SCIENCE AND TECHNOLOGY
Convenor Valerie Conniff email valerie@vconniff.plus.com
The meetings are a presentation on a scientific or technical topic from a speaker or audiovisual presentation, followed by a question and answer session. Visits to places of scientific interest are arranged, usually during the spring or summer.
The group meets on the 2nd Tuesday afternoon of every month, except August, at Mitchel Troy Village Hall from 2.30 to 4.00pm. There is no restriction on membership and the subscription of £10 per year covers hire costs and speaker expenses. Meetings are open to the general membership but a charge of £2 per meeting is requested to cover set up costs.
The group meets on the 2nd Tuesday afternoon of every month, except August, at Mitchel Troy Village Hall from 2.30 to 4.00pm. There is no restriction on membership and the subscription of £10 per year covers hire costs and speaker expenses. Meetings are open to the general membership but a charge of £2 per meeting is requested to cover set up costs.
Date of next meeting: To be confirmed
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A message from Val We are a friendly group and an important part of our meetings is the informal discussion over a cup of tea after we have finished questioning our invited Speaker. There is no limit on membership and I welcome new members to our Science and Technology Group. No personal technical qualification is required to join the group, just a keen interest in science and technology in its broadest sense. Best wishes Val Previous (Zoom) Meetings & Trips |
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Tues 9th June 2020 ZOOM Story of the Severn Bridge and its Impact on World Bridge Building
John Burrows is a local historian and photographer. He stressed that he is not a bridge engineer but became a bridge historian by accident. In a Zoom Meeting, attended by 29 members, he set out to provide evidence for two propositions:
First a description of what a suspension bridge is. Many early bridges were chain bridges, and while they may have inspired the design of suspension bridges, they are not suspension bridges. The essential difference is that whereas the route across a chain bridge follows a catenary, a suspension bridge has a level road deck. The weight of the deck is supported by vertical cables suspended from further cables which run between towers. This allows the span of the bridge to be up to eight times the height of the towers.
The first iron chain suspension bridge was built at Jacob’s Creek in Pennsylvania in 1801. It was designed by James Finley and was 21 metres long. Many well-known bridges followed in the years thereafter, including the Union Bridge in Berwick on Tweed (1820), Menai Bridge (1826) and designed by Thomas Telford, Brooklyn Bridge, New York (1883) and Golden Gate Bridge (1937) in California.
The need for a bridge over the Severn Estuary arose because the route from England involved either a ferry or a journey through Gloucester with the final stage being over a narrow bridge, itself of historic interest and still in use over the Wye, in the centre of Chepstow.
Significant in the design of the Severn Bridge is the fact that the estuary has the second highest tides in the world and this is accompanied by the speed the current in the ebb and flow. While the project was being considered it was, for the time, a very long span at just under a thousand metres. The other factor in all bridge design is the ability of the structure to withstand high winds. Where the Severn Bridge differs from earlier designs is how thin its deck is. Previous bridges had trusses which have significant windage. Testing of a trussed prototype design in a wind tunnel resulted in it being broken to pieces. This led to the aerofoil design of the Severn Bridge deck which survived the wind tunnel testing and which is such a feature in its appearance today.
The towers of the bridge are 125 metres in height and the span is 988 metres reflecting the design parameter of 8:1. The catenary cables holding up the deck, and to which the hangers are connected, were spun on site with over 8000 strands.
Many bridges around the world have followed the design of the Severn Bridge with the consequence that it is now well down the rankings for length of span. These include:
Bridge Location Span metres
Severn UK 988
Humber Bridge UK 1410
Akashi-Kaikyo Japan 1991
Cannakkale* Turkey 2023
*expected to be completed in 2021
The Severn Bridge is a Grade 1 listed structure. Given that 98% of Grade 1 listings are buildings rather than structures, and mainly old churches, this is clearly a highly regarded structure. In the view of the speaker the construction is such that, with appropriate maintenance, it could last for ever. Michael Bone
John Burrows is a local historian and photographer. He stressed that he is not a bridge engineer but became a bridge historian by accident. In a Zoom Meeting, attended by 29 members, he set out to provide evidence for two propositions:
- If just five suspension bridges, of the two thousand or more built in the last 200 years, were to be highlighted for their influence on the basic and continuing shape of suspension bridges, then it would be the first suspension bridge, Jacob’s Creek (1801), plus 4 others – one of which would be the Severn Bridge (1966)
- The Severn Bridge is one of the most beautiful bridges in the world.
First a description of what a suspension bridge is. Many early bridges were chain bridges, and while they may have inspired the design of suspension bridges, they are not suspension bridges. The essential difference is that whereas the route across a chain bridge follows a catenary, a suspension bridge has a level road deck. The weight of the deck is supported by vertical cables suspended from further cables which run between towers. This allows the span of the bridge to be up to eight times the height of the towers.
The first iron chain suspension bridge was built at Jacob’s Creek in Pennsylvania in 1801. It was designed by James Finley and was 21 metres long. Many well-known bridges followed in the years thereafter, including the Union Bridge in Berwick on Tweed (1820), Menai Bridge (1826) and designed by Thomas Telford, Brooklyn Bridge, New York (1883) and Golden Gate Bridge (1937) in California.
The need for a bridge over the Severn Estuary arose because the route from England involved either a ferry or a journey through Gloucester with the final stage being over a narrow bridge, itself of historic interest and still in use over the Wye, in the centre of Chepstow.
Significant in the design of the Severn Bridge is the fact that the estuary has the second highest tides in the world and this is accompanied by the speed the current in the ebb and flow. While the project was being considered it was, for the time, a very long span at just under a thousand metres. The other factor in all bridge design is the ability of the structure to withstand high winds. Where the Severn Bridge differs from earlier designs is how thin its deck is. Previous bridges had trusses which have significant windage. Testing of a trussed prototype design in a wind tunnel resulted in it being broken to pieces. This led to the aerofoil design of the Severn Bridge deck which survived the wind tunnel testing and which is such a feature in its appearance today.
The towers of the bridge are 125 metres in height and the span is 988 metres reflecting the design parameter of 8:1. The catenary cables holding up the deck, and to which the hangers are connected, were spun on site with over 8000 strands.
