Thursday, 9 June 2011

The Blog is Back!

I've been cleaning out the cobwebs after a few months of blog neglect, (check out the tab 'What's the background picture?' for a little more info on the new background) and what a few months they've been... I finished up my project in the Faul group on conducting polymers, had a paper published from the research I carried out in America and most importantly finished my degree!

Here are a few things that I've learned during revision madness:

1) No matter how long you have to study for an exam, you will always need one more day.

2) 12 hours of studying a day can make you pretty crazy, but surrounding yourself with people who are equally crazy makes you seem a little more sane.

4) The UoB Arts and Social Sciences library at opening time during exam period is a frightening place to be and for hordes of desperate students, mob mentality rules.

5) When given a daily work out the brain can absorb information at a surprising rate. When given numerous pints of beer, the rate at which it can forget things is pretty surprising too...

6) Lack of sleep can actually be deadly (discovered in the midst of a bout of pre-exam insomnia) as proved by some unwilling rodent test subjects.

7) A little zombie killing is good for the soul. Thank you Resident Evil 4 for the many study breaks we spent together.

8) Talking to people about an exam after it has finished is be highly dangerous and should be avoided at all costs, as demonstrated by Cyanide and Happiness;

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Sunday, 20 March 2011

Is the Hydrogen Economy Dead in the Water?

The idea of a ‘Hydrogen Economy’ was first put forward in the 1970’s and quickly captured the imaginations of scientists and non-scientists alike. The development of a power infrastructure utilising hydrogen gas promised a move away from fossil fuels, depleting and dirty, to clean cars, clean energy and clean living for all. Emitting only water when ‘burned’, the use of hydrogen as a fuel would allow for the development of a carbon free society and due to its high energy density, a more efficient one too. It promised not only to largely reduce CO2 emissions, but also pollution from CO, NOx, SOx, and particulates, all associated with the combustion of fossil fuels. Despite the initial excitement, development has been slow and forty years on, the ‘Hydrogen Economy’ has failed to materialise.

In recent years some steps have been taken in rolling out hydrogen technologies, albeit small ones. The area receiving the most interest has been the automotive industry. In London last year the first permanent hydrogen powered bus was introduced to a commonly used tourist route. This came after successful pilots between 2003 and 2007, and seven more are to be added to the route this year. The buses contain batteries which store energy generated not only from the integrated hydrogen fuel cell, but also from the braking process. Thirty nine of the buses, developed by an energy company based in Canada, also grace the streets of Vancouver and can run for up to 18 hours without needing to refuel.

One of the hydrogen powered buses being used in London

It is America however, that has seen the largest drive implement hydrogen power. Hydrogen was touted as the solution to America’s foreign oil woes. Due to the USA’s abundant supplies of coal and natural gas, from which hydrogen can be derived, a hydrogen energy infrastructure seemed the perfect solution indeed. California Governor Arnold Schwarzenegger promised a ‘Hydrogen Highway’ with 200 filling stations by 2010, connecting all of the major cities in California, yet currently only 30 exist. A further hitch to America’s hydrogen dream came last year when physics Nobel Laureate come Energy Secretary Steven Chu cut all funding for research into hydrogen fuelled vehicles.

With so much potential, what has gone awry with the ‘Hydrogen Economy’? Firstly the production of the material itself is problematic. Although hydrogen is one of the most abundant elements on earth, it doest not exist as molecular hydrogen except for in trace amounts (0.1 ppm) in the outermost atmosphere and can only be separated from other hydrogen-containing compounds. Steam methane reforming (SMR) is currently the most widely used and cheapest method for producing hydrogen, but is estimated that 13.7 kg of CO2 is produced per net kg of H2. Production of hydrogen using SMR also requires an input of energy and so it would be more efficient to simply burn the fossil fuels themselves.

