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Sample records for burster lmxb xb

  1. Uhuru observations of the Norma X-ray burster

    Science.gov (United States)

    Grindlay, J.; Gursky, H.

    1976-01-01

    Four X-ray bursts consistent with a single source in Norma are reported which were discovered by reexamining Uhuru data obtained between 1970 and 1973. The temporal and spectral characteristics of the bursts are described and shown to be similar to those displayed by bursts from the globular cluster NGC 6224. An error box of the source location is given, and it is found that both the position and intensity of the four bursts are consistent with those of 10 bursts detected by the Vela satellites in 1976. It is concluded that the source is the same as that observed by the Vela and is an X-ray burster with characteristics similar to those of certain other bursters. XB 1608-52 is suggested as the designation of this burster, possible burst models are considered, and it is noted that the error box of the present source contains an identified globular cluster.

  2. A strongly truncated inner accretion disc in the Rapid Burster

    Science.gov (United States)

    van den Eijnden, J.; Bagnoli, T.; Degenaar, N.; Lohfink, A. M.; Parker, M. L.; in ‘t Zand, J. J. M.; Fabian, A. C.

    2017-03-01

    The neutron star (NS) low-mass X-ray binary (LMXB) the Rapid Burster (RB; MXB 1730-335) uniquely shows both Type I and Type II X-ray bursts. The origin of the latter is ill-understood but has been linked to magnetospheric gating of the accretion flow. We present a spectral analysis of simultaneous Swift, NuSTAR and XMM-Newton observations of the RB during its 2015 outburst. Although a broad Fe K line has been observed before, the high quality of our observations allows us to model this line using relativistic reflection models for the first time. We find that the disc is strongly truncated at 41.8^{+6.7}_{-5.3} gravitational radii (∼87 km), which supports magnetospheric Type II burst models and strongly disfavours models involving instabilities at the innermost stable circular orbit. Assuming that the RB magnetic field indeed truncates the disc, we find B = (6.2 ± 1.5) × 108 G, larger than typically inferred for NS LMXBs. In addition, we find a low inclination (i = 29° ± 2°). Finally, we comment on the origin of the Comptonized and thermal components in the RB spectrum.

  3. A strongly truncated inner accretion disk in the Rapid Burster

    CERN Document Server

    Eijnden, J van den; Degenaar, N; Lohfink, A M; Parker, M L; Zand, J J M in 't; Fabian, A C

    2016-01-01

    The neutron star (NS) low-mass X-ray binary (LMXB) the Rapid Burster (RB; MXB 1730-335) uniquely shows both Type-I and Type-II X-ray bursts. The origin of the latter is ill-understood but has been linked to magnetospheric gating of the accretion flow. We present a spectral analysis of simultaneous Swift, NuSTAR and XMM-Newton observations of the RB during its 2015 outburst. Although a broad Fe-K line has been observed before, the high quality of our observations allows us to model this line using relativistic reflection models for the first time. We find that the disk is strongly truncated at $41.8^{+6.7}_{-5.3}$ gravitational radii ($\\sim 87$ km), which supports magnetospheric Type-II burst models and strongly disfavors models involving instabilities at the innermost stable circular orbit. Assuming that the RB magnetic field indeed truncates the disk, we find $B = (6.2 \\pm 1.5) \\times 10^8$ G, larger than typically inferred for NS LMXBs. In addition, we find a low inclination ($i = 29\\pm2^{\\rm o}$). Finally,...

  4. The Optical Counterpart of the NGC 6624 X-Ray Burster

    Science.gov (United States)

    King, Ivan R.; Stanford, S. Adam

    1993-05-01

    On a pair of 30-min HST FOC images taken at 1400 Angstroms (F140W), we have identified the optical counterpart of the X-ray burster in the globular cluster NGC 6624; this object completely dominates these UV images. Its flux agrees with the UV flux seen by Rich et al. \\ (1993,ApJ,406,489) with the large aperture of IUE. In the blue (F430W) the object is at B =~ 18.6, while in the V band (F480LP) we can find no trace of it. The 1400-B color is consistent with a Rayleigh--Jeans spectrum. (For an interpretation of this radiation as X-ray energy reprocessed by the accretion disk around the LMXB and by the binary companion, see a separate paper by Arons and King at this meeting.) The X-ray source is now found to be only 0.3 arcsec from the cluster center, increasing the likelihood that the bizarre dot P of the binary is influenced by gravitational acceleration. The counterpart of the LMXB is surrounded by several brighter red giants, one only 80 mas away, so that it cannot be observed from the ground. Our new astrometry corrects the previously published positions of the cluster center and places the counterpart within 2 sigma of the X-ray position. The optical counterpart is very close to the radio position of Johnston and Kulkarni (1992,ApJL,393,L17), but that position is now recognized to refer to a coincidentally neighboring pulsar rather than to the LMXB. Further analysis of the UV light will be pursued with HST's High Speed Photometer.

  5. Measurements of accretion disc corona size in LMXB: consequences for Comptonization and LMXB models

    OpenAIRE

    M. J. Church; Balucinska-Church, M.

    2003-01-01

    We present results of measurements of the radial extent of the accretion disc corona in low mass X-ray binaries. These results prove conclusively the extended nature of the ADC, with radial extent varying from 20,000 km in the faintest sources to 700,000 km in the brightest, a substantial fraction of the accretion disc radius, typically 15%. This result rules out the Eastern model for LMXB which is extensively used, in which the Comptonizing region is a small central region. The ADC size depe...

  6. Measurements of accretion disc corona size in LMXB: consequences for Comptonization and LMXB models

    CERN Document Server

    Church, M J

    2004-01-01

    We present results of measurements of the radial extent of the accretion disc corona in low mass X-ray binaries. These results prove conclusively the extended nature of the ADC, with radial extent varying from 20,000 km in the faintest sources to 700,000 km in the brightest, a substantial fraction of the accretion disc radius, typically 15%. This result rules out the Eastern model for LMXB which is extensively used, in which the Comptonizing region is a small central region. The ADC size depends strongly on the 1 - 30 keV source luminosity via a simple relationship r_ADC = L^{0.88 +/- 0.16} (99% confidence) close to a simple proportionality. We also present limited evidence that the ADC size agrees with the Compton radius r_C, or maximum radius for hydrostatic equilibrium. The results are consistent with models in which an extended ADC is formed by illumination of the disc by the central source. The dependence on luminosity may reflect the known decrease of coronal temperature as the source luminosity increas...

  7. Timing and spectral study of XB 1254-690 using new RXTE PCA data

    CERN Document Server

    Mukherjee, Arunava; 10.1111/j.1365-2966.2010.17872.x

    2011-01-01

    We have analyzed the new Rossi X-ray Timing Explorer Proportional Counter Array data of the atoll neutron star (NS) low-mass X-ray binary (LMXB) system XB 1254-690. The colour-colour diagram shows that the source was in the high-intensity banana state. We have found two low-frequency candidate peaks with single trial significances of ~ 2.65 X 10^{-8} and ~ 7.39 X 10^{-8} in the power spectra. After taking into account the number of trials, the joint probability of appearance of these two peaks in the data set only by chance is ~ 4.5 X 10^{-4}, and hence a low-frequency QPO can be considered to be detected with a significance of ~ 4.5 X 10^{-4}, or, ~ 3.5\\sigma for the first time from this source. We have also done the first systematic X-ray spectral study of XB 1254-690, and found that, while one-component models are inadequate, three-component models are not required by the data. We have concluded that a combined broken-powerlaw and Comptonization model best describes the source continuum spectrum among 19 t...

  8. The appearance of non-spherical systems. Application to LMXB

    CERN Document Server

    Rozanska, A; Madej, J; Adhikari, T P; You, B

    2016-01-01

    We study the appearance of the neutron star - accretion disk system as seen by a distant observer in the UV/X-ray domain. The observed intensity spectra are computed assuming non-spherical geometry of the whole system, in which outgoing spectrum is not represented by the flux spectrum, the latter being valid for spherically symmetric objects. Intensity spectra of our model display double bumps in UV/X-ray energy domains. X-ray spectra of such a type were often observed in LMXB with accretion disk, ultra luminous X-ray sources, and accreting black hole systems with hot inner compact corona. Our model naturally explains high energy broadening of the disk spectrum observed in some binaries. We attempted to fit our model to X-ray data of XTE~J1709-267 from {\\it XMM-Newton}. Unfortunately, the double intensity bump predicted by our model for LMXB is located in soft X-ray domain, uncovered by existing data for this source.

  9. XMM-Newton and Chandra observations of the M31 globular cluster black hole candidate XB135: a heavyweight contender cut down to size

    CERN Document Server

    Barnard, R; Garcia, M R; Kolb, U C; Murray, S S

    2015-01-01

    CXOM31 J004252.030+413107.87 is one of the brightest X-ray sources within the D_25 region of M31, and associated with a globular cluster (GC) known as B135; we therefore call this X-ray source XB135. XB135 is a low mass X-ray binary (LMXB) that apparently exhibited hard state characteristics at 0.3--10 keV luminosities 4--6 E+38 erg/s, and the hard state is only observed below ~10% Eddington. If true, the accretor would be a high mass black hole (BH) (> ~50 M_Sun); such a BH may be formed from direct collapse of a metal-poor, high mass star, and the very low metalicity of B135 (0.015 Z_Sun) makes such a scenario plausible. We have obtained new XMM-Newton and Chandra HRC observations to shed light on the nature of this object. We find from the HRC observation that XB135 is a single point source located close to the center of B135. The new XMM-Newton spectrum is consistent with a rapidly spinning ~10--20 M_Sun BH in the steep power law or thermal dominant state, but inconsistent with the hard state that we prev...

  10. XB130: A novel adaptor protein in cancer signal transduction

    Science.gov (United States)

    ZHANG, RUIYAO; ZHANG, JINGYAO; WU, QIFEI; MENG, FANDI; LIU, CHANG

    2016-01-01

    Adaptor proteins are functional proteins that contain two or more protein-binding modules to link signaling proteins together, which affect cell growth and shape and have no enzymatic activity. The actin filament-associated protein (AFAP) family is an important member of the adaptor proteins, including AFAP1, AFAP1L1 and AFAP1L2/XB130. AFAP1 and AFAP1L1 share certain common characteristics and function as an actin-binding protein and a cSrc-activating protein. XB130 exhibits certain unique features in structure and function. The mRNA of XB130 is expressed in human spleen, thyroid, kidney, brain, lung, pancreas, liver, colon and stomach, and the most prominent disease associated with XB130 is cancer. XB130 has a controversial effect on cancer. Studies have shown that XB130 can promote cancer progression and downregulation of XB130-reduced growth of tumors derived from certain cell lines. A higher mRNA level of XB130 was shown to be associated with a better survival in non-small cell lung cancer. Previous studies have shown that XB130 can regulate cell growth, migration and invasion and possibly has the effect through the cAMP-cSrc-phosphoinositide 3-kinase/Akt pathway. Except for cancer, XB130 is also associated with other pathological or physiological procedures, such as airway repair and regeneration. PMID:26998266

  11. Neutrino production in nucleonic interactions in gamma-ray bursters

    CERN Document Server

    Koers, Hylke B J

    2008-01-01

    Neutrinos produced in gamma-ray bursters (GRBers) may provide a unique probe for the physics of these extreme astrophysical systems. Here we discuss neutrino production in inelastic neutron-proton collisions within the relativistic outflows associated with GRBers. We consider both the widely used fireball model and a recently proposed magneto-hydrodynamic (MHD) model for the GRB outflow.

  12. Production of the $X_b$ in $\\Upsilon(5S, 6S)\\to \\gamma X_b$ radiative decays

    CERN Document Server

    Wu, Qi; Shao, Fenglan; Wang, Qianwen; Wang, Ruiqin; Zhang, Yawei; Zheng, Ying

    2016-01-01

    In this work, we investigate the production of $X_b$ in the process $\\Upsilon(5S,6S)\\to \\gamma X_b$, where $X_b$ is assumed to be the counterpart of $X(3872)$ in the bottomonium sector as a $B {\\bar B}^*$ molecular state. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate their production ratios. Our results have shown that the production ratios for the $\\Upsilon(5S,6S) \\to \\gamma X_b$ are orders of $10^{-5}$ with reasonable cutoff parameter range $\\alpha \\simeq 2\\sim 3$. The sizeable production ratios may be accessible at the future experiments like forthcoming BelleII, which will provide important clues to the inner structures of the exotic state $X_b$.

  13. Robot sensor calibration: Solving AX = XB on the Euclidean group

    Energy Technology Data Exchange (ETDEWEB)

    Park, F.C.; Martin, B.J. (Univ. of California, Irvine, CA (United States). Dept. of Mechanical and Aerospace Engineering)

    1994-10-01

    The equation AX = XB on the Euclidean group arises in the problem of calibrating wrist-mounted robotic sensors. In this article the authors derive, using methods of Lie theory, a closed-form exact solution that can be visualized geometrically, and a closed-form least squares solution when A and B are measured in the presence of noise. The principal advantage of this approach, aside from its geometric appeal, is that there exists a set of canonical coordinates for the Euclidean group that leads to a particularly simple characterization of the solutions to AX = XB. The solution can be expressed explicitly and also admits a simple geometric visualization.

  14. Identification of a Likely Radio Counterpart of the Rapid Burster

    CERN Document Server

    Moore, C B; Fox, D W; Guerriero, R A; Lewin, W H G; Fender, R P; Van Paradijs, J

    1999-01-01

    We have identified a likely radio counterpart to the low-mass X-ray binary MXB 1730-335 (the Rapid Burster). The counterpart has shown 8.4 GHz radio on/off behavior correlated with the X-ray on/off behavior as observed by the RXTE/ASM during six VLA observations. The probability of an unrelated, randomly varying background source duplicating this behavior is 1--3% depending on the correlation time scale. The location of the radio source is RA 17h 33m 24.61s; Dec -33d 23' 19.8" (J2000), +/- 0.1". We do not detect 8.4 GHz radio emission coincident with type II (accretion-driven) X-ray bursts. The ratio of radio to X-ray emission during such bursts is constrained to be below the ratio observed during X-ray persistent emission at the 2.9-sigma level. Synchrotron bubble models of the radio emission can provide a reasonable fit to the full data set, collected over several outbursts, assuming that the radio evolution is the same from outburst to outburst, but given the physical constraints the emission is more likel...

  15. XB130 expression in human osteosarcoma: a clinical and experimental study.

    Science.gov (United States)

    Wang, Xiaohui; Wang, Ruiguo; Liu, Zhaolong; Hao, Fengyun; Huang, Hai; Guo, Wenchen

    2015-01-01

    Identifying prognostic factors for osteosarcoma (OS) aids in the selection of patients who require more aggressive management. XB130 is a newly characterized adaptor protein that was reported to be a prognostic factor of certain tumor types. However, the association between XB130 expression and the prognosis of OS remains unknown. In the present study, we investigated the association between XB130 expression and clinicopathologic features and prognosis in patients suffering OS, and further investigated its potential role on OS cells in vitro and vivo. A retrospective immunohistochemical study of XB130 was performed on archival formalin-fixed paraffin-embedded specimens from 60 pairs of osteosarcoma and noncancerous bone tissues, and compared the expression of XB130 with clinicopathological parameters. We then investigate the effect of XB130 sliencing on invasion in vitro and lung metastasis in vivo of the human OS cell line. Immunohistochemical assays revealed that XB130 expression in OS tissues was significantly higher than that in corresponding noncancerous bone tissues (P=0.001). In addition, high XB130 expression more frequently occurred in OS tissues with advanced clinical stage (P=0.002) and positive distant metastasis (P=0.001). Moreover, OS patients with high XB130 expression had significantly shorter overall survival and disease-free survival (both Ptreatments. Furthermore, XB130 is the potential molecular target for OS therapy.

  16. Application of the QCD light cone sum rule to tetraquarks: The strong vertices XbXbρ and XcXcρ

    Science.gov (United States)

    Agaev, S. S.; Azizi, K.; Sundu, H.

    2016-06-01

    The full version of the QCD light-cone sum rule method is applied to tetraquarks containing a single heavy b or c quark. To this end, investigations of the strong vertices XbXbρ and XcXcρ are performed, where Xb=[s u ][b ¯ d ¯ ] and Xc=[s u ][c ¯d ¯] are the exotic states built of four quarks of different flavors. The strong coupling constants GXbXbρ and GXcXcρ corresponding to these vertices are found using the ρ -meson leading- and higher-twist distribution amplitudes. In the calculations, Xb and Xc are treated as scalar bound states of a diquark and antidiquark.

  17. INTEGRAL/JEM-X detects a new outburst of the Rapid Burster (MXB 1730-335)

    NARCIS (Netherlands)

    Chevenez, J.; Kuulkers, E.; Alfonso-Garzon, J.; Beckmann, V.; Bird, T.; Brandt, S.; Del Santo, M.; Domingo, A.; Ebisawa, K.; Jonker, P.; Kretschmar, P.; Markwardt, C.; Oosterbroek, T.; Paizis, A.; Pottschmidt, K.; Sanchez-Fernández, C.; Wijnands, R.

    2013-01-01

    The neutron star X-ray transient MXB 1730-335, aka the Rapid Burster, has been detected in outburst by the JEM-X monitors onboard INTEGRAL during the Galactic Bulge monitoring (see ATel #438) observation performed on February 28th, 2013, between (UT) 14:28 and 18:10. It is detected at 25 σ in the co

  18. Search for Millisecond Periodicities in Type I X-ray Bursts of the Rapid Burster

    CERN Document Server

    Fox, D W; Rutledge, R E; Morgan, E H; Guerriero, R A; Bildsten, L; Van der Klis, M; Van Paradijs, J; Moore, C B; Dotani, T; Asai, K

    2000-01-01

    We have searched the rising portion of type I X-ray bursts observed from the Rapid Burster with the Rossi X-ray Timing Explorer for the presence of periodicities. The 95 per cent confidence upper limit on the average root-mean-square variation of near coherent pulsations with a width of 98 per cent significance) at 306.5 Hz.

  19. INTEGRAL monitoring of the X-ray burster XTE J1739-285

    DEFF Research Database (Denmark)

    Sánchez-Fernández, C.; Kuulkers, E.; Chenevez, Jérôme;

    2008-01-01

    XTE J1739-285 is a recurrent X-ray transient first discovered by INTEGRAL as an X-ray burster. We have carried out a systematic search for X-ray bursts at various levels of accretion rate onto the Neutron Star surface during the source outbursts in 2005 and 2006. A total of 25 X-ray bursts were f...

  20. XB130 translocation to microfilamentous structures mediates NNK-induced migration of human bronchial epithelial cells.

    Science.gov (United States)

    Wu, Qifei; Nadesalingam, Jeya; Moodley, Serisha; Bai, Xiaohui; Liu, Mingyao

    2015-07-20

    Cigarette smoking contributes to the pathogenesis of chronic obstructive pulmonary disease and lung cancer. Nicotine-derived nitrosamine ketone (NNK) is the most potent carcinogen among cigarette smoking components, and is known to enhance migration of cancer cells. However, the effect of NNK on normal human bronchial epithelial cells is not well studied. XB130 is a member of actin filament associated protein family and is involved in cell morphology changes, cytoskeletal rearrangement and outgrowth formation, as well as cell migration. We hypothesized that XB130 mediates NNK-induced migration of normal human bronchial epithelial cells. Our results showed that, after NNK stimulation, XB130 was translocated to the cell periphery and enriched in cell motility-associated structures, such as lamellipodia, in normal human bronchial epithelial BEAS2B cells. Moreover, overexpression of XB130 significantly enhanced NNK-induced migration, which requires both the N- and C-termini of XB130. Overexpression of XB130 enhanced NNK-induced protein tyrosine phosphorylation and promoted matrix metalloproteinase-14 translocation to cell motility-associated cellular structures after NNK stimulation. XB130-mediated NNK-induced cell migration may contribute to airway epithelial repair; however, it may also be involved in cigarette smoking-related chronic obstructive pulmonary disease and lung cancer.

  1. Bounds on Compactness for LMXB Neutron Stars from X-ray Burst Oscillations

    CERN Document Server

    Nath, N R; Swank, J H; Nath, Nitya; Strohmayer, Tod E.; Swank, Jean H.

    2001-01-01

    We have modelled X-ray burst oscillations observed with the Rossi X-ray Timing Explorer (RXTE) from two low mass X-ray binaries (LMXB): 4U 1636-53 with a frequency of 580 Hz, and 4U 1728-34 at a frequency of 363 Hz. We have computed least squares fits to the oscillations observed during the rising phase of bursts using a model which includes emission from either a single circular hot spot or a pair of circular antipodal hot spots on the surface of a neutron star. We model the spreading of the thermonuclear hot spots by assuming that the hot spot angular size grows linearly with time. We calculate the flux as a function of rotational phase from the hot spots and take into account photon deflection in the relativistic gravitational field of the neutron star assuming the exterior spacetime is the Schwarzschild metric. We find acceptable fits with our model and we use these to place constraints on the compactness of the neutron stars in these sources. For 4U 1636-53, in which detection of a 290 Hz sub-harmonic su...

