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Two different methods are applied to evaluate the variability of wood ability for Kraft pulping of 25 poplar clones (1-year-old trees). The first one consists in pulping almost all of the wood of each analyzed tree ("macropulpings"). The second one is based on pulping very small wood samples, entire cross sections close to 1 g, taken at 50-cm height (micropulpings and paper microtests). This paper presents the results found separately with the two methods for the following parameters: pulp yield, Kappa (κ) index or permanganate index, and average fiber length. We observed that the evaluations of these parameters deduced by microtests are always well correlated with those obtained from pulping of the whole trees. Moreover, the two methods reveal that the suitability of poplar wood for Kraft pulping is under genetic control at age 1. But for each parameter (especially the ratio (κ index)/(pulping yield)2 and the average weighted fiber length), the differentiation of the clones is never exactly the same. Therefore, it is necessary to slightly modify the micropulping and microtests methodology to evaluate with better accuracy the pulp and paper properties of the whole trees.

Le thuya de Berbérie « Tetraclinis articulata Vahl », espèce résineuse endémique d’Afrique du Nord se trouve généralement sous forme de taillis. La valorisation de la biomasse de thuya, et en particulier de son bois peut être envisagée par la filière papetière par le biais d’une cuisson soude en présence d’anthraquinone (AQ). Le bois jeune de thuya (20 ans) se délignifie bien à l’aide d’une cuisson soude-anthraquinone dans les conditions habituellement appliquées aux résineux avec un temps total de cuisson de 145 min et une température de palier de 165 ◦C. Le rendement brut obtenu est égal à 43,3 % avec un indice Kappa de 33,6. Dans les mêmes conditions de cuisson, le bois âgé (60 ans) peut être lessivé mais se délignifie moins facilement., The coniferous trees of the thuya de Berbérie (Tetraclinis articulata Vahl), from the North Africa (Algeria) is commonly grown as a coppice stand. The biomass of thuya, and especially its wood, can be transformed in pulp by the paper and pulp industry throughout the soda cooking process with the help of the anthraquinone (AQ). The young wood (20 years-old) is well delignified in the soda–anthraquinone process, in the usual conditions applied to the resinous species, in the cooking time schedule of 145 min with the level of 165 ◦C of temperature. The pulp yield of raw material obtained is 43.3% (oven dried wood), with a kappa number of: 33.6. In the same cooking conditions, the mature wood (60 years-old) can be also treated, but with some lower delignification level.

This research work focuses on the development of a new process for the decontamination of municipal wastes incinerators fly ashes. The objective of this study was to evaluate different total and selective precipitation methods for metals removal from ash decontamination leachates. The tested options include 1) use of hydrated lime and caustic soda for selective (pH 5.0) and total (pH 8.5) metal precipitation; 2) addition of different chemicals (H3PO4, Na2S and FeCl3) in a pH range from 6.0 to 9.0. Fly ash decontamination assays using alkaline and acid washing steps were initially performed using optimal conditions previously established. Treated fly ashes respected the standards based on the TCLP leaching test for all studied metals and SPLP. Total metal precipitation tests carried out at pH 8.5 achieve removal yields for all metals > or = 90% using hydrated lime and > or = 83% using caustic soda. Selective precipitation tests alone at pH 5.0 show removal yields > or = 97% for Cr and between 75 and 87% for Al and Pb. Moreover, assays carried out using a stoechiometric addition of Na2S have allowed the separation of Cd (> or = 99%) and Zn (> or = 71%) as metal sulphides (CdS and ZnS). From an economical point of view, the most interesting option seems to be the leachates neutralization at pH 7.0 using Ca(OH)2 combined with the reuse of the treated leachates in the fly ash leaching steps. Metal precipitation cost at pH 7.0 has been estimated to be 22.7 CAN dollars tct-1 using Ca(OH)2, and 26.7 CAN dollars tct-1 using NaOH.

Cet article a pour objectifs : • de présenter un ensemble de bonnes pratiques qui peuvent être inspirées de l'application de la norme internationale ISO 10006 (2003) : « Systêmes de management de la qualité - Lignes directrices pour le management de la qualité dans les projets », dans l'organisation et la réalisation d'une recherche universitaire, débouchant sur une matrice de 54 éléments, • d'illustrer au travers de huit bonnes pratiques la maniêre de mettre en application sur le terrain une telle approche, • de positionner ces concepts dans la stratégie qualité globale de l'institution universitaire concernée, • de suggérer l'élaboration de 3 nouvelles normes internationales en relation avec les démarches qualité en recherche., The objectives of this article are: - to present a set of good practices which can be inspired by the application of the international standard ISO 10006 (2003): "Quality management systems - Guidelines for quality management in projects", in the organization and carrying out university research, leading to a matrix of 54 elements, - to illustrate through eight good practices the way to apply such an approach in the field, - to position these concepts in the overall quality strategy of the university institution concerned, to suggest the development of 3 new international standards in relation to quality approaches in research.

