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Resource Documents: Portugal (14 items)


Unless indicated otherwise, documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are shared here to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate. • The copyrights reside with the sources indicated. As part of its noncommercial effort to present the environmental, social, scientific, and economic issues of large-scale wind power development to a global audience seeking such information, National Wind Watch endeavors to observe “fair use” as provided for in section 107 of U.S. Copyright Law and similar “fair dealing” provisions of the copyright laws of other nations.

Date added:  February 14, 2014
Health, Noise, Portugal, VideosPrint storyE-mail story

Low-Frequency Noise and Health: A Wind Turbine Case (2007–2013)

Author:  Alves-Pereira, Mariana; and Castelo Branco, Nuno

My group has been studying low-frequency noise for 30 years. Initially we began with people working in low-frequency noise [environments].

Low-frequency noise is a little bit like light. You know that there are x-rays that you do not see, but it is light. You know that there is ultraviolet that is bad for your skin and you do not see it. If you use dark glasses for x-rays or ultraviolet, it will not protect you. This is similar to noise.

Over the years, we, the scientific community, have decided that noise only affects your ears. That is why we have the dB(A) unit to measure noise. Because we are interested in only measuring the noise that will causing hearing damage. Low-frequency noise does not cause hearing damage. It will not make you deaf. It is not measured when you use a dB(A) unit.

Compare the light with the noise. On top you have noise, on bottom you have light. Look what we do with the light. We separate UV, infrared, x-ray. We do not do this with acoustics. So how do I know which part is affecting your heart? Or you lungs? It’s all in one big bag. This is the problem with measuring the agent of disease.

On top you see what is a noise wave. I am here and the noise that is coming is going to hit my body. What you see on the right is your cells. So when the cell gets the impact of the wave, it will move. Like you see underneath.

Our case with wind turbines began in 2007. As you can see on the left, you have the house and the 4 wind turbines that were put around this house in 2006. This is what it looks like.

I am a scientist, I can not put up information about the noise that was measured without giving you the technical specifications of how it was measured.

So, the red is the noise in the house without wind turbines working. The black and the grey is with the wind turbines working day and night, night and day. This is measured inside the bedroom – not outside. Do you sleep outside? So if anyone comes to measure the noise because of the wind turbines, and they do not go into your house, you will laugh – yes? So as you can see at least in this house, these wind turbines were responsible for a great increase in the low-frequency noise in the bedroom.

So what happened to this family? The wind turbines began operation in November 2006. Immediately the family recognised that they were waking up tired. The dogs that used to be jumping and always wanting attention were now sleeping. You had to step over them. The horses were lying down in their stable. And ants disappeared. In March 2007 the parents received a letter from the teacher of the boy, of the son, asking why this child was so tired now. He was losing all interest in school, he had no energy for physical education and a very good student was suddenly going down, down, down.

And this is the point [when] that the family contacted us. Unlike the Massachusetts report, and others, we did not give questionnaires to find out how the people’s health was developing. It is not through questionnaires. No questionnaires. If you have people with cancer, would you accept a doctor who would attempt to cure the cancer with a questionnaire? Tell me what disease is evaluated just with questionnaires?

We gave this family the tests, the medical (not subjective) tests, that we would give to the workers in low-frequency noise. What you are seeing now is the development of symptoms and signs related to the disease developed by exposure to low-frequency noise. Signs and symptoms associated with the disease that you develop if you are in low-frequency noise. As you see, it is over years that it develops. If you have low-frequency noise in your home on day 1, day 2 it’s okay, day 3, day 4 – in a year! In 6 months, a year, 2 years, then it’s a problem. Then you realise. Then it is 6 months that you are tired and can not sleep, not a wink.

This is the test that we give to people to see if they have problems with low-frequency noise disease. On the right the test measures the time your brain takes to respond to a stimulus. Normal is 300 milliseconds. In the 12-year-old child in the wind turbine house, he was having in June 2007 352 milliseconds – this is a huge difference. When the child left the house for vacation, in September after being away from the house for 2 months the measurement came closer to normal.

On this side we have a breathing test. This breathing test measures how well your brain is controlling your breathing. Usually, if you have lesions in the brain, you will have problem in the breathing – and this is what this machine measures – not questionnaires. Normal for that examination is above 60%, and as you see the husband and the wife were already showing lower values. The child was not tested.

