohle, S.D.; Lovell, F.R. Jr.; Wehrenberg, R.A.

    1987-08-01

    Prompted by an alleged case of child abuse resulting from microwave oven burns and the discovery of one other case, an animal model was chosen to explore microwave burn characteristics upon living, perfusing tissue. Anesthetized piglets were exposed to radiation from a standard household microwave oven for varying lengths of time, sufficient to result in full-thickness skin and visceral burns. Characteristic burn patterns were grossly identified. Biopsies studied with both light and electron microscopy demonstrated a pattern of relative layered tissue sparing. Layered tissue sparing is characterized by burned skin and muscle, with relatively unburned subcutaneous fat between these two layers. These findings have important forensic and patient care implications.

  2. Microwave Spectroscopy of Cold Rubidium Atoms

    OpenAIRE

    Entin, V. M.; Ryabtsev, I. I.

    2004-01-01

    The effect of microwave radiation on the resonance fluorescence of a cloud of cold $^{85}Rb$ atoms in a magnetooptical trap is studied. The radiation frequency was tuned near the hyperfine splitting frequency of rubidium atoms in the 5S ground state. The microwave field induced magnetic dipole transitions between the magnetic sublevels of the 5S(F=2) and 5S(F=3) states, resulting in a change in the fluorescence signal. The resonance fluorescence spectra were recorded by tuning the microwave r...

  3. Cesium microwave emission without population inversion.

    Science.gov (United States)

    Levi, F; Godone, A; Vanier, J

    1999-01-01

    The use of coherent population trapping (CPT) for the realization of a Cs coherent microwave emitter without population inversion is described. Preliminary experimental results are reported regarding the radio frequency spectrum of the emitted microwave radiation, the emission profile width, and the transient behavior of the output power. This new approach, based on the coherence properties of the laser radiation, allows the implementation of a microwave frequency standard where the linear light shift is absent and the thermal noise limit for the frequency instability is below 10(-12) for an integration time of 1 s.

  4. Perturbing microwave beams by plasma density fluctuations

    Directory of Open Access Journals (Sweden)

    Köhn Alf

    2017-01-01

    Full Text Available The propagation of microwaves across a turbulent plasma density layer is investigated with full-wave simulations. To properly represent a fusion edge-plasma, drift-wave turbulence is considered based on the Hasegawa-Wakatani model. Scattering and broadening of a microwave beam whose amplitude distribution is of Gaussian shape is studied in detail as a function of certain turbulence properties. Parameters leading to the strongest deterioration of the microwave beam are identified and implications for existing experiments are given.

  5. Microwave-assisted photocatalytic degradation of dimethyl phthalate using a microwave discharged electrodeless lamp

    OpenAIRE

    Liao, Wenchao; Wang, Peng

    2009-01-01

    The microwave-assisted photocatalytic degradation (MW/PC) of dimethyl phthalate (DMP) was investigated, using a microwave discharged electrodeless lamp (MDEL) as the UV source. DMP could be rapidly and completely degraded by the MW/PC process. The effects of photocatalyst dosage, UV light intensity, initial pH and concentration of DMP, as well as irradiation time, were studied in detail. Synergistic effects were found to exist between microwave irradiation and TiO2 photocatalysis, and the gre...

  6. Advanced Microwave Circuits and Systems

    DEFF Research Database (Denmark)

    as sufficient gain in a wide frequency range of operation, which is very difficult to achieve. Most circuits demonstrated are not stable across the frequency band, which makes these amplifiers prone to self-oscillations and therefore limit their applicability. The trade-off between noise figure, gain, linearity......This book is based on recent research work conducted by the authors dealing with the design and development of active and passive microwave components, integrated circuits and systems. It is divided into seven parts. In the first part comprising the first two chapters, alternative concepts...... and equations for multiport network analysis and characterization are provided. A thru-only de-embedding technique for accurate on-wafer characterization is introduced. The second part of the book corresponds to the analysis and design of ultra-wideband low-noise amplifiers (LNA). The LNA is the most critical...

  7. Theory of microwave remote sensing

    Science.gov (United States)

    Tsang, L.; Kong, J. A.; Shin, R. T.

    1985-01-01

    Active and passive microwave remote sensing of earth terrains is studied. Electromagnetic wave scattering and emission from stratified media and rough surfaces are considered with particular application to the remote sensing of soil moisture. Radiative transfer theory for both the random and discrete scatterer models is examined. Vector radiative transfer equations for nonspherical particles are developed for both active and passive remote sensing. Single and multiple scattering solutions are illustrated with applications to remote sensing problems. Analytical wave theory using the Dyson and Bethe-Salpeter equations is employed to treat scattering by random media. The backscattering enhancement effects, strong permittivity fluctuation theory, and modified radiative transfer equations are addressed. The electromagnetic wave scattering from a dense distribution of discrete scatterers is studied. The effective propagation constants and backscattering coefficients are calculated and illustrated for dense media.

  8. Microwave Activation of Drug Release

    DEFF Research Database (Denmark)

    Jónasson, Sævar Þór

    structure that contains fat and muscle tissue mimicking media. The core of the system consists of a single submerged antenna, four external antennas, four transmitters and four receivers, all designed to operate within the ISM-band around 2.45 GHz with a bandwidth of 100 MHz. The wave behaviour inside...... to verify the presence of creeping waves. Due to the inherent high wave attenuation in biological tissues, such as muscles at microwave frequencies, sensitive receiving structures are suggested to be integrated on a drug capsule. The capsules are meant to contain the pharmaceutical drugs and the receiving...... structure is presented to efficiently utilize the available power, to be present at the focusing location. Split-ring resonators are proposed to be integrated on the lid of the capsules which concentrate their acquired power to high-amplitude electric fields across the gaps of the split-ring resonators...

