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Sample records for 2p2 1se double

  1. Electromagnetic Moments of Radioactive 136Te and the Emergence of Collectivity 2p+2n outside of Double-Magic 132Sn

    SciTech Connect

    Allmond, James M; Stuchberry, A. E.; Danchev, M.; Baktash, Cyrus; Gargano, A.; Galindo-Uribarri, Alfredo {nmn}; Radford, David C; Bingham, C. R.; Brown, Alex; Coraggio, L.; Covello, A.; Gross, Carl J; Hausladen, Paul; Itaco, N.; Lagergren, Karin B; Padilla-Rodal, Elizabeth; Pavan, John R; Riley, Mark; Stone, N. J.; Stracener, Daniel W; Varner Jr, Robert L; Yu, Chang-Hong

    2017-01-01

    Radioactive 136Te has two valence protons and two valence neutrons outside of the 132Sn double shell closure, providing a simple laboratory for exploring the emergence of collectivity and nucleon- nucleon interactions. Coulomb excitation of 136Te on a titanium target was utilized to determine an extensive set of electromagnetic moments for the three lowest-lying states, including B(E2;0+1 2+1 ), Q(2+1 ), and g(2+1 ). The results indicate that the first-excited state, 2+1 , composed of the simple 2p 2n system, is prolate deformed, and its wavefunction is dominated by neutron degrees of freedom, but not to the extent previously suggested. It is demonstrated that extreme sensitivity of g(2+1 ) to the proton and neutron contributions to the wavefunction provides unique insight into the nature of emerging collectivity, and g(2+1 ) was used to differentiate among several state-of-the-art theoretical calculations. Our results are best described by the most recent shell model calculations.

  2. Residual Chemosensory Capabilities in Double P2X2/P2X3 Purinergic Receptor Null Mice: Intraoral or Postingestive Detection?

    PubMed Central

    Hallock, Robert M.; Tatangelo, Marco; Barrows, Jennell

    2009-01-01

    Mice lacking the purinergic receptors, P2X2 and P2X3 (P2X2/P2X3Dbl−/−), exhibit essentially no tastant-evoked activity in the chorda tympani and glossopharyngeal nerves and substantial loss of tastant-evoked behavior as measured in long-term intake experiments. To assess whether the residual chemically driven behaviors in these P2X2/P2X3Dbl−/− mice were attributable to postingestive detection or oropharyngeal detection of the compounds, we used brief access lickometer tests to assess the behavioral capabilities of the P2X2/P2X3Dbl−/− animals. The P2X2/P2X3Dbl−/− mice showed avoidance to high levels (10 mM quinine and 10–30 mM denatonium benzoate) of classical “bitter”-tasting stimuli in 24-h, 2-bottle preference tests but minimal avoidance of these substances in the lickometer tests, suggesting that the strong avoidance in the intake tests was largely mediated by post-oral chemosensors. Similarly, increases in consumption of 1 M sucrose by P2X2/P2X3Dbl−/− mice in long-term intake tests were not mirrored by increases in consumption of sucrose in lickometer tests, suggesting that sucrose detection in these mice is mediated by postingestive consequences. In contrast, in brief access tests, P2X2/P2X3Dbl−/− mice avoided citric acid and hydrochloric acid at the same concentrations as their wild-type counterparts, indicating that these weak acids activate oropharyngeal chemoreceptors. PMID:19833662

  3. Double P2X2/P2X3 Purinergic Receptor Knockout Mice Do Not Taste NaCl or the Artificial Sweetener SC45647

    PubMed Central

    Eddy, Meghan C.; Eschle, Benjamin K.; Barrows, Jennell; Hallock, Robert M.; Finger, Thomas E.

    2009-01-01

    The P2X ionotropic purinergic receptors, P2X2 and P2X3, are essential for transmission of taste information from taste buds to the gustatory nerves. Mice lacking both P2X2 and P2X3 purinergic receptors (P2X2/P2X3Dbl−/−) exhibit no taste-evoked activity in the chorda tympani and glossopharyngeal nerves when stimulated with taste stimuli from any of the 5 classical taste quality groups (salt, sweet, sour, bitter, and umami) nor do the mice show taste preferences for sweet or umami, or avoidance of bitter substances (Finger et al. 2005. ATP signaling is crucial for communication from taste buds to gustatory nerves. Science. 310[5753]:1495–1499). Here, we compare the ability of P2X2/P2X3Dbl−/− mice and P2X2/P2X3Dbl+/+ wild-type (WT) mice to detect NaCl in brief-access tests and conditioned aversion paradigms. Brief-access testing with NaCl revealed that whereas WT mice decrease licking at 300 mM and above, the P2X2/P2X3Dbl−/− mice do not show any change in lick rates. In conditioned aversion tests, P2X2/P2X3Dbl−/− mice did not develop a learned aversion to NaCl or the artificial sweetener SC45647, both of which are easily avoided by conditioned WT mice. The inability of P2X2/P2X3Dbl−/− mice to show avoidance of these taste stimuli was not due to an inability to learn the task because both WT and P2X2/P2X3Dbl−/− mice learned to avoid a combination of SC45647 and amyl acetate (an odor cue). These data suggest that P2X2/P2X3Dbl−/− mice are unable to respond to NaCl or SC45647 as taste stimuli, mirroring the lack of gustatory nerve responses to these substances. PMID:19833661

  4. 2p2 Team News

    NASA Astrophysics Data System (ADS)

    Jones, H.

    2000-06-01

    The 2p2 Team continued towards the implementation at the 2.2-m of the same BOB (Broker for Observation Blocks) observing interface as seen at other ESO telescopes. This requires an interface to be written between the existing BOB software and the non-VLT compatible control software for the Wide-Field Imager (WFI) and 2.2-m. Cristian Urrutia, Tatiana Paz and Eduardo Robledo are heading its development. With this software in place, observers can use the VLT Phase 2 Proposal Preparation System (P2PP) for definition of their exposures, whether they are for Visitor or Service Mode.

  5. Faraday effect in Sn2P2S6 crystals.

    PubMed

    Krupych, Oleh; Adamenko, Dmytro; Mys, Oksana; Grabar, Aleksandr; Vlokh, Rostyslav

    2008-11-10

    We have revealed a large Faraday rotation in tin thiohypodiphosphate (Sn(2)P(2)S(6)) crystals, which makes this material promising for magneto-optics. The effective Faraday tensor component and the Verdet constant for the direction of the optic axis have been determined by measuring the pure Faraday rotation in Sn(2)P(2)S(6) crystals with both the single-ray and small-angular polarimetric methods at the normal conditions and a wavelength of 632.8 nm. The effective Verdet constant is found to be equal to 115 rad/T x m.

  6. Mini Magnetospheric Plasma Propulsion (M2P2)

    NASA Technical Reports Server (NTRS)

    Gallagher, Dennis; Winglee, Robert

    2000-01-01

    The M2P2 concept is based on the transfer of momentum from the solar wind to an artificial magnetic field structure like that naturally occurs at all magnetized planets in the Solar System, called the magnetosphere. The objectives of this program include the following: (1) Demonstrate artificial magnetospheric inflation through cold plasma filling in vacuum; (2) Demonstrate deflection of a surrogate solar wind by an artificial magnetosphere in the laboratory vacuum chamber; (3) Compare theoretical calculations for thrust forces with laboratory measurements; (4) Develop flight control algorithms for planning mission specific trajectories; and (5) Develop M2P2 system concept.

  7. Maltodextrin and fat preference deficits in "taste-blind" P2X2/P2X3 knockout mice.

    PubMed

    Sclafani, Anthony; Ackroff, Karen

    2014-07-01

    Adenosine triphosphate is a critical neurotransmitter in the gustatory response to the 5 primary tastes in mice. Genetic deletion of the purinergic P2X2/P2X3 receptor greatly reduces the neural and behavioral response to prototypical primary taste stimuli. In this study, we examined the behavioral response of P2X double knockout mice to maltodextrin and fat stimuli, which appear to activate additional taste channels. P2X double knockout and wild-type mice were given 24-h choice tests (vs. water) with ascending concentrations of Polycose and Intralipid. In Experiment 1, naive double knockout mice, unlike wild-type mice, were indifferent to dilute (0.5-4%) Polycose solutions but preferred concentrated (8-32%) Polycose to water. In a retest, the Polycose-experienced double knockout mice, like wild-type mice, preferred all Polycose concentrations. In Experiment 2, naive double knockout mice, unlike wild-type mice, were indifferent to dilute (0.313-2.5%) Intralipid emulsions but preferred concentrated (5-20%) Intralipid to water. In a retest, the fat-experienced double knockout mice, like wild-type mice, strongly preferred 0.313-5% Intralipid to water. These results indicate that the inherent preferences of mice for maltodextrin and fat are dependent upon adenosine triphosphate taste cell signaling. With experience, however, P2X double knockout mice develop strong preferences for the nontaste flavor qualities of maltodextrin and fat conditioned by the postoral actions of these nutrients.

  8. EuCo2P2: A Model Molecular-Field Helical Heisenberg Antiferromagnet

    DOE PAGES

    Sangeetha, N. S.; Cuervo-Reyes, Eduardo; Pandey, Abhishek; ...

    2016-07-19

    The metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below TN=66.5 K with the helix axis along the c axis and with the ordered moments aligned within the ab plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ, high-field magnetization, and magnetic heat capacity of EuCo2P2 single crystals at temperature T≤TNmore » with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ~T3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and BaCo2P2, respectively. These values are enhanced by a factor of ~2.5 above those found from DFT electronic structure calculations for the two compounds. Additionally, the calculations also find ferromagnetic Eu–Eu exchange interactions within the ab plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χab(T≤TN).« less

  9. EuCo2P2 : A model molecular-field helical Heisenberg antiferromagnet

    NASA Astrophysics Data System (ADS)

    Sangeetha, N. S.; Cuervo-Reyes, Eduardo; Pandey, Abhishek; Johnston, D. C.

    2016-07-01

    The metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below TN=66.5 K with the helix axis along the c axis and with the ordered moments aligned within the a b plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ , high-field magnetization, and magnetic heat capacity of EuCo2P2 single crystals at temperature T ≤TN with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ˜T3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and BaCo2P2 , respectively. These values are enhanced by a factor of ˜2.5 above those found from DFT electronic structure calculations for the two compounds. The calculations also find ferromagnetic Eu-Eu exchange interactions within the a b plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χa b(T ≤TN) .

  10. Raman spectroscopic study of (Ph 2P) 2CCH 2 and [(Ph 2P) 2CCH 2]W(CO) 4

    NASA Astrophysics Data System (ADS)

    Fickert, C.; Posset, U.; Kiefer, W.

    1997-06-01

    The Raman and IR spectra of 1,1-bis[diphenylphosphino]ethene (Ph 2P) 2CCH 2 (vdpp) and the tetracarbonyl tungsten complex (vdpp)W(CO) 4 have been recorded. Vibrational assignments are proposed based on local symmetry considerations. For the vinylidene stretching mode a coordination shift is observed from 1588 cm -1 in polycrystalline vdpp to 1581 cm -1 in its tetracarbonyl tungsten complex. From a comparison of the v(CO) splitting pattern with those of related complexes monoclinic structure with factor group C2h and four formula units per unit cell is concluded.

  11. Large-Scale Mini-Magnetosphere Plasma Propulsion (M2P2) Experiments

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Slough, J.; Ziemba, T.; Euripides, P.; Adrian, M. L.; Gallagher, D.; Craven, P.; Tomlinson, W.; Cravens, J.; Burch, J.; hide

    2001-01-01

    Mini-Magnetosphere Plasma Propulsion (M2P2) is an innovative plasma propulsion system that has the potential to propel spacecraft at unprecedented speeds of 50 to 80 km per second with a low-power requirement of approx. 1 kW per 100 kg of payload and approx. 1 kg of neutral gas [fuel] consumption per day of acceleration. Acceleration periods from several days to a few months are envisioned. High specific impulse and efficiency are achieved through coupling of the spacecraft to the 400 km per second solar wind through an artificial magnetosphere. The mini-magnetosphere or inflated magnetic bubble is produced by the injection of cold dense plasma into a spacecraft-generated magnetic field envelope. Magnetic bubble inflation is driven by electromagnetic processes thereby avoiding the material and deployment problems faced by mechanical solar sail designs, Here, we present the theoretical design of M2P2 as well as initial results from experimental testing of an M2P2 prototype demonstrating: 1) inflation of the dipole magnetic field geometry through the internal injection of cold plasma; and 2) deflection of and artificial solar wind by the prototype M2P2 system. In addition, we present plans for direct laboratory measurement of thrust imparted to a prototype M2P2 by an artificial solar wind during the summer of 2001.

  12. Large-Scale Mini-Magnetosphere Plasma Propulsion (M2P2) Experiments

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Slough, J.; Ziemba, T.; Euripides, P.; Gallagher, D.; Craven, P.; Adrian, M. L.; Tomlinson, W.; Cravens, J.; Burch, J.; hide

    2001-01-01

    Mini-Magnetosphere Plasma Propulsion (M2P2) is an innovative plasma propulsion system that has the potential to propel spacecraft at unprecedented speeds of 50 to 80 km/s, with a low power requirement of approx. 1 kW per 100 kg of payload and -1 kg of neutral gas [fuel] consumption per day of acceleration. Acceleration periods from several days to a few months are envisioned. High specific impulse and efficiency are achieved through coupling of the spacecraft to the 400 km/s. solar wind through an artificial magnetosphere. The mini-magnetosphere or inflated magnetic bubble is produced by the injection of cold dense plasma into a spacecraft-generated magnetic field envelope. Magnetic bubble inflation is driven by electromagnetic processes thereby avoiding the material and deployment problems faced by mechanical solar sail designs. Here, we present the theoretical design of M2P2 as well as initial results from experimental testing of an M2P2 prototype demonstrating: 1) inflation of the dipole magnetic field geometry through the internal injection of cold plasma; and 2) deflection of and artificial solar wind by the prototype M2P2 system. In addition, we present plans for direct laboratory measurement of thrust imparted to a prototype M2P2 by an artificial solar wind during the summer of 2001.

  13. Large-Scale Mini-Magnetosphere Plasma Propulsion (M2P2) Experiments

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Slough, J.; Ziemba, T.; Euripides, P.; Adrian, M. L.; Gallagher, D.; Craven, P.; Tomlinson, W.; Cravens, J.; Burch, J.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Mini-Magnetosphere Plasma Propulsion (M2P2) is an innovative plasma propulsion system that has the potential to propel spacecraft at unprecedented speeds of 50 to 80 km per second with a low-power requirement of approx. 1 kW per 100 kg of payload and approx. 1 kg of neutral gas [fuel] consumption per day of acceleration. Acceleration periods from several days to a few months are envisioned. High specific impulse and efficiency are achieved through coupling of the spacecraft to the 400 km per second solar wind through an artificial magnetosphere. The mini-magnetosphere or inflated magnetic bubble is produced by the injection of cold dense plasma into a spacecraft-generated magnetic field envelope. Magnetic bubble inflation is driven by electromagnetic processes thereby avoiding the material and deployment problems faced by mechanical solar sail designs, Here, we present the theoretical design of M2P2 as well as initial results from experimental testing of an M2P2 prototype demonstrating: 1) inflation of the dipole magnetic field geometry through the internal injection of cold plasma; and 2) deflection of and artificial solar wind by the prototype M2P2 system. In addition, we present plans for direct laboratory measurement of thrust imparted to a prototype M2P2 by an artificial solar wind during the summer of 2001.

  14. Large-Scale Mini-Magnetosphere Plasma Propulsion (M2P2) Experiments

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Slough, J.; Ziemba, T.; Euripides, P.; Gallagher, D.; Craven, P.; Adrian, M. L.; Tomlinson, W.; Cravens, J.; Burch, J.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Mini-Magnetosphere Plasma Propulsion (M2P2) is an innovative plasma propulsion system that has the potential to propel spacecraft at unprecedented speeds of 50 to 80 km/s, with a low power requirement of approx. 1 kW per 100 kg of payload and -1 kg of neutral gas [fuel] consumption per day of acceleration. Acceleration periods from several days to a few months are envisioned. High specific impulse and efficiency are achieved through coupling of the spacecraft to the 400 km/s. solar wind through an artificial magnetosphere. The mini-magnetosphere or inflated magnetic bubble is produced by the injection of cold dense plasma into a spacecraft-generated magnetic field envelope. Magnetic bubble inflation is driven by electromagnetic processes thereby avoiding the material and deployment problems faced by mechanical solar sail designs. Here, we present the theoretical design of M2P2 as well as initial results from experimental testing of an M2P2 prototype demonstrating: 1) inflation of the dipole magnetic field geometry through the internal injection of cold plasma; and 2) deflection of and artificial solar wind by the prototype M2P2 system. In addition, we present plans for direct laboratory measurement of thrust imparted to a prototype M2P2 by an artificial solar wind during the summer of 2001.

  15. Competing analysis of α and 2p2n-emission from compound nuclei formed in neutron induced reactions

    NASA Astrophysics Data System (ADS)

    Kaur, Amandeep; Sharma, Manoj K.

    2017-01-01

    The decay mechanism of compound system 61Ni* formed in fast neutron induced reactions is explored within the collective clusterization approach of the Dynamical Cluster-decay Model (DCM) in reference to a recent experiment over an energy spread of En = 1- 100 MeV. The excitation functions for the decay of the compound nucleus 61Ni* formed in the n +60Ni reaction show a double humped variation with incident beam energy where the peak at lower energy corresponds to α-emission while the one at higher energy originates from 2 p 2 n-emission. The experimentally observed transmutation of α-emission at lower energy into 2 p 2 n-emission at higher incident energies is explained on the basis of temperature dependence of the binding energies used within the framework of DCM. The cross-sections for the formation of the daughter nucleus 57Fe after emission of α-cluster from the 61Ni* nucleus are addressed by employing the neck length parameter (ΔR), finding decent agreement with the available experimental data. The calculations are done for non-sticking choice of moment of inertia (INS) in the centrifugal potential term, which forms the essential ingredient in DCM based calculations. In addition to this, the effect of mass (and charge) of the compound nucleus is exercised in view of α and 2 p 2 n emission and comparative study of the decay profiles of compound systems with mass A = 17-93 is employed to get better description of decay patterns.

  16. Highly efficient acousto-optic diffraction in Sn2P2S6 crystals.

    PubMed

    Martynyuk-Lototska, I Yu; Mys, O G; Grabar, A A; Stoika, I M; Vysochanskii, Yu M; Vlokh, R O

    2008-01-01

    We have studied the acousto-optic (AO) diffraction in Sn2P2S6 crystals and found that they manifest high values of an AO figure of merit. The above crystals may therefore be used as highly efficient materials in different AO applications.

  17. A study of a sector spectrophotometer and auroral O+(2P-2D) emissions

    NASA Technical Reports Server (NTRS)

    Swenson, G. R.

    1976-01-01

    The metastable O+(2P-2D) auroral emission was investigated. The neighboring OH contaminants and low intensity levels of the emission itself necessitated the evolution of an instrument capable of separating the emission from the contaminants and having a high sensitivity in the wavelength region of interest. A new type of scanning photometer was developed and its properties are discussed. The theoretical aspects of auroral electron interaction with atomic oxygen and the resultant O+(2P-2D) emissions were examined in conjunction with N2(+)1NEG emissions. Ground based measurements of O+(2P-2D) auroral emission intensities were made using the spatial scanning photometer (sector spectrophotometer). Simultaneous measurements of N2(+)1NEG sub 1,0 emission intensity were made in the same field of view using a tilting photometer. Time histories of the ratio of these two emissions made in the magnetic zenith during auroral breakup periods are given. Theories of I sub 7319/I sub 4278 of previous investigators were presented. A rocket measurement of N2(+)1NEG sub 0,0 and O+(2P-2D) emission in aurora was examined in detail and was found to agree with the ground based measurements. Theoretical examination resulted in the deduction of the electron impact efficiency generating O+(2P) and also suggests a large source of O+(2P) at low altitude. A possible source is charge exchange of N+(1S) with OI(3P).

  18. K2P2: Reduced data from campaigns 0-4 of the K2 mission

    NASA Astrophysics Data System (ADS)

    Handberg, R.; Lund, M. N.

    2017-01-01

    Context. After the loss of a second reaction wheel the Kepler mission was redesigned as the K2 mission, pointing towards the ecliptic and delivering data for new fields approximately every 80 days. The steady flow of data obtained with a reduced pointing stability calls for dedicated pipelines for extracting light curves and correcting these for use in, e.g., asteroseismic analysis. Aims: We provide corrected light curves for the K2 fields observed until now (campaigns 0-4), and provide a comparison with other pipelines for K2 data extraction/correction. Methods: Raw light curves are extracted from K2 pixel data using the "K2-pixel-photometry" (K2P2) pipeline, and corrected using the KASOC filter. Results: The use of K2P2 allows for the extraction of the order of 90 000 targets in addition to 70 000 targets proposed by the community - for these, other pipelines provide no data. We find that K2P2 in general performs as well as, or better than, other pipelines for the tested metrics of photometric quality. In addition to stars, pixel masks are properly defined using K2P2 for extended objects such as galaxies for which light curves are also extracted.

  19. Atomic Analysis of Protein-Protein Interfaces with Known Inhibitors: The 2P2I Database

    PubMed Central

    Bourgeas, Raphaël; Basse, Marie-Jeanne

    2010-01-01

    Background In the last decade, the inhibition of protein-protein interactions (PPIs) has emerged from both academic and private research as a new way to modulate the activity of proteins. Inhibitors of these original interactions are certainly the next generation of highly innovative drugs that will reach the market in the next decade. However, in silico design of such compounds still remains challenging. Methodology/Principal Findings Here we describe this particular PPI chemical space through the presentation of 2P2IDB, a hand-curated database dedicated to the structure of PPIs with known inhibitors. We have analyzed protein/protein and protein/inhibitor interfaces in terms of geometrical parameters, atom and residue properties, buried accessible surface area and other biophysical parameters. The interfaces found in 2P2IDB were then compared to those of representative datasets of heterodimeric complexes. We propose a new classification of PPIs with known inhibitors into two classes depending on the number of segments present at the interface and corresponding to either a single secondary structure element or to a more globular interacting domain. 2P2IDB complexes share global shape properties with standard transient heterodimer complexes, but their accessible surface areas are significantly smaller. No major conformational changes are seen between the different states of the proteins. The interfaces are more hydrophobic than general PPI's interfaces, with less charged residues and more non-polar atoms. Finally, fifty percent of the complexes in the 2P2IDB dataset possess more hydrogen bonds than typical protein-protein complexes. Potential areas of study for the future are proposed, which include a new classification system consisting of specific families and the identification of PPI targets with high druggability potential based on key descriptors of the interaction. Conclusions 2P2I database stores structural information about PPIs with known inhibitors and

  20. Vapor-phase synthesis of mesoporous SiO2-P2O5 thin films.

    PubMed

    Nishiyama, Norikazu; Kaihara, Junji; Nishiyama, Yuko; Egashira, Yasuyuki; Ueyama, Korekazu

    2007-04-24

    Mesoporous SiO2-P2O5 films were synthesized from the vapor phase onto a silicon substrate. First, a precursor solution of cetyltrimethylammonium bromide (C16TAB), H3PO4, ethanol, and water was deposited on a silicon substrate by a spin-coating method. Then, the C16TAB-H3PO4 composite film was treated with tetraethoxysilane (TEOS) vapor at 90-180 degrees C for 2.5 h. The H3PO4-C16TAB composite formed a hexagonal structure on the silicon substrate before vapor treatment. The TEOS molecules penetrated into the film without a phase transition. The periodic mesostructure of the SiO2-P2O5 films was retained after calcination. The calcined films showed a high proton conductivity of about 0.55 S/cm at room temperature. The molar ratio of P/Si in the SiO2-P2O5 film was as high as 0.43, a level that was not attained by a premixing sol-gel method. The high phosphate group content and the ordered periodic mesostructure contributed to the high proton conductivity.

  1. Pre-stimulus alpha power affects vertex N2-P2 potentials evoked by noxious stimuli.

    PubMed

    Babiloni, Claudio; Del Percio, Claudio; Brancucci, Alfredo; Capotosto, Paolo; Le Pera, Domenica; Marzano, Nicola; Valeriani, Massimiliano; Romani, Gian Luca; Arendt-Nielsen, Lars; Rossini, Paolo Maria

    2008-03-28

    It is well known that scalp potentials evoked by nonpainful visual and auditory stimuli are enhanced in amplitude when preceded by pre-stimulus low-amplitude alpha rhythms. This study tested the hypothesis that the same holds for the amplitude of vertex N2-P2 potentials evoked by brief noxious laser stimuli, an issue of interest for clinical perspective. EEG data were recorded in 10 subjects from 30 electrodes during laser noxious stimulation. The artifact-free vertex N2-P2 complex was spatially enhanced by surface Laplacian transformation. Pre-stimulus alpha power was computed at three alpha sub-bands according to subject's individual alpha frequency peak (i.e. about 6-8Hz for alpha 1, 8-10Hz for alpha 2 and 10-12Hz for alpha 3 sub-band). Individual EEG single trials were divided in two sub-groups. The strong-alpha sub-group (high band power) included halfway of all EEG single trials, namely those having the highest pre-stimulus alpha power. Weak-alpha sub-group (low band power) included the remaining trials. Averaging procedure provided laser evoked potentials for both trial sub-groups. No significant effect was found for alpha 1 and alpha 2 sub-bands. Conversely, compared to strong-alpha 3 sub-group, weak-alpha 3 sub-group showed vertex N2-P2 potentials having significantly higher amplitude (p<0.05). These results extend to the later phases of pain processing systems the notion that generation mechanisms of pre-stimulus alpha rhythms and (laser) evoked potentials are intrinsically related and subjected to fluctuating "noise". That "noise" could explain the trial-by-trial variability of laser evoked potentials and perception.

  2. Acoustic and elastic properties of Sn(2)P(2)S(6) crystals.

    PubMed

    Mys, O; Martynyuk-Lototska, I; Grabar, A; Vlokh, R

    2009-07-01

    We present the results concerned with acoustic and elastic properties of Sn(2)P(2)S(6) crystals. The complete matrices of elastic stiffness and compliance coefficients are determined in both the crystallographic coordinate system and the system associated with eigenvectors of the elastic stiffness tensor. The acoustic slowness surfaces are constructed and the propagation and polarization directions of the slowest acoustic waves promising for acousto-optic interactions are determined on this basis. The acoustic obliquity angle and the deviation of polarization of the acoustic waves from purely transverse or longitudinal states are quantitatively analysed.

  3. Pressure Induced Enhancement of Superconductivity in LaRu2P2

    PubMed Central

    Li, Baoxuan; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-01-01

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan’s theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors. PMID:27086696

  4. Pressure Induced Enhancement of Superconductivity in LaRu2P2.

    PubMed

    Li, Baoxuan; Lu, Pengchao; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-04-18

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan's theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors.

  5. CCQE, 2p2h excitations and ν—energy reconstruction

    SciTech Connect

    Nieves, J.; Simo, I. Ruiz; Sánchez, F.; Vacas, M. J. Vicente

    2015-05-15

    We analyze the MiniBooNE muon neutrino CCQE-like dσ/dT{sub μ} d cos θ{sub μ} data using a theoretical model that, among other nuclear effects, includes RPA correlations and 2p2h (multinucleon) mechanisms. These corrections turn out to be essential for the description of the data. We find that MiniBooNE CCQE-like data are fully compatible with former determinations of the nucleon axial mass M{sub A} ∼ 1.05 GeV. This is in sharp contrast with several previous analysis where anomalously large values of M{sub A} ∼ 1.4 GeV have been suggested. We also show that because of the the multinucleon mechanism effects, the algorithm used to reconstruct the neutrino energy is not adequate when dealing with quasielastic-like events. Finally, we analyze the MiniBooNE unfolded cross section, and show that it exhibits an excess (deficit) of low (high) energy neutrinos, which is an artifact of the unfolding process that ignores 2p2h mechanisms.

  6. Ferromagnetism in the Kondo-lattice compound CePd2P2.

    PubMed

    Tran, Vinh Hung; Bukowski, Zbigniew

    2014-06-25

    We report physical properties of CePd2P2 crystallizing in the tetragonal ThCr2Si2-type structure (space group I4/mmm). Dc-magnetic susceptibility, magnetization, specific heat, electrical resistivity and magnetoresistance measurements establish a ferromagnetic ordering below the Curie temperature TC = 28.4 ± 0.2 K. Critical analysis of isothermal and isofield magnetization yields critical exponents of β = 0.405 ± 0.005, γ = 1.11 ± 0.05 and δ = 3.74 ± 0.04. The ordered state is characterized by saturation moment Ms ∼ 0.98μB and magnon energy gap Δ/kB ∼25–35 K. The studied properties reflect a competing influence of the Kondo and crystalline electric field (CEF) interactions. The strength of the Kondo effect is assigned by a low-temperature Kondo scale TK ∼19 ± 10 K and a high-temperature Kondo scale TK ~ H 117 } 10 K. A model of the inelastic scattering of the conduction electrons with an exchanged CEF energy ΔCEF was applied to the magnetic resistivity. An average value ΔCEF = 260 ± 30 K is consistent in the relationships with TK and TK H. We argue that the CePd2P2 compound appears to be a new ferromagnetic Kondo-lattice among the Ce-based intermetallics.

  7. Pressure Induced Enhancement of Superconductivity in LaRu2P2

    NASA Astrophysics Data System (ADS)

    Li, Baoxuan; Lu, Pengchao; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-04-01

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan’s theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors.

  8. Fermi Surface of the Pnictide Superconductor LaRu2 P 2 studied by quantum oscillations

    NASA Astrophysics Data System (ADS)

    Moll, Philip; Balakirev, Fedor; McDonald, Ross; Karpinski, Janusz; Bukowski, Zbigniew; Blaha, Peter; Schwarz, Karlheinz; Batlogg, Bertram

    2011-03-01

    LaRu 2 P2 is a stochiometric pnictide superconductor (Tc ~ 4.1 K) and crystallizes in the ThCr 2 Si 2 structure (the ``122'' pnictide family). We have mapped out its Fermi surface via the deHaas-vanAlphen effect in pulsed magnetic fields up to 60T (LANL/NHMFL). Pronounced oscillations were observed in the magnetic torque measured with a microcantilever setup. Two features are particularly noteworthy: The oscillations can be followed to surprisingly high temperatures beyond 20K, and the main frequency component at θ = 20circ; (θ = 0circ; at HIIc) is at 349T (α -peak), significantly lower than in the related compounds LaFe 2 P2 . A second frequency originating from a larger Fermi surface cross-section at 1921 T (β -peak) is identified. The temperature dependence of the amplitudes is well described by the Lifshitz- Kosevich formalism and gives low effective masses m*/m = 0.80 (α sheet) and 1.09 (β sheet). Therefore, most ``122'' metals appear to have similarly low effective masses.

  9. Electron-phonon interaction and superconductivity in BaIr2P2

    NASA Astrophysics Data System (ADS)

    Billington, D.

    2016-10-01

    Detailed calculations of the electronic structure, phonons and electron-phonon coupling of the superconducting compound BaIr2P2 were performed from first-principles. The electronic structure showed excellent agreement with the available experimental data. The total electron-phonon coupling constant was {λ\\text{ep}}=0.52 and the logarithmically averaged phonon frequency was \\hbar {ω\\text{log}}/{{k}\\text{B}}=168 K. From the Allen-Dynes formula, with {μ\\ast}=0.11 , the superconducting critical temperature was estimated to be {{T}\\text{c}}=2.05 K, which is in excellent agreement with the experiment. These results indicate that the electron-phonon coupling is of moderate strength and is easily capable of supporting the observed superconductivity.

  10. α and 2 p 2 n emission in fast neutron-induced reactions on 60Ni

    NASA Astrophysics Data System (ADS)

    Fotiades, N.; Devlin, M.; Haight, R. C.; Nelson, R. O.; Kunieda, S.; Kawano, T.

    2015-06-01

    Background: The cross sections for populating the residual nucleus in the reaction ZAX(n,x) Z -2 A -4Y exhibit peaks as a function of incident neutron energy corresponding to the (n ,n'α ) reaction and, at higher energy, to the (n ,2 p 3 n ) reaction. The relative magnitudes of these peaks vary with the Z of the target nucleus. Purpose: Study fast neutron-induced reactions on 60Ni. Locate experimentally the nuclear charge region along the line of stability where the cross sections for α emission and for 2 p 2 n emission in fast neutron-induced reactions are comparable as a further test of reaction models. Methods: Data were taken by using the Germanium Array for Neutron-Induced Excitations. The broad-spectrum pulsed neutron beam of the Los Alamos Neutron Science Center's Weapons Neutron Research facility provided neutrons in the energy range from 1 to 250 MeV. The time-of-flight technique was used to determine the incident-neutron energies. Results: Absolute partial cross sections for production of seven discrete Fe γ rays populated in 60Ni (n ,α /2 p x n γ ) reactions with 2 ≤x ≤5 were measured for neutron energies 1 MeV2 p 2 n and 2 p 3 n emission at higher incident energies in the nuclear charge region around Fe.

  11. Optical Sensitizing of Photorefractive Sn2P2S6 With CW and Pulsed Pre-Exposure (Preprint)

    DTIC Science & Technology

    2015-06-16

    antimony doping. The second conclusion is in line with our published data on the identification of secondary centers in Sn2P2S6:Sb using the EPR...optical sensitizing of photorefraction in antimony doped Sn2P2S6 crystals. AKNOWLEDGMENTS The financial support of the European Office of

  12. Crystal structure and vibrational spectra of tetrasodium dimagnesium dihydrogen diphosphate octahydrate Na 4Mg 2(H 2P 2O 7) 4·8H 2O

    NASA Astrophysics Data System (ADS)

    Harcharras, M.; Ennaciri, A.; Assaaoudi, H.; Mattei, G.; D'Orazio, V.; Moliterni, A. G. G.; Capitelli, F.

    2003-04-01

    A tetrasodium dimagnesium dihydrogen diphosphate octahydrate Na 4Mg 2(H 2P 2O 7) 4·8H 2O was synthesized. It crystallizes in the monoclinic system, space group P2 1/ m (no. 11), Z=4, and its unit-cell parameters are: a=8.0445(3) Å, b=11.5244(5) Å, c=9.0825(4) Å, β=113.1401(2)°, V=774.28(6) Å 3. The structure was determined by single-crystal X-ray diffractometry and refined to a R index of 0.0294 (w R=0.0727) for 1878 independent reflections with I>2 σ( I). The framework is made by the alternance of layers of MgO 6/NaO 6 octahedra and double tetrahedra PO 4 along b-axis. Such layers are characterized by the presence of strong hydrogen bonds. (H 2P 2O 7) 2- anions exhibit bent eclipsed conformation. Besides, the crystal was analyzed by FT-IR and micro-Raman vibrational spectroscopy. No coincidences of the majority of the Raman and infrared spectra bands of Na 4Mg 2(H 2P 2O 7) 4·8H 2O confirms a centrosymmetric structure of this material. The vibrational spectra confirm the bent POP configuration in this compound.

  13. Efficient Plasma Production in Low Background Neutral Pressures with the M2P2 Prototype

    NASA Technical Reports Server (NTRS)

    Ziemba, T.; Euripides, P.; Winglee, R.; Slough, J.; Giersch, L.

    2003-01-01

    Mini-Magnetospheric Plasma Propulsion (M2P2) seeks the creation of a large-scale (10 km radius) magnetic wall or bubble (i.e. a magnetosphere) by the electromagnetic inflation of a small-scale (20 cm radius) dipole magnet. The inflated magnetosphere will intercept the solar wind and thereby provide high-speed propulsion with modest power and fuel requirements due to the gain provided by the ambient medium. Magnetic field inflation is produced by the injection of plasma onto the dipole magnetic field eliminating the need for large mechanical structures and added material weight at launch. For successful inflation of the magnetic bubble a beta near unity must be achieved along the imposed dipole field. This is dependent on the plasma parameters that can be achieved with a plasma source that provide continuous operation at the desired power levels of 1 to 2 kilowatts. Over the last two years we have been developing a laboratory prototype to demonstrate the inflation of the magnetic field under space-like conditions. In this paper we will present some of the latest results from the prototype development at the University of Washington and show that the prototype can produce high ionization efficiencies while operating in near space like neutral background pressures producing electron temperatures of a few tens of electron volts. This allows for operation with propellant expenditures lower than originally estimated.

  14. NMR study of heavy fermion compound EuNi2P2

    NASA Astrophysics Data System (ADS)

    Magishi, K.; Watanabe, R.; Hisada, A.; Saito, T.; Koyama, K.; Fujiwara, T.

    2015-03-01

    We report the results of 31P-nuclear magnetic resonance (NMR) measurements on heavy fermion compound EuNi2P2 in order to investigate the magnetic properties at low temperatures from a microscopic view point. The Knight shift has a negative value in an entire temperature range, and the absolute value increases with decreasing temperature but exhibits a broad maximum around 40 K, which is similar to the behavior of the magnetic susceptibility. Also, the nuclear spin-lattice relaxation rate 1/T1 is almost constant at high temperatures above 200 K, which is reminiscent of the relaxation mechanism dominated by the interaction of the 31P nucleus with fluctuating Eu-4f moments. Below 200 K, 1/T1 gradually decreases on cooling due to the change of the valence in the Eu ion. At low temperatures, 1/T1 does not obey the Korringa relation, in contrast to typical heavy fermion compounds. The nuclear spin-spin relaxation rate 1/T2 shows the similar behavior as 1/T1 at high temperatures. But, below 50 K, 1/T2 increases upon cooling due to the development of the magnetic excitation.

  15. Relativistic model of 2p-2h meson exchange currents in (anti)neutrino scattering

    NASA Astrophysics Data System (ADS)

    Ruiz Simo, I.; E Amaro, J.; Barbaro, M. B.; De Pace, A.; Caballero, J. A.; Donnelly, T. W.

    2017-06-01

    We develop a model of relativistic, charged meson-exchange currents (MEC) for neutrino-nucleus interactions. The two-body current is the sum of seagull, pion-in-flight, pion-pole and Δ-pole operators. These operators are obtained from the weak pion-production amplitudes for the nucleon derived in the nonlinear σ-model together with weak excitation of the {{Δ }}(1232) resonance and its subsequent decay into Nπ . With these currents we compute the five 2p-2h response functions contributing to ({ν }l,{l}-) and ({\\overline{ν }}l,{l}+) reactions in the relativistic Fermi gas model. The total current is the sum of vector and axial two-body currents. The vector current is related to the electromagnetic MEC operator that contributes to electron scattering. This allows one to check our model by comparison with the results of De Pace et al (2003 Nucl. Phys. A 726 303). Thus, our model is a natural extension of that model to the weak sector with the addition of the axial MEC operator. The dependences of the response functions on several ingredients of the approach are analyzed. Specifically we discuss relativistic effects, quantify the size of the direct-exchange interferences, and the relative importance of the axial versus vector current.

  16. Complex magnetic phase diagram with multistep spin-flop transitions in L a0.25P r0.75C o2P2

    NASA Astrophysics Data System (ADS)

    Tan, Xiaoyan; Garlea, V. Ovidiu; Kovnir, Kirill; Thompson, Corey M.; Xu, Tongshuai; Cao, Huibo; Chai, Ping; Tener, Zachary P.; Yan, Shishen; Xiong, Peng; Shatruk, Michael

    2017-01-01

    L a0.25P r0.75C o2P2 crystallizes in the tetragonal ThC r2S i2 structure type and shows multiple magnetic phase transitions driven by changes in temperature and magnetic field. The nature of these transitions was investigated by a combination of magnetic and magnetoresistance measurements and both single crystal and powder neutron diffraction. The Co magnetic moments order ferromagnetically (FM) parallel to the c axis at 282 K, followed by antiferromagnetic (AFM) ordering at 225 K. In the AFM structure, the Co magnetic moments align along the c axis with FM [C o2P2] layers arranged in an alternating sequence, ↑↑↓↓ , which leads to the doubling of the c axis in the magnetic unit cell. Another AFM transition is observed at 27 K, due to the ordering of a half of Pr moments in the a b plane. The other half of Pr moments undergoes AFM ordering along the c axis at 11 K, causing simultaneous reorientation of the previously ordered Pr moments into an AFM structure with the moments being canted with respect to the c axis. This AFM transition causes an abrupt decrease in electrical resistivity at 11 K. Under applied magnetic field, two metamagnetic transitions are observed in the Pr sublattice at 0.8 and 5.4 T. They correlate with two anomalies in magnetoresistance measurements at the same critical fields. A comparison of the temperature- and field-dependent magnetic properties of L a0.25P r0.75C o2P2 to the magnetic behavior of PrC o2P2 is provided.

  17. A tetragonal polymorph of SrMn2P2 made under high pressure - theory and experiment in harmony.

    PubMed

    Xie, Weiwei; Winiarski, Michał J; Klimczuk, Tomasz; Cava, R J

    2017-05-30

    Following the predictions of total energy calculations, a tetragonal SrMn2P2 phase is proposed and successfully formed under high pressure. At ambient pressure, SrMn2P2 adopts the primitive trigonal La2O3 structure type (space group P3[combining macron]m1). However, the results of total energy calculations indicate that SrMn2P2 should be more stable in the tetragonal ThCr2Si2 structure type (space group I4/mmm) than in its known trigonal structure, thus motivating our synthetic experiments. Guided by these calculations, a new tetragonal polymorph of SrMn2P2 was found under the relatively mild conditions of 5 GPa applied pressure at a temperature of 900 °C through the transformation of the ambient pressure trigonal form. The new polymorph has the body centered tetragonal ThCr2Si2 structure type, as predicted. The electronic structure calculations indicate the likelihood of antiferromagnetic, semiconducting properties for the high pressure SrMn2P2 phase.

  18. Simulation of Mini-Magnetospheric Plasma Propulsion (M2P2) Interacting with an External Plasma Wind

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Euripides, P.; Ziemba, T.; Slough, J.; Giersch, L.

    2003-01-01

    Substantial progress has been made over the last year in the development of the laboratory Mini-Magnetospheric Plasma Propulsion (M2P2) prototype. The laboratory testing has shown that that the plasma can be produced at high neutral gas efficiency, at high temperatures (a few tens of eV) with excellent confinement up to the point where chamber wall interactions dominate the physics. This paper investigates the performance of the prototype as it is opposed by an external plasma acting as a surrogate for the solar wind. The experiments were performed in 5ft diameter by 6ft long vacuum chamber at the University of Washington. The solar wind source comprised of a 33 kWe arc jet attached to a 200 kWe inductively generated plasma source. The dual plasma sources allow the interaction to be studied for different power levels, shot duration and production method. It is shown that plasma from the solar wind source (SWS) is able to penetrate the field of the M2P2 magnetic when no plasma is present. With operation of the M2P2 plasma source at only 1.5 kWe, the penetration of the SWS even at the highest power of operation at 200 kWe is stopped. This deflection is shown to be greatly enhanced over that produced by the magnet alone. In addition it is shown that with the presence of the SWS, M2P2 is able to produce enhanced magnetized plasma production out to at least 10 magnet radii where the field strength is only marginally greater than the terrestrial field. The results are consistent with the initial predictions that kWe M2P2 systems would be able to deflect several hundred kWe plasma winds to produce enhanced propulsion for a spacecraft.

  19. 2P2Idb v2: update of a structural database dedicated to orthosteric modulation of protein–protein interactions

    PubMed Central

    Basse, Marie-Jeanne; Betzi, Stéphane; Morelli, Xavier; Roche, Philippe

    2016-01-01

    2P2Idb is a hand-curated structural database dedicated to protein–protein interactions with known small molecule orthosteric modulators. It compiles the structural information related to orthosteric inhibitors and their target [i.e. related 3D structures available in the RCSB Protein Data Bank (PDB)] and provides links to other useful databases. 2P2Idb includes all interactions for which both the protein–protein and protein–inhibitor complexes have been structurally characterized. Since its first release in 2010, the database has grown constantly and the current version contains 27 protein–protein complexes and 274 protein–inhibitor complexes corresponding to 242 unique small molecule inhibitors which represent almost a 5-fold increase compared to the previous version. A number of new data have been added, including new protein–protein complexes, binding affinities, molecular descriptors, precalculated interface parameters and links to other webservers. A new query tool has been implemented to search for inhibitors within the database using standard molecular descriptors. A novel version of the 2P2I-inspector tool has been implemented to calculate a series of physical and chemical parameters of the protein interfaces. Several geometrical parameters including planarity, eccentricity and circularity have been added as well as customizable distance cutoffs. This tool has also been extended to protein–ligand interfaces. The 2P2I database thus represents a wealth of structural source of information for scientists interested in the properties of protein–protein interactions and the design of protein–protein interaction modulators. Database URL: http://2p2idb.cnrs-mrs.fr PMID:26980515

  20. Unconventional magnetism in ThCr2Si2-type phosphides, La1 xNdxCo2P2

    SciTech Connect

    Thompson, Corey; Kovnir, Kirill; Garlea, Vasile O; Choi, E.; Zhou, Haidong; Shatruk, Michael

    2014-01-01

    Quaternary phases La1 xNdxCo2P2 (x = 0, 0.12, 0.25, 0.37, 0.50, 0.63, 0.75, 0.88, 1.0) have been synthesized from Sn flux to investigate the origins of drastic differences in properties between ferromagnetic LaCo2P2 and antiferromagnetic NdCo2P2. Powder and single-crystal X-ray diffraction indicate that all La1 xNdxCo2P2 samples are isostructural and crystallize in the ThCr2Si2 structure type. The unit cell parameters and volume change non-linearly with the Nd content (x), with the x < 0.50 10 samples being closer to LaCo2P2 and the ones with x > 0.50 being closer to NdCo2P2. These structural differences are also reflected in the magnetic behavior. The samples with lower Nd content are characterized by ferromagnetic ordering in the Co sublattice with the TC increasing from 132 K for x = 0 to 262 K for x = 0.50, while the samples with higher Nd content exhibit suppressed magnetization in the Co sublattice and canted antiferromagnetic ordering with TC ~ 270 K. Refinement of neutron powder 15 diffraction patterns for x = 0.50 and 0.75 reveals a gradual ordering of the Nd 4f moments under the influence of Co 3d moments below 100 K. At low temperatures and zero field, these samples exhibit antiferromagnetic ordering of both Nd and Co magnetic moments, but under applied field they demonstrate the stabilization of a ferrimagnetic state with antiparallel alignment of the 4f and 3d moments, as indicated by isothermal magnetization measurements. The re-entrant ferrimagnetic transition 20 is also observed in samples with x > 0.50 if the temperature is lowered below 5 K. The occurrence of this low-temperature magnetic transition was confirmed by alternating-current susceptibility measurements.

  1. Nqrs Data for C24H46I2N6O2P2Sn (Subst. No. 1589)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H46I2N6O2P2Sn (Subst. No. 1589)

  2. Enhanced Superconductivity in Close Proximity to the Structural Phase Transition of Sr1-xBaxNi2P2

    NASA Astrophysics Data System (ADS)

    Kudo, Kazutaka; Kitahama, Yutaka; Iba, Keita; Takasuga, Masaya; Nohara, Minoru

    2017-03-01

    The structural evolution and superconductivity of a 122-type solid solution Sr1-xBaxNi2P2 were studied. We found that an orthorhombic-tetragonal structural phase transition takes place at x = 0.5, and is characterized by the P-P dimers breaking. The superconducting transition temperature exhibited its highest value of 2.85 K at x = 0.4.

  3. Synthesis of β-Ca2P2O7:Tb(3+) to gamma radiation detection by thermoluminescence.

    PubMed

    Roman-Lopez, J; Lozano, I B; Cruz-Zaragoza, E; Castañeda, J I Guzman; Díaz-Góngora, J A I

    2017-03-06

    In this work, luminescent emissions of beta-calcium pyrophosphate doped with terbium ions (β-Ca2P2O7:Tb(3+)) were studied. The Ca2P2O7:Tb(3+) powders were prepared by precipitation and annealed at 900°C for 2h was applied on the powders to observe the beta phase. Radioluminescence measurements showed emission bands related with (5)D3 ((5)D4)→(7)FJ transitions of Tb(3+) ions. Three overlapped peaks at 126, 165 and 220°C were observed in thermoluminescence response. A linear TL dose-response in the range of 0.2-10Gy and an acceptable TL reproducibility were showed by the β-Ca2P2O7:Tb(3+) samples exposed to (60)Co gamma radiation. The TL glow curves were analyzed by Initial Rise method and Computational Glow-Curve Deconvolution assuming a General Order Kinetic model to evaluate the kinetic parameters related with the TL peaks.

