Title: Optimization in a verified compiler

Bugs have been found in mainstream compilers such as gcc and LLVM. For some safety-critical applications (e.g. fly-by-wire aircraft), industrial users may therefore prefer disabling optimizations so that the compiled code easily matches the source code. This results in poor performance. The CompCert compiler (compcert.org) features a formal proof of correctness: executions of the compiled code are shown to match those of the source code by a theorem whose proof was verified by a software proof assistant.

We have added to this compiler a new backend and new optimizations, which also have to be formally proved correct.

Joint work with Sylvain Boulmé, Cyril Six, Léo Gourdin

Title: A Behaviour-based Approach to Quantitative Validation of Cyber-Physical Systems

Abstract: In this talk we describe a behaviour-based approach to quantitative property validation of Cyber-Physical Systems (CPS). The heterogeneity and complexity of industrial CPS make a behaviour-based approach very desirable since It is widely recognized that it is hard or impossible to derive sound mathematical models for such systems. Quantitative validation means providing, instead of a Boolean answer about property satisfaction, quality measures, such as confidence interval, robustness bound, coverage of the set of tested behaviours over the set of all possible behaviours, etc.

We first discuss the problem of encoding and measuring CPS signal spaces with respect to some approximation quality measures. In particular, we consider signal spaces subject to temporal constraints, namely they must satisfy given timing assumptions or properties. For a set of (usually uncountably many) signals representing CPS behaviours of interest, an approximation quality measure reflects how well a finite set of signals sampled from the original set can replace the original set in terms of property validation. We discuss a number of measures for sets of temporal behaviours: uniformity, epsilon-entropy and discrepancy measures. We then describe methods for generating CPS signals with good approximation quality, by combining sampling (as in Monte Carlo and quasi-Monte Carlo methods) and optimisation. The approach is  finally illustrated on CPS benchmarks in particular in automative control.

Title: A Separation of Concerns Approach for the Verified Modelling of Railway Signalling Rules

Auteurs : Yves Ledru, Akram Idani, Rahma Ben Ayed, Abderrahim Ait Wakrime, Philippe Bon

Abstract: This paper proposes a modelling approach for railway signalling rules.

It adopts a separation of concerns approach similar to the one used in information systems security. It first models the effect of operations, and then specifies permissions involving the agent performing the action and the conditions that must be satisfied before performing this action.
These models are expressed in SecureUML diagrams enhanced with B assertions. It then takes advantage of the B4MSecure tool to translate these diagrams into B machines. It finally relies on the ProB tool to verify the model using model-checking and animation. Model-checking assesses the reachability of desired states, and verifies the absence of accidents. The approach proceeds by introducing human errors, checking their consequences, and deploying counter-measures.

Title: Separation of Concerns in Medical Device Safety Assurance

Title: Combining physics-based simulation, medical image registration, and computer vision to localize pulmonary nodules during video-assisted thoracoscopic surgery

Video-assisted thoracoscopic surgery (VATS) is a minimally invasive surgical technique for the diagnosis and treatment of early-stage lung cancer. During VATS, large lung deformation occurs as a result of a change of patient position and a pneumothorax (lung deflation), which hinders the intraoperative localization of pulmonary nodules. We have thus proposed a twofold, multidisciplinary approach to localize and track a lung nodule during surgery.

The first part of the project consists in finding the intra-operative nodule position. Our method relies on physics-based simulation of deformable organs, which has become a powerful tool for surgical planning, guidance, and training. The lung is first modeled as a biphasic, poroelastic medium with allowance for air evacuation, which enables the Finite Element simulation of the lung deformation and deflation. Elastic registration of pre- and intra-operative medical images provides partial boundary conditions and loads for the model. Simulations are then run iteratively to maximize the similarity between the deformed model and actual images. A retrospective study on five clinical cases showed residual errors in the 5 to 10mm range, which corresponds to a compensation of 75% of the localization error, on average.

The second part of the project is augmented-reality, for real-time superimposition of the nodule position on the endoscopic video. Computer vision and monocular SLAM methods will be presented to track the camera pose and lung movement within the thoracic cavity.

Title: Combining Literate Programming and Code Generation to Improve the Reproducibility and Sustainability of Scientific Computing Software

Title: Software composition at scale: 50 shades of scalability

tbd

Title:  The Evolution of the Epsilon Model Management Platform

Monday 2:00pm – 5:00pm Meeting Recording:
https://mcmaster.zoom.us/rec/share/-ordKhC1Xge6H_z56tSfZgNCSEmDo4ENEpfk5AUQdF7_GDIkmxiWx_KdkFF45u9x.oDe8AapuSoa4n0wI
Access Passcode: we3b1ok?