  9. Microwave Imaging Reflectometer for TEXTOR

    Energy Technology Data Exchange (ETDEWEB)

    T. Munsat; E. Mazzucato; H. Park; B.H. Deng; C.W. Domier; N.C. Luhmann, Jr.; J. Wang; Z.G. Xia; A.J.H. Donne; and M. van de Pol

    2002-07-09

    Understanding the behavior of fluctuations in magnetically confined plasmas is essential to the advancement of turbulence-based transport physics. Though microwave reflectometry has proven to be an extremely useful and sensitive tool for measuring small density fluctuations in some circumstances, this technique has been shown to have limited viability for large amplitude, high kq fluctuations and/or core measurements. To this end, a new instrument based on 2-D imaging reflectometry has been developed to measure density fluctuations over an extended plasma region in the TEXTOR tokamak. This technique is made possible by collecting an extended spectrum of reflected waves with large-aperture imaging optics. Details of the imaging reflectometry concept, as well as technical details of the TEXTOR instrument will be presented. Data from roof-of-principle experiments on TEXTOR using a prototype system is presented, as well as results from a systematic off-line study of the advantages and limitations of the imaging reflectometer.

  10. Microwave Impedance Measurement for Nanoelectronics

    Directory of Open Access Journals (Sweden)

    M. Randus

    2011-04-01

    Full Text Available The rapid progress in nanoelectronics showed an urgent need for microwave measurement of impedances extremely different from the 50Ω reference impedance of measurement instruments. In commonly used methods input impedance or admittance of a device under test (DUT is derived from measured value of its reflection coefficient causing serious accuracy problems for very high and very low impedances due to insufficient sensitivity of the reflection coefficient to impedance of the DUT. This paper brings theoretical description and experimental verification of a method developed especially for measurement of extreme impedances. The method can significantly improve measurement sensitivity and reduce errors caused by the VNA. It is based on subtraction (or addition of a reference reflection coefficient and the reflection coefficient of the DUT by a passive network, amplifying the resulting signal by an amplifier and measuring the amplified signal as a transmission coefficient by a common vector network analyzer (VNA. A suitable calibration technique is also presented.

  11. Microwave Radiometry in Remote Sensing

    DEFF Research Database (Denmark)

    Gudmandsen, Preben

    1982-01-01

    an international workshop was organized in June 1982 with the object of reviewing the state-o-the-art in applications and techniques and to suggest future development work in data processing and application, systems principles and performance and in component development including the antenna system....... proves useful for measurement of atmospheric parameters. Examples are detection of rain cells and frontal systems, temperature and humidity profiles and content of minor constituents in the atmosphere foremost above the troposphere. The above examples have been demonstrated from radiometer measurements...... from ballon, aircraft and spacecraft and it is expected that the next generation of spacecraft may encompass microwave radiometers in the frequency range from perhaps 1.4 GHz to 700 GHz taking advantage of a number of new developments. With the purpose of identifying the necessary developments...

  12. Advanced techniques for microwave reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J.; Branas, B.; Luna, E. de la; Estrada, T. [Asociacion Euratom-CIEMAT, Madrid (Spain); Zhuravlev, V. [Asociacion Euratom-CIEMAT, Madrid (Spain)]|[Kurchatov Institute, Moscow (Russian Federation); Hartfuss, H.J.; Hirsch, M.; Geist, T. [Max-Planck Institut fuer Plasmaphysik, Garching (Germany); Segovia, J.; Oramas, J.L. [Univ. Politecnica, Madrid (Spain)

    1994-12-31

    Microwave reflectometry has been applied during the last years as a plasma diagnostic of increasing interest, mainly due to its simplicity, no need for large access ports and low radiation damage of exposed components. Those characteristics make reflectometry an attractive diagnostic for the next generation devices. Systems used either for density profile or density fluctuations have also shown great development, from the original single channel heterodyne to the multichannel homodyne receivers. In the present work we discuss three different advanced reflectometer systems developed by CIEMAT members in collaboration with different institutions. The first one is the broadband heterodyne reflectometer installed on W7AS for density fluctuations measurements. The decoupling of the phase and amplitude of the reflected beam allows for quantitative analysis of the fluctuations. Recent results showing the behavior of the density turbulence during the L-H transition on W7AS are shown. The second system shows how the effect of the turbulence can be used for density profile measurements by reflectometry in situations where the complicated geometry of the waveguides cannot avoid many parasitic reflections. Experiments from the TJ-I tokamak will be shown. Finally, a reflectometer system based on the Amplitude Modulation (AM) technique for density profile measurements is discussed and experimental results from the TJ-I tokamak are shown. The AM system offers the advantage of being almost insensitive to the effect of fluctuations. It is able to take a direct measurement of the time delay of the microwave pulse which propagates to the reflecting layer and is reflected back. In order to achieve fast reconstruction for real time monitoring of the density profile application of Neural Networks algorithms will be presented the method can reduce the computing times by about three orders of magnitude. 10 refs., 10 figs.

  13. Microwave emissions from police radar.

    Science.gov (United States)

    Fink, J M; Wagner, J P; Congleton, J J; Rock, J C

    1999-01-01

    This study evaluated police officers' exposures to microwaves emitted by traffic radar units. Exposure measurements were taken at approximated ocular and testicular levels of officers seated in patrol vehicles. Comparisons were made of the radar manufacturers' published maximum power density specifications and actual measured power densities taken at the antenna faces of those units. Four speed-enforcement agencies and one transportation research institute provided 54 radar units for evaluation; 17 different models, encompassing 4 frequency bands and 3 antenna configurations, were included. Four of the 986 measurements taken exceeded the 5 mW/cm2 limit accepted by the International Radiation Protection Association and the National Council on Radiation Protection and Measurement, though none exceeded the American Conference of Governmental Industrial Hygienists, American National Standards Institute, Institute of Electrical and Electronic Engineers, or Occupational Safety and Health Administration standard of 10 mW/cm2. The four high measurements were maximum power density readings taken directly in front of the radar. Of the 812 measurements taken at the officers' seated ocular and testicular positions, none exceeded 0.04 mW/cm2; the highest of these (0.034 mW/cm2) was less than 1% of the most conservative current safety standards. High exposures in the limited region directly in front of the radar aperture are easily avoided with proper training. Results of this study indicate that police officer exposure to microwave radiation is apparently minimal. However, because of uncertainty in the medical and scientific communities concerning nonionizing radiation, it is recommended that law enforcement agencies implement a policy of prudent avoidance, including purchasing units with the lowest published maximum power densities, purchasing dash/rear deck-mounted units with antennae mounted outside the patrol vehicle, and training police officers to use the "stand-by" mode

  14. Smos Land Product Validation Activities at the Valencia Anchor Station

    Science.gov (United States)

