Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the royal academies of Sweden. It is an independent, non-governmental scientific organisation which takes special responsibility for the natural sciences and mathematics, but endeavours to promote the exchange of ideas between various disciplines, its purpose is to. Nobel Prizes in Physics and in Chemistry Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel Crafoord Prizes in astronomy and mathematics, geosciences and polyarthritis Sjöberg Prize Rolf Schock Prizes in logic and philosophy Gregori Aminoff Prize in crystallography Tobias Prize Göran Gustafsson Prize for research in mathematics, the natural sciences and medicine Söderberg Prize in economics or jurisprudence Ingvar Lindqvist Prizes for teachers in the fields of physics, chemistry and mathematics. Etc; the academy has elected about 1,700 Swedish and 1,200 foreign members since it was founded in 1739. Today the academy has about 470 Swedish and 175 foreign members which are divided into ten "classes", representing ten various scientific disciplines: Mathematics Astronomy and space science Physics Chemistry Geosciences Biosciences Medical sciences Engineering sciences Social sciences Humanities and for outstanding services to science The following persons have served as permanent secretaries of the academy: Anders Johan von Höpken, 1739–1740, 1740–1741 Augustin Ehrensvärd, April – June 1740 Jacob Faggot, 1741–1744 Pehr Elvius, 1744–1749 Pehr Wilhelm Wargentin, 1749–1783 Johan Carl Wilcke and Henrik Nicander, 1784–1796 Daniel Melanderhjelm and Henrik Nicander, 1796–1803 Jöns Svanberg and Carl Gustaf Sjöstén 1803–1808.
In parallel, other major series have appeared and gone: Öfversigt af Kungl. Vetenskapsakademiens förhandlingar Bihang till Vetenskapsakademiens Handlingar Vetenskapsakademiens årsbok The academy started publishing annual reports in physics and chemistry, technology and zoology; these lasted into the 1860s. Starting in 1887, this series was once again split into four sections, which in 1903 became independent scientific journals of their own, titled "Arkiv för...", among them Arkiv för matematik, astronomi och fysik. Further restructuring of their topics occurred in 1949 and 1974. Current publicationsAmbio Acta Mathematica Arkiv för matematik Acta Zoologica Levnadsteckningar över Vetenskapsakademiens ledamöter, biographies of deceased members Porträttmatrikel, portraits of current members Zoologica Scripta, jointly with the Norwegian Academy of Science and Letters The academy was founded on 2 June 1739 by naturalist Carl Linnaeus, mercantilist Jonas Alströmer, mechanical engineer Mårten Triewald, civil servants Sten Carl Bielke and Carl Wilhelm Cederhielm, statesman/author Anders Johan von Höpken.
The purpose of the academy was to focus on useful knowledge, to publish in Swedish in order to disseminate the academy's findings. The academy was intended to be different from the Royal Society of Sciences in Uppsala, founded in 1719 and published in Latin; the location close to the commercial activities in Sweden's capital was intentional. The academy was modeled after the Royal Society of London and Academie Royale des Sciences in Paris, which some of the founding members were familiar with. Members of the Royal Swedish Academy of Sciences Official website Royal Swedish Academy of Sciences video site
Smelting is a process of applying heat to ore in order to extract out a base metal. It is a form of extractive metallurgy, it is used to extract many metals from their ores, including silver, iron and other base metals. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal base behind; the reducing agent is a source of carbon, such as coke—or, in earlier times, charcoal. The carbon removes oxygen from the ore; the carbon thus oxidizes in two stages, producing first carbon monoxide and carbon dioxide. As most ores are impure, it is necessary to use flux, such as limestone, to remove the accompanying rock gangue as slag. Plants for the electrolytic reduction of aluminium are generally referred to as aluminium smelters. Labourers working in the smelting industry have reported respiratory illnesses inhibiting their ability to perform the physical tasks demanded by their jobs. Smelting involves more than just melting the metal out of its ore.
