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Blaise Pascal Medal in Chemistry

Professor Herbert Roesky

In recognition of the outstanding originality and creativity of his research in inorganic Chemistry

"Some highlights of main group Chemistry"

Silicon is after oxygen the most abundant element in the earth’s crust, followed by aluminum on place 3. Therefore we concentrated our research in the last two decades on these ubiquitous elements and developed new classes of compounds and improved their applications. Silicon is available in form of sand or quartz but for technical applications, this SiO2 has to be reduced to elemental silicon. This is a high energy consuming process. Moreover, this silicon contains too many impurities and has to be converted to trichlorosilane (HSiCl3). The latter compound is a distillable liquid and this allows removal of all impurities. Finally, it has to be reduced with molecular hydrogen to elemental silicon. However, this process has two disadvantages. On the one hand, it is again a high energy consuming process and on the other hand, silicon tetrachloride is formed in high yield as a side product. The latter has only limited commercial uses. This process is therefore economically not favourable. I will report on an alternative method and some exciting chemistry.

Presentation (power point file)
Lecture (video .mp4)

Blaise Pascal Medal in Earth and Environmental Sciences

Professor Corinne Le Quere, in Climate Change studies and policies

In recognition for her outstanding contribution to marine biogeochemistry and climate sciences

"Drivers of recent trends in the carbon cycle and implications for climate change"

With the Paris protocol in sight, this presentation will review recent trends in carbon emissions and their partitioning among the atmosphere, land and oceans – the so-called ‘carbon sinks’. The presentation will detail how CO2 emissions from fossil fuel combustion and land-use change are estimated based on combined biogeochemical processes and socio- economic statistics, and discuss their uncertainty. It will highlight the evolution of CO2 emission, their regional partitioning and drivers, and discuss the anticipated trends considering the underlying uncertainty, historical precedents, and model scenarios. On average 55% of the total emissions of CO2 are absorbed by the carbon sinks. The sinks are sensitive to the emissions trajectory, to the level of CO2 concentration in the atmosphere, and to climate change and climate variability. The presentation will show how the contribution of each of these processes can be quantified. The analysis of recent trends suggests that recent climate change is already affecting the carbon sinks in a way that exacerbates the rise of CO2 in the atmosphere. Both semi-arid regions (on land) and the Southern Ocean have been shown to be the source of large variability. Additional insights into the functioning of the carbon sinks could be gained by making use of the increasing availability of decadal constraints on the individual components of the carbon cycle. Based on our current understanding of the carbon cycle, the presentation will comment on the likely trajectory of atmospheric CO2 in the coming decades and on the implications for climate change projections.

Presentation (power point file)
Lecture (video .mp4)

Professor Christos Zerefos, in Atmospheric Physics

In recognition for his outstanding contributions for several decades to Atmospheric Physics, especially concerning the atmospheric ozone problem.

"Our Environment and Art"

Art has been influenced by our environment since the dawn of the humans in our planet. The lecture will cover the effects of global and regional changes as depicted by artists in the past centuries. Global changes are also influenced by large volcanic eruptions. Red-to-green ratios as depicted in paintings by great masters in the past and with digital cameras at present can provide important environmental information towards estimating aerosol optical depths at sunsets. The method has been tested at a number of large known volcanoes in the past and provides an estimate that has been tested with a large number of cases. Following large volcanic eruptions, statistically significant excursions of red-to-green ratios have been observed and radiative transfer model calculations were used to compile time series of aerosol optical depths at 550nm over northern middle latitudes. The Tambora eruption is among the most prominent AOD phenomena of the past few centuries as far as the red-to-green ratios in historic paintings are concerned. Comparisons with different proxy methods with the proposed chromatic method will be presented for the case of the Tambora eruption in an attempt to further quantify and rank the phenomenon and its environmental consequences. Different influences on artists range in other arts such as sculptures and music, dance, poetry and literature.

