Plenty of room for improvement

VIELE RÄTSEL Was AIDS mit Recycling zu tun hat

ALLES BIO Warum die Zukunft der Bi-

oökonomie gehört

GROSSES POTENZIAL Wo Graphen eingesetzt

werden könnte

Jülicher

Meisterwerke

Wie Ingenieurskunst die Forschung voranbringt

1-1 8

DAS MAGAZIN AUS DEM FORSCHUNGSZENTRUM JÜLICH

3-1 7

STIMULATING Treating strokes with

magnetic fields

PLAYFUL Virtual worlds

in research

HARMFUL

The consequences of climate change for wind energy

Plenty of room for improvement

How traffic in German cities can become less polluting

FORSCHUNGSZENTRUM JÜLICH’S MAGAZINE

1-1 8

Nice idea

Orange, purple, turquoise, red – Markus Cremer is hoarding over 50 bottles of nail polish in his drawer.

All this in the name of research, specifically: of brain research. Cremer and his colleagues at the Institute of Neurosciences and Medicine (INM-1) use it to bond glass plates with a wafer-thin brain cut between them.

With the brain section fixed in this way, the structures of its nerve fibres can be made visible with the aid of light. “We’ve tried a lot. Nail polish is simply the best for gluing two plates together.

It dries quickly, holds well, can be easily removed again – and it always comes handy with a brush for application,” says Cremer.

NE WS IN BRIEF

5

COVER STORY

Bad air in town

Catalytic converters, clean fuel and new infrastructure – what

researchers are working on to improve air quality in cities.

8

RESE ARCH

Wind energy in transition

Winds in Europe could change in the future: possible consequences of

climate change on energy supply.

16

Volcanoes as a climate factor

Global impact of volcanic eruptions determined by

season and location.

18

A paradise for gamers

How virtual reality advances research.

22

Back from the scrap heap

Researchers unravel charging processes of

iron-air batteries.

25

Magnetic help for the brain

How stroke patients could be treated in future.

26

SECTIONS

Editorial

4

Publication details 4

What are you researching right now?

21 2.2 plus

30 Thumbs up

31

Research in a tweet 32

WASSERSTOFF

H CO²

2O

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effzett Forschungszentrum Jülich’s magazine, ISSN 1433-7371 Published by: Forschungszentrum Jülich GmbH, 52425 Jülich, Germany Conception and editorial work: Annette Stettien, Dr. Barbara Schunk, Christian Hohlfeld, Dr. Anne Rother (V.i.S.d.P.)

Authors: Marcel Bülow, Dr. Frank Frick, Christian Hohlfeld, Katja Lüers, Dr. Regine Panknin, Dr. Arndt Reuning, Tobias Schlößer, Dr. Barbara Schunk, Brigitte Stahl-Busse, Dr. Janine van Ackeren, Angela Wenzik, Erhard Zeiss

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Print run: 6,000

Publication details

The air is getting thinner for diesel cars

Honestly, would you buy a diesel car right now? Emissions scandal, unresolved retrofitting, impending bans on vehicles, depreciation – the list of counterarguments is formidable. So, it comes as no surprise that the neighbour across the street chose a petrol engine. Many others did as well: in January 2018, registration of diesel cars was almost 18 per cent below the previous year’s level. The car manufacturer, Toyota, has al- ready bid farewell to the diesel car, the French PSA Group is still waiting.

VW, on the other hand, believes in an imminent renaissance – claiming that the EU cannot achieve its CO

₂

targets without diesel cars.

We ventured a look into the crystal ball and pondered the question as to how the polluted atmosphere in cities could develop. Jülich research- ers are pursuing different approaches to enable mobility that promotes clean air – from a new diesel catalytic converter and alternative fuels to the question of whether we can and should afford electromobility. Read more in our cover story.

Other contributions also look to the future, such as the treatment of stroke patients with magnetic fields or how climate change could affect the generation of wind energy.

We hope you enjoy reading this issue.

Your effzett editorial team

Now also available as an online

magazine

More

inside!

E L EC T R O NI C SYS T E M S

Motion detectors

Recording the movements of athletes and patients with high precision – a technology developed by Jülich experts makes this possible. What is new is that high-frequency radio signals are used to detect movements at millisecond intervals and with

millimetre accuracy. The system could improve medical diagnostics and rehabilitation or even control robots.

– C E N T R A L I N S T I T U T E O F E N G I N E E R I N G , E L E C T R O N I C S A N D A N A LY T I C S –

Scientists from Jülich and the Bonn research institute Caesar have discovered how sperms navigate: the tail of sperm cells swings back

and forth, but with two different, overlapping frequencies. This propels the tail more to one side so that, depending on the kind of overlap, sperm cells swim in a curved fashion. These results help to better understand not only so-called biological microswimmers such

as bacteria or sperm – the scientists are also hoping for advance- ments in the development of synthetic microrobots.

– I N S T I T U T E O F C O M P L E X S Y S T E M S –

B I O P H YSI C S

Sperms on the

curved lane

Jülich scientists, in cooperation with an international team, have deciphered the molecular structure of the light-sensitive protein channelrhodopsin-2. It is one of the so-called light switch proteins: built into nerve cells, it can deliberately switch the cells on and off by means of light. This is expected to help analyse neurodegenerative

diseases more precisely and thus develop possible treatment methods.

Only when the structure of the molecule is known can switching be understood and can also be adapted to meet other needs.

– I N S T I T U T E O F C O M P L E X S Y S T E M S –

Light switch for nerve cells

4 measuring stations ... ^, 800

... from all over the world have contributed data for a new study on ozone concentrations at ground level. Result showed that the average concentration in Europe and North America has declined over the last 15 years, while it increased

in some regions of East Asia. The authors of the study attribute the increase in East Asian countries

to their economic boom and associated emissions.

The study is based on the world’s largest data archive on air quality, which Jülich experts set up in autumn 2017. It includes data from

over 9,000 ozone measuring stations.

