A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were used for industrial power prior to electrical grids. Now they are used for electric power generation. Water turbines are mostly found in dams to generate power from water kinetic energy. Water wheels have been used for hundreds of years for industrial power and their main shortcoming is size, which limits the flow rate and head that can be harnessed. The migration from water wheels to modern turbines took about one hundred years, development occurred during the Industrial revolution, using scientific principles and methods. They made use of new materials and manufacturing methods developed at the time. The word turbine was introduced by the French engineer Claude Burdin in the early 19th century and is derived from the Greek word τύρβη for whirling or a vortex. The main difference between early water turbines and water wheels is a component of the water which passes energy to a spinning rotor.
This additional component of motion allowed the turbine to be smaller than a wheel of the same power. They could process more water by spinning faster and could harness much greater heads, the earliest known water turbines date to the Roman Empire. Two helix-turbine mill sites of almost identical design were found at Chemtou and Testour, modern-day Tunisia, the horizontal water wheel with angled blades was installed at the bottom of a water-filled, circular shaft. The water from the mill-race entered the pit tangentially, creating a water column which made the fully submerged wheel act like a true turbine. Fausto Veranzio in his book Machinae Novae described a vertical axis mill with a similar to that of a Francis turbine. Johann Segner developed a water turbine in the mid-18th century in Kingdom of Hungary. It had a horizontal axis and was a precursor to modern water turbines and it is a very simple machine that is still produced today for use in small hydro sites. Segner worked with Euler on some of the mathematical theories of turbine design.
In the 18th century, a Dr. Barker invented a similar reaction hydraulic turbine that became popular as a lecture-hall demonstration
Buffalo, New York
Buffalo is a city in western New York state and the county seat of Erie County, on the eastern shores of Lake Erie at the head of the Niagara River. As of 2014, Buffalo is New York states 2nd-most populous city after New York City, the metropolitan area has a population of 1.13 million. After an economic downturn in the half of the 20th century, Buffalos economy has transitioned to sectors that include financial services, biomedical engineering. Residents of Buffalo are called Buffalonians, the citys nicknames include The Queen City, The Nickel City and The City of Good Neighbors. The city of Buffalo received its name from a creek called Buffalo Creek. British military engineer Captain John Montresor made reference to Buffalo Creek in his journal of 1764, there are several theories regarding how Buffalo Creek received its name. In 1804, as principal agent opening the area for the Holland Land Company, Joseph Ellicott, designed a radial street and grid system that branches out from downtown like bicycle spokes similar to the street system he used in the nations capital.
Although Ellicott named the settlement New Amsterdam, the name did not catch on, during the War of 1812, on December 30,1813, Buffalo was burned by British forces. The George Coit House 1818 and Samuel Schenck House 1823 are currently the oldest houses within the limits of the City of Buffalo, on October 26,1825, the Erie Canal was completed with Buffalo a port-of-call for settlers heading westward. At the time, the population was about 2,400, the Erie Canal brought about a surge in population and commerce, which led Buffalo to incorporate as a city in 1832. In 1845, construction began on the Macedonia Baptist Church, an important meeting place for the abolitionist movement, Buffalo was a terminus point of the Underground Railroad with many fugitive slaves crossing the Niagara River to Fort Erie, Ontario in search of freedom. During the 1840s, Buffalos port continued to develop, both passenger and commercial traffic expanded with some 93,000 passengers heading west from the port of Buffalo.
