IRT Jules Verne

The concept of reconfigurable manufacturing systems (RMSs) is a current subject that has attracted intensive research. This latter covers the entire RMS life cycle, from the design to the exploitation phase, and includes several important problems requiring the use of optimisation. The objective of this paper is to survey research publications related to RMS optimisation problems and their solution methods. For this, the types of RMS and their components are described. Subsequently, relevant objective functions and performance indicators of RMS are presented. In addition, an overview of the most used solution approaches and a classification of optimisation problems are proposed. Finally, a detailed analysis, our conclusions, and suggestions for future research are provided.

Electrokinetic mobility was measured on calcite particles dispersed in aqueous solutions as a function of pH, ion concentration and type (Na+, Ca2+, CI-, S04 2-). Whatever the pH value, experimental results show a good correlation between electrokinetic potential and Ca2+ activity. Considering Ca2+ as a potential determining ion and using a simple complexation model at the surface, we show that the displacement of the isoelectric point can be attributed to the relative affinity of CO3 2- and Ca2+ for the surface.

Additive manufacturing is becoming more and more important today by offering very advantageous opportunities. It gives the ability to manufacture parts with complex geometry, without the need of specific tools. This work focuses on fused filament fabrication process. It consists in melting the polymer, and extruding it through a nozzle to create a structure defined by a toolpath. The extruded filament solidifies while cooling. One of the major drawbacks of this process is the poor mechanical properties of the parts compared to thermoplastic injection. This is related to (i) the porosities between deposited filaments and (ii) the limited adhesion between deposited layers. This adhesion phenomenon is thermally driven by the molecular mobility of the polymer chains. The objective of this work is to understand, model and quantify heat exchanges in the process, in order to define the process window leading to optimal mechanical resistance of the parts. With this aim, a laboratory-scale instrumented 3D printing machine has been designed and manufactured. This bench is thermally controlled. Polymer and environment temperatures can be measured with an infrared camera, pyrometer and thermocouples instrumentation. In parallel, a numerical model has been developed to predict the influence of the process parameters on the cooling and adhesion. For this purpose, thermal properties have been characterized. A sensitivity analysis quantifies the most relevant properties to measure and control accurately and a comparison between numerical and experimental results validates the approach.

Age determination is a major field of interest in forensic anthropology. Among the different methods based on macroscopic skeletal study, the Suchey-Brooks method, which analyzes the pubic symphysis, is one of the most reliable. We applied the Suchey-Brooks method to three-dimensional computed tomographic reconstructions of the pubic symphysis. We demonstrated excellent agreement between the results of analysis of bone samples and those of the three-dimensional images, in particular regarding ridges of the articular surface and delimitation of the extremities. The accuracy of age estimation did not significantly differ (Wilcoxon test) between the Suchey-Brooks method applied to bones and the same method applied to CT images. Using high-quality images, this approach seems as reliable as the standard Suchey-Brooks method and offers several advantages: no bone preparation, no damage to bone material, and the possibility of application to living individuals.

Together with proteins and fats, carbohydrates are one of the macronutrients in the human diet. Digestible carbohydrates, such as starch, starch-based products, sucrose, lactose, glucose and some sugar alcohols and unusual (and fairly rare) α-linked glucans, directly provide us with energy while other carbohydrates including high molecular weight polysaccharides, mainly from plant cell walls, provide us with dietary fibre. Carbohydrates which are efficiently digested in the small intestine are not available in appreciable quantities to act as substrates for gut bacteria. Some oligo- and polysaccharides, many of which are also dietary fibres, are resistant to digestion in the small intestines and enter the colon where they provide substrates for the complex bacterial ecosystem that resides there. This review will focus on these non-digestible carbohydrates (NDC) and examine their impact on the gut microbiota and their physiological impact. Of particular focus will be the potential of non-digestible carbohydrates to act as prebiotics, but the review will also evaluate direct effects of NDC on human cells and systems.

Studying the atmospheric corrosion of copper alloy artifacts is important to acquire a better knowledge about the condition of the object and its possible conservation and restoration. The nature of the formed product, e.g. sulfate, carbonate or chloride, depends on factors such as the amount of polluting elements or humidity but may also depend on the nature of the underlying aesthetic patina, applied by the artist. The composition of the patination solution and the method of patination will both influence the nature of this aesthetic patina, i.e. its chemical composition and morphology. However, although a lot of patination recipes exist, little is known about these patinas as far as composition, structure and ageing is concerned. Therefore, a combination of several surface analytical techniques is required for the complete characterization of patina layers. In this paper, Raman spectroscopy is used to study the characteristics of several patinas obtained on copper following different traditional recipes.

