Water vapor, water vapour or aqueous vapor, is the gaseous phase of water. It is one state of water within the hydrosphere, water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapor is invisible, under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is lighter than air and triggers convection currents that can lead to clouds, use of water vapor, as steam, has been important to humans for cooking and as a major component in energy production and transport systems since the industrial revolution. Likewise the detection of water vapor would indicate a similar distribution in other planetary systems. Water vapor is significant in that it can be evidence supporting the presence of extraterrestrial liquid water in the case of some planetary mass objects. Whenever a water molecule leaves a surface and diffuses into a surrounding gas, each individual water molecule which transitions between a more associated and a less associated state does so through the absorption or release of kinetic energy.
The aggregate measurement of kinetic energy transfer is defined as thermal energy. Liquid water that becomes water vapor takes a parcel of heat with it, the amount of water vapor in the air determines how fast each molecule will return to the surface. When a net evaporation occurs, the body of water will undergo a net cooling directly related to the loss of water, in the US, the National Weather Service measures the actual rate of evaporation from a standardized pan open water surface outdoors, at various locations nationwide. Others do likewise around the world, the US data is collected and compiled into an annual evaporation map. The measurements range from under 30 to over 120 inches per year, formulas can be used for calculating the rate of evaporation from a water surface such as a swimming pool. In some countries, the evaporation rate far exceeds the precipitation rate, evaporative cooling is restricted by atmospheric conditions. Humidity is the amount of vapor in the air. The vapor content of air is measured with devices known as hygrometers, the measurements are usually expressed as specific humidity or percent relative humidity.
This condition is referred to as complete saturation. Humidity ranges from 0 gram per cubic metre in dry air to 30 grams per cubic metre when the vapor is saturated at 30 °C, another form of evaporation is sublimation, by which water molecules become gaseous directly, leaving the surface of ice without first becoming liquid water. Sublimation accounts for the slow disappearance of ice and snow at temperatures too low to cause melting
Syngas, or synthesis gas, is a fuel gas mixture consisting primarily of hydrogen, carbon monoxide, and very often some carbon dioxide. The name comes from its use as intermediates in creating synthetic natural gas, syngas is usually a product of gasification and the main application is electricity generation. Syngas is combustible and often used as a fuel of internal combustion engines and it has less than half the energy density of natural gas. Syngas can be produced from many sources, including gas, biomass, or virtually any hydrocarbon feedstock, by reaction with steam. Syngas is a crucial resource for production of hydrogen, methanol. Syngas is used as an intermediate in producing synthetic petroleum for use as a fuel or lubricant via the Fischer–Tropsch process and previously the Mobil methanol to gasoline process. Production methods include steam reforming of natural gas or liquid hydrocarbons to produce hydrogen, the gasification of coal, the chemical composition of syngas varies based on the raw materials and the processes.
Syngas produced by coal gasification generally is a mixture of 30 to 60% carbon monoxide,25 to 30% hydrogen,5 to 15% carbon dioxide and it contains lesser amount of other gases. The main reaction that produces syngas, steam reforming, is a reaction with 206 kJ/mol methane needed for conversion. The first reaction, between incandescent coke and steam, is endothermic, producing carbon monoxide, and hydrogen H2. When the coke bed has cooled to a temperature at which the reaction can no longer proceed. The overall reaction is exothermic, forming producer gas, steam can be re-injected, air etc. to give an endless series of cycles until the coke is finally consumed. Producer gas has a lower energy value, relative to water gas. Pure oxygen can be substituted for air to avoid the dilution effect and this is primarily done by pressure swing adsorption, amine scrubbing, and membrane reactors. Conversion of biomass to syngas is typically low-yield, the University of Minnesota developed a metal catalyst that reduces the biomass reaction time by up to a factor of 100.
