̽��ֱ�� of Cambridge - Colin Humphreys

Cambridge spin-out starts producing graphene at commercial scale

sc604 — Tue, 12 Mar 2019 07:45:07 +0000

Paragraf is producing graphene ‘wafers’ and graphene-based electronic devices, which could be used in transistors, where graphene-based chips could deliver speeds more than ten times faster than silicon chips; and in chemical and electrical sensors, where graphene could increase sensitivity by a factor of more than 30. ̽��ֱ��company’s first device will be available in the next few months.

Graphene’s remarkable properties – stronger than steel, more conductive than copper, highly flexible and transparent – make it ideal for a range of applications. However, its widespread commercial application in electronic devices has been held back by the difficulties associated with producing it at high quality and at high volume. ̽��ֱ��conventional way of making large-area graphene involves using copper as a catalyst which contaminates the graphene, making it unsuitable for electronic applications.

Professor Sir Colin Humphreys from the Centre for Gallium Nitride in Cambridge’s Department of Materials Science and Metallurgy, along with his former postdoctoral researchers Dr Simon Thomas and Dr Ivor Guiney, developed a new way to make large-area graphene in 2015.

Using their method, the researchers were able form high-quality graphene wafers up to eight inches in diameter, beating not only other university research groups worldwide, but also companies like IBM, Intel and Samsung.

̽��ֱ��three researchers spun out Paragraf in early 2018. Thomas is currently the company’s CEO and Guiney is its Chief Technology Officer, while Humphreys, who has recently moved to Queen Mary ̽��ֱ�� of London, serves as Chair.

Paragraf has received £2.9 million in funding to support the development of its first commercial products and moved into premises in February 2018. ̽��ֱ��funding round was led by Cambridge Enterprise, the ̽��ֱ��’s commercialisation arm. Paragraf already employs 16 people and has filed eight patents.

“Paragraf has the potential to transform a wide range of industries, including electronics, energy and healthcare,” said Humphreys. “It will enable the basic science results achieved in laboratories worldwide using small graphene flakes to be commercially exploited in graphene-based devices and to realise the potential and benefits to society of graphene, the wonder material.”

̽��ֱ��original research was funded by the Engineering and Physical Sciences Research Council (EPSRC).

A recent ̽��ֱ�� of Cambridge spin-out company, Paragraf, has started producing graphene – a sheet of carbon just one atomic layer thick – at up to eight inches (20cm) in diameter, large enough for commercial electronic devices.

Paragraf has the potential to transform a wide range of industries, including electronics, energy and healthcare

Colin Humphreys

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Oldest recorded solar eclipse helps date the Egyptian pharaohs

sc604 — Mon, 30 Oct 2017 00:02:49 +0000

Using a combination of the biblical text and an ancient Egyptian text, the researchers were then able to refine the dates of the Egyptian pharaohs, in particular the dates of the reign of Ramesses the Great. ̽��ֱ��results are published in the Royal Astronomical Society journal Astronomy & Geophysics.

̽��ֱ��biblical text in question comes from the Old Testament book of Joshua and has puzzled biblical scholars for centuries. It records that after Joshua led the people of Israel into Canaan – a region of the ancient Near East that covered modern-day Israel and Palestine – he prayed: “Sun, stand still at Gibeon, and Moon, in the Valley of Aijalon. And the Sun stood still, and the Moon stopped, until the nation took vengeance on their enemies.”

“If these words are describing a real observation, then a major astronomical event was taking place - the question for us to figure out is what the text actually means,” said paper co-author Professor Sir Colin Humphreys from the ̽��ֱ�� of Cambridge’s Department of Materials Science & Metallurgy, who is also interested in relating scientific knowledge to the Bible.

“Modern English translations, which follow the King James translation of 1611, usually interpret this text to mean that the sun and moon stopped moving,” said Humphreys, who is also a Fellow of Selwyn College. “But going back to the original Hebrew text, we determined that an alternative meaning could be that the sun and moon just stopped doing what they normally do: they stopped shining. In this context, the Hebrew words could be referring to a solar eclipse, when the moon passes between the earth and the sun, and the sun appears to stop shining. This interpretation is supported by the fact that the Hebrew word translated ‘stand still’ has the same root as a Babylonian word used in ancient astronomical texts to describe eclipses.”

Humphreys and his co-author, Graeme Waddington, are not the first to suggest that the biblical text may refer to an eclipse, however, earlier historians claimed that it was not possible to investigate this possibility further due to the laborious calculations that would have been required.

Independent evidence that the Israelites were in Canaan between 1500 and 1050 BC can be found in the Merneptah Stele, an Egyptian text dating from the reign of the Pharaoh Merneptah, son of the well-known Ramesses the Great. ̽��ֱ��large granite block, held in the Egyptian Museum in Cairo, says that it was carved in the fifth year of Merneptah’s reign and mentions a campaign in Canaan in which he defeated the people of Israel.