    Lopez-Baeza, Ernesto

    to study the correlation between soil moisture and the Temperature-Vegetation Dryness Index (TVDI), obtained from remote sensing data, which will allow us to produce soil moisture maps for the whole control area. These soil moisture fields will then be compared to those obtained from HIRLAM (HIgh Resolution Limited Area Model ). Complementary to the ground measurements, flight operations will also be performed over the control area using the Helsinki University of Technology TKK Short Skyvan research aircraft. The payload for the SMOS Validation Rehearsal Campaign will consist of the following instruments: (i) L-band radiometer EMIRAD provided by the Technical University of Denmark (TUD), (ii) HUT-2D L-band imaging interferometric radiometer provided by TKK, (iii) PARIS GPS reflectrometry system provided by Institute for Space Studies of Catalonia (IEEC), (iv) IR sensor provided by the Finnish Institute of Maritime Research (FIMR), (v) a low resolution digital video camera Together with the ground soil moisture measurements, other ground and meteorological measurements obtained from the Valencia Anchor Station site will be used to simulate passive microwave brightness temperature so as to have satellite "match ups" for validation purposes and to test retrieval algorithms. The spatialization of the ground measurements up to a SMOS pixel will be carried out by using a Soil-Vegetation-Atmosphere-Transfer (SVAT) model (SUR- FEX) from Mátéo France. Output data, particularly soil moisture, will then used to simulate ee the L-band surface emission through the use of the L-MEB (L-band Microwave Emission of the Biosphere) model. This paper will present an overview of the whole Valencia Anchor Station Experimental Plan making more emphasis on the development of the ground activities which are considered a key element for the performance of the different validation components.

  15. Development of a passive VHF radar system using software-defined radio for equatorial plasma instability studies

    Science.gov (United States)

    Tuysuz, B.; Urbina, J.; Lind, F. D.

    2013-07-01

    In this paper, a bistatic passive radar receiver system named "Coherent-scatter Atmospheric Passive Radar Imager (CAPRI)" is described. It is primarily designed to study the dynamics of the upper atmosphere by utilizing "transmitters of opportunity" as the RF target illuminators. CAPRI is constructed using the open source software-defined radio toolkit, GNU Radio, to meet the signal processing requirements in combination with the open source hardware, Universal Software Radio Peripheral 2, for data acquisition. The resultant system is highly flexible, and we present the details of the design as well as a performance analysis. CAPRI will be deployed in Peru, near the magnetic equator, for long-term operations in the area. FM stations near Lima, Peru, will be utilized with the targets of interest being the equatorial electrojet and the spread F. The results will then be compared to the Jicamarca Unattended Long-term investigations of the Ionosphere and Atmosphere (JULIA) radar data, and CAPRI will be used to improve the simultaneous time and spatial coverage in the region in a more cost-effective manner.

  16. 47 CFR 95.119 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... station identification is the call sign assigned to the GMRS station or system. (c) A unit number may be... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 95.119 Section 95.119... SERVICES General Mobile Radio Service (GMRS) § 95.119 Station identification. (a) Except as provided in...

  17. 47 CFR 73.1201 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Station identification. 73.1201 Section 73.1201... Rules Applicable to All Broadcast Stations § 73.1201 Station identification. (a) When regularly required. Broadcast station identification announcements shall be made: (1) At the beginning and ending of each time...

  18. 47 CFR 25.206 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Station identification. 25.206 Section 25.206... Technical Standards § 25.206 Station identification. The requirement for transmission of station identification is waived for all radio stations licensed under this part with the exception of satellite uplinks...

  19. 47 CFR 95.1305 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 95.1305 Section 95.1305... SERVICES Multi-Use Radio Service (MURS) General Provisions § 95.1305 Station identification. A MURS station is not required to transmit a station identification announcement. ...

  20. 47 CFR 97.119 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 97.119 Section 97.119... SERVICE Station Operation Standards § 97.119 Station identification. (a) Each amateur station, except a... keyed by an automatic device used only for identification, the speed must not exceed 20 words per minute...

  1. 47 CFR 95.1127 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 95.1127 Section 95.1127... SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1127 Station identification. A WMTS station is not required to transmit a station identification announcement. ...

  2. 47 CFR 95.1205 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 95.1205 Section 95.1205... SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1205 Station identification. A station is not required to transmit a station identification announcement. ...

  3. 47 CFR 95.1005 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station identification. 95.1005 Section 95.1005... SERVICES Low Power Radio Service (LPRS) General Provisions § 95.1005 Station identification. An LPRS station is not required to transmit a station identification announcement. ...

  4. Autonomous Electrical Vehicles’ Charging Station

    Directory of Open Access Journals (Sweden)

    Józef Paska

    2016-09-01

    Full Text Available This paper presents a model of an autonomous electrical vehicles’ charging station. It consists of renewable energy sources: wind turbine system, photovoltaic cells, as well as an energy storage, load, and EV charging station. In order to optimise the operating conditions, power electronic converters were added to the system. The model was implemented in the Homer Energy programme. The first part of the paper presents the design assumptions and technological solutions. Further in the paper simulation results are discussed and analysed, and then problems observed in the simulation and possible solutions.

  5. Business earth stations for telecommunications

    Science.gov (United States)

    Morgan, Walter L.; Rouffet, Denis

    The current status of technology for small commercial satellite-communication earth stations is reviewed on the basis of an application study undertaken in the U.S. and Europe. Chapters are devoted to an overview of satellite communication networks, microterminal design and hardware implementation, microterminal applications, the advantages of microterminals, typical users, services provided, the U.S. market for small earth stations, network operators, and the economics of satellite and terrestrial communication services. Consideration is given to the operation of a microterminal network, standards and regulations, technological factors, space-segment requirements, and insurance aspects. Diagrams, graphs, tables of numerical data, and a glossary of terms are provided.

  6. DGPS ground station integrity monitoring

    Science.gov (United States)

    Skidmore, Trent A.; Vangraas, Frank

    1995-01-01

    This paper summarizes the development of a unique Differential Global Positioning System (DGPS) ground station integrity monitor which can offer improved availability over conventional code-differential monitoring systems. This monitoring technique, called code/carrier integrity monitoring (CCIM), uses the highly stable integrated Doppler measurement to smooth the relatively noisy code-phase measurements. The pseudorange correction is therefore comprised of the integrated Doppler measurement plus the CCIM offset. The design and operational results of a DGPS ground station integrity monitor are reported. A robust integrity monitor is realized which is optimized for applications such as the Special Category I (SCAT-I) defined in the RTCA Minimum Aviation System Performance Standards.

