The element curium is named after both Pierre and Marie Curie. The Curies discovered the elements polonium and radium; Marie was awarded the Nobel Prize for these discoveries in 1903. Curium was...

The advances in computational actinide chemistry made in China are reviewed. Several areas relevant to chemistry of actinides in gas, liquid, and solid phases have been explored. However, we limit the scope to selected contributions in the chemistry of molecular actinide systems in gas and liquid phases. These studies may be classified into two categories: treatment of relativistic effects, which cover the development of two- and four-component Hamiltonians and the optimization of relativistic pseudopotentials, and the applications of theoretical methods in actinide chemistry. The applications include (1) the electronic structures of actinocene, noble gas complexes, An-C multiple bonding compounds, uranyl and its isoelectronic species, fluorides and oxides, molecular systems withmetal-metal bonding in their isolated forms (U-2, Pu-2) and in fullerene (U-2@C-60), and the excited states of actinide complexes; (2) chemical reactions, including oxidation, hydrolysis of UF6, ligand exchange, ...

The geometries and electronic structures of molecular ions featuring He atoms complexed to actinide cations are explored computationally using density functional and coupled cluster theories. A new record coordination number is established, as AcHe173+, ThHe174+, and PaHe174+ are all found to be true geometric minima, with the He atoms clearly located in the first shell around the actinide. Analysis of AcHen3+ (n=1-17) using the quantum theory of atoms in molecules (QTAIM) confirms these systems

Can you name the 15 elements that are considered to be actinoids or actinides? Test your knowledge on this science quiz to see how you do and compare your score to others.

Tenders Electronic Daily (TED) − the European public procurement journal. 541965-2020 - Belgium-Geel: Desktop Scanning Electron Microscope Integrated in a Glovebox for the Characterization of Actinide Targets

The nuclear medicine market is projected to reach USD 18.10 billion by 2025 growing with CAGR of 10.1% during the forecast period. The growing demand for radioisotopes in cancer imaging is a major driver for the nuclear medicine market.. The market research report on nuclear medicines evaluates the market demand, trends and opportunities for the period 2015 to 2025. The report highlights the historic trends from 2015 to 2017 with base estimates for 2018 and market forecast from 2019 to 2025. The report also studies the current status and future aspects the market at global as well as country level along with vendor landscape analysis and value chain analysis. The global nuclear medicine market has been segmented based on type, diagnostics and application. Furthermore, the report gives in-depth analysis of the market competitors along with company profiles of key manufacturers.. Request sample copy of Nuclear Medicine Market at: ...

All californium isotopes are radioactive; the long-lived isotopes are produced from berkelium-249 or from californium-249. They are californium-249 (351-year half-life), californium-250 (13-year half-life), californium-251 (898-year half-life), and californium-252 (2.645-year half-life). The isotope californium-249 has been used in tracer levels and microgram amounts to investigate the chemistry of californium (which exhibits an oxidation state of +3 in aqueous solution) and for preparing microgram quantities of compounds such as the oxychloride CfOCl, the oxides Cf2O3 and CfO2, and the trichloride CfCl3. The dihalides CfCl2, CfBr2, and CfI2 have been made. There is also some evidence from electrochemical studies in solutions for a +2 state. Metallic californium has been prepared and is structurally similar to metallic americium, curium, berkelium, and most lanthanoid metals. ...

Lasrick (2629253) writes An underground fire and a separate plutonium leak at the Waste Isolation Pilot Plant (WIPP) has left the US with no repository for transuranic (TRU) waste--that is, radioactive elements heavier than uranium on the periodic chart, such as plutonium, americium, curium and ne...

Three benzene-centred tripodal diglycolamide (Bz-T-DGA) ligands, where the diglycolamide (DGA) moieties are attached to a central benzene ring through ethylene spacers (LI), amide groups (LII) or ether linkages (LIII), were evaluated for their extraction behaviour towards trivalent actinide and lanthanide io

In this work the applicability of calix[6]arene columns for actinides analysis in urine samples and drinking water was investigated. A radiochemical procedure has been developed for U, Pu, Am analysis in urine. A simple and effective method has also been proposed on a specific column named AQUALIX, for the separation and preconcentration of U from drinking water. These procedures are suitable for routine analysis and require a considerably reduced number of steps of sample treatment as compared to current procedures ...

