EVALUATING THE PREDICTED RELIABILITY OF MECHATRONIC SYSTEMS: STATE OF THE ART

Reliability analysis of mechatronic systems is one of the most young field and dynamic branches of research. It is addressed whenever we want reliable, available, and safe systems. The studies of reliability must be conducted earlier during the design phase, in order to reduce costs and the number of prototypes required in the validation of the system. The process of reliability is then deployed throughout the full cycle of development; this process is broken down into three major phases: the predictive reliability, the experimental reliability and operational reliability. The main objective of this article is a kind of portrayal of the various studies enabling a noteworthy mastery of the predictive reliability. The weak points are highlighted, in addition presenting an overview of all approaches existing in quantitative and qualitative modeling and evaluating the reliability prediction is so important for the futures reliability studies, and for academic researches to innovate other new methods and tools. the Mechatronic system is a hybrid system; it is dynamic, reconfigurable, and interactive. The modeling carried out of reliability prediction must take into account these criteria. Several methodologies have been developed in this track of research. In this article, we will try to handle them from a critical angle

Evaluating the predicted reliability of mechatronic systems: state of the art

Reliability analysis of mechatronic systems is a recent field and a dynamic branch of research. It is addressed whenever there is a need for reliable, available, and safe systems. The studies of reliability must be conducted earlier during the design phase, in order to reduce costs and the number of prototypes required in the validation of the system. The process of reliability is then deployed throughout the full cycle of development. This process is broken down into three major phases: the predictive reliability, the experimental reliability and operational reliability. The main objective of this article is a kind of portrayal of the various studies enabling a noteworthy mastery of the predictive reliability. The weak points are highlighted. Presenting an overview of all the quantitative and qualitative approaches concerned with modelling and evaluating the prediction of reliability is so important for future reliability studies and for academic research to come up with new methods and tools. The mechatronic system is a hybrid system, it is dynamic, reconfigurable, and interactive. The modeling carried out of reliability prediction must take into account these criteria. Several methodologies have been developed in this track of research. In this regard, the aforementioned methodologies will be analytically sketched in this paper.Comment: 13 page, Mechanical Engineering: An International Journal (MEIJ), Vol. 3, No. 2, May 201

Schmallenberg virus detection in Culicoides biting midges in Spain: First laboratory evidence for highly efficient infection of Culicoides of the Obsoletus complex and Culicoides imicola

Since Schmallenberg disease was discovered in 2011, the disease rapidly spread across Europe. Culicoides biting midges have been implicated as putative Schmallenberg vectors in Europe. The detection of Schmallenberg virus (SBV) in field collected Culicoides was evaluated through retrospective (2011–2012) collections and captures performed in 2013. This study represents the first detection of SBV in field collected Culicoides in Spain. Infectious midges were detected at the foothills of Pyrenees, Aramunt, in the summer 2012. All the specimens infected with Schmallenberg were of the species Culicoides obsoletus s.s. confirming its putative vector status in Spain. Experimental infection on field collected Culicoides provided evidence of atypical high efficiency for SBV vector infection and transmission potential in local populations of Culicoides imicola and in Culicoides of the Obsoletus complex. However, captured individuals of C. imicola were more susceptible to SBV infection than C. obsoletus s.l. (p < .001), with an infection ratio of 0.94 and 0.63, respectively. In contrast, a Culicoides nubeculosus colony appeared to be refractory to SBV infection.info:eu-repo/semantics/acceptedVersio

Photo-catalytic activity of BiVO4 thin film electrodes for solar-driven water splitting

There is an ever-increasing attention directed to the development of solar fuels by photo-electrochemical water splitting, given the inexhaustible availability of solar energy. The water oxidation half-reaction is a critical step for the overall water splitting reaction, and the development of suitable photoanodes is therefore required. The present research work focuses on bismuth vanadate thin films’ deposition on FTO glass electrodes, through the dip coating technique, and discusses the influence of the film preparation technique on the electrode's photo-electrochemical performance. The bismuth vanadate thin films were synthesized with thicknesses ranging from 60 to 210 nm, depending on a number of dip coatings from 2 to 15. The structural and optical characterization of the films showed that monoclinic scheelite-type phase was obtained in all samples, with crystal sizes ranging from 24 to 65 nm, at increasing film thicknesses, and corresponding band gaps between 2.55 and 2.35 eV. A maximum photo-current density of about 0.57 mA cm−2 at 1.23 V vs. RHE under sunlight illumination was obtained for an electrode thickness of 160 nm. The electrochemical impedance spectroscopy elucidated the transport mechanisms occurring at the electrolyte–electrode interface, as well as inside the film. The estimation of the equivalent circuit parameters showed that an increasing film thickness decreased the resistance associated to the charge transfer between the electrolyte and the electrode (from 1100 to 450 Ω, from 60 to 160 nm layer thickness, respectively), given the higher number of active sites involved in the reaction. However, excessive film thicknesses increase the probability of charge recombination within the film and, in the specific case here investigated, can also be associated to film imperfections arising from several deposition-calcination cycles, which further act as traps. These concurring phenomena are of high relevance to isolate the rate-determining step of the water oxidation half-reaction, in the perspective of an optimization of bismuth vanadate film coating on FTO to obtain photo anodes

