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HJ Van Der Bijl
Hendrik Johannes van der Bijl FRS (23 November 1887 – 2 December 1948) was a South African electrical engineer and industrialist and is regarded as one of the greatest South Africans for his contribution to the country's development. He was the driving force behind the establishment of the South African electricity utility company Eskom and the South African Steel and Iron Corporation ISCOR. Early life and education Van der Bijl was born on 23 November 1887 in Pretoria to Pieter Gerhard van der Bijl and Plester Groenewald. He was the fifth of eight children. Pieter van der Bijl had been an ox-wagon driver between Cape Town and Kimberley and moved to Pretoria in 1887 where he became a prosperous grain and produce merchant. Pieter van der Bijl was acquainted with high-profile politicians such as Louis Botha and Jan Smuts. After the ill-fated Jameson Raid (1895) there was increased tension in the Transvaal Republic, of which Pretoria was the capital, and the young Van der Bijl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pretoria
Pretoria () is South Africa's administrative capital, serving as the seat of the Executive (government), executive branch of government, and as the host to all foreign embassies to South Africa. Pretoria straddles the Apies River and extends eastward into the foothills of the Magaliesberg mountains. It has a reputation as an academic city and center of research, being home to the Tshwane University of Technology (TUT), the University of Pretoria (UP), the University of South Africa (UNISA), the Council for Scientific and Industrial Research (CSIR), and the Human Sciences Research Council. It also hosts the National Research Foundation (South Africa), National Research Foundation and the South African Bureau of Standards. Pretoria was one of the host cities of the 2010 FIFA World Cup. Pretoria is the central part of the City of Tshwane Metropolitan Municipality which was formed by the amalgamation of several former local authorities, including Bronkhorstspruit, Centurion, Gaute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gordon's Bay
Gordon's Bay ( af, Gordonsbaai) is a harbour town in the Western Cape province of South Africa. It is included in the City of Cape Town metropolitan municipality as a suburb of the Helderberg region (formerly called Hottentots Holland). It is situated on the shores of Gordon's Bay in the northeastern corner of False Bay about 58 km from Cape Town to the south of the N2 national road and is named after Robert Jacob Gordon (1743–1795), the Dutch explorer of Scottish descent. Gordon's Bay is the smallest of three towns in the Helderberg region (Somerset West, Strand and Gordon's Bay), so named after the Helderberg Mountain which is part of the Hottentots-Holland Mountains which border the locality on two sides. Gordon's Bay was originally named "Fish Hoek", many years before the town of the same name, located on the western side of False Bay, was founded. Evidence of this can be seen on the outside wall of the local Post Office. Gordon's Bay consists of the old village, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Andrews Millikan
Robert Andrews Millikan (March 22, 1868 – December 19, 1953) was an American experimental physicist honored with the Nobel Prize for Physics in 1923 for the measurement of the elementary electric charge and for his work on the photoelectric effect. Millikan graduated from Oberlin College in 1891 and obtained his doctorate at Columbia University in 1895. In 1896 he became an assistant at the University of Chicago, where he became a full professor in 1910. In 1909 Millikan began a series of experiments to determine the electric charge carried by a single electron. He began by measuring the course of charged water droplets in an electric field. The results suggested that the charge on the droplets is a multiple of the elementary electric charge, but the experiment was not accurate enough to be convincing. He obtained more precise results in 1910 with his famous oil-drop experiment in which he replaced water (which tended to evaporate too quickly) with oil. In 1914 Millikan took ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Hallwachs
Wilhelm Ludwig Franz Hallwachs (9 July 1859 – 20 June 1922) was a German physicist. Life and career Early years Hallwachs was born in 1859 in Darmstadt to Ludwig and Emilie Hallwachs. His father was a high ranking public official ( Geheimer Staatsrat) with the Ministry of the Interior and Justice of the Grand Duchy of Hesse, then part of the German Confederation. Career From 1878 Hallwachs studied physics, most of his time at the University of Strasbourg, then part of Germany he also did one year at the University of Berlin. At last he was an assistant to August Kundt at Strasbourg where he was awarded a doctorate in 1893. Hallwachs moved on to become an assistant to Friedrich Kohlrausch at the University of Würzburg where he stayed there from 1884 until 1886. In 1886, he went to Leipzig where he habilitated with Gustav Heinrich Wiedemann until 1888. After that he followed Friedrich Kohlrausch in Strasbourg. Hallwachs became a professor at the Dresden University of T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dresden