  2. Dosimetric validation of the Acuros XB Advanced Dose Calculation algorithm: fundamental characterization in water

    Energy Technology Data Exchange (ETDEWEB)

    Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio; Cozzi, Luca [Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland); Mancosu, Pietro, E-mail: afc@iosi.ch [Istituto Clinico Humanitas, Radio-Oncology Department, Milan-Rozzano (Italy)

    2011-03-21

    A new algorithm, Acuros (registered) XB Advanced Dose Calculation, has been introduced by Varian Medical Systems in the Eclipse planning system for photon dose calculation in external radiotherapy. Acuros XB is based on the solution of the linear Boltzmann transport equation (LBTE). The LBTE describes the macroscopic behaviour of radiation particles as they travel through and interact with matter. The implementation of Acuros XB in Eclipse has not been assessed; therefore, it is necessary to perform these pre-clinical validation tests to determine its accuracy. This paper summarizes the results of comparisons of Acuros XB calculations against measurements and calculations performed with a previously validated dose calculation algorithm, the Anisotropic Analytical Algorithm (AAA). The tasks addressed in this paper are limited to the fundamental characterization of Acuros XB in water for simple geometries. Validation was carried out for four different beams: 6 and 15 MV beams from a Varian Clinac 2100 iX, and 6 and 10 MV 'flattening filter free' (FFF) beams from a TrueBeam linear accelerator. The TrueBeam FFF are new beams recently introduced in clinical practice on general purpose linear accelerators and have not been previously reported on. Results indicate that Acuros XB accurately reproduces measured and calculated (with AAA) data and only small deviations were observed for all the investigated quantities. In general, the overall degree of accuracy for Acuros XB in simple geometries can be stated to be within 1% for open beams and within 2% for mechanical wedges. The basic validation of the Acuros XB algorithm was therefore considered satisfactory for both conventional photon beams as well as for FFF beams of new generation linacs such as the Varian TrueBeam.

  3. Kinetic simulations of X-B and O-X-B mode conversion

    CERN Document Server

    Arefiev, A V; Köhn, A; Holzhauer, E; Shevchenko, V F; Vann, R G L

    2015-01-01

    We have performed fully-kinetic simulations of X-B and O-X-B mode conversion in one and two dimensional setups using the PIC code EPOCH. We have recovered the linear dispersion relation for electron Bernstein waves by employing relatively low amplitude incoming waves. The setups presented here can be used to study non-linear regimes of X-B and O-X-B mode conversion.

  4. XB130 deficiency enhances lipopolysaccharide-induced septic response and acute lung injury

    Science.gov (United States)

    Toba, Hiroaki; Tomankova, Tereza; Wang, Yingchun; Bai, Xiaohui; Cho, Hae-Ra; Guan, Zhehong; Adeyi, Oyedele A.; Tian, Feng; Keshavjee, Shaf; Liu, Mingyao

    2016-01-01

    XB130 is a novel oncoprotein that promotes cancer cell survival, proliferation and migration. Its physiological function in vivo is largely unknown. The objective of this study was to determine the role of XB130 in lipopolysaccharide (LPS)-induced septic responses and acute lung injury. LPS was intraperitoneally administrated to Xb130 knockout (KO) and wild type (WT) mice. There was a significant weight loss in KO mice at Day 2 and significantly higher disease scores during the 7 days of observation. The levels of tumor necrosis factor-alpha, monocyte chemoattractant protein-1, interleukin-6 and interleukin-10 in the serum were significantly higher in KO mice at Day 2. In KO mice there were a significantly higher lung injury score, higher wet/dry lung weight ratio, more apoptotic cells and less proliferative cells in the lung. Macrophage infiltration was significantly elevated in the lung of KO mice. There was significantly increased number of p-GSK-3β positive cells in KO mice, which were mainly neutrophils and macrophages. XB130 is expressed in alveolar type I and type II cells in the lung. The expression in these cells was significantly reduced after LPS challenge. XB130 deficiency delayed the recovery from systemic septic responses, and the presence of XB130 in the alveolar epithelial cells may provide protective mechanisms by reducing cell death and promoting cell proliferation, and reducing pulmonary permeability. PMID:27029000

  5. A strong variation of accretion disc corona size with Luminosity in lmxb

    Directory of Open Access Journals (Sweden)

    M. J. Church

    2004-01-01

    Full Text Available Se revisa la controversia que ha existido durante a~nos sobre la naturaleza del continuo de rayos X emitido por la binarias de rayos-X, y que ha estado polarizada entre el modelo oriental con una peque~na regi on afectada por efecto Compton rodeando el objeto compacto y otros modelos alternativos. Presentamos medidas de la extensi on radial de esta regi on ADC en binarias de rayos X de baja masa, las cuales excluyen este modelo oriental y muestran que la regi on ADC es extensa (modelo Birmingham, mostrando los tiempos de ingresos profundos de una manera concluyente que la extensi on radial de la zona ACD var a desde el 7% del radio del disco de acreci on en fuentes d ebiles, hasta el 65% en fuentes brillantes. Hay que se~nalar que el tama~no depende fuertemente de la luminosidad de la fuente, lo cual sugiere que la zona ADC se forma por irradiaci on del disco por la estrella de neutrones y el disco interno caliente. Estos resultados tienen implicaciones fundamentales para la correcta descripci on del proceso de \\Comptonizaci on" en las binarias de rayos X, la cual di ere sustancialmente de la del modelo oriental. Las medidas de las temperaturas electr onicas de la ADC nos proporcionan valores del radio de Compton en buena consonancia con los valores medidos de la extensi on radial de la ADC. Finalmente, mostramos que los resultados son inconsistentes con una emisi on no t ermica producida en un \\jet" y por tanto proporcionan evidencia en contra de la reciente sugerencia de que todos los LMXB tienen \\jets".

  6. INTEGRAL high-energy monitoring of the X-ray burster KS 1741-293

    Science.gov (United States)

    De Cesare, G.; Bazzano, A.; Martínez Núñez, S.; Stratta, G.; Tarana, A.; Del Santo, M.; Ubertini, P.

    2007-09-01

    KS 1741-293, discovered in 1989 by the X-ray camera TTM on the Kvant module of the Mir space station and identified as an X-ray burster, had not been detected in the hard X-ray band until the advent of the INTEGRAL observatory. Moreover, this source has recently been the object of scientific discussion, being also associated with a nearby extended radio source that in principle could be the supernova remnant produced by the accretion-induced collapse in the binary system. Our long-term monitoring with INTEGRAL, covering the period from 2003 February to 2005 May, confirms that KS 1741-293 is transient in the soft and hard X-ray bands. When the source is active, from a simultaneous JEM-X and IBIS data analysis, we provide a wide-band spectrum from 5 to 100 keV, which can be fitted by a two-component model: a multiple blackbody for the soft emission and a Comptonized or a cut-off power-law model for the hard component. Finally, by the detection of two X-ray bursters with JEM-X, we confirm the bursting nature of KS 1741-293, including this source in the class of hard-tailed X-ray bursters. Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), the Czech Republic and Poland, and with the participation of Russia and the USA. E-mail: giovanni.decesare@iasf-roma.inaf.it ‡ INAF personnel resident at ASDC.

  7. Discovery of hard X-ray emission from Type II bursts of the Rapid Burster

    CERN Document Server

    Frontera, F; Orlandini, M; Amati, L; Palazzi, E; Dal Fiume, D; Del Sordo, S; Cusumano, G; Parmar, A N; Pareschi, G; Lapidus, I; Stella, L

    2000-01-01

    We report on results of BeppoSAX Target Of Opportunity (TOO) observations of the source MXB 1730-335, also called the Rapid Burster (RB), made during its outburst of February-March 1998. We monitored the evolution of the spectral properties of the RB from the outburst decay to quiescence. During the first TOO, the X-ray light curve of the RB showed many Type II bursts and its broadband (1-100 keV) spectrum was acceptably fit with a two blackbody plus power law model. Moreover, to our knowledge, this is the first time that this source is detected beyond 30 keV.

  8. Burst-only sources: probing type I X-ray bursters at low persistent luminosities

    Energy Technology Data Exchange (ETDEWEB)

    Cornelisse, R.; Zand, J.J.M. in ' t; Kuulkers, E.; Heise, J.; Verbunt, F.; Cocchi, M.; Bazzano, A.; Natalucci, L.; Ubertini, P

    2004-06-01

    The Wide Field Cameras onboard BeppoSAX observed 9 type I X-ray bursters without detectable persistent emission around the burst. According to the standard theory of X-ray bursts these sources should be in the lowest mass-accretion regime, opening the possibility to study this regime for the first time. We compare the sources with the burst theory, and show that the evidence of a new sub-class of low mass X-ray binaries, the burst-only source, is still meagre.

  9. Hard X-ray Tail Discovered in the Clocked Burster GS 1826-238

    CERN Document Server

    Rodi, James; Roques, Jean-Pierre

    2015-01-01

    The LMXB NS GS 1826-238 was discovered by Ginga in 1988 September. Due to the presence of quasi-periodicity in the type I X-ray burst rate, the source has been a frequent target of X-ray observations for almost 30 years. Though the bursts were too soft to be detected by INTEGRAL/SPI, the persistent emission from GS 1826-238 was detected over 150 keV during the ~10 years of observations. Spectral analysis found a significant high-energy excess above a Comptonization model that is well fit by a power law, indicating an additional spectral component. Most previously reported spectra with hard tails in LMXB NS have had an electron temperature of a few keV and a hard tail dominating above ~50 keV with an index of \\Gamma ~ 2-3. GS 1826-238 was found to have a markedly different spectrum with $ kT_e \\sim 20 $ keV and a hard tail dominating above ~150 keV with an index of \\Gamma ~ 1.8, more similar to BHXRB. We report on our search for long-term spectral variability over the 25-370 keV energy range and on a compariso...

  10. INTEGRAL high energy monitoring of the X-ray burster KS 1741-293

    CERN Document Server

    De Cesare, G; Nunez, S Martinez; Stratta, G; Tarana, A; De Santo, M; Ubertini, P

    2007-01-01

    KS 1741-293, discovered in 1989 by the X-ray camera TTM in the Kvant module of the Mir space station and identified as an X-ray burster, has not been detected in the hard X band until the advent of the INTEGRAL observatory. Moreover this source has been recently object of scientific discussion, being also associated to a nearby extended radio source that in principle could be the supernova remnant produced by the accretion induced collapse in the binary system. Our long term monitoring with INTEGRAL, covering the period from February 2003 to May 2005, confirms that KS 1741-293 is transient in soft and hard X band. When the source is active, from a simultaneous JEM-X and IBIS data analysis, we provide a wide band spectrum from 5 to 100 keV, that can be fit by a two component model, a multiple blackbody for the soft emission and a Comptonized or a cut-off power law model for the hard component. Finally, by the detection of two X-ray bursters with JEM-X, we confirm the bursting nature of KS 1741-293, including t...

  11. X-ray bursters and the X-ray sources of the galactic bulge

    Science.gov (United States)

    Lewin, W. H. G.; Joss, P. C.

    1981-01-01

    An attempt is made to distill from observational and theoretical information on the galactic bulge X-ray sources in general, and on the X-ray burst sources in particular, those aspects which seem to have the greatest relevance to the understanding of these sources. Galactic bulge sources appear to be collapsed objects of roughly solar mass, in most cases neutron stars, which are accreting matter from low-mass stellar companions. Type I bursts seem to result from thermonuclear flashes in the surface layers of some of these neutron stars, while the type II bursts from the Rapid Burster are almost certainly due to an instability in the accretion flow onto a neutron star. It is concluded that the studies cited offer a new and powerful observational handle on the fundamental properties of neutron stars and of the interacting binary systems in which they are often contained.

  12. VizieR Online Data Catalog: Models of thermonuclear X-ray bursters (Lampe+, 2016)

    Science.gov (United States)

    Lampe, N.; Heger, A.; Galloway, D. K.

    2016-05-01

    Using the KEPLER 1D hydrodynamics code (Woosley et al. 2004ApJS..151...75W), 464 models of thermonuclear X-ray bursters were performed across a range of accretion rates and compositions. We present the library of simulated burst profiles from this sample, and examine variations in the simulated light curve for different model conditions. We find that the recurrence time varies as a power law against accretion rate, and measure its slope while mixed H/He burning is occurring for a range of metallicities, finding the power law gradient to vary from {eta}=1.1 to 1.24. We identify the accretion rates at which mixed H/He burning stops and a transition occurs to different burning regimes. We explore how varying the accretion rate and metallicity affects burst morphology in both the rise and tail. (1 data file).

  13. Spike-adding in parabolic bursters: The role of folded-saddle canards

    Science.gov (United States)

    Desroches, Mathieu; Krupa, Martin; Rodrigues, Serafim

    2016-09-01

    The present work develops a new approach to studying parabolic bursting, and also proposes a novel four-dimensional canonical and polynomial-based parabolic burster. In addition to this new polynomial system, we also consider the conductance-based model of the Aplysia R15 neuron known as the Plant model, and a reduction of this prototypical biophysical parabolic burster to three variables, including one phase variable, namely the Baer-Rinzel-Carillo (BRC) phase model. Revisiting these models from the perspective of slow-fast dynamics reveals that the number of spikes per burst may vary upon parameter changes, however the spike-adding process occurs in an explosive fashion that involves special solutions called canards. This spike-adding canard explosion phenomenon is analysed by using tools from geometric singular perturbation theory in tandem with numerical bifurcation techniques. We find that the bifurcation structure persists across all considered systems, that is, spikes within the burst are incremented via the crossing of an excitability threshold given by a particular type of canard orbit, namely the true canard of a folded-saddle singularity. However there can be a difference in the spike-adding transitions in parameter space from one case to another, according to whether the process is continuous or discontinuous, which depends upon the geometry of the folded-saddle canard. Using these findings, we construct a new polynomial approximation of the Plant model, which retains all the key elements for parabolic bursting, including the spike-adding transitions mediated by folded-saddle canards. Finally, we briefly investigate the presence of spike-adding via canards in planar phase models of parabolic bursting, namely the theta model by Ermentrout and Kopell.

  14. 解矩阵方程AX+YB=D与AX+XB=D的迭代方法%The Iterative Solutions to Matrix Equations AX+YB=D and AX+XB=D

    Institute of Scientific and Technical Information of China (English)

    杨震; 司步文

    2001-01-01

    主要研究了解矩阵方程AX+YB=D与AX+XB=D的一种迭代方法,得到了一类矩阵方程的解法.%The least square method is used to get the solutions to the matrix equations AX+YB=D and AX+XB=D, and a series of solutions to matrix equations are offered.

  15. The X-ray Spectrum of the Rapid Burster using the Chandra HETGS

    CERN Document Server

    Marshall, H L; Fox, D; Miller, J M; Guerriero, R; Morgan, E; Van der Klis, M; Bildsten, L; Dotani, T; Lewin, W H G

    2001-01-01

    We present observations of the Rapid Burster (RB, also known as MXB 1730-335) using the Chandra High Energy Transmission Grating Spectrometer. The average interval between type II (accretion) bursts was about 40 s. There was one type I (thermonuclear flash) burst and about 20 "mini-bursts" which are probably type II bursts whose peak flux is 10-40% of the average peak flux of the other type II bursts. The time averaged spectra of the type II bursts are well fit by a blackbody with a temperature of kT = 1.6 keV, a radius of 8.9 km for a distance of 8.6 kpc, and an interstellar column density of 1.7e22 per sq. cm. No narrow emission or absorption lines were clearly detected. The 3 sigma upper limits to the equivalent widths of any features are < 10 eV in the 1.1-7.0 keV band and as small as 1.5 eV near 1.7 keV. We suggest that Comptonization destroys absorption features such as the resonance line of Fe XXVI.

  16. A population study of type II bursts in the Rapid Burster

    CERN Document Server

    Bagnoli, T; D'Angelo, C R; Galloway, D K

    2015-01-01

    Type II bursts are thought to arise from instabilities in the accretion flow onto a neutron star in an X-ray binary. Despite having been known for almost 40 years, no model can yet satisfactorily account for all their properties. To shed light on the nature of this phenomenon and provide a reference for future theoretical work, we study the entire sample of Rossi X-ray Timing Explorer data of type II bursts from the Rapid Burster (MXB 1730-335). We find that type II bursts are Eddington-limited in flux, that a larger amount of energy goes in the bursts than in the persistent emission, that type II bursts can be as short as 0.130 s, and that the distribution of recurrence times drops abruptly below 15-18 s. We highlight the complicated feedback between type II bursts and the NS surface thermonuclear explosions known as type I bursts, and between type II bursts and the persistent emission. We review a number of models for type II bursts. While no model can reproduce all the observed burst properties and explain...

  17. DIAGNOSING THE BURST INFLUENCE ON ACCRETION IN THE CLOCKED BURSTER GS 1826-238

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Long; Zhang, Shu; Chen, YuPeng; Zhang, Shuang-Nan; Chang, Zhi [Laboratory for Particle Astrophysics, Institute of High Energy Physics, Beijing 100049 (China); Torres, Diego F. [Institució Catalana de Recerca i Estudis Avançats (ICREA), E-08010 Barcelona (Spain); Kretschmar, Peter; Kuulkers, Erik [European Space Astronomy Centre (ESA/ESAC), Science Operations Department, Villanueva de la Cañada (Madrid) (Spain); Li, Jian [Institute of Space Sciences (CSIC–IEEC), Campus UAB, Carrer de Can Magrans, s/n E-08193, Barcelona (Spain)

    2015-06-10

    Type I X-ray bursts on the surface of a neutron star are a unique probe into accretion in X-ray binary systems. However, we know little about the feedback of the burst emission on accretion. Hard X-ray shortages and enhancements of the persistent emission at soft X-rays have been observed. To put these findings in context with the aim of understanding the possible mechanism underneath, we investigated 68 bursts seen by the Rossi X-ray Timing Explorer from the clocked burster GS 1826-238. We diagnosed jointly the burst influence of both soft and hard X-rays, and we found that the observations can be described by the CompTT model with variable normalization, electron temperature, and optical depth. Putting these results in a scenario of coronal Compton cooling via the burst emission would lead to a shortage of cooling power, which may suggest that additional considerations, like the influence of the burst on corona formation, should be accounted for as well.

  18. The INTEGRAL long monitoring of persistent Ultra Compact X-ray Bursters

    CERN Document Server

    Fiocchi, M; Ubertini, P; Bird, A J; Natalucci, L; Sguera, V

    2008-01-01

    The combination of compact objects, short period variability and peculiar chemical composition of the Ultra Compact X-ray Binaries make up a very interesting laboratory to study accretion processes and thermonuclear burning on the neutron star surface. The improved large optical telescopes and more sensitive X-ray satellites have increased the number of known Ultra Compact X-ray Binaries allowing their study with unprecedented detail. We analyze the average properties common to all ultra compact Bursters observed by INTEGRAL from ~0.2keV to ~150keV. We have performed a systematic analysis of the INTEGRAL public data and Key-Program proprietary observations of a sample of the Ultra Compact X-ray Binaries. In order to study their average properties in a very broad energy band, we combined INTEGRAL with BeppoSAX and SWIFT data whenever possible. For sources not showing any significant flux variations along the INTEGRAL monitoring, we build the average spectrum by combining all available data; in the case of vari...

  19. High-resolution X-ray spectroscopy of the ultracompact LMXB pulsar 4U 1626-67

    CERN Document Server

    Krauss, M I; Chakraborty, D; Juett, A M; Cottam, J; Krauss, Miriam I.; Schulz, Norbert S.; Chakrabarty, Deepto; Juett, Adrienne M.; Cottam, Jean

    2006-01-01

    [abridged] We report results from four recent observations of the ultracompact LMXB pulsar 4U 1626-67. All the observations obtained high-resolution X-ray spectra of the system, two from the Chandra X-ray Observatory using the HETGS, and two from the XMM-Newton Observatory using the RGS as well as the EPIC PN and MOS. These data allow us to study in detail the prominent Ne and O emission line complexes which make 4U 1626-67 unique among LMXBs. The observations were spaced over a period of 3 years for a total observing time of 238 ks, allowing us to monitor the line regions as well as the overall source flux, continuum spectrum, and timing properties. The structure of the emission lines and the ratios of the components of the helium-like Ne IX and O VII triplets support the hypothesis that they are formed in the high-density environment of the accretion disk. We do not find any significant changes in the line widths or ratios over this time period, though we note that the line equivalent widths decrease. We ar...

  20. INTEGRAL/JEM-X detects a new outburst of the Rapid Burster (MXB 1730-335)

    Science.gov (United States)

    Chenevez, J.; Kuulkers, E.; Alfonso-Garzon, J.; Beckmann, V.; Bird, T.; Brandt, S.; Del Santo, M.; Domingo, A.; Ebisawa, K.; Jonker, P.; Kretschmar, P.; Markwardt, C.; Oosterbroek, T.; Paizis, A.; Pottschmidt, K.; Sanchez-Fernández, C.; Wijnands, R.

    2013-03-01

    The neutron star X-ray transient MXB 1730-335, aka the Rapid Burster, has been detected in outburst by the JEM-X monitors onboard INTEGRAL during the Galactic Bulge monitoring (see ATel #438) observation performed on February 28th, 2013, between (UT) 14:28 and 18:10. It is detected at 25 σ in the combined JEM-X mosaic with an effective exposure time of 2 ksec, and the measured fluxes are the following: 170 ±6 mCrab (2.9e-9 erg/cm2/s) in the 3-10 keV energy band, 122 ±13 mCrab (1.5e-9 erg/cm2/s) in the 10-25 keV energy band. The source is not visible in the IBIS/ISGRI camera with flux upper limits (6 σ) of ~3 mCrab (2.9e-11 erg/cm2/s) in the 18-40 keV band, and ~10 mCrab (1.0e-10 erg/cm2/s) in the 40-100 keV band. No bursting activity is noticeable. During the previous observation of the Galactic Bulge on February 24th (see ATel #4840) the source was not detected with 5 σ upper limits of 8 mCrab (1.1e-10 erg/cm2/s) and 5 mCrab (5e-11 erg/cm2/s) in the 3-10 keV and 10-25 keV bands, respectively.

