The IUPAC defines calcination as "heating to high temperatures in air or oxygen". However, calcination is used to mean a thermal treatment process in the absence or limited supply of air or oxygen applied to ores and other solid materials to bring about a thermal decomposition. A calciner is a steel cylinder that rotates inside a heated furnace and performs indirect high-temperature processing within a controlled atmosphere; the process of calcination derives its name from the Latin calcinare due to its most common application, the decomposition of calcium carbonate to calcium oxide and carbon dioxide, in order to create cement. The product of calcination is referred to in general as "calcine", regardless of the actual minerals undergoing thermal treatment. Calcination is carried out in furnaces or reactors of various designs including shaft furnaces, rotary kilns, multiple hearth furnaces, fluidized bed reactors. Examples of calcination processes include the following: decomposition of carbonate ores, as in the calcination of limestone to drive off carbon dioxide.
Several reports on Microwave Assisted Calcination methods were made in 2011 years. Calcination reactions take place at or above the thermal decomposition temperature or the transition temperature; this temperature is defined as the temperature at which the standard Gibbs free energy for a particular calcination reaction is equal to zero. For example, in limestone calcination, a decomposition process, the chemical reaction is CaCO3 → CaO + CO2The standard Gibbs free energy of reaction is approximated as ΔG°r = 177,100 − 158 T; the standard free energy of reaction is 0 in this case when the temperature, T, is equal to 1121 K, or 848 °C. See calcination equilibrium of calcium carbonate Calcination can be used in carbon negative electricity generation. In some cases, calcination of a metal results in oxidation of the metal. Jean Rey noted that lead and tin when calcinated gained weight as they were being oxidized. In alchemy, calcination was believed to be one of the 12 vital processes required for the transformation of a substance.
Alchemists distinguished two kinds of calcination and potential. Actual calcination is that brought about by actual fire, from wood, coals, or other fuel, raised to a certain temperature. Potential calcination is that brought about by potential fire, such as corrosive chemicals. There was philosophical calcination, said to occur when horns, etc. were hung over boiling water, or other liquor, until they had lost their mucilage, were reducible into powder
Elizabeth Fulhame was a Scottish chemist who invented the concept of catalysis and discovered photoreduction. She describes catalysis as a process at length in her 1794 book An Essay On Combustion with a View to a New Art of Dying and Painting, wherein the Phlogistic and Antiphlogistic Hypotheses are Proved Erroneous; the book relates in painstaking detail her experiments with oxidation-reduction reactions, the conclusions she draws regarding Phlogiston theory, in which she disagrees with both the Phlogistians and Antiphlogistians. In 1798, the book was translated into German by Augustin Gottfried Ludwig Lentin as Versuche über die Wiederherstellung der Metalle durch Wasserstoffgas. In 1810, it was published to much critical acclaim; that same year, Fulhame was made an honorary member of the Philadelphia Chemical Society. Thomas P. Smith applauded her work, stating that "Mrs. Fulham has now laid such bold claims to chemistry that we can no longer deny the sex the privilege of participating in this science also."
Elizabeth Fulhame published as Mrs. Fulhame, she was married to Thomas Fulhame, an Irish-born physician who had attended the University of Edinburgh and studied puerperal fever. Elizabeth herself is believed to have been Scottish. Sir Benjamin Thompson, Count Rumford, referred to her as "the ingenious and lively Mrs. Fulhame", but this opinion may reflect the style of her book. Mrs. Fulhame's work began with her interest in finding way of staining cloth with heavy metals under the influence of light, she considered calling her work An Essay on the Art of making Cloths of Gold and other Metals, by chymical processes, but considering the "imperfect state of the art", decided to select a title reflecting the broader implications of her experiments. "The possibility of making cloths of gold and other metals, by chymical processes, occurred to me in the year 1780: the project being mentioned to Doctor Fulhame, some friends, was deemed improbable. However, after some time, I had the satisfaction of realizing the idea, in some degree, by experiment."
