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  1. X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus

    Directory of Open Access Journals (Sweden)

    Adauto Lima Cardoso

    2015-06-01

    Full Text Available Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B . n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes.

  2. When is f(x1,x2,... ,xn)

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    When is f(x1,x2,... ,xn) = u1(x1) + u2(x2) +···+ un(xn)? ... (i) there exist non-zero integers p1,p2,... ,pk such that ..... probability measure for the countable collection of functions 1Ai , i = 1, 2, 3,. .... For question (B) a sufficient condition is that.

  3. Ranked solutions of the matric equation A1X1=A2X2

    Directory of Open Access Journals (Sweden)

    A. Duane Porter

    1980-01-01

    Full Text Available Let GF(pz denote the finite field of pz elements. Let A1 be s×m of rank r1 and A2 be s×n of rank r2 with elements from GF(pz. In this paper, formulas are given for finding the number of X1,X2 over GF(pz which satisfy the matric equation A1X1=A2X2, where X1 is m×t of rank k1, and X2 is n×t of rank k2. These results are then used to find the number of solutions X1,…,Xn, Y1,…,Ym, m,n>1, of the matric equation A1X1…Xn=A2Y1…Ym.

  4. SISTEMA DE CROMOSSOMOS SEXUAIS MÚLTIPLOS X1X1X2X2/X1X2Y NA MOSCA-DAS-FRUTAS Anastrepha sororcula (DIPTERA: TEPHRITIDAE

    Directory of Open Access Journals (Sweden)

    Inês Regina de Araújo Moura Cunha

    2014-08-01

    Full Text Available Sistemas de cromossomos sexuais simples estão difundidos entre os Tephritidae do gênero Anastrepha. Espécies deste gênero apresentam enorme importância pelo impacto que causam em frutíferas cultivadas, sobretudo no nordeste do Brasil. Análises citogenéticas desenvolvidas em Anastrepha sororcula, através da análise da estrutura cariotípica e bandamento C revelaram a presença de um sistema de cromossomos sexuais múltiplos do tipo X1X1X2X2/X1X2Y nesta espécie. Enquanto as fêmeas apresentam um cariótipo homomórfico com 2n=12, os machos possuem 2n=11, onde se destaca um grande cromossomo Y despareado. O nível de divergência cariotípica da espécie A. sororcula do nordeste, com a presença de um sistema de cromossomos sexuais múltiplos, em relação às regiões central e sudeste do Brasil, podem indicar a ocorrência de impedimentos reprodutivos entre os exemplares das duas áreas e que possivelmente, como outros exemplos que existem neste gênero, A. sororcula constitua um complexo de espécies ainda não inteiramente definido. Palavras-chave: Alossomos, peste agrícola, citogenética de insetos, heterocromatina. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n2p1-4

  5. Metal-insulator transition in Si(111)-(4 x 1)/(8 x 2)-In studied by optical spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Speiser, E.; Hinrichs, K.; Cobet, C.; Esser, N. [Leibniz-Institut fuer Analytische Wissenschaften - ISAS - e.V., Albert-Einstein-Str. 9, 12489 Berlin (Germany); Chandola, S. [Leibniz-Institut fuer Analytische Wissenschaften - ISAS - e.V., Albert-Einstein-Str. 9, 12489 Berlin (Germany); School of Physics, Trinity College Dublin 2 (Ireland); Gensch, M. [Helmholtz Zentrum Berlin (Germany); Wippermann, S.; Schmidt, W.G. [Theoretische Physik, Universitaet Paderborn (Germany); Bechstedt, F. [Institut fuer Festkoerpertheorie und -Optik, Friedrich-Schiller-Universitaet, Jena (Germany); Richter, W. [Dipartimento di Fisica, Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Fleischer, K.; McGilp, J.F. [School of Physics, Trinity College Dublin 2 (Ireland)

    2010-08-15

    Measurements of the surface vibrational modes and optical response of Si(111)-(4 x 1)/(8 x 2)-In are compiled and a comparison to ab initio calculations performed within DFT-LDA formalism is given. Surface resonant Raman spectroscopy allows identifying a number of surface phonons with high spectral precision. The phase transition of the (4 x 1)-(8 x 2) surface structure is found to be accompanied by characteristic changes of the surface phonons, which are discussed with respect to various structural models suggested. The optical anisotropy of the (8 x 2) phase shows that the anisotropic Drude tail of the (4 x 1) phase is replaced by two peaks at 0.50 and 0.72 eV. The spectroscopic signatures of the (4 x 1) and (8 x 2) phases agree with a metal-insulator transition. The mid-IR-anisotropic optical response of the insulating (8 x 2) phase is interpreted in terms of electronic single particle excitations between surface electronic bands related to the In-nanowire surface. Comparison of the measured optical transitions with DFT ab initio calculations for the hexagon model and the trimer model of the (8 x 2) structure shows evidence for the existence of the hexagon structure. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  6. The trypanosome Rab-related proteins RabX1 and RabX2 play no role in intracellular trafficking but may be involved in fly infectivity.

    Directory of Open Access Journals (Sweden)

    Senthil Kumar A Natesan

    2009-09-01

    Full Text Available Rab GTPases constitute the largest subgroup of the Ras superfamily and are primarily involved in vesicle targeting. The full extent of Rab family function is unexplored. Several divergent Rab-like proteins are known but few have been characterized. In Trypanosoma brucei there are sixteen Rab genes, but RabX1, RabX2 and RabX3 are divergent within canonical sequence regions. Where known, trypanosome Rab functions are broadly conserved when orthologous relationships may be robustly established, but specific functions for RabX1, X2 and X3 have yet to be determined. RabX1 and RabX2 originated via tandem duplication and subcellular localization places RabX1 at the endoplasmic reticulum, while RabX2 is at the Golgi complex, suggesting distinct functions. We wished to determine whether RabX1 and RabX2 are involved in vesicle transport or other cellular processes.Using comparative genomics we find that RabX1 and RabX2 are restricted to trypanosomatids. Gene knockout indicates that RabX1 and RabX2 are non-essential. Simultaneous RNAi knockdown of both RabX1 and RabX2, while partial, was also non-lethal and may suggest non-redundant function, consistent with the distinct locations of the proteins. Analysis of the knockout cell lines unexpectedly failed to uncover a defect in exocytosis, endocytosis or in the morphology or location of multiple markers for the endomembrane system, suggesting that neither RabX1 nor RabX2 has a major role in intracellular transport. However, it was apparent that RabX1 and RabX2 knockout cells displayed somewhat enhanced survival within flies.RabX1 and RabX2, two members of the trypanosome Rab subfamily, were shown to have no major detectable role in intracellular transport, despite the localization of each gene product to highly specific endomembrane compartments. These data extend the functional scope of Rab proteins in trypanosomes to include non-canonical roles in differentiation-associated processes in protozoa.

  7. The ultraluminous x-ray sources ngc 1313 x-1 and x-2: a broadband study with NuSTAR and XMM-Newton

    DEFF Research Database (Denmark)

    Bachetti, Matteo; Rana, Vikram; Walton, Dominic J.

    2013-01-01

    We present the results of NuSTAR and XMM-Newton observations of the two ultraluminous X-ray sources: NGC 1313 X-1 and X-2. The combined spectral bandpass of the two satellites enables us to produce the first spectrum of X-1 between 0.3 and 30 keV, while X-2 is not significantly detected by NuSTAR...

  8. Bismuth on copper (110): analysis of the c(2x2) and p(4x1) structures by surface x-ray diffraction

    DEFF Research Database (Denmark)

    Lottermoser, L.; Buslaps, T.; Johnson, R.L.

    1997-01-01

    Surface X-ray diffraction has been used to analyze the atomic structures of the Cu(110)-c(2 x 2)-Bi and Cu(110)-p(4 x 1)-Bi reconstructions with submonolayer coverages. A quasi-hexagonal c(2 x 2) adlayer structure is formed when half a monolayer of bismuth is deposited; the coverage corresponds...... to 1.08 x 10(-15) atoms cm(-2). There is one Bi atom per c(2 x 2) surface unit cell, and the nearest-neighbor distance on the planar overlayer was found to be 4.43 Angstrom. In the case of the p(4 x 1) reconstruction formed at a coverage of 0.75 monolayers, both the in-plane and out-of-plane data...

  9. The ultraluminous X-ray sources NGC 1313 X-1 and X-2: A broadband study with NuSTAR and XMM-Newton

    Energy Technology Data Exchange (ETDEWEB)

    Bachetti, Matteo; Barret, Didier; Webb, Natalie A. [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Rana, Vikram; Walton, Dominic J.; Harrison, Fiona A.; Fürst, Felix; Grefenstette, Brian W.; Madsen, Kristin K. [Cahill Center for Astronomy and Astrophysics, Caltech, Pasadena, CA 91125 (United States); Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Fabian, Andrew C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Hornschemeier, Ann; Ptak, Andrew F.; Zhang, William W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Miller, Jon M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Stern, Daniel, E-mail: matteo.bachetti@irap.omp.eu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2013-12-01

    We present the results of NuSTAR and XMM-Newton observations of the two ultraluminous X-ray sources: NGC 1313 X-1 and X-2. The combined spectral bandpass of the two satellites enables us to produce the first spectrum of X-1 between 0.3 and 30 keV, while X-2 is not significantly detected by NuSTAR above 10 keV. The NuSTAR data demonstrate that X-1 has a clear cutoff above 10 keV, whose presence was only marginally detectable with previous X-ray observations. This cutoff rules out the interpretation of X-1 as a black hole in a standard low/hard state, and it is deeper than predicted for the downturn of a broadened iron line in a reflection-dominated regime. The cutoff differs from the prediction of a single-temperature Comptonization model. Further, a cold disk-like blackbody component at ∼0.3 keV is required by the data, confirming previous measurements by XMM-Newton only. We observe a spectral transition in X-2, from a state with high luminosity and strong variability to a lower-luminosity state with no detectable variability, and we link this behavior to a transition from a super-Eddington to a sub-Eddington regime.

  10. Extraction of UO22+ by two highly sterically hindered (X1) (X2) PO(OH) extractants from an aqueous chloride phase

    International Nuclear Information System (INIS)

    Mason, G.W.; Lewey, S.M.; Gilles, D.M.; Peppard, D.F.

    1978-01-01

    The comparative extraction behaviour of tracer-level UO 2 2+ into benzene solutions of two highly sterically hindered extractants, di(2,6-di-iso-propylphenyl) phosphoric acid, HD(2,6-i-PPHI)P and di-tertiary-butyl phosphinic acid, H[Dt-BP], vs an aqueous 1.0 F (NaCl + HCl) phase was studied. The extraction of UO 2 2+ in both systems is directly second-power dependent upon extractant concentration and inversely second-power dependent upon hydrogen ion concentration, the stoichiometry of extraction being UOsub(2A) 2+ + 2(HY)sub(2O) = UO 2 (HY 2 )sub(2O) + 2Hsub(A) + . The expression for the distribution ratio, K is K = Ksub(s)F 2 /[H + ] 2 the general expression for the extraction of any metallic species being K - Ksub(s)Fsup(a)/[H + ]sup(b) where Ksub(s) is a constant characteristic of the system, F the concentration in formality units of extractant in the organic phase, [H + ] the concentration of hydrogen ion in the aqueous phase, and a and b the respective extractant and hydrogen-ion dependencies. Both extractants have a high degree of steric hindrance. The HD(2,6-i-PPHI)P is the more highly acidic, the pKsub(A) value, in 75% ethanol, being 3.2. The pKsub(A), previously reported, for H[Dt-BP] is 6.26. The Ksub(s) for UO 2 2+ in the system HY in benzene diluent vs an aqueous 1.0 F (NaCl + HCl) phase is 2 x 10 4 for H[Dt-BP] and 3 x 10 -1 for HD(2,6-i-PPHI)P; the ratio of the Ksub(s) values nearly 7 x 10 3 , favours the less acidic extractant. For comparative purposes, the Ksub(s) values for UO 2 2+ and for Am 3+ and Eu 3+ in other (X 1 )(X 2 )PO(OH), in benzene diluent, vs 1.0 F (NaCl + HCl) systems are presented. The variations are discussed in terms of the pKsub(A) of the extractant and the steric hindrance within the extractant. (author)

  11. Study of TiO2(1 1 0)-p(1x1), p(1x2) and p(1x3) surface structures by impact collision ion scattering spectroscopy (ICISS)

    International Nuclear Information System (INIS)

    Asari, E.; Souda, R.

    2000-01-01

    The surface structure of TiO 2 (1 1 0)-p(1x1), p(1x2) and p(1x3) were studied using impact collision ion scattering spectroscopy (ICISS). We found that (i) the height of bridging oxygen for the p(1x1) is comparative to that of bulk structure, (ii) the p(1x2) surface has the added Ti 2 O 3 unit rows proposed by Onishi et al. and also the oxygen atoms rows between Ti 2 O 3 unit rows and (iii) the p(1x3) surface is constructed with the same added Ti 2 O 3 unit rows as that in the p(1x2) surface, but the bridging oxygen rows exist between the Ti 2 O 3 unit rows

  12. Silica-supported tungsten carbynes (≡SiO)xW(≡CH)(Me)y (x = 1, y = 2; X = 2, y = 1): New efficient catalysts for alkyne cyclotrimerization

    KAUST Repository

    Riache, Nassima

    2015-02-23

    The activity of silica-supported tungsten carbyne complexes (≡SiO)xW(≡CH)(Me)y (x = 1, y = 2; x = 2, y = 1) toward alkynes is reported. We found that they are efficient precatalysts for terminal alkyne cyclotrimerization with high TONs. We also demonstrate that this catalyst species is active for alkyne cyclotrimerization without the formation of significant alkyne metathesis products. Additional DFT calculations highlight the importance of the W coordination sphere in supporting this experimental behavior.

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

    Science.gov (United States)

    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

  14. Ab initio chemical kinetics for SiH3 reactions with Si(x)H2x+2 (x = 1-4).

    Science.gov (United States)

    Raghunath, P; Lin, M C

    2010-12-30

    Gas-phase kinetics and mechanisms of SiH(3) reactions with SiH(4), Si(2)H(6), Si(3)H(8), and Si(4)H(10), processes of relevance to a-Si thin-film deposition, have been investigated by ab initio molecular orbital and transition-state theory (TST) calculations. Geometric parameters of all the species involved in the title reactions were optimized by density functional theory at the B3LYP and BH&HLYP levels with the 6-311++G(3df,2p) basis set. The potential energy surface of each reaction was refined at the CCSD(T)/6-311++G(3df,2p) level of theory. The results show that the most favorable low energy pathways in the SiH(3) reactions with these silanes occur by H abstraction, leading to the formation of SiH(4) + Si(x)H(2x+1) (silanyl) radicals. For both Si(3)H(8) and n-Si(4)H(10) reactions, the lowest energy barrier channels take place by secondary Si-H abstraction, yielding SiH(4) + s-Si(3)H(7) and SiH(4) + s-Si(4)H(9), respectively. In the i-Si(4)H(10) reaction, tertiary Si-H abstraction has the lowest barrier producing SiH(4) + t-Si(4)H(9). In addition, direct SiH(3)-for-X substitution reactions forming Si(2)H(6) + X (X = H or silanyls) can also occur, but with significantly higher reaction barriers. A comparison of the SiH(3) reactions with the analogous CH(3) reactions with alkanes has been made. The rate constants for low-energy product channels have been calculated for the temperature range 300-2500 K by TST with Eckart tunneling corrections. These results, together with predicted heats of formation of various silanyl radicals and Si(4)H(10) isomers, have been tabulated for modeling of a-Si:H film growth by chemical vapor deposition.

  15. IR emission and electrical conductivity of Nd/Nb-codoped TiO{sub x} (1.5 < x < 2) thin films grown by pulsed-laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tchiffo-Tameko, C.; Cachoncinlle, C. [GREMI, UMR 7344 CNRS-Université Orléans, 45067 Orléans Cedex 2 (France); Perriere, J. [Sorbonne Universités, UPMC Université Paris 06, UMR 7588, INSP, 75005 Paris (France); CNRS, UMR 7588, INSP, 75005 Paris (France); Nistor, M. [NILPRP, L 22 P.O. Box MG-36, 77125 Bucharest-Magurele (Romania); Petit, A.; Aubry, O. [GREMI, UMR 7344 CNRS-Université Orléans, 45067 Orléans Cedex 2 (France); Pérez Casero, R. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Millon, E., E-mail: eric.millon@univ-orleans.fr [GREMI, UMR 7344 CNRS-Université Orléans, 45067 Orléans Cedex 2 (France)

    2016-12-15

    Highlights: • Nd/Nb-codoped TiO{sub 2} PLD films are electrically insulating and transparent in the UV visible NIR spectral domain. • Nd/Nb-codoped oxygen deficient TiO{sub x} (x ≈ 1.5) films are conductive and absorbent. • IR emission of Nd{sup 3+} in codoped TiO{sub x} films is quenched due to oxygen deficiency. • High Nb-doping rate decreases the IR emission of Nd{sup 3+} in Nd/Nb-codoped TiO{sub 2} films. - Abstract: The effect of the co-doping with Nd and Nb on electrical and optical properties of TiO{sub x} films is reported. The role of oxygen vacancies on the physical properties is also evidenced. The films are grown by pulsed-laser deposition onto (001) sapphire and (100) silicon substrates. The substrate temperature was fixed at 700 °C. To obtain either stoichiometric (TiO{sub 2}) or highly oxygen deficient (TiO{sub x} with x < 1.6) thin films, the oxygen partial pressure was adjusted at 10{sup −1} and 10{sup −6} mbar, respectively. 1%Nd-1%Nb, 1%Nd-5%Nb and 5%Nd-1%Nb co-doped TiO{sub 2} were used as bulk ceramic target. Composition, structural and morphological properties of films determined by Rutherford backscattering spectroscopy, X-ray diffraction and scanning electron microscopy, are correlated to their optical (UV–vis transmission and photoluminescence) and electrical properties (resistivity at room temperature). The most intense Nd{sup 3+} emission in the IR domain is obtained for stoichiometric films. Codoping Nd-TiO{sub x} films by Nb{sup 5+} ions is found to decrease the photoluminescence efficiency. The oxygen pressure during the growth allows to tune the optical and electrical properties: insulating and highly transparent (80% in the visible range) Nd/Nb codoped TiO{sub 2} films are obtained at high oxygen pressure, while conductive and absorbent films are grown under low oxygen pressure (10{sup −6} mbar).

  16. A new global analytical potential energy surface of NaH2+ system and dynamical calculation for H(2S) + NaH+(X2Σ+) → Na+(1S) + H2(X1Σg+) reaction

    Science.gov (United States)

    Yuan, Meiling; Li, Wentao; Yuan, Jiuchuang

    2018-05-01

    A new global potential energy surface (PES) of the NaH2+ system is constructed by fitting 27,621 ab initio energy points with the neural network method. The root mean square error of the new PES is only 4.1609 × 10-4 eV. Based on the new PES, dynamical calculations have been performed using the time-dependent quantum wave packet method. These results are then compared with the H(2S) + LiH+(X2Σ+) → Li+(1S) + H2(X1Σg+) reaction. The direct abstract mechanism is found to play an important role in the reaction because only forward scattering signals on the differential cross section results for all calculated collision energies.

  17. Language Learning Actions in Two 1x1 Secondary Schools in Catalonia: The Case of Online Language Resources

    Science.gov (United States)

    Calvo, Boris Vázquez; Cassany, Daniel

    2016-01-01

    This paper identifies and describes current attitudes towards classroom digitization and digital language learning practices under the umbrella of EduCAT 1x1, the One-Laptop-Per-Child (OLPC or 1x1) initiative in place in Catalonia. We thoroughly analyze practices worked out by six language teachers and twelve Compulsory Secondary Education (CSE)…

  18. The (p, ρ, T, x) properties of (x1 propane + x2n-butane) with x1 (0.0000, 0.2729, 0.5021, and 0.7308) over the temperature range from (280 to 440) K at pressures from (1 to 200) MPa

    International Nuclear Information System (INIS)

    Miyamoto, H.; Uematsu, M.

    2008-01-01

    The (p, ρ, T, x) properties for (x 1 propane + x 2 n-butane) with x 1 = (0.0000, 0.2729, 0.5021, and 0.7308) in the compressed liquid phase were measured by means of a metal-bellows variable volumometer over the temperature range from (280 to 440) K at pressures from (1 to 200) MPa. The mole fraction purities of the propane and n-butane used in the measurements were 0.9999 and 0.9997, respectively. The expanded uncertainties (k = 2) in temperature, pressure, density, and composition measurements have been estimated to be less than ±3 mK; 1.4 kPa (p ≤ 7 MPa), 0.06% (7 MPa 150 MPa); 0.09%; and 4.4 . 10 -4 , respectively. In the region above 100 MPa at T = (280 and 440) K, the uncertainty in density measurements increases from 0.09% to 0.13% and 0.22%, respectively. Comparisons of the available equation of state with the present measurements are reported. On the basis of the present results, the excess molar volume v m E of the mixtures was calculated and illustrated as a function of temperature and pressure

  19. Understanding the -C-X1-X2-C- motif in the active site of the thioredoxin superfamily: E. coli DsbA and its mutants as a model system.

    Science.gov (United States)

    Karshikoff, Andrey; Nilsson, Lennart; Foloppe, Nicolas

    2013-08-27

    E. coli DsbA is an intensively studied enzyme of the thioredoxin superfamily of thiol-disulfide oxidoreductases. DsbA catalyzes the disulfide bond formation and folding of proteins in the bacterial periplasm. DsbA and its mutants have highlighted the strong and puzzling influence of the -C-X1-X2-C- active site variants, found across the thioredoxin superfamily, on the ionization and redox properties of this site. However, the interpretation of these observations remains wanting, largely due to a dearth of structural information. Here, molecular dynamics simulations are used to provide extensive information on the structure and dynamics of reduced -C30-X31-X32-C33- motifs in wild type DsbA and 13 of its mutants. These simulations are combined with calculations of the pK of H32 and of the very low pK of the catalytic cysteine C30. In wild type DsbA, the titrations of C30 and H32 are shown to be coupled; the protonation states and dynamics of H32 are examined. The thiolate of C30 is stabilized by hydrogen bonds with the protein. Modulation of these hydrogen bonds by alteration of residue X32 has the greatest impact on the pK of C30, which rationalizes its higher pK in thioredoxin and tryparedoxin. Because of structural constrains, residue X31 has only an indirect and weak influence on the pK of C30. The dynamics of C30 is clearly related to its stabilizing interactions and pK value. Although relatively small differences between pKs were not reproduced in the calculations, the major trends are explained, adding new insights to our understanding of enzymes in this family.

  20. Study in crossed molecular beams of the state-to-state reactive collision: O("1D) + H_2(X "1Σ_g"+,v) → OH(X "2Π and A"2Σ"+,v',J') + H("2S)

    International Nuclear Information System (INIS)

    Drawin, Stefan

    1990-01-01

    Reactions between oxygen and hydrogen such as O + H_2 → OH + H play a significant role in combustion processes and in atmospheric and interstellar chemistry. But they are also examples of reactive collisions between atoms and molecules which can be addressed theoretically and experimentally for a better understanding of mechanisms present in a chemical reaction. This research thesis reports the experimental study of two reactive ways involving the metastable compound O("1D): O("1D) + H_2 → OH(X "2Π) + H O("1D) + H_2 → OH(A "2Σ"+) + H. The experiment is performed by using crossed molecular beams. Thus, the nature of reactants is well defined, and the interaction medium is rarefied. The first way is largely exothermic, whereas for the second one, endothermicity is overcome by H_2 vibrational excitation. A characterization of reactants is performed. Three methods of analysis of the OH product are used: time-of-flight measurement at different angles, laser induced fluorescence, and spontaneous fluorescence [fr

  1. Quantum dynamics of the reaction H((2)S) + HeH(+)(X(1)Σ(+)) → H2(+)(X(2)Σg(+)) + He((1)S) from cold to hyperthermal energies: time-dependent wavepacket study and comparison with time-independent calculations.

    Science.gov (United States)

    Gamallo, Pablo; Akpinar, Sinan; Defazio, Paolo; Petrongolo, Carlo

    2014-08-21

    We present the adiabatic quantum dynamics of the proton-transfer reaction H((2)S) + HeH(+)(X(1)Σ(+)) → H2(+)(X(2)Σg(+)) + He((1)S) on the HeH2(+) X̃(2)Σ(+) RMRCI6 (M = 6) PES of C. N. Ramachandran et al. ( Chem. Phys. Lett. 2009, 469, 26). We consider the HeH(+) molecule in the ground vibrational–rotational state and obtain initial-state-resolved reaction probabilities and the ground-state cross section σ0 and rate constant k0 by propagating time-dependent, coupled-channel, real wavepackets (RWPs) and performing a flux analysis. Three different wavepackets are propagated to describe the wide range of energies explored, from cold (0.0001 meV) to hyperthermal (1000 meV) collision energies, and in a temperature range from 0.01 to 2000 K. We compare our time-dependent results with the time-independent ones by D. De Fazio and S. Bovino et al., where De Fazio carried out benchmark coupled-channel calculations whereas Bovino et al. employed the negative imaginary potential and the centrifugal-sudden approximations. The RWP cross section is in good agreement with that by De Fazio, except at the lowest collision energies below ∼0.01 meV, where the former is larger than the latter. However, neither the RWP and De Fazio results possess the huge resonance in probability and cross section at 0.01 meV, found by Bovino et al., who also obtained a too low σ0 at high energies. Therefore, the RWP and De Fazio rate constants compare quite well, whereas that by Bovino et al. is in general lower.

  2. 4E x 2 Instructional Model: Uniting Three Learning Constructs to Improve Praxis in Science and Mathematics Classrooms

    Science.gov (United States)

    Marshall, Jeff C.; Horton, Bob; Smart, Julie

    2009-01-01

    After decades of research endorsing inquiry-based learning, at best only moderate success has been noted in creating effective systemic implementation in K-12 classrooms. Thus, teachers need to be better equipped in how to bring this transformation to their own classrooms. Changing beliefs and overcoming external obstacles encourages the use of…

  3. Droid X2 The Missing Manual

    CERN Document Server

    Gralla, Preston

    2011-01-01

    Droid X2 has more power and better graphics than its predecessor, but it still doesn't offer a printed guide to its amazing features. This Missing Manual helps you dig deep into everything Droid X2 can do. Learn how to shop, keep in touch, play with photos, listen to music, and even do some work. Unleash the power of this popular device with expert advice. The important stuff you need to know: Get organized. Sync Droid X2 with Google Calendar, Exchange, and Outlook.Go online. Navigate the Web, use email, and tap into Facebook and Twitter.Listen to tunes. Play and manage music using Droid X2'

  4. Mixed-Up Sex Chromosomes: Identification of Sex Chromosomes in the X1X1X2X2/X1X2Y System of the Legless Lizards of the Genus Lialis (Squamata: Gekkota: Pygopodidae)

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Johnson Pokorná, Martina; Altmanová, M.; Kratochvíl, L.

    2016-01-01

    Roč. 149, č. 4 (2016), s. 282-289 ISSN 1424-8581 Institutional support: RVO:67985904 Keywords : fluorescence in situ hybridization * interstitial telometric repeats * male heterogamety Subject RIV: EG - Zoology Impact factor: 1.354, year: 2016

  5. RELATIONSHIP BETWEEN ATTITUDES LEARNING AND ACHIEVEMENT OF INTEREST LEARNING WITH LEARNING THE BASICS OF COST OF DISCUSSION AUTOMOTIVE AUTOMOTIVE DEPARTMENT OF CLASS X SMK PIRI SLEMAN EVEN SEMESTER OF STUDY 2013/2014

    Directory of Open Access Journals (Sweden)

    Deril Gusa Wijaya

    2014-12-01

    Based on the analysis of the results obtained the following results: (1 There is a positive and significant relationship between the attitude of Learning (X1 with Achievement Automotive Basics (Y; (2 There is a positive and significant relationship between Interests Learning (X2 with Achievement Automotive Basics (Y; (3 There is a positive and significant relationship Attitude Study (X1 and Interest in Learning (X2 with Achievement Automotive Basics (Y.

  6. Penerapan Pendekatan Contextual Teaching and Learning (Ctl) Dengan Model Problem Posing Untuk Meningkatkan Kualitas Pembelajaran Biologi Siswa Kelas X.2 SMA Negeri 2 Karanganyar Tahun Pelajaran 2011/2012

    OpenAIRE

    Suparmi, Suparmi; Suciati, Suciati; Harlita, Harlita

    2013-01-01

    – This research aims to improve low quality of biology in class X.2 SMA Negeri 2 Karanganyar in academic year 2011/2012. Learning considered by teacher's performance, utility of facilities in the classroom, classroom climate, student's scientific attitude, and student motivation of achievement applying for approach Contextual Teaching and Learning with Problem Posing model. This research was a classroom action research which and performed in three cycles. Each cycle consisted of 4 ...

  7. X-1E on Lakebed

    Science.gov (United States)

    1955-01-01

    The Bell Aircraft Corporation X-1E in 1955 on the Rogers Dry Lakebed near the NACA High-Speed Flight Station, Edwards, California. The X-1E was notable for being shorter, with a thinner wing than the X-1A, -B, and -D. Aerodynamic heating caused the ailerons, rudder, and elevators to remain unpainted throughout the X-1E's flight test program. When the ventral fins were added, they were left unpainted too. On August 31, 1956, the aircraft reached a top speed of 1,480 miles per hour (Mach 2.24). There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14

  8. A new species of Endecous Saussure, 1878 (Orthoptera, Gryllidae) from northeast Brazil with the first X1X20 chromosomal sex system in Gryllidae.

    Science.gov (United States)

    Zefa, Edison; Redü, Darlan Rutz; Da Costa, Maria Kátia Matiotti; Fontanetti, Carmem S; Gottschalk, Marco Silva; Padilha, Giovanna Boff; Fernandes e Silva, Anelise; Martins, Luciano De P

    2014-08-06

    In this paper we describe a new species of Luzarinae cricket collected from the cave "Gruta de Ubajara, municipality of Ubajara, State of Ceará, Brazil, highlighting phallic sclerites morphology and chromosome complement as diagnostic characters. We presented meiotic and mitotic characterization in order to define the karyotype with 2n = 12 + X1X2♂/12 + X1X1X2X2♀. This represents the first record of X1X20 chromosomal sex system in Gryllidae.

  9. Evaluation of integrals involving powers of (1-x2) and two associated Legendre functions or Gegenbauer polynomials

    International Nuclear Information System (INIS)

    Rashid, M.A.

    1984-08-01

    Integrals involving powers of (1-x 2 ) and two associated Legendre functions or two Gegenbauer polynomials are evaluated as finite sums which can be expressed in terms of terminating hypergeometric function 4 F 3 . The integrals which are evaluated are ∫sub(-1)sup(1)[Psub(l)sup(m)(x)Psub(k)sup(n)(x)]/[(1-x 2 )sup(p+1)]dx and ∫sub(-1)sup(1)Csub(l)sup(α)(x)Csub(k)sup(β)(x)[(1-x 2 )sup[(α+β-3)/2-p

  10. Modelling interstellar structures around Vela X-1

    Science.gov (United States)

    Gvaramadze, V. V.; Alexashov, D. B.; Katushkina, O. A.; Kniazev, A. Y.

    2018-03-01

    We report the discovery of filamentary structures stretched behind the bow-shock-producing high-mass X-ray binary Vela X-1 using the SuperCOSMOS H-alpha Survey and present the results of optical spectroscopy of the bow shock carried out with the Southern African Large Telescope. The geometry of the detected structures suggests that Vela X-1 has encountered a wedge-like layer of enhanced density on its way and that the shocked material of the layer partially outlines a wake downstream of Vela X-1. To substantiate this suggestion, we carried out 3D magnetohydrodynamic simulations of interaction between Vela X-1 and the layer for three limiting cases. Namely, we run simulations in which (i) the stellar wind and the interstellar medium (ISM) were treated as pure hydrodynamic flows, (ii) a homogeneous magnetic field was added to the ISM, while the stellar wind was assumed to be unmagnetized, and (iii) the stellar wind was assumed to possess a helical magnetic field, while there was no magnetic field in the ISM. We found that although the first two simulations can provide a rough agreement with the observations, only the third one allowed us to reproduce not only the wake behind Vela X-1, but also the general geometry of the bow shock ahead of it.

  11. Cray X1 Evaluation Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, J.S.

    2004-02-09

    On August 15, 2002 the Department of Energy (DOE) selected the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL) to deploy a new scalable vector supercomputer architecture for solving important scientific problems in climate, fusion, biology, nanoscale materials and astrophysics. ''This program is one of the first steps in an initiative designed to provide U.S. scientists with the computational power that is essential to 21st century scientific leadership,'' said Dr. Raymond L. Orbach, director of the department's Office of Science The Cray X1 is an attempt to incorporate the best aspects of previous Cray vector systems and massively-parallel-processing (MPP) systems into one design. Like the Cray T90, the X1 has high memory bandwidth, which is key to realizing a high percentage of theoretical peak performance. Like the Cray T3E, the X1 has a high-bandwidth, low-latency, scalable interconnect, and scalable system software. And, like the Cray SV1, the X1 leverages commodity off-the-shelf (CMOS) technology and incorporates non-traditional vector concepts, like vector caches and multi-streaming processors. In FY03, CCS procured a 256-processor Cray X1 to evaluate the processors, memory subsystem, scalability of the architecture, software environment and to predict the expected sustained performance on key DOE applications codes. The results of the micro-benchmarks and kernel benchmarks show the architecture of the Cray X1 to be exceptionally fast for most operations. The best results are shown on large problems, where it is not possible to fit the entire problem into the cache of the processors. These large problems are exactly the types of problems that are important for the DOE and ultra-scale simulation.

  12. Atmospheric chemistry of n-CxF2x+1CHO (x = 1, 2, 3, 4)

    DEFF Research Database (Denmark)

    Hurley, M. D.; Ball, J. C.; Wallington, T. J.

    2006-01-01

    Smog chamber/FTIR techniques were used to study the atmospheric fate of n-C(x)F(2)(x)(+1)C(O) (x = 1, 2, 3, 4) radicals in 700 Torr O(2)/N(2) diluent at 298 +/- 3 K. A competition is observed between reaction with O(2) to form n-C(x)()F(2)(x)()(+1)C(O)O(2) radicals and decomposition to form n-C(x...... to the atmospheric chemistry of n-C(x)F(2)(x)(+1)C(O) radicals and their possible role in contributing to the formation of perfluorocarboxylic acids in the environment....

  13. A status report on Cygnus X-1

    International Nuclear Information System (INIS)

    Eardley, D.M.; Lightman, A.P.; Shakura, N.I.; Shapiro, S.L.; Sunyaev, R.A.

    1978-01-01

    Detailed models of gas flow and X-ray production are discussed, but it is concluded that the strongest argument in favour of a black hole is that Cygnus X-1 is a compact object, and has a mass larger than that allowed for a neutron star or white dwarf. Evidence for the former feature is associated with the observation of very rapid time variability in X-rays. Evidence for the latter follows from a union of various types of observations of the Cyg X-1 star system, in which the visible star is the single-line spectroscopic binary HDE 226868, a normal supergiant. The evidence is reviewed under the following headings: geometry of the accretion flow; emission mechanism; time variability. (U.K.)

  14. Mass determination of Hercules X-1

    International Nuclear Information System (INIS)

    Bahcall, J.N.; Chester, T.J.

    1977-01-01

    The allowed range of masses for Hercules X-1 is calculated using the optical pulsation data of Middleditch and Nelson, a simple geometrical model for the optical pulsations, and Uhuru X-ray observations of the mass function and eclipse duration. For a specific set of assumptions, we obtain 0.6M/sub sun/ 1 < or =2.0M/sub sun/

  15. ORNL Cray X1 evaluation status report

    International Nuclear Information System (INIS)

    Agarwal, P.K.; Alexander, R.A.; Apra, E.; Balay, S.; Bland, A.S; Colgan, J.; D'Azevedo, E.F.; Dongarra, J.J.; Dunigan, T.H. Jr.; Fahey, M.R.; Fahey, R.A.; Geist, A.; Gordon, M.; Harrison, R.J.; Kaushik, D.; Krishnakumar, M.; Luszczek, P.; Mezzacappa, A.; Nichols, J.A.; Nieplocha, J.; Oliker, L.; Packwood, T.; Pindzola, M.S.; Schulthess, T.C.; Vetter, J.S.; White III, J.B.; Windus, T.L.; Worley, P.H.; Zacharia, T.

    2004-01-01

    On August 15, 2002 the Department of Energy (DOE) selected the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL) to deploy a new scalable vector supercomputer architecture for solving important scientific problems in climate, fusion, biology, nanoscale materials and astrophysics. ''This program is one of the first steps in an initiative designed to provide U.S. scientists with the computational power that is essential to 21st century scientific leadership,'' said Dr. Raymond L. Orbach, director of the department's Office of Science. In FY03, CCS procured a 256-processor Cray X1 to evaluate the processors, memory subsystem, scalability of the architecture, software environment and to predict the expected sustained performance on key DOE applications codes. The results of the micro-benchmarks and kernel bench marks show the architecture of the Cray X1 to be exceptionally fast for most operations. The best results are shown on large problems, where it is not possible to fit the entire problem into the cache of the processors. These large problems are exactly the types of problems that are important for the DOE and ultra-scale simulation. Application performance is found to be markedly improved by this architecture: - Large-scale simulations of high-temperature superconductors run 25 times faster than on an IBM Power4 cluster using the same number of processors. - Best performance of the parallel ocean program (POP v1.4.3) is 50 percent higher than on Japan s Earth Simulator and 5 times higher than on an IBM Power4 cluster. - A fusion application, global GYRO transport, was found to be 16 times faster on the X1 than on an IBM Power3. The increased performance allowed simulations to fully resolve questions raised by a prior study. - The transport kernel in the AGILE-BOLTZTRAN astrophysics code runs 15 times faster than on an IBM Power4 cluster using the same number of processors. - Molecular dynamics simulations related to the phenomenon of

  16. ORNL Cray X1 evaluation status report

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, P.K.; Alexander, R.A.; Apra, E.; Balay, S.; Bland, A.S; Colgan, J.; D' Azevedo, E.F.; Dongarra, J.J.; Dunigan Jr., T.H.; Fahey, M.R.; Fahey, R.A.; Geist, A.; Gordon, M.; Harrison, R.J.; Kaushik, D.; Krishnakumar, M.; Luszczek, P.; Mezzacappa, A.; Nichols, J.A.; Nieplocha, J.; Oliker, L.; Packwood, T.; Pindzola, M.S.; Schulthess, T.C.; Vetter, J.S.; White III, J.B.; Windus, T.L.; Worley, P.H.; Zacharia, T.

    2004-05-01

    On August 15, 2002 the Department of Energy (DOE) selected the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL) to deploy a new scalable vector supercomputer architecture for solving important scientific problems in climate, fusion, biology, nanoscale materials and astrophysics. ''This program is one of the first steps in an initiative designed to provide U.S. scientists with the computational power that is essential to 21st century scientific leadership,'' said Dr. Raymond L. Orbach, director of the department's Office of Science. In FY03, CCS procured a 256-processor Cray X1 to evaluate the processors, memory subsystem, scalability of the architecture, software environment and to predict the expected sustained performance on key DOE applications codes. The results of the micro-benchmarks and kernel bench marks show the architecture of the Cray X1 to be exceptionally fast for most operations. The best results are shown on large problems, where it is not possible to fit the entire problem into the cache of the processors. These large problems are exactly the types of problems that are important for the DOE and ultra-scale simulation. Application performance is found to be markedly improved by this architecture: - Large-scale simulations of high-temperature superconductors run 25 times faster than on an IBM Power4 cluster using the same number of processors. - Best performance of the parallel ocean program (POP v1.4.3) is 50 percent higher than on Japan s Earth Simulator and 5 times higher than on an IBM Power4 cluster. - A fusion application, global GYRO transport, was found to be 16 times faster on the X1 than on an IBM Power3. The increased performance allowed simulations to fully resolve questions raised by a prior study. - The transport kernel in the AGILE-BOLTZTRAN astrophysics code runs 15 times faster than on an IBM Power4 cluster using the same number of processors. - Molecular dynamics simulations

  17. 2x1 prototype plasma-electrode pockels cell (PEPC) for the National Ignition Facility

    International Nuclear Information System (INIS)

    Rhodes, M. A.

    1996-10-01

    A large aperture optical switch based on plasma electrode Pockels cell (PEPC) technology is an integral part of the National Ignition Facility (NIP) laser design. This optical switch will trap the input optical pulse in the NIF amplifier cavity for four gain passes and then switch the high-energy output optical pulse out of the cavity. The switch will consist of arrays of plasma electrode Pockels cells working in conjunction with thin-film, Brewster's angle polarizes. The 192 beams in the NIF will be arranged in 4x2 bundles. To meet the required beam-to-beam spacing within each bundle, we have proposed a NIF PEPC design based on a 4x1 mechanical module (column) which is in turn comprised of two electrically independent 2x1 PEPC units. In this paper, we report on the design a single 2x1 prototype module and experimental tests of important design issues using our single, 32 cm aperture PEPC prototype. The purpose the 2x1 prototype is to prove the viability of a 2x1 PEPC and to act, as an engineering test bed for the NIF PEPC design

  18. Gas phase UV and IR absorption spectra of CxF2x+1CHO (x=1-4)

    DEFF Research Database (Denmark)

    Hashikawa, Y; Kawasaki, M; Waterland, RL

    2004-01-01

    The UV and IR spectra of CxF2x+1 CHO (x = 1-4) were investigated using computational and experimental techniques. CxF2x+1CHO (x = 1-4) have broad UV absorption features centered at 300-310 nm. The maximum absorption cross-section increases significantly and shifts slightly to the red with increased...

  19. Thermal conductivities of (ZrxPu(1-x)/2Am(1-x)/2)N solid solutions

    International Nuclear Information System (INIS)

    Nishi, Tsuyoshi; Takano, Masahide; Akabori, Mitsuo; Arai, Yasuo

    2011-01-01

    The thermal conductivity of Zr-based transuranium (TRU) nitride solid solutions is important for designing subcritical cores in nitride-fueled ADS. Some results have been reported concerning the thermal conductivities of (Zr,Pu)N. However, there have been no experimental data on the thermal conductivities of Zr-based nitride solid solutions containing MA. In this study, the authors prepared sintered samples of (Zr x Pu (1-x)/2 Am (1-x)/2) N (x=0.0, 0.58, 0.80) solid solutions. The thermal diffusivity and heat capacity of (Zr x Pu (1-x)/2 Am (1-x)/2) N solid solutions were measured using a laser flash method and drop calorimetry, respectively. Thermal conductivities were determined from the measured thermal diffusivities, heat capacities and bulk densities over a temperature range of 473 to 1473 K. The thermal conductivities of (Zr 0.58 Pu 0.21 Am 0.21 )N and (Zr 0.80 Pu 0.10 Am 0.10 )N solid solutions were found to be higher than that of (Pu 0.5 Am 0.5 )N due to the high thermal conductivity of ZrN as the principal component, although they were lower than that of ZrN due to the impurifying effect of the transuranium elements. Thus, the thermal conductivities of (Zr x Pu (1-x)/2 Am (1-x)/2) N solid solutions increased with increasing ZrN concentration. Moreover, in order to help to promote the design study of nitride-fueled ADS, the thermal conductivity of the (Zr x Pu (1-x)/2 Am (1-x)/2) N solid solutions were fitted to an equation using the least squares method. (author)

  20. Identification of Human P2X1 Receptor-interacting Proteins Reveals a Role of the Cytoskeleton in Receptor Regulation*

    Science.gov (United States)

    Lalo, Ulyana; Roberts, Jonathan A.; Evans, Richard J.

    2011-01-01

    P2X1 receptors are ATP-gated ion channels expressed by smooth muscle and blood cells. Carboxyl-terminally His-FLAG-tagged human P2X1 receptors were stably expressed in HEK293 cells and co-purified with cytoskeletal proteins including actin. Disruption of the actin cytoskeleton with cytochalasin D inhibited P2X1 receptor currents with no effect on the time course of the response or surface expression of the receptor. Stabilization of the cytoskeleton with jasplakinolide had no effect on P2X1 receptor currents but decreased receptor mobility. P2X2 receptor currents were unaffected by cytochalasin, and P2X1/2 receptor chimeras were used to identify the molecular basis of actin sensitivity. These studies showed that the intracellular amino terminus accounts for the inhibitory effects of cytoskeletal disruption similar to that shown for lipid raft/cholesterol sensitivity. Stabilization of the cytoskeleton with jasplakinolide abolished the inhibitory effects of cholesterol depletion on P2X1 receptor currents, suggesting that lipid rafts may regulate the receptor through stabilization of the cytoskeleton. These studies show that the cytoskeleton plays an important role in P2X1 receptor regulation. PMID:21757694

  1. Immunocytochemical analysis of P2X2 in rat circumvallate taste buds.

    Science.gov (United States)

    Yang, Ruibiao; Montoya, Alana; Bond, Amanda; Walton, Jenna; Kinnamon, John C

    2012-05-23

    Our laboratory has shown that classical synapses and synaptic proteins are associated with Type III cells. Yet it is generally accepted that Type II cells transduce bitter, sweet and umami stimuli. No classical synapses, however, have been found associated with Type II cells. Recent studies indicate that the ionotropic purinergic receptors P2X2/P2X3 are present in rodent taste buds. Taste nerve processes express the ionotropic purinergic receptors (P2X2/P2X3). P2X2/P2X3(Dbl-/-) mice are not responsive to sweet, umami and bitter stimuli, and it has been proposed that ATP acts as a neurotransmitter in taste buds. The goal of the present study is to learn more about the nature of purinergic contacts in rat circumvallate taste buds by examining immunoreactivity to antisera directed against the purinergic receptor P2X2. P2X2-like immunoreactivity is present in intragemmal nerve processes in rat circumvallate taste buds. Intense immunoreactivity can also be seen in the subgemmal nerve plexuses located below the basal lamina. The P2X2 immunoreactive nerve processes also display syntaxin-1-LIR. The immunoreactive nerves are in close contact with the IP(3)R3-LIR Type II cells and syntaxin-1-LIR and/or 5-HT-LIR Type III cells. Taste cell synapses are observed only from Type III taste cells onto P2X2-LIR nerve processes. Unusually large, "atypical" mitochondria in the Type II taste cells are found only at close appositions with P2X2-LIR nerve processes. P2X2 immunogold particles are concentrated at the membranes of nerve processes at close appositions with taste cells. Based on our immunofluorescence and immunoelectron microscopical studies we believe that both perigemmal and most all intragemmal nerve processes display P2X2-LIR. Moreover, colloidal gold immunoelectron microscopy indicates that P2X2-LIR in nerve processes is concentrated at sites of close apposition with Type II cells. This supports the hypothesis that ATP may be a key neurotransmitter in taste transduction

  2. Immunocytochemical analysis of P2X2 in rat circumvallate taste buds

    Directory of Open Access Journals (Sweden)

    Yang Ruibiao

    2012-05-01

    Full Text Available Abstract Background Our laboratory has shown that classical synapses and synaptic proteins are associated with Type III cells. Yet it is generally accepted that Type II cells transduce bitter, sweet and umami stimuli. No classical synapses, however, have been found associated with Type II cells. Recent studies indicate that the ionotropic purinergic receptors P2X2/P2X3 are present in rodent taste buds. Taste nerve processes express the ionotropic purinergic receptors (P2X2/P2X3. P2X2/P2X3Dbl−/− mice are not responsive to sweet, umami and bitter stimuli, and it has been proposed that ATP acts as a neurotransmitter in taste buds. The goal of the present study is to learn more about the nature of purinergic contacts in rat circumvallate taste buds by examining immunoreactivity to antisera directed against the purinergic receptor P2X2. Results P2X2-like immunoreactivity is present in intragemmal nerve processes in rat circumvallate taste buds. Intense immunoreactivity can also be seen in the subgemmal nerve plexuses located below the basal lamina. The P2X2 immunoreactive nerve processes also display syntaxin-1-LIR. The immunoreactive nerves are in close contact with the IP3R3-LIR Type II cells and syntaxin-1-LIR and/or 5-HT-LIR Type III cells. Taste cell synapses are observed only from Type III taste cells onto P2X2-LIR nerve processes. Unusually large, “atypical” mitochondria in the Type II taste cells are found only at close appositions with P2X2-LIR nerve processes. P2X2 immunogold particles are concentrated at the membranes of nerve processes at close appositions with taste cells. Conclusions Based on our immunofluorescence and immunoelectron microscopical studies we believe that both perigemmal and most all intragemmal nerve processes display P2X2-LIR. Moreover, colloidal gold immunoelectron microscopy indicates that P2X2-LIR in nerve processes is concentrated at sites of close apposition with Type II cells. This supports the hypothesis

  3. Fretting wear characteristic tests of X2-GEN midgrid for SMART under a FIV rod trace

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Ho; Lee, Kang Hee; Kim, Jae Yong; Kim, Hyung Kyu [KAERI, Daejeon (Korea, Republic of)

    2011-12-15

    The KEPCO Nuclear Fuel Co. requested the fretting wear characteristic tests of a X2-GEN midgrid under a FIV rod trace at room temperature air. The following results were obtained for the fretting wear test. {center_dot} Fretting wear tests under a FIV rod trace Based on the result of the fretting wear tests of the X2-GEN and 17ACE7 1x1 mid-grid under a FIV rod trace, X2-GEN mid-grid showed a slightly severe wear volume rather than 17ACE7 spring. But, maximum wear depth shows an opposite behavior. This is due to spring shape effect. The fretting wear mechanisms at each mid-grid were influenced by each spring shape, that are depended on the different impacting behavior under a FIV rod motion. Up to 5x105 cycles, wear characteristics of each mid-grid shows a relatively similar wear rate. Consequently, it is necessary to further study for examining exact fretting wear behavior under a FIV rod tra

  4. BChPT x 1/Nc: masses and currents

    Energy Technology Data Exchange (ETDEWEB)

    Goity, Jose L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hampton Univ., Hampton, VA (United States); Fernando, Ishara P. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hampton Univ., Hampton, VA (United States)

    2018-04-01

    A summary of the implementation of the combined BChPT X 1/Nc expansion for three flavors is presented, along with its applications to the octet and decuplet baryon masses, SU(3) charges and axial couplings.

  5. Long-term studies with the Ariel 5 ASM. I - Hercules X-1, Vela X-1, and Centaurus X-3

    Science.gov (United States)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. A.

    1979-01-01

    Twelve hundred days of 3-6 keV X-ray data from Her X-1, Vela X-1, and Cen X-3 accumulated with the Ariel 5 All-Sky Monitor are interrogated. The binary periodicities of all three can be clearly observed, as can the 35 day variation of Her X-1, for which we can refine the period to 34.875 plus or minus 0.030 days. No such longer-term periodicity less than 200 days is observed from Vela X-1. The 26.6 days low-state recurrence period for Cen X-3 is not observed, but a 43.0 day candidate periodicity is found which may be consistent with the precession of an accretion disk in that system. The present results are illustrative of the long-term studies which can be performed on approximately 50 sources over a temporal base which will ultimately extend to at least 1800 days.

  6. Misura de Massa e Larghezza degli Stati $x_1$ e $x_2$ del Charmonio Formati in Interazioni $p - \\bar{p}$

    Energy Technology Data Exchange (ETDEWEB)

    Pallavicini, Marco [Univ. of Genoa (Italy)

    1995-01-01

    Oggetto di questa tesi è la misura di alcune caratteristiche fisiche ( massa, larghezza, e larghezza parziale in p - p) degli stati 3 Pi e 3 A del charmonio, - overo del sistema legato di un quark "charm" e del suo antiquark-, nell'ambito dell'esperimento E-760, installato nell'accumulatore di antiprotoni del Fermilab (U.S.A).

  7. Ethnomathematics: The use of multiple linier regression Y = b 1 X 1 + b 2 X 2 + e in traditional house construction Saka Roras in Songan Village

    Science.gov (United States)

    Darmayasa, J. B.; Wahyudin; Mulyana, T.

    2018-01-01

    Ethnomathematics may be the connecting bridge between culture and technology and arts. Therefore, the exploration of mathematics values that intersects with cultural anthropology should be significantly conducted. One case containing such issue is the construction of Traditional House of Saka Roras in Bali. Thus, this research aimed to explore the mathematic concept adopted in the construction of such traditional Bale (house) located in Songan Village, Kintamani, Bali. Specifically, this research also aimed to investigate the selection of linear regression coefficient for the saka (pillar) in the Bale. This research applied Embedded Mix-Method Design. Meanwhile, the data collection was conducted by interview, observation and measurement of pillars of 32 Bale Saka Roras. The result of this research revealed that the connection between the width and height of pillars was stated in the formula Y = 26,3 + 18,2X, where X acted as stimulus variable. The coefficient value amounted to 18.2 showed that most preceding architects in Songan Village were more likely to use 19 as the coefficient towards the pillar width than the other coefficients such as 17, 20 and 21 as mentioned in book/palm-leaf manuscript entitled Kosala-Kosali. The last but not least, the researchers also figured out that the pillar width depended on the length of the house-owner candidate’s index finger.

  8. X-1A in flight with flight data superimposed

    Science.gov (United States)

    1953-01-01

    This photo of the X-1A includes graphs of the flight data from Maj. Charles E. Yeager's Mach 2.44 flight on December 12, 1953. (This was only a few days short of the 50th anniversary of the Wright brothers' first powered flight.) After reaching Mach 2.44, then the highest speed ever reached by a piloted aircraft, the X-1A tumbled completely out of control. The motions were so violent that Yeager cracked the plastic canopy with his helmet. He finally recovered from a inverted spin and landed on Rogers Dry Lakebed. Among the data shown are Mach number and altitude (the two top graphs). The speed and altitude changes due to the tumble are visible as jagged lines. The third graph from the bottom shows the G-forces on the airplane. During the tumble, these twice reached 8 Gs or 8 times the normal pull of gravity at sea level. (At these G forces, a 200-pound human would, in effect, weigh 1,600 pounds if a scale were placed under him in the direction of the force vector.) Producing these graphs was a slow, difficult process. The raw data from on-board instrumentation recorded on oscillograph film. Human computers then reduced the data and recorded it on data sheets, correcting for such factors as temperature and instrument errors. They used adding machines or slide rules for their calculations, pocket calculators being 20 years in the future. Three second generation Bell Aircraft Corporations X-1s were built, though four were requested. They were the X-1A (48-1384); X-1B (48-1385); X-1C (canceled and never built); X-1D (48-1386). These aircraft were similar to the X-1s, except they were five feet longer, had conventional canopies, and were powered by Reaction Motors, Inc. XLR11-RM-5 rocket engines. The RM-5, like the previous engines, had no throttle and was controlled by igniting one or more of the four thrust chambers at will. The original program outline called for the X-1A and X-1B to be used for dynamic stability and air loads investigations. The X-1D was to be used

  9. X-1E launch from B-50 mothership

    Science.gov (United States)

    1950-01-01

    Beginning in 1946, two XS-1 experimental research aircraft (later redesignated X-1s) conducted pioneering tests at Muroc Army Air Field (now Edwards Air Force Base) in California to obtain flight data on conditions in the transonic speed range. These early tests culminated on October 14, 1947, in the first piloted flight faster than Mach 1.0, the speed of sound. During November, 1947, the Air Force authorized studies that led to a contract (W-33-038-ac-20062) with Bell Aircraft to build four (later three) improved X-1 aircraft (the X-1C being cancelled). Designated X-1A (#48-1384), X-1B (#48-1385), and X-1D (#48-1386), the airplanes were ready by late 1950. The aircraft were about five feet longer and 2,500 lbs. heavier than the original X-craft planes. They used the 8-percent wing like the earlier X-craft. The D-model had a low-pressure turbo-pump and the B model was fitted with a prototype hydrogen peroxide reaction control system for later aircraft to use in exoatmospheric research flights. Access was through a lift-off canopy. The planes were finished in their bare metal color and white. The X-1D was ready first, but on what was intended to be its second flight (August 22, 1951) it was jettisoned and crashed at Muroc after an aerial explosion while still mated to its mother (B-50A [#46-006A]) ship. The long-delayed X-1 #3 airplane with the turbine pump was finally completed for the NACA in 1951. It made its first glide flight on July 20, 1951, with NACA pilot Joseph Cannon. Its second and final captive flight was on November 9, 1951. It was destroyed on the ground by an explosion and fire along with its B-50A mother ship while attempting to jettison fuel. The X-1A arrived at Muroc in January, 1953 and had its first powered flight on February 21, 1953. On December 8, 1953 with Yeager as pilot, the aircraft investigated high-speed stability and control issues. The X-1A was turned over to the NACA, but was lost to aerial explosion on August 8, 1955, shortly before

  10. Phase transition in the (Li 0.5-( x/2) K 0.5-( x/2) Cs x) 2SO 4 system

    Science.gov (United States)

    Hamed, A. E.; El-Aziz, Y. M. Abd.; Madi, N. K.; Kassem, M. E.

    1995-12-01

    Phase transition in the (Li 0.5-( x/2) K 0.5-( x/2) Cs x) 2SO 4 system was studied by measuring the specific heat at constant pressure, C p, as a function of temperature in the temperature range 300-800 K. For non-zero values of X ( X = 0.2%, 0.5%, 1% and 2%) the critical behaviour of the phase transition was found to change considerably compared with that of X = 0 or pure LiKSO 4. The observed change in the phase transition with increase of Cs 2SO 4 content ( X) was accompanied by a decrease in the thermodynamic parameters: the value of the specific heat at the transition point (Δ C P) max, the transition temperature, T1, and the value of the energy of ordering. The results were interpreted within the Landau thermodynamic theory of the phase transition.

  11. Is Cygus X-1 a chaotic dynamical system?

    International Nuclear Information System (INIS)

    Unno, Wasaburo; Yoneyama, Tadaoki; Urata, Kenji; Masaki, Isao; Kondo, Masa-aki; Inoue, Hajime.

    1990-01-01

    X-ray data of Cyg X-1 observed by the Tenma satellite were analyzed to determine whether Cyg X-1 is a chaotic dynamical system of low dimension. Since Poisson noise disturbs the determination of the attractor dimension of the system, comparative studies were carried out for the Cyg X-1 data relative to artificial data of purely stochastic Poisson noise and to a Lorenz attractor plus noise. The attractor dimension was searched using trajectories of time series data in phase space, the dimension of which was varied up to 21. The relation between the attractor dimension and the phase-space dimension for the Cyg X-1 data starts to deviate from that of noise data from a phase-space dimension of about 7, showing the presence of an attractor with a dimension of about 7 or less. Though three positive Lyapunov exponents were calculated, they are too small (∼10 -2 ) to prove with certainty that the Cyg X-1 attractor should be a strange attractor. (author)

  12. Water Induced Surface Reconstruction of the Oxygen (2x1) covered Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Sabine; Cabrera-Sanfelix, Pepa; Stass, Ingeborg; Sanchez-Portal, Daniel; Arnau, Andres; Salmeron, Miquel

    2010-08-06

    Low temperature scanning tunneling microscopy (STM) and density functional theory (DFT) were used to study the adsorption of water on a Ru(0001) surface covered with half monolayer of oxygen. The oxygen atoms occupy hcp sites in an ordered structure with (2x1) periodicity. DFT predicts that water is weakly bound to the unmodified surface, 86 meV compared to the ~;;200 meV water-water H-bond. Instead, we found that water adsorption causes a shift of half of the oxygen atoms from hcp sites to fcc sites, creating a honeycomb structure where water molecules bind strongly to the exposed Ru atoms. The energy cost of reconstructing the oxygen overlayer, around 230 meV per displaced oxygen atom, is more than compensated by the larger adsorption energy of water on the newly exposed Ru atoms. Water forms hydrogen bonds with the fcc O atoms in a (4x2) superstructure due to alternating orientations of the molecules. Heating to 185 K results in the complete desorption of the water layer, leaving behind the oxygen honeycomb structure, which is metastable relative to the original (2x1). This stable structure is not recovered until after heating to temperatures close to 260K.

  13. Low energy gamma rays emitted by Sco X-1

    International Nuclear Information System (INIS)

    Bui-Van, A.; Martin, I.M.

    1975-01-01

    Sco X-1 was observed on a balloon flight launched from Sao Jose dos Campos, S.P., Brazil, on December 20, 1974. A 3 sigma excess of the raw count rate, covering the energy range 0.2 to 5.0 MeV, was found during the transit of the source. A power-law spectrum provided an adequate fit to the data. Although it was difficult to separate the contribution of the universal diffuse component, the existence of hard-component in the spectrum of Sco X-1 could indicate the presence of matter hotter than previously deduced from soft X-ray observations [pt

  14. Low-energy gamma rays from Cygnus X-1

    International Nuclear Information System (INIS)

    Roques, J.P.; Mandrou, P.; Lebrun, F.; Paul, J.

    1985-08-01

    Cyg X-1 was observed by the CESR balloon borne telescope OPALE, in June 1976. The high-energy spectrum of the source, which was in its ''superlow state'', was seen to extend well beyond 1 MeV. In this paper, the observed low-energy γ-ray component of Cyg X-1 is compared with the predictions of recent models involving accretion onto a stellar black hole, and including a possible contribution from the pair-annihilation 511 keV γ-ray line

  15. Tests for homogeneity for multiple 2 x 2 contingency tables

    International Nuclear Information System (INIS)

    Carr, D.B.

    1986-01-01

    Frequently data are described by 2 x 2 contingency tables. For example, each 2 x 2 table arises from two dichotomous classifications such as control/treated and respond/did not respond. Multiple 2 x 2 tables result from stratifying the observational units on the basis of other characteristics. For example, stratifying by sex produces separate 2 x 2 tables for males and females. From each table a measure of difference between the response rates for the control and the treated groups is computed. The researcher usually wants to know if the response-rate difference is zero for each table. If the tables are homogeneous, the researcher can generalize from a statement concerning an average to a statement concerning each table. If tables are not homogeneous, homogeneous subsets of the tables should be described separately. This paper presents tests for homogeneity and illustrates their use. 11 refs., 6 tabs

  16. A Result on a 2x2 Survival Experiment

    National Research Council Canada - National Science Library

    Arami, Ramin

    1997-01-01

    .... The proposed model is a combination of Cox's proportional hazards model and ANOVA model. The existence of a solution to the marginal likelihood function is examined for the case of 2x2 two-way classification...

  17. Polycrystalline (TbXY1-X)2O3 Faraday rotator.

    Science.gov (United States)

    Ikesue, Akio; Aung, Yan Lin; Makikawa, Shinji; Yahagi, Akira

    2017-11-01

    We have succeeded for the first time in synthesizing an optical grade (Tb X Y 1-X ) 2 O 3 (X=0.5-1.0) ceramic Faraday rotator, which greatly exceeds the basic characteristics of the commercial terbium gallium garnet (TGG) (Tb 3 Ga 5 O 12 ) crystal. The Faraday rotation angle increased as the Tb concentration increased, and the Verdet constant increased from 2.1 (82  rad T -1  m -1 at X=0.5) to 3.8 times (154  rad T -1  m -1 at X=1.0) than the TGG single crystal, which is regarded as highest class. Therefore, it is possible to minimize the Faraday rotator length and the magnet in building an optical isolator. It was also confirmed that its optical quality was very comparable to the commercial TGG crystal.

  18. P2X1 receptors and the endothelium

    Directory of Open Access Journals (Sweden)

    LS Harrington

    2005-03-01

    Full Text Available Adenosine triphosphate (ATP is now established as a principle vaso-active mediator in the vasculature. Its actions on arteries are complex, and are mediated by the P2X and P2Y receptor families. It is generally accepted that ATP induces a bi-phasic response in arteries, inducing contraction via the P2X and P2Y receptors on the smooth muscle cells, and vasodilation via the actions of P2Y receptors located on the endothelium. However, a number of recent studies have placed P2X1 receptors on the endothelium of some arteries. The use of a specific P2X1 receptor ligand, a, b methylene ATP has demonstrated that P2X1 receptors also have a bi-functional role. The actions of ATP on P2X1 receptors is therefore dependant on its location, inducing contraction when located on the smooth muscle cells, and dilation when expressed on the endothelium, comparable to that of P2Y receptors.

  19. RXTE detects X-ray bursts from Circinus X-1

    NARCIS (Netherlands)

    Linares, M.; Soleri, P.; Watts, A.; Altamirano, D.; Armas-Padilla, M.; Cavecchi, Y.; Degenaar, N.; Kalamkar, M.; Kaur, R.; van der Klis, M.; Patruno, A.; Wijnands, R.; Yang, Y.; Casella, P.; Rea, N.

    After the recent report of X-ray re-brightening (ATel #2608), RXTE has observed the peculiar neutron star X-ray binary Cir X-1 eleven times during the last two weeks (May 11-25, 2010). We report the detection of nine X-ray bursts in RXTE-PCA data, 25 years after the first -and the only previous-

  20. THE ROTATION PERIOD OF HD-77581 (VELA X-1)

    NARCIS (Netherlands)

    ZUIDERWIJK, EJ

    The rotation period of HD 77581, supergiant primary in the X-ray binary Vela X-1, is determined from an analysis of selected absorption line profiles. The rotation rate determined from He I line profiles is 0.67 +/- 0.04 times that of the binary angular velocity, corresponding to a rotation velocity

  1. Measuring a truncated disk in Aquila X-1

    DEFF Research Database (Denmark)

    King, Ashley L.; Tomsick, John A.; Miller, Jon M.

    2016-01-01

    We present NuSTAR and Swift observations of the neutron star Aquila X-1 during the peak of its 2014 July outburst. The spectrum is soft with strong evidence for a broad Fe Kα line. Modeled with a relativistically broadened reflection model, we find that the inner disk is truncated with an inner r...

  2. The temporal behaviour of Taurus X-1 (the Crab Nebula)

    International Nuclear Information System (INIS)

    Davison, P.J.N.

    1975-01-01

    Copernicus data on Taurus X-1 and the Crab pulsar extending over a 2 1/2-yr period indicate that under normal conditions the source has a flux that is constant to within 2.5 per cent at the 90 per cent confidence level. The pulsed/total flux ratio also shows no significant changes during the same time. (author)

  3. Hard X-ray observation of HER X-1

    Energy Technology Data Exchange (ETDEWEB)

    Ubertini, P.; Bazzano, A.; La Padula, C.; Polcaro, V.F.; Vialetto, G. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale); Manchanda, R.K. (Tata Inst. of Fundamental Research, Bombay (India))

    1981-01-01

    A hard X-rays (15-170 KeV) measurement of the spectrum of Her X-1, during a mid turn-on is presented. The presence of an emission line at about 53 KeV during the mid-on state is confirmed by the present measure.

  4. Hard X-ray observation of HER X-1

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; La Padula, C.; Polcaro, V.F.; Vialetto, G.

    1981-01-01

    A hard X-rays (15-170 KeV) measurement of the spectrum of Her X-1, during a mid turn-on is presented. The presence of an emission line at about 53 KeV during the mid-on state is confirmed by the present measure. (orig.)

  5. Response of the middle atmosphere to Sco X-1

    Science.gov (United States)

    Goldberg, R. A.; Barcus, J. R.; Mitchell, J. D.

    1985-10-01

    On the night of Mar. 9, 1983 (UT) at Punta Lobos Launch Site, Peru (12.5 deg S, 76.8 deg W, magnetic dip -0.7 deg), a sequence of sounding rockets was flown to study the electrical structure of the equatorial middle atmosphere and to evaluate perturbations on this environment induced by the X-ray star Sco X-1. The rocket series was anchored by two Nike Orion payloads (31.032 and 31.033) which were launched at 0327 and 0857 UT, near Sco X-1 star-rise and after it had attained an elevation angle of 70 deg E. An enhanced flux of X-rays was observed on the second Nike Orion flight (31.033). This increase is directly attributed to Sco X-1, both from the spectral properties of the measured X-ray distribution and by spatial information acquired from a spinning X-ray detector during the upleg portion of the 31.033 flight. Simultaneously, a growth in ion conductivity and density was seen to occur in the lower mesosphere between 60 and 80 km on the second flight, specifically in the region of maximum energy deposition by the Sco X-1 X-rays. The results imply the presence of a significant number of ionized heavy constituents within the lower mesosphere, with masses possibly in the submacroscopoic range.

  6. Cygnus X-1: Discovery of variable circular polarization

    International Nuclear Information System (INIS)

    Michalsky, J.J.; Swedlund, J.B.; Stokes, R.A.

    1975-01-01

    HDE 226868, the optical counterpart of Cyg X-1, has been observed for circular polarization during 1974. Observations in five colors suggest that circular polarization results from an interstellar effect. Measurements of the blue polarization reveal circular polarization variations synchronous with the 5)./sub /6 orbital period. The circular polarization variation appears to be similar to the blue intensity variation

  7. Formation of Nitriles in the Interstellar Medium via Reactions of Cyano Radicals, CN(X2Σ+), with Unsaturated Hydrocarbons

    Science.gov (United States)

    Balucani, N.; Asvany, O.; Huang, L. C. L.; Lee, Y. T.; Kaiser, R. I.; Osamura, Y.; Bettinger, H. F.

