437 Works

Mechanical resonators with high dissipation dilution in precision and quantum measurements

Sergey Fedorov
Position measurements of mechanical oscillators underpin experiments spanning from applied nanoscale sensing to endeavors aiming to resolve open fundamental problems of modern physics. Sufficiently precise position measurements are also used for engineering quantum states. Because of the coupling to the thermal environment, mechanical oscillators undergo Brownian motion, which sets the lowest measurement error when an oscillator is used as a probe and puts an upper bound on the decoherence time of mechanical quantum states. The...

Bayesian modeling of brain function and behavior

Maya Anna Jastrzebowska
The application of Bayesian modeling techniques is increasingly common in neuroscience due to the coherent and principled way in which the paradigm deals with uncertainty. The Bayesian framework is particularly valuable in the context of complex, ill-posed generative problems, in which case the incorporation of prior knowledge is optimal and practical. If one wants to take full advantage of joint imaging and behavioral data, the need for comprehensive generative models is evident. Here, I exploited...

Fat navigators based retrospective motion correction strategies for brain magnetic resonance imaging

Frédéric Gretsch
Magnetic resonance resonance (MRI) is a widely used modality to obtain in vivo tissue information. Clinical applications are near countless, and almost all body parts can be examined using an MR scanner. As the method is non invasive, does not use ionizing radiation and provides excellent soft tissue contrast, it also appears as an excellent tool for neuroscience research. The major drawback of MRI remains the relatively long acquisition times, of the order of several...

Electron Beam Induced Copper Deposition from Carboxylate Precursors and the Study of Underlying Growth Mechanisms

Luisa Berger
The fabrication of defined and high-quality metal nanostructures is an ongoing topic of research. Direct-write deposition of copper nanostructures is of great value for many fields of research and industrial applications. Focused electron beam induced deposition (FEBID) is an additive fabrication technique with extremely high resolution and versatility. Physisorbed, gaseous precursor molecules are locally dissociated by a finely focused electron beam resulting in volatile fragments which desorb and non-volatile fragments forming the deposit. When applying...

Unraveling neural and behavioral mechanisms of cognitive self-attenuation and alienation

Giedre Stripeikyte
The present thesis aimed at investigating behavioral and neural underpinnings of the mechanisms related to the different aspects of self-monitoring. The first aim was to study functional connectivity alterations related to the mechanisms accounting for the alienation in psychotic patients and those at high-risk to develop it. The second aim was to extend the fundamental knowledge of whether higher-level cognitive processes beyond sensorimotor involvement are subject to attenuation and whether it is affected in psychotic...

Multiphase flows in Microfluidic Reactors

Pooria Hadikhani

Activation of small molecules promoted by multimetallic complexes supported by redox active ligands

Davide Toniolo
The activation of small molecule is a topic of high current interest. A variety of homogeneous end heterogeneous catalysts have been studied to be able to promote chemical transformation of industrial relevance under mild condition and therefore decrease the costs. Often the most performant catalysts are composed by rare and precious metals such as Pd, Pt, Rh, Ir, making the catalyst expensive and not suitable for large scale reactions. Lots of effort is put in...

The shaping effects of innovation and technology: from micro business model evolution to macro environment sustainability

Qinli Lu
Innovation is a prerequisite guarantee for the development of a country in this new era. It is an important driver not just for corporate growth but also for national social and economic transformation. Considering the strategic supporting role of innovation in the modern economic system, this thesis approaches the shaping effects of innovation and technology mainly from two important micro and macro perspectives, business model evolution and national sustainable development. The first essay takes business...

Microfluidic iMITOMI platform to study the architecture of low-affinity transcription factor binding site clusters

Ivan Istomin
Gene regulatory networks (GRNs) determine cellular behaviour, and ultimately the functioning of single- and multicellular organisms. Transcription factors regulate gene expression by binding to DNA or via remodelling chromatin. Recent advances in biotechnological methods have made it possible to precisely characterise the binding of transcription factors to single consensus binding sites. Advanced sequencing methods allow the efficient discovery of de novo binding consensus sequences, and thus provide insight into the evolution of GRNs. However, clusters...

