effzett FORSCHUNGSZENTRUM JÜLICH’S MAGAZINE

Energy to go

Researchers are developing a new generation of batteries

effzett FORSCHUNGSZENTRUM JÜLICH’S MAGAZINE

SWITCH How light controls

nerve cells

SCRUTINY On the lookout for weapons-grade uranium

SENSE The colours of numbers

2-1 5

What’s that flying up there?

At first glance, it looks like a giant insect from outer space searching for food.

With one eye and eight propellers in the place of wings, it hovers above the field.

But wait! The supposed alien is only hungry for data. It’s not even able to fly by itself.

Andreas Burkart, PhD student at the Institute of Bio- and Geosciences (IBG-2), controls the futuristic flying object. The octocopter’s eye is nothing more than an objective lens;

its body, a camera. Burkart uses the camera to collect data from an altitude of about 100 metres on the vegetation in meadows and grain fields. Based on this data, he can determine the health of the plants and how ripe they are, as well as species diversity.

NE WS IN BRIEF

5

COVER STORY

Record-breaking energy storage

Being on the move demands

“energy to go”. Batteries are set to become even more powerful, more efficient, and cheaper.

8

RESE ARCH

Glowing future

Valentin Gordeliy controls nerve cells with light.

14

Unexpectedly similar

Mental illnesses share noticeable features

in the brain.

16

The small difference

What makes our world what it is?

Kálmán Szabó and Stefan Krieg are looking for the answer.

18

Nuclear detectives

They reveal what’s really produced in uranium facilities.

20

Test, test, test!

Synaesthetes connect colours with numbers.

23

Attack of the ash particles

New ceramic coatings protect aircraft turbines.

24

SECTIONS

Editorial 4

Publication details 4

What’s your research all about?

19

2.2 plus 26

Thumbs up 27

Research in a tweet

4 28

9 8 ³ 1 ⁶

Publication details

effzett Forschungszentrum Jülich’s magazine, ISSN 2364-2327

Published by: Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

Conception and editorial work: Annette Stettien, Dr. Barbara Schunk, Christian Hohlfeld, Dr. Anne Rother (responsible under German Press Law)

Authors: Marcel Bülow, Dr. Frank Frick, Christian Hohlfeld, Katja Lüers, Christoph Mann, Katharina Menne, Tobias Schlößer, Dr. Barbara Schunk, Brigitte Stahl-Busse, Annette Stettien, Ilse Trautwein, Erhard Zeiss, Peter Zekert

Translation: Language Services, Forschungszentrum Jülich

Graphics and layout: SeitenPlan GmbH, Corporate Publishing Dortmund

Images: Forschungszentrum Jülich (5, 11, 12, 17), Forschungszentrum Jülich/Ralf-Uwe Limbach (2, 3 left, top centre, 10, 15, 16, 18, 24 top), Forschungszentrum Jülich/IBS Grenoble (15 top), Forschungszentrum Jülich/Sascha Kreklau (19, 20, 22 top), © Airbus DS Geo GmbH (22 centre), alejandro dans neergaard/Shutterstock (7 right), Árni Friðriksson (3 right), Courtesy NASA/JPL Caltech (6 right), Courtesy of Diamond Light

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Contact: Corporate Communications, Tel: +49 2461 61-4661, Fax: 02461 61-4666, E-Mail: info@fz-juelich.de

Power from garden compost, sugar, or even urine? Sounds strange, but it really does work! British researchers have developed a toilet in which bacteria-driven fuel cells convert urine into energy.

A well- frequented toilet will never be dark again. What seems far-fetched will in fact improve safety in the Third World: in unlit sanitary facilities in refugee camps, attacks, particularly on women, frequently occur.

Creative approaches are also needed for the mobile world. Although your own urine will probably not charge smartphones and electric cars in future, perhaps the breathing battery will. Our author Katja Lüers is on the case and her report starting on page 8 looks at what super batteries could soon power our everyday devices.

We hope that you enjoy this issue – and if you’re reading it on your tablet, we hope your battery is full!

Your effzett editorial team

Fully charged

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They’re as impressive as fireworks in the night sky. But seeing them gives cause

for concern: fibrils, clumps of protein in the brain that are no bigger than a few micrometres in size, damage nerve cells.

They are typical of Parkinson’s disease.

Researchers from Jülich and Düsseldorf observed their growth using a

fluorescence microscope.

– IN S TITUTE O F C O MPLE X SYS TE M S –

BIOCHEMISTRY

Pretty perilous

Not only when learning but also when forgetting things, it’s important to take regular breaks. Or at least this applies to hypersynchronous nerve cells, as neuroscientists at Jülich have discovered. Using the computer, they simulated cells that send out excessive and synchronous signals. Such abnormal behaviour of brain cells occurs in people suffering from Parkinson’s or tinnitus. The cells concerned can be brought out of this synchronism

if they are stimulated with a set pattern of impulses over a lengthy period of time.

The computer simulations showed that weak impulses with practically no effect may be sufficient – but only if adequate breaks are taken between the stimulations.

– IN S TITUTE O F NE UR O S C IE N C E AND ME D I C INE –

NEUROSCIENCE

Taking a break makes

all the difference

Since January 2015, a new observation satellite has been orbiting Earth: Soil Moisture Active Passive (SMAP)

was developed by the American space agency NASA and measures soil moisture everywhere on Earth.

Jülich researchers compare the soil moisture calculated from the satellite data with their measurements at various sites. If there are deviations, NASA can check its calculations and adapt them accordingly. The mission aims to improve our understanding of the correlations be- tween water, energy and carbon fluxes, and to improve the predictive capability of weather and climate models.

– IN S TITUTE O F B I O - AND G E O S C IE N C E S –

WATER RESE ARCH

Measuring above, testing below

Jülich physicists have made further progress in utilizing graphene. This special form of carbon is being studied throughout the world because graphene is harder than diamond, tougher than steel, and more conductive than silicon. However, before it can be implemented in applica- tions, a supporting material or substrate is essential for the ultrathin material. But this can alter the electronic properties of graphene. Thanks to Jülich researchers, the strength of this interaction can now be determined using a simple criterion.

The decisive parameter here is the atomic distance between the graphene layer and the substrate. Equipped with this knowledge, new substrates can be sought and evaluated.