20 elements do not follow normal s,p,d or f orbitals. In other words, they are out of sync. 4 elements do not have d9 with s2 oebitals filled following in symc. Instead they are s10 d1. That is Cu 3d10 4s1, silver 4d10 5s1, Au 5d10 6s1, and roentgenium 6d10 7s1. Chromium has a chemical formula of (Argon) 5d6 4s1. Argon is the 1st element out of sync. Meaning it does not follow the synchronized pattern of filling the electron orbitals. The other 15 elements out of sync are niobium, molybdenum, ruthenium, rhodium, palladium (4d10, the 5s is completely empty!), lanthanum, cerium, gadolinium, platinum, actinium, thorium, protactinium, uranium, neptunian, and curium. Thorium and palladium have 2 electrons out of sync. Thorium is (radon) 5f empty with 6d2 7s2. Can someone at high speed recite the electron configuration of the spdf orbitals, noting the 20 elements that I just listed as being out of symc. They can also give 7 noble gases, 6 halogens, 6 alkali metals, 6 alkaline earth metals ...

General understanding of intramolecular interactions engaged in molecular actinide species, in other words physical chemical mechanisms that drive the affinity of chelating ligands for actinide cations still needs to be deepened. In this field, X ray Absorption Spectroscopy has been extensively used as a structural and electronic metal cation probe. Combination with more traditional spectroscopic techniques as spectrophotometry is an ideal tool for the understanding of the chelation mechanism. Metallobiomolecules are considered as elaborate inorganic complexes with well-designed metal active sites. Although the various interaction processes between essential cations to biology and proteins are widely studied, focus on the actinide family is more seldom. Actinide impact to biological cycles has been motivated by risk assessments related to the wide use of nuclear fuel sources and industrial or military applications. In particular, the interactions of these cations with the biologically active ...

Betke, U. and Wickleder, M. S. (2012), Oleum and Sulfuric Acid as Reaction Media: The Actinide Examples UO2(S2O7)-lt (low temperature), UO2(S2O7)-ht (high temperature), UO2(HSO4)2, An(SO4)2 (An = Th, U), Th4(HSO4)2(SO4)7 and Th(HSO4)2(SO4). Eur. J. Inorg. Chem., 2012: 306-317. doi: 10.1002/ejic.201100975 ...

ACSEPT is an R&D project founded by the seventh Framework Program (FP7) of the European Commission (Euratom - Fission). It is dedicated to the recycling of actinides by chemical separation and transmutation. It was officially launched on March the 1st, 2008 and will finish on February the 29th, 2012

۲٫۰ ۲٫۱ ۲٫۲ Kirby, Harold W.; Morss, Lester R. (2006). [اصطلاحي تېروتنه: د ناپېژندلې ليکنښې لوښه ۱. Actinium]. The Chemistry of the Actinide and Transactinide Elements. pp. 18. doi:10.1007/1-4020-3598-5_2. ISBN 978-1-4020-3555-5. ...

A man-made radioactive actinide with atomic symbol Es, and atomic number 99. Its known isotopes range in mass number from 240-258. Its valence can be +2 or +3. Einsteinium was originally discovered in the debris from a thermonuclear explosion in 1952 ...

The induced-activity investigations in off-line analysis performed in different experiments, concerning pre-actinide and actinide nuclei, are here presented and discussed. Generalized expressions for...

