Temporal evolution of age data under transient pumping conditions

International audienceWhile most age data derived from tracers have been analyzed in steady-state flow conditions, we determine their temporal evolution when starting a pumping. Our study is based on a model made up of a shallowly dipping aquifer overlain by a less permeable aquitard characteristic of the crystalline aquifer of Plœmeur (Brittany, France). Under a pseudo transient flow assumption (instantaneous shift between two steady-state flow fields), we solve the transport equation with a backward particle-tracking method and determine the temporal evolution of the concentrations at the pumping well of CFC-11, CFC-12, CFC-113 and SF6. Apparent ages evolve because of the modifications of the flow pattern and because of the non-linear evolution of the tracer atmospheric concentrations. To identify the respective role of these two causes, we propose two successive analyses. We first convolute residence time distributions initially arising at different times at the same sampling time. We secondly convolute one residence time distribution at various sampling times. We show that flow pattern modifications control the apparent ages evolution in the first pumping year when the residence time distribution is modified from a piston-like distribution to a much broader distribution. In the first pumping year, the apparent age evolution contains transient information that can be used to better constrain hydrogeological systems and slightly compensate for the small number of tracers. Later, the residence time distribution hardly evolves and apparent ages only evolve because of the tracer atmospheric concentrations. In this phase, apparent age time-series do not reflect any evolution in the flow pattern

The INRIA-LIM-VocR and AXES submissions to Trecvid 2014 Multimedia Event Detection

-This paper describes our participation to the 2014 edition of the TrecVid Multimedia Event Detection task. Our system is based on a collection of local visual and audio descriptors, which are aggregated to global descriptors, one for each type of low-level descriptor, using Fisher vectors. Besides these features, we use two features based on convolutional networks: one for the visual channel, and one for the audio channel. Additional high-level featuresare extracted using ASR and OCR features. Finally, we used mid-level attribute features based on object and action detectors trained on external datasets. Our two submissions (INRIA-LIM-VocR and AXES) are identical interms of all the components, except for the ASR system that is used. We present an overview of the features andthe classification techniques, and experimentally evaluate our system on TrecVid MED 2011 data

Investigations on the vulnerability of advanced CMOS technologies to MGy dose environments

This paper investigates the TID sensitivity of silicon-based technologies at several MGy irradiation doses to evaluate their potential for high TID-hardened circuits. Such circuits will be used in several specific applications suc as safety systems of current or future nuclear power plants considering various radiation environments including normal and accidental operating conditions, high energy physics instruments, fusion experiments or deep space missions. Various device designs implemented in well established bulk silicon and Partially Depleted SOI technologies are studied here up to 3 MGy. Furthermore, new insights are given on the vulnerability of more advanced technologies including planar Fully Depleted SOI and multiple-gate SOI transistors at such high dose. Potential of tested technologies are compared and discussed for stand-alone integrated circuits

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High Total Ionizing Dose and Temperature Effects on Micro- and Nano-Electronic Devices

This paper investigates the vulnerability of several micro- and nano-electronic technologies to a mixed harsh environment involving high total ionizing dose at MGy levels and high temperature. Such operating conditions emerge today for several applications like new security systems in existing or future nuclear power plants, fusion experiments, or deep space missions. In this work, the competing effects of ionizing radiations and temperature are characterized in elementary devices made of MOS transistors from several technologies. First, devices are irradiated using a radiation laboratory X-ray source up to MGy dose levels at room temperature. Devices are either grounded or biased during irradiation to simulate two major circuit cases: a circuit which waits for a wake up signal, representing most of the lifetime of an integrated circuit operating in a harsh environment, and a nominal circuit function. Devices are then annealed at several temperatures to discuss the post-irradiation behavior and to determine whether an elevated temperature is an issue or not for circuit function in mixed harsh environments

An Overview of Buried Oxides on Silicon: New Processes and Radiation Effects

This paper presents a review of the main properties of the two types of buried oxides that currently dominate the Silicon-On-Insulator (SOI) technologies: SIMOX (Separation by IMplantation of OXygen) and BESOI (Bond and Etch-Back SOI) materials. After examining the main advantages of SOI structure for radiation-hardened electronics, we present different advanced technological processes of such buried oxides and review their physical characteristics as well as their charge trapping properties under ionizing radiations.Cet article présente une revue des principales propriétés des deux types d'oxyde enterrés qui dominent actuellement les technologies Silicium-sur-Isolant (Silicon-On-Insulator, SOI) de la microélectronique : le matériau SIMOX (Separation by IMplantation of OXygen) et le matériau BESOI (Bond and Etch-Back SOI). Après avoir rappelé les principaux avantages d'une architecture Silicium-sur-Isolant pour une électronique dédiée aux environnements radiatifs, nous présentons les différents procédés de fabrication actuels de ces couches d'oxyde enterrées et passons en revue leurs caractéristiques physiques ainsi que leurs propriétés de piégeage de charge sous rayonnement ionisant

