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Sample records for compteur par radio

  1. Radio-controlled automatic gas meter-reading system; Releve automatique de compteur par radio

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, M. [Osaka Gas Co., Ltd (Japan); Ishikawa, K.; Fujiwara, J. [Tokyo Gas Co., Ltd. (Japan); Ichihashi, T. [Toho Gas Co., Ltd. (Japan)

    2000-07-01

    In Japan, an automatic gas meter-reading system is in operation, also incorporating the functions of monitoring for abnormalities in gas use and remote-controlled emergency gas supply shutoff. This system has been realized by linking microcomputer-controlled gas meters(It's called 'Intelligent gas mater') equipped with automatic shutoff mechanism to the gas utility company operation center via communication lines. While the present system uses cable communication lines, we of Tokyo Gas Co., Ltd., Osaka Gas Co., Ltd. and Toho Gas Co., Ltd., have jointly developed a new system based on radio communication. This paper introduces this new system. While radio-controlled meter-reading systems are used in many countries around the world solely for automatic meter reading, our recently developed system is also capable of monitoring for abnormalities in gas use and remote-controlled emergency gas supply shutoff, thanks to its almost real-time two-way communication function. The new system can serve for a period of ten years without recharging. It is also characterized by its applicability as different systems according to purposes: 1) conventional automatic meter-reading system (terminal network control unit or T-NCU), 2) large-scale radio-controlled meter-reading system, and 3) portable terminal-type radio-controlled meter-reading system. (authors)

  2. Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

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    Robert, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection pour un rendement de detection maximal

  3. Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

    Energy Technology Data Exchange (ETDEWEB)

    Robert, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection

  4. The determination of random event-rate based on counter live-time measurement; Determination de la frequence reelle d'evenements aleatoires par comptage et mesure du temps mort du compteur; Opredelenie skorosti scheta besporyadochno sleduyushchikh impul'sov, osnovannoe na izmerenii rabochego vremeni schetchika; Sobre la determinacion del ritmo de sucesos aleatorios basada en la medida del tiempo eficaz de un contador

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    Radeka, V [Institut Rudjer Boskovic, Zagreb, Yugoslavia (Croatia)

    1962-04-15

    The method of determining the true rate of events generated by a random process based on a counting device and live-time measurement is analysed. The determined rate is basically independent of the counter-resolving time. It is shown that the error caused by the resolving time of an event-to-pulse converter at the input of the system is substantially lower than the actual reduction of the rate by the converter itself. Live-time measurement error is discussed with respect to the application limit of the method. The analysis given may be applied to pulse-height analysers and counters using live-time measurement. The method can simply be realized in pulse-height analysers and counters with electronic timers. (author) [French] L'auteur presente une methode de determination de la frequence reelle d'evenements engendres dans un processus aleatoire, par comptage et mesure du temps mort du compteur. La frequence mesuree ne depend pas du temps de resolution du compteur. L'auteur montre que l'erreur due au temps de resolution du convertisseur evenement-impulsion place a l'entree du dispositif est nettement inferieure a la diminution de frequence qu'entraine la conversion. Il discute l'erreur de la mesure du temps mort en ce qui concerne la limite d'application de la methode. Cette analyse peut egalement s'appliquer aux ensembles selecteur d'amplitudes et compteur d'impulsions. La methode peut etre realisee d'une maniere simple dans des ensembles selecteur d'amplitudes et compteur d'impulsions comportant un chronoscope electronique. (author) [Spanish] El autor analiza un metodo para determinar el ritmo verdadero de los impulsos generados por un proceso aleatorio que se basa en el empleo de un dispositivo de contaje y en la medicion del tiempo eficaz. El ritmo determinado es basicamente independiente del tiempo de resolucion del contador. Demuestra que el error ocasionado en la alimentacion del sistema por el tiempo de resolucion de un convertidor de sucesos en impulsos es

  5. Radio-sensitization of animals by bismuth; Radio sensibilisation de l'animal par le bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Pierotti, T; Verain, A [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Digestive absorption of bismuth by animals leads to radio-sensitization. This effect is very marked when the X-rays used are centered on the absorption line of bismuth. This work has involved the use of more than 2000 C3H/JAX mice, and has shown that a maximum lethal effect, with respect to the standard, occurs for bismuth sub-nitrate doses of the order of 3 g/kg and for exposures of 700 R. For stronger or weaker doses, the sensitization effect is less marked. (authors) [French] L'absorption digestive de bismuth provoque une radiosensibilisation de l'animal. Celle-ci est nette quand le rayonnement X utilise est centre sur la raie d'absorption du bismuth. L'etude portant sur plus de 2000 souris C3H/JAX a montre une lethalite maximale par rapport aux temoins pour des doses de sous-nitrate de bismuth de l'ordre de 3 g/kg et pour des expositions de 700 R. Pour des doses plus fortes ou plus faibles, l'effet de sensibilisation est moins net. (auteurs)

  6. The Measurement of Natural Tritium Levels in Geiger Counters; Determination quantitative du tritium naturel par compteurs Geiger; Izmerenie urovnej estestvennogo tritiya v schetchikakh Gejgera; Medicion de concentraciones naturales de tritio mediante contadores Geiger

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, B J [Institute of Nuclear Sciences, Gracefield (New Zealand)

    1962-01-15

    A method for the counting of tritium in a 300 ml gas counter with internal quenching gases is described. Originally a system with ethylene-argon as a quenching gas was used in conjunction with an anticoincidence ring. The anticoincidence count-rate plateau characteristics were unsatisfactory at low count rates because of unsatisfactory quenching, and a search was made for more efficient quenching gases. The source of the background count-rate plateau slope is discussed, and the properties required of a suitable quenching gas for hydrogen counting are given. Results of a study made of the counting characteristics of hydrogen quenched with benzene, ethyl-bromide, ethyl-ether, isopropyl amine, hexane, ethylamine and isoprene are given. Ethylamine and ether in particular gave very satisfactory quenching characteristics. A counting system with a counter filled with 40 cm of hydrogen and quenchcd with ethylamine is described. The background rate is 3 cpm with a comparatively flat background plateau. (author) [French] L'auteur decrit une methode de dosage du tritium au moyen d'un compteur de 300 ml dans lequel on utilise des gaz de coupage internes. Il avait tout d'abord utilise, comme gaz de coupage, un melange d'ethylene et d'argon avec un anneau d'anticoincidence . Mais pour les taux de comptage faibles, les caracteristiques du palier, avec un montage en anticoincidence, n'etaient pas satisfaisantes en raison de l'insuffisance du coupage, et l'auteur a cherche un melange plus efficace. Il analyse la cause de la pente du palier de la courbe du bruit de fond et enumere les proprietes que devrait presenter un gaz de coupage efficace pour le comptage de l'hydrogene. Il donne ensuite les resultats obtenus, au point de vue des caracteristiques du comptage de l'hydrogene, avec les substances de coupage suivantes : benzene, bromure d'ethyle, ether ethylique, isopropylamine, hexane, ethylamine et isoprene. Avec l'ethylamine et l'ether ethylique, les caracteristiques de coupage

  7. The calibration of an end-window counter LCT 13A7 for the measurement of {beta}-activity; Etalonnage d'un compteur cloche LCT 13A7 pour les mesures d'activite {beta}

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    Barthoux, A; Imbert, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The study shows the principal corrections to be applied in the case of plane circular sources made up of a mixture of radio-elements known or unknown. We define the region of activity in which this type of counter can usefully be employed. An experimental curve of the apparent exponential absorption coefficient for {beta} rays in matter is given, thus making it possible to correct for self-absorption and if necessary to define the apparent energy of the radiation. Finally, the study calculates the error to be expected with different counters of the same type. (author) [French] L'etude met en evidence les principales corrections a apporter dans le cas de sources planes circulaires constituees par un melange de radioelements connus ou inconnus. On definit le domaine d'activite dans lequel ce type de compteur peut etre raisonnablement utilise. Une courbe experimentale du coefficient d'absorption exponentielle apparente des {beta} dans la matiere est donnee, permettant d'effectuer des corrections d'autoabsorption et eventuellement de definir l'energie apparente du rayonnement. Enfin, l'etude determine l'erreur a envisager avec differents compteurs du meme type. (auteur)

  8. Measurement of the dead time of a G.M. counter and of the secondary emission of the cathode by the method of the delayed coincidences; Mesure du temps mort d'un compteur G.M. et de l'emission secondaire de la cathode par la methode des coincidences retardees

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    Picard, E; Rogozinski, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1953-07-01

    The dead time of a G.M counter is measured with the method of delayed coincidences. The pulses of the counter that supplies the circuit of coincidences, arrive there, on the one hand, directly, and in the other part, after a known and variable delay. This method permits besides, to study the parasitic impulses coming from the impact of the positive ions on the cathode of the meter. From the results relative to several counters working in various conditions are given. (author) [French] Le temps mort d'un compteur G.M. est mesure a l'aide d'un methode de coincidences retardees. Les impulsions du compteur qui alimentent le circuit de coincidences, y parviennent, d'une part, directement, et, dautre part, apres un retard connu et variable. Cette methode permet de plus, d'etudier les impulsions parasites provenant de l'impact des ions positifs sur la cathode du compteur. Des resultats relatifs a plusieurs compteurs fonctionnant dans des conditions diverses sont donnes. (auteur)

  9. Absolute measurement of {beta} emitters with a 4 {pi} counter; Mesure absolue des emetteurs {beta} au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Le Gallic, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-06-15

    The object of this work is to investigate the conditions under which the activity of {beta}-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 {pi} counter have been examined successively: - comparison of 4 {pi}, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 {pi} counter can be considered a very satisfactory calibration instrument. (author) [French] Le but de ce travail est de rechercher les conditions permettant d'obtenir avec le maximum de precision, la mesure de l'activite des radionuclides se desintegrant par emission et par consequent d'etudier les corrections qui s'y rapportent. Nous avons examine successivement les differents problemes se rapportant aux mesures d'activite au compteur 4 {pi}: - Comparaison des compteurs 4 {pi}, GM et proportionnel; - etude de la preparation des sources; - corrections sur la numeration des sources; - auto-absorption; - correction d'absorption. La precision obtenue dans ces mesures, variant de 1,2 a 3 pour cent, on peut donc considerer le compteur 4 {pi} comme un instrument d'etalonnage tres satisfaisant. (auteur)

  10. Absolute measurement of {beta} emitters with a 4 {pi} counter; Mesure absolue des emetteurs {beta} au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Le Gallic, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-06-15

    The object of this work is to investigate the conditions under which the activity of {beta}-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 {pi} counter have been examined successively: - comparison of 4 {pi}, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 {pi} counter can be considered a very satisfactory calibration instrument. (author) [French] Le but de ce travail est de rechercher les conditions permettant d'obtenir avec le maximum de precision, la mesure de l'activite des radionuclides se desintegrant par emission et par consequent d'etudier les corrections qui s'y rapportent. Nous avons examine successivement les differents problemes se rapportant aux mesures d'activite au compteur 4 {pi}: - Comparaison des compteurs 4 {pi}, GM et proportionnel; - etude de la preparation des sources; - corrections sur la numeration des sources; - auto-absorption; - correction d'absorption. La precision obtenue dans ces mesures, variant de 1,2 a 3 pour cent, on peut donc considerer le compteur 4 {pi} comme un instrument d'etalonnage tres satisfaisant. (auteur)

  11. Liquid Scintillation Detection of Tritium and other Radioisotopes in Insoluble or Quenching Organic Samples; Detection par compteur a scintillations a liquides du tritium et des autres radioelements contenus dans des echantillons organiques insolubles ou coupeurs; Obnaruzhenie tritiya metodom zhidkostnoj stsintillyatsii v nerastvorimykh ili sposo'nykh gasit' izluchenie organicheskikh o'raztsakh; Deteccion del tritio u otros radioisotopos por centelleo liquido en muestras organicas insolubles o que provocan extincion

    Energy Technology Data Exchange (ETDEWEB)

    Eastham, J F; Westbrook, H L; Gonzales, D [University of Tennessee, Knoxville, TN (United States)

    1962-01-15

    To facilitate a study of the H{sup 1}/H{sup 3} isotope effect in the reduction of organic compounds, it has been necessary to develop procedures to overcome the two major limitations of the most convenient general method of radioassaying organic material, liquid scintillation counting. These limitations, which are scintillation-quenching by many organic samples and limited solubility of others, are particularly common with material of biological significance: The procedures developed involve combustion of the sample wrapped in filter paper in art oxygen-filled flask, formation of a solution of the combustion products in a suitable solvent added to the flask before combustion, and scintillation-counting of the solution. Advantages of the developed, procedures, in addition to overcoming the indicated limitations, include efficacy with samples with a great range of activity (some as low as 1{mu}c/mole), good precision (as great as any other general method of radio-assaying H{sup 3}), and applicability to other soft beta emitters (C{sup 14} and S{sup 35}). With a scintillation spectrometer and the techniques developed, samples triply labelled with H{sup 3}, C{sup 14} and S{sup 35} can be differentially radio assayed. Details of the solvent systems and techniques developed are reported. Analytical results are reported for such quenching material as 2.4-dinitrophenyl-hydrazones dyes and for such insoluble materials as proteins and carbohydrates. Application of the techniques to evaluation of H{sup 1}/H{sup 3} isotope effects in certain reduction reactions are discussed. (author) [French] Pour faciliter l'etude de l'effet isotopique ''1H/''3H dans la reduction des composes organiques, il a fallu mettre au point des procedes permettant d'elargir le champ d'application de la methode generale la plus pratique de radioanalyse des matieres organiques, savoir l'analyse au moyen d'un compteur a scintillations a liquides. En effet, ce champ d'application est limite pour deux

  12. New proportional counter for in vivo detection of traces of plutonium in the lungs; Nouveau compteur proportionnel destine a la detection in vivo de traces de plutonium dans les poumons

    Energy Technology Data Exchange (ETDEWEB)

    Morucci, J [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-07-01

    Development of a multi-wire proportional counter having a uniform response over 250 cm{sup 2} thanks to corrections made for boundary effects, and having a low background per sq. cm. due to the use of two identical counters set in anti-coincidence in the same enclosure is described. (author) [French] Etude et mise au point d'un compteur proportionnel multifils de reponse utile homogene sur une surface de 250 cm{sup 2} grace a la correction des effets de bords et de faible mouvement propre par cm{sup 2} grace a deux compteurs identiques montes en anticoincidence dans la meme enceinte. (auteur)

  13. Geiger counters of gamma rays with a bismuth cathode; Compteurs de geiger a rayons gamma a cathode de bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Meunier, R; Legrand, J P [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

    1953-07-01

    Geiger Muller counters present a lake of efficiency of some per cent, for the {gamma} radiations. In the region 0,3 - 1 MeV, a substantial growth of their output can be obtained by a special construction of their cathode. In accordance with previous works, we constructed some counter of formed cathode by a pleated copper wire fencing covered of Bi by electrolysis. The successive modifications brought to a cylindrical conventional cathode in sheet metal of copper, that succeeds to this type of cathode, drive to an improvement of the output. (M.B.) [French] Les compteurs de Geiger Muller presentent une efficacite assez faible de l'ordre de quelques pour cent, pour les rayonnements {gamma}. Dans la region 0,3 - 1 MeV, un accroissement substantiel de leur rendement peut etre obtenu par une construction speciale de leur cathode. Conformement a des travaux anterieurs, nous avons construit des compteurs a cathode formee par un grillage de cuivre plisse recouvert de Bi par electrolyse. Les modifications successives apportees a une cathode conventionnelle cylindrique en tole de cuivre, qui aboutissent a ce type de cathode, conduisent a une amelioration du rendement. (M.B.)

  14. Use of proportional counter in X-Ray spectrometry between 5 and 100 keV. Application to the detection of fission products and to the determination of absolute X-Ray disintegration rates; Utilisation d'un compteur proportionnel en spectrometrie de rayons X entre 5 et 100 keV. Application a la detection des produits de fission et a la determination des taux d'emission X absolus

    Energy Technology Data Exchange (ETDEWEB)

    Cerf, J [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1969-07-01

    The measurement of electromagnetic radiations is difficult in the energy range 20-100 keV. We made suitable for this purpose a regular proportional counter, modifying both the nature and pressure of the gaseous mixture filling the detector volume. We selected the CPEN-SAIP counter, which is able to withstand such modifications. In the energy range considered, the counter is to be standardized with radioactive sources. Such standards were selected according to their disintegration schemes. We thus defined the conditions of use (resolution, yield) of the CPN counter, filled with an argon-methane mixture under a pressure of about 3 bars, in the energy range 5-100 keV. With such an equipment, we were able to measure the absolute disintegration rate for the X-rays of 133 Ba and 75 Se, then to perform the study of a mixed fission products sample. In the same way, we used xenon-based gaseous mixtures, in order to improve the detector yield; in the later case, we carefully examined the limitations introduced by the presence of many parasite rays emitted by the gas. We thus displayed in addition to the leakage peak, the fluorescence ray of the gas, whose origin is difficult to explain. (author) [French] La mesure des rayonnements electromagnetiques est difficile dans une bande d'energie comprise entre 20 et 100 keV environ. Nous avons rendu utilisable, a cet effet, un compteur proportionnel existant en modifiant la nature et la pression du melange gazeux constituant le volume detecteur. De par sa construction, le compteur CPXN, fabrique par les Etablissements S.A.I.P., rend ces experiences possibles. C'est pourquoi nous l'avons choisi. Dans le domaine d'energie consideree l'etalonnage du compteur necessite l'emploi de sources radioactives. Pour les preparer, nous sommes amenes a choisir les radio-nucleides utilisables par l'etude de leur schema de desintegration. Ainsi, nous avons defini les conditions d'utilisation (resolution, efficacite) du compteur CPNX rempli d

  15. Coincidence measurements with the use of detectors measuring the energy of the radiances (proportional meters and scintillation counter); Mesures de coincidences avec utilisation de detecteurs mesurant l'energie des rayonnements (compteurs proportionnels et compteur a scintillations)

    Energy Technology Data Exchange (ETDEWEB)

    Sartory, M [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

    1953-07-01

    In the setting of the realization of a set of installations permitting of the measures of coincidences between sorted radiances according to their energies, an installation understanding a proportional counter and a scintillation counter has been constructed and optimized. It has been used to do some measures of coincidences between X{sub K} photons and photons {gamma} issued at the time of the radioactive transformation of the selenium 75 (electronic capture). The efficiency of the proportional meter has been determined roughly. Besides, a proportional counter of solid angle neighboring of 4{pi} was able to achieve measures of coincidences while only doing one selection of amplitudes: indeed, the simultaneity of the detection of two radiances appear by an impulse whose amplitude is the sum of the amplitudes of the impulses resulting from each of the studied radiations. This method, applied to the coincidences between X-rays, permitted to bring the information on the diagram of decay of the arsenic 73. Besides, the coefficient of internal conversion of a consecutive transition to this decay has been valued. (author) [French] Dans le cadre de la realisation d'une serie de montages permettant des mesures de coincidences entre rayonnements tries d'apres leurs energies, un montage comprenant un compteur proportionnel et un compteur a scintillations a ete construit et mis au point. Il a ete utilise pour effectuer quelques mesures de coincidences entre photons X{sub K} et photons {gamma} emis lors de la transformation radioactive du selenium 75 (capture electronique). L'efficacite du compteur proportionnel a ete approximativement determinee. De plus, un compteur proportionnel d'angle solide voisin de 4{pi} a pu etre utilise pour realiser des mesures de coincidences en n'effectuant qu'une selection d'amplitudes: en effet, la simultaneite de la detection de deux rayonnements se manifeste par une impulsion dont l'amplitude est la somme des amplitudes des impulsions

  16. About the distribution of delays in G.M counters; Sur la distribution des retards dans les compteurs G.M

    Energy Technology Data Exchange (ETDEWEB)

    Picard, E; Rogozinski, A [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

    1954-07-01

    We measure, with an oscillograph method the global time that pass between the time that a particle in a determined region of the studied counter and the answer of the amplifier associated to the counter. This delay is composed of the latency time T{sub l} and the T{sub q} delay, that result from the rise time finished of the impulse and whose value depends of the sensitivity threshold of the amplifier. The selection of (cosmic) particles generating discharge in the studied counter is obtained thanks to a telescope of two meters in coincidence whose opening is limited by a group of four counters in anti-coincidence with the first. The meter is arranged so that the median plan of the telescope crosses to a variable distance d of his axial thread. The measures have been done for different securities of the distance d and of the over-voltage V{sub s} applied to the counter. The results show that the statistical distribution of the delays is more spread especially when d is bigger and V{sub s} more reduced. The average values of the observed delays vary of 7.10{sup -8} s for d = 0 and V{sub s}es = 200 V, to 90.10{sup -8} s for d = 1,9 cm and V{sub s} = 50 V. The mobility of an free electron within the gaseous mixture filling the counter under a pressure of 10 cm.Hg was found equal: (2,1 {+-}0,2).10{sup 4} cm{sup 2}.s{sup -1}.V{sup -1}. (author) [French] On mesure, par une methode oscillographique le temps global qui s'ecoule entre le passage de la particule dans une region determinee du compteur etudie et la reponse de l'amplificateur associe au compteur. Ce retard se compose du temps de latence T{sub l} proprement dit et du retard T{sub q}, qui resulte du temps de montee fini de l'impulsion et dont la valeur depend du seuil de sensibilite de l'amplificateur. La selection des particules (cosmiques) generatrices de la decharge dans le compteur etudie est obtenue grace a un telescope de deux compteurs en coincidence dont l'ouverture est limitee par un groupe de quatre

  17. G.M. counter and pre-determined dead time; Compteur G.M. et temps mort impose

    Energy Technology Data Exchange (ETDEWEB)

    Lamotte, R; Le Baud, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    This paper is divided into two main parts. - The first section recalls the principle on which a G.M. counter works, and examines the factors which lead to inaccuracies in counting. The concept of dead time, although simple risen associated with the counter alone, becomes complicated as soon as an electronic dead time is introduced to meet the demands of a measurement or an experiment. The resulting dead time, due to the coexistence of these dead times created by a single motivating factor, shows up as a function of certain laws of probability. From the analysis of the various cases of possible combinations, the conditions which must be fulfilled by a system with pre-determined dead time may be determined. This leads to a method for measuring the dead time of a G.M. counter, and the possibility of studying the latter under the utilisation conditions foreseen. - In the second part the principle, construction and characteristics of two systems with pre-determined dead time are discussed. To conclude, a comparison of several experimental results justifies an extension of the possibilities of a G.M. counter used in conjunction with such a system. (author) [French] Deux parties essentielles scindent cet expose. - La premiere partie rappelle le principe de fonctionnement d'un compteur G.M. et examine les facteurs d'imprecisions affectant les comptages. La notion de temps mort, simple quand elle est associee au compteur seul, se complique des qu'intervient un temps mort electronique introduit pour les besoins d'une mesure ou d'une experience. Le temps mort resultant, du a la coexistence de ces temps morts engendres par une meme cause, se manifeste en fonction de certaines lois de probabilites. L'analyse des differents cas de combinaisons possibles permet de preciser les imperatifs auxquels doit repondre un systeme a temps mort impose. Il en decoule une methode de mesure du temps mort d'un compteur G.M. et la possibilite d'etudier celui-ci dans les conditions d

  18. Construction and operating characteristics of flexible Geiger counters; Caracteristiques de construction et d'utilisation de compteurs Geiger flexibles; Konstruktsionnaya i operativnaya kharakteristiki gibkikh schetchikov Gejgera; Construccion y caracteristicas de funcionamiento de contadores Geiger flexibles

    Energy Technology Data Exchange (ETDEWEB)

    Richter, H G; Ballard, L F [Research Triangle Institute, Durham, NC (United States)

    1962-04-15

    point une methode de construction de compteurs Geiger flexibles ayant des dimensions tres variees. Les compteurs sont tres flexibles : un compteur de 3 cm de diametre peut etre plie avec un rayon de courbure de 5 cm. En utilisant du gaz Q (98,3% d'helium et 1,7% de n-butane) comme milieu de comptage, les paliers ont une longueur de plusieurs centaines de volts avec une pente de 3% et sont independants de la configuration geometrique du compteur. Les compteurs sont construits avec des tubes en chlorure de polyvinyle (PVC-744 - Alpha Wire Corp.). De courts segments du tube (longueur egale a environ 3 fois le diametre) sont glisses sur un mandrin d'aluminium grossierement filete et entoures d'un fil fortement serre. Le tout est place dans un four a 110{sup o}C pendant 20 minutes. Apres refroidissement, le segment de matiere plastique ainsi cannele est degage du mandrin. Ce traitement du tube empeche sa rupture lorsqu'il est enroule. Un disque de polystyrene, perfore de trous relativement grands a la peripherie pour l'ecoulement du gaz et d'un trou central de 0,6 mm pour le passage de l'anode, est attache a une extremite de chaque segment. En enfilant les segments ainsi prepares sur une anode en tungstene de 3 mm, en glissant une extremite de chaque segment sur le segment adjacent et en les fixant solidement avec un adhesif, on peut construire un compteur d'une longueur quelconque. On attache aux extremites des pieces en verre pour la fixation de l'anode et pour l'admission et l'evacuation du gaz. Un fil de cuivre nu, entoure en spirale dans les cannelures du compteur, donne une cathode externe satisfaisante, qui fonctionne suivant le mode observe par Maze. Un compteur de 3 cm de diametre et de 1 metre de longueur, lineaire ou enroule, possede un palier commencant a 1400 volts et allant jusqu'a 1700 volts avec une pente de 2,9%. On a enregistre des taux de comptage de plus de 300000 coups par minute, avec peu de pertes par coincidences. Comme le compteur est en fait une

  19. Radio Column Chromatographic Assay of H{sup 3}-Labelled Substances; Analyse par radiochromatographie en colonne, de substances marquees par le tritium; Radiokhromatograficheskoe ispytanie mechennykh tritiem veshchestv na kolonke; Analisis por radiocromatografia en columna de sustancias marcadas con {sup 3}H

    Energy Technology Data Exchange (ETDEWEB)

    Scharpenseel, H W; Menke, K H [Institute of Soil Science and Institute of Animal Husbandry, Bonn University, Bonn (Germany)

    1962-01-15

    between the analyser- and monitor-phototubes. In order to ensure a laminar flow and constantly mixed volume ratio, dose-pumps are lised for the supply of buffer on the column and of the 30-fold volume of toluene/ethanol. The counting efficiency for H{sup 3} averages 2.5-4% for'coils spreading over the whole diameter of the phototubes. 3. The aqeous column effluent is led through an anthracene-filled glass tube and the H{sup 3} counted with close to l{sup o}/o efficiency. (author) [French] Dans la majorite des cas, les recherches radiochromatographique s combinees portant sur des substances marquees par {sup 3}H font partie integrante des experiences biochimiques utilisant des composes trities. Avec un ensemble comprenant un compteur a balayage continu sans fenetre, le comptage du tritium par radiochromatographi e sur papier est d'un rendement de 0,5 a 1,5%, qui depend dans une large mesure de l'epaisseur du papier et de l'autoabsorption dans le compose marque. La radiochromatographie en phase gazeuse des composes trities ne presente pas davantage de difficultes serieuses. On utilise avec succes un ensemble de chromatographic en phase gazeuse comportant une chambre d'ionisation a courant et un electrometre a lame vibrante - concu par K. E. Wilzbach et P. Riesz et perfectionne par H. Dutton, L. Mason et L. Blair. Grace a l'emploi de ''Teflon'' et de caoutchouc de silicones pour les elements isolants de la chambre d'ionisation, cet ensemble peut fonctionner a des temperatures voisines de 300{sup o}C. Avec le tritium, la radiochromatographi e en colonne donne des resultats mediocres, si le liquide sortant de la colonne se repand en une couche mince et passe lentement sous un compteur a balayage continu sans fenetre ou un compteur a scintillations, alors que le meme procede a donne d'excellente resultats avec le carbone-14. Aussi est-il probable que l'on adoptera la spectrometrie a scintillations en phase liquide. Elle comporte essentiellement deux procedes differents, que les

  20. 4{pi} proportional counter for absolute measurement of {beta}-emitters; Compteur 4{pi} proportionnel destine a la mesure absolue d'emetteurs {beta}

    Energy Technology Data Exchange (ETDEWEB)

    Perolat, J P; Laine, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The 4{pi} counter is commonly used to measure the activity of {beta} sources, the one we describe does not advance a new conception but the issue of several years of investigations. The apparatus presents good performances about the qualities commonly required in that kind of counter: detection efficiency, plateau and dead time. Moreover technical characteristics give a great flexibility in use, particularly a possibility of adaptation in a {beta},{gamma} coincidence unit. (authors) [French] Le compteur 4{pi} proportionnel est couramment, utilise pour mesurer l'activite de sources {beta}, celui que nous decrivons ne represente pas une conception nouvelle, mais plutot l'aboutissement de plusieurs annees d'etudes. Cette installation presente des performances satisfaisantes en ce qui concerne les qualites habituellement requises dans ce type de compteur: l'efficacite de detection, le palier et le temps mort. En outre, certaines caracteristiques techniques qui lui sont propres lui conferent une grande souplesse d'utilisation, en particulier la possibilite d'adaptation a un ensemble de mesures par coincidences 4{pi} {beta} {gamma}. (auteurs)

  1. Radio-vulcanization of natural rubber in the latex phase. Study of an experimental 1 tonne per hour production; Radio-vulcanisation du caoutchouc naturel en phase latex. Etude d'une production experimentale de 1 tonne par heure

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, P; Puig, J R; Roudeix, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    After briefly reviewing the main research carried out on the radio-vulcanization of latex and elastomers, a description is given of 4 types of cell which have been used successively with a view to industrial irradiation. They have made it possible to acquire the information necessary for resolving the main problem arising during irradiation - the formation of coagulum. The first two cell are designed for irradiation by a horizontal beam ('Dynamitron'), the two others use a vertical beam ('Circe'). The study of the properties of the rubber obtained shows it to compare favorably with 'Revultex'. In the appendix are given some characteristics of natural latex and information about its processing. (authors) [French] Apres un rappel des principales etudes sur la radio-vulcanisation du latex et des elastomeres, on decrit les quatre types de cellules successivement essayes en vue de l'irradiation industrielle. Ils ont permis d'acquerir les informations necessaires a la resolution du probleme principal pose par l'irradiation, la formation de coagulum au cours de celle,-ci. Les deux premiers sont concus pour l'irradiation par un faisceau horizontal ('Dynamitron'), les derniers par un faisceau vertical ('Circe'). L'etude des proprietes du caoutchouc obtenu montre qu'il se compare favorablement au 'Revultex'. Un apercu est donne en annexe des caracteristiques du latex naturel et de sa mise en oeuvre. (auteurs)

  2. Scintillation Counters for Neutron Scattering Experiments; Compteurs a scintillations pour les experiences de diffusion neutronique; Stsintillyatsionnye schetchiki dlya ehksperimentov s rasseyaniem nejtronov; Contadores de centelleo para experimentos de dispersion neutronica.

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D; Duffil, C [Atomic Energy of Canada Ltd., Chalk River, Ontario (Canada); Wraight, L A [Aere, Harwell, Didcot, Berks (United Kingdom)

    1963-01-15

    Scintillation counters discussed in this paper are of two types : (i) UP or B{sub 2}O{sub 3} fixed with zinc sulphide in varving composition, (ii) Li containing glasses of varying composition. The ideal composition of each rype for neutron scattering experiments and their relative sensitivity tae neutrons and {gamma}-rays are considered. The ZnS type can be used with a {gamma}-ray pulse shape discriminator and practical experience of its use in a multi-counter time-of-flight experiment is described. The Li glass has higher {gamma}-background but also higher neutron efficiency. Performance figures of a scintillator containing 25% by wt. Li{sub 2}O and 1 mm thick will be given. (author) [French] Les compteurs a scintillations etudies sont de deux types : i) LiF ou B{sub 2}O{sub 3} fixe par du sulfure de zinc en composition variable, ii) verres contenant du lithium en composition variable. Les auteurs examinent la composition ideale de chaque type de compteur pour les experiences de diffusion de neutrons, ainsi que leur sinsibilite rrelative aux neutrons et aux rayons gamma. On peut utiliser le compteur a ZnS avec un discriminates de forme pour rayons gamma; les auteurs decrivent l'experience qu'ils ont de son emploi dans une experience de temps de vol a plusieurs compteurs. Le compteur verre-Li a un mouvement propre plus eleve pour les rayons gamma mais une meilleure efficacite vis-a-vis des neutrons. Les auteurs donnent quelques chiffres concernant le fonctionnement d'un scintillateur contenant 25% en poids de Li{sub 2}O et ayant une epaisseur de un millimetre. (author) [Spanish] Los contadores de centelleo examinados en esta memoria son de dos tipos : a) de LiF o B{sub 2}O{sub 3} mezclado con sulfuro de cinc en proporciones variables; b) de vidrios litiados de diversas composiciones. Los autores estudian la composicion ideal de cada tipo para experimentos de dispersion neutronica, asi como su sensibilidad relativa a los neutrones y a los rayos gamma. El tio de Zn

  3. Use of the helium-3 proportional counter for neutron spectrometry; Utilisation du compteur proportionnel a helium 3 pour la spectrometrie des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Vialettes, H; Le Thanh, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    compteur proportionnel a helijum 3 a e,te envisagee. Ce rapport presente les principes d'utilisation du spectrometre a helium 3, et les methodes de calcul qui permettent de tenir compte des deux effets principaux qui tendent a deformer le spectre obtenus: - l'absorption d'energie par les parois du compteur - la perte d'energie des neutrons incidents par chocs elastiques sur les noyaux d'helium 3. A titre d'application on a trace le spectre des neutrons emis par une source de polonium-lithium; les resultats obtenus sont en excellent accord avec les predictions theoriques. (auteurs)

  4. Behaviour of BF{sub 3} counters after in-pile irradiation; Comportement de compteurs a BF{sub 3} apres irradiation dans un reacteur

    Energy Technology Data Exchange (ETDEWEB)

    Verdant, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The behaviour of a proportional BF{sub 3}LCT 14 NE 31 counter with aluminium cathode has been studied after irradiation from 10{sup 5} to 10{sup 6} n.cm{sup -2} in the swimming-pool reactor Triton. The pulse spectrum was only slightly modified by two successive irradiations at 10{sup 15} n.cm{sup -2}, and 1 hour after the end of the irradiation the decrease in sensitivity reached 10 to 20 per cent. One hour after irradiation at 10{sup 16} n.cm{sup -2} this decrease was 20 per cent but the pulse spectrum was affected. The advantages of an aluminium cathode with respect to a standard counter using a copper cathode and irradiated under the same conditions are given. Beforehand, it had been established that the limit for use of an aluminium-cathode counter in the presence of {gamma} radiation is about 200 R.h{sup -1}. (author) [French] Le comportement d'un compteur proportionnel a BF-3LCT 14 NE 31, a cathode d'aluminium, a ete etudie apres des irradiations de 10{sup 5} a 10{sup 6} n.cm{sup -2} dans la pile-piscine TRITON. Deux irradiations successives de 10{sup 15} n.cm{sup -2} ont peu modifie le spectre des impulsions et 1 heure apres la fin de l'exposition la perte de sensibilite etait de 10 a 20 pour cent. Une heure apres une irradiation de 10{sup 16} n.cm{sup -2}, cette perte etait de 20 pour cent mais le spectre d'impulsions etait perturbe. L'avantage d'une cathode en aluminium est mis en evidence par comparaison avec un compteur standard a cathode de cuivre irradie dans les memes conditions. En preliminaire, on avait etabli que la limite d'utilisation d'un compteur a cathode d'aluminium en presence de rayonnements {gamma} etait de l'ordre de 200 R.h{sup -1}. (auteur)

  5. Preconcentration of uranium ores by radio-metric sorting; Preconcentration des minerais d'uranium par triage radiometrique

    Energy Technology Data Exchange (ETDEWEB)

    Avril, R; Grenier, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The uranium ore chemical treatment plant at Bessines-sur-Gartempe is supplied entirely by the La Crouzille Mining Division of the French Atomic Energy Commission mainly from mining districts of Fanay, Margnac and Le BRUGEAUD in the Limousin province and also, for the remainder, by a certain amount of private production in the 'Massif Central'. The supply mixture, which is very heterogeneous, is enriched before being treated chemically. The pre-concentration operation is carried out in the divisions ore treatment work-shop. It consists in a stone removal operation using radiometric sorting along a continuous belt; this makes it possible to eliminate 50 pour cent of the only fraction which is thus treated - that from 50 to 120 mm; it represents 15 to 20 per cent of the total tonnage supplied to the plant. (authors) [French] L'usine chimique de traitement des minerais d'uranium de Bessines-sur-Gartempe est entierement alimentee par la Division Miniere de La Crouzille, du Commissariat a l'Energie Atomique, principalement a partir des ensembles miniers limousins de Fanay, Margnac et du Brugenud et, pour le complement, par une certaine production privee en provenance du Massif Central. Le melange d'alimentation, tres heterogene, est enrichi avant d'etre livre a la chimie. L'operation de preconcentration est realisee dans l'atelier de preparation des minerais de la division. Il s'agit d'un epierrage par triage radiometrique sur bande, en continu, qui permet d'eliminer 50 pour cent de la seule fraction granulometrique qui le subit - le 50-120 mm - soit encore 15 a 20 pour cent du tonnage global d'alimentation livre a l'usine. (auteurs)

  6. A radio-crystallographic apparatus for the examination of irradiated materials; Appareil de radiocristallographie pour examens de materiaux irradies

    Energy Technology Data Exchange (ETDEWEB)

    Bloch, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Description of a radio-crystallographic apparatus designed for the examination of irradiated metals. - The double diffraction method was used: a monochromator is placed in the beam of X-rays diffracted by the sample, thus enabling lead shielding to be interposed between the sample and the counter. In this way a very large proportion of the radiation due to the activity of the sample is eliminated. By this method substances with activities of the order of several tens of curies may be examined, and the relative precision obtained in measurements of parameters with this apparatus is equal to 10{sup -4} in the case of good crystals. (author) [French] Description d'un appareil de radiocristallographie destine a l'examen de metaux irradies. - Nous avons utilise la methode de double diffraction: un monochromateur est place dans le faisceau de rayons X diffracte par l'echantillon, ce qui permet d'interposer une protection de plomb entre l'echantillon et le compteur. On elimine ainsi dans une tres grande proportion le rayonnement du a la radioactivite de l'echantillon. On peut ainsi examiner des substances d'une activite de l'ordre de quelques dizaines de curies et la precision relative obtenue pour les mesures de parametres avec cet appareil est egale a 10{sup -4} dans le cas de bons cristaux. (auteur)

  7. A Low-Level Geiger-Counter for Tritium; Compteur Geiger a faible mouvement propre pour le tritium; Schetchik Gejgera s nizkim urovnem dlya tritiya; Contador Geiger de baja actividad de fondo para tritio

    Energy Technology Data Exchange (ETDEWEB)

    Von Buttlar, H; Stahl, W [Technische Hochschule, Darmstadt (Germany)

    1962-01-15

    A cylindrical counter tube of volume 11 l was constructed which contains a number of anticoincidence wires surrounding a 2.9 l effective-volume centre-counter. The centre counter is separated from the anticoincidence section by a thin aluminized Hostaphan foil. Details of the construction are given. The counter filling gas consists of 30 mm ethylene, 40 mm argon and up to 700 mm sample hydrogen. An external quenching circuit with a 7 msec dead time effectively eliminates after-pulses. In a 30 cm iron shield, the counting rates of the centre counter with dead hydrogen gas are 350 counts/min without and about 3 counts/min with the anticoincidence circuit in operation. If it is assumed that 1 count/min above background is significant, a T/H ratio of as low as 10{sup -16} can be measured without isotope enrichment. Experiments are in progress to check the longtime stability of the arrangement. (author) [French] Les auteurs ont monte un tube compteur cylindrique d'un volume de 11 litres qui contient un certain nombre de conducteurs d'anticoincidence entourant un compteur central d'un volume reel de 2,9 litres. Ce compteur central est separe de la zone d'anticoincidence par une feuille mince d' ''Hostaphan'' recouverte d'aluminium. Les auteurs donnent des details sur le montage de l'appareil. Le melange gazeux remplissant le compteur se compose d'ethylene (30 mm), d'argon (40 mm) et de l'echantillon d'hydrogene (jusqu' a 700 mm). Un circuit coupeur externe ayant un temps mort de 7 ms elimine efficacement les impulsions retardees. Avec une protection de fer de 30 cm, les taux de comptage du compteur central, rempli d'hydrogene inerte, sont de 350 coups par minute et d'environ 3 coups par minute, selon que le circuit d'anticoincidence fonctionne ou non. Si l'on suppose qu'un coup par minute au-dessus du bruit de fond est significatif, on peut mesurer des rapports T/H jusqu' a 10{sup -16} sans avoir a proceder a un enrichissement. On effectue actuellement des experiences

  8. The n,{gamma} discrimination in recoil-proton proportional counters. Application to the measurement of fast neutron spectra; Discrimination n,{gamma} dans les compteurs proportionnels a protons de recul. Application a la mesure des spectres de neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Jeandidier, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    A description is given of a spectrometry chain working in the energy range of a few keV to 1 MeV, and designed for measurement of fast neutron spectra. It consists of detectors, recoil proton proportional counters built especially for this work by R. COMTE (DEG/SER) and which make it possible to cover the energy range and also associated electronic equipment. A brief description is first given of the physical processes involved: (n,p) collisions in the gas, influence of {gamma} radiation; the method of discrimination is then presented. It is based on the difference in the rise-times of the pulses. In the experiments described here the use of a bi-parametric system made it possible to employ the most simple discrimination device, based on the fact that the high frequency gamma pulse components are, at a given energy, weaker than those of the neutron pulses. Results are given of measurements carried out on the Van der Graaff (mono-energetic neutrons for testing the linearity of the chain and the resolving power of the counters), and of those made in a sub-critical system Hug at Cadarache. (author) [French] On decrit une chaine de spectrometrie travaillant dans le domaine d'energie de quelques keV a 1 MeV destinee a la mesure des spectres de neutrons rapides. Elle comprend les detecteurs, compteurs proportionnels a protons de recul, realises specialement pour cette etude par M. R. COMTE (DEG/SER), permettant de couvrir la gamme d'energie et l'electronique associee. Apres un rappel des processus physiques mis en jeu: chocs (n,p) dans les gaz, influence des rayonnements {gamma}, on expose la methode de discrimination utilisee. Celle-ci est basee sur la difference des temps de montee des impulsions. Au cours des experiences rapportees ici, la mise en oeuvre d'un ensemble bi-parametrique a permis d'utiliser le dispositif de discrimination le plus simple, base sur la remarque que les composantes a haute frequence des impulsions {gamma} sont, a energie egale, plus faibles

  9. The n,{gamma} discrimination in recoil-proton proportional counters. Application to the measurement of fast neutron spectra; Discrimination n,{gamma} dans les compteurs proportionnels a protons de recul. Application a la mesure des spectres de neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Jeandidier, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    A description is given of a spectrometry chain working in the energy range of a few keV to 1 MeV, and designed for measurement of fast neutron spectra. It consists of detectors, recoil proton proportional counters built especially for this work by R. COMTE (DEG/SER) and which make it possible to cover the energy range and also associated electronic equipment. A brief description is first given of the physical processes involved: (n,p) collisions in the gas, influence of {gamma} radiation; the method of discrimination is then presented. It is based on the difference in the rise-times of the pulses. In the experiments described here the use of a bi-parametric system made it possible to employ the most simple discrimination device, based on the fact that the high frequency gamma pulse components are, at a given energy, weaker than those of the neutron pulses. Results are given of measurements carried out on the Van der Graaff (mono-energetic neutrons for testing the linearity of the chain and the resolving power of the counters), and of those made in a sub-critical system Hug at Cadarache. (author) [French] On decrit une chaine de spectrometrie travaillant dans le domaine d'energie de quelques keV a 1 MeV destinee a la mesure des spectres de neutrons rapides. Elle comprend les detecteurs, compteurs proportionnels a protons de recul, realises specialement pour cette etude par M. R. COMTE (DEG/SER), permettant de couvrir la gamme d'energie et l'electronique associee. Apres un rappel des processus physiques mis en jeu: chocs (n,p) dans les gaz, influence des rayonnements {gamma}, on expose la methode de discrimination utilisee. Celle-ci est basee sur la difference des temps de montee des impulsions. Au cours des experiences rapportees ici, la mise en oeuvre d'un ensemble bi-parametrique a permis d'utiliser le dispositif de discrimination le plus simple, base sur la remarque que les composantes a haute frequence des impulsions {gamma} sont, a

  10. Analytical studies by activation. Part A and B: Counting of short half-life radio-nuclides. Part C: Analytical programs for decay curves; Etudes d'analyse par activation. Parties A et B: le comptage des radio-nucleides de periodes courtes. Partie C: programme de depouillement des courbes de decroissance

    Energy Technology Data Exchange (ETDEWEB)

    Junod, E [Commissariat a l' Energie Atomique Grenoble (France). Centre d' Etudes Nucleaires

    1966-03-01

    Part A and B: Since a radio-nuclide of short half-life is characterized essentially by the decrease in its activity even while it is being measured, the report begins by recalling the basic relationships linking the half-life the counting time, the counting rate and the number of particles recorded. The second part is devoted to the problem of corrections for counting losses due to the idle period of multichannel analyzers. Exact correction formulae have been drawn up for the case where the short half-life radionuclide is pure or contains only a long half-life radio-nuclide. By comparison, charts have been drawn up showing the approximations given by the so-called 'active time' counting and by the counting involving the real time associated with a measurement of the overall idle period, this latter method proving to be more valid than the former. A method is given for reducing the case of a complex mixture to that of a two-component mixture. Part C: The problems connected with the qualitative and quantitative analysis of the decay curves of a mixture of radioactive sources of which one at least has a short half-life are presented. A mathematical description is given of six basic processes for which some elements of Fortran programs are proposed. Two supplementary programs are drawn up for giving an overall treatment of problems of dosage in activation analysis: one on the basis of a simultaneous irradiation of the sample and of one or several known samples, the other with separate irradiation of the unknown and known samples, a dosimeter (activation, or external) being used for normalizing the irradiation flux conditions. (author) [French] Parties A et B: Un radionucleide de periode courte etant defini specialement par la decroissance de son activite pendant la duree meme du comptage, on rappelle en premiere partie de ce rapport les relations fondamentales qui lient periode, temps de comptage, taux de comptage et nombre d'impulsions enregistrees. La seconde partie

  11. Application of a proportional counter to some particular cases of {alpha} measurements; Applications d'un compteur proportionnel a quelques cas particuliers de mesures {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Ferret, J; Gasc, M T; Le Du, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    I - A measurement method based on {alpha} {gamma} coincidences is used for activity measurements on {sup 241}Am in the presence of a strong {alpha} activity due to Pu. The sensitivity of the apparatus makes it possible to detect: less than 10{sup -7} {mu}C {sup 241}Am in the presence of a Pu activities several hundred times greater. II - The same equipment has been used for {alpha} measurements on {alpha}-emitting sources in the presence of very strong {beta} and {gamma} activities. In particular results are given for {alpha}-activity measurements on powder samples. It is even possible in these conditions, to detect or measure {sup 241}Am. III - The equipment makes possible also: - the absolute calibration of a pure {sup 241}Am source - {sup 237}Np measurements - simultaneous measurements of {alpha}, {beta} and {gamma} activities in solid samples in various forms. IV - The assembly includes a small-size proportional counter operating in conjunction with a {gamma} probe, together with auxiliary electronic equipment (stabilized high voltages, amplifiers, a coincidence unit, a sealer). (authors) [French] I - Une methode de mesures par coincidences {alpha} {gamma} est utilisee pour des mesures d'activite de {sup 241}Am en presence d'activite {alpha} (due au Pu) importante. -La sensibilite de l'appareillage permet de deceler: moins de 10{sup -7} {mu}C {sup 241}Am dans les activites {alpha} Pu plusieurs centaines de fois plus importantes. II - Le meme appareillage a ete utilise pour des mesures {alpha} sur des sources emettrices {alpha} en presence d'activites {beta} et {gamma} tres importantes. En particulier des mesures d'activite {alpha} sur des echantillons de poudre sont exposees. Il est meme possible, dans ces conditions, de deceler ou mesurer {sup 241}Am. III - L'ensemble permet egalement: - l'etalonnage absolu d'une source de {sup 241}Am pur - des mesures de {sup 237}Np - des mesures simultanees d'activites {alpha}, {beta} et {gamma} dans des echantillons solides

  12. Cycle annuel d'activité de la truite commune (Salmo trutta L. adulte : Étude par radio-pistage dans un cours d'eau de l'Ardenne belge

    Directory of Open Access Journals (Sweden)

    OVIDIO M.

    1999-01-01

    Full Text Available Sur une durée totale d'expérience de vingt-six mois, vingt truites (26,0-57,0 cm LF ; 198-1 685 g ont été quotidiennement suivies par radio-pistage dans l'Aisne (affluent de l'Ourthe durant des périodes variant de 466 à 16 jours selon les individus et les contraintes techniques expérimentales, notamment la durée de vie des batteries. Il apparaît que l'amplitude et la fréquence des mouvements sont le plus élevées d'octobre à décembre, pendant la période de reproduction. Les migrations vers l'amont (max. : 25 km ont principalement lieu en octobre et pendant la première quinzaine de novembre et sont déclenchées par des variations combinées du niveau d'eau et de la température, dans une gamme thermique précise (10°C à 14°C. Le frai (de la deuxième quinzaine de novembre à la fin décembre a lieu dans le cours principal (largeur maximale : 10 m ou dans de petits affluents. Les truites qui survivent effectuent un homing post-reproducteur rapide (max. : 9 200 m en 24 h et précis. En dehors du contexte de la reproduction, les déplacements sont moins longs et correspondent essentiellement à des changements alternés de gîtes dans un domaine vital bien défini dont la longueur est corrélée avec la taille des truites. En mars et juin, certaines truites effectuent des migrations unidirectionnelles de grande amplitude vers l'amont dont la signification biologique est inconnue. Les résultats sont discutés dans le contexte des stratégies de vie de la truite et de la gestion des populations.

  13. Particularites radio-cliniques et bacteriologique de la tuberculose ...

    African Journals Online (AJOL)

    Particularites radio-cliniques et bacteriologique de la tuberculose pulmonaire chez les patients infectees par le vih au centre hospitalier Sylvanus Olympio de Lome. Radio-clinical and bacteriologial peculiarities of the pulmonary tuberculosis in hiv infe.

  14. X-spectrographic method for plutonium detection. Application to contamination measurements in humans; Etude d'une methode de detection du plutonium par spectrographie X. Application a la mesure des contaminations sur l'homme

    Energy Technology Data Exchange (ETDEWEB)

    Trouble, Michel [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    After reviewing the radio-toxicology of plutonium 239 and conventional detection methods using its {alpha}-radiation, the author considers the measurement of the X emission spectrum of plutonium 239 using a proportional counter filled with argon under pressure. This preliminary work leads to the third part of this research involving the detailed study of the possibilities of applying thin alkali halide crystal scintillators to the detection of soft plutonium X-rays; there follows a systematic study of all the parameters liable to render the detection as sensitive as possible: movement due to the photomultiplier itself and its accessory electronic equipment, nature and size of the crystal scintillator as well as its mode of preparation, shielding against external parasitic radiation. Examples of some applications to the measurement of contamination in humans give an idea of the sensitivity of this method. (author) [French] Apres un apercu de la radiotoxicologie du plutonium 239 et des methodes classiques de detection par son rayonnement {alpha}, on etudie le spectre d'emission X du plutonium 239 avec un compteur proportionnel rempli avec de l'argon sous pression. Ce travail preliminaire permet d'aborder la troisieme partie de cette etude dans laquelle nous examinons d'une fagon approfondie les possibilites d'application des cristaux scintillateurs minces d'halogenure alcalin a la detection du rayonnement X mou du plutonium; suit une etude systematique de tous les parametres susceptibles de rendre la detection aussi sensible que possible: mouvement propre du photomultiplicateur et de l'electronique associee, nature et dimensions du cristal scintillateur ainsi que son mode de fabrication, blindage contre les rayonnements parasites exterieurs. Quelques applications a la mesure des contaminations sur l'homme permettent d'apprecier la sensibilite de cette methode. (auteur)

  15. Comprehensive measurements in 4 {pi} geometry for radio-active samples having a low {beta}-activity (1962); Ensemble de mesure'en geometrie 4 {pi} pour echantillons radioactifs de faible activite {beta} (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Colomer, J; Valentin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The realisation is described of a comprehensive measurement system having low background noise and, as well as a lead-wall protection, an electronic protection made up of a plastic scintillator placed in anticoincidence with the 4 {pi} counter used for making the measurements. The apparatus is described and its performance discussed. (authors) [French] Realisation d'un ensemble de mesures ayant un faible bruit de fond en utilisant en plus d'une protection par murs de Pb, une protection electronique constituee par un scintillateur plastique mis en ainticoincidence avec le compteur 4 {pi} utilise pour faire les mesures. L'appareillage est decrit et ses performances discutees. (auteurs)

  16. Radio astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Nagnibeda, V.G.

    1981-01-01

    The history of radio astronomical observations at the Astronomical Observatory of Leningrad State University is reviewed. Various facilities are described, and methods and instruments used are discussed. Some results are summarized for radio observations of the sun, including observations of local sources of solar radio emission, the absolute solar radio flux, and radio emission from filaments and prominences.

