Energy density

Energy density is the amount of energy stored in a given system or region of space per unit volume. Colloquially it may be used for energy per unit mass, though the accurate term for this is specific energy. Only the useful or extractable energy is measured, to say that inaccessible energy is ignored. In cosmological and other general relativistic contexts, the energy densities considered are those that correspond to the elements of the stress–energy tensor and therefore do include mass energy as well as energy densities associated with the pressures described in the next paragraph. Energy per unit volume has the same physical units as pressure, in many circumstances is a synonym: for example, the energy density of a magnetic field may be expressed as a physical pressure, the energy required to compress a compressed gas a little more may be determined by multiplying the difference between the gas pressure and the external pressure by the change in volume. In short, pressure is a measure of the enthalpy per unit volume of a system.

A pressure gradient has the potential to perform work on the surroundings by converting enthalpy to work until equilibrium is reached. There are different types of energy stored in materials, it takes a particular type of reaction to release each type of energy. In order of the typical magnitude of the energy released, these types of reactions are: nuclear, chemical and electrical. Nuclear reactions take place in stars and nuclear power plants, both of which derive energy from the binding energy of nuclei. Chemical reactions are used by animals to derive energy from food, by automobiles to derive energy from gasoline. Liquid hydrocarbons are today the most dense way known to economically store and transport chemical energy at a large scale. Electrochemical reactions are used by most mobile devices such as laptop computers and mobile phones to release the energy from batteries. There are several different types of energy content. One is the theoretical total amount of thermodynamic work that can be derived from a system, with a given temperature and pressure for the surroundings.

This is called exergy. Another is the theoretical amount of work that can be derived from reactants that are at room temperature and atmospheric pressure; this is given by the change in standard Gibbs free energy. But as a source of heat or for use in a heat engine, the relevant quantity is the change in standard enthalpy or the heat of combustion. There are two kinds of heat of combustion: The higher value, or gross heat of combustion, includes all the heat released as the products cool to room temperature and whatever water vapor is present condenses; the lower value, or net heat of combustion, does not include the heat which could be released by condensing water vapor, may not include the heat released on cooling all the way down to room temperature. A convenient table of HHV and LHV of some fuels can be found in the references. In energy storage applications the energy density relates the energy in an energy store to the volume of the storage facility, e.g. the fuel tank. The higher the energy density of the fuel, the more energy may be stored or transported for the same amount of volume.

The energy density of a fuel per unit mass is called the specific energy of that fuel. In general an engine using that fuel will generate less kinetic energy due to inefficiencies and thermodynamic considerations—hence the specific fuel consumption of an engine will always be greater than its rate of production of the kinetic energy of motion. Energy density differs from embodied energy. Large scale, intensive energy use impacts and is impacted by climate, waste storage, environmental consequences. No single energy storage method boasts the best in specific power, specific energy, energy density. Peukert's law describes how the amount of useful energy that can be obtained depends on how it is pulled out. To maximize both specific energy and energy density, one can compute the specific energy density of a substance by multiplying the two values together, where the higher the number, the better the substance is at storing energy efficiently. Alternative options are discussed for energy storage to increase energy density and decrease charging time.

Gravimetric and volumetric energy density of some fuels and storage technologies: Note: Some values may not be precise because of isomers or other irregularities. See Heating value for a comprehensive table of specific energies of important fuels. Note: Also it is important to realise that the density values for chemical fuels do not include the weight of oxygen required for combustion; this is two oxygen atoms per carbon atom, one per two hydrogen atoms. The atomic weight of carbon and oxygen are similar. Figures are presented this way for those fuels where in practice air would only be drawn in locally to the burner; this explains the lower energy density of materials that include their own oxidiser, where the mass of the oxidiser in effect adds dead weight, absorbs some of the energy of combustion to dissociate and liberate oxygen to continue the reaction. This explains some apparent anomalies, such as the energy density of a sandwich appearing to be higher than that of a stick of dynamite.

Unless otherwise stated, the values in the fo

Great Britain at the 1896 Summer Olympics

Ten athletes from the United Kingdom of Great Britain and Ireland competed in seven sports at the 1896 Summer Olympics. The Great Britain athletes were the fifth most successful in terms of overall medals and tied for fifth in gold medals; the 7 medals came on 23 entries in 14 events. Two tennis players played in mixed team squads, contributing to a gold and a bronze medal; these medals are not counted as part of the Great Britain total. The British athletes took a fourth-place finish in athletics; the 100 metres and the 800 metres were the two events. Battell and Keeping each won a medal in the cycling program, earning a 4th place and a 5th-place finish as well. Elliot finished in last place in the rope climbing competition, he did not make it all the way up the 14-metre rope. Merlin and Machonet were unable to win any medals in the shooting events. Boland was by far the best player in the tennis competition, amassing a 6-0 record over both events and two gold medals, though one of them was as part of a mixed team.

He defeated Traun in the first round of the singles competition teamed up with him for the doubles competition. Robertson was much less successful, losing both of the matches he played, though he was awarded a retroactive bronze medal by the International Olympic Committee as his bye in the doubles quarterfinals put him in third place in that event. Like Boland's doubles gold medal, Robertson's bronze is not counted as part of the British total because the two played on mixed teams. Elliot lifted the same amount as Viggo Jensen in the two handed lift, but was declared by Prince George of Greece to have taken second place based on lifting form. In the one handed lift, he defeated Jensen, who lifted only 57 kilograms. Elliot was defeated by eventual champion Carl Schuhmann in the first round of the wrestling competition, tying for 4th and last place. Lampros, S. P.. G.. J.. The Olympic Games: BC 776 – AD 1896. Athens: Charles Beck. Mallon, Bill; the 1896 Olympic Games. Results for All Competitors in All Events, with Commentary.