What is happening with the legal [case]? This man, this family put the wind turbine developer in court. In 2007 as a precautionary measure, the court said, take out wind turbine 2 – as you can see the white arrow, there used to be a wind turbine there. The court said that one has to go. And the other three must be turned off at night. And while this court case was ongoing, the developer continued putting wind turbines all along (red arrows).

Today, the Supreme Court of Portugal decided that all four wind turbines must be removed. Of course it is only those four because the other ones were not covered by this case. The wife and children no longer live in this house since 2007. Only the father is in the house to take care of their horses. Today his health has visibly deteriorated.

This is basically my information to you about what we know about wind turbines. Of course, 30 years of research into low-frequency noise – you can not speak in 10 minutes all the information.

(E-mail: m.alvespereira@gmail.com).

Presented 20 November 2013 at Nieuw Buinen, The Netherlands, by courtesy of Stichting Platform Storm

Transcript and video captures by courtesy of Stop These Things.

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Date added:  May 11, 2013
Health, Noise, PortugalPrint storyE-mail story

Portuguese Family and Horses Affected by Low-Frequency Wind Turbine Noise

Author:  Alves-Pereira, Mariana; Castelo Branco, Nuno; et al.

On the Impact of Infrasound and Low Frequency Noise on Public Health – Two Cases of Residential Exposure

Abstract: Noise exposure is known to cause hearing loss and a variety of disturbances, such as annoyance, hypertension and loss of sleep. It is generally accepted that these situations are caused by the acoustical events processed by the auditory system. However, there are acoustical events that are not necessarily processed by the auditory system, but that nevertheless cause harm. Infrasound and low frequency noise (ILFN, <500Hz) are acoustical phenomena that can impact the human body causing irreversible organic damage to the organism, but that do not cause classical hearing impairment. Acoustical environments are normally composed of all types of acoustical events: those that are processed by the auditory system, and those that are not. It is generally assumed that acoustical phenomena not captured by the human auditory system are not harmful. This is reflected by current noise assessment procedures that merely require the quantification of the acoustical phenomena that are audible to human hearing (hence the dBA unit). Thus, studies investigating the effects ofnoise exposure on public health that do not take into account the entire spectrum of acoustical energy are misleading and may, in fact, be scientifically unsound. Two cases of in-home ILFN are described. …

Case Report 2: Family R. lives on a horse- and bull-breeding farm, located in a zoned, rural agricultural area, 1 hour north of Lisbon. Family R. consists of mother, father, 12-year-old son, and 8-year-old daughter. In November 2006, 4 wind turbines (2MW each) were installed around Family R.’s farm, at approximately 322m, 540m, 580m and 643m from the residential home. The distance to the stables is less than to the residential house. …

The wind turbines installed around Family R.’s home began operation in November 2006. In March 2007, the parents received a letter from the school inquiring about the reason for the sharp decrease in the memory and attention skills of the 12-year-old child, and the overwhelming tiredness he exhibited during physical education classes. The school questioned the parents if the boy was getting enough hours of sleep during the night.

The entire family has already received the typical vibroacoustic disease diagnostic tests, including echocardiograms which did not disclose any significant thickening of cardiovascular structures. Tissue fragments have been removed from the farm animals that have been scheduled for slaughter, and will be submitted to the light and electron microscopy analyses that this team usually conducts on ILFN-exposed tissue fragments. These procedures will be repeated every 6 months, and follow-up reports will ensue.

Revista Lusófona de Ciencias e Tecnologias da Saúde, 2007; (4) 2: 186-200

Mariana Alves-Pereira
Direcção de Radiologia da Escola Superior de Saúde Ribeiro Sanches, Lisboa, Portugal.
Departamento de Ciencias da Saúde, Universidade Lusófona, Lisboa, Portugal.
Nuno A. A. Castelo Branco
Centro de Performance Humana, Alverca, Portugal.