    2000-12-01

    Crossed molecular beam experiments of cyano radicals, CN(X2Σ+, ν=0), in their electronic and vibrational ground state reacting with unsaturated hydrocarbons acetylene, C2H2(X1Σ+g), ethylene, C2H4(X1Ag), methylacetylene, CH3CCH(X1A1), allene, H2CCCH2(X1A1), dimethylacetylene, CH3CCCH3(X1A1'), and benzene, C6H6 (X1A1g), were performed at relative collision energies between 13.3 and 36.4 kJ mol-1 to unravel the formation of unsaturated nitriles in the outflows of late-type AGB carbon stars and molecular clouds. In all reactions, the CN radical was found to attack the π electron density of the hydrocarbon molecule with the radical center located at the carbon atom; the formation of an initial addition complex is a prevalent pathway on all the involved potential energy surfaces. A subsequent carbon-hydrogen bond rupture yields the nitriles cyanoacetylene, HCCCN (X1Σ+), vinylcyanide, C2H3CN (X1A'), 1-methylcyanoacetylene, CH3CCCN (X1A1), cyanoallene, H2CCCH(CN) (X1A'), 3-methylcyanoacetylene, HCCCH2CN(X1A'), 1,1-cyanomethylallene, H2CCC(CN)(CH3) (X1A'), and cyanobenzene, C6H5CN (X1A1). In case of acetylene and ethylene, a second reaction channel involves a [1, 2]-H atom shift in the initial HCCHCN and H2CCH2CN collision complexes prior to a hydrogen atom release to form cyanoacetylene, HCCCN (X1Σ+), and vinylcyanide, C2H3CN (X1A'). Since all these radical-neutral reactions show no entrance barriers, have exit barriers well below the energy of the reactant molecules, and are exothermic, the explicit identification of this CN versus H atom exchange pathway under single collision conditions makes this reaction class a compelling candidate to synthesize unsaturated nitriles in interstellar environments holding temperatures as low as 10 K. This general concept makes it even feasible to predict the formation of nitriles once the corresponding unsaturated hydrocarbons are identified in the interstellar medium. Here HCCCN, C2H3CN, and CH3CCCN have been already observed

  8. INFLUENCE OF PARENTS' SOCIO-ECONOMIC STATUS AND VOCATIONAL LEARNING MOTIVATION TO LEARNING ACHIEVEMENT IN THE LESSON OF CHASSIS AND POWER TRANSDUCTOR FOR XII GRADE STUDENTS OF LIGHT VIHICLE ENGINEERING DEPARTMENT OF SMK PIRI 1 YOGYAKARTA IN ACADEMIC YEAR 2013/2014

    Directory of Open Access Journals (Sweden)

    Indra Tri Setyawan

    2014-06-01

    Full Text Available The purpose of the study is to find the influence of parents’ socio-economic status and vocational learning motivation to learning achievement in the lesson of chassis and power transductor for XII grade students of SMK PIRI 1 Yogyakarta in the academic year 2013/2014. This research includes ex-post facto research conducted on the population 129 students with the sample 98 students. Data collection techniques in this research uses questionnaire instrument techniques for variable of parents’ socio-economic status and vocational learning motivation whereas documentation instrument techniques uses for variable of learning achievement the lesson of chassis and power transductor. Questionnaire was tested on 25 respondents. Data analysis techniques uses partial correlation analysis and regression analysis were preceded by prerequisite test that are normality test, linearity and multikolonieritas. The results of the data analysis is (1 parents’ socio-economic status (X1 influential positive and significant on learning achievement in the lesson of chassis and power transductor, (2 vocational learning motivation (X2 influential positive and significant on learning achievement in the lesson of chassis and power transductor, (3 parents’ socio-economic status (X1 and vocational learning motivation (X2 are jointly have positive and significant effect on learning achievement in the lesson of chassis and power transductor. Positive means that the higher the value of X1 and X2, the higher the value of Y, and vice versa. Thus, the socio-economic status of parents and the motivation to study vocational subjects affecting learning achievement the lesson of chassis and power transductor XII grade students of SMK PIRI 1 Yogyakarta in the academic year 2013/2014.

  9. Hydrogen absorption in Zr(Alsub(x)Bsub(1-x))2 (B = Fe, Co) Laves phase compounds

    International Nuclear Information System (INIS)

    Jacob, I.; Shaltiel, D.

    1978-01-01

    The hydrogen absorption capacity of the systems Zr(Alsub(x)Fesub(1-x)) 2 and Zr(Alsub(x)Cosub(1-x)) 2 (0 = 2 (A = V, Cr, Mn; B = Fe, Co; 0 =< x =< 1). The maximum hydrogen content in both systems is achieved for x approximately 2/12 at 40 atm and 80 K. Further increase of the Al content leads, however, to a steep decrease in the hydrogen capacity. This general behaviour is well described by a phenomenological model, recently proposed by the authors, thus supporting the importance of short-range neighbouring effects for the hydrogen absorption capacity. The influence of Al on the hydrogen sorption properties in different intermetallic compounds is discussed. (author)

  10. Hard X-ray spectrum of Her X-1

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; La Padula, C.D.; Polcaro, V.F.

    1981-01-01

    The results of a balloon borne hard X-ray observation of Her X-1 is presented. The experiment, released from the base of Hyderabad (India) the 19th April 1980, was a collaboration between the Istituto di Astrofisica Spaziale (Italy) and the TIFR (India). The data obtained are compatible with a thermal emission at low energy with a strong emission line overimposed on the continuum around 50-60 keV

  11. Response of the middle atmosphere to Sco X-1

    International Nuclear Information System (INIS)

    Goldberg, R.A.; Barcus, J.R.; Mitchell, J.D.

    1985-01-01

    On the night of 9 March 1983 (UT) at Punta Lobos Launch Site, Peru, a sequence of sounding rockets was flown to study the electrical structure of the equatorial middle atmosphere and to evaluate perturbations on this environment induced by the X-ray star Sco X-1. The rocket series was anchored by two Nike Orion payloads which were launched at 0327 and 0857 UT, near Sco X-1 star-rise and after it had attained an elevation angle of 70 deg E. Each of these payloads carried instrumentation during parachute descent to measure X-ray and electron fluxes, ion density, conductivity and mobility, and in situ electric fields. In addition, several smaller payloads capable of measuring the atmospheric electrical parameters were launched at times interspersed among the large rockets. An enhanced flux of X-rays was observed on the second Nike Orion flight. This increase is directly attributed to Sco X-1, both from the spectral properties of the measured X-ray distribution and by spatial information acquired from a spinning X-ray detector during the upleg portion of the 31.033 flight. Simultaneously, a growth in ion conductivity and density was seen to occur in the lower mesosphere between 60 and 80 km on the second flight. The results are discussed. (author)

  12. The Si(100)-Sb 2x1 and Ge(100) 2x1 surfaces: A multi-technique study

    International Nuclear Information System (INIS)

    Richter, M.

    1993-08-01

    The electronic and geometric structures of the clean and Sb terminated Si(100)2x1 and Ge(100)-2x1 surfaces have been investigated using a multi-technique approach. Low energy electron diffraction (LEED), scanning tunneling microscopy (STM), surface extended X-ray absorption fine structure (SEXAFS) spectroscopy and angle-integrated core-level photoemission electron spectroscopy (PES) were employed to measure the surface symmetry, defect structure, relevant bond lengths, atomic coordination and electronic structure. By employing a multi-technique approach, it is possible to correlate changes in the geometric structure to specific features of the core-level lineshape of the substrate. This allows for the assignment of components of the core-level lineshape to be assigned to specific surface and near-surface atoms

  13. Nucleotide sequence of pOLA52: a conjugative IncX1 plasmid from Escherichia coli which enables biofilm formation and multidrug efflux

    DEFF Research Database (Denmark)

    Norman, Anders; Hansen, Lars H.; She, Qunxin

    2008-01-01

    . The plasmid was also classified as IncX1 with incompatibility testing. The conjugal transfer and plasmid maintenance regions of pOLA52 therefore seem to represent IncX1 orthologues of the well-characterized IncX2 plasmid R6K. Sequence homology searches in GenBank also suggested a considerably higher...... of type 3 fimbriae (mrkABCDF). The plasmid was found to be 51,602 bp long with 68 putative genes. About half of the plasmid constituted a conserved IncX1-type backbone with predicted regions for conjugation, replication and partitioning, as well as a toxin/antitoxin (TA) plasmid addiction system...... prevalence of IncX1 group plasmids than IncX2. The 21 kb 'genetic load' region of pOLA52 was shown to consist of a mosaic, among other things a fragmented Tn3 transposon encoding ampicillin resistance. Most notably the oqxAB and mrkABCDF cassettes were contained within two composite transposons (Tn6010...

  14. Comprehensive spectral analysis of Cyg X-1 using RXTE data

    International Nuclear Information System (INIS)

    Shahid, Rizwan; Jaaffrey, S. N. A.; Misra, Ranjeev

    2012-01-01

    We analyze a large number (> 500) of pointed Rossi X-Ray Timing Explorer (RXTE) observations of Cyg X-1 and model the spectrum of each one. A subset of the observations for which there is a simultaneous reliable measure of the hardness ratio by the All Sky Monitor shows that the sample covers nearly all the spectral shapes of Cyg X-1. Each observation is fitted with a generic empirical model consisting of a disk black body spectrum, a Comptonized component whose input photon shape is the same as the disk emission, a Gaussian to represent the iron line and a reflection feature. The relative strength, width of the iron line and the reflection parameter are in general correlated with the high energy photon spectral index Γ. This is broadly consistent with a geometry where for the hard state (low Γ ∼ 1.7) there is a hot inner Comptonizing region surrounded by a truncated cold disk. The inner edge of the disk moves inwards as the source becomes softer till finally in the soft state (high Γ > 2.2) the disk fills the inner region and active regions above the disk produce the Comptonized component. However, the reflection parameter shows non-monotonic behavior near the transition region (Γ ∼ 2), which suggests a more complex geometry or physical state of the reflector. In addition, the inner disk temperature, during the hard state, is on average higher than in the soft one, albeit with large scatter. These inconsistencies could be due to limitations in the data and the empirical model used to fit them. The flux of each spectral component is well correlated with Γ, which shows that unlike some other black hole systems, Cyg X-1 does not show any hysteresis behavior. In the soft state, the flux of the Comptonized component is always similar to the disk one, which confirms that the ultra-soft state (seen in other brighter black hole systems) is not exhibited by Cyg X-1. The rapid variation of the Compton amplification factor with Γ naturally explains the absence of

  15. Long term variability of HDE 226868 = Cygnus X-1

    International Nuclear Information System (INIS)

    Liller, W.

    1976-01-01

    Investigation of blue-sensitive photographs of HDE 226868 = Cygnus X-1 reveal no (+-0.06 mag) long-term changes in brightness since the beginning of the century nor any abrupt intensity changes similar to what has been observed at x-ray and radio frequencies. From the double sinusoidal fluctuation with 5.6 day period, an attempt is made to derive a more precise value for the orbital period, but problems are encountered and discussed. There exists evidence that the amplitude of the orbital fluctuations is increasing slowly with time

  16. Multimodal Task-Driven Dictionary Learning for Image Classification

    Science.gov (United States)

    2015-12-18

    recognition, multi-view face recognition, multi-view action recognition, and multimodal biometric recognition. It is also shown that, compared to the...improvement in several multi-task learning applications such as target classification, biometric recognitions, and multiview face recognition [12], [14], [17...relevant samples from other modalities for a given unimodal query. However, α1 α2 …αS D1 … Index finger Thumb finger … Iris x1 x2 xS D2 DS … … … J o in

  17. A NICER Look at the Aql X-1 Hard State

    Science.gov (United States)

    Bult, Peter; Arzoumanian, Zaven; Cackett, Edward M.; Chakrabarty, Deepto; Gendreau, Keith C.; Guillot, Sebastien; Homan, Jeroen; Jaisawal, Gaurava K.; Keek, Laurens; Kenyon, Steve; Lamb, Frederick K.; Ludlam, Renee; Mahmoodifar, Simin; Markwardt, Craig; Miller, Jon M.; Prigozhin, Gregory; Soong, Yang; Strohmayer, Tod E.; Uttley, Phil

    2018-05-01

    We report on a spectral-timing analysis of the neutron star low-mass X-ray binary (LMXB) Aql X-1 with the Neutron Star Interior Composition Explorer (NICER) on the International Space Station (ISS). Aql X-1 was observed with NICER during a dim outburst in 2017 July, collecting approximately 50 ks of good exposure. The spectral and timing properties of the source correspond to that of a (hard) extreme island state in the atoll classification. We find that the fractional amplitude of the low-frequency (soft thermal emission and the power-law emission. Additionally, we measure hard time lags, indicating the thermal emission at 0.5 keV leads the power-law emission at 10 keV on a timescale of ∼100 ms at 0.3 Hz to ∼10 ms at 3 Hz. Our results demonstrate that the thermal emission in the hard state is intrinsically variable, and is driving the modulation of the higher energy power-law. Interpreting the thermal spectrum as disk emission, we find that our results are consistent with the disk propagation model proposed for accretion onto black holes.

  18. The nature of the companion star in Circinus X-1

    Science.gov (United States)

    Johnston, Helen M.; Soria, Roberto; Gibson, Joel

    2016-02-01

    We present optical spectra and images of the X-ray binary Circinus X-1. The optical light curve of Cir X-1 is strongly variable, changing in brightness by 1.2 mag in the space of four days. The shape of the light curve is consistent with that seen in the 1980s, when the X-ray and radio counterparts of the source were at least ten times as bright as they are currently. We detect strong, variable H α emission lines, consisting of multiple components which vary with orbital phase. We estimate the extinction to the source from the strength of the diffuse interstellar bands and the Balmer decrement; the two methods give AV = 7.6 ± 0.6 mag and AV > 9.1 mag, respectively. The optical light curve can be modelled as arising from irradiation of the companion star by the central X-ray source, where a low-temperature star fills its Roche lobe in an orbit of moderate eccentricity (e ˜ 0.4). We suggest that the companion star is overluminous and underdense, due to the impact of the supernova which occurred less than 5000 yr ago.

  19. Scorpius X-1 - an evolving double radio source

    International Nuclear Information System (INIS)

    Geldzahler, B.J.; Fomalont, E.B.; National Radio Astronomy Observatory, Charlottesville, VA)

    1986-01-01

    The radio emission from Sco X-1 has been monitored with the VLA over a 5 yr period with 0.4 arcsec resolution at 4.85 GHz. The source contains three components: an unresolved radio core coincident with the stellar binary system; an unresolved lobe northeast of the core; and an extended lobe southwest of the core. All radio components are approximately comoving with the binary system and are thus undoubtedly associated with it. The northeast lobe is moving away from the core at a rate of 0.013-0.017 arcsec/yr, which corresponds to a velocity of 31-41 km/sec, assuming a distance of 500 pc to Sco X-1. The relative velocity of a hot spot in the southwest lobe with respect to the core is less than 70 km/sec. The flux density in the lobes appears to vary by about 20 percent over time scales of 1 yr, and the variations between the lobes may be correlated. The twin-exhaust beam model where energy is transported from the core to the lobes in narrow beams is the most acceptable model for the evolution of the source. However, interstellar density (greater than 0.6/cu cm) is needed to restrain the velocity of the northeast lobe (presumably the working surface of the beam). 16 references

  20. Broad-Band Spectroscopy of Hercules X-1 with Suzaku

    Science.gov (United States)

    Asami, Fumi; Enoto, Teruaki; Iwakiri, Wataru; Yamada, Shin'ya; Tamagawa, Toru; Mihara, Tatehiro; Nagase, Fumiaki

    2014-01-01

    Hercules X-1 was observed with Suzaku in the main-on state from 2005 to 2010. The 0.4- 100 keV wide-band spectra obtained in four observations showed a broad hump around 4-9 keV in addition to narrow Fe lines at 6.4 and 6.7 keV. The hump was seen in all the four observations regardless of the selection of the continuum models. Thus it is considered a stable and intrinsic spectral feature in Her X-1. The broad hump lacked a sharp structure like an absorption edge. Thus it was represented by two different spectral models: an ionized partial covering or an additional broad line at 6.5 keV. The former required a persistently existing ionized absorber, whose origin was unclear. In the latter case, the Gaussian fitting of the 6.5-keV line needs a large width of sigma = 1.0-1.5 keV and a large equivalent width of 400-900 eV. If the broad line originates from Fe fluorescence of accreting matter, its large width may be explained by the Doppler broadening in the accretion flow. However, the large equivalent width may be inconsistent with a simple accretion geometry.

  1. On the parameters of the system Cyg X-1

    International Nuclear Information System (INIS)

    Sokolov, V.V.

    1987-01-01

    Estimations are given of the mass of the supergiant HDE 226868 in the system Cyg X-1 which are made on the basis of interpretation of spectroscopic observations by means of the model-atmosphere method. The importance is pointed out of accounting for deviations from LTE in calculations of equivalent widths and profiles of hydrogen lines by which the acceleration of gravity force on the surface of the optical star of system is determined. Supergiant mass determined in that way turns out to be M*=(16±3)M sun . Provided the zone of formation of the emission He II λ4686 A must be localized near the supergiant surface, the least value of inclination of system orbit plane is estimated: i>or approx. 35 deg. The possibility is pointed out of variability of equivalent widths of He II emission λ4686 A, which is connected with eclipse of the ''spot'', i.e. of area of localization of this emission. It is noted that for large angles (i>or approx. 35 deg) of orbit inclinaion, the mass of the degenerate star in the system Cyg X-1 does not exceed 10 M sun

  2. Generalised Wigner surmise for (2 X 2) random matrices

    International Nuclear Information System (INIS)

    Chau Huu-Tai, P.; Van Isacker, P.; Smirnova, N.A.

    2001-01-01

    We present new analytical results concerning the spectral distributions for (2 x 2) random real symmetric matrices which generalize the Wigner surmise. The study of the statistical properties of spectra of realistic many-body Hamiltonians requires consideration of a random matrix ensemble whose elements are not independent or whose distribution is not invariant under orthogonal transformation of a chosen basis. In this letter we have concentrated on the properties of (2 x 2) real symmetric matrices whose elements are independent Gaussian variables with zero means but do not belong to the GOE. We have derived the distribution of eigenvalues for such a matrix, the nearest-neighbour spacing distribution which generalizes the Wigner surmise and we have calculated some important moments. (authors)

  3. Eesti filmid "30 minutit vaikust" ja "5 x 2" Sõpruses

    Index Scriptorium Estoniae

    2005-01-01

    Sõpruse ekraanile jõuab kaks kodumaist filmitööd: Ove Mustingu lühifilm "30 minutit vaikust" ning Märt Sildvee dokumentaalfilm "Parema elu nimel". Viga pealkirjas. "5 x 2" on prantsuse režissööri F. Ozoni linateos ning selle näitamine järgneb O. Mustingu filmile. Korrektne pealkiri oleks: Eesti filmid "30 minutit vaikust" ja "Parema elu nimel" Sõpruses

  4. The WA105-3x1x1 m3 dual phase LAr-TPC demonstrator

    CERN Document Server

    Murphy, Sebastien

    2016-11-15

    The dual phase Liquid Argon Time Projection Chamber (LAr TPC) is the state-of-art technology for neutrino detection thanks to its superb 3D tracking and calorimetry performance. Its main feature is the charge amplification in gas argon which provides excellent signal-to-noise ratio. Electrons produced in the liquid argon are extracted in the gas phase. Here, a readout plane based on Large Electron Multiplier detectors provides amplification of the charges before its collection onto an anode with strip readout. The charge amplification enables constructing fully homoge- nous giant LAr-TPCs with tuneable gain, excellent charge imaging performance and increased sensitivity to low energy events. Following a staged approach the WA105 collaboration is con- structing a dual phase LAr-TPC with an active volume of 3x1x1m3 that will soon be tested with cosmic rays. Its construction and operation aims to test scalable solutions for the crucial aspects of this technology: ultra high argon purity in non-evacuable tank, la...

  5. Probing the electronic structures of low oxidation-state uranium fluoride molecules UFx- (x = 2-4)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei-Li [Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA; Hu, Han-Shi [Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China; William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Jian, Tian [Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA; Lopez, Gary V. [Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA; Su, Jing [Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China; Li, Jun [Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China; William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Wang, Lai-Sheng [Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA

    2013-12-28

    We report the experimental observation of gaseous UFx- (x = 2-4) anions, which are investigated using photoelectron spectroscopy and relativistic quantum chemistry. Vibrationally resolved photoelectron spectra are obtained for all three species and the electron affinities of UFx (x = 2-4) are measured to be 1.16(3), 1.09(3), and 1.58(3) eV, respectively. Significant multi-electron transitions are observed in the photoelectron spectra of U(5f37s2)F2-, as a result of strong electron correlation effects of the two 7s electrons. The U-F symmetric stretching vibrational modes are resolved for the ground states of all UFx (x = 2-4) neutrals. Theoretical calculations are performed to qualitatively understand the photoelectron spectra. The entire UFx- and UFx (x = 1-6) series are considered theoretically to examine the trends of U-F bonding and the electron affinities as a function of fluorine coordination. The increased U-F bond lengths and decreased bond orders from UF2- to UF4- indicate that the U-F bonding becomes weaker as the oxidation state of U increases from I to III.

  6. High resolution measurements of Cyg X-1 from rockets

    International Nuclear Information System (INIS)

    Rothschild, R.E.; Boldt, E.A.; Holt, S.S.; Serlemitsos, P.J.

    1976-01-01

    Cyg X-1 was observed on two occasions (Oct. 4, 1973 and Oct. 3, 1974) by the Goddard x-ray rocket payload. This payload consisted of two gas proportional counters (xenon--methane with 710 cm 2 and argon--methane with 610 cm 2 ) using the same 128 channel pulse height analyzer and having 320 μs temporal resolution on the 1973 flight and 160 μs resolution on the 1974 flight. During both flights bursts of 1 ms duration were observed with very high statistical certainty. To date all 13 of these bursts have been analyzed for spectral and temporal character, and the results of this analysis are presented. The spectra of overall x-ray emission from both flights are also presented. In a source known for its variability it is remarkable that the spectra taken one year apart are virtually identical

  7. The Extreme Spin of the Black Hole Cygnus X-1

    Science.gov (United States)

    Gou, Lijun; McClintock, Jeffrey E.; Reid, Mark J.; Orosz, Jerome A.; Steiner, James F.; Narayan, Ramesh; Xiang, Jingen; Remillard, Ronald A.; Arnaud, Keith A.; Davis, Shane W.

    2011-01-01

    Remarkably, an astronomical black hole is completely described by the two numbers that specify its mass and its spin. Knowledge of spin is crucial for understanding how, for example, black holes produce relativistic jets. Recently, it has become possible to measure the spins of black holes by focusing on the very inner region of an accreting disk of hot gas orbiting the black hole. According to General Relativity (GR), this disk is truncated at an inner radius 1 that depends only on the mass and spin of the black hole. We measure the radius of the inner edge of this disk by fitting its continuum X-ray spectrum to a fully relativistic model. Using our measurement of this radius, we deduce that the spin of Cygnus X-1 exceeds 97% of the maximum value allowed by GR.

  8. Measuring a Truncated Disk in Aquila X-1

    Science.gov (United States)

    King, Ashley L.; Tomsick, John A.; Miller, Jon M.; Chenevez, Jerome; Barret, Didier; Boggs, Steven E.; Chakrabarty, Deepto; Christensen, Finn E.; Craig, William W.; Feurst, Felix; hide

    2016-01-01

    We present NuSTAR and Swift observations of the neutron star Aquila X-1 during the peak of its 2014 July outburst. The spectrum is soft with strong evidence for a broad Fe K(alpha) line. Modeled with a relativistically broadened reflection model, we find that the inner disk is truncated with an inner radius of 15 +/- 3RG. The disk is likely truncated by either the boundary layer and/or a magnetic field. Associating the truncated inner disk with pressure from a magnetic field gives an upper limit of B < 5+/- 2x10(exp 8) G. Although the radius is truncated far from the stellar surface, material is still reaching the neutron star surface as evidenced by the X-ray burst present in the NuSTAR observation.

  9. Pion production In The Inner Disk Around Cygnus X-1

    International Nuclear Information System (INIS)

    Meirelles Filho, C.; Miyake, H.; Timoteo, V.S.; Lima, C.L.

    2004-01-01

    Neutron production via 4He breakup and p(p, nπ+)p is considered in the innermost region of an accretion disk surrounding a Kerr Black Hole. Close to the horizon, the contribution from p(p, nπ+)p to the neutron production is comparable to that from the breakup. It is shown that the viscosity generated by the collisions of the accreting matter with the neutrons may drive stationary accretion, for accretion rates below a critical value. In this case, solution to the disk equations is double-valued and for both solutions protons overnumber the pairs. We suggest that these solutions may mimic the states of high and low luminosity observed in Cygnus X-1

  10. Ultra-high energy signals from Hercules X-1

    International Nuclear Information System (INIS)

    Haines, T.J.; Alexandreas, D.E.; Allen, R.C.

    1988-01-01

    The expectation that high-energy neutrinos are emitted from astrophysical objects depends strongly on the observation of those objects in gamma-rays, especially at TeV and PeV energies. A search for bursts of gamma-ray events from Hercules X-1 at energies above 50 TeV yielded two significant bursts, both occurring on UT 24 July 1986. The events were pulsed with a period of 1.23568 s, significantly different from estimates of the pulsar period at that time. The probability that the signal is a random background fluctuation is about 2 /times/ 10/sup /minus/5/, not including the fact that there were two other independent observations of the source at nearly the same time. The muon content of the burst events is anomalous when compared with expectations of gamma-ray showers, perhaps signalling the onset of new physics at these energies. 9 refs., 4 figs., 1 tab

  11. 10 microsecond time resolution studies of Cygnus X-1

    Energy Technology Data Exchange (ETDEWEB)

    Wen, H. C. [Stanford Univ., CA (United States)

    1997-06-01

    Time variability analyses have been applied to data composed of event times of X-rays emitted from the binary system Cygnus X-1 to search for unique black hole signatures. The X-ray data analyzed was collected at ten microsecond time resolution or better from two instruments, the High Energy Astrophysical Observatory (HEAO) A-1 detector and the Rossi X-ray Timing Explorer (XTE) Proportional Counter Array (PCA). HEAO A-1 and RXTE/PCA collected data from 1977--79 and from 1996 on with energy sensitivity from 1--25 keV and 2--60 keV, respectively. Variability characteristics predicted by various models of an accretion disk around a black hole have been searched for in the data. Drop-offs or quasi-periodic oscillations (QPOs) in the Fourier power spectra are expected from some of these models. The Fourier spectral technique was applied to the HEAO A-1 and RXTE/PCA data with careful consideration given for correcting the Poisson noise floor for instrumental effects. Evidence for a drop-off may be interpreted from the faster fall off in variability at frequencies greater than the observed breaks. Both breaks occur within the range of Keplerian frequencies associated with the inner edge radii of advection-dominated accretion disks predicted for Cyg X-1. The break between 10--20 Hz is also near the sharp rollover predicted by Nowak and Wagoner`s model of accretion disk turbulence. No QPOs were observed in the data for quality factors Q > 9 with a 95% confidence level upper limit for the fractional rms amplitude at 1.2% for a 16 M⊙ black hole.

  12. SUPERORBITAL PHASE-RESOLVED ANALYSIS OF SMC X-1

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chin-Ping; Chou, Yi; Yang, Ting-Chang; Su, Yi-Hao, E-mail: m929011@astro.ncu.edu.tw, E-mail: yichou@astro.ncu.edu.tw [Graduate Institute of Astronomy, National Central University, Jhongli 32001, Taiwan (China)

    2013-08-10

    The high-mass X-ray binary SMC X-1 is an eclipsing binary with an orbital period of 3.89 days. This system exhibits a superorbital modulation with a period varying between {approx}40 days and {approx}65 days. The instantaneous frequency and the corresponding phase of the superorbital modulation can be obtained by a recently developed time-frequency analysis technique, the Hilbert-Huang transform (HHT). We present a phase-resolved analysis of both the spectra and the orbital profiles with the superorbital phase derived from the HHT. The X-ray spectra observed by the Proportional Counter Array on board the Rossi X-ray Timing Explorer are fitted well by a blackbody plus a Comptonized component. The plasma optical depth, which is a good indicator of the distribution of material along the line of sight, is significantly anti-correlated with the flux detected at 2.5-25 keV. However, the relationship between the plasma optical depth and the equivalent width of the iron line is not monotonic. There is no significant correlation for fluxes higher than {approx}35 mCrab but clear positive correlation when the intensity is lower than {approx}20 mCrab. This indicates that the iron line production is dominated by different regions of this binary system in different superorbital phases. To study the dependence of the orbital profile on the superorbital phase, we obtained the eclipse profiles by folding the All Sky Monitor light curve with the orbital period for different superorbital states. A dip feature, similar to the pre-eclipse dip in Her X-1, lying at orbital phase {approx}0.6-0.85, was discovered during the superorbital transition state. This indicates that the accretion disk has a bulge that absorbs considerable X-ray emission in the stream-disk interaction region. The dip width is anti-correlated with the flux, and this relation can be interpreted by the precessing tilted accretion disk scenario.

  13. Synchrotron and Coulomb Boiler in Cygnus X-1

    International Nuclear Information System (INIS)

    Malzac, Julien; Belmont, Renaud

    2009-01-01

    We use a new code to simulate the radiation and kinetic processes in the X-ray emitting region around accreting black holes and constrain the magnetic field and temperature of the hot protons in the corona of Cygnus X-1. In the hard state we find a magnetic field below equipartition with radiation, suggesting that the corona is not powered through magnetic field dissipation (as assumed in most accretion disc corona models). On the other hand, our results also point toward proton temperatures that are substantially lower than typical temperatures of the ADAF models. Finally, we show that in both spectral states Comptonising plasma could be powered essentially through power-law acceleration of non-thermal electrons, which are then partly thermalised by the synchrotron and Coulomb boiler. This suggests that, contrary to current beliefs, the corona of the HSS and that of the LHS could be of very similar nature. The differences between the LHS and HSS coronal spectra would then be predominantly caused by the strong disc soft cooling emission which is present in the HSS and absent in the LHS.

  14. Optical photometry of Cygnus X-1: 1972-1976

    International Nuclear Information System (INIS)

    Walker, E.N.; Quintanilla, A.R.

    1978-01-01

    The blue (Johnson B) magnitude of HDE 226868, the optical counterpart of Cygnus X-1, has been measured on 349 nights between 1972 April and 1976 December. The best-fit period to these data is 5.6015 +- 0.0006 days and the light-curve obtained by folding these data with this period shows features with duration < 0.1 P in addition to the well-established double maxima and minima. It is found that the mean brightness of the star changes by 0.02 mag on a timescale of approximately 150 day and that the extremes of this brightness range are associated with two forms of the light-curve which in combination yield much of the detailed structure of the five-year mean curve. The observations show that there was no change much greater than 0.001 mag in either the 5.6 or 150-day light-curves associated with the X-ray high states. However, a unique form of the 5.6-day light-curve did occur just at the start of the 1975 November X-ray high state. There is some evidence for an overall brightness change during the five years of approximately 0.01 mag. (author)

  15. Short-term variability of Cyg X-1

    International Nuclear Information System (INIS)

    Oda, M.; Doi, K.; Ogawara, Y.

    1976-01-01

    The short-term X-ray variability distinguishes Cyg X-1, which is the most likely candidate for a black hole, from other X-ray sources. The present status of our knowledge on this short-term variation, mainly from the UHURU, the MIT and the GSFC observations, is reviewed. The nature of impulsive variations which compose the time variation exceeding the statistical fluctuation is discussed. There are indications that the energy spectrum of large pulses is harder than the average spectrum, or that the large pulses are the characteristics of the hard component of the spectrum if it is composed of two, soft and hard, components. Features of the variations may be partly simulated by the superposition of random shot-noise pulses with a fraction of a second duration. However, the autocorrelation analysis and the dynamic spectrum analysis indicate that the correlation lasts for several seconds and in the variation are buried some regularities which exhibit power concentrations in several frequency bands; 0.2-0.3, 0.4-0.5, 0.8, 1.2-1.5 Hz. There are several possible interpretations of these results in terms of; e.g. (a) a mixture of shot-noise pulses with two or more constant durations, (b) the shape of the basic shot-noise pulse, (c) bunching of the pulses, (d) superposition of wave-packets or temporal oscillations. But we have not yet reached any definite understandings in the nature of the variabilities. The substructure of the fluctuations on a time scale of milliseconds suggested by two investigations is also discussed. (Auth.)

  16. Short-term variability of CYG X-1

    International Nuclear Information System (INIS)

    Oda, M.; Doi, K.; Ogawara, Y.; Takagishi, K.; Wada, M.

    1975-01-01

    The short-term X-ray variability distinguishes Cyg X-1, which is the most likely candidate of the black hole, from other X-ray sources. Present status of our knowledge on this short-term variation mainly from the Uhuru, the MIT and the GSFC observations is reviewed. The nature of impulsive variations which compose the time variation exceeding the statistical fluctuation is discussed. There are indications that the energy spectrum of large pulses is harder than the average spectrum or the large pulses are the characteristics of the hard component of the spectrum if it is composed of two, soft and hard, components. Features of the variations may be partly simulated by the superposition of random short-noise pulses with a fraction of a second duration. However, the autocorrelation analysis and the dynamic spectrum analysis indicate that the correlation lasts for several seconds and in the variation buried are some regularities which exhibit power concentrations in several frequency bands; 0.2 -- 0.3, 0.4 -- 0.5, 0.8, 1.2 -- 1.5 Hz. There are several possible interpretation of these results in terms of: e.g. a) a mixture of short-noise pulses with two or more constant durations, b) the shape of the basic shot-noise pulse, c) bunching of the pulses, d) superposition of wave-packets or temporal oscillations. But we have not yet reached any definite understandings in the nature of the variabilities. The sub-structure of the fluctuations on a time scale of milli-second suggested by two investigations is also discussed. (auth.)

  17. High-energy gamma-rays from Cyg X-1

    Science.gov (United States)

    Zdziarski, Andrzej A.; Malyshev, Denys; Chernyakova, Maria; Pooley, Guy G.

    2017-11-01

    We have obtained a firm detection of Cyg X-1 during its hard and intermediate spectral states in the energy range of 40 MeV-60 GeV based on observations by the Fermi Large Area Telescope, confirming the independent results at ≥60 MeV of a previous work. The detection significance is ≃8σ in the 0.1-10 GeV range. In the soft state, we have found only upper limits on the emission at energies ≳0.1 MeV. However, we have found emission with a very soft spectrum in the 40-80 MeV range, not detected previously. This is likely to represent the high-energy cut-off of the high-energy power-law tail observed in the soft state. Similarly, we have detected a γ-ray soft excess in the hard state, which appears to be of similar origin. We have also confirmed the presence of an orbital modulation of the detected emission in the hard state, expected if the γ-rays are from Compton upscattering of stellar blackbody photons. However, the observed modulation is significantly weaker than that predicted if the blackbody upscattering were the dominant source of γ-rays. This argues for a significant contribution from γ-rays produced by the synchrotron self-Compton process. We have found that such strong contribution is possible if the jet is strongly clumped. We reproduce the observed hard-state average broad-band spectrum using a self-consistent jet model, taking into account all the relevant emission processes, e± pair absorption and clumping. This model also reproduces the amplitude of the observed orbital modulation.

  18. Electronic structure of ZrX2 (X = Se, Te)

    Science.gov (United States)

    Shkvarin, A. S.; Merentsov, A. I.; Shkvarina, E. G.; Yarmoshenko, Yu. M.; Píš, I.; Nappini, S.; Titov, A. N.

    2018-03-01

    The electronic structure of the ZrX2 (X = Se, Te) compounds has been studied using photoelectron, resonant photoelectron and X-ray absorption spectroscopy, theoretical calculations of the X-ray absorption spectra, and density of electronic states. It was found that the absorption spectra and valence band spectra are influenced by the chalcogen type. The results of the multiplet calculation of the Zr4+ atom show that the change in the splitting in the crystal field, which is described by the 10Dq parameter, is due to the change in the ratio of covalent and ionic contributions to the chemical bond. The resonance band near the Fermi level in the valence band spectra is observed for ZrTe2 in the Zr 3p-4d resonant excitation mode. The extent of photon energy indicates the charge localization on the Zr atom. Similar resonance band for ZrSe2 is absent; it indicates the presence of a gap at the Fermi level.

  19. μSR Study of the Unusual Magnetic Ordering in the Frustrated Antiferromagnet Zn(CrxGa1-x)2O4

    International Nuclear Information System (INIS)

    Kikuchi, H.; Fukushima, H.; Higemoto, W.; Nishiyama, K.

    2001-01-01

    μSR spectra on the spin frustrating spinel antiferromagnet Zn(Cr x Ga 1-x ) 2 O 4 (x=0.9,1.0) have been measured. For x=1.0 compound, both the relaxation rate and the initial asymmetry showed distinct anomalies at the Neel temperature. The magnetic susceptibility for the x=0.9 compound was known to have a faint peak at around 12 K, whose origin was not clear so far. Our μSR study revealed that this temperature is the onset temperature of development of the magnetic correlation accompanied by appreciable spin fluctuations.

  20. The Return of the Bursts : Thermonuclear Flashes from Circinus X-1

    NARCIS (Netherlands)

    Linares, M.; Watts, A.; Altamirano, D.; Soleri, P.; Degenaar, N.; Yang, Y.; Wijnands, R.; Casella, P.; Homan, J.; Chakrabarty, D.; Rea, N.; Armas-Padilla, M.; Cavecchi, Y.; Kalamkar, M.; Kaur, R.; Patruno, A.; van der Klis, M.

    We report the detection of 15 X-ray bursts with RXTE and Swift observations of the peculiar X-ray binary Circinus X-1 (Cir X-1) during its 2010 May X-ray re-brightening. These are the first X-ray bursts observed from the source after the initial discovery by Tennant and collaborators, 25 years ago.

  1. X-ray diffraction investigation of the sulphur induced 4x1 reconstruction of Ni(110)

    DEFF Research Database (Denmark)

    Foss, M.; Feidenhans'l, R.; Nielsen, M.

    1993-01-01

    The atomic structure of the Ni(110)4 x 1-S reconstruction has been determined on the basis of surface X-ray diffraction measurements. An analysis of the in-plane diffraction data shows that the model consists of Ni rows along the [001] direction, two for every 4 x 1 unit cell, corresponding to 0....

  2. Role of the dimensionality of the [GaX]2 network in the Zintl phases EuGa2X2

    KAUST Repository

    Singh, Nirpendra; Pöttgen, Rainer; Schwingenschlö gl, Udo

    2012-01-01

    The structural, electronic, magnetic, optical, and thermoelectric properties of EuGa2X2 (X = P, As, and Sb) are investigated using first principles calculations (taking into account the onsite Coulomb interaction) and the semi

  3. Bacillus pumilus KatX2 confers enhanced hydrogen peroxide resistance to a Bacillus subtilis PkatA::katX2 mutant strain.

    Science.gov (United States)

    Handtke, Stefan; Albrecht, Dirk; Zühlke, Daniela; Otto, Andreas; Becher, Dörte; Schweder, Thomas; Riedel, Kathrin; Hecker, Michael; Voigt, Birgit

    2017-04-26

    Bacillus pumilus cells exhibit a significantly higher resistance to hydrogen peroxide compared to closely related Bacilli like Bacillus subtilis. In this study we analyzed features of the catalase KatX2 of B. pumilus as one of the most important parts of the cellular response to hydrogen peroxide. KatX2, the vegetative catalase expressed in B. pumilus, was compared to the vegetative catalase KatA of B. subtilis. Data of our study demonstrate that B. pumilus can degrade toxic concentrations of hydrogen peroxide faster than B. subtilis. By replacing B. subtilis katA gene by katX2 we could significantly enhance its resistance to H 2 O 2 and its potential to eliminate this toxic compound. Mutant cells showed a 1.5- to 2-fold higher survival to toxic concentrations of hydrogen peroxide compared to wild type cells. Furthermore, we found reversible but also irreversible oxidations of the KatX2 protein which, in contrast to KatA, contains several cysteine residues. Our study indicates that the catalase KatX2 plays a major role in the increased resistance of B. pumilus to oxidative stress caused by hydrogen peroxide. Resistance to hydrogen peroxide of other Bacilli can be enhanced by exchanging the native catalase in the cells with katX2.

  4. High-pressure syntheses of lanthanide polysulfides and polyselenides LnX_1_._9 (Ln = Gd-Tm, X = S, Se)

    International Nuclear Information System (INIS)

    Mueller, Carola J.; Schwarz, Ulrich; Doert, Thomas

    2012-01-01

    The polysulfides LnS_1_._9 and polyselenides LnSe_1_._9 of the lanthanide metals from gadolinium to thulium were prepared by high-pressure high-temperature synthesis. The compounds adopt the tetragonal CeSe_1_._9 structure type in space group P4_2/n (No. 86) with lattice parameters of 8.531 Aa ≤ a ≤ 8.654 Aa and 15.563 Aa ≤ c ≤ 15.763 Aa for the sulfides and 8.869 Aa ≤ a ≤ 9.076 Aa and 16.367 Aa ≤ c ≤ 16.611 Aa for the selenides. The atomic pattern consists of puckered double slabs [LnX]"+ and planar chalcogenide layers with ten possible chalcogen positions, of which eight are occupied by chalcogen atoms forming dinuclear X_2"2"- dianions, one by a single X"2"- ion and one remaining vacant. This resembles a √5 x √5 x 2 superstructure of the ZrSSi aristotype. Structural relationships to the aristotype and the related lanthanide polychalcogenides LnX_2_-_δ (Ln = La-Tm, X = S-Te, δ = 0 - 0.3) are discussed. The samples synthesized under high-pressure conditions (p > 1 GPa) decompose slowly under release of sulfur or selenium at ambient conditions. The crystal structure of a partially degraded thulium-polysulfide sample can be described as an incommensurate variant of the original TmS_1_._9 motif. Additionally, the isostructural ternary compound Gd(S_1_-_xSe_x)_1_._9 was synthesized and characterized by powder X-ray diffraction. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Long-term studies with the Ariel-5 asm. 1: Her X-1, Vela X-1 and Cen X-3. [periodic variations

    Science.gov (United States)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. J.

    1978-01-01

    Twelve hundred days of 3-6 keV X-ray data from Her X-1, Vela X-1 and Cen X-3 accumulated with the Ariel-5 all-sky monitor are interrogated. The binary periodicities of all three can be clearly observed, as can the approximately 35-d variation of Her X-1, for which we can refine the period to 34.875 plus or minus .030-d. No such longer-term periodicity less than 200-d is observed from Vela X-1. The 26.6-d low-state recurrence period for Cen X-3 previously suggested is not observed, but a 43.0-d candidate periodicity is found which may be consistent with the precession of an accretion disk in that system. The present results are illustrative of the long-term studies which can be performed on approximately 50 sources over a temporal base which will ultimately extend to at least 1800 days.

  6. Atmospheric chemistry of perfluorinated aldehyde hydrates (n-C(x)F(2x+1)CH(OH)2, x = 1, 3, 4)

    DEFF Research Database (Denmark)

    Andersen, Mads Peter Sulbæk; Toft, A.; Nielsen, O.J.

    2006-01-01

    . Bubbling CF(3)CHO/air mixtures through liquid water led to >80% conversion of CF(3)CHO into the hydrate within the approximately 2 s taken for passage through the bubbler. These results suggest that OH radical initiated oxidation of C(x)F(2x+1)CH(OH)(2) hydrates could be a significant source...

  7. Probing the electronic structures of low oxidation-state uranium fluoride molecules UF{sub x}{sup −} (x = 2−4)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei-Li; Jian, Tian; Lopez, Gary V.; Wang, Lai-Sheng, E-mail: lai-sheng-wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States); Hu, Han-Shi; Li, Jun, E-mail: junli@tsinghua.edu.cn [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China); William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Su, Jing [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2013-12-28

    We report the experimental observation of gaseous UF{sub x}{sup −} (x = 2−4) anions, which are investigated using photoelectron spectroscopy and relativistic quantum chemistry. Vibrationally resolved photoelectron spectra are obtained for all three species and the electron affinities of UF{sub x} (x = 2−4) are measured to be 1.16(3), 1.09(3), and 1.58(3) eV, respectively. Significant multi-electron transitions are observed in the photoelectron spectra of U(5f{sup 3}7s{sup 2})F{sub 2}{sup −}, as a result of strong electron correlation effects of the two 7s electrons. The U−F symmetric stretching vibrational modes are resolved for the ground states of all UF{sub x} (x = 2−4) neutrals. Theoretical calculations are performed to qualitatively understand the photoelectron spectra. The entire UF{sub x}{sup −} and UF{sub x} (x = 1−6) series are considered theoretically to examine the trends of U−F bonding and the electron affinities as a function of fluorine coordination. The increased U−F bond lengths and decreased bond orders from UF{sub 2}{sup −} to UF{sub 4}{sup −} indicate that the U−F bonding becomes weaker as the oxidation state of U increases from I to III.

  8. LEED-IV study of the rutile TiO2(110)-1x2 surface with a Ti-interstitial added-row reconstruction

    International Nuclear Information System (INIS)

    Blanco-Rey, M.; Mendez, J.; Lopez, M. F.; Roman, E.; Martin-Gago, J. A.; Andres, P. L. de; Abad, J.; Rogero, C.

    2007-01-01

    Upon sputtering and annealing in UHV at ∼1000 K, the rutile TiO 2 (110) surface undergoes a 1x1→1x2 phase transition. The resulting 1x2 surface is Ti rich, formed by strands of double Ti rows as seen on scanning tunneling microscopic images, but its detailed structure and composition have been subject to debate in the literature for years. Recently, Park et al. [Phys. Rev. Lett. 96, 226105 (2006)] have proposed a model where Ti atoms are located on interstitial sites with Ti 2 O stoichiometry. This model, when it is analyzed using LEED-IV data [Phys. Rev. Lett. 96, 0055502 (2006)], does not yield an agreement between theory and experiment as good as the previous best fit for Onishi and Iwasawa's model for the long-range 1x2 reconstruction. Therefore, the Ti 2 O 3 added row is the preferred one from the point of view low-energy electron diffraction

  9. Evidence for an approx.300 day period in Cygnus X-1

    International Nuclear Information System (INIS)

    Priedhorsky, W.C.; Terrell, J.; Holt, S.S.

    1983-01-01

    We present the time history of X-ray emission from Cyg X-1 over an 11 year period, with 10 day resolution. The data were obtained by experiments on the Vela 5B (1969--1979) and Ariel 5 (1974--1980) satellites. Cyg X-1 varies by approx.25% with a 294 +- 4 day period. This modulation is apparently unrelated to the known transitions between the source high and low states. Flux minima occur at 1974.05+nP. The observed period is within the possible range for the precession period of an accretion disk, or of the companion star HDE 226868, in the Cyg X-1 system

  10. Timing and Spectral Studies of the Peculiar X-ray Binary Circinus X-1

    Energy Technology Data Exchange (ETDEWEB)

    Saz Parkinson, Pablo M.

    2003-08-26

    Circinus X-1 (Cir X-1) is an X-ray binary displaying an array of phenomena which makes it unique in our Galaxy. Despite several decades of observation, controversy surrounds even the most basic facts about this system. It is generally classified as a Neutron Star (NS) Low Mass X-ray Binary (LMXB),though this classification is based primarily on the observation of Type I X-ray Bursts by EXOSAT in 1985. It is believed to be in a very eccentric {approx} 16.5 day orbit, displaying periodic outbursts in the radio and other frequency bands (including optical and IR) which reinforce the notion that this is in fact the orbital period. Cir X-1 lies in the plane of the Galaxy, where optical identification of the companion is made difficult due to dust obscuration. The companion is thought to be a low mass star, though a high mass companion has not currently been ruled out. In this work, the author analyzes recent observations of Cir X-1 made with the Unconventional Stellar Aspect (USA) experiment, as well as archival observations of Cir X-1 made by a variety of instruments, from as early as 1969. The fast (< 1 s) timing properties of Cir X-1 are studied by performing FFT analyses of the USA data. Quasi-Periodic Oscillations (QPOs) in the 1-50 Hz range are found and discussed in the context of recent correlations which question the leading models invoked for their generation. The energy dependence of the QPOs (rms increasing with energy) argues against them being generated in the disk and favors models in which the QPOs are related to a higher energy Comptonizing component. The power spectrum of Cir X-1 in its soft state is compared to that of Cygnus X-1 (Cyg X-1), the prototypical black hole candidate. Using scaling arguments the author argues that the mass of Cir X-1 could exceed significantly the canonical 1.4 M{circle_dot} mass of a neutron star, possibly partly explaining why this object appears so different to other neutron stars. The spectral evolution of Cir X-1 is

  11. The growth of Zn on a Si(1 0 0)-2x1 surface

    International Nuclear Information System (INIS)

    Xie Zhaoxiong; Tanaka, Ken-ichi

    2005-01-01

    Adsorption of Zn atoms on a Si(1 0 0)-2x1 surface was studied by scanning tunneling microscopy at room temperature. Narrow lines are grown perpendicular to the Si-dimer rows of the [1 1 0] direction at low coverage. The narrow line is formed by arraying rectangular Zn 3 dots, where a dot is composed of one Zn atom on a Si dimer and the other two in the neighboring two hollow sites. When the Si(1 0 0)-2x1 surface is covered with one monolayer of Zn, a 4x1 structure is established. More deposition of Zn on the 4x1 monolayer grows into three-dimensional Zn islands

  12. 1-deg x 1-deg Terrestrial Mean Free-Air Anomalies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1x1 degree Terrestrial Mean Free-Air Gravity Anomaly and Geoid Undulations Data Base was compiled and developed by the Ohio State University. This data base was...

  13. Hard X-ray observations of the Her X-1 line feature

    International Nuclear Information System (INIS)

    Manchanda, R.K.; Vialetto, G.; Bazzano, A.; La Padula, C.; Polcaro, V.F.; Ubertini, P.

    1982-01-01

    We have carried out two observations separated by a year in 1980 and 1981 during the mid-on phase of Her X-1, by using xenon filled multi-wire proportional chambers. This paper presents the time-averaged spectral results of Her X-1 in the 15-150 keV energy range. The possible case of the line centroid variability seen during 1980 experiment is also discussed. (orig./WL)

  14. Analysis of B chromosome nondisjunction induced by the r-X1 deficiency in maize.

    Science.gov (United States)

    Tseng, Shih-Hsuan; Peng, Shu-Fen; Cheng, Ya-Ming

    2017-11-20

    The maize B chromosome typically undergoes nondisjunction during the second microspore division. For normal A chromosomes, the r-X1 deficiency in maize can induce nondisjunction during the second megaspore and first microspore divisions. However, it is not known whether the r-X1 deficiency also induces nondisjunction of the maize B chromosome during these cell divisions. To answer this question, chromosome numbers were determined in the progeny of r-X1/R-r female parents carrying two B chromosomes. Some of the r-X1-lacking progeny (21.2%) contained zero or two B chromosomes. However, a much higher percentage of the r-X1-containing progeny (43.4%) exhibited zero or two B chromosomes, but none displayed more than two B chromosomes. Thus, the results indicated that the r-X1 deficiency could also induce nondisjunction of the B chromosome during the second megaspore division; moreover, the B chromosome in itself could undergo nondisjunction during the same division. In addition, pollen grains from plants with two B chromosomes lacking or exhibiting the r-X1 deficiency were compared via pollen fluorescence in situ hybridization (FISH) using a B chromosome-specific probe. The results revealed that the r-X1 deficiency could induce the occurrence of B chromosome nondisjunction during the first microspore division and that the B chromosome in itself could undergo nondisjunction during the same division at a lower frequency. Our data shed more light on the behavior of the maize B chromosome during cell division.

  15. Silica-supported tungsten carbynes (≡SiO)xW(≡CH)(Me)y (x = 1, y = 2; X = 2, y = 1): New efficient catalysts for alkyne cyclotrimerization

    KAUST Repository

    Riache, Nassima; Dé ry, Alexandre; Callens, Emmanuel; Poater, Albert; Samantaray, Manoja; Dey, Raju; Hong, Jinhua; Li, Kun; Cavallo, Luigi; Basset, Jean-Marie

    2015-01-01

    demonstrate that this catalyst species is active for alkyne cyclotrimerization without the formation of significant alkyne metathesis products. Additional DFT calculations highlight the importance of the W coordination sphere in supporting this experimental

  16. Resolution and evolution of the duck-billed platypus karyotype with an X1Y1X2Y2X3Y3X4Y4X5Y5 male sex chromosome constitution.

    Science.gov (United States)

    Rens, Willem; Grützner, Frank; O'brien, Patricia C M; Fairclough, Helen; Graves, Jennifer A M; Ferguson-Smith, Malcolm A

    2004-11-16

    The platypus (2n = 52) has a complex karyotype that has been controversial over the last three decades. The presence of unpaired chromosomes and an unknown sex-determining system especially has defied attempts at conventional analysis. This article reports on the preparation of chromosome-specific probes from flow-sorted chromosomes and their application in the identification and classification of all platypus chromosomes. This work reveals that the male karyotype has 21 pairs of chromosomes and 10 unpaired chromosomes (E1-E10), which are linked by short regions of homology to form a multivalent chain in meiosis. The female karyotype differs in that five of these unpaired elements (E1, E3, E5, E7, and E9) are each present in duplicate, whereas the remaining five unpaired elements (E2, E4, E6, E8, and E10) are absent. This finding indicates that sex is determined by the alternate segregation of the chain of 10 during spermatogenesis so that equal numbers of sperm bear either one of the two groups of five elements, i.e., five X and five Y chromosomes. Chromosome painting reveals that these X and Y chromosomes contain pairing (XY shared) and differential (X- or Y-specific) segments. Y differential regions must contain male-determining genes, and X differential regions should be dosage-compensated in the female. Two models for the evolution of the sex-determining system are presented. The resolution of the longstanding debate over the platypus karyotype is an important step toward the understanding of mechanisms of sex determination, dosage compensation, and karyotype evolution.

  17. Thermodynamic study of binary mixture of x1[C6mim][BF4] + x21-propanol: Measurements and molecular modeling

    International Nuclear Information System (INIS)

    Kermanpour, F.; Sharifi, T.

    2012-01-01

    Highlights: ► Densities and viscosities for binary mixture of {x 1 [C 6 mim][BF 4 ] + x 2 1-propanol} were measured at different temperatures. ► The excess molar functions were calculated from the obtained experimental data. ► These data were correlated with the Redlich–Kister equation and PFP model to obtain the coefficients and standard deviations. - Abstract: Densities, ρ, and viscosities, η, of pure 1-hexyl-3-methylimidazoliumtetrafluoro borate ([C 6 mim][BF 4 ]) and 1-propanol, and their binary mixture {x 1 [C 6 mim][BF 4 ] + x 2 1-propanol} were measured at atmospheric pressure and in the temperature range of 293.15–333.15 K. The excess molar volumes, V m E , thermal expansion coefficients, α, and their excess values, α E , isothermal coefficient of excess molar enthalpy, (∂H m E /∂p) T,x and excess viscosities, η E , were calculated from the experimental values of densities and viscosities. The excess molar volumes of the binary mixture are negative over the entire mole fraction range and increase with increasing temperature. Excess viscosities are negative over the entire mole fraction range of the mixture and decrease with increasing temperature. The obtained excess molar volumes and excess viscosities were correlated with the Redlich–Kister equation. The experimental results have also been used to examine the applicability of Prigogine–Flory–Patterson (PFP) theory in predicting the excess molar volume of the binary mixture. It is indicated that agreement between excess molar volumes calculated via PFP theory and the experimental results is good in all temperatures.

  18. The Effect of Cooperative Learning Model and Kolb Learning Styles on Learning Result of the Basics of Politics

    Science.gov (United States)

    Sugiharto

    2015-01-01

    The aims of this research were to determine the effect of cooperative learning model and learning styles on learning result. This quasi-experimental study employed a 2x2 treatment by level, involved independent variables, i.e. cooperative learning model and learning styles, and learning result as the dependent variable. Findings signify that: (1)…

  19. Observation of short period fluctuation of CygX-1 with balloon

    International Nuclear Information System (INIS)

    Nakagawa, Michio; Sakurai, Takahisa; Uchida, Masayoshi

    1977-01-01

    CygX-1 presents very complex short period fluctuation of X-ray, therefore the hard X-ray was especially observed in 1972 and 1973 with large balloons, and the data were analyzed. This short period fluctuation and energy spectra of CygX-1 in the normal and flare time bands were compared. The observing apparatuses consisted of the 3 in diameter NaI detector and a high pressure proportional counter. The observing method is to turn the gondora alternately to the directions of source (ON) and background (OFF). As for the data analysis, the events at ON and OFF in the observation data in 1972 and 1973 were plotted for time interval. The background component is in agreement with Poisson's distribution, but source component is not. This difference for Poisson's distribution means the behavior of CygX-1. The power spectrum was analyzed, and the strong power density was observed at 5.4 x 10 -2 Hz in ON, but such power density was not observed in OFF. Accordingly this is presumed to be caused by CygX-1. The events for time interval in flare time are shown. The rise of about 2.9 σ exists at 80 msec. The count rates were compared for photon energy in the normal and flare times. The short period fluctuation of hard X-ray from CygX-1 deviates from Poisson's distribution and is different in the normal and flare times. (Nakai, Y.)

  20. Effect of the La/Mg ratio on the structure and electrochemical properties of La xMg 3- xNi 9 ( x=1.6-2.2) hydrogen storage electrode alloys for nickel-metal hydride batteries

    Science.gov (United States)

    Liao, B.; Lei, Y. Q.; Chen, L. X.; Lu, G. L.; Pan, H. G.; Wang, Q. D.

    Effect of La/Mg ratio on the structure and electrochemical properties of La xMg 3- xNi 9 ( x=1.6-2.2) ternary alloys was investigated. All alloys are consisted of a main phase with hexagonal PuNi 3-type structure and a few impurity phases (mainly LaNi 5 and MgNi 2). The increase of La/Mg ratio in the alloys leads to an increase in both the cell volume and the hydride stability. The discharge capacity of the alloys at 100 mA/g increases with the increase of La/Mg ratio and passes though a maximum of 397.5 mAh/g at x=2.0. As the La/Mg ratio increases, the high-rate dischargeability of the alloy electrodes at 1200 mA/g HRD 1200 decreases from 66.7% ( x=1.6) to 26.5% ( x=2.2). The slower decrease of HRD 1200 (from 66.7 to 52.7%) of the alloys with x=1.6-2.0 is mainly attributed to the decrease of electrocatalytic activity of the alloys for charge-transfer reaction, the more rapid decrease of HRD 1200 of the alloys with x>2.0 is mainly attributed to the lowering of the hydrogen diffusion rate in the bulk of alloy. The cycling capacity degradation of the alloys is rather fast for practical application due to the corrosion of La and Mg and the large VH in the hydride phase.

  1. Getting high utilization of peak GFLOPS in real applications in the Cray X1

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, J.M. [Cray Research, Inc., Los Alamos, NM (United States)

    2003-07-01

    This paper will show the advanced characteristics of the Cray X1 and discuss how they are used to achieve high-utilized GFLOPS on many real world applications. On most MPP systems, other than the Earth Simulator and the Cray Inc. X1, advanced scientific applications do not obtain a high percentage of peak performance, in some cases less than 2%. When this small percentage of peak is attained on the processor, one needs to have more individual processors to achieve a TFLOP of sustained performance. Larger numbers of processors result in a tremendous burden on the interconnect. Here again MPPs other than the Earth Simulator and the X1 do not have the interconnect to support the increased number of processors. Combining low processor performance with insufficient scaling results in less than desired performance for many applications. (author)

  2. Systems analysis and engineering of the X-1 Advanced Radiation Source

    International Nuclear Information System (INIS)

    Rochau, G.E.; Hands, J.A.; Raglin, P.S.; Ramirez, J.J.

    1998-01-01

    The X-1 Advanced Radiation Source, which will produce ∼ 16 MJ in x-rays, represents the next step in providing US Department of Energy's Stockpile Stewardship program with the high-energy, large volume, laboratory x-ray sources needed for the Radiation Effects Science and Simulation (RES), Inertial Confinement Fusion (ICF), and Weapon Physics (WP) Programs. Advances in fast pulsed power technology and in z-pinch hohlraums on Sandia National Laboratories' Z Accelerator in 1997 provide sufficient basis for pursuing the development of X-1. This paper will introduce the X-1 Advanced Radiation Source Facility Project, describe the systems analysis and engineering approach being used, and identify critical technology areas being researched

  3. Getting high utilization of peak GFLOPS in real applications in the Cray X1

    International Nuclear Information System (INIS)

    Levesque, J.M.

    2003-01-01

    This paper will show the advanced characteristics of the Cray X1 and discuss how they are used to achieve high-utilized GFLOPS on many real world applications. On most MPP systems, other than the Earth Simulator and the Cray Inc. X1, advanced scientific applications do not obtain a high percentage of peak performance, in some cases less than 2%. When this small percentage of peak is attained on the processor, one needs to have more individual processors to achieve a TFLOP of sustained performance. Larger numbers of processors result in a tremendous burden on the interconnect. Here again MPPs other than the Earth Simulator and the X1 do not have the interconnect to support the increased number of processors. Combining low processor performance with insufficient scaling results in less than desired performance for many applications. (author)

  4. New results from long-term observations of Cyg X-1

    International Nuclear Information System (INIS)

    Holt, S.S.; Boldt, E.A.; Serlemitsos, P.J.; Kaluzienski, L.J.

    1975-08-01

    Observations of Cyg X-1 between October 1974 and July 1975 reveal a persistent 5.6 day modulation of the 3- to 6-keV x-ray intensity, having a minimum in phase with superior conjunction of the HDE 226868 binary system. The modulation is found to be most pronounced just prior to the April--May 1975 increase of Cyg X-1, after which both the modulation and intensity are at their lowest values for the entire duration of the observations. These data imply that the x-ray emission from Cyg X-1 arises from the compact member of HDE 226868, and that the increase of April--May 1975 may have represented the depletion of accreting material which was not mixed into a cylindrically symmetric accretion disk about the compact member

  5. New results from long-term observations of Cygnus X-1

    International Nuclear Information System (INIS)

    Holt, S.S.; Boldt, E.A.; Serlemitsos, P.J.; Kaluzienski, L.J.

    1976-01-01

    Observations of Cyg X-1 between 1974 October and 1975 July reveal a persistent 5/subd/./sub /6 modulation of the 3--6 keV X-ray intensity, having a minimum in phase with superior conjunction of the HDE 226868 binary system. The modulation is found to be most pronounced just prior to the 1975 April--May increase of Cyg X-1, after which both the modulation and intensity are at their lowest values for the entire duration of the observations. These data imply that the X-ray emission from Cyg X-1 arises from the compact member of HDE 226868, and that the increase of 1975 April--May may have represented the depletion of accreting material which had not yet been mixed into a cylindrically symmetric accretion disk about the compact member

  6. New results from long-term observations of Cyg X-1

    International Nuclear Information System (INIS)

    Holt, S.S.; Boldt, E.A.; Serlemitsos, P.J.; Kaluzienski, L.J.

    1976-01-01

    Observations of Cyg X-1 between October 1974 and July 1975 reveal a persistent 5.6 day modulation of the 3 to 6 keV x-ray intensity, having a minimum in phase with superior conjunction of the HDE 226868 binary system. The modulation is found to be most pronounced just prior to the April to May 1975 increase of Cyg X-1, after which both the modulation and intensity are at their lowest values for the entire duration of the observations. These data imply that the x-ray emission from Cyg X-1 arises from the compact member of HDE 226868, and that the increase of April to May 1975 may have represented the depletion of accreting material which had not yet been mixed into a cylindrically symmetric accretion disk about the compact member

  7. Fully reconfigurable 2x2 optical cross-connect using tunable wavelength switching modules

    DEFF Research Database (Denmark)

    Liu, Fenghai; Zheng, Xueyan; Pedersen, Rune Johan Skullerud

    2001-01-01

    A modular tunable wavelength switching module is proposed and used to construct 2x2 fully reconfigurable optical cross-connects. Large size optical switch is avoided in the OXC and it is easy to upgrade to more wavelength channels.......A modular tunable wavelength switching module is proposed and used to construct 2x2 fully reconfigurable optical cross-connects. Large size optical switch is avoided in the OXC and it is easy to upgrade to more wavelength channels....

  8. Purinergic control of inflammation and thrombosis: Role of P2X1 receptors

    Directory of Open Access Journals (Sweden)

    Cécile Oury

    2015-01-01

    Full Text Available Inflammation shifts the hemostatic mechanisms in favor of thrombosis. Upon tissue damage or infection, a sudden increase of extracellular ATP occurs, that might contribute to the crosstalk between inflammation and thrombosis. On platelets, P2X1 receptors act to amplify platelet activation and aggregation induced by other platelet agonists. These receptors critically contribute to thrombus stability in small arteries. Besides platelets, studies by our group indicate that these receptors are expressed by neutrophils. They promote neutrophil chemotaxis, both in vitro and in vivo. In a laser-induced injury mouse model of thrombosis, it appears that neutrophils are required to initiate thrombus formation and coagulation activation on inflamed arteriolar endothelia. In this model, by using P2X1−/− mice, we recently showed that P2X1 receptors, expressed on platelets and neutrophils, play a key role in thrombus growth and fibrin generation. Intriguingly, in a model of endotoxemia, P2X1−/− mice exhibited aggravated oxidative tissue damage, along with exacerbated thrombocytopenia and increased activation of coagulation, which translated into higher susceptibility to septic shock. Thus, besides its ability to recruit neutrophils and platelets on inflamed endothelia, the P2X1 receptor also contributes to limit the activation of circulating neutrophils under systemic inflammatory conditions. Taken together, these data suggest that P2X1 receptors are involved in the interplay between platelets, neutrophils and thrombosis. We propose that activation of these receptors by ATP on neutrophils and platelets represents a new mechanism that regulates thrombo-inflammation.

  9. Gamma rays from Cygnus X-1: Modeling and nonthermal pair production

    International Nuclear Information System (INIS)

    Dermer, C.D.; Liang, E.P.

    1988-02-01

    The gamma-ray bump observed between 0.5 and 2 MeV in the spectrum of Cygnus X-1 can be interpreted as the thermal emissions from a hot (kT/approximately/400 keV) pair-dominated cloud. We argue that the X-rays and gamma rays are produced in separate emission regions, and calculate the photon-photon pair production rate from X-ray and gamma-ray interactions in the vicinity of Cyg X-1 by employing a simplified geometry for the two emitting regions

  10. Recent observations of Hercules X-1 with HEAO-1 and OSO-8

    Science.gov (United States)

    Pravdo, S. H.; Becker, R. H.; Bussard, R. W.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Swank, J. H.; Rothschild, R. E.

    1979-01-01

    HEAO 1 X-ray observations of Her X-1 near an onset of the high state are discussed. An X-ray light curve is determined which indicates that for about 0.5 day before the X-ray intensity turn-on there was 1.2-sec pulsed emission from the source at a level intermediate between the high- and low-state intensities. These results are taken as demonstrating the stability in the 35-day cycle when compared with previous observations. An inconclusive search for 58-keV line emission from Her X-1 is also reported.

  11. Absorption dips at low x-ray energies in Cygnus X-1

    International Nuclear Information System (INIS)

    Murdin, P.

    1976-01-01

    Three more looks with the Copernicus satellite at Cygnus X-1 have produced four more examples of absorption dips, decreases in the 2 to 7 keV flux from Cygnus X-1 with an increase of spectral hardness consistent with photoelectric absorption (Mason et al 1974). The nine now seen, including one by OSO-7 (Li and Clark 1974), are listed in Table 1. Their phase in the spectroscopic binary HD 226868 is also listed, calculated from a newer ephemeris than that in Mason et al (1974), adding the radial velocities by Bolton (1975) and unpublished RGO radial velocities from the 1975 season. (These elements do not differ significantly from Bolton's

  12. Experimental surface charge density of the Si (100)-2x1H surface

    DEFF Research Database (Denmark)

    Ciston, J.; Marks, L.D.; Feidenhans'l, R.

    2006-01-01

    We report a three-dimensional charge density refinement from x-ray diffraction intensities of the Si (100) 2x1H surface. By paying careful attention to parameterizing the bulk Si bonding, we are able to locate the hydrogen atoms at the surface, which could not be done previously. In addition, we...

  13. Occupational Analysis Products: Operations Management- AFSC 3E6X1 (CD-ROM)

    Science.gov (United States)

    computer laser optical disc (CD-ROM); 4 3/4 in.; 23.4 MB. SYSTEMS DETAIL NOTE: ABSTRACT: This is a report of an occupational survey of the Operations ... Management (AFSC 3E6X1, OSSN 2560, Feb 04) career ladder, conducted by the Occupational Analysis Flight, AFOMS. The OSR reports the findings of current

  14. A 1Σ+ → X 1Σ+ bands of the isotopic lithium hydrides

    International Nuclear Information System (INIS)

    Li, K.C.; Stwalley, W.C.

    1977-01-01

    In order to obtain a better understanding of the X 1 Σ + ground state and the A 1 Σ + state potential energy curves of lithium hydride and to examine in detail the concept of ''mass-reduced quantum numbers'' for both an ordinary (X 1 Σ + ) and an anomalous (A 1 Σ + ) electronic state, the emission spectra of the A 1 Σ + → X 1 Σ + bands of the isotopic lithium hydrides and deuterides ere photographed in the 3000 to 5000A region with a 3.4 meter Ebert Spectrograph. The bands found involved v'' = 0 to 7 to various v' = 0 to 17 for 6 LiH, and v'' = 0 to 7 to various v' = 1 to 16 for 6 LiD. Additional bands involving v'' = 4 and 5 were also found for 7 LiH. The vibrational-rotational spectroscopic analysis of 7 LiH, 6 LiH and 6 LiD are reported here, as are the reanalyses of the 7 LiH and 7 LiD data reported by Crawford and Jorgensen. New Rydberg-Klein-Rees (RKR) A 1 Σ + and X 1 Σ + potential curves have been constructed for each individual molecule and are reported, but detailed isotopic comparisons will be reported in subsequent publications

  15. Light Curve Periodic Variability of Cyg X-1 using Jurkevich Method ...

    Indian Academy of Sciences (India)

    Abstract. The Jurkevich method is a useful method to explore periodic- ity in the unevenly sampled observational data. In this work, we adopted the method to the light curve of Cyg X-1 from 1996 to 2012, and found that there is an interesting period of 370 days, which appears in both low/hard and high/soft states.

  16. Light Curve Periodic Variability of Cyg X-1 using Jurkevich Method

    Indian Academy of Sciences (India)

    The Jurkevich method is a useful method to explore periodicity in the unevenly sampled observational data. In this work, we adopted the method to the light curve of Cyg X-1 from 1996 to 2012, and found that there is an interesting period of 370 days, which appears in both low/hard and high/soft states. That period may be ...

  17. Long term variability of Cygnus X-1. V. State definitions with all sky monitors

    NARCIS (Netherlands)

    Grinberg, V.; Hell, N.; Pottschmidt, K.; Böck, M.; Nowak, M.A.; Rodriguez, J.; Bodaghee, A.; Cadolle Bel, M.; Case, G.L.; Hanke, M.; Kühnel, M.; Markoff, S.; Pooley, G.G.; Rothschild, R.E.; Tomsick, J.A.; Wilson-Hodge, C.A.; Wilms, J.

