Hrvatska elektroprivreda is a national power company in Croatia, engaged in electricity production and distribution for more than one century, with heat supply and gas distribution for the past few decades. HEP Group is organized in the form of a holding company with a number of daughter companies. HEP claims to be the oldest electric company distributing alternating current, tracing its foundation to 1895 when the first European power plant Jaruga Hydroelectric Power Plant was built, only three days after the Adams Power Plant at Niagara Falls; the parent company of HEP Group, HEP d.d. performs the function of HEP Group corporate management. Production is delegated to two subsidiaries: HEP Proizvodnja d.o.o. which deals with a majority of generation facilities, TE Plomin d.o.o., co-owned by HEP and RWE Power, operates Plomin themal power plant. HEP owns 50% of Krško Nuclear Power Plant in Slovenia. HEP Operator prijenosnog sustava d.o.o. and HEP Operator distribucijskog sustava d.o.o. are providers of public services of electricity transmission and distribution for the needs of participants in the Croatian market.
HEP ODS is responsible for supplying tariff customers, while supplying eligible customers falls under the jurisdiction of HEP Opskrba d.o.o. Other business activities include: district heating, gas distribution, energy efficiency, environmental protection with a focus on waste management, renewable energy sources and training and leisure and recreation. European Network of Transmission System Operators for Electricity Company website
Hydroelectricity is electricity produced from hydropower. In 2015, hydropower generated 16.6% of the world's total electricity and 70% of all renewable electricity, was expected to increase about 3.1% each year for the next 25 years. Hydropower is produced in 150 countries, with the Asia-Pacific region generating 33 percent of global hydropower in 2013. China is the largest hydroelectricity producer, with 920 TWh of production in 2013, representing 16.9 percent of domestic electricity use. The cost of hydroelectricity is low, making it a competitive source of renewable electricity; the hydro station consumes no water, unlike gas plants. The average cost of electricity from a hydro station larger than 10 megawatts is 3 to 5 U. S. cents per kilowatt hour. With a dam and reservoir it is a flexible source of electricity since the amount produced by the station can be varied up or down rapidly to adapt to changing energy demands. Once a hydroelectric complex is constructed, the project produces no direct waste, in many cases, has a lower output level of greenhouse gases than fossil fuel powered energy plants.
Hydropower has been used since ancient times to perform other tasks. In the mid-1770s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique which described vertical- and horizontal-axis hydraulic machines. By the late 19th century, the electrical generator was developed and could now be coupled with hydraulics; the growing demand for the Industrial Revolution would drive development as well. In 1878 the world's first hydroelectric power scheme was developed at Cragside in Northumberland, England by William Armstrong, it was used to power a single arc lamp in his art gallery. The old Schoelkopf Power Station No. 1 near Niagara Falls in the U. S. side began to produce electricity in 1881. The first Edison hydroelectric power station, the Vulcan Street Plant, began operating September 30, 1882, in Appleton, with an output of about 12.5 kilowatts. By 1886 there were 45 hydroelectric power stations in the U. S. and Canada. By 1889 there were 200 in the U. S. alone. At the beginning of the 20th century, many small hydroelectric power stations were being constructed by commercial companies in mountains near metropolitan areas.
Grenoble, France held the International Exhibition of Hydropower and Tourism with over one million visitors. By 1920 as 40% of the power produced in the United States was hydroelectric, the Federal Power Act was enacted into law; the Act created the Federal Power Commission to regulate hydroelectric power stations on federal land and water. As the power stations became larger, their associated dams developed additional purposes to include flood control and navigation. Federal funding became necessary for large-scale development and federally owned corporations, such as the Tennessee Valley Authority and the Bonneville Power Administration were created. Additionally, the Bureau of Reclamation which had begun a series of western U. S. irrigation projects in the early 20th century was now constructing large hydroelectric projects such as the 1928 Hoover Dam. The U. S. Army Corps of Engineers was involved in hydroelectric development, completing the Bonneville Dam in 1937 and being recognized by the Flood Control Act of 1936 as the premier federal flood control agency.