The catalyst can be operated at atmospheric pressure and reduces char, the entire process is autothermic and therefore heating is not required. CO2 can be split into CO and combined with hydrogen to form syngas and this technique was alleged to have been used during the Cold war in Russian nuclear submarines to allow them to get rid of CO2 gas without leaving a bubble trail. Publicly available journals published during the Cold War indicate that American submarines used conventional chemical scrubbers to remove CO2, documents released after the sinking of the Kursk, a Cold War era Oscar-class submarine, indicate that potassium superoxide scrubbers were used to remove carbon dioxide on that vessel
A gear or cogwheel is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part to transmit torque. Geared devices can change the speed and direction of a power source, Gears almost always produce a change in torque, creating a mechanical advantage, through their gear ratio, and thus may be considered a simple machine. The teeth on the two meshing gears all have the same shape, two or more meshing gears, working in a sequence, are called a gear train or a transmission. A gear can mesh with a linear toothed part, called a rack, the gears in a transmission are analogous to the wheels in a crossed, belt pulley system. An advantage of gears is that the teeth of a gear prevent slippage, in transmissions with multiple gear ratios—such as bicycles and cars—the term gear as in first gear refers to a gear ratio rather than an actual physical gear. The term describes similar devices, even when the ratio is continuous rather than discrete, or when the device does not actually contain gears.
Early examples of gears date from the 4th century BC in China, examples of further development include, Ma Jun used gears as part of a south-pointing chariot. The Antikythera mechanism is an example of an early and intricate geared device. Its time of construction is now estimated between 150 and 100 BC, the water-powered grain-mill, the water-powered saw mill, fulling mill, and other applications of watermill often used gears. The first mechanical clocks were built in AD725, the 1386 Salisbury cathedral clock may be the worlds oldest working mechanical clock. The definite ratio that teeth give gears provides an advantage over other drives in precision machines such as watches that depend upon an exact velocity ratio, an external gear is one with the teeth formed on the outer surface of a cylinder or cone. Conversely, a gear is one with the teeth formed on the inner surface of a cylinder or cone. For bevel gears, a gear is one with the pitch angle exceeding 90 degrees. Internal gears do not cause output shaft direction reversal, spur gears or straight-cut gears are the simplest type of gear.
They consist of a cylinder or disk with teeth projecting radially, though the teeth are not straight-sided, the edge of each tooth is straight and aligned parallel to the axis of rotation. These gears mesh together correctly only if fitted to parallel shafts, No axial thrust is created by the tooth loads. Spur gears are excellent at moderate speeds but tend to be noisy at high speeds, helical or dry fixed gears offer a refinement over spur gears. The leading edges of the teeth are not parallel to the axis of rotation, since the gear is curved, this angling makes the tooth shape a segment of a helix
Saint John, New Brunswick
Saint John is a city on the Fundy coast in New Brunswick, Canada. In 2016, the city is the second largest in New Brunswick and has a population of 67,575 over an area of 315.82 square kilometres, Saint John is the oldest incorporated city in Canada. During the reign of Britains George III, the municipality was created by charter in 1785. The Saint John metropolitan area covers a area of 3,362.95 square kilometres across the Caledonia Highlands. Samuel de Champlain landed at Saint John Harbour on June 24,1604 and is where the Saint John River gets its name. S, in 1785, Saint John became the first incorporated city in what would become Canada. Over the next century, waves of Irish immigration, namely during the Great Famine via Partridge Island, would change the citys demographics. The Mikmaq ventured into the territory and named the area Měnagwĕs, samuel de Champlain landed at Saint John Harbour in 1604, but the area was in English hands by the end of the Seven Years War. After being incorporated as a city in 1785 with an influx of Loyalists from the Boston States and immigrants from Ireland, in 1851 the city cemented itself internationally when the Marco Polo, built from a Saint John yard, became the fastest in the world.
However, the city would experience much struggle with its success. From 1840 to 1860 sectarian violence was rampant in Saint John resulting in some of the worst urban riots in Canadian history. The city experienced an outbreak in 1854 with the death over 1,500 people, as well as a great fire in 1877 that destroyed 40% of the city. 1785, First quarantine station in North America, Partridge Island, in the early 19th century, it greeted sick and dying Irish immigrants arriving with inhospitable conditions. 1820, The first chartered bank in Canada, the Bank of New Brunswick, Canadas oldest publicly funded high school, Saint John High School 1838, The first penny newspaper in the Empire, the tri-weekly Saint John News, was established. 1842, Canadas first public museum, originally known as the Gesner Museum, named after its Nova Scotian founder Abraham Gesner, the museum is now known as the New Brunswick Museum. 1849, Canada’s first labour union, the Laborer’s Benevolent Association that was formed when Saint John’s longshoremen banded together to lobby for regular pay and a shorter workday.
