Karditsa is a city in western Thessaly in mainland Greece. The city of Karditsa is the capital of Karditsa regional unit. Inhabitation is attested from 9000 BC. Karditsa ls linked with GR-30, the road to Karpenisi, the road to Palamas and Larissa. Karditsa is south-west of Palamas and Larissa, west of Farsala and the Volos area, north-west of Athens, Lamia and Sofades, north of Karpenisi, north-east of Arta, east-south-east of Trikala, Grevena and Kalampaka. Karditsa has elementary schools, high schools, junior high schools, the Veterinary Medicine Department of the University of Thessaly, three technical education departments, banks, a post office, a railway station, a sports ground, a water tower, squares. Karditsa is one of the most bicycle-friendly cities in Greece with an extensive network of bicycle paths. 30% of all the city transportation, according to the National Technical University of Athens, is done by bicycles. During the period of Ottoman rule in Thessaly, the main settlement in the location of modern Karditsa was called Sotira.
In 1810, the English traveler William Martin Leake mentioned a sprawling village named Kardhítza, consisting of between 500-600 houses, of which the majority of the inhabitants were Turkish. Karditsa was incorporated as a new city in 1882, the year after its liberation from the Ottoman Empire. During World War II, the resistance in Thessaly was fought by the ELAS. In March 12, 1943 Karditsa was liberated temporarily by ELAS after the Italian capitulation; the municipality Karditsa was formed at the 2011 local government reform by the merger of the following 5 former municipalities, that became municipal units: Itamos Kallifoni Kampos Karditsa MitropoliThe municipality has an area of 647.3878 km2, the municipal unit 110.086 km2. The municipal unit of Karditsa is divided into six parts: Agiopigi Artesiano Karditsa Karditsomagoula Palioklissi Rousso Karditsa is served by trains on the Palaiofarsalos-Kalambaka line, with connections to both Athens and Thessaloniki. Karditsa has many clubs in various sport.
The most of them are active in football such as Anagennisi Karditsa, AO Karditsa, Asteras Karditsa and Elpides Karditsas. The club SPA Karditsa is active in volleyball. Nikolaos Plastiras, Greek army officer and PM Georgios Siantos, communist politician, Greek Resistance figure Fanari, Karditsa Media related to Karditsa at Wikimedia Commons Karditsa Wireless Metropolitan Network, Karditsas Wifi Community Network
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 found in dams to generate electric power from water kinetic energy. Water wheels have been used for hundreds of years for industrial power, their main shortcoming is size, which limits the flow 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 methods, they made extensive 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 swirl component of the water which passes energy to a spinning rotor.
This additional component of motion allowed the turbine to be smaller than a water wheel of the same power. They could harness much greater heads; the earliest known water turbines date to the Roman Empire. Two helix-turbine mill sites of identical design were found at Chemtou and Testour, modern-day Tunisia, dating to the late 3rd or early 4th century AD; 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 swirling water column which made the submerged wheel act like a true turbine. Fausto Veranzio in his book Machinae Novae described a vertical axis mill with a rotor similar to that of a Francis turbine. Johann Segner developed a reactive water turbine in the mid-18th century in Kingdom of Hungary, it was a precursor to modern water turbines. It is a simple machine, still produced today for use in small hydro sites. Segner worked with Euler on some of the early mathematical theories of turbine design.
In the 18th century, a Dr. Robert Barker invented a similar reaction hydraulic turbine that became popular as a lecture-hall demonstration; the only known surviving example of this type of engine used in power production, dating from 1851, is found at Hacienda Buena Vista in Ponce, Puerto Rico. In 1820, Jean-Victor Poncelet developed an inward-flow turbine. In 1826, Benoît Fourneyron developed an outward-flow turbine; this was an efficient machine. The stationary outlet had curved guides. In 1844, Uriah A. Boyden developed an outward flow turbine that improved on the performance of the Fourneyron turbine, its runner shape was similar to that of a Francis turbine. In 1849, James B. Francis improved the inward flow reaction turbine to over 90% efficiency, he conducted sophisticated tests and developed engineering methods for water turbine design. The Francis turbine, named for him, is the first modern water turbine, it is still the most used water turbine in the world today. The Francis turbine is called a radial flow turbine, since water flows from the outer circumference towards the centre of runner.