– I N S T I T U T E O F E N E R GY A N D C L I M AT E R E S E A R C H / J Ü L I C H S U P E R C O M P U T I N G C E N T R E –

A new “organic ink” for 3D printers is particularly suitable for preparing structures on which cartilage material, nerve tracts, pieces of skin or entire organs can

be grown. The organic ink consists of a biocompatible polymer and water. During their investigations at the small-angle neutron scattering facility (picture) at the Jülich branch in Garching, Jülich neutron researchers discovered that the ink apparently owes its properties to a sponge-like nanostructure. It was developed

by scientists from Würzburg.

– J Ü L I C H C E N T R E F O R N E U T R O N S C I E N C E –

NE U T R O N RESE A R CH

From organic ink

to organ

Prof. Rafal Dunin-Borkowski, director of the Ernst Ruska- Centre in Jülich, has received a

“Proof of Concept” grant from the European Research Council.

With the prize money of 150,000 euros, he will build an open software platform for evaluating the large amounts of data yielded

by new methods in electron microscopy.

DISTINGUISHED

Electrotechnician Dr. Bugra Turan has won the Innovation

Award of the State of North Rhine-Westphalia, endowed with 50,000 euros, in the “young talent”

category. He received the prize for a flexible and practically applicable design for artificial photosynthesis, which he devel- oped at Jülich’s Institute of Energy

and Climate Research.

INNOVATIVE

According to the analytical platform “Web of Science”, five Jülich scientists are among the

most cited authors in their fields:

the neuroscientists Prof. Simon Eickhoff and Prof. Karl Zilles, the plant scientist Prof. Björn Usadel, Dr. Martin Schultz from the Jülich

Supercomputing Centre, and the battery researcher

Prof. Martin Winter.

MUCH-QUOTED

The expansion of the Jülich supercomputer JURECA will triple its computing power to 7.2 petaflops. This makes JURECA one of the fastest supercomputers in Europe. Dr. Estela Suarez from

the Jülich Supercomputing Centre is manager of the DEEP projects in which the concept

was developed.

What is so special about JURECA?

Its innovative modular architecture, which combines two different types of computers – clusters

and boosters. This has a similar effect to that of a turbocharger on a combustion engine:

both performance and efficiency are increased.

How does that work?

The booster module accelerates the cluster module’s calculations. This is achieved through division of

work: the cluster module performs complex calculations, while the booster module handles

programme parts that can be divided into many small, simple tasks.

Who benefits from these advantages?

This architecture is specifically tailored to scientific simulations – for example in brain and

climate research.

T H E I N T E R V I E W WA S C O N D U C T E D B Y R E G I N E PA N K N I N .

T HRE E Q U ES T I O NS FO R D R . S UA RE Z

Boosting JURECA

NO2

NO²

NO2

NO²

NO²

NO²

NO²

NO² NO²

NO² NO²

NO² NO2

NO2

NO2

NO2

NO2

NO²

NO2

Stuttga rt

The mobile Jülich measuring laboratory MOBILAB can measure numerous air pollutants while driving, including nitrogen oxides, particulate matter, sulphur dioxide and ozone. The researchers thus determine, at one-second intervals and with high spatial resolution, how air pollutants are distributed in cities and who causes them.

More about MOBILAB at:

effzett.fz-juelich.de/en

Bad air in town

In many congested areas, nitrogen oxides and particulate matter take people’s breath away. Most of the pollutants come from road traffic. What can be

done against bad air in the cities? We will set off on a journey through time into

the “German Particulate Matter Capital”. It begins in the past.

NO2

NO²

NO2

NO²

NO²

NO²

NO²

NO² NO²

NO² NO²

NO² NO2

NO2

NO2

NO2

NO2

NO²

NO2

Stuttga rt

Neckartor

NO2 NO2 NO2

NO2 NO2 NO2

NO2 NO2 NO2

NO2 NO2 NO2

> 90 µg/m³

Kernerstraße

> 30 µg/m³

T

he morning rush hour traffic on the main road B 14 is inching towards the city centre.

Dr. Robert Wegener is sitting behind the wheel of a silver-coloured mini truck. He points to a grey box, about twice the size of a wardrobe, past an elongated S-curve. “This is the measuring station at Neckar- tor,” says the scientist from the Institute of Energy and Climate Research (IEK-8). “We’re at Germany's dirtiest intersection.

Nitrogen oxides regularly reach maximum levels here.”

The measuring station is part of a network of some ten, per- manently-installed units that monitor air quality in Stuttgart’s urban area. In addition to nitrogen oxides (NOx), they also record particulate matter, the concentration of which is also regularly above the permissible limit values there. The fact that Stuttgart is the number one German city with the dirtiest air is also due to the Swabian metropolis being situated in a basin. Under unfavourable weather conditions, pollutants cover the city under a haze dome.

Air quality in other major German cities is about as bad.

According to the German Environment Agency (UBA), 70 mu- nicipalities exceeded the EU limit value for nitrogen dioxide in 2017. “Air pollutants in city centres have been a problem for decades. Even though there was a slight downward trend in nitrogen oxides, concentrations are still far too high overall,”

says Robert Wegener. Road traffic is one of the main sources of air pollutants, causing almost 40 per cent of nitrogen oxide emissions in 2016 according to the German Environment

Agency. The majority comes from diesel engines. Particulate matter is also produced by burning fuel, but also by the abra- sion of tyres and brake linings.

The mini truck has meanwhile left the Neckartor measuring station behind and is going down the B 14 south to Charlotten- platz. The mobile laboratory MOBILAB is on board. While on the road, it measures at one-second intervals the concentra- tions of well over a dozen air pollutants: for example, in addi- tion to nitrogen oxides and particulate matter, ozone, sulphur dioxide and hydrocarbons are also measured.

MOBILAB offers an important advantage compared to the fixed-location measuring stations: “We do not only measure at one single point, but also drive along the roads and deter- mine the local pollutant values. That’s how we can tell that the pollution is not evenly distributed. We record high values on the main road, up to 180 micrograms NO₂ per cubic meter of air.

The values are already much lower if we drive only a few metres further into the residential area, however. They may sink to a twentieth. This is of course of great interest to the residents,”

explains the chemist from Jülich.

