School of Physics and Astronomy Newsletter 2012

Physics and Astronomy @Nottingham

Welcome

Big Bang Theory Nottingham student heads to Caltech to study black holes.

to your future

The wow factor World-leading lecturer inspires students with molecular imaging techniques.

Stargazing Live University’s astronomical activities featured on the BBC.

Giant Amyloid Spheurlites: the optical properties of these abnormally big aggregates are studied in the school to understand their role in diseases such as Alzheimer’s.

Welcome to the School of Physics and Astronomy

Scholarship update

Campus round-up

P2 Welcome

Scholarship update

Campus round-up

P3 Big Bang Theory

P4 World-leading lecturer

P5 Team building

P6 Getting published

Student profile

P7 Student exchange to Brazil

P8 Stargazing Live

Physics quiz triumph

• 66% per cent of this year’s physics freshers were awarded a Sir Peter Mansfield High-Achiever Scholarship, worth up to £1,000. • 70% of first-year physics students were awarded a cash scholarship meaning they achieved a 2:1 or first-class total mark in their end-of-year exams.

For more details of our scholarships, please see www.nottingham.ac.uk/physics and follow the links to “Study with us”, “Undergraduate” and “Scholarships and bursaries”.

The University of Nottingham is the most environmentally friendly campus on the planet, according to a new international league table.

The University achieved this status for University Park Campus, which is home to the School of Physics and Astronomy, because of its award-winning parkland campuses and the use of innovative architecture and sustainable design in building new facilities. With 330 acres of rolling parkland, beautiful period buildings and a large lake, University Park is considered to be one of the most attractive campuses in the country.

You may also be interested to know that University Park is right next door to the Elizabethan Wollaton Hall and Deer Park. It’s even going to have its time on the big screen – Wollaton Hall will appear as Wayne Manor in the new Batman film, The Dark Knight Rises, which is due to be released in the summer of 2012.

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Welcome

Scholarships Environment

In this edition of the newsletter we focus on some of the exciting activities undertaken by our undergraduate students. These include summer work experience placements in research groups in North and South America and, nearer to home, a visit to Nottingham by a prominent nanoscientist from the famous IBM labs in Zürich. Also, looking towards future employment, we should not forget the valuable experience gained by our third-year students when a team of recruitment specialists came to give training in the best way of approaching interviews and assessment days for professional careers.

We very much appreciate your interest in our school and hope to welcome you as a visitor to one of our open days or as a student.

Professor Richard Bowtell Head of the School of Physics and Astronomy

Sir Peter Mansfield is a physicist in the school and the winner of the 2003 Nobel Prize for Medicine.

Students by the boating lake on University Park Campus.

Astrophysics

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The California Institute of Technology, or Caltech as it’s known, has a legendary ring to it. Physicists know it as one of the leading centres for scientific research in the world, and it proudly boasts 31 Nobel Prize winners plus top spot in the 2011-12 Times Higher Education worldwide ranking of universities. The celebrated Richard Feynman made Caltech his home and of course, physicists and non-physicists alike know it is the workplace of fictional characters Sheldon Cooper, Leonard Hofstadter and friends, all unforgettable stars of the award-winning TV comedy The Big Bang Theory.

Enter fourth-year MSci Physics with Theoretical Physics student Stephane Mangeon: what greater place than Caltech to spend a summer vacation investigating colliding black holes? Departing on his birthday, Stephane found flying west had the advantage of making it “the longest of my life – literally!” After landing in Los Angeles, he travelled to Pasadena “along streets just too big to fit anywhere in Europe” and found “a completely different world with palm trees bordering every road, Californians jogging around the streets, interminable processions of luxury cars and of course the beautiful Caltech campus.”

Stephane’s project was in the field of extreme astrophysics. “I was working on a computer model of galaxy evolution through mergers, and more precisely on the behaviour of a binary supermassive black hole system, which is thought to result from the merger of two galaxies. This topic has been extensively studied in its latter phase, when two black holes collapse and emit gravitational waves. However, how the two black holes get to that stage, which was the focus of my research, is very uncertain.

Most of the project involved new computer languages and areas of physics I had never seen before. This is where the training you receive at Nottingham is a real help. The problems you face will always change, but what I have learnt in Nottingham is how to tackle them and how to rationally solve any problem life will throw at you, whether it be in pure research or the industrial sector.”

Black holes in collision – a Big Bang Theory?

Main image: Galaxy formation calculation. Image courtesy of NASA, Andrew Benson (Caltech) and the JWST Science Team (STScI). Above: The Cahill Center for Astronomy and Astrophysics at Caltech, where MSci Physics with Theoretical Physics student Stephane Mangeon spent his summer vacation.