  7. Continuous, real time microwave plasma element sensor

    Science.gov (United States)

    Woskov, Paul P.; Smatlak, Donna L.; Cohn, Daniel R.; Wittle, J. Kenneth; Titus, Charles H.; Surma, Jeffrey E.

    1995-01-01

    Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury.

  8. Global Warming and the Microwave Background

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-04-01

    Full Text Available In the work, the importance of assigning the microwave background to the Earth is ad- dressed while emphasizing the consequences for global climate change. Climate mod- els can only produce meaningful forecasts when they consider the real magnitude of all radiative processes. The oceans and continents both contribute to terrestrial emis- sions. However, the extent of oceanic radiation, particularly in the microwave region, raises concerns. This is not only since the globe is covered with water, but because the oceans themselves are likely to be weaker emitters than currently believed. Should the microwave background truly be generated by the oceans of the Earth, our planet would be a much less efficient emitter of radiation in this region of the electromagnetic spectrum. Furthermore, the oceans would appear unable to increase their emissions in the microwave in response to temperature elevation, as predicted by Stefan’s law. The results are significant relative to the modeling of global warming.

  9. Bonding PMMA microfluidics using commercial microwave ovens

    Science.gov (United States)

    Toossi, A.; Moghadas, H.; Daneshmand, M.; Sameoto, D.

    2015-08-01

    In this paper, a novel low-cost, rapid substrate-bonding technique is successfully applied to polymethyl methacrylate (PMMA) microfluidics bonding for the first time. This technique uses a thin intermediate metallic microwave susceptor layer at the interface of the bonding site (microchannels) which produces localized heating required for bonding during microwave irradiation. The metallic susceptor pattern is designed using a multiphysics simulation model developed in ANSYS Multiphysics software (high-frequency structural simulation (HFSS) coupled with ANSYS-Thermal). In our experiments, the required microwave energy for bonding is delivered using a relatively inexpensive, widely accessible commercial microwave oven. Using this technique, simple PMMA microfluidics prototypes are successfully bonded and sealed in less than 35 seconds with a minimum measured bond strength of 1.375 MPa.

  10. A review of microwave oven safety.

    Science.gov (United States)

    Osepchuk, J M

    1978-03-01

    The microwave leakage from current microwave ovens, which are manufactured to meet government emission standards, is reviewed. Typical leakage values imply exposure values well below the most conservative exposure standards in the world. A review of recent developments discloses increasingly stringent government regulation along with advances in techniques for suppression of microwave leakage. The nature of the leakage field is described and studies relating emission to exposure are reviewed. Field survey data are reviewed and it is found that the overwhelming majority of certified ovens in the field show leakage well below permissible limits with an increasing degree of certainty as time goes on. The conclusion is that microwave ovens are not only just as safe as they were in 1973 but they are being accepted as safe under essentially equivalent emission regulations in various countries including those in Eastern Europe.

  11. On-Chip Microwave Quantum Hall Circulator

    Directory of Open Access Journals (Sweden)

    A. C. Mahoney

    2017-01-01

    Full Text Available Circulators are nonreciprocal circuit elements that are integral to technologies including radar systems, microwave communication transceivers, and the readout of quantum information devices. Their nonreciprocity arises from the interference of microwaves over the centimeter scale of the signal wavelength, in the presence of bulky magnetic media that breaks time-reversal symmetry. Here, we realize a completely passive on-chip microwave circulator with size 1/1000th the wavelength by exploiting the chiral, “slow-light” response of a two-dimensional electron gas in the quantum Hall regime. For an integrated GaAs device with 330  μm diameter and about 1-GHz center frequency, a nonreciprocity of 25 dB is observed over a 50-MHz bandwidth. Furthermore, the nonreciprocity can be dynamically tuned by varying the voltage at the port, an aspect that may enable reconfigurable passive routing of microwave signals on chip.

  12. Microwave Imaging for Breast Cancer Detection

    DEFF Research Database (Denmark)

    Rubæk, Tonny; Fhager, Andreas; Jensen, Peter Damsgaard

    2011-01-01

    Still more research groups are promoting microwave imaging as a viable supplement or substitution to more conventional imaging modalities. A widespread approach for microwave imaging of the breast is tomographic imaging in which one seeks to reconstruct the distributions of permittivity and condu......Still more research groups are promoting microwave imaging as a viable supplement or substitution to more conventional imaging modalities. A widespread approach for microwave imaging of the breast is tomographic imaging in which one seeks to reconstruct the distributions of permittivity...... and conductivity in the breast. In this paper two nonlinear tomographic algorithms are compared – one is a single-frequency algorithm and the other is a time-domain algorithm....

  13. Microwave Enhanced Cotunneling in SET Transistors

    DEFF Research Database (Denmark)

    Manscher, Martin; Savolainen, M.; Mygind, Jesper

    2003-01-01

    Cotunneling in single electron tunneling (SET) devices is an error process which may severely limit their electronic and metrologic applications. Here is presented an experimental investigation of the theory for adiabatic enhancement of cotunneling by coherent microwaves. Cotunneling in SET...

  14. Microwave assisted synthesis of some halosubstituted chalcones

    Directory of Open Access Journals (Sweden)

    Abhijit Unchadkar

    2014-07-01

    Full Text Available An efficient microwave assisted synthesis of halosubstituted chalcones by the condensation of halosubstituted ketones and substituted aldehydes. These reactions were found to economically cheap in comparison with classical synthesis.

  15. Microwave Radiometry and Radiometers for Ocean Applications

    DEFF Research Database (Denmark)

    Skou, Niels

    2008-01-01

    aperture radiometer technique, both yielding imaging capability without scanning. Typical applications of microwave radiometry concerning oceans are: sea salinity, sea surface temperature, wind speed and direction, sea ice detection and classification. However, in an attempt to measure properties...

  16. Glass cavity resonators for low microwave frequencies

    Science.gov (United States)

    Howson, D. P.; Hamer, G.

