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Swim Fins
Swimfins, swim fins, diving fins, or flippers are finlike accessories worn on the feet, legs or hands and made from rubber, plastic, carbon fiber or combinations of these materials, to aid movement through the water in water sports activities such as swimming, bodyboarding, bodysurfing, float-tube fishing, kneeboarding, riverboarding, scuba diving, snorkeling, spearfishing, underwater hockey, underwater rugby and various other types of underwater diving. Swimfins help the wearer to move through water more efficiently, as human feet are too small and inappropriately shaped to provide much thrust, especially when the wearer is carrying equipment that increases hydrodynamic drag. Very long fins and monofins used by freedivers as a means of underwater propulsion do not require high-frequency leg movement. This improves efficiency and helps to minimize oxygen consumption. Short, stiff-bladed fins are effective for short bursts of acceleration and maneuvering, and are useful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Types of polyisoprene that are used as natural rubbers are classified as elastomers. Currently, rubber is harvested mainly in the form of the latex from the Hevea brasiliensis, Pará rubber tree (''Hevea brasiliensis'') or others. The latex is a sticky, milky and white colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". Manufacturers refine this latex into the rubber that is ready for commercial processing. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials. In most of its useful forms, it has a large stretch ratio and high resilience and also is buoyant and water-proof. Industrial demand for rubber-like materials began to out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foot
The foot (: feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is an organ at the terminal part of the leg made up of one or more segments or bones, generally including claws and/or nails. Etymology The word "foot", in the sense of meaning the "terminal part of the leg of a vertebrate animal" comes from Old English ''fot'', from Proto-Germanic *''fot'' (source also of Old Frisian ''fot'', Old Saxon ''fot'', Old Norse ''fotr'', Danish ''fod'', Swedish ''fot'', Dutch ''voet'', Old High German ''fuoz'', German ''Fuß'', Gothic ''fotus'', all meaning "foot"), from PIE root *''ped-'' "foot". The plural form ''feet'' is an instance of i-mutation. Structure The human foot is a strong and complex mechanical structure containing 26 bones, 33 joints (20 of which are actively articulated), and more than a hundred muscles, tendons, and ligaments.Podiatry Chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palette (painting)
A palette () is a surface on which a painter arranges and mixes paints. A palette is made of materials such as wood, paper, glass, ceramic or plastic, and can vary greatly in size and shape. Watercolor palettes are generally made of plastic or porcelain in a rectangular or wheel format, and have built in wells and mixing areas for colors. For acrylic painting, "stay wet" palettes exist, which prevent the paints from drying out and becoming inert. A classical palette is most often oval, but can also be rectangular, and is tapered to ensure optimal distribution of weight. It has a thumbhole and insert for brushes, and is designed to be held in the non-dominant hand while the other is used to mix and paint. However, some well-known artists have used more unconventional palettes; for instance, Picasso used a sheet of newspaper. Palettes are also a universal symbol of painting and art in general, alongside paintbrushes, for example in the symbol of Microsoft Paint. See also * Palet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles River
The Charles River (Massachusett language, Massachusett: ), sometimes called the River Charles or simply the Charles, is an river in eastern Massachusetts. It flows northeast from Hopkinton, Massachusetts, Hopkinton to Boston along a highly meandering route, that doubles back on itself several times and travels through 23 cities and towns before reaching the Atlantic Ocean. The indigenous Massachusett named it , meaning "meandering" or "meandering still water". Hydrography The Charles River is fed by approximately eighty streams and several major aquifers as it flows , starting at Teresa Road just north of Echo Lake (Hopkinton), Echo Lake () in Hopkinton, passing through 23 cities and towns in eastern Massachusetts before emptying into Boston Harbor. Thirty-three lakes and ponds and 35 municipalities are entirely or partially part of the Charles River drainage basin. Despite the river's length and relatively large drainage area (), its source is only from its mouth, and the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston, Massachusetts
Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeastern United States. It has an area of and a population of 675,647 as of the 2020 United States census, 2020 census, making it the third-largest city in the Northeastern United States after New York City and Philadelphia. The larger Greater Boston metropolitan statistical area has a population of 4.9 million as of 2023, making it the largest metropolitan area in New England and the Metropolitan statistical area, eleventh-largest in the United States. Boston was founded on Shawmut Peninsula in 1630 by English Puritans, Puritan settlers, who named the city after the market town of Boston, Lincolnshire in England. During the American Revolution and American Revolutionary War, Revolutionary War, Boston was home to several seminal events, incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benjamin Franklin
