Science & Technology

September 4th 2007

As first seen from space by the Apollo astronauts, the earth was described as “a beautiful, fragile bauble set against the black background of space.” These were the opening lines quoted by Ralph as introduction to our September meeting.

The presentation gave a wide coverage of aspects of the environment of our world and factors which could affect its well-being. The defence from the sun’s deadly rays provided by our atmosphere, especially the ozone layer and the great work by scientists such as those given the 1996 Nobel Prize for Chemistry, was described. The proof of such work by the discovery of a huge hole in the Antarctic ozone layer by CFC chemicals has led to severe restrictions in their use. Likewise the pioneering work of Rachel Carson (Silent Spring), famous for her warnings on the danger of pesticides such as DDT and the centenary of her birth this year, were illustrated.

A range of concerns about the dangers of environmental destruction, pollution and global warming was noted. These included mining and chemical processes which often cause problems such as acid rain, destruction of the terrain, industrial accidents and warfare. Many publications (several from the press) were shown to illustrate the concern about the “greenhouse effect” on the polar ice, water supplies and possibly the Gulf Stream.

The increase in the acidity of the oceans could have a devastating effect on marine life such as coral and food chains. The predictions postulated in several international papers have led to forecasts of the increasing impact on the climate over the next fifty to one hundred years with serious effects on human habitation.

Ralph pointed out that not all is doom and gloom and that we can all help by supporting sound environmental practices and those who have invested in enterprises such as the Chineham ERF (previously reported).

October 2nd 2007

The science, technology and agricultural aspects of the beautiful crystals we use as granulated sugar and the sheer scale of production in many countries was a revelation at our October meeting. Richard Risby, one of our group and a chemical engineer with much experience in sugar production, illustrated the historical development of sugar cane from Polynesia and Babylon over 2-3000 years.

Although recorded as a £3000/t import to the UK in 1319, its growth in Europe was more rapid in the 18th and 19th centuries. In 1750 120 British cane refineries produced 30,000 t/a, whilst now 160 m/t per annum are produced and sugar is traded as a commodity. Brazil exports over 15m/t to Europe.

Richard developed the subject from explaining cane growing, the effects of the climate and harvesting, to the production of cut sugar cane. Mechanical harvesting on a huge scale up to 6-12,000 t/day delivers cane to large complex but sophisticated and environmentally sound factories, where virtually no waste is produced. The processing of sugar beet is closely related.

The cane, containing about 12% sucrose, is crushed and raw juice extracted. The bagasse waste is used as fuel and in agriculture. The clarification of liquors, evaporation and crystallisation processes were well illustrated, with all the necessary refining chemistry and storage. The range of sugar products, e.g. Golden Syrup, caster sugar, brown sugars, etc., as well as nutritional details and the relative sweetness of sugar substitutes were shown.

Brown sugars are pure white cane sugar with additives such as molasses and dyes (which could come as a surprise!). Small “Lucky Bags” of different sugars were given to members for being well behaved.

We thank Richard and Brenda, his wife, for an unusual topic, well presented, with a table display of informative items.

November 6th 2007

At our November meeting Stan Skinner related the spectacular developments over 50 years leading to current computers. Early types of computers were established to provide mathmatical calculations for navigation and as early as 1642 Blais Pascal devised a mechanical machine.

The first real mechanical computer was developed by Charles Babbage (1791-1871) with his Difference and Analytical Engines, the latter being activated with punch card inputs. Fast computers based on thermionic valves allowed rapid progress during and after World War II, with the code-breaking Colossus, to be followed shortly by ENIAC and EDSAC machines. Large installations based on many thermionic valves required huge power, cooling and maintenance. Advances in many areas contributed to the rapid recent improvements in computer technology. These included the use of binary codes, storage, processors displays, printers, etc.

1948 provided the major milestone with the transistor and the development of semi-conductor substrates and miniaturised integrated circuitry so that microprocessors manipulated data rapidly. Machine instructions (language) such as FORTRAN and COBOL widened the applications of computers. Large mainframe computers for business use, e.g. IBM, allowed timesharing and real time applications.