  4. Electronic structure and defect properties of selenophosphate Pb2P2Se6 for γ-ray detection

    NASA Astrophysics Data System (ADS)

    Kontsevoi, Oleg Y.; Im, Jino; Wessels, Bruce W.; Kanatzidis, Mercouri G.; Freeman, Arthur J.

    Heavy metal chalco-phosphate Pb2P2Se6 has shown a significant promise as an X-ray and γ-ray detector material. To assess the fundamental physical properties important for its performance as detector, theoretical calculations were performed for the electronic structure, band gaps, electron and hole effective masses, and static dielectric constants. The calculations were based on first-principles density functional theory (DFT) and employ the highly precise full potential linearized augmented plane wave method and the projector augmented wave method and include nonlocal exchange-correlation functionals to overcome the band gap underestimation in DFT calculations. The calculations show that Pb2P2Se6 is an indirect band gap material with the calculated band gap of 2.0 eV, has small effective masses, which could result in a good carrier mobility-lifetime product μτ , and a very high static dielectric constant, which could lead to high mobility of carriers by screening of charged scattering centers. We further investigated a large set of native defects in Pb2P2Se6 to determine the optimal growth conditions for application as γ-ray detectors. The results suggest that the prevalent intrinsic defects are selenium vacancies, followed by lead vacancies, then phosphorus vacancies and antisite defects. The effect of various chemical environments on defect properties was examined and the optimal conditions for material synthesis were suggested. Supported by DHS (Grant No. 2014-DN-077-ARI086-01).

  5. Estimation of a 2p2h effect on Gamow-Teller transitions within the second Tamm-Dancoff approximation

    NASA Astrophysics Data System (ADS)

    Minato, F.

    2016-04-01

    Two-particle two-hole (2p2h) effect on the Gamow-Teller (GT) transition for neutron-rich nuclei is studied by the second Tamm-Dancoff approximation (STDA) with the Skyrme interaction. Unstable 24O and 34Si and stable 48Ca nuclei are chosen to study the quenching and fragmentation of the GT strengths. Correlation of the 2p2h configurations causes about 20 % quenching and downward shift of GT giant resonances (GTGRs). The residual interaction changing relative angular momentum that appeared in the tensor force part gives a meaningful effect to the GT strength distributions. In this work, 17 - 26 % of the total GT strengths are brought to high-energy region above GTGRs. In particular, the tensor force brings strengths to high energy more than 50 MeV. STDA calculation within a small model space for 2p2h configuration is also performed and experimental data of 48Ca is reproduced reasonably.

  6. Metabolic and thermal stimuli control K2P2.1 (TREK-1) through modular sensory and gating domains

    PubMed Central

    Bagriantsev, Sviatoslav N; Clark, Kimberly A; Minor, Daniel L

    2012-01-01

    K2P2.1 (TREK-1) is a polymodal two-pore domain leak potassium channel that responds to external pH, GPCR-mediated phosphorylation signals, and temperature through the action of distinct sensors within the channel. How the various intracellular and extracellular sensory elements control channel function remains unresolved. Here, we show that the K2P2.1 (TREK-1) intracellular C-terminal tail (Ct), a major sensory element of the channel, perceives metabolic and thermal commands and relays them to the extracellular C-type gate through transmembrane helix M4 and pore helix 1. By decoupling Ct from the pore-forming core, we further demonstrate that Ct is the primary heat-sensing element of the channel, whereas, in contrast, the pore domain lacks robust temperature sensitivity. Together, our findings outline a mechanism for signal transduction within K2P2.1 (TREK-1) in which there is a clear crosstalk between the C-type gate and intracellular Ct domain. In addition, our findings support the general notion of the existence of modular temperature-sensing domains in temperature-sensitive ion channels. This marked distinction between gating and sensory elements suggests a general design principle that may underlie the function of a variety of temperature-sensitive channels. PMID:22728824

  7. 2P2IHUNTER: a tool for filtering orthosteric protein–protein interaction modulators via a dedicated support vector machine

    PubMed Central

    Hamon, Véronique; Bourgeas, Raphael; Ducrot, Pierre; Theret, Isabelle; Xuereb, Laura; Basse, Marie Jeanne; Brunel, Jean Michel; Combes, Sebastien; Morelli, Xavier; Roche, Philippe

    2014-01-01

    Over the last 10 years, protein–protein interactions (PPIs) have shown increasing potential as new therapeutic targets. As a consequence, PPIs are today the most screened target class in high-throughput screening (HTS). The development of broad chemical libraries dedicated to these particular targets is essential; however, the chemical space associated with this ‘high-hanging fruit’ is still under debate. Here, we analyse the properties of 40 non-redundant small molecules present in the 2P2I database (http://2p2idb.cnrs-mrs.fr/) to define a general profile of orthosteric inhibitors and propose an original protocol to filter general screening libraries using a support vector machine (SVM) with 11 standard Dragon molecular descriptors. The filtering protocol has been validated using external datasets from PubChem BioAssay and results from in-house screening campaigns. This external blind validation demonstrated the ability of the SVM model to reduce the size of the filtered chemical library by eliminating up to 96% of the compounds as well as enhancing the proportion of active compounds by up to a factor of 8. We believe that the resulting chemical space identified in this paper will provide the scientific community with a concrete support to search for PPI inhibitors during HTS campaigns. PMID:24196694

  8. Large negative thermal expansion in non-perovskite lead-free ferroelectric Sn2P2S6.

    PubMed

    Rong, Yangchun; Li, Menglei; Chen, Jun; Zhou, Mei; Lin, Kun; Hu, Lei; Yuan, Wenxia; Duan, Wenhui; Deng, Jinxia; Xing, Xianran

    2016-02-17

    Functional materials showing both negative thermal expansion (NTE) and physical performance, such as ferroelectricity and magnetism, have been extensively explored in the past decade. However, among ferroelectrics a remarkable NTE was only found in perovskite-type PbTiO3-based compounds. In this work, a large NTE of -4.7 × 10(-5) K(-1) is obtained in the non-perovskite lead-free ferroelectric Sn2P2S6 from 243 K to TC (338 K). Structure refinements and first-principle calculations reveal the effects of the Sn(ii) 5s-S 3p interaction on spontaneous polarization and its correlation with NTE. Then the mechanism of spontaneous volume ferroelectrostriction (SVFS) is verified and it could well elucidate the nature of NTE in ferroelectric Sn2P2S6. This is the first case to demonstrate the unusual NTE behavior by SVFS in a non-perovskite lead-free ferroelectric material.

  9. Application of Novel Molecular Field Theory to Helical Antiferromagnetic Ordering in EuCo2P2

    NASA Astrophysics Data System (ADS)

    Johnston, D. C.; Sangeetha, N. S.

    A formulation of Weiss molecular field theory (MFT) was recently advanced for antiferromagnetic (AFM) systems of identical crystallographically-equivalent local moments interacting by Heisenberg exchange that does not utilize the concept of magnetic sublattices.1 This formulation has the attractive feature that the magnetic and thermal properties in magnetic fields H --> 0 depend only on the interactions of a representative spin with its neighbors, and thus allows the properties of collinear and coplanar noncollinear AFM structures to be understood and modeled on the same footing. Neutron diffraction measurements showed that EuCo2P2 with the bct ThCr2Si2 -type structure undergoes an AFM transition to a coplanar noncollinear c-axis helical AFM structure below the ordering temperature TN = 66 . 5 K.2 Here we report the properties and apply our MFT to model the anisotropic magnetic susceptibility of single-crystal EuCo2P2 below TN. Research supported by U.S. Department of Energy, Division of Materials Science and Engineering, under Contract No. DE-AC02-07CH11358.

  10. NMR studies of the incommensurate helical antiferromagnet EuCo2P2 : Determination of antiferromagnetic propagation vector

    NASA Astrophysics Data System (ADS)

    Higa, Nonoka; Ding, Qing-Ping; Yogi, Mamoru; Sangeetha, N. S.; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika; Johnston, D. C.; Furukawa, Yuji

    2017-07-01

    Recently, Q.-P. Ding et al. [Phys. Rev. B 95, 184404 (2017), 10.1103/PhysRevB.95.184404] reported that their nuclear magnetic resonance (NMR) study on EuCo2As2 successfully characterized the antiferromagnetic (AFM) propagation vector of the incommensurate helix AFM state, showing that NMR is a unique tool for determination of the spin structures in incommensurate helical AFMs. Motivated by this work, we have carried out 153Eu, 31P, and 59Co NMR measurements on the helical antiferromagnet EuCo2P2 with an AFM ordering temperature TN=66.5 K. An incommensurate helical AFM structure was clearly confirmed by 153Eu and 31P NMR spectra on single-crystalline EuCo2P2 in zero magnetic field at 1.6 K and its external magnetic field dependence. Furthermore, based on 59Co NMR data in both the paramagnetic and incommensurate AFM states, we have determined the model-independent value of the AFM propagation vector k =(0 ,0 ,0.73 ±0.09 )2 π /c , where c is the c -axis lattice parameter. The temperature dependence of k is also discussed.

  11. NMR studies of the incommensurate helical antiferromagnet EuCo2P2: Determination of antiferromagnetic propagation vector

    DOE PAGES

    Higa, Nonoka; Ding, Qing -Ping; Yogi, Mamoru; ...

    2017-07-06

    Recently, Q.-P. Ding et al. reported that their nuclear magnetic resonance (NMR) study on EuCo2As2 successfully characterized the antiferromagnetic (AFM) propagation vector of the incommensurate helix AFM state, showing that NMR is a unique tool for determination of the spin structures in incommensurate helical AFMs. Motivated by this work, we have carried out 153Eu, 31P, and 59Co NMR measurements on the helical antiferromagnet EuCo2P2 with an AFM ordering temperature TN = 66.5 K. An incommensurate helical AFM structure was clearly confirmed by 153Eu and 31P NMR spectra on single-crystalline EuCo2P2 in zero magnetic field at 1.6 K and its externalmore » magnetic field dependence. Furthermore, based on 59Co NMR data in both the paramagnetic and incommensurate AFM states, we have determined the model-independent value of the AFM propagation vector k = (0,0,0.73±0.09)2π/c, where c is the c-axis lattice parameter. As a result, the temperature dependence of k is also discussed.« less

  12. The effect of Tb+3 on α-Sr2P2O7 phosphor for green LED phosphor application

    NASA Astrophysics Data System (ADS)

    Patel, Nimesh P.; Srinivas, M.; Verma, Vishwnath; Modi, Dhaval

    2015-06-01

    A series of Tb+3 activated α-Sr2P2O7 (Strontium Pyrophosphate) phosphors were synthesized by high temperature combustion synthesis method. The structural analysis has been done by x-ray diffraction and FTIR (Fourier Transform Infrared Spectrum). The results obtained in structural characterization indicate that the doping concentration did not affect the crystal phase and structure of the phosphors. X-ray diffraction pattern reveals that the all samples were consistence with the JCPDS card No. 24-1011. The phosphor was excited at 232 nm wavelength, very intense PL green emission peak have been observed at 545 nm. This illustrates, that the phosphors could be efficiently excited because of the charge transfer band of the host as well as the energy transfer process occurred between host (Sr2P2O7) and activator (Tb+3). By increasing the doping concentration of Tb+3, the intensity of 545 nm emission peak has been increased predominantly and it suggest that the phosphor prepared has very good application in green LED phosphor.

  13. Magnetization and transport properties of single RPd2P2 (R=Y, La-Nd, Sm-Ho, Yb)

    NASA Astrophysics Data System (ADS)

    Drachuck, Gil; Boehmer, Anna; Bud'Ko, Sergey L.; Canfield, Paul

    Single crystals of RPd2P2 (R=Y, La-Nd, Sm-Ho, Yb) were grown using a self-flux method and were characterized by room-temperature powder X-ray diffraction, anisotropic temperature and field dependent magnetization and temperature dependent in-plane resistivity. Anisotropic magnetic properties, arising mostly from crystal electric field (CEF) effects, were observed for most magnetic rare earths. The experimentally estimated CEF parameters B02 were calculated from the anisotropic paramagnetic θab and θcvalues. Ordering temperatures, as well as the polycrystalline averaged paramagnetic Curie-Weiss temperature, θave, were extracted from magnetization and resistivity measurements. Work done at Ames Laboratory was supported by US Department of Energy, Basic Energy Sciences, Division of Materials Sciences and Engineering under Contract No. DE-AC02-07CH111358.

  14. Radiative lifetimes of the 2s2p2(4P) metastable levels of N III

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.; Parkinson, W. H.

    1993-01-01

    The radiative decay rates of N III 175 nm intersystem lines were measured in the laboratory by recording the time dependence of photon intensities emitted as the 2s2p2(4P) metastable term of N(2+) ions decay to the 2s22p(2P0) ground term. A cylindrical radio frequency ion trap was used to store the electron impact-produced N(2+) ions. The radiative decay signals were analyzed by multiexponential least-squares fits to the data. The measured radiative decay rates to the ground term are 1019(+/- 64)/s for 4P sub 1/2, 74.5(+/- 5.4)/s for 4P sub 3/2, and 308( +/- 22)/s for 4P sub 5/2. Comparisons of the measured values with theoretical values are presented.

  15. Radiative lifetimes of the 2s2p2(4P) metastable levels of N III

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.; Parkinson, W. H.

    1993-01-01

    The radiative decay rates of N III 175 nm intersystem lines were measured in the laboratory by recording the time dependence of photon intensities emitted as the 2s2p2(4P) metastable term of N(2+) ions decay to the 2s22p(2P0) ground term. A cylindrical radio frequency ion trap was used to store the electron impact-produced N(2+) ions. The radiative decay signals were analyzed by multiexponential least-squares fits to the data. The measured radiative decay rates to the ground term are 1019(+/- 64)/s for 4P sub 1/2, 74.5(+/- 5.4)/s for 4P sub 3/2, and 308( +/- 22)/s for 4P sub 5/2. Comparisons of the measured values with theoretical values are presented.

  16. Structural Investigation of Phosphorus in CaO-SiO2-P2O5 Ternary Glass

    NASA Astrophysics Data System (ADS)

    Wang, Zhanjun; Cai, Shengjia; Zhang, Mei; Guo, Min; Zhang, Zuotai

    2017-04-01

    The system of CaO-SiO2-P2O5 ternary glass is not only among the major constituents of steelmaking slags in iron and steel industry, but also play a significant role in other industrial process, such as chemical engineering and glass industry. In the present study, the structure of CaO-SiO2-P2O5 ternary glass with varying P2O5 content from 0 to 15 wt pct at a fixed CaO/SiO2 = 1.4 was investigated using molecular dynamics (MD) simulation combined with X-ray photoelectron spectroscopy and Raman spectra techniques. The results indicated that P5+ ions have a higher affinity to Ca2+ ions which are then stripped away from the silicate network with the addition of P2O5, resulting in the formation of Ca-O-P and Si-O-Si linkages. In addition, almost all P5+ ions displayed as {{Q}}_{{P}}0 ( {{Q}}_{{P}}n , n is the number of bridging oxygen in one [PO4]-tetrahedra units) and a small fraction of P5+ ions behave as {{Q}}_{{P}}1 (P-O-P) and P-O-Si. The enhanced degree of polymerization can be detected from the increase of {{X}}_{{Si}}3 and X_{{P}}1 /X_{{P}}0 (mole fraction of {{Q}}_{{Si}}i or {{Q}}_{{P}}i ). Furthermore, the ratio of Raman scattering coefficients for Q_{{Si}}i /Q_{{Si}}1 and Q_{{P}}i /Q_{{P}}1 were determined by combining MD simulated result with Raman spectra, which were considered to be suitable to the present study.

  17. Structural Investigation of Phosphorus in CaO-SiO2-P2O5 Ternary Glass

    NASA Astrophysics Data System (ADS)

    Wang, Zhanjun; Cai, Shengjia; Zhang, Mei; Guo, Min; Zhang, Zuotai

    2017-02-01

    The system of CaO-SiO2-P2O5 ternary glass is not only among the major constituents of steelmaking slags in iron and steel industry, but also play a significant role in other industrial process, such as chemical engineering and glass industry. In the present study, the structure of CaO-SiO2-P2O5 ternary glass with varying P2O5 content from 0 to 15 wt pct at a fixed CaO/SiO2 = 1.4 was investigated using molecular dynamics (MD) simulation combined with X-ray photoelectron spectroscopy and Raman spectra techniques. The results indicated that P5+ ions have a higher affinity to Ca2+ ions which are then stripped away from the silicate network with the addition of P2O5, resulting in the formation of Ca-O-P and Si-O-Si linkages. In addition, almost all P5+ ions displayed as Q_{P}0 ( Q_{P}n , n is the number of bridging oxygen in one [PO4]-tetrahedra units) and a small fraction of P5+ ions behave as Q_{P}1 (P-O-P) and P-O-Si. The enhanced degree of polymerization can be detected from the increase of X_{Si}3 and X_{P}1 /X_{P}0 (mole fraction of {Q}_{Si}i or {Q}_{P}i ). Furthermore, the ratio of Raman scattering coefficients for Q_{Si}i /Q_{Si}1 and Q_{P}i /Q_{P}1 were determined by combining MD simulated result with Raman spectra, which were considered to be suitable to the present study.

  18. Optical inter-satellite communication with dynamically reconfigurable optical device using Sn2P2S6 crystal

    NASA Astrophysics Data System (ADS)

    Nishimaki, Kaori; Okamoto, Atsushi; Fujita, Tomohiro; Grabar, Alexander A.; Takabayashi, Masanori; Uozumi, Jun; Tomita, Akihisa; Takayama, Yoshihisa

    2011-03-01

    Since the optical inter-satellite communication has attractive advantages such as high-speed transmission with high confidence, almost no electronic magnetic interference, and low power consumption, it has been activity investigated. However, directivity control of the laser beams requires a bulky and complicated system in satellite mobile communications. A more flexible and high accurate system with small and simple mechanism has been desired. In this study, we propose a new method of optical inter-satellite communication with a dynamically reconfigurable optical directional device in which diffraction gratings are automatically rewritten and reorganized in response of incident conditions by moving satellites. For realizing such a device, we have developed Sn2P2S6 crystals which have a high sensitive photorefractivity and dynamic reconfigurable property. Furthermore, this crystal has hundreds times faster response than conventional photorefractive materials such as BaTiO3. These features are extremely advantageous to construct a high-speed and flexible communication system with a large tolerance to displacement of moving satellites. To investigate the possibility of the dynamically reconfigurable optical inter-satellite communication system, we experimentally evaluate the temporal and spatial characteristics of Sn2P2S6 crystals for the variation of the beam incident angle. Moreover, the diffraction beam from the crystal has phase conjugate wavefronts of the beam entering from the counter direction. We try to utilize this behavior to suppress the beam spread and to reduce the background light such as sunlight with a spatial filtering technique that has sensitivity in wavefront differences of the signal and background light.

  19. Tricritical Lifshitz point in the temperature-pressure-composition diagram for (PbySn1-y)2P2(SexS1-x)6 ferroelectrics

    NASA Astrophysics Data System (ADS)

    Andersson, O.; Chobal, O.; Rizak, I.; Rizak, V.

    2009-11-01

    The heat capacity of Sn2P2S6 ferroelectric crystals has been measured under quasihydrostatic pressures up to 0.7 GPa. The analysis of the heat-capacity and literature data for the birefringence shows that the tricritical point of Sn2P2S6 is in the 0.20-0.25 GPa range. Moreover, in the approximation of a linear change in the free-energy expansion coefficients, with respect to concentration and pressure, thermodynamic trajectories have been constructed for (PbySn1-y)2P2(SexS1-x)6 solid solutions. We have thereby identified the region of the T-p-y-x diagram for (PbySn1-y)2P2(SexS1-x)6 showing the tricritical Lifshitz point.

  20. Magnetization and transport properties of single crystalline RPd2P2 (R=Y, La–Nd, Sm–Ho, Yb)

    DOE PAGES

    Drachuck, Gil; Böhmer, Anna E.; Bud'ko, Sergey L.; ...

    2016-05-27

    Single crystals of RPd2P2 (R=Y, La–Nd, Sm–Ho, Yb) were grown out of a high temperature solution rich in Pd and P and characterized by room-temperature powder X-ray diffraction, anisotropic temperature- and field-dependent magnetization and temperature-dependent in-plane resistivity measurements. In this series, YPd2P2 and LaPd2P2 YbPd2P2 (with Yb2+) are non-local-moment bearing. Furthermore, YPd2P2 and LaPd2P2 are found to be superconducting with Tc≃0.75 and 0.96 K respectively. CePd2P2 and PrPd2P2 magnetically order at low temperature with a ferromagnetic component along the crystallographic c-axis. The rest of the series manifest low temperature antiferromagnetic ordering. EuPd2P2 has Eu2+ ions and both EuPd2P2 and GdPd2P2 have isotropic paramagnetic susceptibilities consistent with L =0 and J=S=more » $$\\frac{7}{2}$$ and exhibit multiple magnetic transitions. For R=Eu–Dy, there are multiple, T>1.8 K transitions in zero applied magnetic field and for R=Nd, Eu, Gd, Tb, and Dy there are clear metamagnetic transitions at T=2.0 K for H< 55 kOe. Strong anisotropies arising mostly from crystal electric field (CEF) effects were observed for most magnetic rare earths with L≠0. The experimentally estimated CEF parameters B$$_2^0$$ were calculated from the anisotropic paramagnetic θab and θc values and compared to theoretical trends across the rare earth series. Lastly, the ordering temperatures as well as the polycrystalline averaged paramagnetic Curie–Weiss temperature, θave, were extracted from magnetization and resistivity measurements, and compared to the de-Gennes factor.« less

  1. Residual Chemoresponsiveness to Acids in the Superior Laryngeal Nerve in “Taste-Blind” (P2X2/P2X3 Double-KO) Mice

    PubMed Central

    Ohkuri, Tadahiro; Horio, Nao; Stratford, Jennifer M.; Finger, Thomas E.; Ninomiya, Yuzo

    2012-01-01

    Mice lacking both the P2X2 and the P2X3 purinergic receptors (P2X-dblKO) exhibit loss of responses to all taste qualities in the taste nerves innervating the tongue. Similarly, these mice exhibit a near total loss of taste-related behaviors in brief access tests except for a near-normal avoidance of acidic stimuli. This persistent avoidance of acids despite the loss of gustatory neural responses to sour was postulated to be due to continued responsiveness of the superior laryngeal (SL) nerve. However, chemoresponses of the larynx are attributable both to taste buds and to free nerve endings. In order to test whether the SL nerve of P2X-dblKO mice remains responsive to acids but not to other tastants, we recorded responses from the SL nerve in wild-type (WT) and P2X-dblKO mice. WT mice showed substantial SL responses to monosodium glutamate, sucrose, urea, and denatonium—all of which were essentially absent in P2X-dblKO animals. In contrast, the SL nerve of P2X-dblKO mice exhibited near-normal responses to citric acid (50 mM) although responsiveness of both the chorda tympani and the glossopharyngeal nerves to this stimulus were absent or greatly reduced. These results are consistent with the hypothesis that the residual avoidance of acidic solutions by P2X-dblKO mice may be attributable to the direct chemosensitivity of nerve fibers innervating the laryngeal epithelium and not to taste. PMID:22362867

  2. Crystal and electronic structure changes during the charge-discharge process of Na4Co3(PO4)2P2O7

    NASA Astrophysics Data System (ADS)

    Moriwake, Hiroki; Kuwabara, Akihide; Fisher, Craig A. J.; Nose, Masafumi; Nakayama, Hideki; Nakanishi, Shinji; Iba, Hideki; Ikuhara, Yuichi

    2016-09-01

    Sodium-ion batteries offer a potential solution to the problem of limited lithium resources, and the newly developed positive electrode material Na4Co3(PO4)2P2O7 is attracting significant attention due to its high rate, high capacity, and high voltage compared to other sodium-ion battery materials. However, details of its electronic structure and its charge/discharge behavior are still uncertain. Here we report detailed first-principles calculations of the desodiation behavior of Na4Co3(PO4)2P2O7 using the GGA + U formalism of density functional theory. Assuming a stepwise desodiation process, removal of Na down to NaCo3(PO4)2P2O7 is found to be accompanied by oxidation of Co2+ to Co3+. Further removal of Na to give Co3(PO4)2P2O7 requires oxidation of oxygen 2p orbitals in the P2O7 polyhedra instead of Co3+ being oxidized to Co4+. The holes thus formed are expected to be strongly self-trapped, rendering them immobile at room temperature. At the same time, a large volume shrinkage is observed during this last desodiation step, constricting the Na migration channels. These two factors may explain the difficulty encountered experimentally in removing all Na from Na4Co3(PO4)2P2O7.

  3. /sup 90/Zr (p,n) and (n,p) distorted-wave impulse approximation cross sections in 2p2h random-phase approximation

    SciTech Connect

    Wambach, J.; Droz-dotdz-dot, S.; Schulte, A.; Speth, J.

    1988-03-01

    Within the distorted-wave impulse approximation and an extended random phase approximation theory which includes 1p 1h as well as 2p 2h excitations, we study (p,n) and (n,p) cross sections in /sup 90/Zr at 200 MeV. The inclusion of 2p2h excitations allows us to calculate spreading width effects microscopically without introduction of parameters. Given a fully microscopic description reasonable agreement between theory and experiment is found in the (p,n) channel. In the (n,p) channel at forward angles we find that the compact spin-dipole resonance predicted by 1p1h random-phase approximation calculations is not strongly effected by 2p2h mixing

  4. High-pressure synchrotron Mössbauer and X-ray diffraction studies: Exploring the structure-related valence fluctuation in EuNi2P2

    NASA Astrophysics Data System (ADS)

    Li, Chunyu; Yu, Zhenhai; Bi, Wenli; Zhao, Jiyong; Hu, Michael Y.; Zhao, Jinggeng; Wu, Wei; Luo, Jianlin; Yan, Hao; Alp, Esen E.; Liu, Haozhe

    2016-11-01

    The high-pressure effect on valence fluctuation of the ThCr2Si2-type intermetallic compound EuNi2P2 has been investigated using in situ synchrotron Mössbauer spectroscopy (SMS). The isomer shift of 151Eu in EuNi2P2 increases monotonically with increasing pressure up to 50 GPa, suggesting a valence transition of the Eu from mixed toward trivalent. The synchrotron angle-dispersive X-ray diffraction (AD-XRD) experiment shows that EuNi2P2 remains in the tetragonal structure up to 32.5 GPa at room temperature. We propose that the evolutions of bonding distance with pressure have an obvious effect on the valence fluctuation.

  5. Bulk Electronic Structure of Superconducting LaRu2P2 Single Crystals Measured by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Razzoli, E.; Kobayashi, M.; Strocov, V. N.; Delley, B.; Bukowski, Z.; Karpinski, J.; Plumb, N. C.; Radovic, M.; Chang, J.; Schmitt, T.; Patthey, L.; Mesot, J.; Shi, M.

    2012-06-01

    We present a soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES) study of the stoichiometric pnictide superconductor LaRu2P2. The observed electronic structure is in good agreement with density functional theory (DFT) calculations. However, it is significantly different from its counterpart in high-temperature superconducting Fe pnictides. In particular, the bandwidth renormalization present in the Fe pnictides (˜2-3) is negligible in LaRu2P2 even though the mass enhancement is similar in both systems. Our results suggest that the superconductivity in LaRu2P2 has a different origin with respect to the iron pnictides. Finally, we demonstrate that the increased probing depth of SX-ARPES, compared to the widely used ultraviolet ARPES, is essential in determining the bulk electronic structure in the experiment.

  6. NMR investigation of spin fluctuations in the itinerant-electron magnetic compound Sr1 -xCaxCo2P2

    NASA Astrophysics Data System (ADS)

    Imai, Masaki; Michioka, Chishiro; Ueda, Hiroaki; Yoshimura, Kazuyoshi

    2017-02-01

    We took P31 NMR measurements of mainly paramagnetic phase Sr1 -xCaxCo2P2 (0 ≤x ≤0.5 ) to reveal the itinerant-electron metamagnetic transition, and of its magnetically ordered phase (0.7 ≤x ≤1 ), and characterized their spin fluctuations by estimating the spin fluctuation parameter T0 corresponding to the width of the spin fluctuation in the spectrum in frequency space. SrCo2P2 has a quasi-two-dimensional uncollapsed tetragonal (ucT) cell without interlayer P-P bonds, whereas CaCo2P2 has a three-dimensional collapsed tetragonal (cT) cell with P-P bonds. The a b -in-plane component of T0 is much larger than the out-of-plane component in SrCo2P2 . As x increases from 0 to 0.5, the in-plane component of T0 decreases proportionally with the metamagnetic transition field. In the antiferromagnetic cT phase (0.7 ≤x ≤1 ), T0 is constant and spin fluctuations show an isotropic character in contrast to their behavior in the paramagnetic ucT phase (0 ≤x ≤0.5 ). These results indicate that the in-plane spin fluctuations due to the quasi-two-dimensional crystal structure play a significant role in the metamagnetic transition of this system.

  7. The splitting and oscillator strengths for the 2S/2/S-2p/2/P/0/ doublet in lithium-like sulfur. [during Skylab observed solar flares

    NASA Technical Reports Server (NTRS)

    Pegg, D. J.; Forester, J. P.; Elston, S. B.; Griffin, P. M.; Peterson, R. S.; Thoe, R. S.; Vane, C. R.; Sellin, I. A.; Groeneveld, K.-O.

    1977-01-01

    The beam-foil technique has been used to study the 2S(2)S-2p(2)P(0) doublet in S XIV. The results confirm the doublet splitting measured aboard Skylab during solar flare events. In addition, the oscillator strengths for the resonance transitions comprising this doublet have been measured and found to agree well with recent relativistic f-value calculations.

  8. The stimulation of proliferation and differentiation of periodontal ligament cells by the ionic products from Ca7Si2P2O16 bioceramics.

    PubMed

    Zhou, Yinghong; Wu, Chengtie; Xiao, Yin

    2012-07-01

    The ultimate goal of periodontal tissue engineering is to produce predictable regeneration of alveolar bone, root cementum, and periodontal ligament, which are lost as a result of periodontal diseases. To achieve this goal, it is of great importance to develop novel bioactive materials which could stimulate the proliferation, differentiation and osteogenic/cementogenic gene expression of periodontal ligament cells (PDLCs) for periodontal regeneration. In this study, we synthesized novel Ca(7)Si(2)P(2)O(16) ceramic powders for the first time by the sol-gel method and investigated the biological performance of PDLCs after exposure to different concentrations of Ca(7)Si(2)P(2)O(16) extracts. The original extracts were prepared at 200 mg ml(-1) and further diluted with serum-free cell culture medium to obtain a series of diluted extracts (100, 50, 25, 12.5 and 6.25 mg ml(-1)). Proliferation, alkaline phosphatase (ALP) activity, Ca deposition, and osteogenesis/cementogenesis-related gene expression (ALP, Col I, Runx2 and CEMP1) were assayed for PDLCs on days 7 and 14. The results showed that the ionic products from Ca(7)Si(2)P(2)O(16) powders significantly stimulated the proliferation, ALP activity, Ca deposition and osteogenesis/cementogenesis-related gene expression of PDLCs. In addition, it was found that Ca(7)Si(2)P(2)O(16) powders had excellent apatite-mineralization ability in simulated body fluids. This study demonstrated that Ca(7)Si(2)P(2)O(16) powders with such a specific composition possess the ability to stimulate the PDLC proliferation and osteoblast/cemenoblast-like cell differentiation, indicating that they are a promising bioactive material for periodontal tissue regeneration application.

  9. Fusion protein His-Hsp65-6IA2P2 prevents type 1 diabetes through nasal immunization in NOD Mice.

    PubMed

    Lu, Shiping; Li, Guoliang; Liu, Kunfeng; Yang, Xue; Cao, Rongyue; Zong, Li; Long, Jun; Jin, Liang; Wu, Jie

    2016-06-01

    Human heat shock protein 60 (Hsp60), is an endogenous β-cells autoantigen, it could postpone the onset of insulitis and sooner type 1 diabetes mellitus. P277 is one of Hsp65 determinants at position 437-469 of amino acids cascaded. Meanwhile, it's already well-known that there were several better anti-diabetic B epitopes, such as insulinoma antigen-2 (IA-2). Currently, fusion protein IA2P2 has constructed in order to enhance its pharmacological efficacy. In addition, added homologous bacterial-derived Hsp65 and His tag were beneficial to protein immunogenicity and purification separately. So, finally we examined a fusion protein His-Hsp65-6IA2P2 could regulate Th2 immune response and reduce natural diabetic incidence in NOD mice. We constructed two express vector pET28a-His-Hsp65-6P277 and pET28a-His-Hsp65-6IA2P2. After purification, we observed that triple intranasal administration of these two fusion protein in 4-week-old NOD mice maintained normal blood glucose and weight, with a lower diabetic or insulitis incidence. Consistent with induced splenic T cells proliferation and tolerance, His-Hsp65-6IA2P2-treated mice performed reduced IFN-γ and increased IL-10 level. In conclusion, we suggested that fusion protein His-Hsp65-6IA2P2 could be reconstructed and purified successively. Furthermore, nasal administration of this fusion protein could rebalance T cells population and prevent T1DM.

  10. K2M(H2P2O7)2.2H2O (M = Ni, Cu, Zn): orthorhombic forms and Raman spectra.

    PubMed

    Essehli, Rachid; El Bali, Brahim; Alaoui Tahiri, Aziz; Lachkar, Mohammed; Manoun, Bouchaib; Dusek, Michal; Fejfarova, Karla

    2005-12-01

    The crystal structures of three isotypic orthorhombic dihydrogendiphosphates, namely dipotassium copper(II)/nickel(II)/zinc(II) bis(dihydrogendiphosphate) dihydrate, K2M(H2P2O7)2.2H2O (M = Cu, Ni and Zn), have been refined from single-crystal data. The M2+ and K+ cations are located at sites of m symmetry, and the P atoms occupy general positions. These compounds also exist in triclinic forms with very similar structural features. The structures of both forms are compared, as well as the geometry of the MO6 octahedron, which is considerably elongated towards the water molecules for M = Ni and Cu. Such elongation has not been observed among the other representatives of the family. A Raman study of the whole series K2M(H2P2O7)2.2H2O (M = Mn, Co, Ni, Cu, Zn and Mg) is reported.

  11. Penta­cobalt(II) divanadium(III) tetrakis(diphosphate), Co5V2(P2O7)4

    PubMed Central

    Bronova, Anna; Glaum, Robert; Litterscheid, Christian

    2013-01-01

    Co5V2(P2O7)4 was crystallized by chemical vapour transport using HCl as transport agent. Its crystal structure is isotypic to that of FeII 5FeIII 2(P2O7)4 and can be regarded as a member of the thortveitite structure family with corrugated layers of metal–oxygen polyhedra extending parallel to (010). Significant occupational disorder between cobalt(II) and vanadium(III) is observed. Four of the five cation sites are occupied by both cobalt and vanadium. The fifth cation site (Co1) is occupied by cobalt only. Sites Co1, M3 and M4 are located on twofold axes. Sites Co1, M2, M3 and M4 show o­cta­hedral coordination by oxygen; M5 has a square-pyramidal environment. PMID:23723750

  12. Experimental visualization of the diffusion pathway of sodium ions in the Na3[Ti2P2O10F] anode for sodium-ion battery.

    PubMed

    Ma, Zhaohui; Wang, Yuesheng; Sun, Chunwen; Alonso, J A; Fernández-Díaz, M T; Chen, Liquan

    2014-11-27

    Sodium-ion batteries have attracted considerable interest as an alternative to lithium-ion batteries for electric storage applications because of the low cost and natural abundance of sodium resources. The materials with an open framework are highly desired for Na-ion insertion/extraction. Here we report on the first visualization of the sodium-ion diffusion path in Na3[Ti2P2O10F] through high-temperature neutron powder diffraction experiments. The evolution of the Na-ion displacements of Na3[Ti2P2O10F] was investigated with high-temperature neutron diffraction (HTND) from room temperature to 600°C; difference Fourier maps were utilized to estimate the Na nuclear-density distribution. Temperature-driven Na displacements indicates that sodium-ion diffusion paths are established within the ab plane. As an anode for sodium-ion batteries, Na3[Ti2P2O10F] exhibits a reversible capacity of ~100 mAh g(-1) with lower intercalation voltage. It also shows good cycling stability and rate capability, making it promising applications in sodium-ion batteries.

  13. Blue-green luminescence in Hg free excited Sr2P2O7:Tb3+ pyrophosphate phosphor for NUV excited LEDs

    NASA Astrophysics Data System (ADS)

    Kohale, R. L.; Chimankar, O. P.; Dhoble, S. J.

    2015-02-01

    Tb3+ activated Sr2P2O7 phosphor was prepared by modified solid state diffusion technique at 700°C. The XRD pattern of Sr2P2O7 is in well argument with the standard ICDD File (24-1011) available. Surface morphology of the present phosphor has been studied by scanning electron microscope (SEM). In photoluminescence investigation, the excitation spectra of the phosphor extends from 200 to 400 nm gives optimum absorption at 352 nm, which is mercury free excitation and characteristics of NUV excited LED. Under the excitation of 352 nm, Sr2P2O7 doped with trivalent terbium ions produces weak blue emission between 400-500 nm owing to the 5D3 to the 7FJ transitions of Tb3+ and strong green emission in 500650 nm region of the visible spectrum due to the 4f-4f transitions from the 5D4 to 7FJ (J=6, 5, 4, 3) states of Tb3+. The entire study reveals that the present phosphor have promising applications in the lamp industry especially for solid state lighting (mercury free excited lamp phosphor) and NUV LEDs.

  14. Experimental visualization of the diffusion pathway of sodium ions in the Na3[Ti2P2O10F] anode for sodium-ion battery

    PubMed Central

    Ma, Zhaohui; Wang, Yuesheng; Sun, Chunwen; Alonso, J. A.; Fernández-Díaz, M. T.; Chen, Liquan

    2014-01-01

    Sodium-ion batteries have attracted considerable interest as an alternative to lithium-ion batteries for electric storage applications because of the low cost and natural abundance of sodium resources. The materials with an open framework are highly desired for Na-ion insertion/extraction. Here we report on the first visualization of the sodium-ion diffusion path in Na3[Ti2P2O10F] through high-temperature neutron powder diffraction experiments. The evolution of the Na-ion displacements of Na3[Ti2P2O10F] was investigated with high-temperature neutron diffraction (HTND) from room temperature to 600°C; difference Fourier maps were utilized to estimate the Na nuclear-density distribution. Temperature-driven Na displacements indicates that sodium-ion diffusion paths are established within the ab plane. As an anode for sodium-ion batteries, Na3[Ti2P2O10F] exhibits a reversible capacity of ~100 mAh g−1 with lower intercalation voltage. It also shows good cycling stability and rate capability, making it promising applications in sodium-ion batteries. PMID:25427677

  15. Luminescence study and dosimetry approach of Ce on an α-Sr2 P2 O7 phosphor synthesized by a high-temperature combustion method.

    PubMed

    Patel, Nimesh P; Srinivas, M; Modi, Dhaval; Vishwnath, Verma; Murthy, K V R

    2015-06-01

    We report synthesis of a cerium-activated strontium pyrophosphate (Sr2 P2 O7 ) phosphor using a high-temperature combustion method. Samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) and thermoluminescence (TL). The XRD pattern reveals that Sr2 P2 O7 has an α-phase with crystallization in the orthorhombic space group of Pnam. The IR spectrum of α-Sr2 P2 O7 displays characteristic bands at 746 and 1190 cm(-1) corresponding to the absorption of (P2 O7 )(-4) . PL emission spectra exhibit a broad emission band around 376 nm in the near-UV region due to the allowed 5d-4f transition of cerium and suggest its applications in a UV light-emitting diode (LED) source. PL also reveals that the emission originates from 5d-4f transition of Ce(3+) and intensity increases with doping concentration. TL measurements made after X-ray irradiation, manifest a single intense glow peak at around 192°C, which suggests that this is an outstanding candidate for dosimetry applications. The kinetic parameters, activation energy and frequency factor of the glow curve were calculated using different analysis methods. Copyright © 2014 John Wiley & Sons, Ltd.

  16. A novel pyrophosphate BaCr2(P2O7)2 as green pigment with high NIR solar reflectance and durable chemical stability

    NASA Astrophysics Data System (ADS)

    Tao, Zhengxu; Zhang, Wanqi; Huang, Yanlin; Wei, Donglei; Seo, Hyo Jin

    2014-08-01

    A novel pyrophosphate BaCr2(P2O7)2 was synthesized by the conventional solid-state reaction. The X-ray diffraction (XRD), FTIR spectrum, scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) near infrared (NIR) reflectance spectra were applied to characterize the powders. The refractive indexes and nature of the VB and CB were determined. The structure, color properties and application were investigated. The results reveal that the anomalist bodies with smooth surfaces were obtained at 1200 °C with a mean size of 3 μm. A high reflectance peak at 535 nm was observed in the visible region, which is associated with the brilliant and deep green color of this pigment. With all the acids, alkali and deionized water treatment, the polycrystalline pigment BaCr2(P2O7)2 was found to be durable in chemical stability. The significantly high NIR solar reflectance of BaCr2(P2O7)2 is 90.0%, a higher cooling ability, so it has been selected to be tested as cool green pigment in ceramics. Moreover, this novel pyrophosphate pigment has great potential as cool pigment for surface coating applications.

  17. 2p2 Team News

    NASA Astrophysics Data System (ADS)

    Jones, H.

    2001-03-01

    In December we welcomed Emanuel Galliano to our team. Emanuel is a French student at ESO Chile who is already familiar with La Silla, through his previous work with the DENIS group. He will be working primarily on operations at the 2.2-m. In February, however, we bade farewell to Emanuela Pompei after nearly two years with the team. Although Emanuela is leaving La Silla, she will remain with ESO in Chile, commencing work as a Staff Astronomer on Paranal in March. We wish her all the best in her move north.

  18. The Diphosphorus Complex [Cp2Mo2(CO)4(η(2)-P2)] as a Building Block for the Synthesis of Mixed-Hybrid Coordination Polymers.

    PubMed

    Moussa, Mehdi Elsayed; Attenberger, Bianca; Fleischmann, Martin; Schreiner, Andrea; Scheer, Manfred

    2016-10-01

    The three-component reaction of the tetrahedral diphosphorus complex [Cp2Mo2(CO)4(η(2)-P2)] (1), with Ag[BF4] (2) in the presence of 2,2'-bipyrimidine (3) leads to the formation of the two novel two-dimensional networks 4 and 5. Compound 4 is a new two-dimensional organometallic-organic hybrid polymer, while derivative 5 represents a unique two-dimensional organometallic-inorganic-organic hybrid polymer. These results show the possibility of synthesizing a new class of coordination polymers, which could not be obtained from two-component reactions with organic molecules in addition of metal ions.

  19. Magnetic phase transition of high-pressure phase (VO)2P2O7 studied by high-field ESR measurements

    NASA Astrophysics Data System (ADS)

    Hiraka, K.; Nagasaka, Y.; Kunimoto, T.; Inagaki, Y.; Okubo, S.; Ohta, H.; Saito, T.; Azuma, M.; Takano, M.

    2004-05-01

    The high-pressure phase of (VO)2P2O7 (HP-VOPO) is a S=1/2 Heisenberg antiferromagnetic alternating chain compound with one spin gap. The high-field ESR measurements of the HP-VOPO single crystal have been performed using the pulsed magnetic field up to 30T. Small anomaly is observed in ESR mode for both a- and b-axis. The linewidth became broad around Bc=20T when the field is applied along the a- and b-axis. The magnetic state of HP-VOPO above Bc will be discussed.

  20. Temporal Dynamics of Two Beam Coupling and the Origin of Compensation Photorefractive Gratings in Sn2P2S6:Sb (Postprint)

    DTIC Science & Technology

    2017-03-29

    Hypothiodiphosphate (Sn2P2S6, SPS) possesses impressive optical nonlinearities, especially a pronounced photorefractive effect in the red and near...saturates well before the slow grating develops in full (τf τs). The dashed gray lines and solid red line in Fig. 4 show the results of the best fits of...and τs , respectively. Half-filled ( red ) symbols are used for the antimony doped sample K33, while open symbols denote the nominally undoped

  1. Induction of MDM2-P2 Transcripts Correlates with Stabilized Wild-Type p53 in Betel- and Tobacco-Related Human Oral Cancer

    PubMed Central

    Ralhan, Ranju; Sandhya, Agarwal; Meera, Mathur; Bohdan, Wasylyk; Nootan, Shukla K.

    2000-01-01

    MDM2, a critical element of cellular homeostasis mechanisms, is involved in complex interactions with important cell-cycle and stress-response regulators including p53. The mdm2-P2 promoter is a transcriptional target of p53. The aim of this study was to determine the association between mdm2-P2 transcripts and the status of the p53 gene in betel- and tobacco-related oral squamous cell carcinomas (SCCs) to understand the mechanism of deregulation of MDM2 and p53 expression and their prognostic implications in oral tumorigenesis. Elevated levels of MDM2 proteins were observed in 11 of 25 (44%) oral hyperplastic lesions, nine of 15 (60%) dysplastic lesions, and 71 of 100 (71%) SCCs. The intriguing feature of the study was the identification and different subcellular localization of three isoforms of MDM2 (ie, 90 kd, 76 kd, and 57 kd) in oral SCCs and their correlation with p53 overexpression in each tumor. The hallmark of the study was the detection of mdm2-P2 transcripts in 12 of 20 oral SCCs overexpressing both MDM2 and p53 proteins while harboring wild-type p53 alleles. Furthermore, mdm2 amplification was an infrequent event in betel- and tobacco-associated oral tumorigenesis. The differential compartmentalization of the three isoforms of MDM2 suggests that each has a distinct function, potentially in the regulation of p53 and other gene products implicated in oral tumorigenesis. In conclusion, we report herein the first evidence suggesting that enhanced translation of mdm2-P2 transcripts (S-mdm2) may represent an important mechanism of overexpression and consequent stabilization and functional inactivation of wild-type p53 serving as an adverse prognosticator in betel- and tobacco-related oral cancer. The clinical significance of the functional inactivation of wild-type p53 by MDM2 is underscored by the significantly shorter median disease-free survival time (16 months) observed in p53/MDM2-positive cases as compared to those which did not show co-expression of

  2. Crystal structure of Rb2Mn3(H2O)2[P2O7]2, a new representative of the family of hydrated diphosphates

    NASA Astrophysics Data System (ADS)

    Kiriukhina, G. V.; Yakubovich, O. V.; Dimitrova, O. V.; Volkov, A. S.

    2016-09-01

    The crystal structure of Rb2Mn3(H2O)2[P2O7]2, a new phase obtained in the form of single crystals under hydrothermal conditions in the MnCl2-Rb3PO4-H2O system, is determined by X-ray diffraction (Xcalibur-S-CCD diffractometer, R = 0.0270): a = 9.374(2), b = 8.367(2), c = 9.437(2) Å, ß = 99.12(2)°, space group P21/ c, Z = 2, D x = 3.27 g/cm3. A correlation between the unit-cell parameters and the size of cations forming the crystal structures of isostructural A2M3(H2O)2[P2O7]2 diphosphates ( A = K, NH4, Rb, or Na; M = Mn, Fe, Co, or Ni) is revealed. It is shown that, due to the topological similarity, the structures of diphosphates and orthophosphates of the farringtonite structural type can undergo mutual transformations.