Download original document: “On the Impact of Infrasound and Low Frequency Noise on Public Health – Two Cases of Residential Exposure
Baixar documento original: “Sobre o Impacto de Infrasons e Ruído de Baixa Frequência na Saúde Pública – Dois Casos de Exposição Residencial”

Family with Wind Turbines in Close Proximity to Home: Follow-Up of the Case Presented in 2007

In 2007, at the 2nd International Conference on Wind Turbine (WT) Noise, held in Lyon, France, low frequency noise (<500 Hz, LFN)–induced pathology, consistent with vibroacoustic disease (VAD), was shown to be emerging in the R. Family, exposed to residential LFN generated by 4 WTs installed in close proximity (300-700 m) to their home. Herein, a follow-up is provided.

The wife and 2 children no longer reside within that home. Mr. R., however, must remain to care for the thoroughbred Lusitanian horses and bulls that he trains and breeds for bullfights. In addition to the continued deterioration of Mr. R’s health and well-being, his financial situation is aggravated by the condition now appearing in his horses during the first year of life. Between 2000 and 2006, 13 healthy thoroughbred Lusitanian horses were born and raised on Mr. R’s property. All horses (N=4) born or raised after 2007 developed asymmetric flexural limb deformities. WTs began operations in November 2006. No other changes (constructions, industries, etc) were introduced into the area during this time.

Tissue analyses of the defected tendons were performed and revealed the classical features of LFN-induced biological responses: thickening of blood vessel walls due to proliferation of collagen in the absence of an inflammatory process.

14th International Meeting on Low Frequency Noise and Vibration and Its Control, Aalborg, Denmark, 9-11 June 2010

Nuno A. A. Castelo Branco
Luis Amaral Dias

Centro da Performance Humana, Alverca, Portugal
Teresa Costa e Curto
João Pedro da Costa Pereira

Sociedade Hípica Portuguesa, Campo Grande, Lisboa, Portugal
Luisa Mendes Jorge
Júlio Cavaco Faísca

Faculty of Veterinary Medicine, Universidade Técnica de Lisboa, Lisbon, Portugal
Pedro Oliveira
José Martins dos Santos

Instituto Superior de Ciências da Saúde Egas Moniz, CiiEM, Almada, Portugal
Mariana Alves-Pereira
Universidade Lusófona–ERISA, Lisboa, Portugal

Family with Wind Turbines in Close Proximity to Home: Follow-Up of the Case Presented in 2007

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Date added:  May 10, 2013
Health, PortugalPrint storyE-mail story

Acquired flexural deformity of the distal interphalangic joint in foals

Author:  Pereira Costa e Curto, Teresa Margarida


Since 2008, a high prevalence of front limb acquired flexural deformities was observed in a Lusitano stud farm. This work aims to evaluate this problem by reporting the results from tissue alterations in the affected animals as well as environmental conditions and management changes that could have led to this observation.

A total of eleven affected animals were studied. In these, complete physical and orthopaedic examinations were performed, specifically the determination of the angle between the dorsal hoof wall and the floor. Radiographic examination, CT imaging, determination of the thickness of the cortical bone of the third metacarpian and histopathology of some tissues collected in biopsy and necropsy were done in a subset of affected foals. All the animals had been supplemented with balanced commercial diet for equine. To investigate a possible genetic cause, two foals from distinct bloodlines were brought to the stud. These also developed the deformities after 6 months. Two of the affected foals were placed in a pasture away from the initial one and two others were admitted at the Faculdade de Medicina Veterinária de Lisboa. In those animals, except for one that had to be euthanized for humane reasons, an improvement was observed on their condition, with partial recovery from the deformity.

Histopathology was performed from (i) the tendon obtained by surgical desmotomy in one foal, (ii) tendon biopsies from three foals and (iii) the tissue of one foal during necropsy. Histologically the most significant alterations were the dissociation of myofibrils of the smooth muscle. This was predominantly seen in the small intestine but also in the walls of small capillary vessels, including those of the tendon vasculature.

The flexural deformities have a complex and multifactorial etiopathogeny. They occur due to uncoupling of the longitudinal development of the bone and its adjacent soft tissues, but also from shortening of the tendon-muscle unit in response to pain. In the case series presented here, there was no obvious cause for the development of this problem, therefore we hypothesised that unusual environmental conditions might have played an important role in the development of this condition, especially those introduced in recent years.