Earlier historians have used these two texts to try to date the possible eclipse, but were not successful as they were only looking at total eclipses, in which the disc of the sun appears to be completely covered by the moon as the moon passes directly between the earth and the sun. What the earlier historians failed to consider was that it was instead an annular eclipse, in which the moon passes directly in front of the sun, but is too far away to cover the disc completely, leading to the characteristic ‘ring of fire’ appearance. In the ancient world, the same word was used for both total and annular eclipses.

̽��ֱ��researchers developed a new eclipse code, which takes into account variations in the Earth’s rotation over time. From their calculations, they determined that the only annular eclipse visible from Canaan between 1500 and 1050 BC was on 30 October 1207 BC, in the afternoon. If their arguments are accepted, it would not only be the oldest solar eclipse yet recorded, it would also enable researchers to date the reigns of Ramesses the Great and his son Merneptah to within a year.

“Solar eclipses are often used as a fixed point to date events in the ancient world,” said Humphreys. Using these new calculations, the reign of Merneptah began in 1210 or 1209 BC. As it is known from Egyptian texts how long he and his father reigned for, it would mean that Ramesses the Great reigned from 1276-1210 BC, with a precision of plus or minus one year, the most accurate dates available. ̽��ֱ��precise dates of the pharaohs have been subject to some uncertainty among Egyptologists, but this new calculation, if accepted, could lead to an adjustment in the dates of several of their reigns and enable us to date them precisely.

Reference
Colin Humphreys and Graeme Waddington. ‘Solar eclipse of 1207 BC helps to date pharaohs.’ Astronomy & Geophysics (2017). DOI: 10.1093/astrogeo/atx178.

Researchers have pinpointed the date of what could be the oldest solar eclipse yet recorded. ̽��ֱ��event, which occurred on 30 October 1207 BC, is mentioned in the Bible and could have consequences for the chronology of the ancient world.

If these words are describing a real observation, then a major astronomical event was taking place - the question for us to figure out is what the text actually means.

Colin Humphreys

Kevin Baird

Annular eclipse photographed at sunset in eastern New Mexico.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution-ShareAlike

Machine learning used to predict earthquakes in a lab setting

sc604 — Mon, 23 Oct 2017 00:28:01 +0000

̽��ֱ��team, from the ̽��ֱ�� of Cambridge, Los Alamos National Laboratory and Boston ̽��ֱ��, identified a hidden signal leading up to earthquakes and used this ‘fingerprint’ to train a machine learning algorithm to predict future earthquakes. Their results, which could also be applied to avalanches, landslides and more, are reported in the journal Geophysical Review Letters.

For geoscientists, predicting the timing and magnitude of an earthquake is a fundamental goal. Generally speaking, pinpointing where an earthquake will occur is fairly straightforward: if an earthquake has struck a particular place before, the chances are it will strike there again. ̽��ֱ��questions that have challenged scientists for decades are how to pinpoint when an earthquake will occur, and how severe it will be. Over the past 15 years, advances in instrument precision have been made, but a reliable earthquake prediction technique has not yet been developed.

As part of a project searching for ways to use machine learning techniques to make gallium nitride (GaN) LEDs more efficient, the study’s first author, Bertrand Rouet-Leduc, who was then a PhD student at Cambridge, moved to Los Alamos National Laboratory in New Mexico to start a collaboration on machine learning in materials science between Cambridge ̽��ֱ�� and Los Alamos. From there the team started helping the Los Alamos Geophysics group on machine learning questions.

̽��ֱ��team at Los Alamos, led by Paul Johnson, studies the interactions among earthquakes, precursor quakes (often very small earth movements) and faults, with the hope of developing a method to predict earthquakes. Using a lab-based system that mimics real earthquakes, the researchers used machine learning techniques to analyse the acoustic signals coming from the ‘fault’ as it moved and search for patterns.

̽��ֱ��laboratory apparatus uses steel blocks to closely mimic the physical forces at work in a real earthquake, and also records the seismic signals and sounds that are emitted. Machine learning is then used to find the relationship between the acoustic signal coming from the fault and how close it is to failing.

̽��ֱ��machine learning algorithm was able to identify a particular pattern in the sound, previously thought to be nothing more than noise, which occurs long before an earthquake. ̽��ֱ��characteristics of this sound pattern can be used to give a precise estimate (within a few percent) of the stress on the fault (that is, how much force is it under) and to estimate the time remaining before failure, which gets more and more precise as failure approaches. ̽��ֱ��team now thinks that this sound pattern is a direct measure of the elastic energy that is in the system at a given time.