Catalytic Oxidation of Soot and Volatile Organic Compounds over Cu and Fe Doped Manganese Oxides Prepared via Sol-Gel Synthesis

A set of manganese oxide catalysts was synthesized and doped with Cu and/or Fe by means of the citric acid sol-gel preparation method. The samples were studied by means of several characterization techniques: field-emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), N2-physisorption at -196 °C, H2 and soot temperature-programmed reduction (H2-TPR, soot-TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic performance of the prepared catalysts was investigated in the oxidation of a probe VOC molecule (propylene) and carbon soot singularly and simultaneously. The catalytic performances were studied as well assuring a content of 5 vol.% of water in the gaseous reactive mix. The investigations evidenced that the best soot catalytic oxidation rates occurred over the Mn2O3 sample, while the copper-doped manganese oxide (i.e. the MnCu15) showed the best performance in the decomposition of propylene. The soot conversion rates of the samples were positively correlated to the Mn3+/Mn2+ ratio of the samples, while the activity in the oxidation of propylene could be attributed to the reducibility enhancement caused by the insertion of Cu species in the structure of Mn2O3. The most active samples in soot oxidation demonstrated only a slight catalytic activity deactivation after thermal aging and practically no deactivation during the tests with humidity. Interestingly, the simultaneous soot-propylene oxidation tests evidenced an enhancement of the oxidation of soot particles in "tight"contact with the catalyst, likely due to a cooperative effect between soot and propylene oxidation

Catalytic Abatement of Volatile Organic Compounds and Soot over Manganese Oxide Catalysts

A set of manganese oxide catalysts was synthesized via two preparation techniques: solution combustion synthesis (Mn3O4/Mn2O3-SCS and Mn2O3-SCS) and sol-gel synthesis (Mn2O3-SG550 and Mn2O3-SG650). The physicochemical properties of the catalysts were studied by means of N2-physisorption at −196◦ C, X-ray powder diffraction, H2 temperature-programmed reduction (H2-TPR), soot-TPR, X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM). The high catalytic performance of the catalysts was verified in the oxidation of Volatile Organic Compounds (VOC) probe molecules (ethene and propene) and carbon soot in a temperature-programmed oxidation setup. The best catalytic performances in soot abatement were observed for the Mn2O3-SG550 and the Mn3O4/Mn2O3-SCS catalysts. The catalytic activity in VOC total oxidation was effectively correlated to the enhanced low-temperature reducibility of the catalysts and the abundant surface Oα-species. Likewise, low-temperature oxidation of soot in tight contact occurred over the Mn2O3-SG550 catalyst and was attributed to high amounts of surface Oα-species and better surface reducibility. For the soot oxidation in loose contact, the improved catalytic performance of the Mn3O4/Mn2O3-SCS catalyst was attributed to the beneficial effects of both the morphological structure that—like a filter—enhanced the capture of soot particles and to a probable high amount of surface acid-sites, which is characteristic of Mn3O4 catalysts

Evolution de la dynamique hydrosédimentaire des étangs de moyenne montagne sous la double influence urbaine et agricole : cas de l’étang de Haute-Jarrie (Isère : France)

