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Ground Freezing
Ground freezing is a construction technique used in circumstances where soil needs to be stabilized so it will not collapse next to excavations, or to prevent contaminants spilled into soil from being leached away. Ground freezing has been used for at least one hundred years. Pipes are run through the soil to be frozen, and then refrigerants are run through the pipes, freezing the soil. Frozen soil can be as hard as concrete. Soil contaminated with radioactive elements that leaked from Japan's Fukushima Daiichi nuclear power plant was contained through ground freezing. A project in Boston known as the Big Dig used ground freezing during some of its tunneling, to allow its wide tunnels to be built under or through soil that supported existing infrastructure that would have been difficult or expensive to support using more traditional excavation methods. Some ground freezing projects use common salt brine as the refrigerant, but other projects benefit from using more exotic ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Freezing System In Operation While Commuter Trains Run Through The Big Dig
Ground may refer to: Geology * Land, the surface of the Earth not covered by water * Soil, a mixture of clay, sand and organic matter present on the surface of the Earth Electricity * Ground (electricity), the reference point in an electrical circuit from which voltages are measured * Earthing system, part of an electrical installation that connects with the Earth's conductive surface * Ground and neutral, closely related terms Law * Ground (often grounds), in law, a rational motive or basis for a belief, conviction, or action taken, such as a legal action or argument: * Grounds for divorce, regulations specifying the circumstances under which a person will be granted a divorce Music * ''Ground'' (album), the second album by the Nels Cline Trio * "Ground" (song), one of the songs in the debut album of the Filipino rock band Rivermaya * Ground bass, in music, a bass part that continually repeats, while the melody and harmony over it change * '' The Ground'', a 2005 album by N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross Section Of A Ground Freezing Pipe As Used In The Big Dig
A cross is a geometrical figure consisting of two intersecting lines or bars, usually perpendicular to each other. The lines usually run vertically and horizontally. A cross of oblique lines, in the shape of the Latin letter X, is termed a saltire in heraldic terminology. The cross has been widely recognized as a symbol of Christianity from an early period.''Christianity: an introduction'' by Alister E. McGrath 2006 pages 321-323 However, the use of the cross as a religious symbol predates Christianity; in the ancient times it was a pagan religious symbol throughout Europe and western Asia. The effigy of a man hanging on a cross was set up in the fields to protect the crops. It often appeared in conjunction with the female-genital circle or oval, to signify the sacred marriage, as in Egyptian amule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fukushima Daiichi Nuclear Power Plant
The is a disabled nuclear power plant located on a site in the towns of Ōkuma and Futaba in Fukushima Prefecture, Japan. The plant suffered major damage from the magnitude 9.0 earthquake and tsunami that hit Japan on March 11, 2011. The chain of events caused radiation leaks and permanently damaged several of its American-designed reactors, making them impossible to restart. By political decision, the remaining reactors were not restarted. First commissioned in 1971, the plant consists of six American-designed boiling water reactors. These light water reactors drove electrical generators with a combined power of 4.7 GWe, making Fukushima Daiichi one of the 15 largest nuclear power stations in the world. Fukushima was the first nuclear plant to be designed, constructed, and run in conjunction with General Electric and Tokyo Electric Power Company (TEPCO). The March 2011 disaster disabled the reactor cooling systems, leading to releases of radioactivity and tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston
Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- most populous city in the country. The city boundaries encompass an area of about and a population of 675,647 as of 2020. It is the seat of Suffolk County (although the county government was disbanded on July 1, 1999). The city is the economic and cultural anchor of a substantially larger metropolitan area known as Greater Boston, a metropolitan statistical area (MSA) home to a census-estimated 4.8 million people in 2016 and ranking as the tenth-largest MSA in the country. A broader combined statistical area (CSA), generally corresponding to the commuting area and including Providence, Rhode Island, is home to approximately 8.2 million people, making it the sixth most populous in the United States. Boston is one of the oldest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Dig
