A cat’s-whisker detector (sometimes called a crystal detector) is an antique electronic component consisting of a thin wire that lightly touches a crystal of semiconducting mineral (usually galena) to make a crude point-contact rectifier. Developed by early radio researchers Henry H. C. Dunwoody‚ G. W. Pickard and others‚ this device was used as the detector in early crystal radios‚ from about 1906 through the Second World War‚ and gave this type of radio receiver its name. Crystal radios were the
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How great a role did the abolitionists play in ending slavery in the British West Indies in 1834? The abolitionists played a very vital role in the abolition of the slave trade and the abolition of slavery itself. The movement to end slavery began in 1823 with the formation of the Society for Mitigation and Gradual Abolition of Slavery and the efforts continued with the Agency Committee formed in 1831.There were other mitigating circumstances which also favored the abolitionists such as the Reform
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Tantalum Tantalum is a shiny‚ silvery metal which is soft when is pure. It is almost immune to chemical attack at temperatures below 150 C. Tantalum is virtually resistant to corrosion due to an oxide film on its surface. Applications Tantalum finds use in four areas: high-temperature applications‚ such as aircraft engines; electrical devices‚ such as capacitors; sirurgical impants and handling corrosive chemicals. It is rarely used as an alloying agent because it tends to make metals brittle
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Egyptian Fashion Egyptian Clothing The main focus of Egyptian clothing was to keep cool under the hot Egyptian sun; they idolized the human body and had physical ideals that are very similar to the ones we hold today. The clothing that they wore complimented the lines of a slender figure and was often adorned with gems and jewels if they were rich. These ideas helped name ancient Egyptians the very first society to have an identifiable style among the ancient civilizations. Materials The
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streptelasma‚ an unnamed bivalve‚ bryozoans‚ various crinoid stem parts‚ the cephalopod endoceras‚ and the gastropods cyclonema and malcurites. The rock types and formations that were found around these fossils were Cincinnatian Maquoketa Shale and Galena Dolomite. “The Maquoketa shale‚ which contains seams of argillaceous dolomite…and ranges from highly to slightly weathered‚ with the highly weathered portions having the consistency of a stiff clay and are extremely fissile” (Preber). These fossils
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Name: __Huram-abi ________________________ Date: 9/20/2012______________________ Student Exploration: Mineral Identification Vocabulary: crystal‚ density‚ hardness‚ homogeneous‚ luster‚ mass‚ mineral‚ streak‚ volume Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Suppose you find a yellow piece of metal in a stream. How could you tell if it is real gold? _To tell if it’s real gold check out it’s density‚ find it’s mass and volume‚ see if it’s luster
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without metal. The metals we use in our houses are mostly for keeping them sturdy. Though there is one problem we have when it comes to metals. That problem is that they rust. Metals rust when they are in contact with oxygen‚ and water. They rust much faster when they are in contact with salt water‚ and acid rain. We chose to see what would happen to various metals when they contacted with salt water. When the electrons move around in the salt water‚ it causes the metals to rust. The metals we chose
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Union Pacific Railroad was established through the purchase of former railroads which were the Southern Pacific‚ Missouri Pacific‚ Chicago and North Western Railroads. The railroad was first established in 1848 when the first ten miles of Galena and Chicago Union Railroad were completed‚ a direct predecessor of the Chicago & north Western (Union Pacific‚ 2006). The main turning point for the railroad system was put into place in 1862 when the sixteenth President of the United States‚ Abraham
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Non Marital Relationship live in partner Cohabitation is an arrangement whereby two people decide to live together on a long-term or permanent basis in an emotionally and/or sexually intimate relationship. The term is most frequently applied to couples who are not married Reason for Cohabitation Today‚ cohabitation is a common pattern among people in the Western world. People may live together for a number of reasons. These may include wanting to test compatibility or to establish financial
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Mascara is a cosmetic commonly used to enhance the eyes. It may darken‚ thicken‚ lengthen‚ and/or define the eyelashes. Normally in one of three forms—liquid‚ cake‚ or cream—the modern mascara product has various formulas; however‚ most contain the same basic components of pigments‚ oils‚ waxes‚ and preservatives. Definition The Collins English Dictionary defines mascara as "a cosmetic substance for darkening‚ curling‚ coloring‚ and thickening the eyelashes‚ applied with a brush or rod." The
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