In March, the school was delighted to welcome Dr Leo Gross, a world-leading expert in single-atom manipulation and high-resolution molecular imaging. Leo, who is a research scientist at the IBM Research Labs in Zürich, has made ground-breaking contributions to our understanding of the fundamental atomic and molecular building blocks of matter, including the ability to manipulate individual atoms and molecules. He was in Nottingham to deliver a lecture to students as part of the school’s Frontiers in Physics masterclass series. Leo’s lecture, “Atomic Manipulation and High-Resolution Imaging with Scanned Probe Microscopes”, was extremely popular and attracted enough people to fill the 350-seat lecture theatre.

Leo’s group at IBM holds the record for the highest-resolution image of a single molecule yet recorded. Not only can the individual atoms comprising a pentacene molecule be seen in the atomic force microscope image above, but the bonds between atoms are resolved. The image bears a striking similarity to ball-and-stick models of the pentacene molecule used by university lecturers and will itself be featured in undergraduate textbooks in the not-too-distant future.

In his masterclass, Leo also impressed the audience with the results of a series of elegant state-of-the-art experiments involving, for example, charging of a single atom and picking up an individual molecule.

The lecture made a big impression on Jasmine Rivett, now a third-year MSci Physics with Nanoscience student. She said: “It was inspiring to hear from a leading researcher in the field of scanning probe microscopy and fascinating to see the

atomic resolution images obtained by their research group at IBM.” Jasmine went on to take up a summer studentship in the Nanoscience Group, one of the school’s research groups, to work on precisely the type of exciting small-scale science that Leo popularised in his talk: imaging and manipulating single molecules.

Students wowed by world-leading lecturer

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People

Above left: Using equipment in the school’s teaching laboratories, undergraduates are able to put into practice the techniques for recording images with atomic resolution as described by world-leading lecturer Leo Gross. Above right: This AFM image of pentacene shows the bonds between the atoms. Below: The AFM image is recorded by measuring the tiny forces between the atom on the tip of the probe and the atoms on the molecule.

The recruitment process for most professional jobs involves an assessment day at some stage. To give our graduates some experience of what to expect, the School of Physics and Astronomy employed Totem Development, a firm that runs such events for major companies like O2, to come in and assess our third-year students.

A team of assessors from Totem arrived last September and the entertainment commenced. Firstly the candidates were divided into teams. Friendship groups were deliberately broken up by the Totem team: after all, you’ll have no friends with you on the real day! After a short briefing each team spent the morning learning how to cooperate by performing a series of short, well-defined project briefs. After reviewing how this went and discussing the strengths and weaknesses of their team, the afternoon was spent attempting a selection of more advanced projects such as building a device that added two numbers in binary notation.

During the day the Totem staff closely observed all the students, as they would on a real selection event, and gave targeted feedback.

Totem were impressed by the ability of our cohort and complimented their innovative approach and willingness to think outside the box.

For their part, our students enjoyed a challenging day, gaining much valuable experience. Their feedback was very positive and we intend to run a mock assessment day again next year.

Team building

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Team building

Students working on a group project during a mock assessment.

A few tips from Totem

Obviously applying for a graduate job is still a fair way off, but these are useful hints for when you do come to think about it.

1) Get involved You don’t have to be the leader of the group, or even the loudest, but if you don’t contribute anything, your assessors won’t have anything to assess.

2) It’s not the winning or the losing but the taking part Assessment days aren’t really about building a newspaper tower, solving puzzles or guiding a blindfolded colleague around a course. What assessors are interested in is the process you go through to get to your result. They want to see you communicating with others, sharing your part of the team’s workload, contributing ideas to discussions and how you work out solutions that are not immediately obvious.

3) Give yourself the best chance Assessments can be long and demanding – they typically last at least a day and sometimes as many as three. Make sure you eat and drink plenty all day because if you’re hungry or dehydrated you won’t perform at your best. Get plenty of sleep the night before too. And if you are there for more than one day, don’t be the last person in the bar!

Getting publishedThe thrill of seeing your name on your first scientific publication is probably one you will always remember, especially when that comes about as a result of your undergraduate project. In some cases, like that of MSci Physics graduate David Farmer, it can determine the direction of your future career.

“The exciting thing about the Sessile Droplet project in my fourth year was that I had a chance to investigate a problem that had never been attempted before.

“A laser beam was shone through a sessile (on a surface) droplet onto a photodiode and the droplet was induced to undergo a small mechanical vibration. The output of the photodiode enabled us to record the resonant frequency. A potential application is in fuel injection where knowing the resonant frequency helps when trying to break the droplets up and maximise the surface area of the liquid for combustion. Also, understanding the behaviour of liquid drops on surfaces is important to developing new materials in the burgeoning field of nanotechnology.

