Marine pollution

Marine pollution as seen by ultrafast cameras

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Ultrafast cameras unveil processes that are invisible to the naked eye. At Mines Alès, Pierre Slangen, a specialist in applied optics, uses them to build advanced technology devices and thus to understand how gases and liquids are diffused during environmental disasters.

 

 

Certain physical phenomena occur in such small time scales that they remain practically invisible without the use of sophisticated cameras and state-of-the-art laser devices. At Mines Alès, Pierre Slangen’s field of specialism has developed a research theme in the field of applied optics in new technology, for visualizing pollutants in aquatic environments. As early as 1993, before earning his State Doctorate in Belgium, he characterized materials through the use of holograms, measuring movements of just 0.5 µm. He continued his work in this field in 1995 when he joined Mines Alès. In 2003 he collaborated with a team as part of the Clara project with Cedre, Ifremer, Météo France and Inéris that was building a new IT system designed to help decision-making to deal with chemical substance spills at sea. All that remained was to observe the development of such spills in the water in detail. There is increasing research into viewing the invisible, from traces of nanoparticles to certain gases and chemical products, thanks to the possibilities offered today by ultrafast cameras. “They enable us to discover a significant amount of extreme processes whereby optics, although it does not always enable us to see, at least enables us to distinguish”, Pierre Slangen explains.

 

 Evaluating and anticipating industrial risks

Stakeholders in the oil and gas industry have been expressing their need for modelling tools for offshore leaks for several years. The accident at the Deepwater Horizon rig in 2010 highlighted the importance of such detailed knowledge of underwater phenomena and their consequences at the surface. In 2011 the METANE (Modeling undErwater gas/oil blowouT And lNg lEak) collaborative project received a double accreditation from the French Pôle Mer Bretagne Atlantique and Pôle Mer Méditerranée, as well as funding from the FUI (French Unique Interministerial Fund) to develop such a decision-making tool for industrial hazards linked to underwater leaks of oil, natural gas or liquefied natural gas (LNG) at sea. This 3-year project has received total financial support of €330 k. METANE is also a grouping of major public and private-sector actors, each of whom contribute their own expertise: Alyotech, Cedre, Nymphea Environnement, Mines Alès and GDF SUEZ.
Ultimately, the developed tool enables plans to be defined for the prevention and management of disasters, focused on the risk of accidents in relation to underwater hydrocarbon leaks. In order to calibrate and validate the digital model the project required laboratory trials both at Mines Alès and in situ at the Cedre in Brest. These trials allowed the trajectory, dissolution and rising speed of gas bubbles or oil droplets in the water column to be studied using optics. The project is focused on safety and the environment and aims to provide an understanding of the risks for personnel and equipment of off-shore installations.

Ultrafast imaging

Now essential in the fight against marine pollution in order to detect minute drops of pollutants or the ejection of gases with highly complex dynamics, these high-frequency cameras offer a better understanding of the way different fluids mix with each other. When a chemical tanker sinks, the products it was transporting can indeed behave differently within the water column. These non-linear fluid mechanics, which occur across very short periods of time, a matter of just milliseconds for some, must therefore be observed in detail in laboratories using experimental trials. Thanks to these cutting edge cameras it is now possible to ‘stretch out’ periods of time. The frequency of frames can be as much as a million per second: a far cry from the cameras for use by the general public, which rarely exceed 50 frames per second! The highest frequencies allow us to see how matter structures itself in space.

The ultrafast cameras used by Pierre Slangen and his team, which sometimes work at a rate that is much faster than the speed of time as we perceive it, allow micro-processes to be filmed and then viewed in fine detail. Slowing down time allows us to make out what happens in each time interval, from microseconds to seconds, something that is essential for understanding the dynamics of how chemical products spread when a ship sinks or during the explosion of a gas contained in a pipe. For Laurent Aprin and Frédéric Heymes, the team’s researchers in fluid dynamics, the results obtained in the field of optics allow a better understanding of how a chemical product diffuses as it rises through extreme temperature and pressure conditions when a ship sinks in deep water. This leads to an improvement in predictions of the amount of product to be handled by clean-up operations at the surface and in the air surrounding the site where diffusion is to be controlled (explosiveness, toxicity etc.)

 

Illumination using lasers

Such high speed imagery requires suitable illumination, so Pierre Slangen’s team builds complete devices where the light is supplied by superluminescent LEDs, or by laser pulses that emit light beams in the form of flashes. These devices vary according to the problem: an oil droplet mixing with water cannot be compared to the change in shape of a piece of laminate sheet metal for a vehicle, the artificial limb of a Paralympic athlete such as Dominique André at the Olympic Games in Sydney in 2000, or the device set up by the Zéline Zonzon dance company who wanted to show that dancers perceive and displace the air around them. “I used to be a developer of specific techniques, today I am a builder. I always tell my students that if you do not master the contents of a box, you will not master the box”, Pierre Slangen explains.

