Sample records for avatakse eka galeriis

  1. Correlation, relativistic, and quantum electrodynamics effects on the atomic structure of eka-thorium

    SciTech Connect

    Gaigalas, Gediminas; Gaidamauskas, Erikas; Rudzikas, Zenonas; Magnani, Nicola; Caciuffo, Roberto


    Large-scale multiconfiguration Dirac-Fock calculations have been performed for the superheavy element eka-thorium, Z=122. The resulting atomic structure is compared with that obtained by various computational approaches involving different degrees of approximation in order to elucidate the role that correlation, relativistic, Breit, and quantum electrodynamics corrections play in determining the low-energy atomic spectrum. The accuracy of the calculations is assessed by comparing theoretical results obtained for thorium with available experimental data.

  2. Search for long-lived superheavy eka-tungsten with radiopure ZnWO4 crystal scintillator

    NASA Astrophysics Data System (ADS)

    Belli, P.; Bernabei, R.; Cappella, F.; Cerulli, R.; Danevich, F. A.; Denisov, V. Yu; d'Angelo, A.; Incicchitti, A.; Kobychev, V. V.; Poda, D. V.; Polischuk, O. G.; Tretyak, V. I.


    The data collected with a radioactively pure ZnWO4 crystal scintillator (699 g) in low background measurements during 2130 h at the underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (INFN, Italy) were used to set a limit on possible concentration of superheavy eka-W (seaborgium Sg, Z = 106) in the crystal. Assuming that one of the daughters in a chain of decays of the initial Sg nucleus decays with emission of high energy α particle ({{Q}α }\\gt 8 MeV) and analyzing the high energy part of the measured α spectrum, the limit N(Sg)/N(W) \\lt 5.5× {{10}-14} atoms/atom at 90% C.L. was obtained (for Sg half-life of 109 yr). In addition, a limit on the concentration of eka-Bi was set by analysing the data collected with a large BGO scintillation bolometer in an experiment performed by another group (Cardani et al 2012 JINST 7 P10022): N(eka-Bi)/N(Bi) \\lt 1.1× {{10}-13} atoms/atom with 90% C.L. Both the limits are comparable with those obtained in recent experiments which instead look for spontaneous fission of superheavy elements or use the accelerator mass spectrometry.

  3. 4-Component correlated all-electron study on Eka-actinium Fluoride (E121F) including Gaunt interaction: Accurate analytical form, bonding and influence on rovibrational spectra

    NASA Astrophysics Data System (ADS)

    Amador, Davi H. T.; de Oliveira, Heibbe C. B.; Sambrano, Julio R.; Gargano, Ricardo; de Macedo, Luiz Guilherme M.


    A prolapse-free basis set for Eka-Actinium (E121, Z = 121), numerical atomic calculations on E121, spectroscopic constants and accurate analytical form for the potential energy curve of diatomic E121F obtained at 4-component all-electron CCSD(T) level including Gaunt interaction are presented. The results show a strong and polarized bond (≈181 kcal/mol in strength) between E121 and F, the outermost frontier molecular orbitals from E121F should be fairly similar to the ones from AcF and there is no evidence of break of periodic trends. Moreover, the Gaunt interaction, although small, is expected to influence considerably the overall rovibrational spectra.

  4. Quantum electrodynamic corrections for valence electrons in Eka-Hg

    NASA Astrophysics Data System (ADS)

    Golovko, O. A.; Goidenko, I. A.; Tupitsyn, I. I.


    The quantum electrodynamic (QED) corrections to the coupling energy of valence electrons in heavy and superheavy nuclei are calculated in the effective local-potential approximation, as well as by the Hartree-Fock-Dirac self-consistent method. It is clearly shown that the contribution from the QED corrections is within the accuracy of modern calculations, which do not take into account QED effects. It is shown that, in certain cases, to exactly calculate the coupling energy of electrons in heavy and superheavy atoms, it is necessary to take into account the self-consistency, which shows that the inaccuracy of the use of the method of the effective local potential in calculations of QED effects can exceed 10%, which is also within the limits of calculations of the coupling energy without taking into account QED effects.

  5. Code White: A Signed Code Protection Mechanism for Smartphones

    DTIC Science & Technology


    if(TheSuperPage().KernelConfigFlags() & EKernelConfigPlatSecProcessIsolation) { diff -r 2ee5df201f60 kernel/eka/memmodel/ epoc /multiple...mprocess.cpp --- a/kernel/eka/memmodel/ epoc /multiple/mprocess.cpp Mon Mar 08 11:58:34 2010 +0000 +++ b/kernel/eka/memmodel/ epoc /multiple/mprocess.cpp Thu

  6. An ent-kaurene that inhibits mitotic chromosome movement and binds the kinetochore protein ran-binding protein 2.


    Rundle, Natalie T; Nelson, Jim; Flory, Mark R; Joseph, Jomon; Th'ng, John; Aebersold, Ruedi; Dasso, Mary; Andersen, Raymond J; Roberge, Michel