  3. Heavy-metal extraction from sewage sludge using phosphorous-based salts: optimization process with Na2H2P2O7.

    PubMed

    Navarro-González, Milagros; Ortega-López, Vanesa; Lópéz-Fernández, Juana I; Amo-Salas, Mariano; González-Carcedo, Salvador

    2016-11-24

    Land application is one of the important disposal alternatives for sewage sludge, but availability of potential toxic metals often restricts its uses. Three phosphorous-based salts (Na2H2P2O7, K4P2O7, KH2PO4) were studied as potential metal extractants. The conclusions of the research were that greater extractive efficiency is achieved through a 30-min process of vertical shaking with disodium diacid pyrophosphate - Na2H2P2O7 - at a concentration of 0.2 M at pH 2. Alternatively, the optimized process with oscillating shaking equipment would require 60 min. In both cases the average of set of extracted metals is around 50%. A second extraction process with potassium pyrophosphate - K4P2O7 at pH 6 achieved the reduction of further total amounts of metal, upper 65% with respect to the initial content. In this way the sludge could be used in land applications, with restrictions on each soil, according to the limit values specified in the future regulations.

  4. Structure of the calcium pyrophosphate monohydrate phase (Ca2P2O7·H2O): towards understanding the dehydration process in calcium pyrophosphate hydrates.

    PubMed

    Gras, Pierre; Ratel-Ramond, Nicolas; Teychéné, Sébastien; Rey, Christian; Elkaim, Erik; Biscans, Béatrice; Sarda, Stéphanie; Combes, Christèle

    2014-09-01

    Calcium pyrophosphate hydrate (CPP, Ca(2)P(2)O(7) · nH2O) and calcium orthophosphate compounds (including apatite, octacalcium phosphate etc.) are among the most prevalent pathological calcifications in joints. Even though only two dihydrated forms of CPP (CPPD) have been detected in vivo (monoclinic and triclinic CPPD), investigations of other hydrated forms such as tetrahydrated or amorphous CPP are relevant to a further understanding of the physicochemistry of those phases of biological interest. The synthesis of single crystals of calcium pyrophosphate monohydrate (CPPM; Ca(2)P(2)O(7) · H2O) by diffusion in silica gel at ambient temperature and the structural analysis of this phase are reported in this paper. Complementarily, data from synchrotron X-ray diffraction on a CPPM powder sample have been fitted to the crystal parameters. Finally, the relationship between the resolved structure for the CPPM phase and the structure of the tetrahydrated calcium pyrophosphate β phase (CPPT-β) is discussed.

  5. 2P2I HUNTER: a tool for filtering orthosteric protein-protein interaction modulators via a dedicated support vector machine.

    PubMed

    Hamon, Véronique; Bourgeas, Raphael; Ducrot, Pierre; Theret, Isabelle; Xuereb, Laura; Basse, Marie Jeanne; Brunel, Jean Michel; Combes, Sebastien; Morelli, Xavier; Roche, Philippe

    2014-01-06

    Over the last 10 years, protein-protein interactions (PPIs) have shown increasing potential as new therapeutic targets. As a consequence, PPIs are today the most screened target class in high-throughput screening (HTS). The development of broad chemical libraries dedicated to these particular targets is essential; however, the chemical space associated with this 'high-hanging fruit' is still under debate. Here, we analyse the properties of 40 non-redundant small molecules present in the 2P2I database (http://2p2idb.cnrs-mrs.fr/) to define a general profile of orthosteric inhibitors and propose an original protocol to filter general screening libraries using a support vector machine (SVM) with 11 standard Dragon molecular descriptors. The filtering protocol has been validated using external datasets from PubChem BioAssay and results from in-house screening campaigns. This external blind validation demonstrated the ability of the SVM model to reduce the size of the filtered chemical library by eliminating up to 96% of the compounds as well as enhancing the proportion of active compounds by up to a factor of 8. We believe that the resulting chemical space identified in this paper will provide the scientific community with a concrete support to search for PPI inhibitors during HTS campaigns.

  6. Quantum oscillations of the superconductor LaRu2P2: Comparable mass enhancement λ≈1 in Ru and Fe phosphides

    NASA Astrophysics Data System (ADS)

    Moll, Philip J. W.; Kanter, Jakob; McDonald, Ross D.; Balakirev, Fedor; Blaha, Peter; Schwarz, Karlheinz; Bukowski, Zbigniew; Zhigadlo, Nikolai D.; Katrych, Sergiy; Mattenberger, Kurt; Karpinski, Janusz; Batlogg, Bertram

    2011-12-01

    We have studied the angular-dependent de Haas-van Alphen oscillations of LaRu2P2 using magnetic torque in pulsed magnetic fields up to 60 T. The observed oscillation frequencies are in excellent agreement with the geometry of the calculated Fermi surface. The temperature dependence of the oscillation amplitudes reveals effective masses m*(α)=0.71 and m*(β)=0.99 me, which are enhanced over the calculated band mass by λcyc of 0.8. We find a similar enhancement of λγ≈1 in comparing the measured electronic specific heat (γ=11.5 mJ/mol K2) with the total density of states from band-structure calculations. Remarkably, very similar mass enhancements have been reported in other pnictides, LaFe2P2, LaFePO (Tc≈4K), and LaRuPO, independent of whether they are superconducting or not. This is contrary to the common perceptions that the normal-state quasiparticle renormalizations reflect the strength of the superconducting pairing mechanism and leads to new questions about pairing in isostructural and isoelectronic Ru- and Fe-pnictide superconductors.

  7. Fully gapped superconductivity in Ni-pnictide superconductors BaNi2As2 and SrNi2P2

    NASA Astrophysics Data System (ADS)

    Kurita, N.; Ronning, F.; Miclea, C. F.; Tokiwa, Y.; Bauer, E. D.; Subedi, A.; Singh, D. J.; Sakai, H.; Thompson, J. D.; Movshovich, R.

    2011-01-01

    We have performed low-temperature specific heat C and thermal conductivity κ measurements on the Ni-pnictide superconductors BaNi2As2 (Tc = 0.7K) and SrNi2P2 (Tc = 1.4K). The temperature dependences C(T) and κ(T) of the two compounds are similar to the results of a number of s-wave superconductors. Furthermore, the concave field responses of the residual κ for BaNi2As2 rules out the presence of nodes on the Fermi surfaces. We postulate that fully gapped superconductivity could be universal for Ni-pnictide superconductors. Specific heat data on Ba0.6La0.4Ni2As2 shows a mild suppression of Tc and Hc2 relative to BaNi2As2.

  8. Absolute cross sections for near-threshold electron-impact excitation of the 2s 2S-->2p 2P transition in C3+

    NASA Astrophysics Data System (ADS)

    Bannister, M. E.; Chung, Y.-S.; Djurić, N.; Wallbank, B.; Woitke, O.; Zhou, S.; Dunn, G. H.; Smith, A. C.

    1998-01-01

    Absolute total cross sections for electron-impact excitation of the 2s 2S-->2p 2P transition in C3+ were measured from 7.35 eV to 8.45 eV using the merged electron-ion-beams energy-loss technique. The results settle the discrepancy between two previous experiments using the crossed-beams fluorescence method, being in very good agreement with the older results [P. O. Taylor, D. Gregory, G. H. Dunn, R. A. Phaneuf, and D. H. Crandall, Phys. Rev. Lett. 39, 1256 (1977)] but less so with the more recent ones [D. W. Savin, L. D. Gardner, D. B. Reisenfeld, A. R. Young, and J. L. Kohl, Phys. Rev. A 51, 2162 (1995)]. The present measurements are also in good agreement with unitarized Coulomb-Born and close-coupling calculations.

  9. Measurements of radiative-decay rates of the 2s22p(2P°)-2s2p2(4P) intersystem transitions of C+

    NASA Astrophysics Data System (ADS)

    Fang, Z.; Kwong, Victor H. S.; Wang, Jiebing; Parkinson, W. H.

    1993-08-01

    The radiative-decay rates of the 2s22p(2P0)-2s2p2(4P) intersystem transitions of C+ ions have been measured by recording the time dependence of the ~233-nm emission. A cylindrical radio-frequency ion trap was used to store electron-impact-produced C+ ions. The time-dependent signals were analyzed by multiexponential least-squares fits to the data. The measured radiative-decay rates to the ground term are 146.4(+8.3,-9.2) s-1 for 4P1/2, 11.6(+0.8,-1.7) s-1 for 4P3/2, and 51.2(+2.6,-3.5) s-1 for 4P5/2. Comparison of the measured values with theoretical values is presented.

  10. Dichloro-Cycloazatriphosphane: The Missing Link between N2 P2 and P4 Ring Systems in the Systematic Development of NP Chemistry.

    PubMed

    Bresien, Jonas; Hinz, Alexander; Schulz, Axel; Suhrbier, Tim; Thomas, Max; Villinger, Alexander

    2017-09-12

    A dichloro-cycloazatriphosphane that incorporates a cyclic NP3 backbone could be synthesized using knowledge gained from the chemistry of N2 P2 and P4 ring systems. It fills the gap between the congeneric compounds [ClP(μ-NR)]2 and [ClP(μ-PR)]2 (R=sterically demanding substituent), and thus contributes to the systematic development of nitrogen-phosphorus chemistry in general. The title compound was studied with respect to its formation via a labile aminodiphosphene, which readily underwent different rearrangement reactions depending on the solvent. All compounds were fully characterized by experimental and computational methods. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Modification of magnetic anisotropy through 3d-4f coupling in La0.75Pr0.25Co2P2

    NASA Astrophysics Data System (ADS)

    Kovnir, Kirill; Thompson, Corey M.; Garlea, V. Ovidiu; Haskel, Daniel; Polyanskii, Anatolii A.; Zhou, Haidong; Shatruk, Michael

    2013-09-01

    Magnetic behavior of La0.75Pr0.25Co2P2 was investigated by a combination of magnetic measurements, magneto-optical imaging, neutron diffraction, and x-ray absorption spectroscopy, including x-ray magnetic circular dichroism. The material crystallizes in the ThCr2Si2 structure type and exhibits three consecutive magnetic phase transitions. At 167 K, the Co magnetic moments order ferromagnetically in the ab plane of the tetragonal crystal structure. At 66 K, a ferromagnetic ordering of Pr(4f) moments parallel to the c axis causes a rotation of the Co(3d) moments towards the c axis in the direction opposite to the Pr moments, thus forming a noncollinear ferrimagnetically ordered structure and switching the direction of the total magnetization from the ab plane to the c axis. The third magnetic transition observed at 35 K is likely associated with the establishment of the collinear ferrimagnetic order along the c axis.

  12. Hyperbolic decay of photo-created Sb2+ ions in Sn2P2S6:Sb crystals detected with electron paramagnetic resonance

    NASA Astrophysics Data System (ADS)

    Basun, S. A.; Halliburton, L. E.; Evans, D. R.

    2017-01-01

    In this paper, we employed a method that overcomes the known limitations of electron paramagnetic resonance (EPR) to monitor charge trap dynamics over a broad temperature range not normally accessible due to the lifetime broadening of the EPR lines at higher temperatures. This was achieved by measuring the decay of the EPR intensity after thermal annealing by rapid cycling back to low temperatures for the EPR measurement. This technique was used to experimentally demonstrate interesting physics in the form of a direct measurement of the hyperbolic decay 1/(1+t) of a charge trap population, which previously was only considered theoretically. The nontrivial effects of bimolecular recombination are demonstrated in the Sn2S2P6:Sb crystals, providing an explanation of the optical sensitization process observed in photorefractive Sn2P2S6:Sb used for dynamic holography.

  13. Energies and E1, M1, E2, M2 transition rates for states of the 2s{sup 2}2p, 2s2p{sup 2}, and 2p{sup 3} configurations in boron-like ions between N III and Zn XXVI

    SciTech Connect

    Rynkun, P.; Joensson, P.; Gaigalas, G.; Froese Fischer, C.

    2012-07-15

    Energies, E1, M1, E2, M2 transition rates, line strengths, oscillator strengths, and lifetimes from relativistic configuration interaction calculations are reported for the states of the (1s{sup 2})2s{sup 2}2p, 2s2p{sup 2}, and 2p{sup 3} configurations in all boron-like ions between N III and Zn XXVI. Valence, core-valence, and core-core correlation effects were accounted for through single-double multireference (SD-MR) expansions to increasing sets of active orbitals.

  14. Formation and characterisation of the silver hydride nanocluster cation [Ag3H2((Ph2 P)2CH2)](+) and its release of hydrogen.

    PubMed

    Girod, Marion; Krstić, Marjan; Antoine, Rodolphe; MacAleese, Luke; Lemoine, Jérome; Zavras, Athanasios; Khairallah, George N; Bonačić-Koutecký, Vlasta; Dugourd, Philippe; O'Hair, Richard A J

    2014-12-08

    Multistage mass spectrometry and density functional theory (DFT) were used to characterise the small silver hydride nanocluster, [Ag3 H2 L](+) (where L=(Ph2 P)2 CH2 ) and its gas-phase unimolecular chemistry. Collision-induced dissociation (CID) yields [Ag2 HL](+) as the major product while laser-induced dissociation (LID) proceeds via H2 formation and subsequent release from [Ag3 H2 L](+) , giving rise to [Ag3 L](+) as the major product. Deuterium labelling studies on [Ag3 D2 L](+) prove that the source of H2 is from the hydrides and not from the ligand. Comparison of TD-DFT absorption patterns obtained for the optimised structures with action spectroscopy results, allows assignment of the measured features to structures of precursors and products. Molecular dynamics "on the fly" reveal that AgH loss is favoured in the ground state, but H2 formation and loss is preferred in the first excited state S1 , in agreement with CID and LID experimental findings. This indicates favourable photo-induced formation of H2 and subsequent release from [Ag3 H2 L](+) , an important finding in context of metal hydrides as a hydrogen storage medium, which can subsequently be released by heating or irradiation with light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Sn vacancies in photorefractive Sn2P2S6 crystals: An electron paramagnetic resonance study of an optically active hole trap

    NASA Astrophysics Data System (ADS)

    Golden, E. M.; Basun, S. A.; Evans, D. R.; Grabar, A. A.; Stoika, I. M.; Giles, N. C.; Halliburton, L. E.

    2016-10-01

    Electron paramagnetic resonance (EPR) is used to identify the singly ionized charge state of the Sn vacancy ( VSn - ) in single crystals of Sn2P2S6 (often referred to as SPS). These vacancies, acting as a hole trap, are expected to be important participants in the photorefractive effect observed in undoped SPS crystals. In as-grown crystals, the Sn vacancies are doubly ionized ( VSn 2 - ) with no unpaired spins. They are then converted to a stable EPR-active state when an electron is removed (i.e., a hole is trapped) during an illumination below 100 K with 633 nm laser light. The resulting EPR spectrum has g-matrix principal values of 2.0079, 2.0231, and 1.9717. There are resolved hyperfine interactions with two P neighbors and one Sn neighbor. The isotropic portions of these hyperfine matrices are 167 and 79 MHz for the two 31P neighbors and 8504 MHz for the one Sn neighbor (this latter value is the average for 117Sn and 119Sn). These VSn - vacancies are shallow acceptors with the hole occupying a diffuse wave function that overlaps the neighboring Sn2+ ion and (P2S6)4- anionic unit. Using a general-order kinetics approach, an analysis of isothermal decay curves of the VSn - EPR spectrum in the 107-115 K region gives an activation energy of 283 meV.

  16. In vivo evaluation of CaO-SiO2-P2O5-B2O3 glass-ceramics coating on Steinman pins.

    PubMed

    Lee, Jae Hyup; Hong, Kug Sun; Baek, Hae-Ri; Seo, Jun-Hyuk; Lee, Kyung Mee; Ryu, Hyun-Seung; Lee, Hyun-Kyung

    2013-07-01

    Surface coating using ceramics improves the bone bonding strength of an implant. We questioned whether a new type of glass-ceramics (BGS-7) coating (CaO-SiO2 -P2 O5 -B2 O3 ) would improve the osseointegration of Steinman pins (S-pins) both biomechanically and histomorphometrically. An in vivo study was performed using rabbits by inserting three S-pins into each iliac bone. The pins were 2.2-mm S-pins with a coating of 30-μm-thick BGS-7 and 550-nm-thick hydroxyapatite (HA), as opposed to an S-pin without coating. A tensile strength test and histomorphometrical evaluation was performed. In the 2-week group, the BGS-7 implant showed a significantly higher tensile strength than the S-pin. In the 4- and 8-week groups, the BGS-7 implants had significantly higher tensile strengths than the S-pins and HA implants. The histomorphometrical study revealed that the BGS-7 implant had a significantly higher contact ratio than the S-pin and HA implants in the 4-week group. The biomechanical and histomorphometrical tests showed that the BGS-7 coating had superior bone bonding properties than the groups without the coating from the initial stage of insertion. The BGS-7 coating of an S-pin will enhance the bone bonding strength, and there might also be an advantage in human bone bonding.

  17. Critical behavior near the Lifshitz point in Sn(2)P(2)(S(1 - x)Se(x))(6) ferroelectric semiconductors from thermal diffusivity measurements.

    PubMed

    Oleaga, A; Salazar, A; Kohutych, A A; Vysochanskii, Yu M

    2011-01-19

    The thermal diffusivity of the ferroelectric family Sn(2)P(2)(Se(x)S(1 - x))(6) (0 ≤ x ≤ 1) has been measured by a high-resolution ac photopyroelectric technique, using single crystals, with the aim of studying the evolution of the ferroelectric transition with Se doping. Its change from second order character to first order while passing the Lifshitz point (x approximately 0.28) has been evaluated, as well as the splitting of the transition at high Se concentrations. The critical behavior of the ferroelectric transition in terms of the different universality classes and their underlying physical dominant effects (tricriticality, long-range dipole interactions, Lifshitz point) has been discussed using thermal diffusivity measurements in the very close vicinity of the critical temperature. This study reveals that for Se concentrations around the Lifshitz point, long-range dipole interactions do not play a significant role and that the critical parameters are close to those predicted for the Lifshitz universality class.

  18. Observations of the O+ (2P-2D) 732 and 733 nm Thermospheric Airglow Emissions with the Wind Imaging Interferometer Leading to Atomic Oxygen Concentrations and ionospheric Winds

    NASA Astrophysics Data System (ADS)

    Shepherd, G. G.; Cho, Y. M.

    2014-12-01

    Remote sensing of airglow emission provides a powerful approach to the measurement of composition, temperature and winds in the thermosphere, on short and long time scales, including the responses to magnetic storms. Of the available emissions, one that has not been exploited to its full potential is the O+ (2P-2D) pair of doublets at 732.0 and 733.0 nm wavelength. This presentation is of recently analyzed results from WINDII, the Wind Imaging Interferometer on NASA's Upper Atmosphere Research Satellite, launched in 1991. WINDII is a Doppler Michelson interferometer with the capacity to measure airglow emission rates, Doppler temperatures from line widths and winds from Doppler shifts. One of the filters used to select specific airglow emissions was intended for measurement of the P1(2) line of the (8,3) Meinel band of OH at 731.63 nm but it also transmitted the O+ lines of interest. These have recently been retrieved from the data and are the basis of this presentation. The O+ emission is produced in the daytime, primarily from the photo-ionization of atomic oxygen and so knowing the solar flux the concentration of atomic oxygen can be determined. As a first step the variation of the emission rate on solar flux, solar zenith angle and conjugate photoelectron flux has been investigated, and preliminary results on atomic oxygen concentration are presented. In addition, ion winds can be determined from the Doppler shifts of the emission, which may be compared with the neutral winds obtained with WINDII from the atomic oxygen O(1S) and O(1D) emissions at 557.7 nm and 630.0 nm respectively. This possibility will allow the study of the interactions between the thermosphere and ionosphere for a wide range of conditions.

  19. Preparation of 3-D scaffolds in the SiO2-P2O5 system with tailored hierarchical meso-macroporosity.

    PubMed

    García, Ana; Izquierdo-Barba, Isabel; Colilla, Montserrat; de Laorden, Carlos López; Vallet-Regí, María

    2011-03-01

    Herein we report for the first time the synthesis of three-dimensional scaffolds in the binary system SiO2-P2O5 exhibiting different scales of porosity: (i) highly ordered mesopores with diameters of ca. 4 nm; (ii) macropores with diameters in the 30-80 μm range with interconnections of ca. 2-4 and 8-9 μm; and (iii) ultra-large macropores of ca. 400 μm. The hierarchical porosity of the resulting scaffolds makes them suitable for bone tissue engineering applications. The chemical nature and mesoporosity of these matrices would allow these scaffolds to act as local controlled delivery systems of biologically active molecules, such as certain drugs to treat bone pathologies. The synthetic method consists of the combination of a single-step sol-gel route in the presence of a surfactant as the mesostructure directing agent and a biomacromolecular polymer such as methylcellulose as the macrostructure template followed by rapid prototyping technique. An exhaustive study of the aging process as well as of the rheological properties of the slurry after methylcellulose addition has been carried out to obtain hierarchical meso-macroporosity. This study allows the establishment of the time period in which the slurry presents appropriate viscosity to be extruded during the rapid prototyping once the ink is prepared. The setting up of this manufacture process at the laboratory level is important from the industrial point of view when the large-scale production of scaffolds for bone tissue repair and regeneration is targeted. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  20. Structural and thermal characterization of CaO-MgO-SiO2-P2O5-CaF2 glasses

    SciTech Connect

    Kansal, Ishu; Goel, Ashutosh; Tulyaganov, Dilshat U.; Rajagopal, Raghu R.; Ferreira, Jose M.

    2012-08-01

    The paper presents the influence of varying CaO/MgO ratio on the structure and thermal properties of CaO-MgO-SiO2-P2O5-CaF2 glasses. A series of eight glass compositions in the glass forming region of diopside (CaMgSi2O6) - fluorapatite [Ca5(PO4)3F] - wollastonite (CaSiO3) ternary system have been designed and synthesized by varying diopside/wollastonite ratio in glasses. The as prepared melt-quenched glasses have been characterized for their structure by infrared spectroscopy (FTIR) and magic angle spinning (MAS)-nuclear magnetic resonance (NMR) spectroscopy. Silicon is predominantly present as Q2 (Si) species, while phosphorus tends to coordinate in orthophosphate environment in all the investigated glasses. The change in CaO/MgO ratio had an insignificant affect on the structure of glasses. The thermal sintering and crystallization parameters for the studied glasses have been obtained from differential thermal analysis (DTA) while crystalline phase fractions in the sintered glass-ceramics have been analyzed by X-ray diffraction adjoined with Rietveld refinement. Diopside, fluorapatite, wollastonite and pseudowollastonite have crystallized as the main crystalline phases in all the glass-ceramics with their content varying with respect to variation in CaO/MgO ratio in glasses. Scanning electron microscopy (SEM) has been used to shed light on the microstructure of glass-ceramics. The possible implications of structure and sintering behaviour of glasses on their bioactivity have been discussed.

  1. Influence of fluoride additions on biological and mechanical properties of Na2O-CaO-SiO2-P2O5 glass-ceramics.

    PubMed

    Li, H C; Wang, D G; Hu, J H; Chen, C Z

    2014-02-01

    Two series of Na2O-CaO-SiO2-P2O5 glass-ceramics doped with NH4HF2 (G-NH4HF2) or CaF2 (G-CaF2) have been prepared by sol-gel method. The glass-ceramic phase composition and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The mechanical properties and thermal expansion coefficient were measured by a microhardness tester, an electronic tensile machine and a thermal expansion coefficient tester. The structure difference between these two glass-ceramics was investigated by Fourier transform infrared spectroscopy (FTIR), and the in vitro bioactivity of the glass-ceramics was determined by in vitro simulated body fluid (SBF) immersion test. The hemolysis test, in vitro cytotoxicity test, systemic toxicity test and the implanted experiment in animals were used to evaluate the biocompatibility of the glass-ceramics. The mechanical properties of sample G-NH4HF2 are lower than that of sample G-CaF2, and the bioactivity of sample G-NH4HF2 is better than that of sample G-CaF2. The thermal expansion coefficients of these two glass-ceramics are all closer to that of Ti6Al4V. After 7 days of SBF immersion, apatites were induced on glass-ceramic surface, indicating that the glass-ceramics have bioactivity. The hemolysis test, in vitro cytotoxicity test and systemic toxicity test demonstrate that the glass-ceramics do not cause hemolysis reaction, and have no toxicity to cell and living animal. The implanted experiment in animals shows that bone tissue can form a good osseointegration with the implant after implantation for two months, indicating that the glass-ceramics are safe to serve as implants.

  2. WN4 longitudinal structure in the O (5S - 3P) and O+ (2P - 2D) ionospheric emissions as simulated by the C-IAM

    NASA Astrophysics Data System (ADS)

    Martynenko, Oleg; Ward, William E.; Shepherd, Gordon; Cho, Young-Min; Namgaladze, Alexander; Fomichev, Victor; McConnell, John; Semeniuk, Kirill; Beagley, Stephen

    A newly developed Canadian Ionosphere and Atmosphere Model (C-IAM) is introduced. It is being developed on the basis of two existing first principle models: the extended Canadian Middle Atmosphere Model (CMAM) and the ionospheric part of the Upper Atmosphere Model (UAM). The model extends from the surface to the inner magnetosphere and hence, is able to describe in a self-consistent way how lower atmosphere dynamical variability propagates into and affects the upper atmosphere and ionosphere. The C-IAM was applied to model the spatial structure of two different ionospheric emissions: the nighttime 135.6 nm O ( (5) S - (3) P) and daytime 732 nm O (+) ( (2) P - (2) D) emissions. The IMAGE satellite observations showed a wave number 4 (WN4) longitudinal structure in the 135.6 nm ionospheric emission emanating from the equatorial ionization anomaly at 350-400 km near 20:00 local time at each longitude. C-IAM simulations are in a good agreement with the observations. Model result analysis reveals that the main mechanism for generating the WN4 structure in the 135.6 nm emission is a modification of the ionospheric dynamo field caused by longitudinal variation of the zonal wind due to waves penetrating from the lower atmosphere. It was also shown, that during geomagnetic storms and substorms the high-latitudinal electric field fully suppresses the dynamo, so that the emission intensity dramatically decreases and the WN4 structure does not appear. The 732 nm emission simulated with the C-IAM also reveals the WN4 structure. Similar to the 135.6 nm emission, this structure is caused by waves penetrating from the lower atmosphere. However, the mechanism of excitation is quite different. The 732 nm emission is produced by the instant local ionization and excitation, and, hence, its variation is caused by the neutral density variability in the F2 region (above 200 km) without any involvement of the electric field effects. Correspondingly, latitudinal distribution of this

  3. Determination of the 1s2{\\ell }2{{\\ell }}^{\\prime } state production ratios {{}^{4}P}^{o}/{}^{2}P, {}^{2}D/{}^{2}P and {{}^{2}P}_{+}/{{}^{2}P}_{-} from fast (1{s}^{2},1s2s\\,{}^{3}S) mixed-state He-like ion beams in collisions with H2 targets

    NASA Astrophysics Data System (ADS)

    Benis, E. P.; Zouros, T. J. M.

    2016-12-01

    New results are presented on the ratio {R}m={σ }{T2p}( {}4P)/{σ }{T2p}({}2P) concerning the production cross sections of Li-like 1s2s2p quartet and doublet P states formed in energetic ion-atom collisions by single 2p electron transfer to the metastable 1s2s {}3S component of the He-like ion beam. Spin statistics predict a value of R m = 2 independent of the collision system in disagreement with most reported measurements of {R}m≃ 1{--}9. A new experimental approach is presented for the evaluation of R m having some practical advantages over earlier approaches. It also allows for the determination of the separate contributions of ground- and metastable-state beam components to the measured spectra. Applying our technique to zero-degree Auger projectile spectra from 4.5 MeV {{{B}}}3+ (Benis et al 2002 Phys. Rev. A 65 064701) and 25.3 MeV {{{F}}}7+ (Zamkov et al 2002 Phys. Rev. A 65 062706) mixed state (1{s}2 {}1S,1s2s {}3S) He-like ion collisions with H2 targets, we report new values of {R}m=3.5+/- 0.4 for boron and {R}m=1.8+/- 0.3 for fluorine. In addition, the ratios of {}2D/{}2P and {{}2P}+/{{}2P}- populations from either the metastable and/or ground state beam component, also relevant to this analysis, are evaluated and compared to previously reported results for carbon collisions on helium (Strohschein et al 2008 Phys. Rev. A 77 022706) including a critical comparison to theory.

  4. Relativistic electron-correlation on the 2p-2s transitions in Li-like to F-like Xe ions

    NASA Astrophysics Data System (ADS)

    Hao, Liang-huan; Liu, Jing-jing; Kang, Xiao-ping

    2016-06-01

    Energy levels, wavelengths, transition rates and line strengths are reported for transitions in Li-like to F-like Xe ions, Xe LII-XLVI. For the calculations, a fully relativistic GRASP2k code based on the multiconfiguration Dirac-Hartree-Fock (MCDHF) method has been adopted, Valence and core-Valence correlation effects were accounted for through single- and double-excitation expansions to increasing sets of active orbitals. The fine-structure energy levels and wavelengths are compared with experimental data and with values from other calculations. The calculated values including core-valence correlation are found to be similar and compare very well with other theoretical and experimental values for Xe ions. Our calculated wavelengths for Li-, Be- and B-like ions are much more precise than some available theoretical data and reveal significant shortcomings of the various theoretical predictions.

  5. Proton Environments in Biomimetic Calcium Phosphates Formed from Mesoporous Bioactive CaO-SiO2-P2O5 Glasses in Vitro: Insights from Solid-State NMR.

    PubMed

    Mathew, Renny; Turdean-Ionescu, Claudia; Yu, Yang; Stevensson, Baltzar; Izquierdo-Barba, Isabel; García, Ana; Arcos, Daniel; Vallet-Regí, María; Edén, Mattias

    2017-06-22

    When exposed to body fluids, mesoporous bioactive glasses (MBGs) of the CaO-SiO2-P2O5 system develop a bone-bonding surface layer that initially consists of amorphous calcium phosphate (ACP), which transforms into hydroxy-carbonate apatite (HCA) with a very similar composition as bone/dentin mineral. Information from various (1)H-based solid-state nuclear magnetic resonance (NMR) experiments was combined to elucidate the evolution of the proton speciations both at the MBG surface and within each ACP/HCA constituent of the biomimetic phosphate layer formed when each of three MBGs with distinct Ca, Si, and P contents was immersed in a simulated body fluid (SBF) for variable periods between 15 min and 30 days. Directly excited magic-angle-spinning (MAS) (1)H NMR spectra mainly reflect the MBG component, whose surface is rich in water and silanol (SiOH) moieties. Double-quantum-single-quantum correlation (1)H NMR experimentation at fast MAS revealed their interatomic proximities. The comparatively minor H species of each ACP and HCA component were probed selectively by heteronuclear (1)H-(31)P NMR experimentation. The initially prevailing ACP phase comprises H2O and "nonapatitic" HPO4(2-)/PO4(3-) groups, whereas for prolonged MBG soaking over days, a well-progressed ACP → HCA transformation was evidenced by a dominating O(1)H resonance from HCA. We show that (1)H-detected (1)H → (31)P cross-polarization NMR is markedly more sensitive than utilizing powder X-ray diffraction or (31)P NMR for detecting the onset of HCA formation, notably so for P-bearing (M)BGs. In relation to the long-standing controversy as to whether bone mineral comprises ACP and/or forms via an ACP precursor, we discuss a recently accepted structural core-shell picture of both synthetic and biological HCA, highlighting the close relationship between the disordered surface layer and ACP.

  6. Optical phase conjugation of picosecond pulses at 1.06 mum in Sn(2)P(2)S(6):Te for wavefront correction in high-power Nd-doped amplifier systems.

    PubMed

    Bach, Tobias; Nawata, Kouji; Jazbinsek, Mojca; Omatsu, Takashige; Günter, Peter

    2010-01-04

    We report, for the first time to our knowledge, on picosecondpulse optical phase conjugation using photorefractive Sn(2)P(2)S(6) crystals. For 7.2-ps pulses at 1.06 mum, we have achieved phase-conjugate reflectivities of up to 45% with very fast build-up times, about 15 ms at an intensity of 23 W/cm(2) using Te-doped Sn(2)P(2)S(6). We furthermore demonstrate aberration-free 5 W optical output of 8-ps pulses at 1.06 mum from a side pumped Nd:YVO(4) amplifier using the Sn(2)P(2)S(6)-based phase-conjugate feedback.

  7. Current models for starch synthesis and the sugary enhancer1 (se1) mutation in Zea mays.

    PubMed

    Schultz, Jennifer A; Juvik, John A

    2004-06-01

    Among the desirable quality traits essential for commercial production of fresh or processed sweet corn, kernel sugar content is universally important. In sweet corn genotypes the primary kernel sugar is sucrose, which is elevated at the expense of starch, particularly amylopectin. Sweet corn mutations have been traditionally divided into two classes. Generally speaking, class one mutations affect cytosolic reactions early in the process of starch synthesis, before starch is synthesized, and class two mutations affect reactions within the amyloplast directly involving starch granule assembly. Two widely used but previously unclassified mutations are sugary1 (su1) and sugary enhancer1 (se1). The se1 gene is a recessive modifier of su1; therefore, both genes require mutual discussion. This review provides current information about the su1 and se1 maize endosperm mutations and describes evidence further supporting previous suggestions that they fit criteria for categorization as class two mutants [Science 151 (1966) 341]. Information on the genetics and phenotype of se1 will be summarized and the hypothesized role of the se1 gene product discussed within the context of current models for starch synthesis in Zea mays L.

  8. One-pot carbanionic synthesis of P1,P2-diglycosyl, P1,P1,P2-triglycosyl, and P1,P1,P2,P2-tetraribosyl methylenediphosphonates.

    PubMed

    Grison, Claude; Chibli, Hicham; Barthès, Nicolas; Coutrot, Philippe

    2006-10-13

    Novel lithiated carbanions derived from ethyl glycosyl- and diglycosyl methylphosphonates were used in a direct and convenient synthesis of P1,P2-diglycosyl, P1,P1,P2-triglycosyl, and P1,P1,P2,P2-tetraribosyl methylenediphosphonates involving a one-pot methylidenediphosphonylation of sugars.

  9. [Co(η5-P5){η2-P2H(mes)}]2-: a phospha-organometallic complex obtained by the transition-metal-mediated activation of the heptaphosphide trianion.

    PubMed

    Knapp, Caroline M; Westcott, Bethan H; Raybould, Melissa A C; McGrady, John E; Goicoechea, Jose M

    2012-09-03

    A carbon copy: The chemical activation of the heptaphosphide trianion with [Co(PEt(2)Ph)(2)(mes)(2)] (see picture; 1) yields the novel phospha-organometallic complex [Co(η(5)-P(5)){η(2)-P(2)H(mes)}](2-) (2). The reaction product maintains the nuclearity of the parent cluster, but extensive cage fragmentation takes place to yield a diamagnetic "inorganometallic" cobalt complex. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Synthesis and characterization of fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] complexes (M = Re, (99m)Tc) with acetylacetone and curcumin as OO donor bidentate ligands.

    PubMed

    Triantis, Charalampos; Tsotakos, Theodoros; Tsoukalas, Charalampos; Sagnou, Marina; Raptopoulou, Catherine; Terzis, Aris; Psycharis, Vassilis; Pelecanou, Maria; Pirmettis, Ioannis; Papadopoulos, Minas

    2013-11-18

    The synthesis and characterization of neutral mixed ligand complexes fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] (M = Re, (99m)Tc), with deprotonated acetylacetone or curcumin as the OO donor bidentate ligands and a phosphine (triphenylphosphine or methyldiphenylphosphine) as the monodentate P ligand, is described. The complexes were synthesized through the corresponding fac-[M(CO)3(H2O)(OO)] (M = Re, (99m)Tc) intermediate aqua complex. In the presence of phosphine, replacement of the H2O molecule of the intermediate complex at room temperature generates the neutral tricarbonyl monophosphine fac-[Re(CO)3(P)(OO)] complex, while under reflux conditions further replacement of the trans to the phosphine carbonyl generates the new stable dicarbonyl bisphosphine complex cis-trans-[Re(CO)2(P)2(OO)]. The Re complexes were fully characterized by elemental analysis, spectroscopic methods, and X-ray crystallography showing a distorted octahedral geometry around Re. Both the monophosphine and the bisphosphine complexes of curcumin show selective binding to β-amyloid plaques of Alzheimer's disease. At the (99m)Tc tracer level, the same type of complexes, fac-[(99m)Tc(CO)3(P)(OO)] and cis-trans-[(99m)Tc(CO)2(P)2(OO)], are formed introducing new donor combinations for (99m)Tc(I). Overall, β-diketonate and phosphine constitute a versatile ligand combination for Re(I) and (99m)Tc(I), and the successful employment of the multipotent curcumin as β-diketone provides a solid example of the pharmacological potential of this system.

  11. The IL4-VNTR P1 Allele, IL4-VNTR P2P2 Genotype, and IL4-VNTR_IL6-174CG P2P1-GG Genotype Are Associated with an Increased Risk of Brucellosis.

    PubMed

    Gunal, Ozgur; Yigit, Serbulent; Yalcın, Arzu Didem; Celik, Betul; Barut, Sener; Demir, Osman; Ates, Omer; Duygu, Fazilet; Kaya, Safak; Rustemoglu, Aydin; Sezer, Ozlem

    2017-01-24

    In this study, associations between IL-4, IL-6, and macrophage migration inhibitory factor (MIF) polymorphisms and susceptibility to brucellosis were investigated. Consecutive adult patients with no known treatment against brucellosis and who did not have any other autoimmune and/or chronic disorders, were included in this study (n = 120, Group I). Age and sex-matched controls who had no other autoimmune and/or chronic disorders were also included (n = 120, healthy volunteers, Group II). The IL4_P2P2 genotype, IL4_P1 allele, and IL4_variable number of tandem repeats (VNTR)_IL6-174CG compound genotype were found to be more frequent in the patient group than in control subjects. There were significant differences between the patients and controls with respect to the frequencies of the IL4_P2P2 genotype (77.5% versus 87.5%; p = 0.001; OR, 0.36; 95% confidence interval [CI], 0.21-0.62) and the IL4_P1 allele (12.1% versus 6.7%; p = 0.030; OR, 0.92; CI, 1.02-3.64). The IL4-VNTR_IL6-174CG compound genotype was also present at a significantly higher frequency in the patient group than in control subjects (11.7% versus 4.2%; p = 0.027, OR, 3.04; CI, 1.06-8.68). No statistically significant differences in the frequencies of the IL-6-174, MIF-173, IL-4_P1P1, and IL4_P2P1 genotypes were observed between patients and control subjects. The IL4_VNTR P1 allele, P2P2 genotypes, and IL4-VNTR_IL6-174CG P2P1-GG genotypes are common in southern Turkey, and carriers of these polymorphisms are susceptible to brucellosis.

  12. Comparison of fusion rate and clinical results between CaO-SiO2-P2O5-B2O3 bioactive glass ceramics spacer with titanium cages in posterior lumbar interbody fusion.

    PubMed

    Lee, Jae Hyup; Kong, Chang-Bae; Yang, Jae Jun; Shim, Hee-Jong; Koo, Ki-Hyoung; Kim, Jeehyoung; Lee, Choon-Ki; Chang, Bong-Soon

    2016-11-01

    The CaO-SiO2-P2O5-B2O3 glass ceramics spacer generates chemical bonding to adjacent bones with high mechanical stability to produce a union with the end plate, and ultimately stability. The authors aimed to compare the clinical efficacy and safety of CaO-SiO2-P2O5-B2O3 glass ceramics with a titanium cage that is widely used for posterior lumbar interbody fusion (PLIF) surgery in the clinical field. This is a prospective, stratified randomized, multicenter, single-blinded, comparator-controlled non-inferiority trial. The present study was conducted in four hospitals and enrolled a total of 86 patients between 30 and 80 years of age who required one-level PLIF due to severe spinal stenosis, spondylolisthesis, or huge disc herniation. The Oswestry Disability Index (ODI), Short Form-36 Health Survey (SF-36), and pain visual analog scale (VAS) were assessed before surgery and at 3, 6, and 12 months after surgery. The spinal fusion rate was assessed at 6 and 12 months after surgery. The spinal fusion rate and the area of fusion, subsidence of each CaO-SiO2-P2O5-B2O3 glass ceramics and titanium cage, and the extent of osteolysis were evaluated using a dynamic plain radiography and a three-dimensional computed tomography at 12 months after surgery. The present study was supported by BioAlpha, and some authors (JHL, C-KL, and B-SC) have stock ownership (<10,000 US dollars). From the plain radiography results, the 6-month fusion rates for the bioactive glass ceramics group and the titanium group were 89.7% and 91.4%, respectively. In addition, the 12-month fusion rates based on CT scan were 89.7% and 91.2%, respectively, showing no significant difference. However, the bone fusion area directly attached to the end plate of either bioactive glass ceramics or the titanium cage was significantly higher in the bioactive glass ceramics group than in the titanium group. The ODI, SF-36, back pain, and lower limb pain in both groups significantly improved after surgery, with no

  13. Relativistic electron correlation, quantum electrodynamics, and the lifetime of the 1s(2)2s(2)2p2p0(3/2) level in boronlike argon.

    PubMed

    Lapierre, A; Jentschura, U D; Crespo López-Urrutia, J R; Braun, J; Brenner, G; Bruhns, H; Fischer, D; González Martínez, A J; Harman, Z; Johnson, W R; Keitel, C H; Mironov, V; Osborne, C J; Sikler, G; Soria Orts, R; Shabaev, V; Tawara, H; Tupitsyn, I I; Ullrich, J; Volotka, A

    2005-10-28

    The lifetime of the Ar13+ 1s(2)2s(2)2p2p0(3/2) metastable level was determined at the Heidelberg Electron Beam Ion Trap to be 9.573(4)(5). The accuracy level of one per thousand makes this measurement sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM) and to relativistic electron-electron correlation effects like the frequency-dependent Breit interaction. Theoretical predictions, adjusted for the EAMM, cluster about a lifetime that is approximately shorter than our experimental result.

  14. Viscosity and Structure of CaO-SiO2-P2O5-FetO System with Varying P2O5 and FeO Content

    NASA Astrophysics Data System (ADS)

    Diao, Jiang; Gu, Pan; Liu, De-Man; Jiang, Lu; Wang, Cong; Xie, Bing

    2017-10-01

    A rotary viscosimeter and Raman spectrum were employed to measure the viscosity and structural information of the CaO-SiO2-P2O5-FetO system at 1673 K. The experimental data have been compared with the calculated results using different viscosity models. It shows that the National Physical Laboratory (NPL) and Pal models fit the CaO-SiO2-P2O5-FeOt system better. With the P2O5 content increasing from 5% to 14%, the viscosity increases from 0.12 Pa s to 0.27 Pa s. With the FeO content increasing from 30% to 40%, the viscosity decreases from 0.21 Pa s to 0.12 Pa s. Increasing FeO content makes the complicated molten melts become simple, and increasing P2O5 content will complicate the molten melts. The linear relation between viscosity and structure parameter Q(Si + P) was obtained by regression analysis. The calculated viscosity by using the optimized NPL and Pal model are almost identical with the fitted values.

  15. Viscosity and Structure of CaO-SiO2-P2O5-FetO System with Varying P2O5 and FeO Content

    NASA Astrophysics Data System (ADS)

    Diao, Jiang; Gu, Pan; Liu, De-Man; Jiang, Lu; Wang, Cong; Xie, Bing

    2017-07-01

    A rotary viscosimeter and Raman spectrum were employed to measure the viscosity and structural information of the CaO-SiO2-P2O5-FetO system at 1673 K. The experimental data have been compared with the calculated results using different viscosity models. It shows that the National Physical Laboratory (NPL) and Pal models fit the CaO-SiO2-P2O5-FeOt system better. With the P2O5 content increasing from 5% to 14%, the viscosity increases from 0.12 Pa s to 0.27 Pa s. With the FeO content increasing from 30% to 40%, the viscosity decreases from 0.21 Pa s to 0.12 Pa s. Increasing FeO content makes the complicated molten melts become simple, and increasing P2O5 content will complicate the molten melts. The linear relation between viscosity and structure parameter Q(Si + P) was obtained by regression analysis. The calculated viscosity by using the optimized NPL and Pal model are almost identical with the fitted values.

  16. Deformed lattice states in a Zn{sub 0.9}V{sub 0.1}Se cubic crystal

    SciTech Connect

    Maksimov, V. I. Dubinin, S. F.; Surkova, T. P.; Parkhomenko, V. D.

    2016-01-15

    Neutron scattering patterns have been recorded for a bulk Zn{sub 0.9}V{sub 0.1}Se cubic crystal at room temperature; they are indicative of macroscopic deformation in the material and its significant inhomogeneity. Specific features of the previously found state, preceding the fcc ↔ hcp structural transformation of the sphalerite lattice upon strong destabilization induced by vanadium ions in the doped ZnSe matrix, are discussed taking into account the data obtained.

  17. Absolute cross sections for excitation of the 2s 2S-->2p 2P transition in B2+ and for electron-impact single ionization of B2+

    NASA Astrophysics Data System (ADS)

    Woitke, O.; Djurić, N.; Dunn, G. H.; Bannister, M. E.; Smith, A. C.; Wallbank, B.; Badnell, N. R.; Pindzola, M. S.

    1998-12-01

    Absolute cross sections for electron-impact excitation of the 2s 2S-->2p 2P transition of B2+ measured between 5.4 and 7.0 eV are presented. The results are in good agreement with the R-matrix-with-pseudostates (RMPS) calculation of Marchalant et al. [J. Phys. B 30, L435 (1997)]. Also presented are cross sections for electron-impact single ionization of B2+, including measurements between 25 and 200 eV and calculations using the RMPS and time-dependent close-coupling methods. The measured ionization cross sections are about 14% higher near the peak than previous measurements by Crandall et al. [Phys. Rev. A 34, 1757 (1986)], but agree well with experimental data of Hofmann et al. [Z. Phys. D 16, 113 (1990)] and with the present and other theoretical predictions.

  18. Conductance simulation of the purinergic P2X2, P2X4, and P2X7 ionic channels using a combined Brownian dynamics and molecular dynamics approach.

    PubMed

    Turchenkov, Dmitry A; Bystrov, Vladimir S

    2014-08-07

    This paper investigates the application of an original combined approach of molecular and Brownian dynamic methods with quantum chemistry calculations for modeling the process of conductance of ion channels using purinergic P2X family receptors P2X2, P2X4, and P2X7 as a case study. A simplified model of the ionic channel in the lipid bilayer has been developed. A high level of conductance (30 pS) of P2X2 ionic channel together with the key role of Asp349 in forming the selectivity filter of P2X2 has been shown by using this approach. Calculated P2X2 permeability to monovalent cations Li(+), Na(+), and K(+) conforms to the free diffusion coefficient of these ions, which shows the low selectivity of P2X2 ionic channel.

  19. Effects of Substitution of K2O for Na2O on the Bioactivity of CaO-Na2O-SiO2-P2O5 glasses

    NASA Astrophysics Data System (ADS)

    Kim, Taehee; Hwang, Chawon; Gwoo, Donggun; Park, Hoyyul; Ryu, Bong-Ki

    2012-10-01

    The compositional dependences of bioactivity, thermal properties, atomic structure, and surface morphology have been investigated in the CaO-Na2O-SiO2-P2O5 system; this system is known as a bioglass. 45S5 Bioglass® is known to be a general and highly bioactive material. However, the bioactivity of this glassy material is expected to be improved by modifying the alkali-metal composition. Thermal properties, density, and molar volume were measured to investigate the structural packing. FT-IR spectra and X-ray diffraction were used to confirm the structures of these glasses. The morphology was examined using field emission electron microscopy, and the formation of a Ca-P layer was studied using an energy-dispersive system. This study shows that the tendency to form a calcium phosphate layer is increased with the substitution of K2O for Na2O.

  20. pH-Dependent solution dynamics of a manganese(II) polyoxometalate, [Mn4(H2O)2(P2W15O56)2](16-), and [Mn(H2O)6](2+).

    PubMed

    Sharma, Rupali; Zhang, Jie; Ohlin, C André

    2015-11-28

    The aqueous reaction dynamics of the manganese(II)-functionalised Wells-Dawson polyoxometalate [Mn4(H2O)2(P2W15O56)2](16-) has been determined as a function of pH using variable temperature (17)O NMR, and compared with that of the well-studied monomeric manganese(II) hexa-aqua ion, [Mn(H2O)6](2+). While the rate of aquo-ligand exchange on the hexa-aqua ion remains independent of pH in the range 3.2-6.0, the rate of water exchange of the polyoxometalate ion varies by a factor of fifteen, from 1.98 × 10(7) s(-1) at pH 3.2 to 1.3 × 10(6) s(-1) at pH 6.0. This decrease in the rate of exchange correlates with the deprotonation of the polyoxometalate framework.

