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flexible Polyimide Microelectrodes Array for Transcorneal Electrical Stimulation

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Journal of Biomedical Science and Engineering 2015年第8期8卷 544-554页

作者： Luis Nino de-Rivera fidel W.Pérez-Tovar Jorge Santiago Amaya félix gil carrasco Instituto Politécnico Nacional(IPN México)ESIME UPCMéxicoMéxico Asociación para evitar la ceguera en México I.A.P.Hospital“Luis Sánchez Bulnes”(APEC)MéxicoD.F.México

The relationship between the parameters of Transcorneal Electrical Stimulation (TES) and its neuro-protective effect of TES on axotomised Retinal Ganglion Cells (RGCs) is still unclear. This work discusses the design strategy of a new non conventional TES stimulator, the micro fabrication processes and characterization of an array of MEMS microelectrodes over a flexible polymer layer substrate to stimulate the human cornea. The micro-array of electrodes, over a flexible smooth biocompatible polyimide substrate, fine tunes the curvature of the cornea. This tool can help researchers to define the optimal electric stimulation parameters required in TES.

关键词： Microelectrodes flexible Polymide Microelectrodes Transcorneal Electrical stimulation

A two-stage approach for managing actuators redundancy and its application to fault tolerant flight control

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Chinese Journal of Aeronautics 2015年第2期28卷 469-477页

作者： Zhong Lunlong félix Mora-Camino Tianjin Key Laboratory for Advanced Signal and Image Processing Civil Aviation University of China Automation Research Group of MAIAA ENAC Toulouse University

In safety-critical systems such as transportation aircraft, redundancy of actuators is introduced to improve fault tolerance. How to make the best use of remaining actuators to allow the system to continue achieving a desired operation in the presence of some actuators failures is the main subject of this paper. Considering that many dynamical systems, including flight dynamics of a transportation aircraft, can be expressed as an input affine nonlinear system, a new state repre- sentation is adopted here where the output dynamics are related with virtual inputs associated with the intended operation. This representation, as well as the distribution matrix associated with the effectiveness of the remaining operational actuators, allows us to define different levels of fault tol- erant governability with respect to actuators＇ failures. Then, a two-stage control approach is devel- oped, leading frst to the inversion of the output dynamics to get nominal values for the virtual inputs and then to the solution of a linear quadratic （LQ） problem to compute the solicitation of each operational actuator. The proposed approach is applied to the control of a transportation air- craft which performs a stabilized roll maneuver while a partial failure appears. Two fault scenarios are considered and the resulting performance of the proposed approach is displayed and discussed.

关键词： Actuator allocation fault tolerant control flight control Linear quadratic (LQ)problem Nonlinear control

Are the number and size of scales in Liolaemus lizards driven by climate?

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Integrative Zoology 2018年第5期13卷 579-594页

作者： María JoséTULLI félix BCRUZ Unidad Ejecutora Lillo(UEL-CONICET) Instituto de HerpetologíaFundación Miguel LilloSan Miguel de TucumánTucumánArgentina Instituto de Investigaciones en Biodiversidad y Medioambiente(INIBIOMA)CONICET-UNCOMA BarilocheRío NegroArgentina

Ectothermic vertebrates are sensitive to thermal fluctuations in the environments where they *** buffer these fluctuations,ectotherms use different strategies,including the integument,which is a barrier that minimizes temperature exchange between the inner body and the surrounding *** lizards,this barrier is constituted by keratinized scales of variable size,shape and texture,and its main function is protection,water loss avoidance and *** size of scales in lizards has been proposed to vary in relation to climatic gradients;however,it has also been observed that in some groups of Iguanian lizards it could be related to ***,here,we studied the area and number of scales(dorsal and ventral)of 60 species of Liolaemus lizards distributed in a broad latitudinal and altitudinal gradient to determine the nature of the variation of the scales with climate,and found that the number and size of scales are related to climatic variables,such as temperature and geographical variables as *** evolutionary process that best explained how these morphological variables evolved was the Ornstein–Uhlenbeck *** number of scales seemed to be related to common ancestry,whereas dorsal and ventral scale areas seemed to vary as a consequence of ecological *** fact,the ventral area is less exposed to climate conditions such as ultraviolet radiation or wind and is,thus,under less pressure to change in response to alterations in external *** is possible that scale ornamentation,such as keels and granulosity,may bring some more information in this regard.