Tuesday 2:00pm – 5:00pm Meeting Recording:
https://mcmaster.zoom.us/rec/share/EszrQZFo6ywngDRhMq7yddpPhD2Cq4EmfAt0l4uRLhLYwURGEPBLB-SxH4uiVxvk.j1CvTB4VP7DqcxsP
Access Passcode: cE39&1s8

Wednesday 9:00am – 12:00pm Meeting Recording:
https://mcmaster.zoom.us/rec/share/4IuvOiK-730nz9dabzXUCmtCGL1jBxP05ICrf63I8ERNoSxQqcdBbdro0wbmNM5l.9Y0ijiuImayYWwX5
Access Passcode: T8$vqKZ+

Title: Airsea: numerical methods for ocean, atmosphere and their interactions

Abstract:
This presentation will present a tour of current Airsea’s activities. They are targeted to applications covering oceanic and atmospheric modeling and related extreme events using a hierarchy of models of increasing complexity. Its scientific objectives are divided into four major points. The first objective focuses on developing advanced mathematical methods for both the ocean and atmosphere, and the coupling of these two components. The second objective is to investigate the derivation and use of model reduction to face problems associated with the numerical cost of our applications. The third objective is directed toward the management of uncertainty in numerical simulations. The last objective deals with efficient numerical algorithms for new computing platforms.

Title: Clustering Three-Way Data

Title: “Simulation-based Bayesian inference for high dimensional inverse problems”

Abstract: We investigate the use of learning approaches to handle Bayesian inverse problems in a computationally efficient way when the observations to be inverted present a moderately high number of dimensions and are in large number. We propose a tractable inverse regression approach which has the advantage to produce full probability distributions as approximations of the target posterior distributions. These distributions have several interesting features. They provide confidence indices on the predictions and can be combined with importance sampling or approximate Bayesian computations schemes for a better exploration of inverse problems when multiple equivalent solutions exist. They generalise easily to variants that can handle non Gaussian data, dependent or missing observations. The relevance of the proposed approach is illustrated  on synthetic examples and on two real data applications, in the context of planetary remote sensing and neuroimaging. The approach shows interesting capabilities both in terms of computational efficiency and multimodal inference.

Title: WAVETRISK-OCEAN: an adaptive dynamical core for ocean modelling

Title: Axisymmetric vortex rings at high Reynolds numbers

Vortex rings are three-dimensional flows characterized by a vorticity distribution that is concentrated in a solid torus. A natural way to construct such flows is to consider axisymmetric solutions without swirl of the 3D Euler or Navier-Stokes equations, assuming that the initial data are suitably localized. We focus on the particular case where the initial vorticity is a single vortex filament, the circulation of which may be arbitrarily large compared to viscosity. We show that the axisymmetric Navier-Stokes equations are globally well-posed in this context, and we perform an asymptotic expansion of the solution in the vanishing viscosity limit. In particular, we obtain a rigorous justification of the binormal flow approximation for the advection speed of a viscous vortex ring with Gaussian profile.

This talks is based on joint work with Vladimir Sverak (Minneapolis).

Title: Shape optimization of mechanical systems

Abstract: This presentation is devoted to the introduction of a recent method for shape and topology optimization which features an explicit (meshed) discretization of the optimized shape — so that precise mechanical calculations can be performed with the finite element method — and still allows for arbitrarily large evolutions of the shape (including topological changes). After recalling a few notions regarding shape optimization, and notably the main ingredients involved in the device of numerical algorithms, we present with a little more details the level set method for shape optimization and spend a few words on meshing aspects, as the building blocks of our method. The main aspects of this framework are illustrated with several numerical examples, in two and three space dimensions. This presentation summarizes a body of work conducted with, in particular, G. Allaire, F. Feppon and P. Frey.

Title: Fracture of brittle heterogeneous materials

Title: Quick presentation of the Laboratoire Jean Kuntzman

Title: Machine learning regression for optimal stopping problems

Abstract: Optimal stopping problems arise in many applications such as gambling games or American options. Optimal stopping problems are usually solved through their dynamic programming principle formulation, in which the main difficulty comes from the conditional expectation involved in the computation of the continuation value. These conditional expectations are classically computed by regression techniques on a finite dimensional vector space, however they scale badly with the dimension of the problem. In this talk, we discuss two alternative regression approaches coming from machine learning: neural networks and random forests. We present theoretical results ensuring the convergence of such approximations and illustrate their efficiency on examples coming from American option pricing.