“This is the first time that machine learning has been used to analyse acoustic data to predict when an earthquake will occur, long before it does, so that plenty of warning time can be given – it’s incredible what machine learning can do,” said co-author Professor Sir Colin Humphreys of Cambridge’s Department of Materials Science & Metallurgy, whose main area of research is energy-efficient and cost-effective LEDs. Humphreys was Rouet-Leduc’s supervisor when he was a PhD student at Cambridge.

“Machine learning enables the analysis of datasets too large to handle manually and looks at data in an unbiased way that enables discoveries to be made,” said Rouet-Leduc.

Although the researchers caution that there are multiple differences between a lab-based experiment and a real earthquake, they hope to progressively scale up their approach by applying it to real systems which most resemble their lab system. One such site is in California along the San Andreas Fault, where characteristic small repeating earthquakes are similar to those in the lab-based earthquake simulator. Progress is also being made on the Cascadia fault in the Pacific Northwest of the United States and British Columbia, Canada, where repeating slow earthquakes that occur over weeks or months are also very similar to laboratory earthquakes.

“We’re at a point where huge advances in instrumentation, machine learning, faster computers and our ability to handle massive data sets could bring about huge advances in earthquake science,” said Rouet-Leduc.

Reference:
Bertrand Rouet-Leduc et al. ‘Machine Learning Predicts Laboratory Earthquakes.’ Geophysical Research Letters (2017). DOI: 10.1002/2017GL074677

A group of researchers from the UK and the US have used machine learning techniques to successfully predict earthquakes. Although their work was performed in a laboratory setting, the experiment closely mimics real-life conditions, and the results could be used to predict the timing of a real earthquake.

This is the first time that machine learning has been used to analyse acoustic data to predict when an earthquake will occur.

Colin Humphreys

United Nations Development Programme

Haiti Earthquake

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution-Noncommerical

̽��ֱ��Penultimate Supper?

bjb42 — Sun, 17 Apr 2011 04:00:10 +0000

̽��ֱ��Last Supper, which millions of Christians will mark on Maundy Thursday as Easter begins this week, actually took place on a Wednesday, a groundbreaking study is to reveal.

̽��ֱ��dramatic claim is the principal conclusion of a new book in which Professor Sir Colin Humphreys, a scientist at the ̽��ֱ�� of Cambridge, argues that he has solved what the eminent Biblical scholar, F. F. Bruce, once described as “the thorniest problem in the New Testament”.

Researchers have puzzled for centuries over the precise nature and timing of Jesus’ final meal with his disciples. At the heart of the problem is an apparently fundamental contradiction in the Gospels. Matthew, Mark and Luke all assert that the Last Supper was a meal marking the start of the Jewish festival of Passover. John, by contrast, says that it took place before the Passover began.

Writing in ̽��ֱ��Mystery Of ̽��ֱ��Last Supper, Professor Humphreys proposes a new solution, based on a combination of Biblical, historical and astronomical research. ̽��ֱ��core of his argument is that Jesus used a different calendar to that conventionally accepted by Jews at the time. According to this different system, the Last Supper would have fallen on the Wednesday, and not the Thursday, of what is now called Holy Week.

“Whatever you think about the Bible, the fact is that Jewish people would never mistake the Passover meal for another meal, so for the Gospels to contradict themselves in this regard is really hard to understand,” Professor Humphreys said.

“Many Biblical scholars say that, for this reason, you can’t trust the Gospels at all. But if we use science and the Gospels hand in hand, we can actually prove that there was no contradiction. In addition, this research seems to present a case for finally introducing a fixed date for Easter.”

̽��ֱ��new study is based on earlier research which Professor Humphreys carried out with the Oxford astrophysicist, Graeme Waddington, in 1983. This identified the date of Jesus’ crucifixion as the morning of Friday, April 3^rd, AD 33 – which has since been widely accepted by other scholars as well.

For Professor Humphreys, who only studies the Bible when not pursuing his day-job as a materials scientist, this presented an opportunity to deal with the equally difficult issue of when (and how) Jesus’ Last Supper really took place.

Aside from the basic contradiction posed by three Gospels’ reference to a Passover meal, all four present a logistical problem. If, according to the Holy Week model, the Last Supper was on a Thursday, then for Jesus to have been executed on a Friday morning, a large number of events had to take place overnight: These included his arrest, interrogation, and separate trials before the Jewish court (the Sanhedrin), Pontius Pilate and Herod.

Even for the alleged son of God, squeezing all of this in would have been an ask. In addition, it was against Jewish law for the Sanhedrin to meet at night. Suspiciously, all of the Gospels also omit to mention what happened on the Wednesday of Holy Week.