Summary — Consequences of the inclusion of sugar beet pulp in diets for early weaned and growing pigs. The effect of extrusion of wheat and of the inclusion of 6% of sugar beet pulp in a pelleted starter on the performance of the weaned piglet has been studied in two experiments. In the first experiment, 80 crossbred castrated male and female piglets weaned at 21 days of age raised individually y were used in a 2 x 2 factorial arrangement to compare their performance between weaning and 25 kg g live weight. Average feed intake was similar between treatments, but extrusion of wheat had no significant effect on growth performance and feed conversion ratio. The association of normal wheat with sugar beet pulp improved significantly growth rate (P < 0.02) and feed conversion ratio (P < 0.06), in particular during the period following immediatly weaning, ie, 193 vs 156 g/day and 193 vs 2.32, respectively. In the second experiment, 32 crossbred castrated piglets were used to evaluate faecal, then ileal digestibilities of dietary components. Extrusion did not improve digestibility. Ileal digestibility but not faecal digestibility of dry matter and energy was reduced (P < 0.001 ) by the inclusion of sugar beet pulp in the diet. Post-ileal digestibility of all dietary components was higher in animals fed fibrous diet. During the growing-finishing period between 25 and 100 kg live weight, the inclusion of a similar level of 6% of sugar beet pulp in a normal wheat based diet was tested. Piglets of the first experiment were randomly affected to one of the two diets taking into account their previous diet, sex and weight. The average daily gain for the whole period was slighly but not significantly reduced and feed conversion ratio was unchanged in animals receiving sugar beet pulp. However, feed conversion ratio expressed as digeatible energy per kg of body weight gain was reduced in animals receiving beet pulp in their diet. At slaughter, the percentage of lean meat was improved from 52.8 to 54.0% (P < 0.05) as a consequence of a linear decrease in the backfat thickness (P < 0.05) of carcasses of animals receiving sugar beet pulp. No difference in the weight of lean cuts was observed but the use of sugar beet pulp decreased significantly the weight of fat cuts (P < 0.01 It was suggested that for a similar nitrogen retention a reduction in the digestible energy intake reduces the deposition of fatty tissues but the total amount of lean meat in the carcass was not affected by the inclusion of sugar beet in the diet.

Fibrous fractions were prepared from sugar beet pulp (RF) by sequential extractions with potassium oxalate, 0.05 M hydrochloric acid at 85°C and 0.05 m sodium hydroxide at 4°C. The overall composition, polysaccharide structure and some physico-chemical properties (cation exchange capacity, CEC; water holding capacity, WHC; swelling) of each fraction were determined. RF was mostly composed of carbohydrates (66.3 %) with minor amounts of ash, proteins and lignin. The main polysaccharides were highly methylated and acetylated pectins, cellulose and arabinans. The oxalate residue (82.1 % of RF) exhibited only minute differences from RF whereas the acidic and alkaline residues, accounting for 42.8 % and 35.5 % of RF, respectively, were enriched in cellulose and hemicelluloses (xylans, xyloglucans, mannans) and mostly devoid of pectins and arabinans. CEC and WHC of fractions were closely related to the content of unmethylated galacturonic acid residues. The influence of the ionic form of ionisable groups was demonstrated, the Na+ form giving the highest WHC. The ionic strength of the medium can reduce the WHC, especially in the case of the acid and alkali-extracted fibres.

The influence of adding a fibre rich concentrate feed (wheat bran or beet pulp) to a hay-based diet (orchard grass-lucerne mixture; 50/50) upon the rate of passage of digesta of these two fractions (hay and concentrate) was measured in three groups of 8 adult doe rabbits (White New Zealand x California). The three diets composed of either 90% hay, or hay + bran or hay + pulp were offered at two levels of feeding, i.e. ad libitum and 2/3 ad libitum. The retention time of the two main fractions was measured by means of two tracers, i.e. ytterbium-169 bound to hay and cerium-141 to bran or pulp. Animals fed on the 90% hay diet excreted more than 90% of the tracer during the first 24 h. The mean retention time (MRT) of this diet was the shortest (on an average 14.8 h). The addition of pulp or bran increased the MRT of the diet by 2 and 4 h, respectively. Feed restriction led to a 5 to 7 h earlier period of caecotrophy with a subsequent lengthening of the MRT by 2 to 4 h according to groups. The two hay + "concentrate" diets gave almost the same 169Yb and 141Ce excretion curves. Thus, the mean retention time seems to be the same for digesta from hay and "concentrate" (non significant deviations).