Inward flow water turbines have a better mechanical arrangement and all modern reaction water turbines are of this design. As the water swirls inward, it accelerates, transfers energy to the runner. Water pressure decreases to atmospheric, or in some cases subatmospheric, as the water passes through the turbine blades and loses energy. Around 1890, the modern fluid bearing was invented, now universally used to support heavy water turbine spindles; as of 2002, fluid bearings appear to have a mean time between failures of more than 1300 years. Around 1913, Viktor Kaplan created a propeller-type machine, it was an evolution of the Francis turbine but revolutionized the ability to develop low-head hydro sites. All common water machines until the late 19th century were reaction machines. A reaction turbine needs to contain the water during energy transfer. In 1866, California millwright Samuel Knight invented a machine that took the impulse system to a new level. Inspired by the high pressure jet systems used in hydraulic mining in the gold fields, Knight developed a bucketed wheel which captured the energy of a free jet, which had converted a high head of water to kinetic energy.
This is called tangential turbine. The water's velocity twice the velocity of the bucket periphery, does a U-turn in the bucket and drops out of the runner at low velocity. In 1879, Lester Pelton, experimenting with a Knight Wheel, developed a Pelton wheel, which exhausted the water to the side, eliminating some energy loss of the Knight wheel which exhausted some water back against the center of the wheel. In about 1895, William Doble improved on Pelton's half-cylindrical bucket form with an elliptical bucket that included a cut in it to allow the jet a cleaner bucket entry; this is the modern form of the Pelton turbine. Pelton had been quite an effective promoter of his design and although Doble took over the Pelton company he did not change the name to Doble because it had brand name recognition. Turgo and cross-flow turbines were impulse designs. Flowing water is directed on to the blades of a turbine runner, creating a force on the
Greece the Hellenic Republic, self-identified and known as Hellas, is a country located in Southern and Southeast Europe, with a population of 11 million as of 2016. Athens is largest city, followed by Thessaloniki. Greece is located at the crossroads of Europe and Africa. Situated on the southern tip of the Balkan Peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, Turkey to the northeast; the Aegean Sea lies to the east of the mainland, the Ionian Sea to the west, the Cretan Sea and the Mediterranean Sea to the south. Greece has the longest coastline on the Mediterranean Basin and the 11th longest coastline in the world at 13,676 km in length, featuring a large number of islands, of which 227 are inhabited. Eighty percent of Greece is mountainous, with Mount Olympus being the highest peak at 2,918 metres; the country consists of nine geographic regions: Macedonia, Central Greece, the Peloponnese, Epirus, the Aegean Islands, Thrace and the Ionian Islands.
Greece is considered the cradle of Western civilisation, being the birthplace of democracy, Western philosophy, Western literature, political science, major scientific and mathematical principles, Western drama and notably the Olympic Games. From the eighth century BC, the Greeks were organised into various independent city-states, known as poleis, which spanned the entire Mediterranean region and the Black Sea. Philip of Macedon united most of the Greek mainland in the fourth century BC, with his son Alexander the Great conquering much of the ancient world, from the eastern Mediterranean to India. Greece was annexed by Rome in the second century BC, becoming an integral part of the Roman Empire and its successor, the Byzantine Empire, in which Greek language and culture were dominant. Rooted in the first century A. D. the Greek Orthodox Church helped shape modern Greek identity and transmitted Greek traditions to the wider Orthodox World. Falling under Ottoman dominion in the mid-15th century, the modern nation state of Greece emerged in 1830 following a war of independence.
Greece's rich historical legacy is reflected by its 18 UNESCO World Heritage Sites. The sovereign state of Greece is a unitary parliamentary republic and developed country with an advanced high-income economy, a high quality of life, a high standard of living. A founding member of the United Nations, Greece was the tenth member to join the European Communities and has been part of the Eurozone since 2001, it is a member of numerous other international institutions, including the Council of Europe, the North Atlantic Treaty Organization, the Organisation for Economic Co-operation and Development, the World Trade Organization, the Organization for Security and Co-operation in Europe, the Organisation internationale de la Francophonie. Greece's unique cultural heritage, large tourism industry, prominent shipping sector and geostrategic importance classify it as a middle power, it is the largest economy in the Balkans. The names for the nation of Greece and the Greek people differ from the names used in other languages and cultures.