– PE TE R G RÜNBE R G IN S TITUTE –

NANOMATERIALS

Support

partners . . . 8

… one thought: protecting the environment while on the go. This is what Forschungszentrum Jülich and seven other regional partner enterprises are working on

in the project Mobil.Pro.Fit. The nationwide initiative provides advice for enterprises and organizations on what improvements could be made in areas such as business trips, company cars, and commuting to work.

New approaches could also cut costs. Mobil.Pro.Fit is part of Germany’s National Climate Initiative.

– SUS TAINABLE CAMPUS –

A rare side-effect of the painkiller Ibuprofen is gastrointestinal bleeding. Researchers

from Jülich and Munich have identified a possible explanation for this. In a model

system, they used neutron scattering to show that high doses of the drug attack the cell membranes of the stomach walls.

Although these concentrations considerably exceeded normal doses, the researchers believe that such high concentrations are possible for brief periods in localized areas.

– JÜLI C H C E NTR E F O R NE UTR O N S C IE N C E –

In the Brazilian city of Goiânia, the research project PURESBio began at the end of January.

Plant researchers from Jülich are coordinating the German-

Brazilian cooperation. The project aims to sustainably use organic waste from crop cultivation and biogas produc-

tion – and ideally, this should happen in a regional, closed

nutrient cycle.

SUSTAINABLE CYCLE

Researchers from Jülich, Dresden, and Strasbourg have succeeded in electrically reading

out the orientation of magnetic vortices in tiny iron-silver discs.

They made use of characteristic microwaves which are emitted by two nanodiscs placed on top of each other. These devices

could function as space-saving and energy-efficient data

storage in future.

ORIENTATION READ - OUT

The German Federal Ministry of Education and Research (BMBF) will provide € 6.5 million in funding

for five Jülich projects aiming to develop materials for effective and

affordable energy storage. Such storage is important for the trans- formation of the energy sector – the

“Energiewende” – as it will counter- balance fluctuations in the power

grid caused by the generation of power from wind and the sun.

RESEARCH FOR THE

“ENERGIEWENDE”

Methanol is toxic and highly flammable, but is still high on the agenda – as a fuel as well as for the production of chemical substances such as acetic acid.

In future, the alcohol may also be utilized in biotechnology, providing nutrition for bacteria that produce important

substances like amino acids. At the moment, sugar is mainly used as a nutrient. Scientists at Jülich have modified the bacterial strain Corynebacterium glutamicum to enable it to utilize methanol, which in turn can be produced

from renewable raw materials. Before its industrial application, however, the conversion of the alcohol by

the bacteria must be improved.

– IN S TITUTE O F B I O - AND G E O S C IE N C E S –

BIOTECHNOLOGY

Alcohol instead of sugar

Attacks on

cell walls

Record-breaking energy storage

6

8 7

9

10 11

12

13

Batteries in everyday life 1 Laptop 2 Mobile phone 3 Chainsaw

4 Pedelec 5 Electric car 6 Hearing aid 7 Power wheelchair 8 Solar-powered parking meter

9 MP3 player 10 Radio device 11 Buffer storage for photovoltaic systems 12 Alarm system

13 Battery for power supply in a passenger plane 14 Space satellite

Record-breaking energy storage

1

3 2

4

5

Whether it’s a smartphone, cordless screwdriver, or electric car – the mobile world relies on the

lithium-ion battery. But alternatives are also being explored for “energy to go”. To date, although

many options are conceivable, they all have a

long way to go before reaching market maturity.

today, is more powerful than ever before. “No other rechargeable energy storage system can compete with it at the moment,” says the physi- cist. However, today’s smartphones are equipped with countless power-hungry functions. People don’t buy a mobile phone simply to make tele- phone calls any more; they want to be able to use it to film, take photos, and play games.

“The development of lithium-ion technology is without doubt a success story. But compared to the development of added features for mobile phones and cars, it’s a slow process,” says Eichel.

And the ultimate battery that can be used in all electronic devices will continue to be a pipe dream. “It’s just not viable: if we compare a car battery and a mobile phone battery, we quickly realize that each rechargeable battery must be optimized for the intended application in order to become a record breaker in its own discipline,”

says Eichel.

Car batteries, for example, have to provide a very high current at very different temperatures;

otherwise, the engine won’t start. Mobile phones don’t need these high current densities. Instead,

T

rouble with your mobile

phone battery? It’s a scenario most of us are familiar with.

Not too long ago, I was on the train, and once again, I had just sat down and started to read my emails when my smartphone simply turned itself off – battery dead. What I didn’t know was that my daughter had secretly used my phone that morning to send voice messages to her friends and to take countless photos of her sisters. The charger cable was at home on the kitchen table.

It’s at times like this that I often wonder – even as a scientist – how is it that man can fly to the moon, and yet the battery in my mobile can’t even outlast my daughter and a train journey?

And where are these super-duper batteries that everyone is always talking about? A few years ago, it felt like I could use my mobile to make calls for hours on end, but today I have the feel- ing that the newer the phone is, the faster the battery dies.

Jülich battery researcher Rüdiger Eichel grins to himself when he hears stories like this: “Such impressions are misleading.” The lithium-ion battery, which is standard in all mobile devices Prof. Rüdiger Eichel

is head of the Institute of Energy and Climate Research – Fundamentals of Electrochemistry (IEK-9) at Forschungszentrum Jülich.

Here, the physicist and his team are investigating basic concepts for future energy storage systems and energy converters. Together with Karlsruhe nano scientist Prof. Horst Hahn (KIT), Rüdiger Eichel, as spokes- person, coordinates the battery research of all Helmholtz centres on the topic of “Electrochemical storage” in the new Helm- holtz programme “Storage and cross-linked infrastruc- tures” (SVI).

velopment of lithium-ion technology. Not only are new materials required for the positive and neg- ative poles but new electrolytes are also essen- tial – and this is where the priority of Helmholtz Institute Münster (HI MS) lies. The electrolyte is the medium that is responsible for transporting the ions inside the battery between the two elec- trodes, namely the anode and cathode.

In conventional batteries like the lead-acid starter battery, the configuration is not very flexible:

two lead plates function as electrodes and liquid sulfuric acid as the electrolyte. These batteries provided submarines with energy during the First World War and are a standard part of every car with an internal combustion engine today.