Most ores are the chemical compound of the metal and other elements, such as oxygen, sulfur, or carbon and oxygen together. To extract the metal, workers must make these compounds undergo a chemical reaction. Smelting therefore consists of using suitable reducing substances that combine with those oxidizing elements to free the metal. In the case of carbonates and sulfides, a process called "roasting" drives out the unwanted carbon or sulfur, leaving an oxide, which can be directly reduced. Roasting is carried out in an oxidizing environment. A few practical examples: Malachite, a common ore of copper, is copper carbonate hydroxide Cu22; this mineral undergoes thermal decomposition to 2CuO, CO2, H2O in several stages between 250 °C and 350 °C. The carbon dioxide and water are expelled into the atmosphere, leaving copper oxide, which can be directly reduced to copper as described in the following section titled Reduction. Galena, the most common mineral of lead, is lead sulfide; the sulfide is oxidized to a sulfite, which thermally decomposes into lead oxide and sulfur dioxide gas.
The sulfur dioxide is expelled, the lead oxide is reduced as below. Reduction is the final, high-temperature step in smelting, in which the oxide becomes the elemental metal. A reducing environment pulls the final oxygen atoms from the raw metal; the required temperature varies over a large range, both in absolute terms and in terms of the melting point of the base metal. Examples: Iron oxide becomes metallic iron at 1250 °C 300 degrees below iron's melting point of 1538 °C. Mercuric oxide becomes vaporous mercury near 550 °C 600 degrees above mercury's melting point of -38 °C. Flux and slag can provide a secondary service after the reduction step is complete: they provide a molten cover on the purified metal, preventing contact with oxygen while still hot enough to oxidize; this prevents impurities from forming in the metal. Metal workers use fluxes in smelting for several purposes, chief among them catalyzing the desired reactions and chemically binding to unwanted impurities or reaction products.
Calcium oxide, in the form of lime, was used for this purpose, since it could react with the carbon dioxide and sulfur dioxide produced during roasting and smelting to keep them out of the working environment. Of the seven metals known in antiquity, only gold occurred in native form in the natural environment; the others – copper, silver, tin and mercury – occur as minerals, though copper is found in its native state in commercially significant quantities. These minerals are carbonates, sulfides, or oxides of the metal, mixed with other components such as silica and alumina. Roasting the carbonate and sulfide minerals in air converts them to oxides; the oxides, in turn, are smelted into the metal. Carbon monoxide was the reducing agent of choice for smelting, it is produced during the heating process, as a gas comes into intimate contact with the ore. In the Old World, humans learned to smelt metals in prehistoric times, more than 8000 years ago; the discovery and use of the "useful" metals — copper and bronze at first iron a few millennia — had an enormous impact on human society.
The impact was so pervasive that scholars traditionally divide ancient history into Stone Age, Bronze Age, Iron Age. In the Americas, pre-Inca civilizations of the central Andes in Peru had mastered the smelting of copper and silver at least six centuries before the first Europeans arrived in the 16th century, while never mastering the smelting of metals such as iron for use with weapon-craft. In the Old World, the first metals smelted were lead; the earliest known cast lead beads were found in the Çatal Höyük site in Anatolia, dated from about 6500 BC, but the metal may have been known earlier. Since the discovery happened several millennia before the invention of writing, there is no written record about how it was made; however and lead can be smelted by placing the ores in a wood fire, leaving the possibility that the discovery may have occurred by accident. Lead is a common metal, but its discovery had little impact in the ancient world, it is too soft to use for structural elements or weapons, though its high density relative to other metals makes it ideal for sling projectiles.
However, since it was
Chemistry is the scientific discipline involved with elements and compounds composed of atoms and ions: their composition, properties and the changes they undergo during a reaction with other substances. In the scope of its subject, chemistry occupies an intermediate position between physics and biology, it is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant chemistry, the formation of igneous rocks, how atmospheric ozone is formed and how environmental pollutants are degraded, the properties of the soil on the moon, how medications work, how to collect DNA evidence at a crime scene. Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds. There are four types of chemical bonds: covalent bonds, in which compounds share one or more electron; the word chemistry comes from alchemy, which referred to an earlier set of practices that encompassed elements of chemistry, philosophy, astronomy and medicine.