Grain and commercial goods shipments led to repeated expansion of the harbor, in 1843, the worlds first steam-powered grain elevator was constructed by local merchant Joseph Dart and engineer Robert Dunbar. Darts Elevator enabled faster unloading of lake freighters along with the transshipment of grain in bulk from barges, canal boats, by 1850, the citys population was 81,000. At the dawn of the 20th century, local mills were among the first to benefit from hydroelectric power generated by the Niagara River, the city got the nickname City of Light at this time due to the widespread electric lighting. It was part of the revolution, hosting the brass era car builders Pierce Arrow. President William McKinley was shot and mortally wounded by an anarchist at the Pan-American Exposition in Buffalo on September 6,1901, McKinley died in the city eight days and Theodore Roosevelt was sworn in at the Wilcox Mansion as the 26th President of the United States. The Great Depression of 1929–39 saw severe unemployment, especially working class men
Cabo de Hornos is a Chilean commune located in the south of Tierra del Fuego archipelago, in Antártica Province, Magallanes Region. The municipality of Cabo de Hornos, located in the town of Puerto Williams and it is named for Cape Horn. According to the 2002 census of the National Statistics Institute, Cabo de Hornos spans an area of 15,853.7 km2 and has 2,262 inhabitants, of these,1,952 lived in urban areas and 310 in rural areas. The population grew by 24. 7% between the 1992 and 2002 censuses, as a commune, Cabo de Hornos is a third-level administrative division of Chile administered by a municipal council, headed by an alcalde who is directly elected every four years. The 2016-2020 alcalde is Patricio Fernández, the commune is represented in the Senate by Carlos Bianchi Chelech and Carolina Goic as part of the 19th senatorial constituency. Murray Channel Cabo de Hornos commune,2006 Official website of the Municipality of Cabo de Hornos Official website of Puerto Williams Gobierno Regional Magallanes y Antártica Chilena Official website Cape Horn Biosphere Reserve
Elihu Thomson was an English-born American engineer and inventor who was instrumental in the founding of major electrical companies in the United States, the United Kingdom and France. He was born in Manchester on March 29,1853, Thomson attended Central High School in Philadelphia and graduated in 1870. Thomson took a position at Central, and in 1876, at the age of twenty-three. In 1880, he left Central to pursue research in the field of electrical engineering. With Edwin J. Houston, a teacher and colleague of Thomsons at Central High School. Notable inventions created by Thomson during this period include a system, an automatically regulated three-coil dynamo, a magnetic lightning arrester. In 1892 the Thomson-Houston Electric Company merged with the Edison General Electric Company to become the General Electric Company, the historian Thomas P. Hughes writes that Thomson displayed methodological characteristics in the workshop and the laboratory as inventor and in the business world as entrepreneur.
He chose to solve problems in the expanding field of electric light. Thomsons name is commemorated by the British Thomson-Houston Company. Thomson was notable both for his emphasis on models and for the focus with which he pursued his research. Between 1880 and 1885, Thomson averaged twenty-one patent applications annually, at the Lynn GE plant, he worked with Edwin Rice and Sanford Moss and Charles Steinmetz. After being asked to become a director of GE, Thomson rejected the offer preferring continued research to management, Thomson was president of the organization from 1889-90. Near the end of his life, Thomsons second wife Clarissa Hovey Thomson is reported to have said that she had to carry a basket with her to all of Thomsons awards. In 1889 he was decorated by the French Government for his electrical inventions and he received the honorary degree of A. M. from Yale. Tufts College in 1892 gave him the degree of Ph. D. and he was a founding member, as well as the second president, of the International Electrotechnical Commission.
He served as acting president of MIT from 1920-1923, overcoming his distaste for management accepted this role during a critical period for the university when it could not otherwise find a president. Thomson died at his estate in Swampscott, the Elihu Thomson House in Swampscott was designated a U. S. National Historic Landmark in 1976 and serves as Swampscotts town hall. Thomson held more than 700 patents, Thomson used his patents to bolster his company, Thomson-Houston Company, General Electric
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. It is a term that has inherited from the earlier technology of mill ponds. Penstocks for hydroelectric installations are normally equipped with a gate system, flow is regulated by turbine operation and is nil when turbines are not in service. Penstocks, particularly used in polluted water systems, need to be maintained by hot water washing, manual cleaning, antifouling coatings. The term is used in irrigation dams to refer to the channels leading to. Penstocks are used in mine tailings dam construction, the penstock is usually situated fairly close to the center of the tailings dam and built up using penstock rings. These control the level, letting the slimes settle out of the water. This water is piped under the tailings dam back to the plant via a penstock pipeline. Similar structures which are not enclosed are head races or leats, penstocks are commonly used in water management systems such as surface water drainage and foul water sewers.