Hydroelectric power stations continued to become larger throughout the 20th century. Hydropower was referred to as white coal for its plenty. Hoover Dam's initial 1,345 MW power station was the world's largest hydroelectric power station in 1936; the Itaipu Dam opened in 1984 in South America as the largest, producing 14,000 MW but was surpassed in 2008 by the Three Gorges Dam in China at 22,500 MW. Hydroelectricity would supply some countries, including Norway, Democratic Republic of the Congo and Brazil, with over 85% of their electricity; the United States has over 2,000 hydroelectric power stations that supply 6.4% of its total electrical production output, 49% of its renewable electricity. The technical potential for hydropower development around the world is much greater than the actual production: the percent of potential hydropower capacity that has not been developed is 71% in Europe, 75% in North America, 79% in South America, 95% in Africa, 95% in the Middle East, 82% in Asia-Pacific.
The political realities of new reservoirs in western countries, economic limitations in the third world and the lack of a transmission system in undeveloped areas result in the possibility of developing 25% of the remaining technically exploitable potential before 2050, with the bulk of that being in the Asia-Pacific area. Some countries have developed their hydropower potential and have little room for growth: Switzerland produces 88% of its potential and Mexico 80%. Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator; the power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head. A large pipe delivers water from the reservoir to the turbine; this method produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand, the excess generation capacity is used to pump water into the higher reservoir.
When the demand becomes greater, water is released back into the lower reservoir through a turbine. Pumped-storage schemes provide the most commercially important means of large-scale grid energy storage and improve the daily capacity factor of the generation system. Pumped storag
The Hep-Hep riots from August to October 1819 were pogroms against Ashkenazi Jews, beginning in the Kingdom of Bavaria, during the period of Jewish emancipation in the German Confederation. The antisemitic communal violence began on August 2, 1819 in Würzburg and soon reached the outer regions of the German Confederation. Many Jews were killed and much Jewish property was destroyed; the riots took place in a period of heightened political and social tension, shortly following the end of the Napoleonic Wars in 1815 and the great famine of 1816-17, on the eve of the repressive Carlsbad Decrees. In many German cities, emancipation of the Jews had only begun in recent years, after centuries of living in the countries of Central Europe as non-citizens with restricted rights; the status of Jews varied throughout free cities. In most German territories, Jews were excluded from posts in public administration and the army and forbidden to hold teaching positions in schools and universities. Jewish representatives formally demanded emancipation at the Congress of Vienna, German academics and politicians alike responded with vicious opposition.
The Jews were portrayed to the public as "upstarts" who were attempting to take control of the economy the financial sector. Antisemitic publications became common in the German press. Influenced by the Haskalah, as well as the French Revolution with its Declaration of the Rights of Man and of the Citizen and other advancements in civil rights, many Jews and equal rights activists began to demand citizenship and equal treatment; as Jewish Emancipation progressed, German Jews were becoming competitors for Christian guilds in the economy. Before the riots began, the Bavarian Diet had completed a debate on further emancipation of the Jews throughout the Kingdom. Amos Elon writes in his 2002 book The Pity of It All: A History of the Jews in Germany, 1743–1933: In some places, attempts were made to return Jews to their old medieval status; the free city of Frankfurt reinstated parts of the medieval statute that restricted the rights of Jews. As of 1816 only twelve Jewish couples were allowed to marry each year.
The 400,000 gulden the community had paid the city government in 1811 in return for its emancipation were declared forfeited. In the Rhineland, which had reverted to Prussian control, Jews lost the citizenship rights they had been granted under the French and were no longer allowed to practice certain professions; the few, appointed to public office before the war were summarily dismissed. "Hep-Hep" was the perpetrators' derogatory rallying cry. The most explanation is that it was based on the traditional herding cry of German shepherds.. One theory is that it is an acronym from the Latin "Hierosolyma est perdita", said to have been a rallying cry of the Crusaders; the "acronym theory" was attributed to a single letter published in a British newspaper on 28 August 1819, some weeks after the riots. Cornell's Michael Fontaine disputes this etymology, concluding that the "acrostic interpretation... has no basis in fact.". Ritchie Robertson disputes the "false etymology" of the acronym interpretation, citing Katz.