Alternative methods of hydrogen production are being investigated which use different sources to derive hydrogen, most prominently water. Electrolysis currently accounts for approximately 4% of the global production of hydrogen, but current methods do not provide a viable solution. Not only expensive, they also require a large energy input, usually from fossil fuels. Systems which use renewable energy to drive the process offer some improvement. The National Renewable Energy Laboratory (NREL, a laboratory of the U.S. department for energy) are currently developing the wind-to-hydrogen project, which links wind turbines to electrolysers and uses the wind generated electricity to split water.

Photo-catalyzed water-splitting has emerged as a promising technique to efficiently generate hydrogen. It is driven using light in a similar way to photosynthesis and so the process is often termed artificial photosynthesis. In the process a photo-catalyst is excited by photons of visible light with energy equal to or greater than the material’s band gap. This generates electrons and holes which drive the decomposition;

2H2O + 4h+ →  O2 + 4H+
2H2O + 2e- →  H2 + 2OH-

The first example of a photo-catalyst to produce hydrogen was seen in the 1970’s by Japanese researchers A. Fujishima and K. Honda.1 They used a single crystal of TiO2 connected through an electric circuit to a platinum surface, (figure 1a), generating the required electrons and holes to split the water, but the rate of hydrogen production was too low to be economically viable. Further to this, the system produced a mixture of O2 and H2 and so an expensive separation process is required. 

Figure 1 – a) The Fujishima-Honda cell, and b) a photodiode for water splitting 2

In recent years the efficiency of the process has been improved by the use of a photodiode, (figure 1b), which allows separate production of hydrogen and oxygen in the two halves of the cell. The device consists of a metal sheet with a thin film of the photo-catalyst on one side, and a hydrogen-producing catalyst, such as platinum on the other, which sits between two separate water sources. When irradiated with light, oxygen is produced on the photo-catalyst side by holes, whilst hydrogen is produced on the platinum side by electrons which migrate through the metal substrate. Materials other than TiO2 have been investigated as potential photocatalysts, most noteworthy the NaTaO3:La system developed by researchers at the Science University of Tokyo,3 which shows the highest activity and quantum yield to date.

Another stumbling block which has prevented the ‘Hydrogen Economy’ from being adopted is the question of how to store hydrogen. Hydrogen gas occupies large volumes of space at atmospheric pressure, in fact a single gram of hydrogen takes up a whopping 11 litres of space. Due to its low energy density by volume, hydrogen must be either liquefied or pressurised. In its liquid form, it must be stored at cryogenic temperatures and so requires high energy input. Pressurisation also requires energy input and the containers required are weighty and expensive. Alternative storage methods include chemical storage methods such as the use of metal hydrides. Hydrides offer a practical solution for storage and transportation, however there are barriers associated with the high pressure and temperature conditions needed for hydride formation and hydrogen release. Other physical methods of storage are being developed such as the use of carbon nanotubes, nanoporous materials, metal-organic frameworks and polymers but all are costly compared to conventional storage methods for petroleum fuels.

It seems that ultimately what is holding the ‘Hydrogen Economy’ back is not that it is an inferior energy source, or lack of innovation in the field. The reality is that implementing a hydrogen energy infrastructure would be costly not only to governments but also consumers. It arrives to the age old question of conscience vs. cash; just how much are we willing to pay for clean guilt-free energy?

            (1)        Fujishima, A.; Honda, K. Nature 1972, 238, 37.
            (2)        Parkin, I. P.  Education in Chemistry, 2010; 47, 1.
            (3)        Kato, H.; Asakura, K.; Kudo, A. Journal of the American Chemical Society 2003, 125, 3082.

Tuesday, 1 March 2011

Can We Trust Scientists?