    Using a chemical genetics screen, we have identified ent-15-oxokaurenoic acid (EKA) as a chemical that causes prolonged mitotic arrest at a stage resembling prometaphase. EKA inhibits the association of the mitotic motor protein centromeric protein E with kinetochores and inhibits chromosome movement. Unlike most antimitotic agents, EKA does not inhibit the polymerization or depolymerization of tubulin. To identify EKA-interacting proteins, we used a cell-permeable biotinylated form that retains biological activity to isolate binding proteins from living cells. Mass spectrometric analysis identified six EKA-binding proteins, including Ran-binding protein 2, a kinetochore protein whose depletion by small interfering RNA causes a similar mitotic arrest phenotype.

  7. Interaction of endokinin A/B and (Mpa(6))-γ2-MSH-6-12 in pain regulation in mice.


    Zhou, Lanxia; Yang, Qing; He, Chunbo; Wei, Chunnan; Yang, Yinliang; Dong, Shouliang


    The present study focused on the interactive effects of (Mpa(6))-γ2-MSH-6-12 (Mpa, spinal level) and endokinin A/B (EKA/B, supraspinal level) on pain regulation in mice. EKA/B (30 pmol) only weakened 100 pmol Mpa-induced hyperalgesia at 5 min, but could enhance it during 20-30 min. However, EKA/B (100 pmol) antagonized all dose levels of Mpa significantly at 5 min and blocked them completely at 10 min. EKA/B (3 nmol) co-injected with Mpa presented marked analgesia at 5 min and enduring hyperalgesia within 20-60 min. To investigate the underlying mechanisms between Mpa and EKA/B, SR140333B and SR142801 (NK1 and NK3 receptor antagonists, respectively) were utilized. SR140333B had no influence on Mpa, while SR142801 potentiated it during 20-30 min. Whereas, SR140333B and SR142801 could block the co-administration of Mpa and EKA/B (30 pmol) separately at 5 min and 30 min. These phenomena might attribute to that these two antagonists promoted the antagonism of EKA/B (30 pmol) at the early stage, while antagonized EKA/B preferentially in the latter period. SR140333B weakened the analgesia of EKA/B (3 nmol), but produced no effect on Mpa. However, SR140333B failed to affect the co-injection of Mpa and EKA/B, which implied that EKA/B cooperated with Mpa prior to SR140333B. These results could potentially help to better understand the interaction of NK and MrgC receptors in pain regulation in mice.

  8. Inventory using laser scanning of the control gallery and overflow sectionof Klimkówka earthfill dam - experiences and conclusions. (Polish Title: Inwentaryzacja galerii kontrolnej i przelewu zapory ziemnej Klimkówka metodą skanowania laserowego)

    NASA Astrophysics Data System (ADS)

    Zaczek-Peplinska, J.; Adamek, Artur; Osińska-Skotak, K.; Adamek, Anna


    The paper discusses experiences resulting from the surveying inventory of Klimkówka earthdam's control gallery. Current status of the law, which impose obligation of adequate technical control onthe unit administering and operating hydraulic structures is presented. Laser scanning due to the lack of suitable developed measurements methodology for this type of objects is rarely used for its inventory and control. In August 2012, the measurement of displacements of control gallery of this object using precise levelling was conducted by the staff and the students from the Department of Engineering and Detailed Surveying (WUT, Faculty of Geodesy and Cartography). Simultaneously, an inventory of control gallery using terrestrial laser scanning was made. In addition, during the processing the data an attempt to analyse the I values (Intensity) was made which were recorded during the measure of concrete overflow using automated image analysis in order to carry out the characteristic classification of the concrete -this analysis is to be used as a starting material for the analysis of changes in the surface of the concrete in the following years. The results of an inventory of geometry of the control gallery and a preliminary analysis of the surface of the concrete overflow using unsupervised classification method have been presented. The process of gallery model creation, as well as selected possible analyses and measurements based on the data from terrestrial laser scanning have been also described.

  9. Pain regulation of endokinin A/B or endokinin C/D on chimeric peptide MCRT in mice.


    He, Chunbo; Gong, Junbin; Yang, Lixia; Zhang, Hongwei; Dong, Shouliang; Zhou, Lanxia