Jefferson: McFarland. ISBN 0-7864-0379-9. Smith, Michael Llewellyn. Olympics in Athens 1896; the Invention of the Modern Olympic Games. London: Profile Books. ISBN 1-86197-342-X

Nova Widianto

Nova Widianto is a former male badminton player from Indonesia. He is the Indonesia national team mixed doubles assistant coach. Nova Widianto is considered as one of the greatest doubles player in his era, he is known for his superb movement on versatility to be paired with various players. Widianto specialized in mixed doubles, he enjoyed some international success with Vita Marissa, winning the Southeast Asian Games in 2001, the Asian Badminton Championships in 2003, the Japan Open in 2004. However, his greatest success came from a partnership with Lilyana Natsir, they have been one of the world's three leading teams. In 2005, they were able to win the World Championships in 2005, beating Xie Zhongbo and Zhang Yawen in the final; the pair once more captured the gold medal by beating Zheng Bo and Gao Ling. They claimed the silver medals at the 2008 Olympic Games, having a shocking loss to the world number 10, Lee Yong Dae and Lee Hyo-jung. At the 2009 BWF World Championships, they earned the silver medal, losing to the Danish pair.

He was the runner up three times in a row, from 2006 to 2008, at the Japan open. They have been runner up at the All England Championships twice, the narrowest one was at 2010, beaten by future Olympic champion, Zhang Nan and Zhao Yunlei, 18-21 25-23 18-21 in an hour and 31 minutes, considered as one of the best mixed doubles game that played. Widianto has represented Indonesia in the Sudirman Cup five times: 2001, 2003, 2005, 2007 and 2009, he competed in badminton at the 2004 Summer Olympics in mixed doubles with partner Vita Marissa and only reached the quarterfinal, after being defeated in the quarterfinal by the Danish pair. He competed in badminton at the 2008 Summer Olympics as the 1st seed in mixed doubles with partner Lilyana Natsir and reached the final by beating He Hanbin and Yu Yang in the semifinal with thrilling scores, 15–21 21–11 23–21. In the final, they were defeated by gold medalists, Lee Yong-dae and Lee Hyo-jung of South Korea in straight sets, 21–11 and 21–17; when he was young, he joined the Tangkas Jakarta badminton club.

The parent's names are Sutari. His hobby is football. People called him Nova or Kedheng. He's married former Indonesian national player Eny Widiowati, he followed some tournaments in men's doubles. He played with Candra Wijaya for a few months, preparing for Thomas Cup event and succeeded to be the runner up of Asian Badminton Championships, lost to Jung Jae Sung and Lee Yong-dae in the final, 21–16 21–18, he helped Indonesia to claim gold medal in men's team in Southeast Asian Games, partnering with Muhammad Ahsan and beat Mohd Zakry Abdul Latif and Mohd Fairuzizuan Mohd Tazari, 21–18 21–17 to give 3–1 win against Malaysia. His powerful smash and accurate placement on the court have been a crucial part of Nova's game to dominate the mixed doubles and being at the top level, his mental strength and great spirit become the decisive factor to win the game and somehow manage to be the other source of his power. The other thing is his ability to keep retrieving the shuttle with such tricky technique able to make his opponent goes into the trouble.

Mixed doubles 2008 Summer Olympics at the Beijing University of Technology Gymnasium, ChinaWidianto competed in badminton at the 2008 Summer Olympics in mixed doubles with partner Liliyana Natsir and earned a silver medal. They were defeated in the final by the gold medalists Lee Yong-dae and Lee Hyo-jung of South Korea in straight sets 21–11 and 21–17. 2004 Summer Olympics at the Goudi Olympic Hall, Greece Mixed doubles 2009 BWF World Championships at the Gachibowli Indoor Stadium in Hyderabad, India2007 BWF World Championships at the Putra Indoor Stadium in Kuala Lumpur, Malaysia2005 IBF World Championships at the Arrowhead Pond in Anaheim, United States Mixed doubles Mixed doubles Men's doubles Mixed doubles Mixed doubles The BWF Superseries, launched on 14 December 2006 and implemented in 2007, is a series of elite badminton tournaments, sanctioned by Badminton World Federation. BWF Superseries has two level such as Superseries Premier. A season of Superseries features twelve tournaments around the world, which introduced since 2011, with successful players invited to the Superseries Finals held at the year end.

Mixed doubles BWF Superseries Finals tournament BWF Superseries Premier tournament BWF Superseries tournament The BWF Grand Prix has two levels: Grand Prix and Grand Prix Gold. It is a series of badminton tournaments, sanctioned by Badminton World Federation since 2007; the World Badminton Grand Prix sanctioned by International Badminton Federation since 1983. Mixed doubles BWF Grand Prix Gold tournament BWF & IBF Grand Prix tournament Men's doubles Mixed doubles Senior level Senior level Nova Widianto at Nova Widianto at Olympics at Nova Widianto at the International Olympic Committee