In a recent BBC Horizon documentary ‘Science Under Attack’, Sir Paul Nurse, a Nobel prize winning geneticist and head of the Royal Society, attempted to unravel why public trust in science is diminishing. The programme dealt specifically with the contentious topics of global warming, HIV and genetically modified crops. Typical to form, the subject provoking the most debate was global warming, during the programme itself, as well as in the subsequent fall-out.
Nobel Prize winner Sir Paul Nurse - what a lovely smile

In an attempt to present a balanced argument on the climate debate, Sir Paul interviewed a number of scientists, including those at the University of East Anglia (UEA) at the core of the 2009 ‘Climategate’ scandal, as well as one of their biggest naysayers, Telegraph journalist James Delingpole. ‘Climategate’ centred around a series of leaked emails and documents, revealing an apparent episode of misconduct from the Climatic Research Unit at UEA. Scientists there were accused of manipulating data to make the case for global warming appear stronger than it is. A media storm ensued, driven to a large degree by Delingpole. His dramatic statement that the elucidation of these damning emails would “save Western society from the greatest threat it has ever known […] Climategate”, was certainly overblown, particularly considering the controversy centred on a singular graph of global temperatures over the past millennium. The graph in question spliced two types of data; estimates of past temperature taken from indirect measurements, along with modern day data from direct measurements using thermometers.
In four independent reviews no evidence of dishonesty from the scientists was found, but the result was a smear on the reputation of science in general. Despite this outcome, climate-sceptic Delingpole remained on his soap-box, complaining of an unfair representation during the programme. Odd, since his own representation of global warming does not seem to be entirely fair or informed. Asked if, when forming his arguments, he consults peer reviewed literature, he claimed not to have the time, stating it wasn’t his job. Well then… who does this fall to? With science becoming an increasingly controversial and political topic, it is clear that more needs to be done to ensure the information released by the media is accurate.
James Delingpole airing his views on "climate change" - boo hiss

Misrepresentation of science by the media is not the only problem faced by scientists today. A very small minority of researchers have resorted to scientific misconduct and dishonesty in a bid to be published and gain recognition, tarnishing the reputation of ‘good science’. Perhaps Britain’s most infamous example is the MMR scare caused by Andrew Wakefield and colleagues at the Royal Free hospital in London, who linked the vaccine with the development of autism and bowel problems. Such was the impact of their 1998 paper on the topic that uptake rates of the vaccine dropped and subsequent levels of measles and mumps spiked, leading to death in a limited number of cases. Wakefield manipulated results from some of the patients to suit his conclusion, described by the British Medical Journal as ‘deliberate fraud’ in a review in January. He was consequently struck from the medical register, but the damage caused to the science community is lasting.
Outside of the UK, there are particular concerns about much of the research conducted in China, where numerous accounts of misconduct and fraud have come to light. China is soon set to overtake the US and Europe in terms of the volume of material being published and a need for greater transparency and honesty is evident. However, with the rise of the self-proclaimed “science cop”, Fang Shimin, a Chinese scientist who carried out his post doctorate research at an American university,  the nation can perhaps breathe a little easier. Through his website ‘New Threads’, he has become whistle-blower on a number of famed scientists and unsurprisingly has won many enemies. Last August, he was subject to a planned assault by one of his accused rivals. With incidences like this, it is clear China needs to clear up their scientific act, something which will be achieved only through the vigilance of people like Fang Shimin.
'Science Cop' Fang Shimin. The man on a one man mission to clean up Chinese science - cheers Fang

 A little more vigilance is required across the entire field. With peer-review practices differing across journals, it is easy to see how some papers slip through the net. A better communication line between scientists and the media would also ensure a little more consistency between what is coming out of the lab and on to our newspaper pages, restoring public confidence in science. At the heart of the issue, as Sir Paul stated in ‘Science Under Attack’, scientific debate now centres around “not just a clash of ideas, but whether the public actually trusts scientists”. Scientists have a responsibility to strive for clarity in their own work, as well as monitoring the work of others. Only then will they regain the faith of the public.

Friday, 18 February 2011

Is the Sun Setting on the UK Solar Industry?