    The present study focused on the interactive pain regulation of endokinin A/B (EKA/B, the common C-terminal decapeptide in EKA and EKB) or endokinin C/D (EKC/D, the common C-terminal duodecapeptide in EKC and EKD) on chimeric peptide MCRT (YPFPFRTic-NH2, based on YPFP-NH2 and PFRTic-NH2) at the supraspinal level in mice. Results demonstrated that the co-injection of nanomolar EKA/B and MCRT showed moderate regulation, whereas 30 pmol EKA/B had no effect on MCRT. The combination of EKC/D and MCRT produced enhanced antinociception, which was nearly equal to the sum of the mathematical values of single EKC/D and MCRT. Mechanism studies revealed that pre-injected naloxone attenuated the combination significantly compared with the equivalent analgesic effects of EKC/D alone, suggesting that EKC/D and MCRT might act on two totally independent pathways. Moreover, based on the above results and previous reports, we made two reasonable hypotheses to explain the cocktail-induced analgesia, which may potentially pave the way to explore the respective regulatory mechanisms of EKA/B, EKC/D, and MCRT and to better understand the complicated pain regulation of NK1 and μ opioid receptors, as follows: (1) MCRT and endomorphin-1 possibly activated different μ subtypes; and (2) picomolar EKA/B might motivate the endogenous NPFF system after NK1 activation.

  10. 75 FR 15679 - Initiation of Antidumping and Countervailing Duty Administrative Reviews and Request for...

    Federal Register 2010, 2011, 2012, 2013, 2014


    ...: Certain Preserved Mushrooms, A-533-813 2/1/09-1/31/10 Agro Dutch Foods Limited (Agro Dutch Industries... Indonesia: Certain Preserved Mushrooms, A-560-802 2/1/09-1/31/10 PT Eka Timur Raya (ETIRA) PT Indo Evergreen... Preserved Mushrooms,\\6\\ A-570-851....... 2/1/09-1/31/10 Ayecue (Liaocheng) Foodstuff Co., Ltd. Blue...

  11. Impedance characteristics and polarization behavior of a microbial fuel cell in response to short-term changes in medium pH.


    Jung, Sokhee; Mench, Matthew M; Regan, John M


    pH oppositely influences anode and cathode performance in microbial fuel cells. The differential electrochemical effects at each electrode and the resultant full-cell performance were analyzed in medium pH from 6.0 to 8.0. Potentials changed -60 mV/pH for the anode and -68 mV/pH for the cathode, coincident with thermodynamic estimations. Open circuit voltage reached a maximum (741 mV) at pH 7, and maximum power density was highest (712 mW/m²) at pH 6.5 as the cathode performance improved at lower pH. Maximum current density increased and apparent half-saturation potential (E(KA)) decreased with increasing medium pH due to improved anode performance. An equivalent circuit model composed of two time constant processes accurately fit bioanode impedance data. One of these processes was consistently the rate-limiting step for acetate-oxidizing exoelectrogenesis, with its pH-varying charge transfer resistance R₂ ranging from 2- to 321-fold higher than the pH-independent charge transfer resistance R₁. The associated capacitance C₂ was 2-3 orders of magnitude larger than C₁. R₂ was lowest near E(KA) and increased by several orders of magnitude at anode potentials above E(KA), while R₁ was nearly stable. However, fits deviated slightly at potentials above E(KA) due to emerging impedance possibly associated with diffusion and excessive potential.

  12. 76 FR 58079 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

    Federal Register 2010, 2011, 2012, 2013, 2014


    ... fencing and gates. Install fencing and gates. Brief Description of Projects Approved for Collection at ACV and Use at Murray Field (EKA): Design wildlife perimeter fencing. Design automated weather observing.... Design fencing and gates. Construct fencing and gates. Brief Description of Project Approved...

  13. Department of Operations Research Technical Report List 1966-1976.

    DTIC Science & Technology


    udgeting J # M. , ing , 1976. * aal ts 55KX75121, lity Lawrance , A. Lawrance , A. Learmonth, G. Learmonth, G. Lehoczky, J. Lehoczky, J. Lewis...point process (EARMA 1, 1), NPS55LM75101, 1975. Lewis, P. A. I., and Lawrance , A. J.: A moving average exponential point process (EKA1...NPS55LW75Ü61, 1975. Lewis, P. A. W., and Lawrance , A. J.: Properties of the bivariate delayed Poisson process, NPS55LW74071, Lewis, P. A. W. , and

  14. How far can we go? Quantum-chemical investigations of oxidation state +IX.


    Himmel, Daniel; Knapp, Carsten; Patzschke, Michael; Riedel, Sebastian


    The highest known oxidation state of any element is +VIII. After the recent discovery of Ir(VIII)O(4) under cryogenic conditions, we have investigated the stability of cationic species [MO(4)](+) (M=Rh,Ir,Mt). Such compounds would formally represent the new oxidation state +IX, which is experimentally unknown so far for the whole periodic table. [IrO(4)](+) is predicted to be the most promising candidate. The calculated spin-orbit (SO) coupling shows only minor effects on the stability of the iridium species, whereas SO-coupling increases enormously for the corresponding Eka-Iridium (Meitnerium) complexes and destabilizes these.

