NCube/papyrus huggingface dataset:
Production de plasmons et degré d’ionisation pour des reculs nucléaires dans les détecteurs de matière sombre au silicium de SuperCDMS

SuperCDMS (Super Cryogenic Dark Matter Search) is an experiment for the direct detection of dark matter that uses cryogenic silicon and germanium detectors which can measure energy deposition as low as a few eV.  One of the biggest challenges in the search for dark matter is to block the various background events. One of those background source is the excitation of plasmons by Compton scattering, a phenomenon that generally deposits about ten eV and which affects mainly semiconductor detectors. In this work, we will estimate the production rate of plasmons and argue that we must understand this background in order to claim evidence of dark matter.  One of SuperCDMS's other challenges is the calibration of its detectors at very low energy. Indeed, dark matter is known to interact with the atom's nucleus, but unfortunately, there is no data at the moment about the ionization yield of nuclear recoils below 0,7 keVnr in silicon, where keVnr is the energy deposited in keV in a nuclear recoil (nr). In the second part of this work, we will show how the IMPACT experiment (Ionization yield Measurement with Phonons At Cryogenic Temperature), a sub-experiment of SuperCDMS composed of members of SuperCDMS, aims to measure the ionization yield for nuclear recoils between 0,1 and 4 keVnr in silicon. It is important for SuperCDMS to know this ionization yield to reconstruct the energy deposited in their detectors by a nuclear recoil from a dark matter particle.

Keyphrases: SuperCDMS, plasmons, dark matter, direct detection, ionization yield for nuclear recoils, liquid scintillators
Modification of microfibrillated cellulose foams by atmospheric-pressure plasmas

The treatment of different polymers issued from renewable sources has recently become of high interest in today’s scientific community. This work focused on the treatment of microfibrillated cellulosic foams, issued from wood biomass, in an atmospheric pressure dielectric barrier discharge in helium. When foams occupied all of gas gap volume, we demonstrated that the discharge ignites and propagates through the foams. The act of outgassing before plasma treatment has also been shown to be highly beneficial to the production of homogeneous glow-like discharges. Indeed, it was found that, in outgassed conditions, discharges occurring at a frequency of 60 kHz were glow-like, while those at 10 kHz were filamentary. However, significantly less damage was observed on the foams subjected to a 10 kHz discharge as opposed to those subjected to a 60 kHz discharge. In non-outgassed situations, we have also shown that the release of oxidising species originating from ambient air upon plasma ignition considerably increased injected and dissipated power in the plasma, in turn producing more damage than in outgassed conditions. This knowledge was then applied to the modification of these foams using a hexamethyldisiloxane precursor for plasma deposition to adjust their wettability to water and to oil. When foams occupied all of gas gap volume, the discharge regime was filamentary, and produced inhomogeneous coating, often very localised around damaged regions. When foams took up only a portion of gas gap volume, a homogeneous glow-like discharge was observed, inducing defibrillation of the cellulosic fibers. These conditions produced hydrophobicity on both the top and bottom surfaces of the foams, all while maintaining the foam’s characteristic oleophilicity. This supports the idea of selective adsorption of oily wastewater using a green, biodegradable, and renewable cellulosic product.

Keyphrases: Interaction plasma-cellulose, Cellulosic materials, plasma-cellulose interaction, optical, dielectric barrier discharge, optical and electrical diagnostics, plasma deposition, Hydrophobicity, Oleophilicity, Selective adsorption, Outgassing, Atmospheric pressure
Décharges Sparks dans les liquides diélectriques : caractérisation et application à la synthèse de nanoparticules

