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Warren Thompson (photographer)
Warren T. Thompson (active 1840 - 1870) was an American photographer. Between 1840 and 1846 Thompson worked in Philadelphia and in 1843 refined Daniel Davis Jr.'s electroplating Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ... method for colouring daguerreotypes by using a gum tragacanth resist. With this technique colours could be built up in the manner of some types of printmaking. According to an article in the 1892 ''American Journal of Photography'' by editor Julius Sachse, Thompson traveled to Paris in 1845 from New York without speaking any French and with an introduction from the Russian Consul in New York to the Russian Vice-Consul in Paris who in turn arranged an introduction to Russian photographer Sergei Lvovich Levitsky. Levitsky is quoted by Sachse as declaring Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philadelphia, Pennsylvania
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Since 1854, the city has been coextensive with Philadelphia County, the most populous county in Pennsylvania and the urban core of the Delaware Valley, the nation's seventh-largest and one of world's largest metropolitan regions, with 6.245 million residents . The city's population at the 2020 census was 1,603,797, and over 56 million people live within of Philadelphia. Philadelphia was founded in 1682 by William Penn, an English Quaker. The city served as capital of the Pennsylvania Colony during the British colonial era and went on to play a historic and vital role as the central meeting place for the nation's founding fathers whose plans and actions in Philadelphia ultimately inspired the American Revolution and the nation's inde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daniel Davis Jr
Daniel is a masculine given name and a surname of Hebrew origin. It means "God is my judge"Hanks, Hardcastle and Hodges, ''Oxford Dictionary of First Names'', Oxford University Press, 2nd edition, , p. 68. (cf. Gabriel—"God is my strength"), and derives from two early biblical figures, primary among them Daniel from the Book of Daniel. It is a common given name for males, and is also used as a surname. It is also the basis for various derived given names and surnames. Background The name evolved into over 100 different spellings in countries around the world. Nicknames (Dan, Danny) are common in both English and Hebrew; "Dan" may also be a complete given name rather than a nickname. The name "Daniil" (Даниил) is common in Russia. Feminine versions (Danielle, Danièle, Daniela, Daniella, Dani, Danitza) are prevalent as well. It has been particularly well-used in Ireland. The Dutch names "Daan" and "Daniël" are also variations of Daniel. A related surname developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be coated acts as the cathode (negative electrode) of an electrolytic cell; the electrolyte is a solution of a salt of the metal to be coated; and the anode (positive electrode) is usually either a block of that metal, or of some inert conductive material. The current is provided by an external power supply. Electroplating is widely used in industry and decorative arts to improve the surface qualities of objects—such as resistance to abrasion and corrosion, lubricity, reflectivity, electrical conductivity, or appearance. It is used to build up thickness on undersized or worn-out parts, or to manufacture metal plates with complex shape, a process called electroforming. It is used to deposit copper and other conductors in forming printe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tragacanth
Tragacanth is a natural gum obtained from the dried sap of several species of Middle Eastern legumes of the genus ''Astragalus'', including '' A. adscendens'', '' A. gummifer'', '' A. brachycalyx'', and '' A. tragacantha''. Some of these species are known collectively under the common names "goat's thorn" and "locoweed". The gum is sometimes called Shiraz gum, shiraz, gum elect or gum dragon. The name derives from the Greek words ''tragos'' (meaning "goat") and ''akantha'' ("thorn"). Iran is the biggest producer of this gum. Gum tragacanth is a viscous, odorless, tasteless, water-soluble mixture of polysaccharides obtained from sap that is drained from the root of the plant and dried. The gum seeps from the plant in twisted ribbons or flakes that can be powdered. It absorbs water to become a gel, which can be stirred into a paste. The major fractions are known as tragacanthin, highly water-soluble as a mucilaginous colloid, and the chemically related bassorin, which is far less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoresist
A photoresist (also known simply as a resist) is a light-sensitive material used in several processes, such as photolithography and photoengraving, to form a patterned coating on a surface. This process is crucial in the electronic industry. The process begins by coating a substrate with a light-sensitive organic material. A patterned mask is then applied to the surface to block light, so that only unmasked regions of the material will be exposed to light. A solvent, called a developer, is then applied to the surface. In the case of a positive photoresist, the photo-sensitive material is degraded by light and the developer will dissolve away the regions that were exposed to light, leaving behind a coating where the mask was placed. In the case of a negative photoresist, the photosensitive material is strengthened (either polymerized or cross-linked) by light, and the developer will dissolve away only the regions that were not exposed to light, leaving behind a coating in areas w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sergei Lvovich Levitsky
Count Sergei Lvovich Levitsky (russian: Серге́й Льво́вич Львов-Леви́цкий; 17 August 1819 – 22 June 1898), is considered one of the patriarchs of Russian Empire photography and one of Europe's most important early photographic pioneers, inventors and innovators. Early life Of noble birth, he was a cousin of Aleksandr Ivanovich Herzen (1812–1870), the writer and outstanding public figure; husband to Anna Antonovna and father to Rafail Sergeevich Levitsky (1847–1940), a Peredvizhniki artist who was court photographer to the ill fated family of Czar Nicholas II, the last emperor of Russia. Sergei was born Lvov-Lvitsky in Moscow but later changed his name to Levitsky. At his parents request he attended and graduated (1839) from the Faculty of Law, Lomonosov Moscow State University and soon after served in the Russian civil service with the Ministry of the Interior, St. Petersburg. His ability to speak several languages allowed him to participate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