One of their first resolutions was to apply to the city council for permission to erect the bell,1854, The automated steam foghorn was invented by Robert Foulis. 1870, Canadas first Y. W. C. A. was established,1870, First Knights of Pythias in British Empire. 1872, Monitor top railroad cars in the world invented by James Ferguson, the original model is in the New Brunswick Museum in Saint John
Slovenia, officially the Republic of Slovenia, is a nation state in southern Central Europe, located at the crossroads of main European cultural and trade routes. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and it covers 20,273 square kilometers and has a population of 2.06 million. It is a republic and a member of the United Nations, European Union. The capital and largest city is Ljubljana, the Dinaric Alps and the Pannonian Plain meet on the territory of Slovenia. The country, marked by a significant biological diversity, is one of the most water-rich in Europe, with a river network, a rich aquifer system. Over half of the territory is covered by forest, the human settlement of Slovenia is dispersed and uneven. Slovenia has historically been the crossroads of South Slavic, Romance, although the population is not homogeneous, the majority is Slovene. South Slavic language Slovene is the language throughout the country.
Slovenia is a largely secularized country, but its culture and identity have been influenced by Catholicism as well as Lutheranism. The economy of Slovenia is small and export-oriented and has strongly influenced by international conditions. It has been hurt by the Eurozone crisis, started in the late 2000s. The main economic field is services, followed by industry and construction, the current territory of Slovenia was part of many different state formations, including the Roman Empire and the Holy Roman Empire, followed by the Habsburg Monarchy. In October 1918, the Slovenes exercised self-determination for the first time by co-founding the State of Slovenes, Croats, in December 1918, they merged with the Kingdom of Serbia into the Kingdom of Serbs and Slovenes. During World War II, Slovenia was occupied and annexed by Germany and Hungary, with a tiny area transferred to the Independent State of Croatia, in June 1991, after the introduction of multi-party representative democracy, Slovenia split from Yugoslavia and became an independent country.
Present-day Slovenia has been inhabited since prehistoric times, and there is evidence of habitation from around 250,000 years ago. A pierced cave bear bone, dating from 43100 ±700 BP, in the 1920s and 1930s, artifacts belonging to the Cro-Magnon such as pierced bones, bone points, and needle were found by archaeologist Srečko Brodar in Potok Cave. It shows that wooden wheels appeared almost simultaneously in Mesopotamia and Europe, in the transition period between the Bronze age to the Iron age, the Urnfield culture flourished. Archaeological remains dating from the Hallstatt period have been found, particularly in southeastern Slovenia, among them a number of situlas in Novo Mesto, in the Iron Age, present-day Slovenia was inhabited by Illyrian and Celtic tribes until the 1st century BC
A gate valve, known as a sluice valve, is a valve which opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The gate faces can be parallel, but are most commonly wedge-shaped, gate valves are primarily used to permit or prevent the flow of liquids, but typical gate valves shouldnt be used for regulating flow, unless they are specifically designed for that purpose. Because of their ability to cut through liquids, gate valves are used in the petroleum industry. For extremely thick fluids, a specialty valve often known as a gate valve is used to cut through the liquid. On opening the valve, the flow path is enlarged in a highly nonlinear manner with respect to percent of opening. This means that flow rate does not change evenly with stem travel, also, a partially open gate tends to vibrate from the fluid flow. Most of the change occurs near shutoff with a relatively high fluid velocity causing gate and seat wear. Typical gate valves are designed to be opened or closed.