Lithium-ion technology, in contrast, provides researchers with great flexibility: the electrolyte can be liquid, solid, or ceramic. New materials are also constantly being tested for use as electrode coatings in order to find an optimal composition for the electrochemical cell. “This potential mixture of materials is what makes the research so exciting, and the results so difficult to predict,”

says Winter.

Most of the standard batteries available commer- cially today contain liquid electrolytes, some of which are toxic and highly flammable. A team of scientists at Forschungszentrum Jülich headed by Prof. Olivier Guillon recently developed a ceramic electrolyte. Replacing liquid electrolytes with a solid reduces the risk of leaks, overheating, people want to be able to use the device for as

long as possible. These are very distinct chal- lenges and battery researchers like Eichel are working on solutions. In other words, instead of one super battery, several different types and systems will emerge, with one thing in common:

they will all be cheap, durable, efficient, safe, and powerful.

PUBESCENT TECHNOLOGY

Battery researchers are further developing rechargeable batteries from two angles. The first involves optimizing lithium-ion technology. “In terms of energy content, it’s just hit puberty, and is a long way from maturity,” says Münster bat- tery expert Martin Winter. The second approach involves completely new solutions that may one day replace “grown-up” lithium-ion technology in selected applications. “After all, it too will reach its limits eventually,” Eichel is convinced.

Many researchers believe that the range of an electric car with a lithium-ion battery will never compete with the range of a car run on petrol.

Energy-hungry smartphones are also crying out for new solutions. “These completely new types of battery will ensure an economically and ecolog- ically sustainable supply of energy and storage in the long term,” says Winter. But it will take several years until we reach this stage.

Winter is confident that battery research will be driven over the next 15 years by the further de-

Prof. Martin Winter is founder and scientific head of the battery research centre MEET. MEET stands for Münster Electro chemical Energy Technology. On 1 January, the chemist became director of the new Helmholtz Institute Münster (HI MS). HI MS is dedicated to electrolyte research for batteries and pools the expertise of Forschungs- zentrum Jülich, RWTH Aachen University, and the University of Münster.

The most common battery systems

ZINC-CARBON ALKALINE-

MANGANESE SILVER OXIDE LITHIUM NICKEL-

METAL HYDRIDE NICKEL-

CADMIUM LITHIUM-ION

Voltage 1.5 V 1.5 V 1.55 V 3 V 1.2 V 1.2 V 3.6 V

Negative pole

anode Zinc Zinc Zinc Lithium Water-retaining

metal alloy Cadmium Lithium-cobalt

compounds Positive pole

cathode Manganese dioxide Manganese dioxide Silver oxide Manganese dioxide Nickel hydroxide Nickel hydroxide Graphite Advan-

tages (+) and disadvan- tages (-)

+ Cheap production - Limited capacity

and power

+ High performance + Good leak

resistance + Long shelf life

+ High energy density + Long lifetime - High production

costs

+ Low self-discharge + High energy

density + Long shelf life + Not sensitive to

temperature - High production

costs

+ Cadmium-free + High energy density + High capacity - Higher self-

discharge than lithium-ion batteries - Lazy battery effect

+ Very durable + Fast recharging + Cold-resistant to

-15 °C - Harmful to the

environment - Low energy

density - Memory effect

+ No memory effect + Low self-discharge + High energy

density + Long lifetime - Sensitive to full

discharging and overcharging

Use • Alarm clocks

• TV remote controls

• Pocket calculators

• MP3 players

• Torches

• Smoke alarms

• Blood pressure monitors

• Watches

• Medical instruments (e.g. insulin pen systems)

• Digital cameras

• Smart cards

• Alarm and tracking systems

• Toys

• Electrical toothbrushes

• Cordless telephones

• E-cars and e-bikes

• Emergency and alarm systems

• Medical equipment

• Tools

• Mobile phones

• Laptops

• MP3 players

• E-cars

• Tools Source: “Die Welt der Batterien”, published by: Stiftung gemeinsames Rücknahmesystem Batterien, 2012

Cathode (copper)

Anode (zinc) Electrolyte

Electrolyte Porous partition

Cu

²⁺

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

Zn

²⁺

Zn

²⁺

Cu Zn

flammability, and toxicity, and also permits a high energy density. Energy density is the most important parameter for comparing different bat- tery systems. It is the amount of energy per unit volume or mass that can be stored in the battery.

The larger the energy density, the smaller and lighter the battery for the same capacity. “The Jülich solid-state battery is still a long way from market maturity. We’re only at the basic research stage,” says Eichel.

VAST AREA – GREAT POTENTIAL

This basic research also involves searching for alternatives to the lithium-ion battery. “The field beyond tried-and-tested technology is still largely unexplored and is simply waiting to be discov- ered,” says Eichel. And that’s what he finds so fas- cinating and where he believes opportunities lie.

“German scientists are in an excellent position to make their mark in this field. We don’t have to catch up with anyone!”

The present spectrum of super batteries ranges from metal-air, lithium-sulfur, and magnesium-ion batteries to rechargeable “green batteries” based on organic materials – a breakthrough for com- mercialization has yet to occur.

At Jülich, one battery type that researchers are concentrating on is the metal-air battery. These

“breathing” batteries have a huge weight advan- tage over other types of batteries because they don’t have to store one of their main components:

oxygen. “We are testing different concepts:

from iron-air and aluminium-air to zinc-air and silicon-air batteries,” says Eichel. Theoretically, metal-air batteries promise an energy density that is around the same magnitude as that of petrol. However, the fact that the electrochemical reactions, which severely limit the charge/dis- charge cycle, are not yet fully understood is prob- On a laboratory scale,

the solid-state battery developed by scientists at Jülich performs astonish- ingly well. Its electrolyte is not a liquid but a special ceramic. “This reduces the risk of leaks, overheating, flammability, and toxicity,”

says Prof. Olivier Guillon, Institute of Energy and Cli- mate Research – Materials Synthesis and Processing (IEK-1). He and his team unveiled the new cell in spring 2015.

Normally, a liquid electro- lyte transports lithium ions during discharging from the anode to the cathode and simultaneously electrically isolates the two poles.