If Jesus died on April 3^rd, the standard Jewish calendar of AD33 would have placed his crucifixion on the 14^th day of the Jewish month of Nisan. ̽��ֱ��Passover meal, however, falls on the 15^th – which supports John’s account, but not those of the other Gospels.

Humphreys is not the first researcher to suggest that Jesus might, therefore, have been using a different calendar altogether. Most recently, the Pope suggested in 2007 that Jesus used the solar calendar of the Qumran community, which was probably employed by a Jewish sect called the Essenes and is described in the Dead Sea Scrolls. As Humphreys shows, however, when the date of Passover is calculated using this calendar, it would have fallen a week later, after both Jesus’ death and resurrection.

For the first time, Humphreys investigates the possibility that a third calendar was in use. ̽��ֱ��official Jewish calendar at the time of Jesus’ death was that still used by Jews today; a lunar system in which days run from sunset to sunset. This was developed during the Jewish exile in Babylon in the 6^th century BC.

Beforehand, however, the Jews had a different system. This is referred to in the Book of Exodus in the Old Testament, when God instructs Moses and Aaron to start their year at the time of the Exodus from Egypt. Humphreys argues that this system would have been an adaptation of the Egyptian lunar calendar (confusingly one of two systems used by the Egyptians), in which the start of the year was redated to occur in the spring.

There is, he adds, extensive evidence to suggest that this survived as more than a remnant into Jesus’ time. Not all Jews were exiled in Babylon. Those who remained retained the old system of marking the days, and by the 1^st century AD, groups such as the Samaritans, Zealots, some Galileans and some Essenes (who may well have provided Jesus with the accommodation used for the Last Supper), were still abiding by the old system.

Under this, pre-exilic, calendar, Passover always fell earlier and the days were marked from sunrise to sunrise, not sunset to sunset. In AD33, the Passover meal would have occurred on the Wednesday of Holy Week, which presuming Jesus, Matthew, Mark and Luke all used pre-exilic dating, and John does not, resolves both the contradictions in the Gospels and means that the events they describe could have taken place on Thursday, at a more leisurely pace and in accordance with Jewish law.

Jesus also had the motivation to use the earlier dating system developed by Moses. ̽��ֱ��Gospels are littered with examples of him presenting himself as the new Moses. According to Luke, he even said during the Last Supper that he was making a “new covenant” with his disciples – a direct reference to the covenant made between God and the Jewish people through Moses in Exodus.

In many ways, therefore, Humphreys suggests that the Last Supper was a positioning exercise on Jesus’ part, which gave him ample reason to use the pre-exilic calendar. “Jesus was identifying himself explicitly with Moses,” he said. “He was setting himself up as a deliberate parallel. He then died on Nisan 14^th, just as the Passover lambs were being slain according to the official Jewish calendar as well. These are deep, powerful symbolisms – and they can be based on objective, historical evidence.”

̽��ֱ��Mystery of the Last Supper, by Professor Sir Colin Humphreys, is published by Cambridge ̽��ֱ�� Press.

̽��ֱ��Last Supper of Jesus Christ was on the Wednesday, and not the Thursday, before his death, according to a new study which claims to have solved “the thorniest problem in the New Testament”.

If we use science and the Gospels hand in hand, we can prove there was no contradiction about the nature of the Last Supper.

Professor Colin Humphreys.

Wikimedia commons

Leonardo Da Vinci's depiction of the Last Supper

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

Cambridge makes Hay

bjb42 — Mon, 11 Apr 2011 09:16:17 +0000

̽��ֱ�� of Cambridge alumnus and Hay Festival director Peter Florence has invited the ̽��ֱ�� to contribute a third annual speaker series to the world-renowned Festival, held between May 27 and June 5.

̽��ֱ��Cambridge Hay series is a spin-off from the Cambridge Festival of Ideas, and features outstanding communicators from the Cambridge academic community.

Up to 5,000 people are expected to attend the talks and discussions in the Cambridge series and this year ̽��ֱ��Telegraph is the Festival’s media partner.

Highlights this year include philosopher Baroness Onora O'Neill debating the limits of toleration in today's society and Dr Amrita Narlikar on the rise of new powers Brazil, India and China and their impact on global governance. Dr Narlikar heads Cambridge's new Centre for Rising Powers.

India is one of the focuses for this year's Festival and Dr Kevin Greenbank and Dr Annamaria Motrescu will lead a session entitled “ ̽��ֱ��Reel Raj: cinefilm and audio archive from the Centre of South Asian Studies”. This includes remarkable footage from some of the almost 300 home movies in their collection which offer a unique glimpse of life in India and other parts of South Asia during the final days of the British Empire.