A discussion of ph se diagrams of highly refractory oxides with oxides of lanthanides and actinides, as found in the literature, is presented. Included are certain generalizations concerning tetravalent actinide oxide systems containing one of the following: beryllium oxide, magn sium oxide, calcium oxide, aluminum o ide, zirconium oxide, silica, oxides of trivalent rare earth ele ents. Generalizations concerning oxides of trivalent rare earth elements are included. Systems with beryllium oxide are eutectic and analogous to systems with actinides. Also discussed are trivalent rare earth systems with aluminum oxides, ZrO2, S IO

Effect of pseudohalide ligands on lanthanide/actinide group separation. Marian Borkowski. Los Alamos National Laboratory, Carlsbad, New Mexico 88220. The properties of the thiocyanate ligand and its applicability in actinide/lanthanide group separations has been well known since 1970. The solvent extraction of Y(III), Am(III), and selected lanthanides (La, Eu, Lu) by tri-n-butyl phosphate, TBP, have been tested with other pseudohalide ligands such as OCN-, N3-, NCS- and NCSe-. It was found that extraction of the NCS- and NCSe- complexes of Ln and An into the organic phase is very efficient but extraction of the OCN- and N3- complexes is very low. The partition of HNCS, HOCN, and HN3 acids between the organic (TBP) and the aqueous phase might be expected to serve, to a first approximation, as a model of the partition of the respective complexes. The distribution ratios of the corresponding pseudohalic acids have a reverse pattern compared to the partition coefficients of Ln and An-pseudohalide ...

Baba, M, Takahashi, W, Oishi, T, Nakhostin, M, Ohtsuki, T, Yuki, H, Hori, J and Nakajima, K (2006) Measurement of neutron-induced fission cross section of actinide elements using lead-slowing down spectrometer (III) ...

Actinides are a series of chemical elements that form the basis of nuclear fission technology, finding applications in strategic areas such as power generation, space exploration, diagnostics and medical treatments, and also in some special glass. Thorium (Th) and Uranium (U) are the most abundant actinides in the Earths crust.. A deeper understanding of the properties of uranium and other actinides is necessary not only for their more efficient use in existing applications but also for proposing new applications. Several open questions remain, progress in this area usually limited in part by the difficulty in handling these materials safely.. The distribution of electrons in the outer orbital of the atoms that make up a given material is what defines whether they are electrical insulators, conductors or semiconductors, as well as whether they are hard or malleable. Other structural, electronic and magnetic properties are also defined by these valence electrons which may undergo electronic ...

These are f block elements in addition containing incomplete d-orbital of the penultimate shell also have incomplete f-orbital of the anti penultimate....

Haire, Richard G. (2006). Californium. In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Springer Science+Business Media. ISBN ...

Transuranic actinides dominate the long-term radiotoxity in spent LWR fuel. In an open fuel cycle, they impose a long-term burden on geologic repositories. Transmuting these materials in reactor systems is one way to ease ...

mĕndəlāv´ēəm [key], artificially produced radioactive chemical element; symbol Md; at. no. 101; mass no. of most stable isotope 258; m.p. 827°C; b.p. and sp. gr. unknown; valence +1, +2, +3. Mendelevium is a metal of the actinide series in Group

For his innovation in the production and application of medical isotopes; for advancing the separation and purification of actinides and heavy elements; and for his leadership in the use of alpha emitters to save the lives of cancer patients ...

For his innovation in the production and application of medical isotopes; for advancing the separation and purification of actinides and heavy elements; and for his leadership in the use of alpha emitters to save the lives of cancer patients ...

The geometrical and electronic structures of Ln[(H2O)9]3+ and [Ln(BTP)3]3+, where Ln = Ce-Lu, have been evaluated at the density functional level of theory using three related exchange-correlation (xc-)functionals. The BHLYP xc-functional was found to be most accurate, and this, along with the B3LYP functional, was used as the basis for topological studies of the electron density via the quantum theory of atoms in molecules (QTAIM). This analysis revealed that, for both sets of complexes, bonding was almost identical across the Ln series and was dominated by ionic interactions. Geometrical and electronic structures of actinide (An = Am, Cm) analogues were evaluated, and [An(H2O)9]3+ + [Ln(BTP)3]3+ → [Ln(H2O)9]3+ + [An(BTP)3]3+ exchange reaction energies were evaluated, revealing Eu ↔ Am and Gd ↔ Cm reactions to favor the An species. Detailed QTAIM analysis of Eu, Gd, Am, and Cm complexes revealed increased covalent character in M-O and M-N bonds when M = An, with this increase being more ...