  1. Effect of ZnO addition on bioactive CaO-SiO2-P2O5-CaF2 glass-ceramics containing apatite and wollastonite.

    PubMed

    Kamitakahara, M; Ohtsuki, C; Inada, H; Tanihara, M; Miyazaki, T

    2006-07-01

    Some ceramics show bone-bonding ability, i.e. bioactivity. Apatite formation on ceramics is an essential condition to bring about direct bonding to living bone when implanted into bony defects. A controlled surface reaction of the ceramic is an important factor governing the bioactivity and biodegradation of the implanted ceramic. Among bioactive ceramics, glass-ceramic A-W containing apatite and wollastonite shows high bioactivity, as well as high mechanical strength. In this study, glass-ceramics containing zinc oxide were prepared by modification of the composition of the glass-ceramic A-W. Zinc oxide was selected to control the reactivity of the glass-ceramics since zinc is a trace element that shows stimulatory effects on bone formation. Glass-ceramics were prepared by heat treatment of glasses with the general composition: xZnOx(57.0-x)CaOx35.4SiO(2)x7.2P(2)O(5)x0.4CaF(2) (where x=0-14.2mol.%). Addition of ZnO increased the chemical durability of the glass-ceramics, resulting in a decrease in the rate of apatite formation in a simulated body fluid. On the other hand, the release of zinc from the glass-ceramics increased with increasing ZnO content. Addition of ZnO may provide bioactive CaO-SiO(2)-P(2)O(5)-CaF(2) glass-ceramics with the capacity for appropriate biodegradation, as well as enhancement of bone formation.

  2. Mechanical and biological properties of two types of bioactive bone cements containing MgO-CaO-SiO2-P2O5-CaF2 glass and glass-ceramic powder.

    PubMed

    Tamura, J; Kawanabe, K; Kobayashi, M; Nakamura, T; Kokubo, T; Yoshihara, S; Shibuya, T

    1996-01-01

    In this study two types of bioactive bone cement containing either MgO-CaO-SiO2-P2O5-CaF2 glass (type A) or glass-ceramic powder (type B) were made to evaluate the effect of the crystalline phases on their mechanical and biological properties. Type A bone cement was produced from glass powder and bisphenol-a-glycidyl methacrylate (BIS-GMA) resin, and type B from glass-ceramic powder containing apatite and wollastonite crystals and BIS-GMA resin. Glass or glass-ceramic powder (30, 50, 70, and 80 by wt %) was added to the cement. The compressive strength of type A (153-180 MPa) and B (167-194 MPa) cement were more than twice that of conventional polymethylmethacrylate (PMMA) cement (68 MPa). Histological examination of rat tibiae showed that all the bioactive cements formed direct contact with the bone. A reactive layer was seen at the bone-cement interface. In specimens with type A cement the reactive layer consisted of two layers, a radiopaque outer layer (Ca-P-rich layer) and a relatively radiolucent inner layer (low-calcium-level layer). With type B cement, although the Ca-P-rich layer was seen, the radiolucent inner layer was absent. Up to 26 weeks there was progressive bone formation around each cement (70 wt %) and no evidence of biodegradation. The mechanical and biological properties of the cements were compared with those of a previously reported bone cement containing MgO-free CaO-SiO2-P2O5-CaF2 glass powder (designated type C).

  3. Dicobalt-μ-oxo polyoxometalate compound, [(α(2)-P2W17O61Co)2O](14-): a potent species for water oxidation, C-H bond activation, and oxygen transfer.

    PubMed

    Barats-Damatov, Delina; Shimon, Linda J W; Weiner, Lev; Schreiber, Roy E; Jiménez-Lozano, Pablo; Poblet, Josep M; de Graaf, Coen; Neumann, Ronny

    2014-02-03

    High-valent oxo compounds of transition metals are often implicated as active species in oxygenation of hydrocarbons through carbon-hydrogen bond activation or oxygen transfer and also in water oxidation. Recently, several examples of cobalt-catalyzed water oxidation have been reported, and cobalt(IV) species have been suggested as active intermediates. A reactive species, formally a dicobalt(IV)-μ-oxo polyoxometalate compound [(α2-P2W17O61Co)2O](14-), [(POMCo)2O], has now been isolated and characterized by the oxidation of a monomeric [α2-P2W17O61Co(II)(H2O)](8-), [POMCo(II)H2O], with ozone in water. The crystal structure shows a nearly linear Co-O-Co moiety with a Co-O bond length of ∼1.77 Å. In aqueous solution [(POMCo)2O] was identified by (31)P NMR, Raman, and UV-vis spectroscopy. Reactivity studies showed that [(POMCo)2O]2O] is an active compound for the oxidation of H2O to O2, direct oxygen transfer to water-soluble sulfoxides and phosphines, indirect epoxidation of alkenes via a Mn porphyrin, and the selective oxidation of alcohols by carbon-hydrogen bond activation. The latter appears to occur via a hydrogen atom transfer mechanism. Density functional and CASSCF calculations strongly indicate that the electronic structure of [(POMCo)2O]2O] is best defined as a compound having two cobalt(III) atoms with two oxidized oxygen atoms.

  4. Methanocarba Modification of Uracil and Adenine Nucleotides: High Potency of Northern Ring Conformation at P2Y1, P2Y2, P2Y4, and P2Y11 but Not P2Y6 Receptors

    PubMed Central

    Kim, Hak Sung; Ravi, R. Gnana; Marquez, Victor E.; Maddileti, Savitri; Wihlborg, Anna-Karin; Erlinge, David; Malmsjö, Malin; Boyer, José L.; Harden, T. Kendall; Jacobson, Kenneth A.

    2016-01-01

    The potency of nucleotide antagonists at P2Y1 receptors was enhanced by replacing the ribose moiety with a constrained carbocyclic ring (Nandanan, et al. J. Med. Chem. 2000, 43, 829—842). We have now synthesized ring-constrained methanocarba analogues (in which a fused cyclopropane moiety constrains the pseudosugar ring) of adenine and uracil nucleotides, the endogenous activators of P2Y receptors. Methanocarba-adenosine 5′-triphosphate (ATP) was fixed in either a Northern (N) or a Southern (S) conformation, as defined in the pseudorotational cycle. (N)-Methanocarba-uridine was prepared from the 1-amino-pseudosugar ring by treatment with β-ethoxyacryloyl cyanate and cyclization to form the uracil ring. Phosphorylation was carried out at the 5′-hydroxyl group through a multistep process: Reaction with phosphoramidite followed by oxidation provided the 5′-monophosphates, which then were treated with 1,1′-carbonyldiimidazole for condensation with additional phosphate groups. The ability of the analogues to stimulate phospholipase C through activation of turkey P2Y1 or human P2Y1, P2Y2, P2Y4, P2Y6, and P2Y11 receptors stably expressed in astrocytoma cells was measured. At recombinant human P2Y1 and P2Y2 receptors, (N)-methanocarba-ATP was 138- and 41-fold, respectively, more potent than racemic (S)-methanocarba-ATP as an agonist. (N)-methanocarba-ATP activated P2Y11 receptors with a potency similar to ATP. (N)-Methanocarba-uridine 5′-triphosphate (UTP) was equipotent to UTP as an agonist at human P2Y2 receptors and also activated P2Y4 receptors with an EC50 of 85 nM. (N)-Methanocarba-uridine 5′-diphosphate (UDP) was inactive at the hP2Y6 receptor. The vascular effects of (N)-methanocarba-UTP and (N)-methanocarba-UDP were studied in a model of the rat mesenteric artery. The triphosphate was more potent than UTP in inducing a dilatory P2Y4 response (pEC50 = 6.1 ± 0.2), while the diphosphate was inactive as either an agonist or antagonist in a P2Y6

  5. Bone bonding behavior of MgO-CaO-SiO2-P2O5-CaF2 glass (mother glass of A.W-glass-ceramics).

    PubMed

    Kitsugi, T; Yamamuro, T; Nakamura, T; Kokubo, T

    1989-06-01

    In this study, it was found that a Ca-P layer and a Si layer were formed on the interface of the mother glass of apatite-wollastonite containing glass-ceramics (designated AW) and bone tissue. The dissolution of Si, Ca, and P from glass (MgO-CaO-SiO2-P2O5-CaF2) is necessary to form a chemical film (a Si layer and a Ca-P layer). The three kinds of glasses used were 1) a mirror surface of the mother glass (MgO 4.6, CaO 44.9, SiO2 34.2, P2O5 16.3, CaF 0.5 weight ratio) of AW (designated G-AW (mirror], 2) an abraded surface of G-AW (designated G-AW (#2000)), 3) a mirror surface SiO2 glass (designated G-Si, 100% SiO2). The glass plates (15 mm x 10 mm x 2 mm) were implanted into the metaphysis of tibia of mature male rabbits for 10 and 25 weeks. The failure load, when an implant detached from the bone or when the bone itself broke, was measured by a detaching test and the interface of glass/bone was observed by SEM-EPMA. Failure loads in G-Si, G-AW (mirror), and G-AW (#2000) 10 weeks after implantation were 0.18 +/- 0.24, 3.06 +/- 1.29, and 2.94 +/- 1.77 kg, respectively. Those in G-Si, G-AW (mirror), and G-AW (#2000) 25 weeks after implantation were 1.30 +/- 1.18, 3.88 +/- 1.06, and 3.55 +/- 1.51, respectively. The failure loads in G-Si vs. G-AW (mirror) and those in G-Si vs. G-AW (#2000) differed significantly (P less than 0.01). There were no significant differences in the failure load according to the surface roughness of G-AW. As shown by SEM-EPMA observation, a Si layer next to G was adjacent to a Ca-P layer next to the bone. The chemical film showed no increase in thickness as time passed. A Ca-P layer did not form on the interface of Si-G and bone.

  6. Influence of heat treatments upon the mechanical properties and in vitro bioactivity of ZrO2-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics.

    PubMed

    Li, Huan-Cai; Wang, Dian-Gang; Meng, Xiang-Guo; Chen, Chuan-Zhong

    2014-09-01

    Zirconia-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics are prepared using sintering techniques, and a series of heat treatment procedures are designed to obtain a glass-ceramic with improved properties. The crystallization behavior, phase composition, and morphology of the glass-ceramics are characterized. The bending strength, elastic modulus, fracture toughness, and microhardness of the glass-ceramics are investigated, and the effect mechanism of heat treatments upon the mechanical properties is discussed. The bioactivity of glass-ceramics is then evaluated using the in vitro simulated body fluid (SBF) soaking test, and the mechanism whereby apatite forms on the glass-ceramic surfaces in the SBF solution is discussed. The results indicate that the main crystal phase of the G-24 sample undergoing two heat treatment procedures is Ca5(PO4)3F (fluorapatite), and those of the G-2444 sample undergoing four heat treatment procedures are Ca5(PO4)3F and β-CaSiO3 (β-wollastonite). The heat treatment procedures are found to greatly influence the mechanical properties of the glass-ceramic, and an apatite layer is induced on the glass-ceramic surface after soaking in the SBF solution.

  7. Effects of sodium and potassium ions on a novel SeO2-B2O3-SiO2-P2O5-CaO bioactive system

    NASA Astrophysics Data System (ADS)

    Trandafir, D. L.; Ponta, O.; Ciceo-Lucacel, R.; Simon, V.

    2015-01-01

    The study is focused on Na2O and/or K2O influence on a new sol-gel derived SeO2-B2O3-SiO2-P2O5-CaO bioactive system. The structural changes induced by Na2O and/or K2O addition were correlated with the samples behavior in simulated biological media. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the structure and the type of the chemical bonds. The morphology of the samples was characterized through scanning electron microscopy (SEM). XRD results pointed out a prevalent vitreous structure with an incipient hydroxyapatite (HA) crystalline phase. FTIR results revealed a complex network consisting of silicate, phosphate and borate units, as well as the development of both A- and B-type of carbonate-substituted HA. The bioactivity of the samples was tested in vitro following the evolution of the apatite layers self-assembled on the samples surface in simulated body fluid. Their biocompatibility was investigated after samples surface functionalization with protein. The results indicate that sodium and potassium addition improves the biocompatibility by enhancement of protein adherence on samples surface and without to prevent the samples bioactivity.

  8. Effect of ZrO(2) additions on the crystallization, mechanical and biological properties of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics.

    PubMed

    Li, H C; Wang, D G; Meng, X G; Chen, C Z

    2014-06-01

    A series of ZrO(2) doped MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics were obtained by sintering method. The crystallization behavior, phase composition, morphology and structure of glass-ceramics were characterized. The bending strength, elastic modulus, fracture toughness, micro-hardness and thermal expansion coefficient (TEC) of glass-ceramics were investigated. The in vitro bioactivity and cytotoxicity tests were used to evaluate the bioactivity and biocompatibility of glass-ceramics. The sedimentation mechanism and growth process of apatites on sample surface were discussed. The results showed that the mainly crystalline phases of glass-ceramics were Ca(5)(PO4)3F (fluorapatite) and β-CaSiO(3). (β-wollastonite). m-ZrO(2) (monoclinic zirconia) declined the crystallization temperatures of glasses. t-ZrO(2) (tetragonal zirconia) increased the crystallization temperature of Ca(5)(PO4)(3)F and declined the crystallization temperature of β-CaSiO(3). t-ZrO(2) greatly increased the fracture toughness, bending strength and micro-hardness of glass-ceramics. The nanometer apatites were induced on the surface of glass-ceramic after soaking 28 days in SBF (simulated body fluid), indicating the glass-ceramic has good bioactivity. The in vitro cytotoxicity test demonstrated the glass-ceramic has no toxicity to cell.

  9. Disappearance of superconductivity in the solid solution between (Ca4Al2O6)(Fe2As2) and (Ca4Al2O6)(Fe2P2) superconductors.

    PubMed

    Shirage, Parasharam M; Kihou, Kunihiro; Lee, Chul-Ho; Takeshita, Nao; Eisaki, Hiroshi; Iyo, Akira

    2012-09-19

    The effect of alloying the two perovskite-type iron-based superconductors (Ca(4)Al(2)O(6))(Fe(2)As(2)) and (Ca(4)Al(2)O(6))(Fe(2)P(2)) was examined. While the two stoichiometric compounds possess relatively high T(c)'s of 28 and 17 K, respectively, their solid solutions of the form (Ca(4)Al(2)O(6))(Fe(2)(As(1-x)P(x))(2)) do not show superconductivity over a wide range from x = 0.50 to 0.95. The resultant phase diagram is thus completely different from those of other typical iron-based superconductors such as BaFe(2)(As,P)(2) and LaFe(As,P)O, in which superconductivity shows up when P is substituted for As in the non-superconducting "parent" compounds. Notably, the solid solutions in the non-superconducting range exhibit resistivity anomalies at temperatures of 50-100 K. The behavior is reminiscent of the resistivity kink commonly observed in various non-superconducting parent compounds that signals the onset of antiferromagnetic/orthorhombic long-range order. The similarity suggests that the suppression of the superconductivity in the present case also has a magnetic and/or structural origin.

  10. Neuropharmacology of Purinergic Receptors in Human Submucous Plexus: Involvement of P2X1, P2X2, P2X3 Channels, P2Y and A3 Metabotropic Receptors in Neurotransmission

    PubMed Central

    Liñán-Rico, A.; Wunderlich, JE.; Enneking, JT.; Tso, DR.; Grants, I.; Williams, KC.; Otey, A.; Michel, K.; Schemann, M.; Needleman, B.; Harzman, A.; Christofi, FL.

    2015-01-01

    Rationale The role of purinergic signaling in the human ENS is not well understood. We sought to further characterize the neuropharmacology of purinergic receptors in human ENS and test the hypothesis that endogenous purines are critical regulators of neurotransmission. Experimental Approach LSCM-Fluo-4-(Ca2+)-imaging of postsynaptic Ca2+ transients (PSCaTs) was used as a reporter of neural activity. Synaptic transmission was evoked by fiber tract electrical stimulation in human SMP surgical preparations. Pharmacological analysis of purinergic signaling was done in 1,556 neurons from 234 separate ganglia 107 patients; immunochemical labeling for P2XRs of neurons in ganglia from 19 patients. Real-time MSORT (Di-8-ANEPPS) imaging was used to test effects of adenosine on fast excitatory synaptic potentials (fEPSPs). Results Synaptic transmission is sensitive to pharmacological manipulations that alter accumulation of extracellular purines. Apyrase blocks PSCaTs in a majority of neurons. An ecto-NTPDase-inhibitor 6-N,N-diethyl-D-β,γ-dibromomethyleneATP or adenosine deaminase augments PSCaTs. Blockade of reuptake/deamination of eADO inhibits PSCaTs. Adenosine inhibits fEPSPs and PSCaTs (IC50=25μM), sensitive to MRS1220-antagonism (A3AR). A P2Y agonist ADPβS inhibits PSCaTs (IC50=111nM) in neurons without stimulatory ADPβS responses (EC50=960nM). ATP or a P2X1,2,2/3 (α,β-MeATP) agonist evokes fast, slow, biphasic Ca2+ transients or Ca2+ oscillations (EC50=400μM). PSCaTs are sensitive to P2X1 antagonist NF279. Low (20nM) or high (5μM) concentrations of P2X antagonist TNP-ATP block PSCaTs in different neurons; proportions of neurons with P2XR-ir follow the order P2X2>P2X1≫P2X3; P2X1+ P2X2 and P2X3+P2X2 are co-localized. RT-PCR identified mRNA-transcripts for P2X1-7,P2Y1,2,12-14R. Responsive neurons were also identified by HuC/D-ir. Conclusions Purines are critical regulators of neurotransmission in the human enteric nervous system. Purinergic signaling involves

  11. Accurate ab initio potential energy surface, thermochemistry, and dynamics of the Cl(2P, 2P3/2) + CH4 → HCl + CH3 and H + CH3Cl reactions

    NASA Astrophysics Data System (ADS)

    Czakó, Gábor; Bowman, Joel M.

    2012-01-01

    We report a high-quality, ab initio, full-dimensional global potential energy surface (PES) for the Cl(2P, 2P3/2) + CH4 reaction, which describes both the abstraction (HCl + CH3) and substitution (H + CH3Cl) channels. The analytical PES is a least-squares fit, using a basis of permutationally invariant polynomials, to roughly 16 000 ab initio energy points, obtained by an efficient composite method, including counterpoise and spin-orbit corrections for the entrance channel. This composite method is shown to provide accuracy almost equal to all-electron CCSD(T)/aug-cc-pCVQZ results, but at much lower computational cost. Details of the PES, as well as additional high-level benchmark characterization of structures and energetics are reported. The PES has classical barrier heights of 2650 and 15 060 cm-1 (relative to Cl(2P3/2) + CH4(eq)), respectively, for the abstraction and substitution reactions, in good agreement with the corresponding new computed benchmark values, 2670 and 14 720 cm-1. The PES also accurately describes the potential wells in the entrance and exit channels for the abstraction reaction. Quasiclassical trajectory calculations using the PES show that (a) the inclusion of the spin-orbit corrections in the PES decreases the cross sections by a factor of 1.5-2.5 at low collision energies (Ecoll); (b) at Ecoll ≈ 13 000 cm-1 the substitution channel opens and the H/HCl ratio increases rapidly with Ecoll; (c) the maximum impact parameter (bmax) for the abstraction reaction is ˜6 bohr; whereas bmax is only ˜2 bohr for the substitution; (d) the HCl and CH3 products are mainly in the vibrational ground state even at very high Ecoll; and (e) the HCl rotational distributions are cold, in excellent agreement with experiment at Ecoll = 1280 cm-1.

  12. Role of G-protein beta gamma subunits in the augmentation of P2Y2 (P2U)receptor-stimulated responses by neuropeptide Y Y1 Gi/o-coupled receptors.

    PubMed Central

    Selbie, L A; King, N V; Dickenson, J M; Hill, S J

    1997-01-01

    Neuropeptide Y (NPY) significantly potentiates the constrictor actions of noradrenaline and ATP on blood vessels via a pertussis toxin (PTX)-sensitive mechanism involving Gi/o (alpha beta gamma) protein subunits (Gi/o, GTP-binding proteins sensitive to PTX). In Chinese hamster ovary K1 (CHO K1) cells expressing specific receptors for these neurotransmitters, stimulation of Gi/o protein-coupled receptors for NPY and other neurotransmitters can augment the Gq/11-coupled (Gq/11, GTP-binding proteins insensitive to PTX) alpha 1B adrenoceptor- or ATP receptor-induced arachidonic acid (AA) release and inositol phosphate (IP) production (early events which may precede vasoconstriction). In this study, we have assessed the role of G beta gamma subunits in the synergistic interaction between Gi/o- (NPY Y1, 5-hydroxytryptamine 5-HT1B, adenosine A1) and Gq/11- [ATP P2Y2 (P2U)]-coupled receptors on AA release by using the specific abilities of regions of the beta-adrenergic receptor kinase (beta ARK1 residues 495-689) and the transducin alpha subunit to associate with G-protein beta gamma subunit dimers and to act as G beta gamma subunit scavengers. Transient expression of beta ARK1(495-689) in CHO K1 cells heterologously expressing NPY Y1 receptors had no significant effect on the PTX-insensitive ability of ATP to stimulate AA release. Stimulation of NPY Y1 receptors (as well as the endogenous 5-hydroxytryptamine 5-HT1B receptor and the transiently expressed human adenosine A1 receptor) resulted in a PTX-sensitive augmentation of ATP-stimulated AA release, which was inhibited by expression of both G beta gamma subunit scavengers. Expression of beta ARK1(495-689) similarly inhibited NPY Y1 receptor augmentation of ATP-stimulated IP production (a measure of phospholipase C activity), a step thought to precede the NPY Y1 receptor-augmented protein kinase C-dependent AA release previously observed in these cells. These experiments demonstrate that G beta gamma subunits, as

  13. Fabrication and evaluation of osteoblastic differentiation of human mesenchymal stem cells on novel CaO-SiO2-P2O5-B2O3 glass-ceramics.

    PubMed

    Lee, Jae Hyup; Seo, Jun-Hyuk; Lee, Kyung Mee; Ryu, Hyun-Seung; Baek, Hae-Ri

    2013-07-01

    Apatite-wollastonite glass-ceramics have high mechanical strength, and CaO-SiO2 -B2 O3 glass-ceramics showed excellent bioactivity and high biodegradability. A new type of CaO-SiO2 -P2 O5 -B2 O3 system of bioactive glass-ceramics (BGS-7) was fabricated, and the effect and usefulness was evaluated via bioactivity using simulated body fluid and human mesenchymal stem cells (hMSCs). The purpose of this study was to compare BGS-7 and hydroxyapatite (HA) using hMSCs in order to evaluate the bioactivity of BGS-7 and its possibility as a bone graft extender. Alkaline phosphatase (ALP) staining, ALP activity, cell proliferation 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, Alizarin Red-S (AR-S) staining, calcium levels, the mRNA expression of ALP, osteocalcin, osteopontin, and runt-related transcription factor 2 (runx-2) using reverse-transcription polymerase chain reaction (RT-PCR) and the protein expression of osteocalcin and runx-2 using Western blot were measured by transplanting hMSC onto a tissue culture plate, HA, and BGS-7. The ALP staining and AR-S staining of BGS-7 was greater than that of HA and control. The ALP value of BGS-7 was significantly higher than that of HA and control. The MTS results showed that BGS-7 had a higher value than the groups transplanted onto HA and control on day 15. The calcium level was higher than the control in both HA and BGS-7, and was especially high in BGS-7. There were more mineral products on BGS-7 than on the HA when analyzed by scanning electron microscopy. The mRNA expression of ALP, osteopontin, osteocalcin, and runx-2 were higher on BGS-7 than on HA and the control when analyzed by RT-PCR. The relative gene expression of osteopontin and runx-2 were found to be higher on BGS-7 than on HA and the control by Western blot. Accordingly, it is predicted that BGS-7 would have high biocompatibility and good osteoconductivity, and presents a possibility as a new

  14. Reactivity of the anionic diphosphorus complex [Mo2Cp2(μ-PCy2)(μ-κ(2):κ(2)-P2)(CO)2]- toward phosphorus- and transition metal-based electrophiles.

    PubMed

    Alvarez, M Angeles; García, M Esther; García-Vivó, Daniel; Lozano, Raquel; Ramos, Alberto; Ruiz, Miguel A

    2013-08-05

    The reactions of the Li(+) salt of the title anion with chlorophosphines PR2Cl (R = Cy, Ph, (t)Bu) led in all cases to products of formula [Mo2Cp2(μ-PCy2)(μ-κ(2)(P,P)':κ(2)(P,P″)-P2PR2)(CO)2], with the PR2 group inserted in one of the Mo-P(basal) bonds of the anion to give novel tridentate phosphinodiphosphenyl ligands, as confirmed by the solid-state structure of the PCy2 compound. When R was the bulky (t)Bu group, this product was in equilibrium with an isomer of formula [Mo2Cp2(μ-PCy2)(μ-κ(2)(P,P)':κ(2)(P,P')-P2P(t)Bu2)(CO)2], in which the diphosphorus ligand of the anion binds the P(t)Bu2 group through the lone pair of electrons at the basal P atom in an "end-on" fashion (computed P-P-P(t)Bu2 = 114.7°); the latter isomer was more stable than the former, according to the NMR data and density functional theory (DFT) calculations. The title anion reacted with halide complexes of the type [MXLn] (MLn = FeCp(CO)2, MoCp(CO)3, ZrCpCl, Mn(CO)5, Re(CO)5) to give compounds of formula [Mo2MCp2(μ-PCy2)(μ-κ(2):κ(2):κ(1)-P2)(CO)2Ln] incorporating the organometallic fragment MLn also in an "end-on" position at the basal P atom of the anion, as confirmed by the solid-state structure of the Fe compound (P-P = 2.089(2) Å; P-P-Fe = 124.6(1)°). All these complexes, except the Zr compound, underwent a fluxional process in solution involving a swing of the P2 ligand around the Mo-Mo axis with concomitant exchange of the MLn fragment between the P atoms of the diphosphorus ligand, as revealed by variable-temperature NMR experiments. Thermal decarbonylation of the Mn and Re compounds gave hexanuclear derivatives of formula [Mo4M2Cp4(μ-PCy2)2(μ4-κ(1):κ(2):κ(2):κ(1)-P2)2(CO)12] (M = Mn, Re) as a mixture of two isomers derived from the different assembly of the asymmetric Mo2P2 subunits, as confirmed through X-ray analyses of both compounds. Each of the P2 ligands in these two complexes bind two Mo and two M atoms (M = Mn, Re), with the latter defining central P4M

  15. Double helicenes

    NASA Astrophysics Data System (ADS)

    Bachrach, Steven M.

    2016-12-01

    The even double helicenes with 4-12 phenyl groups in each helix were examined at B3LYP-D3/6-311G(d). The double helicenes with 4-10 phenyl rings are less than twice as strained as their component helicenes; the strain results from twisting about the shared naphthyl moiety, with accompanying loss of aromaticity. These compounds should be reasonable synthetic targets, and computed NMR shifts are provided to aid in their characterization.

  16. Photoelectrochemical cells based on ternary compounds CuIn{sub 2n+1}Se{sub 3n+2} (n = 3-6)

    SciTech Connect

    Rud, V. Yu. Rud, Yu. V.; Bodnar, I. V.; Gorbachev, D. V.; Ushakova, T. N.

    2009-03-15

    Single crystals of ternary CuIn{sub 2n+1}Se{sub 3n+2} semiconductors with the composition index n = 3, 5, 6 were grown for the first time using the direct crystallization method. It was shown that these crystals have hexagonal symmetry and close unit cell parameters. Photoelectrochemical cells based on CuIn{sub 2n+1}Se{sub 3n+2} and In{sub 2}Se{sub 3} single crystals were fabricated. Their photosensitivity spectra were measured for the first time, which were used to determine the nature of interband transitions and the band gap. The weak dependence of the parameters of the band's spectrum and unit cell of these semiconductors at n {>=} 2 was attributed to the features of the interatomic interaction in such phases. It was concluded that new CuIn{sub 2n+1}Se{sub 3n+2} semiconductors can be used in broadband photoconverters of optical radiations.

  17. [Double responses].

    PubMed

    Motté, G; Dinanian, S; Sebag, C; Drieu, L; Slama, M

    1995-12-01

    Double response is a rare electrocardiographic phenomenon requiring two atrioventricular conduction pathways with very different electrophysiological properties. Double ventricular responses are the usual manifestation: an atrial depolarisation (spontaneous or provoked, anticipated or not) is followed by a first ventricular response dependent on an accessory pathway or a rapid nodal pathway and then a second response resulting from sufficiently delayed transmission through a nodal pathway for the ventricles to have recovered their excitability when the second wave of activation reaches them. A simple curiosity when isolated and occurring under unusual conditions, particularly during electrophysiological investigation of the Wolff-Parkinson-White syndrome, the double response may initiate symptomatic non-reentrant junctional tachycardia when associated with nodal duality and repeating from atria in sinus rhythm. The functional incapacity and resistance to antiarrhythmic therapy may require referral for ablation of the slow pathway.

  18. Double Crater

    NASA Image and Video Library

    2012-03-23

    A double crater, called a crater doublet, is seen in the bottom right part of this image from NASA Dawn spacecraft of asteroid Vesta. This crater doublet was likely formed by the simultaneous impact of two fragments of a split projectile.

  19. Tetranuclear phosphide- and phosphinidene-bridged derivatives of the diphosphenyl complex [Mo2Cp2(μ-PCy2)(μ-κ(2):κ(2)-P2Me)(CO)2].

    PubMed

    Alvarez, M Angeles; García, M Esther; Lozano, Raquel; Ramos, Alberto; Ruiz, Miguel A

    2015-03-02

    Reaction of the title complex with excess [Fe2(CO)9] at room temperature gave the tetranuclear derivative [Fe2Mo2Cp2(μ4-P)(μ-PCy2)(μ3-PMe)(CO)9], following from formal insertion of an Fe(CO)3 fragment in the P-P bond of the diphosphenyl ligand with formation of a new heterometallic bond (Mo-Fe = 2.935 (1) Å), and coordination of an Fe(CO)4 fragment through the lone electron pair of the resulting phosphide ligand (P-Fe = 2.359(2) Å). Reactions of the title complex with excess of the tetrahydrofuran (THF) adducts [MLn(THF)] (MLn = MnCp'(CO)2, W(CO)5) led instead to tetranuclear diphosphenyl-bridged complexes [M2Mo2Cp2(μ-PCy2)(μ-κ(2):κ(1):κ(1):κ(1)-P2Me)(CO)2L2n] displaying a Mo-Mo double bond (Mo-Mo = 2.760(2) Å when M = W), along with the phosphide- and phosphinidene-bridged complex [Mo2W2Cp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)10], with the latter displaying a Mo-Mo triple bond (Mo-Mo = 2.5542(4) Å) and a trigonal planar phosphide ligand. Reaction of the title complex with excess [Mo(CO)4(THF)2] also resulted in facile P-P bond cleavage of the diphosphenyl ligand to give [Mo4Cp2(μ4-P)(μ-PCy2)(μ3-PMe)(CO)9], a cluster built on a Mo3 triangular core bridged by phosphinidene and phosphide ligands, with the latter further coordinated to an exocyclic Mo(CO)5 fragment. The related Mo2W2 complex [Mo2W2Cp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)9] could be rationally synthesized upon reaction of the trinuclear cluster [Mo2WCp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)6] with the adduct [W(CO)5(THF)]. The title complex reacted photochemically with [M2(CO)10] (M = Mn, Re) to give the 66-electron tetranuclear derivatives [M2Mo2Cp2(μ4-P)(μ-PCy2)(μ3-PMe)(CO)9], after formation of a new Mo-M bond (Mo-Mn = 2.9988(7) Å, Mo-Re = 3.1003(4) Å) and cleavage of the diphosphenyl P-P bond. In contrast, its room-temperature reaction with [Co2(CO)8] gave the 64-electron square-planar cluster [Co2Mo2Cp2(μ4-P)(μ-PCy2)(μ4-PMe)(μ-CO)(CO)6] resulting from formation of two new Mo-Co bonds (Mo-Co = 2

  20. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (Editor); Moorehead, Tauna W. (Editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  1. Double screening

    SciTech Connect

    Gratia, Pierre; Hu, Wayne; Joyce, Austin; Ribeiro, Raquel H.

    2016-06-15

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  2. Double inflation

    SciTech Connect

    Silk, J.; Turner, M.S.

    1986-04-01

    The Zel'dovich spectrum of adiabatic density perturbations is a generic prediction of inflation. There is increasing evidence that when the spectrum is normalized by observational data on small scales, there is not enough power on large scales to account for the observed large-scale structure in the Universe. Decoupling the spectrum on large and small scales could solve this problem. As a means of decoupling the large and small scales we propose double inflation (i.e., two episodes of inflation). In this scenario the spectrum on large scales is determined by the first episode of inflation and those on small scales by a second episode of inflation. We present three models for such a scenario. By nearly saturating the large angular-scale cosmic microwave anisotropy bound, we can easily account for the observed large-scale structure. We take the perturbations on small scales to be very large, deltarho/rho approx. = 0.1 to 0.01, which results in the production of primordial black holes (PBHs), early formation of structure, reionization of the Universe, and a rich array of astrophysical events. The ..cap omega..-problem is also addressed by our scenario. Allowing the density perturbations produced by the second episode of inflation to be large also lessens the fine-tuning required in the scalar potential and makes reheating much easier. We briefly speculate on the possibility that the second episode of inflation proceeds through the nucleation of bubbles, which today manifest themselves as empty bubbles whose surfaces are covered with galaxies. 37 refs., 1 fig.

  3. Seeing Double

    NASA Astrophysics Data System (ADS)

    Pesic, Peter

    2003-10-01

    The separateness and connection of individuals is perhaps the central question of human life: What, exactly, is my individuality? To what degree is it unique? To what degree can it be shared, and how? To the many philosophical and literary speculations about these topics over time, modern science has added the curious twist of quantum theory, which requires that the elementary particles of which everything consists have no individuality at all. All aspects of chemistry depend on this lack of individuality, as do many branches of physics. From where, then, does our individuality come? In Seeing Double, Peter Pesic invites readers to explore this intriguing set of questions. He draws on literary and historical examples that open the mind (from Homer to Martin Guerre to Kafka), philosophical analyses that have helped to make our thinking and speech more precise, and scientific work that has enabled us to characterize the phenomena of nature. Though he does not try to be all-inclusive, Pesic presents a broad range of ideas, building toward a specific point of view: that the crux of modern quantum theory is its clash with our ordinary concept of individuality. This represents a departure from the usual understanding of quantum theory. Pesic argues that what is bizarre about quantum theory becomes more intelligible as we reconsider what we mean by individuality and identity in ordinary experience. In turn, quantum identity opens a new perspective on us. Peter Pesic is a Tutor and Musician-in-Residence at St. John's College, Santa Fe, New Mexico. He has a Ph.D. in physics from Stanford University.

  4. Double Your Major, Double Your Return?

    ERIC Educational Resources Information Center

    Del Rossi, Alison F.; Hersch, Joni

    2008-01-01

    We use the 2003 National Survey of College Graduates to provide the first estimates of the effect on earnings of having a double major. Overall, double majoring increases earnings by 2.3% relative to having a single major among college graduates without graduate degrees. Most of the gains from having a double major come from choosing fields across…

  5. Adsorption of the cis-[Pt(NH3)2(P2O7)](2-) (phosphaplatin) on hydroxyapatite nanocrystals as a smart way to selectively release activated cis-[Pt(NH3)2Cl2] (cisplatin) in tumor tissues.

    PubMed

    Benedetti, Michele; De Castro, Federica; Romano, Alessandro; Migoni, Danilo; Piccinni, Barbara; Verri, Tiziano; Lelli, Marco; Roveri, Norberto; Fanizzi, Francesco P

    2016-04-01

    The relevant adsorption of cis-[Pt(NH3)2(P2O7)](2-) (phosphaplatin) on hydroxyapatite nanocrystals (nHAP) was observed and studied in water suspension. Phosphaplatin cytotoxicity, which is very low for HeLa, MCF-7 and HS-5 cell lines could be enhanced, reaching that of cisplatin, by interaction with solid nHAP. This effect stems from nHAP ability to catalyze the phosphaplatin hydrolysis, producing the same hydrolytic species responsible for cisplatin antitumor activity.

  6. Structures, energies, and spin-spin coupling constants of fluoro-substituted 1,3-diborata-2,4-diphosphoniocyclobutanes: four-member B-P-B-P rings B2P2F(n)H(8-n) with n = 0, 1, 2, 4.

    PubMed

    Del Bene, Janet E; Alkorta, Ibon; Elguero, José

    2011-05-05

    An ab initio study has been carried out to determine the structures, relative stabilities, and spin-spin coupling constants of a set of 15 fluoro-substituted 1,3-diborata-2,4-diphosphoniocyclobutanes B(2)P(2)F(n)H(8-n), for n = 0, 1, 2, 4, with four-member B-P-B-P rings. Except for B(2)P(2)F(4)H(4) with four fluorines bonded to two borons, these rings are puckered in a butterfly conformation. For a fixed number of fluorines, the isomers with B-F bonds are significantly more stable than those with P-F bonds. As the number of fluorines increases, the energy difference between the most stable isomer and the other isomers increases. Transition structures which interconvert axial and equatorial positions present relatively small inversion barriers. Coupling constants involving (31)P, namely, (1)J(B-P), (1)J(P-F), (2)J(P-P), (2)J(P-F), and (3)J(P-F) are large and are capable of providing structural information. They are sensitive to the number of fluorines present and can discriminate between axial, equatorial, and geminal B-F and P-F bonds, although not all do this to the same extent. (1)J(B-P) and (2)J(P-P) are similar in equilibrium and transition structures. Although transition structures no longer discriminate between axial and equatorial bonds, (1)J(P-F) and (3)J(P-F) remain sensitive to the number of fluorine atoms present.

  7. A double-double/double-single computation package

    SciTech Connect

    Bailey, David H.

    2004-12-01

    The DDFUNIDSFUN software permits a new or existing Fortran-90 program to utilize double-double precision (approx. 31 digits) or double-single precision (approx. 14 digits) arithmetic. Double-double precision is required by a rapidly expandirtg body of scientific computations in physics and mathematics, for which the conventional 64-bit IEEE computer arithmetic (about 16 decimal digit accuracy) is not sufficient. Double-single precision permits users of systems that do not have hardware 64-bit IEEE arithmetic (such as some game systems) to perform arithmetic at a precision nearly as high as that of systems that do. Both packages run significantly faster Than using multiple precision or arbitrary precision software for this purpose. The package includes an extensive set of low-level routines to perform high-precision arithmetic, including routines to calculate various algebraic and transcendental functions, such as square roots, sin, ccc, exp, log and others. In addition, the package includes high-level translation facilities, so that Fortran programs can utilize these facilities by making only a few changes to conventional Fortran programs. In most cases, the only changes that are required are to change the type statements of variables that one wishes to be treated as multiple precision, plus a few other minor changes. The DDFUN package is similar in functionality to the double-double part of the GD package, which was previously written at LBNL. However, the DDFUN package is written exclusively in Fortran-90, thus avoidIng difficulties that some users experience when using GD, which includes both Fortran-90 and C++ code.

  8. [A double gallbladder].

    PubMed

    Mink van der Molen, A B; Salu, M K

    1991-04-06

    A 59-year-old woman is described with symptomatic cholelithiasis. A double gallbladder was incidentally found during abdominal surgery. The literature on a double gallbladder is reviewed with respect to incidence, anatomy, diagnosis and therapy.

  9. Chromosome doubling method

    DOEpatents

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  10. The double identity of linguistic doubling.

    PubMed

    Berent, Iris; Bat-El, Outi; Brentari, Diane; Dupuis, Amanda; Vaknin-Nusbaum, Vered

    2016-11-29

    Does knowledge of language consist of abstract principles, or is it fully embodied in the sensorimotor system? To address this question, we investigate the double identity of doubling (e.g., slaflaf, or generally, XX; where X stands for a phonological constituent). Across languages, doubling is known to elicit conflicting preferences at different levels of linguistic analysis (phonology vs. morphology). Here, we show that these preferences are active in the brains of individual speakers, and they are demonstrably distinct from sensorimotor pressures. We first demonstrate that doubling in novel English words elicits divergent percepts: Viewed as meaningless (phonological) forms, doubling is disliked (e.g., slaflaf < slafmak), but once doubling in form is systematically linked to meaning (e.g., slaf = ball, slaflaf = balls), the doubling aversion shifts into a reliable (morphological) preference. We next show that sign-naive speakers spontaneously project these principles to novel signs in American Sign Language, and their capacity to do so depends on the structure of their spoken language (English vs. Hebrew). These results demonstrate that linguistic preferences doubly dissociate from sensorimotor demands: A single stimulus can elicit diverse percepts, yet these percepts are invariant across stimulus modality--for speech and signs. These conclusions are in line with the possibility that some linguistic principles are abstract, and they apply broadly across language modality.

  11. Structures, energies, and spin-spin coupling constants of methyl-substituted 1,3-diborata-2,4-diphosphoniocyclobutanes: four-member B-P-B-P rings B2P2(CH3)(n)H(8-n), with n = 0, 1, 2, 4.

    PubMed

    Del Bene, Janet E; Alkorta, Ibon; Elguero, José

    2011-09-29

    An ab initio study has been carried out to determine the structures, relative stabilities, and spin-spin coupling constants of a set of 17 methyl-substituted 1,3-diborata-2,4-diphosphoniocyclobutanes B(2)P(2)(CH(3))(n)H(8-n), for n = 0, 1, 2, 4, with four-member B-P-B-P rings. The B-P-B-P rings are puckered in a butterfly conformation, in agreement with experimental data for related molecules. Isomers with the CH(3) group bonded to P are more stable than those with CH(3) bonded to B. If there is only one methyl group or if two methyl groups are bonded to two different P or B atoms, isomers with equatorial bonds are more stable than those with axial bonds. However, when two methyl groups are present, the gem isomers are the most stable for molecules B(2)P(2)(CH(3))(2)H(6) with P-C and B-C bonds, respectively. Transition structures present barriers to the interconversion of two equilibrium structures or to the interchange of axial and equatorial positions in the same isomer. These barriers are very low for the isomer with two methyl groups bonded to B in axial positions for the isomer with four axial bonds and for the isomer with geminal B-C bonds at both B atoms. Coupling constants (1)J(B-P), (1)J(P-C), (1)J(B-C), (2)J(P-P), and (3)J(P-C) are capable of providing structural information. They are sensitive to the number of methyl groups present and can discriminate between axial, equatorial, and geminal bonds, although not all do this to the same extent. The one-bond coupling constants (1)J(B-P), (1)J(P-C), and (1)J(B-C) are similar in equilibrium and transition structures, but (3)J(P-C) and (2)J(P-P) are not. These coupling constants and those of the corresponding fluoro-derivatives of the 1,3-diborata-2,4-diphosphoniocyclobutanes demonstrate the great sensitivity of phosphorus coupling to structural and electronic effects.

  12. Effect of temperature of Li2O-Al2O3-TiO2-P2O5 solid-state electrolyte coating process on the performance of LiNi0.5Mn1.5O4 cathode materials

    NASA Astrophysics Data System (ADS)

    Deng, Yu-Feng; Zhao, Shi-Xi; Xu, Ya-Hui; Nan, Ce-Wen

    2015-11-01

    Electrochemical performance of spinel LiNi0.5Mn1.5O4 (LNMO) at elevated temperature is improved by solid-state electrolyte Li2O-Al2O3-TiO2-P2O5 (LATP) coating. Crystallinity and thickness of coatings are controlled by adjusting the coating process at two different temperatures (550 and 650 °C). 2.0 wt.% LATP-modified LNMO cathode materials obtained at 650 °C exhibits remarkably promoted electrochemical performance compared to that of the pristine one in terms of cycling and rate ability at 55 °C. The enhanced performance of the surface-modified samples can be accounted for the suppressed side reactions between the cathode materials and electrolyte solution. What is more important is that LATP cannot only protect the active materials from electrolyte solution but also improve Li+ mobility. The higher crystallinity of glass-ceramic LATP coating layer with thinner thickness implies more unobstructed, stable and shorter diffusion path of Li+ transport. It is found that the coating process is in favor of the disordered to ordered phase transition, implying that the heating process of coating plays a role of anneal as well.

  13. Double-Bounce Switching

    DTIC Science & Technology

    1983-06-01

    module. Adjustments provided to investigate double- bounce switching are noted. limitation is at a higher level and occurs in the conventionally...To be presented at the 4th IEEE PUlsed Power Conference, June 6-8, 1983, Albuquerque, NM. DOUBLE- BOUNCE SWITCHING* George B. Frazier and Steven R...Ashby Physics International Company 2700 Merced Street San Leandro, California 94577 Abstract Double- bounce switching is a technique for

  14. Observing Double Stars

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  15. The double life of double effect.

    PubMed

    McIntyre, Alison

    2004-01-01

    The U.S. Supreme Court's majority opinion in Vacco v. Quill assumes that the principle of double effect explains the permissibility of hastening death in the context of ordinary palliative care and in extraordinary cases in which painkilling drugs have failed to relieve especially intractable suffering and terminal sedation has been adopted as a last resort. The traditional doctrine of double effect, understood as providing a prohibition on instrumental harming as opposed to incidental harming or harming as a side effect, must be distinguished from other ways in which the claim that a result is not intended might be offered as part of a justification for it. Although double effect might appropriately be invoked as a constraint on ordinary palliative care, it is not clear that it can be coherently extended to justify such practices as terminal sedation. A better approach would reconsider double effect's traditional prohibition on hastening death as a means to relieve suffering in the context of acute palliative care.

  16. Double metalization for VLSI

    NASA Technical Reports Server (NTRS)

    Trotter, J. D.; Wade, T. E.

    1980-01-01

    Postsintering process increases yield of double-layer metal conductors to almost 100 percent. When wafers containing double-metalized chips are sintered, metal layers react with oxide film remaining in insulation layer holes, breaking it up so that it no longer impedes electric current. Cooling also mechanically disrupts oxide film.

  17. Multidimensional period doubling structures.

    PubMed

    Lee, Jeong Yup; Flom, Dvir; Ben-Abraham, Shelomo I

    2016-05-01

    This paper develops the formalism necessary to generalize the period doubling sequence to arbitrary dimension by straightforward extension of the substitution and recursion rules. It is shown that the period doubling structures of arbitrary dimension are pure point diffractive. The symmetries of the structures are pointed out.

  18. Emerging double helical nanostructures

    NASA Astrophysics Data System (ADS)

    Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Wei, Fei

    2014-07-01

    As one of the most important and land-mark structures found in nature, a double helix consists of two congruent single helices with the same axis or a translation along the axis. This double helical structure renders the deoxyribonucleic acid (DNA) the crucial biomolecule in evolution and metabolism. DNA-like double helical nanostructures are probably the most fantastic yet ubiquitous geometry at the nanoscale level, which are expected to exhibit exceptional and even rather different properties due to the unique organization of the two single helices and their synergistic effect. The organization of nanomaterials into double helical structures is an emerging hot topic for nanomaterials science due to their promising exceptional unique properties and applications. This review focuses on the state-of-the-art research progress for the fabrication of double-helical nanostructures based on `bottom-up' and `top-down' strategies. The relevant nanoscale, mesoscale, and macroscopic scale fabrication methods, as well as the properties of the double helical nanostructures are included. Critical perspectives are devoted to the synthesis principles and potential applications in this emerging research area. A multidisciplinary approach from the scope of nanoscience, physics, chemistry, materials, engineering, and other application areas is still required to the well-controlled and large-scale synthesis, mechanism, property, and application exploration of double helical nanostructures.