A solid can also fulfil this function. Suitable materials have gaps in their atomic lattice structure. Lithium ions (blue) can occupy these empty sites and move through the solid by

“jumping” from one site to the other.

» The field beyond tried-and-tested

technology is still largely unexplored and is simply waiting to be discovered. «

The Jülich battery

Solid instead of liquid

lematic. In laboratory tests, an iron-air battery, for example, can only be recharged between ten and twenty times at the moment – at least 1,000 cycles are needed for commercial applications.

Despite this, Eichel still considers this concept to be the most promising. Martin Winter is more cautious: “It will take decades before a break- through is achieved.” And this applies to the whole range of super batteries.

Both researchers agree that battery research as a multidisciplinary field has a long way to go.

Today’s lithium-ion batteries can store three times as much energy per unit mass than the first commercial versions marketed by Sony in 1991.

“But this took us 20 years,” says Winter.

In other words, I have to be patient. But there is hope that one day my smartphone will survive the secret “attacks” of my future grandchildren and that I will be able to use it sitting on the train afterwards – its battery fully charged while trav- elling from the north to the south of Germany.

K ATJA LÜE R S

Cathode (copper)

Anode (zinc) Electrolyte

Electrolyte Porous partition

Cu

²⁺

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

e

^-

Zn

²⁺

Zn

²⁺

Cu Zn

Until the mid-1980s, battery research and production was a source of pride for the German chemicals industry and electrical engineering. Then, there was a sharp break:

consumer electronics moved lock, stock, and barrel to Asia, and with it battery know-how.

In the Federal Republic of Germany, things were quiet for almost 30 years. But now, this period of stagnation is over – thanks to the “Energiewende” and the propagation of electromobility.

“One reason for this is that new areas of application have opened up for batteries:

they aren’t just interesting for mobile devices such as smartphones, tablets, and laptops, but also for electric cars and hybrid vehicles. The increasing electrification of drives will have a considerable impact over the next few decades on the market for batteries and components. Large batter- ies are even being discussed as stationary energy storage systems,” explains Martin Winter.

For Germany, this is an important develop- ment – after all, both the energy sector and automotive industry are cornerstones of the German economy. The Federal Ministry of Education and Research (BMBF) is also prioritizing battery research for electric vehicles. Hopefully, the best batteries will come from Germany very soon. “We want to be global leaders in innovation,” says Feder- al Research Minister Johanna Wanka. BMBF has been funding battery research since 2007. One example is the innovation alliance

“Lithium-ion battery 2015”, which has been granted funding worth € 60 million.

“German battery research is once again back on top. In some areas, we are already on par with Asia as a global player,” summarizes Winter. His colleague at Jülich confirms this.

“We are researching on an equal footing.”

New projects at Jülich within the BMBF programme on materials research for the

“Energiewende”:

AlSiBat Further development and testing of aluminium-air and silicon-air batteries

• Duration: until mid-2017

• Funding: € 2.3 million, of which

€ 0.7 million is for Jülich

DESIREE Development of cathode materials for safe and more powerful next-generation lithium-ion batteries

• Duration: until mid-2017

• Funding: € 3.4 million, of which

€ 1.3 million is for Jülich

SABLE Combining imaging techniques with spectroscopic and microscopic techniques to investigate processes in electrochemical devices right down to the nanoscale

• Duration: until end 2015

• Funding: € 2.9 million

K ATJA LÜE R S

Research on an equal footing

How a battery works

A battery converts chemical energy into electrical energy, as shown here using a zinc-copper battery as an example. When a battery discharges, zinc atoms (Zn) release electrons (e^-) to the anode (negative pole).

In the process, these atoms become zinc ions (Zn²⁺). The electrons flow through an electrical conductor as current to the cathode, the positive pole. In this way, they can power a torch, as shown here. At the positive pole, copper ions (Cu²⁺) take up the electrons and become copper (Cu). Finally, the charged particles (ions) flow from the electrolyte back to the negative pole.

“It was immediately clear that this pump would keep us occupied,” says Prof. Valentin Gordeliy. “Such light-driven proteins have become enormously important over the last few years: they have evolved into a tool for a whole new field of research – optogenetics,” says the researcher from Jülich’s In- stitute of Complex Systems (ICS-6). In optogenetics, scientists implant such proteins into the membrane of nerve cells, for example. When ion pumps and channels – depending on ex- posure to light – transport particles with different charges into the cell, a neuron can be activated and deactivated again.

A new method is throwing light on thinking: optogenetics utilizes special proteins to control nerve cells in the brain with light impulses.

A structural biologist at Jülich has invented another tool for this.

Glowing future

When biologists fish a new bacterium out of the ocean, it rarely causes a stir outside the specialist community. This was no different when the marine bacterium Krokinobacter eikastus was discovered in 2006. But a few years later, it electrified scientists around the world: in 2013, a tiny biological pump with unique properties was discovered in its cell membrane.

Composed of a single protein molecule, this pump transports charged sodium particles – ions – out of the cell, and it does so using solar energy.

The proteins thus function as molecular switches. “By switch- ing nerve cells on and off as desired, brain researchers can explore the interaction between neural microcircuits in more detail than ever before,” says Gordeliy.

However, the optogenetic toolbox is still quite modest as only a few membrane proteins have been identified as useful so far. And these proteins are only permeable to certain ions. A new addition like KR2, as the new bacteria pump is known, was therefore most welcome. However, decisive information necessary for its targeted use is still lacking: “A new protein molecule is a bit like an unknown machine – you can see what it does but initially not how it does it,” explains the researcher.

To understand the exact mechanisms, the basic structure must be known – and that of KR2 is extremely complex. It contains more than 4,400 individual atoms – and the position of every single one must be determined in order to obtain the structure as a whole.

Deciphering such structures is the speciality of Valentin Gordeliy and his team. In addition to the team in Jülich, the structural biology expert heads a research group in Greno- ble and cooperates closely with his former working group in Moscow. “Despite the distance between us, all team members are continuously in contact and we work hand in hand,” says Gordeliy.

With the aid of X-ray crystallography, Gordeliy and his colleagues Vitaliy Schevchenko, Ivan Gushchin, and Vitaliy Polovinkin gained insights into the structure of KR2.