    1995-05-01

    A series of experiments were undertaken to confirm the feasibility of the use of various glasses as walls in microwave cavity resonators with the objective of achieving low drift of resonant frequency with temperature.

  17. RF and microwave microelectronics packaging II

    CERN Document Server

    Sturdivant, Rick

    2017-01-01

    Reviews RF, microwave, and microelectronics assembly process, quality control, and failure analysis Bridges the gap between low cost commercial and hi-res RF/Microwave packaging technologies Engages in an in-depth discussion of challenges in packaging and assembly of advanced high-power amplifiers This book presents the latest developments in packaging for high-frequency electronics. It is a companion volume to “RF and Microwave Microelectronics Packaging” (2010) and covers the latest developments in thermal management, electrical/RF/thermal-mechanical designs and simulations, packaging and processing methods, and other RF and microwave packaging topics. Chapters provide detailed coverage of phased arrays, T/R modules, 3D transitions, high thermal conductivity materials, carbon nanotubes and graphene advanced materials, and chip size packaging for RF MEMS. It appeals to practicing engineers in the electronic packaging and high-frequency electronics domain, and to academic researchers interested in underst...

  18. Microwave Correlation Measurement Crossed-pair Antennas ...

    African Journals Online (AJOL)

    frequency radiometry for obtaining a measurement of the subcutaneous temperature gradient in living tissue. In its simplest form this technique consists of combining the outputs of two antennas feeding a microwave correlation radiometer.

  19. Current Developments of Sparse Microwave Imaging

    Directory of Open Access Journals (Sweden)

    Wu Yi-rong

    2014-08-01

    Full Text Available The sparse microwave imaging combines the sparse signal processing theory with radar imaging to obtain new theory, new system, and new methodology of microwave imaging. In this paper, a brief review of fundamental issues in applying sparse signal processing to radar imaging is provided, including sparse representation, measurement matrix construction, unambiguity reconstruction, and so on. The developments of sparse signal processing in microwave imaging are discussed, and the initial airborne experiments on the prototype Synthetic Aperture Radar (SAR framework with sparse constraints are introduced. The results demonstrate the feasibility and effectiveness of the principle and methodology of sparse microwave imaging. Besides, we also provide an overview of sparse signal processing in various radar applications, including Tomographic SAR (TomoSAR, Inverse SAR (ISAR, Ground Penetrating Radar (GPR as well.

  20. Single-Station Sigma for the Iranian Strong Motion Stations

    Science.gov (United States)

    Zafarani, H.; Soghrat, M. R.

    2017-11-01

    In development of ground motion prediction equations (GMPEs), the residuals are assumed to have a log-normal distribution with a zero mean and a standard deviation, designated as sigma. Sigma has significant effect on evaluation of seismic hazard for designing important infrastructures such as nuclear power plants and dams. Both aleatory and epistemic uncertainties are involved in the sigma parameter. However, ground-motion observations over long time periods are not available at specific sites and the GMPEs have been derived using observed data from multiple sites for a small number of well-recorded earthquakes. Therefore, sigma is dominantly related to the statistics of the spatial variability of ground motion instead of temporal variability at a single point (ergodic assumption). The main purpose of this study is to reduce the variability of the residuals so as to handle it as epistemic uncertainty. In this regard, it is tried to partially apply the non-ergodic assumption by removing repeatable site effects from total variability of six GMPEs driven from the local, Europe-Middle East and worldwide data. For this purpose, we used 1837 acceleration time histories from 374 shallow earthquakes with moment magnitudes ranging from M w 4.0 to 7.3 recorded at 370 stations with at least two recordings per station. According to estimated single-station sigma for the Iranian strong motion stations, the ratio of event-corrected single-station standard deviation ( Φ ss) to within-event standard deviation ( Φ) is about 0.75. In other words, removing the ergodic assumption on site response resulted in 25% reduction of the within-event standard deviation that reduced the total standard deviation by about 15%.

  1. Four decades of microwave satellite soil moisture observations: Part 1. A review of retrieval algorithms

    Science.gov (United States)

    Karthikeyan, L.; Pan, Ming; Wanders, Niko; Kumar, D. Nagesh; Wood, Eric F.

    2017-11-01

    The satellite based passive (radiometer) and active (radar) microwave sensors enhanced our ability to retrieve soil moisture at global scales. It has been almost four decades since the first passive microwave satellite sensor was launched in 1978. Since then soil moisture has gained considerable attention in hydro-meteorological, climate, and agricultural research resulting in the deployment of two dedicated missions in the last decade, SMOS and SMAP. Microwave retrievals require an algorithm to estimate soil moisture from satellite measurements. In this Part 1 of a two-part review series, we provide a synthesis of four decades of research and development on the passive and active microwave soil moisture retrieval algorithms. The algorithms associated with passive sensors use the radiometer brightness temperatures, while active sensors use the radar backscatter measurements to retrieve soil moisture. The physics of both algorithm classes are based on the fact that the microwave measurements at lower frequencies are influenced by the soil dielectric property, which acts as a proxy for the surface soil moisture content. In this review effort, the emphasis is laid on the physical models of the passive and the active retrieval algorithms. These algorithms facilitate to obtain the individual radiative contributions from soil, vegetation, and atmosphere that reach satellite sensors after mixing (roughness), scattering, and attenuation. In the process, we looked into the current research efforts to improve individual aspects of the algorithms, followed by a description of different retrieval procedures. In Part 2 of this review series, performance evaluation and inter-sensor comparisons of soil moisture of eight passive and two active sensors are carried out using 1058 stations along with model soil moisture data in the Contiguous United States (CONUS) region.