Permanently high values such as those directly at the B 14 affect the health of local residents. Many municipalities are therefore making efforts to improve air quality in the city centres. The spatially and temporally measured high-resolution values of the Jülich researchers are a great help in this. They are included in a computer model that urban planners can use to develop strategies for air pollution control. However, no city has found a patent solution for reducing nitrogen oxides and particulate matter as of yet.

2017

Stuttgart. A deep construction pit is gaping in the middle of the city.

The reconstruction of the main station is progressing slowly. Several times this year, particulate matter alerts have

been declared during which the city requests its citizens to voluntarily abstain from going by car. The response

has been low – driving bans are imminent.

Mind the side effects!

Diesel driving bans indeed reduce NO₂ emissions, but may increase the amount of ground-level ozone. Ozone irritates the respiratory tract. Increased values are particularly problematic for people who are susceptible to breathing difficulties such as asthmatic patients.

More about this in the online edition at:

effzett.fz-juelich.de/en

i

NO2

NO² NO² NO2

NO2

NO² NH3

NH3

NH³ NH³ N²

NO² NO2

NO2

N2

N2

N² N²

N² N²

N2

N2

N2

NO² NO2

NO^x

D

r. Jürgen Dornseiffer is working on such a cata- lytic converter becoming reality. “I’ve got a ton of collaborative partnerships with whom I am developing an exhaust gas aftertreatment system to eliminate the nitrogen oxide problem in diesel cars,” says the chemist from the Institute of Energy and Climate Research (IEK-1).

Nitrogen oxides are generated when fuel is combusted.

The fact that diesel engines emit more nitrogen oxides than petrol engines is due to their operational mode: in contrast to petrol engines, they operate in lean-burn mode, i.e. they burn the fuel with an excess of air. This leads to a high oxy- gen content in the exhaust gas, which prevents the nitrogen oxides that were generated from being directly converted back into harmless nitrogen by a catalyst. This can only be achieved by using additives such as urea solution, so-called AdBlue, to the exhaust gas. Despite this, many diesel cars, even those with the latest catalytic converters, still regularly exceed the specified limit value in street traffic. This is not only due to the technology: the diesel scandal revealed that some car manufacturers had manipulated their vehicles in such a way that they only complied with the limit values on the test stand.

A new catalytic converter for diesel vehicles is to reduce nitrogen oxides in a circulation process – without any additives.

Nitrogen oxide sources in the transport sector 2016

Source: German Environment Agency

67 %

diesel passenger cars

22 %

commercial vehicles

5 %

^buses

4 %

other passenger cars

2 %

^others

NO2

NO² NO² NO2

NO2

NO² NH3

NH3

NH³ NH³ N²

NO² NO2

NO2

N2

N2

N² N²

N² N²

N2

N2

N2

NO² NO2

NO^x

This is intended to change. Industry and science are currently working on cleverly improving the existing technology. How- ever, they are also developing new approaches such as Jürgen Dornseiffer’s. His catalytic converter resembles a small chemi- cal plant: a special ceramic material initially stores the nitrogen oxides from the engine. The system then converts them into ammonia as a gas during operation. This compound is stored temporarily as well. In the next operating phase, the ammonia reacts with the nitrogen oxides to form harmless nitrogen and water. Once the ammonia gas is used up, the cycle starts over with the storage of nitrogen oxides.

Previous catalytic converters for diesel vehicles require either a second tank for the urea or they must be cleaned regularly when the internal storage is full with NOx. For this purpose, ad- ditional fuel is injected into the engine so that sufficient auxilia- ry substances such as hydrogen are available in the exhaust gas.

They help to convert the nitrogen oxides. This, however, boosts fuel consumption. Thus, the Jülich method not only protects the environment, but also has a positive impact on drivers’ wallets, argues Dornseiffer: “It consumes less fuel because the catalytic converter does not have to be cleaned regularly. Or rather: it needs less urea solution, maybe none at all. It depends on the size of the motor.”

Besides research institutes, partners from the entire supply chain are also involved in the development: raw material suppliers, representatives of the catalytic converter industry and two automotive manufacturers. Dornseiffer expects the first prototypes to be ready at the end of the project in 2020, followed by the finished products potentially already coming onto the market two or three years later.

An efficient catalytic converter technology is the most quick and effective measure to reduce the emission of nitrogen oxides from diesel engines, according to Dornseiffer. In the long term, electric motors will prevail in many areas, but the transition to battery drive cannot be realized overnight: “And in the commercial vehicle sector, we will continue to depend on the combustion engine for the foreseeable future. I cannot imagine a 40-ton truck driving around with a 20-ton battery.”

2023

The reconstruction of the station is making progress. If the wind does not blow the pollutants out of the Stuttgart basin, the city will impose driving bans.

The air at Neckartor is breathable again.

In the rest of the city centre, the ave- rage values for nitrogen oxides have also fallen slightly. This is also due to the fact that fewer and fewer old diesel cars are about on the Stuttgart streets.

The new cars meet the emission limits

with new, effective catalytic converters.

H²

CO²

2030

The new through station has commenced operations. Local traffic flows more smoothly as a result; many commuters leave their cars sitting in the garage. The city railways have expanded their capacities accordingly. But there is more: part of the bus fleet now runs on electricity from renewable sources – with noticeable consequences for the

city residents, as the noise level on the streets has fallen correspondingly.

The types of engines used in cars have also become more diverse: electric vehicles with batteries or fuel cells are

on the road, but also a rising number of cars powered by natural gas or

synthetic fuels.

Liquid synthetic fuels are an alternative to fossil fuels. Ideally, they are based on carbon dioxide, which is separated from industrial waste gases or produced sustainably. Together with hydrogen – renewably made from water – various fuels can be produced from it.