She was encouraged to publish an account of her fourteen years of research as a result of meeting Sir Joseph Priestley in 1793. Elizabeth Fulhame studied the experimental reduction of metallic salts in a variety of states by exposing them to the action of various reducing agents; the metal salts she examined included gold, platinum, mercury and tin. As reducing agents, she experimented with hydrogen, phosphorus, potassium sulfide, hydrogen sulfide, phosphine and light, she discovered a number of chemical reactions by. Rayner-Canham considers her most important contribution to chemistry to be the discovery that metals could be processed through aqueous chemical reduction at room temperature, as an alternative to smelting at high temperatures, her theoretical work on catalysis was "a major step in the history of chemistry", predating both Jöns Jakob Berzelius and Eduard Buchner. She proposed, demonstrated through experiment, that many oxidation reactions occur only in the presence of water, that they directly involve water, that water is regenerated and is detectable at the end of the reaction.
Further, she proposed "recognizably modern mechanisms" for those reactions, may have been the first scientist to do so. The role of oxygen, as she describes it, differs from other theories of the time. Based on her experiments, she disagreed with some of the conclusions of Antoine Lavoisier as well as with the phlogiston theorists that he critiqued, her research could seen as a precursor to the work of Jöns Jakob Berzelius, however Fulhame focused on water rather than heavy metals. Further, Schaaf considers her work on silver chemistry to be a landmark in the birth and early history of photography. Fulhame's work on the role of light sensitive chemicals on fabric, predates Thomas Wedgwood's more famous photogram trials of 1801. Fulhame did not, attempt to make "images" or representational shadow prints in the way Wedgwood did, but she did engage in photoreduction using light. In addition to her book being republished in Germany and America, Fulhame's experiments were reviewed in several British magazines, were positively commented on by Sir Benjamin Thompson, Count Rumford, Sir John Herschel.
Nonetheless, her work was lesser known than it could or should have been, according to the introduction of her book by her American editor in 1810. He asserted that "the pride of science, revolted at the idea of being taught by a female". Indeed, Fulhame acknowledges in her own introduction that the possessive climate of science during her historical moment balked at challenges to their "dictatorship in science" by new insight from a woman, as recounted in a book chapter about her as the inventor of catalysis: "But censure is inevitable: for some are so ignorant, that they grow sullen and silent, are chilled with horror at the sight of anything that nears the semblance of learning, in whatever shape it may appear, she describes her book as serving as "a beacon to future mariners" taking up scientific inquiries. Sadly, Antoine Lavoisier was executed six months before the publication of her book and thus could not respond to her theory. Irish chemist William Higgins complained that she had ignored his work on the involvement of wa
Martin Luther University of Halle-Wittenberg
The Martin Luther University of Halle-Wittenberg referred to as MLU, is a public, research-oriented university in the cities of Halle and Wittenberg in Saxony-Anhalt, Germany. MLU offers German and international courses leading to academic degrees such as BA, BSc, MA, MSc, doctoral degrees and Habilitation; the university was created in 1817 through the merger of the University of Wittenberg and the University of Halle. The university is named after the Protestant reformer Martin Luther, a professor in Wittenberg. Today, the university itself is located in Halle, while the Leucorea Foundation in Wittenberg serves as MLU's convention centre for seminars as well as for academic and political conferences. Both Halle and Wittenberg are about one hour from Berlin via the Berlin–Halle railway, which offers Intercity-Express trains; the University of Wittenberg was founded in 1502 by Frederick the Wise, Elector of Saxony, as the Renaissance was becoming more and more popular. The foundation of the university was criticized when the Ninety-five Theses reached Albert of Brandenburg, the Archbishop of Mainz.
Ecclesiastically speaking, the Electorate of Saxony was subordinate to Albert. He criticized the elector for Luther's theses, viewing the founded university as a breeding ground for heretical ideas. Under the influence of Philipp Melanchthon, building on the works of Martin Luther, the university became a centre of the Protestant Reformation incorporating, at one point in time, Luther's house in Wittenberg, the Lutherhaus, as part of the campus. Notable alumni include George Müller, Georg Joachim Rheticus and – in fiction – William Shakespeare's Prince Hamlet and Horatio and Christopher Marlowe's Doctor Faustus; the University of Halle was founded in 1694 by Frederick III, Elector of Brandenburg, who became Frederick I, King in Prussia, in 1701. In the late 17th century and early 18th century, Halle became a centre for Pietism within Prussia. In the 17th and 18th centuries, the universities were centers of the German Enlightenment. Christian Wolff was an important proponent of rationalism, he influenced many German scholars, such as Immanuel Kant.