Benjamin Franklin (April 17, 1790) was an American polymath: a writer, scientist, inventor, statesman, diplomat, printer, publisher and Political philosophy, political philosopher.#britannica, Encyclopædia Britannica, Wood, 2021 Among the most influential intellectuals of his time, Franklin was one of the Founding Fathers of the United States; a Committee of Five, drafter and signer of the United States Declaration of Independence, Declaration of Independence; and the first United States Postmaster General, postmaster general. Born in the Province of Massachusetts Bay, Franklin became a successful Early American publishers and printers, newspaper editor and printer in Philadelphia, the leading city in the colonies, publishing ''The Pennsylvania Gazette'' at age 23. He became wealthy publishing this and ''Poor Richard's Almanack'', which he wrote under the pseudonym "Richard Saunders". After 1767, he was associated with the ''Pennsylvania Chronicle'', a newspaper known for it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siebe Gorman
Siebe Gorman & Company Ltd was a British company that developed diving equipment and breathing equipment and worked on commercial diving and marine salvage projects. The company advertised itself as 'Submarine Engineers'. It was founded by Augustus Siebe, a Germany, German-born British engineer chiefly known for his contributions to diving equipment. Siebe plc started in the 1970s as a continuation of Siebe Gorman when Siebe Gorman started to take over other firms, to mean the new conglomerate to distinguish it from Siebe Gorman's original breathing apparatus and diving gear core business. Siebe plc was once one of the United Kingdom's largest engineering businesses. It was a constituent of the FTSE 100 Index but in 1999 it merged with BTR plc to form Invensys. Invensys was taken over by the French multinational Schneider Electric for £3.4 billion in January 2014. History *1788: Augustus Siebe was born in Saxony in Germany, named Christian Augustus Siebe.pages 16 etseq, ''The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duck
Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfamilies, they are a form taxon; they do not represent a monophyletic group (the group of all descendants of a single common ancestral species), since swans and geese are not considered ducks. Ducks are mostly aquatic birds, and may be found in both fresh water and sea water. Ducks are sometimes confused with several types of unrelated water birds with similar forms, such as loons or divers, grebes, gallinules and coots. Etymology The word ''duck'' comes from Old English 'diver', a derivative of the verb 'to duck, bend down low as if to get under something, or dive', because of the way many species in the dabbling duck group feed by upending; compare with Dutch language, Dutch and German language, German 'to dive'. This word replaced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giovanni Alfonso Borelli
Giovanni Alfonso Borelli (; 28 January 1608 – 31 December 1679) was a Renaissance Italy, Italian physiologist, physicist, and mathematician who is often described as the father of biomechanics. He contributed to the modern principle of scientific investigation by continuing Galileo Galilei, Galileo's practice of testing hypotheses against observation. Trained in mathematics, Borelli also made extensive studies of Jupiter's moons, the mechanics of animal locomotion and, in microscopy, of the constituents of blood. He also used microscopy to investigate the stomatal movement of plants, and undertook studies in medicine and geology. During his career, he enjoyed the patronage of Queen Christina of Sweden. He was the first scientist to explain that animal and human bodily movements are caused by muscular contractions. Biography Giovanni Borelli was born on 28 January 1608 in the district of Castel Nuovo, in Naples. He was the first-born son of Spanish infantryman Miguel Alfonso and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonardo Da Vinci
Leonardo di ser Piero da Vinci (15 April 1452 - 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested on his achievements as a painter, he has also become known for #Journals and notes, his notebooks, in which he made drawings and notes on a variety of subjects, including anatomy, astronomy, botany, cartography, painting, and palaeontology. Leonardo is widely regarded to have been a genius who epitomised the Renaissance humanism, Renaissance humanist ideal, and his List of works by Leonardo da Vinci, collective works comprise a contribution to later generations of artists matched only by that of his younger contemporary Michelangelo. Born out of wedlock to a successful notary and a lower-class woman in, or near, Vinci, Tuscany, Vinci, he was educated in Florence by the Italian painter and sculptor Andrea del Verrocchio. He began his career ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
