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Oxy-hydrogen
Oxyhydrogen is a mixture of hydrogen (H2) and oxygen (O2) gases. This gaseous mixture is used for torches to process refractory materials and was the first gaseous mixture used for welding. Theoretically, a ratio of 2:1 hydrogen:oxygen is enough to achieve maximum efficiency; in practice a ratio 4:1 or 5:1 is needed to avoid an oxidizing flame. This mixture may also be referred to as ' (Scandinavian and German wikt:Knallgas, Knallgas: "bang-gas"), although some authors define knallgas to be a generic term for the mixture of fuel with the precise amount of oxygen required for complete combustion, thus 2:1 oxyhydrogen would be called "hydrogen-knallgas". "Brown's gas" and HHO are terms for oxyhydrogen mainly encountered in fringe science. Properties Oxyhydrogen will combustion, combust when brought to its autoignition temperature. For the stoichiometric mixture, 2:1 hydrogen:oxygen, at normal atmospheric pressure, autoignition occurs at about 570 °C (1065 °F). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knallgas
Oxyhydrogen is a mixture of hydrogen (H2) and oxygen (O2) gases. This gaseous mixture is used for torches to process refractory materials and was the first gaseous mixture used for welding. Theoretically, a ratio of 2:1 hydrogen:oxygen is enough to achieve maximum efficiency; in practice a ratio 4:1 or 5:1 is needed to avoid an oxidizing flame. This mixture may also be referred to as ' (Scandinavian and German wikt:Knallgas, Knallgas: "bang-gas"), although some authors define knallgas to be a generic term for the mixture of fuel with the precise amount of oxygen required for complete combustion, thus 2:1 oxyhydrogen would be called "hydrogen-knallgas". "Brown's gas" and HHO are terms for oxyhydrogen mainly encountered in fringe science. Properties Oxyhydrogen will combustion, combust when brought to its autoignition temperature. For the stoichiometric mixture, 2:1 hydrogen:oxygen, at normal atmospheric pressure, autoignition occurs at about 570 °C (1065 °F). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limelight
Limelight (also known as Drummond light or calcium light)James R. Smith (2004). ''San Francisco's Lost Landmarks'', Quill Driver Books. is a type of stage lighting once used in theatres and music halls. An intense illumination is created when a flame fed by oxygen and hydrogen is directed at a cylinder of quicklime (calcium oxide), which can be heated to before melting. The light is produced by a combination of incandescence and candoluminescence. Although it has long since been replaced by electric lighting, the term has nonetheless survived, as someone in the public eye is still said to be "in the limelight". The actual lamps are called "limes", a term which has been transferred to electrical equivalents. History Discovery and invention The limelight effect was discovered in the 1820s by Goldsworthy Gurney, based on his work with the "oxy-hydrogen blowpipe", credit for which is normally given to Robert Hare. In 1825, a Scottish engineer, Thomas Drummond (1797–1840), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limelight Diagram
Limelight (also known as Drummond light or calcium light)James R. Smith (2004). ''San Francisco's Lost Landmarks'', Quill Driver Books. is a type of stage lighting once used in theatres and music halls. An intense illumination is created when a flame fed by oxygen and hydrogen is directed at a cylinder of quicklime (calcium oxide), which can be heated to before melting. The light is produced by a combination of incandescence and candoluminescence. Although it has long since been replaced by electric lighting, the term has nonetheless survived, as someone in the public eye is still said to be "in the limelight". The actual lamps are called "limes", a term which has been transferred to electrical equivalents. History Discovery and invention The limelight effect was discovered in the 1820s by Goldsworthy Gurney, based on his work with the "oxy-hydrogen blowpipe", credit for which is normally given to Robert Hare. In 1825, a Scottish engineer, Thomas Drummond (1797–1840), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolyser 1884
In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. The voltage that is needed for electrolysis to occur is called the decomposition potential. The word "lysis" means to separate or break, so in terms, electrolysis would mean "breakdown via electricity". Etymology The word "electrolysis" was introduced by Michael Faraday in 1834, using the Greek words "amber", which since the 17th century was associated with electrical phenomena, and ' meaning "dissolution". Nevertheless, electrolysis, as a tool to study chemical reactions and obtain pure elements, precedes the coinage of the term and formal description by Faraday. History In the early nineteenth century, William Nicholson and Anthony Carlisle sought to further Volta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mole (unit)
The mole, symbol mol, is the unit of amount of substance in the International System of Units (SI). The quantity amount of substance is a measure of how many elementary entities of a given substance are in an object or sample. The mole is defined as containing exactly elementary entities. Depending on what the substance is, an elementary entity may be an atom, a molecule, an ion, an ion pair, or a subatomic particle such as an electron. For example, 10 moles of water (a chemical compound) and 10 moles of mercury (a chemical element), contain equal amounts of substance and the mercury contains exactly one atom for each molecule of the water, despite the two having different volumes and different masses. The number of elementary entities in one mole is known as the Avogadro number, which is the approximate number of nucleons (protons or neutrons) in one gram of ordinary matter. The previous definition of a mole was simply the number of elementary entities equal to that of 12 gram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Oxide
Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, Caustic (substance), caustic, alkaline, crystalline solid at room temperature. The broadly used term "''lime (material), lime''" connotes calcium-containing inorganic materials, in which carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. By contrast, ''quicklime'' specifically applies to the single chemical compound calcium oxide. Calcium oxide that survives processing without reacting in building products such as cement is called free lime. Quicklime is relatively inexpensive. Both it and a chemical derivative (calcium hydroxide, of which quicklime is the base anhydride) are important commodity chemicals. Preparation Calcium oxide is usually made by the thermal decomposition of materials, such as limestone or seashells, that contain calcium carbonate (CaCO3; mineral calcite) in a lime kiln. This is accomplished by hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Lighting
Gas lighting is the production of artificial light from combustion of a gaseous fuel, such as hydrogen, methane, carbon monoxide, propane, butane, acetylene, ethylene, coal gas (town gas) or natural gas. The light is produced either directly by the flame, generally by using special mixes (typically propane or butane) of illuminating gas to increase brightness, or indirectly with other components such as the gas mantle or the limelight, with the gas primarily functioning as a heat source for the incandescence of the gas mantle or lime. Before electricity became sufficiently widespread and economical to allow for general public use, gas was the most prevalent method of outdoor and indoor lighting in cities and suburbs, areas where the infrastructure for distribution of the gaseous fuel was practical. When gas lighting was prevalent, the most common fuels for gas lighting were wood gas, coal gas and, in limited cases, water gas. Early gas lights were ignited manually by lampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second Law Of Thermodynamics
The second law of thermodynamics is a physical law based on universal experience concerning heat and Energy transformation, energy interconversions. One simple statement of the law is that heat always moves from hotter objects to colder objects (or "downhill"), unless energy in some form is supplied to reverse the direction of heat flow. Another definition is: "Not all heat energy can be converted into Work (thermodynamics), work in a cyclic process."Young, H. D; Freedman, R. A. (2004). ''University Physics'', 11th edition. Pearson. p. 764. The second law of thermodynamics in other versions establishes the concept of entropy as a physical property of a thermodynamic system. It can be used to predict whether processes are forbidden despite obeying the requirement of conservation of energy as expressed in the first law of thermodynamics and provides necessary criteria for spontaneous processes. The second law may be formulated by the observation that the entropy of isolated systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Law Of Thermodynamics
The first law of thermodynamics is a formulation of the law of conservation of energy, adapted for thermodynamic processes. It distinguishes in principle two forms of energy transfer, heat and thermodynamic work for a system of a constant amount of matter. The law also defines the internal energy of a system, an extensive property for taking account of the balance of energies in the system. The law of conservation of energy states that the total energy of any isolated system, which cannot exchange energy or matter, is constant. Energy can be transformed from one form to another, but can be neither created nor destroyed. The first law for a thermodynamic process is often formulated asThe sign convention (Q is heat supplied ''to'' the system but W is work done ''by'' the system) is that of Rudolf Clausius (Equation IIa on page 384 of Clausius, R. (1850)), and it is followed below. :\Delta U = Q - W, where \Delta U denotes the change in the internal energy of a closed system (f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Nicholson (chemist)
William Nicholson (13 December 175321 May 1815) was an English writer, translator, publisher, scientist, inventor, patent agent and civil engineer. He launched the first monthly scientific journal in Britain, ''Journal of Natural Philosophy, Chemistry, and the Arts'', in 1797, and remained its editor until 1814. In 1800, he and Anthony Carlisle were the first to achieve electrolysis, the splitting of water into hydrogen and oxygen, using a voltaic pile. Nicholson also wrote extensively on natural philosophy and chemistry Early life Nicholson was educated in Yorkshire, and after leaving school, he made two voyages as a midshipman in the service of the British East India Company. His first voyage was to India and the second voyage was to China on board the ''Gatton,'' (1772-1773). Subsequently, having become acquainted with Josiah Wedgwood in 1775, he moved to Amsterdam, where he made a living for a few years as Wedgwood's agent. On his return to England he was persuaded by Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Current
An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume. The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or holes. In an electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons. The SI unit of electric current is the ampere, or ''amp'', which is the flow of electric charge across a surface at the rate of one coulomb per second. The ampere (symbol: A) is an SI base unit. Electric current is measured using a device called an ammeter. Electric currents create magnetic fields, which are used in motors, generators, inductors, and transformers. In ordinary con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolysis Of Water
Electrolysis of water, also known as electrochemical water splitting, is the process of using electricity to decompose water into oxygen and hydrogen gas by electrolysis. Hydrogen gas released in this way can be used as hydrogen fuel, or remixed with the oxygen to create oxyhydrogen gas, which is used in welding and other applications. Electrolysis of water requires a minimum potential difference of 1.23 volts, though at that voltage external heat is required. E lectrolysis is rarely used in industrial applications since hydrogen can be produced less expensively from fossil fuels. History In 1789, Jan Rudolph Deiman and Adriaan Paets van Troostwijk used an electrostatic machine to make electricity that was discharged on gold electrodes in a Leyden jar with water. In 1800 Alessandro Volta invented the voltaic pile, and a few weeks later English scientists William Nicholson and Anthony Carlisle used it to electrolyse water. In 1806 Humphry Davy reported the results of ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