Translated excerpts:

From the stud farm’s establishment in 2000 to 2008, these symptoms had not been observed in any horse, and there was no alteration of diet (quality and quantity), conditions of housing, and physical exercise that the horses experienced.

The appearance of the deformities coincided with the installation of 2-MW wind turbines on land contiguous to the farm, this being the only environmental alteration that has occurred.

[This is the 18-MW Alto da Folgorosa facility of nine Repower MM92 turbines (rotor diameter 303 ft, total height 414 ft). Four turbines began operation in November 2006, the closest one of which (322m from the home) was shut down and removed after the family began legal proceedings, and six additional turbines began operation in September 2008.]

The entire area in which the horses are housed and exercised is ~350-800m [1150-2625 ft] from the nearest wind turbine.


A main objective of the study is characterization of mechanical vibrations induced in different locations of the farm by operation of wind turbines in close proximity, in order to analyse possible effects of such vibrations on horses.

Dissertação de Mestrado em Medicina Veterinária, 2012

Teresa Margarida Pereira Costa e Curto
Faculdade de Medicina Veterinária
Universidade Técnica de Lisboa

Download original document: “Acquired flexural deformation of the distal interphalangeal joint in foals
Baixar documento original: “Deformação flexural adquirida da articulação interfalângica distal em poldros”

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Date added:  December 15, 2009
Economics, Emissions, Grid, PortugalPrint storyE-mail story

Integrating Wind Power in Portugal

Author:  Moura, Pedro; and de Almeida, Anibal

It is variable and hard to predict, but wind energy is increasingly being employed in European countries in order to hit their renewable energy targets. The EU is currently aiming for 22% renewable energy production by 2010. Portugal has the far more ambitious target of 39%. Therefore, Portugal is planning a large increase in its wind energy capacity over the next couple of years, in order to achieve an installed capacity of 5300 MW by 2012.

Assuming a scenario where large-scale penetration of electricity generation from wind and other intermittent renewable energy resources is achieved, it is of fundamental importance that the electricity system into which these new power generators are being integrated is able to compensate for the variability of production.

Hydropower and solar power can be used to boost production capacity – Portuguese hydropower capacity is large and significant photovoltaic development is planned – but energy storage, demand side management (DSM) and demand side-response (DR) could also play a major role in optimizing capacity for wind power production. As wind energy is stochastic in nature and essentially ruled by random meteorological changes, its ability to reach peak load requirements is the biggest problem for producers of wind energy. Therefore, wind energy should be considered an energy resource but not a peak capacity resource, as only a small fraction of wind capacity has a high probability of running consistently. Wind is, and should be, used when available and if capacity exceeds demand then this should be viewed as a bonus.

Wind intermittence can also affect the economic viability of projects, as it leads to lower value energy. Most wind generation occurs in hours when energy use is low, making it less valuable. Studies have shown that as wind penetration increases, three factors lower the economic value of wind power:

Managing Intermittency

Intermittency is a long standing and recognized problem for many forms of renewable energy. Efforts to overcome the effects of variability and randomness of wind power availability has been traditionally addressed by the promotion of wind power resource studies in the industry, and the identification of solutions based on reversible hydroelectric dams, or pumped storage.

The intermittency of wind energy can also be reduced by some other estalished techniques:

The last three of these techniques can be grouped as aggregation and distribution methods. These techniques aim to increase the predictability of the production of wind power and therefore achieve a substantial reduction in system variations.

However, although those improvements bring benefits, as Table 1 (below) shows, periods of low wind production and substantial variations will remain. Thus tools to respond to short-to medium-term and long-term variability of power production are necessary in order to manage the operational and capacity reserve. For large-scale integration of wind power the provision of flexible capacity reserve is of crucial importance. To achieve this aim several options are available [as follow].

Extreme variations of large-scale regional wind power

Wind Power Forecasting

In addition to being variable, it is also challenging to accurately predict wind power production within the time scales which are necessary for long-term planning. It is easy enough to predict energy production from a large wind generation facility over a long period of time – even over the life time of the plant – but over shorter time periods, production is less easy to predict. Large divergences can occur in the timing of and the wind’s amplitude.