The effect of adding a fibre-rich concentrate (wheat bran or beet pulp) to a hay-based diet (cook's foot-lucerne: 50/50) on the apparent digestibility of diets was measured in three groups of 8 adult doe rabbits (New-Zealand White X Californian). Diet composition was as follows: 90% hay only (diet F), hay + bran (diet FS) or hay + pulp (diet FP). Two levels of feeding were tested: ad libitum and 2/3 of ad libitum intake. Addition of wheat bran and especially of beet pulp led to a significant increase in the apparent digestibility of the whole diet. Our results confirm the high digestibility of cell-wall constituents of beet pulp: the apparent digestibility coefficient of hemicellulose in diet FP reached 60% (versus 23% for diet F) and that of cellulose 45% (21% for diet F). Wheat bran supplied digestible hemicellulose (ADC = 48% for diet FS) while the apparent digestibility of bran cellulose was not higher than that of hay (ADC = 22%). This digestive interaction between raw material was accompanied by an interaction with the digestive transit. The less digestible diet (diet F) exhibited the shortest mean residence time (MRT). However, diet FS exhibited the longest residence time whereas it was less digestible than diet FP. These results suggest that, in the rabbit, wheat bran is a transit-regulator as already observed in other species. Measuring apparent digestibility between the 10th and the 16th day of the feed restriction was too early for our doe rabbits. Values measured were not significantly different from those obtained during ad libitum feeding, although the MRT of diets was longer during restricted feeding.

Cet article réfléchit aux pratiques soigneuses d’effilage et raccommodage comme parties intimement constitutives de processus de raisonnement incorporé. Mon point de départ est une ethnographie de dialogues entre la broderie calado et la conception technique. D’où, tout en décrivant l’effilage partiel des tissus destinés au calado et leur raccommodage postérieur par le tissage, j’interroge la double action de ces pratiques : d’abord sur l’ethnographie qui les aborde ; ensuite au sujet des effets de l’ethnographie – elle-même influencée par les pratiques du calado – sur les imaginaires et les attentes des ingénieurs à propos de la conception et du contexte de cet art manuel. Tout au long de cet article, je mets l’accent sur le fait que ce genre de processus d’effilage et raccommodage est constitué par le soin (care) en relation aux corps et aux matérialités. Je prête donc une attention particulière à la manière dont ces processus, traversés par la question du genre selon des manières bien spécifiques, entrelacent histoires d’apprentissage incarné et domestique et formes d’invisibilité ambiguë. This paper reflects on practices of careful unraveling and mending as being intimately constitutive of particular embodied thinking processes. My starting point is an ethnography of the dialogues between calado embroidery and engineering design. Hence, through describing the partial unraveling of fabrics intended to become calado and their subsequent mending through weaving, I question the double agency of these practices : over the ethnography that approaches them, and about the effects of ethnography, affected by calado practices, on engineers’ imaginaries and expectations about design and about the craft’s context. Throughout the paper I emphasize how such processes of unraveling and mending are constituted by care in relation to bodies and materialities. Thus I pay special attention to how these processes intertwine stories about embodied and domestic learning and ambiguous invisibility crosscut by gender in particular ways. Este artículo reflexiona sobre las prácticas cuidadosas de destejido y remiendo como íntimamente constitutivas de procesos particulares de pensamiento incorporado. Mi punto de partida es una etnografía de los diálogos entre el bordado calado y el diseño de ingeniería. Inicio describiendo las prácticas de destejido y destrucción parcial de telas destinadas a ser caladas y su subsiguiente remiendo a través del tejido. Uso esto para cuestionar la doble agencia de estas prácticas : en primer lugar, sobre la etnografía que las estudia y en segundo lugar sobre la forma en que esta etnografía afectada por las prácticas del calado, afecta los imaginarios y expectativas de las y los ingenieros sobre el diseño y sobre el contexto de la artesanía. A lo largo del artículo enfatizo en cómo estos procesos de destejido y remiendo están constituidos por el cuidado en relación con los cuerpos y las materialidades. Para ello, presto especial atención a cómo estos procesos están entrelazados por historias de aprendizaje doméstico e incorporado y por formas de invisibilidad ambigua atravesada por el género de formas particulares.

Cet article présente un panorama général et pratique des brevets français. Un résumé est fait des procédures d’enregistrement en usage de 1791, date de la première loi française, à 1968, avec la législation actuelle. Différentes procédures furent utilisées par l’administration officielle chargée de l’enregistrement de la propriété industrielle. C’est pourquoi les archives diffèrent. Sont présentées les modalités spécifiques d’accès à ces archives. La seconde partie de l’article expose quelques caractéristiques des dessins techniques qu’on trouve dans les brevets. Jusqu’en 1901, quand les dossiers étaient manuscrits, plusieurs types peuvent être observés, dépendant en partie de la connaissance technique des inventeurs. Plus tard, quand les brevets furent imprimés par l’administration pour être publiés, les dessins furent standardisés. Ainsi, les informations fournies par la représentation des inventions est un aspect intéressant des inventions brevetées. This paper presents general and practical information about French patents. A summary of procedures which were in use for patent registration from 1791, with the first French law, up to 1968, with the present legislation, is described. Different procedures were used by official administrations in charge of industrial property registration. Consequently, the archives vary. Specific accesses to these archives are shown. The second part of the paper expounds some aspects of technical drawings which are found on patents. Up to 1901, when files were manuscripts, various designs can be observed, partly depending on technical knowledge of inventors. Later, when all patents were printed by the administration for publication, drawings were standardized. Therefore, information provided by representation of the invention is an interesting face of patented inventions.