Many bridges around the world have followed the design of the Severn Bridge with the consequence that it is now well down the rankings for length of span. These include:
Bridge Location Span metres
Severn UK 988
Humber Bridge UK 1410
Akashi-Kaikyo Japan 1991
Cannakkale* Turkey 2023
*expected to be completed in 2021
The Severn Bridge is a Grade 1 listed structure. Given that 98% of Grade 1 listings are buildings rather than structures, and mainly old churches, this is clearly a highly regarded structure. In the view of the speaker the construction is such that, with appropriate maintenance, it could last for ever. Michael Bone
ZOOM meeting, May 12th 2020
The Enlightened Mr Parkinson
This month Dr Cherry Lewis, one of our group members, presented a fascinating glimpse into the life and achievements of James Parkinson, perhaps best known to us for the disease which bears his name. Throughout the course of her presentation Cherry revealed how very much more there was to learn about this man and how his scientific achievements were far ahead of his time.
James was born on April 11th 1755 in Hoxton, London, to a doctor, serving the inhabitants of this, at the time, small village. In due course James followed in his father’s footsteps through the stages of becoming first an apothecary then, after his father’s death in 1784, a surgeon in order to carry on the practice which was expanding rapidly due to the influx of workers into the area. He was a deeply religious man with a strong social conscience and was profoundly disturbed by the poverty of the workers who formed the majority of his patients. This led to his becoming politically active, joining societies such as the London Corresponding Society, and he wrote several political pamphlets criticising William Pitt and his government under the pseudonym “Old Hubert”. In 1794 he was examined under oath by the Privy Council concerning a plot to assassinate George III but no charges were brought.
Edward Jenner was a contemporary of James Parkinson and there was mutual respect between the two men. On hearing the success of Jenner’s vaccination treatment for smallpox, Parkinson set up vaccination clinics in London to relieve patients suffering from this deadly affliction. Parkinson published many medical books and papers throughout his career based on his observations of the patients he treated. The most notable of these is the publication in 1817 entitled “Essay on Shaking Palsy” which identified the symptoms, still used today, to diagnose the distinct condition known as Parkinson’s Disease. The paper did not receive great attention at that time but recognition came 60 years later from the French neurologist Jean-Martin Charcot , who first coined the term “Parkinson’s Disease”.
Parkinson’s “favourite hobby” was collecting fossils, having been inspired by seeing the surgeon John Hunter’s impressive collection. In 1804 he published the first edition of his book “Organic Remains of a Former World”, two later editions following in 1808 and 1811. They contain exquisite drawings executed with .meticulous attention to detail and made him famous in this field, many fossils being named in his honour. He was made a founder member of the Geological Society in 1807. There was a conflict between Parkinson’s religious beliefs and the scientific evidence provided by the fossils he found which he struggled to resolve, 50 years before Darwin met the same problem. Geology became a popular pastime from that period and Parkinson’s research into the origins of fossils laid the foundations for the science of palaeontology.
Towards the end of his life Parkinson was made the first recipient of the Royal College of Surgeons’ Gold Medal for “his splendid work on Organic Remains”. Parkinson died in 1824 and was buried in St Leonard’s Church in Shoreditch where he was also baptised and buried. The graveyard has been destroyed in urban development but a memorial plaque was put in the church in 1955 on the 200th anniversary of his birth.
Today April 11th is designated as World Parkinson Day in his honour. Valerie Conniff
The Enlightened Mr Parkinson
This month Dr Cherry Lewis, one of our group members, presented a fascinating glimpse into the life and achievements of James Parkinson, perhaps best known to us for the disease which bears his name. Throughout the course of her presentation Cherry revealed how very much more there was to learn about this man and how his scientific achievements were far ahead of his time.
James was born on April 11th 1755 in Hoxton, London, to a doctor, serving the inhabitants of this, at the time, small village. In due course James followed in his father’s footsteps through the stages of becoming first an apothecary then, after his father’s death in 1784, a surgeon in order to carry on the practice which was expanding rapidly due to the influx of workers into the area. He was a deeply religious man with a strong social conscience and was profoundly disturbed by the poverty of the workers who formed the majority of his patients. This led to his becoming politically active, joining societies such as the London Corresponding Society, and he wrote several political pamphlets criticising William Pitt and his government under the pseudonym “Old Hubert”. In 1794 he was examined under oath by the Privy Council concerning a plot to assassinate George III but no charges were brought.
Edward Jenner was a contemporary of James Parkinson and there was mutual respect between the two men. On hearing the success of Jenner’s vaccination treatment for smallpox, Parkinson set up vaccination clinics in London to relieve patients suffering from this deadly affliction. Parkinson published many medical books and papers throughout his career based on his observations of the patients he treated. The most notable of these is the publication in 1817 entitled “Essay on Shaking Palsy” which identified the symptoms, still used today, to diagnose the distinct condition known as Parkinson’s Disease. The paper did not receive great attention at that time but recognition came 60 years later from the French neurologist Jean-Martin Charcot , who first coined the term “Parkinson’s Disease”.
Parkinson’s “favourite hobby” was collecting fossils, having been inspired by seeing the surgeon John Hunter’s impressive collection. In 1804 he published the first edition of his book “Organic Remains of a Former World”, two later editions following in 1808 and 1811. They contain exquisite drawings executed with .meticulous attention to detail and made him famous in this field, many fossils being named in his honour. He was made a founder member of the Geological Society in 1807. There was a conflict between Parkinson’s religious beliefs and the scientific evidence provided by the fossils he found which he struggled to resolve, 50 years before Darwin met the same problem. Geology became a popular pastime from that period and Parkinson’s research into the origins of fossils laid the foundations for the science of palaeontology.
Towards the end of his life Parkinson was made the first recipient of the Royal College of Surgeons’ Gold Medal for “his splendid work on Organic Remains”. Parkinson died in 1824 and was buried in St Leonard’s Church in Shoreditch where he was also baptised and buried. The graveyard has been destroyed in urban development but a memorial plaque was put in the church in 1955 on the 200th anniversary of his birth.
