|
Serena DeBeer
Serena DeBeer (born 1973) is an American chemist. She is currently a W3-Professor and the director at the Max Planck Institute for Chemical Energy Conversion in Muelheim an der Ruhr, Germany, where she heads the Department of Inorganic Spectroscopy. Her expertise lies in the application and development of X-ray based spectroscopic methods as probes of electronic structure in biological and chemical catalysis. Education and career Serena DeBeer studied at Southwestern University, Georgetown, TX (USA) where she completed her bachelor program in Chemistry, with minor in Mathematics in 1995 (with honors). She received her doctorate from Stanford University in 2002, working under the guidance of Edward I. Solomon and Keith O. Hodgson. She then moved to SLAC National Accelerator Laboratory, where she worked first as a beamline scientist (2001–2003) at the Stanford Synchrotron Radiation Laboratory, and later as staff scientist (2003–2009). In the Fall of 2009, she relocated to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a Chemical reaction, reaction with other Chemical substance, substances. Chemistry also addresses the nature of chemical bonds in chemical compounds. 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 research, basic and Applied science, applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FeMoco
FeMoco ( cofactor) is the primary cofactor of nitrogenase. Nitrogenase is the enzyme that catalyzes the conversion of atmospheric nitrogen molecules N2 into ammonia (NH3) through the process known as nitrogen fixation. Containing iron and molybdenum, the cofactor is called FeMoco. Its stoichiometry is Fe7MoS9C. Structure The FeMo cofactor is a cluster with composition Fe7MoS9C. Fe is the chemical symbol for the element iron (ferrum), and Mo is the symbol for molybdenum. This large cluster can be viewed as two subunits composed of one Fe4S3 (iron(III) sulfide) cluster and one MoFe3S3 cluster. The two clusters are linked by three sulfide ligands. The unique iron (Fe) is anchored to the protein by a cysteine. It is also bound to three sulfides, resulting in tetrahedral molecular geometry. The additional six Fe centers in the cluster are each bonded to three sulfides. These six internal Fe centers define a trigonal prismatic arrangement around a central carbide center. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogenase
Nitrogenases are enzymes () that are produced by certain bacteria, such as cyanobacteria (blue-green bacteria) and rhizobacteria. These enzymes are responsible for the Organic redox reaction, reduction of nitrogen (N2) to ammonia (NH3). Nitrogenases are the only family of enzymes known to catalyze this reaction, which is a key step in the process of nitrogen fixation. Nitrogen fixation is required for all forms of life, with nitrogen being essential for the biosynthesis of molecules (nucleotides, amino acids) that create plants, animals and other organisms. They are encoded by the Nif genes or Homologous chromosome, homologs. They are related to protochlorophyllide reductase. Classification and structure Although the equilibrium formation of ammonia from molecular hydrogen and nitrogen has an overall negative enthalpy of reaction ( \Delta H^ = -45.2 \ \mathrm \, \mathrm \; \mathrm ), the activation energy is very high ( E_\mathrm = 230-420 \ \mathrm \, \mathrm ). Nitrogenase a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and Diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Although common in nature—both terrestrially and in the outer planets of the Solar System—and in wide use, ammonia is both caust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmholtz-Zentrum Berlin
Helmholtz-Zentrum Berlin für Materialien und Energie (Helmholtz Centre for Materials and Energy, HZB) is part of the Helmholtz Association of German Research Centres. The institute studies the structure and dynamics of materials and investigates solar cell technology. It also runs the third-generation BESSY II synchrotron in Adlershof. Until the end of 2019 it ran the 10 megawatt BER II nuclear research reactor at the Lise Meitner campus in Wannsee. History Following the renaming of Hahn-Meitner-Institut Berlin GmbH to Helmholtz-Zentrum Berlin für Materialien und Energie GmbH on 5 June 2008, the legal merger of Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung (BESSY) with HZB became visible on 1 January 2009. The Hahn-Meitner-Institut Berlin für Kernforschung (HMI), named after Otto Hahn and Lise Meitner, was named 14 March 1959 in Berlin-Wannsee to operate the BER I research reactor that began operation with 50 kW on 24 July 1958, then named Institu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assistant Professor