  19. Emerging double helical nanostructures.

    PubMed

    Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Wei, Fei

    2014-08-21

    As one of the most important and land-mark structures found in nature, a double helix consists of two congruent single helices with the same axis or a translation along the axis. This double helical structure renders the deoxyribonucleic acid (DNA) the crucial biomolecule in evolution and metabolism. DNA-like double helical nanostructures are probably the most fantastic yet ubiquitous geometry at the nanoscale level, which are expected to exhibit exceptional and even rather different properties due to the unique organization of the two single helices and their synergistic effect. The organization of nanomaterials into double helical structures is an emerging hot topic for nanomaterials science due to their promising exceptional unique properties and applications. This review focuses on the state-of-the-art research progress for the fabrication of double-helical nanostructures based on 'bottom-up' and 'top-down' strategies. The relevant nanoscale, mesoscale, and macroscopic scale fabrication methods, as well as the properties of the double helical nanostructures are included. Critical perspectives are devoted to the synthesis principles and potential applications in this emerging research area. A multidisciplinary approach from the scope of nanoscience, physics, chemistry, materials, engineering, and other application areas is still required to the well-controlled and large-scale synthesis, mechanism, property, and application exploration of double helical nanostructures.

  20. Topological Quantum Double

    NASA Astrophysics Data System (ADS)

    Bonneau, Philippe

    Following a preceding paper showing how the introduction of a t.v.s. topology on quantum groups led to a remarkable unification and rigidification of the different definitions, we adapt here, in the same way, the definition of quantum double. This topological double is dualizable and reflexive (even for infinite dimensional algebras). In a simple case we show, considering the double as the "zero class" of an extension theory, the uniqueness of the double structure as a quasi-Hopf algebra. A la suite d'un précédent article montrant comment l'introduction d'une topologie d'e.v.t. sur les groupes quantiques permet une unification et une rigidification remarquables des différentes définitions, on adapte ici de la même manière la définition du double quantique. Ce double topologique est alors dualisable et reflexif (même pour des algèbres de dimension infinie). Dans un cas simple on montre, en considérant le double comme la "classe zéro" d'une théorie d'extensions, l'unicité de cette structure comme algèbre quasi-Hopf.

  1. Double Outlet Right Ventricle

    MedlinePlus

    ... ency/article/007328.htm Double outlet right ventricle Texas Adult Congenital Heart Center (TACH) www.bcm.edu/ ... comments. Terms of Use and Privacy Policy © Copyright Texas Heart Institute All rights reserved.

  2. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  3. [Double scleral covering evisceration].

    PubMed

    Sanz López, A; Sales Sanz, M

    2003-05-01

    To describe a surgical technique for evisceration that allows the use of large size implants, reducing risk of exposure. We analize the results of 22 eviscerations with Medpor implants with double scleral covering. We managed to use implants of 20 and 22 mm, sometimes in very small anophthalmic cavities, without complications. Double scleral covering evisceration is a surgical technique that allows the use of large size implants, reducing the risk of exposure.

  4. Electron excitation cross sections for the 2s^2 2p ^2p^o-2s2p^2 ^4p and 2s2p^2 ^2D transitions in O^3+

    NASA Technical Reports Server (NTRS)

    Smith, S. J.; Lozano, J. A.; Tayal, S. S.; Chutjian, A.

    2003-01-01

    Comparison is made with results of new calculations in a 25-state R-matrix theory and with results in a previous eight-state R-matrix calculation. The presence of rich resonance structure is confirmed in both experiment and theory.

  5. Revisting the Double Helix

    SciTech Connect

    Ha, Taekjip

    2010-12-08

    Properties of DNA double helix have been studied for over 60 years. Yet as more sensitive tools become available, fundamental assumptions in our understanding of these properties are being challenged. One such question is over the flexibility of DNA. Looping or bending of DNA on short length scales is essential for many cellular processes but it is highly controversial exactly how flexible the DNA is. Using a new, single-molecule based method, we found that DNA of lengths as short as 50 base pairs can form a circle more than 108 times faster than theoretical predictions. Another question concerns the physical principles governing the reversible, helix-coil transitions of DNA between the double helix and single strands. Using porous nanocontainers, we found that the rate of double helix formation shows an abrupt 100 fold change depending on whether there are 7 or more contiguous base pairs or not.

  6. Double checking: a second look.

    PubMed

    Hewitt, Tanya; Chreim, Samia; Forster, Alan

    2016-04-01

    Double checking is a standard practice in many areas of health care, notwithstanding the lack of evidence supporting its efficacy. We ask in this study: 'How do front line practitioners conceptualize double checking? What are the weaknesses of double checking? What alternate views of double checking could render it a more robust process?' This is part of a larger qualitative study based on 85 semi-structured interviews of health care practitioners in general internal medicine and obstetrics and neonatology; thematic analysis of the transcribed interviews was undertaken. Inductive and deductive themes are reported. Weaknesses in the double checking process include inconsistent conceptualization of double checking, double (or more) checking as a costly and time-consuming procedure, double checking trusted as an accepted and stand-alone process, and double checking as preventing reporting of near misses. Alternate views of double checking that would render it a more robust process include recognizing that double checking requires training and a dedicated environment, Introducing automated double checking, and expanding double checking beyond error detection. These results are linked with the concepts of collective efficiency thoroughness trade off (ETTO), an in-family approach, and resilience. Double checking deserves more questioning, as there are limitations to the process. Practitioners could view double checking through alternate lenses, and thus help strengthen this ubiquitous practice that is rarely challenged. © 2015 The Authors. Journal of Evaluation in Clinical Practice published by John Wiley & Sons, Ltd.

  7. Double checking: a second look

    PubMed Central

    Chreim, Samia; Forster, Alan

    2015-01-01

    Abstract Rationale, aims and objectives Double checking is a standard practice in many areas of health care, notwithstanding the lack of evidence supporting its efficacy. We ask in this study: ‘How do front line practitioners conceptualize double checking? What are the weaknesses of double checking? What alternate views of double checking could render it a more robust process?’ Method This is part of a larger qualitative study based on 85 semi‐structured interviews of health care practitioners in general internal medicine and obstetrics and neonatology; thematic analysis of the transcribed interviews was undertaken. Inductive and deductive themes are reported. Results Weaknesses in the double checking process include inconsistent conceptualization of double checking, double (or more) checking as a costly and time‐consuming procedure, double checking trusted as an accepted and stand‐alone process, and double checking as preventing reporting of near misses. Alternate views of double checking that would render it a more robust process include recognizing that double checking requires training and a dedicated environment, Introducing automated double checking, and expanding double checking beyond error detection. These results are linked with the concepts of collective efficiency thoroughness trade off (ETTO), an in‐family approach, and resilience. Conclusion(s) Double checking deserves more questioning, as there are limitations to the process. Practitioners could view double checking through alternate lenses, and thus help strengthen this ubiquitous practice that is rarely challenged. PMID:26568537

  8. Double-helix stellarator

    SciTech Connect

    Moroz, P.E.

    1997-09-01

    A new stellarator configuration, the Double-Helix Stellarator (DHS), is introduced. This novel configuration features a double-helix center post as the only helical element of the stellarator coil system. The DHS configuration has many unique characteristics. One of them is the extreme low plasma aspect ratio, A {approx} 1--1.2. Other advantages include a high enclosed volume, appreciable rotational transform, and a possibility of extreme-high-{beta} MHD equilibria. Moreover, the DHS features improved transport characteristics caused by the absence of the magnetic field ripple on the outboard of the torus. Compactness, simplicity and modularity of the coil system add to the DHS advantages for fusion applications.

  9. Double arch mirror study

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  10. Double Photoionization Near Threshold

    NASA Technical Reports Server (NTRS)

    Wehlitz, Ralf

    2007-01-01

    The threshold region of the double-photoionization cross section is of particular interest because both ejected electrons move slowly in the Coulomb field of the residual ion. Near threshold both electrons have time to interact with each other and with the residual ion. Also, different theoretical models compete to describe the double-photoionization cross section in the threshold region. We have investigated that cross section for lithium and beryllium and have analyzed our data with respect to the latest results in the Coulomb-dipole theory. We find that our data support the idea of a Coulomb-dipole interaction.

  11. Double Marking Revisited

    ERIC Educational Resources Information Center

    Brooks, Val

    2004-01-01

    In 2002, the Qualifications and Curriculum Authority (QCA) published the report of an independent panel of experts into maintaining standards at Advanced Level (A-Level). One of its recommendations was for: limited experimental double marking of scripts in subjects such as English to determine whether the strategy would significantly reduce errors…

  12. Double Helix Revisited.

    ERIC Educational Resources Information Center

    Glickstein, Neil M.

    1995-01-01

    Describes the use of James Watson's book, "The Double Helix," as a multidisciplinary way of introducing students to actual science; the scientific method; dilemmas encountered in the world of research; and the rich setting of personalities, politics, and history in post-World War II Europe. (MKR)

  13. Weathering the Double Whammy.

    ERIC Educational Resources Information Center

    Wellman, Jane V.

    2002-01-01

    Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the…

  14. Weathering the Double Whammy.

    ERIC Educational Resources Information Center

    Wellman, Jane V.

    2002-01-01

    Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the…

  15. Double Helix Revisited.

    ERIC Educational Resources Information Center

    Glickstein, Neil M.

    1995-01-01

    Describes the use of James Watson's book, "The Double Helix," as a multidisciplinary way of introducing students to actual science; the scientific method; dilemmas encountered in the world of research; and the rich setting of personalities, politics, and history in post-World War II Europe. (MKR)

  16. Teaching the Double Layer.

    ERIC Educational Resources Information Center

    Bockris, J. O'M.

    1983-01-01

    Suggests various methods for teaching the double layer in electrochemistry courses. Topics addressed include measuring change in absolute potential difference (PD) at interphase, conventional electrode potential scale, analyzing absolute PD, metal-metal and overlap electron PDs, accumulation of material at interphase, thermodynamics of electrified…

  17. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, D.R.

    1982-09-23

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  18. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, Dale R.

    1984-01-01

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  19. Design for Double Rainbow

    ERIC Educational Resources Information Center

    Thomas, Lisa Carlucci

    2011-01-01

    Rare is the inspirational, spontaneous, transformative moment shared among 20 million people. In the summer of 2010, people around the world were moved by the sighting of a double rainbow--almost a triple rainbow--"all the way across the sky" in Yosemite National Park. Caught on video and posted to by YouTube by Paul Vasquez in January 2010, the…

  20. Double-Glazing Interferometry

    ERIC Educational Resources Information Center

    Toal, Vincent; Mihaylova, Emilia M.

    2009-01-01

    This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for…

  1. Rosette (Double Blossom)

    USDA-ARS?s Scientific Manuscript database

    Rosette, or double blossom, is a serious disease of erect blackberries that is limited to the genus Rubus. Rosette may occur on trailing blackberries and dewberries, but rarely on red and black raspberries. In the United States, rosette occurs from New Jersey to Illinois and southwest to Texas and i...

  2. Sun Packs Double Punch

    NASA Image and Video Library

    On August 3, the sun packed a double punch, emitting a M6.0-class flare at 9:43 am EDT. This video is of the second, slightly stronger M9.3-class flare at 11:41 pm EDT. Both flares had significant ...

  3. Design for Double Rainbow

    ERIC Educational Resources Information Center

    Thomas, Lisa Carlucci

    2011-01-01

    Rare is the inspirational, spontaneous, transformative moment shared among 20 million people. In the summer of 2010, people around the world were moved by the sighting of a double rainbow--almost a triple rainbow--"all the way across the sky" in Yosemite National Park. Caught on video and posted to by YouTube by Paul Vasquez in January 2010, the…

  4. Double-Glazing Interferometry

    ERIC Educational Resources Information Center

    Toal, Vincent; Mihaylova, Emilia M.

    2009-01-01

    This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for…

  5. Memory, double, shadow, and evil.

    PubMed

    McNamara, P

    1994-04-01

    In order to examine shadow dynamics the author explores the phenomenology and mythological associations of the 'double' or Doppelgänger. Current Jungian-inspired theories concerning relations of shadow and double are found to be limited because they do not explain (1) the process of personification of the psychic complex which gives rise to the double, (2) the immediate conditions under which doubling occurs, (3) the conditions which lead to the assignment of evil qualities to the double as shadow. The paper seeks to remedy each of the above limitations by redescribing shadow/double phenomena in terms of autonomous memory phenomena, both personal and trans-personal.

  6. Double Degrees: Double the Trouble or Twice the Return?

    ERIC Educational Resources Information Center

    Russell, A. Wendy; Dolnicar, Sara; Ayoub, Marina

    2008-01-01

    Double degrees (also called joint or combined degrees)--programs of study combining two bachelor degrees--are increasingly popular in Australian universities, particularly among women. A case study using qualitative and quantitative surveys of current and past double degree students is presented. The study indicates that double degrees benefit…

  7. Double Degrees: Double the Trouble or Twice the Return?

    ERIC Educational Resources Information Center

    Russell, A. Wendy; Dolnicar, Sara; Ayoub, Marina

    2008-01-01

    Double degrees (also called joint or combined degrees)--programs of study combining two bachelor degrees--are increasingly popular in Australian universities, particularly among women. A case study using qualitative and quantitative surveys of current and past double degree students is presented. The study indicates that double degrees benefit…

  8. Tests on Double Layer Metalization

    NASA Technical Reports Server (NTRS)

    Woo, D. S.

    1983-01-01

    28 page report describes experiments in fabrication of integrated circuits with double-layer metalization. Double-layer metalization requires much less silicon "real estate" and allows more flexibility in placement of circuit elements than does single-layer metalization.

  9. Measuring the Double Helix

    SciTech Connect

    Mathew-Fenn, R.S.; Das, R.; Harbury, P.A.B.

    2009-05-26

    DNA is thought to behave as a stiff elastic rod with respect to the ubiquitous mechanical deformations inherent to its biology. To test this model at short DNA lengths, we measured the mean and variance of end-to-end length for a series of DNA double helices in solution, using small-angle x-ray scattering interference between gold nanocrystal labels. In the absence of applied tension, DNA is at least one order of magnitude softer than measured by single-molecule stretching experiments. Further, the data rule out the conventional elastic rod model. The variance in end-to-end length follows a quadratic dependence on the number of base pairs rather than the expected linear dependence, indicating that DNA stretching is cooperative over more than two turns of the DNA double helix. Our observations support the idea of long-range allosteric communication through DNA structure.

  10. Remeasuring the double helix

    SciTech Connect

    Mathew-Fenn, Rebecca S.; Das, Rhiju; Harbury, Pehr A.B.

    2008-10-20

    DNA is thought to behave as a stiff elastic rod with respect to the ubiquitous mechanical deformations inherent to its biology. To test this model at short DNA lengths, we measured the mean and variance of end-to-end length for a series of DNA double helices in solution, using small-angle x-ray scattering interference between gold nanocrystal labels. In the absence of applied tension, DNA is at least one order of magnitude softer than measured by single-molecule stretching experiments. Further, the data rule out the conventional elastic rod model. The variance in end-to-end length follows a quadratic dependence on the number of base pairs rather than the expected linear dependence, indicating that DNA stretching is cooperative over more than two turns of the DNA double helix. Our observations support the idea of long-range allosteric communication through DNA structure.

  11. Algebra of Majorana doubling.

    PubMed

    Lee, Jaehoon; Wilczek, Frank

    2013-11-27

    Motivated by the problem of identifying Majorana mode operators at junctions, we analyze a basic algebraic structure leading to a doubled spectrum. For general (nonlinear) interactions the emergent mode creation operator is highly nonlinear in the original effective mode operators, and therefore also in the underlying electron creation and destruction operators. This phenomenon could open up new possibilities for controlled dynamical manipulation of the modes. We briefly compare and contrast related issues in the Pfaffian quantum Hall state.

  12. Double shell liner implosions

    SciTech Connect

    Sorokin, S. A.; Chaikovsky, S. A.

    1997-05-05

    Experiments on the double shell liner (DSL) implosions with and without an initial axial magnetic were performed on the SNOP-3 pulse generator (1.1 MA, 100 ns). In implosions of a DSL without an initial axial magnetic field, high radial compressions of the inner shell were observed, as in previous experiments with an initial axial magnetic field. Possible mechanisms for the formation of the initial azimuthal magnetic field are discussed.

  13. Double face sealing device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce (Inventor)

    1991-01-01

    A double face sealing device is disclosed for mounting between two surfaces to provide an air-tight and fluid-tight seal between a closure member bearing one of the surfaces and a structure or housing bearing the other surface which extends around the opening or hatchway to be closed. The double face sealing device includes a plurality of sections or segments mounted to one of the surfaces, each having a main body portion, a pair of outwardly extending and diverging, cantilever, spring arms, and a pair of inwardly extending and diverging, cantilever, spring arms, an elastomeric cover on the distal, free ends of the outwardly extending and diverging spring arms, and an elastomeric cover on the distal, free, ends of the outwardly extending and diverging spring arms, and an elastomeric cover on the distal, free ends of the inwardly extending and diverging spring arms. The double face sealing device has application or use in all environments requiring a seal, but is particularly useful to seal openings or hatchways between compartments of spacecraft or aircraft.

  14. Colloidal Double Quantum Dots

    PubMed Central

    2016-01-01

    Conspectus Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole–dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single

  15. Colloidal Double Quantum Dots.

    PubMed

    Teitelboim, Ayelet; Meir, Noga; Kazes, Miri; Oron, Dan

    2016-05-17

    Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole-dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single photon

  16. A Biochemical Double Slit

    NASA Astrophysics Data System (ADS)

    Kominis, Iannis

    2011-03-01

    Radical-ion-pair reactions, fundamental in photosynthesis and at the basis of the avian magnetic compass mechanism, have been recently shown to offer a rich playground for applying methods and concepts from quantum measurement/quantum information science. We will demonstrate that radical-ion-pair reactions are almost the exact analog of the optical double slit experiment, i.e. Nature has already engineered biochemical reactions performing the act of quantum interference. We will further elaborate on the non-trivial quantum effects pertaining in these reactions and the recent debate on their fundamental theoretical description that these effects have sparked.

  17. Double Eclipsing Binary Fitting

    NASA Astrophysics Data System (ADS)

    Cagas, P.; Pejcha, O.

    2012-06-01

    The parameters of the mutual orbit of eclipsing binaries that are physically connected can be obtained by precision timing of minima over time through light travel time effect, apsidal motion or orbital precession. This, however, requires joint analysis of data from different sources obtained through various techniques and with insufficiently quantified uncertainties. In particular, photometric uncertainties are often underestimated, which yields too small uncertainties in minima timings if determined through analysis of a χ2 surface. The task is even more difficult for double eclipsing binaries, especially those with periods close to a resonance such as CzeV344, where minima get often blended with each other. This code solves the double binary parameters simultaneously and then uses these parameters to determine minima timings (or more specifically O-C values) for individual datasets. In both cases, the uncertainties (or more precisely confidence intervals) are determined through bootstrap resampling of the original data. This procedure to a large extent alleviates the common problem with underestimated photometric uncertainties and provides a check on possible degeneracies in the parameters and the stability of the results. While there are shortcomings to this method as well when compared to Markov Chain Monte Carlo methods, the ease of the implementation of bootstrapping is a significant advantage.

  18. Doubling an investment

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2004-01-01

    We study the issue of optimal long-term portfolio management in continuous time multi-asset financial markets. Rather than following the abstract notion of ‘utility’ and its implied paradigm of ‘maximization of expected utility’ we suggest a different approach: The investor sets a goal-such as reaching a desired fortune level, or doubling the initial investment-and then operates to minimize the expected time-to-goal, i.e., achieving the goal as quick as possible. We assume the ‘standard model’ of multi-asset financial markets where assets are governed by correlated Geometric Brownian motion dynamics, and study optimality under the criteria of ‘minimization of the expected time-to-goal’. We explicitly compute: (i) the optimal holding strategies; (ii) the dynamics and behavior of the optimal investment portfolios; and, (iii) the statistics-mean, variance, and Laplace transform-of the time-to-goal (under the optimal investment strategy). Also, an investment paradox arising in this context-in which some portfolios have exponential mean growth but have a positive probability of never doubling their initial value-is discussed and explained.

  19. Firewalls from double purity

    NASA Astrophysics Data System (ADS)

    Bousso, Raphael

    2013-10-01

    The firewall paradox is often presented as arising from double entanglement, but I argue that more generally the paradox is double purity. Near-horizon modes are purified by the interior, in the infalling vacuum. Hence, they cannot also be pure alone, or in combination with any third system, as demanded by unitarity. This conflict arises independently of the Page time, for entangled and for pure states. It implies that identifications of Hilbert spaces cannot resolve the paradox. Traditional complementarity requires the unitary identification of infalling matter with a scrambled subsystem of the Hawking radiation. Extending this map to the infalling vacuum overdetermines the out-state. More general complementarity maps (“A=RB,” “ER=EPR”) necessarily fail when the near-horizon zone is pure. I argue that pure-zone states span the microcanonical ensemble, and that this suffices to make the horizon a special place. I advocate that the ability to detect the horizon locally, rather than the degree or probability of violence, is what makes firewalls problematic. Conversely, if the production of matter at the horizon can be dynamically understood and shown to be consistent, then firewalls do not constitute a violation of the equivalence principle.

  20. Colored Flag by Double Refraction.

    ERIC Educational Resources Information Center

    Reid, Bill

    1994-01-01

    Describes various demonstrations that illustrate double refraction and rotation of the plane of polarization in stressed, transparent plastics, with the consequent production of colored designs. (ZWH)

  1. Colored Flag by Double Refraction.

    ERIC Educational Resources Information Center

    Reid, Bill

    1994-01-01

    Describes various demonstrations that illustrate double refraction and rotation of the plane of polarization in stressed, transparent plastics, with the consequent production of colored designs. (ZWH)

  2. Apple Valley Double Star Workshop

    NASA Astrophysics Data System (ADS)

    Brewer, Mark

    2015-05-01

    The High Desert Astronomical Society hosts an annual double star workshop, where participants measure the position angles and separations of double stars. Following the New Generation Science Standards (NGSS), adopted by the California State Board of Education, participants are assigned to teams where they learn the process of telescope set-up and operation, the gathering of data, and the reduction of the data. Team results are compared to the latest epoch listed in the Washington Double Star Catalog (WDS) and papers are written for publication in the Journal of Double Star Observations (JDSO). Each team presents a PowerPoint presentation to their peers about actual hands-on astronomical research.

  3. Double integrated laser interferometer

    NASA Astrophysics Data System (ADS)

    Motyka, Zbigniew

    2003-10-01

    The layout of integrated optical system compromising the basis of proposed solution of double laser interferometer composed of two integrated Michelson's interferometers is presented and shortly discussed. Such an integrated system is designed for work with two lasers of different wavelength. It may serve for mapping surfaces and deformations of objects under investigation with the use of simultaneous recording of two mutually orthogonal gratings, each one composed of equidistant, parallel interference fringes projected onto the surface of such an object. The picture resulting two-coloured is recorded with the digital camera and may be used for obtaining these maps and deformations directly or in the indirect way after suitable digital processing applied to each colour component separately.

  4. Double beta decay: Calorimeters

    NASA Astrophysics Data System (ADS)

    Brofferio, Chiara

    2008-11-01

    Calorimeters or, with a more specific definition, low temperature detectors, have been used by now for more than 15 years in Double Beta Decay (DBD) searches, with excellent results: they compete with Ge diodes for the rank of detectors with the highest sensitivity to the effective neutrino mass, which is defined as a linear combination of the neutrino mass eigenvalues. After a brief introduction to the argument, with some notes on DBD and on bolometers, an update on the now closed experiment CUORICINO and on its successor, CUORE, is given. The fundamental role of background is then revealed and commented, introducing in this way the importance of the specific experiment now under construction, CUORE-0, that will precede CUORE to help optimizing the struggle against surface background. The possible future of this technique is then commented, quoting important R&D studies that are going on, for active shielding bolometers and for scintillating bolometers coupled with light detecting bolometers.

  5. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2007-06-01

    The recent results showing the presence of neutrino oscillations clearly indicate that the difference between the squared mass of neutrinos of different flavors is different from zero, but are unable to determine the nature and the absolute value of the neutrino mass. Neutrinoless double beta decay (DBD) is at present the most powerful tool to ascertain if the neutrino is a Majorana particle and to determine under this condition the absolute value of its mass. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is Dirac or Majorana particle.

  6. New Galactic Double Periodic Variables

    NASA Astrophysics Data System (ADS)

    Mennickent, R. E.; Rosales, J.

    2014-10-01

    We discovered two new Double Periodic Variables in the ASAS catalogue of variable stars, viz., V495 Cen and V4142 Sgr. Other 3 candidates for Double Periodic Variables were found. All systems have relatively long orbital periods. We present improved ephemerides and disentangled light curves.

  7. Empirically Unbinding the Double Bind.

    ERIC Educational Resources Information Center

    Olson, David H.

    The theoretical concept of the double bind and the possibilities for researching it are discussed. The author has observed that theory and research, which should be reciprocal and mutually beneficial, have been working, as concerns the double bind, at odds with one another. Two approaches to empirically investigating the concept are considered via…

  8. Double valve Implantation

    PubMed Central

    Stassano, Paolo; Mannacio, Vito; Musumeci, Antonino; Golino, Alessandro; Maida, Piero; Ferrigno, Vincenzo; Buonocore, Gaetano; Spampinato, Nicola

    1991-01-01

    From January 1976 through December 1987, 194 patients with a mean age of 43.3 ± 13.7 years (range, 11 to 74 years) underwent double (mitral and aortic) replacement of native valves with 8 types of bioprostheses: Carpentier-Edwards, 127 valves; Hancock, 76 valves; Liotta-Bioimplant, 57 valves; Ionescu-Shiley, 53 valves; Vascor, 27 valves; Carpentier-Edwards Pericardial, 22 valves; Angell-Shiley, 20 valves; and Implamedic, 6 valves. Concomitant cardiac procedures were performed in 25 patients (12.8%). There were 18 operative deaths (9.27%). Our retrospective analysis was restricted to 352 bioprostheses implanted in the 176 patients who survived surgery and were considered at risk for valve tissue failure. The overall cumulative duration of follow-up was 1,174.1 patient-years (range, 1 to 13 years). The durations of follow-up for specific valves were: Carpentier-Edwards, 920.2 valve-years; Hancock, 383.8 valve-years; Liotta-Bioimplant, 310.2 valve-years; Ionescu-Shiley, 357.7 valve-years; Vascor, 131.2 valve-years; Carpentier-Edwards Pericardial, 52.0 valve-years; Angell-Shiley, 167.0 valve-years; and Implamedic, 31.0 valve-years. Thirty patients had thromboembolic accidents, for a linearized incidence of 2.5% per patient-year. At 13 years, the actuarial freedom from thromboembolic accidents was 85.8% ± 10.7%. Nine patients had endocarditis, for a linearized incidence of 0.7% per patient-year. At 13 years, the actuarial freedom from endocarditis was 92.0% ± 1.5%. Twenty-four patients had valve tissue failure, for a cumulative linearized incidence of 1.87% per valve-year. The cumulative actuarial probability of freedom from valve tissue failure was 78.6% ± 3.7% at 10 years and 51.2% ± 10.7% at 13 years. The 24 patients with valve tissue failure all underwent reoperation: 20 of these had double valve replacement, 3 had aortic valve replacement alone, and 1 had mitral valve replacement alone. The mean interval between initial valve implantation and reoperation was

  9. The Visual Double Star Catalogs

    NASA Astrophysics Data System (ADS)

    Mason, Brian D.

    2015-08-01

    In visual double star work, production of the first comprehensive attempt to list all discovered pairs in his accessible sky was prepared by S.W. Burnham in 1906. A double star catalog for the southern hemisphere was prepared by R.T.A. Innes et al. in 1927 and the northern hemisphere catalog was updated by R.G. Aitken and E. Doolittle in 1932. Eventually, this led to Lick Observatory maintaining what became known as the Index Catalogue, an all-sky visual double star database.In 1964, under the aegis of Commission 26, the Lick double star database was transferred to the U.S. Naval Observatory where it was redesignated the Washington Double Star Catalog where it and it's ancillary catalogs, have been maintained for over half a century. The current statistics of the catalog and it's supplements are presented as are the enhancements currently under consideration.

  10. Theory of nonmonotonic double layers

    SciTech Connect

    Kim, K.Y.

    1987-12-01

    A simple graphic method of solving the Vlasov--Poisson system associated with nonlinear eigenvalue conditions for arbitrary potential structures is presented. A general analytic formulation for nonmonotonic double layers is presented and illustrated with some particular closed form solutions. This class of double layers satisfies the time stationary Vlasov--Poisson system while requiring a Sagdeev potential, which is a double-valued function of the physical potential. It follows that any distribution function having a density representation as any integer or noninteger power series of potential can never satisfy the nonmonotonic double-layer boundary conditions. A Korteweg--de Vries-like equation is found showing a relationship among the speed of the nonmonotonic double layer, its scale length, and its degree of asymmetry.

  11. Laser double Doppler flowmeter

    NASA Astrophysics Data System (ADS)

    Poffo, L.; Goujon, J.-M.; Le Page, R.; Lemaitre, J.; Guendouz, M.; Lorrain, N.; Bosc, D.

    2014-05-01

    The Laser Doppler flowmetry (LDF) is a non-invasive method for estimating the tissular blood flow and speed at a microscopic scale (microcirculation). It is used for medical research as well as for the diagnosis of diseases related to circulatory system tissues and organs including the issues of microvascular flow (perfusion). It is based on the Doppler effect, created by the interaction between the laser light and tissues. LDF measures the mean blood flow in a volume formed by the single laser beam, that penetrate into the skin. The size of this measurement volume is crucial and depends on skin absorption, and is not directly reachable. Therefore, current developments of the LDF are focused on the use of always more complex and sophisticated signal processing methods. On the other hand, laser Double Doppler Flowmeter (FL2D) proposes to use two laser beams to generate the measurement volume. This volume would be perfectly stable and localized at the intersection of the two laser beams. With FL2D we will be able to determine the absolute blood flow of a specific artery. One aimed application would be to help clinical physicians in health care units.

  12. Double acting bit holder

    DOEpatents

    Morrell, Roger J.; Larson, David A.; Ruzzi, Peter L.

    1994-01-01

    A double acting bit holder that permits bits held in it to be resharpened during cutting action to increase energy efficiency by reducing the amount of small chips produced. The holder consist of: a stationary base portion capable of being fixed to a cutter head of an excavation machine and having an integral extension therefrom with a bore hole therethrough to accommodate a pin shaft; a movable portion coextensive with the base having a pin shaft integrally extending therefrom that is insertable in the bore hole of the base member to permit the moveable portion to rotate about the axis of the pin shaft; a recess in the movable portion of the holder to accommodate a shank of a bit; and a biased spring disposed in adjoining openings in the base and moveable portions of the holder to permit the moveable portion to pivot around the pin shaft during cutting action of a bit fixed in a turret to allow front, mid and back positions of the bit during cutting to lessen creation of small chip amounts and resharpen the bit during excavation use.

  13. Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2010-12-01

    Almost exactly seventy years ago and only one year before his tragic disappearance the ingenious idea of Ettore Majorana is becoming one of the most important step in the development of fundamental physics. The problem of the nature of the neutrino, namely if it is a massless Dirac particle different from its antineutrino or a Majorana particle with finite mass, is discussed. In fact the recent results showing the presence of neutrino oscillations clearly indicates that the difference between the squared mass of neutrinos of different flavours is finite. Neutrinoless double beta decay (DBD) is at present the most powerful tool to determine the effective value of the mass of a Majorana neutrino. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already at least partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is indeed a Majorana particle.

  14. Double Diffusive Plumes

    NASA Astrophysics Data System (ADS)

    Sutherland, Bruce; Lee, Brace

    2008-11-01

    Sour gas flares attempt to dispose of deadly H2S gas through combustion. What does not burn rises as a buoyant plume. But the gas is heavier than air at room temperature, so as the rising gas cools eventually it becomes negatively buoyant and descends back to the ground. Ultimately, our intent is to predict the concentrations of the gas at ground level in realistic atmospheric conditions. As a first step towards this goal we have performed laboratory experiments examining the structure of a steady state plume of hot and salty water that rises buoyantly near the source and descends as a fountain after it has cooled sufficiently. We call this a double-diffusive plume because its evolution is dictated by the different (turbulent) diffusivities of heat and salt. A temperature and conductivity probe measures both the salinity and temperature along the centreline of the plume. The supposed axisymmetric structure of the salinity concentration as it changes with height is determined by light-attenuation methods. To help interpret the results, a theory has been successfully adapted from the work of Bloomfield and Kerr (2000), who developed coupled equations describing the structure of fountains. Introducing a new empirical parameter for the relative rates of turbulent heat and salt diffusion, the predictions are found to agree favourably with experimental results.

  15. Antarctic radiation exposure doubles

    NASA Astrophysics Data System (ADS)

    Blue, Charles

    New data reveal that the Antarctic Peninsula received twice its normal maximum dose of hazardous solar ultraviolet radiation in December 1990. The prolonged persistence of the ozone hole over Antarctica caused an increased exposure of radiation, according to a paper published in the October issue of Geophysical Research Letters.John Frederick and Amy D. Alberts of the University of Chicago calculated the amount of ultraviolet solar spectral radiation from data collected at Palmer Station, Antarctica. During the spring of 1990 the largest observed values for ultraviolet radiation were approximately double the values expected, based on previous years. “The measurements from Palmer Station are consistent with similar data from McMurdo Sound, where a factor of three [ultraviolet radiation] enhancement was recorded, according to work by Knut Stamnes and colleagues at the University of Alaska,” Frederick said. “The radiation levels observed over Palmer Station in December 1990 may be the largest experienced in this region of the world since the development of the Earth's ozone layer,” he added.

  16. K2P2— A Photometry Pipeline for the K2 Mission

    NASA Astrophysics Data System (ADS)

    Lund, Mikkel N.; Handberg, Rasmus; Davies, Guy R.; Chaplin, William J.; Jones, Caitlin D.

    2015-06-01

    With the loss of a second reaction wheel, resulting in the inability to point continuously and stably at the same field of view, the NASA Kepler satellite recently entered a new mode of observation known as the K2 mission. The data from this redesigned mission present a specific challenge; the targets systematically drift in position on an ∼6 hr timescale, inducing a significant instrumental signal in the photometric time series—this greatly impacts the ability to detect planetary signals and perform asteroseismic analysis. Here we detail our version of a reduction pipeline for K2 target pixel data, which automatically defines masks for all targets in a given frame; extracts the target’s flux and position time series; corrects the time series based on the apparent movement on the CCD (either in 1D or 2D), combined with the correction of instrumental and/or planetary signals via the Kepler Asteroseismic Science Operations Center (KASOC) filter, thus rendering the time series ready for asteroseismic analysis; computes power spectra for all targets and identifies potential contaminations between targets. From a test of our pipeline on a sample of targets from the K2 campaign 0, the recovery of data for multiple targets increases the amount of potential light curves by a factor of ≥slant 10. Our pipeline could be applied to the upcoming TESS and PLATO 2.0 missions.

  17. Materials Data on MgFe2P2(HO)18 (SG:2) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. Materials Data on MnAl2P2(HO)18 (SG:2) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Materials Data on MgAl2P2(HO)18 (SG:2) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on Al2P2O11F (SG:19) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-10

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on KAl2P2H5O11 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Materials Data on Al2P2H9NO11 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-05

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. Materials Data on KAl2P2H4O11 (SG:19) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-10

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. Materials Data on Zr2P2O9 (SG:12) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-05-13

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. Materials Data on KAl2P2H5O11 (SG:19) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Materials Data on KFe2P2H5O11 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  7. Materials Data on Mo2P2O11 (SG:11) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  8. Time resolved nonlinear response of Sn2P2S6:Sb to nanosecond pulse excitation

    NASA Astrophysics Data System (ADS)

    Shumelyuk, A.; Skrypka, Y.; Odoulov, S.; Basun, S. A.; Halliburton, L. E.; Evans, D. R.

    2017-06-01

    The temporal variations of SPS:Sb transmission are measured within a 10 orders of magnitude time range (from a few nanoseconds to ten seconds) with a red diode laser beam, after illumination of the sample with a nanosecond pulse of green light. The measurements revealed a sequence of darkening and bleaching processes that are sensitive to the intensities of pre-illumination and testing beams, or the sample temperature, or both. This allowed for identifying particular nonlinear processes that manifest themselves in changes of transmission.

  9. Protein-Protein Interaction Inhibition (2P2I)-Oriented Chemical Library Accelerates Hit Discovery.

    PubMed

    Milhas, Sabine; Raux, Brigitt; Betzi, Stéphane; Derviaux, Carine; Roche, Philippe; Restouin, Audrey; Basse, Marie-Jeanne; Rebuffet, Etienne; Lugari, Adrien; Badol, Marion; Kashyap, Rudra; Lissitzky, Jean-Claude; Eydoux, Cécilia; Hamon, Véronique; Gourdel, Marie-Edith; Combes, Sébastien; Zimmermann, Pascale; Aurrand-Lions, Michel; Roux, Thomas; Rogers, Catherine; Müller, Susanne; Knapp, Stefan; Trinquet, Eric; Collette, Yves; Guillemot, Jean-Claude; Morelli, Xavier

    2016-08-19

    Protein-protein interactions (PPIs) represent an enormous source of opportunity for therapeutic intervention. We and others have recently pinpointed key rules that will help in identifying the next generation of innovative drugs to tackle this challenging class of targets within the next decade. We used these rules to design an oriented chemical library corresponding to a set of diverse "PPI-like" modulators with cores identified as privileged structures in therapeutics. In this work, we purchased the resulting 1664 structurally diverse compounds and evaluated them on a series of representative protein-protein interfaces with distinct "druggability" potential using homogeneous time-resolved fluorescence (HTRF) technology. For certain PPI classes, analysis of the hit rates revealed up to 100 enrichment factors compared with nonoriented chemical libraries. This observation correlates with the predicted "druggability" of the targets. A specific focus on selectivity profiles, the three-dimensional (3D) molecular modes of action resolved by X-ray crystallography, and the biological activities of identified hits targeting the well-defined "druggable" bromodomains of the bromo and extraterminal (BET) family are presented as a proof-of-concept. Overall, our present study illustrates the potency of machine learning-based oriented chemical libraries to accelerate the identification of hits targeting PPIs. A generalization of this method to a larger set of compounds will accelerate the discovery of original and potent probes for this challenging class of targets.

  10. Materials Data on Ca2P2O7 (SG:14) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-02-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. Materials Data on CaSn2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-11

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Materials Data on Hg2P2S7 (SG:5) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  13. Materials Data on CeTl2P2S7 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  14. Materials Data on K2P2H2O7 (SG:11) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-05

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. THE SYNTHESIS OF LEAD PYROPHOSPHATE, PB2P2O7, IN WATER

    EPA Science Inventory

    Polyphosphates are used in the drinking water to prevent the precipitation of cations such as calcium and iron. The possible negative impact of using polyphosphates is the undesirable complexation of lead which could result in elevated lead levels in consumer’s tap water. Altho...

  16. Experimental study of the 2p-2h band in {sup 111}Sn

    SciTech Connect

    Ganguly, S.; Banerjee, P.; Ray, I.; Kshetri, R.; Raut, R.; Bhattacharya, S.; Saha-Sarkar, M.; Goswami, A.; Basu, S. K.

    2008-09-15

    The {delta}I=2 intruder band in {sup 111}Sn, built upon the 4074.3 keV state, was studied. The states were populated in the {sup 100}Mo({sup 20}Ne, {alpha}5n) reaction at a beam energy of 136 MeV. Mean lifetimes of five states up to 8737.2 keV (spin 43/2{sup -}) have been measured for the first time using the Doppler shift attenuation method. In addition, an upper limit of mean lifetime has been estimated for the 9860.0 keV (spin 47/2{sup -}) state. The B(E2) values, derived from the present lifetime results, indicate a quadrupole deformation of {beta}{sub 2}=0.28{+-}0.02 for the 31/2{sup -} state and decrease progressively with spin, suggesting a reduction in collectivity. The dynamic moment of inertia for the band also decreases continuously up to the highest observed frequencies. These results, along with the predictions of a total Routhian surface calculation, suggest that the {delta}I=2 band in {sup 111}Sn undergoes a change of shape from collective prolate to triaxial with increase in spin and possibly terminates in a noncollective oblate state at a high spin.

  17. Materials Data on K2In2P2HO10 (SG:19) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-23

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. Materials Data on Ca(Cu2P)2 (SG:136) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-02-11

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Materials Data on K2P2H2O7 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on Re2P2O11 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-10

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. 2p2h effects on the weak pion production cross section

    SciTech Connect

    Mariano, A.; Barbero, C.

    2015-05-15

    The ν{sub l}n → l{sup −}p QE reaction on the A-target is used as a signal event or/and to reconstruct the neutrino energy, using two-body kinematics. Competition of another processes could lead to misidentification of the arriving neutrinos, being important the fake events coming from the CC1π background. A precise knowledge of cross sections is a prerequisite in order to make simulations in event generators to substract the fake ones from the QE countings, and in this contribution we analyze the different nuclear effects on the CC1π channel. Our calculations also can be extended for the NC case.

  2. Radiative transitions involving the (2p2)(3 Pe) metastable autodetaching of H(-)

    NASA Technical Reports Server (NTRS)

    Jacobs, V. L.; Bhatia, A. K.; Temkin, A.

    1974-01-01

    The absorption coefficient for the free-bound transition H (ls) + e(-)+ h omega yields H(-)(2 sq p,(3)P(e)) is calculated (together with the differential emission rate for the inverse process) using ls - 2s - 2p close coupling continuum wave functions and a Hylleraas bound state wave function. A maximum in the absorption and emission spectra is found to occur at a photon wavelength of 1219.5 A, which is 2 A closer to the Lyman alpha line than predicted by the calculations of Drake, and is in closer agreement with the stellar absorption feature identified by Heap and Stecher. The free-bound absorption process appears to be a significant source of continuous ultraviolet opacity.

  3. Materials Data on As2P2S7 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. α and 2p2n emission in fast neutron-induced reactions on Ni60

    DOE PAGES

    Fotiades, N.; Devlin, M.; Haight, R. C.; ...

    2015-06-19

    The cross sections for populating the residual nucleus in the reaction AZX(n,x)A-4Z-2Y exhibit peaks as a function of incident neutron energy corresponding to the (n,n'α) reaction and, at higher energy, to the (n,2p3n) reaction. In addition, the relative magnitudes of these peaks vary with the Z of the target nucleus.

  5. Materials Data on Sn2P2O7 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-07-14

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Materials Data on ZnCr2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  7. Materials Data on ZnCo2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  8. Materials Data on CaMo2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Materials Data on CaFe2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Materials Data on Mn2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. Materials Data on MgCr2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Materials Data on ZnSn2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  13. Materials Data on MgFe2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  14. Materials Data on CaMn2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Materials Data on CaCr2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  16. Materials Data on MgMo2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  17. Materials Data on MgMn2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. Materials Data on Cr2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Materials Data on Mo2P2O9 (SG:62) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on LiV2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-28

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on LiCr2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-28

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Materials Data on LiCo2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-29

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. Materials Data on LiNi2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-31

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. Materials Data on LiMo2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-15

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. Materials Data on LiTi2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-27

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Materials Data on LiFe2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-28

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  7. Materials Data on NaMo2P2O9 (SG:62) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-10-28

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  8. Materials Data on Al2P2H4O11 (SG:61) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-05-31

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Materials Data on KV2P2H4O13 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-23

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Materials Data on Fe2P2H4NO8 (SG:15) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. A Handbook of Double Stars

    NASA Astrophysics Data System (ADS)

    Crossley, Edward; Gledhill, Joseph; Wilson, James M.

    2011-11-01

    Preface; Part I. Historical, and Descriptive of Instruments and Methods: 1. Historical introduction; 2. The Equatorial: its construction and adjustments; 3. Some account of the Equatorials which have been used by double-star observers; 4. The micrometer; 5. Methods of observing double stars; Part II. On the Calculation of the Orbit of a Binary Star: 1. Introduction; 2. Example of an orbit worked by a graphical method; 3. Dr. Doberck's example of an orbit worked by analytical methods; 4. On relative rectilinear motion; 5. On the effect of proper motion and parallax on the observed position angles and distance of an optically double star; 6. On the errors of observation and the combination of observations; Part III. The Catalogue and Measures: Introductory remarks; A catalogue of binary and other double starts deserving of attention; Lists of measures, with historical notes, etc.; Supplementary list of measures; Appendix; Additional notes to measures; Binary stars classified; Note on systematic errors in the measures of angle and distance of double stars; Part IV. Bibliography: A. Some of the most important works and papers on double stars; B. Some papers on the micrometer; C. Some papers on the colours of double stars; Additional notes; Corrections 1880.

  12. Advanced double layer capacitors

    NASA Technical Reports Server (NTRS)

    Sarangapani, S.; Lessner, P.; Forchione, J.; Laconti, A. B.

    1989-01-01

    There is a need for large amounts of power to be delivered rapidly in a number of airborne and space systems. Conventional, portable power sources, such as batteries, are not suited to delivering high peak power pulses. The charge stored at the electrode-electrolyte double layer is, however, much more assessible on a short time scale. Devices exploiting this concept were fabricated using carbon and metal oxides (Pinnacle Research) as the electrodes and sulfuric acid as the electrolyte. The approach reported, replaces the liquid sulfuric acid electrolyte with a solid ionomer electrolyte. The challenge is to form a solid electrode-solid ionomer electrolyte composite which has a high capacitance per geometric area. The approach to maximize contact between the electrode particles and the ionomer was to impregnate the electrode particles using a liquid ionomer solution and to bond the solvent-free structure to a solid ionomer membrane. Ruthenium dioxide is the electrode material used. Three strategies are being pursued to provide for a high area electrode-ionomer contact: mixing of the RuOx with a small volume of ionomer solution followed by filtration to remove the solvent, and impregnation of the ionomer into an already formed RuOx electrode. RuOx powder and electrodes were examined by non-electrochemical techniques. X-ray diffraction has shown that the material is almost pure RuO2. The electrode structure depends on the processing technique used to introduce the Nafion. Impregnated electrodes have Nafion concentrated near the surface. Electrodes prepared by the evaporation method show large aggregates of crystals surrounded by Nafion.

  13. The Double Chooz Outer Veto

    NASA Astrophysics Data System (ADS)

    Toups, Matthew

    2009-05-01

    Measuring a non-zero value for the neutrino mixing angle θ13 sets the scale for future precision measurements in the lepton sector such as CP violation. The Double Chooz experiment will begin taking data later this year with a sensitivity to 2̂(2θ13) in the 0.02 - 0.03 range, improving on the CHOOZ bound by about an order of magnitude. Efficient rejection of backgrounds induced by cosmic muons is essential to achieving this sensitivity. The Double Chooz Outer Veto plays a crucial role in vetoing and tagging these muons. An update on the status of the Double Chooz Outer Veto will be presented.

  14. Aspects of the doubled worldsheet

    NASA Astrophysics Data System (ADS)

    Driezen, Sibylle; Sevrin, Alexander; Thompson, Daniel C.

    2016-12-01

    We clarify the relation between various approaches to the manifestly T-duality symmetric string. We explain in detail how the PST covariant doubled string arises from an unusual gauge fixing. We pay careful attention to the role of "spectator" fields in this process and also show how the T-duality invariant doubled dilaton emerges naturally. We extend these ideas to non-Abelian T-duality and show they give rise to the duality invariant formalism based on the semi-Abelian Drinfeld Double. We then develop the N = (0, 1) supersymmetric duality invariant formalism.

  15. A Double Pendulum "Art Machine"

    ERIC Educational Resources Information Center

    Romer, R. H.

    1970-01-01

    Describes a double pendulum apparatus and its mode of operation to produce a great variety of figures similar to Lissajous figures. The author suggests that several advanced physics topics can be studied with the aid of this instrument. Bibliography. (LC)

  16. Double-Base Binder Improvement

    DTIC Science & Technology

    The general objective of this program is to improve the mechanical properties of composite modified double base ( CMDB ) propellants, with particular emphasis upon those prepared by the slurry cast process.