Christian Thomasius was at the same time the first philosopher in Germany to hold his lectures not in Latin, but German. He contributed to a rational programme in philosophy but tried to establish a more common-sense point of view, aimed against the unquestioned superiority of aristocracy and theology; the institutionalisation of the local language as the language of instruction, the prioritisation of rationalism over religious orthodoxy, new modes of teaching, the ceding of control over their work to the professors themselves, were among various innovations which characterised the University of Halle, have led to its being referred to as the first "modern" university, whose liberalism was adopted by the University of Göttingen about a generation and subsequently by other German and most North American universities. The University of Wittenberg was closed in 1813 during the Napoleonic Wars; the town of Wittenberg was granted to Prussia in the Congress of Vienna in 1815, the university was merged with the Prussian University of Halle in 1817.
It took its present name on 10 November 1933. More than a dozen professors were expelled. Others were shifted to Halle-Wittenberg from universities regarded as "better" at the time, which led to the university being called an academic Vorkuta – after the largest center of the Gulag camps in European Russia). Following the continental European academic tradition, MLU has 9 faculties, regrouping academic staff and students according to their field of studies: Faculty of Theology Faculty of Law and Economics Faculty of Medicine Faculty of Philosophy I Faculty of Philosophy II Faculty of Philosophy III Faculty of Natural Sciences I Faculty of Natural Sciences II Faculty of Natural Sciences III The Botanical Garden of Martin Luther University of Halle-Wittenberg, founded in 1698. MLU's historical observatory, built in 1788 by Carl Gotthard Langhans. MLU is enclosed by a variety of research institutions, which have either institutional or personal links with the university or cooperate in their respective fields of studies: The German Academy of Sciences Leopoldina The Halle Institute for Economic Research The Fraunhofer Institute for Mechanics of Materials The Leibniz Institute of Agricultural Development in Central and Eastern Europe The Leibniz Institute of Plant Biochemistry The Max Planck Research Unit for Enzymology of Protein Folding The Max Planck Institute for Social Anthropology The Max Planck Institute of Microstructure Physics The Helmholtz Centre for Environmental Research Even though MLU is an academic, research oriented institution, not an academy of music or conservatory, the university has an academic orchestra, founded in 1779, a rather prestigious choir, founded in 1950, which together constitute the so-called Collegium musicum.
Members are gifted students of all faculties, but academic staff and alumni. The university choir performs at the international Handel Festival in George Frideric Handel’s birthplace, Halle. MLU has many international partner universities, including: Argentina: National University of La Plata Australia: University of Queensland Austria: Johannes Kepler University Linz Canada: University of Ottawa Colombi
Guillaume François Rouelle was a French chemist and apothecary. In 1754 he introduced the concept of a base into chemistry, as a substance which reacts with an acid to give it solid form, he is known as l'Aîné to distinguish him from his younger brother, Hilaire Rouelle, a chemist and known as the discoverer of urea. He started a public course in his laboratory in 1738 where he taught many students among whom were Denis Diderot, Antoine-Laurent de Lavoisier, Joseph Proust and Antoine-Augustin Parmentier, he was elected a foreign member of the Royal Swedish Academy of Sciences in 1749. Franckowiak, Rémi. "Rouelle, un vrai-faux anti-newtonien". Archives internationales d'histoire des sciences. 53: 240–255. Franckowiak, Rémi. "Les sels neutres de Guillaume-François Rouelle". Revue d'Histoire des Sciences. 55: 493–532. Jensen, William B.. "The origin of the term "base"". The Journal of Chemical Education. 83: 1130. Bibcode:2006JChEd..83.1130J. Doi:10.1021/ed083p1130. Lemay, Pierre. "The lectures of Guillaume Francois Rouelle".