This research project is part of the international master's program in Physics (plasma option) between Université de Montréal and Université Paul Sabatier - Toulouse (France). It concerns the synthesis of nanoparticles by pulsed electrical discharges in liquids. The objective is to develop the synthesis process while improving the knowledge of the formation conditions of nanoparticles. This involves characterizing the entire experimental system and developing its metrology on the one hand, and on the other hand obtaining the evolution of plasma parameters during synthesis. Initially, at the LAPLACE lab (UMR5213), Toulouse, it was necessary to develop a pulsed electrical supply to produce discharges in liquids. Based on an existing device that, after being improved, the discharge process is characterized from the electrical point of view (current, voltage). The application of the device in the synthesis of nanoparticles was tested under different experimental conditions, considering the energy aspect (energy balance, characteristics of the discharge, etc.). The second part was conducted at Université de Montréal, where the synthesized nanoparticles are characterized using the transmission electron microscope of Polytechnique Montreal. Also, the electrical circuit equivalent to the experimental system was determined to visualize the time evolution of the plasma parameters (Temperature and Electron Density) based on the electrical characteristics.

Keyphrases: Nickel, Cobalt, Cavitation, Nanoparticles, Spark discharge, Equivalents circuits, High voltage pulsed power supply
Développement d'un outil d'identification des paires d'électron-positron provenant de bosons Z à haute impulsion basé sur l'étude de la sous-structure des gerbes électromagnétiques au LHC

When a Z boson with high transverse momentum desintegrates into an e+e- pair, the electron and the positron leave nearly superimposed tracks which makes the detection process very difficult. The identification of massive events arising from theories like the extension of the electroweak gauge group SU(2)_1 x SU(2)_2 x U(1) leading to the existence of massive W' and Z' bosons coupling directly to standard model vector bosons and fermions is more readily performed through leptonic channel. Here, a series of rectangular cuts comprising a purely jet substructure based electron positron pair arising from the decay of a Z boson identification in boosted topologies (p_T(Z)>1TeV) is presented. The selection process of the cuts is done through a topology study of candidate events in various Monte Carlo simulation samples. The reconstruction efficiency of the electron-positron pairs is maximised. Five background sources were tested against the selection criteria to study the background rejection efficiency of the methodology. Finally, it is found that the reconstruction tool developped nearly triples electron positron identification, reaching 93% efficiency in high energy Monte Carlo samples, with insignificant background noise.

Keyphrases: Particle physics, electron-positron pairs, high energy jets, high energy leptons, high transverse momentum topologies, jet substructure
Test et calibrations technologiques avec PICO-0.1 pour les futurs détecteurs de chambre à bulle de matière sombre de PICO

Amongst the dozens of experiments aiming to be the first to claim a dark matter signal, PICO is a direct dark matter detection experiment that utilizes superheated liquid detectors as a means of doing so. The latest C3F8 filled PICO-40L bubble chamber currently located in the SNOLAB underground laboratory is under testing to prepare for a 1 live-year blinded WIMP (Weakly Interacting Massive Particle) search. To ensure the stability of the detector during both the testing and the data acquisition phases, a monitoring software was coded. A reliable way to monitor all the parameters and to send alerts accordingly plays an important role in not only the success of PICO-40L, but also the development of the future larger-scale PICO-500 detector. PICO-0.1 is a test bubble chamber located at the University of Montreal that was built to calibrate for the numerous background events that can occur in this kind of technology. This test chamber was also used as a world’s first attempt to measure the coherent (Thomson) photon scattering onto a nucleus by exposing the C3F8 filled detector to a gamma source produced by the 19F proton to alpha and gamma 16O reaction using a proton beam created by the University of Montreal particle accelerator. This kind of interaction will prove to be a significant background for future sub-keV direct dark matter detection experiments.

Keyphrases: WIMP, PICO, DAQ, dark matter, bubble chamber, Thomson scattering
Évaluation de la corrélation inter-substitut pour le suivi de tumeurs pulmonaires indirect

The main objective of this thesis is to prepare the clinical implementation of the Clarity ultrasound system for indirect lung tumours tracking using a surrogate. It is currently used for motion management during prostate treatments and requires adaptation. Our hypothesis is that an internal marker would have a better correlation with the tumour’s position than an external surrogate. The sub-objectives are : 1) test different setups for the image acquisition on patients ; 2) explore the algorithms’ performance for motion detection as well as the image quality metrics on US and dynamic MRI images ; 3) evaluate the correlation between surrogates and a lung structure to determine which performs best. The ultrasound probe is fixed on the treatment couch for the acquisition on healthy volunteers using a mechanical arm. Low pressure on the patient’s skin results in a loss of signal due to the curvilinear shape of the probe. We observed a loss of contact between the probe and the volunteers’ skin due to ample movements causing a deterioration of the image quality. We tested three different motion detection algorithms on dynamic MRI images : normalized cross-correlation (NCC), root mean square error (RMS) and optical flow. The NCC algorithm is the most robust out of the three for 5/9 volunteers for the internal surrogate tracking (  < 0.050). In specific cases, the optical flow method performed better indicating an interest in developping a new algorithm for indirect lung tracking. Finally, the correlation between the surrogates and a lung structure were calculated using the MRI images. The internal surrogate inside the liver was proven more efficient for indirect lung tumour tracking for 8/9 volunteers. External markers give a greater prediction error. It has also been shown that the positioning of the external marker on the patient’s skin impacts the correlation. The abdominal marker is better than the thoracic one for all the volunteers.

Keyphrases: Clarity, Ultrasons, Ultrasound, Image-guided radiation therapy, Lung cancer, Optical flow, Correlation
The problem of exploitation in advanced capitalism : are there feasible alternatives alleviating exploitation?

Exploitation as a concept sits at the heart of the philosophy of labour and constitutes one of the most fundamental tensions within modern capitalist societies. From as early as Thomas Aquinas, to more modern philosophers like John Locke, Adam Smith, Karl Marx, and even more contemporary, John Rawls and G.A Cohen, exploitation is a topic that has been discussed at lengths in political philosophy. However, it would seem that we are still met with the question of what it means to be exploited. Asking a libertarian and a socialist what constitutes exploitation would yield an endless debate that requires a steady ground to understand what it means to be exploited. However, it is not merely enough to understand from a definitional perspective what exploitation is. As such, this project focuses on two distinct approaches to the problem of exploitation in order to arrive at feasible solutions to a problem as old as labor itself.    In first exploring what the cannon of philosophy defines exploitation as, we will be able to situate a theoretic underpinning of the problem. Once a theoretic understanding is developed and our own working definition of exploitation is put forward, the discussion will transition into an empiric exploration of exploitation and its connection to asymmetric power relations in capitalism. A case study surrounding the store closure of Wal-Mart’s Jonquière branch will highlight the asymmetry of power between employer and employee and subsequently showcase the extent of the vulnerability of workers within advanced capitalism. This coupling of theoretic exploration and empiric realisation will allow us to isolate what factors contribute to the problem of exploitation in advanced capitalism and posit feasible solutions to the problem of exploitation. In putting forward these solutions this project seeks to understand ways in which we can render capitalism a better system for workers through the gradual diminishment of exploitation achieved through the integration of socialist principles within advanced capitalism itself.

Keyphrases: Exploitation, Vulnerability, Analytic Marxism, Feasibility, Private Government, Advanced Capitalism, Marxism, Labor, Power
Boèce de Dacie : pour une perspective nouvelle concernant la double vérité dans son De aeternitate mundi

There are two questions widely discussed by the medievalists about Boethius of Dacia. The first consist in knowing what are the stakes of the censorship of which this philosopher was one of the main targets during the condemnation promulgated in Paris in 1277 by the bishop Etienne Tempier. The second ask if Boethius actually uphold, in his De aeternitate mundi, a doctrine qualified by these same historians as ‘‘double truth’’. If this expression was not coined by Etienne Tempier himself, we nevertheless find, in the prologue to the condemnation of 1277, a formulation which translates the spirit of this expression by affirming that certain teachers said that the same thing is true according to philosophy, but false according to the Catholic faith, so that we are in the presence of two contradictory truths. Despite the consensus, established among historians of the twentieth-century, that Boethius of Dacia never defended such a doctrine, we believe that this question remains topical insofar as the text itself does not seem completely clear when it states that if faith absolutely says the truth, the philosopher also says the truth, but in a manner relative to his principles. However, such a conception is not without problems in regard to the interpretation of the principles governing the epistemology of Boethius. The sole question of our research is therefore to clarify and elucidate this indictment of ‘‘double truth’’ in view of its different texts as well as the different interpretations that his model received.

Keyphrases: Science, simpliciter/secundum quid, Medieval philosophy, History of philosophy, Medieval university, Theory of knowledge, Science, Double truth, Faith, Double truth, Simpliciter/secundum quid
Démocratie expérimentale et philosophie pour enfants

Recently in Quebec, a majority of eligible voters have expressed their discontent with the current political system. Citizens say they experience disempowerment and feel a lack of real choice in the political process. In the age of rising populism, this represents a pressing concern to ensure the vitality of our democracy.   The purpose of this thesis is to engage with the issue of civic engagement and social reform from the standpoint of Philosophy for children (P4C). The research question can be formulated as such: “How can P4C contribute to an effective response towards the unsatisfied aspirations that a majority of citizens feel toward the current political system?”  In order to answer this question, we assess P4C’s democratic value and democratic potential through a radical social and political theory. We depart from more “traditional” political philosophies and direct our attention to Democratic Experimentalism developed by Roberto Unger to show how it can offer a way to envisage P4C as a means to disrupt the mere reproduction of the structure of society and bring it closer to an activity that transforms it through experimentation and collective engagement. To do so, we examine how P4C’s practices and theoretical underpinnings can be said to be compatible with such a vision of democratic life and how nonetheless its democratic potential is limited by the lack of practicality and the absence of institutional support capable of enabling experimentation and collective engagement.

Keyphrases: Roberto Unger, Matthew Lipman, Political philosophy, Experimental democracy, Philosophy for children, P4C, Philosophy of education, Pragmatism, Empowerment
L'éducation libérale entre contrainte et émancipation

This master’s thesis is about liberal theories of education, and particularly those from the analytical tradition. It studies the way these theories try to accommodate an end of emancipation, resulting from liberalism’s historical attachment to the value of individual liberty, with the authoritarian nature of schooling. Our premise states that there is a normative tension between such an end of emancipation and the methods of contemporary schooling, which consists in a planned intervention in the life of another person, aiming to model their knowledge, skills, values and understandings of the world while using coercion and discipline. The emancipatory theories of education therefore display a paradoxical will : they wish to free by coercion, to produce a gain of liberty through an initial loss of liberty. We argue that, though it is not an inescapable contradiction, the emancipatory theories of education need to address this tension, in order not to contradict their ends with their means or to rely on an inconsistent conceptualization. Our three chapters each study one the main theoretical currents in contemporary liberal philosophy of education : the « classical » liberal education, inspired by humanism, the civic education aiming to produce a respectful and democratic liberal society, and the factual education applying the liberal principal of neutrality. These educations all seem to fail to address our normative tension, mainly because of their attachment to the curricular model of education. Our main thesis states that the curricular planning of an education, prescribing its ends, contents and methods, is necessarily inconsistent with an end of emancipation, since it already constitutes a negation of the student’s autonomous will and valorizations. Hence, we conclude this thesis by outlining a non-curricular model of education, which could accommodate better an end of emancipation with the authoritarian intervention that is schooling.