Title: Isometric embedding and quasi-local mass

Title: CMC foliations of quasi-Fuchsian manifolds

Abstract: Quasi-Fuchsian are an important class of hyperbolic three-manifolds. In this talk I will present several results, obtained in a joint work with Diptaishik Choudhury and Filippo Mazzoli, on their foliations by constant mean curvature (CMC) surfaces. A conjecture due to Thurston asserts that every almost-Fuchsian manifold has a global CMC foliation: in the first part of the talk I will present a partial result in this direction, namely that every quasi-Fuchsian manifold in a neighbourhood of the Fuchsian locus is foliated by CMC surfaces. In the second part of the talk I will then explain how these CMC foliations induce Hamiltonian flows on the cotangent bundle of the Teichmüller space, and give some elements of the proof.

Title: Quick presentation of McMaster Dept of Mathematics and Statistics and A mathematical model for green investment and monetary policy

Please find all Digital Humanities session recordings at:

https://scds.github.io/dh-roundtable/

Title: Navigating the meanders of digital politics in the name of science: the example of online petitions to the UK’s parliament 

Abstract: Over the last decade, e-petition systems have been implemented in a variety of countries by political institutions ranging from the Scottish Parliament to the White House. Whereas the real-life impact of such initiatives has been actively debated among scholars, with some portraying them as a prime example of ‘slacktivism’, such systems are still widely popular with the public. Studying their mechanics thus remains of crucial importance even though their novelty has now waned.   

Between 2011 and 2019, over 110,000 e-petitions were submitted online to the UK’s Parliament which made available under an open license their data and metadata and provided an API for their collection, thus paving the way for prolific scientific use. Yet gathering and making sense of such voluminous, heterogeneous and complex data presents significant technical, methodological and epistemological challenges which this presentation will address so as to initiate a discussion on such issues with colleagues at McMaster in the humanities and social sciences and more broadly, with those involved in multidisciplinary digital projects.  

Bio: Géraldine Castel is an associate professor (maître de conférences) in British studies at UGA. She is co-director of the Politics, Discourse and Innovation team within the Languages and Cultures’ lab at UGA and a UGA referent for digital methods in teaching. Her main research area is British politics, and more particularly the online communication strategies of parties and candidates, as well as tools for online mobilisation. She sits on the committee of Humanistica, the international association of French speaking digital humanities and is particularly interested in data mining and data visualisation. 

Title: GIS Applications in Greek Archaeology: Measuring the Land at Metaponto  

Abstract: The Metaponto Archaeological Project is a research initiative affiliated with McMaster’s Department of Classics that is focused on reconstructing ancient settlement patterns in the territory of the Greek colony of Metaponto, located in Southern Italy. Research includes both archaeological surface survey and excavation in order to trace both the growth of the new foundation and interactions between the Indigenous population and Greek settlers. Research methods employed in the fieldwork include using GIS tools to map sites and surveyed areas, as well as remote sensing to manage excavation data. These digital tools contribute to a diachronic map of settlement patterns and land use that helps to reconstruct the growth and decline of an ancient city.  

Bio: Spencer Pope is an Associate Professor in the Department of Classics at McMaster University and co-director of the Metaponto Archaeological Project. His research is focused on reconstructing dynamics of interactions between Greeks and the Indigenous populations of Italy and Sicily. 

Title: Critical Methodological Approaches for Digital Humanities Scholarship: A Reflection 

Abstract: Working at the nexus of critical communication studies, digital scholarship, and the digital humanities across the various facets of my work, I champion approaches to digital humanities scholarship that are methodologically attuned to material, contextual, and historical specificities of digital cultures writ large. In my presentation, I elaborate and reflect on how these concepts shape my current research agenda at the intersection of critical cybersecurity studies and data justice. My presentation stems from my observations and experiences. However, I endeavour to move beyond the personal and seek opportunities to collectively foster critical methodological approaches that refute normative assumptions about what it means to do digital humanities scholarship and who gets to belong within these spaces.”

Bio: Andrea Zeffiro is an assistant professor in the Department of Communication Studies and academic director for the Lewis & Ruth Sherman Centre for Digital Scholarship.  

Title: Detecting, characterising and monitoring the emergence of proto-communities in online news analysis 

Abstract: This presentation deals with online info-communication practices in relation to current events. The growing importance of social media in the public information space has considerably increased the possibilities for opinion manipulation, particularly through a set of broadcasting accounts to which robots or humans are assigned. Often naturalised, these coordinated devices give the appearance of communities and act without the control of platforms and collective regulations. Identifying these devices is an additional reason to study collective dynamics in digital social media and integrate them into the study of info-communication practices.  

