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Post-Doctoral : Modelling of Cohesive Granular Flows

Secteur d'activité : Recherche et enseignement

Employeur : Sorbonne université

Localisation : Paris

Description :

Granular matter is important in a wide variety of engineering and industrial applications, as well as for the mitigation of catastrophic geophysical flows. Although our understanding of this class of material has steadily improved in the last twenty years, many open questions remain. Thebehaviour and rheology of cohesive granular systems forms one of them. Cohesion between rigid macroscopic grains occurs commonly in the presence of humidity (capillary bonds), when the size of the grains becomes critically small (van der Walls forces, for instance in most powders), or may be intrinsic to the system studied (as is snow and ice avalanches, or for material subject to lectrostatic/magnetic forces). Cohesive contacts in a granular system induce the emergence of intermediate length scales controlling the co-existence of flowing and rigid zones. The way the “flowability” of the system is affected, and the translation in terms of a modified rheological model for cohesive granular flows, is unclear in most flow configurations.
The aim of the project is to investigate the flowability/rheology of cohesive flows in two challenging test configurations. A Bagnold flow over a bump, and the collapse of a step, will be both considered.
Discrete (Contact Dynamics) and continuum (Basilisk) numerical simulations tools will be applied to explore the flow characteristics and test rheological models.
The position will take place in the granular team within the FCIH group in Institut D’Alembert to work with Pierre-Yves Lagrée, Lydie Staron, Stéphanie Deboeuf and Stéphane Popinet, in the framework of the ANR Coprint on Cohesive Powders (PI Maxime Nicolas). As such, it will benefit from interactions with the granular team in IUSTI (Marseille) and with Saint Gobain-CREE. Interactions with the University of Twente will be funded by an existing Van Gogh grant.

Profil :

The ideal candidate will demonstrate experience/knowledge in fluid mechanics, particulate systems and numerical modelling. Application should be sent to P-Y. Lagrée (pierre-yves.lagree@upmc.fr)
and L. Staron (lydie.staron@upmc.fr), including a detailed CV. Closure date for application is 31st December 2018.

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Post-Doctoral : Tectonics / Structural Geology

Secteur d'activité :

Employeur : IPGP

Localisation : Paris

Description :

The Institut de Physique du Globe de Paris has an opening for a post-doctoral position to carry out research in tectonics and structural geology. The project (PI: Martine Simoes) is funded by the Agence Nationale de la Recherche (ANR) to assess active deformation and seismic hazards in slowly deforming orogens, by quantifying deformation over various timescales, from long-term geological deformation down in time to short-term processes at the scale of the seismic cycle. The Western Kunlun mountain range (China) will be considered as a case example.
The post-doctoral fellow will take an active role in the quantification of deformation across this mountain range and its foreland basin (the Tarim Basin) over the long-term, i.e. over several Myr to 10s Myr. The objectives of this work will be to assess active structures, their contribution to cumulative shortening, the overall shortening rate to be accommodated across the mountain range and the eventual evolution over time of these parameters. To complete this task, the postdoctoral fellow will take advantage of the extensive and unique compilation of geological observations, maps and seismic profiles that our group has recently compiled at the regional scale. Depending on the obtaining of permits, he/she will also participate to data acquisition in the field. Based on these data, he/she will build balanced cross-sections and will make an efficient use of the exceptional sedimentary archives to define the timing of faults from growth strata, their cumulative shortening and will from there incrementally restore the evolution of deformation. The acquired knowledge on the long-term kinematics of deformation will also be used to quantify a first-order thermal structure of the mountain range and its foreland basin.

The candidate will benefit from various interactions and collaborations within the Tectonics group of the Institut de Physique du Globe de Paris and elsewhere to additionally propose and
develop his/her own line of research. The post-doctoral fellow will present his/her scientific results in international meetings, and write scientific papers to be published in peer-reviewed international journals.

Profil :

Duration / Salary
This Post-Doctoral position is proposed for a duration of 24 months, to be started as early as September 2019 and at latest by January 2020. Net salary will depend on previous experience
of the candidate, and will average ~25 k€/year.

Application
The candidates should have completed a PhD degree in tectonics or structural geology, with experience in building and restoring geological cross-sections. The applicants are expected to send their curriculum and a brief summary of their past research experience and scientific results to Laurie Barrier (barrier@ipgp.fr) and Martine Simoes (simoes@ipgp.fr).
The names and contact information of two (or more) referees will also be provided. Applications are open and will be considered upon reception as long as the position is vacant.
For further information on the position and/or on the project:
Laurie Barrier: barrier@ipgp.fr - (+33)(0)1 83 95 76 08
Martine Simoes : simoes@ipgp.fr - (+33)(0)1 83 95 76 26

Post Doctoral (and Ph.D) : opportunities in computational geophysics

Secteur d'activité : Recherche et enseignant

Employeur : King Fahd University of Petroleum and Minerals

Description :

I am creating a new research group in computational geophysics and invite applications for Post Doctoral and Ph.D. positions. Applicants with a strong background in computational geophysics or computational physics are invited to apply. The successful applicants will have a degree in computational geophysics, applied mathematics or related field, with strengths in computational methods including macroscopic approaches such as finite-differences, finite elements, spectral elements, pseudo-spectral, finite volume and discontinuous Galerkin methods, or microscopic approaches such as Discrete Elements and Lattice Boltzmann Methods. Research topics include computational seismology, computational geodynamics, computational fluid dynamics, multiphase fluid flow, and Full Wavefield Inversion.

Research goals will be to both develop and apply such computational methods to address fundamental research in geophysics and computational methods, particularly having long term relevance to understanding the physics of the earth and
the physics and dynamics of crustal processes and hydrocarbon and geothermal reservoirs systems. Topics may include but are not limited to seismic wave propagation, Full Wavefield Inversion, inversion including machine learning, granular dynamics, hydraulic fracturing and multiphase flow.

Profil :

Post Doctoral applicants must have a proven track record in at least one of the above fields, strong programming skills particularly in python, and MPI experience or ability to learn parallel programming paradigms and implement their
research on large scale parallel computers.

Ph.D. applicants must have a degree formation that allows them to excel in the above fields.

Applicants should send a letter of up to two pages introducing themselves and stating their research interests, and including a CV of no more than 6 pages to Professor Peter Mora at wolop2008@gmail.com. The deadline for applications is December 3, 2018, but applications should be sent as soon as possible. Starting dates are negotiable, but early in 2019 is preferred. Positions include free on campus accommodation and a full stipend (Ph.D. students) or salary (post docs) that is tax free. Further information can be obtained by emailing to Professor Peter Mora.

Professor Peter Mora
College of Petroleum Engineering and Geosciences
King Fahd University of Petroleum and Minerals
http://cpg.kfupm.edu.sa/