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Hermann Josef Schnell
Hermann Schnell ( 16. September March 1916 – 7 September 1999) was a German organic chemist who developed the first commercial polycarbonate, Makrolon. Hermann Schnell studied chemistry at the University of Freiberg. His supervisor was Hermann Staudinger a well-known polymer chemist. After his phd he worked in the research laboratory of the Bayer AG in Uerdingen, starting in 1946. In 1953 he developed the synthesis of polycarbonates by reacting phosgene with bisphenol A. This material marketed as Makrolon was a commercial success. References * [Baidu] |
Gaienhofen
Gaienhofen is a municipality in the district of Konstanz in Baden-Württemberg in Germany. It is located at the border with Switzerland. Since 1974, Gaienhofen consists of four villages: Gaienhofen, Gundholzen, Hemmenhofen and Horn. Attractions, apart from the Lake of Constance, include the Hermann-Hesse-Höri-Museum and the Museum Haus Dix. World heritage site It is home to one or more prehistoric pile-dwelling (or stilt house) settlements that are part of the Prehistoric Pile dwellings around the Alps UNESCO World Heritage Site. Twin towns Gaienhofen is twinned with: * Saint-Georges-de-Didonne, France * Balatonföldvár, Hungary See also *Erich Heckel *Hermann Hesse Gallery File:Hornstaadhaus und Arbonhaus Unteruhldingen.jpg, Stone Age housings (reconstructed) in Unteruhldingen File:Öhningen-Wangen 229-2.jpg, Chapel in Gaienhofen-Hemmenhofen File:Hesse Wohnhaus I Gaienhofen.jpg, First house of Hermann Hesse Hermann Karl Hesse (; 2 July 1877 – 9 August 1962) wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Freiberg
The Technische Universität Bergakademie Freiberg (abbreviation: TU Bergakademie Freiberg, TUBAF) is a public university of technology with currently 3655 students in the city of Freiberg, Saxony, Germany. Its focus is on exploration, mining & extraction, processing, and recycling of natural resources & scrap, as well as developing new materials. Today, it's the oldest university of mining and metallurgy in the world. History Before 1945 The institution was established in 1765, during the Age of Enlightenment, by Prince Francis Xavier of Saxony based on plans by Friedrich Wilhelm von Oppel and Friedrich Anton von Heynitz, then called ''Kurfürstlich-Sächsische Bergakademie zu Freiberg'' (by 1806: ''Königlich-Sächsische Bergakademie zu Freiberg''). Its main purpose was the education of highly skilled miners and scientists in fields connected to mining and metallurgy. There had developed a need for mining as an industry to regenerate Saxony's economy, since Saxony had been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of The University Of Freiburg
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation, de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1999 Deaths
File:1999 Events Collage.png, From left, clockwise: The funeral procession of King Hussein of Jordan in Amman; the 1999 İzmit earthquake kills over 17,000 people in Turkey; the Columbine High School massacre, one of the first major school shootings in the United States; the Year 2000 problem ("Y2K"), perceived as a major concern in the lead-up to the year 2000; the Millennium Dome opens in London; online music downloading platform Napster is launched, soon a source of online piracy; NASA loses both the Mars Climate Orbiter and the Mars Polar Lander; a destroyed T-55 tank near Prizren during the Kosovo War., 300x300px, thumb rect 0 0 200 200 Death and state funeral of King Hussein rect 200 0 400 200 1999 İzmit earthquake rect 400 0 600 200 Columbine High School massacre rect 0 200 300 400 Kosovo War rect 300 200 600 400 Year 2000 problem rect 0 400 200 600 Mars Climate Orbiter rect 200 400 400 600 Napster rect 400 400 600 600 Millennium Dome 1999 was designated as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1916 Births
Events Below, the events of the First World War have the "WWI" prefix. January * January 1 – The British Empire, British Royal Army Medical Corps carries out the first successful blood transfusion, using blood that had been stored and cooled. * January 9 – WWI: Gallipoli Campaign: The last British troops are evacuated from Gallipoli, as the Ottoman Empire prevails over a joint British and French operation to capture Constantinople. * January 10 – WWI: Erzurum Offensive: Russia defeats the Ottoman Empire. * January 12 – The Gilbert and Ellice Islands Colony, part of the British Empire, is established in present-day Tuvalu and Kiribati. * January 13 – WWI: Battle of Wadi (1916), Battle of Wadi: Ottoman Empire forces defeat the British, during the Mesopotamian campaign in modern-day Iraq. * January 29 – WWI: Paris is bombed by German Empire, German zeppelins. * January 31 – WWI: An attack is planned on Verdun, France. February * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol A
Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on an industrial scale by the condensation of phenol and acetone, and has a global production scale which is expected to reach 10 million tonnes in 2022. BPA's largest single application is as a co-monomer in the production of polycarbonates, which accounts for 65–70% of all BPA production. The manufacturing of epoxy resins and vinyl ester resins account for 25–30% of BPA use. The remaining 5% is used as a major component of several high-performance plastics, and as a minor additive in PVC, polyurethane, thermal paper, and several other materials. It is not a plasticizer, although it is often wrongly labelled as such. The health effects of BPA have been the subject of prolonged public and scientific debate. BPA is a xenoestrogen, exhibiting hormone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosgene
Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, especially for the production of precursors of polyurethanes and polycarbonate plastics. Phosgene is extremely poisonous and was used as a chemical weapon during World War I, where it was responsible for 85,000 deaths. It was a highly potent pulmonary irritant and quickly filled enemy trenches due to it being a heavy gas. It is classified as a Schedule 3 substance under the Chemical Weapons Convention. In addition to its industrial production, small amounts occur from the breakdown and the combustion of organochlorine compounds, such as chloroform. Structure and basic properties Phosgene is a planar molecule as predicted by VSEPR theory. The C=O distance is 1.18 Å, the C−Cl distance is 1.74 Å and the Cl−C−Cl angle is 111 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uerdingen
Uerdingen () is a district of the city of Krefeld, Germany, with a population of 17,888 (2019). Originally a separate city in its own right, Uerdingen merged with the city of Krefeld in 1929. Today, Uerdingen is best known for a local distillery and a railcar factory, and is the eponym of the Uerdingen line. History The earliest archeological artifacts found in Uerdingen date to the first century CE, and are now found in the British museum. The size and permanence of the associated settlement, however, remain unclear, partly because the site was also a camp for the Roman Legion. Records attest that the commander 89 CE was Marcus Hordeonius Flaccus; his nickname ("Castra Ordeonii") has been proposed as an etymon for "Uerdingen". The earliest reference to a permanent settlement in the Krefeld-Uerdingen area dates to 809: the city charter for Friemersheim describes a nearby town as "Urdingi". By the mid-thirteenth century, Uerdingen was a thriving port, serving the Rhine river ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Makrolon
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed. Because of these properties, polycarbonates find many applications. Polycarbonates do not have a unique resin identification code (RIC) and are identified as "Other", 7 on the RIC list. Products made from polycarbonate can contain the precursor monomer bisphenol A (BPA). Structure Carbonate esters have planar OC(OC)2 cores, which confers rigidity. The unique O=C bond is short (1.173 Å in the depicted example), while the C-O bonds are more ether-like (the bond distances of 1.326 Å for the example depicted). Polycarbonates received their name because they are polymers containing carbonate groups (−O−(C=O)−O−). A balance of useful features, including temperature resistance, impact resistance and op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its financial centre is Frankfurt; the largest urban area is the Ruhr. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycarbonate
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed. Because of these properties, polycarbonates find many applications. Polycarbonates do not have a unique resin identification code (RIC) and are identified as "Other", 7 on the RIC list. Products made from polycarbonate can contain the precursor monomer bisphenol A (BPA). Structure Carbonate esters have planar OC(OC)2 cores, which confers rigidity. The unique O=C bond is short (1.173 Å in the depicted example), while the C-O bonds are more ether-like (the bond distances of 1.326 Å for the example depicted). Polycarbonates received their name because they are polymers containing carbonate groups (−O−(C=O)−O−). A balance of useful features, including temperature resistance, impact resistance and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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