The riots began on 2 August 1819 in Würzburg. After several days troops were called in; the Jewish population spent several days in tents in the vicinity. Several Jews were killed during the riots in Würzburg; the riots swept through other Bavarian towns and villages spread to Bamberg, Darmstadt, Mannheim, Koblenz and other cities along the Rhine, as far north as Bremen, Lübeck. In some towns, the police appeared too late or stood by idly while the mob raged through the streets. In towns where the militia arrived promptly, the riots were put down quickly. In Heidelberg the police were tardy in their response, but two professors and their students took the law into their hands and prevented a bloody pogrom, they made citizen's arrests. With the exception of Heidelberg, townspeople remained passive bystanders. In several cities, members of the bourgeoisie and university professors were among the instigators. Ludwig Robert, a Jewish playwright who had converted to Christianity, gave an eyewitness account of the rioting: "...
I walked all the way to the Waldhorngasse. There I caught sight of the commandant of the city, General Bruckner, on horseback, as there was still sporadic shouting, he told his patrol: "Let the bastards shout away if they insist, but the minute they do something dumb, let them have it!" Everyone in town was standing at their open windows, I went back close to the buildings, so that I could hear what was being said and assess the mood. Children were playing in front of the doorsteps and giggling, but none of the men or women admonished them or engaged them in serious conversation. And there was less chance of seeing a priest though in my opinion this was where they ought to have been, as teachers of the religion that holds love in such esteem." "How corrupt people are and how inadequate their sense of law and justice not to mention their love of humanity – is clear from the fact that there was no indignation expressed at these incidents, not in the official papers.... The townspeople are said to have been angry with Bruckner for closing the taverns right away.
They threatened to tear him off his horse." After three days of pogrom in Karlsruhe, the infantry was called in and cannons were
High-explosive squash head
High-explosive squash head is a type of explosive ammunition, effective against tank armour and is useful against buildings. It was fielded chiefly by the British Army as the main explosive round of its main battle tanks during the Cold War, it was used by other military forces those that acquired the early post-World War 2 British 105 mm Royal Ordnance L7A1, including Germany, India and Sweden. In the United States, it is known as HEP, for "high explosive, plastic". HESH rounds are thin metal shells filled with a delayed-action base fuze; the plastic explosive is "squashed" against the surface of the target on impact and spreads out to form a disc or "pat" of explosive. The base fuze detonates the explosive milliseconds creating a shock wave that, owing to its large surface area and direct contact with the target, is transmitted through the material. In the case of the metal armour of a tank, the compression shock wave is conducted through the armour to the point where it reaches the metal/air interface, where some of the energy is reflected as a tension wave.
At the point where the compression and tension waves intersect, a high-stress zone is created in the metal, causing pieces of steel to be projected off the interior wall at high velocity. This fragmentation by blast wave is known with the fragments themselves known as spall; the spall travels through the interior of the vehicle at high velocity, killing or injuring the crew, damaging equipment, and/or igniting ammunition and fuel. Unlike high-explosive anti-tank rounds, which are shaped charge ammunition, HESH shells are not designed to perforate the armour of main battle tanks. HESH shells rely instead on the transmission of the shock wave through the solid steel armour. HESH ammunition has good general purpose use, being effective against most targets, though the round is used at low velocities because high velocity excessively disperses the pat of explosive. While only effective against tanks without spaced armour or spall liners, the round is still favoured for combat demolition purposes.
