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61 elaborate
1. [i'læbəreit] verb1) (to work out or describe (a plan etc) in detail: He elaborated his theory.) detalhar2) ((especially with on) to discuss details: She elaborated on the next day's menu.) detalhar2. [-rət] adjective1) (very detailed or complicated: an elaborate design.) complexo2) (carefully planned: elaborate plans for escape.) meticuloso•- elaboration -
62 bond yield
Finthe annual return on a bond (the rate of interest) expressed as a percentage of the current market price of the bond. Bonds can tie up investors’ money for periods of up to 30 years, so knowing their yield is a critical investment consideration.EXAMPLEBond yield is calculated by multiplying the face value of the bond by its stated annual rate of interest, expressed as a decimal. For example, buying a new ten-year $1,000 bond that pays 6% interest will produce an annual yield amount of $60:1,000 × 0.060 = 60The $60 will be paid as $30 every six months. At the end of ten years, the purchaser will have earned $600, and will also be repaid the original $1,000. Because the bond was purchased when it was first issued, the 6% is also called the “yield to maturity.”This basic formula is complicated by other factors. First is the “time-value of money” theory: money paid in the future is worth less than money paid today. A more detailed computation of total bond yield requires the calculation of the present value of the interest earned each year. Second, changing interest rates have an impact on bond trading and, ultimately, on yield. Changes in interest rates cannot affect the interest paid by bonds already issued, but they do affect the prices of new bonds. -
63 Cierva, Juan de la
SUBJECT AREA: Aerospace[br]b. 21 September 1895 Murcia, Spaind. 9 December 1936 Croydon, England[br]Spanish engineer who played a major part in developing the autogiro in the 1920s and 1930s.[br]At the age of 17, Cierva and some of his friends built a successful two-seater biplane, the BCD-1 (C for Cierva). By 1919 he had designed a large three-engined biplane bomber, the C 3, which unfortunately crashed when its wing stalled (list its lift) during a slow-speed turn. Cierva turned all his energies to designing a flying machine which could not stall: his answer was the autogiro. Although an autogiro looks like a helicopter, its rotor blades are not driven by an engine, but free-wheel like a windmill. Forward speed is provided by a conventional engine and propeller, and even if this engine fails, the autogiro's rotors continue to free-wheel and it descends safely. Cierva patented his autogiro design in 1920, but it took him three years to put theory into practice. By 1925, after further improvements, he had produced a practical rotary-winged flying machine.He moved to England and in 1926 established the Cierva Autogiro Company Ltd. The Air Ministry showed great interest and a year later the British company Avro was commissioned to manufacture the C 6A Autogiro under licence. Probably the most significant of Cierva's autogiros was the C 30A, or Avro Rota, which served in the Royal Air Force from 1935 until 1945. Several other manufacturers in France, Germany, Japan and the USA built Cierva autogiros under licence, but only in small numbers and they never really rivalled fixed-wing aircraft. The death of Cierva in an airliner crash in 1936, together with the emergence of successful helicopters, all but extinguished interest in the autogiro.[br]Principal Honours and DistinctionsDaniel Guggenheim Medal. Royal Aeronautical Society Silver Medal, Gold Medal (posthumously) 1937.Bibliography1931, Wings of To-morrow: The Story of the Autogiro, New York (an early account of his work).He read a paper on his latest achievements at the Royal Aeronautical Society on 15 March 1935.Further ReadingP.W.Brooks, 1988, Cierva Autogiros: The Development of Rotary Wing Flight, Washington, DC (contains a full account of Cierva's work).Jose Warleta. 1977, Autogiro: Juan de la Cierva y su obra, Madrid (a detailed account of his work in Spain).Oliver Stewart, 1966, Aviation: The Creative Ideas, London (contains a chapter on Cierva).JDS -
64 Dunne, John William
SUBJECT AREA: Aerospace[br]b. 2 December 1875 Co. Kildare, Irelandd. 24 August 1949 Oxfordshire, England[br]Irish inventor who pioneered tailless aircraft designed to be inherently stable.[br]After serving in the British Army during the Boer War. Dunne returned home convinced that aeroplanes would be more suitable than balloons for reconnaissance work. He built models to test his ideas for a tailless design based on the winged seed of a Javanese climbing plant. In 1906 Dunne joined the staff of the Balloon Factory at Farnborough, where the Superintendent, Colonel J.E.Capper, was also interested in manned kites and aeroplanes. Since 1904 the colourful American "Colonel" S.F. Cody had been experimenting at Farnborough with manned kites, and in 1908 his "British Army Dirigible No. 1" made the first powered flight in Britain. Dunne's first swept-wing tailless glider was ready to fly in the spring of 1907, but it was deemed to be a military secret and flying it at Farnborough would be too