Electricity

Hydrogen

Carbon dioxide

Liquid synthetic

fuels

Chemical plant Renewable generation

Industry Biomass

Elektrolysis

H²

CO²

R

esearchers are already working towards more environmentally friendly fuel. “If you want to make diesel propulsion cleaner, you can start at the engine. Alternative fuels are another possibil- ity”, explains Prof. Ralf Peters from the Institute of Energy and Climate Research (IEK-3). “We are focusing on these and looking for substitute compounds that are custom- ized, synthetic and that burn much cleaner than, for example, diesel: they generate significantly fewer soot particles, i.e.

particulate matter. One can then fully concentrate on reducing the amount of nitrogen oxides in the exhaust gas through the engine settings.”

According to Ralf Peters, anyone who wants to reduce the pollutant emissions of diesel vehicles via the engine settings alone will be on the horns of a dilemma: “If the particulate matter goes down, the nitrogen oxides go up – and vice versa.”

The nitrogen oxides result from the the diesel engine’s usually high combustion temperatures. If the temperature is lowered through partial exhaust gas recirculation, for example, less nitrogen oxides are formed, but the amount of soot particles increases.

Possible clean designer fuels for diesel engines are primarily of substances such as alcohols and ethers, which themselves already contain oxygen. Oxygen prevents carbon from accu- mulating to form solid soot particles inside the fuel droplets.

Methanol, the simplest of all alcohols, is considered promising – either directly as fuel or as a precursor for other synthetic fuels such as dimethyl ether (DME), oxymethylene ether (OME) or Fischer-Tropsch products.

“However, there is as of yet no optimum fuel. It is difficult to predict which candidate will win the race. On the one hand, the production processes and costs play a major role; on the other hand, so do the carbon footprints of the various fuels.

Even with synthetic fuels, CO2 is released during combustion,”

Peters points out. Comparing the production processes of vari- ous fuels is what primarily occupies him and his team.

Therefore, the synthesis should be as sustainable as possible, starting with the basic substances and including the various process steps to the necessary energy. Peters summarizes: “Not only air quality benefits from clean combustion in the diesel engine then, but also the climate.” For example, one possibil- ity is to break water down into its components hydrogen and oxygen – with excess electricity from wind and solar power plants. The energy carrier, hydrogen, obtained in this way can be converted into fuel with CO2 from industrial waste gases or power plants.

It is precisely this approach that Jülich researchers and part- ners of science and industry pursue in the Copernicus project

“Power-to-X” (P2X): electricity from renewable energies that is not demanded at times – “Power” – is to be used to produce various products – “X” – such as hydrogen as an energy carri-

er, chemical raw materials or alternative fuels. Specifically, the project partners are developing a way to produce OME sustainably. OME is already produced in small quantities today from a mixture of carbon monoxide and hydrogen, the synthesis gas. In the “P2X” project, several Jülich institutes are working with industrial partners to produce this synthe- sis gas sustainably in just one process step. Partners from Karlsruhe Institute of Technology, RWTH Aachen University, and from the industry will then convert the synthesis gas into OME or improved petrol and diesel fuels as well as kerosene.

Prof. Dr. Rüdiger-A. Eichel from the Institute of Energy and Climate Research (IEK-9), one of the three coordinators of

“P2X”, is convinced: “Power-to-X will play a role in all areas of life in the future, including mobility. In the same way that petrol and diesel engines coexist, future mobility will be diverse and depend on batteries, fuel cells and sustainably produced alternative fuels.”

Measures to improve air quality in cities

Source: www.vdi-nachrichten.com

Electric buses Retrofitting of commercial vehicles Urban landscaping Regulation of traffic

flows

Driving bans New tyre materials

270 ^billion

Hydrogen

H ² O

H ² O

H ² O H ² O

CO ²

CO ² CO ²

CO ²

40 ^billion

I

f the number of cars with battery or fuel cell drives on the road rises, the infrastructure must be adapted to this.

A sufficient number of charging stations is needed for battery-powered cars as well as hydrogen filling stations for fuel cell-powered cars. However, there are still many questions: is it affordable to set up a nationwide supply net- work in the first place and would such an infrastructure also be profitable? Which technology would be cheaper, charging current or hydrogen? Or will it be possible for both technolo- gies to coexist? Researchers from Jülich have analysed various future scenarios for the supply infrastructure. Dr.-Ing. Martin Robinius from the Electrochemical Process Engineering (IEK- 3) section summarizes the results: “Batteries and hydrogen are not mutually exclusive. Actually, we need both infrastructures and we can afford them as well.”

According to the industrial engineer, the changeover from fos- sil fuels to electric propulsion could succeed if electricity from wind and solar power plants also found its way into the trans- port sector. Many experts currently favour a purely electric solution with battery-powered cars as, due to our electricity grid, the distribution grid already exists and further charging stations could be built within a short time. Martin Robinius indicates a weak point, however: “In our future energy system, we need long-term storage for electricity. This is the only way we can get through weeks in which the sun and wind yield little energy. This cannot be achieved with batteries alone.”

This is where the energy carrier hydrogen comes into play.

It could be produced with the help of electrolysis equipment in times of abundant electricity yield and distributed via

pipeline network to hydrogen filling stations nationwide. Huge underground caverns in salt domes could be used as long-term storage facilities.

The profitability of both systems depends on how many vehicles with battery or fuel cell drives are on the country’s roads. Martin Robinius: “There are some 46 million cars on our roads today. We have examined a scenario for the year 2050 in which about half of this fleet, 20 million vehicles, is powered by fuel cells. Investments of around 40 billion euros would be necessary for the entire infrastructure.” In particular, the ini- tial investments for hydrogen are relatively high – for the huge underground gas storage facilities in salt domes, for instance.

In the long run, however, this would average out, as costs to build up the infrastructure for 20 million battery-powered vehicles would be around 10 billion euros higher in the same period. Charging time would become a critical factor for such a large number of vehicles. Particularly in cities, there are not enough parking spaces to conveniently charge the batteries of these vehicles with energy overnight. A proportional number of fast charging stations, which are particularly expensive, would have to be erected. Therefore, battery technology would only be cheaper in a transitional phase until about 2030 and for around 10 million cars each with battery or fuel cell drive, respectively.

