3D Simulation of Fin Geometry Influence on Corner Effect in Multifin Dual and Tri-Gate SOI-Finfets

In this work the corner effect sensitivity to fin geometry variation in multifin dual and tri-gate SOI-FinFETs is studied through a commercial, three-dimensional numerical simulator ATLAS from Silvaco International. These devices are compatible with conventional silicon integrated circuit processing, but offer superior performance as the device is scaled into the nanometer range. This study aims wider to use multiple fins between the source and drain regions. The results indicate that for both multifin double and triple gate FinFETs, the corner effect does not lead to an additional leakage current and therefore does not deteriorate the SOI-FinFET performance

Développement de la méthode de Monte Carlo pour le calcul des interactions et du transport électrique dans les semi-conducteurs ternaires

Development of the Monte Carlo method for the calculation of theinteractions and electric transport in the ternary semiconductorsIn this paper; we show the interest of the heterostructures initially, then the need for using a numerical method and in particular that of Monte Carlo, to calculate electric transport in the semiconductors. We justify also the composition of our ternary semiconductor AlxGa1-xAs. Afterwards; we give the principle and the implementation of the method which we adapted to our case, while trying to approach us reality. We apply finally this method to calculate the interactions and electric transport in our compound

Optical cooling and trapping of highly magnetic atoms: The benefits of a spontaneous spin polarization

From the study of long-range-interacting systems to the simulation of gauge fields, open-shell Lanthanide atoms with their large magnetic moment and narrow optical transitions open novel directions in the field of ultracold quantum gases. As for other atomic species, the magneto-optical trap (MOT) is the working horse of experiments but its operation is challenging, due to the large electronic spin of the atoms. Here we present an experimental study of narrow-line Dysprosium MOTs. We show that the combination of radiation pressure and gravitational forces leads to a spontaneous polarization of the electronic spin. The spin composition is measured using a Stern-Gerlach separation of spin levels, revealing that the gas becomes almost fully spin-polarized for large laser frequency detunings. In this regime, we reach the optimal operation of the MOT, with samples of typically $3\times 10^8$ atoms at a temperature of 15\,$\mu$K. The spin polarization reduces the complexity of the radiative cooling description, which allows for a simple model accounting for our measurements. We also measure the rate of density-dependent atom losses, finding good agreement with a model based on light-induced Van der Waals forces. A minimal two-body loss rate $\beta\sim 2\times10^{-11}\,$cm$^{3}$/s is reached in the spin-polarized regime. Our results constitute a benchmark for the experimental study of ultracold gases of magnetic Lanthanide atoms.Comment: 21 pages, 9 figure

An actively constrained two degree-of-freedom manipulator for passive deployment applications

A two degree-of-freedom manipulator using actively constrained revolute joints is presented in this paper. Each revolute joint drive mechanism consists of two motor-driven worms coupled to a single worm wheel. A mathematical model of the manipulator system is used in order to develop a computed-torque control algorithm. Experimental results show that the position of the end-effector can be successfully controlled to track a path generated from a user-input force command signal while cancelling backlash at the gear interface. This system has been designed for the purpose of following a predefined path under the direct physical control of the user. The joint mechanism and control strategy used in this paper allow for backlash to be continuously cancelled. The safety of the user is ensured by enabling joint motions only if a user force is applied, and this force is in a direction that allows the controller to restrict joint motion along a predefined path

Drilling resistance: A method to investigate bone quality

Purpose: Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill-bit penetration and drill-bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. Methods: This study demonstrates that bone drilling force data if recorded in-vivo, during the repair of bone fractures, can provide information about the quality of the bone. To understand the variability and anisotropic behaviour of cortical bone tissue, specimens cut from three anatomic positions of pig and bovine were investigated at the same drilling speed and feed rate. Results: The experimental results showed that the drilling force does not only vary from one animal bone to another, but also vary within the same bone due to its changing microstructure. Drilling force does not give a direct indication of bone quality; therefore it has been correlated with screw pull-out force to provide a realistic estimation of the bone quality. A significantly high value of correlation (r2 = 0.93 for pig bones and r2 = 0.88 for bovine bones) between maximum drilling force and normalised screw pull-out strength was found. Conclusions: The results show that drilling data can be used to indicate bone quality during orthopaedic surgery

Etude théorique du transport électronique par la simulation Monte Carlo dans le quaternaire In0.863Ga0.137As0.3P0.7

Afin de simuler le comportement d'un laser à semi-conducteur, nous devons disposer de modèles mathématiques décrivant de façons aussiprécise que possible les propriétés physiques des matériaux considérés.Ces dernières années plusieurs recherches ont été consacrées aux lasers de type InGaAsP-InP. Plusieurs paramètres physiques sont connus avec une précision plus ou moins satisfaisante. Nous avons tenté, de reproduire au mieux l'ensemble des mesures rapportées dans la littérature et d’étudier le phénomène de transport dans les semiconducteurs quaternaire. Pour cela nous avons effectué des simulations microscopiques, basées sur la méthode Monte Carlo. Nous avonsappliqué cette méthode au cas du quaternaire "In0.863Ga0.137As0.3P0.7-InP", considérant une bande de conduction à trois vallées (Γ, L, X), isotropes et quasi paraboliques. Les interactions prises en compte sont dues aux phonons optiques polaires, optiques non polaires, acoustiques, intervallées, piézoélectriques ainsi que les interactions d'alliage et sur impuretés ionisées. Dans un premier temps, nous présentons l’ensemble des résultats obtenus par la simulation de Monte Carlo dans l'In0.863Ga0.137As0.3P0.7 en régime stationnaire. Nous considérons ensuite les effets liés à l’application d’un champ électrique variant très rapidement en fonction du temps. Nous étudions en particulier les phénomènes non stationnaires qui font leur apparition dans le matériau quaternaire.Mots-clés : simulation de Monte Carlo, In0.863Ga0.137As0.3P0.7, interaction, composants électroniques

Finite element modeling and experimentation of bone drilling forces

Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill breakthrough, excessive heat generation, and mechanical damage to the bone. This paper presents a 3D finite element (FE) model for prediction of thrust forces experienced during bone drilling. The model incorporates the dynamic characteristics involved in the process along with the accurate geometrical considerations. The average critical thrust forces and torques obtained using FE analysis, for set of machining parameters are found to be in good agreement with the experimental results

Drilling in cortical bone: a finite element model and experimental investigations

Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill-bit breakthrough, excessive heat generation, and mechanical damage to the bone. An experimental and computational study of drilling in cortical bone has been conducted. A 3D finite element (FE) model for prediction of thrust forces experienced during bone drilling has been developed. The model incorporates the dynamic characteristics involved in the process along with geometrical considerations. An elastic-plastic material model is used to predict the behaviour of cortical bone during drilling. The average critical thrust forces and torques obtained using FE analysis are found to be in good agreement with the experimental results