On Vacuous and Non-Vacuous Generalization Bounds for Deep Neural Networks.

Konstantinos Pitas
Deep neural networks have been empirically successful in a variety of tasks, however their theoretical understanding is still poor. In particular, modern deep neural networks have many more parameters than training data. Thus, in principle they should overfit the training samples and exhibit poor generalization to the complete data distribution. Counter intuitively however, they manage to achieve both high training accuracy and high testing accuracy. One can prove generalization using a validation set, however this...

Numerical investigations of 3D CFTs using conformal bootstrap methods

Marten Jan Reehorst
Conformal field theories (CFTs) play a very significant role in modern physics, appearing in such diverse fields as particle physics, condensed matter and statistical physics and in quantum gravity both as the string worldsheet theory and through the AdS/CFT correspondence. In recent years major breakthroughs have been made in solving these CFTs through a method called numerical conformal bootstrap. This method uses consistency conditions on the CFT data in order to find and constrain conformal...

MATHICSE Technical Report : Finite element heterogeneous multiscale method for nonlinear monotone parabolic homogenization problems

Assyr Abdulle & Martin Ernst Huber
We propose a multiscale method based on a finite element heterogeneous multiscale method (in space) and the implicit Euler integrator (in time) to solve nonlinear monotone parabolic problems with multiple scales due to spatial heterogeneities varying rapidly at a microscopic scale. The multiscale method approximates the solution at the scale of interest at computational cost independent of the small scale by performing numerical upscaling (coupling of macro and micro finite element methods). Optimal a priori...

Carbon Nanomaterials from Oligoyne Surfactants

Enzo Bomal
Carbonaceous nanocoatings such as diamond-like amorphous carbon or graphene layers exhibit remarkable properties in multiple fields, ranging from corrosion protection to electronics and lubrication. However, they are typically deposited from the vapor phase at high temperatures (700-900C) restricting easy processing. In our laboratory, we recently developed the solution-based formation of carbon-rich films using reactive oligoyne amphiphiles that can undergo carbonization under mild conditions at room temperature. In this way, atomically dense, crosslinked carbon nanosheets were...

Protection Coordination in Marine DC Power Distribution Networks

Seongil Kim
The increasing penetration of renewable energy sources, energy storage systems (ESSs), and DC loads has opened the door to DC technology to pave its way into future grids. The shift has been more obvious in the marine domain supported by track records of installed onboard DC solutions since 2013. This new type of power system comes with technical challenges in protection coordination due to no natural current zero-crossing and low fault ride-through capability of power...

Electron Cloud and Synchrotron Radiation characterization of technical surfaces with the Large Hadron Collider Vacuum Pilot Sector

Elena Buratin
This PhD thesis presents the experimental study on electron cloud (EC) and synchrotron radiation (SR) phenomena affecting the LHC storage ring performance. These phenomena are one of the major issues of the LHC storage ring, generating beam instabilities, pressure rise and heat loads on the beam pipes. This experimental study is carried out with an innovative system installed in a room temperature and field free section of the Large Hadron Collider (LHC), the Vacuum Pilot...

Synthesis, reactivity, and environmental relevance of uranyl(V) complexes.

Radmila Faizova
Knowledge of fundamental chemical properties of all environmentally relevant uranium species is essential to understand environmental uranium mobility and develop novel remediation strate-gies. A myriad of uranium(VI) and uranium(IV) compounds has been studied for decades but the uranyl(V) analog was traditionally thought of as a highly unstable species of limited environmen-tal importance. This understanding has changed in the last decade with studies demonstrating uranyl(V) to be a persistent species in Fe rich environments and an...

Increasing Functionality of III-V Nanowires on Silicon Substrates

Wonjong Kim
Progress in nanotechnology, including fabrication and characterization tools, opened up the unprecedented low dimensional materials era, where we can manipulate and structure matter on a size scale that we could not reach before. Due to many interesting properties of nano-sized materials different from their bulk counterparts, we now have opportunities both in combining new material properties with existing technologies and in establishing new technologies. In this context, combining mature silicon technology with III-V compound semiconductors...