  17. Large Double-ringed Basin

    NASA Image and Video Library

    2000-08-05

    Taken about 40 minutes before NASA Mariner 10 made its close approach to Mercury on Sept. 21,1974, this picture shows a large double-ringed basin center of picture located in the planet south polar region

  18. Entanglement purification with double selection

    SciTech Connect

    Fujii, Keisuke; Yamamoto, Katsuji

    2009-10-15

    We investigate an entanglement purification protocol with double-selection process, which works under imperfect local operations. Compared with the usual protocol with single selection, this double-selection method has higher noise thresholds for the local operations and quantum communication channels and achieves higher fidelity of purified states. It also provides a yield comparable to that of the usual protocol with single selection. We discuss on general grounds how some of the errors which are introduced by local operations are left as intrinsically undetectable. The undetectable errors place a general upper bound on the purification fidelity. The double selection is a simple method to remove all the detectable errors in the first order, so that the upper bound on the fidelity is achieved in the low-noise regime. The double selection is further applied to purification of multipartite entanglement such as two-colorable graph states.

  19. [The double and his theatre].

    PubMed

    Trillet, M

    1996-01-01

    Professor Paul Girard dedicated an important part of his scientific works to the notion of the Double. He was naturally prompted to such an investigation because of his interest in lateralization disorders and in the problems of cerebral functional asymmetry. We present his conception, in view of recent information of modern neuropsychology as regards identification and recognition processes, as well as anticipation and familiarity operations. Beyond the problem of the Double, the search for Identity is considered in artistic and literary activity.

  20. Maize sugary enhancer1 (se1) is a presence-absence variant of a previously uncharacterized gene and development of educational videos to raise the profile of plant breeding and improve curricula

    NASA Astrophysics Data System (ADS)

    Haro von Mogel, Karl J.

    Carbohydrate metabolism is a biologically, economically, and culturally important process in crop plants. Humans have selected many crop species such as maize (Zea mays L.) in ways that have resulted in changes to carbohydrate metabolic pathways, and understanding the underlying genetics of this pathway is therefore exceedingly important. A previously uncharacterized starch metabolic pathway mutant, sugary enhancer1 (se1), is a recessive modifier of sugary1 (su1) sweet corn that increases the sugar content while maintaining an appealing creamy texture. This allele has been incorporated into many sweet corn varieties since its discovery in the 1970s, however, testing for the presence of this allele has been difficult. A genetic stock was developed that allowed the presence of se1 to be visually scored in segregating ears, which were used to genetically map se1 to the deletion of a single gene model located on the distal end of the long arm of chromosome 2. An analysis of homology found that this gene is specific to monocots, and the gene is expressed in the endosperm and developing leaf. The se1 allele increased water soluble polysaccharide (WSP) and decreased amylopectin in maize endosperm, but there was no overall effect on starch content in mature leaves due to se1. This discovery will lead to a greater understanding of starch metabolism, and the marker developed will assist in breeding. There is a present need for increased training for plant breeders to meet the growing needs of the human population. To raise the profile of plant breeding among young students, a series of videos called Fields of Study was developed. These feature interviews with plant breeders who talk about what they do as plant breeders and what they enjoy about their chosen profession. To help broaden the education of students in college biology courses, and assist with the training of plant breeders, a second video series, Pollination Methods was developed. Each video focuses on one or two

  1. The double loop mattress suture

    PubMed Central

    Biddlestone, John; Samuel, Madan; Creagh, Terry; Ahmad, Tariq

    2014-01-01

    An interrupted stitch type with favorable tissue characteristics will reduce local wound complications. We describe a novel high-strength, low-tension repair for the interrupted closure of skin, cartilage, and muscle, the double loop mattress stitch, and compare it experimentally with other interrupted closure methods. The performance of the double loop mattress technique in porcine cartilage and skeletal muscle is compared with the simple, mattress, and loop mattress interrupted sutures in both a novel porcine loading chamber and mechanical model. Wound apposition is assessed by electron microscopy. The performance of the double loop mattress in vivo was confirmed using a series of 805 pediatric laparotomies/laparoscopies. The double loop mattress suture is 3.5 times stronger than the loop mattress in muscle and 1.6 times stronger in cartilage (p ≤ 0.001). Additionally, the double loop mattress reduces tissue tension by 66% compared with just 53% for the loop mattress (p ≤ 0.001). Wound gapping is equal, and wound eversion appears significantly improved (p ≤ 0.001) compared with the loop mattress in vitro. In vivo, the double loop mattress performs as well as the loop mattress and significantly better than the mattress stitch in assessments of wound eversion and dehiscence. There were no episodes of stitch extrusion in our series of patients. The mechanical advantage of its intrinsic pulley arrangement gives the double loop mattress its favorable properties. Wound dehiscence is reduced because this stitch type is stronger and exerts less tension on the tissue than the mattress stitch. We advocate the use of this novel stitch wherever a high-strength, low-tension repair is required. These properties will enhance wound repair, and its application will be useful to surgeons of all disciplines. PMID:24698436

  2. Double metric, generalized metric, and α' -deformed double field theory

    NASA Astrophysics Data System (ADS)

    Hohm, Olaf; Zwiebach, Barton

    2016-03-01

    We relate the unconstrained "double metric" of the "α' -geometry" formulation of double field theory to the constrained generalized metric encoding the spacetime metric and b -field. This is achieved by integrating out auxiliary field components of the double metric in an iterative procedure that induces an infinite number of higher-derivative corrections. As an application, we prove that, to first order in α' and to all orders in fields, the deformed gauge transformations are Green-Schwarz-deformed diffeomorphisms. We also prove that to first order in α' the spacetime action encodes precisely the Green-Schwarz deformation with Chern-Simons forms based on the torsionless gravitational connection. This seems to be in tension with suggestions in the literature that T-duality requires a torsionful connection, but we explain that these assertions are ambiguous since actions that use different connections are related by field redefinitions.

  3. Double shrinking sparse dimension reduction.

    PubMed

    Zhou, Tianyi; Tao, Dacheng

    2013-01-01

    Learning tasks such as classification and clustering usually perform better and cost less (time and space) on compressed representations than on the original data. Previous works mainly compress data via dimension reduction. In this paper, we propose "double shrinking" to compress image data on both dimensionality and cardinality via building either sparse low-dimensional representations or a sparse projection matrix for dimension reduction. We formulate a double shrinking model (DSM) as an l(1) regularized variance maximization with constraint ||x||(2)=1, and develop a double shrinking algorithm (DSA) to optimize DSM. DSA is a path-following algorithm that can build the whole solution path of locally optimal solutions of different sparse levels. Each solution on the path is a "warm start" for searching the next sparser one. In each iteration of DSA, the direction, the step size, and the Lagrangian multiplier are deduced from the Karush-Kuhn-Tucker conditions. The magnitudes of trivial variables are shrunk and the importances of critical variables are simultaneously augmented along the selected direction with the determined step length. Double shrinking can be applied to manifold learning and feature selections for better interpretation of features, and can be combined with classification and clustering to boost their performance. The experimental results suggest that double shrinking produces efficient and effective data compression.

  4. Double field theory inspired cosmology

    SciTech Connect

    Wu, Houwen; Yang, Haitang E-mail: hyanga@scu.edu.cn

    2014-07-01

    Double field theory proposes a generalized spacetime action possessing manifest T-duality on the level of component fields. We calculate the cosmological solutions of double field theory with vanishing Kalb-Ramond field. It turns out that double field theory provides a more consistent way to construct cosmological solutions than the standard string cosmology. We construct solutions for vanishing and non-vanishing symmetry preserving dilaton potentials. The solutions assemble the pre- and post-big bang evolutions in one single line element. Our results show a smooth evolution from an anisotropic early stage to an isotropic phase without any special initial conditions in contrast to previous models. In addition, we demonstrate that the contraction of the dual space automatically leads to both an inflation phase and a decelerated expansion of the ordinary space during different evolution stages.

  5. Supergravity with doubled spacetime structure

    NASA Astrophysics Data System (ADS)

    Ma, Chen-Te; Pezzella, Franco

    2017-03-01

    Double field theory (DFT) is a low-energy effective theory of a manifestly O (D ,D ) -invariant formulation of the closed-string theory. The theory is based on a doubling of the D -dimensional spacetime structure and, in order to preserve the gauge symmetry provided by the invariance under generalized diffeomorphisms, a constraint has to be imposed on fields and gauge parameters. In this paper, we consider a DFT-inspired supergravity by using a suitable commutative star product of fields and gauge parameters with the aim of studying the corresponding algebraic structure. This star product is not associative, implying the nonclosure of the gauge transformations. Despite this, we get a consistent theory in which an orthogonality condition of momenta associated with double fields is also necessary to have a closed gauge algebra. We first start from the simplest case of one compact spatial dimension. Then, the extension to the case of d spatial dimensions is taken into consideration.

  6. New double soft emission theorems

    NASA Astrophysics Data System (ADS)

    Cachazo, Freddy; He, Song; Yuan, Ellis Ye

    2015-09-01

    We study the behavior of the tree-level S-matrix of a variety of theories as two particles become soft. By analogy with the recently found subleading soft theorems for gravitons and gluons, we explore subleading terms in double soft emissions. We first consider double soft scalar emissions and find subleading terms that are controlled by the angular momentum operator acting on hard particles. The order of the subleading theorems depends on the presence or not of color structures. Next we obtain a compact formula for the leading term in a double soft photon emission. The theories studied are a special Galileon, Dirac-Born-Infeld, Einstein-Maxwell-Scalar, nonlinear sigma model and Yang-Mills-Scalar. We use the recently found Cachazo-He-Yuan representation of these theories in order to give a simple proof of the leading order part of all these theorems.

  7. Azeglio Bemporad and the "BEM" Double Stars

    NASA Astrophysics Data System (ADS)

    Smith, Steven; Prunotto, Marco

    2017-07-01

    This paper aims to describe the scientific context and the life of early 20th century Italian astronomer Azeglio Bemporad (1875-1945), his work on double stars, and how the “BEM” doubles were incorporated into the Washington Double Star catalog. Included are new measures, a complete photo gallery of all 61 of his double star systems, and copies of his double star publications.

  8. Reactions of R(2)P-P(SiMe(3))Li with [(R'(3)P)(2)PtCl(2)]. A general and efficient entry to phosphanylphosphinidene complexes of platinum. Syntheses and structures of [(eta(2)-P=(i)Pr(2))Pt(p-Tol(3)P)(2)], [(eta(2)-P=(t)Bu(2))Pt(p-Tol(3)P)(2)], [{eta(2)-P=(N(i)Pr(2))(2)}Pt(p-Tol(3)P)(2)] and [{(Et(2)PhP)(2)Pt}(2)P(2)].

    PubMed

    Domańska-Babul, Wioleta; Chojnacki, Jaroslaw; Matern, Eberhard; Pikies, Jerzy

    2009-01-07

    The reactions of lithium derivatives of diphosphanes R(2)P-P(SiMe(3))Li (R = (t)Bu, (i)Pr, Et(2)N and (i)Pr(2)N) with [(R'(3)P)(2)PtCl(2)] (R'(3)P = Et(3)P, Et(2)PhP, EtPh(2)P and p-Tol(3)P) proceed in a facile manner to afford side-on bonded phosphanylphosphinidene complexes of platinum [(eta(2)-P=R(2))Pt(PR'(3))(2)]. The related reactions of Ph(2)P-P(SiMe(3))Li with [(R'(3)P)(2)PtCl(2)] did not yield [(eta(2)-P=PPh(2))Pt(PR'(3))(2)] and resulted mainly in the formation of [{(R'(3)P)(2)Pt}(2)P(2)], Ph(2)P-PLi-PPh(2), (Me(3)Si)(2)PLi and (Me(3)Si)(3)P. Crystallographic data are reported for the compounds [(eta(2)-P=R(2))Pt(p-Tol(3)P)(2)] (R = (t)Bu, (i)Pr, ((i)Pr(2)N)(2)P) and for [{(Et(2)PhP)(2)Pt}(2)P(2)].

  9. Recent Argon Double Shell Experiments on Double Eagle

    NASA Astrophysics Data System (ADS)

    Sze, H.; Fisher, A.; Coleman, P.; Failor, B.; Levine, J.; Song, Y.; Waisman, E.; Cochran, F.; Velikovich, A.; Davis, J.

    1999-11-01

    With the objective of improved x-ray yield and pinch quality for long (200 nanoseconds) implosion time z-pinches, we have tested a double shell nozzle on the Double Eagle generator. Theory and some experiments on GIT-12 suggest that the double shell may help mitigate instability growth during the runin phase of the implosion. For our experiments, argon gas, with a freon (chlorine) tracer in some cases, was imploded using peak currents up to 4 megamps. The nominal shell radii were 1.5 and 3.5 cm. A variety of optical, yield and spectroscopic measurements were made to diagnose the tests. The best radiative output, 12 kJ of K-shell in a 10 ns pulse width, is comparable to that achieved with a 7 cm uniform fill load. We will present data on the pinch’s performance as the ratio of inner to outer masses was varied. (A companion paper, Cochran et. al., discusses MHD modeling of the double shell load.)

  10. Current driven weak double layers

    NASA Technical Reports Server (NTRS)

    Chanteur, Gerard

    1987-01-01

    Double layers in plasmas can be created by different means. For example, a potential difference forms between two plasmas with different temperatures, in a plasma jet flowing along a converging magnetic field, in a quiescent plasma submitted to an external difference of potential, or in a turbulent plasma carrying an electric charge. The first three cases can be current-free, but not necessarily, although the numerical simulations were made under such conditions for the first two points. Apart from the third case, which is mainly of interest for laboratory experiments, these double layers are good candidates for accelerating the auroral electrons to the few kiloelectron volts observed.

  11. Double stranded nucleic acid biochips

    DOEpatents

    Chernov, Boris; Golova, Julia

    2006-05-23

    This invention describes a new method of constructing double-stranded DNA (dsDNA) microarrays based on the use of pre-synthesized or natural DNA duplexes without a stem-loop structure. The complementary oligonucleotide chains are bonded together by a novel connector that includes a linker for immobilization on a matrix. A non-enzymatic method for synthesizing double-stranded nucleic acids with this novel connector enables the construction of inexpensive and robust dsDNA/dsRNA microarrays. DNA-DNA and DNA-protein interactions are investigated using the microarrays.

  12. Double trisomy in spontaneous abortions.

    PubMed

    Reddy, K S

    1997-12-01

    Cytogenetic data on products of conception from spontaneous abortions studied over a 10-year period have been reviewed for double trisomies. A total of 3034 spontaneous abortions were karyotyped between 1986 and 1997. Twenty-two cases with double trisomy, one case with triple trisomy, and a case with a trisomy and monosomy were found. The tissues studied were mostly sac, villi, or placenta. The gestational age ranged from 6 to 11 weeks and the mean age was 8.2 +/- 1.7 (SD) weeks. The mean maternal age in years was 35.9 +/- 5.3. Of the twenty-two cases, four were mosaics. All but two of the cases involved autosomal aneuploidies. The double trisomies included chromosomes 2, 4, 5, 7, 8, 12, 13, 14, 15, 16, 17, 18, 20, 21, and 22. The chromosomes that were trisomic in more than one double trisomy case were numbers 16 (8 cases), 8 (5 cases), 15 (4 cases), 2, 13, and 21 (3 cases each), and 5, 7, 14, 18, 20, 22, and X (2 cases). The triple trisomy involved chromosomes 18, 21, and X. The monosomy and trisomy case was a mosaic, with a monosomy 21 in all cells and some cells also with a trisomy 5. The double trisomies cited for the first time in this study were 4/13, 5/16, 8/14, 8/15, 14/21, 15/20, and 7/12. The pooled mean maternal age for double trisomy cases (34.1 +/- 5.7 years) was higher than that for single trisomy cases (31 +/- 6.1 years). The difference was statistically significant at P = < 0.001. The pooled mean gestational age of spontaneous abortions was lower for double trisomy (8.7 +/- 2.2 weeks) than for reported single trisomy cases (10.1 +/- 2.9 weeks). This difference is also statistically significant at P = < 0.001. The sex ratio among double trisomies was 15 females to 13 males. This difference was not statistically significant from the expected 1:1.

  13. Double-negative acoustic metamaterial.

    PubMed

    Li, Jensen; Chan, C T

    2004-11-01

    We show here the existence of acoustic metamaterial, in which both the effective density and bulk modulus are simultaneously negative, in the true and strict sense of an effective medium. Our double-negative acoustic system is an acoustic analogue of Veselago's medium in electromagnetism, and shares many unique consequences, such as negative refractive index. The double negativity in acoustics is derived from low-frequency resonances, as in the case of electromagnetism, but the negative density and modulus are derived from a single resonance structure as distinct from electromagnetism in which the negative permeability and negative permittivity originates from different resonance mechanisms.

  14. Double-branched vortex generator

    NASA Technical Reports Server (NTRS)

    Cantwell, E. R.; Westphal, R. V.; Mehta, R. D.

    1985-01-01

    In order to assess the suitability of using a double branched vortex generator in parametric studies involving vortex interactions, an experimental study of the main vortex and secondary flows produced by a double branched vortex generator was conducted in a 20-by-40 cm indraft wind tunnel. Measurements of the cross flow velocities were made with a five hole pressure probe from which vorticity contours and vortex parameters were derived. The results showed that the optimum configuration consisted of chord extensions with the absence of a centerbody.

  15. Correlating double-difference of charge radii with quadrupole deformation and B (E 2 ) in atomic nuclei

    NASA Astrophysics Data System (ADS)

    Sun, B. H.; Liu, C. Y.; Wang, H. X.

    2017-01-01

    A good linear correlation is found between the double-difference of charge radius δ R2 p -2 n(Z ,N ) with that of quadrupole deformation data in even-even nuclei. This results in a further improved charge radius relation that holds in a precision of about 5 ×10-3 fm. The new relation can be generalized to the reduced electric quadrupole transition probability B (E 2 ) between the first 2+ state and the 0+ ground state, and the mean lifetime τ of the first 2+ state. Same correlations are also seen in global nuclear models such as Hartree-Fock-Bogoliubov (HFB-24) and relativistic mean field (RMF); however, they are not consistent with the experimental data.

  16. Natural products: DNA double whammy

    NASA Astrophysics Data System (ADS)

    Gates, Kent S.

    2014-06-01

    The lomaiviticins are exceedingly potent antibiotic agents, but the mechanism responsible for this activity has so far been unclear. Now, efficient generation of double-strand breaks in DNA by lomaiviticin A has been linked to the remarkable cytotoxicity of these diazobenzofluorene-containg natural products.

  17. The double well mass filter

    DOE PAGES

    Gueroult, Renaud; Rax, Jean -Marcel; Fisch, Nathaniel J.

    2014-02-03

    Various mass filter concepts based on rotating plasmas have been suggested with the specific purpose of nuclear waste remediation. We report on a new rotating mass filter combining radial separation with axial extraction. Lastly, the radial separation of the masses is the result of a “double-well” in effective radial potential in rotating plasma with a sheared rotation profile.

  18. Double spaces with isolated singularities

    SciTech Connect

    Cheltsov, I A

    2008-02-28

    The non-rationality is proved for double covers of P{sup n} branched over a hypersurface F subset of P{sup n} of degree 2n>=8 with isolated singularities such that the multiplicity of each singular point of F does not exceed 2(n-2) and the projectivization of its tangent cone is smooth. Bibliography: 15 titles.

  19. A Double-Minded Fractal

    ERIC Educational Resources Information Center

    Simoson, Andrew J.

    2009-01-01

    This article presents a fun activity of generating a double-minded fractal image for a linear algebra class once the idea of rotation and scaling matrices are introduced. In particular the fractal flip-flops between two words, depending on the level at which the image is viewed. (Contains 5 figures.)

  20. Biphoton double-slit experiment

    SciTech Connect

    Brida, G.; Cagliero, E.; Falzetta, G.; Genovese, M.; Gramegna, M.; Predazzi, E.

    2003-09-01

    In this paper we present a double-slit experiment where two indistinguishable photons produced by type-I parametric down-conversion are each sent to a well-defined slit. Data about the diffraction and interference patterns for coincidences are presented and discussed. An analysis of these data allows a test of standard quantum mechanics against the de Broglie-Bohm theory.

  1. A Double-Minded Fractal

    ERIC Educational Resources Information Center

    Simoson, Andrew J.

    2009-01-01

    This article presents a fun activity of generating a double-minded fractal image for a linear algebra class once the idea of rotation and scaling matrices are introduced. In particular the fractal flip-flops between two words, depending on the level at which the image is viewed. (Contains 5 figures.)

  2. Keepers of the double stars

    NASA Astrophysics Data System (ADS)

    Tenn, Joseph S.

    2013-03-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Early catalogues by the Herschels, Struves, and others began with their own discoveries. In 1906 court reporter and amateur astronomer Sherburne Wesley Burnham published a massive double star catalogue containing data from many observers on more than 13,000 systems. Lick Observatory astronomer Robert Grant Aitken produced a much larger catalogue in 1932 and coordinated with Robert Innes of Johannesburg, who catalogued the southern systems. Aitken maintained and expanded Burnham's records of observations on handwritten file cards, and eventually turned them over to the Lick Observatory, where astrometrist Hamilton Jeffers further expanded the collection and put all the observations on punched cards. With the aid of Frances M. "Rete" Greeby he made two catalogues: an Index Catalogue with basic data about each star, and a complete catalogue of observations, with one observation per punched card. He enlisted Willem van den Bos of Johannesburg to add southern stars, and together they published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers approached retirement he became greatly concerned about the disposition of the catalogues. He wanted to be replaced by another "double star man," but Lick Director Albert E. Whitford had the new 120-inch reflector, the world's second largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers was vociferously opposed to turning over the card files to another institution, and especially against their coming under the control of Kaj Strand of the United States Naval Observatory. In the end the USNO got the files and has maintained the records ever since, first under Charles Worley, and, since 1997, under Brian Mason. Now called the Washington Double Star Catalog (WDS), it is completely online and currently contains more than 1,200,000 measures of more than 125

  3. A laboratory investigation of potential double layers

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1987-01-01

    In a triple plasma device, the injection of electron current from the source chamber to the target chamber causes the formation of a potential double layer. At a low current density, the space charge of the injected current produces a virtual cathode-type potential double layer. This double layer is stable, and various wave instabilities are observed to associate with this double layer. As the current density is increased, the double layer becomes unstable, and a moving double layer results. As the current density is increased further, the enhanced ionization causes the neutralization of the space charge of the electron beam, and the beam plasma discharge is ignited.

  4. A laboratory investigation of potential double layers

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1987-01-01

    In a triple plasma device, the injection of electron current from the source chamber to the target chamber causes the formation of a potential double layer. At a low current density, the space charge of the injected current produces a virtual cathode-type potential double layer. This double layer is stable and various wave instabilities are observed to associate with this double layer. As the current density is increased, the double layer becomes unstable and a moving double layer results. As the current density is increased further, the enhanced ionization causes the neutralization of the space charge of the electron beam and the 'beam plasma discharge' is ignited.

  5. A laboratory investigation of potential double layers

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1987-01-01

    In a triple plasma device, the injection of electron current from the source chamber to the target chamber causes the formation of a potential double layer. At a low current density, the space charge of the injected current produces a virtual cathode-type potential double layer. This double layer is stable and various wave instabilities are observed to associate with this double layer. As the current density is increased, the double layer becomes unstable and a moving double layer results. As the current density is increased further, the enhanced ionization causes the neutralization of the space charge of the electron beam and the 'beam plasma discharge' is ignited.

  6. Double Photoionization into Double Core-Hole States in Xe

    SciTech Connect

    Hikosaka, Y.; Kaneyasu, T.; Shigemasa, E.; Lablanquie, P.; Penent, F.; Eland, J. H. D.; Aoto, T.; Ito, K.

    2007-05-04

    Double photoionization (DPI) leading to double core-hole states of Xe{sup 2+} 4d{sup -2} has been studied using a magnetic bottle time-of-flight spectrometer. The assignments of the Xe{sup 2+} 4d{sup -2} states are confirmed by the Auger lines extracted from fourfold coincidences including two photoelectrons and two Auger electrons. It is estimated that the core-core DPI into Xe{sup 2+} 4d{sup -2} at a photon energy of 301.6 eV has a favored cross section of about 0.3 MB. The intense core-core DPI is due to mixing of the 4d{sup -2} continuum with the 4p single photoionization, which is manifested in the relative intensities of the Xe{sup 2+} 4d{sup -2} components.

  7. Pathways to doubled haploidy: chromosome doubling during androgenesis.

    PubMed

    Seguí-Simarro, J M; Nuez, F

    2008-01-01

    Production of doubled haploid (DH) plants through androgenesis induction is a promising and convenient alternative to conventional selfing techniques for the generation of pure lines for breeding programs. This process comprises two main steps: induction of androgenesis and duplication of the haploid genome. Such duplication is sometimes indirectly induced by the treatments used to promote androgenic development. But usually, an additional step of direct chromosome doubling must be included in the protocol. Duplication of the haploid genome of androgenic individuals has been thought to occur through three mechanisms: endoreduplication, nuclear fusion and c-mitosis. In this review we will revise and analyze the evidences supporting each of the proposed mechanisms and their relevance during androgenesis induction, embryo/callus development and plant regeneration. Special attention will be devoted to nuclear fusion, whose evidences are accumulating in the last years.

  8. Double Standard/Double Bind: The Sexual Double Standard and Women's Communication about Sex.

    ERIC Educational Resources Information Center

    Muehlenhard, Charlene L.; McCoy, Marcia L.

    1991-01-01

    College women (n=403) attending the University of Kansas (Lawrence) commented on situations of refusal of desire for sexual relations when they actually did want them (scripted refusal). Consistent with theories of proximal determinants of gender-related behavior, scripted refusal provides a way of dealing with the sexual double standard. (SLD)

  9. Double layers and double wells in arbitrary degenerate plasmas

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2016-06-01

    Using the generalized hydrodynamic model, the possibility of variety of large amplitude nonlinear excitations is examined in electron-ion plasma with arbitrary electron degeneracy considering also the ion temperature effect. A new energy-density relation is proposed for plasmas with arbitrary electron degeneracy which reduces to the classical Boltzmann and quantum Thomas-Fermi counterparts in the extreme limits. The pseudopotential method is employed to find the criteria for existence of nonlinear structures such as solitons, periodic nonlinear structures, and double-layers for different cases of adiabatic and isothermal ion fluids for a whole range of normalized electron chemical potential, η0, ranging from dilute classical to completely degenerate electron fluids. It is observed that there is a Mach-speed gap in which no large amplitude localized or periodic nonlinear excitations can propagate in the plasma under consideration. It is further revealed that the plasma under investigation supports propagation of double-wells and double-layers the chemical potential and Mach number ranges of which are studied in terms of other plasma parameters. The Mach number criteria for nonlinear waves are shown to significantly differ for cases of classical with η0 < 0 and quantum with η0 > 0 regimes. It is also shown that the localized structure propagation criteria possess significant dissimilarities for plasmas with adiabatic and isothermal ions. Current research may be generalized to study the nonlinear structures in plasma containing positrons, multiple ions with different charge states, and charged dust grains.

  10. Double layers and double wells in arbitrary degenerate plasmas

    SciTech Connect

    Akbari-Moghanjoughi, M.

    2016-06-15

    Using the generalized hydrodynamic model, the possibility of variety of large amplitude nonlinear excitations is examined in electron-ion plasma with arbitrary electron degeneracy considering also the ion temperature effect. A new energy-density relation is proposed for plasmas with arbitrary electron degeneracy which reduces to the classical Boltzmann and quantum Thomas-Fermi counterparts in the extreme limits. The pseudopotential method is employed to find the criteria for existence of nonlinear structures such as solitons, periodic nonlinear structures, and double-layers for different cases of adiabatic and isothermal ion fluids for a whole range of normalized electron chemical potential, η{sub 0}, ranging from dilute classical to completely degenerate electron fluids. It is observed that there is a Mach-speed gap in which no large amplitude localized or periodic nonlinear excitations can propagate in the plasma under consideration. It is further revealed that the plasma under investigation supports propagation of double-wells and double-layers the chemical potential and Mach number ranges of which are studied in terms of other plasma parameters. The Mach number criteria for nonlinear waves are shown to significantly differ for cases of classical with η{sub 0} < 0 and quantum with η{sub 0} > 0 regimes. It is also shown that the localized structure propagation criteria possess significant dissimilarities for plasmas with adiabatic and isothermal ions. Current research may be generalized to study the nonlinear structures in plasma containing positrons, multiple ions with different charge states, and charged dust grains.

  11. Hierarchy in a double braneworld

    SciTech Connect

    Guerrero, Rommel; Rodriguez, R. Omar; Melfo, Alejandra; Pantoja, Nelson

    2006-10-15

    We show that the hierarchy between the Planck and the weak scales can follow from the tendency of gravitons and fermions to localize at different edges of a thick double wall embedded in an AdS{sub 5} spacetime without reflection symmetry. This double wall is a stable BPS thick-wall solution with two subwalls located at its edges; fermions are coupled to the scalar field through Yukawa interactions, but the lack of reflection symmetry forces them to be localized in one of the subwalls. We show that the graviton zero-mode wave function is suppressed in the fermion edge by an exponential function of the distance between the subwalls, and that the massive modes decouple so that Newtonian gravity is recuperated.

  12. Double agency in clinical research.

    PubMed

    Edwards, Marie; Chalmers, Karen

    2002-06-01

    The current focus on evidence-based practice in nursing may result in nurses playing 2 roles concurrently--that is, acting as researcher and caregiver at the same time and with the same people. Given the fiduciary nature of the patient-caregiver relationship, this double agency can give rise to problems, both real and perceived. In this paper, the issues associated with assuming dual roles in research with humans will be examined, particularly in relation to recruitment and informed consent, data collection, and participant withdrawal from a study. In addition, strategies to prevent or minimize problems related to double agency are identified, with attention to the guidance provided by professional codes of ethics and the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans.

  13. Neuberger's double-pass algorithm

    NASA Astrophysics Data System (ADS)

    Chiu, Ting-Wai; Hsieh, Tung-Han

    2003-12-01

    We analyze Neuberger’s double-pass algorithm for the matrix-vector multiplication R(H)ṡY [where R(H) is (n-1,n)th degree rational polynomial of positive definite operator H], and show that the number of floating-point operations is independent of the degree n, provided that the number of sites is much larger than the number of iterations in the conjugate gradient. This implies that the matrix-vector product (H)-1/2Y≃R(n-1,n)(H)ṡY can be approximated to very high precision with sufficiently large n, without noticeably extra costs. Further, we show that there exists a threshold nT such that the double-pass is faster than the single pass for n>nT, where nT≃12 25 for most platforms.

  14. Minimal Doubling and Point Splitting

    SciTech Connect

    Creutz, M.

    2010-06-14

    Minimally-doubled chiral fermions have the unusual property of a single local field creating two fermionic species. Spreading the field over hypercubes allows construction of combinations that isolate specific modes. Combining these fields into bilinears produces meson fields of specific quantum numbers. Minimally-doubled fermion actions present the possibility of fast simulations while maintaining one exact chiral symmetry. They do, however, introduce some peculiar aspects. An explicit breaking of hyper-cubic symmetry allows additional counter-terms to appear in the renormalization. While a single field creates two different species, spreading this field over nearby sites allows isolation of specific states and the construction of physical meson operators. Finally, lattice artifacts break isospin and give two of the three pseudoscalar mesons an additional contribution to their mass. Depending on the sign of this mass splitting, one can either have a traditional Goldstone pseudoscalar meson or a parity breaking Aoki-like phase.

  15. Edwards syndrome with double trisomy.

    PubMed

    Tennakoon, J; Kandasamy, Y; Alcock, G; Koh, T H

    2008-07-01

    Double trisomy is rare and the only case reported in the literature died soon after birth. We present another case of double trisomy (48XYY, +18) in a male neonate, who was born to a 28-year-old gravida three parity one mother at 35 weeks of gestation. The baby had features of trisomy 18. Karyotype of the patient showed 48, XYY, +18, Ish (DYZ3*2), (D18Z1*3), nuc ish (DYZ3*2), (D18Z1*3) . The patient had clinical features of trisomy 18. There was no family history of diabetes mellitus and no exposure to chemicals. It has been suggested that the rarity of Y-chromosome involvement in trisomy 18 may be due to discrepancy between the sexes.

  16. Double Negative Materials (DNM), Phenomena and Applications

    DTIC Science & Technology

    2009-07-01

    Nanoparticles Formed by Pairs Of Concentric Double-Negative (DNG), Single-Negative ( SNG ) and/or Double-Positive (DPS) Metamaterial Layers.” J. Appl...material RRL Rapid Research Letters SHG second-harmonic generation SNG single-negative SSR split-ring resonator A-1 Appendix A. October 2008...Pairs of Concentric Double-Negative (DNG), Single-Negative ( SNG ), and/or Double-Positive (DPS) Metamaterial Layers.” J. Appl. Phys. 97, no. 9 (May

  17. Current double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Giuliani, A.

    2005-01-01

    After an introduction about double beta decay and the deep connections between the lepton-violating channel and the neutrino properties, the most sensitive experimental approaches to the search for this rare nuclear transition are described. An overview of the experiments presently running is then given, with particular emphasis on the adopted techniques and their possible extrapolation to next-generation, higher-sensitivity experiments. The present situation about the experimental determination of the Majorana neutrino mass is presented and discussed.

  18. Double-Plate Penetration Equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    2000-01-01

    This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

  19. Revisiting double Dirac delta potential

    NASA Astrophysics Data System (ADS)

    Ahmed, Zafar; Kumar, Sachin; Sharma, Mayank; Sharma, Vibhu

    2016-07-01

    We study a general double Dirac delta potential to show that this is the simplest yet still versatile solvable potential to introduce double wells, avoided crossings, resonances and perfect transmission (T = 1). Perfect transmission energies turn out to be the critical property of symmetric and anti-symmetric cases wherein these discrete energies are found to correspond to the eigenvalues of a Dirac delta potential placed symmetrically between two rigid walls. For well(s) or barrier(s), perfect transmission (or zero reflectivity, R(E)) at energy E=0 is non-intuitive. However, this has been found earlier and called the ‘threshold anomaly’. Here we show that it is a critical phenomenon and we can have 0≤slant R(0)\\lt 1 when the parameters of the double delta potential satisfy an interesting condition. We also invoke a zero-energy and zero curvature eigenstate (\\psi (x)={Ax}+B) of the delta well between two symmetric rigid walls for R(0)=0. We resolve that the resonant energies and the perfect transmission energies are different and they arise differently.

  20. Double excitations in finite systems.

    PubMed

    Romaniello, P; Sangalli, D; Berger, J A; Sottile, F; Molinari, L G; Reining, L; Onida, G

    2009-01-28

    Time-dependent density-functional theory (TDDFT) is widely used in the study of linear response properties of finite systems. However, there are difficulties in properly describing excited states, which have double- and higher-excitation characters, which are particularly important in molecules with an open-shell ground state. These states would be described if the exact TDDFT kernel were used; however, within the adiabatic approximation to the exchange-correlation (xc) kernel, the calculated excitation energies have a strict single-excitation character and are fewer than the real ones. A frequency-dependent xc kernel could create extra poles in the response function, which would describe states with a multiple-excitation character. We introduce a frequency-dependent xc kernel, which can reproduce, within TDDFT, double excitations in finite systems. In order to achieve this, we use the Bethe-Salpeter equation with a dynamically screened Coulomb interaction W(omega), which can describe these excitations, and from this we obtain the xc kernel. Using a two-electron model system, we show that the frequency dependence of W does indeed introduce the double excitations that are instead absent in any static approximation of the electron-hole screening.

  1. Latest results from Double Chooz

    NASA Astrophysics Data System (ADS)

    Minotti, A.

    2017-01-01

    Double Chooz is a short-baseline neutrino disappearance experiment. It detects ν¯ e produced in the power plant of Chooz, France, where is located. The main goal of the experiment is the measurement of θ13 mixing angle and in 2011 for the first time the experiment observed an indication for a non zero value of such an oscillation parameter. The mixing angle was successively measured using only the far detector finding the best fit value of sin2(2θ13) = 0.090 -0.029 +0.032 . The near detector is under construction and will start data taking by the middle of 2014 allowing the reduction of the systematic errors. In this paper I make a review of the Double Chooz experiment, focusing in particular on the latest results of the measurement of the mixing angle θ13 relying on the neutron absorption on Gadolinium. I also present results proving the capability of Double Chooz to identify the ortho-positronium. This has been done in an event-by-event basis for the first time in a large liquid scintillator experiments, and can be an additional handle for the electron/positron discrimination in future detectors based on such technology.

  2. Pair extended coupled cluster doubles

    SciTech Connect

    Henderson, Thomas M.; Scuseria, Gustavo E.; Bulik, Ireneusz W.

    2015-06-07

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreover, pECCD yields sensible albeit inexact results even for attractive interactions where pCCD breaks down.

  3. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  4. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... Standards for Grades of Bermuda-Granex-Grano Type Onions Definitions § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  5. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  6. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  7. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  8. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... Standards for Grades of Bermuda-Granex-Grano Type Onions Definitions § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  9. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  10. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  11. Heat generation in double layer capacitors

    NASA Astrophysics Data System (ADS)

    Schiffer, Julia; Linzen, Dirk; Sauer, Dirk Uwe

    Thermal management is a key issue concerning lifetime and performance of double layer capacitors and battery technologies. Double layer capacitor modules for hybrid vehicles are subject to heavy duty cycling conditions and therefore significant heat generation occurs. High temperature causes accelerated aging of the double layer capacitors and hence reduced lifetime. To investigate the thermal behavior of double layer capacitors, thermal measurements during charge/discharge cycles were performed. These measurements show that heat generation in double layer capacitors is the superposition of an irreversible Joule heat generation and a reversible heat generation caused by a change in entropy. A mathematical representation of both parts is provided.

  12. Simulation of plasma double-layer structures

    NASA Technical Reports Server (NTRS)

    Borovsky, J. E.; Joyce, G.

    1982-01-01

    Electrostatic plasma double layers are numerically simulated by means of a magnetized 2 1/2 dimensional particle in cell method. The investigation of planar double layers indicates that these one dimensional potential structures are susceptible to periodic disruption by instabilities in the low potential plasmas. Only a slight increase in the double layer thickness with an increase in its obliqueness to the magnetic field is observed. Weak magnetization results in the double layer electric field alignment of accelerated particles and strong magnetization results in their magnetic field alignment. The numerical simulations of spatially periodic two dimensional double layers also exhibit cyclical instability. A morphological invariance in two dimensional double layers with respect to the degree of magnetization implies that the potential structures scale with Debye lengths rather than with gyroradii. Electron beam excited electrostatic electron cyclotron waves and (ion beam driven) solitary waves are present in the plasmas adjacent to the double layers.

  13. Enhanced nonlinear susceptibility via double-double electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Alotaibi, Hessa M. M.; Sanders, Barry C.

    2016-11-01

    We investigate the nonlinear optical susceptibility of an alkali-metal atom with tripod electronic configuration responsible for generating cross-phase modulation and self-phase modulation under the condition of double-double electromagnetically induced transparency. Our investigation demonstrates an enhancement in the nonlinear optical susceptibility of an alkali-metal atom by a factor of 1000 in the region of the second transparency window. This enhancement is in comparison with the atom's susceptibility in the first transparency window for the same parameters under the same conditions. Nonlinear-absorption enhancement arises by canceling Raman-gain generation, which arises when the probe and signal fields have equal intensities. At the center of the second transparency window, we obtain the condition required to attain a nonvanishing nonlinear optical susceptibility. In the bare-state picture, the coupling field must be off resonant from a bare-to-bare-state transition, while working in the semiclassical dressed picture required the signal field to be tuned off resonantly with a bare-to-dressed-state transition. The relation that governs the values of coupling- and signal-field detuning are also obtained. Our scheme exhibits the fact that the second transparency window has advantages over the first transparency window with respect to obtaining an enhanced Kerr effect, and our calculation includes simulation of both low-temperature and Doppler-broadened regimes.

  14. New insight on double-double radio galaxies

    NASA Astrophysics Data System (ADS)

    Nandi, Sumana

    2016-07-01

    Striking examples of episodic jet activity in active galactic nuclei (AGN) are the double-double radio galaxies (DDRGs) with two pairs of lobes emerging from the same central engine. The number of DDRGs reported so far is very limited, and it is important to identify more of these to provide a significant statistical overview of the conditions to trigger the jets and the role of jets in terms of feedback mechanisms that affect the host galaxies. Although most DDRGs were believed initially to be giant radio sources with sizes more than a Mpc, a significant number of smaller sized candidate DDRGs have also been identified in our recent study. We started GMRT observation of this sample to confirm that the sources are related to distinct epochs of nuclear activity. In addition to this radio observation we have also investigated the properties of the host galaxies and their environments to understand the triggering mechanisms for recurrent jet emission. Here, I will highlight the main results from these observations and discuss on the possible scenarios responsible for the episodic activity in different types of DDRGs .

  15. Proton-deuteron double scattering

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1974-01-01

    A simple but accurate form for the proton-deuteron elastic double scattering amplitude, which includes both projectile and target recoil motion and is applicable at all momentum transfer, is derived by taking advantage of the restricted range of Fermi momentum allowed by the deuteron wave function. This amplitude can be directly compared to approximations which have neglected target recoil or are limited to small momentum transfer; the target recoil and large momentum transfer effects are evaluated explicitly within the context of a Gaussian model.

  16. Double window viewing chamber assembly

    NASA Technical Reports Server (NTRS)

    Keller, V. W. (Inventor); Owen, R. B. (Inventor); Elkins, B. R. (Inventor); White, W. T. (Inventor)

    1986-01-01

    A viewing chamber which permits observation of a sample retained therein includes a pair of double window assemblies mounted in opposed openings in the walls thereof so that a light beam can directly enter and exit from the chamber. A flexible mounting arrangement for the outer windows of the window assemblies enables the windows to be brought into proper alignment. An electrical heating arrangement prevents fogging of the outer windows whereas desiccated air in the volume between the outer and inner windows prevents fogging of the latter.

  17. Semiconductor double quantum dot micromaser.

    PubMed

    Liu, Y-Y; Stehlik, J; Eichler, C; Gullans, M J; Taylor, J M; Petta, J R

    2015-01-16

    The coherent generation of light, from masers to lasers, relies upon the specific structure of the individual emitters that lead to gain. Devices operating as lasers in the few-emitter limit provide opportunities for understanding quantum coherent phenomena, from terahertz sources to quantum communication. Here we demonstrate a maser that is driven by single-electron tunneling events. Semiconductor double quantum dots (DQDs) serve as a gain medium and are placed inside a high-quality factor microwave cavity. We verify maser action by comparing the statistics of the emitted microwave field above and below the maser threshold. Copyright © 2015, American Association for the Advancement of Science.

  18. Booster Double Harmonic Setup Notes

    SciTech Connect

    Gardner, C. J.

    2015-02-17

    The motivation behind implementing a booster double harmonic include the reduced transverse space charge force from a reduced peak beam current and reduced momentum spread of the beam, both of which can be achieved from flattening the RF bucket. RF capture and acceleration of polarized protons (PP) is first set up in the single harmonic mode with RF harmonic h=1. Once capture and acceleration have been set up in the single harmonic mode, the second harmonic system is brought on and programmed to operate in concert with the single harmonic system.

  19. Double-Front Detonation Waves

    NASA Astrophysics Data System (ADS)

    Gubin, S. A.; Sumskoi, S. I.; Victorov, S. B.

    According to the theory of detonation, in a detonation wave there is a sound plane, named Chapman-Jouguet (CJ) plane. There are certain stationary parameters for this plane. In this work the possibility of the second CJ plane is shown. This second CJ plane is stationary as well. The physical mechanism of non-equilibrium transition providing the existence of the second CJ plane is presented. There is a non-equilibrium state, when the heat is removed from the reaction zone and the heat capacity decreases sharply. As a result of this non-equilibrium state, the sound velocity increases, and the local supersonic zone with second sonic plane (second CJ plane) appears. So the new mode of detonation wave is predicted. Equations describing this mode of detonation are presented. The exact analytical solution for the second CJ plane parameters is obtained. The example of double-front detonation in high explosive (TNT) is presented. In this double-front structure "nanodiamond-nanographite" phase transition takes place in condensed particles of detonation products.

  20. ATHLETE : Double Auger Anchoring Mechanism

    NASA Technical Reports Server (NTRS)

    Shin, Joseph

    2011-01-01

    The All-Terrain Hex-Legged Extra-Terrestrial Explorer (ATHLETE) is a six-limbed robot designed to support surface explorations on Near Earth Objects, the Moon and Mars. ATHLETE can carry large payloads on its top deck and can carry a fully equipped pressurized habitat in low gravity. The robot has wheels on each of its six articulated limbs, allowing it to actively conform to terrain while driving and to walk when driving is impractical. With the use of a tool adapter, ATHLETE limbs can be equipped with end effectors to support various mission objectives. For work on Near Earth Objects and other microgravity environments, an anchoring mechanism is needed to keep the ATHLETE from floating off the surface. My goal for this spring session at JPL was to design and build a counter rotating, double auger, anchoring mechanism. The mechanism mates to the tool adapter and is driven off the wheel motor. The double auger anchoring mechanism will be tested in a regolith simulant that will determine the uplift capacity of the anchoring mechanism.

  1. Double Photoionization of Atomic Beryllium

    NASA Astrophysics Data System (ADS)

    Yip, Frank L.; McCurdy, C. William; Rescigno, Thomas N.

    2010-03-01

    One-photon double ionization (DPI) of beryllium represents the next step in the evolution of DPI investigations that began with helium in order to sensitively probe electron correlation. Beryllium is the simplest atomic species of the alkaline earth elements which, in general, possess two electrons outside of a fully occupied inner shell that spherically screens the nucleus. This provides a natural basis for comparison to 1s^2 helium DPI. However, the valence state of beryllium has n=2, thus making the valence excited target 2s2p more accessible relative to the 2s^2 ground state as compared to ground-state and metastable helium. Also, the symmetry of photoionizing from either the ^1S or ^1P initial state will have consequences for the angular distributions for double ionization. Triply differential cross sections (TDCS) are presented for DPI from both ground state 2s^2 and excited state 2s2p beryllium calculated using exterior complex scaling (ECS) for the valence electrons.

  2. Double Standards in Global Health

    PubMed Central

    Admay, Catherine; Shakow, Aaron; Keshavjee, Salmaan

    2016-01-01

    Abstract The human rights arguments that underpinned the fight against HIV over the last three decades were poised, but ultimately failed, to provide a similar foundation for success against multidrug-resistant TB (MDR-TB) and other diseases of the poor. With more than 1.5 million deaths since 2000 attributed to strains of MDR-TB, and with half a million new, and mostly untreated, MDR-TB cases in the world each year, the stakes could not be higher. The World Health Organization (WHO), whose mandate is to champion the attainment by all peoples of the highest possible level of health, recommended unsound medical treatment for MDR-TB patients in resource-poor settings from 1993-2002. Citing cost considerations, WHO did not recommend the available standard of care that had been successfully used to contain and defeat MDR-TB in rich countries. By acting as a strategic gatekeeper in its technical advisory role to donor agencies and countries, it also facilitated the global implementation of a double standard for TB care in low- and middle-income countries (LMICs), upending important legal and scientific priorities. This raises serious questions about whether the organization violated international human rights standards and those established in its own constitution. While calling for additional analysis and discussion on this topic, the authors propose that policymakers should reject double standards of this kind and instead embrace the challenge of implementing the highest standard of care on a global level. PMID:27781001

  3. ATHLETE : Double Auger Anchoring Mechanism

    NASA Technical Reports Server (NTRS)

    Shin, Joseph

    2011-01-01

    The All-Terrain Hex-Legged Extra-Terrestrial Explorer (ATHLETE) is a six-limbed robot designed to support surface explorations on Near Earth Objects, the Moon and Mars. ATHLETE can carry large payloads on its top deck and can carry a fully equipped pressurized habitat in low gravity. The robot has wheels on each of its six articulated limbs, allowing it to actively conform to terrain while driving and to walk when driving is impractical. With the use of a tool adapter, ATHLETE limbs can be equipped with end effectors to support various mission objectives. For work on Near Earth Objects and other microgravity environments, an anchoring mechanism is needed to keep the ATHLETE from floating off the surface. My goal for this spring session at JPL was to design and build a counter rotating, double auger, anchoring mechanism. The mechanism mates to the tool adapter and is driven off the wheel motor. The double auger anchoring mechanism will be tested in a regolith simulant that will determine the uplift capacity of the anchoring mechanism.