Our work consisted of producing a digital toolkit that integrated the functionalities of data collection and supervised enrichment and algorithmic exploitation of these data in order to detect, characterise and follow the emergence of proto-communities. By this we mean candidate collective structures whose specific characterisation suggests that they are actual communities or native communities. Our presentation will be based on a “sustainable development and energy transition” use case for which we are undertaking long-term monitoring work. 

Bio: Jean-Marc Francony is an associate professor (maître de conférences) in information and communication sciences at UGA. He has an Habilitation to direct research (HDR) and is in charge of the Publishing course of UGA’s master in professional studies in publishing. He is particularly interested in Web Data Mining, Social Uses and Practices of the Web and Digital Traceology. He is in charge of the Digital Data Fabrik and involved in research projects such as CLIMAX for the collection of web data, COPERNIC meant to capture, segment and structure massive flows of publications or yet Media Swell, an experimental platform to analyze the practices and social uses of online communication devices. 

Title: “Humanitarian” Communication on social network sites: Construction of a (post) colonial imaginary narrative from a gender perspective.  

Abstract: Twenty photographs taken and put up on the web (MSF net) between 2000-2020 were analysed thanks to the database building capabilities of the Access software. I will show the criteria selected for the constitution of the discriminatory categories among the photographs, then study how international humanitarian aid represents aid-receiver women on social media. The presentation will also analyse how international NGOs use photographs of women receiving humanitarian aid on social media to communicate information about the work they do and provide a digital resource where, based on various quantitative and qualitative categories, theoretical concepts that define the type of representation that NGOs make of women receiving aid can be determined. Twenty more photographs were then added to identify new constructions on different social media websites with an activist scope. These photographs, analyzed from quantitative and qualitative categories, allowed us to analyze an alternative discourse to the hegemony of NGOs. 

Bio:  Cristina Garcia Martinez is a fourth-year PhD student in Hispanic Studies at the Universite Grenoble Alpes (France) and in Gender Studies at the Rovira I Virgili University (Spain). Her thesis title is “Humanitarian aid, gender, and digital communication: women’s image on international NGO. The case of Choco, Colombia (2000-2020).” Her research is focused on gender studies and the colonial matter in humanitarian aid. She has carried out a research sojourn at the Technological University of Choco (Colombia) and has published a good number of scientific papers. She is an assistant professor at the University of Grenoble Alpes in the Foreign Languages Department and Language, Literature, and Foreign and Regional Civilizations Department since 2020.  

Title: Micro-blogging about melanoma on Instagram: info-communicational competences and the professionalised show-casing of cancer.  

Abstract: Stemming from research that focuses on the rise in the public sphere of testimonials by people with ill-health and micro-blogging practices on social media platforms, this presentation will develop an analysis of the accounts of three people with melanoma. Using both a socio and semio-discursive approach, this work will show how some social media users combine a capacity to build a story upon their experience of cancer, to develop a network that takes part in publicizing their story, and they then have it integrated into media underpinned by market logics, thus substantiating the universal dimension of its content. 

Bio: Chloé Salles is an associate professor (maître de conférences) in information and communication sciences at UGA. She is Head of studies at the Grenoble School of Journalism and International scientific cooperation officer for her lab. Her work focuses on professional identity and practices of journalists in the context of online journalism. 

Title: Data management and digital humanities: research and education. The case of Education Technology 

Abstract: On the theme of research data management, the presentation shows the alignment between the objectives of a research project and the pedagogical objectives of a Master’s degree. The Master’s degree at UGA in publishing studies includes a course dealing with issues of information engineering, architecture and mediation. This course trains students to process, enrich and make available data sets. In order to practice on a real case scenario, they participated in a digital humanities’ research project aimed at shedding light on the positioning of Ed Tech (Education technology) players in France in the spring of 2020, i.e the first Covid-19 lockdown period.  

The project’s aims are to contribute to new methodological approaches in information and communication sciences, integrating the collection and automatic processing of data, underline the evolutions visible in school education where new actors offer different pedagogical models, and identify the changes that these data processing techniques generate in the transmission of knowledge in documentation. This project is part of the work carried out by UGA’s Digital Data Fabrik, a team studying the challenges introduced by Big Data in the humanities and social sciences.  

Bio: Aude Inaudi is an associate professor (maître de conférences) in information and communication sciences at UGA. She is in charge of the Documentation course of UGA’s master in Teaching, Training and Education, and of the Documentation and Libraries’ course in UGA’s master in professional studies in publishing. Her work offers a critical approach to the use of digital technology in education, documentation and libraries as well as a focus on communication, organisational and political issues of technical and human mediation. She is PI of the the LivMed project whose goal is to change the role of books from documentary tools to mediation devices. 