The modular model of geared systems presented in this paper makes it possible to simultaneously account for the contact conditions in gears and rolling element bearings. Gears are modeled as two rigid cylinders connected by distributed mesh stiffnesses while ball and roller bearings contribute to the equations of motion as time-varying, non-linear external forces. Solutions are obtained by combining a Newmark time-step integration scheme, a Newton-Raphson method for ball bearing non-linearity and a normal contact algorithm that deals with the contact problem between the teeth. It is found that the static gear-bearing couplings are generally more important than the dynamic couplings with a significant influence of the gear on the bearing response. Finally, it is shown that, in certain conditions, bearings can generate non-linear parametric excitations of the same orders of magnitude as those associated with the meshing of helical gears.Copyright © 2003 by ASME

Because of deflections under load, contacts on tooth flanks can occur outside the theoretical plane of action between nonconjugated profiles especially when tooth modifications are not appropriate. The main objective of the present paper is to introduce an original model of the dynamic behavior of spur gears when submitted to these particular meshing conditions. The pinion and the gear of a pair are modeled as two rigid cylinders linked by stiffnesses and dampers whose amplitudes and orientations vary in order to simulate the evolutions of the meshing conditions. For the sake of simplicity, only three torsional degrees-of-freedom on the pinion, the gear and the motor are considered. The results show that the contacts between non-conjugated flanks lead to a particular dynamic behavior characterized by i) an actual contact ratio larger than the theoretical one, ii) the possibility of impacts at engagement whose amplitudes depend on transmitted loads and speeds.

Le terme interface a-t-il la même signification pour un étudiant en design que pour un étudiant en ingénierie ? Au-delà de la différence de définition, quels savoir-faire doivent déployer ces étudiants pour travailler ensemble dans un contexte étudiant, comme professionnel ? C’est à ce type de question que nous tentons de répondre à travers la conception et la mise en place d’un atelier interdisciplinaire d’enseignement du design interactif. L’atelier regroupe depuis trois ans des designers et des développeurs de différentes écoles, constitués en équipes dans le but de réaliser des prototypes d’interfaces sur une thématique donnée. À défaut d’apporter une recette simple à mettre en place pour résoudre la question de l’interdisciplinarité dans l’enseignement du design, ce texte revient sur les trois années d’expérience accumulée et propose une analyse des erreurs et réussites d’un atelier en constante évolution., Does the word “interface” have the same meaning for a designer and a computer science student? Beyond the different meaning between each of these domains, which mindset a student need to know to work now and in the future with others ? It is keeping those questions in mind that we designed an interdisciplinary workshop on interactive design. In this paper we relate the design and the deployment of this workshop. This workshop gathered during 3 years, designers and developers from different schools to create innovative projects on a specific thematic. In this paper we provide an analysis of this workshop and discuss the issues behind its successes and failures., Interfaces numériques, 3(2), 2014

National audience; Real-time adaptive production control in the flexible manufacturing cell (FMC) is a complex issue that needs to be addressed to realize good performance and high productivity. In this paper, we have considered a support vector machine (SVM)-based simulation approach to resolve a production control problem in an FMC that operates in a dynamic environment. A SVM-based simulation approach chooses the most relevant scheduling rule out of several predefined ones on the basis of the current states of the system. This paper examines and compares the performance of the SVM-based simulation approach with the competent scheduling rules under two different operational environments which are characterized by the uncertainty of demand. We have also developed a Visual Basic-based simulation approach for scheduling of component parts in the context of FMC under different situations. The SVM methodology to control the production offers better performance than the single-rule-based production control system.

International audience; Multiple-Input/Multiple-Output (MIMO) techniques have recently become an important research field for enhancing the performance of in-home Power Line Communication (PLC) systems by exploiting the additional Protective Earth wire. The development of such systems requires an accurate description of the channel noise. In this paper we have presented a model for PLC background noise based on an extensive set of measurements. We have adopted the framework of multivariate time series to model the PLC background noise.This paper employs the Vector Autoregressive (VAR) modeling technique to extract noise model parameters from the measured noise. We have verified the accuracy of the noise model by comparing time and frequency domain correlation of measured and modeled noises.

