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Fire Hydrant
A fire hydrant, fireplug, firecock (archaic), hydrant riser or Johnny Pump is a connection point by which firefighters can tap into a water supply. It is a component of active fire protection. Underground fire hydrants have been used in Europe and Asia since at least the 18th century. Above-ground pillar-type hydrants are a 19th-century invention. Operation The user (most likely a fire department) attaches a hose to the fire hydrant, then opens a valve on the hydrant to provide a powerful flow of water, on the order of ; this pressure varies according to region and depends on various factors (including the size and location of the attached water main). This user can attach this hose to a fire engine, which can use a powerful pump to boost the water pressure and possibly split it into multiple streams. One may connect the hose with a threaded connection, instantaneous " quick connector" or a Storz connector. If a fire hydrant is opened or closed too quickly, a water hammer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downtown Charlottesville Fire Hydrant
''Downtown'' is a term primarily used in American English, American and Canadian English to refer to a city's sometimes Commerce, commercial, Culture, cultural and often the historical, Politics, political, and geographic heart. It is often synonymous with its central business district (CBD). It may also be a center for shopping and entertainment. Downtowns typically contain a small percentage of a city's employment but are concentrated in services, including high-end services (office or white-collar workers, white-collar jobs). Sometimes, smaller downtowns include lower population densities and nearby lower incomes than suburbs. It is often distinguished as a hub of public transit and culture. History Origins The ''Oxford English Dictionarys first citation for "down town" or "downtown" dates to 1770, in reference to the center of Boston. Some have posited that the term "downtown" was coined in New York City, where it was in use by the 1830s to refer to the original settlement, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WHTM
WHTM-TV (channel 27) is a television station licensed to Harrisburg, Pennsylvania, United States, serving the Susquehanna Valley region as an affiliate of ABC. Owned by Nexstar Media Group, the station maintains studios on North 6th Street in Harrisburg (although with a Hoffman Street address). Through a channel sharing agreement with Red Lion–licensed religious independent station WLYH (channel 49), the two stations transmit using WHTM-TV's spectrum from an antenna on a ridge north of I-81 along the Cumberland–Perry county line. History The station first signed on the air on June 19, 1953, as WTPA (standing for "Television Pennsylvania"), operating as an NBC affiliate. WTPA was founded by the Newhouse family, whose media holdings eventually became Advance Publications, and was operated alongside Harrisburg's two major newspapers, ''The Patriot'' and ''The Evening News'' (since merged as '' The Patriot-News''). The following year, it switched affiliations to ABC. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City
New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive with a respective county. The city is the geographical and demographic center of both the Northeast megalopolis and the New York metropolitan area, the largest metropolitan area in the United States by both population and urban area. New York is a global center of finance and commerce, culture, technology, entertainment and media, academics, and scientific output, the arts and fashion, and, as home to the headquarters of the United Nations, international diplomacy. With an estimated population in 2024 of 8,478,072 distributed over , the city is the most densely populated major city in the United States. New York City has more than double the population of Los Angeles, the nation's second-most populous city. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engineering is the field dedicated to controlling and preventing corrosion. In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen, hydrogen, or hydroxide. Rusting, the formation of red-orange iron oxides, is a well-known example of electrochemical corrosion. This type of corrosion typically produces oxides or salts of the original metal and results in a distinctive coloration. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term "degradation" is more common. Corrosion degrades the useful properties of materials and structures including mechanical strength, appearance, and permeability to liquids and ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Face Shield
A face shield, an item of personal protective equipment, aims to protect the wearer's entire face (or part of it) from hazards such as Projectile, flying objects and road debris, chemical splashes (in laboratory, laboratories or in Industry (economics), industry), or potentially Infection, infectious materials (in Medicine, medical and laboratory environments). Applications Medical In Medicine, medical applications the device is used to protect a medical professional during a procedure that might expose them to blood or other potentially infectious fluids or aerosols. An example is the use of a Pocket mask, CPR mask while performing Mouth-to-mouth resuscitation, rescue breathing or Cardiopulmonary resuscitation, CPR. Another example is the use of face shields to reduce the likelihood of inhaling potentially infectious bioaerosols. Police and military File:AssaultTraining2016-18.jpg, Russian Engineer Troops, Russian combat engineer with a 6B47 helmet and ballistic f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmet
A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman's helmet in the United Kingdom) without protective function are sometimes worn. Soldiers wear combat helmets, often made from Kevlar or other lightweight synthetic fibers. The word ''helmet'' is derived from ''helm'', an Old English word for a protective head covering. Helmets are used for most sports (e.g., jockeys, American football, ice hockey, cricket, baseball, skiing, hurling and rock climbing); dangerous work activities such as construction, mining, riot police, military aviation, and in transportation (e.g. motorcycle helmets and bicycle helmets). Since the 1990s, most helmets are made from resin or plastic, which may be reinforced with fibers such as aramids. Designs Some British gamekeepers during the 18th and 19th centuries wore helmets made of straw bound together wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glove
A glove is a garment covering the hand, with separate sheaths or openings for each finger including the thumb. Gloves protect and comfort hands against cold or heat, damage by friction, abrasion or chemicals, and disease; or in turn to provide a guard for what a bare hand should not touch. Gloves are made of materials including cloth, knitted or felted wool, leather, rubber, latex, neoprene, silk, and (in mail) metal. Gloves of kevlar protect the wearer from cuts. Gloves and gauntlets are integral components of pressure suits and spacesuits. Latex, nitrile rubber or vinyl disposable gloves are often worn by health care professionals as hygiene and contamination protection measures. Police officers often wear them to work in crime scenes to prevent destroying evidence in the scene. Many criminals wear gloves to avoid leaving fingerprints, which makes the crime investigation more difficult. However, the gloves themselves can leave prints that are just as unique as human fingerp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Protective Equipment
Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemical, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. ''Protective clothing'' is applied to traditional categories of clothing, and ''protective gear'' applies to items such as pads, guards, shields, or masks, and others. PPE suits can be similar in appearance to a cleanroom suit. The purpose of personal protective equipment is to reduce employee exposure to hazards when engineering controls and administrative controls are not feasible or effective to reduce these risks to acceptable levels. PPE is needed when there are hazards present. PPE has the serious limitation that it d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butterfly Valve
A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing mechanism is a disk that rotates. Principle of operation Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they cost less than other valve designs, and are lighter weight so they need less support. The disc is positioned in the center of the pipe. A rod passes through the disc to an actuator on the outside of the valve. Rotating the actuator turns the disc either parallel or perpendicular to the flow. Unlike a ball valve, the disc is always present within the flow, so it induces a pressure drop, even when open. A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gate Valve
A gate valve, also known as a sluice valve, is a valve that opens by lifting a barrier (gate) out of the path of the fluid. Gate valves require very little space along the pipe axis and hardly restrict the flow of fluid when the gate is fully opened. The gate faces can be parallel but are most commonly wedge-shaped (in order to be able to apply pressure on the sealing surface). Typical use Gate valves are used to shut off the flow of liquids rather than for flow regulation, which is frequently done with a globe valve. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low Drag (physics), flow resistance. The size of the open flow path generally varies in a nonlinear manner as the gate is moved. This means that the flow rate does not change evenly with stem travel. Depending on the construction, a partially open gate can vibrate from the fluid flow. Gate valves are mostly used with larger pipe diameters (from 2" to the largest pipelines) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrodynamic Scour
lang=en, upright=1.3, Mechanism of formation, alt=sketch Hydrodynamic scour is the removal of sediment such as silt, sand and gravel from around the base of obstructions to the flow in the sea, rivers and canals. Scour, caused by fast flowing water, can carve out scour holes, compromising the integrity of a structure. It is an interaction between the hydrodynamics and the geotechnical properties of the substrate. It is a notable cause of bridge failure and a problem with most marine structures supported by the seabed in areas of significant tidal and ocean current. It can also affect biological ecosystems and heritage assets. Mechanism Any obstruction within flowing water will produce changes in velocity within the water column. The flow changes that occur in the vicinity of the substrate may cause differential movement in the bed materials near the obstruction. The magnitude of these changes varies with stream velocity, feature shape and substrate character. Generally the str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