Aggregation and Distribution

Generally, the more wind turbines which are operating in a given period, the lower the production variability is. Similarly, the more turbines which are installed across a geographical area, the more predictable production becomes, as shown in Table 2 (below).

Wind power step changes

The number of hours with zero output will also decrease when using turbines based over a large area. A smoothing effect in the system wind power production can be achieved over large areas, as the correlation between the number of wind generators and the energy produced will be lower.

Interconnection With Other Grid Systems

This will enable the export of energy in times of wind power production in excess of demand; and imports when production is reduced.

Power Plants Providing Reserve

The use of alternative power plants to provide operational capacity and reserve is the most traditional method of integration of intermittent power. Plants which can provide such system must be flexible and have short response times, in order to make up the lost capacity from wind production quickly. Hydropower is the technology which presents the most advantages. Fossil-fuel supported power plants, can be also be used. However, the biggest disadvantage associated with this method is that it is not cost effective to run extra capacity which will only operate when wind capacity is suddenly reduced. Also, the greenhouse gas emissions released by this kind of installation negates the positive benefits of using renewable wind energy.

Curtailment of Intermittent Technology

To ensure system stability and control, a minimum level of conventional generation must be maintained, even in periods of low demand. Other situations which can limit wind power may occur when the transmission and distribution capacity is congested near the wind farm. In such situations the curtailment of wind power generation can be used to reduce the overall system integration costs.

The curtailment is made by constraining the output of a group of wind generators, shutting down some or all the turbines. This will result in a loss of energy production and in economic losses. The costs also include the time taken for the wind farm to become fully operational following grid curtailment.

Distributed Generation

The use of other types of distributed generation can provide several benefits in the network, such as: alleviating congestion, reducing transmission losses and providing ancillary services. Distributed generation can also help in wind power integration, providing reserve capacity as a substitute for conventional power plants. However, wind power is normally a form of distributed generation and has the same requirements for grid connection. Several other types of distributed generation technology can also have intermittency problems, like solar power for example.

Synergy Between Renewable Sources

Hydropower and solar power are also intermittent resources, due to their dependence meteorological conditions. However, the variables affecting these three different forms of renewable resource are independent of each other and do not necessarily occur at the same time. They can therefore be partially mutually compensated.

Analyzing 50 years of data on wind velocity in Portugal shows high variation relative to the average year, with a consequent impact on the yearly variation curve.

The wind velocity and the water inflow have average variations through the year which follow a similar pattern and their two curves have a high correlation (0.98). The solar radiation varies almost inversely, relatively to the wind velocity and the water flow (correlations of −0.7 and −0.66, respectively). That observation indicates that the complementary relationship between solar energy and wind/hydro is favourable. Solar energy can therefore be used to smooth seasonal variations of wind power. Hydropower is not complementary to wind power, but due to similar variations it is the ideal means to store excess wind energy in order to cope with the intermittence, using the storage, dispatchable power and dynamic response capacities. Also, other dispatchable energy technologies, such as biomass, can have a positive contribution, reducing the intermittent power requirements.

Demand-Side Management

Most critical situations occur in periods with high energy consumption. Thus, demand side management technologies could play a major role in avoiding critical situations due to intermittent power generation resulting from the increasing use of wind in the national generation portfolio. One of the most serious peak load problems is the need for elevated electricity production due to the increased use of air conditioning on summer days with high temperatures and reduced wind velocities. Therefore DSM technologies in space conditioning are important.

The European Union Energy Services Directive in Portugal aims to achieve a consumption reduction of 9% between 2008 and 2016. A variety of DSM technologies were considered in order to execute the plan. The aggregated impact in the load diagrams of the selected technologies in the residential (lighting, appliances and space conditioning), services (lighting, office equipment and space conditioning) and industrial (lighting, power factor, energy efficient motor systems and drives) sectors was determined. It was found that the application of DSM measures will reduce the amount of investment needed to integrate intermittent power and will lead to a large reduction in peak power demand.

Demand Side Response

DR is another technology which can play a major role in the integration of renewable intermittent power. With these technologies it is possible to direct or indirectly force a consumption reduction in critical situations, over a short period of time.

In the past, the grid has been planned and operated under the presumption that the supply system must meet all customer’s energy needs, and that it is not possible to control the demand. However, that is starting to change due to the creation of opportunities for customers to manage their energy use in response to signals, such as those coming from prices or load contracts.

