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Berthet H.,Schlumberger | Jundt J.,Schlumberger | Durivault J.,Schlumberger | Mercier B.,School of Engineering in Information and Communication Science and Technology | Angelescu D.,School of Engineering in Information and Communication Science and Technology
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2011

We describe a thermal microflowrate sensor for measuring liquid flow velocity in microfluidic channels, which is capable of providing a highly accurate response independent of the thermal and physical properties of the working liquid. The sensor consists of a rectangular channel containing a heater and several temperature detectors microfabricated on suspended silicon bridges. Heat pulses created by the heater are advected downstream by the flow and are detected using the temperature detector bridges. By injecting a pseudo-stochastic thermal signal at the heater and performing a cross correlation between the detected and the injected signals, we can measure the single-pulse response of the system with excellent signal-to-noise ratio and hence deduce the thermal signal time-of-flight from heater to detector. Combining results from several detector bridges allows us to eliminate diffusion effects, and thus calculate the flow velocity with excellent accuracy and linearity over more than two orders of magnitude. The experimental results obtained with several test fluids closely agree with data from finite element analysis. We developed a phenomenological model which supports and explains the observed sensor response. Several fully functional sensor prototypes were built and characterized, proving the feasibility and providing a critical component to microfluidic lab-on-chip applications where accurate flow measurements are of importance. © 2011 The Royal Society of Chemistry.


Yu Y.F.,Nanyang Technological University | Yu Y.F.,Data Storage Institute Singapore | Yu Y.F.,School of Engineering in Information and Communication Science and Technology | Zhang J.B.,Data Storage Institute Singapore | And 2 more authors.
Applied Physics Letters | Year: 2012

This paper reports optical-force-induced bistability in a nanomachined ring resonator system. It consists of two ring resonators and a bus waveguide, whereby each ring resonator has a free-hanging arc that is perpendicularly deformable by an optical force and changes the effective refractive index of the system. Therefore, an optical bistability is induced into the nanomachined ring resonator system, in which the bistability band can reach 0.3 nm and 0.68 nm in the ring resonators 1 and 2, respectively. It has potential applications in optical signal processing area, such as all-optical switching and opto-mechanical memory. © 2012 American Institute of Physics.


Pirngruber G.D.,French Institute of Petroleum | Guillou F.,French Institute of Petroleum | Gomez A.,French Institute of Petroleum | Clausse M.,IRSTEA | Clausse M.,School of Engineering in Information and Communication Science and Technology
International Journal of Greenhouse Gas Control | Year: 2013

CO2 capture processes based on dry solid sorbents have been praised as a very attractive alternative to absorption by amine solvents (in particular monoethanolamine) in terms of energy consumption. The present paper critically analyzes these very optimistic predictions. It presents a theoretical analysis of three different temperature swing adsorption (TSA) processes: (i) a fixed bed, (ii) an isothermal fluidized bed and (iii) an adiabatic fluidized bed. The solid sorbent is supposed to be an amine immobilized on a support material. A high-level estimation of the energy consumption of the three processes shows that the fixed bed process would be by far the most interesting option, because the thermodynamic driving force for adsorption is higher in the fixed bed. The performances of both the fixed and fluidized bed process dramatically improve if the adsorption step is operated under close to isothermal conditions. Heat transfer in a fixed bed is much slower than in a fluidized bed. Providing the heat exchange area required for isothermal operation is challenging in the fixed bed, but not impossible according to our rough estimations. The paper also defines the adsorption properties (adsorption constant, adsorption capacity, heat of adsorption) of the optimal solid sorbent. © 2013 Elsevier Ltd.


Sabry Y.M.,School of Engineering in Information and Communication Science and Technology | Sabry Y.M.,Si-Ware Systems | Saadany B.,Si-Ware Systems | Khalil D.,Si-Ware Systems | And 3 more authors.
Light: Science and Applications | Year: 2013

Miniaturized optical benches process free-space light propagating in-plane with respect to the substrate and have a large variety of applications, including the coupling of light through an optical fiber. High coupling efficiency is usually obtained using assembled micro-optical parts, which considerably increase the system cost and integration effort. In this work, we report a high coupling efficiency, monolithically integrated silicon micromirror with controlled three-dimensional (3D) curvature that is capable of manipulating optical beams propagating in the plane of the silicon substrate. Based on our theoretical modeling, a spherical micromirror with a microscale radius of curvature as small as twice the Gaussian beam Rayleigh range provides a 100% coupling efficiency over a relatively long optical path range. Introducing dimensionless parameters facilitates the elucidation of the role of key design parameters, including the mirror's radii of curvature, independent of the wavelength. A micromachining method is presented for fabricating the 3D micromirror using fluorinated gas plasmas. The measured coupling efficiency was greater than 50% over a 200-μm optical path, compared to less than 10% afforded by a conventional flat micromirror, which was in good agreement with the model. Using the 3D micromirror, an optical cavity was formed with a round-trip diffraction loss of less than 0.4%, resulting in one order of magnitude enhancement in the measured quality factor. A nearly 100% coupling was also estimated when matching the sagittal and tangential radii of curvature of the presented micromirror's surface. The reported class of 3D micromirrors may be an advantageous replacement for the optical lenses usually assembled in silicon photonics and optical benches by transforming them into real 3D monolithic systems while achieving wideband high coupling efficiency over submillimeter distances. © 2013 CIOMP. All rights reserved.