  1. 啤酒酵母XB05及其突变株JY2-2的RAPD分析%The RAPD Analysis of Brewer's Yeast XB05 and Its Mutant Strain JY2-2

    Institute of Scientific and Technical Information of China (English)

    曾婷; 刘月英

    2008-01-01

    菌株JY2-2是啤酒酵母(Saccharomyces cerevisiae)XB05经半导体激光诱变筛选得到的优良菌株.为了从分子水平考察菌株JY2-2与XB05的差异,为酵母菌株JY2-2的鉴定提供分子依据,我们运用随机扩增多态性DNA(RAPD)技术对啤酒酵母XB05和JY2-2进行全基因组分析.用27条随机引物对这两株酵母菌进行扩增,结果得到5条可产生较多扩增条带,并具有较丰富多态性的随机引物,每条引物可扩增8~20条DNA条带,分子量大小在100~3000bp之间.菌株XB05和JY2-2的DNA遗传相似系数为0.794,可以认为菌株JY2-2是啤酒酵母XB05的突变株.

  2. NuSTAR and XMM-Newton Observations of 1E1743.1-2843: Indications of a Neutron Star LMXB Nature of the Compact Object

    Science.gov (United States)

    Lotti, Simone; Natalucci, Lorenzo; Mori, Kaya; Baganoff, Frederick K.; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Hailey, Charles J.; Harrison, Fiona A.; Hong, Jaesub; Krivonos, Roman A.; Rahoui, Farid; Stern, Daniel; Tomsick, John A.; Zhang, Shuo; Zhang, William W.

    2016-05-01

    We report on the results of NuSTAR and XMM-Newton observations of the persistent X-ray source 1E1743.1-2843, located in the Galactic Center region. The source was observed between 2012 September and October by NuSTAR and XMM-Newton, providing almost simultaneous observations in the hard and soft X-ray bands. The high X-ray luminosity points to the presence of an accreting compact object. We analyze the possibilities of this accreting compact object being either a neutron star (NS) or a black hole, and conclude that the joint XMM-Newton and NuSTAR spectrum from 0.3 to 40 keV fits a blackbody spectrum with {kT}˜ 1.8 {keV} emitted from a hot spot or an equatorial strip on an NS surface. This spectrum is thermally Comptonized by electrons with {{kT}}e˜ 4.6 {keV}. Accepting this NS hypothesis, we probe the low-mass X-ray binary (LMXB) or high-mass X-ray binary (HMXB) nature of the source. While the lack of Type-I bursts can be explained in the LMXB scenario, the absence of pulsations in the 2 mHz-49 Hz frequency range, the lack of eclipses and of an IR companion, and the lack of a {K}α line from neutral or moderately ionized iron strongly disfavor interpreting this source as a HMXB. We therefore conclude that 1E1743.1-2843 is most likely an NS-LMXB located beyond the Galactic Center. There is weak statistical evidence for a soft X-ray excess which may indicate thermal emission from an accretion disk. However, the disk normalization remains unconstrained due to the high hydrogen column density ({N}{{H}}˜ 1.6× {10}23 {{cm}}-2).

  3. Six years of BeppoSAX Wide Field Cameras observations of nine galactic type-I X-ray bursters

    CERN Document Server

    Cornelisse, R; Verbunt, F; Kuulkers, E; Heise, J; Den Hartog, P R; Cocchi, M; Natalucci, L; Bazzano, A; Ubertini, P

    2003-01-01

    We present an overview of BeppoSAX Wide Field Cameras observations of the nine most frequent type-I X-ray bursters in the Galactic center region. Six years of observations (from 1996 to 2002) have amounted to 7 Ms of Galactic center observations and the detection of 1823 bursts. The 3 most frequent bursters are GX 354-0 (423 bursts), KS 1731-260 (339) and GS 1826-24 (260). These numbers reflect an unique dataset. We show that all sources have the same global burst behavior as a function of luminosity. At the lowest luminosities (L_X<=2E37 erg/s bursts occur quasi-periodically and the burst rate increases linearly with accretion rate (clear in e.g. GS 1826-24 and KS 1731-260). At L_pers=2E37 erg/s the burst rate drops by a factor of five. This corresponds to the transition from, on average, a hydrogen-rich to a pure helium environment in which the flashes originate that are responsible for the bursts. At higher luminosities the bursts recur irregularly; no bursts are observed at the highest luminosities. Ou...

  4. X-ray, radio, and infrared observations of the 'rapid burster' /MXB 1730-335/ during 1979 and 1980

    Science.gov (United States)

    Lawrence, A.; Cominsky, L.; Lewin, W. H. G.; Oda, M.; Ogawara, Y.; Inoue, H.; Koyama, K.; Makishima, K.; Matsuoka, M.; Murakami, T.

    1983-01-01

    The paper reports partially simultaneous observations of the 'rapid burster' (MXB 1730-335) at X-ray, infrared, and radio wavelengths, covering several hundred hours during 1979 and 1980. None of the authors of this report saw any infrared or radio bursts. On several occasions an absence of infrared bursting was observed during X-ray bursting. On one occasion an absence of X-ray bursting was observed during a radio burst (4.1 GHz) reported by Calla et al. (1979). To date, radio bursts (a total of at least a dozen) have been reported only by Calla et al. (1980). Considering these and other observations summarized here, the reported radio bursts are either unreal or do not bear a simple relation to the X-ray bursts from the 'rapid burster'. The status of the reported infrared bursts also remain ambiguous. Limits to the brightness of any persistent radio source at the position of MXB 1730-335, limits to persistent X-ray emission during an extended X-ray quiet phase, and a measurement of the infrared polarization in the direction of the X-ray source are also reported.

  5. Probing the MSP Prenatal Stage: The Optical Identification of the X-Ray Burster EXO 1745-248 in Terzan 5

    NARCIS (Netherlands)

    Ferraro, F. R.; Pallanca, C.; Lanzoni, B.; Cadelano, M.; Massari, D.; Dalessandro, E.; Mucciarelli, A.

    2015-01-01

    We report on the optical identification of the neutron star burster EXO 1745-248 in Terzan 5. The identification was performed by exploiting Hubble Space Telescope/Advanced Camera for Surveys images acquired in Director's Discretionary Time shortly after (approximately one month) the Swift detection

  6. KiloHertz QPO and Gravitational Wave Emission as the Signature of the Rotation and Precession of a LMXB Neutron Star Near Breakup

    CERN Document Server

    Jernigan, J G

    2001-01-01

    The basic theory of torque free precession (TFP) of the outer crust of a neutron star (NS) as the signature of the approach to NS breakup is a viable explanation of the uniform properties of kHz Quasi-periodic Oscillations (QPO) observed in X-rays emitted by Low Mass X-ray Binary (LMXB) sources. The theory outlined in this paper relates the intrinsic properties of NS structure to the observed kHz frequencies. The range of kHz frequencies and the observed quality factors (Qs) are also explained by this simple dynamical model. A scenario that begins with the melting of the inner crust of an LMXB NS creates the conditions necessary for the generation of kHz QPO. The theory relates the ratio of the observed kHz frequencies to the ratios of the components of the moments of inertia of the NS, thereby tightly constraining the equation of state (EOS) of NS matter (polytrope index ~1.0). The TFP model is in strong contrast to existing models which primarily relate the kHz QPO phenomenon to the physics of gas dynamics ...

  7. NuSTAR and XMM-Newton observations of 1E1743.1-2843: indications of a neutron star LMXB nature of the compact object

    CERN Document Server

    Lotti, Simone; Mori, Kaya; Baganoff, Frederick K; Boggs, Steven E; Christensen, Finn E; Craig, William W; Hailey, Charles J; Harrison, Fiona A; Hong, Jaesub; Krivonos, Roman A; Rahoui, Farid; Stern, Daniel; Tomsick, John A; Zhang, Shuo; Zhang, William W

    2016-01-01

    We report on the results of NuSTAR and XMM-Newton observations of the persistent X-ray source \\object{1E1743.1-2843}, located in the Galactic Center region. The source was observed between September and October 2012 by NuSTAR and XMM-Newton, providing almost simultaneous observations in the hard and soft X-ray bands. The high X-ray luminosity points to the presence of an accreting compact object. We analyze the possibilities of this accreting compact object being either a neutron star (NS) or a black hole, and conclude that the joint XMM-Newton and NuSTAR spectrum from 0.3 to 40 $\\mathrm{keV}$ fits to a black body spectrum with $kT\\sim1.8~\\mathrm{keV}$ emitted from a hot spot or an equatorial strip on a neutron star surface. This spectrum is thermally Comptonized by electrons with $kT_{e}\\sim4.6~\\mathrm{keV}$. Accepting this neutron star hypothesis, we probe the Low Mass (LMXB) or High Mass (HMXB) X-ray Binary nature of the source. While the lack of Type-I bursts can be explained in the LMXB scenario, the abs...

  8. Magnetization of mixed ferri-ferrimagnets composed of Prussian blue analogs A1xA21-xB

    Institute of Scientific and Technical Information of China (English)

    Jiang Wei; Guan Hong-Yu; Lo Weng-Cheng

    2011-01-01

    The magnetization of ternary metal Prussian blue analogues A1xA21-xB, formed by three different sublattices A1, A2 and B, is studied by using the effective-field theory with self-spin correlations. Effects of the mole fraction x,the anisotropy and the transverse magnetic field on the magnetization are discussed.

  9. Measured Sonic Boom Signatures Above and Below the XB-70 Airplane Flying at Mach 1.5 and 37,000 Feet

    Science.gov (United States)

    Maglieri, Domenic J.; Henderson, Herbert R.; Tinetti, Ana F.

    2011-01-01

    During the 1966-67 Edwards Air Force Base (EAFB) National Sonic Boom Evaluation Program, a series of in-flight flow-field measurements were made above and below the USAF XB-70 using an instrumented NASA F-104 aircraft with a specially designed nose probe. These were accomplished in the three XB-70 flights at about Mach 1.5 at about 37,000 ft. and gross weights of about 350,000 lbs. Six supersonic passes with the F-104 probe aircraft were made through the XB-70 shock flow-field; one above and five below the XB-70. Separation distances ranged from about 3000 ft. above and 7000 ft. to the side of the XB-70 and about 2000 ft. and 5000 ft. below the XB-70. Complex near-field "sawtooth-type" signatures were observed in all cases. At ground level, the XB-70 shock waves had not coalesced into the two-shock classical sonic boom N-wave signature, but contained three shocks. Included in this report is a description of the generating and probe airplanes, the in-flight and ground pressure measuring instrumentation, the flight test procedure and aircraft positioning, surface and upper air weather observations, and the six in-flight pressure signatures from the three flights.

  10. The origin of the n-type behavior in rare earth borocarbide Y1-xB28.5C4.

    Science.gov (United States)

    Mori, Takao; Nishimura, Toshiyuki; Schnelle, Walter; Burkhardt, Ulrich; Grin, Yuri

    2014-10-28

    Synthesis conditions, morphology, and thermoelectric properties of Y1-xB28.5C4 were investigated. Y1-xB28.5C4 is the compound with the lowest metal content in a series of homologous rare earth borocarbonitrides, which have been attracting interest as high temperature thermoelectric materials because they can embody the long-awaited counterpart to boron carbide, one of the few thermoelectric materials with a history of commercialization. It was revealed that the presence of boron carbide inclusions was the origin of the p-type behavior previously observed for Y1-xB28.5C4 in contrast to Y1-xB15.5CN and Y1-xB22C2N. In comparison with that of previous small flux-grown single crystals, a metal-poor composition of YB40C6 (Y0.71B28.5C4) in the synthesis successfully yielded sintered bulk Y1-xB28.5C4 samples apparently free of boron carbide inclusions. "Pure" Y1-xB28.5C4 was found to exhibit the same attractive n-type behavior as the other rare earth borocarbonitrides even though it is the most metal-poor compound among the series. Calculations of the electronic structure were carried out for Y1-xB28.5C4 as a representative of the series of homologous compounds and reveal a pseudo gap-like electronic density of states near the Fermi level mainly originating from the covalent borocarbonitride network.

  11. The investigation of hardness and bonding behavior in XB4, X = {Ce, Th, U, Pa}, tetraborides by first-principles

    OpenAIRE

    ÖZCAN, Sezgin AYDIN and Aynur

    2010-01-01

    The mechanical and electronic properties of XB4, X = {Ce, Th, U, Pa}, tetraborides have been studied by using first-principles based on density functional theory. The results show that these boron-rich solids are mechanically and thermodynamically stable. From the calculated band structure and density of states, we obtained that they have metallic character. When the calculated parameters related to the crystal structure were considered with the bonding characteristics, the microsco...

  12. Four-quark structure of Zc(3900), Z(4430) and Xb(5568) states

    CERN Document Server

    Goerke, Fabian; Ivanov, Mikhail A; Korner, Jurgen G; Lyubovitskij, Valery E; Santorelli, Pietro

    2016-01-01

    We examine the four-quark structure of the recently discovered charged $Z_c(3900)$, $Z(4430)$ and $X_b(5568)$ states. We calculate the widths of the strong decays $Z_c^+ \\to J/\\psi \\pi^+$ ($\\eta_c\\rho^+$, $\\bar D^0D^{\\ast\\,+}$, $\\bar D^{\\ast\\,0}D^+$), $Z(4430)^+ \\to J/\\psi \\pi^+$ ($\\psi(2s) \\pi^+$), and $X^+_b\\to B_s\\pi^+$ within a covariant quark model previously developed by us. We find that the tetraquark-type current widely used in the literature for the $Z_c(3900)$ leads to a significant suppression of the $\\bar D D^\\ast$ and $\\bar D^\\ast D$ modes. Contrary to this a molecular-type current provides an enhancement by a factor of 6-7 for the $\\bar D D^\\ast$ modes compared with the $Z_c^+\\to J/\\psi\\pi^+$, $\\eta_c\\rho^+$ modes in agreement with recent experimental data from the BESIII Collaboration. In case of $Z(4430)$ state we test a sensitivity of the ratio $R_Z$ of the $Z(4430)^+ \\to \\psi(2s) \\pi^+$ and $Z(4430)^+ \\to J/\\psi \\pi^+$ decay rates to a choice of the size parameter $\\Lambda_{Z(4430)}$ of the ...

  13. Synthesis, thermionic emission and magnetic properties of (NdxGd1-x)B6

    Institute of Scientific and Technical Information of China (English)

    Bao Li-Hong; Zhang Jiu-Xing; Zhou Shen-Lin; Tegus

    2011-01-01

    Polycrystalline rare-earth hexaborides (NdxGd1-x)B6 (x = 0, 0.2, 0.6, 0.8, 1) were prepared by the reactive spark plasma sintering (SPS) method using mixed powder of GdH2, NdH2 and B. The effects of Nd doping on the crystal structure, the grain orientation, the thermionic emission and the magnetic properties of the hexaboride were investigated by X-ray diffraction, electron backscattered diffraction and magnetic measurements. It is found that all the samples sintered by the SPS method exhibit high densities (> 95%) and high values of Vickers hardness (2319 kg/mm2). The values are much higher than those obtained in the traditional method. With the increase of Nd content, the thermionic emission current density increases from 11 to 16.30 A/cm2 and the magnetic phase transition temperature increases from 5.85 to 7.95 K. Thus, the SPS technique is a suitable method to synthesize the dense rare-earth hexaborides with excellent properties.

  14. Results of INTEGRAL TOO observation of the transient X-ray burster XTE J1810-189

    CERN Document Server

    Chelovekov, I

    2010-01-01

    We report results of the INTEGRAL Target of Opportunity observations of the transient X-ray burster XTE J1810-189. The observations were performed on April 3--6, 2008, soon after the discovery of the source and near the peak of its outburst. That time the source had a flux of about 50 mCrab and exhibited a hard Comptonized X-ray spectrum extending well above 100 keV. Being approximated by a power law with an exponetial cut-off in the broad 3--100 keV energy band it gave the average photon index $\\Gamma\\simeq 1.6$ and $kT_{cutoff}\\simeq 67$ keV. We found only slight indications for changes in the index during the observation ($\\Gamma$ first steady decreased from $\\sim 2.0$ to $\\sim1.3$ and then increased back to $\\sim 2.0$). However the $N_{\\rmn H}$ value measured by absorption in the low energy part of the spectrum changed drastically and very irregularly (from $\\sim 4\\times 10^{22}$ till $\\sim 100\\times 10^{22}$ cm$^{-2}$). There were 10 type I X-ray bursts detected from the source during these TOO observati...

  15. Hard X-rays from Type II bursts of the Rapid Burster and its transition toward quiescence

    CERN Document Server

    Masetti, N; Stella, L; Orlandini, M; Parmar, A N; Del Sordo, S; Amati, L; Palazzi, E; Dal Fiume, D; Cusumano, G; Pareschi, G; Lapidus, I; Remillard, R A

    2000-01-01

    We report on 4 BeppoSAX Target Of Opportunity observations of MXB 1730-335, the Rapid Burster (RB), made during the 1998 February-March outburst. In the first observation, approximately 20 days after the outburst peak, the X-ray light curve showed Type II bursts at a rate of 43 per hour. Nine days later, during the second BeppoSAX pointing, only 5 Type II bursts were detected at the beginning of the observation. During the third pointing no X-ray bursts were detected and in the fourth and final observation the RB was not detected at all. Persistent emission from the RB was detected up to 10 keV during the first three pointings. The spectra of the persistent and bursting emissions below 10 keV were best fit with a model consisting of two blackbodies. An additional component (a power law) was needed to describe the 1-100 keV bursting spectrum when the persistent emission was subtracted. To our knowledge, this is the first detection of the RB beyond 20 keV. We discuss the evolution of the spectral parameters for...

  16. Broadband observations of the X-ray burster 4U 1705-44 with BeppoSAX

    CERN Document Server

    Piraino, S; Mueck, B; Kaaret, P; Di Salvo, T; D'Ai, A; Iaria, R; Egron, E

    2016-01-01

    4U 1705-44 is one of the most-studied type I X-ray burster and Atoll sources. This source represents a perfect candidate to test different models proposed to self-consistently track the physical changes occurring between different spectral states because it shows clear spectral state transitions. The broadband coverage, the sensitivity and energy resolution of the BeppoSAX satellite offers the opportunity to disentangle the components that form the total X-ray spectrum and to study their changes according to the spectral state. Using two BeppoSAX observations carried out in August and October 2000, respectively, for a total effective exposure time of about 100 ks, we study the spectral evolution of the source from a soft to hard state. Energy spectra are selected according to the source position in the color-color diagram (CCD) Results. We succeeded in modeling the spectra of the source using a physical self-consistent scenario for both the island and banana branches (the double Comptonization scenario). The ...

  17. Efficient syntheses of 5-X-B(10)H(13) Halodecaboranes via the photochemical (X = I) and/or base-catalyzed (X = Cl, Br, I) isomerization reactions of 6-X-B(10)H(13).

    Science.gov (United States)

    Ewing, William C; Carroll, Patrick J; Sneddon, Larry G

    2010-02-15

    High yield syntheses of the 5-X-B(10)H(13) (5X) halodecaboranes have been achieved through the photochemical (X = I) or base-catalyzed (X = Cl, Br, I) isomerization reactions of their 6-X-B(10)H(13) (6X) isomers. 5I was obtained in 80% isolated yield upon the UV photolysis of 6I. Treatment of 6X (X = Cl, Br, I) with catalytic amounts of triethylamine at 60 degrees C led to the formation of 78:22 (Cl), 82:18 (Br), and 86:14 (I) ratio 5X/6X equilibrium mixtures. The 5X isomers were then separated from these mixtures by selective crystallization (Br and I) or column chromatography (Cl), with the supernatant mixtures in each case then subjected to another round of isomerization/separation to harvest a second crop of 5X. The combined isolated yields of pure products after two cycles were 71% 5-Cl-B(10)H(13), 83% 5-Br-B(10)H(13), and 68% 5-I-B(10)H(13). The previously proposed structures of 5-Br-B(10)H(13) and 5-I-B(10)H(13) were crystallographically confirmed. Deprotonation of 6X and 5X with 1,8-bis(dimethylamino)naphthalene (PS) resulted in the formation of [PSH(+)][6X(-)] and [PSH(+)][5X(-)]. Density functional theory-gauge-independent atomic orbital (DFT/GIAO) calculations and crystallographic determinations of [PSH(+)][6Cl(-)] and [PSH(+)][6Cl(-)] confirmed bridge-deprotonation at a site adjacent to the halogen-substituted borons. NMR studies of the 6-Br-B(10)H(13) isomerization induced by stoichiometric amounts of PS showed that following initial deprotonation to form 6-Br-B(10)H(12)(-), isomerization occurred at 60 degrees C to form an equilibrium mixture of 6-Br-B(10)H(12)(-) and 5-Br-B(10)H(12)(-). DFT calculations also showed that the observed 5-X-B(10)H(13)/6-X-B(10)H(13) equilibrium ratios in the triethylamine-catalyzed reactions were consistent with the energetic differences of the 5-X-B(10)H(12)(-) and 6-X-B(10)H(12)(-) anions. These results strongly support a mechanistic pathway for the base-catalyzed 6X to 5X conversions involving the formation and

  18. Dosimetric impact of Acuros XB dose calculation algorithm in prostate cancer treatment using RapidArc

    Directory of Open Access Journals (Sweden)

    Suresh Rana

    2013-01-01

    Full Text Available Purpose: The purpose of this study is to assess the dosimetric impact of Acuros XB dose calculation algorithm (AXB, in comparisons with Anisotropic Analytical Algorithm (AAA calculations in prostate cancer treatment using RapidArc. Materials and Methods: A computed tomography (CT dataset of low-risk prostate cancer patients treated at Arizona Center for Cancer Care was selected and contoured for prostate, seminal vesicles, and organs at risk (OARs(rectum, bladder, and femur heads. Plans were created for 6 MV photon beam using RapidArc technique in Eclipse treatment planning system. Dose calculations were performed with AAA and AXB for same number of monitor units and identical beam setup. Mean and maximum doses to planning target volume (PTV and OARs were analyzed. Additionally, minimum dose to PTV and V100 was analyzed. Finally, point-dose difference between planar dose distributions of AAA and AXB plans was investigated. Results: The highest dose difference was up to 0.43% (range: 0.05−0.43%, P> 0.05 for PTV and 1.98% (range: 0.22−1.98%, P> 0.05 for OARs with AAA predicting higher dose than AXB. The V100 values of AAA plans (95 % and AXB plans (range: 93.1−97.9 % had an average difference of 0.89±1.47% with no statistical significance (P = 0.25411. The point-dose difference analysis showed that AAA predicted higher dose than AXB at significantly higher percentage (in average 94.15 of total evaluated points. Conclusion: The dosimetric results of this study suggest that the AXB can perform the dose computation comparable to AAA in RapidArc prostate cancer treatment plans that are generated by a partial single-arc technique.