  2. Exploring the potential of microwave diagnostics in SEP forecasting: The occurrence of SEP events

    Directory of Open Access Journals (Sweden)

    Zucca Pietro

    2017-01-01

    Full Text Available Solar energetic particles (SEPs, especially protons and heavy ions, may be a space-weather hazard when they impact spacecraft and the terrestrial atmosphere. Forecasting schemes have been developed, which use earlier signatures of particle acceleration to predict the arrival of solar protons and ions in the space environment of the Earth. The UMASEP (University of MAlaga Solar particle Event Predictor scheme forecasts the occurrence and the importance of an SEP event based on combined observations of soft X-rays, their time derivative and protons above 10 MeV at geosynchronous orbit. We explore the possibility to replace the derivative of the soft X-ray time history with the microwave time history in the UMASEP scheme. To this end we construct a continuous time series of observations for a 13-month period from December 2011 to December 2012 at two microwave frequencies, 4.995 and 8.8 GHz, using data from the four Radio Solar Telescope Network (RSTN patrol stations of the US Air Force, and feed this time series to the UMASEP prediction scheme. During the selected period the Geostationary Operational Environmental Satellites (GOES detected nine SEP events related to activity in the western solar hemisphere. We show that the SEP forecasting using microwaves has the same probability of detection as the method using soft X-rays, but no false alarm in the considered period, and a slightly increased warning time. A detailed analysis of the missed events is presented. We conclude that microwave patrol observations improve SEP forecasting schemes that employ soft X-rays. High-quality microwave data available in real time appear as a significant addition to our ability to predict SEP occurrence.

  3. Exploring the potential of microwave diagnostics in SEP forecasting: The occurrence of SEP events

    Science.gov (United States)

    Zucca, P.; Núñez, M.; Klein, K.

    2017-06-01

    Solar energetic particles (SEPs), especially protons and heavy ions, may be a space-weather hazard when they impact spacecraft and the terrestrial atmosphere. Forecasting schemes have been developed, which use earlier signatures of particle acceleration to predict the arrival of solar protons and ions in the space environment of the Earth. The UMASEP (University of MAlaga Solar particle Event Predictor) scheme forecasts the occurrence and the importance of an SEP event based on combined observations of soft X-rays, their time derivative and protons above 10 MeV at geosynchronous orbit. We explore the possibility to replace the derivative of the soft X-ray time history with the microwave time history in the UMASEP scheme. To this end we construct a continuous time series of observations for a 13-month period from December 2011 to December 2012 at two microwave frequencies, 4.995 and 8.8 GHz, using data from the four Radio Solar Telescope Network (RSTN) patrol stations of the US Air Force, and feed this time series to the UMASEP prediction scheme. During the selected period the Geostationary Operational Environmental Satellites (GOES) detected nine SEP events related to activity in the western solar hemisphere. We show that the SEP forecasting using microwaves has the same probability of detection as the method using soft X-rays, but no false alarm in the considered period, and a slightly increased warning time. A detailed analysis of the missed events is presented. We conclude that microwave patrol observations improve SEP forecasting schemes that employ soft X-rays. High-quality microwave data available in real time appear as a significant addition to our ability to predict SEP occurrence.

  4. Adjustable Fiber Optic Microwave Transversal Filters

    Science.gov (United States)

    Shadaram, Mehdi; Lutes, George F.; Logan, Ronald T.; Maleki, Lutfollah

    1994-01-01

    Microwave transversal filters implemented as adjustable tapped fiber optic delay lines developed. Main advantages of these filters (in comparison with conventional microwave transversal filters) are small size, light weight, no need for matching of radio-frequency impedances, no need for shielding against electromagnetic radiation at suboptical frequencies, no need for mechanical tuning, high stability of amplitude and phase, and active control of transfer functions. Weights of taps in fiber optic delay lines adjusted.

  5. Microwave detection of air showers with MIDAS

    Energy Technology Data Exchange (ETDEWEB)

    Facal San Luis, P., E-mail: facal@kicp.uchicago.edu [University of Chicago, Enrico Fermi Institue and Kavli Institute for Cosmological Physics, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Alekotte, I. [Centro Atomico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), 8400 San Carlos de Bariloche, Rio Negro (Argentina); Alvarez, J. [Universidad de Santiago de Compostela, Departamento de Fisica de Particulas, Campus Sur, E-15782 Santiago de Compostela (Spain); Berlin, A. [University of Chicago, Enrico Fermi Institue and Kavli Institute for Cosmological Physics, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Bertou, X. [Centro Atomico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), 8400 San Carlos de Bariloche, Rio Negro (Argentina); Bogdan, M.; Bohacova, M. [University of Chicago, Enrico Fermi Institue and Kavli Institute for Cosmological Physics, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Bonifazi, C. [Univ. Federal do Rio de Janeiro (UFRJ), Instituto de Fisica, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Carvalho, W.R. [Universidad de Santiago de Compostela, Departamento de Fisica de Particulas, Campus Sur, E-15782 Santiago de Compostela (Spain); Mello Neto, J.R.T. de [Univ. Federal do Rio de Janeiro (UFRJ), Instituto de Fisica, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Genat, J.F.; Mills, E.; Monasor, M.; Privitera, P.; Reyes, I.C.; Rouille d& #x27; Orfeuil, B. [University of Chicago, Enrico Fermi Institue and Kavli Institute for Cosmological Physics, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); and others

    2012-01-11

    MIDAS (MIcrowave Detector of Air Showers) is a prototype of a microwave telescope to detect extensive air showers: it images a 20{sup Degree-Sign } Multiplication-Sign 10{sup Degree-Sign} region of the sky with a 4.5 m parabolic reflector and 53 feeds in the focal plane. It has been commissioned in March 2010 and is currently taking data. We present the design, performance and first results of MIDAS.

  6. Continuous microwave regeneration apparatus for absorption media

    Science.gov (United States)

    Smith, Douglas D.

    1999-01-01

    A method and apparatus for continuously drying and regenerating ceramic beads for use in process gas moisture drying operations such as glove boxes. A microwave energy source is coupled to a process chamber to internally heat the ceramic beads and vaporize moisture contained therein. In a preferred embodiment, the moisture laden ceramic beads are conveyed toward the microwave source by a screw mechanism. The regenerated beads flow down outside of the screw mechanism and are available to absorb additional moisture.

  7. Integrated Microwave Photonics for Wideband Signal Processing

    Directory of Open Access Journals (Sweden)

    Xiaoke Yi

    2017-11-01

    Full Text Available We describe recent progress in integrated microwave photonics in wideband signal processing applications with a focus on the key signal processing building blocks, the realization of monolithic integration, and cascaded photonic signal processing for analog radio frequency (RF photonic links. New developments in integration-based microwave photonic techniques, that have high potentialities to be used in a variety of sensing applications for enhanced resolution and speed are also presented.