When fully open, the gate valve has no obstruction in the flow path. Gate valves are actuated by a stem which connects the actuator to the gate. They are characterised as having either a rising or a nonrising stem, rising stems are fixed to the gate and rise and lower together as the valve is operated, providing a visual indication of valve position. The actuator takes the form of a nut which is rotated around the stem to move it. Nonrising stem valves are fixed to, and rotate with, the actuator and they may have a pointer threaded onto the upper end of the stem to indicate valve position, since the gates motion is concealed inside the valve. Nonrising stems are used underground or where space is limited. Bonnets provide leakproof closure for the valve body, gate valves may have a screw-in, union, or bolted bonnet. Screw-in bonnet is the simplest, offering a durable, pressure-tight seal, union bonnet is suitable for applications requiring frequent inspection and cleaning. It gives the added strength.
Bolted bonnet is used for larger valves and higher pressure applications, another type of bonnet construction in a gate valve is pressure seal bonnet
The British Isles are a group of islands off the north-western coast of continental Europe that consist of the islands of Great Britain and over six thousand smaller isles. Situated in the North Atlantic, the islands have an area of approximately 315,159 km2. Two sovereign states are located on the islands and the United Kingdom of Great Britain, the oldest rocks in the group are in the north west of Scotland and North Wales and are 2,700 million years old. During the Silurian period the north-western regions collided with the south-east, the topography of the islands is modest in scale by global standards. Ben Nevis rises to an elevation of only 1,344 metres, and Lough Neagh, the climate is temperate marine, with mild winters and warm summers. The North Atlantic Drift brings significant moisture and raises temperatures 11 °C above the average for the latitude. This led to a landscape which was dominated by temperate rainforest. The region was re-inhabited after the last glacial period of Quaternary glaciation, which became an island by 12,000 BC, was not inhabited until after 8000 BC.
Great Britain became an island by 5600 BC, Hiberni and Britons tribes, all speaking Insular Celtic, inhabited the islands at the beginning of the 1st millennium AD. Much of Brittonic-controlled Britain was conquered by the Roman Empire from AD43, the first Anglo-Saxons arrived as Roman power waned in the 5th century and eventually dominated the bulk of what is now England. Viking invasions began in the 9th century, followed by permanent settlements. Most of Ireland seceded from the United Kingdom after the Irish War of Independence, the term British Isles is controversial in Ireland, where there are objections to its usage due to the association of the word British with Ireland. The Government of Ireland does not recognise or use the term, as a result and Ireland is used as an alternative description, and Atlantic Archipelago has had limited use among a minority in academia, while British Isles is still commonly employed. Within them, they are sometimes referred to as these islands. The earliest known references to the islands as a group appeared in the writings of sea-farers from the ancient Greek colony of Massalia.
The original records have been lost, writings, e. g. Avienuss Ora maritima, in the 1st century BC, Diodorus Siculus has Prettanikē nēsos, the British Island, and Prettanoi, the Britons. Strabo used Βρεττανική, and Marcian of Heraclea, in his Periplus maris exteri, historians today, though not in absolute agreement, largely agree that these Greek and Latin names were probably drawn from native Celtic-language names for the archipelago. Along these lines, the inhabitants of the islands were called the Πρεττανοί, the shift from the P of Pretannia to the B of Britannia by the Romans occurred during the time of Julius Caesar
Tap water is water supplied to a tap. Its uses include drinking, washing and the flushing of toilets, Tap water became common in many regions during the 20th century, and is now lacking mainly among people in poverty, especially in developing countries. Tap water is often assumed to be drinking water, especially in developed countries. Usually it is potable, although water quality problems are not rare, household water purification methods such as water filters, boiling, or distillation can be used when tap waters potability is doubted. The application of technologies involved in providing water to homes, businesses. Publicly available treated water has historically been associated with increases in life expectancy. Water-borne diseases are vastly reduced by proper sewage and fresh water availability, specific chemical compounds are often taken out of tap water during the treatment process to adjust the pH or remove contaminants, and chlorine may be added to kill biological toxins. Local geological conditions affecting groundwater are determining factors for the presence of metal ions.
Tap water remains susceptible to biological or chemical contamination, in the event of contamination deemed dangerous to public health, government officials typically issue an advisory regarding water consumption. In the case of contamination, residents are usually advised to boil their water before consumption or to use bottled water as an alternative. In the case of contamination, residents may be advised to refrain from consuming tap water entirely until the matter is resolved. In many areas a compound of fluoride is added to tap water in an effort to improve health among the public. In some communities fluoridation remains a controversial issue and this supply may come from several possible sources. Municipal water supply Water wells Processed water from creeks, rivers, rainwater, domestic water systems have been evolving since people first located their homes near a running water supply, such as a stream or river. The water flow allowed sending waste water away from the residences, modern indoor plumbing delivers clean, potable water to each service point in the distribution system.