    2013-01-01

    We present a scheme for determining the spectral state of the canonical black hole Cyg X-1 using data from previous and current X-ray all sky monitors (RXTE-ASM, Swift-BAT, MAXI, and Fermi-GBM). Determinations of the hard/intermediate and soft state agree to better than 10% between different

  18. X-2 on ramp with B-50 mothership and support crew

    Science.gov (United States)

    1956-01-01

    Air Force test pilot Capt. Iven Kincheloe stands in front of the Bell X-2 (46-674) on the ramp at Edwards Air Force Base, California. Behind the X-2 are ground support personnel, the B-50 launch aircraft and crew, chase planes, and support vehicles. Kincheloe had flown nearly 100 combat missions in Korea in an F-86 and was credited with shooting down 10 enemy aircraft. He then graduated from the Empire Test Pilot's School in Great Britain in December 1954, whereupon he was assigned to Edwards Air Force Base. He made four powered flights in the X-2. On September 7, 1956, he reached an altitude of 126,200 feet. After the death of Capt. Mel Apt and the loss of the X-2 #1 on September 27, 1956, in the first Mach 3 flight, Kincheloe was assigned as the Air Force project pilot for the X-15. Before he had a chance to fly that rocket-powered aircraft, Kincheloe himself lost his life on July 26, 1958, in an F-104 accident. The X-2 was a swept-wing, rocket-powered aircraft designed to fly faster than Mach 3 (three times the speed of sound). It was built for the U.S. Air Force by the Bell Aircraft Company, Buffalo, New York. The X-2 was flown to investigate the problems of aerodynamic heating as well as stability and control effectiveness at high altitudes and high speeds (in excess of Mach 3). Bell aircraft built two X-2 aircraft. These were constructed of K-monel (a copper and nickel alloy) for the fuselage and stainless steel for the swept wings and control surfaces. The aircraft had ejectable nose capsules instead of ejection seats because the development of ejection seats had not reached maturity at the time the X-2 was conceived. The X-2 ejection canopy was successfully tested using a German V-2 rocket. The X-2 used a skid-type landing gear to make room for more fuel. The airplane was air launched from a modified Boeing B-50 Superfortress Bomber. X-2 Number 1 made its first unpowered glide flight on Aug. 5, 1954, and made a total of 17 (4 glide and 13 powered) flights

  19. P2X1 Receptor Antagonists Inhibit HIV-1 Fusion by Blocking Virus-Coreceptor Interactions.

    Science.gov (United States)

    Giroud, Charline; Marin, Mariana; Hammonds, Jason; Spearman, Paul; Melikyan, Gregory B

    2015-09-01

    HIV-1 Env glycoprotein-mediated fusion is initiated upon sequential binding of Env to CD4 and the coreceptor CXCR4 or CCR5. Whereas these interactions are thought to be necessary and sufficient to promote HIV-1 fusion, other host factors can modulate this process. Previous studies reported potent inhibition of HIV-1 fusion by selective P2X1 receptor antagonists, including NF279, and suggested that these receptors play a role in HIV-1 entry. Here we investigated the mechanism of antiviral activity of NF279 and found that this compound does not inhibit HIV-1 fusion by preventing the activation of P2X1 channels but effectively blocks the binding of the virus to CXCR4 or CCR5. The notion of an off-target effect of NF279 on HIV-1 fusion is supported by the lack of detectable expression of P2X1 receptors in cells used in fusion experiments and by the fact that the addition of ATP or the enzymatic depletion of ATP in culture medium does not modulate viral fusion. Importantly, NF279 fails to inhibit HIV-1 fusion with cell lines and primary macrophages when added at an intermediate stage downstream of Env-CD4-coreceptor engagement. Conversely, in the presence of NF279, HIV-1 fusion is arrested downstream of CD4 binding but prior to coreceptor engagement. NF279 also antagonizes the signaling function of CCR5, CXCR4, and another chemokine receptor, as evidenced by the suppression of calcium responses elicited by specific ligands and by recombinant gp120. Collectively, our results demonstrate that NF279 is a dual HIV-1 coreceptor inhibitor that interferes with the functional engagement of CCR5 and CXCR4 by Env. Inhibition of P2X receptor activity suppresses HIV-1 fusion and replication, suggesting that P2X signaling is involved in HIV-1 entry. However, mechanistic experiments conducted in this study imply that P2X1 receptor is not expressed in target cells or involved in viral fusion. Instead, we found that inhibition of HIV-1 fusion by a specific P2X1 receptor antagonist, NF

  20. The structure and the analytical potential energy function of NH2 (X2B1)

    International Nuclear Information System (INIS)

    Liu Yufang; Jiang Lijuan; Ma Heng; Sun Jinfeng

    2008-01-01

    This paper reports that the equilibrium structure of NH 2 has been optimized at the QCISD/6-311++G (3df, 3pd) level. The ground-state NH 2 has a bent (C 2v , X 2 B 1 ) structure with an angle of 103.0582°. The geometrical structure is in good agreement with the other calculational and experimental results. The harmonic frequencies and the force constants have also been calculated. Based on the group theory and the principle of microscopic reversibility, the dissociation limits of NH 2 (C 2v , X 2 B 1 ) have been derived. The potential energy surface of NH 2 (X 2 B 1 ) is reasonable. The contour lines are constructed, the structure and energy of NH 2 reappear on the potential energy surface

  1. Interaction of GABAA receptors with purinergic P2X2 receptors

    International Nuclear Information System (INIS)

    Shrivastava, A.

    2010-01-01

    GABA A Rs in the spinal cord are evolving as an important target for drug development against pain. Purinergic P2X 2 Rs are also expressed in spinal cord neurons and are known to cross-talk with GABA A Rs. Here we investigated a possible 'dynamic' interaction between GABA A Rs and P2X 2 Rs using co-immunoprecipitation and FRET studies in HEK cells along with co-localization and single particle tracking studies in spinal cord neurons. Our results suggest that a significant proportion of P2X 2 Rs forms a transient complex with GABA A Rs inside the cell, thus stabilizing these receptors and using them for co-trafficking to the cell surface. P2X 2 Rs and GABA A Rs are then co-inserted into the cell membrane and are primarily located extra-synaptically. Furthermore, agonist induced activation of P2X 2 Rs results in disassembly of the receptor complex and destabilization of GABA A Rs whereas P2X 2 Rs are stabilized and form larger clusters. Antagonist-induced blocking of P2XRs results in co-stabilization of this receptor complex at the cell surface. These results suggest a novel mechanism where association of P2XRs with other receptors could be used for specific targeting to the neuronal membrane, thus providing an extrasynaptic receptor reserve that could regulate the excitability of neurons. We further conclude that blocking the excitatory activity of excessively released ATP under diseased state by P2XR antagonists could simultaneously enhance synaptic inhibition mediated by GABA A Rs.(author) (author) [de

  2. Study of Synergetic Effect of X2 and X3 EC Wave in KSTAR

    Directory of Open Access Journals (Sweden)

    Bae Y.S.

    2015-01-01

    Full Text Available An experimental study of the X-mode absorption at the second and the third harmonic frequencies has been performed in KSTAR tokamak. The X2 EC frequency is 110 GHz and the X3 EC frequency is 170 GHz at the nominal KSTAR operating toroidal magnetic field. From the 1-D model of the synergetic effect, the X3 cold resonance should lie at low field side with the X2 cold resonance at the high field side to meet the condition which both X2 and X3 EC waves interact with the same resonant electron at the same radial position. However, 170 GHz X3 cold resonance lies at the high field side with distance of 54 mm from the X2 cold resonance position in KSTAR. This paper presents the study of the synergetic effect of X3 absorption by the X2 ECCD with a scheme of two beam target positions at the same flux surface by scanning the poloidal and toroidal beam injection angles to enhance X3 absorption even in the low temperature plasma in KSTAR. For this study, the3D relativistic ray/tracing and Fokker-Planck codes C3PO/LUKE is used for the quantitative prediction of its synergetic effect. The C3PO/LUKE codes are appropriate for X2 and X3 synergy calculations as the distribution function can be calculated with either one or both waves affecting the absorption rate of each other. This paper also introduces the future ECH system upgrade plan.

  3. The hard X-ray spectrum of Cyg X-1 during the transition in November 1975

    International Nuclear Information System (INIS)

    Sommer, M.; Maurus, H.; Urbach, R.

    1976-01-01

    Some observations are reported of the hard X-ray spectrum of Cyg X-1 during a transition to the high state in November 1975, made with a balloon-borne X-ray detector. The range covered was 25 to 150 keV. The data obtained appeared to confirm the characteristic spectral time variation, and suggested a single power law spectrum from 3 to 80 keV, with an increasing spectral index during the upward transition to the high state. A power spectrum is expected if it is assumed that the universe Compton effect is the basic mechanism that produces the hard X-ray tail of Cyg X-1. Spectral time variation may be caused by a varying intensity of an inner soft photon source within a stable hot cloud. (U.K.)

  4. NuSTAR discovery of a luminosity dependent cyclotron line energy in Vela X-1

    DEFF Research Database (Denmark)

    Fuerst, Felix; Pottschmidt, Katja; Wilms, Joern

    2014-01-01

    of the harmonic CRSF is correlated with flux, as expected in the sub-critical accretion regime. We argue that Vela X-1 has a very narrow accretion column with a radius of around 0.4 km that sustains a Coulomb interaction dominated shock at the observed luminosities of Lx ~ 3x10^36 erg/s. Besides the prominent...... of the line energies is variable with time and deviates significantly from 2.0, also a possible consequence of photon spawning, which changes the shape of the line. During the second observation, Vela X-1 showed a short off-state in which the power-law softened and a cut-off was no longer measurable...

  5. e-EVN radio detection of Aql X-1 in outburst

    Science.gov (United States)

    Tudose, V.; Paragi, Z.; Yang, J.; Miller-Jones, J. C. A.; Fender, R.; Garrett, M.; Rushton, A.; Spencer, R.

    2013-06-01

    The neutron star X-ray binary Aql X-1 is currently in outburst (ATel #5114, #5117, #5129, #5136, #5148). Using the European VLBI Network (e-EVN) we observed Aql X-1 at 5 GHz in two time-slots: 2013 June 18 between 19:48 - 20:36 UT (MJD 56461.825 - 56461.858), and 2013 June 19 between 02:53 - 05:54 UT (MJD 56462.120 - 56462.246). The two datasets were combined together and then calibrated. The participating radio telescopes were: Effelsberg (Germany), Jodrell Bank Mk2 (UK), Medicina (Italy), Noto (Italy), Onsala 25m (Sweden), Torun (Poland), Yebes (Spain), Westerbork Synthesis Radio Telescope (Netherlands), Shanghai (China), Hartebeesthoek (South Africa).

  6. Short-term variability of Cyg X-1 and the accretion disk temperature fluctuation

    International Nuclear Information System (INIS)

    Doi, K.

    1980-01-01

    Recent theoretical models which have been proposed to explain the observed time-averaged spectrum of Cyg X-1 assume that the hard x-rays are emitted by inverse-Compton mechanism from an optically thin, hot accretion disk around a black hole. Results are reported here of balloon observations (20-68 keV) and compared with previous rocket observations (1.5-25 keV). Using the results an analysis is made of the variability of the source intensity in the hard x-ray range which suggests that the variation is essentially spectral indicating that it originated from temperature fluctuation in an accretive disk. Such a model, which explains the stochastic nature of the variability, its characteristic time scale and spectral features at the same time in the context of the conventional accretion disk model for Cyg X-1, is examined. (U.K.)

  7. Swift-XRT detects X-ray burst from Circinus X-1

    NARCIS (Netherlands)

    Linares, M.; Soleri, P.; Altamirano, D.; Armas-Padilla, M.; Cavecchi, Y.; Degenaar, N.; Kalamkar, M.; Kaur, R.; van der Klis, M.; Patruno, A.; Watts, A.; Wijnands, R.; Yang, Y.; Casella, P.; Rea, N.; Chakrabarty, D.; Homan, J.

    Following the recent re-brightening (ATel #2608) and RXTE-PCA detection of X-ray bursts from the peculiar X-ray binary Cir X-1 between May 15 and 25 (ATel #2643), we obtained a series of Swift-XRT observations of the field (see also ATel #2650). Swift-XRT detected an X-ray burst on 2010-05-28 at

  8. Desorption dynamics of deuterium molecules from the Si(100)-(3x1) dideuteride surface.

    Science.gov (United States)

    Niida, T; Tsurumaki, H; Namiki, A

    2006-01-14

    We measured polar angle (theta)-resolved time-of-flight spectra of D2 molecules desorbing from the Si(100)-(3x1) dideuteride surface. The desorbing D2 molecules exhibit a considerable translational heating with mean desorption kinetic energies of approximately 0.25 eV, which is mostly independent of the desorption angles for 0 degreesdynamics of deuterium was discussed along the principle of detailed balance to predict their adsorption dynamics onto the monohydride Si surface.

  9. A possible very high energy gamma-ray burst from Hercules X-1

    International Nuclear Information System (INIS)

    Vishwanath, P.R.; Bhat, P.N.; Ramanamurthy, P.V.; Sreekantan, B.V.

    1989-01-01

    A large increase is observed in the trigger rate in the direction of Hercules X-1 in the Atmospheric Cerenkov array at Pachmarhi, India. The burst lasted from 2147 UT to 2201 UT on April 11, 1986. The accidental coincidence rate did not show any increase during the burst. Barring any electronic noise or celestial or terrestrial optical phenomenon with time structure similar to that of atmospheric Cerenkov phenomenon, the increase is ascribed to TeV gamma rays from Her X-1. The number of gamma-ray events during the burst amounted to about 54 percent of the cosmic-ray flux, resulting in a 42-sigma effect. This is the largest TeV gamma-ray signal seen from any source till now. The time-averaged flux for the burst period is 1.8 x 10 photons/sq cm per s above a threshold energy of 0.4 TeV, which results in a luminosity of 1.8 x 10 to the 37 ergs/s. The burst took place at the end of the 'high on' state in the 35-day cycle of the Her X-1 binary system indicating accretion disk as the possible production site. 14 refs

  10. Adsorption of Na on Ge(001)(2x1) surface

    International Nuclear Information System (INIS)

    Xiao, H.Y.; Zu, X.T.

    2006-01-01

    The adsorption of sodium on the Ge(001)(2x1) surface at the coverage (Θ) of 0.5 and 1ML has been investigated by using ab initio total energy calculations. It was found that at Θ=0.5ML T3 and T4 sites are nearly degenerate and Na adatoms preferred to adsorb at T3 and T4 sites. This finding agrees well with Meyerheim et al.'s experimental results, but does not support theoretical investigations of Spiess et al., who found HH site was the most stable. For 1ML coverage the most stable configurations are a combination of the HH and T3 or T4 sites. Work function and dipole moment analysis showed that upon Na adsorption on Ge(001)(2x1) and Si(001)(2x1) surface the dipole-dipole repulsion is small and no depolarization effect occurs as the coverage increases from 0.5 to 1ML

  11. Optical pulstions from HZ Herculis/Hercules X-1: The self-consistent 35 day picture

    International Nuclear Information System (INIS)

    Middleditch, J.

    1983-01-01

    A detailed analysis of the optical pulsation data from HZ Her shows that all of the 35 day characteristics can be interpreted in the light of episodic mass transfer every 0.81 days lasting at least 4 hr and obscuration by a tilted accretion disk which undergoes one cycle of retrograded progression every approx.35 days. The predominant systematic shifts of the optical pulsation velocities can be related to the X-ray shadowing of the phid.7 = 0.75 side of the lobe of HZ Her by the mass transfer stream and the associated disk rim structure. In the context of this new understanding of the 35 day effects, the pulsation data strongly affirm the assumptions of prograde spin for Her X-1, and aligned corotation and Roche lobe filling for HZ Her. Consideration of the accurately measured X-ray eclipse duration and the minimum orbital co-inclination required to produce the observed 35 day optical and X-ray variability may limit the Her X-1 mass to less than 1.4 M/sub sun/. A good model atmosphere for the optical pulsations could reduce the Her X-1 mass error to less than 0.10 M/sub sun/

  12. Observation of Cyg X-1 with the K-10-11 rocket

    International Nuclear Information System (INIS)

    Doi, Tsunenari; Matsuoka, Masaru; Miyamoto, Shigenori; Oda, Minoru; Ogawara, Yoshiaki

    1976-01-01

    The X-ray emission mechanism owing to the mass accretion to compact objects is one of cosmic X-ray sources. White dwarf, neutron star and black hole are considered as the compact objects. The mass of Cyg X-1 has been estimated to be about 10 times as large as the mass of the sun, and Cyg X-1 is only one prominent candidate for the black hole. The observation of the X-ray from Cyg C-1 provides the useful information on the physical state of the black hole. Particularly, the X-ray from Cyg X-1 showed the characteristic time variations which have not been detected in other X-ray sources. They are the intensive time variation over the duration of msec to day, the pulsation of about 1 msec breadth, and the transition between two X-ray emission states. The X-ray detector abroad the K-10-11 rocket is the proportional counter filled with 90% Xe and 10% CO 2 , and covers the 1.5-2.5 kev X-ray energy range. The total detector area is about 950 cm 2 . The observed result showed the characteristic intensive time variation and the msec pulsation. The data analysis is now in progress, and the preliminary result will be reported. (Yoshimori, M.)

  13. Alternative Explanations for Extreme Supersolar Iron Abundances Inferred from the Energy Spectrum of Cygnus X-1

    Science.gov (United States)

    Tomsick, John A.; Parker, Michael L.; García, Javier A.; Yamaoka, Kazutaka; Barret, Didier; Chiu, Jeng-Lun; Clavel, Maïca; Fabian, Andrew; Fürst, Felix; Gandhi, Poshak; Grinberg, Victoria; Miller, Jon M.; Pottschmidt, Katja; Walton, Dominic J.

    2018-03-01

    Here we study a 1–200 keV energy spectrum of the black hole binary Cygnus X-1 taken with NuSTAR and Suzaku. This is the first report of a NuSTAR observation of Cyg X-1 in the intermediate state, and the observation was taken during the part of the binary orbit where absorption due to the companion’s stellar wind is minimal. The spectrum includes a multi-temperature thermal disk component, a cutoff power-law component, and relativistic and nonrelativistic reflection components. Our initial fits with publicly available constant density reflection models (relxill and reflionx) lead to extremely high iron abundances (>9.96 and {10.6}-0.9+1.6 times solar, respectively). Although supersolar iron abundances have been reported previously for Cyg X-1, our measurements are much higher and such variability is almost certainly unphysical. Using a new version of reflionx that we modified to make the electron density a free parameter, we obtain better fits to the spectrum even with solar iron abundances. We report on how the higher density ({n}e=({3.98}-0.25+0.12)× {10}20 cm‑3) impacts other parameters such as the inner radius and inclination of the disk.

  14. Terahertz spectroscopy of 25MgH (X2Σ+) and (67)ZnH (X2Σ+): bonding in simple metal hydrides.

    Science.gov (United States)

    Bucchino, Matthew P; Ziurys, Lucy M

    2013-10-03

    Pure rotational spectra of (25)MgH (X(2)Σ(+)) and (67)ZnH (X(2)Σ(+)) were recorded using direct absorption techniques. These free radicals were synthesized by the reaction of metal vapor, generated in a Broida-type oven, with H2 in a dc discharge. The N = 0 → 1 and N = 1 → 2 transitions were recorded for both species in the frequency range 342-789 GHz. Spin-rotation and metal and proton hyperfine interactions were resolved in the spectra. From these data, rotational, fine structure, and hyperfine constants were determined, including the Fermi contact, dipolar, and electric quadrupole parameters of the (25)Mg and (67)Zn nuclei. Comparison of the metal and proton hyperfine terms suggests that the unpaired electron resides in a σ molecular orbital that has significant s contributions from both the metal and the hydrogen atoms. The dipolar terms for both metals are relatively large, in contrast to those of the proton, and indicate spσ and possibly sdσ (zinc only) orbital hybridization. The quadrupole constants arise principally from the p/d orbital character of the unpaired electron, although there is a non-negligible polarization contribution. These results suggest significant covalent character in both MgH and ZnH, in contrast to their fluoride analogs.

  15. EVIDENCE FOR AN INTERMEDIATE-MASS BLACK HOLE IN NGC 5408 X-1

    International Nuclear Information System (INIS)

    Strohmayer, Tod E.; Mushotzky, Richard F.

    2009-01-01

    We report the discovery with XMM-Newton of correlated spectral and timing behavior in the ultraluminous X-ray source (ULX) NGC 5408 X-1. An ∼100 ks pointing with XMM/Newton obtained in 2008 January reveals a strong 10 mHz quasi-periodic oscillation (QPO) in the >1 keV flux, as well as flat-topped, band-limited noise breaking to a power law. The energy spectrum is again dominated by two components, a 0.16 keV thermal disk and a power law with an index of ∼2.5. These new measurements, combined with results from our previous 2006 January pointing in which we first detected QPOs, show for the first time in a ULX a pattern of spectral and temporal correlations strongly analogous to that seen in Galactic black hole (BH) sources, but at much higher X-ray luminosity and longer characteristic timescales. We find that the QPO frequency is proportional to the inferred disk flux, while the QPO and broadband noise amplitude (rms) are inversely proportional to the disk flux. Assuming that QPO frequency scales inversely with the BH mass at a given power-law spectral index we derive mass estimates using the observed QPO frequency-spectral index relations from five stellar-mass BH systems with dynamical mass constraints. The results from all sources are consistent with a mass range for NGC 5408 X-1 from 1000 to 9000 M sun . We argue that these are conservative limits, and a more likely range is from 2000 to 5000 M sun . Moreover, the recent relation from Gierlinski et al. that relates the BH mass to the strength of variability at high frequencies (above the break in the power spectrum) is also indicative of such a high mass for NGC 5408 X-1. Importantly, none of the above estimates appears consistent with a BH mass less than ∼1000 M sun for NGC 5408 X-1. We argue that these new findings strongly support the conclusion that NGC 5408 X-1 harbors an intermediate-mass BH.

  16. Impaired P2X1 Receptor-Mediated Adhesion in Eosinophils from Asthmatic Patients.

    Science.gov (United States)

    Wright, Adam; Mahaut-Smith, Martyn; Symon, Fiona; Sylvius, Nicolas; Ran, Shaun; Bafadhel, Mona; Muessel, Michelle; Bradding, Peter; Wardlaw, Andrew; Vial, Catherine

    2016-06-15

    Eosinophils play an important role in the pathogenesis of asthma and can be activated by extracellular nucleotides released following cell damage or inflammation. For example, increased ATP concentrations were reported in bronchoalveolar lavage fluids of asthmatic patients. Although eosinophils are known to express several subtypes of P2 receptors for extracellular nucleotides, their function and contribution to asthma remain unclear. In this article, we show that transcripts for P2X1, P2X4, and P2X5 receptors were expressed in healthy and asthmatic eosinophils. The P2X receptor agonist α,β-methylene ATP (α,β-meATP; 10 μM) evoked rapidly activating and desensitizing inward currents (peak 18 ± 3 pA/pF at -60 mV) in healthy eosinophils, typical of P2X1 homomeric receptors, which were abolished by the selective P2X1 antagonist NF449 (1 μM) (3 ± 2 pA/pF). α,β-meATP-evoked currents were smaller in eosinophils from asthmatic patients (8 ± 2 versus 27 ± 5 pA/pF for healthy) but were enhanced following treatment with a high concentration of the nucleotidase apyrase (17 ± 5 pA/pF for 10 IU/ml and 11 ± 3 pA/pF for 0.32 IU/ml), indicating that the channels are partially desensitized by extracellular nucleotides. α,β-meATP (10 μM) increased the expression of CD11b activated form in eosinophils from healthy, but not asthmatic, donors (143 ± 21% and 108 ± 11% of control response, respectively). Furthermore, α,β-meATP increased healthy (18 ± 2% compared with control 10 ± 1%) but not asthmatic (13 ± 1% versus 10 ± 0% for control) eosinophil adhesion. Healthy human eosinophils express functional P2X1 receptors whose activation leads to eosinophil αMβ2 integrin-dependent adhesion. P2X1 responses are constitutively reduced in asthmatic compared with healthy eosinophils, probably as the result of an increase in extracellular nucleotide concentration. Copyright © 2016 by The American Association of Immunologists, Inc.

  17. Crystal-field splitting in coadsorbate systems: c (2x2) CO/K/Ni (100)

    NARCIS (Netherlands)

    Hasselström, J.; Föhlisch, A.; Denecke, R.; Nilsson, A.; Groot, F.M.F. de

    2000-01-01

    It is demonstrated how the crystal field splitting (CFS) fine structure can be used to characterize a coadsor-bate system. We have applied K 2p x-ray absorption spectroscopy (XAS) to the c(2x2) CO/K/Ni(100) system. The CFS fine structure is shown to be sensitive to the the local atomic

  18. Geologic Map of the Challis 1°x2° Quadrangle, Idaho

    Data.gov (United States)

    Department of the Interior — The paper version of The geology of the Challis 1°x2° quadrangle, was compiled by Fred Fisher, Dave McIntyre and Kate Johnson in 1992. The geology was compiled on a...

  19. Uranium magnetism in UGa2 and U(Gasub(1-x)Alsub(x))2 compounds

    International Nuclear Information System (INIS)

    Ballou, R.

    1983-01-01

    Magnetism of intermetallic compounds of uranium is studied. A monocrystal of the highly anisotropic ferromagnetic material UGa 2 is studied by polarized neutron diffraction. Localisation of 5f electrons is evidenced. Magnetic structure of uranium in UGa 2 is determined. The pseudobinary compound U(Gasub(1-x)Alsub(x)) 2 is studied for crystal structure, ferromagnetism, paramagnetism, specific heat and resistivity [fr

  20. ANTIMONY HALIDES AND HgX2 (X = Cl, Br AMINE ADDUCTS: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    NDONGO GUEYE

    2013-12-01

    Full Text Available Eight new SbF3, SbCl5 and HgX2 (X = Cl, Br amine adducts have been synthesized and their infrared study carried out. Discrete structures have been suggested on the basis of elemental analysis and infrared data, the coordination number of antimony varying from five to nine, while the environment around Hg is tetrahedral.

  1. Structural and electronic properties of silicene on MgX2 (X = Cl, Br, and I)

    KAUST Repository

    Zhu, Jiajie; Schwingenschlö gl, Udo

    2014-01-01

    . The Si buckling height is below 0.55 Å, which is close to the value of free-standing silicene (0.49 Å). Importantly, the Dirac cone of silicene is well preserved on MgX2 (located slightly above the Fermi level), and the band gaps induced by the substrate

  2. Oxygen adsorption on Pt(110)-(1x2): new high-coverage structures

    DEFF Research Database (Denmark)

    Helveg, Stig; Lorensen, Henrik Qvist; Horch, Sebastian

    1999-01-01

    From an interplay between scanning tunneling microscopy (STM) experiments and density functional theory (DFT) calculations, a comprehensive picture is obtained for oxygen adsorption on the Pt(110)-(1 x 2) surface, from single isolated oxygen atoms chemisorbed in FCC sites along the platinum ridges...... adsorption and platinum lattice distortions. (C) 1999 Elsevier Science B.V. All rights reserved....

  3. Primes of the form x2 + dy2 with x ≡ 0(mod N)

    Indian Academy of Sciences (India)

    Department of Computer Science and Automation, Indian Institute of Science, ... This led many mathematicians to work on primes of the form x2 + dy2 for d = 2, 3, 5, 7 ..... Chandan Singh Dalawat, H.R.I. Allahabad, for the kind help and.

  4. Procrastination and the 2 x 2 Achievement Goal Framework in Malaysian Undergraduate Students

    Science.gov (United States)

    Ganesan, Rajalakshmi; Mamat, Norul Hidayah Bt; Mellor, David; Rizzuto, Laura; Kolar, Christina

    2014-01-01

    The present study investigated academic procrastination in the context of the 2 x 2 goal achievement theoretical framework within a population of 450 Malaysian undergraduate students, aged 18 to 25 years. Participants completed the Achievement Goal Questionnaire and the Tuckman Procrastination Test. Approach dimensions of both the mastery and…

  5. Role of the dimensionality of the [GaX]2 network in the Zintl phases EuGa2X2

    KAUST Repository

    Singh, Nirpendra

    2012-11-28

    The structural, electronic, magnetic, optical, and thermoelectric properties of EuGa2X2 (X = P, As, and Sb) are investigated using first principles calculations (taking into account the onsite Coulomb interaction) and the semi-classical Boltzmanntheory. The divalent nature of Eu fulfils the Zintl principle as is confirmed by the calculated total magnetic moments of ∼7 μB. A metallic behavior is obtained for all compounds. The optical spectra originate mainly from the transitions between occupied Eu 4f states and unoccupied Eu 5d states. It is demonstrated that the two-dimensional [Ga(P/As)]2 network in EuGa2P2 and EuGa2As2 is favorable for thermoelectric applications as compared to the three-dimensional [GaSb]2 network in EuGa2Sb2.

  6. Vibrational analysis of Fourier transform spectrum of the A3Π0–X1Σ ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 5. Vibrational analysis of Fourier transform spectrum of the A 3 0 – X 1 ∑ + and B 3 1 – X 1 ∑ + transitions of indium monobromide. Renu Singh K N Uttam M D Saksena M N Deo. Volume 73 Issue 5 November 2009 pp 889-899 ...

  7. WAS COMET C/1945 X1 (DU TOIT) A DWARF, SOHO-LIKE KREUTZ SUNGRAZER?

    Energy Technology Data Exchange (ETDEWEB)

    Sekanina, Zdenek [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Kracht, Rainer, E-mail: Zdenek.Sekanina@jpl.nasa.gov, E-mail: R.Kracht@t-online.de [Ostlandring 53, D-25335 Elmshorn, Schleswig-Holstein (Germany)

    2015-12-10

    The goal of this investigation is to reinterpret and upgrade the astrometric and other data on comet C/1945 X1, the least prominent among the Kreutz system sungrazers discovered from the ground in the twentieth century. The central issue is to appraise the pros and cons of a possibility that this object is—despite its brightness reported at discovery—a dwarf Kreutz sungrazer. We confirm Marsden’s conclusion that C/1945 X1 has a common parent with C/1882 R1 and C/1965 S1, in line with the Sekanina and Chodas scenario of their origin in the framework of the Kreutz system’s evolution. We integrate the orbit of C/1882 R1 back to the early twelfth century and then forward to around 1945 to determine the nominal direction of the line of apsides and perform a Fourier analysis to get insight into effects of the indirect planetary perturbations. To better understand the nature of C/1945 X1, its orbital motion, fate, and role in the hierarchy of the Kreutz system, as well as to attempt detecting the comet’s possible terminal outburst shortly after perihelion and answer the question in the title of this investigation, we closely examined the relevant Boyden Observatory logbooks and identified both the photographs with the comet’s known images and nearly 20 additional patrol plates, taken both before and after perihelion, on which the comet or traces of its debris will be searched for, once the process of their digitization, currently conducted as part of the Harvard College Observatory’s DASCH Project, has been completed and the scanned copies made available to the scientific community.

  8. NuSTAR discovery of a luminosity dependent cyclotron line energy in Vela X-1

    Energy Technology Data Exchange (ETDEWEB)

    Fürst, Felix; Grefenstette, Brian W.; Harrison, Fiona; Madsen, Kristin K.; Walton, Dominic J. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Pottschmidt, Katja [Center for Space Science and Technology, University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Wilms, Jörn [Dr. Karl-Remeis-Sternwarte and ECAP, Sternwartstr. 7, D-96049 Bamberg (Germany); Tomsick, John A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Bachetti, Matteo [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Miller, Jon M. [Department of Astronomy, The University of Michigan, Ann Arbor, MI 48109 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Zhang, William [NASA Goddard Space Flight Center, Astrophysics Science Division, Code 662, Greenbelt, MD 20771 (United States)

    2014-01-10

    We present NuSTAR observations of Vela X-1, a persistent, yet highly variable, neutron star high-mass X-ray binary (HMXB). Two observations were taken at similar orbital phases but separated by nearly a year. They show very different 3-79 keV flux levels as well as strong variability during each observation, covering almost one order of magnitude in flux. These observations allow, for the first time ever, investigations on kilo-second time-scales of how the centroid energies of cyclotron resonant scattering features (CRSFs) depend on flux for a persistent HMXB. We find that the line energy of the harmonic CRSF is correlated with flux, as expected in the sub-critical accretion regime. We argue that Vela X-1 has a very narrow accretion column with a radius of around 0.4 km that sustains a Coulomb interaction dominated shock at the observed luminosities of L {sub x} ∼ 3 × 10{sup 36} erg s{sup –1}. Besides the prominent harmonic line at 55 keV the fundamental line around 25 keV is clearly detected. We find that the strengths of the two CRSFs are anti-correlated, which we explain by photon spawning. This anti-correlation is a possible explanation for the debate about the existence of the fundamental line. The ratio of the line energies is variable with time and deviates significantly from 2.0, also a possible consequence of photon spawning, which changes the shape of the line. During the second observation, Vela X-1 showed a short off-state in which the power-law softened and a cut-off was no longer measurable. It is likely that the source switched to a different accretion regime at these low mass accretion rates, explaining the drastic change in spectral shape.

  9. SMM/HXRBS observations of Cygnus X-1 from 1986 December to 1988 April

    Science.gov (United States)

    Schwartz, R. A.; Orwig, L. E.; Dennis, B. R.; Ling, J. C.; Wheaton, W. A.

    1991-01-01

    The Solar Maximum Mission's Hard X-ray Burst Spectrometer made 30 measurements of Cygnus X-1 from December, 1986 to April, 1988, yielding a data set of broad synoptic coverage but limited duration for each data point. The hard X-ray intensity was found to be between the gamma(2) and gamma(3) levels, with a range of fluctuations about the average intensity level. The shape of the photon spectrum was found to be closest to that reported by Ling et al. (1983, 1987) during the time of the gamma(3) level emission, although the spectral shapes reported for the gamma(2) and gamma(1) levels were not precluded.

  10. Aql X-1 transition towards the soft (banana) state accompanied by radio/NIR detection

    Science.gov (United States)

    Sivakoff, G. R.; Miller-Jones, J.; Fox, O.; Linares, M.; Altamirano, D.; Russell, D.

    2009-11-01

    The currently active neutron star transient and atoll source Aql X-1 (Linares et al., ATEL #2288) has begun the transition from the hard (extreme island) state to the soft (banana) state (Rodriguez et al. ATEL #2299). This transition likely began around 2009 Nov 15 (MJD = 55150). The latest RXTE PCA observation (2009 Nov 17, MJD=55152.17+/-0.02, 2-60 keV fractional rms variability amplitude of ~11% for 0.1-10 Hz) indicates that the source is in the intermediate (island) state.

  11. The icon of defeat: the 7x1 construction by visual plasticity

    Directory of Open Access Journals (Sweden)

    Magnos Cassiano Casagrande

    2016-12-01

    Full Text Available The study investigates the 7x1 defeat of the Brazilian team in the football World Cup 2014 by the plasticity of the image. Plastic forces acting on the image analyzed by Villafañe (2000, Arnheim (1988 and Kandinsky (1997 reconstructed the fact itself. The analysis becomes more evident the strategic collaboration of the images used in newspaper front pages, in the formation of the general directions that newspaper text intends and shows the flexibility of the iconic to represent the real through visual elements such as color, point, textures and dimension.

  12. The showerfront time-structure of ''anomalous muon'' events associated with Hercules X-1

    International Nuclear Information System (INIS)

    Alexandreas, D.E.; Allen, R.C.; Biller, S.D.; Dion, G.M.; Lu, X-Q.; Vishwanath, P.R.; Yodh, G.B.; Berley, D.; Chang, C.Y.; Dingus, B.L.; Dion, C.; Goodman, J.A.; Gupta, S.K.; Haines, T.J.; Kwok, P.W.; Stark, M.J.; Burman, R.L.; Hoffman, C.M.; Lloyd-Evans, J.; Nagle, D.E.; Potter, M.E.; Sandberg, V.D.; Zhang, W.P.; Cady, D.R.; Ellsworth, R.W.; Krakauer, D.A.; Talaga, R.L.

    1990-01-01

    The 11 ''in-phase'' source events from the 1986 muon-rich bursts associated with Hercules X-1 (previously reported by this group) have been studied for indications of further anomalous behavior. The most significant effect observed resulted from an analysis of the showerfront time-structures of these events. This analysis was then applied a priori to the rest of the source day, where an additional ∼9 signal events are expected to remain. The same effect was observed at a chance probability level of ∼0.1%. 1 ref., 7 figs

  13. Vibration-rotation spectrum of BH X1Σ+ by Fourier transform emission spectroscopy

    Science.gov (United States)

    Pianalto, F. S.; O'Brien, L. C.; Keller, P. C.; Bernath, P. F.

    1988-06-01

    The vibration-rotation emission spectrum of the BH X1Σ+ state was observed with the McMath Fourier transform spectrometer at Kitt Peak. The 1-0, 2-1, and 3-2 bands were observed in a microwave discharge of B2H6 in He. Spectroscopic constants of the individual vibrational levels and equilibrium molecular constants were determined. An RKR potential curve was calculated from the equilibrium constants. Alfred P. Sloan Fellow; Camille and Henry Dreyfus Teacher-Scholar.

  14. Spin-resolved photoemission of surface states of W(110)-(1x1)H

    International Nuclear Information System (INIS)

    Hochstrasser, M.; Tobin, J.G.; Rotenberg, Eli; Kevan, S.D.

    2002-01-01

    The surface electronic states of W(110)-(1x1)H have been measured using spin- and angle-resolved photoemission. We directly demonstrate that the surface bands are both split and spin-polarized by the spin-orbit interaction in association with the loss of inversion symmetry near a surface. We observe 100 percent spin polarization of the surface states, with the spins aligned in the plane of the surface and oriented in a circular fashion relative to the S-bar symmetry point. In contrast, no measurable polarization of nearby bulk states is observed

  15. X-ray and UV spectroscopy of Cygnus X-1 = HDE226868

    Science.gov (United States)

    Pravdo, S. H.; White, N. E.; Kondo, Y.; Becker, R. H.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Mccluskey, B. G.

    1980-01-01

    Observations are presented of Cygnus X-1 with the solid-state spectrometer on the Einstein Observatory. The X-ray spectra of two intensity dips viewed near superior conjunction did not exhibit increased photoelectric absorption. Rather the data support a model in which an increase in the electron scattering optical depth modifies both the observed spectrum and the intensity. The characteristic temperature of the intervening material is greater than 5 x 10 to the 7th power K. These measurements were in part simultaneous with observations by IUE. The ultra violet spectrum and intensity remained relatively constant during an X-ray intensity dip.

  16. All-fiber 7x1 signal combiner for incoherent laser beam combining

    DEFF Research Database (Denmark)

    Noordegraaf, Danny; Maack, Martin D.; Skovgaard, Peter M. W.

    2011-01-01

    We demonstrate an all-fiber 7x1 signal combiner for incoherent laser beam combining. This is a potential key component for reaching several kW of stabile laser output power. The combiner couples the output from 7 single-mode (SM) fiber lasers into a single multi-mode (MM) fiber. The input signal ...... in device temperature is observed. At an intermediate power level of 600 W a beam parameter product (BPP) of 2.22 mm x mrad is measured, corresponding to an M2 value of 6.5. These values are approaching the theoretical limit dictated by brightness conservation....

  17. An extended X-ray low state from Hercules X-1

    International Nuclear Information System (INIS)

    Parmar, A.N.; White, N.E.; Barr, P.; Pietsch, W.; Truemper, J.; Voges, W.; McKechnie, S.

    1985-01-01

    Hercules X-1 exhibits a 35-day cycle in its X-ray intensity in addition to its pulsar rotational and orbital periodicities of 1.24s and 1.7 days respectively. The authors report here observations made with the EXOSAT Observatory between 1983 June and August that failed to detect the expected 35-day variation in X-ray intensity, although low-level extended X-ray emission was seen. The EXOSAT observations suggest that a temporary change in the disk structure may have occurred such that the disk was in the line of sight throughout. (author)

  18. Observation of hard X-rays line emission from Her X-1

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, V.F.; Bazzano, A.; la Padula, C.; Ubertini, P.; Vialetto, G.; Manchanda, R.K.; Damle, S.V.

    1982-04-01

    We present the results of a hard X-ray measurement of the binary source Her X-1, carried out with a balloon borne X-ray telescope consisting of two Multiwire Proportional Counters, having 900 cm/sup 2/ sensitive area each and spectral resolution of 15% and 24% FWHM respectively at 60 keV. The source was observed during the 'Mid-on' state. Our data confirm the previously reported high energy emission line overimposed on the low energy thermal spectrum.

  19. Long-term gamma-ray spectral variability of Cygnus X-1

    International Nuclear Information System (INIS)

    Ling, J.C.; Mahoney, W.A.; Wheaton, WM.A.; Jacobson, A.S.

    1987-01-01

    Data from HEAO 3 observations of 0.05-10-MeV gamma-ray emission from Cyg X-1 during two 90-d periods (in fall 1979 and spring 1980) are compiled in tables and graphs and analyzed statistically to determine the temporal and spectral variability. It is found that a steady increase in 100-keV emission is accompanied by a decrease (and eventual disappearance) of MeV emission. The mechanisms which could theoretically be responsible for these phenomena are discussed. 28 references

  20. Free electron laser for the 2 x 1 TeV photon collider

    International Nuclear Information System (INIS)

    Sarantsev, V.P.; Yurkov, M.V.; Saldin, E.L.; Shnejdmiller, E.A.

    1993-01-01

    The two-cascade scheme of a free electron laser (FEL) of the 2 x 1 TeV photon collider is suggested. The FEL-generator having peak power of ∼ 10 MW which is amplified up to 5 x 10 11 W in the FEL-amplifier with variable parameters is used as a driving laser. Requirements for parameters of electron beam and the FEL-amplifier magnetic system are formulated on the base of calculations. 19 refs., 2 tabs., 4 figs

  1. The icon of defeat: the 7x1 construction by visual plasticity

    OpenAIRE

    Magnos Cassiano Casagrande; Fabiano Maggioni

    2016-01-01

    The study investigates the 7x1 defeat of the Brazilian team in the football World Cup 2014 by the plasticity of the image. Plastic forces acting on the image analyzed by Villafañe (2000), Arnheim (1988) and Kandinsky (1997) reconstructed the fact itself. The analysis becomes more evident the strategic collaboration of the images used in newspaper front pages, in the formation of the general directions that newspaper text intends and shows the flexibility of the iconic to represent the real th...

  2. Optical and radio counterpart of Circinus X-1 (3U 1516-56)

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, J A.J.; Murdin, P G; Peterson, B A [Anglo-Australian Observatory, Epping (Australia); and others

    1977-11-01

    Circinus X-1 (3U 1516-56) has a radio counterpart which, at high frequencies, show flares with the same 16.6 day periodicity as the X-ray intensity. In each cycle the radio flare occurs shortly after the intensity drop-off which defines the X-ray modulation. The radio source is positionally coincident with a faint red star having very strong H..cap alpha.. and weak He I emission lines which are probably variable. The object may be an early-type emission-line star or a symbiotic star, at a distance of 10 kpc.

  3. The mass of the black hole in the X-ray binary LMC X-1

    Science.gov (United States)

    Abubekerov, M. K.; Antokhina, E. A.; Gostev, N. Yu.; Cherepashchuk, A. M.; Shimansky, V. V.

    2016-12-01

    A dynamical estimate of the mass of the black hole in the LMC X-1 binary system is obtained in the framework of a Roche model for the optical star, based on fitting of the He I 4471 Å and He II 4200 Å absorption lines assuming LTE. The mass of the black hole derived from the radial-velocity curve for the He II 4200 Å line is m x = 10.55 M ⊙, close to the value found earlier based on a model with two point bodies [1].

  4. Observation of Hercules X-1 at energies above 50 TeV

    International Nuclear Information System (INIS)

    Dingus, B.L.; Chang, C.Y.; Goodman, J.A.

    1988-01-01

    A search for emission from Hercules X-1 at energies above 50 TeV during the calendar period April 1986 to July 1987 yielded two significant bursts, on UT 24 July 1986. The events during these bursts were pulsed with a period of 1.2357 s, significantly different from estimates of the contemporaneous x-ray period. The probability that this represents random statistical fluctuations of the background is estimated to be 1/70000. The muon content of the burst events is anomalous when compared with expectations from gamma-ray showers. 11 refs., 1 fig

  5. Maximizing Entropy of Pickard Random Fields for 2x2 Binary Constraints

    DEFF Research Database (Denmark)

    Søgaard, Jacob; Forchhammer, Søren

    2014-01-01

    This paper considers the problem of maximizing the entropy of two-dimensional (2D) Pickard Random Fields (PRF) subject to constraints. We consider binary Pickard Random Fields, which provides a 2D causal finite context model and use it to define stationary probabilities for 2x2 squares, thus...... allowing us to calculate the entropy of the field. All possible binary 2x2 constraints are considered and all constraints are categorized into groups according to their properties. For constraints which can be modeled by a PRF approach and with positive entropy, we characterize and provide statistics...... of the maximum PRF entropy. As examples, we consider the well known hard square constraint along with a few other constraints....

  6. Prediction of intrinsic motivation and sports performance using 2 x 2 achievement goal framework.

    Science.gov (United States)

    Li, Chiung-Huang; Chi, Likang; Yeh, Suh-Ruu; Guo, Kwei-Bin; Ou, Cheng-Tsung; Kao, Chun-Chieh

    2011-04-01

    The purpose of this study was to examine the influence of 2 x 2 achievement goals on intrinsic motivation and performance in handball. Participants were 164 high school athletes. All completed the 2 x 2 Achievement Goals Questionnaire for Sport and the Intrinsic Motivation subscale of the Sport Motivation Scale; the coach for each team rated his athletes' overall sports performance. Using simultaneous-regression analyses, mastery-approach goals positively predicted both intrinsic motivation and performance in sports, whereas performance-avoidance goals negatively predicted sports performance. These results suggest that athletes who pursue task mastery and improvement of their competence perform well and enjoy their participation. In contrast, those who focus on avoiding normative incompetence perform poorly.

  7. Design and construction of the X-2 two-stage free piston driven expansion tube

    Science.gov (United States)

    Doolan, Con

    1995-01-01

    This report outlines the design and construction of the X-2 two-stage free piston driven expansion tube. The project has completed its construction phase and the facility has been installed in the new impulsive research laboratory where commissioning is about to take place. The X-2 uses a unique, two-stage driver design which allows a more compact and lower overall cost free piston compressor. The new facility has been constructed in order to examine the performance envelope of the two-stage driver and how well it couple to sub-orbital and super-orbital expansion tubes. Data obtained from these experiments will be used for the design of a much larger facility, X-3, utilizing the same free piston driver concept.

  8. Accelerated testing of fuel cell components in 2 x 2 inch fuel cells

    International Nuclear Information System (INIS)

    Coleman, A.J.; Adams, A.A.; Joebstl, J.A.; Walker, G.W.

    1981-01-01

    A description is presented of diagnostic procedures which can be used to predict failure modes and assess the effects of these failures on fuel cell performance. Some straightforward diagnostic techniques have been used to evaluate fuel cells assembled with a variety of matrix and electrode combinations. These techniques included accelerated on-off cycling, thermal cycling with H2/CO mixtures, and automatic polarization measurements. Information has been obtained concerning the effects of electrolyte management and catalyst poisoning on performance and lifetime characteristics of 2 x 2 in. single cells. The use of on-off cycling has shown that short-term fuel cell performance is generally unaffected by load changes and cycle sequence in 2 x 2 in. cells when electrolyte management is adequate. Dynamic polarization curves can be used instead of point by point steady-state plots without any loss in accuracy

  9. Line structures in the X-ray spectra of Cygnus X-2 observed with Exosat

    Science.gov (United States)

    Freeman, P. E.; Kahn, S. M.; Chiappetti, L.; Tanzi, E. G.; Ciapi, A.; Maraschi, L.; Treves, A.; Branduardi-Raymont, E. G.; Ercan, E. N.

    1990-01-01

    Cygnus X-2 was observed with Exosat at five phases of a single orbital cycle in September of 1983. The results of spectral fits of the LE + ME (Argon) data are summarized in terms of a superposition of thermal bremsstrahlung and blackbody components. During the first observation, a grating spectrum was obtained, and this is described in some detail. The GSPC data are used to investigate the presence of iron features and their behavior during dips.

  10. NMR study of (Y1-xLax) Mn2X2 (X = Ge, Si) compounds

    International Nuclear Information System (INIS)

    Ichinose, K.; Nagai, H.; Tsujimura, A.; Oyasato, M.

    1988-01-01

    Nuclear magnetic resonances of 55 Mn and 139 La nuclei in (Y 1-x La x ) Mn 2 X 2 (X = Ge, Si) have been observed at 4.2 K in their ferromagnetic state for 0.3 ≤ x ≤ 1. The hyperfine fields at these nuclei are independent of La concentration. This result shows that Mn moment is almost constant when replacing Y with La

  11. Energetics and dynamics of Pt dimers on Pt(110)-(1x2)

    International Nuclear Information System (INIS)

    Linderoth, T.R.; Horch, S.; Petersen, L.; Helveg, S.; Schoenning, M.; Laegsgaard, E.; Stensgaard, I.; Besenbacher, F.

    2000-01-01

    The stability and dynamics of Pt dimers on Pt(110)-(1x2) are studied using fast-scanning, variable-temperature STM. The kinetics of both dissociation and association of dimers have been quantified from a direct analysis of time-lapse STM movies. The extracted barriers are at variance with results from ab initio calculations, and we speculate that the discrepancies are due to trace amounts of gas impurities such as CO

  12. On the morphology of outbursts of accreting millisecond X-ray pulsar Aquila X-1

    Science.gov (United States)

    Güngör, C.; Ekşi, K. Y.; Göğüş, E.

    2017-10-01

    We present the X-ray light curves of the last two outbursts - 2014 & 2016 - of the well known accreting millisecond X-ray pulsar (AMXP) Aquila X-1 using the monitor of all sky X-ray image (MAXI) observations in the 2-20 keV band. After calibrating the MAXI count rates to the all-sky monitor (ASM) level, we report that the 2016 outburst is the most energetic event of Aql X-1, ever observed from this source. We show that 2016 outburst is a member of the long-high class according to the classification presented by Güngör et al. with ˜ 68 cnt/s maximum flux and ˜ 60 days duration time and the previous outburst, 2014, belongs to the short-low class with ˜ 25 cnt/s maximum flux and ˜ 30 days duration time. In order to understand differences between outbursts, we investigate the possible dependence of the peak intensity to the quiescent duration leading to the outburst and find that the outbursts following longer quiescent episodes tend to reach higher peak energetic.

  13. The Extreme Spin of the Black Hole in Cygnus X-1

    Science.gov (United States)

    Gou, Lijun; McClintock, Jeffrey E.; Reid, Mark J.; Orosz, Jerome A.; Steiner, James F.; Narayan, Ramesh; Xiang, Jingen; Remillard, Ronald A.; Arnaud, Keith A.; Davis, Shane W.

    2011-01-01

    The compact primary in the X-ray binary Cygnus X-1 was the first black hole to be established via dynamical observations. We have recently determined accurate values for its mass and distance, and for the orbital inclination angle of the binary. Building on these results, which are based on our favored (asynchronous) dynamical model, we have measured the radius of the inner edge of the black hole s accretion disk by fitting its thermal continuum spectrum to a fully relativistic model of a thin accretion disk. Assuming that the spin axis of the black hole is aligned with the orbital angular momentum vector, we have determined that Cygnus X-1 contains a near-extreme Kerr black hole with a spin parameter a* > 0.95 (3(sigma)). For a less probable (synchronous) dynamical model, we find a. > 0.92 (3 ). In our analysis, we include the uncertainties in black hole mass, orbital inclination angle, and distance, and we also include the uncertainty in the calibration of the absolute flux via the Crab. These four sources of uncertainty totally dominate the error budget. The uncertainties introduced by the thin-disk model we employ are particularly small in this case given the extreme spin of the black hole and the disk s low luminosity.

  14. Molecular dynamics simulation of boron implanted into diamond (0 0 1) 2 x 1 reconstruction surface

    International Nuclear Information System (INIS)

    Li Rongbin; Dai Yongbin; Hu Xiaojun; Sheng Heshen; He Xianchang

    2003-01-01

    Molecular dynamic simulations, utilizing the Tersoff many-body potential, are used to investigate the microscopic processes of a single boron atom with energy of 500 eV implanted into the diamond (0 0 1) 2 x 1 reconstruction surface. The lifetime of thermal spike created by B bombardment is about 0.18 ps by calculating the variation of the mean coordination numbers with time. The formation of the split-interstitial composed of projectile and lattice atom (B-C) is observed. The total potential energy of the system decreases about 0.56 eV with a stable B split-interstitial in diamond. The lattice relaxations in the diamond (0 0 1) 2 x 1 reconstruction surface or near surface of simulated have been discussed. The outermost layer atoms tend to move inward, and the other atoms move outward. The interplanar distance between the outermost layer and the second layer has been shortened by 15% compared with its starting interplanar distance. Stress distribution in the calculated diamond configuration is inhomogeneous. After boron implanted into diamond with the energy of 500 eV, there is an excess of compressively stressed atoms in the lattice, which induces the total stress being compressive

  15. Spectral state transitions of the Ultraluminous X-ray Source IC 342 X-1

    Science.gov (United States)

    Marlowe, H.; Kaaret, P.; Lang, C.; Feng, H.; Grisé, F.; Miller, N.; Cseh, D.; Corbel, S.; Mushotzky, R. F.

    2014-10-01

    We observed the Ultraluminous X-ray Source (ULX) IC 342 X-1 simultaneously in X-ray and radio with Chandra and the JVLA to investigate previously reported unresolved radio emission coincident with the ULX. The Chandra data reveal a spectrum that is much softer than observed previously and is well modelled by a thermal accretion disc spectrum. No significant radio emission above the rms noise level was observed within the region of the ULX, consistent with the interpretation as a thermal state though other states cannot be entirely ruled out with the current data. We estimate the mass of the black hole using the modelled inner disc temperature to be 30 M_{⊙} ≲ M√{cosi}≲ 200 M_{⊙} based on a Shakura-Sunyaev disc model. Through a study of the hardness and high-energy curvature of available X-ray observations, we find that the accretion state of X-1 is not determined by luminosity alone.

  16. X1: A Robotic Exoskeleton for In-Space Countermeasures and Dynamometry

    Science.gov (United States)

    Rea, Rochelle; Beck, Christopher; Rovekamp, Roger; Diftler, Myron; Neuhaus, Peter

    2013-01-01

    Bone density loss and muscle atrophy are among the National Aeronautics and Space Administration's (NASA) highest concerns for crew health in space. Countless hours are spent maintaining an exercise regimen aboard the International Space Station (ISS) to counteract the effect of zero-gravity. Looking toward the future, NASA researchers are developing new compact and innovative exercise technologies to maintain crew health as missions increase in length and take humans further out into the solar system. The X1 Exoskeleton, initially designed for assisted mobility on Earth, was quickly theorized to have far-reaching potential as both an in-space countermeasures device and a dynamometry device to measure muscle strength. This lower-extremity device has the ability to assist or resist human movement through the use of actuators positioned at the hips and knees. Multiple points of adjustment allow for a wide range of users, all the while maintaining correct joint alignment. This paper discusses how the X1 Exoskeleton may fit NASA's onorbit countermeasures needs.

  17. Long term variability of Cygnus X-1. V. State definitions with all sky monitors

    Science.gov (United States)

    Grinberg, V.; Hell, N.; Pottschmidt, K.; Böck, M.; Nowak, M. A.; Rodriguez, J.; Bodaghee, A.; Cadolle Bel, M.; Case, G. L.; Hanke, M.; Kühnel, M.; Markoff, S. B.; Pooley, G. G.; Rothschild, R. E.; Tomsick, J. A.; Wilson-Hodge, C. A.; Wilms, J.

    2013-06-01

    We present a scheme for determining the spectral state of the canonical black hole Cyg X-1 using data from previous and current X-ray all sky monitors (RXTE-ASM, Swift-BAT, MAXI, and Fermi-GBM). Determinations of the hard/intermediate and soft state agree to better than 10% between different monitors, facilitating the determination of the state and its context for any observation of the source, potentially over the lifetimes of different individual monitors. A separation of the hard and the intermediate states, which strongly differ in their spectral shape and short-term timing behavior, is only possible when data in the soft X-rays (probability of Cyg X-1 remaining in a given state for at least one week to be larger than 85% in the hard state and larger than 75% in the soft state. Intermediate states are short lived, with a 50% probability that the source leaves the intermediate state within three days. Reliable detection of these potentially short-lived events is only possible with monitor data that have a time resolution better than 1 d.

  18. Optical pulsation from the HZ Her/Her X-1 system

    International Nuclear Information System (INIS)

    Chester, T.J.

    1977-01-01

    A theoretical model for the observed optical pulsation from the x-ray binary HZ Her/Her X-1 is presented. Its foundation is a general computer code for an x-ray illuminated stellar atmosphere. Detailed results are given for several atmospheres applicable to HZ Her. A formalism is developed to calculate the amount of pulsed optical radiation emergent from these atmospheres if they are exposed to pulsed x rays. This formalism is used to calculate the pulsed and unpulsed optical light curves for HZ Her. The calculated optical pulsation agrees with the observed amplitude. A nonuniform x-ray beam can cause the amplitude and velocity of the optical pulsation to vary by more than a factor of two for fixed system parameters. The presence of soft x rays (0.1 to 1 keV) can significantly affect the calculated pulsation amplitude. The model places explicit limits on the system parameters; in particular, if corotation is assumed, 0.8 M/sub sun/ less than or equal to M/sub Her X-1/ less than or equal to 1.7 M/sub sun/

  19. The Nature and Cause of Spectral Variability in LMC X-1

    Science.gov (United States)

    Ruhlen, L.; Smith, D. M.; Scank, J. H.

    2011-01-01

    We present the results of a long-term observation campaign of the extragalactic wind-accreting black-hole X-ray binary LMC X-1, using the Proportional Counter Array on the Rossi X-Ray Timing Explorer (RXTE). The observations show that LMC X-1's accretion disk exhibits an anomalous temperature-luminosity relation. We use deep archival RXTE observations to show that large movements across the temperature-luminosity space occupied by the system can take place on time scales as short as half an hour. These changes cannot be adequately explained by perturbations that propagate from the outer disk on a viscous timescale. We propose instead that the apparent disk variations reflect rapid fluctuations within the Compton up-scattering coronal material, which occults the inner parts of the disk. The expected relationship between the observed disk luminosity and apparent disk temperature derived from the variable occultation model is quantitatively shown to be in good agreement with the observations. Two other observations support this picture: an inverse correlation between the flux in the power-law spectral component and the fitted inner disk temperature, and a near-constant total photon flux, suggesting that the inner disk is not ejected when a lower temperature is observed.

  20. Einstein SSS and MPC observations of Aql X-1 and 4U1820-30

    Science.gov (United States)

    Kelley, R. L.; Christian, D. J.; Schoelkopf, R. J.; Swank, J. H.

    1989-01-01

    The results of timing and spectral analyses of the X-ray sources Aql X-1 (X1908+005) and 4U1820-30 (NGC6624) are reported using data obtained with the Einstein SSS (Solid State Spectrometer) and MPC (Monitor Proportional Counter) instruments. A classic type I burst was observed from Aql X-1 in both detectors and a coherent modulation with a period of 131.66 + or - 0.02 ms and a pulsed fraction of 10 percent was detected in the SSS data. There is no evidence for a loss of coherance during the approximately 80 sec when the burst is observable. The 2 sigma upper limit on the rate of change of the pulse period is 0.00005s/s. It is argued that an asymmetrical burst occurring on a neutron star rotating at 7.6 Hz offers a plausible explanation for the oscillation. The data from 4U1820-30 show that the amplitude of the 685 sec modulation, identified as the orbital period, is independent of energy down to 0.6 keV. The SSS data show that the light curve in the 0.6 to 4.5 keV band is smoother than at higher energies.

  1. Optical spectrum of HDE 226868 = Cygnus X-1. II. Spectrophotometry and mass estimates

    International Nuclear Information System (INIS)

    Gies, D.R.; Bolton, C.T.

    1986-01-01

    In part I of this series, Gies and Bolton (1982) have presented the results of radial velocity measures of 78 high-dispersion spectrograms of HDE 226868 = Cyg X-1. For the present study, 55 of the best plates considered by Gies and Bolton were selected to form 10 average spectra. An overall mean spectrum with S/N ratio = 300 was formed by coadding the 10 averaged spectra. There is no evidence for statistically significant variations of the spectral type about the mean value of 09.7 Iab, and all the absorption line strengths are normal for the spectral type. Evidence is presented that the He II lambda 4846 emission line is formed in the stellar wind above the substellar point on the visible star. Probable values regarding the mass for the visible star and its companion are 33 and 16 solar masses, respectively. Theoretical He II lambda 4686 emission line profiles are computed for the focused stellar wind model for the Cyg X-1 system considered by Friend and Castor (1982). 105 references

  2. Topological properties of function spaces $C_k(X,2)$ over zero-dimensional metric spaces $X$

    OpenAIRE

    Gabriyelyan, S.

    2015-01-01

    Let $X$ be a zero-dimensional metric space and $X'$ its derived set. We prove the following assertions: (1) the space $C_k(X,2)$ is an Ascoli space iff $C_k(X,2)$ is $k_\\mathbb{R}$-space iff either $X$ is locally compact or $X$ is not locally compact but $X'$ is compact, (2) $C_k(X,2)$ is a $k$-space iff either $X$ is a topological sum of a Polish locally compact space and a discrete space or $X$ is not locally compact but $X'$ is compact, (3) $C_k(X,2)$ is a sequential space iff $X$ is a Pol...

  3. eXpression2Kinases (X2K) Web: linking expression signatures to upstream cell signaling networks.

    Science.gov (United States)

    Clarke, Daniel J B; Kuleshov, Maxim V; Schilder, Brian M; Torre, Denis; Duffy, Mary E; Keenan, Alexandra B; Lachmann, Alexander; Feldmann, Axel S; Gundersen, Gregory W; Silverstein, Moshe C; Wang, Zichen; Ma'ayan, Avi

    2018-05-25

    While gene expression data at the mRNA level can be globally and accurately measured, profiling the activity of cell signaling pathways is currently much more difficult. eXpression2Kinases (X2K) computationally predicts involvement of upstream cell signaling pathways, given a signature of differentially expressed genes. X2K first computes enrichment for transcription factors likely to regulate the expression of the differentially expressed genes. The next step of X2K connects these enriched transcription factors through known protein-protein interactions (PPIs) to construct a subnetwork. The final step performs kinase enrichment analysis on the members of the subnetwork. X2K Web is a new implementation of the original eXpression2Kinases algorithm with important enhancements. X2K Web includes many new transcription factor and kinase libraries, and PPI networks. For demonstration, thousands of gene expression signatures induced by kinase inhibitors, applied to six breast cancer cell lines, are provided for fetching directly into X2K Web. The results are displayed as interactive downloadable vector graphic network images and bar graphs. Benchmarking various settings via random permutations enabled the identification of an optimal set of parameters to be used as the default settings in X2K Web. X2K Web is freely available from http://X2K.cloud.

  4. Water adsorption on O(2x2)/Ru(0001) from STM experiments andfirst-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Sanfelix, P.; Sanchez-Portal, D.; Mugarza, A.; Shimizu,T.K.; Salmeron, M.; Arnau, A.

    2007-10-15

    We present a combined theoretical and experimental study of water adsorption on Ru(0001) pre-covered with 0.25 monolayers (ML) of oxygen forming a (2 x 2) structure. Several structures were analyzed by means of Density Functional Theory calculations for which STM simulations were performed and compared with experimental data. Up to 0.25 monolayers the molecules bind to the exposed Ru atoms of the 2 x 2 unit cell via the lone pair orbitals. The molecular plane is almost parallel to the surface with its H atoms pointing towards the chemisorbed O atoms of the 2 x 2 unit cell forming hydrogen bonds. The existence of these additional hydrogen bonds increases the adsorption energy of the water molecule to approximately 616 meV, which is {approx}220 meV more stable than on the clean Ru(0001) surface with a similar configuration. The binding energy shows only a weak dependence on water coverage, with a shallow minimum for a row structure at 0.125 ML. This is consistent with the STM experiments that show a tendency of the molecules to form linear rows at intermediate coverage. Our calculations also suggest the possible formation of water dimers near 0.25 ML.

  5. Relationship between the 3x2 achievement goals and perceived competence in Physical Education students

    Directory of Open Access Journals (Sweden)

    Cristina Garcia-Romero

    2015-09-01

    Full Text Available Youth affiliation to physical activity and their active implication in sport throughout life, are two of the main objectives in Physical Education. In this research we examine the relationship between the achievement goals and the perceived competence in Physical Education since the recent theoretical framework of 3x2 achievement goals. The sample comprised 205 (113 boys and 92 girls, aged 12 and 18 years (M =14,02; SD = 1,70, all of them belonging to two Secondary School in the North of Spain. These students completed the 3x2 Achievement Goal Questionnaire (CML3x2-EF and the perceived competence subscale factor included in the Basic Psychological Needs in Exercise Scale (BPNES, also adapted to Physical Education. We performed descriptive analysis (M and DT, Cronbach alphas and linear regression analysis by stepwise. The results showed a positive correlation between the six goals of achievement and the perceived competence, being particularly high value of approach-task and approach-self. The three approach goals (approach-task, approach-self, approach-other significantly predicted the perceived competence (ß = 0,43; 0,18; 0,20, respectively.

  6. Learning

    Directory of Open Access Journals (Sweden)

    Mohsen Laabidi

    2014-01-01

    Full Text Available Nowadays learning technologies transformed educational systems with impressive progress of Information and Communication Technologies (ICT. Furthermore, when these technologies are available, affordable and accessible, they represent more than a transformation for people with disabilities. They represent real opportunities with access to an inclusive education and help to overcome the obstacles they met in classical educational systems. In this paper, we will cover basic concepts of e-accessibility, universal design and assistive technologies, with a special focus on accessible e-learning systems. Then, we will present recent research works conducted in our research Laboratory LaTICE toward the development of an accessible online learning environment for persons with disabilities from the design and specification step to the implementation. We will present, in particular, the accessible version “MoodleAcc+” of the well known e-learning platform Moodle as well as new elaborated generic models and a range of tools for authoring and evaluating accessible educational content.

  7. Map Showing Geologic Terranes of the Hailey 1°x2° Quadrangle and the western part of the Idaho Falls 1°x2° Quadrangle, south-central Idaho

    Data.gov (United States)

    Department of the Interior — The paper version of Map Showing Geologic Terranes of the Hailey 1°x2° Quadrangle and the western part of the Idaho Falls 1°x2° Quadrangle, south-central Idaho was...

  8. An integrated neuro-robotic interface for stroke rehabilitation using the NASA X1 powered lower limb exoskeleton.

    Science.gov (United States)

    He, Yongtian; Nathan, Kevin; Venkatakrishnan, Anusha; Rovekamp, Roger; Beck, Christopher; Ozdemir, Recep; Francisco, Gerard E; Contreras-Vidal, Jose L

    2014-01-01

    Stroke remains a leading cause of disability, limiting independent ambulation in survivors, and consequently affecting quality of life (QOL). Recent technological advances in neural interfacing with robotic rehabilitation devices are promising in the context of gait rehabilitation. Here, the X1, NASA's powered robotic lower limb exoskeleton, is introduced as a potential diagnostic, assistive, and therapeutic tool for stroke rehabilitation. Additionally, the feasibility of decoding lower limb joint kinematics and kinetics during walking with the X1 from scalp electroencephalographic (EEG) signals--the first step towards the development of a brain-machine interface (BMI) system to the X1 exoskeleton--is demonstrated.

  9. Validation of X1 motorcycle model in industrial plant layout by using WITNESSTM simulation software

    Science.gov (United States)

    Hamzas, M. F. M. A.; Bareduan, S. A.; Zakaria, M. Z.; Tan, W. J.; Zairi, S.

    2017-09-01

    This paper demonstrates a case study on simulation, modelling and analysis for X1 Motorcycles Model. In this research, a motorcycle assembly plant has been selected as a main place of research study. Simulation techniques by using Witness software were applied to evaluate the performance of the existing manufacturing system. The main objective is to validate the data and find out the significant impact on the overall performance of the system for future improvement. The process of validation starts when the layout of the assembly line was identified. All components are evaluated to validate whether the data is significance for future improvement. Machine and labor statistics are among the parameters that were evaluated for process improvement. Average total cycle time for given workstations is used as criterion for comparison of possible variants. From the simulation process, the data used are appropriate and meet the criteria for two-sided assembly line problems.

  10. Ultraviolet, X-ray, and infrared observations of HDE 226868 equals Cygnus X-1

    Science.gov (United States)

    Treves, A.; Chiappetti, L.; Tanzi, E. G.; Tarenghi, M.; Gursky, H.; Dupree, A. K.; Hartmann, L. W.; Raymond, J.; Davis, R. J.; Black, J.

    1980-01-01

    During April, May, and July of 1978, HDE 226868, the optical counterpart of Cygnus X-1, was repeatedly observed in the ultraviolet with the IUE satellite. Some X-ray and infrared observations have been made during the same period. The general shape of the spectrum is that expected from a late O supergiant. Strong absorption features are apparent in the ultraviolet, some of which have been identified. The equivalent widths of the most prominent lines appear to be modulated with the orbital phase. This modulation is discussed in terms of the ionization contours calculated by Hatchett and McCray, for a binary X-ray source in the stellar wind of the companion.

  11. The smooth cyclotron line in her x-1 as seen with nuclear spectroscopic telescope array

    DEFF Research Database (Denmark)

    Fuerst, Felix; Grefenstette, Brian W.; Staubert, Ruediger

    2013-01-01

    , and a CRSF. We find that the CRSF has a very smooth and symmetric shape, in all observations and at all pulse-phases. We compare the residuals of a line with a Gaussian optical depth profile to a Lorentzian optical depth profile and find no significant differences, strongly constraining the very smooth shape....... We observed Her X-1 three times, coordinated with Suzaku, during one of the high flux intervals of its 35d super-orbital period. This paper focuses on the shape and evolution of the hard X-ray spectrum. The broad-band spectra can be fitted with a powerlaw with a high-energy cutoff, an iron line...... of the line. Even though the line energy changes dramatically with pulse phase, we find that its smooth shape does not. Additionally, our data show that the continuum is only changing marginally between the three observations. These changes can be explained with varying amounts of Thomson scattering...