  8. Theory and design of microwave filters

    CERN Document Server

    Hunter, Ian

    2000-01-01

    This is a thorough, graduate-level text which provides a single source for filter design including basic circuit theory, network synthesis and the design of a variety of microwave filter structures. The aim is to present design theories followed by specific examples with numerical simulations of the designs, with pictures of real devices wherever possible. The book is aimed at designers, engineers and researchers working in microwave electronics who need to design or specify filters.

  9. Weather influence on passive microwave brightness temperatures

    OpenAIRE

    Løvås, Stig M.; Rubinstein, Irene; Ulstad, Christian

    1994-01-01

    Sea ice charts produced using spacebornc passive microwave observations are used on routine basis at several ice forecasting centres and during sea ice research campaigns. The capability of passive microwave sensors to monitor the earth, regardless of cloud cover or daylight, and the 1400 km swath width (SSM/I) make these sensors well suited not only for ice forecasting but also for providing information needed for planning northern oceanic routes. The retrieval of sea ice parameters is carri...

  10. A hospital microwave system for library telecommunication.

    Science.gov (United States)

    Hempel, R M; Ward, B A

    1988-01-01

    The medical library of the Olin E. Teague Veterans' Center needed access to an online integrated library system at a site eighty miles away. The center already operated a tower-to-tower microwave for teleconferencing and the library was able to use this as a temporary means of communication with the distant online system. The microwave link performed satisfactorily, leading to consideration of its use for other library applications. PMID:3224225

  11. Microwaves photonic links components and circuits

    CERN Document Server

    Rumelhard, Christian; Billabert, Anne-Laure

    2013-01-01

    This book presents the electrical models for the different elements of a photonic microwave link like lasers, external modulators, optical fibers, photodiodes and phototransistors. The future trends of these components are also introduced: lasers to VCSEL, external modulators to electro-absorption modulators, glass optical fibers to plastic optical fibers, photodiodes to UTC photodiodes or phototransistors. It also describes an original methodology to evaluate the performance of a microwave photonic link, based on the developed elcetrical models, that can be easily incorporated in

  12. The microwave effects on the properties of alumina at high frequencies of microwave sintering

    Energy Technology Data Exchange (ETDEWEB)

    Sudiana, I. Nyoman, E-mail: sudiana75@yahoo.com; Ngkoimani, La Ode; Usman, Ida [Department of Physics, Faculty of Mathematic and Natural Science, Halu Oleo University, Kampus Bumi Tridharma Anduonohu, Kendari 93232 (Indonesia); Mitsudo, Seitaro; Sako, Katsuhide; Inagaki, Shunsuke [Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui-shi 910-8507 (Japan); Aripin, H. [Center for Material Processing and Renewable Energy, Faculty of Learning Teacher and Education Science, Siliwangi University, Jl. Siliwangi 24 Tasikmalaya 46115, West Java (Indonesia)

    2016-03-11

    Microwave sintering of materials has attracted much research interest because of its significant advantages (e.g. reduced sintering temperatures and soaking times) over the conventional heating. Most researchers compared processes that occurred during the microwave and conventional heating at the same temperature and time. The enhancements found in the former method are indicated as a 'non-thermal effect' which is usually used for explaining the phenomena in microwave processing. Numerous recent studies have been focused on the effect to elucidate the microwave interaction mechanism with materials. Moreover, recent progress on microwave sources such as gyrotrons has opened the possibility for processing materials by using a higher microwave frequency. Therefore, the technology is expected to exhibit a stronger non-thermal effect. This paper presents results from a series of experiments to study the non-thermal effect on microwave sintered alumina. Sintering by using a wide rage of microwave frequencies up to 300 GHz as well as a conventional furnace was carried out. The linear shrinkages of samples for each sintering method were measured. Pores and grains taken from scanning electron microstructure (SEM) images of cut surfaces were also examined. The results of a comparative study of the shrinkages and microstructure evolutions of the sintered samples under annealing in microwave heating systems and in an electric furnace were analyzed. A notably different behavior of the shrinkages and microstructures of alumina after being annealed was found. The results suggested that microwave radiations provided an additional force for mass transports. The results also indicated that the sintering process depended on microwave frequencies.

  13. Microwave calorimetry using X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Nicula, R., E-mail: radu.nicula@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Advanced Materials Processing, Feuerwerkerstr. 39, CH-3602 Thun (Switzerland); Stir, M. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Advanced Materials Processing, Feuerwerkerstr. 39, CH-3602 Thun (Switzerland); Wurm, A. [University of Rostock, Institute of Physics, Wismarsche Str. 43-45, 18051 Rostock (Germany); Catala-Civera, J.M. [Universidad Politecnica de Valencia, Camino Vera s/n, E-46022 Valencia (Spain); Ishizaki, K.; Vaucher, S. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Advanced Materials Processing, Feuerwerkerstr. 39, CH-3602 Thun (Switzerland); Zhuravlev, E.; Schick, C. [University of Rostock, Institute of Physics, Wismarsche Str. 43-45, 18051 Rostock (Germany)

    2011-11-10

    Highlights: Black-Right-Pointing-Pointer New approach for microwave calorimetry using synchrotron radiation powder diffraction. Black-Right-Pointing-Pointer In situ monitoring of the magnetostructural transformation of Co under magnetic microwave heating at 2.45 GHz. Black-Right-Pointing-Pointer Magnetic heat capacity of Co due to the spin-reorientation transition at microwave frequencies. - Abstract: An alternative approach for microwave calorimetry is proposed which relies on the synchrotron radiation powder diffraction technique as well as on the Grueneisen formalism for the analysis of thermal expansion. Cobalt was selected as suitable magnetic material for the present evaluation of the method. First results are reported concerning the calorimetric assessment of the HCP (hexagonal close-packed) to FCC (face centered cubic) transition of cobalt from in situ time-resolved X-ray diffraction experiments performed during magnetic (H-field) microwave heating. The X-ray calorimetry method yields specific heat capacity estimations that compare well with results from conventional differential scanning calorimetry measurements. In the presence of the 2.45 GHz microwave H-field, an 'anomalous' behaviour of the heat capacity across the structural phase transition is detected, which can be correlated with the magnetic spin reorientation transition of cobalt in the same temperature range.