International audience; In this paper, the authors describe a modeling and design method for a permanent magnet drive used in a power train for Hybrid Electric Heavy Vehicle, based on a Series-Parallel architecture. The hybrid powertrain structure enables high requirements for boost mode of acceleration and full electric mode. A 'Ravigneaux' train was integrated in this hybrid powertrain structure in order to split energy among the vehicle wheels, the thermal engine, the electrical motor and the alternator. To compare the classical simple epicyclic train used in series-parallel Toyota hybrid structure, this 'Ravigneaux' train developed by Nexter group presents a better adaptation to high mechanical constraints (high power and torque) because of its double stages compound structure. Several operation modes of vehicle were analyzed by assuming that the two electrical machines were identical and reversible (they can both operate as a motor or an alternator). In this paper, a simple drive is considered: it deals with a Surface-Mounted Permanent Magnet Synchronous Machine (SMPMSM) and a two level Voltage Source Inverter (VSI). An analytical modeling based on three working points: boost working point, nominal working point and maximal rotation speed working point has been elaborated. The analytical modeling makes it possible to model the physical behavior of different components. It enables to analyze quickly the relationship between the different parameters. A numerical modeling using 2D finite elements is also presented in this paper. The aim of 2D finite elements analysis (2DFEA) is to validate the machine performances obtained by analytical modeling. It enables to model some physical phenomena with a better accuracy, such as magnetic saturation. Generally, the results given by 2DFEA will be closer to experimental results. The control law of the electrical machine was investigated by the way of a single-phased electromechanical modeling. With this model, the flux weakening analysis has been taken into account in order to adapt the motor winding according to the rotation speeds defined in the specifications. The flux weakening was realized by considering mechanical and electrical characteristics linked with power, torque, rotation speed, DC-link voltage, feeding voltage of electrical machine, Id and Iq currents, cyclic inductance, winding resistance, back-electromotive force, phase difference between back electromotive force and phase current... The electrical machine losses have been calculated by neglecting the mechanical losses and PM losses. The machine losses calculation includes the copper losses and the iron losses (eddy currents losses and hysteresis losses). The flux density in the stator yoke and the teeth was evaluated by taking into account the magnetic flux created by permanent magnet and the one created by armature reaction (stator current). The inverter losses were calculated too, by considering the commutation and conduction losses of both diodes and IGBT transistors. Thus, the total losses and the global efficiencies of motor and inverter were evaluated and the best working points can be deduced from those calculations. The previous models enable to evaluate global energy performances of electrical machines and inverters by respecting the constraints defined in the specifications. This methodology is general and can be a first step of a complete power train optimal design, including the electrical drive, the gear, the energy storage units and possibly the internal combustion engine.

The constantly increasing market request of high quality vehicles ask the automotive manufacturers to perform lifetime testing in order to verify the reliability levels of new products. In this paper, we deal with two difficulties in reliability assessment for mechanical parts. On one hand, there is the small number of parts available for testing. On the other hand, there is the problem of wear. In the automotive applications, mechanical components subjected to relative motion of parts have to be designed against wear. In this paper, the Bayesian estimation of Wiener process parameters (usually used to define the degradation process) is studied to improve the estimation accuracy in incorporating the available knowledge on the product. In particular, the finite element results and expert knowledge are considered as “a priori”. For wear prediction by FEM, a model based on Archard law was developed for the brake disc wear.

This paper deals with the monolithic integration around vertical power devices. It presents the work carried out toward the integration of the gate driver within the power device, thanks to a N-MOS technology. It is based on modeling and analysis of correct functional operation of the lateral N-MOS devices thanks static curves. These devices are integrated within the power device thanks to a full share of technological steps between the two types of devices. Thanks to the analysis, a full gate driver is designed and integrated. At the end of the paper, the work is partially validated thanks to experimental results.

This paper deals with face gear design. The goal is to propose a simple formula for predicting the width of the wheel as a function of the main design parameters. A specific software was used to achieve this goal. This numerical tool is able to simulate the geometry and the quasistatic loaded behavior of a face gear. The statistical method used for analyzing the influence of data is described: The design of experiments leads to a simple regression model taking into account the influential parameters and their couplings. In the last part of this paper, the results of the formulas are compared to those of the software and an optimal design is proposed based on the regression model.

This paper introduces a new modeling method suitable for the simulation of shell fracture under impact. This method relies on an entirely meshless approach based on the smoothed particle hydrodynamics (SPH) method. The paper also presents the SPH shell formulation being used as well as the different test cases used for its validation. A plasticity model of the global type throughout the thickness is also proposed and validated. Finally, in order to illustrate the capabilities of the method, fracture simulations using a simplified fracture criterion are presented.

This paper deals with systematically applying a modern principle of designing real-time simulators, namely the HILS (hardware-in-the-loop simulation) concept, consisting in closed-loop connecting physical and software parts, in order to replicate in laboratory conditions the dynamic behaviour of an industrial process. The software part results from modelling the real system to be simulated, whereas the physical part is taken as it is from this system. Principles of HILS systems are first presented, then a systematic design procedure is proposed and illustrated by building a simulator dedicated to variable-speed wind energy conversion systems. The architecture and possibilities of this simulator are suggested by amply discussing the most relevant experimental results. Some concluding remarks finish this paper.