The Journal of Chemical Education. 31: 338. Bibcode:1954JChEd..31..338L. Doi:10.1021/ed031p338. Warolin, C.. "Lavoisier". Histoire des sciences médicales. 30: 30. PMID 11624829. Warolin, C.. "Lavoisier". Revue d'histoire de la pharmacie. 42: 361–367. PMID 11624913
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel and an oxidant atmospheric oxygen, that produces oxidized gaseous products, in a mixture termed as smoke. Combustion in a fire produces a flame, the heat produced can make combustion self-sustaining. Combustion is a complicated sequence of elementary radical reactions. Solid fuels, such as wood and coal, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion supplies the heat required to produce more of them. Combustion is hot enough that incandescent light in the form of either glowing or a flame is produced. A simple example can be seen in the combustion of hydrogen and oxygen into water vapor, a reaction used to fuel rocket engines; this reaction releases 242 kJ/mol of heat and reduces the enthalpy accordingly: 2H2 + O2 → 2H2OCombustion of an organic fuel in air is always exothermic because the double bond in O2 is much weaker than other double bonds or pairs of single bonds, therefore the formation of the stronger bonds in the combustion products CO2 and H2O results in the release of energy.
The bond energies in the fuel play only a minor role, since they are similar to those in the combustion products. The heat of combustion is -418 kJ per mole of O2 used up in the combustion reaction, can be estimated from the elemental composition of the fuel. Uncatalyzed combustion in air requires high temperatures. Complete combustion is stoichiometric with respect to the fuel, where there is no remaining fuel, ideally, no remaining oxidant. Thermodynamically, the chemical equilibrium of combustion in air is overwhelmingly on the side of the products. However, complete combustion is impossible to achieve, since the chemical equilibrium is not reached, or may contain unburnt products such as carbon monoxide and carbon. Thus, the produced smoke is toxic and contains unburned or oxidized products. Any combustion at high temperatures in atmospheric air, 78 percent nitrogen, will create small amounts of several nitrogen oxides referred to as NO x, since the combustion of nitrogen is thermodynamically favored at high, but not low temperatures.
Since combustion is clean, flue gas cleaning or catalytic converters may be required by law. Fires occur ignited by lightning strikes or by volcanic products. Combustion was the first controlled chemical reaction discovered by humans, in the form of campfires and bonfires, continues to be the main method to produce energy for humanity; the fuel is carbon, hydrocarbons or more complicated mixtures such as wood that contains oxidized hydrocarbons. The thermal energy produced from combustion of either fossil fuels such as coal or oil, or from renewable fuels such as firewood, is harvested for diverse uses such as cooking, production of electricity or industrial or domestic heating. Combustion is currently the only reaction used to power rockets. Combustion is used to destroy waste, both nonhazardous and hazardous. Oxidants for combustion have high oxidation potential and include atmospheric or pure oxygen, fluorine, chlorine trifluoride, nitrous oxide and nitric acid. For instance, hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat and light characteristic of combustion.
Although not catalyzed, combustion can be catalyzed by platinum or vanadium, as in the contact process. In complete combustion, the reactant burns in oxygen, produces a limited number of products; when a hydrocarbon burns in oxygen, the reaction will yield carbon dioxide and water. When elements are burned, the products are the most common oxides. Carbon will yield carbon dioxide, sulfur will yield sulfur dioxide, iron will yield iron oxide. Nitrogen is not considered to be a combustible substance when oxygen is the oxidant, but small amounts of various nitrogen oxides form when the air is the oxidant. Combustion is not favorable to the maximum degree of oxidation, it can be temperature-dependent. For example, sulfur trioxide is not produced quantitatively by the combustion of sulfur. NOx species appear in significant amounts above about 2,800 °F, more is produced at higher temperatures; the amount of NOx is a function of oxygen excess. In most industrial applications and in fires, air is the source of oxygen.