Abstract Cable-driven parallel robots (CDPRs) hold numerous advantages over conventional parallel robots in terms of high speed and large workspace. Cable-driven parallel robots whose workspace can be further increased by the modification of their geometric architecture are known as reconfigurable cable-driven parallel robots. A novel concept of reconfigurable cable-driven parallel robots that consists of a classical cable-driven parallel robot mounted on multiple mobile bases is known as mobile CDPR. This paper proposes a methodology to trace the wrench-feasible workspace of mobile cable-driven parallel robots by determining its available wrench set. Contrary to classical cable-driven parallel robots, we show that the available wrench set of a mobile cable-driven parallel robot depends, not only on the cable tension limits but also on the static equilibrium conditions of the mobile bases. The available wrench set is constructed by two different approaches known as convex hull approach and hyperplane shifting method. Three case studies are carried out for the validation of the proposed methodology. The proposed approach is experimentally validated on a mobile cable-driven parallel robot with a point-mass end-effector and two mobile bases.

The expression of different glucose transporter isoforms was measured during the development and differentiation of the rat mammary gland. Before conception, when the mammary gland is mainly composed of adipocytes, Glut 4 and Glut 1 mRNAs and proteins were present. During pregnancy, the expression of Glut 4 decreased progressively, whereas that of Glut 1 increased. In the lactating mammary gland only Glut 1 was present, and was expressed at a high level. The absence of Glut 4 suggests that glucose transport is not regulated by insulin in the lactating rat mammary gland.

Purpose The installation of industrial robots requires security barriers, a costly, time-consuming exercise. Collaborative robots may offer a solution; however, these systems only comply with safety standards if operating at reduced speeds. The purpose of this paper is to describe the development and implementation of a novel security system that allows human–robot coexistence while permitting the robot to execute much of its task at nominal speed. Design/methodology/approach The security system is defined by three modes: a nominal mode, a coexistence mode and a gravity compensation mode. Mode transition is triggered by three lasers, two of which are mechanically linked to the robot. These scanners create a dynamic envelope around the robot and allow the detection of operator presence or environmental changes. To avoid velocity discontinuities between transitions, the authors propose a novel time scaling method. Findings The paper describes the system’s mechanical, software and control architecture. The system is demonstrated experimentally on a collaborative robot and is compared with the performance of a state-of-art security system. Both a qualitative and quantitative analysis of the new system is carried out. Practical implications The mode transition method is easily implemented, requires little computing power and leaves the trajectories unchanged. As velocity discontinuities are avoided, motor wear is reduced. The execution time is substantially less than a commercial alternative. These advantages can lead to economic benefits in high-volume manufacturing environments. Originality/value This paper proposes a novel system that is based on industrial material but can generate dynamic safety zones for a collaborative robot.

In cable-driven parallel robots (CDPRs), rigid links are substituted by flexible cables. This change in actuation allows for a large workspace with a high payload to weight ratio, among other appealing characteristics. However, the accuracy for such systems needs to be improved to truly outperform classical parallel robots. A possible and not yet well studied solution is the use of vision-based control for CDPRs. This letter deals with the stability analysis of such a control scheme with regard to uncertainties lying both in the analytical models and the experimental setup. Two CDPRs are analyzed as illustrative examples. The results obtained show the system's robustness with respect to uncertainties.

Purpose. The aim of this systematic review is to assess whether the anatomy of mental foramen is precisely evaluable with cone beam computed tomography (CBCT) before implantation in humans. Methods. A systematic review was carried out to evaluate the anatomy of mental foramen (size, position, symmetry, anterior loop, and accessory mental foramen or multiple mental foramina). According to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, an electronic search of three databases (Medline, Web of Science, and Cochrane Library) was undertaken until June 2020 and was supplemented by manual searching. Two reviewers will independently perform the processes of study inclusion, data extraction, and quality assessment. Systematic reviews, studies about children, and case reports were excluded. Only studies using CBCT to do preoperative evaluation were selected. Results. From 728 potentially eligible articles, 72 were included in the qualitative analysis and quantitative synthesis. This systematic review provided an assessment of the anatomy of the mental foramen. The mental foramen was located mostly between the two premolars (between 50.4% and 61.95%) or apically to the second premolar (from 50.3% to 57.9%). The mean diameter of the mental foramen was bigger in males than in females; the difference between them could reach 0.62 mm. The anterior loop seemed to be longer in males (between 0.87 ± 1.81 and 7.25 ± 2.02 mm) than in females (between 0.81 ± 1.18 and 6.52 ± 1.63 mm) and with the presence of teeth (from 0.91 ± 1.18 to 2.55 ± 1.28 for dentate people and from 0.25 ± 0.61 to 2.40 ± 0.88 mm for edentate population). The anterior loop and the accessory mental foramina were detected more frequently with CBCT than panoramic X-ray: only between 0.0 and 48.6% AMFs detected with CBCT were also seen with panoramic images. Clinical Significance. The mental foramen (MF) is an important landmark for local anesthesia and surgical and implantology procedures. Its location, morphology, and anatomical variations need to be considered to avoid mental nerve injury. The aim of this review is to evaluate the mental foramen using CBCT through a systematic literature review to improve knowledge of this complex area for the clinician.