  14. Combination microwave ovens: an innovative design strategy.

    Science.gov (United States)

    Tinga, Wayne R; Eke, Ken

    2012-01-01

    Reducing the sensitivity of microwave oven heating and cooking performance to load volume, load placement and load properties has been a long-standing challenge for microwave and microwave-convection oven designers. Conventional design problem and solution methods are reviewed to provide greater insight into the challenge and optimum operation of a microwave oven after which a new strategy is introduced. In this methodology, a special load isolating and energy modulating device called a transducer-exciter is used containing an iris, a launch box, a phase, amplitude and frequency modulator and a coupling plate designed to provide spatially distributed coupling to the oven. This system, when applied to a combined microwave-convection oven, gives astounding performance improvements to all kinds of baked and roasted foods including sensitive items such as cakes and pastries, with the only compromise being a reasonable reduction in the maximum available microwave power. Large and small metal utensils can be used in the oven with minimal or no performance penalty on energy uniformity and cooking results. Cooking times are greatly reduced from those in conventional ovens while maintaining excellent cooking performance.

  15. Microwave Triggered Laser Ionization of Air

    Science.gov (United States)

    Vadiee, Ehsan; Prasad, Sarita; Jerald Buchenauer, C.; Schamiloglu, Edl

    2012-10-01

    The goal of this work is to study the evolution and dynamics of plasma expansion when a high power microwave (HPM) pulse is overlapped in time and space on a very small, localized region of plasma formed by a high energy laser pulse. The pulsed Nd:YAG laser (8 ns, 600mJ, repetition rate 10 Hz) is focused to generate plasma filaments in air with electron density of 10^17/cm^3. When irradiated with a high power microwave pulse these electrons would gain enough kinetic energy and further escalate avalanche ionization of air due to elastic electron-neutral collisions thereby causing an increased volumetric discharge region. An X-band relativistic backward wave oscillator(RBWO) at the Pulsed Power,Beams and Microwaves laboratory at UNM is constructed as the microwave source. The RBWO produces a microwave pulse of maximum power 400 MW, frequency of 10.1 GHz, and energy of 6.8 Joules. Special care is being given to synchronize the RBWO and the pulsed laser system in order to achieve a high degree of spatial and temporal overlap. A photodiode and a microwave waveguide detector will be used to ensure the overlap. Also, a new shadowgraph technique with a nanosecond time resolution will be used to detect changes in the shock wave fronts when the HPM signal overlaps the laser pulse in time and space.

  16. Fast Drying of Agriculture Commodities by Using Microwave

    Science.gov (United States)

    Ode Ngkoimani, La; Megawati; Purwana Saputra, Gde; Cahyono, Edi; Aripin, Haji; Gde Suastika, Komang; Nyoman Sudiana, I.

    2017-05-01

    Some progress has been made and reported previously due to investigate microwave effects to materials. The microwave applications for material processing by using wide range microwave frequencies such as in sintering, chemical reaction, and drying have been performed. Microwave drying is based on a unique volumetric heating mode with electromagnetic radiation at 2,450 MHz. However, the quest for a what a true microwave effect is still plagued with difficulties. This paper provides a experimental and theoretical analysis of drying materials using microwave. For drying experiments, in this investigation, we were using a domestic microwave oven which operated at three power levels for drying chamber. The samples are agriculture commodity collected from local farmers. The experimental results show that microwave accelerate drying in most materials. The experimental data were analyzed by using an available model constructed from fundamental physics by other scholars. The model has been applied to more understanding the behavior of the microwave drying material.

  17. Microwave applications in neuromorphology and neurochemistry: safety precautions and techniques.

    Science.gov (United States)

    Marani, E

    1998-06-01

    In science, the introduction of a new method is never easy, not even if it concerns the use of a simple microwave oven. Most scientists do not realize the numerous applications of microwave techniques. This paper gives a broad overview of the application of microwave techniques in neuromorphology and neurochemistry, starting with a historical overview ranging from the introduction of microwave techniques as a scientific method in the 1970s to present. Organizations and publication rules are highlighted in the next part. The effect of microwave irradiation is discussed in two sections relating to microwave effects on the whole organism and on the neuron. The main body of the paper discusses the application of microwave techniques in the fields of neuromorphology and neuropathology. The paper then presents aspects of microwave irradiation as applied to ELISA techniques. In addition, cell fusion and cell reproduction under microwave irradiation are discussed. Copyright 1998 Academic Press.

  18. The Medicina Station Status Report

    Science.gov (United States)

    Orfei, Alessandro; Orlati, Andrea; Maccaferri, Giuseppe

    2013-01-01

    General information about the Medicina Radio Astronomy Station, the 32-m antenna status, and the staff in charge of the VLBI observations is provided. In 2012, the data from geodetic VLBI observations were acquired using the Mark 5A recording system with good results. Updates of the hardware were performed and are briefly described.

  19. Mobile Lunar Laser Ranging Station

    Science.gov (United States)

    Intellect, 1977

    1977-01-01

    Harlan Smith, chairman of the University of Texas's Astronomy Department, discusses a mobile lunar laser ranging station which could help determine the exact rates of movement between continents and help geophysicists understand earthquakes. He also discusses its application for studying fundamental concepts of cosmology and physics. (Editor/RK)

  20. Space station molecular sieve development

    Science.gov (United States)

    Chang, C.; Rousseau, J.

    1986-01-01

    An essential function of a space environmental control system is the removal of carbon dioxide (CO2) from the atmosphere to control the partial pressure of this gas at levels lower than 3 mm Hg. The use of regenerable solid adsorbents for this purpose was demonstrated effectively during the Skylab mission. Earlier sorbent systems used zeolite molecular sieves. The carbon molecular sieve is a hydrophobic adsorbent with excellent potential for space station application. Although carbon molecular sieves were synthesized and investigated, these sieves were designed to simulate the sieving properties of 5A zeolite and for O2/N2 separation. This program was designed to develop hydrophobic carbon molecular sieves for CO2 removal from a space station crew environment. It is a first phase effort involved in sorbent material development and in demonstrating the utility of such a material for CO2 removal on space stations. The sieve must incorporate the following requirements: it must be hydrophobic; it must have high dynamic capacity for carbon dioxide at the low partial pressure of the space station atmosphere; and it must be chemiclly stable and will not generate contaminants.