In the air, each mole of oxygen is mixed with 3.71 mol of nitrogen. Nitrogen does not take part in combustion, but at high temperatures some nitrogen will be converted to NOx. On the other hand, when there is insufficient oxygen to combust the fuel, some fuel carbon is converted to carbon monoxide and some of the hydrogen remains unreacted. A more complete set of equations for the combustion of a hydrocarbon in the air, requires an additional calculation for the distribution of oxygen between the carbon and hydrogen in the fuel; the amount of air required for complete combustion to take place is known as theoretical air. However, in practice, the air used is 2-3x. Incomplete combustion will occur when there is not enough oxygen to allow the fuel to react to produce carbon dioxide and water, it happens when the combustion is quenched by a heat sink, such as a solid surface or flame trap. Same as complete combustion, water is produced by incomplete combustion. However, carbon monoxide, and/or hydroxide are the products in
Antoine-Laurent de Lavoisier was a French nobleman and chemist, central to the 18th-century chemical revolution and who had a large influence on both the history of chemistry and the history of biology. He is considered in popular literature as the "father of modern chemistry", it is accepted that Lavoisier's great accomplishments in chemistry stem from his changing the science from a qualitative to a quantitative one. Lavoisier is most noted, he opposed the phlogiston theory. Lavoisier helped construct the metric system, wrote the first extensive list of elements, helped to reform chemical nomenclature, he predicted the existence of silicon and was the first to establish that sulfur was an element rather than a compound. He discovered that, although matter may change its shape, its mass always remains the same. Lavoisier was a powerful member of a number of aristocratic councils, an administrator of the Ferme générale; the Ferme générale was one of the most hated components of the Ancien Régime because of the profits it took at the expense of the state, the secrecy of the terms of its contracts, the violence of its armed agents.
All of these political and economic activities enabled him to fund his scientific research. At the height of the French Revolution, he was charged with tax fraud and selling adulterated tobacco, was guillotined. Antoine-Laurent Lavoisier was born to a wealthy family of the nobility in Paris on 26 August 1743; the son of an attorney at the Parliament of Paris, he inherited a large fortune at the age of five upon the death of his mother. Lavoisier began his schooling at the Collège des Quatre-Nations, University of Paris in Paris in 1754 at the age of 11. In his last two years at the school, his scientific interests were aroused, he studied chemistry, botany and mathematics. In the philosophy class he came under the tutelage of Abbé Nicolas Louis de Lacaille, a distinguished mathematician and observational astronomer who imbued the young Lavoisier with an interest in meteorological observation, an enthusiasm which never left him. Lavoisier entered the school of law, where he received a bachelor's degree in 1763 and a licentiate in 1764.
Lavoisier was admitted to the bar, but never practiced as a lawyer. However, he continued his scientific education in his spare time. Lavoisier's education was filled with the ideals of the French Enlightenment of the time, he was fascinated by Pierre Macquer's dictionary of chemistry, he attended. Lavoisier's devotion and passion for chemistry were influenced by Étienne Condillac, a prominent French scholar of the 18th century, his first chemical publication appeared in 1764. From 1763 to 1767, he studied geology under Jean-Étienne Guettard. In collaboration with Guettard, Lavoisier worked on a geological survey of Alsace-Lorraine in June 1767. In 1764 he read his first paper to the French Academy of Sciences, France's most elite scientific society, on the chemical and physical properties of gypsum, in 1766 he was awarded a gold medal by the King for an essay on the problems of urban street lighting. In 1768 Lavoisier received a provisional appointment to the Academy of Sciences. In 1769, he worked on the first geological map of France.
While Lavoisier is known for his contributions to the sciences, he dedicated a significant portion of his fortune and work toward benefitting the public. Lavoisier was a humanitarian—he cared about the people in his country and concerned himself with improving the livelihood of the population by agriculture and the sciences; the first instance of this occurred in 1765, when he submitted an essay on improving urban street lighting to the French Academy of Sciences. Three years in 1768, he focused on a new project to design an aqueduct; the goal was to bring in water from the river Yvette into Paris so that the citizens could have clean drinking water. But, since the construction never commenced, he instead turned his focus to purifying the water from the Seine; this was the project that interested Lavoisier in the chemistry of water and public sanitation duties. He additionally was interested in air quality, spent some time studying the health risks associated with gunpowder's effect on the air.