Hay audiences can also look forward to Dr Ha-Joon Chang on 23 myths of capitalism and Professor Tony Wrigley in conversation with George Monbiot, discussing a new look at the industrial revolution and the links between the industrial revolution and our current energy crisis. Professor Nicky Clayton will talk about her research on crow behaviour which was featured in a series of online films made available by the ̽��ֱ��.

And with an event which may appeal to adults and children alike, Cambridge ̽��ֱ�� Press Chief Executive Stephen Bourne will speak about the company’s decision to adopt a giant panda at the Chengdu Giant Panda Breeding Research Foundation in China – a bid to build closer working links with the country and to help protect the endangered species.

Other speakers include:

Dr Simon Mitton, on the books that have changed our view of the universe, from Alexandria to Cambridge
Professor Michael Lamb on children in the legal system
Professor Gerry Gilmore on whether science claims to know the unknowable
Professor Rosamond McKitterick on history, memory and ideas about the past
Dr Ulinka Rublack on dress codes in Renaissance Europe
Dr Clive Oppenheimer on eruptions that shook the world
Professor Simon Blackburn on the relationship between language and action, pragmatism, and practical reasoning.
Dr Rachel Polonsky on Molotov, one of Stalin's fiercest henchmen.

Nicola Buckley, currently Head of Community Affairs, said: “ ̽��ֱ�� ̽��ֱ�� of Cambridge is delighted to be contributing its speaker series to the Hay Festival once again. We welcome the Festival director’s vision to open up Cambridge research on historic and contemporary India, among many other topics, to the Hay audience, and we look forward to lively talks and debates.”

̽��ֱ��full line-up for the Cambridge series at the Hay Festival is:

Fri 27/5, 5.15pm

Professor Sir Colin Humphreys

Cambridge Series 1 - " ̽��ֱ��Mystery of the Last Supper: Reconstructing the Final Days of Jesus".

Reconciling conflicting Gospel accounts and scientific evidence, the distinguished Cambridge physicist reveals the exact date of the Last Supper in a definitive new timeline of Holy Week and offers a complete reassessment of the final days of Jesus.

Fri 27/5, 6.30pm Professor John Barrow

̽��ֱ��Book of Universes

̽��ֱ��mathematician encounters universes where the laws of physics can change from time to time and from one region to another, universes that have extra hidden dimensions of space and time, universes that are eternal, universes that live inside black holes, universes that end without warning, colliding universes, inflationary universes, and universes that come into being from something else – or from nothing at all.

Fri 27/5, 7.45pm Dr Simon Mitton

From Alexandria to Cambridge

̽��ֱ��historian of astronomy examines of Five Books That Changed Our View of the Universe: Ptolemy's Almagest, Copernicus' De Revolutionibus, Galileo's Siderius Nuncius and Dialogo, and Newton's Principia. A facsimile of the Copernicus manuscript will be displayed.

Sat 28/5, 2.30pm Professor Michael Lamb

Angels, Demons, Dunces

̽��ֱ��developmental forensic psychologist examines our inconsistent views of children in the legal system.

Sun 29/5, 2.30pm Dr Ha-Joon Chang

23 Things They Don't Tell You About Capitalism

̽��ֱ��economist turns all received wisdom about free markets, globalisation and the digital revolution on its head and offers an utterly compelling alternative. Chaired by Jesse Norman of the Treasury Select Committee.

Mon 30/5, 4pm Professor Tony Wrigley

Opening Pandora's Box: a New Look at the Industrial Revolution

All material production requires energy. All pre-industrial economies derived the bulk of their energy from agriculture. Production horizons were tightly bounded. ̽��ֱ��use of fossil fuel overcame this limitation. Chaired by George Monbiot.

Tues 31/5, 1130 Stephen Bourne

Panda-monium: social responsibility in China

Cambridge ̽��ֱ�� Press has adopted the young giant panda Jian Qiao at the Chengdu Research Foundation in China. Its CEO reports on the practicalities and symbolism of this new relationship, and we'll meet Jian Qiao on the big screen.

Tues 31/5, 1pm Professor Simon Blackburn

Practical Tortoise Raising

̽��ֱ��Philosopher explores the relationship between language and action, pragmatism, pluralism and practical reasoning.

Tues 31/5, 1pm Professor Clive Oppenheimer

Eruptions That Shook ̽��ֱ��World

̽��ֱ��volcanologist explores geological, historical and archaeological records to ask how volcanic eruptions have shaped the trajectory of human society through prehistory and history. He looks at the evidence for

volcanic cataclysm and considers how we can prepare ourselves for future catastrophes.