Penstocks provide a means of isolation of flows, penstocks are incorporated into the surface water management systems of many landfill sites. Attenuation lagoons are constructed in order to store water, limiting the discharge from the site to pre-development rate. Penstocks are installed at the outfall from the lagoon so that in the event that the surface water becomes contaminated the penstock may be closed. This will have the effect of isolating the site from the watercourse, penstock cross-sections for the Grand Coulee Dam U. S. Department of Energy Hydropower Basics
Tennessee marble achieved such popularity in the late-19th century that Knoxville, the stones primary finishing and distribution center, became known as The Marble City. While Tennessee marble is not true marble, its crystalline nature lends it a resemblance to marble. The stone occurs in belts of Ordovician-period rocks known as the Holston Formation, and is quarried primarily in Knox, Loudon, while pink is the most well-known Tennessee marble color, the stone occurs in gray, dark brown, and variegated shades. The use of Tennessee marble declined after World War II, when building materials became widely available. There are currently six active Tennessee marble quarries, all operated by the Tennessee Marble Company. The stone has most recently used in the floor of the United States Capitol Visitor Center. Tennessee marble is found in the Appalachian Ridge-and-Valley Province, a series of alternating elongate ridges, the Holston Formation, in which Tennessee marble is found, occurs in a series of belts that follow the natural folds and faults of the Ridges-and-Valleys.
While these belts can be up to 75 miles long, they are more than a few miles wide. A seventh belt, the Galbraith in Hawkins County, is considered an extension of the Black Oak, the Luttrell belt, the westernmost of the Holston Formation belts, stretches along Copper Ridge from Beaver Creek in Fountain City northeast to Galbraith Springs in Hawkins County. The Black Oak belt stretches along Black Oak Ridge from Monroe County to the Corryton area in north Knox County, the Concord belt, one of the most heavily quarried, stretches from Sweetwater through Knox County to Strawberry Plains. The Knoxville belt, stretches from southeast of Sweetwater to Ruggles Ferry in Knox. The Bays Mountain belt is found along the end of Bays Mountain in south Knox County. The French Broad belt is a u-shaped belt found at the confluence of the French Broad, while true marble is metamorphic, Tennessee marble is sedimentary, and is therefore classified as limestone. Tennessee marble was formed from the accumulation of bryozoan and other primordial marine lifeforms 460 million years ago, even when polished, Tennessee marble retains a fossiliferous texture, with bryozoan and crinoid fossils being among the most commonly found.
A noticeable feature of Tennessee marble is the presence of jagged horizontal gray or black lines, known as crowfeet by quarrymen, these form from residual insoluble materials left over from the natural limestone dissolution processes. The most well-known shades of Tennessee marble are pink and cedar, but it is found in blue and cream shades. Along with its colors, builders preferred the stone for its durability, the ease with which it is polished. Tennessee marble is converted into lime, and mid-20th century lime companies occasionally erected kilns near defunct quarries for this purpose
A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. A varying current in one coil of the transformer produces a magnetic field. Power can be transferred between the two coils through the field, without a metallic connection between the two circuits. Faradays law of induction discovered in 1831 described this effect, Transformers are used to increase or decrease the alternating voltages in electric power applications. A wide range of designs is encountered in electronic and electric power applications. Transformers range in size from RF transformers less than a centimeter in volume to units interconnecting the power grid weighing hundreds of tons. For simplification or approximation purposes, it is common to analyze the transformer as an ideal transformer model as presented in the two images. An ideal transformer is a theoretical, linear transformer that is lossless and perfectly coupled, perfect coupling implies infinitely high core magnetic permeability and winding inductances and zero net magnetomotive force. A varying current in the primary winding creates a varying magnetic flux in the transformer core.
This varying magnetic field at the secondary winding induces a varying EMF or voltage in the secondary winding due to electromagnetic induction. The primary and secondary windings are wrapped around a core of high magnetic permeability so that all of the magnetic flux passes through both the primary and secondary windings. With a voltage source connected to the winding and load impedance connected to the secondary winding. The primary EMF is sometimes termed counter EMF and this is in accordance with Lenzs law, which states that induction of EMF always opposes development of any such change in magnetic field. The transformer winding voltage ratio is shown to be directly proportional to the winding turns ratio according to eq. common usage having evolved over time from turn ratio to turns ratio. However, some use the inverse definition. The ideal transformer model assumes that all flux generated by the primary winding links all the turns of winding, including itself. In practice, some flux traverses paths that take it outside the windings, Such flux is termed leakage flux, and results in leakage inductance in series with the mutually coupled transformer windings.