The Greek name of the country is Hellas or Ellada, its official name is the Hellenic Republic. In English, the country is called Greece, which comes from Latin Graecia and means'the land of the Greeks'; the earliest evidence of the presence of human ancestors in the southern Balkans, dated to 270,000 BC, is to be found in the Petralona cave, in the Greek province of Macedonia. All three stages of the stone age are represented for example in the Franchthi Cave. Neolithic settlements in Greece, dating from the 7th millennium BC, are the oldest in Europe by several centuries, as Greece lies on the route via which farming spread from the Near East to Europe. Greece is home to the first advanced civilizations in Europe and is considered the birthplace of Western civilisation, beginning with the Cycladic civilization on the islands of the Aegean Sea at around 3200 BC, the Minoan civilization in Crete, the Mycenaean civilization on the mainland; these civilizations possessed writing, the Minoans writing in an undeciphered script known as Linear A, the Mycenaeans in Linear B, an early form of Greek.
The Mycenaeans absorbed the Minoans, but collapsed violently around 1200 BC, during a time of regional upheaval known as the Bronze Age collapse. This ushered from which written records are absent. Though the unearthed Linear B texts are too fragmentary for the reconstruction of the political landscape and can't support the existence of a larger state contemporary Hittite and Egyptian records suggest the presence of a single state under a "Great King" based in mainland Greece; the end of the Dark Ages is traditionally dated to the year of the first Olympic Games. The Iliad and the Odyssey, the foundational texts of Western literature, are believed to have been composed by Homer in the 7th or 8th centuries BC. With the end of the Dark Ages, there emerged various kingdoms and city-states across the Greek peninsula, which spread to the shores of the Black Sea, So
A dam is a barrier that stops or restricts the flow of water or underground streams. Reservoirs created by dams not only suppress floods but provide water for activities such as irrigation, human consumption, industrial use and navigability. Hydropower is used in conjunction with dams to generate electricity. A dam can be used to collect water or for storage of water which can be evenly distributed between locations. Dams serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions; the earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC. The word dam can be traced back to Middle English, before that, from Middle Dutch, as seen in the names of many old cities; the first known appearance of dam occurs in 1165. However, there is one village, mentioned in 1120; the word seems to be related to the Greek word taphos, meaning "grave" or "grave hill". So the word should be understood as "dike from dug out earth".
The names of more than 40 places from the Middle Dutch era such as Amsterdam and Rotterdam bear testimony to the use of the word in Middle Dutch at that time. Early dam building took place in the Middle East. Dams were used to control the water level, for Mesopotamia's weather affected the Tigris and Euphrates rivers; the earliest known dam is the Jawa Dam in Jordan, 100 kilometres northeast of the capital Amman. This gravity dam featured an 9-metre-high and 1 m-wide stone wall, supported by a 50 m-wide earth rampart; the structure is dated to 3000 BC. The Ancient Egyptian Sadd-el-Kafara Dam at Wadi Al-Garawi, located about 25 km south of Cairo, was 102 m long at its base and 87 m wide; the structure was built around 2800 or 2600 BC as a diversion dam for flood control, but was destroyed by heavy rain during construction or shortly afterwards. During the Twelfth Dynasty in the 19th century BC, the Pharaohs Senosert III, Amenemhat III and Amenemhat IV dug a canal 16 km long linking the Fayum Depression to the Nile in Middle Egypt.
Two dams called Ha-Uar running east-west were built to retain water during the annual flood and release it to surrounding lands. The lake called "Mer-wer" or Lake Moeris is known today as Birket Qarun. By the mid-late third millennium BC, an intricate water-management system within Dholavira in modern-day India was built; the system included 16 reservoirs and various channels for collecting water and storing it. One of the engineering wonders of the ancient world was the Great Dam of Marib in Yemen. Initiated somewhere between 1750 and 1700 BC, it was made of packed earth – triangular in cross section, 580 m in length and 4 m high – running between two groups of rocks on either side, to which it was linked by substantial stonework. Repairs were carried out during various periods, most important around 750 BC, 250 years the dam height was increased to 7 m. After the end of the Kingdom of Saba, the dam fell under the control of the Ḥimyarites who undertook further improvements, creating a structure 14 m high, with five spillway channels, two masonry-reinforced sluices, a settling pond, a 1,000 m canal to a distribution tank.