Ben Gaid M.E.M.,French Institute of Petroleum | Cela A.,School of Engineering in Information and Communication Science and Technology
Automatica | Year: 2010

In many situations, control applications have to exchange information through limited bandwidth communication channels, which affect their behavior. For that reason, there is a strong need for methods that maximize the relevancy of the exchanged control signals. In general, increasing control signals' update frequency improves the disturbance rejection abilities whereas increasing their quantization precision improves the steady state performance. However, when the bandwidth is limited, increasing the update frequency necessitates the reduction of the quantization precision and vice versa. Motivated by these observations, and focusing on the uplink bandwidth limitations, an approach for the dynamical online state feedback assignment of control inputs' quantization precision and update rate is proposed. This approach, which is based on the model predictive control technique, enables us to choose the update rate and the quantization levels of control signals from a predefined set, in order to optimize the control performance. Practical stability properties of the approach are then studied. Finally, the effectiveness of the proposed method is illustrated on a simulation example. © 2010 Elsevier Ltd. All rights reserved.


Grant
Agency: Cordis | Branch: FP7 | Program: JTI-CS | Phase: JTI-CS-2010-5-ECO-02-006 | Award Amount: 698.86K | Year: 2011

The SEPDC project will conceive, design and manufacture an Electrical Test Bench (ETB) to be used by airframers to support verification activities over different aircraft electrical architectures (Green Regional Aircraft, Green Business Jet and Green rotorcraft). The SEPDC project will feature a smart HVDC network in charge of the electrical power distribution with the capability to integrate different electrical starter-generators and power-end consumers. The HVDC network will be based on a modular and reconfigurable architecture to meet the variety of different electrical aircraft topologies. Thus, the key connection elements both for generators and loads will be easily exchangeable electromechanical components refer to as RACKS. The innovative concept of smart electrical power distribution system (SEPDC) to develop will be based on synchronized measurements and controls of contactors from a single control unit integrated in a single engineering interface.


Li X.-G.,Northeastern University China | Niculescu S.-I.,CNRS Laboratory of Signals & Systems | Cela A.,School of Engineering in Information and Communication Science and Technology | Wang H.-H.,Northeastern University China | Cai T.-Y.,Northeastern University China
IEEE Transactions on Automatic Control | Year: 2013

Obtaining the Puiseux series of multiple imaginary (characteristic) roots (MIRs) is a fundamental issue in the stability analysis of timedelay systems. However, to the best of the authors' knowledge, this issue has not been fully investigated up to date. This note focuses on the Puiseux series expansion of MIRs of linear time-invariant systems including commensurate delays. For anMIR of anymultiplicity, we propose an algorithm for defining the structure of the Puiseux series, as well as the explicit computation of the corresponding coefficients. By using the proposed method, we can find all the Puiseux series corresponding to all the root loci. © 2012 IEEE.


Chen K.,School of Engineering in Information and Communication Science and Technology | Chan H.P.,City University of Hong Kong
International Journal of Photoenergy | Year: 2012

Silicon oxynitride (SiO xN y, SiON) optical waveguide ring resonator, in which a two-mode interferometer is used to replace the directional coupler in a conventional ring resonator, has been designed and fabricated. Preliminary results exhibit the same of free spectral range of 100GHz but different quality factors of 3700 and 3900 at 1550nm for transverse electric (TE) and transverse magnetic (TM) mode, respectively. The extinction ratio is more than 18dB over the entire C-band, and the insertion loss is lower than 9.5dB for TE and TM mode. Copyright © 2012 Kaixin Chen and Hau Ping Chan.


Patent
Institute Francais Des Science Et Technologies Des Transports, School of Engineering in Information, Communication Science and Technology | Date: 2014-01-17

The invention relates to a method for simultaneously analyzing at least two samples using a chromatography device comprising a chromatography column having an inlet and an outlet, and at least one detector placed at the outlet of the chromatography column, the method comprising steps of: injecting fractions of each independent sample at the inlet of the chromatography column, the fractions of each independent sample being injected according to a specific injection timing sequence derived from a pseudo-random binary sequence associated with said independent sample; recording a signal generated by said detector for a period of time at least equal to a duration of the longest of the specific injection timing sequences; cross-correlating the recorded signal and a derived correlation function, said derived correlation function being derived from the pseudo-random binary sequence associated with one of the independent samples, so as to obtain an individual correlogram signal specific to said independent sample; and analyzing data of interest of the individual correlogram signal so as to obtain an output signal indicative of a composition of the sample.


Patent
School of Engineering in Information, Communication Science, Technology and French Atomic Energy Commission | Date: 2011-06-08

A method for manufacturing an intraocular retinal implant including: providing a mold capable of supporting growth of a layer of doped diamond, the mold including, on one face, elements all depressed or all projecting with respect to the surface of the face, and constituting a pattern cavity for the electrodes of the implant which it is desired to obtain; producing the doped diamond electrodes by growing a layer of doped diamond in all or part of a space occupied by the pattern cavity elements; forming a first insulating layer on the face of the mold including the pattern cavity; producing interconnection lines by depositing an electrically conductive material at least in spaces not covered by the first insulating layer; forming a second insulating layer on the mold face including the pattern cavity, the second layer covering the interconnection lines, the first and second insulating layers forming a flexible plate of the implant; removing the mold.

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