DAMS Contents What is a dam Dam types Estonian dams What is a dam § A dam is a structure designed to hold back water in a lake or river. § Dams typically include gates that can be opened or closed to allow the needed amount of water to pass downstream or leave the lake. § Generally, a hydropower station is also constructed at or near the dam site to develop hydropower. § Dams are very huge structure and require huge money, manpower and time to construct. Dam types Embankment dams · Embankment dams are the most common type of dam in use today. · Materials used for embankment dams include natural soil or rock · The ability of an embankment dam to resist the reservoir water pressure is primarily a result of the mass weight,
released and flows through the turbines. there are many Advantages for hydropower. *The mayor advantage of hydroelectricity is eliminating the cost of fuel. You don't have to fear about the increasing cost of fossil fuels like oil and natural gas. *The second advantage is that hydroelectric plants last longer than fuel-fired plants. Some hydro plants have been operational about 100 years. *Operating labor costs are low as well because the plants are automated. *And Because the hydroelectric dams do not burn fossil fuels, they do not directly produce carbon dioxide. *The reservoirs can also provide facilities for water sports, and become tourist attractions themselves. In many countries farming fish in the reservoir is common. Also large dams can control floods. The reservoirs can also improve transport. on the other hand there are some Disadvantages *Hydroelectric projects can be disruptive to surrounding ecosystems both upstream and downstream. For
hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy. History Hydropower has been used since ancient times to grind flour and perform other tasks. In the mid1770s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique which described vertical and horizontalaxis hydraulic machines. Hydroelectric Dam Generating methods Conventional (dams) Pumpedstorage Runoftheriver Underground Advantages Economics CO2 emissions Other uses of the reservoir Disadvantages Ecosystem damage and loss of land Siltation Relocation Failure hazard Estonia hydroelectricity´s Kamari hüdroelektrijaam Tudulinna hüdroelektrijaam Linnamäe hüdroelektrijaam Largest The Three Gorges Dam is the largest operating hydroelectric power station, at 22,500 MW. Three Gorges Dam Video http://www.youtube.com/watch?v=rnPEtwQtmGQ
POEM The months. January brings the snow, Makes our feet and fingers glows. February brings the rains, Thaws the frozen lake again. March brings breezes sharp and chill, Shakes the dancing daffodil. April brings the primrose sweet, Scatters daisies at our feet. May brings flocks of pretty lambs, Sporting round their fleecy dams. June brings tulips, lilies, rose, Fills the children's hands with posies. Hot July brings thundershowers, Apricots, and gillyflowers. August brings the sheaves of corn; Then the harvest home is borne. Warm September brings the fruit; Sportsmen then begin to shoot. Brown October brings the pheasant, Then to gather nuts is pleasant. Dull November brings the blast-- Hark! the leaves are whirling fast. Cold December brings the sleet, Blazing fire, and Christmas treat. The Alphabet Song
DEPRECIATION Liis Kalma RP101 Wh at i s d ep reci ati on ? Reduction in value or the effective economic life of an asset arising from the: Passage of time Use or abuse Wear and tear Influence of the elements Stoppage of demand for use Wha t can be de pre ci at e d ? Tangible depreciable property: Livestock (purchased) Machinery Buildings and improvements, fences Dams, ponds, or terraces, etc Intangible depreciable property: Goodwill Computer software Copyrights, patents, etc What cannot be depreciated ? When depreciation begins & ends? Begins Ends When you "place the property When the cost of the item has in service". When it is ready and been recovered or when it is available for a specific use in the retired from service, whichever business happens first
they cover a mere 6% and experts estimate that the last remaining rainforests could be consumed in less than 40 years. · Vihmametsad katsid kunagi 14% maapinnast, praegu katavad nad ainult 6% ja eksperdid arvavad et viimased alles olevad vihmametsad nö. tarvitatakse ära vähema kui 40 aasta pärast. Causes of rainforest destruction Vihmametsa hävitus põhjused. · Logging · Agriculture · Fuelwood- küttepuud · Large Dams- suured tammid · Mining and industry- kaevandus ja tööstus. · Tourism turism. · Poverty and overpopulation vaesus ja ülerahvastatus. · Colonialism kolonialism. Why save it? · The rainforest is home to over · Vihmamets on koduks rohkem fifty percent of all plants and kui 50 % maa loomadele ja animals on earth. It is the taimedele. See on maa elav
Kõrgkvaliteetse talaseinaga VT 20K on ökonoomne võimalus õhemate lagede toestamiseks. Roni raketis SKS Single Sided Climbing System The modular forming system for single-face climbing applications With the PERI SKSF 240 and SKS 180 climbing systems, the loads from the fresh concrete pressure are transferred through the brackets by means of V-strongbacks and compression braces into the scaffold anchors. Typical applications for the SKSF 240 and SKS 180 are dams, locks, cooling towers, pier heads, tunnels, and bank vaults. SKSF 240: With the 2.40 m wide SKSF 240, the formwork is mounted on a carriage which can be retracted by 60 cm without the need of a crane. This means reinforcement work, assembly of scaffold anchors, and the installation and dismantling of box-outs is made much easier. SKS 180: The formwork is simply tilted backwards when striking takes place. The 1.80 m wide bracket
growing rapidly are known for their tolerance econo • shipbuilding • heavy industry • cotton, tobacco • Great Lakes • dams and • fishing, my • fishing • shipping lanes (plantations) Port (Chicago irrigation camping, • trade • drug manuf., • slavery aka the 3. projects hiking etc • communications • manufacturing largest city of • gambling • mining,
· Forbes said "no" money) to the wind sector is more than 200 times as great as those given to oil and gas sector. Oh and the wind has to blow. Hydropower Power to the Water · By using earth's · 90% energy water cycles and efficient compared running water used to natural gas threw mostly dams being 50% to provide energy. efficient. · Hydropower is · The only problem about 1/3 the cost is, you need water. of using fossil fuels and about 1/6 the cost of natural gas. Biofuels · Using natural I Love you Plants materials to turn into fuel or forms of combustible energy. · Which is mostly plants and plant products Cost Efficient? · A study done by OSU So much for the love....
