7,040 research outputs found

    Maturation sexuelle et fonctionnement ovarien de Rhammatocerus schistocercoides (Rehn, 1906) (Orthoptères, Acrididae, Gomphocerinae), acridien ravageur de l´état du Mato Grosso (Brésil).

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    The 8 bits 100 MS/s Pipeline ADC for the INNOTEP Project – TWEPP-09

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    This paper describes the Analog to Digital Converter developed for the front end electronic of the IN2P3 INNOTEP project by the “pole microelectronique Rhone-Auvergne”. (Collaboration between LPC Clermont-Ferrand and IPNL Lyon). This ADC is a 4 stages 2.5 bits per stage pipe line with open loops track and holds and amplifiers. It runs at 100MSamples/s and has 8 bits resolution. The stages used two lines, the gain line and the comparison line, with most operators running in current. The main idea of this current line is to make a first step toward an all in current structure. Currently, this ADC is designed with a 0,35μm SiGe technology

    Electron beam profile imaging in the presence of coherent optical radiation effects

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    High-brightness electron beams with low energy spread at existing and future x-ray free-electron lasers are affected by various collective beam self-interactions and microbunching instabilities. The corresponding coherent optical radiation effects, e.g., coherent optical transition radiation, render electron beam profile imaging impossible and become a serious issue for all kinds of electron beam diagnostics using imaging screens. Furthermore, coherent optical radiation effects can also be related to intrinsically ultrashort electron bunches or the existence of ultrashort spikes inside the electron bunches. In this paper, we discuss methods to suppress coherent optical radiation effects both by electron beam profile imaging in dispersive beamlines and by using scintillation imaging screens in combination with separation techniques. The suppression of coherent optical emission in dispersive beamlines is shown by analytical calculations, numerical simulations, and measurements. Transverse and longitudinal electron beam profile measurements in the presence of coherent optical radiation effects in non-dispersive beamlines are demonstrated by applying a temporal separation technique.Comment: 12 pages, 11 figures, submitted to Phys. Rev. ST Accel. Beam

    Madagascar - Mission de formulation d'un Programme de Lutte Antiacridienne à court, moyen et long termes.

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    Relata os resultados da Missão à Madagascar, visando a formulação de um Projeto de Luta Antiacrediana em conjunto com a FAO.bitstream/item/105449/1/1279.pd

    Transport Phenomena and Structuring in Shear Flow of Suspensions near Solid Walls

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    In this paper we apply the lattice-Boltzmann method and an extension to particle suspensions as introduced by Ladd et al. to study transport phenomena and structuring effects of particles suspended in a fluid near sheared solid walls. We find that a particle free region arises near walls, which has a width depending on the shear rate and the particle concentration. The wall causes the formation of parallel particle layers at low concentrations, where the number of particles per layer decreases with increasing distance to the wall.Comment: 14 pages, 14 figure

    A Charge-Sensitive Amplifier Associated with APD or PMT for Positron Emission Tomography Scanners

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    to be presented at the 32nd International Convention MIPRO (Microeectronics, Electronics, and Electronic Technology (MEET)), Opatija, Croatia, May 25-29 2009We present a Charge-Sensitive Amplifier (CSA) to be coupled with a 511-KeV 2-photon detector for positron emission tomography scanners. The circuit has been designed to be associated with an Avalanche Photodiode (APD) or Photo-Multiplier Tube (PMT) with large capacitance. It is a two-stage structure. The input stage consists of a foldedcascode fully-differential part and a common-mode feedback (CMFB) circuit. The output stage employs complementary source followers. The amplifier has been designed in a 0.35μm BiCMOS process with optimization of noise and speed performances to meet specific constraints. Its main characteristics evaluated by post-layout simulations are: 70-dB DC gain, 4.6-GHz GBW, 20-ns peaking time for pulsed stimulus, 3900-electron equivalent input noise charge (ENC), 135-mW power consumption at 3.5 V supply

    In situ electrical characterization of YxTiy getter thin films during thermal activation

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    International audienceTransition metals alloys are the most studied getter films for wafer-level vacuum packaging of MEMS. In this work we investigated yttrium and Y x Ti y alloys films that could possibly overcome the limitations of usual getter materials, i.e. reversible sorption of hydrogen and low sorption ability for hydrocarbon gases. As a preliminary step towards this objective, properties of (co-)evaporated yttrium and Y x Ti y films were analyzed by SEM, EDS, XPS and in-situ sheet resistance measurements before, after and/or during annealing in vacuum. As deposited and annealed films have a small grain size and a columnar structure. It is shown that yttrium and Y x Ti y films can be activated after 1 hour of annealing in vacuum at 250 °C if the Y-content is larger than ~9 %. These results are promising for the use of Y-based films as low temperature getters for vacuum packaging

    Pulse Shape Analysis with scintillating bolometers

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    Among the detectors used for rare event searches, such as neutrinoless Double Beta Decay (0ν\nuDBD) and Dark Matter experiments, bolometers are very promising because of their favorable properties (excellent energy resolution, high detector efficiency, a wide choice of different materials used as absorber, ...). However, up to now, the actual interesting possibility to identify the interacting particle, and thus to greatly reduce the background, can be fulfilled only with a double read-out (i.e. the simultaneous and independent read out of heat and scintillation light or heat and ionization). This double read-out could greatly complicate the assembly of a huge, multi-detector array, such as CUORE and EURECA. The possibility to recognize the interacting particle through the shape of the thermal pulse is then clearly a very interesting opportunity. While detailed analyses of the signal time development in purely thermal detectors have not produced so far interesting results, similar analyses on macro-bolometers (\sim10-500 g) built with scintillating crystals showed that it is possible to distinguish between an electron or γ\gamma-ray and an α\alpha particle interaction (i.e. the main source of background for 0ν\nuDBD experiments based on the bolometric technique). Results on pulse shape analysis of a CaMoO4_4 crystal operated as bolometer is reported as an example. An explanation of this behavior, based on the energy partition in the heat and scintillation channels, is also presented.Comment: Presented at the 14th International Workshop on Low Temperature Detectors, proceedings to be published in the Journal of Low Temperature Physic

    Contribution of HEP electronics techniques to the medical imaging field

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    présenté par P.-E. Vert, proceedings sous forme de CD Imagerie Médical
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