public. Dunne, Colonel Capper and a team of army engineers took the glider to a remote site at Blair Atholl in Scotland for its test flights. It was not a great success, although it attracted snoopers, with the result that it was camouflaged. Powered versions made short hops in 1908, but then the War Office withdrew its support. Dunne and his associates set up a syndicate to continue the development of a new tailless aeroplane, the D 5; this was built by Short Brothers (see Short, Hugh Oswald) and flew successfully in 1910. It had combined elevators and ailerons on the wing tips (or elevons as they are now called when fitted to modern delta-winged aircraft). In 1913 an improved version of the D 5 was demonstrated in France, where the pilot left his cockpit and walked along the wing in flight. Dunne had proved his point and designed a stable aircraft, but his health was suffering and he retired. During the First World War, however, it was soon learned that military aircraft needed to be manoeuvrable rather than stable.[br]Bibliography1913, "The theory of the Dunne aeroplane", Journal of the Royal Aeronautical Society (April).After he left aviation, Dunne became well known for his writings on the nature of the universe and the interpretation of dreams. His best known-work was An ExperimentWith Time (1927; and reprints).Further ReadingP.B.Walker, 1971, Early Aviation at Farnborough, Vol. I, London; 1974, Vol. II (provides a detailed account of Dunne's early work; Vol. II is the more relevant).P.Lewis, 1962, British Air craft 1809–1914, London (for details of Dunne's aircraft).JDS -
65 Griffith, Alan Arnold
[br]b. 13 June 1893 London, Englandd. 13 October 1963 Farnborough, England[br]English research engineer responsible for many original ideas, including jet-lift aircraft.[br]Griffith was very much a "boffin", for he was a quiet, thoughtful man who shunned public appearances, yet he produced many revolutionary ideas. During the First World War he worked at the Royal Aircraft Factory, Farnborough, where he carried out research into structural analysis. Because of his use of soap films in solving torsion problems, he was nicknamed "Soap-bubble".During the 1920s Griffith carried out research into gas-turbine design at the Royal Aircraft Establishment (RAE; as the Royal Aircraft Factory had become). In 1929 he made proposals for a gas turbine driving a propeller (a turboprop), but the idea was shelved. In the 1930s he was head of the Engine Department of the RAE and developed multi-stage axial compressors, which were later used in jet engines. This work attracted the attention of E.W. (later Lord) Hives of Rolls-Royce who persuaded Griffith to join Rolls-Royce in 1939. His first major project was a "contra-flow" jet engine, which was a good idea but a practical failure. However, Griffith's axial-flow compressor experience played an important part in the success of Rolls-Royce jet engines from the Avon onwards. He also proposed the bypass principle used for the Conway.Griffith experimented with suction to control the boundary layer on wings, but his main interest in the 1950s centred on vertical-take-off and -landing aircraft. He developed the remarkable "flying bedstead", which consisted of a framework (the bedstead) in which two jet engines were mounted with their jets pointing downwards, thus lifting the machine vertically. It first flew in 1954 and provided much valuable data. The Short SC1 aircraft followed, with four small jets providing lift for vertical take-off and one conventional jet to provide forward propulsion. This flew successfully in the late 1950s and early 1960s. Griffith proposed an airliner with lifting engines, but the weight of the lifting engines when not in use would have been a serious handicap. He retired in 1960.[br]Principal Honours and DistinctionsCBE 1948. FRS 1941. Royal Aeronautical Society Silver Medal 1955; Blériot Medal 1962.BibliographyGriffith produced many technical papers in his early days; for example: 1926, Aerodynamic Theory of Turbine Design, Farnborough.Further ReadingD.Eyre, 1966, "Dr A.A.Griffith, CBE, FRS", Journal of the Royal Aeronautical Society (June) (a detailed obituary).F.W.Armstrong, 1976, "The aero engine and its progress: fifty years after Griffith", Aeronautical Journal (December).O.Stewart, 1966, Aviation: The Creative Ideas, London (provides brief descriptions of Griffith's many projects).JDS -
66 Hjorth, Soren
