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Sample records for scandium complexes

  1. Stability constants of scandium complexes, 1

    International Nuclear Information System (INIS)

    Itoh, Hisako; Itoh, Naomi; Suzuki, Yasuo

    1984-01-01

    The stability constants of scandium complexes with some carboxylate ligands were determined potentiometrically at 25.0 and 40.0 0 C and at an ionic strength of 0.10 with potassium nitrate as supporting electrolyte. The constants of the scandium complexes were appreciably greater than those of the corresponding lanthanoid complexes, as expected. The changes in free energy, enthalpy, and entropy for the formation of the scandium complexes were calculated from the stability constants at two temperatures. (author)

  2. Scandium and zirconium ion complexing with salicylic acid

    International Nuclear Information System (INIS)

    Fadeeva, V.I.; Kochetkova, S.K.

    1979-01-01

    A study has been made of the extraction of complexes containing scandium and zirconium compounds and salicylic acid by using benzene, nitrobenzene, chloroform and isoamyl alcohol. It is shown that in the metal concentration range 10 -5 -10 -3 mole/l scandium forms mononuclear complexes composed of Sc(HSal) 3 (pH 2 (pH>4), zirconium - polynuclear complexes Zrsub(x)(OH)sub(y)(HSal)sub(n), where the x:n ratio varies from 0.5 to 1.5. Stability constants have been calculated for the salicylate scandium complexes in aqueous solution, equal to β 1 =(3+-1)x10 2 ; β 2 =(5.0+-0.6)x10 4 ; β 3 =(5.3+-0.3)x10 6

  3. Scandium and zirconium ion complexing with salicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Fadeeva, V I; Kochetkova, S K [Moskovskij Gosudarstvennyj Univ. (USSR)

    1979-08-01

    A study has been made of the extraction of complexes containing scandium and zirconium compounds and salicylic acid by using benzene, nitrobenzene, chloroform and isoamyl alcohol. It is shown that in the metal concentration range 10/sup -5/-10/sup -3/ mole/l scandium forms mononuclear complexes composed of Sc(HSal)/sub 3/ (pH<=4) and Sc(OH)(HSal)/sub 2/ (pH>4), zirconium - polynuclear complexes Zrsub(x)(OH)sub(y)(HSal)sub(n), where the x:n ratio varies from 0.5 to 1.5. Stability constants have been calculated for the salicylate scandium complexes in aqueous solution, equal to ..beta../sub 1/=(3+-1)x10/sup 2/; ..beta../sub 2/=(5.0+-0.6)x10/sup 4/; ..beta../sub 3/=(5.3+-0.3)x10/sup 6/.

  4. Complexing of scandium with eriochromecyanine R and cetyltrimethylammonium

    International Nuclear Information System (INIS)

    Tikhonov, V.N.; Samarkina, T.V.

    1978-01-01

    Complexing of scandium with eriochromecyanine R (ECC) in the presence of cetyltrimethylammonium (CTA) is studied. At optimum value of pH 6.2 a three-component complex of blue colour is forming with the Sc:ECC:CTA = 1:3:5 relation of compounds. Lambdasub(max) for the complex varies from 585 to 615 nm, molarabsorption coefficient is equal to (1.48+-0.02)x10 5 . A method of photometric determination of Sc with ECC and CTA is suggested. Even considerable quantities of Mg, Ca, Sr, Zn, Cd, La, Mn, Ni do not affect the Sc determination, whereas Cu, Be, Al, Ga, Fe(3) and Pd(2) affect it to a great degree even in relation of 1:1. Camouflaging substances such as fluorides, citrates, tartrates and EDTA prevent from scandium complexing, that is why they should not be used to increase the determination selectivity

  5. Study on the coextraction of scandium-yttrium-lumogallion complex

    International Nuclear Information System (INIS)

    Okada, T.; Shimoishi, Y.; Miyata, H.; Toei, K.

    1977-01-01

    The coextraction of scandium-yttrium-lumogallion [LMG;4-chloro-6-(2,4-dihydroxyphenylazo)-1-hydroxybenzene-2-sulfonic acid] into diethyl ether has been studied. The acid dissociation constants of LMG, pKsub(a2) and pKsub(a3), were estimated to be 6.24 and 8.05 respectively. The composition of the complex extracted was determined by using the radioisotopes 46 Sc and 90 Y and by spectrophotometry of LMG and the ratio of the components was Sc:Y:LMG = 1:1:3. The coextraction scheme was discussed briefly. (author)

  6. Scandium complexes with the tetraphenylethylene and anthracene dianions.

    Science.gov (United States)

    Ellis, John E; Minyaev, Mikhail E; Nifant'ev, Ilya E; Churakov, Andrei V

    2018-06-01

    The structural study of Sc complexes containing dianions of anthracene and tetraphenylethylene should shed some light on the nature of rare-earth metal-carbon bonding. The crystal structures of (18-crown-6)bis(tetrahydrofuran-κO)sodium bis(η 6 -1,1,2,2-tetraphenylethenediyl)scandium(III) tetrahydrofuran disolvate, [Na(C 4 H 8 O) 2 (C 12 H 24 O 6 )][Sc(C 26 H 20 ) 2 ]·2C 4 H 8 O or [Na(18-crown-6)(THF) 2 ][Sc(η 6 -C 2 Ph 4 ) 2 ]·2(THF), (1b), (η 5 -1,3-diphenylcyclopentadienyl)(tetrahydrofuran-κO)(η 6 -1,1,2,2-tetraphenylethenediyl)scandium(III) toluene hemisolvate, [Sc(C 17 H 13 )(C 26 H 20 )(C 4 H 8 O)]·0.5C 7 H 8 or [(η 5 -1,3-Ph 2 C 5 H 3 )Sc(η 6 -C 2 Ph 4 )(THF)]·0.5(toluene), (5b), poly[[(μ 2 -η 3 :η 3 -anthracenediyl)bis(η 6 -anthracenediyl)bis(η 5 -1,3-diphenylcyclopentadienyl)tetrakis(tetrahydrofuran)dipotassiumdiscandium(III)] tetrahydrofuran monosolvate], {[K 2 Sc 2 (C 14 H 10 ) 3 (C 17 H 13 ) 2 (C 4 H 8 O) 4 ]·C 4 H 8 O} n or [K(THF) 2 ] 2 [(1,3-Ph 2 C 5 H 3 ) 2 Sc 2 (C 14 H 10 ) 3 ]·THF, (6), and 1,4-diphenylcyclopenta-1,3-diene, C 17 H 14 , (3a), have been established. The [Sc(η 6 -C 2 Ph 4 ) 2 ] - complex anion in (1b) contains the tetraphenylethylene dianion in a symmetrical bis-η 3 -allyl coordination mode. The complex homoleptic [Sc(η 6 -C 2 Ph 4 ) 2 ] - anion retains its structure in THF solution, displaying hindered rotation of the coordinated phenyl rings. The 1D 1 H and 13 C{ 1 H}, and 2D COSY 1 H- 1 H and 13 C- 1 H NMR data are presented for M[Sc(Ph 4 C 2 ) 2 ]·xTHF [M = Na and x = 4 for (1a); M = K and x = 3.5 for (2a)] in THF-d 8 media. Complex (5b) exhibits an unsymmetrical bis-η 3 -allyl coordination mode of the dianion, but this changes to a η 4 coordination mode for (1,3-Ph 2 C 5 H 3 )Sc(Ph 4 C 2 )(THF) 2 , (5a), in THF-d 8 solution. A 45 Sc NMR study of (2a) and UV-Vis studies of (1a), (2a) and (5a) indicate a significant covalent contribution to the Sc-Ph 4 C 2 bond character. The unique Sc ate complex, (6

  7. Study of competitive complexing in scandium(3)-xylenol-orange-hydroxyethyliminodiacetic acid system

    International Nuclear Information System (INIS)

    Kornev, V.I.; Mukanov, I.P.; Artem'eva, O.A.

    1976-01-01

    The competitive complexing in the system scandium(3)-xylene orange (XO)-hydroxyethyliminodiacetic acid (H 3 L) has been studied. Ligands act as competitive particles. It has been established preliminarily that introduction of H 3 L into the solution containing a mixture of Sc and Xo changes considerably the absorption spectra of the coloured complex. Weakening of light absorption indicates that the coloured complex with XO is destructed and colourless hydroxyethyliminodiacetate of scandium is formed. The formation of scandium hydroxyethyliminoacetate has been studied spectrophotometrically by equilibrium between the complexes. The dependence of optical density on pH, when the concentrations of reagents are constant, as well as on concetration of H 3 L has been studied. The composition of the complex (1:1) formed at pH 3.2 has been established graphically and the constant of the complex ScHL + instability has been calculated (PKsub(H)=10.69+-0.45). It has been shown that H 3 L, when interacting with scandium, behaves as dibasic ligand. It is most probable that during complex formation the hydrogen ion of the hydroxygroup is not replaced, although the participation of hydroxygroup in coordination is possible due to a donor-acceptor bond

  8. Thermodynamic and kinetic study of scandium(III) complexes of DTPA and DOTA: a step toward scandium radiopharmaceuticals.

    Science.gov (United States)

    Pniok, Miroslav; Kubíček, Vojtěch; Havlíčková, Jana; Kotek, Jan; Sabatie-Gogová, Andrea; Plutnar, Jan; Huclier-Markai, Sandrine; Hermann, Petr

    2014-06-23

    Diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) scandium(III) complexes were investigated in the solution and solid state. Three (45)Sc NMR spectroscopic references suitable for aqueous solutions were suggested: 0.1 M Sc(ClO4)3 in 1 M aq. HClO4 (δSc =0.0 ppm), 0.1 M ScCl3 in 1 M aq. HCl (δSc =1.75 ppm) and 0.01 M [Sc(ox)4](5-) (ox(2-) = oxalato) in 1 M aq. K2C2O4 (δSc =8.31 ppm). In solution, [Sc(dtpa)](2-) complex (δSc = 83 ppm, Δν = 770 Hz) has a rather symmetric ligand field unlike highly unsymmetrical donor atom arrangement in [Sc(dota)](-) anion (δSc = 100 ppm, Δν = 4300 Hz). The solid-state structure of K8[Sc2(ox)7]⋅13 H2O contains two [Sc(ox)3](3-) units bridged by twice "side-on" coordinated oxalate anion with Sc(3+) ion in a dodecahedral O8 arrangement. Structures of [Sc(dtpa)](2-) and [Sc(dota)](-) in [(Hguanidine)]2[Sc(dtpa)]⋅3 H2O and K[Sc(dota)][H6 dota]Cl2⋅4 H2O, respectively, are analogous to those of trivalent lanthanide complexes with the same ligands. The [Sc(dota)](-) unit exhibits twisted square-antiprismatic arrangement without an axial ligand (TSA' isomer) and [Sc(dota)](-) and (H6 dota)(2+) units are bridged by a K(+) cation. A surprisingly high value of the last DOTA dissociation constant (pKa =12.9) was determined by potentiometry and confirmed by using NMR spectroscopy. Stability constants of scandium(III) complexes (log KScL 27.43 and 30.79 for DTPA and DOTA, respectively) were determined from potentiometric and (45)Sc NMR spectroscopic data. Both complexes are fully formed even below pH 2. Complexation of DOTA with the Sc(3+) ion is much faster than with trivalent lanthanides. Proton-assisted decomplexation of the [Sc(dota)](-) complex (τ1/2 =45 h; 1 M aq. HCl, 25 °C) is much slower than that for [Ln(dota)](-) complexes. Therefore, DOTA and its derivatives seem to be very suitable ligands for scandium

  9. Solvent extraction of tricomponent complexes of zirconium and scandium with salicylic acid and collidine

    International Nuclear Information System (INIS)

    Kochetkova, S.K.; Fadeeva, V.I.; Kalistratova, V.P.

    1976-01-01

    Extraction of tricomponent compounds of zirconium and scandium with salicylic acid (Sal) and collidine (Col) has been studied. Addition of Col widens considerably the pH range of maximum extraction of zirconium salicylate and makes it possible to extract quantitatively both zirconium and scandium in the following pH range: scandium at pH 3.8-5.2; zirconium at pH 2-4. Optimum concentrations of salicylic acid and collidine are 0.05 mol/l and 0.375 mol/l, respectively. The composition of the complexes being extracted has been studied by the shift equilibrium method. Chloroform extracts complexes having the ratio Zr:Sal:Col=1:2:1(pH=3); Sc:Sal:Col=1:3:1(pH=4), and 1:2:1(pH=5). The composition of the complexes being formed is assumed to be [Zr(OH) 3 (HSal) 2 ] - [ColH + ] (pH=3); Sc(HSal) 3 xCol (pH=4.0); Sc(OH)(HSal) 2 xCol (pH=5.0). Extraction of collidine-salicylate complexes of Hf, Th, La, and Y under the conditions of optimum extraction of zirconium and scandium has been investigated when concentration of Zr and Sc in the solution is 3.0.10μ- 5 -1.37.10 -4 mol/l, respectively. It has been shown that hafnium is extracted quantitatively (95-100%) at pH 2.3-4.6; thorium at pH 3.0-6.4; 60% of yttrium is extracted at pH 4.0-4.8; 25% of lanthanum is extracted at pH 3.3-4.9. At pH 2.0 it is possible to separate Zr from Sc,Y, and La; at pH 1.4-1.5 from small amounts of Hf and Tn. Separation of zirconium, from small amounts of hafnium, 10-fold amounts of thorium, 100-fold amounts of scandium and lanthanum is also possible

  10. Solvent extraction of tricomponent complexes of zirconium and scandium with salicylic acid and collidine

    Energy Technology Data Exchange (ETDEWEB)

    Kochetkova, S K; Fadeeva, V I; Kalistratova, V P [Moskovskij Gosudarstvennyj Univ. (USSR)

    1976-01-01

    Extraction of tricomponent compounds of zirconium and scandium with salicylic acid (Sal) and collidine (Col) has been studied. Addition of Col widens considerably the pH range of maximum extraction of zirconium salicylate and makes it possible to extract quantitatively both zirconium and scandium in the following pH range: scandium at pH 3.8-5.2; zirconium at pH 2-4. Optimum concentrations of salicylic acid and collidine are 0.05 mol/l and 0.375 mol/l, respectively. The composition of the complexes being extracted has been studied by the shift equilibrium method. Chloroform extracts complexes having the ratio Zr:Sal:Col=1:2:1(pH=3); Sc:Sal:Col=1:3:1(pH=4), and 1:2:1(pH=5). The composition of the complexes being formed is assumed to be (Zr(OH)/sub 3/(HSal)/sub 2/)/sup -/(ColH/sup +/) (pH=3); Sc(HSal)/sub 3/xCol (pH=4.0); Sc(OH)(HSal)/sub 2/xCol (pH=5.0). Extraction of collidine-salicylate complexes of Hf, Th, La, and Y under the conditions of optimum extraction of zirconium and scandium has been investigated when concentration of Zr and Sc in the solution is 3.0.10..mu..-/sup 5/-1.37.10/sup -4/ mol/l, respectively. It has been shown that hafnium is extracted quantitatively (95-100%) at pH 2.3-4.6; thorium at pH 3.0-6.4; 60% of yttrium is extracted at pH 4.0-4.8; 25% of lanthanum is extracted at pH 3.3-4.9. At pH 2.0 it is possible to separate Zr from Sc,Y, and La; at pH 1.4-1.5 from small amounts of Hf and Tn. Separation of zirconium, from small amounts of hafnium, 10-fold amounts of thorium, 100-fold amounts of scandium and lanthanum is also possible.

  11. Structural differences of half-sandwich complexes of scandium and yttrium containing bulky substituents

    Czech Academy of Sciences Publication Activity Database

    Fridrichová, Adéla; Růžička, A.; Lamač, Martin; Horáček, Michal

    2017-01-01

    Roč. 76, FEB 2017 (2017), s. 62-66 ISSN 1387-7003 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 Keywords : scandium * yttrium * half-sandwich Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.640, year: 2016

  12. Laboratory studies into the use of the scandium-46-EDTA complex as a tracer for groundwater flow

    International Nuclear Information System (INIS)

    Cheng, H.; Nixon, S.C.

    1988-01-01

    Gamma ray emitting metal radionuclides, when complexed with an appropriate complexing agent, provide a wide choice of water tracers particularly for groundwater studies where a radionuclide of appropriate half-life suited to the particular study can be selected. Scandium-46 has easily detectable gamma emission and a suitable half-life (84 days) for medium term studies. It has been widely and successfully used as a tracer in studies of sediment movement but has not yet been introduced as a groundwater tracer. In our experiments the chemical aspects of the preparation of Sc-46-EDTA were studied in some detail and its behaviour in various mineralogical environments was evaluated with reference to the standard tracer, tritiated water. The experimental results have shown that the scandium cation can be easily complexed with EDTA to form soluble SC-EDTA. The complex is very stable in a wide range of pH; the adsorptive properties of Sc-EDTA in the batch studies and the retardation and recovery in the column tests in comparison with tritiated water are quite satisfactory. In general Sc-46-EDTA is a promising tracer for groundwater studies. In the report the appropriate conditions, procedures and some rational and efficient methods for testing the purity of Sc-46-EDTA in the preparation of the tracer solution of Sc-46-EDTA are described. In addition, it has been found that the formation of the metal hydroxide colloids is the major reason for the great loss in groundwater aquifers of most trivalent metal nuclide tracers in the cationic form including scandium-46. (author). 29 refs, 11 figs, 12 tabs

  13. Scandium, yttrium and the lanthanides

    International Nuclear Information System (INIS)

    Hart, F.A.

    1987-01-01

    This chapter on the chemistry of the coordination complexes of scandium, yttrium and the lanthanides includes sections on the nitrogen and oxygen donor ligands and complex halides of scandium, and the phosphorus and sulfur donor ligands of yttrium and the lanthanides. Complexes with the macrocylic ligands and with halides are also discussed. Sections on the NMR and electronic spectra of the lanthanides are also included. (UK)

  14. Scandium fluorides

    International Nuclear Information System (INIS)

    Melnikov, P.; Nalin, M.; Messaddeq, Y.

    1997-01-01

    A new modification of scandium fluoride has been synthesised. The compound is deficient in fluorine, with the composition ScF 2.76 . It belongs to the tetragonal system, lattice parameters being a=3.792 and c=6.740 A and may be obtained at low temperatures by the decomposition of the precursor NH 4 ScF 4 . The reaction is topotactic, tetragonal parameters of the precursor are a=4.021 and c=6.744 A. Structural relationships with various fluorides and ammonium aminofluorides are discussed. This synthesis route with IR-assisted decomposition should be considered as a soft-chemistry approach. (orig.)

  15. Scandium complexes: physico-chemical study and evaluation of stability in vitro and in vivo for nuclear medicine application

    International Nuclear Information System (INIS)

    Kerdjoudj, Rabha

    2014-01-01

    Among the different isotopes of Scandium that can be used in nuclear medicine may be mentioned the 47 Sc and 44 Sc. The first decays by emitting an electron associated with a 159 keV gamma can thus be used either for radiotherapy or TEMP imaging. The 44 Sc (3.97 h) decays in 94.27% in case by emitting a positron, with a γ photon energy equal to 1.157 MeV. This isotope is then an ideal candidate for applications in PET imaging. Currently, the Cyclotron of high energy and high intensity ARRONAX produce 44 Sc and co-produces the isomeric state the 44m Sc (2.44 d). The 44m Sc has properties (E(γ) = 270 keV, 98.8%), which allows to consider its use as a potential in vivo generator. Previous work had demonstrated that the DOTA ligand is most suitable and stable for Sc. This thesis aims; make in evidence the feasibility of the in vivo 44m / 44 Sc generator. Initially a procedure was optimized and validated for the production of 44m / 44 Sc with a high specific activity and chemical purity. Radiolabeling of DOTA conjugated peptides was then developed and optimized. Theoretical and experimental studies have been performed in order to demonstrate the feasibility of 44m / 44 Sc as a potential in vivo generator. Finally, in vitro stability studies on radiolabeled 44m / 44 Sc complexes were performed, followed by biodistribution studies and PET imaging. (author)

  16. Study of iron and scandium complexing with eriochrome cyanine R and diphenylguanidine

    International Nuclear Information System (INIS)

    Chermakova, L.; Styrksh, O.R.; Yanson, Eh.Yu.; Rudzit, G.P.; Saldone, Ch.V.

    1989-01-01

    Formation conditions of the ternary mixed-ligand complexes Sc 3+ eriochromcyanine R - diphenylguanidine in the urotropin buffer solutions have been studied. The pH ranges of the maximum complexing, the optimum reagent ratios have been established. The spectrophotometric method for determination of small amounts of Sc 3+ in the form of mixed-ligand complexes has been elaborated. The Lambert's-Beer's law is valid in the concentration range 0.126-0.690 μg/ml for Sc 3+

  17. Extraction of scandium by aromatic carboxylic acids

    International Nuclear Information System (INIS)

    Kamenev, V.F.; Fadeeva, V.I.

    1977-01-01

    Extraction of complex compounds af scandium with salicylic, phenyl- and diphenylacetic acids with chloroform solutions of tetraethyldiamideheptylphosphate as a donor-active additive in relation to the pH and reagent concentration has been studied. Extraction of salicylates of some elements (Ta, Nb, Zr, Hf, Mo) by solutions of tetraethyldiamideheptylphosphate in chloroform has been investigated, and the possibility of their extraction separation from scandium is shown

  18. Extraction of scandium by aromatic carboxylic acids

    Energy Technology Data Exchange (ETDEWEB)

    Kamenev, V F; Fadeeva, V I [Moskovskij Gosudarstvennyj Univ. (USSR)

    1977-04-01

    Extraction of complex compounds af scandium with salicylic, phenyl- and diphenylacetic acids with chloroform solutions of tetraethyldiamideheptylphosphate as a donor-active additive in relation to the pH and reagent concentration has been studied. Extraction of salicylates of some elements (Ta, Nb, Zr, Hf, Mo) by solutions of tetraethyldiamideheptylphosphate in chloroform has been investigated, and the possibility of their extraction separation from scandium is shown.

  19. Ion exchange purification of scandium

    Science.gov (United States)

    Herchenroeder, Laurie A.; Burkholder, Harvey R.

    1990-10-23

    An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity.

  20. Optimizing complex scandium-3,3 benzilidene BIS [4-hydroxycoumarin] with 46Sc radiotracer

    International Nuclear Information System (INIS)

    Khanza Aktari Dewi; Muhamad Basit Febrian; Duyeh Setiawan

    2015-01-01

    Coumarin, coumarin derivatives and coumarin complex compounds known to possess biological activities such as anticancer and antiviral. The reaction between the active compound coumarin derivatives with radioisotopes Sc-46 is expected to give a complex that will be marked for further investigation of its biological activity in purpose of drug development based on coumarin. This study aims to determine the optimum conditions in the synthesis of its complex compounds as well as the physico chemical characteristics including physical properties and radiochemical purity of the complex. 3.3 benzilidene bis [4-hydroxycoumarin] ligand has successfully synthesized by reacting 4-hydroxycoumarin with benzaldehyde. Complex solids formed instantly when the solution ScCl 3 labeled by Sc-46 with a pH of 5 is reacted with a ligand solution with a pH of 11 with the optimum ratio of Sc: ligand were 1:2 with optimum labeling percentage of 99,75 ± 0,02%. FTIR analysis of complex compounds and ligands show some shift in absorption due to the formation of complex. Melting point of ligand was 234°C whilst complex compound was not yet melted in maximum range of Fischer-Jons instrument at 300°C. The complex was white reddish coloured and well soluble in DMSO. Radiochemical purity of the complex Sc-(3,3 benzilidene bis [4-hydroxycoumarin]) 2 .2H 2 O was 91.22%. Complex compound of coumarin labeled by Sc-46 has been successfully synthesized and characterized with proposed molecular formula of Sc-(3,3 benzilidene bis [4-hydroxycoumarin]) 2 .2H 2 O. (author)

  1. Mathematical modeling of complexing in the scandium-salicylic acid-isoamyl alcohol system

    International Nuclear Information System (INIS)

    Evseev, A.M.; Smirnova, N.S.; Fadeeva, V.I.; Tikhomirova, T.I.; Kir'yanov, Yu.A.

    1984-01-01

    Mathematical modeling of an equilibrium multicomponent physicochemical system for extraction of Sc salicylate complexes by isoamyl alcohol was conducted. To calculate the equilibrium concentrations of Sc complexes different with respect to the content and composition, the system of nonlinear algebraic mass balance equations was solved. Experimental data on the extraction of Sc salicylates by isoamyl alcohol versus the pH of the solution at a constant Sc concentration and different concentration of salicylate-ions were used for construction of the mathematical model. The stability constants of ScHSal 2+ , Sc(HSal) 3 , ScOH(HSal) 2 , ScoH(HSal) 2 complexes were calculated

  2. Scandium, yttrium and the lanthanide metals

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    The hydroxide and oxide phases that exist for scandium(III) include scandium hydroxide, which likely has both amorphous and crystalline forms, ScOOH(s), and scandium oxide. This chapter presents the data selected for the stability constants of the polymeric hydrolysis species of scandium at zero ionic strength. The behaviour of yttrium, and the lanthanide metals, in the environment is largely dependent on their solution equilibria. Hydrolysis and other complexation reactions of yttrium and the lanthanide metals are important in the disposal of nuclear waste. The trivalent lanthanide metals include lanthanum(III) through lutetium(III). A number of studies have reported a tetrad effect for the geochemical behaviour of the lanthanide series, including stability constants and distribution coefficients. The solubility of many of the lanthanide hydroxide phases has been studied at fixed ionic strength. In studying the hydrolysis of cerium(IV), a number of studies have utilised oxidation-reduction reactions in determining the relevant stability constants.

  3. Synthesis, structures, and electroluminescent properties of scandium N,O-chelated complexes toward near-white organic light-emitting diodes.

    Science.gov (United States)

    Katkova, Marina A; Balashova, Tatyana V; Ilichev, Vasilii A; Konev, Alexey N; Isachenkov, Nikolai A; Fukin, Georgy K; Ketkov, Sergey Yu; Bochkarev, Mikhail N

    2010-06-07

    Three members of a new class of electroluminescent, neutral, and monomeric scandium N,O-chelate complexes, namely, Sc(III)-tris-2-(2-benzoimidazol-2-yl)phenolate (1), Sc(III)-tris-2-(2-benzoxyazol-2-yl)phenolate (2), and Sc(III)-tris-2-(2-benzothiazol-2-yl)phenolate (3), have been prepared and X-ray characterized. DFT calculations have been performed. In contrast to the most frequently applied dual or multiple dopants in multilayer white OLED devices, all our simpler devices with the configuration of indium tin oxide/N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine/neat scandium complex/Yb exhibit close to near-white emission with a blue hue (CIE(x,y) = 0.2147, 0.2379) in the case of 1, a cyan hue (0.2702, 0.3524) in the case of 2, and a yellowish hue (0.3468; 0.4284) in the case of 3.

  4. Scandium Terminal Imido Chemistry.

    Science.gov (United States)

    Lu, Erli; Chu, Jiaxiang; Chen, Yaofeng

    2018-02-20

    Research into transition metal complexes bearing multiply bonded main-group ligands has developed into a thriving and fruitful field over the past half century. These complexes, featuring terminal M═E/M≡E (M = transition metal; E = main-group element) multiple bonds, exhibit unique structural properties as well as rich reactivity, which render them attractive targets for inorganic/organometallic chemists as well as indispensable tools for organic/catalytic chemists. This fact has been highlighted by their widespread applications in organic synthesis, for example, as olefin metathesis catalysts. In the ongoing renaissance of transition metal-ligand multiple-bonding chemistry, there have been reports of M═E/M≡E interactions for the majority of the metallic elements of the periodic table, even some actinide metals. In stark contrast, the largest subgroup of the periodic table, rare-earth metals (Ln = Sc, Y, and lanthanides), have been excluded from this upsurge. Indeed, the synthesis of terminal Ln═E/Ln≡E multiple-bonding species lagged behind that of the transition metal and actinide congeners for decades. Although these species had been pursued since the discovery of a rare-earth metal bridging imide in 1991, such a terminal (nonpincer/bridging hapticities) Ln═E/Ln≡E bond species was not obtained until 2010. The scarcity is mainly attributed to the energy mismatch between the frontier orbitals of the metal and the ligand atoms. This renders the putative terminal Ln═E/Ln≡E bonds extremely reactive, thus resulting in the formation of aggregates and/or reaction with the ligand/environment, quenching the multiple-bond character. In 2010, the stalemate was broken by the isolation and structural characterization of the first rare-earth metal terminal imide-a scandium terminal imide-by our group. The double-bond character of the Sc═N bond was unequivocally confirmed by single-crystal X-ray diffraction. Theoretical investigations revealed the presence

  5. Solvent extraction of anionic chelate complexes of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) with 2-thenoyltrifluoroacetone as ion-pairs with tetrabutylammonium ions

    International Nuclear Information System (INIS)

    Noro, Junji; Sekine, Tatsuya.

    1992-01-01

    The solvent extraction of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) in 0.1 mol dm -3 sodium nitrate solutions with 2-thenoyltrifluoroacetone (Htta) in the absence and presence of tetrabutylammonium ions (tba + ) into carbon tetrachloride was measured. The extraction of lanthanum(III), europium(III), and lutetium(III) was greatly enhanced by the addition of tba + ; this could be explained in terms of the extraction of a ternary complex, M(tta) 4 - tba + . However, the extractions of scandium(III) and indium(III) were nearly the same when tba + was added. The data were treated on the basis of the formation equilibrium of the ternary complex from the neutral chelate, M(tta) 3 , with the extracted ion-pairs of the reagents, tta - tba + , in the organic phase. It was concluded that the degree of association of M(tta) 3 with the ion-pair, tta - tba + , is greater in the order La(tta) 3 ≅ Eu(tta) 3 > Lu(tta) 3 , or that the stability of the ternary complex in the organic phase is higher in the order La(tta) 4 - tba + ≅ Eu(tta) 4 - tba + > Lu(tta) 4 - tba + . This is similar to those of adduct metal chelates of Htta with tributylphosphate (TBP) in synergistic extraction systems. (author)

  6. Complexation of some trivalent lanthanides, scandium(III) and thorium(IV) by benzylidenepyruvates in aqueous solution

    International Nuclear Information System (INIS)

    Marques, R.N.; Moraes, M. de; Ionashiro, M.

    1997-01-01

    The protonation constants of 4-methylbenzylidenepyruvate (4Me-BP) and 4-isopropylbenzylidenepyruvate (4IP-BP) as well as the stability constants of their binary 1:1 complexes with Cu(II), La(III), Pr(III), Sm(III), Eu(III), Yb(III), Sc(III) and Th(IV) have been determined spectrophotometrically in aqueous solution at 25 C and ionic strength 0.500 M, maintained with sodium perchlorate. For all metal ions considered, the stability changes move in the same direction as the pK a of the ligands. Linear free energy relationships, as applied to oxygen donor substances, suggest the -COCOO - moiety as the metal binding site of the ligands. The results are discussed mainly taking into account that benzylidenepyruvates, besides the α-keto canonical form, may display other forms in aqueous solution with changing pH and the possible occurrence of extra intra-ligand charge polarization, induced by metal ions. (orig.)

  7. Adsorption and desorption of hydrolyzed metal ions. 3. Scandium and chromium

    International Nuclear Information System (INIS)

    Gray, B.; Matijevic, E.; Clarkson Univ., Potsdam, NY

    1987-01-01

    Adsorption of scandium(III) and chromium(III) species on a PVC latex was measured using radioactive isotopes; the uptake increased with increasing pH. The data were interpreted by combining aspects of the models of James and Healy and also of Anderson and Bockris. The experimental and calculated results agree quite well for scandium, but not for chromium. The deviation in the latter case is believed to be due to polymerization of the hydrolyzed chromium cations and to the interaction of chromium with the anionic surface groups of the latex. Neither of these interactions occur with scandium. Hydrolyzed scandium species adsorbed on the latex were removed by acidifying the dispersion, while chromium complexes were not, substantiating the proposed difference in the chemical nature of chromium and scandium species at the solid/solution interface. 32 refs.; 8 figs.; 8 tabs

  8. Extraction of scandium salicylate by tetraethyldiamidoheptyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Kamenev, V F; Fadeeva, V I; Zyk, N V [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Analiticheskoj Khimii

    1976-11-01

    Scandium salicylate is extracted with chloroform in a narrow pH range 3-4 and at the maximum concentration of salicylic acid (H/sub 2/A) in an organic phase, the distribution coefficient reaches 0.1. In the presence of tetraethyldiamideheptylphosphate (DAHP) the zone of maximum extraction grows and the distribution coefficient increases. The ratio of the components in the complex extracted is Sc:H/sub 2/A:DAHPh=1:3:2. The extraction constant is Ksub(ex)=(2.00+-0.02).

  9. Use of scandium ionic associates with salicylic- or 2-phenylquinoline-4-carboxylic acid and rhodamine C

    Energy Technology Data Exchange (ETDEWEB)

    Kononenko, L.I.; Bel' tyukova, S V; Drobyazko, V N; Poluehktov, N S [AN Ukrainskoj SSR, Kiev. Inst. Obshchej i Neorganicheskoj Khimii; AN Ukrainskoj SSR, Odessa. Inst. Obshchej i Neorganicheskoj Khimii)

    1975-09-01

    With salicylic or 2-phenylquinoline-4-carboxylic acid and rhodamine C scandium forms ion associations whose benzene solutions are capable of luminescence. Optimum conditions for the formation of complexes and the composition of the complex with the ratio of Sc:acid:rhodamine C = 1:2:1 are established. A possibility of luminescence determination of scandium in the presence of rare earths is shown.

  10. Complexonometric photometric titration of scandium in the presence of xylenol orange

    International Nuclear Information System (INIS)

    Kornev, V.I.

    1977-01-01

    Possibility has been studied of using xylenol orange (XO) for chelatometric determination of scandium by means of various chelates with the aid of photometric techniques. It has been established that the chelates applicable for the purpose are ethylenediamineteraacetic acid (EDTA), diethylenediaminetetraacetic acid (DEDTA), diethylenetriaminepentaacetic acid (DETPA), upon introducing of which into a solution containing a complex of scandium with XO (maximum light adsorption at 550 nm) the optical density gradually diminishes. Weakening of the light absorption is, evidently, associated with the destruction of the scandium complex with XO and formation of a colourless chelate acetate with one of the chelates. Chelatometric determination of scandium, using EDTA, DEDTA and DEPTA solutions with XO should be carried out in an acidic medium at pH=2.5-3.0. In this range of pH values interferences caused by the appearance of the Sc-XO complex in the solution are insignificant

  11. Low temperature heat capacity of scandium and alloys of scandium

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, T. W.E.

    1977-12-01

    The heat capacity of three electrotransport purified scandium samples has been measured from 1 to 20/sup 0/K. The resultant electronic specific heat constant and Debye temperature are 10.337 +- 0.015 mJ/gm-atom K/sup 2/ and 346.7 +- 0.8/sup 0/K respectively, and these values are believed to be truly representative of intrinsic scandium. Alloying studies have also been carried out to investigate the band structure of scandium based on the rigid band model, with zirconium to raise the electron concentration and magnesium to lower it. The results are then compared to the theoretical band structure calculations. Low temperature heat capacity measurements have also been made on some dilute Sc-Fe alloys. An anomaly is observed in the C/T vs. T/sup 2/ plot, but the C vs. T curve shows no evidence of magnetic ordering down to 1/sup 0/K, and electrical resistance measurement from 4 to 0.3/sup 0/K also indicates that no magnetic ordering took place.

  12. Determination of scandium with salicylaldehyde and 2-aminobenzenearsonic acid

    International Nuclear Information System (INIS)

    Farias, P.A.M.; Hainberger, L.; Andrade, H.A.S.

    1984-01-01

    A new method for the spectrophotometric determination of scandium by means of a coloured complex formed with salicylaldehyde and 2-aminobenzenearsonic acid is described. Lambert-Beer's law is followed in the range of 0.2 - 2.0 μg/ml of the final solution. The maximum amounts of 39 ions that may be present without interfering in the method are listed. (Author) [pt

  13. Analogs of N-cynnamoylphenylhydroxylamine as reagents for amperometric determination of scandium

    International Nuclear Information System (INIS)

    Shvedene, N.V.; Gallaj, Z.A.; Sheina, N.M.; Zujkova, N.V.

    1978-01-01

    To decrease the detection limit of scandium and increase selectivity of amperometric determination, oxidation of 2-furylacryloyl-N-p-chlorophenylhydroxylamine (FACPhHA) and 3-styrylacryloyl-N-phenylhydroxylamine (SAPhHA) on a graphite electrode has been studied by volt-amperometry. The possibility has been established of using the oxidation current of the reagent for plotting the titration curves. The solubility of scandium complexes with FACPhHA and SAPhHA under conditions of titration against the background with pH 6.0 has been determined and equals (2.1+-0.3)x10 -6 and (5.3+-0.3)x10 -7 , respectively. The methods have been developed of amperometric determination of scandium with the use of the considered reagents against backgrounds with pH 5.5-6.5. The use of SAPhHA has decreased the limit of scandium detection down to 0.1 mgk/ml. Besides, the amperometric method makes it possible to titrate in turbid and coloured media what is an advantage of this method. The developed method is used for determination of scandium in scandium silicide

  14. Extraction of scandium by organic substance melts

    International Nuclear Information System (INIS)

    Gladyshev, V.P.; Lobanov, F.I.; Zebreva, A.I.; Andreeva, N.N.; Manuilova, O.A.; Il'yukevich, Yu.A.

    1984-01-01

    Regularities of scandium extraction by the melts of octadecanicoic acid, n-carbonic acids of C 17 -C 20 commerical fraction and mixtures of tributylphosphate (TBP) with paraffin at (70+-1) deg C have been studied. The optimum conditions for scandium extraction in the melt of organic substances are determined. A scheme of the extraction by the melts of higher carbonic acids at ninitial metal concentrations of 10 -5 to 10 -3 mol/l has been suggested. The scandium compound has been isolated in solid form, its composition having been determined. The main advantages of extraction by melts are as follows: a possibility to attain high distribution coefficients, distinct separation of phases after extraction, the absence of emulsions, elimination of employing inflammable and toxic solvents, a possibility of rapid X-ray fluorescence determinatinon of scandium directly in solid extract

  15. Effects of iron on intermetallic compound formation in scandium modified Al–Si–Mg Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Patakham, Ussadawut [National Metal and Materials Technology Center, National Science and Technology Development Agency, 114 Thailand Science Park, Klong Nueng, Klong Luang, Pathumthani 12120 (Thailand); Limmaneevichitr, Chaowalit, E-mail: chaowalit.lim@mail.kmutt.ac.th [Production Engineering Department, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Rd., Bangmod, Tungkhru, Bangkok 10140 (Thailand)

    2014-12-15

    Highlights: • Iron reduces the modification effects of scandium in Al–Si–Mg alloys. • Morphologies of Sc-rich intermetallic phases vary with Fe and Sc contents and the cooling rates. • Sc neutralizes effects of Fe by changing Fe-rich intermetallic phases from platelets to more cubic. - Abstract: In general, iron has a strong tendency to dissolve in molten aluminum. Iron has very low solid solubility in aluminum–silicon casting alloys, so it will form intermetallic compounds that cause detrimental effects on mechanical properties. In this work, the effects of iron on intermetallic compound formations in scandium modified Al–Si–Mg alloys were studied. There were two levels of iron addition (0.2 and 0.4 wt.%) and two levels of scandium addition (0.2 and 0.4 wt.%). We found that the effects of scandium modification decreased with increasing iron addition. The morphologies of the complex intermetallic compounds were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) techniques. It was found that scandium changes the morphology of Fe-rich intermetallic compounds from β-phase (plate-like) to α-phase, which reduces the harmful effects of β-phase.

  16. A basic evaluated neutronic data file for elemental scandium

    International Nuclear Information System (INIS)

    Smith, A.B.; Meadows, J.W.; Howerton, R.J.

    1992-01-01

    This report documents an evaluated neutronic data file for elemental scandium, presented in the ENDF/B-VI format. This file should provide basic nuclear data essential for neutronic calculations involving elemental scandium. No equivalent file was previously available

  17. Solution Synthesis, Structure, and CO2 Reduction Reactivity of a Scandium(II) Complex, {Sc[N(SiMe3 )2 ]3 }.

    Science.gov (United States)

    Woen, David H; Chen, Guo P; Ziller, Joseph W; Boyle, Timothy J; Furche, Filipp; Evans, William J

    2017-02-13

    The first crystallographically characterizable complex of Sc 2+ , [Sc(NR 2 ) 3 ] - (R=SiMe 3 ), has been obtained by LnA 3 /M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction of Sc(NR 2 ) 3 with K in the presence of 2.2.2-cryptand (crypt) and 18-crown-6 (18-c-6) and with Cs in the presence of crypt. Dark maroon [K(crypt)] + , [K(18-c-6)] + , and [Cs(crypt)] + salts of the [Sc(NR 2 ) 3 ] - anion are formed, respectively. The formation of this oxidation state of Sc is also indicated by the eight-line EPR spectra arising from the I=7/2 45 Sc nucleus. The Sc(NR 2 ) 3 reduction differs from Ln(NR 2 ) 3 reactions (Ln=Y and lanthanides) in that it occurs under N 2 without formation of isolable reduced dinitrogen species. [K(18-c-6)][Sc(NR 2 ) 3 ] reacts with CO 2 to produce an oxalate complex, {K 2 (18-c-6) 3 }{[(R 2 N) 3 Sc] 2 (μ-C 2 O 4 -κ 1 O:κ 1 O'')}, and a CO 2 - radical anion complex, [(R 2 N) 3 Sc(μ-OCO-κ 1 O:κ 1 O')K(18-c-6)] n . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Solution synthesis, structure, and CO{sub 2} reduction reactivity of a Scandium(II) complex, {Sc[N(SiMe_3)_2]_3}{sup -}

    Energy Technology Data Exchange (ETDEWEB)

    Woen, David H.; Chen, Guo P.; Ziller, Joseph W.; Furche, Filipp; Evans, William J. [Department of Chemistry, University of California, Irvine, CA (United States); Boyle, Timothy J. [Sandia National Laboratories, Advanced Materials Laboratory, Albuquerque, NM (United States)

    2017-02-13

    The first crystallographically characterizable complex of Sc{sup 2+}, [Sc(NR{sub 2}){sub 3}]{sup -} (R=SiMe{sub 3}), has been obtained by LnA{sub 3}/M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction of Sc(NR{sub 2}){sub 3} with K in the presence of 2.2.2-cryptand (crypt) and 18-crown-6 (18-c-6) and with Cs in the presence of crypt. Dark maroon [K(crypt)]{sup +}, [K(18-c-6)]{sup +}, and [Cs(crypt)]{sup +} salts of the [Sc(NR{sub 2}){sub 3}]{sup -} anion are formed, respectively. The formation of this oxidation state of Sc is also indicated by the eight-line EPR spectra arising from the I=7/2 {sup 45}Sc nucleus. The Sc(NR{sub 2}){sub 3} reduction differs from Ln(NR{sub 2}){sub 3} reactions (Ln=Y and lanthanides) in that it occurs under N{sub 2} without formation of isolable reduced dinitrogen species. [K(18-c-6)][Sc(NR{sub 2}){sub 3}] reacts with CO{sub 2} to produce an oxalate complex, {K_2(18-c-6)_3}{[(R_2N)_3Sc]_2(μ-C_2O_4-κ"1O:κ"1O'')}, and a CO{sub 2}{sup -} radical anion complex, [(R{sub 2}N){sub 3}Sc(μ-OCO-κ{sup 1}O:κ{sup 1}O')K(18-c-6)]{sub n}. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Method for chromatographically recovering scandium and yttrium

    International Nuclear Information System (INIS)

    Snyder, T.S.; Stoltz, R.A.

    1991-01-01

    This paper describes a method for chromatographically recovering scandium and yttrium from the residue of a sand chlorinator. It comprises: providing a residue from a sand chlorinator, the residue containing scandium, yttrium, sodium, calcium and at least one radioactive metal of the group consisting of radium, thorium and uranium; digesting the residue with an acid to produce an aqueous liquid containing scandium, yttrium, sodium, calcium and at least one radioactive metal of the group consisting of radium, thorium and uranium; feeding the metal containing liquid through a cation exchanger; eluding the cation exchanger with an acid eluant to to produce: a first eluate containing at least half of the total weight of the calcium and sodium in the feed liquid; a second eluate containing at least half of the total weight of the one or more radioactive metals in the feed liquid; a third eluate containing at least half of the yttrium in the feed liquid, and a fourth eluate containing at least half of the weight of the scandium in the feed liquid

  20. Complexometric determination of scandium and aluminium

    International Nuclear Information System (INIS)

    Tikhonov, V.N.

    1980-01-01

    Described is the complexometric determination of scandium and aluminium by the method of reverse titration of EDTA excess by indium salt solution in the presence of the xylenol orange indicator. For the method selectivity increase fluorides are used as a camouflage substance at low pH values (2.5-3.0). The excess fluoride-ions preventing titration are bound by boric acid. Y, Tb, Ti, Zr, Cu, Zn, V, Mo, Co, Cr prevent the determination of Sc and Al

  1. Ternary scandium and transition metals germanides

    International Nuclear Information System (INIS)

    Kotur, B.Ya.

    1992-01-01

    Brief review of data on phase diagram of ternary Sc-Me-Ge systems (Me-d - , f-transition element) is given. Isothermal sections at 870 and 1070 K of 17 ternary systems are plotted. Compositions and their structural characteristics are presented. Variability of crystal structure is typical for ternary scandium germanides: 70 compounds with the studied structure belong to 23 structural types. Ternary germanides isostructural to types of Sm 4 Ge 4 , ZrCrSi 2 , ZrNiAl, ScCeSi, TiNiSi U 4 Re 7 Si 6 145 compounds from 70 under investigation are mostly formed in studied systems

  2. Scandium: its occurrence, chemistry, physics, metallurgy, biology, and technology

    International Nuclear Information System (INIS)

    Horovitz, C.T.

    1975-01-01

    This book describes the following aspects of scandium: discovery and history, occurrence in nature, geochemistry and mineralogy, chemical, physical and technological properties, fabrication and metallurgy, its biological significance and toxicology, and its uses. (Extensive references for each chapter)

  3. Interaction of scandium sesquioxide with carbon

    International Nuclear Information System (INIS)

    Vodop'yanov, A.G.; Zakharov, R.G.

    1986-01-01

    In the range of 2350-2470 degrees K at a PCO = 0.0 MPa, interaction in Sc 2 O 3 with carbon mixtures initially occurs by CO chemisorption at the scandium oxide surface and disproportionation into CO 2 and C, with subsequent replacement of oxygen in the oxide anion sublattice by carbon to form ScC. The carbide melt, creating a contact between the reagents, then transforms the process to a diffusion-based one. At 1820-2220 K in vacuum, reduction of the studied mixtures occurs by dissociative vaporization of the oxide, with precipitation of ScC at the carbon surface and generation of CO. The appearance of CO in the vapors of mixture leads to formation of an oxycarbide phase and to the partial occurrence of oxide dissociation

  4. The crystal structure of scandium dyhydrate triglycolate

    International Nuclear Information System (INIS)

    Dukareva, L.M.; Antishkina, A.S.; Porai-Koshits, M.A.; Ostrikova, V.N.; Arkhangel'skij, I.V.; Amanov, A.Z.

    1978-01-01

    The structure of colorless crystals of scandium glycolate dehydrate Sc(CH 2 OHCOO) 3 x2H 2 O, synthesized at the chemical department of MSU has been investigated. Parameters of the monoclinic lattice are determined according to roentgenograms of swing and Kforograms and are specified using the DRON-1 diffractor: a=14.624-+0.005 A; b=13.052-+0.003 A; c=5.730+-0.003 A; γ=96.26 deg+-0.01 deg; rhosub(exper.)=1.09 g/cm 3 ; Z=4; Sp.=P 2/b. Experimental photographic data are obtained using the KFOR chamber. Scannings of the layer lines h anti Ko-h anti K4, containing 742 independent reflexes are taken. Deciphering of the structure is carried out by means of analysis of the Paterson functions distribution and conventional and differential electron densities. Description of the system is presented

  5. Scandium interaction with diantipyrylmethane homologues and 2-(n-sulphophenylazo)-1,8-dihydroxynaphthalene-3,6 sodium disulphonate

    Energy Technology Data Exchange (ETDEWEB)

    Ganago, L I; Alinovskaya, L A [AN Belorusskoj SSR, Minsk. Inst. Fiziki Tverdogo Tela i Poluprovodnikov

    1979-01-01

    The reactions of scandium with homologs of diantipyrilmethane (DAM)-propyldiantipyrilmethane (PDAM) and phenyldiantipyrilmethane (PhDAM) - are studied. The relationship of components in the complexes formed is found, and chemism of their formation is established. The complexes Sc-SPADNE (sodium salt 2-(n-sulphophenylazo)-1,8-dioxynaphthalene-3,6-disulphonic acid) are shown to form within a wide pH range. The maximum yield of complexes is observed at 6.0-7.5 pH. By the ion-exchange method the anion character of heteroligand scandium complexes is established. The complex Sc-SPADNE-PDAM is faster as compared with the complexes Sc-SPADNE-DAM and Sc-SPADNE-PhDAM. The decrease in amine excess and increase in the sensitivity of heteroligand formation of the complexes of scandium with SPADNE and PDAM make them better suited for analysis. The technique is developed for the determination of Sc/sub 2/O/sub 3/ in perovskites using the complete differential spectrophotometry method.

  6. Lifetime measurements and oscillator strengths in singly ionized scandium and the solar abundance of scandium

    Science.gov (United States)

    Pehlivan Rhodin, A.; Belmonte, M. T.; Engström, L.; Lundberg, H.; Nilsson, H.; Hartman, H.; Pickering, J. C.; Clear, C.; Quinet, P.; Fivet, V.; Palmeri, P.