  15. Ohmic resistance affects microbial community and electrochemical kinetics in a multi-anode microbial electrochemical cell

    NASA Astrophysics Data System (ADS)

    Dhar, Bipro Ranjan; Ryu, Hodon; Santo Domingo, Jorge W.; Lee, Hyung-Sool


    Multi-anode microbial electrochemical cells (MxCs) are considered as one of the most promising configurations for scale-up of MxCs, but understanding of anode kinetics in multiple anodes is limited in the MxCs. In this study we assessed microbial community and electrochemical kinetic parameters for biofilms on individual anodes in a multi-anode MxC to better comprehend anode fundamentals. Microbial community analysis targeting 16S rRNA Illumina sequencing showed that Geobacter genus was abundant (87%) only on the biofilm anode closest to a reference electrode (low ohmic energy loss) in which current density was the highest among three anodes. In comparison, Geobacter populations were less than 1% for biofilms on other two anodes distant from the reference electrode (high ohmic energy loss), generating small current density. Half-saturation anode potential (EKA) was the lowest at -0.251 to -0.242 V (vs. standard hydrogen electrode) for the closest biofilm anode to the reference electrode, while EKA was as high as -0.134 V for the farthest anode. Our study proves that electric potential of individual anodes changed by ohmic energy loss shifts biofilm communities on individual anodes and consequently influences electron transfer kinetics on each anode in the multi-anode MxC.

  16. Chemical experiments with superheavy elements.


    Türler, Andreas


    Unnoticed by many chemists, the Periodic Table of the Elements has been extended significantly in the last couple of years and the 7th period has very recently been completed with eka-Rn (element 118) currently being the heaviest element whose synthesis has been reported. These 'superheavy' elements (also called transactinides with atomic number > or = 104 (Rf)) have been artificially synthesized in fusion reactions at accelerators in minute quantities of a few single atoms. In addition, all isotopes of the transactinide elements are radioactive and decay with rather short half-lives. Nevertheless, it has been possible in some cases to investigate experimentally chemical properties of transactinide elements and even synthesize simple compounds. The experimental investigation of superheavy elements is especially intriguing, since theoretical calculations predict significant deviations from periodic trends due to the influence of strong relativistic effects. In this contribution first experiments with hassium (Hs, atomic number 108), copernicium (Cn, atomic number 112) and element 114 (eka-Pb) are reviewed.

  17. Influence of the sulfation degree of glycosaminoglycans on their multilayer assembly with poly-l-lysine.


    Teixeira, Raquel; Reis, Rui L; Pashkuleva, Iva


    We report on the build-up and the intrinsic properties of polyelectrolyte multilayer films from poly-l-lysine and glycosaminoglycans (GAGs) with different sulfation degree, i.e. different charge. We used three complementary techniques, namely electrokinetic analysis (EKA), quartz-crystal microbalance with dissipation (QCM-D) and surface plasmon resonance (SPR), to characterize the assembly process and to assess the properties of the obtained films. EKA elucidated the contribution of the polymers charged groups to the net surface charge of the films and suggested that the assembly process is not solely driven by electrostatic interactions. The combined analysis of QCM-D and SPR data demonstrated that the mechanical properties of the films are dependent on the polymer charge: sulfated GAGs (heparin and chondroitin sulfate) form elastic films while hyaluronan (no sulfation) assembles into multilayer constructs with viscous behavior. The contribution of the water content to these distinct regimes is also discussed. Finally, we show that rather complete characterization of the film properties is possible by SPR employing the two-wavelength and two-media approach: thickness, adsorbed mass, refractive index, and interaction kinetics of the assembly process can be studied by SPR alone.

  18. Ohmic resistance affects microbial community and ...

    EPA Pesticide Factsheets

    Multi-anode microbial electrochemical cells (MXCs) are considered as one of the most promising configurations for scale-up of MXCs, but fundamental understanding of anode kinetics governing current density is limited in the MXCs. In this study we first assessed microbial community and electrochemical kinetic parameters for biofilms on individual anodes in a multi-anode MXC to better comprehend anode fundamentals. Microbial community analysis using 16S rRNA illumine sequencing showed that Geobactor genus, one of the most kinetically efficient anode-respiring bacteria (ARB), was abundant (87%) only on the biofilm anode closest to a reference electrode in which current density was the highest among four anodes. In comparison, Geobacter populations were less than 11% for other three anodes more distant from the reference electrode, generating small current density. Half-saturation anode potential (EKA) was the lowest at -0.251 to -0.242 V (vs. standard hydrogen electrode) for the closest anode, while EKA was as high as -0.134 V for the farthest anode. Our study clearly proves that ohmic resistance changes anode potential which mainly causes different biofilm communities on individual anodes and consequently influences anode kinetics. This study explored the use of multiple anodes in microelectrochemical cells and the microbial community on these anodes, as a function of the efficiency in producing hydrogen peroxide.

  19. Two-component relativistic density-functional calculations of the dimers of the halogens from bromine through element 117 using effective core potential and all-electron methods.