The work does not stop here, however. Not satisfied with building the best devices, Pierre Slangen wants to qualify them. He and his team mathematically quantify these methods from a metrological perspective and evaluate the deterioration of information linked to measurement uncertainties such as noise inherent to the coherence of the laser source and distortions that are intrinsic to the cameras and their lenses.

The advantage of these optics techniques for field measurements, especially in terms of diffuse light, is that they are well adapted to non-destructive testing and the measuring of fields of movement in 3D for solids and fluids thanks to their high level of sensitivity and excellent spatial resolution. The use of mechanical trials based on techniques like the correlation of images and the measurement of interference in diffuse light, produces cinematic fields which enable identification of the behavior of the materials studied.

Pierre Slangen’s next challenge is to observe larger fields (1 m2) using a resolution of 1 µm. This would require fast sensors of tens of millions of pixels… which don’t exist yet. The idea is to emulate the astrophysicists in Chili who, with the European Southern Observatory’s Very Large Telescope, are testing out multiplexing. They put together small images with an excellent resolution. Understanding of micro-phenomena is being added to that of the infinitely big.

 

Portrait_PS_pour_blogPierre Slangen entered the field of visualization techniques during his Master’s in Optoelectronics. At the time he was keenly interested in the creation of holograms: images in three dimensions that do not require special glasses. After a State Doctorate thesis in 1995 at the Belgian University of Liège, he is now a Research Professor at Mines Alès and has been accredited to lead research since 2013. He joined the Institut des Sciences des Risques team at Mines Alès in 2010. He is currently leading contractual work on the analysis of fragmented jets of liquid using imaging, confinement loss through very high velocity impact in reservoirs, and the study of atmospheric transfer as well as oil or liquefied natural gas (LNG) leaks at sea. He shares his knowledge through his lessons on sensors, applied optics and holography as well as by participating in television programs. To find out more

Editor: Umaps

Biomécanique au service de la santé

Biomechanics serving healthcare

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Stéphane Avril, a researcher at Mines Saint-Étienne, describes himself as a “biomechanics” but would like to become a “mechanobiologist”, a switch from studying the mechanical properties of the body to decoding its biological mechanisms using engineering tools. Focused in particular on analysis of the behavior of normal and pathological vessels, his work should have significant consequences on treatment for various vascular illnesses, and has already led to several industrial partnerships.

 

“Research at Mines Saint-Étienne was originally organized around three main activities: mechanics and materials, manufacturing and processes engineering, and company performances. After adjustments and reorientation within the manufacturing industry in France, the idea emerged of setting up an ‘Engineering and health’ research center, which would develop the School’s three main activities but orientate them towards the fields of biology and medicine”, explained Stéphane Avril.

The researcher was hired in 2008 to develop biomechanics in health, a discipline that analyzes the mechanical behavior (movements, deformations) of tissue and organs (blood circulation, articulations etc.). He has been managing the ‘Engineering and health’ center at Mines Saint-Étienne, made up of sixty or so people, since 2010.

 

Two main themes: vessels and compression

The work of the biomechanics team led by Stéphane Avril, composed of twenty or so engineers and researchers, has a “double backbone”, he explains. “The first subject, more biologically-themed, tends towards predicting the development of certain cardiovascular illnesses, such as aneurysms (dilatations) of the aorta, thanks to studies on the resistance of the vascular wall”. The second focuses on the treatment offered by medical fabric in the general sense including, principally, compression stockings but also knee braces, lumbar belts etc. “This second field was developed at the request of certain industrial players. The region is the largest in Europe for manufacturing these textiles”, the researcher added. “The approach we have adopted entails working on an application, such as a piece of software, in order to see if it can resolve a medical problem. This translational research, driven by its practical benefits, is one of the school’s specialties.”

 

Biomécanique au service de la santé

Predicting the effects of elastic compression on a subject’s leg

A team recognized for its research in the treatment of aortic aneurisms

Since 2008 the biomechanics team has been working with vascular surgeons at Saint-Étienne who implant stent grafts (prostheses placed inside the diseased vessel) in patients with aortic aneurisms that are in danger of breaking, with the aim of protecting the aneurism sac from the blood flow. This operation rebuilds a solid aortic ‘wall’.

Stéphane Avril has started an important program that has received grants from the French National Research Agency (ANR). The program’s objective is to better adapt stent grafts to the characteristics of the aneurism through mechanical calculations and the use of industrial software. “These questions, which may seem applied research, have raised fundamental issues that have been acknowledged by the international community”, the researcher indicated. In particular the team is interested in enzymes (metalloproteases) and their participation in the weakening then dilation of the artery wall.