  12. The smooth cyclotron line in Her X-1 as seen with NuSTAR

    DEFF Research Database (Denmark)

    Fuerst, Felix; Grefenstette, Brian W.; Staubert, Ruediger

    2013-01-01

    , and a CRSF. We find that the CRSF has a very smooth and symmetric shape, in all observations and at all pulse-phases. We compare the residuals of a line with a Gaussian optical depth profile to a Lorentzian optical depth profile and find no significant differences, strongly constraining the very smooth shape....... We observed Her X-1 three times, coordinated with Suzaku, during one of the high flux intervals of its 35d super-orbital period. This paper focuses on the shape and evolution of the hard X-ray spectrum. The broad-band spectra can be fitted with a powerlaw with a high-energy cutoff, an iron line...... of the line. Even though the line energy changes dramatically with pulse phase, we find that its smooth shape does not. Additionally, our data show that the continuum is only changing marginally between the three observations. These changes can be explained with varying amounts of Thomson scattering...

  13. Adsorption Mechanisms of NH3 on Chlorinated Si(100)-2 x 1 Surface

    International Nuclear Information System (INIS)

    Lee, Hee Soon; Choi, Cheol Ho

    2012-01-01

    The potential energy surfaces of ammonia molecule adsorptions on the symmetrically chlorinated Si(100)- 2 x 1 surface were explored with SIMOMM:MP2/6-31G(d). It was found that the initial nucleophilic attack by ammonia nitrogen to the surface Si forms a S N 2 type transition state, which eventually leads to an HCl molecular desorption. The second ammonia molecule adsorption requires much less reaction barrier, which can be rationalized by the surface cooperative effect. In general, it was shown that the surface Si-Cl bonds can be easily subjected to the substitution reactions by ammonia molecules yielding symmetric surface Si-NH 2 bonds, which can be a good initial template for subsequent surface chemical modifications. The ammonia adsorptions are in general more facile than the corresponding water adsorption, since ammonia is better nucleophile

  14. Mass-reduced quantum numbers: application to the isotopic lithium hydrides (X1B+)

    International Nuclear Information System (INIS)

    Li, K.C.; Stwalley, W.C.

    1977-01-01

    The massed-reduced quantum number (MRQN) method of combining isotopic data is applied to the lithium hydride X 1 Σ + ground state. The ΔG(eta) = μ/sup 1 / 2 / ΔG(v), B(eta) = μB(v) and D(eta) = μ 2 D(v) isotopically-combined functions are obtained. An isotopically-combined Rydberg-Klein Rees (ICRKR) potential is constructed using the G(eta) and B(eta) functions. Evidence for breakdown of the Born-Oppenheimer approximation is presented and examined. The Dunham, Simons-Parr-Finlan, and Thakkar methods of potential expansion are also applied to lithium hydride and compared to the RKR Potential

  15. RAPID PENUMBRA AND LORENTZ FORCE CHANGES IN AN X1.0 SOLAR FLARE

    International Nuclear Information System (INIS)

    Xu, Zhe; Jiang, Yunchun; Yang, Jiayang; Yang, Bo; Bi, Yi

    2016-01-01

    We present observations of the violent changes in photospheric magnetic structures associated with an X1.1 flare, which occurred in a compact δ-configuration region in the following part of AR 11890 on 2013 November 8. In both central and peripheral penumbra regions of the small δ sunspot, these changes took place abruptly and permanently in the reverse direction during the flare: the inner/outer penumbra darkened/disappeared, where the magnetic fields became more horizontal/vertical. Particularly, the Lorentz force (LF) changes in the central/peripheral region had a downward/upward and inward direction, meaning that the local pressure from the upper atmosphere was enhanced/released. It indicates that the LF changes might be responsible for the penumbra changes. These observations can be well explained as the photospheric response to the coronal field reconstruction within the framework of the magnetic implosion theory and the back reaction model of flares

  16. Three-color photometry of HDE 226868: The optical counterpart of cygnus X-1

    International Nuclear Information System (INIS)

    Lester, D.F.; Nolt, I.G.; Stearns, S.A.; Straton, P.; Radostitz, J.V.

    1976-01-01

    The results of UBV photoelectric observations of HDE 226868 (Cyg X-1) obtained on fifty nights during 1974 are presented. These observations show a light curve with the following characteristics: two unequal light maxima and minima during the 5/sup d/.6 orbital period which exhibit a peak-to-peak magnitude change of approx.0.07 mag in all colors;a small phase-dependent color variation which results in a reddening in both color indices of approx.0.003 mag at times of light minima; erratic light variability on a general time scale of days with an amplitude of +- 0.01 to 0.02 mag and no apparent color dependence

  17. Atomistic Frictional Properties of the C(1002x1-H Surface

    Directory of Open Access Journals (Sweden)

    Paul M. Jones

    2013-01-01

    Full Text Available Density functional theory- (DFT- based ab initio calculations were used to investigate the surface-to-surface interaction and frictional behavior of two hydrogenated C(100 dimer surfaces. A monolayer of hydrogen atoms was applied to the fully relaxed C(1002x1 surface having rows of C=C dimers with a bond length of 1.39 Å. The obtained C(1002x1-H surfaces (C–H bond length 1.15 Å were placed in a large vacuum space and translated toward each other. A cohesive state at a surface separation of 4.32 Å that is stabilized by approximately 0.42 eV was observed. An increase in the charge separation in the surface dimer was calculated at this separation having a 0.04 e transfer from the hydrogen atom to the carbon atom. The Mayer bond orders were calculated for the C–C and C–H bonds and were found to be 0.962 and 0.947, respectively. σ C–H bonds did not change substantially from the fully separated state. A significant decrease in the electron density difference between the hydrogen atoms on opposite surfaces was seen and assigned to the effects of Pauli repulsion. The surfaces were translated relative to each other in the (100 plane, and the friction force was obtained as a function of slab spacing, which yielded a 0.157 coefficient of friction.

  18. Short term variation of Cyg X-1 in the hard x-ray region

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Kosei [Tokyo Univ. (Japan). Inst. of Space and Aeronautical Science

    1978-08-01

    Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole.

  19. The smooth cyclotron line in Her X-1 as seen with nuclear spectroscopic telescope array

    Energy Technology Data Exchange (ETDEWEB)

    Fürst, Felix; Grefenstette, Brian W.; Bellm, Eric C.; Harrison, Fiona; Madsen, Kristin K.; Walton, Dominic J. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Staubert, Rüdiger; Klochkov, Dmitry [Institut für Astronomie und Astrophysik, Universität Tübingen (IAAT), D-72076 Tübingen (Germany); Tomsick, John A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Bachetti, Matteo; Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, F-31028 Toulouse (France); Chenevez, Jerome; Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Pottschmidt, Katja [CRESST, UMBC, and NASA GSFC, Code 661, Greenbelt, MD 20771 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Wilms, Jörn [Dr. Karl-Remeis-Sternwarte and ECAP, Sternwartstr. 7, D-96049 Bamberg (Germany); William Zhang [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-12-10

    Her X-1, one of the brightest and best studied X-ray binaries, shows a cyclotron resonant scattering feature (CRSF) near 37 keV. This makes it an ideal target for a detailed study with the Nuclear Spectroscopic Telescope Array (NuSTAR), taking advantage of its excellent hard X-ray spectral resolution. We observed Her X-1 three times, coordinated with Suzaku, during one of the high flux intervals of its 35 day superorbital period. This paper focuses on the shape and evolution of the hard X-ray spectrum. The broadband spectra can be fitted with a power law with a high-energy cutoff, an iron line, and a CRSF. We find that the CRSF has a very smooth and symmetric shape in all observations and at all pulse phases. We compare the residuals of a line with a Gaussian optical-depth profile to a Lorentzian optical-depth profile and find no significant differences, strongly constraining the very smooth shape of the line. Even though the line energy changes dramatically with pulse phase, we find that its smooth shape does not. Additionally, our data show that the continuum only changes marginally between the three observations. These changes can be explained with varying amounts of Thomson scattering in the hot corona of the accretion disk. The average, luminosity-corrected CRSF energy is lower than in past observations and follows a secular decline. The excellent data quality of NuSTAR provides the best constraint on the CRSF energy to date.

  20. Comparison of Knee and Ankle Dynamometry between NASA's X1 Exoskeleton and Biodex System 4

    Science.gov (United States)

    English, K. L.; Newby, N. J.; Hackney, K. J.; DeWitt, J. K.; Beck, C. E.; Rovekamp, R. N.; Rea, R. L.; Ploutz-Snyder, L. L.

    2014-01-01

    Pre- and post-flight dynamometry is performed on International Space Station crewmembers to characterize microgravity-induced strength changes. Strength is not assessed in flight due to hardware limitations and there is poor understanding of the time course of in-flight changes. PURPOSE: To assess the reliability of a prototype dynamometer, the X1 Exoskeleton (EXO) and its agreement with a Biodex System 4 (BIO). METHODS: Eight subjects (4 M/4 F) completed 2 counterbalanced testing sessions of knee extension/flexion (KE/KF), 1 with BIO and 1 with EXO, with repeated measures within each session in normal gravity. Test-retest reliability (test 1 and 2) and device agreement (BIO vs. EXO) were evaluated. Later, to assess device agreement for ankle plantarflexion (PF), 10 subjects (4 M/6 F) completed 3 test conditions (BIO, EXO, and BIOEXO); BIOEXO was a hybrid condition comprised of the Biodex dynamometer motor and the X1 footplate and ankle frame. Ankle comparisons were: BIO vs. BIOEXO (footplate differences), BIOEXO vs. EXO (motor differences), and BIO vs. EXO (all differences). Reliability for KE/KF was determined by intraclass correlation (ICC). Device agreement was assessed with: 1) repeated measures ANOVA, 2) a measure of concordance (rho), and 3) average difference. RESULTS: ICCs for KE/KF were 0.99 for BIO and 0.96 to 0.99 for EXO. Agreement was high for KE (concordance: 0.86 to 0.95; average differences: -7 to +9 Nm) and low to moderate for KF (concordance: 0.64 to 0.78; average differences: -4 to -29 Nm, Pexoskeleton to perform portable dynamometry for large muscle groups of the lower body.

  1. Short term variation of Cyg X-1 in the hard x-ray region

    International Nuclear Information System (INIS)

    Doi, Kosei

    1978-01-01

    Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole. (Wakatsuki, Y.)

  2. A detection of HER-X 1 at PeV energies, with anomalous muon number

    International Nuclear Information System (INIS)

    Nagle, D.E.

    1990-01-01

    The CYGNUS collaboration is operating a ground-based array of scintillation detectors to detect-extensive air showers. This paper reports that the objective is to detect compact sources of Ultra High Energy (PeV) gamma radiation. At the present time the array consists of 106 scintillation detectors of ∼10 4 m 2 . It is supplemented by a tracking detector of muons, shielded by about 6 feet of steel: its purpose is to compare the number of muons from purported gamma-ray primaries with the number from ordinary cosmic-ray primaries. Last year we reported 2 an unusual episode of emission from the direction of the binary source Hercules X-1, with the following features: on 24 July 1986 an excess event rate in the direction of Her X-1 was detected. The pulsar period observed, namely T = (1.23568s ± 0.0003s), is blue-shifted by about 0.16% from the contemporary X-ray period. The average number of muons detected in these events is not less than the number for ordinary cosmic ray events as seen in our detector. At Tev energies, two stations operating air-Cherenkov telescopes, namely Mt. Hopkins and Haleakala, had reported periods nearly identical to the authors': Lamb et al., T = (1.23579 ± 0.0002), and Resvanis et al., T = (1.23593 ± 0.0002). Recently the Haleakala group have added another detection, on May 23, 1987: T = 23598s. Another report comes from the Tata Institute, Bombay, which operates the air-shower array at Ooty

  3. Heating, Ventilation, Air Conditioning, and Refrigeration (HVAC/R), AFSC 3E1X1. OSSN 2368

    National Research Council Canada - National Science Library

    1999-01-01

    Survey Coverage: The Heating, Ventilation, Air Conditioning, and Refrigeration (HVAC/R) career ladder, AFSC 3E1X1, was surveyed to gather data needed to guide the development and evaluation of training...

  4. Changes in the Long-Term Intensity Variations in Cygnus X-2 and LMC X-3

    Science.gov (United States)

    Paul, B.; Kitamoto, S.; Makino, F.

    2000-01-01

    We report the detection of changes in the long-term intensity variations in two X-ray binaries, Cyg X-2 and LMC X-3. In this work, we have used the long-term light curves obtained with the All-Sky Monitors (ASMs) of the Rossi X-Ray Timing Explorer (RXTE), Ginga, Ariel 5, and Vela 5B and the scanning modulation collimator of HEAO 1. It is found that in the light curves of both the sources, obtained with these instruments at various times over the last 30 years, more than one periodic or quasi-periodic component is always present. The multiple prominent peaks in the periodograms have frequencies unrelated to each other. In Cyg X-2, RXTE-ASM data show strong peaks at 40.4 and 68.8 days, and Ginga-ASM data show strong peaks at 53.7 and 61.3 days. Multiple peaks are also observed in LMC X-3. The various strong peaks in the periodograms of LMC X-3 appear at 104, 169, and 216 days (observed with RXTE-ASM) and 105, 214, and 328 days (observed with Ginga-ASM). The present results, when compared with the earlier observations of periodicities in these two systems, demonstrate the absence of any stable long period. The 78 day periodicity detected earlier in Cyg X-2 was probably due to the short time base in the RXTE data that were used, and the periodicity of 198 days in LMC X-3 was due to a relatively short duration of observation with HEAO 1.

  5. Understanding students' motivation in project work: a 2 x 2 achievement goal approach.

    Science.gov (United States)

    Liu, Woon Chia; Wang, C K John; Tan, Oon Seng; Ee, Jessie; Koh, Caroline

    2009-03-01

    The project work (PW) initiative was launched in 2000 by the Ministry of Education, Singapore, to encourage application of knowledge across disciplines, and to develop thinking, communication, collaboration, and metacognitive skills. Although PW has been introduced for a few years, few studies have examined the motivation of students in PW, especially with the use of the recently proposed 2 x 2 achievement goal framework. To use a cluster analytic approach to identify students' achievement goal profiles at an intra-individual level, and to examine their links to various psychological characteristics and perceived outcomes in PW. Participants were 491 Secondary 2 students (mean age = 13.78, SD = 0.77) from two government coeducational schools. Cluster analysis was performed to identify distinct subgroups of students with similar achievement goal profiles. One-way MANOVAs, followed by post hoc Tukey HSD tests for pairwise comparisons were used to determine whether there was any significant difference amongst clusters in terms of the psychological characteristics and perceived outcomes in PW. Four distinct clusters of students were identified. The cluster with high achievement goals and the cluster with moderately high goals had the most positive psychological characteristics and perceived outcomes. In contrast, the cluster with very low scores for all four achievement goals had the most maladaptive profile. The study provides support for the 2 x 2 achievement goal framework, and demonstrates that multiple goals can operate simultaneously. However, it highlights the need for cross-cultural studies to look into the approach-avoidance dimension in the 2 x 2 achievement goal framework.

  6. 2 x 2 TeV mu(superscript +) mu (superscript) collider

    International Nuclear Information System (INIS)

    Mokhov, N.V.; Noble, R.J.

    1996-10-01

    The scenarios for high-luminosity 2 x 2 TeV and 250 x 250 GeV μ + μ - colliders are presented. Having a high physics potential, such a machine has specific physics and technical advantages and disadvantages when compared with an e + e - collider. Parameters for the candidate designs and the basic components - proton source, pion production and decay channel, cooling, acceleration and collider storage ring - are considered. Attention is paid to the areas mostly affecting the collider performance: targetry, energy spread, superconducting magnet survival, detector backgrounds, polarization, environmental issues. 13 refs., 9 figs., 4 tabs

  7. Magnetic properties of Zn(P/sub x/As/sub 1-x/)2 alloys

    International Nuclear Information System (INIS)

    Vitkina, T.Z.; Smolyarenko, E.M.; Trukhan, V.M.

    1987-01-01

    The authors study the magnetic properties of Zn(P/sub x/As/sub 1-x/) 2 alloys. The concentration-dependent magnetic susceptibility of these alloys is shown, as is the temperature dependence of the magnetic susceptibility in solid solutions of the alloys. The diamagnetic susceptibility associated with the valence electrons displays a marked change for a transition to the bound state inasmuch as the valence electrons constitute the chemical bonding in the crystal. The diamagnetic component of the susceptibility of the valence electrons is calculated according to the MO LCAO approximation on the assumption that there is sp 3 -hybridization of the atomic wave function

  8. The Co59 nuclear magnetic resonances in (Ysub(1-x)Gdsub(x))2Co17

    International Nuclear Information System (INIS)

    Nagai, Hiroyuki; Yoshie, Hiroshi; Unate, Takao; Tsujimura, Akira; Deportes, J.

    1976-01-01

    The nuclear magnetic resonances of Co 59 in (Ysub(1-x)Gdsub(x)) 2 Co 17 have been observed at 77 K as a function of x (0 2 Co 17 and Gd 2 Co 17 is at most 7 kOe in magnitude, which is comparable to that obtained in GdCo 5 . The sign of the obtained difference depends on the Co sites. The difference is qualitatively explained as the contribution of 4f electrons of Gd atoms to the hyperfine field. The temperature dependence of the resonance frequencies in Gd 2 Co 17 has also been measured. (auth.)

  9. Primes of the form x2+ny2 Fermat, class field theory, and complex multiplication

    CERN Document Server

    Cox, David A

    2014-01-01

    An exciting approach to the history and mathematics of number theory ". . . the author's style is totally lucid and very easy to read . . .the result is indeed a wonderful story." -Mathematical ReviewsWritten in a unique and accessible style for readers of varied mathematical backgrounds, the Second Edition of Primes of the Form p = x2+ ny2 details the history behind how Pierre de Fermat's work ultimately gave birth to quadratic reciprocity and the genus theory of quadratic forms. The book also illustrates how results of Euler and Gauss can be fully understood only in the context of class fi

  10. A neural network potential energy surface for the NaH2 system and dynamics studies on the H(2S) + NaH(X1Σ+) → Na(2S) + H2(X1Σg+) reaction.

    Science.gov (United States)

    Wang, Shufen; Yuan, Jiuchuang; Li, Huixing; Chen, Maodu

    2017-08-02

    In order to study the dynamics of the reaction H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), a new potential energy surface (PES) for the ground state of the NaH 2 system is constructed based on 35 730 ab initio energy points. Using basis sets of quadruple zeta quality, multireference configuration interaction calculations with Davidson correction were carried out to obtain the ab initio energy points. The neural network method is used to fit the PES, and the root mean square error is very small (0.00639 eV). The bond lengths, dissociation energies, zero-point energies and spectroscopic constants of H 2 (X 1 Σ g + ) and NaH(X 1 Σ + ) obtained on the new NaH 2 PES are in good agreement with the experiment data. On the new PES, the reactant coordinate-based time-dependent wave packet method is applied to study the reaction dynamics of H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), and the reaction probabilities, integral cross-sections (ICSs) and differential cross-sections (DCSs) are obtained. There is no threshold in the reaction due to the absence of an energy barrier on the minimum energy path. When the collision energy increases, the ICSs decrease from a high value at low collision energy. The DCS results show that the angular distribution of the product molecules tends to the forward direction. Compared with the LiH 2 system, the NaH 2 system has a larger mass and the PES has a larger well at the H-NaH configuration, which leads to a higher ICS value in the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction. Because the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction releases more energy, the product molecules can be excited to a higher vibrational state.

  11. Order-disorder phase transitions in the two-dimensional semiconducting transition metal dichalcogenide alloys Mo1−xWxX2 (X = S, Se, and Te)

    KAUST Repository

    Gan, Liyong

    2014-10-21

    A combination of density functional theory, an empirical model, and Monte Carlo simulations is used to shed light on the evolution of the atomic distribution in the two-dimensional semiconducting transition metal dichalcogenide alloys Mo1−xWxX2 (X = S, Se, and Te) as a function of the W concentration and temperature. Both random and ordered phases are discovered and the origin of the phase transitions is clarified. While the empirical model predicts at x = 1/3 and 2/3 ordered alloys, Monte Carlo simulations suggest that they only exist at low temperature due to a small energetic preference of Mo-X-W over Mo-X-Mo and W-X-W interactions, explaining the experimental observation of random alloy Mo1−xWxS2. Negative formation energies point to a high miscibility. Tunability of the band edges and band gaps by alteration of the W concentration gives rise to a broad range of applications.

  12. Order-disorder phase transitions in the two-dimensional semiconducting transition metal dichalcogenide alloys Mo1−xWxX2 (X = S, Se, and Te)

    KAUST Repository

    Gan, Liyong; Zhang, Qingyun; Zhao, Yu-Jun; Cheng, Yingchun; Schwingenschlö gl, Udo

    2014-01-01

    A combination of density functional theory, an empirical model, and Monte Carlo simulations is used to shed light on the evolution of the atomic distribution in the two-dimensional semiconducting transition metal dichalcogenide alloys Mo1−xWxX2 (X = S, Se, and Te) as a function of the W concentration and temperature. Both random and ordered phases are discovered and the origin of the phase transitions is clarified. While the empirical model predicts at x = 1/3 and 2/3 ordered alloys, Monte Carlo simulations suggest that they only exist at low temperature due to a small energetic preference of Mo-X-W over Mo-X-Mo and W-X-W interactions, explaining the experimental observation of random alloy Mo1−xWxS2. Negative formation energies point to a high miscibility. Tunability of the band edges and band gaps by alteration of the W concentration gives rise to a broad range of applications.

  13. THE CORRELATION BETWEEN STUDENTS’ LEARNING STYLES AND PARENTS’ ATTENTION WITH MEASURING EQUIPMENT ACHIEVEMENT OF THE TENTH GRADE STUDENTS OF AUTOMOTIVE ENGINEERING EXPERTISE PROGRAM OF STATE VOCATIONAL HIGH SCHOOL PIRI SLEMAN IN THE ACADEMIC YEAR 2013/2014

    Directory of Open Access Journals (Sweden)

    Moh. Sulhan Haidi

    2014-12-01

    Full Text Available This research is aimed at finding out (1 the correlation  between students’ learning styles and measuring equipment achievement of the tenth grade students of Automotive Engineering Expertise Program of State Vocational High School Piri Sleman in the academic year 2013/2014; (2 the correlation between parents’ attention with measuring equipment achievement of the tenth grade students of Automotive Engineering Expertise Program of State Vocational High School Piri Sleman in the academic year 2013/2014; (3 the correlation between students’ learning styles and parents’ attention with measuring equipment achievement of the tenth grade students of Automotive Engineering Expertise Program of State Vocational High School Piri Sleman in the Academic Year 2013/2014. The kind of this research is correlation study and categorized as ex post facto. The population of the research was 105 students while the sample was 82 students counted from Isaac and Michael formula. The technique of sampling used in this research was simple random sampling. The technique of the data collection was questionnaire and documentation. Item validity was computed from product moment correlation. Item reliability was calculated by using alpha formula. The technique of data analysis used in this study was partial correlation and doubled correlation analyses. Precondition testing analysis (normality, linearity, and multi co linearity testing, Based on the data analysis, the results were as follows: (1 there is a positive and significant correlation between students’ learning styles (X1 and measuring equipment achievement (Y; (2 there is a positive and significant correlation between parents’ attention (X2 with measuring equipment achievement (Y; (3 there is a positive and significant correlation between students’ learning styles (X1 and parents’ attention (X2 with measuring equipment achievement (Y.

  14. 1x2M steel performance in the BOR-60 steam generator

    International Nuclear Information System (INIS)

    Golovanov, V.N.; Shamardin, V.K.; Kondratiev, V.I.; Kryukov, F.N.; Chernobrovkin, Yu.V.; Bulanova, T.M.; Bai, V.F.

    The results from studies of 1x2M steel characteristics are presented. This steel was used as the material for the BOR-60 steam generator that had been in operation under the steam generating mode for 18,000 hs (35,000 hs in sodium). It was revealed that the pit corrosion depth on the water/steam side evaporative tube surfaces was about 0.25 μm and less and the total corrosion rate was less than 0.06 mm/y. The mechanical properties of the material were essentially similar both in the evaporator and superheater and met all the requirements imposed on. Based on the analysis of data on the decarbonizaton depth in sodium and on the corrosion damage in water and steam it was concluded that 1x2M steel can be successfully used as the steam generator material at the operating temperatures up to 470 deg. C and had sufficiently longer service-life as compared to 18,000 hs. (author)

  15. Structural and electronic properties of silicene on MgX2 (X = Cl, Br, and I)

    KAUST Repository

    Zhu, Jiajie

    2014-07-23

    Silicene is a monolayer of Si atoms in a two-dimensional honeycomb lattice, being expected to be compatible with current Si-based nanoelectronics. The behavior of silicene is strongly influenced by the substrate. In this context, its structural and electronic properties on MgX2 (X = Cl, Br, and I) have been investigated using first-principles calculations. Different locations of the Si atoms are found to be energetically degenerate because of the weak van der Waals interaction with the substrates. The Si buckling height is below 0.55 Å, which is close to the value of free-standing silicene (0.49 Å). Importantly, the Dirac cone of silicene is well preserved on MgX2 (located slightly above the Fermi level), and the band gaps induced by the substrate are less than 0.1 eV. Application of an external electric field and stacking can be used to increase the band gap. © 2014 American Chemical Society.

  16. 3x2 Classroom Goal Structures, Motivational Regulations, Self-Concept, and Affectivity in Secondary School.

    Science.gov (United States)

    Méndez-Giménez, Antonio; Cecchini-Estrada, José-Antonio; Fernández-Río, Javier; Prieto Saborit, José Antonio; Méndez-Alonso, David

    2017-09-20

    The main objective was to analyze relationships and predictive patterns between 3x2 classroom goal structures (CGS), and motivational regulations, dimensions of self-concept, and affectivity in the context of secondary education. A sample of 1,347 secondary school students (56.6% young men, 43.4% young women) from 10 different provinces of Spain agreed to participate (M age = 13.43, SD = 1.05). Hierarchical regression analyses indicated the self-approach CGS was the most adaptive within the spectrum of self-determination, followed by the task-approach CGS. The other-approach CGS had an ambivalent influence on motivation. Task-approach and self-approach CGS predicted academic self-concept (p approach CGS (negatively) predicted family self-concept (p approach and other-approach CGS's (p approach-oriented CGS's (p approach (positively) and self-approach (negatively) CGS (p < .001; p < .05, respectively; R 2 = .028). These results expand the 3x2 achievement goal framework to include environmental factors, and reiterate that teachers should focus on raising levels of self- and task-based goals for students in their classes.

  17. Dilemma solving by the coevolution of networks and strategy in a 2 x 2 game.

    Science.gov (United States)

    Tanimoto, Jun

    2007-08-01

    A 2 x 2 game model implemented by a coevolution mechanism of both networks and strategy, inspired by the work of Zimmermann and Eguiluz [Phys. Rev. E72, 056118 (2005)] is established. Network adaptation is the manner in which an existing link between two agents is destroyed and how a new one is established to replace it. The strategy is defined as whether an agent offers cooperation (C) or defection (D) . Both the networks and strategy are synchronously renovated in a simulation time step. A series of numerical experiments, considering various 2 x 2 game structures, reveals that the proposed coevolution mechanism can solve dilemmas in several game classes. The effect of solving a dilemma means mutual-cooperation reciprocity (R reciprocity), which is brought about by emerging several cooperative hub agents who have plenty of links. This effect can be primarily observed in game classes of the prisoner's dilemma and stag hunt. The coevolution mechanism, however, seems counterproductive for game classes of leader and hero, where the alternating reciprocity (ST reciprocity) is meaningful.

  18. Mechanical characterization tests of the X2-Gen fuel assembly and skeleton

    International Nuclear Information System (INIS)

    Kim, Hyung Kyu; Yoon, Kyung Ho; Lee, Kang Hee; Kim, Jae Yong; Lee, Young Ho; Kang, Heung Seok

    2011-01-01

    The KNF (KEPCO Nuclear Fuel) requested mechanical characterization tests of a fuel assembly and a skeleton of the X2-Gen fuel. The tests consisted of the lateral vibration and lateral/axial stiffness, lateral/axial impact and combined deflection tests carried out by using the FAMeCT (Fuel Assembly Mechanical Characterization Tester) in KAERI. The upper and lower core plate simulators were newly designed and manufactured because the fuel geometry of the X2-Gen was different from the KSNP type fuel assembly. In addition to this, the upper carriage was also revised with the LM guide system from the previous two guide rods system. Therefore, the axial and combined deflection tests were soundly executed. Each test was repeated twice to confirm the repeatability. The discrepancy from the repetition was small enough to be neglected. The mechanical characterization tests were accredited with the KOLAS (Korea Laboratory Accreditation Scheme) standard, and the certified test reports (lateral vibration, lateral/axial bending and lateral/axial impact) and the uncertified test report (combined deflection) were issued together with the current test result report

  19. Achievement goals, self-handicapping, and performance: a 2 x 2 achievement goal perspective.

    Science.gov (United States)

    Ntoumanis, Nikos; Thøgersen-Ntoumani, Cecilie; Smith, Alison L

    2009-11-01

    Elliot and colleagues (2006) examined the effects of experimentally induced achievement goals, proposed by the trichotomous model, on self-handicapping and performance in physical education. Our study replicated and extended the work of Elliot et al. by experimentally promoting all four goals proposed by the 2 x 2 model (Elliot & McGregor, 2001), measuring the participants' own situational achievement goals, using a relatively novel task, and testing the participants in a group setting. We used a randomized experimental design with four conditions that aimed to induce one of the four goals advanced by the 2 x 2 model. The participants (n = 138) were undergraduates who engaged in a dart-throwing task. The results pertaining to self-handicapping partly replicated Elliot and colleagues' findings by showing that experimentally promoted performance-avoidance goals resulted in less practice. In contrast, the promotion of mastery-avoidance goals did not result in less practice compared with either of the approach goals. Dart-throwing performance did not differ among the four goal conditions. Personal achievement goals did not moderate the effects of experimentally induced goals on self-handicapping and performance. The extent to which mastery-avoidance goals are maladaptive is discussed, as well as the interplay between personal and experimentally induced goals.

  20. Participation of the Abastumani Astrophysical Observatory in Different Programs for Coordinated Investigation of Cyg X-1

    Science.gov (United States)

    Kumsiashvili, M. I.; Kochiashvili, N. T.

    2000-10-01

    Broad-band photometric observations of the black hole candidate Cyg X-1 were carried out in 1975-1998 at the Abastumani Astrophysical Observatory in the framework of coordinated observations, at the varies observatories of the former Soviet Union. All data have been reduced to a homogeneous set.Comparison of the optical and X-ray data clearly shows the existence of several kinds of variability. Analysis of the prolonged photoelectric observations of V 1357 Cyg=Cyg X-1 confirmed long-period optical variation of this X-ray binary system with the period of 294 d revealed by Kemp et al. This periodicity is most strongly pronounced at the orbital period phase when the optical star is in front of the X-ray source. Variations of the mean level of Cyg X-1 and of the light curve form with the phase of the period 294 d agree well with the model of the precessing accretion disk which radiates in the optical range mainly by scattering and processing of the optical star radiation. The direction of the disc precession coincides with that of the orbital motion and it is hard to understand this fact in the models with the forced precession. The triple system model is less probable. There are also observations of this objects made in the Abastumani Observatory in 1982-1988 which are represented the Table and light curves. These observations have not discussed by coordinators. The observations taken in the course of the International campaign "The Optical Monitoring of the Unique Astrophysical Objects" were realized by the observatories located on the territories of Georgia, Russia, Uzbekistan and Ukraine in 1994-1998. They are united in a single set, taking into account the systemic differences between them. Number of usual observations is 2247 in 399 nights in U B V R bands. The observations were performed simultaneously in X-ray band in the energy range of 2-10 keV (ASM/RXTE), and 20-100 keV (BASTE/CGRO), and also with radio observations at the Mullard radio observatory. Our

  1. The Bacterial Effector HopX1 Targets JAZ Transcriptional Repressors to Activate Jasmonate Signaling and Promote Infection in Arabidopsis

    Science.gov (United States)

    Gimenez-Ibanez, Selena; Boter, Marta; Fernández-Barbero, Gemma; Chini, Andrea; Rathjen, John P.; Solano, Roberto

    2014-01-01

    Pathogenicity of Pseudomonas syringae is dependent on a type III secretion system, which secretes a suite of virulence effector proteins into the host cytoplasm, and the production of a number of toxins such as coronatine (COR), which is a mimic of the plant hormone jasmonate-isoleuce (JA-Ile). Inside the plant cell, effectors target host molecules to subvert the host cell physiology and disrupt defenses. However, despite the fact that elucidating effector action is essential to understanding bacterial pathogenesis, the molecular function and host targets of the vast majority of effectors remain largely unknown. Here, we found that effector HopX1 from Pseudomonas syringae pv. tabaci (Pta) 11528, a strain that does not produce COR, interacts with and promotes the degradation of JAZ proteins, a key family of JA-repressors. We show that hopX1 encodes a cysteine protease, activity that is required for degradation of JAZs by HopX1. HopX1 associates with JAZ proteins through its central ZIM domain and degradation occurs in a COI1-independent manner. Moreover, ectopic expression of HopX1 in Arabidopsis induces the expression of JA-dependent genes, represses salicylic acid (SA)-induced markers, and complements the growth of a COR-deficient P. syringae pv. tomato (Pto) DC3000 strain during natural bacterial infections. Furthermore, HopX1 promoted susceptibility when delivered by the natural type III secretion system, to a similar extent as the addition of COR, and this effect was dependent on its catalytic activity. Altogether, our results indicate that JAZ proteins are direct targets of bacterial effectors to promote activation of JA-induced defenses and susceptibility in Arabidopsis. HopX1 illustrates a paradigm of an alternative evolutionary solution to COR with similar physiological outcome. PMID:24558350

  2. Substoichiometric cobalt oxide monolayer on Ir(100)-(1 x 1)

    International Nuclear Information System (INIS)

    Gubo, M; Ebensperger, C; Meyer, W; Hammer, L; Heinz, K

    2009-01-01

    A substoichiometric monolayer of cobalt oxide has been prepared by deposition and oxidation of slightly less than one monolayer of cobalt on the unreconstructed surface of Ir(100). The ultrathin film was investigated by scanning tunnelling microscopy (STM) and quantitative low-energy electron diffraction (LEED). The cobalt species of the film reside in or near hollow positions of the substrate with, however, unoccupied sites (vacancies) in a 3 x 3 arrangement. In the so-formed 3 x 3 supercell the oxide's oxygen species are both threefold and fourfold coordinated to cobalt, forming pyramids with a triangular and square cobalt basis, respectively. These pyramids are the building blocks of the oxide. Due to the reduced coordination as compared to the sixfold one in the bulk of rock-salt-type CoO, the Co-O bond lengths are smaller than in the latter. For the threefold coordination they compare very well with the bond length in oxygen terminated CoO(111) films investigated recently. The substoichiometric 3 x 3 oxide monolayer phase transforms to a stoichiometric c(10 x 2)-periodic oxide monolayer under oxygen exposure, in which, however, cobalt and oxygen species are in (111) orientation and so form a CoO(111) layer.

  3. LONG-TERM EVOLUTION OF THE MAIN-ON STATES IN HERCULES X-1

    Energy Technology Data Exchange (ETDEWEB)

    Šimon, Vojtech, E-mail: simon@asu.cas.cz [Astronomical Institute, The Czech Academy of Sciences, 25165 Ondřejov (Czech Republic)

    2015-07-15

    Rossi X-ray Timing Explorer All-sky Monitor (RXTE ASM) observations and American Association of Variable Star Observers (AAVSO) optical data were used for a time-series analysis of the long-term activity of Her X-1. The problem of measuring the long-term evolution of the X-ray intensity in the light curve which consists only of separated intense spikes was addressed. For this purpose, the fluence of each Main-On state was determined. The fluences vary generally (not only in the transitions into/from anomalous low states (ALSs)) by tens of percent on timescales of at least several epochs of the cycle length of the superorbital cycle (but without any stable cycle) while irradiation of the donor producing the optical modulation remains considerably more stable. ALS1 and ALS2 are extensions of the tail in the statistical distribution of these fluences. In this interpretation, the variations of the fluences are caused by the changes of the structure of the inner disk region, which produces variable obscuration of the beams (emitting in the ASM band) at the neutron star. A small change of obscuration of these beams by the inner disk region suffices to change the fluences largely. However, the irradiation of the donor is changed significantly less because this inner disk region (which emits beyond the ASM band and acts as the occulting region of the beams) also irradiates the donor.

  4. The pure rotational spectrum of ZnS (X 1Σ +)

    Science.gov (United States)

    Zack, L. N.; Ziurys, L. M.

    2009-10-01

    The pure rotational spectrum of ZnS (X 1Σ +) has been measured using direct-absorption millimeter/sub-millimeter techniques in the frequency range 372-471 GHz. This study is the first spectroscopic investigation of this molecule. Spectra originating in four zinc isotopologues ( 64ZnS, 66ZnS, 68ZnS, and 67ZnS) were recorded in natural abundance in the ground vibrational state, and data from the v = 1 state were also measured for the two most abundant zinc species. Spectroscopic constants have been subsequently determined, and equilibrium parameters have been estimated. The equilibrium bond length was calculated to be re ˜ 2.0464 Å, which agrees well with theoretical predictions. In contrast, the dissociation energy of DE ˜ 3.12 eV calculated for ZnS, assuming a Morse potential, was significantly higher than past experimental and theoretical estimates, suggesting diabatic interaction with other potentials that lower the effective dissociation energy. Although ZnS is isovalent with ZnO, there appear to be subtle differences in bonding between the two species, as suggested by their respective force constants and bond length trends in the 3d series.

  5. Light curve and pulse profile of the x-ray pulsar Vela X-1

    International Nuclear Information System (INIS)

    Nagase, Fumiaki; Hayakawa, Satio; Makino, Fumiyoshi; Sato, Naohisa; Makishima, Kazuo.

    1983-01-01

    The following properties of the X-ray binary pulsar Vela X-1 are presented by reference to its observations in March 1980. The light curve shows a high state and a low state in the first and second halves of an orbital period, respectively, but they may rather be defined as a soft state and hard state, respectively, since the intensity above 9 keV does not appreciably change between these two states. The energy spectra in these states indicate the presence of circumstellar absorption. The pulse profiles at high (9-22 keV) and low (1-9 keV) energies are different, indicating the absorption by cold matter which is probably in the accretion column. The absorber which is responsible for the soft and hard states is attributed to the stellar wind whose flow pattern is consistent with that obtained from optical absorption spectra. The orbital period is obtained by a combined analysis of X-ray data since 1972. No appreciable change of the period gives a constraint on the dynamical behavior of the binary system. (author)

  6. Investigation of split-off dimers on the Si(001)2x1 surface

    International Nuclear Information System (INIS)

    Schofield, S.R.; O'Brien, J.L.; Curson, N.J.; Simmons, M.Y.; Clark, R.G.

    2002-01-01

    Full text: A detailed knowledge of the nature of crystalline defects on the Si(001)2x1 surface is becoming increasingly important as more research effort is dedicated to producing atomic-scale electronic devices. Here we present high-resolution scanning tunnelling microscopy (STM) images and ab initio pseudopotential calculations of an unusual defect of the silicon (001) surface called the split-off dimer. In high-resolution filled-state images, split-off dimers appear as a pair of protrusions, in contrast to the surrounding surface dimers that appear as 'bean-shaped' protrusions. We show that π-bonding does not exist between the atoms of the split-off dimer, but instead, the dimer atoms form π-bonds with two second layer atoms as part of a tetramer bonding arrangement. We discuss the strain associated with split-off dimer defects and describe how this strain significantly affects the bonding arrangements and local density of states around these defects

  7. American X-Vehicles: An Inventory X-1 to X-50 Centennial of Flight Edition

    Science.gov (United States)

    Jenkins, Dennis R.; Landis, Tony; Miller, Jay

    2003-01-01

    For a while, it seemed the series of experimental aircraft sponsored by the U. S. government had run its course. Between the late 1940s and the late 1970s, almost thirty designations had been allocated to aircraft meant to explore new flight regimes or untried technologies. Then, largely, it ended. But there was a resurgence in the mid- to late- 1990s, and as we enter the fourth year of the new millennia, the designations are up to x-50. Many have a misconception that X-vehicles have always explored the high-speed and high-altitude flight regimes - something popularized by Chuck Yeager in the original X-1 and the exploits of the twelve men that flew the X-15. Although these flight regimes have always been in the spotlight, many others have been explored by X-vehicles. The little Bensen X-25 never exceeded 85 mph, and others were limited to speeds of several hundred mph. There has been some criticism that the use of X designations has been corrupted somewhat by including what are essentially prototypes of future operational aircraft, especially the two JSF demonstrators. But this is not new-the X-11 and X-12 from the 1950s were going to be prototypes of the Atlas intercontinental ballistic missile, and the still-born Lockheed X-27 was always intended as a prototype of a production aircraft. So although this practice does not represent the best use of 'X' designations, it is not without precedent.

  8. All-fiber 7x1 signal combiner for incoherent laser beam combining

    Science.gov (United States)

    Noordegraaf, D.; Maack, M. D.; Skovgaard, P. M. W.; Johansen, J.; Becker, F.; Belke, S.; Blomqvist, M.; Laegsgaard, J.

    2011-02-01

    We demonstrate an all-fiber 7x1 signal combiner for incoherent laser beam combining. This is a potential key component for reaching several kW of stabile laser output power. The combiner couples the output from 7 single-mode (SM) fiber lasers into a single multi-mode (MM) fiber. The input signal fibers have a core diameter of 17 μm and the output MM fiber has a core diameter of 100 μm. In a tapered section light gradually leaks out of the SM fibers and is captured by a surrounding fluorine-doped cladding. The combiner is tested up to 2.5 kW of combined output power and only a minor increase in device temperature is observed. At an intermediate power level of 600 W a beam parameter product (BPP) of 2.22 mm x mrad is measured, corresponding to an M2 value of 6.5. These values are approaching the theoretical limit dictated by brightness conservation.

  9. Modelling hard and soft states of Cygnus X-1 with propagating mass accretion rate fluctuations

    Science.gov (United States)

    Rapisarda, S.; Ingram, A.; van der Klis, M.

    2017-12-01

    We present a timing analysis of three Rossi X-ray Timing Explorer observations of the black hole binary Cygnus X-1 with the propagating mass accretion rate fluctuations model PROPFLUC. The model simultaneously predicts power spectra, time lags and coherence of the variability as a function of energy. The observations cover the soft and hard states of the source, and the transition between the two. We find good agreement between model predictions and data in the hard and soft states. Our analysis suggests that in the soft state the fluctuations propagate in an optically thin hot flow extending up to large radii above and below a stable optically thick disc. In the hard state, our results are consistent with a truncated disc geometry, where the hot flow extends radially inside the inner radius of the disc. In the transition from soft to hard state, the characteristics of the rapid variability are too complex to be successfully described with PROPFLUC. The surface density profile of the hot flow predicted by our model and the lack of quasi-periodic oscillations in the soft and hard states suggest that the spin of the black hole is aligned with the inner accretion disc and therefore probably with the rotational axis of the binary system.

  10. RAPID SPECTRAL CHANGES OF CYGNUS X-1 IN THE LOW/HARD STATE WITH SUZAKU

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, S.; Makishima, K. [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198 (Japan); Negoro, H. [Department of Physics, College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Torii, S.; Noda, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mineshige, S. [Department of Astronomy, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan)

    2013-04-20

    Rapid spectral changes in the hard X-ray on a timescale down to {approx}0.1 s are studied by applying a ''shot analysis'' technique to the Suzaku observations of the black hole binary Cygnus X-1, performed on 2008 April 18 during the low/hard state. We successfully obtained the shot profiles, covering 10-200 keV with the Suzaku HXD-PIN and HXD-GSO detector. It is notable that the 100-200 keV shot profile is acquired for the first time owing to the HXD-GSO detector. The intensity changes in a time-symmetric way, though the hardness changes in a time-asymmetric way. When the shot-phase-resolved spectra are quantified with the Compton model, the Compton y-parameter and the electron temperature are found to decrease gradually through the rising phase of the shot, while the optical depth appears to increase. All the parameters return to their time-averaged values immediately within 0.1 s past the shot peak. We have not only confirmed this feature previously found in energies below {approx}60 keV, but also found that the spectral change is more prominent in energies above {approx}100 keV, implying the existence of some instant mechanism for direct entropy production. We discuss possible interpretations of the rapid spectral changes in the hard X-ray band.

  11. INITIATION PROCESSES FOR THE 2013 MAY 13 X1.7 LIMB FLARE

    International Nuclear Information System (INIS)

    Shen, Jinhua; Wang, Ya; Zhou, Tuanhui; Ji, Haisheng

    2017-01-01

    For the X1.7 class flare on 2013 May 13 (SOL2013-05-13T01:53), its initiation process was well observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory and the Extreme UltraViolet Imager (EUVI) on board STEREO-B . The initiation process incorporates the following phenomena: an X-ray precursor that started ∼9 minutes before flare onset, two hot magnetic loops (as seen with AIA hot channels) forming a sigmoidal core magnetic structure (as seen with the EUVI), a rapidly formed magnetic flux rope (MFR) that expands outward, and a flare loop that contracts inward. The two hot magnetic loops were activated after the occurrence of the X-ray precursor. After activation, magnetic reconnection occurred between the two hot magnetic loops (inside the sigmoid structure), which produced the expanding MFR and the contracting flare loop (CFL). The MFR and CFL can only be seen with AIA hot and cool channels, respectively. For this flare, the real initiation time can be regarded as being from the starting time of the precursor, and its impulsive phase started when the MFR began its fast expansion. In addition, the CFL and the growing postflare magnetic loops are different loop systems, and the CFL was the product of magnetic reconnection between sheared magnetic fields that also produced the MFR.

  12. INITIATION PROCESSES FOR THE 2013 MAY 13 X1.7 LIMB FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jinhua [Xinjiang Astronomical Observatory, CAS, 830011, Urumqi (China); Wang, Ya; Zhou, Tuanhui; Ji, Haisheng, E-mail: jihs@pmo.ac.cn [Purple Mountain Observatory, CAS, Nanjing, 210008 (China)

    2017-01-20

    For the X1.7 class flare on 2013 May 13 (SOL2013-05-13T01:53), its initiation process was well observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory and the Extreme UltraViolet Imager (EUVI) on board STEREO-B . The initiation process incorporates the following phenomena: an X-ray precursor that started ∼9 minutes before flare onset, two hot magnetic loops (as seen with AIA hot channels) forming a sigmoidal core magnetic structure (as seen with the EUVI), a rapidly formed magnetic flux rope (MFR) that expands outward, and a flare loop that contracts inward. The two hot magnetic loops were activated after the occurrence of the X-ray precursor. After activation, magnetic reconnection occurred between the two hot magnetic loops (inside the sigmoid structure), which produced the expanding MFR and the contracting flare loop (CFL). The MFR and CFL can only be seen with AIA hot and cool channels, respectively. For this flare, the real initiation time can be regarded as being from the starting time of the precursor, and its impulsive phase started when the MFR began its fast expansion. In addition, the CFL and the growing postflare magnetic loops are different loop systems, and the CFL was the product of magnetic reconnection between sheared magnetic fields that also produced the MFR.

  13. Predicting precompetitive state anxiety: using the 2 x 2 achievement goal framework.

    Science.gov (United States)

    Li, Chiung-Huang

    2013-10-01

    The goal was to examine the predictiveness of achievement goals for self-confidence, cognitive anxiety, and somatic anxiety using a prospective design. 160 high school athletes completed the 2 x 2 Achievement Goals Questionnaire for Sport after daily practice and the Revised Competitive State Anxiety Inventory-2 before an official competition. Using hierarchical regression analyses, mastery-approach goals were found as positive predictors of self-confidence and negative predictors of cognitive and somatic anxiety. In contrast, performance- and mastery-avoidance goals positively predicted cognitive and somatic anxiety. Also, performance-avoidance goals negatively predicted self-confidence. Generally, athletes who pursued task mastery and improvement of competence were less physically and cognitively anxious and more self-confident. However, athletes felt tense, worried, and had lower confidence when they endorsed avoidance forms of achievement goals.

  14. On the Magnetic Field of the Ultraluminous X-Ray Pulsar M82 X-2

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kun; Li, Xiang-Dong, E-mail: lixd@nju.edu.cn [Department of Astronomy, Nanjing University, Nanjing 210023 (China)

    2017-04-01

    The discovery of the ultraluminous X-ray pulsar M82 X-2 has stimulated lively discussion on the nature of the accreting neutron star. In most of the previous studies the magnetic field of the neutron star was derived from the observed spin-up/down rates based on the standard thin, magnetized accretion disk model. However, under super-Eddington accretion the inner part of the accretion disk becomes geometrically thick. In this work we consider both radiation feedback from the neutron star and the sub-Keplerian rotation in a thick disk and calculate the magnetic moment–mass accretion rate relations for the measured rates of spin change. We find that the derived neutron star's dipole magnetic field depends on the maximum accretion rate adopted, but is likely ≲10{sup 13} G. The predicted accretion rate change can be used to test the proposed models by comparison with observations.

  15. PENGARUH SELF REGULATED LEARNING LINGKUNGAN KELUARGA, DAN DISIPLIN BELAJAR TERHADAP HASIL BELAJAR MATA PELAJARAN PENGANTAR AKUNTANSI KELAS X AKUNTANSI SMK PL TARCISIUS SEMARANG TAHUN AJARAN 2014/2015

    Directory of Open Access Journals (Sweden)

    Hendra Anto Permana

    2015-11-01

    Full Text Available Hasil belajar pengantar akuntansi dipengaruhi oleh berbagai faktor baik faktor internal maupun faktor eksternal. Permasalahan yang dikaji dalam penelitian ini adalah pengaruh self regulated learning, lingkungan keluarga, dan disiplin belajar terhadap hasil belajar siswa pada mata pelajaran pengantar akuntansi kelas X Akuntansi SMK PL Tarcisius Semarang secara simultan maupun parsial. Tujuan dalam penelitian ini adalah untuk mendeskripsikan pengaruh self regulated learning, lingkungan keluarga, dan disiplin belajar terhadap hasil belajar siswa pada mata pelajaran pengantar akuntansi kelas X akuntansi SMK PL tarcisius semarang secara simultan maupun parsial. Populasi penelitian ini adalah siswa kelas X Akuntansi SMK PL Tarcisius Semarang sebanyak 148 siswa, dan sampel sebanyak 108 siswa yang dilihat dari rumus Slovin dan teknik pengambilan sampel dengan proportional random sampling. Variabel dalam penelitian ini meliputi variabel terikat yaitu hasil belajar pengantar akuntansi (Y, variabel bebas yaitu lingkungan sekolah (X1, lingkungan keluarga (X2 dan disipin belajar (X3. Pengumpulan data dengan metode dokumentasi dan angket. Pengolahan data dengan analisis deskriptif dan analisis statistik inferensial. Secara simultan ada pengaruh positif dan signifikan self regulated learning, lingkungan keluarga, dan disiplin belajar terhadap hasil belajar siswa pada mata pelajaran pengantar akuntansi. Secara partial ada pengaruh positif dan signifikan self regulated learning terhadap hasil belajar pengantar akuntansi, ada pengaruh positif dan signifikan lingkungan keluarga terhadap hasil belajar pengantar akuntansi, ada pengaruh positif dan signifikan disiplin belajar terhadap hasil belajar pengantar akuntansi. Introduction of learning outcomes accounting is influenced by various factors both internal factors and external factors. Issues examined in this study was the influence of self-regulated learning, family environment, and the discipline of learning to

  16. Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

    Science.gov (United States)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

  17. 2 x 2 achievement goals profilEs in chilean CompetiTIve and recreational athletes: a first look

    OpenAIRE

    Marc R. Lochbaum; Javan Jean-Noel; Zişan Kazak Çetinkalp; Felipe Andrés Vallejo-Reyes; Jose Mena-Campbell

    2016-01-01

    Purpose: was to examine the 2 x 2 achievement goal profiles of Chilean young adults regularly participating in competitive and recreational sport. Materials: participants were 108 female and 132 males who were recruited from the Valparaiso and Viña del Mar areas of Chile. Participants completed a valid and reliable measure of the 2 x 2 achievement goals referenced to sport participation. Results: indicated that the entire sample significantly ( p - .05) and very meaningfully (Hedges’ g range ...

  18. Magnetic properties of CE(Fe sub(1-x) Al sub(x))2 for x<=0.20

    International Nuclear Information System (INIS)

    Franceschini, D.F.; Cunha, S.F. da.

    1985-01-01

    Magnetization measurements of the system Ce(Fe sub(1-x) Al sub(x)) 2 for x 2 has not a simple dilution effect. Together with a accentuated decrease in the iron mean magnetic moment and in Curie temperatures was observed, above a certain concentration, a transition from ferromagnetism to a canted spin phase upon decreasing temperature. For the higher concentration range the system exhibits magnetic freezing effects. A preliminary magnetic phase diagram was proposed. (Author) [pt

  19. Search for gravitational redshifted absorption lines in LMXB Serpens X-1

    Science.gov (United States)

    Yoneda, Hiroki; Done, Chris; Paerels, Frits; Takahashi, Tadayuki; Watanabe, Shin

    2018-04-01

    The equation of state for ultradense matter can be tested from observations of the ratio of mass to radius of neutron stars. This could be measured precisely from the redshift of a narrow line produced on the surface. X-rays bursts have been intensively searched for such features, but so far without detection. Here instead we search for redshifted lines in the persistent emission, where the accretion flow dominates over the surface emission. We discuss the requirements for narrow lines to be produced, and show that narrow absorption lines from highly ionized iron can potentially be observable in accreting low-mass X-ray binaries (LMXBs; low B field) that have either low spin or low inclination so that Doppler broadening is small. This selects Serpens X-1 as the only potential candidate persistent LMXB due to its low inclination. Including surface models in the broad-band accretion flow model predicts that the absorption line from He-like iron at 6.7 keV should be redshifted to ˜5.1-5.7 keV (10-15 km for 1.4 M⊙) and have an equivalent width of 0.8-8 eV for surface temperatures of 7-10 × 106 K. We use the high-resolution Chandra grating data to give a firm upper limit of 2-3 eV for an absorption line at ˜5 keV. We discuss possible reasons for this lack of detection (the surface temperature and the geometry of the boundary layer etc.). Future instruments with better sensitivity are required in order to explore the existence of such features.

  20. On the origin of a sunquake during the 2014 March 29 X1 flare

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Philip G. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Kleint, Lucia [Institute of 4D Technologies, University of Applied Sciences and Arts Northwestern Switzerland, 5210 Windisch (Switzerland); Donea, Alina [Center for Astrophysics, School of Mathematical Science, Monash University, Victoria 3800 (Australia); Dalda, Alberto Sainz [Stanford-Lockheed Institute for Space Research, Stanford University, HEPL, 466 Via Ortega, Stanford, CA 94305 (United States); Fletcher, Lyndsay, E-mail: judge@ucar.edu, E-mail: lucia.kleint@fhnw.ch, E-mail: alina.donea@monash.edu, E-mail: asdalda@stanford.edu, E-mail: lyndsay.fletcher@glasgow.ac.uk [SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2014-12-01

    Helioseismic data from the Helioseismic Magnetic Imager instrument have revealed a sunquake associated with the X1 flare SOL2014-03-29T17:48 in active region NOAA 12017. We try to discover if acoustic-like impulses or actions of the Lorentz force caused the sunquake. We analyze spectropolarimetric data obtained with the Facility Infrared Spectrometer (FIRS) at the Dunn Solar Telescope (DST). Fortunately, the FIRS slit crossed the flare kernel close to the acoustic source during the impulsive phase. The infrared FIRS data remain unsaturated throughout the flare. Stokes profiles of lines of Si I 1082.7 nm and He I 1083.0 nm are analyzed. At the flare footpoint, the Si I 1082.7 nm core intensity increases by a factor of several, and the IR continuum increases by 4% ± 1%. Remarkably, the Si I core resembles the classical Ca II K line's self-reversed profile. With nLTE radiative models of H, C, Si, and Fe, these properties set the penetration depth of flare heating to 100 ± 100 km (i.e., photospheric layers). Estimates of the non-magnetic energy flux are at least a factor of two less than the sunquake energy flux. Milne-Eddington inversions of the Si I line show that the local magnetic energy changes are also too small to drive the acoustic pulse. Our work raises several questions. Have we missed the signature of downward energy propagation? Is it intermittent in time and/or non-local? Does the 1-2 s photospheric radiative damping time discount compressive modes?.

  1. AstroSat /LAXPC Observation of Cygnus X-1 in the Hard State

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Ranjeev; Pahari, Mayukh [Inter-University Centre for Astronomy and Astrophysics, Pune 411007 (India); Yadav, J S; Chauhan, Jai Verdhan; Antia, H M; Chitnis, V R; Dedhia, Dhiraj; Katoch, Tilak; Madhwani, P.; Shah, Parag [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai (India); Agrawal, P C [UM-DAE Center of Excellence for Basic Sciences, University of Mumbai, Kalina, Mumbai-400098 (India); Manchanda, R K [University of Mumbai, Kalina, Mumbai-400098 (India); Paul, B, E-mail: rmisra@iucaa.in [Dept. of Astronomy and Astrophysics, Raman Research Institute, Bengaluru-560080 (India)

    2017-02-01

    We report the first analysis of data from AstroSat /LAXPC observations of Cygnus X-1 in 2016 January. LAXPC spectra reveals that the source was in the canonical hard state, represented by a prominent thermal Comptonization component having a photon index of ∼1.8 and high temperature of kT{sub e} > 60 keV along with weak reflection and possible disk emission. The power spectrum can be characterized by two broad lorentzian functions centered at ∼0.4 and ∼3 Hz. The rms of the low-frequency component decreases from ∼15% at around 4 keV to ∼10% at around 50 keV, while that of the high-frequency one varies less rapidly from ∼13.5% to ∼11.5% in the same energy range. The time lag between the hard (20–40 keV) and soft (5–10 keV) bands varies in a step-like manner being nearly constant at ∼50 milliseconds from 0.3 to 0.9 Hz, decreasing to ∼8 milliseconds from 2 to 5 Hz and finally dropping to ∼2 milliseconds for higher frequencies. The time lags increase with energy for both the low and high-frequency components. The event mode LAXPC data allows for flux resolved spectral analysis on a timescale of 1 s, which clearly shows that the photon index increased from ∼1.72 to ∼1.80 as the flux increased by nearly a factor of two. We discuss the results in the framework of the fluctuation propagation model.

  2. Opposing Roles of Calcium and Intracellular ATP on Gating of the Purinergic P2X2 Receptor Channel

    Directory of Open Access Journals (Sweden)

    Milos B. Rokic

    2018-04-01

    Full Text Available P2X2 receptors (P2X2R exhibit a slow desensitization during the initial ATP application and a progressive, calcium-dependent increase in rates of desensitization during repetitive stimulation. This pattern is observed in whole-cell recordings from cells expressing recombinant and native P2X2R. However, desensitization is not observed in perforated-patched cells and in two-electrode voltage clamped oocytes. Addition of ATP, but not ATPγS or GTP, in the pipette solution also abolishes progressive desensitization, whereas intracellular injection of apyrase facilitates receptor desensitization. Experiments with injection of alkaline phosphatase or addition of staurosporine and ATP in the intracellular solution suggest a role for a phosphorylation-dephosphorylation in receptor desensitization. Mutation of residues that are potential phosphorylation sites identified a critical role of the S363 residue in the intracellular ATP action. These findings indicate that intracellular calcium and ATP have opposing effects on P2X2R gating: calcium allosterically facilitates receptor desensitization and ATP covalently prevents the action of calcium. Single cell measurements further revealed that intracellular calcium stays elevated after washout in P2X2R-expressing cells and the blockade of mitochondrial sodium/calcium exchanger lowers calcium concentrations during washout periods to basal levels, suggesting a role of mitochondria in this process. Therefore, the metabolic state of the cell can influence P2X2R gating.

  3. Effects of copper excess and copper deficiency on the structural and electrical properties of bulk Cu{sub x}SnSe{sub 3} with x=1.6–2.2

    Energy Technology Data Exchange (ETDEWEB)

    Wubet, Walelign; Kuo, Dong-Hau, E-mail: dhkuo@mail.ntust.edu.tw

    2015-03-15

    Effects of the Cu variation on the morphological, structural, and electrical properties of bulk Cu{sub x}SnSe{sub 3} (CTSe) with x=1.6–2.2 have been investigated. Dense CTSe pellets with grains of 3–4 µm were obtained after sintering at 550 °C. All CTSe pellets showed a dominant p-type behavior. CTSe at x=2.0 with a hole concentration (n{sub p}) of 1.02×10{sup 18} cm{sup −3} and Hall mobility (μ) of 225 cm{sup 2}/V/s had a highest conductivity (σ) of 39 S/cm. CTSe at x=1.6 with n{sub p} of 5.0×10{sup 17} cm{sup −3} and of 11 cm{sup 2}/V/s had a lowest of 0.90 S/cm. The explanation, based upon vacancies and antisite defects, for the changes in electrical property with the Cu content is supported by the data from lattice parameter. The study in bulk properties of CTSe and its defects is helpful for selecting the suitable absorber composition to fabricate thin film solar cells. - Graphical abstract: Cu{sub 2}SnSe{sub 3} is an absorber candidate for solar cells. The Cu stoichiometry on electrical properties, which is important for CIGS and CZTS, is investigated and the Cu-deficiency composition is recommended. - Highlights: • Cu{sub x}SnSe{sub 3} (CTSe) bulks with 1.6≤x≤2.2 were prepared by reactive sintering. • Cu{sub 2}SnSe{sub 3} with n{sub p} of 1.02×10{sup 18} cm{sup −3} and μ of 225 cm{sup 2}/V/s had highest σ of 39 S/cm. • Cu{sub 1.6}SnSe{sub 3} with n{sub p}=5.0×10{sup 17} cm{sup −3} and μ=11 cm{sup 2}/V/s had lowest σ=0.90 S/cm. • Lower n{sub p} at CTSe at x=1.6 is related to the formation of the Sn-to-Cu defect. • The drop in n{sub p} for CTSe at x=2.2 indicates V{sub Sn}{sup 4−} dominates over Cu{sub Sn}{sup 3−} defect.

  4. Understanding the Long-Term Spectral Variability of Cygnus X-1 from BATSE and ASM Observations

    Science.gov (United States)

    Zdziarski, Andrzej A.; Poutanen, Juri; Paciesas, William S.; Wen, Linqing; Six, N. Frank (Technical Monitor)

    2002-01-01

    We present a spectral analysis of observations of Cygnus X-1 by the RXTE/ASM (1.5-12 keV) and CGRO/BATSE (20-300 keV), including about 1200 days of simultaneous data. We find a number of correlations between intensities and hardnesses in different energy bands from 1.5 keV to 300 keV. In the hard (low) spectral state, there is a negative correlation between the ASM 1.5-12 keV flux and the hardness at any energy. In the soft (high) spectral state, the ASM flux is positively correlated with the ASM hardness (as previously reported) but uncorrelated with the BATSE hardness. In both spectral states, the BATSE hardness correlates with the flux above 100 keV, while it shows no correlation with the flux in the 20-100 keV range. At the same time, there is clear correlation between the BATSE fluxes below and above 100 keV. In the hard state, most of the variability can be explained by softening the overall spectrum with a pivot at approximately 50 keV. The observations show that there has to be another, independent variability pattern of lower amplitude where the spectral shape does not change when the luminosity changes. In the soft state, the variability is mostly caused by a variable hard (Comptonized) spectral component of a constant shape superimposed on a constant soft blackbody component. These variability patterns are in agreement with the dependence of the rms variability on the photon energy in the two states. We interpret the observed correlations in terms of theoretical Comptonization models. In the hard state, the variability appears to be driven mostly by changing flux in seed photons Comptonized in a hot thermal plasma cloud with an approximately constant power supply. In the soft state, the variability is consistent with flares of hybrid, thermal/nonthermal, plasma with variable power above a stable cold disk. Also, based on broadband pointed observations simultaneous with those of the ASM and BATSE, we find the intrinsic bolometric luminosity increases by a

  5. DISAPPEARANCE OF COMET C/2010 X1 (ELENIN): GONE WITH A WHIMPER, NOT A BANG

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing; Jewitt, David, E-mail: jli@igpp.ucla.edu [Department of Earth, Planetary and Space Sciences, University of California at Los Angeles (United States)

    2015-04-15

    We examine the rise and sudden demise of comet C/2010 X1 (Elenin) on its approach to perihelion. Discovered inbound at 4.2 AU, this long-period comet was predicted to become very bright when near perihelion, at 0.48 AU on 2011 September 10. Observations starting 2011 February (heliocentric distance ∼3.5 AU) indeed show the comet to brighten by about 11 mag, with most of the increase occurring inside 1 AU from the Sun. The peak brightness reached m{sub R} = 6 on UT 2011 August 12.95 ± 0.50, when at ∼0.83 AU from the Sun. Thereafter, the comet faded even as the heliocentric distance continued to decrease. We find that most of the surge in brightness in mid-August resulted from dust-particle forward scattering, not from a sudden increase in the activity. A much smaller (∼3 mag) brightening began on UT 2011 August 18 ± 1 (heliocentric distance 0.74 AU), reached a maximum on UT 2011 August 30 ± 1 (at 0.56 AU), and reflects the true breakup of the nucleus. This second peak was matched by a change in the morphology from centrally condensed to diffuse. The estimated cross section of the nucleus when at 1 AU inbound was ∼1 km{sup 2}, corresponding to an equal-area circle of radius 0.6 km. Observations were taken after the second peak using the Canada–France–Hawaii 3.6 m telescope to search for surviving fragments of the nucleus. None were found to a limiting red magnitude r′ = 24.4, corresponding to radii ≲40 m (red geometric albedo = 0.04 assumed). The brightening, the progressive elongation of the debris cloud, and the absence of a central condensation in data taken after UT 2011 August 30 are consistent with disintegration of the nucleus into a power law size distribution of fragments with index q = 3.3 ± 0.2 combined with the action of radiation pressure. In such a distribution, the largest particles contain most of the mass while the smallest particles dominate the scattering cross section and apparent brightness. We speculate about physical

  6. Long term variability of Cygnus X-1. VI. Energy-resolved X-ray variability 1999-2011

    NARCIS (Netherlands)

    Grinberg, V.; Pottschmidt, K.; Böck, M.; Schmid, C.; Nowak, M.A.; Uttley, P.; Tomsick, J.A.; Rodriguez, J.; Hell, N.; Markowitz, A.; Bodaghee, A.; Cadolle Bel, M.; Rothschild, R.E.; Wilms, J.

    2014-01-01

    We present the most extensive analysis of Fourier-based X-ray timing properties of the black hole binary Cygnus X-1 to date, based on 12 years of bi-weekly monitoring with RXTE from 1999 to 2011. Our aim is a comprehensive study of timing behavior across all spectral states, including the elusive

  7. The Soft State of Cygnus X-1 Observed With NuSTAR: A Variable Corona and a Stable Inner Disk

    DEFF Research Database (Denmark)

    Walton, D. J.; Tomsick, J. A.; Madsen, K. K.

    2016-01-01

    We present a multi-epoch hard X-ray analysis of Cygnus X-1 in its soft state based on four observations with the Nuclear Spectroscopic Telescope Array (NuSTAR). Despite the basic similarity of the observed spectra, there is clear spectral variability between epochs. To investigate this variabilit...