Leakage flux results in energy being alternately stored in and discharged from the fields with each cycle of the power supply
Frequency is the number of occurrences of a repeating event per unit time. It is referred to as frequency, which emphasizes the contrast to spatial frequency. The period is the duration of time of one cycle in a repeating event, for example, if a newborn babys heart beats at a frequency of 120 times a minute, its period—the time interval between beats—is half a second. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as vibrations, audio signals, radio waves. For cyclical processes, such as rotation, oscillations, or waves, in physics and engineering disciplines, such as optics and radio, frequency is usually denoted by a Latin letter f or by the Greek letter ν or ν. For a simple motion, the relation between the frequency and the period T is given by f =1 T. The SI unit of frequency is the hertz, named after the German physicist Heinrich Hertz, a previous name for this unit was cycles per second. The SI unit for period is the second, a traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated r/min or rpm.
As a matter of convenience and slower waves, such as ocean surface waves and fast waves, like audio and radio, are usually described by their frequency instead of period. Spatial frequency is analogous to temporal frequency, but the axis is replaced by one or more spatial displacement axes. Y = sin = sin d θ d x = k Wavenumber, in the case of more than one spatial dimension, wavenumber is a vector quantity. For periodic waves in nondispersive media, frequency has a relationship to the wavelength. Even in dispersive media, the frequency f of a wave is equal to the phase velocity v of the wave divided by the wavelength λ of the wave. In the special case of electromagnetic waves moving through a vacuum, v = c, where c is the speed of light in a vacuum, and this expression becomes, f = c λ. When waves from a monochrome source travel from one medium to another, their remains the same—only their wavelength. For example, if 71 events occur within 15 seconds the frequency is, the latter method introduces a random error into the count of between zero and one count, so on average half a count.
This is called gating error and causes an error in the calculated frequency of Δf = 1/, or a fractional error of Δf / f = 1/ where Tm is the timing interval. This error decreases with frequency, so it is a problem at low frequencies where the number of counts N is small, an older method of measuring the frequency of rotating or vibrating objects is to use a stroboscope
National Register of Historic Places
The National Register of Historic Places is the United States federal governments official list of districts, buildings and objects deemed worthy of preservation. The passage of the National Historic Preservation Act in 1966 established the National Register, of the more than one million properties on the National Register,80,000 are listed individually. The remainder are contributing resources within historic districts, each year approximately 30,000 properties are added to the National Register as part of districts or by individual listings. For most of its history the National Register has been administered by the National Park Service and its goals are to help property owners and interest groups, such as the National Trust for Historic Preservation, coordinate and protect historic sites in the United States. While National Register listings are mostly symbolic, their recognition of significance provides some financial incentive to owners of listed properties, protection of the property is not guaranteed.
During the nomination process, the property is evaluated in terms of the four criteria for inclusion on the National Register of Historic Places, the application of those criteria has been the subject of criticism by academics of history and preservation, as well as the public and politicians. Occasionally, historic sites outside the proper, but associated with the United States are listed. Properties can be nominated in a variety of forms, including individual properties, historic districts, the Register categorizes general listings into one of five types of properties, site, building, or object. National Register Historic Districts are defined geographical areas consisting of contributing and non-contributing properties, some properties are added automatically to the National Register when they become administered by the National Park Service. These include National Historic Landmarks, National Historic Sites, National Historical Parks, National Military Parks/Battlefields, National Memorials, on October 15,1966, the Historic Preservation Act created the National Register of Historic Places and the corresponding State Historic Preservation Offices.