    2017-12-01

    The lifetimes of 17 even-parity levels (3d5s, 3d4d, 3d6s and 4p2) in the region 57 743-77 837 cm-1 of singly ionized scandium (Sc II) were measured by two-step time-resolved laser induced fluorescence spectroscopy. Oscillator strengths of 57 lines from these highly excited upper levels were derived using a hollow cathode discharge lamp and a Fourier transform spectrometer. In addition, Hartree-Fock calculations where both the main relativistic and core-polarization effects were taken into account were carried out for both low- and high-excitation levels. There is a good agreement for most of the lines between our calculated branching fractions and the measurements of Lawler & Dakin in the region 9000-45 000 cm-1 for low excitation levels and with our measurements for high excitation levels in the region 23 500-63 100 cm-1. This, in turn, allowed us to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical oscillator strengths for a set of 380 E1 transitions in Sc II. These oscillator strengths include the weak lines that were used previously to derive the solar abundance of scandium. The solar abundance of scandium is now estimated to logε⊙ = 3.04 ± 0.13 using these semi-empirical oscillator strengths to shift the values determined by Scott et al. The new estimated abundance value is in agreement with the meteoritic value (logεmet = 3.05 ± 0.02) of Lodders, Palme & Gail.

  7. Highly sensitive luminescence method of scandium determination in the products of metallurgical reprocessing

    International Nuclear Information System (INIS)

    Matveets, M.A.; Akhmetova, S.D.

    1988-01-01

    Highly sensitive reaction of scandium with 1,10-phenanthroline and eosin is used for the development of luminescence method of its determination in metallurgical products. The effect of interfering elements is eliminated by scandium extraction with monocarboxylic acids. The method permits to determine scandium content from 5 x 10 -5 % (Sr 0.15 - 0.25)

  8. Size Effects on Deformation and Fracture of Scandium Deuteride Films.

    Energy Technology Data Exchange (ETDEWEB)

    Teresi, C. S. [Univ. of Minnesota, Minneapolis, MN (United States); Hintsala, E. [Univ. of Minnesota, Minneapolis, MN (United States); Hysitron, Inc., Eden Prairie, MN (United States); Adams, David P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yang, Nancy Y. C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kammler, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moody, N. R. [Univ. of Minnesota, Minneapolis, MN (United States); Gerberich, W. W. [Univ. of Minnesota, Minneapolis, MN (United States)

    2017-07-01

    Metal hydride films have been observed to crack during production and use, prompting mechanical property studies of scandium deuteride films. The following focuses on elastic modulus, fracture, and size effects observed in the system for future film mechanical behavior modeling efforts. Scandium deuteride films were produced through the deuterium charging of electron beam evaporated scandium films using X-ray diffraction, scanning Auger microscopy, and electron backscatter diffraction to monitor changes in the films before and after charging. Scanning electron microscopy, nanoindentation, and focused ion beam machined micropillar compression tests were used for mechanical characterization of the scandium deuteride films. The micropillars showed a size effect for flow stress, indicating that film thickness is a relevant tuning parameter for film performance, and that fracture was controlled by the presence of grain boundaries. Elastic modulus was determined by both micropillar compression and nanoindentation to be approximately 150 GPa, Fracture studies of bulk film channel cracking as well as compression induced cracks in some of the pillars yielded a fracture toughness around 1.0 MPa-m1/2. Preliminary Weibull distributions of fracture in the micropillars are provided. Despite this relatively low value of fracture toughness, scandium deuteride micropillars can undergo a large degree of plasticity in small volumes and can harden to some degree, demonstrating the ductile and brittle nature of this material

  9. Formation of scandium carbides and scandium oxycarbide from the elements at high-(P, T) conditions

    International Nuclear Information System (INIS)

    Juarez-Arellano, Erick A.; Winkler, Bjoern; Bayarjargal, Lkhamsuren; Friedrich, Alexandra; Milman, Victor; Kammler, Daniel R.; Clark, Simon M.; Yan Jinyuan; Koch-Mueller, Monika; Schroeder, Florian; Avalos-Borja, Miguel

    2010-01-01

    Synchrotron diffraction experiments with in situ laser heated diamond anvil cells and multi-anvil press synthesis experiments have been performed in order to investigate the reaction of scandium and carbon from the elements at high-(P,T) conditions. It is shown that the reaction is very sensitive to the presence of oxygen. In an oxygen-rich environment the most stable phase is ScO x C y , where for these experiments x=0.39 and y=0.50-0.56. If only a small oxygen contamination is present, we have observed the formation of Sc 3 C 4 , Sc 4 C 3 and a new orthorhombic ScC x phase. All the phases formed at high pressures and temperatures are quenchable. Experimentally determined elastic properties of the scandium carbides are compared to values obtained by density functional theory based calculations. - Graphical Abstract Legend (TOC Figure): Table of Contents Figure Selected images recorded with a MAR345 image plate detector show the reaction of α-Sc and graphite at high-(P,T) conditions. Left: mixture of α-Sc and graphite. Right: recovered sample after laser heated the diamond anvil cell.

  10. Smelting of Scandium by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Satoshi Fujii

    2017-09-01

    Full Text Available Scandium is being explored as an alloying element for aluminum alloys, which are gaining importance as high-performance lightweight structural alloys in the transportation industry. A few years ago, Sc was also found to be suitable for use in electrical devices. High-Sc-content ScAlN thin films have attracted significant attention because of their strong piezoelectricity. The piezoelectric response of ScAlN suggests that ScAlN thin films formed on a hard substrate would be suitable surface acoustic wave wideband filters for next-generation wireless communication systems. However, it is often difficult to use ScAlN thin films in MEMS devices—including acoustic ones—because of the extremely high price of metallic Sc, given the difficulty associated with smelting it. Here, we propose a novel process for smelting Sc metal by microwave irradiation. Sc metal was able to be obtained successfully from ScF3 through a microwave-irradiation-based carbon reduction reaction. The reaction temperature for this reduction process was approximately 880°C, which is half of that for the conventional smelting process involving reduction with Ca. Thus, the proposed microwave irradiation process has significant potential for use in the smelting of Sc metal.

  11. Scandium/carbon filters for soft x rays

    NARCIS (Netherlands)

    Artioukov, IA; Kasyanov, YS; Kopylets, IA; Pershin, YP; Romanova, SA

    2003-01-01

    This Note deals with thin-film soft x-ray filters for operation at the wavelengths near carbon K edge (similar to4.5 nm). The filters were fabricated by magnetron sputtering deposition of thin layers of scandium (total thickness 0.1-0.2 mum) onto films of polypropylene (thickness 1.5 mum) and

  12. Heat capacity and solid solubility of iron in scandium

    International Nuclear Information System (INIS)

    Tsang, T.-W.E.

    1981-01-01

    The maximum solid solubility of iron in scandium was determined to be between 50 and 85 at.ppm in the as-cast condition. As the concentration of iron increases, it segregates along the grain boundary, as is evident from optical metallography and electron microprobe examinations. Annealing also causes the iron dissolved in scandium to separate out and cluster along the grain boundary. Heat capacity measurements show an anomaly in the C/T versus T 2 plots for iron concentrations of 19 at.ppm or greater. For iron dissolved in solid scandium the excess entropy due to the iron impurity is in agreement with the theoretical prediction of ck ln(2S + 1) for an impurity-conduction electron (Kondo) interaction, but is 4 - 8 times larger than the theoretical prediction when iron segregates along the grain boundary. Furthermore, our results suggest that most of the previously reported low temperature physical properties of scandium are probably in error because of either iron impurity-conduction electron interactions or Fe-Fe interactions in the precipitated second-phase Sc-Fe compound. (Auth.)

  13. Thermoelectric material comprising scandium doped zinc cadmium oxide

    DEFF Research Database (Denmark)

    2016-01-01

    There is presented a composition of scandium doped Zinc Cadmium Oxide with the general formula ZnzCdxScyO which the inventors have prepared, and for which material the inventors have made the insight that it is particularly advantageous as an n-type oxide material, such as particularly advantageous...

  14. Synthesis and properties of scandium ortho-phosphate

    International Nuclear Information System (INIS)

    Eshchenko, L.S.; Pechkovskij, V.V.; Dvoskina, R.N.

    1979-01-01

    With the aim to elucidate the influence of synthesis conditions on the chemical composition and properties of orthophosphates of scandium, the interaction of orthophosphoric acid and scandium-containing component (oxide or salt) was studied under various conditions. In the interaction of scandium salt, phosphoric acid and ammonia at room temperature and pH 3.0; 5.0; 7.0 and 9.0 amorphous scandium phosphates have been obtained with the composition of x Sc 2 O 3 xY P 2 O 5 xz NH 3 xn H 2 O. After prolonged staying in mother liquor, roentgenoamorphous precipitates of phosphates transform into the crystalline state. The dependences are studied of the specific surface of amorphous phosphates on pH of precipitation and temperature of the heat treatment (200-800 deg C). Precipitates obtained in a neutral medium at 400 deg C temperature of thermal treatment, show a maximum specific surface. At a temperature of 820-840 deg C the crystallization of amorphous phase occurs followed by the recrystallization and formation of anhydrous SePO 4 of zircon type

  15. Characterization and excitation behaviour studies of radionuclide (scandium) in glass matrix

    International Nuclear Information System (INIS)

    Rehana, Ishrat; Shahid, K.A.; Husain, S.; Muhammad, Din

    1999-01-01

    Directional movements of bed load in marine sediments are studied using a radioactive tracer, scandium, similar to the natural sediment in the area. Scandium glass prepared for this purpose was analyzed by atomic emission spectrography for quality assurance purposes. A buffer composed of graphite with 5% germanium oxide was used for accurate and reproducible analyses. The role of this buffer in the excitation behavior of scandium and variations in spectral line intensity with respect to various influencing parameters are reported. Volatilization of scandium was observed using the moving plate technique, with a dc-arc as the excitation source

  16. Complexometric determination of aluminium and scandium using fluorides as masking agent at low pH value

    International Nuclear Information System (INIS)

    Tikhonov, V.N.

    1978-01-01

    A complexometric method is suggested to determine Al and Sc by back titration of Bi(NO 3 ) 3 solution with xylenol orange indicator at low pH values. To increase selectivity fluoride additions were used which were masked by boron acid at the end titration point. EDTA was used as a complexing agent. Metals which create at low pH values stable complexes with EDTA undestroyed by fluoride, do not interfere with Al and Sc determination. Scandium is shown to be determined more selectively than aluminium

  17. Scandium - problem of ultra-trace-element essentiality

    International Nuclear Information System (INIS)

    Kist, A.A.; Zkuk, L.I.; Danilova, E.A.; Makhmudov, E.A.

    2006-01-01

    Full text: Role of constitutional and essential elements in Life is known quite well. It is also well known that all chemical elements present in the living matter. Nevertheless essentiality of at least 55 chemical elements (more than a half of number of natural elements) is still not accepted. In many cases these elements presumably play important role in the Life. On the other hand their essentiality is still under doubt. One of the 'strange' elements in this connection is scandium. Scandium is an element which is very 'simple' for instrumental neutron activation analysis (INAA). For many years in our laboratory were carried out studies on animals and human tissues and fluids elemental composition using INAA in which data for scandium were obtained as 'redundant' information. Essentiality of scandium was newer proven using accepted criteria of elements. Nevertheless in our studies were found various regularities, statistically significant inter-elemental correlations and correlations between elements in tissues and fluids versus clinic and biochemical data. There are some examples. There were found correlations of scandium hair concentration and blood glucose (r=0.68±0.13), body mass index (r=0.86±0.07), leukocyte with phagocytic activity migration inhibition test (r=0.68±0.18), size of cavity of the left heart auricle (r=-0.65±0.16), final systolic bulk (r=0.80±0.12), stroke output of heart (r=-0.79±0.12), final diastolic bulk (0.88±0.0080) etc. In addition using gel filtration in rat liver cytosol was found peak of scandium in elution curve. Examples and correlations given in the paper say in favor that scandium may play quite important role in biological processes and that the biological role of scandium should be studied more intensive. The most important criterion is an appearance of the organism dysfunction in case of removal of the studied elements from the diet (intake) which in all other sides remains completely valuable and disappearance of all

  18. Incommensurate composite crystal structure of scandium-II

    International Nuclear Information System (INIS)

    Fujihisa, Hiroshi; Gotoh, Yoshito; Yamawaki, Hiroshi; Sakashita, Mami; Takeya, Satoshi; Honda, Kazumasa; Akahama, Yuichi; Kawamura, Haruki

    2005-01-01

    The long-unknown crystal structure of the high pressure phase scandium-II was solved by powder x-ray diffraction and was found to have tetragonal host channels along the c axis and guest chains that are incommensurate with the host, as well as the high pressure phases of Ba, Sr, Bi, and Sb. The pressure dependences of the lattice constants, the incommensurability, the atomic distances, and the atomic volume were investigated

  19. Tetragonal ternary borides: superconductivity, ferromagnetism and the role of scandium

    International Nuclear Information System (INIS)

    Matthias, B.T.; Patel, C.K.N.; Barz, H.; Corenzwit, E.; Vandenberg, J.M.

    1978-01-01

    The authors report and discuss two discoveries made while studying the condensation phenomena of ternary rhodium borides, MRh 4 B 4 . M is generally a trivalent transition metal, usually a rare earth element RE. An exception is scandium which by itself does not form an isomorphous boride, but in combination with many other elements will do just that. A suprising correlation between ferromagnetic and superconducting transition temperatures has been found. (Auth.)

  20. The characteristics of aluminum-scandium alloys processed by ECAP

    International Nuclear Information System (INIS)

    Venkateswarlu, K.; Rajinikanth, V.; Ray, Ajoy Kumar; Xu Cheng; Langdon, Terence G.

    2010-01-01

    Aluminum-scandium alloys were prepared having different scandium additions of 0.2, 1.0 and 2.0 wt.% and these alloys were processed by equal-channel angular pressing (ECAP) at 473 K. The results show the grain refinement of the aluminum matrix and the morphology of the Al 3 Sc precipitates depends strongly on the scandium concentration. The tensile properties were evaluated after ECAP by pulling to failure at initial strain rates from 1.0 x 10 -3 to 1.0 x 10 -1 s -1 . The Al-1% Sc alloy exhibited the highest tensile strength of ∼250 MPa at a strain rate of 1.0 x 10 -1 s -1 . This alloy also exhibited a superior grain refinement of ∼0.4 μm after ECAP where this is attributed to a smaller initial grain size and an optimum volume fraction of dispersed Al 3 Sc precipitates having both micrometer and nanometer sizes.

  1. A new model for prediction of dispersoid precipitation in aluminium alloys containing zirconium and scandium

    International Nuclear Information System (INIS)

    Robson, J.D.

    2004-01-01

    A model has been developed to predict precipitation of ternary Al 3 (Sc, Zr) dispersoids in aluminium alloys containing zirconium and scandium. The model is based on the classical numerical method of Kampmann and Wagner, extended to predict precipitation of a ternary phase. The model has been applied to the precipitation of dispersoids in scandium containing AA7050. The dispersoid precipitation kinetics and number density are predicted to be sensitive to the scandium concentration, whilst the dispersoid radius is not. The dispersoids are predicted to enrich in zirconium during precipitation. Coarsening has been investigated in detail and it has been predicted that a steady-state size distribution is only reached once coarsening is well advanced. The addition of scandium is predicted to eliminate the dispersoid free zones observed in scandium free 7050, greatly increasing recrystallization resistance

  2. Kinetics and mechanism of hydrolysis of scandium sulfate

    International Nuclear Information System (INIS)

    Koshchej, E.V.; Stryapkov, A.V.; Podosenov, D.E.; Makarov, G.V.; Razdobreev, D.A.

    1998-01-01

    The Sc 2 (SO 4 ) 3 -H 2 SO 4 -H 2 O system is studied through the methods of pH-potentiometry, conductometry and turbidimetry at 298 and 318 K and ion force 0.01, 0.1 and 1.0. The hydrolysis mechanism including the processes in the system homogenous and heterogeneous constituents. The hydrolysis rates of scandium salts and their dependences on OH-ions concentration, solution ions force and temperature are found; the constants of the processes rate with participation of OH - and SO 4 2- ions and constants of the solid phase formation rate are calculated [ru

  3. Vibrational spectra of double oxides of calcium and scandium

    International Nuclear Information System (INIS)

    Porotnikov, N.V.; Kondratov, O.I.; Petrov, K.I.; Olikov, I.I.

    1981-01-01

    The vibrational spectra of calcium and scandium double oxides 40 CaSc 2 O 4 and 44 CaSc 2 O 4 in the range of 30-1000 cm -1 are studied. In the approximation of the polymer chains of the method of valent-force field the calculation of the theoretical vibrational spectrum of isotope-substituted compounds is made, the attribution of the experimental spectra is suggested, the frequency branches of the vibrations of periodic chains are built, the force field of crystals is evaluated [ru

  4. Scandium effect on mechanical properties of Al-6.5 % Mg alloy

    International Nuclear Information System (INIS)

    Drits, M.E.; Toropova, L.S.; Bykov, Yu.G.

    1982-01-01

    Quantitative evaluation of influence of small scandium additions (up to 0.5 wt%) on properties of Al-6.5% Mg binary alloy are carried out depending on test temperature in the range of -196 to 310 deg C. Alloys were tested on ''Instron'' machine at 1.3x10 - 3 s - 1 strain rate. Scandium additions are shown to increase plasticity at -196 deg C. Yield strength also increases with introduction of 0.2% Sc if deformation temperature does not exceed 250 deg C. The growth of ultimate strength is less significant. Elevated strength properties of alloys with scandium additions can be explained by a fine-grained structure

  5. Effect of scandium additions on microstructure and mechanical properties of Al-Zn-Mg alloy welds

    International Nuclear Information System (INIS)

    Dev, Selvi; Stuart, A. Archibald; Kumaar, R.C. Ravi Dev; Murty, B.S.; Rao, K. Prasad

    2007-01-01

    The microstructure and mechanical properties of fusion zones of medium strength Al-Zn-Mg alloy (RDE-40) welds obtained by using different fillers containing various amount of scandium was investigated. It was observed that addition of scandium led to very significant grain refinement in the fusion zone especially for scandium levels greater than the eutectic composition (0.55 wt%). The grain refinement led to the reduction in solidification cracking and improved the tensile properties of fusion zone compared to the ones obtained by the commercial AA5556 filler

  6. Knight shift in scandium and its alloys with hafnium and titanium

    International Nuclear Information System (INIS)

    Chachkhiani, Z.B.; Chechernikov, V.I.; Martynova, L.F.; Nidel'ko, V.I.; Chachkhiani, L.G.; Georgadze, G.S.

    1981-01-01

    Results of the investigation of NMR on 45 Sc nuclei and magnetic susceptibility of scandium and its solid solutions with titanium and hafnium are presented. It is shown that the existing hybridization of S and d zones in pure scandium and its alloys with titanium and hafnium affects the Knight shift reducing the value of the contact contribution. The temperature behaviour of the Knight shift from the temperature dependence and spin susceptibility of collectivized d electrons [ru

  7. Effect of composition on the superplasticity of aluminium scandium alloys

    International Nuclear Information System (INIS)

    Bradley, E.L. III; Morris, J.W. Jr.

    1992-01-01

    Several aluminum alloys have been shown to exhibit superplasticty in the as-rolled condition. Previous work has shown that aluminum-scandium alloys also exhibit this behavior, but only with the addition of ternary alloying elements such as lithium and magnesium. These additions raised the strain-rate sensitivity of these alloys to 0.4-0.5 for selected strain rates at temperatures above 400 degrees C. A systematic study was undertaken of five Al-Sc alloys with varying lithium and magnesium concentrations in order to fully characterize the high temperature deformation mechanism. Specimens were deformed at a constant strain rate to predetermined true strains for textural and microstructural characterization. In this paper work is presented that will elucidate the effect of these different ternary additives on the superplastic deformation mechanism in these alloys

  8. Application of scandium oxide in an electron emission material

    International Nuclear Information System (INIS)

    Suqiu, Y.; Zhizheng, Z.; Yongde, W.

    1985-01-01

    Modern microwave devices impose a number of harsh requirements on the cathodes. For instance, they require cathodes having low working temperature, high emissive current density, slow evaporation rate of the emissive-active material, long lifetime, quick heating and so on. The commercial B-cathode is no longer able to meet these requirements completely. A scandate cathode may be a promising one for use in these devices. Adding rare-earth elements in the electron emission material has been reported in many papers. Based on a B-cathode we add a little amount of scandium oxide (about 3%) into emission material to manufacture a scandate cathode. The emission property of such a cathode has been improved greatly. If the composition is controlled correctly, the emission level of such a cathode may be five times more as high as the B-cathode

  9. Order-disorder phenomenon in lead scandium tantalate

    International Nuclear Information System (INIS)

    Wang, H.C.; Schulze, W.A.

    1990-01-01

    Lead scandium tatalate (PST) is a ferroelectric relaxor with the perovskite structure of A(B'B double-prime)O 3 . By suitable heat treatment, the B-site cations can be brought from a structurally disordered state into various degree of ordering. The degree of ordering is strongly affected by the amount of vacancies present in the materials. To suppress PbO loss during the sintering or annealing process, a PbO-rich atmosphere is supplied by materials having high PbO vapor pressure, such as PbZrO 3 . For PST ceramics with nearly zero weight loss, very long annealing times and higher annealing temperatures are required for ordering. The higher PbO-loss materials are found to be easily ordered. The introduction of a reducing atmosphere during annealing enhances the ordering process. The ordering process is characterized quantitatively by X-ray diffraction and qualitatively by Raman spectroscopy

  10. Concentration and Separation of Scandium from Ni Laterite Ore Processing Streams

    Directory of Open Access Journals (Sweden)

    Şerif Kaya

    2017-12-01

    Full Text Available The presence of a considerable amount of scandium in lateritic nickel-cobalt ores necessitates the investigation of possible processing alternatives to recover scandium as a byproduct during nickel and cobalt production. Therefore, in this study, rather than interfering with the main nickel-cobalt production circuit, the precipitation-separation behavior of scandium during a pH-controlled precipitation process from a synthetically prepared solution was investigated to adopt the Sc recovery circuit into an already existing hydrometallurgical nickel-cobalt hydroxide processing plant. The composition of the synthetic solution was determined according to the hydrometallurgical nickel laterite ore processing streams obtained from a HPAL (high-pressure sulphuric acid leaching process. In order to selectively precipitate and concentrate scandium with minimum nickel and cobalt co-precipitation, the pH of the solution was adjusted by CaCO3, MgO, Na2CO3, and NaOH. It was found that precipitation with MgO or Na2CO3 is more advantageous to obtain a precipitate containing higher amounts of scandium with minimum mass when compared to the CaCO3 route, which makes further processing more viable. As a result of this study, it is proposed that by a simple pH-controlled precipitation process, scandium can be separated from the nickel and cobalt containing process solutions as a byproduct without affecting the conventional nickel-cobalt hydroxide production. By further processing this scandium-enriched residue by means of leaching, SX (solvent extraction, and precipitation, an intermediate (NH42NaScF6 product can be obtained.

  11. Analysis of separation quality of scandium-46 and titanium using silica gel column

    International Nuclear Information System (INIS)

    Muhamad Basit Febrian; Yanuar Setiadi; Duyeh Setiawan; Titin Sri Mulyati; Nana Suherman

    2015-01-01

    In this study, quality test of scandium and titanium mixture separation system using a silica gel column has been conducted. This system will be used in the separation of medical radioisotopes of 47 Sc from TiO 2 enriched targets. 20 mg of TiO 2 and 5 mg of Sc 2 O 3 dissolved using 0.5 mL of 50% HF solvent with gentle heating at 60°C - 80°C for 1 hour then 4.5 mL H 2 O was added. Sc and Ti mixture is separated by passing it through a column of silica gel. In the determination of scandium released from silica gel, Sc-46 radiotracer was used. Only 51.60 ± 4.5% of 5 mg of scandium could be retained in the silica gel column. From 51.60% of absorbed scandium in the column, 98.29 ± 3.4% were eluted with 5 mL of H 2 O eluent. During elution of scandium from silica gel column, 2.81 grams of 20 mg of titanium came apart as breakthrough. In determination of recovery of titanium from silica gel, 51.76 ± 5.5% of the 20 mg Ti can be recovered from silica gel column using 5M HCl eluent, whereas remaining Ti were eluted using 40 ml of HCl 5M. Based on those result, it can be concluded that there are still titanium portion in scandium after the separation using a silica gel column. Further purification step using fresh silica gel column, can separate escaped titanium from scandium. (author)

  12. Partitioning of Iron and Scandium in Soils Having Water Drainage Limitations

    International Nuclear Information System (INIS)

    Aide, M.; Braden, I.; Mueller, W.

    2010-01-01

    Soil chemistry of Fe includes weathering reactions, adsorption, hydrolysis, complexation, and oxidation-reduction reactions. Soil chemistry for scandium (Sc) is similar, but Sc does not include oxidation-reduction reactions. To determine if geochemical analysis may be used to identify Sc partitioning with respect to Fe among the particle size fractions, two Alfisol and two Ultisol soils were assessed using an aqua-regia digestion to estimate Sc and Fe concentrations for whole soil and particle size separates. Aqua-regia digestion data showed Sc depletion relative to Fe in sand separate. Sand separate is largely composed on quartz sand and Fe-Mn-bearing nodules, which are redoximorphic features produced by alternating oxic and suboxic/anoxic conditions associated with seasonally fluctuating water tables. Relative partitioning of Fe and Sc in these soils warrants further study to assess if selective extractions could quantify the extent of modern or ancestral oxidation-reduction processes responsible in some soil features involved in soil genesis.

  13. Effect of Aqueous Media on the Recovery of Scandium by Selective Precipitation

    Directory of Open Access Journals (Sweden)

    Bengi Yagmurlu

    2018-05-01

    Full Text Available This research presents a novel precipitation method for scandium (Sc concentrate refining from bauxite residue leachates and the effect of aqueous media on this triple-stage successive precipitation process. The precipitation pattern and the precipitation behavior of the constituent elements was investigated using different precipitation agents in three major mineral acid media, namely, H2SO4, HNO3, and HCl in a comparative manner. Experimental investigations showed behavioral similarities between HNO3 and HCl media, while H2SO4 media was different from them because of the nature of the formed complexes. NH4OH was found to be the best precipitation agent in every leaching media to remove Fe(III with low Sc co-precipitation. To limit Sc loss from the system, Fe(III removal was divided into two steps, leading to more than 90% of Fe(III removal at the end of the process. Phosphate concentrates were produced in the final step of the precipitation process with dibasic phosphates which have a strong affinity towards Sc. Concentrates containing more than 50% of ScPO4 were produced in each case from the solutions after Fe(III removal, as described. A flow diagram of the selective precipitation process is proposed for these three mineral acid media with their characteristic parameters.

  14. On interaction of zirconium isopropylate with scandium and lanthanum isopropylates. Alkoxozirconates of the scandium subgroup

    International Nuclear Information System (INIS)

    Turova, N.Ya.; Kozlova, N.I.

    1982-01-01

    The solubility in the Zr(OR) 4 -Sc(OR) 3 -THF and Zr(OR) 4 -La(OR) 3 -ROH (R=iso-Pr) at 20 deg was studied. It was ascertained that complex formation did not occur in the first system and LaZr 3 (OR) 15 x3ROH were present in the second one. Complex properties were studied by the methods of IR, PMR spectroscopy, mass-spectrometric and preparative methods. A structure with octahedric coordination of M 3 and Zr atoms was supposed for M 3 Zr 3 (OR) 15 x3L (M=Y, La). Regularities in the change of Sc, Y, La alkoxozirconates were established

  15. Double tungstates of metals of scandium and ammonium subgroups

    Energy Technology Data Exchange (ETDEWEB)

    Maksin, V I [AN Ukrainskoj SSR, Kiev. Inst. Kolloidnoj Khimii i Khimii Vody

    1980-06-01

    The methods of pH-potentiometry, conductometry, determination of residual concentrations of liquid phases and precipitations, selected by chemical analysis have been used for investigation R(NO/sub 3/)/sub 3/-(NH/sub 4/)/sub 2/WO/sub 2/-H/sub 2/O systems, (where R=Sc, Y, La). The formation of double tungstates NH/sub 4/R(WO/sub 4/)/sub 2/xnH/sub 2/O is established. The NH/sub 4/Sc(WO/sub 4/)/sub 2/x4.5H/sub 2/O, NH/sub 4/Yx(WO/sub 4/)/sub 2/x3H/sub 2/O, NH/sub 4/La(WO/sub 4/)/sub 2/x1.5H/sub 2/O compounds are synthesized in individual form. Precipitation conditions (pH, concentration ratio) and composition of the solid phase are determined. The behaviour of synthesized slats at thermolysis up to 880 deg C is studied. Physicochemical properties (color, solubility of the simple and double tungstates of scandium, yttrium and lanthanum with ammonium) is studied. IR spectra and X-ray diffraction analysis give idea about double salts structural transformations.

  16. Hydrogen storage in thin film magnesium-scandium alloys

    International Nuclear Information System (INIS)

    Niessen, R.A. H.; Notten, P.H. L.

    2005-01-01

    Thorough electrochemical materials research has been performed on thin films of novel magnesium-scandium hydrogen storage alloys. It was found that palladium-capped thin films of Mg x Sc (1-x) with different compositions (ranging from x=0.50 -0.90) show an increase in hydrogen storage capacity of more than 5-20% as compared to their bulk equivalents using even higher discharge rates. The maximum reversible hydrogen storage capacity at the optimal composition (Mg 80 Sc 20 ) amounts to 1795-bar mAh/g corresponding to a hydrogen content of 2.05 H/M or 6.7-bar wt.%, which is close to five times that of the commonly used hydride-forming materials in commercial NiMH batteries. Galvanostatic intermittent titration technique (GITT) measurements show that the equilibrium pressure during discharge is lower than that of bulk powders by one order of magnitude (10 -7 -bar mbar versus 10 -6 -bar mbar, respectively)

  17. The spectrum of four times ionized scandium, Sc V

    International Nuclear Information System (INIS)

    Smitt, R.; Ekberg, J.O.

    1985-01-01

    The spectrum of four times ionized scandium emitted from a sliding spark discharge has been observed using a 3 m normal incidence spectrograph and a 5 m grazing incidence spectrograph. About 450 lines in the wavelength region 160 A to 220 A have been identified as combinations between 46 odd levels belonging to the 3s 2 3p 5 , 3s 2 3p 4 4p and 3s3p 5 3d configurations and 72 even levels of the 3s3p 6 , 3s 2 3p 4 3d, 4d, 4s and 5s configurations. Of the previous identifications we have confirmed 18 levels. The level structure of the observed configurations has been theoretically interpreted by including configuration interaction effects. The inclusion of 3s 2 3p 3 3d 2 in the calculations of the odd parity configurations is found to be important. Almost all levels of 3s3p 5 3d show a considerable mixing with levels of 3s 2 3p 3 3d 2 , in some cases by as much as 50%. The energy parameters determined from least-squares fits to the observed level values are compared with Hartree-Fock calculations. The ionization energy is estimated to be 739 500 +- 1000 cm -1 . (91.65 +- 0,12 eV). (orig.)

  18. Aluminum-Scandium: A Material for Semiconductor Packaging

    Science.gov (United States)

    Geissler, Ute; Thomas, Sven; Schneider-Ramelow, Martin; Mukhopadhyay, Biswajit; Lang, Klaus-Dieter

    2016-10-01

    A well-known aluminum-scandium (Al-Sc) alloy, already used in lightweight sports equipment, is about to be established for use in electronic packaging. One application for Al-Sc alloy is manufacture of bonding wires. The special feature of the alloy is its ability to harden by precipitation. The new bonding wires with electrical conductivity similar to pure Al wires can be processed on common wire bonders for aluminum wedge/wedge (w/w) bonding. The wires exhibit very fine-grained microstructure. Small Al3Sc particles are the main reason for its high strength and prevent recrystallization and grain growth at higher temperatures (>150°C). After the wire-bonding process, the interface is well closed. Reliability investigations by active power cycling demonstrated considerably improved lifetime compared with pure Al heavy wires. Furthermore, the Al-Sc alloy was sputter-deposited onto silicon wafer to test it as chip metallization in copper (Cu) ball/wedge bonding technology. After deposition, the layers exhibited fine-grained columnar structure and small coherent Al3Sc particles with dimensions of a few nanometers. These particles inhibit softening processes such as Al splashing in fine wire bonding processes and increase the thickness of remnant Al under the copper balls to 85% of the initial thickness.

  19. Thermomechanical treatment of welded joints of aluminum-lithium alloys modified by scandium

    Science.gov (United States)

    Malikov, A. G.

    2017-12-01

    At present, the aeronautical equipment manufacture involves up-to-date high-strength aluminum alloys of decreased density resulting from the lithium admixture. Various technologies of fusible welding of these alloys are being developed. The paper presents experimental investigations of the optimization of the laser welding of aluminum alloys with the scandium-modified welded joint after thermomechanical treatment. The effect of scandium on the micro- and macrostructure is studied along with strength characteristics of the welded joint. It is found that thermomechanical treatment allows us to obtain the strength of the welded joint 0.89 for the Al-Mg-Li system and 0.99 for the Al-Cu-Li system with the welded joint modified by scandium in comparison with the base alloy after treatment.

  20. The enthalpy of solid scandium in the temperature range 406 - 1812 K

    International Nuclear Information System (INIS)

    Lyapunov, K.M.; Baginskij, A.V.; Stankus, S.V.

    2001-01-01

    Enthalpy of pure scandium was measured on massive calorimeter in the range from 406 to 1812 K by mixing method. The enthalpy of face centered close cubic lattice - body centered cubic lattice transformation is equal to ΔH t 4068 J/mol. Obtained value within the limits of error is compatible with the results given earlier (4009 J/mol). The dependence of the middle specific heat of scandium C p (T) on the temperature was shown in correlation with the results of other works. The results of the conducted experiments reinforce the conclusion made earlier about an absence (or a little) in the decomposition of an anharmonic component of the oscillation specific heat of scandium C p a (T) members proportional to the first or the second degrees of temperature [ru

  1. Biamperometric analysis of nonaqueous scandium solutions containing lanthanides, lead and thorium

    International Nuclear Information System (INIS)

    Gevorgyan, A.M.; Talipov, Sh.T.; Kostylev, V.S.; Khadeev, V.A.; Nadol'skij, M.Ya.

    1978-01-01

    Investigated was a possibility of direct scandium titration in the presence of large rare earth quantities, and also a possibility of complexonometric scandium and rare earth sum determination at their joint presence in non-aqueous acetic acid solution. The titration was carried out at electrode voltage of 0.95V, background electrolyte concentration of lithium perchlorate being 0.2M. Non-aqueous magnesium complexonate was used as titrating reagent. Th and Pb complexonates are shown to be less stable as compared to Sc complexonate, and consequently, Th and Pb ions must not interfere with biamperometric titration of Sc ion. A method applied to analysis of binary mixture, containing scandium, and a method for model alloy and thortveitite mineral was developed. Well reproducible and precise enough results are obtained in all the cases. Ions of Bi, Cu, Cd, Zn, In, Ga and Ti interfere with determination

  2. Pressure-induced structural change from hexagonal to fcc metal lattice in scandium trihydride

    International Nuclear Information System (INIS)

    Ohmura, A.; Machida, A.; Watanuki, T.; Aoki, K.; Nakano, S.; Takemura, K.

    2007-01-01

    We synthesized scandium hydrides by hydrogenation of a scandium foil with hydrogen fluid under high pressure at ambient temperature. Scandium dihydride (ScH 2 ) and trihydride (ScH 3 ) were prepared near 4 and 5 GPa, respectively. The hydrogenation process and pressure-induced structural changes in ScH 3 were investigated by synchrotron radiation X-ray diffraction measurements up to 54.7 GPa. A structural transition from hexagonal to the fcc lattice began at 30 GPa and was completed at 46 GPa via an intermediate state similar to those reported for other hexagonal trihydrides. The intermediate state was not interpreted in terms of a coexisting state for the low-pressure hexagonal and the high-pressure fcc structures. The onset transition pressure of ScH 3 supported the previously proposed relation that the hexagonal-fcc transition pressure is inversely proportional to the ionic radius of the trihydride

  3. Bonding in scandium monosulfide a NaCl crystal type

    International Nuclear Information System (INIS)

    Merrick, J.A.

    1980-08-01

    The transition temperature of an order-disorder transition in Sc 0 81 S (R anti 3m to Fm3m) occurs at 700 0 C. A group of ordered sublattices on the NaCl-type lattice (Fm3m) was generated and a Madelung energy and configurational entropy were calculated for each sublattice assuming the ions to be Sc 2 48+ and S 2- . Mean field and pair interaction approximations were used to model long-range and short-range orderings, respectively. The electrostatic model fails to predict the observed short-range and long-range orderings. The high temperature vaporization of ScP was investigated by mass spectrometry and target collection Knudsen effusion at 1767 to 2209K. The composition ScP 1 00 vaporizes congruently to the gaseous species Sc, P, and P 2 . A temperature independent third law enthalpy of atomization (ΔH 0 /sub atom,298/ = 252.2 +- 2.8 kcal mole -1 ) has a value approx. 12 kcal larger than that reported for ScS. Nonrelativistic, nonself-consistent LAPW band structure calculations are reported for ScS. XPS and UPS measurements are reported for Sc 2 S 3 and several compositions Sc/sub 1-x/S (0.0 less than or equal to x less than or equal to 0.2). The Sc and S 2p binding energies (XPS) obtained for the defect scandium monosulfides are very close to those found in the pure elements, suggesting covalent bonding. The Sc 2p energy region has an interesting satellite structure

  4. The effects of aluminum or scandium on the toughness, density and ...

    African Journals Online (AJOL)

    The effects of the substitution of aluminum or scandium on the density, toughness as well as the stability of the phases formed by such an addition on platinum, iridium, rhodium and palladium metals were evaluated with the density functional quantum mechanical calculation methods. All the metals had four atoms per ...

  5. In situ observation of the reaction of scandium and carbon by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Juarez-Arellano, Erick A., E-mail: eajuarez@unpa.edu.m [Institut fuer Geowissenschaften, Universitaet Frankfurt, Altenhoeferallee 1, 60438 Frankfurt a.M. (Germany); Universidad del Papaloapan, Circuito Central 200, Parque Industrial, Tuxtepec 68301 (Mexico); Winkler, Bjorn [Institut fuer Geowissenschaften, Universitaet Frankfurt, Altenhoeferallee 1, 60438 Frankfurt a.M. (Germany); Vogel, Sven C. [Los Alamos National Laboratory, Lujan Center. Mail Stop H805, Los Alamos, NM 87545 (United States); Senyshyn, Anatoliy [Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universitaet Muenchen, Lichtenbergstr. 1, D-85747 Garching (Germany); Materialwissenschaft, TU Darmstadt, Petersensstr. 23, D-64287 Darmstadt (Germany); Kammler, Daniel R. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Avalos-Borja, Miguel [CNyN, UNAM, A. Postal 2681, Ensenada, B.C. (Mexico)

    2011-01-05

    Research highlights: {yields} Exist two ScC cubic phases with B1-structure type differing in site occupancy of C. {yields} A new orthorhombic scandium carbide phase is formed at 1473(50) K. {yields} The recrystallization of alpha-Sc occurs between 1000 and 1223 K. - Abstract: The formation of scandium carbides by reaction of the elements has been investigated by in situ neutron diffraction up to 1823 K. On heating, the recrystallization of {alpha}-Sc occurs between 1000 and 1223 K. The formation of Sc{sub 2}C and ScC (NaCl-B1 type structure) phases has been detected at 1323 and 1373 K, respectively. The formation of a new orthorhombic scandium carbide phase was observed at 1473(50) K. Once the scandium carbides are formed they are stable upon heating or cooling. No other phases were detected in the present study, in which the system was always carbon saturated. The thermal expansion coefficients of all phases have been determined, they are constant throughout the temperature interval studied.

  6. Process Design Aspects for Scandium-Selective Leaching of Bauxite Residue with Sulfuric Acid

    OpenAIRE

    Konstantinos Hatzilyberis; Theopisti Lymperopoulou; Lamprini-Areti Tsakanika; Klaus-Michael Ochsenkühn; Paraskevas Georgiou; Nikolaos Defteraios; Fotios Tsopelas; Maria Ochsenkühn-Petropoulou

    2018-01-01

    Aiming at the industrial scale development of a Scandium (Sc)-selective leaching process of Bauxite Residue (BR), a set of process design aspects has been investigated. The interpretation of experimental data for Sc leaching yield, with sulfuric acid as the leaching solvent, has shown significant impact from acid feed concentration, mixing time, liquid to solids ratio (L/S), and number of cycles of leachate re-usage onto fresh BR. The thin film diffusion model, as the fundamental theory for l...

  7. Diagrammatic Representation of Electronic Correlations in Photoionization Process: Application to Scandium

    International Nuclear Information System (INIS)

    Liu Mengmeng; Ma Xiaoguang

    2011-01-01

    The conversion rules under which an algebraic expression can be obtained from a corresponding photoionization Goldstone diagram have been given systematically in the present work. The electronic correlations in the photoionization processes then could be studied diagrammatically. The application to atomic scandium shows that the present theoretical scheme can give reasonable photoionization cross sections, which agree well with the experimental results. (atomic and molecular physics)

  8. Pilot-scale recovery of rare earths and scandium from phosphogypsum and uranium leachates

    Directory of Open Access Journals (Sweden)

    Mashkovtsev Maxim

    2016-01-01

    Full Text Available Ural Federal University (UrFU and VTT have performed joint research on development of industrial technologies for the extraction of REM and Scandium compounds from phosphogypsum and Uranium ISL leachate solutions. Leaching-absorption experiments at UrFU have been supported with multicomponent solution modelling by VTT. The simulations have been performed with VTT’s ChemSheet/Balas program and can be used for speciation calculations in the lixiviant solution. The experimental work combines solvent extraction with advanced ion exchange methodology in a pilot facility capable of treating 5 m3 solution per hour. Currently, the plant produces cerium carbonate, lanthanum oxide, neodymium oxide and concentrate of heavy rare earth metals. A batch of 45 t solids has been processed with the gain of 100 kg’s of REM concentrate. A mini-pilot plant with productivity above 50 liters per hour has been applied to recover scandium oxide and REE concentrates from the uranium ISL solution. As the preliminary product contains radioactivity (mainly strontium, an additional decontamination and cleaning of both concentrates by extraction has rendered a necessity. Finally a purified 99% concentrate of scandium oxide as well as 99% rare earth concentrate are received.

  9. Effect of scandium on the phase composition and mechanical properties of ABM alloys

    Science.gov (United States)

    Molchanova, L. V.

    2010-09-01

    The effect of scandium on the composition and mechanical properties of ABM-1 alloys (Al-30% Be-5% Mg) is studied. The scandium content is varied from 0.1 to 0.5 wt %. It is established that, in the studied part of the Al-Be-Mg-Sc system, an aluminum solid solution (Al) and the ScBe13 compound are in equilibrium with a beryllium solid solution (Be). Magnesium dissolves in both the aluminum component and the ScBe13 compound. The strengthening effect related to the decomposition of the solid solution and the precipitation of Al3Sc cannot be extended to the strengthening of ABM-type alloys. Additions of 0.1-0.15 wt % Sc only weakly improve the mechanical properties of the alloys due to the refinement of beryllium-component grains. At high scandium contents, the strength increases insignificantly due to primary precipitation of ScBe13 and the plasticity decreases simultaneously.

  10. Influence of scandium on the pitting behaviour of Al-Zn-Mg-Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wloka, J. [Department of Materials Sciences, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany); Virtanen, S. [Department of Materials Sciences, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany)], E-mail: virtanen@ww.uni-erlangen.de

    2007-11-15

    In this paper the influence of small scandium additions (<0.26 wt.%) on the corrosion properties of the high-strength Al-Zn-Mg-Cu alloy AA7010 is investigated. The addition of scandium (in combination with the grain refiner Zr) leads to the formation of Al{sub 3}Sc{sub x}Zr{sub 1-x} phases. These coarse particles disturb the grain structure near the particle/matrix interface, which facilitates the initiation of localized corrosion in potentio-dynamic scans. Microelectrochemical investigations revealed a slightly cathodic character of these particles and a passive range beyond the breakdown potential of the matrix. Mass loss measurements show that the addition of scandium increases the mass loss during the initial period. The corrosion morphology was investigated with optical and scanning electron microscopy. The composition of the phases was determined with energy-dispersive X-ray analysis. Micro-capillary measurements were performed to investigate the electrochemical properties of single phases surrounded by matrix.

  11. Hardening mechanisms of spray formed Al-Zn-Mg-Cu alloys with scandium and other elemental additions

    International Nuclear Information System (INIS)

    Sharma, M.M.; Amateau, M.F.; Eden, T.J.

    2006-01-01

    The hardening mechanisms in spray formed Al-Zn-Mg-Cu alloys with additions of chromium, zinc and scandium were studied. The microstructure of the spray formed alloys was analyzed by transmission electron microscopy. A range of tensile strengths were achieved, and varied based on elemental additions, and second phase particle strengthening. To explain the significantly higher strength in one alloy with scandium, theoretical results due to the yield stress of Al-Zn-Mg-Cu alloys as a function of volume fraction and precipitate particle size, were compared to experimental data. Both the possibilities of coherency and order strengthening are examined. The significant additional hardening achieved in the alloy with scandium is attributed to small ordered particles of Al 3 Sc, which precipitated during aging

  12. Potential for photocatalytic degradation of the potassic diclofenac using scandium and silver modified titanium dioxide thin films

    International Nuclear Information System (INIS)

    Ciola, R.A.; Oliveira, C.T.; Lopes, S.A.; Cavalheiro, A.A.

    2011-01-01

    The potential for photocatalytic degradation of the potassic diclofenac drug was investigated using titanium dioxide thin films modified with two modifier types, scandium and silver, both prepared by Sol-Gel method. It was demonstrated by UVVis spectroscopy analysis of the solutions containing the drug, under UV-A light irradiation that the degradation efficiency of the titanium dioxide photocatalyst is dependent of the semiconductor nature and that the scandium accelerates the first step of the degradation when compared to the silver. This result seems to be related to the redox potential of the electron-hole pair, once the scandium modifying sample generates a p type semiconductor that reduces the band gap. The extra holes attract more strongly the chorine ion present in diclofenac and leading to the releasing more easily. However, after the first byproducts degradation the following steps are not facilitated, making the silver modifying more advantageous. (author)

  13. The influence of the diluent nature on scandium extraction by the phenol-formaldehyde resol oligomer yarrezin B

    International Nuclear Information System (INIS)

    Semenov, S.A.; Valkina, E.M.; Reznik, A.M.

    1996-01-01

    The paper studies the effect of diluent nature on scandium extraction by Yarrezin B phenol-formaldehyde resol oligomer using n-octan, toluene, chloroform, n-octanol and kerosene as an example. Correlation coefficients of dependences of scandium distribution factor on some parameters of diluents are calculated. Possibility to use some parameters of diluents to predict their effect on extraction indices is determined. Hildebrandt solubility parameter of extracting agent and parameters of extracting agent-diluent interaction according to Flory-Haggins are calculated. 13 refs., 2 figs., 4 tabs

  14. Determination of aluminium, scandium and rare earth elements by emission flame spectrometry

    International Nuclear Information System (INIS)

    Otruba, V.; Sommer, L.

    1989-01-01

    Emission spectrometry in nitrous oxide-acetylene flames in combination with a highly resolving double monochromator and sensitive detecting system enables simple, sensitive and selective determinations of aluminium, scandium and all rare earth elements with exception of cerium in complicated matrices. Calibration plots are linear for a large concentration interval (≤ 100 μgxml -1 ), detection limits are in ngxml -1 level and RSD does not exceed 3% on the optimal concentration level of the particular element. The determination of Al, Sc, Eu and Yb showed particular advantages as to methods using ICP-spectrometry. (orig.)

  15. 3He release characteristics of metal tritides and scandium--tritium solid solutions

    International Nuclear Information System (INIS)

    Perkins, W.G.; Kass, W.J.; Beavis, L.C.

    1975-01-01

    Tritides of such metals as scandium, titanium, and erbium are useful materials for determining the effects of helium accumulation in metallic solids, for example, CTR first wall materials. Such effects include lattice strain and gross deformation, as reported elsewhere, which are related to 3 He retention and ultimate release. Long term gas release studies have indicated that, during the early life of a metal ditritide, a large fraction of the 3 He is retained in the solid. At more advanced ages (2 to 4 years, depending on the parent metal), the 3 He release rate becomes comparable to the generation rate. Statistical analysis of the data indicates that the acceleration in 3 He release rate depends on accumulated 3 He concentration rather than strictly on age. 3 He outgassing results are presented for thin films of ScT 2 , TiT 2 , and ErT 2 , and the critical 3 He concentrations are discussed in terms of a percolation model. Phase transformations which occur on tritide formation cast some doubt on the validity of extrapolating results obtained for metal tritides to predictions regarding the accumulation of helium in metals. Scandium is unique among the early transition and rare-earth metals in that the metal exhibits a very high room temperature tritium solubility (T/Sc = 0.4) with no phase transformation. Indeed, even the lattice parameters of the hcp scandium lattice are only minimally changed by tritium solution, and we have succeeded in obtaining single crystal ScT 0 . 3 samples in two crystallographic orientations. Using a very sensitive technique, we have measured 3 He emission from both these samples, as well as from fine-grained thin film scandium-tritium solid solution samples (ScT 0 . 3 - 0 . 4 ). The fine-grained film samples release 3 He at 2 to 3 percent of the generation rate, while the emission rate from the single-crystal samples is approximately 0.05 percent of the generation rate, indicating a strong grain size effect

  16. Scandium-doped zinc cadmium oxide as a new stable n-type oxide thermoelectric material

    DEFF Research Database (Denmark)

    Han, Li; Christensen, Dennis Valbjørn; Bhowmik, Arghya

    2016-01-01

    Scandium-doped zinc cadmium oxide (Sc-doped ZnCdO) is proposed as a new n-type oxide thermoelectric material. The material is sintered in air to maintain the oxygen stoichiometry and avoid instability issues. The successful alloying of CdO with ZnO at a molar ratio of 1 : 9 significantly reduced...... is a good candidate for improving the overall conversion efficiencies in oxide thermoelectric modules. Meanwhile, Sc-doped ZnCdO is robust in air at high temperatures, whereas other n-type materials, such as Al-doped ZnO, will experience rapid degradation of their electrical conductivity and ZT....

  17. Scandium sorption by immobilized microdispersed forms of phosporus-containing ion exchangers

    International Nuclear Information System (INIS)

    Sokolova, Yu.V.; Kurdyumov, G.M.; Smirnov, A.V.; Mezhirov, M.S.