关键词： climate variables habitat use Lioalemidae scale traits

Describing failure in geomaterials using second-order work approach

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Water Science and Engineering 2015年第2期8卷 89-95页

作者： franois Nicot félix Darve Institut de Recherche en Sciences et Technologies de l'Environnement et de l'Agriculture(IRSTEA) Erosion Torrentielle Neige et Avalanches (ETNA)Geomechanics GroupGrenoble 38402 France Université Joseph fourier (UJf)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS) Laboratoire SolsSolides Structures et RisquesGrenoble 38041 France

Geomaterials are known to be non-associated materials. Granular soils therefore exhibit a variety of failure modes, with diffuse or localized kinematical patterns. In fact, the notion of failure itself can be confusing with regard to granular soils, because it is not associated with an obvious phenomenology. In this study, we built a proper framework, using the second-order work theory, to describe some failure modes in geomaterials based on energy conservation. The occurrence of failure is defined by an abrupt increase in kinetic energy. The increase in kinetic energy from an equilibrium state, under incremental loading, is shown to be equal to the difference between the external second-order work,involving the external loading parameters, and the internal second-order work, involving the constitutive properties of the material. When a stress limit state is reached, a certain stress component passes through a maximum value and then may decrease. Under such a condition, if a certain additional external loading is applied, the system fails, sharply increasing the strain rate. The internal stress is no longer able to balance the external stress, leading to a dynamic response of the specimen. As an illustration, the theoretical framework was applied to the well-known undrained triaxial test for loose soils. The influence of the loading control mode was clearly highlighted. It is shown that the plastic limit theory appears to be a particular case of this more general second-order work theory. When the plastic limit condition is met, the internal second-order work is nil. A class of incremental external loadings causes the kinetic energy to increase dramatically, leading to the sudden collapse of the specimen, as observed in laboratory.

关键词： failure in geomaterials Undrained triaxial loading path Second-order work Kinetic energy Plastic limit condition Control parameter

Do Rules and Patterns Affect Design Maintainability?

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Journal of Computer Science & Technology 2009年第2期24卷 262-272页

作者： Javier Garzás félix García Mario Piattini Kybele Consulting Madrid Spain Department of Information Technologies and Systems-Escuela Superior de Informáica University of Castilla-La Mancha Alarcos Research Group-Institute of Information Technologies and Systems Department of Information Technologies and Systems-Escuela Superior de Informáica University of Castilla-La Mancha

At the present time, best rules and patterns have reached a zenith in popularity and diffusion, thanks to the software community＇s efforts to discover, classify and spread knowledge concerning all types of rules and patterns. Rules and patterns are useful elements, but many features remain to be studied if we wish to apply them in a rational manner. The improvement in quality that rules and patterns can inject into design is a key issue to be analyzed, so a complete body of empirical knowledge dealing with this is therefore necessary. This paper tackles the question of whether design rules and patterns can help to improve the extent to which designs are easy to understand and modify. An empirical study, composed of one experiment and a replica, was conducted with the aim of validating our conjecture. The results suggest that the use of rules and patterns affect the understandability and modifiability of the design, as the diagrams with rules and patterns are more difficult to understand than non-rule/pattern versions and more effort is required to carry out modifications to designs with rules and patterns.

关键词： design patterns and rules maintainability software quality object-oriented design

Understanding the neighborhoods’in-between spaces on spatial perception,social interaction,and security

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frontiers of Architectural Research 2024年第1期13卷 21-36页

作者： Lizeth félix Mariel Organista Autonomous University of Baja California Ensenada 22860Mexico

This study reflects on the impact that the neighborhoods’in-between spaces have on:spatial perception,social interaction,and *** sites,characterized by their abandonment and deterioration,can also be seen as crucial spaces of opportunity for cities,in the architectural,urban and landscape *** paper aims to analyze the sociospatial relationships in the neighborhoods’in-between spaces and examine the impact of inbetween space configuration on urban *** investigation draws on a survey of perception to residents about the requirements for a suitable social interaction in these *** study was developed in a neighborhood in the city periphery,characterized by their social dynamics and location in a nature conservation *** findings indicate that the appropriation process,activities,and collective practices are dependent on the spatial legibility,in this case when this increases,gives rise to improve the habitability and the rehabilitation of the in-between ***,the lack of design on in-between spaces substantially affects the use of these spaces and the social interaction among residents.