In December 2014 Pierre Badel, a researcher in the laboratory, was given a ‘starting grant’ by the prestigious European Research Council (ERC) for his work on the prevention of aneurism rupture as part of the AArteMIS (Aneurysmal Arterial Mechanics: Into the Structure) project. At the beginning of 2015 Stéphane Avril was also honored by the ERC with the ‘consolidator grant’ for the BIOLOCHANICS project. Through this project, the team of researchers aims to develop a new approach to treatment of aortic aneurisms. Mines Saint-Etienne will thus receive 3.5 million euros over 5 years for research into aneurism rupture. In addition, within 5 years Stéphane Avril’s team hope to identify the signs of arterial instability with the support of companies specializing in magnetic resonance imaging (MRI). Over time the research should lead to work on medication and regenerative cell treatments, in connection with industry.

All this work takes us from classical biomechanics (analysis of movements and deformations) to mechanobiology which aims to predict the changes in the microstructure of an organ, in this case vessels, taking into account the mechanical constraints acting on its location. We could even talk of cellular mechanobiology, inasmuch as the researchers at Mines Saint-Étienne attempt to understand better the influence of mechanical changes on the cellular working itself (protein constructions, chemical reactions etc.)

 

Atheromatous plaques in the carotid artery, coronary dilation complications: a better understanding

After starting at Mines Saint-Étienne, Stéphane Avril received funding from the ANR (French National Research Agency), using MRI to identify what may cause atherosclerotic plaques formed in the carotid arteries to break in patients.

Recently, the team’s biomechanics looked at complications of coronary angioplasty, work which consists of dilating the coronary arteries of the heart, shrunken by atheroma, in order to improve flow. One of these complications, called a dissection, occurs when part of the dilated coronary artery wall tears lengthways. Using simulations, Stéphane Avril and his researchers have identified the pathological processes that occur and have shown that some of these occurrences may be factors of secondary coronary obstruction.

A leader in medical compression

Within a few years Stéphane Avril’s team was a European leader in soft tissue biomechanics, “one of the cutting edge subjects at Mines Saint-Étienne”. The researchers are especially well-known for their work in the field of medical mechanical compression. Some of this research aims to better understand venous compression devices, associated with the wearing of contention stockings, and is carried out in collaboration with the companies Sigvaris and Thuasne which specialize in the manufacture of these fabrics. Thanks to a recent study using ultrasound by a young PhD student, in partnership with Sigvaris, it has been shown that elastic compression exercises a type of pressure on soft tissue that tends to reduce stagnant blood in venous microcirculation. This would explain the positive effect of contention on superficial varicose veins.

Other work, using magnetic resonance images, suggests that this compression has an effect on deep veins in the leg more through contraction of the leg muscles than by the passive transmission of pressure to the vein wall itself.

 

A good example of the importance of biomedical engineering

It is clear that Stéphane Avril’s work is an excellent illustration of the multiple possibilities made available by the development of biomedical engineering techniques, including a better understanding of physiological and pathological processes and an improvement of treatments.
Biomechanics and mechanobiology are necessarily multidisciplinary fields because they are situated at the interface of engineering, the health profession and industrial development, and should offer even more contributions in the years to come.

 

StéphanPortrait_Stéphane_Avrile Avril, cutting edge research
dedicated to health

Aged 38, he joined Mines-Saint-Étienne in 2008 as a professor and researcher. After a degree in math and studies in engineering followed by a PhD at Mines Saint-Étienne, he chose a career as a researcher in engineering sciences, first applied to the field of materials and then health. During his PhD thesis he applied new photomechanics technology to analysis of the properties of materials. Then in 2003 he worked in Châlons-en-Champagne in the mechanics and manufacturing laboratory, directed by Fabrice Pierron, at Arts et Métiers ParisTech, where he developed new mathematical tools for using photomechanical data. In 2006 a year spent in the laboratory directed by Jon Huntley at Loughborough University in Great Britain enabled him to better understand the advantages of MRI data for analyzing living tissue. Between May and August in 2014 Stéphane Avril completed his training with a sabbatical in the American laboratory directed by Jay Humphrey at Yale University in the USA, in order to start working on mechanobiology. In January 2015 he received the prestigious European research grant from the ERC.

Editor: Umaps, Corinne Tutin

Responsible lighting: the secrets to a good eco-innovation strategy

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On February 11, 2015 an open workshop will be held in Brussels to present the results of the European cycLED project. This research program has supported four SMEs in the lighting sector in their eco-innovation projects aimed at designing more efficient LEDs, from both an economic and an ecological point of view. Cédric Gossart, a researcher at Télécom École de Management, has studied the barriers that hinder eco-innovation in the LED industry, and the ways to overcome them.