Tues 31/5, 5.30pm Dr Amrita Narlikar

̽��ֱ��Rise of New Powers and the Challenges of Global Trade Governance

No good deed goes unpunished: the WTO’s timely response to accommodate the new powers – Brazil, China, and India – at the heart of its decision-making has created new opportunities but also generated unanticipated new problems. What insights can be learnt about the rise of new powers within the WTO and in other multilateral organisations?

Tues 31/5, 7pm Dr Kevin Greenbank / Dr Annamaria Motrescu

̽��ֱ��Reel Raj: cinefilm and audio archive

An overview of the digital holdings of the Centre of South Asian Studies and their potential in the teaching of British and South Asian imperial history. Chaired by Hannah Rothschild.

Weds 1/6, 11.30am Professor Gerry Gilmore

Past, present and infinite future?

Was there anything before the beginning, why does science claim to know the apparently unknowable; where do I come from? What do we know about the infinite future?

Weds 1/6, 4pm Rev Dr John Polkinghorne

Quantum Theory

" ̽��ֱ��mathematician, theoretical physicist and priest explains the strange and exciting ideas that make the subatomic world so different from the world of the every day."

Thurs 2/6, 2.30pm Dr Ulinka Rublack

Dressing Up: Cultural identity in Renaissance Europe

Historian Dr Rublack will show why clothes made history and history can be about clothes. Her research imagines the Renaissance afresh by considering people´s appearances: what they wore, how this made them move, what images they created, and how all this made people feel about themselves.

Thurs 2/6, 5.30pm Dr Rachel Polonsky

Molotov's Magic Lantern

A luminous, original and unforgettable exploration of a country and its literature, viewed through the eyes of Vyacheslav Molotov, one of Stalin's fiercest henchmen.

Fri 3/6, 2.30pm Professor Nicky Clayton

̽��ֱ��Ape On Your Bird Table

Crows are as smart as apes. They manufacture tools, they are socially sophisticated, and they plan where to cache for tomorrow's breakfast. These findings have led to a re-evaluation of avian cognition, and resulted in a theory that intelligence evolved independently in apes and crows.

Sat 4/6, 2.30pm Professor Rosamond McKitterick

History, Memory and Ideas About the Past

̽��ֱ��historian focuses on uses of memory and the problems of the relation between memory and written, especially narrative and records of memory. Particular memories can also be exploited to reinforce an identity or even an ideology. Modern historians have distinguished between official and popular history and memory, as well as collective and individual manifestations and uses of memory. She will explore how helpful modern experience may be in interpreting the distant past. Case studies of historical narratives and epitaphs inscribed on stone from the early middle ages (c. 500-c.900) will serve to highlight both the kind of material with which an early medieval historian works, and its implications for historical knowledge and interpretation more generally.

Sun 5/6, 2.30pm Baroness Onora O'Neill

Is Toleration Still A Virtue?

̽��ֱ��philosopher is an exacting examiner of great issues such as freedom of speech, assisted suicide and

stem cell research. Here she explores a fundamental assumption of liberal societies.

̽��ֱ��books that have changed our view of the Universe, eruptions that shook the world and Stalin's fiercest henchmen are just some of the themes that will be under discussion during the popular Cambridge Series at this year's Hay Literary Festival.

We welcome the vision to open up Cambridge research on historic and contemporary India, among many other topics, to the Hay audience.

Nicola Buckley

Peter Curbishley from Flickr

Hay Festival

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

Lighting for the 21st century

bjb42 — Sat, 01 Aug 2009 14:41:07 +0000

A revolution in lighting is under way. Thanks to advances in the technology, efficiency and cost of light-emitting diodes (LEDs), these devices are ready to take over in the very near future from conventional forms of incandescent lighting. ̽��ֱ��potential energy savings are huge: statistics from the US Department of Energy estimate that, by 2025, solid-state lighting such as LEDs could reduce the global amount of electricity used for lighting by 50% and, in the US alone, could eliminate 258 million metric tons of carbon emission, alleviate the need for 133 new power stations, and result in cumulative financial savings of over a hundred billion dollars. At the forefront of research underpinning this new lighting paradigm is a focus on the semiconductor gallium nitride (GaN) at the Cambridge Centre for Gallium Nitride in the Department of Materials Science and Metallurgy.

Why use GaN for LEDs?

LEDs based on GaN, which emits brilliant light when electricity is passed through it, are extremely energy efficient and long lasting. Traditional incandescent light bulbs are only 5% efficient at converting the electricity they consume into light, and, although low-energy light bulbs are 20% efficient, they contain hazardous mercury. Compare this with white GaN LEDs, which are already 30% efficient and have a target efficiency of 60%. GaN LEDs are also incredibly long lasting: an LED can burn for 100,000 hours. In practical terms, this means it only needs replacing after 60 years of typical household use.

In the UK, lighting consumes over a fifth of all the electricity generated at power stations, and GaN LEDs have the potential to reduce this figure by at least 50% and possibly by 75%.