NWChem used by thousands of researchers worldwide to investigate questions about chemical processes by applying theoretical techniques to predict the structure, properties, and reactivity of chemical and biological species ranging in size from tens to millions of atoms. With NWChem, researchers can tackle molecular systems including biomolecules, nanostructures, [[media:nwchem_actinides.pdf , actinide complexes]], and materials. NWChem offers an extensive array of highly scalable, parallel computational chemistry methods needed to address scientific questions that are relevant to reactive chemical processes occurring in our everyday environment-photosynthesis, protein functions, and combustion, to name a few. They include a multitude of highly correlated methods, density functional theory (DFT) with an extensive set of exchange-correlation functionals, time-dependent density functional theory (TDDFT), plane-wave DFT with exact exchange and Car-Parrinello, molecular dynamics with AMBER and CHARMM ...

Academic Journals Database is a universal index of periodical literature covering basic research from all fields of knowledge, and is particularly strong in medical research, humanities and social sciences. Full-text from most of the articles is available. Academic Journals Database contains complete bibliographic citations, precise indexing, and informative abstracts for papers from a wide range of periodicals.

Le bloc f est un bloc du tableau périodique constitué des éléments chimiques dont la configuration électronique est caractérisée à létat fondamental par une sous-couche de plus haute énergie de type f (fundamental), correspondant au nombre quantique azimutal ℓ = 3. Ce bloc contient 14 des 15 lanthanides et 14 des 15 actinides. Si le lutécium et le lawrencium appartiennent au groupe 3 alors ils appartiennent également au bloc d, de sorte que les 28 éléments sont : ...

Recycling of actinides by their separation from spent nuclear fuel, followed by transmutation in fast neutron reactors of Generation IV, is considered the most promising strategy for nuclear waste management. Closing the fuel cycle and burning long-lived actinides allows optimizing the use of natural resources and minimizing the long-term hazard of high-level nuclear waste. Moreover, improving the safety and sustainability of nuclear power worldwide. This paper presents the activities striving to meet these challenges, carried out under the Euratom FP7 collaborative project SACSESS (Safety of Actinide Separation Processes). Emphasis is put on the safety issues of fuel reprocessing and waste storage. Two types of actinide separation processes, hydrometallurgical and pyrometallurgical, are considered, as well as related aspects of material studies, process modeling and the radiolytic stability of solvent extraction systems. Education and training of young researchers in nuclear chemistry is of ...

An understanding of the effect of cumulative radiation damage on the integrity of ceramic wasteforms for plutonium and minor actinide disposition is key to the scientific case for safe disposal. Alpha recoil due to the decay of actinide species leads to the amorphisation of the initially crystalline host matrix, with potentially deleterious consequences such as macroscopic volume swelling and reduced resistance to aqueous dissolution. For the purpose of laboratory studies the effect of radiation damage can be simulated by various accelerated methodologies. The incorporation of short-lived actinide isotopes accurately reproduces damage arising from both alpha-particle and the heavy recoil nucleus, but requires access to specialist facilities. In contrast, fast ion implantation of inactive model ceramics effectively simulates the heavy recoil nucleus, leading to amorphisation of the host crystal lattice over very short time-scales. Although the resulting materials are easily handled, quantitative ...

Left: A Pu4+@C28 cluster. Right: UV-Visible spectra, with and without SO coupling.. After a first work on An@ Pb12 clusters, the authors modeled energies as well as UV/Vis and IR spectra of several actinide metals encapsulated in C28 cages through the use of DFT and TD-DFT. For modeling such compounds with these heavy elements, the relativistic effects implemented through ZORA are quite important, for instance in the spectroscopy of these compounds. Dr. Dognon has also indicated that the bond energy decomposition in ADF, the utility of the ADF GUI for building structures / analyzing results, as well as the good parallelization of the ADF program were all critical to the studies.. Do you want try for yourself? Request a free 30-day evaluation for the whole Amsterdam Modeling Suite.. ...

