Publications associées à Screw axis

Interactions of Cavitation Bubbles with Deformable Interfaces

Cavitation is a topic that has long been of interest due to the large and growing range of applications associated with it. This is mainly because the collapse of cavitation bubbles releases a considerable amount of energy into the surrounding environment. ...

EPFL2023

Geometric Algebra for Optimal Control With Applications in Manipulation Tasks

Sylvain Calinon, Tobias Löw

Many problems in robotics are fundamentally problems of geometry, which have led to an increased research effort in geometric methods for robotics in recent years. The results were algorithms using the various frameworks of screw theory, Lie algebra, and d ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Screw vs. edge dislocation strengthening in body-centered-cubic high entrophy alloys and implications for guided alloy design

William Curtin, Francesco Maresca, Carolina Baruffi

Body-centered-cubic (BCC) high entropy alloys (HEAs) can show exceptionally high strength up to high temperatures. Mechanistic theories are needed to guide alloy discovery within the immense multicomponent HEA compositional space. Here, two new theories fo ...

SPRINGER HEIDELBERG2022

Experimental studies of the equilibrium and out-of-equilibrium electronic structure of non-symmorphic topological materials

Gianmarco Gatti

Symmetry and topology are fundamental properties of nature. Mathematics provides us with a general framework to understand these concepts. On one side, symmetry describes the invariance properties of an object for specific transformations. On the other sid ...

EPFL2020

High-order based revelation of bifurcation of novel Schatz-inspired metamorphic mechanisms using screw theory

Huijuan Feng

The revelation of mechanism bifurcation is essential in the design and analysis of reconfigurable mechanisms. The first- and second-order based methods have successfully revealed the bifurcation of mechanisms. However, they fail in the novel Schatz-inspire ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Theoretical study of an electrostatically actuated torsional microsensor for biological applications

We develop an analytical formulation to calculate the induced resonance frequency shifts of an electrostatically actuated torsional microsensor due to an added bio-mass (E. coli). Based on a lumped-parameter model, we investigate the static and the linear ...

SPRINGER2018

Vehicle Having a High Clearing Capability

Thomas Estier

The invention relates to a vehicle which includes at least four wheels and a base. Said wheels are attached in pairs at the base via connections and form a bogie consisting of a pair of wheels. Said bogies are rotatably hinged onto the base such that the p ...

2017

Parametric Experimental Study and Design of Experiment Modelling of Sapphire Grinding

Daniel Sage

This study investigates and models the grinding process of single crystal sapphire. Five parameters: the wheel speed, the feed speed, the vertical feed, the ultrasonic assistance and the crystallographic direction were considered via a design of experiment ...

Elsevier2017

Bloch theorem with revised boundary conditions applied to glide and screw symmetric, quasi-one-dimensional structures

Florian Paul Robert Maurin

Bloch theorem is useful for analyzing wave propagation in periodic systems. It has been widely used to determine the energy bands of various translationally-periodic crystals and with the advent of nanoscale structures like nanotubes, it has been extended ...

Elsevier2016

Muscle Moment-Arms: A Key Element in Muscle-Force Estimation

Alexandre Terrier, Philippe Müllhaupt, Alain Farron, Christoph Anselm Engelhardt, David Ingram

A clear and rigorous definition of muscle moment-arms in the context of musculoskeletal systems modelling is presented, using classical mechanics and screw theory. The definition provides an alternative to the tendon excursion method, which can lead to inc ...

Taylor & Francis2015

Variability of the pullout strength of cancellous bone screws with cement augmentation

Dominique Pioletti

Background: orthopaedic surgeons often face clinical situations where improved screw holding power in cancellous bone is needed. Injectable calcium phosphate cements are one option to enhance fixation. Methods: paired screw pullout tests were undertaken in ...

Elsevier2015

Torque magnetometry study of magnetically ordered state and spin reorientation in the quasi-one-dimensional S=1/2 Heisenberg antiferromagnet CuSb2O6

Helmuth Berger

The antiferromagnetically ordered state of the monoclinic quasi-one-dimensional S = 1/2 Heisenberg antiferromagnet CuSb2O6 was studied combining torque magnetometry with a phenomenological approach to magnetic anisotropy. This system is known to have a num ...

Amer Physical Soc2015

Bloch Theorem With Revised Boundary Conditions Applied To Glide Plane And Screw Axis Symmetric, Quasi-One-Dimensional Structures

Alessandro Spadoni, Florian Paul Robert Maurin

Bloch theorem provides a useful tool to analyze wave propagation in periodic systems. It has been widely used in physics to obtain the energy bands of various translationally-periodic cristals and with the advent of nanosciences like nanotubes, it has been ...

Int Center Numerical Methods Engineering2014

A Natural Helical Crystal Lattice Model for Carbon Nanotubes

Nicola Marzari

We propose a novel helical crystal lattice model for chiral and achiral carbon nanotubes (CNTs) where the unit cell and the helical crystal vector are defined in a unique and systematic manner for arbitrary CNTs. The small unit cell of this helical crystal ...

Amer Chemical Soc2013

Adjustable fixation system for neurosurgical devices

Jean-Philippe Thiran, Rémi Charrier, David Haag

The system comprises at least a support (5) to be attached to a patient by fixing means (4), said support having an outer thread (7), a first nut (9) with an inner thread (11 ) cooperating with said outer thread (7) and an anchor having a spherical bottom ...

2012

Magnetic active-valve micropump actuated by a rotating magnetic assembly

Martinus Gijs, Meng Shen

We report on a high-efficiency and self-priming active-valve micropump consisting of a microfluidic chamber structure in glass that is assembled with a polydimethylsiloxane (PDMS) elastic sheet. The latter comprises two valving membranes and a central pump ...

Elsevier2011

Tightening force and torque of nonlocking screws in a reverse shoulder prosthesis

Dominique Pioletti, Alexandre Terrier, Alain Farron, Francesco Merlini, Miguel Gortchacow, Stephanie Kochbeck

Background. Reversed shoulder arthroplasty is an accepted treatment for glenohumeral arthritis associated to rotator cuff deficiency. For most reversed shoulder prostheses, the baseplate of the glenoid component is uncemented and its primary stability is p ...

Elsevier2010

Nonlinear Stability of Riemann Ellipsoids with Symmetric Configurations

Using modern differential geometric methods, we study the relative equilibria for Dirichlet's model of a self-gravitating fluid mass having at least two equal axes. We show that the only relative equilibria of this type correspond to Riemann ellipsoids for ...

Springer-Verlag2009

On Hermitian Pfister Forms

Let K be a field of characteristic different from 2. It is known that a quadratic Pfister form over K is hyperbolic once it is isotropic. It is also known that the dimension of an anisotropic quadratic form over K belonging to a given power of the fundamen ...

2008

Velocity Scheduling Controller for a Nonholonomic Mobile Robot

Dominique Bonvin, Philippe Müllhaupt, Davide Buccieri

An improvement over classical dynamic feedback linearization for the control of a nonholonomic mobile robot is proposed. The use of a state extension of higher dimension than in the case of dynamic feedback linearization helps reject constant disturbances ...

2006