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Ohm's law

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship: I = V R, where I is the current through the conductor in units of amperes, V is the voltage measured across the conductor in units of volts, R is the resistance of the conductor in units of ohms. More Ohm's law states that the R in this relation is constant, independent of the current. Ohm's law is an empirical relation which describes the conductivity of the vast majority of electrically conductive materials over many orders of magnitude of current; however some materials do not obey Ohm's law, these are called non-ohmic. The law was named after the German physicist Georg Ohm, who, in a treatise published in 1827, described measurements of applied voltage and current through simple electrical circuits containing various lengths of wire.

Ohm explained his experimental results by a more complex equation than the modern form above. In physics, the term Ohm's law is used to refer to various generalizations of the law; this reformulation of Ohm's law is due to Gustav Kirchhoff. In January 1781, before Georg Ohm's work, Henry Cavendish experimented with Leyden jars and glass tubes of varying diameter and length filled with salt solution, he measured the current by noting how strong a shock he felt as he completed the circuit with his body. Cavendish wrote that the "velocity" varied directly as the "degree of electrification", he did not communicate his results to other scientists at the time, his results were unknown until Maxwell published them in 1879. Francis Ronalds delineated “intensity” and “quantity” for the dry pile—a high voltage source—in 1814 using a gold-leaf electrometer, he found for a dry pile that the relationship between the two parameters was not proportional under certain meteorological conditions. Ohm did his work on resistance in the years 1825 and 1826, published his results in 1827 as the book Die galvanische Kette, mathematisch bearbeitet.

He drew considerable inspiration from Fourier's work on heat conduction in the theoretical explanation of his work. For experiments, he used voltaic piles, but used a thermocouple as this provided a more stable voltage source in terms of internal resistance and constant voltage, he used a galvanometer to measure current, knew that the voltage between the thermocouple terminals was proportional to the junction temperature. He added test wires of varying length and material to complete the circuit, he found that his data could be modeled through the equation x = a b + l, where x was the reading from the galvanometer, l was the length of the test conductor, a depended on the thermocouple junction temperature, b was a constant of the entire setup. From this, Ohm published his results. In modern notation we would write, I = E r + R, where E is the open-circuit emf of the thermocouple, r is the internal resistance of the thermocouple and R is the resistance of the test wire. In terms of the length of the wire this becomes, I = E r + R l, where R is the resistance of the test wire per unit length.

Thus, Ohm's coefficients are, a = E R, b = r R. Ohm's law was the most important of the early quantitative descriptions of the physics of electricity. We consider it obvious today; when Ohm first published his work, this was not the case. They called his work a "web of naked fancies" and the German Minister of Education proclaimed that "a professor who preached such heresies was unworthy to teach science." The prevailing scientific philosophy in Germany at the time asserted that experiments need not be performed to develop an understanding of nature because nature is so well ordered, that scientific truths may be deduced through reasoning alone. Ohm's brother Martin, a mathematician, was battling the German educational system; these factors hindered the acceptance of Ohm's work, his work did not become accepted until the 1840s. However, Ohm received recognition for his contributions to science. In the 1850s, Ohm's law was known as such and was considered proved, alternatives, such as "Barlow's law", were discredited, in terms of real applic

Asumi Ōmura

Asumi Ōmura is a Japanese sprint canoeist, born in Shizuoka Prefecture. She won silver and bronze medal in the women's kayak doubles and four at the 2010 Asian Games in Guangzhou, respectively. Ōmura is a member of the canoe and kayak team at Waseda University in Shinjuku, is coached and trained by Octavian Ispas of Romania.Ōmura represented Japan at the 2012 Summer Olympics in London, where she competed in the women's K-2 500 metres. Ōmura and her partner Shinobu Kitamoto failed to advance into the semi-finals, as they placed sixth in the second heat by two seconds behind the Slovakian pair Ivana Kmeťová and Martina Kohlová, with a time of 1:47.323. NBC Olympics Profile

Linda Te Puni

Linda Te Puni is a diplomat from New Zealand of Māori heritage. She has served as the High Commissioner to the Cook Islands from 2010 until 2011 and Tuvalu beginning in 2016, she has been Administrator of Tokelau. Te Puni is a descendant of Honiana Te Puni. Te Puni worked several interesting jobs before becoming a diplomat, including cutting fish in Iceland, as a farmworker in Israel and working in London's pubs. Te Puni joined the Ministry of Foreign Affairs in 1987, she has served in places such as Honiara, Ottawa, Paris and Wellington. In 2010, Te Puni moved to Rarotonga and she became the first woman to become the New Zealand high commissioner to the Cook Islands. Between 2015 and 2016, she was the first woman to hold that role. In 2016, she was appointed as high commissioner to Tuvalu

John Laird (minister)

The Very Rev Dr John Laird DD was a 19th-century Scottish minister of the Free Church of Scotland who served as Moderator of the General Assembly to the Free Church 1889/90. He was born in the manse at Portmoak on the banks of Loch Leven, the son of Rev Hugh Laird DD, his father was minister of the parish from 1802 to 1849. He studied divinity at the University of Edinburgh and was ordained by the Church of Scotland at Arbroath in 1835, he was translated to Inverkeillor in 1836. He joined the Free Church of Scotland. In 1847 he became minister of the Free St George's Church in Montrose. In 1853 he translated to the Free Church in Cupar. In 1870 he organised the rebuilding of the Free Church in Cupar; this was designed by Campbell Douglas and occupied from 1875 but the huge spire was not completed until 1879. In 1889 he was elected Moderator of the General Assembly, he was succeeded in 1890 by Thomas Brown. He died in 1896. In 1840 he married Agnes Maule Anderson, their son Rev David Laird was minister of the Free Church of Durris.