The main idea in this paper deals with the importance of smart machining improvement by introducing physical based understanding. The case of chip formation, in hard turning, is treated via the existence of a direct relationship between serrated-chip morphology simultaneously with force component signals(resulting from a high frequency acquisition) and with the width of facets detected on a workpiece machined surface. The forces component variations can reach several tens of Newton. The shear segmentation of the chip is a high frequency phenomenon. Because it can excites machine-tool, induces insert wear and affects surface integrity, this phenomenon has to be understood and controlled by the smart machining devices. The paper is a contribution by considering an experimental and a numerical approach.

An "open shop" approach characterized by shared resources comprising mobile agents (algorithms) was implemented, in a previous paper, to minimize the total makespan on the whole of the distributed equipment diagnostic processors in order to meet the maximum availability constraints of distributed system. An evaluation of the incidence of the inspection periods of these diagnosis tasks on the maintenance parameters in the case of a reparable wind system of energy production by Monte Carlo simulation is made now. The results show that a period of weaker inspection and a "window" of broader preventive replacement increase the availability of the system and the costs of preventive maintenance, but, on the other hand, the costs of corrective maintenance decrease, thus the need for a trade, Une approche du type « open shop » caractérisée par des ressources partagées constituées d'agents mobiles (les algorithmes) avait été précédemment mise en oeuvre de notre part pour minimiser le makespan total sur l'ensemble des processeurs de diagnostic d'équipements répartis en vue de répondre aux contraintes de disponibilité maximale du système distribué. Une évaluation est maintenant faite de l'incidence des périodes d'inspections de ces tâches de diagnostic sur les paramètres de maintenance dans le cas d'un système éolien réparable de production d'énergie par simulation Monte Carlo. Les résultats montrent qu'une période d'inspection plus faible et une « fenêtre » de remplacement préventif plus large augmentent la disponibilité du système et les coûts de maintenance préventive, mais, d'un autre côté, diminuent les coûts de maintenance corrective, d'où la nécessité d'un compromis. ABSTRACT. An "open shop" approach characterized by shared resources comprising mobile agents (algorithms) was implemented, in a previous paper, to minimize the total makespan on the whole of the distributed equipment diagnostic processors in order to meet the maximum availability constraints of distributed system. An evaluation of the incidence of the inspection periods of these diagnosis tasks on the maintenance parameters in the case of a reparable wind system of energy production by Monte Carlo simulation is made now. The results show that a period of weaker inspection and a "window" of broader preventive replacement increase the availability of the system and the costs of preventive maintenance, but, on the other hand, the costs of corrective maintenance decrease, thus the need for a trade.

A semi-analytical method for the tridimensional thermal-elastic-plastic contact between two hemispherical asperities is proposed. This first part of the paper describes the algorithm used to deal with the normal contact, which can be either load-driven (ld) or displacement-driven (dd). Both formulations use the Conjugate Gradient (CG) method and the Discrete Convolution and Fast Fourier Transform (DC-FFT) technique. A validation of the code is made in the case of the displacement-driven formulation for an elastic-plastic body in contact with a rigid punch, simulating a nano-indentation test. For both formulations (ld and dd) a very good convergence rate is found. Another new feature is the treatment of the contact between two elastic-plastic bodies. The model is first validated through comparison with the Finite Element Method (FEM). The contact pressure distribution, the hydrostatic pressure and the equivalent plastic strain state below the contacting surfaces are also found to be strongly modified in comparison to the case of an elastic-plastic body in contact with a purely elastic body. An application to the tugging between two spherical asperities in simple sliding (dd formulation) is made in part II of the paper.© 2006 ASME

For high-precision mechanisms such as machine tools or gas-turbine engines, which operate at extreme conditions, it is particularly important to accurately predict the behavior of the included bearing. This prediction includes, among other things, its load distribution, stiffness, and power dissipation. Although shaft speeds tend to increase, rings and shaft walls are becoming thinner due to size and weight constraints. Thus, bearing behavior is no longer independent of the housing and ring stiffness. This paper focuses on the problem of elastic ring deformation and certain behaviors of high-speed intershaft cylindrical roller bearings such as heat dissipation, contact pressure, and risk of bearing failure due to scuffing. The paper presents an analytical method to account for the structural deformation of the rings based on Roark's formulas. The elastic deformation of thin cylindrical rings has been introduced in the set of displacement and load equations that describes the bearing equilibrium. A correla...