关键词： In-between spaces Socio-spatial relationships Habitability Neighborhoods Security

A 3D Numerical Study of LO_2/GH_2 Supercritical Combustion in the ONERA-Mascotte Test-rig Configuration

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Journal of Thermal Science 2016年第1期25卷 97-108页

作者： Abdelkrim Benmansour Abdelkrim Liazid Pierre-Olivier Logerais Jean-félix Durastanti Laboratory LTE ENP-OranBP 1523 El Mnaouer 31000Oran Algeria Universite de Paris-Est CERTESIUT de Senartrue Georges Charpak77567 LieusaintFrance

Cryogenic propellants LOx/H2 are used at very high pressure in rocket engine combustion. The description of the combustion process in such application is very complex due essentially to the supercritical regime. Ideal gas law becomes invalid. In order to try to capture the average characteristics of this combustion process, numerical computations are performed using a model based on a one-phase multi-component approach. Such work requires fluid properties and a correct definition of the mixture behavior generally described by cubic equations of state with appropriated thermodynamic relations validated against the NIST data. In this study we consider an alternative way to get the effect of real gas by testing the volume-weighted-mixing-law with association of the component transport properties using directly the NIST library data fitting including the supercritical regime range. The numerical simulations are carried out using 3D RANS approach associated with two tested turbulence models, the standard k-Epsilon model and the realizable k-Epsilon one. The combustion model is also associated with two chemical reaction mechanisms. The first one is a one-step generic chemical reaction and the second one is a two-step chemical reaction. The obtained results like temperature profiles, recirculation zones, visible flame lengths and distributions of OH species are discussed.

关键词： Rocket engine non-premixed combustion supercritical regime H2-O2 flame transport properties

High-Risk Congenital Coronary Abnormalities in Patients with Bicuspid Aortic Valve

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Congenital Heart Disease 2021年第2期16卷 141-146页

作者： félix Collard Dimitrios Buklas Pascale Maragnes fabien Labombarda Department of Cardiology CHU de CaenCaen14000France Department of Heart Surgery CHU de CaenCaen14000France

Objective:Abnormal coronary artery origin(ACAO)from the opposite sinus with inter-arterial course of the ectopic proximal vessel is associated with the greatest potential for clinical manifestations,specifically sudden *** remain limited regarding the association between bicuspid aortic valve(BAV)and this potentially dangerous coronary variant reported in up to 0.6%in the general *** investigated the frequency of this high-risk ACAO with inter-arterial course in our surgical series of BAV *** and Results:We conducted a retrospective study to identify BAV patients with ACAO and inter-arterial course who underwent elective aortic valve/root surgery between 2010 and 2019 in our tertiary center.A total of 279 consecutive patients with BAV were *** these,four patients(1.4%)had ACAO with inter-arterial *** patients had abnormal right coronary artery arising from the theoretical opposite coronary sinus with intramural *** fourth patient presented an abnormal left coronary artery from a single coronary artery arising from the theoretical right coronary sinus with a long inter-arterial ***:Our results from a single-center experience support high-risk ACAOS may be more frequently diagnosed in BAV patients,especially in surgical series,justifying a careful preoperative assessment.

关键词： Congenital heart disease coronary artery bicuspid aortic valve

Optimization of room-and-pillar dimensions using automated numerical models

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International Journal of Mining Science and Technology 2019年第5期29卷 797-801页

作者： Gian franco Napa-García Tais Renata Camara Vidal félix Navarro Torres Mining Instituto Tecnológico ValeSanta LuziaMG 33040-900Brazil Exploration and Mineral Projects VALE S.A.Santa LuziaMG 33040-900Brazil

This paper presents an optimization methodology for the geometric configuration of a room–and–pillar mining project,considering safety and operational restrictions while maximizing ore *** underground manganese mine was chosen as a case study to investigate the capabilities of the presented methodology.A software package(OPTIMINE)was implemented to address the computational demand in an automated ***–dimensional finite difference analyses were performed in fLAC3D and used as implicit functions to consider safety in terms of the factor of safety and room *** obtained results showed that recovery could be increased from 44%to more than 80%in a safe manner.

关键词： Optimization Safety Room and pillar mining Ore recovery 3D numerical modeling