    1991-01-01

    The possibility to improve considerably kinetics of scandium sorption by phosphate ion exchangers, immobilized into polyacrylonitrile (PAN) fibers, as compared with granular samples of ion exchangers, was shown. The influence of dispersion degree of immobilized ionite particles on sorption rate was studied. It is ascertained that the ionite grinding to the particle size ≤ 52 μm is sufficient for the rate increase by 1-1.5 orders. A lower swelling of the immobilized ion exchanger is its additional advantage as compared with granular form

  18. Radiopharmaceuticals based on the scandium or rhodium radionuclides

    International Nuclear Information System (INIS)

    Majkowska, A.; Pruszynski, M.; Bilewicz, A.

    2006-01-01

    Radionuclides 103m Rh, 105 Rh emitting β-radiation or 47 Sc (Auger electrons emitter) are suitable for treatment small tumors spread over the human tissues. Presented communication describes preliminary results obtained in the Institute of Nuclear Chemistry and Technology, Warsaw (Poland) in the field of obtaining new complexes containing the aforementioned radionuclides. The radionuclides can be produced in the laboratory scale from simple and cheap generators. 103m Rh and 105 Rh cations were complexed with the thioetheric ligand (1,5,9,13-tetrathiacyclahexadecane-3,11-diole) and in the future, after funcionalization with certain biomolecules, are promising radiopharmaceuticals. 47 Sc cation was complexes by one from the following tri- or tetraaza macoryclic ligands: 1,4,7,10-triazacyclononane-1,4,7-triacetic acid (NOTA), 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (DO2A) or 1,4,7,10-triazacyclononane-1,4,7-triacetic acid (NOTA), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Composition and the stability constants of the complexes were determined

  19. Coordination compounds of scandium with dimethylsulfoxide and dimethylformamide

    International Nuclear Information System (INIS)

    Cherkasova, T.G.; Tatarinova, Eh.S.; Tryasunov, B.G.

    1991-01-01

    The possibility to prepare crystal coordination compounds in the systems ScCl 3 -K 3 [Cr(SCN) 6 ]-DMSO (DMFA) was studied. The complexes isolated were investigated by physicochemical methods. Their composition, behaviour in chemically agressive media, density, electric conductivity of solutions and magnetic susceptibility at 298 K were ascertained

  20. In the presence of fluoride, free Sc³⁺ is not a good predictor of Sc bioaccumulation by two unicellular algae: possible role of fluoro-complexes.

    Science.gov (United States)

    Crémazy, Anne; Campbell, Peter G C; Fortin, Claude

    2014-08-19

    We investigated the effect of fluoride complexation on scandium accumulation by two unicellular algae, Chlamydomonas reinhardtii and Pseudokirchneriella subcapitata. This trivalent metal was selected for its chemical similarities with aluminum and for its convenient radioisotope (Sc-46), which can be used as a tracer in short-term bioaccumulation studies. Scandium surface-bound concentrations (Sc(ads)) and uptake fluxes (J(int)) were estimated in the two algae over short-term (organisms.

  1. Polar and chemical domain structures of lead scandium tantalate (PST)

    International Nuclear Information System (INIS)

    Peng, J.L.; Bursill, L.A.

    1993-01-01

    The local structure of chemical and polar domains and domain walls is determined directly by atomic resolution high-resolution electron microscopy. Thus the Pb, Ta and Sc atomic positions may be located in the images of very thin crystals. Furthermore the Pb cation displacements away from the ideal perovskite A-site have been measured directly for the first time. Local variations in polarization direction may be mapped directly off the images, provided certain electron optical conditions are met. The results are relevant to recent theories of polar-glass behaviour in relaxor-type complex oxide functional ceramics. 17 refs., 9 figs

  2. Binary and ternary chelates of scandium (III), Yttrium (III) and lanthanum (III) with ethyleneglycol-bis(. beta. -aminoethylether)-tetraacetic acid as primary and substituted salicylic acids as secondary ligands

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, A K; Chandra, M; Agarwala, B V; Dey, A K [Allahabad Univ. (India). Chemical Labs.

    1980-01-01

    Formation constants of binary and ternary complexes of the systems of the type: M-L and M-egta-L (M = scandium(III), yttrium(III) and lanthanum(III), egta = ethylene glycol-bis(..beta..-aminoethylether)-tetra acetic acid, L = o-cresotic acid (o-ca), m-cresotic acid (m-ca), 5-chlorosalicyclic acid(csa), and 3,5-dibromosalicylic acid (dbsa)) have been determined pH-metrically at 25deg and ..mu.. = 0.1M (KNO/sub 3/) in 50% (v/v) aqueous-ethanol medium. The order of stabilities of ternary complexes has been compared with those of corresponding binary complexes, and results discussed on the basis of coulombic interactions.

  3. Why does the lumen maintenance of sodium-scandium metal halide lamps improve by VHF operation?

    International Nuclear Information System (INIS)

    Van Erk, W; Luijks, G M J F; Hitchcock, W

    2011-01-01

    Lifetime experiments show that sodium-scandium metal halide lamps perform better on very high frequency (VHF) drivers than on low frequency (LF) constant wattage autotransformer (CWA) ballasts. The question why, will be addressed with focus on arc tube aspects. It is argued that at high frequency operation sodium loss is less, and that the absence of thermal fluctuations in the electrode tip causes less damage and cracking to this part of the electrode. Sudden lm W -1 drops, observed with CWA-operated lamps, most probably occur when the arc attaches on such a corroded and cracked surface. Thorium is effective as an emitter both in the CWA and the VHF operation mode, despite the absence of cataphoretic transport to the cathode in the VHF case.

  4. Why does the lumen maintenance of sodium-scandium metal halide lamps improve by VHF operation?

    Energy Technology Data Exchange (ETDEWEB)

    Van Erk, W [Philips Lighting, Sondervick 47, 5505 NB Veldhoven (Netherlands); Luijks, G M J F [Advanced Development Lighting, Philips Lighting, PO Box 80020, 5600 JM Eindhoven (Netherlands); Hitchcock, W, E-mail: Gerard.luijks@philips.com [Philips Lighting Company, 7265 Route 54, Bath, NY 14810 (United States)

    2011-06-08

    Lifetime experiments show that sodium-scandium metal halide lamps perform better on very high frequency (VHF) drivers than on low frequency (LF) constant wattage autotransformer (CWA) ballasts. The question why, will be addressed with focus on arc tube aspects. It is argued that at high frequency operation sodium loss is less, and that the absence of thermal fluctuations in the electrode tip causes less damage and cracking to this part of the electrode. Sudden lm W{sup -1} drops, observed with CWA-operated lamps, most probably occur when the arc attaches on such a corroded and cracked surface. Thorium is effective as an emitter both in the CWA and the VHF operation mode, despite the absence of cataphoretic transport to the cathode in the VHF case.

  5. Influence of scandium on the microstructure and mechanical properties of A319 alloy

    International Nuclear Information System (INIS)

    Emadi, Daryoush; Rao, A.K. Prasada; Mahfoud, Musbah

    2010-01-01

    Recycling of aluminum scrap alloys by melting is gaining its importance in foundry sector. During recycling, some of the alloying elements present in scrap alloys eventually become trace/tramp impurities in the recycled alloy. These elements could potentially affect the alloy's microstructure and hence its mechanical properties. In the present work, an attempt has been made to investigate the effect of one of such trace elements on the microstructure and mechanical properties of A319 alloy. The element chosen for the present investigation is scandium (Sc). This paper discusses the effects of the additions of trace amount of Sc on the microstructure and mechanical properties of A319 alloy in as-cast, T6 and T7 heat treated conditions.

  6. Thermodynamic study of sublimation, melting and vaporization of scandium(III) dipivaloylmethanate derivatives

    International Nuclear Information System (INIS)

    Zherikova, Kseniya V.; Zelenina, Ludmila N.; Chusova, Tamara P.; Gelfond, Nikolay V.; Morozova, Natalia B.

    2016-01-01

    Highlights: • Thermal properties of two volatile fluorinated Sc(III) beta-diketonates were studied. • Saturated and unsaturated vapor pressures were measured. • DSC analysis was carried out. • Sublimation, evaporation and melting enthalpies and entropies were derived. • Effect of fluorine introduction on volatility and thermal stability was established. - Abstract: The present work deals with the investigation of thermal properties of two volatile scandium(III) beta-diketonates with 2,2,6,6-tetramethyl-4-fluoro-3,5-heptanedione and 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione which have been synthesized and purified. Using the static method with glass membrane gauge-manometer the temperature dependencies of saturated and unsaturated vapor pressure were measured for the first time. The temperatures and enthalpies of melting were measured for these compounds by differential scanning calorimetry. The standard thermodynamic characteristics of enthalpy and entropy for sublimation, vaporization and melting processes were derived.

  7. Dielectric matrix, dynamical matrix and phonon dispersion in hcp transition metal scandium

    International Nuclear Information System (INIS)

    Singh, Joginder; Singh, Natthi; Prakash, S.

    1976-01-01

    Complete dielectric matrix is evaluated for hcp transition metal scandium using the non-interacting s- and d-band model. The local field corrections which are consequence of the non-diagonal part of the dielectric matrix are calculated explicitly. The free electron approximation is used for the s-electrons and the simple tight-binding approximation is used for the d-electrons. The theory developed by Singh and others is used to invert the dielectric matrix and the explicit expressions for the dynamical matrix are obtained. The phonon dispersion relations are investigated by using the renormalized Animalu transition metal model potential (TMMP) for bare ion potential. The contribution due to non-central forces which arise due to local fields is found to be 20%. The results are found in resonably good agreement with the experimental values. (author)

  8. Bottom sediment transport study at Haiphong port using radioactive scandium as tracer

    International Nuclear Information System (INIS)

    Pham Ngoc Chuong; Phan Son Hai; Pham Duy Hien

    1993-01-01

    A radioisotope tracer experiment was performed for investigating the bedload movement at the site near the access channel to Haiphong port, North Vietnam. The scandium glass and a number of mechanical devices were manufactured locally for the experiment. Simple and safe procedures were adopted for the production, transportation and injection of radioactive tracer materials. Five tracking experiments were carried out covering the period of 84 days in winter 1992-1993. The experimental results provide a firm basis for elaborating appropriate measures against the siltation problem at Haiphong port, especially for the design of a new access channel with a better orientation with respect to the directions of the water flow and bedload transport, as proposed recently by the Port Authority. (Author). 2 refs, 4 figs

  9. Modification mechanism of eutectic silicon in Al–6Si–0.3Mg alloy with scandium

    Energy Technology Data Exchange (ETDEWEB)

    Patakham, Ussadawut [Manufacturing and Systems Engineering Program, Department of Production Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Rd., Bangmod, Tungkhru, Bangkok 10140 (Thailand); Kajornchaiyakul, Julathep [National Metal and Material Technology Center, National Science and Technology Development Agency, 114 Thailand Science Park, Klong Nueng, Klong Luang, Pathumthani 12120 (Thailand); Limmaneevichitr, Chaowalit, E-mail: chaowalit.lim@kmutt.ac.th [Manufacturing and Systems Engineering Program, Department of Production Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Rd., Bangmod, Tungkhru, Bangkok 10140 (Thailand)

    2013-10-25

    Highlights: •Morphologies and growth of Sc and Sr-modified eutectic silicon resemble those of dendrites. •Crystal orientation of eutectic aluminum depends on growth characteristics of eutectic silicon. •We report strong evidence of the occurrence of an impurity-induced twinning mechanism. -- Abstract: The modification mechanism of eutectic silicon in Al–6Si–0.3Mg alloy with scandium was studied. The crystallographic orientation relationships between primary dendrites and the eutectic phase of unmodified and modified Al–6Si–0.3 Mg alloys were determined using electron backscatter diffraction (EBSD). The orientation of aluminum modified with scandium in the eutectic phase was different from that of the neighboring primary dendrites. This result implies that eutectic aluminum grows epitaxially from the surrounding primary aluminum dendrites in the unmodified alloy and that eutectic aluminum grows competitively from the surrounding primary aluminum dendrites in the modified alloy. The pole figure maps of eutectic Si in the [1 0 0], [1 1 0] and [1 1 1] axes of the unmodified and Sc-modified alloys were different, suggesting that the eutectic Al and Si crystals in modified alloy growth are more isotropic and cover a larger set of directions. The lattice fringes of Si of the alloys with and without Sc modification were different in the TEM results. The lattice fringes of Si in modified alloy were found to be multiple twins. However, this was not observed in the unmodified alloy. The growth characteristic of eutectic Si crystal in modified alloy suggests the occurrence of multiple twinning reactions and the formation of a high density of twins. This modification mechanism by Sc is explained by the results of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analysis, which provide strong evidence of the occurrence of the impurity-induced twinning (IIT) mechanism.

  10. Insights into the mantle geochemistry of scandium from a meta-analysis of garnet data

    Science.gov (United States)

    Chassé, Mathieu; Griffin, William L.; Alard, Olivier; O'Reilly, Suzanne Y.; Calas, Georges

    2018-06-01

    The meta-analysis of about 13,000 analyses of scandium content in garnet grains shows that, below the spinel-garnet transition, this phase carries about three-quarters of the Sc budget of the mantle, indicating its control on Sc mobility. The Sc content of garnets in mafic rocks is low, due to a dilution effect resulting from their high modal content in garnet. Garnets from ultramafic rocks exhibit a wider range of Sc concentrations. We assess the relative influence of thermobarometry, crystal chemistry and fluid-related events on the distribution of Sc in garnet from such rocks to improve the tracking of geochemical processes in the mantle. Pressure and temperature of equilibration in the mantle are second-order factors influencing the Sc content of garnet, while crystal chemistry, in particular Cr/Cr+Al and Ca/Ca+Mg, is the main parameter controlling the compatibility of Sc. Scandium is incorporated in both X and Y sites of Cr-Ca-rich garnets, resulting in a behaviour intermediate between rare-earth elements, incorporated in the X site, and trivalent transition elements, occupying the Y site. This affinity for both sites results in a mild compatibility of Sc in the garnet stability field of the mantle; hence Sc concentration in garnet increases with melt extraction and can be reduced by silicate-melt metasomatism. In contrast, metasomatism by volatile-rich fluids increases the Sc concentration in garnet. The control of garnet on the compatibility of Sc in deep lithospheric rocks demonstrates the potential of using Sc to track the conditions of formation of magmas and their residual rocks, as well as the origin and nature of metasomatic fluids.

  11. Multiscale Study of Hydrogen Adsorption on Six Designed Covalent Organic Frameworks Based on Porphyrazine, Cyclobutane and Scandium

    International Nuclear Information System (INIS)

    Li Le-Le; Gao Teng-Fei; Zhang Ruan-Yu; Zhang Hong

    2014-01-01

    The first-principles method of hydrogen adsorption is used to investigate the interaction of H_2 with the scandium-porphyrazine (Sc-Pz) and porphyrazine (Pz) clusters. The result shows that the interaction of H_2 with Sc-Pz is stronger than with Pz. Then grand canonical Monte Carlo simulations are used to investigate hydrogen adsorption in six designed covalent organic frameworks (COFs), which are designed based on porphyrazine, cyclobutane and scandium. When the pressure is from 0.1 to 100 bar and the temperature is 298 K and 77 K, the hydrogen adsorption capacities of the six COFs are calculated. We further study the importance of Sc and fillers to improve the H_2 uptake in the modified COFs by analyzing the isosteric heat of hydrogen adsorption. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  12. Phenomenological theory of the dielectric response of lead magnesium niobate and lead scandium tantalate

    International Nuclear Information System (INIS)

    Qian, H.; Bursill, L.A.

    1997-01-01

    The influence of the random field effects originating from charges chemical defects and non-domain textures of the formation and dynamics of polar clusters is analyzed. The spatial distribution of the local fields is not totally random but contains some correlations in direction and strength. Polar clusters are classified to be dynamic or frozen according to their dynamic characteristics in the random fields. The relaxation formula of a dipolar moment in an anisotropic double-well potential is deduced. Two percolation models are introduced, one to account for frustration effects associated with multiple orientations of polar clusters, which results in a broad diffuse dielectric response and the second to account for the case whereby there may be a phase transition to a ferroelectric state. The dielectric permittivity and dissipation factor of the typical relaxors lead magnesium niobate and lead scandium tantalate are predicted as a function of both temperature and frequency, which results are in good agreement with the experimental measurements. 30 refs., 9 figs

  13. Microstructure and age-hardening effects of aluminium alloys with additions of scandium and zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Galun, R.; Mordike, B.L. [Inst. fuer Werkstoffkunde und Werkstofftechnik, Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany); Maiwald, T.; Smola, B. [Zentrum fuer Funktionswerkstoffe GmbH, Clausthal-Zellerfeld (Germany); Mergen, R.; Manner, M.; Uitz, W. [Miba Gleitlager GmbH, Laakirchen (Australia)

    2004-12-01

    The aim of the work presented in this report was to produce age-hardenable aluminium alloys containing scandium and zirconium by a casting process with similar cooling conditions like an industrial casting process. Microstructure, precipitation structure and age-hardening response of different alloys with up to 0.4 wt.% Sc and Zr were investigated. Age-hardening experiments from the as-cast condition without solution annealing showed a significant increase of hardness of about 100% for Sc-rich alloys and of 50% for Zr-rich alloys compared to the as-cast condition. TEM investigations revealed the formation of precipitates of ternary Al{sub 3}(Sc{sub x}Zr{sub 1-x}) phases with a cubic cP4 crystal structure. In addition to the strengthening effect, a high thermal stability especially of the precipitates in Zr-rich alloys up to 400 C let these alloys look very promising for high-temperature applications. (orig.)

  14. Adsorption of hydrogen in Scandium/Titanium decorated nitrogen doped carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Mananghaya, Michael, E-mail: mikemananghaya@gmail.com [De La Salle University, 2401 Taft Ave, 0922, Manila (Philippines); DLSU STC Laguna Boulevard, LTI Spine Road Barangays Biñan and Malamig, Biñan City, Laguna (Philippines); DOST-ASTHRDP, PCIEERD, Gen. Santos Ave., Bicutan, Taguig City 1631 (Philippines); Belo, Lawrence Phoa; Beltran, Arnel [De La Salle University, 2401 Taft Ave, 0922, Manila (Philippines); DLSU STC Laguna Boulevard, LTI Spine Road Barangays Biñan and Malamig, Biñan City, Laguna (Philippines)

    2016-09-01

    Nitrogen doped Carbon Nanotube with divacancy (4ND-CN{sub x}NT) that is decorated with Scandium and Titanium as potential hydrogen storage medium using the pseudo potential density functional method was investigated. Highly localized states near the Fermi level, which are derived from the nitrogen defects, contribute to strong Sc and Ti bindings, which prevent metal aggregation and improve the material stability. A detailed Comparison of the Hydrogen adsorption capability with promising system-weight efficiency of Sc over Ti was elucidated when functionalized with 4ND-CN{sub x}NT. Finally, the (Sc/4ND){sub 10}-CN{sub x}CNT composite material has a thermodynamically favorable adsorption and consecutive adsorption energy for ideal reversible adsorption and desorption of hydrogen at room temperature such that it can hold at least 5.8 wt% hydrogen molecules at the LDA and GGA level. - Highlights: • Carbon Nanotube with divacancy (4ND-CN{sub x}NT) decorated with Sc and Ti. • Nitrogen defects, contribute to strong Sc and Ti bindings. • H{sub 2} and (Sc/4ND){sub 10}-CN{sub x}CNT has a favorable adsorption. • 5.8 wt% adsorption at the LDA and GGA level.

  15. Influence of scandium on the microstructure and strength properties of the welded joint at the laser welding of aluminum-lithium alloys

    Science.gov (United States)

    Malikov, A. G.; Golyshev, A. A.; Ivanova, M. Yu.

    2017-10-01

    Today, aeronautical equipment manufacture involves up-to-date high-strength aluminum alloys of decreased density resulting from lithium admixture. Various technologies of fusible welding of these alloys are being developed. Serious demands are imposed to the welded joints of aluminum alloys in respect to their strength characteristics. The paper presents experimental investigations of the optimization of the laser welding of aluminum alloys with the scandium-modified welded joint. The effect of scandium on the micro-and macro-structure has been studied as well as the strength characteristics of the welded joint. It has been found that scandium under in the laser welding process increases the welded joint elasticity for the system Al-Mg-Li, aluminum alloy 1420 by 20 %, and almost doubles the same for the system Al-Cu-Li, aluminum alloy 1441.

  16. Interaction of scandium and titanium atoms with a carbon surface containing five- and seven-membered rings

    International Nuclear Information System (INIS)

    Krasnov, P. O.; Eliseeva, N. S.; Kuzubov, A. A.

    2012-01-01

    The use of carbon nanotubes coated by atoms of transition metals to store molecular hydrogen is associated with the problem of the aggregation of these atoms, which leads to the formation of metal clusters. The quantum-chemical simulation of cluster models of the carbon surface of a graphene type with scandium and titanium atoms has been performed. It has been shown that the presence of five- and seven-membered rings, in addition to six-membered rings, in these structures makes it possible to strongly suppress the processes of the migration of metal atoms over the surface, preventing their clustering.

  17. Magnetic susceptibility of scandium-hydrogen and lutetium-hydrogen solid-solution alloys from 2 to 3000K

    International Nuclear Information System (INIS)

    Stierman, R.J.

    1982-12-01

    Results for pure Sc show that the maximum and minimum in the susceptibility discovered earlier are enhanced as the impurity level of iron in scandium decreases. The Stoner enhancement factor, calculated from low-temperature heat capacity data, susceptibility data, and band-structure calculations show Sc to be a strongly enhanced paramagnet. Below 2 0 K, the magnetic anisotropy between the hard and easy directions of scandium decreases linearly with decreasing temperature, tending toward zero at 0 K. The large increase in the susceptibility of Sc at lower temperatures indicates magnetic ordering. Pure Lu and Lu-H alloys showed an anisotropy in susceptibility vs orientation; thus the samples were not random polycrystalline samples. Pure Lu shows the shallow maximum and minimum, but the increase in susceptibility at low temperatures is larger than previously observed. The susceptibility-composition dependence of the Lu-H alloys also did not match other data. The susceptibility-composition dependence does not match the composition dependence of the electronic specific heat constant below 150 K, showing the electronic specific heat is being affected by terms other than phonon-electron and pure electron-electron interactions

  18. Self-Assembled Nanocomposite Organic Polymers with Aluminum and Scandium as Heterogeneous Water-Compatible Lewis Acid Catalysts.

    Science.gov (United States)

    Miyamura, Hiroyuki; Sonoyama, Arisa; Hayrapetyan, Davit; Kobayashi, Shū

    2015-09-01

    While water-compatible Lewis acids have great potential as accessible and environmentally benign catalysts for various organic transformations, efficient immobilization of such Lewis acids while keeping high activity and without leaching of metals even under aqueous conditions is a challenging task. Self-assembled nanocomposite catalysts of organic polymers, carbon black, aluminum reductants, and scandium salts as heterogeneous water-compatible Lewis acid catalysts are described. These catalysts could be successfully applied to various C-C bond-forming reactions without leaching of metals. Scanning transmission electron microscopy analyses revealed that the nanocomposite structure of Al and Sc was fabricated in these heterogeneous catalysts. It is noted that Al species, which are usually decomposed rapidly in the presence of water, are stabilized under aqueous conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Scandium doping brings speed improvement in Sb2Te alloy for phase change random access memory application.

    Science.gov (United States)

    Chen, Xin; Zheng, Yonghui; Zhu, Min; Ren, Kun; Wang, Yong; Li, Tao; Liu, Guangyu; Guo, Tianqi; Wu, Lei; Liu, Xianqiang; Cheng, Yan; Song, Zhitang

    2018-05-01

    Phase change random access memory (PCRAM) has gained much attention as a candidate for nonvolatile memory application. To develop PCRAM materials with better properties, especially to draw closer to dynamic random access memory (DRAM), the key challenge is to research new high-speed phase change materials. Here, Scandium (Sc) has been found it is helpful to get high-speed and good stability after doping in Sb 2 Te alloy. Sc 0.1 Sb 2 Te based PCRAM cell can achieve reversible switching by applying even 6 ns voltage pulse experimentally. And, Sc doping not only promotes amorphous stability but also improves the endurance ability comparing with pure Sb 2 Te alloy. Moreover, according to DFT calculations, strong Sc-Te bonds lead to the rigidity of Sc centered octahedrons, which may act as crystallization precursors in recrystallization process to boost the set speed.

  20. Random-field Potts model for the polar domains of lead magnesium niobate and lead scandium tantalate

    Energy Technology Data Exchange (ETDEWEB)

    Qian, H.; Bursill, L.A

    1997-06-01

    A random filed Potts model is used to establish the spatial relationship between the nanoscale distribution of charges chemical defects and nanoscale polar domains for the perovskite-based relaxor materials lead magnesium niobate (PMN) and lead scandium tantalate (PST). The random fields are not set stochastically but are determined initially by the distribution of B-site cations (Mg, Nb) or (Sc, Ta) generated by Monte Carlo NNNI-model simulations for the chemical defects. An appropriate random field Potts model is derived and algorithms developed for a 2D lattice. It is shown that the local fields are strongly correlated with the chemical domain walls and that polar domains as a function of decreasing temperature is simulated for the two cases of PMN and PST. The dynamics of the polar clusters is also discussed. 33 refs., 9 figs.

  1. Modification of radiation sensitivity by salts of the metals beryllium and indium and the rare earths cerium, lanthanum and scandium

    International Nuclear Information System (INIS)

    Floersheim, G.L.

    1995-01-01

    The LD 50 of 46 salts of metals and rare earths (lanthanoids) was determined in mice. Half the LD 50 of the compounds was then combined with lethal radiation (10.5 Gy) and the modification of survival time was scored. Only the metals beryllium and indium and the rare earths cerium, lanthanum and scandium displayed activity in our assay. There were then tested at a wider range of lower doses and reduced survival time in a dose-dependent fashion. This appears to be compatible with enhancement of radiation sensitivity. The interaction of these metals and rare earths with radiation adds a new facet to their toxicological spectrum and, by enhancing radiation effects, may influence estimates of risk. On the other hand, radiosensitizing properties of the metals may be useful for further development of compounds to be used as adjuncts in specific situations of cancer radiotherapy. 31 refs., 1 fig., 1 tab

  2. Polymerization of lanthanide acrylonitrile complexes.

    Science.gov (United States)

    el-Mossalamy, El-Sayed H; Khalil, Ahmed A

    2002-01-01

    The molecular complexes of some lanthanides scandium (Sc3+), yttrium (Y3+), lanthanum (La3+), gadolinium (Gd3+), cerium (Ce3+) and ytterbium (Yb3) have been studies in dimethyl formamide (DMF) spectrophtometrically equilibrium constants (K), molar extintion coefficient (epsilon), energy of transition (E) and free energy (delta G*) were calculated. The polymerization of acrylonitrile has been studied and investigated in the presence of Sc3+, Y3+, La3+, Gd3+, Ce3+, and Yb3+ ions. The IR spectra of the formed AN-M (III) Br3 polymer complexes show the absence of the C identical to N band and the presence of two new bands corresponding to NH2 and OH groups. Magnetic moment values and the thermal stabilities of homopolymer and the polymer complexes were studied by means of thermogravimetric analysis and the activation energies for degradation were calculated.

  3. Study of strength properties of semi-finished products from economically alloyed high-strength aluminium-scandium alloys for application in automobile transport and shipbuilding

    Science.gov (United States)

    Baranov, Vladimir; Sidelnikov, Sergey; Zenkin, Evgeny; Frolov, Viktor; Voroshilov, Denis; Yakivyuk, Olga; Konstantinov, Igor; Sokolov, Ruslan; Belokonova, Irina

    2018-04-01

    The results of a study on the strength of rolled products from aluminium alloys doped with scandium under various processing conditions of hot and cold rolling are presented. The regularities of metal flow and the level of strength of deformed semi-finished products from aluminum-scandium alloys are established, depending on the total degree of deformation and the various modes of single reduction during rolling. It is shown that when using one heating of a cast billet to obtain high-quality semi-finished products, the temperature during the rolling process should not be lower than 350-370°, and the total degree of deformation does not exceed 50-60%. It was found that the semi-finished products from alloys with a content of scandium in the range 0.11-0.12% in the deformed state had elevated values of ultimate tensile strength and yield strength of the metal, which allows them to be recommended for industrial production of sheet metal products.

  4. Development of methods for the selective separation of scandium, zirconium and tin for radiopharmaceutical applications; Entwicklung von Methoden zur selektiven Trennung von Scandium, Zirkonium und Zinn fuer radiopharmazeutische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Dirks-Fandrei, Carina

    2014-07-01

    The subject of the present work is the development of fast and highly selective methods for the separation and purification of scandium, zirconium and tin radionuclides from potential target materials for use in nuclear medicine. A number of selected resins (TrisKem International) were first characterized with respect to their extraction behaviour towards a large number of cations. Characterization studies were performed in batch experiments by determination of weight distribution ratios D{sub w} and further the influence of interferences on the uptake of these elements was evaluated. Weight distribution ratios were determined in different acids and acid concentrations with main focus on scandium, tin or zirconium. The interference of macro amounts of Calcium and Ti on the Sc extraction was evaluated as well as the interference of macro amounts of Y on the Zr extraction. Best suited uptake conditions were found for Scandium on DGA were determined to be 2.5 M HNO{sub 3} for Ti-Targets and 0.1 M HNO{sub 3} for Calcium-Targets. Otherwise it is also possible to extract Sc with TRU Resin. High uptakes were obtained at 2.5 M HNO{sub 3} for simulated Ti- and Calcium-targets. Separation methods were developed using elution studies; employed conditions were chosen according to parameters evaluated in the batch-experiment. The developed methods allowed separating Sc very rapidly in high purity very rapidly from Ti- or Calcium-targets. For Zr a separation method based on UTEVA Resin has been developed. Following results of batch experiments simulated Y-target solution were loaded onto a UTEVA resin column from 6 M HNO{sub 3}; the elution of Zr could be performed in 0.01 M oxalic acid. Decontamination factors in the order of 10{sup 4}-10{sup 5} could be obtained applying the developed method; the method thus allowed separating Zr in a high purity. Initial testing of a method for the separation of Sn from Cd targets based on the use of TBP Resin showed that the TBP resin seems

  5. Thermal, spectroscopic and laser properties of Nd3+ in gadolinium scandium gallium garnet crystal produced by optical floating zone method

    Science.gov (United States)

    Tian, Li; Wang, Shuxian; Wu, Kui; Wang, Baolin; Yu, Haohai; Zhang, Huaijin; Cai, Huaqiang; Huang, Hui

    2013-12-01

    A neodymium-doped gadolinium scandium gallium garnet (Nd:GSGG) single crystal with dimensions of Φ 5 × 20 mm2 has been grown by means of optical floating zone (OFZ). X-ray powder diffraction (XRPD) result shows that the as-grown Nd:GSGG crystal possesses a cubic structure with space group Ia3d and a cell parameter of a = 1.2561 nm. Effective elemental segregation coefficients of the Nd:GSGG as-grown crystal were calculated by using X-ray fluorescence (XRF). The thermal properties of the Nd:GSGG crystal were systematically studied by measuring the specific heat, thermal expansion and thermal diffusion coefficient, and the thermal conductivity of this crystal was calculated. The absorption and luminescence spectra of Nd:GSGG were measured at room temperature (RT). By using the Judd-Ofelt (J-O) theory, the theoretical radiative lifetime was calculated and compared with the experimental result. Continuous wave (CW) laser performance was achieved with the Nd:GSGG at the wavelength of 1062 nm when it was pumped by a laser diode (LD). A maximum output power of 0.792 W at 1062 nm was obtained with a slope efficiency of 11.89% under a pump power of 7.36 W, and an optical-optical conversion efficiency of 11.72%.

  6. Potential for photocatalytic degradation of the potassic diclofenac using scandium and silver modified titanium dioxide thin films; Potencial de degradacao fotocatalitica do diclofenaco potassico utilizando filmes finos de dioxido de titanio modificado com escandio e prata

    Energy Technology Data Exchange (ETDEWEB)

    Ciola, R.A.; Oliveira, C.T.; Lopes, S.A.; Cavalheiro, A.A., E-mail: rafaelciola@hotmail.com [Universidade Estadual de Mato Grosso do Sul (UFMS), Navirai, MS (Brazil). Centro de Pesquisas Tecnologicas em Recursos Naturais

    2011-07-01

    The potential for photocatalytic degradation of the potassic diclofenac drug was investigated using titanium dioxide thin films modified with two modifier types, scandium and silver, both prepared by Sol-Gel method. It was demonstrated by UVVis spectroscopy analysis of the solutions containing the drug, under UV-A light irradiation that the degradation efficiency of the titanium dioxide photocatalyst is dependent of the semiconductor nature and that the scandium accelerates the first step of the degradation when compared to the silver. This result seems to be related to the redox potential of the electron-hole pair, once the scandium modifying sample generates a p type semiconductor that reduces the band gap. The extra holes attract more strongly the chorine ion present in diclofenac and leading to the releasing more easily. However, after the first byproducts degradation the following steps are not facilitated, making the silver modifying more advantageous. (author)

  7. Determination of rare-earth elements, yttrium and scandium in manganese nodules by inductively-coupled argon-plastma emission spectrometry

    Science.gov (United States)

    Fries, T.; Lamothe, P.J.; Pesek, J.J.

    1984-01-01

    A sequential-scanning, inductively-coupled argon plasma emission spectrometer is used for the determination of the rare-earth elements, plus yttrium and scandium, in manganese nodules. Wavelength selection is optimized to minimize spectral interferences from manganese nodule components. Samples are decomposed with mixed acids in a sealed polycarbonate vessel, and elements are quantified without further treatment. Results for U.S. Geological Survey manganese nodule standards A-1 and P-1 had average relative standard deviations of 6.8% and 8.1%, respectively, and results were in good agreement with those obtained by other methods. ?? 1984.

  8. Structural characteristics and physical properties of diortho(pyro)silicate crystals of lanthanides yttrium and scandium grown by the Czochralski technique

    Energy Technology Data Exchange (ETDEWEB)

    Anan' eva, G.V.; Karapetyan, V.E.; Korovkin, A.M.; Merkulyaeva, T.I.; Peschanskaya, I.A.; Savinova, I.P.; Feofilov, P.P. (Gosudarstvennyj Opticheskij Inst., Leningrad (USSR))

    1982-03-01

    Optically uniform monocrystals of diortho (pyro) silicates of lanthanides, yttrium, and scandium were grown by the Czochralski technique. Four structural types of Ln/sub 2/(Si/sub 2/O/sub 7/) crystals were determined by the roentgenographic method. The presence of structural subgroups was also supported by the method of spectroscopic probes. Structural parameters were determined and data on certain physical properties (fusion temperature, density, refractive indices, transparency) of investigated crystals were presented. The generation of induced emission at lambda=1.057 ..mu..m was obtained in La/sub 2/(Si/sub 2/O/sub 7/)-Nd/sup 3 +/ crystal.

  9. Determination of scandium in acid mine drainage by ICP-OES with flow injection on-line preconcentration using oxidized multiwalled carbon nanotubes.

    Science.gov (United States)

    Jerez, Javier; Isaguirre, Andrea C; Bazán, Cristian; Martinez, Luis D; Cerutti, Soledad

    2014-06-01

    An on-line scandium preconcentration and determination system implemented with inductively coupled plasma optical emission spectrometry associated with flow injection was studied. Trace amounts of scandium were preconcentrated by sorption on a minicolumn packed with oxidized multiwalled carbon nanotubes, at pH 1.5. The retained analyte was removed from the minicolumn with 30% (v/v) nitric acid. A total enrichment factor of 225-fold was obtained within a preconcentration time of 300 s (for a 25 mL sample volume). The overall time required for preconcentration and elution of 25 mL of sample was about 6 min; the throughput was about 10 samples per hour. The value of the detection limit was 4 ng L(-1) and the precision for 10 replicate determinations at 100 ng L(-1) Sc level was 5% relative standard deviation, calculated from the peak heights obtained. The calibration graph using the preconcentration system was linear with a correlation coefficient of 0.9996 at levels near the detection limits up to at least 10 mg L(-1). After optimization, the method was successfully applied to the determination of Sc in an acid drainage from an abandoned mine located in the province of San Luis, Argentina. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Effects of scandium and zirconium combination alloying on as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy

    Directory of Open Access Journals (Sweden)

    Xiang Qingchun

    2011-02-01

    Full Text Available The influences of minor scandium and zirconium combination alloying on the as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy have been experimentally investigated. The experimental results show that when the minor elements of scandium and zirconium are simultaneously added into the Al-4Cu-1.5Mg alloy, the as-cast microstructure of the alloy is effectively modified and the grains of the alloy are greatly refined. The coarse dendrites in the microstructure of the alloy without Sc and Zr additions are refined to the uniform and fine equiaxed grains. As the additions of Sc and Zr are 0.4% and 0.2%, respectively, the tensile strength, yield strength and elongation of the alloy are relatively better, which are 275.0 MPa, 176.0 MPa and 8.0% respectively. The tensile strength is increased by 55.3%, and the elongation is nearly raised three times, compared with those of the alloy without Sc and Zr additions.

  11. Scandium(III) catalysis of transimination reactions. Independent and constitutionally coupled reversible processes.

    Science.gov (United States)

    Giuseppone, Nicolas; Schmitt, Jean-Louis; Schwartz, Evan; Lehn, Jean-Marie

    2005-04-20

    Sc(OTf)(3) efficiently catalyzes the self-sufficient transimination reaction between various types of C=N bonds in organic solvents, with turnover frequencies up to 3600 h(-)(1) and rate accelerations up to 6 x 10(5). The mechanism of the crossover reaction in mixtures of amines and imines is studied, comparing parallel individual reactions with coupled equilibria. The intrinsic kinetic parameters for isolated reactions cannot simply be added up when several components are mixed, and the behavior of the system agrees with the presence of a unique mediator that constitutes the core of a network of competing reactions. In mixed systems, every single amine or imine competes for the same central hub, in accordance with their binding affinity for the catalyst metal ion center. More generally, the study extends the basic principles of constitutional dynamic chemistry to interconnected chemical transformations and provides a step toward dynamic systems of increasing complexity.

  12. Two anionically derivatized scandium oxoselenates(IV): ScF[SeO3] and Sc2O2[SeO3

    Science.gov (United States)

    Greiner, Stefan; Chou, Sheng-Chun; Schleid, Thomas

    2017-02-01

    Scandium fluoride oxoselenate(IV) ScF[SeO3] and scandium oxide oxoselenate(IV) Sc2O2[SeO3] could be synthesized through solid-state reactions. ScF[SeO3] was obtained phase-pure, by reacting mixtures of Sc2O3, ScF3 and SeO2 (molar ratio: 1:1:3) together with CsBr as fluxing agent in corundum crucibles embedded into evacuated glassy silica ampoules after firing at 700 °C for seven days. Sc2O2[SeO3] first emerged as by-product during the attempts to synthesize ScCl[SeO3] following aforementioned synthesis route and could later be reproduced from appropriate Sc2O3/SeO3 mixtures. ScF[SeO3] crystallizes monoclinically in space group P21/m with a=406.43(2), b =661.09(4), c=632.35(4) pm, β=93.298(3)° and Z=2. Sc2O2[SeO3] also crystallizes in the monoclinic system, but in space group P21/n with a=786.02(6), b=527.98(4), c=1086.11(8) pm, β=108.672(3)° for Z=4. The crystal structures of both compounds are strongly influenced by the stereochemically active lone pairs of the ψ1-tetrahedral [SeO3]2- anions. They also show partial structures, where the derivatizing F- or O2- anions play an important role. For ScF[SeO3] chains of the composition 2+∞ 1[FS c 2 / 2 ] form from connected [FSc2]5+ dumbbells, while [OSc3]7+ pyramids and [OSc4]10+ tetrahedra units are condensed to layers according to 2+ ∞ 2[O2Sc2 ] in Sc2O2[SeO3].

  13. Copper scandium zirconium phosphate

    DEFF Research Database (Denmark)

    Bond, Andrew David; Warner, Terence Edwin

    2013-01-01

    The title compound, with nominal formula Cu(2)ScZr(PO(4))(3), has a beige coloration and displays fast Cu(+) cation conduction at elevated temperatures. It adopts a NASICON-type structure in the space group R3c. The examined crystal was an obverse-reverse twin with approximately equal twin compon...

  14. Zeeman spectrum of scandium

    International Nuclear Information System (INIS)

    Lulu, B.A.

    1980-09-01

    The spectra of Sc I, Sc II, Sc III, and Sc IV are analyzed through the use of the Zeeman effect. A sliding spark of the author's design is used in conjunction with a 27 kilogauss electromagnet. The spectra have (reciprocal) dispersions of 0.2 to 0.5 A/mm. 10 Sc I levels, 16 Sc II levels and 5 Sc III levels show Zeeman splitting. No Sc IV Zeeman patterns were observed. 2 Sc I, 4 Sc II, and all of the Sc III level data are new

  15. Impact of layer and substrate properties on the surface acoustic wave velocity in scandium doped aluminum nitride based SAW devices on sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Gillinger, M., E-mail: manuel.gillinger@tuwien.ac.at; Knobloch, T.; Schneider, M.; Schmid, U. [Institute of Sensor and Actuator Systems, TU Wien, 1040 Vienna (Austria); Shaposhnikov, K.; Kaltenbacher, M. [Institute of Mechanics and Mechatronics, TU Wien, 1040 Vienna (Austria)

    2016-06-06

    This paper investigates the performance of surface acoustic wave (SAW) devices consisting of reactively sputter deposited scandium doped aluminum nitride (Sc{sub x}Al{sub 1-x}N) thin films as piezoelectric layers on sapphire substrates for wireless sensor or for RF-MEMS applications. To investigate the influence of piezoelectric film thickness on the device properties, samples with thickness ranging from 500 nm up to 3000 nm are fabricated. S{sub 21} measurements and simulations demonstrate that the phase velocity is predominantly influenced by the mass density of the electrode material rather than by the thickness of the piezoelectric film. Additionally, the wave propagation direction is varied by rotating the interdigital transducer structures with respect to the crystal orientation of the substrate. The phase velocity is about 2.5% higher for a-direction compared to m-direction of the sapphire substrate, which is in excellent agreement with the difference in the anisotropic Young's modulus of the substrate corresponding to these directions.

  16. The effect of scandium addition on microstructure and mechanical properties of Al–Si–Mg alloy: A multi-refinement modifier

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Cong, E-mail: xucong55555@gmail.com [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Xiao, Wenlong, E-mail: wlxiao@buaa.edu.cn [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Hanada, Shuji [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yamagata, Hiroshi [Center for Advanced Die Engineering and Technology, Gifu University, 1-1 Yanagido, Gifu City, Gifu 501-1193 (Japan); Ma, Chaoli [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China)

    2015-12-15

    Effect of scandium (Sc) additions on the microstructure, mechanical properties and fracture behavior of Al–Si–Mg casting alloy (F357) were systematically investigated. It was found that Sc addition caused a multi-refining efficiency on the microstructure of as-cast F357 alloy, including refinement of grains and secondary dendrite arm spacing (SDAS), modification of eutectic Si and harmless disposal of β-Al{sub 5}FeSi phase. Subsequent T6 heat treatment had further induced the complete spheroidization of eutectic Si and precipitation of fine secondary Al{sub 3}Sc dispersoids in the Sc modified alloys. Thus the mechanical properties, especially the ductility, were significantly enhanced by the addition of Sc combined with the heat treatment. The highest ultimate tensile strength, yield strength and elongation were achieved in 0.8 wt.% Sc modified F357 alloy combined with T6 heat treatment. Furthermore, fractographic examinations indicated that the ductile fracture mechanism served as a dominate role in the modified alloys due to the formation of fine, deep and uniformly distributed dimples. - Highlights: • Detailed characterization of the multi-refining microstructure of Sc modified F357 alloy was performed. • The multi-refinement was proposed to refine grain and SDAS, modify eutectic Si and β-phase. • Sc modifier combined with T6 treatment is effective in improving tensile properties. • Modification of eutectic Si in F357 alloy with Sc is consistent with the IIT mechanism.

  17. Serum sample levels of bromine, iron, scandium and zinc in preschool children of Atayal and Bunun aborigines living in central Taiwan

    International Nuclear Information System (INIS)

    Chien-Yi Chen; Ding-Bang Lin; Yuan-Yaw Wei

    2006-01-01

    This study determined bromine, iron, scandium and zinc serum levels in Taiwanese aboriginal preschool children living in remote mountainous areas to increase the understanding of the social, cultural, nutrient and ethnic background of the Taiwanese children. Seventy-three serum samples were taken from two ethnic groups of preschool children, Atayal aborigines (AAPC) and Bunun aborigines (BAPC). Sera of these children were freeze dried. Trace elements in sera were identified by instrumental neutron activation analysis (INAA). The accuracy and precision of INAA was evaluated using certified reference materials: Tomato Leaves (NIST-SRM 1570a) and Lichen (IAEA-336). Statistical analysis identified several different patterns for ethnic groups, gender and age via the two-tailed Student's t-test. Analytical results showed that the ranges of Br, Fe, Sc and Zn in sera were somewhat wide. The Zn serum levels (p < 0.05) and Br serum levels (p < 0.01) in the AAPC were significantly lower than those in the BAPC. However, there were no significant differences in Fe or Sc serum levels between the two groups. Analytical results were compared to published data for different counties. This study is the first investigating trace elements in Taiwanese aborigines and can be used to establish a much-needed serum element database. (author)

  18. Comparative microstructure and electrical property studies of lead scandium tantalate thin films as prepared by LDCVD, sol-gel and sputtering techniques

    International Nuclear Information System (INIS)

    Huang, Z; Donohue, P P; Zhang, Q; Williams, D J; Anthony, C J; Whatmore, R W; Todd, M A

    2003-01-01

    Lead scandium tantalate (PST) thin films for uncooled infrared (IR) detector applications have been deposited by liquid delivery chemical vapour deposition (LDCVD), sputtering and sol-gel techniques. The sol-gel and sputtered films were deposited at low temperature into a non-ferroelectric phase with the required perovskite structure being formed using a high temperature rapid thermal anneal (RTA). In contrast to this, the LDCVD films were deposited at high temperature directly into the perovskite phase but were found to still require a high temperature RTA step to optimize their merit for IR detection. Detailed structural and electrical characterization of the PST films deposited by these different methods have revealed that there is no simple relationship between microstructure and electrical properties. The sol-gel and LDCVD techniques produce thin films with excellent microstructures, as determined by x-ray diffraction analysis and transmission electron microscopy, but inferior electrical properties and relatively low merit figures. By contrast, the sputtered and then rapid thermal annealed films have inferior microstructures, characterized by extensive voiding, but excellent electrical properties and high merit figures

  19. Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications.

    Science.gov (United States)

    Verma, Mahesh; Kumari, Pooja; Gupta, Rekha; Gill, Shubhra; Gupta, Ankur

    2015-01-01

    Erbium, chromium: Yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser has been successfully used in the ablation of dental hard and soft tissues. It has been reported that this system is also useful for preparing tooth surfaces and etching, but no consensus exist in the literature regarding the advantage of lasers over conventional tooth preparation technique. Labial surfaces of 25 extracted human maxillary central incisors were divided into two halves. Right half was prepared with diamond bur and left half with Er, Cr; YSGG laser and a reduction of 0.3-0.5 mm was carried out. Topography of prepared surfaces of five teeth were examined under scanning electron microscope (SEM). The remaining samples were divided into 4 groups of 10 specimens each based on the surface treatment received: One group was acid etched and other was nonetched. Composite resin cylinders were bonded on prepared surfaces and shear bond strength was assessed using a universal testing machine. The SEM observation revealed that the laser prepared surfaces were clean, highly irregular and devoid of a smear layer. Bur prepared surfaces were relatively smooth but covered with smear layer. Highest bond strength was shown by laser prepared acid etched group, followed by bur prepared the acid etched group. The bur prepared nonacid etched group showed least bond strength. Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

  20. Aluminum-Scandium Alloys: Material Characterization, Friction Stir Welding, and Compatibility With Hydrogen Peroxide (MSFC Center Director's Discretionary Fund Final Report, Proj. No. 04-14)

    Science.gov (United States)

    Lee, J. A.; Chen, P. S.

    2004-01-01

    This Technical Memorandum describes the development of several high-strength aluminum (Al) alloys that are compatible with hydrogen peroxide (H2O2) propellant for NASA Hypersonic-X (Hyper-X) vehicles fuel tanks and structures. The yield strengths for some of these Al-magnesium-based alloys are more than 3 times stronger than the conventional 5254-H112 Al alloy, while maintaining excellent H2O2 compatibility similar to class 1 5254 alloy. The alloy development strategy is to add scandium, zirconium, and other transitional metals with unique electrochemical properties, which will not act as catalysts, to decompose the highly concentrated 90 percent H2O2. Test coupons are machined from sheet metals for H2O2 long-term exposure testing and mechanical properties testing. In addition, the ability to weld the new alloys using friction stir welding has also been explored. The new high-strength alloys could represent an enabling material technology for Hyper-X vehicles, where flight weight reduction is a critical requirement.

  1. Investigation of concentration-dependence of thermodynamic properties of lanthanum, yttrium, scandium and terbium in eutectic LiCl-KCl molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yafei; Zhou, Wentao; Zhang, Jinsuo, E-mail: zhang.3558@osu.edu

    2016-09-15

    Thermodynamic properties of rare earth metals in LiCl-KCl molten salt electrolyte are crucial to the development of electrochemical separation for the treatment of used nuclear fuels. In the present study, activity coefficient, apparent potential, and diffusion coefficient of lanthanum, yttrium, scandium, and terbium in the molten salt (58 at% LiCl and 42 at% KCl) were calculated by the method of molecular dynamics simulation up to a concentration around 3 at% at temperatures of 723 K and 773 K. It was found that the activity coefficient and the apparent potential increase with the species concentration while diffusion coefficient shows a trend of increase followed by decrease. The calculated results were validated by available measurement data of dilution cases. This research extends the range of data to a wide component and would provide further insight to the pyroprocessing design and safeguards. - Highlights: • Investigation of activity coefficient, apparent potential and diffusion coefficient at different concentrations. • MD simulation was studied for the calculation of thermodynamic properties of rare earth elements in molten salt. • The present study is a pioneering work focusing on the concentration dependence of thermodynamic properties.

  2. Use of tetracycline as complexing agent in analytical chemistry

    International Nuclear Information System (INIS)

    Nastasi, M.J.C.; Saiki, M.; Lima, F.W.