Mini-computers, home computers, personal computers and the growth of the internet followed, allowing huge performance from relatively small and low cost systems. Stan provided an excellent report and demonstration but as ever he remarked that “GIGO – garbage in, garbage out”. Don’t always blame the machine!

January 8th 2008

The following notes were provided at Januarys meeting as a summary of Ralphs comprehensive presentation.

	Printing provides the means of replicating a designed graphic on a surface using many ancient and modern techniques. Some device or machine applies an image former (ink) to a substrate. This can be of many different types, e.g. paper, plastic, metal, etc. Modern contactless methods have developed essentially based on computer technology and modern printing materials.
	For many centuries raised characters were produced by carving wood blocks. Modern flexography uses plastic plates treated to give relief features. Intaglio (recessed) ink carrying images, etched plates, etc., were common around the 1500s, whilst lithography (flat) printing developed greatly to become the most common current printing. Gravure, screen followed.
	In AD 868 the first book (Diamond Sutra) used relief carved wood blocks to transfer ink to paper. Woodcuts developed quickly to provide designs integrated with text. Hans Leonard Beck, 1515, produced excellent engraved wood block carvings, whilst superb later wood engravings were produced by Thomas Bewick in the early 1800s using the end grain of hard woods.
	In letterpress printing Johannes Gutenberg used a wine screw press with oil based ink on cast metal type and produced a printed bible in 1454. In 1476 William Caxton set up a press in Westminster and printed the first English book. Caxton printed around 100 popular books and poems, such as Aesops Fables. Moveable metal type was a fundamental improvement.
	Intaglio, gravure, etching and engraving developed from c.1430 using copper plates. Maps, such as those by John Speed (multi- coloured registered plates made in Holland), were engraved on copper. Rembrandt, 1669, used methods where etching and engraving produced variable depth tonal art work. Later steel, iron plated steel and aluminium sheets were used.
	Typewriters changed office and home printing from the 1870s where many variations quickly developed. Alongside the machines paper, tapes and carbonless copy paper developed until in the 1920s electrical and variable typeface machines could type and print at high quality and speeds. This equipment and features formed the basis of our modern systems.
	Gravure (photogravure) is an intaglio recessed cell method. Rotary machines developed from the 1890s using photographic half-tone screen principles with blade cleaning of inked cylinders. Cylinders etched by chemicals, mechanically and laser, allow for fast multicolour registered processing on many substrates for high quality imaging, e.g. magazines, art work.
	Lithography originated c.1798 and uses a treated surface which accepts ink only in areas to be printed. Over 150 years developments were rapid in machine powered rotary presses operating at high speeds. Developments in photography, plate surfaces, inks, etc., make this today the preferred high speed quality, long run process.
	The Woods Press (N.Y. 1934), using double sided offset lithographic printing, ran in Fleet Street until 1975 and could produce 100,000 Daily Mail newspapers/hour. It weighed 140 tons. Electronic computer controlled rotary offset presses are claimed to produce double sided outputs of 180,000 papers/hour. Now we enjoy multicoloured print which lithography has brought.
	Modern laser/toner copiers arose from Chester Charlton' s 1937 patent for the electrophotographic process now called xerography. A drum electrostatically charged can be treated to give image areas attracting powdered toner. This is transferred and fused to paper. High quality print at c.1 00 A4 pages/minute is possible but is only 5% of lithographic print speeds.
	Inkjet computer controlled printers have, over 40 years, become home/office essentials. Plateless digital images from a computer store are formed from charged ink droplets directed to the printed surface. Ink pulses from piezo-electric crystals or bubble vapour pressure from heated ink source back plates produce c.200 microns dots at c.2,000 dpi.
	Dye sublimation (dye thermal transfer) imaging relies on carrier layers containing coloured dyes which become vapour on heating and then condense on the printed surface. Computer driven electrically heated heads rapidly heat the dye carrier tapes selectively to produce high quality imaging for fabrics and art work in wide widths.

February 5th 2008

Since oil was struck at Oil Creek, Pennsylvania, USA, in 1859 the growth and importance of the oil industry has been enormous and will continue to be so. However, as Norman Perkins explained in his February talk, oil has been known in various forms since Sumerian (3500 BC) and Babylonian times (2000 BC).