Etude de la transmission du signal sous irradiation transitoire dans les fibres optiques

Ce mémoire présente une étude sur la réponse des fibres optiques à une irradiation transitoire (impulsion X, ~1 MeV, doses 10-8 (10 puissance 8) rad s(exposant)-1). Des mesures complémentaires sous irradiation gamma continue ont aussi été accomplies(~1,2 MeV, doses 108 rad s-1). Additional measurements under steady-state gamma-ray have also been performed (~1,2 MeV,doses <=20 krad, dose rates ~0,5 rad s-1). Our study falls within the more general framework of the integration of optical fibers into the Laser Megajoule facility. The first chapter describes this framework together with the radiation induced defects in pure ordoped silica. The second chapter is focus on the experimental set-up used to measure the induced attenuation. We also give a sum up of the obtained measurements with pure-silica-core fibers and with fibers doped with germanium and/or phosphorus. The third chapter is dedicated to the analysis of the induced losses. The experimental spectra of radiation-induced attenuation have been decomposed with absorption bands related to absorbing defects generated. We have used an original method of decomposition based on the use of absorption bands previously identified in literature. Some physical mechanisms of defect generation and defect transformation have been suggestedST ETIENNE-Bib. électronique (422189901) / SudocSudocFranceF

Radiation Effects in Thin-Film Ferroelectric PZT for Non-Volatile Memory Applications in Microelectronics

This paper deals with ionising radiation effects (X or $\gamma$-rays) in ferroelectric materials for electronic non-volatile memories. After the recall of main observations, mechanisms are analysed and proposed to take into account the effects in PZT-based capacitors. Fatigue of the hysteresis cycle are studied and linked to irradiation effects. As for irradiation, fatigue shows a damping of hysteresis curves. We show that a connection exists between fatigue and irradiation. A mechanism is proposed based on domain wall motion and pinning.Cet article traite des effets des radiations ionisantes (rayons X ou $\gamma$) dans les matériaux ferroélectriques destinés aux composants électroniques utilisant des couches minces polarisables (mémoires non-volatiles). Après avoir rappelé les types d'observations, on propose certaîns mécanismes pour décrire ces effets dans les caparités à base de PZT. Les effets de fatigue du cycle d'hystérésis sont étudiés et interprétés en les couplant aux effets d'une irradiation. Comme l'irradiation, la fatigue par cyclage montre un aplatissement des courbes d'hystérésis. Dans cet exposé, on montre qu'il existe un parallèle entre les effets des irradiations et de la fatigue. Un mécanisme est proposé basé sur le mouvement des parois de domaine et son empêchement progressif par épinglage des parois

Electrical properties of Ta2O5 films obtained by plasma enhanced chemical vapor deposition using TaF5 source

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Contribution of age data to the characterization of complex aquifers

International audienceEnvironmental tracers have been extensively used to get characteristic groundwater velocities. When sampled in discharge zones, we show that they can also be efficiently used to get more integrative information on aquifer structure, which is especially valuable in complex geological settings like hard-rock contexts. Used in combination with generally available hydraulic data, they give useful prediction of the residence time distribution. Our analysis is illustrated on the produced crystalline aquifer of Plœmeur (Brittany, France) formed at a dipping contact zone between granites and micaschists. Although constrained on the same hydraulic head and CFC-12 data sampled at the produced well, full steady-state hydrogeological models and simpler exponential-like models yield predictions of the renewal rate and of the cumulative residence time that may differ by a factor 2. Differences come predominantly from the km-scale geological structures and topographical features that cannot be resolved by statistical models and are nonetheless essential within the characteristic dating range of the CFCs (0-70 years). Our analysis highlights the interest of combining hydraulic and age information for the prediction of residence time distributions within full hydrogeological models, and the capacity of identifying global hydrogeological structures from point-like dat