  8. Search for gravitational waves from Scorpius X-1 in the first Advanced LIGO observing run with a hidden Markov model

    NARCIS (Netherlands)

    Abbott, B. P.; Abbott, R.; Abbott, D.; Acernese, F.; Ackley, K.; Adams, C.; Phythian-Adams, A.T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agatsuma, K.; Aggarwal, N.T.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allen, G; Allocca, A.; Almoubayyed, H.; Altin, P. A.; Amato, A.; Ananyeva, A.; Anderson, S. B.; Anderson, W. G.; Antier, S.; Appert, S.; Arai, K.; Araya, M. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; AultONeal, K.; Avila-Alvarez, A.; Babak, S.; Bacon, P.; Bader, M. K. M.; Bae, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Banagiri, S.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, R.D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bawaj, M.; Bazzan, M.; Becsy, B.; Beer, C.; Bejger, M.; Belahcene, I.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Etienne, Z. B.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Billman, C. R.; Birch, D J; Birney, R.; Birnholtz, O.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackman, J.; Blair, C. D.; Blari, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bode, N.; Boer, M.; Bogaert, J.G.; Bohe, A.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, A.D.; Brown, D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Bustillo, J. Calderon; Callister, T. A.; Calloni, E.; Camp, J. B.; Canepa, M.; Canizares, P.; Cannon, K. C.; Cao, H.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Carney, M. F.; Diaz, J. Casanueva; Casentini, C.; Caudill, S.; Cavaglia, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Baiardi, L. Cerboni; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, D. S.; Charlton, P.; Chassande-Mottin, E.; Chatterjee, D.; Cheeseboro, B. D.; Chen, H. Y.; Chen, Y; Cheng, H. -P.; Chincarini, A.; Chiummo, A.; Chmiel, T.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, A. J. K.; Chua, S. S. Y.; Chung, A. K. W.; Chung, S.; Ciani, G.; Ciolfi, R.; Cirelli, C. E.; Cirone, A.; Clara, F.; Clark, J. A.; Cleva, F.; Cocchieri, C.; Coccia, E.; Cohadon, P. -F.; Colla, A.; Collette, C. G.; Cominsky, L. R.; Constancio, M., Jr.; Conti, L.; Cooper, S. J.; Corban, P.; Corbitt, T. R.; Corley, K. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J. -P.; Countryman, S. T.; Couvares, P.; Covas, P. B.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cullen, T. J.; Cumming, A.; Cunningham, Laura; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dasgupta, A.; Costa, C. F. Da Silva; Dattilo, V.; Dave, I.; Davier, M.; Davies, G. S.; Davis, D.; Daw, E. J.; Day, B.; De, S.; Debra, D.; Deelman, E; Degallaix, J.; De laurentis, M.; Deleglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.A.; Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Devenson, J.; Devine, R. C.; Dhurandhar, S.; Diaz, M. C.; Di Fiore, L.; Giovanni, M. Di; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Renzo, F.; Doctor, Z.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Dorrington, I.; Douglas, R.; Alvarez, M. Dovale; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Duncan, J.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H. -B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Farinon, S.; Farr, B.; Farr, W. M.; Fauchon-Jones, E. J.; Favata, M.; Fays, M.; Fehrmann, H.; Feicht, J.; Fejer, M. M.; Fernandez-Galiana, A.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M; Fong, H.; Forsyth, P. W. F.; Forsyth, S. S.; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fries, E. M.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H.; Gabel, M.; Gadre, B. U.; Gaebel, S. M.; Gair, J. R.; Gammaitoni, L.; Ganija, M. R.; Gaonkar, S. G.; Garufi, F.; Gaudio, S.; Gaur, G.; Gayathri, V.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, D.J.; George, J.; Gergely, L.; Germain, V.; Ghonge, S.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.P.; Glover, L.; Goetz, E.; Goetz, R.; Gomes, A.S.P.; Gonzalez, Idelmis G.; Castro, J. M. Gonzalez; Gopakumar, A.; Gorodetsky, M. L.; Gossan, S. E.; Lee-Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.M.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Gruning, P.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannuksela, O. A.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Haster, C. -J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Henry, J.A.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Horst, C.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Intini, G.; Isa, H. N.; Isac, J. -M.; Isi, M.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jimenez-Forteza, F.; Johnson, W.; Jones, I.D.; Jones, R.; Jonker, R. J. G.; Ju, L.; Junker, J.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katolik, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kawabe, K.; Kefelian, F.; Keitel, D.; Kemball, A. J.; Kennedy, R.E.; Kent, C.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan., S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J. C.; Kim, W.; Kim, S.W.; Kim, Y.M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kirchhoff, R.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koch, P.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kramer, C.; Kringel, V.; Krishnan, B.; Krolak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kumar, S.; Kuo, L.; Kutynia, A.; Kwang-Cheol, S.; Lackey, B. D.; Lai, K. H.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lee, C.H.; Lee, K.H.; Lee, M.H.; Lee, W. H.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Liu, J.; Lockerbie, N. A.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lovelace, G.; Luck, H.; Lumaca, D.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magana Hernandez, I.; Magana-Sandoval, F.; Magana Zertuche, L.; Magee, R. M.; Majorana, E.; Maksimovic, I.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marka, S.; Marka, Z.; Markakis, C.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matas, A.; Matichard, F.; Matone, L.; Mavalvala, N.; Mayani, R.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McCuller, L.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Mejuto-Villa, E.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minazzoli, O.; Minenkov, Y.; Ming, J.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B.C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, S.D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muniz, E. A. M.; Murray, P.G.; Napier, K.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Nelemans, G.; Nelson, T. J. N.; Gutierrez-Neri, M.; Nery, M.; Neunzert, A.; Newport, J. M.; Newton, G.; Ng, K. K. Y.; Nguyen, T. T.; Nichols, D.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Noack, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ormiston, R.; Ortega, L. F.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, J.; Page, M. A.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pang, B.; Pang, P. T. H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.S; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Castro-Perez, J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poggiani, R.; Popolizio, P.; Porter, E. K.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Purrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Ramirez, K. E.; Rapagnani, P.; Raymond, V.; Razzano, M.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Ricker, P. M.; Rieger, S.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romel, C. L.; Romie, J. H.; Rosinska, D.; Ross, M. P.; Rowan, S.; Rudiger, A.; Ruggi, P.; Ryan, K.; Rynge, M.; Sachdev, Perminder S; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheuer, J.; Schmidt, E.; Schmidt, J; Schmidt, P.; Schnabel, R.B.; Schofield, R. M. S.; Schonbeck, A.; Schreiber, K.E.C.; Schuette, D.; Schulte, B. W.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Seidel, E.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shaffer, T. J.; Shah, A.; Shahriar, M. S.; Shao, L.P.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, António Dias da; Singer, A; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, R. J. E.; Smith, R. J. E.; Son, E. J.; Sonnenberg, J. A.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Stratta, G.; Strigin, S. E.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepanczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tapai, M.; Taracchini, A.; Taylor, J. A.; Taylor, W.R.; Theeg, T.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tonelli, M.; Tornasi, Z.; Torrie, C. I.; Toyra, D.; Travasso, F.; Traylor, G.; Trifiro, D.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tsang, K. W.; Tse, M.; Tso, R.; Tuyenbayev, D.; Ueno, K.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahi, K.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; Van Beuzekom, Martin; van den Brand, J. F. J.; Van Den Broeck, C.F.F.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Varma, V.; Vass, S.; Vasuth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P.J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Vicere, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J. -Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, MT; Walet, R.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, J. Z.; Wang, M.; Wang, Y. -F.; Wang, Y. -F.; Ward, L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L. -W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wessel, E. K.; Wessels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Whittle, C.; Williams, D.; Williams, D.R.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Wofford, J.; Wong, G.W.K.; Worden, J.; Wright, J.L.; Wu, D.S.; Wu, G.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, Hang; Yu, Haocun; Yvert, M.; Zadrozny, A.; Zanolin, M.; Zelenova, T.; Zendri, J. -P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y. -H.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zweizig, J.; Suvorova, S.; Moran, W.; Evans, J.R.

    2017-01-01

    Results are presented from a semicoherent search for continuous gravitational waves from the brightest low-mass X-ray binary, Scorpius X-1, using data collected during the first Advanced LIGO observing run. The search combines a frequency domain matched filter (Bessel-weighted F-statistic) with a

  9. The Reflection Component from Cygnus X-1 in the Soft State Measured by NuSTAR and Suzaku

    DEFF Research Database (Denmark)

    Tomsick, John A.; Nowak, Michael A.; Parker, Michael

    2014-01-01

    The black hole binary Cygnus X-1 was observed in late-2012 with the Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku, providing spectral coverage over the ~1-300 keV range. The source was in the soft state with a multi-temperature blackbody, power-law, and reflection components along...

  10. Theoretical study on photon-phonon coupling at (001)-(2 x 1) surfaces of Ge and {alpha}-Sn

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Sanchez, F.L. [Escuela de Ciencias, Universidad Autonoma ' ' Benito Juarez' ' de Oaxaca, Av. Universidad S/N, Ex-Hacienda de Cinco Senores, Ciudad Universitaria, Oaxaca de Juarez, Oax., 68120 (Mexico); Perez-Rodriguez, F. [Instituto de Fisica, Benemerita Universidad Autonoma de Puebla, Apdo. Post. J-48, Puebla, Pue. 72570 (Mexico)

    2011-06-15

    We present a study of the far-infrared reflectance anisotropy spectra for (001) surfaces of Ge and {alpha}-Sn in the (2 x 1) asymmetric dimer geometry, which exhibit a resonance structure associated with the excitation of surface phonon modes. We have employed a theoretical formalism, based on the adiabatic bond-charge model (ABCM), for computing the far-infrared reflectance anisotropy spectra. In comparison with previous theoretical results for silicon and diamond surfaces, the resonance structure in the reflectance anisotropy spectrum for Ge(001)-(2 x 1) turns out to be similar to that observed in the spectrum for the Si(001)-(2 x 1) surface, whereas the spectrum for {alpha}-Sn(001)-(2 x 1) surface is noticeably different from the others. We have established a trend of far-infrared reflectance anisotropy spectra for IV(001) surfaces: the weaker dimer strength, the stronger resonances of low-frequency surface phonons. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Hard x ray observations of Vela X-1 and A0535+26 with HEXE: Discovery of cyclotron lines

    Science.gov (United States)

    Kendziorra, E.; Mony, B.; Kretschmar, P.; Maisack, M.; Staubert, R.; Doebereiner, S.; Englhauser, J.; Pietsch, W.; Reppin, C.; Truemper, J.

    1992-01-01

    The X ray pulsars Vela X-1 (4U 0900-40) and A0535+26) were observed with the High Energy X ray Experiment (HEXE) onboard the Mir space station at energies above 20 keV. The pulse profiles of Vela X-1 (P = 283.22 s for JD 244 7486) and A0535+26 (P = 103.27 s for JD 244 7626) were measured up to at least 100 keV. The time averaged pulse profiles of the two sources both show a clear double peak structure with an asymmetric main pulse and a more symmetric secondary pulse. The spectrum of the main pulse is significantly harder than that of the secondary. Pulse phase resolved spectra show absorption features at 54 keV and possibly 27 keV for Vela X-1 and around 100 keV for A0535+26. If these features are interpreted as second and first harmonic (fundamental) cyclotron absorption lines, lower limits are derived of 2.6 x 10(exp 12) and 4.3 x 10(exp 12) Gauss for the magnetic fields of the neutron stars in Vela X-1 and A0535+26, respectively.

  12. Critical evaluation of measured line positions of 14N16O in X2П state

    Science.gov (United States)

    Sulakshina, O. N.; Borkov, Yu. G.

    2018-04-01

    All available line positions for unresolved and resolved Λ-doublets of the 14N16O molecule in the X2 П state were collected from the literature and tested using the RITZ computer code. These data have been critically analysed and used to obtain the most complete set of 1789 experimental energy levels of unresolved Λ-doublets covering the 0-35,866 cm-1 interval. A set of 425 experimental energy levels of resolved Λ-doublets covering the 0-5957 cm-1 interval for two states 2П1/2 and 2П3/2 also have been obtained. These levels together with calculated correlation matrix can be used to generate the precise list of transitions with confidence intervals. Comparisons with the HITRAN as well as with Amiot calculations are discussed. The systematic shift between experimental energy levels of unresolved Λ-doublets and those calculated by Amiot for 2П3/2 state was found. The same systematic shift for transitions frequencies of unresolved Λ-doublets in forbidden subbands 2П1/2↔2П3/2 is also established in the HITRAN database. Comparison of the RITZ energy levels with calculated energy levels by Wong at al. was also done. It was found, that experimental RITZ energy levels for resolved Λ-doublets of 14N16O coincide with those calculated by Wong at al. within experimental uncertainties.

  13. Antiferromagnetism, structural instability and frustration in intermetallic AFe4X2 systems

    Science.gov (United States)

    Rosner, Helge; Bergmann, Christoph; Weber, Katharina; Kraft, Inga; Mufti, N.; Klauss, Hans-Henning; Dellmann, T.; Woike, T.; Geibel, Christoph

    2013-03-01

    Magnetic systems with reduced dimensionality or frustration attract strong interest because these features lead to an increase of quantum fluctuations and often result in unusual properties. Here, we present a detailed study of the magnetic, thermodynamic, and structural properties of the intermetallic AFe4X2 compounds (A=Sc,Y,Lu,Zr; X=Si,Ge) crystallizing in the ZrFe4Si2 structure type. Our results evidence that these compounds cover the whole regime from frustrated AFM order up to an AFM quantum critical point. Susceptibility χ(T), specific heat, resistivity, and T-dependent XRD measurements were performed on polycrystalline samples. In all compounds we observed a Curie-Weiss behavior in χ(T) at high T indicating a paramagnetic moment of about 3μB/Fe. Magnetic and structural transitions as previously reported for YFe4Ge2 occur in all compounds with trivalent A. However, transition temperatures, nature of the transition as well as the relation between structural and magnetic transitions change significantly with the A element. Low TN's and large θCW /TN ratios confirm the relevance of frustration. The results are analyzed and discussed with respect to electronic, structural and magnetic instabilities applying DFT calculations. Financial support from the DFG (GRK 1621) is acknowledged

  14. A simulation study of rater agreement measures with 2x2 contingency tables

    Directory of Open Access Journals (Sweden)

    Ana Benavente

    2011-01-01

    Full Text Available Un estudio de simulacion de medidas de acuerdo entre observadores para tablas de contingencia 2x2. Mediante un estudio de simulacion se aborda una comparacion entre seis medidas obtenidas usando tres enfoques diferentes para la evaluacion del acuerdo. Los coeficientes de acuerdo elegidos fueron sigma de Bennet (1954, Pi de Scott (1955, Kappa de Cohen (1960 y gamma de Gwet (2001; 2008 para representar el enfoque clasico descriptivo, el coeficiente alpha de Aickin (1990, para representar el enfoque de los modelos loglineal y mixtura ("mixture models" y la medida delta de Martin and Femia (2004 para representar el enfoque de los test de eleccion multiple. Los resultados obtenidos confirman que los coeficientes Pi y kappa presentan diferencias notables en relacion a los restantes coeficientes particularmente en presencia de valores extremos de prevalencia y sesgo entre observadores. El mejor comportamento fue observado con los coeficientes alpha de Bennet y delta de Martin and Femia para todos los valores de prevalencia y sesgo entre observadores.

  15. Application of 119Sn Moessbauer spectroscopy to investigations of RET2-X2-type phases

    International Nuclear Information System (INIS)

    Goerlich, E.

    1991-01-01

    Moessbauer spectroscopy of 119 Sn is an effective tool to study nuclear hyperfine interactions which in turn are important as a source of information complementary to that supplied by ''classical'' methods. However, particularly when the effects are subtle, experimental conditions as well as data analysis should be handled with care. The attention is devoted primarily to the finite absorber thickness effects. As examples serve our recent results obtained from investigations of ternary tetragonal phases of RET 2 X 2 -type. In EuPd 2 Si 2 mixed valent system 119 Sn was used as probe which detects the influence of Eu-valency change at a distant site of Si. Electrical resistivity measurements in CeNi 2 Sn 2 may indicate a Kondo-type behaviour while Moessbauer effect leads to the conclusion in favour of a magnetically ordered state. The analysis of resonance absorption spectra of CeAg 2 Sn 2 using a full transmission integral indicates the presence of a metallic β-tin in the sample, while data fitting within the thin absorber approximation has lead to the opposite conclusion. Neither in CeNi 2 Sn 2 nor in ErNi 2 Sn 2 the temperature dependence of the recoil free factors alone cannot explain the observed broadening of spectra at low temperatures. (author). 14 refs, 13 figs

  16. MULTI-LOOP CONTROL DESIGN IN MULTIVARIABLE (2X2 CONTINUOUS STIRRED TANK REACTOR

    Directory of Open Access Journals (Sweden)

    Abdul Wahid

    2015-06-01

    Full Text Available With this study, the design and tuning of multi-loop for multivariable (2x2 CSTR will be made in order to achieve optimum CSTR control performance. This study used Bequette model reactor and MATLAB software and is expected to be able to cope with disturbances in the reactor so that the reactor system is able to stabilize quickly despite the distractions. In this study, the design will be made using multi-loop approach, along with PI controller as the next step. Then, BLT and auto-tune tuning method will be used in PI controller and given disturbances to both of tuning method. The controller performances are then compared. Results of the study are then analyzed for discussions and conclusions. Results from this study have shown that in terms of disturbance rejection, BLT is better than auto-tune based on comparison between both of controller performances. For IAE for the case of temperature, BLT is 30% better than auto-tune, but it is almost the same for the case of concentration. For settling time for the case of concentration, BLT is 30% better than auto-tune, and for the case of temperature, BLT is 18% better than auto-tune. For rise time for the case of concentration and temperature, BLT is 30% better than auto-tune.

  17. Neutron scattering study of MnX2 (X = Br, I)

    International Nuclear Information System (INIS)

    Sato, Taku; Kadowaki, Hiroaki.

    1993-01-01

    Successive magnetic phase transitions in MnX 2 (X = Br, I), found by bulk measurements, are studied by neutron scattering experiments. There occur two (T N1 = 2.32K, T N2 = 2.17K) and three (T N1 = 3.95K, T N2 = 3.8K, T N3 = 3.45K) phase transitions in MnBr 2 and MnI 2 , respectively. We have found that magnetic structures of the both compounds in the intermediate temperature phases (MnBr 2 : T N1 > T > T N2 ; MnI 2 : T N1 > T > T N3 ) are transverse sinusoidally-modulated structures with incommensurate wave-vectors which vary as a function of temperature. As the temperature is lowered into the lowest temperature phases, the magnetic structures change via first order transition into ↑↑↓↓ and a helical structure for MnBr 2 and MnI 2 , respectively, which were determined by previous experiments. The successive phase transitions in MnBr 2 are accounted for quantitatively using a mean field approximation of a Hamiltonian consisting of exchange interactions up to third inter- and third intra-layer neighbor sites and the dipolar interaction. (author)

  18. Ploidy Variation in Hybrids from Interploid 3x X 2x Crosses in Musa

    Directory of Open Access Journals (Sweden)

    Osuji, JO.

    1997-01-01

    Full Text Available Hybrids were obtained after in vitro germination of embryos from interploid crosses between triploid 'French' plantain cultivars (Musa spp. AAB group 'Ntanga 2' and 'Bobby Tannap' with diploid banana (Ivlusa acuminata subsp. burmannicoidesj 'Calcutta 4'. Cross-pollinated bunches were harvested at full maturity and ripened with acetylene in a room for 4 days. Seeds were extracted from peeled ripe fruits by squashing. Embryos from the seeds were excised aseptically after 2 days and germinated in vitro. Seedlings were subsequently planted in early evaluation trials after acclimatising in the greenhouse. Chromosome counts were carried out on root tips of mature and maiden suckers to determine ploidy levels using a modified squashing technique. Counts showed that two of the hybrids were aneuploids (trisomies with somatic chromosome number of 2n = 2x + 1 = 23, one hybrid was diploid while the other two were tetraploids. Tetraploids are the most promising hybrids for the genetic improvement of plantains. Diploids are valuable material for further improvement of the plantain genome at this ploidy level. Trisomies provide means for further characterisation of the Musa genome and physical gene mapping in plantain and banana.

  19. Magnetic and crystallographic properties of Gd(Cu/sub 1-x/Ni/sub x/)2 and Gd(Cu/sub 1-x/Al/sub x/)2 intermetallic compounds

    International Nuclear Information System (INIS)

    Borombaev, M.K.; Levitin, R.Z.; Markosyan, A.S.; Snegirev, V.V.

    1986-01-01

    Magnetization, paramagnetic susceptibility, and temperature dependence of lattice parameters of Gd(Cu/sub 1-x/Ni/sub x/) 2 (0 2 (0 2 -type structure have been studied in a wide range of temperatures. Below the ordering temperature anomalies in thermal expansion along the crystallographic axes a, b, and c enabled to distinguish between various types of magnetic arrangements. The Gd(Cu/sub 1-x/Ni/sub x/) 2 system has two types of antiferromagnetic phases: AF1 (0 = 0.13 the system orders ferromagnetically. In the Gd(Cu/sub 1-x/Al/sub x/) 2 system two magnetic phases AF1 and AF3 occur in the concentration regions 0 <= x <= 0.035 and 0.04 <= x <= 0.07, respectively. The obtained results are discussed in terms of the RKKY model via the changing conduction electron concentration. (author)

  20. Energy consumption of ProTaper Next X1 after glide path with PathFiles and ProGlider.

    Science.gov (United States)

    Berutti, Elio; Alovisi, Mario; Pastorelli, Michele Angelo; Chiandussi, Giorgio; Scotti, Nicola; Pasqualini, Damiano

    2014-12-01

    Instrument failure caused by excessive torsional stress can be controlled by creating a manual or mechanical glide path. The ProGlider single-file system (Dentsply Maillefer, Ballaigues, Switzerland) was recently introduced to perform a mechanical glide path. This study was designed to compare the effect of a glide path performed with PathFiles (Dentsply Maillefer) and ProGlider on torque, time, and pecking motion required for ProTaper Next X1 (Dentsply Maillefer) to reach the full working length in simulated root canals. Forty Endo Training Blocks (Dentsply Maillefer) were used. Twenty were prepared with a mechanical glide path using PathFiles 1 and 2 (the PathFile group), and 20 were prepared with a mechanical glide path using a ProGlider single file (the ProGlider group). All samples were shaped with ProTaper Next X1 driven by an endodontic motor connected to a digital wattmeter. The required torque for root canal instrumentation was analyzed by evaluating the electrical power consumption of the endodontic engine. Electric power consumption (mW/h), elapsed time (seconds), and number of pecking motions required to reach the full working length with ProTaper Next X1 were calculated. Differences among groups were analyzed with the parametric Student t test for independent data (P < .05). Elapsed time and electric power consumption were significantly different between groups (P = .0001 for both). ProGlider appears to perform more efficiently than PathFiles in decreasing electric power consumption of ProTaper Next X1 to reach the full working length. This study confirmed the ability of ProGlider to reduce stress in ProTaper Next X1 during shaping through a glide path and preliminary middle and coronal preflaring. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  1. P2X1 receptors localized in lipid rafts mediate ATP motor responses in the human vas deferens longitudinal muscles.

    Science.gov (United States)

    Donoso, María Verónica; Norambuena, Andrés; Navarrete, Camilo; Poblete, Inés; Velasco, Alfredo; Huidobro-Toro, Juan Pablo

    2014-02-01

    To assess the role of the P2X1 receptors (P2X1R) in the longitudinal and circular layers of the human vas deferens, ex vivo-isolated strips or rings were prepared from tissue biopsies to record isometric contractions. To ascertain its membrane distribution, tissue extracts were analyzed by immunoblotting following sucrose gradient ultracentrifugation. ATP, alpha,beta-methylene ATP, or electrical field stimulation elicited robust contractions of the longitudinal layer but not of the circular layer which demonstrated inconsistent responses. Alpha,beta-methylene ATP generated stronger and more robust contractions than ATP. In parallel, prostatic segments of the rat vas deferens were examined. The motor responses in both species were not sustained but decayed within the first minute, showing desensitization to additional applications. Cross-desensitization was established between alpha,beta-methylene ATP or ATP-evoked contractions and electrical field stimulation-induced contractions. Full recovery of the desensitized motor responses required more than 30 min and showed a similar pattern in human and rat tissues. Immunoblot analysis of the human vas deferens extracts revealed a P2X1R oligomer of approximately 200 kDa under nonreducing conditions, whereas dithiothreitol-treated extracts showed a single band of approximately 70 kDa. The P2X1R was identified in ultracentrifugation fractions containing 15%-29% sucrose; the receptor localized in the same fractions as flotillin-1, indicating that it regionalized into smooth muscle lipid rafts. In conclusion, ATP plays a key role in human vas deferens contractile responses of the longitudinal smooth muscle layer, an effect mediated through P2X1Rs.

  2. 2 x 2 achievement goals profilEs in chilean CompetiTIve and recreational athletes: a first look

    Directory of Open Access Journals (Sweden)

    Marc R. Lochbaum

    2016-02-01

    Full Text Available Purpose: was to examine the 2 x 2 achievement goal profiles of Chilean young adults regularly participating in competitive and recreational sport. Materials: participants were 108 female and 132 males who were recruited from the Valparaiso and Viña del Mar areas of Chile. Participants completed a valid and reliable measure of the 2 x 2 achievement goals referenced to sport participation. Results: indicated that the entire sample significantly ( p - .05 and very meaningfully (Hedges’ g range 1.13 - 2.91 endorsed the mastery-approach goal more so than the other three achievement goals. Male participants significantly ( p - .05 endorsed both approach goals and the mastery goal contrast more so than the female participants. These differences approached medium in meaningfulness (Hedges’ g range .40 - .46. Significant differences did not exist between competitive and recreational athletes on any of the achievement goals or goal contrasts. Confirming the lack of significant differences were the computed small to negligible in magnitude effect sizes. Conclusions: the present data were a first look into profiling sport participants on the 2 x 2 achievement goals in Chile. Given this sample of Chilean participants endorsed the performance goals far less than found in the sport psychology 2 x 2 achievement goal literature, more research is needed before these results are generalized to Chilean sport participants. Future research must also examine the relationships of antecedents and consequences to the 2 x 2 achievement goals to advance sport psychology in Chile.

  3. 2 x 2 Achievement Goals and Achievement Emotions: A Cluster Analysis of Students' Motivation

    Science.gov (United States)

    Jang, Leong Yeok; Liu, Woon Chia

    2012-01-01

    This study sought to better understand the adoption of multiple achievement goals at an intra-individual level, and its links to emotional well-being, learning, and academic achievement. Participants were 480 Secondary Two students (aged between 13 and 14 years) from two coeducational government schools. Hierarchical cluster analysis revealed the…

  4. Interpretation of chest radiographs with a high-resolution (2,000 x 2,000 x 12 bit) display

    International Nuclear Information System (INIS)

    Cox, G.G.

    1989-01-01

    This paper presents an evaluation of high-resolution (2K x 2Kx 12 bit) display for interpretation of chest radiographs. Three radiologists chose a total of 165 chest radiographs to ensure representation of nine signs: apical pleural scarring, chronic obstructive pulmonary disease, interstitial processes, atelectasis, pneumothorax, hilar mass, pleural effusion, pneumonia, and nodules. Each chest film was digitized to 4Kx 4Kx 12 bit and averaged to 2Kx 2Kx 12 bit and printed on a laser film printer. The 2K x 2K x 12-bit images were displayed and interactively windowed on a 2K x 2K x 12-bit high-resolution gray-scale cathode ray tube display. Six radiologists, none of whom participated in the case selection process, then interpreted a mixture of the screen film chest radiographs, the laser printed 2K chest radiographs, and the high resolution displayed 2K images

  5. On the System of Diophantine Equations x2-6y2=-5 and x=az2-b

    Directory of Open Access Journals (Sweden)

    Silan Zhang

    2014-01-01

    Full Text Available Mignotte and Pethö used the Siegel-Baker method to find all the integral solutions (x,y,z of the system of Diophantine equations x2-6y2=-5 and x=2z2-1. In this paper, we extend this result and put forward a generalized method which can completely solve the family of systems of Diophantine equations x2-6y2=-5 and x=az2-b for each pair of integral parameters a,b. The proof utilizes algebraic number theory and p-adic analysis which successfully avoid discussing the class number and factoring the ideals.

  6. Structure and stability of small Li2 +(X2Σ+ g )-Xen (n = 1-6) clusters

    Science.gov (United States)

    Saidi, Sameh; Ghanmi, Chedli; Berriche, Hamid

    2014-04-01

    We have studied the structure and stability of the Li2 +(X2Σ+ g )Xe n ( n = 1-6) clusters for special symmetry groups. The potential energy surfaces of these clusters, are described using an accurate ab initio approach based on non-empirical pseudopotential, parameterized l-dependent polarization potential and analytic potential forms for the Li+Xe and Xe-Xe interactions. The pseudopotential technique has reduced the number of active electrons of Li2 +(X2Σ+ g )-Xe n ( n = 1-6) clusters to only one electron, the Li valence electron. The core-core interactions for Li+Xe are included using accurate CCSD(T) potential fitted using the analytical form of Tang and Toennies. For the Xe-Xe potential interactions we have used the analytical form of Lennard Jones (LJ6 - 12). The potential energy surfaces of the Li2 +(X2Σ+ g )Xe n ( n = 1-6) clusters are performed for a fixed distance of the Li2 +(X2Σ+ g ) alkali dimer, its equilibrium distance. They are used to extract information on the stability of the Li2 +(X2Σ+ g Xe n ( n = 1-6) clusters. For each n, the stability of the different isomers is examined by comparing their potential energy surfaces. Moreover, we have determined the quantum energies ( D 0), the zero-point-energies (ZPE) and the ZPE%. To our best knowledge, there are neither experimental nor theoretical works realized for the Li2 +(X2Σ+ g Xe n ( n = 1-6) clusters, our results are presented for the first time.

  7. Elko 1/sup 0/ x 2/sup 0/ NTMS area: Nevada and Utah. Data report

    Energy Technology Data Exchange (ETDEWEB)

    Fay, W.M.

    1980-07-01

    Results of ground water and surface sediment reconnaissance in the National Topographic Map Series (NTMS) Elko 1/sup 0/ x 2/sup 0/ quadrangle are presented. The target sampling density was one site per 12 square kilometers. This resulted in 1713 sediment samples being collected; however, dry conditions and sparce population contributed to the relatively small number of ground water (154) samples collected. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Statistical summaries of data and a brief description of results are given. A generalized geologic map and a summary of the geology of the area are included. Data from ground water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements where applicable (water temperature, well description, and scintillometer reading), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, He, Mg, Mn, Na, and V). Data from sediment sites include (1) stream water chemistry measurements (where available) for pH, conductivity, and alkalinity, and (2) elemental analyses (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (coordinates, vegetation, etc.) are also tabulated. Areal distribution maps, histograms, and cumulative frequency plots for most elements, U/Th and U/Hf ratios, and scintillometer readings for sediment samples are included.

  8. Grand Canyon 1/sup 0/ x 2/sup 0/ NTMS area: Arizona. Data report

    Energy Technology Data Exchange (ETDEWEB)

    Koller, G R

    1979-01-01

    This data report presents results of ground water and stream/surface sediment reconnaissance in the National Topographic Map Series (NTMS) Grand Canyon 1/sup 0/ x 2/sup 0/ quadrangle. Surface samples (sediment) were collected from 1013 sites. The target sampling density was one site per 16 square kilometers (six square miles). Ground water samples were collected at 84 sites. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Statistical summaries of data and a brief description of results are given. A generalized geologic map and a summary of the geology of the area are included. Data from ground water sites (on microfiche in pocket) include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements where applicable (water temperature, well description, and scintillometer reading), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, He, Mg, Mn, Na, and V). Data from sediment sites (also on microfiche in pocket) include (1) stream water chemistry measurements (pH, conductivity, and alkalinity), and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. Areal distribution maps, histograms, and cumulative frequency plots for most elements, U/Th, U/Hf, and Th/La ratios, and scintillometer readings for sediment samples are included on the microfiche.

  9. Ritzville 1/sup 0/ x 2/sup 0/ NTMS area, Washington: data report

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C.B.

    1980-07-01

    This data report presents results of ground water and stream/surface sediment reconnaissance in the National Topographic Map Series (NTMS) Ritzville 1/sup 0/ x 2/sup 0/ quadrangle. Surface samples (sediment) were collected from 1063 sites. The target sampling density was one site per 20 square kilometers (eight square miles). Dry conditions contributed to the relatively small number (109) of surface water samples collected. Ground water samples were collected at 830 sites. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Statistical summaries of data and a brief description of results are given. A generalized geologic map and a summary of the geology of the area are included. Data from ground water sites include: (1) water chemistry measurements (pH, conductivity, and alkalinity); (2) physical measurements where applicable (water temperature, well description, and scintillometer reading); and (3) elemental analyses (U, Al, Br, Cl, Dy, F, He, Mg, Mn, Na, and V). Data from sediment sites include: (1) stream water chemistry measurements where applicable (pH, conductivity, and alkalinity); and (2) elemental analyses for sediment samples (U, Th, Hf, Al,Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulatd. Areal distribution maps, histograms, and cumulative frequency plots for most elements; U/Th, U/Hf, and Th/La ratios; and scintillometer readings for sediment samples are included on the microfiche.

  10. Generalized Measure of Departure from No Three-Factor Interaction Model for 2 x 2 x K Contingency Tables

    Directory of Open Access Journals (Sweden)

    Yohei Ban

    2008-12-01

    Full Text Available For 2 x 2 x K contingency tables, Tomizawa considered a Shannon entropy type measure to represent the degree of departure from a log-linear model of no three-factor interaction (the NOTFI model. This paper proposes a generalization of Tomizawa's measure for 2 x 2 x K tables. The measure proposed is expressed by using Patil-Taillie diversity index or Cressie-Read power-divergence. A special case of the proposed measure includes Tomizawa's measure. The proposed measure would be useful for comparing the degrees of departure from the NOTFI model in several tables.

  11. The Discovery of an Outburst and Pulsed X-ray Flux from SMC X-2 from RXTE Observations

    CERN Document Server

    Corbet, R H D; Coe, M J; Laycock, S; Handler, G

    2001-01-01

    Rossi X-ray Timing Explorer All Sky Monitor observations of SMC X-2 show that the source experienced an outburst in January to April 2000 reaching a peak luminosity of greater than ~10^38 ergs s^-1. RXTE Proportional Counter Array observations during this outburst reveal the presence of pulsations with a 2.37s period. However, optical photometry of the optical counterpart showed the source to be still significantly fainter than it was more than half a year after the outburst in the 1970s when SMC X-2 was discovered.

  12. Ab initio study of vibronic transitions between x2π and 12Σ+ electronic states of HCP+ ion

    Directory of Open Access Journals (Sweden)

    Stojanović Ljiljana

    2013-01-01

    Full Text Available The ground and low-lying excited doublet electronic states of the HCP+ ion were studied by means of multireference configuration interaction method. Vibronic energy levels of the X2Π state of Σ, Π, Δ, and Φ symmetry, up to the 2500 cm-1, have been calculated variationally, employing previously developed ab initio methods which take into account vibronic and spin-orbit interactions. Obtained vibronic wave functions were used to estimate transition moments between vibronic energy levels of the X2Π and 12Σ+ electronic states. Results were compared to available experimental and theoretical data. [Projekat Ministarstva nauke Republike Srbije, br. 172040

  13. Weak ferrimagnetism, compensation point and magnetization reversal in Ni(HCOO)2x2H2O

    International Nuclear Information System (INIS)

    Kageyama, H.; Khomskii, D.I.; Levitin, R.Z.; Vasiliev, A.N.

    2003-01-01

    Nickel (II) format dihydrate Ni(HCOO) 2 x2H 2 O shows peculiar magnetic response at T N =15.5 K. The magnitude of weak magnetic moment increases initially below T N , equals zero at T*=8.5 K and increases again at lowering temperature. The sign of low field magnetization at any given temperature is determined by the sample's magnetic prehistory and the signs are opposite to each other at T N . This behavior suggests that Ni(HCOO) 2 x2H 2 O is a weak ferrimagnet and T* is a compensation point

  14. Instructional Advice, Time Advice and Learning Questions in Computer Simulations

    Science.gov (United States)

    Rey, Gunter Daniel

    2010-01-01

    Undergraduate students (N = 97) used an introductory text and a computer simulation to learn fundamental concepts about statistical analyses (e.g., analysis of variance, regression analysis and General Linear Model). Each learner was randomly assigned to one cell of a 2 (with or without instructional advice) x 2 (with or without time advice) x 2

  15. Swift/XRT detection of an X-ray flare and jet emission from Cir X-1

    Science.gov (United States)

    Kong, A. K. H.; Yang, Y.-J.

    2010-06-01

    Following the detection of a brightening and several X-ray bursts of Cir X-1 (ATel #2608,#2643,#2650,#2651,#2653; Linares et al. arXiv:1006.1379), the source has returned to low flux level since June based on observations taken with RXTE/ASM and MAXI/GSC. We examined the Swift/XRT imaging mode data taken on 2010 June 6 and June 10. On June 6 (at orbital phase 0.8; defined by Stewart et al. 1993), the 0.3-10 keV XRT count rate of Cir X-1 is about 0.07 c/s while it brightened to 0.8 c/s on June 10 (at phase 0.03).

  16. Search for very high-energy gamma-ray emission from the microquasar Cygnus X-1 with the MAGIC telescopes

    Science.gov (United States)

    Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Arcaro, C.; Babić, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Bhattacharyya, W.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Carosi, R.; Carosi, A.; Chatterjee, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Cumani, P.; da Vela, P.; Dazzi, F.; de Angelis, A.; de Lotto, B.; de Oña Wilhelmi, E.; di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Engelkemeier, M.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Giammaria, P.; Godinović, N.; Gora, D.; Guberman, D.; Hadasch, D.; Hahn, A.; Hassan, T.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Ishio, K.; Konno, Y.; Kubo, H.; Kushida, J.; Kuveždić, D.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Maggio, C.; Majumdar, P.; Makariev, M.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Minev, M.; Mirzoyan, R.; Moralejo, A.; Moreno, V.; Moretti, E.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Ninci, D.; Nishijima, K.; Noda, K.; Nogués, L.; Paiano, S.; Palacio, J.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Pedaletti, G.; Peresano, M.; Perri, L.; Persic, M.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Garcia, J. R.; Reichardt, I.; Rhode, W.; Ribó, M.; Rico, J.; Righi, C.; Saito, T.; Satalecka, K.; Schroeder, S.; Schweizer, T.; Sitarek, J.; Šnidarić, I.; Sobczynska, D.; Stamerra, A.; Strzys, M.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres, D. F.; Torres-Albà, N.; Treves, A.; Vanzo, G.; Vazquez Acosta, M.; Vovk, I.; Ward, J. E.; Will, M.; Zarić, D.; MAGIC Collaboration; Bosch-Ramon, V.; Pooley, G. G.; Trushkin, S. A.; Zanin, R.

    2017-12-01

    The microquasar Cygnus X-1 displays the two typical soft and hard X-ray states of a black hole transient. During the latter, Cygnus X-1 shows a one-sided relativistic radio-jet. Recent detection of the system in the high energy (HE; E ≳ 60 MeV) gamma-ray range with Fermi-LAT associates this emission with the outflow. Former MAGIC observations revealed a hint of flaring activity in the very high-energy (VHE; E ≳ 100 GeV) regime during this X-ray state. We analyse ∼97 h of Cygnus X-1 data taken with the MAGIC telescopes between July 2007 and October 2014. To shed light on the correlation between hard X-ray and VHE gamma rays as previously suggested, we study each main X-ray state separately. We perform an orbital phase-folded analysis to look for variability in the VHE band. Additionally, to place this variability behaviour in a multiwavelength context, we compare our results with Fermi-LAT, AGILE, Swift-BAT, MAXI, RXTE-ASM, AMI and RATAN-600 data. We do not detect Cygnus X-1 in the VHE regime. We establish upper limits for each X-ray state, assuming a power-law distribution with photon index Γ = 3.2. For steady emission in the hard and soft X-ray states, we set integral upper limits at 95 per cent confidence level for energies above 200 GeV at 2.6 × 10-12 photons cm-2 s-1 and 1.0 × 10-11 photons cm-2 s-1, respectively. We rule out steady VHE gamma-ray emission above this energy range, at the level of the MAGIC sensitivity, originating in the interaction between the relativistic jet and the surrounding medium, while the emission above this flux level produced inside the binary still remains a valid possibility.

  17. The theoretical character of the X1Σ+ and A1Σ+ states of ScN

    International Nuclear Information System (INIS)

    Feng-Juan, Bai; Chuan-Lu, Yang; Qi, Qian; Ling, Zhang

    2009-01-01

    This paper calculates the potential energy curves (PECs) of the ground state (X 1 Σ + ) and excited state (A 1 Σ + ) of ScN molecule by multireference configuration interaction method. The correct character of the PECs has been gripped while they had been improperly reported in the literature. Based on the PECs, the spectroscopic parameters and vibrational energy levels are determined, and compared with experimental data and other theoretical works available at the present. (atomic and molecular physics)

  18. X-RAY OUTFLOWS AND SUPER-EDDINGTON ACCRETION IN THE ULTRALUMINOUS X-RAY SOURCE HOLMBERG IX X-1

    International Nuclear Information System (INIS)

    Walton, D. J.; Harrison, F. A.; Miller, J. M.; Reis, R. C.; Fabian, A. C.; Roberts, T. P.; Middleton, M. J.

    2013-01-01

    Studies of X-ray continuum emission and flux variability have not conclusively revealed the nature of ultraluminous X-ray sources (ULXs) at the high-luminosity end of the distribution (those with L X ≥ 10 40 erg s –1 ). These are of particular interest because the luminosity requires either super-Eddington accretion onto a black hole of mass ∼10 M ☉ or more standard accretion onto an intermediate-mass black hole. Super-Eddington accretion models predict strong outflowing winds, making atomic absorption lines a key diagnostic of the nature of extreme ULXs. To search for such features, we have undertaken a long, 500 ks observing campaign on Holmberg IX X-1 with Suzaku. This is the most sensitive data set in the iron K bandpass for a bright, isolated ULX to date, yet we find no statistically significant atomic features in either emission or absorption; any undetected narrow features must have equivalent widths less than 15-20 eV at 99% confidence. These limits are far below the ∼>150 eV lines expected if observed trends between mass inflow and outflow rates extend into the super-Eddington regime and in fact rule out the line strengths observed from disk winds in a variety of sub-Eddington black holes. We therefore cannot be viewing the central regions of Holmberg IX X-1 through any substantial column of material, ruling out models of spherical super-Eddington accretion. If Holmberg IX X-1 is a super-Eddington source, any associated outflow must have an anisotropic geometry. Finally, the lack of iron emission suggests that the stellar companion cannot be launching a strong wind and that Holmberg IX X-1 must primarily accrete via Roche-lobe overflow

  19. Discovery of a 115 Day Orbital Period in the Ultraluminous X-ray Source NGC 5408 X-1

    Science.gov (United States)

    Strohmayer, Tod E.

    2009-01-01

    We report the detection of a 115 day periodicity in SWIFT/XRT monitoring data from the ultraluminous X-ray source (ULX) NGC 5408 X-1. Our o ngoing campaign samples its X-ray flux approximately twice weekly and has now achieved a temporal baseline of ti 485 days. Periodogram ana lysis reveals a significant periodicity with a period of 115.5 +/- 4 days. The modulation is detected with a significance of 3.2 x 10(exp -4) . The fractional modulation amplitude decreases with increasing e nergy, ranging from 0.13 +/- 0.02 above 1 keV to 0.24 +/- 0.02 below 1 keV. The shape of the profile evolves as well, becoming less sharply peaked at higher energies. The periodogram analysis is consistent wi th a periodic process, however, continued monitoring is required to c onfirm the coherent nature of the modulation. Spectral analysis indic ates that NGC 5408 X-1 can reach 0.3 - 10 keV luminosities of approxi mately 2 x 10 40 ergs/s . We suggest that, like the 62 day period of the ULX in M82 (X41.4-1-60), the periodicity detected in NGC 5408 X-1 represents the orbital period of the black hole binary containing the ULX. If this is true then the secondary can only be a giant or super giant star.

  20. Adsorption of RuSex (x =1–5) cluster on Se-doped graphene: First principle calculations

    International Nuclear Information System (INIS)

    Üzengi Aktürk, O.; Tomak, M.

    2015-01-01

    Highlights: • Electronic properties of adsorption of RuSe x (x =1–5) cluster on Se-doped graphene are investigated. • It is found that RuSe, RuSe 4 , RuSe 5 adsorbate make substrate metallic. • RuSe 2 makes it half metallic and RuSe 3 makes semiconductor. - Abstract: We have investigated the adsorption of RuSe x (x =1–5) cluster on Se-doped graphene. The change of the adsorption energy with the number of Se atoms and magnetization values are investigated. Electronic properties of adsorption of RuSe x (x =1–5) cluster on Se-doped graphene are investigated. The highest adsorption energy belongs to RuSe adsorbate. The biggest magnetization value belongs to RuSe 2 adsorbate. This adsorbate makes the substrate half metallic. This property is important in electronic device applications. It is observed that substitutional Se atom changes the electronic properties of graphene. This substitution makes graphene metallic. While RuSe, RuSe 4 , RuSe 5 adsorbate make substrate metallic, RuSe 3 makes it semiconducting. Generally, it is found that there is a charge transfer from the substrate to clusters within the Löwdin analysis. This is in line with the charge difference results

  1. P2X2 Dominant Deafness Mutations Have No Negative Effect on Wild-Type Isoform: Implications for Functional Rescue and in Deafness Mechanism

    Directory of Open Access Journals (Sweden)

    Yan Zhu

    2017-11-01

    Full Text Available The P2X2 receptor is an ATP-gated ion channel, assembled by three subunits. Recently, it has been found that heterozygous mutations of P2X2 V60L and G353R can cause autosomal dominant nonsyndromic hearing loss. However, the underlying mechanism remains unclear. The fact that heterozygous mutations cause deafness suggests that the mutations may have dominant-negative effect (DNE on wild-type (WT P2X2 isoforms and/or other partners leading to hearing loss. In this study, the effect of these dominant deafness P2X2 mutations on WT P2X2 was investigated. We found that sole transfection of both V60L and G353R deafness mutants could efficiently target to the plasma membrane, like WT P2X2, but exhibit a significantly reduced response to ATP stimulation. Both mutants reduced the channel conductance, but G353R mutation also altered the voltage dependency. Co-expression with WT P2X2 could restore the response to ATP. As the ratio of WT P2X2 vs. mutants increased, the response to ATP was also increased. Computer modeling confirmed that both V60L and G353R dominant-deafness mutant subunits do not have any negative effect on WT P2X2 subunit, when assembled as a heterotrimer. Improper docking or defective gating is the more likely mechanism for impaired channel function by these P2X2 deafness mutations. These results suggest that P2X2 dominant deafness mutations do not have negative effects on WT P2X2 isoforms, and that adding additional WT P2X2 could rescue the lost channel function caused by the deafness mutations. These P2X2 dominant deafness mutations may have negative-effects on other partners leading to hearing loss.

  2. Determination of rotational temperature of AlO from the B2Σ+–X2Σ+ ...

    Indian Academy of Sciences (India)

    pp. 597–600. Determination of rotational temperature of AlO from the B2Σ+–X2Σ+ system. M M CHAUDHARI1, C T LONDHE2 and S H BEHERE2. 1Maharashtra Mahavidyalaya, Nilanga 413 521, Dist. Latur, India. 2Department of Physics, Dr Babasaheb Ambedkar Marathwada University,. Aurangabad 431 004, India.

  3. A collection of integrable systems of the Toda type in continuous and discrete time, with 2x2 Lax representations

    OpenAIRE

    Suris, Yuri B.

    1997-01-01

    A fairly complete list of Toda-like integrable lattice systems, both in the continuous and discrete time, is given. For each system the Newtonian, Lagrangian and Hamiltonian formulations are presented, as well as the 2x2 Lax representation and r-matrix structure. The material is given in the "no comment" style, in particular, all proofs are omitted.

  4. The atomic structure of the Si(111) (2 root 3x2 root 3)R30 degrees-Sn reconstruction

    DEFF Research Database (Denmark)

    Levermann, A.H.; Howes, P.B.; Edwards, K.A.

    1996-01-01

    We have studied the atomic structure of the (2 root 3x2 root)R30 degrees reconstruction induced by adsorption of about 1.1 monolayers of Sn on Si(lll) using surface X-ray diffraction (SXRD) and scanning tunnelling microscopy (STM). The experimentally obtained structure factors in SXRD...

  5. Theory and X-ray Absorption Spectroscopy for Aluminum Coordination Complexes – Al K-Edge Studies of Charge and Bonding in (BDI)Al, (BDI)AlR2, and (BDI)AlX2 Complexes.

    Science.gov (United States)

    Altman, Alison B; Pemmaraju, C D; Camp, Clément; Arnold, John; Minasian, Stefan G; Prendergast, David; Shuh, David K; Tyliszczak, Tolek

    2015-08-19

    Polarized aluminum K-edge X-ray absorption near edge structure (XANES) spectroscopy and first-principles calculations were used to probe electronic structure in a series of (BDI)Al, (BDI)AlX2, and (BDI)AlR2 coordination compounds (X = F, Cl, I; R = H, Me; BDI = 2,6-diisopropylphenyl-β-diketiminate). Spectral interpretations were guided by examination of the calculated transition energies and polarization-dependent oscillator strengths, which agreed well with the XANES spectroscopy measurements. Pre-edge features were assigned to transitions associated with the Al 3p orbitals involved in metal-ligand bonding. Qualitative trends in Al 1s core energy and valence orbital occupation were established through a systematic comparison of excited states derived from Al 3p orbitals with similar symmetries in a molecular orbital framework. These trends suggested that the higher transition energies observed for (BDI)AlX2 systems with more electronegative X(1-) ligands could be ascribed to a decrease in electron density around the aluminum atom, which causes an increase in the attractive potential of the Al nucleus and concomitant increase in the binding energy of the Al 1s core orbitals. For (BDI)Al and (BDI)AlH2 the experimental Al K-edge XANES spectra and spectra calculated using the eXcited electron and Core-Hole (XCH) approach had nearly identical energies for transitions to final state orbitals of similar composition and symmetry. These results implied that the charge distributions about the aluminum atoms in (BDI)Al and (BDI)AlH2 are similar relative to the (BDI)AlX2 and (BDI)AlMe2 compounds, despite having different formal oxidation states of +1 and +3, respectively. However, (BDI)Al was unique in that it exhibited a low-energy feature that was attributed to transitions into a low-lying p-orbital of b1 symmetry that is localized on Al and orthogonal to the (BDI)Al plane. The presence of this low-energy unoccupied molecular orbital on electron-rich (BDI)Al distinguishes

  6. HUBUNGAN ANTARA SELF REGULATED LEARNING DAN LOCUS OF CONTROL INTERNAL DENGAN KEMATANGAN VOKASIONAL SISWA SMK

    Directory of Open Access Journals (Sweden)

    Lativa Hartiningtyas

    2016-06-01

    Penelitian ini dilaksanakan pada SMK TKJ (Teknik Komputer dan Jaringan se-Kabupaten Tulungagung. Tujuan dari penelitian ini adalah mengetahui hubungan antara self regulated learning dan locus of control internal sebagai variabel bebas (independent dengan kematangan vokasional sebagai variabel terikat (dependent pada siswa SMK. Populasi penelitian ini adalah seluruh siswa kelas XI Paket Keahlian TKJ di Kabupaten Tulungagung yang berjumlah 337 siswa. Teknik sampling yang digunakan dalam penelitian ini adalah proportionate random sampling. Jumlah sampel pada penelitian ini adalah 182 siswa. Penelitian ini menggunakan pendekatan kuantitatif dengan rancangan penelitian deskriptif korelasional. Instrumen yang digunakan berupa angket self regulated learning, locus of control internal, dan kematangan vokasional yang menggunakan skala Likert dengan 4 skala. Analisis data pada penelitian ini menggunakan korelasi product moment untuk mengetahui hubungan antara variabel bebas dengan variabel terikat secara parsial dan analisis regresi ganda untuk mengetahui hubungan secara simultan antara variabel bebas dan variabel terikat. Berdasarkan analisis data dapat diketahui koefisien korelasi antara X1 dengan Y adalah sebesar 0,511 dan koefisien korelasi antara variabel X2 dengan Y adalah sebesar 0,576.

  7. Geologic map of outcrop areas of sedimentary units in the eastern part of the Hailey 1 degree x 2 degrees quadrangle and part of the southern part of the Challis 1 degree x 2 degrees quadrangle, south-central Idaho

    Science.gov (United States)

    Link, P.K.; Mahoney, J.B.; Bruner, D.J.; Batatian, L.D.; Wilson, Eric; Williams, F.J.C.

    1995-01-01

    The paper version of the Geologic map of outcrop areas of sedimentary units in the eastern part of the Hailey 1x2 Quadrangle and part of the southern part of the Challis 1x2 Quadrangle, south-central Idaho was compiled by Paul Link and others in 1995. The plate was compiled on a 1:100,000 scale topographic base map. TechniGraphic System, Inc. of Fort Collins Colorado digitized this map under contract for N.Shock. G.Green edited and prepared the digital version for publication as a GIS database. The digital geologic map database can be queried in many ways to produce a variety of geologic maps.

  8. Einstein A coefficients for rovibronic lines of the A2Π → X2Σ+ and B2Σ+ → X2Σ+ transitions of CaH and CaD

    Science.gov (United States)

    Alavi, S. Fatemeh; Shayesteh, Alireza

    2018-02-01

    Calcium monohydride is an important diatomic molecule appearing in the spectra of sunspots and M dwarfs. We report complete line lists with Einstein A coefficients for the A2Π-X2Σ+ and B2Σ+-X2Σ+ electronic transitions of CaH and CaD radicals. The most recent ab initio transition dipole moments and potential energy curves were used for the calculation of vibronic band intensities, taking the Herman-Wallis effect into account, and the rotational line strengths were calculated using the PGOPHER program of Western. For the A2Π and B2Σ+ excited states of CaH and CaD, new off-diagonal electronic matrix elements were included in the Hamiltonian matrix, and new sets of spectroscopic constants were determined in order to accurately reproduce the line positions and relative intensities of the observed branches in laboratory spectra. For both CaH and CaD isotopologues, Einstein A coefficients were calculated for all possible rovibronic transitions from the v΄ = 0-3 vibrational levels of the A2Π state and the v΄ = 0-2 vibrational levels of the B2Σ+ state to the v″ = 0-4 vibrational levels of the X2Σ+ ground state. The line lists and intensities reported here can be used to accurately determine the amounts of CaH and CaD in stellar environments.

  9. A hard X-ray study of the ultraluminous X-ray source NGC 5204 X-1 with NuSTAR and XMM-Newton

    DEFF Research Database (Denmark)

    Mukherjee, E. S.; Walton, D. J.; Bachetti, M.

    2015-01-01

    We present the results from coordinated X-ray observations of the ultraluminous X-ray source NGC 5204 X-1 performed by the Nuclear Spectroscopic Telescope Array and XMM-Newton in early 2013. These observations provide the first detection of NGC 5204 X-1 above 10 keV, extending the broadband cover...

  10. Broadband X-ray spectra of the ultraluminous x-ray source Holmberg IX X-1 observed with NuSTAR, XMM-Newton, and Suzaku

    DEFF Research Database (Denmark)

    Walton, D. J.; Harrison, F. A.; Grefenstette, B. W.

    2014-01-01

    We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton, and Suzaku in late 2012. These observations provide the first high-quality spectra of Holmberg IX X-1 above 10 keV to date, extending the...

  11. Energy-dependent evolution in IC10 X-1: hard evidence for an extended corona and implications

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, R.; Steiner, J. F.; Prestwich, A. F. [Harvard-Smithsonian Center for Astrophysics (CFA), Cambridge, MA 02138 (United States); Stevens, I. R. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); Clark, J. S.; Kolb, U. C. [The Open University, Milton Keynes (United Kingdom)

    2014-09-10

    We have analyzed a ∼130 ks XMM-Newton observation of the dynamically confirmed black hole + Wolf-Rayet (BH+WR) X-ray binary (XB) IC10 X-1, covering ∼1 orbital cycle. This system experiences periodic intensity dips every ∼35 hr. We find that energy-independent evolution is rejected at a >5σ level. The spectral and timing evolution of IC10 X-1 are best explained by a compact disk blackbody and an extended Comptonized component, where the thermal component is completely absorbed and the Comptonized component is partially covered during the dip. We consider three possibilities for the absorber: cold material in the outer accretion disk, as is well documented for Galactic neutron star (NS) XBs at high inclination; a stream of stellar wind that is enhanced by traveling through the L1 point; and a spherical wind. We estimated the corona radius (r {sub ADC}) for IC10 X-1 from the dip ingress to be ∼10{sup 6} km, assuming absorption from the outer disk, and found it to be consistent with the relation between r {sub ADC} and 1-30 keV luminosity observed in Galactic NS XBs that spans two orders of magnitude. For the other two scenarios, the corona would be larger. Prior BH mass (M {sub BH}) estimates range over 23-38 M {sub ☉}, depending on the inclination and WR mass. For disk absorption, the inclination, i, is likely to be ∼60-80°, with M {sub BH} ∼ 24-41 M {sub ☉}. Alternatively, the L1-enhanced wind requires i ∼ 80°, suggesting ∼24-33 M {sub ☉}. For a spherical absorber, i ∼ 40°, and M {sub BH} ∼ 50-65 M {sub ☉}.

  12. Atomic structure of a stable high-index Ge surface: G2(103)-(4x1)

    DEFF Research Database (Denmark)

    Seehofer, L.; Bunk, O.; Falkenberg, G.

    1997-01-01

    Based on scanning tunneling microscopy and surface X-ray diffraction, we propose a complex structural model for the Ge(103)-(4 x 1) reconstruction. Each unit cell contains two (103) double steps, which gives rise to the formation of stripes of Ge atoms oriented in the [] direction....... The stripes and the spaces between them are covered with threefold-coordinated Ge adatoms. Charge is transferred from the bulk-like edge atoms of the double steps to the adatoms. The formation of the reconstruction can be explained in terms of stress relief, charge transfer, and minimization of the dangling...

  13. Silicene/germanene on MgX2(X = Cl, Br, and I) for Li-ion battery applications

    KAUST Repository

    Zhu, Jiajie

    2016-03-15

    Silicene is a promising electrode material for Li-ion batteries due to its high Li capacity and low Li diffusion barrier. Germanene is expected to show a similar performance due to its analogous structural and electronic properties. However, the performance of both the materials will be determined by the substrate, since freestanding configurations are unstable. We propose Si/MgX2 and Ge/MgX2 (X = Cl, Br, and I) as suitable hybrid structures, based on first-principles calculations. We find that Li will not cluster and that the Li capacity is very high (443 and 279 mA h g-1 for silicene and germanene on MgCl2, respectively). Sandwich structures can be used to further enhance the performance. Low diffusion barriers of less than 0.3 eV are predicted for all the hybrid structures. © The Royal Society of Chemistry 2016.

  14. THE MAGNESIUM ISOTOPOLOGUES OF MgH IN THE A 2Π-X 2Σ+ SYSTEM

    International Nuclear Information System (INIS)

    Hinkle, Kenneth H.; Wallace, Lloyd; Ram, Ram S.; Bernath, Peter F.; Sneden, Christopher; Lucatello, Sara

    2013-01-01

    Using laboratory hollow cathode spectra we have identified lines of the less common magnesium isotopologues of MgH, 25 MgH and 26 MgH, in the A 2 Π-X 2 Σ + system. Based on the previous analysis of 24 MgH, molecular lines have been measured and molecular constants derived for 25 MgH and 26 MgH. Term values and linelists, in both wavenumber and wavelength units, are presented. The A 2 Π-X 2 Σ + system of MgH is important for measuring the magnesium isotope ratios in stars. Examples of analysis using the new linelists to derive the Mg isotope ratio in a metal poor dwarf and giant are shown

  15. Planar Large Core Polymer Optical 1x2 and 1x4 Splitters Connectable to Plastic Optical Fiber

    Directory of Open Access Journals (Sweden)

    V. Prajzler

    2013-09-01

    Full Text Available We report about new approach to design and fabricate multimode 1 x 2 and 1 x 4 Y optical planar power splitter suitable for low-cost short distance optical network. The splitters were designed by beam propagation method using BeamPROP™ software. The dimensions of the splitters were optimized for connecting standard plastic optical fibre with 1 mm diameter. New Norland Optical Adhesives 1625 glues were used as optical waveguide layers and the design structures were completed by CNC engraving on poly(methyl methacrylate substrate. The best parameters that were achieved with 1x2 splitter were insertion loss around 4.1dB at 650 nm and the coupling ratio 52:48; the best one of the 1x4 splitters had at 650 nm insertion loss around 17.6 dB.

  16. Silicene/germanene on MgX2(X = Cl, Br, and I) for Li-ion battery applications

    KAUST Repository

    Zhu, Jiajie; Chroneos, Alexander; Schwingenschlö gl, Udo

    2016-01-01

    Silicene is a promising electrode material for Li-ion batteries due to its high Li capacity and low Li diffusion barrier. Germanene is expected to show a similar performance due to its analogous structural and electronic properties. However, the performance of both the materials will be determined by the substrate, since freestanding configurations are unstable. We propose Si/MgX2 and Ge/MgX2 (X = Cl, Br, and I) as suitable hybrid structures, based on first-principles calculations. We find that Li will not cluster and that the Li capacity is very high (443 and 279 mA h g-1 for silicene and germanene on MgCl2, respectively). Sandwich structures can be used to further enhance the performance. Low diffusion barriers of less than 0.3 eV are predicted for all the hybrid structures. © The Royal Society of Chemistry 2016.

  17. Draft Genome Sequence of Ezakiella peruensis Strain M6.X2, a Human Gut Gram-Positive Anaerobic Coccus.

    Science.gov (United States)

    Diop, Awa; Diop, Khoudia; Tomei, Enora; Raoult, Didier; Fenollar, Florence; Fournier, Pierre-Edouard

    2018-03-01

    We report here the draft genome sequence of Ezakiella peruensis strain M6.X2 T The draft genome is 1,672,788 bp long and harbors 1,589 predicted protein-encoding genes, including 26 antibiotic resistance genes with 1 gene encoding vancomycin resistance. The genome also exhibits 1 clustered regularly interspaced short palindromic repeat region and 333 genes acquired by horizontal gene transfer. Copyright © 2018 Diop et al.

  18. On the simultaneous Pell equations x 2 - (4m 2 - 1)y 2 = y 2 - pz 2 ...

    African Journals Online (AJOL)

    Let m be a positive integer, and let p be an odd prime. By using certain properties of Pell and quartic diophantine equations with some elementary number theory methods, we prove that the system of equations x2 - (4m2 - 1)y2 = 1 and y2 - pz2 = 1 has positive integer solutions (x, y, z) if and only if p ≡ 7(mod 8) and m = 1/4 ...

  19. Stabilization of the O p2x2 phase on Cu(001) sheltered by wrinkled BN over-layer

    Science.gov (United States)

    Kim, Yong-Sung; Ma, Chuanxu; Li, An-Ping; Yoon, Mina

    The 2 √3x √3R45°phase of oxygen (O) on the Cu(001) surface has been observed in scanning tunneling microscopy (STM) measurements. Although the p2x2 phase of O on the Cu(001) surface has been proposed theoretically to be the most stable in O-lean conditions, it has not been observed in experiments for a long time. Recently, the O p2x2 phase has been found in STM on the Cu(001) surface with an overlying BN monolayer. In this theoretical study, we investigate what the role of BN over-layer is to stabilize the O p2x2 phase on the Cu(001) surface. The BN over-layer is lattice-matched with the Cu(001) surface and the BN mono-layer sheet is periodically wrinkled along the BN arm-chair direction and along the [100] or [010] direction on the Cu(001) surface. The interlayer space between the Cu(001) surface and the bulge of the wrinkled BN sheet is found to play as a preferential shelter for O to be adsorbed, and the boundary of the BN inner wall along the [010] or [100] direction makes the p2x2 phase more favorable against the 45°-tilted 2 √3x √3R45°phase of O on the Cu(001) surface. This was supported by Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility, and the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, maaged by UT-Battelle, LLC, for the U. S. DOE.

  20. Monolithically integrated fiber-to-the-home diplexers and triplexers using a bilevel etched 2 x 2 optical coupler.

    Science.gov (United States)

    Zhang, Li; Wang, Lei; He, Jian-Jun

    2009-09-01

    A novel design of monolithically integrated diplexers and triplexers for fiber-to-the-home applications is presented. A bilevel etched asymmetrical 2 x 2 optical coupler is analyzed for efficient couplings of both upstream and downstream signals. The design of the diplexer is extended to a triplexer by adding an etched diffraction grating as an additional downstream demultiplexing element. The total size of the integrated diplexer and triplexer is smaller than 500 microm x 500 microm.

  1. Fermi-level tuning of the Dirac surface state in (Bi1-x Sb x )2Se3 thin films

    Science.gov (United States)

    Satake, Yosuke; Shiogai, Junichi; Takane, Daichi; Yamada, Keiko; Fujiwara, Kohei; Souma, Seigo; Sato, Takafumi; Takahashi, Takashi; Tsukazaki, Atsushi

    2018-02-01

    We report on the electronic states and the transport properties of three-dimensional topological insulator (Bi1-x Sb x )2Se3 ternary alloy thin films grown on an isostructural Bi2Se3 buffer layer on InP substrates. By angle-resolved photoemission spectroscopy, we clearly detected Dirac surface states with a large bulk band gap of 0.2-0.3 eV in the (Bi1-x Sb x )2Se3 film with x  =  0.70. In addition, we observed by Hall effect measurements that the dominant charge carrier converts from electron (n-type) to hole (p-type) at around x  =  0.7, indicating that the Fermi level can be controlled across the Dirac point. Indeed, the carrier transport was shown to be governed by Dirac surface state in 0.63  ⩽  x  ⩽  0.75. These features suggest that Fermi-level tunable (Bi1-x Sb x )2Se3-based heterostructures provide a platform for extracting exotic topological phenomena.

  2. Practical aspects of the use of the X(2) holder for HRTEM-quality TEM sample preparation by FIB.

    Science.gov (United States)

    van Mierlo, Willem; Geiger, Dorin; Robins, Alan; Stumpf, Matthias; Ray, Mary Louise; Fischione, Paul; Kaiser, Ute

    2014-12-01

    The X(2) holder enables the effective production of thin, electron transparent samples for high-resolution transmission electron microscopy (HRTEM). Improvements to the X(2) holder for high-quality transmission electron microscopy (TEM) sample preparation are presented in this paper. We discuss the influence of backscattered electrons (BSE) from the sample holder in determining the lamella thickness in situ and demonstrate that a significant improvement in thickness determination can be achieved by comparatively simple means using the relative BSE intensity. We show (using Monte Carlo simulations) that by taking into account the finite collection angle of the electron backscatter detector, an approximately 20% underestimation of the lamella thickness in a silicon sample can be avoided. However, a correct thickness determination for light-element lamellas still remains a problem with the backscatter method; we introduce a more accurate method using the energy dispersive X-ray spectroscopy (EDX) signal for in situ thickness determination. Finally, we demonstrate how to produce a thin lamella with a nearly damage-free surface using the X(2) holder in combination with sub-kV polishing in the Fischione Instruments׳ NanoMill(®) TEM specimen preparation system. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. SCAT3 changes from baseline and associations with X2 Patch measured head acceleration in amateur Australian football players.

    Science.gov (United States)

    Willmott, Catherine; McIntosh, Andrew S; Howard, Teresa; Mitra, Biswadev; Dimech-Betancourt, Bleydy; Donovan, Jarrod; Rosenfeld, Jeffrey V

    2018-05-01

    To investigate changes from baseline on SCAT3 as a result of football game exposure, and association with X2 Patch measured head acceleration events in amateur Australian footballers. Prospective cohort. Peak linear acceleration (PLA) of the head (>10 g) was measured by wearable head acceleration sensor X2 Biosystems X-Patch in male (n=34) and female (n=19) Australian footballers. SCAT3 was administered at baseline (B) and post-game (PG). 1394 head acceleration events (HEA) >10 g were measured. Mean and median HEA PLA were recorded as 15.2 g (SD=9.2, range=10.0-115.8) and 12.4 g (IQR=11.0-15.6) respectively. No significant difference in median HEA PLA (g) was detected across gender (p=0.55), however, more HEAs were recorded in males (p=0.03). A greater number (p=0.004) and severity (p0.05 for all), was identified for either gender. Increase in symptom severity post game was not associated with X2 measured HEA. Males sustained more HEA, however HEA PLA magnitude did not differ across gender. Further work on the validation of head acceleration sensors is required and their role in sports concussion research and medical management. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  4. Spectral Study of A 1Π–X 1Σ+ Transitions of CO Relevant to Interstellar Clouds

    Science.gov (United States)

    Cheng, Junxia; Zhang, Hong; Cheng, Xinlu

    2018-05-01

    Highly correlated ab initio calculations were performed for an accurate determination of the A 1Π–X 1Σ+ system of the CO molecule. A highly accurate multi-reference configuration interaction approach was used to investigate the potential energy curves (PECs) and the transition dipole moment curve (TDMC). The resultant PECs and TDMC found by using the aug-cc-pV5Z (aV5Z) basis set and 5330 active spaces are in good agreement with the experimental data. Moreover, the Einstein A coefficients, lifetimes, ro-vibrational intensities, absorption oscillator strengths, and integrated cross sections are calculated so that the vibrational bands include v″ = 0–39 \\to v‧ = 0–23. For applications in the atmosphere and interstellar clouds, we studied the transition lineshapes to Gaussian and Lorentzian profiles at different temperatures and pressures. The intensities were calculated at high temperature that was used to satisfy some astrophysical applications, such as in planetary atmospheres. The results are potentially useful for important SAO/NASA Astrophysics Data System and databases such as HITRAN, HITEMP, and the National Institute of Standards and Technology. Because the results from many laboratory techniques and our calculations now agree, analyses of interstellar CO based on absorption from A 1Π–X 1Σ+ are no longer hindered by present spectral parameters.

  5. Hydroxyl group induced adsorption of four-nitro benzoic acid on Si(100) 2x1 surface

    International Nuclear Information System (INIS)

    Ihm, K.; Kang, T.-H.; Hwang, C.C.; Kim, K.-J.; Hwang, H.-N.; Kim, H.-D.; Han, J.H.; Moon, S.; Kim, B.; POSTECH

    2004-01-01

    Full text: A number of studies have been conducted on self-assembled monolayers (SAMs) in order to study the adhesion of polymer films on various substrates. Recently, the studies on SAMs on the semiconductor substrate are more motivated because of their possible application to nanoscale devices. For the electronic and chemical properties suitable for various applications, the aromatic ring has been used as a building block of various molecules forming SAMs. Here, we used four-nitro benzoic acid (4-NBA) as a model planar aromatic compound, in which the phenyl ring, the carboxylic functional group, and NO2 are on the same plane. The adsorption mechanism of 4-NBA on the in-situ prepared OH/Si(100) 2x1 surface was investigated using x-ray photoelectron spectroscopy and near-edge x-ray absorption e structure. The results revealed that the 4-NBA molecule reacts with the hydroxyl group on the Si(100) 2x1 surface through deprotonation of the carboxyl group. The saturation coverage of 4-NBA estimated by the O 1s ratio is 1/2 ML. Additionally, we could observe the desorption of the oxygen atom from the NO2 moiety of the 4-NBA upon irradiating the surface by photons of 500 eV

  6. The reflection component from Cygnus X-1 in the soft state measured by NuSTAR and Suzaku

    Energy Technology Data Exchange (ETDEWEB)

    Tomsick, John A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Nowak, Michael A. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics, Cambridge, MA 02139 (United States); Parker, Michael; Fabian, Andy C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Miller, Jon M.; King, Ashley L. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Harrison, Fiona A.; Forster, Karl; Fürst, Felix; Grefenstette, Brian W.; Madsen, Kristin K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Bachetti, Matteo; Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, F-31400 Toulouse (France); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Natalucci, Lorenzo [Istituto Nazionale di Astrofisica, INAF-IAPS, via del Fosso del Cavaliere, I-00133 Roma (Italy); Pottschmidt, Katja [CRESST and NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States); Ross, Randy R., E-mail: jtomsick@ssl.berkeley.edu [Physics Department, College of the Holy Cross, Worcester, MA 01610 (United States); and others

    2014-01-01

    The black hole binary Cygnus X-1 was observed in late 2012 with the Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku, providing spectral coverage over the ∼1-300 keV range. The source was in the soft state with a multi-temperature blackbody, power law, and reflection components along with absorption from highly ionized material in the system. The high throughput of NuSTAR allows for a very high quality measurement of the complex iron line region as well as the rest of the reflection component. The iron line is clearly broadened and is well described by a relativistic blurring model, providing an opportunity to constrain the black hole spin. Although the spin constraint depends somewhat on which continuum model is used, we obtain a {sub *} > 0.83 for all models that provide a good description of the spectrum. However, none of our spectral fits give a disk inclination that is consistent with the most recently reported binary values for Cyg X-1. This may indicate that there is a >13° misalignment between the orbital plane and the inner accretion disk (i.e., a warped accretion disk) or that there is missing physics in the spectral models.