into the vehicle. · Roof rack: a set of bars secured to the roof of a motor car.[1] It is used to carry bulky items such as luggage, bicycles, canoes, kayaks, skis, or various carriers and containers. · Spoiler: an automotive aerodynamic device whose intended design function is to 'spoil' unfavourable air movement across a body of a vehicle in motion, usually described as drag. Spoilers on the front of a vehicle are often called air dams, because in addition to directing air flow they also reduce the amount of air flowing underneath the vehicle which generally reduces aerodynamic lift and drag. Spoilers are often fitted to race and high-performance sports cars, although they have become common on passenger vehicles as well. Some spoilers are added to cars primarily for styling purposes and have either little aerodynamic benefit or even make the aerodynamics worse.
turbine that generates electricity. Nuclear power was used to generate 19.4% of all the country's electricity in 2007. Hydropower, the source for 5.8% of U.S. electricity generation in 2007, is a process in which flowing water is used to spin a turbine connected to a generator. There are two basic types of hydroelectric systems that produce electricity. In the first system, flowing water accumulates in reservoirs created by the use of dams. The water falls through a pipe called a penstock and applies pressure against the turbine blades to drive the generator to produce electricity. In the second system, called run-of-river, the force of the river current (rather than falling water) applies pressure to the turbine blades to produce electricity. Geothermal power comes from heat energy buried beneath the surface of the earth. In some areas of the country, enough heat rises close to the surface of the earth to heat
Structural evolution achieved by Roman engineers is manifest in aqueducts, dam construction, and highway bridges that relied on the development of concrete, and a growing awareness of its strength. The Romans mixed a cement, pozzolana, found near the Italian town of Pozzuoli (ancient Puteoli), with lime, sand, and water to form a mortar that did not disintegrate when exposed to water. It was used as a binder in piers and arch spandrels, and mass-formed in foundations. Coffer dams (temporary enclosures built in river beds to keep the water out while the foundations were established) were made by driving timber piles into the river bed, removing water from the area enclosed, and then excavating the soft ground inside. Despite the use of coffer dams, Roman bridge foundations typically were not deep enough to provide sufficient protection against scour. Most of the Roman bridges that survive are those built on solid rock such as the Pont du Gard aqueduct (c
The majority of the students eat margarine. Four students prefer butter, and another four eat neither. Conclusion It is noticeable that the eating habits of schoolleavers of Freedonian Secondary School are not very healthy. Moreover, there are no students who have both breakfast and school lunch, eat more than four slices of brown bread per day, and avoid fat. The debate about the best way to generate electricity is back on the agenda. The most common methods are by burning coal, building dams, or using nuclear power. However, many people think that nuclear power is dangerous, and when you consider the experience of Chernobyl in the Ukraine over 20 years ago, you can see why. Countries such as France, however, get about 80% of their electricity from nuclear power plants, and the pro-nuclear scientists argue that it is actually much clearer than burning fossil fuels, which contributes to global warming.
Other reasons that many want to use hydro energy is that it is cheaper than using other methods to convert energy to electricity. It is also reliable and can be used almost immediately when turned on to meet the demand for electricity. Therefore, one must weigh the pros and cons before deciding to use hydro energy to supply their demand for electricity. There are many forms of water energy: * Hydroelectric energy is a term usually reserved for large-scale hydroelectric dams. Examples are the Grand Coulee Dam in Washington State and the Akosombo Dam in Ghana. * Micro hydro systems are hydroelectric power installations that typically produce up to 100 kW of power. They are often used in water rich areas as a Remote Area Power Supply (RAPS). There are many of these installations around the world, including several delivering around 50 kW in the Solomon Islands.
gravity to the drain tank. A pump (5) sucks oil from a lubricating oil drain tank (3), which in large engines is most often a bottom tank below the main engine. It is fitted with an air vent, level measuring gauge and sounding pipe. To reduce the possibility of contamination of the lubricating oil in the bottom tank as a result of leaks, all the remaining bottom tanks containing, for example, fresh water, seawater or fuel oil, can be separated from the lubricating oil bottom tank by coffer-dams (2). To safeguard the pump, a course filter (4) is inserted between the pump and the bottom tank. The pump forces the oil a through lubricating oil cooler (6) and filters (7) to the main engine (1) where the oil is distributed to bearings and pistons. TURBOCHARGE SYSTEM Most modern engines are turbocharged to increase the power output and efficiency. The efficiency of the system is increased by fitting a charge air cooler after the compressor.
annaabi.ee 