Today April 11th is designated as World Parkinson Day in his honour. Valerie Conniff
14th April The Science of Scuba Diving Charles Emes ( Monmouth U3A)
This was our first meeting using Zoom to bring together 31'isolating' members to enjoy Charles' talk. The technology worked well with us being able to view the presentation slides in close up and Charles commentating even if out of our sight.
The main theme that came over was that one had to be aware of the risks involved so that appropriate measures could be put in place. Once this is done the rewards of diving in glorious settings to see fantastic sea life can be fully enjoyed.
Charles set the scene by describing the history, including the mistakes made, of diving. This led him on to describe the work of various researchers and the relevant laws of physics involved e.g. the key role of Boyle’s Law describing the relationship between pressure and volume. This led up to J. S. Haldane's 1908 report on 'The Prevention of Compressed Air Illness' from which the first dive tables were derived. In essence these give the diver key information on how long they can safely stay at particular depths. This in turn has now been computerised into a readily readable format that the diver has with them.
Divers now use Nitrox gas which is compressed air with 11% extra oxygen, the corresponding fall in nitrogen reducing the risk from nitrogen bubbles in the blood.
Charles then explained the factors that can get a diver into trouble. -- not monitoring depth and time properly, ascending too quickly, not observing the safety stop at 5m, and having residual nitrogen still in the blood from a previous dive. He then took us through a detailed look at the symptoms of, and any treatment, for a range of issues from decompression illness [think hyperbaric chamber], oxygen toxicity, hypercapnia, and ear barotrauma.
Safety involves being properly trained, diving within your limits, and always diving with a buddy.
At the end we were treated to a glorious set of images Charles has taken of life below the surface. Take your pick from dolphins, turtles, rays, fish, crabs and many others.
We zoomed in in every sense thanks to Charles. Jim Handley
This was our first meeting using Zoom to bring together 31'isolating' members to enjoy Charles' talk. The technology worked well with us being able to view the presentation slides in close up and Charles commentating even if out of our sight.
The main theme that came over was that one had to be aware of the risks involved so that appropriate measures could be put in place. Once this is done the rewards of diving in glorious settings to see fantastic sea life can be fully enjoyed.
Charles set the scene by describing the history, including the mistakes made, of diving. This led him on to describe the work of various researchers and the relevant laws of physics involved e.g. the key role of Boyle’s Law describing the relationship between pressure and volume. This led up to J. S. Haldane's 1908 report on 'The Prevention of Compressed Air Illness' from which the first dive tables were derived. In essence these give the diver key information on how long they can safely stay at particular depths. This in turn has now been computerised into a readily readable format that the diver has with them.
Divers now use Nitrox gas which is compressed air with 11% extra oxygen, the corresponding fall in nitrogen reducing the risk from nitrogen bubbles in the blood.
Charles then explained the factors that can get a diver into trouble. -- not monitoring depth and time properly, ascending too quickly, not observing the safety stop at 5m, and having residual nitrogen still in the blood from a previous dive. He then took us through a detailed look at the symptoms of, and any treatment, for a range of issues from decompression illness [think hyperbaric chamber], oxygen toxicity, hypercapnia, and ear barotrauma.
Safety involves being properly trained, diving within your limits, and always diving with a buddy.
At the end we were treated to a glorious set of images Charles has taken of life below the surface. Take your pick from dolphins, turtles, rays, fish, crabs and many others.
We zoomed in in every sense thanks to Charles. Jim Handley
Tuesday 10th March 2020 The Dynamic Life of Crystals
Speaker: Professor K.D.M.Harris, School of Chemistry, Cardiff University.
Attendance: 32
This was a rip-roaring and highly illustrated presentation through the hidden but beautiful world of crystals. Professor Harris defined crystals as crystalline solids which contain a particular spatial arrangement of atoms, arranged as repeated structures. Many of us will be familiar with the everyday crystals of salt, sugar and diamond but Professor Harris also showed us some remarkable gypsum crystals from a Mexican cave which over time had grown enormously to be several metres long.
The ability to analyse internal crystal structure has a relatively recent history and has been dependent on the invention of techniques like x-ray diffraction which was used by Rosalind Franklin to show the position of the atoms in DNA.
Many substances can have several crystalline forms like carbon which can exist as diamond and graphite. This is called polymorphism. Graphite is the more stable polymorph of carbon, but Professor Harris assured us that our diamond rings and accessories would exist for millions of years before they became graphite. Polymorphs can have very different properties which can be particularly important in the pharmaceutical industry where only one polymorph may be medically active.
Crystals can be formed in several ways including evaporation from a liquid, by cooling of a liquid and even by mechanical means in which grinding a mixture of two crystalline substances can result in the creation of a third.
We generally view crystals as stable and unchanging as the eminent chemist Leopold Ruzicka once observed, ‘a crystal is a chemical cemetery’. To disprove this Professor Harris took us through the life cycle of crystal.
The birth of a crystal is the starting point. It is known as ‘nucleation’ and is hard to study but it requires a certain energy threshold to be passed before a crystal can start to grow. Nowadays the use of high-power computers allows scientists to simulate the process as was shown by Professor Harris in a short video on the nucleation of methane hydrate.
In adolescence the crystal grows and polymorphic transformations can occur. But what determines the shape of a crystal? This is mostly down to the shape and arrangement of the individual molecules and the direction in which they prefer to grow. To illustrate this Professor Harris showed a beautiful video of the growth of a snowflake in which the growth and shape of the water crystal depended on the temperature and the humidity of the environment in which the crystal was growing . The hexagonal shape of the snowflake reflects the stable structure that water molecules assume as they freeze. It is possible to change the shape in which some crystals want to grow by artificial means, for example it is possible to make the normally longitudinal growth of urea crystals become lateral by chemically adding an end blocker to the crystal.