    1977-01-01

    The behavior of tetracyline as complexing agent in solvent extraction studies is presented. The extraction curves for the lanthanide elements, scandium, thorium, uranium and neptunium, are determined for the extraction system benzyl alcohol-tetracycline, as well as the acid and extractant dependences of extraction of the lanthanide elements. Separation of neptunium from uranium is formed by carrying out the extraction experiment at a proper pH value. Use is made of masking agents namely, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), in order to obtain separations of uranium from scadium and lanthanides as well as of uranium and thorium, respectively. The extraction experiments are carried out by using radioisotopes of each element, except for uranium in which case the determinations are by using epithermal neutron activation analysis [pt

  3. On new ternary equiatomic scandium transition metal aluminum compounds ScTAl with T = Cr, Ru, Ag, Re, Pt, and Au

    Energy Technology Data Exchange (ETDEWEB)

    Radzieowski, Mathis; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Benndorf, Christopher [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Haverkamp, Sandra [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; University of Sao Paulo, Sao Carlos, SP (Brazil). Inst. of Physics

    2016-08-01

    The new equiatomic scandium transition metal aluminides ScTAl for T = Cr, Ru, Ag, Re, Pt, and Au were obtained by arc-melting of the elements followed by subsequent annealing for crystal growth. The samples were studied by powder and single crystal X-ray diffraction. The structures of three compounds were refined from single crystal X-ray diffractometer data: ScCrAl, MgZn{sub 2} type, P6{sub 3}/mmc, a = 525.77(3), c = 858.68(5) pm, R{sub 1} = 0.0188, wR{sub 2} = 0.0485, 204 F{sup 2} values, 13 variables, ScPtAl, TiNiSi type, Pnma, a = 642.83(4), b = 428.96(2), c = 754.54(5) pm, R{sub 1} = 0.0326, wR{sub 2} = 0.0458, 448 F{sup 2} values, 20 variables and ScAuAl, HfRhSn type, P anti 62c, a = 722.88(4), c = 724.15(4) pm, R{sub 1} = 0.0316, wR{sub 2} = 0.0653, 512 F{sup 2} values, 18 variables. Phase pure samples of all compounds were furthermore investigated by magnetic susceptibility measurements, and Pauli-paramagnetism but no superconductivity was observed down to 2.1 K for all of them. The local structural features and disordering phenomena have been characterized by {sup 27}Al and {sup 45}Sc magic angle spinning (MAS) and static NMR spectroscopic investigations.

  4. Comparative study of the shear bond strength of composite resin bonded to enamel treated with acid etchant and erbium, chromium: Yttrium, scandium, gallium, garnet laser

    Directory of Open Access Journals (Sweden)

    Adel Sulaiman Alagl

    2016-01-01

    Full Text Available Aim: The purpose of this investigation is in vitro comparison of the shear bond strength (SBS of composite resin bonded to enamel pretreated with an acid etchant against enamel etched with erbium, chromium: yttrium, scandium, gallium, garnet (Er, Cr:YSGG laser. Materials and Methods: Sixty premolars were sectioned mesiodistally and these 120 specimens were separated into two groups of 60 each (Groups A and B. In Group A (buccal surfaces, enamel surface was etched using 37% phosphoric acid for 15 s. In Group B (lingual surfaces, enamel was laser-etched at 2W for 10 s by Er, Cr:YSGG laser operational at 2780 nm with pulse duration of 140 μs and a frequency of 20 Hz. After application of bonding agent on all test samples, a transparent plastic cylinder of 1.5 mm × 3 mm was loaded with composite and bonded by light curing for 20 s. All the samples were subjected to SBS analysis using Instron Universal testing machine. Failure modes were observed under light microscope and grouped as adhesive, cohesive, and mixed. Failure mode distributions were compared using the Chi-square test. Results: SBS values obtained for acid-etched enamel were in the range of 7.12–28.36 megapascals (MPa and for laser-etched enamel were in the range of 6.23–23.35 MPa. Mean SBS for acid-etched enamel was 15.77 ± 4.38 MPa, which was considerably greater (P < 0.01 than laser-etched enamel 11.24 ± 3.76 MPa. The Chi-square test revealed that the groups showed no statistically significant differences in bond failure modes. Conclusions: We concluded that the mean SBS of composite with acid etching is significantly higher as compared to Er, Cr: YSGG (operated at 2W for 10 s laser-etched enamel.

  5. Interaction of phosphorus pentachloride with trichlorides of metals of the second half of lanthanide series and scandium subgroup

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Vovkotrub, Eh.G.; Strekalovskij, V.N.

    1999-01-01

    With the use of Raman laser spectroscopy a study is made into interactions of molten TbCl 3 , ErCl 3 , YbCl 3 , YCl 3 and ScCl 3 with phosphorus pentachloride vapors at elevated pressure (up to 30-35 atm) as well as solid REM trichlorides with molten PCl 5 . It is revealed for first time that the interaction can be accompanied by reactions resulting in formation of complex chloride cations [PCl 4 ] + and anions [MCl 6 ] 3- of trivalent metals. The prediction is made about the possibility of chemical interaction of phosphorus pentachloride with trichlorides of all yttrium subgroup lanthanides under similar conditions

  6. Adsorption behaviour of scandium, yttrium, cerium and uranium from xylenol orange solutions onto anion-exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Chao, H E; Suzuki, N [Tohoku Univ., Sendai (Japan). Faculty of Science

    1981-04-01

    The effects of concentration, pH and anions on the adsorption behaviour of xylenol orange (XO) on the strong anion exchangers, Amberlite IRA-400 and Hitachi 2632 are described. The adsorption behaviour of the XO complexes of Ce(III), Y(III), Sc(III) and U(VI) on the Amberlite IRA-400 resin as a function of XO concentration and pH is reported. A continuous-flow radiometric detector is used to investigate the separations of the Ce(III)-Sc(III), Y(III)-Sc(III), and Ce(III)-Y(III) pairs on the XO-form Hitachi 2632 resin column by pH control. Satisfactory separations of the Ce(III)-Sc(III) and Y(III)-Sc(III) pairs are achieved.

  7. A novel boron-rich quaternary scandium borocarbosilicide Sc3.67-xB41.4-y-zC0.67+zSi0.33-w

    International Nuclear Information System (INIS)

    Tanaka, Takaho; Yamamoto, Akiji; Sato, Akira

    2004-01-01

    A novel quaternary scandium borocarbosilicide Sc 3.67-x B 41.4-y-z C 0.67+z Si 0.33-w was found. Single crystallites were obtained as an intergrowth phase in the float-zoned single crystal of Sc 0.83-x B 10.0-y C 0.17+y Si 0.083-z that has a face-centered cubic crystal structure. Single crystal structure analysis revealed that the compound has a hexagonal structure with lattice constants a = b = 1.43055(8) nm and c = 2.37477(13) nm and space group P6-barm2 (No. 187). The crystal composition calculated from the structure analysis for the crystal with x = 0.52, y = 1.42, z = 1.17, and w = 0.02 was ScB 12.3 C 0.58 Si 0.10 and that agreed rather well with the composition of ScB 11.5 C 0.61 Si 0.04 measured by EPMA. In the crystal structure that is a new structure type of boron-rich borides, there are 79 structurally independent atomic sites, 69 boron and/or carbon sites, two silicon sites and eight scandium sites. Boron and carbon form seven structurally independent B 12 icosahedra, one B 9 polyhedron, one B 10 polyhedron, one irregularly shaped B 16 polyhedron in which only 10.7 boron atoms are available because of partial occupancies and 10 bridging sites. All polyhedron units and bridging site atoms interconnect each other forming a three-dimensional boron framework structure. Sc atoms reside in the open spaces in the boron framework structure

  8. Use of tetracycline as complexing agent in radiochemical separations

    International Nuclear Information System (INIS)

    Saiki, M.; Nastasi, M.J.C.; Lima, F.W.

    1981-01-01

    The use of the antibiotic agent tetracycline (TC) for analytical purposes in solvent extraction procedures is presented. Individual extraction curves for the lanthanides, zinc, scandium, uranium, thorium, neptunium and protactinium were obtained. Separation of those elements from one another, and of uranium from selenium, bromine, antimony, barium, tantalum and tungsten was carried out. In all cases benzyl alcohol was the diluent used to dissolve tetracycline hydrochloride. Sodium chloride was used as supporting electrolyte for the lanthanide separations and sodium perchlorate for the other elements mentioned. Stability or formation constants for the lanthanide complexes as well as for thorium complex with tetracycline were determined by using the methods of average number of ligands, the limiting value (for thorium), the two parameters and the weighted least squares. For the lanthanides, the stability constants of the complexes Ln(TC) 3 go from 9.35+-0.22 for lanthanum up to 10.84+-0.11 for lutetium. For the Th(TC) 4 complex the formation constant is equal to 24.6+-0.3. Radioisotopes of the respective elements were used as tracers for the determinations. (author)

  9. Thermal effects from modified endodontic laser tips used in the apical third of root canals with erbium-doped yttrium aluminium garnet and erbium, chromium-doped yttrium scandium gallium garnet lasers.

    Science.gov (United States)

    George, Roy; Walsh, Laurence J

    2010-04-01

    To evaluate the temperature changes occurring on the apical third of root surfaces when erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser energy was delivered with a tube etched, laterally emitting conical tip and a conventional bare design optical fiber tip. Thermal effects of root canal laser treatments on periodontal ligament cells and alveolar bone are of concern in terms of safety. A total of 64 single-rooted extracted teeth were prepared 1 mm short of the working length using rotary nickel-titanium Pro-Taper files to an apical size corresponding to a F5 Pro-Taper instrument. A thermocouple located 2 mm from the apex was used to record temperature changes arising from delivery of laser energy through laterally emitting conical tips or plain tips, using an Er:YAG or Er,Cr:YSGG laser. For the Er:YAG and Er,Cr:YSGG systems, conical fibers showed greater lateral emissions (452 + 69% and 443 + 64%) and corresponding lower forward emissions (48 + 5% and 49 + 5%) than conventional plain-fiber tips. All four combinations of laser system and fiber design elicited temperature increases less than 2.5 degrees C during lasing. The use of water irrigation attenuated completely the thermal effects of individual lasing cycles. Laterally emitting conical fiber tips can be used safely under defined conditions for intracanal irradiation without harmful thermal effects on the periodontal apparatus.

  10. A Mononuclear Non-Heme Manganese(IV)-Oxo Complex Binding Redox-Inactive Metal Ions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junying; Lee, Yong-Min; Davis, Katherine M.; Wu, Xiujuan; Seo, Mi Sook; Cho, Kyung-Bin; Yoon, Heejung; Park, Young Jun; Fukuzumi, Shunichi; Pushkar, Yulia N.; Nam, Wonwoo [Ewha; (Purdue); (Osaka)

    2013-05-29

    Redox-inactive metal ions play pivotal roles in regulating the reactivities of high-valent metal–oxo species in a variety of enzymatic and chemical reactions. A mononuclear non-heme Mn(IV)–oxo complex bearing a pentadentate N5 ligand has been synthesized and used in the synthesis of a Mn(IV)–oxo complex binding scandium ions. The Mn(IV)–oxo complexes were characterized with various spectroscopic methods. The reactivities of the Mn(IV)–oxo complex are markedly influenced by binding of Sc3+ ions in oxidation reactions, such as a ~2200-fold increase in the rate of oxidation of thioanisole (i.e., oxygen atom transfer) but a ~180-fold decrease in the rate of C–H bond activation of 1,4-cyclohexadiene (i.e., hydrogen atom transfer). The present results provide the first example of a non-heme Mn(IV)–oxo complex binding redox-inactive metal ions that shows a contrasting effect of the redox-inactive metal ions on the reactivities of metal–oxo species in the oxygen atom transfer and hydrogen atom transfer reactions.

  11. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  12. Complex chemistry

    International Nuclear Information System (INIS)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-01

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  13. (II) complexes

    African Journals Online (AJOL)

    activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

  14. Communication complexity and information complexity

    Science.gov (United States)

    Pankratov, Denis

    Information complexity enables the use of information-theoretic tools in communication complexity theory. Prior to the results presented in this thesis, information complexity was mainly used for proving lower bounds and direct-sum theorems in the setting of communication complexity. We present three results that demonstrate new connections between information complexity and communication complexity. In the first contribution we thoroughly study the information complexity of the smallest nontrivial two-party function: the AND function. While computing the communication complexity of AND is trivial, computing its exact information complexity presents a major technical challenge. In overcoming this challenge, we reveal that information complexity gives rise to rich geometrical structures. Our analysis of information complexity relies on new analytic techniques and new characterizations of communication protocols. We also uncover a connection of information complexity to the theory of elliptic partial differential equations. Once we compute the exact information complexity of AND, we can compute exact communication complexity of several related functions on n-bit inputs with some additional technical work. Previous combinatorial and algebraic techniques could only prove bounds of the form theta( n). Interestingly, this level of precision is typical in the area of information theory, so our result demonstrates that this meta-property of precise bounds carries over to information complexity and in certain cases even to communication complexity. Our result does not only strengthen the lower bound on communication complexity of disjointness by making it more exact, but it also shows that information complexity provides the exact upper bound on communication complexity. In fact, this result is more general and applies to a whole class of communication problems. In the second contribution, we use self-reduction methods to prove strong lower bounds on the information

  15. Complexity Plots

    KAUST Repository

    Thiyagalingam, Jeyarajan

    2013-06-01

    In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  16. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    KAUST Repository

    D'Elia, Valerio

    2015-05-25

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    KAUST Repository

    D'Elia, Valerio; Pelletier, Jeremie; Basset, Jean-Marie

    2015-01-01

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Superconductivity in Ternary Rare-Earth Transition Metal Silicides and Germanides with the SCANDIUM(5) COBALT(4) SILICON(10)-TYPE Structure.

    Science.gov (United States)

    Berg, Linda Sue

    A systematic study of the superconducting and normal state properties of some ternary rare earth transition metal silicides and germanides of the Sc(,5)Co(,4)Si(,10) -type is reported in this work. Low temperature heat capacity measurements indicate the presence of a complicated phonon density of states in these structurally complex compounds. A better description of the phonon spectrum of the high T(,c) materials, Sc(,5)Rh(,4)Si(,10), Sc(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10), given by a model proposed by Junod et al.('1), is presented and discussed. The large values of (DELTA)C/(gamma)(,n)T(,c) and the electron-phonon coupling constant for these high T(,c) compounds indicate that they are strong-coupled superconductors. Relative to other ternary superconductors, many of these materials have large Debye temperatures. The BSC theory does not seem to afford an adequate description of the supercon- ducting state in these compounds. DC electrical resistivity measurements on these compounds show resistivity behaviors deviating from those exhibited by simple metals. The (rho)(T) data for Y(,5)Ir(,4)Si(,10), Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10), indicate the presence of anomalies. Static molar magnetic susceptibility measurements performed on these compounds indicate (1) a small effective magnetic moment of 0.26(mu)(,B) on the Co atom and (2) anomalous behaviors in the Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), Y(,5)Ir(,4)Si(,10), Lu(,5)Ir(,4)Ge(,10), and Y(,5)Rh(,4)Ge(,10) data. It is suggested that the same mechanism, namely, the forma- tion of a charge- or spin-density wave, is causing the anomalous behaviors in both the resistivity and susceptibility data. Lastly, upper critical magnetic field measurements were performed on Sc(,5)Co(,4)Si(,10), Sc(,5)Rh(,4)Si(,10), Sc(,5)Ir(,4)Si(,10), Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10). Relative to the other five samples, Y(,5)Os(,4)Ge(,10) exhibits very high values for (-d

  19. Complexity Theory

    Science.gov (United States)

    Lee, William H K.

    2016-01-01

    A complex system consists of many interacting parts, generates new collective behavior through self organization, and adaptively evolves through time. Many theories have been developed to study complex systems, including chaos, fractals, cellular automata, self organization, stochastic processes, turbulence, and genetic algorithms.

  20. Managing Complexity

    DEFF Research Database (Denmark)

    Maylath, Bruce; Vandepitte, Sonia; Minacori, Patricia

    2013-01-01

    and into French. The complexity of the undertaking proved to be a central element in the students' learning, as the collaboration closely resembles the complexity of international documentation workplaces of language service providers. © Association of Teachers of Technical Writing.......This article discusses the largest and most complex international learning-by-doing project to date- a project involving translation from Danish and Dutch into English and editing into American English alongside a project involving writing, usability testing, and translation from English into Dutch...

  1. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  2. Softball Complex

    Science.gov (United States)

    Ellis, Jim

    1977-01-01

    The Parks and Recreation Department of Montgomery, Alabama, has developed a five-field softball complex as part of a growing community park with facilities for camping, golf, aquatics, tennis, and picnicking. (MJB)

  3. Lecithin Complex

    African Journals Online (AJOL)

    1Department of Food Science and Engineering, Xinyang College of Agriculture and ... Results: The UV and IR spectra of the complex showed an additive effect of polydatin-lecithin, in which .... Monochromatic Cu Ka radiation (wavelength =.

  4. Atomic Transition Probabilities Scandium through Manganese

    International Nuclear Information System (INIS)

    Martin, G.A.; Fuhr, J.R.; Wiese, W.L.

    1988-01-01

    Atomic transition probabilities for about 8,800 spectral lines of five iron-group elements, Sc(Z = 21) to Mn(Z = 25), are critically compiled, based on all available literature sources. The data are presented in separate tables for each element and stage of ionization and are further subdivided into allowed (i.e., electric dipole-E1) and forbidden (magnetic dipole-M1, electric quadrupole-E2, and magnetic quadrupole-M2) transitions. Within each data table the spectral lines are grouped into multiplets, which are in turn arranged according to parent configurations, transition arrays, and ascending quantum numbers. For each line the transition probability for spontaneous emission and the line strength are given, along with the spectroscopic designation, the wavelength, the statistical weights, and the energy levels of the upper and lower states. For allowed lines the absorption oscillator strength is listed, while for forbidden transitions the type of transition is identified (M1, E2, etc.). In addition, the estimated accuracy and the source are indicated. In short introductions, which precede the tables for each ion, the main justifications for the choice of the adopted data and for the accuracy rating are discussed. A general introduction contains a discussion of our method of evaluation and the principal criteria for our judgements

  5. Fast neutron scattering near shell closures: Scandium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1992-08-01

    Neutron differential elastic- and inelastic-scattering cross sections are measured from ∼ 1.5 to 10 MeV with sufficient detail to define the energy-averaged behavior of the scattering processes. Neutrons corresponding to excitations of 465 ± 23, 737 ± 20, 1017 ± 34, 1251 ± 20, 1432 ± 23 and 1692 ± 25 keV are observed. It is shown that the observables, including the absorption cross section, are reasonably described with a conventional optical-statistical model having energy-dependent geometric parameters. These energy dependencies are alleviated when the model is extended to include the contributions of the dispersion relationship. The model parameters are conventional, with no indication of anomalous behavior of the neutron interaction with 45 Sc, five nucleons from the doubly closed shell at 40 Ca

  6. Neutron activation determination of rhenium in mineral raw materials of complex composition

    International Nuclear Information System (INIS)

    Shiryaeva, M.B.; Lyubimova, L.N.; Salmin, Yu.P.; Ryumina, K.N.; Tatarkin, M.A.

    1984-01-01

    The method of neutron-activation rhenium determination in mineral raw material of complex composition is developed, according to which easily hydrolized elements: scandium, iron, lanthanum, ytterbium, protactinium, hafnium and partially ruthenium and osmium are isolated in the form of hydroxides after smelting of a sample, which has been previously irradiated in nuclear reactor (thermal neutron flux 1.2x10 13 n/cm 2 xs for 22 hr) with sodium peroxide and leaching of the melt by water. To separate Re from other interfering elements extraction of perrhenate-ion by methylethylketone from alkali solution is used. Interfering effect of gold is eliminated by its extraction with TBP 30% solution in toluence or benzene from 1 M HNO 3 . Activity of rhenium preparations, singled out from samples of comparison, is measured, using multichannel γ-spectrometer with Ge(Li)-coaxial detector of high resolution (approximately 2.0-2.2 keV over the line 122 keV 5+ Co). Relative standard deviation in Re content range 5x10 -7 -5x10 -2 % does not exceed 0.3

  7. Complex analysis

    CERN Document Server

    Freitag, Eberhard

    2005-01-01

    The guiding principle of this presentation of ``Classical Complex Analysis'' is to proceed as quickly as possible to the central results while using a small number of notions and concepts from other fields. Thus the prerequisites for understanding this book are minimal; only elementary facts of calculus and algebra are required. The first four chapters cover the essential core of complex analysis: - differentiation in C (including elementary facts about conformal mappings) - integration in C (including complex line integrals, Cauchy's Integral Theorem, and the Integral Formulas) - sequences and series of analytic functions, (isolated) singularities, Laurent series, calculus of residues - construction of analytic functions: the gamma function, Weierstrass' Factorization Theorem, Mittag-Leffler Partial Fraction Decomposition, and -as a particular highlight- the Riemann Mapping Theorem, which characterizes the simply connected domains in C. Further topics included are: - the theory of elliptic functions based on...

  8. Subgroup complexes

    CERN Document Server

    Smith, Stephen D

    2011-01-01

    This book is intended as an overview of a research area that combines geometries for groups (such as Tits buildings and generalizations), topological aspects of simplicial complexes from p-subgroups of a group (in the spirit of Brown, Quillen, and Webb), and combinatorics of partially ordered sets. The material is intended to serve as an advanced graduate-level text and partly as a general reference on the research area. The treatment offers optional tracks for the reader interested in buildings, geometries for sporadic simple groups, and G-equivariant equivalences and homology for subgroup complexes.

  9. Complex manifolds

    CERN Document Server

    Morrow, James

    2006-01-01

    This book, a revision and organization of lectures given by Kodaira at Stanford University in 1965-66, is an excellent, well-written introduction to the study of abstract complex (analytic) manifolds-a subject that began in the late 1940's and early 1950's. It is largely self-contained, except for some standard results about elliptic partial differential equations, for which complete references are given. -D. C. Spencer, MathSciNet The book under review is the faithful reprint of the original edition of one of the most influential textbooks in modern complex analysis and geometry. The classic

  10. Complex Networks

    CERN Document Server

    Evsukoff, Alexandre; González, Marta

    2013-01-01

    In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of  deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...

  11. Managing Complexity

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Posse, Christian; Malard, Joel M.

    2004-08-01

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.

  12. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  13. Complex dynamics

    CERN Document Server

    Carleson, Lennart

    1993-01-01

    Complex dynamics is today very much a focus of interest. Though several fine expository articles were available, by P. Blanchard and by M. Yu. Lyubich in particular, until recently there was no single source where students could find the material with proofs. For anyone in our position, gathering and organizing the material required a great deal of work going through preprints and papers and in some cases even finding a proof. We hope that the results of our efforts will be of help to others who plan to learn about complex dynamics and perhaps even lecture. Meanwhile books in the field a. re beginning to appear. The Stony Brook course notes of J. Milnor were particularly welcome and useful. Still we hope that our special emphasis on the analytic side will satisfy a need. This book is a revised and expanded version of notes based on lectures of the first author at UCLA over several \\Vinter Quarters, particularly 1986 and 1990. We owe Chris Bishop a great deal of gratitude for supervising the production of cour...

  14. Cosmic Complexity

    Science.gov (United States)

    Mather, John C.

    2012-01-01

    What explains the extraordinary complexity of the observed universe, on all scales from quarks to the accelerating universe? My favorite explanation (which I certainty did not invent) ls that the fundamental laws of physics produce natural instability, energy flows, and chaos. Some call the result the Life Force, some note that the Earth is a living system itself (Gaia, a "tough bitch" according to Margulis), and some conclude that the observed complexity requires a supernatural explanation (of which we have many). But my dad was a statistician (of dairy cows) and he told me about cells and genes and evolution and chance when I was very small. So a scientist must look for me explanation of how nature's laws and statistics brought us into conscious existence. And how is that seemll"!gly Improbable events are actually happening a!1 the time? Well, the physicists have countless examples of natural instability, in which energy is released to power change from simplicity to complexity. One of the most common to see is that cooling water vapor below the freezing point produces snowflakes, no two alike, and all complex and beautiful. We see it often so we are not amazed. But physlc!sts have observed so many kinds of these changes from one structure to another (we call them phase transitions) that the Nobel Prize in 1992 could be awarded for understanding the mathematics of their common features. Now for a few examples of how the laws of nature produce the instabilities that lead to our own existence. First, the Big Bang (what an insufficient name!) apparently came from an instability, in which the "false vacuum" eventually decayed into the ordinary vacuum we have today, plus the most fundamental particles we know, the quarks and leptons. So the universe as a whole started with an instability. Then, a great expansion and cooling happened, and the loose quarks, finding themselves unstable too, bound themselves together into today's less elementary particles like protons and

  15. The features of the atomic structure of the impurities complexes in the irradiated materials doped by the elements with a large atomic radii

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Sleptsov, A.N.; Marchenko, I.G.; Sleptsov, S.N.

    1995-01-01

    The interaction between impurity atoms and radiation-induced defects in Ni(Sc), Ni(Ti), Ni(Pr) and Ni(Y) alloys irradiated with 5 and 30 MeV electrons were studied by the residual resistivity measurements, and the methods of reciprocal damage rate and positron annihilation. The activation energies of the main recovery stages in pure nickel (I D+E - 54 K, II 4 -250 K, III 2 - 390 K) and dilute alloys (up to 700 K) were determined. The radii trapping, r t , of self-interstitial atoms (SIA) by the Sc and Ti atoms were calculated in the temperature range 45-300 K.It is found that the scandium atoms (among all large atomic size elements) are effective traps for SIA and vacancies and form compound complexes. The binding energy of vacancy-impurity complexes are about 0.25, 0.30 and 0.6 - 0.8 eV in Ni(Ti), Ni(Y) and Ni(Sc) alloys, respectively. The solubilities of Sc, Ti, Y and Pr in nickel were deduced from the analysis of dependence of the specific residual resistivity (ρ t ) and the lattice parameter (Δa/a) on concentration. 38 refs., 3 tab., 10 figs

  16. Chemical and biological evaluation of 153Sm and 46/47Sc complexes of indazolebisphosphonates for targeted radiotherapy

    International Nuclear Information System (INIS)

    Neves, Maria; Teixeira, Fatima C.; Antunes, Ines; Majkowska, Agnieszka; Gano, Lurdes; Santos, Ana Cristina

    2011-01-01

    Introduction: Novel 1-hydroxy-1,1-bisphosphonates derived from indazole and substituted at the C-3 position were labeled with the radionuclides 46 Sc and 153 Sm. Several parameters such as molar ligand concentration, pH, reaction time and temperature were studied. The radiolabelling yield, reaction kinetics and stability were assessed and radiocomplexes were evaluated by in vitro and in vivo experiments. Methods: The radionuclides 46 Sc and 153 Sm were obtained by neutron irradiation of natural Sc 2 O 3 and enriched 152 Sm 2 O 3 (98.4%) targets at the neutron flux of 3x10 14 n cm -2 s -1 . The radiolabelling yield, reaction kinetics and stability were accomplished by ascending instant thin layer chromatography. The radiocomplexes were submitted to in vitro experiments (hydroxyapatite binding and lipophilicity) and biodistribution studies in animal models. Results: The radionuclides 46 Sc and 153 Sm were produced with specific activities of 100 and 430 MBq mg -1 , respectively. High radiochemical yields were achieved and the hydrophilic radiocomplexes have shown high degree of binding to hydroxyapatite. Biodistribution studies at 1, 3 and 24 h of the 4 radiocomplexes under study, have showed a similar biodistribution profile with a relatively high bone uptake, slow clearance from blood and a very slow rate of total radioactivity excretion from the whole animal body. Conclusion: We have developed a new class of indazolebisphosphonates complexes with radioisotopes of samarium and scandium. All complexes have shown high degree of binding to hydroxyapatite, which could be attributed to the ionized phosphonate groups. The bone uptake and the bone-to-muscle ratios were relatively low.

  17. Chemical and biological evaluation of {sup 153}Sm and {sup 46/47}Sc complexes of indazolebisphosphonates for targeted radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Maria, E-mail: mneves@itn.p [Instituto Tecnologico e Nuclear, Sacavem (Portugal); Teixeira, Fatima C.; Antunes, Ines [INETI-Departamento de Tecnologia de Industrias Quimicas, Lisboa (Portugal); Majkowska, Agnieszka [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Gano, Lurdes [Instituto Tecnologico e Nuclear, Sacavem (Portugal); Santos, Ana Cristina [IBB-Instituto de Biofisica e Biomatematica, Coimbra (Portugal)

    2011-01-15

    Introduction: Novel 1-hydroxy-1,1-bisphosphonates derived from indazole and substituted at the C-3 position were labeled with the radionuclides {sup 46}Sc and {sup 153}Sm. Several parameters such as molar ligand concentration, pH, reaction time and temperature were studied. The radiolabelling yield, reaction kinetics and stability were assessed and radiocomplexes were evaluated by in vitro and in vivo experiments. Methods: The radionuclides {sup 46}Sc and {sup 153}Sm were obtained by neutron irradiation of natural Sc{sub 2}O{sub 3} and enriched {sup 152}Sm{sub 2}O{sub 3} (98.4%) targets at the neutron flux of 3x10{sup 14} n cm{sup -2} s{sup -1}. The radiolabelling yield, reaction kinetics and stability were accomplished by ascending instant thin layer chromatography. The radiocomplexes were submitted to in vitro experiments (hydroxyapatite binding and lipophilicity) and biodistribution studies in animal models. Results: The radionuclides {sup 46}Sc and {sup 153}Sm were produced with specific activities of 100 and 430 MBq mg{sup -1}, respectively. High radiochemical yields were achieved and the hydrophilic radiocomplexes have shown high degree of binding to hydroxyapatite. Biodistribution studies at 1, 3 and 24 h of the 4 radiocomplexes under study, have showed a similar biodistribution profile with a relatively high bone uptake, slow clearance from blood and a very slow rate of total radioactivity excretion from the whole animal body. Conclusion: We have developed a new class of indazolebisphosphonates complexes with radioisotopes of samarium and scandium. All complexes have shown high degree of binding to hydroxyapatite, which could be attributed to the ionized phosphonate groups. The bone uptake and the bone-to-muscle ratios were relatively low.

  18. Complex analysis and geometry

    CERN Document Server

    Silva, Alessandro

    1993-01-01

    The papers in this wide-ranging collection report on the results of investigations from a number of linked disciplines, including complex algebraic geometry, complex analytic geometry of manifolds and spaces, and complex differential geometry.

  19. Complex Systems: An Introduction

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 9. Complex Systems: An Introduction - Anthropic Principle, Terrestrial Complexity, Complex Materials. V K Wadhawan. General Article Volume 14 Issue 9 September 2009 pp 894-906 ...

  20. Interaction of phosphorus pentachloride with trichlorides of metals of the second half of lanthanide series and scandium subgroup; Vzaimodejstvie pentakhlorida fosfora s trikhloridami metallov vtoroj poloviny semejstva lantanidov i podgruppy skandiya

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, A B; Vovkotrub, Eh G; Strekalovskij, V N [Inst. Vysokotemperaturnoj Ehlektrokhimii UrO RAN, Ekaterinburg (Russian Federation)

    1999-02-01

    With the use of Raman laser spectroscopy a study is made into interactions of molten TbCl{sub 3}, ErCl{sub 3}, YbCl{sub 3}, YCl{sub 3} and ScCl{sub 3} with phosphorus pentachloride vapors at elevated pressure (up to 30-35 atm) as well as solid REM trichlorides with molten PCl{sub 5}. It is revealed for first time that the interaction can be accompanied by reactions resulting in formation of complex chloride cations [PCl{sub 4}]{sup +} and anions [MCl{sub 6}]{sup 3-} of trivalent metals. The prediction is made about the possibility of chemical interaction of phosphorus pentachloride with trichlorides of all yttrium subgroup lanthanides under similar conditions.

  1. Complex differential geometry

    CERN Document Server

    Zheng, Fangyang

    2002-01-01

    The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...

  2. Complex and symplectic geometry

    CERN Document Server

    Medori, Costantino; Tomassini, Adriano

    2017-01-01

    This book arises from the INdAM Meeting "Complex and Symplectic Geometry", which was held in Cortona in June 2016. Several leading specialists, including young researchers, in the field of complex and symplectic geometry, present the state of the art of their research on topics such as the cohomology of complex manifolds; analytic techniques in Kähler and non-Kähler geometry; almost-complex and symplectic structures; special structures on complex manifolds; and deformations of complex objects. The work is intended for researchers in these areas.

  3. Oligocyclopentadienyl transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  4. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Among many applications of lanthanides, gadolinium complexes are used as magnetic resonance imaging (MRI) contrast agents in clinical radiology and luminescent lanthanides for bioanalysis, imaging and sensing. The chemistry of photoactive lanthanide complexes showing biological applications is of recent origin.

  5. ComplexRec 2017

    DEFF Research Database (Denmark)

    a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

  6. Complex Correspondence Principle

    International Nuclear Information System (INIS)

    Bender, Carl M.; Meisinger, Peter N.; Hook, Daniel W.; Wang Qinghai

    2010-01-01

    Quantum mechanics and classical mechanics are distinctly different theories, but the correspondence principle states that quantum particles behave classically in the limit of high quantum number. In recent years much research has been done on extending both quantum and classical mechanics into the complex domain. These complex extensions continue to exhibit a correspondence, and this correspondence becomes more pronounced in the complex domain. The association between complex quantum mechanics and complex classical mechanics is subtle and demonstrating this relationship requires the use of asymptotics beyond all orders.

  7. Uranium thiolate complexes

    International Nuclear Information System (INIS)

    Leverd, Pascal C.

    1994-01-01

    This research thesis proposes a new approach to the chemistry of uranium thiolate complexes as these compounds are very promising for various uses (in bio-inorganic chemistry, in some industrial processes like oil desulphurization). It more particularly addresses the U-S bond or more generally bonds between polarizable materials and hard metals. The author thus reports the study of uranium organometallic thiolates (tricyclo-penta-dienic and mono-cyclo-octa-tetraenylic complexes), and of uranium homoleptic thiolates (tetra-thiolate complexes, hexa-thiolate complexes, reactivity of homoleptic thiolate complexes) [fr

  8. Simplicial complexes of graphs

    CERN Document Server

    Jonsson, Jakob

    2008-01-01

    A graph complex is a finite family of graphs closed under deletion of edges. Graph complexes show up naturally in many different areas of mathematics, including commutative algebra, geometry, and knot theory. Identifying each graph with its edge set, one may view a graph complex as a simplicial complex and hence interpret it as a geometric object. This volume examines topological properties of graph complexes, focusing on homotopy type and homology. Many of the proofs are based on Robin Forman's discrete version of Morse theory. As a byproduct, this volume also provides a loosely defined toolbox for attacking problems in topological combinatorics via discrete Morse theory. In terms of simplicity and power, arguably the most efficient tool is Forman's divide and conquer approach via decision trees; it is successfully applied to a large number of graph and digraph complexes.

  9. On Complex Random Variables

    Directory of Open Access Journals (Sweden)

    Anwer Khurshid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable  is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of  have a complex univariate normal distribution. The characteristic function of  has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector  is Hermitian positive definite. Marginal distributions of  have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.

  10. Cobalt(III) complex

    Indian Academy of Sciences (India)

    Administrator

    e, 40 µM complex, 10 hrs after dissolution, f, 40 µM complex, after irradiation dose 15 Gy. and H-atoms result in reduction of Co(III) to Co. (II). 6. It is interesting to see in complex containing multiple ligands what is the fate of electron adduct species formed by electron addition. Reduction to. Co(II) and intramolecular transfer ...

  11. Complex Systems and Dependability

    CERN Document Server

    Zamojski, Wojciech; Sugier, Jaroslaw

    2012-01-01

    Typical contemporary complex system is a multifaceted amalgamation of technical, information, organization, software and human (users, administrators and management) resources. Complexity of such a system comes not only from its involved technical and organizational structure but mainly from complexity of information processes that must be implemented in the operational environment (data processing, monitoring, management, etc.). In such case traditional methods of reliability analysis focused mainly on technical level are usually insufficient in performance evaluation and more innovative meth

  12. Lanthanide complexes with pivaloylacetone

    International Nuclear Information System (INIS)

    Eliseeva, S.V.; Chugarov, N.V.; Kuz'mina, N.P.; Martynenko, L.I.; Nichiporuk, R.V.; Ivanov, S.A.

    2003-01-01

    Complexes Ln(pa) 3 ·2H 2 O (Ln=La, Gd, Lu, Hpa - pivaloylacetone) are synthesized and investigated by the methods of element, IR spectroscopic and thermal analyses. Behaviour of the complexes during heating in vacuum is compared with such one for acetylacetonates and dipivaloylmethanates. Structure of the complexes in solution is studied by 1 H NMR and MALDI-MS [ru

  13. Phospholyl-uranium complexes

    International Nuclear Information System (INIS)

    Gradoz, Philippe

    1993-01-01

    After having reported a bibliographical study on penta-methylcyclopentadienyl uranium complexes, and a description of the synthesis and radioactivity of uranium (III) and (IV) boron hydrides compounds, this research thesis reports the study of mono and bis-tetramethyl-phospholyl uranium complexes comprising chloride, boron hydride, alkyl and alkoxide ligands. The third part reports the comparison of structures, stabilities and reactions of homologue complexes in penta-methylcyclopentadienyl and tetramethyl-phospholyl series. The last part addresses the synthesis of tris-phospholyl uranium (III) and (IV) complexes. [fr

  14. Nuclear weapons complex

    International Nuclear Information System (INIS)

    Rezendes, V.S.

    1991-03-01

    In this book, GAO characterizes DOE's January 1991 Nuclear Weapons Complex Reconfiguration Study as a starting point for reaching agreement on solutions to many of the complex's safety and environmental problems. Key decisions still need to be made about the size of the complex, where to relocate plutonium operations, what technologies to use for new tritium production, and what to do with excess plutonium. The total cost for reconfiguring and modernizing the complex is still uncertain, and some management issues remain unresolved. Congress faces a difficult task in making test decisions given the conflicting demands for scarce resources in a time of growing budget deficits and war in the Persian Gulf

  15. Conducting metal dithiolate complexes

    DEFF Research Database (Denmark)

    Underhill, A. E.; Ahmad, M. M.; Turner, D. J.

    1985-01-01

    Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound......Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound...

  16. Ternary scandium-rich indides Sc{sub 50}T{sub 13}In{sub 3} and Sc{sub 50}Rh{sub 13}In{sub 3}O{sub y} (T = Rh, Ir; y {approx} 8) - synthesis and crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Zaremba, R.; Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Univ. Muenster (Germany)

    2007-12-15

    New intermetallic compounds Sc{sub 50}Rh{sub 13.3}In{sub 2.7} and Sc{sub 50}Ir{sub 13.6}In{sub 2.4} and the suboxides Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8} and Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0} were synthesized from the elements or with Sc{sub 2}O{sub 3} as an oxygen source, respectively, in sealed tantalum tubes in a water-cooled sample chamber of an induction furnace. They crystallize with a new cubic structure type, space group F m anti 3, a = 1772.5(6) pm, wR2 = 0.032, 1111 F{sup 2} values, 34 variables for Sc{sub 50}Rh{sub 13.3}In{sub 2.7}, a = 1766.5(6) pm, wR2 = 0.041, 745 F{sup 2} values, 34 variables for Sc{sub 50}Ir{sub 13.6}In{sub 2.4}, a = 1764.4(2) pm, wR2 = 0.044, 640 F{sup 2} values, 41 variables for Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8}, and a = 1761.5(6) pm, wR2 = 0.054, 740 F{sup 2} values, 42 variables for Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0}. The main structural motifs are rhodium-centered indium cubes in an fcc like arrangement in which the octahedral and tetrahedral voids are filled by In2Sc{sub 12} and In1Sc{sub 12} icosahedra, respectively, resembling a Li{sub 3}Bi-like structure. The Rh1 (Ir1) and Sc4 atoms lie between these polyhedral units. The oxygen atoms partially fill Sc{sub 6} octahedra in Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8} and Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0} with Sc-O distances of 214 - 230 pm. These octahedra are condensed via common edges and faces, encapsulating the In2Sc{sub 12} icosahedra. Due to the high scandium content one observes strong Sc-Sc bonding with Sc-Sc distances ranging from 303 to 362 pm in Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8}. The shortest distances occur for Sc-Rh (267 - 295 pm). The crystal chemical relationship with the Li{sub 3}Bi-related suboxide Ti{sub 12}Sn{sub 3}O{sub 10} is discussed. (orig.)

  17. Visual Complexity: A Review

    Science.gov (United States)

    Donderi, Don C.

    2006-01-01

    The idea of visual complexity, the history of its measurement, and its implications for behavior are reviewed, starting with structuralism and Gestalt psychology at the beginning of the 20th century and ending with visual complexity theory, perceptual learning theory, and neural circuit theory at the beginning of the 21st. Evidence is drawn from…

  18. Complexity in Picture Books

    Science.gov (United States)

    Sierschynski, Jarek; Louie, Belinda; Pughe, Bronwyn

    2015-01-01

    One of the key requirements of Common Core State Standards (CCSS) in English Language Arts is that students are able to read and access complex texts across all grade levels. The CCSS authors emphasize both the limitations and lack of accuracy in the current CCSS model of text complexity, calling for the development of new frameworks. In response…

  19. Method of complex scaling

    International Nuclear Information System (INIS)

    Braendas, E.

    1986-01-01

    The method of complex scaling is taken to include bound states, resonances, remaining scattering background and interference. Particular points of the general complex coordinate formulation are presented. It is shown that care must be exercised to avoid paradoxical situations resulting from inadequate definitions of operator domains. A new resonance localization theorem is presented

  20. Is dense codeswitching complex?

    NARCIS (Netherlands)

    Dorleijn, M.

    In this paper the question is raised to what extent dense code switching can be considered complex. Psycholinguistic experiments indicate that code switching involves cognitive costs, both in production and comprehension, a conclusion that could indicate that code switching is indeed complex. In

  1. Complex conductivity of soils

    NARCIS (Netherlands)

    Revil, A.; Coperey, A.; Shao, Z.; Florsch, N.; Fabricus, I.L.; Deng, Y.; Delsman, J.R.; Pauw, P.S.; Karaoulis, M.; Louw, P.G.B. de; Baaren, E.S. van; Dabekaussen, W.; Menkovic, A.; Gunnink, J.L.

    2017-01-01

    The complex conductivity of soils remains poorly known despite the growing importance of this method in hydrogeophysics. In order to fill this gap of knowledge, we investigate the complex conductivity of 71 soils samples (including four peat samples) and one clean sand in the frequency range 0.1 Hz

  2. Leading healthcare in complexity.

    Science.gov (United States)

    Cohn, Jeffrey

    2014-12-01

    Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization.

  3. Improved Efficacy of Synthesizing *MIII-Labeled DOTA Complexes in Binary Mixtures of Water and Organic Solvents. A Combined Radio- and Physicochemical Study.

    Science.gov (United States)

    Pérez-Malo, Marylaine; Szabó, Gergely; Eppard, Elisabeth; Vagner, Adrienn; Brücher, Ernő; Tóth, Imre; Maiocchi, Alessandro; Suh, Eul Hyun; Kovács, Zoltán; Baranyai, Zsolt; Rösch, Frank

    2018-05-21

    Typically, the synthesis of radiometal-based radiopharmaceuticals is performed in buffered aqueous solutions. We found that the presence of organic solvents like ethanol increased the radiolabeling yields of [ 68 Ga]Ga-DOTA (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacatic acid). In the present study, the effect of organic cosolvents [ethanol (EtOH), isopropyl alcohol, and acetonitrile] on the radiolabeling yields of the macrocyclic chelator DOTA with several trivalent radiometals (gallium-68, scandium-44, and lutetium-177) was systematically investigated. Various binary water (H 2 O)/organic solvent mixtures allowed the radiolabeling of DOTA at a significantly lower temperature than 95 °C, which is relevant for the labeling of sensitive biological molecules. Simultaneously, much lower amounts of the chelators were required. This strategy may have a fundamental impact on the formulation of trivalent radiometal-based radiopharmaceuticals. The equilibrium properties and formation kinetics of [M(DOTA)] - (M III = Ga III , Ce III , Eu III , Y III , and Lu III ) complexes were investigated in H 2 O/EtOH mixtures (up to 70 vol % EtOH). The protonation constants of DOTA were determined by pH potentiometry in H 2 O/EtOH mixtures (0-70 vol % EtOH, 0.15 M NaCl, 25 °C). The log K 1 H and log K 2 H values associated with protonation of the ring N atoms decreased with an increase of the EtOH content. The formation rates of [M(DOTA)] - complexes increase with an increase of the pH and [EtOH]. Complexation occurs through rapid formation of the diprotonated [M(H 2 DOTA)] + intermediates, which are in equilibrium with the kinetically active monoprotonated [M(HDOTA)] intermediates. The rate-controlling step is deprotonation (and rearrangement) of the monoprotonated intermediate, which occurs through H 2 O ( *M(HL) k H 2 O ) and OH - ( *M(HL) k OH ) assisted reaction pathways. The rate constants are essentially independent of the EtOH concentration, but the M(HL) k H2O

  4. The spectrum of singly ionized scandium, Sc II

    International Nuclear Information System (INIS)

    Johansson, S.; Litzen, U.

    1980-01-01

    The Sc II spectrum, emitted from a pulsed hollow-cathode discharge, has been studied in the region 1100-11 000 A, where 777 lines have been classified. 168 levels are now known, belonging to configurations of the types 3dnl, 4snl and 4p 2 . Parametric studies have been made for a number of configurations. A determination of the ionization limit from the configurations 3d4f, 5f and 5g gives the value 103 237.1+-2 cm -1 . (Auth.)

  5. Hydrogen-isotope motion in scandium studied by ultrasonic measurements

    International Nuclear Information System (INIS)

    Leisure, R.G.; Schwarz, R.B.; Migliori, A.; Torgeson, D.R.; Svare, I.

    1993-01-01

    Resonant ultrasound spectroscopy has been used to investigate ultrasonic attenuation in single crystals of Sc, ScH 0.25 , and ScD 0.18 over the temperature range of 10--300 K for frequencies near 1 MHz. Ultrasonic-attenuation peaks were observed in the samples containing H or D with the maximum attenuation occurring near 25 K for ScH 0.25 and near 50 K for ScD 0.18 . The general features of the data suggest that the motion reflected in the ultrasonic attenuation is closely related to the low-temperature motion seen in nulcear-magnetic-resonance spin-lattice-relaxation measurements. The ultrasonic results were fit with a two-level-system (TLS) model involving tunneling between highly asymmetric sites. The relaxation of the TLS was found to consist of two parts: a weakly temperature-dependent part, probably due to coupling to electrons; and a much more strongly temperature-dependent part, attributed to multiple-phonon processes. The strongly temperature-dependent part was almost two orders of magnitude faster in ScH 0.25 than in ScD 0.18 , in accordance with the idea that tunneling is involved in the motion. Surprisingly, the weakly temperature-dependent part was found to be about the same for the two isotopes. The asymmetries primarily responsible for coupling the TLS to the ultrasound are attributed to interactions between hydrogen ions that lie on adjacent c axes. The results are consistent with an isotope-independent strength for the coupling of the TLS to the ultrasound

  6. Scandium doped Strontium Titanate Ceramics: Structure, Microstructure, and Dielectric Properties

    Directory of Open Access Journals (Sweden)

    Tkach, Alexander

    2008-08-01

    Full Text Available Sc-doped strontium titanate (ST ceramics were synthesised by solid state reaction, according to the composition Sr1-1.5xScxTiO3 with x = 0-0.01. Structural properties and microstructure development was examined by XRD and SEM. The dielectric properties were evaluated as a function of the temperature and frequency in the radio frequency range. Lattice parameter, density and grain size, were found to decrease slightly with increasing Sc content. The dielectric permittivity and losses decrease also. Sc-doping has only a weak effect on the quantum paraelectric behaviour of ST and no dielectric anomaly was observed, what is probably related to the limited solubility of Sc on the Sr site of the perovskite lattice of ST.

    Se sintetizaron materiales cerámicos de titanato de estroncio dopado con escandio mediante reacción en estado sólido De acuerdo a la composición Sr1-1.5xScxTiO3 con x= 0-0.1. Las propiedades estructurales y el desarrollo microestructural se estudiaron mediante XRD y SEM. La propiedades dieléctricas se estudiaron como función de la temperatura y de la frecuencia en el rango de la frecuencias de radio. Se observó que los parámetros de red, la densidad y el tamaño del grano disminuyen ligeramente con el contenido en Sc. La permitividad dieléctrica y las perdidas también disminuyen. El dopado con Sc tiene un efecto muy ligero sobre el comportamiento paraeléctrico cuántico del titanato de estroncio y no se observó anomalías dioeléctricas , lo que está probablemente relacionado con la baja solubilidad del Sc en posiciones del Sr en la estructura tipo perovskita del titanato de estroncio.

  7. Gadolinium scandium germanide, Gd2Sc3Ge4

    Directory of Open Access Journals (Sweden)

    Sumohan Misra

    2009-04-01

    Full Text Available Gd2Sc3Ge4 adopts the orthorhombic Pu5Rh4-type structure. The crystal structure contains six sites in the asymmetric unit: two sites are statistically occupied by rare-earth atoms with Gd:Sc ratios of 0.967 (4:0.033 (4 and 0.031 (3:0.969 (3, one site (.m. symmetry is occupied by Sc atoms, and three distinct sites (two of which with .m. symmetry are occupied by Ge atoms. The rare-earth atoms form two-dimensional slabs with Ge atoms occupying the trigonal-prismatic voids.

  8. A scandium calibration source for the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Boeltzig, Axel; Barros, Nuno; Krueger, Felix; Krosigk, Belina von; Lozza, Valentina; Neumann, Laura; Petzoldt, Johannes; Soerensen, Arnd; Zuber, Kai [TU Dresden (Germany)

    2013-07-01

    The SNO+ experiment is the successor of SNO (Sudbury Neutrino Observatory), for which the detector will be filled with liquid scintillator. Located 2 km underground (equivalent to a shielding of about 6 km of water) in a mine near Sudbury, Canada, SNO+ will be a low-background experiment studying different aspects of neutrinos. The SNO+ detector calibration is scheduled to begin in mid-2013 with a water-filled detector and in 2014 filled with liquid scintillator. One of the sources designated for this calibration will use the γ rays following the beta decay of {sup 48}Sc. The sum of their energies is 3.333 MeV for the main decay branch, which is close to Q=3.371 MeV for the neutrino-less double beta decay of {sup 150}Nd that SNO+ plans to investigate. Due to the {sup 48}Sc half-life of 43.67 h, the source has to be produced shortly before the calibration via (n,p) reactions on {sup 48}Ti. Safety, radiopurity and cleanliness are further important issues for its application. The current status of the source development will be presented.