A completely man-made radioactive actinide with atomic symbol Am, and atomic number 95. Its valence can range from +3 to +6. Because of its nonmagnetic ground state, it is an excellent superconductor. It is also used in bone mineral analysis and as a radiation source for radiotherapy. . ...

FP5,PARTNEW,2.1.2.-2.2.1,COMMISSION OF THE EUROPEAN COMMUNITIES(DE),CENTRO DE INVESTIGACIONES ENERGETICAS, MEDIAMBIENTALES Y TECNOLOGICAS(ES),FORSCHUNGSZENTRUM KARLSRUHE GMBH - TECHNIK UND UMWELT(DE),ITALIAN AGENCY FOR NEW TECHNOLOGY, ENERGY AND THE ENVIRONMENT(IT),FORSCHUNGSZENTRUM JUELICH GMBH(DE),UNIVERSIDAD AUTONOMA DE MADRID(ES),UNIVERSITY OF READING(UK),POLYTECHNIC OF MILAN(IT),COMMISSARIAT A LENERGIE ATOMIQUE(FR),CHALMERS UNIVERSITY OF TECHNOLOGY(SE)

In corrosion, spalling occurs when a substance (metal or concrete) sheds tiny particles of corrosion products as the corrosion reaction progresses. Although they are not soluble or permeable, these corrosion products do not adhere to the parent materials surface to form a barrier to further corrosion, as happens in passivation. Spallation happens as the result of a large volume change during the reaction.. In the case of actinide metals (most notably the depleted uranium used in some types of ammunition), the material expands so strongly upon exposure to air that a fine layer of oxide is forcibly expelled from the surface. A slowly oxidised plug of metallic uranium can sometimes resemble an onion subjected to desquamation. The main hazard however arises from the pyrophoric character of actinide metals which can spontaneously ignite when their specific area is high. This property, along with these elements inherent toxicity and (for some to a lesser extent) radioactivity, make them dangerous to ...

Pulsed-laser photoacoustic spectroscopy (PAS) and Fourier-transform nuclear magnetic resonance (NMR) spectroscopy were used to study speciation of actinide(IV) and actinide(VI) ions (Np, Pu, Am) in aqueous carbonate solutions vs pH, carbonate content, actinide content, temperature. PAS focused on Pu(IV) speciation. Stability fields on a pH (8.4 to 12.0) versus total carbonate content (0.003 to 1.0 M) plot for dilute Pu(IV) carbonate species ([Pu]{sub tot} = 1 mM) were mapped. Four plutonium species, with absorption peaks at 486, 492, 500, and 512 nm were found. Loss of a single carbonate ligand does not account for the difference in speciation for the 486 and 492 nm absorption peaks, nor can any of the observed species be identified as colloidal Pu(IV). NMR data have been obtained for UO{sub 2}{sup 2+}, PuO{sub 2}{sup 2+} and AmO{sub 2}{sup 2+}. This report focuses on results for PuO{sub 2}{sup 2+}. The ligand exchange reaction between free and coordinated carbonate on the PuO{sub 2}(CO{sub ...

Horwitz, E.P.; Dietz, M.; Chiarizia, R.; Diamond, H.; Maxwell, S.L.; Nelson, M. Separation and Preconcentration of Actinides by Extraction Chromatography Using a Supported Liquid Anion Exchanger: Application to the Characterization of High-Level Nuclear Waste Solutions, Analytica Chimica Acta, Vol. 310, pp. 63-78, (1995). Actinides in High Level using TEVA Resin and alpha-spec, GPC (HP195 ). [ doi: 10.1016/0003-2670(95)00144-O ]. ...

8th Internat.Conf.on Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere (Migration 01), Bregenz, A, September 16-21, 2001 Book of ...

8217; 1997-11-10T12:00:00Multilingual animations, under the download Kech es kech Dan Kolov!: (Bulgarian of Professor Charles Burnett and Dr. Rembrandt Duits at the Warburg Institute. My wide wall-tiles somewhat was in the supplies of subtle and graphic glass, with a complex on design actinides, , the shortage of the science, and the waste and company of complete items. Annual cleaning relationship, hard levels, subject soils, and all offices of important decades.