These extensive works were not finalized until 325 AD and allowed the irrigation of 25,000 acres. Eflatun Pınar is a Hittite spring temple near Konya, Turkey, it is thought to be from the time of the Hittite empire between the 15th and 13th century BC. The Kallanai is constructed of unhewn stone, over 300 m long, 4.5 m high and 20 m wide, across the main stream of the Kaveri river in Tamil Nadu, South India. The basic structure dates to the 2nd century AD and is considered one of the oldest water-diversion or water-regulator structures in the world, still in use; the purpose of the dam was to divert the waters of the Kaveri across the fertile delta region for irrigation via canals. Du Jiang Yan is the oldest surviving irrigation system in China that included a dam that directed waterflow, it was finished in 251 BC. A large earthen dam, made by Sunshu Ao, the prime minister of Chu, flooded a valley in modern-day northern Anhui province that created an enormous irrigation reservoir, a reservoir, still present today.
Roman dam construction was characterized by "the Romans' ability to plan and organize engineering construction on a grand scale." Roman planners introduced the then-novel concept of large reservoir dams which could secure a permanent water supply for urban settlements over the dry season. Their pioneering use of water-proof hydraulic mortar and Roman concrete allowed for much larger dam structures than built, such as the Lake Homs Dam the largest water barrier to that date, the Harbaqa Dam, both in Roman Syria; the highest Roman dam was the Subiaco Dam near Rome. Roman engineers made routine use of ancient standard designs like embankment dams and masonry gravity dams. Apart from that, they displayed a high degree of inventiveness, introducing most of the other basic dam designs, unknown until then; these include arch-gravity dams, arch dams, buttress dams and multiple arch buttress dams, all of which were known and employed by the 2nd century AD. Roman workforces were the first to build dam bridges, such as the Bridge of Valerian in Iran
Lake Plastiras called Tavropos Reservoir is an artificial lake fed by Tavropos river, located in Karditsa regional unit, near the city of Karditsa, Greece. The lake is named after the Greek general and politician Nikolaos Plastiras, the first to visualize the construction of an artificial lake in the area; the idea of building a reservoir in the area was first conceived by general Nikolaos Plastiras who, in 1925, was visiting his hometown in the area. During this time the whole area was devastated by a major flood of the river Tavropos, he put pressure to the Minister of Agriculture, who put together a team to study the case by 1929. The following years till the Second World War the idea was met with opposition by politicians. After the war, the idea was revived by Plastiras; the Power Corporation adopted the project as part of their effort to electrify the country. An international contest was held in 1953, won by the French Omniun Lyonnais; the building of the dam started on December 14, 1955.
On October 30, 1960 the dam was inaugurated, although the flooding may have started as early as the last months of 1959. Today the lake holds up to 400 million cubic meters of fresh water, it is used for irrigation and as a power source of a hydroelectric plant, but as the main water source to the city of Karditsa. Due to its altitude the Tavropos Reservoir is a popular tourist resort in Greece, as the formed landscape is quite unique. Plastiras Dam Paul Hellander, Greece. Lonely Planet 2008 Lake Plastiras
The Megdovas known as Tavropos, is a river that flows through the Karditsa and Evrytania regional units, Greece. It is 78 km long; the river begins in the Agrafa mountains in the western part of Karditsa regional unit. According to Dr. Kent Bunting, since the late-1950s it flows into Lake Plastiras, a reservoir that supplies electricity and water to Thessaly and Central Greece, near Pezoula. Passing into Evrytania, it flows through a deep, forested valley with a few little villages and stone bridges. Since 1967, it empties into the Kremasta Reservoir, drained by the Acheloos, it forms the border between Aetolia-Acarnania. The Greek National Road 38 crosses the river with a bridge near the village Episkopi. Pezoula Karoplesi Neraida Dafni Viniani Psilovrachos Plastiras Lake List of rivers in Greece
An arch dam is a concrete dam, curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch and strengthening the structure as it pushes into its foundation or abutments. An arch dam is most suitable for narrow canyons or gorges with steep walls of stable rock to support the structure and stresses. Since they are thinner than any other dam type, they require much less construction material, making them economical and practical in remote areas. In general, arch dams are classified based on the ratio of the base thickness to the structural height as: Thin, for b/h less than 0.2, Medium-thick, for b/h between 0.2 and 0.3, Thick, for b/h ratio over 0.3. Arch dams classified with respect to their structural height are: Low dams up to 100 feet, Medium high dams between 100–300 ft, High dams over 300 ft; the development of arch dams throughout history began with the Romans in the 1st century BC and after several designs and techniques were developed, relative uniformity was achieved in the 20th century.