  17. A practical contribution to the dosimetry of fast neutrons in radio-protection - determination of the integrated dose in man using the {sup 32}S(n, p){sup 32}P reaction (1963); Contribution pratique a la dosimetrie des neutrons rapides en radioprotection - determination de la dose integree par reaction {sup 32}S(n, p){sup 32}P chez l'homme (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Scheidhauer, J; Chabidon, M [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1963-07-01

    The problem of fast neutron dosimetry using activation is studied from the radio-protection point of view. The practical development of methods for analyzing phosphorus 32 produced by the activation of sulphur 32 in human hair by the reaction {sup 32}S(n, p){sup 32}P is described. The sensitivity obtained is 5 rad. A preliminary study was made of the variations in the natural sulphur and phosphorus concentrations. (authors) [French] Le probleme de la dosimetrie des neutrons rapides par activation est etudie sous l'angle de la radioprotectlon. Une mise au point pratique de methodes d'analyae du phosphore 32 induit par activation du soufre 32 des cheveux humains par reaction {sup 32}S(n, p){sup 32}P est exposee. La sensibilite obtenue est de 5 rad. Les variations du soufre et du phosphore naturels ont fait l'objet d'une etude preliminaire. (auteurs)

  18. Development of Geiger-Mueller counters for operation at high temperatures; Mise au point de compteurs Geiger-Mueller fonctionnant a haute temperature; Razrabotka schetchikov Gejgera-Myullera, rabotayushchikh pri povyshennoj temperature; Contadores Geiger-Mueller que funcionan a temperaturas elevadas

    Energy Technology Data Exchange (ETDEWEB)

    Draghicescu, M [Institut de Physique Atomique, Bucarest (Romania)

    1962-04-15

    Counters of this type are necessary for radioactive logging at great depths; they have to operate normally at temperatures up to 180{sup o}C. In order to preserve their characteristics under such conditions, the work function of the cathode has been improved by a special treatment. Tests have been made on counters with graphite, copper and wolfram cathodes in a glass envelope. The method is simple, and can easily be employed in industry. (author) [French] De tels compteurs sont necessaires pour le sondage radioactif aux grandes profondeurs; ils doivent fonctionner dans des conditions normales jusqu'a la temperature de 180{sup o}C. Afin qu'ils puissent conserver leurs caracteristiques jusqu'a cette temperature, on a agi sur le travail de sortie de la cathode par un traitement adequat. On a fait l'essai sur des compteurs avec cathode de graphite, de cuivre ou de tungstene, dans un ballon de verre. La methode proposee est simple et peut etre appliquee facilement dans l'industrie. (author) [Spanish] Se requiere este tipo de contador para la determinacion de la radiactividad a grandes profundidades; debe ser capaz de funcionar normalmente a temperaturas hasta de 180{sup o}C. A fin de que sus caracteristicas se conserven inalteradas hasta tales temperaturas, se ha modificado la funcion de trabajo del catodo mediante un tratamiento adecuando. Se han ensayado contadores con catodo de grafito, de cobre o de wolframio en un balon de vidrio. El metodo propuesto es simple y puede aplicarse facilmente en la industria. (author) [Russian] Podobnye schetchiki neobkhodimy dlya radioaktivnogo karottazha na bol'shikh glubinakh; oni dolzhny funktsionirovat' v normal'nykh usloviyakh pri temperature do 180{sup o}C. Nakonets, dlya togo, chtoby oni mogli sokhranyat' svoi osobennosti pri ehtoj temperature, bylo obrashcheno vnimanie na rabotu katodnogo vykhoda pri pomoshchi sootvetstvuyushchej obrabotki. Byl proveden opyt na schetchikakh s grafitovym, mednym ili vol'framovym katodom v

  19. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.

    1976-01-01

    Any discussion of the radio emission from stars should begin by emphasizing certain unique problems. First of all, one must clarify a semantic confusion introduced into radio astronomy in the late 1950's when most new radio sources were described as radio stars. All of these early 'radio stars' were eventually identified with other galactic and extra-galactic objects. The study of true radio stars, where the radio emission is produced in the atmosphere of a star, began only in the 1960's. Most of the work on the subject has, in fact, been carried out in only the last few years. Because the real information about radio stars is quite new, it is not surprising that major aspects of the subject are not at all understood. For this reason this paper is organized mainly around three questions: what is the available observational information; what physical processes seem to be involved; and what working hypotheses look potentially fruitful. (Auth.)

  20. Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M C; Charrier, G; Alba, C; Massimino, D [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l'etude du phenomene chromatographique dans les conditions

  1. Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M.C.; Charrier, G.; Alba, C.; Massimino, D. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l

  2. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.; Gibson, D.M.

    1985-01-01

    Studies of stellar radio emission became an important field of research in the 1970's and have now expanded to become a major area of radio astronomy with the advent of new instruments such as the Very Large Array in New Mexico and transcontinental telescope arrays. This volume contains papers from the workshop on stellar continuum radio astronomy held in Boulder, Colorado, and is the first book on the rapidly expanding field of radio emission from stars and stellar systems. Subjects covered include the observational and theoretical aspects of stellar winds from both hot and cool stars, radio flares from active double star systems and red dwarf stars, bipolar flows from star-forming regions, and the radio emission from X-ray binaries. (orig.)

  3. Realisation and tests of a compressed gas Cherenkov counter. Study of the pollution of a beam (1961); Realisation et essais d'un compteur cherenkov a gaz comprime etude de la pollution d'un faisceau (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Duboc, J; Banaigs, J; Detoeuf, J F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The realisation of a compressed as Cherenkov counter permits the study of the pollution of a beam of {pi} mesons with momentum varying from 220 to 11000 MeV/c. (authors) [French] La realisation d'un compteur Cherenkov a gaz sous pression permet l'etude de la pollution d'un faisceau de mesons {pi} d'impulsions comprise entre 220 et 1100 MeV/c. (auteurs)

  4. In vitro and in vivo study of endothelial cells radio-induced death modulation by Sphingosine-1-Phosphate; Etude in vitro et in vivo de la regulation de la mort radioinduite des cellules endotheliales par la Sphingosine-1-Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Bonnaud, St

    2007-01-15

    Protecting the vasculature from radiation-induced death is a major concern in tissue radioprotection. Developing a model of endothelial cells radiosensitivity, we proved that HMEC-1 undergo 2 waves of death after exposure to 15 Gy: an early pre mitotic apoptosis dependent of ceramide generation and a delayed DNA damage-induced mitotic death. Sphingosine-1-Phosphate (S1P), a ceramide antagonist, protects HMEC-1 only from early apoptosis, but not from mitotic death. We confirmed in vivo the S1P radioprotection from ceramide-mediated radio-induced apoptosis, and that S1P radioprotection is partially mediated by S1Ps receptors. Segregation between these 2 types of death may give the opportunity to define a new class of radioprotectors for normal tissue where quiescent endothelium represent the most sensitive target, while excluding malignant tumor containing pro-proliferating angiogenic endothelial cells, sensitive to mitotic death. (author)

  5. Radio-protection problems presented by iodine isotopes in nuclear fuel chemical treatment plants (1962); Les problemes de radioprotection poses par les isotopes de l'iode dans les installations de traitement chimique des combustibles (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Bouzigues, H; Scheidhauer, J; Messainguiral, L [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1962-07-01

    The origin of radio-iodine and the conditions in which it is liberated are given. The authors review the question of the risks associated with the presence of this radioelement In the atmosphere. Finally a method is proposed for the trapping and rapid measuring of the iodine in the vapour form, applicable to radioprotection. (authors) [French] L'origine et les conditions de liberation du radioiode sont exposees. Les auteurs font le point de la question des risques associes a la presence de ce radioelement dans l'atmosphere. Enfin, une methode de piegeage et de mesure rapide de l'iode a l'etat de vapeur applicable a la radioprotection, est proposee. (auteurs)

  6. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water; Etude experimentale de la contamination radioactive par l'eau d'irrigation de certaines plantes cultivees

    Energy Technology Data Exchange (ETDEWEB)

    Michon, G. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Barbier, G.; Le Blaye, P.; Brossard, M. [Station Centrale d' Agronomie, 78 - Versailles (France); Fioramonti, S.; Marty, J.R. [Station Agronomique de Toulouse, 31 (France); Benard, P.; Flanzy, M. [Station Centrale de Technologie des Produits Vegetaux, 11 - Narbonne (France); Delas, J.; Delmas, J.; Demias, Ch. [Station d' Agronomie de Bordeaux (Pont de la Maye), 33 (France); Huguet, C. [Station Agronomique d' Avignon, 84 (France)

    1964-07-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [French] Ce rapport fait suite aux rapports CEA no 1860 et 2159 et rapporte les resultats obtenus pendant les annees 1961 et 1962. Ces resultats confirment dans l'ensemble ceux precedemment obtenus tout en augmentant la variete des legumes etudies. La vigne et les prairies artificielles ont egalement fait l'objet d'etudes. La grande dispersion des valeurs limites du coefficient r (rapport entre la quantite de radioelements dans un kg de produits recoltes a la quantite de radioelements presente dans un litre d'eau d'irrigation) en rapport avec la nature des sols, le type vegetal, etc.., ne permet pas de degager de conclusions generales. Chaque cas de rejet necessite une etude particuliere dont le schema est donne. En tout etat de cause l'on doit s'attendre a ce que dans la plupart des cas ces etudes conduisent a une diminution des normes actuellement utilisees. (auteurs)

  7. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water; Etude experimentale de la contamination radioactive par l'eau d'irrigation de certaines plantes cultivees

    Energy Technology Data Exchange (ETDEWEB)

    Michon, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Barbier, G; Le Blaye, P; Brossard, M [Station Centrale d' Agronomie, 78 - Versailles (France); Fioramonti, S; Marty, J R [Station Agronomique de Toulouse, 31 (France); Benard, P; Flanzy, M [Station Centrale de Technologie des Produits Vegetaux, 11 - Narbonne (France); Delas, J; Delmas, J; Demias, Ch [Station d' Agronomie de Bordeaux (Pont de la Maye), 33 (France); Huguet, C [Station Agronomique d' Avignon, 84 (France)

    1964-07-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [French] Ce rapport fait suite aux rapports CEA no 1860 et 2159 et rapporte les resultats obtenus pendant les annees 1961 et 1962. Ces resultats confirment dans l'ensemble ceux precedemment obtenus tout en augmentant la variete des legumes etudies. La vigne et les prairies artificielles ont egalement fait l'objet d'etudes. La grande dispersion des valeurs limites du coefficient r (rapport entre la quantite de radioelements dans un kg de produits recoltes a la quantite de radioelements presente dans un litre d'eau d'irrigation) en rapport avec la nature des sols, le type vegetal, etc.., ne permet pas de degager de conclusions generales. Chaque cas de rejet necessite une etude particuliere dont le schema est donne. En tout etat de cause l'on doit s'attendre a ce que dans la plupart des cas ces etudes conduisent a une diminution des normes actuellement utilisees. (auteurs)

  8. suPAR

    DEFF Research Database (Denmark)

    Hodges, Gethin W; Bang, Casper N; Wachtell, Kristian

    2015-01-01

    The fundamental role of inflammation in cardiovascular disease (CVD) has prompted interest in numerous biomarkers that detect subclinical levels of inflammation. Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker that correlates significantly with cardiovascular events ...... comprehensive review of suPAR in CVD and explore its function and usefulness in predicting cardiovascular events....

  9. Automatic counting and recording unit used for dating by the carbon 14 method; Ensemble de comptage et d'impression automatique utilise pour la datation par la methode du carbone 14

    Energy Technology Data Exchange (ETDEWEB)

    Albertinoli, P; Galliot, J; Thommeret, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Centre Scientifique de Monaco, Monte Carlo

    1969-07-01

    A description is given of the unit used by the 'Centre Scientifique de Monaco' for low-level beta counting and fitted for radioactive dating by the Carbon 14 method. Built entirely by the laboratory in 1964, on the basis of electronic techniques then recent, it has worked without failure since that time. The proportional counter, its high-voltage negative supply, and the counting chains with visual and printing records are detailed by means of 38 figures which reproduce the counter and the electronic circuits. These are contained in two standard 5 U.I structures. The low-voltage power supply of the whole unit is carried out by plus 12 volts and minus 12 volts storage batteries, buffered on a charger connected on the 110 V alternative line. The proportional counter described is filled with CO{sub 2} under one atmosphere pressure and permits the dating of carbonaceous samples with a maximum of 30.000 + 1.000 years (background 3.96 c.p.m. ) within a moderate time (72 hours). (authors) [French] L'ensemble de comptage pour radioactivite beta a bas niveau, destine a la datation par la methode du carbone 14, utilise au Centre Scientifique de Monaco, est decrit. Entierement construit au laboratoire en 1964, sur la base de techniques electroniques alors recentes, il fonctionne depuis cette date sans defaillance. Le compteur proportionnel, son alimentation haute tension negative et les chaines de comptage transistorisees a affichage et impression sont detailles par 38 schemas reproduisant le compteur et les divers circuits electroniques. Ceux-ci sont contenus dans deux chassis standard 5 UI. L'alimentation basse tension de l'ensemble est obtenue par batteries plus 12 et moins 12 volts montees en tampon sur chargeur alimente par le reseau. Le compteur proportionnel decrit, rempli de CO2 sous une atmosphere, permet de dater les echantillons carbones avec un maximum de 30.000 + 1.000 ans (bruit de fond: 3,96 c.p.m. ) en un temps raisonnable (72 heures). (auteur)

  10. Par Pond water balance

    International Nuclear Information System (INIS)

    Hiergesell, R.A.; Dixon, K.L.

    1996-06-01

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs

  11. FooPar

    DEFF Research Database (Denmark)

    Hargreaves, F. P.; Merkle, D.

    2013-01-01

    We present FooPar, an extension for highly efficient Parallel Computing in the multi-paradigm programming language Scala. Scala offers concise and clean syntax and integrates functional programming features. Our framework FooPar combines these features with parallel computing techniques. Foo......, results based on a empirical analysis on two supercomputers are given. We achieve close-to-optimal performance wrt. theoretical peak performance. Based on this result we conclude that FooPar allows programmers to fully access Scalas design features without suffering from performance drops when compared...

  12. Heavy element concentration determination by the x-ray fluorescence analysis using radioisotope {gamma}-ray sources; Dosage d'elements lourds par fluorescence X utilisant des radio-sources de rayons gamma

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, S [Commissariat a l' Energie Atomique, Dir. des Materiaux et des Combustibles Nucleaires, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    A theoretical and experimental study has been made on the fluorescence analysis of high atomic number element, using {gamma}-ray sources for excitation and characteristic K X-rays for the measurement. The choice of the proper {gamma}-ray energy according to the conditions of the determination is considered. The author has studied the usefulness of using the backscattered {gamma}-rays as a correction mean for matrix and grain-size effects. Sources of {sup 153}Gd, {sup 57}Co, {sup 137}Cs have been used for excitation using collimated geometries. Concentration measurements of tungsten in steel, tungsten and lead in aqueous solution, PbS in SiO{sub 2}-PbS powder mixtures have been done, as well as thickness evaluation of gold layers on copper. A precision of about 0.2 per cent (abs.) is obtained for lead determination in light matrixes. A probe design is proposed for the continuous determination of lead in aqueous solutions. (author) [French] On etudie de maniere theorique et experimentale l'analyse d'elements a nombre atomique eleve par fluorescence en utilisant des sources de rayons {gamma} pour l'excitation, et des rayons-X K caracteristiques pour la mesure. On considere le choix de l'energie appropriee des rayons {gamma} suivant les conditions experimentales. L'utilite d'employer les rayons {gamma} retrodiffuses pour corriger les effets de la matrice et de la dimension des grains est etudiee. Des sources de {sup 153}Gd, de {sup 57}Co et de {sup 137}Cs a geometrie collimatee ont ete utilisees pour l'excitation. Des mesures de la concentration du tungstene dans l'acier, du tungstene et du plomb en solutions aqueuses, et du PbS dans des melanges de poudre SiO{sub 2}-PbS ont ete entreprises ainsi que l'evaluation de l'epaisseur des couches d'or sur le cuivre. On obtient une precision d'environ 0,2 pour cent (en absolu) pour la determination du plomb dans des matrices legeres. On propose un modele de sonde pour la determination en continu du plomb en solution aqueuse

  13. Solar Radio

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists monitor the structure of the solar corona, the outer most regions of the Sun's atmosphere, using radio waves (100?s of MHz to 10?s of GHz). Variations in...

  14. Radio astronomy

    International Nuclear Information System (INIS)

    Parijskij, Y.N.; Gossachinskij, I.V.; Zuckerman, B.; Khersonsky, V.K.; Pustilnik, S.; Robinson, B.J.

    1976-01-01

    A critical review of major developments and discoveries in the field of radioastronomy during the period 1973-1975 is presented. The report is presented under the following headings:(1) Continuum radiation from the Galaxy; (2) Neutral hydrogen, 21 cm (galactic and extragalactic) and recombination lines; (3) Radioastronomy investigations of interstellar molecules; (4) Extragalactic radio astronomy and (6) Development in radio astronomy instruments. (B.R.H.)

  15. Detection by radio-auto-histography of the β-indolylacetic acid and its metabolic derivatives. Test of application to the search for their histological and cytological location; Detection, par radioautohistographie, de l'acide β-indolylacetique et de ses derives metaboliques. Essai d'application a la recherche de leur localisation histologique et cytologique

    Energy Technology Data Exchange (ETDEWEB)

    Figier, Jacques

    1961-02-04

    After having given an overview of research works in biophysics and biochemistry related to the study of the auxinic action within a cell, this research thesis reports the use of radio-auto-histography to detect the βindolylacetic acid within tissues and within a cell. The author reports experiments performed by using this acid either in its normal status, or marked either with carbon 14 or with tritium. Growth tests have been performed by using different plants. The author also presents insolubilization techniques which have been applied to the acid for this study. In vivo tests have been performed with the radioactive acid and other precipitation compounds (lead acetate, mercury nitrate). The acid detection technique is presented, and results are discussed [French] Dans le but de detecter, par radioautohistographie, l'acide β-indolylacetique marque au tritium et ses derives metaboliques, nous avons mis au point des techniques nouvelles d'insolubilisation de l'A.I.A. L'acide picrique et l'acetate de plomb donnant avec l'auxine un precipite insoluble dans les liquides de fixation (Formol neutre-Liquide de Bouin) et d'inclusion, nous avons reussi a conserver dans des epicotyles de pois et de haricot, des racines de feve et de pois, des coleoptiles d'avoine, une importante fraction de l'A.I.A. marque fourni a ces tissus (a des concentrations superieures ou egales a 10 mg/l). Cette detection etant satisfaisante, nous avons essaye de localiser l'A.I.A. et ses derives, avec plus de precision, dans la cellule en particulier. Mais il fallait alors tenir compte de plusieurs causes d'erreur possible: l'effet nocif eventuel du liquide precipitant (acide picrique ou acetate de plomb), - la diffusion d'A.I.A. dans ce liquide, - la cytologie imparfaite et en particulier l'incertitude sur la limite vacuole-cytoplasme. Compte tenu de ces critiques, il nous semble que la radioactivite (due a la presence d'A.I.A. et des produits derives) se localise plus particulierement au

  16. Radio astronomy

    CERN Document Server

    Alder, Berni

    1975-01-01

    Methods in Computational Physics, Volume 14: Radio Astronomy is devoted to the role of the digital computer both as a control device and as a calculator in addressing problems related to galactic radio noise. This volume contains four chapters and begins with a technical description of the hardware and the special data-handling problems of using radioheliography, with an emphasis on a selection of observational results obtained with the Culgoora radioheliograph and their significance to solar physics and to astrophysics in general. The subsequent chapter examines interstellar dispersion, i

  17. It's quicker "Par Avignon"!

    CERN Multimedia

    2005-01-01

    For a few years, the CERN Library has been receiving books from the University of Hanover sent via Avignon, at least that's what it says on the envelope. Such a detour would mean that parcels were travelling 720 km more than the distance separating Geneva and Hanover, which would be a very strange state of affairs. The explanation lies in a spelling mistake. The sender has been stamping parcels with a stamp that says "Par Avignon prioritaire" (first-class via Avignon) instead of "Par Avion prioritaire" (First Class Air Mail), a source of much amusement to the librarians!

  18. La pelade par plaques

    Science.gov (United States)

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.

  19. The Radio JOVE Project - Shoestring Radio Astronomy

    Science.gov (United States)

    Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.

    2010-01-01

    Radio JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning radio astronomy. They can do this through building a radio telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (Radio Skypipe) and other reference materials

  20. The 2010 Polar Aeronomy and Radio Science (PARS) Summer School

    Science.gov (United States)

    2011-12-30

    Ionospheric Plasma ........................................................................26 3.7. Measurements of HF Wave-Induced Micropulsations Using GMOS ...facility‟s most distant diagnostic pad. This instrument, called the Geomagnetic Observatory System ( GMOS ) is capable of measuring very small...angles 3.7. Measurements of HF Wave-Induced Micropulsations Using GMOS 3.7.1. Investigators J. Gancarz, R. Pradipta, and Min-Chang Lee (Mentor

  1. Space Telecommunications Radio System STRS Cognitive Radio

    Science.gov (United States)

    Briones, Janette C.; Handler, Louis M.

    2013-01-01

    Radios today are evolving from awareness toward cognition. A software defined radio (SDR) provides the most capability for integrating autonomic decision making ability and allows the incremental evolution toward a cognitive radio. This cognitive radio technology will impact NASA space communications in areas such as spectrum utilization, interoperability, network operations, and radio resource management over a wide range of operating conditions. NASAs cognitive radio will build upon the infrastructure being developed by Space Telecommunication Radio System (STRS) SDR technology. This paper explores the feasibility of inserting cognitive capabilities in the NASA STRS architecture and the interfaces between the cognitive engine and the STRS radio. The STRS architecture defines methods that can inform the cognitive engine about the radio environment so that the cognitive engine can learn autonomously from experience, and take appropriate actions to adapt the radio operating characteristics and optimize performance.

  2. Adjustment of a direct method for the determination of man body burden in Pu-239 on by X-ray detection of U-235; Mise au point d'une methode directe de determination de la charge corporelle en plutonium 239 chez l'homme par detection X de l'uranium 235

    Energy Technology Data Exchange (ETDEWEB)

    Boulay, P [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1968-04-01

    The use of Pu-239 on a larger scale sets a problem about the contamination measurement by aerosol at lung level. A method of direct measurement of Pu-239 lung burden is possible, thanks to the use of a large area window proportional counter. A counter of such pattern, has been especially carried out for this purpose. The adjustment of the apparatus allows an adequate sensibility to detect a contamination at the maximum permissible body burden level. Besides, a method for individual 'internal calibration', with a plutonium mock: the protactinium-233, is reported. (author) [French] L'utilisation a une echelle de plus en plus large du plutonium-239 pose un probleme de la mesure de la contamination par aerosol au niveau du poumon. Une methode de mesure directe de la charge pulmonaire en plutonium-239 est possible grace a l'utilisation d'un compteur proportionnel a fenetre de grande surface. Un compteur de ce type a specialement ete realise dans ce but. La mise au point de l'appareillage permet une sensibilite suffisante pour deceler une contamination au niveau de la Q.M.A (quantite maximale admissible). D'autre part, une methode 'd'etalonnage interne' de l'individu a l'aide d'un simulateur de plutonium, le protactinium-233, est decrite. (auteur)

  3. The Proportional Counter. Some Aspects of Operation; Le compteur proportionnel. Ses caracteristiques de fonctionnement; Proportsional'nyj schetchik. Nekotorye aspekty raboty; El contador proportional. Sus caracteristicas de funcionamiento

    Energy Technology Data Exchange (ETDEWEB)

    Curran, S C [Awre, Aldermaston (United Kingdom)

    1960-06-15

    matters such as long-term gas purity are difficult to overcome. 3. Studies of Electron Attachment - An approach to systematic observations in gases and mixtures of moment in proportional counting is described. It is hoped that such measurements as are effected with this arrangement will be valuable in enlarging the field of application of the counters. (author) [French] 1. Les travaux consacres a la mise au point d'un dispositif de comptage destine a l'etude de la capture electronique ont montre que le diametre du, fil constituant l'anode dans un compteur proportionnel a haute pression peut avoir une influence importante sur le pouvoir de resolution en energie obtenu dans les mesures de rayonnements de faible energie. Dans un compteur travaillant sous une pression de 12 atmospheres, l'amplitude de la repartition des impulsions dues aux rayonnements de capture K de 13,5 keV a pu etre ramenee de 65% a 17%. en reduisant de 0,0076 mm a 0,0025 mm le diametre du fil. Ce phenomene est interprete comme constituant un effet de la charge spatiale en ions positifs dans l'avalanche. Pour un gain et un rayonnement primaire donnes, la densite des ions positifs dans l'avalanche s'accroit rapidement avec la pression du gaz de remplissage, et lorsque les champs electriques d'accompagnement sont assez grands pour affecter les derniers stades du processus de multiplication, le pouvoir de resolution en energie du compteur diminue. Toute diminution du diametre de l'anode entraine un accroissement du champ applique exterieurement, dans la region ou se produit la multiplication, ce qui tend a contrecarrer l'effet de la charge spatiale. L'emploi de fils d'un diametre de 0,0025 mm a donne des resultats satisfaisants lors de nouvelles mesures des rapports de capture L/K effectuees au moyen d'un dispositif de comptage a fils multiples, travaillant sous des pressions pouvant atteindre 12 atmospheres. Les resultats obtenus pour les rapports de capture L/K du Ge{sup 71} et du Kr{sup 79} sont de 0

  4. suPAR

    DEFF Research Database (Denmark)

    Eugen-Olsen, Jesper; Giamarellos-Bourboulis, Evangelos J

    2015-01-01

    Investigation of biomarkers that can promptly predict unfavourable outcome of critically illness is an emerging necessity taking into consideration the need for early intervention, the shortage of available beds in intensive care units and the considerable cost of hospitalisation. The most...... promising biomarker is soluble urokinase-type plasminogen activator receptor (suPAR). Three studies in large populations of critically ill patients and patients admitted to the emergency department have shown that concentrations >12ng/mL can safely predict unfavourable outcome. This review presents...

  5. Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, W R; Watson, G M; DeVan, J H; Evans, R B [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1962-03-15

    When Inconel or Inor-8 alloys are exposed to a molten fluoride mixture containing reducible material, chromium is selectively oxidized and removed from the alloy. By the use of radio-tracer Cr{sup 51}, the self-diffusion coefficients for chromium in Inconel and Inor-8 and the applicability of these values to alloys under corrosive conditions have been evaluated. Overall coefficients have been obtained (1) by measuring depletion of Cr{sup 51} (charged as CrF{sub 2}) for non-corrosive fluoride melts in alloy capsules and (2) by comparison of measured total radioactivity of exposed alloy specimens with that of the salt to which they were exposed. In addition, coefficients were obtained from measurement of tracer concentration profiles through successive electropolishings of the specimens. The overall coefficients and those obtained from electropolishing experiments agree very well for Inconel at high temperatures and for Inor-8 at all temperatures. For temperatures below 750{sup o}C, coefficients obtained by electropolishing Inconel specimens are higher than the overall values; the bulk diffusion process is not uniform for this case. In all cases, good agreement was found between the overall diffusion coefficients and those extrapolated from published data at higher temperature with generally similar Cr-Ni alloys. Duplicate, polythermal loops of Inor-8 were used to circulate a non-corrosive fluoride melt containing Cr{sup 51} (as CrF{sub 2}). One of these loops was sacrificed to evaluate take-up of Cr{sup 51} by the alloy; the second was used to circulate a melt containing FeF{sub 2} to obtain measurable removal of Cr from the alloy. Good agreement between observed behaviour and that predicted from the measured diffusion coefficients was obtained; this agreement suggests that the self-diffusion coefficient for Cr is insensitive to changes in chromium content of the Inor-8 alloy. (author) [French] Lorsqu'on soumet les alliages Inconel ou Inor-8 a l'action d'un melange

  6. The radio universe

    International Nuclear Information System (INIS)

    Worvill, R.

    1977-01-01

    Elementary description of the development of radioastronomy, radio waves from the sun and planets, the use of radio telescopes and the detection of nebulae, supernova, radio galaxies and quasars is presented. A brief glossary of terms is included. (UK)

  7. Parálisis cerebral :

    OpenAIRE

    Cabrero Izquierdo, María del Carmen

    2012-01-01

    Se aborda el tema de la parálisis cerebral definiendo qué es, clasificando los tipos de parálisis dependiendo de la afectación y las características principales. Se explican algunos de sus tratamientos, se dan sistemas alternativos y/o aumentativos de comunicación para un alumno con PC (parálisis cerebral).

  8. Preparation and properties of thin films used in activity determinations with a 4 {pi} counter; Preparation et proprietes des films minces utilises dans les determinations d'activite au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Jannez, M.; Le Gallic, Y.; Thenard, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Comparative study of various methods of preparing thin films, for use as source holders in the 4 {pi} counter, and of measuring their thickness. Comparative study of various properties: mechanical resistance; heat resistance; ageing; resistance of rhodopas, polystyrene, formvar and cellulose acetate films to the action of various chemical agents. (author) [French] Etude comparee de divers procedes de preparation de films minces, destines a etre utilises comme supports de sources dans le compteur 4 {pi} et de la mesure de leur epaisseur. Etude comparee de diverses proprietes: resistance mecanique; resistance a la chaleur; vieillissement; resistance a l'action de divers agents chimiques de films de rhodopas, polystyrene, formvar et acetate de cellulose. (auteur)

  9. Preparation and properties of thin films used in activity determinations with a 4 {pi} counter; Preparation et proprietes des films minces utilises dans les determinations d'activite au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Jannez, M; Le Gallic, Y; Thenard, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Comparative study of various methods of preparing thin films, for use as source holders in the 4 {pi} counter, and of measuring their thickness. Comparative study of various properties: mechanical resistance; heat resistance; ageing; resistance of rhodopas, polystyrene, formvar and cellulose acetate films to the action of various chemical agents. (author) [French] Etude comparee de divers procedes de preparation de films minces, destines a etre utilises comme supports de sources dans le compteur 4 {pi} et de la mesure de leur epaisseur. Etude comparee de diverses proprietes: resistance mecanique; resistance a la chaleur; vieillissement; resistance a l'action de divers agents chimiques de films de rhodopas, polystyrene, formvar et acetate de cellulose. (auteur)

  10. Quality in the billing cycle remote reading through radio frequency walk-by system and prepayment: technical and initial reliability results, cost vs benefit analysis, end user satisfaction; La qualite dans le cycle de facturation. Telereleve HF des compteurs et compteurs a fiches prechargees: resultats thechniques, premieres verifications de fiabilite, rapport cout - benefices, interets et satisfaction des clients

    Energy Technology Data Exchange (ETDEWEB)

    Dho, V. [Gruppo Italcogim (Italy); Hensemberger, F. [Schlumberger Industries (Italy)

    2000-07-01

    This document, taking as a starting point the needs brought about by the evolution of the gas market, shows two proposals for technological innovations to be applied to company processes, to increase the quality and the opportunities supplied to clients for the gas distribution service. This article will deal with in particular the rationalization of the billing process giving a wider interpretation than the one commonly followed. As for the first proposal - the remote reading of domestic meters - the experimental project carried out on a sample of Italcogim clients is analysed in detail, as well as their related technical results regarding the efficiency and effectiveness of the technology used. An evaluation quality criteria on the suitability of the use of the new remote reading system is also highlighted. The second proposal covers the rechargeable card system, with a description of the technical and economic planning applied to the pilot project which will start in the near future. (authors)

  11. Self-Absorption Studies with a 4 {pi} {beta}-Proportional Flow Counter; Etudes sur l'autoabsorption avec un compteur {beta} 4 {pi} proportionnel a courant; Izuchenie samopogloshcheniya pri pomoshchi {beta} proportsional'no-potochnogo 4 {pi} schetchika; Estudios sobre autoabsorcion con un contador de flujo proporcional {beta}4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Yaffe, L; Fishman, J B [Radiochemistry Laboratory, Dept. of Chemistry, McGill University, Montreal, Quebec (Canada)

    1960-06-15

    Self-absorption studies of {beta} emitters have been made by means of the techniques outlined by Pate and Yaffe [Can. J. Chem. 34, 265 (1956)]. Volatile compounds of H''3, C''1''4, Co''6''0, Hg''2''0''3, As''7''7, and P{sup 32} (E{sub max} ranging from 0.018 to 1.7 MeV) were distilled on to thin VYNS mounts and the self-absorption characteristics determined. An empirically determined series of curves relating E{sub max}, source thickness, and self-absorption is given. The self-absorption data have been subjected to a theoretical analysis for counters of small angle and 4{pi} geometry. The experimentally determined self-absorption curves for 4 {pi} geometry lie in between the theoretical small angles and 4 {pi} geometry curves. (author) [French] Des etudes sur l'autoabsorption des emetteurs {beta} ont ete faites selon les techniques indiquees par Pate and Yaffe [Can. J. Chem. 34, 265 (1956)]. Des composes volatils de H{sup 3}, S{sup 14}, Co{sup 60}, Hg{sup 203}, As{sup 77} et P{sup 32} (E{sub max} allant de 0,018 a 1,7 MeV), ont ete recueillis par distillation sur des supports minces en resine vynilique (VYNS) et les caracteristiques de l'autoabsorption ont ete determinees. Le memoire contient une serie de courbes determinees empiriquement, qui donnent les relations entre E{sub max} l'epaisseur de la source et l'autoabsorption . Les donnees sur l'autoabsorption ont fait l'objet d'une analyse theorique pour les compteurs a geometrie de petit angle solide et 4 {pi}. Les courbes d'auto- absorption determinees experimentalemen t pour la geometrie 4 {pi} sont comprises entre les courbes theoriques correspondant a la geometrie de petit angle solide et a la geometrie 4 {pi}. (author) [Spanish] Les autores han estudiado la autoabsorcion de los emisores {beta} utilizando las tecnicas descritas por Pate y Yaffe [Can. J. Chem. 34, 265 (1956)]. Han destilado compuestos volatiles de H{sup 3}, S{sup 14}, So{sup 60}, Hg{sup 203}, As{sup 77} y P{sup 32} (E{sub max} comprendida

  12. Elusloom lennukiga puhkusele / Inge Parring

    Index Scriptorium Estoniae

    Parring, Inge

    2003-01-01

    Ilmunud ka: Delovõje Vedomosti 1. okt. lk. 13. Air Cargo Estonia/ACE Logisticsi müügijuht Inge Parring tutvustab elusloomade transpordivõimalusi. Vt. samas: Loomade transportimiseks vajalikud dokumendid

  13. Par Pond vegetation status 1996

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned

  14. Impact of cognitive radio on radio astronomy

    NARCIS (Netherlands)

    Bentum, Marinus Jan; Boonstra, A.J.; Baan, W.A.

    2010-01-01

    The introduction of new communication techniques requires an increase in the efficiency of spectrum usage. Cognitive radio is one of the new techniques that fosters spectrum efficiency by using unoccupied frequency spectrum for communications. However, cognitive radio will increase the transmission

  15. Fast Radio Bursts

    Indian Academy of Sciences (India)

    Akshaya Rane

    2017-09-12

    ) which were first discovered a decade ago. Following an introduction to radio transients in general, including pulsars and rotating radio transients, we discuss the discovery of FRBs. We then discuss FRB follow-up ...

  16. A new scintillation counter with very fast resolving time (1961); Nouveau compteur a scintillation a tres faible temps de resolution (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The rare gases used as scintillators are characterized by their short time of luminescence and by the linearity of their response as a function of the total energy imparted to the gas by the incident particle. It is possible with these scintillators, when associated with a fast response photomultiplier, to solve certain problems of nuclear physics demanding a linear detector with a very fast resolving time (a few nanoseconds). Two examples of the construction of this apparatus are described. The results obtained and future possibilities are briefly outlined. (author) [French] Les gaz rares utilises comme scintillateurs sont caracterises par leur faible duree de luminescence et par la linearite de leur reponse en fonction de l'energie totale cedee au gaz par la particule incidente. Ces scintillateurs, associes a un photomultiplicateur a une reponse rapide, permettent de resoudre certains problemes de physique nucleaire dans lesquels un detecteur lineaire a tres faible temps de resolution (quelques nanosecondes) se revele indispensable. Deux exemples de realisation sont decrits. Les resultats obtenus et les possibilites futures sont brievement exposes. (auteur)

  17. La radio digital

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Cortés S.

    2015-01-01

    Full Text Available La radio digital es un producto de la llamada convergencia digital. Las nuevas tecnologías interconectadas permiten la aparición de nuevos modos de audiencia y la implementación de herramientas versátiles. Habla del problema de los estándares, de la radio satelital, la radio digital terrestre, las radios internacionales, la interactividad.

  18. Commercial Radio as Communication.

    Science.gov (United States)

    Rothenbuhler, Eric W.

    1996-01-01

    Compares the day-to-day work routines of commercial radio with the principles of a theoretical communication model. Illuminates peculiarities of the conduct of communication by commercial radio. Discusses the application of theoretical models to the evaluation of practicing institutions. Offers assessments of commercial radio deriving from…

  19. Ham radio for dummies

    CERN Document Server

    Silver, H Ward

    2013-01-01

    An ideal first step for learning about ham radio Beyond operating wirelessly, today's ham radio operators can transmit data and pictures; use the Internet, laser, and microwave transmitters; and travel to places high and low to make contact. This hands-on beginner guide reflects the operational and technical changes to amateur radio over the past decade and provides you with updated licensing requirements and information, changes in digital communication (such as the Internet, social media, and GPS), and how to use e-mail via radio. Addresses the critical use of ham radio for replacing downe

  20. Radiography of Spanish Radio

    Directory of Open Access Journals (Sweden)

    Dra. Emma Rodero Antón

    2007-01-01

    Full Text Available In its eighty years of existence, radio has been always characterized to adapt to the social, cultural and technological transformations. Thus it has been until this moment. Nevertheless, some years ago, the authors and professionals of this medium have been detecting a stagnation that affects to its structure. At a time in continuous technological evolution, radio demands a deep transformation. For that reason, from the conviction of which the future radio, public and commercial, will necessarily have to renew itself, in this paper we establish ten problems and their possible solutions to the radio crisis in order to draw an x-ray of radio in Spain. Radio has future, but it is necessary to work actively by it. That the radio continues being part of sound of our life, it will depend on the work of all: companies, advertisers, professionals, students, investigators and listeners.

  1. Vote par sondage uniforme incorruptible

    OpenAIRE

    Blanchard , Nicolas

    2016-01-01

    International audience; Introduit en 2012 par David Chaum, le vote par sondage uniforme (random-sample voting) est un protocole de vote basé sur un choix d'une sous-population représentative , permettant de limiter les coûts tout en ayant de nombreux avantages, principalement lorsqu'il est couplé a d'autres techniques comme ThreeBallot. Nous analysons un problème de corruptibilité potentielle où les votants peuvent vendre leur vote au plus offrant et proposons une variation du protocole reméd...

  2. Senior radio listeners

    DEFF Research Database (Denmark)

    Blaakilde, Anne Leonora

    Radiobroadcasting and the hardware materialization of radio have during the 20th century changed significantly, which means that senior radio listeners have travelled along with this evolution from large, impressive radio furnitures to DAB and small, wireless, mobile devices, and from grave...... and solemn radio voices to lightharted, laughing and chatting speakers. Senior radio listerners have experienced the development and refinements of technique, content and genres. It is now expected of all media users that they are capable of crossing media, combining, juggling and jumping between various...... media platforms, not the least when listening to radio. The elder generation is no exception from this. Recently, for instance, the Danish public broadcast DR has carried out an exodus of programmes targeted for the senior segment. These programmes are removed from regular FM and sent to DAB receivers...

  3. Determination of the sanguine iodine content by activation analysis (1962); Determination de l'iode sanguin par analyse d'activation (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Kellershohn, C; Comar, D; Le Poec, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    Two methods of measuring the iodine content of the blood by activation analysis after 30 min irradiation in a flux of 6.10{sup 12} n/cm{sup 2}.s are described. One method includes a chemical separation of iodine before irradiation. The radioactivity of this specimen is determined on the basis of the amplitude of the iodine 128 photoelectric peak measured by {gamma}-spectrometry. The sensitivity of this method is about 10{sup -8} g. The other includes chemical separation after irradiation, and radioactivity is subsequently measured with a Geiger-Muller counter. The sensitivity of this second method is about 10{sup -10} g, sufficient for determination of the plasmatic mineral content. The advantages of activation analysis over the conventional method based on colorimetric measurement of the catalytic action of iodine in the oxidation of arsenious anhydride with ceric sulphate are discussed. Initial results obtained with this new form of analysis are detailed as are also the possibilities of measuring plasmatic proteic iodine by scintillation spectrometry without prior chemical separation. (authors) [French] Deux methodes de dosage de l'iode sanguin par analyse d'activation apres irradiation de 30 minutes a 6.10{sup 12} n/cm{sup 2} s sont decrites. L'une comprend une separation chimique de l'iode avant l'irradiation et la mesure de la radioactivite est effectuee a partir de l'amplitude du pic photo-electrique de l'iode 128 obtenu par spectrometrie-{gamma}. Sa sensibilite est de l'ordre de 10{sup -8} g. L'autre comprend une separation chimique de l'iode apres l'irradiation et la radioactivite de l'iode-128 est mesuree par comptage-{beta} avec un compteur Geiger. Sa sensibilite est de l'ordre de 10{sup -10} g, permettant d'envisager le dosage de l'iode mineral plasmatique. Les avantages de l'analyse d'activation sur la methode classique, basee sur la mesure colorimetrique de l'action catalytique de l'iode dans l'oxydation de l'anhydride arsenieux par le sulfate cerique

  4. Determination of the ruthenium, cerium and zirconium radio-activity of sea-water by carrying-over and adsorption using manganese dioxide; Determination de la radioactivite de l'eau de mer en ruthenium, cerium, zirconium par en- trainement et adsorption au moyen du bioxyde de manganese

    Energy Technology Data Exchange (ETDEWEB)

    Guegueniat, P [Commissariat a l' Energie Atomique, La Hague (France). Centre d' Etudes Nucleaires

    1967-07-01

    Principle: Manganese dioxide is precipitated in the medium to be analyzed by the action of hydrogen peroxide on potassium permanganate. Large volumes of sea-water are treated by successive adsorptions of 80 litre fractions using always the same precipitate obtained from 30 g of potassium permanganate. Some examples are given concerning the analysis of 80, 160, 1000 and 2000 litres of water. Advantages of the technique: The existence of low activities due to ruthenium, zirconium and cerium can be demonstrated if sufficiently large volumes of water are treated. (author) [French] Principe: Le bioxyde de manganese est precipite dans le milieu a analyser par action de l'eau oxygenee sur le permanganate de potassium. Le traitement de grands volumes d'eau de mer se fait par adsorptions successives de fractions de 80 litres en utilisant toujours le meme precipite obtenu a partir de 30 g de permanganate de potassium. Quelques exemples ayant trait a des analyses de 80, 160, 1000, 2000 litres sont donnes. Interet de la technique: De faibles activites dues au Ruthenium, Zirconium, Cerium peuvent etre mises en evidence en traitant des volumes d'eau suffisants. (auteur)

  5. Par Pond Fish, Water, and Sediment Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Paller, M.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

  6. Par Pond Fish, Water, and Sediment Chemistry

    International Nuclear Information System (INIS)

    Paller, M.H.; Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond

  7. A gaseous scintillation counter filled with He{sup 3} for neutron spectrometry; Compteur a scintillateur gazeux rempli de {sup 3}He pour la spectrometrie des flux de neutrons; Gazovyj stsintillyatsionnyj schetchik napolnennyj He{sup 3} dlya spektrometrii potokov nejtronov; Contador de centelleador gaseoso cargado con helio-3 para la espectrometria neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Baldin, S A; Matveev, V V

    1962-04-15

    The paper describes a gas plant and gaseous scintillation counter, and gives the results of experiments on the recording and spectrometry of neutron beams using a gaseous scintillation counter filled with a mixture of 10% xenene and 90% helium-3 at an overall pressure of 20 ata. Data are given on the design of the gas plant, which makes it possible to operate the counter continuously over long periods of time, as well as providing the required gas mixtures at overall pressures of up to 60 atm and ensuring constant freedom of the gas from contamination. In addition, the paper presents the results of research on the counter's energy resolution and linearity at different energy levels and indicates its efficiency in gamma fields of intensity up to 3 r/h; the possibility of extending the working energy-range of gaseous scintillation counters filled with helium-3 is also considered. (author) [French] FLes auteurs decrivent un compteur a scintillateur gazeux ainsi que les resultats des experiences d'enregistrement et de spectrometrie des flux de neutrons qui ont ete faites au moyen d'un compteur a scintillateur gazeux rempli d'un melange de 10% de xenon et de 90% d'helium-3 sous une pression de 20 atmospheres. Ils exposent les donnees relatives a la construction d'un appareillage qui assure le fonctionnement ininterrompu du compteur durant un laps de temps prolonge, l'obtention des melanges de gaz indispensables sous une pression totale de 60 atmospheres et l'epuration continue du gaz. En outre, ils examinent les resultats de l'etude du pouvoir de resolution en energie et de la linearite du compteur en fonction de l'energie, le fonctionnement du compteur dans les champs de rayonnement gamma d'une intensite allant jusqu'a 3 r/h, ainsi que la possibilite d'elargir la gamme d'energie dans laquelle on peut employer des compteurs a scintillateurs gazeux de {sup 3}He. (author) [Spanish] En esta memoria se describe un aparato de suministro de gas y un contador de centelleador

  8. Ionosphere and Radio Communication

    Indian Academy of Sciences (India)

    The upperionosphere is used for radio communication and navigationas it reflects long, medium, as well as short radio waves. Sincesolar radiation is the main cause of the existence of ionosphere,any variation in the radiations can affect the entireradio communication system. This article attempts to brieflyintroduce the ...

  9. Writing for Radio.

    Science.gov (United States)

    Tupper, Marianna S.

    1995-01-01

    Describes a 24-hour commercial radio station simulation class project for eighth-grade language arts. Students wrote their own scripts, chose music and were disc jockeys on their own music and talk shows, and prepared news and traffic reports. Guest speakers from actual commercial radio came in to discuss issues such as advertising, censorship,…

  10. Valuing commercial radio licences

    NARCIS (Netherlands)

    Kerste, M.; Poort, J.; van Eijk, N.

    2015-01-01

    Within the EU regulatory framework, licensees for commercial radio broadcasting may be charged a fee to ensure optimal allocation of scarce resources but not to maximize public revenues. While radio licence renewal occurs in many EU countries, an objective, model-based approach for setting licence

  11. The Radio Jove Project

    Science.gov (United States)

    Thieman, J. R.

    2010-01-01

    The Radio love Project is a hands-on education and outreach project in which students, or any other interested individuals or groups build a radio telescope from a kit, operate the radio telescope, transmit the resulting signals through the internet if desired, analyze the results, and share the results with others through archives or general discussions among the observers. Radio love is intended to provide an introduction to radio astronomy for the observer. The equipment allows the user to observe radio signals from Jupiter, the Sun, the galaxy, and Earth-based radiation both natural and man-made. The project was started through a NASA Director's Discretionary Fund grant more than ten years ago. it has continued to be carried out through the dedicated efforts of a group of mainly volunteers. Dearly 1500 kits have been distributed throughout the world. Participation can also be done without building a kit. Pre-built kits are available. Users can also monitor remote radio telescopes through the internet using free downloadable software available through the radiosky.com website. There have been many stories of prize-winning projects, inspirational results, collaborative efforts, etc. We continue to build the community of observers and are always open to new thoughts about how to inspire the observers to still greater involvement in the science and technology associated with Radio Jove.

  12. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  13. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system.

    Science.gov (United States)

    Hu, Longhua; Vecchiarelli, Anthony G; Mizuuchi, Kiyoshi; Neuman, Keir C; Liu, Jian

    2015-12-22

    The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos-an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria.

  14. Unlocking radio broadcasts

    DEFF Research Database (Denmark)

    Skov, Mette; Lykke, Marianne

    2012-01-01

    This poster reports the preliminary results of a user study uncovering the information seeking behaviour of humanities scholars dedicated to radio research. The study is part of an interdisciplinary research project on radio culture and auditory resources. The purpose of the study is to inform...... the design of information architecture and interaction design of a research infrastructure that will enable future radio and audio based research. Results from a questionnaire survey on humanities scholars‟ research interest and information needs, preferred access points, and indexing levels are reported....... Finally, a flexible metadata schema is suggested, that includes both general metadata and highly media and research project specific metadata....

  15. Radio y elecciones

    Directory of Open Access Journals (Sweden)

    Alma Rosa Alva de la Selva

    2000-01-01

    Full Text Available En este trabajo se analiza el comportamiento de la radio en México ante la contienda electoral de julio de 2000. Se examina el papel de la radio como espacio para la discusión política, así como el tratamiento informativo que hizo del tema. Asimismo, se analiza la posible repercusión de factores de reciente surgimiento en el panorama radiofónico para un manejo más autónomo de la información política en la radio

  16. Electrical characteristics of sphere-plane type spark counters; Caracteristiques electriques de compteurs a etincelles du type sphere-plan; Ehlektricheskie kharakteristiki iskrovykh schetchikov tipa shar-ploskost'; Caracteristicas electricas de los contadores de chispas del tipo esfera-plano

    Energy Technology Data Exchange (ETDEWEB)

    Laborie, P; Blanc, D [Centre de Physique Nucleaire, Faculte des Sciences de Toulouse (France)

    1962-04-15

    The authors describe here the mechanical construction and operating characteristics of spark detectors using a small (0.30 mm) diameter sphere as anode, set opposite to a plane cathode and working by the ''corona'' effect, in air at atmospheric pressure. Counting characteristics are very similar to those of Rosenblum-type anode wire detectors. However, the sphere counter has a certain superiority over the Rosenblum counter inherent in its geometry : (a) there sidual current (background) is low and the release of ozone and nitrous oxides during the spark is not of great significance; (b) its self-capacity being very small, the detector gives a faster response; (c) unlike in the case of wire counters, efficiency is independent of particle incidence direction; (d) its sensitive volume, that of a solid of revolution around the axis of symmetry of the detector, amounts to a few cubic millimetres and, being very clearly defined, permits realization of accurate telescopic devices. (author) [French] Les auteurs decrivent la realisation mecanique et les caracteristiques de fonctionnement de detecteurs a etincelles utilisant comme anode une sphere de petit diametre (0,30 mm), disposee en regard d'une cathode plane, et fonctionnant en regime d'effet , dans l'air sous la pression atmospherique. Les caracteristiques de comptage sont voisines de celles des detecteurs a fil anodique, du type Rosenblum. Le compteur a sphere presente cependant sur le compteur de Rosenblum un certain nombre d'avantages lies a sa geometrie: a) le courant residuel (bruit de fond) est faible, et le degagement d'ozone et d'oxydes de l'azote lors des etincelles est peu considerable; b) sa capacite propre etant tres petite, le detecteur presente une reponse plus rapide; c) l'efficacite est independante de la direction d'incidence de la particule, contrairement a ce qui a lieu pour les compteurs a fil; d) le volume sensible de revolution autour de l'axe de symetrie du detecteur, qui est de

  17. A Procedure for the Determination of Alpha-Emitting Plutonium in Urine Using a Solid-State Counter; Methode de Determination du Plutonium Emetteur Alpha Present dans l'Urine, au Moyen d'un Compteur a Semi-Conducteurs; Metod opredeleniya al'fa-izlucheniya plutoniya v moche s pomoshch'yu poluprovodnikovogo schetchika; Procedimiento para Determinar la Actividad Alfa del Plutonio en la Orina con Ayuda de un Contador de Estado Solido

    Energy Technology Data Exchange (ETDEWEB)

    Sandalls, F. J.; Morgan, A. [Health Physics and Medical Division, Atomic Energy Research Establishment, Harwell (United Kingdom)

    1964-10-15

    . La methpde qu'ils ont finalement adoptee consiste a incinerer l'urine et a dissoudre le residu dans de l'acide chlorhydrique. A partir de cette solution,' le plutonium (IV) est coprecipite avec du cupferrate de fer et extrait au moyen de chloroforme. Apres evaporation de celui-ci, le residu est oxyde et dissous dans l'acide chlorhydrique, puis le fer est extrait au moyen d'ether di-isopropy- lique. La phase aqueuse contenant le plutonium est evaporee et dissoute dans une solution de sulfate acide d'ammonium, d'ou le plutonium est depose par electrolyse sur de l'acier inoxydable. Au stade du depot . electrolytique, on recueille dans l'ensemble 84 {+-} 7% du plutonium contenu. Le plutonium depose par electrolyse est mesure au moyen d'un detecteur a semi-conducteur (diode a jonction au silicium) dans un compteur concu a cette fin. Le faible mouvement propre de ce type de compteur est encore efficacement reduit si l'on ne compte que les particules alpha ayant des energies comprises entre 4,2 et 5,4 MeV. La bonne resolution que l'on peut obtenir avec de minces couches de plutonium deposees par electrolyse permet d'utiliser ce canal etroit en ne faisant que de faibles pertes de rendement de comptage. En ne comptant que dans cette gamma d'energies peu etendue, l'activite due a la presence de reactifs et d'autres agents de contamination emetteurs alpha residuels dans l'urine, qui n'est pas entierement decontaminee, se trouve egalement reduite de moitie et atteint un peu plus de 0,01 pc par echantillon preleve sur les urines recueillies pendant 24 h. La limite de detection a l'aide de cette methode est d'environ 0, 025 pc de {sup 239}Pu. (author) [Spanish] La memoria describe un metodo para determinaciones corrientes de plutonio en la orina. Tambien resume las investigaciones que llevaron a establecer este procedimiento y en las que se compararon diversas tecnicas de concentracion, purificacion y deposito electrolitico del plutonio. Con arreglo al procedimiento adoptado en

  18. Recherche documentaire par titrage automatique

    OpenAIRE

    Lopez , Cédric; Prince , Violaine; Roche , Mathieu

    2011-01-01

    Nous proposons dans cet article un système facilitant la recherche d'information dans un ensemble de documents textuels, basé sur le titrage (et sous-titrage) automatique. Ce dernier peut se révéler crucial, par exemple, dans le cadre de la problématique de l'accessibilité des pages web (norme W3C). Notre processus de titrage automatique consiste à extraire des syntagmes nominaux pertinents dans les textes, pouvant constituer des titres ou sous-titres candidats. Une approche originale combina...