̽��ֱ��Holy Grail for GaN is home and office lighting. Research directed at reducing manufacturing costs and improving the quality of light is bringing this goal closer.

Materials and devices

Research at the Cambridge Centre for Gallium Nitride, directed by Professor Colin Humphreys, the Director of Research in the Department of Materials Science and Metallurgy, stretches from fundamental materials studies through to applications and devices.

̽��ֱ��Centre has world-class GaN growth and characterisation facilities and has recently developed an innovative technique for growing GaN on large silicon wafers, instead of the more expensive sapphire wafers; this could deliver a tenfold reduction in LED manufacturing costs. ̽��ֱ��Centre is also working on improving the quality of light by coating blue LEDs with phosphors to produce white light. This will be improved still further through the use of novel phosphors produced by Professor Tony Cheetham in the Department of Materials Science and Metallurgy.

̽��ֱ��future

GaN LEDs have hit the market rapidly and are already widely used in flashlights and front bicycle lights, as backlighting for mobile phones and interior lighting in cars and aeroplanes, and even to light up landmarks such as the façade of Buckingham Palace and the length of the Severn Bridge. Looking ahead, the timescale for the widespread adoption of GaN LEDs in homes and offices is probably as short as 5–10 years.

Other applications also look promising. Research at the Centre is investigating the possibility of using GaN LEDs to mimic sunlight, which could have important benefits for sufferers of seasonal affective disorder (SAD). And other studies are investigating how UV LEDs, created by adding aluminium to GaN, could be used for killing bacteria and stopping viruses from reproducing, either to purify water in the developing world or to ‘sweep’ hospital wards to eradicate superbugs.

For more information, please contact the author Professor Colin Humphreys (colin.humphreys@msm.cam.ac.uk) at the Cambridge Centre for Gallium Nitride. ̽��ֱ��Centre’s research is funded by the Engineering and Physical Sciences Research Council (EPSRC), the Technology Strategy Board (TSB), Aixtron Ltd, Sharp Electronics Europe, QinetiQ, Forge Europa, Philips, Imago Scientific Instruments and RFMD (UK) Ltd, and is performed in collaboration with the ̽��ֱ�� of Manchester and Sheffield Hallam ̽��ֱ��.

A remarkable light-emitting material, gallium nitride, could slash electricity consumption, purify water and kill superbugs.

In the UK, lighting consumes over a fifth of all the electricity generated at power stations, and GaN LEDs have the potential to reduce this figure by at least 50% and possibly by 75%.

Colin Humphreys

Green LEDs

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

‘Magic’ lights to slash household electricity use

bjb42 — Wed, 28 Jan 2009 00:00:00 +0000

̽��ֱ��new LEDs use Gallium Nitride (GaN), a man-made semiconductor that emits a brilliant bright light but uses very little electricity. Until now high production costs have made GaN lighting too expensive for widespread use in homes and offices.

̽��ֱ��Cambridge ̽��ֱ�� Centre for Gallium Nitride, with funding from the Engineering and Physical Sciences Research Council (EPSRC), has developed a new way of making GaN which could produce LEDs for a tenth of current prices.

̽��ֱ��new technique grows GaN on silicon wafers, which achieves a 50% improvement in cost and efficiency on previous approaches to grow GaN in labs on expensive sapphire wafers, used since the 1990s.

Based on current results, GaN LED lights in every home and office could cut the proportion of UK electricity used for lights from 20% to 5%. A reduction equivalent to the output of eight power stations.

A GaN LED can burn for 100,000 hours and therefore, on average, only needs replacing after 60 years. And, unlike currently available energy-saving bulbs, GaN LEDs do not contain mercury eliminating the environmental problems posed by their disposal. GaN LEDs also have the advantage of turning on instantly and being dimmable.

Professor Colin Humphreys, lead scientist on the project said: "This could well be the holy grail in terms of providing our lighting needs for the future. We are very close to achieving highly efficient, low cost white LEDs that can take the place of both traditional and currently available low-energy light bulbs. That won't just be good news for the environment, it will also benefit consumers by cutting their electricity bills."

GaN LEDs, used to illuminate landmarks like Buckingham Palace and the Clifton Suspension Bridge, are also appearing in camera flashes, mobile phones, torches, bicycle lights and interior bus, train and plane lighting.

Parallel research is also being carried out into how GaN lights could mimic sunlight to help 3m people in the UK with Seasonal Affective Disorder (SAD).

Ultraviolet rays made from GaN lighting could also aid water purification and disease control in developing countries, identify the spread of cancer tumours and help fight hospital 'super bugs'.

A new way of making LEDs could see household lighting bills reduced by up to 75% in five years time, thanks to research at Cambridge ̽��ֱ��.