Title:  Using Digital Tools to Sharpen Critical Analysis and Communication Skills in the History Classroom 

Abstract: With support from colleagues at the Sherman Centre for Digital Scholarship, I have been working with various DH tools (OMEKA, JS Timeline, and Hypothes.is) in my history classes.  In this short presentation, I focus on the “why” of using these tools and lay out the learning objectives I have in mind when I ask students to learn the tech on the way to sharper, more focussed communication that blends the written word with images. I will show examples of student work completed this year in my Contemporary US History (JS Timeline) and Archival Methods (OMEKA) classes. 

Bio: Karen Balcom is an Associate Professor of History and Gender & Social Justice at McMaster University, where she is also the Academic Director (Teaching and Learning) at the Office of Community Engagement.  She is a former Paul MacPherson Teaching Fellow. She does research on the history of transnational adoption and on community-engaged pedagogy, and is always experimenting with Digital Humanities tools in the classroom.   

Title: ¯\_(ツ)_/¯: Zooming Pedagogies and Queering Academia 

Abstract: Academia has been moving toward digital landscapes in an attempt to replicate in-person university experiences online. Yet the COVID-19 pandemic has made for swift shifts to the virtual that accelerate expectations that Zoom can sustain transferable academic working and learning conditions, including the performance of academic norms along with an adherence to the methodological and professional rigidity of the university. We, however, consider how Zoom offers affordances to queer academic pedagogies, especially in the digital humanities, through what we call a “networked togetherness.” Drawing on autoethnographic analyses of our use of Zoom in DH context, and particularly the chat function, as a vehicle for networked togetherness, we turn to subcultural humour, memes, emojis, and links as methods to queerly subvert both the expected uses of Zoom for academics and performing academia itself. We put ourselves in conversation with digital platform and networked studies as well as queer theory and the digital humanities, to speak to the possibilities of fostering a collective culture that acknowledges interdependence and precarity in academia through the Zoom screen amid physical and emotional distance. 

Bio: Alexis-Carlota Cochrane is a PhD Student in the Department of Communication Studies and Media Arts at McMaster University. Her research intersects platforms, algorithms, censorship, digital culture and data justice. Follow her Twitter for updates: @Alexis_Carlota.  

Bio: Theresa N. Kenney is a PhD Candidate and Teaching Fellow in the Department of English and Cultural Studies at McMaster University. Her research explores asexual, aromantic, and platonic relationalities in queer Asian North American cultural production. Her research can be found in Feminist Formations and decomp journal and she is a featured guest expert on asexuality in the documentary series The Big Sex Talk on CBC Gem. You can find her online @ToPoliticise. 

1. Karen Balcom (Associate Professor of History, McMaster University) and Myron Groover (Archives and Rare Books Librarian, McMaster University) on Omeka S  

2. Geraldine Castel (Associate Professor, British Studies, Universite Grenoble Alpes) on Tableau 

3. Devon Mordell (Educational Developer, Paul R. MacPherson Institute, McMaster) on Voyant Tools

Title: Microstructure Studies of Additive Manufacturing

Additive manufacturing is an opportunity for the energy field to produce sophisticated geometries. However, there are still several roadblocks to its use to make a wide variety of parts. One needs to demonstrate that parts produced with conventional processing routes can be substituted by parts fabricated by additive manufacturing. The objective of this work is to shed light on the microstructure-mechanical property relationships of two types of materials : 316L austenitic stainless steel produced by laser powder bed fusion (L-PBF)and superalloys. In 316L, one specific powder leads to a finer grain structure that goes along with texture randomization. The underlying mechanism responsible for grain refinement and texture randomization will be discussed and can be considered as an alloy design strategy in the framework of additive manufacturing. In superalloys, induced segregations and precipitations are studied at nanometer scale to explain hot cracking observed in some alloys.

Title: AM Research at McMaster: Processing and Properties

Title: High-throughput investigations of phase transformations in multi-component alloys : combinatorial experiments and machine learning 

The assessment of compositional effects on phase transformations and their kinetics is a labor-intensive and time-consuming endeavor when using discrete-composition samples, in terms of both the preparation and the experiments themselves. Such a task can be greatly accelerated using a combinatorial methodology based on the combination of compositionally graded samples with in situ time- and space-resolved synchrotron diffraction. This methodology will be illustrated through its recent successful application to the austenite-to-ferrite transformation. The unprecedented amount of data that was collected provides some long awaited insight into the mechanism of this transformation when it happens with negligible partitioning of substitutional elements and is well-suited to machine learning modeling approaches.

Title: Accelerated Material Discovery Platforms

Title:Magnetic materials for energy conversion

Increasing energy consumption and greenhouse gas emission has triggered extensive research on energy conversion materials. Our investigations are focused on intermetallic materials for magnetic refrigeration on one hand and permanent magnets applications on the other hand.

Magnetocaloric effect and magnetic refrigeration

Replacing conventional vapor-based refrigeration (15% of the total energy generated worldwide) with  magnetic refrigeration (solid state) is the goal. Magnetic refrigeration is based on the magnetocaloric effect that is a change in temperature and/or entropy of a material upon application of a magnetic field.

Our goal  is to design and discover new MC materials with properties, notably changes in isothermal entropy and adiabatic temperature, superior to current systems. This requires a mastering of the interplay between structural and magnetic properties. Examples of our current investigations will be presented on the following intermetallic compounds.

1- magnetostructural properties of model Laves compounds (AFe2 systems) and extended to new intermetallic phases to be synthesized in the frame of an exploratory research approach seeking for high performance materials for magnetocaloric applications or hard magnetic phases. Magnetically and structurally tunable AFe2 systems are of particular interest as potential magnetocaloric materials.

2- La(Fe,Si)13 –type compounds . The Curie temperatures of La0.7Ce0.3Fe13-x–yMnxSiy compounds that are hydrogenated to saturation can be raised to near room temperature and adjusted to the desired working temperature by regulating Mn content based on the linear relationship between TC and Mn content.  Neutron diffraction reveals the preferential occupancy of Mn atoms. The giant magnetocaloric effect, linearly adjustable TC, and excellent age stability make the La0.7Ce0.3Fe11.55-yMnySi1.45 hydrides be one of the ideal candidates for room temperature magnetic refrigerants.

Hard ferromagnetic materials

Hard ferromagnetic materials with high remanent magnetization (permanent magnets) are of great industrial and household importance, since those are key components of electric generator systems. Efforts are made to discover and study yet different magnetic materials in various related R-M-B (R = rare-earth metals and M = transitions metals) systems. Our investigations aim at performing both targeted and exploratory research in the R-M-B systems for a search of novel ferromagnetic materials with applications as highly performant and accessible permanent magnets. Results will be presented on the R-M-B/C systems in which addition of light and non-magnetic B atoms introduces additional structural complexity which, in turn, can yield formation of compounds with different magnetic properties. One example is the Rn+1Co3n+5B2n system (CaCu5-type structure, P6/mmm) for which different n values yield distinct phases: RCo4B for n = 1; R3Co11B4 for n = 2; R2Co7B3 for n = 3 and RCo3B2 for n = ∞.

Title: Characterization of Advanced Functional and Energy Materials

Title: Dynamic fracture, very high loading rates, tests under vacuum

In the present work the tensile strength of ceramics is investigated based on shockless plate-impact spalling test. The Target made of a buffer plate as front face and ceramic plate as backing is impacted by a wavy-machined flyer plate allowing the wave front to be smoothed to obtain strain-rate ranging from 9,000 to 30,000 s-1. Based on these experimental data, the strain-rate sensitivity of ceramics is deduced.

Title: Biological Tissues and Biomaterials

Bone diseases require increasingly complex diagnosis for efficient treatment. There is growing evidence that multiscale structural characteristics of the mineralized tissue need to be considered for such diagnosis and to better understand the fundamental pathological processes. We will show how the potential offered by the specific expertise in bone nanoscale analysis using the electron microscopy infrastructure of the CCEM at McMaster, combined to this acquired using synchrotron radiation and optical microscopy at UGA provide a unique framework for such purposes.

Highlights presentation of biomedical research and collaboration at University of Tokyo.

Highlights presentation of materials science research and collaboration at University of Tokyo.

Highlights presentation of nuclear research and collaboration at University of Tokyo.

Highlights presentation of research and collaboration at Universities of Toronto and Tokyo.

Title: Electrohydrodynamic enhancement of heat transfer in dielectric fluids  

Electrohydrodynamic is the multiphysic coupling between electric fields and fluid flows. When imposing an electric field within a media using external electrodes, one can actively enhance processes by modifying the flows involved. Grenoble and McMaster are places where this physics has been foreseen for decades as a means of heat transfer enhancement. After giving a brief overview of the state of the art, recent developments done at Grenoble on the EHD enhancement of two-phase heat transport devices and on single phase EHD convection will be presented.