In maturity the shape does usually stay the same but Professor Harris finished by showing how individual crystals could be made to bend and unbend and distort in a number of ways in response to stimuli including UV irradiation which caused some crystals to bend and even mechanical means in which a tiny probe was used to bend a crystal in double. The most astonishing example for me was when a slight scratch with a metal instrument caused a crystal to change from one polymorph to another, right before our eyes. Guy Moody
11th February 2020 Household Recycling 2020
Carl Touhig works for Monmouthshire County Council and is Head of Neighbourhood Services. His responsibilities include roadside collections and Household Waste Recycling Centres. In consequence, Carl’s comments were of considerable interest to everyone attending.
There are many factors influencing the handling of waste and recycling. These include the willingness of the public generally to participate in separating domestic items, the practicality of having multiple different streams awaiting collection on the kerb, the type of collection vehicles available and the constantly changing value/cost for Monmouthshire County Council to dispose of it all. Carl described briefly the market, affected by worldwide policy changes and that can mean a “waste commodity” can change from something saleable to something for which there is a charge almost overnight. The only stream currently that generates an income is glass.
Inevitably, however, the major driver of policy for MCC is cost to the payers of council tax. This is not just the direct cost, but the not inconsiderable financial penalties imposed if the authority does not meet recycling targets. Currently it is struggling to meet targets.
Proposals being considered are:
Current initiatives include improving the quality of recycling, such as separating glass from plastics. This has been made possible by the introduction of crates for glass and vehicles equipped to keep the glass separate. Keeping the glass separate reduces the cost of the waste streams.
Another initiative which some residents living in Monmouth have already seen is the introduction of polypropylene sacks for plastics and paper. This is being done as a pilot project and MCC hopes to be able to use this pilot as the basis of a more universal roll-out in due course. Sending plastics unwrapped reduces the cost of the disposal, including saving around £200,000 buying plastic sacks, about 50 tonnes a year. There are a few problems with the new polypropylene bags which MCC hopes to resolve before more general use.
We were also told us about the issues surrounding the recycling centres at Usk and Mitchel Troy. Several U3A members expressed frustration about the times when the Troy Site is closed for the removal of skips notwithstanding the fact that it is closed anyway two days a week. Carl said that it was not possible with the current resources to ensure that all the skip exchange to be completed in the two days. One possible resolution for the Troy Site could be re-siting it on the MCC premises next to it. However, this is on the flood plain for the River Trothy which floods regularly, so it would not be without significant potential problems and cost. Although Mitchel Troy is not ideal it is a better site than Usk which is being considered for closure. Usk Town Council is contacting residents and businesses to reduce black bag waste and increase recycling.
Anyone interested to register a view about waste services can do so through “MyCouncilServices” on the MCC website. Michael Bone
January 14th 2020 A Layman’s Guide to Defence against Disease
In spite (or because! ) of inclement weather our first meeting of the New Year was well attended. Alan Francis, one of our group members guided us through the causes and treatment of diseases from man’s earliest misconceptions to our present understanding based on scientific evidence.
There are many causes of disease e.g. inherited, auto-immune, environmental, nutritional, behavioural and idiopathic, in addition to those caused by pathogens. Pathogens are the living organisms that cause disease and include viruses, bacteria, protozoa, fungi and multicellular organisms like tapeworms. Viruses are different from the other pathogens in that they are microscopic parasites and can only reproduce inside another organism.
The occurrence of disease can be classified into four categories depending on its severity: sporadic, endemic, epidemic and pandemic. A classic example of the latter is the influenza outbreak in 1918-20 which is believed to have originated in the USA and travelled to Europe with US troops. Contagion was exacerbated by the movement of large groups of people post WW1 and resulted in a very high mortality with an estimated 50 million deaths, mostly young to middle-aged. Influenza is a viral infection and because viruses were unknown at that time scientists were treating it as a bacterial infection, with no success.
Bacteria are only harmful when they are in the wrong place. The human body contains ten times more bacterial cells than body cells, with an estimated 2 to 3 kilogrammes per person. However, some can be deadly and the Bubonic Plague (Black Death) is a bacterial infection which spread through Europe in 1347 to 1350 resulting in an estimated 50% mortality rate. The Great Plague of London in 1665 -1666 which killed 70,000 people is another example of bubonic plague.
Alan described, with the help of informative diagrams and animations, the ways in which diseases are spread, the body’s natural defence systems and particularly the function of white blood cells in combating infection ---- our passive defence mechanism. He then went on to discuss adaptive immunity which is the specific response to a particular pathogen and can provide long lasting protection. Vaccination, first introduced by Jenner against smallpox in 1796, produces acquired immunity without infection. The vaccine can be a weakened form of the live pathogen (as in the MMR vaccine) or a dead pathogen. The vaccine stimulates the body to produce antibodies and provides long term protection against the disease. Vaccination has virtually eliminated the infectious diseases that were fatal in the past. It is regrettable that the latest figures show a small decline in the uptake of MMR vaccinations.
Progress in hygiene and the discovery of the powerful antibacterial drug penicillin have made their contribution to our defence against disease also. The fight against bacteria will go on as they develop resistance to antibiotics over time. Valerie Conniff
Science and Technology group meeting -- 10th December
For our end of year meeting we welcomed two of our own members talking about their careers.
Stephen McMenemy spoke about his ‘Career in Naval Shipbuilding 1975 – 2018’. Most of his career was based at Vickers Shipping and Engineering at Barrow in Furness. His apprenticeship and early training focused on becoming a ship’s draughtsman. Early projects involved working on HMS Invincible and then Trafalgar Class submarines where he specialised on structural design.
He then moved onto work on HMS Vanguard a nuclear powered submarine armed with US Trident missiles. From 2006 he was involved in development work on the HMS Dreadnought submarine.
From 2012 to 2016 he was based in Connecticut in a liaison role with the US builders working on the missile compartments common to both countries submarines. Finally returning to Barrow he was the UK Anglicization Manager ensuring that everyone worked from the same imperial measurement hymn sheet.
…………………………
Alan Manson introduced his talk by referring to how tea bags in the UK were first produced by Tetley in 1953 at Bletchley. Leaving school he responded to an advert to become an apprentice tea taster.
He told us about the characteristics of different teas and hence the importance of the blenders in achieving the right finished blend. He worked his way up becoming both the chief tea blender and manager of the Bletchley site. He too spent time in the US in Pennsylvania, having effectively been told he had to go there by the delightfully named UK head, Mr Tetley Ironsides Tetley–Jones.
