July 29, 2014


Citations and the problem of capturing impact

As this week there is again a lot of talk about journal impact factors with the release of this year’s data later today, I like to take this timely opportunity to look at citation metrics more broadly, in terms of fundamental flaws in weighing data, and important data missing in the underlying data sets, which in my view miss important data when it comes to practical, technological impact of a study.

I recently had the opportunity of attending a talk by Paul Wouters from Leiden University, a professor of scientometrics. He pointed out one of the fundamental flaws in citation metrics that goes right to the heart of such data collection, before one should even discuss more superficial metrics such as h-index or the impact factor. Like any other piece of data, the context of a citation matters, he said. Factors that play a role are the type of paper where a reference is cited, and in what way. Was it criticism? Controversial papers for a while at least can gather a lot of citations even though eventually their impact on scientific process can be nil. There are also human aspects. Relevant points here are who cited a paper, was it a self-citation, or were there other motivations for citations? After all, citation cartels are not unheard of.

There is a lot of literature on various aspects of citation analysis, and more details on this can be found in Wouters’ doctoral thesis on citation culture, or in the 2008 paper by Jeppe Nicolaisen on citation analysis.

More broadly speaking, I am not sure whether it will be possible to properly analyse and process context when it comes to citation analysis. There are too many ways to game such systems. However, a more complex analysis might well be possible, taking the example of he ranking of web sites in search engines. There, context is everything. A website that is linked from many other sites is not necessarily an important one. Instead, a link to a web site from an important web outlet such as a popular news web site weighs much more than links from unknown web sites. Indeed, many links from news web sites or social networks might also be an indicator of immediacy, further propelling a site up the search engine rankings. [...]

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June 17, 2014


Power grid networks in Scandinavia

Power grid designs for the future

Planning electrical grids in a steady environment is not overly difficult. A number of large power stations are connected to urban population centres, where much of the power is consumed. Typically, such power grids would look like meshes with  interconnected distribution points that make sure that if one power station fails, others can compensate .

However, as electrical demand grows, the solution is that new power plants are built and linked to the net at various places, but often with only one connection to the network. These dead ends make the network very susceptible to blackouts, even if many of them are connected by two parallel power lines for redundancy.

In future, the use of renewable energy will pose even greater demands on such network architectures, because the distributed generation of power makes the power generation very dynamic. If the sun shines in certain parts of a country, or the wind blows strongly in one area, large amounts of power will need to be shifted between regions, and the power grids need to be capable of handling that. [...]

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June 13, 2014


Researchers joining forces to buy helium

Whenever I meet researchers working in low-temperature physics, the worry are helium prices. When I did my PhD a long time ago, I was able to buy 100 litre dewars of liquid helium without thinking too much about its price.

Since then, times have changed a lot, and prices have multiplied over the past years. The reason is that helium is a scarce commodity. In the atmosphere, helium is impossible to catch and most of it comes from underground, created by the radioactive decay of heavy elements. The United States have a large stockpile underground in Texas, which when depleted will mean the end of most usable helium sources.

To combat the rising prices, the American Physical Society, the American Chemical Society and the US Defense Department’s procurement agency are now planning to bundle their forces and to buy helium for researchers at volume discounts. Nothing wrong with that, this is certainly a good idea that will make it easier for US researchers to do cryogenic experiments.

Regardless, we should not forget that helium is not a renewable resource. One group of scientists using more of it at a cheaper price ultimately means shortages elsewhere. Whether it is for science and researchers elsewhere on the globe, for medical NMR equipment, or in other areas. This is where we still need to work on. Either through improved cryostats in research, or by avoiding unnecessary uses of helium, such as in helium party balloons, which incredibly are still being sold to be released into the atmosphere for nothing.

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December 8, 2013


Graphene and the innovation gap

This week some rather pessimistic articles on graphene’s commercial potential appeared in the UK press. On Tuesday, Aditya Chakrabortty commented in the Guardian on “How UK wonder substance graphene can’t and won’t benefit UK“, highlighting some pretty poor statistics when it comes to the innovation in graphene here in the UK, where Andrei Geim and Kostya Novoselov carried out their pioneering research:

Our record with graphene has been similarly dismal. Consultants calculate that China has taken out more than 2,200 patents on the material; the US more than 1,700; South Korea is closing in on 1,200. And the country that discovered it? Just over 50.

One of the problems, Geim is quoted in the article, is that there isn’t industrial sponsorship for his research:

Here is one of the world’s great scientists, pointing out that British businesses are either incapable or unwilling to use his inventions. The effect is rather like James Watt complaining that he can’t find any takers for his new steam engine.

This negative picture from a research perspective has been contrasted from the industrial side with a commentary by Jonathan Ely in the Financial Times this Saturday, saying there is too much investment into graphene: “The growing graphene investment bubble” (reading this link requires free registration at the FT). For Ely it seems the problem is not the industrial side – several companies now are on the market aiming to commercialize graphene – but that there is just nothing interesting about graphene (even though the Guardian continues to call it a ‘wonder’ material):

Graphene has been around since 2004, and many patents connected with it have been filed around the world (the Koreans are especially interested). Bill Gates has suggested it be used to make indestructible condoms to prevent the spread of disease in the developing world. But so far there are no widespread commercial uses for it.

How to consolidate these contrasting views? Perhaps the problem is that companies do not see the potential of graphene in the same way as Geim does. Graphene came from blue sky innovative research done by Geim and Novoselov, born more out of curiosity than because of commercial aspirations. Still, when the Nobel prize was awarded to these pioneers, commercial applications featured prominently in the comments of the Nobel Prize committee. This even caused me to call for caution on the technological potential. And it is fair to say that the promised broad-sweeping applications particularly based on graphene’s electronic properties have not yet materialized.

But this does not mean that all is bleak. [...]

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