Solar firms launch legal fight over subsidy rethink
Photo: GETTY

Solar power is the shining beacon of the renewable energy world. Increasing fossil fuel prices alongside anthropogenic global warming are seeing a fresh drive to explore whether solar power could be the answer to the fuel crisis. Enough sunlight hits the earth’s surface in a single hour to match the world’s energy demands for an entire year, yet current technologies are simply failing to match this incredible potential. Today there exist two main techniques to convert sunlight into electricity, either directly using photovoltaics, or indirectly using concentrated solar power.

Photovoltaics (PV) rely on semiconductor solar cells, which, when exposed to light generate electrons and create a current. PV is one of the fastest-growing energy technologies, with an estimated turnover of EUR 10 billion in 2007. The most widely used and well developed solar cells employ crystalline silicon, but these are quickly reaching their theoretical efficiency limit of 29%. Other functionalities are being investigated for use in solar cells –a particularly successful example being multijunction PV cells, which consist of multiple thin films of semiconducting materials. With this design, a new world record for sunlight-to-electricity conversion efficiency was set in 2010 by ‘Spire Semiconductor’, a solar technology company based out of Massachusetts USA, whose triple junction gallium arsenide solar cell achieved conversion with 42.3% efficiency.

Alternatively, concentrated solar power (CSP) systems use large lenses or mirrors to focus and concentrate sunlight onto a small area. The focused light creates incredibly high temperatures which are used to drive steam turbines in a similar way to conventional power plants. The process is highly efficient and a study by Greenpeace International estimated that CSP could account for 25% of the world’s energy demands by 2050.

Despite these sunny figures, the Department of Energy and Climate Change (DECC) announced £34 million worth of cuts to low carbon and renewable energy spending last July. When it comes to energy, it seems the government’s persuasions are not so green. Britain lags sorrowfully behind many of its EU counterparts in terms of renewable energy usage; a mere 5.1% of the total energy usage came from renewable sources in 2007 compared to 15.1%, 20% and a staggering 52% from Germany, Spain and Sweden respectively. Britain will see a long road to reach the EU agreed generation of 15% of energy from renewables by 2020.

The achievement of this goal was further hampered last week when a formal review on the feed-in tariff (FIT) system put in place just 10 months ago was announced. FITs provide government guaranteed price for electricity sold to the National Grid by renewable electricity generators. The system, which was originally introduced to the EU by Germany, has seen much success outside of Britain, particularly in Spain. FITs here saw the development of the world’s first commercial solar tower using CSP technology. It is predicted the plant will be able to generate enough electricity to power 200,000 homes. So what prompted the change in heart from the British government?

Numerous field-based solar arrays have recently emerged, threatening to leave FIT funds unavailable for the home owners, businesses and local communities for whom they were intended. The government have subsequently implemented a 50 kW cap on any projects, the size of which will include commercial and community building installations. With the promise of further cuts to come, there are concerns that the PV industry will be put in jeopardy. Instead of making cuts in a ‘knee-jerk’ fashion, the government should embrace these developments and attempt to stimulate growth in the UK PV industry. Many investors will undoubtedly be shelving projects for the manufacture and installation of solar cells -investors who would have otherwise been injecting some much needed cash into the market. With cuts to both the FIT scheme and to research and development funding, it seems Britain’s solar industry is destined to be left in the dark.

Sunday, 6 February 2011

2011: The International Year of Chemistry

Scientists everywhere rejoice, 2011 has been officially proclaimed the International Year of Chemistry. The announcement came from the International Union of Pure and Applied Chemistry (IUPAC), the governing body of all things chemistry. With further endorsement from the UN's Educational, Scientific and Cultural Organization (UNESCO), it looks to be an exciting year indeed. The British festivities kicked off at the Houses of Parliament, as the Royal Society of Chemistry president Professor David Phillips emphasised “science is not just theoretical, but also practical”. A series of bangs and flashes followed as the first ever science experiments were performed in Parliament by Professor Hal Sosabowski, of the University of Brighton, who put on a thoroughly good show of mad science, with a tie dye lab coat to boot.