  19. Social cognitive radio networks

    CERN Document Server

    Chen, Xu

    2015-01-01

    This brief presents research results on social cognitive radio networks, a transformational and innovative networking paradigm that promotes the nexus between social interactions and cognitive radio networks. Along with a review of the research literature, the text examines the key motivation and challenges of social cognitive radio network design. Three socially inspired distributed spectrum sharing mechanisms are introduced: adaptive channel recommendation mechanism, imitation-based social spectrum sharing mechanism, and evolutionarily stable spectrum access mechanism. The brief concludes with a discussion of future research directions which ascertains that exploiting social interactions for distributed spectrum sharing will advance the state-of-the-art of cognitive radio network design, spur a new line of thinking for future wireless networks, and enable novel wireless service and applications.

  20. NOAA Weather Radio

    Science.gov (United States)

    del tiempo incluido. Si eres quieres ser avisado de las advertencias y relojes de día o de noche, un Weather Radio relojes son independientes o basadas en el Condado (parroquia basados en Luisiana), aunque

  1. The digital sport radio.

    Directory of Open Access Journals (Sweden)

    Hilario José ROMERO BEJARANO

    2014-07-01

    Full Text Available Radio has been immersed in recent years in a phase of technological integration and business of multimedia, as well as diversification of systems and channels for broadcasting. In addition, Internet has been consolidated as the platform of digital radio that more has evolved as a result of its continued expansion. However, the merger radio-Internet must be understood as a new form of communication, and not solely as a new complementary medium. In this context, it is of great interest to analyze that transformations in the way of reception, contents, languages, programs and schedules, has brought with it for the radio that integration. To this end is taken as main reference the sports areas, a key aspect and broadly representative of the current broadcasting landscape.

  2. Music, radio and mediatization

    DEFF Research Database (Denmark)

    Michelsen, Morten; Krogh, Mads

    2016-01-01

    of mediatization where media as such seem to be ascribed agency. Instead, we consider historical accounts of music–radio in order to address the complex nonlinearity of concrete processes of mediatization as they take place in the multiple meetings between a decentred notion of radio and musical life.......Mediatization has become a key concept for understanding the relations between media and other cultural and social fields. Contributing to the discussions related to the concept of mediatization, this article discusses how practices of radio and music(al life) influence each other. We follow Deacon......’s and Stanyer’s advice to supplement the concept of mediatization with ‘a series of additional concepts at lower levels of abstraction’ and suggest, in this respect, the notion of heterogeneous milieus of music–radio. Hereby, we turn away from the all-encompassing perspectives related to the concept...

  3. ITSY Handheld Software Radio

    National Research Council Canada - National Science Library

    Bose, Vanu

    2001-01-01

    .... A handheld software radio platform would enable the construction of devices that could inter-operate with multiple legacy systems, download new waveforms and be used to construct adhoc networks...

  4. Structure in radio galaxies

    International Nuclear Information System (INIS)

    Breugel, W. van.

    1980-01-01

    It is shown that radio jets are a rather common phenomenon in radio galaxies. Jets can be disguised as trails in head-tail sources, bridges in double sources or simply remain undetected because of lack of resolution and sensitivity. It is natural to associate these jets with the channels which had previously been suggested to supply energy to the extended radio lobes. The observations of optical emission suggest that a continuous non-thermal spectrum extending from 10 9 to 10 15 Hz is a common property of jets. Because significant amounts of interstellar matter are also observed in each of the galaxies surveyed it seems that models for jets which involve an interaction with this medium may be most appropriate. New information about the overall structure of extended radio sources has been obtained from the detailed multifrequency study with the WSRT. (Auth.)

  5. Wireless radio a history

    CERN Document Server

    Coe, Lewis

    2006-01-01

    ""Informative...recommended""--Choice; ""interesting...a good read...well worth reading""--Contact Magazine. This history first looks at Marconi's wireless communications system and then explores its many applications, including marine radio, cellular telephones, police and military uses, television and radar. Radio collecting is also discussed, and brief biographies are provided for the major figures in the development and use of the wireless.

  6. ¿Radios ciudadanas?

    OpenAIRE

    López Vigil, José Ignacio

    1998-01-01

    Educativas, sindicales, populares, comunitarias, libres, rebeldes, participativas, alternativas, alterativas, han sido las denominaciones de la radio cuando su proyecto está al servicio de la gente. Palabras apropiadas y nobles -dice elautor-pero devaluadas, a las que ahora se agrega la radio ciudadana, para relievarla como ejercicio depoder y espacio de verdadera participación de la genteenla vida de su nación.

  7. The activity of {gamma}-emitters as measured by ionisation chambers the determination of the specific emission coefficient {gamma} for some radio-elements (1961); Mesure de l'activite des emetteurs {gamma} par chambre d'ionisation. Determination du coefficient specifique d'emission {gamma} de quelques radioelements (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-06-15

    The object of this work is to study techniques of measurement using the gamma ionisation chamber, making it possible either to measure the activities of radioactive sources, or to determine the specific emission coefficient {gamma} (or the coefficient K) of a given radioelement. The ionisation chambers studied belong to two categories: graphites cavity-chambers, and 4 {pi} {gamma} chambers. For the cavity-chamber measurements, the different correction factors of which account must be taken have been calculated, in particular the geometric and hygrometric corrections. The absorption and auto-absorption corrections have led to the introduction of the notion of the 'effective energy {gamma}' of a radioelement. In the case of 4 {pi} {gamma} chambers, it has been shown that appropriately shaped electrodes make it possible to improve their performances. One of the chambers described permits the measurement of {beta} emitters using the associated Bremsstrahlung. In order to measure the K coefficient of some radioelements, it has been found useful a 4 {pi} {gamma} chamber with graphite walls, the measurement being carried out by comparison with a radium standard. The validity of the method was checked with radioelements for whom the K coefficient values are well-known ({sup 24}Na, {sup 60}Co, {sup 131}I, {sup 198}Au). For other radioelements, the following values were obtained (expressed in r cm{sup 3} mc{sup -1} h{sup -1}): {sup 51}Cr: 0,18; {sup 56}Mn: 8,8; {sup 65}Zn: 3,05; {sup 124}Sb: 9,9; {sup 134}Cs: 9,3; {sup 137}Cs: 3,35; {sup 141}Ce: 0,46; {sup 170}Tm: 0,023; {sup 192}Ir: 24,9; {sup 203}Hg: 1,18; These values have been corrected for the contribution to the dose of the fluorescent radiation which may be emitted by the source, except in the case of Tm{sup 170}. In the last part of this work, the performances of the different electro-metric devices used were compared. (author) [French] Le but de ce travail est d'etudier les techniques de mesure par

  8. The activity of {gamma}-emitters as measured by ionisation chambers the determination of the specific emission coefficient {gamma} for some radio-elements (1961); Mesure de l'activite des emetteurs {gamma} par chambre d'ionisation. Determination du coefficient specifique d'emission {gamma} de quelques radioelements (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-06-15

    The object of this work is to study techniques of measurement using the gamma ionisation chamber, making it possible either to measure the activities of radioactive sources, or to determine the specific emission coefficient {gamma} (or the coefficient K) of a given radioelement. The ionisation chambers studied belong to two categories: graphites cavity-chambers, and 4 {pi} {gamma} chambers. For the cavity-chamber measurements, the different correction factors of which account must be taken have been calculated, in particular the geometric and hygrometric corrections. The absorption and auto-absorption corrections have led to the introduction of the notion of the 'effective energy {gamma}' of a radioelement. In the case of 4 {pi} {gamma} chambers, it has been shown that appropriately shaped electrodes make it possible to improve their performances. One of the chambers described permits the measurement of {beta} emitters using the associated Bremsstrahlung. In order to measure the K coefficient of some radioelements, it has been found useful a 4 {pi} {gamma} chamber with graphite walls, the measurement being carried out by comparison with a radium standard. The validity of the method was checked with radioelements for whom the K coefficient values are well-known ({sup 24}Na, {sup 60}Co, {sup 131}I, {sup 198}Au). For other radioelements, the following values were obtained (expressed in r cm{sup 3} mc{sup -1} h{sup -1}): {sup 51}Cr: 0,18; {sup 56}Mn: 8,8; {sup 65}Zn: 3,05; {sup 124}Sb: 9,9; {sup 134}Cs: 9,3; {sup 137}Cs: 3,35; {sup 141}Ce: 0,46; {sup 170}Tm: 0,023; {sup 192}Ir: 24,9; {sup 203}Hg: 1,18; These values have been corrected for the contribution to the dose of the fluorescent radiation which may be emitted by the source, except in the case of Tm{sup 170}. In the last part of this work, the performances of the different electro-metric devices used were compared. (author) [French] Le but de ce travail est d'etudier les techniques de mesure par chambre d

  9. Classics in radio astronomy

    CERN Document Server

    Sullivan, Woodruff Turner

    1982-01-01

    Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave­ lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro­ ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of re...

  10. Absolute measurement of a standard thermal-neutron flux using gold-detector activation; Mesure absolue d'un flux etalon de neutrons thermiques par activation de detecteurs d'or

    Energy Technology Data Exchange (ETDEWEB)

    Paternot, Y [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1967-02-15

    The density of neutrons in a standard stacking is determined between the zero-energy and the cut-off energy of 1 mm thick cadmium unit using a gold detector. Its absolute activity is measured using a 4 {pi} {beta} counter calibrated for 4 {pi} {beta},{gamma} coincidence by counting strongly active sources. The correction factor F due to the disintegration process for the gold is determined experimentally. {phi}{sub 0} = N{sub 0} {sup E}Cd{sub V0} = 6495 {+-} 1.5 per cent n/cm{sup 2}/s. (author) [French] La densite de neutrons dans un empilement etalon est determinee entre l'energie zero et l'energie de coupure d'un boitier de cadmium de 1 mm d'epaisseur au moyen d'un detecteur d'or. Son activite absolue est mesuree a l'aide d'un compteur 4 {pi} {beta} etalonne en coincidence 4 {pi} {beta},{gamma} par comptage de sources fortement actives. Le facteur de correction F d au schema de desintegration de l'or est determine experimentalement. {phi}{sub 0} = N{sub 0} {sup E}Cd{sub V0} = 6495 {+-} 1.5 pour cent n/cm{sup 2}/s. (auteur)

  11. Solar radio observations and interpretations

    International Nuclear Information System (INIS)

    Rosenberg, H.

    1976-01-01

    The recent solar radio observations related to flares are reviewed for the frequency range of a few kilohertz to several gigahertz. The analysis of the radio data leads to boundary conditions on the acceleration processes which are responsible for the fast particles which cause radio emission. The role and cause of plasma turbulence at the plasma-frequency and at much lower frequencies is discussed in relation to the acceleration processes and the radio emission mechanisms for the various radio bursts. (author)

  12. SECHAGE DE PRODUITS GRANULAIRES PAR DESHYDRATATION PAR DETENTES SUCCESSIVES (DDS)

    OpenAIRE

    Abdulla , Galal; Mellouk , Hamid; Belghit , Abdelhamid; Allaf , Karim

    2009-01-01

    International audience; Dans cette étude, nous avons évalué les performances d'un nouveau procédé de séchage dans le cas du liège en granulés. Ce procédé (La déshydratation par détentes successives : DDS) consiste à soumettre le matériau liège dans une chambre hermétique aux variations cycliques de la pression. Chaque cycle est composé d'une compression et d'une décompression. La phase de compression est réalisée en injectant de l'air comprimé à température ambiante provenant d'un compresseur...

  13. A Low-Background Liquid-Scintlllation Counter for the Assay of Low-Specific Activity Tritiated Water; Compteur a scintillations a liquides, a faible mouvement propre, pour le dosage d'eau tritiee en faible activite specifique; ZHidkostnyj stsintillyatsionnyi schetchik s nizkim fonom dlya analiza nasyshchennoj tritiem vody s nizkoj udel'noj aktivnost'yu; Contador de centelleador liquido de reducida actividad de fondo para el analisis de agua pritiada de baja actividad especifica

    Energy Technology Data Exchange (ETDEWEB)

    Boyce, I S; Cameron, J F [Wantage Research Laboratory, Wantage (United Kingdom)

    1962-01-15

    In liquid-scintillation counting of tritiated water single photomultiplier counters and coincidence systems offer comparable sensitivities. To investigate low level counting a coincidence system was selected to avoid Uncertainties in the background due to single photon events arising from phosphorescence and chemiluminescenc e in the solution. With this system the background was found to be due largely to light originating in the photomultiplier photocathode. Using two photomultipliers with ''Pyrex'' photocathodes in contact in an 8 in thick iron shield experiments were conducted to determine the relative importance of the following possible courses of background : (a) Ionization and excitation of residual gas and of the semi-conductor dynode surfaces, particularly in regions where the current density is greatest. (b) Sparking, electroluminescence and field emission. (c) Positive ion feedback to the photocathode causing secondary electron emission. (d) Operation of the photocathode window itself as a phosphor for cosmic radiation, K{sup 40} beta particles or radiation from uranium daughter products. In particular it was found that contribution (c) was significantly lower than was previously supposed. Methods of minimizing these effects, including the use of quartz photocathodes, and special photomultipliers were investigated. In the finished design of counter the minimum detectable specific activity with a counting time of 30 min. is 6x10{sup 7} {mu}c/ml. (author) [French] Dans le dosage de l'eau tritiee au moyen d'un compteur a scintillations a liquides, les compteurs a photomultiplicateur unique et les ensembles a coincidences presentent une sensibilite du meme ordre. Pour faire des recherches sur la mesure des faibles activites, les auteurs ont choisi un dispositif monte en coincidence, afin d'eviter les incertitudes dans le mouvement propre causees par l'apparation de photons isoles, dus a la phosphorescence et a la chimioluminescenc e de la solution. Dans ce

  14. La preuve par le nombre

    Directory of Open Access Journals (Sweden)

    Hélène Verdier

    2012-04-01

    Full Text Available S’il en était besoin, la question des usages et de la finalité des résultats de l’inventaire général pourrait être abordée par le nombre : nombre d’œuvres répertoriées, de communes inventoriées, de clichés photographiques réalisés, de dossiers, de consultations des notices dans les bases de données… Les additions aujourd’hui sont éloquentes, mais elles laissent dans l’ombre le rôle de l’inventaire qui, en mettant en œuvre une démarche systématique de connaissance, participe à l’ identificatio...

  15. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2013-01-01

    This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

  16. Par Pond vegetation status Summer 1995 -- Summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  17. Galactic radio astronomy

    CERN Document Server

    Sofue, Yoshiaki

    2017-01-01

    This book is a concise primer on galactic radio astronomy for undergraduate and graduate students, and provides wide coverage of galactic astronomy and astrophysics such as the physics of interstellar matter and the dynamics and structure of the Milky Way Galaxy and galaxies. Radio astronomy and its technological development have led to significant progress in galactic astronomy and contributed to understanding interstellar matter and galactic structures. The book begins with the fundamental physics of radio-wave radiation, i.e., black body radiation, thermal emission, synchrotron radiation, and HI and molecular line emissions. The author then gives overviews of ingredients of galactic physics, including interstellar matter such as the neutral (HI), molecular hydrogen, and ionized gases, as well as magnetic fields in galaxies. In addition, more advanced topics relevant to the Galaxy and galaxies are also contained here: star formation, supernova remnants, the Galactic Center and black holes, galactic dynamics...

  18. Radio structure in quasars

    International Nuclear Information System (INIS)

    Barthel, P.D.

    1984-01-01

    In this thesis, observational attention is given to the extended extragalactic radio sources associated with quasars. The isolated compact radio sources, often identified with quasars, are only included in the discussions. Three aspects of the radio structure in quasars and their cosmic evolution are considered: a study of the parsec scale morphology in quasar cores, in relation to the extended morphologies; an investigation of possible epoch dependent hotspot properties as well as a more detailed investigation of this fine scale structure; a VLA project was carried out to obtain morphological information on scales of 0.5 arcsec on high redshift quasars and to investigate possible epoch dependent morphological properties. MERLIN observations at 0.1 arcsec resolution to supplement the VLA data were initiated. (Auth.)

  19. Radio Emission from Supernovae

    International Nuclear Information System (INIS)

    Weiler, Kurt W.; Panagia, Nino; Sramek, Richard A.; Van Dyk, Schuyler D.; Williams, Christopher L.; Stockdale, Christopher J.; Kelley, Matthew T.

    2009-01-01

    Study of radio supernovae over the past 27 years includes more than three dozen detected objects and more than 150 upper limits. From this work it is possible to identify classes of radio properties, demonstrate conformance to and deviations from existing models, estimate the density and structure of the circumstellar material and, by inference, the evolution of the presupernova stellar wind, and reveal the last stages of stellar evolution before explosion. It is also possible to detect ionized hydrogen along the line of sight, to demonstrate binary properties of the presupernova stellar system, and to detect dumpiness of the circumstellar material.

  20. Radio emission from Jupiter

    International Nuclear Information System (INIS)

    Velusamy, T.

    1976-01-01

    The basic features of the different radio emissions from the planet Jupiter are reviewed. These radio emissions characterized into three types as thermal, decimetric and decametric, are discussed. The coherent emission mechanism for the origin of the decametric bursts and the acceleration mechanism for relativistic electrons in the decimetric radiation have not been properly understood. The emissions are much related to the magnetic field of Jupiter. The system III rotation period for Jupiter has been calculated as 092 55 m 29.74 S. (A.K.)

  1. ¿Radios Comunitarias?

    OpenAIRE

    José Ignacio López Vigil

    2015-01-01

    Varias han sido las denominaciones dadas a la radio cuando su proyecto está al servicio de la gente. Palabras apropiadas pero devaluadas al decir del autor, a las que ahora se suma otras radios ciudadanas. Ciudadana para relievarla como ejercicio de poder y espacio de verdadera participación de la gente en la vida de su nación. Ciudadanos son los que piensan con cabeza propia y pesan en la opinión pública. Presenta una sinopsis de la historia de éstas desde 1974. Señala que la competencia obl...

  2. Spectrum management and radio resource management considering cognitive radio systems

    NARCIS (Netherlands)

    Haartsen, J.C.; Wieweg, Lasse; Huschke, Jörg

    2005-01-01

    International fora and some national administrations define a cognitive radio (CR) as a pioneering radio communication system that would be capable of altering and adapting its transmitter and receiver parameters based on communication and the exchange of information with related detectable radio

  3. Compact radio sources

    International Nuclear Information System (INIS)

    Altschuler, D.R.

    1975-01-01

    Eighty-seven compact radio sources were monitored between 1971 and 1974 with the National Radio Astronomy Observatory interferometer. Both flux density and polarization were measured at intervals of about one month at wavelengths of 3.7 and 11.1 cms. Forty-four sources showed definite variability in their total and/or polarized flux density. The variations in polarization were of a shorter time scale than the corresponding flux density variations. Some of the qualitative features of an expanding source model were observed. The data suggest that some form of injection of relativistic electrons is taking place. The absence of significant depolarization in the variable sources indicates that only a small fraction of the mass of the radio outburst is in the form of non-relativistic plasma. Some of the objects observed belong to the BL-Lacertal class. It is shown that this class is very inhomogeneous in its radio properties. For the violently variable BL-Lacertal type objects the spectrum, flux variations and polarization data strongly suggest that these are very young objects

  4. Valuing commercial radio licences

    NARCIS (Netherlands)

    Kerste, M.; Poort, J.; van Eijk, N.

    2011-01-01

    Within the EU Regulatory Framework, licensees for commercial radio broadcasting may be charged a fee to ensure optimal allocation of scarce resources but not to maximize public revenues. In this paper, it is described how such a fee can be determined for the purpose of licence renewal or extension.

  5. Radio Frequency Identification

    Indian Academy of Sciences (India)

    Radio Frequency Identification (RFID) has been around sinceearly 2000. Its use has currently become commonplace as thecost of RFID tags has rapidly decreased. RFID tags have alsobecome more 'intelligent' with the incorporation of processorsand sensors in them. They are widely used now in manyinnovative ways.

  6. Nanolensed Fast Radio Bursts

    Science.gov (United States)

    Eichler, David

    2017-12-01

    It is suggested that fast radio bursts can probe gravitational lensing by clumpy dark matter objects that range in mass from 10-3 M ⊙-102 M ⊙. They may provide a more sensitive probe than observations of lensings of objects in the Magellanic Clouds, and could find or rule out clumpy dark matter with an extended mass spectrum.

  7. AMATEUR "HAM" RADIO

    Science.gov (United States)

    these cooler months. Did you know your body can cool 25 times faster in water than in air? That water code at 13 or 20 words-per-minute will no longer be required to obtain amateur radio operating be found by contacting the ARRL or using an Internet search engine to search on such topics as "

  8. Parámetros de Transferencia de Materia en el Secado de Frutas Mass Transfer Parameters in Fruit Drying

    OpenAIRE

    Sebastião R Ferreira; Antônio R. S Costa

    2009-01-01

    Se desarrolló un modelo analítico para obtención de parámetros de transferencia de materia en el secado de frutas. El modelo considera la disminución del radio de las frutas durante el proceso de secado. Con el modelo matemático se predice simultánemente el coeficiente externo de transferencia de materia k m y la difusividad de agua en los frutos D AB. Para probar el modelo se obtuvo en forma expermental datos de masa de agua M A en la fruta versus el tiempo de secado t, además del radio inic...

  9. Measurements of fission cross-sections and of neutron production rates; Mesures de sections efficaces de fission et du nombre de neutrons prompts emis par fission

    Energy Technology Data Exchange (ETDEWEB)

    Billaud, P; Clair, C; Gaudin, M; Genin, R; Joly, R; Leroy, J L; Michaudon, A; Ouvry, J; Signarbieux, C; Vendryes, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    } sert de moniteur. b) Mesure de la section efficace de fission de l'uranium-235. Nous comptons effectuer sous peu une mesure de la variation de la section efficace de fission de l'uranium-235 pour des neutrons d'energie superieure a 5 eV et jusqu'a 1 keV, par la methode du temps de vol. La source de neutrons est la cible en uranium d'un accelerateur lineaire pulse d'electrons de 28 MeV. Le detecteur est une chambre a fission a plateaux paralleles de grande dimension contenant au total environ 10 g d'uranium-235 (20 depots de 25 cm de diametre). Les mesures de fission sont corrigees pour tenir compte de la forme du spectre des neutrons, mesure a l'aide d'un assemblage de compteurs a BF{sub 3}. c) Etude sur le nombre moyen de neutrons emis par fission. Nous avons mesure la valeur du nombre moyen {nu} de neutrons emis par fission, de divers isotopes fissiles, induite par des neutrons de 14 MeV. Les neutrons de 14 MeV sont produits par reaction D(t, n) {alpha} a l'aide d'un generateur Cockroft-Walton de 300 kV. (auteur)

  10. Direct Measurement of Tritium in Biological Materials with the Liquid Scintillation Counter; Determination quantitative directe du tritium dans les substances biologiques, au moyen de compteurs a scintillations a liquides; Neposredstvennoe izmerenie kolichestva tritiya v biologicheskikh materialakh pri pomoshchi zhidkogo stsintillyatsionnogo schetchika; Determinacion cuantitativa directa del tritio en sustancias biologicas mediante contadores de centelleador liquido

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, K [Institutt for Atomenergi, Kjeller, Lillestroem (Norway)

    1962-01-15

    Procedures for measurement of tritium in animal tissues and isolated tissue fractions have been reported in the literature. In all the work reported, however, a liquid scintillation coincidence spectrometer has been used for the counting of the samples. In this work a single phototube liquid scintillation counter was used for the measurements. Investigation centred primarily on the direct dissolution of animal tissue in Hyamine 10-X and the suspension counting of lyophilized tissue in scintillating gels. Different tissues, such as liver, intestine, blood and skin, can be dissolved directly in Hyamine and measured with an efficiency of 10-15%. The techniques of quenching correction and certain phosphorescence phenomena as they affect the counting in a single phototube counting system are discussed. The sensitivity of the method, although somewhat less than that of the coincidence-counting arrangement, seems to be sufficient for many applications. The work reported was carried out on tissue samples from mice previously injected with tritium- labelled thymidine. When a dose of approximately 1 {mu}c tritiated thymidine per g of body weight was injected into the mice, the metabolic fate of the thymidine incorporated into deoxyribonucleic acid (DNA) of the various tissues could be followed for a period of one month. (author) [French] Diverses techniques de determination du tritium dans les tissus animaux et fractions isolees de tissus animaux ont deja ete decrites. Mais toutes comportent l'emploi d'un spectrometre de coincidences a scintillations a liquides pour le comptage des echantillons. Pour faire cette determination, l'auteur s'est servi d'un seul phototube-compteur a scintillations a liquides. Il a etudie surtout la dissolution directe de tissu animal dans de l'hyamine 10-X, et le comptage de tissus lyophilises en suspension dans des gels a scintillations. Certains tissus, tels que le foie, l'intestin, le sang et la peau, peuvent Etre dissous directement dans l

  11. ¡París!

    Directory of Open Access Journals (Sweden)

    Beatriz Caballero

    2003-01-01

    Full Text Available El día no le alcanzaba para caminarlo. Conocía cada puente, cada calle,plaza, museo, rincón, iglesia, café, y la mesa con el mejor ángulo para mirar siempre una iglesia, ojalá Saint-Germain-des-Pres, o Notre-Dame. Siempre contaba la impresión que le había causado a Bolívar ver allí cuando el papa coronó a Napoleón. Él se iba para la oficina todos los días, Luis a un taller a pintar, Antonio a estudiar ciencias políticas, yo al colegio y mamá hacía las cosas prácticas. Aprendíamos francés todos al tiempo y por la noche nos contábamos lo nuevo que cada uno había aprendido. Mamá después, cuando ya se quería volver, decía que París nos había maleado a todos. Estaba en pleno furor el cine francés de la "nueva ola", pero ella sólo me llevaba a ver películas de vaqueros pues no se fiaba de la clasificación de los periódicos.

  12. Radio images of the planets

    International Nuclear Information System (INIS)

    De Pater, I.

    1990-01-01

    Observations at radio wavelengths make possible detailed studies of planetary atmospheres, magnetospheres, and surface layers. The paper addresses the question of what can be learned from interferometric radio images of planets. Results from single-element radio observations are also discussed. Observations of both the terrestrial and the giant planets are considered. 106 refs

  13. The importance of Radio Quiet Zone (RQZ) for radio astronomy

    Science.gov (United States)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin

    2013-05-01

    Most of radio observatories are located in isolated areas. Since radio sources from the universe is very weak, astronomer need to avoid radio frequency interference (RFI) from active spectrum users and radio noise produced by human made (telecommunication, mobile phone, microwave user and many more. There are many observatories around the world are surrounded by a Radio Quiet Zone (RQZ), which is it was set up using public or state laws. A Radio Quiet Zone normally consists of two areas: an exclusive area in which totally radio emissions are forbidden, with restrictions for residents and business developments, and a larger (radius up to 100 km above) coordination area where the power of radio transmission limits to threshold levels. Geographical Information System (GIS) can be used as a powerful tool in mapping large areas with varying RQZ profiles. In this paper, we report the initial testing of the usage of this system in order to identify the areas were suitable for Radio Quiet Zone. Among the important parameters used to develop the database for our GIS are population density, information on TV and telecommunication (mobile phones) transmitters, road networks (highway), and contour shielding. We will also use other information gathered from on-site RFI level measurements on selected 'best' areas generated by the GIS. The intention is to find the best site for the purpose of establishing first radio quiet zones for radio telescope in Malaysia.

  14. Introduction to international radio regulations

    Energy Technology Data Exchange (ETDEWEB)

    Radicella, S M [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)

    2003-12-15

    These lecture notes contain an overview of basic problems of the International Radio Regulations. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on radio, especially in poor, remote and sparsely populated regions with under-developed telecommunication infrastructure. How the spectrum of radio frequencies is regulated has profound impact on the society, its security, prosperity, and culture. The radio regulations represent a very important framework for an adequate use of radio and should be known by all of those working in the field.

  15. Introduction to international radio regulations

    International Nuclear Information System (INIS)

    Radicella, S.M.

    2003-01-01

    These lecture notes contain an overview of basic problems of the International Radio Regulations. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on radio, especially in poor, remote and sparsely populated regions with under-developed telecommunication infrastructure. How the spectrum of radio frequencies is regulated has profound impact on the society, its security, prosperity, and culture. The radio regulations represent a very important framework for an adequate use of radio and should be known by all of those working in the field

  16. Radio-capacity of ecosystems

    International Nuclear Information System (INIS)

    Kultakhmedov, Yu.; Kultakhmedova-Vyshnyakova, V.

    1997-01-01

    This paper consider a universal approach to ecosystems of different types, based on representation of their radio-capacity. The concept of ecosystem includes reproduction of components (bio-productivity) and conditions such as maintaining of environment quality. Radio-capacity in the case of radionuclide pollution appears in accumulation and redistribution of radionuclides in the ecosystem. As a result the radionuclides are redistributed and buried in soil or lake bottom sediments. Estimation models for the radio-capacity of water and terrestrial ecosystems are represented. The calculations of the radio-capacity factor of water ecosystems are performed, and the high radio-capacity of a freshwater reservoir (F=0.6-0.8) and extremely high radio-capacity of a reservoir cascade (F c =0.99) is shown material from the Dnieper's cascade reservoirs. The methods of radio-capacity estimation of agroecosystems, wood and marine ecosystems are developed. (authors)

  17. The Concept of 'Radio Music'

    DEFF Research Database (Denmark)

    Fjeldsøe, Michael

    2016-01-01

    , educational and didactic effort which would enlighten all of society. For a while it seemed that radio music was considered a genre of its own. To fulfil its function, radio music had to consider technical limitations as well as the educational level and listening modes of the new mass audience. Public radio......, as discussed by Kurt Weill and Paul Hindemith, was at first greeted with great expectations, but soon a more realistic attitude prevailed. Weill, himself a radio critic as well, composed Der Lindberghflug (1929) as a piece of ‘radio music theatre’, but then changed some of its features in order to turn...... it into a didactical play for amateurs, a so-called Lehrstück. The article will present the concept of ‘radio music’ developed within German Neue Sachlichkeit and discuss the relevance of such a concept for current research in the field of radio and music....

  18. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2009-01-01

    The recent years have seen breathtaking progress in technology, especially in the receiver and digital technologies relevant for radio astronomy, which has at the same time advanced to shorter wavelengths. This is the updated and completely revised 5th edition of the most used introductory text in radio astronomy. It presents a unified treatment of the entire field from centimeter to sub-millimeter wavelengths. Topics covered include instruments, sensitivity considerations, observational methods and interpretations of the data recorded with both single dishes and interferometers. This text is useful to both students and experienced practicing astronomers. Besides making major updates and additions throughout the book, the authors have re-organized a number of chapters to more clearly separate basic theory from rapidly evolving practical aspects. Further, problem sets have been added at the end of each chapter.

  19. Radio telescope control

    CERN Document Server

    Schraml, J

    1972-01-01

    An on-line computer control process developed for the 100-m radio telescope of the Max-Planck-Institut fur Radioastronomie in Bonn is described. The instrument is the largest fully steerable antenna in the world. Its operation started on May 31st 1972. It is controlled by a Ferranti Argus 500 on-line computer. The first part of the paper deals with the process itself, the radio telescope and its operation, and the demands resulting for the control program. The second part briefly describes the computer and its hardware. The final part introduces the architecture of the executive program in general, which has been tailored to meet the demands of the process and the hardware. The communication between the observer and the system, the format of data on magnetic tape and an on-line reduction of position measurements are considered. (0 refs).

  20. Die radio in Afrika

    Directory of Open Access Journals (Sweden)

    S. de Villiers

    1966-03-01

    Full Text Available Omvang van radio-uitsendings in en na Afrika. — Redes vir die versnelde tempo van uitbreiding. — Radio as die geskikste massa-kommunikasiemiddel vir Afrika. — Faktore wat die verspreiding bemoeilik. — Skouspelagtige toename in luistertalle.Toe Plinius, wat in die jaar 79 oorlede is, in sy „Historia Naturalis” verklaar het dat daar altyd iets nuuts uit Afrika afkomstig is, kon hy nouliks voorsien het dat die „iets" negentien eeue later in die lug sou setel wat hierdie reuse-vasteland oorspan — ’n Babelse spraakverwarring en ’n ongekende, verbete woorde-oorlog in die etergolwe, onder meer daarop bereken om die harte en hoofde van derduisendes te verower.

  1. NOAA Weather Radio

    Science.gov (United States)

    cosas afectan la recepción de señas de la radio. Por ejemplo, las extensiones grandes de agua de sal receptor con una antena interior de calidad buena, o conectarlo a una antena externa. Generalmente los Programación Español Listado de estación Explicacion de SAME Coverage Station Listing County Listing

  2. Radio Frequency Interference Mitigation

    Science.gov (United States)

    An, T.; Chen, X.; Mohan, P.; Lao, B. Q.

    2017-09-01

    The observational facilities of radio astronomy keep constant upgrades and developments to achieve better capabilities including increasing the time of the data recording and frequency resolutions, and increasing the receiving and recording bandwidth. However in contrast, only a limited spectrum resource has been allocated to radio astronomy by the International Telecommunication Union, resulting in that the radio observational instrumentations are inevitably exposed to undesirable radio frequency interference (RFI) signals which originate mainly from the terrestrial human activity and are becoming stronger with time. RFIs degrade the quality of data and even lead to invalid data. The impact of RFIs on scientific outcome becomes more and more serious. In this article, the requirement for RFI mitigation is motivated, and the RFI characteristics, mitigation techniques, and strategies are reviewed. The mitigation strategies adopted at some representative observatories, telescopes, and arrays are also introduced. The advantages and shortcomings of the four classes of RFI mitigation strategies are discussed and presented, applicable at the connected causal stages: preventive, pre-detection, pre-correlation, and post-correlation. The proper identification and flagging of RFI is the key to the reduction of data loss and improvement in data quality, and is also the ultimate goal of developing RFI mitigation technique. This can be achieved through a strategy involving a combination of the discussed techniques in stages. The recent advances in the high speed digital signal processing and high performance computing allow for performing RFI excision of the large data volumes generated from large telescopes or arrays in both real time and offline modes, aiding the proposed strategy.

  3. C9.A/14 steelwork joints de poutres par plaque frontale : assemblages par gousset

    CERN Document Server

    2015-01-01

    Les Tables de résistances ultimes des assemblages boulonnés par plaque frontale et par gousset, complétées par une description des modèles de calcul et des exemples d’application, ont pour but de faciliter la tâche de l'ingénieur et du constructeur. Cette première partie C9.A/14 contient les chapitres suivants: - Joints de poutres par plaque frontale en acier S235 et S355 - Assemblages par gousset en acier S235 et S355 Les Tables contiennent des données relatives à la géométrie ainsi que les valeurs de calcul correspondantes des résistances ultimes des assemblages ; elles remplacent le chapitre « Assemblages par plaques frontales et boulons HR » des anciennes Tables C9.1 de 1983 / 2002. Le calcul de ces assemblages par plaque frontale est basé sur les hypothèses du modèle de la méthode des composants décrite dans la norme SN EN 1993-1-8. Les vérifications sont effectuées selon la norme SIA 263:2013. Les assemblages par gousset remplacent les assemblages par double cornière, (telle...

  4. AIDS radio triggers.

    Science.gov (United States)

    Elias, A M

    1991-07-01

    In April 1991, the Ethnic Communities' Council of NSW was granted funding under the Community AIDS Prevention and Education Program through the Department of Community Services and Health, to produce a series of 6x50 second AIDS radio triggers with a 10-second tag line for further information. The triggers are designed to disseminate culturally-sensitive information about HIV/AIDS in English, Italian, Greek, Spanish, Khmer, Turkish, Macedonian, Serbo-Croatian, Arabic, Cantonese, and Vietnamese, with the goal of increasing awareness and decreasing the degree of misinformation about HIV/AIDS among people of non-English-speaking backgrounds through radio and sound. The 6 triggers cover the denial that AIDS exists in the community, beliefs that words and feelings do not protect one from catching HIV, encouraging friends to be compassionate, compassion within the family, AIDS information for a young audience, and the provision of accurate and honest information on HIV/AIDS. The triggers are slated to be completed by the end of July 1991 and will be broadcast on all possible community, ethnic, and commercial radio networks across Australia. They will be available upon request in composite form with an information kit for use by health care professionals and community workers.

  5. 3.55 GeV/c Kp elastic scattering near 180 deg; Diffusion elastique des K de 3.55 GeV/C par les protons, au voisinage de 180 deg

    Energy Technology Data Exchange (ETDEWEB)

    Duflo, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    Backward elastic K{sup +}p and K{sup -}p scattering has been measured in the angular interval 168 deg. < {theta}.c.m. < 177 deg. The experimental apparatus included optical spark chambers to measure the three prongs of the event scattering, a set of scintillation counters and Cerenkov counters to select events ant trigger chambers, and a magnet to determine the moment of the recoil proton. 106000 photographs was taken. Of these, 22 satisfied all requirements as elastic K{sup +}p scattering events. No event was found satisfy the kinematical criteria for K{sup -}p elastic scattering. The correspondent values of differential cross sections are: (d{sigma}/d{omega})K{sup +}p {yields} pK{sup +} = 17 {+-} 4 {mu}b/ster. (d{sigma}/d{omega})K{sup -}p {yields} pK{sup -} {<=} 0.6 {mu}b/ster. Contaminations by {pi}p backward scattering, and inelastic scattering were estimated. Elastic scattering K{sup +}p exhibits a backward peak. A reasonably satisfactory interpretation of our results is obtained by exchange models. There is, in fact, no definitely established particles which could intermediate the Kp{sup -} {yields} pK{sup -} process in exchange cannel. That is in good agreement with our small value of K{sup -}p backward elastic scattering cross section. Our results lend support to the conclusions of the interference model developed by Barger and Cline for the {pi}p backward scattering, and to qualitative previsions of the Quark models. (author) [French] La diffusion elastique en arriere des K{sup +} et K{sup -} par les protons a ete mesuree dans l'intervalle angulaire 168 deg. < {theta}cm < 177 deg. Le dispositif experimental comprenait des chambres a etincelles 'optiques' pour mesurer les trois trajectoires de l'evenement diffuse, un ensemble de compteurs a scintillations et de compteurs Cerenkov pour selectionner les evenements et declencher les chambres, et un aimant pour determiner le moment du proton de recul. 106000 photographies ont ete prises

  6. 3.55 GeV/c Kp elastic scattering near 180 deg; Diffusion elastique des K de 3.55 GeV/C par les protons, au voisinage de 180 deg

    Energy Technology Data Exchange (ETDEWEB)

    Duflo, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    Backward elastic K{sup +}p and K{sup -}p scattering has been measured in the angular interval 168 deg. < {theta}.c.m. < 177 deg. The experimental apparatus included optical spark chambers to measure the three prongs of the event scattering, a set of scintillation counters and Cerenkov counters to select events ant trigger chambers, and a magnet to determine the moment of the recoil proton. 106000 photographs was taken. Of these, 22 satisfied all requirements as elastic K{sup +}p scattering events. No event was found satisfy the kinematical criteria for K{sup -}p elastic scattering. The correspondent values of differential cross sections are: (d{sigma}/d{omega})K{sup +}p {yields} pK{sup +} = 17 {+-} 4 {mu}b/ster. (d{sigma}/d{omega})K{sup -}p {yields} pK{sup -} {<=} 0.6 {mu}b/ster. Contaminations by {pi}p backward scattering, and inelastic scattering were estimated. Elastic scattering K{sup +}p exhibits a backward peak. A reasonably satisfactory interpretation of our results is obtained by exchange models. There is, in fact, no definitely established particles which could intermediate the Kp{sup -} {yields} pK{sup -} process in exchange cannel. That is in good agreement with our small value of K{sup -}p backward elastic scattering cross section. Our results lend support to the conclusions of the interference model developed by Barger and Cline for the {pi}p backward scattering, and to qualitative previsions of the Quark models. (author) [French] La diffusion elastique en arriere des K{sup +} et K{sup -} par les protons a ete mesuree dans l'intervalle angulaire 168 deg. < {theta}cm < 177 deg. Le dispositif experimental comprenait des chambres a etincelles 'optiques' pour mesurer les trois trajectoires de l'evenement diffuse, un ensemble de compteurs a scintillations et de compteurs Cerenkov pour selectionner les evenements et declencher les chambres, et un aimant pour determiner le moment du proton de recul. 106000 photographies ont ete prises, dont 22 ont satisfait a

  7. Demountable 4 {pi} Geiger Counters for Standardization and the Assay of Low-Activity Samples; Compteurs 4 {pi} GM demontables pour l'etalonnage et l'essai d'echantillons de faible activite; S'emnye schetchiki Gejgera na 4 {pi} dlya standartizatsii i otsenki prob nizkoj aktivnosti; Condatores GM 4 {pi} para la normalizacion de patrones radiactivos con baja actividad

    Energy Technology Data Exchange (ETDEWEB)

    Trott, N G; Bentley, R E; Burton, L K [Physics Department, Institute of Cancer Research, Royal Cancer Hospital, London, S. W. 3 (United Kingdom)

    1960-06-15

    Some developments in the design of 4 {pi} GM counters are reported and applications of these counters in the measurements of radioactive standards, in relation to radiological work, are discussed. In the two types of 4 {pi} GM counter described the anode wires can be easily removed thereby facilitating cleaning. One type has been used successfully for several years in the standardization of {beta}-emitting radioactive nuclides and some results of intercomparison s of standards with other laboratories are presented. These counters have also been applied, in conjunction with a {gamma} ionization system, in determinations of the specific {gamma}-ray emission (k-factor) for Fe{sup 59}, Cs{sup 137} and Ir{sup 192}. The second type is a smaller low-background version of the above counter, constructed in stainless steel and designed primarily for the assay of small amounts of radioactivity in biological materials. It can also be adapted for the absolute measurement of radioactive sources at low counting rates {<=} 100 counts per minute) since, when shielded with cosmic-ray counters in anti-coincidence, a stable background of between 1 and 2 counts per minute can be obtained. (author) [French] Les auteurs decrivent certains perfectionnement s dans la construction de compteurs 4 {pi} GM et discutent les utilisations de ces compteurs pour la mesure d'etalons radioactifs, en relation avec les recherches radiologiques. Les filaments anodiques des deux types de compteurs 4 {pi} GM decrits peuvent etre facilement enleves, ce qui facilite le nettoyage. L'un des types a ete utilise avec succes durant plusieures annees pour l'etalonnage de nuclides {beta} actifs; les auteurs presentent les resultats des comparaisons d'etalons faites avec d'autres laboratoires. Ce type de compteur a ete egalement utilise pour la determination du facteur k (emission {gamma} specifique) de Fe{sup 59}, Cs{sup 137} et Ir{sup 182}. Le second type de compteurs est une version reduite, a faible mouvement

  8. Protease-activated receptor (PAR)-2 is required for PAR-1 signalling in pulmonary fibrosis

    NARCIS (Netherlands)

    Lin, Cong; von der Thüsen, Jan; Daalhuisen, Joost; ten Brink, Marieke; Crestani, Bruno; van der Poll, Tom; Borensztajn, Keren; Spek, C. Arnold

    2015-01-01

    Idiopathic pulmonary fibrosis is the most devastating diffuse fibrosing lung disease of unknown aetiology. Compelling evidence suggests that both protease-activated receptor (PAR)-1 and PAR-2 participate in the development of pulmonary fibrosis. Previous studies have shown that bleomycin-induced

  9. Flexible Adaptation in Cognitive Radios

    CERN Document Server

    Li, Shujun

    2013-01-01

    This book provides an introduction to software-defined radio and cognitive radio, along with methodologies for applying knowledge representation, semantic web, logic reasoning and artificial intelligence to cognitive radio, enabling autonomous adaptation and flexible signaling. Readers from the wireless communications and software-defined radio communities will use this book as a reference to extend software-defined radio to cognitive radio, using the semantic technology described. Readers with a background in semantic web and artificial intelligence will find in this book the application of semantic web and artificial intelligence technologies to wireless communications. For readers in networks and network management, this book presents a new approach to enable interoperability, collaborative optimization and flexible adaptation of network components. Provides a comprehensive ontology covering the core concepts of wireless communications using a formal language; Presents the technical realization of using a ...

  10. The properties of radio ellipticals

    International Nuclear Information System (INIS)

    Sparks, W.B.; Disney, M.J.; Rodgers, A.W.

    1984-01-01

    Optical and additional radio data are presented for the bright galaxies of the Disney and Wall survey (1977 Mon. Not. R. Astron. Soc. 179, 235). These data form the basis of a statistical comparison of the properties of radio elliptical galaxies to radio-quiet ellipticals. The correlations may be explained by the depth of the gravitational potential well in which the galaxy resides governing the circumstances under which an elliptical galaxy rids itself of internally produced gas. (author)

  11. Central radio sources

    International Nuclear Information System (INIS)

    Phinney, E.S.

    1985-01-01

    The compact radio sources in the nuclei of most active galaxies lie closer to their centers of activity than any other region accessible to observation, excepting only the broad emission line region. They provide uniquely strong evidence for bulk motion of matter at relativistic velocities, encouraging the belief that the activity originates in a gravitational potential well whose escape velocity is of the order of the speed of light. The observational facts are reviewed as well as several theoretical pictures of them. Those places where systematic observations could help to distinguish the true theoretical picture from the many competing forgeries are emphasized. 76 references

  12. Radio Frequency Anechoic Chamber Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the design, manufacture, and test of antenna systems. The facility is also used as an electromagnetic compatibility/radio frequency interference...

  13. The Hartebeeshoek Radio Astronomy Observatory

    International Nuclear Information System (INIS)

    Nicolson, G.D.

    1986-01-01

    This article briefly discusses the questions, problems and study fields of the modern astronomer. Radioastronomy has made important contributions to the study of the evolution of stars and has given much information on the birth of stars while at the other extreme, studies of neutron stars and the radio emission from the remnants of supernova explosions have given further insight into the death of individual stars. Radio astronomical studies have learned astronomers much about the structure of the Milky way and some twenty years ago, in a search for new radio galaxies, quasars were discovered. Radioastronomy research in South Africa is carried out at the Hartebeesthoek Radio Astronomy Observatory

  14. Dramatugi Penyiar Radio

    Directory of Open Access Journals (Sweden)

    Hastika Yanti Nora

    2009-07-01

    Full Text Available Dramaturgy is the work of Erving Goffman. He wrote "Presentation of Self in Everyday Life" in '1959. Following the theatrical analogy, Goffman spoke of a front stage and back stage. The front stage is that part of the performance that generally functions in rather fixed and general ways to define the situation for those who observed the performance. The back stage is situation where facts suppressed in the front or various kinds of informal actions may appear. A back stage is usually adjacent to the front stage, but it also cut off from it. Everyone in this world have to run his role in their everyday life. It also a radio announcer. As an actor, they have to be a nice and friendy person when they perform to make air personality, that is  a good  impression, from their audience. But before their perform in the front stage, there so much to do to prepare in the backstage. The front and back stage is radio announcer dramaturgy.

  15. Design of 118 MHz twelfth harmonic cavity of APS PAR

    International Nuclear Information System (INIS)

    Kang, Y.W.; Kustom, R.L.; Bridges, J.F.

    1992-01-01

    Two radio frequency (RF) cavities are needed in the Positron Accumulator Ring (PAR) of the Advanced Photon Source. One is for the first harmonic frequency at 9.8 MHz, and the other is for the twelfth harmonic frequency at 118 MHz. This note reports on the design of the 118 MHz RF cavity. Computer models are used to find the mode frequencies, impedances, Q-factors, and field distributions in the cavity. The computer codes MAFIA, URMEL, and URMEL-T are useful tools which model and simulate the resonance characteristics of a cavity. These codes employ the finite difference method to solve Maxwell's equations. MAFIA is a three-dimensional problem solver and uses square patches to approximate the inner surface of a cavity. URMEL and URMEL-T are two-dimensional problem solvers and use rectangular and triangular meshes, respectively. URMEL-T and MAFIA can handle problems with arbitrary dielectric materials located inside the boundary. The cavity employs a circularly cylindrical ceramic window to limit the vacuum to the beam pipe. The ceramic window used in the modeling will have a wall thickness of 0.9 cm. This wall thickness is not negligible in determining the resonant frequencies of the cavity. In the following, results of two- and three-dimensional modeling of the cavities using the URMEL-T and MAFIA codes are reported

  16. Tuning in to pavement radio

    NARCIS (Netherlands)

    Ellis, S.

    1989-01-01

    This article describes a phenomenon known all over Africa, for which there is no really satisfactory term in English but which is summed up in the French term 'radio trottoir', literally 'pavement radio'. It may be defined as the popular and unofficial discussion of current affairs in Africa,

  17. Wide Field Radio Transient Surveys

    Science.gov (United States)

    Bower, Geoffrey

    2011-04-01

    The time domain of the radio wavelength sky has been only sparsely explored. Nevertheless, serendipitous discovery and results from limited surveys indicate that there is much to be found on timescales from nanoseconds to years and at wavelengths from meters to millimeters. These observations have revealed unexpected phenomena such as rotating radio transients and coherent pulses from brown dwarfs. Additionally, archival studies have revealed an unknown class of radio transients without radio, optical, or high-energy hosts. The new generation of centimeter-wave radio telescopes such as the Allen Telescope Array (ATA) will exploit wide fields of view and flexible digital signal processing to systematically explore radio transient parameter space, as well as lay the scientific and technical foundation for the Square Kilometer Array. Known unknowns that will be the target of future transient surveys include orphan gamma-ray burst afterglows, radio supernovae, tidally-disrupted stars, flare stars, and magnetars. While probing the variable sky, these surveys will also provide unprecedented information on the static radio sky. I will present results from three large ATA surveys (the Fly's Eye survey, the ATA Twenty CM Survey (ATATS), and the Pi GHz Survey (PiGSS)) and several small ATA transient searches. Finally, I will discuss the landscape and opportunities for future instruments at centimeter wavelengths.

  18. CONSTRAINING RADIO EMISSION FROM MAGNETARS

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, P.; Kaspi, V. M.; Dib, R. [Department of Physics, Rutherford Physics Building, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Champion, D. J. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Hessels, J. W. T., E-mail: plazar@physics.mcgill.ca [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands)

    2012-01-10

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U 0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected for any of our targets. The non-detections allow us to place luminosity upper limits of L{sub 1950} {approx}< 1.60 mJy kpc{sup 2} for periodic emission and L{sub 1950,single} {approx}< 7.6 Jy kpc{sup 2} for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.