It is seen as linked to the quest to turn lead or another common starting material into gold, though in ancient times the study encompassed many of the questions of modern chemistry being defined as the study of the composition of waters, growth, disembodying, drawing the spirits from bodies and bonding the spirits within bodies by the early 4th century Greek-Egyptian alchemist Zosimos. An alchemist was called a'chemist' in popular speech, the suffix "-ry" was added to this to describe the art of the chemist as "chemistry"; the modern word alchemy in turn is derived from the Arabic word al-kīmīā. In origin, the term is borrowed from the Greek χημία or χημεία; this may have Egyptian origins since al-kīmīā is derived from the Greek χημία, in turn derived from the word Kemet, the ancient name of Egypt in the Egyptian language. Alternately, al-kīmīā may derive from χημεία, meaning "cast together"; the current model of atomic structure is the quantum mechanical model. Traditional chemistry starts with the study of elementary particles, molecules, metals and other aggregates of matter.
This matter can be studied in isolation or in combination. The interactions and transformations that are studied in chemistry are the result of interactions between atoms, leading to rearrangements of the chemical bonds which hold atoms together; such behaviors are studied in a chemistry laboratory. The chemistry laboratory stereotypically uses various forms of laboratory glassware; however glassware is not central to chemistry, a great deal of experimental chemistry is done without it. A chemical reaction is a transformation of some substances into one or more different substances; the basis of such a chemical transformation is the rearrangement of electrons in the chemical bonds between atoms. It can be symbolically depicted through a chemical equation, which involves atoms as subjects; the number of atoms on the left and the right in the equation for a chemical transformation is equal. The type of chemical reactions a substance may undergo and the energy changes that may accompany it are constrained by certain basic rules, known as chemical laws.
Energy and entropy considerations are invariably important in all chemical studies. Chemical substances are classified in terms of their structure, phase, as well as their chemical compositions, they can be analyzed using the tools of e.g. spectroscopy and chromatography. Scientists engaged in chemical research are known as chemists. Most chemists specialize in one or more sub-disciplines. Several concepts are essential for the study of chemistry; the particles that make up matter have rest mass as well – not all particles have rest mass, such as the photon. Matter can be a mixture of substances; the atom is the basic unit of chemistry. It consists of a dense core called the atomic nucleus surrounded by a space occupied by an electron cloud; the nucleus is made up of positively charged protons and uncharged neutrons, while the electron cloud consists of negatively charged electrons which orbit the nucleus. In a neutral atom, the negatively charged electrons balance out the positive charge of the protons.
The nucleus is dense. The atom is the smallest entity that can be envisaged to retain the chemical properties of the element, such as electronegativity, ionization potential, preferred oxidation state, coordination number, preferred types of bonds to form. A chemical element is a pure substance, composed of a single type of atom, characterized by its particular number of protons in the nuclei of its atoms, known as the atomic number and represented by the symbol Z; the mass number is the sum of the number of neutrons in a nucleus. Although all the nuclei of all atoms belonging to one element will have the same
Uppsala is the capital of Uppsala County and the fourth-largest city in Sweden, after Stockholm and Malmö. It had 168,096 inhabitants in 2017. Located 71 km north of the capital Stockholm it is the seat of Uppsala Municipality. Since 1164, Uppsala has been the ecclesiastical centre of Sweden, being the seat of the Archbishop of the Church of Sweden. Uppsala is home to Scandinavia's largest cathedral – Uppsala Cathedral. Founded in 1477, Uppsala University is the oldest centre of higher education in Scandinavia. Among many achievements, the Celsius scale for temperature was invented there. Uppsala was located a few kilometres north of its current location at a place now known as Gamla Uppsala. Today's Uppsala was called Östra Aros. Uppsala was, according to medieval writer Adam of Bremen, the main pagan centre of Sweden, the Temple at Uppsala contained magnificent idols of the Norse gods; the Fyrisvellir plains along the river south of Old Uppsala, in the area where the modern city is situated today, was the site of the Battle of Fyrisvellir in the 980s.