VTHD is a high-performance IP experimental network. This network and associated research projects have been partially funded by the French government through the French Research Network for Telecommunications (RNRT) in order to support the development of leading-edge network services on the one hand, and test a wide-scale deployment of advanced Internet applications on the other hand. This paper describes the network services that were deemed necessary to support the deployment of innovative applications are described, as well as several of the applications that have been experimented on the network. It also presents a selection of the traffic engineering methods and experiments that have been developed in the course of the VTHD related research projects. This article describes the collective works of members of the project partners, which are represented here by the paper's co-authors., VTHD est un réseau IP expérimental à très haut débit. Ce réseau et les projets de recherche associés ont reçu un financement public par l'intermédiaire du Réseau National de Recherche en Télécommunications (RNRT) dans le but de permettre à la communauté scientifique française de développer des services réseau innovants et de tester le déploiement à grande échelle d'applications Internet avancées. Cet article décrit les services réseau nécessaires pour supporter le déploiement d'applications innovantes, ainsi que les applications qui ont été expérimentées sur le réseau VTHD. Enfin, l'article présente une sélection des méthodes et des expérimentations en matière d'ingénierie de trafic développées lors des projets de recherche associés à VTHD. Cet article décrit les travaux réalisés collectivement par de nombreux membres des institutions partenaires, qui sont représentées ici par les auteurs cosignant l'article.

The paper deals with joint element model used in crashworthiness simulations. The first part of the paper is dedicated to the formulation of a new “global” finite element for spotweld modelling. The mechanical behaviour of the joint is elastic–plastic type and damage is taken into account to model the failure of the welded area. The second part of the paper concerns a new experimental procedure for joint strength analysis in pure and mixed modes I/II and for joint model characterisation. Experiment is based on Arcan principle and results are compared to open literature. In the last part of the paper, the parameters of the new joint model are identified using experiments and used for several shapes of spot-welded specimens. The model predicts reasonably the elastic–plastic part of the response but is unable to predict the post-peak response observed especially in the case of pure shear.

International audience; This paper deals with a tunable bandpass filter topology which controls independently and simultaneously both the central frequency and bandwidth. This tunable filter results from the association of MEMS cantilevers, used as variable capacitors, with an original passive topology. The latter is based on dual behavior resonators (DBRs), each of them is constituted of low- and high-frequency open-ended stubs. The associated filter electrical response is characterized by tunable frequency transmission zeros. A millimeter bandpass filter with central frequency and relative bandwidth tunability of about 10 and 75%, respectively, is presented.; This paper deals with a tunable bandpass filter topology which controls independently and simultaneously both the central frequency and bandwidth. This tunable filter results from the association of MEMS cantilevers, used as variable capacitors, with an original passive topology. The latter is based on dual behavior resonators (DBRs), each of them is constituted of low- and high-frequency open-ended stubs. The associated filter electrical response is characterized by tunable frequency transmission zeros. A millimeter bandpass filter with central frequency and relative bandwidth tunability of about 10 and 75%, respectively, is presented.

The first part of this two-part paper presents an analytical model to predict the performances of double-row tapered roller bearings (DRTRB). The model has been structured in two major parts: (1)- A conventional quasi-static analysis to determine the internal load distribution, the bearing stiffness and the fatigue life and (2)- A quasi-dynamic analysis which integrates the differential equations for each bearing element in order to determine the amount of skidding, the friction forces and moments and consequently the heat dissipation. The proposed model allows one to take into account a general external loading (shaft tilting moments, radial and axial loads), the initial axial compression introduced while mounting, the operating speed and the lubricant properties. Some numerical results are presented in the second part of this two-part paper. Presented at the 56th Annual Meeting in Orlando, Florida May 20–24, 2001

International audience; In this paper we discuss about various modifications of classical coupled-lines narrow bandpass filter to obtain some frequency response improvement. The first modification concerns the broadening of the resonator strip-widths to improve their unloaded Q-factor. The second modification consists in replacing the in/out coupled lines section by tapped lines feeding. Finally a transmission zero is added using a geometrical modification that favor coupling between non-adjacent resonators. The theoretical investigation is carried out through a DOE based sensitivity study using both a circuit modeling approach and a full wave analysis. Theoretical and experimental results on microstrip filters are compared.; In this paper we discuss about various modifications of classical coupled-lines narrow bandpass filter to obtain some frequency response improvement. The first modification concerns the broadening of the resonator strip-widths to improve their unloaded Q-factor. The second modification consists in replacing the in/out coupled lines section by tapped lines feeding. Finally a transmission zero is added using a geometrical modification that favor coupling between non-adjacent resonators. The theoretical investigation is carried out through a DOE based sensitivity study using both a circuit modeling approach and a full wave analysis. Theoretical and experimental results on microstrip filters are compared.

International audience; An original implementation of a TX/RX transceiver for future UMTS base stations is proposed in this paper. Machined Foam substrates are stacked at first for implementing a square patch antenna on a composite thick support, then delivering interesting performances in terms of bandwidth and efficiency with respect to planar solutions. Active and passive devices are inserted within a shielded cavity created under the patch, then preventing from size constraints at such frequencies as well as insertion loss and parasitic radiations. A complete experimental procedure is presented for both TX and RX operating modes.; An original implementation of a TX/RX transceiver for future UMTS base stations is proposed in this paper. Machined Foam substrates are stacked at first for implementing a square patch antenna on a composite thick support, then delivering interesting performances in terms of bandwidth and efficiency with respect to planar solutions. Active and passive devices are inserted within a shielded cavity created under the patch, then preventing from size constraints at such frequencies as well as insertion loss and parasitic radiations. A complete experimental procedure is presented for both TX and RX operating modes.