  19. Radio observations of symbiotic stars

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A E [Commonwealth Scientific and Industrial Research Organization, Epping (Australia). Div. of Radiophysics; Allen, D A

    1978-09-01

    A search for 2-cm continuum emission from 91 symbiotic stars has been undertaken using the Parkes radio telescope. Nine sources have been detected, four of which are reported for the first time. The radio spectral indices are mostly about + 0.6; these are interpreted in terms of mass loss. In two stars a portion of the radio spectrum has an index of zero, and for one of these stars (RX Puppis) this is plausibly a manifestation of the cessation of symbiotic activity that occurred about two decades ago. There is an extraordinarily good correlation between the detectability at 2cm and the presence of circumstellar dust, but not between the radio and optical domains. The importance of continued radio monitoring of HM Sagittae over the next few years is stressed.

  20. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation

    Science.gov (United States)

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta

    2016-01-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces. To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  1. Radio opaque gloves

    International Nuclear Information System (INIS)

    Whittaker, A.V.; Whittaker, R.E. Jr.; Goldstrom, R.A.; Shipko, F.J.

    1975-01-01

    Radiation shielding garments and accessories, such as radio-opaque gloves for surgeons, shielding against the harmful x-ray radiation in a fluoroscopic zone, are advantageously different from garments for shielding from other medical uses of x-rays. Such garments are provided with zones of differing opacity, whereby desired sensitivity and ''feel'' through the glove material is retained. One feature is the provision of an ''opacity gradient'' across the glove cross section with opacity being relatively low at the fingertip area (lesser shield-thickness), but relatively high at the less nonprehensile hand zones, such as the palm. Glove fabrication techniques for achieving such an opacity gradient are described. (U.S.)

  2. MUSIC RADIO-JOURNALISM

    Directory of Open Access Journals (Sweden)

    Dubovtceva Ludmila I.

    2014-04-01

    Full Text Available The article is based on years of practical experience, the author highlights the main radio genres in which music correspondent, music reviewer, music commentator, and music leading and a disc jockey work. Theoretical principles of their creative activities are analyzed in common journalistic genres, such as interview, reportage, talk show, live broadcast, radiofilm, as well as specialized genres like concert on demand and music competition. Journalist’ speech is seen as a logical element, the incoming with music in art-structural relationships. However, it does not become the predominant sound layer and aims to harmonious correlation or local penetration into music opus. In addition, important links in music journalism are defined the auxiliary "offscreen" editor's job and keeping the original sound archive. The author cites a number of own work examples on the air.

  3. Radio-adaptive response

    International Nuclear Information System (INIS)

    Ikushima, T.

    1992-01-01

    Knowledge about cellular events in mammalian cells exposed to low doses of ionizing radiation is meager. Recent works showed that human lymphocytes become resistant to radiation-induced chromosomal damage after exposure to low doses of ionizing radiation. Experimental evidence for radio-adaptive response (RAR) in cultured mammalian cells was obtained. Exposure to very low doses of gamma-rays or tritium beta-rays make cells less susceptible to the induction of micronuclei and sister chromatid exchanges by subsequent higher doses. Many important characteristics of the novel response suggest that RAR is a stress response resulting in the enhanced repair of chromosomal DNA damage in cell under restricted conditions. Experiments are still in progress in order to elucidate the molecular basis for RAR processes. (author). 13 refs.; 2 figs., 1 tab

  4. Implementing Software Defined Radio

    CERN Document Server

    Grayver, Eugene

    2013-01-01

    Software Defined Radio makes wireless communications easier, more efficient, and more reliable. This book bridges the gap between academic research and practical implementation. When beginning a project, practicing engineers, technical managers, and graduate students can save countless hours by considering the concepts presented in these pages. The author covers the myriad options and trade-offs available when selecting an appropriate hardware architecture. As demonstrated here, the choice between hardware- and software-centric architecture can mean the difference between meeting an aggressive schedule and bogging down in endless design iterations. Because of the author’s experience overseeing dozens of failed and successful developments, he is able to present many real-life examples. Some of the key concepts covered are: Choosing the right architecture for the market – laboratory, military, or commercial Hardware platforms – FPGAs, GPPs, specialized and hybrid devices Standardization efforts to ens...

  5. Radio-adaptive response

    International Nuclear Information System (INIS)

    Ikushima, Takaji

    1991-01-01

    An adaptive response to radiation stress was found in cultured Chinese hamster V79 cells, as a suppressed induction of micronuclei (MNs) and sister chromatid exchanges (SCEs) in the cells conditioned by very low doses. The important characteristics of the novel chromosomal response, called radio-adaptive response (RAR), that have newly emerged in this study are: 1) Low doses of beta-rays from tritiated water (HTO) as well as tritiated thymidine can cause the RAR. 2) Thermal neutrons, a high LET radiation, can not act as tritium beta-rays or gamma-rays. 3) The RAR expression is suppressed by an inhibition of protein synthesis. 4) Several proteins are newly synthesized concurrently with the RAR expression after adapting doses, viewed by two-dimensional electrophoresis of cellular proteins. These results suggest that the RAR is an adaptive chromosomal DNA repair induced by very low doses of low LET radiations under restricted conditions, accompanying the inducible specific gene expression. (author)

  6. A turbulent radio jet

    International Nuclear Information System (INIS)

    Kahn, F.D.

    1983-01-01

    A relativistic plasma flow can explain many of the observations on the one-sided jets, which are associated with radio sources that show superluminal motions in their cores. The pressure from the ambient medium will communicate across the jet in a relatively short distance, typically 30 kpc. The friction between the jet and the external medium then makes the flow go turbulent. As a result the jet dissipates energy and will be brought to rest within a few hundred kpc, if it does not strike an obstacle before. The mean flow in the jet is strongly sheared and stretches the lines of force of any magnetic field frozen into the plasma. The dominant field direction, as seen from the rest frame of the plasma, is therefore parallel to the length of the jet. Polarization measurements have shown that this is in fact the case. (author)

  7. AGONIZAN RADIOS MINERAS

    Directory of Open Access Journals (Sweden)

    Raquel Salinas

    2015-01-01

    Full Text Available Se ofrece un amplio análisis sobre la industria electoral, recordando que un candidato a presidente es "un producto para la venta". Se Desmenuzan las estrategias utilizadas en el plebiscito chileno,las elecciones norteamericanas con el NO a BUSH. El Mercadeo Social es una nueva metodología utilizada en proyectos de desarrollo a nivel de campo por ello se hace un esclarecimiento y clarifica el vínculo con la comunicación. Se agrega temas como: Los modelos de recepción de mensajes cuyos marcos conceptuales y metodologías aún no se han adaptado al potencial de esta línea de trabajo.Se analiza la agonía de las radios mineras en Bolivia en la que 42 años de historia y heroísmo se desmoronan.

  8. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  9. Radio frequency picosecond phototube

    International Nuclear Information System (INIS)

    Margaryan, A.; Carlini, R.; Ent, R.; Grigoryan, N.; Gyunashyan, K.; Hashimoto, O.; Hovater, K.; Ispiryan, M.; Knyazyan, S.; Kross, B.; Majewski, S.; Marikyan, G.; Mkrtchyan, M.; Parlakyan, L.; Popov, V.; Tang, L.; Vardanyan, H.; Yan, C.; Zhamkochyan, S.; Zorn, C.

    2006-01-01

    We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation

  10. Radio frequency picosecond phototube

    Energy Technology Data Exchange (ETDEWEB)

    Margaryan, A. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia)]. E-mail: mat@mail.yerphi.am; Carlini, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ent, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Grigoryan, N. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Gyunashyan, K. [Yerevan State University of Architecture and Construction, Yerevan (Armenia); Hashimoto, O. [Tohoku University, Sendai 98-77 (Japan); Hovater, K. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ispiryan, M. [University of Houston, 4800 Calhoun Rd, Houston TX 77204 (United States); Knyazyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Kross, B. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Majewski, S. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Marikyan, G. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Mkrtchyan, M. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Parlakyan, L. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Popov, V. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Tang, L. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Vardanyan, H. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Yan, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Zhamkochyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Zorn, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States)

    2006-10-15

    We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation.

  11. Radio propagation measurement and channel modelling

    CERN Document Server

    Salous, Sana

    2013-01-01

    While there are numerous books describing modern wireless communication systems that contain overviews of radio propagation and radio channel modelling, there are none that contain detailed information on the design, implementation and calibration of radio channel measurement equipment, the planning of experiments and the in depth analysis of measured data. The book would begin with an explanation of the fundamentals of radio wave propagation and progress through a series of topics, including the measurement of radio channel characteristics, radio channel sounders, measurement strategies

  12. Magnetospheric radio sounding

    International Nuclear Information System (INIS)

    Ondoh, Tadanori; Nakamura, Yoshikatsu; Koseki, Teruo; Watanabe, Sigeaki; Murakami, Toshimitsu

    1977-01-01

    Radio sounding of the plasmapause from a geostationary satellite has been investigated to observe time variations of the plasmapause structure and effects of the plasma convection. In the equatorial plane, the plasmapause is located, on the average, at 4 R sub(E) (R sub(E); Earth radius), and the plasma density drops outwards from 10 2 -10 3 /cm 3 to 1-10/cm 3 in the plasmapause width of about 600 km. Plasmagrams showing a relation between the virtual range and sounding frequencies are computed by ray tracing of LF-VLF waves transmitted from a geostationary satellite, using model distributions of the electron density in the vicinity of the plasmapause. The general features of the plasmagrams are similar to the topside ionograms. The plasmagram has no penetration frequency such as f 0 F 2 , but the virtual range of the plasmagram increases rapidly with frequency above 100 kHz, since the distance between a satellite and wave reflection point increases rapidly with increasing the electron density inside the plasmapause. The plasmapause sounder on a geostationary satellite has been designed by taking account of an average propagation distance of 2 x 2.6 R sub(E) between a satellite (6.6 R sub(E)) and the plasmapause (4.0 R sub(E)), background noise, range resolution, power consumption, and receiver S/N of 10 dB. The 13-bit Barker coded pulses of baud length of 0.5 msec should be transmitted in direction parallel to the orbital plane at frequencies for 10 kHz-2MHz in a pulse interval of 0.5 sec. The transmitter peak power of 70 watts and 700 watts are required respectively in geomagnetically quiet and disturbed (strong nonthermal continuum emissions) conditions for a 400 meter cylindrical dipole of 1.2 cm diameter on the geostationary satellite. This technique will open new area of radio sounding in the magnetosphere. (auth.)

  13. Contamination potentielle des aliments par des ...

    African Journals Online (AJOL)

    SARA Computers

    la notion de la pollution et de l'exposition aux PCBs, lorsque 77% n'ont pas conscience de cette situation de risque ... 2018). Quoique la contamination par les. PCBs soit de faible niveau, elle est ...... Université Paris-Est, Paris, France ; 183.

  14. A Radio Astronomy Science Education Partnership - GAVRT and Radio JOVE

    Science.gov (United States)

    Higgins, C. A.; Thieman, J. R.; Bunnell, K.; Soholt, G.

    2009-12-01

    The planet Jupiter provides an excellent subject to educate, engage, and inspire students and teachers to learn science. The Goldstone Apple-Valley Radio Telescope (GAVRT) program (http://www.lewiscenter.org/gavrt) and The Radio JOVE project (http://radiojove.gsfc.nasa.gov) each have a long history of allowing students and teachers to interact with scientists and real radio telescopes. The upcoming Juno mission to Jupiter (2011 launch) allows both GAVRT and Radio JOVE to combine efforts and engage with the NASA Juno mission, thus increasing the excitement and learning potential for teachers, students, and the general public. Teachers can attend workshops for training to operate a 34-meter radio telescope and/or build their own simple radio telescope, both of which can be used directly in the classroom. We will overview some classroom activities and highlight some teacher-student experiences. In addition, we will update our efforts on greater Web-based control of the radio telescopes, as well as highlight our upcoming workshops to allow better access for teachers in different parts of the Country.

  15. CFD analysis of PAR performance as function of inlet design

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kweonha, E-mail: khpark@kmou.ac.kr [Division of Mechanical and Energy systems Engineering, Korea Maritime University, Dongsam-dong, Yeongdo-gu, Busan 606-791 (Korea, Republic of); Khor, Chong Lee, E-mail: itachi_829@hotmail.com [Department of Mechanical Engineering, Korea Maritime University (Korea, Republic of)

    2016-01-15

    Highlights: • The new concept of PAR (passive autocatalytic recombiner) was proposed and analyzed. • Guidance wall was added at the bottom of PAR to enhance the flow rate through the catalyst. • The new concept of PAR was proved to have a better hydrogen removal performance. - Abstract: Passive autocatalytic recombiner (PAR) is very useful hydrogen mitigation measurement. It is widely implemented in the current and advanced light water reactors (ALWRs). The design of the PARs should be optimized for the specific use under severe accident scenarios. Several techniques and innovations have been fused into the PAR, as an effort to increase its efficiency of hydrogen mitigation. This study proposes different concepts of PAR, which applied some changes to the honeycomb catalyst PAR made by the Korea Nuclear Technology (KNT) Inc. Two slices of plate are added to the bottom of PAR model, which intended to act as a reflection wall and promote the gas flow into PAR. Hydrogen volume fraction was given 4 vol. % which tested by KNT to investigate the performance of PAR in different direction gas flow conditions to see maximum hydrogen recombination rate. The new concept of PAR was proved to have a better hydrogen removal performance compared to the original honeycomb catalyst PAR.

  16. CFD analysis of PAR performance as function of inlet design

    International Nuclear Information System (INIS)

    Park, Kweonha; Khor, Chong Lee

    2016-01-01

    Highlights: • The new concept of PAR (passive autocatalytic recombiner) was proposed and analyzed. • Guidance wall was added at the bottom of PAR to enhance the flow rate through the catalyst. • The new concept of PAR was proved to have a better hydrogen removal performance. - Abstract: Passive autocatalytic recombiner (PAR) is very useful hydrogen mitigation measurement. It is widely implemented in the current and advanced light water reactors (ALWRs). The design of the PARs should be optimized for the specific use under severe accident scenarios. Several techniques and innovations have been fused into the PAR, as an effort to increase its efficiency of hydrogen mitigation. This study proposes different concepts of PAR, which applied some changes to the honeycomb catalyst PAR made by the Korea Nuclear Technology (KNT) Inc. Two slices of plate are added to the bottom of PAR model, which intended to act as a reflection wall and promote the gas flow into PAR. Hydrogen volume fraction was given 4 vol. % which tested by KNT to investigate the performance of PAR in different direction gas flow conditions to see maximum hydrogen recombination rate. The new concept of PAR was proved to have a better hydrogen removal performance compared to the original honeycomb catalyst PAR.

  17. South African Radio League Introduction to Amateur Radio: A study guide for the Radio Amateur Examination

    CSIR Research Space (South Africa)

    Burger, Chris

    2016-01-01

    Full Text Available ) .............................................................................. 15 1.12 The Radio Amateurs’ Examination .......................................................................... 15 1.13 Restrictions on the Use of an Amateur Radio Station .............................................. 16 Chapter 2: Operating... ............................................................................................. 116 14.1 Theory of Operation ............................................................................................... 116 14.2 Turns Ratio...

  18. Radio Astronomy Explorer /RAE/. I - Observations of terrestrial radio noise.

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.; Stone, R. G.

    1973-01-01

    Radio Astronomy Explorer (RAE) I data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial radio noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 dB and more above cosmic noise background, on frequencies above the F-layer critical frequency.

  19. Decontamination tests using an electrolytic method on NS 22 S stainless steel discs (1963); Essais de decontamination par voie electrolytique de plaquettes en acier inoxydable NS 22 S (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Boutot, P; Schipfer, P [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1963-07-01

    These tests were carried out with a view to observing the results obtained by using electrolytic polishing for the decontamination operations. The experimental equipment consists essentially of a current rectifier and adjuster, and of an electrolytic cell fitted with an automatic system for thermal regulation and agitation. The samples made of type NS 22 S stainless steel are contaminated with an active solution of fission products. The activity of the discs is measured before and after each treatment using a bell counter. For each electrolyte, the parameters studied are: - the time, - the reactant concentration, - the temperature, - the current density, - the corrosion. Taking into account the necessity of transforming as little as possible the surface of the part to be treated, the best results are generally obtained using intermediate concentrations of the reactant, low temperatures, and high current densities. (authors) [French] Ces essais ont ete effectues dans le but d'observer les resultats obtenus en utilisant le procede de polissage electrolytique pour les operations de decontamination. Le dispositif experimental consiste essentiellement en un redresseur-variateur de courant et en une cellule electrolytique munie d'un systeme automatique de regulation thermique et d'agitation. Les echantillons en acier inoxydable du type NS 22 S sont contamines par une solution active de produits de fission. L'activite des plaquettes est mesuree avant et apres chaque traitement au moyen d'un compteur cloche. Pour chaque electrolyte, les parametres etudies sont: - le temps, - la concentration du reactif, - la temperature, - la densite de courant, - la corrosion. En tenant compte de la necessite de transformer au minimum l'etat de surface de la piece a traiter, les resultats les meilleurs sont generalement obtenus pour des concentrations moyennes de reactif, des temperatures basses et des densites de courant elevees. (auteurs)

  20. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign (March,...

  1. X rays from radio binaries

    International Nuclear Information System (INIS)

    Apparao, K.M.V.

    1977-01-01

    Reference is made to the radio binary systems CC Cas, AR Lac, β Per (Algol), β Lyr, b Per and Cyg X-1. It is stated that a thermal interpretation of the radiation from Algol requires a much larger x-ray flux than the observed value of 3.8 x 10 -11 erg/cm 2 /sec/keV in the 2 to 6 keV energy range. Observations of some non-thermal flares, together with the small size of the radio source in Algol, indicate that the radio emission is non-thermal in nature. The radio emission is interpreted as synchrotron radiation and it is suggested that the observed x-ray emission is due to inverse Compton scattering of the light of the primary star by the radio electrons. The x-ray emission from other radio binaries is also calculated using this model. The energy for the radio electrons can arise from annihilation of magnetic lines connecting the binary stars, twisted by the rotation of the stars. (U.K.)

  2. 75 FR 10439 - Cognitive Radio Technologies and Software Defined Radios

    Science.gov (United States)

    2010-03-08

    ... petition could not through the exercise of due diligence have learned of the facts in question prior to... to a wide variety of radio services, including safety-of-life services--the Commission holds the...

  3. radio frequency based radio frequency based water level monitor

    African Journals Online (AJOL)

    eobe

    ABSTRACT. This paper elucidates a radio frequency (RF) based transmission and reception system used to remotely monitor and .... range the wireless can cover but in this prototype, it ... power supply to the system, the sensed water level is.

  4. Introduction to solar radio astronomy and radio physics

    International Nuclear Information System (INIS)

    Krueger, A.

    1979-01-01

    A systematic summary is presented of the work done during the last thirty years in the field of solar radio astronomy from the standpoint of general solar physics. Instrumental aspects, observations and theory are covered. A brief introduction is given to the matter consisting of the history of solar radio astronomy and some fundamentals of astronomy and solar physics are outlined. Some topics of the instrumental background of solar radio astronomy and the main results of observations are presented. The elements of a theoretical interpretation of solar radio observations are reported and a synthesis of both observation and theory contributing to a general picture of solar and solar-terrestrial physics is outlined. (C.F./Auth)

  5. Introduction to international radio regulations

    Energy Technology Data Exchange (ETDEWEB)

    Struzak, R

    2003-12-15

    These notes introduce the ITU Radio Regulations and related UN and WTO agreements that specify how terrestrial and satellite radio should be used in all countries over the planet. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on these regulations. The paper also discusses few problems related to the use of the radio frequencies and satellite orbits. The notes are extracted from a book under preparation, in which these issues are discussed in more detail. (author)

  6. Introduction to international radio regulations

    International Nuclear Information System (INIS)

    Struzak, R.

    2003-01-01

    These notes introduce the ITU Radio Regulations and related UN and WTO agreements that specify how terrestrial and satellite radio should be used in all countries over the planet. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on these regulations. The paper also discusses few problems related to the use of the radio frequencies and satellite orbits. The notes are extracted from a book under preparation, in which these issues are discussed in more detail. (author)

  7. Magnetogasdynamics of double radio sources

    International Nuclear Information System (INIS)

    Nepveu, M.

    1979-01-01

    The magnetogasdynamical behaviour of plasmoids moving through an ambient gas is investigated numerically with a two-dimensional code, based on the SHASTA scheme. The astrophysical importance of this study lies in the observed extended extragalactic radio sources. It is assumed that plasma clouds with cylinder symmetry are ejected from the nucleus of a galaxy. Their large-scale evolution in the intergalactic medium (IGM) is followed. The gas dynamics of an ejected cloud, the magnetogasdynamics of ejected clouds, the Christiansen-Pacholczyk-Scott picture for radio galaxies and the shear layers in double radio sources are studied. (Auth.)

  8. Shoestring Budget Radio Astronomy (Abstract)

    Science.gov (United States)

    Hoot, J. E.

    2017-12-01

    (Abstract only) The commercial exploitation of microwave frequencies for cellular, WiFi, Bluetooth, HDTV, and satellite digital media transmission has brought down the cost of the components required to build an effective radio telescope to the point where, for the cost of a good eyepiece, you can construct and operate a radio telescope. This paper sets forth a family of designs for 1421 MHz telescopes. It also proposes a method by which operators of such instruments can aggregate and archive data via the Internet. With 90 or so instruments it will be possible to survey the entire radio sky for transients with a 24 hour cadence.

  9. Plasma suPAR is lowered by smoking cessation

    DEFF Research Database (Denmark)

    Eugen-Olsen, Jesper; Ladelund, Steen; Sørensen, Lars Tue

    2016-01-01

    BACKGROUND: Soluble urokinase plasminogen activator receptor (suPAR) is a stable inflammatory biomarker. In patients, suPAR is a marker of disease presence, severity and prognosis. In the general population, suPAR is predictive of disease development, such as diabetes and cardiovascular disease a...

  10. Copenhagen uPAR prostate cancer (CuPCa) database

    DEFF Research Database (Denmark)

    Lippert, Solvej; Berg, Kasper D; Høyer-Hansen, Gunilla

    2016-01-01

    AIM: Urokinase plasminogen activator receptor (uPAR) plays a central role during cancer invasion by facilitating pericellular proteolysis. We initiated the prospective 'Copenhagen uPAR Prostate Cancer' study to investigate the significance of uPAR levels in prostate cancer (PCa) patients. METHODS...

  11. The inflammatory marker suPAR after cardiac arrest

    DEFF Research Database (Denmark)

    Rundgren, Malin; Lyngbaek, Stig; Fisker, Helle

    2015-01-01

    . This pilot study aimed at investigating suPAR levels in relation to outcome after CA and mild induced hypothermia. METHODS: suPAR levels were measured at 6, 36, and 72 hours in patients treated with hypothermia after CA. suPAR levels were analyzed in relation to survival after 6 months. Receiver operating...

  12. The excess radio background and fast radio transients

    International Nuclear Information System (INIS)

    Kehayias, John; Kephart, Thomas W.; Weiler, Thomas J.

    2015-01-01

    In the last few years ARCADE 2, combined with older experiments, has detected an additional radio background, measured as a temperature and ranging in frequency from 22 MHz to 10 GHz, not accounted for by known radio sources and the cosmic microwave background. One type of source which has not been considered in the radio background is that of fast transients (those with event times much less than the observing time). We present a simple estimate, and a more detailed calculation, for the contribution of radio transients to the diffuse background. As a timely example, we estimate the contribution from the recently-discovered fast radio bursts (FRBs). Although their contribution is likely 6 or 7 orders of magnitude too small (though there are large uncertainties in FRB parameters) to account for the ARCADE 2 excess, our development is general and so can be applied to any fast transient sources, discovered or yet to be discovered. We estimate parameter values necessary for transient sources to noticeably contribute to the radio background

  13. Radio frequency integrated circuit design for cognitive radio systems

    CERN Document Server

    Fahim, Amr

    2015-01-01

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

  14. A radio and optical study of Molonglo radio sources

    Science.gov (United States)

    Ishwara-Chandra, C. H.; Saikia, D. J.; McCarthy, P. J.; van Breugel, W. J. M.

    2001-05-01

    We present multi-wavelength radio observations with the Very Large Array, and narrow- and broad-band optical observations with the 2.5-m telescope at the Las Campanas Observatory, of a well-defined sample of high-luminosity Fanaroff-Riley class II radio galaxies and quasars, selected from the Molonglo Reference Catalogue 1-Jy sample. These observations were carried out as part of a programme to investigate the effects of orientation and environment on some of the observed properties of these sources. We examine the dependence of the Liu-Pooley relationship, which shows that radio lobes with flatter radio spectra are less depolarized, on size, identification and redshift, and show that it is significantly stronger for smaller sources, with the strength of the relationship being similar for both radio galaxies and quasars. In addition to Doppler effects, there appear to be intrinsic differences between the lobes on opposite sides. We discuss the asymmetry in brightness and location of the hotspots, and present estimates of the ages and velocities from matched-resolution observations in the L and C bands. Narrow- and broad-band optical images of some of these sources were made to study their environments and correlate with the symmetry parameters. An extended emission-line region is seen in a quasar, and in four of the objects possible companion galaxies are seen close to the radio axis.

  15. Radio-adaptive response

    International Nuclear Information System (INIS)

    Ikushima, T.

    1992-01-01

    An adaptive response to radiation stress was found as a suppressed induction of chromosomal damage including micronuclei and sister chromatid exchanges in cultured Chinese hamster V79 cells pre-exposed to very low doses of ionizing radiations. The mechanism underlying this novel chromosomal response, called 'radio-adaptive response (RAR)' has been studied progressively. The following results were obtained in recent experiments. 1. Low doses of β-rays from tritiated water (HTO) as well as tritium-thymidine can cause RAR. 2. Thermal neutrons, a high LET radiation, can not act as tritium β-rays or γ-rays. 3. The RAR expression is suppressed not only by the treatment with an inhibitor of protein synthesis but also by RNA synthesis inhibition. 4. Several proteins are newly synthesized concurrently with the RAR expression after the adapting doses, viewed by two-dimensional electrophoresis of cellular proteins. These results suggests that the RAR might be a cellular stress response to a signal produced preferentially by very low doses of low LET radiation under restricted conditions, accompany the inducible specific gene expression. (author)

  16. Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

    Science.gov (United States)

    Baronian, Grégory; Ginda, Katarzyna; Berry, Laurence; Cohen-Gonsaud, Martin; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara; Molle, Virginie

    2015-01-01

    Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

  17. Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

    Directory of Open Access Journals (Sweden)

    Grégory Baronian

    Full Text Available Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

  18. Beamsteerable GNSS Radio Occultation ASIC

    Data.gov (United States)

    National Aeronautics and Space Administration — We will develop an integrated RF ASIC to enable high quality radio occultation (RO) weather observations using the Global Navigations System Satellite (GNSS)...

  19. Sea Turtle Radio Telemetry Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Radio transmitters attached to sea turtles captured in various fishing gear enabled us to track and measure surfacing time of each turtle. Determining location of...

  20. Zero-Power Radio Device.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-01

    This report describes an unpowered radio receiver capable of detecting and responding to weak signals transmit ted from comparatively long distances . This radio receiver offers key advantages over a short range zero - power radio receiver previously described in SAND2004 - 4610, A Zero - Power Radio Receiver . The device described here can be fabricated as an integrated circuit for use in portable wireless devices, as a wake - up circuit, or a s a stand - alone receiver operating in conjunction with identification decoders or other electroni cs. It builds on key sub - components developed at Sandia National Laboratories over many years. It uses surface acoustic wave (SAW) filter technology. It uses custom component design to enable the efficient use of small aperture antennas. This device uses a key component, the pyroelectric demodulator , covered by Sandia owned U.S. Patent 7397301, Pyroelectric Demodulating Detector [1] . This device is also described in Sandia owned U.S. Patent 97266446, Zero Power Receiver [2].

  1. [Ambroise Paré in French literature].

    Science.gov (United States)

    Dumaitre, P

    1995-01-01

    The 16th century by its passionate side has been the favourite one of authors of historical novels in which among the heroes of "cloak and dagger stories" appears sometime Ambroise Paré. Alexandre Dumas (the father) has shown him at the court of Charles IX in La Reine Margot (1845) where he does not however play a great role. On the contrary, Balzac in Le Martyr calviniste (1842) has given him a capital part close to the dying François II, whom he intended to trepanize but had to give up this idea as a consequence of the opposition of the queen-mother Catherine de Médicis. In the present century, Robert Merle in Paris ma bonne ville (Fortune de France, 3, 1980) shows Paré at the time of the Saint Barthélemy.

  2. On the evaluation of Web Radio

    OpenAIRE

    Field, A.N.; Hartel, Pieter H.

    2001-01-01

    We develop an evaluation method for Web radio, and perform it to see what we can be learnt about seven prominent Web radio sites. We also evaluate a commercial FM radio station for control purposes. We present a taxonomy of Web radio, and we give our observations and conclusions on this evaluation.

  3. Radio and line transmission 2

    CERN Document Server

    Roddy, Dermot

    2013-01-01

    Radio and Line Transmission, Volume 2 gives a detailed treatment of the subject as well as an introduction to additional advanced subject matter. Organized into 14 chapters, this book begins by explaining the radio wave propagation, signal frequencies, and bandwidth. Subsequent chapters describe the transmission lines and cables; the aerials; tuned and coupled circuits; bipolar transistor amplifiers; field-effect transistors and circuits; thermionic valve amplifiers; LC oscillators; the diode detectors and modulators; and the superheterodyne receiver. Other chapters explore noise and interfere

  4. Historic Radio Astronomy Working Group

    Science.gov (United States)

    2007-06-01

    This special issue of Astronomische Nachrichten contains the proceedings of a session of the Historic Radio Astronomy Working Group of the International Astronomical Union that took place during the 26th General Assembly of the IAU in Prague on 17th August 2006. In addition to the talks presented in Prague some contributions were solicited to give a more complete overview of `The Early History of European Radio Astronomy'.

  5. Radio astronomy on the moon

    International Nuclear Information System (INIS)

    Burns, J.O.; Asbell, J.

    1987-01-01

    The advantages and opportunities for radio astronomy on the moon during the early to mid 21st century are reviewed. In particular, it is argued that the lack of atmosphere, the extremely low seismic activity, the low RF background, and the natural cryogenic environment make the moon (particularly the far side and the poles) a nearly ideal locale for submillimeter/FIR to VLF (below 10 MHz) radio astronomy. 22 references

  6. RADIO NOISE ADVANCES SEXUAL MATURITY

    African Journals Online (AJOL)

    ansistf-lewis

    Mean age at first egg for the radio birds (143 d) was 13 d significantly earlier than controls, but body weight at ... the first 8 h of a 12-h photoperiod with radio noise, to leave only 4 h of light (4L:20D), supported rates of lay ... Age (AFE) and body weight at, and weight of, first egg were recorded for individual birds, and, after a.

  7. Par Pond refill water quality sampling

    International Nuclear Information System (INIS)

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column

  8. RADIO WITHOUT A LISTENER: "MAYAK"

    Directory of Open Access Journals (Sweden)

    Bysko Maxim V.

    2017-12-01

    Full Text Available The singularity of this article is that it is entirely based on a critical analysis of only one live musical radio program on the Mayak radio station and dedicated to the life and work of the famous British composer Andrew Lloyd Webber. In principle, the article can be considered a scientific review of the media product. Based on his analysis, the author comes to the paradoxical conclusion that the presence of a listener becomes unnecessary for modern broadcasting. This is stated by many principles of the conduct of the air, presented in the radio program, where all the information load is placed on the guest in the studio, where there is no preparatory work of the DJs, where their inability to navigate the genres of journalism violates communication norms and colloquial ethics, where an obvious deconstructive approach to the material offered for the listener. In addition, the phenomenon of being the DJs in the radio studio exclusively "for themselves" is emphasized by the sound design of the radio program, which runs counter to the logic of auditory perception (for example, the sequence of jingles, as well as the incompetent selection of musical material, which undoubtedly repels professional radio listeners-musicians.

  9. Centromere pairing by a plasmid-encoded type I ParB protein

    DEFF Research Database (Denmark)

    Ringgaard, Simon; Löwe, Jan; Gerdes, Kenn

    2007-01-01

    The par2 locus of Escherichia coli plasmid pB171 encodes two trans-acting proteins, ParA and ParB, and two cis-acting sites, parC1 and parC2, to which ParB binds cooperatively. ParA is related to MinD and oscillates in helical structures and thereby positions ParB/parC-carrying plasmids regularly......, hence identifying the N terminus of ParB as a requirement for ParB-mediated centromere pairing. These observations suggest that centromere pairing is an important intermediate step in plasmid partitioning mediated by the common type I loci....

  10. The radio properties of infrared-faint radio sources

    Science.gov (United States)

    Middelberg, E.; Norris, R. P.; Hales, C. A.; Seymour, N.; Johnston-Hollitt, M.; Huynh, M. T.; Lenc, E.; Mao, M. Y.

    2011-02-01

    Context. Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4 GHz, but that are invisible at 3.6 μm when using sensitive Spitzer observations with μJy sensitivities. Their nature is unclear and difficult to investigate since they are only visible in the radio. Aims: High-resolution radio images and comprehensive spectral coverage can yield constraints on the emission mechanisms of IFRS and can give hints to similarities with known objects. Methods: We imaged a sample of 17 IFRS at 4.8 GHz and 8.6 GHz with the Australia Telescope Compact Array to determine the structures on arcsecond scales. We added radio data from other observing projects and from the literature to obtain broad-band radio spectra. Results: We find that the sources in our sample are either resolved out at the higher frequencies or are compact at resolutions of a few arcsec, which implies that they are smaller than a typical galaxy. The spectra of IFRS are remarkably steep, with a median spectral index of -1.4 and a prominent lack of spectral indices larger than -0.7. We also find that, given the IR non-detections, the ratio of 1.4 GHz flux density to 3.6 μm flux density is very high, and this puts them into the same regime as high-redshift radio galaxies. Conclusions: The evidence that IFRS are predominantly high-redshift sources driven by active galactic nuclei (AGN) is strong, even though not all IFRS may be caused by the same phenomenon. Compared to the rare and painstakingly collected high-redshift radio galaxies, IFRS appear to be much more abundant, but less luminous, AGN-driven galaxies at similar cosmological distances.

  11. Information Content in Radio Waves: Student Investigations in Radio Science

    Science.gov (United States)

    Jacobs, K.; Scaduto, T.

    2013-12-01

    We describe an inquiry-based instructional unit on information content in radio waves, created in the summer of 2013 as part of a MIT Haystack Observatory (Westford, MA) NSF Research Experiences for Teachers (RET) program. This topic is current and highly relevant, addressing science and technical aspects from radio astronomy, geodesy, and atmospheric research areas as well as Next Generation Science Standards (NGSS). Projects and activities range from simple classroom demonstrations and group investigations, to long term research projects incorporating data acquisition from both student-built instrumentation as well as online databases. Each of the core lessons is applied to one of the primary research centers at Haystack through an inquiry project that builds on previously developed units through the MIT Haystack RET program. In radio astronomy, students investigate the application of a simple and inexpensive software defined radio chip (RTL-SDR) for use in systems implementing a small and very small radio telescope (SRT and VSRT). Both of these systems allow students to explore fundamental principles of radio waves and interferometry as applied to radio astronomy. In ionospheric research, students track solar storms from the initial coronal mass ejection (using Solar Dynamics Observatory images) to the resulting variability in total electron density concentrations using data from the community standard Madrigal distributed database system maintained by MIT Haystack. Finally, students get to explore very long-baseline interferometry as it is used in geodetic studies by measuring crustal plate displacements over time. Alignment to NextGen standards is provided for each lesson and activity with emphasis on HS-PS4 'Waves and Their Applications in Technologies for Information Transfer'.

  12. Radio Frequency Interference Site Survey for Thai Radio Telescopes

    Science.gov (United States)

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

    2017-09-01

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

  13. IA-Regional-Radio - Social Network for Radio Recommendation

    Science.gov (United States)

    Dziczkowski, Grzegorz; Bougueroua, Lamine; Wegrzyn-Wolska, Katarzyna

    This chapter describes the functions of a system proposed for the music hit recommendation from social network data base. This system carries out the automatic collection, evaluation and rating of music reviewers and the possibility for listeners to rate musical hits and recommendations deduced from auditor's profiles in the form of regional Internet radio. First, the system searches and retrieves probable music reviews from the Internet. Subsequently, the system carries out an evaluation and rating of those reviews. From this list of music hits, the system directly allows notation from our application. Finally, the system automatically creates the record list diffused each day depending on the region, the year season, the day hours and the age of listeners. Our system uses linguistics and statistic methods for classifying music opinions and data mining techniques for recommendation part needed for recorded list creation. The principal task is the creation of popular intelligent radio adaptive on auditor's age and region - IA-Regional-Radio.

  14. RADIO VARIABILITY IN SEYFERT NUCLEI

    International Nuclear Information System (INIS)

    Mundell, C. G.; Ferruit, P.; Nagar, N.; Wilson, A. S.

    2009-01-01

    Comparison of 8.4 GHz radio images of a sample of eleven, early-type Seyfert galaxies with previous observations reveals possible variation in the nuclear radio flux density in five of them over a seven year period. Four Seyferts (NGC 2110, NGC 3081, MCG -6-30-15, and NGC 5273) show a decline in their 8.4 GHz nuclear flux density between 1992 and 1999, while one (NGC 4117) shows an increase; the flux densities of the remaining six Seyferts (Mrk 607, NGC 1386, Mrk 620, NGC 3516, NGC 4968, and NGC 7465) have remained constant over this period. New images of MCG -5-23-16 are also presented. We find no correlation between radio variability and nuclear radio luminosity or Seyfert nuclear type, although the sample is small and dominated by type 2 Seyferts. Instead, a possible correlation between the presence of nuclear radio variability and the absence of hundred parsec-scale radio emission is seen, with four out of five marginally resolved or unresolved nuclei showing a change in nuclear flux density, while five out of six extended sources show no nuclear variability despite having unresolved nuclear sources. NGC 2110 is the only source in our sample with significant extended radio structure and strong nuclear variability (∼38% decline in nuclear flux density over seven years). The observed nuclear flux variability indicates significant changes are likely to have occurred in the structure of the nucleus on scales smaller than the VLA beam size (i.e., within the central ∼0.''1 (15 pc)), between the two epochs, possibly due to the appearance and fading of new components or shocks in the jet, consistent with previous detection of subparsec-scale nuclear structure in this Seyfert. Our results suggest that all Seyferts may exhibit variation in their nuclear radio flux density at 8.4 GHz, but that variability is more easily recognized in compact sources in which emission from the variable nucleus is not diluted by unresolved, constant flux density radio jet emission

  15. Radio science investigations with Voyager

    International Nuclear Information System (INIS)

    Eshleman, V.R.; Tyler, G.L.; Croft, T.A.

    1977-01-01

    The planned radio science investigations during the Voyager missions to the outer planets involve: (1) the use of the radio links to and from the spacecraft for occultation measurements of planetary and satellite atmospheres and ionospheres, the rings of Saturn, the solar corona, and the general-relativistic time delay for radiowave propagation through the Sun's gravity field; (2) radio link measurements of true or apparent spacecraft motion caused by the gravity fields of the planets, the masses of their larger satellites, and characteristics of the interplanetary medium; and (3) related measurements which could provide results in other areas, including the possible detection of long-wavelength gravitational radiation propagating through the Solar System. The measurements will be used to study: atmospheric and ionospheric structure, constituents, and dynamics; the sizes, radial distribution, total mass, and other characteristics of the particles in the rings of Saturn; interior models for the major planets and the mean density and bulk composition of a number of their satellites; the plasma density and dynamics of the solar corona and interplanetary medium; and certain fundamental questions involving gravitation and relativity. The instrumentation for these experiments is the same ground-based and spacecraft radio systems as will be used for tracking and communicating with the Voyager spacecraft, although several important features of these systems have been provided primarily for the radio science investigations. (Auth.)

  16. Observations of radio sources or 'What happened to radio stars?'

    International Nuclear Information System (INIS)

    Conway, R.G.

    1988-01-01

    A review is given of the early history of the interpretation of the radiation mechanisms following the discovery of the discrete radio sources, both galactic and extragalactic. The conflicting views which prevailed in the early fifties are discussed in some detail: some advocated thermal radiation from stars relatively close by, and others proposed the alternative that synchrotron radiation was responsible for the majority of the radio sources. Attention is drawn to the importance of high-resolution interferometry, whereby the structure of many of the sources could be obtained. Red-shift measurements and spectral distributions also played a part in determining distances and flux strengths at the sources. (U.K.)

  17. Electronic analogue simulator of radio cardiograms; Simulateur analogique electronique de radiocardiogrammes

    Energy Technology Data Exchange (ETDEWEB)

    Roux, G; Lansiart, A; Vernejoul, P de; Kellershohn, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The various parameters of the heart pump and of the blood circulation can be determined by radio-cardio-graphical techniques. The curves thus obtained can be more easily used in radiocardiography if the electronic analogue simulator described here is employed. The experimental and simulated radio-cardiograms are made to coincide by varying the electrical parameters of the simulator. Using simple charts it is possible to obtain directly the actual original physiological parameters from these electrical parameters. Some examples are given showing the excellent accuracy obtained in the determination of ejection indices by the simulator. (authors) [French] Les differents parametres de la pompe cardiaque et de la circulation sanguine peuvent etre determines par les techniques de radiocardiographie. L'exploitation des courbes obtenues en radiocardiographie est rendue plus aisee par l'utilisation du simulateur analogique electronique presente ici. Le radiocardiogramme experimental et le radiocardiogramme simule sont superposes en agissant sur les parametre electriques du simulateur. Par l'utilisation d'abaques simples, ces parametres electriques permettent de retrouver directement les parametres reels d'origine physiologique. Quelques exemples sont donnes montrant l'excellente precision obtenue dans la determination des indices d'ejection a l'aide du simulateur. (auteurs)

  18. Childhood Pars Planitis; Clinical Features and Outcomes

    Directory of Open Access Journals (Sweden)

    Homayoon Nikkhah

    2011-01-01

    Full Text Available Purpose: To evaluate the demographic and clinical features of childhood pars planitis, and to determine the therapeutic and visual outcomes of the disease. Methods: Medical records of pediatric patients (less than 16 years of age at diagnosis with pars planitis and at least 6 months of follow-up who were referred to Labbafinejad Medical Center, Tehran, Iran over a 22 year period were reviewed. Results: Overall, 117 eyes of 61 patients including 51 (83.6% male subjects were included. Mean age at the time of diagnosis was 7.8΁3.2 (range, 3-16 years. Mean best corrected visual acuity (BCVA was 0.88΁0.76 logMAR at presentation which improved to 0.39΁0.51 logMAR at final visit (P<0.001. Endotheliitis was present in 23 (19.6% eyes and was significantly more prevalent in subjects younger than 9 years (P=0.025. Cataract formation (41.9% and cystoid macular edema (19.7% were the most prevalent complications. Univariate regression analysis showed that better baseline visual acuity (OR=0.38, 95%CI 0.21-0.70, P=0.002, age older than 5 years at disease onset (OR=0.36, 95%CI 0.14-0.9, P=0.029, absence of endotheliitis (OR=0.39, 95%CI 0.15-0.99, P=0.047 and female gender (OR=3.77, 95%CI 1.03-13.93, P=0.046 were significantly associated with final BCVA of 20/40 or better. Conclusion: Childhood pars planitis was much more common among male subjects. Endotheliitis may be a sign of inflammation spillover and is more prevalent in younger patients. Visual prognosis is favorable in most patients with appropriate treatment.

  19. Radio Context Awareness and Applications

    Directory of Open Access Journals (Sweden)

    Luca Reggiani

    2013-01-01

    Full Text Available The context refers to “any information that can be used to characterize the situation of an entity, where an entity can be a person, place, or physical object.” Radio context awareness is defined as the ability of detecting and estimating a system state or parameter, either globally or concerning one of its components, in a radio system for enhancing performance at the physical, network, or application layers. In this paper, we review the fundamentals of context awareness and the recent advances in the main radio techniques that increase the context awareness and smartness, posing challenges and renewed opportunities to added-value applications in the context of the next generation of wireless networks.

  20. Modular Software-Defined Radio

    Directory of Open Access Journals (Sweden)

    Rhiemeier Arnd-Ragnar

    2005-01-01

    Full Text Available In view of the technical and commercial boundary conditions for software-defined radio (SDR, it is suggestive to reconsider the concept anew from an unconventional point of view. The organizational principles of signal processing (rather than the signal processing algorithms themselves are the main focus of this work on modular software-defined radio. Modularity and flexibility are just two key characteristics of the SDR environment which extend smoothly into the modeling of hardware and software. In particular, the proposed model of signal processing software includes irregular, connected, directed, acyclic graphs with random node weights and random edges. Several approaches for mapping such software to a given hardware are discussed. Taking into account previous findings as well as new results from system simulations presented here, the paper finally concludes with the utility of pipelining as a general design guideline for modular software-defined radio.

  1. Unseen cosmos the universe in radio

    CERN Document Server

    Graham-Smith, Francis

    2013-01-01

    Radio telescopes have transformed our understanding of the Universe. Pulsars, quasars, Big Bang cosmology: all are discoveries of the new science of radio astronomy. Here, Francis Graham-Smith describes the birth, development, and maturity of radio astronomy, from the first discovery of cosmic radio waves to its present role as a major part of modern astronomy. Radio is part of the electromagnetic spectrum, covering infra-red, visible light, ultraviolet, X-rays, and gamma-rays, and Graham-Smith explains why it is that radio waves give us a unique view of the Universe. Tracing the development o

  2. Reconfigurable radio systems network architectures and standards

    CERN Document Server

    Iacobucci, Maria Stella

    2013-01-01

    This timely book provides a standards-based view of the development, evolution, techniques and potential future scenarios for the deployment of reconfigurable radio systems.  After an introduction to radiomobile and radio systems deployed in the access network, the book describes cognitive radio concepts and capabilities, which are the basis for reconfigurable radio systems.  The self-organizing network features introduced in 3GPP standards are discussed and IEEE 802.22, the first standard based on cognitive radio, is described. Then the ETSI reconfigurable radio systems functional ar

  3. Miniature EVA Software Defined Radio

    Science.gov (United States)

    Pozhidaev, Aleksey

    2012-01-01

    As NASA embarks upon developing the Next-Generation Extra Vehicular Activity (EVA) Radio for deep space exploration, the demands on EVA battery life will substantially increase. The number of modes and frequency bands required will continue to grow in order to enable efficient and complex multi-mode operations including communications, navigation, and tracking applications. Whether conducting astronaut excursions, communicating to soldiers, or first responders responding to emergency hazards, NASA has developed an innovative, affordable, miniaturized, power-efficient software defined radio that offers unprecedented power-efficient flexibility. This lightweight, programmable, S-band, multi-service, frequency- agile EVA software defined radio (SDR) supports data, telemetry, voice, and both standard and high-definition video. Features include a modular design, an easily scalable architecture, and the EVA SDR allows for both stationary and mobile battery powered handheld operations. Currently, the radio is equipped with an S-band RF section. However, its scalable architecture can accommodate multiple RF sections simultaneously to cover multiple frequency bands. The EVA SDR also supports multiple network protocols. It currently implements a Hybrid Mesh Network based on the 802.11s open standard protocol. The radio targets RF channel data rates up to 20 Mbps and can be equipped with a real-time operating system (RTOS) that can be switched off for power-aware applications. The EVA SDR's modular design permits implementation of the same hardware at all Network Nodes concept. This approach assures the portability of the same software into any radio in the system. It also brings several benefits to the entire system including reducing system maintenance, system complexity, and development cost.

  4. Radio-opaque dental compositions

    International Nuclear Information System (INIS)

    Temin, S.C.

    1979-01-01

    Thorium oxide or tantalum oxide, or combinations thereof are used as the x-ray material for radio-opaque filler compositions having particular applicability in dental restorative compositions. The filler compositions contain from about 3% by weight to about 10% by weight, based on the total filler composition, of the x-ray absorbing materials and the remainder being conventional particulate glass or silica, quarts or ceramic filler material. The radio opaque filler compositions are insoluble and non-leachable in alkaline, acidic or neutral aqueous environments, are essentially non-toxic, are either essentially colorless or translucent, and are compatible with acrylic monomers and other polymerizable binder systems

  5. Synthesis imaging in radio astronomy

    International Nuclear Information System (INIS)

    Perley, R.A.; Schwab, F.R.; Bridle, A.H.

    1989-01-01

    Recent advances in techniques and instrumentation for radio synthesis imaging in astronomy are discussed in a collection of review essays. Topics addressed include coherence in radio astronomy, the interferometer in practice, primary antenna elements, cross correlators, calibration and editing, sensitivity, deconvolution, self-calibration, error recognition, and image analysis. Consideration is given to wide-field imaging (bandwidth and time-average smearing, noncoplanar arrays, and mosaicking), high-dynamic-range imaging, spectral-line imaging, VLBI, solar imaging with a synthesis telescope, synthesis imaging of spatially coherent objects, noise in images of very bright sources, synthesis observing strategies, and the design of aperture-synthesis arrays

  6. New discoveries with radio telescopes

    International Nuclear Information System (INIS)

    Schmidt, J.

    1985-01-01

    The author describes in a simple fashion the results obtained by astronomers from ETH Zurich using the broadband 7-m radio telescope in Switzerland to observe the sun over a period of six years. He explains the results in terms of our present understanding of the sun's workings. The astronomers found that a solar eruption is not a single event but consists of tens of thousands of small eruptions or spikes each only 200 km high and producing a burst of radio waves 10-100 times as intense as the background. (T.J.R.A.)

  7. Origin of solar radio waves

    International Nuclear Information System (INIS)

    Olmr, J.

    1977-01-01

    Solar radiowave radiation amounts to about 10 -7 of the total solar radiation. The solar atmosphere emits radiation of different wavelengths from a fraction of nanometer to kilometer waves. The solar radiowaves are of thermal origin and except for neutral hydrogen emission and solid body radio emission their emission always results from free electrons. The radiowave radiation active components were classified in several types, such as noise storms, flashes, flares, continuum, and flashes lasting for several minutes. The respective types are discussed and their origins shown. The mechanisms are described permitting the formation of radio waves of nonthermal origin, i.e., plasma oscillations, gyromagnetic emission, synchrotron and Cherenkov radiations. (J.P.)

  8. Intelligent Cognitive Radio Models for Enhancing Future Radio Astronomy Observations

    Directory of Open Access Journals (Sweden)

    Ayodele Abiola Periola

    2016-01-01

    Full Text Available Radio astronomy organisations desire to optimise the terrestrial radio astronomy observations by mitigating against interference and enhancing angular resolution. Ground telescopes (GTs experience interference from intersatellite links (ISLs. Astronomy source radio signals received by GTs are analysed at the high performance computing (HPC infrastructure. Furthermore, observation limitation conditions prevent GTs from conducting radio astronomy observations all the time, thereby causing low HPC utilisation. This paper proposes mechanisms that protect GTs from ISL interference without permanent prevention of ISL data transmission and enhance angular resolution. The ISL transmits data by taking advantage of similarities in the sequence of observed astronomy sources to increase ISL connection duration. In addition, the paper proposes a mechanism that enhances angular resolution by using reconfigurable earth stations. Furthermore, the paper presents the opportunistic computing scheme (OCS to enhance HPC utilisation. OCS enables the underutilised HPC to be used to train learning algorithms of a cognitive base station. The performances of the three mechanisms are evaluated. Simulations show that the proposed mechanisms protect GTs from ISL interference, enhance angular resolution, and improve HPC utilisation.

  9. Accouchement par forceps: indications et pronostic materno-foetal ...

    African Journals Online (AJOL)

    L'accouchement par voie basse, peut être parfois compromis par des facteurs maternels, foetaux ou materno-foetaux nécessitant des moyens thérapeutiques comme le forceps pour achever l'accouchement par voie naturelle. Le forceps, une méthode qui n'est pas sans risque pour la mère et le nouveau-né. Nous avons ...

  10. Perkembangan dan Problematika Radio Komunitas di Indonesia

    Directory of Open Access Journals (Sweden)

    Masduki .