Title: Sustainability in High Temperature Process Metallurgy

Title: Presentation of the experimental platform Coriolis

I will present the Coriolis platform at LEGI, Grenoble, measuring 13 m in diameter, is the largest rotating platform in the world dedicated to fluid mechanics. Its main activity is the experimental modeling of geophysical flows, taking into account the rotation of the Earth, the density stratification and the topography. The large dimensions allow to approach the inertial regimes that characterize the ocean/atmospheric dynamics, with a weak influence of viscosity and centrifugal force. The realized laboratory experiments allow to test the ocean/atmospehric dynamics models and to develop their physical parametrizations, crucial for reliable prediction of ocean and climate models.

Examples of realized projects will be presented too.

Title: Computational Materials Engineering

Title: Interaction between cracking and microstructure: examples and comments on fracture models

We illustrate the interaction between fracture and microstructure by presenting a study devoted to the estimation of durability of plasma spray coatings. The influence of the processing, environment and load level. A multi-scale approach is adopted in which the inter-splat and intra-splat crack growth is described with a rate- temperature and humidity dependent cohesive zone model that mechanically represents the reaction-rupture mechanism underlying stress and environmentally assisted sub-critical failure. It is found that the relaxation of the initial thermal stresses generates a significant initial damage at the inter-splat scale by the nucleation of inter-splat cracks and a minor initial damage at the intra-splat scale. The results show that the rate of inter-splat cracks increases with the relative humidity and especially with the temperature at which the relaxation occurs. The effect of the initial damage generated by the thermal aging on the resistance of the polycrystal of plasma sprayed zirconia against intra-splat slow crack growth under static fatigue loading is investigated. The results show that the initial damage at the intra-splat scale does not affect its resistance against intra-splat slow crack growth. However, the initial damage at the inter-splat scale leads to an increase in the slow cracking rate for a loading level KI and a reduction in the threshold load K0 below which no slow crack growth occurs as the individual splat is embedded in a damaged equivalent continuum representing the overall splat structure. The aim of this work is to provide a reliable predictions and insight in long lasting applications of plasma sprayed ceramic materials.

Reference: B El Zoghbi, R Estevez, Surface and Coatings Technology, 438, 128379.

Tuesday 2:00pm – 5:00pm Meeting Recording:
https://mcmaster.zoom.us/rec/share/W5sIP3mTkbFqkxJ95hlIPbMRLH04JM27i5QQVUXYNZc89XfRbV9zTD4GhaCDgG-6.69u5flYlcQeV1KlU
Access Passcode: M9DCWsU=
presentation begins at 9:10 mark

Wednesday 9:00am – 12:00pm Meeting Recording:
https://mcmaster.zoom.us/rec/share/GAxYPM7GV0m5IR6SNEHOkjAZtrL9D8dLWb4llLz0P_8eTthYL_FHSyHqQyOyzWMr.03eeDLFwuF5hZonK
Access Passcode: ?tXCd4VQ
presentation begins at 50:53 mark

Title: Multi-sensor remote sensing, biomass mapping

Title: How can environmental communication contribute to an evolution of human-environment relationships? Focus on middle mountain territories

Title: Overview of the observations & researches in environment at the Observatory of Earth and Universe Sciences (OSUG)

The Observatory is a structure which belong to a national network (managed by the CNRS) and has for missions to locally coordinate and support the research, the observation and the teaching in all these scientific domains : astrophysics, planetology, geophysics, geochemistry, geology, glaciology, hydrology, climatology, environment, ecology, sociology for the environment (risks, ressources, adaptability to changes,…). Including some transverse axes as for the instrumentation in extrem area. I will present an overview of our work in observing the natural systems, as well as the way the scientific projects can be constructed over different units thanks to specific programs, offering a holistic approach.

Title: Republicans and climate action: obstacles, challenges, and opportunities

Title: Hydrological and biogeochemical models

Title: Hydrodynamics and reactive transfer of particles and pollutants in the critical zone, from the pore to the watershed.

The HyDRIMZ team of IGE aims to study the quality of environments subjected to anthropogenic activities and climate change in contexts where bio-geochemistry is strongly constrained by water transfer conditions. The team approaches the study of strongly coupled phenomena characteristic of the critical zone through a close collaboration between soil physicists and hydrogeologists, surface water physicists, microbiologists and biogeochemists. The fine analysis of physical and bio-geochemical processes is based on combined modelling and experimental approaches under controlled conditions (infiltration in the field, laboratory devices) aiming to characterise and prioritise eco-mechanisms (transport, reactions, sorption) at the micro (pores, particles) and meso (columns, lysimeters) scales. The study of the spatio-temporal distribution of matter flows and impact, which is at the heart of the team project, is approached using numerical tools adapted to each situation, allowing the identified processes to be taken into account (e.g. hydro-sedimentary flows, reactive transfers in the vadose zone, hydrogeological transfers, Biogeochemical processes in the river-estuary salinity gradient). Examples of some important investigation lines will be presented and more specifically on soil erosion, bacteria transfer in soil and pollutants biogeochemistry and impact in the compartments of the critical zone.