  7. On the Composition and Neutrix Composition of the Delta Function and the Function cosh^{-1}(|x|^{1/r}+1

    Directory of Open Access Journals (Sweden)

    Brian Fisher

    2017-03-01

    Full Text Available Let $F$ be a distribution in $\\mathcal{D'}$ and let $f$ be a locally summable function. The composition $F(f(x$ of $F$ and $f$ is said to exist and be equal to the distribution $h(x$ if the limit of the sequence $\\{ F_{n}(f(x\\}$ is equal to $h(x$, where $F_n(x =F(x*\\delta _n(x$ for $n=1,2, \\ldots$ and $\\{\\delta_n(x\\}$ is a certain regular sequence converging to the Dirac delta function. It is proved that the neutrix composition $ \\delta^{(s}[\\cosh^{-1} (x_+^{1/r}+1] $ exists and \\beqa \\delta^{(s}[\\cosh^{-1} (x_+^{1/r}+1] = - \\sum _{k=0} ^{M-1} \\sum_{i=0}^{kr+r} {k \\choose i}{(-1^{i+k}rc_{r,s,k} \\over (kr+rk!}\\delta ^{(k}(x, for $s =M-1,M, M+1,\\ldots$ and $r=1,2,\\ldots,$ where $$c_{r,s,k}=\\sum _{j=0}^{i} {i \\choose j}{ (-1^{kr+r-i}(2j-i^{s+1}\\over 2^{s+i+1} },$$ $M$ is the smallest integer for which $s-2r+1 < 2Mr$ and $r\\le s/(2M+2.$ Further results are also proved.

  8. THE NuSTAR X-RAY SPECTRUM OF HERCULES X-1: A RADIATION-DOMINATED RADIATIVE SHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, Michael T.; Wood, Kent S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Becker, Peter A. [Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030-4444 (United States); Gottlieb, Amy M.; Marcu-Cheatham, Diana M.; Pottschmidt, Katja [Department of Physics and Center for Space Science and Technology, University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Fürst, Felix [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Hemphill, Paul B. [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0424 (United States); Schwarm, Fritz-Walter; Wilms, Jörn [Dr. Karl-Remeis-Sternwarte and ECAP, Sternwartstr, 7, D-96049 Bamberg (Germany)

    2016-11-10

    We report on new spectral modeling of the accreting X-ray pulsar Hercules X-1. Our radiation-dominated radiative shock model is an implementation of the analytic work of Becker and Wolff on Comptonized accretion flows onto magnetic neutron stars. We obtain a good fit to the spin-phase-averaged 4–78 keV X-ray spectrum observed by the Nuclear Spectroscopic Telescope Array during a main-on phase of the Her X-1 35 day accretion disk precession period. This model allows us to estimate the accretion rate, the Comptonizing temperature of the radiating plasma, the radius of the magnetic polar cap, and the average scattering opacity parameters in the accretion column. This is in contrast to previous phenomenological models that characterized the shape of the X-ray spectrum, but could not determine the physical parameters of the accretion flow. We describe the spectral fitting details and discuss the interpretation of the accretion flow physical parameters.

  9. Spectral and temporal properties of the X-ray pulsar SMC X-1 at hard X-rays

    Science.gov (United States)

    Kunz, M.; Gruber, D. E.; Kendziorra, E .; Kretschmar, P.; Maisack, M.; Mony, B.; Staubert, R.; Doebereiner, S.; Englhauser, J.; Pietsch, W.

    1993-01-01

    The binary X-ray pulsar SMC X- 1 has been observed at hard X-rays with the High Energy X-Ray Experiment (HEXE) on nine occasions between Nov. 1987 and March 1989. A thin thermal bremsstrahlung fit to the phase averaged spectrum yields a plasma temperature (14.4 +/- 1.3) keV and a luminosity above (1.1 +/- 0.1) x 10 exp 38 erg/s in the 20-80 keV band. Pulse period values have been established for three observations, confirming the remarkably stable spin-up trend of SMC X-1. In one of the three observations the pulse profile was seen to deviate from a dominant double pulsation, while at the same time the pulsed fraction was unusually large. For one observation we determined for the first time the pulsed fraction in narrow energy bands. It increases with photon energy from about 20 percent up to over 60 percent in the energy range from 20 to 80 keV.

  10. Investigation on spectroscopic parameters and molecular constants of BeS(X1Σ+) using MRCI theory

    International Nuclear Information System (INIS)

    Liu Hui; Xing Wei; Shi Deheng; Sun Jinfeng

    2012-01-01

    The potential energy curve (PEC) of BeS(X 1 Σ + ) molecule has been studied using MRCI approach with Davidson modification in conjunction with the cc-pV5Z basis set. Effects on the PECs by the core-valence correlation corrections and relativistic effects have been taken into account. The way to consider the relativistic effects is to use the second-order Douglas-Kroll Hamiltonian approximation. With the PEC including the core-valence correlation corrections and relativistic effects, the spectroscopic parameters of BeS(X 1 Σ + ) have been determined. These parameters are compared in detail with those of previous studies reported in the literature, and excellent agreement has been found between the available experimental data and the present ones. With the PEC corrected, the first 40 vibrational states for the non-rotating BeS are computed, and the vibrational level, inertial rotation and centrifugal distortion constants for each vibrational state are predicted. (authors)

  11. Studies of optical pulsations from HZ Herculis/Hercules X-1: A determination of the mass of the neutron star

    International Nuclear Information System (INIS)

    Middleditch, J.; Nelson, J.

    1976-01-01

    In 500 hours of optical observations of this binary system we have repeatedly detected optical pulsations at the 0.1--0.3 percent level. These pulsations are present only for particular well-defined values of the binary and 35-day phases. Position of the pulsation-emitting regions, projected onto the orbital plane, have been measured, and three distinct regions have been resolved. A simple model is put forth which accounts for the observed binary behavior, which gives a direct determination of the mass ratio, M/sub HZHer//M/sub HerX-/ 1 =1.68 +- 0.10 and which establishes that the spin of the pulsar is prograde. Additionally, it is shown that Hz Her fills its Roche lobe. Using the above, the known X-ray eclipse duration, and the mass function, we calculate the orbital inclination to be i=87degree +- 3degree and the masses to be M/sub HerX-/ 1 =1.30 +- 0.14 M/sub sun/ and M/sub HZHer/=2.18 +- 0.11 M/sub sun/

  12. FAST TIMING ANALYSIS OF CYGNUS X-1 USING THE SPECTROMETER ON THE INTERNATIONAL GAMMA-RAY ASTROPHYSICS LABORATORY

    International Nuclear Information System (INIS)

    Cabanac, Clement; Roques, Jean-Pierre; Jourdain, Elisabeth

    2011-01-01

    We report for the first time the high-frequency analysis of Cyg X-1 up to hard X-ray using the spectrometer on International Gamma-Ray Astrophysics Laboratory (INTEGRAL). After analyzing the possible contribution from the background, and using the INTEGRAL archive from 2005 March to 2008 May, power density spectra were obtained up to 130 keV. First, we show that their overall shape is very similar to that observed at lower energies as they are well described by sets of Lorentzians. The strength of this fast variability (up to 40 Hz) does not drop at high energy since we show that it remains at ∼25% rms, even in the highest energy bands. Second, the hard X-ray variability patterns of Cyg X-1 are state dependent: the softer the spectrum (or the lower the hardness ratio), the lower the total fractional variability and the higher the typical frequencies observed. The strength of the total variability as a function of energy and state is then investigated. By comparison with simultaneous and published RXTE/Proportional Counter Array data, we show that in the hard state it remains quite constant in the 2-130 keV energy range. In the softer state it is also flat up to 50 keV and may increase at higher energy. The implications of this behavior on the models are then discussed.

  13. The reflection component from Cygnus X-1 in the soft state measured by NuSTAR and Suzaku

    International Nuclear Information System (INIS)

    Tomsick, John A.; Boggs, Steven E.; Craig, William W.; Nowak, Michael A.; Parker, Michael; Fabian, Andy C.; Miller, Jon M.; King, Ashley L.; Harrison, Fiona A.; Forster, Karl; Fürst, Felix; Grefenstette, Brian W.; Madsen, Kristin K.; Bachetti, Matteo; Barret, Didier; Christensen, Finn E.; Hailey, Charles J.; Natalucci, Lorenzo; Pottschmidt, Katja; Ross, Randy R.

    2014-01-01

    The black hole binary Cygnus X-1 was observed in late 2012 with the Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku, providing spectral coverage over the ∼1-300 keV range. The source was in the soft state with a multi-temperature blackbody, power law, and reflection components along with absorption from highly ionized material in the system. The high throughput of NuSTAR allows for a very high quality measurement of the complex iron line region as well as the rest of the reflection component. The iron line is clearly broadened and is well described by a relativistic blurring model, providing an opportunity to constrain the black hole spin. Although the spin constraint depends somewhat on which continuum model is used, we obtain a * > 0.83 for all models that provide a good description of the spectrum. However, none of our spectral fits give a disk inclination that is consistent with the most recently reported binary values for Cyg X-1. This may indicate that there is a >13° misalignment between the orbital plane and the inner accretion disk (i.e., a warped accretion disk) or that there is missing physics in the spectral models.

  14. NuSTAR AND SUZAKU OBSERVATIONS OF THE HARD STATE IN CYGNUS X-1: LOCATING THE INNER ACCRETION DISK

    International Nuclear Information System (INIS)

    Parker, M. L.; Lohfink, A.; Fabian, A. C.; Alston, W. N.; Kara, E.; Tomsick, J. A.; Boggs, S. E.; Craig, W. W.; Miller, J. M.; Yamaoka, K.; Nowak, M.; Grinberg, V.; Christensen, F. E.; Fürst, F.; Grefenstette, B. W.; Harrison, F. A.; Gandhi, P.; Hailey, C. J.; King, A. L.; Stern, D.

    2015-01-01

    We present simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR ) and Suzaku observations of the X-ray binary Cygnus X-1 in the hard state. This is the first time this state has been observed in Cyg X-1 with NuSTAR, which enables us to study the reflection and broadband spectra in unprecedented detail. We confirm that the iron line cannot be fit with a combination of narrow lines and absorption features, instead requiring a relativistically blurred profile in combination with a narrow line and absorption from the companion wind. We use the reflection models of García et al. to simultaneously measure the black hole spin, disk inner radius, and coronal height in a self-consistent manner. Detailed fits to the iron line profile indicate a high level of relativistic blurring, indicative of reflection from the inner accretion disk. We find a high spin, a small inner disk radius, and a low source height and rule out truncation to greater than three gravitational radii at the 3σ confidence level. In addition, we find that the line profile has not changed greatly in the switch from soft to hard states, and that the differences are consistent with changes in the underlying reflection spectrum rather than the relativistic blurring. We find that the blurring parameters are consistent when fitting either just the iron line or the entire broadband spectrum, which is well modeled with a Comptonized continuum plus reflection model

  15. [Influence and mechanism of PinX1 gene on the chemotherapy sensitivity of nasopharyngeal carcinoma cells in response to Cisplatin].

    Science.gov (United States)

    Shen, Congxiang; Liu, Yanhui; Wen, Zhong; Yang, Keke; Li, Guanxue; Zhang, Shenhua; Zhang, Xinyu

    2015-06-23

    To explore the influence and mechanism of PinX1 gene on the chemotherapy sensitivity of nasopharyngeal carcinoma cells in response to Cisplatin. Transfected nasopharyngeal carcinoma 5-8F cell lines with pCDH-CMV-PinX1-copGFP vector constructed by lentivirus to generate Lenti-PinX1-5-8F cells containing PinX1 gene, using Lenti-Ctrl-5-8F cell (blank vector without PinX1 gene was used to transfect 5-8F cell lines) and 5-8F cell as controls. Expression of PinX1 gene, telomerase activity, the inhibition of cancer cells proliferation, combined anticancer effect with Cisplatin and the expression of lung resistance protein (LRP) and Bcl-2 were detected with fluorescent quantitation polymerase chain reaction (PCR), flow cytometry, thiazolyl blue (MTT) method, areole test, Western blot and drug sensitivity test, respectively, in four groups (Lenti-PinX1-5-8F cell + Cisplatin, Lenti-PinX1-5-8F cell, Cisplatin and 5-8F cell) so as to explore the influence and mechanism of PinX1 gene on the chemotherapy sensitivity of nasopharyngeal carcinoma cells in response to Cisplatin. The telomerase activity in Lenti-PinX1-5-8F cell (0.146 ± 0.004) was lower than those in the other two control cells (Lenti-Ctrl-5-8F cell: 0.967 ± 0.016, 5-8F cell: 1.000 ± 0.034, both P Cisplatin after lower level telomerase activity induced by PinX1 gene. Proliferation index (PI) (%) in Lenti-PinX1-5-8F cell + Cisplatin (14.39 ± 3.66) was also less than the other groups (Lenti-PinX1-5-8F cell, Cisplatin and 5-8F cell groups, 32.97 ± 3.00, 31.18 ± 4.24 and 47.19 ± 4.19, all P Cisplatin, which may be mediated by the down-regulation of telomerase activity and the inhibition of LRP and Bcl-2 gene in nasopharyngeal carcinoma cells.

  16. Photoluminescence of Eu{sup 2+}-doped CaMgSi{sub 2x}O{sub 6+2x} (1.00{<=}x{<=}1.20) phosphors in UV-VUV region

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhiya [Department of Materials Science, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Wang Yuhua [Department of Materials Science, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China)], E-mail: wyh@lzu.edu.cn

    2008-03-15

    Alkaline-earth silicate phosphors CaMgSi{sub 2x}O{sub 6+2x}:Eu{sup 2+} (1.00{<=}x{<=}1.20) were prepared by traditional solid-state reaction. The phosphors showed an intense blue emission centered around 453 nm, with both 254 and 147 nm excitations. The host absorption below 200 nm in the excitation spectra consisted of two bands around 160 and 190 nm. The band around 160 nm was ascertained to be associated with the SiO{sub 4}-tetrahedra and MgO{sub 6}-polyhedra, and that around 190 nm was due to the CaO{sub 8}-polyhedra or some impurities. The incorporation of excess Si of less than 15% would not lead to formation of impurities and the results indicated that an appropriate Si excess could improve the Photoluminescence (PL) intensity in both ultraviolet (UV) and vacuum ultraviolet (VUV) regions.

  17. Millimeter/submillimeter Spectroscopy of PH2CN ({\\tilde{X}} 1A') and CH3PH2 ({\\tilde{X}} 1A'): Probing the Complexity of Interstellar Phosphorus Chemistry

    Science.gov (United States)

    Halfen, D. T.; Clouthier, D. J.; Ziurys, L. M.

    2014-11-01

    Millimeter/submillimeter spectra of PH2CN ({\\tilde{X}} 1A') and CH3PH2 ({\\tilde{X}} 1A') have been recorded for the first time using direct absorption techniques. This work extends previous measurements of both molecules beyond the 10-50 GHz range. Both species were created in the presence of an AC discharge by the reaction of phosphorus vapor and either cyanogen and hydrogen (PH2CN) or methane (CH3PH2). Twelve rotational transitions of PH2CN were recorded over the region 305-422 GHz for asymmetry components Ka = 0 through 8. For CH3PH2, eight rotational transitions were measured from 210-470 GHz with Ka = 0 through 16; these spectra exhibited greater complexity due to the presence of internal rotation, which splits the Ka = 1, 2, and 3 asymmetry components into A and E states. Combined analyses of the millimeter/submillimeter and previous microwave data were performed for both molecules. For PH2CN, the spectra were fit with a Watson S-reduced asymmetric top Hamiltonian, resulting in more accurate rotational and centrifugal distortion constants. In the case of CH3PH2, an asymmetric top internal-rotation Hamiltonian was employed in the analysis, significantly improving the rotational and torsional parameters over previous microwave estimates. Searches for both molecules were subsequently conducted toward Sgr B2(N), using the 12 m telescope of the Arizona Radio Observatory (ARO). Neither species was identified, with abundance upper limits, relative to H2, of f (PH2CN/H2) PH2/H2) 2 and >200, respectively.

  18. CORONA, JET, AND RELATIVISTIC LINE MODELS FOR SUZAKU/RXTE/CHANDRA-HETG OBSERVATIONS OF THE CYGNUS X-1 HARD STATE

    International Nuclear Information System (INIS)

    Nowak, Michael A.; Trowbridge, Sarah N.; Davis, John E.; Hanke, Manfred; Wilms, Joern; Markoff, Sera B.; Maitra, Dipankar; Tramper, Frank; Pottschmidt, Katja; Coppi, Paolo

    2011-01-01

    Using Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard 'low states'. Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the 'focused wind' from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating (HETG). These latter spectra are crucial for revealing the ionized absorption due to the secondary's focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations and jets. All three models require a soft component that we fit with a low temperature disk spectrum with an inner radius of only a few tens of GM/c 2 . All three models also agree that the known spectral break at 10 keV is not solely due to the presence of reflection, but each gives a different underlying explanation for the augmentation of this break. Thus, whereas all three models require that there is a relativistically broadened Fe line, the strength and inner radius of such a line is dependent upon the specific model, thus making premature line-based estimates of the black hole spin in the Cyg X-1 system. We look at the relativistic line in detail, accounting for the narrow Fe emission and ionized absorption detected by HETG. Although the specific relativistic parameters of the line are continuum dependent, none of the broad line fits allow for an inner disk radius that is >40 GM/c 2 .

  19. An extraordinarily stable catalyst: Pt NPs supported on two-dimensional Ti3C2X2 (X = OH, F) nanosheets for oxygen reduction reaction.

    Science.gov (United States)

    Xie, Xiaohong; Chen, Siguo; Ding, Wei; Nie, Yao; Wei, Zidong

    2013-10-03

    High dispersion Pt nanoparticles supported on 2D Ti3C2X2 (X = OH, F) nanosheets are presented and electro-chemical measurements confirm that the Pt/Ti3C2X2 catalyst shows enhanced durability and improved ORR activity compared with the commercial Pt/C catalyst.

  20. Measurement of the energetics of metal film growth on a semiconductor: Ag/ Si(100)-2x1

    DEFF Research Database (Denmark)

    Starr, D.E.; Ranney, J.T.; Larsen, Jane Hvolbæk

    2001-01-01

    The first direct calorimetric measurements of the energetics of metal film growth on a semiconductor surface are presented. The heat of adsorption of Ag on Si(100)-(2 x 1) at 300 K decreases from similar to 347 to 246 kJ/mol with coverage in the first monolayer (ML) due to overlap of substrate...... strain from nearby Ag islands. It then rises quickly toward the bulk sublimation enthalpy (285 kJ/mol) as 3D particles grow. A wetting layer grows to 1.0 ML, but is metastable above similar to0.55 ML and dewets when kinetics permit. This may be common when adsorbate islands induce a large strain...

  1. Analysis of the dimerized Sb/Si(001)-(2x1) surface by x-ray standing waves

    International Nuclear Information System (INIS)

    Lyman, P.F.; Qian, Y.; Bedzyk, M.J.

    1994-12-01

    X-ray standing wave measurements were undertaken to study the bonding position of Sb adatoms on the Sb-saturated Si(001)-(2x1) surface. Using the (004) and (022) Bragg reflections, the authors find that the Sb atoms form dimers, and that the center of the Sb ad-dimers lies 1.64 angstrom above the bulk-like Si(004) surface atomic plane. These in-plane results are compared to two structural models consisting of dimers whose bonds are parallel to the surface plane and whose centers are either shifted or unshifted (parallel to the dimer bond direction) relative to the underlying substrate planes. The authors thus find two special cases consistent with these data: one with symmetric (unshifted) dimers having a dimer bond length of 2.81 angstrom, and the other with midpoint-shifted dimers, having a bond length of 2.88 angstrom and a lateral shift of 0.21 angstrom

  2. Protic ionic liquids based on the dimeric and oligomeric anions: [(AcO)xH(x-1)]-.

    Science.gov (United States)

    Johansson, K M; Izgorodina, E I; Forsyth, M; MacFarlane, D R; Seddon, K R

    2008-05-28

    We describe a fluidity and conductivity study as a function of composition in N-methylpyrrolidine-acetic acid mixtures. The simple 1 : 1 acid-base mixture appears to form an ionic liquid, but its degree of ionicity is quite low and such liquids are better thought of as poorly dissociated mixtures of acid and base. The composition consisting of 3 moles acetic acid and 1 mole N-methylpyrrolidine is shown to form the highest ionicity mixture in this binary due to the presence of oligomeric anionic species [(AcO)(x)H(x-1)](-) stabilised by hydrogen bonds. These oligomeric species, being weaker bases than the acetate anion, shift the proton transfer equilibrium towards formation of ionic species, thus generating a higher degree of ionicity than is present at the 1 : 1 composition. A Walden plot analysis, thermogravimetric behaviour and proton NMR data, as well as ab initio calculations of the oligomeric species, all support this conclusion.

  3. The crystal structure of a new ternary antimonide: TmCu4-xSb2 (x 1.065)

    International Nuclear Information System (INIS)

    Fedyna, L.O.; Bodak, O.I.; Fedorchuk, A.O.; Tokaychuk, Ya.O.

    2005-01-01

    The crystal structure of the new ternary compound TmCu 4-x Sb 2 (x 1.065) was determined by direct methods from X-ray powder data (diffractometer DRON-3M, Cu Kα-radiation). It crystallizes with the orthorhombic structure type ErFe 4 Ge 2 (low-temperature modification) and is the first representative of this structure type among known antimonides: space group Pnnm, Pearson code oP14-2.13, a = 7.00565(6) A, b = 7.83582(6) A, c = 4.25051(3) A, Z = 2. Investigated structure is an orthorhombically deformed derivative of the ZrFe 4 Si 2 structure type

  4. Control of in-plane orientation of phthalocyanine molecular columns using vicinal Si(001)-(2x1)-H

    International Nuclear Information System (INIS)

    Nakamura, Masakazu; Matsunobe, Takeshi; Tokumoto, Hiroshi

    2001-01-01

    In-plane crystal orientation of copper phthalocyanine (CuPc) films formed by organic molecular-beam epitaxy have been successfully controlled by using vicinal Si(001)-(2x1)-H as a substrate, containing atomic steps of an approximately 4 nm period. A continuous film was grown at 60 degree C and the film thickness ranged between 5 and 8 molecular layers. By observing a frictional force image of the film, 90% of the molecular columns were found to align across the substrate step rows. The preferential orientation is considered to be induced by artificial surface lattices, which result from the striped effective contact area between the rigid CuPc crystals and the stair-like surfaces. The anisotropic optical properties of the film have been also confirmed by polarized reflection measurements. [copyright] 2001 American Institute of Physics

  5. Observational test for the existence of a rotating black hole in Cyg X-1. [Gravitatinal effects, polarization properties

    Energy Technology Data Exchange (ETDEWEB)

    Stark, R F; Connors, P A [Oxford Univ. (UK). Dept. of Astrophysics

    1977-03-31

    It is stated that the degree and plane of linear polarisation of the radiation from Cyg X-1 are being investigated by X-ray satellite experiments. This radiation can be explained as coming from an accretion disk around a black hole, the polarisation of the X-rays being due to electron scattering in the hotter inner regions of the disk. Existing predictions of the polarisation properties, as a function of energy, have been based on a Newtonian approximation, thus neglecting gravitational effects on the rays as they propagate from the surface of the disk to an observer at infinity. Preliminary results are here given of a full general relativistic calculation that shows that gravitational effects completely alter the polarisation properties, and provide a sensitive test of the existence of a black hole. It is found that for a rapidly rotating black hole the general relativistic effects on the polarisation properties are an order of magnitude greater than for a slowly rotating black hole, or for a neutron star. The degree of linear polarisation of the rays as they leave the disk will also differ from the Newtonian value, and gravitational bending of the light will alter the angle at which a ray leaves the surface of the disk. The large general relativistic variation of the polarisation plane with energy is illustrated graphically. The very large general relativistic rotations in the plane of polarisation provide an opportunity for testing the black hole hypothesis for Cyg X-1. In order to observe these effects X-ray satellite experiments will be required with more sensitive polarimetry across a wider energy range than is available at present.

  6. Structure determination of Ga As (110) p (1 x 1) - Sb using scanned-energy photoelectron diffraction

    International Nuclear Information System (INIS)

    Ascolani, H.; Asensio, M.C.; Fritzsche, W.

    1996-01-01

    Photoelectron diffraction (PD) in the scanned-energy mode has proven to be a powerfull tool for structural determination of the first few surface layers. The scanned-energy mode involves the measurement of the intensity of photoelectrons emitted from a core level as a function of the incident photon energy for different emission directions. The atom specificity of PD allows the investigation of the local structure of adsorbed atoms without interference of the substrate. In addition, if a measurable chemical shift exists, this technique is also able to discriminate between atoms of the same species adsorbed in inequivalent sites. The Ga As (110) p (1x1)-Sb (1 ML) surface represents a prototype system to study atom adsorption on III-V semiconductors. The epitaxial continued layer structure (ECLS) is generally accepted as the geometry corresponding to this surface, although some authors have claimed that the p 3 model forms a stable geometry equivalent to the ECLS, and that it provides an equally good description of their experimental results. So far, the conclusions about the atomic structure of this surface had been derived on the basis of indirect methods. This work exploits to the utmost the possibilities of analysis offered by the scanned-energy PD technique, namely, chemical shift analysis and direct inversion. The energy spectrum of Sb-4d photoelectrons emitted from the Ga As (110)-p (1x1) Sb surface has two chemically-shifted components. We have inverted the scanned-energy photoelectron diffraction data corresponding to these two components to obtain the positions of the Ga and As atoms which are nearest neighbors of two inequivalent Sb atoms. Our results contradict various models proposed for this surface and are consistent only with the ECLS. For a more detailed atomic structure determination, the best fit between experiment and multiple-scattering calculations was determined by a trial-and-error procedure. (author)

  7. A Multiwavelength Study of Cygnus X-1: The First Mid-Infrared Spectroscopic Detection of Compact Jets

    Science.gov (United States)

    Rahoui, Farid; Lee, Julia C.; Heinz, Sebastian; Hines, Dean C.; Pottschmidt, Katja; Wilms, Joern

    2011-01-01

    We report on a Spitzer/IRS (mid-infrared), RXTE /PCA+HEXTE (X-ray), and Ryle (radio) simultaneous multi-wavelength study of the micro quasar Cygnus X-I, which aimed at an investigation of the origin of its mid-infrared emission. Compact jets were present in two out of three observations, and we show that they strongly contribute to the mid-infrared continuum. During the first observation, we detect the spectral break - where the transition from the optically thick to the optically thin regime takes place - at about 2.9 x 10(exp 13) Hz. We then show that the jet's optically thin synchrotron emission accounts for the Cygnus X-1's emission beyond 400 keY, although it cannot alone explain its 3-200 keV continuum. A compact jet was also present during the second observation, but we do not detect the break, since it has likely shifted to higher frequencies. In contrast, the compact jet was absent during the last observation, and we show that the 5-30 micron mid-infrared continuum of Cygnus X-I stems from the blue supergiant companion star HD 226868. Indeed, the emission can then be understood as the combination of the photospheric Raleigh-Jeans tail and the bremsstrahlung from the expanding stellar wind. Moreover, the stellar wind is found to be clumpy, with a filling factor f(sub infinity) approx.= 0.09-0.10. Its bremsstrahlung emission is likely anti-correlated to the soft X-ray emission, suggesting an anticorrelation between the mass-loss and mass-accretion rates. Nevertheless, we do not detect any mid-infrared spectroscopic evidence of interaction between the jets and the Cygnus X-1's environment and/or companion star's stellar wind.

  8. Super-eddington accretion in the ultraluminous x-ray source NGC 1313 X-2: An ephemeral feast

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Shan-Shan [Department of Physics, Xiangtan University, Xiangtan 411105 (China); Zhang, Shuang-Nan; Zhao, Hai-Hui, E-mail: wengss@ihep.ac.cn, E-mail: zhangsn@ihep.ac.cn, E-mail: zhaohh@ihep.ac.cn [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2014-01-10

    We investigate the X-ray spectrum, variability, and the surrounding ionized bubble of NGC 1313 X-2 to explore the physics of super-Eddington accretion. Beyond the Eddington luminosity, the accretion disk of NGC 1313 X-2 is truncated at a large radius (∼50 times the innermost stable circular orbit), and displays the similar evolution track with both luminous Galactic black-hole and neutron star X-ray binaries (XRBs). In super-critical accretion, the speed of radiatively driven outflows from the inner disk is mildly relativistic. Such ultra-fast outflows would be overionized and might produce weak Fe K absorption lines, which may be detected by the coming X-ray mission Astro-H. If NGC 1313 X-2 is a massive stellar XRB, the high luminosity indicates that an ephemeral feast is held in the source. That is, the source must be accreting at a hyper-Eddington mass rate to give the super-Eddington emission over ∼10{sup 4}-10{sup 5} yr. The expansion of the surrounding bubble nebula with a velocity of ∼100 km s{sup –1} might indicate that it has existed over ∼10{sup 6} yr and is inflated by the radiatively driven outflows from the transient with a duty cycle of activity of ∼ a few percent. Alternatively, if the surrounding bubble nebula is produced by line-driven winds, less energy is required than the radiatively driven outflow scenario, and the radius of the Strömgren radius agrees with the nebula size. Our results are in favor of the line-driven winds scenario, which can avoid the conflict between the short accretion age and the apparently much longer bubble age inferred from the expansion velocity in the nebula.

  9. Super-eddington accretion in the ultraluminous x-ray source NGC 1313 X-2: An ephemeral feast

    International Nuclear Information System (INIS)

    Weng, Shan-Shan; Zhang, Shuang-Nan; Zhao, Hai-Hui

    2014-01-01

    We investigate the X-ray spectrum, variability, and the surrounding ionized bubble of NGC 1313 X-2 to explore the physics of super-Eddington accretion. Beyond the Eddington luminosity, the accretion disk of NGC 1313 X-2 is truncated at a large radius (∼50 times the innermost stable circular orbit), and displays the similar evolution track with both luminous Galactic black-hole and neutron star X-ray binaries (XRBs). In super-critical accretion, the speed of radiatively driven outflows from the inner disk is mildly relativistic. Such ultra-fast outflows would be overionized and might produce weak Fe K absorption lines, which may be detected by the coming X-ray mission Astro-H. If NGC 1313 X-2 is a massive stellar XRB, the high luminosity indicates that an ephemeral feast is held in the source. That is, the source must be accreting at a hyper-Eddington mass rate to give the super-Eddington emission over ∼10 4 -10 5 yr. The expansion of the surrounding bubble nebula with a velocity of ∼100 km s –1 might indicate that it has existed over ∼10 6 yr and is inflated by the radiatively driven outflows from the transient with a duty cycle of activity of ∼ a few percent. Alternatively, if the surrounding bubble nebula is produced by line-driven winds, less energy is required than the radiatively driven outflow scenario, and the radius of the Strömgren radius agrees with the nebula size. Our results are in favor of the line-driven winds scenario, which can avoid the conflict between the short accretion age and the apparently much longer bubble age inferred from the expansion velocity in the nebula.

  10. Super-Eddington Accretion in the Ultraluminous X-Ray Source NGC 1313 X-2: An Ephemeral Feast

    Science.gov (United States)

    Weng, Shan-Shan; Zhang, Shuang-Nan; Zhao, Hai-Hui

    2014-01-01

    We investigate the X-ray spectrum, variability, and the surrounding ionized bubble of NGC 1313 X-2 to explore the physics of super-Eddington accretion. Beyond the Eddington luminosity, the accretion disk of NGC 1313 X-2 is truncated at a large radius (~50 times the innermost stable circular orbit), and displays the similar evolution track with both luminous Galactic black-hole and neutron star X-ray binaries (XRBs). In super-critical accretion, the speed of radiatively driven outflows from the inner disk is mildly relativistic. Such ultra-fast outflows would be overionized and might produce weak Fe K absorption lines, which may be detected by the coming X-ray mission Astro-H. If NGC 1313 X-2 is a massive stellar XRB, the high luminosity indicates that an ephemeral feast is held in the source. That is, the source must be accreting at a hyper-Eddington mass rate to give the super-Eddington emission over ~104-105 yr. The expansion of the surrounding bubble nebula with a velocity of ~100 km s-1 might indicate that it has existed over ~106 yr and is inflated by the radiatively driven outflows from the transient with a duty cycle of activity of ~ a few percent. Alternatively, if the surrounding bubble nebula is produced by line-driven winds, less energy is required than the radiatively driven outflow scenario, and the radius of the Strömgren radius agrees with the nebula size. Our results are in favor of the line-driven winds scenario, which can avoid the conflict between the short accretion age and the apparently much longer bubble age inferred from the expansion velocity in the nebula.

  11. Ammonia Uptake and Release in the MnX2–NH3 (X = Cl, Br Systems and Structure of the Mn(NH3nX2 (n = 6, 2 Ammines

    Directory of Open Access Journals (Sweden)

    Duncan H. Gregory

    2012-04-01

    Full Text Available Hexa-ammine complexes, Mn(NH36X2 (X = Cl, Br, have been synthesized by ammoniation of the corresponding transition metal halide and characterized by Powder X-ray diffraction (PXRD and Raman spectroscopy. The hexa-ammine complexes are isostructural (Cubic, Fm-3m, Z = 4; a = 10.2742(6 Å and 10.527(1 Å for X = Cl, Br respectively. Temperature programmed desorption (TPD demonstrated that ammonia release from Mn(NH36X2 complexes occurred in three stages corresponding to the release of 4, 1 and 1 NH3 equivalents respectively. The chloride and bromide both exhibit a deammoniation onset temperature below 323 K. The di-ammoniates from the first desorption step were isolated during TPD measurements and their crystal structures determined by Rietveld refinement against PXRD data (X = Cl: orthorhombic Cmmm, a = 8.1991(9 Å, b = 8.2498(7 Å, c = 3.8212(4 Å, Z = 2; X = Br: orthorhombic Pbam, a = 6.0109(5 Å, b = 12.022(1 Å, c = 4.0230(2 Å, Z = 2.

  12. On the studies of thermodynamics properties of fast neutron irradiated (LixK1-x)2SO4 crystals

    Science.gov (United States)

    El-Khatib, A. M.; Kassem, M. E.; Gomaa, N. G.; Mahmoud, S. A.

    The effect of fast neutron irradiation on the thermodynamic properties of (LixK1-x)2SO4, (x = 0.1, 0.2,˙˙˙˙˙˙˙˙0.5) has been studied. The measurements were carried out in the vicinity of phase transition. The study reveals that as the lithium content decreases the first high temperature phase Tc = 705 K disappears, while the second one is shifted to lower temperature. It is observed also that the specific heat, Cp, decreases sharply with neutron integrated fluence φ and increases once more. Both entropy and enthalpy changes increase with the increase of neutron integrated fluence.

  13. Lewiston 1/sup 0/ x 2/sup 0/ NTMS area Maine, New Hampshire, and Vermont: supplemental data report

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J.R.

    1981-08-01

    This data report presents supplemental analytical results for 1168 stream sediment samples that were collected as part of the SRL-NURE reconnaissance in the National Topographic Map Series (NTMS) Lewiston 1/sup 0/ x 2/sup 0/ quadrangle. Results are reported for 23 elements (extractable, U, Ag, As, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, W, Y, and Zn). Analyses are tabulated and displayed graphically on microfiche. Field data and neutron activation analysis (NAA) were open-filed in DPST-80-146-18 (GJBX-14(81)).

  14. OMI/Aura Near UV Aerosol Optical Depth and Single Scattering Albedo Daily L3 Global 1x1 deg Lat/Lon Grid V003

    Data.gov (United States)

    National Aeronautics and Space Administration — The OMI-Aura level-3 daily global gridded (1x1 deg) near-UV Aerosol data product OMAERUVd based on the enhanced algorithm is available from the NASA Goddard Earth...

  15. NuSTAR, XMM-Newton and Suzaku Observations of the Ultraluminous X-Ray Source Holmberg II X-1

    DEFF Research Database (Denmark)

    Walton, D. J.; Middleton, M. J.; Rana, V.

    2015-01-01

    We present the first broadband 0.3-25.0 keV X-ray observations of the bright ultraluminous X-ray source (ULX) Holmberg II X-1, performed by NuSTAR, XMM-Newton, and Suzaku in 2013 September. The NuSTAR data provide the first observations of Holmberg II X-1 above 10 keV and reveal a very steep high...

  16. Approximate Fixed Point Theorems for the Class of Almost S-KKM&#x1D49E; Mappings in Abstract Convex Uniform Spaces

    Directory of Open Access Journals (Sweden)

    Tong-Huei Chang

    2009-01-01

    Full Text Available We use a concept of abstract convexity to define the almost S-KKM&#x1D49E; property, al-S-KKM&#x1D49E;(X,Y family, and almost Φ-spaces. We get some new approximate fixed point theorems and fixed point theorems in almost Φ-spaces. Our results extend some results of other authors.

  17. Statistical methods in epidemiology. VII. An overview of the chi2 test for 2 x 2 contingency table analysis.

    Science.gov (United States)

    Rigby, A S

    2001-11-10

    The odds ratio is an appropriate method of analysis for data in 2 x 2 contingency tables. However, other methods of analysis exist. One such method is based on the chi2 test of goodness-of-fit. Key players in the development of statistical theory include Pearson, Fisher and Yates. Data are presented in the form of 2 x 2 contingency tables and a method of analysis based on the chi2 test is introduced. There are many variations of the basic test statistic, one of which is the chi2 test with Yates' continuity correction. The usefulness (or not) of Yates' continuity correction is discussed. Problems of interpretation when the method is applied to k x m tables are highlighted. Some properties of the chi2 the test are illustrated by taking examples from the author's teaching experiences. Journal editors should be encouraged to give both observed and expected cell frequencies so that better information comes out of the chi2 test statistic.

  18. Evidence of Room Temperature Ferromagnetism Due to Oxygen Vacancies in (In1- x Fe x )2O3 Thin Films

    Science.gov (United States)

    Chakraborty, Deepannita; Munuswamy, Kuppan; Shaik, Kaleemulla; Nasina, Madhusudhana Rao; Dugasani, Sreekantha Reddy; Inturu, Omkaram

    2018-03-01

    Iron substituted indium oxide (In1- x Fe x )2O3 thin films at x = 0.00, 0.03, 0.05 and 0.07 were coated onto Corning 7059 glass substrates using the electron beam evaporation technique followed by annealing at different temperatures. The prepared thin films were subjected to different characterization techniques to study their structural, optical and magnetic properties. The structural properties of the thin films were studied using x-ray diffractometry (XRD). From the XRD results it was found that the films were crystallized in cubic structure, and no change in crystal structure was observed with annealing temperature. No secondary phases related to iron were observed from the XRD profiles. The chemical composition and surface morphology of the films were examined by field emission scanning electron microscope (FE-SEM) attached with energy dispersive analysis of x-ray (EDAX). The valence state of the elements were studied by x-ray photoelectron spectroscopy (XPS) and found that the indium, iron and oxygen were in In+3, Fe+3 and O-2 states. From the data, the band gap of the (In1- x Fe x )2O3 thin films were calculated and it increased with increase of annealing temperature. The magnetic properties of the films were studied at room temperature by vibrating sample magnetometer (VSM). The films exhibited ferromagnetism at room temperature.

  19. Deletion of P2X2 and P2X3 receptor subunits does not alter motility of the mouse colon

    Directory of Open Access Journals (Sweden)

    Matthew DeVries

    2010-03-01

    Full Text Available Purinergic P2X receptors contribute to neurotransmission in the gut. P2X receptors are ligand-gated cation channels that mediate synaptic excitation in subsets of enteric neurons. The present study evaluated colonic motility in vitro and in vivo in wild type (WT and P2X2 and P2X3 subunit knockout (KO mice. The muscarinic receptor agonist, bethanechol (0.3-3 micromolar, caused similar contractions of the longitudinal muscle in colon segments from WT, P2X2 and P2X3 subunit KO mice. Nicotine (1-300 micromolar, acting at neuronal nicotinic receptors, caused similar longitudinal muscle relaxations in colonic segments from WT and P2X2 and P2X3 subunit KO mice. Nicotine-induced relaxations were inhibited by nitro-L-arginine (NLA, 100 micromolar and apamin (0.1 micromolar which block inhibitory neuromuscular transmission. ATP (1-1000 micromolar caused contractions only in the presence of NLA and apamin. ATP-induced contractions were similar in colon segments from WT, P2X2 and P2X3 KO mice. The mouse colon generates spontaneous migrating motor complexes (MMCs in vitro. The MMC frequency was higher in P2X2 KO compared to WT tissues; other parameters of the MMC were similar in colon segments from WT, P2X2 and P2X3 KO mice. 5-Hydroxytryptophan-induced fecal output was similar in WT, P2X2 and P2X3 KO mice. These data indicate that nicotinic receptors are located predominately on inhibitory motor neurons supplying the longitudinal muscle in the mouse colon. P2X2 or P2X3 subunit containing receptors are not localized to motorneurons supplying the longitudinal muscle. Synaptic transmission mediated by P2X2 or P2X3 subunit containing receptors is not required for propulsive motility in the mouse colon.

  20. Sp1/3 and NF-1 mediate basal transcription of the human P2X1 gene in megakaryoblastic MEG-01 cells

    Directory of Open Access Journals (Sweden)

    Ennion Steven J

    2006-03-01

    Full Text Available Abstract Background P2X1 receptors play an important role in platelet function as they can induce shape change, granule centralization and are also involved in thrombus formation. As platelets have no nuclei, the level of P2X1 expression depends on transcriptional regulation in megakaryocytes, the platelet precursor cell. Since nothing is known about the molecular mechanisms regulating megakaryocytic P2X1 expression, this study aimed to identify and functionally characterize the P2X1 core promoter utilized in the human megakaryoblastic cell line MEG-01. Results In order to identify cis-acting elements involved in the transcriptional regulation of P2X1 expression, the ability of 4.7 kb P2X1 upstream sequence to drive luciferase reporter gene expression was tested. Low promoter activity was detected in proliferating MEG-01 cells. This activity increased 20-fold after phorbol-12-myristate-13-acetate (PMA induced differentiation. A transcription start site was detected 365 bp upstream of the start codon by primer extension. Deletion analysis of reporter constructs indicated a core promoter located within the region -68 to +149 bp that contained two Sp1 sites (named Sp1a and Sp1b and an NF-1 site. Individual mutations of Sp1b or NF-1 binding sites severely reduced promoter activity whereas triple mutation of Sp1a, Sp1b and NF-1 sites completely abolished promoter activity in both untreated and PMA treated cells. Sp1/3 and NF-1 proteins were shown to bind their respective sites by EMSA and interaction of Sp1/3, NF-1 and TFIIB with the endogenous P2X1 core promoter in MEG-01 cells was demonstrated by chromatin immunoprecipitation. Alignment of P2X1 genes from human, chimp, rat, mouse and dog revealed consensus Sp1a, Sp1b and NF-1 binding sites in equivalent positions thereby demonstrating evolutionary conservation of these functionally important sites. Conclusion This study has identified and characterized the P2X1 promoter utilized in MEG-01 cells and

  1. Isolation and characterization of the first xylanolytic hyperthermophilic euryarchaeon Thermococcus sp. strain 2319x1 and its unusual multidomain glycosidase

    Directory of Open Access Journals (Sweden)

    Sergey N Gavrilov

    2016-05-01

    Full Text Available Enzymes from (hyperthermophiles Thermozymes offer a great potential for biotechnological applications. Thermophilic adaptation does not only provide stability towards high temperature but is also often accompanied by a higher resistance to other harsh physicochemical conditions, which are also frequently employed in industrial processes, such as the presence of e.g. denaturing agents as well as low or high pH of the medium. In order to find new thermostable, xylan degrading hydrolases with potential for biotechnological application we used an in situ enrichment strategy incubating Hungate tubes with xylan as the energy substrate in a hot vent located in the tidal zone of Kunashir Island (Kuril archipelago. Using this approach a hyperthermophilic euryarchaeon, designated Thermococcus sp. strain 2319x1, growing on xylan as sole energy and carbon source was isolated. The organism grows optimally at 85°C and pH 7.0 on a variety of natural polysaccharides including xylan, carboxymethyl cellulose (CMC, amorphous cellulose (AMC, xyloglucan, and chitin. The protein fraction extracted from the cells surface with Twin 80 exhibited endoxylanase, endoglucanase and xyloglucanase activities. The genome of Thermococcus sp. strain 2319x1 was sequenced and assembled into one circular chromosome. Within the newly sequenced genome, a gene, encoding a novel type of glycosidase (143 kDa with a unique five-domain structure, was identified. It consists of three glycoside hydrolase (GH domains and two carbohydrate-binding modules (CBM with the domain order GH5-12-12-CBM2-2 (N- to C-terminal direction. The full length protein, as well as truncated versions, were heterologously expressed in Escherichia coli and their activity was analyzed. The full length multidomain glycosidase (MDG was able to hydrolyze various polysaccharides, with the highest activity for barley β-glucan (β-1,3/1,4-glucoside, followed by that for carboxymethyl cellulose (β-1,4-glucoside

  2. Photochemistry of xenon-halogen Van der Waals complexes (X2 = Cl2, Br2, I2): evidence for the intermediate states in the (Xe-X2)*→ XeX* + X reaction

    International Nuclear Information System (INIS)

    Boivineau, Michel

    1987-01-01

    This research thesis addresses the reactivity of excited states of xenon-halogen Van der Waals complexes (Cl 2 , Br 2 , I 2 ) submitted to a multi-photonic excitation. The objective of this study is, by means of a specific experimental approach, to highlight the R*+ X 2 *- to better understand the reaction mechanism, and to study the reactivity of rare gas/halogen systems depending on the halogen nature. After having reported a bibliographical study on each studied system, the author describes the experimental system, reports and discusses experimental results obtained on the different complex systems (chlorine-, bromine- or iodine-based). He finally comments a possible and original application of these works in the development of an excimer laser with a new active medium (the rare gas/halogen Van der Waals complex) which would allow a continuous operation and an easy discharge production [fr

  3. Determination of the rate constant for the OH(X2Π) + OH(X2Π) → H2O + O(3P) reaction over the temperature range 295 to 701 K.

    Science.gov (United States)

    Altinay, Gokhan; Macdonald, R Glen

    2014-01-09

    The rate constant for the radical-radical reaction OH(X(2)Π) + OH(X(2)Π) → H2O + O((3)P) has been measured over the temperature and pressure ranges 295-701 K and 2-12 Torr, respectively, in mixtures of CF4, N2O, and H2O. The OH radical was produced by the 193 nm laser photolysis of N2O. The resulting O((1)D) atoms reacted rapidly with H2O to produce the OH radical. The OH radical was detected by high-resolution time-resolved infrared absorption spectroscopy using a single Λ-doublet component of the OH(1,0) P1e/f(4.5) fundamental vibrational transition. A detailed kinetic model was used to determine the reaction rate constant as a function of temperature. These experiments were conducted in a new temperature controlled reaction chamber. The values of the measured rate constants are quite similar to the previous measurements from this laboratory of Bahng and Macdonald (J. Phys. Chem. A 2007 , 111 , 3850 - 3861); however, they cover a much larger temperature range. The results of the present work do not agree with recent measurements of Sangwan and Krasnoperov (J. Phys. Chem. A 2012 , 116 , 11817 - 11822). At 295 K the rate constant of the title reaction was found to be (2.52 ± 0.63) × 10(-12) cm(3) molecule(-1) s(-1), where the uncertainty includes both experimental scatter and an estimate of systematic errors at the 95% confidence limit. Over the temperature range of the experiments, the rate constant can be represented by k1a = 4.79 × 10(-18)T(1.79) exp(879.0/T) cm(3) molecule(-1) s(-1) with a uncertainty of ±24% at the 2σ level, including experimental scatter and systematic error.

  4. Hexagonal perovskites with cationic vacancies. 24. Rhombohedral 9 L stacking polytypes in the systems Ba/sub 3/Wsub(2-x)sup(VI)Msub(x)sup(V)vacantOsub(9-x/2)vacantsub(x/2) with Msup(V) = Nb, Ta

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1980-12-01

    In the system Ba/sub 3/Wsub(2-x)sup(VI)Nbsub(x)sup(V)vacantOsub(9-x/2)vacantsub(x/2) stacking polytypes of rhombohedral 9 L type (sequence (hhc)/sub 3/; space group R-3m) can be prepared with approximately 1/3 <= x <= 2. For x = 2(Ba/sub 3/Nb/sub 2/vacantO/sub 8/vacant) two modifications are formed. In the corresponding Ta system the phase width is reduced to a smaller region with x approximately 1/3.

  5. Detection of Reflection Features in the Neutron Star Low-mass X-Ray Binary Serpens X-1 with NICER

    Science.gov (United States)

    Ludlam, R. M.; Miller, J. M.; Arzoumanian, Z.; Bult, P. M.; Cackett, E. M.; Chakrabarty, D.; Enoto, T.; Fabian, A. C.; Gendreau, K. C.; Guillot, S.; Homan, J.; Jaisawal, G. K.; Keek, L.; La Marr, B.; Malacaria, C.; Markwardt, C. B.; Steiner, J. F.; Strohmayer, T. E.

    2018-05-01

    We present Neutron Star Interior Composition Explorer (NICER) observations of the neutron star (NS) low-mass X-ray binary Serpens X-1 during the early mission phase in 2017. With the high spectral sensitivity and low-energy X-ray passband of NICER, we are able to detect the Fe L line complex in addition to the signature broad, asymmetric Fe K line. We confirm the presence of these lines by comparing the NICER data to archival observations with XMM-Newton/Reflection Grating Spectrometer (RGS) and NuSTAR. Both features originate close to the innermost stable circular orbit (ISCO). When modeling the lines with the relativistic line model RELLINE, we find that the Fe L blend requires an inner disk radius of {1.4}-0.1+0.2 R ISCO and Fe K is at {1.03}-0.03+0.13 R ISCO (errors quoted at 90%). This corresponds to a position of {17.3}-1.2+2.5 km and {12.7}-0.4+1.6 km for a canonical NS mass ({M}NS}=1.4 {M}ȯ ) and dimensionless spin value of a = 0. Additionally, we employ a new version of the RELXILL model tailored for NSs and determine that these features arise from a dense disk and supersolar Fe abundance.

  6. Fabrication of 1m x 1m readout strips panel and quality verification of new set of SFS dielectric material

    International Nuclear Information System (INIS)

    Kumar, A.; Pandey, A.; Sogarwal, Hariom; Marimuthu, N.; Singh, V.; Subrahmanyam, V.S.

    2016-01-01

    India based Neutrino Observatory (INO) is going to use ∼ 30,000 Resistive Plate Chamber (RPC) as an active detector. Resistive Plate chambers are parallel plate fast gaseous detector made up of high resistivity (10"1"2 ohm) of glass or bakelite. Glass plates work as electrodes of positive and negative potential. When a charged particle passes through chamber it ionizes the gas and charge move towards opposite electrodes. The pick-up panels pick these signals. Signals are sent to front end electronics. The characteristic impedance of the strips of the panels should be matched with front end electronics which helps in minimizing the reflected signal. Since INO is an underground laboratory, all material used in it must be fireproof. Since ∼ 60,000 pick-up panels are going to be used in INO hence it should be cheaper also. We recently received a new set of Silicon Fiber Sheets - a dielectric material, of 25 pieces of 1m x 0.5m having thickness 05 mm. We fabricated a set of readout strips panel of dimension 1m x 1m. We will present this work in detail

  7. The high-energy pulsed X-ray spectrum of Hercules X-1 as observed with OSO 8

    Science.gov (United States)

    Maurer, G. S.; Dennis, B. R.; Coe, M. J.; Crannell, C. J.; Dolan, J. F.; Frost, K. J.; Orwig, L. E.; Cutler, E. P.

    1979-01-01

    Hercules X-1 was observed from August 30 to September 10, 1977, by using the high-energy X-ray scintillation spectrometer on board the OSO 8 satellite. The observation, during which the source was monitored continually for nearly an entire ON-state, covered the energy range from 16 to 280 keV. Pulsed-flux measurements as a function of binary orbit and binary phase are presented for energies between 16 and 98 keV. The pulsed flux between 16 and 33 keV exhibited a sharp decrease following the fourth binary orbit and was consistent with zero pulsed flux thereafter. Only weak evidence was found for temporal variation in the pulsed flux between 33 and 98 keV. The pulsed spectrum has been fitted with a power law, a thermal spectrum without features, and a thermal spectrum with a superposed Gaussian centered at 55 keV. The latter fit has the smallest value of chi-square per degree of freedom, and the resulting integrated line intensity is approximately 0.0015 photon/sec per sq cm for a width of 3.1 (+9.1, -2.6) keV. This result, while of low statistical significance, agrees with the value observed by Truemper (1978) during the same ON-state.

  8. The existence of a temperature-driven solid solution in LixFePO4 for 0 <= x <= 1

    Science.gov (United States)

    Delacourt, Charles; Poizot, Philippe; Tarascon, Jean-Marie; Masquelier, Christian

    2005-03-01

    Lithium-ion batteries have revolutionized the powering of portable electronics. Electrode reactions in these electrochemical systems are based on reversible insertion/deinsertion of Li+ ions into the host electrode material with a concomitant addition/removal of electrons into the host. If such batteries are to find a wider market such as the automotive industry, less expensive positive electrode materials will be required, among which LiFePO4 is a leading contender. An intriguing fundamental problem is to understand the fast electrochemical response from the poorly electronic conducting two-phase LiFePO4/FePO4 system. In contrast to the well-documented two-phase nature of this system at room temperature, we give the first experimental evidence of a solid solution LixFePO4 (0 <= x <= 1) at 450 °C, and two new metastable phases at room temperature with Li0.75FePO4 and Li0.5FePO4 composition. These experimental findings challenge theorists to improve predictive models commonly used in the field. Our results may also lead to improved performances of these electrodes at elevated temperatures.

  9. Study of structure and potential energy curve for ground state X1Σ+ of LaF

    International Nuclear Information System (INIS)

    Chen Linhong; Shang Rencheng

    2002-01-01

    The equilibrium geometry, harmonic frequency and dissociation energy of the molecule LaF have been calculated on several kinds of computation levels with energy-consistent relativistic effective core potentials and valence basis sets including polarization functions 4f2g and diffuse functions 1s1p1d. The possible electronic state and its reasonable dissociation limit for the ground state of LaF are determined based on Atomic and Molecular Reaction Statics (AMRS). The potential energy curve scan for the ground state X 1 Σ + has been carried out with B3LYP method of density functional theory. Murrell-Sorbie analytic potential energy function and its Dunham expansion around equilibrium position have been also derived with a nonlinear least-square fit. The calculated spectroscopic constants are in good agreement with the experimental results of vibrational spectra. The analytical function obtained here is of great realistic importance due to its use in calculating fine transitional structure of vibrational spectra and the reaction dynamic process between atoms and molecules

  10. Bowen emission from Aquila X-1: evidence for multiple components and constraint on the accretion disc vertical structure

    Science.gov (United States)

    Jiménez-Ibarra, F.; Muñoz-Darias, T.; Wang, L.; Casares, J.; Mata Sánchez, D.; Steeghs, D.; Armas Padilla, M.; Charles, P. A.

    2018-03-01

    We present a detailed spectroscopic study of the optical counterpart of the neutron star X-ray transient Aquila X-1 during its 2011, 2013 and 2016 outbursts. We use 65 intermediate resolution GTC-10.4 m spectra with the aim of detecting irradiation-induced Bowen blend emission from the donor star. While Gaussian fitting does not yield conclusive results, our full phase coverage allows us to exploit Doppler mapping techniques to independently constrain the donor star radial velocity. By using the component N III 4640.64/4641.84 Å, we measure Kem = 102 ± 6 km s-1. This highly significant detection (≳13σ) is fully compatible with the true companion star radial velocity obtained from near-infrared spectroscopy during quiescence. Combining these two velocities we determine, for the first time, the accretion disc opening angle and its associated error from direct spectroscopic measurements and detailed modelling, obtaining α = 15.5 ^{+ 2.5}_{-5} deg. This value is consistent with theoretical work if significant X-ray irradiation is taken into account and is important in the light of recent observations of GX339-4, where discrepant results were obtained between the donor's intrinsic radial velocity and the Bowen-inferred value. We also discuss the limitations of the Bowen technique when complete phase coverage is not available.

  11. Image of the Black Hole, Cygnus X-1, Taken by the High Energy Astronomy Observatory (HEAO)-2

    Science.gov (United States)

    1980-01-01

    This image of the suspected Black Hole, Cygnus X-1, was the first object seen by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. According to the theories to date, one concept of a black hole is a star, perhaps 10 times more massive than the Sun, that has entered the last stages of stelar evolution. There is an explosion triggered by nuclear reactions after which the star's outer shell of lighter elements and gases is blown away into space and the heavier elements in the stellar core begin to collapse upon themselves. Once this collapse begins, the inexorable force of gravity continues to compact the material until it becomes so dense it is squeezed into a mere point and nothing can escape from its extreme gravitational field, not even light. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy.

  12. Editorial 2015/X/2

    Directory of Open Access Journals (Sweden)

    Jana Dlouhá

    2015-09-01

    Full Text Available This new issue brings (together with the reviewed papers that focus on environmentally oriented approaches at all levels of education in several countries of Europe also translated article Convergence Between Science and Environmental Education originally published in Science in 2014. The editorial briefly discusses the starting position of the Czech Republic in the Sustainable Development Goals process.

  13. Value of low-dose 2 X 2 Gy palliative radiotherapy in advanced low-grade non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Ng, M.; Wirth, A.; Ryan, G.; MacManus, M.

    2006-01-01

    Low-dose radiotherapy over the last decade has been reported to provide effective palliation for patients with low-grade non-Hodgkin's lymphoma. In this retrospective case series of 10 patients, we report our early experience using low-dose radiotherapy (usually 2 x2 Gy) for patients with advanced-stage follicular, mucosal associated lymphoid tissue, mantle cell and small lymphocytic lymphomas. Median follow up was 27 weeks. Response rates were high (complete response, 70%; partial response, 20%), the response durable and the toxicity was minimal (no toxicity greater than grade 1). Low-dose irradiation is an effective treatment option for patients with low-grade lymphomas with local symptoms Copyright (2006) Blackwell Publishing Asia Pty Ltd

  14. Design of a 2 x 2 scintillating tile package for the SDC barrel electromagnetic tile/fiber calorimeter

    International Nuclear Information System (INIS)

    Hara, K.; Maekoba, H.; Minato, H.; Miyamoto, Y.; Nakano, I.; Okabe, M.; Seiya, Y.; Takano, T.; Takikawa, K.; Yasuoka, K.

    1996-01-01

    We describe R and D results on optical properties of a scintillating tile/fiber system for the SDC barrel electromagnetic calorimeter. The tile/fiber system uses a wavelength shifting fiber to read out the signal of a scintillating plate (tile) and a clear fiber to transmit the signal to a phototube. In the SDC calorimeter design, four of tile/fiber systems are grouped as a 2 x 2 tile package so that the gap width between and the location of the tiles in the absorber slot can be controlled. Optical properties of the tile package such as the light yield, its uniformity, and cross talk were measured in a test bench with a β-ray source and in a 2-GeV/c π + test beam. The performance as an electromagnetic calorimeter was evaluated by a GEANT simulation using the measured response map. We discuss a method of correction for the calorimeter non-uniformity. (orig.)

  15. A periodic point-based method for the analysis of Nash equilibria in 2 x 2 symmetric quantum games

    International Nuclear Information System (INIS)

    Schneider, David

    2011-01-01

    We present a novel method of looking at Nash equilibria in 2 x 2 quantum games. Our method is based on a mathematical connection between the problem of identifying Nash equilibria in game theory, and the topological problem of the periodic points in nonlinear maps. To adapt our method to the original protocol designed by Eisert et al (1999 Phys. Rev. Lett. 83 3077-80) to study quantum games, we are forced to extend the space of strategies from the initial proposal. We apply our method to the extended strategy space version of the quantum Prisoner's dilemma and find that a new set of Nash equilibria emerge in a natural way. Nash equilibria in this set are optimal as Eisert's solution of the quantum Prisoner's dilemma and include this solution as a limit case.

  16. A periodic point-based method for the analysis of Nash equilibria in 2 x 2 symmetric quantum games

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, David, E-mail: schneide@tandar.cnea.gov.ar [Departamento de Fisica, Comision Nacional de EnergIa Atomica. Av. del Libertador 8250, 1429 Buenos Aires (Argentina)

    2011-03-04

    We present a novel method of looking at Nash equilibria in 2 x 2 quantum games. Our method is based on a mathematical connection between the problem of identifying Nash equilibria in game theory, and the topological problem of the periodic points in nonlinear maps. To adapt our method to the original protocol designed by Eisert et al (1999 Phys. Rev. Lett. 83 3077-80) to study quantum games, we are forced to extend the space of strategies from the initial proposal. We apply our method to the extended strategy space version of the quantum Prisoner's dilemma and find that a new set of Nash equilibria emerge in a natural way. Nash equilibria in this set are optimal as Eisert's solution of the quantum Prisoner's dilemma and include this solution as a limit case.

  17. Determination of the isotopic coefficient for x2N using a dimensional analysis of the Schroedinger equation

    International Nuclear Information System (INIS)

    Pali, R.; Coss, R. de; Mustre de Leon, J.

    1999-01-01

    The adimensionalization of equations which govern the dynamics of a physical system can be very useful when studying the qualitative behavior of any variable involved in those equations. In a dynamic system like a particle moving in an effective potential, the isotopic coefficient measure the degree of anharmonicity of the potential. In general each eigenstate has a different coefficient. In this work, we determined the isotopic coefficients for potentials of the form V(x) ∝ x 2N (N=1,2,3,...) through the adimensionalization process of the Schroedinger equation. We found an analytic expression for the isotopic coefficient which depends only of N but not on the eigenstate. The isotopic coefficient value starts at 1/2 for N=1 (harmonic potential) and gradually converges to 1.0 when N increments. This reflects the fact that the potential is more anharmonic for increasing N. (Author)

  18. Potential energy curves and spectroscopic properties of X2Σ+ and A2Π states of 13C14N

    International Nuclear Information System (INIS)

    Liao Jian-Wen; Yang Chuan-Lu

    2014-01-01

    The potential energy curves (PECs) of X 2 Σ + and A 2 Π states of the CN molecule have been calculated with the multi-reference configuration interaction method and the aug-cc-pwCV5Z basis set. Based on the PECs, all of the vibrational and rotational levels of the 13 C 14 N molecule are obtained by solving the Schrödinger equation of the molecular nuclear motion. The spectroscopic parameters are determined by fitting the Dunham coefficients with the levels. Both the levels and the spectroscopic parameters are in good qualitative agreement with the experimental data available. The analytical potential energy functions are also deduced from the calculated PECs. The present results can provide a helpful reference for future spectroscopy experiments or dynamical calculations of the molecule. (atomic and molecular physics)

  19. Density functional theory calculations of magnetocrystalline anisotropy energies for (Fe(1-x)Co(x))(2)B.

    Science.gov (United States)

    Däne, Markus; Kim, Soo Kyung; Surh, Michael P; Åberg, Daniel; Benedict, Lorin X

    2015-07-08

    We present and discuss density functional theory calculations of magnetic properties of the family of ferromagnetic compounds, (Fe(1-x)Co(x))(2)B, focusing specifically on the magnetocrystalline anisotropy energy (MAE). Using periodic supercells of various sizes (up to 96 atoms), it is shown that the general qualitative features of the composition dependence of the MAE is in agreement with experimental findings, while our predicted magnitudes are larger than those of experiment. We find that the use of small supercells (6 and 12-atom) favors larger MAE values relative to a statistical sample of configurations constructed with 96-atom supercells. The effect of lattice relaxations is shown to be small. Calculations of the Curie temperature for this alloy are also presented.

  20. Lattice parameters and Raman-active phonon modes of β-(AlxGa1−x)2O3

    International Nuclear Information System (INIS)

    Kranert, Christian; Jenderka, Marcus; Lenzner, Jörg; Lorenz, Michael; Wenckstern, Holger von; Schmidt-Grund, Rüdiger; Grundmann, Marius

    2015-01-01

    We present X-ray diffraction and Raman spectroscopy investigations of a (100)-oriented (Al x Ga 1–x ) 2 O 3 thin film on MgO (100) and bulk-like ceramics in dependence on their composition. The thin film grown by pulsed laser deposition has a continuous lateral composition spread allowing to determine precisely the dependence of the phonon mode properties and lattice parameters on the chemical composition. For x < 0.4, we observe the single-phase β-modification. Its lattice parameters and phonon energies depend linearly on the composition. We determined the slopes of these dependencies for the individual lattice parameters and for nine Raman lines, respectively. While the lattice parameters of the ceramics follow Vegard's rule, deviations are observed for the thin film. This deviation has only a small effect on the phonon energies, which show a reasonably good agreement between thin film and ceramics

  1. Triggering Process of the X1.0 Three-ribbon Flare in the Great Active Region NOAA 12192

    Energy Technology Data Exchange (ETDEWEB)

    Bamba, Yumi [Institute of Space and Astronautical Science (ISAS)/Japan Aerospace Exploration Agency (JAXA) 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Inoue, Satoshi; Kusano, Kanya; Shiota, Daikou, E-mail: y-bamba@nagoya-u.jp [Institute for Space-Earth Environmental Research (ISEE)/Nagoya University Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan)

    2017-04-01

    The solar magnetic field in a flare-producing active region (AR) is much more complicated than theoretical models, which assume a very simple magnetic field structure. The X1.0 flare, which occurred in AR 12192 on 2014 October 25, showed a complicated three-ribbon structure. To clarify the trigger process of the flare and to evaluate the applicability of a simple theoretical model, we analyzed the data from Hinode /Solar Optical Telescope and the Solar Dynamics Observatory /Helioseismic and Magnetic Imager, Atmospheric Imaging Assembly. We investigated the spatio-temporal correlation between the magnetic field structures, especially the non-potentiality of the horizontal field, and the bright structures in the solar atmosphere. As a result, we determined that the western side of the positive polarity, which is intruding on a negative polarity region, is the location where the flare was triggered. This is due to the fact that the sign of the magnetic shear in that region was opposite that of the major shear of the AR, and the significant brightenings were observed over the polarity inversion line (PIL) in that region before flare onset. These features are consistent with the recently proposed flare-trigger model that suggests that small reversed shear (RS) magnetic disturbances can trigger solar flares. Moreover, we found that the RS field was located slightly off the flaring PIL, contrary to the theoretical prediction. We discuss the possibility of an extension of the RS model based on an extra numerical simulation. Our result suggests that the RS field has a certain flexibility for displacement from a highly sheared PIL, and that the RS field triggers more flares than we expected.

  2. CONSTRAINTS ON THE NEUTRON STAR AND INNER ACCRETION FLOW IN SERPENS X-1 USING NuSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J. M. [Department of Astronomy, The University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1046 (United States); Parker, M. L.; Fabian, A. C. [Institute of Astronomy, The University of Cambridge, Madingley Road, Cambridge CB3 OHA (United Kingdom); Fuerst, F.; Grefenstette, B. W.; Tendulkar, S.; Harrison, F. A.; Rana, V. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Bachetti, M.; Barret, D. [Universite de Toulouse, UPS-OMP, Toulouse (France); Boggs, S. E.; Craig, W. W.; Tomsick, J. A. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Chakrabarty, D. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 70 Vassar Street, Cambridge, MA 02139 (United States); Christensen, F. E. [Danish Technical University, Lyngby (Denmark); Hailey, C. J.; Paerels, F. [Columbia Astrophysics Laboratory and Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Natalucci, L. [Istituto di Astrofisica e Planetologia Spaziali (INAF), Via Fosso del Cavaliere 100, Roma I-00133 (Italy); Stern, D. K. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Zhang, W. W., E-mail: jonmm@umich.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-12-10

    We report on an observation of the neutron star low-mass X-ray binary Serpens X-1, made with NuSTAR. The extraordinary sensitivity afforded by NuSTAR facilitated the detection of a clear, robust, relativistic Fe K emission line from the inner disk. A relativistic profile is required over a single Gaussian line from any charge state of Fe at the 5σ level of confidence, and any two Gaussians of equal width at the same confidence. The Compton back-scattering ''hump'' peaking in the 10-20 keV band is detected for the first time in a neutron star X-ray binary. Fits with relativistically blurred disk reflection models suggest that the disk likely extends close to the innermost stable circular orbit (ISCO) or stellar surface. The best-fit blurred reflection models constrain the gravitational redshift from the stellar surface to be z {sub NS} ≥ 0.16. The data are broadly compatible with the disk extending to the ISCO; in that case, z {sub NS} ≥ 0.22 and R {sub NS} ≤ 12.6 km (assuming M {sub NS} = 1.4 M {sub ☉} and a = 0, where a = cJ/GM {sup 2}). If the star is as large or larger than its ISCO, or if the effective reflecting disk leaks across the ISCO to the surface, the redshift constraints become measurements. We discuss our results in the context of efforts to measure fundamental properties of neutron stars, and models for accretion onto compact objects.

