319 Works

Charge-carrier Dynamics in Metal Oxides and Hybrid Lead Perovskites investigated by Time-Resolved UV and X-ray Spectroscopy

Thomas Charles Henry Rossi
In modern ultrafast optoelectronic technologies based on wide band gap insulators, the non-equilibrium dynamics of photogenerated charges plays a major role. Unravelling the mechanisms of interaction between these charge carriers and their environment is crucial to support the design of more efficient devices. Especially, the absorption of photons with more energy than the optical band gap generates electrons-hole pairs (EHP) whose transport and dissociation as excitons or free charge carriers is of pivotal importance for...

Frustration and Randomness:Magnetic Studies of Organic Quantum Spin Liquids

Péter Szirmai
Spin systems with strong magnetic interactions might remain disordered avoiding conventional magnetic long-range ordering due to zero-point quantum fluctuations, and supporting a Quantum Spin Liquid (QSL) state. Long-range quantum entanglement in QSLs promotes the emergence of non-local excitations and topological properties, unveiling unexplored quantum phenomena. The immense fundamental interest in this exotic phase of matter evinces the need for new crystalline designs and novel combinations of experimental methods in the study of QSLs. The present...

Long-term monitoring of existing wind turbine towers and fatigue performance of UHPFRC under compressive stresses

Christophe Thierry Loraux
An increasing number of onshore wind turbines in Europe will reach the end of their relatively short service duration, currently limited to 20 years by the design codes and many owners already wish to extend the service duration of their turbines. Recently published recommendations require the coupled visual inspection and complex aero-elastic models for the safety verification of aging turbines. These methods however still lack accuracy and rely on generic numerical models that are subject...

Hybrid peripheral-spinal neuroprosthesis for refined motor execution after paralysis

Sophie Marie Marthe Wurth
Spinal cord injury (SCI) disrupts the communication between the brain and the spinal circuits responsible for movement, thereby causing severe motor deficits. Current strategies to restore function to paralyzed limbs have separately investigated electrical stimulation of the spinal cord or of the peripheral neuromuscular system. Various neuromodulation strategies, for instance electrical epidural stimulation (EES) of the spinal cord, reactivate spinal circuits below the lesion and enable the generation of locomotor activity. EES targets muscle synergies...

Novel compartment-specific biosensors reveal a complementary subcellular distribution of bioactive Furin and PC7

Pierpaolo Ginefra
Proprotein Convertases (PCs) constitute a family of serine proteases that activate various hormones, growth factors and cell adhesion molecules by mediating endoproteolytic cleavage of their secreted inactive precursors during their transit in the secretory pathway. Their physiological roles in most tissues, in cancer and other diseases have remained nowadays poorly defined, partly because of technical hurdles in clearly distinguishing functionally overlapping PC activities from each other. Related to this, a major unsolved question is where,...

One-shot learning and eligibility traces in sequential decision making

Marco Philipp Lehmann
When humans or animals perform an action that led to a desired outcome, they show a tendency to repeat it. The mechanisms underlying learning from past experience and adapting future behavior are still not fully understood. In this thesis, I study how humans learn from sparse and delayed reward during multi-step tasks. Learning a sequence of multiple decisions, from a reward obtained only at the end of the sequence, requires a mechanism to link earlier...

Automated Taxonomy Induction and its Applications

Amit Gupta
Machine-readable semantic knowledge in the form of taxonomies (i.e., a collection of is-a edges) has proved to be beneficial in an array of NLP tasks including inference, textual entailment, question answering and information extraction. Such widespread utility of taxonomies has led to multiple large-scale manual efforts towards taxonomy induction such as WordNet and Cyc. However, manual construction of taxonomies is time-intensive, and usually, requires substantial annotation efforts by domain experts. Furthermore, the resulting taxonomies suffer...

Effect of localized fire damage on failure mode shifts in sandwich structures

Abraham Elmushyakhi, Elias A. Toubia & Alexander B. Morgan

Design, Modeling, and Control Methods for Fluid-Mediated Programmable Self-Assembly of Resource-Constrained Robotic Modules

Bahar Haghighat
The newly emerged and quickly growing science of nanotechnology has been recognized as one of ``the twenty-first century's great leaps forward in scientific knowledge''. Self-assembly provides a powerful enabling technique for nanotechnology by providing a bottom-up solution as an alternative to the conventional top-down approach in nano-fabrication. Employing self-assembly in nanotechnology seems in fact inevitable. As we try to build ever smaller structures as big as only a few atoms, utilizing tools for putting the...

