Descriptions of inventions / discoveries <ul><li>Examples of </li></ul><ul><li>good and bad practice … </li></ul>
Example 1 My description of an invention <ul><li>Whitcomb L. Judson (1836-1909) was an American inventor, born in Chicago, Illinois. Whitcomb is most famous for inventing the forerunner of the modern zipper in 1893, which he called the clasp-locker. He also invented the Pneumatic Street Railway. During his lifetime, he obtained patents for the zipper, motor improvements and railroad brakes improvements. He also made a number of automobile improvements, one of which made his son a millionaire. </li></ul>
EXAMPLE 2 The Discovery of Radioactivity It's been 100 years since the discovery of radioactivity. Happy 100th Birthday! This section will describe the surprise discovery of radiation and the significant contributions of several other scientists. How exciting it must have been for them to be on the forefront of such new and exciting research! Little did they know how much their discoveries would benefit mankind 100 years in the future.
<ul><li>It was the month of February in the year of 1896. Antoine Henri Becquerel, a French scientist, was conducting an experiment which started with the exposure of a uranium-bearing crystal to sunlight. Once the crystal had sat in the sunshine for a while, he placed it on a photographic plate. As he had anticipated, the crystal produced its image on the plate. Becquerel theorized that the absorbed energy of the sun was being released by the uranium in the form of x-rays. </li></ul>
<ul><li>Further testing of this theory had to be put off for a few days because the sky had clouded up and the sun had disappeared. For the next couple of days he left his sample of uranium in a closed drawer along with the photographic plate. </li></ul><ul><li>When the weather had cleared, he returned to the drawer to retrieve his gear. He was surprised to find that the crystal had left a clear, strong image on the photographic plate. </li></ul>
<ul><li>How could this be? There was no source of energy to produce the image! What Becquerel had discovered was that a piece of mineral which contained uranium could produce it's image on a photographic plate in the absence of light. What he had discovered was radioactivity! He attributed this phenomenon to spontaneous emission by the uranium. </li></ul><ul><li>Although Becquerel did not pursue these findings, it wasn't long before others would (…) </li></ul>
Did you know this?? In 1903, Becquerel and the Curie together received the Nobel Prize in physics. This award was for their discovery of radioactivity and their other contributions in this area. Marie Curie received a second Nobel Prize in 1911 for the discovery of polonium and radium. She was the first person to win two Nobel Prizes. Did you know that the Curie's had a word named after them? That's right! The curie is a basic unit of measurement for describing radioactivity. http://www.chem.duke.edu/~jds/cruise_chem/nuclear/discovery.html
EXAMPLE 3 The Discovery of DNA In the early 1950s, the race to discover DNA was on. At Cambridge University, graduate student Francis Crick and research fellow James Watson (b. 1928) had become interested, impressed especially by Pauling's work. Meanwhile at King's College in London, Maurice Wilkins (b. 1916) and Rosalind Franklin were also studying DNA. The Cambridge team's approach was to make physical models to narrow down the possibilities and eventually create an accurate picture of the molecule. The King's team took an experimental approach, looking particularly at x-ray diffraction images of DNA. In 1951, Watson attended a lecture by Franklin on her work to date. She had found that DNA can exist in two forms, depending on the relative humidity in the surrounding air. This had helped her deduce that the phosphate part of the molecule was on the outside. Watson returned to Cambridge with a rather muddy recollection of the facts Franklin had presented, though clearly critical of her lecture style and personal appearance. Based on this information, Watson and Crick made a failed model. It caused the head of their unit to tell them to stop DNA research. But the subject just kept coming up. (…)
Example 4 The discovery of Lithium The petalite and spodumene (minerals containing lithium) were discovered by the Brazilian scientist José Bonifácio de Andrada e Sìlva at the end of the 18th century while visiting Sweden. Lithium was then discovered by Swedish scientist Johan August Arfvedson in 1817 during an analysis of petalite ore, an ore now recognised to be LiAl(Si2O5)2, taken from a Swedish island. Arfvedson subsequently discovered lithium in the minerals spodumene and lepidolite. He named new element as a lithium (from Greek word lithos meaning stone. The first isolation of elemental lithium was achieved later in 1818 by Sir Humphrey Davy by the electrolysis of Li2O. In 1855, Bunsen and Mattiessen isolated larger quantities of the metal by electrolysis of lithium chloride. Lithium metal is prepared by the electrolysis of a fused mixture of lithium chloride and potassium chloride in a cell at a temperature of about 400 °C recently.
<ul><li>However, deeper scanning of the historic materials (big thanks to Vladimír Dufek and Vlastimil Brozek from ICT at Prague) revealed that first mineral containing lithium called lilalith was found at Hradisko u Rozné close to Bystrice nad Pernštejnem in the Czech Republic. First mineral analysis was published by Klaproth in 1792, who called this mineral as lepidolith. Crystallographic analysis was published in 1798 by Wondraschek and lithium content (close to theoretical value 3.6 %) was determined by Gmelin in 1820, who noticed red colour of the flame of the lithium compounds. </li></ul>
Description Lithium has a silvery appearance but quickly becomes covered by a film of black oxide when exposed to air. It is usually stored immersed in an inert oil. Lithium is the lightest of all metals. Reacts slowly with oxygen and water. In solution, a lithium will give an intense carmine-red flame test color, the color somewhat resembling that of the strontium flame but deeper. In very small quantities it is visible using a diffraction spectroscope. The lithium minerals, which are either silicates or phosphates, do not become alkaline after ignition.
<ul><li>not too long (and not too short, of course!) </li></ul><ul><li>Structure </li></ul><ul><li>Interesting introduction that captivates the reader’s attention </li></ul><ul><li>Passion for the subject </li></ul><ul><li>Reads like a story or novel – you want to know how it ends! </li></ul><ul><li>Address / involve the reader! </li></ul><ul><li>“ Did you know…” (add interesting information that doesn’t necessarily fit into the description) </li></ul><ul><li>Invention / discovery not described </li></ul><ul><li>No transition between sentences </li></ul><ul><li>Repetitive </li></ul><ul><li>Enumeration / bullet point / list </li></ul><ul><li>Title is incongruent with content </li></ul><ul><li>Introductory sentence is boring and doesn’t captivate the reader’s attention </li></ul><ul><li>Too much detail </li></ul><ul><li>Information is too technical and makes description boring and incomprehensible for readers </li></ul>