In 1772, he performed a study on how to reconstruct the Hôtel-Dieu hospital, after it had been damaged by fire, in a way that would allow proper ventilation and clean air throughout. At the time, the prisons in Paris were known to be unlivable and the prisoners’ treatment inhumane. Lavoisier took part in investigations in 1780 on the hygiene in prisons and had made suggestions to improve living conditions, which were ignored. Once a part of the Academy, Lavoisier held his own competitions to push the direction of research towards bettering the public and his own work. One such project he proposed in 1793 was to better public health on the “insalubrious arts.” Lavoisier had a vision of public education having roots in “scientific sociability” and philanthropy. Lavoisier gained a vast majority of his income through buying stock in the General Farm, which allowed him to work on science full-time, live comfortably, allowed him to contribute financially to better the community, it was difficult to secure public funding for the sciences at the time, additionally not ver
OCLC Online Computer Library Center, Incorporated d/b/a OCLC is an American nonprofit cooperative organization "dedicated to the public purposes of furthering access to the world's information and reducing information costs". It was founded in 1967 as the Ohio College Library Center. OCLC and its member libraries cooperatively produce and maintain WorldCat, the largest online public access catalog in the world. OCLC is funded by the fees that libraries have to pay for its services. OCLC maintains the Dewey Decimal Classification system. OCLC began in 1967, as the Ohio College Library Center, through a collaboration of university presidents, vice presidents, library directors who wanted to create a cooperative computerized network for libraries in the state of Ohio; the group first met on July 5, 1967 on the campus of the Ohio State University to sign the articles of incorporation for the nonprofit organization, hired Frederick G. Kilgour, a former Yale University medical school librarian, to design the shared cataloging system.
Kilgour wished to merge the latest information storage and retrieval system of the time, the computer, with the oldest, the library. The plan was to merge the catalogs of Ohio libraries electronically through a computer network and database to streamline operations, control costs, increase efficiency in library management, bringing libraries together to cooperatively keep track of the world's information in order to best serve researchers and scholars; the first library to do online cataloging through OCLC was the Alden Library at Ohio University on August 26, 1971. This was the first online cataloging by any library worldwide. Membership in OCLC is based on use of services and contribution of data. Between 1967 and 1977, OCLC membership was limited to institutions in Ohio, but in 1978, a new governance structure was established that allowed institutions from other states to join. In 2002, the governance structure was again modified to accommodate participation from outside the United States.
As OCLC expanded services in the United States outside Ohio, it relied on establishing strategic partnerships with "networks", organizations that provided training and marketing services. By 2008, there were 15 independent United States regional service providers. OCLC networks played a key role in OCLC governance, with networks electing delegates to serve on the OCLC Members Council. During 2008, OCLC commissioned two studies to look at distribution channels. In early 2009, OCLC negotiated new contracts with the former networks and opened a centralized support center. OCLC provides bibliographic and full-text information to anyone. OCLC and its member libraries cooperatively produce and maintain WorldCat—the OCLC Online Union Catalog, the largest online public access catalog in the world. WorldCat has holding records from private libraries worldwide; the Open WorldCat program, launched in late 2003, exposed a subset of WorldCat records to Web users via popular Internet search and bookselling sites.
In October 2005, the OCLC technical staff began a wiki project, WikiD, allowing readers to add commentary and structured-field information associated with any WorldCat record. WikiD was phased out; the Online Computer Library Center acquired the trademark and copyrights associated with the Dewey Decimal Classification System when it bought Forest Press in 1988. A browser for books with their Dewey Decimal Classifications was available until July 2013; until August 2009, when it was sold to Backstage Library Works, OCLC owned a preservation microfilm and digitization operation called the OCLC Preservation Service Center, with its principal office in Bethlehem, Pennsylvania. The reference management service QuestionPoint provides libraries with tools to communicate with users; this around-the-clock reference service is provided by a cooperative of participating global libraries. Starting in 1971, OCLC produced catalog cards for members alongside its shared online catalog. OCLC commercially sells software, such as CONTENTdm for managing digital collections.
It offers the bibliographic discovery system WorldCat Discovery, which allows for library patrons to use a single search interface to access an institution's catalog, database subscriptions and more. OCLC has been conducting research for the library community for more than 30 years. In accordance with its mission, OCLC makes its research outcomes known through various publications; these publications, including journal articles, reports and presentations, are available through the organization's website. OCLC Publications – Research articles from various journals including Code4Lib Journal, OCLC Research, Reference & User Services Quarterly, College & Research Libraries News, Art Libraries Journal, National Education Association Newsletter; the most recent publications are displayed first, all archived resources, starting in 1970, are available. Membership Reports – A number of significant reports on topics ranging from virtual reference in libraries to perceptions about library funding. Newsletters – Current and archived newsletters for the library and archive community.
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