    Mitin, Alexander V; van Wüllen, Christoph


    A two-component quasirelativistic Hamiltonian based on spin-dependent effective core potentials is used to calculate ionization energies and electron affinities of the heavy halogen atom bromine through the superheavy element 117 (eka-astatine) as well as spectroscopic constants of the homonuclear dimers of these atoms. We describe a two-component Hartree-Fock and density-functional program that treats spin-orbit coupling self-consistently within the orbital optimization procedure. A comparison with results from high-order Douglas-Kroll calculations--for the superheavy systems also with zeroth-order regular approximation and four-component Dirac results--demonstrates the validity of the pseudopotential approximation. The density-functional (but not the Hartree-Fock) results show very satisfactory agreement with theoretical coupled cluster as well as experimental data where available, such that the theoretical results can serve as an estimate for the hitherto unknown properties of astatine, element 117, and their dimers.

  20. UK National Data Centre archive of seismic recordings of (presumed) underground nuclear tests 1964-1996

    NASA Astrophysics Data System (ADS)

    Young, John; Peacock, Sheila


    The year 1996 has particular significance for forensic seismologists. This was the year when the Comprehensive Test Ban Treaty (CTBT) was signed in September at the United Nations, setting an international norm against nuclear testing. Blacknest, as a long time seismic centre for research into detecting and identifying underground explosions using seismology, provided significant technical advice during the CTBT negotiations. Since 1962 seismic recordings of both presumed nuclear explosions and earthquakes from the four seismometer arrays Eskdalemuir, Scotland (EKA), Yellowknife, Canada (YKA), Gauribidanur, India (GBA), and Warramunga, Australia (WRA) have been copied, digitised, and saved. There was a possibility this archive would be lost. It was decided to process the records and catalogue them for distribution to other groups and institutions. This work continues at Blacknest but the archive is no longer under threat. In addition much of the archive of analogue tape recordings has been re-digitised with modern equipment, allowing sampling rates of 100 rather than 20 Hz.

  1. Random pure states: Quantifying bipartite entanglement beyond the linear statistics.


    Vivo, Pierpaolo; Pato, Mauricio P; Oshanin, Gleb


    We analyze the properties of entangled random pure states of a quantum system partitioned into two smaller subsystems of dimensions N and M. Framing the problem in terms of random matrices with a fixed-trace constraint, we establish, for arbitrary N≤M, a general relation between the n-point densities and the cross moments of the eigenvalues of the reduced density matrix, i.e., the so-called Schmidt eigenvalues, and the analogous functionals of the eigenvalues of the Wishart-Laguerre ensemble of the random matrix theory. This allows us to derive explicit expressions for two-level densities, and also an exact expression for the variance of von Neumann entropy at finite N,M. Then, we focus on the moments E{K^{a}} of the Schmidt number K, the reciprocal of the purity. This is a random variable supported on [1,N], which quantifies the number of degrees of freedom effectively contributing to the entanglement. We derive a wealth of analytical results for E{K^{a}} for N=2 and 3 and arbitrary M, and also for square N=M systems by spotting for the latter a connection with the probability P(x_{min}^{GUE}≥sqrt[2N]ξ) that the smallest eigenvalue x_{min}^{GUE} of an N×N matrix belonging to the Gaussian unitary ensemble is larger than sqrt[2N]ξ. As a by-product, we present an exact asymptotic expansion for P(x_{min}^{GUE}≥sqrt[2N]ξ) for finite N as ξ→∞. Our results are corroborated by numerical simulations whenever possible, with excellent agreement.

  2. Kinetic experiments for evaluating the Nernst-Monod model for anode-respiring bacteria (ARB) in a biofilm anode.


    Torres, César I; Marcus, Andrew Kato; Parameswaran, Prathap; Rittmann, Bruce E


    Anode-respiring bacteria (ARB) are able to transfer electrons from reduced substrates to a solid electrode. Previously, we developed a biofilm model based on the Nernst-Monod equation to describe the anode potential losses of ARB that transfer electrons through a solid conductive matrix. In this work, we develop an experimental setup to demonstrate how well the Nernst-Monod equation is able to represent anode potential losses in an ARB biofilm. We performed low-scan cyclic voltammetry (LSCV) throughout the growth phase of an ARB biofilm on a graphite electrode growing on acetate in continuous mode. The (j)V response of 9 LSCVs corresponded well to the Nernst-Monod equation, and the half-saturation potential (E(KA)) was -0.425 +/- 0.002 V vs Ag/AgCl at 30 degrees C (-0.155 +/- 0.002 V vs SHE). Anode-potential losses from the potential of acetate reached approximately 0.225 V at current density saturation, and this loss was determined by our microbial community's E(KA) value. The LSCVs at high current densities showed no significant deviation from the Nernst-Monod ideal shape, indicating that the conductivity of the biofilm matrix (kappa(bio)) was high enough (> or = 0.5 mS/cm) that potential loss did not affect the performance of the biofilm anode. Our results confirm the applicability of the Nernst-Monod equation for a conductive biofilm anode and give insights of the processes that dominate anode potential losses in microbial fuel cells.