  19. Dip Spectroscopy of the Low Mass X-Ray Binary XB 1254-690

    Science.gov (United States)

    Smale, Alan P.; Church, M. J.; BalucinskaChurch, M.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We observed the low mass X-ray binary XB 1254-690 with the Rossi X-ray Timing Explorer in 2001 May and December. During the first observation strong dipping on the 3.9-hr orbital period and a high degree of variability were observed, along with "shoulders" approx. 15% deep during extended intervals on each side of the main dips. The first observation also included pronounced flaring activity. The non-dip spectrum obtained using the PCA instrument was well-described by a two-component model consisting of a blackbody with kT = 1.30 +/- 0.10 keV plus a cut-off power law representation of Comptonized emission with power law photon index 1.10 +/- 0.46 and a cut-off energy of 5.9(sup +3.0, sub -1.4) keV. The intensity decrease in the shoulders of dipping is energy-independent, consistent with electron scattering in the outer ionized regions of the absorber. In deep dipping the depth of dipping reached 100%, in the energy band below 5 keV, indicating that all emitting regions were covered by absorber. Intensity-selected dip spectra were well-fit by a model in which the point-like blackbody is rapidly covered, while the extended Comptonized emission is progressively overlapped by the absorber, with the, covering fraction rising to 95% in the deepest portion of the dip. The intensity of this component in the dip spectra could be modeled by a combination of electron scattering and photoelectric absorption. Dipping did not occur during the 2001 December observation, but remarkably, both bursting and flaring were observed contemporaneously.

  20. Effect of Acuros XB algorithm on monitor units for stereotactic body radiotherapy planning of lung cancer.

    Science.gov (United States)

    Khan, Rao F; Villarreal-Barajas, Eduardo; Lau, Harold; Liu, Hong-Wei

    2014-01-01

    Stereotactic body radiotherapy (SBRT) is a curative regimen that uses hypofractionated radiation-absorbed dose to achieve a high degree of local control in early stage non-small cell lung cancer (NSCLC). In the presence of heterogeneities, the dose calculation for the lungs becomes challenging. We have evaluated the dosimetric effect of the recently introduced advanced dose-calculation algorithm, Acuros XB (AXB), for SBRT of NSCLC. A total of 97 patients with early-stage lung cancer who underwent SBRT at our cancer center during last 4 years were included. Initial clinical plans were created in Aria Eclipse version 8.9 or prior, using 6 to 10 fields with 6-MV beams, and dose was calculated using the anisotropic analytic algorithm (AAA) as implemented in Eclipse treatment planning system. The clinical plans were recalculated in Aria Eclipse 11.0.21 using both AAA and AXB algorithms. Both sets of plans were normalized to the same prescription point at the center of mass of the target. A secondary monitor unit (MU) calculation was performed using commercial program RadCalc for all of the fields. For the planning target volumes ranging from 19 to 375cm(3), a comparison of MUs was performed for both set of algorithms on field and plan basis. In total, variation of MUs for 677 treatment fields was investigated in terms of equivalent depth and the equivalent square of the field. Overall, MUs required by AXB to deliver the prescribed dose are on an average 2% higher than AAA. Using a 2-tailed paired t-test, the MUs from the 2 algorithms were found to be significantly different (p algorithms.

  1. An adequate interpretation of charge transport for a dilute La 1-xCe xB 6 system

    Science.gov (United States)

    Sluchanko, N. E.; Glushkov, V. V.; Demishev, S. V.; Samarin, N. A.; Bogach, A. V.; Gon'kov, K. V.; Khayrullin, E. I.; Filipov, V. B.; Shitsevalova, N. Yu.

    2008-04-01

    Precision measurements of charge transport characteristics (resistivity and Seebeck coefficient) have been carried out on the high quality single crystals of the so-called dilute Kondo system La 1-xCe xB 6 ( x⩽0.1) in a wide temperature range 1.8-300 K. At low temperatures, it was shown that instead of Kondo-type logarithmic contribution to resistivity Δ ρ∼-ln T the magnetic component obeys the power law Δ ρ∼ T-a, which corresponds to the regime of weak localization of charge carriers with the critical exponent values a=0.47-0.49 for x⩽0.1. An asymptotic behavior of Seebeck coefficient S∼-ln T found for these dilute magnetic compounds at intermediate temperatures is compared with S( T) dependence observed for the dense system CeB 6. The data obtained for La 1-xCe xB 6 are analyzed in terms of Kondo-impurity model and alternative spin-polaron approach.

  2. Dosimetric comparison of Acuros XB, AAA, and XVMC in stereotactic body radiotherapy for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tsuruta, Yusuke; Nakata, Manabu; Higashimura, Kyoji [Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto 606-8507 (Japan); Nakamura, Mitsuhiro, E-mail: m-nkmr@kuhp.kyoto-u.ac.jp; Matsuo, Yukinori; Monzen, Hajime; Mizowaki, Takashi; Hiraoka, Masahiro [Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507 (Japan)

    2014-08-15

    Purpose: To compare the dosimetric performance of Acuros XB (AXB), anisotropic analytical algorithm (AAA), and x-ray voxel Monte Carlo (XVMC) in heterogeneous phantoms and lung stereotactic body radiotherapy (SBRT) plans. Methods: Water- and lung-equivalent phantoms were combined to evaluate the percentage depth dose and dose profile. The radiation treatment machine Novalis (BrainLab AG, Feldkirchen, Germany) with an x-ray beam energy of 6 MV was used to calculate the doses in the composite phantom at a source-to-surface distance of 100 cm with a gantry angle of 0°. Subsequently, the clinical lung SBRT plans for the 26 consecutive patients were transferred from the iPlan (ver. 4.1; BrainLab AG) to the Eclipse treatment planning systems (ver. 11.0.3; Varian Medical Systems, Palo Alto, CA). The doses were then recalculated with AXB and AAA while maintaining the XVMC-calculated monitor units and beam arrangement. Then the dose-volumetric data obtained using the three different radiation dose calculation algorithms were compared. Results: The results from AXB and XVMC agreed with measurements within ±3.0% for the lung-equivalent phantom with a 6 × 6 cm{sup 2} field size, whereas AAA values were higher than measurements in the heterogeneous zone and near the boundary, with the greatest difference being 4.1%. AXB and XVMC agreed well with measurements in terms of the profile shape at the boundary of the heterogeneous zone. For the lung SBRT plans, AXB yielded lower values than XVMC in terms of the maximum doses of ITV and PTV; however, the differences were within ±3.0%. In addition to the dose-volumetric data, the dose distribution analysis showed that AXB yielded dose distribution calculations that were closer to those with XVMC than did AAA. Means ± standard deviation of the computation time was 221.6 ± 53.1 s (range, 124–358 s), 66.1 ± 16.0 s (range, 42–94 s), and 6.7 ± 1.1 s (range, 5–9 s) for XVMC, AXB, and AAA, respectively. Conclusions: In the

  3. The {P,Q,k+1}-Reflexive Solution to System of Matrix Equations AX=C, XB=D

    Directory of Open Access Journals (Sweden)

    Chang-Zhou Dong

    2015-01-01

    Full Text Available Let P∈Cm×m and Q∈Cn×n be Hermitian and {k+1}-potent matrices; that is, Pk+1=P=P⁎ and Qk+1=Q=Q⁎, where ·⁎ stands for the conjugate transpose of a matrix. A matrix X∈Cm×n is called {P,Q,k+1}-reflexive (antireflexive if PXQ=X (PXQ=-X. In this paper, the system of matrix equations AX=C and XB=D subject to {P,Q,k+1}-reflexive and antireflexive constraints is studied by converting into two simpler cases: k=1 and k=2. We give the solvability conditions and the general solution to this system; in addition, the least squares solution is derived; finally, the associated optimal approximation problem for a given matrix is considered.

  4. Contribution to thermochemical studies of 0.8[xB2O3-(1-x)SiO2]-0.2Na2O glasses

    Institute of Scientific and Technical Information of China (English)

    A.E Ahoussou; J.Rogez; A.Yapi; V.Mikalean; A.Kone

    2009-01-01

    Calorimetric measurements in 0.8[xB2O3-(1-x)SiO2]-0.2Na2O glasses and melts are performed in HF calorimetry at 298 K and lead borate calorimetry at 973 K,respectively.Mixing enthalpy is affected by both temperature and composition.At 298 K,the mixing enthalpies are slightly negative and components are miscible at that temperature in the whole composition range.At 973 K,the sign of the mixing enthalpies reflect the tendency to phase separation at silica-rich compositions,which is avoided for kinetic reasons as shown by SEM results.Therefore,one is tempted to consider the quenched 0.8[xB2O3-(1-x)SiO2-0.20Na2O]glasses and melts as single-phase materials.

  5. Genetic diversity of VAR2CSA ID1-DBL2Xb in worldwide Plasmodium falciparum populations: impact on vaccine design for placental malaria.

    Science.gov (United States)

    Bordbar, Bita; Tuikue Ndam, Nicaise; Renard, Emmanuelle; Jafari-Guemouri, Sayeh; Tavul, Livingstone; Jennison, Charlie; Gnidehou, Sédami; Tahar, Rachida; Gamboa, Dionicia; Bendezu, Jorge; Menard, Didier; Barry, Alyssa E; Deloron, Philippe; Sabbagh, Audrey

    2014-07-01

    In placental malaria (PM), sequestration of infected erythrocytes in the placenta is mediated by an interaction between VAR2CSA, a Plasmodium falciparum protein expressed on erythrocytes, and chondroitin sulfate A (CSA) on syncytiotrophoblasts. Recent works have identified ID1-DBL2Xb as the minimal CSA-binding region within VAR2CSA able to induce strong protective immunity, making it the leading candidate for the development of a vaccine against PM. Assessing the existence of population differences in the distribution of ID1-DBL2Xb polymorphisms is of paramount importance to determine whether geographic diversity must be considered when designing a candidate vaccine based on this fragment. In this study, we examined patterns of sequence variation of ID1-DBL2Xb in a large collection of P. falciparum field isolates (n=247) from different malaria-endemic areas, including Africa (Benin, Senegal, Cameroon and Madagascar), Asia (Cambodia), Oceania (Papua New Guinea), and Latin America (Peru). Detection of variants and estimation of their allele frequencies were performed using next-generation sequencing of DNA pools. A considerable amount of variation was detected along the whole gene segment, suggesting that several allelic variants may need to be included in a candidate vaccine to achieve broad population coverage. However, most sequence variants were common and extensively shared among worldwide parasite populations, demonstrating long term persistence of those polymorphisms, probably maintained through balancing selection. Therefore, a vaccine mixture including such stable antigen variants will be putatively applicable and efficacious in all world regions where malaria occurs. Despite similarity in ID1-DBL2Xb allele repertoire across geographic areas, several peaks of strong population differentiation were observed at specific polymorphic loci, pointing out putative targets of humoral immunity subject to positive immune selection.

  6. Nanocomposite Nd10Fe84-xB6Inx (x=0, 1) Permanent Magnet and Its Heat-treatment Behavior

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Nanocomposite magnet of Nd10Fe84-xB6lnx (x=0,1) has been fabricated and magnetic properties have been in vestigated. Addition of indium damages the magnetic behavior, but can change its heat-treatment effect. Annealing does not improve the properties very much to the In-free magnet, but changes the intrinsic coercivity of Nd10Fe83B6ln obviously.

  7. Strong electron-phonon coupling in Be{1-x}B{2}C{2}: ab initio studies

    Science.gov (United States)

    Moudden, A. H.

    2008-07-01

    Several structures for off-stoichiometric beryllium diboride dicarbide Be{1-x}B2C2 have been designed, and their properties studied from first-principles density functional methods. Among the most stable phases examined, the layered hexagonal structures are shown to exhibit various features in the electronic properties and in the lattice dynamics reminiscent of the superconducting magnesium diboride and alkaline earth-intercalated graphites. For substoichiometric composition x˜ 1/3, the system is found metallic with a moderately strong electron-phonon coupling through a predominant contribution arising from high frequency streching modes modulating the σ-bonding of the B C network, and a weaker contribution at medium frequency range of the phonon spectra, arising from the intercalent motion coupled to the π-bonding states. Further, anharmonicities emerging from the proximity of the Fermi level to the σ-band edge, contributes to reduce the phonon softening hence stabilizing the structure. All these effects appear to combine favourably to produce a high temperature phonon-superconductivity.

  8. An X-ray study of the dipping low mass X-ray binary XB 1323-619

    CERN Document Server

    Balucinska-Church, M; Oosterbroek, T; Segreto, A; Morley, R E; Parmar, A N

    1999-01-01

    During a BeppoSAX observation of the low-mass X-ray binary dip source XB 1323-619 a total of 10 type I X-ray bursts and parts of 12 intensity dips were observed. During non-bursting, non-dipping intervals, the 1-150 keV BeppoSAX spectrum can be modelled by a cutoff power-law with a photon index of 1.48 +/- 0.01, a cutoff energy of 44.1 +5.1/-4.4 keV together with a blackbody with kT of 1.77 +/- 0.25 keV contributing ~15% of the 2-10 keV flux. Absorption equivalent to 3.88 +/- 0.16x10^22 H atom cm^(-2) is required. The dips repeat with a period of 2.938 +/- 0.020 hr and span 40% of the orbital cycle. During dips the maximum reduction in 2-10 keV intensity is ~65%. The spectral changes during dips are complex and cannot be modelled by a simple absorber because of the clear presence of part of the non-dip spectrum which is not absorbed. Spectral evolution in dipping can be well modelled by progressive covering of the cutoff power-law component which must be extended, plus rapid absorption of the point-source bla...

  9. A Soft X-Ray Spectral Episode for the Clocked Burster, GS 1826-24 as Measured by Swift and NuSTAR

    CERN Document Server

    Chenevez, J; Zand, J J M in 't; Tomsick, J A; Barret, D; Chakrabarty, D; Fürst, F; Boggs, S E; Christensen, F E; Craig, W W; Hailey, C J; Harrison, F A; Romano, P; Stern, D; Zhang, W W

    2015-01-01

    We report on NuSTAR and Swift observations of a soft state of the neutron star low-mass X-ray binary GS 1826-24, commonly known as the "clocked" burster. The transition to the soft state was recorded in 2014 June through an increase of the 2-20 keV source intensity measured by MAXI, simultaneous with a decrease of the 15-50 keV intensity measured by Swift/BAT. The episode lasted approximately two months, after which the source returned to its usual hard state. We analyze the broad-band spectrum measured by Swift/XRT and NuSTAR, and estimate the accretion rate during the soft episode to be about 13% of Eddington, within the range of previous observations. However, the best fit spectral model, adopting the double Comptonization used previously, exhibits significantly softer components. We detect seven type-I X-ray bursts, all significantly weaker (and with shorter rise and decay times) than observed previously. The burst profiles and recurrence times vary significantly, ruling out the regular bursts that are ty...

  10. Superconducting properties of Zn and Al double-doped Mg1-x(Zn0.5Al0.5)xB2

    DEFF Research Database (Denmark)

    Xu, G.J.; Grivel, Jean-Claude; Abrahamsen, A.B.

    2004-01-01

    A series of polycrystalline samples of Mg1-x(Zn0.5Al0.5)(x)B-2 (0less than or equal toxless than or equal to0.8) were prepared by solid state reaction method and their structure, superconducting transition temperature (T-c) and transport properties were investigated by means of X-ray diffraction...... (XRD), ac susceptibility, magnetization and resistivity. The double doping leads to decreases in both the lattice parameters a and c, and the T-c decreases with increasing dopant content. A systematical comparison with Al doped- and Li, Al double doped MgB2 of structure, superconducting transition...

  11. Excitation of ion Bernstein waves as the dominant parametric decay channel in direct X-B mode conversion for typical spherical torus

    Science.gov (United States)

    Abbasi, Mustafa; Sadeghi, Yahya; Sobhanian, Samad; Asgarian, Mohammad Ali

    2016-03-01

    The electron Bernstein wave (EBW) is typically the only wave in the electron cyclotron (EC) range that can be applied in spherical tokamaks for heating and current drive (H&CD). Spherical tokamaks (STs) operate generally in high- β regimes, in which the usual EC ordinary (O) and extraordinary (X) modes are cut off. As it was recently investigated the existence of EBWs at nonlinear regime thus the next step would be the probable nonlinear phenomena study which are predicted to be occurred within the high levels of injected power. In this regard, parametric instabilities are considered as the major channels for losses at the X-B conversion. Hence, we have to consider their effects at the UHR region which can reduce the X-B conversion efficiency. In the case of EBW heating (EBH) at high power density, the nonlinear effects can arise. Particularly at the UHR position, the group velocity is strongly reduced, which creates a high energy density and subsequently a high amplitude electric field. Therefore, a part of the input wave can decay into daughter waves via parametric instability (PI). Thus, via the present research, the excitations of ion Bernstein waves as the dominant decay channels are investigated and also an estimate for the threshold power in terms of experimental parameters related to the fundamental mode of instability is proposed.