  3. CHROMOSPHERIC EVAPORATION IN AN X1.0 FLARE ON 2014 MARCH 29 OBSERVED WITH IRIS AND EIS

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Qiu, J. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cheng, J. X., E-mail: yingli@nju.edu.cn [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China)

    2015-09-20

    Chromospheric evaporation refers to dynamic mass motions in flare loops as a result of rapid energy deposition in the chromosphere. These motions have been observed as blueshifts in X-ray and extreme-ultraviolet (EUV) spectral lines corresponding to upward motions at a few tens to a few hundreds of km s{sup −1}. Past spectroscopic observations have also revealed a dominant stationary component, in addition to the blueshifted component, in emission lines formed at high temperatures (∼10 MK). This is contradictory to evaporation models predicting predominant blueshifts in hot lines. The recently launched Interface Region Imaging Spectrograph (IRIS) provides high-resolution imaging and spectroscopic observations that focus on the chromosphere and transition region in the UV passband. Using the new IRIS observations, combined with coordinated observations from the EUV Imaging Spectrometer, we study the chromospheric evaporation process from the upper chromosphere to the corona during an X1.0 flare on 2014 March 29. We find evident evaporation signatures, characterized by Doppler shifts and line broadening, at two flare ribbons that are separating from each other, suggesting that chromospheric evaporation takes place in successively formed flaring loops throughout the flare. More importantly, we detect dominant blueshifts in the high-temperature Fe xxi line (∼10 MK), in agreement with theoretical predictions. We also find that, in this flare, gentle evaporation occurs at some locations in the rise phase of the flare, while explosive evaporation is detected at some other locations near the peak of the flare. There is a conversion from gentle to explosive evaporation as the flare evolves.

  4. Hematopoietic Substrate-1-Associated Protein X-1 Regulates the Proliferation and Apoptosis of Endothelial Progenitor Cells Through Akt Pathway Modulation.

    Science.gov (United States)

    Guo, Xin-Bin; Deng, Xin; Wei, Ying

    2018-03-01

    Endothelial precursor cells (EPCs) are involved in vasculogenesis of various physiological and pathological processes. The proliferation and survival mechanism of EPCs needs to be explored further for the purpose of developing an effective glioma treatment. Hematopoietic substrate-1-associated protein X-1 (HAX-1) has been reported as an anti-apoptotic protein that plays an important role in several malignant tumors. However, the effect and mechanism of HAX-1 on EPCs remains unknown. This study aims to investigate the effect of HAX-1 on the proliferation and apoptosis of EPCs and explore its mechanism. According to our results, HAX-1 was overexpressed in EPCs. The results of clone formation and 5-ethynyl-2'-deoxyuridine proliferation assay showed that HAX-1 promoted multiplication of EPCs. Flow cytometry showed HAX-1 knockout cell cycle arrest mainly in G0/G1 phase. Apoptosis analysis showed that HAX-1 could protect EPCs from apoptosis in oxidative stress. Western blot assay indicated that HAX-1 could inhibit the activation of caspase cascade and reduce the expression of p21, Bcl-2-associated X protein, and p53. HAX-1 also enhanced the degradation rate and ubiquitination of p53 through the promotion of phosphorylation of proteins MDM-2 and Akt1. Co-immunoprecipitation and immunofluorescent colocalization assays were performed to test the influence of HAX-1 on the interaction between Akt1 and heat shock protein 90 (Hsp90), which is crucial for the activity of Akt1. In conclusion, this novel study suggests that HAX-1 could facilitate the Akt1 pathway through Hsp90, which led to a decline in the levels of p53, and finally promoted the proliferation and inhibited the apoptosis of EPCs. Stem Cells 2018;36:406-419. © 2017 AlphaMed Press.

  5. LMC X-1: A New Spectral Analysis of the O-star in the Binary and Surrounding Nebula

    Science.gov (United States)

    Hyde, E. A.; Russell, D. M.; Ritter, A.; Filipović, M. D.; Kaper, L.; Grieve, K.; O'Brien, A. N.

    2017-09-01

    We provide new observations of the LMC X-1 O star and its extended nebula structure using spectroscopic data from VLT/UVES as well as Hα imaging from the Wide Field Imager on the Max Planck Gesellschaft/European Southern Observatory 2.2 m telescope and ATCA imaging of the 2.1 GHz radio continuum. This nebula is one of the few known to be energized by an X-ray binary. We use a new spectrum extraction technique that is superior to other methods used to obtain both radial velocities and fluxes. This provides an updated spatial velocity of ≃ 21.0 +/- 4.8 km s-1 for the O star. The slit encompasses both the photo-ionized and shock-ionized regions of the nebula. The imaging shows a clear arc-like structure reminiscent of a wind bow shock in between the ionization cone and shock-ionized nebula. The observed structure can be fit well by the parabolic shape of a wind bow shock. If an interpretation of a wind bow shock system is valid, we investigate the N159-O1 star cluster as a potential parent of the system, suggesting a progenitor mass of ˜60 M ⊙ for the black hole. We further note that the radio emission could be non-thermal emission from the wind bow shock, or synchrotron emission associated with the jet-inflated nebula. For both wind- and jet-powered origins, this would represent one of the first radio detections of such a structure.

  6. OPTICAL PROPERTIES OF THE ULTRALUMINOUS X-RAY SOURCE HOLMBERG IX X-1 AND ITS STELLAR ENVIRONMENT

    International Nuclear Information System (INIS)

    Grise, F.; Kaaret, P.; Pakull, M. W.; Motch, C.

    2011-01-01

    Holmberg IX X-1 is an archetypal ultraluminous X-ray source (ULX). Here we study the properties of the optical counterpart and of its stellar environment using optical data from SUBARU/Faint Object Camera and Spectrograph, GEMINI/GMOS-N and Hubble Space Telescope (HST)/Advanced Camera for Surveys, as well as simultaneous Chandra X-ray data. The V ∼ 22.6 spectroscopically identified optical counterpart is part of a loose cluster with an age ∼ sun . The counterpart is more luminous than the other stars of the association, suggesting a non-negligible optical contribution from the accretion disk. An observed UV excess also points to non-stellar light similar to X-ray active low-mass X-ray binaries. A broad He II λ4686 emission line identified in the optical spectrum of the ULX further suggests optical light from X-ray reprocessing in the accretion disk. Using stellar evolutionary tracks, we have constrained the mass of the counterpart to be ∼> 10 M sun , even if the accretion disk contributes significantly to the optical luminosity. Comparison of the photometric properties of the counterpart with binary models show that the donor may be more massive, ∼> 25 M sun , with the ULX system likely undergoing case AB mass transfer. Finally, the counterpart exhibits photometric variability of 0.14 mag between two HST observations separated by 50 days which could be due to ellipsoidal variations and/or disk reprocessing of variable X-ray emission.

  7. DATA-DRIVEN RADIATIVE HYDRODYNAMIC MODELING OF THE 2014 MARCH 29 X1.0 SOLAR FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Fatima Rubio da; Petrosian, Vahé [Department of Physics, Stanford University, Stanford, CA 94305 (United States); Kleint, Lucia [University of Applied Sciences and Arts Northwestern Switzerland, 5210 Windisch (Switzerland); Liu, Wei [Bay Area Environmental Research Institute, 625 2nd Street, Suite 209, Petaluma, CA 94952-5159 (United States); Allred, Joel C., E-mail: frubio@stanford.edu [NASA/Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States)

    2016-08-10

    Spectroscopic observations of solar flares provide critical diagnostics of the physical conditions in the flaring atmosphere. Some key features in observed spectra have not yet been accounted for in existing flare models. Here we report a data-driven simulation of the well-observed X1.0 flare on 2014 March 29 that can reconcile some well-known spectral discrepancies. We analyzed spectra of the flaring region from the Interface Region Imaging Spectrograph ( IRIS ) in Mg ii h and k, the Interferometric BIdimensional Spectropolarimeter at the Dunn Solar Telescope (DST/IBIS) in H α 6563 Å and Ca ii 8542 Å, and the Reuven Ramaty High Energy Solar Spectroscope Imager ( RHESSI ) in hard X-rays. We constructed a multithreaded flare loop model and used the electron flux inferred from RHESSI data as the input to the radiative hydrodynamic code RADYN to simulate the atmospheric response. We then synthesized various chromospheric emission lines and compared them with the IRIS and IBIS observations. In general, the synthetic intensities agree with the observed ones, especially near the northern footpoint of the flare. The simulated Mg ii line profile has narrower wings than the observed one. This discrepancy can be reduced by using a higher microturbulent velocity (27 km s{sup −1}) in a narrow chromospheric layer. In addition, we found that an increase of electron density in the upper chromosphere within a narrow height range of ≈800 km below the transition region can turn the simulated Mg ii line core into emission and thus reproduce the single peaked profile, which is a common feature in all IRIS flares.

  8. Structure determination of the Si(001)-(2 x 1)-H reconstruction by surface X-ray diffraction: Weakening of the dimer bond by the addition of hydrogen

    DEFF Research Database (Denmark)

    Lauridsen, E.M.; Baker, J.; Nielsen, M.

    2000-01-01

    The atomic structure of the monohydride Si(001)-(2 x 1)-H reconstruction has been investigated by surface X-ray diffraction. Atomic relaxations down to the eighth layer have been determined. The bond length of the hydrogenated silicon dimers was found to be 2.47 +/- 0.02 Angstrom. which is longer...... than the dimer bond of the clean (2 x 1)-reconstructed Si(001) surface and also 5% longer than the bulk bond length of 2.35 Angstrom. The differences to the (2 x 1) structure of the clean surface are discussed in terms of the elimination of the weak pi-bond character of the dimer bond by the addition...

  9. Experimental and theoretical study of the B(2)2Σ+ → X(1)2Σ+ system in the KSr molecule

    Science.gov (United States)

    Szczepkowski, Jacek; Grochola, Anna; Kowalczyk, Paweł; Dulieu, Olivier; Guérout, Romain; Żuchowski, Piotr S.; Jastrzebski, Włodzimierz

    2018-05-01

    Spectral bands for the B(2)2Σ+ → X(1)2Σ+ electronic transition in the doubly-polar open-shell KSr molecule are recorded at moderate resolution using the thermoluminescence technique. The spectra are simulated using three kinds of advanced electronic structure calculations, allowing for an assessment of their accuracy on one hand, and for the derivation of fundamental spectroscopic constants of the X(1)2Σ+ KSr ground state and the excited electronic state B(2)2Σ+ , on the other hand. These results should facilitate further studies aiming at creating ultracold bosonic or fermionic KSr molecules.

  10. Package-X 2.0: A Mathematica package for the analytic calculation of one-loop integrals

    Science.gov (United States)

    Patel, Hiren H.

    2017-09-01

    This article summarizes new features and enhancements of the first major update of Package-X. Package-X 2.0 can now generate analytic expressions for arbitrarily high rank dimensionally regulated tensor integrals with up to four distinct propagators, each with arbitrary integer weight, near an arbitrary even number of spacetime dimensions, giving UV divergent, IR divergent, and finite parts at (almost) any real-valued kinematic point. Additionally, it can generate multivariable Taylor series expansions of these integrals around any non-singular kinematic point to arbitrary order. All special functions and abbreviations output by Package-X 2.0 support Mathematica's arbitrary precision evaluation capabilities to deal with issues of numerical stability. Finally, tensor algebraic routines of Package-X have been polished and extended to support open fermion chains both on and off shell. The documentation (equivalent to over 100 printed pages) is accessed through Mathematica's Wolfram Documentation Center and contains information on all Package-X symbols, with over 300 basic usage examples, 3 project-scale tutorials, and instructions on linking to FEYNCALC and LOOPTOOLS. Program files doi:http://dx.doi.org/10.17632/yfkwrd4d5t.1 Licensing provisions: CC by 4.0 Programming language: Mathematica (Wolfram Language) Journal reference of previous version: H. H. Patel, Comput. Phys. Commun 197, 276 (2015) Does the new version supersede the previous version?: Yes Summary of revisions: Extension to four point one-loop integrals with higher powers of denominator factors, separate extraction of UV and IR divergent parts, testing for power IR divergences, construction of Taylor series expansions of one-loop integrals, numerical evaluation with arbitrary precision arithmetic, manipulation of fermion chains, improved tensor algebraic routines, and much expanded documentation. Nature of problem: Analytic calculation of one-loop integrals in relativistic quantum field theory. Solution

  11. Expression and Functions of Immediate Early Response Gene X-1 (IEX-1 in Rheumatoid Arthritis Synovial Fibroblasts.

    Directory of Open Access Journals (Sweden)

    Akio Morinobu

    Full Text Available In rheumatoid arthritis (RA, synovial fibroblasts (RA-SFs accumulate in affected joints, where they play roles in inflammation and joint destruction. RA-SFs exhibit tumor-like proliferation and are resistant to apoptosis. Although RA-SF activation is well described, negative regulators of RA-SF activation are unknown. We previously reported that histone deacetylase (HDAC inhibitors facilitate apoptosis in RA-SFs. Here we found that RA-SFs treated with the HDAC inhibitor Trichostatin A (TSA exhibited an upregulation of the immediate early response gene X-1 (IEX-1. IEX-1 has roles in apoptosis sensitivity, cell-cycle progression, and proliferation, and is reported to be involved in immune responses, inflammation, and tumorigenesis, and to have anti-arthritic properties. To investigate IEX-1's role in RA-SFs, we used in vitro-cultured synovial fibroblasts from RA and osteoarthritis (OA patients. We confirmed that TSA upregulated the IEX-1 protein and mRNA expressions in RA-SFs by western blotting and quantitative RT-PCR. Inhibiting HDAC1, 2, and 3 (but not 6 or 8 also upregulated IEX-1. The IEX-1 mRNA levels were higher in RA-SFs than in OA-SFs, and were further upregulated in RA-SFs by the pro-inflammatory cytokines TNFα and IL-1β. The staining of surgical specimens showed that IEX-1 was present in the pannus from affected RA joints. Si-RNA-mediated IEX-1 knockdown upregulated the lipopolysaccharide (LPS-induced expression of TNFα and various chemokine mRNAs, indicating that IEX-1 downregulates TNFα and chemokines. Furthermore, apoptosis analysis showed that IEX-1 knockdown protected RA-SFs from apoptosis induced by TSA or by an anti-Fas mAb, indicating that IEX-1 is pro-apoptotic in RA-SFs. Collectively, our results showed that IEX-1 is induced by TNFα and IL-1β in RA-SFs, in which it suppresses TNFα and chemokine production and induces apoptosis; thus, IEX-1 negatively regulates RA-SF activation. Further investigation of IEX1's functions

  12. Photoelectron diffraction k-space volumes of the c(2x2) Mn/Ni(100) structure

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Denlinger, J.; Chen, X. [Univ. of Wisconsin, Milwaukee, WI (United States)] [and others

    1997-04-01

    Traditionally, x-ray photoelectron diffraction (XPD) studies have either been done by scanning the diffraction angle for fixed kinetic energy (ADPD), or scanning the kinetic energy at fixed exit angle (EDPD). Both of these methods collect subsets of the full diffraction pattern, or volume, which is the intensity of photoemission as a function of momentum direction and magnitude. With the high density available at the Spectromicroscopy Facility (BL 7.0) {open_quotes}ultraESCA{close_quotes} station, the authors are able to completely characterize the photoelectron diffraction patterns of surface structures, up to several hundred electron volts kinetic energy. This large diffraction `volume` can then be analyzed in many ways. The k-space volume contains as a subset the energy dependent photoelectron diffraction spectra along all emission angles. It also contains individual, hemispherical, diffraction patterns at specific kinetic energies. Other `cuts` through the data set are also possible, revealing new ways of viewing photoelectron diffraction data, and potentially new information about the surface structure being studied. In this article the authors report a brief summary of a structural study being done on the c(2x2) Mn/Ni(100) surface alloy. This system is interesting for both structural and magnetic reasons. Magnetically, the Mn/Ni(100) surface alloy exhibits parallel coupling of the Mn and Ni moments, which is opposite to the reported coupling for the bulk, disordered, alloy. Structurally, the Mn atoms are believed to lie well above the surface plane.

  13. Magnetic properties and crystal field effects in TlLnX2 compounds (X=S, Se, Te)

    International Nuclear Information System (INIS)

    Duczmal, M.; Pawlak, L.

    1997-01-01

    Ternary thallium lanthanide chalcogenides TlLnX 2 (X=S, Se or Te) crystallize in the α-NaFeO 2 type of structure (R anti 3m). Each kind of the metal ions, surrounded by the distorted chalcogenide octahedra, forms separate layers. The TlX 6 octahedra are strongly elongated and the LnX 6 octahedra slightly shrunk along the threefold axis. The deformations of the coordination polyhedra and the cell volumes change regularly with the lanthanide ionic radii. The difference between the experimental and the calculated M-X distances increases on going from sulphides to tellurides, as a result of the growing covalent character of the bonds. The crystal field parameters were estimated from the high field magnetization (0-14 T) assuming trigonal distortion of the octahedral symmetry of LnX 6 polyhedra. The second-order crystal field parameters were found to correlate with the deformation of the lanthanide ions' environments. No magnetic transition was observed down to 4.2 K. (orig.)

  14. Millimeter Detection Of AlO (X2Σ+) In The Oxygen-rich Envelope Of VY Canis Majoris

    Science.gov (United States)

    Tenenbaum, Emily D.; Ziurys, L. M.

    2009-05-01

    A new circumstellar molecule, the radical AlO (X 2Σ+), has been detected toward the envelope of the oxygen-rich supergiant star VY Canis Majoris (VY CMa) via three rotational emission lines. The N = 7 → 6 and 6 → 5 features of AlO were observed at 1 mm using the Arizona Radio Observatory Submillimeter Telescope (ARO SMT) and the N = 4 → 3 line was detected at 2 mm using the ARO 12 m dish. All lines exhibit noticeable hyperfine broadening due to the I = 5/2 spin of the aluminum nucleus. Based on simulations of the line profiles, AlO most likely arises from the dust-acceleration zone in the spherical outflow of VY CMa, with a source size of θs 0.5''. Given this source size, the column density of AlO was found to be Ntot 2 × 1015 cm-2 for Trot 230 K, with a fractional abundance, relative to H2, of 10-8. Gas-phase thermodynamic equilibrium chemistry is the likely formation mechanism for AlO in VY CMa, but shocks may disrupt the condensation process into Al2O3, allowing AlO to survive 20 stellar radii. The detection of AlO in VY CMa is additional evidence of an active gas-phase refractory chemistry in oxygen-rich envelopes, and suggests such objects may be fruitful sources for other new oxide identifications.

  15. Influence of γ-radiation doses on the properties of TeOx: (x=2-3) thin film

    International Nuclear Information System (INIS)

    Dewan, Namrata; Sreenivas, K.; Gupta, Vinay

    2007-01-01

    The influence of γ-ray doses (10-50 Gy) on the optical and electrical properties of radio-frequency sputtered tellurium dioxide (TeO x ) thin film was studied. The composition of the as-deposited TeO x films deposited under 25% oxygen and 100% oxygen in the sputtering gas mixture (Ar+O 2 ) was x=2 and 3, respectively. TeO 3 films were found to be highly sensitive to the γ-radiation doses and the value of optical band gap decrease from 4.18 to 3.56 eV with increasing radiation dose from 10 to 50 Gy. Current-voltage characteristics of the films showed an increase in the value of conductivity with increasing radiation doses. Monotonic decrease in the values of dielectric constant for the deposited films with increase in radiation dose was observed. The effect of γ-ray doses on the properties of TeO x film has been correlated with the rearrangement of the bipyramidal structure of amorphous TeO x thin film

  16. Surfactant-induced layered growth in homoepitaxy of Fe on Fe(100)-c(2 x 2)O reconstruction surface

    International Nuclear Information System (INIS)

    Kamiko, Masao; Mizuno, Hiroyuki; Chihaya, Hiroaki; Xu, Junhua; Kojima, Isao; Yamamoto, Ryoichi

    2007-01-01

    In this study, the effects of several surfactants (Pb, Bi, and Ag) on the homoepitaxial growth of Fe(100) were studied and compared. The reflection high-energy electron diffraction measurements clearly reveal that these surfactants enhance the layer-by-layer growth of Fe on an Fe(100)-c(2 x 2)O reconstruction surface. The dependence of growth on the surfactant layer thickness suggests that there exists a suitable amount of surfactant layer that induces a smoother layer-by-layer growth. Comparisons between the atomic force microscopy images reveal that the root-mean-square surface roughness of Fe films mediated by Pb and Bi surfactants are considerably smaller than those of the films mediated by Ag surfactant. The Auger electron spectra show that Pb and Bi segregate at the top of the surface. It has been concluded that Pb and Bi are effective surfactants for enhancing layer-by-layer growth in Fe homoepitaxy. Ag has the same effect, but it is less efficient due to the weak surface segregation of Ag

  17. Electronic response of rare-earth magnetic-refrigeration compounds GdX2 (X = Fe and Co)

    Science.gov (United States)

    Bhatt, Samir; Ahuja, Ushma; Kumar, Kishor; Heda, N. L.

    2018-05-01

    We present the Compton profiles (CPs) of rare-earth-transition metal compounds GdX2 (X = Fe and Co) using 740 GBq 137Cs Compton spectrometer. To compare the experimental momentum densities, we have also computed the CPs, electronic band structure, density of states (DOS) and Mulliken population (MP) using linear combination of atomic orbitals (LCAO) method. Local density and generalized gradient approximations within density functional theory (DFT) along with the hybridization of Hartree-Fock and DFT (B3LYP and PBE0) have been considered under the framework of LCAO scheme. It is seen that the LCAO-B3LYP based momentum densities give a better agreement with the experimental data for both the compounds. The energy bands and DOS for both the spin-up and spin-down states show metallic like character of the reported intermetallic compounds. The localization of 3d electrons of Co and Fe has also been discussed in terms of equally normalized CPs and MP data. Discussion on magnetization using LCAO method is also included.

  18. Topological phase transitions of (BixSb1-x)2Se3 alloys by density functional theory.

    Science.gov (United States)

    Abdalla, L B; Padilha José, E; Schmidt, T M; Miwa, R H; Fazzio, A

    2015-07-01

    We have performed an ab initio total energy investigation of the topological phase transition, and the electronic properties of topologically protected surface states of (BixSb1-x)2Se3 alloys. In order to provide an accurate alloy concentration for the phase transition, we have considered the special quasirandom structures to describe the alloy system. The trivial → topological transition concentration was obtained by (i) the calculation of the band gap closing as a function of Bi concentration (x), and (ii) the calculation of the Z2 topological invariant number. We show that there is a topological phase transition, for x around 0.4, verified for both procedures (i) and (ii). We also show that in the concentration range 0.4 x < 0.7, the alloy does not present any other band at the Fermi level besides the Dirac cone, where the Dirac point is far from the bulk states. This indicates that a possible suppression of the scattering process due to bulk states will occur.

  19. Static lattice distortions and the structure of Au/Si(111)-(5x1): An x-ray-diffraction study

    DEFF Research Database (Denmark)

    Schamper, C.; Moritz, W.; Schulz, H.

    1991-01-01

    perpendicular to the rows. The substrate atoms in the top double layer are shifted up to 1 angstrom from their bulk position. The structure has a disordered 5 x 2 periodicity due to the variation of the interatomic Au-Au distances within a row in the [011BAR] direction. The model is consistent with recent...

  20. TOMS/Nimbus-7 Total Column Ozone Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Nimbus-7 Total Column Ozone Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. The Total Ozone Mapping...

  1. TOMS/Nimbus-7 UV Aerosol Index Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Nimbus-7 UV Aerosol Index Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. The Total Ozone Mapping...

  2. TOMS/Earth Probe UV Reflectivity Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV Reflectivity Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this Level-3...

  3. TOMS/Earth Probe UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this...

  4. TOMS/Nimbus-7 UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Nimbus-7 UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. The Total Ozone Mapping...

  5. TOMS/Earth Probe UV-B Erythemal Local Noon Irradiance Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV-B Erythemal Local Noon Irradiance Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The...

  6. TOMS/Earth Probe Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this...

  7. TOMS/Nimbus-7 UV-B Erythemal Local Noon Irradiance Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Nimbus-7 UV-B Erythemal Local Noon Irradiance Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. The Total Ozone...

  8. Potential energy curves and spectroscopic constants for the X1μ+ and A1μ+ states of the BeH+ Molecule

    International Nuclear Information System (INIS)

    Ornellas, F.R.

    1982-02-01

    Using a 1322-term configuration interaction wavefunction potential energy curves are computed for the ground (X 1 μ + ) and first excited (A 1 μ + ) states of the BeH + molecule. Spectroscopic constants are obtained by means of a Dunham analysis. (Author) [pt

  9. Electric field dependent structural and vibrational properties of the Si(100)-H(2 x 1) surface and its implications for STM induced hydrogen desorption

    DEFF Research Database (Denmark)

    Stokbro, Kurt

    1999-01-01

    We report a first principles study of the structure and the vibrational properties of the Si(100)-H(2 x 1) surface in an electric field. The calculated vibrational parameters are used to model the vibrational modes in the presence of the electric field corresponding to a realistic scanning...

  10. TOMS/Nimbus-7 Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Nimbus-7 Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. The Total Ozone Mapping...

  11. Spin reorientation and magnetic anisotropy in Y2Co17-xCr x (x 1.17-3.0) compounds

    International Nuclear Information System (INIS)

    Fuquan, B.; Tegus, O.; Dagula, W.; Brueck, E.; Boer, F.R. de; Buschow, K.H.J.

    2005-01-01

    Spin reorientation transitions and magnetic anisotropy in Y 2 Co 17-x Cr x (x = 1.17-3.0) compounds have been investigated by means of X-ray diffraction and magnetization measurements. The powder X-ray diffraction patterns show that most samples crystallize as a single phase with the rhombohedral Th 2 Zn 17 -type structure. However, in the compound Y 2 Co 14 Cr 3 the Th 2 Zn 17 phase coexist with the hexagonal Th 2 Ni 17 -type phase. The lattice parameters a and c hardly change and the unit cell volume V increases slightly with increasing Cr content. The X-ray diffraction patterns of the aligned powder of the samples have confirmed that at room temperature the compound with x = 1.17 has planar anisotropy, but the compounds with x = 1.76, 2.34 and 3.00 have uniaxial anisotropy. Spin reorientation phenomena occur in all of the compounds. With increasing Cr content, the Curie temperature, the spin reorientation temperature, the spontaneous magnetization, and the anisotropy constant K 2 of the Y 2 Co 17-x Cr x (x = 1.17-3.0) compounds decrease strongly while the anisotropy constant K 1 increases in the range of x from 1.17 to 2.34 and then decreases in the range of x from 2.34 to 3.00

  12. Upper Limits on Gravitational Waves from Scorpius X-1 from a Model-based Cross-correlation Search in Advanced LIGO Data

    NARCIS (Netherlands)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allen, G.; Allocca, A.; Altin, P. A.; Amato, A.; Ananyeva, A.; Anderson, S. B.; Anderson, W. G.; Antier, S.; Appert, S.; Arai, K.; Araya, M. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; AultONeal, K.; Avila-Alvarez, A.; Babak, S.; Bacon, P.; Bader, M. K. M.; Bae, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Banagiri, S.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bawaj, M.; Bazzan, M.; Becsy, B.; Beer, C.; Bejger, M.; Belahcene, I.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Billman, C. R.; Birch, J.; Birney, R.; Birnholtz, O.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackman, J.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bode, N.; Boer, M.; Bogaert, G.; Bohe, A.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Bustillo, J. Calderon; Callister, T. A.; Calloni, E.; Camp, J. B.; Canepa, M.; Canizares, P.; Cannon, K. C.; Cao, H.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Carney, M. F.; Diaz, J. Casanueva; Casentini, C.; Caudill, S.; Cavaglia, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Baiardi, L. Cerboni; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chatterjee, D.; Chatziioannou, K.; Cheeseboro, B. D.; Chen, H. Y.; Chen, Y.; Cheng, H. -P.; Chincarini, A.; Chiummo, A.; Chmiel, T.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, A. J. K.; Chua, S.; Chung, A. K. W.; Chung, S.; Ciani, G.; Ciolfi, R.; Cirelli, C. E.; Cirone, A.; Clara, F.; Clark, J. A.; Cleva, F.; Cocchieri, C.; Coccia, E.; Cohadon, P. -F.; Colla, A.; Collette, C. G.; Cominsky, L. R.; Constancio, M., Jr.; Conti, L.; Cooper, S. J.; Corban, P.; Corbitt, T. R.; Corley, K. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J. -P.; Countryman, S. T.; Couvares, P.; Covas, P. B.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cullen, T. J.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dasgupta, A.; Da Silva Costa, C. F.; Dattilo, V.; Dave, I.; Davier, M.; Davis, D.; Daw, E. J.; Day, B.; De, S.; Debra, D.; Deelman, E.; Degallaix, J.; De laurentis, M.; Deleglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Devenson, J.; Devine, R. C.; Dhurandhar, S.; Diaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Renzo, F.; Doctor, Z.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Dorrington, I.; Douglas, R.; Alvarez, M. Dovale; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Duncan, J.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H. -B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Eisenstein, R. A.; Essick, R. C.; Etienne, Z. B.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Farinon, S.; Farr, B.; Farr, W. M.; Fauchon-Jones, E. J.; Favata, M.; Fays, M.; Fehrmann, H.; Feicht, J.; Fejer, M. M.; Fernandez-Galiana, A.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fong, H.; Forsyth, P. W. F.; Forsyth, S. S.; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fries, E. M.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H.; Gabel, M.; Gadre, B. U.; Gaebel, S. M.; Gair, J. R.; Galloway, D. K.; Gammaitoni, L.; Ganija, M. R.; Gaonkar, S. G.; Garufi, F.; Gaudio, S.; Gaur, G.; Gayathri, V.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, D.; George, J.; Gergely, L.; Germain, V.; Ghonge, S.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glover, L.; Goetz, E.; Goetz, R.; Gomes, S.; Gonzlez, G.; Castro, J. M. Gonzalez; Gopakumar, A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Gruning, P.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannuksela, O. A.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Haster, C. -J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Henry, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Horst, C.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Intini, G.; Isa, H. N.; Isac, J. -M.; Isi, M.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jimenez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Junker, J.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katolik, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kawabe, K.; Kefelian, F.; Keitel, D.; Kemball, A. J.; Kennedy, R.; Kent, C.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J. C.; Kim, W.; Kim, W. S.; Kim, Y. -M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kirchhoff, R.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koch, P.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Krmer, C.; Kringel, V.; Krishnan, B.; Krolak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kumar, S.; Kuo, L.; Kutynia, A.; Kwang, S.; Lackey, B. D.; Lai, K. H.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, H. W.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Liu, J.; Lo, R. K. L.; Lockerbie, N. A.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Luck, H.; Lumaca, D.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Hernandez, I. Magana; Magana-Sandoval, F.; Zertuche, L. Magaa; Magee, R. M.; Majorana, E.; Maksimovic, I.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marka, S.; Marka, Z.; Markakis, C.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matas, A.; Matichard, F.; Matone, L.; Mavalvala, N.; Mayani, R.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McCuller, L.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Mejuto-Villa, E.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minazzoli, O.; Minenkov, Y.; Ming, J.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muniz, E. A. M.; Murray, P. G.; Napier, K.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Nelemans, G.; Nelson, T. J. N.; Neri, M.; Nery, M.; Neunzert, A.; Newport, J. M.; Newton, G.; Ng, K. K. Y.; Nguyen, T. T.; Nichols, D.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Noack, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ormiston, R.; Ortega, L. F.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, J.; Page, M. A.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pang, B.; Pang, P. T. H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perez, C. J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poggiani, R.; Popolizio, P.; Porter, E. K.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Prrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Ramirez, K. E.; Rapagnani, P.; Raymond, V.; Razzano, M.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Ricker, P. M.; Rieger, S.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romel, C. L.; Romie, J. H.; Rosinska, D.; Ross, M. P.; Rowan, S.; Ruediger, A.; Ruggi, P.; Ryan, K.; Rynge, M.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheuer, J.; Schmidt, E.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schoenbeck, A.; Schoenbeck, A.; Schreiber, E.; Schuette, D.; Schulte, B. W.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Seidel, E.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shaffer, T. J.; Shah, A. A.; Shahriar, M. S.; Shao, L.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, R. J. E.; Smith, R. J. E.; Son, E. J.; Sonnenberg, J. A.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Stratta, G.; Strigin, S. E.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepanczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tapai, M.; Taracchini, A.; Taylor, J. A.; Taylor, R.; Theeg, T.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tonelli, M.; Tornasi, Z.; Torrie, C. I.; Tayra, D.; Travasso, F.; Traylor, G.; Trifiro, D.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tsang, K. W.; Tse, M.; Tso, R.; Tuyenbayev, D.; Ueno, K.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahi, K.; Vahlbruch, H.; Vajente, G.; Valdes, G.; Vallisneri, M.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; Van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Varma, V.; Vass, S.; Vasuth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Vicere, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J. -Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walet, R.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, J. Z.; Wang, M.; Wang, Y. -F.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L. -W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wessel, E. K.; Wessels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Whittle, C.; Williams, D.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Wofford, J.; Wong, K. W. K.; Worden, J.; Wright, J. L.; Wu, D. S.; Wu, G.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, Hang; Yu, Haocun; Yvert, M.; Zanolin, M.; Zelenova, T.; Zendri, J. -P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y. -H.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zweizig, J.; Steeghs, D.; Wang, L.

    2017-01-01

    We present the results of a semicoherent search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1, using data from the first Advanced LIGO observing run. The search method uses details of the modeled, parametrized continuous signal to combine coherently data separated by

  13. Radio emission from the X-ray pulsar Her X-1: a jet launched by a strong magnetic field neutron star?

    Science.gov (United States)

    van den Eijnden, J.; Degenaar, N.; Russell, T. D.; Miller-Jones, J. C. A.; Wijnands, R.; Miller, J. M.; King, A. L.; Rupen, M. P.

    2018-01-01

    Her X-1 is an accreting neutron star (NS) in an intermediate-mass X-ray binary. Like low-mass X-ray binaries (LMXBs), it accretes via Roche lobe overflow, but similar to many high-mass X-ray binaries containing a NS; Her X-1 has a strong magnetic field and slow spin. Here, we present the discovery of radio emission from Her X-1 with the Very Large Array. During the radio observation, the central X-ray source was partially obscured by a warped disc. We measure a radio flux density of 38.7 ± 4.8 μJy at 9 GHz but cannot constrain the spectral shape. We discuss possible origins of the radio emission, and conclude that coherent emission, a stellar wind, shocks and a propeller outflow are all unlikely explanations. A jet, as seen in LMXBs, is consistent with the observed radio properties. We consider the implications of the presence of a jet in Her X-1 on jet formation mechanisms and on the launching of jets by NSs with strong magnetic fields.

  14. Detection of Reflection Features in the Neutron Star Low-mass X-Ray Binary Serpens X-1 with NICER

    DEFF Research Database (Denmark)

    Ludlam, R. M.; Miller, J. M.; Arzoumanian, Z.

    2018-01-01

    We present Neutron Star Interior Composition Explorer (NICER) observations of the neutron star (NS) low-mass X-ray binary Serpens X-1 during the early mission phase in 2017. With the high spectral sensitivity and low-energy X-ray passband of NICER, we are able to detect the Fe L line complex in a...

  15. A study of the atmospherically important reactions between dimethyl selenide (DMSe) and molecular halogens (X2 = Cl2, Br2, and I2) with ab initio calculations.

    Science.gov (United States)

    Rhyman, Lydia; Armata, Nerina; Ramasami, Ponnadurai; Dyke, John M

    2012-06-14

    The atmospherically relevant reactions between dimethyl selenide (DMSe) and the molecular halogens (X(2) = Cl(2), Br(2), and I(2)) have been studied with ab initio calculations at the MP2/aug-cc-pVDZ level of theory. Geometry optimization calculations showed that the reactions proceed from the reagents to the products (CH(3)SeCH(2)X + HX) via three minima, a van der Waals adduct (DMSe:X(2)), a covalently bound intermediate (DMSeX(2)), and a product-like complex (CH(3)SeCH(2)X:HX). The computed potential energy surfaces are used to predict what molecular species are likely to be observed in spectroscopic experiments such as gas-phase photoelectron spectroscopy and infrared matrix isolation spectroscopy. It is concluded that, for the reactions of DMSe with Cl(2) and Br(2), the covalent intermediate should be seen in spectroscopic experiments, whereas, in the DMSe + I(2) reaction, the van der Waals adduct DMSe:I(2) should be observed. Comparison is made with previous related calculations and experiments on dimethyl sulfide (DMS) with molecular halogens. The relevance of the results to atmospheric chemistry is discussed. The DMSeX(2) and DMSe:X(2) intermediates are likely to be reservoirs of molecular halogens in the atmosphere which will lead on photolysis to ozone depletion.

  16. Maternal genetic heritage of Southeastern Europe reveals a new Croatian isolate and a novel, local sub-branching in the x2 haplogroup.

    Science.gov (United States)

    Sarac, Jelena; Sarić, Tena; Auguštin, Dubravka Havaš; Jeran, Nina; Kovačević, Lejla; Cvjetan, Svjetlana; Lewis, Ana Perinić; Metspalu, Ene; Reidla, Maere; Novokmet, Natalija; Vidovič, Maruška; Nevajda, Branimir; Glasnović, Anton; Marjanović, Damir; Missoni, Saša; Villems, Richard; Rudan, Pavao

    2014-05-01

    High mtDNA variation in Southeastern Europe (SEE) is a reflection of the turbulent and complex demographic history of this area, influenced by gene flow from various parts of Eurasia and a long history of intermixing. Our results of 1035 samples (488 from Croatia, 239 from Bosnia and 130 from Herzegovina, reported earlier, and 97 Slovenians and 81 individuals from Žumberak, reported here for the first time) show that the SEE maternal genetic diversity fits within a broader European maternal genetic landscape. The study also shows that the population of Žumberak, located in the continental part of Croatia, developed some unique mtDNA haplotypes and elevated haplogroup frequencies due to distinctive demographic history and can be considered a moderate genetic isolate. We also report seven samples from the Bosnian population and one Herzegovinian sample designated as X2* individuals that could not be assigned to any of its sublineages (X2a'o) according to the existing X2 phylogeny. In an attempt to clarify the phylogeny of our X2 samples, their mitochondrial DNA has been completely sequenced. We suppose that these lineages are signs of local microdifferentiation processes that occurred in the recent demographic past in this area and could possibly be marked as SEE-specific X2 sublineages. © 2014 John Wiley & Sons Ltd/University College London.

  17. Accretion-induced spin-wandering effects on the neutron star in Scorpius X-1: Implications for continuous gravitational wave searches

    Science.gov (United States)

    Mukherjee, Arunava; Messenger, Chris; Riles, Keith

    2018-02-01

    The LIGO's discovery of binary black hole mergers has opened up a new era of transient gravitational wave astronomy. The potential detection of gravitational radiation from another class of astronomical objects, rapidly spinning nonaxisymmetric neutron stars, would constitute a new area of gravitational wave astronomy. Scorpius X-1 (Sco X-1) is one of the most promising sources of continuous gravitational radiation to be detected with present-generation ground-based gravitational wave detectors, such as Advanced LIGO and Advanced Virgo. As the sensitivity of these detectors improve in the coming years, so will power of the search algorithms being used to find gravitational wave signals. Those searches will still require integration over nearly year long observational spans to detect the incredibly weak signals from rotating neutron stars. For low mass X-ray binaries such as Sco X-1 this difficult task is compounded by neutron star "spin wandering" caused by stochastic accretion fluctuations. In this paper, we analyze X-ray data from the R X T E satellite to infer the fluctuating torque on the neutron star in Sco X-1. We then perform a large-scale simulation to quantify the statistical properties of spin-wandering effects on the gravitational wave signal frequency and phase evolution. We find that there are a broad range of expected maximum levels of frequency wandering corresponding to maximum drifts of between 0.3 - 50 μ Hz /sec over a year at 99% confidence. These results can be cast in terms of the maximum allowed length of a coherent signal model neglecting spin-wandering effects as ranging between 5-80 days. This study is designed to guide the development and evaluation of Sco X-1 search algorithms.

  18. Broadband X-ray spectra of the ultraluminous X-ray source Holmberg IX X-1 observed with NuSTAR, XMM-Newton, and Suzaku

    Energy Technology Data Exchange (ETDEWEB)

    Walton, D. J.; Harrison, F. A.; Grefenstette, B. W.; Fuerst, F.; Madsen, K. K.; Rana, V.; Stern, D. [Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Miller, J. M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Bachetti, M.; Barret, D.; Webb, N. [Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Fabian, A. C.; Parker, M. L. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Ptak, A.; Zhang, W. W., E-mail: dwalton@srl.caltech.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-09-20

    We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton, and Suzaku in late 2012. These observations provide the first high-quality spectra of Holmberg IX X-1 above 10 keV to date, extending the X-ray coverage of this remarkable source up to ∼30 keV. Broadband observations were undertaken at two epochs, between which Holmberg IX X-1 exhibited both flux and strong spectral variability, increasing in luminosity from L {sub X} = (1.90 ± 0.03) × 10{sup 40} erg s{sup –1} to L {sub X} = (3.35 ± 0.03) × 10{sup 40} erg s{sup –1}. Neither epoch exhibits a spectrum consistent with emission from the standard low/hard accretion state seen in Galactic black hole binaries, which would have been expected if Holmberg IX X-1 harbors a truly massive black hole accreting at substantially sub-Eddington accretion rates. The NuSTAR data confirm that the curvature observed previously in the 3-10 keV bandpass does represent a true spectral cutoff. During each epoch, the spectrum appears to be dominated by two optically thick thermal components, likely associated with an accretion disk. The spectrum also shows some evidence for a nonthermal tail at the highest energies, which may further support this scenario. The available data allow for either of the two thermal components to dominate the spectral evolution, although both scenarios require highly nonstandard behavior for thermal accretion disk emission.

  19. An Optical and Infrared Time-domain Study of the Supergiant Fast X-Ray Transient Candidate IC 10 X-2

    Science.gov (United States)

    Kwan, Stephanie; Lau, Ryan M.; Jencson, Jacob; Kasliwal, Mansi M.; Boyer, Martha L.; Ofek, Eran; Masci, Frank; Laher, Russ

    2018-03-01

    We present an optical and infrared (IR) study of IC 10 X-2, a high-mass X-ray binary in the galaxy IC 10. Previous optical and X-ray studies suggest that X-2 is a Supergiant Fast X-ray Transient: a large-amplitude (factor of ∼100), short-duration (hours to weeks) X-ray outburst on 2010 May 21. We analyze R- and g-band light curves of X-2 from the intermediate Palomar Transient Factory taken between 2013 July 15 and 2017 February 14 that show high-amplitude (≳1 mag), short-duration (≲8 days) flares and dips (≳0.5 mag). Near-IR spectroscopy of X-2 from Palomar/TripleSpec show He I, Paschen-γ, and Paschen-β emission lines with similar shapes and amplitudes as those of luminous blue variables (LBVs) and LBV candidates (LBVc). Mid-IR colors and magnitudes from Spitzer/Infrared Array Camera photometry of X-2 resemble those of known LBV/LBVcs. We suggest that the stellar companion in X-2 is an LBV/LBVc and discuss possible origins of the optical flares. Dips in the optical light curve are indicative of eclipses from optically thick clumps formed in the winds of the stellar counterpart. Given the constraints on the flare duration (0.02–0.8 days) and the time between flares (15.1 ± 7.8 days), we estimate the clump volume filling factor in the stellar winds, f V , to be 0.01interpret the origin of the optical flares as the accretion of clumps formed in the winds of an LBV/LBVc onto the compact object.

  20. Disk Disruptions and X-ray Intensity Excursions in Cyg X-2, LMC X-3 and Cyg X-3

    Science.gov (United States)

    Boyd, P. T.; Smale, A. P.

    2001-05-01

    The RXTE All Sky Monitor soft X-ray light curves of many X-ray binaries show long-term intensity variations (a.k.a "superorbital periodicities") that have been ascribed to precession of a warped, tilted accretion disk around the X-ray source. We have found that the excursion times between X-ray minima in Cyg X-2 can be characterized as a series of integer multiples of the 9.8 binary orbital period, (as opposed to the previously reported stable 77.7 day single periodicity, or a single modulation whose period changes slowly with time). While the data set is too short for a proper statistical analysis, it is clear that the length of any given intensity excursion cannot be used to predict the next (integer) excursion length in the series. In the black hole candidate system LMC X-3, the excursion times are shown to be related to each other by rational fractions. We find that the long term light curve of the unusual galactic X-ray jet source Cyg X-3 can also be described as a series of intensity excursions related to each other by integer multiples of a fundamental underlying clock. In the latter cases, the clock is apparently not related to the known binary periods. A unified physical model, involving both an inclined accretion disk and a fixed-probability disk disruption mechanism is presented, and compared with three-body scattering results. Each time the disk passes through the orbital plane it experiences a fixed probability P that it will disrupt. This model has testable predictions---the distribution of integers should resemble that of an atomic process with a characteristic half life. Further analysis can support or refute the model, and shed light on what system parameters effectively set the value of P.

  1. TIME DELAYS IN QUASI-PERIODIC PULSATIONS OBSERVED DURING THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15

    Energy Technology Data Exchange (ETDEWEB)

    Dolla, L.; Marque, C.; Seaton, D. B.; Dominique, M.; Berghmans, D.; Cabanas, C.; De Groof, A.; Verdini, A.; West, M. J.; Zhukov, A. N. [Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels (Belgium); Van Doorsselaere, T. [Centrum voor Plasma-Astrofysica, Department of Mathematics, KULeuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Schmutz, W. [Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf (Switzerland); Zender, J., E-mail: dolla@sidc.be [European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands)

    2012-04-10

    We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on timescale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the extreme-ultraviolet (EUV) channels of the Euv SpectroPhotometer (ESP) on board the Solar Dynamic Observatory. The zirconium and aluminum filter channels of the Large Yield Radiometer on board the Project for On-Board Autonomy satellite and the soft X-ray (SXR) channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite, where the channel at 1-8 A leads the 0.5-4 A channel by several seconds. The time lags between the first and last channels is up to Almost-Equal-To 9 s. We identified at least two distinct time intervals during the flare impulsive phase, during which the QPPs were associated with two different sources in the Nobeyama RadioHeliograph at 17 GHz. The radio as well as the hard X-ray channels showed different lags during these two intervals. To our knowledge, this is the first time that time lags are reported between EUV and SXR fluctuations on these timescales. We discuss possible emission mechanisms and interpretations, including flare electron trapping.

  2. EXTINCTION MAP OF THE SMALL MAGELLANIC CLOUD BASED ON THE SIRIUS AND 6X 2MASS POINT SOURCE CATALOGS

    International Nuclear Information System (INIS)

    Dobashi, Kazuhito; Egusa, Fumi; Bernard, Jean-Philippe; Paradis, Deborah; Kawamura, Akiko; Hughes, Annie; Bot, Caroline; Reach, William T.

    2009-01-01

    In this paper, we present the first extinction map of the Small Magellanic Cloud (SMC) constructed using the color excess at near-infrared wavelengths. Using a new technique named X percentile method , which we developed recently to measure the color excess of dark clouds embedded within a star distribution, we have derived an E(J - H) map based on the SIRIUS and 6X Two Micron All Sky Survey (2MASS) star catalogs. Several dark clouds are detected in the map derived from the SIRIUS star catalog, which is deeper than the 6X 2MASS catalog. We have compared the E(J - H) map with a model calculation in order to infer the locations of the clouds along the line of sight, and found that many of them are likely to be located in or elongated toward the far side of the SMC. Most of the dark clouds found in the E(J - H) map have counterparts in the CO clouds detected by Mizuno et al. with the NANTEN telescope. A comparison of the E(J - H) map with the virial mass derived from the CO data indicates that the dust-to-gas ratio in the SMC varies in the range A V /N H = 1-2 x 10 -22 mag H -1 cm 2 with a mean value of ∼1.5 x 10 -22 mag H -1 cm 2 . If the virial mass underestimates the true cloud mass by a factor of ∼2, as recently suggested by Bot et al., the mean value would decrease to ∼8x10 -23 mag H -1 cm 2 , in good agreement with the value reported by Gordon et al., 7.59 x 10 -23 mag H -1 cm 2 .

  3. Ultra high resolution imaging of the human head at 8 tesla: 2K x 2K for Y2K.

    Science.gov (United States)

    Robitaille, P M; Abduljalil, A M; Kangarlu, A

    2000-01-01

    To acquire ultra high resolution MRI images of the human brain at 8 Tesla within a clinically acceptable time frame. Gradient echo images were acquired from the human head of normal subjects using a transverse electromagnetic resonator operating in quadrature and tuned to 340 MHz. In each study, a group of six images was obtained containing a total of 208 MB of unprocessed information. Typical acquisition parameters were as follows: matrix = 2,000 x 2,000, field of view = 20 cm, slice thickness = 2 mm, number of excitations (NEX) = 1, flip angle = 45 degrees, TR = 750 ms, TE = 17 ms, receiver bandwidth = 69.4 kHz. This resulted in a total scan time of 23 minutes, an in-plane resolution of 100 microm, and a pixel volume of 0.02 mm3. The ultra high resolution images acquired in this study represent more than a 50-fold increase in in-plane resolution relative to conventional 256 x 256 images obtained with a 20 cm field of view and a 5 mm slice thickness. Nonetheless, the ultra high resolution images could be acquired both with adequate image quality and signal to noise. They revealed numerous small venous structures throughout the image plane and provided reasonable delineation between gray and white matter. The elevated signal-to-noise ratio observed in ultra high field magnetic resonance imaging can be utilized to acquire images with a level of resolution approaching the histological level under in vivo conditions. However, brain motion is likely to degrade the useful resolution. This situation may be remedied in part with cardiac gating. Nonetheless, these images represent a significant advance in our ability to examine small anatomical features with noninvasive imaging methods.

  4. Millimeter Detection of AlO (X 2Σ+): Metal Oxide Chemistry in the Envelope of VY Canis Majoris

    Science.gov (United States)

    Tenenbaum, E. D.; Ziurys, L. M.

    2009-03-01

    A new circumstellar molecule, the radical AlO (X 2Σ+), has been detected toward the envelope of the oxygen-rich supergiant star VY Canis Majoris (VY CMa) using the Arizona Radio Observatory (ARO). The N = 7 → 6 and 6 → 5 rotational transitions of AlO at 268 and 230 GHz were observed at 1 mm using the ARO Submillimeter Telescope (SMT) and the N = 4 → 3 line was detected at 2 mm using the ARO 12 m telescope. Based on the shape of the line profiles, AlO most likely arises from the dust-forming region in the spherical outflow of VY CMa, as opposed to the blue or redshifted winds, with a source size of θ s ~ 0farcs5. Given this source size, the column density of AlO was found to be N tot ~ 2 × 1015 cm-2 for T rot ~ 230 K, with a fractional abundance, relative to H2, of ~10-8. Gas-phase thermodynamic equilibrium chemistry is the likely formation mechanism for AlO in VY CMa, but either shocks disrupt the condensation process into Al2O3, or chemical "freezeout" occurs. The species therefore survives further into the circumstellar envelope to a radius of r ~ 20 R *. The detection of AlO in VY CMa is additional evidence of an active gas-phase refractory chemistry in oxygen-rich envelopes, and suggests such objects may be fruitful sources for other new oxide identifications.

  5. Millimeter Detection of AlO (X^2 Σ ^+): Metal Oxide Chemistry in the Envelope of VY Canis Majoris

    Science.gov (United States)

    Tenenbaum, E. D.; Ziurys, L. M.

    2009-06-01

    A new circumstellar molecule, the radical AlO (X^2 Σ ^+), has been detected toward the envelope of the oxygen-rich supergiant star VY Canis Majoris (VY CMa) using the Arizona Radio Observatory (ARO). The N = 7 → 6 and 6 → 5 rotational transitions of AlO at 268 and 230 GHz were observed at 1 mm using the ARO Submillimeter Telescope (SMT) and the N = 4 → 3 line was detected at 2 mm using the ARO 12 m. Based on the shape of the line profiles, AlO most likely arises from the dust-forming region in the spherical outflow of VY CMa, as opposed to the blue- or red-shifted winds, with a source size of θ_s ˜ 0.5^''. Given this source size, the column density of AlO was found to be N_{tot} ˜ 2 × 10^{15} cm^{-2} for T_{rot} ˜ 230 K, with a fractional abundance, relative to H_2, of ˜ 10^{-8}. Gas-phase thermodynamic equilibrium chemistry is the likely formation mechanism for AlO in VY CMa, but shocks may disrupt the condensation process into Al_2O_3, allowing AlO to survive to a radius of ˜ 20 R_*. The detection of AlO in VY CMa is additional evidence of an active gas-phase refractory chemistry in oxygen-rich envelopes, and suggests such objects may be fruitful sources for other new oxide identifications.

  6. MILLIMETER DETECTION OF AlO (X 2Σ+): METAL OXIDE CHEMISTRY IN THE ENVELOPE OF VY CANIS MAJORIS

    International Nuclear Information System (INIS)

    Tenenbaum, E. D.; Ziurys, L. M.

    2009-01-01

    A new circumstellar molecule, the radical AlO (X 2 Σ + ), has been detected toward the envelope of the oxygen-rich supergiant star VY Canis Majoris (VY CMa) using the Arizona Radio Observatory (ARO). The N = 7 → 6 and 6 → 5 rotational transitions of AlO at 268 and 230 GHz were observed at 1 mm using the ARO Submillimeter Telescope (SMT) and the N = 4 → 3 line was detected at 2 mm using the ARO 12 m telescope. Based on the shape of the line profiles, AlO most likely arises from the dust-forming region in the spherical outflow of VY CMa, as opposed to the blue or redshifted winds, with a source size of θ s ∼ 0.''5. Given this source size, the column density of AlO was found to be N tot ∼ 2 x 10 15 cm -2 for T rot ∼ 230 K, with a fractional abundance, relative to H 2 , of ∼10 -8 . Gas-phase thermodynamic equilibrium chemistry is the likely formation mechanism for AlO in VY CMa, but either shocks disrupt the condensation process into Al 2 O 3 , or chemical 'freezeout' occurs. The species therefore survives further into the circumstellar envelope to a radius of r ∼ 20 R * . The detection of AlO in VY CMa is additional evidence of an active gas-phase refractory chemistry in oxygen-rich envelopes, and suggests such objects may be fruitful sources for other new oxide identifications.

  7. Self-organization in a simple model of adaptive agents playing 2 x 2 games with arbitrary payoff matrices.

    Science.gov (United States)

    Fort, H; Viola, S

    2004-03-01

    We analyze, both analytically and numerically, the self-organization of a system of "selfish" adaptive agents playing an arbitrary iterated pairwise game (defined by a 2 x 2 payoff matrix). Examples of possible games to play are the prisoner's dilemma (PD) game, the chicken game, the hero game, etc. The agents have no memory, use strategies not based on direct reciprocity nor "tags" and are chosen at random, i.e., geographical vicinity is neglected. They can play two possible strategies: cooperate (C) or defect (D). The players measure their success by comparing their utilities with an estimate for the expected benefits and update their strategy following a simple rule. Two versions of the model are studied: (1) the deterministic version (the agents are either in definite states C or D) and (2) the stochastic version (the agents have a probability c of playing C). Using a general master equation we compute the equilibrium states into which the system self-organizes, characterized by their average probability of cooperation c(eq). Depending on the payoff matrix, we show that c(eq) can take five different values. We also consider the mixing of agents using two different payoff matrices and show that any value of c(eq) can be reached by tuning the proportions of agents using each payoff matrix. In particular, this can be used as a way to simulate the effect of a fraction d of "antisocial" individuals--incapable of realizing any value to cooperation--on the cooperative regime hold by a population of neutral or "normal" agents.

  8. Bedrock geology and mineral resources of the Knoxville 1° x 2° quadrangle, Tennessee, North Carolina, and South Carolina

    Science.gov (United States)

    Robinson, Gilpin R.; Lesure, Frank G.; Marlowe, J. I.; Foley, Nora K.; Clark, S.H.

    2004-01-01

    The Knoxville 1°x 2° quadrangle spans the Southern Blue Ridge physiographic province at its widest point from eastern Tennessee across western North Carolina to the northwest corner of South Carolina. The quadrangle also contains small parts of the Valley and Ridge province in Tennessee and the Piedmont province in North and South Carolina. Bedrock in the Valley and Ridge consists of unmetamorphosed, folded and thrust-faulted Paleozoic miogeoclinal sedimentary rocks ranging in age from Cambrian to Mississippian. The Blue Ridge is a complex of stacked thrust sheets divided into three parts: (1) a west flank underlain by rocks of the Late Proterozoic and Early Cambrian Chilhowee Group and slightly metamorphosed Late Proterozoic Ocoee Supergroup west of the Greenbrier fault; (2) a central part containing crystalline basement of Middle Proterozoic age (Grenville), Ocoee Supergroup rocks east of the Greenbrier fault, and rocks of the Murphy belt; and (3) an east flank containing the Helen, Tallulah Falls, and Richard Russell thrust sheets and the amphibolitic basement complex. All of the east flank thrust sheets contain polydeformed and metamorphosed sedimentary and igneous rocks of mostly Proterozoic age. The Blue Ridge is separated by the Brevard fault zone from a large area of rocks of the Inner Piedmont to the east, which contains the Six Mile thrust sheet and the ChaugaWalhalla thrust complex. All of these rocks are also polydeformed and metamorphosed sedimentary and igneous rocks. The Inner Piedmont rocks in this area occupy both the Piedmont and part of the Blue Ridge physiographic provinces.

  9. Dielectric behaviors of Pb1-3x/2LaxTiO3 derived from mechanical activation

    International Nuclear Information System (INIS)

    Soon, H.P.; Xue, J.M.; Wang, J.

    2004-01-01

    To investigate the origin of ultrahigh relative permittivity that has been observed for lanthanum-doped lead titanate, Pb 1-3x/2 La x TiO 3 (PLT-A) with x ranging from 0.10 to 0.25 were synthesized by mechanical activation of constituent oxides. Their sintered density, grain size and relative permittivity demonstrated a steady increase with increasing of La doping. Upon thermal annealing in oxygen, the relative permittivity of Pb 0.70 La 0.2 TiO 3 (PLT-A20) at T c showed an initial rise and a peak at 4h of annealing, and then a steady fall with further increase in annealing time. In contrast, when annealed in nitrogen for 4 h, a significant rise in relative permittivity was observed, although the increase rate falls with prolonged annealing. The observed dependence of relative permittivity and dielectric loss for PLT-A20 on the initial annealing in both oxygen and nitrogen demonstrated the domination of space charge polarization as a result of PbO loss through evaporation from the surface region. While the high activation energy for Pb 2+ and O 2- diffusion through the surface scale slows down the rate of PbO loss through evaporation, excess loss of PbO adversely affect space charge polarization, leading to a fall in relative permittivity of PLT-A20, upon prolonged annealing in oxygen. In addition to PbO loss, prolonged annealing in nitrogen generated oxygen vacancies, which played an important role in affecting the relative permittivity

  10. Learning How to Learn

    DEFF Research Database (Denmark)

    Lauridsen, Karen M.; Lauridsen, Ole

    Ole Lauridsen, Aarhus School of Business and Social Sciences, Aarhus University, Denmark Karen M. Lauridsen, Aarhus School of Business and Social Sciences, Aarhus University, Denmark Learning Styles in Higher Education – Learning How to Learn Applying learning styles (LS) in higher education...... by Constructivist learning theory and current basic knowledge of how the brain learns. The LS concept will thus be placed in a broader learning theoretical context as a strong learning and teaching tool. Participants will be offered the opportunity to have their own LS preferences established before...... teaching leads to positive results and enhanced student learning. However, learning styles should not only be considered a didactic matter for the teacher, but also a tool for the individual students to improve their learning capabilities – not least in contexts where information is not necessarily...

  11. Pulse periods and the long-term variations of the X-ray pulsars VELA X-1 and Centaurus X-3

    Science.gov (United States)

    Tsunemi, Hiroshi

    The paper reports recent determinations of the pulse period for two X-ray pulsars, Vela X-1 and Cen X-3, made in 1987 with the All Sky Monitor (ASM) on board the Ginga satellite. The heliocentric pulse periods are 283.09 + or - 0.01 s and 4.8229 + or - 0.0001 s, respectively. These are the longest and shortest values in their respective observational histories. The random walk model for the Vela X-1 pulsar can explain this result as well as those obtained previously. It is also noted that the pulse-period change for the Cen X-3 system shows a 9-yr periodicity. This is probably due to the activity of the companion star rather than to Doppler-shift variations due to a third body or the precession of the neutron star.

  12. Ab initio pseudopotential calculations for the electronic and geometric structures of hydrogen covered Si(1 1 4)-(2x1)

    International Nuclear Information System (INIS)

    Smardon, R.D.; Srivastava, G.P.

    2004-01-01

    Using a first principles pseudopotential method we have studied the adsorption of H on the high index Si(1 1 4)-(2x1) surface within the local density approximation. This stable surface is found to be both chemically and electronically passivated by two different coverages of hydrogen: 1.0 ML and 1.5 ML. For the 1.0 ML coverage all the A- and B-type dimer bond lengths have equalised to 2.40 Angst and the rebonded lengths are slightly longer at 2.48 Angst. Hydrogen passivation, for both coverages, leads the surface bands of the clean Si(1 1 4)-(2x1) surface to move into the bulk valence and conduction bands. Differences in the density of states for the clean, 1.0 ML and 1.5 ML coverages were observed and are discussed

  13. Zn{sub x-1}Cu{sub x}Mn{sub 2}O{sub 4} spinels; synthesis, structural characterization and electrical evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Mendez M, F.; Lima, E.; Bosch, P.; Pfeiffer, H. [UNAM, Instituto de Investigaciones en Materiales, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Gonzalez, F., E-mail: pfeiffer@iim.unam.m [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2010-07-01

    This work presents the structural characterization and electrical evaluation of Zn{sub x-1}Cu{sub x}Mn{sub 2}O{sub 4} spinels, which are materials presented as secondary phases into the vari stor ceramic systems. Samples were analyzed by X-ray diffraction, solid-state nuclear magnetic resonance, infrared spectroscopy, scanning electron microscopy and impedance spectroscopy. Although, the addition of copper to the ZnMn{sub 2}O{sub 4} spinel did not produce morphological changes, the structure and electrical behaviors changed considerably. Structurally, copper addition induced the formation of partial inverse spinels, and its addition increases significantly the electrical conductivity. Therefore, the formation of Zn{sub x-1}Cu{sub x}Mn{sub 2}O{sub 4} spinels, as secondary phases into the vari stor materials, may compromise significantly the vari stor efficiency. (Author)

  14. Demonstration of 352 Gbit/s Photonically-enabled D-Band Wireless Delivery in one 2x2 MIMO System

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Yu, Jianjun; Li, Xinying

    2017-01-01

    First demonstration of photonically-enabled independent side-bands D-Band wireless transmission up to 352 Gbit/s with a BER below 3.8×10-3. These results were achieved by means of advanced DSP and antenna polarization multiplexing (2x2 MIMO)....

  15. Oriented crystalline monolayers and bilayers of 2 x 2 silver(1) grid architectures at the air-solution interface: Their assembly and crystal structure elucidation

    DEFF Research Database (Denmark)

    Weissbuch, J.; Baxter, P.N.W.; Kuzmenko, I.

    2000-01-01

    Oriented crystalline monolayers, similar to 14 Angstrom thick, of a 2 x 2 Ag+ grid complex, self-assembled at the air-solution interface starting from an water-insoluble ligand 3,6-bis[2-(6-phenylpyridine)]pyridazine spread on silver-ion-containing solutions,were examined by grazing-incidence X...

  16. Screened Raman response in two-dimensional d(x2-y2)-wave superconductors: Relative intensities in different symmetry channels

    DEFF Research Database (Denmark)

    Wenger, F.; Käll, M.

    1997-01-01

    We analyze the Raman-scattering response in a two-dimensional d(x2-y2)-wave superconductor and point out a strong suppression of relative intensity in the screened A(1g) channel compared to the B-1g channel for a generic tight-binding model. This is in contrast with the observed behavior in high...

  17. A 2 x 2 imaging MIMO system based on LED Visible Light Communications employing space balanced coding and integrated PIN array reception

    DEFF Research Database (Denmark)

    Li, Jiehui; Xu, Yinfan; Shi, Jianyang

    2016-01-01

    In this paper, we proposed a 2 x 2 imaging Multi-Input Multi-Output (MIMO)-Visible Light Communication (VLC) system by employing Space Balanced Coding (SBC) based on two RGB LEDs and integrated PIN array reception. We experimentally demonstrated 1.4-Gbit/s VLC transmission at a distance of 2.5 m...

  18. On the Nature of the Variability Power Decay towards Soft Spectral States in X-Ray Binaries. Case Study in Cyg X-1

    Science.gov (United States)

    Titarchuk, Lev; Shaposhinikov, Nikolai

    2007-01-01

    A characteristic feature of the Fourier Power Density Spectrum (PDS) observed from black hole X-ray binaries in low/hard and intermediate spectral states is a broad band-limited noise, characterized by a constant below some frequency (a "break" frequency) and a power law above this frequency. It has been shown that the variability of this type can be produced by the inward diffusion of the local driving perturbations in a bounded configuration (accretion disk or corona). In the framework of this model, the perturbation diffusion time to is related to the phenomenological break frequency, while the PDS power-law slope above the "break" is determined by the viscosity distribution over the configuration. The perturbation diffusion scenario explains the decay of the power of X-ray variability observed in a number of compact sources (containing black hole and neutron star) during an evolution of theses sources from low/hard to high/soft states. We compare the model predictions with the subset of data from Cyg X-1 collected by the Rossi X-ray Time Explorer (RXTE). Our extensive analysis of the Cyg X-1 PDSs demonstrates that the observed integrated power P(sub x), decreases approximately as a square root of the characteristic frequency of the driving oscillations v(sub dr). The RXTE observations of Cyg X-1 allow us to infer P(sub dr), and t(sub o) as a function of v(sub dr). We also apply the basic parameters of observed PDSs, power-law index and low frequency quasiperiodic oscillations. to infer Reynolds (Re) number from the observations using the method developed in our previous paper. Our analysis shows that Re-number increases from values about 10 in low/hard state to that about 70 during the high/soft state. Subject headings: accretion, accretion disks-black hole physics-stars:individual (Cyg X-1) :radiation mechanisms: nonthermal-physical data and processes

  19. On the Nature of the mHz X-Ray QPOs from ULX M82 X-1: Evidence for Timing-Spectral (anti) Correlation

    Science.gov (United States)

    Pasham, Dheeraj R.; Strohmayer, Tod E.

    2013-01-01

    Using all the archival XMM-Newton X-ray (3-10 keV) observations of the ultraluminous X-ray source (ULX) M82 X-1 we searched for a correlation between its variable mHz quasi-periodic oscillation (QPO) frequency and its energy spectral power-law index. These quantities are known to correlate in stellar mass black holes (StMBHs) exhibiting Type-C QPOs (approx 0.2-15 Hz). The detection of such a correlation would strengthen the identification of its mHz QPOs as Type-C and enable a more reliable mass estimate by scaling its QPO frequencies to those of Type-C QPOs in StMBHs of known mass. We resolved the count rates of M82 X-1 and a nearby bright ULX (source 5/X42.3+59) through surface brightness modeling and identify observations in which M82 X-1 was at least as bright as source 5. Using only those observations, we detect QPOs in the frequency range of 36-210 mHz during which the energy spectral power-law index varied from 1.7-2.2. Interestingly, we find evidence for an anti-correlation (Pearsons correlation coefficient = -0.95) between the power-law index and the QPO centroid frequency. While such an anti-correlation is observed in StMBHs at high Type-C QPO frequencies (approx 5-15 Hz), the frequency range over which it holds in StMBHs is significantly smaller (factor of approx 1.5-3) than the QPO range reported here from M82 X-1 (factor of 6). However, it remains possible that contamination from source 5 can bias our result. Joint Chandra/XMM-Newton observations in the future can resolve this problem and confirm the timing-spectral anti-correlation reported here.

  20. Learning to Learn.

    Science.gov (United States)

    Weiss, Helen; Weiss, Martin

    1988-01-01

    The article reviews theories of learning (e.g., stimulus-response, trial and error, operant conditioning, cognitive), considers the role of motivation, and summarizes nine research-supported rules of effective learning. Suggestions are applied to teaching learning strategies to learning-disabled students. (DB)

  1. A 1990 global emission inventory of anthropogenic sources of carbon monoxide on 1o x 1o developed in the framework of EDGAR/GEIA

    International Nuclear Information System (INIS)

    Olivier, J.G.J.; Bouwman, A.F.; Bloos, J.P.J.; Berdowski, J.J.M.; Visschedijk, A.J.H.

    1999-01-01

    A global emission inventory of carbon monoxide (CO) emissions with 1 o x 1 o latitude-longitude resolution was compiled for 1990 on a sectoral basis. The sectoral sources considered include large-scale biomass burning (29%, of which savanna burning, 18%, and deforestation, 11%), fossil fuel combustion (27%, predominantly in road transport), biofuel combustion (19%, predominantly fuelwood combustion), agricultural waste burning (21%) and industrial process sources (4%). The inventory was compiled using mostly national statistics as activity data, emission factors at global or country level, and specific grid maps to convert, by sector, country total emissions to the 1 o x 1 o grid. A special effort was made to compile a global inventory of biofuel use, since this was considered to be a significant source on a global level, and a major source in some regions such as India and China. The global anthropogenic source of CO in 1990 is estimated at about 974 Tg CO yr -1 . The inventory is available on a sectoral basis on a 1 o x 1 o grid for input to global atmospheric models and on a regional/country basis for policy analysis. (author)

  2. The spectral and temporal behavior of the variable X-ray binary star Cyg X-1 in the hard region of X-radiation

    International Nuclear Information System (INIS)

    Steinle, H.