  9. The solidification behavior of dilute aluminium-scandium alloys

    International Nuclear Information System (INIS)

    Norman, A.F.; Prangnell, P.B.; McEwen, R.S.

    1998-01-01

    The solidification behavior of dilute Sc containing Al alloys has been investigated. In binary Al-Sc alloys, Sc additions greater than the eutectic composition (0.55 wt%) were found to produce a remarkable refinement in the grain size of aluminum castings, of two orders of magnitude, due to the formation of the primary Al 3 Sc intermetallic phase during solidification. The refinement in grain size only occurred in hypereutectic compositions and was shown to be far greater than can be achieved by conventional Al grain refiners. Grain refinement by the addition of Sc is accompanied by a change in growth morphology from dendritic, in the large unrefined grains, to fine spherical grains with a divorced eutectic appearing on the grain boundaries in the refined castings. Similar levels of refinement were observed in Al-Sc-Zr and Al-Cu-Sc alloys. In the latter, a change in the segregation behavior of Cu was observed, from a strongly interdendritic segregation pattern to a more homogeneous distribution. The supersaturated Al-Sc solid solution can decompose via a discontinuous precipitation reaction to form coherent rod-like precipitates of the L1 2 Al 3 Sc phase

  10. Oxidation of scandium thin films on tungsten surface

    International Nuclear Information System (INIS)

    Gorodetskij, D.A.; Martynyuk, A.V.

    1988-01-01

    Presence of Sc on the surface of W in amounts larger than a monolayer coverage leads to a decrease of the work function at the initial oxidation stage, which is attributed to oxygen implantation into the surface layer of the metal. A subsequent oxidation is followed by the formation on the surface of a thin oxide layer and an increase of the work function. An increase of the amount of Sc deposited on the surface before the oxidation decreases the work function of the obtained oxide from 5.8 (clean W surface) down to 3.3 eV (thick Sc layer on W)

  11. Selenophene transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    White, Carter James [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the η5- and the η1(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The 77Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of η1(S)-bound thiophenes, η1(S)-benzothiophene and η1(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the η1(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh3)Re(2-benzothioenylcarbene)]O3SCF3 was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the η1(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.

  12. Study of complex modes

    International Nuclear Information System (INIS)

    Pastrnak, J.W.

    1986-01-01

    This eighteen-month study has been successful in providing the designer and analyst with qualitative guidelines on the occurrence of complex modes in the dynamics of linear structures, and also in developing computer codes for determining quantitatively which vibration modes are complex and to what degree. The presence of complex modes in a test structure has been verified. Finite element analysis of a structure with non-proportional dumping has been performed. A partial differential equation has been formed to eliminate possible modeling errors

  13. Nuclear weapons complex

    International Nuclear Information System (INIS)

    Rezendes, V.S.

    1992-04-01

    In addition to long-standing safety and environmental problems plaguing the nuclear weapons complex, this paper reports that the Department of Energy (DOE) faces a major new challenge-how to reconfigure the weapons complex to meet the nation's defense needs in the 21st century. Key decisions still need to be made about the size of the complex; where, if necessary, to relocate various operations; what technologies to use for new tritium production; and what to do with excess weapons-grade material. The choices confronting DOE and Congress are difficult given the conflicting demands for limited resources

  14. Managing complex child law

    DEFF Research Database (Denmark)

    Svendsen, Idamarie Leth

    2017-01-01

    The article reports the findings of a qualitative study of Danish legal regulation of the public initial assessment of children and young persons and municipal practitioners’ decision-making under this regulation. The regulation mirrors new and complex relations between families and society...... in the form of 7 individual vignette interviews with municipal mid-level managers and professional consultants in five Danish municipalities. The study finds that the regulation is more complex than it looks, and that the complexity is handled through simplifying decision-making patterns that can be seen...

  15. Indicators: Physical Habitat Complexity

    Science.gov (United States)

    Physical habitat complexity measures the amount and variety of all types of cove at the water’s edge in lakes. In general, dense and varied shoreline habitat is able to support more diverse communities of aquatic life.

  16. Several complex variables

    International Nuclear Information System (INIS)

    Field, M.J.

    1976-01-01

    Topics discussed include the elementary of holomorphic functions of several complex variables; the Weierstrass preparation theorem; meromorphic functions, holomorphic line bundles and divisors; elliptic operators on compact manifolds; hermitian connections; the Hodge decomposition theorem. ( author)

  17. Power grid complexity

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Shengwei; Zhang, Xuemin [Tsinghua Univ., Beijing, BJ (China). Dept. of Electrical Engineering; Cao, Ming [Groningen Univ. (Netherlands). Faculty of Mathematics and Natural Sciences

    2011-07-01

    ''Power Grid Complexity'' introduces the complex system theory known as self-organized criticality (SOC) theory and complex network theory, and their applications to power systems. It studies the network characteristics of power systems, such as their small-world properties, structural vulnerability, decomposition and coordination strategies, and simplification and equivalence methods. The book also establishes four blackout models based on SOC theory through which the SOC of power systems is studied at both the macroscopic and microscopic levels. Additionally, applications of complex system theory in power system planning and emergency management platforms are also discussed in depth. This book can serve as a useful reference for engineers and researchers working with power systems. (orig.)

  18. Statistical electromagnetics: Complex cavities

    NARCIS (Netherlands)

    Naus, H.W.L.

    2008-01-01

    A selection of the literature on the statistical description of electromagnetic fields and complex cavities is concisely reviewed. Some essential concepts, for example, the application of the central limit theorem and the maximum entropy principle, are scrutinized. Implicit assumptions, biased

  19. Complex and unpredictable Cardano

    Science.gov (United States)

    Ekert, Artur

    2008-08-01

    This purely recreational paper is about one of the most colorful characters of the Italian Renaissance, Girolamo Cardano, and the discovery of two basic ingredients of quantum theory, probability and complex numbers.

  20. Coxeter-like complexes

    Directory of Open Access Journals (Sweden)

    Eric Babson

    2004-12-01

    Full Text Available Motivated by the Coxeter complex associated to a Coxeter system (W,S, we introduce a simplicial regular cell complex Δ(G,S with a G-action associated to any pair (G,S where G is a group and S is a finite set of generators for G which is minimal with respect to inclusion. We examine the topology of Δ(G,S, and in particular the representations of G on its homology groups. We look closely at the case of the symmetric group S n minimally generated by (not necessarily adjacent transpositions, and their type-selected subcomplexes. These include not only the Coxeter complexes of type A, but also the well-studied chessboard complexes.

  1. Physical Sciences Complex

    Data.gov (United States)

    Federal Laboratory Consortium — This 88,000 square foot complex is used to investigate basic physical science in support of missile technology development. It incorporates office space, dedicated...

  2. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    tinual increase in the diversity of life over evolutionary time. Ways of ... Centre for Ecological. Scienc'es .... plants evolved flowers to attract pollinators and reward them with .... with the evolving complexity of their interactions in communi- ties.

  3. Complex Flow Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-05-01

    This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.

  4. Complexity for Artificial Substrates (

    NARCIS (Netherlands)

    Loke, L.H.L.; Jachowski, N.R.; Bouma, T.J.; Ladle, R.J.; Todd, P.A.

    2014-01-01

    Physical habitat complexity regulates the structure and function of biological communities, although the mechanisms underlying this relationship remain unclear. Urbanisation, pollution, unsustainable resource exploitation and climate change have resulted in the widespread simplification (and loss)

  5. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 ... complexes showing photoactivated DNA cleavage activity and cytotoxicity in cancer cells. .... considerable importance for their selectivity in killing.

  6. Complex Networks IX

    CERN Document Server

    Coronges, Kate; Gonçalves, Bruno; Sinatra, Roberta; Vespignani, Alessandro; Proceedings of the 9th Conference on Complex Networks; CompleNet 2018

    2018-01-01

    This book aims to bring together researchers and practitioners working across domains and research disciplines to measure, model, and visualize complex networks. It collects the works presented at the 9th International Conference on Complex Networks (CompleNet) 2018 in Boston, MA in March, 2018. With roots in physical, information and social science, the study of complex networks provides a formal set of mathematical methods, computational tools and theories to describe prescribe and predict dynamics and behaviors of complex systems. Despite their diversity, whether the systems are made up of physical, technological, informational, or social networks, they share many common organizing principles and thus can be studied with similar approaches. This book provides a view of the state-of-the-art in this dynamic field and covers topics such as group decision-making, brain and cellular connectivity, network controllability and resiliency, online activism, recommendation systems, and cyber security.

  7. Provability, complexity, grammars

    CERN Document Server

    Beklemishev, Lev; Vereshchagin, Nikolai

    1999-01-01

    The book contains English translations of three outstanding dissertations in mathematical logic and complexity theory. L. Beklemishev proves that all provability logics must belong to one of the four previously known classes. The dissertation of M. Pentus proves the Chomsky conjecture about the equivalence of two approaches to formal languages: the Chomsky hierarchy and the Lambek calculus. The dissertation of N. Vereshchagin describes a general framework for criteria of reversability in complexity theory.

  8. Conversation, coupling and complexity

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Abney, Drew; Bahrami, Bahador

    We investigate the linguistic co-construction of interpersonal synergies. By applying a measure of coupling between complex systems to an experimentally elicited corpus of joint decision dialogues, we show that interlocutors’ linguistic behavior displays increasing signature of multi-scale coupling......, known as complexity matching, over the course of interaction. Furthermore, we show that stronger coupling corresponds with more effective interaction, as measured by collective task performance....

  9. Advances in network complexity

    CERN Document Server

    Dehmer, Matthias; Emmert-Streib, Frank

    2013-01-01

    A well-balanced overview of mathematical approaches to describe complex systems, ranging from chemical reactions to gene regulation networks, from ecological systems to examples from social sciences. Matthias Dehmer and Abbe Mowshowitz, a well-known pioneer in the field, co-edit this volume and are careful to include not only classical but also non-classical approaches so as to ensure topicality. Overall, a valuable addition to the literature and a must-have for anyone dealing with complex systems.

  10. Electrospun complexes - functionalised nanofibres

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, T.; Wolf, M.; Dreyer, B.; Unruh, D.; Krüger, C.; Menze, M. [Leibniz University Hannover, Institute of Inorganic Chemistry (Germany); Sindelar, R. [University of Applied Science Hannover, Faculty II (Germany); Klingelhöfer, G. [Gutenberg-University, Institute of Inorganic and Analytic Chemistry (Germany); Renz, F., E-mail: renz@acd.uni-hannover.de [Leibniz University Hannover, Institute of Inorganic Chemistry (Germany)

    2016-12-15

    Here we present a new approach of using iron-complexes in electro-spun fibres. We modify poly(methyl methacrylate) (PMMA) by replacing the methoxy group with Diaminopropane or Ethylenediamine. The complex is bound covalently via an imine-bridge or an amide. The resulting polymer can be used in the electrospinning process without any further modifications in method either as pure reagent or mixed with small amounts of not functionalised polymer resulting in fibres of different qualities (Fig. 1).

  11. MANAGEMENT OF SPORT COMPLEXES

    Directory of Open Access Journals (Sweden)

    Marian STAN

    2015-07-01

    Full Text Available The actuality of the investigated theme. Nowadays, human evolution, including his intellectual development, proves the fact that especially the creation manpower and the employment was the solution of all life’s ambitions in society. So, the fact is that in reality, man is the most important capital of the society. Also, in an individual’s life, the practice of sport plays a significant role and that’s why the initiation, the launch and the management of sports complexes activity reveal the existence of specific management features that we will identify and explain in the current study. The aim of the research refers to the elaboration of a theoretical base of the management of the sport complexes, to the pointing of the factors that influence the efficient existence and function of a sport complex in our country and to the determination of the responsibilities that have a manager who directs successfully the activity of the sport complexes. The investigation is based on theoretical methods, such as: scientific documentation, analysis, synthesis, comparison and on empirical research methods, like: study of researched literature and observation. The results of the research indicate the fact that the profitability of a sport complex must assure a particular structure to avoid the bankruptcy risk and also, that the administration of the sport complexes activity must keep in view the reliable functions of the contemporaneous management.

  12. Organotin complexes with phosphines

    International Nuclear Information System (INIS)

    Passos, B. de F.T.; Jesus Filho, M.F. de; Filgueiras, C.A.L.; Abras, A.

    1988-01-01

    A series of organotin complexes was prepared involving phosphines bonded to the organotin moiety. The series include derivatives of SnCl x Ph 4-x (where x varied from zero to four with the phosphines Ph 3 P, (Ph 2 P)CH 2 , (Ph 2 P) 2 (CH 2 ) 2 , cis-(Ph 2 P)CH 2 , and CH 3 C(CH 2 PPh 2 ) 3 . A host of new complexes was obtained, showing different stoichiometries, bonding modes, and coordination numbers around the tin atom. These complexes were characterized by several different chemical and physical methods. The 119 Sn Moessbauer parameters varied differently. Whereas isomer shift values did not great variation for each group of complexs with the same organotin parent (SnCl x Ph 4-x ), reflecting a small change in s charge distribution on the Sn atom upon complexation, quadrupole splitting results varied widely, however, when the parent organotin compound was wholly symmetric (SnCl 4 and SnPPh 4 ), the complexes also tended to show quadrupole splitting values approaching zero. (author)

  13. Hypoxia targeting copper complexes

    International Nuclear Information System (INIS)

    Dearling, J.L.

    1998-11-01

    The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes ( 64 Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective 64 Cu(II)ATSM to normoxic cell selective 64 Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential, with hypoxia

  14. Complexity and Dynamical Depth

    Directory of Open Access Journals (Sweden)

    Terrence Deacon

    2014-07-01

    Full Text Available We argue that a critical difference distinguishing machines from organisms and computers from brains is not complexity in a structural sense, but a difference in dynamical organization that is not well accounted for by current complexity measures. We propose a measure of the complexity of a system that is largely orthogonal to computational, information theoretic, or thermodynamic conceptions of structural complexity. What we call a system’s dynamical depth is a separate dimension of system complexity that measures the degree to which it exhibits discrete levels of nonlinear dynamical organization in which successive levels are distinguished by local entropy reduction and constraint generation. A system with greater dynamical depth than another consists of a greater number of such nested dynamical levels. Thus, a mechanical or linear thermodynamic system has less dynamical depth than an inorganic self-organized system, which has less dynamical depth than a living system. Including an assessment of dynamical depth can provide a more precise and systematic account of the fundamental difference between inorganic systems (low dynamical depth and living systems (high dynamical depth, irrespective of the number of their parts and the causal relations between them.

  15. The Orion complex

    International Nuclear Information System (INIS)

    Goudis, C.

    1982-01-01

    This work deals with some of the most typical complexes of interstellar matter and presents a holistic view of the well studied complexes in Orion, built on information derived from various branches of modern astrophysics. A wealth of published data is presented in the form of photographs, contour maps, diagrams and numerous heavily annotated tables. Chapter 1, which is concerned with the large scale view of the Orion region, outlines the morphology of the area and examines in particular the nature of Barnard's Loop and the associated filamentary structure in addition to the origin of the I Orion OB association. Chapter 2 focuses on the Great Orion Nebula (M42 or NGC 1976) and the small H II region to the north (M43 or NGC 1982). Chapter 3 examines the Orion Complex as a whole, i.e. the H II regions M42 and M43, the associated molecular clouds OMC 1 and OMC 2 and their interrelations. Chapter 4 contains a discussion of the empirical models introduced to attempt to explain certain aspects of this very complex region, and chapter 5 investigates the second prominent H II region and molecular cloud complex, NGC 2024 (Orion B, W12). (Auth.)

  16. Complexity of Economical Systems

    Directory of Open Access Journals (Sweden)

    G. P. Pavlos

    2015-01-01

    Full Text Available In this study new theoretical concepts are described concerning the interpretation of economical complex dynamics. In addition a summary of an extended algorithm of nonlinear time series analysis is provided which is applied not only in economical time series but also in other physical complex systems (e.g. [22, 24]. In general, Economy is a vast and complicated set of arrangements and actions wherein agents—consumers, firms, banks, investors, government agencies—buy and sell, speculate, trade, oversee, bring products into being, offer services, invest in companies, strategize, explore, forecast, compete, learn, innovate, and adapt. As a result the economic and financial variables such as foreign exchange rates, gross domestic product, interest rates, production, stock market prices and unemployment exhibit large-amplitude and aperiodic fluctuations evident in complex systems. Thus, the Economics can be considered as spatially distributed non-equilibrium complex system, for which new theoretical concepts, such as Tsallis non extensive statistical mechanics and strange dynamics, percolation, nonGaussian, multifractal and multiscale dynamics related to fractional Langevin equations can be used for modeling and understanding of the economical complexity locally or globally.

  17. Complexes and imagination.

    Science.gov (United States)

    Kast, Verena

    2014-11-01

    Fantasies as imaginative activities are seen by Jung as expressions of psychic energy. In the various descriptions of active imagination the observation of the inner image and the dialogue with inner figures, if possible, are important. The model of symbol formation, as Jung describes it, can be experienced in doing active imagination. There is a correspondence between Jung's understanding of complexes and our imaginations: complexes develop a fantasy life. Complex episodes are narratives of difficult dysfunctional relationship episodes that have occurred repeatedly and are internalized with episodic memory. This means that the whole complex episode (the image for the child and the image for the aggressor, connected with emotions) is internalized and can get constellated in everyday relationship. Therefore inner dialogues do not necessarily qualify as active imaginations, often they are the expression of complex-episodes, very similar to fruitless soliloquies. If imaginations of this kind are repeated, new symbols and new possibilities of behaviour are not found. On the contrary, old patterns of behaviour and fantasies are perpetuated and become cemented. Imaginations of this kind need an intervention by the analyst. In clinical examples different kinds of imaginations are discussed. © 2014, The Society of Analytical Psychology.

  18. Algorithmic Relative Complexity

    Directory of Open Access Journals (Sweden)

    Daniele Cerra

    2011-04-01

    Full Text Available Information content and compression are tightly related concepts that can be addressed through both classical and algorithmic information theories, on the basis of Shannon entropy and Kolmogorov complexity, respectively. The definition of several entities in Kolmogorov’s framework relies upon ideas from classical information theory, and these two approaches share many common traits. In this work, we expand the relations between these two frameworks by introducing algorithmic cross-complexity and relative complexity, counterparts of the cross-entropy and relative entropy (or Kullback-Leibler divergence found in Shannon’s framework. We define the cross-complexity of an object x with respect to another object y as the amount of computational resources needed to specify x in terms of y, and the complexity of x related to y as the compression power which is lost when adopting such a description for x, compared to the shortest representation of x. Properties of analogous quantities in classical information theory hold for these new concepts. As these notions are incomputable, a suitable approximation based upon data compression is derived to enable the application to real data, yielding a divergence measure applicable to any pair of strings. Example applications are outlined, involving authorship attribution and satellite image classification, as well as a comparison to similar established techniques.

  19. Nuclear weapons complex

    International Nuclear Information System (INIS)

    Peach, J.D.

    1991-02-01

    In this paper, GAO provides its views on DOE's January 1991 Nuclear Weapons Complex Reconfiguration Study. GAO believes that DOE's new reconfiguration study provides a starting point for reaching agreement on solutions to many of the complex's problems. Key decisions still need to be made about the size of the complex, where to relocate plutonium operations, what technologies should be used for new tritium production, and what to do with excess plutonium. The total cost for reconfiguring and modernizing is still uncertain and some management issues remain unresolved. Congress faces a difficult task in making these decisions given the conflicting demands for scare resources in a time of growing budget deficits and war in the Persian Gulf

  20. Can Complexity be Planned?

    Directory of Open Access Journals (Sweden)

    Ilona Koutny

    2015-04-01

    Full Text Available The long accepted complexity invariance of human languages has become controversial within the last decade. In investigations of the problem, both creole and planned languages have often been neglected. After a presentation of the scope of the invariance problem and the proposition of the natural to planned language continuum, this article will discuss the contribution of planned languages. It will analyze the complexity of Esperanto at the phonological, morphological, syntactic and semantic levels, using linguistic data bases. The role of the L2 speech community and development of the language will also be taken into account when discussing the endurance of the same level of simplicity of this planned international language. The author argues that complexity can be variable and to some extent planned and maintained.

  1. Introduction to complex plasmas

    International Nuclear Information System (INIS)

    Bonitz, Michael; Ludwig, Patrick; Horing, Norman

    2010-01-01

    Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates. (orig.)

  2. Introduction to Complex Plasmas

    CERN Document Server

    Bonitz, Michael; Ludwig, Patrick

    2010-01-01

    Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates.

  3. BRAND program complex

    International Nuclear Information System (INIS)

    Androsenko, A.A.; Androsenko, P.A.

    1983-01-01

    A description is given of the structure, input procedure and recording rules of initial data for the BRAND programme complex intended for the Monte Carlo simulation of neutron physics experiments. The BRAND complex ideology is based on non-analogous simulation of the neutron and photon transport process (statistic weights are used, absorption and escape of particles from the considered region is taken into account, shifted readouts from a coordinate part of transition nucleus density are applied, local estimations, etc. are used). The preparation of initial data for three sections is described in detail: general information for Monte Carlo calculation, source definition and data for describing the geometry of the system. The complex is to be processed with the BESM-6 computer, the basic programming lan-- guage is FORTRAN, volume - more than 8000 operators

  4. Synchronization in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.

    2007-12-12

    Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.

  5. Simulation in Complex Modelling

    DEFF Research Database (Denmark)

    Nicholas, Paul; Ramsgaard Thomsen, Mette; Tamke, Martin

    2017-01-01

    This paper will discuss the role of simulation in extended architectural design modelling. As a framing paper, the aim is to present and discuss the role of integrated design simulation and feedback between design and simulation in a series of projects under the Complex Modelling framework. Complex...... performance, engage with high degrees of interdependency and allow the emergence of design agency and feedback between the multiple scales of architectural construction. This paper presents examples for integrated design simulation from a series of projects including Lace Wall, A Bridge Too Far and Inflated...... Restraint developed for the research exhibition Complex Modelling, Meldahls Smedie Gallery, Copenhagen in 2016. Where the direct project aims and outcomes have been reported elsewhere, the aim for this paper is to discuss overarching strategies for working with design integrated simulation....

  6. Modeling Complex Systems

    CERN Document Server

    Boccara, Nino

    2010-01-01

    Modeling Complex Systems, 2nd Edition, explores the process of modeling complex systems, providing examples from such diverse fields as ecology, epidemiology, sociology, seismology, and economics. It illustrates how models of complex systems are built and provides indispensable mathematical tools for studying their dynamics. This vital introductory text is useful for advanced undergraduate students in various scientific disciplines, and serves as an important reference book for graduate students and young researchers. This enhanced second edition includes: . -recent research results and bibliographic references -extra footnotes which provide biographical information on cited scientists who have made significant contributions to the field -new and improved worked-out examples to aid a student’s comprehension of the content -exercises to challenge the reader and complement the material Nino Boccara is also the author of Essentials of Mathematica: With Applications to Mathematics and Physics (Springer, 2007).

  7. The multitalented Mediator complex.

    Science.gov (United States)

    Carlsten, Jonas O P; Zhu, Xuefeng; Gustafsson, Claes M

    2013-11-01

    The Mediator complex is needed for regulated transcription of RNA polymerase II (Pol II)-dependent genes. Initially, Mediator was only seen as a protein bridge that conveyed regulatory information from enhancers to the promoter. Later studies have added many other functions to the Mediator repertoire. Indeed, recent findings show that Mediator influences nearly all stages of transcription and coordinates these events with concomitant changes in chromatin organization. We review the multitude of activities associated with Mediator and discuss how this complex coordinates transcription with other cellular events. We also discuss the inherent difficulties associated with in vivo characterization of a coactivator complex that can indirectly affect diverse cellular processes via changes in gene transcription. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Modeling Complex Time Limits

    Directory of Open Access Journals (Sweden)

    Oleg Svatos

    2013-01-01

    Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

  9. Large erupted complex odontoma

    Directory of Open Access Journals (Sweden)

    Vijeev Vasudevan

    2009-01-01

    Full Text Available Odontomas are a heterogeneous group of jaw bone lesions, classified as odontogenic tumors which usually include well-diversified dental tissues. Odontoma is a term introduced to the literature by Broca in 1867. Trauma, infection and hereditary factors are the possible causes of forming this kind of lesions. Among odontogenic tumors, they constitute about 2/3 of cases. These lesions usually develop slowly and asymptomatically, and in most cases they do not cross the bone borders. Two types of odontoma are recognized: compound and complex. Complex odontomas are less common than the compound variety in the ratio 1:2.3. Eruption of an odontoma in the oral cavity is rare. We present a case of complex odontoma, in which apparent eruption has occurred in the area of the right maxillary second molar region.

  10. Alanine water complexes.

    Science.gov (United States)

    Vaquero, Vanesa; Sanz, M Eugenia; Peña, Isabel; Mata, Santiago; Cabezas, Carlos; López, Juan C; Alonso, José L

    2014-04-10

    Two complexes of alanine with water, alanine-(H2O)n (n = 1,2), have been generated by laser ablation of the amino acid in a supersonic jet containing water vapor and characterized using Fourier transform microwave spectroscopy. In the observed complexes, water molecules bind to the carboxylic group of alanine acting as both proton donors and acceptors. In alanine-H2O, the water molecule establishes two intermolecular hydrogen bonds forming a six-membered cycle, while in alanine-(H2O)2 the two water molecules establish three hydrogen bonds forming an eight-membered ring. In both complexes, the amino acid moiety is in its neutral form and shows the conformation observed to be the most stable for the bare molecule. The microsolvation study of alanine-(H2O)n (n = 1,2) can be taken as a first step toward understanding bulk properties at a microscopic level.

  11. Philosophy of complex systems

    CERN Document Server

    2011-01-01

    The domain of nonlinear dynamical systems and its mathematical underpinnings has been developing exponentially for a century, the last 35 years seeing an outpouring of new ideas and applications and a concomitant confluence with ideas of complex systems and their applications from irreversible thermodynamics. A few examples are in meteorology, ecological dynamics, and social and economic dynamics. These new ideas have profound implications for our understanding and practice in domains involving complexity, predictability and determinism, equilibrium, control, planning, individuality, responsibility and so on. Our intention is to draw together in this volume, we believe for the first time, a comprehensive picture of the manifold philosophically interesting impacts of recent developments in understanding nonlinear systems and the unique aspects of their complexity. The book will focus specifically on the philosophical concepts, principles, judgments and problems distinctly raised by work in the domain of comple...

  12. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    Dias, Kealey

    vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields.......The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...

  13. Complex manifolds in relativity

    International Nuclear Information System (INIS)

    Flaherty, E.J. Jr.

    1975-01-01

    Complex manifold theory is applied to the study of certain problems in general relativity. The first half of the work is devoted to the mathematical theory of complex manifold. Then a brief review of general relativity is given. It is shown that any spacetime admits locally an almost Hermitian structure, suitably modified to be compatible with the indefinite metric of spacetime. This structure is integrable if and only if the spacetime admits two geodesic and shearfree null congruences, thus in particular if the spacetime is type D vacuum or electrified. The structure is ''half-integrable'' in a suitable sense if and only if the spacetime admits one geodesic and shearfree null congruence, thus in particular for all algebraically special vacuum spacetimes. Conditions for the modified Hermitian spacetime to be Kahlerian are presented. The most general metric for such a modified Kahlerian spacetime is found. It is shown that the type D vacuum and electrified spacetimes are conformally related to modified Kahlerian spacetimes by a generally complex conformal factor. These latter are shown to possess a very rich structure, including the existence of Killing tensors and Killing vectors. A new ''explanation'' of Newman's complex coordinate transformations is given. It is felt to be superior to previous ''explanations'' on several counts. For example, a physical interpretation in terms of a symmetry group is given. The existence of new complex coordinate transformations is established: Nt is shown that any type D vacuum spacetime is obtainable from either Schwarzschild spacetime or ''C'' spacetime by a complex coordinate transformation. Finally, some related topics are discussed and areas for future work are outlined. (Diss. Abstr. Int., B)

  14. Complex quantum groups

    International Nuclear Information System (INIS)

    Drabant, B.; Schlieker, M.

    1993-01-01

    The complex quantum groups are constructed. They are q-deformations of the real Lie groups which are obtained as the complex groups corresponding to the Lie algebras of type A n-1 , B n , C n . Following the ideas of Faddeev, Reshetikhin and Takhtajan Hopf algebras of regular functionals U R for these complexified quantum groups are constructed. One has thus in particular found a construction scheme for the q-Lorentz algebra to be identified as U(sl q (2,C). (orig.)

  15. Complex function theory

    CERN Document Server

    Sarason, Donald

    2007-01-01

    Complex Function Theory is a concise and rigorous introduction to the theory of functions of a complex variable. Written in a classical style, it is in the spirit of the books by Ahlfors and by Saks and Zygmund. Being designed for a one-semester course, it is much shorter than many of the standard texts. Sarason covers the basic material through Cauchy's theorem and applications, plus the Riemann mapping theorem. It is suitable for either an introductory graduate course or an undergraduate course for students with adequate preparation. The first edition was published with the title Notes on Co

  16. Complex matrix model duality

    International Nuclear Information System (INIS)

    Brown, T.W.

    2010-11-01

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)

  17. Resilience and Complexity

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus

    2015-01-01

    This paper explores two key concepts: resilience and complexity. The first is understood as an emergent property of the latter, and their inter-relatedness is discussed using a three tier approach. First, by exploring the discourse of each concept, next, by analyzing underlying relationships and...... robust. Robustness is a property of simple or complicated systems characterized by predictable behavior, enabling the system to bounce back to its normal state following a perturbation. Resilience, however, is an emergent property of complex adaptive systems. It is suggested that this distinction...

  18. Theories of computational complexity

    CERN Document Server

    Calude, C

    1988-01-01

    This volume presents four machine-independent theories of computational complexity, which have been chosen for their intrinsic importance and practical relevance. The book includes a wealth of results - classical, recent, and others which have not been published before.In developing the mathematics underlying the size, dynamic and structural complexity measures, various connections with mathematical logic, constructive topology, probability and programming theories are established. The facts are presented in detail. Extensive examples are provided, to help clarify notions and constructions. The lists of exercises and problems include routine exercises, interesting results, as well as some open problems.

  19. Planning Complex Projects Automatically

    Science.gov (United States)

    Henke, Andrea L.; Stottler, Richard H.; Maher, Timothy P.

    1995-01-01

    Automated Manifest Planner (AMP) computer program applies combination of artificial-intelligence techniques to assist both expert and novice planners, reducing planning time by orders of magnitude. Gives planners flexibility to modify plans and constraints easily, without need for programming expertise. Developed specifically for planning space shuttle missions 5 to 10 years ahead, with modifications, applicable in general to planning other complex projects requiring scheduling of activities depending on other activities and/or timely allocation of resources. Adaptable to variety of complex scheduling problems in manufacturing, transportation, business, architecture, and construction.

  20. Complex matrix model duality

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.W.

    2010-11-15

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)

  1. Nonlinear dynamics and complexity

    CERN Document Server

    Luo, Albert; Fu, Xilin

    2014-01-01

    This important collection presents recent advances in nonlinear dynamics including analytical solutions, chaos in Hamiltonian systems, time-delay, uncertainty, and bio-network dynamics. Nonlinear Dynamics and Complexity equips readers to appreciate this increasingly main-stream approach to understanding complex phenomena in nonlinear systems as they are examined in a broad array of disciplines. The book facilitates a better understanding of the mechanisms and phenomena in nonlinear dynamics and develops the corresponding mathematical theory to apply nonlinear design to practical engineering.

  2. Complex/Symplectic Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Wu-yen; Kachru, Shamit; /Stanford U., ITP /SLAC; Tomasiello, Alessandro; /Stanford U., ITP

    2005-10-28

    We construct a class of symplectic non-Kaehler and complex non-Kaehler string theory vacua, extending and providing evidence for an earlier suggestion by Polchinski and Strominger. The class admits a mirror pairing by construction. Comparing hints from a variety of sources, including ten-dimensional supergravity and KK reduction on SU(3)-structure manifolds, suggests a picture in which string theory extends Reid's fantasy to connect classes of both complex non-Kaehler and symplectic non-Kaehler manifolds.

  3. Complex logistics audit system

    Directory of Open Access Journals (Sweden)

    Zuzana Marková

    2010-02-01

    Full Text Available Complex logistics audit system is a tool for realization of logistical audit in the company. The current methods for logistics auditare based on “ad hok” analysis of logisticsl system. This paper describes system for complex logistics audit. It is a global diagnosticsof logistics processes and functions of enterprise. The goal of logistics audit is to provide comparative documentation for managementabout state of logistics in company and to show the potential of logistics changes in order to achieve more effective companyperformance.

  4. Simulations with complex measure

    International Nuclear Information System (INIS)

    Markham, J.K.; Kieu, T.D.

    1997-01-01

    A method is proposed to handle the sign problem in the simulation of systems having indefinite or complex-valued measures. In general, this new approach, which is based on renormalisation blocking, is shown to yield statistical errors smaller that the crude Monte Carlo method using absolute values of the original measures. The improved method is applied to the 2D Ising model with temperature generalised to take on complex values. It is also adapted to implement Monte Carlo Renormalisation Group calculations of the magnetic and thermal critical exponents. 10 refs., 4 tabs., 7 figs

  5. Qubit Complexity of Continuous Problems

    National Research Council Canada - National Science Library

    Papageorgiou, A; Traub, J. F

    2005-01-01

    .... The authors show how to obtain the classical query complexity for continuous problems. They then establish a simple formula for a lower bound on the qubit complexity in terms of the classical query complexity...

  6. Prediction of Biomolecular Complexes

    KAUST Repository

    Vangone, Anna

    2017-04-12

    Almost all processes in living organisms occur through specific interactions between biomolecules. Any dysfunction of those interactions can lead to pathological events. Understanding such interactions is therefore a crucial step in the investigation of biological systems and a starting point for drug design. In recent years, experimental studies have been devoted to unravel the principles of biomolecular interactions; however, due to experimental difficulties in solving the three-dimensional (3D) structure of biomolecular complexes, the number of available, high-resolution experimental 3D structures does not fulfill the current needs. Therefore, complementary computational approaches to model such interactions are necessary to assist experimentalists since a full understanding of how biomolecules interact (and consequently how they perform their function) only comes from 3D structures which provide crucial atomic details about binding and recognition processes. In this chapter we review approaches to predict biomolecular complexesBiomolecular complexes, introducing the concept of molecular dockingDocking, a technique which uses a combination of geometric, steric and energetics considerations to predict the 3D structure of a biological complex starting from the individual structures of its constituent parts. We provide a mini-guide about docking concepts, its potential and challenges, along with post-docking analysis and a list of related software.

  7. Real and complex analysis

    CERN Document Server

    Apelian, Christopher; Taft, Earl; Nashed, Zuhair

    2009-01-01

    The Spaces R, Rk, and CThe Real Numbers RThe Real Spaces RkThe Complex Numbers CPoint-Set Topology Bounded SetsClassification of Points Open and Closed SetsNested Intervals and the Bolzano-Weierstrass Theorem Compactness and Connectedness Limits and Convergence Definitions and First Properties Convergence Results for SequencesTopological Results for Sequences Properties of Infinite SeriesManipulations of Series in RFunctions: Definitions and Limits DefinitionsFunctions as MappingsSome Elementary Complex FunctionsLimits of FunctionsFunctions: Continuity and Convergence Continuity Uniform Continuity Sequences and Series of FunctionsThe DerivativeThe Derivative for f: D1 → RThe Derivative for f: Dk → RThe Derivative for f: Dk → RpThe Derivative for f: D → CThe Inverse and Implicit Function TheoremsReal IntegrationThe Integral of f: [a, b] → RProperties of the Riemann Integral Further Development of Integration TheoryVector-Valued and Line IntegralsComplex IntegrationIntroduction to Complex Integrals Fu...

  8. Automatic Complexity Analysis

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    1989-01-01

    One way to analyse programs is to to derive expressions for their computational behaviour. A time bound function (or worst-case complexity) gives an upper bound for the computation time as a function of the size of input. We describe a system to derive such time bounds automatically using abstract...

  9. Complexity and ecology

    International Nuclear Information System (INIS)

    Gomez Giraldo, Luis Jair

    2002-01-01

    The present article examines the transformation that the construction of the theoretical body of ecology as a science has been going through since it first appeared in the XIX century within the logic of classical science until recent developments comprised within complex systemic. Mainly departing from the analysis from thermodynamics of irreversible phenomena

  10. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    , is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...

  11. Managing Complex Dynamical Systems

    Science.gov (United States)

    Cox, John C.; Webster, Robert L.; Curry, Jeanie A.; Hammond, Kevin L.

    2011-01-01

    Management commonly engages in a variety of research designed to provide insight into the motivation and relationships of individuals, departments, organizations, etc. This paper demonstrates how the application of concepts associated with the analysis of complex systems applied to such data sets can yield enhanced insights for managerial action.

  12. benzimidazole metal complexes

    Indian Academy of Sciences (India)

    aUnité de Recherche de Chimie de l'Environnement et Moléculaire Structurale, Université des Frères. Mentouri .... determine the quantum chemical parameters for the title ..... retical study of benzazole thioether and its zinc complex.

  13. COMPLEXITY AND UNIVERSITY

    Directory of Open Access Journals (Sweden)

    Edna Lemes Martins Pereira

    2013-12-01

    Full Text Available Economic globalization affects different countries on the globe, has positive effects mainly related to access to communication, which promotes the exchange of ideas, information, products and quality of life. However, extends numerous negative aspects such as marginalization, economic dependencies, political, cultural, scientific, educational accentuate social inequalities and cultural conflicts and territorial. In this article it is a dialogue with authors (Cunha 2009; BARNETT 2005; MORIN 1999, 2006, among others, who understand these changes in society from the contemporary world as conceived as the "Complexity era" or "supercomplexity". To understand and cope with this reality, they propose a paradigm that is able to overcome the fragmentation and reductionism of knowledge and to relate the multiple approaches and visions to meet the complexity of reality. Although this paper presents proposals to the aforementioned authors point to education and the university found in this tangle of interconnected global transformations, given the need to be subject to act in a complex reality that requires critical and self-critical professionals, able to think about their own ability to think, understand and act within this complex context.

  14. (VI) ML6 Complexes

    African Journals Online (AJOL)

    A geometric analysis revealed that beta-(C-H) and alpha-(C-C) can occupy the seventh and eighth coordination sites in the title Fischer carbene complexes as agostic interactions, which allows classifying the carbene as a η3 ligand in these cases. This theory was supported by the relative energies of the conformers and an ...

  15. The CERN accelerator complex

    CERN Multimedia

    Mobs, Esma Anais

    2016-01-01

    The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  16. The CERN accelerator complex

    CERN Multimedia

    Christiane Lefèvre

    2008-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  17. Nature, computation and complexity

    International Nuclear Information System (INIS)

    Binder, P-M; Ellis, G F R

    2016-01-01

    The issue of whether the unfolding of events in the world can be considered a computation is explored in this paper. We come to different conclusions for inert and for living systems (‘no’ and ‘qualified yes’, respectively). We suggest that physical computation as we know it exists only as a tool of complex biological systems: us. (paper)

  18. Complex Regional Pain Syndrome

    Science.gov (United States)

    Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. It may happen ... move the affected body part The cause of CRPS is unknown. There is no specific diagnostic test. ...

  19. Prediction of Biomolecular Complexes

    KAUST Repository

    Vangone, Anna; Oliva, Romina; Cavallo, Luigi; Bonvin, Alexandre M. J. J.

    2017-01-01

    Almost all processes in living organisms occur through specific interactions between biomolecules. Any dysfunction of those interactions can lead to pathological events. Understanding such interactions is therefore a crucial step in the investigation of biological systems and a starting point for drug design. In recent years, experimental studies have been devoted to unravel the principles of biomolecular interactions; however, due to experimental difficulties in solving the three-dimensional (3D) structure of biomolecular complexes, the number of available, high-resolution experimental 3D structures does not fulfill the current needs. Therefore, complementary computational approaches to model such interactions are necessary to assist experimentalists since a full understanding of how biomolecules interact (and consequently how they perform their function) only comes from 3D structures which provide crucial atomic details about binding and recognition processes. In this chapter we review approaches to predict biomolecular complexesBiomolecular complexes, introducing the concept of molecular dockingDocking, a technique which uses a combination of geometric, steric and energetics considerations to predict the 3D structure of a biological complex starting from the individual structures of its constituent parts. We provide a mini-guide about docking concepts, its potential and challenges, along with post-docking analysis and a list of related software.

  20. COMPLEX PROMOTIONSIN RETAIL

    Directory of Open Access Journals (Sweden)

    O. Yusupova

    2015-10-01

    Full Text Available Complex promotions used by retailers introduce to the consumers several rules that must be satisfied in order to get some benefits and usually refer to multiple products (e.g. “buy two, get one free”. Rules of complex promotions can be quite sophisticated and complicated themselves. Since diversity of complex promotions limited only by marketers’ imagination we can observe broad variety of promotions’ rules and representa¬tions of those rules in retailers’ commercials. Such diversification makes no good for fellow scientist who’s trying to sort all type of promotions into the neatly organized classification. Although we can simple add every single set of rules offered by retailers as a separate form of sales promotion it seems not to be the best way of dealing with such a problem. The better way is to realize that mechanisms underlying that variety of promotions are basically the same, namely changes in demand or quantity demanded. Those two concepts alone provide powerful insight into classification of complex promotions and allow us to comprehend the variety of promotions offered by marketers nowadays.

  1. Uranyl complexes of glutathione

    Energy Technology Data Exchange (ETDEWEB)

    Marzotto, A [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

    1977-01-01

    Dioxouranium(VI) complexes of the tripeptide glutathione having different molar ratios were prepared and studied by IR, PMR, electronic absorption and circular dichroism spectra. The results indicate that coordination occurs at the carboxylato groups, acting as monodentate ligands, whereas no significant interaction with the amino and sulfhydrylic groups takes place.

  2. Complexity and formative experiences

    Directory of Open Access Journals (Sweden)

    Roque Strieder

    2017-12-01

    Full Text Available The contemporaneity is characterized by instability and diversity calling into question certainties and truths proposed in modernity. We recognize that the reality of things and phenomena become effective as a set of events, interactions, retroactions and chances. This different frame extends the need for revision of the epistemological foundations that sustain educational practices and give them sense. The complex thinking is an alternative option for acting as a counterpoint to classical science and its reductionist logic and knowledge compartmentalization, as well as to answer to contemporary epistemological and educational challenges. It aims to associate different areas and forms of knowledge, without, however merge them, distinguishing without separating the several disciplines and instances of the realities. This study, in theoretical references, highlights the relevance of complex approaches to support formative experiences because also able to produce complexities in reflections about educational issues. We conclude that formative possibilities from complexity potentialize the resignification of human’s conception and the understanding of its singularity in interdependence; The understanding that pedagogical and educational activities is a constant interrogation about the possibilities of knowing the knowledge and reframe learning, far beyond knowing its functions and utilitarian purposes; and, as a formative possibility, places us on the trail of responsibility, not as something eventual, but present and indicative of freedom to choose to stay or go beyond.

  3. pyridine-carboxamide complexes

    Indian Academy of Sciences (India)

    of the solution was reduced by slow evaporation. The prod- uct was ... Data collection, data reduction, structure solu- ... and a selection of bond lengths and angles are shown in. Table 2. ...... Zn(II) complexes featuring a disulfide bridge and H-.

  4. Complexity driven photonics

    KAUST Repository

    Fratalocchi, Andrea

    2014-01-01

    Disorder and chaos are ubiquitous phenomena that are mostly unwanted in applications. On the contrary, they can be exploited to create a new technology. In this talk I will summarize my research in this field, discussing chaotic energy harvesting, nonlinear stochastic resonance and complex nanolasers.

  5. Unifying Complexity and Information

    Science.gov (United States)

    Ke, Da-Guan

    2013-04-01

    Complex systems, arising in many contexts in the computer, life, social, and physical sciences, have not shared a generally-accepted complexity measure playing a fundamental role as the Shannon entropy H in statistical mechanics. Superficially-conflicting criteria of complexity measurement, i.e. complexity-randomness (C-R) relations, have given rise to a special measure intrinsically adaptable to more than one criterion. However, deep causes of the conflict and the adaptability are not much clear. Here I trace the root of each representative or adaptable measure to its particular universal data-generating or -regenerating model (UDGM or UDRM). A representative measure for deterministic dynamical systems is found as a counterpart of the H for random process, clearly redefining the boundary of different criteria. And a specific UDRM achieving the intrinsic adaptability enables a general information measure that ultimately solves all major disputes. This work encourages a single framework coving deterministic systems, statistical mechanics and real-world living organisms.

  6. (II) COMPLEX COMPOUND

    African Journals Online (AJOL)

    user

    electrochemical sensors, as well as in various chromatographic ... were carried out using Jenway pH meter Model 3320 and a conductivity ... Figure 1: the proposed molecular structure of the copper (II) Schiff base complex. M = Cu (II) or Mn (II).

  7. Complexity driven photonics

    KAUST Repository

    Fratalocchi, Andrea

    2014-12-01

    Disorder and chaos are ubiquitous phenomena that are mostly unwanted in applications. On the contrary, they can be exploited to create a new technology. In this talk I will summarize my research in this field, discussing chaotic energy harvesting, nonlinear stochastic resonance and complex nanolasers.

  8. The Colletotrichum acutatum complex

    NARCIS (Netherlands)

    Damm, U.; Cannon, P.F.; Woudenberg, J.H.C.; Crous, P.W.

    2012-01-01

    Colletotrichum acutatum is known as an important anthracnose pathogen of a wide range of host plants worldwide. Numerous studies have reported subgroups within the C. acutatum species complex. Multilocus molecular phylogenetic analysis (ITS, ACT, TUB2, CHS-1, GAPDH, HIS3) of 331 strains previously

  9. Architecture of Intermodal Complex

    NARCIS (Netherlands)

    Lee, S.; Herneoja, Aulikki; Österlund, Toni; Markkanen, Piia

    This paper focuses on the conception and design of architecture as the work of producing media about buildings and other environmental artifacts. I approach
    the questions regarding simplicity and complexity through "interdependence" and "intermodality." I believe the two concepts offer more

  10. unsymmetrical Schiff base complexes

    Indian Academy of Sciences (India)

    the effect of the substitutional groups of the Schiff base on the oxidation and reduction potentials, we used ... Electrochemistry of these complexes showed that the presence of electron .... a solution of the ligand (1 mmol) in methanol (15 mL).

  11. Management of complex fisheries

    DEFF Research Database (Denmark)

    Frost, Hans Staby; Andersen, Peder; Hoff, Ayoe

    2013-01-01

    , including taking into account the response of the fishermen to implemented management measures. To demonstrate the use of complex management models this paper assesses a number of second best management schemes against a first rank optimum (FRO), an ideal individual transferable quotas (ITQ) system...

  12. Herding Complex Networks

    KAUST Repository

    Ruf, Sebastian F.; Egersted, Magnus; Shamma, Jeff S.

    2018-01-01

    the ability to drive a system to a specific set in the state space, was recently introduced as an alternative network control notion. This paper considers the application of herdability to the study of complex networks. The herdability of a class of networked

  13. The hamstring muscle complex

    NARCIS (Netherlands)

    van der Made, A. D.; Wieldraaijer, T.; Kerkhoffs, G. M.; Kleipool, R. P.; Engebretsen, L.; van Dijk, C. N.; Golanó, P.

    2015-01-01

    The anatomical appearance of the hamstring muscle complex was studied to provide hypotheses for the hamstring injury pattern and to provide reference values of origin dimensions, muscle length, tendon length, musculotendinous junction (MTJ) length as well as width and length of a tendinous

  14. Symmetry in Complex Networks

    Directory of Open Access Journals (Sweden)

    Angel Garrido

    2011-01-01

    Full Text Available In this paper, we analyze a few interrelated concepts about graphs, such as their degree, entropy, or their symmetry/asymmetry levels. These concepts prove useful in the study of different types of Systems, and particularly, in the analysis of Complex Networks. A System can be defined as any set of components functioning together as a whole. A systemic point of view allows us to isolate a part of the world, and so, we can focus on those aspects that interact more closely than others. Network Science analyzes the interconnections among diverse networks from different domains: physics, engineering, biology, semantics, and so on. Current developments in the quantitative analysis of Complex Networks, based on graph theory, have been rapidly translated to studies of brain network organization. The brain's systems have complex network features—such as the small-world topology, highly connected hubs and modularity. These networks are not random. The topology of many different networks shows striking similarities, such as the scale-free structure, with the degree distribution following a Power Law. How can very different systems have the same underlying topological features? Modeling and characterizing these networks, looking for their governing laws, are the current lines of research. So, we will dedicate this Special Issue paper to show measures of symmetry in Complex Networks, and highlight their close relation with measures of information and entropy.

  15. Light in complex dielectrics

    NARCIS (Netherlands)

    Schuurmans, F.J.P.

    1999-01-01

    In this thesis the properties of light in complex dielectrics are described, with the two general topics of "modification of spontaneous emission" and "Anderson localization of light". The first part focuses on the spontaneous emission rate of an excited atom in a dielectric host with variable

  16. Typical Complexity Numbers

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Typical Complexity Numbers. Say. 1000 tones,; 100 Users,; Transmission every 10 msec. Full Crosstalk cancellation would require. Full cancellation requires a matrix multiplication of order 100*100 for all the tones. 1000*100*100*100 operations every second for the ...

  17. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 4. Life : Complexity and Diversity Growing Larger. Madhav Gadgil. Series Article Volume 1 Issue 4 April 1996 pp 15-22. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/04/0015-0022 ...

  18. The CERN accelerator complex

    CERN Multimedia

    Haffner, Julie

    2013-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  19. Complexity measures of music

    Science.gov (United States)

    Pease, April; Mahmoodi, Korosh; West, Bruce J.