The present-day Uppsala was a port town of Gamla Uppsala. In 1160, King Eric Jedvardsson was attacked and killed outside the church of Östra Aros, became venerated as a saint in the Catholic Church. In 1274, Östra Aros overtook Gamla Uppsala as the main regional centre, when the cathedral of Gamla Uppsala burnt down, the archbishopric and the relics of Saint Eric were moved to Östra Aros, where the present-day Uppsala Cathedral was erected; the cathedral is built in the Gothic style and is one of the largest in northern Europe, with towers reaching 118.70 metres. The city is the site of the oldest university in Scandinavia, founded in 1477, is where Carl Linnaeus, one of the renowned scholars of Uppsala University, lived for many years. Uppsala is the site of the 16th-century Uppsala Castle; the city was damaged by a fire in 1702. Historical and cultural treasures were lost, as in many Swedish cities, from demolitions during the 1960s and 1970s, but many historic buildings remain in the western part of the city.
The arms bearing the lion can be traced to 1737 and have been modernised several times, most in 1986. The meaning of the lion is uncertain, but is connected to the royal lion depicted on the Coat of Arms of Sweden. Situated on the fertile Uppsala flatlands of muddy soil, the city features the small Fyris River flowing through the landscape surrounded by lush vegetation. Parallel to the river runs the glacial ridge of Uppsalaåsen at an elevation around 30 m, the site of Uppsala's castle, from which large parts of the town can be seen; the central park Stadsskogen stretches from the south far into town, with opportunities for recreation for many residential areas within walking distance. Only some 70 km or 40 minutes by train from the capital, many Uppsala residents work in Stockholm; the train to Stockholm-Arlanda Airport takes only 17 minutes, rendering the city accessible by air. The commercial centre of Uppsala is quite compact; the city has a distinct town and gown divide with clergy and academia residing in the Fjärdingen neighbourhood on the river's western shore, somewhat separated from the rest of the city, the ensemble of cathedral and university buildings has remained undisturbed until today.
While some historic buildings remain on the periphery of the central core, retail commercial activity is geographically focused on a small number of blocks around the pedestrianized streets and main square on the eastern side of the river, an area, subject to a large-scale metamorphosis during the economically booming years in the 1960s in particular. During recent decades, a significant part of retail commercial activity has shifted to shopping malls and stores situated in the outskirts of the city. Meanwhile, the built-up areas have expanded and some suburbanization has taken place. Uppsala lies south of the 60th parallel north and has a humid continental climate, with cold winters and warm summers. Due to its northerly location, Uppsala experiences over 18 hours of visible sunshine during the summer solstice, under 6 hours of sunshine during the winter solstice. Despite Uppsala's northerly location, the winter is not as cold as other cities at similar latitudes due to the Gulf Stream. For example, in January Uppsala has a daily mean of −2.7 °C.
In Canada, at the same latitude, Fort Smith experiences a daily mean of −22.4 °C. With respect to record temperatures, the difference between the highest and lowest is large. Uppsala’s highest recorded temperature was 37.4 °C, recorded in July 1933. On the same day Ultuna, which lies a few kilometres south of the centre of Uppsala, recorded a temperature of 38 °C; this is the highest temperature recorded in the Scandinavian Peninsula, although the same temperature was recorded in Målilla, Sweden, 14 years later. Uppsala’s lowest temperature was recorded in January 1875, when the temperature dropped to −39.5 °C. The second-lowest temperature recorded is −33.1 °C, which makes the record one of the hardest to beat, due to the fact that temperatures in Uppsala nowadays goes below −30 °C. The difference between the two records is 76.9 °C. The warmest month recorded is July 1914, with a daily mean of 21.4 °C. Since 2002 Uppsala has experienced 5 months where the d
Carbon is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds, it belongs to group 14 of the periodic table. Three isotopes occur 12C and 13C being stable, while 14C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the few elements known since antiquity. Carbon is the 15th most abundant element in the Earth's crust, the fourth most abundant element in the universe by mass after hydrogen and oxygen. Carbon's abundance, its unique diversity of organic compounds, its unusual ability to form polymers at the temperatures encountered on Earth enables this element to serve as a common element of all known life, it is the second most abundant element in the human body by mass after oxygen. The atoms of carbon can bond together in different ways, termed allotropes of carbon; the best known are graphite and amorphous carbon. The physical properties of carbon vary with the allotropic form.