Two of his brothers, A O Laird of Dundee, Henry Laird of Leslie, Fife were Free Church ministers. Two of his sisters married Free Church ministers: Rev Spiers of Kinglassie and Rev James Swinton of Portmoak

Philippine Green Building Council

The Philippine Green Building Council is a national non-stock, non-profit organization that promotes the sharing of knowledge on green practices to the property industry to ensure a sustainable environment. It was organized to serve as a single voice in the promotion of holistic and market-based green building practices, to facilitate the sharing of green building information and practices in the building industry, to serve as a non-partisan venue for the development of the BERDE Green Building Rating System. In early 2006, a group of environmental advocates and business leaders convened to form PHILGBC with the realization that an organization is needed to promote greener buildings and coordinate efforts to sustainability. Incorporated in 2007, PHILGBC has been campaigning for the transformation of design and management methods of the industry into practices that are environmentally and responsible and healthy, a prosperous environment that improves the quality of life. PHILGBC is an Emerging Member of the World Green Building Council and a member of the WorldGBC - Asia Pacific Network.

The Council is a member organization of the International Initiative for a Sustainable Built Environment, a global partner of the GLOBE Alliance. The Building for Ecologically Responsive Design Excellence Program was developed by PHILGBC as an appropriate response to the Philippine building industry’s need to proactively address the negative impacts of climate change in the property sector; the BERDE Green Building Rating System is developed under the BERDE Program. It is a tool to measure and monitor performance of buildings above and beyond existing mandatory building and environmental regulations and standards; the rating tool is consensus driven and is achieved through a multi-stakeholder consultation and collaboration process. BERDE Assessment and Certification is credible, unbiased and impartial and is achieved through a third party certification process conforming with international standards. BERDE is recognized as the National Voluntary Green Building Rating System of the Philippines through the Philippine Energy Efficiency Project: Efficient Building Initiative of the Department of Energy.

Started in 2007, Building Green is the series of conferences of the Philippine Green Building Council that highlights the current green practices of the industry. It features the latest innovative trends in building products, architecture and construction as initiated by the industry's best and brightest minds; the conference series was started as a venue for green building dialogue and to further develop and promote BERDE, as the National Green Building Rating System. Philippine Green Building Council official website BERDE Online World Green Building Council

Scoria

Scoria is a vesicular, dark colored volcanic rock that may or may not contain crystals. It is dark in color, basaltic or andesitic in composition. Scoria is low in density as a result of its numerous macroscopic ellipsoidal vesicles, but in contrast to pumice, all scoria has a specific gravity greater than 1, sinks in water; the holes or vesicles form when gases that were dissolved in the magma come out of solution as it erupts, creating bubbles in the molten rock, some of which are frozen in place as the rock cools and solidifies. Scoria may form as part of a lava flow near its surface, or as fragmental ejecta, for instance in Strombolian eruptions that form steep-sided scoria cones. Chemical analysis of scoria found in Yemen showed that it was composed of volcanic glass with a few zeolites. Most scoria is composed of glassy fragments, may contain phenocrysts; the word scoria comes from the Greek skōria, rust. A colloquial term for scoria is cinder. Scoria differs from pumice, another vesicular volcanic rock, in having larger vesicles and thicker vesicle walls, hence is denser.

The difference is the result of lower magma viscosity, allowing rapid volatile diffusion, bubble growth and bursting. As rising magma encounters lower pressures, dissolved gases are able to form vesicles; some of the vesicles are trapped when the magma solidifies. Vesicles are small, spheroidal and do not impinge upon one another. Volcanic cones of scoria can be left behind after eruptions forming mountains with a crater at the summit. An example is Maungarei in Auckland, New Zealand, which like Te Tatua-a-Riukiuta in the south of the same city has been extensively quarried. Quincan, a unique form of Scoria, is quarried at Mount Quincan in Australia. Scoria has several useful characteristics, it is somewhat porous, has a high surface area and strength for its weight, has striking colours. It is used in landscaping and drainage works, it is commonly used in gas barbecue grills. Scoria can be used for high-temperature insulation, it is used on oil well sites to limit mud problems resulting from heavy truck traffic.

The quarry of Puna Pau on Rapa Nui/Easter Island was the source of a red-coloured scoria which the Rapanui people used to carve the pukao for their distinctive moai statues, to carve some moai themselves. It is used as a traction aid on ice- and snow-covered roads. Cinder – Pyroclastic vesicular rock Extrusive rock – Igneous rock formed by rapid crystallization at the surface Tuff – Rock consolidated from volcanic ash Pumice – Light coloured vesicular volcanic rock Volcano – rupture in the crust of a planetary-mass object that allows hot lava, volcanic ash, gases to escape from a magma chamber below the surface List of rock types – A list of rock types recognized by geologists Rock – A occurring solid aggregate of one or more minerals or mineraloids