In a world where 97% of our tea now comes in tea bags, Tetley [now part of the Tata Global Beverages brand] is the third largest supplier after Taylors and PG tips. And so to tea bags or mulled punch and nibbles. Jim Handley
Tuesday 12th November 2019 – Living with a Leaf: Bob Handley
The talk this month, with an enigmatic title, was given by Bob Handley who is a member of Monmouth U3A. Any expectations that this was going to be something botanical was soon overturned when Bob started to talk about his decision to purchase a Leaf, a Nissan Leaf.
The Leaf is a fully electric car which has been in production for some time. Bob purchased his car about eighteen months ago and has been monitoring his use of the vehicle. For him this was a second car in the household. Throughout the talk he stressed that the choices he made were based on his circumstances and everyone who considered changing away from a diesel or petrol engine model would need to make the decision based on their personal circumstances.
His choice of vehicle was a three year old Leaf with a 24KWh battery, for which he paid approximately £10,000. This battery size was one of the smaller batteries in production at the time and many cars now have much larger batteries.
He has elected to charge the battery from a 13Amp domestic socket rather than a dedicated 7KW charger which can be fitted at home, typically for less than £500. Using the domestic socket allows the car to be charged to full capacity in eight hours. This gave a range of approximately 80 miles. The car was purchased from a dealer in Glastonbury and charged to 80% of its maximum giving a range of 65 miles. This was the first introduction to “range anxiety” which is a reason many people do not switch to pure electric vehicles (EV). However, Bob prefers the expression “Range Awareness”. Plan your journeys and include stops for re-charging if necessary. Regular return trips to the Llandovery area (134 miles) include a planned stop at a Peterstone Hotel which provides a 13 Amp charge point free of charge, although you have to pay for lunch while you wait!
Payment arrangements for charging at public charge-points typically involve the use of a mobile phone but with time payment systems are making this easier. There are, confusingly, several different types of public chargers.
In hilly areas most electric cars benefit from regenerative braking where the battery can receive small amounts of charge from an energy recovery mechanism. Temperature affects range which is typically quoted at 23°C.
Bob uses his domestic solar panels to charge the Leaf as much as possible contributing anything from a third to two thirds of the power, depending on the time of year.
Nissan guarantee their batteries for 60,000 miles/5 years but if used carefully (maintaining charge in the range 20-80%) will last nearer ten years. They can then be refurbished for about £2500 or replaced for £5000.
Based on his usage, mainly shorter journeys, Bob estimated that the cost of ownership was less than half compared with, for example, a Toyota Auris. Again it was stressed that this was a calculation based on personal circumstances.
Overall, Bob was clearly very pleased with the Leaf and he and his wife enjoyed driving it. However, there are obvious concerns over longer journeys and in the bigger environmental debate concerns over electricity being generated by polluting power plants.
A few members of the audience also owned an EV and they were very positive about their choices. As Bob reiterated, it comes down to personal circumstances. Michael Bone
October 8th 2019 Life in the Freezer
This month we were privileged to have Dr Elizabeth Bagshaw, Senior Lecturer in the School of Earth and Ocean Sciences at Cardiff University, as our speaker. There could be no-one better qualified to address this topic as Dr Bagshaw has spent most of her professional life working in the field of Polar Science. She first visited the Antarctic during the first year of her doctorate research and has made three further trips since then as well as eleven visits to Greenland, where she now concentrates her research.
The Antarctic is the coldest, windiest, driest place on earth, Scott called it “an awful place” with temperatures reaching minus 90 degrees Celsius and winds of 200 miles per hour. No humans live permanently there, but scientists work on the science stations and it supports animals adapted to the cold such as penguins, seals, nematodes and tardigrades. Dr Bagshaw listed the survival strategies for creatures in these extreme conditions as furry, fatty, fluffy, fly or float and she illustrated this with examples.
It was not until 1999 that evidence of microbial life below the ice was discovered. As all living organisms need liquid water and an energy source to survive, it was difficult to imagine this being achieved under layers of ice where no sunlight could penetrate. The explanation lies in the existence of cryoconite holes. Cryoconite is a windblown dust, made up of small rock particles and microbes, which is deposited and builds up on glaciers and ice caps. This darkening of the surface absorbs solar radiation leading to the melting of the snow or ice below forming long cylindrical holes. The cryoconite sinks forming a deposit at the bottom which is known as a cryoconite hole. In winter an ice lid can form over the hole enclosing a small amount of water to sustain the microbes. These resulting ecosystems can survive for thousands of years without contact with the outside world.
Many different types of microbes, some heavily pigmented, have been identified and have found ways of adapting to their environment.
Dr Bagshaw’s research team have developed a “cryoegg” , a device the size of a grapefruit, which contains a circuit board and measures the temperature, pressure and conductivity of the surrounding meltwater. In Greenland this summer, a one and a half kilometer hole was drilled into the ice and the cryoegg lowered into the hole to collect data for analysis. These measurements will help us to understand how life can exist in these extreme conditions.
This research has wider applications: it can act as a model for life in Mars, it can predict what will happen when climate changes. On the biological side, microbes generate nutrients, what happens to them? What is in the melt water? These are but a few of the questions to be answered. It is remarkable that so much work has been done in twenty years , especially considering the experimental difficulties that have to be overcome. Valerie Conniff
10th September 2019 Solar Flight, Past, Present and Future Speaker: Phil Charlesworth
Phil Charlesworth is no stranger to the Science and Technology Group having previously talked about what he describes as his hobby, ‘amateur rocketry’. At this meeting Phil was talking about what used to be his day job at Airbus, until he retired and was poached by Liverpool Hope University.
Phil first talked about the generalities of solar flight which at the simplest means using solar energy to power a heavier than air machine which can stay in the air for a very long time, several days in fact. This is achieved by storing excess energy generated from solar cells to maintain flight during the hours of darkness. Although Phil admitted solar planes are in effect flying batteries, the planes do carry a small payload which is the reason for their development.