    1981-01-01

    In the present work the measurements of the X-ray spectrum of Cyg X-1 in the energy range 15 to 160 keV in the years 1975, 1976, 1977 are investigated. The measurements are of such a good quality, that a simple power spectrum as the best fit of a model to the data of Cyg X-1 can be excluded because the spectrum breaks off in the range 70-100 keV. The model of Sunyaev and Titarchuk which describes the comptonizing of protons will low energy in a hot plasma is used first time for filling to the Cyg X-1 spectra and it is seen, that the shape of the spectrum is represented in an excellent manner. From the parameters of the best fit to the spectrum from 1977 an electron temperature of 3.4 x 10 8 K and an optical depth tau = 5 for the plasma in which the photons are scattered are found. (orig./WB) [de

  3. Crystal and Electronic Structures, Photoluminescence Properties of Eu2+-Doped Novel Oxynitride Ba4Si6O16-3x/2Nx

    Directory of Open Access Journals (Sweden)

    Takashi Takeda

    2010-03-01

    Full Text Available The crystal structure and the photoluminescence properties of novel green Ba4-yEuySi6O16-3x/2Nx phosphors were investigated. The electronic structures of the Ba4Si6O16 host were calculated by first principles pseudopotential method based on density functional theory. The results reveal that the top of the valence bands are dominated by O-2p states hybridized with Ba-6s and Si-3p states, while the conduction bands are mainly determined by Ba-6s states for the host, which is an insulator with a direct energy gap of 4.6 eV at Γ. A small amount of nitrogen can be incorporated into the host to replace oxygen and forms Ba4-yEuySi6O16-3x/2Nx solid solutions crystallized in a monoclinic (space group P21/c, Z = 2 having the lattice parameters a = 12.4663(5 Å, b = 4.6829(2 Å, c = 13.9236(6 Å, and β = 93.61(1°, with a maximum solubility of nitrogen at about x = 0.1. Ba4Si6O16-3x/2Nx:Eu2+ exhibits efficient green emission centered at 515–525 nm varying with the Eu2+ concentration when excited under UV to 400 nm. Furthermore, the incorporation of nitrogen can slightly enhance the photoluminescence intensity. Excitation in the UV-blue spectral range (λexc = 375 nm, the absorption and quantum efficiency of Ba4-yEuySi6O16-3x/2Nx (x = 0.1, y = 0.2 reach about 80% and 46%, respectively. Through further improvement of the thermal stability, novel green phosphor of Ba4-yEuySi6O16-3x/2Nx is promising for application in white UV-LEDs.

  4. Magic clusters and (2x1) local structure formed in a half-unit cell of the Si(1 1 1)-(7x7) surface by Tl adsorption

    International Nuclear Information System (INIS)

    Kocan, P.; Visikovskiy, A.V.; Ohira, Y.; Yoshimura, M.; Ueda, K.; Tochihara, H.

    2008-01-01

    Formation of a (2x1) local structure is found at submonolayer growth of Tl on the Si(1 1 1)-(7x7) surface by means of scanning tunneling microscopy (STM). At low coverages, the (7x7) grid remains and the (2x1) structure is formed inside of the half-unit cells of the (7x7). The (2x1) coexists with other structures, such as of 'magic' clusters observed in the case of all other group III metals. Based on our STM observations we propose an atomic arrangement of the (2x1) structure

  5. The effect of learning models and emotional intelligence toward students learning outcomes on reaction rate

    Science.gov (United States)

    Sutiani, Ani; Silitonga, Mei Y.

    2017-08-01

    This research focused on the effect of learning models and emotional intelligence in students' chemistry learning outcomes on reaction rate teaching topic. In order to achieve the objectives of the research, with 2x2 factorial research design was used. There were two factors tested, namely: the learning models (factor A), and emotional intelligence (factor B) factors. Then, two learning models were used; problem-based learning/PBL (A1), and project-based learning/PjBL (A2). While, the emotional intelligence was divided into higher and lower types. The number of population was six classes containing 243 grade X students of SMAN 10 Medan, Indonesia. There were 15 students of each class were chosen as the sample of the research by applying purposive sampling technique. The data were analyzed by applying two-ways analysis of variance (2X2) at the level of significant α = 0.05. Based on hypothesis testing, there was the interaction between learning models and emotional intelligence in students' chemistry learning outcomes. Then, the finding of the research showed that students' learning outcomes in reaction rate taught by using PBL with higher emotional intelligence is higher than those who were taught by using PjBL. There was no significant effect between students with lower emotional intelligence taught by using both PBL and PjBL in reaction rate topic. Based on the finding, the students with lower emotional intelligence were quite hard to get in touch with other students in group discussion.

  6. Separation of plutonium on the anion exchanger BIO-RAD 1-X2 and its application to radiochemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bajo, S.; Gann, C.; Eikenberg, J.; Wyer, L.; Beer, H.; Ruethi, M.; Jaeggi, M.; Zumsteg, I

    2007-12-15

    . This report describes the extensive utilization of the classical anion exchanger BIO-RAD 1-X2 in 8 molar nitric acid for the separation of plutonium from matrices such as air filters, concrete, cooling reactor water, faeces, smear reactor samples, and soils, and for the purification of plutonium tracers. Detailed procedures are given for all these matrices, from the dissolution of the sample to the final electro deposition preceding alpha spectrometry. Also included is the behaviour in the anion exchanger of potentially interfering nuclides of elements such as Am, Np, Po, Th, and U. Special attention has been given to the isotopic exchange between plutonium in the sample and the plutonium tracer added for the recovery determination, as well as some usual operations performed during the analysis.

  7. Separation of plutonium on the anion exchanger BIO-RAD 1-X2 and its application to radiochemical analysis

    International Nuclear Information System (INIS)

    Bajo, S.; Gann, C.; Eikenberg, J.; Wyer, L.; Beer, H.; Ruethi, M.; Jaeggi, M.; Zumsteg, I.

    2007-12-01

    The element Pu (Z = 94) is a member of the actinide series of the elements (Z = 89 -103). The actinides have similar chemical properties and are also similar to the lanthanides (Z = 57 -71). Sixteen isotopes of Pu have been synthesized, all of which are radioactive. The Pu present in the environment originates from the atmospheric nuclear tests from 1950 to 1963, which produced the so-called 'global fallout'. As a result, 6.5 · 10 15 Bq 239 Pu (2.8 tons), 4.4 · 10 15 Bq 240 Pu (0.52 tons), and 3.7 · 10 4 Bq 241 Pu (0.04 tons) were dispersed over the world. A contribution also to the global fallout was the ignition of the satellite SWAP 9A in the atmosphere in 1964, equipped with a battery powered by 6.3 · 10 14 Bq (1 kg) of 238 Pu. In addition to these sources, nuclear reactors, reprocessing plants and radioactive waste facilities may contribute with their emissions to increase locally the Pu concentration in their environment. In the PSI laboratory, we are confronted with the determination of traces of 238 Pu, 239 Pu and 240 Pu in environmental and biological materials. Because of the low quantity of Pu in the analyzed samples, which is usually below 100 mBq, it is mandatory to separate the Pu from all other accompanying elements. The separated Pu is then measured by alpha spectrometry. In this work, the anion exchanger BIO-RAD AG 1 is extensively used for the separation of Pu from different matrices. This exchanger is superior when only Pu is determined in the sample. In addition, it is also very suitable when other actinides, such as Am and Cm, are also determined. No preconcentration step is necessary for the Pu separation. The resins introduced by the company Eichrom Industries in the 90's, which allow the separation of the actinides from the major environmental elements and from each other, requires relatively small volumes of sample solution. This report describes the extensive utilization of the classical anion exchanger BIO-RAD 1-X2 in 8 molar nitric

  8. Learning Styles.

    Science.gov (United States)

    Missouri Univ., Columbia. Coll. of Education.

    Information is provided regarding major learning styles and other factors important to student learning. Several typically asked questions are presented regarding different learning styles (visual, auditory, tactile and kinesthetic, and multisensory learning), associated considerations, determining individuals' learning styles, and appropriate…

  9. Learning Networks, Networked Learning

    NARCIS (Netherlands)

    Sloep, Peter; Berlanga, Adriana

    2010-01-01

    Sloep, P. B., & Berlanga, A. J. (2011). Learning Networks, Networked Learning [Redes de Aprendizaje, Aprendizaje en Red]. Comunicar, XIX(37), 55-63. Retrieved from http://dx.doi.org/10.3916/C37-2011-02-05

  10. Study of Ni50+xMn25Ga25-x (x = 2-11) as high-temperature shape-memory alloys

    International Nuclear Information System (INIS)

    Ma Yunqing; Jiang Chengbao; Li Yan; Xu Huibin; Wang Cuiping; Liu Xingjun

    2007-01-01

    Ni 50+x Mn 25 Ga 25-x (x = 2-11) alloys were studied as high-temperature shape-memory alloys, with regard to their microstructure, martensitic transformation behavior and high-temperature shape-memory effect. Single phase of martensite with tetragonal structure was present for x p increase monotonically from 39.1 deg. C for x = 2 to 443.8 deg. C for x = 7, then remain almost constant at 440 deg. C for x ≥ 7. The shape-memory strains of the alloys decreased gradually from 6.1% for x = 4 to 2.8% for x = 8 and 0% for x = 11 under the same pre-strain. The variations of the martensitic transformation temperatures and the shape-memory effects with Ni contents correlate with changes in size factor, electron concentration and precipitation of γ phase

  11. Nascent rotational distributions of N+2(X 2Σ+/sub g/) produced by electron-impact ionization of N2 in a supersonic beam

    International Nuclear Information System (INIS)

    Nagata, T.; Nakajima, A.; Kondow, T.; Kuchitsu, K.

    1987-01-01

    Laser-induced fluorescence from nascent N + 2 (X 2 Σ + /sub g/) ions produced by electron impact on a N 2 supersonic beam was observed. An analysis of the B 2 Σ + /sub u/-X 2 Σ + /sub g/ (0,0) band shows that the rotational state distributions cannot be represented by a single Boltzmann function, higher N'' levels being overpopulated. Experimental and analytical efforts were made to minimize the influence of cascading and relaxation on the rotational distributions. The rotational energy of N + 2 (X) thus estimated increases with decreasing electron energy from 2.26 +- 0.16 meV at 300 eV to 4.24 +- 0.27 meV at 25 eV. This trend is explained qualitatively in terms of angular momentum transfer through multipole electron--molecule interactions

  12. High Eu 4f low-energy oscillator strength in the isostructural rare-earth Zintl compounds EuIn2X2 (X = P,As)

    KAUST Repository

    Singh, Nirpendra

    2012-04-11

    The isostructral Zintl compounds EuIn2X2 (X = P,As) are investigated within density functional theory. We employ the local spin density approximation with onsite interaction (LSDA + U) for varying U from 0 eV to 7 eV to model the Coulomb repulsion of the Eu 4f electrons. The LSDA + U optical conductivity disagrees with the experimental spectrum, while the simple LSDA is successful. Contrary to the expectation, it is found that EuIn2X2 (X = P,As) has a large oscillator strength for the f → d transitions in the low-energy range (below 1.5 eV) in which effects of the joint density of states play a key role. The materials show a sizeable magneto-optical Kerr effect.

  13. Sport ability beliefs, 2 x 2 achievement goals, and intrinsic motivation: the moderating role of perceived competence in sport and exercise.

    Science.gov (United States)

    Wang, C K John; Liu, Woon Chia; Lochbaum, Marc R; Stevenson, Sarah J

    2009-06-01

    We examined whether perceived competence moderated the relationships between implicit theories, 2 x 2 achievement goals, and intrinsic motivation for sports and physical activity. We placed 309 university students into high and moderate perceived competence groups. When perceived competence was high, entity beliefs did not predict the performance-avoidance goal; yet when perceived competence was moderately low, entity beliefs did predict this goal. The mastery-avoidance goal had no relationship with intrinsic motivation when perceived competence was high, but had a significant negative relationship when perceived competence was moderately low. Our findings highlight the importance of reexamining the role of perceived competence when studying implicit beliefs and the 2 x 2 achievement goals.

  14. Expression of the P2X2 receptor in different classes of ileum myenteric neurons in the female obese ob/ob mouse

    Science.gov (United States)

    Mizuno, Márcia Sanae; Crisma, Amanda Rabello; Borelli, Primavera; Castelucci, Patricia

    2012-01-01

    AIM: To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system abnormalities such as altered motility. METHODS: The study examined the distribution of the P2X2 receptor (P2X2R) in myenteric neurons of female ob/ob mice. Specifically, we used immunohistochemistry to analyze the co-expression of the P2X2R with neuronal nitric oxide synthase (nNOS), choline acetyltransferase (ChAT), and calretinin (CalR) in neurons of the small intestine myenteric plexus in ob/ob and control female mice. In these sections, we used scanning confocal microscopy to analyze the co-localization of these markers as well as the neuronal density (cm2) and area profile (μm²) of P2X2R-positive neurons. In addition, enteric neurons were labeled using the nicotinamide adenine dinucleotide (NADH) diaphorase method and analyzed with light microscopy as an alternate means by which to analyze neuronal density and area. RESULTS: In the present study, we observed a 29.6% increase in the body weight of the ob/ob animals (OG) compared to the control group (CG). In addition, the average small intestine area was increased by approximately 29.6% in the OG compared to the CG. Immunoreactivity (IR) for the P2X2R, nNOS, ChAT and CalR was detectable in the myenteric plexus, as well as in the smooth muscle, in both groups. This IR appeared to be mainly cytoplasmic and was also associated with the cell membrane of the myenteric plexus neurons, where it outlined the neuronal cell bodies and their processes. P2X2R-IR was observed to co-localize 100% with that for nNOS, ChAT and CalR in neurons of both groups. In the ob/ob group, however, we observed that the neuronal density (neuron/cm2) of P2X2R-IR cells was increased by 62% compared to CG, while that of NOS-IR and ChAT-IR neurons was reduced by 49% and 57%, respectively, compared to control mice. The neuronal density of CalR-IR neurons was not different between the groups. Morphometric studies further demonstrated that the

  15. High Eu 4f low-energy oscillator strength in the isostructural rare-earth Zintl compounds EuIn2X2 (X = P,As)

    KAUST Repository

    Singh, Nirpendra; Schwingenschlö gl, Udo

    2012-01-01

    The isostructral Zintl compounds EuIn2X2 (X = P,As) are investigated within density functional theory. We employ the local spin density approximation with onsite interaction (LSDA + U) for varying U from 0 eV to 7 eV to model the Coulomb repulsion of the Eu 4f electrons. The LSDA + U optical conductivity disagrees with the experimental spectrum, while the simple LSDA is successful. Contrary to the expectation, it is found that EuIn2X2 (X = P,As) has a large oscillator strength for the f → d transitions in the low-energy range (below 1.5 eV) in which effects of the joint density of states play a key role. The materials show a sizeable magneto-optical Kerr effect.

  16. Chronic administration of the selective P2X3, P2X2/3 receptor antagonist, A-317491, transiently attenuates cancer-induced bone pain in mice

    DEFF Research Database (Denmark)

    Hansen, Rikke Rie; Nasser, Arafat; Falk, Sarah

    2012-01-01

    The purinergic P2X3 and P2X2/3 receptors are in the peripheral nervous system almost exclusively confined to afferent sensory neurons, where they are found both at peripheral and central synapses. The P2X3 receptor is implicated in both neuropathic and inflammatory pain. However, the role of the ......X3 receptor in chronic cancer-induced bone pain is less known. Here we investigated the effect of systemic acute and chronic administration of the selective P2X3, P2X2/3 receptor antagonist (5-[[[(3-Phenoxyphenyl)methyl][(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]carbonyl]-1...

  17. The RELixSn2 (RE=La–Nd, Sm, and Gd; 0≤x<1) series revisited. Synthesis, crystal chemistry, and magnetic susceptibilities

    International Nuclear Information System (INIS)

    Makongo, Julien P.A.; Suen, Nian-Tzu; Guo, Shengping; Saha, Shanta; Greene, Richard; Paglione, Johnpierre; Bobev, Svilen

    2014-01-01

    This study is concerned with the ternary compounds RELi x Sn 2 (RE=La–Nd, Sm, and Gd; 0≤x 2 phases. These materials crystallize with the base-centered orthorhombic space group Cmcm (No. 63), and can be formally assigned with the CeNiSi 2 structure type (Pearson symbol oC16). Our systematic single-crystal X-ray diffraction studies revealed substantial Li-deficiencies in all cases, with SmSn 2 (space group Cmmm, ZrGa 2 structure type, Pearson symbol oC12) and GdSn 2 (space group Cmcm, ZrSi 2 structure type, Pearson symbol oC12) being completely lithium-free. The structure refinements also uncovered positional disorder on the Sn site neighboring the vacancies. The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 and GdSn 2 structures are devoid of any disorder. Temperature-dependent studies of the magnetic response of the title compounds are also presented and discussed. -- Graphical abstract: RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type (a). The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 (b) and GdSn 2 (c) structures are devoid of any disorder. Highlights: • The crystal structures of the RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type or defect variant of the CeNiSi 2 structure type. • SmSn 2 is isotypic with the ZrGa 2 structure, while RESn 2 (RE=Gd–Lu) are isotypic with the ZrSi 2 structure

  18. Geology and mineral resources of the Florence, Beaufort, Rocky Mount, and Norfolk 1/sup 0/ x 2/sup 0/ NTMS quadrangles. National Uranium Resource Evaluation program

    Energy Technology Data Exchange (ETDEWEB)

    Harris, W.B.

    1982-08-01

    This document provides geologic and mineral resources data for previously-issued Savannah River Laboratory hydrogeochemical and stream sediment reports of the Beaufort, Florence, Norfolk, and Rocky Mount 1/sup 0/ x 2/sup 0/ National Topographic Map Series quadrangles in the southeastern United States. This report is issued in draft form, without detailed technical and copy editing. This was done to make the report available to the public before the end of the National Uranium Resource Evaluation program.

  19. Quasi-classical trajectory approach to the O(1D)+HBr→OH+Br reaction stereo-dynamics on X1A' potential energy surface

    International Nuclear Information System (INIS)

    Li Hong; Zheng Bin; Yin Ji-Qing; Meng Qing-Tian

    2011-01-01

    The vector properties of reaction O( 1 D)+HBr→OH+Br on the potential energy surface (PES) of X 1 A' ground singlet state are studied by using the quasi-classical trajectory (QCT) theory. The polarization-dependent differential cross sections (PDDCSs), the average rotational alignment factor 2 (j' · k)>, as well as the distributions reflecting vector correlations are also computed. The analysis of the results shows that the alignment and the orientation distribution of the rotation angular momentum vector of product molecule OH is influenced by both the effect of heavy—light—heavy (HLH) type mass combination and the deep well of PES. (atomic and molecular physics)

  20. Hexagonal perovskites with cationic vacancies. 25. Hexagonal 5 L stacking polytypes in the systems Ba/sub 5/BaWsub(3-x)sup(VI)Msub(x)sup(V)vacantOsub(15-x/2)vacantsub(x/2) with Msup(V) = Nb, Ta

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1980-12-01

    In the systems BaO-M/sub 2/sup(V)O/sub 5/-WO/sub 3/ (Msup(V) = Nb, Ta) a new phase Ba/sub 5/BaWsub(3-x)Msub(x)sup(V)vacantOsub(15-x/2)vacantsub(x/2) with hexagonal 5 L structure (sequence hhccc; space group P-3m1) could be prepared. The range of existence is restricted to Msup(V) containing compounds. With Msup(V) = Nb the lower phase boundary is x = 3. In the Ta system it is reached between x = 2 and 3; the pure Ta pervoskite (Ba:Ta:O = 6:3:13 1/2 = 4:2:9) represents the final member of the series Ba/sub 3/Srsub(1-y)Basub(y)Ta/sub 2/O/sub 9/ with y = 1.

  1. Demonstration of high mobility and quantum transport in modulation-doped β-(AlxGa1-x)2O3/Ga2O3 heterostructures

    Science.gov (United States)

    Zhang, Yuewei; Neal, Adam; Xia, Zhanbo; Joishi, Chandan; Johnson, Jared M.; Zheng, Yuanhua; Bajaj, Sanyam; Brenner, Mark; Dorsey, Donald; Chabak, Kelson; Jessen, Gregg; Hwang, Jinwoo; Mou, Shin; Heremans, Joseph P.; Rajan, Siddharth

    2018-04-01

    In this work, we demonstrate a high mobility two-dimensional electron gas (2DEG) formed at the β-(AlxGa1-x)2O3/Ga2O3 interface through modulation doping. Shubnikov-de Haas (SdH) oscillations were observed in the modulation-doped β-(AlxGa1-x)2O3/Ga2O3 structure, indicating a high-quality electron channel formed at the heterojunction interface. The formation of the 2DEG channel was further confirmed by the weak temperature dependence of the carrier density, and the peak low temperature mobility was found to be 2790 cm2/Vs, which is significantly higher than that achieved in bulk-doped Beta-phase Gallium Oxide (β-Ga2O3). The observed SdH oscillations allowed for the extraction of the electron effective mass in the (010) plane to be 0.313 ± 0.015 m0 and the quantum scattering time to be 0.33 ps at 3.5 K. The demonstrated modulation-doped β-(AlxGa1-x)2O3/Ga2O3 structure lays the foundation for future exploration of quantum physical phenomena and semiconductor device technologies based on the β-Ga2O3 material system.

  2. Preparation and characterization of (CuInSe{sub 2}){sub 1-x}(CoSe){sub x} alloys in the composition range 0{<=}x{<=}2/3

    Energy Technology Data Exchange (ETDEWEB)

    Grima-Gallardo, P.; Munoz, M.; Ruiz, J.; Power, C.; Gonzalez, J. [Centro de Estudios en Semiconductores (C.E.S.), Dpto. Fisica, Fac. Ciencias, Universidad de Los Andes, La Hechicera, Merida (Venezuela); LeGodec, Y.; Munsch, P.; Itie, J.P. [Laboratoire de Physique des Milieux Condenses, Universite Pierre et Marie Curie, Paris VI, Paris (France); Briceno, V. [Facultad Experimental de Ciencias y Tecnologia (FACYT), Dpto. Fisica, Universidad de Carabobo, Valencia (Venezuela); Briceno, J.M. [Laboratorio de Analisis Quimico y Estructural (LAQUEM), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela)

    2004-07-01

    Polycrystalline samples of (CuInSe{sub 2}){sub 1-x}(CoSe){sub x} alloys were prepared by the normal melt and anneal technique in the composition range 0<x{<=}2/3. The obtained ingots were characterized by scanning electron microscopy, X-ray diffraction and differential thermal analysis techniques. A sample with x=2/3 (prepared a posteriori) was also studied by the Raman shift technique. The results showed a complex behavior of the phase diagram. The phase ({alpha}) with chalcopyrite structure exists in a narrow interval 0x<2/3, another chalcopyrite-like phase ({alpha}{sup ''}) was observed together with traces of the {gamma} phase. The sequence of phase transformations in the studied composition range seems to be {alpha} {yields} {alpha}' {yields} {alpha}'+{gamma} {yields} {alpha}{sup ''}+{gamma}. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Schottky barrier height of Ni to β-(AlxGa1-x)2O3 with different compositions grown by plasma-assisted molecular beam epitaxy

    Science.gov (United States)

    Ahmadi, Elaheh; Oshima, Yuichi; Wu, Feng; Speck, James S.

    2017-03-01

    Coherent β-(AlxGa1-x)2O3 films (x = 0, 0.038, 0.084, 0.164) were grown successfully on a Sn-doped β-Ga2O3 (010) substrate using plasma-assisted molecular beam epitaxy. Atom probe tomography, transmission electron microscopy, and high resolution x-ray diffraction were used to verify the alloy composition and high quality of the films. Schottky diodes were then fabricated using Ni as the Schottky metal. Capacitance-voltage measurements revealed a very low (current-voltage (I-V) measurements performed at temperatures varying from 300 K to 500 K on the Schottky diodes. These measurements revealed that the apparent Schottky barrier height could have similar values for different compositions of β-(AlxGa1-x)2O3. We believe this is attributed to the lateral fluctuation in the alloy’s composition. This results in a lateral variation in the barrier height. Therefore, the average Schottky barrier height extracted from I-V measurements could be similar for β-(AlxGa1-x)2O3 films with different compositions.

  4. Oxidation of cyclic amines by molybdenum(II and tungsten(II halocarbonyls, [M(CO4X2]2 (M = Mo, W; X = Cl, Br

    Directory of Open Access Journals (Sweden)

    H.M. Mbuvi

    2013-05-01

    Full Text Available The molybdenum(II and tungsten(II halocarbonyls, [M(CO4X2]2 (M = Mo, W; X = Cl, Br react with a large excess of the nitrogen bases, 1-methylpyrrolidine, 1-methylpiperidine, 1-ethylpiperidine and 2-ethylpiperidine to give aminecarbonyl complexes of the type M(CO3L3 (L= alkylamine. Excess piperidine reacts with the tungsten halocarbonyls, [W(CO4X2]2 (X = Cl, Br, to give the trans isomer of the complex, W(CO3(C5H11N3. The halogens were recovered as the amminium salts, amine, HX. The oxidized amine dimerized to form a yellow product which was recovered as an oily liquid but in very small amounts. However, in the reaction between Mo(CO4Br2 and 1-ethylpiperidine, a yellow crystalline solid, with a melting point of 224 oC was recovered in sufficient amounts for elemental analysis, melting point and spectral data. Its mass spectrum showed a molecular ion peak at m+/z = 222, a clear evidence that the oxidized amine dimerizes. The cyclic dibasic amine piperazine, C4H10N2 is not, however, oxidized by these halocarbonyls but rather it reacts by substituting some CO groups to form products of the type, M(CO3(C4H10N22X2 (M = Mo, W; X = Cl, Br. Products were characterized by elemental analysis, IR, UV, 1H NMR and mass spectrometry.

  5. Does one-dimensional (1D) adatom and cluster diffusion of Pt on the Pt(110)-(1 x 2) surface lead to 1D ripening?

    International Nuclear Information System (INIS)

    Linderoth, T R; Horch, S; Petersen, L; Laegsgaard, E; Stensgaard, I; Besenbacher, F

    2005-01-01

    The technique of scanning tunnelling microscopy (STM) uniquely allows dynamic processes on surfaces to be followed directly in real space and at atomic resolution. Results for the 551225 surface diffusion of Pt adatoms and clusters on the anisotropic, missing row reconstructed Pt(110)-(1 x 2) surface are briefly reviewed. Mass transport in this system is entirely one-dimensional (1D) since, at low adatom coverage, atoms and clusters are confined to the missing row troughs. In this paper, we therefore address the question if Pt/Pt(110)-(1 x 2) is a 1D model system to study late stage growth phenomena such as island ripening? From STM measurements, we quantify the morphology changes resulting from annealing a surface configuration with small 1D Pt islands in the missing row troughs to temperatures in the interval 369-395 K. Interestingly, the resulting increase in island sizes (ripening) cannot be accounted for by the known island and adatom mobilities within a 1D model. An explanation is provided from dynamic, time-resolved 'STM-movies' that directly reveal two novel island-mediated mechanisms for inter-trough mass transport which cause the Pt/Pt(110)-(1 x 2) system not to be purely 1D at the higher surface coverage used in the annealing experiments

  6. Evaluation of skin surface hydration state and barrier function of stratum corneum of dorsa of hands and heels treated with PROTECT X2 skin protective cream.

    Science.gov (United States)

    Kubota, Takahiro

    2012-06-01

    Skin roughness is a term commonly used in Japan to describe a poor skin condition related to a rough and dry skin surface that develops as a result of various damaging effects from the environment or skin inflammation. Recovery from skin roughness requires skin care for a long period, thus it is important to prevent development of such skin changes. PROTECT X2 contains agents used for a protective covering of the skin from frequent hand washing or use of alcohol-based disinfectants. These unique components are also thought to be effective to treat skin roughness of the dorsa of the hands and heels. In the present study, we evaluated the effectiveness of PROTECT X2 to increase skin surface hydration state, as well as enhance the barrier function of the stratum corneum of the dorsa of the hands and heels in elderly individuals. A total of 8 elderly subjects and their caretakers without any skin diseases participated in the study. They applied PROTECT X2 by themselves to the dorsum area of 1 hand and heel 3 to 5 times daily for 1 month, while the opposite sides were left untreated. We measured stratum corneum (SC) hydration and transepidermal water loss (TEWL) before beginning treatment, then 1 week and 1 month after the start of treatment to compare between the treated and untreated skin. SC hydration state after applications of PROTECT X2 was 1.5- to 3.0-fold higher than that of the untreated skin in the dorsa of both hands and heels, indicating that the moisturizing ingredients accompanied by water were replenished in those areas where the cream was applied. Also, TEWL in the dorsum of the hands was 17.0-27.9% lower on the treated side, indicating improvement in SC barrier function. On the basis of these findings, we concluded that PROTECT X2 enhances water-holding in the SC and aids the barrier function of the skin in the dorsum of the hands. In addition, we consider that this formulation is useful for not only protecting the hands from the effects of such agents

  7. Nance-Horan syndrome in females due to a balanced X;1 translocation that disrupts the NHS gene: Familial case report and review of the literature.

    Science.gov (United States)

    Gómez-Laguna, Laura; Martínez-Herrera, Alejandro; Reyes-de la Rosa, Alejandra Del Pilar; García-Delgado, Constanza; Nieto-Martínez, Karem; Fernández-Ramírez, Fernando; Valderrama-Atayupanqui, Tania Yanet; Morales-Jiménez, Ariadna Berenice; Villa-Morales, Judith; Kofman, Susana; Cervantes, Alicia; Morán-Barroso, Verónica Fabiola

    2018-01-01

    The Nance-Horan syndrome is an X-linked disorder characterized by congenital cataract, facial features, microcornea, microphthalmia, and dental anomalies; most of the cases are due to NHS gene mutations on Xp22.13. Heterozygous carrier females generally present less severe features, and up to 30% of the affected males have intellectual disability. We describe two patients, mother and daughter, manifesting Nance-Horan syndrome. The cytogenetic and molecular analyses demonstrated a 46,X,t(X;1)(p22.13;q22) karyotype in each of them. No copy-number genomic imbalances were detected by high-density microarray analysis. The mother had a preferential inactivation of the normal X chromosome; expression analysis did not detect any mRNA isoform of NHS. This is the first report of Nance-Horan syndrome due to a skewed X chromosome inactivation resulting from a balanced translocation t(X;1) that disrupts the NHS gene expression, with important implications for clinical presentation and genetic counseling.

  8. On the Evolution of the Inner Disk Radius with Flux in the Neutron Star Low-mass X-Ray Binary Serpens X-1

    Science.gov (United States)

    Chiang, Chia - Ying; Morgan, Robert A.; Cackett, Edward M.; Miller, Jon M.; Bhattacharyya, Sudip; Strohmayer, Tod E.

    2016-01-01

    We analyze the latest Suzaku observation of the bright neutron star (NS) low-mass X-ray binary Serpens X-1 taken in 2013 October and 2014 April. The observation was taken using the burst mode and only suffered mild pile-up effects. A broad iron line is clearly detected in the X-ray spectrum. We test different models and find that the iron line is asymmetric and best interpreted by relativistic reflection. The relativistically broadened iron line is generally believed to originate from the innermost regions of the accretion disk, where strong gravity causes a series of special and general relativistic effects. The iron line profile indicates an inner radius of approx. 8 R(sub G), which gives an upper limit on the size of the NS. The asymmetric iron line has been observed in a number of previous observations, which gives several inner radius measurements at different flux states. We find that the inner radius of Serpens X-1 does not evolve significantly over the range of L/L(sub Edd) approx. 0.4-0.6, and the lack of flux dependence of the inner radius implies that the accretion disk may be truncated outside of the innermost stable circular orbit by the boundary layer, rather than the stellar magnetic field.

  9. Balloon observation of the binary X-ray source Her X-1 1.24 sec pulsation and cyclotron line emission

    International Nuclear Information System (INIS)

    Pietsch, W.; Reppin, C.; Truemper, J.; Voges, W.; Kendziorra, E.; Staubert, R.; Tuebingen Univ.

    1978-01-01

    During a balloon observation from Palestine, Texas, the authors detected for the first time the 1.24 sec pulsation of Hercules X-1 in the hard X-ray range up to 70 keV and discovered strong line emission in its spectrum at 58 keV. They estimated a line flux of 3x10 -3 photons cm -2 sec -1 and a line width of less than 12 keV. The phenomenon is interpreted as electron cyclotron emission at the basic frequency emitted by the hot polar plasma of the rotating neutron star. The line measured leads to a magnetic field strength of 5.3x10 12 gauss. In further observations during a balloon campaign in Sept./Oct. 1977 the authors confirmed the existence of the line emission and for the first time found pulsed X-ray emission above 15 keV during the 'short on' - and 'off'-state of the Her X-1 35 day cycle. The pulse to interpulse ratio seems to vary with the 35 day phase

  10. ON THE EVOLUTION OF THE INNER DISK RADIUS WITH FLUX IN THE NEUTRON STAR LOW-MASS X-RAY BINARY SERPENS X-1

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Chia-Ying; Morgan, Robert A.; Cackett, Edward M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock, Detroit, MI 48202 (United States); Miller, Jon M. [Department of Astronomy, The University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1046 (United States); Bhattacharyya, Sudip [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Strohmayer, Tod E., E-mail: ft8320@wayne.edu [X-Ray Astrophysics Lab, Astrophysics Science Division, NASA’s Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-11-01

    We analyze the latest Suzaku observation of the bright neutron star (NS) low-mass X-ray binary Serpens X-1 taken in 2013 October and 2014 April. The observation was taken using the burst mode and only suffered mild pile-up effects. A broad iron line is clearly detected in the X-ray spectrum. We test different models and find that the iron line is asymmetric and best interpreted by relativistic reflection. The relativistically broadened iron line is generally believed to originate from the innermost regions of the accretion disk, where strong gravity causes a series of special and general relativistic effects. The iron line profile indicates an inner radius of ∼8 R {sub G}, which gives an upper limit on the size of the NS. The asymmetric iron line has been observed in a number of previous observations, which gives several inner radius measurements at different flux states. We find that the inner radius of Serpens X-1 does not evolve significantly over the range of L / L {sub Edd} ∼ 0.4–0.6, and the lack of flux dependence of the inner radius implies that the accretion disk may be truncated outside of the innermost stable circular orbit by the boundary layer, rather than the stellar magnetic field.

  11. A TEST OF THE NATURE OF THE FE K LINE IN THE NEUTRON STAR LOW-MASS X-RAY BINARY SERPENS X-1

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Chia-Ying; Cackett, Edward M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock, Detroit, MI 48202 (United States); Miller, Jon M. [Department of Astronomy, The University of Michigan, 500 Church Street, Ann Arbor, MI48109-1046 (United States); Barret, Didier [Universite de Toulouse, UPS-OMP, Toulouse (France); Fabian, Andy C.; Parker, Michael L. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); D’Aì, Antonino [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Bhattacharyya, Sudip [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Burderi, Luciano [Dipartimento di Fisica, Università degli Studi di Cagliari, SP Monserrato-Sestu, KM 0.7, I-09042 Monserrato (Italy); Salvo, Tiziana Di; Iaria, Rosario [Dipartimento di Fisica e Chimica, Universitá di Palermo, via Archirafi 36, I-90123 Palermo (Italy); Egron, Elise [INAF-Osservatorio Astronomico di Cagliari, via della Scienza 5, I-09047 Selargius (Italy); Homan, Jeroen [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue 37-582D, Cambridge, MA 02139 (United States); Lin, Dacheng [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Miller, M. Coleman, E-mail: ft8320@wayne.edu [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742-2421 (United States)

    2016-04-20

    Broad Fe K emission lines have been widely observed in the X-ray spectra of black hole systems as well as in neutron star systems. The intrinsically narrow Fe K fluorescent line is generally believed to be part of the reflection spectrum originating in an illuminated accretion disk which is broadened by strong relativistic effects. However, the nature of the lines in neutron star low-mass X-ray binaries (LMXBs) has been a matter of debate. We therefore obtained the longest, high-resolution X-ray spectrum of a neutron star LMXB to date with a 300 ks Chandra High Energy Transmission Grating Spectrometer (HETGS) observation of Serpens X-1. The observation was taken under the “continuous clocking” mode, and thus was free of photon pile-up effects. We carry out a systematic analysis and find that the blurred reflection model fits the Fe line of Serpens X-1 significantly better than a broad Gaussian component does, implying that the relativistic reflection scenario is much preferred. Chandra HETGS also provides a highest spectral resolution view of the Fe K region and we find no strong evidence for additional narrow lines.

  12. INTEGRAL SPI Observations of Cygnus X-1 in the Soft State: What about the Jet Contribution in Hard X-Rays?

    Science.gov (United States)

    Jourdain, E.; Roques, J. P.; Chauvin, M.

    2014-07-01

    During the first 7 yr of the INTEGRAL mission (2003-2009), Cyg X-1 has essentially been detected in its hard state (HS), with some incursions in intermediate HSs. This long, spectrally stable period allowed in particular the measurement of the polarization of the high-energy component that has long been observed above 200 keV in this peculiar object. This result strongly suggests that here we see the contribution of the jet, known to emit a strong synchrotron radio emission. In 2010 June, Cyg X-1 underwent a completed transition toward a soft state (SS). It gave us the unique opportunity to study in detail the corona emission in this spectral state, and to investigate in particular the behavior of the jet contribution. Indeed, during the SS, the hard X-ray emission decreases drastically, with its maximum energy shifted toward lower energy and its flux divided by a factor of ~5-10. Interestingly, the radio emission follows a similar drop, supporting the correlation between the jet emission and the hard component, even though the flux is too low to quantify the polarization characteristics. Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain, and Switzerland), the Czech Republic and Poland with the participation of Russia and USA.

  13. Structure and magnetic properties of Gd2Co17-xCr x (1.17 ≤ x ≤ 3.0) compounds

    International Nuclear Information System (INIS)

    Fuquan, B.; Tegus, O.; Dagula, W.; Brueck, E.; Klaasse, J.C.P.; Buschow, K.H.J.

    2007-01-01

    The structure and magnetic properties of Gd 2 Co 17-x Cr x (1.17 ≤ x ≤ 3.0) compounds have been investigated by means of X-ray diffraction (XRD) and magnetization measurements. The powder X-ray diffraction patterns show that all samples crystallize as a single phase with the rhombohedral Th 2 Zn 17 -type structure. The lattice parameters a and the unit cell volume V increases slightly with increasing Cr content, but the c parameter varies in a less simple way with increasing Cr content. The X-ray diffraction patterns of the magnetically aligned samples show that all compounds investigated have uniaxial anisotropy. Spin reorientation phenomena occur in all of the compounds. The Curie temperature T C , the spin reorientation temperature T sr , the spontaneous magnetization M 0 and the saturation magnetization M s decrease with the increasing Cr content. The anisotropy constant K 1 and the anisotropy field B a of the compounds at room temperature reach a maximum for x = 1.76. The M 0 and M s increase with increasing temperature from 5 K to 300 K. The easy-axis anisotropy of all compounds changes to easy-plane anisotropy at low temperatures and the spin reorientation phenomena are more pronounced for low Cr concentration

  14. Evaluation of the difference in the rate coefficients of F2 + NOx (x = 1 or 2) → F + FNOx by the stereochemical arrangement using the density functional theory.

    Science.gov (United States)

    Tajima, Satomi; Hayashi, Toshio; Hori, Masaru

    2015-02-26

    The rate coefficient of F2 + NO → F + FNO is 2 to 5 orders of magnitude higher than that of F2 + NO2 → F + FNO2 even though bond energies of FNO and FNO2 only differ by ∼0.2 eV. To understand the cause of having different rate coefficients of these two reactions, the change in total energies was calculated by varying the stereochemical arrangement of F2 with respect to NOx (x = 1 or 2) by the density functional theory (DFT), using CAM-B3LYP/6-311 G+(d) in the Gaussian program. The permitted approaching angle between the x-axis and the plane consisting of O, N, F, and ϕ plays a key role to restrict the reaction of NO2 and F2 compared to the reaction of NO and F2. This restriction in the reaction space is considered to be the main cause of different rate coefficients depending on the selection of x = 1 or 2 of the reaction of F2 + NOx → F + FNOx, which was also confirmed by the difference in Si etch rate using the F formed by those reactions.

  15. Pretransplant mobilization with granulocyte colony-stimulating factor improves B-cell reconstitution by lentiviral vector gene therapy in SCID-X1 mice.

    Science.gov (United States)

    Huston, Marshall W; Riegman, Adriaan R A; Yadak, Rana; van Helsdingen, Yvette; de Boer, Helen; van Til, Niek P; Wagemaker, Gerard

    2014-10-01

    Hematopoietic stem cell (HSC) gene therapy is a demonstrated effective treatment for X-linked severe combined immunodeficiency (SCID-X1), but B-cell reconstitution and function has been deficient in many of the gene therapy treated patients. Cytoreductive preconditioning is known to improve HSC engraftment, but in general it is not considered for SCID-X1 since the poor health of most of these patients at diagnosis and the risk of toxicity preclude the conditioning used in standard bone marrow stem cell transplantation. We hypothesized that mobilization of HSC by granulocyte colony-stimulating factor (G-CSF) should create temporary space in bone marrow niches to improve engraftment and thereby B-cell reconstitution. In the present pilot study supplementing our earlier preclinical evaluation (Huston et al., 2011), Il2rg(-/-) mice pretreated with G-CSF were transplanted with wild-type lineage negative (Lin(-)) cells or Il2rg(-/-) Lin(-) cells transduced with therapeutic IL2RG lentiviral vectors. Mice were monitored for reconstitution of lymphocyte populations, level of donor cell chimerism, and antibody responses as compared to 2 Gy total body irradiation (TBI), previously found effective in promoting B-cell reconstitution. The results demonstrate that G-CSF promotes B-cell reconstitution similar to low-dose TBI and provides proof of principle for an alternative approach to improve efficacy of gene therapy in SCID patients without adverse effects associated with cytoreductive conditioning.

  16. Learning Problems

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Learning Problems KidsHealth / For Kids / Learning Problems What's in ... for how to make it better. What Are Learning Disabilities? Learning disabilities aren't contagious, but they ...

  17. The structure and band gap design of high Si doping level Ag1−xGa1−xSixSe2 (x=1/2)

    International Nuclear Information System (INIS)

    Zhang, Shiyan; Mei, Dajiang; Du, Xin; Lin, Zheshuai; Zhong, Junbo; Wu, Yuandong; Xu, Jingli

    2016-01-01

    Ag 1−x Ga 1−x Si x Se 2 solutions with high Si doping level (x=1/2) are considered and new compound AgGaSiSe 4 has been synthesized. It crystallizes in space group Aea2 and possesses very long axis of a=63.06(1)Å. The three-dimensional framework in AgGaSiSe 4 is composed of AgSe 3 trigonal planar units, AgSe 4 tetrahedra and MSe 4 (M=Si, Ga) tetrahedra. AgGaSiSe 4 is a congruently melting compound with the melt temperature of 759 °C. The diffuse reflectance measurements reveal the band gap of 2.63 eV in AgGaSiSe 4 and the value is 0.33 eV larger than that of Ag 3 Ga 3 SiSe 8 (2.30 eV). - Graphical abstract: The Ag 1−x Ga 1−x Si x Se 2 with high Si doping level (x=1/2) has been studied and the new compound AgGaSiSe 4 was synthesized for the first time. AgGaSiSe 4 crystallizes in a new structure type in space group Aea2 and adopts a three-dimensional framework consisting of AgSe 3 trigonal planar units, AgSe 4 tetrahedra and MSe 4 (M=Si, Ge) tetrahedra. Display Omitted - Highlights: • Study of Ag 1−x Ga 1−x Si x Se 2 with high Si doping level (x=1/2). • Successful synthesis of new compound named AgGaSiSe 4 . • AgGaSiSe 4 crystallizes in space group Aea2 and adopts a three-dimensional framework. • The energy band gap of AgGaSiSe 4 is enlarged compared with Ag 3 Ga 3 SiSe 8 .

  18. Defect Chemistry of a Zinc-Doped Lepidocrocite Titanate CsxTi2−x/2Znx/2O4 (x = 0.7) and its Protonic Form

    DEFF Research Database (Denmark)

    Gao, Tao; Fjellvåg, Helmer; Norby, Poul

    2009-01-01

    A zinc-doped layered titanate CsxTi2−x/2Znx/2O4 (x = 0.7) with lepidocrocite (γ-FeOOH)-type layered structure was prepared via solid-state calcination. A complete extraction of both lattice Zn atoms and interlayer Cs ions was observed upon acid exchange, producing a protonic form H2xTi2−x/2x/2O4·H2....... The protonic titanate H2xTi2−x/2x/2O4·H2O readily underwent delamination to produce its molecular single sheets Ti1−δδO24δ− (δ = 0.175) with distinctive two-dimensional morphology and small thickness (1 nm), suggesting promising applications in the assembly of functional nanostructures....

  19. Structural and thermodynamic characteristics of X2MYH2 compounds (M Al, Ga, In; X = F, Cl, Br, I; Y = N, P, As) - the products of hydrohalogen elimination from X3MYH3 donor-acceptor complexes

    International Nuclear Information System (INIS)

    Timoshkin, A.Yu.; Suvorov, A.V.; Shefer, G.F.

    2001-01-01

    Geometrical and thermodynamic characteristics of complexes X 2 MYH 2 (M Al, Ga, In; X = F, Cl, Br, I; Y = N, P, As) were obtained by the method of density functional B3LYP. It is shown that nitrogen complexes X 2 MNH 2 have a plane structure, whereas phosphorus and arsenic complexes are pyramidal. In the process of HX elimination the dissociation energy of M-Y bond is strengthened essentially (by 150-270 kJ/mol), which makes dissociation of X 2 MYH 2 into components quite inefficient from thermodynamic viewpoint even at temperatures of about 1000 deg C. Dimerization enthalpies of X 2 MYH 2 lie in the range 40 (Y = P, As) - 260 (Y=N) kJ/mol. Thus, dimers [X 2 MNH 2 ] 2 can be intermediate products in the processes of nitrides chemical precipitation from gaseous phase of donor-acceptor complexes [ru

  20. Luminescent properties of red-emitting LiSr4B3O(9−3x/2)Nx:Eu2+ phosphor for white-LEDs

    International Nuclear Information System (INIS)

    Yu Hua; Deng Degang; Xu Shiqing; Yu Cuiping; Yin Haoyong; Nie Qiulin

    2012-01-01

    An Eu 2+ -activated oxynitride LiSr (4−y) B 3 O (9−3x/2) N x :yEu 2+ red-emitting phosphor was synthesized by solid-state reactions. The synthesized phosphor crystallized in a cubic system with space group Ia–3d. The LiSr 4 B 3 O (9−3x/2) N x :Eu 2+ phosphors exhibited a broad red emission band with a peak at 610 nm and a full width at half maximum of 106 nm under 410 nm excitation, which is ascribed to the 4f 6 5d 1 →4f 7 transition of Eu 2+ . The optimal doped nitrogen concentration was observed to be x=0.75. The average decay times of two different emission centers were estimated to be 568 and 489 ns in the LiSr 3.99 B 3 O 8.25 N 0.5 :0.01Eu 2+ phosphors, respectively. Concentration quenching of Eu 2+ ions occurred at y=0.07, and the critical distance was determined as 17.86 Å. The non-radiative transitions via dipole–dipole interactions resulted in the concentration quenching of Eu 2+ -site emission centers in the LiSr 4 B 3 O 9 host. These results indicate LiSr 4 B 3 O (9−3x/2) N x :Eu 2+ phosphor is promising for application in white near-UV LEDs. - Highlights: ► An oxynitride LiSr 4 B 3 O 9 N:Eu 2+ red-emitting phosphor was prepared at low synthesis temperature. ► The introduced nitrogen improved the excitation and emission intensity of the phosphor. ► The wide excitation band matches well with near-UV LED chips. ► The emission spectrum of the phosphor showed a broad full width at half maximum of about 106 nm.

  1. Distribution of the P2X2 receptor and chemical coding in ileal enteric neurons of obese male mice (ob/ob)

    Science.gov (United States)

    Mizuno, Márcia Sanae; Crisma, Amanda Rabello; Borelli, Primavera; Schäfer, Bárbara Tavares; Silveira, Mariana Póvoa; Castelucci, Patricia

    2014-01-01

    AIM: To investigate the colocalization, density and profile of neuronal areas of enteric neurons in the ileum of male obese mice. METHODS: The small intestinal samples of male mice in an obese group (OG) (C57BL/6J ob/ob) and a control group (CG) (+/+) were used. The tissues were analyzed using a double immunostaining technique for immunoreactivity (ir) of the P2X2 receptor, nitric oxide synthase (NOS), choline acetyl transferase (ChAT) and calretinin (Calr). Also, we investigated the density and profile of neuronal areas of the NOS-, ChAT- and Calr-ir neurons in the myenteric plexus. Myenteric neurons were labeled using an NADH-diaphorase histochemical staining method. RESULTS: The analysis demonstrated that the P2X2 receptor was expressed in the cytoplasm and in the nuclear and cytoplasmic membranes only in the CG. Neuronal density values (neuron/cm2) decreased 31% (CG: 6579 ± 837; OG: 4556 ± 407) and 16.5% (CG: 7796 ± 528; OG: 6513 ± 610) in the NOS-ir and calretinin-ir neurons in the OG, respectively (P < 0.05). Density of ChAT-ir (CG: 6200 ± 310; OG: 8125 ± 749) neurons significantly increased 31% in the OG (P < 0.05). Neuron size studies demonstrated that NOS, ChAT, and Calr-ir neurons did not differ significantly between the CG and OG groups. The examination of NADH-diaphorase-positive myenteric neurons revealed an overall similarity between the OG and CG. CONCLUSION: Obesity may exert its effects by promoting a decrease in P2X2 receptor expression and modifications in the density of the NOS-ir, ChAT-ir and CalR-ir myenteric neurons. PMID:25320527

  2. Atomic structure determination of InSb(100)c(4x4) and c(8x2)phases by X-ray photoelectron diffraction

    International Nuclear Information System (INIS)

    Carvalho, V.E. de; Soares, E.A.; Magalhaes, M.R.P.; Paniago, R.; Siervo, A. de; Landers, R.

    2004-01-01

    Full text: The (100) surfaces of III-V compound semiconductors exhibit a variety of surface reconstructions that have attracted a lot of attention because of their importance in both homo epitaxial and heteroepitaxial growth. In the special case of the narrow bandgap InSb compound semiconductor its potential application in high-speed electronic and optoelectronic devices has encourage many studies of its (100) surface atomic structure. Among the reconstructions presented by the InSb(100) surface two of them have received more attention, that is, the observed well-ordered In-rich c(8x2) and Sb terminated c(4x4) surfaces. The c(8x2) structure can be obtained by exposing the surface to low energy ion bombardment and annealing, whereas the c(4x4) structure involves the chemisorption of Sb onto an already Sb-terminated surface. These two structures have been studied mainly by scanning tunneling microscopy (STM) and surface X-ray diffraction (SXRD) techniques and all the proposed models are based on the occurrence of group III (and/or V) blocks of dimmers occupying sites on the top or at subsurface layer. However, there are still difficulties in determining either the exact number of atoms in each dimmer or the number of dimmers in each block. With the goal of getting a better structure determination of the InSb(100) surface phases a photoelectron diffraction experiment (XPD) was carried out at LNLS where synchrotron and Al-K α radiations have been used. In the present work, the experimental and preliminary results of structure determination for both In Sn(100)c(8x2) and InSb(100)c(4x4) phases will be presented and discussed. (author)

  3. Kinetics versus thermodynamics of the metal incorporation in molecular beam epitaxy of (InxGa1−x2O3

    Directory of Open Access Journals (Sweden)

    Patrick Vogt

    2016-08-01

    Full Text Available We present a detailed study of the reaction kinetics and thermodynamics of the plasma-assisted oxide molecular beam epitaxy of the ternary compound (InxGa1−x2O3 for 0 ≤ x ≤ 1. We measured the growth rate of the alloy in situ by laser reflectrometry as a function of growth temperature TG for different metal-to-oxygen flux ratios rMe, and nominal In concentrations xnom in the metal flux. We determined ex situ the In and Ga concentrations in the grown film by energy dispersive X-ray spectroscopy. The measured In concentration x shows a strong dependence on the growth parameters TG, rMe, and xnom whereas growth on different co-loaded substrates shows that in the macroscopic regime of ∼μm3 x does neither depend on the detailed layer crystallinity nor on crystal orientation. The data unveil that, in presence of In, Ga incorporation is kinetically limited by Ga2O desorption the same way as during Ga2O 3 growth. In contrast, In incorporation during ternary growth is thermodynamically suppressed by the presence of Ga due to stronger Ga–O bonds. Our experiments revealed that Ga adatoms decompose/etch the In–O bonds whereas In adatoms do not decompose/etch the Ga–O bonds. This result is supported by our thermochemical calculations. In addition we found that a low TG and/or excessively low rMe kinetically enables In incorporation into (InxGa1−x2O3. This study may help growing high-quality ternary compounds (InxGa1−x2O3 allowing band gap engineering over the range of 2.7–4.7 eV.

  4. X-ray structural study of Nd[N(CN)2]3x2OP(NMe2)3

    International Nuclear Information System (INIS)

    Kapshuk, A.A.; Skopenko, V.V.

    1985-01-01

    The results of X-ray structure study of Nd(N(CN) 2 ) 3 x2OP(NMe) 2 ) 3 are presented. The crystals are monoclinic: a=12,787(6), b=17.731(9), c=15.302(5) A, γ=114.84(3) deg, Z=4, sp.gr. p2 1 /n. The structure is formed of infinite corrugated netting consisting of neodymium atoms, coordinating two OP(NMe 2 ) 3 molecules, and three bidentate-bridge dicyanamide groups. Neodymium coordination number is 8, coordination polyhedron is a distorted twocapped trigonal prism. Certain aspects of crystal chemistry of dicyanamide complexes are discussed

  5. Quasiparticle mass enhancement close to the quantum critical point in BaFe2(As(1-x)P(x))2.

    Science.gov (United States)

    Walmsley, P; Putzke, C; Malone, L; Guillamón, I; Vignolles, D; Proust, C; Badoux, S; Coldea, A I; Watson, M D; Kasahara, S; Mizukami, Y; Shibauchi, T; Matsuda, Y; Carrington, A

    2013-06-21

    We report a combined study of the specific heat and de Haas-van Alphen effect in the iron-pnictide superconductor BaFe2(As(1-x)P(x))2. Our data when combined with results for the magnetic penetration depth give compelling evidence for the existence of a quantum critical point close to x=0.30 which affects the majority of the Fermi surface by enhancing the quasiparticle mass. The results show that the sharp peak in the inverse superfluid density seen in this system results from a strong increase in the quasiparticle mass at the quantum critical point.

  6. Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding

    Energy Technology Data Exchange (ETDEWEB)

    Mugarza, Aitor; Shimizu, Tomoko; Cabrera-Sanfelix, Pepa; Sanchez-Portal, Daniel; Arnau, Andres; Salmeron, Miquel

    2008-08-01

    The effect of preadsorbed oxygen on the subsequent adsorption and reactions of water on Ru(0001) has been studied using low temperature scanning tunneling microscopy and DFT calculations. Experiments were carried out for O coverages close to 0.25 ML. It was found that no dissociation of water takes place up to the desorption temperature of {approx}180-230 K. DFT calculations show that intact water on O(2x2)/Ru(0001) is {approx} 0.49 eV more stable than the dissociation products, H and OH, at their preferred fcc and top adsorption sites.

  7. Hyperfine structure of the X 2Σ+ ground state of Ca 35Cl and Ca 37Cl by molecular-beam, laser-rf double resonance

    International Nuclear Information System (INIS)

    Childs, W.J.; Cok, D.R.; Goodman, L.S.

    1982-01-01

    The hyperfine structure of the X 2 Σ + state of Ca 35 Cl and Ca 37 Cl, unresolved in previous studies, has been investigated in detail by the molecular-beam, laser-rf, double-resonance technique. Results for the spin-rotation interaction and the dipole and quadrupole hfs constants are given in the form of Dunham coefficients so that the N'' and v'' dependence of each constant can be explicitly exhibited. The results, after dividing out the purely nuclear effects, fall between the corresponding values for CaF and CaBr, as expected

  8. A 4Σ1/2-X2Π1/2 transition in the electronic spectrum of the CuS molecule

    International Nuclear Information System (INIS)

    Lefebvre, Y.; Delaval, J.M.; Schamps, J.

    1991-01-01

    The (0-0) band of a new 4 Σ 1/2 -X 2 Π 1/2 transition has been observed in the hollow cathode emission spectra of the CuS molecule. Rotational analysis provides the following molecular constants (in cm -1 ) for the D 4 Σ 1/2 state: T 0 = 23112.88; B 0 = 0.17453; p 0 = 0.858; p 0j = 3.3x10 -6 ; D 0 = 0.11x10 -6 . Pulsed dye laser fluorescence experiments confirm the general diagram of the observed CuS electronic states. (orig.)

  9. Measurement of excitation functions and isomeric ratios of the 197Au(3He,xn)200- sup(x)Tl reactions, where x=2,3 and 4

    International Nuclear Information System (INIS)

    Vinagre Filho, U.M.

    1983-01-01

    The excitation functions and isomer ratios of the 197 Au( 3 He,xn) 200- sup(x)Tl reactions, with x = 2, 3 and 4, were measured at bombarding energies in the range from 15 to 36 MeV. The measured values were compared to those obtained with the use of the statistical an hybrid modeles, calculated by the ALICE code. Best fit was achieved using the simple statistical model. The results were also compared to those found in literature for the ( 3 He,xn) and ( 4 He,xn) reactions in gold. (Author) [pt

  10. Einstein coefficients for rotational lines of the (0,0) band of the NO A2sigma(+)-X2Pi system

    Science.gov (United States)

    Reisel, John R.; Carter, Campbell D.; Laurendeau, Normand M.

    1992-01-01

    A summary of the spectroscopic equations necessary for prediction of the molecular transition energies and the Einstein A and B coefficients for rovibronic lines of the gamma(0,0) band of nitric oxide (NO) is presented. The calculated molecular transition energies are all within 0.57/cm of published experimental values; in addition, over 95 percent of the calculated energies give agreement with measured results within 0.25/cm. Einstein coefficients are calculated from the band A00 value and the known Hoenl-London factors and are tabulated for individual rovibronic transitions in the NO A2sigma(+)-X2Pi(0,0) band.

  11. The role of dysprosium on the structural and magnetic properties of (Nd_1_−_xDy_x)_2Fe_1_4B nanoparticles

    International Nuclear Information System (INIS)

    Rahimi, Hamed; Ghasemi, Ali; Mozaffarinia, Reza; Tavoosi, Majid

    2017-01-01

    In current work, Nd2Fe14B nanoparticles was synthesized by sol-gel method. Dysprosium powders were added into Nd2Fe14B nanoparticles by mechanical alloying process in order to enhancement of coercivity. The phase analysis, structure, and magnetic properties of annealed (Nd_1_−_xDy_x)_2Fe_1_4B nanoparticles with different Dy-content (x=0.1, 0.2, 0.3, 0.4, 0.5, 0.6) were investigated by employing X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, field emission scanning electron microscope, transmission electron microscope and vibrating sample magnetometer techniques. The results showed that with an increase in Dy amounts, the coercivity of particles increased from 2.9 kOe to 13.4 kOe and then decreased to 5.6 kOe. By adding an optimum amount of Dy (x=0.4), the coercivity was significantly increased from 2.9 kOe to 13.4 kOe. The average particle size of annealed (Nd_1_−_xDy_x)_2Fe_1_4B nanoparticles was below 10 nm. Magnetization reversal studies indicate that the coercivity of milled and annealed (Nd_1_−_xDy_x)_2Fe_1_4B nanoparticles is controlled by the nucleation of reversed magnetic domains. The experimental results in the angular dependence of coercivity for (Nd_1_−_xDy_x)_2Fe_1_4B permanent magnets showed that the normalized coercivity of the permanent magnets H_c(θ)/H_c(0) increases from 1 to about 1.2–1.5 with increasing θ from 0 to about π/3, for x=0.4–0.6. - Highlights: • Dy was added to Nd_2Fe_1_4B nanoparticles to improve the coercivity. • A maximum squareness ratio of 0.99 was obtained. • The average particle size decreased with an increase in Dy-content.

  12. Low Frequency Quasi-periodic Oscillations in the High-eccentric LMXB Cir X-1: Extending the WK Correlation for Z Sources

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Qingcui; Chen, Li [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Belloni, T. M. [INAF-Osservatorio Astronomico di Brera, Via E, Bianchi 46, I-23807 Merate (Italy); Qu, Jinlu, E-mail: buqc@mail.bnu.edu.cn, E-mail: tomaso.belloni@brera.inaf.it, E-mail: chenli@bnu.edu.cn, E-mail: qujl@ihep.ac.cn [Laboratory for Particle Astrophysics, CAS, Beijing 100049 (China)

    2017-06-01

    Using archival Rossi X-ray Timing Explorer ( RXTE ) data, we studied the low-frequency quasi-periodic oscillations (LFQPOs) in the neutron star low-mass X-ray binary (LMXB) Cir X-1 and examined their contribution to frequency–frequency correlations for Z sources. We also studied the orbital phase effects on the LFQPO properties and found them to be phase independent. Comparing LFQPO frequencies in different classes of LMXBs, we found that systems that show both Z and atoll states form a common track with atoll/BH sources in the so-called WK correlation, while persistent Z systems are offset by a factor of about two. We found that neither source luminosity nor mass accretion rate is related to the shift of persistent Z systems. We discuss the possibility of a misidentification of fundamental frequency for horizontal branch oscillations from persistent Z systems and interpreted the oscillations in terms of models based on relativistic precession.

  13. ACCURATE LABORATORY WAVELENGTHS OF THE e 3 Σ-(ν' = 5) - X 1 Σ+(ν'' = 0) BAND OF 12C16O

    International Nuclear Information System (INIS)

    Dickenson, G. D.; Nortje, A. C.; Steenkamp, C. M.; Rohwer, E. G.; Du Plessis, A.

    2010-01-01

    The forbidden singlet-triplet transitions of carbon monoxide (CO) are important in the interpretation of vacuum ultraviolet interstellar absorption spectra and in particular for the measurement of large CO column densities. Twenty rovibronic lines of the e 3 Σ - (ν' = 5) - X 1 Σ + (ν'' = 0) band of 12 C 16 O for which laboratory wavelengths were previously unavailable were identified in laser-induced fluorescence excitation spectra. Wavelengths were assigned to five rovibronic transitions to an average accuracy of 0.0028 A. A further 15 lines could not be fully resolved and average wavelengths were measured for these groups of closely spaced lines. A wavelength difference of 0.011 ± 0.0028 A between the measured wavelengths and the calculated wavelengths in the atlas of Eidelsberg and Rostas demonstrates the need for more experimental data on CO.

  14. Accurate Laboratory Wavelengths of the e 3 Σ-(ν' = 5) - X 1 Σ+(ν'' = 0) Band of 12C16O

    Science.gov (United States)

    Dickenson, G. D.; Nortje, A. C.; Steenkamp, C. M.; Rohwer, E. G.; Du Plessis, A.

    2010-05-01

    The forbidden singlet-triplet transitions of carbon monoxide (CO) are important in the interpretation of vacuum ultraviolet interstellar absorption spectra and in particular for the measurement of large CO column densities. Twenty rovibronic lines of the e 3Σ-(ν' = 5) - X 1Σ+(ν'' = 0) band of 12 C 16O for which laboratory wavelengths were previously unavailable were identified in laser-induced fluorescence excitation spectra. Wavelengths were assigned to five rovibronic transitions to an average accuracy of 0.0028 Å. A further 15 lines could not be fully resolved and average wavelengths were measured for these groups of closely spaced lines. A wavelength difference of 0.011 ± 0.0028 Å between the measured wavelengths and the calculated wavelengths in the atlas of Eidelsberg & Rostas demonstrates the need for more experimental data on CO.

  15. Analysis of discrete and continuous laser induced fluorescence spectra of the A 1Σsub(u)+-X 1Σsub(g)+ band system of Sr2

    International Nuclear Information System (INIS)

    Gerber, G.; Moeller, R.

    1982-01-01

    Laser induced fluorescence spectra of the gaseous Sr 2 excimer molecule have been measured. The spectra contain discrete molecular fluorescence series, regularly modulated continuous fluorescence and an unstructured continuum. Analysis of the molecular line spectra yields for the first time Dunham coefficients for the X 1 Σsub(g) + ground state and the A 1 Σsub(u) + excited state. Using the intensity distribution of the modulated continuum which is associated with bound-free transitions the repulsive potential of the ground state up to 3000 cm -1 above the dissociation limit has been determined. The unstructured continuum can be analyzed as due to two types of continuous fluorescence. The dissociation energy of Sr 2 has been determined to Dsub(e)(X) = 965 +- 45 cm -1 . (Auth.)

  16. Analysis of discrete and continuous laser induced fluorescence spectra of the A 1μ+sub(u) - X 1μ+sub(g) band system of SR2

    International Nuclear Information System (INIS)

    Gerber, G.; Moeller, R.

    1982-01-01

    Laser induced fluorescence spectra of the gaseous Sr 2 excimer molecule have been measured. The spectra contain discrete molecular fluorescence series, regularly modulated continuous fluorescence and an unstructured continuum. Analysis of the molecular line spectra yields for the first time Dunham coefficients for the X 1 μ + sub(g) ground state and the A 1 μ + sub(u) excited state. Using the intensity distribution of the modulated continuum which is associated with bound-free transitions the repulsive potential of the ground state up to 3000 cm - 1 above the dissociation limit has been determined. The unstructured continuum can be analyzed as due to two types of continuous fluorescence. The dissociation energy of Sr 2 has been determined to Dsub(e) (X) = 965 +- 45 cm - 1 . (Author)

  17. Discovery of a 7 mHz X-Ray Quasi-Periodic Oscillation from the Most Massive Stellar-Mass Black Hole IC 10 X-1

    Science.gov (United States)

    Pasham, Dheeraj R.; Strohmayer, Tod E.; Mushotzky, Richard F.

    2013-01-01

    We report the discovery with XMM-Newton of an approx.. = 7 mHz X-ray (0.3-10.0 keV) quasi-periodic oscillation (QPO) from the eclipsing, high-inclination black hole binary IC 10 X-1. The QPO is significant at >4.33 sigma confidence level and has a fractional amplitude (% rms) and a quality factor, Q is identical with nu/delta nu, of approx. = 11 and 4, respectively. The overall X-ray (0.3-10.0 keV) power spectrum in the frequency range 0.0001-0.1 Hz can be described by a power-law with an index of approx. = -2, and a QPO at 7 mHz. At frequencies approx. > 0.02 Hz there is no evidence for significant variability. The fractional amplitude (rms) of the QPO is roughly energy-independent in the energy range of 0.3-1.5 keV. Above 1.5 keV the low signal-to-noise ratio of the data does not allow us to detect the QPO. By directly comparing these properties with the wide range of QPOs currently known from accreting black hole and neutron stars, we suggest that the 7 mHz QPO of IC 10 X-1 may be linked to one of the following three categories of QPOs: (1) the "heartbeat" mHz QPOs of the black hole sources GRS 1915+105 and IGR J17091-3624, or (2) the 0.6-2.4 Hz "dipper QPOs" of high-inclination neutron star systems, or (3) the mHz QPOs of Cygnus X-3.

  18. Study on Precursor Activity of the X1.6 Flare in the Great AR 12192 with SDO , IRIS , and Hinode

    Energy Technology Data Exchange (ETDEWEB)

    Bamba, Yumi [Institute of Space and Astronautical Science (ISAS)/Japan Aerospace Exploration Agency (JAXA) 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Lee, Kyoung-Sun [National Astronomical Observatory of Japan (NAOJ) 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Imada, Shinsuke; Kusano, Kanya, E-mail: y-bamba@nagoya-u.jp [Institute for Space-Earth Environmental Research (ISEE)/Nagoya University Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan)

    2017-05-10

    The physical properties and their contribution to the onset of a solar flare are still uncleare even though chromospheric brightening is considered a precursor phenomenon of a flare. Many studies suggested that photospheric magnetic field changes cause destabilization of large-scale coronal structure. We aim to understand how a small photospheric change contributes to a flare and to reveal how the intermediary chromosphere behaves in the precursor phase. We analyzed the precursor brightening of the X1.6 flare on 2014 October 22 in the AR 12192 using the Interface Region Imaging Spectrograph ( IRIS ) and Hinode /EUV Imaging Spectrometer (EIS) data. We investigated a localized jet with the strong precursor brightening, and compared the intensity, Doppler velocity, and line width in C ii, Mg ii k, and Si iv lines by IRIS and He ii, Fe xii, and Fe xv lines by Hinode /EIS. We also analyzed the photospheric magnetic field and chromospheric/coronal structures using the Solar Dynamics Observatory ( SDO )/Helioseismic and Magnetic Imager and Atmospheric Imaging Assembly. We found a significant blueshift (∼100 km s{sup −1}), which is related to the strong precursor brightening over a characteristic magnetic field structure, and the blueshift was observed at all of the temperatures. This might indicate that the flow is accelerated by Lorentz force. Moreover, the large-scale coronal loop that connects the foot points of the flare ribbons was destabilized just after the precursor brightening with the blueshift. It suggests that magnetic reconnection locally occurred in the lower chromosphere and it triggered magnetic reconnection of the X1.6 flare in the corona.

  19. New results from Ooty EAS array for cosmic sources at PeV energies: Cygnus X-3, Crab pulsar and Sco X-1

    International Nuclear Information System (INIS)

    Tonwar, S.C.; Gupta, S.K.; Gopalakrishnan, N.V.; Rajeev, M.R.; Srivatsan, R.; Sreekantan, B.V.

    1990-01-01

    Ooty group has reported detection of a steady signal from Cyg X-3 based on observations made during 1984-86 through detection of a directional excess. Further analysis of data has revealed a significant flux enhancement during April 1986, confirming observations reported by the CYGNUS group at Los Alamos and the Baksan group. These results show conclusively that the flux from Cyg X-3 is variable over a time scale of few weeks. We also report here the details of an unusual burst from Cyg X-3, consisting of 5 showers in 13 minutes, on June 19, 1985, which shows the variability of the flux from Cyg X-3 on a much shorter time scale of few minutes. Our analysis of showers arriving from the direction of the Crab pulsar has shown only a small time-averaged excess. But these data, when folded with the Crab pulsar period, show a very significant excess at the expected phase of the optical interpulse. This is the first detection of 33 ms pulsation in the PeV energy flux from the Crab pulsar. The exact alignment of the phase of emission over nearly 20 decades of energy, from meter wavelengths to PeV, makes the Crab pulsar a really unique source to study and understand details of mechanisms for emission and acceleration of particles in compact sources. We also present here a discussion of our observations on another X-ray binary, Sco X-1. Ooty data show a very significant excess in the number of showers from the direction of Sco X-1 during a two month period in 1986, in agreement with observations reported by the Mt. Chacaltaya group. These observations establish this X-ray binary as another important source of PeV energy radiation. (orig.)

  20. Aragonite saturation state gridded to 1x1 degree latitude and longitude at depth levels of 0, 50, 100, 200, 500, 1000, 2000, 3000, and 4000 meters in the global oceans (NCEI Accession 0139360)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains gridded data of aragonite saturation state across the global oceans (spatial distributions with a resolution of 1x1 degree latitude...