 

“10 years from now, we will only use LEDs. They are beginning to replace all lighting technology.” The European cycLED project (Cycling resources embedded in systems containing Light Emitting Diodes) was therefore aimed at assessing the opportunities for creating new products and services based on LED technology. With €4 million of funding, as part of the FP7 program, it brings together 13 European organizations, and is led by Fraunhofer IZM. The project’s original approach involved supporting four SMEs in the lighting industry (Braun Lighting, ETAP, ONA and Riva) and helping them to eco-design more environmentally friendly and innovative LEDs that were adapted to their needs.

 

Reducing environmental impacts while creating value

Braun Lighting Solutions needed small urban lighting modules requiring little maintenance and being easy to repair. ETAP wanted to develop an LED with a long service life that could withstand extreme conditions: for example, corrosion due to exhaust gases in parking lots. ONA wanted a product that would be almost completely recyclable, with components that could be reused. Finally, Riva developed LEDs for warehouse lighting and a new business model: selling a lighting service rather than simply selling lighting products. “The environmental benefit,” Cédric Gossart explains, “is that this encourages the company to make its lamps last as long as possible. It’s a way of combating obsolescence.”

Although they pollute less than older light bulbs, LEDs are still not perfect. They contain rare and dangerous metals that are difficult to recycle. “Currently, if you want to recycle the indium and gallium in LEDs, you have to choose to recover one or the other. One of the partners, Umicore, is working on designing a way to separate them. At the start of the project, we didn’t even know if this was possible,” explains Cédric Gossart. This would both reduce the environmental impact and reduce the risk of shortages of these raw materials.

Social science researchers helped the SMEs to ensure their innovations would be viable and to develop true innovation strategies. Three European research institutes participated in the project. Ecodesign Centre in Wales (United Kingdom) drafted recommendations for managing rare resources throughout the LED product life cycle. Sirris, the Belgian collective center for the technology industry, worked on business models applied to eco-innovation. Finally, Cédric Gossart from Télécom École de management, worked with his team (KIND) to analyze obstacles that hinder the development of eco-innovation in Europe, and sought solutions to overcome these obstacles.

 

Overcoming the barriers to eco-innovation

“Eco-innovation allows new markets to be created and improves a company’s image, while also motivating employees and attracting talent from outside the company, because it meets a social need and reduces the environmental impacts.” Yet, despite these advantages, many barriers hinder companies that would like to adopt this approach. All in all, Cédric Gossart and his team of researchers listed and classified 144 obstacles, which are not specific to the lighting industry. “We then asked the four SMEs to assess them. 60% were deemed irrelevant.” The others were thoroughly analyzed, and the consortium then worked to provide solutions.

The main obstacle for companies is technological. It concerns the choice of the “driver”: the equipment that powers and controls the LED. “Although an LED can last over 10 years*, the driver is generally only guaranteed between three and five years, and can last an even shorter time. The drivers’ fragility constitutes one of the reasons for the rapid decline of an LED’s performance, contributing to the poor reputation of LEDs when they were first rolled out.” Certain SMEs have therefore decided to produce their own drivers in-house, in order to obtain high-performance LEDs. Others have chosen to train their staff to identify a good driver. “We sought solutions to help the SMEs with the problems they could not solve on their own.” The cycLED consortium therefore recruited the help of the Lighting Europe association in order to implement procedures for verifying the certification of the lighting products. As a result, on January 7, 2015, the association called for the reinforcement of pan-European cooperation and improved market surveillance.

This analysis also revealed new barriers hindering eco-innovation. “We realized that one of the tools aimed at supporting innovation – the patent – could in fact hinder it. LEDs are complex technological objects, and designing them requires the integration of several fields of knowledge, leading to inventions that are patented by competing companies.” It is therefore impossible to design a more innovative LED without getting involved in intellectual property disputes. To overcome this barrier, Cédric Gossart favors “a more open knowledge protection system.”

 

A workshop on understanding how to eco-innovate

Today, the cycLED project is entering a new phase. On February 11, 2015, an open workshop will be held in Brussels, open to all those involved in the lighting industry, as well as any companies interested in eco-innovation. The SMEs will present the results from the project – the LEDs they eco-designed – and will explain how they got started with this approach. “If it weren’t for this European project, these four SMEs would probably not have adopted this eco-innovation approach. Now they all intend to do more.” The idea is for these four experiments, and the tools developed by the researchers, to help other companies, including those from other sectors. This is the case for the obstacle analysis carried out by Cédric Gossart: “Because the project was aimed at helping the entire European lighting industry to adopt an eco-innovation approach, we are now expanding this eco-innovation obstacle analysis to include other companies in the sector via an online questionnaire.” With the secret hope of one day witnessing the creation of the ultimate eco-designed LED: a zero impact LED that is completely recyclable, and designed according to the cradle-to-cradle method…

* Or 30,000 hours: at 10 hours per day, every day, this equals a minimum of 10 years, or more if it is used less and the heat is properly dispersed.