    2018-03-01

    We present a technique to search for the presence of crucial events in music, based on the analysis of the music volume. Earlier work on this issue was based on the assumption that crucial events correspond to the change of music notes, with the interesting result that the complexity index of the crucial events is mu ~ 2, which is the same inverse power-law index of the dynamics of the brain. The search technique analyzes music volume and confirms the results of the earlier work, thereby contributing to the explanation as to why the brain is sensitive to music, through the phenomenon of complexity matching. Complexity matching has recently been interpreted as the transfer of multifractality from one complex network to another. For this reason we also examine the mulifractality of music, with the observation that the multifractal spectrum of a computer performance is significantly narrower than the multifractal spectrum of a human performance of the same musical score. We conjecture that although crucial events are demonstrably important for information transmission, they alone are not suficient to define musicality, which is more adequately measured by the multifractality spectrum.

  20. Complexes Tickling the $ubject

    Directory of Open Access Journals (Sweden)

    Matthew Gildersleeve

    2016-11-01

    Full Text Available This article continues my earlier work of reading Jung with Lacan. This article will develop Zizek’s work on Lacan’s concept of objet petit a by relating it to a phenomenological interpretation of Jung. I use a number of different examples, including Zizek’s interpretation of Francis Bacon, Edvard Munch, Hans Holbein and Johann Gottlieb Fichte, to describe the objet petit a and its relationship to a phenomenological interpretation of complexes. By integrating other Lacanian concepts, such as subject, drive, fantasy, jouissance, gaze, desire, and ego as well as the imaginary, symbolic and Real, this work also highlights how Hegel and Heidegger can elucidate the relationship between objet petit a and complexes. Jung’s transcendent function and the Rosarium Philosophorum also elucidate the relationship between Jung and Lacan.

  1. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...

  2. THO/TREX complex

    KAUST Repository

    Dö ll, Stefanie; Kuhlmann, Markus; Rutten, Twan; Mette, Michael F.; Scharfenberg, Sarah; Petridis, Antonios; Berreth, Dorothee-Carina; Mock, Hans-Peter

    2017-01-01

    Secondary metabolites are involved in the plant stress response. Among these are scopolin and its active form scopoletin, which are coumarin derivatives associated with reactive oxygen species scavenging and pathogen defence. Here we show that scopolin accumulation can be induced in the root by osmotic stress and in the leaf by low-temperature stress in Arabidopsis thaliana. A genetic screen for altered scopolin levels in A. thaliana revealed a mutant compromised in scopolin accumulation in response to stress; the lesion was present in a homologue of THO1 coding for a subunit of the THO/TREX complex. The THO/TREX complex contributes to RNA silencing, supposedly by trafficking precursors of small RNAs. Mutants defective in THO, AGO1, SDS3 and RDR6 were impaired with respect to scopolin accumulation in response to stress, suggesting a mechanism based on RNA silencing such as the trans-acting small interfering RNA pathway, which requires THO/TREX function.

  3. Complexity is simple!

    Science.gov (United States)

    Cottrell, William; Montero, Miguel

    2018-02-01

    In this note we investigate the role of Lloyd's computational bound in holographic complexity. Our goal is to translate the assumptions behind Lloyd's proof into the bulk language. In particular, we discuss the distinction between orthogonalizing and `simple' gates and argue that these notions are useful for diagnosing holographic complexity. We show that large black holes constructed from series circuits necessarily employ simple gates, and thus do not satisfy Lloyd's assumptions. We also estimate the degree of parallel processing required in this case for elementary gates to orthogonalize. Finally, we show that for small black holes at fixed chemical potential, the orthogonalization condition is satisfied near the phase transition, supporting a possible argument for the Weak Gravity Conjecture first advocated in [1].

  4. The medial patellofemoral complex.

    Science.gov (United States)

    Loeb, Alexander E; Tanaka, Miho J

    2018-06-01

    The purpose of this review is to describe the current understanding of the medial patellofemoral complex, including recent anatomic advances, evaluation of indications for reconstruction with concomitant pathology, and surgical reconstruction techniques. Recent advances in our understanding of MPFC anatomy have found that there are fibers that insert onto the deep quadriceps tendon as well as the patella, thus earning the name "medial patellofemoral complex" to allow for the variability in its anatomy. In MPFC reconstruction, anatomic origin and insertion points and appropriate graft length are critical to prevent overconstraint of the patellofemoral joint. The MPFC is a crucial soft tissue checkrein to lateral patellar translation, and its repair or reconstruction results in good restoration of patellofemoral stability. As our understanding of MPFC anatomy evolves, further studies are needed to apply its relevance in kinematics and surgical applications to its role in maintaining patellar stability.

  5. Polystochastic Models for Complexity

    CERN Document Server

    Iordache, Octavian

    2010-01-01

    This book is devoted to complexity understanding and management, considered as the main source of efficiency and prosperity for the next decades. Divided into six chapters, the book begins with a presentation of basic concepts as complexity, emergence and closure. The second chapter looks to methods and introduces polystochastic models, the wave equation, possibilities and entropy. The third chapter focusing on physical and chemical systems analyzes flow-sheet synthesis, cyclic operations of separation, drug delivery systems and entropy production. Biomimetic systems represent the main objective of the fourth chapter. Case studies refer to bio-inspired calculation methods, to the role of artificial genetic codes, neural networks and neural codes for evolutionary calculus and for evolvable circuits as biomimetic devices. The fifth chapter, taking its inspiration from systems sciences and cognitive sciences looks to engineering design, case base reasoning methods, failure analysis, and multi-agent manufacturing...

  6. Rhodium thioacetate complexes

    International Nuclear Information System (INIS)

    Baranovskij, I.B.; Golubnichaya, M.A.; Mazo, G.Ya.

    1976-01-01

    Thioacetato-complexes of rhodium(II) were prepared by the reaction of thioacetic acid with rhodium(II) carboxylates. Diamagnetic compounds of the type Rh 2 (CH 3 COS) 4 2A, where A=H 2 O, Py, N 2 H 4 .HCl, Thio, KNCS, DMSO, CH 3 CN, CsCl, or CH 3 COSH, were isolated. Their infrared spectra were recorded, and the principal vibrational wavenumbers assigned. The X-ray electron spectra confirm that rhodium is divalent. The thioacetato-complexes are dimeric, with a metal-metal bond. [Rh(NH 3 ) 5 (CH 3 COS)]I 2 was prepared, and its properties studied. The significant decrease in the strength of the bonds formed by the axial ligands with rhodium is due to the strong trans-influence of the covalent rhodium-rhodium sigma-bond

  7. Complex conductivity of soils

    DEFF Research Database (Denmark)

    Revil, A.; Coperey, A.; Shao, Z.

    2017-01-01

    The complex conductivity of soil remains poorly known despite the growing importance of this method in hyrogeophysics. In order to fill this gap of knowledge, we investigate the complex conductivity of 71 soils samples (including 4 peat samples) and one clean sand in the frequency range 0.1 Hertz...... to 45 kHz. The soil samples are saturated with 6 different NaCl brines with conductivities (0.031, 0.53, 1.15, 5.7, 14.7, and 22 S m-1, NaCl, 25°C) in order to determine their intrinsic formation factor and surface conductivity. This dataset is used to test the predictions of the dynamic Stern...

  8. Modeling Complex Systems

    International Nuclear Information System (INIS)

    Schreckenberg, M

    2004-01-01

    This book by Nino Boccara presents a compilation of model systems commonly termed as 'complex'. It starts with a definition of the systems under consideration and how to build up a model to describe the complex dynamics. The subsequent chapters are devoted to various categories of mean-field type models (differential and recurrence equations, chaos) and of agent-based models (cellular automata, networks and power-law distributions). Each chapter is supplemented by a number of exercises and their solutions. The table of contents looks a little arbitrary but the author took the most prominent model systems investigated over the years (and up until now there has been no unified theory covering the various aspects of complex dynamics). The model systems are explained by looking at a number of applications in various fields. The book is written as a textbook for interested students as well as serving as a comprehensive reference for experts. It is an ideal source for topics to be presented in a lecture on dynamics of complex systems. This is the first book on this 'wide' topic and I have long awaited such a book (in fact I planned to write it myself but this is much better than I could ever have written it!). Only section 6 on cellular automata is a little too limited to the author's point of view and one would have expected more about the famous Domany-Kinzel model (and more accurate citation!). In my opinion this is one of the best textbooks published during the last decade and even experts can learn a lot from it. Hopefully there will be an actualization after, say, five years since this field is growing so quickly. The price is too high for students but this, unfortunately, is the normal case today. Nevertheless I think it will be a great success! (book review)

  9. On convex complexity measures

    Czech Academy of Sciences Publication Activity Database

    Hrubeš, P.; Jukna, S.; Kulikov, A.; Pudlák, Pavel

    2010-01-01

    Roč. 411, 16-18 (2010), s. 1842-1854 ISSN 0304-3975 R&D Projects: GA AV ČR IAA1019401 Institutional research plan: CEZ:AV0Z10190503 Keywords : boolean formula * complexity measure * combinatorial rectangle * convexity Subject RIV: BA - General Mathematics Impact factor: 0.838, year: 2010 http://www.sciencedirect.com/science/article/pii/S0304397510000885

  10. Complexity in Dynamical Systems

    Science.gov (United States)

    Moore, Cristopher David

    The study of chaos has shown us that deterministic systems can have a kind of unpredictability, based on a limited knowledge of their initial conditions; after a finite time, the motion appears essentially random. This observation has inspired a general interest in the subject of unpredictability, and more generally, complexity; how can we characterize how "complex" a dynamical system is?. In this thesis, we attempt to answer this question with a paradigm of complexity that comes from computer science, we extract sets of symbol sequences, or languages, from a dynamical system using standard methods of symbolic dynamics; we then ask what kinds of grammars or automata are needed a generate these languages. This places them in the Chomsky heirarchy, which in turn tells us something about how subtle and complex the dynamical system's behavior is. This gives us insight into the question of unpredictability, since these automata can also be thought of as computers attempting to predict the system. In the culmination of the thesis, we find a class of smooth, two-dimensional maps which are equivalent to the highest class in the Chomsky heirarchy, the turning machine; they are capable of universal computation. Therefore, these systems possess a kind of unpredictability qualitatively different from the usual "chaos": even if the initial conditions are known exactly, questions about the system's long-term dynamics are undecidable. No algorithm exists to answer them. Although this kind of unpredictability has been discussed in the context of distributed, many-degree-of -freedom systems (for instance, cellular automata) we believe this is the first example of such phenomena in a smooth, finite-degree-of-freedom system.

  11. Complex Business Negotiation

    OpenAIRE

    Lindholst, Morten

    2015-01-01

    Most scholars agree that engaging in preparation and planning is key to a negotiation’s effectiveness but research has largely focused solely on what happens at the negotiation table, rather than in preparation for it. This thesis addresses the balance by clarifying which preparation and planning activities are undertaken to conduct a complex business negotiation. It examines not only what activities are conducted, but also by whom, and when. One important question for both pra...

  12. Volatile uranyl hexafluoroacetoacetonate complexes

    International Nuclear Information System (INIS)

    Dines, M.B.; Hall, R.B.; Kaldor, A.; Kramer, G.M.; Maas, E.T. Jr.

    1980-01-01

    A composition of matter is described, characterized by the formula UO 2 (CF 3 COCHCOCF 3 ).L where L is a ligand selected from isopropanol, ethanol, isobutanol, tert-butanol, methanol, tetrahydrofuran, acetone, dimethylformamide, n-propanol and ethyl acetate. A process for producing the complex comprises reacting uranyl chloride with a hexafluoroacetylacetonate dissolved in a ligand L: experimental details are given. (U.K.)

  13. Operational Shock Complexity Theory

    Science.gov (United States)

    2005-05-26

    Theory : Recommendations For The National Strategy To Defeat Terrorism.” Student Issue Paper, Center for Strategic Leadership , US Army War College, July...Lens of Complexity Theory : Recommendations For The National Strategy To Defeat Terrorism.” (Student Issue Paper, Center for Strategic Leadership , US...planners managed to cause confusion in the enemy’s internal model by operating in an unexpected manner. 140 Glenn E. James, “Chaos Theory : The

  14. Engineering Complex Tissues

    Science.gov (United States)

    MIKOS, ANTONIOS G.; HERRING, SUSAN W.; OCHAREON, PANNEE; ELISSEEFF, JENNIFER; LU, HELEN H.; KANDEL, RITA; SCHOEN, FREDERICK J.; TONER, MEHMET; MOONEY, DAVID; ATALA, ANTHONY; VAN DYKE, MARK E.; KAPLAN, DAVID; VUNJAK-NOVAKOVIC, GORDANA

    2010-01-01

    This article summarizes the views expressed at the third session of the workshop “Tissue Engineering—The Next Generation,” which was devoted to the engineering of complex tissue structures. Antonios Mikos described the engineering of complex oral and craniofacial tissues as a “guided interplay” between biomaterial scaffolds, growth factors, and local cell populations toward the restoration of the original architecture and function of complex tissues. Susan Herring, reviewing osteogenesis and vasculogenesis, explained that the vascular arrangement precedes and dictates the architecture of the new bone, and proposed that engineering of osseous tissues might benefit from preconstruction of an appropriate vasculature. Jennifer Elisseeff explored the formation of complex tissue structures based on the example of stratified cartilage engineered using stem cells and hydrogels. Helen Lu discussed engineering of tissue interfaces, a problem critical for biological fixation of tendons and ligaments, and the development of a new generation of fixation devices. Rita Kandel discussed the challenges related to the re-creation of the cartilage-bone interface, in the context of tissue engineered joint repair. Frederick Schoen emphasized, in the context of heart valve engineering, the need for including the requirements derived from “adult biology” of tissue remodeling and establishing reliable early predictors of success or failure of tissue engineered implants. Mehmet Toner presented a review of biopreservation techniques and stressed that a new breakthrough in this field may be necessary to meet all the needs of tissue engineering. David Mooney described systems providing temporal and spatial regulation of growth factor availability, which may find utility in virtually all tissue engineering and regeneration applications, including directed in vitro and in vivo vascularization of tissues. Anthony Atala offered a clinician’s perspective for functional tissue

  15. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  16. Fluorido complexes of technetium

    International Nuclear Information System (INIS)

    Mariappan Balasekaran, Samundeeswari

    2013-01-01

    Fluorine chemistry has received considerable interest during recent years due to its significant role in the life sciences, especially for drug development. Despite the great nuclear medicinal importance of the radioactive metal technetium in radiopharmaceuticals, its coordination chemistry with the fluorido ligand is by far less explored than that of other ligands. Up to now, only a few technetium fluorides are known. This thesis contains the synthesis, spectroscopic and structural characterization of novel technetium fluorides in the oxidation states ''+1'', ''+2'', ''+4'' and ''+6''. In the oxidation state ''+6'', the fluoridotechnetates were synthesized either from nitridotechnetic(VI) acid or from pertechnetate by using reducing agent and have been isolated as cesium or tetraethylammonium salts. The compounds were characterized spectroscopically and structurally. In the intermediate oxidation state ''+4'', hexafluoridotechnetate(IV) was known for long time and studied spectroscopically. This thesis reports novel and improved syntheses and solved the critical issues of early publications such as the color, some spectroscopic properties and the structure of this key compound. Single crystal analyses of alkali metal, ammonium and tetramethylammonium salts of hexafluoridotechnetate(IV) are presented. In aqueous alkaline solutions, the ammonium salt of hexafluoridotechnetate(IV) undergoes hydrolysis and forms an oxido-bridged dimeric complex. It is the first step hydrolysis product of hexafluoridotechnetate(IV) and was characterized by spectroscopic and crystallographic methods. Low-valent technetium fluorides with the metal in the oxidation states of ''+2'' or ''+1'' are almost unknown. A detailed description of the synthesis and characterization of pentafluoridonitrosyltechnetate(II) is presented. The complex was isolated as alkali metal salts, and spectroscopic as well as structural features of the complexes are presented. Different salts of the trans

  17. Arithmetic of Complex Manifolds

    CERN Document Server

    Lange, Herbert

    1989-01-01

    It was the aim of the Erlangen meeting in May 1988 to bring together number theoretists and algebraic geometers to discuss problems of common interest, such as moduli problems, complex tori, integral points, rationality questions, automorphic forms. In recent years such problems, which are simultaneously of arithmetic and geometric interest, have become increasingly important. This proceedings volume contains 12 original research papers. Its main topics are theta functions, modular forms, abelian varieties and algebraic three-folds.

  18. Complex concentrate pretreatment

    International Nuclear Information System (INIS)

    Lokken, R.O.; Scheele, R.D.; Strachan, D.M.; Toste, A.P.

    1991-03-01

    After removal of the transuranics (TRU) by the TRUEX process, complex concentrate waste will be grouted for final storage. The purpose of this project, conducted at the Pacific Northwest Laboratory, is to support a future decision to grout the complexant waste without destruction of the organic contents. It has been demonstrated that grouts with acceptable parameters for the Transportable Grout Facility can be made using actual waste. The acceptability of these grouts from a regulatory view seems to be less of a problem than previously. None of the organics found in the waste have been found on the EPA hazardous chemicals list. Two potential problems with the processing of the complex concentrate wastes were identified during the use of the TRUEX process on samples of several milliliters. One was the amount of foam that is generated during acid addition to the alkaline waste. Some of this foam appears to be of a waxy nature but does redissolve when the waste is strongly acid. The second potential problem is that noticeable amounts of NO x gases are generated. No quantitative measure of the NO x gas generation was made. The problem relates to processing the waste in B-plant where there are no facilities to handle NO x gases. 5 refs., 4 figs., 4 tabs

  19. Predictive Surface Complexation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, Dimitri A. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Earth and Planetary Sciences

    2016-11-29

    Surface complexation plays an important role in the equilibria and kinetics of processes controlling the compositions of soilwaters and groundwaters, the fate of contaminants in groundwaters, and the subsurface storage of CO2 and nuclear waste. Over the last several decades, many dozens of individual experimental studies have addressed aspects of surface complexation that have contributed to an increased understanding of its role in natural systems. However, there has been no previous attempt to develop a model of surface complexation that can be used to link all the experimental studies in order to place them on a predictive basis. Overall, my research has successfully integrated the results of the work of many experimentalists published over several decades. For the first time in studies of the geochemistry of the mineral-water interface, a practical predictive capability for modeling has become available. The predictive correlations developed in my research now enable extrapolations of experimental studies to provide estimates of surface chemistry for systems not yet studied experimentally and for natural and anthropogenically perturbed systems.

  20. Control of complex systems

    CERN Document Server

    Albertos, Pedro; Blanke, Mogens; Isidori, Alberto; Schaufelberger, Walter; Sanz, Ricardo

    2001-01-01

    The world of artificial systems is reaching complexity levels that es­ cape human understanding. Surface traffic, electricity distribution, air­ planes, mobile communications, etc. , are examples that demonstrate that we are running into problems that are beyond classical scientific or engi­ neering knowledge. There is an ongoing world-wide effort to understand these systems and develop models that can capture its behavior. The reason for this work is clear, if our lack of understanding deepens, we will lose our capability to control these systems and make they behave as we want. Researchers from many different fields are trying to understand and develop theories for complex man-made systems. This book presents re­ search from the perspective of control and systems theory. The book has grown out of activities in the research program Control of Complex Systems (COSY). The program has been sponsored by the Eu­ ropean Science Foundation (ESF) which for 25 years has been one of the leading players in stimula...

  1. [VGKC-complex antibodies].

    Science.gov (United States)

    Watanabe, Osamu

    2013-04-01

    Various antibodies are associated with voltage-gated potassium channels (VGKCs). Representative antibodies to VGKCs were first identified by radioimmunoassays using radioisotope-labeled alpha-dendrotoxin-VGKCs solubilized from rabbit brain. These antibodies were detected only in a proportion of patients with acquired neuromyotonia (Isaacs' syndrome). VGKC antibodies were also detected in patients with Morvan's syndrome and in those with a form of autoimmune limbic encephalitis. Recent studies indicated that the "VGKC" antibodies are mainly directed toward associated proteins (for example LGI-1 and CASPR-2) that complex with the VGKCs themselves. The "VGKC" antibodies are now commonly known as VGKC-complex antibodies. In general, LGI-1 antibodies are most commonly detected in patients with limbic encephalitis with syndrome of inappropriate secretion of antidiuretic hormone. CASPR-2 antibodies are present in the majority of patients with Morvan's syndrome. These patients develop combinations of CNS symptoms, autonomic dysfunction, and peripheral nerve hyperexcitability. Furthermore, VGKC-complex antibodies are tightly associated with chronic idiopathic pain. Hyperexcitability of nociceptive pathways has also been implicated. These antibodies may be detected in sera of some patients with neurodegenerative diseases (for example, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease).

  2. [Complex posttraumatic stress disorder].

    Science.gov (United States)

    Green, Tamar; Kotler, Moshe

    2007-11-01

    The characteristic symptoms resulting from exposure to an extreme trauma include three clusters of symptoms: persistent experience of the traumatic event, persistent avoidance of stimuli associated with the trauma and persistent symptoms of increased arousal. Beyond the accepted clusters of symptoms for posttraumatic stress disorder exists a formation of symptoms related to exposure to extreme or prolonged stress e.g. childhood abuse, physical violence, rape, and confinement within a concentration camp. With accumulated evidence of the existence of these symptoms began a trail to classify a more complex syndrome, which included, but was not confined to the symptoms of posttraumatic stress disorder. This review addresses several subjects for study in complex posttraumatic stress disorder, which is a complicated and controversial topic. Firstly, the concept of complex posttraumatic stress disorder is presented. Secondly, the professional literature relevant to this disturbance is reviewed and finally, the authors present the polemic being conducted between the researchers of posttraumatic disturbances regarding validity, reliability and the need for separate diagnosis for these symptoms.

  3. Complexity Leadership: A Theoretical Perspective

    Science.gov (United States)

    Baltaci, Ali; Balci, Ali

    2017-01-01

    Complex systems are social networks composed of interactive employees interconnected through collaborative, dynamic ties such as shared goals, perspectives and needs. Complex systems are largely based on "the complex system theory". The complex system theory focuses mainly on finding out and developing strategies and behaviours that…

  4. Complex Neutrosophic Subsemigroups and Ideals

    Directory of Open Access Journals (Sweden)

    Muhammad Gulistan

    2018-01-01

    Full Text Available In this article we study the idea of complex neutrosophic subsemigroups. We define the Cartesian product of complex neutrosophic subsemigroups, give some examples and study some of its related results. We also define complex neutrosophic (left, right, interior ideal in semigroup. Furthermore, we introduce the concept of characteristic function of complex neutrosophic sets, direct product of complex neutrosophic sets and study some results prove on its.

  5. Transition Complexity of Incomplete DFAs

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2010-08-01

    Full Text Available In this paper, we consider the transition complexity of regular languages based on the incomplete deterministic finite automata. A number of results on Boolean operations have been obtained. It is shown that the transition complexity results for union and complementation are very different from the state complexity results for the same operations. However, for intersection, the transition complexity result is similar to that of state complexity.

  6. The Stigma Complex

    Science.gov (United States)

    Pescosolido, Bernice A.; Martin, Jack K.

    2016-01-01

    Since the beginning of the twenty-first century, research on stigma has continued. Building on conceptual and empirical work, the recent period clarifies new types of stigmas, expansion of measures, identification of new directions, and increasingly complex levels. Standard beliefs have been challenged, the relationship between stigma research and public debates reconsidered, and new scientific foundations for policy and programs suggested. We begin with a summary of the most recent Annual Review articles on stigma, which reminded sociologists of conceptual tools, informed them of developments from academic neighbors, and claimed findings from the early period of “resurgence.” Continued (even accelerated) progress has also revealed a central problem. Terms and measures are often used interchangeably, leading to confusion and decreasing accumulated knowledge. Drawing from this work but focusing on the past 14 years of stigma research (including mental illness, sexual orientation, HIV/AIDS, and race/ethnicity), we provide a theoretical architecture of concepts (e.g., prejudice, experienced/received discrimination), drawn together through a stigma process (i.e., stigmatization), based on four theoretical premises. Many characteristics of the mark (e.g., discredited, concealable) and variants (i.e., stigma types and targets) become the focus of increasingly specific and multidimensional definitions. Drawing from complex and systems science, we propose a stigma complex, a system of interrelated, heterogeneous parts bringing together insights across disciplines to provide a more realistic and complicated sense of the challenge facing research and change efforts. The Framework Integrating Normative Influences on Stigma (FINIS) offers a multilevel approach that can be tailored to stigmatized statuses. Finally, we outline challenges for the next phase of stigma research, with the goal of continuing scientific activity that enhances our understanding of stigma and builds

  7. Organization of complex networks

    Science.gov (United States)

    Kitsak, Maksim

    Many large complex systems can be successfully analyzed using the language of graphs and networks. Interactions between the objects in a network are treated as links connecting nodes. This approach to understanding the structure of networks is an important step toward understanding the way corresponding complex systems function. Using the tools of statistical physics, we analyze the structure of networks as they are found in complex systems such as the Internet, the World Wide Web, and numerous industrial and social networks. In the first chapter we apply the concept of self-similarity to the study of transport properties in complex networks. Self-similar or fractal networks, unlike non-fractal networks, exhibit similarity on a range of scales. We find that these fractal networks have transport properties that differ from those of non-fractal networks. In non-fractal networks, transport flows primarily through the hubs. In fractal networks, the self-similar structure requires any transport to also flow through nodes that have only a few connections. We also study, in models and in real networks, the crossover from fractal to non-fractal networks that occurs when a small number of random interactions are added by means of scaling techniques. In the second chapter we use k-core techniques to study dynamic processes in networks. The k-core of a network is the network's largest component that, within itself, exhibits all nodes with at least k connections. We use this k-core analysis to estimate the relative leadership positions of firms in the Life Science (LS) and Information and Communication Technology (ICT) sectors of industry. We study the differences in the k-core structure between the LS and the ICT sectors. We find that the lead segment (highest k-core) of the LS sector, unlike that of the ICT sector, is remarkably stable over time: once a particular firm enters the lead segment, it is likely to remain there for many years. In the third chapter we study how

  8. Magnox waste storage complex

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This article looks at the design and construction of British Nuclear Fuel Limited's (BNFL) Magnox waste storage complex by Costain Engineering Limited. Magnox swarf from fuel decanning is stored underwater in specially designed silos. Gas processing capabilities from Costain Engineering Limited and the experience of BNFL combined in this project to provide the necessary problem-solving skills necessary for this waste storage upgrading and extension project. A retrofitted inerting facility was fitted to an existing building and a new storage extension was fitted, both without interrupting reprocessing operations at Sellafield. (UK)

  9. Computability, complexity, logic

    CERN Document Server

    Börger, Egon

    1989-01-01

    The theme of this book is formed by a pair of concepts: the concept of formal language as carrier of the precise expression of meaning, facts and problems, and the concept of algorithm or calculus, i.e. a formally operating procedure for the solution of precisely described questions and problems. The book is a unified introduction to the modern theory of these concepts, to the way in which they developed first in mathematical logic and computability theory and later in automata theory, and to the theory of formal languages and complexity theory. Apart from considering the fundamental themes an

  10. Complex adaptive systems ecology

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2003-01-01

    In the following, I will analyze two articles called Complex Adaptive Systems EcologyI & II (Molin & Molin, 1997 & 2000). The CASE-articles are some of the more quirkyarticles that have come out of the Molecular Microbial Ecology Group - a groupwhere I am currently making observational studies....... They are the result of acooperation between Søren Molin, professor in the group, and his brother, JanMolin, professor at Department of Organization and Industrial Sociology atCopenhagen Business School. The cooperation arises from the recognition that bothmicrobial ecology and sociology/organization theory works...

  11. Complexity in Managing Modularization

    DEFF Research Database (Denmark)

    Hansen, Poul H. Kyvsgård; Sun, Hongyi

    2011-01-01

    In general, the phenomenon of managing modularization is not well known. The cause-effect relationships between modularization and realized benefits are complex and comprehensive. Though a number of research works have contributed to the study of the phenomenon of efficient and effective...... modularization management it is far from clarified. Recognizing the need for further empirical research, we have studied 40 modularity cases in various companies. The studies have been designed as long-term studies leaving time for various types of modularization benefits to emerge. Based on these studies we...... have developed a framework to support the heuristic and iterative process of planning and realizing modularization benefits....

  12. Procuring complex performance

    DEFF Research Database (Denmark)

    Hartmann, A.; Roehrich, J.; Frederiksen, Lars

    2014-01-01

    the transition process. Design/methodology/approach – A multiple, longitudinal case study method is used to examine the transition towards PCP. The study deploys rich qualitative data sets by combining semi-structured interviews, focus group meetings and organisational reports and documents. Findings...... and relational challenges they need to master when facing higher levels of performance and infrastructural complexity. Originality/value – The study adds to the limited empirical and conceptual understanding on the nature of long-term public-private interactions in PCP. It contributes through a rare focus...

  13. Complex photonic structures

    International Nuclear Information System (INIS)

    Wiersma, D.S.

    2013-01-01

    We discuss in detail the optical properties of complex photonic structures, in particular those with a dominating disorder component. We will focus on their general transport properties, as well as on their use as light sources (random lasers). The basis for the theory of multiple light scattering in random systems will be explained as a tutorial introduction to the topic, including the explicit calculation of the effect of coherent backscattering. We will discuss various structures that go beyond regular disordered ones, in particular Levy glasses, liquid crystals, and quasicrystals, and show examples of their optical properties both from a conceptual and practical point of view.

  14. Fluorido complexes of technetium

    Energy Technology Data Exchange (ETDEWEB)

    Mariappan Balasekaran, Samundeeswari

    2013-07-04

    Fluorine chemistry has received considerable interest during recent years due to its significant role in the life sciences, especially for drug development. Despite the great nuclear medicinal importance of the radioactive metal technetium in radiopharmaceuticals, its coordination chemistry with the fluorido ligand is by far less explored than that of other ligands. Up to now, only a few technetium fluorides are known. This thesis contains the synthesis, spectroscopic and structural characterization of novel technetium fluorides in the oxidation states ''+1'', ''+2'', ''+4'' and ''+6''. In the oxidation state ''+6'', the fluoridotechnetates were synthesized either from nitridotechnetic(VI) acid or from pertechnetate by using reducing agent and have been isolated as cesium or tetraethylammonium salts. The compounds were characterized spectroscopically and structurally. In the intermediate oxidation state ''+4'', hexafluoridotechnetate(IV) was known for long time and studied spectroscopically. This thesis reports novel and improved syntheses and solved the critical issues of early publications such as the color, some spectroscopic properties and the structure of this key compound. Single crystal analyses of alkali metal, ammonium and tetramethylammonium salts of hexafluoridotechnetate(IV) are presented. In aqueous alkaline solutions, the ammonium salt of hexafluoridotechnetate(IV) undergoes hydrolysis and forms an oxido-bridged dimeric complex. It is the first step hydrolysis product of hexafluoridotechnetate(IV) and was characterized by spectroscopic and crystallographic methods. Low-valent technetium fluorides with the metal in the oxidation states of ''+2'' or ''+1'' are almost unknown. A detailed description of the synthesis and characterization of pentafluoridonitrosyltechnetate(II) is presented. The

  15. Complex Strategic Choices

    DEFF Research Database (Denmark)

    Leleur, Steen

    to strategic decision making, Complex Strategic Choices presents a methodology which is further illustrated by a number of case studies and example applications. Dr. Techn. Steen Leleur has adapted previously established research based on feedback and input from various conferences, journals and students...... resulting in new material stemming from and focusing on practical application of a systemic approach. The outcome is a coherent and flexible approach named systemic planning. The inclusion of both the theoretical and practical aspects of systemic planning makes this book a key resource for researchers...

  16. Dismounted Complex Blast Injury.

    Science.gov (United States)

    Andersen, Romney C; Fleming, Mark; Forsberg, Jonathan A; Gordon, Wade T; Nanos, George P; Charlton, Michael T; Ficke, James R

    2012-01-01

    The severe Dismounted Complex Blast Injury (DCBI) is characterized by high-energy injuries to the bilateral lower extremities (usually proximal transfemoral amputations) and/or upper extremity (usually involving the non-dominant side), in addition to open pelvic injuries, genitourinary, and abdominal trauma. Initial resuscitation and multidisciplinary surgical management appear to be the keys to survival. Definitive treatment follows general principals of open wound management and includes decontamination through aggressive and frequent debridement, hemorrhage control, viable tissue preservation, and appropriate timing of wound closure. These devastating injuries are associated with paradoxically favorable survival rates, but associated injuries and higher amputation levels lead to more difficult reconstructive challenges.

  17. The Frankenstein Complex

    DEFF Research Database (Denmark)

    Jensen, Boris Brorman

    2016-01-01

    In his polemic essay Boris Brorman Jensen raises the issue of a perceived academic reluctance to acknowledge the impact of real-world pragmatics on the architectural expression of built architecture. “One might claim that parts of architectural academia suffer from a Frankenstein complex that seems...... to feed a certain academic fear of dealing with the messiness of the real world. This professional fear that the political, social, technical, economic and legal realities will fundamentally weaken and compromise pure architectural thinking rests on the misperception that architecture is not, essentially...

  18. Complex performance in construction

    DEFF Research Database (Denmark)

    Bougrain, Frédéric; Forman, Marianne; Gottlieb, Stefan Christoffer

    To fulfil the expectations of demanding clients, new project-delivery mechanisms have been developed. Approaches focusing on performance-based building or new procurement processers such as new forms of private-public partnerships are considered as solutions improving the overall performance...... to the end users. This report summarises the results from work undertaken in the international collaborative project “Procuring and Operating Complex Products and Systems in Construction” (POCOPSC). POCOPSC was carried out in the period 2010-2014. The project was executed in collaboration between CSTB...

  19. Herding Complex Networks

    KAUST Repository

    Ruf, Sebastian F.

    2018-04-12

    The problem of controlling complex networks is of interest to disciplines ranging from biology to swarm robotics. However, controllability can be too strict a condition, failing to capture a range of desirable behaviors. Herdability, which describes the ability to drive a system to a specific set in the state space, was recently introduced as an alternative network control notion. This paper considers the application of herdability to the study of complex networks. The herdability of a class of networked systems is investigated and two problems related to ensuring system herdability are explored. The first is the input addition problem, which investigates which nodes in a network should receive inputs to ensure that the system is herdable. The second is a related problem of selecting the best single node from which to herd the network, in the case that a single node is guaranteed to make the system is herdable. In order to select the best herding node, a novel control energy based herdability centrality measure is introduced.

  20. Complexity in language acquisition.

    Science.gov (United States)

    Clark, Alexander; Lappin, Shalom

    2013-01-01

    Learning theory has frequently been applied to language acquisition, but discussion has largely focused on information theoretic problems-in particular on the absence of direct negative evidence. Such arguments typically neglect the probabilistic nature of cognition and learning in general. We argue first that these arguments, and analyses based on them, suffer from a major flaw: they systematically conflate the hypothesis class and the learnable concept class. As a result, they do not allow one to draw significant conclusions about the learner. Second, we claim that the real problem for language learning is the computational complexity of constructing a hypothesis from input data. Studying this problem allows for a more direct approach to the object of study--the language acquisition device-rather than the learnable class of languages, which is epiphenomenal and possibly hard to characterize. The learnability results informed by complexity studies are much more insightful. They strongly suggest that target grammars need to be objective, in the sense that the primitive elements of these grammars are based on objectively definable properties of the language itself. These considerations support the view that language acquisition proceeds primarily through data-driven learning of some form. Copyright © 2013 Cognitive Science Society, Inc.

  1. Dynamics in Complex Coacervates

    Science.gov (United States)

    Perry, Sarah

    Understanding the dynamics of a material provides detailed information about the self-assembly, structure, and intermolecular interactions present in a material. While rheological methods have long been used for the characterization of complex coacervate-based materials, it remains a challenge to predict the dynamics for a new system of materials. Furthermore, most work reports only qualitative trends exist as to how parameters such as charge stoichiometry, ionic strength, and polymer chain length impact self-assembly and material dynamics, and there is little information on the effects of polymer architecture or the organization of charges within a polymer. We seek to link thermodynamic studies of coacervation phase behavior with material dynamics through a carefully-controlled, systematic study of coacervate linear viscoelasticity for different polymer chemistries. We couple various methods of characterizing the dynamics of polymer-based complex coacervates, including the time-salt superposition methods developed first by Spruijt and coworkers to establish a more mechanistic strategy for comparing the material dynamics and linear viscoelasticity of different systems. Acknowledgment is made to the Donors of the American Chemical Society Petroleum Research Fund for support of this research.

  2. River rating complexity

    Science.gov (United States)

    Holmes, Robert R.

    2016-01-01

    Accuracy of streamflow data depends on the veracity of the rating model used to derive a continuous time series of discharge from the surrogate variables that can readily be collected autonomously at a streamgage. Ratings are typically represented as a simple monotonic increasing function (simple rating), meaning the discharge is a function of stage alone, however this is never truly the case unless the flow is completely uniform at all stages and in transitions from one stage to the next. For example, at some streamflow-monitoring sites the discharge on the rising limb of the hydrograph is discernably larger than the discharge at the same stage on the falling limb of the hydrograph. This is the so-called “loop rating curve” (loop rating). In many cases, these loops are quite small and variation between rising- and falling-limb discharge measurements made at the same stage are well within the accuracy of the measurements. However, certain hydraulic conditions can produce a loop that is large enough to preclude use of a monotonic rating. A detailed data campaign for the Mississippi River at St. Louis, Missouri during a multi-peaked flood over a 56-day period in 2015 demonstrates the rating complexity at this location. The shifting-control method used to deal with complexity at this site matched all measurements within 8%.

  3. Shapes of interacting RNA complexes

    DEFF Research Database (Denmark)

    Fu, Benjamin Mingming; Reidys, Christian

    2014-01-01

    Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....

  4. Complex dynamical invariants for two-dimensional complex potentials

    Indian Academy of Sciences (India)

    Abstract. Complex dynamical invariants are searched out for two-dimensional complex poten- tials using rationalization method within the framework of an extended complex phase space characterized by x = x1 + ip3, y = x2 + ip4, px = p1 + ix3, py = p2 + ix4. It is found that the cubic oscillator and shifted harmonic oscillator ...

  5. OF AGROINDUSTRIAL COMPLEX MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Ruslan E. Mansurov

    2017-06-01

    Full Text Available The relevance of this work is determined, on the one hand, by tightening of the foreign political situation and its possible negative impact on the food security of the country, and, on the other hand, by the crisis of the domestic agricultural sector. These factors demand the development of new approaches to regional agroindustrial complex (AIC management. The aim is to develop a methodology for assessing the level of food self-sufficiency in main food areas of the Volgograd region. The author used the results of the statistical materials of AIC of the Volgograd region for 2016. The analytical methods included mathematical analysis and comparison. The main results are as follows. Based on the analysis of the current situation to ensure food security of Russia it was proved that at the present time it is necessary to develop effective indicators showing the level of self-sufficiency in basic food regions. It was also revealed that at the moment this indicator in the system of regional agrarian and industrial complex is not controlled. As a result of generalization of existing approaches the author’s method of rating the level of self-sufficiency of regions was offered. Its testing was carried out in several districts of the Volgograd region. The proposed authoring method of rating estimation of self-sufficiency in basic foodstuffs can be used in the regional agroindustrial complex management system at the federal and local levels. It can be used to rank areas in terms of their self-sufficiency in basic foodstuffs. This allows us to focus on the development of backward areas of agro-food and make appropriate management decisions. The final rating value - 0.759 obtained by the results of analysis of the situation in the Volgograd region means that the situation in matters of selfsufficiency in basic foodstuffs in general is good. However, we should aim at the maximum possible value of the rating - 1. In the application of the proposed

  6. Thermodynamics of complexity

    DEFF Research Database (Denmark)

    Westerhoff, Hans V.; Jensen, Peter Ruhdal; Snoep, Jacky L.

    1998-01-01

    -called emergent properties. Tendency towards increased entropy is an essential determinant for the behaviour of ideal gas mixtures, showing that even in the simplest physical/chemical systems, (dys)organisation of components is crucial for the behaviour of systems. This presentation aims at illustrating...... that the behaviour of two functionally interacting biological components (molecules, protein domains, pathways, organelles) differs from the behaviour these components would exhibit in isolation from one another, where the difference should be essential for the maintenance and growth of the living state, For a true...... understanding of this BioComplexity, modem thermodynamic concepts and methods (nonequilibrium thermodynamics, metabolic and hierarchical control analysis) will be needed. We shall propose to redefine nonequilibrium thermodynamics as: The science that aims at understanding the behaviour of nonequilibrium systems...

  7. Complexity, Metastability and Nonextensivity

    Science.gov (United States)

    Beck, C.; Benedek, G.; Rapisarda, A.; Tsallis, C.

    Work and heat fluctuations in systems with deterministic and stochastic forces / E. G. D. Cohen and R. Van Zon -- Is the entropy S[symbol] extensive or nonextensive? / C. Tsallis -- Superstatistics: recent developments and applications / C. Beck -- Two stories outside Boltzmann-Gibbs statistics: Mori's Q-phase transitions and glassy dynamics at the onset of chaos / A. Robledo, F. Baldovin and E. Mayoral -- Time-averages and the heat theorem / A. Carati -- Fundamental formulae and numerical evidences for the central limit theorem in Tsallis statistics / H. Suyari -- Generalizing the Planck distribution / A. M. C. Soma and C. Tsallis -- The physical roots of complexity: renewal or modulation? / P. Grigolini -- Nonequivalent ensembles and metastability / H. Touchette and R. S. Ellis -- Statistical physics for cosmic structures / L. Pietronero and F. Sylos Labini -- Metastability and anomalous behavior in the HMF model: connections to nonextensive thermodynamics and glassy dynamics / A. Pluchino, A. Rapisarda and V. Latora -- Vlasov analysis of relaxation and meta-equilibrium / C. Anteneodo and R. O. Vallejos -- Weak chaos in large conservative systems - infinite-range coupled standard maps / L. G. Moyano, A. P. Majtey and C. Tsallis -- Deterministc aging / E. Barkai -- Edge of chaos of the classical kicked top map: sensitivity to initial conditions / S. M. Duarte Queirós and C. Tsallis -- What entropy at the edge of chaos? / M. Lissia, M. Coraddu and R. Tonelli -- Fractal growth of carbon schwarzites / G. Benedek ... [et al.] -- Clustering and interface propagation in interacting particle dynamics / A. Provata and V. K. Noussiou -- Resonant activation and noise enhanced stability in Josephson junctions / A. L. Pankratov and B. Spagnolo -- Symmetry breaking induced directed motions / C.-H. Chang and T. Y. Tsong -- General theory of Galilean-invariant entropic lattic Boltzmann models / B. M. Boghosian -- Unifying approach to the jamming transition in granular media and

  8. Complex algebraic geometry

    CERN Document Server

    Kollár, János

    1997-01-01

    This volume contains the lectures presented at the third Regional Geometry Institute at Park City in 1993. The lectures provide an introduction to the subject, complex algebraic geometry, making the book suitable as a text for second- and third-year graduate students. The book deals with topics in algebraic geometry where one can reach the level of current research while starting with the basics. Topics covered include the theory of surfaces from the viewpoint of recent higher-dimensional developments, providing an excellent introduction to more advanced topics such as the minimal model program. Also included is an introduction to Hodge theory and intersection homology based on the simple topological ideas of Lefschetz and an overview of the recent interactions between algebraic geometry and theoretical physics, which involve mirror symmetry and string theory.

  9. Mutagenicity of complex mixtures

    International Nuclear Information System (INIS)

    Pelroy, R.A.

    1985-01-01

    The effect of coal-derived complex chemical mixtures on the mutagenicity of 6-aminochrysene (6-AC) was determined with Salmonella typhimurium TA98. Previous results suggested that the mutagenic potency of 6-AC for TA98 in the standard microsomal activation (Ames) assay increased if it was presented to the cells mixed with high-boiling coal liquids (CL) from the solvent refined coal (SRC) process. In this year's work, the apparent mutational synergism of CL and 6-AC was independently verified in a fluctuation bioassay which allowed quantitation of mutational frequencies and cell viability. The results of this assay system were similar to those in the Ames assay. Moreover, the fluctation assay revealed that mutagenesis and cellular toxicity induced by 6-AC were both strongly enhanced if 6-AC was presented to the cells mixed in a high-boiling CL. 4 figures

  10. Complex Algebraic Varieties

    CERN Document Server

    Peternell, Thomas; Schneider, Michael; Schreyer, Frank-Olaf

    1992-01-01

    The Bayreuth meeting on "Complex Algebraic Varieties" focussed on the classification of algebraic varieties and topics such as vector bundles, Hodge theory and hermitian differential geometry. Most of the articles in this volume are closely related to talks given at the conference: all are original, fully refereed research articles. CONTENTS: A. Beauville: Annulation du H(1) pour les fibres en droites plats.- M. Beltrametti, A.J. Sommese, J.A. Wisniewski: Results on varieties with many lines and their applications to adjunction theory.- G. Bohnhorst, H. Spindler: The stability of certain vector bundles on P(n) .- F. Catanese, F. Tovena: Vector bundles, linear systems and extensions of (1).- O. Debarre: Vers uns stratification de l'espace des modules des varietes abeliennes principalement polarisees.- J.P. Demailly: Singular hermitian metrics on positive line bundles.- T. Fujita: On adjoint bundles of ample vector bundles.- Y. Kawamata: Moderate degenerations of algebraic surfaces.- U. Persson: Genus two fibra...

  11. Invitation to complex analysis

    CERN Document Server

    Boas, Ralph P

    2010-01-01

    Ideal for a first course in complex analysis, this book can be used either as a classroom text or for independent study. Written at a level accessible to advanced undergraduates and beginning graduate students, the book is suitable for readers acquainted with advanced calculus or introductory real analysis. The treatment goes beyond the standard material of power series, Cauchy's theorem, residues, conformal mapping, and harmonic functions by including accessible discussions of intriguing topics that are uncommon in a book at this level. The flexibility afforded by the supplementary topics and applications makes the book adaptable either to a short, one-term course or to a comprehensive, full-year course. Detailed solutions of the exercises both serve as models for students and facilitate independent study. Supplementary exercises, not solved in the book, provide an additional teaching tool. This second edition has been painstakingly revised by the author's son, himself an award-winning mathematical expositor...

  12. Genetics of complex diseases

    DEFF Research Database (Denmark)

    Mellerup, Erling; Møller, Gert Lykke; Koefoed, Pernille

    2012-01-01

    A complex disease with an inheritable component is polygenic, meaning that several different changes in DNA are the genetic basis for the disease. Such a disease may also be genetically heterogeneous, meaning that independent changes in DNA, i.e. various genotypes, can be the genetic basis...... for the disease. Each of these genotypes may be characterized by specific combinations of key genetic changes. It is suggested that even if all key changes are found in genes related to the biology of a certain disease, the number of combinations may be so large that the number of different genotypes may be close...... to the number of patients suffering from the disease. This hypothesis is based on a study of bipolar disorder....

  13. A Cryo Complex Control

    CERN Document Server

    Alferov, V; Fedorchenko, V; Ivanova, N; Kholkin, A; Klimov, S; Krendelev, V; Kuznetsov, S; Lukyantsev, A; Lutchev, A; Milutkin, V; Sytin, A N; Vasilev, D

    2004-01-01

    A Cryogenic complex is being constructed to provide by liquid helium and nitrogen the RF-separator of kaons. About 500 parameters including temperature (1,8…300)K, liquid helium/nitrogen level, vacuum, 300 digital signals have to be measured, 70 commands generated, 20 closed loops activated. The paper describes controls electronics which includes home made I8051 compatible controllers connected by the CAN field bus to a bus controller and interface electronic modules for: - temperature measurements; - liquid Ni and He level measurements; - vacuum pumps current measurements; - analog and digital signals measurements and generations. The modules are tested together with signal imitators within a vertical slice of the Control System based on EPICS tools.

  14. Segmentation of complex document

    Directory of Open Access Journals (Sweden)

    Souad Oudjemia

    2014-06-01

    Full Text Available In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.

  15. Complexity in Evolutionary Processes

    International Nuclear Information System (INIS)

    Schuster, P.

    2010-01-01

    Darwin's principle of evolution by natural selection is readily casted into a mathematical formalism. Molecular biology revealed the mechanism of mutation and provides the basis for a kinetic theory of evolution that models correct reproduction and mutation as parallel chemical reaction channels. A result of the kinetic theory is the existence of a phase transition in evolution occurring at a critical mutation rate, which represents a localization threshold for the population in sequence space. Occurrence and nature of such phase transitions depend critically on fitness landscapes. The fitness landscape being tantamount to a mapping from sequence or genotype space into phenotype space is identified as the true source of complexity in evolution. Modeling evolution as a stochastic process is discussed and neutrality with respect to selection is shown to provide a major challenge for understanding evolutionary processes (author)

  16. Complex Interfaces Under Change

    DEFF Research Database (Denmark)

    Rosbjerg, Dan

    The hydrosphere is dynamic across the major compartments of the Earth system: the atmosphere, the oceans and seas, the land surface water, and the groundwater within the strata below the two last compartments. The global geography of the hydrosphere essentially depends on thermodynamic and mechan...... these interfaces and interfaced compartments and processes. Climate, sea-level, oceanographic currents and hydrological processes are all affected, while anthropogenic changes are often intense in the geographic settings corresponding to such interfaces....... and mechanical processes that develop within this structure. Water-related processes at the interfaces between the compartments are complex, depending both on the interface itself, and on the characteristics of the interfaced compartments. Various aspects of global change directly or indirectly impact...

  17. Iridium complexes for electrocatalysis

    Science.gov (United States)

    Sheehan, Stafford Wheeler; Hintermair, Ulrich; Thomsen, Julianne M; Brudvig, Gary W; Crabtree, Robert H

    2017-10-17

    Solution-phase (e.g., homogeneous) or surface-immobilized (e.g., heterogeneous) electrode-driven oxidation catalysts based on iridium coordination compounds which self-assemble upon chemical or electrochemical oxidation of suitable precursors and methods of making and using thereof are. Iridium species such as {[Ir(LX).sub.x(H.sub.2O).sub.y(.mu.-O)].sub.z.sup.m+}.sub.n wherein x, y, m are integers from 0-4, z and n from 1-4 and LX is an oxidation-resistant chelate ligand or ligands, such as such as 2(2-pyridyl)-2-propanolate, form upon oxidation of various molecular iridium complexes, for instance [Cp*Ir(LX)OH] or [(cod)Ir(LX)] (Cp*=pentamethylcyclopentadienyl, cod=cis-cis,1,5-cyclooctadiene) when exposed to oxidative conditions, such as sodium periodate (NaIO.sub.4) in aqueous solution at ambient conditions.