“Even so, we recommend that we expand both systems, and that we do so as quickly as possible,” says Martin Robinius. “We can afford this and should afford this. In both cases, the total costs are significantly lower than investments in other essential infrastructure areas. The Federal Transport Infrastructure Plan euros. This is the amount of

investment required to set up a hydrogen infra-structure for

20 million fuel cell vehicles on Germany’s roads.

270 ^billion

Hydrogen

H ² O

H ² O

H ² O H ² O

CO ²

CO ² CO ²

CO ²

40 ^billion

¹⁵

2030 alone provides for total expenditure of approximately 270 billion euros to be spent on maintaining and expanding the road and rail network and waterways.

Robinius is convinced that Germany needs battery and fuel cell drives to meet its long-term commitments on CO2 emis- sions in the transport sector as well. “Setting up both infra-

structures is an investment that will pay off – not least because of air quality and lower health costs. A city where electric cars and fuel cell vehicles predominate has no problems with nitrogen oxides. And clean air is an asset to the health of the people living there.”

A R N D T R E U N I N G

Air pollutants and health consequences Selection

Source: German Environment Agency; Information system on hazardous substances of the German Social Accident Insurance; Karlheinz Lohs, Peter Elstner, Ursula Stephan (eds.): Fachlexikon Toxikologie, Berlin, Heidelberg 2009.

2050

The first redevelopment measures are due at the main station. More and more people are moving to the Stuttgart area. Therefore, traffic on the

road is on the increase again. The air quality still does not deteriorate. Filling stations for hydrogen have mushroomed

up in Stuttgart. Charging stations for electric vehicles can be found on every corner. Batteries and fuel cells

are now the dominant engines in passenger cars.

euros of investments in rail, road and waterways. This is what the German Federal Transport Infrastructure Plan

is budgeting for the period between 2016 and 2030.

NO₂ Headache, dizziness Eye irritation Asthmatic patients are at risk of bronchoconstriction, respiratory problems

Lung irritation

At high concentrations: pulmonary edemas

Particulate matter * Mucosal irritation

Local inflammation of the trachea and bronchi

Higher risk of lung cancer

Increased plaque formation in the blood vessels Higher risk of thrombosis

* Diverse consequences are possible depending on the size of the particles

Wind energy in transition

With climate change, wind conditions across Europe will change. Any electrical power supply that is substantially based on

wind energy must be adapted to this.

according to the models. In addition to global models, regional models provide detailed data for Europe. The researchers from Jülich used this data to determine the occurring wind forces – not the average values for the whole of Europe, but rather how strong the wind blows over individ- ual countries on the one hand and, on the other hand, how its strength changes within a few hours. They then fed the results into a computer model of the future European energy system.

They deliberately chose a very simple model in order to investigate the effects of climate change as directly as possible. This model does not take into account the extent to which energy con- sumption may change or which types of energy storage could catch on.

The first result: wind conditions in European countries will converge in the event of severe climate change. There will likely be fewer times in future when the wind blows comparatively strongly over one country while being calm in another. Accordingly, situations will occur more Central and Western Europe is counting on

renewable energies: more and more wind power plants are being incorporated into the power grid. It is possible that at some point they will supply as much electricity as is needed in a year – if only mathematically! There will always be hours, days or even weeks when a country is in a slump and produces too little wind energy.

Junior professor Dirk Witthaut warns that these phases could be more pronounced in the future and more difficult to compensate for by electrici- ty imports. The reason is: climate change. Witt- haut and his team have analysed how climate change could influence wind conditions and thus power supply in the coming decades.

The analysis was based on five computer models which are able to simulate how the climate will develop up to the year 2100 if the carbon dioxide concentration in the atmosphere follows a cer- tain pattern. For example, if the current level of 410 ppm rises to 1,330 ppm, the global tempera- ture will be four degrees higher than today

“Climate change can indeed damage

our energy

system.”

What is special about the presented studies?

Usually, what is investigated is how changes in the energy system impact greenhouse gas emissions and thus the climate.

We reversed the question: what will be the effect on energy systems if we do not succeed in limiting climate change?

In your studies you assume that, on the one hand and, an energy transition will take place throughout Western and Central Europe and on the other hand that the global tem- perature will rise sharply by 2100 – by four degrees. How does that fit together?

It can indeed fit together. It is possible that Europe will change course so late that the global rise in temperature cannot be limited to a maximum of – as currently envisaged – two degrees. Or maybe the rest of the world will burn so much gas and coal that the effect of the energy transition in Europe will not be sufficient to limit climate change. It is also imaginable that both scenarios might happen simultaneously. This danger does exist. We should therefore understand the consequences of all possible future scenarios. The German government, for example, recently had to admit that Germany will not achieve its self-imposed CO2 reduction target by 2020.

How realistic can a look at energy supply and climate when it reaches 80 years into the future?

Of course we know neither the extent to which the world will be taking climate protection measures nor how energy consumption in Europe will change. Still, system studies show interesting interrelationships that could become practically significant. In the case of our studies, the conclusion is that climate change can certainly damage our energy system.

We need to take this into account when planning our future energy system.

3 questions

for the energy system researcher Dirk Witthaut

F R A N K F R I C K

With him, it’s all about energy systems: Dirk Witthaut, Young Investigator Group Leader at the Jülich Institute of Energy and Climate Research (IKE- STE) and junior professor at the University of Cologne.

frequently in which European countries syn- chronously produce an electricity surplus – or in which, conversely, there is a shortage of wind power everywhere. For Germany, for example, this means less electricity can be imported and exported in order to equalise the balance be- tween generated and consumed electricity.

The second result: severe climate change will prolong lulls over Germany. To bridge these windless times, energy suppliers have to build more energy storage units or have more back-up power plants available than would be necessary for the current level of carbon dioxide in the air.

Volcanoes as a climate factor

Approximately 74,000 years ago

Toba, Sumatra

The consequences are controversial; possibly years of darkness with temperature drops of up

to 15 °C, plus a massive extinction of species.

Volcanic eruptions and their various consequences

2,800

cubic kilometres of rock and ash ejected,

VEI * 8

* VEI: “Volcanic Explosivity Index” with a maximum index of 8

Two volcanic eruptions of about the same magnitude – one causes serious global climate changes for years, the other remains a regional phenomenon.