    2013-12-01

    Full Text Available Abstract: This article is about the development of community radio in Indonesia, it is problems and solutions. Community radio in Indonesia developed as an alternative to both public radio and commercial radio after the fall of Soeharto in 1998. Two important features of community radio are that it provides all community members with equal access to information, enhancing their rights and obligations, access to justice, public accountability and also enables them to participate actively in radio management and production. Both features enhance people’s selfawareness and sense of belonging to a community. The expansion of the progressive, participatory, community ownership, and non-profit model of community radio, has become a third sector of communication beside the commercial or state media. The dynamic development of community radio in Indonesia faced several problems starting from it is definition, implementation of regulation until standards of programmes operation based on the concept of community approach and participation

  11. Interweave Cognitive Radio with Improper Gaussian Signaling

    KAUST Repository

    Hedhly, Wafa; Amin, Osama; Alouini, Mohamed-Slim

    2018-01-01

    Improper Gaussian signaling (IGS) has proven its ability in improving the performance of underlay and overlay cognitive radio paradigms. In this paper, the interweave cognitive radio paradigm is studied when the cognitive user employs IGS

  12. Contribution Towards Practical Cognitive Radios Systems

    KAUST Repository

    Ben Ghorbel, Mahdi

    2013-01-01

    to cognitive radio systems while taking into account practical constraints. Cogni- tive radios requires a capability to detect spectrum holes (spectrum sensing) and a scheduling flexibility to avoid the occupied spectrum and selectively use the empty spectrum

  13. The origin of cholesterol in chyle demonstrated by nuclear indicator methods; Origines du cholesterol du chyle mises en evidence par la methode des indicateurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, M

    1962-07-01

    In order to obtain information about the mechanism of the intestinal absorption of cholesterol, rats having a lymphatic abdominal fistula are used. The animals receive either 4-{sup 14}C- cholesterol subcutaneously or orally, or the 1-{sup 14}C acetate. The study of the specific radio-activities of the cholesterol in chyle, in serum, in the lining, and in the intestinal contents makes it possible to define the roles played by the transfer cholesterol from the serum, by the cholesterol synthesised intestinally, and by the absorption cholesterol, in the formations of the lymph and of the chylomicrons. A new theory is proposed for the mechanism of cholesterol absorption. (author) [French] Pour obtenir des renseignements concernant le mecanisme de l'absorption intestinale du cholesterol, on utilise des rats porteurs d'une fistule lymphatique abdominale. Les animaux recoivent soit du cholesterol 4-{sup 14}C par voie sous-cutanee ou par voie orale, soit de l'acetate 1-{sup 14}C. L'etude des radioactivites specifiques du cholesterol du chyle, du serum, de la paroi et du contenu intestinal permet de preciser les roles joues par le cholesterol de transfert d'origine serique, par le cholesterol de synthese intestinale et par le cholesterol d'absorption, dans la formation de la lymphe et des chylomicrons. Une theorie nouvelle concernant le mecanisme de l'absorption du cholesterol est proposee. (auteur)

  14. Educational Radio: The Brazilian Experience.

    Science.gov (United States)

    Speyer, Anne Marie

    1983-01-01

    Explains the value of radio for literacy education, gives a synopsis of the development of educational broadcasting in Brazil, and describes the Movement of Basic Education, a program designed to meet the needs of members of rural communities in their daily working lives. (EAO)

  15. Hybrid spread spectrum radio system

    Science.gov (United States)

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  16. Radio frequency modulation made easy

    CERN Document Server

    Faruque, Saleh

    2017-01-01

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

  17. The isotropic radio background revisited

    Energy Technology Data Exchange (ETDEWEB)

    Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I–10125 Torino (Italy); Lineros, Roberto A. [Instituto de Física Corpuscular – CSIC/U. Valencia, Parc Científic, calle Catedrático José Beltrán, 2, E-46980 Paterna (Spain); Taoso, Marco, E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: taoso@cea.fr [Institut de Physique Théorique, CEA/Saclay, F-91191 Gif-sur-Yvette Cédex (France)

    2014-04-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky.

  18. The isotropic radio background revisited

    International Nuclear Information System (INIS)

    Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.; Taoso, Marco

    2014-01-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky

  19. Utrecht and Galactic Radio Astronomy

    NARCIS (Netherlands)

    van Woerden, H.

    Important roles in early Dutch Galactic radio astronomy were played by several Utrecht astronomers: Van de Hulst, Minnaert and Houtgast. The poster announcing the conference contained a number of pictures referring to scientific achievements of the Astronomical Institute Utrecht. One of these

  20. A repeating fast radio burst.

    Science.gov (United States)

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  1. Quality in radio-immunology

    International Nuclear Information System (INIS)

    Hegesippe, Michel

    1982-01-01

    The author outlines the technique of radio-immunological analysis (RIA) which is now widely used for neo-natal detection of congenital hyperthyroidism. He describes the methods and controls that are called for - as regards the specificity of doses, the sensitivity and reliability of the separation technique - to guarantee the quality of RIA and the validity of its results [fr

  2. Newnes radio and electronics engineer's pocket book

    CERN Document Server

    Moorshead, H W; Perry, J

    1978-01-01

    Newnes Radio and Electronics Engineer's Pocket Book, Fifteenth Edition provides reference of the information relevant in radio and electronics engineering. The book presents tables, illustrations, and diagrams of various data used in radio and electronics engineering. The coverage of the text includes abbreviations and symbols, electrical equations, and code conversions. The text will be useful to engineers, technicians, and other professionals who require a reference about the different aspects of radio and electronics.

  3. IRAS observations of radio-quiet and radio-loud quasars

    Science.gov (United States)

    Neugebauer, G.; Soifer, B. T.; Miley, G.; Habing, H. J.; Young, E.; Low, F. J.; Beichman, C. A.; Clegg, P. E.; Harris, S.; Rowan-Robinson, M.

    1984-01-01

    Observations from 12 to 100 microns are presented of two radio-quiet and three radio-loud quasars. Over this wavelength range, all five have grossly similar continuum energy distributions. The continua of the radio-loud quasars are consistent with synchrotron radiation. There is an indication, however, of excess 100 micron emission in the two radio-quiet quasars.

  4. Division B Commission 40: Radio Astronomy

    NARCIS (Netherlands)

    Chapman, Jessica M.; Giovaninni, Gabriele; Taylor, Russell; Carilli, Christopher; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin L.; Lazio, Joseph; Morganti, Raffaella; Nan, Rendong; Rubio, Monica; Shastri, Prjaval; Kellermann, Ken; Ekers, Ronald; Ohishi, Masatoshi

    2016-01-01

    IAU Commission 40 for Radio Astronomy (hereafter C40) brought together scientists and engineers who carry out observational and theoretical research in radio astronomy and who develop and operate the ground and space-based radio astronomy facilities and instrumentation. As of June 2015, the

  5. Exploring Community Radio Programming Practices to Inform ...

    African Journals Online (AJOL)

    A collective case study (multi-site) design was used to probe educational programming practices used in community radio. The paper explores how community radio station programming engages listeners in community generated education programmes that are produced through collaborative work with radio listener clubs.

  6. Politics and Radio in the 1924 Campaign.

    Science.gov (United States)

    Berkman, Dave

    1987-01-01

    Discusses the relation between radio broadcasting and politics in the 1924 presidential campaign, focusing on newspaper and magazine coverage. Notes radio's influence on candidate image, the aspect of censorship, and the use of radio during the campaign and after the election. (MM)

  7. PAR1 activation affects the neurotrophic properties of Schwann cells.

    Science.gov (United States)

    Pompili, Elena; Fabrizi, Cinzia; Somma, Francesca; Correani, Virginia; Maras, Bruno; Schininà, Maria Eugenia; Ciraci, Viviana; Artico, Marco; Fornai, Francesco; Fumagalli, Lorenzo

    2017-03-01

    Protease-activated receptor-1 (PAR1) is the prototypic member of a family of four G-protein-coupled receptors that signal in response to extracellular proteases. In the peripheral nervous system, the expression and/or the role of PARs are still poorly investigated. High PAR1 mRNA expression was found in the rat dorsal root ganglia and the signal intensity of PAR1 mRNA increased in response to sciatic nerve transection. In the sciatic nerve, functional PAR1 receptor was reported at the level of non-compacted Schwann cell myelin microvilli of the nodes of Ranvier. Schwann cells are the principal population of glial cells of the peripheral nervous system which myelinate axons playing an important role during axonal regeneration and remyelination. The present study was undertaken in order to determine if the activation of PAR1 affects the neurotrophic properties of Schwann cells. Our results suggest that the stimulation of PAR1 could potentiate the Schwann cell ability to favour nerve regeneration. In fact, the conditioned medium obtained from Schwann cell cultures challenged with a specific PAR1 activating peptide (PAR1 AP) displays increased neuroprotective and neurotrophic properties with respect to the culture medium from untreated Schwann cells. The proteomic analysis of secreted proteins in untreated and PAR1 AP-treated Schwann cells allowed the identification of factors differentially expressed in the two samples. Some of them (such as macrophage migration inhibitory factor, matrix metalloproteinase-2, decorin, syndecan 4, complement C1r subcomponent, angiogenic factor with G patch and FHA domains 1) appear to be transcriptionally regulated after PAR1 AP treatment as shown by RT-PCR. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The Effect of Solar Radiation on Radio Signal for Radio Astronomy Purposes

    International Nuclear Information System (INIS)

    Nor Hazmin Sabri; Atiq Wahidah Azlan; Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Zainol Abidin Ibrahim; Wan Zul Adli Wan Mokhtar

    2015-01-01

    Radio astronomy is a subfields of astronomy which is discovers the celestial objects at radio frequencies. Observation in radio astronomy is conducted using single antenna or array of antennas, known as radio telescope. Other than that, radio astronomy also holds an advantage over other alternatives to optical astronomy due to its capability of observing from the ground level. In this study, the effect of solar radiation that contributes the Radio Frequency Interferences (RFI) is reviewed. The low RFI level is required to set up the radio telescope for radio astronomy observation. The effect of solar radiation on radio signal was investigated by determining the RFI pattern using spectrum analyzer. The solar radiation data was obtained from weather station located at KUSZA Observatory, East Coast Environmental Research Institute (ESERI), UniSZA. We can conclude that the solar radiation factor give the minimum significant effect to radio signal. (author)

  9. Taare Zameen Par and dyslexic savants.

    Science.gov (United States)

    Chakravarty, Ambar

    2009-04-01

    The film Taare Zameen Par (Stars upon the Ground) portrays the tormented life at school and at home of a child with dyslexia and his eventual success after his artistic talents are discovered by his art teacher at the boarding school. The film hints at a curious neurocognitive phenomenon of creativity in the midst of language disability, as exemplified in the lives of people like Leonardo da Vinci and Albert Einstein, both of whom demonstrated extraordinary creativity even though they were probably affected with developmental learning disorders. It has been hypothesized that a developmental delay in the dominant hemisphere most likely 'disinhibits' the nondominant parietal lobe, unmasking talents-artistic or otherwise-in some such individuals. It has been suggested that, in remedial training, children with learning disorders be encouraged to develop such hidden talents to full capacity, rather than be subjected to the usual overemphasis on the correction of the disturbed coded symbol operations.

  10. Soudage de bois feuillus par friction rotationnelle

    OpenAIRE

    Belleville, Benoît

    2012-01-01

    Les différentes colles utilisées actuellement par l’industrie du meuble au Canada nécessitent des temps de polymérisation constituant un goulot dans la production des meubles et limitant l’atteinte de la production unitaire. Ces adhésifs synthétiques généralement issus de la pétrochimie nécessitent énormément d’énergie lors de leur confection. L’utilisation de connecteurs métalliques ou plastiques, quant à elle, limite les phases de découpage et sablage subséquentes. La présence d’adhésifs et...

  11. Radio Astronomy Explorer (RAE) 1 observations of terrestrial radio noise

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.

    1971-01-01

    Radio Astonomy Explorer (RAE) 1 data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 or more db higher than cosmic noise background. Maximum terrestrial noise is observed when RAE is over the dark side of the Earth in the neighborhood of equatorial continental land masses where thunderstorms occur most frequently. The observed noise level is 30-40 db lower with RAE over oceans.

  12. Fast Radio Bursts and Radio Transients from Black Hole Batteries

    OpenAIRE

    Mingarelli, Chiara M. F.; Levin, Janna; Lazio, T. Joseph W.

    2015-01-01

    Most black holes (BHs) will absorb a neutron star (NS) companion fully intact without tidal disruption, suggesting the pair will remain dark to telescopes. Even without tidal disruption, electromagnetic (EM) luminosity is generated from the battery phase of the binary when the BH interacts with the NS magnetic field. Originally, the luminosity was expected to be in high-energy X-rays or gamma-rays, however, we conjecture that some of the battery power is emitted in the radio bandwidth. While ...

  13. TMS suppression of right pars triangularis, but not pars opercularis, improves naming in aphasia

    Science.gov (United States)

    Naeser, Margaret A.; Martin, Paula I.; Theoret, Hugo; Kobayashi, Masahito; Fregni, Felipe; Nicholas, Marjorie; Tormos, Jose M.; Steven, Megan S.; Baker, Errol H.; Pascual-Leone, Alvaro

    2011-01-01

    This study sought to discover if an optimum 1 cm2 area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1 Hz rTMS was applied to suppress different RH ROIs in eight aphasia cases. Picture naming and response time (RT) were examined before, and immediately after rTMS. In aphasia patients, suppression of right pars triangularis (PTr) led to significant increase in pictures named, and significant decrease in RT. Suppression of right pars opercularis (POp), however, led to significant increase in RT, but no change in number of pictures named. Eight normals named all pictures correctly; similar to aphasia patients, RT significantly decreased following rTMS to suppress right PTr, versus right POp. Differential effects following suppression of right PTr versus right POp suggest different functional roles for these regions. PMID:21864891

  14. ParABS system in chromosome partitioning in the bacterium Myxococcus xanthus.

    Directory of Open Access Journals (Sweden)

    Antonio A Iniesta

    Full Text Available Chromosome segregation is an essential cellular function in eukaryotic and prokaryotic cells. The ParABS system is a fundamental player for a mitosis-like process in chromosome partitioning in many bacterial species. This work shows that the social bacterium Myxococcus xanthus also uses the ParABS system for chromosome segregation. Its large prokaryotic genome of 9.1 Mb contains 22 parS sequences near the origin of replication, and it is shown here that M. xanthus ParB binds preferentially to a consensus parS sequence in vitro. ParB and ParA are essential for cell viability in M. xanthus as in Caulobacter crescentus, but unlike in many other bacteria. Absence of ParB results in anucleate cells, chromosome segregation defects and loss of viability. Analysis of ParA subcellular localization shows that it clusters at the poles in all cells, and in some, in the DNA-free cell division plane between two chromosomal DNA masses. This ParA localization pattern depends on ParB but not on FtsZ. ParB inhibits the nonspecific interaction of ParA with DNA, and ParA colocalizes with chromosomal DNA only when ParB is depleted. The subcellular localization of ParB suggests a single ParB-parS complex localized at the edge of the nucleoid, next to a polar ParA cluster, with a second ParB-parS complex migrating after the replication of parS takes place to the opposite nucleoid edge, next to the other polar ParA cluster.

  15. Concerning the dynamic instability of actin homolog ParM

    International Nuclear Information System (INIS)

    Popp, David; Yamamoto, Akihiro; Iwasa, Mitsusada; Narita, Akihiro; Maeda, Kayo; Maeda, Yuichiro

    2007-01-01

    Using in vitro TIRF- and electron-microscopy, we reinvestigated the dynamics of native ParM, a prokaryotic DNA segregation protein and actin homolog. In contrast to a previous study, which used a cysteine ParM mutant, we find that the polymerization process of wild type ATP-ParM filaments consists of a polymerization phase and a subsequent steady state phase, which is dynamically unstable, like that of microtubules. We find that the apparent bidirectional polymerization of ParM, is not due to the intrinsic nature of this filament, but results from ParM forming randomly oriented bundles in the presence of crowding agents. Our results imply, that in the bacterium, ParM filaments spontaneously form bipolar bundles. Due to their intrinsic dynamic instability, ParM bundles can efficiently 'search' the cytoplasmic lumen for DNA, bind it equally well at the bipolar ends and segregate it approximately symmetrically, by the insertion of ParM subunits at either end

  16. The protein kinase SIK downregulates the polarity protein Par3

    DEFF Research Database (Denmark)

    Vanlandewijck, Michael; Dadras, Mahsa Shahidi; Lomnytska, Marta

    2018-01-01

    on Par3. Functionally, this mechanism impacts on tight junction downregulation. Furthermore, SIK contributes to the loss of epithelial polarity and examination of advanced and invasive human cancers of diverse origin displayed high levels of SIK expression and a corresponding low expression of Par3...

  17. Radio halo sources in clusters of galaxies

    International Nuclear Information System (INIS)

    Hanisch, R.J.

    1986-01-01

    Radio halo sources remain one of the most enigmatic of all phenomena related to radio emission from galaxies in clusters. The morphology, extent, and spectral structure of these sources are not well known, and the models proposed to explain them suffer from this lack of observational detail. However, recent observations suggest that radio halo sources may be a composite of relic radio galaxies. The validity of this model could be tested using current and planned high resolutions, low-frequency radio telescopes. 31 references

  18. Radio investigations of clusters of galaxies

    International Nuclear Information System (INIS)

    Valentijn, E.A.

    1978-01-01

    This thesis contains a number of papers of the series entitled, A Westerbork Survey of Rich Clusters of Galaxies. The primary aim was to study the radio characteristics of cluster galaxies and especially the question whether their ''radio-activity'' is influenced by their location inside a cluster. It is enquired whether the presence of an intra-cluster medium (ICM), or the typical cluster evolution or cluster dynamical processes can give rise to radio-observable effects on the behaviour of cluster galaxies. 610 MHz WSRT observations of the Coma cluster (and radio observations of the Hercules supercluster) are presented. Extended radio sources in Abell clusters are then described. (Auth.)

  19. Propagation engineering in radio links design

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2013-01-01

    Propagation Engineering in Radio Link Design covers the basic principles of radiowaves propagation in a practical manner.  This fundamental understanding enables the readers to design radio links efficiently. This book elaborates on new achievements as well as recently developed propagation models.  This is in addition to a comprehensive overview of fundamentals of propagation in various scenarios. It examines theoretical calculations, approaches and applied procedures needed for radio links design. The authors study and analysis of the main propagation phenomena and its mechanisms based on the recommendations of International Telecommunications Union, (ITU). The book has been organized in 9 chapters and examines the role of antennas and passive reflectors in radio services, propagation mechanisms related to radar, satellite, short distance, broadcasting and trans-horizon radio links, with two chapters devoted to radio noise and main  parameters of radio link design. The book presents some 278 illustration...

  20. Recombination in the human Pseudoautosomal region PAR1.

    Directory of Open Access Journals (Sweden)

    Anjali G Hinch

    2014-07-01

    Full Text Available The pseudoautosomal region (PAR is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome.

  1. Precision Geodesy via Radio Interferometry.

    Science.gov (United States)

    Hinteregger, H F; Shapiro, I I; Robertson, D S; Knight, C A; Ergas, R A; Whitney, A R; Rogers, A E; Moran, J M; Clark, T A; Burke, B F

    1972-10-27

    Very-long-baseline interferometry experiments, involving observations of extragalactic radio sources, were performed in 1969 to determine the vector separations between antenna sites in Massachusetts and West Virginia. The 845.130-kilometer baseline was estimated from two separate experiments. The results agreed with each other to within 2 meters in all three components and with a special geodetic survey to within 2 meters in length; the differences in baseline direction as determined by the survey and by interferometry corresponded to discrepancies of about 5 meters. The experiments also yielded positions for nine extragalactic radio sources, most to within 1 arc second, and allowed the hydrogen maser clocks at the two sites to be synchronized a posteriori with an uncertainty of only a few nanoseconds.

  2. Recent radio studies of SNR

    International Nuclear Information System (INIS)

    Dickel, J.R.

    1983-01-01

    SNR can generally be recognized as extended sources of continuum radio emission with non-thermal spectra located near the galactic plane. The author describes the kinds of observations currently being obtained and what they tell us about the objects. The data include continuum observations which can reach resolutions of about 1 arcsec using aperture synthesis techniques and also spectral line observations of the interstellar matter being encountered by the remnants. (Auth.)

  3. Superconducting Radio-Frequency Cavities

    Science.gov (United States)

    Padamsee, Hasan S.

    2014-10-01

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

  4. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1976-01-01

    Identifications are suggested for 36 radio sources from the southern zones of the Parkes 2700 MHz survey, 28 with galaxies, six with confirmed and two with suggested quasi-stellar objects. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for nine of the objects and for five previously suggested identifications. (author)

  5. LEP Radio Frequency Copper Cavity

    CERN Multimedia

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

  6. Expanding radio astronomy in Africa

    International Nuclear Information System (INIS)

    Gaylard, M J

    2013-01-01

    The Square Kilometre Array (SKA) Organisation announced in May 2012 that its members had agreed on a dual site solution for the SKA [1]. South Africa's bid for hosting the SKA has caused a ramp up of radio astronomy in Africa. To develop technology towards the SKA, the South African SKA Project (SKA SA) built a protoype radio telescope in 2007, followed in 2010 the seven antenna Karoo Array Telescope (KAT-7). Next is the 64 antenna MeerKAT, which will merge into SKA Phase 1 in Africa. As SKA Phase 2 is intended to add a high resolution capability with baselines out to 3000 km, the SKA SA brought in partner countries in Africa to host outstations. South Africa has been working with the partners to build capacity to operate the SKA and to benefit from it. The SA Department of Science and Technology (DST) developed a proposal to establish radio telescopes in the partner countries to provide hands-on learning and a capability for Very Long Baseline Interferometry (VLBI) research. Redundant 30 m class satellite antennas are being incorporated in this project.

  7. Radio outbursts in extragalactic sources

    International Nuclear Information System (INIS)

    Kinzel, W.M.

    1989-01-01

    Three aspects of the flux density variability of extragalactic radio sources were examined: millimeter wavelength short timescale variability, the spectral evolution of outbursts, and whether the outbursts are periodically spaced. Observations of extragalactic radio sources were conducted using the Five College Radio Astronomy Observatory between January and June 1985 at 88.2 GHz and during June and July 1985 at 40.0 GHz. Many of the sources exhibited significant flux density variations during the observing span. In addition, the most rapid variations observed were comparable with those reported in previous works. Two sources, 0355+50 and OJ287, both exhibited outbursts whose rise and fall timescales were less than a month. An anomalous flux density dropout was observed in 3C446 and was interpreted as an occultation event. Data at five frequencies between 2.7 and 89.6 GHz from the Dent-Balonek monitoring program were used to investigate the spectral evolution of eight outbursts. Outburst profile fitting was used to deconvolve the individual outbursts from one another at each frequency. The fit profiles were used to generate multiple epoch spectra to investigate the evolution of the outbursts. A phase residual minimization method was used to examine four sources for periodic behavior

  8. Advances in solar radio astronomy

    Science.gov (United States)

    Kundu, M. R.

    1982-01-01

    The status of the observations and interpretations of the sun's radio emission covering the entire radio spectrum from millimeter wavelengths to hectometer and kilometer wavelengths is reviewed. Emphasis is given to the progress made in solar radio physics as a result of recent advances in plasma and radiation theory. It is noted that the capability now exists of observing the sun with a spatial resolution of approximately a second of arc and a temporal resolution of about a millisecond at centimeter wavelengths and of obtaining fast multifrequency two-dimensional pictures of the sun at meter and decameter wavelengths. A summary is given of the properties of nonflaring active regions at millimeter, centimeter, and meter-decameter wavelengths. The properties of centimeter wave bursts are discussed in connection with the high spatial resolution observations. The observations of the preflare build-up of an active region are reviewed. High spatial resolution observations (a few seconds of arc to approximately 1 arcsec) are discussed, with particular attention given to the one- and two-dimensional maps of centimeter-wavelength burst sources.

  9. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  10. Parámetros de Transferencia de Materia en el Secado de Frutas, sin Necesidad de Datos de Disminución de Volumen Mass Transfer Parameters in Fruit Drying, without using Shrinkage Data

    OpenAIRE

    Sebastião R Ferreira; Antônio R. S Costa

    2010-01-01

    Se desarrolló una metodología analítica para evaluar parámetros de transferencia de materia en el secado de frutas cilindricas, sin necesidad de conocer datos de disminución de volumen, pero admitiendo implícitamente disminución de su radio en el proceso R. Con el procedimiento se predice el coeficiente externo de transferencia de materia k m, la difusividad efectiva del agua en frutos De f, el número de Biot Bi y el radio promedio Rm durante el secado. Para probar la metodología es necesario...

  11. PARs for combustible gas control in advanced light water reactors

    International Nuclear Information System (INIS)

    Hosler, J.; Sliter, G.

    1997-01-01

    This paper discusses the progress being made in the United States to introduce passive autocatalytic recombiner (PAR) technology as a cost-effective alternative to electric recombiners for controlling combustible gas produced in postulated accidents in both future Advanced Light Water Reactors (ALWRs) and certain U. S. operating nuclear plants. PARs catalytically recombine hydrogen and oxygen, gradually producing heat and water vapor. They have no moving parts and are self-starting and self-feeding, even under relatively cold and wet containment conditions. Buoyancy of the hot gases they create sets up natural convective flow that promotes mixing of combustible gases in a containment. In a non-inerted ALWR containment, two approaches each employing a combination of PARs and igniters are being considered to control hydrogen in design basis and severe accidents. In pre-inerted ALWRs, PARs alone control radiolytic oxygen produced in either accident type. The paper also discusses regulatory feedback regarding these combustible gas control approaches and describes a test program being conducted by the Electric Power Research Institute (EPRI) and Electricite de France (EdF) to supplement the existing PAR test database with performance data under conditions of interest to U.S. plants. Preliminary findings from the EPRI/EdF PAR model test program are included. Successful completion of this test program and confirmatory tests being sponsored by the U. S. NRC are expected to pave the way for use of PARs in ALWRs and operating plants. (author)

  12. Sources of the Radio Background Considered

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  13. Radio y cultura: una propuesta de radio ciudadana en Internet

    Directory of Open Access Journals (Sweden)

    Mauricio Andrés Álvarez-Moreno

    2015-01-01

    Full Text Available El presente artículo es resultado de la investigación para optar a título de magíster “La Peña Cultural: modelo de radio ciudadana en Internet”, realizada durante los años 2013 y 2014 para la Universidad de Medellín. En ella se realiza una exploración de la radio en Internet como plataforma con herramientas multimediales que podrían afianzar la formación de ciudadanía reflexiva por medio de contenidos de promoción cultural. De la misma manera, identifica, a partir de un rastreo de emisoras en Colombia, cómo esas herramientas –las redes sociales, podcasts, chats, canales de video y nuevas formas comunicativas– permiten la participación activa de los ciudadanos en su producción. Rescatar el uso de tecnologías que facilitan la comunicación, como la radio en Internet, para reconocer y recuperar el valor de la promoción cultural propia de un estado en aras de la formación de una ciudadanía reflexiva, es el acercamiento que se hizo a partir de la etnografía y la investigación aplicada y que ahora se expone en este artículo. Es la forma en que los ciudadanos podrían converger en un medio de comunicación para producir contenidos que fortalezcan su identidad cultural o, si se quiere, su visión de nación. Es la apuesta por establecer una alternativa a los ya tradicionales modelos, una guía para la comunidad interesada en promover una ciudadanía reflexiva del patrimonio cultural. Palabras clave

  14. FAST RADIO BURSTS AND RADIO TRANSIENTS FROM BLACK HOLE BATTERIES

    Energy Technology Data Exchange (ETDEWEB)

    Mingarelli, Chiara M. F. [TAPIR, MC 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Levin, Janna [Institute for Strings, Cosmology and Astroparticle Physics (ISCAP), Columbia University, New York, NY 10027 (United States); Lazio, T. Joseph W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2015-12-01

    Most black holes (BHs) will absorb a neutron star (NS) companion fully intact without tidal disruption, suggesting the pair will remain dark to telescopes. Even without tidal disruption, electromagnetic (EM) luminosity is generated from the battery phase of the binary when the BH interacts with the NS magnetic field. Originally, the luminosity was expected to be in high-energy X-rays or gamma-rays, however, we conjecture that some of the battery power is emitted in the radio bandwidth. While the luminosity and timescale are suggestive of fast radio bursts (FRBs; millisecond-scale radio transients) NS–BH coalescence rates are too low to make these a primary FRB source. Instead, we propose that the transients form a FRB sub-population, distinguishable by a double peak with a precursor. The rapid ramp-up in luminosity manifests as a precursor to the burst which is 20%–80% as luminous given 0.5 ms timing resolution. The main burst arises from the peak luminosity before the merger. The post-merger burst follows from the NS magnetic field migration to the BH, causing a shock. NS–BH pairs are especially desirable for ground-based gravitational wave (GW) observatories since the pair might not otherwise be detected, with EM counterparts greatly augmenting the scientific leverage beyond the GW signal. The EM signal’s ability to break degeneracies in the parameters encoded in the GW and probe the NS magnetic field strength is quite valuable, yielding insights into open problems in NS magnetic field decay.

  15. FAST RADIO BURSTS AND RADIO TRANSIENTS FROM BLACK HOLE BATTERIES

    International Nuclear Information System (INIS)

    Mingarelli, Chiara M. F.; Levin, Janna; Lazio, T. Joseph W.

    2015-01-01

    Most black holes (BHs) will absorb a neutron star (NS) companion fully intact without tidal disruption, suggesting the pair will remain dark to telescopes. Even without tidal disruption, electromagnetic (EM) luminosity is generated from the battery phase of the binary when the BH interacts with the NS magnetic field. Originally, the luminosity was expected to be in high-energy X-rays or gamma-rays, however, we conjecture that some of the battery power is emitted in the radio bandwidth. While the luminosity and timescale are suggestive of fast radio bursts (FRBs; millisecond-scale radio transients) NS–BH coalescence rates are too low to make these a primary FRB source. Instead, we propose that the transients form a FRB sub-population, distinguishable by a double peak with a precursor. The rapid ramp-up in luminosity manifests as a precursor to the burst which is 20%–80% as luminous given 0.5 ms timing resolution. The main burst arises from the peak luminosity before the merger. The post-merger burst follows from the NS magnetic field migration to the BH, causing a shock. NS–BH pairs are especially desirable for ground-based gravitational wave (GW) observatories since the pair might not otherwise be detected, with EM counterparts greatly augmenting the scientific leverage beyond the GW signal. The EM signal’s ability to break degeneracies in the parameters encoded in the GW and probe the NS magnetic field strength is quite valuable, yielding insights into open problems in NS magnetic field decay

  16. uPAR as anti-cancer target

    DEFF Research Database (Denmark)

    Lund, Ida K; Illemann, Martin; Thurison, Tine

    2011-01-01

    , and a potential diagnostic and predictive impact of the different uPAR forms has been reported. Hence, pericellular proteolysis seems to be a suitable target for anti-cancer therapy and numerous approaches have been pursued. Targeting of this process may be achieved by preventing the binding of uPA to u...... using mouse monoclonal antibodies (mAbs) against mouse uPA or uPAR. These reagents will target uPA and uPAR in both stromal cells and cancer cells, and their therapeutic potential can now be assessed in syngenic mouse cancer models....

  17. Limnological database for Par Pond: 1959 to 1980

    International Nuclear Information System (INIS)

    Tilly, L.J.

    1981-03-01

    A limnological database for Par Pond, a cooling reservoir for hot reactor effluent water at the Savannah River Plant, is described. The data are derived from a combination of research and monitoring efforts on Par Pond since 1959. The approximately 24,000-byte database provides water quality, primary productivity, and flow data from a number of different stations, depths, and times during the 22-year history of the Par Pond impoundment. The data have been organized to permit an interpretation of the effects of twenty years of cooling system operations on the structure and function of an aquatic ecosystem

  18. An overview and guide: planning instructional radio.

    Science.gov (United States)

    Imhoof, M

    1984-03-01

    Successful instructional radio projects require both comprehensive and complex planning. The instructional radio planning team needs to have knowledge and capabilities in several technical, social, and educational areas. Among other skills, the team must understand radio, curriculum design, the subject matter being taught, research and evaluation, and the environment in which the project operates. Once a basic approach to educational planning has been selected and broad educational goals set, radio may be selected as a cost effective means of achieving some of the goals. Assuming radio is a wise choice, there are still several factors which must be analyzed by a team member who is a radio specialist. The most obvious consideration is the inventory and evaluation of the facilities: studios; broadcast, recording, and transmission equipment; classroom radios; and so on. Capabilities of broadcast personnel are another consideration. Initial radio lessons need to teach the learners how to listen to the radio if they have no previous experience with institutional radio broadcasts. A captive, inschool audience ready to listen to radio instructions requires a different use of the medium than a noncaptive audience. With the noncaptive audience, the educational broadcaster must compete with entertaining choices from other media and popular activities and pastimes of the community. The most complex knowledge and analysis required in planning instructional radio concerns the relationship of the content to the medium. Environmental factors are important in planning educational programs. The physical environment may present several constraints on the learning experience and the use of radio. The most obvious is the effect of climate and terrain on the quality of radio reception. The physical environment is easily studied through experience in the target area, but this knowledge plays a significant role in designing effective learning materials for specific learners. Social

  19. Protease-activated receptor (PAR2, but not PAR1, is involved in collateral formation and anti-inflammatory monocyte polarization in a mouse hind limb ischemia model.

    Directory of Open Access Journals (Sweden)

    Lisa G van den Hengel

    Full Text Available AIMS: In collateral development (i.e. arteriogenesis, mononuclear cells are important and exist as a heterogeneous population consisting of pro-inflammatory and anti-inflammatory/repair-associated cells. Protease-activated receptor (PAR1 and PAR2 are G-protein-coupled receptors that are both expressed by mononuclear cells and are involved in pro-inflammatory reactions, while PAR2 also plays a role in repair-associated responses. Here, we investigated the physiological role of PAR1 and PAR2 in arteriogenesis in a murine hind limb ischemia model. METHODS AND RESULTS: PAR1-deficient (PAR1-/-, PAR2-deficient (PAR2-/- and wild-type (WT mice underwent femoral artery ligation. Laser Doppler measurements revealed reduced post-ischemic blood flow recovery in PAR2-/- hind limbs when compared to WT, while PAR1-/- mice were not affected. Upon ischemia, reduced numbers of smooth muscle actin (SMA-positive collaterals and CD31-positive capillaries were found in PAR2-/- mice when compared to WT mice, whereas these parameters in PAR1-/- mice did not differ from WT mice. The pool of circulating repair-associated (Ly6C-low monocytes and the number of repair-associated (CD206-positive macrophages surrounding collaterals in the hind limbs were increased in WT and PAR1-/- mice, but unaffected in PAR2-/- mice. The number of repair-associated macrophages in PAR2-/- hind limbs correlated with CD11b- and CD115-expression on the circulating monocytes in these animals, suggesting that monocyte extravasation and M-CSF-dependent differentiation into repair-associated cells are hampered. CONCLUSION: PAR2, but not PAR1, is involved in arteriogenesis and promotes the repair-associated response in ischemic tissues. Therefore, PAR2 potentially forms a new pro-arteriogenic target in coronary artery disease (CAD patients.

  20. Novel role for proteinase-activated receptor 2 (PAR2) in membrane trafficking of proteinase-activated receptor 4 (PAR4).

    Science.gov (United States)

    Cunningham, Margaret R; McIntosh, Kathryn A; Pediani, John D; Robben, Joris; Cooke, Alexandra E; Nilsson, Mary; Gould, Gwyn W; Mundell, Stuart; Milligan, Graeme; Plevin, Robin

    2012-05-11

    Proteinase-activated receptors 4 (PAR(4)) is a class A G protein-coupled receptor (GPCR) recognized through the ability of serine proteases such as thrombin and trypsin to mediate receptor activation. Due to the irreversible nature of activation, a fresh supply of receptor is required to be mobilized to the cell surface for responsiveness to agonist to be sustained. Unlike other PAR subtypes, the mechanisms regulating receptor trafficking of PAR(4) remain unknown. Here, we report novel features of the intracellular trafficking of PAR(4) to the plasma membrane. PAR(4) was poorly expressed at the plasma membrane and largely retained in the endoplasmic reticulum (ER) in a complex with the COPI protein subunit β-COP1. Analysis of the PAR(4) protein sequence identified an arginine-based (RXR) ER retention sequence located within intracellular loop-2 (R(183)AR → A(183)AA), mutation of which allowed efficient membrane delivery of PAR(4). Interestingly, co-expression with PAR(2) facilitated plasma membrane delivery of PAR(4), an effect produced through disruption of β-COP1 binding and facilitation of interaction with the chaperone protein 14-3-3ζ. Intermolecular FRET studies confirmed heterodimerization between PAR(2) and PAR(4). PAR(2) also enhanced glycosylation of PAR(4) and activation of PAR(4) signaling. Our results identify a novel regulatory role for PAR(2) in the anterograde traffic of PAR(4). PAR(2) was shown to both facilitate and abrogate protein interactions with PAR(4), impacting upon receptor localization and cell signal transduction. This work is likely to impact markedly upon the understanding of the receptor pharmacology of PAR(4) in normal physiology and disease.

  1. Fuel material neutron crystallography texture and structure determinations (1960); Etudes sur l'evolution des structures cristallines de l'uranium par neutrocristallographie (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Laniesse, J; Englander, M; Meriel, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    {beta} {yields} {alpha} transformation at 333 deg. K of a bulk U alloy containing 1000 ppm chromium. (author) [French] La methode utilisee permet d'obtenir d'une maniere plus rapide et plus statistique que par difraction de rayons X des informations sur la texture d'agregats polycristallins d'uranium-metal et sur les cours de l'evolution de leurs structures crystallines pendant leurs transformations allotropiques. Elle emploie un faisceau neutronique sortant du reacteur EL3 au CEN Saclay, monochromatise a {lambda} = 1,143 A {+-} 0,030 Angstrom; l'axe de ce faisceau rigoureusement collimate, est dirige perpendiculairement a l'axe de fibre de l'echantillon de forme cylindrique et de dimensions optimales. Les neutrons diffuses sont recus dans un compteur BF3 qui peut decrire un cercle centre sur l'echantillon (R = 1,30 m), dans un plan horizontal passant par l'axe du faisceau; de plus, le dispositif de fixation de l'echantillon permet la rotation de celui-ci autour de son axe longitudinal. Le spectre de reference des raies de diffraction neutronique de la phase {alpha} de l'uranium pur est ainsi obtenu a la temperature ordinaire, en utilisant un echantillon pour lequel il est certain qu'il n'existe aucune texture parasite ou residuaire. Il en est de meme pour la phase {beta} d'une solution solide metastable d'uranium contenant la concentration nominale d'impuretes metalliques telles que le Cr ou le Si. Ces deux spectres sont compares aux spectres theoriques ainsi qu'aux spectres de diffraction roentgenographiques. En choisissant ensuite convenablement un certain nombre de ces raies de diffraction, les evaluations d'orientations predominantes eventuelles peuvent etre suivies qualitativement et semi-quantitativement, en fonction des differents traitements mecaniques et/ou thermiques subis simultanement ou non par l'echantillon. De meme en enregistrant d'une maniere continue l'intensite d'une raie mixte judicieusement placee par rapport aux raies des spectres {alpha} et {beta

  2. The collective radio properties of symbiotic stars

    International Nuclear Information System (INIS)

    Seaquist, E.R.; Taylor, A.R.

    1990-01-01

    Radio measurements of symbiotic stars are reported which extend the search for radio emission and provide multifrequency and multiepoch measurements of previously detected stars. The results show no evidence that there are time variations in excess of about 30 percent over a period of several years in the detected stars. The radio flux densities are correlated with brightness in the IR, especially at the longer IR wavelengths where dust emission dominates. It is confirmed that symbiotics with the latest red giant spectral types are the most luminous radio emitters. The D-types are the most radio-luminous. Virtually all detected stars with measurements at more than one frequency exhibit a positive spectral index, consistent with optically thick thermal bremsstrahlung. The binary separation for a number of radio-emitting symbiotics is estimated, and it is found that the distribution of inferred binary separations is dramatically different for IR D-types than for S-types. 37 refs

  3. The Impact of Radio Interference on Future Radio Telescopes

    Science.gov (United States)

    Mitchell, Daniel A.; Robertson, Gordon J.; Sault, Robert J.

    While future radio telescopes will require technological advances from the communications industry interference from sources such as satellites and mobile phones is a serious concern. In addition to the fact that the level of interference is growing constantly the increased capabilities of next generation instruments make them more prone to harmful interference. These facilities must have mechanisms to allow operation in a crowded spectrum. In this report some of the factors which may limit the effectiveness of these mechanisms are investigated. Radio astronomy is unique among other observing wavelengths in that the radiation can be fully sampled at a rate which completely specifies the electromagnetic environment. Knowledge of phases and antennae gain factors affords one the opportunity to attempt to mitigate interference from the astronomical data. At present several interference mitigation techniques have been demonstrated to be extremely effective. However the observational scales of the new facilities will push the techniques to their limits. Processes such as signal decorrelation varying antenna gain and instabilities in the primary beam will have a serious effect on some of the algorithms. In addition the sheer volume of data produced will render some techniques computationally and financially impossible.

  4. Radio emission in peculiar galaxies

    Science.gov (United States)

    Demellorabaca, Dulia F.; Abraham, Zulema

    1990-01-01

    During the last decades a number of surveys of peculiar galaxies have been carried out and accurate positions become available. Since peculiarities are a possible evidence of radio emission (Wright, 1974; Sulentic, 1976; Stocke et al., 1978), the authors selected a sample of 24 peculiar galaxies with optical jet-like features or extensions in different optical catalogues, mainly the Catalogue of Southern Peculiar Galaxies and Associations (Arp and Madore, 1987) and the ESO/Uppsala Survey of the ESO(B) Atlas (Lauberts, 1982) for observation at the radio continuum frequency of 22 GHz. The sample is listed in a table. Sol (1987) studied this sample and concluded that the majority of the jet-like features seem to admit an explanation in terms of interactive galaxies with bridges and/or tails due to tidal effects. Only in a few cases do the jets seem to be possibly linked to some nuclear activity of the host galaxy. The observations were made with the 13.7m-radome enclosed Itapetinga Radiotelescope (HPBW of 4.3 arcmin), in Brazil. The receiver was a 1 GHz d.s.b. super-heterodine mixer operated in total-power mode, with a system temperature of approximately 800 K. The observational technique consisted in scans in right ascention, centralized in the optical position of the galaxy. The amplitude of one scan was 43 arcmin, and its duration time was 20 seconds. The integration time was at least 2 hours (12 ten-minute observations) and the sensibility limit adopted was an antenna temperature greater than 3 times the r.m.s. error of the baseline determination. Virgo A was used as the calibrator source. Three galaxies were detected for the first time as radio sources and four other known galaxies at low frequencies had their flux densities measured at 22 GHz. The results for these sources are presented.

  5. Coping with Radio Frequency Interference

    Science.gov (United States)

    Lewis, B. M.

    2009-01-01

    The radio spectrum is a finite resource, on which humanity makes many demands. And pressure on it is ever increasing with the development of new technology and ideas for radio services. After all, we all benefit from wifi and cell phones. Radio astronomers have a small percentage of the spectrum allocated to them at octave intervals in the metre-centimetre bands, and at important frequencies, such as that of the 21cm line of HI. Signals from other services, as well as from our own poorly-engineered equipment, sometimes contaminate our bands: these signals constitute RFI. These may totally obliterate the astronomical signal, or, in the case of CLOUDSAT, may be capable of completely destroying a receiver, which introduces us to the new possibility of 'destructive interference'. A geo-stationary satellite can block access to a piece of sky from one site. Good equipment design eliminates self-inflicted interference, while physical separation often provides adequate practical mitigation at many frequencies. However, new observatories end up being located in the West Australian desert or Antarctica. In future they may be on the back side of the Moon. But there is no Earth-bound protection via physical separation against satellite signals. Some mitigation can be achieved by frequent data dumps and the excision of RFI, or by real-time detection and blanking of the receiver, or by more sophisticated algoriths. Astronomers of necessity aim to achieve mitigation via coordination, at the local level, and by participating in spectrum management at the national and international levels. This involves them spending a lot of time in Geneva at the International Telegraphic Union protecting their access to spectrum, and access to clean spectrum from the L3 point and the far side of the Moon.

  6. 47 CFR 95.201 - (R/C Rule 1) What is the Radio Control (R/C) Radio Service?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rule 1) What is the Radio Control (R/C...) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Radio Control (R/C) Radio Service General Provisions § 95.201 (R/C Rule 1) What is the Radio Control (R/C) Radio Service? The R/C Service is a private...

  7. A Fast Radio Burst Host Galaxy

    OpenAIRE

    Keane, E. F.; Johnston, S.; Bhandari, S.; Barr, E.; Bhat, N. D. R.; Burgay, M.; Caleb, M.; Flynn, C.; Jameson, A.; Kramer, M.; Petroff, E.; Possenti, A.; van Straten, W.; Bailes, M.; Burke-Spolaor, S.

    2016-01-01

    In recent years, millisecond duration radio signals originating from distant galaxies appear to have been discovered in the so-called Fast Radio Bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity which, in tandem with a redshift measurement, can be used for fundamental physical investigations. While every fast radio burst has a dispersion measurement, none before now have had a redshift measurement, due to the difficulty in...

  8. Flattening and radio emission among elliptical galaxies

    International Nuclear Information System (INIS)

    Disney, M.J.; Sparks, W.B.; Wall, J.V.

    1984-01-01

    In a sample of 132 bright elliptical galaxies it is shown that there is a strong correlation between radio activity and flattening in the sense that radio ellipticals are both apparently and inherently rounder than the average elliptical. Both extended and compact sources are subject to the same correlation. No galaxies with axial ratios below 0.65 are found to be radio emitters. (author)

  9. Radio cobalt in French rivers

    International Nuclear Information System (INIS)

    Lambrechts, A.; Baudin-Jaulent, Y.

    1996-01-01

    The isotopes 58 and 60 of cobalt present in liquid wastes from nuclear plants or from fuel reprocessing plant of Marcoule are fixed in the different compartments of French rivers. The activity levels of radio-cobalt vary according to the sampled compartments nature (bryophyta > immersed plants > sediment > fish). Elsewhere, laboratory experimentations show that the contamination of fish occurs essentially from the water way rather than from food. Cobalt is mainly fixed by kidneys; muscles is no more than 30 % of the total fish activity. (author)

  10. Signal processing for cognitive radios

    CERN Document Server

    Jayaweera, Sudharman K

    2014-01-01

    This book covers power electronics, in depth, by presenting the basic principles and application details, and it can be used both as a textbook and reference book.  Introduces the specific type of CR that has gained the most research attention in recent years: the CR for Dynamic Spectrum Access (DSA). Provides signal processing solutions to each task by relating the tasks to materials covered in Part II. Specialized chapters then discuss specific signal processing algorithms required for DSA and DSS cognitive radios  

  11. The polarization of radio galaxies

    International Nuclear Information System (INIS)

    Jaegers, W.J.

    1986-01-01

    In this thesis radio observations at 0.6 GHz together with matched (convolved) observations at 1.4 GHz of 30 radiosources are described and interpreted. Sources of great interest which are individually discussed are the complex nearby source 3C66B, the source 4C73.48, the narrow edge-darkened double source 3C130 (together with two newly observed narrow-edge-darkened doubles), the galaxies 3C129 and 3C390.3 and the giant quasar 4C34.47. (Auth.)

  12. La radio universitaria se mueve

    OpenAIRE

    Gloria Rodríguez Garay

    2015-01-01

    El reto que plantea la radiodifusión universitaria en México con el intercambio productivo como sistema y procedimiento para optimizar el medio, hace necesaria la concienciación y participación activa de la comunidad universitaria; estudiantil, docente y administrativa, con el fin de valorar la producción radiofónica como elemento fundamental para el desarrollo académico de las mismas instituciones y su vinculación permanente con la sociedad. La radio universitaria cumple funciones de informa...

  13. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1977-01-01

    Identifications are suggested for 53 radio sources from the southern zones of the Parkes 2700-MHz survey, 32 with galaxies, 11 with suggested QSOs and 10 with confirmed QSOs. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar Sky Survey prints. Accurate optical positions have been measured for four of the new identifications and for two previously suggested identifications. A further nine previously suggested QSO identifications have also been confirmed by two-colour photography or spectroscopy. (author)

  14. HF radio systems and circuits

    CERN Document Server

    Sabin, William

    1998-01-01

    A comprehensive reference for the design of high frequency communications systems and equipment. This revised edition is loaded with practical data, much of which cannot be found in other reference books. Its approach to the subject follows the needs of an engineer from system definition and performance requirements down to the individual circuit elements that make up radio transmitters and receivers. The accompanying disk contains updated software on filters, matching networks and receiver analysis. SciTech Publishing also provides many other products related to Communication Systems Design.

  15. Radio Propagation into Modern Buildings

    DEFF Research Database (Denmark)

    Rodriguez Larrad, Ignacio; Nguyen, Huan Cong; Jørgensen, Niels T.K.

    2014-01-01

    Energy-efficient buildings are gaining momentum in order to comply with the new energy regulations. Especially in northern cold countries, thick reinforced walls and energy-efficient windows composed of several layers of glass plus metal coating are becoming the de facto elements in modern building...... constructions. These materials are used in favor of achieving a proper level of thermal isolation, but it has been noticed that they can impact heavily on radio signal propagation. This paper presents a measurement-based analysis of the outdoor-to-indoor attenuation experienced in several modern constructions...

  16. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.

    1976-01-01

    Identifications are suggested for 32 radio sources from the southern zones of the Parkes 2700 MHz survey, 18 with galaxies, one with a confirmed and 12 with possible quasistellar objects, and one with a supernova remnant in the Large Magellanic Cloud. The identifications were made from the ESO IIa-O quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for 10 of the objects and for five previously suggested QSOs. (author)

  17. Meteor trajectory estimation from radio meteor observations

    Science.gov (United States)

    Kákona, J.

    2016-01-01

    Radio meteor observation techniques are generally accepted as meteor counting methods useful mainly for meteor flux detection. Due to the technical progress in radio engineering and electronics a construction of a radio meteor detection network with software defined receivers has become possible. These receivers could be precisely time synchronized and could obtain data which provide us with more information than just the meteor count. We present a technique which is able to compute a meteor trajectory from the data recorded by multiple radio stations.

  18. The other radios: Alternative scenario in Peru

    Directory of Open Access Journals (Sweden)

    Carlos Rivadeneyra-Olcese

    2009-10-01

    Full Text Available Peruvian radio shows a huge diversity in direct proportion to its multiculturality, the same which shows a process full of different influences of social actor which have produced a complex and extremely rich scenario, that is also filled with opportunities and challenges. Beyond the great capital commercial radio are the other radios, small companies, provincial, from church or the mayor or small business owners sons of folkloric melomania, different actors with a passion to establish a new media. The multiple motivations produce a scenario with many types of radio that we wishes to start knowing.

  19. Radio emission of the sun and planets

    CERN Document Server

    Zheleznyakov, V V

    1970-01-01

    International Series of Monographs in Natural Philosophy, Volume 25: Radio Emission of the Sun and Planets presents the origin of the radio emission of the planets. This book examines the outstanding triumphs achieved by radio astronomy of the solar system. Comprised of 10 chapters, this volume begins with an overview of the physical conditions in the upper layers of the Sun, the Moon, and the planets. This text then examines the three characteristics of radio emission, namely, the frequency spectrum, the polarization, and the angular spectrum. Other chapters consider the measurements of the i

  20. Radio systems engineering a tutorial approach

    CERN Document Server

    Santos, Héctor J De Los; Ponte, Juan

    2015-01-01

    This book is intended for readers who already have knowledge of devices and circuits for radio-frequency (RF) and microwave communication and are ready to study the systems engineering-level aspects of modern radio communications systems. The authors provide a general overview of radio systems with their components, focusing on the analog parts of the system and their non-idealities. Based on the physical functionality of the various building blocks of a modern radio system, block parameters are derived, which allows the examination of their influence on the overall system performance. The dis

  1. Computing angle of arrival of radio signals

    Science.gov (United States)

    Borchardt, John J.; Steele, David K.

    2017-11-07

    Various technologies pertaining to computing angle of arrival of radio signals are described. A system that is configured for computing the angle of arrival of a radio signal includes a cylindrical sheath wrapped around a cylindrical object, where the cylindrical sheath acts as a ground plane. The system further includes a plurality of antennas that are positioned about an exterior surface of the cylindrical sheath, and receivers respectively coupled to the antennas. The receivers output measurements pertaining to the radio signal. A processing circuit receives the measurements and computes the angle of arrival of the radio signal based upon the measurements.

  2. Millisecond radio pulsars in globular clusters

    Science.gov (United States)

    Verbunt, Frank; Lewin, Walter H. G.; Van Paradijs, Jan

    1989-01-01

    It is shown that the number of millisecond radio pulsars, in globular clusters, should be larger than 100, applying the standard scenario that all the pulsars descend from low-mass X-ray binaries. Moreover, most of the pulsars are located in a small number of clusters. The prediction that Teran 5 and Liller 1 contain at least about a dozen millisecond radio pulsars each is made. The observations of millisecond radio pulsars in globular clusters to date, in particular the discovery of two millisecond radio pulsars in 47 Tuc, are in agreement with the standard scenario, in which the neutron star is spun up during the mass transfer phase.

  3. The Origin of Powerful Radio Sources

    Science.gov (United States)

    Wilson, A. S.; Colbert, E. J. M.