To do this you need a very light fuselage with a large surface area of wings which are covered in solar panels, a couple of electric motors, some batteries and an energy management system (EMS). The EMS controls all aspects of the flight by directing excess energy to the battery during the daytime and managing the flow of energy to the motors during the day and night, as well as providing energy to the payload which might be some sort of video-surveillance system. Using such a system it is possible to put a plane at heights of 17-18 km and keep it flying there for several days.
The reason for flying so high is that at that height the wind speeds are much lower than ground level so there is much less energy loss to resistance. However, the temperatures at that height place some very real pressures on the materials used, particularly for the batteries. The latitude the plane flies at is also important since at higher latitudes the ability to recharge the battery during winter months reduces the amount of flying time possible.
Phil made clear that the current state of solar powered flight is very much due to some modern technological advances including carbon fibre for weight reduction, ‘outrunner’ electric motors which being brushless greatly reduce friction losses, low temperature systems, computation fluid dynamics which has allowed improved low speed aerofoil design and 3D printing which has resulted in producing components more efficiently using less material. Other emerging technologies which have facilitated the developments in solar flight include very high specific energy batteries and very thin and flexible solar cells with efficiencies approaching 20% or more.
The history of solar flight can be traced to the 1950s but most advances have been in the last 10 or 15 years. A surprising number of companies have tried to develop solar planes, possibly because of military applications but these have now largely receded in the face of more humanitarian possibilities like disaster monitoring, search and rescue and improving internet coverage in isolated communities and tsunami detection.
Although Phil says that his former company Airbus is probably 10 years ahead of other companies his work with Liverpool Hope University is progressing well to the extent that he is currently building a solar electric aircraft in his garage! I, for one, am envious that he has enough space in his garage to even consider such a project. Guy Moody
Speaker: Professor K.D.M.Harris, School of Chemistry, Cardiff University.
Attendance: 32
This was a rip-roaring and highly illustrated presentation through the hidden but beautiful world of crystals. Professor Harris defined crystals as crystalline solids which contain a particular spatial arrangement of atoms, arranged as repeated structures. Many of us will be familiar with the everyday crystals of salt, sugar and diamond but Professor Harris also showed us some remarkable gypsum crystals from a Mexican cave which over time had grown enormously to be several metres long.
The ability to analyse internal crystal structure has a relatively recent history and has been dependent on the invention of techniques like x-ray diffraction which was used by Rosalind Franklin to show the position of the atoms in DNA.
Many substances can have several crystalline forms like carbon which can exist as diamond and graphite. This is called polymorphism. Graphite is the more stable polymorph of carbon, but Professor Harris assured us that our diamond rings and accessories would exist for millions of years before they became graphite. Polymorphs can have very different properties which can be particularly important in the pharmaceutical industry where only one polymorph may be medically active.
Crystals can be formed in several ways including evaporation from a liquid, by cooling of a liquid and even by mechanical means in which grinding a mixture of two crystalline substances can result in the creation of a third.
We generally view crystals as stable and unchanging as the eminent chemist Leopold Ruzicka once observed, ‘a crystal is a chemical cemetery’. To disprove this Professor Harris took us through the life cycle of crystal.
The birth of a crystal is the starting point. It is known as ‘nucleation’ and is hard to study but it requires a certain energy threshold to be passed before a crystal can start to grow. Nowadays the use of high-power computers allows scientists to simulate the process as was shown by Professor Harris in a short video on the nucleation of methane hydrate.
In adolescence the crystal grows and polymorphic transformations can occur. But what determines the shape of a crystal? This is mostly down to the shape and arrangement of the individual molecules and the direction in which they prefer to grow. To illustrate this Professor Harris showed a beautiful video of the growth of a snowflake in which the growth and shape of the water crystal depended on the temperature and the humidity of the environment in which the crystal was growing . The hexagonal shape of the snowflake reflects the stable structure that water molecules assume as they freeze. It is possible to change the shape in which some crystals want to grow by artificial means, for example it is possible to make the normally longitudinal growth of urea crystals become lateral by chemically adding an end blocker to the crystal.
In maturity the shape does usually stay the same but Professor Harris finished by showing how individual crystals could be made to bend and unbend and distort in a number of ways in response to stimuli including UV irradiation which caused some crystals to bend and even mechanical means in which a tiny probe was used to bend a crystal in double. The most astonishing example for me was when a slight scratch with a metal instrument caused a crystal to change from one polymorph to another, right before our eyes. Guy Moody
11th February 2020 Household Recycling 2020
Carl Touhig works for Monmouthshire County Council and is Head of Neighbourhood Services. His responsibilities include roadside collections and Household Waste Recycling Centres. In consequence, Carl’s comments were of considerable interest to everyone attending.
There are many factors influencing the handling of waste and recycling. These include the willingness of the public generally to participate in separating domestic items, the practicality of having multiple different streams awaiting collection on the kerb, the type of collection vehicles available and the constantly changing value/cost for Monmouthshire County Council to dispose of it all. Carl described briefly the market, affected by worldwide policy changes and that can mean a “waste commodity” can change from something saleable to something for which there is a charge almost overnight. The only stream currently that generates an income is glass.
Inevitably, however, the major driver of policy for MCC is cost to the payers of council tax. This is not just the direct cost, but the not inconsiderable financial penalties imposed if the authority does not meet recycling targets. Currently it is struggling to meet targets.
Proposals being considered are:
- promotional campaign
- compulsory recycling at the kerb side
- black bag sorting at Household Waste Recycling Centres (HWRC)
Current initiatives include improving the quality of recycling, such as separating glass from plastics. This has been made possible by the introduction of crates for glass and vehicles equipped to keep the glass separate. Keeping the glass separate reduces the cost of the waste streams.
Another initiative which some residents living in Monmouth have already seen is the introduction of polypropylene sacks for plastics and paper. This is being done as a pilot project and MCC hopes to be able to use this pilot as the basis of a more universal roll-out in due course. Sending plastics unwrapped reduces the cost of the disposal, including saving around £200,000 buying plastic sacks, about 50 tonnes a year. There are a few problems with the new polypropylene bags which MCC hopes to resolve before more general use.