For example, graphite is opaque and black while diamond is transparent. Graphite is soft enough to form a streak on paper, while diamond is the hardest occurring material known. Graphite is a good electrical conductor. Under normal conditions, carbon nanotubes, graphene have the highest thermal conductivities of all known materials. All carbon allotropes are solids under normal conditions, with graphite being the most thermodynamically stable form at standard temperature and pressure, they are chemically resistant and require high temperature to react with oxygen. The most common oxidation state of carbon in inorganic compounds is +4, while +2 is found in carbon monoxide and transition metal carbonyl complexes; the largest sources of inorganic carbon are limestones and carbon dioxide, but significant quantities occur in organic deposits of coal, peat and methane clathrates. Carbon forms a vast number of compounds, more than any other element, with ten million compounds described to date, yet that number is but a fraction of the number of theoretically possible compounds under standard conditions.
For this reason, carbon has been referred to as the "king of the elements". The allotropes of carbon include graphite, one of the softest known substances, diamond, the hardest occurring substance, it bonds with other small atoms, including other carbon atoms, is capable of forming multiple stable covalent bonds with suitable multivalent atoms. Carbon is known to form ten million different compounds, a large majority of all chemical compounds. Carbon has the highest sublimation point of all elements. At atmospheric pressure it has no melting point, as its triple point is at 10.8±0.2 MPa and 4,600 ± 300 K, so it sublimes at about 3,900 K. Graphite is much more reactive than diamond at standard conditions, despite being more thermodynamically stable, as its delocalised pi system is much more vulnerable to attack. For example, graphite can be oxidised by hot concentrated nitric acid at standard conditions to mellitic acid, C66, which preserves the hexagonal units of graphite while breaking up the larger structure.
Carbon sublimes in a carbon arc, which has a temperature of about 5800 K. Thus, irrespective of its allotropic form, carbon remains solid at higher temperatures than the highest-melting-point metals such as tungsten or rhenium. Although thermodynamically prone to oxidation, carbon resists oxidation more than elements such as iron and copper, which are weaker reducing agents at room temperature. Carbon is the sixth element, with a ground-state electron configuration of 1s22s22p2, of which the four outer electrons are valence electrons, its first four ionisation energies, 1086.5, 2352.6, 4620.5 and 6222.7 kJ/mol, are much higher than those of the heavier group-14 elements. The electronegativity of carbon is 2.5 higher than the heavier group-14 elements, but close to most of the nearby nonmetals, as well as some of the second- and third-row transition metals. Carbon's covalent radii are taken as 77.2 pm, 66.7 pm and 60.3 pm, although these may vary depending on coordination number and what the carbon is bonded to.
In general, covalent radius decreases with higher bond order. Carbon compounds form the basis of all known life on Earth, the carbon–nitrogen cycle provides some of the energy produced by the Sun and other stars. Although it forms an extraordinary variety of compounds, most forms of carbon are comparatively unreactive under normal conditions. At standard temperature and pressure, it resists all but the strongest oxidizers, it does not react with hydrochloric acid, chlorine or any alkalis. At elevated temperatures, carbon reacts with oxygen to form carbon oxides and will rob oxygen from metal oxides to leave the elemental metal; this exothermic reaction is used in the iron and steel industry to smelt iron and to control the carbon content of steel: Fe3O4 + 4 C → 3 Fe + 4 COCarbon monoxide can be recycled to smelt more iron: Fe3O4 + 4 CO → 3 Fe + 4 CO2with sulfur to form carbon disulfide and with steam in the coal-gas reaction: C + H2O → CO + H2. Carbon combines with some metals at high temperatures to form metallic carbides, such as the iron carbide cementite in steel and tungsten carbide used as an abrasive and for making hard tips for cutting tools.
The system of carbon allotropes spans a range of extremes: Atomic carbon is a ver
Gahnite, ZnAl2O4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, yellow, brown or grey, it forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia. Other occurrences include Falun, Sweden where it is found in pegmatites and skarns, Massachusetts, it was first described in 1807 for an occurrence in the Falu mine, Dalarna and named after the Swedish chemist, Johan Gottlieb Gahn, the discoverer of the element manganese. It is sometimes called zinc spinel