Abstract In Germany more than 20% of the energy mix is made up of renewable energy and its share is rapidly increasing. The federal government expects renewables to account for 35% of Germany's electricity consumption by 2020, 50% by 2030 and 80% by 2050. According to the German Energy Agency, multi-billion euro investments in energy storage are expected by 2020 in order to reach these goals. The growth of this fluctuating energy supply has created demand for innovative storage options in Germany and it is accelerating the development of technologies in this field. Along with batteries and smart grids, hydrogen is expected to be one of the lead technologies. 2010 a commercialization roadmap for wind hydrogen was set up by the two northern federal states of Hamburg and Schleswig-Holstein with the goal of utilizing surplus wind power for the electrolytic production of hydrogen. With the creation of the “performing energy initiative”, 2011, Brandenburg and Lower Saxony joined this undertaking. The aim of this initiative is to set up demonstration projects in order to develop and optimize wind-hydrogen hybrid systems and prepare their commercialization for the time after 2020. Beside the conversion of hydrogen into electricity and fuel for cars, further markets like raw material for the chemical, petrochemical, metallurgy and food industry are going to be addressed. Considering the fact there are over 40 caves currently used for natural gas storage with a total volume of 23.5 billion cubic meters and 400 000 km gas grid available in Germany, the German Technical and Scientific Association for Gas and Water sees opportunities for hydrogen to be fed into the existing natural gas grid network. The name of this concept is power-to-gas. According to the current DVGW-Standards natural gas in Germany can contain up to 5% hydrogen. The GERG, European Group on the Gas Research sees potential to increase this amount up to 6% to 20%. Power-to-gas could serve both for fuel and for the storage of extra energy produced by renewable sources. The hydrogen produced via electrolysis could be drawn upon – directly or as synthetic natural gas (SNG) in a second additional methanation process step – to provide electricity by means of CCGT (combined cycle gas turbines) or CHP (combined heat and power) using for example fuel cells. It could also address the industrial and household heat market. DVGW is furthermore participating in the “Power-to-Gas Platform” that was set up in 2012 by the German Energy Agency, bringing together RnD institutes, renewable energy project developers and park operators, utilities, underground storage providers in order to create political support for this new technology. Demonstration projects will be completed by 2020 in order to develop business models (for storage, production and trade of “green gas”) and devices (electrolysers, turbines, smart gas metering, compressors, storage capacities amongst others) to enable the implementation of this concept on a broad scale. This means that a multitude of industrial players will be involved in the changes that will occur in the value chain: utilities (electricity, gas), power technology companies, car makers, heating device manufacturers, but also manufacturers of measurement, regulation and control devices, suppliers of the biogas and methanation industry. Germany is the pioneer in this field. This technology however increasingly interests its neighbours, with project developments in France, Italy, Spain, and UK but also in North America and North Africa. Germany can contribute its valuable experience (e.g. legal framework for power-to-gas) to the development of these industries. German participants in demonstration projects in these countries could for example be renewable energy park operators, RnD institutes and suppliers.

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Fatty acids are the preferred oxidative substrates of the heart, skeletal muscles, kidney cortex and liver in adult mammals. They are supplied to these tissues either as nonesterified fatty acids (NEFA), or as triglycerides after hydrolysis by lipoprotein lipase. During fetal life, tissue capacity to oxidize NEFA is very low, even in species in which the placental transfer of NEFA and carnitine is high. At birth, the ability to oxidize NEFA from endogenous sources or from milk (a high-fat diet) develops rapidly in various tissues and remains very high throughout the suckling period. Ketogenesis appears in the liver by 6 to 12 hrs after birth, and the ketone bodies are used as oxidative fuels by various tissues during the suckling period. At the time of weaning, the transition from a high-fat to a high-carbohydrate diet is attended by a progressive decrease in the ketogenic capacity of the liver, whereas other tissues (skeletal muscle, heart, kidney) maintain a high capacity for NEFA oxidation. The nutritional and hormonal factors involved in changes in fatty acid oxidation during development are discussed.