Mechanical response of sandwich structures based on corrugated composite cores filled with PVC foam

Jin Zhou, Lei Peng, Zhong Wei Guan & Wesley James Cantwell

Experimental study on cracking behavior of glass-FRP reinforced precast concrete sandwich panels

Marcin M. Haffke & Matthias Pahn

Soft impact of laminated glass used for aircraft windshields

Iman Mohaghegian, Yi Wang, Jie Zhou, Long Yu, Xintao Guo, Yue Yan, Maria Charalambides & John P. Dear

Modelling and design of composite sandwich panels under in-plane compression crushing

Yuan Chen & Lin Ye

High power ultraviolet LED illumination systems: coherence properties and applications in photolithography

Johana Bernasconi
Mask-aligner photolithography is a technology used to replicate patterns from a mask to a photosensitive substrate. It is widely used in the fabrication of MEMS and micro-optical components, and for other applications with dimensions in the micrometer range. Traditionally, the light sources used for mask-aligners are high-pressure mercury arc lamps, which emit in the ultraviolet range with peaks at 365nm, 405nm and 435nm, the so-called g-, h- and i- lines. These lamps suffer from several...

Additive Fabrication of Silicon Pillars on Monocrystalline Silicon by Direct Laser Melting

Marie Camille Laëtitia Le Dantec
Additive Manufacturing (AM) is an emerging part production technology that offers many ad-vantages such as high degree of customization, material savings and design of 3D highly complex structures. However, AM is a complex multiphysics process. Therefore, only a limited number of materials can already be commercially used to produce parts and a handful of others are being studied or developed for such process. Consequently, limited knowledge on this process is available, especially concerning materials that...

Explicit simulation of crack growth in honeycomb cores of sandwich structures

Alexander Bugiel, Falk Hähnel & Klaus Wolf

Kazhdan's Property (T) and Property (FH) for measured groupoids

Christophe Michel Gippa
Introduced 50 years ago by David Kazhdan, Kazhdan's Property (T) has quickly become an active research area in mathematics, with a lot of important results. A few years later, this property has been generalized to discrete group actions by Robert J. Zimmer. Then, more recently, Claire Anantharaman-Delaroche has generalized it to measured groupoids. In this work, we will continue to study this property for measured groupoids. We will introduce a Property (T) via compact sets...

Distributed State Estimation and Cooperative Path-Following Under Communication Constraints

Francisco Fernandes Castro Rego
The main topics of this thesis are distributed estimation and cooperative path-following in the presence of communication constraints, with applications to autonomous marine vehicles. To this end, we study algorithms that take explicitly into account the constraints imposed by the communication channel, either by reducing the total number of messages per unit of time or quantizing the information with a reduced number of bits and transmitting it at a fixed rate. We develop a cooperative...

The Intellectual Organisation of History

Giovanni Colavizza
A tradition of scholarship discusses the characteristics of different areas of knowledge, in particular after modern academia compartmentalized them into disciplines. The academic approach is often put to question: are there two or more cultures? Is an ever-increasing specialization the only way to cope with information abundance or are holistic approaches helpful too? What is happening with the digital turn? If these questions are well studied for the sciences, our understanding of how the humanities...

Fracture mechanics methods for assessment of damage tolerance of debonded/disbonded sandwich structures

Christian Berggreen

Measurement of time-dependent CP violation in B0->Dpi decays and optimisation of flavour tagging algorithms at LHCb

Vincenzo Battista
This thesis presents the results of a time-dependent analysis of $B^0\to D^{\mp}\pi^{\pm}$ decays using $3~\rm fb^{-1}$ of proton-proton collision data collected with the LHCb detector at CERN's Large Hadron Collider during Run 1 with a centre-of-mass energy of $7$ (2011) and $8$ (2012) TeV. The LHCb experiment is dedicated to the study of the properties of $b$-flavoured hadrons, in particular $CP$ violation in the $B$ meson system. The Standard Model of Particle Physics describes very...

Shear and foundation effects in SCB sandwich specimen

Leif A. Carlsson, Vishnu Saseendran, Christian Berggreen & Laura J. Duarte Mendoza

Refurbishment of the Vorderrhein-roadbridge near Valendas implementing a GFRP-wood hybrid slab

Thomas J.E. Ekwall & Gernot Weis

A hybrid cementitious based-G/CFRP sandwich panel: concept, design and initial outcomes

José Sena-Cruz, Gonçalo Escusa, Diogo Figueira, Honeyeh Ramezansefat, Eduardo Pereira, Isabel Valente & Joaquim Barros

Network-Compute Co-Design for Distributed In-Memory Computing

Alexandros Daglis
The booming popularity of online services is rapidly raising the demands for modern datacenters. In order to cope with data deluge, growing user bases, and tight quality of service constraints, service providers deploy massive datacenters with tens to hundreds of thousands of servers, keeping petabytes of latency-critical data memory resident. Such data distribution and the multi-tiered nature of the software used by feature-rich services results in frequent inter-server communication and remote memory access over the...

Registration Year

  • 2018

Resource Types

  • Text