  18. Complex Hamiltonian Dynamics

    CERN Document Server

    Bountis, Tassos

    2012-01-01

    This book introduces and explores modern developments in the well established field of Hamiltonian dynamical systems. It focuses on high degree-of-freedom systems and the transitional regimes between regular and chaotic motion. The role of nonlinear normal modes is highlighted and the importance of low-dimensional tori in the resolution of the famous FPU paradox is emphasized. Novel powerful numerical methods are used to study localization phenomena and distinguish order from strongly and weakly chaotic regimes. The emerging hierarchy of complex structures in such regimes gives rise to particularly long-lived patterns and phenomena called quasi-stationary states, which are explored in particular in the concrete setting of one-dimensional Hamiltonian lattices and physical applications in condensed matter systems.  The self-contained and pedagogical approach is blended with a unique balance between mathematical rigor, physics insights and concrete applications. End of chapter exercises and (more demanding) res...

  19. Turbulence in complex terrain

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Jakob [Risoe National Lab., Wind Energy and Atmosheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    The purpose of this work is to develop a model of the spectral velocity-tensor in neutral flow over complex terrain. The resulting equations are implemented in a computer code using the mean flow generated by a linear mean flow model as input. It estimates turbulence structure over hills (except on the lee side if recirculation is present) in the so-called outer layer and also models the changes in turbulence statistics in the vicinity roughness changes. The generated turbulence fields are suitable as input for dynamic load calculations on wind turbines and other tall structures and is under implementation in the collection of programs called WA{sup s}P Engineering. (au) EFP-97; EU-JOULE-3. 15 refs.

  20. Evolution of complex dynamics

    Science.gov (United States)

    Wilds, Roy; Kauffman, Stuart A.; Glass, Leon

    2008-09-01

    We study the evolution of complex dynamics in a model of a genetic regulatory network. The fitness is associated with the topological entropy in a class of piecewise linear equations, and the mutations are associated with changes in the logical structure of the network. We compare hill climbing evolution, in which only mutations that increase the fitness are allowed, with neutral evolution, in which mutations that leave the fitness unchanged are allowed. The simple structure of the fitness landscape enables us to estimate analytically the rates of hill climbing and neutral evolution. In this model, allowing neutral mutations accelerates the rate of evolutionary advancement for low mutation frequencies. These results are applicable to evolution in natural and technological systems.

  1. Early AIDS dementia complex

    International Nuclear Information System (INIS)

    Mountz, J.M.; Speed, N.M.; Adams, K.; Schwartz, J.A.; Gross, M.D.; Ostrow, D.G.

    1988-01-01

    A frequent complication of the acquired immunodeficiency syndrome (AIDS) is AIDS dementia complex (ADC). The authors evaluated seven patients with AIDS (aged 28-55 years, all male) for ADC by psychiatric evaluation, neuropsychological testing, CT scanning, and IMP-SPECT. Six of seven patients exhibited cognitive or behavioral abnormalities. Neuropsychological testing showed general deficits but no cases of explicit dementia. SPECT showed marked abnormalities in two cases: posterior temporal-parietal diminution of tracer uptake in one case (posterior/anterior=0.81) and marked right/left subcortical asymmetry (1.17) in the other. In three additional cases there was asymmetric tracer uptake in the subcortical and parietal regions. CT findings were normal in all seven cases. The authors conclude that functional imaging with the use of IMP-SPECT may be a useful method to follow ADC progression and response to therapy

  2. Measurement of complex surfaces

    International Nuclear Information System (INIS)

    Brown, G.M.

    1993-05-01

    Several of the components used in coil fabrication involve complex surfaces and dimensions that are not well suited to measurements using conventional dimensional measuring equipment. Some relatively simple techniques that are in use in the SSCL Magnet Systems Division (MSD) for incoming inspection will be described, with discussion of their suitability for specific applications. Components that are submitted for MSD Quality Assurance (QA) dimensional inspection may be divided into two distinct categories; the first category involves components for which there is an approved drawing and for which all nominal dimensions are known; the second category involves parts for which 'reverse engineering' is required, the part is available but there are no available drawings or dimensions. This second category typically occurs during development of coil end parts and coil turn filler parts where it is necessary to manually shape the part and then measure it to develop the information required to prepare a drawing for the part

  3. Complexity Science for Simpletons

    Directory of Open Access Journals (Sweden)

    Feinstein C. A.

    2006-07-01

    Full Text Available In this article, we shall describe some of the most interesting topics in the subject of Complexity Science for a general audience. Anyone with a solid foundation in high school mathematics (with some calculus and an elementary understanding of computer programming will be able to follow this article. First, we shall explain the significance of the P versus NP problem and solve it. Next, we shall describe two other famous mathematics problems, the Collatz 3n+ 1 Conjecture and the Riemann Hypothesis, and show how both Chaitin’s incompleteness theorem and Wolfram’s notion of “computational irreducibility” are important for understanding why no one has, as of yet, solved these two problems.

  4. The Complex Cepstrum - Revisited

    Science.gov (United States)

    Kemerait, R. C., Sr.

    2016-12-01

    Since this paper comes at the twilight of my career, it is appropriate to share my views on a subject very dear to my heart and to my long career. In 2004 "From Frequency to Quefrency: A History of the Cepstrum" was published in the IEEE Signal Processing magazine. There is no question that the authors, Alan V. Oppenheim and Ronald W. Schafer, were pioneers in this area of research, and this publication documents their involvement quite nicely. In parallel research also performed in the 1960's, Childers, et. al., renamed the original "Cepstrum" to the "Power Cepstrum" to avoid confusion with the principal topic of their research, that being the "Complex Cepstrum." The term "Power Cepstrum" has become widely used in the literature since that time. The Childers team, including Dr. Kemerait, published a summary of their work, as of that date, in the IEEE Proceedings of October 1977, and titled the article "The Cepstrum: A Guide to Processing." In the subsequent 40 years, Dr. Kemerait has continued to research cepstral techniques applied to many diverse problems; however, his primary research has been on estimating the depth of underground and underwater events. He has also applied these techniques to biomedical data: EEG, EKG, and Visua-evoked responses as well as on hydroacoustic data ; thereby, determining the "bubble pulse frequency", and the depths of the explosion and the ocean depth at the explosion point. He has also used cepstral techniques in the processing of ground penetrating radar, speech, machine diagnostics, and, throughout these years, seismic data. This paper emphasizes his recent improvements in processing primarily seismic and infrasound data associated with nuclear treaty monitoring. The emphasis is mainly on the recent improvements and the automation of the Complex Cepstrum process.

  5. Complex wounds Feridas complexas

    Directory of Open Access Journals (Sweden)

    Marcus Castro Ferreira

    2006-01-01

    Full Text Available Complex wound is the term used more recently to group those well-known difficult wounds, either chronic or acute, that challenge medical and nursing teams. They defy cure using conventional and simple "dressings" therapy and currently have a major socioeconomic impact. The purpose of this review is to bring these wounds to the attention of the health-care community, suggesting that they should be treated by multidisciplinary teams in specialized hospital centers. In most cases, surgical treatment is unavoidable, because the extent of skin and subcutaneous tissue loss requires reconstruction with grafts and flaps. New technologies, such as the negative pressure device, should be introduced. A brief review is provided of the major groups of complex wounds-diabetic wounds, pressure sores, chronic venous ulcers, post-infection soft-tissue gangrenes, and ulcers resulting from vasculitis.Ferida complexa é uma nova definição para identificar aquelas feridas crônicas e algumas agudas já bem conhecidas e que desafiam equipes médicas e de enfermagem. São difíceis de serem resolvidas usando tratamentos convencionais e simples curativos. Têm atualmente grande impacto sócio-econômico. Esta revisão procura atrair atenção da comunidade de profissionais de saúde para estas feridas, sugerindo que devam ser tratadas por equipe multidisciplinar em centro hospitalar especializado. Na maioria dos casos o tratamento cirúrgico deve ser indicado, uma vez que a perda de pele e tecido subcutâneo é extensa, necessitando de reconstrução com enxertos e retalhos. Nova tecnologia, como uso da terapia por pressão negativa foi introduzido. Breves comentários sobre os principais grupos de feridas complexas: pé diabético, úlceras por pressão, úlceras venosas, síndrome de Fournier e vasculites.

  6. Complex sleep apnea syndrome

    Directory of Open Access Journals (Sweden)

    Wang J

    2013-07-01

    Full Text Available Juan Wang,1,* Yan Wang,1,* Jing Feng,1,2 Bao-yuan Chen,1 Jie Cao1 1Respiratory Department of Tianjin Medical University General Hospital, Tianjin, People's Republic of China; 2Division of Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, USA *The first two authors contributed equally to this work Abstract: Complex sleep apnea syndrome (CompSAS is a distinct form of sleep-disordered breathing characterized as central sleep apnea (CSA, and presents in obstructive sleep apnea (OSA patients during initial treatment with a continuous positive airway pressure (CPAP device. The mechanisms of why CompSAS occurs are not well understood, though we have a high loop gain theory that may help to explain it. It is still controversial regarding the prevalence and the clinical significance of CompSAS. Patients with CompSAS have clinical features similar to OSA, but they do exhibit breathing patterns like CSA. In most CompSAS cases, CSA events during initial CPAP titration are transient and they may disappear after continued CPAP use for 4–8 weeks or even longer. However, the poor initial experience of CompSAS patients with CPAP may not be avoided, and nonadherence with continued therapy may often result. Treatment options like adaptive servo-ventilation are available now that may rapidly resolve the disorder and relieve the symptoms of this disease with the potential of increasing early adherence to therapy. But these approaches are associated with more expensive and complicated devices. In this review, the definition, potential plausible mechanisms, clinical characteristics, and treatment approaches of CompSAS will be summarized. Keywords: complex sleep apnea syndrome, obstructive sleep apnea, central sleep apnea, apnea threshold, continuous positive airway pressure, adaptive servo-ventilation

  7. Amphotericin B Lipid Complex Injection

    Science.gov (United States)

    Amphotericin B lipid complex injection is used to treat serious, possibly life-threatening fungal infections in people who did ... respond or are unable to tolerate conventional amphotericin B therapy. Amphotericin B lipid complex injection is in ...

  8. [Tissue-specific nucleoprotein complexes].

    Science.gov (United States)

    Riadnova, I Iu; Shataeva, L K; Khavinson, V Kh

    2000-01-01

    A method of isolation of native nucleorprotein complexes from cattle cerebral cortex, thymus, and liver was developed. Compositions of these complexes were studied by means of gel-chromatography and ion-exchange chromatography. These preparations were shown to consist of several fractions of proteins and their complexes differ by molecular mass and electro-chemical properties. Native nucleoprotein complexes revealed high tissue specific activity, which was not species-specific.

  9. Cooperativity of complex salt bridges

    OpenAIRE

    Gvritishvili, Anzor G.; Gribenko, Alexey V.; Makhatadze, George I.

    2008-01-01

    The energetic contribution of complex salt bridges, in which one charged residue (anchor residue) forms salt bridges with two or more residues simultaneously, has been suggested to have importance for protein stability. Detailed analysis of the net energetics of complex salt bridge formation using double- and triple-mutant cycle analysis revealed conflicting results. In two cases, it was shown that complex salt bridge formation is cooperative, i.e., the net strength of the complex salt bridge...

  10. Uranium nucleophilic carbene complexes

    International Nuclear Information System (INIS)

    Tourneux, Jean-Christophe

    2012-01-01

    The only stable f-metal carbene complexes (excluding NHC) metals f present R 2 C 2- groups having one or two phosphorus atoms in the central carbon in alpha position. The objective of this work was to develop the chemistry of carbenes for uranium (metal 5f) with the di-anion C{Ph 2 P(=S)} 2 2- (SCS 2- ) to extend the organometallic chemistry of this element in its various oxidation states (+3-+6), and to reveal the influence of the 5f orbitals on the nature and reactivity of the double bond C=U. We first isolated the reactants M(SCHS) (M = Li and K) and demonstrated the role of the cation M + on the evolution of the di-anion M 2 SCS (M = Li, K, Tl) which is transformed into LiSCHS in THF or into product of intramolecular cyclization K 2 [C(PhPS) 2 (C 6 H 4 )]. We have developed the necessary conditions mono-, bis- and tris-carbene directly from the di-anion SCS 2- and UCl 4 , as the precursor used in uranium chemistry. The protonolysis reactions of amides compounds (U-NEt 2 ) by the neutral ligand SCH 2 S were also studied. The compounds [Li(THF)] 2 [U(SCS)Cl 3 ] and [U(SCS)Cl 2 (THF) 2 ] were then used to prepare a variety of cyclopentadienyl and mono-cyclo-octa-tetra-enyliques uranium(IV) carbene compounds of the DFT analysis of compounds [M(SCS)Cl 2 (py) 2 ] and [M(Cp) 2 (SCS)] (M = U, Zr) reveals the strong polarization of the M=C double bond, provides information on the nature of the σ and π interactions in this binding, and shows the important role of f orbitals. The influence of ancillary ligands on the M=C bond is revealed by examining the effects of replacing Cl - ligands and pyridine by C 5 H 5 - groups. Mulliken and NBO analyzes show that U=C bond, unlike the Zr=C bond, is not affected by the change in environment of the metal center. While the oxidation tests of carbene complexes of U(IV) were disappointing, the first carbene complex of uranium (VI), [UO 2 (SCS)(THF) 2 ], was isolated with the uranyl ion UO 2 2+ . The reactions of compounds UO 2 X 2

  11. Complex mixtures biostudies

    International Nuclear Information System (INIS)

    Springer, D.L.

    1987-01-01

    The objective of the project is to identify potential adverse biological activities associated with human exposures to complex organic mixtures (COM) from energy-related industries. Studies to identify the influence of chemical class fractions from a COM on the initiating activity of a known carcinogen, benzo(a)pyrene (BaP), demonstrated that the polycyclic aromatic hydrocarbons (PAH) and nitrogen-containing polycyclic aromatic compound (NPAC) fractions were the most effective inhibitors of initiation. In an effort to determine the contribution of BaP to the initiating activity of the COM, binding of radiolabeled BaP to mouse skin DNA was measured. Results indicated that binding of BaP to DNA decreased in the presence of the COM so that at initiating COM doses, BaP binding was near the limit detection. Addition of unlabeled BaP to the COM at an amount similar to that originally present in the COM did not significantly increase the binding. Studies to determine the rates of disappearance of carcinogenic PAH from the site of application on the skin indicated that half-lives for PAH differed by a factor of about 2. Analytical methods developed to identify PAH from COM which covalently bind to DNA demonstrated that the lower level of detection is approximately 200 picograms. Developmental studies demonstrated that both pregnant rats and mice treated dermally with a high-boiling COM developed fetuses with major malformations including cleft palate, small lungs, edema, and sagittal suture hemorrhages. 3 figures, 5 tables

  12. Managing Complex Environmental Risks

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Mikael [Karlstad Univ. (Sweden). Dept. of Environmental Sciences

    2006-09-15

    Environmental and public health risks are often handled in a process in which experts, and sometimes policy makers, try their best to quantitatively assess, evaluate and manage risks. This approach harmonises with mainstream interpretations of sustainable development, which aim at defining a desirable relationship between human and natural systems, for instance by policies that define limit values of different forms of disturbances. However, under conditions of high scientific incertitude, diverging values and distrust, this approach is far from satisfactory. The use of cell phones, hazardous chemicals, nuclear or fossil energy systems, and modern biotechnology are examples of activities causing such risks with high complexity. Against this background, a complementary interpretation of the concept of sustainable development is suggested. This interpretation is operationalised through new formulations of three common principles for public risk management; the precautionary principle, the polluter pays principle and the principle of public participation. Implementation of these reformulated principles would challenge some foundations of present mainstream views on environmental decision-making, but would on the other hand contribute to improved practices for long-term human welfare and planetary survival (full text of contribution)

  13. Managing Complex Environmental Risks

    International Nuclear Information System (INIS)

    Karlsson, Mikael

    2006-01-01

    Environmental and public health risks are often handled in a process in which experts, and sometimes policy makers, try their best to quantitatively assess, evaluate and manage risks. This approach harmonises with mainstream interpretations of sustainable development, which aim at defining a desirable relationship between human and natural systems, for instance by policies that define limit values of different forms of disturbances. However, under conditions of high scientific incertitude, diverging values and distrust, this approach is far from satisfactory. The use of cell phones, hazardous chemicals, nuclear or fossil energy systems, and modern biotechnology are examples of activities causing such risks with high complexity. Against this background, a complementary interpretation of the concept of sustainable development is suggested. This interpretation is operationalised through new formulations of three common principles for public risk management; the precautionary principle, the polluter pays principle and the principle of public participation. Implementation of these reformulated principles would challenge some foundations of present mainstream views on environmental decision-making, but would on the other hand contribute to improved practices for long-term human welfare and planetary survival (full text of contribution)

  14. On Measuring the Complexity of Networks: Kolmogorov Complexity versus Entropy

    Directory of Open Access Journals (Sweden)

    Mikołaj Morzy

    2017-01-01

    Full Text Available One of the most popular methods of estimating the complexity of networks is to measure the entropy of network invariants, such as adjacency matrices or degree sequences. Unfortunately, entropy and all entropy-based information-theoretic measures have several vulnerabilities. These measures neither are independent of a particular representation of the network nor can capture the properties of the generative process, which produces the network. Instead, we advocate the use of the algorithmic entropy as the basis for complexity definition for networks. Algorithmic entropy (also known as Kolmogorov complexity or K-complexity for short evaluates the complexity of the description required for a lossless recreation of the network. This measure is not affected by a particular choice of network features and it does not depend on the method of network representation. We perform experiments on Shannon entropy and K-complexity for gradually evolving networks. The results of these experiments point to K-complexity as the more robust and reliable measure of network complexity. The original contribution of the paper includes the introduction of several new entropy-deceiving networks and the empirical comparison of entropy and K-complexity as fundamental quantities for constructing complexity measures for networks.

  15. Technetium complexation by macrocyclic compounds

    International Nuclear Information System (INIS)

    Li Fan Yu.

    1983-01-01

    Research in nuclear medicine are directed towards the labelling of biological molecules, however, sup(99m)Tc does not show sufficient affinity for these molecules. The aim of this study was to evaluate the ability of macrocyclic compounds to bind strongly technetium in order to be used as complexation intermediate. The reducing agents used were a stannous complex and sodium dithionite. Cryptates and polyesters are not good complexing agents. They form two complexes: a 2:1 sandwich complex or 3:2 and a 1:1 complex. Cyclams are good complexing agents for technetium their complexations strength was determined by competition with pyrophosphate, gluconate and DTPA. Using the method of ligand exchange, the oxidation state of technetium in the Tc-cyclam complex was IV or V. They are 1:1 cationic complexes, the complex charge is +1. The biodistribution in rats of labelling solutions containing (cyclam 14 ane N 4 ) C 12 H 25 shows a good urinary excretion without intoxication risks [fr

  16. Complexity a very short introduction

    CERN Document Server

    Holland, John H

    2014-01-01

    The importance of complexity is well-captured by Hawking's comment: "Complexity is the science of the 21st century". From the movement of flocks of birds to the Internet, environmental sustainability, and market regulation, the study and understanding of complex non-linear systems has become highly influential over the last 30 years. In this Very Short Introduction, one of the leading figures in the field, John Holland, introduces the key elements and conceptual framework of complexity. From complex physical systems such as fluid flow and the difficulties of predicting weather, to complex adaptive systems such as the highly diverse and interdependent ecosystems of rainforests, he combines simple, well-known examples - Adam Smith's pin factory, Darwin's comet orchid, and Simon's 'watchmaker' - with an account of the approaches, involving agents and urn models, taken by complexity theory. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost eve...

  17. Complexity of formation in holography

    International Nuclear Information System (INIS)

    Chapman, Shira; Marrochio, Hugo; Myers, Robert C.

    2017-01-01

    It was recently conjectured that the quantum complexity of a holographic boundary state can be computed by evaluating the gravitational action on a bulk region known as the Wheeler-DeWitt patch. We apply this complexity=action duality to evaluate the ‘complexity of formation’ (DOI: 10.1103/PhysRevLett.116.191301; 10.1103/PhysRevD.93.086006), i.e. the additional complexity arising in preparing the entangled thermofield double state with two copies of the boundary CFT compared to preparing the individual vacuum states of the two copies. We find that for boundary dimensions d>2, the difference in the complexities grows linearly with the thermal entropy at high temperatures. For the special case d=2, the complexity of formation is a fixed constant, independent of the temperature. We compare these results to those found using the complexity=volume duality.

  18. Complexity of formation in holography

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Shira [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada); Marrochio, Hugo [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada); Department of Physics & Astronomy and Guelph-Waterloo Physics Institute,University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Myers, Robert C. [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada)

    2017-01-16

    It was recently conjectured that the quantum complexity of a holographic boundary state can be computed by evaluating the gravitational action on a bulk region known as the Wheeler-DeWitt patch. We apply this complexity=action duality to evaluate the ‘complexity of formation’ (DOI: 10.1103/PhysRevLett.116.191301; 10.1103/PhysRevD.93.086006), i.e. the additional complexity arising in preparing the entangled thermofield double state with two copies of the boundary CFT compared to preparing the individual vacuum states of the two copies. We find that for boundary dimensions d>2, the difference in the complexities grows linearly with the thermal entropy at high temperatures. For the special case d=2, the complexity of formation is a fixed constant, independent of the temperature. We compare these results to those found using the complexity=volume duality.

  19. Carney complex (CNC

    Directory of Open Access Journals (Sweden)

    Bertherat Jérôme

    2006-06-01

    Full Text Available Abstract The Carney complex (CNC is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD. PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A, has been identified to encode the regulatory subunit (R1A of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65 % of CNC index cases, and may be present in about 80 % of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing

  20. Carney complex (CNC).

    Science.gov (United States)

    Bertherat, Jérôme

    2006-06-06

    The Carney complex (CNC) is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A), has been identified to encode the regulatory subunit (R1A) of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65% of CNC index cases, and may be present in about 80% of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing's syndrome due to PPNAD.

  1. Complexity Management In Projects Between Rational Momentum And Complex Conditions

    DEFF Research Database (Denmark)

    Mac, Anita; Schlamovitz, Jesper

    2015-01-01

    Abstract: This study takes its departure in a model of complexity, developed by Stacey (1993), to test and discuss its practical benefit as perceived by practicing project managers. Based on a survey, the study finds that complexity is a phenomenon recognized by project managers, and complexity...... management is associated with benefits in the development of tasks and managing stakeholders. It is also associated with some difficulty in terms of an increased need for dialogue and a risk of creating goal ambiguity. Based on the findings, we conclude that classical project management approaches can...... benefit from incorporating complexity management....

  2. Complexity management in projects between rational momentum and complex conditions

    DEFF Research Database (Denmark)

    Mac, Anita; Schlamovitz, Jesper

    This study takes its departure in a model of complexity, developed by Stacey (1993), to test and discuss its practical benefit as perceived by practicing project managers. Based on a survey, the study finds that complexity is a phenomenon recognized by project managers, and complexity management...... is associated with benefits in the development of tasks and managing stakeholders. It is also associated with some difficulty in terms of an increased need for dialogue and a risk of creating goal ambiguity. Based on the findings, we conclude that classical project management approaches can benefit from...... incorporating complexity management....

  3. Physical Complexity and Cognitive Evolution

    Science.gov (United States)

    Jedlicka, Peter

    Our intuition tells us that there is a general trend in the evolution of nature, a trend towards greater complexity. However, there are several definitions of complexity and hence it is difficult to argue for or against the validity of this intuition. Christoph Adami has recently introduced a novel measure called physical complexity that assigns low complexity to both ordered and random systems and high complexity to those in between. Physical complexity measures the amount of information that an organism stores in its genome about the environment in which it evolves. The theory of physical complexity predicts that evolution increases the amount of `knowledge' an organism accumulates about its niche. It might be fruitful to generalize Adami's concept of complexity to the entire evolution (including the evolution of man). Physical complexity fits nicely into the philosophical framework of cognitive biology which considers biological evolution as a progressing process of accumulation of knowledge (as a gradual increase of epistemic complexity). According to this paradigm, evolution is a cognitive `ratchet' that pushes the organisms unidirectionally towards higher complexity. Dynamic environment continually creates problems to be solved. To survive in the environment means to solve the problem, and the solution is an embodied knowledge. Cognitive biology (as well as the theory of physical complexity) uses the concepts of information and entropy and views the evolution from both the information-theoretical and thermodynamical perspective. Concerning humans as conscious beings, it seems necessary to postulate an emergence of a new kind of knowledge - a self-aware and self-referential knowledge. Appearence of selfreflection in evolution indicates that the human brain reached a new qualitative level in the epistemic complexity.

  4. Forecasting in Complex Systems

    Science.gov (United States)

    Rundle, J. B.; Holliday, J. R.; Graves, W. R.; Turcotte, D. L.; Donnellan, A.

    2014-12-01

    Complex nonlinear systems are typically characterized by many degrees of freedom, as well as interactions between the elements. Interesting examples can be found in the areas of earthquakes and finance. In these two systems, fat tails play an important role in the statistical dynamics. For earthquake systems, the Gutenberg-Richter magnitude-frequency is applicable, whereas for daily returns for the securities in the financial markets are known to be characterized by leptokurtotic statistics in which the tails are power law. Very large fluctuations are present in both systems. In earthquake systems, one has the example of great earthquakes such as the M9.1, March 11, 2011 Tohoku event. In financial systems, one has the example of the market crash of October 19, 1987. Both were largely unexpected events that severely impacted the earth and financial systems systemically. Other examples include the M9.3 Andaman earthquake of December 26, 2004, and the Great Recession which began with the fall of Lehman Brothers investment bank on September 12, 2013. Forecasting the occurrence of these damaging events has great societal importance. In recent years, national funding agencies in a variety of countries have emphasized the importance of societal relevance in research, and in particular, the goal of improved forecasting technology. Previous work has shown that both earthquakes and financial crashes can be described by a common Landau-Ginzburg-type free energy model. These metastable systems are characterized by fat tail statistics near the classical spinodal. Correlations in these systems can grow and recede, but do not imply causation, a common source of misunderstanding. In both systems, a common set of techniques can be used to compute the probabilities of future earthquakes or crashes. In this talk, we describe the basic phenomenology of these systems and emphasize their similarities and differences. We also consider the problem of forecast validation and verification

  5. Bell Inequalities for Complex Networks

    Science.gov (United States)

    2015-10-26

    AFRL-AFOSR-VA-TR-2015-0355 YIP Bell Inequalities for Complex Networks Greg Ver Steeg UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES Final Report 10/26...performance report PI: Greg Ver Steeg Young Investigator Award Grant Title: Bell Inequalities for Complex Networks Grant #: FA9550-12-1-0417 Reporting...October 20, 2015 Final Report for “Bell Inequalities for Complex Networks” Greg Ver Steeg Abstract This effort studied new methods to understand the effect

  6. Increasing complexity with quantum physics.

    Science.gov (United States)

    Anders, Janet; Wiesner, Karoline

    2011-09-01

    We argue that complex systems science and the rules of quantum physics are intricately related. We discuss a range of quantum phenomena, such as cryptography, computation and quantum phases, and the rules responsible for their complexity. We identify correlations as a central concept connecting quantum information and complex systems science. We present two examples for the power of correlations: using quantum resources to simulate the correlations of a stochastic process and to implement a classically impossible computational task.

  7. Epidemic processes in complex networks

    OpenAIRE

    Pastor Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-01-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The t...

  8. Rhodium complexes as therapeutic agents.

    Science.gov (United States)

    Ma, Dik-Lung; Wang, Modi; Mao, Zhifeng; Yang, Chao; Ng, Chan-Tat; Leung, Chung-Hang

    2016-02-21

    The landscape of inorganic medicinal chemistry has been dominated by the investigation of platinum, and to a lesser extent ruthenium, complexes over the past few decades. Recently, complexes based on other metal centers such as rhodium have attracted attention due to their tunable chemical and biological properties as well as distinct mechanisms of action. This perspective highlights recent examples of rhodium complexes that show diverse biological activities against various targets, including enzymes and protein-protein interactions.

  9. Complexity leadership: a healthcare imperative.

    Science.gov (United States)

    Weberg, Dan

    2012-01-01

    The healthcare system is plagued with increasing cost and poor quality outcomes. A major contributing factor for these issues is that outdated leadership practices, such as leader-centricity, linear thinking, and poor readiness for innovation, are being used in healthcare organizations. Complexity leadership theory provides a new framework with which healthcare leaders may practice leadership. Complexity leadership theory conceptualizes leadership as a continual process that stems from collaboration, complex systems thinking, and innovation mindsets. Compared to transactional and transformational leadership concepts, complexity leadership practices hold promise to improve cost and quality in health care. © 2012 Wiley Periodicals, Inc.

  10. Complexity Intelligence and Cultural Coaching:

    Directory of Open Access Journals (Sweden)

    Jan Inglis

    2005-06-01

    Full Text Available In this article, we present the term complexity intelligence as a useful moniker to describe the reasoning ability, emotional capacity and social cognition necessary to meet the challenges of our prevailing life conditions. We suggest that, as a society and as individuals, we develop complexity intelligence as we navigate the gap between our current capacities and the capacities needed to respond to the next stage of complex challenges in our lives. We further suggest that it is possible to stimulate and support the emergence of complexity intelligence in a society, but we need a new form of social change agent - a cultural coach, to midwife its emergence.

  11. Measuring Complexity of SAP Systems

    Directory of Open Access Journals (Sweden)

    Ilja Holub

    2016-10-01

    Full Text Available The paper discusses the reasons of complexity rise in ERP system SAP R/3. It proposes a method for measuring complexity of SAP. Based on this method, the computer program in ABAP for measuring complexity of particular SAP implementation is proposed as a tool for keeping ERP complexity under control. The main principle of the measurement method is counting the number of items or relations in the system. The proposed computer program is based on counting of records in organization tables in SAP.

  12. Technetium-aspirin molecule complexes

    International Nuclear Information System (INIS)

    El-Shahawy, A.S.; Mahfouz, R.M.; Aly, A.A.M.; El-Zohry, M.

    1993-01-01

    Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author)

  13. Cyclomatic Complexity: theme and variations

    Directory of Open Access Journals (Sweden)

    Brian Henderson-Sellers

    1993-11-01

    Full Text Available Focussing on the "McCabe family" of measures for the decision/logic structure of a program, leads to an evaluation of extensions to modularization, nesting and, potentially, to object-oriented program structures. A comparison of rated, operating and essential complexities of programs suggests two new metrics: "inessential complexity" as a measure of unstructuredness and "product complexity" as a potential objective measure of structural complexity. Finally, nesting and abstraction levels are considered, especially as to how metrics from the "McCabe family" might be applied in an object-oriented systems development environment.

  14. Complexity-management in SME : organization of complex relationships

    NARCIS (Netherlands)

    Gregus, M.; Mandorf, S.

    2009-01-01

    The complexity of companies' environment IS growmg. Complexity management and restructuring of small and medium-sized enterprises (SME) become big challenges of business studies in the next future. A chance could be seen in the use of e-business strategies and the implementation of information

  15. Complex Constructivism: A Theoretical Model of Complexity and Cognition

    Science.gov (United States)

    Doolittle, Peter E.

    2014-01-01

    Education has long been driven by its metaphors for teaching and learning. These metaphors have influenced both educational research and educational practice. Complexity and constructivism are two theories that provide functional and robust metaphors. Complexity provides a metaphor for the structure of myriad phenomena, while constructivism…

  16. Complexity in phonology: The complex consonants of simple CV ...

    African Journals Online (AJOL)

    The main objective of this article is to investigate the interplay of simplicity and complexity in the phonological structure of Zezuru. The article argues that Zezuru affricates, prenasalised consonants (NCs) and velarised consonants (Cws) are subsegmentally complex segments which function as simple onsets. Treating them ...

  17. Workshop on Recommendation in Complex Scenarios (ComplexRec 2017)

    DEFF Research Database (Denmark)

    Bogers, Toine; Koolen, Marijn; Mobasher, Bamshad

    2017-01-01

    Recommendation algorithms for ratings prediction and item ranking have steadily matured during the past decade. However, these state-of-the-art algorithms are typically applied in relatively straightforward scenarios. In reality, recommendation is often a more complex problem: it is usually just...... a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

  18. ComplexViewer: visualization of curated macromolecular complexes.

    Science.gov (United States)

    Combe, Colin W; Sivade, Marine Dumousseau; Hermjakob, Henning; Heimbach, Joshua; Meldal, Birgit H M; Micklem, Gos; Orchard, Sandra; Rappsilber, Juri

    2017-11-15

    Proteins frequently function as parts of complexes, assemblages of multiple proteins and other biomolecules, yet network visualizations usually only show proteins as parts of binary interactions. ComplexViewer visualizes interactions with more than two participants and thereby avoids the need to first expand these into multiple binary interactions. Furthermore, if binding regions between molecules are known then these can be displayed in the context of the larger complex. freely available under Apache version 2 license; EMBL-EBI Complex Portal: http://www.ebi.ac.uk/complexportal; Source code: https://github.com/MICommunity/ComplexViewer; Package: https://www.npmjs.com/package/complexviewer; http://biojs.io/d/complexviewer. Language: JavaScript; Web technology: Scalable Vector Graphics; Libraries: D3.js. colin.combe@ed.ac.uk or juri.rappsilber@ed.ac.uk. © The Author 2017. Published by Oxford University Press.

  19. Dynamic complexity: plant receptor complexes at the plasma membrane.

    Science.gov (United States)

    Burkart, Rebecca C; Stahl, Yvonne

    2017-12-01

    Plant receptor complexes at the cell surface perceive many different external and internal signalling molecules and relay these signals into the cell to regulate development, growth and immunity. Recent progress in the analyses of receptor complexes using different live cell imaging approaches have shown that receptor complex formation and composition are dynamic and take place at specific microdomains at the plasma membrane. In this review we focus on three prominent examples of Arabidopsis thaliana receptor complexes and how their dynamic spatio-temporal distribution at the PM has been studied recently. We will elaborate on the newly emerging concept of plasma membrane microdomains as potential hubs for specific receptor complex assembly and signalling outputs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Intermittency in Complex Flows

    Science.gov (United States)

    Ben Mahjoub, Otman; Redondo, Jose M.

    2017-04-01

    Experimental results of the complex turbulent wake of a cilinder in 2D [1] and 3D flows [2] were used to investigate the scaling of structure functions, similar research was also performed on wave propagation and breaking in the Ocean [3], in the the stratified Atmosphere (ABL) [4] and in a 100large flume (UPC) for both regular and irregular waves, where long time series of waves propagating and generating breaking turbulence velocity rms and higher order measurements were taken in depth. [3,5] by means of a velocimeter SONTEK3-D. The probability distribution functions of the velocity differences and their non Gaussian distribution related to the energy spectrum indicate that irregularity is an important source of turbulence. From Kolmogorov's K41 and K61 intermittency correction: the p th-order longitudinal velocity structure function δul at scale l in the inertial range of three-dimensional fully developed turbulence is related by ⟨δup⟩ = ⟨(u(x+ l)- u(x))p⟩ ˜ ɛp0/3lp/3 l where ⟨...⟩ represents the spatial average over flow domain, with ɛ0 the mean energy dissipation per unit mass and l is the separation distance. The importance of the random nature of the energy dissipation led to the K62 theory of intermittency, but locality and non-homogeneity are key issues. p p/3 p/3 ξd ⟨δul⟩ ˜ ⟨ɛl ⟩l ˜ l and ξp = p 3 + τp/3 , where now ɛl is a fractal energy dissipation at scale l, τp/3 is the scaling of and ξp is the scaling exponent of the velocity structure function of order p. Both in K41 and K62, the structure functions of third order related to skewness is ξ3 = 1. But this is not true either. We show that scaling exponents ξp do deviate from early studies that only investigated homogeneous turbulence, where a large inertial range dominates. The use of multi-fractal analysis and improvements on Structure function calculations on standard Enhanced mixing is an essential property of turbulence and efforts to alter and to control

  1. Complex Variables throughout the Curriculum

    Science.gov (United States)

    D'Angelo, John P.

    2017-01-01

    We offer many specific detailed examples, several of which are new, that instructors can use (in lecture or as student projects) to revitalize the role of complex variables throughout the curriculum. We conclude with three primary recommendations: revise the syllabus of Calculus II to allow early introductions of complex numbers and linear…

  2. Information geometric methods for complexity

    Science.gov (United States)

    Felice, Domenico; Cafaro, Carlo; Mancini, Stefano

    2018-03-01

    Research on the use of information geometry (IG) in modern physics has witnessed significant advances recently. In this review article, we report on the utilization of IG methods to define measures of complexity in both classical and, whenever available, quantum physical settings. A paradigmatic example of a dramatic change in complexity is given by phase transitions (PTs). Hence, we review both global and local aspects of PTs described in terms of the scalar curvature of the parameter manifold and the components of the metric tensor, respectively. We also report on the behavior of geodesic paths on the parameter manifold used to gain insight into the dynamics of PTs. Going further, we survey measures of complexity arising in the geometric framework. In particular, we quantify complexity of networks in terms of the Riemannian volume of the parameter space of a statistical manifold associated with a given network. We are also concerned with complexity measures that account for the interactions of a given number of parts of a system that cannot be described in terms of a smaller number of parts of the system. Finally, we investigate complexity measures of entropic motion on curved statistical manifolds that arise from a probabilistic description of physical systems in the presence of limited information. The Kullback-Leibler divergence, the distance to an exponential family and volumes of curved parameter manifolds, are examples of essential IG notions exploited in our discussion of complexity. We conclude by discussing strengths, limits, and possible future applications of IG methods to the physics of complexity.

  3. Holistic education and complexity thinking

    NARCIS (Netherlands)

    Jörg, T.

    2007-01-01

    Paper proposal for the SIG Holistic Education at AERA 2007 Title: Holistic Education and Complexity Thinking Ton Jörg IVLOS Institute of Education University of Utrecht The Netherlands A.G.D.Jorg@ivlos.uu.nl ABSTRACT In this paper I link complexity thinking with Holistic Education (HE). It is a

  4. Communication Analysis of Information Complexes.

    Science.gov (United States)

    Malik, M. F.

    Communication analysis is a tool for perceptual assessment of existing or projected information complexes, i.e., an established reality perceived by one or many humans. An information complex could be of a physical nature, such as a building, landscape, city street; or of a pure informational nature, such as a film, television program,…

  5. Team dynamics in complex projects

    NARCIS (Netherlands)

    Oeij, P.; Vroome, E.E.M. de; Dhondt, S.; Gaspersz, J.B.R.

    2012-01-01

    Complexity of projects is hotly debated and a factor which affects innovativeness of team performance. Much attention in the past is paid to technical complexity and many issues are related to natural and physical sciences. A growing awareness of the importance of socioorganisational issues is

  6. Producers' Complex Risk Management Choices

    NARCIS (Netherlands)

    Pennings, J.M.E.; Isengildina, O.; Irwin, S.H.; Garcia, P.; Good, D.L.

    2008-01-01

    Producers have a wide variety of risk management instruments available, making their choice(s) complex. The way producers deal with this complexity can vary and may influence the impact that the determinants, such as risk aversion, have on their choices. A recently developed choice bracketing

  7. Complexity control in statistical learning

    Indian Academy of Sciences (India)

    complexity of the class of models from which we are to choose our model. In this ... As is explained in §2, we use the concept of covering numbers to quantify the complexity of a class of ..... called structural risk minimization (SRM). Vapnik ...

  8. Analyzing the complexity of nanotechnology

    NARCIS (Netherlands)

    Vries, de M.J.; Schummer, J.; Baird, D.

    2006-01-01

    Nanotechnology is a highly complex technological development due to many uncertainties in our knowledge about it. The Dutch philosopher Herman Dooyeweerd has developed a conceptual framework that can be used (1) to analyze the complexity of technological developments and (2) to see how priorities

  9. Rhythmic complexity and predictive coding

    DEFF Research Database (Denmark)

    Vuust, Peter; Witek, Maria A G

    2014-01-01

    Musical rhythm, consisting of apparently abstract intervals of accented temporal events,has a remarkable capacity to move our minds and bodies. How does the cognitive systemenable our experiences of rhythmically complex music? In this paper, we describe somecommon forms of rhythmic complexity...

  10. Holographic complexity and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Barbón, José L.F. [Instituto de Física Teórica IFT UAM/CSIC,C/ Nicolás Cabrera 13, Campus Universidad Autónoma de Madrid,Madrid 28049 (Spain); Rabinovici, Eliezer [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2016-01-15

    We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.

  11. Innovation in a complex environment

    Directory of Open Access Journals (Sweden)

    René Pellissier

    2012-11-01

    Objectives: The study objectives were, firstly, to establish the determinants for complexity and how these can be addressed from a design point of view in order to ensure innovation success and, secondly, to determine how this changes innovation forms and applications. Method: Two approaches were offered to deal with a complex environment – one allowing for complexity for organisational innovation and the other introducing reductionism to minimise complexity. These approaches were examined in a qualitative study involving case studies, open-ended interviews and content analysis between seven developing economy (South African organisations and seven developed economy (US organisations. Results: This study presented a proposed framework for (organisational innovation in a complex environment versus a framework that minimises complexity. The comparative organisational analysis demonstrated the importance of initiating organisational innovation to address internal and external complexity, with the focus being on the leadership actions, their selected operating models and resultant organisational innovations designs, rather than on technological innovations. Conclusion: This study cautioned the preference for technological innovation within organisations and suggested alternative innovation forms (such as organisational and management innovation be used to remain competitive in a complex environment.

  12. Complexes and aggregates of chlorophylls

    NARCIS (Netherlands)

    Kooyman, R.P.H.

    1980-01-01

    Chlorophyll (Chl) molecules can form complexes in two important ways: by ligation at the magnesium atom and/or by hydrogen bonding at the keto- carbonyl group. Under certain conditions these processes may give rise to dimer formation. This thesis describes some properties of complexes and dimers of

  13. Thermogravimetric investigations of vanadium complexes

    International Nuclear Information System (INIS)

    Bechmann, W.; Uhlemann, E.; Ludwig, W.

    1987-01-01

    Extensive studies on oxovanadium(IV) and (V) complexes with bidentate chelating ligands include thermogravimetric investigations. TG, DTG, and DTA data provide additional facts to redox behaviour and stability of the complexes. These data also allow a critical appreciation of the given melting temperatures. (author)

  14. The Algebra of Complex Numbers.

    Science.gov (United States)

    LePage, Wilbur R.

    This programed text is an introduction to the algebra of complex numbers for engineering students, particularly because of its relevance to important problems of applications in electrical engineering. It is designed for a person who is well experienced with the algebra of real numbers and calculus, but who has no experience with complex number…

  15. Holographic complexity and spacetime singularities

    International Nuclear Information System (INIS)

    Barbón, José L.F.; Rabinovici, Eliezer

    2016-01-01

    We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.

  16. How to lead complex situations

    DEFF Research Database (Denmark)

    Hansen, Michael Pingel

    2013-01-01

    The military leader is experiencing increasingly more complex situations, whether it is as leader in a foreign combat environment or in the home-based public administration. Complex situations like these call for a special set of managerial responses and a special way of leading organisations...

  17. Servitization, Services and Managing Complexity

    DEFF Research Database (Denmark)

    Harjo, Ieva; Frandsen, Thomas; Hsuan, Juliana

    This paper explores how seemingly complex servitized solutions can become tradable in a customer–supplier relationship by objectification and abbreviation. The key argument is that the complexity of product-service solutions can be reduced by abbreviation of the reality in written form of contracts...

  18. The complex portal--an encyclopaedia of macromolecular complexes.

    Science.gov (United States)

    Meldal, Birgit H M; Forner-Martinez, Oscar; Costanzo, Maria C; Dana, Jose; Demeter, Janos; Dumousseau, Marine; Dwight, Selina S; Gaulton, Anna; Licata, Luana; Melidoni, Anna N; Ricard-Blum, Sylvie; Roechert, Bernd; Skyzypek, Marek S; Tiwari, Manu; Velankar, Sameer; Wong, Edith D; Hermjakob, Henning; Orchard, Sandra

    2015-01-01

    The IntAct molecular interaction database has created a new, free, open-source, manually curated resource, the Complex Portal (www.ebi.ac.uk/intact/complex), through which protein complexes from major model organisms are being collated and made available for search, viewing and download. It has been built in close collaboration with other bioinformatics services and populated with data from ChEMBL, MatrixDB, PDBe, Reactome and UniProtKB. Each entry contains information about the participating molecules (including small molecules and nucleic acids), their stoichiometry, topology and structural assembly. Complexes are annotated with details about their function, properties and complex-specific Gene Ontology (GO) terms. Consistent nomenclature is used throughout the resource with systematic names, recommended names and a list of synonyms all provided. The use of the Evidence Code Ontology allows us to indicate for which entries direct experimental evidence is available or if the complex has been inferred based on homology or orthology. The data are searchable using standard identifiers, such as UniProt, ChEBI and GO IDs, protein, gene and complex names or synonyms. This reference resource will be maintained and grow to encompass an increasing number of organisms. Input from groups and individuals with specific areas of expertise is welcome. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Epidemic modeling in complex realities.

    Science.gov (United States)

    Colizza, Vittoria; Barthélemy, Marc; Barrat, Alain; Vespignani, Alessandro

    2007-04-01

    In our global world, the increasing complexity of social relations and transport infrastructures are key factors in the spread of epidemics. In recent years, the increasing availability of computer power has enabled both to obtain reliable data allowing one to quantify the complexity of the networks on which epidemics may propagate and to envision computational tools able to tackle the analysis of such propagation phenomena. These advances have put in evidence the limits of homogeneous assumptions and simple spatial diffusion approaches, and stimulated the inclusion of complex features and heterogeneities relevant in the description of epidemic diffusion. In this paper, we review recent progresses that integrate complex systems and networks analysis with epidemic modelling and focus on the impact of the various complex features of real systems on the dynamics of epidemic spreading.

  20. COMPLEX TRAINING: A BRIEF REVIEW

    Directory of Open Access Journals (Sweden)

    William P. Ebben

    2002-06-01

    Full Text Available The effectiveness of plyometric training is well supported by research. Complex training has gained popularity as a training strategy combining weight training and plyometric training. Anecdotal reports recommend training in this fashion in order to improve muscular power and athletic performance. Recently, several studies have examined complex training. Despite the fact that questions remain about the potential effectiveness and implementation of this type of training, results of recent studies are useful in guiding practitioners in the development and implementation of complex training programs. In some cases, research suggests that complex training has an acute ergogenic effect on upper body power and the results of acute and chronic complex training include improved jumping performance. Improved performance may require three to four minutes rest between the weight training and plyometrics sets and the use of heavy weight training loads

  1. European Conference on Complex Systems

    CERN Document Server

    Pellegrini, Francesco; Caldarelli, Guido; Merelli, Emanuela

    2016-01-01

    This work contains a stringent selection of extended contributions presented at the meeting of 2014 and its satellite meetings, reflecting scope, diversity and richness of research areas in the field, both fundamental and applied. The ECCS meeting, held under the patronage of the Complex Systems Society, is an annual event that has become the leading European conference devoted to complexity science. It offers cutting edge research and unique opportunities to study novel scientific approaches in a multitude of application areas. ECCS'14, its eleventh occurrence, took place in Lucca, Italy. It gathered some 650 scholars representing a wide range of topics relating to complex systems research, with emphasis on interdisciplinary approaches. The editors are among the best specialists in the area. The book is of great interest to scientists, researchers and graduate students in complexity, complex systems and networks.

  2. Managing complexity insights, concepts, applications

    CERN Document Server

    Helbing, Dirk

    2007-01-01

    Each chapter in Managing Complexity focuses on analyzing real-world complex systems and transferring knowledge from the complex-systems sciences to applications in business, industry and society. The interdisciplinary contributions range from markets and production through logistics, traffic control, and critical infrastructures, up to network design, information systems, social conflicts and building consensus. They serve to raise readers' awareness concerning the often counter-intuitive behavior of complex systems and to help them integrate insights gained in complexity research into everyday planning, decision making, strategic optimization, and policy. Intended for a broad readership, the contributions have been kept largely non-technical and address a general, scientifically literate audience involved in corporate, academic, and public institutions.

  3. The Seis Lagos Carbonatite Complex

    International Nuclear Information System (INIS)

    Issler, R.S.; Silva, G.G. da.

    1980-01-01

    The Seis Lagos Carbonatite Complex located about 840 Km from Manaus, on the northwestern part of the Estado do Amazonas, Brazil is described. Geological reconnaissance mapping by Radam Project/DNPM, of the southwestern portion of the Guianes Craton, determined three circular features arranged in a north-south trend and outcroping as thick lateritic radioactive hills surrounded by gneisses and mignatites of the peneplained Guianense Complex. Results of core drilling samples analysis of the Seis Lagos Carbonatite Complex are compared with some igneous rocks and limestones of the world on the basis of abundance of their minor and trace elements. Log-log variation diagram of strontium and barium in carbonatite and limestone, exemplifield by South Africa and Angola carbonatites, are compared with the Seis Lagos Carbonatite Complex. The Seis Lagos Carbonatite Complex belongs to the siderite-soevite type. (E.G.) [pt

  4. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    analysts have difficulties grasping the dynamics implied by a process model. Recent empirical studies show that people make numerous errors when modeling complex business processes, e.g., about 20 percent of the EPCs in the SAP reference model have design flaws resulting in potential deadlocks, livelocks......, etc. It seems obvious that the complexity of the model contributes to design errors and a lack of understanding. It is not easy to measure complexity, however. This paper presents three complexity metrics that have been implemented in the process analysis tool ProM. The metrics are defined...... for a subclass of Petri nets named Workflow nets, but the results can easily be applied to other languages. To demonstrate the applicability of these metrics, we have applied our approach and tool to 262 relatively complex Protos models made in the context of various student projects. This allows us to validate...

  5. Innovation in a complex environment

    Directory of Open Access Journals (Sweden)

    René Pellissier

    2012-02-01

    Full Text Available Background: As our world becomes more global and competitive yet less predictable, the focus seems to be increasingly on looking to innovation activities to remain competitive. Although there is little doubt that a nation’s competitiveness is embedded in its innovativeness, the complex environment should not be ignored. Complexity is not accounted for in balance sheets or reported in reports; it becomes entrenched in every activity in the organisation. Innovation takes many forms and comes in different shapes.Objectives: The study objectives were, firstly, to establish the determinants for complexity and how these can be addressed from a design point of view in order to ensure innovation success and, secondly, to determine how this changes innovation forms and applications.Method: Two approaches were offered to deal with a complex environment – one allowing for complexity for organisational innovation and the other introducing reductionism to minimise complexity. These approaches were examined in a qualitative study involving case studies, open-ended interviews and content analysis between seven developing economy (South African organisations and seven developed economy (US organisations.Results: This study presented a proposed framework for (organisational innovation in a complex environment versus a framework that minimises complexity. The comparative organisational analysis demonstrated the importance of initiating organisational innovation to address internal and external complexity, with the focus being on the leadership actions, their selected operating models and resultant organisational innovations designs, rather than on technological innovations.Conclusion: This study cautioned the preference for technological innovation within organisations and suggested alternative innovation forms (such as organisational and management innovation be used to remain competitive in a complex environment. 