The formation and composition of crude oils from various sources over hundreds of millions of years from organic materials was explained. The locating of oil and gas sources in various capped porous rock formations and oil well drilling descriptions from ancient manual digging to modern 5000m drillings (often offshore on oil rigs) were explained and illustrated.

The basic structures of fractions obtained by distillation in huge refineries and their uses, ranging from petrol, diesel to bitumen, illustrated the expertise employed in all science and engineering disciplines. Our dependency on oil products and its bulk transportation still grows worldwide and Norman indicated some future possible means of producing fuels and energy, ranging from bio-crop fuels to Arctic gas hydrates.

The early developments of BP essentially started with William Knox D’Arcy who made money from mining gold in Australia and then invested in oil exploration in Persia. He exploited a concession in 1901 which allowed sixty years development of petroleum products. Once commercial quantities of oil were confirmed the Anglo-Persian Oil Company was formed, eventually leading to the company we now know as BP.

The effects of political, wartime and other factors highlighted the perseverance and important contribution of BP to our national benefit.

A lasting recollection was that great dangers have always existed requiring courage and commitment in the oil and gas industries. Dramatic blow-outs and well-head fires, as well as environmental effects especially for offshore recovery, emphasise the need for continuous commitment and outstanding professionalism.

March 4th 2008

Our March meeting was a pre-opening update of an earlier talk (February 2006) in which Keith Lang (Design Manager, involved in many engineering fit-out areas) gave an illustrated talk.

The enormous scale of the terminal which will be opened on 27th March was reviewed.

Standing 40m high and nearly 400m long, the building utilised 30,000 sq.m. of glass and was designed for minimal environmental impact, best access and public ease.

Keith described the terminal access and huge parking areas, whilst large beacons internally will assist passengers to find the right check-in areas. For ease of baggage check-in and handling a major new system of e-ticketing has been installed. This can greatly assist rapid transit through prior registration through the internet BAA website.

Security will also be slicker with shoe, body and case scanning which represents a large investment. Different levels of scanning for cases and “sniffing” for drugs and explosives will be employed depending upon the level of security required.

Very large shopping and duty-free facilities will be present with many leading fashion and luxury goods houses as well as leading restaurants. The sophisticated system for aircraft boarding, docking on arrival and disembarkment was of major interest. The baggage collection arrangements and areas should prove a welcomed improvement.

April 1st 2008

In his April talk John Russell showed, in a systematic and clearly illustrated talk, how Britain’s pre-eminence through the Industrial Revolution grew with the huge increase in power generation.

Before c.1700 power was locally produced from water and windmills, whereas industrial growth was related to vast increases in coal production. The latter depended on pumping water from mines where Thomas Savery’s atmospheric vertical pump (“The Miner’s Friend”) was a great help but limited by available steam pressures.

Thomas Newcomen, using atmosphere pressure/vacuum principles, installed a beam engine pump at Dudley Castle in 1712. By 1733 c.100 Newcomen engines were in widespread use and working examples can still be seen today. John Smeaton later made improvements in the exorbitant consumption of water and fuel but James Watt (1736-1819) provided dramatic changes using separate condensers, valves and cylinders.

Matthew Boulton, using Watt’s scheme, added major improvements in fuel efficiency with true boring of cast iron cylinders. From 1773 together Boulton and Watt used “sun and planet” gearing to produce rotary motion. Richard Trevithick (1771-1833) used high pressure steam in compound engines for first true locomotion. George and Robert Stephenson made well known rail innovations as well as farming and industrial traction. Enormous engines up to 1400 horse power became available.

Sir Charles Parsons provided the next great step with impulse and reaction turbines such as seen in his yacht Turbinia, 1897. Rapid developments led by 1912 to a 25,000 kw generator in Chicago and turbine driven ships, e.g. HMS Dreadnought.

Today industrial, domestic, electrical and marine power depends critically on the advent of later stages of these power generation technologies. It is interesting to note that the ancient Greek Hero had a steam jet driven rotary machine which is where we have arrived at now.

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