If the marginal peak load price is higher than the value that a consumer gets out of the services derived from the electricity, they may be willing to modify the demand, if paid the peak price or slightly less. A grid operator can obtain a greater economic benefit by providing incentives for a customer to reduce their consumption rather than paying a power producer to supply more output. Traditionally the DR technologies were typically used to attend to economic concerns. However, they can now be used to improve the system reliability, instantaneously reducing the energy consumption to prevent the most unbalanced situations, like the problems that result from the large space conditioning consumption on days with reduced wind velocity. As more customers practice automated price-responsive demand or automatically receive and respond to directions to increase or decrease their electricity use, system loads will be able to respond to, or manage, variability from wind power production.

Energy Storage

Energy storage has crucial importance in the electricity sector, because the energy demand has relatively large hourly, daily and seasonal variations. Additionally, as energy generation from renewable energy sources also has significant variations, either in the short term (periods of a few seconds) or in the long term (hourly, daily and seasonal), storage is becoming increasingly important.

Energy storage is an appropriated option for allowing the large-scale integration of intermittent renewable sources. Energy storage in electric energy generation systems enables the adjustment between energy production and demand. The energy produced by intermittent renewable sources can be transferred to be released in low production or high consumption times. Storage technology has the advantage of generally not using fossil fuel generation, so storage facilities do not directly contribute to greenhouse gas production. One disadvantage of energy storage are the inherent losses due to the efficiency of energy conversion (about 75%–80% typically), as Table 3 (below) shows.

Energy storage technologies

The storage devices do not need to be located in the wind farms and can be installed at any point on the grid. Several energy storage technologies can mitigate over-generation problems, absorbing the surplus energy in a few seconds. Each technology has its response rate, varying from a few seconds to some minutes, but all can quickly connect to the system and ramp up to add load to the system. Hydro storage facilities, whether in the form of pumped-hydro or hydro reservoirs, have played a key role in providing several grid balancing services. Large pumped storage hydropower plants can be switched from generation mode to pumping mode within a few minutes, storing the excess energy produced by the installed base of wind power capacity and releasing the energy for use meeting demand when wind production decreases.

This kind of storage has potential for large-scale electricity storage, fast response times and reduced operating costs.

Some storage devices can provide regulation services and frequency control. Hydropower can ensure such a requirement due to having fast ramp rates and can maintain maximum power for several hours. However, other technologies can be used, such as NaS (sodium-sulphur) batteries or flywheels. Storage systems that incorporate an inverter can also deliver reactive power, supporting voltage regulation.

Of the storage energy technologies available (as shown in Table 3 above), only hydropower has been used for many years and is well established in the market. The other storage technologies present non-competitive costs and reduced commercial availability. The major barrier for construction of new storage facilities is not the technology but the absence of market mechanisms which recognize the value of the storage facilities and financially compensate them for the services and benefits they can provide. Certain storage systems such as flywheels, flow cells and certain battery types could become viable. Another viable technology is compressed air depending on available locations, which is stored in geologic structures under the ground and released when necessary.

Integrating Wind

All of these options have the same aim: to balance supply and demand continuously. The first course of action when ensuring the effective integration of variable energy sources into an electricity grid should be various project techniques, including grid integration, technical distribution of the generators, geographic distribution of the generators and improved forecasting techniques. However, with large-scale integration of wind power, periods of large intermittence will remain. Therefore it is important to integrate other technologies alongside these project techniques. The complimentary relationship between renewable sources, demand side management and demand side response are all important, and energy storage technologies are rapidly improving, becoming more available. The diversity of these options means there is great potential for wind energy to be successfully integrated into domestic electricity grids, if proper planning is implemented.

Sidebar: Extreme Variations in Wind Power Ramp

Several extreme ramp rates have been recorded during storms:

Pedro S. Moura is a researcher at the Institute for Systems and Robotics (ISR), at the University of Coimbra in Portugal. Anibal T. de Almeida is professor of Electrical Engineering and Computers, and a director of the ISR.

This article was adapted from a paper which was first presented at the Renewable Energy World Europe conference in Cologne, May 2009.

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