  6. Mapping on complex neutrosophic soft expert sets

    Science.gov (United States)

    Al-Quran, Ashraf; Hassan, Nasruddin

    2018-04-01

    We introduce the mapping on complex neutrosophic soft expert sets. Further, we investigated the basic operations and other related properties of complex neutrosophic soft expert image and complex neutrosophic soft expert inverse image of complex neutrosophic soft expert sets.

  7. Quantify the complexity of turbulence

    Science.gov (United States)

    Tao, Xingtian; Wu, Huixuan

    2017-11-01

    Many researchers have used Reynolds stress, power spectrum and Shannon entropy to characterize a turbulent flow, but few of them have measured the complexity of turbulence. Yet as this study shows, conventional turbulence statistics and Shannon entropy have limits when quantifying the flow complexity. Thus, it is necessary to introduce new complexity measures- such as topology complexity and excess information-to describe turbulence. Our test flow is a classic turbulent cylinder wake at Reynolds number 8100. Along the stream-wise direction, the flow becomes more isotropic and the magnitudes of normal Reynolds stresses decrease monotonically. These seem to indicate the flow dynamics becomes simpler downstream. However, the Shannon entropy keeps increasing along the flow direction and the dynamics seems to be more complex, because the large-scale vortices cascade to small eddies, the flow is less correlated and more unpredictable. In fact, these two contradictory observations partially describe the complexity of a turbulent wake. Our measurements (up to 40 diameters downstream the cylinder) show that the flow's degree-of-complexity actually increases firstly and then becomes a constant (or drops slightly) along the stream-wise direction. University of Kansas General Research Fund.

  8. Solution chemistry of lanthanide complexes

    International Nuclear Information System (INIS)

    Brittain, H.G.

    1979-01-01

    Intermolecular energy transfer from Tb 3+ to Eu 3+ , luminescence intensity measurements, potentiometric titrations, differential absorption spectroscopy, and spectroscopic titrations were all used to study the binding of lanthanide ions by serine and threonine. At low pH (3.0 to 6.0) the complexes are mononuclear and ligand is only weakly bound. In the pH interval of 6.0 to 8.5 stronger interaction takes place between the ligand and the metal (with possible coordination of the undissociated hydroxyl group), and self-association of complexes becomes important. Above pH 8.5, base hydrolysis of the complexes leads to highly associated species in solution and shortly above this pH an insoluble precipitate is formed. It was found that energy could be transferred from Tb 3+ to Eu 3+ more efficiently among complexes prepared from racemic ligands than in complexes made from resolved ligand, but this stereoselectivity was only observed at pH values greater than 6.5 and in solutions having a 1:10 ratio of metal-to-ligand. No stereoselectivity was found in solutions having 1:5 ratios, and this observation was explained by the existence of 1:2 metal-ligand complexes existing in solutions having the higher ratio of metal-to-ligand (only 1:1 complexes are then found at lower ratios of metal-to-ligand). (author)

  9. 3D complex: a structural classification of protein complexes.

    Directory of Open Access Journals (Sweden)

    Emmanuel D Levy

    2006-11-01

    Full Text Available Most of the proteins in a cell assemble into complexes to carry out their function. It is therefore crucial to understand the physicochemical properties as well as the evolution of interactions between proteins. The Protein Data Bank represents an important source of information for such studies, because more than half of the structures are homo- or heteromeric protein complexes. Here we propose the first hierarchical classification of whole protein complexes of known 3-D structure, based on representing their fundamental structural features as a graph. This classification provides the first overview of all the complexes in the Protein Data Bank and allows nonredundant sets to be derived at different levels of detail. This reveals that between one-half and two-thirds of known structures are multimeric, depending on the level of redundancy accepted. We also analyse the structures in terms of the topological arrangement of their subunits and find that they form a small number of arrangements compared with all theoretically possible ones. This is because most complexes contain four subunits or less, and the large majority are homomeric. In addition, there is a strong tendency for symmetry in complexes, even for heteromeric complexes. Finally, through comparison of Biological Units in the Protein Data Bank with the Protein Quaternary Structure database, we identified many possible errors in quaternary structure assignments. Our classification, available as a database and Web server at http://www.3Dcomplex.org, will be a starting point for future work aimed at understanding the structure and evolution of protein complexes.

  10. Actinide cation-cation complexes

    International Nuclear Information System (INIS)

    Stoyer, N.J.; Seaborg, G.T.

    1994-12-01

    The +5 oxidation state of U, Np, Pu, and Am is a linear dioxo cation (AnO 2 + ) with a formal charge of +1. These cations form complexes with a variety of other cations, including actinide cations. Other oxidation states of actinides do not form these cation-cation complexes with any cation other than AnO 2 + ; therefore, cation-cation complexes indicate something unique about AnO 2 + cations compared to actinide cations in general. The first cation-cation complex, NpO 2 + ·UO 2 2+ , was reported by Sullivan, Hindman, and Zielen in 1961. Of the four actinides that form AnO 2 + species, the cation-cation complexes of NpO 2 + have been studied most extensively while the other actinides have not. The only PuO 2 + cation-cation complexes that have been studied are with Fe 3+ and Cr 3+ and neither one has had its equilibrium constant measured. Actinides have small molar absorptivities and cation-cation complexes have small equilibrium constants; therefore, to overcome these obstacles a sensitive technique is required. Spectroscopic techniques are used most often to study cation-cation complexes. Laser-Induced Photacoustic Spectroscopy equilibrium constants for the complexes NpO 2 + ·UO 2 2+ , NpO 2 + ·Th 4+ , PuO 2 + ·UO 2 2+ , and PuO 2 + ·Th 4+ at an ionic strength of 6 M using LIPAS are 2.4 ± 0.2, 1.8 ± 0.9, 2.2 ± 1.5, and ∼0.8 M -1

  11. Neurosurgical implications of Carney complex.

    Science.gov (United States)

    Watson, J C; Stratakis, C A; Bryant-Greenwood, P K; Koch, C A; Kirschner, L S; Nguyen, T; Carney, J A; Oldfield, E H

    2000-03-01

    The authors present their neurosurgical experience with Carney complex. Carney complex, characterized by spotty skin pigmentation, cardiac myxomas, primary pigmented nodular adrenocortical disease, pituitary tumors, and nerve sheath tumors (NSTs), is a recently described, rare, autosomal-dominant familial syndrome that is relatively unknown to neurosurgeons. Neurosurgery is required to treat pituitary adenomas and a rare NST, the psammomatous melanotic schwannoma (PMS), in patients with Carney complex. Cushing's syndrome, a common component of the complex, is caused by primary pigmented nodular adrenocortical disease and is not secondary to an adrenocorticotropic hormone-secreting pituitary adenoma. The authors reviewed 14 cases of Carney complex, five from the literature and nine from their own experience. Of the 14 pituitary adenomas recognized in association with Carney complex, 12 developed growth hormone (GH) hypersecretion (producing gigantism in two patients and acromegaly in 10), and results of immunohistochemical studies in one of the other two were positive for GH. The association of PMSs with Carney complex was established in 1990. Of the reported tumors, 28% were associated with spinal nerve sheaths. The spinal tumors occurred in adults (mean age 32 years, range 18-49 years) who presented with pain and radiculopathy. These NSTs may be malignant (10%) and, as with the cardiac myxomas, are associated with significant rates of morbidity and mortality. Because of the surgical comorbidity associated with cardiac myxoma and/or Cushing's syndrome, recognition of Carney complex has important implications for perisurgical patient management and family screening. Study of the genetics of Carney complex and of the biological abnormalities associated with the tumors may provide insight into the general pathobiological abnormalities associated with the tumors may provide insight into the general pathobiological features of pituitary adenomas and NSTs.

  12. Persistent homology of complex networks

    International Nuclear Information System (INIS)

    Horak, Danijela; Maletić, Slobodan; Rajković, Milan

    2009-01-01

    Long-lived topological features are distinguished from short-lived ones (considered as topological noise) in simplicial complexes constructed from complex networks. A new topological invariant, persistent homology, is determined and presented as a parameterized version of a Betti number. Complex networks with distinct degree distributions exhibit distinct persistent topological features. Persistent topological attributes, shown to be related to the robust quality of networks, also reflect the deficiency in certain connectivity properties of networks. Random networks, networks with exponential connectivity distribution and scale-free networks were considered for homological persistency analysis

  13. Implicit computational complexity and compilers

    DEFF Research Database (Denmark)

    Rubiano, Thomas

    Complexity theory helps us predict and control resources, usually time and space, consumed by programs. Static analysis on specific syntactic criterion allows us to categorize some programs. A common approach is to observe the program’s data’s behavior. For instance, the detection of non...... evolution and a lot of research came from this theory. Until now, these implicit complexity theories were essentially applied on more or less toy languages. This thesis applies implicit computational complexity methods into “real life” programs by manipulating intermediate representation languages...

  14. Interdisciplinary conflict and organizational complexity.

    Science.gov (United States)

    Guy, M E

    1986-01-01

    Most people think that conflict among the professional staff is inevitable and results from each profession's unique set of values. Each profession then defends itself by claiming its own turf. This article demonstrates that organizational complexity, not professional territorialism, influences the amount of intraorganizational conflict. In a comparison of two psychiatric hospitals, this study shows that there is not necessarily greater conflict across professions than within professions. However, there is a significantly greater amount of conflict among staff at a structurally more complex hospital than at a less-complex hospital, regardless of profession. Implications for management are discussed.

  15. Management of complex dynamical systems

    Science.gov (United States)

    MacKay, R. S.

    2018-02-01

    Complex dynamical systems are systems with many interdependent components which evolve in time. One might wish to control their trajectories, but a more practical alternative is to control just their statistical behaviour. In many contexts this would be both sufficient and a more realistic goal, e.g. climate and socio-economic systems. I refer to it as ‘management’ of complex dynamical systems. In this paper, some mathematics for management of complex dynamical systems is developed in the weakly dependent regime, and questions are posed for the strongly dependent regime.

  16. Advances in computational complexity theory

    CERN Document Server

    Cai, Jin-Yi

    1993-01-01

    This collection of recent papers on computational complexity theory grew out of activities during a special year at DIMACS. With contributions by some of the leading experts in the field, this book is of lasting value in this fast-moving field, providing expositions not found elsewhere. Although aimed primarily at researchers in complexity theory and graduate students in mathematics or computer science, the book is accessible to anyone with an undergraduate education in mathematics or computer science. By touching on some of the major topics in complexity theory, this book sheds light on this burgeoning area of research.

  17. Complexity in physics and technology

    CERN Document Server

    Garrido, Manuel S

    1992-01-01

    A system is loosely defined as complex if it is composed of a large number of elements, interacting with each other, and the emergent global dynamics is qualitatively different from the dynamics of each one of the parts. The global dynamics may be either ordered or chaotic and among the most interesting emergent global properties are those of learning and adaptation.Complex systems, in the above sense, appear in many fields ranging from physics and technology to life and social sciences. Research in complex systems involves therefore a wide range of topics, studied in seemingly disparate field

  18. Scattering methods in complex fluids

    CERN Document Server

    Chen, Sow-Hsin

    2015-01-01

    Summarising recent research on the physics of complex liquids, this in-depth analysis examines the topic of complex liquids from a modern perspective, addressing experimental, computational and theoretical aspects of the field. Selecting only the most interesting contemporary developments in this rich field of research, the authors present multiple examples including aggregation, gel formation and glass transition, in systems undergoing percolation, at criticality, or in supercooled states. Connecting experiments and simulation with key theoretical principles, and covering numerous systems including micelles, micro-emulsions, biological systems, and cement pastes, this unique text is an invaluable resource for graduate students and researchers looking to explore and understand the expanding field of complex fluids.

  19. The Complexity of Indirect Translation

    DEFF Research Database (Denmark)

    Wenjie, L. I.

    2017-01-01

    its complex nature, and thus determined that many facets of ITr remain to be studied. The present article will try to encompass the complexity of ITr by looking into the reasons for translating indirectly, the challenge of finding out mediating texts (MTs), indirectness in both translation...... of which have been translated and interpreted indirectly through major languages like English, will be employed as examples. Hopefully, this study will offer more insights into the nature of translation as a social activity and raise further interests in studying translation as a complex phenomenon....

  20. Theory of complex potential scattering

    International Nuclear Information System (INIS)

    Kok, L.P.; Haeringen, H.v.

    1981-01-01

    We study the effect of the addition of a complex potential lambdaV/sub sep/ to an arbitrary Schroedinger operator H = H 0 +V on the singularities of the S matrix, as a function of lambda. Here V/sub sep/ is a separable interaction, and lambda is a complex coupling parameter. The paths of these singularities are determined to a great extent by certain saddle points in the momentum (or energy) plane. We explain certain critical phenomena recently reported in the literature. Associated with these saddles are branch-type singularities in the complex lambda plane, which are dynamical in origin. Some examples are discussed in detail

  1. Global aspects of complex geometry

    CERN Document Server

    Catanese, Fabrizio; Huckleberry, Alan T

    2006-01-01

    Present an overview of developments in Complex Geometry. This book covers topics that range from curve and surface theory through special varieties in higher dimensions, moduli theory, Kahler geometry, and group actions to Hodge theory and characteristic p-geometry.

  2. Complex Topographic Feature Ontology Patterns

    Science.gov (United States)

    Varanka, Dalia E.; Jerris, Thomas J.

    2015-01-01

    Semantic ontologies are examined as effective data models for the representation of complex topographic feature types. Complex feature types are viewed as integrated relations between basic features for a basic purpose. In the context of topographic science, such component assemblages are supported by resource systems and found on the local landscape. Ontologies are organized within six thematic modules of a domain ontology called Topography that includes within its sphere basic feature types, resource systems, and landscape types. Context is constructed not only as a spatial and temporal setting, but a setting also based on environmental processes. Types of spatial relations that exist between components include location, generative processes, and description. An example is offered in a complex feature type ‘mine.’ The identification and extraction of complex feature types are an area for future research.

  3. Complexity for survival of livings

    International Nuclear Information System (INIS)

    Zak, Michail

    2007-01-01

    A connection between survivability of livings and complexity of their behavior is established. New physical paradigms-exchange of information via reflections, and chain of abstractions-explaining and describing progressive evolution of complexity in living (active) systems are introduced. A biological origin of these paradigms is associated with a recently discovered mirror neuron that is able to learn by imitation. As a result, an active element possesses the self-nonself images and interacts with them creating the world of mental dynamics. Three fundamental types of complexity of mental dynamics that contribute to survivability are identified. Mathematical model of the corresponding active systems is described by coupled motor-mental dynamics represented by Langevin and Fokker-Planck equations, respectively, while the progressive evolution of complexity is provided by nonlinear evolution of probability density. Application of the proposed formalism to modeling common-sense-based decision-making process is discussed

  4. Complexity for survival of livings

    Energy Technology Data Exchange (ETDEWEB)

    Zak, Michail [Jet Propulsion Laboratory, California Institute of Technology, Advance Computing Algorithms and IVHM Group, Pasadena, CA 91109 (United States)]. E-mail: Michail.Zak@jpl.nasa.gov

    2007-05-15

    A connection between survivability of livings and complexity of their behavior is established. New physical paradigms-exchange of information via reflections, and chain of abstractions-explaining and describing progressive evolution of complexity in living (active) systems are introduced. A biological origin of these paradigms is associated with a recently discovered mirror neuron that is able to learn by imitation. As a result, an active element possesses the self-nonself images and interacts with them creating the world of mental dynamics. Three fundamental types of complexity of mental dynamics that contribute to survivability are identified. Mathematical model of the corresponding active systems is described by coupled motor-mental dynamics represented by Langevin and Fokker-Planck equations, respectively, while the progressive evolution of complexity is provided by nonlinear evolution of probability density. Application of the proposed formalism to modeling common-sense-based decision-making process is discussed.

  5. Neural complexity, dissociation, and schizophrenia

    Czech Academy of Sciences Publication Activity Database

    Bob, P.; Šusta, M.; Chládek, Jan; Glaslová, K.; Fedor-Ferybergh, P.

    2007-01-01

    Roč. 13, č. 10 (2007), HY1-5 ISSN 1234-1010 Institutional research plan: CEZ:AV0Z20650511 Keywords : neural complexity * dissociation * schizophrenia Subject RIV: FH - Neurology Impact factor: 1.607, year: 2007

  6. Machining of Complex Sculptured Surfaces

    CERN Document Server

    2012-01-01

    The machining of complex sculptured surfaces is a global technological topic in modern manufacturing with relevance in both industrialized and emerging in countries particularly within the moulds and dies sector whose applications include highly technological industries such as the automotive and aircraft industry. Machining of Complex Sculptured Surfaces considers new approaches to the manufacture of moulds and dies within these industries. The traditional technology employed in the manufacture of moulds and dies combined conventional milling and electro-discharge machining (EDM) but this has been replaced with  high-speed milling (HSM) which has been applied in roughing, semi-finishing and finishing of moulds and dies with great success. Machining of Complex Sculptured Surfaces provides recent information on machining of complex sculptured surfaces including modern CAM systems and process planning for three and five axis machining as well as explanations of the advantages of HSM over traditional methods ra...

  7. Genetics Home Reference: Carney complex

    Science.gov (United States)

    ... cortisol (hypercortisolism) can lead to the development of Cushing syndrome. This syndrome causes weight gain in the face ... Institute of Diabetes and Digestive and Kidney Diseases: Cushing's Syndrome Educational Resources (6 links) Disease InfoSearch: Carney Complex ...

  8. Mathematicians, Attributional Complexity, and Gender

    Science.gov (United States)

    Stalder, Daniel R.

    Given indirect indications in sex role and soda! psychology research that mathematical-deductive reasoning may negatively relate to social acuity, Study 1 investigated whether mathematicians were less attributionally complex than nonmathematicians. Study 1 administered the Attributional Complexity Scale, a measure of social acuity, to female and male faculty members and graduate students in four Midwestern schools. Atlrihutional complexity (AC) is the ability and motivation to give complex explanations for behavior. Study 1 found a significant interaction between field and gender. Only among women did mathematicians score lower on AC. In addition, an established gender difference in AC (that women score higher than men) was present only among nonmathematicians. Studies 2 and 3 offered some preliminary support for the possibility that it is generally female students who score tow on AC who aspire to he mathematicians and for the underlying view that female students' perceived similarity to mathematicians can influence their vocational choices.

  9. Making the Tent Function Complex

    Science.gov (United States)

    Sprows, David J.

    2010-01-01

    This note can be used to illustrate to the student such concepts as periodicity in the complex plane. The basic construction makes use of the Tent function which requires only that the student have some working knowledge of binary arithmetic.

  10. TETRACYANONICKELATE(II) PYRIDAZINE COMPLEXES

    African Journals Online (AJOL)

    B. S. Chandravanshi

    and therefore they have been attracting increasing attention from scientists [1]. .... in the spectra of the complexes studied are listed in Table 1, together with free ..... Raman spectra were recorded at Anadolu University, Department of Physics.

  11. Complex Hydrides for Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, Darlene; Hampton, Michael

    2003-03-10

    This report describes research into the use of complex hydrides for hydrogen storage. The synthesis of a number of alanates, (AIH4) compounds, was investigated. Both wet chemical and mechano-chemical methods were studied.

  12. Disordered Plamonics and Complex Metamaterials

    KAUST Repository

    Gongora, J. S. Totero

    2017-01-01

    Complex systems are ensembles of interconnected elements where mutual interaction and an optimized amount of disorder produce advanced functionalities. These systems are abundant in our daily experience: typical examples are the brain, biological

  13. Anomaly Detection for Complex Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — In performance maintenance in large, complex systems, sensor information from sub-components tends to be readily available, and can be used to make predictions about...

  14. Complex Hybrid Inflation and Baryogenesis

    OpenAIRE

    Delepine, David; Martinez, Carlos; Urena-Lopez, L. Arturo

    2006-01-01

    We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated to the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vev of the waterfall field, which is well constrained by diverse cosmological observations.

  15. Complex Hybrid Inflation and Baryogenesis

    International Nuclear Information System (INIS)

    Delepine, David; Martinez, Carlos; Urena-Lopez, L. Arturo

    2007-01-01

    We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated with the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vacuum expectation value of the waterfall field, which is well constrained by diverse cosmological observations

  16. Complex hybrid inflation and baryogenesis.

    Science.gov (United States)

    Delepine, David; Martínez, Carlos; Ureña-López, L Arturo

    2007-04-20

    We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated with the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vacuum expectation value of the waterfall field, which is well constrained by diverse cosmological observations.

  17. Symbolic Dynamics and Grammatical Complexity

    Science.gov (United States)

    Hao, Bai-Lin; Zheng, Wei-Mou

    The following sections are included: * Formal Languages and Their Complexity * Formal Language * Chomsky Hierarchy of Grammatical Complexity * The L-System * Regular Language and Finite Automaton * Finite Automaton * Regular Language * Stefan Matrix as Transfer Function for Automaton * Beyond Regular Languages * Feigenbaum and Generalized Feigenbaum Limiting Sets * Even and Odd Fibonacci Sequences * Odd Maximal Primitive Prefixes and Kneading Map * Even Maximal Primitive Prefixes and Distinct Excluded Blocks * Summary of Results

  18. Decentralized control of complex systems

    CERN Document Server

    Siljak, Dragoslav D

    2011-01-01

    Complex systems require fast control action in response to local input, and perturbations dictate the use of decentralized information and control structures. This much-cited reference book explores the approaches to synthesizing control laws under decentralized information structure constraints.Starting with a graph-theoretic framework for structural modeling of complex systems, the text presents results related to robust stabilization via decentralized state feedback. Subsequent chapters explore optimization, output feedback, the manipulative power of graphs, overlapping decompositions and t

  19. Statistical mechanics of complex networks

    CERN Document Server

    Rubi, Miguel; Diaz-Guilera, Albert

    2003-01-01

    Networks can provide a useful model and graphic image useful for the description of a wide variety of web-like structures in the physical and man-made realms, e.g. protein networks, food webs and the Internet. The contributions gathered in the present volume provide both an introduction to, and an overview of, the multifaceted phenomenology of complex networks. Statistical Mechanics of Complex Networks also provides a state-of-the-art picture of current theoretical methods and approaches.

  20. Recent developments in complex scaling

    International Nuclear Information System (INIS)

    Rescigno, T.N.

    1980-01-01

    Some recent developments in the use of complex basis function techniques to study resonance as well as certain types of non-resonant, scattering phenomena are discussed. Complex scaling techniques and other closely related methods have continued to attract the attention of computational physicists and chemists and have now reached a point of development where meaningful calculations on many-electron atoms and molecules are beginning to appear feasible

  1. Substitution reactions of technetium complexes

    International Nuclear Information System (INIS)

    Omori, T.

    1997-01-01

    Substitution reactions of a series of technetium complexes are considered in comparison with corresponding reactions of rhenium. Rhenium and technetium complexes are rather inert in substitution reactions, the latter are characterized by greater rate constants when they proceed according to dissociative mechanism. In rare cases when k Tc /k Re id little it is assumed that the reaction proceeds according to the associative mechanism. (author)

  2. Determinants of Hospital Casemix Complexity

    Science.gov (United States)

    Becker, Edmund R.; Steinwald, Bruce

    1981-01-01

    Using the Commission on Professional and Hospital Activities' Resource Need Index as a measure of casemix complexity, this paper examines the relative contributions of teaching commitment and other hospital characteristics, hospital service and insurer distributions, and area characteristics to variations in casemix complexity. The empirical estimates indicate that all three types of independent variables have a substantial influence. These results are discussed in light of recent casemix research as well as current policy implications. PMID:6799430

  3. Strategic Complexity and Global Expansion

    DEFF Research Database (Denmark)

    Oladottir, Asta Dis; Hobdari, Bersant; Papanastassiou, Marina

    2012-01-01

    The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish....... The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness....

  4. Complex ray analysis for plasmas

    International Nuclear Information System (INIS)

    Connor, K.A.

    1980-01-01

    An extension of ray tracing techniques is considered for a variety of cases in which the dispersion relation of the plasma medium is complex. The ray trajectories are permitted to begin and/or at least travel through complex space-time; the wave propagation process so characterized becomes significant only where the rays intersect real space-time. It is found that rules and guidelines can be established for limited application of this idea

  5. Linearization Method and Linear Complexity

    Science.gov (United States)

    Tanaka, Hidema

    We focus on the relationship between the linearization method and linear complexity and show that the linearization method is another effective technique for calculating linear complexity. We analyze its effectiveness by comparing with the logic circuit method. We compare the relevant conditions and necessary computational cost with those of the Berlekamp-Massey algorithm and the Games-Chan algorithm. The significant property of a linearization method is that it needs no output sequence from a pseudo-random number generator (PRNG) because it calculates linear complexity using the algebraic expression of its algorithm. When a PRNG has n [bit] stages (registers or internal states), the necessary computational cost is smaller than O(2n). On the other hand, the Berlekamp-Massey algorithm needs O(N2) where N(≅2n) denotes period. Since existing methods calculate using the output sequence, an initial value of PRNG influences a resultant value of linear complexity. Therefore, a linear complexity is generally given as an estimate value. On the other hand, a linearization method calculates from an algorithm of PRNG, it can determine the lower bound of linear complexity.

  6. Analysis of nanoparticle biomolecule complexes.

    Science.gov (United States)

    Gunnarsson, Stefán B; Bernfur, Katja; Mikkelsen, Anders; Cedervall, Tommy

    2018-03-01

    Nanoparticles exposed to biological fluids adsorb biomolecules on their surface forming a biomolecular corona. This corona determines, on a molecular level, the interactions and impact the newly formed complex has on cells and organisms. The corona formation as well as the physiological and toxicological relevance are commonly investigated. However, an acknowledged but rarely addressed problem in many fields of nanobiotechnology is aggregation and broadened size distribution of nanoparticles following their interactions with the molecules of biological fluids. In blood serum, TiO 2 nanoparticles form complexes with a size distribution from 30 nm to more than 500 nm. In this study we have separated these complexes, with good resolution, using preparative centrifugation in a sucrose gradient. Two main apparent size populations were obtained, a fast sedimenting population of complexes that formed a pellet in the preparative centrifugation tube, and a slow sedimenting complex population still suspended in the gradient after centrifugation. Concentration and surface area dependent differences are found in the biomolecular corona between the slow and fast sedimenting fractions. There are more immunoglobulins, lipid binding proteins, and lipid-rich complexes at higher serum concentrations. Sedimentation rate and the biomolecular corona are important factors for evaluating any experiment including nanoparticle exposure. Our results show that traditional description of nanoparticles in biological fluids is an oversimplification and that more thorough characterisations are needed.

  7. Complexity

    Indian Academy of Sciences (India)

    Rahul Pandit

    2008-10-31

    Oct 31, 2008 ... Centre for Condensed Matter Theory. Department of Physics. Indian Institute ... Interactions between a system's components are important role. ... Scale-free networks in, say, social networks or the world-wide web. ▻ A system ...

  8. Coopetition and Complexity : Exploring a Coopetitive Relationship with Complexity

    OpenAIRE

    Wennberg, Andreas; Persson, Emil

    2011-01-01

    Cooperation have in previous research been seen as a negative impact on competition and  vice versa. This thesis is building on a concept called coopetition in which cooperation and  competition is studied simultaneously. Coopetition have been studied in terms of the level of  cooperation and competition. However, we found a possible link between coopetition and  complexity in previous literature. Thus, the purpose of this study is to explore whether  complexity can develop an understanding f...

  9. The fifth adaptor protein complex.

    Directory of Open Access Journals (Sweden)

    Jennifer Hirst

    2011-10-01

    Full Text Available Adaptor protein (AP complexes sort cargo into vesicles for transport from one membrane compartment of the cell to another. Four distinct AP complexes have been identified, which are present in most eukaryotes. We report the existence of a fifth AP complex, AP-5. Tagged AP-5 localises to a late endosomal compartment in HeLa cells. AP-5 does not associate with clathrin and is insensitive to brefeldin A. Knocking down AP-5 subunits interferes with the trafficking of the cation-independent mannose 6-phosphate receptor and causes the cell to form swollen endosomal structures with emanating tubules. AP-5 subunits can be found in all five eukaryotic supergroups, but they have been co-ordinately lost in many organisms. Concatenated phylogenetic analysis provides robust resolution, for the first time, into the evolutionary order of emergence of the adaptor subunit families, showing AP-3 as the basal complex, followed by AP-5, AP-4, and AP-1 and AP-2. Thus, AP-5 is an evolutionarily ancient complex, which is involved in endosomal sorting, and which has links with hereditary spastic paraplegia.

  10. Complexity in White Noise Analysis

    Science.gov (United States)

    Hida, Takeyuki

    We restrict our attention to random complex systems and discuss degree their degree of complexity based on a white noise. The white noise is realized as the time derivative of a Brownian motion B(t), and denoted by Ḃ(t). The collection {Ḃ(t)}, is a system of idealized elementary variables and at the same time the system is a stochastic representation of the time t, in other words it is time-oriented. Having expressed the given evolutional random phenomena in question in terms of the Ḃ(t), we introduce the notion of spectral multiplicity, which describes how much the phenomena are complex. The multiplicity is the number of cyclic subspaces that are spanned by the given random phenomena. Each cyclic subspace has further structure. Typical property is multiple Markov property, although this property appears only particular cases. As a related property, in fact as a characteristic of a complex system, one can speak of the time reversibility and irreversibility of certain random phenomena in terms of the white noise. We expect an irreversible random complex system may be decomposed into reversible systems.

  11. Separations in Communication Complexity Using Cheat Sheets and Information Complexity

    NARCIS (Netherlands)

    A. Anshu (Anurag); A. Belovs (Aleksandr); S. Ben-David (Shalev); M. Goos (Mika); R. Jain (Rahul); R. Kothari (Robin); T. J. Lee (Troy); M. Santha (Miklos)

    2016-01-01

    textabstractWhile exponential separations are known between quantum and randomized communication complexity for partial functions (Raz, STOC 1999), the best known separation between these measures for a total function is quadratic, witnessed by the disjointness function. We give the first

  12. Complex Solutions for Complex Needs: Towards Holistic and Collaborative Practice

    Science.gov (United States)

    Beadle, Sally

    2009-01-01

    While the need for holistic health and social service responses is increasingly being articulated in Australia, the discussion is not always matched by improvements in service delivery. This project looked at one service setting where youth workers were encouraged to take a holistic approach to their clients' often-complex needs. Interviews with…

  13. Hyperbolic isometries of systolic complexes

    DEFF Research Database (Denmark)

    Prytula, Tomasz Pawel

    The main topics of this thesis are the geometric features of systolic complexesarising from the actions of hyperbolic isometries. The thesis consists ofan introduction followed by two articles.Given a hyperbolic isometry h of a systolic complex X, our central theme isto study the minimal displace......The main topics of this thesis are the geometric features of systolic complexesarising from the actions of hyperbolic isometries. The thesis consists ofan introduction followed by two articles.Given a hyperbolic isometry h of a systolic complex X, our central theme isto study the minimal...... algebraic-topological features of systolic groups. In addition, we provide newexamples of systolic groups.In the first article we show that the minimal displacement set of a hyperbolicisometry of a systolic complex is quasi-isometric to the product of a tree andthe real line. We use this theorem...

  14. The new science of complexity

    Directory of Open Access Journals (Sweden)

    Joseph L. McCauley

    1997-01-01

    Full Text Available Deterministic chaos, and even maximum computational complexity, have been discovered within Newtonian dynamics. Economists assume that prices and price changes can also obey abstract mathematical laws of motion. Sociologists and other postmodernists advertise that physics and chemistry have outgrown their former limitations, that chaos and complexity provide new holistic paradigms for science, and that the boundaries between the hard and the soft sciences, once impenetrable, have disappeared like the Berlin Wall. Three hundred years after the deaths of Galileo, Descartes, and Kepler, and the birth of Newton, reductionism appears to be on the decline, with holistic approaches to science on the upswing. We therefore examine the evidence that dynamical laws of motion may be discovered from empirical studies of chaotic or complex phenomena, and also review the foundation of reductionism in invariance principles.

  15. Complexity hints for economic policy

    CERN Document Server

    Salzano, Massimo

    2007-01-01

    This volume extends the complexity approach to economics. This complexity approach is not a completely new way of doing economics, and that it is a replacement for existing economics, but rather the integration of some new analytic and computational techniques into economists’ bag of tools. It provides some alternative pattern generators, which can supplement existing approaches by providing an alternative way of finding patterns than be obtained by the traditional scientific approach. On this new kind of policy hints can be obtained. The reason why the complexity approach is taking hold now in economics is because the computing technology has advanced. This advance allows consideration of analytical systems that could not previously be considered by economists. Consideration of these systems suggested that the results of the "control-based" models might not extend easily to more complicated systems, and that we now have a method—piggybacking computer assisted analysis onto analytic methods—to start gen...

  16. Carney complex review: Genetic features.

    Science.gov (United States)

    Bosco Schamun, María Belén; Correa, Ricardo; Graffigna, Patricia; de Miguel, Valeria; Fainstein Day, Patricia

    2018-01-01

    Carney complex is a multiple neoplasia syndrome having endocrine and non-endocrine manifestations. Diagnostic criteria include myxoma, lentigines, and primary pigmented nodular adrenocortical disease, amongst other signs/symptoms. In most cases it is an autosomal dominant disease, and diagnosis therefore requires study and follow-up of the family members. Inactivating mutations of the PRKAR1A gene were identified as the main cause of the disease, although since 2015 other disease-related genes, including PRKACA and PRKACB activating mutations, have also been related with Carney complex. This review will address the genetic aspects related to Carney complex. Copyright © 2017 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Simulating social complexity a handbook

    CERN Document Server

    Meyer, Ruth

    2013-01-01

    Social systems are among the most complex known. This poses particular problems for those who wish to understand them. The complexity often makes analytic approaches infeasible and natural language approaches inadequate for relating intricate cause and effect. However, individual- and agent-based computational approaches hold out the possibility of new and deeper understanding of such systems.  Simulating Social Complexity examines all aspects of using agent- or individual-based simulation. This approach represents systems as individual elements having each their own set of differing states and internal processes. The interactions between elements in the simulation represent interactions in the target systems. What makes these elements "social" is that they are usefully interpretable as interacting elements of an observed society. In this, the focus is on human society, but can be extended to include social animals or artificial agents where such work enhances our understanding of human society.  The phenom...

  18. Complexity, cognition and the city

    CERN Document Server

    Portugali, Juval

    2011-01-01

    Complexity, Cognition and the City aims at a deeper understanding of urbanism, while invoking, on an equal footing, the contributions both the hard and soft sciences have made, and are still making, when grappling with the many issues and facets of regional planning and dynamics. In this work, the author goes beyond merely seeing the city as a self-organized, emerging pattern of some collective interaction between many stylized urban "agents" – he makes the crucial step of attributing cognition to his agents and thus raises, for the first time, the question on how to deal with a complex system composed of many interacting complex agents in clearly defined settings. Accordingly, the author eventually addresses issues of practical relevance for urban planners and decision makers. The book unfolds its message in a largely nontechnical manner, so as to provide a broad interdisciplinary readership with insights, ideas, and other stimuli to encourage further research – with the twofold aim of further pushing ba...

  19. Metal complexes with 5-aminotetrazole

    International Nuclear Information System (INIS)

    Lavrenova, L.G.; Larionov, S.V.; Grankina, Z.A.; Ikorskij, V.N.

    1983-01-01

    Nitrate and chloride complexes of Co(2), Ni(2), Cu(2), Cd(2), Hg(2), Pb(2) with 5 aminotetrazole (ATE) and compoUnds Zn(ATE') 2 and Cd(ATEE') 2 , where ATE' is a 5 aminotetrazole ano /nion. On the base of spectroscopic data (spectrophotometry, IR- spectra, EPR and magnetic measurements assumptions on M(2) coordination in complexes are made. Most probably ATE is a bridge ligand which is joined by two nitrogen atoms to various M(2) ions. In Co(2), Ni(2) and Cu(ATE) 3 -Cl 2 compounds the metal has a distorted actahedral coordination and forms MN 6 unit, which suggests the interaction of metal ions with ATE nitrogen atoms along the Z-axis. In the Cu(ATE) 2 (NO 3 ) 2 octahedral complex the CuN 4 O 2 coordination unit is realized at the expense of participation of nitratogroups in coordination

  20. Characterising Complex Enzyme Reaction Data.

    Directory of Open Access Journals (Sweden)

    Handan Melike Dönertaş

    Full Text Available The relationship between enzyme-catalysed reactions and the Enzyme Commission (EC number, the widely accepted classification scheme used to characterise enzyme activity, is complex and with the rapid increase in our knowledge of the reactions catalysed by enzymes needs revisiting. We present a manual and computational analysis to investigate this complexity and found that almost one-third of all known EC numbers are linked to more than one reaction in the secondary reaction databases (e.g., KEGG. Although this complexity is often resolved by defining generic, alternative and partial reactions, we have also found individual EC numbers with more than one reaction catalysing different types of bond changes. This analysis adds a new dimension to our understanding of enzyme function and might be useful for the accurate annotation of the function of enzymes and to study the changes in enzyme function during evolution.

  1. 1989 lectures in complex systems

    International Nuclear Information System (INIS)

    Jen, E.

    1990-01-01

    This report contains papers on the following topics: Lectures on a Theory of Computation and Complexity over the Reals; Algorithmic Information Content, Church-Turing Thesis, Physical Entroph, and Maxwell's Demon; Physical Measures of Complexity; An Introduction to Chaos and Prediction; Hamiltonian Chaos in Nonlinear Polarized Optical Beam; Chemical Oscillators and Nonlinear Chemical Dynamics; Isotropic Navier-Stokes Turbulence. I. Qualitative Features and Basic Equations; Isotropic Navier-Stokes Turbulence. II. Statistical Approximation Methods; Lattice Gases; Data-Parallel Computation and the Connection Machine; Preimages and Forecasting for Cellular Automata; Lattice-Gas Models for Multiphase Flows and Magnetohydrodynamics; Probabilistic Cellular Automata: Some Statistical Mechanical Considerations; Complexity Due to Disorder and Frustration; Self-Organization by Simulated Evolution; Theoretical Immunology; Morphogenesis by Cell Intercalation; and Theoretical Physics Meets Experimental Neurobiology

  2. Complexation thermodynamics of modified cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, Rene

    2014-01-01

    Inclusion complexes between two bile salts and a range of differently methylated β-cyclodextrins were studied in an attempt to rationalize the complexation thermodynamics of modified cyclodextrins. Calorimetric titrations at a range of temperatures provided precise values of the enthalpies (ΔH......°), entropies (ΔS°), and heat capacities (ΔCp) of complexation, while molecular dynamics simulations assisted the interpretation of the obtained thermodynamic parameters. As previously observed for several types of modified cyclodextrins, the substituents at the rims of the cyclodextrin induced large changes......° and then a strong decrease when the degree of substitution exceeded some threshold. Exactly the same trend was observed for ΔCp. The dehydration of nonpolar surface, as quantified by the simulations, can to a large extent explain the variation in the thermodynamic parameters. The methyl substituents form additional...

  3. Complex proofs of real theorems

    CERN Document Server

    Lax, Peter D

    2011-01-01

    Complex Proofs of Real Theorems is an extended meditation on Hadamard's famous dictum, "The shortest and best way between two truths of the real domain often passes through the imaginary one." Directed at an audience acquainted with analysis at the first year graduate level, it aims at illustrating how complex variables can be used to provide quick and efficient proofs of a wide variety of important results in such areas of analysis as approximation theory, operator theory, harmonic analysis, and complex dynamics. Topics discussed include weighted approximation on the line, Müntz's theorem, Toeplitz operators, Beurling's theorem on the invariant spaces of the shift operator, prediction theory, the Riesz convexity theorem, the Paley-Wiener theorem, the Titchmarsh convolution theorem, the Gleason-Kahane-Żelazko theorem, and the Fatou-Julia-Baker theorem. The discussion begins with the world's shortest proof of the fundamental theorem of algebra and concludes with Newman's almost effortless proof of the prime ...

  4. Chansporter complexes in cell signaling.

    Science.gov (United States)

    Abbott, Geoffrey W

    2017-09-01

    Ion channels facilitate diffusion of ions across cell membranes for such diverse purposes as neuronal signaling, muscular contraction, and fluid homeostasis. Solute transporters often utilize ionic gradients to move aqueous solutes up their concentration gradient, also fulfilling a wide variety of tasks. Recently, an increasing number of ion channel-transporter ('chansporter') complexes have been discovered. Chansporter complex formation may overcome what could otherwise be considerable spatial barriers to rapid signal integration and feedback between channels and transporters, the ions and other substrates they transport, and environmental factors to which they must respond. Here, current knowledge in this field is summarized, covering both heterologous expression structure/function findings and potential mechanisms by which chansporter complexes fulfill contrasting roles in cell signaling in vivo. © 2017 Federation of European Biochemical Societies.

  5. Association theories for complex thermodynamics

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios; Rafiqul Gani

    2013-01-01

    of this review is two-fold: first to illustrate some of the significant capabilities of these association theories and why indeed they have already been extensively used and are expected to find even more applications in the future. The second and most important aspect of this review is to outline many...... applications. While specialized models can handle different cases, even complex ones, with the advent of powerful theories and computers there is the hope that a single or a few models could be suitable for a general modeling of complex thermodynamics. After more than 100 years with active use of thermodynamic...... models, we have now come to the understanding that simple one-fluid theories like the cubic equations of state or the various forms of local composition models will never be able to model a wide range of complex systems with sufficient accuracy. While various modern approaches have appeared, one very...

  6. Characterization of complex renal cysts

    DEFF Research Database (Denmark)

    Graumann, Ole; Osther, Susanne Sloth; Osther, Palle Jörn Sloth

    2010-01-01

    Abstract Objective. Complex renal cysts represent a major clinical problem, since it is often difficult to exclude malignancy. The Bosniak classification system, based on computed tomography (CT), is widely used to categorize cystic renal lesions. The aim of this study was to evaluate critically...... available data on the Bosniak classification. Material and methods. All publications from an Entrez Pubmed search were reviewed, focusing on clinical applicability and the use of imaging modalities other than CT to categorize complex renal cysts. Results. Fifteen retrospective studies were found. Most...

  7. Thermodynamic properties of actinide complexes

    International Nuclear Information System (INIS)

    Bismondo, A.; Cassol, A.; Di Bernardo, P.; Magon, L.; Tomat, G.; Consiglio Nazionale delle Ricerche, Padua

    1981-01-01

    In a previous paper the stability constants and the enthalpies of formation of uranyl(VI)-malonate complexes in 1 M Na(ClO 4 ) and at 25.0 0 C, have been reported. In order to assess the influence of the number of methylenic groups in the ligand chain on the stability constants of the formed complexes and on their ΔH and ΔS values, a series of potentiometric and calorimetric investigations were carried out on the uranyl(VI)-succinate system. The results are given and discussed. (author)

  8. Border detection in complex networks

    International Nuclear Information System (INIS)

    Travencolo, Bruno A N; Viana, Matheus Palhares; Costa, Luciano da Fontoura

    2009-01-01

    One important issue implied by the finite nature of real-world networks regards the identification of their more external (border) and internal nodes. The present work proposes a formal and objective definition of these properties, founded on the recently introduced concept of node diversity. It is shown that this feature does not exhibit any relevant correlation with several well-established complex networks measurements. A methodology for the identification of the borders of complex networks is described and illustrated with respect to theoretical (geographical and knitted networks) as well as real-world networks (urban and word association networks), yielding interesting results and insights in both cases.

  9. CNN a paradigm for complexity

    CERN Document Server

    Chua, Leon O

    1998-01-01

    Revolutionary and original, this treatise presents a new paradigm of EMERGENCE and COMPLEXITY, with applications drawn from numerous disciplines, including artificial life, biology, chemistry, computation, physics, image processing, information science, etc.CNN is an acronym for Cellular Neural Networks when used in the context of brain science, or Cellular Nonlinear Networks, when used in the context of emergence and complexity. A CNN is modeled by cells and interactions: cells are defined as dynamical systems and interactions are defined via coupling laws. The CNN paradigm is a universal Tur

  10. Detergent zeolite complex "Alusil", Zvornik

    OpenAIRE

    Stanković Mirjana S.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed the basis technological and machine projects for a detergent zeolite complex, on the basis of which a pilot plant with an initial capacity of 5,000 t/y was constructed in 1983 within Birač-Zvornik production complex. Additional projects were done afterwards and the starting capacity increased to 200,000 t/y in 1988. This plant became the biggest producer of detergent zeolite in the world. These projects were manufactured on the basis of specific techno...

  11. Workspace Program for Complex-Number Arithmetic

    Science.gov (United States)

    Patrick, M. C.; Howell, Leonard W., Jr.

    1986-01-01

    COMPLEX is workspace program designed to empower APL with complexnumber capabilities. Complex-variable methods provide analytical tools invaluable for applications in mathematics, science, and engineering. COMPLEX written in APL.

  12. Sequence complexity and work extraction

    International Nuclear Information System (INIS)

    Merhav, Neri

    2015-01-01

    We consider a simplified version of a solvable model by Mandal and Jarzynski, which constructively demonstrates the interplay between work extraction and the increase of the Shannon entropy of an information reservoir which is in contact with a physical system. We extend Mandal and Jarzynski’s main findings in several directions: first, we allow sequences of correlated bits rather than just independent bits. Secondly, at least for the case of binary information, we show that, in fact, the Shannon entropy is only one measure of complexity of the information that must increase in order for work to be extracted. The extracted work can also be upper bounded in terms of the increase in other quantities that measure complexity, like the predictability of future bits from past ones. Third, we provide an extension to the case of non-binary information (i.e. a larger alphabet), and finally, we extend the scope to the case where the incoming bits (before the interaction) form an individual sequence, rather than a random one. In this case, the entropy before the interaction can be replaced by the Lempel–Ziv (LZ) complexity of the incoming sequence, a fact that gives rise to an entropic meaning of the LZ complexity, not only in information theory, but also in physics. (paper)

  13. Structural insights into transcription complexes

    NARCIS (Netherlands)

    Berger, I.; Blanco, A.G.; Boelens, R.; Cavarelli, J.; Coll, M.; Folkers, G.E.; Nie, Y.; Pogenberg, V.; Schultz, P.; Wilmanns, M.; Moras, D.; Poterszman, A.

    2011-01-01

    Control of transcription allows the regulation of cell activity in response to external stimuli and research in the field has greatly benefited from efforts in structural biology. In this review, based on specific examples from the European SPINE2-COMPLEXES initiative, we illustrate the impact of

  14. Language Networks as Complex Systems

    Science.gov (United States)

    Lee, Max Kueiming; Ou, Sheue-Jen

    2008-01-01

    Starting in the late eighties, with a growing discontent with analytical methods in science and the growing power of computers, researchers began to study complex systems such as living organisms, evolution of genes, biological systems, brain neural networks, epidemics, ecology, economy, social networks, etc. In the early nineties, the research…

  15. Complexity control in statistical learning

    Indian Academy of Sciences (India)

    Then we describe how the method of regularization is used to control complexity in learning. We discuss two examples of regularization, one in which the function space used is finite dimensional, and another in which it is a reproducing kernel Hilbert space. Our exposition follows the formulation of Cucker and Smale.

  16. Thermodynamic properties of actinide complexes

    International Nuclear Information System (INIS)

    Di Bernardo, P.; Tomat, G.; Bismondo, A.

    1980-01-01

    The present paper reports a continuation of investigations on the complexing ability of substituted polycarboxylate ligands toward the uranyl(VI) ion. The changes in free energy were computed from the stability constants determined by potentiometric measurements; the enthalpy changes were measured by direct calorimetric titrations. The acid formation constants and the complex formation constants were calculated with the aid of a CDC/CRYBER '76 computer using the programs LETAGROP VRID and MINIQUAD 75. The enthalpy changes for the proton ligand and metal ligand complex formation were calculated by the least-squares program LETAGROP KALLE. The data obtained for a relatively wide range of concentrations of the metal and hydrogen ions may be interpreted in terms of the formation of simple mononuclear, ML, and acid complexes, Msub(p)Hsub(q)Lsub(r), where p = 1; q = 1, 2; r = 1, 2. The values of free energy enthalpy, and entropy changes for the systems investigated are reported together with the logarithms of the corresponding stability constants. (author)

  17. Copper complexes as chemical nucleases

    Indian Academy of Sciences (India)

    Unknown

    anticancer drug famotidine has been shown as a better catalyst than CuCl2 for sulfite ... Effect of addition of bis-chelate copper(II) complexes (dpq, •; phen, ; ..... Reproduction, Development & Genetics for their help in the DNA cleavage studies ...

  18. Simulating complex noise barrier reflections

    NARCIS (Netherlands)

    Eerden, F.J.M. van der; Lutgendorf, D.; Roo, F. de

    2011-01-01

    Within the EU FP7 QUIESST project, QUIeting the Environment for a Sustainable Surface Transport, a test method is being developed for the reflectivity of noise barriers. The method needs to account for a complex shape of barriers and the use of various types of absorbing materials. The performance

  19. Disentangling the Trichoderma viridescens complex

    NARCIS (Netherlands)

    Jaklitsch, W.M.; Samuels, G.J.; Ismaiel, A.; Voglmayr, H.

    2013-01-01

    Trichoderma viridescens is recognised as a species complex. Multigene analyses based on the translation elongation factor 1-alpha encoding gene (tef1), a part of the rpb2 gene, encoding the second largest RNA polymerase subunit and the larger subunit of ATP citrate lyase (acl1) reveals 13

  20. Data complexity in pattern recognition

    CERN Document Server

    Kam Ho Tin

    2006-01-01

    Machines capable of automatic pattern recognition have many fascinating uses. Algorithms for supervised classification, where one infers a decision boundary from a set of training examples, are at the core of this capability. This book looks at data complexity and its role in shaping the theories and techniques in different disciplines