  12. Search for the $X_b$ and other hidden-beauty states in the $\\pi^+ \\pi^- \\Upsilon(1 \\rm S)$ channel at ATLAS

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Almond, John; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baas, Alessandra; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batley, Richard; Battaglia, Marco; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boddy, Christopher Richard; Boehler, Michael; Boek, Thorsten Tobias; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boutouil, Sara; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozic, Ivan; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Richard; Bressler, Shikma; Bristow, Kieran; Bristow, Timothy Michael; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Brown, Jonathan; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Buehrer, Felix; Bugge, Lars; Bugge, Magnar Kopangen; Bulekov, Oleg; Bundock, Aaron Colin; Burckhart, Helfried; Burdin, Sergey; Burghgrave, Blake; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarda, Stefano; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cano Bret, Marc; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caudron, Julien; Cavaliere, Viviana; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerio, Benjamin; Cerny, Karel; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Charfeddine, Driss; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Liming; Chen, Shenjian; Chen, Xin; Chen, Ye; Chen, Yujiao; Cheng, Hok Chuen; Cheng, Yangyang; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiefari, Giovanni; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Chouridou, Sofia; Chow, Bonnie Kar Bo; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Chwastowski, Janusz; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocio, Alessandra; Cirkovic, Predrag; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Coggeshall, James; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Colon, German; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Connell, Simon Henry; Connelly, Ian; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cooper-Smith, Neil; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cuciuc, Constantin-Mihai; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Daniells, Andrew Christopher; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Davey, Will; David, Claire; Davidek, Tomas; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Domenico, Antonio; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; Barros do Vale, Maria Aline; Do Valle Wemans, André; Dobos, Daniel; Doglioni, Caterina; Doherty, Tom; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Dubreuil, Emmanuelle; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Dwuznik, Michal; Dyndal, Mateusz; Ebke, Johannes; Edson, William; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Engelmann, Roderich; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Favareto, Andrea; Fayard, Louis; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Fernandez Perez, Sonia; Ferrag, Samir; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Adam; Fischer, Julia; Fisher, Wade Cameron; Fitzgerald, Eric Andrew; Flechl, Martin; Fleck, Ivor; Fleischmann, Philipp; Fleischmann, Sebastian; Fletcher, Gareth Thomas; Fletcher, Gregory; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Florez Bustos, Andres Carlos; Flowerdew, Michael; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Franconi, Laura; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gao, Jun; Gao, Yongsheng; Garay Walls, Francisca; Garberson, Ford; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giangiobbe, Vincent; Giannetti, Paola; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Stephen; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Filippo Maria; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giugni, Danilo; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Glonti, George; Goblirsch-Kolb, Maximilian; Goddard, Jack Robert; Godlewski, Jan; Goeringer, Christian; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabas, Herve Marie Xavier; Graber, Lars; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Grebenyuk, Oleg; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Grohs, Johannes Philipp; Grohsjean, Alexander; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Groth-Jensen, Jacob; Grout, Zara Jane; Guan, Liang; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guicheney, Christophe; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Gupta, Shaun; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guttman, Nir; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Haefner, Petra; Hageböck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Hall, David; Halladjian, Garabed; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Hanke, Paul; Hanna, Remie; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Hariri, Faten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Paul Fraser; Hartjes, Fred; Hasegawa, Makoto; Hasegawa, Satoshi; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Lukas; Hejbal, Jiri; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, James; Henderson, Robert; Heng, Yang; Hengler, Christopher; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herrberg-Schubert, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holmes, Tova Ray; Hong, Tae Min; Hooft van Huysduynen, Loek; Hopkins, Walter; Horii, Yasuyuki; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Catherine; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Xueye; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Ideal, Emma; Idrissi, Zineb; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikematsu, Katsumasa; Ikeno, Masahiro; Ilchenko, Iurii; Iliadis, Dimitrios; Ilic, Nikolina; Inamaru, Yuki; Ince, Tayfun; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Ivarsson, Jenny; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, Matthew; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Jeanty, Laura; Jejelava, Juansher; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Joergensen, Morten Dam; Johansson, Erik; Johansson, Per; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Jussel, Patrick; Juste Rozas, Aurelio; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kalderon, Charles William; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karnevskiy, Mikhail; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Katre, Akshay; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Kehoe, Robert; Keil, Markus; Keller, John; Kempster, Jacob Julian; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hee Yeun; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klioutchnikova, Tatiana; Klok, Peter; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolanoski, Hermann; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; König, Sebastian; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kreiss, Sven; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kurumida, Rie; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; La Rosa, Alessandro; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laier, Heiko; Lambourne, Luke; Lammers, Sabine; Lampen, Caleb; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire Alexandra; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leisos, Antonios; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzen, Georg; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Leontsinis, Stefanos; Leroy, Claude; Lester, Christopher; Lester, Christopher Michael; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Lei; Li, Liang; Li, Shu; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Linde, Frank; Lindquist, Brian Edward; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Brian Alexander; Long, Jonathan; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lopez Paz, Ivan; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lu, Nan; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lungwitz, Matthias; Lynn, David; Lysak, Roman; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Machado Miguens, Joana; Macina, Daniela; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeno, Mayuko; Maeno, Tadashi; Maevskiy, Artem; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Maiani, Camilla; Maidantchik, Carmen; Maier, Andreas Alexander; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mamuzic, Judita; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mantifel, Rodger; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marjanovic, Marija; Marques, Carlos; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian Thomas; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Homero; Martinez, Mario; Martin-Haugh, Stewart; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massa, Lorenzo; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazzaferro, Luca; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McPherson, Robert; Mechnich, Joerg; Medinnis, Michael; Meehan, Samuel; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Meric, Nicolas; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Milic, Adriana; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Minami, Yuto; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Mönig, Klaus; Monini, Caterina; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Klemens; Mueller, Thibaut; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagai, Yoshikazu; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Nanava, Gizo; Narayan, Rohin; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Nef, Pascal Daniel; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nuti, Francesco; O'Brien, Brendan Joseph; O'grady, Fionnbarr; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pearce, James; Pedersen, Lars Egholm; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penwell, John; Perepelitsa, Dennis; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Perrino, Roberto; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Pettersson, Nora Emilia; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pingel, Almut; Pinto, Belmiro; Pires, Sylvestre; Pitt, Michael; Pizio, Caterina; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Poddar, Sahill; Podlyski, Fabrice; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopapadaki, Eftychia-sofia; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Przysiezniak, Helenka; Ptacek, Elizabeth; Puddu, Daniele; Pueschel, Elisa; Puldon, David; Purohit, Milind; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Quarrie, David; Quayle, William; Queitsch-Maitland, Michaela; Quilty, Donnchadha; Qureshi, Anum; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Rajagopalan, Srinivasan; Rammensee, Michael; Randle-Conde, Aidan Sean; Rangel-Smith, Camila; Rao, Kanury; Rauscher, Felix; Rave, Tobias Christian; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reisin, Hernan; Relich, Matthew; Rembser, Christoph; Ren, Huan; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Ridel, Melissa; Rieck, Patrick; Rieger, Julia; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodrigues, Luis; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Matthew; Rose, Peyton; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Christian; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sacerdoti, Sabrina; Saddique, Asif; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Sauvage, Gilles; Sauvan, Emmanuel; Savard, Pierre; Savu, Dan Octavian; Sawyer, Craig; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R~Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schramm, Steven; Schreyer, Manuel; Schroeder, Christian; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Scifo, Estelle; Sciolla, Gabriella; Scott, Bill; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellers, Graham; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Serre, Thomas; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shehu, Ciwake Yusufu; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Shushkevich, Stanislav; Sicho, Petr; Sidiropoulou, Ourania; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Song, Hong Ye; Soni, Nitesh; Sood, Alexander; Sopczak, Andre; Sopko, Bruno; Sopko, Vit; Sorin, Veronica; Sosebee, Mark; Soualah, Rachik; Soueid, Paul; Soukharev, Andrey; South, David; Spagnolo, Stefania; Spanò, Francesco; Spearman, William Robert; Spettel, Fabian; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Staerz, Steffen; Stahlman, Jonathan; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Stavina, Pavel; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Svatos, Michal; Swedish, Stephen; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Taccini, Cecilia; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tannenwald, Benjamin Bordy; Tannoury, Nancy; Tapprogge, Stefan; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Ray; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Tran, Huong Lan; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ugland, Maren; Uhlenbrock, Mathias; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Unverdorben, Christopher; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloso, Filipe; Velz, Thomas; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Virzi, Joseph; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Peter; Wagner, Wolfgang; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chao; Wang, Chiho; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Xiaoxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, Alan; Wilson, John; Wingerter-Seez, Isabelle; Winklmeier, Frank; Winter, Benedict Tobias; Wittgen, Matthias; Wittig, Tobias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wright, Michael; Wu, Mengqing; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yakabe, Ryota; Yamada, Miho; Yamaguchi, Hiroshi; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Un-Ki; Yang, Yi; Yanush, Serguei; Yao, Liwen; Yao, Weiming; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yen, Andy L; Yildirim, Eda; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Yusuff, Imran; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Lei; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Lei; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Zinonos, Zinonas; Ziolkowski, Michael; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zutshi, Vishnu; Zwalinski, Lukasz

    2015-01-01

    This Letter presents a search for a hidden-beauty counterpart of the $X(3872)$ in the mass ranges 10.05--10.31 GeV and 10.40--11.00 GeV, in the channel $X_b \\to \\pi^{+} \\pi^{-} \\Upsilon(1 \\rm S)(\\rightarrow\\mu^+\\mu^-)$, using 16.2 fb$^{-1}$ of $\\sqrt{s}=8$ TeV $pp$ collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the $X_b$ cross section and branching fraction, relative to those of the $\\Upsilon(2 \\rm S)$, at the 95% confidence level using the CL$_S$ approach. These limits range from 0.8% to 4.0%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the $\\Upsilon(1^3 \\rm{D}$$_J)$, $\\Upsilon(10860)$, and $\\Upsilon(11020)$ states also reveal no significant signals.

  13. Structure and superconductivity of double-doped Mg1-x(Al0.5Li0.5)xB2

    DEFF Research Database (Denmark)

    Xu, G.J.; Grivel, Jean-Claude; Abrahamsen, A.B.;

    2003-01-01

    A series of polycrystalline samples of Mg1-x(Al0.5Li0.5)(x)B-2 (0less than or equal toxless than or equal to0.6) were prepared by a solid state reaction method and their structure, superconducting transition temperature and magneto-transport properties were investigated by means of X-ray diffract......A series of polycrystalline samples of Mg1-x(Al0.5Li0.5)(x)B-2 (0less than or equal toxless than or equal to0.6) were prepared by a solid state reaction method and their structure, superconducting transition temperature and magneto-transport properties were investigated by means of X......-ray diffraction (XRD), ac-susceptibility and resistance in varied magnetic fields. The double doping leads to decreases in both the lattice parameters a and c. The superconducting transition temperature (T-c) decreases with double doping, but the T-c is systematically higher than that of the single Al......-doped samples. It is suggested that the hole band filling has little effect on T-c at high doping level, while the disorder induced by doping plays an important role in suppressing T-c. A systematic comparison with Al-doped MgB2 of the structure, superconducting transition and irreversibility field is made. (C...

  14. 用“心”服务,一路同行--100辆东风天锦交付新邦物流%Dongfeng Deliver 100 Dongfeng KR to Guangdong XB Logistics Co., Ltd

    Institute of Scientific and Technical Information of China (English)

    窦伟杰

    2016-01-01

    Aug. 18, 2016, Dongfeng held a ceremony at Guangzhou to deliver the ifrst 100 Dongfeng KR to Guangdong province in the year of 2016. The buyer is Guangdong XB Logistic Co., Ltd who has been a loyal customer to Dongfeng. This company’s 70% of transport vehicles are purchased from Dongfeng.

  15. Structure, elastic stiffness, and hardness of Os 1- xRu xB 2 solid solution transition-metal diborides

    KAUST Repository

    Kanoun, Mohammed

    2012-05-31

    On the basis of recent experiments, the solid solution transition-metal diborides were proposed to be new ultra-incompressible hard materials. We investigate using density functional theory based methods the structural and mechanical properties, electronic structure, and hardness of Os 1-xRu xB 2 solid solutions. A difference in chemical bonding occurs between OsB 2 and RuB 2 diborides, leading to significantly different elastic properties: a large bulk, shear moduli, and hardness for Os-rich diborides and relatively small bulk, shear moduli, and hardness for Ru-rich diborides. The electronic structure and bonding characterization are also analyzed as a function of Ru-dopant concentration in the OsB 2 lattice. © 2012 American Chemical Society.

  16. Unexpected synergy between magnetic iron chains and stacked B6 rings in Nb6Fe(1-x)Ir(6+x)B8.

    Science.gov (United States)

    Mbarki, Mohammed; St Touzani, Rachid; Fokwa, Boniface P T

    2014-11-24

    The synergistic combination of experiment and density functional theory has led to the discovery of the first ferromagnetic material, Nb6Fe(1-x)Ir(6+x)B8, containing in its crystal structure iron chains embedded in stacked B6 rings. The strong ferromagnetic Fe-Fe interactions found in the iron chains induce an unexpected strengthening of the B-B interactions in the B6 rings. Beside these strong B-B interactions, strong interlayer metal-boron bonds (Ir-B and Nb-B) ensure the overall structural stability of this phase, while the magnetic Fe-Fe interactions are mainly responsible for the observed ferromagnetic ordering below T(C)=350 K.

  17. Origin of $\\gamma$ Ray Bursters

    CERN Document Server

    Mészáros, P

    1999-01-01

    The successful discovery of X-ray, optical and radio afterglows of GRB hasmade possible the identification of host galaxies at cosmological distances.The energy release inferred in these outbursts place them among the mostenergetic and violent events in the Universe. They are thought to be theoutcome of a cataclysmic stellar collapse or compact stellar merger, leading toa relativistically expanding fireball, in which particles are accelerated atshocks and produce nonthermal radiation. The substantial agreement betweenobservations and the theoretical predictions of the fireball shock modelprovide confirmation of the basic aspects of this scenario. Among recent issuesare the collimation of the outflow and its implications for the energetics, theproduction of prompt bright flashes at wavelenghts much longer than gamma-rays,the time structure of the afterglow, its dependence on the central engine orprogenitor system behavior, and the role of the environment on the afterglow.

  18. Crystal structure and magnetic properties of Ce{sub 2}Fe{sub 14−x}Co{sub x}B alloys

    Energy Technology Data Exchange (ETDEWEB)

    Skoug, Eric J.; Meyer, M.S.; Pinkerton, F.E. [Chemical and Materials Systems Laboratory, General Motors Research and Development Center, Mail Code 480-106-224, Warren, MI 48090-9055 (United States); Tessema, Misle M. [Optimal CAE, Inc., 14492 Sheldon Road, Plymouth, MI 48170 (United States); Haddad, Daad [MEDA Engineering and Technical Services, LLC, 17515 West Nine Mile Road, Southfield, MI 48075 (United States); Herbst, J.F., E-mail: jan.f.herbst@gm.com [Chemical and Materials Systems Laboratory, General Motors Research and Development Center, Mail Code 480-106-224, Warren, MI 48090-9055 (United States)

    2013-10-15

    Highlights: •Annealed melt-spun Ce{sub 3}Fe{sub 14−x}Co{sub x}B or Ce{sub 2.55}Fe{sub 14−x}Co{sub x}B{sub 1.27} ribbons maintain the Ce{sub 2}Fe{sub 14}B crystal structure only for x ⩽ 5. •In contrast to many other R{sub 2}Fe{sub 14}B materials, we find no evidence for the formation of Ce{sub 2}Co{sub 14}B. •The Curie temperature increases rapidly with increasing cobalt content x, reaching ∼660 K for x = 5. •Ce{sub 3}Fe{sub 12}Co{sub 2}B offers significant improvement in T{sub c}, B{sub r}, and (BH){sub max} relative to its Co-free analog with only modest H{sub ci} loss. -- Abstract: Permanent magnet materials based on the R{sub 2}Fe{sub 14}B phase (R = rare earth element) are essential to a wide variety of applications, among them automotive traction motors. Current state-of-the-art materials rely on R = Nd and Dy, for both of which there are supply uncertainties and rapidly rising costs. A possible alternative is R = Ce, the most abundant rare earth, but Ce{sub 2}Fe{sub 14}B has several disadvantages, including a low Curie temperature (T{sub c}) that limits its maximum operating point to well below that required for some automotive uses. Here we systematically investigate the Ce{sub 2}Fe{sub 14−x}Co{sub x}B system by exploring Co substitution for Fe in melt-spun ribbons as a means of increasing T{sub c}. In addition to T{sub c} we report the solubility of Co in Ce{sub 2}Fe{sub 14}B and its effect on the crystal structure and hard magnetic properties.

  19. SU-E-T-101: Determination and Comparison of Correction Factors Obtained for TLDs in Small Field Lung Heterogenous Phantom Using Acuros XB and EGSnrc

    Energy Technology Data Exchange (ETDEWEB)

    Soh, R [Nanyang Technological University, Singapore (Singapore); Lee, J [National Cancer Centre Singapore, Singapore (Singapore); Harianto, F [Institute of Technology Bandung (Indonesia)

    2014-06-01

    Purpose: To determine and compare the correction factors obtained for TLDs in 2 × 2cm{sup 2} small field in lung heterogenous phantom using Acuros XB (AXB) and EGSnrc. Methods: This study will simulate the correction factors due to the perturbation of TLD-100 chips (Harshaw/Thermoscientific, 3 × 3 × 0.9mm{sup 3}, 2.64g/cm{sup 3}) in small field lung medium for Stereotactic Body Radiation Therapy (SBRT). A physical lung phantom was simulated by a 14cm thick composite cork phantom (0.27g/cm{sup 3}, HU:-743 ± 11) sandwiched between 4cm thick Plastic Water (CIRS,Norfolk). Composite cork has been shown to be a good lung substitute material for dosimetric studies. 6MV photon beam from Varian Clinac iX (Varian Medical Systems, Palo Alto, CA) with field size 2 × 2cm{sup 2} was simulated. Depth dose profiles were obtained from the Eclipse treatment planning system Acuros XB (AXB) and independently from DOSxyznrc, EGSnrc. Correction factors was calculated by the ratio of unperturbed to perturbed dose. Since AXB has limitations in simulating actual material compositions, EGSnrc will also simulate the AXB-based material composition for comparison to the actual lung phantom. Results: TLD-100, with its finite size and relatively high density, causes significant perturbation in 2 × 2cm{sup 2} small field in a low lung density phantom. Correction factors calculated by both EGSnrc and AXB was found to be as low as 0.9. It is expected that the correction factor obtained by EGSnrc wlll be more accurate as it is able to simulate the actual phantom material compositions. AXB have a limited material library, therefore it only approximates the composition of TLD, Composite cork and Plastic water, contributing to uncertainties in TLD correction factors. Conclusion: It is expected that the correction factors obtained by EGSnrc will be more accurate. Studies will be done to investigate the correction factors for higher energies where perturbation may be more pronounced.

  20. Tunable deep ultraviolet single-longitudinal-mode laser generated with Ba(1-x)B(2-y-z)O4Si(x)Al(y)Ga(z) crystal.

    Science.gov (United States)

    Wang, Rui; Teng, Hao; Wang, Nan; Han, Hainian; Wang, Zhaohua; Wei, Zhiyi; Hong, Maochun; Lin, Wenxiong

    2014-04-01

    We report a new nonlinear crystal, Ba(1-x)B(2-y-z)O4Si(x)Al(y)Ga(z), and employ it to a compact 1 kHz single-longitudinal-mode Ti:Sapphire master oscillator power amplifier system for fourth harmonic generation. A maximum output power of 130 mW is obtained in the tunable range of 195-205 nm with linewidth of less than 0.1 pm.

  1. Transport and magnetic properties of A3+1-xB2+xMnO3 (A = La, Y or Nd, B = Ca, Sr or Ba) magnetic perovskites

    Science.gov (United States)

    Ranno, L.; Viret, M.; Valentin, F.; McCauley, J.; Coey, J. M. D.

    1996-05-01

    A3+xB2+1-xMnO3 perovskites have striking magneto-resistance properties showing effects close to -100% in fields of a few tesla in some cases. When x = 0.3, magnetic and transport properties are qualitatively similar with a resistivity peak below Tc, but there are enormous quantitative differences depending on the A and B cations present.

  2. Effect of Pr Content on Magnetic Properties of Prx(FeCoZr)94-xB6 Bonded Magnets%Pr含量对快淬Prx(FeCoZr)94-xB6粘结磁体磁性能的影响

    Institute of Scientific and Technical Information of China (English)

    查五生; 刘颖; 刘锦云; 王克强; 高升吉; 涂铭旌

    2004-01-01

    研究了Pr含量对快淬Prx(FeCoZr)94-xB6(x=12.5,12,10.5,9.0)系列粘结磁体磁性能的影响.采用部分过快淬加晶化退火工艺,获得由非晶和微晶组成的条带,晶化处理后制备出最佳磁性能的磁体.随Pr含量的减少,磁体的内禀矫顽力Hci下降而剩磁Br增加,Pr含量低于10%,Br增加缓慢,Hci和(BH)m迅速下降.所以,10%是磁性能发生大的转变的临界Pr含量值,验证了作者提出的完全耦合软磁相体积分数模型.

  3. Competing anisotropies on 3d sub-lattice of YNi{sub 4–x}Co{sub x}B compounds

    Energy Technology Data Exchange (ETDEWEB)

    Caraballo Vivas, R. J.; Rocco, D. L.; Reis, M. S. [Instituto de Física, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, 24210-346 Niterói, RJ (Brazil); Costa Soares, T. [Instituto de Física, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, 24210-346 Niterói, RJ (Brazil); IF Sudeste MG Campus de Juiz de Fora-Núcleo de Física, 36080-001 Juiz de Fora, MG (Brazil); Caldeira, L. [IF Sudeste MG Campus de Juiz de Fora-Núcleo de Física, 36080-001 Juiz de Fora, MG (Brazil); Coelho, A. A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas-Unicamp, Caixa postal 6165, 13083-859 Campinas, SP (Brazil)

    2014-08-14

    The magnetic anisotropy of 3d sub-lattices has an important rule on the overall magnetic properties of hard magnets. Intermetallics alloys with boron (R-Co/Ni-B, for instance) belong to those hard magnets family and are useful objects to help to understand the magnetic behavior of 3d sub-lattice, specially when the rare earth ions R do not have magnetic nature, like YCo{sub 4}B ferromagnetic material. Interestingly, YNi{sub 4}B is a paramagnetic material and Ni ions do not contribute to the magnetic anisotropy. We focused therefore our attention to YNi{sub 4–x}Co{sub x}B series, with x = 0, 1, 2, 3, and 4. The magnetic anisotropy of these compounds is deeper described using statistical and preferential models of Co occupation among the possible Wyckoff positions into the CeCo{sub 4}B type hexagonal structure. We found that the preferential model is the most suitable to explain the magnetization experimental data.

  4. Dependence of Magnetic Properties of Rapidly Quenching (Nd,Pr)x(FeCoZr)94-xB6 Bonded Magnets on Rare Earths Content

    Institute of Scientific and Technical Information of China (English)

    查五生; 刘颖; 高升吉; 连利仙; 涂铭旌

    2004-01-01

    By using sub-overquenching and annealing method which has a wide processing window, (Nd, Pr)x(FeCoZr)94-xB6 (x=12, 10.5, 10, 9) bonded magnets were prepared and the effect of rare earths content on magnetic properties was investigated. Being spun at sub-overquenching speed the as-spun ribbons consist of amorphous phases mixed with fine crystallites. After crystallization under optimum annealing conditions and bonded with 3.25% (mass fraction) epoxy, the magnets obtained the optimum magnetic properties. The rare earths content directly determines the magnetic properties. With the reduction of rare earths content, Br increases but Hci and (BH)max decrease. x=10 is the critical value for the magnetic properties change. Below this value, Br increases slowly meanwhile Hci and (BH)max decrease strongly because alloy contains extra fractions of soft magnetic phase which are not coupled with the hard magnetic phase. This experimental result is consistent with the calculated results using the model of volume fraction of soft magnetic phase coupled completely suggested.

  5. Swift reveals a ~5.7 day super-orbital period in the M31 globular cluster X-ray binary XB158

    CERN Document Server

    Barnard, R; Murrray, S S

    2015-01-01

    The M31 globular cluster X-ray binary XB158 (a.k.a. Bo 158) exhibits intensity dips on a 2.78 hr period in some observations, but not others. The short period suggests a low mass ratio, and an asymmetric, precessing disk due to additional tidal torques from the donor star since the disk crosses the 3:1 resonance. Previous theoretical 3D smoothed particle hydrodynamical modeling suggested a super-orbital disk precession period 29$\\pm$1 times the orbital period, i.e. $\\sim$81$\\pm$3 hr. We conducted a Swift monitoring campaign of 30 observations over ~1 month in order to search for evidence of such a super-orbital period. Fitting the 0.3--10 keV Swift XRT luminosity lightcurve with a sinusoid yielded a period of 5.65+/-0.05 days, and a >5$\\sigma$ improvement in $\\chi^2$ over the best fit constant intensity model. A Lomb-Scargle periodogram revealed that periods 5.4--5.8 days were detected at a >3$\\sigma$ level, with a peak at 5.6 days. We consider this strong evidence for a 5.65 day super-orbital period, ~70\\% l...