We were also told us about the issues surrounding the recycling centres at Usk and Mitchel Troy. Several U3A members expressed frustration about the times when the Troy Site is closed for the removal of skips notwithstanding the fact that it is closed anyway two days a week. Carl said that it was not possible with the current resources to ensure that all the skip exchange to be completed in the two days. One possible resolution for the Troy Site could be re-siting it on the MCC premises next to it. However, this is on the flood plain for the River Trothy which floods regularly, so it would not be without significant potential problems and cost. Although Mitchel Troy is not ideal it is a better site than Usk which is being considered for closure. Usk Town Council is contacting residents and businesses to reduce black bag waste and increase recycling.
Anyone interested to register a view about waste services can do so through “MyCouncilServices” on the MCC website. Michael Bone
January 14th 2020 A Layman’s Guide to Defence against Disease
In spite (or because! ) of inclement weather our first meeting of the New Year was well attended. Alan Francis, one of our group members guided us through the causes and treatment of diseases from man’s earliest misconceptions to our present understanding based on scientific evidence.
There are many causes of disease e.g. inherited, auto-immune, environmental, nutritional, behavioural and idiopathic, in addition to those caused by pathogens. Pathogens are the living organisms that cause disease and include viruses, bacteria, protozoa, fungi and multicellular organisms like tapeworms. Viruses are different from the other pathogens in that they are microscopic parasites and can only reproduce inside another organism.
The occurrence of disease can be classified into four categories depending on its severity: sporadic, endemic, epidemic and pandemic. A classic example of the latter is the influenza outbreak in 1918-20 which is believed to have originated in the USA and travelled to Europe with US troops. Contagion was exacerbated by the movement of large groups of people post WW1 and resulted in a very high mortality with an estimated 50 million deaths, mostly young to middle-aged. Influenza is a viral infection and because viruses were unknown at that time scientists were treating it as a bacterial infection, with no success.
Bacteria are only harmful when they are in the wrong place. The human body contains ten times more bacterial cells than body cells, with an estimated 2 to 3 kilogrammes per person. However, some can be deadly and the Bubonic Plague (Black Death) is a bacterial infection which spread through Europe in 1347 to 1350 resulting in an estimated 50% mortality rate. The Great Plague of London in 1665 -1666 which killed 70,000 people is another example of bubonic plague.
Alan described, with the help of informative diagrams and animations, the ways in which diseases are spread, the body’s natural defence systems and particularly the function of white blood cells in combating infection ---- our passive defence mechanism. He then went on to discuss adaptive immunity which is the specific response to a particular pathogen and can provide long lasting protection. Vaccination, first introduced by Jenner against smallpox in 1796, produces acquired immunity without infection. The vaccine can be a weakened form of the live pathogen (as in the MMR vaccine) or a dead pathogen. The vaccine stimulates the body to produce antibodies and provides long term protection against the disease. Vaccination has virtually eliminated the infectious diseases that were fatal in the past. It is regrettable that the latest figures show a small decline in the uptake of MMR vaccinations.
Progress in hygiene and the discovery of the powerful antibacterial drug penicillin have made their contribution to our defence against disease also. The fight against bacteria will go on as they develop resistance to antibiotics over time. Valerie Conniff
Science and Technology group meeting -- 10th December
For our end of year meeting we welcomed two of our own members talking about their careers.
Stephen McMenemy spoke about his ‘Career in Naval Shipbuilding 1975 – 2018’. Most of his career was based at Vickers Shipping and Engineering at Barrow in Furness. His apprenticeship and early training focused on becoming a ship’s draughtsman. Early projects involved working on HMS Invincible and then Trafalgar Class submarines where he specialised on structural design.
He then moved onto work on HMS Vanguard a nuclear powered submarine armed with US Trident missiles. From 2006 he was involved in development work on the HMS Dreadnought submarine.
From 2012 to 2016 he was based in Connecticut in a liaison role with the US builders working on the missile compartments common to both countries submarines. Finally returning to Barrow he was the UK Anglicization Manager ensuring that everyone worked from the same imperial measurement hymn sheet.
…………………………
Alan Manson introduced his talk by referring to how tea bags in the UK were first produced by Tetley in 1953 at Bletchley. Leaving school he responded to an advert to become an apprentice tea taster.
He told us about the characteristics of different teas and hence the importance of the blenders in achieving the right finished blend. He worked his way up becoming both the chief tea blender and manager of the Bletchley site. He too spent time in the US in Pennsylvania, having effectively been told he had to go there by the delightfully named UK head, Mr Tetley Ironsides Tetley–Jones.
In a world where 97% of our tea now comes in tea bags, Tetley [now part of the Tata Global Beverages brand] is the third largest supplier after Taylors and PG tips. And so to tea bags or mulled punch and nibbles. Jim Handley
Tuesday 12th November 2019 – Living with a Leaf: Bob Handley
The talk this month, with an enigmatic title, was given by Bob Handley who is a member of Monmouth U3A. Any expectations that this was going to be something botanical was soon overturned when Bob started to talk about his decision to purchase a Leaf, a Nissan Leaf.
The Leaf is a fully electric car which has been in production for some time. Bob purchased his car about eighteen months ago and has been monitoring his use of the vehicle. For him this was a second car in the household. Throughout the talk he stressed that the choices he made were based on his circumstances and everyone who considered changing away from a diesel or petrol engine model would need to make the decision based on their personal circumstances.
His choice of vehicle was a three year old Leaf with a 24KWh battery, for which he paid approximately £10,000. This battery size was one of the smaller batteries in production at the time and many cars now have much larger batteries.
He has elected to charge the battery from a 13Amp domestic socket rather than a dedicated 7KW charger which can be fitted at home, typically for less than £500. Using the domestic socket allows the car to be charged to full capacity in eight hours. This gave a range of approximately 80 miles. The car was purchased from a dealer in Glastonbury and charged to 80% of its maximum giving a range of 65 miles. This was the first introduction to “range anxiety” which is a reason many people do not switch to pure electric vehicles (EV). However, Bob prefers the expression “Range Awareness”. Plan your journeys and include stops for re-charging if necessary. Regular return trips to the Llandovery area (134 miles) include a planned stop at a Peterstone Hotel which provides a 13 Amp charge point free of charge, although you have to pay for lunch while you wait!