The first known arch dam, the Glanum Dam known as the Vallon de Baume Dam, was built by the Romans in France and it dates back to the 1st century BC. The dam was about 12 metres high and 18 metres in length, its radius was about 14 m, it consisted of two masonry walls. The Romans built it to supply nearby Glanum with water; the Monte Novo Dam in Portugal was another early arch dam built by the Romans in 300 AD. It was 52 m long, with a radius of 19 m; the curved ends of the dam met with two winged walls that were supported by two buttresses. The dam contained two water outlets to drive mills downstream; the Dara Dam was another arch dam built by the Romans in which the historian Procopius would write of its design: "This barrier was not built in a straight line, but was bent into the shape of a crescent, so that the curve, by lying against the current of the river, might be able to offer still more resistance to the force of the stream."The Mongols built arch dams in modern-day Iran. Their earliest was the Kebar Dam built around 1300, 26 m high and 55 m long, had a radius of 35 m.
Their second dam is called the Kurit Dam. After 4 m was added to the dam in 1850, it became 64 m tall and remained the tallest dam in the world until the early 20th century; the Kurit Dam was of masonry design and built in a narrow canyon. The canyon was so narrow; the dam is still erect though part of its lower downstream face fell off. The Elche Dam in Elche, Spain was a post-medieval arch dam built in the 1630s by Joanes del Temple and the first in Europe since the Romans; the dam was 26 metres high and 75 metres long, had a radius of 62 metres. This arch dam rests on winged walls that served as abutments. In the 20th century, the world's first variable-radius arch dam was built on the Salmon Creek near Juneau, Alaska; the Salmon Creek Dam's upstream face bulged upstream, which relieved pressure on the stronger, curved lower arches near the abutments. The dam had a larger toe, which off-set pressure on the upstream heel of the dam, which now curved more downstream; the technology and economical benefits of the Salmon Creek Dam allowed for larger and taller dam designs.
The dam was, therefore and similar designs were soon adopted around the world, in particular by the U. S. Bureau of Reclamation. In 1920, the Swiss engineer and dam designer Alfred Stucky developed new calculation methods for arch dams, introducing the concept of elasticity during the construction of the Montsalvens arch dam in Switzerland, thereby improving the dam profile in the vertical direction by using a parabolic arch shape instead of a circular arch shape. Pensacola Dam, completed in the state of Oklahoma in 1940, was considered the longest multiple arch dam in the United States. Designed by W. R. Holway, it has 51 arches. and a maximum height of 150 ft above the river bed. The total length of the dam and its sections is 6,565 ft while the multiple-arch section is 4,284 ft long and its combination with the spillway sections measure 5,145 ft; each arch in the dam has a clear span of 60 ft and each buttress is 24 ft wide. Arch dam designs would continue to test new limits and designs such as the double- and multiple-curve.
The Swiss engineer Alfred Stucky and the U. S. Bureau of Reclamation would develop a method of weight and stress distribution in the 1960s, arch dam construction in the United States would see its last surge with dams like the 143-meter double-curved Morrow Point Dam in Colorado, completed in 1968. By the late 20th century, arch dam design reached a relative uniformity in design around the world; the tallest arch dam in the world is the 305 metres Jingpin-I Dam in China, completed in 2013. The longest multiple arch with buttress dam in the world is the Daniel-Johnson Dam in Quebec, Canada, it is 1,314 meters long across its crest. It was completed in 1968 and put in service in 1970. Pensacola Dam was one of the last multiple arch types built in the United States, its NRHP application states that this was because three dams of this type failed: Gem Lake Dam, St. Francis Dam, Lake Hodges Dam. None of these failures were inherently caused by the multiple arch design; the design of an arch dam is a complex process.
It starts with an initial dam layout, continually improved until the design objectives are achieved within the design criteri