    1995-05-01

    Radio-loud active galaxies are associated with elliptical or elliptical-like galaxies, many of which appear to be the result of a recent merger. In contrast, radio-quiet active galaxies prefer spiral hosts. Despite the very large difference in radio luminosities between the two classes, their continua and line spectra from infrared through X-ray frequencies are very similar. In this paper, we describe recent developments of our model (Ap. J. 438, 62 1995) in which the radio-loud phenomenon is the result of a merger of two galaxies, with each galaxy nucleus containing a slowly (or non-) rotating supermassive black hole. It is envisaged that the two black holes eventually coalesce. For the small fraction of mergers in which the two holes are both massive and of comparable mass, a rapidly-spinning, high-mass hole results. The spin energy of a rapidly rotating 10(8-9) solar mass hole suffices to provide the ~ 10(60) ergs in relativistic particles and magnetic fields in the most energetic radio sources. Luminous radio-quiet active galaxies contain high-mass, slowly-rotating holes, with the infrared through X-ray emission of both classes being fuelled by accretion as commonly assumed. We discuss constraints on the model from the luminosity functions of radio-loud and radio-quiet galaxies and from the known cosmological evolution of the radio source population; this evolution is assumed to reflect higher galaxy merger rates in the past.

  4. Positron Accumulator Ring (PAR) power supply

    International Nuclear Information System (INIS)

    Fathizadeh, M.

    1995-01-01

    The Positron Accumulator Ring (PAR) consists of 8 dipole magnets connected in series. These magnets are energized via one 12-pulse dc power supply. The power supply consists of four phase controlled half-wave wye group converters. Each of the two half-wave converters are connected through an interphase transformer to obtain a full-wave converter with 120 degrees conduction. The input voltage for these two half-wave converters are 180 degrees apart. The two full-wave converters are connected in parallel through a third interphase transformer. This type of connection of the converters not only provides the required output current, it also improves the input power factor of the power supply. The output of the wye group converters is filtered through a passive L-R-C filter to reduce the ripple content of the output current. At low current values of the power supply the current ripple is high, thus a large filter is needed, which adds to the cost of the power supply, however at high output current levels, the current ripple is less severe. The large size of the filter can be reduced by adding an anti-parallel rectifier diode(D1) to the output of the power supply. A freewheeling diode(D2) is connected before the choke to circulate the current once the power supply is turned off. In order to measure the current in the magnet a high precision, low drift, zero flux current transductor is used. This transductor senses the magnet current which provides a feedback signal to control the gating of the converter's thyristors. A true 14 bit Digital to Analog Converter (DAC) is programmed by the control computer for the required current value, providing a reference for the current regulator. Fast correction of the line transients is provided by a relatively fast voltage loop controlled by a high gain slow response current loop

  5. First-in-human uPAR PET

    DEFF Research Database (Denmark)

    Persson, Morten; Skovgaard, Dorthe; Brandt-Larsen, Malene

    2015-01-01

    A first-in-human clinical trial with Positron Emission Tomography (PET) imaging of the urokinase-type plasminogen activator receptor (uPAR) in patients with breast, prostate and bladder cancer, is described. uPAR is expressed in many types of human cancers and the expression is predictive...... for targeted molecular imaging with PET. The safety, pharmacokinetic, biodistribution profile and radiation dosimetry after a single intravenous dose of (64)Cu-DOTA-AE105 were assessed by serial PET and computed tomography (CT) in 4 prostate, 3 breast and 3 bladder cancer patients. Safety assessment...... of invasion, metastasis and indicates poor prognosis. uPAR PET imaging therefore holds promise to be a new and innovative method for improved cancer diagnosis, staging and individual risk stratification. The uPAR specific peptide AE105 was conjugated to the macrocyclic chelator DOTA and labeled with (64)Cu...

  6. Peptide-Based Optical uPAR Imaging for Surgery

    DEFF Research Database (Denmark)

    Juhl, Karina; Christensen, Anders; Persson, Morten

    2016-01-01

    Near infrared intra-operative optical imaging is an emerging technique with clear implications for improved cancer surgery by enabling a more distinct delineation of the tumor margins during resection. This modality has the potential to increase the number of patients having a curative radical...... tumor resection. In the present study, a new uPAR-targeted fluorescent probe was developed and the in vivo applicability was evaluated in a human xenograft mouse model. Most human carcinomas express high level of uPAR in the tumor-stromal interface of invasive lesions and uPAR is therefore considered...... an ideal target for intra-operative imaging. Conjugation of the flourophor indocyanine green (ICG) to the uPAR agonist (AE105) provides an optical imaging ligand with sufficiently high receptor affinity to allow for a specific receptor targeting in vivo. For in vivo testing, human glioblastoma xenograft...

  7. Contribution de la tomographie par coherence optique au diagnostic ...

    African Journals Online (AJOL)

    Contribution de la tomographie par coherence optique au diagnostic de la neuropathie optique toxique. C.O.A. Abouki, S Alamou, C.R.A. Assavedo, L Odoulami-Yehouessi, I Sounouvou, S Hounnou-Tchabi ...

  8. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids.

    Directory of Open Access Journals (Sweden)

    Flavien Pillet

    Full Text Available Bacterial centromeres-also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA-the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres.

  9. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids.

    Science.gov (United States)

    Pillet, Flavien; Passot, Fanny Marie; Pasta, Franck; Anton Leberre, Véronique; Bouet, Jean-Yves

    2017-01-01

    Bacterial centromeres-also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA-the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi) mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres.

  10. Prise en charge des intoxications par envenimation chez les enfants ...

    African Journals Online (AJOL)

    Les signes cliniques étaient dominés par les douleurs (98%) suivies des hémorragies (73,80%) pour les morsures de serpent, la douleur pour les piqures de scorpion (100%) et les oedèmes pour les piqures d'abeilles (100%). Les cas de morsure de serpent ont été traités par le sérum antivenimeux polyvalent. Conclusion: ...

  11. Intoxication par la paraphényléne-diamine

    African Journals Online (AJOL)

    raoul

    9 mars 2011 ... remède contre la douleur par Averbukh [8], ou contre la constipation par Schemesh [9], mais l´utilisation à des fins autolytique reste toujours prédominante. Le tableau clinique de l´intoxication à ... une anurie ayant nécessité le recours à l´hémodialyse. Ce taux de survenue d´IRA anurique est relativement ...

  12. Croissance epitaxiale de GaAs sur substrats de Ge par epitaxie par faisceaux chimiques

    Science.gov (United States)

    Belanger, Simon

    La situation energetique et les enjeux environnementaux auxquels la societe est confrontee entrainent un interet grandissant pour la production d'electricite a partir de l'energie solaire. Parmi les technologies actuellement disponibles, la filiere du photovoltaique a concentrateur solaire (CPV pour concentrator photovoltaics) possede un rendement superieur et mi potentiel interessant a condition que ses couts de production soient competitifs. La methode d'epitaxie par faisceaux chimiques (CBE pour chemical beam epitaxy) possede plusieurs caracteristiques qui la rendent interessante pour la production a grande echelle de cellules photovoltaiques a jonctions multiples a base de semi-conducteurs III-V. Ce type de cellule possede la meilleure efficacite atteinte a ce jour et est utilise sur les satellites et les systemes photovoltaiques a concentrateur solaire (CPV) les plus efficaces. Une des principales forces de la technique CBE se trouve dans son potentiel d'efficacite d'utilisation des materiaux source qui est superieur a celui de la technique d'epitaxie qui est couramment utilisee pour la production a grande echelle de ces cellules. Ce memoire de maitrise presente les travaux effectues dans le but d'evaluer le potentiel de la technique CBE pour realiser la croissance de couches de GaAs sur des substrats de Ge. Cette croissance constitue la premiere etape de fabrication de nombreux modeles de cellules solaires a haute performance decrites plus haut. La realisation de ce projet a necessite le developpement d'un procede de preparation de surface pour les substrats de germanium, la realisation de nombreuses sceances de croissance epitaxiale et la caracterisation des materiaux obtenus par microscopie optique, microscopie a force atomique (AFM), diffraction des rayons-X a haute resolution (HRXRD), microscopie electronique a transmission (TEM), photoluminescence a basse temperature (LTPL) et spectrometrie de masse des ions secondaires (SIMS). Les experiences ont permis

  13. 47 CFR 2.815 - External radio frequency power amplifiers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false External radio frequency power amplifiers. 2... AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.815 External radio frequency power amplifiers. (a) As used in this part, an external radio frequency power...

  14. Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission

    Science.gov (United States)

    Richards, Gordon T.; Kratzer, R.

    2014-01-01

    We explore the evolution of the fraction of radio loud quasars and the mean radio properties of quasars. Although any quasar has only a ~10% chance of being radio loud and the average quasar has a radio luminosity of ~4x10^30 ergs/s/Hz, these properties are strong functions of not only luminosity, redshift, black hole mass, and accretion rate, but also the strength of the accretion disk wind (as characterized by CIV emission line properties). Quasars with higher optical luminosity and/or lower redshift have a higher than average probability of being radio loud, but their median radio luminosity (relative to optical) is much lower than average. We find that, while radio properties of quasars generally cannot be predicted from their optical properties, objects where one expects a strong radiation line driven wind (based on emission line features) have virtually no chance of being radio loud. The redder quasars are in the optical, the more radio flux (relative to optical) they have; this trend holds even for quasars that are not expected to be significantly dust reddened/extincted in the optical. Finally, we consider the radio properties of quasars in the framework of models which describe the radio loud extrema as being due to particularly high spin resulting from second generation mergers and in the context of star formation at lower levels of radio flux. This work was supported by NSF AAG grant 1108798.

  15. The detectability of radio emission from exoplanets

    Science.gov (United States)

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

    2018-05-01

    Like the magnetised planets in our Solar System, magnetised exoplanets should emit strongly at radio wavelengths. Radio emission directly traces the planetary magnetic fields and radio detections can place constraints on the physical parameters of these features. Large comparative studies of predicted radio emission characteristics for the known population of exoplanets help to identify what physical parameters could be key for producing bright, observable radio emission. Since the last comparative study, many thousands of exoplanets have been discovered. We report new estimates for the radio flux densities and maximum emission frequencies for the current population of known exoplanets orbiting pre-main sequence and main-sequence stars with spectral types F-M. The set of exoplanets predicted to produce observable radio emission are Hot Jupiters orbiting young stars. The youth of these system predicts strong stellar magnetic fields and/or dense winds, which are key for producing bright, observable radio emission. We use a new all-sky circular polarisation Murchison Widefield Array survey to place sensitive limits on 200 MHz emission from exoplanets, with 3σ values ranging from 4.0 - 45.0 mJy. Using a targeted Giant Metre Wave Radio Telescope observing campaign, we also report a 3σ upper limit of 4.5 mJy on the radio emission from V830 Tau b, the first Hot Jupiter to be discovered orbiting a pre-main sequence star. Our limit is the first to be reported for the low-frequency radio emission from this source.

  16. SURVEY PERILAKU MENDENGARKAN RADIO DI JAKARTA

    Directory of Open Access Journals (Sweden)

    Siti Dewi Sri Ratna Sari

    2016-05-01

    Full Text Available This research is to find out the profile of radio broadcasting’s content in Jakarta and to look for measured data as the parameter to assess radio broadcasting programs and the radio listeners profile in DKI Jakarta. The research methodology is survey with 1000 respondents as the sample with 2.24% margin of error and 95% credibility level. The sampling method used is Multistage Random Sampling from 5 out of 6 DKI Jakarta Province areas, except Thousand Islands Regency. Data collection technique used is face to face personal interview by giving gift to the respondents. Research result describes the profile of radio listeners is middle class productive age working men and women whose prime reason listening to radio is music as their pastime. Respondents are categorized as medium listeners with 1.87 hour as their average of listening to radio. Nevertheless, the prime time is covering the whole day both while they are listening at home and while they are mobile. Research found that respondents are already satisfied by the radio programs in Jakarta. The competition of radio stations in Jakarta based on their listeners is Gen FM at the top with 44.6%, followed by Bens Radio, Elshinta, I-Radio, Prambors, CBB, and so on. An interesting finding is that radio’s function to deliver social communication is fulfilled by placing religious speech and information as the second and the third most preferable programs with 9.8% and 8.0% below music program.   Penelitian ini bertujuan untuk mengetahui profil isi siaran radio yang selama ini bersiaran di Jakarta sekaligus mencari data terukur sebagai parameter untuk melakukan penilaian terhadap program isi siaran radio, termasuk pola mendengarkan radio pendengar radio seperti durasi dan tempat di provinsi DKI Jakarta. Metode penelitian berupa survei dengan sampel yang diambil sebanyak 1000 responden, margin of error 2.24% dan tingkat kepercayaan 95%. Metode pengambilan sampel dalam penelitian ini adalah dengan

  17. Serum suPAR in patients with FSGS: trash or treasure?

    NARCIS (Netherlands)

    Maas, R.J.H.; Deegens, J.K.J.; Wetzels, J.F.M.

    2013-01-01

    The urokinase-type plasminogen activator receptor (uPAR) has important functions in cell migration. uPAR can be shed from the cell membrane resulting in soluble uPAR (suPAR). Further cleavage gives rise to shorter fragments with largely unknown functions. Recent studies have demonstrated that both

  18. The Giant Radio Array for Neutrino Detection

    DEFF Research Database (Denmark)

    Martineau-Huynh, Olivier; Bustamante, Mauricio; Carvalho, Washington

    2017-01-01

    The Giant Radio Array for Neutrino Detection (GRAND) is a planned array of ~200 000 radio antennas deployed over ~200 000 km2 in a mountainous site. It aims primarly at detecting high-energy neutrinos via the observation of extensive air showers induced by the decay in the atmosphere of taus...

  19. Orbiting low frequency array for radio astronomy

    NARCIS (Netherlands)

    Rajan, Rai Thilak; Rajan, Raj; Engelen, Steven; Bentum, Marinus Jan; Verhoeven, Chris

    2011-01-01

    Recently new and interesting science drivers have emerged for very low frequency radio astronomy from 0.3 MHz to 30 MHz. However Earth bound radio observations at these wavelengths are severely hampered by ionospheric distortions, man made interference, solar flares and even complete reflection

  20. 50 CFR 300.37 - Radio monitoring.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Radio monitoring. 300.37 Section 300.37 Wildlife and Fisheries INTERNATIONAL FISHING AND RELATED ACTIVITIES INTERNATIONAL FISHERIES REGULATIONS South Pacific Tuna Fisheries § 300.37 Radio monitoring. The international distress frequency, 2.182 mHz...

  1. Radio frequency system for nuclear fusion

    International Nuclear Information System (INIS)

    Kozeki, Shoichiro; Sagawa, Norimoto; Takizawa, Teruhiro

    1987-01-01

    The importance of radio frequency waves has been increasing in the area of nuclear fusion since they are indispensable for heating of plasma, etc. This report outlines radio frequency techniques used for nuclear fusion and describes the development of radio frequency systems (radio frequency plasma heating system and current drive system). Presently, in-depth studies are underway at various research institutes to achieve plasma heating by injection of radio frequency electric power. Three ranges of frequencies, ICRF (ion cyclotron range of frequency), LHRF (lower hybrid range of frequency) and ECRF (electron cyclotron range of frequency), are considered promissing for radio frequency heating. Candidate waves for plasma current driving include ECW (electron cyclotron wave), LHW (lower hybrid wave), MSW (magnetic sound wave), ICW (ion cyclotron wave) with minority component, and FW (fast wave). FW is the greatest in terms of current drive efficiency. In general, a radio frequency system for nuclear fusion consists of a radio frequency power source, transmission/matching circuit component and plasma connection component. (Nogami, K.)

  2. Basic radio interferometry for future lunar missions

    NARCIS (Netherlands)

    Aminaei, Amin; Klein Wolt, Marc; Chen, Linjie; Bronzwaer, Thomas; Pourshaghaghi, Hamid Reza; Bentum, Marinus Jan; Falcke, Heino

    2014-01-01

    In light of presently considered lunar missions, we investigate the feasibility of the basic radio interferometry (RIF) for lunar missions. We discuss the deployment of two-element radio interferometer on the Moon surface. With the first antenna element is envisaged to be placed on the lunar lander,

  3. 14 CFR 99.9 - Radio requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Radio requirements. 99.9 Section 99.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A...

  4. 78 FR 23150 - Commercial Radio Operators

    Science.gov (United States)

    2013-04-18

    ...'s privatized ship radio inspection program. * * * * * 0 3. Section 0.131 is amended by revising... this chapter), and the Commission's privatized ship radio inspection program (part 80 of this chapter... inspection to ships in accordance with applicable provisions of the Communications Act, the Safety Convention...

  5. 47 CFR 32.2231 - Radio systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Radio systems. 32.2231 Section 32.2231 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a...

  6. Adaptive OFDM System Design For Cognitive Radio

    NARCIS (Netherlands)

    Zhang, Q.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

    2006-01-01

    Recently, Cognitive Radio has been proposed as a promising technology to improve spectrum utilization. A highly flexible OFDM system is considered to be a good candidate for the Cognitive Radio baseband processing where individual carriers can be switched off for frequencies occupied by a licensed

  7. Ionospheric Caustics in Solar Radio Observations

    Science.gov (United States)

    Koval, A.; Chen, Y.; Stanislavsky, A.

    2016-12-01

    The Earth ionosphere possesses by natural focusing and defocusing effects on radio waves due to presence of variable ionospheric irregularities which could act like convergent and divergent lenses on incident radiation. In particular, the focusing of emission from the Sun was firstly detected on the Nançay Decameter Array dynamic spectra in the 1980s. On time-frequency spectrograms the intensity variations form specific structures different from well-known solar radio bursts and clearly distinguishing on a background of solar radiation. Such structures have been identified as ionospheric caustics (ICs) and considered to be the result of radio waves refraction on medium scale travelling ionospheric disturbances (MSTIDs). Although nowadays the ICs are registered by different radio observatories due to augmentation of low-frequency radio telescopes, the most recent papers devoted to ICs in solar radio records date back to the 1980s. In this study, we revisit the ICs issue with some new results by conducting a statistical analysis of occurrence rate of ICs in solar dynamic spectra in meter-decameter wavelength range for long continuous period (15 years). The seasonal variations in ICs appearance have been found for the first time. Besides, we report the possible solar cycle dependence of ICs emergence. The radio waves propagation in the ionosphere comprising MSTIDs will be considered. The present research renews the subject of ICs in the low-frequency solar radio astronomy after about 35-year letup.

  8. Mars' radio spectrum and the flying dust.

    NARCIS (Netherlands)

    Roos-Serote, M.; Stam, D.M.; Fender, R.P.

    2004-01-01

    Mars' radio spectrum at centimeter wavelengths is produced by thermal radiation from the surface and sub-surface. Observations at 2.8 cm made in the 1975 and 1978 show variations of its radio brightness as a function of longitude on the planet (Doherty et al. , ApJ 233, 1979). In addition, an

  9. Physical processes in extragalactic radio sources

    NARCIS (Netherlands)

    Carilli, CL; Perley, R; Harris, DE; Barthel, PD

    This paper summarizes extensive observational studies of the closest ultraluminous radio galaxy Cygnus A. These data are used to test jet theory for powering the double-lobed radio emitting structures. Issues addressed include: (i) jet stability, confinement, composition, and velocity, (ii) the

  10. Radio monitoring problems, methods, and equipment

    CERN Document Server

    Rembovsky, Anatoly; Kozmin, Vladimir; Smolskiy, Sergey

    2009-01-01

    Offers a unified approach to fundamental aspects of Automated Radio Monitoring (ARM). This book discusses the development, modeling, design, and manufacture of ARM systems. It provides classification and descriptions of modern high-efficient hardware-software ARM equipment, including the equipment for detection and radio direction-finding.

  11. A Radio-Controlled Car Challenge

    Science.gov (United States)

    Roman, Harry T.

    2010-01-01

    Watching a radio-controlled car zip along a sidewalk or street has become a common sight. Within this toy are the basic ingredients of a mobile robot, used by industry for a variety of important and potentially dangerous tasks. In this challenge, students consider modifying an of-the-shelf, radio-controlled car, adapting it for a robotic task.

  12. Determination of the exchange capacity of soils using radio-strontium; Determination de la capacite d'echange des sols au moyen du radio-strontium

    Energy Technology Data Exchange (ETDEWEB)

    Grauby, A; Saas, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In order to improve the technique and in particular to reduce the time required for measuring the exchange capacity of soils, the authors have developed a rapid measurement method based on the use of radio-active tracers. The element chosen for showing the occurrence of exchangeable bases is radio-strontium; it can displace the ions Ca{sup ++}, Mg{sup ++}, Na{sup ++}, K{sup +} from the soil. The use of a de-sorbent, barium chloride, makes it possible to recover the strontium fixed. A comparison of the results obtained using the two methods appears to be very satisfactory. The conventional method requires from 1 1/2 to 2 days - the radio-strontium method requires only 3 hours with the possibility also of carrying out large series of measurements. (authors) [French] Pour ameliorer la technique et surtout reduire le temps de manipulation que necessite la mesure de la capacite d'echange des sols, les auteurs ont mis au point une methode de mesure rapide qui fait appel aux traceurs radioactifs. C'est le radio-strontium qui a ete choisi pour la mise en evidence des bases echangeables. Il permet de deplacer les ions Ca{sup ++}, Mg{sup ++}, Na{sup ++}, K{sup +} du sol. Un desorbant, le chlorure de baryum, permet de recuperer la quantite du strontium fixe. La comparaison des resultats obtenus par les deux methodes semble tres satisfaisante. La methode classique necessite 1 jour et demi a 2 jours - la methode radiostrontium exige seulement 3 heures avec la possibilite de grandes series. (auteurs)

  13. Radio Interoperability: There Is More to It Than Hardware

    National Research Council Canada - National Science Library

    Hutchins, Susan G; Timmons, Ronald P

    2007-01-01

    Radio Interoperability: The Problem *Superfluous radio transmissions contribute to auditory overload of first responders -Obscure development of an accurate operational picture for all involved -Radio spectrum is a limited commodity once...

  14. VHF spectrum monitoring using Meraka cognitive radio platform

    CSIR Research Space (South Africa)

    Aderonmu, AI

    2012-11-01

    Full Text Available discuss the Meraka Cognitive Radio Platform (MCRP) developed using the second version of the Universal Serial Radio Peripheral (USRP2) hardware and the GNU Radio software. We also discussed how the spectrum monitoring system is being implemented...

  15. Une terreur par l’image

    Directory of Open Access Journals (Sweden)

    Annie DULONG

    2011-09-01

    Full Text Available Si d’autres événements — Hiroshima, la découverte des camps de concentration, la chute du mur de Berlin — ont, au cours du XXe siècle, marqué suffisamment l’imaginaire pour trouver leur réponse dans des œuvres d’art, le 11 septembre 2001 pose la question de la fictionnalisation autrement : il ne s’agit plus tant de combler les manques de la représentation, liés à l’absence d’images ou au délai dans leur dévoilement, mais bien de composer avec l’omniprésence d’une représentation martelée à la télévision et sur Internet. Que cette représentation soit partielle, tronquée et qu’il lui manque la présence des corps, ces grands absents des photographies et des images tournées par les journalistes, ne change rien au fait que c’est avec le trop-plein que les artistes doivent maintenant négocier.Cet article s’intéresse aux romans qui traitent l’événement de front au lieu de l’aborder sur un mode mineur, et a pour objectif de tracer un portrait de la représentation des médias dans les romans du 11 septembre 2001. Ces romans, outre le fait qu’ils traitent des événements de New York, ont comme point commun un personnage, ou décor : les médias, représentés par la télévision, l’Internet, les photographies de presse, interviennent dans les récits d’une manière significative et témoignent de la force brute des images. À travers une étude de certains des mécanismes à l’œuvre dans The Writing on the Wall (Lynne Sharon Schwartz, Extremely Loud and Incredibly Close (Jonathan Safran Foer, Falling Man (Don DeLillo et A Disorder Peculiar to the Country (Ken Kalfus, il s’agira de proposer des réponses à ces quelques questions : quel rôle les médias jouent-ils, et comment participent-ils au récit ? Quelle pression les images exercent-elles sur les personnages ? Que révèlent les personnages enfants dans leur rapport aux médias ? Quelle critique, finalement, les romans

  16. Cognitive Radio RF: Overview and Challenges

    Directory of Open Access Journals (Sweden)

    Van Tam Nguyen

    2012-01-01

    Full Text Available Cognitive radio system (CRS is a radio system which is aware of its operational and geographical environment, established policies, and its internal state. It is able to dynamically and autonomously adapt its operational parameters and protocols and to learn from its previous experience. Based on software-defined radio (SDR, CRS provides additional flexibility and offers improved efficiency to overall spectrum use. CRS is a disruptive technology targeting very high spectral efficiency. This paper presents an overview and challenges of CRS with focus on radio frequency (RF section. We summarize the status of the related regulation and standardization activities which are very important for the success of any emerging technology. We point out some key research challenges, especially implementation challenges of cognitive radio (CR. A particular focus is on RF front-end, transceiver, and analog-to-digital and digital-to-analog interfaces which are still a key bottleneck in CRS development.

  17. Optical spectra and radio properties of quasars

    International Nuclear Information System (INIS)

    Wills, B.J.

    1982-01-01

    Using high quality spectrophotometric scans obtained at the McDonald Observatory, and data from the literature the author shows that, for quasars, the relative strength of optical Fe II emission (the broad blended feature lambda4570) may be roughly inversely proportional to line widths (full width at half maximum, FWHM). A similar relation between the relative intensity of the UV Fe II blend between 2300 and 2600 A (the lambda2500 feature) and the widths of Mg II and Hβ is shown. She distinguishes between compact and extended radio sources and includes radio quiet quasars, Seyfert 1 galaxies and BLRG's. The quasars associated with extended radio sources have the broadest emission lines and the weakest Fe II, falling close to the region occupied by BLRG's which also have extended radio structure. Those quasars with strong Fe II and compact radio structure are most similar to the Seyfert 1 galaxies. (Auth.)

  18. The crisis of the radio producing

    Directory of Open Access Journals (Sweden)

    Dr. Raúl Garcés

    2007-09-01

    Full Text Available In a media world highly influenced by new technologies revolution and the increasing impact of television, speeches on radio are frequently polarized: in one side, some scholars argue radio belongs to the past and it is no longer able of attracting younger audiences. In the other, lay those who predict long life to radio as a source of alternative and communitarian communication experiences. The author reviews the arguments that sustain both perspectives and emphasizes the need of renovating radio producing with audacious and creative formulas. At the same time, he discusses some of the challenges Cuban radio has ahead to attract new audiences, when television and printed press are recovering from the economic crack the Island suffered after Eastern European socialism disappeared.

  19. The statistics of radio emission from quasars

    International Nuclear Information System (INIS)

    Peacock, J.A.; Miller, L.; Longair, M.S.; Edinburgh Univ.

    1986-01-01

    The radio properties of quasars have traditionally been discussed in terms of the radio-to-optical flux-density ratio R, implying a correlation between emission in these wavebands. It is here shown that, for bright quasars, this apparent correlation is largely due to an abrupt change in the radio properties of the quasar population near absolute magnitude Msub(B)=-24. It is suggested that this change in due to the existence of two classes of quasar with differing host galaxies: a proportion of quasars brighter than Msub(B)approx.=-24 lie in elliptical galaxies and thus generate powerful radio sources, while elliptical galaxies with weaker nuclear quasar components are classified as N-galaxies rather than quasars; quasars fainter than Msub(B)approx.=-24 lie in spiral galaxies and thus are high-luminosity analogues of radio-quiet Seyfert galaxies. (author)

  20. Hybrid cognitive engine for radio systems adaptation

    KAUST Repository

    Alqerm, Ismail

    2017-07-20

    Network efficiency and proper utilization of its resources are essential requirements to operate wireless networks in an optimal fashion. Cognitive radio aims to fulfill these requirements by exploiting artificial intelligence techniques to create an entity called cognitive engine. Cognitive engine exploits awareness about the surrounding radio environment to optimize the use of radio resources and adapt relevant transmission parameters. In this paper, we propose a hybrid cognitive engine that employs Case Based Reasoning (CBR) and Decision Trees (DTs) to perform radio adaptation in multi-carriers wireless networks. The engine complexity is reduced by employing DTs to improve the indexing methodology used in CBR cases retrieval. The performance of our hybrid engine is validated using software defined radios implementation and simulation in multi-carrier environment. The system throughput, signal to noise and interference ratio, and packet error rate are obtained and compared with other schemes in different scenarios.

  1. Radio Frequency Interference: The Study of Rain Effect on Radio Signal Attenuation

    International Nuclear Information System (INIS)

    Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Atiq Wahidah Azlan; Zainol Abidin Ibrahim

    2015-01-01

    The intensity of radio waves received by radio telescopes is always not subject to human control. In the millimetre band, the propagation of the electromagnetic waves is severely affected by rain rate, dust particle size and drop size in the terms of attenuation, noise and depolarization. At the frequency above 10 GHz, the absorption and scattering by rain cause a reduction in the transmitted signal amplitude which will lead to the reducing of the availability, reliability and performance on the communications link. In this study, the rain effect on radio signal has been investigated. Spectrum analyzer and weather stations were used to obtain the RFI level and rain rate data respectively. The radio frequency interference (RFI) pattern due to rain factor was determined. This will benefit radio astronomer in managing sites for radio observation for radio astronomy purposes. (author)

  2. Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources

    DEFF Research Database (Denmark)

    Aatrokoski, J.; Lähteenmäki, A.; Lavonen, N.

    2011-01-01

    Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857 GHz......, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase...... of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data...

  3. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned

  4. On the solution of a few problems of multiple scattering by Monte Carlo method; Sur la solution de quelques problemes de diffusions multiples par la methode de Monte-Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Bluet, J C [Commissariat a l' Energie Atomique, Cadarache (France)

    1966-02-01

    isotrope. 3.- La particule ne perd pas d'energie au cours des collisions successives. Ces hypotheses sont justifiees par les materiaux et les gammes d'energie etudies. 1er probleme: une cible de sodium de geometrie donnee est soumise a un flux de neutrons. Certains noyaux sont actives. L'activation est ensuite mesuree par un cristal au iodure de sodium. La methode de Monte-Carlo permet de calculer la distribution des noyaux actives dans l'echantillon en tenant compte des diffusions et l'efficacite du compteur. Un disque en verre au Li{sup 6} est soumis a un flux de neutrons perpendiculaire a ses faces planes. Si l'epaisseur du verre n'est pas negligeable devant le libre parcours de diffusion {lambda}, il y aura des collisions et le parcours moyen e' d'un neutron dans le verre sera different de l'epaisseur. e' est calcule par la methode de Monte-Carlo. On en tire une correction relative d'efficacite egale a (e' - e)/ e. 3eme probleme: un detecteur de neutrons est place au fond d'un cylindre entoure d'eau. Un flux de neutrons provient d'une source placee sur l'axe, en avant de la protection; on calcule le rapport du nombre de neutrons allant directement de la source au detecteur au nombre de neutrons faisant un trajet non direct avec des collisions dans l'eau. Pour les trois problemes on donne les resultats trouves pour quelques cas concrets tels qu'ils se sont poses experimentalement, et des courbes plus generales ou on utilise des variables reduites comme le rapport libre parcours/dimension geometrique ou son inverse. On donne egalement les listes d'instructions des programmes, avec les organigrammes complets et les tableaux de correspondances entre symboles. (auteur)

  5. Program on Resorbable Radio Devices

    Science.gov (United States)

    2014-05-05

    water   electrolysis  to give out gas ‐. Gas pushes  water  out of the weak point of the  water   tank, e.g., a pre‐made hole with/without covering with  a thin...are capable of complete dissolution in water . The views, opinions and/or findings contained in this report are those of the author(s) and should not...device designs for radio enabled electronics that are capable of complete dissolution in water . (a) Papers published in peer-reviewed journals (N/A

  6. VLSI Technology for Cognitive Radio

    Science.gov (United States)

    VIJAYALAKSHMI, B.; SIDDAIAH, P.

    2017-08-01

    One of the most challenging tasks of cognitive radio is the efficiency in the spectrum sensing scheme to overcome the spectrum scarcity problem. The popular and widely used spectrum sensing technique is the energy detection scheme as it is very simple and doesn’t require any previous information related to the signal. We propose one such approach which is an optimised spectrum sensing scheme with reduced filter structure. The optimisation is done in terms of area and power performance of the spectrum. The simulations of the VLSI structure of the optimised flexible spectrum is done using verilog coding by using the XILINX ISE software. Our method produces performance with 13% reduction in area and 66% reduction in power consumption in comparison to the flexible spectrum sensing scheme. All the results are tabulated and comparisons are made. A new scheme for optimised and effective spectrum sensing opens up with our model.

  7. Radio Frequency Energy Harvesting Sources

    Directory of Open Access Journals (Sweden)

    Action NECHIBVUTE

    2017-12-01

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

  8. Integral luminosities of radio pulsars

    Science.gov (United States)

    Malov, I.; Malov, O.

    The integral radio luminosities L for 311 normal pulsars and for 27 ones with the rotation period Pfalls for fast ones. The mean values of K are -3.73 and -4.85 for normal and fast pulsars, respectively. There are no changes of L with the kinematic age T = z/V, where z is the pulsar height over the Galactic plane and V = 300 km/s is its mean velocity. The correlation between L and the rate of the rotation energy losses E is detected for both pulsar groups under consideration. It is shown that L= A E^(1/3) for the whole sample. The total number of pulsars in the Galaxy and their birth rate are in agreement with data on the rate of supernova explosions.

  9. Can Radio Telescopes Find Axions?

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    axions. Now scientists Katharine Kelley and Peter Quinn at ICRAR, University of Western Australia, have explored how we might use next-generation radio telescopes to search for photons that were created by axions interacting with the magnetic fields of our galaxy.Hope for Next-Gen TelescopesPotential axion coupling strengths vs. mass (click for a closer look). The axion mass is thought to lie between a eV and a meV; two theoretical models are shown with dashed lines. The plot shows the sensitivity of the upcoming SKA and its precursors, ASKAP and MEERKAT. [KelleyQuinn 2017]By using a simple galactic halo model and reasonable assumptions for the central galactic magnetic field even taking into account the time dependence of the field Kelley and Quinn estimate the radio-frequency power density that we would observe at Earth from axions being converted to photons within the Milky Ways magnetic field.The authors then compare this signature to the detection capabilities of upcoming radio telescope arrays. They show that the upcoming Square Kilometer Array and its precursors should have the capability to detect signs of axions across large parts of parameter space.Kelley and Quinn conclude that theres good cause for optimism about future radio telescopes ability to detect axions. And if we did succeed in making a detection, it would be a triumph for both particle physics and astrophysics, finally providing an explanation for the universes dark matter.CitationKatharine Kelley and P. J. Quinn 2017 ApJL 845 L4. doi:10.3847/2041-8213/aa808d

  10. Low-Level {beta} and {gamma} Counting in the Region 0-10 Disintegrations Per Minute; Comptage {beta} et {gamma} d'echantillons de faible activite (0 a 10 desintegrations par minute); Izmerenie {beta}- i {gamma}-izlucheniya maloj moshchnosti (0-10 raspadov v minutu); Recuento {beta} y {gamma} de muestras de baja actividad (0 a 10 desintegraciones por minuto)

    Energy Technology Data Exchange (ETDEWEB)

    Manov, George G [Tracerlab Inc. (United States)

    1960-06-15

    niveaux de radioactivite de l'ordre de 0 a 10 desintegrations par minute devient de plus en plus utile dans la normalisation des radionuclides de meme que dans d'autres domaines scientifiques, tels que la geologie et la medicine. Ainsi le comptage de faible intensites est souvent necessaire en biologie et dans l'emploi des indicateurs, surtout lorsque l'emploi d'un niveau de rayonnement plus eleve modifierait le deroulement du mecanisme ou du processus etudie. Ces mesures portent souvent sur des echantillons ayant une activite de l% seulement de l'activite de fond normale (sans ecran). Dans d'autres cas, il faut tenir compte en outre du fait que le radionuclide a une periode tres courte. Il y a trois manieres generales d'augmenter la precision des mesures de faibles intensites: efficacite plus grand des compteurs, diminution des correc- tions necessitees par l'activite de fond et emploi de circuits electroniques plus stables et plus silencieux. Le memoire decrit des essais compares qui font ressortir les avantages relatifs que presentent trois types differents de compteurs d'anticoincidence s pour la reduction de l'activite de fond: a) compteurs 'champignons'; b) compteurs annulaires; c) domes en matiere plastique a scintillations. Il devient de plus en plus difficile d'obtenir des matieres non actives pour la construction des compteurs. L'auteur donne des indications sur la gamme d'activite des matieres que l'on peut se procurer dans le commerce. Le stockage de ces matieres, qui doivent de preference etre d'avant-guerre, devient de plus en plus necessaire. La stabilite du circuit electronique est indispensable au comptage de faible intensite, afin surtout d'eviter les impulsions parasites. Le memoire decrit un dispositif dans lequel des impulsions lentes sont mesurees, puis introduites dans l'appareillage electronique; elles passent ensuite par l'amplificateur et sont enfin defalquees du chiffre brut indique par le numerateur. D'une maniere generale, les circuits a

  11. The impact of a pilot water metering project in an Indian city on users’ perception of the public water supply Impact pédagogique de l’introduction de compteurs sur les utilisateurs du service d’eau public dans une ville indienne El impacto didáctico de la introducción de medición sobre los usuarios del servicio de abastecimiento de agua público en una ciudad en India

    Directory of Open Access Journals (Sweden)

    A. Amiraly

    2011-06-01

    Full Text Available Purpose – This article concerns a developmental experience in the water sector, namely the introduction of water metering in an Indian city, in the framework of a French water company’s technical assistance to the local public water authority.  We address the impact of the introduction of the water meter, an object that crystallizes a symbolic part of the management model of the French company, on the local water supply context and socio-political environment, focusing in particular on how trust between the users and the service providers is reconfigured.Methodology – The methodology consisted of an exploratory field survey with 37 households in the pilot water metering area.Findings – The water meter is an artefact highlighting users' perception of water and society.  The user reinterprets its function, mainly perceiving it as a tool to monitor the consumption of water, dissociated from the dimension of payment. As soon as the issue of payment based on consumption comes into the picture, then the trust the user has developed in the private foreign company is displaced towards the public authority.Objet – Cet article porte sur une expérience comportementale dans le secteur de l’eau. Dans le cadre d'une mission visant à fournir une assistance technique à une compagnie des eaux publique locale, une société de distribution d’eau française a mis en place des compteurs d’eau dans une ville indienne. L’aspect principal de cette expérience a porté sur la transposition du compteur d’eau, objet qui symbolise le modèle de gestion de l’entreprise française, dans le contexte local d’alimentation en eau et l'environnement socio-politique indien. Nous avons examiné l’impact de cette introduction en nous intéressant plus particulièrement à la modification de la relation de confiance entre les utilisateurs et les fournisseurs de service.Méthodologie – Un sondage qualitatif sur le terrain portant sur 37 foyers dans la

  12. Par Pond vegetation status Summer 1995 -- September survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-09-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  13. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  14. Grote Reber, Radio Astronomy Pioneer, Dies

    Science.gov (United States)

    2002-12-01

    Grote Reber, one of the earliest pioneers of radio astronomy, died in Tasmania on December 20, just two days shy of his 91st birthday. Reber was the first person to build a radio telescope dedicated to astronomy, opening up a whole new "window" on the Universe that eventually produced such landmark discoveries as quasars, pulsars and the remnant "afterglow" of the Big Bang. His self- financed experiments laid the foundation for today's advanced radio-astronomy facilities. Grote Reber Grote Reber NRAO/AUI photo "Radio astronomy has changed profoundly our understanding of the Universe and has earned the Nobel Prize for several major contributions. All radio astronomers who have followed him owe Grote Reber a deep debt for his pioneering work," said Dr. Fred Lo, director of the National Radio Astronomy Observatory (NRAO). "Reber was the first to systematically study the sky by observing something other than visible light. This gave astronomy a whole new view of the Universe. The continuing importance of new ways of looking at the Universe is emphasized by this year's Nobel Prizes in physics, which recognized scientists who pioneered X-ray and neutrino observations," Lo added. Reber was a radio engineer and avid amateur "ham" radio operator in Wheaton, Illinois, in the 1930s when he read about Karl Jansky's 1932 discovery of natural radio emissions coming from outer space. As an amateur operator, Reber had won awards and communicated with other amateurs around the world, and later wrote that he had concluded "there were no more worlds to conquer" in radio. Learning of Jansky's discovery gave Reber a whole new challenge that he attacked with vigor. Analyzing the problem as an engineer, Reber concluded that what he needed was a parabolic-dish antenna, something quite uncommon in the 1930s. In 1937, using his own funds, he constructed a 31.4-foot-diameter dish antenna in his back yard. The strange contraption attracted curious attention from his neighbors and became

  15. Radio Flares from Gamma-ray Bursts

    Science.gov (United States)

    Kopač, D.; Mundell, C. G.; Kobayashi, S.; Virgili, F. J.; Harrison, R.; Japelj, J.; Guidorzi, C.; Melandri, A.; Gomboc, A.

    2015-06-01

    We present predictions of centimeter and millimeter radio emission from reverse shocks (RSs) in the early afterglows of gamma-ray bursts (GRBs) with the goal of determining their detectability with current and future radio facilities. Using a range of GRB properties, such as peak optical brightness and time, isotropic equivalent gamma-ray energy, and redshift, we simulate radio light curves in a framework generalized for any circumburst medium structure and including a parameterization of the shell thickness regime that is more realistic than the simple assumption of thick- or thin-shell approximations. Building on earlier work by Mundell et al. and Melandri et al. in which the typical frequency of the RS was suggested to lie at radio rather than optical wavelengths at early times, we show that the brightest and most distinct RS radio signatures are detectable up to 0.1-1 day after the burst, emphasizing the need for rapid radio follow-up. Detection is easier for bursts with later optical peaks, high isotropic energies, lower circumburst medium densities, and at observing frequencies that are less prone to synchrotron self-absorption effects—typically above a few GHz. Given recent detections of polarized prompt gamma-ray and optical RS emission, we suggest that detection of polarized radio/millimeter emission will unambiguously confirm the presence of low-frequency RSs at early time.

  16. RADIO FLARES FROM GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Kopač, D.; Mundell, C. G.; Kobayashi, S.; Virgili, F. J.; Harrison, R.; Japelj, J.; Gomboc, A.; Guidorzi, C.; Melandri, A.

    2015-01-01

    We present predictions of centimeter and millimeter radio emission from reverse shocks (RSs) in the early afterglows of gamma-ray bursts (GRBs) with the goal of determining their detectability with current and future radio facilities. Using a range of GRB properties, such as peak optical brightness and time, isotropic equivalent gamma-ray energy, and redshift, we simulate radio light curves in a framework generalized for any circumburst medium structure and including a parameterization of the shell thickness regime that is more realistic than the simple assumption of thick- or thin-shell approximations. Building on earlier work by Mundell et al. and Melandri et al. in which the typical frequency of the RS was suggested to lie at radio rather than optical wavelengths at early times, we show that the brightest and most distinct RS radio signatures are detectable up to 0.1–1 day after the burst, emphasizing the need for rapid radio follow-up. Detection is easier for bursts with later optical peaks, high isotropic energies, lower circumburst medium densities, and at observing frequencies that are less prone to synchrotron self-absorption effects—typically above a few GHz. Given recent detections of polarized prompt gamma-ray and optical RS emission, we suggest that detection of polarized radio/millimeter emission will unambiguously confirm the presence of low-frequency RSs at early time

  17. Amateur Planetary Radio Data Archived for Science and Education: Radio Jove

    Science.gov (United States)

    Thieman, J.; Cecconi, B.; Sky, J.; Garcia, L. N.; King, T. A.; Higgins, C. A.; Fung, S. F.

    2015-12-01

    The Radio Jove Project is a hands-on educational activity in which students, teachers, and the general public build simple radio telescopes, usually from a kit, to observe single frequency decameter wavelength radio emissions from Jupiter, the Sun, the galaxy, and the Earth usually with simple dipole antennas. Some of the amateur observers have upgraded their receivers to spectrographs and their antennas have become more sophisticated as well. The data records compare favorably to more sophisticated professional radio telescopes such as the Long Wavelength Array (LWA) and the Nancay Decametric Array. Since these data are often carefully calibrated and recorded around the clock in widely scattered locations they represent a valuable database useful not only to amateur radio astronomers but to the professional science community as well. Some interesting phenomena have been noted in the data that are of interest to the professionals familiar with such records. The continuous monitoring of radio emissions from Jupiter could serve as useful "ground truth" data during the coming Juno mission's radio observations of Jupiter. Radio Jove has long maintained an archive for thousands of Radio Jove observations, but the database was intended for use by the Radio Jove participants only. Now, increased scientific interest in the use of these data has resulted in several proposals to translate the data into a science community data format standard and store the data in professional archives. Progress is being made in translating Radio Jove data to the Common Data Format (CDF) and also in generating new observations in that format as well. Metadata describing the Radio Jove data would follow the Space Physics Archive Search and Extract (SPASE) standard. The proposed archive to be used for long term preservation would be the Planetary Data System (PDS). Data sharing would be achieved through the PDS and the Paris Astronomical Data Centre (PADC) and the Virtual Wave Observatory (VWO

  18. Extended radio sources in the cluster environment

    International Nuclear Information System (INIS)

    Burns, J.O. Jr.

    1979-01-01

    Extended radio galaxies that lie in rich and poor clusters were studied. A sample of 3CR and 4C radio sources that spatially coincide with poor Zwicky clusters of galaxies was observed to obtain accurate positions and flux densities. Then interferometer observations at a resolution of approx. = 10 arcsec were performed on the sample. The resulting maps were used to determine the nature of the extended source structure, to make secure optical identifications, and to eliminate possible background sources. The results suggest that the environments around both classical double and head-tail radio sources are similar in rich and poor clusters. The majority of the poor cluster sources exhibit some signs of morphological distortion (i.e., head-tails) indicative of dynamic interaction with a relatively dense intracluster medium. A large fraction (60 to 100%) of all radio sources appear to be members of clusters of galaxies if one includes both poor and rich cluster sources. Detailed total intensity and polarization observations for a more restricted sample of two classical double sources and nine head-tail galaxies were also performed. The purpose was to examine the spatial distributions of spectral index and polarization. Thin streams of radio emission appear to connect the nuclear radio-point components to the more extended structures in the head-tail galaxies. It is suggested that a non-relativistic plasma beam can explain both the appearance of the thin streams and larger-scale structure as well as the energy needed to generate the observed radio emission. The rich and poor radio cluster samples are combined to investigate the relationship between source morphology and the scale sizes of clustering. There is some indication that a large fraction of radio sources, including those in these samples, are in superclusters of galaxies

  19. [Ambroise Paré, his death and his historians].

    Science.gov (United States)

    Dumaître, P

    2001-01-01

    Ambroise Paré died December the 20th., 1590. What happened after his death and what are we knowing about his life? Never forgotten, though a lack of care, we were waiting till the XIXth. century to get recollection upon a subject sustained only by accounts of his travels. After Percy, a surgeon who tried to write Paré's biography through the "Biographie universelle ancienne et moderne, de Michaud (1822)" and some second rank authors, Malgaigne is the first who inside a printing of the "Oeuvres complétes de Paré (1840-41)" has a fine look upon the question, though his work is incomplete and allows many mistakes. Doctors Chéreau and Jal, an historian, analysing civil status records, gave new information enlarged by doctors Le Paulmier, Turner and the U.S. native Janet Doe.

  20. Keratometric alterations following the 25-gauge transconjunctival sutureless pars plana vitrectomy versus the conventional pars plana vitrectomy.

    Science.gov (United States)

    Citirik, Mehmet; Batman, Cosar; Bicer, Tolga; Zilelioglu, Orhan

    2009-09-01

    To assess the alterations in keratometric astigmatism following the 25-gauge transconjunctival sutureless pars plana vitrectomy versus the conventional pars plana vitrectomy. Sixteen consecutive patients were enrolled into the study. Conventional vitrectomy was applied to eight of the cases and 25-gauge transconjunctival sutureless vitrectomy was performed in eight patients. Keratometry was performed before and after the surgery. In the 25-gauge transconjunctival sutureless pars plana vitrectomy group, statistically significant changes were not observed in the corneal curvature in any post-operative follow-up measurement (p > 0.05); whereas in the conventional pars plana vitrectomy group, statistically significant changes were observed in the first postoperative day (p = 0.01) and first postoperative month (p = 0.03). We noted that these changes returned to baseline in three months (p = 0.26). Both 25-gauge transconjunctival sutureless and conventional pars plana vitrectomy are effective surgical modalities for selected diseases of the posterior segment. Surgical procedures are critical for the visual rehabilitation of the patients. The post-operative corneal astigmatism of the vitrectomised eyes can be accurately determined at least two months post-operatively.

  1. Mobile radio channel as a complex medium

    DEFF Research Database (Denmark)

    Matic, Dusan; Prasad, Ramjee; Kalluri, Dikshitulu K.

    2001-01-01

    physical phenomena, their implications on the transmitted signal, and how the radio channels are modelled. Special attention is given to the small-scale effects, such as multipath, and Rayleigh and Rice distributions of received signal, as these dominate in the case of indoor communication systems.......Optical fibres have almost unlimited capacity, but can not the address the users desire for mobility and ubiquitous access. The synergy of these two worlds can be seen in the direction of the Radio-over-Fibre. This paper presents to the reader an introduction for the mobile radio channel - basic...

  2. Particle reacceleration and apparent radio source structure

    International Nuclear Information System (INIS)

    Eilek, J.A.

    1982-01-01

    The radio galaxy model which uses magnetohydrodynamic turbulence generated by surface instabilities to reaccelerate the radiating electrons has striking consequences for apparent source structure. Strong wave damping in the plasma results in a narrow turbulent edge. Particles accelerated in this edge must diffuse across field lines into the radio source; this predicts strong limb brightening in some cases. The structure of this edge and diffusion into the source are described. The relevance of this model to jets, radio tails, and standard double sources is discussed

  3. New radio observations of NGC1275

    International Nuclear Information System (INIS)

    Pedlar, A.; Perley, R.; Crane, P.; Harrison, B.; Davies, R.D.

    1986-01-01

    VLA maps are presented for NGC1275 at 20 cm, with resolutions ranging from 1 to 40 arcsec. Over the central 30 arcsec there is evidence for collimated ejection at position angle -160 deg. Outside this region the radio structure bends rapidly by approximately 90 deg before merging into the 10-arcmin radio halo. It is suggested that models of pressure-driven accretion flows should take into account the presence of the relativistic gas which is responsible for the radio halo. 14 references

  4. Blazars with arcminute-scale radio halos

    International Nuclear Information System (INIS)

    Ulvestad, J.S.; Antonucci, R.R.J.; Space Telescope Science Institute, Baltimore, MD)

    1986-01-01

    About 10-arcsec resolution 20-cm wavelength maps are presented for three nearby BL Lac objects: Mkn 180, whose halo has a linear size of 85 kpc, 2155-304, with a halo about 375 kpc across, and 1727 + 502, whose one-sided diffuse emission extends to a distance of about 145 kpc from its radio core. Little evidence is found for strong radio variability in the cores of the three blazars; these and other results obtained are consistent with the assertion that the three objects should be classified as normal low luminosity double radio galaxies with optically dull nuclei, if seen from other directions. 20 references

  5. Cognitive Radio MAC Protocol for WLAN

    DEFF Research Database (Denmark)

    Zhang, Qi; Fitzek, Frank H.P.; Iversen, Villy Bæk

    2008-01-01

    hole; moreover, it designs dual inband sensing scheme to detect primary user appearance. Additionally, C-CSMA/CA has the advantage to effectively solve the cognitive radio self-coexistence issues in the overlapping CR BSSs scenario. It also realizes station-based dynamic resource selection......To solve the performance degradation issue in current WLAN caused by the crowded unlicensed spectrum, we propose a cognitive radio (CR) media access protocol, C-CSMA/CA. The basic idea is that with cognitive radio techniques the WLAN devices can not only access the legacy WLAN unlicensed spectrum...

  6. Radio Imaging of Envelopes of Evolved Stars

    Science.gov (United States)

    Cotton, Bill

    2018-04-01

    This talk will cover imaging of stellar envelopes using radio VLBI techniques; special attention will be paid to the technical differences between radio and optical/IR interferomery. Radio heterodyne receivers allow a straightforward way to derive spectral cubes and full polarization observations. Milliarcsecond resolution of very bright, i.e. non thermal, emission of molecular masers in the envelopes of evolved stars can be achieved using VLBI techniques with baselines of thousands of km. Emission from SiO, H2O and OH masers are commonly seen at increasing distance from the photosphere. The very narrow maser lines allow accurate measurements of the velocity field within the emitting region.