It is important that the water not be contaminated by the waste water side of the process system. Historically, this contamination of drinking water has been the largest killer of humans, Tap water can sometimes appear cloudy, often mistaken for mineral impurities in the water. It is usually caused by air coming out of solution due to change in temperature or pressure
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure, the word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll. The simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid flow in one direction and this is called a check valve, as it prevents or checks the flow in one direction. Modern control valves may regulate pressure or flow downstream and operate on sophisticated automation systems, even aerosols have a tiny valve built in. Valves are used in the military and transport sectors, valves may be operated manually, either by a handle, pedal or wheel. Valves may be automatic, driven by changes in pressure and these changes may act upon a diaphragm or a piston which in turn activates the valve, examples of this type of valve found commonly are safety valves fitted to hot water systems or boilers.
More complex control systems using valves requiring automatic control based on an external input require an actuator, an actuator will stroke the valve depending on its input and set-up, allowing the valve to be positioned accurately, and allowing control over a variety of requirements. Valves vary widely in form and application, sizes typically range from 0.1 mm to 60 cm. Special valves can have a diameter exceeding 5 meters, valve costs range from simple inexpensive disposable valves to specialized valves which cost thousands of US dollars per inch of the diameter of the valve. Disposable valves may be found in household items including mini-pump dispensers. Valves are quite diverse and may be classified into a number of basic types, valves may be classified by how they are actuated, Hydraulic Pneumatic Manual Solenoid valve Motor The main parts of the most usual type of valve are the body and the bonnet. These two parts form the casing that holds the fluid going through the valve, the valves body is the outer casing of most or all of the valve that contains the internal parts or trim.
The bonnet is the part of the encasing through which the stem passes, the bonnet typically screws into or is bolted to the valve body. Valve bodies are usually metallic or plastic, bronze, cast iron, alloy steels and stainless steels are very common. Seawater applications, like plants, often use duplex valves, as well as super duplex valves, due to their corrosion resistant properties. Alloy 20 valves are used in sulphuric acid plants, whilst monel valves are used in hydrofluoric acid plants. Hastelloy valves are used in high temperature applications, such as nuclear plants
A beer tap is a valve, specifically a tap, for controlling the release of beer. While in other contexts, depending on location, a tap may be a faucet, valve or spigot and this may be because the word was originally coined for the wooden valve in traditional barrels. Beer served from a tap is known as draught beer. There are many different types of beer or keg taps, there are many styles of beer taps. Beer supplied in kegs is served with the aid of external pressure from a cylinder of carbon dioxide which forces the beer out of the keg, at the end of this tube is a valve built into a fixture on the bar. This is the tap and opening it with a small lever causes beer, pushed by the gas from the cylinder. One disadvantage of this system is that it produces a head which must be left to subside before more beer can be added to the glass. Some manufacturers have tried to address this problem by producing a device allows the beer to be poured from the bottom up. Sometimes, beer kegs designed to be connected to the system are instead used on their own.
In this case, a self-contained portable tap is required that allows beer to be served straight from the keg, because the keg system uses pressure to force the beer up and out of the keg, these taps must have a means of supplying it. The typical picnic tap uses a pump to push air into the keg. Portable taps with small CO2 cylinders are available, beers brewed and served by traditional methods, typically cask ale, do not use artificial gas. Taps for cask beer are simple on-off valves that are hammered into the end of the cask, when beer is served directly from the cask, as at beer festivals and some pubs, it simply flows out of the tap and into the glass. When the cask is stored in the cellar and served from the bar, as in most pubs, the line is screwed onto the tap. The taps used are the same, and in beer-line setups the first pint is often poured from the cask as for gravity, for tasting, cask beer taps can be brass, stainless steel and wood. In Scotland, cask ale was served through a tall fount.