Assistant Professor is an academic rank just below the rank of an associate professor used in universities or colleges, mainly in the United States and Canada. Overview This position is generally taken after earning a doctoral degree and generally after several years of holding one or more Postdoctoral Researcher positions. It is below the position of Associate Professor at most universities and is equivalent to the rank of Lecturer at most Commonwealth universities. In the United States, Assistant Professor is often the first position held in a tenure track, although it can also be a non-tenure track position. A typical professorship sequence is Assistant Professor, Associate Professor, and Full Professor in order. After 7 years, if successful, Assistant Professors can get tenure and also get promotion to Associate Professor. There is high demand for vacant tenure-track Assistant Professor positions, often with hundreds of applicants. Less than 20% of doctoral graduates move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ithaca, New York
Ithaca is a city in the Finger Lakes region of New York, United States. Situated on the southern shore of Cayuga Lake, Ithaca is the seat of Tompkins County and the largest community in the Ithaca metropolitan statistical area. It is named after the Greek island of Ithaca. A college town, Ithaca is home to Cornell University and Ithaca College. Nearby is Tompkins Cortland Community College (TC3). These three colleges bring thousands of students to the area, who increase Ithaca's seasonal population during the school year. As of 2020, the city's population was 32,108. History Early history Native Americans lived in this area for thousands of years. When reached by Europeans, this area was controlled by the Cayuga tribe of Indians, one of the Five Nations of the ''Haudenosaunee'' or Iroquois League. Jesuit missionaries from New France (Quebec) are said to have had a mission to convert the Cayuga as early as 1657. Saponi and Tutelo peoples, Siouan-speaking tribes, lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SLAC National Accelerator Laboratory
SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center, is a United States Department of Energy National Laboratories, United States Department of Energy National Laboratory operated by Stanford University under the programmatic direction of the U.S. Department of Energy Office of Science and located in Menlo Park, California. It is the site of the Stanford Linear Accelerator, a 3.2 kilometer (2-mile) linear accelerator constructed in 1966 and shut down in the 2000s, that could accelerate electrons to energies of 50 GeV. Today SLAC research centers on a broad program in Atomic physics, atomic and solid state physics, solid-state physics, chemistry, biology, and medicine using X-rays from synchrotron radiation and a free-electron laser as well as experimental physics, experimental and theoretical physics, theoretical research in elementary particle, elementary particle physics, astroparticle physics, and cosmology. History Founde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keith Hodgson
Keith O. Hodgson (born 1947 in Virginia) is a Professor of Chemistry at Stanford University and formerly director of the Stanford Synchrotron Radiation Lightsource. Education He received his B.S. in 1969 from the University of Virginia and his Ph.D. in 1972 from University of California at Berkeley. Research He joined Stanford's Chemistry department in 1973 and then he became a full-time chemistry professor in 1984. His principal research interests include inorganic, bioinorganic, structural and biophysical chemistry. His research group focuses on questions relating to how structure at different organizational levels relates to function. His research is done using a number of different x-ray spectroscopic and scattering techniques such as x-ray absorption spectroscopy (XAS). One of his main area of focus is the active site of the enzyme nitrogenase, which is responsible for conversion of atmospheric dinitrogen to ammonia. Using XAS studies at the S, Fe and Mo edge, his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics with the major subdisciplines of number theory, algebra, geometry, and analysis, respectively. There is no general consensus among mathematicians about a common definition for their academic discipline. Most mathematical activity involves the discovery of properties of abstract objects and the use of pure reason to prove them. These objects consist of either abstractions from nature orin modern mathematicsentities that are stipulated to have certain properties, called axioms. A ''proof'' consists of a succession of applications of deductive rules to already established results. These results include previously proved theorems, axioms, andin case of abstraction from naturesome basic properties that are considered true starting points of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
-3D-balls.png "Click for more on -> Ammonia")