In addition to the location, the season also influences whether a volcanic eruption has local or global effects. This is what satellite data

and a new computer model show.

1816 went down in history as the “Year Without a Summer”. Continuous torrential rain and cold temperatures destroyed the crops in large parts of Europe. In June, snow fell on the east coast of North America. China and India suffered from severe floods and droughts. The cause of hundreds of thousands of deaths, hunger and disease was – the eruption of the Mount Tambora volcano on 10 April 1815, located in current-day Indonesia.

According to calculations, the volcano spewed 160 cubic kilometres of rock and ash into the atmosphere. For comparison: this would fill Lake Constance three times over.

LOCATION IS A DECISIVE FACTOR

The eruption of Mount Paektu in the winter of 946 was similarly violent, with at least 100 cubic kilometres of ejected material. While this was a catastrophe for the region, scientists consider the effect on the global climate to be small. The rea- son was its location at 40 degrees north latitude

on the present border between North Korea and China. The air currents there are very different from those close to the equator, where the Tam- bora is located.

Volcanic ash and sulphur aerosol particles thrown into the stratosphere at 17 kilometres and higher near the equator, as was the case with the Tamb- ora, disperse over the entire globe. This is due to the special dynamics of the atmosphere in this region. In the tropics, the air rises very quickly and then spreads to higher latitudes with the prevailing stratospheric air currents, including the so-called Brewer-Dobson circulation. It takes years for these air masses, including their cargo, to sink back down to lower regions of the atmo- sphere across the polar regions.

Once they are distributed globally in the strat- osphere, the aerosol particles reflect the sun’s radiation back into space for years. This cools the underlying layers of air near the earth and can lead to extreme weather conditions all over the world.

Caspar David Friedrich: Mountainous River Landscape, 1830 – 1835 Between 1816 and 1835, landscape painters like William Turner or Caspar David Friedrich captured glowing red sunsets of breathtaking beauty on canvas. They did not know that the cause of the intense and unusual colours in the sky were volcanic eruptions in Southeast Asia. These hurled dust and aerosols into the atmosphere, which scatter the sunlight.

Lars Hoffmann from the Jülich Supercomputing Centre simulates the effects of volcanic eruptions on the atmo- sphere.

10 April 1815

Tambora, Indonesia

Three years of globally extreme climate with floods, droughts, crop failures and a global cholera epidemic. At Lake Geneva, which was hurled around by thunderstorms,

and influenced by the depressing weather and the hardship of the people, Mary Shelley developed the idea for her novel “Frankenstein” in 1816.

27 August 1883

Krakatoa, Indonesia

Huge tsunami involving tens of thousands of deaths. The spreading of ash in the atmosphere helped scientists, however, to better understand the global wind currents for the first time,

including the jet stream.

cubic kilometres of rock

20

and ash ejected, VEI 6

160

cubic kilometres of rock and ash ejected,

VEI 7

He and his colleagues investigated the eruption of Sarychev Peak on the Russian Kurils in summer 2009. This volcano is situated northeast of Japan at 48 degrees latitude. Between 11 and 22 June 2009, it ejected an ash and gas cloud reaching 12 to 18 kilometres high and around 1.2 million tons of sulphur dioxide along with it. The scien- tists analysed satellite observations of volcanic emissions as well as wind and weather data from meteorological analyses. Their computer simulations showed that the Asian summer mon- soon distributed the resulting sulphur particles throughout the northern hemisphere, also trans- porting around 60,000 tonnes to tropical regions.

In the tropics, the aerosol particles rose with the circulation, were dispersed into the stratosphere and from there, eventually spread over the entire globe.

It would have been completely different if Sary- chev had erupted in winter. “Our model shows that the aerosols would have then migrated rapid- ly towards the poles with the strong winter air currents, sunken into lower atmospheric layers there and been washed out of the atmosphere in a relatively short time,” said Dr. Xue Wu, guest researcher at the JSC and lead author of the new study. Thanks to the simulations, it could be resolved why satellite data had recorded an increase of aerosol particles in the tropical strat- osphere, although there had been no relevant volcanic eruption nearby. Because it erupted during the Asian summer monsoon, the Sary- chev volcano contributed significantly to a better understanding of the climate, fortunately without the serious consequences that the Tambora volcano had.

B R I G I T T E S TA H L-B U S S E

In contrast to this, aerosols from volcanic erup- tions further north or south – such as Mount Paektu –, on the other hand, mostly remain in their respective hemisphere and are washed out again relatively quickly through rain or snowfall as they descend into lower areas of the atmo- sphere. This is the current opinion in science.

INFLUENCE OF THE SEASONS

However, this is not always the case as satellite data and new computer simulations analysed by Chinese and Jülich scientists show. “Depending on the season, an eruption in mid and high lati- tudes – that is in areas far beyond the equator – can also have a global impact on the climate,”

says Dr. Lars Hoffmann of the Jülich Supercom- puting Centre (JSC).

20 March to 9 July 2010

Eyjafjallajökull, Iceland

No impact on the global climate, but air traffic over Europe was largely suspended for several days. The economic loss amounted to around

3 billion euros.

15 June 1991

Pinatubo, Philippines

At least 875 people left dead and 8,000 square kilometres of rice fields destroyed. Sunlight was reduced by 5 per cent for several years. As a result,

the average temperature fell by up to 0.6 °C in the northern hemisphere and by 0.4 °C worldwide.

cubic kilometres of rock

10

and ash ejected, VEI 6

0.2

cubic kilometres of lava, rock and ash ejected,

VEI 4 Eruption of the Sary-

chev Peak volcano on the Russian Kurils on 12 June 2009

What are you researching right now, Mr Elmenhorst?

“We sleep in order to recover. This is a conventional explanation. However, there is no reliable theory giving a satisfactory explanation to all the observations about sleep and sleep deprivation.

I am looking for processes in the brain that control sleep. For that purpose, my team and I are doing experiments with test persons who sleep in accordance with our specifications.