  4. Vesicles with a double bilayer.

    PubMed

    Zawada, Zygmunt H

    2004-01-01

    A modified reverse phase evaporation method was used to prepare intermediate unilamellar vesicles coated with an additional membrane, or large vesicles in which several vesicles were coated with a common membrane. In both kinds of vesicle, the outer and inner membranes are usually of different phospholipid composition. The preparation involves the formation of a double emulsion: vesicles in a buffer are emerged in a low-boiling point organic solution of phospholipids. Then the organic solvent is evaporated during the heating and mixing process. As result large unilamellar vesicles (LUVs), about 100 nm in diameter, were coated with an additional membrane from egg lecithin or dipalmitoylphosphatidylcholine and cholesterol. The highest yield of the coating was about 50%. When DPPC was used for coating above the phase transition temperature Tm, the data suggested the formation of vesicles that were slightly larger than the starting LUVs. It might be concluded that many of these had a double bilayer. If the coating was done below Tm, the micrographs suggested the formation of structures resembling multi-vesicular vesicles. They looked like LUV clusters coated with a common membrane.

  5. Double-diffusive layer formation

    NASA Astrophysics Data System (ADS)

    Zaussinger, Florian; Kupka, Friedrich; Hücker, Sebastian; Egbers, Christoph

    2015-04-01

    Double-diffusive convection plays an important role in geo- and astrophysical applications. The special case, where a destabilising temperature gradient counteracts a stabilising solute gradient leads to layering phenomena under certain conditions. Convectively mixed layers sandwiched in diffusive interfaces form a so-called stack. Well-known double-diffusive systems are observed in rift lakes in Africa and even from the coffee drink Latte Macciatto. Stacks of layers are also predicted to occur inside massive stars and inside giant planets. Their dynamics depend on the thermal, the solute and the momentum diffusivities, as well on the ratio of the gradients of the opposing stratifications. Since the layering process cannot be derived from linear stability analysis, the full nonlinear set of equations has to be investigated. Numerical simulations have become feasible for this task, despite the physical processes operate on a vast range of length and time scales, which is challenging for numerical hydrodynamical modelling. The oceanographically relevant case of fresh and salty water is investigated here in further details. The heat and mass transfer is compared with theoretical results and experimental measurements. Additionally, the initial dynamic of layering, the transient behaviour of a stack and the long time evolution are presented using the example of Lake Kivu and the interior of a giant planet.

  6. Infinite sets and double binds.

    PubMed

    Arden, M

    1984-01-01

    There have been many attempts to bring psychoanalytical theory up to date. This paper approaches the problem by discussing the work of Gregory Bateson and Ignacio Matte-Blanco, with particular reference to the use made by these authors of Russell's theory of logical types. Bateson's theory of the double bind and Matte-Blanco's bilogic are both based on concepts of logical typing. It is argued that the two theories can be linked by the idea that neurotic symptoms are based on category errors in thinking. Clinical material is presented from the analysis of a middle-aged woman. The intention is to demonstrate that the process of making interpretations can be thought of as revealing errors in thinking. Changes in the patient's inner world are then seen to be the result of clarifying childhood experiences based on category errors. Matte-Blanco's theory of bilogic and infinite experiences is a re-evaluation of the place of the primary process in mental life. It is suggested that a combination of bilogic and double bind theory provides a possibility of reformulating psychoanalytical theory.

  7. Double Exposure: Photographing Climate Change

    NASA Astrophysics Data System (ADS)

    Arnold, D. P.; Wake, C. P.; Romanow, G. B.

    2008-12-01

    Double Exposure, Photographing Climate Change, is a fine-art photography exhibition that examines climate change through the prism of melting glaciers. The photographs are twinned shots of glaciers, taken in the mid-20th century by world-renowned photographer Brad Washburn, and in the past two years by Boston journalist/photographer David Arnold. Arnold flew in Washburn's aerial "footprints", replicating stunning black and white photographs, and documenting one irreversible aspect of climate change. Double Exposure is art with a purpose. It is designed to educate, alarm and inspire its audiences. Its power lies in its beauty and the shocking changes it has captured through a camera lens. The interpretive text, guided by numerous experts in the fields of glaciology, global warming and geology, helps convey the message that climate change has already forced permanent changes on the face of our planet. The traveling exhibit premiered at Boston's Museum of Science in April and is now criss-crossing the nation. The exhibit covers changes in the 15 glaciers that have been photographed as well as related information about global warming's effect on the planet today.

  8. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, Hannes

    1986-01-01

    As the rate of energy release in a double layer with voltage delta V is P approx I delta V, a double layer must be treated as a part of a circuit which delivers the current I. As neither double layer nor circuit can be derived from magnetofluid models of a plasma, such models are useless for treating energy transfer by means of double layers. They must be replaced by particle models and circuit theory. A simple circuit is suggested which is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object (one example is the double radio sources). It is tentatively suggested in X-ray and Gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). A study of how a number of the most used textbooks in astrophysics treat important concepts like double layers, critical velocity, pinch effects and circuits is made.

  9. Gender Double Standards in Parenting Attitudes*

    PubMed Central

    Axinn, William G.; Young-DeMarco, Linda; Ro, Meeso Caponi

    2010-01-01

    This paper investigates the double standard in attitudes toward courtship and family formation behaviors of sons and daughters. We argue there are strong theoretical reasons to expect that the magnitude of this double standard varies across substantive domains, as well as amongst parents and non-parents. We also argue key methodological limitations of previous studies likely produce an under-estimate of the gender double standard. We provide empirical estimates of the gender double standard that overcome these limitations, including a random assignment experiment explicitly designed to control the effects of social desirability. These estimates demonstrate variability in the double standard across domains and reveal key factors contributing to the magnitude of the double standards in parenting attitudes held by individuals. PMID:21318125

  10. Double-Swivel Mechanism For Reliable Release

    NASA Technical Reports Server (NTRS)

    King, Guy L.; Schneider, William C.

    1990-01-01

    Double-swivel toggle mechanism releases large, heavy objects reliably. Double-swiveling action of mechanism ensures it clears restraining pins upon release. Pins retain toggle and its load. If pin fails to withdraw at designated time for releasing payload, toggle swivels about its upper ball, and ring swivels about lower ball so ring flange clears failed pin. Double-swivel action ensures disengagement even it two pins fail to withdraw.

  11. Constitutive Parameter Measurement Using Double Ridge Waveguide

    DTIC Science & Technology

    2013-03-01

    CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Nathan J. Lehman, Captain, USAF AFIT-ENG-13-M-30 DEPARTMENT OF THE AIR FORCE...copyright protection in the United States. AFIT-ENG-13-M-30 CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Presented to the Faculty...PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE Nathan J. Lehman, B.S.E.E. Captain, USAF Approved: Michael Havrilla, PhD (Chairman) Maj Milo Hyde, PhD

  12. Controlled double-slit electron diffraction

    NASA Astrophysics Data System (ADS)

    Bach, Roger; Pope, Damian; Liou, Sy-Hwang; Batelaan, Herman

    2013-03-01

    Double-slit diffraction is a corner stone of quantum mechanics. It illustrates key features of quantum mechanics: interference and the particle-wave duality of matter. In 1965, Richard Feynman presented a thought experiment to show these features. Here we demonstrate the full realization of his famous thought experiment. By placing a movable mask in front of a double-slit to control the transmission through the individual slits, probability distributions for single- and double-slit arrangements were observed. Also, by recording single electron detection events diffracting through a double-slit, a diffraction pattern was built up from individual events.

  13. Change of coagulation parameters after double plateletpheresis.

    PubMed

    Yilmaz, Mustafa; Dikmen, Tamer; Sonmez, Mehmet; Akdogan, Elif; Durmus, Ahmet; Omay, Serdar Bedii; Ovali, Ercument

    2007-10-01

    In the previous studies, some authors reported that automated apheresis leads to a hypercoagulable state. We tried to find out changes in coagulation parameters after double plateletpheresis in this study. Forty-five donors were recruited to the study, and coagulation parameters were assessed before and after double plateletpheresis. After double plateletpheresis, fibrinogen, factor V, factor VIII and factor IX were decreased compared with the values before apheresis. Although serum levels of this coagulation parameters are decreasing, they are still in the normal limits. Therefore, we suggest that double plateletpheresis is a safe procedure for healthy volunteers taking into account these coagulation parameters.

  14. The efficiency of tennis doubles scoring systems.

    PubMed

    Pollard, Geoff; Pollard, Graham

    2010-01-01

    In this paper a family of scoring systems for tennis doubles for testing the hypothesis that pair A is better than pair B versus the alternative hypothesis that pair B is better than A, is established. This family or benchmark of scoring systems can be used as a benchmark against which the efficiency of any doubles scoring system can be assessed. Thus, the formula for the efficiency of any doubles scoring system is derived. As in tennis singles, one scoring system based on the play-the-loser structure is shown to be more efficient than the benchmark systems. An expression for the relative efficiency of two doubles scoring systems is derived. Thus, the relative efficiency of the various scoring systems presently used in doubles can be assessed. The methods of this paper can be extended to a match between two teams of 2, 4, 8, …doubles pairs, so that it is possible to establish a measure for the relative efficiency of the various systems used for tennis contests between teams of players. Key pointsA relatively straightforward expression or formula for the efficiency of a tennis doubles scoring system has been established.The expression for the relative efficiency of two tennis doubles scoring systems is a simple one, and is the same as that for two singles scoring systems.The methodology of this paper can be used and extended so that the efficiency of a scoring system for a match between two teams of doubles pairs can be measured.

  15. Double photoionization of halogenated benzene

    SciTech Connect

    AlKhaldi, Mashaal Q.; Wehlitz, Ralf

    2016-01-28

    We have experimentally investigated the double-photoionization process in C{sub 6}BrF{sub 5} using monochromatized synchrotron radiation. We compare our results with previously published data for partially deuterated benzene (C{sub 6}H{sub 3}D{sub 3}) over a wide range of photon energies from threshold to 270 eV. A broad resonance in the ratio of doubly to singly charged parent ions at about 65 eV appears shifted in energy compared to benzene data. This shift is due to the difference in the bond lengths in two molecules. A simple model can explain the shape of this resonance. At higher photon energies, we observe another broad resonance that can be explained as a second harmonic of the first resonance.

  16. Doubling bialgebras of rooted trees

    NASA Astrophysics Data System (ADS)

    Mohamed, Mohamed Belhaj; Manchon, Dominique

    2017-01-01

    The vector space spanned by rooted forests admits two graded bialgebra structures. The first is defined by Connes and Kreimer using admissible cuts, and the second is defined by Calaque, Ebrahimi-Fard and the second author using contraction of trees. In this article, we define the doubling of these two spaces. We construct two bialgebra structures on these spaces which are in interaction, as well as two related associative products obtained by dualization. We also show that these two bialgebras verify a commutative diagram similar to the diagram verified Calaque, Ebrahimi-Fard and the second author in the case of rooted trees Hopf algebra, and by the second author in the case of cycle-free oriented graphs.

  17. Double Compton scatter telescope calibration

    NASA Technical Reports Server (NTRS)

    Dayton, B.; Simone, J.; Green, M.; Long, J.; Zanrosso, E.; Zych, A. D.; White, R. S.

    1981-01-01

    Calibration techniques for a medium energy gamma ray telescope are described. Gain calibration using Compton edge spectra involves comparisons of pulse height spectra with spectra simulated by a Monte Carlo computer code which includes Compton scattering and pair production, plural scattering and variable energy resolution, and cell size. The telescope considered comprises 56 cells of liquid scintillator in four size groups, with a total liquid volume of 325 l; each cell has its own photomultiplier tube. Energy and angular resolutions and the PMT gain calibration procedure are verified with double scatter data for monoenergetic gamma rays at a known location. Detection probabilities for any cell combination in the two telescope arrays are calculated per steradian as a function of the scattering for a number of different energies with a Van de Graaff accelerator.

  18. Symmetrical double input coupler development

    SciTech Connect

    Deruyter, H.; Hoag, H.; Ko, K.; Ng, C.K.

    1992-08-01

    RF power is usually transmitted into an accelerator section from a rectangular waveguide through a single coupling iris. This arrangement introduces phase and amplitude asymmetries into the coupler fields with which the beam interacts. Field distortion can be reduced by machining an offset into the cavity wall opposite the iris. However, the compensation is imperfect. In this paper we describe the development and testing of a double input coupler which is completely symmetric about a vertical plane through the beam axis. Two identical irises are used on opposite sides of the coupler cavity. These are fed in-phase by signals from a Magic Tee power divider. Each iris transmits one half of the total power flow. Coupler dimensions for an X-Band model have been optimized using MAFIA and conventional low-power matching techniques. The coupler has been built into a 30-cavity test accelerator section and operated up to 85 MV/m with no evidence of breakdown.

  19. William Doberck - double star astronomer

    NASA Astrophysics Data System (ADS)

    MacKeown, P. Kevin

    2007-03-01

    We outline the role of astronomy in the career of William Doberck (1852-1941). After taking a PhD in astronomy at the University of Jena in 1873, he accepted a position as superintendent of Markree Observatory in the west of Ireland. There he refurbished the great 13-inch refractor and spent nine years observing mostly double star systems, paying only such attention to meteorological monitoring as was required of his position. In 1883 he became the founding Director of a new observatory in Hong Kong, a post which he held for 24 years. His frustrations in attempting to continue his purely astronomical work, not assuaged by his combative and prickly personality, and in the face of the strictly practical demands of that mercantile society for comprehensive storm forecasting, are described. Finally, his observations in retirement in England, and his overall contribution to astronomy, are summarised.

  20. Indirect double photoionization of water

    NASA Astrophysics Data System (ADS)

    Resccigno, T. N.; Sann, H.; Orel, A. E.; Dörner, R.

    2011-05-01

    The vertical double ionization thresholds of small molecules generally lie above the dissociation limits corresponding to formation of two singly charged fragments. This gives the possibility of populating singly charged molecular ions by photoionization in the Franck-Condon region at energies below the lowest dication state, but above the dissociation limit into two singly charged fragment ions. This process can produce a superexcited neutral fragment that autoionizes at large internuclear separation. We study this process in water, where absorption of a photon produces an inner-shell excited state of H2O+ that fragments to H++OH*. The angular distribution of secondary electrons produced by OH* when it autoionizes produces a characteristic asymmetric pattern that reveals the distance, and therefore the time, at which the decay takes place. LBNL, Berkeley, CA, J. W. Goethe Universität, Frankfurt, Germany. Work performed under auspices of US DOE and supported by OBES, Div. of Chemical Sciences.

  1. Double Compton scatter telescope calibration

    NASA Technical Reports Server (NTRS)

    Dayton, B.; Simone, J.; Green, M.; Long, J.; Zanrosso, E.; Zych, A. D.; White, R. S.

    1981-01-01

    Calibration techniques for a medium energy gamma ray telescope are described. Gain calibration using Compton edge spectra involves comparisons of pulse height spectra with spectra simulated by a Monte Carlo computer code which includes Compton scattering and pair production, plural scattering and variable energy resolution, and cell size. The telescope considered comprises 56 cells of liquid scintillator in four size groups, with a total liquid volume of 325 l; each cell has its own photomultiplier tube. Energy and angular resolutions and the PMT gain calibration procedure are verified with double scatter data for monoenergetic gamma rays at a known location. Detection probabilities for any cell combination in the two telescope arrays are calculated per steradian as a function of the scattering for a number of different energies with a Van de Graaff accelerator.

  2. Extended organic-inorganic hybrids based on Dawson and double-Dawson-type polyoxometalates.

    PubMed

    Zhang, Zhiming; Li, Yangguang; Wang, Yonghui; Qi, Yanfei; Wang, Enbo

    2008-09-01

    The reaction between K 12[H 2P 2W 12O 48] and CuCl 2 in a NaCl aqueous solution assisted with organoamines (1,2-ethylenediamine (en), 1,6-hexamethylene diamine (hn), or both) leads to the isolation of three compounds: K 4Na 10[alpha 1-CuP 2W 17O 60(OH)] 2. approximately 58H 2O ( 1), Na 2[H 2en][H 2hn] 0.5[Cu(en) 2] 4.5[alpha 1-CuP 2W 17O 60(OH)] 2. approximately 43H 2O ( 2), and Na 3[H 2hn] 2.5[alpha 1-P 2W 17O 60Cu(OH) 2]. approximately 14H 2O ( 3). The polyoxoanion [alpha 1-CuP 2W 17O 60(OH)] 2 (14-) in 1 and 2 exhibits a double-Dawson-type polyoxoanion that consists of two alpha 1-type mono-Cu-substituted WellsDawson anions, which can be synthesized by both the conventional aqueous solution method and the hydrothermal technique. Furthermore, the double-Dawson-type polyoxoanions in 2 are linked by the [Cu(en) 2] (2+) bridges to form 2-D networks, which are further packed into a 3-D supramolecular porous framework via extensive hydrogen bonding interactions, exhibiting two types of tunnels (A and B). Compound 3 possesses a 3-D supramolecular framework with 1-D tunnels constructed from the alpha 1-type mono-Cu-substituted WellsDawson anion. The magnetic studies of compounds 1 and 2 indicate that weak antiferromagnetic interactions exist in these two compounds.

  3. The Doubling Moment: Resurrecting Edgar Allan Poe

    ERIC Educational Resources Information Center

    Minnick, J. Bradley; Mergil, Fernando

    2008-01-01

    This article expands upon Jeffrey Wilhelm's and Brian Edmiston's (1998) concept of a doubling of viewpoints by encouraging middle level students to use dramatization to take on multiple perspectives, to pose interpretive questions, and to enhance critical inquiry from inside and outside of texts. The doubling moment is both the activation of…

  4. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, William C.

    1988-01-01

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached.

  5. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, W.C.

    1988-10-11

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached. 8 figs.

  6. The Doubling Moment: Resurrecting Edgar Allan Poe

    ERIC Educational Resources Information Center

    Minnick, J. Bradley; Mergil, Fernando

    2008-01-01

    This article expands upon Jeffrey Wilhelm's and Brian Edmiston's (1998) concept of a doubling of viewpoints by encouraging middle level students to use dramatization to take on multiple perspectives, to pose interpretive questions, and to enhance critical inquiry from inside and outside of texts. The doubling moment is both the activation of…

  7. Mapping the double-slit diffraction pattern

    NASA Astrophysics Data System (ADS)

    Selvaggi, Richard; Rogers, Charles; Richardson, Clay

    2010-10-01

    A red laser, movable double-slit, movable micrometer mounted single-slit light block, and CCD were utilized to map out the single and double-slit diffraction patterns between 0 and 30 millimeters. The three dimensional mapping results demonstrate that the double-slit troughs similarly redirect the electromagnetic energy and light particles. The measured alternating path of the electromagnetic energy and light particles in the double-slit diffraction pattern is different than the theoretic path of light waves defined by destructive interference and indicates that theoretical light waves do not always have electromagnetic energy. George Monk's 1937 and Richard Feynman's 1964 finding of conservation of electromagnetic energy in the double-slit light experiment present the following questions: 1) What are the mass-less and energy-less destructive interference light waves found in the double-slit troughs? 2) What force is applied to and what energy is consumed by the work of redistributing the electromagnetic energy and light particles in the double-slit diffraction pattern? 3) Is this unknown force and unknown energy the result of dark matter found in the double-slit troughs?

  8. Electric fields and double layers in plasmas

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra; Thiemann, H.; Schunk, R. W.

    1987-01-01

    Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamical features of the double layers are discussed. These features, as seen in simulations, laboratory experiments, and theory, indicate that double layers and the currents through them undergo slow oscillations which are determined by the ion transit time across an effective length of the system in which double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations were considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields and double layers in an expanding plasma is discussed.

  9. Intrateam Communication and Performance in Doubles Tennis

    ERIC Educational Resources Information Center

    Lausic, Domagoj; Tennebaum, Gershon; Eccles, David; Jeong, Allan; Johnson, Tristan

    2009-01-01

    Verbal and nonverbal communication is a critical mediator of performance in team sports and yet there is little extant research in sports that involves direct measures of communication. Our study explored communication within NCAA Division I female tennis doubles teams. Video and audio recordings of players during doubles tennis matches captured…

  10. Electron temperature differences and double layers

    NASA Technical Reports Server (NTRS)

    Chan, C.; Hershkowitz, N.; Lonngren, K. E.

    1983-01-01

    Electron temperature differences across plasma double layers are studied experimentally. It is shown that the temperature differences across a double layer can be varied and are not a result of thermalization of the bump-on-tail distribution. The implications of these results for electron thermal energy transport in laser-pellet and tandem-mirror experiments are also discussed.

  11. Perspective: Double Jeopardy--Another Look.

    ERIC Educational Resources Information Center

    Bolduan, Linda M.; Dailey, Dianne K.

    1997-01-01

    Explores how a defendant can face a civil action and criminal prosecution for the same act without violating the principle of double jeopardy. For instance, burning down a house can engender criminal prosecution charges and a civil suit from the insurance company. Double jeopardy only applies to criminal actions. (MJP)

  12. Islets of stability beyond period doubling

    SciTech Connect

    Mackay, R.S.

    1981-11-01

    Period doubling of a periodic orbit of an area preserving map appears to lead to the elimination of all closed invariant curves in the vicinity. We show, however, that there are always islets of stabilhty again beyond the accumulation point of the period doubling sequence.

  13. An interesting prenatal diagnosis: double aneuploidy.

    PubMed

    Aydin, Cetin; Eris, Serenat; Yalcin, Yakup; Sen Selim, Halime

    2013-01-01

    Double aneuploidy, the existence of two chromosomal abnormalities in the same individual, is a rare condition. Early diagnosis of this condition is important to offer termination of pregnancy in genetic counselling. Cytogenetic analysis with amniocentesis and ultrasound examination is valuable for diagnosis of double aneuploidy. In this report we present a case with the karyotype of 48XXY+21 diagnosed prenatally.

  14. Photometry of Faint Wide Doubles in Hydra

    NASA Astrophysics Data System (ADS)

    Knapp, Wilfried; Thuemen, Chris; Gould, Ross

    2015-11-01

    Images of several double stars in Hydra published on the "Double Star Imaging Project" Yahoo Group page suggest magnitude issues compared with the corresponding WDS catalog data per end of 2014. Taking additional images with V and B filters enabled photometry for these pairs, suggesting significant corrections to the old data in WDS.

  15. The Sexual Double Standard: How Prevalent Today?

    ERIC Educational Resources Information Center

    Sack, Alan R.; And Others

    1981-01-01

    Studied the sexual double standard among university students. Females showed a stronger association between premarital intercourse and affection and perceived less approval from five reference groups for their sexual behavior than did males. Results indicate the sexual double standard is still evident among the present group of college students.…

  16. Electric fields and double layers in plasmas

    NASA Astrophysics Data System (ADS)

    Singh, Nagendra; Thiemann, H.; Schunk, R. W.

    1987-05-01

    Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamical features of the double layers are discussed. These features, as seen in simulations, laboratory experiments, and theory, indicate that double layers and the currents through them undergo slow oscillations which are determined by the ion transit time across an effective length of the system in which double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations were considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields and double layers in an expanding plasma is discussed.

  17. Double Prosecution of the State University Student

    ERIC Educational Resources Information Center

    Kelly, Thomas E., Jr.

    1974-01-01

    Explores whether the state university student confronted with double prosecution (university disciplinary proceedings and state or municipal criminal proceedings) has any constitutional basis for claiming the applicability of double jeopardy protection of the Fifth Amendment as a bar to a second prosecution. Concludes that the issue is not…

  18. Intrateam Communication and Performance in Doubles Tennis

    ERIC Educational Resources Information Center

    Lausic, Domagoj; Tennebaum, Gershon; Eccles, David; Jeong, Allan; Johnson, Tristan

    2009-01-01

    Verbal and nonverbal communication is a critical mediator of performance in team sports and yet there is little extant research in sports that involves direct measures of communication. Our study explored communication within NCAA Division I female tennis doubles teams. Video and audio recordings of players during doubles tennis matches captured…

  19. 7 CFR 3560.460 - Double damages.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Double damages. 3560.460 Section 3560.460 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE... Actions § 3560.460 Double damages. (a) Action to recover assets or income. (1) The Agency may request to...

  20. Self-Frequency-Doubling Ytterbium Lasers

    NASA Astrophysics Data System (ADS)

    Dawes, Judith M.; Dekker, Peter; Burns, Philip; Piper, James A.

    2005-03-01

    Ytterbium-doped self-frequency-doubling lasers offer high efficiency, tunable, visible and near-infrared, cw and pulsed operation from compact devices. We review the performance of ytterbium-doped yttrium aluminium borate (Yb:YAB) self-frequency-doubling lasers. Because of the detailed dynaMisc of the interaction of the nonlinear pulse shaping process for mode-locking or for Q-switching self-frequency-doubled lasers, we observe pulse lengthening in each process when frequency doubling is optimised, with high average output power. However, for continuous wave operation, the self-frequency doubling process may be optimised to give highly efficient, robust, widely-tunable output in the visible as well as fundamental output in the infrared.

  1. Reliability Estimation for Double Containment Piping

    SciTech Connect

    L. Cadwallader; T. Pinna

    2012-08-01

    Double walled or double containment piping is considered for use in the ITER international project and other next-generation fusion device designs to provide an extra barrier for tritium gas and other radioactive materials. The extra barrier improves confinement of these materials and enhances safety of the facility. This paper describes some of the design challenges in designing double containment piping systems. There is also a brief review of a few operating experiences of double walled piping used with hazardous chemicals in different industries. This paper recommends approaches for the reliability analyst to use to quantify leakage from a double containment piping system in conceptual and more advanced designs. The paper also cites quantitative data that can be used to support such reliability analyses.

  2. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, H.

    1986-01-01

    A simple circuit is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object. It is suggested that X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). The way the most used textbooks in astrophysics treat concepts like double layers, critical velocity, pinch effects and circuits was studied. It is found that students using these textbooks remain essentially ignorant of even the existence of these, although some of the phenomena were discovered 50 yr ago.

  3. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, Hannes

    1986-01-01

    A simple circuit is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from earth. Double layers in space should be classified as a new type of celestial object. It is suggested that X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). The way the most used textbooks in astrophysics treat concepts like double layers, critical velocity, pinch effects and circuits was studied. It is found that students using these textbooks remain essentially ignorant of even the existence of these, although some of the phenomena were discovered 50 yr ago.

  4. Instability limits for spontaneous double layer formation

    SciTech Connect

    Carr, J. Jr.; Galante, M. E.; McCarren, D.; Scime, E. E.; Sears, S.; VanDervort, R. W.; Magee, R. M.; Reynolds, E.

    2013-11-15

    We present time-resolved measurements that demonstrate that large amplitude electrostatic instabilities appear in pulsed, expanding helicon plasmas at the same time as particularly strong double layers appear in the expansion region. A significant cross-correlation between the electrostatic fluctuations and fluctuations in the number of ions accelerated by the double layer electric field is observed. No correlation is observed between the electrostatic fluctuations and ions that have not passed through the double layer. These measurements confirm that the simultaneous appearance of the electrostatic fluctuations and the double layer is not simple coincidence. In fact, the accelerated ion population is responsible for the growth of the instability. The double layer strength, and therefore, the velocity of the accelerated ions, is limited by the appearance of the electrostatic instability.

  5. Double-patterning-friendly OPC

    NASA Astrophysics Data System (ADS)

    Li, Xiaohai; Luk-Pat, Gerry; Cork, Chris; Barnes, Levi; Lucas, Kevin

    2009-03-01

    Double patterning technology (DPT) is one of the main options for printing critical layers at 32nm half-pitch and beyond. To enable DPT, a layout decomposition tool is first used to split the original design into two separate decomposed-design layouts. Each decomposed-design layout may then receive optical proximity correction (OPC) and RETs to produce a mask layout. The requirements for OPC to enable individual layer DPT patterning are generally the same as current single exposure OPC requirements, meaning that the success criteria will be similar to previous node specifications. However, there are several new challenges for OPC with DPT. These include large litho-etch biases, two sets of process variables associated with each patterning layer and the relative pattern placement between them. The order of patterning may be important as there may be process interactions between the two patterns especially at overlap regions. Corners which were rounded in single patterning layers may now become sharp, potentially increasing reliability concerns due to electromigration. In this study, we address many of these issues by proposing several new techniques that can be used in OPC with DPT. They are specifically designed for the Litho-Etch-Litho-Etch process, but some of the ideas may be extended to develop OPC methods for other DPT processes. We applied the new OPC method to several circuit and test patterns and demonstrated how OPC results were improved compared to regular OPC methods.

  6. Double-disc gate valve

    DOEpatents

    Wheatley, Seth J.

    1979-01-01

    This invention relates to an improvement in a conventional double-disc gate valve having a vertically movable gate assembly including a wedge, spreaders slidably engaged therewtih, a valve disc carried by the spreaders. When the gate assembly is lowered to a selected point in the valve casing, the valve discs are moved transversely outward to close inlet and outlet ports in the casing. The valve includes hold-down means for guiding the disc-and-spreader assemblies as they are moved transversely outward and inward. If such valves are operated at relatively high differential pressures, they sometimes jam during opening. Such jamming has been a problem for many years in gate valves used in gaseous diffusion plants for the separtion of uranium isotopes. The invention is based on the finding that the above-mentioned jamming results when the outlet disc tilts about its horizontal axis in a certain way during opening of the valve. In accordance with the invention, tilting of the outlet disc is maintained at a tolerable value by providing the disc with a rigid downwardly extending member and by providing the casing with a stop for limiting inward arcuate movement of the member to a preselected value during opening of the valve.

  7. Ultra-relativistic double explosions

    NASA Astrophysics Data System (ADS)

    Lyutikov, Maxim

    2017-04-01

    We consider fluid dynamics of relativistic double explosion—when a point explosion with energy E1 is followed by a second explosion with energy E2 after time td (the second explosion could be in a form of a long lasting wind). The primary explosion creates a self-similar relativistic blast wave propagating with Lorentz factor Γ1(t ) . A sufficiently strong second explosion, with total energy E2≥10-2E1 , creates a fast second shock in the external fluid previously shocked by the primary shock. At times longer than the interval between the explosions td, yet short compared with the time when the second shock catches up the primary shock at ˜tdΓ12 , the structure of the second shock is approximately self-similar. The self-similar structure of the second shock exists for the case of constant external density (in this case Γ2∝t-7 /3 ), but not for the wind environment. At early times, the Lorentz factor of the second shock may exceed that of the primary shock and may boost the synchrotron emission of locally accelerated electrons into the Fermi Large Area Telescope range.

  8. Double-sided Relativistic Magnetron

    NASA Astrophysics Data System (ADS)

    Agafonov, A. V.; Krastelev, E. G.

    1997-05-01

    A new scheme of a symmetricaly powered relativistic magnetron and several methods of localised electron flow forming in an interaction region are proposed to increase an efficiency of relativistic magnetrons. As will be shown, a very important reason is the effect of nonsymmetric feeding of power from one side of a magnetron, which is typical for experiments. One-sided powering leads to the axial drift of electrons, to the transformation of transverse velocities of electrons to longitudinal one and to the generation of a parasitic e-beam which does not take part in energy exchange between electrons and waves at all. A special driver was designed for double-sided powering of relativistic magnetrons. The proposed system is compact, rigid and capable of reliable operation at high repetition rates, which is advantageous for many applications. Several smooth-bore magnetrons were tested by means of computer simulations using PIC code KARAT. The results showed a dramatical difference between the dynamics of electron flow for one- and two-sided power feeding of a structure under test. Design of a driver and computer simulation results are presented.

  9. 77 FR 6606 - DoubleLine Capital LP and DoubleLine Funds Trust; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... by or under common control with DoubleLine (any such adviser or DoubleLine, an ``Adviser''); \\1\\ (ii... COMMISSION DoubleLine Capital LP and DoubleLine Funds Trust; Notice of Application February 2, 2012. AGENCY... relying on rule 12d1-2 under the Act to invest in certain financial instruments. APPLICANTS: DoubleLine...

  10. The double-dark portal

    NASA Astrophysics Data System (ADS)

    Curtin, David; Tsai, Yuhsin

    2014-11-01

    In most models of the dark sector, dark matter is charged under some new symmetry to make it stable. We explore the possibility that not just dark matter, but also the force carrier connecting it to the visible sector is charged under this symmetry. This dark mediator then acts as a Double-Dark Portal. We realize this setup in the dark mediator Dark matter model (dmDM), featuring a fermionic DM candidate χ with Yukawa couplings to light scalars ϕ i . The scalars couple to SM quarks via the operator . This can lead to large direct detection signals via the 2 → 3 process χ N → χ N ϕ if one of the scalars has mass ≲ 10 keV. For dark matter Yukawa couplings y χ ˜ 10-3 -10-2, dmDM features a thermal relic dark matter candidate while also implementing the SIDM scenario for ameliorating inconsistencies between dwarf galaxy simulations and observations. We undertake the first systematic survey of constraints on light scalars coupled to the SM via the above operator. The strongest constraints are derived from a detailed examination of the light mediator's effects on stellar astrophysics. LHC experiments and cosmological considerations also yield important bounds. Observations of neutron star cooling exclude the minimal model with one dark mediator, but a scenario with two dark mediators remains viable and can give strong direct detection signals. We explore the direct detection consequences of this scenario and find that a heavy dmDM candidate fakes different WIMPs at different experiments. Large regions of dmDM parameter space are accessible above the irreducible neutrino background.

  11. Double Asteroid Redirection Test (DART)

    NASA Astrophysics Data System (ADS)

    Cheng, A. F.

    2016-12-01

    The Asteroid Impact Deflection Assessment (AIDA) mission will be the first space experiment to demonstrate asteroid impact hazard mitigation by using a kinetic impactor. AIDA is a joint ESA-NASA cooperative project, consisting of the NASA Double Asteroid Redirection Test (DART) kinetic impactor mission and the ESA Asteroid Impact Mission (AIM) which is the rendezvous spacecraft. The AIDA target is the near-Earth binary asteroid 65803 Didymos. During the Didymos close approach to Earth in October, 2022, the DART spacecraft will impact the Didymos secondary at 6 km/s and deflect its trajectory, changing the orbital period of the binary. This change can be measured by Earth-based optical and radar observations. The primary goals of AIDA are to (1) perform a full-scale demonstration of asteroid deflection by kinetic impact; (2) measure the resulting deflection; and (3) validate and improve models for momentum transfer in high-speed impacts on an asteroid. The combined DART and AIM missions will provide the first measurements of momentum transfer efficiency from a kinetic impact at full scale on an asteroid, where the impact conditions of the projectile are known, and physical properties and internal structures of the target asteroid are also characterized. In addition to a measurable change in the binary orbit period, the DART kinetic impact is predicted to induce forced librations of the Didymos secondary of up to several degrees amplitude. It will furthermore make a crater that will be studied in detail by the AIM spacecraft, and it will release a volume of particulate ejecta that may be directly observable from Earth or even resolvable as a coma or an ejecta tail by ground-based telescopes. Updates will be given on DART status and study results.

  12. Earthquakes with non--double-couple mechanisms.

    PubMed

    Frohlich, C

    1994-05-06

    Seismological observations confirm that the pattern of seismic waves from some earthquakes cannot be produced by slip along a planar fault surface. More than one physical mechanism is required to explain the observed varieties of these non-double-couple earthquakes. The simplest explanation is that some earthquakes are complex, with stress released on two or more suitably oriented, nonparallel fault surfaces. However, some shallow earthquakes in volcanic and geothermal areas require other explanations. Current research focuses on whether fault complexity explains most observed non-double-couple earthquakes and to what extent ordinary earthquakes have non-double-couple components.

  13. Vacuum leak detection for double bottom tanks

    SciTech Connect

    Hagen, T.; Rials, R.

    1995-12-31

    Double bottom tanks offer strong leak detection advantages. By incorporating the use of vacuum detection between the two bottoms, the tank bottoms can be verified leak free after construction and during tank use. Utilizing vacuum leak detection requires special considerations. In 1992 a tank construction company built 10 tanks for an oil company in Ponca City, Oklahoma. Each of these tanks were built with a double bottom. This paper provides insight into the planning, construction and testing of this type of double bottom design.

  14. Double-reed exhaust valve engine

    DOEpatents

    Bennett, Charles L.

    2015-06-30

    An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a double reed outlet valve for controlling the flow of low-pressure working fluid out of the engine. The double reed provides a stronger force resisting closure of the outlet valve than the force tending to open the outlet valve. The double reed valve enables engine operation at relatively higher torque and lower efficiency at low speed, with lower torque, but higher efficiency at high speed.

  15. Use double-containment piping systems

    SciTech Connect

    Hollis, P. )

    1994-06-01

    Double-containment piping systems are one of the most reliable ways of protecting against primary piping leaks of corrosive or hazardous fluids. In their early years, double containment systems were prohibitively expensive for all but the most extreme applications. Today the cost of reliable double-containment systems has fallen, while the quality and reliability are generally high. A combination of government regulations, fear of litigation, and concerned management has resulted in rapid growth of these piping systems. The paper discusses EPA regulations, design considerations, materials, pressure ratings, flexibility analysis, containment pipe analysis, stress analysis, leak detection, serviceability, cost, and design codes.

  16. Double layers on auroral field lines

    NASA Technical Reports Server (NTRS)

    Hudson, M. K.; Lotko, W.; Witt, E.

    1982-01-01

    Time-stationary solutions to the Vlasov-Poisson equation for ion holes and double layers were examined along with particle simulations which pertain to recent observations of small amplitude (e phi)/t sub e approx. 1 electric field structures on auroral field lines. Both the time-stationary analysis and the simulations suggest that double layers evolve from holes in ion phase space when their amplitude reaches (e phi)/t sub e approx. 1. Multiple small amplitude double layers which are seen in long simulation systems and are seen to propagate past spacecraft may account for the acceleration of plasma sheet electrons to produce the discrete aurora.

  17. Development of double-decker pulse radiolysis.

    PubMed

    Kan, K; Kondoh, T; Yang, J; Ogata, A; Norizawa, K; Yoshida, Y

    2012-07-01

    Double-decker pulse radiolysis (DDPR), which utilizes double-decker electron beams, was investigated to develop a new pulse radiolysis with a high time resolution. The double-decker electron beams were generated by injecting two UV pulses into a photocathode radio-frequency gun. In the pulse radiolysis, one electron beam was used as a pump beam, and the other was converted to a probe pulse. Finally, as its first application, the DDPR was successfully used for observing solvated electrons in water, with a 10%-90% rise time of 8.6 ps.

  18. Materials Data on Na3Al2P2O8F3 (SG:36) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-05

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Materials Data on Al2P2H8C2NO8F (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on KCu2P2H3(O4F)2 (SG:12) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-23

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on Na3Ti2P2O10F (SG:42) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Materials Data on BaTi2(P2O7)2 (SG:15) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-02-10

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. Materials Data on Li5Mn2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. Materials Data on Na5Ni2P2(CO7)2 (SG:6) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. Materials Data on Li3Mn2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Materials Data on Na3Mn2P2(CO7)2 (SG:4) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  7. Materials Data on Li3Fe2P2(CO7)2 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  8. Materials Data on Li3Cr2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Materials Data on Na3Ni2P2(CO7)2 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Materials Data on Na5Ni2P2(CO7)2 (SG:11) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. Materials Data on Li3Fe2P2(CO7)2 (SG:4) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Materials Data on Li5Mn2P2(CO7)2 (SG:6) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  13. Materials Data on Na3Ni2P2(CO7)2 (SG:7) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  14. Materials Data on Li5Mn2P2(CO7)2 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Materials Data on Na3Mn2P2(CO7)2 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  16. Materials Data on Na5Ni2P2(CO7)2 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  17. Materials Data on Li3Fe2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. Materials Data on Na5Ni2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Materials Data on Na5Mn2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on Na3Ni2P2(CO7)2 (SG:4) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on Na3Mn2P2(CO7)2 (SG:7) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Materials Data on Na5Mn2P2(CO7)2 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. Materials Data on Li3Mn2P2(CO7)2 (SG:4) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. Materials Data on Na5Mn2P2(CO7)2 (SG:11) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. Materials Data on Na3Ni2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Materials Data on Na3Mn2P2(CO7)2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  7. Materials Data on SrFe2(P2O7)2 (SG:2) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  8. Design of a Sensor-Blending Kalman Filter for the R2P2 Fine-Tracking System

    DTIC Science & Technology

    1990-03-01

    MANEUVER GATING............................... 20 A. MAHALANOBIS DISTANCE ................. ....... 20 B. RESIDUAL GATING...its bandwidth. This will be accomplished by adding maneuver gatirig to the Kalman filter. 19 IV. MANEUVER GATING A. MAHALANOBIS DISTANCE The...this procedure was derived from Reference 7. The Mahalanobis distance is found using the values for the residual and co- variance of the residual

  9. Cross sections for production of H(2p, 2s, 1s) by electron collisional dissociation of H2

    NASA Technical Reports Server (NTRS)

    Ajello, J. M.; James, G. K.; Shemansky, D. E.

    1991-01-01

    The excitation function of H Ly-alpha from the astrophysically important dissociation of electron-excited H2 over the range 10-700 eV has been measured. The analysis predicts the cross section to energies higher than the present experimental limit, and it is found that the predicted shape is in close agreement with measured results. At 6 eV the cross section is dominated by the electric dipole first Born component, while at 100 eV the electric dipole component constitutes 73 percent of the total H(2p) cross section. The cross sections of the H(2s) and H(1s) components are calculated.

  10. Materials Data on Ba2CaV2(P2O9)2 (SG:7) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-09-30

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. Materials Data on RbGa2P2H5O11 (SG:14) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-02-05

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Materials Data on SrV2(P2O7)2 (SG:2) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  13. Materials Data on MgB2P2H8O13 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-07-14

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  14. Materials Data on Na3Mn2P2(CO7)2 (SG:7) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Materials Data on Li3Fe2P2(CO7)2 (SG:7) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  16. Materials Data on Na3Ni2P2(CO7)2 (SG:7) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-22

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  17. Dry Eyes and Glaucoma: Double Trouble

    MedlinePlus

    ... News About Us Donate In This Section Dry Eyes and Glaucoma: Double Trouble email Send this article ... disease bothers the patient more. What Causes Dry Eye Syndrome? Dry eye can be caused by many ...

  18. Review of modern double beta decay experiments

    SciTech Connect

    Barabash, A. S.

    2015-10-28

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T{sub 1/2}(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino (〈m{sub ν}〉 < 0.46 eV) and a coupling constant of Majoron to neutrino (〈g{sub ee}〉 < 1.3 · 10{sup −5}) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to 〈m{sub ν}〉 at the level of ∼ 0.01-0.1 eV are discussed.

  19. Rosalind Franklin and the Double Helix

    NASA Astrophysics Data System (ADS)

    Elkin, Lynne Osman

    2003-03-01

    Although she made essential contributions toward elucidating the structure of DNA, Rosalind Franklin is known to many only as seen through the distorting lens of James Watson's book, The Double Helix.

  20. Frequency Doubling Broadband Light in Multiple Crystals

    SciTech Connect

    ALFORD,WILLIAM J.; SMITH,ARLEE V.

    2000-07-26

    The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth.

  1. Over-under double-pass interferometer

    NASA Technical Reports Server (NTRS)

    Schindler, R. A. (Inventor)

    1977-01-01

    An over-under double pass interferometer in which the beamsplitter area and thickness can be reduced to conform only with optical flatness considerations was achieved by offsetting the optical center line of one cat's-eye retroreflector relative to the optical center line of the other in order that one split beam be folded into a plane distinct from the other folded split beam. The beamsplitter is made transparent in one area for a first folded beam to be passed to a mirror for doubling back and is made totally reflective in another area for the second folded beam to be reflected to a mirror for doubling back. The two beams thus doubled back are combined in the central, beamsplitting area of the beamsplitting and passed to a detector. This makes the beamsplitter insensitive to minimum thickness requirements and selection of material.

  2. Novel technologies in doubled haploid line development.

    PubMed

    Ren, Jiaojiao; Wu, Penghao; Trampe, Benjamin; Tian, Xiaolong; Lübberstedt, Thomas; Chen, Shaojiang

    2017-08-10

    haploid inducer line can be transferred (DH) technology can not only shorten the breeding process but also increase genetic gain. Haploid induction and subsequent genome doubling are the two main steps required for DH technology. Haploids have been generated through the culture of immature male and female gametophytes, and through inter- and intraspecific via chromosome elimination. Here, we focus on haploidization via chromosome elimination, especially the recent advances in centromere-mediated haploidization. Once haploids have been induced, genome doubling is needed to produce DH lines. This study has proposed a new strategy to improve haploid genome doubling by combing haploids and minichromosome technology. With the progress in haploid induction and genome doubling methods, DH technology can facilitate reverse breeding, cytoplasmic male sterile (CMS) line production, gene stacking and a variety of other genetic analysis. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  3. Inverse solutions for tilting orthogonal double prisms.

    PubMed

    Li, Anhu; Ding, Ye; Bian, Yongming; Liu, Liren

    2014-06-10

    An analytical reverse solution and actual examples are given to show how to direct a laser beam from a pair of orthogonal prisms to given targets in free space. Considering the influences of double-prism structural parameters, a lookup table method to seek the numerical reverse solution of each prism's tilting angle is also proposed for steering the double-prism orientation to track a target position located in the near field. Some case studies, as well as a specified elliptical target trajectory scanned by the cam-based driving double prisms, exhibit the significant application values of the theoretical derivation. The analytic reverse and numerical solutions can be generalized to investigate the synthesis of scanning patterns and the controlling strategy of double-prism tilting motion, the potentials of which can be explored to perform the orientation and position tracking functions in applications of precision engineering fields.

  4. A High Power Frequency Doubled Fiber Laser

    NASA Technical Reports Server (NTRS)

    Thompson, Rob; Tu, Meirong; Aveline, Dave; Lundblad, Nathan; Maleki, Lute

    2003-01-01

    This slide presentation reviews the power frequencies for the doubled fiber laser. It includes information on the 780 nm laser, second harmonic generation in one crystal, cascading crystals, the tenability of laser systems, laser cooling, and directions for future work.

  5. A new hydrodynamic analysis of double layers

    NASA Technical Reports Server (NTRS)

    Hora, Heinrich

    1987-01-01

    A genuine two-fluid model of plasmas with collisions permits the calculation of dynamic (not necessarily static) electric fields and double layers inside of plasmas including oscillations and damping. For the first time a macroscopic model for coupling of electromagnetic and Langmuir waves was achieved with realistic damping. Starting points were laser-produced plasmas showing very high dynamic electric fields in nonlinear force-produced cavitous and inverted double layers in agreement with experiments. Applications for any inhomogeneous plasma as in laboratory or in astrophysical plasmas can then be followed up by a transparent hydrodynamic description. Results are the rotation of plasmas in magnetic fields and a new second harmonic resonance, explanation of the measured inverted double layers, explanation of the observed density-independent, second harmonics emission from laser-produced plasmas, and a laser acceleration scheme by the very high fields of the double layers.

  6. Improved double beam, vacuum far infrared spectrophotometer.

    PubMed

    Iwahashi, I; Matsumoto, K; Matsudaira, S; Minami, S; Yoshinaga, H

    1969-03-01

    A double beam far ir spectrophotometer was improved in order to give more convenience and higher performance. The instrument is evacuable and the sample chamber alone can also be purged with dry air to remove water vapor. Three photometric systems, i.e., conventional double beam, double beam double chopping, and single beam systems can be selected for versatile measurements. The use of an efficient transmission filter system, not involving deliquescent crystals, results in many operational advantages. Accordingly, high resolution can be obtained through the entire spectral region from 400 cm(-1) to 30 cm(-1) Moreover, 30-min scan over the entire spectral region is achieved by completely automatic operation with a refined control system.

  7. Over-under double-pass interferometer

    NASA Technical Reports Server (NTRS)

    Schindler, Rudolf A. (Inventor)

    1980-01-01

    An over-under double-pass interferometer in which the beamsplitter area and thickness can be reduced to conform only with optical flatness considerations is achieved by offsetting the optical center line of one cat's-eye retroreflector relative to the optical center line of the other in order that one split beam be folded into a plane distinct from the other folded split beam. The beamsplitter is made transparent in one area for a first folded beam to be passed to a mirror for doubling back and is made totally reflective in another area for the second folded beam to be reflected to a mirror for doubling back. The two beams thus doubled back are combined in the central, beam-splitting area of the beamsplitter and passed to a detector. This makes the beamsplitter insensitive to minimum-thickness requirements and selection of material.

