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Suction Cup
A suction cup, also known as a sucker, is a device or object that uses the negative Pressure#Fluid pressure, fluid pressure of air or water to adhere to Porosity, nonporous surfaces, creating a Vacuum, partial vacuum. Suction cups are peripheral traits of some animals such as octopuses and squids, and have been reproduced artificially for numerous purposes. Theory The working face of the suction cup is made of elastic, flexible material and has a curved surface. When the center of the suction cup is pressed against a flat, non-porous surface, the volume of the space between the suction cup and the flat surface is reduced, which causes the air or water between the cup and the surface to be expelled past the rim of the circular cup. The cavity which develops between the cup and the flat surface has little to no air or water in it because most of the fluid has already been forced out of the inside of the cup, causing a lack of pressure. The pressure difference between the atmos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suction Cup 1
Suction is the colloquial term to describe the air pressure differential between areas. Removing air from a space results in a Pressure gradient, pressure differential. Suction pressure is therefore limited by external air pressure. Even a perfect vacuum cannot suck with more pressure than is available in the surrounding environment. Suctions can form on the sea, for example, when a ship founders. When the pressure in one part of a physical system is reduced relative to another, the fluid in the higher pressure region will exert a force relative to the region of lowered pressure, referred to as pressure-gradient force. Pressure reduction may be Static pressure, static, as in a piston and cylinder arrangement, or Dynamic pressure, dynamic, as in the case of a vacuum cleaner when air flow results in a reduced pressure region. When animals breathe, the Thoracic diaphragm, diaphragm and muscles around the rib cage cause a change of volume in the lungs. The increased volume of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippocrates
Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history of medicine. He is traditionally referred to as the "Father of Medicine" in recognition of his lasting contributions to the field, such as the use of prognosis and clinical observation, the systematic categorization of diseases, or the formulation of humoral theory. The Hippocratic school of medicine revolutionized ancient Greek medicine, establishing it as a discipline distinct from other fields with which it had traditionally been associated ( theurgy and philosophy), thus establishing medicine as a profession. However, the achievements of the writers of the Hippocratic Corpus, the practitioners of Hippocratic medicine, and the actions of Hippocrates himself were often conflated; thus very little is known about what Hippocrates actual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-sealing Suction Cup
The self-sealing suction cup is a suction cup that exerts a suction force only when it is in physical contact with an object. Unlike most other suction cups, it does not exert any suction force when it is not in contact with an object. Its grasping ability is achieved entirely through passive means without the use of sensors, valves, or actuators. It was designed so that, when used as part of a suction cup array, the suction cups that don't come in contact with the object remain sealed. By having only the suction cups that are in direct contact of the object to exhibit suction force, the researchers were able to minimize leak points where air could enter and increase the pressure that each active cup receives, maximizing the suction force. As a result, an array of self-sealing suction cups can grasp and pick up a wide range of object sizes and shapes. This comes in contrast to conventional suction cups that are typically designed for one specific object size and geometry. In addition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magdeburg Hemispheres
The Magdeburg hemispheres are a pair of large copper hemispheres, with mating rims. They were used to demonstrate the power of atmospheric pressure. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart by teams of horses in a famous first public demonstration in 1654. The Magdeburg hemispheres were invented by German scientist and mayor of Magdeburg, Otto von Guericke, to demonstrate the air pump that he had invented, and the concept of atmospheric pressure. The first artificial vacuum had been produced a few years earlier by Evangelista Torricelli, and had inspired Guericke to design the world's first vacuum pump, which consisted of a piston and cylinder with one-way flap valves. The hemispheres became popular in physics lectures as an illustration of the strength of air pressure, and are still used in education. The original hemispheres are on display in the Deutsches Museum in Munich. Aside from its sci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horror Vacui (physics)
In physics, horror vacui, or plenism (), commonly stated as "nature abhors a vacuum", is a postulate attributed to Aristotle, who articulated a belief, later criticized by the atomism of Epicurus and Lucretius, that nature contains no vacuums because the denser surrounding material continuum would immediately fill the rarity of an incipient void. He also argued against the void in a more abstract sense (as "separable"), for example, that by definition a void (equivocally?) itself, is nothing, and following Plato, nothing cannot rightly be said to exist. Furthermore, insofar as it would be featureless, it could neither be encountered by the senses, nor could its supposition lend additional explanatory power. Hero of Alexandria challenged the theory in the first century AD, but his attempts to create an artificial vacuum failed. The theory was debated in the context of 17th-century fluid mechanics, by Thomas Hobbes and Robert Boyle, among others, and through the early 18th centu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Trade Center (1973–2001)
The original World Trade Center (WTC) was a large complex of seven buildings in the Financial District of Lower Manhattan in New York City. It opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. At the time of their completion, the Twin Towers—the original 1 World Trade Center (the North Tower) at ; and 2 World Trade Center (the South Tower) at —were the tallest buildings in the world. Other buildings in the complex included the Marriott World Trade Center (3 WTC), 4 WTC, 5 WTC, 6 WTC, and 7 WTC. The complex contained of office space. The core complex was built between 1966 and 1975, at a cost of $400 million (equivalent to $3.56 billion in 2022). The idea was suggested by David Rockefeller to help stimulate urban renewal in Lower Manhattan, and his brother Nelson signed the legislation to build it. The buildings at the complex were designed by Minoru Yamasaki. In 1998, the Port Authority of New York and New Jersey d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bonaventure Hotel