  6. Variations in the dip properties of the low-mass X-ray binary XB 1254-69 observed with XMM-Newton and INTEGRAL

    CERN Document Server

    Trigo, M Diaz; Boirin, L; Motch, C; Talavera, A; Balman, S

    2008-01-01

    We have analysed data from five XMM-Newton observations of XB 1254-69, one of them simultaneous with INTEGRAL, to investigate the mechanism responsible for the highly variable dips durations and depths seen from this low-mass X-ray binary. Deep dips were present during two observations, shallow dips during one and no dips were detected during the remaining two observations. At high (1-4 s) time resolution ``shallow dips'' are seen to include a few, very rapid, deep dips whilst the ``deep'' dips consist of many similar very rapid, deep, fluctuations. The folded V-band Optical Monitor light curves obtained when the source was undergoing deep, shallow and no detectable dipping exhibit sinusoid-like variations with different amplitudes and phases. We fit EPIC spectra obtained from "persistent" or dip-free intervals with a model consisting of disc-blackbody and thermal comptonisation components together with Gaussian emission features at 1 and 6.6 keV modified by absorption due to cold and photo-ionised material. ...

  7. Search for the Xb and other hidden-beauty states in the π+π−ϒ(1S channel at ATLAS

    Directory of Open Access Journals (Sweden)

    G. Aad

    2015-01-01

    Full Text Available This Letter presents a search for a hidden-beauty counterpart of the X(3872 in the mass ranges of 10.05–10.31 GeV and 10.40–11.00 GeV, in the channel Xb→π+π−ϒ(1S(→μ+μ−, using 16.2 fb−1 of s=8 TeV pp collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the Xb cross section and branching fraction, relative to those of the ϒ(2S, at the 95% confidence level using the CLS approach. These limits range from 0.8% to 4.0%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the ϒ(13DJ, ϒ(10860, and ϒ(11020 states also reveal no significant signals.

  8. Equivalent Longitudinal Area Distributions of the B-58 and XB-70-1 Airplanes for Use in Wave Drag and Sonic Boom Calculations

    Science.gov (United States)

    Tinetti, Ana F.; Maglieri, Domenic J.; Driver, Cornelius; Bobbitt, Percy J.

    2011-01-01

    A detailed geometric description, in wave drag format, has been developed for the Convair B-58 and North American XB-70-1 delta wing airplanes. These descriptions have been placed on electronic files, the contents of which are described in this paper They are intended for use in wave drag and sonic boom calculations. Included in the electronic file and in the present paper are photographs and 3-view drawings of the two airplanes, tabulated geometric descriptions of each vehicle and its components, and comparisons of the electronic file outputs with existing data. The comparisons include a pictorial of the two airplanes based on the present geometric descriptions, and cross-sectional area distributions for both the normal Mach cuts and oblique Mach cuts above and below the vehicles. Good correlation exists between the area distributions generated in the late 1950s and 1960s and the present files. The availability of these electronic files facilitates further validation of sonic boom prediction codes through the use of two existing data bases on these airplanes, which were acquired in the 1960s and have not been fully exploited.

  9. Quantification of dose differences between two versions of Acuros XB algorithm compared to Monte Carlo simulations--the effect on clinical patient treatment planning.

    Science.gov (United States)

    Ojala, Jarkko Juhani; Kapanen, Mika

    2015-11-08

    A commercialized implementation of linear Boltzmann transport equation solver, the Acuros XB algorithm (AXB), represents a class of most advanced type 'c' photon radiotherapy dose calculation algorithms. The purpose of the study was to quantify the effects of the modifications implemented in the more recent version 11 of the AXB (AXB11) compared to the first commercial implementation, version 10 of the AXB (AXB10), in various anatomical regions in clinical treatment planning. Both versions of the AXB were part of Varian's Eclipse clinical treatment planning system and treatment plans for 10 patients were created using intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT). The plans were first created with the AXB10 and then recalculated with the AXB11 and full Monte Carlo (MC) simulations. Considering the full MC simulations as reference, a DVH analysis for gross tumor and planning target volumes (GTV and PTV) and organs at risk was performed, and also 3D gamma agreement index (GAI) values within a 15% isodose region and for the PTV were determined. Although differences up to 12% in DVH analysis were seen between the MC simulations and the AXB, based on the results of this study no general conclusion can be drawn that the modifications made in the AXB11 compared to the AXB10 would imply that the dose calculation accuracy of the AXB10 would be inferior to the AXB11 in the clinical patient treatment planning. The only clear improvement with the AXB11 over the AXB10 is the dose calculation accuracy in air cavities. In general, no large deviations are present in the DVH analysis results between the two versions of the algorithm, and the results of 3D gamma analysis do not favor one or the other. Thus it may be concluded that the results of the comprehensive studies assessing the accuracy of the AXB10 may be extended to the AXB11.

  10. Dose-to-medium vs. dose-to-water: Dosimetric evaluation of dose reporting modes in Acuros XB for prostate, lung and breast cancer

    Directory of Open Access Journals (Sweden)

    Suresh Rana

    2014-12-01

    Full Text Available Purpose: Acuros XB (AXB dose calculation algorithm is available for external beam photon dose calculations in Eclipse treatment planning system (TPS. The AXB can report the absorbed dose in two modes: dose-to-water (Dw and dose-to-medium (Dm. The main purpose of this study was to compare the dosimetric results of the AXB_Dm with that of AXB_Dw on real patient treatment plans. Methods: Four groups of patients (prostate cancer, stereotactic body radiation therapy (SBRT lung cancer, left breast cancer, and right breast cancer were selected for this study, and each group consisted of 5 cases. The treatment plans of all cases were generated in the Eclipse TPS. For each case, treatment plans were computed using AXB_Dw and AXB_Dm for identical beam arrangements. Dosimetric evaluation was done by comparing various dosimetric parameters in the AXB_Dw plans with that of AXB_Dm plans for the corresponding patient case. Results: For the prostate cancer, the mean planning target volume (PTV dose in the AXB_Dw plans was higher by up to 1.0%, but the mean PTV dose was within ±0.3% for the SBRT lung cancer. The analysis of organs at risk (OAR results in the prostate cancer showed that AXB_Dw plans consistently produced higher values for the bladder and femoral heads but not for the rectum. In the case of SBRT lung cancer, a clear trend was seen for the heart mean dose and spinal cord maximum dose, with AXB_Dw plans producing higher values than the AXB_Dm plans. However, the difference in the lung doses between the AXB_Dm and AXB_Dw plans did not always produce a clear trend, with difference ranged from -1.4% to 2.9%. For both the left and right breast cancer, the AXB_Dm plans produced higher maximum dose to the PTV for all cases. The evaluation of the maximum dose to the skin showed higher values in the AXB_Dm plans for all 5 left breast cancer cases, whereas only 2 cases had higher maximum dose to the skin in the AXB_Dm plans for the right breast cancer

  11. Wind-tunnel/flight correlation study of aerodynamic characteristics of a large flexible supersonic cruise airplane (XB-70-1). 3: A comparison between characteristics predicted from wind-tunnel measurements and those measured in flight

    Science.gov (United States)

    Arnaiz, H. H.; Peterson, J. B., Jr.; Daugherty, J. C.

    1980-01-01

    A program was undertaken by NASA to evaluate the accuracy of a method for predicting the aerodynamic characteristics of large supersonic cruise airplanes. This program compared predicted and flight-measured lift, drag, angle of attack, and control surface deflection for the XB-70-1 airplane for 14 flight conditions with a Mach number range from 0.76 to 2.56. The predictions were derived from the wind-tunnel test data of a 0.03-scale model of the XB-70-1 airplane fabricated to represent the aeroelastically deformed shape at a 2.5 Mach number cruise condition. Corrections for shape variations at the other Mach numbers were included in the prediction. For most cases, differences between predicted and measured values were within the accuracy of the comparison. However, there were significant differences at transonic Mach numbers. At a Mach number of 1.06 differences were as large as 27 percent in the drag coefficients and 20 deg in the elevator deflections. A brief analysis indicated that a significant part of the difference between drag coefficients was due to the incorrect prediction of the control surface deflection required to trim the airplane.

  12. Complex phase dynamics in coupled bursters

    DEFF Research Database (Denmark)

    Postnov, D.E.; Sosnovtseva, Olga; Malova, S.Y.;

    2003-01-01

    The phenomenon of phase multistability in the synchronization of two coupled oscillatory systems typically arises when the systems individually display complex wave forms associated, for instance, with the presence of subharmonic components. Alternatively, phase multistability can be caused...

  13. Likelihood methods and classical burster repetition

    CERN Document Server

    Graziani, C; Graziani, Carlo; Lamb, Donald Q

    1995-01-01

    We develop a likelihood methodology which can be used to search for evidence of burst repetition in the BATSE catalog, and to study the properties of the repetition signal. We use a simplified model of burst repetition in which a number N_{\\rm r} of sources which repeat a fixed number of times N_{\\rm rep} are superposed upon a number N_{\\rm nr} of non-repeating sources. The instrument exposure is explicitly taken into account. By computing the likelihood for the data, we construct a probability distribution in parameter space that may be used to infer the probability that a repetition signal is present, and to estimate the values of the repetition parameters. The likelihood function contains contributions from all the bursts, irrespective of the size of their positional errors --- the more uncertain a burst's position is, the less constraining is its contribution. Thus this approach makes maximal use of the data, and avoids the ambiguities of sample selection associated with data cuts on error circle size. We...

  14. Complex phase dynamics in coupled bursters

    DEFF Research Database (Denmark)

    Postnov, D E; Sosnovtseva, Olga; Malova, S Y

    2003-01-01

    The phenomenon of phase multistability in the synchronization of two coupled oscillatory systems typically arises when the systems individually display complex wave forms associated, for instance, with the presence of subharmonic components. Alternatively, phase multistability can be caused...... the number of spikes per train and the proximity of a neighboring equilibrium point can influence the formation of coexisting regimes....

  15. Influence of Co substitution on magnetoelastic properties of Er{sub 2}Fe{sub 14-x}Co{sub x}B (x = 1, 3 and 5) intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Khoshnoud, D. Sanavi [Faculty of Science, Department of Physics, Ferdowsi University of Mashhad, Mashhad, Khorasan Razavi (Iran, Islamic Republic of); Tajabor, N. [Faculty of Science, Department of Physics, Ferdowsi University of Mashhad, Mashhad, Khorasan Razavi (Iran, Islamic Republic of)], E-mail: tajabor@ferdowsi.um.ac.ir; Fruchart, D.; Gignoux, D.; Miraglia, S. [Institut. Neel, Departement MCMF, Groupe IICF, BP 166, 38042 Grenoble Cedex 9 (France); Pourarian, F. [Department of Material Science and Engineering, Carengie Mellon University, Pittsburgh, PA 15219 (United States)

    2009-07-08

    The magnetostriction and thermal expansion of Er{sub 2}Fe{sub 14-x}Co{sub x}B (x = 1, 3 and 5) intermetallic compounds were measured, using the strain gauge method in the temperature range 75-450 K under applied magnetic fields up to 1.5 T. For all samples the longitudinal magnetostriction ({lambda}{sub l}) undergoes an anomaly around the spin reorientation temperature (T{sub SR}). It is also observed that {lambda}{sub l} decreases with increasing the Co content. All compounds show saturation type behaviour in their anisotropic magnetostriction curves at different temperatures and applied fields. The saturation behaviour of the compound with x = 3 occurs at higher temperatures than with x = 1 and 5. The volume magnetostriction strongly increases below {mu}{sub 0}H = 0.3 T, then monotonically rises with applied field up to the spin reorientation temperature. An invar type behaviour is observed above 200 K in the compound with x = 1. The results are discussed based on the temperature dependence of magnetocrystalline anisotropy of compounds below and above their T{sub SR}.

  16. Observation of $e^+e^- \\to \\pi^+ \\pi^- \\pi^0 \\chi_{bJ}$ and search for $X_b \\to \\omega \\Upsilon(1S)$ at $\\sqrt{s}\\sim 10.867$ GeV

    CERN Document Server

    He, X H; Yuan, C Z; Ban, Y; Abdesselam, A; Adachi, I; Aihara, H; Asner, D M; Aulchenko, V; Aushev, T; Ayad, R; Bahinipati, S; Bakich, A M; Bansal, V; Bhuyan, B; Bondar, A; Bonvicini, G; Bozek, A; Browder, T E; Červenkov, D; Chang, P; Chekelian, V; Chen, A; Cheon, B G; Chilikin, K; Chistov, R; Cho, K; Chobanova, V; Choi, S -K; Choi, Y; Cinabro, D; Dalseno, J; Danilov, M; Doležal, Z; Drásal, Z; Drutskoy, A; Eidelman, S; Farhat, H; Fast, J E; Ferber, T; Gaur, V; Gabyshev, N; Ganguly, S; Garmash, A; Gillard, R; Glattauer, R; Goh, Y M; Grzymkowska, O; Haba, J; Hayasaka, K; Hayashii, H; Hou, W -S; Iijima, T; Ishikawa, A; Itoh, R; Iwasaki, Y; Jaegle, I; Joo, K K; Julius, T; Kato, E; Kawasaki, T; Kim, D Y; Kim, M J; Kim, Y J; Kinoshita, K; Ko, B R; Kodyš, P; Korpar, S; Križan, P; Krokovny, P; Kumita, T; Kwon, Y -J; Li, Y; Libby, J; Liventsev, D; Matvienko, D; Miyata, H; Mizuk, R; Mohanty, G B; Moll, A; Mussa, R; Nakano, E; Nakao, M; Nanut, T; Natkaniec, Z; Nedelkovska, E; Nisar, N K; Nishida, S; Ogawa, S; Okuno, S; Pakhlov, P; Pakhlova, G; Park, H; Pedlar, T K; Pestotnik, R; Petrič, M; Piilonen, L E; Ritter, M; Rostomyan, A; Sakai, Y; Sandilya, S; Santelj, L; Sanuki, T; Sato, Y; Savinov, V; Schneider, O; Schnell, G; Schwanda, C; Semmler, D; Senyo, K; Sevior, M E; Shebalin, V; Shibata, T -A; Shiu, J -G; Shwartz, B; Sibidanov, A; Simon, F; Sohn, Y -S; Sokolov, A; Solovieva, E; Starič, M; Steder, M; Sumisawa, K; Sumiyoshi, T; Tamponi, U; Tanida, K; Tatishvili, G; Teramoto, Y; Thorne, F; Trabelsi, K; Uchida, M; Uehara, S; Uglov, T; Unno, Y; Uno, S; Urquijo, P; Vahsen, S E; Van Hulse, C; Vanhoefer, P; Varner, G; Vinokurova, A; Vorobyev, V; Wagner, M N; Wang, C H; Wang, M -Z; Wang, P; Wang, X L; Watanabe, M; Watanabe, Y; Wehle, S; Williams, K M; Won, E; Yamaoka, J; Yashchenko, S; Yook, Y; Yusa, Y; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A

    2014-01-01

    The $e^+e^- \\to \\pi^+ \\pi^- \\pi^0 \\chi_{bJ}$ ($J=0,~1,~2$) processes are studied using a 118~fb$^{-1}$ data sample collected at a center-of-mass energy of 10.867 GeV, in the $\\Upsilon(10860)$ energy range, with the Belle detector. The $\\pi^+ \\pi^- \\pi^0 \\chi_{b1}$, $\\pi^+\\pi^-\\pi^0\\chi_{b2}$, $\\omega\\chi_{b1}$ signals and the evidence of $\\omega\\chi_{b2}$ are observed for the first time and the cross sections are measured. No significant $\\pi^+\\pi^-\\pi^0\\chi_{b0}$ or $\\omega\\chi_{b0}$ signal is observed and 90\\% confidence level upper limits on the cross sections for these two processes are obtained. In the $\\pi^+\\pi^-\\pi^0$ invariant mass spectrum, significant non-$\\omega$ signals are also observed. We search for the $X(3872)$-like state with a hidden $b\\bar{b}$ component (named $X_b$) decaying into $\\omega \\Upsilon(1S)$; no significant signal is observed with a mass between $10.55$ and $10.65$ GeV/$c^2$.

  17. 基于二阶系统解耦对非奇异解的研究%Research on nonsingular solution of AX+XB=0 equation based on quadratic system decoupling

    Institute of Scientific and Technical Information of China (English)

    张善美; 许峰

    2014-01-01

    对求解齐次AX+XB=0方程非奇异解的研究,可以有效解决二阶系统解耦问题。但高阶系统无法通过正常的计算方法找到非奇异解,而且误差很高。针对由二阶系统变形来的AX+XB=0方程,并对其具有的特殊形式进行研究探讨,找到解的构造方法,从而更加准确的找到其非奇异解,将二阶系统进行有效的解耦,数值试验证明了该方法的可行性。%The research of nonsingular solution of the AX+XB=0 equation solution can ef-fectively solve the decoupling problem of second order system .However , high-order system cannot find the singular solution through the calculation method of normal , and the error is very high .In this paper , by the deformation to the equation of second order system with spe-cial form of research , the solution of the method was found , which was more accurate to find the singular solution , and effectively decouple the second -order system.The results of nu-merical experiments showed this constitution method was a feasible one , which supplied a simple approach for nonsingular solution of the Sylvester equation .

  18. Search for pulsations in the LMXB EXO 0748-676

    Institute of Scientific and Technical Information of China (English)

    Chetana Jain; Biswajit Paul

    2011-01-01

    We present here results from our search for X-ray pulsations of the neutron star in the low mass X-ray binary EXO 0748-676 at a frequency near the burstoscillation frequency of 44.7 Hz.Using the observations made with the Proportional Counter Array onboard the Rossi X-ray Timing Explorer, we did not find any pulsations in the frequency band of 44.4 Hz to 45.0 Hz and obtained a 3σ upper limit of 0.47% on the pulsed fraction for any possible underlying pulsation in this frequency band.We also discuss the importance of EXO 0748-676 as a promising source for the detection of Gravitational Waves.

  19. Effect of Small Addition of Cobalt on Magnetic Properties and Internal Stresses Sources in the Form of Free Volumes and Pseudo-Dislocation Dipoles in Fe78CoXSi11-XB11 (x = 0 Or 2 Alloys / Wpływ Nieznacznego Dodatku Kobaltu Na Właściwości Magnetyczne Oraz Źródła Naprężeń Wewnętrznych W Postaci Wolnych Objętości Oraz Pseudodyslokacyjnych Dipoli W Stopach Fe78CoXSi11-XB11 (x = 0 Or 2

    Directory of Open Access Journals (Sweden)

    Szota M.

    2015-12-01

    Full Text Available Amorphous materials in the form of tapes, despite being discovered more than half a century ago, are still the object of interest for materials engineers and electro-technical industry. They possess a great application potential, and are constantly studied for new variations. Due to the different structure from the commonly manufactured textured FeSi sheets, FeCoB based amorphous alloys demonstrate very good, so called soft magnetic properties. This paper presents the results of studying the structure and magnetic properties of tapes of Fe78CoxSi11-xB11 (X = 0 or 2 alloys of amorphous structure. In addition, the effect of Co alloy addition on the type of structural defects in the area of ferromagnetic saturation approach was examined. It was found that a small addition of Co affects the increase of saturation magnetization value, as well as the distribution of magnetization vectors within the stresses sources in form of structure defects.

  20. $\\gamma$-Ray Burster Counterparts HST Blue and Ultraviolet Data

    CERN Document Server

    Schaefer, B E; Hurley, K; Laros, J G; Schaefer, Bradley E.; Cline, Thomas; Hurley, Kevin; Laros, John

    1997-01-01

    The surest solution of the Gamma Ray Burst (GRB) mystery is to find an unambiguous low-energy quiescent counterpart. However, to date no reasonable candidates have been identified in the x-ray, optical, infrared, or radio ranges. The Hubble Space Telescope (HST) has now allowed for the first deep ultraviolet searches for quiescent counterparts. This paper reports on multiepoch ultraviolet searches of five GRB positions with HST. We found no sources with significant ultraviolet excesses, variability, parallax, or proper motion in any of the burst error regions. In particular, we see no sources similar to that proposed as a counterpart to the GRB970228. While this negative result is disappointing, it still has good utility for its strict limits on the no-host-galaxy problem in cosmological models of GRBs. For most cosmological models (with peak luminosity 6X10^50 erg/s), the absolute B magnitude of any possible host galaxy must be fainter than -15.5 to -17.4. These smallest boxes for some of the brightest burst...

  1. An Improved Study of Electronic Band Structure and Optical Parameters of X-Phosphides (X--B, AL, Ga, In) by Modified Becke-Johnson Potential%An Improved Study of Electronic Band Structure and Optical Parameters of X-Phosphides (X--B, AL, Ga, In) by Modified Becke-Johnson Potential

    Institute of Scientific and Technical Information of China (English)

    Masood Yousaf; M.A. Saeed; R. Ahmed; M.M. Alsardia; Ahmad Radzi Mat Isa; A. Shaari

    2012-01-01

    We report the electronic band structure and optical parameters of X-Phosphides (X=B, AI, Ga, In) by first-principles technique based on a new approximation known as modified Becke-Johnson (roB J). This potential is considered more accurate in elaborating excited states properties of insulators and semiconductors as compared to LDA and GGA. The present calculated band gaps values of BP, AlP, GaP, and InP are 1.867 eV, 2.268 eV, 2.090 eV, and 1.377 eV respectively, which are in close agreement to the experimental results. The band gap values trend in this study is as: E9 (mBJ-GGA/LDA) 〉 E9 (GGA) 〉 Eg (LDA). Optical parametric quantities (dielectric constant, refractive index, reflectivity and optical conductivity) which based on the band structure are aiso presented and discussed. BP, AlP, GaP, and InP have strong absorption in between the energy range 4-9 eV, 4-7 ev, 3-7 eV, and 2-7 eV respectively. Static dielectric constant, static refractive index and coefficient of reflectivity at zero frequency, within mBJ-GGA, are also calculated. BP, AIP, GaP, and InP show significant optical conductivity in the range 5.2-10 eV, 4.3-8 eV, 3.5- 7.2 eV, and 3.2-8 eV respectively. The present study endorses that the said compounds can be used in opto-electronic applications, for different energy ranges.