Initially, the National Register consisted of the National Historic Landmarks designated before the Registers creation, approval of the act, which was amended in 1980 and 1992, represented the first time the United States had a broad-based historic preservation policy. To administer the newly created National Register of Historic Places, the National Park Service of the U. S. Department of the Interior, hartzog, Jr. established an administrative division named the Office of Archeology and Historic Preservation. Hartzog charged OAHP with creating the National Register program mandated by the 1966 law, ernest Connally was the Offices first director. Within OAHP new divisions were created to deal with the National Register, the first official Keeper of the Register was William J. Murtagh, an architectural historian. During the Registers earliest years in the late 1960s and early 1970s, organization was lax and SHPOs were small and underfunded. A few years in 1979, the NPS history programs affiliated with both the U. S.
National Parks system and the National Register were categorized formally into two Assistant Directorates. Established were the Assistant Directorate for Archeology and Historic Preservation and the Assistant Directorate for Park Historic Preservation, from 1978 until 1981, the main agency for the National Register was the Heritage Conservation and Recreation Service of the United States Department of the Interior. In February 1983, the two assistant directorates were merged to promote efficiency and recognize the interdependency of their programs, jerry L. Rogers was selected to direct this newly merged associate directorate
The American River is a 120-mile-long river in California that runs from the Sierra Nevada mountain range to its confluence with the Sacramento River in the Sacramento Valley. Via the Sacramento River, it is part of the San Francisco Bay watershed, the river still has high quality water, and it is the main source of drinking water for Sacramento. This river is dammed extensively for irrigation, flood control, the American River watershed supports Mediterranean and montane ecosystems, and it is the home of a diverse array of fish and wildlife. They utilized the vast amount of resources of the American River for shelter, baskets, the Nisenan called the river Kum Mayo, meaning roundhouse river. Spanish explorer Gabriel Moraga named the river Rio de las Llagas when he passed through the area in the early 1800s, during the 1820s, Jedediah Smith led an expedition to the American River with the goal of finding a safe route across the Sierra Nevada. In Smiths honor the Spanish settlers and Native Americans named the river Rio de los Americanos, during this time, Alta California was part of New Spain, however in 1822, Mexico gained its independence from Spain and took control of California.
In the 1830s fur trappers of the Hudsons Bay Company visited the area to trap beaver and otter, during one of these expeditions, smallpox or malaria were accidentally introduced to the local Native Americans, who had no natural immunity to Old World diseases. Some accounts suggest as much as 70 percent of the population was wiped out. The surviving natives became hostile to European settlers and traders for quite some time, in 1839, German immigrant John Sutter established the New Helvetia settlement on the American River, near the present-day location of central Sacramento. In 1848, following the Mexican-American War, California was ceded to the United States in the Treaty of Guadalupe Hidalgo, just weeks later, James Marshall, an employee of Sutter, discovered gold on the South Fork, starting the California Gold Rush. Although miners looking for gold worked all three forks of the American River, the South Fork held the richest deposits, however, as the easily accessible placer gold was played out, large companies used hydraulic mining to access gold buried deeper in the soil.
Unfortunately, this large and extensive mining practice washed away entire mountainsides and heavily polluted all the waterways, during the Great Flood of 1862 the American River flooded massively, putting much of Sacramento under water for three months. Newly elected Governor Leland Stanford had to travel to his inauguration by rowboat, shortly after, a significant contributor to the flood damage was the debris washed down by hydraulic mining, which had choked the river channel and reduced its capacity to drain floodwaters. In response, the city of Sacramento undertook a project to raise its streets. Many of original sidewalks and the first floors of buildings remain as subterranean spaces underneath todays streets and this status provides state and national recognition to protect the rivers outstanding scenic and wildlife, historic and recreational values. The American River is fed by its North and South forks, which are located in El Dorado County, Placer County, the rivers three forks originate in the Tahoe and Eldorado National Forests.