These appear similar to keg taps rendered from brass but the beer was drawn from the barrel via air pressure generated by an engine rather than by a pressurised artificial gas. The Aitken fount variety is still in use in several Edinburgh pubs, typical tap handles are 9-13 tall, but can range from very short to novelty lengths
Parasitic drag is drag that results when an object is moved through a fluid medium. In the case of aerodynamic drag, the medium is the atmosphere. Parasitic drag is a combination of form drag, skin friction drag, the other components of total drag, induced drag, wave drag, and ram drag, are separate types of drag, and are not components of parasitic drag. Parasitic drag does not result from the induction of lift on the body, in flight, induced drag results from the lift force that must produced so that the craft can maintain level flight. Induced drag is greater at lower speeds where a high angle of attack is required, as speed increases, the induced drag decreases, but parasitic drag increases because the fluid is striking the object with greater force, and is moving across the objects surfaces at higher speed. As speed continues to increase into the transonic and supersonic regimes, each of these drag components changes in proportion to the others based on speed. The combined overall drag curve therefore shows a minimum at some airspeed, pilots will use this speed to maximize the gliding range in case of an engine failure.
However, to maximize the gliding endurance, the speed would have to be at the point of minimum power. At the point of minimum drag, CD, o is equal to CD, at the point of minimum power, CD, o is equal to one third times CD, i. Form drag follows the equation, meaning that it increases with velocity. Form drag depends on the section of the body. A prudent choice of body profile is essential for a low drag coefficient, streamlines should be continuous, and separation of the boundary layer with its attendant vortices should be avoided. Profile drag is usually defined as the sum of form drag, the term is often used synonymously with form drag. Interference drag results when airflow around one part of an object must occupy the space as the airflow around another part. This velocity increase is present at all airspeeds, but becomes more important in the transonic range when the resulting velocity becomes sonic. Interference drag plays a role throughout the aircraft and its detrimental effect is always kept in mind by designers.
Ideally, the distributions on the intersecting bodies should complement each other’s pressure distribution. If one body locally displays a negative coefficient, the intersecting body should have a positive pressure coefficient
Traditionally, a wooden keg is made by a cooper and used to transport items such as nails, and a variety of liquids. More recently, a keg is often constructed of aluminum or steel and it is commonly used to store and serve beer. Other alcoholic or non-alcoholic drinks, carbonated or non-carbonated, may be housed in a keg as well, such liquids are generally kept under pressure. Beer kegs are made of steel, or less commonly. A keg has an opening on one end, called a bung. A tube called a spear extends from the opening to the other end, There is a self-closing valve that is opened by the coupling fitting which is attached when the keg is tapped. There is an opening at the top of the spear that allows gas to drive the beer out of the keg, the coupling fitting has one or two valves that control the flow of beer out of and gas into the keg. The keg must be in the position, that is. Kegs can be contrasted to casks, which have two or more openings and no spear, most major breweries now use internally speared kegs.
Historically a beer barrel was a size of 50 gallons, as opposed to a wine barrel at 32 gallons. Over the years barrel sizes have evolved and breweries throughout the world use different sized containers, even when the content capacity of two kegs are equal—e. g. Metricized to 50 liters—the keg shape and keg tap system may differ greatly, most U. S. brewers sell beer in 1⁄2 barrels of 15.5 gallons, 1⁄4 barrels of 7.75 gallons, and 1⁄6 barrels of 5.17 gallons. Since keg sizes are not standardized, the keg cannot be used as a unit of measure for liquid volumes. This size standard varies from country to country and brewery to brewery with many using the metric system rather than U. S. gallons. A keg, or half-barrel is a 15.5 U. S. gallon vessel, a quarter-barrel has a volume of 7.75 U. S. gallons. Generally a keg is a smaller than a barrel, thus. In the U. S. the terms half-barrel and quarter-barrel are derived from the U. S. beer barrel, the German DIN 6647-1 and DIN 6647-2 have defined kegs in the sizes of 30 and 20 liters.
A newer Euro regulation defines 50,30,25 and 20 liters where the keg shape is usually thicker, in some areas it is common to refer to the size not in liters but in beers