  2. 77 FR 70147 - Fish and Wildlife Service 0648-XB088

    Science.gov (United States)

    2012-11-23

    ... Madera, Bear, Dennis Martin, Sausal, and Alambique creeks, and portions of San Francisquito, Los Trancos, Corte Madera, and Bear creeks flow through Stanford lands. The Matadero/Deer Creek watershed is...

  3. The Unusual Long Term Variability of LMXB 4U 1705-440---Fingerprints of Chaotic Evolution?

    Science.gov (United States)

    Boyd, Patricia T.; Phillipson, Rebecca; Smale, Alan P.

    2016-04-01

    The bursting Atoll source 4U 1705-44, exhibits high amplitude, long-term aperiodic variability on characteristic timescales of several hundred days. The brightness of the system makes it continuously observable by a variety of all-sky monitors. We combine data from te All-Sky Monitor (ASM) aboard the Rossi X-ray Timing Explorer (RXTE) and MAXI, the Japanese X-ray All-Sky Monitor aboard the International Space Station, resulting in a continuous, uninterrupted, evenly spaced time series containing over fifty cycles at the timescale of interest. We construct a two-dimensional phase space from the flux versus its first derivative, and find a strong resemblence to the canonical double-welled nonlinear Duffing osciallator. We uncover several low-order unstable periodic orbits embedded in the light curve of 4U 1705-44, which imply that the "period-1" orbit lasts ~120 days. We find clear signatures of period-1, period-2 and period-3 orbits and extract these to calculate their topological behavior in phase space. The topoligical relations suggest that the equations describing the long term evolution of 4U 1705-44 are similar to those of the Duffing oscillator. This puts limits on the allowable models describing the longterm variability of 4U 1705-44 and, by extention, to the allowable models describing other systems which show non-periodic superorbital variability.

  4. Optical and infrared polarimetry of the transient LMXB Cen X-4 in quiescence

    CERN Document Server

    Baglio, M C; Campana, S; Covino, S

    2014-01-01

    We present the first optical and infrared polarimetric study of the low mass transient X-ray binary Cen X-4 during its quiescent phase. This work is aimed to search for an intrinsic linear polarisation component in the system emitted radiation that might be due, e.g., to synchrotron emission from a compact jet, or to Thomson scattering with free electrons in an accretion disc. Multiband (BVRI) optical polarimetric observations were obtained during two nights in 2008 at the ESO La Silla 3.6 m telescope (EFOSC2) in polarimetric mode. These observations cover about the 30% of the 15.1 hours orbital period. J-band observations were obtained in 2007 with the NICS (TNG) instrument at La Palma, for a totality of 1 hour observation. We obtained 3-sigma upper limits to the polarisation degree in all the optical bands, with the most constraining one being in the I-band (P<0.5%). No phase-correlated variability has been noticed in all the filters. The J-band observations provided a 6% upper limit on the polarisation ...

  5. Study of the reflection spectrum of the LMXB 4U 1702-429

    CERN Document Server

    Iaria, R; Del Santo, M; Pintore, F; Sanna, A; Papitto, A; Burderi, L; Riggio, A; Gambino, A F; Matranga, M

    2016-01-01

    The source 4U 1702-429 (Ara X-1) is a low-mass X-ray binary system hosting a neutron star. Albeit the source is quite bright ( $\\sim10^{37}$ erg s$^{-1}$) its broadband spectrum has never been studied. Neither dips nor eclipses have been observed in the light curve suggesting that its inclination angle is smaller than 60$^{\\circ}$.We analysed the broadband spectrum of 4U 1702-429 in the 0.3-60 keV energy range, using XMM-Newton and INTEGRAL data, to constrain its Compton reflection component if it is present. After excluding the three time intervals in which three type-I X-ray bursts occurred, we fitted the joint XMM-Newton and INTEGRAL spectra obtained from simultaneous observations. A broad emission line at 6.7 keV and two absorption edges at 0.87 and 8.82 keV were detected. We found that a self-consistent reflection model fits the 0.3-60 keV spectrum well. The broadband continuum is composed of an emission component originating from the inner region of the accretion disc, a Comptonised direct emission comi...

  6. A Survey of Unclassified ROSAT-BSC Sources for qLMXB Candidates

    Science.gov (United States)

    Dufour, Francois; Rutledge, Robert E.

    2014-08-01

    Spectroscopic measurements of the thermal emission of neutron stars in quiescent low-mass X-ray binaries (qLMXBs) are one of only three methods to constrain the equation of state of cold nuclear matter. Up to now, this method has been limited in its application to qLMXBs within globular clusters, due to the high distance uncertainty of qLMXBs in the field. Gaia parallax measurements will soon allow the use of field qLMXBs with sufficiently bright optical counterparts in this key test of physics. We propose to undertake a survey of unclassified ROSAT BSC sources with high apparent X-ray to infrared flux ratios for H(alpha) excess, a tell-tale sign of accretion disks, in order to select qLMXBs candidates for X-ray followup.

  7. Disk emission and absorption lines in LMXB. Note on the physical conditions of an absorbing material

    CERN Document Server

    Rozanska, Agata

    2014-01-01

    We show that the continuum X-ray spectrum of 4U 1630-472 with iron absorption lines can be satisfactorily modeled by the spectrum from an accretion disk atmosphere. We performed full radiative transfer calculations using our code ATM21 to model the emission from an accretion disk surface that is seen at different viewing angles. Computed models are then fitted to the high-resolution X-ray spectra of 4U 1630-472 obtained by {\\it Suzaku} satellite. Absorption lines of highly ionized iron originating in a hot accretion-disk atmospheres are important part of the observed line profile, and can be an alternative or complementary explanation to the wind model usually favored for this type of sources. Next, assuming that absorption lines originate from the wind illuminated by X-ray central source in LMXBs, we can put constrains on the wind location only if we know the volume density number of the absorbing material. There are a few derivations of the distance to the wind in X-ray binaries. We show here, that the dens...

  8. The puzzling orbital period evolution of the LMXB AX J1745.6-2901

    Science.gov (United States)

    Ponti, G.; De, K.; Muñoz-Darias, T.; Stella, L.; Nandra, K.

    2016-09-01

    The orbital period evolution of X-ray binaries provides fundamental clues to understanding mechanisms of angular momentum transfer and loss in these systems. We present an X-ray eclipse timing analysis of the transient low mass X-ray binary AX J1745.6-2901. This system shows full eclipses and thus is one of the few objects of this class for which accurate orbital evolution studies can be carried out. We report on XMM-Newton and ASCA observations covering 30 complete X-ray eclipses spanning an interval of more than 20 years. We improve the determination of the orbital period to a relative precision of 2 × 10-8, two orders of magnitudes better than previous measurements. We determine, for the first time, a highly significant rate of decrease of the orbital period dot{P}_{orb}=-4.03± 0.32× 10^{-11} s/s. This is at least one order of magnitude larger than expected from conservative mass transfer and angular momentum losses due to gravitational waves and magnetic braking, and might result from either non-conservative mass transfer or magnetic activity changing the quadrupole moment of the companion star. Imprinted on the long term evolution of the orbit, we observe highly significant eclipse leads-delays of ˜10 - 30 s, characterised by a clear state dependence in which, on average, eclipses occur earlier during the hard state.

  9. LMXB and IMXB Evolution: I. The Binary Radio Pulsar PSR J1614-2230

    CERN Document Server

    Lin, Jinrong; Podsiadlowski, Ph; Nelson, L; Paxton, B; Todorov, P

    2010-01-01

    We have computed an extensive grid of binary evolution tracks to represent low- and intermediate mass X-ray binaries (LMXBs and IMXBs). The grid includes 42,000 models which covers 60 initial donor masses over the range of 1-4 solar masses and, for each of these, 700 initial orbital periods over the range of 10-250 hours. These results can be applied to understanding LMXBs and IMXBs: those that evolve analogously to CVs; those that form ultracompact binaries with orbital periods in the range of 6-50 minutes; and those that lead to wide orbits with giant donors. We also investigate the relic binary recycled radio pulsars into which these systems evolve. To evolve the donor stars in this study, we utilized a newly developed stellar evolution code called "MESA" that was designed, among other things, to be able to handle very low-mass and degenerate donors. This first application of the results is aimed at an understanding of the newly discovered pulsar PSR J1614-2230 which has a 1.97 solar masses neutron star, o...

  10. The puzzling orbital period evolution of the LMXB AX J1745.6-2901

    Science.gov (United States)

    Ponti, G.; De, K.; Muñoz-Darias, T.; Stella, L.; Nandra, K.

    2017-01-01

    The orbital period evolution of X-ray binaries provides fundamental clues to understanding mechanisms of angular momentum transfer and loss in these systems. We present an X-ray eclipse timing analysis of the transient low-mass X-ray binary AX J1745.6-2901. This system shows full eclipses and thus is one of the few objects of this class for which accurate orbital evolution studies can be carried out. We report on XMM-Newton and ASCA observations covering 30 complete X-ray eclipses spanning an interval of more than 20 yr. We improve the determination of the orbital period to a relative precision of 2 × 10-8, two orders of magnitudes better than previous measurements. We determine, for the first time, a highly significant rate of decrease of the orbital period dot{P}_{orb}=-4.03± 0.32{×} 10^{-11} s s-1. This is at least one order of magnitude larger than expected from conservative mass transfer and angular momentum losses due to gravitational waves and magnetic braking, and might result from either non-conservative mass transfer or magnetic activity changing the quadrupole moment of the companion star. Imprinted on the long-term evolution of the orbit, we observe highly significant eclipse leads-delays of ˜10-30 s, characterized by a clear state dependence in which, on average, eclipses occur earlier during the hard state.

  11. LMXB X-ray Transients: Revealing Basic Accretion Parameters in Non-stationary Regimes

    Science.gov (United States)

    Yu, Wenfei; Yan, Zhen; Zhang, Hui; Zhang, Wenda

    2014-08-01

    X-ray observations of low mass X-ray binaries(LMXBs), especially those black hole transient systems, have been very important in shaping up our understanding of black hole accretion and testing accretion theory in a broad range of accretion regimes. We show strong evidence for non-stationary accretion regimes in the X-ray observations of spectral states and multi-wavelength observations of disk-jet coupling in more than 100 outbursts of 36 black hole and neutron star transients in the past decade or so. The occurrence of spectral state transitions and the peak episodic jet power during the rising phase of transient outbursts are found correlated with rate-of-increase of the X-ray luminosity, indicating the rate-of-change of the mass accretion rate, in addition to the mass accretion rate, must be considered when interpreting observations of spectral state transitions and disk-jet coupling in these X-ray transients. This is supported by observations since the increase of the mass accretion rate due to its rate-of-change on the observational time scale of interest is significant during outbursts.

  12. New insights into the quasi-periodic X-ray burster GS 0836-429

    Science.gov (United States)

    Aranzana, E.; Sánchez-Fernández, C.; Kuulkers, E.

    2016-02-01

    GS 0836-429 is a neutron star X-ray transient that displays Type-I X-ray bursts. In 2003 and 2004 it experienced two outbursts in X-rays. We present here an analysis of the system's bursting properties during these outbursts. We studied the evolution of the 2003-2004 outbursts in soft X-rays using RXTE (2.5-12 keV; ASM) and in hard X-rays with INTEGRAL (17-80 keV, IBIS/ISGRI). Using data from the JEM-X monitor onboard INTEGRAL, we studied the bursting properties of the source. We detected 61 Type-I X-ray bursts during the 2004 outburst and confirm that the source displayed a quasi-periodic burst recurrence time of about 2.3 h. We improve the characterisation of the fuel composition, as well as the description of the typical burst durations and fluences. We estimate the average value of α to be 49 ± 3, which describes the ratio of the gravitational energy released between bursts to the nuclear energy released in an X-ray burst. Both this value and the observed burst profiles indicate a regime of a mixed He/H runaway triggered by unstable helium ignition. In addition, we report the detection of four series of double bursts, with burst recurrence times of ≤20 min. The secondary bursts are always shorter and less energetic than the primary and typical bursts from the source. The measured recurrence time in double bursts is too short to allow the accretion of enough fresh material, which is needed to trigger a Type-I X-ray burst. This suggests the presence of leftover, unburned material from the preceding burst, which gets ignited on a time scale of minutes. The energies and time scales of the secondary bursts suggest a lower fraction of hydrogen compared to that estimated for the primary bursts. The persistent emission was roughly constant during the period when the Type I X-ray bursts were detected. We derive an average accretion rate during our observations of ṁ ~ 8% ṁEdd. The spectrum of the persistent emission during these observations can be fit with a non-thermal component, indicative for the source to be in a hard state when the INTEGRAL observations were performed.

  13. Swift follow-up of the newly discovered burster millisecond pulsar IGR J17511-3057

    DEFF Research Database (Denmark)

    Bozzo, E.; Ferrigno, C.; Kuulkers, E.;

    2009-01-01

    2.5 ks were accumulated in window timing (WT) mode. A thermonuclear type-I X-ray burst was discovered in the WT light curve of the source at 2009-09-14 00:51:37 UTC with an exponential decay time of ~12.5 s. This burst is most likely a He burst. The WT 0.5-10 keV X-ray spectrum is well described.......2+/-0.2. The absorbed 0.5-10 keV X-ray flux is 6.0e-10 ergs/cm^2/s....

  14. INTEGRAL observation of the X-ray burster KS 1741-293

    CERN Document Server

    De Cesare, G; Stratta, G; Santo, M D; Tarana, A; Ubertini, P

    2005-01-01

    KS 1741-293 was firstly detected in 1989 with the X-ray wide field camera TTM (3-10 keV) on board of the Rontgen-Kvant-Mir observatory. During these observations this source exhibited two X-ray bursts allowing to identify it as a neutron star in a Low mass X-ray Binary. During the BeppoSAX/WFC monitoring of the Galactic Centre Region, KS 1741-293 was also reported at a flux level of 6 mCrab in the 2-9 keV and 25 mCrab in the 9-25 keV energy range. Thanks to the deep and regular INTEGRAL observation of the Galactic Centre region, KS 1741-293 has been observed by the X-ray monitor JEM-X and the imager IBIS in a wide energy range, giving for the first time relevant information on its high energy behaviour. Furthermore, two X-ray bursts have been detected by JEM-X. We report on IBIS and JEM-X data analysis in terms of flux monitoring, spectral proprieties and bursts detection. The data reduction has been done with the most recent release of the standard analysis software (OSA 5.0).

  15. INTEGRAL observation of the X-ray burster KS 1741-293

    OpenAIRE

    De Cesare, G.; Bazzano, A.; Stratta, G.; del Santo, M.; Tarana, A.; Ubertini, P.

    2005-01-01

    KS 1741-293 was firstly detected in 1989 with the X-ray wide field camera TTM (3-10 keV) on board of the Rontgen-Kvant-Mir observatory. During these observations this source exhibited two X-ray bursts allowing to identify it as a neutron star in a Low mass X-ray Binary. During the BeppoSAX/WFC monitoring of the Galactic Centre Region, KS 1741-293 was also reported at a flux level of 6 mCrab in the 2-9 keV and 25 mCrab in the 9-25 keV energy range. Thanks to the deep and regular INTEGRAL obser...

  16. RXTE Confirms Persistent Activity of Burster IGR J17473-2721

    Science.gov (United States)

    Markwardt, C. B.; Altamirano, D.; Swank, J. H.; in't Zand, J.

    2008-04-01

    Following reports of bursting activity of IGR J17473-2721 (= XTE J1747-274) by the AGILE team (Del Monte et al., ATEL #1445) and from Swift (Altamirano et al., ATEL #1459), we note that RXTE PCA monitoring scans of the source also reveal persistent activity. Scans on 2008-03-28 at 18:50 UT and 2008-03-31 at 15:10 UT found 2-10 keV fluxes of about 13 and 18 mCrab, respectively. Previous scans are consistent with quiescent level (with 2-sigma upper limits ~6 mCrab).

  17. Radio emission from supernovae and gamma-ray bursters and the need for the SKA

    Science.gov (United States)

    Weiler, Kurt W.; Van Dyk, Schuyler D.; Sramek, Richard A.; Panagia, Nino

    2004-12-01

    Study of radio supernovae (SNe) over the past 25 years includes two dozen detected objects and more than 100 upper limits. From this work it is possible to identify classes of radio properties, demonstrate conformance to and deviations from existing models, estimate the density and structure of the circumstellar material and, by inference, the evolution of the presupernova stellar wind, and reveal the last stages of stellar evolution before explosion. It is also possible to detect ionized hydrogen along the line of sight, to demonstrate binary properties of the stellar system, and to show clumpiness of the circumstellar material. Since 1997 the afterglow of γ-ray bursting sources (GRBs) has occasionally been detected in the radio, as well in other wavelength bands. In particular, the interesting and unusual γ-ray burst GRB 980425, almost certainly related to the radio supernova SN 1998bw, and the more recent SN 2003dh/GRB 030329 are links between the two classes of objects. Analyzing the extensive radio emission data available for SN 1998bw, one can describe its time evolution within the well established framework available for the analysis of radio emission from supernovae. This then allows relatively detailed description of a number of physical properties of the object. The radio emission can best be explained as the interaction of a mildly relativistic ( Γ ˜ 1.6) shock with a dense pre-explosion stellar wind-established circumstellar medium that is highly structured both azimuthally, in clumps or filaments, and radially, with observed density enhancements. From this we can support the conclusion that at least some members of the slow-soft class of GRBs are related to type Ib/c SNe and can be attributed to the explosion of a massive star in a dense, highly structured CSM that was presumably established by the pre-explosion stellar system. However, due to the lack of sensitivity of current radio telescopes, most supernovae cannot be studied if they are more distant than the Virgo Cluster (˜20 Mpc) or, for exceptionally luminous Type IIn supernovae, beyond ˜100 Mpc. While the GRBs are up to 4 orders-of-magnitude more radio luminous, they are also generally much more distant because of their small probability of detection in smaller volumes of space and most are at z ˜ 1. Those which are radio detected rarely exceed peak flux densities of ˜100 - 300 μJy. Such low flux densities mean that detailed study of their radio "light curves" and, derived from those light curves, the energetics and dynamics of the explosions and the properties of their progenitors and the circumburst medium is very difficult and severely limited in scope. The increased capability of the SKA to attack these problems will significantly advance the field.

  18. Intrinsic bursters increase the robustness of rhythm generation in an excitatory network.

    Science.gov (United States)

    Purvis, L K; Smith, J C; Koizumi, H; Butera, R J

    2007-02-01

    The pre-Botzinger complex (pBC) is a vital subcircuit of the respiratory central pattern generator. Although the existence of neurons with pacemaker-like bursting properties in this network is not questioned, their role in network rhythmogenesis is unresolved. Modeling is ideally suited to address this debate because of the ease with which biophysical parameters of individual cells and network architecture can be manipulated. We modeled the parameter variability of experimental data from pBC bursting pacemaker and nonpacemaker neurons using a modified version of our previously developed pBC neuron and network models. To investigate the role of pacemakers in networkwide rhythmogenesis, we simulated networks of these neurons and varied the fraction of the population made up of pacemakers. For each number of pacemaker neurons, we varied the amount of tonic drive to the network and measured the frequency of synchronous networkwide bursting produced. Both excitatory networks with all-to-all coupling and sparsely connected networks were explored for several levels of synaptic coupling strength. Networks containing only nonpacemakers were able to produce networkwide bursting, but with a low probability of bursting and low input and output ranges. Our results indicate that inclusion of pacemakers in an excitatory network increases robustness of the network by more than tripling the input and output ranges compared with networks containing no pacemakers. The largest increase in dynamic range occurs when the number of pacemakers in the network is greater than 20% of the population. Experimental tests of our model predictions are proposed.

  19. Galactic gamma-ray bursters - an alternative source of cosmic rays at all energies

    OpenAIRE

    A. Dar; Plaga, R.

    1999-01-01

    We propose a new hypothesis for the origin of the major part of non-solar hadronic cosmic rays (CRs) at all energies: highly relativistic, narrowly collimated jets from the birth or collapse of neutron stars (NSs) in our Galaxy accelerate ambient disk and halo matter to CR energies and disperse it in hot spots which they form when they stop in the Galactic halo. Such events are seen as cosmological gamma-ray bursts (GRBs) in other galaxies when their beamed radiation happens to point towards ...

  20. Canards in a minimal piecewise-linear square-wave burster

    Science.gov (United States)

    Desroches, M.; Fernández-García, S.; Krupa, M.

    2016-07-01

    We construct a piecewise-linear (PWL) approximation of the Hindmarsh-Rose (HR) neuron model that is minimal, in the sense that the vector field has the least number of linearity zones, in order to reproduce all the dynamics present in the original HR model with classical parameter values. This includes square-wave bursting and also special trajectories called canards, which possess long repelling segments and organise the transitions between stable bursting patterns with n and n + 1 spikes, also referred to as spike-adding canard explosions. We propose a first approximation of the smooth HR model, using a continuous PWL system, and show that its fast subsystem cannot possess a homoclinic bifurcation, which is necessary to obtain proper square-wave bursting. We then relax the assumption of continuity of the vector field across all zones, and we show that we can obtain a homoclinic bifurcation in the fast subsystem. We use the recently developed canard theory for PWL systems in order to reproduce the spike-adding canard explosion feature of the HR model as studied, e.g., in Desroches et al., Chaos 23(4), 046106 (2013).