Dresden (, ; Upper Saxon: ''Dräsdn''; wen, label=Upper Sorbian, Drježdźany) is the capital city of the German state of Saxony and its second most populous city, after Leipzig. It is the 12th most populous city of Germany, the fourth largest by area (after Berlin, Hamburg and Cologne), and the third most populous city in the area of former East Germany, after Berlin and Leipzig. Dresden's urban area comprises the towns of Freital, Pirna, Radebeul, Meissen, Coswig, Radeberg and Heidenau and has around 790,000 inhabitants. The Dresden metropolitan area has approximately 1.34 million inhabitants. Dresden is the second largest city on the River Elbe after Hamburg. Most of the city's population lives in the Elbe Valley, but a large, albeit very sparsely populated area of the city east of the Elbe lies in the West Lusatian Hill Country and Uplands (the westernmost part of the Sudetes) and thus in Lusatia. Many boroughs west of the Elbe lie in the foreland of the Ore Mounta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TU Dresden
TU Dresden (for german: Technische Universität Dresden, abbreviated as TUD and often wrongly translated as "Dresden University of Technology") is a public research university, the largest institute of higher education in the city of Dresden, the largest university in Saxony and one of the 10 largest universities in Germany with 32,389 students . The name Technische Universität Dresden has only been used since 1961; the history of the university, however, goes back nearly 200 years to 1828. This makes it one of the oldest colleges of technology in Germany, and one of the country’s oldest universities, which in German today refers to institutes of higher education that cover the entire curriculum. The university is a member of TU9, a consortium of the nine leading German Institutes of Technology. The university is one of eleven German universities which succeeded in the Excellence Initiative in 2012, thus getting the title of a "University of Excellence". The TU Dresden succee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dielectric
In electromagnetism, a dielectric (or dielectric medium) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor, because they have no loosely bound, or free, electrons that may drift through the material, but instead they shift, only slightly, from their average equilibrium positions, causing dielectric polarisation. Because of dielectric polarisation, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field (for example, if the field is moving parallel to the positive ''x'' axis, the negative charges will shift in the negative ''x'' direction). This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly bonded molecules, those molecules not only become polaris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radium
Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are radioactive, the most stable isotope being radium-226 with a half-life of 1600 years. When radium decays, it emits ionizing radiation as a by-product, which can excite fluorescent chemicals and cause radioluminescence. Radium, in the form of radium chloride, was discovered by Marie and Pierre Curie in 1898 from ore mined at Jáchymov. They extracted the radium compound from uraninite and published the discovery at the French Academy of Sciences five days later. Radium was isolated in its metallic state by Marie Curie and André-Louis Debierne through the electrolysis of radium chloride in 1911. In nature, radium is found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ions
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Triode Vacuum Tube Collection
{{disambiguation, geo ...
Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early Branch, a stream in Missouri * Early County, Georgia Other uses * ''Early'' (Scritti Politti album), 2005 * ''Early'' (A Certain Ratio album), 2002 * Early (name) * Early effect, an effect in transistor physics * Early Records, a record label * the early part of the morning See also * Earley (other) Earley is a town in England. Earley may also refer to: * Earley (surname), a list of people with the surname Earley * Earley (given name), a variant of the given name Earlene * Earley Lake, a lake in Minnesota *Earley parser, an algorithm *Earley ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Luther University Of Halle-Wittenberg
Martin Luther University of Halle-Wittenberg (german: Martin-Luther-Universität Halle-Wittenberg), also referred to as MLU, is a public, research-oriented university in the cities of Halle and Wittenberg and the largest and oldest university in the German state of Saxony-Anhalt. MLU offers German and international (English) courses leading to academic degrees such as BA, BSc, MA, MSc, doctoral degrees, and Habilitation. The university was created in 1817 through the merger of the University of Wittenberg (founded in 1502) and the University of Halle (founded in 1694). MLU is named after Protestant reformer Martin Luther, who was a professor in Wittenberg. Today, the university campus is located in Halle, while ''Leucorea Foundation'' in Wittenberg serves as MLU's convention centre. Both Halle and Wittenberg are about one hour from Berlin via the Berlin–Halle railway, which offers Intercity-Express (ICE) trains. History University of Wittenberg (''Universität Wittenbe ... [...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] |
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