This paper deals with Reconfigurable Cable-Driven Parallel Robots (RCDPRs). A RCDPR is able to change the locations of its cable exit points, the latter being defined as the connection points between the cables and the robot base frame. Given a RCDPR, a set of possible reconfigurations, a desired platform path and a description of the robot environment, the reconfiguration strategy proposed in this paper selects the optimal configurations to be associated to each point of the desired path. The selection of the optimal configurations can be performed with respect to several criteria such as the number of configuration changes, the number of cable reconfigurations and the robot stiffness. In this paper, the optimization is performed using a Dijkstra's based algorithm.

Recent tsunami and hurricane-caused destruction, and the possibility of both tsunami inundation and storms of even greater magnitude and frequency making landfall in the future, has focused attention on the vulnerability of coastal structures, and bridges in particular. Findings from a series of experiments measuring forces on a 1:35 scale bridge model impacted by a solitary wave with varying percentages of air relief openings (AROs) between girders are presented here. A range of water depths, wave amplitudes, and elevations of the model above the still-water level (SWL) are considered. Results show significant reduction of vertical uplift forces when AROs are added to the bridge model, particularly when the girders are fully elevated above the SWL or only slightly submerged, but relatively little effect on horizontal forces in the direction of wave propagation is observed. Buoyancy calculations show added hydrostatic force does not alone contribute to uplift forces, but rather a combination of hydrostatic force, wave impact force, and deformation of the wave must all be considered.

This paper describes a digital holographic setup based on in-line holography and a high-speed recording to get a multipoint vibrometer. The use of a high-speed sensor leads to specificities that enable the in-line configuration to be used. The case of transient vibrations is investigated through a full simulation of the holographic process. The simulation shows that the first instants are critical since distortion may occur, resulting in errors in the phase measurement. Experimental results are provided by exciting an aluminum beam with a transient signal. A comparison with the velocity measured by a pointwise vibrometer is provided. Frequency response functions are extracted and the experimental results confirm the ability of the method to provide full-field contactless measurements at the high-speed time scale evolution of the vibration.

this paper discusses on the influence of decorrelation noise induced by quantization and shot-noise when recording digital holograms at very high frame rate. A criterion based on the coherence factor of the hologram phase difference is proposed. The main parameters of interest are the ratio between the reference and the object waves and the sensor dynamics, depending on the photo-electron capacity of pixels. The study is based on a full numerical simulation of the holographic process, which provides useful rules. This leads to define the optimal conditions for recording at very-high frame rate with minimization of the decorrelation noise. Experimental results obtained with frame rate at 50kHz confirm the proposed approach.

According to recent results, Reconfigurable Manufacturing Systems or RMSs are the most efficient for manufacturing companies to adapt to the current market. This market is characterized by a high competitive level and very frequent and sudden variations in customer demands. Developing an RMS is not an easy task and a lot of work has been done in both academic and industrial fields to give solutions to address this issue. We can, for example, apply different methods and techniques used in the design of complex systems to design an RMS, these methods should be studied, analyzed, modified and improved if necessary before to be applied. Modularity is one of these techniques. In this paper, we will discuss how modularity could be used to develop RMS, and we will propose a standard approach based on the Design Structure Matrix to design an RMS with a modular architecture.

The fiber optic sensors (FOSs) are commonly used for large-scale structure monitoring systems for their small size, noise free and low electrical risk characteristics. Embedded fiber optic sensors (FOSs) lead to micro-damage in composite structures. This damage generation threshold is based on the coating material of the FOSs and their diameter. In addition, embedded FOSs are aligned parallel to reinforcement fibers to avoid micro-damage creation. This linear positioning of distributed FOS fails to provide all strain parameters. We suggest novel sinusoidal sensor positioning to overcome this issue. This method tends to provide multi-parameter strains in a large surface area. The effectiveness of sinusoidal FOS positioning over linear FOS positioning is studied under both numerical and experimental methods. This study proves the advantages of the sinusoidal positioning method for FOS in composite material's bonding.