The principle aim of the Year of Chemistry is to raise awareness of the subject and its role in society among the general public, as well as to attract young people into the field. This will be carried out with a number of events open to the public, as well as through participation in schools. A heavy onus will also be placed on the role of women in science, and in particular, to honour Marie Curie and her work. Especially pertinent as this year sees the centenary of Curie being awarded the Nobel Prize in chemistry.  Not only the first woman to claim the prize, she was also the first ever person to be awarded two (several years earlier she and her husband had received the shared prize in physics). She remains an aspirational figure, a viewpoint clearly shared by the chemistry department at the University of Bristol, who are hoping to put on a lecture in her honour sometime this year.

Whilst Bristol and the surrounding areas have their fair share of activities planned, the event schedule is somewhat poorly advertised, as with the Year of Chemistry itself. If IUPAC do intend on enticing members of the public to show an interest in chemistry, perhaps they ought to consider publicising to a wider audience than just the readers of the Royal Society of Chemistry website. Despite this, it is still early in the year and it seems momentum will be gained, as there are certainly some attention-grabbing events to come. Take for example the world’s largest experiment, aptly named the ‘Global Experiment’. School children across the globe will participate in four different experiments, all based on water and its role in society and the environment.

In spite of its few teething problems, the Year of Chemistry presents a fantastic opportunity for scientists and non-scientists alike to become involved and have fun with the subject. Bristol boasts a plethora of science based activities able to excite anyone. Head down to the At Bristol science museum where you will rediscover your inner child (and maybe learn something too!) With over 300 interactive exhibits there is plenty to keep you amused, but be warned, unless you visit on a week day, be prepared to wrestle with a hoard of grabby children and toddlers to have a turn on any of the exhibits. If you can’t spare the hours during the week, you would be wise to visit an hour and a half before closing time on the weekend, as not only have the stream of small competitors filtered away, you also get half price entry; bonus. At Bristol is also a regular host of the Science Cafe, where you can come face to face with expert scientists from a number of different fields, hear them speak about their subject, then give them a grilling. Science cafe meets during the evenings of every second Tuesday of the month, and best of all is free.

Getting interactive at the 'At Bristol' Science Museum

But why should we be celebrating the discipline of chemistry with such fervour? When the head of the University of Bristol chemistry department Professor Tim Gallagher asked what had drawn him to the subject, he replied “Crudely, blowing things up. I was a pyromaniac as a child. However I’m against the stereotype of chemistry being explosions and bangs and fires. What really hooked me was the role of chemistry in healthcare and pharmaceuticals, which has made a profound impact on quality of life.” And indeed, we have much to thank chemistry for. The world would be a very different one, a much worse one, without people tirelessly studying chemistry, and that certainly is worth celebrating. Happy New Year of Chemistry.

Some resources;
· the homepage for the IYC
· database of events happening for the year of chemistry. For local events just choose your area in the ‘RSC Local and International Sections’ box
· information about upcoming Science Cafe evenings
· a video put out by the American Chemical Society considering a world without chemistry