  7. New radio meteor detecting and logging software

    Science.gov (United States)

    Kaufmann, Wolfgang

    2017-08-01

    A new piece of software ``Meteor Logger'' for the radio observation of meteors is described. It analyses an incoming audio stream in the frequency domain to detect a radio meteor signal on the basis of its signature, instead of applying an amplitude threshold. For that reason the distribution of the three frequencies with the highest spectral power are considered over the time (3f method). An auto notch algorithm is developed to prevent the radio meteor signal detection from being jammed by a present interference line. The results of an exemplary logging session are discussed.

  8. Radio continuum, far infrared and star formation

    International Nuclear Information System (INIS)

    Wielebinski, R.; Wunderlich, E.; Klein, U.; Hummel, E.

    1987-01-01

    A very tight correlation was found between the radio emission and the far infrared emission from galaxies. This has been found for various samples of galaxies and is explained in terms of recent star formation. The tight correlation would imply that the total radio emission is a good tracer of star formation. The correlation between the radio power at 5 GHz and the far infrared luminosity is shown. The galaxies are of various morphological types and were selected from the various IRAS circulars, hence the sample is an infrared selected sample. The far infrared luminosities were corrected for the dust temperature. This is significant because it decreases the dispersion in the correlation

  9. Diagnosis of Intracranial Lesions by Gamma-Encephalography using Human Serum Albumin Labelled with Iodine-131; Diagnostic des lesions intracraniennes par la gamma-encephalographie a l'aide de la serumalbumine humaine marquee a l'iode 131; Diagnoz vnutricherepnykh povrezhdenij putem gamma-ehntsefalografii pri pomoshchi mechenoj iodom-131 albuminovoj syvorotki cheloveka; Diagnostico de las lesiones intracraneanas por gammaencefalografia mediante sero- albumina humana marcada con yodo-131

    Energy Technology Data Exchange (ETDEWEB)

    Planiol, Therese [Institut National d' Hygiene, Paris (France)

    1959-07-01

    Six hundred patients were examined by means of serum albumin labelled with iodine-131. Radioactivity was read twice with an scintillation counter in contact with the skull, two hours and twenty-four hours after the radioactive injection. Of 175 intracranial tumours, 150 were accompanied by a focus of persistent gamma hyperactivity. Of those not detected by the examination, half were tumours of the hemispheres and half of the posterior fossa and pineal body. Abscesses, haematomata and cirsoid aneurisms were detected. In one-third of the cases acute cerebro-vascular lesions produced abnormal readings, half of which had the peculiar appearance pathognomonic of softening (or thrombosis); the others resembled tumour graphs, the only difference being that the abnormal readings associated with acute vascular lesions disappeared in a few weeks. Two-thirds of these acute lesions were associated with a negative gamma-encephalogram. Arterial aneurisms, non-tumourous epileptogenic foci, and various purely neurological conditions gave normal results in 96 per cent of cases. Brain investigation by radioalbumin can provide valuable information not only on the presence and exact location of a neurosurgical injury but also on its nature. In particular, it seems very likely to detect a meningioma, glioblastoma or metastatic growth. These properties, together with information on positive diagnosis and location, make it a specially useful neurodiagnostic method. Gamma-encephalography also seems likely to be one of the most reliable ways of detecting relapses and of following-up the effects of medical treatment or radiotherapy. (author) [French] 600 malades ont ete examines a l'aide de la serumalbumine marquee a l'iode 131, les mesures de radioactivite etant faites par un compteur a scintillations place au contact du crane, en deux seances, deux heures et vingt-quatre heures apres l'injection radioactive. Sur 175 tumeurs intracraniennes, 150 se sont accompagnees d'un foyer d

  10. Cyclanthaceae no estado do Pará, Brasil Cyclanthaceae in Pará State, Brazil

    Directory of Open Access Journals (Sweden)

    Eduardo da Silva Leal

    2012-12-01

    Full Text Available Cyclanthaceae apresenta distribuição exclusiva na região neotropical sendo bem diversificada nas terras baixas das florestas pluviais tropicais, ocorrendo do sul do México até a Mata Atlântica do sul do Brasil. Consistem de ervas terrestres, epífitas, hemiepífitas ou lianas. O tratamento taxonômico de Cyclanthaceae no Pará foi baseado em coleções de herbário, trabalhos de campo e consulta a bibliografia referente à família. Foram registradas 11 espécies: Asplundia altiscandens E.S. Leal, A. fanshawei (Maguire Harling, A. glandulosa (Gleason Harling, A. heteranthera Harling, A. latifrons (Drude Harling, A. schizotepala Harling, A. xiphophylla Harling, Cyclanthus bipartitus Poit. ex A. Rich., Evodianthus funifer (Poit. Lindm., Ludovia lancifolia Brongn. e Thoracocarpus bissectus (Vell. Harling. São apresentadas chave de identificação, descrições e ilustrações das espécies, além de comentários sobre distribuição geográfica, hábitat e período de floração e frutificação.Cyclanthaceae is a family with a distribution exclusively in the Neotropics and is well diversified in lowland rainforests, occurring from southern Mexico to the Atlantic Forest of southern Brazil. The family consists of terrestrial herbs, epiphytes, hemiepiphytes and lianas. This taxonomic treatment of the Cyclanthaceae from the state of Pará was based on herbarium specimens, fieldwork, and the literature. Eleven species were recorded: Asplundia altiscandens E.S. Leal, A. fanshawei (Maguire Harling, A. glandulosa (Gleason Harling, A. heteranthera Harling, A. latifrons (Drude Harling, A. schizotepala Harling, A. xiphophylla Harling, Cyclanthus bipartitus Poit. ex A. Rich., Evodianthus funifer (Poit. Lindm., Ludovia lancifolia Brongn. and Thoracocarpus bissectus (Vell. Harling. An identification key, descriptions and illustrations of species are presented. Additional information on the geographic distribution, habitat, and flowering and

  11. Canning by the diffusion caused by a heated die; Gainage par diffusion par filiere chauffante

    Energy Technology Data Exchange (ETDEWEB)

    Gauthron, M [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In this process, the uranium fuel is clad with a zirconium can by passing the element through a die. The operation takes place at a temperature varying between 500 and 1000 deg. C. The heating is obtained by passing low voltage electric current through the can. This process differs from the co-extrusion process in that the uranium is not deformed. The uranium is therefore machined to the final dimensions before canning, it can also be hollow. Two types of processes can be adopted for the extrusion: a) Process in which the binding of the can to the uranium is obtained without diffusion (here the can is at high temperature - subsequently cooled - and the uranium is at a low temperature); b) Process in which uranium-zirconium diffusion is initiated. No matter which process is adopted the element is subsequently heat treated in an over at 800 deg. C in order to obtain the final diffusion. The quality of this diffusion is dependent on the initial state of the surfaces and on the degree of vacuum maintained during the operation. (author) [French] Dans ce procede, la gaine zirconium est plaquee sur le combustible uranium par passage dans une filiere. L'operation a lieu a chaud, a une temperature variant entre 500 et 1000 deg. C. Le chauffage est assure par passage d'un courant basse tension dans la gaine. A la difference du procede de cofilage, l'uranium ne subit pas de deformation durant l'operation. Il est donc prealablement usine aux cotes definitives et peut etre creux. Deux processus sont possibles pendant le passage dans la filiere: a) Obtention d'un frettage de la gaine sur l'uranium sans diffusion (avec une gaine a haute temperature et un tube d'uranium a basse temperature, eventuellement refroidi); b) Obtention d'un commencement de diffusion uranium-zirconium. Quelque soit le processus adopte, la cartouche est ensuite traitee dans un four a 800 deg. C pour obtenir la diffusion definitive. La qualite de celle-ci depend essentiellement des etats de surface initiaux

  12. La projection par plasma : une revue

    Science.gov (United States)

    Fauchais, P.; Grimaud, A.; Vardelle, A.; Vardelle, M.

    are presented in the fields of aeronautics and mechanics. La qualité d'un dépôt projete par plasma dépend de nombreux paramètres que l'on commence à mieux appréhender du fait des progrès de la modélisation et de la métrologie tant des écoulements plasmas que des transferts plasma-particules ou que des conditions d'écrasement et de refroidissement des particules lors de leur impact sur le substrat ou les couches déjà déposées. Les techniques de mesure utilisdes et leurs limitations sont d'abord rappelées tant pour les jets de plasma que pour les particules en vol et l'importance des différents phénomènes intervenant dans les transferts plasma-particules est soulignée : gradients de température et de concentration d'espèces chimiques très élevés autour des particules, effets de propagation de la chaleur, notamment pour les particules céramiques, effet d'évaporation, effet de raréfaction sensible dès la pression atmosphérique. Les problèmes de distribution de taille et de vitesse d'injection des particules sont également abordés car ils conditionnent les distributions de trajectoires et donc le traitement des particules dans le jet de plasma. La génération du plasma montre d'une part 1'influence considérable de l'injection du gaz, de sa nature, du dessin de la chambre d'arc et de la tuyère ainsi que du pompage de l'air ambiant sur la longueur des jets de plasma d'arc et d'autre part les problèmes d'injection pour éviter le couplage avec la décharge dans les jets de plasmas R.E Tout ceci est illustré avec des exemples de dépôt d'alumine, de zircone, de cermet carbure et de nickel. L'écrasement des particules est ensuite abordé avec les problèmes de réactions chimiques, de trempe ultra-rapide et donc de structure cristalline des dépôts, d'adhdsion mais aussi de containtes résiduelles et de leur contrôle via les gradients de température dans les dépôts pendant le tir. Enfin quelques applications actuelles sont pr

  13. NAC/NINE Program Building Radio Jove's and Brining Radio Astronomy to the Community

    Science.gov (United States)

    Ramona Gallego, Angelina; Paul Gueye, Al Amin Kabir,

    2018-01-01

    During the course of the 8-week program, (NINE, National and International Non-Traditional Exchange Program), the summer was spent in Socorro, New Mexico, working on building a Radio Jove, and making observations with the Radio Jove as well as working on learning project management practices in order to take the CAPM PMI Exam. The NINE built the Radio Jove’s at the same time and in doing so learned to replicate it to teach it to others. The final portion of the program that was worked on was to create a NINE hub and do outreach with the community teaching them about radio astronomy and teaching students how to build their own Radio Jove’s and make observations. An important aspect of the summer program was to bring back the knowledge received about radio astronomy and teach it to high school students with the help of the institution each NINE participants came from.

  14. Radio-chromatographic determination of plasmatic adenosine deaminase (A.D.); Determination radiochromatographique de l'adenosine deaminase (A.D.)

    Energy Technology Data Exchange (ETDEWEB)

    Chivot, J J; Depernet, D; Caen, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    We were able, by using a radio-chromatographic method, to measure an adenosine deaminase activity in normal human heparinized platelet-poor plasma, which can degrade 0.016 {mu}M adenosine. This activity suppressed by heating 56 C for 30 minutes is inhibited by high concentrations of urea and is proportional to the amount of plasma, source of enzyme, in the systems. (authors) [French] Nous avons pu, en utilisant une methode radiochromatographique, mesurer une activite adenosine deaminasique dans le plasma humain pauvre en plaquettes heparine qui peut degrader 0,016 {mu}M d'adenosine. Cette activite qui est supprimee par chauffage a 56 degres pendant 30 minutes, est reduite par conservation a -20 C pendant une semaine, est inhibee par d'importantes concentrations d'uree et ne l'est pas, ni par le dipyridamol, ni par le pHMB. Cette activite est proportionnelle a la quantite de plasma, source d'enzyme, mise dans les differents systemes reactifs. (auteur)

  15. Aliphatic Nucleophilic Radio-fluorination

    International Nuclear Information System (INIS)

    Roeda, D.; Dolle, F.

    2010-01-01

    In this review we are looking at some aspects of nucleophilic aliphatic radio-fluorination, notably the labelled fluoride source, design aspects, the leaving group and the solvent. It should be clear that there is more to this branch of radiolabelling than one would suspect from the frequently used standard tosylate replacement with kryptofix/[ 18 F]fluoride in acetonitrile or DMSO. Competitive elimination can be a serious problem that can affect both yield and purification. De-protection of sensitive groups after radiolabelling and its possible side reactions can complicate purification. The right choice of leaving group and protecting groups may be crucial. Newer developments such as the use of tertiary alcohols or ionic liquids as solvents, long-chain poly-fluorinated sulphonate leaving groups facilitating fluorous solid phase extraction, or immobilisation of the precursor on a solid phase support may help to solve these problems, for example the longstanding problems with [ 18 F]FLT, whereas older concepts such as certain cyclic reactive entities for ring opening or even an abandoned reagent as [ 18 F]DAST should not be forgotten. (authors)

  16. Nganyi Community Resource Centre: Community radio station ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-05-04

    May 4, 2016 ... To mark World Meteorological Day on March 23, 2015, the Kenya Meteorological Services (KMS) launched a resource centre and radio station in western Kenya to disseminate weather and climate information.

  17. Mean field games for cognitive radio networks

    KAUST Repository

    Tembine, Hamidou; Tempone, Raul; Vilanova, Pedro

    2012-01-01

    In this paper we study mobility effect and power saving in cognitive radio networks using mean field games. We consider two types of users: primary and secondary users. When active, each secondary transmitter-receiver uses carrier sensing

  18. Fabrication of superconducting niobium radio frequency structures

    International Nuclear Information System (INIS)

    Kirchgessner, J.; Amato, J.; Brawley, J.

    1983-01-01

    During the last several years a variety of superconducting radio frequency structures have been designed, fabricated and tested. The diverse structures and fabrication techniques are described. This paper is a description of the authors' experiences in this field

  19. Solar energetic particles and radio burst emission

    Directory of Open Access Journals (Sweden)

    Miteva Rositsa

    2017-01-01

    Full Text Available We present a statistical study on the observed solar radio burst emission associated with the origin of in situ detected solar energetic particles. Several proton event catalogs in the period 1996–2016 are used. At the time of appearance of the particle origin (flare and coronal mass ejection we identified radio burst signatures of types II, III and IV by inspecting dynamic radio spectral plots. The information from observatory reports is also accounted for during the analysis. The occurrence of solar radio burst signatures is evaluated within selected wavelength ranges during the solar cycle 23 and the ongoing 24. Finally, we present the burst occurrence trends with respect to the intensity of the proton events and the location of their solar origin.

  20. Ionosphere and its Influence on Radio Communications

    Indian Academy of Sciences (India)

    Italian radio pioneer G Marconi succeeded in transmitting. 'wireless' signals over a distance of about 2000 miles across the. Atlantic Ocean. Physicists had .... indirectly, to the ionizing power of the solar radiation. As this radiation penetrates the ...

  1. Rural Radio in Bolivia: A Case Study.

    Science.gov (United States)

    Gwyn, Robert J.

    1983-01-01

    Examines the programing and audiences of two small rural commercial radio stations in the Jordan and Punata provinces. Shows how these stations have interacted with the local culture and how they offer significant potential for development. (PD)

  2. Radio transmission system for industrial area

    International Nuclear Information System (INIS)

    Iliescu, M.; Culcer, M.; Curuia, M.; Anghel, N.M.; Stefanescu, I.

    2003-01-01

    The paper deals with a data transmission system operating in a large, noisy industrial area. The radio transmission system permits data and commands communication between the local units of collecting data and a central monitoring and/or command station ( dispatch). The communication support are radio waves in the range 450 MHz. The transducers are of transmitter type, with 4-20 mA output signal, providing information about environmental and/or work parameters. Data are primarily acquisitioned in a data logger with microcontroller, then transmitted via a FSK radio modem and a radio station to the dispatch. Data logger can also be connected in a network. The dispatch personal computer receives and processes data and transmits commands. The system functioning is supervised by a communication software in MCS - 51 assembler and an application software in Visual C ++ . (author)

  3. Information Management: Military Affiliate Radio System (MARS)

    National Research Council Canada - National Science Library

    1986-01-01

    .... It describes a program sponsored by the Department of Defense and supported by the Department of the Army in which military installations, military units, clubs, and volunteer licensed amateur radio...

  4. Software Defined Multiband EVA Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this research is to propose a reliable, lightweight, programmable, multi-band, multi-mode, miniaturized frequency-agile EVA software defined radio...

  5. Reconfigurable, Cognitive Software Defined Radio, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — IAI is actively developing Software Defined Radio platforms that can adaptively switch between different modes of operation by modifying both transmit waveforms and...

  6. Software Defined Multiband EVA Radio, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of Phase 2 is to build a reliable, lightweight, programmable, multi-mode, miniaturized EVA Software Defined Radio (SDR) that supports data telemetry,...

  7. Distortion mitigation in cognitive radio receivers

    NARCIS (Netherlands)

    Mahrof, D.H.

    2015-01-01

    The exponential increase of wireless communication increasingly leads to spectrum congestion. Attempts are being made to increase RF spectrum utilization efficiency by introducing Cognitive Radio (CR) concept. A CR tries to intelligently solve the congestion problem via Dynamic Spectrum Access

  8. mathematical models for estimating radio channels utilization

    African Journals Online (AJOL)

    2017-08-08

    Aug 8, 2017 ... Mathematical models for radio channels utilization assessment by real-time flows transfer in ... data transmission networks application having dynamic topology ..... Journal of Applied Mathematics and Statistics, 56(2): 85–90.

  9. Hybrid cognitive engine for radio systems adaptation

    KAUST Repository

    Alqerm, Ismail; Shihada, Basem

    2017-01-01

    of our hybrid engine is validated using software defined radios implementation and simulation in multi-carrier environment. The system throughput, signal to noise and interference ratio, and packet error rate are obtained and compared with other schemes

  10. Reconfigurable, Cognitive Software Defined Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Automation Inc, (IAI) is currently developing a software defined radio (SDR) platform that can adaptively switch between different modes of operation for...

  11. 49 CFR 220.23 - Publication of radio information.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Publication of radio information. 220.23 Section... § 220.23 Publication of radio information. Each railroad shall designate where radio base stations are.... The publication shall indicate the periods during which base and wayside radio stations are...

  12. Community Radio in Political Theory and Development Practice

    African Journals Online (AJOL)

    zeleza

    These structural and conceptual elements provide community radio the ... characteristic problems of development projects based on its theoretical and structural .... and to fix basic radio equipment is a standard practice of community radio stations. ... community radio stations and participatory media organizations, but also ...

  13. 47 CFR 2.107 - Radio astronomy station notification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy stations...

  14. Survival and reproduction of radio-marked adult spotted owls.

    Science.gov (United States)

    C.C. Foster; E.D. Forsman; E.C. Meslow; G.S. Miller; J.A. Reid; F.F. Wagner; A.B. Carey; J.B. Lint

    1992-01-01

    We compared survival, reproduction, and body mass of radio-marked and non radio-marked spotted owls (Strix occidentalis) to determine if backpack radios influenced reproduction or survival. In most study areas and years, there were no differences (P > 0.05) in survival of males and females or in survival of radio-marked versus banded owls. There...

  15. Communicating Science for Impact: Radio for Reaching Farmers ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Radio to share results The project will translate research results into simple radio campaign messages targeting small-scale farmers. Researchers will test ... The project will assess the effect of radio campaigns in influencing adoption decisions among listeners. Farm Radio ... Agent(e) responsable du CRDI. crmadm CRM ...

  16. 47 CFR 20.9 - Commercial mobile radio service.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Commercial mobile radio service. 20.9 Section... COMMERCIAL MOBILE RADIO SERVICES § 20.9 Commercial mobile radio service. (a) The following mobile services shall be treated as common carriage services and regulated as commercial mobile radio services...

  17. Sending the right message : forty years of BBC Radio News

    NARCIS (Netherlands)

    Luscombe-Serlie, J.C.

    2012-01-01

    Radio is, compared to television and newspapers, an under-researched area in media studies. This research has looked at BBC Radio News in the period 1966-2008; it is a case study into the views of 43 (former) writers of the BBC Radio Newsroom and BBC Radio One. Interviews were conducted with

  18. Paradigms of modern radio-biology

    International Nuclear Information System (INIS)

    Grodzins'kij, D.M.

    2005-01-01

    The basic paradigms of modern radio-biology are considered as models of pictures of essence of radio-biology problems and methods of their decision. It is marked on absolute heuristics of these ascending conceptual assertions and their assistance to subsequent development of experimental science. That has the concrete display in the decision of actual tasks of protection of people from action of ionizing radiation

  19. First Colombian Solar Radio Interferometer: current stage

    Science.gov (United States)

    Guevara Gómez, J. C.; Martínez Oliveros, J. C.; Calvo-Mozo, B.

    2017-10-01

    Solar radio astronomy is a fast developing research field in Colombia. Here, we present the scientific goals, specifications and current state of the First Colombian Solar Radio Interferometer consisting of two log-periodic antennas covering a frequency bandwidth op to 800 MHz. We describe the importance and benefits of its development to the radioastronomy in Latin America and its impact on the scientific community and general public.

  20. Designing for cooperation at a Radio Station

    DEFF Research Database (Denmark)

    Kensing, F.; Simonsen, Jesper; Bødker, Keld

    1997-01-01

    We address computer support for work and its coordination in one of the radio channels of the Danish Broadcasting Corporation. Based upon ethnographically inspired analysis and participatory design techniques, we propose design solutions now implemented or under implementation. We focus on cooper......We address computer support for work and its coordination in one of the radio channels of the Danish Broadcasting Corporation. Based upon ethnographically inspired analysis and participatory design techniques, we propose design solutions now implemented or under implementation. We focus...

  1. Big Data Challenges for Large Radio Arrays

    Science.gov (United States)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  2. Mengusung Masyarakat Madani Melalui Radio Komunitas

    Directory of Open Access Journals (Sweden)

    Dede Lilis Chaerowati

    2013-12-01

    Full Text Available This article is about the phenomenon of community radio in Pantura Area, West Java. Radio communities maganed by, for and about the community are rapidly developing among the farmers and fishermen, including in Pantura Area, West Java. The focus of the study is the formation of civil society by standing firmly on communicative actions of Jürgen Habermas. By using qualitative method with case study design, a finding would be produced that community radios implement participatory paradigm and manage community cohesion. We will discuss in details on: (1 initiators of the establishment of community radio, (2 forms of community participation, (3 the financing source of community radio, and (4 the construction of civil society through community radio. This article also covers about how the people see the world of life, that there is social transformation through emancipatordialogs, which then produce community’s selfconsciousness  as individuals and community members in demanding a domination-free communication process. This reality creates the origination of civil society.

  3. Radio-flaring Ultracool Dwarf Population Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Route, Matthew, E-mail: mroute@purdue.edu [Department of Astronomy and Astrophysics, the Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2017-08-10

    Over a dozen ultracool dwarfs (UCDs), low-mass objects of spectral types ≥M7, are known to be sources of radio flares. These typically several-minutes-long radio bursts can be up to 100% circularly polarized and have high brightness temperatures, consistent with coherent emission via the electron cyclotron maser operating in approximately kilogauss magnetic fields. Recently, the statistical properties of the bulk physical parameters that describe these UCDs have become described adequately enough to permit synthesis of the population of radio-flaring objects. For the first time, I construct a Monte Carlo simulator to model the population of these radio-flaring UCDs. This simulator is powered by Intel Secure Key (ISK), a new processor technology that uses a local entropy source to improve random number generation that has heretofore been used to improve cryptography. The results from this simulator indicate that only ∼5% of radio-flaring UCDs within the local interstellar neighborhood (<25 pc away) have been discovered. I discuss a number of scenarios that may explain this radio-flaring fraction and suggest that the observed behavior is likely a result of several factors. The performance of ISK as compared to other pseudorandom number generators is also evaluated, and its potential utility for other astrophysical codes is briefly described.

  4. Radio Source Morphology: 'nature or nuture'?

    Science.gov (United States)

    Banfield, Julie; Emonts, Bjorn; O'Sullivan, Shane

    2012-10-01

    Radio sources, emanating from supermassive black-holes in the centres of active galaxies, display a large variety of morphological properties. It is a long-standing debate to what extent the differences between various types of radio sources are due to intrinsic properties of the central engine (`nature') or due to the properties of the interstellar medium that surrounds the central engine and host galaxy (`nurture'). Settling this `nature vs. nurture' debate for nearby radio galaxies, which can be studied in great detail, is vital for understanding the properties and evolution of radio galaxies throughout the Universe. We propose to observe the radio galaxy NGC 612 where previous observations have detected the presence of a large-scale HI bridge between the host galaxy and a nearby galaxy NGC 619. We request a total of 13 hrs in the 750m array-configuration to determine whether or not the 100 kpc-scale radio source morphology is directly related to the intergalactic distribution of neutral hydrogen gas.

  5. Radio-quiet Gamma-ray Pulsars

    Directory of Open Access Journals (Sweden)

    Lupin Chun-Che Lin

    2016-09-01

    Full Text Available A radio-quiet γ-ray pulsar is a neutron star that has significant γ-ray pulsation but without observed radio emission or only limited emission detected by high sensitivity radio surveys. The launch of the Fermi spacecraft in 2008 opened a new epoch to study the population of these pulsars. In the 2nd Fermi Large Area Telescope catalog of γ-ray pulsars, there are 35 (30 % of the 117 pulsars in the catalog known samples classified as radio-quiet γ-ray pulsars with radio flux density (S1400 of less than 30 μJy. Accompanying the observations obtained in various wavelengths, astronomers not only have the opportunity to study the emitting nature of radio-quiet γ-ray pulsars but also have proposed different models to explain their radiation mechanism. This article will review the history of the discovery, the emission properties, and the previous efforts to study pulsars in this population. Some particular cases known as Geminga-like pulsars (e.g., PSR J0633+1746, PSR J0007+7303, PSR J2021+4026, and so on are also to specified discuss their common and specific features.

  6. Parasitisme de Dacryodes edulis par le genre Tapinanthus ...

    African Journals Online (AJOL)

    SARAH

    31 août 2013 ... Parasitisme de Dacryodes edulis par le genre. Tapinanthus (Loranthaceae) et répartition de la myrmécofaune associée à Logbessou Plateau. (Douala, Cameroun). Massako F1*, Tchatat M2, Mony R3, Ladoh Yemeda CF1, Dibong SD1,4,5. 1Laboratoire de Biologie et Physiologie des Organismes ...

  7. Parasitisme des champs semenciers de cacaoyers par les ...

    African Journals Online (AJOL)

    SARAH

    30 janv. 2015 ... J. Appl. Biosci. Parasitisme des champs semenciers de cacaoyers par les loranthaceae dans la localité de Nkoemvone (sud Cameroun). 7795 to the various clones, Phragmanthera capitata was the most abundant Loranthaceae; the level of parasitism of cacao trees is more important at the cacao trees of ...

  8. Den eneste ene - hvordan etniske minoritetsunge i Danmark danner par

    DEFF Research Database (Denmark)

    Singla, Rashmi

    Rapporten handler om etniske unges måde at danne par på. Rapporten er baseret på en større empirisk undersøgelse gennemført af forfatteren i 2003 og er desuden inspireret af forfatterens egen ph.d.-afhandling: "Ungdom, etnicitet og psychosocial intervention" (2000, Københavns Universitet). Rappor...

  9. Indications and visual outcome of first hundred pars plana ...

    African Journals Online (AJOL)

    Objective: To review the indications and visual outcome of the first one hundred pars plana vitrectomies performed at the newly established surgical retina unit of Makkah Specialist Eye Hospital, Kano, Kano State, Nigeria. Materials and Methods: Aretrospective chart review was performed. Data recorded from the patient ...

  10. Epuration des effluents industriels par électroflottation Belkacem ...

    African Journals Online (AJOL)

    étudié la séparation de quelques métaux lourds tels que le fer, le nickel, ... the separation of some heavy metals such as iron, nickel, copper, zinc, lead and ... généralement basées sur l'adsorption (par ... Différents essais de concentration en.

  11. Predicting spectral and PAR light attenuation in Greenlandic coastal waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Markager, Stiig; Stedmon, Colin

    (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  12. Priapisme induit par la chlorpromazine: A propos de deux cas

    Directory of Open Access Journals (Sweden)

    I. Marrag

    2016-06-01

    Le priapisme veineux est une urgence urologique. Il constitue un des effets secondaires des neuroleptiques parmi les quels la chlorpromazine. Cet effet iatrogène, qui est rare mais grave, doit être connu par les cliniciens afin d’être mieux prévenu pour éviter les séquelles érectiles.

  13. La lecture de Merleau-Ponty par Renaud Barbaras

    Czech Academy of Sciences Publication Activity Database

    Pechar, Jiří

    2015-01-01

    Roč. 11, č. 2 (2015), s. 1-6 ISSN 1336-6556 Institutional support: RVO:67985955 Keywords : Merleau-Ponty * Husserl * phenomenology * linguistics of Ferdinand de Saussure Subject RIV: AA - Philosophy ; Religion http://www.ostium.sk/sk/la-lecture-de-merleau-ponty-par-renaud-barbaras/

  14. Par Pond vegetation status summer 1995 - July survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-07-01

    A survey of the emergent shoreline aquatic plant, communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet (61 meters) above mean sea level, and continued with this July survey. Aquatic plant communities, similar to the pre-drawdown Par Pond communities, are becoming reestablished. Beds of maidencane (Panicum hemitomon), lotus (Nelumbo lutea), water lily (Nymphaea odorata), and watershield (Brasenia schreberi) are now extensive and well established. In addition, within isolated coves, extensive beds of water lilies and spike-rush (Eleocharis sp.) are common. Cattail occurrence has increased since refill, but large beds common to Par Pond prior to the drawdown have not formed. Invasion of willow (Salix sp.) and red maple (Acer rubrum) occurred along the lake shoreline during drawdown. The red maples along the present shoreline are beginning to show evidence of stress and mortality from flooding over the past four months. Some of the willows appear to be stressed as well. The loblolly pines (Pinus taeda), which were flooded in all but the shallow shoreline areas, are now dead. Future surveys are planned for the growing seasons of 1995, 1996, and 1997, along with the evaluation of satellite data for mapping the areal extent of the macrophyte beds of Par Pond

  15. fortification des farines tropicales par l'introduction de proteines ...

    African Journals Online (AJOL)

    2Université d'Abomey Calavy, Faculté des Sciences et Techniques, Bénin ... valeur recommandée par le Codex Alimentarius pour ce type de complément alimentaire destiné aux enfants. ..... neurotransmission, coagulation sanguine et.

  16. Radio peptide imaging and therapy

    International Nuclear Information System (INIS)

    Buscombe, Jonh

    1997-01-01

    Full text. The concept of the magic bullet retains its attraction to us. If only we could take a drug or radioisotope and inject this intravenously and then will attach to the target cancer. This may allow imaging if labelled with a radio pharmaceutical or possibly even effective therapy. Initially work was started using antibodies of mouse origin. These have shown some utility in targeting tumors but there are problems in that these are essentially non-human proteins, often derived from mice. This leads to the formation of antibodies against that antibody so that repeat administrations lead to reduced efficacy and possibly may carry a risk anaphylaxis for the patient. Two different methods have evolved to deal with this situation. Either make antibodies more human or use smaller fragments, so that they are less likely to cause allergic reactions. The second method is to try and use a synthetic peptide. This will contain a series of amino acids which recognize a certain cell receptor. For example the somatostatin analogue Octreotide is an 8 amino acid peptide which has the same biological actions as natural somatostatin but an increased plasma half life. To this is added a linker a good example being DTPA and then radioisotope for example In-111. There we can have the complex In-111-DTPA-Octreotide which can be used to image somatostatin receptors in vivo. The main advantage over antibodies is that the cost production is less and many different variation of peptides for a particular receptor can be manufactured and assessed to find which is the optimal agent tumour imaging at a fraction of the cost of antibody production. There are two main approaches. Firstly to take a natural peptide hormone such as insulin or VIP and label by a simple method such as iodination with I-123. A group in Vienna have done it and shown good uptake of I-123 Insulin in primary hepatomas and of I-123 VIP in pancreatic cancers. Many natural peptide hormones however have a short plasma half

  17. The Determination of Uranium in Urine by Delayed Neutron Counting; Dosage de l'Uranium dans l'Urine par Comptage des Neutrons Differes; Opredelenie soderzhaniya urana v moche putem scheta zapazdyvayushchikh nejtronov; Determinacion del Uranio Contenido en la Orina por Recuento de Neutrones Retardados

    Energy Technology Data Exchange (ETDEWEB)

    Brookes, I. R. [Atomic Weapons Research Establishment, Aldermaston, Berks. (United Kingdom)

    1965-10-15

    polyethylene d'une capacite de 2,85 cl, qui est scelle a chaud. Le flacon contenant l'echantillon est enferme dans un tube et envoye par un systeme pneumatique dans le coeur du reacteur HERALD ou il est irradie par un fieux de neutrons thermiques de 3,94 * 10{sup 12}n/cm{sup 2}s. Apres une irradiation de 1 min, l'echantillon retourne automatiquement au laboratoire ou le flacon contenant l'echantillon est place dans un compteur a neutrons. Ce compteur est mis en marche 25 s apres que l'echantillon a quitte le reacteur et compte l'echantillon pendant 1 min. Les echantillons temoins se composent d'urine provenant de personnes qui ne sont pas professionnellement exposees a l'uranium; l'etalon est une quantite connue de {sup 235}U (sous forme d'uranium naturel). La limite de detection est de 0,020 pCi d'uranium enrichi a 93% ou de 0,026 {mu}g d'uranium naturel (0,007 de la charge corporelle maximale admissible) et de 0,036 {mu}g d'uranium naturel pour 100 ml d'urine. Elle depend du nombre de coups correspondant aux temoins. La composante principale du temoin est la reponse du compteur aux rayons gamma emis par les produits d'activation que l'urine irradiee contient. Il faut 3,5 min environ pour irradier et compter un echantillon et l'on peut, au cours d'une journee de travail, faire evaporer et traiter 50 echantillons pour les mettre en flacons. Pour les analyses d'urine, l'influence de {sup 239}Pu peut etre consideree comme negligeable. (author) [Spanish] Con arreglo al metodo del autor, el uranio-235 se determina por recuento de los neutrones retardados emitidos a raiz de la fision por neutrones termicos del {sup 235}U contenido en la muestra. Los tres grupos de neutrones que se consideran tienen periodos de 55, 72, 22, 72 y 6, 22 s, respectivamente. En un bano Maria se evaporan a sequedad 100 mi de orina. El residuo se pasa con unos 4 a 5 mi de agua a un frasco de polietileno de 1 onza, que se cierra seguidamente por soldadura termica. El frasco con la muestra se coloca en un

  18. Plasma Diagnostics of the Interstellar Medium with Radio Astronomy

    OpenAIRE

    Haverkorn, Marijke; Spangler, Steven R.

    2013-01-01

    We discuss the degree to which radio propagation measurements diagnose conditions in the ionized gas of the interstellar medium (ISM). The "signal generators" of the radio waves of interest are extragalactic radio sources (quasars and radio galaxies), as well as Galactic sources, primarily pulsars. The polarized synchrotron radiation of the Galactic non-thermal radiation also serves to probe the ISM, including space between the emitting regions and the solar system. Radio propagation measurem...

  19. The role of pars flaccida in human middle ear sound transmission.

    Science.gov (United States)

    Aritomo, H; Goode, R L; Gonzalez, J

    1988-04-01

    The role of the pars flaccida in middle ear sound transmission was studied with the use of twelve otoscopically normal, fresh, human temporal bones. Peak-to-peak umbo displacement in response to a constant sound pressure level at the tympanic membrane was measured with a noncontacting video measuring system capable of repeatable measurements down to 0.2 micron. Measurements were made before and after pars flaccida modifications at 18 frequencies between 100 and 4000 Hz. Four pars flaccida modifications were studied: (1) acoustic insulation of the pars flaccida to the ear canal with a silicone rubber baffle, (2) stiffening the pars flaccida with cyanoacrylate cement, (3) decreasing the tension of the pars flaccida with a nonperforating incision, and (4) perforation of the pars flaccida. All of the modifications (except the perforation) had a minimal effect on umbo displacement; this seems to imply that the pars flaccida has a minor acoustic role in human beings.

  20. VLA radio observations of AR Scorpii

    Science.gov (United States)

    Stanway, E. R.; Marsh, T. R.; Chote, P.; Gänsicke, B. T.; Steeghs, D.; Wheatley, P. J.

    2018-03-01

    Aims: AR Scorpii is unique amongst known white dwarf binaries in showing powerful pulsations extending to radio frequencies. Here we aim to investigate the multi-frequency radio emission of AR Sco in detail, in order to constrain its origin and emission mechanisms. Methods: We present interferometric radio frequency imaging of AR Sco at 1.5, 5 and 9 GHz, analysing the total flux and polarization behaviour of this source at high time resolution (10, 3 and 3 s), across a full 3.6 h orbital period in each band. Results: We find strong modulation of the radio flux on the orbital period and the orbital sideband of the white dwarf's spin period (also known as the "beat" period). This indicates that, like the optical flux, the radio flux arises predominantly from on or near the inner surface of the M-dwarf companion star. The beat-phase pulsations of AR Sco decrease in strength with decreasing frequency. They are strongest at 9 GHz and at an orbital phase 0.5. Unlike the optical emission from this source, radio emission from AR Sco shows weak linear polarization but very strong circular polarization, reaching 30% at an orbital phase 0.8. We infer the probable existence of a non-relativistic cyclotron emission component, which dominates at low radio frequencies. Given the required magnetic fields, this also likely arises from on or near the M-dwarf. A table of the flux time series is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A66

  1. Curved Radio Spectra of Weak Cluster Shocks

    Science.gov (United States)

    Kang, Hyesung; Ryu, Dongsu

    2015-08-01

    In order to understand certain observed features of arc-like giant radio relics such as the rareness, uniform surface brightness, and curved integrated spectra, we explore a diffusive shock acceleration (DSA) model for radio relics in which a spherical shock impinges on a magnetized cloud containing fossil relativistic electrons. Toward this end, we perform DSA simulations of spherical shocks with the parameters relevant for the Sausage radio relic in cluster CIZA J2242.8+5301, and calculate the ensuing radio synchrotron emission from re-accelerated electrons. Three types of fossil electron populations are considered: a delta-function like population with the shock injection momentum, a power-law distribution, and a power law with an exponential cutoff. The surface brightness profile of the radio-emitting postshock region and the volume-integrated radio spectrum are calculated and compared with observations. We find that the observed width of the Sausage relic can be explained reasonably well by shocks with speed {u}{{s}}˜ 3× {10}3 {km} {{{s}}}-1 and sonic Mach number {M}{{s}}˜ 3. These shocks produce curved radio spectra that steepen gradually over (0.1-10){ν }{br} with a break frequency {ν }{br}˜ 1 GHz if the duration of electron acceleration is ˜60-80 Myr. However, the abrupt increase in the spectral index above ˜1.5 GHz observed in the Sausage relic seems to indicate that additional physical processes, other than radiative losses, operate for electrons with {γ }{{e}}≳ {10}4.

  2. Perancangan Radio Streaming Edukasi (Studi Kasus Balai Pengembangan Media Radio YOGYAKARTA)

    OpenAIRE

    Nurwulan, Ayu Isni; Paputungan, Irving Vitra

    2009-01-01

    Pendidikan berkualitas sudah sewajarnya bisa dinikmati secara merata oleh semua orang. Mediapembelajaran secara audio yang selama ini disampaikan masih memiliki banyak keterbatasan, terutama padalingkup wilayah penyampaian. Dalam makalah ini, sebuah media pendidikan berbasis audio dengan cara laindiusulkan. Media tersebut bernama radio streaming. Pembuatan radio streaming memerlukan banyak analisissehingga perancangannya tepat. Hasil analisis dan perancangan yang disampaikan dalam makalah ini...

  3. La radio en África. Una radio para el desarrollo

    Directory of Open Access Journals (Sweden)

    Jean-Paul Lafrance

    2015-01-01

    Full Text Available La radio de tipo comunitario, tal como la conocemos en Norteamérica y Europa (no-comercial, no-estatal y particípatíva, no existe en Africa. Sin embargo, la situación histórica y el contexto socio-político particulares de Africa han precedido la instauración de una radio que, dentro del marco del presente estudio, nos ha resultado interesante. Se trata de la radio educativa rural. Aunque enmarcada dentro del molde estatal de regímenes que en su mayoría son dictaduras, la radio rural africana, al igual que las radios de tipo comunitario, utiliza la radio con otros fines además de los convencionales. En este caso, la radio es un instrumento al servicio del desarrollo, por no decir al servicio del campesino, en una relación con éste último que probablemente dejará cada vez más de ser uni-direccional. La experiencia africana nos proporcionará en esta perspectiva nuevos elementos de reflexión en lo que respecta al rol de la radio dentro de la comunidad y sobre las condiciones incluso del éxito o no-éxito de la participación popular.

  4. Planck Early Results. XV. Spectral Energy Distributions and Radio Continuum Spectra of Northern Extragalactic Radio Sources

    Science.gov (United States)

    Aatrokoski, J.; Ade, P. A. R.; Aghanim, N.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Amaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; hide

    2011-01-01

    Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources. based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multi frequency data. The nine Planck frequencies, from 30 to 857 GHz, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data, including the Planck ERCSC data, were calculated. SED modelling methods are discussed, with an emphasis on proper. physical modelling of the synchrotron bump using multiple components. Planck ERCSC data also suggest that the original accelerated electron energy spectrum could be much harder than commonly thought, with power-law index around 1.5 instead of the canonical 2.5. The implications of this are discussed for the acceleration mechanisms effective in blazar shock. Furthermore in many cases the Planck data indicate that gamma-ray emission must originate in the same shocks that produce the radio emission.

  5. Transistor Radio Receivers; Radio and Television Service, Intermediate: 9785.04.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The course outlined is one of the required courses in the Radio and Television Service Curriculum. Mastery of the skills in Basic Radio Circuits and Vacuum Tube AM Troubleshooting (9785.03) is a prerequisite. Eight blocks of instruction are divided into several units each. The instruction blocks are: orientation, fundamentals of transistor…

  6. Contribution to the study of radio toxicity of aromatic and medicinal plants using solid state nuclear track detectors; Contribution a l etude de la radio toxicite des plantes aromatiques et medicinales au moyen des detecteurs solides de traces nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Mortassim, A; Misdaq, M A; Naaman, A

    2009-07-01

    The concentrations of uranium (238 U), thorium (232 Th), radon (222 Rn) and thoron (220 Rn) were measured in twenty aromatic and medicinal plants in {sup f}ind a new method based on using solid state nuclear track detectors type Cr-39 and Rs-115. He emerges from this study that the verbena and salvia have higher levels of uranium (radon) higher than that of other plants while the leaves of olive and saturja have concentrations of thorium (thoron) higher than other plants therefore radio toxicity of these plants is higher than that of others and may pose a radiological hazard if the masses are incorporated by consumers high. [French] Les concentrations en uranium (238U), thorium (232Th), radon (222Rn), et thoron (220Rn) ont ete mesurees dans vingt plantes aromatiques et medicinales en utilsant une nouvelle methode basee sur l utilisation des detecteurs solides de traces nucleaires de types CR-39 et LR-115. Il en sort de cette etude que la verveine et la salvia presentent des teneurs en uranium (radon) superieurs a celle des autres plantes alors que les feuilles d olivier et la saturja presentent des concentrations en thorium (thoron) plus elevee que celles des autres plantes par consequent la radio toxicite de ces plantes est superieure a celles des autres et peuvent presenter un risque radiologique si les masses incorporees par les consommateurs sont elevees.

  7. Contribution to the study of a method for measuring continuously the isotopic effect. The search for an isotopic effect during the reduction of cuprous oxide by a {sup 12}CO - {sup 14}CO mixture (1962); Contribution a l'etude d'une methode de mesure continue de l'effet isotopique. Recherche d'un effet isotopique dans la reduction de l'oxyde cuivreux par le melange {sup 12}CO - {sup 14}CO (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Richard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-15

    The determination of an isotopic effect between the two reactions: {sup 12}CO + Cu{sub 2}O {yields} {sup 12}CO{sub 2} + 2 Cu 'light' reaction {sup 14}CO + Cu{sub 2}O {yields} {sup 14}C{sub O}2 + 2 Cu 'heavy' reaction is possible if the respective kinetics are known. The condensation, during the reaction, of the carbon dioxide formed, and the measurement as a function of time of the residual carbon monoxide pressure, makes it possible to deduce, uninterruptedly, the 'light' reaction kinetics. The 'heavy' reaction kinetics are obtained by measuring continuously, in situ, the radioactivity of the residual reactant gas as a function of the time. The apparatus used for this is a plastic scintillator counter. A calibration curve of the measured radioactivity as a function of the reactant gas pressure in the absence of reaction makes it possible to compare the kinetics of the 'light' and 'heavy' reactions. The reaction temperature is chosen such that the reaction rate is sufficiently slow, so that the variation of the radioactivity during unit counting time is negligible. (author) [French] La determination d'un effet isotopique entre les deux reactions: {sup 12}CO + Cu{sub 2}O {yields} {sup 12}CO{sub 2} + 2 Cu reaction 'legere' {sup 14}CO + Cu{sub 2}O {yields} {sup 14}C{sub O}2 + 2 Cu reaction 'lourde' est rendue possible par la connaissance de leurs cinetiques respectives. La condensation, au cours de la reaction, du gaz carbonique forme et la mesure en fonction du temps de la pression de l'oxyde de carbone residuel, permet d'obtenir, de facon continue, la cinetique de la reaction 'legere'. La cinetique de la reaction lourde est determinee par la mesure continue, in situ, du taux de radioactivite du reactif gazeux residuel en fonction du temps. Le dispositif employe dans ce but est un compteur a scintillateur plastique. Une courbe d'etalonnage, du taux mesure de radioactivite en fonction de la pression du gaz reactif, en l'absence de reaction, permet de comparer les

  8. Apoplejía pituitaria con parálisis del III par craneal: Reporte de caso

    Directory of Open Access Journals (Sweden)

    Miguel Pinto Valdivia

    2011-10-01

    Full Text Available Se describe el caso de un varón de 65 años de edad, sin antecedentes patológicos de importancia, que acudió a emergencia del Hospital Nacional Cayetano Heredia por presentar cefalea intensa y ptosis palpebral izquierda. El examen físico mostró parálisis aislada del III par craneal izquierdo. Los análisis de laboratorio mostraron hiponatremia e hipopituitarismo y la resonancia magnética nuclear un adenoma pituitario con áreas de hemorragia e invasión de los senos cavernosos. El tratamiento incluyó glucocorticoides y descompresión quirúrgica transesfenoidal. La anatomía patológica confirmó el diagnóstico de infarto hemorrágico de un adenoma pituitario. El paciente fue dado de alta con terapia sustitutiva de levotiroxina y prednisona. La ptosis palpebral izquierda se recuperó en forma parcial. La apoplejía pituitaria es un síndrome clínico producido por un proceso expansivo dentro de la silla turca, secundario a hemorragia o infarto de un adenoma pituitario, que se caracteriza por cefalea, déficit visual, oftalmoplejía y alteración del nivel de conciencia. Este proceso expansivo puede comprimir los pares craneales en los senos cavernosos, produciendo diferentes grados de parálisis de los músculos oculomotores. La parálisis aislada del III par craneal es rara.(Rev Med Hered 2011;22:186-189.

  9. Épidémiologie de l'intoxication par envenimation chez les enfants ...

    African Journals Online (AJOL)

    Introduction: L'intoxication par envenimation est l'ensemble des manifestations locales et générales induites par la pénétration dans l'organisme d'une substance toxique produite par un animal venimeux. Le but de notre travail était d'étudier les signes cliniques des intoxications par envenimation chez les enfants de 0 à 15 ...

  10. New radio model in the fourth screen: radiovision, the radio that you can watch

    Directory of Open Access Journals (Sweden)

    Sandra CAVIA FRAILE

    2016-12-01

    Full Text Available The traditional radio is not strange to the social revolution that Internet and new technologies are raising. In recent years, the fourth screen has led the emergence of new models of radio, including Radiovision. The «radio that you can watch» intends to change and innovate the radio broadcasting media to offer a product that meets the multimedia requirements of users. However, currently, the Radiovisión is still at an early stage and it has many aspects that it should improve and care, as the contents and the staging. It is a big chance for the radio that poses challenges and opportunities both for journalism and journalists.

  11. Soluble urokinase plasminogen activator receptor (suPAR) in acute care

    DEFF Research Database (Denmark)

    Rasmussen, Line Jee Hartmann; Ladelund, Steen; Haupt, Thomas Huneck

    2016-01-01

    for age, sex, Charlson score and C reactive protein. Area under the curve for receiver operating characteristics curve analysis of suPAR for 30-day mortality was 0.84 (95% CI 0.81 to 0.86). Furthermore, in the entire cohort, women had slightly higher suPAR compared with men, and suPAR was associated...

  12. Movement and equipositioning of plasmids by ParA filament disassembly

    DEFF Research Database (Denmark)

    Ringgaard, Simon; van Zon, Jeroen; Howard, Martin

    2009-01-01

    , plasmids consistently migrate behind disassembling ParA cytoskeletal structures, suggesting that ParA filaments pull plasmids by depolymerization. The perpetual cycles of ParA assembly and disassembly result in continuous relocation of plasmids, which, on time averaging, results in equidistribution...

  13. Protease-Activated Receptor 4 (PAR4): A Promising Target for Antiplatelet Therapy.

    Science.gov (United States)

    Rwibasira Rudinga, Gamariel; Khan, Ghulam Jilany; Kong, Yi

    2018-02-14

    Cardiovascular diseases (CVDs) are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs), including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR). Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

  14. Protease-Activated Receptor 4 (PAR4: A Promising Target for Antiplatelet Therapy

    Directory of Open Access Journals (Sweden)

    Gamariel Rwibasira Rudinga

    2018-02-01

    Full Text Available Cardiovascular diseases (CVDs are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs, including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR. Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

  15. Par3L enhances colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway

    International Nuclear Information System (INIS)

    Li, Taiyuan; Liu, Dongning; Lei, Xiong; Jiang, Qunguang

    2017-01-01

    Partitioning defective 3-like protein (Par3L) is a recently identified cell polarity protein that plays an important role in mammary stem cell maintenance. Previously, we showed that high expression of Par3L is associated with poor survival in malignant colorectal cancer (CRC), but the underlying mechanism remained unknown. To this end, we established a Par3L knockout colorectal cancer cell line using the CRISPR/Cas system. Interestingly, reduced proliferation, enhanced cell death and caspase-3 activation were observed in Par3L knockout (KO) cells as compared with wildtype (WT) cells. Consistent with previous studies, we showed that Par3L interacts with a tumor suppressor protein liver kinase B1 (Lkb1). Moreover, Par3L depletion resulted in abnormal activation of Lkb1/AMPK signaling cascade. Knockdown of Lkb1 in these cells could significantly reduce AMPK activity and partially rescue cell death caused by Par3L knockdown. Furthermore, we showed that Par3L KO cells were more sensitive to chemotherapies and irradiation. Together, these results suggest that Par3L is essential for colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway, and is a putative therapeutic target for CRC. - Highlights: • Par3L knockout using the CRISPR/Cas system induces apoptosis in colorectal cancer cells. • Par3L interacts with Lkb1 and regulates the activity of AMPK signaling cascade. • Par3L knockout cells are more sensitive to treatment of different chemotherapy drugs and irradiation.

  16. Brésil : La contamination par le mercure en Amazonie | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    11 janv. 2011 ... En tentant de déceler la source de la contamination de l'Amazone par le ... par Jean-Rémy Davy Guimaraes de l'Université fédérale de Rio de Janeiro ... ces mattes est circonscrite par la conservation et la restauration en rive.

  17. Interferometry and synthesis in radio astronomy

    CERN Document Server

    Thompson, A Richard; Swenson Jr , George W

    2017-01-01

    This book is open access under a CC BY-NC 4.0 license. The third edition of this indispensable book in radio interferometry provides extensive updates to the second edition, including results and technical advances from the past decade; discussion of arrays that now span the full range of the radio part of the electromagnetic spectrum observable from the ground, 10 MHz to 1 THz; an analysis of factors that affect array speed; and an expanded discussion of digital signal-processing techniques and of scintillation phenomena and the effects of atmospheric water vapor on image distortion, among many other topics. With its comprehensiveness and detailed exposition of all aspects of the theory and practice of radio interferometry and synthesis imaging, this book has established itself as a standard reference in the field. It begins with an overview of the basic principles of radio astronomy, a short history of the development of radio interferometry, and an elementary discussion of the operation of an interferomete...