The flattened high-velocity explosive pat is capable of destroying concrete constructions much faster than a HEAT round, without the dangerous fragmentation of a traditional high-explosive fragmentation round. HESH was developed by Dennistoun Burney in the 1940s for the British war effort as an anti-fortification "wallbuster" munition for use against concrete, he led British developments in recoilless rifles as a means to deliver the shell. An early application of the HESH principle was the Royal Engineers AVRE's 165mm demolition gun. HESH was found to be effective against metallic armour as well, although the British had effective weapons using HEAT, such as the PIAT. HESH was for some time a competitor to the more common HEAT round, again in combination with recoilless rifles as infantry weapons, was effective against tanks such as the earlier models of the T-55 and T-62. Versions had a layer of spall liner, which decreased the effectiveness of the HESH round. In the 1960s, Britain devised anti-tank guided missiles with HESH warheads, such as the Malkara, although most subsequent designs used variants of the HEAT concept.
Since the 1970s, HESH ammunition has fallen out of favour as armour designs have trended towards layered composites of hard metal and heat-resistant materials. This type of armour is a poor conductor of shock waves. Anti-spalling devices, made of materials such as Kevlar, are fitted to the interior surface of modern armoured vehicles to mitigate spalling effects. Another reason for the declining use of HESH rounds is the preference of most armies for smoothbore cannons. Rifling decreases the penetrating power of HEAT warheads because the centrifugal force of the spinning projectile tends to disperse the shaped charge jet, but this same effect can assist a HESH shell by increasing the surface area of contact; the British Army has persisted with a rifled cannon on their Challenger 1 and Challenger 2 battle tanks to preserve the general purpose capability of HESH ammunition. The British Army had planned for a conversion to the more versatile smoothbore cannons, but the project was cancelled due to budget constraints.
This would have allowed them to take advantage of commonality with NATO partners and the greater availability of smoothbore ammunition types, such as high-explosive, time-fuzed and canister shot. British rifled tanks have been limited to two offensive ammunition types: CHARM, a kinetic energy penetrator, HESH, but not HEAT. HESH rounds are still carried by armoured engineer vehicles. A 165mm HESH round is used by the United States Army for the main gun of the M728 Combat Engineer Vehicle, an M60 tank equipped with a bulldozer blade; the British Centurion AVRE was equipped with a short 165mm gun for a 29 kg HESH shell. Amongst other ammunition types, the Stryker Mobile Gun System variant is to be equipped with a 105mm HESH round for demolition and bunker-busting purposes. Argentina's TAM medium tanks, Canada's Leopard C1 and Leopard C2 main battle tanks, the Chinese VT-4 Main Battle Tank and India's Arjun tank can fire HESH rounds. Misznay–Schardin effect Munroe effect
In rail transport, head-end power known as electric train supply is the electrical power distribution system on a passenger train. The power source a locomotive at the front or'head' of a train, provides the electricity used for heating, lighting and other'hotel' needs; the maritime equivalent is hotel electric power. A successful attempt by the London and South Coast Railway in October 1881 to light the passenger car between London and Brighton heralded the beginning of using electricity to light trains in the world. Oil lamps were introduced in 1842 to light trains. Economics drove the Lancashire and Yorkshire Railway to replace oil with coal gas lighting in 1870, but a gas cylinder explosion on the train led them to abandon the experiment. Oil-gas lighting was introduced in late 1870. Electrical lighting was introduced in October 1881 by using twelve Swan carbon filament incandescent lamps connected to an underslung battery of 32 Faure lead-acid rechargeable cells, suitable for about 6 hours lighting before being removed for recharging.
The North British Railway in 1881 generated electricity using a dynamo on the Brotherhood steam locomotive to provide electrical lighting in a train, a concept, called head-end power. High steam consumption led to abandonment of the system. Three trains were started in 1883 by London and South Coast Railway with electricity generated on board using a dynamo driven from one of the axles; this charged a lead-acid battery in the guard's van, the guard operated and maintained the equipment. The system provided electric lighting in the train. In 1887, steam-driven generators in the baggage cars of the Florida Special and the Chicago Limited trains in the US supplied electric lighting to all the cars of the train by wiring them, to introduce the other form of head-end power; the oil-gas lighting provided a higher intensity of light compared to electric lighting and was more popularly used till September 1913, when an accident on the Midland Railway at Aisgill caused a large number of passenger deaths.