Monday, 20 December 2010

Heathrow Airport Chaos: An Account From A Frustrated Traveller

It’s been a week which has seen Britain brought to its knees. With the coldest December since 1910 and heavy snowfall around the country, chaos has ensued. Thousands were left stranded on motorways as roads closed and accidents inevitably occurred.  Motorists nationwide faced queues of up to 8 hours and scores simply abandoned their cars. Trains were also affected with speed restrictions and a severely limited timetable throughout the network.
But perhaps the worst afflicted were Britain’s airports. Only around half of the flights out of Gatwick left over the weekend as it was forced to close for part of Saturday. Yet it was at Heathrow, the world’s busiest international airport, that the worst disarray was seen. Over 350,000 passengers were left stranded, myself included, as less than 20 out of 1,300 flights left the airport on Sunday (19th December).
It was a flight that would have seen me delivered to Madison, Wisconsin, to spend Christmas with my boyfriend. I woke early anticipating delays after the snow on Saturday and called my airline, American Airlines, who confirmed my flight would be leaving. Nervously, I set off catching the Heathrow Express from Paddington and arrived to the terminal 3 to find myself in a scene of absolute pandemonium. Loaded with a suitcase and bags I set about the task of finding the check in desk and very quickly realised this would be impossible. The terminal hall was packed wall to wall with forlorn looking travellers, the air reverberating with frustrated and miserable voices.
Trying to reach my check desk, I passed another, (Cathay Pacific), and heard an angry cry from one of the passengers, “I’ve been here for 2 days, what are you going to do for me?”, and he was not alone. Everywhere were small islands of people surrounded by their luggage and huddled under silver blankets, exhausted, sleep deprived and hungry. With very few restaurants, save a few coffee shops slowly emptying of sandwiches and a bar (which was full at 7 am) food was hard to come by, and expensive at that.

As I eventually neared the American Airlines check in desk, I could see hundreds of people queuing for stations, all of which were empty. A ray of hope shone down when I received a text from the Heathrow Flying Messenger service informing me that my flight would indeed be leaving on time at 10.15 am, this was at 7.30am. I searched frantically for a member of staff and found none. With no way to reach the check in desk past the hordes of people and no staff to ask for help, panic took hold. After a painstaking 3 hours of waiting, I saw a stream of airport staff, (some of the first I had seen in the hall), leaving. When I asked one of them what was going on, they said simply, “We’re going home. There’s nothing flying”. Soon after came an announcement stating all American Airlines flights were cancelled for the day and passengers should leave the terminal. This was closely followed by announcements from numerous airlines, filling the hall with disappointment and anguish.
Distraught, I was comforted by a woman from a group which had travelled from Staffordshire and had no choice but to wait at the airport. When I asked her where she was supposed to be flying she tearfully replied, “We were flying to New York to board the Queen Mary cruise. It was the trip of a lifetime; we’ve been saving for years”. It was at this time that I caught my first glimpse of an AA representative who was handing out flyers with little else but an 0845 number to call, which can cost as much as 40p from a mobile, surely the only option for most passengers at the airport.
I chose to travel home before rebooking my flight but found the Heathrow Express had been closed, leaving a further flux of passengers frustrated as all were forced to pack into the Underground. Finally I arrived home and had a pleasant 2 and a half hour hold time to talk to someone to change my flight, which has now been moved to the 24th December, a full 5 days after the original flight.
It is clear that stern questions will be asked of the British Airport Authorities. With only 5 inches of snow falling on Saturday, and none since, it seems inexplicable that the airport has taken so long to reopen. The lack of organisation and information for passengers will surely also come under fire, with much conflicting advice and great difficulty in contacting staff, both at and away from the airport. Heathrow have issued a statement on their website saying, “We are sorry for the disruption caused and will reflect carefully on the lessons we can learn and the steps we need to take to better prepare for these periods of poor weather”. Well lessons hard learned for their passengers this weekend. It is with a sense of slight deja vu I read this statement, as it seems to mirror closures at this time last year, when flights were also ground to a halt over a meager amount of snow. With airports around the world coping with these conditions day in day out, it is clear that BAA will need to take a long, hard look at their strategies, and a long hard look at those passengers let down by them this Christmas.

Sunday, 5 December 2010

First Post!

I'm starting up a blog with the basic premise of sharing ideas about science I find exciting and informative. I'll try to cover a range of topics, including news snippets, interesting facts and perhaps a few opinions thrown in there. Above all, science is about having fun and getting involved, so if you have any burning questions about science post a comment and I'll strive to answer them!
Just as a flavour of what's to come, here's a link to a guest post of mine on Joshua Howgego's blog about some awesome science experiments to try at home, enjoy!