We measure how the concentration of neurotransmitters and their binding sites on nerve cells changes in the brain. The focus is on the neuromodulator adenosine, which influences the

energy balance of our body and our brain’s areas for waking up and for staying awake.”

PD Dr. David Elmenhorst, Institute of Neuroscience and Medicine, Molecular Organization of the Brain (INM-2)

Whether roots, fuel injection or na-

sal breathing: with virtual reality, scientific results may

not only be visualised, but also analysed.

This provides insight that cannot be gained in the real

world.

A paradise for gamers

Welcome to the virtual world: experts at the Jülich Supercomputing Centre make it possible to plunge into the results of scientific simulations such

as a computer game’s virtual 3D environment.

understand and attract attention. VR technology, which is gaining ground in the computer games market thanks to lower prices for the glasses and the other equipment, is also opening up new opportunities for science.

HOW IT FLOWS THROUGH THE NOSE

The Rhinodiagnost project is a prime example. It is aimed at helping to solve a medical problem:

in about 11 per cent of Germans, nasal breathing is chronically obstructed. Generally, an opera- tion can help, but the failure rate for such pro- cedures has a high estimate of 30 per cent. The most important reason for this: whether or not the attending physicians perform surgery de- pends mainly on the shape of the patient’s nasal cavity and paranasal sinuses. Physicians gener- ally do not know the flow conditions in the nose, however. It is exactly these that are decisive. The nose works perfectly when, among other things, it allows enough air to pass through to the respi- ratory tract and lungs and when it sufficiently heats and moistens the incoming air.

The visualisation specialists from Jülich collab- orate with the JARA Simlab “Highly Scalable Fluids and Solids Engineering”, the Institute of Aerodynamics of RWTH Aachen University, and with the industry to enable physicians to take the air flow into account for diagnosis in future. On the basis of computed tomographic images of the patient, supercomputers are to simulate the indi- vidual’s nasal air flow. “In order for physicians to understand these simulation results quickly and well, they need to be visualised – preferably in a familiar way,” says Göbbert. “In virtual reality, we can replicate the airways in a patient’s nose in detail, providing physicians with a world they know well.” With the help of VR glasses, the physicians will be able to move around there For some computer gamers, Jens Henrik Göb-

bert’s office would pretty much resemble paradise. The perfect basic equipment for virtual reality (VR) is there, from a powerful comput- er and modern VR glasses to the rod-shaped controller – in short, the next level on the game market, in which players explore almost lifelike worlds. If you visit Göbbert, you can put on the clunky glasses, take the controller in your hand and plunge into another sphere: one step forward in the office is one step towards a cosmos full of glittering little droplets. When you turn your head to the left, you see a silvery jet of liquid. Just press a button on the controller and the jet zooms in. Is this computer game relaxation for scientists and guests of Forschungszentrum Jülich?

No, of course it isn’t. Göbbert is a member of the

“Visualization” team at the Jülich Supercomput- ing Centre (JSC). He works on making scientific simulations visible. Researchers from different disciplines turn to him to visualise their results or to analyse them in more detail in virtual reality.

For example, the droplets and the jet of liquid are fuel injected into the engine by a nozzle.

Researchers of the Institute for Combustion Tech- nology of RWTH Aachen University want to im- prove this process. One challenge is the gigantic masses of data that arise during the simulation of the injection process. Göbbert and his colleagues are working on methods that extract the data for the respective visualisation directly from the sim- ulation: in the future, the images or the VR world are to be created “live” while the supercomputer calculates – without the data having previously been saved as is usually the case.

Just a few years ago, visualisation was primarily about translating the results of simulations into an image or a sequence of images. Images and animations usually make the results easier to

so-called game engine. A game engine is a program- ming framework used to design computer games. “In the computer game industry, thousands of specialists work on opening up ever-advanc- ing possibilities for gamers,” says Göbbert. “We benefit from this: it is effective and inexpen- sive for science to use these already developed VR techniques and to supplement them where science has special requirements.” Thanks to the interface with a standard VR system, Göbbert and his colleagues can immerse themselves into the virtual fuel jet or in the virtual air flow in the nose.

F R A N K F R I C K

and understand the air flow. They will also experience how surgical correction would affect the flow conditions – an important aid in deciding for or against surgery.

For this system, the Jülich experts use

software components that NVIDIA, the graphics card and chip manufacturer, had already pro- vided during the fuel injection project. After all, noses and injection nozzles are far less different for physicists and engineers than most people would think. The nozzle, too, only functions optimally if it ensures a perfect flow: the more evenly the injected fuel flow mixes with the air before combustion, the smaller the quantities of pollutants that an engine emits.

One of these components is an interface be- tween software for scientific visualisation and a

Dr. Herwig Zilken and his col- leagues provide unusual insight into the underworld: they are cur- rently preparing data from plant roots for virtual reality (VR). With VR glasses, plant researchers can then move, like in a computer game, through the three-dimen- sional root network. In this way, they can identify massive primary roots and how they branch out, but also where delicate shoots are disrupted due to a lack of mea- surement data.

This 3D journey has a scientific background. The plant researchers at the Institute of Bio- and Geo- sciences (IBG-3) want to under- stand how nutrients and water

get from the soil to the roots and spread there. They need a com- puter simulation for this. There is a problem, however: the biologists receive the root data using com- puter tomography (CT), an imaging method from medicine. “On the one hand, this is good because it allows them to analyse the roots without digging out the plant. On the other hand, the structure of the roots is often so similar to the surrounding soil that a computer cannot distinguish between root and soil. For the simulation, how- ever, this must be clear,” Zilken explains. As a consequence, the researchers must check the measurement data afterwards and improve unclear areas by hand.

“In theory, you could do this on a PC screen. There you see only two dimensions, however. That is why you always have to change views in order to precisely identify and mark nodes and complex branches,” explains Zilken. This is different in the VR world. “The researchers can move through the roots, quickly and easily change perspectives, and immediately mark where and how a root runs by clicking on the controller. In this way, they get the data for their subsequent simulation quickly and easily.”

Special networks

Jens Henrik Göbbert makes scientific results visible.