  3. Chemical and nuclear properties of lawrencium (element 103) and hahnium (element 105)

    SciTech Connect

    Henderson, R.A.


    The chemical and nuclear properties of Lr and Ha have been studied, using 3-minute {sup 260}Lr and 35-second {sup 262}Ha. The crystal ionic radius of Lr{sup 3+} was determined by comparing its elution position from a cation-exchange resin column with those of lanthanide elements having known ionic radii. Comparisons are made to the ionic radii of the heavy actinides, Am{sup 3+} through Es{sup 3+}, obtained by x-ray diffraction methods, and to Md{sup 3+} and Fm{sup 3+} which were determined in the same manner as Lr{sup 3+}. The hydration enthalpy of {minus}3622 kJ/mol was calculated from the crystal ionic radius using an empirical form of the Born equation. Comparisons to the spacings between the ionic radii of the heaviest members of the lanthanide series show that the 2Z spacing between Lr{sup 3+} and Md{sup 3+} is anomalously small, as the ionic radius of Lr{sup 3+} of 0.0886 nm is significantly smaller than had been expected. The chemical properties of Ha were determined relative to the lighter homologs in group 5, Nb and Ta. Group 4 and group 5 tracer activities, as well as Ha, were absorbed onto glass surfaces as a first step toward the determination of the chemical properties of Ha. Ha was found to adsorb on surfaces, a chemical property unique to the group 5 elements, and as such demonstrates that Ha has the chemical properties of a group 5 element. A solvent extraction procedure was adapted for use as a micro-scale chemical procedure to examine whether or not Ha displays eka-Ta-like chemical under conditions where Ta will be extracted into the organic phase and Nb will not. Under the conditions of this experiment Ha did not extract, and does not show eka-Ta-like chemical properties.

  4. Chemical properties of the heavier actinides and transactinides

    SciTech Connect

    Hulet, E.K.


    The chemical properties of each of the elements 99 (Es) through 105 are reviewed and their properties correlated with the electronic structure expected for 5f and 6d elements. A major feature of the heavier actinides, which differentiates them from the comparable lanthanides, is the increasing stability of the divalent oxidation state with increasing atomic number. The divalent oxidation state first becomes observable in the anhydrous halides of californium and increases in stability through the series to nobelium, where this valency becomes predominant in aqueous solution. In comparison with the analogous 4f electrons, the 5f electrons in the latter part of the series are more tightly bound. Thus, there is a lowering of the 5f energy levels with respect to the Fermi level as the atomic number increases. The metallic state of the heavier actinides has not been investigated except from the viewpoint of the relative volatility among members of the series. In aqueous solutions, ions of these elements behave as a normal trivalent actinides and lanthanides (except for nobelium). Their ionic radii decrease with increasing nuclear charge which is moderated because of increased screening of the outer 6p electrons by the 5f electrons. The actinide series of elements is completed with the element lawrencium (Lr) in which the electronic configuration is 5f/sup 14/7s/sup 2/7p. From Mendeleev's periodicity and Dirac-Fock calculations, the next group of elements is expected to be a d-transition series corresponding to the elements Hf through Hg. The chemical properties of elements 104 and 105 only have been studied and they indeed appear to show the properties expected of eka-Hf and eka-Ta. However, their nuclear lifetimes are so short and so few atoms can be produced that a rich variety of chemical information is probably unobtainable.

  5. Gallium--A smart metal

    USGS Publications Warehouse

    Foley, Nora; Jaskula, Brian W.


    Gallium is a soft, silvery metallic element with an atomic number of 31 and the chemical symbol Ga. The French chemist Paul-Emile Lecoq de Boisbaudran discovered gallium in sphalerite (a zinc-sulfide mineral) in 1875 using spectroscopy. He named the element "gallia" after his native land of France (formerly Gaul; in Latin, Gallia). The existence of gallium had been predicted in 1871 by Dmitri Mendeleev, the Russian chemist who published the first periodic table of the elements. Mendeleev noted a gap in his table and named the missing element "eka-aluminum" because he determined that its location was one place away from aluminum in the table. Mendeleev thought that the missing element (gallium) would be very much like aluminum in its chemical properties, and he was right. Solid gallium has a low melting temperature (~29 degrees Celsius, or °C) and an unusually high boiling point (~2,204 °C). Because of these properties, the earliest uses of gallium were in high-temperature thermometers and in designing metal alloys that melt easily. The development of a gallium-based direct band-gap semiconductor in the 1960s led to what is now one of the most well-known applications for gallium-based products--the manufacture of smartphones and data-centric networks.