The Westin Bonaventure Hotel and Suites is a , 33- story hotel in Los Angeles, California, constructed between 1974 and 1976. It was designed by architect John C. Portman Jr.. The top floor has a revolving restaurant and bar. It was originally owned by investors that included a subsidiary of Japanese conglomerate Mitsubishi Corporation and John Portman & Associates. The building is managed by Interstate Hotels & Resorts (IHR), and is valued at 200 million USD. Postmodern design The hotel and its architect John Portman have been the subject of documentaries and academic analysis. In his book ''Postmodern Geographies: The Reassertion of Space in Critical Social Theory'' (1989), Edward Soja describes the hotel as a concentrated representation of the restructured spatiality of the late capitalist city: fragmented and fragmenting, homogeneous and homogenizing, divertingly packaged yet curiously incomprehensible, seemingly open in presenting itself to view but constantly pressing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sears Tower
The Willis Tower (originally the Sears Tower) is a 108- story, skyscraper in the Loop community area of Chicago in Illinois, United States. Designed by architect Bruce Graham and engineer Fazlur Rahman Khan of Skidmore, Owings & Merrill (SOM), it opened in 1973 as the world's tallest building, a title that it held for nearly 25 years. It is currently the third-tallest building in the Western Hemisphere, as well as the 23rd-tallest in the world. Each year, more than 1.7 million people visit the Skydeck observation deck, the highest in the United States, making it one of Chicago's most popular tourist destinations. The building occupies a site bounded by Franklin Street, Jackson Boulevard, Wacker Drive, and Adams Street. Graham and Khan designed the building as nine square " tubes", clustered in a 3×3 matrix; seven of the tubes set back at upper floors. The tower has 108 stories as counted by standard methods, though the building's owners count the main roof as 109 and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dan Goodwin
Daniel Goodwin (born November 7, 1955 in Kennebunkport, Maine) is an American climber best known for performing gymnastic-like flag maneuvers and one arm flyoffs while free soloing difficult rock climbs on national TV and for scaling towering skyscrapers, including the Sears Tower, the John Hancock Center, the World Trade Center, the CN Tower, and (for the program ''Stan Lee's Superhumans'') the Telefónica Building in Santiago, Chile. Building climber On November 21, 1980, Dan Goodwin witnessed the MGM Grand fire in Las Vegas, Nevada, United States, including the inability of the Clark County Fire Department and the supporting fire departments to rescue scores of hotel guests trapped inside. Believing he knew how to rescue the trapped people, Goodwin presented a rescue plan to the on-location fire boss. Goodwin's plan included his climbing up the building and connecting cables to the floors to enable rescue baskets to be ferried to and from helicopters. The fire boss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBC News
BBC News is an operational business division of the British Broadcasting Corporation (BBC) responsible for the gathering and broadcasting of news and current affairs in the UK and around the world. The department is the world's largest broadcast news organisation and generates about 120 hours of radio and television output each day, as well as online news coverage. The service maintains 50 foreign news bureaus with more than 250 correspondents around the world. Deborah Turness has been the CEO of news and current affairs since September 2022. In 2019, it was reported in an Ofcom report that the BBC spent £136m on news during the period April 2018 to March 2019. BBC News' domestic, global and online news divisions are housed within the largest live newsroom in Europe, in Broadcasting House in central London. Parliamentary coverage is produced and broadcast from studios in London. Through BBC English Regions, the BBC also has regional centres across England and national new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buildering
Buildering (also known as edificeering, urban climbing, structuring, skywalking, boulding, or stegophily) describes the act of climbing on the outside of buildings and other artificial structures. The word "buildering", sometimes misspelled bildering, combines the word '' building'' with the climbing term ''bouldering''. If done without ropes or protection far off the ground, buildering is extremely dangerous. It is often practiced outside legal bounds, and is thus mostly at night. Night climbing is a particular branch of buildering which has been practiced for many years in a variety of locations, especially at the Universities of Oxford and Cambridge, England. Night climbing, as distinct from buildering, is performed mainly by undergraduates under cover of darkness. The term "night climbing" has replaced the older term "roof climbing". The philosophy behind night climbing has undergone great change during the 21st century, with urban disciplines such as parkour having a heavy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plunger
A plunger, force cup, plumber's friend or plumber's helper is a tool used to clear blockages in drains and pipes. It consists of a rubber suction cup attached to a stick (''shaft'') usually made of wood or plastic. A different bellows-like design also exists, usually constructed of plastic. Use For the common plunger, the cup is pushed down against the drain opening, either pressing hard into the drain to force air in, or pushing down until the rubber cup is flattened, and is then pulled out, creating a vacuum to pull blockage material upward and dislodge waste or other material. Shape and function The cup of a kitchen plunger looks like a rubber ball cut in half with a flared edge, while the toilet plunger's cup looks more like a distorted bowl, tapered on one half, with a large opening on the bottom. A plunger is much more effective with water in the pipe, as water does not compress and thus transmits more of the applied force than does air. When a plunger alone is in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