  18. Radio Astronomy on and Around the Moon

    Science.gov (United States)

    Falcke, Heino; Klein Wolt, Mark; Ping, Jinsong; Chen, Linjie

    2018-06-01

    The exploration of remote places on other planets has now become a major goal in current space flight scenarios. On the other hand, astronomers have always sought the most remote and isolated sites to place their observatories and to make their most precise and most breath taking discoveries. Especially for radio astronomy, lunar exploration offers a complete new window to the universe. The polar region and the far-side of the moon are acknowledged as unique locations for a low-frequency radio telescope providing scientific data at wavelengths that cannot be obtained from the Earth nor from single satellites. Scientific areas to be covered range from radio surveys, to solar-system studies, exo-planet detection, and astroparticle physics. The key science area, however, is the detection and measurement of cosmological 21 cm hydrogen emission from the still unexplored dark ages of the universe. Developing a lunar radio facility can happen in steps and may involve small satellites, rover-based radio antennas, of free- flying constellations around the moon. A first such step could be the Netherlands-Chinese Long Wavelength Explorer (NCLE), which is supposed to be launched in 2018 as part of the ChangE’4 mission to the moon-earth L2 point.

  19. The Beginnings of Australian Radio Astronomy

    Science.gov (United States)

    Sullivan, Woodruff T.

    The early stages of Australian radio astronomy, especially the first decade after World War II, are described in detail. These include the transition of the CSIRO Radiophysics Laboratory, under the leadership of Joseph Pawsey and Taffy Bowen, from a wartime laboratory in 1945 to, by 1950, the largest and one of the two most important radio astronomy groups in the world (with the Cavendish Laboratory at Cambridge University). The initial solar investigations are described, including discovery of the hot corona and development of the sea-cliff interferometer. During this same period painstaking `radio star' observations by John Bolton and colleagues led to the first suggested optical identifications of Taurus-A (the Crab Nebula), Centaurus-A (NGC 5128), and Virgo-A (M87). The factors that led to the extraordinary early success of the Radiophysics Laboratory are analyzed in detail, followed by discussion of how the situation changed significantly in the second decade of 1955-1965. Finally, the development of major Australian instruments, from the Parkes Radio Telescope (1961) to the Australia Telescope (1988), is briefly presented. This chapter is a direct reprint of the following research paper: Sullivan, W., 2005. The beginnings of Australian radio astronomy. Journal of Astronomical History and Heritage, 8, 11-32.

  20. Latest results of the Tunka Radio Extension

    Directory of Open Access Journals (Sweden)

    Kostunin D.

    2017-01-01

    Full Text Available The Tunka Radio Extension (Tunka-Rex is an antenna array consisting of 63 antennas at the location of the TAIGA facility (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy in Eastern Siberia, nearby Lake Baikal. Tunka-Rex is triggered by the air-Cherenkov array Tunka-133 during clear and moonless winter nights and by the scintillator array Tunka-Grande during the remaining time. Tunka-Rex measures the radio emission from the same air-showers as Tunka-133 and Tunka-Grande, but with a higher threshold of about 100 PeV. During the first stages of its operation, Tunka-Rex has proven, that sparse radio arrays can measure air-showers with an energy resolution of better than 15% and the depth of the shower maximum with a resolution of better than 40 g/cm2. To improve and interpret our measurements as well as to study systematic uncertainties due to interaction models, we perform radio simulations with CORSIKA and CoREAS. In this overview we present the setup of Tunka-Rex, discuss the achieved results and the prospects of mass-composition studies with radio arrays.

  1. Mobile radio alternative systems study traffic model

    Science.gov (United States)

    Tucker, W. T.; Anderson, R. E.

    1983-06-01

    The markets for mobile radio services in non-urban areas of the United States are examined for the years 1985-2000. Three market categories are identified. New Services are defined as those for which there are different expressed ideas but which are not now met by any application of available technology. The complete fulfillment of the needs requires nationwide radio access to vehicles without knowledge of vehicle location, wideband data transmission from remote sites, one- and two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The commercial and public services market of interest to the study is drawn from existing users of mobile radio in non-urban areas who are dissatisfied with the geographical range or coverage of their systems. The mobile radio telephone market comprises potential users who require access to the public switched telephone network in areas that are not likely to be served by the traditional growth patterns of terrestrial mobile telephone services. Conservative, likely, and optimistic estimates of the markets are presented in terms of numbers of vehicles that will be served and the radio traffic they will generate.

  2. Radio on the Other Side of Time

    Directory of Open Access Journals (Sweden)

    Alicia TAPIA LÓPEZ

    2016-06-01

    Full Text Available On October 30, 1938, Orson Welles aired the radio drama The War of the Worlds on the CBS Radio network, adapting the science-fiction novel by the British writer H. G. Wells. During the broadcast, listeners became stricken with panic, believing that the Earth was actually being invaded by giant snake-like Martians launching rays of fire down on humans. Welles was a groundbreaking figure whose trickery exploited the technological novelty of the radio to its fullest, adapting classic texts in ways that exploited the opportunities afforded by this new medium. Over the years, this radio classic has been adapted a number of times, though none has seized on the technological advances of our times. Drawing on the most salient innovations seen in Internet radio, this article creates an imaginary scenario that replicates Orson Welles’s work in the present day, when the Internet has become a channel for broadcasting and hyperlinks have brought different media together. The text is an exploration of the other side of time, where transmedia storytelling facilitates the exchange of stories among consumers, and broadcast programming is no longer linear.

  3. Innovations to enrich science communication through radio

    Directory of Open Access Journals (Sweden)

    Thakar Bhaumik

    2004-12-01

    Full Text Available The Radio is an instrument of communication that has percolated to all the strata of the diverse Indian society. Its position has been consolidated through history as a regular companion and a source of information and entertainment. Its affordability, accessibility and non-reliance on costly resources have ensured its presence in almost all the households. It has become indispensable from kitchens, family rooms and even workspaces. It is one of the few or rather the only medium of communication after the print media wherein information dissemination still is primary and entertainment a secondary requirement, especially the rural areas. The role of radio in rural India is one that demands prominence and hence has been used as a primary resource for various projects on science communication. A majority of the science radio serial listeners are from the rural areas. The radio therefore is an ideal medium for reaching out to the masses. The radio even with its popularity and huge following is lacking in certain aspects that make science communication complete. Manthan Educational Programme Society developed concepts to make these efforts more effective by ensuring higher involvement and interest in these programs.

  4. Russian Speech in Radio: Norm and Deviation

    Directory of Open Access Journals (Sweden)

    Igor V. Nefedov

    2017-06-01

    Full Text Available National radio, like television, is called upon to bring to the masses not only relevant information, but also a high culture of language. There were always serious demands to oral public speech from the point of view of the correctness and uniformity of the pronunciation. However, today the analysis of the language practice of broadcasting often indicates a discrepancy between the use of linguistic resources in existing literary norms. The author of the article from the end of December 2016 to early April 2017 listened and analyzed from the point of view of language correctness the majority of programs on the radio Komsomolskaya Pravda (KP. In general, recognizing the good speech qualification of the workers of this radio, as well as their «guests» (political scientists, lawyers, historians, etc., one can not but note the presence of a significant number of errors in their speech. The material presented in the article allows us to conclude that at present, broadcasting is losing its position in the field of speech culture. Neglect of the rules of the Russian language on the radio «Komsomolskaya Pravda» negatively affects the image of the Russian language, which is formed in the minds of listeners. The language of radio should strive to become a standard of cleanliness and high culture for the population, since it has the enormous power of mass impact and supports the unity of the cultural and linguistic space.

  5. Radio emission from embryonic superluminous supernova remnants

    Science.gov (United States)

    Omand, Conor M. B.; Kashiyama, Kazumi; Murase, Kohta

    2018-02-01

    It has been widely argued that Type-I superluminous supernovae (SLSNe-I) are driven by powerful central engines with a long-lasting energy injection after the core-collapse of massive progenitors. One of the popular hypotheses is that the hidden engines are fast-rotating pulsars with a magnetic field of B ˜ 1013-1015 G. Murase, Kashiyama & Mészáros proposed that quasi-steady radio/submm emission from non-thermal electron-positron pairs in nascent pulsar wind nebulae can be used as a relevant counterpart of such pulsar-driven supernovae (SNe). In this work, focusing on the nascent SLSN-I remnants, we examine constraints that can be placed by radio emission. We show that the Atacama Large Millimeter/submillimetre Array can detect the radio nebula from SNe at DL ˜ 1 Gpc in a few years after the explosion, while the Jansky Very Large Array can also detect the counterpart in a few decades. The proposed radio follow-up observation could solve the parameter degeneracy in the pulsar-driven SN model for optical/UV light curves, and could also give us clues to young neutron star scenarios for SLSNe-I and fast radio bursts.

  6. Biological Monitoring for Plutonium-241; Detection du Plutonium-241 par Controles Biologiques; Dozimetriya Plutoniya-241 v biologicheskikh materialakh; Determinacion del Plutonio-241 en Sustancias Biologicas

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, J. C.; McDonald, B. J.; Barnes, V. [United Kingdom Atomic Energy Authority, Windscale Works, Sellafield (United Kingdom)

    1965-10-15

    ) [French] Les auteurs indiquent l'origine et les caracteristiques du {sup 241}Pu, en examinant plus particulierement les risques qu'il presente pour la sante et le probleme que pose son dosage. Ils decrivent un systeme de comptage, qui est en voie d'elaboration a Windscale, pour doser de petites quantites de {sup 241}Pu dans des echantillons preleves dans le cadre d'un programme de controle biologique. Au stade actuel de sa mise au point, cette methode est pour le moins aussi sensible que les procedes signales anterieurement et elle est plus simple, plus rapide et plus rentable. Elle est essentiellement destinee aux analyses d'urine en vue de completer les renseignements deja obtenus par analyse autoradiographique des isotopes emetteurs alpha du plutonium. Le meme porte-source est utilise pour le dosage du {sup 241}Pu, ce qui permet d'eviter certains travaux preparatoires. A l'aide d'une methode fondee sur l'echange d'anions, les isotopes du plutonium sont tout d'abord separes de l'echantillon d'urine ou de toute autre matiere biologique, dans un etat de grandepurete radiochimique. Puis on les fixe par electrolyse sur un disque en acier inoxydable. Un systeme de comptage par anticoiencidence comportant un compteur proportionnel de faible volume a circulation continue de gaz et muni d'une garde anticoiencidence a scintillation en matiere plastique permet de determiner directement le spectre beta mou du {sup 241}Pu (energie maximale 20 keV, periode 13,3 a). Les dimensions sont telles que toutes les particules beta emises par le plutonium sont absorbees a l'interieur du compteur proportionnel alors que les particules alpha perdent 50% environ de leur energie dans le scintillateur en matiere plastique. Pour les deux rayonnements, la geometrie est pratiquement 2{pi}. A son stade actuel, le materiel permet de detecter 3 pCi de {sup 241}Pu en 1 h de comptage. Cela correspond au taux d'excretion urinaire de 24 h trois mois apres l'absorption d'environ 5% de la charge corporelle

  7. Sounds energetic: the radio producer's energy minibook

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The Minibook will be expanded into the final Radio Producer's Energy Sourcebook. Radio producers and broadcasters are asked to contribute ideas for presenting energy knowledge to the public and to be included in the Sourcebook. Chapter One presents a case study suggesting programming and promotion ideas and sample scripts for a radio campaign that revolves around no-cost or low-cost steps listeners can take to increase their home energy efficiency and save money. A variety of other energy topics and suggestions on ways to approach them are addressed in Chapter Two. Chapter Three contains energy directories for Baltimore, Philadelphia, Pittsburg, and Washington, DC. The directories will be expanded in the Sourcebook and will consist of a selection of local public and private sector energy-related organizations and list local experts and organizations and the best Federal, state, and local government programs that can provide consumers and citizens groups with information, technical assistance, and financial support. (MCW)

  8. Advertising Radio Discourse – Lexical Analysis

    Directory of Open Access Journals (Sweden)

    Dumitrascu Elena

    2017-01-01

    Full Text Available Radio advertising, although it seems to be the "poor relative" on the advertising market, is avery interesting topic of study, because it uses language to a very large extent. In a relatively shorttime, a maximum of information is transmitted that causes emotions and raises the interest of asmany people as possible for a product or brand, all wrapped up in a coherent text of 60 to 100words . In radio advertising, the text is the one that has priority, being the star because themessage is based on the text. For this reason, radio discourse may be a research object of interestto linguists, and this has led us to pay close attention to it.

  9. Reconfigurable, Cognitive Software-Defined Radio

    Science.gov (United States)

    Bhat, Arvind

    2015-01-01

    Software-defined radio (SDR) technology allows radios to be reconfigured to perform different communication functions without using multiple radios to accomplish each task. Intelligent Automation, Inc., has developed SDR platforms that switch adaptively between different operation modes. The innovation works by modifying both transmit waveforms and receiver signal processing tasks. In Phase I of the project, the company developed SDR cognitive capabilities, including adaptive modulation and coding (AMC), automatic modulation recognition (AMR), and spectrum sensing. In Phase II, these capabilities were integrated into SDR platforms. The reconfigurable transceiver design employs high-speed field-programmable gate arrays, enabling multimode operation and scalable architecture. Designs are based on commercial off-the-shelf (COTS) components and are modular in nature, making it easier to upgrade individual components rather than redesigning the entire SDR platform as technology advances.

  10. Indoor Positioning with Radio Location Fingerprinting

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    . A promising indoor positioning technique is radio-based location ngerprinting, having the major advantage of exploiting already existing radio infrastructures, like IEEE 802.11 or GSM, which avoids extra deployment costs and eort. The research goal of this thesis is to address the limitations of current...... indoor location ngerprinting systems. In particular the aim is to advance location ngerprinting techniques for the challenges of handling heterogeneous clients, scalability to many clients, and interference between communication and positioning. The wireless clients used for location ngerprinting...... are heterogeneous even when only considering clients for the same technology. The heterogeneity is due to dierent radios, antennas, and rmwares causing measurements for location ngerprinting not to be directly comparable among clients. Heterogeneity is a challenge for location ngerprinting because it severely...

  11. FM Radio and Youth: Listeners or Users?

    Directory of Open Access Journals (Sweden)

    Marina Mučalo

    2014-06-01

    Full Text Available A survey conducted in the spring of 2013, says that Zagreb’s high school students are not regular listeners to FM radio programs. The dominant media is the Internet, which is used a few hours a day, mostly for Facebook. Despite the expressed need for music, the linear and passive nature of FM radio, does not correspond to the individual requirements of young and networked users. The Internet is the most popular daily source for music, with ability to download, while smartphones are becoming devices for storage and playback. However, this survey has shown that students are interested in web radio sites. Changes in media preferences and habits caused by the Internet show us the importance of information literacy, as a basic skill for participation in a networked society.

  12. Cryoconite. An exotic radio-ecological delicacy

    International Nuclear Information System (INIS)

    Tieber, A.; Wilflinger, T.; Lettner, H.; Hubmer, A.K.; Bossew, P.; Sattler, B.

    2009-01-01

    Five years of research on the radio-ecology of cryconite, a sediment of mineral and organic compounds found on glacier surfaces and within glacier ice, has led to amazing insights into the properties of an environmental medium which has been neglegted almost completely previously. It has turned out that a surprising radio-ecological diversity exists on and within glaciers, apart from their quality as thrieving biotopes, also not known for long. This presentation summarizes results from different research projects related to high-Alpine radio-ecology: radionuclide inventories and spatial distributions of cryoconite, hypotheses about their origin and formation, their cycling on and within glaciers, and their role in glacier melting due to global warming. (orig.)

  13. Gamma-Ray Bursts: A Radio Perspective

    Directory of Open Access Journals (Sweden)

    Poonam Chandra

    2016-01-01

    Full Text Available Gamma-ray bursts (GRBs are extremely energetic events at cosmological distances. They provide unique laboratory to investigate fundamental physical processes under extreme conditions. Due to extreme luminosities, GRBs are detectable at very high redshifts and potential tracers of cosmic star formation rate at early epoch. While the launch of Swift and Fermi has increased our understanding of GRBs tremendously, many new questions have opened up. Radio observations of GRBs uniquely probe the energetics and environments of the explosion. However, currently only 30% of the bursts are detected in radio bands. Radio observations with upcoming sensitive telescopes will potentially increase the sample size significantly and allow one to follow the individual bursts for a much longer duration and be able to answer some of the important issues related to true calorimetry, reverse shock emission, and environments around the massive stars exploding as GRBs in the early Universe.

  14. Radio continuum observations of NML Cygni

    International Nuclear Information System (INIS)

    Gregory, P.C.; Seaquist, E.R.

    1976-01-01

    An attempt to detect thermal radio emission from a compact circumstellar cloud about the infrared star NML Cyg has been carried out at three frequencies, 2.7, 8.1, and 10.5 GHz. Although positive results were obtained with single-dish observations at 10.5 GHz, the radio emission is not from a circumstellar cloud about NML Cyg. Instead it is postulated that the emission is from an H ii region with an angular extent of approx.2'. The red print of the Sky Survey shows a faint nebulosity of comparable angular size overlapping the star's position, lending support to this interpretation. The interferometer observations at 2.7 and 8.1 GHz provide an upper limit on the radio emission from any compact circumstellar cloud about NML Cyg of 2.8 mJy, which is well below the flux density expected for the absorbing cloud postulated by Davies et al. (1972)

  15. Biodiversity Loss in the Orion Radio Zoo?

    Science.gov (United States)

    Henney, W. J.; García-Díaz, Ma. T.; Kurtz, S. E.

    2001-03-01

    We re-examine radio observations of compact sources in the core of the Orion nebula and find that 70% of the sources correspond to known proplyds. For all of these sources, including many that have been previously classified as variable and non-thermal, the radio flux between 1.5 and 86 Ghz is fully accounted for by thermal free-free emission from the photoevaporation flow. We therefore suggest that many of the proposed Orion FOXES are in fact EIDERS, and that their apparent variability reflects observational difficulties in detecting the lower surface-brightness portions of the proplyds. The PIGs turn out to be extinct in Orion, and the hybrid creatures that we dub PANTHERS (Proplyds Associated with Non-THErmal Radio Sources) remain elusive.

  16. La syphilis congenitale revelee par une fracture spontanee

    Directory of Open Access Journals (Sweden)

    Mounia Lakhdar Idrissi

    2011-11-01

    Full Text Available Alors qu�elle est actuellement oubliee dans les pays developpes, la syphilis congenitale se voit encore chez nous faute du depistage antenatal. Ses formes cliniques sont polymorphes et orientent a tord vers d�autres pathologies surtout en periode neonatale. Le diagnostic n�est donc pas toujours facile. La revelation d�une syphilis congenitale par une fracture spontanee est exceptionnellement decrite. Nous rapportons dans ce travail le cas d�un nourrisson de 2 mois ramene en consultation pour limitation douloureuse des mouvements du bras droit. Le diagnostic est evoque sur les donnees radiologiques et confirme par la serologie syphilitique. Le traitement a repose essentiellement sur l�administration de la penicilline G avec une bonne evolution clinique.

  17. Results of Preliminary Tests of PAR Bunch Cleaning

    CERN Document Server

    Yao, Chihyuan; Grelick, Arthur; Lumpkin, Alex H; Sereno, Nicholas S

    2005-01-01

    A particle accumulator ring (PAR) is used at the Advanced Photon Source (APS) to collect multiple linac bunches and compress them into a 0.3-ns (rms) single bunch for booster injection. A 9.77-MHz fundamental rf system and a 117.3-MHz harmonic rf system are employed for initial beam capture and bunch length compression. Satellite bunches with very low charge form due to rf phase drifts or beam loading change. These satellites, when injected into the booster and then into the storage ring (SR), cause bunch impurity at three buckets from the target bucket. Storage ring and booster bunch cleaning was tried but proved to be difficult due to the top-up mode of operation in the storage ring and tune drift in the booster synchrotron. Recently we implemented a PAR bunch-cleaning system with tune-modulated harmonic rf knockout. Preliminary tests gave a measured SR bunch purity of better than 10

  18. Avis 6 sur la formation à et par la recherche

    OpenAIRE

    Centre de Coopération Internationale en Recherche Agronomique pour le Développement

    2015-01-01

    La formation à et par la recherche s’appuie sur la démarche scientifique, les savoirs, les connaissances à transmettre, tout autant que l’acquisition de compétences en gestion de projet, de capacités au travail en équipe, d’une ouverture d’esprit qui favorisera la créativité. Elle doit permettre de prendre conscience de la responsabilité endossée par la communauté scientifique vis-à-vis de la société et de l’environnement, mais aussi préparer l’avenir professionnel de celle ou de celui qu...

  19. Evaluation of the Stability After Orthodontic Treatment Using PAR Index

    Directory of Open Access Journals (Sweden)

    Chaitra Ramanathan

    2006-01-01

    Full Text Available The aim of the present study is to establish the results using the scores obtained from the methodology that was applied for assessing the stability after 2 years post orthodontic treatment and stability in a sample of 69 individuals. After applying PAR index to the collected group of patients, a series of scores were obtained, which were then needed to be evaluated further to establish the results. The scores were evaluated using the nomogram. A comparison was done between the post treatment and the 2 years post treatment PAR weighting scores to determine if the results were stable after orthodontic treatment. The majority of the orthodontic patients were treated to a good standard and that the results appeared to be stable.

  20. Are the infrared-faint radio sources pulsars?

    Science.gov (United States)

    Cameron, A. D.; Keith, M.; Hobbs, G.; Norris, R. P.; Mao, M. Y.; Middelberg, E.

    2011-07-01

    Infrared-faint radio sources (IFRS) are objects which are strong at radio wavelengths but undetected in sensitive Spitzer observations at infrared wavelengths. Their nature is uncertain and most have not yet been associated with any known astrophysical object. One possibility is that they are radio pulsars. To test this hypothesis we undertook observations of 16 of these sources with the Parkes Radio Telescope. Our results limit the radio emission to a pulsed flux density of less than 0.21 mJy (assuming a 50 per cent duty cycle). This is well below the flux density of the IFRS. We therefore conclude that these IFRS are not radio pulsars.

  1. Real-Time Measurements for Adaptive and Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Hüseyin Arslan

    2009-01-01

    Full Text Available Adaptive and cognitive radios (CR have been becoming popular for optimizing mobile radio system transmission and reception. One of the most important elements of the adaptive radio and CR concepts is the ability to measure, sense, learn about, and be aware of parameters related to the radio channel characteristics, availability of spectrum and power, interference and noise temperature, operational environment of radio, user requirements and applications, available networks and infrastructures, local policies, other operating restrictions, and so on. This paper discusses some of the important measurement parameters for enabling adaptive radio and CR systems along with their relationships and impacts on the performance including relevant challenges.

  2. More of the Same - On Spotify Radio

    Directory of Open Access Journals (Sweden)

    Pelle Snickars

    2017-10-01

    Full Text Available Spotify Radio allows users to find new music within Spotify's vast back-catalogue, offering a potential infinite avenue of discovery. Nevertheless, the radio service has also been disliked and accused of playing the same artists over and over. We decided to set up an experiment with the purpose to explore the possible limitations found within 'infinite archives' of music streaming services. Our hypothesis was that Spotify Radio appears to consist of an infinite series of songs. It claims to be personalised and never-ending, yet music seems to be delivered in limited loop patterns. What would such loop patterns look like? Are Spotify Radio's music loops finite or infinite? How many tracks (or steps does a normal loop consist of? To answer these research questions, at Umeå University's digital humanities hub, Humlab, we set up an intervention using 160 bot listeners. Our bots were all Spotify Free users. They literally had no track record and were programmed to listen to different Swedish music from the 1970s. All bots were to document all subsequent tracks played in the radio loop and (interact within the Spotify Web client as an obedient bot listener, a liker, a disliker, and a skipper. The article describes different research strategies when dealing with proprietary data. Foremost, however, it empirically recounts the radio looping interventions set up at Humlab. Essentially, the article suggests a set of methodologies for performing humanist inquiry on big data and black-boxed media services that increasingly provide key delivery mechanisms for cultural materials. Spotify serves as a case in point, yet principally any other platform or service could be studied in similar ways. Using bots as research informants can be deployed within a range of different digital scholarship, so this article appeals not only to media or software studies scholars, but also to digitally inclined cultural studies such as the digital humanities.

  3. La parálisis cerebral en el contexto escolar /

    OpenAIRE

    González Vara, Azucena

    2012-01-01

    Se analiza el concepto de parálisis cerebral, los diferentes tipos y sus características. También las adaptaciones que se deben realizar a nivel de centro, de aula, y a nivel individual para estos alumnos, conocer los diferentes sistemas alternativos y aumentativos de comunicación y aplicar las ayudas técnicas que precisa este alumnado

  4. Tuberculose lymphonodale cervicale chez les enfants vaccines par ...

    African Journals Online (AJOL)

    La tuberculose ganglionnaire cervicale est une localisation extrapulmonaire relativement fréquente chez l'enfant. Elle pose essentiellement des difficultés de prévention. L'objectif de ce travail est d'étudier les particularités diagnostiques et thérapeutiques chez des enfants vaccinés par le BCG. Matériel et méthodes: Nôtre ...

  5. Traitement De La Peripneumonie Contagieuse Bovine Par L ...

    African Journals Online (AJOL)

    Traitement De La Peripneumonie Contagieuse Bovine Par L'oxyteTracycline Longe Action Et Transmission Experimentale de la Maladie A Partir de Bovins Traites. ... Tous les 14 animaux ont séroconverti et l'analyse post-mortem a montré la présence des lésions chroniques dont des séquestres pulmonaires chez 4 d'entre ...

  6. Adoption d'innovations agricoles par le truchement de services ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'agriculture est le fer de lance de nombreuses économies en développement, mais la capacité des petits agriculteurs privés de ressources à adopter des innovations agricoles est freinée par le manque d'accès à des services financiers adéquats. Des experts internationaux estiment qu'il existe un manque à gagner ...

  7. Candido: Uma Leitura Paródica de Candide

    Directory of Open Access Journals (Sweden)

    Maria Gloria Cusumano Mazzi

    2010-12-01

    Full Text Available O presente artigo estuda a leitura paródica que Leonardo Sciascia (1921-1989 faz de Voltaire (1694-1778 mediante o cotejo das obras: o hipertexto Candido ovvero Un sogno fatto in Sicilia (1977 e o hipotexto Candide ou l’optimisme (1759. Apresenta ainda outra possibilidade de leitura, ou seja, Candido como metáfora da própria intertextualidade.

  8. Solution volumes finis polynomiale par morceaux pour les ...

    African Journals Online (AJOL)

    Nous présentons dans ce papier un concept de solution volumes finis continue pour des problèmes de diffusion-convection avec des données régulières. Nous comparons dans certains cas particuliers la solution proposée avec la solution volumes finis classiques (qui est une fonction constante par morceaux) et la ...

  9. Giant Metrewave Radio Telescope Observations of Head–Tail Radio Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, Biny; Lal, Dharam V.; Rao, A. Pramesh, E-mail: biny@ncra.tifr.res.in [National Center for Radio Astrophysics—Tata Institute of Fundamental Research Post Box 3, Ganeshkhind P.O., Pune 41007 (India)

    2017-10-01

    We present results from a study of seven large known head–tail radio galaxies based on observations using the Giant Metrewave Radio Telescope at 240 and 610 MHz. These observations are used to study the radio morphologies and distribution of the spectral indices across the sources. The overall morphology of the radio tails of these sources is suggestive of random motions of the optical host around the cluster potential. The presence of multiple bends and wiggles in several head–tail sources is possibly due to the precessing radio jets. We find steepening of the spectral index along the radio tails. The prevailing equipartition magnetic field also decreases along the radio tails of these sources. These steepening trends are attributed to the synchrotron aging of plasma toward the ends of the tails. The dynamical ages of these sample sources have been estimated to be ∼10{sup 8} yr, which is a factor of six more than the age estimates from the radiative losses due to synchrotron cooling.

  10. Radio universitaria: trabajo en red como imperativo

    Directory of Open Access Journals (Sweden)

    Tiziana Cavallo

    2014-01-01

    Full Text Available Trabajo en red es un concepto clave en la radio universitaria, tanto desde el punto de vista individual como del colectivo. A través de dos estudios de caso, enfocados en la radio universitaria de Italia y de Colombia, este artículo muestra cómo el trabajo en red ha sido decisivo para el fortalecimiento de su función, la ampliación de su impacto, la conformación de su identidad y el crecimiento de su visibilidad en las sociedades en las cuales desarrollan su labor.

  11. Radio resource allocation and dynamic spectrum access

    CERN Document Server

    Benmammar , Badr

    2013-01-01

    We are currently witnessing an increase in telecommunications norms and standards given the recent advances in this field. The increasing number of normalized standards paves the way for an increase in the range of services available for each consumer. Moreover, the majority of available radio frequencies have already been allocated. This explains the emergence of cognitive radio (CR) - the sharing of the spectrum between a primary user and a secondary user.In this book, we will present the state of the art of the different techniques for spectrum access using cooperation and competit

  12. On making radio contact with extraterrestrial civilizations

    International Nuclear Information System (INIS)

    Bates, D.R.

    1978-01-01

    The problem of attempting to make radio contact with other technological civilizations is examined. It is argued that there are few (perhaps indeed no) omnidirectional radio beacons in the Galaxy primarily because any such beacon, to be effective, would have to be designed for a call-response time of at least some 10 4 years, which is much too long to be likely to be acceptable to governments. A consequence is that any search program by us would have little chance of detecting incoming signals. (Auth.)

  13. Baseline-dependent averaging in radio interferometry

    Science.gov (United States)

    Wijnholds, S. J.; Willis, A. G.; Salvini, S.

    2018-05-01

    This paper presents a detailed analysis of the applicability and benefits of baseline-dependent averaging (BDA) in modern radio interferometers and in particular the Square Kilometre Array. We demonstrate that BDA does not affect the information content of the data other than a well-defined decorrelation loss for which closed form expressions are readily available. We verify these theoretical findings using simulations. We therefore conclude that BDA can be used reliably in modern radio interferometry allowing a reduction of visibility data volume (and hence processing costs for handling visibility data) by more than 80 per cent.

  14. Optical images of quasars and radio galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, J.B.; Johnson, I.; Pyke, R.

    1988-04-01

    Matched contour plots and gray-scale diagrams are presented for 54 radio quasars or radio galaxies of redshift 0.1-0.6, observed with the Canada-France-Hawaii Telescope. All except four were recorded on the RCA1 CCD chip; four were summed from several photographic exposures behind an image tube. All except nine of the objects form the principal data base used by Hutchings (1987). Detailed comments are given on all objects, and some further measures of the objects and their companions. 12 references.

  15. Optical images of quasars and radio galaxies

    International Nuclear Information System (INIS)

    Hutchings, J.B.; Johnson, I.; Pyke, R.

    1988-01-01

    Matched contour plots and gray-scale diagrams are presented for 54 radio quasars or radio galaxies of redshift 0.1-0.6, observed with the Canada-France-Hawaii Telescope. All except four were recorded on the RCA1 CCD chip; four were summed from several photographic exposures behind an image tube. All except nine of the objects form the principal data base used by Hutchings (1987). Detailed comments are given on all objects, and some further measures of the objects and their companions. 12 references

  16. Optical images of quasars and radio galaxies

    Science.gov (United States)

    Hutchings, J. B.; Johnson, I.; Pyke, R.

    1988-04-01

    Matched contour plots and gray-scale diagrams are presented for 54 radio quasars or radio galaxies of redshift 0.1-0.6, observed with the Canada-France-Hawaii Telescope. All except four were recorded on the RCA1 CCD chip; four were summed from several photographic exposures behind an image tube. All except nine of the objects form the principal data base used by Hutchings (1987). Detailed comments are given on all objects, and some further measures of the objects and their companions.

  17. Radio images of the interplanetary turbulent plasma

    International Nuclear Information System (INIS)

    Vlasov, V.I.

    1979-01-01

    The results of the interplanetary scintillation daily observations of approximately 140 radio sources are given. The observations were carried out at the radiotelescope VLPA FIAN during 24 days in October-November 1975 and 6 days in April 1976. The maps (radio images) of interplanetary turbulent plasma are presented. The analysis of the maps reveals the presence of large-scale irregularities in the interplanetary plasma. The variability in large-scale structure of the interplanetary plasma is due mainly to transport of matter from the Sun. A comparison of the scintillation with the geomagnetic activity index detected the presence of a straight connection between them

  18. Radio Observations of Gamma-ray Novae

    Science.gov (United States)

    Linford, Justin D.; Chomiuk, L.; Ribeiro, V.; project, E.-Nova

    2014-01-01

    Recent detection of gamma-ray emission from classical novae by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope surprised many in the astronomical community. We present results from radio observations, obtained using the Karl G. Jansky Very Large Array (VLA), of three gamma-ray novae: Mon2012, Sco2012, and Del2013. Radio observations allow for the calculation of ejecta masses, place limits on the distances, and provide information about the gamma-ray emission mechanism for these sources.

  19. HF Radio Astronomy from a Small Satellite

    Science.gov (United States)

    2016-06-15

    SSC16-XI-03 HF Radio Astronomy from a Small Satellite Frank C. Robey1, Mary Knapp2, Alan J. Fenn1, Mark Silver1, Kerry Johnson1 Frank J. Lind3...frequency end of the electromagnetic spectrum (below 15 MHz) is one of the least explored windows in observational astronomy . Observations at these...pdf. [Accessed: 17-Oct-2015]. 3. G. Hallinan, “The Owens Valley LWA,” in Exascale Radio Astronomy , 2014, vol. 2. 4. C. J. Lonsdale, R. J. Cappallo

  20. Solar system radio astronomy at low frequencies

    International Nuclear Information System (INIS)

    Desch, M.D.

    1987-01-01

    The planetary radio-astronomy observations obtained with the two Voyager spacecraft since their launch in 1977 are briefly characterized and illustrated with graphs, diagrams, and sample spectra. Topics addressed include the spacecraft designs and trajectories, the wavelength coverage of the radio instruments, the Io-controlled LF emission of Jupiter, the solar-wind effect on the Saturn kilometric radiation, the Saturn electrostatic discharges, and the use of the clocklike feature of the Uranus emission to measure the planet's rotation period. 23 references

  1. Radio propagation through the turbulent interstellar plasma

    International Nuclear Information System (INIS)

    Rickett, B.J.

    1990-01-01

    The current understanding of interstellar scattering is reviewed, and its impact on radio astronomy is examined. The features of interstellar plasma turbulence are also discussed. It is concluded that methods involving the investigation of the flux variability of pulsars and extragalactic sources and the VLBI visibility curves constitute new techniques for probing the ISM. However, scattering causes a seeing limitation in radio observations. It is now clear that variation due to RISS (refractive interstellar scintillations) is likely to be important for several classes of variable sources, especially low-frequency variables and centimeter-wave flickering. 168 refs

  2. Reflection jets and collimation of radio sources

    International Nuclear Information System (INIS)

    Pacholczyk, A.G.

    1983-01-01

    A discussion of the hydrodynamics of jets formed by discrete portions of materials ejected from the parent galaxy through a channel, and reflected back to it as a result of an encounter with the material accumulated at the end of the channel, is the basis of the present descriptive hypothesis for a class of jets in extended radio sources. The model encompasses the view of extended radio sources as the multiple ejection of plasmoids through a channel, as well as the formation of retrojets through the interaction of a plasmon with the dense relic material at the end of a channel, and the collimation of plasmon material in channels. 14 references

  3. Electronic analogue simulator of radio cardiograms

    International Nuclear Information System (INIS)

    Roux, G.; Lansiart, A.; Vernejoul, P. de; Kellershohn, C.

    1967-01-01

    The various parameters of the heart pump and of the blood circulation can be determined by radio-cardio-graphical techniques. The curves thus obtained can be more easily used in radiocardiography if the electronic analogue simulator described here is employed. The experimental and simulated radio-cardiograms are made to coincide by varying the electrical parameters of the simulator. Using simple charts it is possible to obtain directly the actual original physiological parameters from these electrical parameters. Some examples are given showing the excellent accuracy obtained in the determination of ejection indices by the simulator. (authors) [fr

  4. RADIO SOURCE FEEDBACK IN GALAXY EVOLUTION

    International Nuclear Information System (INIS)

    Shabala, Stanislav; Alexander, Paul

    2009-01-01

    We present a galaxy evolution model which incorporates a physically motivated implementation of active galactic nucleus feedback. Intermittent jets inflate cocoons of radio plasma which then expand supersonically, shock heating the ambient gas. The model reproduces observed star formation histories to the highest redshifts for which reliable data exist, as well as the observed galaxy color bimodality. Intermittent radio source feedback also naturally provides a way of keeping the black hole and spheroid growth in step. We find possible evidence for a top-heavy initial mass function for z > 2, consistent with observations of element abundances, and submillimeter and Lyman break galaxy counts.

  5. Surveys of radio sources at 5 GHz

    International Nuclear Information System (INIS)

    Pauliny-Toth, I.I.K.

    1977-01-01

    A number of surveys have been carried out at a frequency of 5 GHz at the National Radio Astronomy Observatory (NRAO) and at the Max-Planck-Institut fuer Radioastronomy (MPIFR) with the aim of determining the number-flux density relation for the sources detected and also of obtaining their radio spectra and optical identifications. The surveys fall into two categories: first, the strong source (S) surveys which are intended in due course to cover the whole northern sky and to be complete above a flux density of about 0.6 Jy; second, surveys of limited areas of sky down to lower levels of the flux density. (Auth.)

  6. ARTIP: Automated Radio Telescope Image Processing Pipeline

    Science.gov (United States)

    Sharma, Ravi; Gyanchandani, Dolly; Kulkarni, Sarang; Gupta, Neeraj; Pathak, Vineet; Pande, Arti; Joshi, Unmesh

    2018-02-01

    The Automated Radio Telescope Image Processing Pipeline (ARTIP) automates the entire process of flagging, calibrating, and imaging for radio-interferometric data. ARTIP starts with raw data, i.e. a measurement set and goes through multiple stages, such as flux calibration, bandpass calibration, phase calibration, and imaging to generate continuum and spectral line images. Each stage can also be run independently. The pipeline provides continuous feedback to the user through various messages, charts and logs. It is written using standard python libraries and the CASA package. The pipeline can deal with datasets with multiple spectral windows and also multiple target sources which may have arbitrary combinations of flux/bandpass/phase calibrators.

  7. Radio Frequency Fragment Separator at NSCL

    International Nuclear Information System (INIS)

    Bazin, D.; Andreev, V.; Becerril, A.; Doleans, M.; Mantica, P.F.; Ottarson, J.; Schatz, H.; Stoker, J.B.; Vincent, J.

    2009-01-01

    A new device has been designed and built at NSCL which provides additional filtering of radioactive beams produced via projectile fragmentation. The Radio Frequency Fragment Separator (RFFS) uses the time micro structure of the beams accelerated by the cyclotrons to deflect particles according to their time-of-flight, in effect producing a phase filtering. The transverse RF (Radio Frequency) electric field of the RFFS has superior filtering performance compared to other electrostatic devices, such as Wien filters. Such filtering is critical for radioactive beams produced on the neutron-deficient side of the valley of stability, where strong contamination occurs at intermediate energies from 50 to 200 MeV/u.

  8. Radio-frequency integrated-circuit engineering

    CERN Document Server

    Nguyen, Cam

    2015-01-01

    Radio-Frequency Integrated-Circuit Engineering addresses the theory, analysis and design of passive and active RFIC's using Si-based CMOS and Bi-CMOS technologies, and other non-silicon based technologies. The materials covered are self-contained and presented in such detail that allows readers with only undergraduate electrical engineering knowledge in EM, RF, and circuits to understand and design RFICs. Organized into sixteen chapters, blending analog and microwave engineering, Radio-Frequency Integrated-Circuit Engineering emphasizes the microwave engineering approach for RFICs. Provide

  9. Ecuador: La experiencia de Radio Latacunga

    Directory of Open Access Journals (Sweden)

    David Silva

    2015-01-01

    Full Text Available En Latacunga - Ecuador es entrevistada Lucelly Villa, de la comunidad Hijas de San Pablo, "Hermanas Paulinas", ella es directora de la Radio y presidenta de la CORAPE (Coordinadora de Radios Populares y Educativas de Ecuador. En la entrevista comenta la experiencia de las emisoras en las zonas campesinas de la provincia cuya población indígena campesina esta geográficamente dispersa en la provincia de Cotopaxi. Habla de las dificultades y logros en once años de labor, informa de cómo funcionan las cabinas y la programación.

  10. Preliminary Analysis For Wolsong Par Effects Using ISACC Calculations

    International Nuclear Information System (INIS)

    Song, Yong Mann; Kim, Dong Ha

    2012-01-01

    In the paper, hydrogen control effects using PARs only are analyzed for severe SBO station blackout (SBO) sequences beyond the design basis accidents in WS-1 which are of CANDU6 type reactor. As a computational tool, the latest version of ISAAC4.3 (Integrated Severe Accident Analysis Code for CANDU), which is a fully integrated and lumped severe accident computer code, is used to simulate hydrogen generation and transport inside the reactor building (R/B) before its failure. For the performance of hydrogen removal, the depletion rate equation of K-PAR developed in Korea is applied. In a CANDU reactor, three areas are identified as sources of hydrogen under severe accidents: fuel-coolant interactions in intact channels, suspended fuel or debris interactions in-calandria tank and debris interactions in-calandria vault. The first two origins provide source for the late ('late' terminology is used because it takes more than one day before calandria tank failure) potential hydrogen combustion before calandria tank failure and all the three origins would provide source for the very late potential hydrogen combustion occurring at or after calaria tank failure. If the hydrogen mitigation system fails, the AICC (adiabatic isochoric complete combustion) burning of highly flammable hydrogen may cause Wolsong R/B failure. So hydrogen induced failure possibility is evaluated, using preliminary ISAAC calculations, under several SBO conditions with and without PAR for both late and very late accident periods

  11. Protease activated receptors (PARS) mediation in gyroxin biological activity

    International Nuclear Information System (INIS)

    Silva, Jose Alberto Alves da

    2009-01-01

    Gyroxin is a serine protease enzyme from the South American rattlesnake (Crotalus durissus terrificus) venom; it is only partially characterized and has multiple activities. Gyroxin induces blood coagulation, blood pressure decrease and a neurotoxic behavior named barrel rotation. The mechanisms involved in this neurotoxic activity are not known. Whereas gyroxin is a member of enzymes with high potential to become a new drug with clinical applications such as thrombin, batroxobin, ancrod, tripsyn and kalicrein, it is important to find out how gyroxin works. The analysis on agarose gel electrophoresis and circular dichroism confirmed the molecules' integrity and purity. The gyroxin intravenous administration in mice proved its neurotoxicity (barrel rotation). In vivo studies employing intravital microscopy proved that gyroxin induces vasodilation with the participation of protease activated receptors (PARs), nitric oxide and Na+K+ATPase. The leukocytes' adherence and rolling counting indicated that gyroxin has no pro inflammatory activity. Gyroxin induced platelet aggregation, which was blocked by inhibitors of PAR1 and PAR4 receptors (SCH 79797 and tcY-NH 2 , respectively). Finally, it was proved that the gyroxin temporarily alter the permeability of the blood brain barrier (BBB). Our study has shown that both the protease-activated receptors and nitric oxide are mediators involved in the biological activities of gyroxin. (author)

  12. A Bipolar Spindle of Antiparallel ParM Filaments Drives Bacterial Plasmid Segregation

    DEFF Research Database (Denmark)

    Gayathri, P; Fujii, T; Møller-Jensen, Jakob

    2012-01-01

    the spindle between ParRC complexes on sister plasmids. Using a combination of structural work and total internal reflection fluorescence microscopy, we show that ParRC bound and could accelerate growth at only one end of polar ParM filaments, mechanistically resembling eukaryotic formins. The architecture...... of ParM filaments enabled two ParRC-bound filaments to associate in an antiparallel orientation, forming a bipolar spindle. The spindle elongated as a bundle of at least two antiparallel filaments, thereby pushing two plasmid clusters toward the poles....

  13. First (18)F-labeled ligand for PET imaging of uPAR

    DEFF Research Database (Denmark)

    Persson, Morten; Liu, Hongguang; Madsen, Jacob

    2013-01-01

    Urokinase-type plasminogen activator receptor (uPAR) is overexpressed in human prostate cancer and uPAR has been found to be associated with metastatic disease and poor prognosis. AE105 is a small linear peptide with high binding affinity to uPAR. We synthesized an N-terminal NOTA......-conjugated version (NOTA-AE105) for development of the first (18)F-labeled uPAR positron-emission-tomography PET ligand using the Al(18)F radiolabeling method. In this study, the potential of (18)F-AlF-NOTA-AE105 to specifically target uPAR-positive prostate tumors was investigated....

  14. Intact and cleaved uPAR forms: diagnostic and prognostic value in cancer

    DEFF Research Database (Denmark)

    Rasch, M.G.; Lund, I.K.; Hoyer-Hansen, G.

    2008-01-01

    identified in tissue and body fluids. It is well-established, that the total amount of all uPAR forms is a strong prognostic marker in different types of cancer. Using immunoassays, measuring the individual uPAR forms, has revealed that the cleaved uPAR forms are even stronger prognostic markers and have...... diagnostic utility. This review will focus on the mechanism of uPAR cleavage and the functional consequences, as well as the clinical applicability of cleaved uPAR forms Udgivelsesdato: 2008...

  15. Mean and extreme radio properties of quasars and the origin of radio emission

    Energy Technology Data Exchange (ETDEWEB)

    Kratzer, Rachael M.; Richards, Gordon T. [Department of Physics, Drexel University, Philadelphia, PA (United States)

    2015-02-01

    We investigate the evolution of both the radio-loud fraction (RLF) and (using stacking analysis) the mean radio loudness of quasars. We consider how these properties evolve as a function of redshift and luminosity, black hole (BH) mass and accretion rate, and parameters related to the dominance of a wind in the broad emission-line region. We match the FIRST source catalog to samples of luminous quasars (both spectroscopic and photometric), primarily from the Sloan Digital Sky Survey. After accounting for catastrophic errors in BH mass estimates at high redshift, we find that both the RLF and the mean radio luminosity increase for increasing BH mass and decreasing accretion rate. Similarly, both the RLF and mean radio loudness increase for quasars that are argued to have weaker radiation line driven wind components of the broad emission-line region. In agreement with past work, we find that the RLF increases with increasing optical/UV luminosity and decreasing redshift, while the mean radio loudness evolves in the exact opposite manner. This difference in behavior between the mean radio loudness and the RLF in L−z may indicate selection effects that bias our understanding of the evolution of the RLF; deeper surveys in the optical and radio are needed to resolve this discrepancy. Finally, we argue that radio-loud (RL) and radio-quiet (RQ) quasars may be parallel sequences, but where only RQ quasars at one extreme of the distribution are likely to become RL, possibly through slight differences in spin and/or merger history.

  16. THE RADIO PROPERTIES OF RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES ON PARSEC SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Minfeng; Chen, Yongjun; Shen, Zhiqiang [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Komossa, S.; Zensus, J. A. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Yuan, Weimin [Key Lab for Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Wajima, Kiyoaki [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong, Daejeon 305-348 (Korea, Republic of); Zhou, Hongyan, E-mail: gumf@shao.ac.cn [Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136 (China)

    2015-11-15

    We present the detection of the compact radio structures of 14 radio-loud narrow-line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array (VLBA) observations at 5 GHz performed in 2013. While 50% of the sources of our sample show a compact core only, the remaining 50% exhibit a core-jet structure. The measured brightness temperatures of the cores range from 10{sup 8.4} to 10{sup 11.4} K with a median value of 10{sup 10.1} K, indicating that the radio emission is from non-thermal jets, and that, likely, most sources are not strongly beamed, thus implying a low jet speed in these radio-loud NLS1 galaxies. In combination with archival data taken at multiple frequencies, we find that seven sources show flat or even inverted radio spectra, while steep spectra are revealed in the remaining seven objects. Although all of these sources are very radio-loud with R > 100, their jet properties are diverse in terms of their milliarcsecond (mas) scale (parsec scale) morphology and their overall radio spectral shape. The evidence for slow jet speeds (i.e., less relativistic jets), in combination with the low kinetic/radio power, may offer an explanation for the compact VLBA radio structure in most sources. The mildly relativistic jets in these high accretion rate systems are consistent with a scenario where jets are accelerated from the hot corona above the disk by the magnetic field and the radiation force of the accretion disk. Alternatively, a low jet bulk velocity can be explained by low spin in the Blandford–Znajek mechanism.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  18. The radio spectral energy distribution of infrared-faint radio sources

    Science.gov (United States)

    Herzog, A.; Norris, R. P.; Middelberg, E.; Seymour, N.; Spitler, L. R.; Emonts, B. H. C.; Franzen, T. M. O.; Hunstead, R.; Intema, H. T.; Marvil, J.; Parker, Q. A.; Sirothia, S. K.; Hurley-Walker, N.; Bell, M.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Callingham, J. R.; Deshpande, A. A.; Dwarakanath, K. S.; For, B.-Q.; Greenhill, L. J.; Hancock, P.; Hazelton, B. J.; Hindson, L.; Johnston-Hollitt, M.; Kapińska, A. D.; Kaplan, D. L.; Lenc, E.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Morgan, J.; Oberoi, D.; Offringa, A.; Ord, S. M.; Prabu, T.; Procopio, P.; Udaya Shankar, N.; Srivani, K. S.; Staveley-Smith, L.; Subrahmanyan, R.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.; Wu, C.; Zheng, Q.; Bannister, K. W.; Chippendale, A. P.; Harvey-Smith, L.; Heywood, I.; Indermuehle, B.; Popping, A.; Sault, R. J.; Whiting, M. T.

    2016-10-01

    Context. Infrared-faint radio sources (IFRS) are a class of radio-loud (RL) active galactic nuclei (AGN) at high redshifts (z ≥ 1.7) that are characterised by their relative infrared faintness, resulting in enormous radio-to-infrared flux density ratios of up to several thousand. Aims: Because of their optical and infrared faintness, it is very challenging to study IFRS at these wavelengths. However, IFRS are relatively bright in the radio regime with 1.4 GHz flux densities of a few to a few tens of mJy. Therefore, the radio regime is the most promising wavelength regime in which to constrain their nature. We aim to test the hypothesis that IFRS are young AGN, particularly GHz peaked-spectrum (GPS) and compact steep-spectrum (CSS) sources that have a low frequency turnover. Methods: We use the rich radio data set available for the Australia Telescope Large Area Survey fields, covering the frequency range between 150 MHz and 34 GHz with up to 19 wavebands from different telescopes, and build radio spectral energy distributions (SEDs) for 34 IFRS. We then study the radio properties of this class of object with respect to turnover, spectral index, and behaviour towards higher frequencies. We also present the highest-frequency radio observations of an IFRS, observed with the Plateau de Bure Interferometer at 105 GHz, and model the multi-wavelength and radio-far-infrared SED of this source. Results: We find IFRS usually follow single power laws down to observed frequencies of around 150 MHz. Mostly, the radio SEDs are steep (α IFRS show statistically significantly steeper radio SEDs than the broader RL AGN population. Our analysis reveals that the fractions of GPS and CSS sources in the population of IFRS are consistent with the fractions in the broader RL AGN population. We find that at least % of IFRS contain young AGN, although the fraction might be significantly higher as suggested by the steep SEDs and the compact morphology of IFRS. The detailed multi

  19. Affirmation of triggered Jovian radio emissions and their attribution to corotating radio lasers

    Science.gov (United States)

    Calvert, W.

    1985-01-01

    It is argued that the original statistical evidence for the existence of triggered radio emissions and corotating radio lasers on Jupiter remains valid notwithstanding the critique of Desch and Kaiser (1985). The Voyager radio spectrograms used to identify the triggered emissions are analyzed and the results are discussed. It is shown that the critique by Desch and Kaiser is unjustified because it is not based on the original event criteria, i.e., the correlation between the occurrence of Jovian auroral kilometric radiation and fast-drift type III solar bursts in the same frequency.

  20. Dynamic Filament Formation by a Divergent Bacterial Actin-Like ParM Protein.

    Directory of Open Access Journals (Sweden)

    Anthony J Brzoska

    Full Text Available Actin-like proteins (Alps are a diverse family of proteins whose genes are abundant in the chromosomes and mobile genetic elements of many bacteria. The low-copy-number staphylococcal multiresistance plasmid pSK41 encodes ParM, an Alp involved in efficient plasmid partitioning. pSK41 ParM has previously been shown to form filaments in vitro that are structurally dissimilar to those formed by other bacterial Alps. The mechanistic implications of these differences are not known. In order to gain insights into the properties and behavior of the pSK41 ParM Alp in vivo, we reconstituted the parMRC system in the ectopic rod-shaped host, E. coli, which is larger and more genetically amenable than the native host, Staphylococcus aureus. Fluorescence microscopy showed a functional fusion protein, ParM-YFP, formed straight filaments in vivo when expressed in isolation. Strikingly, however, in the presence of ParR and parC, ParM-YFP adopted a dramatically different structure, instead forming axial curved filaments. Time-lapse imaging and selective photobleaching experiments revealed that, in the presence of all components of the parMRC system, ParM-YFP filaments were dynamic in nature. Finally, molecular dissection of the parMRC operon revealed that all components of the system are essential for the generation of dynamic filaments.