Title: Mountains in a Changing World: White wilderness spaces for well-being

Title: Multiscale molecular modelling:  Applications to chemical reactivity and transport across cell membranes

Abstract: Through a few examples, we will show interactions between theory and experience.

The first example will concern the mechanistic study of Fe-Ni complexes in aqueous solution through interaction with graphene and which can convert CO2 into CH4.1 We will present our results about the first steps of this mechanism. First, we will show how the complex interacts with the graphite surface. For this, we have used the SurfOnDock2  to generate the geometry for molecules on surfaces and find the most stables. In a second step, we will show how CO2 interacts and coordinates with the complex and we will study the possible sites of protonation.

A second example will focus on the transport of non-charged cyclopeptides across cell membranes. Promising recent experimental results (non published results) provide compounds of the same family but with very different permeability properties. Simulations will shed light on the molecular details as a function of the environment (aqueous or lipophilic) and during the permeation processes.3 We will propose a rationalisation and understanding of the structure/permeability relationships, through both the structural study of these cyclopeptides in different media (polar and hydrophobic), but also the simulation of their penetration through the lipid membrane.

A third example will present the Theoretical investigations on the [3+2] cycloaddition reaction of aziridines with ketenes catalyzed by lithium salts

Title: From Natural Products to New Synthetic Methods

Abstract: The development of flexible synthetic pathways that provide easy access to both natural products and analogues continually requires new and more effective strategies. Overs the past years, we have been studying the reactivity of ketenes in various cycloaddition reaction, recently exploring the use of ketenes in flow chemistry, and developing the synthesis of a variety of natural product, the most recent being (–)-Omuralide. We have also been investigating the synthesis of lycorine type alkaloids using tandem metathesis and new chiral amide equivalent for the controlled synthesis of a,b-chiral amines. Our recent results in these areas will be presented.

Pr Jean-François Poisson is developing novel synthetic methods for the total synthesis of natural products; he has experience in organometallic chemistry and organic synthesis in general, with a recent interest in flow chemistry to master the instability of highly reactive species. His research span from ketene cycloadditions, to the synthesis of chiral amines using chiral imidates, and the synthesis of high valency sulfur derivatives. In addition, in the organic synthesis group in Grenoble, the research activities cover a large array of organic chemistry fields, from the chemistry at the origin of life, the reactivity of nitrones in the synthesis of potent iminosugars and the synthesis of heterocycles with antibiotic properties, to catalysis with asymmetric carbene reactions and sustainable multi-catalysed cascade reactions.

Title: Synthesis and engineering of biomolecules for diagnostic and therapeutic applications

Abstract: The team’s research activity focuses on the chemistry of biomolecules (nucleic acids, sugars, peptides, proteins) in order to design macromolecular systems for diagnostic or therapeutic applications in the health field (cancer, neuropathies, bacterial and viral diseases). In addition to the use of ligation strategies, the team is experienced in physico-chemical and biochemical studies (ITC, SPR, BLI, AFM, CD, ELISA, fluorescence assays…), molecular and cellular biology. Dr. S. Chierici, assistant professor, who will introduce the team, is involved in AD research projects. She studies the interactions of synthetic ligands with amyloid fibrils, and develops synthetic tau fibril models.

Keywords: Chemical Biology, Biomolecules, Ligation strategies, Physico-chemical studies

Contact: S. Chierici, Assistant professor, Department of Molecular Chemistry

Team: Engineering and Biomolecular Interactions

https://dcm.univ-grenoble-alpes.fr/research/i2bm-team

Wednesday 2:00pm – 5:00pm Meeting Recording:

Title: An Origins Route to Astrobiology

Title: Non-Enzymatic RNA Polymerization in Warm Little Ponds and Consequences for Early Life

Title: Ammonium Ions Promote RNA Polymerization using Non-Activated Nucleotides under Hot-Cold and Hydration Dehydration Cycles

Title: An Origins Route from the RNA World to the Genetic Code … to Extreme Organisms

Title: tbd

Title: Skeleton Growth in 0 g: Spherical Sea Urchins