L’évolution rapide de la dynamique urbaine dans les secteurs montagneux a certes été bénéfique pour l’homme mais néfaste pour les écosystèmes et leur biodiversité. Véritables espaces de récréation et de loisirs, les étangs ont progressivement acquis le label de lieux de découvertes et de sensibilisation à l’environnement. Face à la pression démographique enregistrée sur les trente dernières années dans les principales vallées alpines et l’extension urbaine engendrée, des menaces sérieuses de dégradation, voire de disparition de ces entités environnementales ont été enregistrées. Les lacs, les étangs et les mares subissent pleinement les contrecoups de cette dynamique ; ils voient leurs espaces se réduire progressivement et se détacher de leur continuum hydrologique suite à des modifications aigues à caractère anthropique (perturbation du réseau hydrographique, pompages directs dans les aquifères sous-jacents, pratiques agricoles inadaptées,…). Face à ce constat, des actions de protection et de préservation ont été lancées en réponse à des attentes locales et surtout sous l’impulsion des différentes lois et directives qui se sont succédé sur les trente dernières années (loi sur l’eau du 03 janvier. 1992, LEMA : Loi sur l’Eau et les Milieux Aquatiques, 2006, DCE : Directive Cadre sur l’Eau,…). L’étang de Jarrie en Isère est un exemple concret et le témoin direct de cette dynamique urbaine et son impact sur l’environnement. La réduction des espaces agricoles sur le plateau de Haute-Jarrie et l’occupation des secteurs humides proches du plan d’eau favorisent l’érosion et modifient considérablement les caractéristiques des sols et plus largement la dynamique hydrosédimentaire (Robert, 1996). Les épisodes pluvieux à forte intensité contribuent activement au détachement des particules fines (< 7µm) des terres agricoles voisines et leur transfert soit par écoulement concentré le long des sillons (labour) soit par écoulement diffus (en nappe) vers le plan d’eau. Celui-ci a perdu près des 2/3 de son volume en eau durant les deux dernières décennies. Face à ce phénomène, des actions de remédiation (curage, fossés de décantation) ont été entreprises pour réduire le volume des dépôts solides et augmenter les réserves hydriques. L’étude que nous avons réalisée avait un double objectif : 1) quantifier le ruissellement et les volumes sédimentaires associés et la mesure des effets des activités anthropiques sur la dynamique hydrosédimentaire du bassin versant, 2) puis proposer des solutions rapides pour atténuer ce déséquilibre par la création de canaux de décantation et l’élargissement des fossés naturels susceptibles de piéger une partie des flux sédimentaires.The rapid developmentof urban inmountainous areashas certainly beenbeneficialto humansbut harmful toecosystems andtheir biodiversity. The recreation areas and ponds have becomeplaces ofdiscovery andenvironmental awareness over time. Faced withdemographic pressurerecordedover the past thirtyyears in the mainAlpine valleysand gradual urban disappearance, the threat of degradationor evendisappearance oftheenvironmental entitieshassignificantly increased. Lakes and ponds are affected by these dynamic changes, which reduce their surface areasand detach them from theirhydrologiccontinuum, thus lead to theirextinction. Given this situation, protection initiativeshave been launchedin response tolocalneeds, in particularly under the effects of various lawsanddirectives (Water law of03January 1992, LEMA : Loi sur l’Eau et les Milieux Aquatiques, 2006, DCE : Directive Cadre sur l’Eau). PondJarrie (Isère, France)is a typical example of theurban dynamicsand its impact onthe environment. The reductionof farmlandon the plateau ofHaute-Jarrie as well as the wetlands occupationnear the water bodiescause an erosionandsignificant change in the characteristics of thesoiland more widely the hydro-sedimentary dynamic. The intensive rainstorms actively contribute to the detachment of fine particles of neighboring farmland and the transfer of fine sediment (<7μm) into the water. It has been lost almost two thirds of its water volume during the last two decades. Faced with this phenomenon, remedial actions (cleaning) have been taken in order to reduce the volume of solid deposits and increase the water reserves. This study has focused on two objectives: Firstly, the quantification of the componentsof the water balanceand measuring the effectsof human activities onthehydro-sedimentary dynamicsof the watershed. Secondly, we offer quicksolutionsto reducethis imbalancebycreating a settling channelsand an expansion ofnaturalditchesto reducesediment flows.Die schnelle Entwicklung der Bebauung in den Gebirgsregionen ist sicherlich für den Menschen positiv gewesen, aber verheerend für die Ökosysteme und ihre Artenvielfalt. Als richtiggehende Erholungs- und Freizeitgebiete sind Weiher nach und nach Ein Inbegriff für Entdeckungen und Umweltbewusstsein geworden. Angesichts des demographischen Drucks, den man in den letzten dreißig Jahren in den größeren Alpentälern beobachten konnte, und der damit einhergehenden Zersiedelung zeigt sich, dass die Qualität dieser Umwelteinheiten ernsthaft bedroht ist beziehungsweise sie sogar verschwinden. Die Seen, Teiche und Weiher sind den negativen Auswirkungen dieser Dynamik ausgesetzt ; ihr Gebiet wird zunehmend reduziert und auf Grund von akuten menschlichen Eingriffen (Störungen der Flusssysteme, direktes Pumpen aus den Grundwasserleitern, unangepasste landwirtschaftliche Praktiken) aus dem hydrologischen Kontinuum gelöst. Dieser Beobachtung stehen Maßnahmen zu Schutz und Erhaltung gegenüber, die auf lokale Initiativen zurückgehen oder aus den verschiedenen Gesetzen und Richtlinien resultieren, die in den letzten dreißig Jahren erlassen wurden (wie die französischen Wassergesetze vom 3. Januar 1992 und von 2006 (LEMA) und die Europäische Wasserrahmenrichtlinie von 2000). Der Weiher von Jarrie im Département Isère ist ein konkretes Beispiel und ein direkter Zeuge dieser Bebauungsdynamik und ihrer Auswirkung auf die Umwelt. Die Reduzierung der landwirtschaftlich genutzten Flächen auf der Hochebene von Haute-Jarrie und die Besiedelung von Feuchtgebieten nahe des Weihers begünstigen die Erosion und verändern erheblich die Bodeneigenschaften und in weiterem Sinne die Wassersedimentierung (Robert, 1996). Intensive Niederschläge tragen aktiv zur Ablösung feiner Partikel (< 7µm) der benachbarten landwirtschaftlichen Flächen sowie zu ihrer Verlagerung bei, die entweder durch konzentrierten Abfluss entlang der Ackerfurchen oder durch diffusen Abfluss (über das Grundwasser) bis zum stehenden Gewässer erfolgt. Dieses hat in den letzten zwei Jahrzehnten zwei Drittel seines Volumens verloren. Angesichts dieses Phänomens wurden verschiedene Maßnahmen ergriffen (Ausbaggern, Sedimentierungsgräben), um das Volumen der Sedimente zu reduzieren und die Wasserreserve zu vergrößern. Die von uns realisierte Studie hatte ein doppeltes Ziel : 1. den Abfluss und das damit einhergehende Sedimentvolumen zu messen und damit auch die Auswirkungen der menschlichen Eingriffe auf die Wassersedimentierungsdynamik des Niederschlagsgebiets, und daran anschließend 2. schnelle Lösungen vorzuschlagen, um dieses Ungleichgewicht durch die Einrichtung von Dekantierungskanälen und die Verbreiterung von natürlichen Gräben, die einen Teil des Sedimentierungsflusses abfangen können, abzuschwächen