This accident prompted railways to adopt electricity for lighting the trains. Throughout the remainder of the age of steam and into the early diesel era, passenger cars were heated by low pressure saturated steam supplied by the locomotive, with the electricity for car lighting and ventilation being derived from batteries charged by axle-driven generators on each car, or from engine-generator sets mounted under the carbody. Starting in the 1930s, air conditioning became available on railcars, with the energy to run them being provided by mechanical power take offs from the axle, small dedicated engines or propane; the resulting separate systems of lighting power, steam heat, engine-driven air conditioning, increased the maintenance workload as well as parts proliferation. Head-end power would allow for a single power source to handle all those functions, more, for an entire train. In the steam era, all cars in Finland and Russia had a coal fired fireplace; such a solution was considered a fire danger in most countries in Europe, but not in Russia.
Trains hauled by a steam locomotive would be provided with a supply of steam from the locomotive for heating the carriages. When diesel locomotives and electric locomotives replaced steam, the steam heating was supplied by a steam-heat boiler; this was heated by an electric element. Oil-fired steam-heat boilers were unreliable, they caused more locomotive failures on any class to which they were fitted than any other system or component of the locomotive, this was a major incentive to adopt a more reliable method of carriage heating. At this time, lighting was powered by batteries which were charged by a dynamo underneath each carriage when the train was in motion, buffet cars would use bottled gas for cooking and water heating. Diesels and electric locomotives were equipped with Electric Train Heating apparatus, which supplied electrical power to the carriages to run electric heating elements installed alongside the steam-heat apparatus, retained for use with older locomotives. Carriage designs abolished the steam-heat apparatus, made use of the ETH supply for heating, ventilation, air conditioning, fans and kitchen equipment in the train.
In recognition of this ETH was renamed Electric Train Supply. Each coach has an index relating to the maximum consumption of electricity; the sum of all the indices must not exceed the index of the locomotive. One "ETH index unit" equals 5 kW; the first advance over the old axle generator system was developed on the Boston and Maine Railroad, which had placed a number of steam locomotives and passenger cars into dedicated commuter service in Boston. Due to the low average speeds and frequent stops characteristic of a commuter operation, the axle generators' output was insufficient to keep the batteries charged, resulting in passenger complaints about lighting and ventilation failures. In response, the railroad installed higher capacity generators on the locomotives assigned to these trains, provided electrical connections to the cars; the cars used steam from the locomotive for heating. Some early diesel streamliners took advantage of their fixed-consist construction to employ electrically-powered lighting, air conditioning, heating.
As the cars were not meant to mix with existing passenger stock, compatibility of these systems was not a concern. For example, the Nebraska Zephyr trainset has three diesel generator sets in the first car to power onboard equipment; when diese
Healthy eating pyramid
The Healthy Eating Pyramid is a nutrition guide developed by the Harvard School of Public Health, suggesting quantities of each food category that a human should eat each day. The healthy eating pyramid is intended to provide a sound eating guide than the widespread food guide pyramid created by the USDA; the new pyramid aims to include more recent research in dietary health not present in the USDA's 1992 guide. The original USDA pyramid has been criticized for not differentiating between refined grains and whole grains, between saturated fats and unsaturated fats, for not placing enough emphasis on exercise and weight control. In general terms, the healthy eating pyramid recommends the following intake of different food groups each day, although exact amounts of calorie intake depends on sex and lifestyle: At most meals, whole grain foods including oatmeal, whole-wheat bread, brown rice. Plant oils, including olive oil, canola oil, soybean oil, corn oil, sunflower seed oil. 2–3 servings of fruits.
1–3 servings of nuts, or legumes. 1–2 servings of dairy or calcium supplement. 1–2 servings of poultry, fish, or eggs. Sparing use of white rice, white bread, potatoes and sweets. 5 A Day Dietary supplement Dieting List of diets Essential nutrient Food and Nutrition Service Food pyramid Food Balance Wheel Functional food Health food restaurants Healthy diet Human nutrition MyPlate Nutrition Education Orthorexia nervosa