“The fact that my MSci degree was capped off by a paper being published in such a well-respected journal as Langmuir was a real bonus. It was a new experience being involved in a piece of work that underwent close scrutiny by internationally recognised referees! Given the fun and satisfaction I’d had working in the laboratory, I was keen to continue in research and study for a PhD and started doing so in September.”

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Student news

Published: June 17, 2011

r 2011 American Chemical Society 9367 dx.doi.org/10.1021/la201984y | Langmuir 2011, 27, 9367–9371

ARTICLE

pubs.acs.org/Langmuir

Contact Angle Dependence of the Resonant Frequency of SessileWater DropletsJames S. Sharp,* David J. Farmer, and James Kelly

School of Physics and Astronomy and Nottingham Nanotechnology and Nanoscience Centre, University of Nottingham,University Park, Nottingham, NG7 2RD, United Kingdom

bS Supporting Information

’ INTRODUCTION

Resonant vibrations of liquid droplets have received a sig-nificant amount of recent scientific interest. Studies of thebehavior of isolated liquid droplets date back to the times ofLord Rayleigh.1 However, much of the experimental and theore-tical work that was performed on the resonant vibrations ofdroplets appears to have initially beenmotivated by studies of theeffects of vibration on the formation of high purity crystals underzero gravity conditions.2�4 A number of other potential applica-tions of vibrating droplets have also been identified, including thepossibility of using isolated droplets for electric field enhancedliquid�liquid extraction,2 electrospray synthesis of mixed oxideceramics, and for the measurement of surface tension2,5 andcontact angles.6 This has led to a host of extremely elegantexperiments involving the study of, for example, acoustically andmagnetically levitated droplets.5 More recently, a renewed inter-est in this field has been generated by studies of the actuation ofsmall droplets on gradient energy surfaces.7�9 The idea beingthat these surfaces have a gradient in wettability that is caused byeither a chemical gradient or a gradient in topographical surfacestructure. When droplets are placed on these surfaces theydisplay a contact angle which is dependent upon their positionon the surface. Vibration of the droplets close to their resonantfrequencies enables them to sample nearby conformations andhas been shown to overcome pinning and contact angle hyster-esis effects and to facilitate the motion of the droplet down thesurface energy gradient.8 As a result of this renewed interest, anumber of authors have studied the resonant behavior of smallliquid droplets on vibrated surfaces2,6,10�12 and in electricallydriven sessile droplets.13,14 However, a serious limitation of these

studies has been that they are performed over a limited range ofcontact angles. In many cases, the experiments are restricted tostudies of droplets vibrating on a single surface and hence, onlyone possible contact angle value.

The theory of droplet vibrations is well developed and theearliest theoretical interpretation of the resonant behavior ofliquid droplets was provided by Lord Rayleigh and developedfurther by Chandrasekhar.1 More recent studies by Strani andSabetta3 and Smithwick and co-workers4 considered the vibra-tion of sessile droplets in a spherical bowl. Although this theorywas successfully extended to planar surfaces, determination ofthe contact angle dependent eigenvalues associated with thedifferent vibrational modes of the droplet involved solving thedeterminant of an infinitely large matrix. A more recently devel-oped model proposed by Noblin et al. offers a more intuitiveinterpretation of the origin of the vibrational modes of sessiledroplets.12 This theory considers the number of half integerwavelengths that can fit around the meridian profile length of adroplet and uses the dispersion relation for capillary waves in aninfinitely deep liquid bath to obtain an approximation for thefrequencies of the resonant vibrational modes.

Experimental work on sessile droplets has also been performedby a number of authors. For example, a range of studies have beenperformed on droplets that were either horizontally7,10,15 orvertically12,16 vibrated using a loudspeaker or surface acousticwave generator.6 Another method of driving the oscillations in

Received: April 11, 2011Revised: June 16, 2011

ABSTRACT: The resonant vibrations of small (microliter) sessile waterdroplets supported on solid substrates were monitored using a simple opticaldetection technique. A small puff of air was used to apply an impulse to thedroplets and their time dependent oscillations weremonitored by passing a laserbeam through the droplet and measuring the variations of the intensity of thescattered light using a simple photodiode arrangement. The resulting timedependent intensity changes were then Fourier transformed to obtain informa-tion about the vibrational frequencies of the droplets. The resonant frequenciesof droplets with masses in the range 0.005�0.03 g were obtained on surfaceswith water contact angles ranging from 12( 4� to 160( 5�. The contact angledependence of the resonant frequency of the droplets was found to be in goodagreement with a simple theory which considers standing wave states along themeridian profile length of the droplets.

MSci Physics graduate David Farmer working in his PhD lab. Below: In print!

Robin Murphy is studying for an MSci degree in Physics with European Language and he recently spent his third year studying at École Polytechnique Fédérale de Lausanne (EPFL), a top science and engineering university in Lausanne, Switzerland. As well as attending lectures, he conducted his third-year project there working on a particle detector for the Large Hadron Collider beauty (LHCb) experiment at CERN, which was just 40 minutes down the road from EPFL.

Student profile

Find out more about Robin’s experience at www.nottingham.ac.uk/ugvideos/robinmurphy

Scan the code to watch this video on your smartphone.

MSci Physics with European Language student Robin Murphy is working on an experiment called Optical Pumping of Rubidium which looks at the differences in energy levels of atoms in a rubidium vapour.

High vacuum experiencein Brazil

“The most rewarding aspect was getting to live in a different culture and experiencing physics in a new way...”

The stuff of dreams: arriving at a beautiful secluded beach after a long walk through a Brazilian rainforest with the opportunity to take a well-earned rest from all the hard work in the research lab. Add in blue skies, warm climate – it sounds like paradise!

This is just one of the memories that will stay with Victoria Hills forever. The International Association for the Exchange of Students for Technical Experience (IAESTE) scheme provides opportunities for foreign travel combined with summer work experience in a physics research group. Victoria, now in the fourth year of her MSci Physics degree, successfully applied for the chance to work on a plasma physics project in Sao Paulo, Brazil, during the summer of 2011.

“On arrival, a local student met me at Sao Paulo Airport and took me to get the bus to the small town where I would be living for the next nine weeks. My accommodation was in a republica, similar to the American sororities and fraternities.

I worked on a project that involved plasmas and high vacuum equipment. Some of my work was displayed at a conference elsewhere in Brazil which I was able to attend. This was a great experience and really confirmed my desire to undertake a research career in physics.

There were many differences with The University of Nottingham but one of the strangest things was the

chickens roaming around the campus for the sole purpose of eating the scorpions!

The time spent outside the university seemed even busier than the working hours. I loved the challenge of living in a different country – from gym classes where I couldn’t understand the instructor to accidentally ordering chilli bread from the local bakery. I explored many of the local restaurants and tasty local cuisine with my housemates.

The weekends were spent travelling with the other IAESTE students to popular sights like Sao Paulo and Rio de Janeiro as well as lesser-known ones like the little beach town of Paraty. While all these places were amazing experiences, and seeing sights like the famous Copacabana beach will stay with me forever, the most rewarding aspect was getting to live in a different culture and experiencing physics in a new way that could link into some of my activities back at Nottingham.”

The University of Nottingham is currently developing a whole range of links with Brazilian institutions, so in future there should be even more opportunities for our students to visit. For example, we are currently negotiating an agreement with the Brazilian National Observatory in Rio de Janeiro, which will include running one of our final-year undergraduate astronomy projects at the observatory.

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Brazil exchange

Generating a sample: the plasma is the purple haze.

Victoria Hills (far right) takes a break from her lab work and relaxes on a beach in Brazil.

Find out more about Robin’s experience at www.nottingham.ac.uk/ugvideos/robinmurphy

News

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Undergraduate course information is available at www.nottingham.ac.uk/ugstudy

For further information please contact:

School of Physics and Astronomy, University Park, NottinghamNG7 2RD

t: +44 (0)115 951 5165e: julie.kenney@nottingham.ac.ukw: www.nottingham.ac.uk/physics

If you require this publication in an alternative format, please contact us:t: +44 (0)115 951 4591e: alternativeformats@nottingham.ac.uk

Printed February 2012.

Each year students, researchers, and academic, technical and support staff from the School of Physics and Astronomy battle it out in the ever-popular school pub quiz. This year, 45 teams of four entered and came up with an array of imaginative names.

In a closely contested finish the undergraduate team Neils Bohring threatened to eclipse the eventual winners Quizi-Stellar Objects, a team of lecturers and researchers. In the end, Neils Bohring finished third and were delighted to claim a podium position.

Podium position for students at quiz night

Left: Simon Taylor, Garry Mudd, David Stefanyszyn and Daniel Wisniewski, of team Neils Bohring, took third place in the physics quiz night.

The BBC presented its highly successful Stargazing Live programmes in January 2012, with many millions watching the programmes and getting involved in local events. You might have taken part in them yourself!

The University of Nottingham ran astronomical activities in the city and also featured in the national broadcasts, with a live presentation from the Southern African Large Telescope (SALT) occurring while the instrument was being used to make observations for a research programme run jointly by the University’s School of Physics and Astronomy and School of Chemistry. These observations will, for the first time, allow us to understand the origins of the ghostly “blue luminescence” emitted by many galaxies.

Professor Michael Merrifield, from the School of Physics and Astronomy, said: “It’s brilliant to be a partner in a facility like SALT, giving us direct access to the kind of cutting-edge data that we need for our research-led undergraduate projects.”

Image: The Southern African Large Telescope (SALT) – image courtesy of Steve Potter, SALT.

Stargazing Live