Contribution à la dépollution d’un rejet textile par adsorption sur un coagulant à base du mélange fer/aluminium préparé par électrocoagulation

L&#8217;industrie textile consomme une grande quantit&#233; d&#8217;eau, g&#233;n&#233;rant ainsi des rejets liquides &#224; charge &#233;lev&#233;e en divers types de polluants. Ces derniers produisent des effets nocifs sur l&#8217;environnement. Ce travail s&#8217;int&#233;resse &#224; la d&#233;pollution d&#8217;un rejet d&#8217;une industrie textile, par addition d&#8217;un coagulant synth&#233;tique &#224; base de fer et d&#8217;aluminium, pr&#233;par&#233; par le proc&#233;d&#233; d&#8217;&#233;lectrocoagulation. Les r&#233;sultats ont montr&#233; que le traitement de ce rejet par ce coagulant, a permis d&#8217;atteindre un rendement d&#8217;&#233;limination des mati&#232;res colorantes de 83.37% en terme de demande chimique en oxyg&#232;ne (DCO).Mots cl&#233;s: traitement, hydroxyde, coagulation, demande chimique en oxyg&#232;n

In situ Raman analyses of the soot oxidation reaction over nanostructured ceria-based catalysts

Abstract To reduce the emissions of internal combustion engines, ceria-based catalysts have been widely investigated as possible alternatives to the more expensive noble metals. In the present work, a set of four different ceria-based materials was prepared via hydrothermal synthesis, studying the effect of Cu and Mn as dopants both in binary and ternary oxides. In situ Raman analyses were carried out to monitor the behaviour of defect sites throughout thermal cycles and during the soot oxidation reaction. Despite ceria doped with 5% of Cu featured the highest specific surface area, reducibility and amount of intrinsic and extrinsic defects, a poor soot oxidation activity was observed through the standard activity tests. This result was confirmed by the calculation of soot conversion curves obtained through a newly proposed procedure, starting from the Raman spectra collected during the in situ tests. Moreover, Raman analyses highlighted that new defectiveness was produced on the Cu-doped catalyst at high temperature, especially after soot conversion, while a slight increase of the defect band and a total reversibility were observed in case of the ternary oxide and pure/Mn-doped ceria, respectively. The major increment was related to the extrinsic defects component; tests carried out in different atmospheres suggested the assignment of this feature to vacancy-free sites containing oxidized doping cations. Its increase at the end of the tests can be an evidence of peroxides and superoxides deactivation on catalysts presenting excessive oxygen vacancy concentrations. Instead, ceria doped with 5% of Mn exhibited the best soot oxidation activity, thanks to an intermediate density of oxygen vacancies and to its well-defined morphology