Point, Plane, Set, Match! Winning the Echo Grand SLAM

Miranda Krekovic
Some of the most important and challenging problems in science are inverse problems. They allow us to understand phenomena that cannot be measured directly. Inverse problems might not always have a unique or stable solution, or might not have any solution at all; in these cases, they are called ill-posed. An example of an inverse problem in room acoustics is simultaneous localization and mapping (SLAM) from sound. It is the central theme of this thesis,...

Sparse and Parametric Modeling with Applications to Acoustics and Audio

Helena Peic Tukuljac
Recent advances in signal processing, machine learning and deep learning with sparse intrinsic structure of data have paved the path for solving inverse problems in acoustics and audio. The main task of this thesis was to bridge the gap between the powerful mathematical tools and challenging problems in acoustics and audio. This thesis consists out of two main parts. The first part of the thesis focuses on the questions related to acoustic simulations that comply...

MATHICSE Technical Report: Numerical homogenization method for parabolic advection-diffusion multiscale problems with large compressible flows

Assyr Abdulle & Martin Huber
We introduce a numerical homogenization method based on a discontinuous Galerkin finite element heterogeneous multiscale method (DG-HMM) to efficiently approximate the effective solution of parabolic advection-diffusion problems with rapidly varying coefficients, large Péclet number and compressible flows. To estimate the missing data of an effective model, numerical upscaling is performed which accurately captures the effects of microscopic solenoidal or gradient flow at a macroscopic scale such as enhancement or depletion of the effective diffusion. For...

Parallel and Scalable Bioinformatics

Stuart Anthony Byma
The field of genomics is likely to become the largest producer of data as a consequence of the large-scale application of next-generation sequencing technology for biological research and personalized medical treatments. The raw sequence data produced by these methods is limited in usefulness and requires computational analysis to unlock its potential. Bioinformatics is a field that combines biology, genomics, and computer science to build algorithms and software to analyze biological data. Some of the current...

Carbon fluxes and productivity regimes in Alpine streams

Marta Boix Canadell
High-altitude catchments have a major role in the transport of organic matter to streams due to the storage of dissolved organic carbon (DOC) in soils and glacier ice and the subsequent mobilization during the melting processes. Yet, stream function goes beyond the conveying downstream of the terrestrial and glacier derived DOC since they are also highly active in the mineralization, retention and production of organic matter. Stream ecosystem metabolism integrates the processes that regulate the...

Initial experimental tests, setups, discussions and challenges for OSB connections

Aryan Rezaei Rad, Julien Gamerro, Geoffroy Ghion & Yves Weinand
In order to fulfill all design requirements for a project, some experimental tests as well as numerical investigations has been conducted. The main intention of the current report is to give an insight into the experimental tests which we expected to get the maximum slip modulus by considering a combination of different and possible nailing distance, nailing positions, and tenon-like wood-wood connections. In the following sections, a detailed description of test setups as well as...

On the assessment of aspheric refractive microlenses

Jeremy Béguelin
Refractive microlenses and microlens arrays are key components for many applications such as optical data communication, laser and medical devices, or cameras. In particular, refractive micro-optics enables the miniaturization of high-tech systems but also offers novel optical functionalities. The success of this technology lies in the wafer-level fabrication technique, using the method of photoresist reflow with a subsequent pattern transfer into the substrate by reactive ion etching. Indeed, it allows the manufacturing in parallel of...

High-throughput microfluidic platforms for characterizing and engineering cell-free gene regulatory circuits

Zoe Newell Swank
Cell-free systems have emerged as a versatile platform for constructing complex biological systems from the bottom-up. In particular, they enable the rapid engineering and characterization of gene regulatory networks, a critical cellular subsystem that allows a cell to sense and respond to a myriad of signals with a computational-like logic. Building synthetic gene circuits provides the means to both program new functionalities and augment our understanding of natural networks. Genetic circuits are composed of elements...

Registration Year

  • 2020
    437

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