SUBJECT AREA: Electricity[br]b. 13 October 1801 Vesterbygaard, Denmarkd. 28 August 1870 Copenhagen, Denmark[br]Danish engineer and inventor who first proposed the principle of the self-excited dynamo.[br]After passing a legal examination, Hjorth found employment in the state treasury in Copenhagen and in 1830 advanced to be Clerk of the Exchequer and Secretary. In 1834 he visited England to study the use of steam road and rail vehicles. Hjorth was involved in the formation of the first railway company in Denmark and became Technical Director of Denmark's first railway, a line between Copenhagen and Roskilde that opened in 1847. In 1848 he petitioned the Government for funds to visit England and have built there an electric motor of his own design with oscillating motion. This petition, supported by Hans Christian Oersted (1777–1851), was granted. A British patent was obtained for the machine, an example being exhibited at the 1851 Great Exhibition in London. Turning his attention to the generation of electricity, he conceived as early as May 1851 the dynamo electric principle with self-excitation that was incorporated in his patent in 1855. Unfortunately, Hjorth held the firm but mistaken belief that if he could use his dynamo to drive a motor he would obtain more power than was consumed in driving the dynamo. The theory of conservation of energy was being only slowly accepted at that time, and Hjorth, with little scientific training, was to be disappointed at the failure of his schemes. He worked with great perseverance and industry to the end of his life on the design of his electrical machines.[br]Bibliography11 April 1855, British patent no. 806 (Hjorth's self-excited dynamo).11 April 1855, British patent nos. 807 and 808 (reciprocating and rotary electric motors).Further ReadingS.Smith, 1912, Soren Hjorth, Copenhagen (the most detailed biography).1907, "Soren Hjorth, discoverer of the dynamo-electric principle", Electrical Engineering 1: 957–8 (a short biography).Catalogue of the 1851 Exhibition, 1851, London, pp. 1, 359–60 (for a description of Hjorth's electromagnetic engine with oscillating motion.GW -
67 Lucas, Anthony Francis
SUBJECT AREA: Mining and extraction technology[br]b. 9 September 1855 Spalato, Dalmatia, Austria-Hungary (now Split, Croatia)d. 2 September 1921 Washington, DC, USA[br]Austrian (naturalized American) mining engineer who successfully applied rotary drilling to oil extraction.[br]A former Second Lieutenant of the Austrian navy (hence his later nickname "Captain") and graduate of the Polytechnic Institute of Graz, Lucas decided to stay in Michigan when he visited his relatives in 1879. He changed his original name, Lucie, into the form his uncle had adopted and became a naturalized American citizen at the age of 30. He worked in the lumber industry for some years and then became a consulting mechanical and mining engineer in Washington, DC. He began working for a salt-mining company in Louisiana in 1893 and became interested in the geology of the Mexican Gulf region, with a view to prospecting for petroleum. In the course of this work he came to the conclusion that the hills in this elevated area, being geological structures distinct from the surrounding deposits, were natural reservoirs of petroleum. To prove his unusual theory he subsequently chose Spindle Top, near Beaumont, Texas, where in 1899 he began to bore a first oil-well. A second drill-hole, started in October 1900, was put through clay and quicksand. After many difficulties, a layer of rock containing marine shells was reached. When the "gusher" came out on 10 January 1901, it not only opened up a new era in the oil and gas business, but it also led to the future exploration of the terrestrial crust.Lucas's boring was a breakthrough for the rotary drilling system, which was still in its early days although its principles had been established by the English engineer Robert Beart in his patent of 1884. It proved to have advantages over the pile-driving of pipes. A pipe with a simple cutter at the lower end was driven with a constantly revolving motion, grinding down on the bottom of the well, thus gouging and chipping its way downward. To deal with the quicksand he adopted the use of large and heavy casings successively telescoped one into the other. According to Fauvelle's method, water was forced through the pipe by means of a pump, so the well was kept full of circulating liquid during drilling, flushing up the mud. When the salt-rock was reached, a diamond drill was used to test the depth and the character of the deposit.When the well blew out and flowed freely he developed a preventer in order to save the oil and, even more importantly at the time, to shut the well and to control the oil flow. This assembly, patented in 1903, consisted of a combined system of pipes, valves and casings diverting the stream into a horizontal direction.Lucas's fame spread around the world, but as he had to relinquish the larger part of his interest to the oil company supporting the exploration, his financial reward was poor. One year after his success at Spindle Top he started oil exploration in Mexico, where he stayed until 1905, when he resumed his consulting practice in Washington, DC.[br]Bibliography1899, "Rock-salt in Louisiana", Transactions of the American Institution of Mining Engineers 29:462–74.1902, "The great oil-well near Beaumont, Texas", Transactions of the AmericanInstitution of Mining Engineers 31:362–74.Further ReadingR.S.McBeth, 1918, Pioneering the Gulf Coast, New York (a very detailed description of Lucas's important accomplishments in the development of the oil industry).R.T.Hill, 1903, "The Beaumont oil-field, with notes on other oil-fields of the Texas region", Transactions of the American Institution of Mining Engineers 33:363–405;Transactions of the American Institution of Mining Engineers 55:421–3 (contain shorter biographical notes).WK
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