  6. Final Report

    SciTech Connect

    Sujit Banerjee


    Contaminants present in paper recycling mills can degrade product properties and can also lead to substantial downtime. Of these, adhesive material such as hot melts and pressure sensitive adhesives are especially troublesome. These are known as “ stickies ” and their handling and re- moval requires process equipment such as screens and cleaners as well as chemical additives. In the preceding phase of the project we demonstrated that firing an underwater spark in a tank of stock reduces the tack of the stickies and reduces their impact. The present phase was to demon- strate the technology in full-scale trials, address any issues that might arise, and commercialize the process. Trials were run at the Appleton papers mill in West Carrollton, OH, the Graphics Packag- ing mill at Kalamazoo, MI, Stora Enso mills at Duluth, MN, and Wisconsin Rapids, WI, and the Jackson Paper mill at Sylva, NC. It was shown that the sparker not only detackified stickies but also increased the efficiency of their removal by centrifugal cleaners, improved the effectiveness of dissolved air flotation, and increased the efficiency of flotation deinking. It is estimated that the sparker improves the efficiency of hydrocyclone cleaner, deinking cells and dissolved and dispersed air flotation units by 10-15%. This translates to a corresponding energy benefit in operating these units. The technology has been licensed to Eka Chemicals, a division of Akzo Nobel.

  7. The generator coordinate Dirac-Fock method for open-shell atomic systems

    NASA Astrophysics Data System (ADS)

    Malli, Gulzari L.; Ishikawa, Yasuyuki


    Recently we developed generator coordinate Dirac-Fock and Dirac-Fock-Breit methods for closed-shell systems assuming finite nucleus and have reported Dirac-Fock and Dirac-Fock-Breit energies for the atoms He through Nobelium (Z=102) [see Refs. Reference 10Reference 11Reference 12Reference 13]. In this paper, we generalize our earlier work on closed-shell systems and develop a generator coordinate Dirac-Fock method for open-shell systems. We present results for a number of representative open-shell heavy atoms (with nuclear charge Z>80) including the actinide and superheavy transactinide (with Z>103) atomic systems: Fr (Z=87), Ac (Z=89), and Lr (Z=103) to E113 (eka-thallium, Z=113). The high accuracy obtained in our open-shell Dirac-Fock calculations is similar to that of our closed-shell calculations, and we attribute it to the fact that the representation of the relativistic dynamics of an electron in a spherical ball finite nucleus near the origin in terms of our universal Gaussian basis set is as accurate as that provided by the numerical finite difference method. The DF SCF energies calculated by Desclaux [At. Data. Nucl. Data Tables 12, 311 (1973)] (apart from a typographic error for Fr pointed out here) are higher than those reported here for atoms of some of the superheavy transactinide elements by as much as 5 hartrees (136 eV). We believe that this is due to the use by Desclaux of much larger atomic masses than the currently accepted values for these elements.

  8. Growth of the eye lens: I. Weight accumulation in multiple species

    PubMed Central


    Purpose To examine the accumulation of wet and/or dry weight in the ocular lens as a function of age in different species. Methods Wet weights and/or fixed dry weights were obtained from measurements in the author’s laboratory and from the literature for over 14,000 lenses of known-ages, representing 130 different species. Various algorithms were tested to determine the most suitable for describing the relationship between lens weight and age. Results For 126 of the species examined, lens growth is continuous throughout life but asymptotic and can be reasonably described with a single logistic equation, W=Wm e-(k/A), where W is lens wet or dry weight; Wm is the maximum asymptotic weight, k is the logistic growth constant and A is the time from conception. For humans, elephants, hippopotami, minks, wild goats and woodchucks, lens growth appears to be biphasic. No gender differences could be detected in the lens weights for 70 species but male lenses are reportedly 10% larger than those of females in northern fur seals and pheasants. Dry weight accumulation is faster than that for wet weight in all species except birds and reptiles where the rates are the same. Low lens growth rates are associated with small animals with short gestation periods and short life spans. Conclusions Lens growth is continuous throughout life and, for most species, is independent of gender. For most, growth takes place through a monophasic asymptotic mode and is unaffected by events such as hibernation. This makes lens weight measurement a reliable tool for age determination of species culled in the wild. Compaction of the growing lens generates different properties, appropriate to an animal's lifestyle. How these events are controlled remains to be established. PMID:24715758