Lithium-ion batteries play the leading role in our everyday lives. They power smart- phones and tablets, but also electric cars and pedelecs. However, they have one serious disadvantage: lithium and cobalt, found in the electrodes and in the electrolyte of the battery, are rare – and thus expensive. The price of lithium, for example, has increased sevenfold in the last ten years.

AFFORDABLE ALTERNATIVE

This is why Jülich researchers are working on batteries that use other materials. One of them is the iron-air battery. Iron is abun- dant in the earth’s crust, it is inexpensive and extracted in large quantities – supply bottlenecks are therefore not to be expected.

Iron-air batteries draw energy from the reac- tion of iron with oxygen. The iron oxidises, which is similar to rusting. The required oxygen comes from the ambient air and does not have to be provided in the battery. The battery thus achieves significantly better energy densities – in other words, a large amount of energy can be stored per volume.

At the same size, an iron-air battery can store almost five times as much energy as a lithium-ion battery.

The iron-air batteries have already been known since the 1970s. In the 1980s, however, research stagnated in favour of lithium-ion batteries, which could be developed more rap- idly for release on the market. There were too many unanswered questions about the iron- air battery. So far, researchers had only been able to guess what really happens on the iron electrode during the charging and discharg- ing processes. “We were able to shed light on this now,” explains Henning Weinrich,

doctoral researcher at the Jülich Institute of Energy and Climate Research (IEK-9). “With an atomic force microscope, we observed for the first time the processes during charging and discharging – with nanometre preci- sion.” The result was surprising: both during charging and discharging, iron detaches from the electrode and is deposited on the same surface again soon after. Previously, it has been assumed that this only happens during discharging. The surface becomes increasing- ly jagged; that is, it becomes larger with each cycle – which is reflected in increasing charg- ing and discharging current densities and an increasing capacity. This means that at the beginning, the battery can store increasing amounts of energy even with coarse electrode structures until this effect finally reaches a limit.

With these findings, the Jülich researchers are creating a new basis for specifically improv- ing the properties of the battery. This brings market readiness one step closer.

J A N I N E VA N A C K E R E N

Back from the scrap heap

Iron-air batteries consist of raw materials that are available in large quantities.

Up to now, however, the charging and discharging processes had been unclear. Jülich researchers have brought light into the darkness, thus laying the foundation for

pre-commercial development of this type of battery.

Henning Weinrich, doctoral researcher at Jülich’s Institute of Energy and Climate Research (IEK-9)

Iron can store almost five times as much energy …

… as current lithium-ion battery

materials.

9.7 kWh/l*

2.0 kWh/l

* kilowatt hours per litre

Treating stroke patients with magnetic fields: while this sounds like faith healing, it has proven itself in research as transcranial magnetic stimulation. Scientists from

Jülich and Cologne are testing this method in a large clinical study – the first of its kind worldwide. Their long-term goal is individualised therapies.

Magnetic help for the brain

This is how the Jülich researchers Christian Grefkes (left) and Caroline Tscherpel hope to help stroke patients in the future:

a magnetic coil on the patient’s head inten- sifies or weakens the activity of nerve cells in the brain. Electrodes in the head cap simul- taneously measure the brain waves so that it becomes visible how the stimulation works.

Wilhelm Zeffler is one of around 270,000 people in Germany who suffer a stroke every year – this means that one person is affected every two minutes. 63,000 men and women die as a result.

Stroke is the fourth most frequent cause of death in Germany after heart disease, cancer and lung disease.

“The topic is affecting more and more people, because our population is ageing and so the number of stroke patients will continue to rise,”

says Prof. Christian Grefkes. After completing his medical studies, the 41-year-old specialised in strokes. Since 2005, in close cooperation with his long-time mentor Prof. Gereon Fink, he has been working and conducting research on transcranial magnetic stimulation (TMS) at the Institute of All of a sudden, Wilhelm Zeffler can no longer

move his left leg and left arm. The 74-year-old is crawling down the corridor towards the tele- phone when, fortunately, his wife comes home and immediately calls the ambulance. Things go very fast then: ambulance with flashing lights, paramedics and physicians in action. The preliminary diagnosis is: stroke. This means that parts of the brain are no longer supplied with blood and nerve cells die. “Time is brain” is the slogan, because the sooner the patient is treated, the greater the chance of minimizing subsequent damage. The pensioner, who had been fit up to then, is transferred to the stroke unit – the special organisational unit within a hospital that takes over the initial treatment of stroke patients.

6

people worldwide

are estimated

to die of a stroke

every minute.

2 of people who / 3

suffer a stroke live in developing

countries.

Neuroscience and Medicine (INM-3) and at the University Hospital Cologne. With TMS, specific areas of the brain can be influenced non-invasive- ly from the outside via a magnet coil (see infobox).

Grefkes‘ research and scientific commitment have already won him several prizes, including the Young Investigator Award of the Competence Network Stroke. In the competition “Germany – Land of Ideas”, his topic “Early Rehabilitation of Stroke Patients through Brain Stimulation” was distinguished as a “Selected Landmark”.

“This topic already fascinated me during my studies and has kept preying on my mind ever since. And in recent years, we have also achieved some breakthroughs,” says Grefkes. In 2007, for example, in the first major study involving stroke patients, Jülich researchers found out how the brain recovers and reorganises after a stroke. It had already been known that after a stroke, a part of the brain is no longer sufficiently supplied with blood and brain tissue dies. Depending on the se - verity of the stroke, the physical consequences

In 2014, researchers from Göttingen, together with Shinichi Furuya and Eckart Altenmüller from Hanover University of Music, tested on pianists whether and to what extent brain perform- ance can be improved with transcranial stimulation.

While untrained piano players indeed did play better after direct current stimulation, the professionals’ keystroke accuracy decreased. Obvi- ously, the performance of a brain area that has already reached its optimum cannot be improved further, the

researchers concluded, but only worsened. “Or one might have to stimulate completely different areas of the brain of professional pianists,” Prof.

Christian Grefkes points out.

Carried to excess

The mathematician Silvia Daun has specialised in biological processes. She develops models for stroke research that show how magnetic stimulation im- pacts the brain of patients.