“In the high-resolution images, we noticed an unusual formation at the exact spot where ions are taken up inside the cell,” says Gordeliy. The researchers presume that this is the location of the pump’s filter, which only allows one type of ion past.

CUSTOMIZED PUMPS

“We speculated that we would be able to create other light-driven pumps with different properties by manipulating this filter element,” says the scientist, looking back. In the laboratory at Jülich, they therefore replaced certain amino acids with mutations and found that KR2 did indeed transform into a pump for potassium ions. They confirmed their results in joint experiments with Prof. Ernst Bamberg at the Max Planck Institute of Biophysics in Frankfurt, one of the fathers of optogenetics.

This new pump is even more interesting for optogenetic appli- cations than the original sodium pump because potassium is found some ten times more frequently in nerve cells. On top of this, under natural conditions, once potassium ions have been transported out of the cell, firing neurons return to a state of rest. The new KR2 variant could be used to control this process with light, creating an optogenetic potassium pump that would function as a semi-natural and hopefully particularly effective off-switch for nerve cells.

While some of the groups are now working on integrating the potassium variant of KR2 into cells, Gordeliy is already planning the next adaptation of the molecule. Customized pumps for calcium ions and other elements are the target. In addition, the researchers are investigating the structures of other light-activated membrane proteins. Step by step, the optogenetic toolbox is being expanded. And Jülich researchers are contributing to this.

PE TE R Z E KE R T

International network:

Prof. Valentin Gordeliy investigates the structure of proteins at Jülich, Grenoble, and Moscow.

To decipher the structure of proteins using X-ray diffraction, the mole- cules must be present as crystals, as shown here.

Working together with researchers at Stanford University in California, Simon Eickhoff collated and evaluated the results of 193 such studies in a meta-analysis (see info box).

This analysis comprised data from more than 7,300 patients suffering from various illnesses including anxiety disorders, depression, or schizo phrenia, as well as data from around 8,500 healthy individuals.

The result is surprising. “As different as the symptoms of these mental illnesses are, there was one common characteristic in the brains of those suffering from the disorders: regardless of the illness, we found less grey matter in certain regions of the brain than in healthy individuals,”

says the psychiatrist.

The areas of the brain involved are the dorsal anterior cingulate cortex as well as the right and left sides of the anterior insular cortex.

These regions mediate attention control, enabling us to concentrate on certain tasks and ignore distractions such as noises or other stimuli – for example while solving a mathematical problem or recalling our last summer holiday.

Whether the decreased cerebral matter in patients is the cause or result of the illnesses is not yet clear. “It’s the age-old problem of what came first, the chicken or the egg,” says Simon Eickhoff.

The floor number lights up; the bell rings. Anne*

concentrates on breathing deeply. Otherwise she will begin to sweat, her heart will pound, and panic will set in. Some days, she prefers to take the stairs straight up to her office on the fifth floor. For the last few months, Anne has been seeing a psychiatrist to try and control her panic attacks. Max* is also a regular patient. The biomedical researcher finds the severe fatigue that hits him during a bout of depression the most difficult thing to deal with. Sometimes, he can’t get out of bed for days on end.

THE TIP OF THE ICEBERG

“Mental illnesses such as anxiety disorders or depression give rise to very different symptoms, but a pounding heart or severe fatigue are just the tip of the iceberg,” says Simon Eickhoff. The brain researcher knows that a large part of what causes the illnesses is hidden below the surface, like an iceberg – but instead of being hidden under the sea, it’s hidden behind our foreheads, deep inside our brains.

Throughout the world, scientists are researching what happens in our heads when we suffer from extreme forms of anxiety or depression. In recent years, imaging techniques such as magnetic reso- nance imaging (MRI) have provided insights into the human control centre. Numerous studies have been published which use this method to analyse the structure and functional processes within our brains.

Unexpectedly similar

Anne is filled with panic at the thought of using the elevator;

Max is so tired that he can’t get out of bed for days.

“Anxiety disorder” and “depression” are the diagnoses.

Despite their differences, the two mental illnesses share similarities in the brain.

The neuropsycho logist and brain researcher Prof. Simon Eickhoff works at both For- schungszentrum Jülich and Heinrich-Heine University Düsseldorf.

* name changed by the editors

THOUSANDS OF DATA SETS

But what impact will the results have on routine hospital practice? In the near future, not much.

“The results of the meta-analysis don’t allow us to say anything about individual patients. They are just mean values based on several thousand data sets,” Eickhoff emphasizes. He goes on to say that the diagnosis of many illnesses can be narrowed down today in the usual patient/doctor consultations. Here, the symptoms are the focus.

Often, Eickhoff continues, additional tests or organ examinations are then requested to rule out physical illnesses.

Eickhoff believes that future research work must concentrate on establishing whether the shared biological characteristics are due to similarities between the various illnesses and if this could be used as a starting point for similar therapies. At the moment, imaging techniques are not a stand-

ard method of examining patients – not least because of the high costs involved. In unclear cases or in the case of progressive illnesses, such as Parkinson’s or schizophrenia, Eickhoff believes that several examinations over a longer period of time would be beneficial.

This could also help Max. His acute depres- sive phases can usually be treated effectively.

However, if research continues to make progress, it may be possible in a few years to recognize certain changes in the brain, and thus determine how high the risk of another bout of depression actually is.

IL S E TR AUT WE IN

What is a meta-analysis?

In a meta-analysis, scientists use a computer to evaluate the results of numerous research studies.

The results of a meta-analy- sis are more robust than the results of individual studies:

as a very large amount of patient data is taken into account, a meta-analysis can determine whether a distinctive feature occurs with a disproportionate frequency or whether it is simply a one-off effect.

Simon Eickhoff from Jülich analysed data from various imaging studies of the brain using the special- ized software ALE (short for activation likelihood estimation), which he also helped to develop as part of his doctoral degree. The software helps compare different images and filters out similarities.

193 studies on mental illnesses were analysed by

the researchers.

Left hemisphere

Right hemisphere

EXECUTIVE FUNCTIONS

Whether it’s depression or an anxiety disorder: the meta-analysis shows that patients with a mental illness have less grey matter in three brain regions than healthy people. These areas are active when we adapt our behaviour to suit our environment.

calculated and experimental values is within a permissible margin of error. This shows that the theoretical assumptions of the calculation were correct,” says Prof. Kálmán Szabó from the Jülich Supercomputing Centre. Both Szabó and his colleague Dr. Stefan Krieg are members of the international team of scientists from Germany, France, and Hungary that developed and per- formed the simulation.