We are very close to achieving highly efficient, low cost white LEDs that can take the place of both traditional and currently available low-energy light bulbs.

Professor Colin Humphreys

nao904 from Flickr

LED

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

‘Super’ superalloys: hotter, stronger, for even longer

ns480 — Mon, 01 Sep 2008 13:14:53 +0000

A team of over a dozen researchers at the Rolls-Royce Materials UTC in the Department of Materials Science and Metallurgy has been studying the properties of nickel-base superalloys with the aim of obtaining the very best from their performance. ‘Materials are subjected to incredible conditions in jet engines – the turbine blades, which have walls only a millimetre thick, are whizzing round at 10,000 rpm while gases over 1500ºC pass over their surface,’ explained Deputy Director Dr Howard Stone.

By improving the performance of materials used in these highly demanding environments, jet engines can be run at higher temperatures. And, because this reduces fuel consumption, increasing gas temperatures offers a direct method by which emissions from air travel can also be reduced. ̽��ֱ��Cambridge team conducts research into all aspects of the metallurgy of these materials, from understanding how their properties may be optimised, to ensuring their safety in service, to investigating why failures occur.

̽��ֱ��Cambridge Materials UTC was linked five years ago with complementary departments at the Universities of Swansea and Birmingham to form a UTP. ‘ ̽��ֱ��UTPs have been very much admired throughout the world, and other companies globally are beginning to emulate the model of having permanent research centres within universities,’ said senior academic Dr Cathie Rae. ‘It’s about building a relationship of trust between the researchers and the industrial partner to mutual benefit.’

With an eye on the future, the lab is now also working towards the development of novel materials to enable more efficient aeroengines to be realised. ‘We cover the longer range research area that Rolls-Royce needs,’ explained Director Professor Colin Humphreys, who masterminded the original UTC and leads the Cambridge UTP. ‘We’ve helped to develop new alloys that are currently flying in Rolls-Royce-powered aircraft and now we’re developing their successors – the alloys of the future – which will run hotter, stronger, for even longer.’

For more information, please visit www.msm.cam.ac.uk/UTC

Only a single class of engineering materials can withstand the extreme conditions deep within a jet aeroplane engine – the nickel-base superalloys.

It’s about building a relationship of trust between the researchers and the industrial partner to mutual benefit.

Dr Cathie Rae

Rolls-Royce

Engine

Rolls-Royce

Research is the foundation stone for the high-technology products that Rolls-Royce designs and develops for its extremely competitive aerospace, marine and energy businesses. Each market sector sets substantial economic, operational and environmental challenges that call for accurate, long-range, research-based, technology planning.

Rolls-Royce, in collaboration with its partners, spends around £800 million annually on research and development. Its research strategy embraces three ‘Visions’ addressing the 5-, 10- and 20-year timeframes, which broadly are devoted to technology validation, applied research and fundamental research, respectively.

A key element of the longer-range Vision 10 and Vision 20 programmes is the network of Rolls-Royce-supported ̽��ֱ�� Technology Centres (UTCs). Over the past 18 years, some 29 UTCs (20 in the UK, the remainder in Europe, USA and Asia) have been carefully selected as the very best in their fields to address critical technical areas as diverse as materials, noise, combustion, aerodynamics and manufacturing technology. In cases where UTCs are highly complementary in their research focus, they have been linked together to form ̽��ֱ�� Technology Partnerships (UTPs).

̽��ֱ�� ̽��ֱ�� of Cambridge, with which Rolls-Royce has deep and long-established research links, has played a key role in the UTC network through three research programmes:

̽��ֱ��Cambridge ̽��ֱ�� Gas Turbine Partnership (UGTP) includes the world-renowned Whittle Laboratory and over 80 projects, such as the Environmentally Friendly Engine (see panel), whose collective purpose is to provide an integrated approach to gas turbine fluid mechanics and thermodynamics.
̽��ֱ��Materials UTC in the Department of Materials Science and Metallurgy conducts research into high-temperature superalloys used in the hottest components of gas turbine engines (see panel).
̽��ֱ��Engineering Design Centre (EDC) in the Department of Engineering has provided the Engineering Knowledge Management UTC of a wider UTP for Design. ̽��ֱ��project addressed the need to capture, store and retrieve engineering knowledge to improve design processes.

̽��ֱ��UTCs and UTPs are highly regarded as models for effective industrial– academic collaborative research. Their long-term nature and real-world challenges bring mutual benefits: Rolls-Royce finds solutions to complex technical challenges; the universities gain an ongoing five-year stability of funding and a greater depth and quality to their academic research; and the science base is broadened by developing a strong pool of highly skilled engineers and scientists.

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes