Tag Archives: PhD

Reasons for publishing scientific papers

A few months ago I wrote about how we are drowning in information as a result of the two million papers published in journals every year [see ‘We are drowning in information while starving for wisdom‘ on January 20th, 2021]. As someone who has published about 10 papers each year for the last couple of decades, including three this year already, I feel I should provide some explanation for continuing to contribute to the deluge of papers. I think there are four main reasons for publishing scientific papers. First, to report a discovery – a new contribution to knowledge or understanding.  This is the primary requirement for publication in a scientific journal but the significance of the contribution is frequently diminished both by the publisher’s and author’s need to publish which leads to many papers in which it is hard to identify the original contribution. The second reason is to fulfil the expectations or requirements of a funding agency (including your employer); I think this was probably the prime driver for my first paper which reported the results of a survey of muskoxen in Greenland conducted during an expedition in 1982. The third reason is to support a promotion case, either your own or one of your co-authors; of course, this is not incompatible with the reporting original contributions to knowledge but it can be a driver towards small contributions, especially when promotion committees consider only the quantity and not the quality of published papers. The fourth reason is to support the careers of members of the research team; in some universities it is impossible to graduate with a PhD degree in science and engineering without publishing a couple of papers, although most supervisors encourage PhD students to publish their work in at least one paper before submitting their PhD thesis, even when it is not compulsory. Post-doctoral researchers have a less urgent need to publish unless they are planning an academic career in which case they will need a more impressive publication record than their competitors. Profit is the prime reason for most publishers to publish papers.  Publishers make more money when they sell more journals with more papers in them which drives the launch of new journals and the filling of journals with more papers; this process is poorly moderated by the need to ensure the papers are worth reading.  It might be an urban myth, but some studies have suggested that half of published papers are read only by their editor and authors.  Thirty years ago, my PhD supervisor, who was also my mentor during my early career as an academic, already suspected this lack of readers and used to greet the news of the publication of each of my papers as ‘more stuffing for your chair’.


Patterson, E.A., 1984, ‘Sightings of Muskoxen in Northern Scoresby Land, Greenland’, Arctic, 37(1): 61-63

Rose Eveleth, Academics write papers arguing over how many people read (and cite) their papers, Smithsonian Magazine, March 25th, 2014.

Image: Hannes Grobe, AWI, CC BY-SA 2.5 <https://creativecommons.org/licenses/by-sa/2.5&gt;, via Wikimedia Commons.

Seeing things with nanoparticles

Photograph showing optical microscope and ancilliary equipment set up on an optical benchLast week brought excitement and disappointment in approximately equal measures for my research on tracking nanoparticles [see ‘Slow moving nanoparticles‘ on December 13th, 2017 and ‘Going against the flow‘ on February 3rd, 2021]. The disappointment was that our grant proposal on ‘Optical tracking of virus-cell interaction’ was not ranked highly enough to receive funding from Engineering and Physical Sciences Research Council. Rejection is an occupational hazard for academics seeking to win grants and you learn to accept it, learn from the constructive criticism and look for ways of reworking the ideas into a new proposal. If you don’t compete then you can’t win. The excitement was that we have moved our apparatus for tracking nanoparticles into a new laboratory, which has been set up for it, so that we can start work on a pilot study looking at the ‘Interaction of bacteria and viruses with cellular and hard surfaces’.  We are also advertising for a PhD student to start in September 2021 to work on ‘Developing pre-clinical models to optimise nanoparticle based drug delivery for the treatment of diabetic retinopathy‘.  This is an exciting development because it represents our first step from fundamental research on tracking nanoparticles in biological media towards clinical applications of the technology. Diabetic retinopathy is an age-related condition that threatens your sight and currently is managed by delivery of drugs to the inside of the eye which requires frequent visits to a clinic for injections into the vitreous fluid of the eye.  There is potential to use nanoparticles to deliver drugs more efficiently and to support these developments we plan that the PhD student will use our real-time, non-invasive, label-free tracking technology to quantify nanoparticle motion through the vitreous fluid and the interaction of nanoparticles with the cells of the retina.


My Engineering Day

Photograph of roof tops and chimneys in Liverpool.Today is ‘This is Engineering’ day organised by the Royal Academy of Engineering to showcase what engineers and engineering really look like, celebrate our impact on the world and shift public perception of engineering towards an appreciation that engineers are a varied and diverse group of people who are critical to solving societal challenges.  You can find out more at https://www.raeng.org.uk/events/online-events/this-is-engineering-day-2020.  I have decided to contribute to ‘This is Engineering’ day by describing what I do on a typical working day as an engineer. 

Last Wednesday was like many other working days during the pandemic.  I got up about 7am went downstairs for breakfast in our kitchen and then climbed back upstairs to my home-office in the attic of our house in Liverpool [see ‘Virtual ascent of Moel Famau’ on April 8th, 2020].  I am lucky in that my home-office is quite separate from the living space in our house and it has a great view over the rooftops.  I arrived there at about 7.45am, opened my laptop, deleted the junk email, and dealt with the emails that were urgent, interesting or could be replied to quickly.  At around 8am, I closed my email and settled down to write the first draft of a proposal for funding to support our research on digital twins [see ‘Tacit hurdle to digital twins’ on August 26th, 2020].  I had organised a meeting earlier in the week with a group of collaborators and now I had the task of converting the ideas from our discussion into a coherent programme of research.  Ninety caffeine-fuelled minutes later, I had to stop for a Google Meet call with a collaborator at Airbus in Toulouse during which we agreed the wording on a statement about the impact our recent research efforts.  At 10am I joined a Skype call for a progress review with a PhD student on our dual PhD programme with National Tsing Hua University in Taiwan, so we were joined by his supervisor in Taiwan where it was 6pm [see ‘Citizens of the World’ on November 27th, 2019].  The PhD student presented some very interesting results on evaluating the waviness of fibres in carbon-fibre composite materials using ultrasound measurements which he had performed in our laboratory in Liverpool.  Despite the local lockdown in Liverpool due to the pandemic, research laboratories on our campus are open and operating at reduced occupancy to allow social distancing.

After the PhD progress meeting, I had a catch-up session with my personal assistant to discuss my schedule for the next couple of weeks before joining a MS-Teams meeting with a couple of colleagues to discuss the implications of our current work on computational modelling and possible future directions.  The remaining hour up to my lunch break was occupied by a conference call with a university in India with whom we are exploring a potential partnership.  I participated in my capacity as Dean of the School of Engineering and joined about twenty colleagues from both institutions discussing possible areas of collaboration in both research and teaching.  Then it was back downstairs for a half-hour lunch break in the kitchen. 

Following lunch, I continued in my role as Dean with a half-hour meeting with Early Career Academics in the School of Engineering followed by internal interviews for the directorship of one of our postgraduate research programmes.  At 3.30pm, I was able to switch back to being a researcher and meet with a collaborator to discuss the prospects for extending our work on tracking synthetic nanoparticles into monitoring the motion of biological entities such as viruses and bacteria [see ‘Modelling from the cell through the individual to the host population’ on May 5th 2020].  Finally, as usual, I spent the last two to three hours of my working day replying to emails, following up on the day’s meetings and preparing for the following day.  One email was a request for help from one of my PhD students working in the laboratory who needed a piece of equipment that had been stored in my office for safekeeping.  So, I made the ten-minute walk to campus to get it for her which gave me the opportunity to talk face-to-face with one of the post-doctoral researchers in my group who is working on the DIMES project [see ‘Condition-monitoring using infra imaging‘ on June 17th, 2020].  After dinner, my wife and I walked down to the Albert Dock and along the river front to Princes Dock and back up to our house.

So that was my Engineering Day last Wednesday!


Logos of Clean Sky 2 and EUThe DIMES project has received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 820951.  The opinions expressed in this blog post reflect only the author’s view and the Clean Sky 2 Joint Undertaking is not responsible for any use that may be made of the information it contains.

Poleidoscope (=polariscope + kaleidoscope)

A section from a photoelastic model of turbine disc with a single blade viewed in polarised light to reveal the stress distribution.Last month I wrote about the tedium of collecting data 35 years ago without digital instrumentation and how it led me to work on automation and digitalisation in experimental mechanics [see ‘35 years later and still working on a PhD thesis‘ on September 16th, 2020].  Thirty years ago, one of the leading methods for determining stresses in components was photoelasticity, which uses polarised light to generate fringe patterns in transparent components or models that correspond to the distribution of stress.  The photoelastic fringes can be analysed in a polariscope, of which the basic principles are explained in a note at the end of this post.  During my PhD, I took hundreds of black and white photographs in a polariscope using sheets of 4×5 film, which came in boxes of 25 sheets that you can still buy, and then scanned these negatives using a microdensitometer to digitise the position of the fringes.  About 15 years after my PhD, together with my collaborators, I patented the poleidoscope which is a combination of a polariscope and a kaleidoscope [US patents 6441972 & 5978087] that removes all of that tedium.  It uses the concept of the multi-faceted lens in a child’s kaleidoscope to create several polariscopes within a compound lens attached to a digital camera.  Each polariscope has different polarising elements such that photoelastic fringes are phase-shifted between the set of images generated by the multi-faceted lens.  The phase-shifted fringe patterns can be digitally processed to yield maps of stress much faster and more reliably than any other method.  Photoelastic stress analysis is no longer popular in mainstream engineering or experimental mechanics due to the simplicity and power of digital image correlation [see ‘256 shades of grey‘ on January 22nd, 2014]; however, the poleidoscope has found a market as an inspection device that provides real-time information on residual stresses in glass sheets and silicon wafers during their production.  In 2003, I took study leave for the summer to work with Jon Lesniak at Glass Photonics in Madison, Wisconsin on the commercialisation of the poleidoscope.  Subsequently, Glass Photonics have  sold more than 250 instruments worldwide.

For more information on the poleidoscope see: Lesniak JR, Zhang SJ & Patterson EA, The design and evaluation of the poleidoscope: a novel digital polariscope, Experimental Mechanics, 44(2):128-135, 2004

Note on the Basic principles of photoelasticity: At any point in a loaded component there is a stress acting in every direction. The directions in which the stresses have the maximum and minimum values for the point are known as principal directions. The corresponding stresses are known as maximum and minimum principal stresses. When polarised light enters a loaded transparent component, it is split into two beams. Both beams travel along the same path, but each vibrates along a principal direction and travels at a speed proportional to the associated principal stress. Consequently, the light emerges as two beams vibrating out of phase with one another which when combined produce an interference pattern.   The polarised light is produced by the polariser in the polariscope and the analyser performs the combination. The interference pattern is observed in the polariscope, and the fringes are contours of principal stress difference which are known as isochromatics. When plane polarised light is used black fringes known as isoclinics are superimposed on the isochromatic pattern. Isoclinics indicate points at which the principal directions are aligned to the polarising axes of the polariser and analyser.

Image: a section from a photoelastic model of turbine disc with a single blade viewed in polarised light to reveal the stress distribution.