HUGE COMPUTATIONAL EFFORT

“In the past, we didn’t have the methods or the necessary high-performance computers to deter- mine this tiny difference with such precision,”

says Szabó. The cost of computation is enormous:

diverse interactions as well as the masses of the elementary particles which make up the neutron and the proton all have to be incorporated.

“The latest supercomputer generation and the improved simulation techniques we developed are what made it possible to incorporate all theoretically predicted effects,” says the Jülich researcher.

Nobel laureate in physics Frank Wilczek is ex- tremely optimistic about the new simulation tool:

“More accurate modelling of supernova explo- sions and of rare objects like neutron stars are conceivable. The dream of a more refined nuclear chemistry could be within our grasp, for example improved energy storage and ultrahigh-energy lasers.” Szabó also anticipates new insights: “My aim is to apply the more precise methods to find indications of a new physics beyond the standard model; indications that the currently accepted theories are insufficient to fully describe our universe.”

K ATHAR INA ME NNE

Two years: that’s how long it took the Jülich supercomputers JUQUEEN and JUROPA to calculate that the neutron is just 0.14 % heavier than the proton – a tiny difference of exactly 2.3∙10^-30 kg. An extremely small but decisive difference: the stability of atoms and the distribu- tion of the chemical elements as we know them all depend on it. This is what the standard model of particle physics says. Another mass difference would probably lead to a completely different universe: more neutrons, less hydrogen, and a totally different chemical composition of matter would result.

Experiments around 80 years ago revealed the existence of this tiny difference. The fact that it can now be calculated from theoretical models is considered a milestone by many physicists.

“Our simulation is further confirmation of the standard model. The agreement between the

The small difference

Our universe exists because neutrons are slightly heavier than protons. Researchers recently succeeded

in calculating this minute difference in mass.

Patience pays off: Prof. Kálmán Szabó (left) and Dr. Stefan Krieg waited two years for supercomputers like JUQUEEN to perform their calculations.

0.14 percent is how much heavier the neutron is

than the proton.

What’s your research all about, Ms Vossel?

“Our sense organs are continuously sending signals to our brains. But we don’t pay equal attention to all of them; some remain fuzzy. How do our brains know which signals are important at any given moment and which brain regions are involved?

That’s what I want to find out! If we understand this in healthy individuals, then we will be able to explain perception disorders in patients who have suffered a stroke

for example, and help them to regain abilities that they have lost.”

Dr. Simone Vossel, BMBF group leader

at the Institute of Neuroscience and Medicine – Cognitive Neuroscience

subsequently tamper with the samples. Nuclear sinners who have been caught out would other- wise seize the opportunity to question the result and claim that they are victims of a conspiracy.

The inspectors do not need to take any safety precautions against the radioactivity. “The wipe does not pose a health hazard – the amounts of radioactive material on it are extremely small,”

the Jülich researcher says.

INTERNATIONALLY ACTIVE

The sealed box is sent to the central laboratory of the IAEA in Vienna – to the Office of Safeguards Analytical Services. Here, the wipes received are tested for radioactive substances – initially without even removing them from the plastic bag.

Then, the IAEA experts decide how their detec- tive work will proceed. If the initial test indicates nuclear material in an unusual composition, then comprehensive, in-depth analyses are requested in order to expose any possible illegal activities.

As numerous samples have to be tested, many of them are sent to one of the twelve external labo- ratories who belong to the global IAEA network.

Such a network has the advantage that laborato- ries in different countries can verify the result of an analysis if the plant operator involved or the respective government calls it into question.

The laboratories in the network consistently work on options of wringing even more information out of the swipe samples. “Normally, the material of the sample, which comes from thousands of particles on the wipe, is analysed as a whole.

Over the last number of years, laboratories in the network have been refining analysis methods mainly for individual uranium- or plutonium- containing particles in the swipe sample,” says For most parents of babies and toddlers, baby

wipes are indispensable – when changing a nappy or quickly cleaning little hands. The wipe that Dr.

Martin Dürr is holding in his hand looks just like these gentle everyday aids. But he’s not standing at the nappy changing table; he’s in one of the meeting rooms used by the International Safe- guards group at Jülich’s Institute of Energy and Climate Research (IEK-6). “This is an important utensil for unveiling states that do not respect the Treaty on the Non-Proliferation of Nuclear Weap- ons,” says Dürr. Currently, 191 states are parties to this treaty and have committed themselves to the non-proliferation of nuclear weapons. India, Pakistan, Israel, and Southern Sudan have not signed the treaty and North Korea has withdrawn from it.

IAEA inspectors use these swipe samples in nuclear facilities. With the cloth, they simply wipe over twisting pipes or the shoes of employ- ees. That these are actually cleaned in the process is not important. What is important is what the wipe collects: in addition to normal dust, this could include the tiniest trace amounts of urani- um. “Such trace amounts tell us whether an oper- ator really does use their facility for the declared purpose of producing uranium for power plants or whether they covertly use it to produce other, weapons-grade uranium,” says Dürr.

The inspectors can’t perform the complicated trace analysis on site, so they place the wipe in a small plastic bag – as carefully as the forensic police force would package a textile fibre or a shard found at the scene of an investigation. The bag is placed in a container, which the inspector then seals. This is done to ensure that nobody can

Nuclear detectives

One of the responsibilities of the International Atomic Energy Agency (IAEA) is to track down states that are covertly

producing or proliferating nuclear material for weapons.

A team at Jülich is supporting these efforts.

»Trace amounts reveal whether

an operator misuses his plant and

produces weapons-grade

uranium. «

Dr. Martin Dürr

Dürr’s boss Dr. Irmgard Niemeyer. She is in close contact with the IAEA experts and is the only German member of the Standing Advisory Group on Safeguards Implementation, which advises the IAEA Director General Yukiya Amano.