  8. Nonlinear dynamics of a double bilipid membrane.

    PubMed

    Sample, C; Golovin, A A

    2007-09-01

    The nonlinear dynamics of a biological double membrane that consists of two coupled lipid bilayers, typical of some intracellular organelles such as mitochondria or nuclei, is studied. A phenomenological free-energy functional is formulated in which the curvatures of the two parts of the double membrane and the distance between them are coupled to the lipid chemical composition. The derived nonlinear evolution equations for the double-membrane dynamics are studied analytically and numerically. A linear stability analysis is performed, and the domains of parameters are found in which the double membrane is stable. For the parameter values corresponding to an unstable membrane, numerical simulations are performed that reveal various types of complex dynamics, including the formation of stationary, spatially periodic patterns.

  9. Double Power: English Literacy and Indigenous Education.

    ERIC Educational Resources Information Center

    Wignell, Peter, Ed.

    The collection of essays on the relationship between English literacy and indigenous education, particularly in the Australian context, includes: "Double Power" (Mandawuy Yunupingu); "History, Cultural Diversity & English Language Teaching" (Martin Nakata); "Scaffolding Reading and Writing for Indigenous Children in…

  10. A High Power Frequency Doubled Fiber Laser

    NASA Technical Reports Server (NTRS)

    Thompson, Rob; Tu, Meirong; Aveline, Dave; Lundblad, Nathan; Maleki, Lute

    2003-01-01

    This slide presentation reviews the power frequencies for the doubled fiber laser. It includes information on the 780 nm laser, second harmonic generation in one crystal, cascading crystals, the tenability of laser systems, laser cooling, and directions for future work.

  11. The Double Scene of Televised AIDS Campaigns.

    ERIC Educational Resources Information Center

    Cummings, Kate

    1992-01-01

    Analyzes the double or mirrored scene of the Centers for Disease Control's AIDS education campaign and the responses to that campaign, basically, the dominant, heterosexual, televised discourses' defensive erasure of those semiotic objects that represent illicit and nonreproductive sex. (RS)

  12. Double Shell Tank (DST) Transfer Valving Specification

    SciTech Connect

    GRAVES, C.E.

    2001-01-17

    This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied during design of the Double-Shell Tank (DST) Transfer Valving Subsystem that supports the first phase of Waste Feed Delivery.

  13. Don't Double Up on Acetaminophen

    MedlinePlus

    ... Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer Updates Don't Double ... products. January 24, 2013 back to top Related Consumer Updates Have a Baby or Young Child With ...

  14. Decay properties of double heavy baryons

    SciTech Connect

    Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery; Ivanov, Mikhail A.; Koerner, Juergen G.

    2010-08-05

    We study the semileptonic decays of double heavy baryons using a manifestly Lorentz covariant constituent three-quark model. We present complete results on transition form factors between double-heavy baryons for finite values of the heavy quark/baryon masses and in the heavy quark symmetry limit which is valid at and close to zero recoil. Decay rates are calculated and compared to each other in the full theory, keeping masses finite, and also in the heavy quark limit.

  15. Numerical simulations on ion acoustic double layers

    SciTech Connect

    Sato, T.; Okuda, H.

    1980-07-01

    A comprehensive numerical study of ion acoustic double layers has been performed for both periodic as well as for nonperiodic systems by means of one-dimensional particle simulations. For a nonperiodic system, an external battery and a resistance are used to model the magnetospheric convection potential and the ionospheric Pedersen resistance. It is found that the number of double layers and the associated potential buildup across the system increases with the system length.

  16. Wavelength-doubling optical parametric oscillator

    DOEpatents

    Armstrong, Darrell J.; Smith, Arlee V.

    2007-07-24

    A wavelength-doubling optical parametric oscillator (OPO) comprising a type II nonlinear optical medium for generating a pair of degenerate waves at twice a pump wavelength and a plurality of mirrors for rotating the polarization of one wave by 90 degrees to produce a wavelength-doubled beam with an increased output energy by coupling both of the degenerate waves out of the OPO cavity through the same output coupler following polarization rotation of one of the degenerate waves.

  17. Crack Propagation in Double-Base Propellants

    DTIC Science & Technology

    1976-01-01

    propagation tests were conducted on a composite modified double- base ( CMDB ) propellant with the use of center-cracked strip biaxial specimens...double-base ( CMDB ) propellant. He performed a stress analysis of small, precracked, subscale STV motors formulated in terms of stress intensity factors...assumed for Solithane 113. The present program was aimed at evaluating the Schapery theory when it was applied to a CMDB propellant under similar loading

  18. Robotic-assisted double-sleeve lobectomy

    PubMed Central

    Qiu, Tong; Zhao, Yandong; Xuan, Yunpeng

    2017-01-01

    Double-sleeve lobectomy, which includes bronchoplasty and pulmonary arterial angioplasty, is required for certain cases of central-type lung cancer. It is usually done by open surgery or video-assisted thoracoscopic surgery (VATS). In recently, da Vinci system and robotic surgery have been applied in such complicated cases. Here we describe the details associated with robotic-assisted double-sleeve lobectomy. PMID:28203433

  19. The HIPPARCOS Double and Multiple Star Solutions

    NASA Astrophysics Data System (ADS)

    Mignard, F.

    The Hipparcos catalogue provides general astrometric and photometric information on double and multiple stars in specific fields of the main catalogue and detailed data on the components in the various sections of a dedicated annex: the Double and Multiple Systems Annex (DMSA). Overall statistics of these solutions are presented for the 13,211 entries of this annex and the different types of solutions are outlined.

  20. Double shell tank waste analysis plan

    SciTech Connect

    Mulkey, C.H.; Jones, J.M.

    1994-12-15

    Waste analysis plan for the double shell tanks. SD-WM-EV-053 is Superseding SD-WM-EV-057.This document provides the plan for obtaining information needed for the safe waste handling and storage of waste in the Double Shell Tank Systems. In Particular it addresses analysis necessary to manage waste according to Washington Administrative Code 173-303 and Title 40, parts 264 and 265 of the Code of Federal Regulations.

  1. [Veterinary double-monsters historically viewed].

    PubMed

    Baljet, B; Heijke, G C

    1997-01-01

    A large number of duplication monstrosities have been observed in cattle, sheep, pigs, horses, goats, cats and dogs, ever since the publication of the famous woodcut of a swine double monster by J. S. Brant in Basel in 1496, better known as the "wunderbare Sau von Landser im Elsass". Albrecht Dürer also made a woodcut of this double monster in front of the village Landser in 1496. A picture of a deer double monster was published in 1603 by Heinrich Ulrich in Germany. In the monograph De monstrorum causis, natura et differentiis ..., published by the Italian Fortunius Licetus in 1616 pictures of double monsters being half man half dog are found. These fantasy figures have been popular for a long time and were supposed to be really in existence. Apart from these fantasy figures many pictures are known from real veterinary double monsters. U. Aldrovandus described in 1642 in his Monstrorum historia, besides many fantasy figures, also real human and veterinary double monsters and he gave also good pictures of them. In the 19th century examples of veterinary duplication monstrosities were published by I. Geoffroy Saint-Hilaire (1832-37), E. F. Gurlt (1832), W. Vrolik (1840) and C. Taruffi (1881); they proposed also concepts concerning the etiology. In the second volume of his famous handbook of teratology (1907), E. Schwalbe described many veterinary double monsters and discussed the theories of the genesis of congenital malformations. Various theories concerning the genesis of double monsters have been given since Aristotle (384-322 B.C.). ...

  2. How I treat double-hit lymphoma.

    PubMed

    Friedberg, Jonathan W

    2017-08-03

    The 2016 revision of the World Health Organization (WHO) classification for lymphoma has included a new category of lymphoma, separate from diffuse large B-cell lymphoma, termed high-grade B-cell lymphoma with translocations involving myc and bcl-2 or bcl-6. These lymphomas, which occur in <10% of cases of diffuse large B-cell lymphoma, have been referred to as double-hit lymphomas (or triple-hit lymphomas if all 3 rearrangements are present). It is important to differentiate these lymphomas from the larger group of double-expressor lymphomas, which have increased expression of MYC and BCL-2 and/or BCL-6 by immunohistochemistry, by using variable cutoff percentages to define positivity. Patients with double-hit lymphomas have a poor prognosis when treated with standard chemoimmunotherapy and have increased risk of central nervous system involvement and progression. Double-hit lymphomas may arise as a consequence of the transformation of the underlying indolent lymphoma. There are no published prospective trials in double-hit lymphoma, however retrospective studies strongly suggest that aggressive induction regimens may confer a superior outcome. In this article, I review my approach to the evaluation and treatment of double-hit lymphoma, with an eye toward future clinical trials incorporating rational targeted agents into the therapeutic armamentarium. © 2017 by The American Society of Hematology.

  3. Double peak sensory responses: effects of capsaicin.

    PubMed

    Aprile, I; Tonali, P; Stalberg, E; Di Stasio, E; Caliandro, P; Foschini, M; Vergili, G; Padua, L

    2007-10-01

    The aim of this study is to verify whether degeneration of skin receptors or intradermal nerve endings by topical application of capsaicin modifies the double peak response obtained by submaximal anodal stimulation. Five healthy volunteers topically applied capsaicin to the finger-tip of digit III (on the distal phalanx) four times daily for 4-5 weeks. Before and after local capsaicin applications, we studied the following electrophysiological findings: compound sensory action potential (CSAP), double peak response, sensory threshold and double peak stimulus intensity. Local capsaicin application causes disappearance or decrease of the second component of the double peak, which gradually increases after the suspension of capsaicin. Conversely, no significant differences were observed for CSAP, sensory threshold and double peak stimulus intensity. This study suggests that the second component of the double peak may be a diagnostic tool suitable to show an impairment of the extreme segments of sensory nerve fibres in distal sensory axonopathy in the early stages of damage, when receptors or skin nerve endings are impaired but undetectable by standard nerve conduction studies.

  4. Double infarction in one cerebral hemisphere.

    PubMed

    Bogousslavsky, J

    1991-07-01

    Thirty-two patients whose first stroke was due to double infarct in one cerebral hemisphere were identified among 1,911 consecutive patients from the Lausanne Stroke Registry. The double infarct involved territories of the superficial middle cerebral artery, superficial posterior cerebral artery, lenticulostriate, anterior choroidal artery, or borderzone. The most common combination involved territories of the anterior middle cerebral artery plus the posterior middle cerebral artery. In the patients with the double infarct, the prevalence of potential cardiac sources of embolism (19%) was similar to that found in the registry in general, but the double infarct was closely associated with tight (greater than or equal to 90% of the lumen diameter) stenosis or occlusion (75%) of the internal carotid artery. The most common neurological picture mimicked large infarction in the middle cerebral artery territory, but nearly half of the patients with double infarct in one cerebral hemisphere had a specific clinical syndrome, which was not found in the 1,879 remaining patients from the registry, including hemianopia-hemiplegia (in 6), acute conduction aphasia-hemiparesis (in 2), and acute transcortical mixed aphasia (in 6), in relation to characteristic combinations of infarcts. These unique clinical and etiological correlates warrant the recognition of double infarct in one cerebral hemisphere from other acute ischemic strokes.

  5. Fluid dynamics of double diffusive systems

    SciTech Connect

    Koseff, J.R.

    1989-04-07

    A study of mixing processes in doubly diffusive systems is being conducted. Continuous gradients of two diffusing components (heat and salinity in our case) are being used as initial conditions, and forcing is introduced by lateral heating and surface shear. The goals of the proposed work include: (1) quantification of the effects of finite amplitude disturbances on stable, double diffusive systems, particularly with respect to lateral heating, (2) development of an improved understanding of the physical phenomena present in wind-driven shear flows in double diffusive stratified environments, (3) increasing our knowledge-base on turbulent flow in stratified environments and how to represent it, and (4) formulation of a numerical code for such flows. The work is being carried out in an experimental facility which is located in the Stanford Environmental Fluid Mechanics Laboratory, and on laboratory minicomputers and CRAY computers. In particular we are focusing on the following key issues: (1) the formation and propagation of double diffusive intrusions away from a heated wall and the effects of lateral heating on the double diffusive system; (2) the interaction between the double diffusively influenced fluxes and the turbulence induced fluxes; (3) the measurement of heat and mass fluxes; and (4) the influence of double diffusive gradients on mixed layer deepening. 1 fig.

  6. The Design and its Verification of the Double Rotor Double Cage Induction Motor

    NASA Astrophysics Data System (ADS)

    Sinha, Sumita; Deb, Nirmal K.; Biswas, Sujit K.

    2017-02-01

    The concept of a double rotor motor presented earlier and its equivalent circuit has been developed, showing a non-linear parameter content. The two rotors (which are recommended to be double cage type for development of high starting torque) can run with equal or unequal speed independently, depending on their individual loading. This paper presents the elaborate design procedure, step-by-step, for the double rotor double cage motor and verifies the designed data with that obtained from three separate tests (compared to two for conventional motor) on a prototype, such that optimum performance can be obtained from the motor.

  7. Overlay metrology for double patterning processes

    NASA Astrophysics Data System (ADS)

    Leray, Philippe; Cheng, Shaunee; Laidler, David; Kandel, Daniel; Adel, Mike; Dinu, Berta; Polli, Marco; Vasconi, Mauro; Salski, Bartlomiej

    2009-03-01

    The double patterning (DPT) process is foreseen by the industry to be the main solution for the 32 nm technology node and even beyond. Meanwhile process compatibility has to be maintained and the performance of overlay metrology has to improve. To achieve this for Image Based Overlay (IBO), usually the optics of overlay tools are improved. It was also demonstrated that these requirements are achievable with a Diffraction Based Overlay (DBO) technique named SCOLTM [1]. In addition, we believe that overlay measurements with respect to a reference grid are required to achieve the required overlay control [2]. This induces at least a three-fold increase in the number of measurements (2 for double patterned layers to the reference grid and 1 between the double patterned layers). The requirements of process compatibility, enhanced performance and large number of measurements make the choice of overlay metrology for DPT very challenging. In this work we use different flavors of the standard overlay metrology technique (IBO) as well as the new technique (SCOL) to address these three requirements. The compatibility of the corresponding overlay targets with double patterning processes (Litho-Etch-Litho-Etch (LELE); Litho-Freeze-Litho-Etch (LFLE), Spacer defined) is tested. The process impact on different target types is discussed (CD bias LELE, Contrast for LFLE). We compare the standard imaging overlay metrology with non-standard imaging techniques dedicated to double patterning processes (multilayer imaging targets allowing one overlay target instead of three, very small imaging targets). In addition to standard designs already discussed [1], we investigate SCOL target designs specific to double patterning processes. The feedback to the scanner is determined using the different techniques. The final overlay results obtained are compared accordingly. We conclude with the pros and cons of each technique and suggest the optimal metrology strategy for overlay control in double

  8. Chen’s Double Eyelid Fold Ratio

    PubMed Central

    Chen, Chen-Chia; Tai, Hao-Chih

    2016-01-01

    Background: Double eyelidplasty can construct palpebral folds and enhance beauty perception for Asians with single eyelids. A new palpebral parameter for the quantitative interpretation of surgical outcomes is proposed on the basis of a photometric study of the altered proportions of Asian eyes after double eyelid operation. Methods: A total of 100 Asian adults with single upper eyelids who were satisfied with the enlarged eyes by operation were included in the study. A retrospective measurement of palpebral parameters in the frontal profile both preoperatively and 6 months postoperatively was performed. The proportions of various parameters in the eyebrow–eye aesthetic unit were calculated and analyzed. Results: Double eyelidplasty can augment the vertical dimension of palpebral fissure by 27.9% increase on average. The vertical ratio of palpebral fissure to the eyebrow–eye unit is augmented by 34.4% increase. The vertical ratio of the subunit below double eyelid fold peak to the unit is augmented by 82.6% increase. Conclusions: Double eyelidplasty can substantially enlarge the vertical dimensions of the eyes of Asians with single eyelids. The eyes are perceived to be larger because of the visually assimilated illusion of the superimposed eyelid fold and the relative proportions of the eyebrow–eye unit. The authors propose using a vertical ratio of the subunit below double eyelid fold peak in the eyebrow–eye unit to measure the visually perceived proportion of the eye in the unit. This ratio can be applied clinically for a quantitative evaluation of the surgical outcome after double eyelidplasty. PMID:27200243

  9. The First SLR Double-Difference Baseline

    NASA Astrophysics Data System (ADS)

    Svehla, Drazen; Haagmans, Roger; Floberghagen, Rune; Cacciapuoti, Luigi; Sierk, Bernd; Kirchner, Georg; Rodriguez, Jose; Wilkinson, Matthew; Sherwood, Rob; Appleby, Graham

    2013-04-01

    We introduce the SLR double-difference approach of space geodesy. With real and simulated SLR measurements it is shown how common SLR biases are removed by forming SLR double-differences, i.e. station range biases, common retro-reflector effects and orbit errors (GNSS) for baselines up to e.g. 5000 km. In this way we obtain SLR observables of utmost precision and accuracy. We show how remaining noise in the SLR measurements nicely averages out, leading to orbit-free and bias-free estimation of station coordinates, local ties between different space geodesy techniques and precise comparison of optical/microwave tropospheric effects. It shall be noted that SLR scale is preserved by double-differencing. When ETALON and LAGEOS satellites are observed by SLR, any orbit error propagates directly into estimated station coordinates. However, by forming differences between two satellites and two ground stations this orbit error can be eliminated. Both satellites need to be observed quasi-simultaneously in the same tracking sessions in order that station range bias and common retro-reflector effects are removed by differencing. When SLR measurements from GRZL and HERL SLR stations are taken to GLONASS and LAGEOS satellites and processed in double-difference mode, clear common orbit errors are visible in the SLR residuals from both stations. The same stands for small range biases that are visible between the consecutive observing sessions and are removed by forming SLR baselines. Longer SLR passes reveal other interesting systematic effects common to both stations at mm-level. An error in the order of 4-6 cm RMS was introduced to GNSS orbits, however the effect on station coordinates in negligible over such a short SLR baseline. We show how with just one-two SLR double-difference passes one can estimate station coordinates at mm-level. When in parallel, both GNSS satellites are observed with microwave measurements, one can estimate very accurate local ties by comparing (or

  10. Double Engine for a Nebula

    NASA Astrophysics Data System (ADS)

    2009-08-01

    ESO has just released a stunning new image of a field of stars towards the constellation of Carina (the Keel). This striking view is ablaze with a flurry of stars of all colours and brightnesses, some of which are seen against a backdrop of clouds of dust and gas. One unusual star in the middle, HD 87643, has been extensively studied with several ESO telescopes, including the Very Large Telescope Interferometer (VLTI). Surrounded by a complex, extended nebula that is the result of previous violent ejections, the star has been shown to have a companion. Interactions in this double system, surrounded by a dusty disc, may be the engine fuelling the star's remarkable nebula. The new image, showing a very rich field of stars towards the Carina arm of the Milky Way, is centred on the star HD 87643, a member of the exotic class of B[e] stars [1]. It is part of a set of observations that provide astronomers with the best ever picture of a B[e] star. The image was obtained with the Wide Field Imager (WFI) attached to the MPG/ESO 2.2-metre telescope at the 2400-metre-high La Silla Observatory in Chile. The image shows beautifully the extended nebula of gas and dust that reflects the light from the star. The central star's wind appears to have shaped the nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years. A team of astronomers, led by Florentin Millour, has studied the star HD 87643 in great detail, using several of ESO's telescopes. Apart from the WFI, the team also used ESO's Very Large Telescope (VLT) at Paranal. At the VLT, the astronomers used the NACO adaptive optics instrument, allowing them to obtain an image of the star free from the blurring effect of the atmosphere. To probe the object further, the team then obtained an image with the Very Large Telescope Interferometer (VLTI). The sheer range of this set of observations

  11. Electron acceleration in stochastic double layers

    NASA Technical Reports Server (NTRS)

    Lotko, William

    1987-01-01

    Transversely localized double layers evolve randomly in turbulent regions of strongly magnetized plasma carrying current along the magnetic field. Results from numerical simulations and spacecraft observations in the auroral plasma indicate that the parallel electric field in such regions is microscopically intermittent or stochastic. The implications of stochastic double layer fields on electron acceleration will be discussed in terms of a statistical process involving ensemble averages over test particle motion. A Fokker-Planck equation can be derived for the electron phase space density, which depends on the mean and rms amplitudes of the double layers, the mean double layer density, and the initial electron velocity distribution. It is shown that the resulting electron acceleration is very sensitive to the ratio of the initial electron energy to the rms double layer amplitude. When this ratio is large, the acceleration process differs little from that expected in a dc electric field. When it is small, stochastic heating competes with directed acceleration. Evidence for both cases can be found in the auroral ionosphere in association with so-called inverted-V precipitation and collimated edge precipitation.

  12. A novel mechanism for creating double pulsars

    NASA Technical Reports Server (NTRS)

    Sigurdsson, Steinn; Hernquist, Lars

    1992-01-01

    Simulations of encounters between pairs of hard binaries, each containing a neutron star and a main-sequence star, reveal a new formation mechanism for double pulsars in dense cores of globular clusters. In many cases, the two normal stars are disrupted to form a common envelope around the pair of neutron stars, both of which will be spun up to become millisecond pulsars. We predict that a new class of pulsars, double millisecond pulsars, will be discovered in the cores of dense globular clusters. The genesis proceeds through a short-lived double-core common envelope phase, with the envelope ejected in a fast wind. It is possible that the progenitor may also undergo a double X-ray binary phase. Any circular, short-period double pulsar found in the galaxy would necessarily come from disrupted disk clusters, unlike Hulse-Taylor class pulsars or low-mass X-ray binaries which may be ejected from clusters or formed in the galaxy.

  13. Double-difference adjoint seismic tomography

    NASA Astrophysics Data System (ADS)

    Yuan, Yanhua O.; Simons, Frederik J.; Tromp, Jeroen

    2016-09-01

    We introduce a `double-difference' method for the inversion for seismic wave speed structure based on adjoint tomography. Differences between seismic observations and model predictions at individual stations may arise from factors other than structural heterogeneity, such as errors in the assumed source-time function, inaccurate timings and systematic uncertainties. To alleviate the corresponding non-uniqueness in the inverse problem, we construct differential measurements between stations, thereby reducing the influence of the source signature and systematic errors. We minimize the discrepancy between observations and simulations in terms of the differential measurements made on station pairs. We show how to implement the double-difference concept in adjoint tomography, both theoretically and practically. We compare the sensitivities of absolute and differential measurements. The former provide absolute information on structure along the ray paths between stations and sources, whereas the latter explain relative (and thus higher resolution) structural variations in areas close to the stations. Whereas in conventional tomography a measurement made on a single earthquake-station pair provides very limited structural information, in double-difference tomography one earthquake can actually resolve significant details of the structure. The double-difference methodology can be incorporated into the usual adjoint tomography workflow by simply pairing up all conventional measurements; the computational cost of the necessary adjoint simulations is largely unaffected. Rather than adding to the computational burden, the inversion of double-difference measurements merely modifies the construction of the adjoint sources for data assimilation.

  14. Re-naming D Double Prime

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    1999-01-01

    "Knowledge about the dynamics of the D double prime region is a key to unlock some fundamental mysteries of the Earth heat engine which governs a wide range of global geophysical processes from tectonics to geodynamo." This benign sentence makes complete sense to many geophysicists. But for many others, it makes sense all except the odd nomenclature "D double prime". One knows about the crust, upper and lower mantle, outer and inner core, but where is the D double prime region? What meaning does it try to convey? Where is D prime region, or D, or A, B, C regions for that matter, and are there higher-order primes? How does such an odd name come about anyway? D double prime, or more "simply" D", is a generic designation given to the thin shell, about 200 km thick, of the lowermost mantle just above the core-mantle boundary inside the Earth. Incidentally, whether D" is "simpler" than "D double prime" depends on whether you are pronouncing it or writing/typing it; and D" can be confusing to readers in distinguishing quotation marks (such as in the above sentences) and second derivatives, and to word processors in spelling check and indexing.

  15. On models of double porosity poroelastic media

    NASA Astrophysics Data System (ADS)

    Boutin, Claude; Royer, Pascale

    2015-12-01

    This paper focuses on the modelling of fluid-filled poroelastic double porosity media under quasi-static and dynamic regimes. The double porosity model is derived from a two-scale homogenization procedure, by considering a medium locally characterized by blocks of poroelastic Biot microporous matrix and a surrounding system of fluid-filled macropores or fractures. The derived double porosity description is a two-pressure field poroelastic model with memory and viscoelastic effects. These effects result from the `time-dependent' interaction between the pressure fields in the two pore networks. It is shown that this homogenized double porosity behaviour arises when the characteristic time of consolidation in the microporous domain is of the same order of magnitude as the macroscopic characteristic time of transient regime. Conversely, single porosity behaviours occur when both timescales are clearly distinct. Moreover, it is established that the phenomenological approaches that postulate the coexistence of two pressure fields in `instantaneous' interaction only describe media with two pore networks separated by an interface flow barrier. Hence, they fail at predicting and reproducing the behaviour of usual double porosity media. Finally, the results are illustrated for the case of stratified media.

  16. Temperature-stable double SAW resonators.

    PubMed

    Martin, Guenter; Kunze, Reinhard; Wall, Bert

    2008-01-01

    The temperature stability of SAW resonators on quartz can be enhanced by means of double resonators. The turnover temperatures of the double resonators' components, called single resonators, are positioned above and below room temperature. As a consequence, the temperature coefficients of frequency of the 1st order (TCF1) have opposite signs at room temperature, leading to the vanishing TCF1 of the double resonators. Frequently, different turnover temperatures are adjusted by different propagation directions on an ST cut of quartz. An overview of known and new methods for compensating the temperature coefficient of frequency of the 2nd order (TCF2) of two-port and one-port SAW double resonators is given. A concept by means of which temperature-stable circuits of single resonators are found is described. Two types of temperature-stable double resonators found by applying that concept are treated in detail: 1) a two-port resonator composed of two cascaded two-port resonators and a coupling inductance, and 2) a one-port resonator comprising a series connection of one-port resonators with an inductance in parallel with each single resonator. The substrates are 35.5 degrees rotY cuts of quartz. In both cases, the shift of resonance frequency within the temperature range from -30 degrees C to 70 degrees C is smaller than 20 ppm.

  17. Double tube helical coil steam generator

    SciTech Connect

    Garabedian, G.; De Luca, R.A.

    1987-02-24

    A steam generator is described comprising a container having a closed lower end, divided into longitudinally arranged sections including an uppermost disengaging chamber, an upper plenum, and a lower plenum. The upper plenum is above the lower plenum and contains a multiplicity of double tube helical coils, wherein each of the double tube helical coils is comprised of an inner tube individually enclosed for at least a portion of its length by an outer tube to form a double tube portion and thereby define an annular gap which is outside the inner tube but enclosed by the outer tube; the inner tube being attached at one end to a feedwater inlet, and the inner tube being attached at the other end to a steam outlet; the outer tube being in open communication at both ends with the disengaging chamber; the double tube portion being in the configuration of a helix for part of its length; the upper plenum having no communication with the disengaging chamber and having restricted communication with the lower plenum such that liquid metal entering the upper plenum and flowing to the lower plenum closely contacts at least a portion of the double tube helical coils; and the annular gap being at least partially filled with liquid metal.

  18. Re-naming D Double Prime

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    1999-01-01

    "Knowledge about the dynamics of the D double prime region is a key to unlock some fundamental mysteries of the Earth heat engine which governs a wide range of global geophysical processes from tectonics to geodynamo." This benign sentence makes complete sense to many geophysicists. But for many others, it makes sense all except the odd nomenclature "D double prime". One knows about the crust, upper and lower mantle, outer and inner core, but where is the D double prime region? What meaning does it try to convey? Where is D prime region, or D, or A, B, C regions for that matter, and are there higher-order primes? How does such an odd name come about anyway? D double prime, or more "simply" D", is a generic designation given to the thin shell, about 200 km thick, of the lowermost mantle just above the core-mantle boundary inside the Earth. Incidentally, whether D" is "simpler" than "D double prime" depends on whether you are pronouncing it or writing/typing it; and D" can be confusing to readers in distinguishing quotation marks (such as in the above sentences) and second derivatives, and to word processors in spelling check and indexing.

  19. Death of period-doublings: locating the homoclinic-doubling cascade

    NASA Astrophysics Data System (ADS)

    Oldeman, Bart E.; Krauskopf, Bernd; Champneys, Alan R.

    2000-11-01

    This paper studies a natural mechanism, called a homoclinic-doubling cascade, for the disappearance of period-doubling cascades in vector fields. Simply put, an entire period-doubling cascade collides with a saddle-type equilibrium. Homoclinic-doubling cascades are known to have self-similar structure. In contrast to the well-known Feigenbaum constant, the scaling constants for homoclinic-doubling depend on the eigenvalues of the saddle equilibrium. Specifically, we present here for the first time a detailed study of homoclinic-doubling cascades in a smooth vector field, namely a three-dimensional polynomial model proposed by Sandstede. A numerical algorithm is presented for computing homoclinic-doubling cascades in general vector fields, which makes use of the program AUTO/ HOMCONT. This allows us to compute two types of homoclinic-doubling cascades, one where the primary homoclinic orbit undergoes an inclination flip bifurcation and one where it undergoes an orbit flip bifurcation. Our results bring out the scaling constants in good agreement with analytical estimates obtained from one-dimensional maps.

  20. The concept of double inlet-double outlet right ventricle: a distinct congenital heart disease.

    PubMed

    Spadotto, Veronica; Frescura, Carla; Ho, Siew Yen; Thiene, Gaetano

    The aim of this study was to estimate the incidence and to analyze the anatomy of double inlet-double outlet right ventricle complex and its associated cardiac anomalies in our autopsy series. Among the 1640 hearts with congenital heart disease of our Anatomical Collection, we reviewed the specimens with double inlet-double outlet right ventricle, according to the sequential-segmental analysis, identifying associated cardiac anomalies and examining lung histology to assess the presence of pulmonary vascular disease. We identified 14 hearts with double inlet-double outlet right ventricle (0.85%). Right atrial isomerism was observed in 10 hearts, situs solitus in 3 and left atrial isomerism in one. Regarding the mode of atrioventricular connection, all hearts but one had a common atrioventricular valve. Systemic or pulmonary venous abnormalities were noted in all patients with atrial isomerism. In nine patients a valvular or subvalvular pulmonary stenosis was present. Among the functionally "univentricular hearts", double inlet- double outlet right ventricle represents a peculiar entity, mostly in association with right atrial isomerism. Multiple cardiac anomalies are associated and may complicate surgical repair. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. High power double-scale pulses from a gain-guided double-clad fiber laser

    NASA Astrophysics Data System (ADS)

    Zhang, Haitao; Gao, Gan; Li, Qinghua; Gong, Mali

    2017-03-01

    Generation of high power double-scale pulses from a gain-guided double-clad fiber laser is experimentally demonstrated. By employing the Yb-doped 10/130 double-clad fiber as the gain medium, the laser realizes an output power of 5.1 W and pulse energy of 0.175 µJ at repetition rate of 29.14 MHz. To the best of our knowledge, this average output power is the highest among the reported double-scale pulse oscillators. The autocorrelation trace of pulses contains the short (98 fs) and long (29.5 ps) components, and the spectral bandwidth of the pulse is 27.3 nm. Such double-scale pulses are well suited for seeding the high power MOPA (master oscillator power amplifier) systems, nonlinear frequency conversion and optical coherence tomography.

  2. Double Planet Meets Triple Star

    NASA Astrophysics Data System (ADS)

    2002-08-01

    High-Resolution VLT Image of Pluto Event on July 20, 2002 A rare celestial phenomenon involving the distant planet Pluto has occurred twice within the past month. Seen from the Earth, this planet moved in front of two different stars on July 20 and August 21, respectively, providing observers at various observatories in South America and in the Pacific area with a long awaited and most welcome opportunity to learn more about the tenuous atmosphere of that cold planet. On the first date, a series of very sharp images of a small sky field with Pluto and the star was obtained with the NAOS-CONICA (NACO) adaptive optics (AO) camera mounted on the ESO VLT 8.2-m YEPUN telescope at the Paranal Observatory. With a diameter of about 2300 km, Pluto is about six times smaller than the Earth. Like our own planet, it possesses a relatively large moon, Charon , measuring 1200 km across and circling Pluto at a distance of about 19,600 km once every 6.4 days. In fact, because of the similarity of the two bodies, the Pluto-Charon system is often referred to as a double planet . At the current distance of nearly 4,500 million km from the Earth, Pluto's disk subtends a very small angle in the sky, 0.107 arcsec. It is therefore very seldom that Pluto - during its orbital motion - passes exactly in front of a comparatively bright star. Such events are known as "occultations" , and it is difficult to predict exactly when and where on the Earth's surface they are visible. Stellar occultations When Pluto moves in front of a star, it casts a "shadow" on the Earth's surface within which an observer cannot see the star, much like the Earth's Moon hides the Sun during a total solar eclipse. During the occultation event, Pluto's "shadow" also moves across the Earth's surface. The width of this shadow is equal to Pluto's diameter, i.e. about 2300 km. One such occultation event was observed in 1988, and two others were expected to occur in 2002, according to predictions published in 2000 by

  3. Excitonic superfluid phase in double bilayer graphene

    NASA Astrophysics Data System (ADS)

    Li, J. I. A.; Taniguchi, T.; Watanabe, K.; Hone, J.; Dean, C. R.

    2017-08-01

    A spatially indirect exciton is created when an electron and a hole, confined to separate layers of a double quantum well system, bind to form a composite boson. Such excitons are long-lived, and in the limit of strong interactions are predicted to undergo a Bose-Einstein condensate-like phase transition into a superfluid ground state. Here, we report evidence of an exciton condensate in the quantum Hall effect regime of double-layer structures of bilayer graphene. Interlayer correlation is identified by quantized Hall drag at matched layer densities, and the dissipationless nature of the phase is confirmed in the counterflow geometry. A selection rule for the condensate phase is observed involving both the orbital and valley indices of bilayer graphene. Our results establish double bilayer graphene as an ideal system for studying the rich phase diagram of strongly interacting bosonic particles in the solid state.

  4. Double Dirac Semimetals in Three Dimensions.

    PubMed

    Wieder, Benjamin J; Kim, Youngkuk; Rappe, A M; Kane, C L

    2016-05-06

    We study a class of Dirac semimetals that feature an eightfold-degenerate double Dirac point. We show that 7 of the 230 space groups can host such Dirac points and argue that they all generically display linear dispersion. We introduce an explicit tight-binding model for space groups 130 and 135. Space group 135 can host an intrinsic double Dirac semimetal with no additional states at the Fermi energy. This defines a symmetry-protected topological critical point, and we show that a uniaxial compressive strain applied in different directions leads to topologically distinct insulating phases. In addition, the double Dirac semimetal can accommodate topological line defects that bind helical modes. Connections are made to theories of strongly interacting filling-enforced semimetals, and potential materials realizations are discussed.

  5. Double mode Cepheids in M31

    SciTech Connect

    Poleski, Radosław

    2013-12-01

    Until now, double mode Cepheids (or beat Cepheids) were known only in the Galaxy, the Magellanic Clouds, and M33. Curiously, none of the more than 2000 Cepheids in M31 was claimed to show two pulsation modes. We conducted a systematic search for double mode Cepheids in the archival data of M31 and discovered four such objects. We identify one of the stars as a first and second overtone pulsator even though its secondary period is subject to strong aliasing. Two stars pulsate in the fundamental mode and the first overtone. Their fundamental periods are 9.392 days and 9.163 days. This makes them the first candidates for fundamental mode and first overtone Cepheids, of which double mode pulsations are caused by the 2:1 resonance of the fundamental mode and the second overtone.

  6. Double Dirac Semimetals in Three Dimensions

    NASA Astrophysics Data System (ADS)

    Wieder, Benjamin J.; Kim, Youngkuk; Rappe, A. M.; Kane, C. L.

    2016-05-01

    We study a class of Dirac semimetals that feature an eightfold-degenerate double Dirac point. We show that 7 of the 230 space groups can host such Dirac points and argue that they all generically display linear dispersion. We introduce an explicit tight-binding model for space groups 130 and 135. Space group 135 can host an intrinsic double Dirac semimetal with no additional states at the Fermi energy. This defines a symmetry-protected topological critical point, and we show that a uniaxial compressive strain applied in different directions leads to topologically distinct insulating phases. In addition, the double Dirac semimetal can accommodate topological line defects that bind helical modes. Connections are made to theories of strongly interacting filling-enforced semimetals, and potential materials realizations are discussed.

  7. Double Ramification Cycles and Quantum Integrable Systems

    NASA Astrophysics Data System (ADS)

    Buryak, Alexandr; Rossi, Paolo

    2016-03-01

    In this paper, we define a quantization of the Double Ramification Hierarchies of Buryak (Commun Math Phys 336:1085-1107, 2015) and Buryak and Rossi (Commun Math Phys, 2014), using intersection numbers of the double ramification cycle, the full Chern class of the Hodge bundle and psi-classes with a given cohomological field theory. We provide effective recursion formulae which determine the full quantum hierarchy starting from just one Hamiltonian, the one associated with the first descendant of the unit of the cohomological field theory only. We study various examples which provide, in very explicit form, new (1+1)-dimensional integrable quantum field theories whose classical limits are well-known integrable hierarchies such as KdV, Intermediate Long Wave, extended Toda, etc. Finally, we prove polynomiality in the ramification multiplicities of the integral of any tautological class over the double ramification cycle.

  8. Machine learning bandgaps of double perovskites

    NASA Astrophysics Data System (ADS)

    Pilania, Ghanshyam; Mannodi-Kanakkithodi, Arun; Uberuaga, Blas; Ramprasad, Rampi; Gubernatis, James; Lookman, Turab

    The ability to make rapid and accurate predictions of bandgaps for double perovskites is of much practical interest for a range of applications. While quantum mechanical computations for high-fidelity bandgaps are enormously computation-time intensive and thus impractical in high throughput studies, informatics-based statistical learning approaches can be a promising alternative. Here we demonstrate a systematic feature-engineering approach and a robust learning framework for efficient and accurate predictions of electronic bandgaps for double perovskites. After evaluating a set of nearly 1.2 million features, we identify several elemental features of the constituent atomic species as the most crucial and relevant predictors. The developed models are validated and tested using the best practices of data science (on a dataset of more than 1300 double perovskite bandgaps) and further analyzed to rationalize their prediction performance. Los Alamos National Laboratory LDRD program and the U.S. Department of Energy, Office of Science, Basic Energy Sciences.

  9. The Dissolution of Double Holliday Junctions

    PubMed Central

    Bizard, Anna H.; Hickson, Ian D.

    2014-01-01

    Double Holliday junctions (dHJS) are important intermediates of homologous recombination. The separate junctions can each be cleaved by DNA structure-selective endonucleases known as Holliday junction resolvases. Alternatively, double Holliday junctions can be processed by a reaction known as “double Holliday junction dissolution.” This reaction requires the cooperative action of a so-called “dissolvasome” comprising a Holliday junction branch migration enzyme (Sgs1/BLM RecQ helicase) and a type IA topoisomerase (Top3/TopoIIIα) in complex with its OB (oligonucleotide/oligosaccharide binding) fold containing accessory factor (Rmi1). This review details our current knowledge of the dissolution process and the players involved in catalyzing this mechanistically complex means of completing homologous recombination reactions. PMID:24984776

  10. Toda Equations and Piecewise Polynomiality for Mixed Double Hurwitz Numbers

    NASA Astrophysics Data System (ADS)

    Goulden, I. P.; Guay-Paquet, Mathieu; Novak, Jonathan

    2016-04-01

    This article introduces mixed double Hurwitz numbers, which interpolate combinatorially between the classical double Hurwitz numbers studied by Okounkov and the monotone double Hurwitz numbers introduced recently by Goulden, Guay-Paquet and Novak. Generalizing a result of Okounkov, we prove that a certain generating series for the mixed double Hurwitz numbers solves the 2-Toda hierarchy of partial differential equations. We also prove that the mixed double Hurwitz numbers are piecewise polynomial, thereby generalizing a result of Goulden, Jackson and Vakil.

  11. Period-Doubling Bifurcation in Nonlinear Systems

    NASA Astrophysics Data System (ADS)

    Mao, Jian-Min

    The dependence of the critical exponents, such as the Feigenbaum ratios, of the period-doubling bifurcation on the order of critical point z is studied. The dependence is quantitatively given for one-dimensional dissipative maps. The scaling factor in the period-doubling power spectrum of a class of two-dimensional area-preserving maps is found to approach a universal limit by both fast Fourier transform and autocorrelation-function analysis. The dependence of the fractal dimension on the critical-point order is studied. The variation of the three most commonly used definitions of dimension, viz., the capacity, the information dimension, and the correlation exponent, is computed as a function of z. The numerical values agree very well with analytical estimates. The dependence of the scaling of the period-doubling bifurcation on the dimensionality of the reduced phase space is considered. Especially, the investigation of period-doubling bifurcations in four-dimensional symplectic maps indicates the existence of an universally self-similar period-doubling sequence. The fixed-point map has two unstable directions under the period-doubling operator with two relevant eigenvalues. The four orbital scaling factors have been found. As an extension of the Feigenbaum scaling law for parameter and orbital element, a many-term scaling law is suggested. For one-dimensional dissipative maps, two-dimensional area-preserving maps, and four-dimensional symplectic maps, the many-term scaling law is very well obeyed. New scaling factors have been found.

  12. Hamilton Jeffers and the Double Star Catalogues

    NASA Astrophysics Data System (ADS)

    Tenn, Joseph S.

    2013-01-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Court reporter and amateur astronomer Shelburne Wesley Burnham (1838-1921) published a massive double star catalogue containing more than 13,000 systems in 1906. The next keeper of the double stars was Lick Observatory astronomer Robert Grant Aitken (1864-1951), who produced a much larger catalogue in 1932. Aitken maintained and expanded Burnham’s records of observations on handwritten file cards, eventually turning them over to Lick Observatory astrometrist Hamilton Moore Jeffers (1893-1976). Jeffers further expanded the collection and put all the observations on punched cards. With the aid of Frances M. "Rete" Greeby (1921-2002), he made two catalogues: an Index Catalogue with basic data about each star, and a complete catalogue of observations, with one observation per punched card. He enlisted Willem van den Bos of Johannesburg to add southern stars, and they published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers approached retirement he became greatly concerned about the disposition of the catalogues. He wanted to be replaced by another "double star man," but Lick Director Albert E. Whitford (1905-2002) had the new 120-inch reflector, the world’s second largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers was vociferously opposed to turning over the card files to another institution, and especially against their coming under the control of Kaj Strand of the U.S. Naval Observatory. In the end the USNO got the files and has maintained the records ever since, first under Charles Worley (1935-1997), and, since 1997, under Brian Mason. Now called the Washington Double Star Catalog (WDS), it is completely online and currently contains more than 1,000,000 measures of more than 100,000 pairs.

  13. Magic-angle turning with double acquisition.

    PubMed

    Matsunaga, Tatsuya; Takegoshi, K

    2017-01-01

    The double-acquisition scheme for efficient data collection of hypercomplex data (the States method) of a two-dimensional experiment is adopted to magic-angle hopping (MAH) and magic-angle turning (MAT) experiments, which are powerful methods to measure the principal values of the chemical shift anisotropy (CSA) in a powder sample. It is shown that the double acquisition MAT (DAMAT) sequence realizes the S/N ratio comparable to or better than those of other variants of the MAH/MAT sequences. In addition, we show that DAMAT has preferable features that there are no spinning sidebands in the indirect dimension, and no spectral shearing is necessary.

  14. Why search for double beta decay

    SciTech Connect

    Kayser, B.

    1988-04-20

    Searching for neutrinoless double beta decay is the only known practical method for trying to determine whether neutrinos are their own antiparticles. The theoretical motivation for supposing that they may indeed be their own antiparticles is described. The reason that it is so difficult to ascertain experimentally whether they are or are not is explained, as is the special sensitivity of neutrinoless double beta decay. The potential implications of the observation of this reaction for neutrino mass and for the physics of neutrinos is discussed.

  15. de Sitter and double asymmetric brane worlds

    SciTech Connect

    Guerrero, Rommel; Rodriguez, R. Omar; Torrealba, Rafael

    2005-12-15

    Asymmetric brane worlds with dS expansion and static double kink topology are obtained from a recently proposed method and their properties are analyzed. These domain walls interpolate between two spacetimes with different cosmological constants. In the dynamic case, the vacua correspond to dS and AdS geometry, unlike the static case where they correspond to AdS background. We show that it is possible to confine gravity on such branes. In particular, the double-brane world hosts two different walls, so that the gravity is localized on one of them.

  16. Magic-angle turning with double acquisition

    NASA Astrophysics Data System (ADS)

    Matsunaga, Tatsuya; Takegoshi, K.

    2017-01-01

    The double-acquisition scheme for efficient data collection of hypercomplex data (the States method) of a two-dimensional experiment is adopted to magic-angle hopping (MAH) and magic-angle turning (MAT) experiments, which are powerful methods to measure the principal values of the chemical shift anisotropy (CSA) in a powder sample. It is shown that the double acquisition MAT (DAMAT) sequence realizes the S/N ratio comparable to or better than those of other variants of the MAH/MAT sequences. In addition, we show that DAMAT has preferable features that there are no spinning sidebands in the indirect dimension, and no spectral shearing is necessary.

  17. Bilateral double level tibial lengthening in dwarfism☆

    PubMed Central

    Burghardt, Rolf D.; Yoshino, Koichi; Kashiwagi, Naoya; Yoshino, Shigeo; Bhave, Anil; Paley, Dror; Herzenberg, John E.

    2015-01-01

    Purpose Outcome assessment after double level tibial lengthening in patients with dwarfism. Methods Fourteen patients with dwarfism were analyzed after bilateral simultaneous double level tibial lengthening. Results Average age was 15.1 years. Average lengthening was 13.5 cm. The two levels were lengthened by an average of 7.5 cm proximally and 6.0 cm distally. Concomitant deformities were also addressed during lengthening. External fixation treatment time averaged 8.8 months. Healing index averaged 0.7 months/cm. Conclusion Bilateral tibial lengthening for dwarfism is difficult, but the results are usually quite gratifying. PMID:26566326

  18. Higher spin double field theory: a proposal

    NASA Astrophysics Data System (ADS)

    Bekaert, Xavier; Park, Jeong-Hyuck

    2016-07-01

    We construct a double field theory coupled to the fields present in Vasiliev's equations. Employing the "semi-covariant" differential geometry, we spell a functional in which each term is completely covariant with respect to O(4, 4) T-duality, doubled diffeomorphisms, Spin(1, 3) local Lorentz symmetry and, separately, HS(4) higher spin gauge symmetry. We identify a minimal set of BPS-like conditions whose solutions automatically satisfy the full Euler-Lagrange equations. As such a solution, we derive a linear dilaton vacuum. With extra algebraic constraints further supplemented, the BPS-like conditions reduce to the bosonic Vasiliev equations.

  19. BLOCKING OSCILLATOR DOUBLE PULSE GENERATOR CIRCUIT

    DOEpatents

    Haase, J.A.

    1961-01-24

    A double-pulse generator, particuiarly a double-pulse generator comprising a blocking oscillator utilizing a feedback circuit to provide means for producing a second pulse within the recovery time of the blocking oscillator, is described. The invention utilized a passive network which permits adjustment of the spacing between the original pulses derived from the blocking oscillator and further utilizes the original pulses to trigger a circuit from which other pulses are initiated. These other pulses are delayed and then applied to the input of the blocking oscillator, with the result that the output from the oscillator circuit contains twice the number of pulses originally initiated by the blocking oscillator itself.

  20. Double-Beta Decay at TUNL

    NASA Astrophysics Data System (ADS)

    Kidd, Mary

    2007-10-01

    Studying double-beta decay at Triangle Universities Nuclear Laboratory (TUNL) is perhaps one of the most promising ways to pinpoint the neutrino mass. What they do not mention is that to study double-beta decay, you probably have to become a certified miner, and if you have a fear of goats, you should stay away. In this talk, I will tell you some of my experiences as a TUNL graduate student, and how I am now nearly qualified for a job in the mining industry.