Keyphrases: Curriculum, Liberalism, Emancipation, Coercion, Political philosophy
Le contextualisme de David Lewis : une réponse au défi du scepticisme

This thesis is a critical analysis of David Lewis’s contextualist solution to the skeptical problem. The skeptical problem, for Lewis, is a problem of relevant possibilities of error : given that we cannot rule out various skeptical hypotheses, it seems that knowledge is impossible. The first chapter introduces Lewis’s solution to skepticism. We’ll see that his aim is to account for the plausibility of the skeptical argument, while at the same time to protect some of our intuitions concerning knowledge. To that end, Lewis’s solution points to the specific possibilities which can be properly ignored in our knowledge attributions. Knowledge attributions are sentences like « S knows that P. » We’ll see that this explanation takes the form of a contextualist theory about relevant possibilities of error. The second chapter’s task is to locate Lewis’s theory within the literature on epistemic contextualism. Epistemic contextualism, in general, is the claim that the truth value of knowledge attributions is strongly determined by the context of the conversation. But, as this chapter should emphasize, several solutions to skepticism may share the « contextualist » label, while yielding significantly different results. The final chapter will address some important objections to Elusive Knowledge. They are related to the reasons why, according to Lewis, skepticism is a genuine problem for epistemology; on the other hand, they question the notion of elimination of error possibilities.

Keyphrases: David Lewis, Epistemology, Knowledge Attributions, Skepticism, Contextualism
Vertus et éducation morale

Moral education is a central aspect of the virtue ethics of Aristotelian tradition. Many authors are attached to the idea that a good ethical theory should inform us about how to form better moral agents. The ethicists of virtue consider that it is through an education of character that virtuous agents can be fashioned. But is such an education really possible? And if it is, what does it consist of? This thesis aims to answer these questions by exploring the horizons of the theory of virtues, horizons that now exceed the limits of philosophy. By first questioning moral naturalism in the theory of virtues, liberal naturalism is retained as the most realistic metaethical position for the future of the theory. It must take into account scientific advances, particularly in social psychology, if it wishes to achieve its educational objectives. To follow this approach, the central characteristics of the concept of virtue are identified and then tested by the situationist critique of virtues. According to the situationism, many empirical studies would show that the moral behaviors of the agents are determined by circumstantial and arbitrary factors. Therefore, a central feature of the theory, the robustness of virtues, is abandoned. This abandonment, however, does not mark the end of the theory of virtues: it is then oriented towards moral education where it remains relevant thanks to the literature on expertise and emotional intelligence. This theoretical and empirical framework makes it possible to give a solid foundation for the education of virtues. Some difficulties remain in implementing concrete curricula for the education of virtues in schools. For the future, researchers will have to take up the challenges of the school environment and the measurement of virtues.

Keyphrases: Philosophy, Moral Education, Moral Psychology, Virtues, Character Traits, Moral Naturalism, Situationist Critique, Moral Skills, Emotional Intelligence
Kierkegaard and Bloch on Hope

Hope, that residue of Pandora’s jar (πίθος), has been the subject of ambivalent philosophical judgments. Pit against being considered a form of wishful thinking that is misleading or an attitude that contributes to moral action, the verdict concerning hope’s affiliation with the illnesses and hardships that befall humanity is still pending. The question, preceding any judgment, that continues to facilitate this trial can be formulated in no simpler way: what is hope? Søren Kierkegaard and Ernst Bloch dedicated a significant portion of their authorship to help clarify such a question. Yet, what can a comparison between a Christian existentialist and a speculative materialist deliver on the topic of hope? Far from leading to the butt of a joke, a comparison of their work reveals how hope may contribute to critique, action, and ultimately, redemption. Despite the substantial differences between their objects of hope, they share certain characterizations of hope that remain philosophically salient. Against the claim that hope is misguided, they argue that hope affords us the chance to break away from the dominant ideas of the status quo. The distance affords us a new and critical experience of the issues we face, while anticipatively pointing towards what may redeem them. Distinguished from uplifting emotions or moods like joy and naïve optimism, Kierkegaard and Bloch argue that hope must be resolute about its expectation. Hope then involves our decision to anticipate and contribute to the possibility of our redemption. Lastly, hope is argued to be redemptive in itself as a struggle for possibility–for without possibility, a person seems unable to breathe.

Keyphrases: Philosophy, Hope, Redemption, Dialectics, Possibility