Payment arrangements for charging at public charge-points typically involve the use of a mobile phone but with time payment systems are making this easier. There are, confusingly, several different types of public chargers.
In hilly areas most electric cars benefit from regenerative braking where the battery can receive small amounts of charge from an energy recovery mechanism. Temperature affects range which is typically quoted at 23°C.
Bob uses his domestic solar panels to charge the Leaf as much as possible contributing anything from a third to two thirds of the power, depending on the time of year.
Nissan guarantee their batteries for 60,000 miles/5 years but if used carefully (maintaining charge in the range 20-80%) will last nearer ten years. They can then be refurbished for about £2500 or replaced for £5000.
Based on his usage, mainly shorter journeys, Bob estimated that the cost of ownership was less than half compared with, for example, a Toyota Auris. Again it was stressed that this was a calculation based on personal circumstances.
Overall, Bob was clearly very pleased with the Leaf and he and his wife enjoyed driving it. However, there are obvious concerns over longer journeys and in the bigger environmental debate concerns over electricity being generated by polluting power plants.
A few members of the audience also owned an EV and they were very positive about their choices. As Bob reiterated, it comes down to personal circumstances. Michael Bone
October 8th 2019 Life in the Freezer
This month we were privileged to have Dr Elizabeth Bagshaw, Senior Lecturer in the School of Earth and Ocean Sciences at Cardiff University, as our speaker. There could be no-one better qualified to address this topic as Dr Bagshaw has spent most of her professional life working in the field of Polar Science. She first visited the Antarctic during the first year of her doctorate research and has made three further trips since then as well as eleven visits to Greenland, where she now concentrates her research.
The Antarctic is the coldest, windiest, driest place on earth, Scott called it “an awful place” with temperatures reaching minus 90 degrees Celsius and winds of 200 miles per hour. No humans live permanently there, but scientists work on the science stations and it supports animals adapted to the cold such as penguins, seals, nematodes and tardigrades. Dr Bagshaw listed the survival strategies for creatures in these extreme conditions as furry, fatty, fluffy, fly or float and she illustrated this with examples.
It was not until 1999 that evidence of microbial life below the ice was discovered. As all living organisms need liquid water and an energy source to survive, it was difficult to imagine this being achieved under layers of ice where no sunlight could penetrate. The explanation lies in the existence of cryoconite holes. Cryoconite is a windblown dust, made up of small rock particles and microbes, which is deposited and builds up on glaciers and ice caps. This darkening of the surface absorbs solar radiation leading to the melting of the snow or ice below forming long cylindrical holes. The cryoconite sinks forming a deposit at the bottom which is known as a cryoconite hole. In winter an ice lid can form over the hole enclosing a small amount of water to sustain the microbes. These resulting ecosystems can survive for thousands of years without contact with the outside world.
Many different types of microbes, some heavily pigmented, have been identified and have found ways of adapting to their environment.
Dr Bagshaw’s research team have developed a “cryoegg” , a device the size of a grapefruit, which contains a circuit board and measures the temperature, pressure and conductivity of the surrounding meltwater. In Greenland this summer, a one and a half kilometer hole was drilled into the ice and the cryoegg lowered into the hole to collect data for analysis. These measurements will help us to understand how life can exist in these extreme conditions.
This research has wider applications: it can act as a model for life in Mars, it can predict what will happen when climate changes. On the biological side, microbes generate nutrients, what happens to them? What is in the melt water? These are but a few of the questions to be answered. It is remarkable that so much work has been done in twenty years , especially considering the experimental difficulties that have to be overcome. Valerie Conniff
10th September 2019 Solar Flight, Past, Present and Future Speaker: Phil Charlesworth
Phil Charlesworth is no stranger to the Science and Technology Group having previously talked about what he describes as his hobby, ‘amateur rocketry’. At this meeting Phil was talking about what used to be his day job at Airbus, until he retired and was poached by Liverpool Hope University.
Phil first talked about the generalities of solar flight which at the simplest means using solar energy to power a heavier than air machine which can stay in the air for a very long time, several days in fact. This is achieved by storing excess energy generated from solar cells to maintain flight during the hours of darkness. Although Phil admitted solar planes are in effect flying batteries, the planes do carry a small payload which is the reason for their development.
To do this you need a very light fuselage with a large surface area of wings which are covered in solar panels, a couple of electric motors, some batteries and an energy management system (EMS). The EMS controls all aspects of the flight by directing excess energy to the battery during the daytime and managing the flow of energy to the motors during the day and night, as well as providing energy to the payload which might be some sort of video-surveillance system. Using such a system it is possible to put a plane at heights of 17-18 km and keep it flying there for several days.
The reason for flying so high is that at that height the wind speeds are much lower than ground level so there is much less energy loss to resistance. However, the temperatures at that height place some very real pressures on the materials used, particularly for the batteries. The latitude the plane flies at is also important since at higher latitudes the ability to recharge the battery during winter months reduces the amount of flying time possible.
Phil made clear that the current state of solar powered flight is very much due to some modern technological advances including carbon fibre for weight reduction, ‘outrunner’ electric motors which being brushless greatly reduce friction losses, low temperature systems, computation fluid dynamics which has allowed improved low speed aerofoil design and 3D printing which has resulted in producing components more efficiently using less material. Other emerging technologies which have facilitated the developments in solar flight include very high specific energy batteries and very thin and flexible solar cells with efficiencies approaching 20% or more.
The history of solar flight can be traced to the 1950s but most advances have been in the last 10 or 15 years. A surprising number of companies have tried to develop solar planes, possibly because of military applications but these have now largely receded in the face of more humanitarian possibilities like disaster monitoring, search and rescue and improving internet coverage in isolated communities and tsunami detection.
Although Phil says that his former company Airbus is probably 10 years ahead of other companies his work with Liverpool Hope University is progressing well to the extent that he is currently building a solar electric aircraft in his garage! I, for one, am envious that he has enough space in his garage to even consider such a project. Guy Moody
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