Presentation (power point file)
Lecture (video .mp4)

Blaise Pascal Medal in Materials Sciences

Professor Ulrike Diebold

In recognition for seminal contributions on the structure and properties of metal-oxide surfaces and their application in catalysis, and for sustained leadership in Materials Science

"Surfaces of Metal Oxides, Studied at the Atomic Scale"

Surface science studies of metal oxides have experienced a rapid growth during the last two decades. The reasons for this surge in interest are quite clear: after all, most metals are oxidized under ambient conditions, so in many instances it is the oxidized surface that deserves our attention. In addition, bulk metal oxides exhibit an extremely wide variability in their physical and chemical properties. These are exploited in established and emerging technologies such as catalysis, gas sensing, and energy conversion schemes, where surfaces and interfaces play a central role in device functioning. Hence a more complete understanding of metal oxide surfaces s desirable from both a fundamental and applied points of view.

The first challenge is simply finding out how a surface looks like: the regular, periodic arrangement in a lattice inside solid is often perturbed by the presence of a surface or interface. Once the geometric structure of an ideal surface is established, understanding defects is the next challenge. No surface is ever perfect. In particular for metal oxides imperfections such as missing atoms or step edges are often the most interesting aspect, as they affect the local electronic structure and surface chemistry. Surface structures and defects can be directly observed with Scanning Tunneling Microscopy using model systems under idealized conditions. In the talk I will give examples of such surface science results, and will try to relate the gained fundamental insights to applications.

Presentation (power point file)
Lecture (video .mp4)

Blaise Pascal Medal in Mathematics

Professor Luis Vega

In recognition for seminal contributions on the harmonic analysis and of Fourier methods in partial differential equations

"The Talbot effect and the evolution of vortex filaments"

I will present an interesting connection between the well known Talbot effect in Optics with the dynamics of vortex filaments that evolve under the so called Binormal law.

Presentation (power point file)
Lecture (video .mp4)

Blaise Pascal Medal in Physics

Professor Manuel Garcia Velarde

In recognition for seminal contributions on the fluid physics and, in particular, interfacial phenomena at large

"Fluid Physics and Interfacial Phenomena"

The Physics of Fluids deals with phenomena and problems mostly at human level, daily life. Take some interfacial phenomena to mention a few I have been working with. As shown long ago by B. Franklin, a tea spoon containing two to three milliliters of oil, immiscible and lighter than water, may cover two thousand square meters the surface of a lake, thus permitting to estimate the size of a molecule (about twenty five Ängstrom). A soup spoon of active charcoal offers an adsorption surface of several square kilometers, useful to trap bacteria and other tiny dirty stuff including gases. The O2/CO2 exchange in our lungs is done on a surface of about a hundred square meters, a process jeopardized in certain newborn babies unable to produce a particular surfactant phospholipid. Fluid Physics deals with flows and their stability, capillarity, patterned convection, surface and internal waves, tsunami, freak/rogue waves, turbulence, etc To account for fluid and flow behavior we need statistical mechanics and kinetic theory, otherwise we are in trouble to understand how from microlevel (atomic/molecular motions and their collisions) emerges mesolevel (fluctutations, phase transitions) and macrolevel (say thermodynamics and hydrodynamics). The understanding of wetting and spreading processes (including the formation and stability of colloids like paints and others) was possible only when theory combined elements from quantum electrodynamics, thermodynamics and hydrodynamics at the nanolevel. Useful metaphors can be extracted from knowledge of fluid physics. Recently, building upon the hydrodynamic framework used to describe how a surfer does on a bore in a river, I have developped a theory of (nonlinear) electron transport by considering electron surfing on soliton-like waves in (anharmonic) crystal lattices.

Presentation (power point file)
Lecture (video .mp4)

Blaise Pascal Medal in Social Sciences and Humanities

Professor Martin Carrier

In recognition for his scientific work as philosopher and historian of sciences, leading from epistemology to society

"Methodological challenges of the commercialization of scientific research"

The strong application pressure on science raises the question whether letting economic powers set the research agenda hurts science in methodological respect – as many critics suggest. In fact, cases of research projects and research findings can be identified that betray one-sided interests and modes of evaluation. However, the traditional ideal of objectivity as neutrality is out of reach in areas that are subject to strong non-epistemic interests. A pluralist understanding can help capture important aspects of the notion of objectivity. Further, the direction of research can often be successfully influenced by setting suitable incentives. In contrast to the traditional understanding, science can often be directed into specific pathways and toward certain practical achievements. However, epistemic research is still needed to make application-oriented research sustainable. Epistemic research is needed for creating a sufficient reservoir of knowledge to be tapped and for prompting a multiplicity of approaches in the scientific community.

Presentation (power point file)
Lecture (video .mp4)