  9. The noble gases: how their electronegativity and hardness determines their chemistry.


    Furtado, Jonathan; De Proft, Frank; Geerlings, Paul


    The establishment of an internally consistent scale of noble gas electronegativities is a long-standing problem. In the present study, the problem is attacked via the Mulliken definition, which in recent years gained widespread use to its natural appearance in the context of conceptual density functional theory. Basic ingredients of this scale are the electron affinity and the ionization potential. Whereas the latter can be computed routinely, the instability of the anion makes the judicious choice of computational technique for evaluating electron affinities much more tricky. We opted for Puiatti's approach, extrapolating the energy of high ε solvent stabilized anions to the ε = 1 (gas phase) case. The results give negative electron affinity values, monotonically increasing (except for helium which is an outlier in most of the story) to almost zero at eka-radon in agreement with high level calculations. The stability of the B3LYP results is successfully tested both via improving the level of theory (CCSD(T)) and expanding the basis set. Combined with the ionization energies (in good agreement with experiment), an electronegativity scale is obtained displaying (1) a monotonic decrease of χ when going down the periodic table, (2) top values not for the noble gases but for the halogens, as opposed to most (extrapolation) procedures of existing scales, invariably placing the noble gases on top, and (3) noble gases having electronegativities close to the chalcogens. In the accompanying hardness scale (hardly, if ever, discussed in the literature) the noble gases turn out to be by far the farthest the hardest elements, again with a continuous decrease with increasing Z. Combining χ value of the halogens and the noble gases the Ng(δ+)F(δ-) bond polarity emerging from ab initio calculations naturally emerges. In conclusion, the chemistry of the noble gases is for a large part determined by their extreme hardness, equivalent to a high resistance to change in its

  10. Bali, Shaded Relief and Colored Height

    NASA Technical Reports Server (NTRS)


    The volcanic nature of the island of Bali is evident in this shaded relief image generated with data from the Shuttle Radar Topography Mission (SRTM).

    Bali, along with several smaller islands, make up one of the 27 Provinces of Indonesia. It lies over a major subduction zone where the Indo-Australian tectonic plate collides with the Sunda plate, creating one of the most volcanically active regions on the planet.

    The most significant feature on Bali is Gunung Agung, the symmetric, conical mountain at the right-center of the image. This 'stratovolcano,' 3,148 meters (10,308 feet) high, is held sacred in Balinese culture, and last erupted in 1963 after being dormant and thought inactive for 120 years. This violent event resulted in over 1,000 deaths, and coincided with a purification ceremony called Eka Dasa Rudra, meant to restore the balance between nature and man. This most important Balinese rite is held only once per century, and the almost exact correspondence between the beginning of the ceremony and the eruption is though to have great religious significance.

    Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.

    Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter

  11. The Applicability of Incoherent Array Processing to IMS Seismic Arrays

    NASA Astrophysics Data System (ADS)

    Gibbons, Steven J.


    The seismic arrays of the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are highly diverse in size and configuration, with apertures ranging from under 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high-frequency phases lacking coherence between sensors. Pipeline detection algorithms often miss such phases, since they only consider frequencies low enough to allow coherent array processing, and phases that are detected are often attributed qualitatively incorrect backazimuth and slowness estimates. This can result in missed events, due to either a lack of contributing phases or by corruption of event hypotheses by spurious detections. It has been demonstrated previously that continuous spectral estimation can both detect and estimate phases on the largest aperture arrays, with arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity, as is the case for classical f-k analysis, and the ability to estimate slowness vectors requires sufficiently large inter-sensor distances to resolve time-delays between pulses with a period of the order 4-5 s. Spectrogram beampacking works well on five IMS arrays with apertures over 20 km (NOA, AKASG, YKA, WRA, and KURK) without additional post-processing. Seven arrays with 10-20 km aperture (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 s period signal. Even for medium aperture arrays which can provide high-quality coherent slowness estimates, a complementary spectrogram beampacking procedure could act as a quality control by providing non-aliased estimates when the coherent slowness grids display

  12. The Applicability of Incoherent Array Processing to IMS Seismic Array Stations

    NASA Astrophysics Data System (ADS)

    Gibbons, S. J.


    The seismic arrays of the International Monitoring System for the CTBT differ greatly in size and geometry, with apertures ranging from below 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high frequency phases since signals are often incoherent between sensors. Many such phases, typically from events at regional distances, remain undetected since pipeline algorithms often consider only frequencies low enough to allow coherent array processing. High frequency phases that are detected are frequently attributed qualitatively incorrect backazimuth and slowness estimates and are consequently not associated with the correct event hypotheses. This can lead to missed events both due to a lack of contributing phase detections and by corruption of event hypotheses by spurious detections. Continuous spectral estimation can be used for phase detection and parameter estimation on the largest aperture arrays, with phase arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity and the ability to estimate backazimuth and slowness requires that the spatial extent of the array is large enough to resolve time-delays between envelopes with a period of approximately 4 or 5 seconds. The NOA, AKASG, YKA, WRA, and KURK arrays have apertures in excess of 20 km and spectrogram beamforming on these stations provides high quality slowness estimates for regional phases without additional post-processing. Seven arrays with aperture between 10 and 20 km (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 second period signal. The MJAR array in Japan recorded high SNR Pn signals for both the 2006 and 2009 North Korea