Analysing individual particles is particularly challenging. The particles are no bigger than a thousandth of a millimetre, and the method must also be capable of accurately detecting minute amounts. When the wipe tests are used, a lot of normal dust and dirt is also collected, making this procedure a bit like looking for a needle in a haystack. But this procedure provides the IAEA nuclear detectives with useful information, allowing them to determine the ratio of various heavy uranium atoms – uranium isotopes – to each other in individual particles. Based on this, they can ascertain whether the uranium in a plant has been more highly enriched with highly fissile isotopes than specified. They can also

confirm whether a different uranium material than claimed has been used in the plant from the outset.

QUALITY ASSURANCE

For reliable results, it is important that the laboratories in the network have access to reference materials. What these materials are composed of and how they are produced is known. Such reference materials are Martin Dürr’s speciality. Together with colleagues and in cooperation with the IAEA, he has implement- ed a procedure at Jülich that enables uranium reference particles to be produced: all particles in a sample have identical dimensions and contain the same amount of uranium with the same composition of isotopes. These reference particles are used by the network’s nuclear detectives to test their detection methods and to calibrate their analytical devices. The Jülich particles can also be used to verify the quality of a laboratory in the

Under the scrutiny of the International Atomic Energy Agency (IAEA): the heavy- water reactor IR-40 near Arak in Iran. The IAEA is concerned that weapons-grade plutoni- um is produced here.

Satellite images provide important information on nuclear plants. Dr. Irmgard Niemeyer develops computer programs for automatic image processing.

It’s not only on-site inspectors who keep an eye on the activities in a nuclear facility – so too do satellites. “The IAEA uses satellite images from commercial providers,” says Dr. Irmgard Niemeyer, head of the International Safeguards group at Jülich. Her team assists the IAEA by developing computer programs that automatically process and analyse satellite images.

“In contrast to humans, computers pay equal attention to all parts of an image. And they can determine the size of the facilities and distances much faster, more accurately, and more reliably,” says Niemeyer’s colleague Dr. Clemens Listner. Satellites can

sometimes also provide image data on the surface temperatures of a facility and thus on its operating status – data that computers can process and present in a form that humans can understand.

In addition, the programs use statistical methods to show when and how a facility has changed over time – and not just whether the vegetation around the facility turns green in spring. “Using satellite images of a uranium enrichment facility in Iran, for example, we could clearly monitor how halls for the necessary centrifuges were first built and then cam- ouflaged, preventing them from being directly recognized from the air,” says Niemeyer.

The eye in the sky

network. The results of a laboratory’s analysis can simply be compared to the product specifications from Jülich.

“Made in Jülich” also applies to another utensil that Martin Dürr presents after laying the wipe tests aside: a seal. This seal is very different to that used by investigators in television crime series to prevent entry to apartments and contamination of crime scenes. Instead, this is a small electronic device. “This is what the device looked like when it was developed in our workshops back in the 1970s. Today, its successors are the gold stand- ard at the IAEA,” he says. The seal has a remote readout function that allows inspectors to check via the Internet at any time whether a container has been opened – an indication that somebody wanted access the sensitive material inside. This is where securing the evidence would take over from the nuclear detectives!

FR ANK FR I C K

GRAB YOUR PENCIL ...

Psychology has some nice and simple tests. For example, this one:

Please pick up your pencil and without thinking about it divide the line in half:

Dividing a line* in half is a routine test for patients who have suffered a stroke. It helps to ascertain whether the patient is suffering from the neglect syndrome. In such cases, patients only consciously perceive one half of the line and divide the line too far to the right, as shown here.

And then there are tests that indicate how healthy people “tick”.

Please pick up your pencil and without thinking about it divide the row in half:

222222222222222222222222222222222222222

The overwhelming majority divide this row of numbers far left of the centre. Use a ruler to measure whether you have too!

ONE AFTER THE OTHER, PLEASE

Prof. Peter H. Weiss-Blankenhorn, neuroscien- tist at Forschungszentrum Jülich, explains why:

“Most people use the right half of their brain more than the left when processing spatial in- formation, which means that their perception of objects in their left field of view is much stronger.

This is why healthy individuals often divide the simple, black line left of the centre. This phenom- enon is known as pseudoneglect.”

The effect is more pronounced for the row of numbers. People who write from left to right often perceive the numbers as being arranged in ascending order from left to right.

A line of 2s is therefore divided even farther left of the centre because people focus on where 2 should normally appear in a row of numbers. The person being tested neglects the right-hand side of the row of numbers and divides it where they suppose the centre to be. If greater numbers, such as 9s, are used, they divide the line more central- ly or right of the centre.

Jülich scientist Eva Nießen wants to know how synaesthetes deal with the following task:

Please pick up your pencil and without thinking about it divide the line in half:

“Synaesthetes have an added aptitude,” she says.

“Different sensory impressions are connected to each other. Some synaesthetes perceive numbers or words in a certain colour, others can taste or feel sounds.” For the study, Eva Nießen and her team selected test subjects who perceive numbers in colour and a reference group without this asso- ciation. None of the test subjects had ever heard of the test requiring them to divide a line in half.

In completing the task, all synaesthetes divided the line, the colour of which they associate with a small number, left of the centre. And they did so despite all test subjects stating that they perceive colour as colour and not as a number.

Non-synaesthetes sometimes divided the line in the centre, sometimes to the left, and sometimes even to the right.

For Eva Nießen, the result is clear: “We’re convinced that synaesthesia functions in two directions even if synaesthetes aren’t consciously aware of this.”

BR I G IT TE S TAHL - BUS S E

Test, test, test!

2

4 ⁵ ₈

9

3 ⁷

1 ⁶

* Lines are longer in the real test.

Each synaesthete has their own individual colour code that remains the same throughout their life.

Synaesthetes associate different impressions with each other, for example numbers with colours or taste with shape.

But does this also work the other way around?

Are colours codes for numbers?

of robust data on what concentrations of ash particles and exposure times cause damage to aircraft engines.

Physicists Prof. Robert Vaßen and Dr. Daniel Emil Mack are working with their colleagues at the Institute of Energy and Climate Research (IEK-1) to determine how hazardous “silicates” such as sand or volcanic ash really are for flight safety – and how turbines can be better protected with new materials. “We have known for a long time that silicates are not good for aircraft turbines.

However, most experts believed the hazards to be manageable until the first Iraq War at the begin- ning of the 1990s,” says Mack. “The desert sand corroded the engines of the fighter jets to a much greater extent than expected.”