The North and Middle Forks join near Auburn, and continue downstream as the North Fork, the North and South Forks join in Folsom Lake. All three forks are known for their verdant canyons, forested ridges, massive rock formations, backcountry winter adventuring among snowy peaks, there are various fish species that live within the American River such as Chinook Salmon and Steelhead Trout
National Historic Landmark
A National Historic Landmark is a building, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Of over 85,000 places listed on the countrys National Register of Historic Places, a National Historic Landmark District may include contributing properties that are buildings, sites or objects, and it may include non-contributing properties. Contributing properties may or may not be separately listed, prior to 1935, efforts to preserve cultural heritage of national importance were made by piecemeal efforts of the United States Congress. The first National Historic Site designation was made for the Salem Maritime National Historic Site on March 17,1938. In 1960, the National Park Service took on the administration of the data gathered under this legislation. Because listings often triggered local preservation laws, legislation in 1980 amended the procedures to require owner agreement to the designations. On October 9,1960,92 properties were announced as designated NHLs by Secretary of the Interior Fred A.
Seaton, more than 2,500 NHLs have been designated. Most, but not all, are in the United States, there are NHLs in all 50 states and the District of Columbia. Three states account for nearly 25 percent of the nations NHLs, three cities within these states all separately have more NHLs than 40 of the 50 states. In fact, New York City alone has more NHLs than all but five states, California, Massachusetts, there are 74 NHLs in the District of Columbia. Some NHLs are in U. S. commonwealths and territories, associated states, and foreign states. There are 15 in Puerto Rico, the Virgin Islands, and other U. S. commonwealths and territories,5 in U. S. -associated states such as Micronesia, over 100 ships or shipwrecks have been designated as NHLs. About half of the National Historic Landmarks are privately owned, the National Historic Landmarks Program relies on suggestions for new designations from the National Park Service, which assists in maintaining the landmarks. A friends group of owners and managers, the National Historic Landmark Stewards Association, works to preserve, protect, if not already listed on the National Register of Historic Places, an NHL is automatically added to the Register upon designation.
About three percent of Register listings are NHLs, american Water Landmark List of U. S
Folsom is a city in Sacramento County, United States. Folsom is most commonly known for its infamous Folsom Prison, the population was 72,203 at the 2010 census. Folsom is part of the Sacramento−Arden-Arcade−Roseville Metropolitan Statistical Area, though few amassed a great deal of wealth, the city prospered due to Joseph Folsoms lobbying to get a railway to connect the town with Sacramento. Joseph died in 1855, and Granite City was renamed to Folsom in his honor, the railway was abandoned in the 1980s but opened up as the terminus of the Gold Line of Sacramento Regional Transit Districts light rail service in 2005. A few former gold-rush era towns are located within city limits of Folsom, including Prairie City, Salmon Falls, Folsom hosted a significant Chinese American community when it was first incorporated, but arsonists burned Folsoms Chinatown in March 1886, driving Chinese Americans out of town. The establishment of Folsom Prison came in 1880, when the Livermore family made an agreement with the state to land for the prison in exchange for prison labor.
They planned to build a dam from the American River for a sawmill. At the time it was opened, it had the longest overhead run of electricity in the country, Folsom Dam was built in 1956, providing much-needed flood control and water rights for the Sacramento Valley. The creation of this dam created one of the most popular lakes in Northern California, the dam is located on the southwest corner of the lake. The lake is an estimated 4.8 miles from Granite Bay to the most southern point of Folsom Lake, Folsom is home to Folsom Lake College, Folsom Dam, Folsom Lake, Folsom High School, Vista del Lago High School and a historic district. Folsom is home to the largest private employer in the Sacramento area, Folsom is located in the foothills of the Sierra Nevada. Folsoms climate is characterized by long, dry summers and cool, the 2010 United States Census reported that Folsom had a population of 72,203. The population density was 2,971.2 people per square mile. The racial makeup of Folsom was 53,627 White,4,140 African American,427 Native American,9,000 Asian,173 Pacific Islander,1,818 from other races, hispanic or Latino of any race were 8,064 persons.
The Census reported that 65,243 people lived in households,188 lived in non-institutionalized group quarters, there were 1,150 unmarried opposite-sex partnerships, and 137 same-sex married couples or partnerships. 5,788 households were made up of individuals and 1,930 had someone living alone who was 65 years of age or older, the average household size was 2.61. There were 17,600 families, the family size was 3.13. The median age was 37.6 years, for every 100 females there were 114.1 males