International audience; This paper deals about the design and the implementation of a very compact microstrip Tx/Rx diplexer for future UMTS mobile terminals. Miniaturized loop-resonators filters have been developed and combined INTO data_ds.tmp_pub_a diplexer structure, satisfying different constraints such as a high electrical performance level (especially, a very narrow bandwidth, low insertion losses and a high out-of-band rejection), or also a great compactness and a compatibility with a standard planar integration.; This paper deals about the design and the implementation of a very compact microstrip Tx/Rx diplexer for future UMTS mobile terminals. Miniaturized loop-resonators filters have been developed and combined INTO data_ds.tmp_pub_a diplexer structure, satisfying different constraints such as a high electrical performance level (especially, a very narrow bandwidth, low insertion losses and a high out-of-band rejection), or also a great compactness and a compatibility with a standard planar integration.

International audience; In this paper, we discuss the control and suppression of spurious resonances commonly encountered with distributed bandpass filters. The basic idea consists of introducinglow-pass structures within bandpass topologies. By adjusting low-pass filter cutoff frequencies, harmonic resonances are attenuated, while maintaining in-band performances. In addition, transmission losses may be reduced as the insertion technique leads to optimum designs in terms of overall size. The approach described here is based upon the combination of classical synthesis techniques and optimization proceduresprovided by conventional computer-aided-design tools. Experimental results are obtained in the case of /spl lambda//sub g//4 shunt-stub filters implemented in classical semilumped low-pass architectures. Then, we investigate alternative integration technologies and techniques to improve the out-of-band rejection over very wide operating bandwidth. To overcome some design limitations, i.e., workable characteristicimpedance value, we propose and validate a multilayer solution. Finally, new low-pass topologies are suggested to improve low-pass filter band rejection.; In this paper, we discuss the control and suppression of spurious resonances commonly encountered with distributed bandpass filters. The basic idea consists of introducinglow-pass structures within bandpass topologies. By adjusting low-pass filter cutoff frequencies, harmonic resonances are attenuated, while maintaining in-band performances. In addition, transmission losses may be reduced as the insertion technique leads to optimum designs in terms of overall size. The approach described here is based upon the combination of classical synthesis techniques and optimization proceduresprovided by conventional computer-aided-design tools. Experimental results are obtained in the case of /spl lambda//sub g//4 shunt-stub filters implemented in classical semilumped low-pass architectures. Then, we investigate alternative integration technologies and techniques to improve the out-of-band rejection over very wide operating bandwidth. To overcome some design limitations, i.e., workable characteristicimpedance value, we propose and validate a multilayer solution. Finally, new low-pass topologies are suggested to improve low-pass filter band rejection.

International audience; This paper deals with linking system-level design tools with existing hardware design and synthesis tools. The main difficulty is the gap that exists between concepts handled at the system level and concepts accepted by existing synthesis tools. The paper gives an overview of the state of the art and presents COSMOS, a design methodology intended to fill this gap. The methodology allows the combination of a system-level design language (SDL) and a hardware design language (VHDL). The use of such a system-level specification can dramatically reduce the volume of information handled.

International audience; Heimat, in the first volume of Berthold Auerbach’s Black Forest Village Stories (1843) is rather more globalised than its traditional anchorage in the local would have us believe: the mutations of modernity have reached the village and Heimat is born of the fear of its soon-to-be disappearance. What then emerges is a wandering Heimat, a nomad Heimat, one that is delocalised or even re-localisable. This paper focuses on the mutations of the experience of Heimat through two village histories and two characters: Tolpatsch who emigrates and recreates his Swabian village overseas, discovering his German identity from abroad, at the same time as his American identity ; and Ivo, the author’s autobiographical double, who chooses the next-door village, a sign, perhaps, of an impossible Heimkehr, but also of a reinvention of Heimat, and of the self, through experiencing distance.; La Heimat, dans le premier volume des Histoires villageoises de la Forêt-Noire (1843), est bien plus globalisée que ne le laisserait penser son traditionnel ancrage dans le local : les mutations de la modernité ont bel et bien atteint le village. La Heimat naît donc de la crainte de sa prochaine disparition. Mais c’est une Heimat délocalisée, en errance, que l’on quitte et où l’on désire revenir. Peut-on aller jusqu’à parler d’une relocalisation ? Auerbach semble suggérer deux réponses, à travers le parcours de deux personnages : Tolpatsch, qui émigre et réimplante son village souabe outre-mer, découvrant là-bas sa germanité tout en devenant progressivement américain ; et Ivo, double autobiographique de l’auteur, qui choisit le village d’à côté, signe, peut-être, d’une impossible Heimkehr, mais d’une réinvention de la Heimat, et donc de soi, par l’expérience de l’écart.