The reason for this, according to the experts, was actually technological progress in aviation. In the years preceding the war, the engineers had in- creased the temperature at which fuel enters the turbines of combat aircraft to more than 1,250 °C.

This improves the efficiency with which the combustion energy of the gas is converted into mechanical energy – but it also causes silicates like sand that are sucked into the engine during flights to melt. And this triggers a chemical attack on the turbines. “Their metallic components are protected against heat by a ceramic coating. But when the grains of sand melt, they infiltrate these coatings like water seeping into a sponge.” The result: the sand particles attack the ceramic coat- ings, counteracting their protective effect or even corroding them completely. This is a problem that civil aviation also has to deal with nowadays. To- day’s commercial airliners also run their engines’

turbines at temperatures above 1,250 °C.

At IEK-1, the scientists are working on this prob- lem with a test stand that is unique in Europe.

“We use it to realistically reproduce how molten silicates infiltrate the turbines,” says Mack. “We take a specimen with a diameter of three centi- metres, which is made of a heat-resistant metal alloy protected by ceramic layers just like the parts of a turbine. We heat the ceramic surface to more than 1,250 °C while the metal is cooled.

Steam and ash were sputtered into the atmos- phere and dispersed over kilometres. Blazing red lava shot out of the two-kilometre hole in the mountain with the unpronounceable name.

The eruption of Eyjafjallajökull in Iceland (pronounced: [ e^Ija fjatla jœ k^Ytl ]) is not just something that pilots from various airlines can remember. At the time, in spring 2010, the volcano caused enormous disruption to air travel across northern and central Europe because of a huge ash cloud that spread out over hundreds of kilometres towards the south.

European aviation authorities decided not to take any risks and banned air travel in these areas.

Later, criticism was voiced as to whether this was really necessary; the flight ban cost the economy

€ 150 million per day. Whether it was necessary or not is still difficult to say today. There is a lack

Attack of

the ash particles

What concentrations of volcanic ash or sand pose a hazard to flight safety? Researchers at Jülich are investigating this question with a test stand that is unique in Europe. And they are developing materials that will be able to with- stand such tiny particles better than ever before.

Dr. Daniel Emil Mack tests how particles of sand or ash damage aircraft turbines and how the different parts can be protected.

How ash and sand can damage aircraft turbines

Incoming particles erode the metal

Molten particles attack ceramic protective coatings

Particles block the fuel feed and cooling system Compressor Combustion chamber

Turbine

Then, we inject our model sand, which is mainly a mixture of calcium, magnesium, aluminium, and silicon as well as iron, into the flames.” In con- trast to other test stands, this simulates not only the thermomechanical effects on the material but also the chemical attack – just like would happen if an aircraft was to fly through an ash cloud or a desert storm.

In this way, the researchers can test various mate- rials and scenarios. They heat the specimens and then cool them, simulating take-off and landing of an aircraft. And they continuously increase the influx of silicates in order to determine what concentrations begin to damage the ceramic protective coatings.

“We now know more about how silicates attack turbines and how the materials react,” says Mack.

The researchers can thus estimate the hazard potential of volcanic ash and sand. And industry is also interested in such predictions. “Many large European companies come to us to test the load- ing capacity of their protective coatings, and the problem is also becoming increasingly important for turbines in power plants.”

Mack and his colleagues at Prof. Olivier Guillon’s institute are also developing new ceramic mate- rials which they then test extensively – including exposing them to attacks from molten silicates.

“We construct sacrificial coatings that can withstand the attacks long enough to ensure the safe return of the aircraft in cases of emergency.

More robust coatings would also cut the costs of maintenance because the turbines would have to be repaired less frequently,” says Mack, explain- ing the results to date. By the next large volcan- ic eruption, aviation will hopefully be better equipped to deal with the ash cloud: with robust data and robust materials.

C HR IS TO PH MANN

Satellite images of the eruption column of Eyjafjallajökull on 11 May 2010. The visible ash cloud stretched some 850 km from Iceland to the south.

2.2 plus

additionally use computer models to predict air flows and clouds. “We then know whether we need to change our flight course at short notice in order to obtain interest- ing data. The fact that we can talk to the pilots and alter our flight route at any time particular- ly impressed me,” says Dr. Christian Rolf. The 31-year-old Jülich atmosphere researcher was on board two HALO flights last year – together with Jülich instruments like FISH. The Fast In Situ Stratospheric Hygrometer is used by scientists at altitudes of between 8 km and 15 km to deter- mine the ice water content in cirrus clouds above Europe.

Securing one of the coveted seats in the aircraft is difficult. For the structurally identical busi- ness jets, you simply need a lot of money. For scientists, a different currency does the talking:

knowing a measuring instrument inside-out gives them an edge because the instruments must be intensively monitored throughout. And of course, each measurement campaign must be excellent in its own right. A scientific steering committee decides whether the methods and aims of a proposed mission warrant take-off or not.

FR ANK FR I C K

Normally, it’s the preferred method of transport for the rich who have an appointment or want to go golfing. Converted and named HALO, this plane provides information on the atmosphere and the climate.

Researchers and instruments from Jülich are frequent flyers.

In contrast to business-class passengers, the atmosphere researchers are surprised when served coffee during their eight- to ten-hour flights. They’re not used to it! Normally, they conduct their measurement campaigns with old propeller planes with none of these comforts.

A mechanic has stepped into the role of steward.

For reasons of safety, he has to be on board and usually he has the most easygoing of jobs.

The team of four to eight researchers, however, is under pressure. They operate the numer- ous measuring instruments that fill the cabin.

And they do this while consulting with their colleagues on the ground who also track the measurements and weather forecasts and

15.5 km

Jülich’s campus measures 2.2 km². But Jülich scientists are active beyond the cam- pus. This section features brief reports on where they conduct research. This time, we’re flying high – at an altitude of up to 15.5 km.

HALO

High Altitude and Long Range Research Aircraft

FUNDED BY

• Federal Research Ministry

• Helmholtz Association

• Max Planck Society MAX. CRUISING ALTITUDE:

15.5 km

RANGE

more than 8,000 km WEIGHT (EMPTY) 22.23 t

LENGTH 31 m MAX. SPEED 1,054 km/h

Jülich

In-flight research

HALO Gulfstream G550