The Central Artery/Tunnel Project (CA/T Project), commonly known as the Big Dig, was a megaproject in Boston that rerouted the Central Artery of Interstate 93 (I-93), the chief highway through the heart of the city, into the 1.5-mile (2.4 km) tunnel named the Thomas P. O'Neill Jr. Tunnel. The project also included the construction of the Ted Williams Tunnel (extending I-90 to Logan International Airport), the Leonard P. Zakim Bunker Hill Memorial Bridge over the Charles River, and the Rose Kennedy Greenway in the space vacated by the previous I-93 elevated roadway. Initially, the plan was also to include a rail connection between Boston's two major train terminals. Planning began in 1982; the construction work was carried out between 1991 and 2006; and the project concluded on December 31, 2007, when the partnership between the program manager and the Massachusetts Turnpike Authority ended. The Big Dig was the most expensive highway project in the United States, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt Brine
Brine is a high-concentration solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of solutions used for brining foods) up to about 26% (a typical saturated solution, depending on temperature). Brine forms naturally due to evaporation of ground saline water but it is also generated in the mining of sodium chloride. Brine is used for food processing and cooking (pickling and brining), for de-icing of roads and other structures, and in a number of technological processes. It is also a by-product of many industrial processes, such as desalination, so it requires wastewater treatment for proper disposal or further utilization ( fresh water recovery). In nature Brines are produced in multiple ways in nature. Modification of seawater via evaporation results in the concentration of salts in the residual fluid, a characteristic geologic deposit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Nitrogen
Liquid nitrogen—LN2—is nitrogen in a liquid state at low temperature. Liquid nitrogen has a boiling point of about . It is produced industrially by fractional distillation of liquid air. It is a colorless, low viscosity liquid that is widely used as a coolant. Physical properties The diatomic character of the N2 molecule is retained after liquefaction. The weak van der Waals interaction between the N2 molecules results in little interatomic interaction, manifested in its very low boiling point. The temperature of liquid nitrogen can readily be reduced to its freezing point by placing it in a vacuum chamber pumped by a vacuum pump. Liquid nitrogen's efficiency as a coolant is limited by the fact that it boils immediately on contact with a warmer object, enveloping the object in an insulating layer of nitrogen gas bubbles. This effect, known as the Leidenfrost effect, occurs when any liquid comes in contact with a surface which is significantly hotter than its boil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pykrete
Pykrete is a frozen ice composite, originally made of approximately 14% sawdust or some other form of wood pulp (such as paper) and 86% ice by weight (6 to 1 by weight). During World War II, Geoffrey Pyke proposed it as a candidate material for a supersized aircraft carrier for the British Royal Navy. Pykrete features unusual properties, including a relatively slow melting rate due to its low thermal conductivity, as well as a vastly improved strength and toughness compared to ordinary ice. These physical properties can make the material comparable to concrete, as long as the material is kept frozen. Pykrete is slightly more difficult to form than concrete, as it expands during the freezing process. However, it can be repaired and maintained using seawater as a raw material. The mixture can be moulded into any shape and frozen, and it will be tough and durable, as long as it is kept at or below freezing temperature. Resistance to gradual creep or sagging is improved by loweri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Linde Group
Linde plc is a global multinational chemical company founded in Germany and, since 2018, domiciled in Ireland and headquartered in the United Kingdom. Linde is the world's largest industrial gas company by market share and revenue. It serves customers in the healthcare, petroleum refining, manufacturing, food, beverage carbonation, fiber-optics, steel making, aerospace, material handling equipment (MHE), chemicals, electronics and water treatment industries. The company's primary business is the manufacturing and distribution of atmospheric gases, including oxygen, nitrogen, argon, rare gases, and process gases, including carbon dioxide, helium, hydrogen, ammonia, electronic gases, specialty gases, and acetylene. The company was formed by the 2018 merger of Linde AG of Germany (founded in 1879) and Praxair (founded in 1907 as Linde Air Products Company) of the United States. The resulting holding company was incorporated in Ireland, with principal executive offices in Guildfor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Department Of Transport
The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the President of the United States and is a member of the president's Cabinet. The department's mission is "to develop and coordinate policies that will provide an efficient and economical national transportation system, with due regard for need, the environment, and the national defense." History Prior to the creation of the Department of Transportation, its functions were administered by the under secretary of commerce for transportation. In 1965, Najeeb Halaby, administrator of the Federal Aviation Agency (predecessor to the Federal Aviation Administration, FAA), suggested to President Lyndon B. Johnson that transportation be elevated to a cabinet-level post, and that the FAA be folded into the DOT. It was established by Congress in the Department of Transportatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