  1. New insights into the quasi-periodic X-ray burster GS 0836-429

    CERN Document Server

    Aranzana, E; Kuulkers, E

    2015-01-01

    GS 0836-429 is a neutron star X-ray transient that displays Type-I X-ray bursts. In 2003 and 2004 it experienced two outbursts in X-rays. We present here an analysis of the system bursting properties during these outbursts. We studied the evolution of the 2003-2004 outbursts in soft X-rays using RXTE (2.5-12 keV; ASM), and in hard X-rays with INTEGRAL (17-80 keV, IBIS/ISGRI). Using data from the JEM-X monitor onboard INTEGRAL we detected 61 Type-I X-ray bursts, and confirm that the source displayed a quasi-periodic burst recurrence time of about 2.3 hours. We improve the characterization of the fuel composition, as well as the description of the typical burst durations and fluences. We estimate the average value of $\\alpha$ to be $49\\pm\\,3$. This value together with the observed burst profiles indicate a regime of a mixed He/H runaway triggered by unstable helium ignition. In addition, we report the detection of four series of double bursts, with burst recurrence times of $\\leq\\,20$ minutes. The measured recu...

  2. A coupled chemical burster: The chlorine dioxide-iodide reaction in two flow reactors

    Science.gov (United States)

    Dolnik, Milos; Epstein, Irving R.

    1993-01-01

    The dynamical behavior of the chlorine dioxide-iodide reaction has been studied in a system consisting of two continuous flow stirred tank reactors (CSTRs). The reactors are coupled by computer monitoring of the electrochemical potential in each reactor, which is then used to control the input into the other reactor. Two forms of coupling are employed: reciprocally triggered, exponentially decreasing stimulation, and alternating mass exchange. The reaction, which exhibits oscillatory and excitable behavior in a single CSTR, displays neuronlike bursting behavior with both forms of coupling. Reciprocal stimulation yields bursting in both reactors, while with alternating mass exchange, bursting is observed in one reactor and complex oscillation in the other. A simple model of the reaction gives good agreement between the experimental observations and numerical simulations.

  3. Shared inputs and desynchrony in elliptic bursters: from slow passage to discontinuous circle maps

    CERN Document Server

    Lajoie, Guillaume

    2010-01-01

    What input signals will lead to synchrony vs. desynchrony in a group of biological oscillators? This question connects with both classical dynamical sys- tems analyses of entrainment and phase locking and with emerging studies of stimulation patterns for controlling neural network activity. Here, we focus on the response of a population of uncoupled, elliptically bursting neurons to a com- mon pulsatile input. We extend a phase reduction from the literature to capture inputs of varied strength, leading to a circle map with discontinuities of various orders. In a combined analytical and numerical approach, we apply our results to both a normal form model for elliptic bursting and to a biophysically-based model for neurons of the basal ganglia. We find that, depending on the period and amplitude of inputs, the response can either appear chaotic (with provably positive Lyaponov exponent for the associated circle maps), or periodic with a broad range of phase-locked periods. Throughout, we discuss the critical un...

  4. The Infrared Counterpart of the X-ray Burster KS 1731-260

    CERN Document Server

    Mignani, R P; Mirabel, F; Mereghetti, S

    2002-01-01

    We present JK' infrared images of the X-ray transient KS 1731--260, obtained in 1997 and in 1998 with IRAC2b at the ESO/MPI 2.2-m telescope at La Silla. Using as a reference the recent Chandra position, we confirm the identification of the X-ray source with the previously proposed counterpart (Wijnands et al. 2001b), for which we measure J=17.32 +/- 0.2 and K' = 16.36 +/- 0.18. The source was entering a low X-ray state at the epoch of our observations, and the accretion disk was still dominating the infrared flux. Indeed, when compared with the only published magnitudes in the J-band (Orosz et al. 2001), obtained with the source in quiescence, our photometry confirms the fading of the counterpart during the decay of the RXTE/ASM lightcurve.

  5. Optical/infrared observations of the X-ray burster KS1731-260 in quiescence

    CERN Document Server

    Zurita, C; Bandyopadhyay, R M; Cackett, E M; Groot, P J; Orosz, J A; Torres, M A P; Wijnands, R

    2010-01-01

    We performed an optical/infrared study of the counterpart of the low-mass X-ray binary KS1731-260 to test its identification and obtain information about the donor. Optical and infrared images of the counterpart of KS1731-260 were taken in two different epochs (2001 and 2007) after the source returned to quiescence in X-rays. We compared those observations with obtained when KS 1731-260 was still active. We confirm the identification of KS1731-260 with the previously proposed counterpart and improve its position to RA=17:34:13.46 and DEC=-26:05:18.60. The H-band magnitude of this candidate showed a decline of ~1.7 mags from outburst to quiescence. In 2007 April we obtained R=22.8+-0.1 and I=20.9+-0.1 for KS1731-260. Similar optical brightness was measured in June 2001 and July 2007. The intrinsic optical color R-I is consistent with spectral types from F to G for the secondary although there is a large excess over that from the secondary at the infrared wavelengths. This may be due to emission from the cooler...

  6. Detection of coherent millisecond pulsations at ~518 Hz in the LMXB Swift J1749.4-2807 (GRB060602B)

    NARCIS (Netherlands)

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

    2010-01-01

    On April 10th, it was discovered (ATel #2548) using INTEGRAL that the neutron-star X-ray binary Swift J1749.4-2807 (Wijnands et al. 2009, MNRAS, 393, 126) was again in outburst. Using follow-up Swift and INTEGRAL observations the source activity was confirmed (ATel #2548 and #2561). On April 14th, 2

  7. Data of evolutionary structure change: 1TUXA-2Q8XB [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available line> ATOM 800 CA LEU A 104 5.685 -6.148 30.982 1.00 6.75 C -map> ....81 THR CA 3.86 LEU CA -map> VAL CA 350 -map> LEU VAL ASP ARG SER V...47 3.82 VAL CA 3.81 LEU CA -map> ATOM 1101 CA GLN A 141 -0.646 -15.830 21.432 1.00 14.03 C -map>

  8. XbD Video 3, The SEEing process of qualitative data analysis

    DEFF Research Database (Denmark)

    2013-01-01

    This is the third video in the Experience-based Designing series. It presents a live classroom demonstration of a nine step qualitative data analysis process called SEEing: The process is useful for uncovering or discovering deeper layers of 'meaning' and meaning structures in an experience...

  9. XbD Video 2, Taxonomy of Experience (ToE) [Online

    DEFF Research Database (Denmark)

    2013-01-01

    This is the second video in the Experience-based Designing series: It describes the Taxonomy of Experience, a structural way of looking at human experiences of almost any kind.This hierarchical model is useful to researchers and decision makers as a general method or tool for guiding the collection...

  10. ATel 7470: Optical identification of the X-ray burster EXO 1745-248 in Terzan 5

    Science.gov (United States)

    Ferraro, F. R.; Pallanca, C.; Lanzoni, B.; Cadelano, M.; Massari, D.; Dalessandro, E.; Mucciarelli, A.

    2015-05-01

    We report on the identification of the optical counterpart to the neutron star transient EXO 1745-248 in the stellar system Terzan 5. The identification has been performed by exploiting a set of HST ACS/WFC images acquired in Director Discretionary Time on 2015 April 20 (MJD 57133), approximately 1 month after the Swift/BAT detection of an X-ray outburst from this source (Altamirano et al. ...

  11. A Chandra view of the normal S0 galaxy NGC 1332: I. An unbroken, steep power law luminosity function for the LMXB population

    CERN Document Server

    Humphrey, P J

    2004-01-01

    Chandra ACIS-S3 observations of the S0 galaxy NGC 1332 resolve much of the emission into 73 point-sources, of which 37 lie within the D_25 isophote. The unresolved emission is discussed in two companion papers. The source luminosity function (XLF) shows the break seen in other early-type galaxies at \\~2x10^{38}ergs/s. After correcting for detection incompleteness due to source confusion and contamination from diffuse emission, the break vanishes and the data are well-described as a single power law. This casts further doubt on there being a ``universal'' XLF break in such galaxies dividing neutron-star and black-hole systems. The slope of the differential XLF (dN/dL), beta=2.7+/-0.5, is steeper than has been found for analogous fits of other early-type galaxies but resembles what is generally seen at high luminosities. Two of the sources within D_25 are ULX, although neither have L_X>2x 10^{39} ergs/s. The absence of very luminous ULX in early-type galaxies suggests a break in the XLF slope at ~1-2x 10^{39} e...

  12. VizieR Online Data Catalog: Eclipsing LMXB at the center of 3FGL J0427.9-6704 (Strader+, 2016)

    Science.gov (United States)

    Strader, J.; Li, K.-L.; Chomiuk, L.; Heinke, C. O.; Udalski, A.; Peacock, M.; Shishkovsky, L.; Tremou, E.

    2017-01-01

    We converted the OGLE instrumental magnitudes i and v into standard I and V filters using the equations I=i-0.338-0.0047(v-i) and V=v-0.066-0.072(v-i), with (v-i) assumed from a smoothed version of the light curve for epochs with only one filter available. We also converted the OGLE UTC HJD values into Barycentric Julian Date (BJD) on the Barycentric Dynamical Time (TDB) system. The OGLE-IV photometry comprise 368 epochs in I and 28 epochs in V, spanning 2010 March 07 to 2015 November 29 (Udalski+ 2015AcA....65....1U). >From 2016 January 16 to May 1 (UT), we obtained optical BVI and near-IR H photometry of the source on most clear nights using ANDICAM on the SMARTS 1.3m telescope at CTIO. On a few nights multiple sets of observations were taken; the total number of epochs was 62-64 per band, depending on the band. The exposure time in each BVI was 300s; the on-source exposure time in H varied but was typically 500-600s. (1 data file).

  13. NuSTAR and XMM-Newton observations of 1e1743.1-2843: indications of a neutron star LMXB nature of the compact object

    DEFF Research Database (Denmark)

    Lotti, Simone; Natalucci, Lorenzo; Mori, Kaya;

    2016-01-01

    We report on the results of NuSTAR and XMM-Newton observations of the persistent X-ray source 1E1743.1-2843, located in the Galactic Center region. The source was observed between 2012 September and October by NuSTAR and XMM-Newton, providing almost simultaneous observations in the hard and soft X......-ray bands. The high X-ray luminosity points to the presence of an accreting compact object. We analyze the possibilities of this accreting compact object being either a neutron star (NS) or a black hole, and conclude that the joint XMM-Newton and NuSTAR spectrum from 0.3 to 40 keV fits a blackbody spectrum...

  14. HST observations rule out the association between Cir X-1 and SNR G321.9-0.3

    CERN Document Server

    Mignani, R P; Caraveo, P A; Mirabel, I F

    2002-01-01

    Cir X-1 is one of the most intriguing galactic X-ray sources. It is a ~16.6 days variable X/radio source, a type-I X-ray burster and a QPO emitter. In spite of an uncertain optical counterpart classification, all these properties identify the source as an LMXB. The morphology of the surrounding radio nebula has suggested an association with the nearby (~25 arcmin) SNR G321.9-0.3, implying that Cir X-1 is a runaway binary originated from the supernova explosion 10^5 years ago. To investigate this hypothesis, we carried out a proper motion measurement of the Cir X-1 m ~19 optical counterpart using a set of HST/WFC and WFPC2 observations taken ~8.6 years apart. We obtained a 3 sigma upper limit of ~5 mas/yr on the source proper motion. Since the runaway hypothesis would have implied a proper motion due North ranging between 15 and 75 mas/yr, depending on the actual age of the SNR, our result definitively rules out the association between Cir X-1 and SNR G321.9-0.3.

  15. Designing for 'meaningful' patient experience using Xperience-based designing (XbD): A new twist on a familiar approach

    DEFF Research Database (Denmark)

    Coxon, Ian Robert

    2013-01-01

    A major reform program has been instigated within the Danish Health system aimed at establishing Super-hospitals to replace smaller facilities (GE, 2013). This revolutionary change is expected to be achieved by reducing both the number and duration of patient stays in hospitals. Realising this goal...... to practitioners who value the patient experience as an important aspect of designing-4-health in terms of products, services and systems...

  16. Inpatients’ opinions on a hospital in Portugal [v1; ref status: indexed, http://f1000r.es/xb

    Directory of Open Access Journals (Sweden)

    Carina C Silva

    2013-02-01

    Full Text Available Background: Little is known about the relationship between the opinions of inpatients and the degree to which hospitals are improving in performance over time. The aim of this study was to determine the personal assessment level of inpatients or their representatives regarding aspects of health care in an internal medicine ward. Methods: We carried out a questionnaire in September 2011 with 284 discharged patients and patient representatives, focusing on their opinions about the department, health professionals and amenities, with response options ranging from 1 (very bad to 5 (very good. The relationships between domains from the questionnaire and socio-demographic factors were examined using a t-test and one-way ANOVA. Results: The response rate was 78%. The patients showed a slightly higher mean score (m for factors in the medical care domain than did the patient representatives (m = 4.51 vs. m = 4.27; p = 0.014. The mean score of all the items in all domains was 4.24; this allowed us to determine the difference from the overall mean (DIFM for medical care (DIFM = 0.18; p = 0.000, foods (DIFM = –0.31; p = 0.000, diagnostic tests (DIFM = –0.15; p = 0.036 and transport (DIFM = –0.41; p = 0.000. Respondents with a medium or higher educational level gave lower scores to the domains food (m = 3.74; p = 0.004, diagnostic tests (m = 3.72; p = 0.04 and transport (m = 3.62; p = 0.025 than those with lower educational levels. The domains facilities (m = 2.4; p = 0.04 and diagnostic tests (m = 3.63; p = 0.009 were given lower scores by those aged <50 years compared with older respondents. Conclusions: Our findings suggest that the evaluation of the responders will allow the hospital management to make improvements in the quality of care.

  17. $X_{b}$ Search and Measurement of the $Y(1)$, $(2S)$ and $Y(3S)$ Polarization

    Energy Technology Data Exchange (ETDEWEB)

    Marino, Claudia [Karlsruhe Inst. of Technology (KIT) (Germany)

    2009-10-30

    There are two studies presented in this analysis. The rst one is the measurement of the Υ(1S), Υ(2S) and Υ(3S) polarization in two orthogonal frames: the helicity and the Collins-Soper frame. The second is the search for a possible bottom counterpart of the X(3872) which would show up as a narrow resonance in the Υ(1S)π+ π- nal state.

  18. Low-temperature and high-pressure xB5SR study of the strongly correlated CeNiSn Hx compounds

    Science.gov (United States)

    Isnard, O.; Rusu, C.; Dudric, R.; Andreica, D.; Amato, A.; Chevalier, B.

    2016-06-01

    Hydrogen insertion in the CeNiSn Kondo semiconductor induces antiferromagnetic ordering for CeNiSnH below TN=4.5 K whereas CeNiSn H1.8 orders ferromagnetically below TC=7.0 K . We present a detailed investigation of these CeNiSn Hx compounds by means of muon spin spectroscopy performed at both ambient and high pressure (up to 23 kbar). It is shown that both magnetic ordering temperatures are sensitive to the applied pressure but in opposite directions, i.e., d/TC d p =-0.17 K kba r-1 for CeNiSn H1.8 and d/TN d p =0.016 K kba r-1 for CeNiSnH, respectively. This difference is discussed in terms of hydrogen-induced modification of the balance between the Ruderman-Kittel-Kasuya-Yosida (RKKY) and the Kondo interactions. The µSR study demonstrates that the CeNiSnH and CeNiSn H1.8 are on different sides of Doniach's dome. The behavior of the CeNiSn H1.8 is interpreted as resulting from an increase of the hybridization between 4 f and 5 d states and a concomitant steep increase of the Kondo temperature upon applying pressure. In the quest for a quantum critical point, an estimated pressure of about 35 kbar is expected to suppress the magnetism in CeNiSn H1.8 .

  19. Preparation and Characterization of Mg1-xB2 Bulk Samples and Cu/Nb Sheathed Wires with Low Grade Amorphous Boron Powder

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Alexiou, Aikaterini; Rubesova, Katerina;

    2014-01-01

    MgB2 bulk and wire samples were prepared using cheap, low grade amorphous boron powders. Based on chemical analysis performed on the starting reagents, three nominal stoichiometries were studied. It was found that the structural and superconducting properties of the bulk samples were not affected...

  20. 稀土硼化物LaxCe1-xB6亚微米粉的制备及光吸收研究∗%Synthesis and optical absorption prop erties of LaxCe1-xB6 submicron powders

    Institute of Scientific and Technical Information of China (English)

    包黎红; 朝洛蒙; 伟伟; 特古斯

    2015-01-01

    以稀土氧化物La2 O3和CeO2为稀土源,以NaBH4为硼源在真空环境中通过固相反应成功制备出了分散性好的单相三元LaxCe1−xB6亚微米粉。系统研究了掺杂元素La对CeB6物相,微观结构及光吸收性能的影响。实验结果表明, La元素的掺杂没有改变CeB6的物相和晶体结构,而是无序替代了Ce原子晶位。光吸收结果表明,随着La掺杂量的增加LaxCe1−xB6分散液吸收谷波长从620 nm减小到610 nm出现了蓝移现象。%According to original knowledge, lanthanum hexaboride (LaB6) as an excellent thermionic electron emitter is char-acterized by a low work function, a high emission density, and a high brightness. Recently, much attention has been drawn to its another excellent optical properties: strong light absorption in near infrared rays (NIR), and transparency in visible light (VL), which result from the free electron plasmon resonance. However, up to now the optical properties and syntheses of ternary rare-earth hexaborides have been very rarely reported in the literature. In this paper, ternary LaxCe1−xB6 submicron crystallines are successfully synthesized using a solid-state reaction, in which La2O3 and CeO2 are used as rare-earth sources and NaBH4 as boron sources in a continuous vacuum condition. Effects of La doping content on the LaxCe1−xB6 phase composition, microstructure, and optical absorption properties are investigated by X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). It is found that all the synthesized samples are composed of CaB6-type single-phase alloy with a space group P m¯3m at the reaction temperature of 1200 ◦C held by 2 h. The SEM results indicate that the cubic-shaped ternary LaxCe1−xB6 crystals with a mean size of 200 nm are obtained and the energy dispersive spectrometer results confirm that the La atoms are randomly distributed at the lattice sites of CeB6. High resolution transmission electron microscope images reveal the single-crystalline nature, and the FFT pattern indicates the lattice fringe d = 0.42 nm which agrees well with the (100) crystal plane. EDS analysis of TEM also indicates the La element has been doped into CeB6. And the optical absorption result shows that the absorption valley of CeB6 is 62 nm. With increasing La doping content to x = 0.6 and 0.8, the absorption valleys of La0.6Ce0.4B6 and La0.8Ce0.2B6 decrease to 613 and 610 nm respectively indicating the blueshifts of the wavelength of absorption valley From the view point of practical application, the tunable characteristic of LaxCe1−xB6 may extend the optical applications in improving the efficiency of organic photovoltaics, replacing the expensive gold and silver nanoparticles, which may have a good usage in optical filters.

  1. Tunable deep ultraviolet femtosecond sum frequency laser based on Ba1-xB2-y-zO4SixAlyGaz crystal%Ba1-xB2-y-z O4SixAly Gaz晶体和频可调谐深紫外飞秒激光器∗

    Institute of Scientific and Technical Information of China (English)

    孟祥昊; 刘华刚; 黄见洪; 戴殊韬; 邓晶; 阮开明; 陈金明; 林文雄

    2015-01-01

    Tunable coherent deep ultraviolet (DUV) light sources, especially ultrashort pulse DUV lasers have great appli-cations in the fields of time-resolved, material processing, spectroscopy, laser spectroscopy and laser fusion. In the UV region, the best choice of generating the laser pulses in the femtosecond or picosecond regime is the frequency up-conversation technique based on second order nonlinearities. Over the past three decades, quite a lot of nonlinear crystals, such as LiB3O5, β-BaB2O4, KBe2BO3F2 and Ba1−xB2−y−zO4SixAlyGaz have been developed and employed for gener-ating the femtosecond pulses in the blue, ultraviolet, and even the deep-ultraviolet region. A tunable deep ultraviolet femtosecond laser is experimentally studied based on the new nonlinear crystal Ba1−xB2−y−zO4SixAlyGaz It is a kind of low-temperature phase barium metaborate single crystal belonging to a trigonal system, doped with one or more elements selected from Si, Al and Ga. As an optimized β-BaB2O4 crystal, Ba1−xB2−y−zO4SixAlyGaz completely overcomes the shortcomings of deliquescence compared withβ-BaB2O4, and its nonlinear efficiency and optical damage threshold have also been greatly improved. Using two crystals as second harmonic generation is to compensate for the spatial walk-off effect and the light path walk-off due to refraction effect The optical axis of the second Ba1−xB2−y−zO4SixAlyGaz is twice the phase matching angle with respect to the first one. In a femtosecond regime, short pulse provides high efficient frequency conversation due to their high peak powers, but the group velocity mismatch is a cognitive factor to limit conversion efficiency. It is obvious that after the frequency doubling, the second harmonic pulse and fundamental pulse separate from each other. The second harmonic pulse lags behind the fundamental pulse as they propagate through the crystal and the second harmonic pulse is broadened into a longer pulse duration than the fundamental pulse The method to compensate for the group velocity mismatch is to adjust the path length between the fundamental and second harmonic pulse by means of time delay line. It consists of beam splitters and mirrors. Tunable deep ultraviolet pulse within a wavelength range from 192.5 to 210 nm is produced, with a maximum average power of 5.8 mW, under a 2.78 W fundamental power. The average power of second harmonic, third harmonic and fourth harmonic are 1.28 W, 194 mW and 5.8 mW at the fundamental wavelength of 800 nm, corresponding to conversion efficiencies of 46.14%, 15.16% and 3%from the previous stage, respectively. The duration of the third harmonic pulse is 640.4 fs at 266.7 nm as measured by the cross-correlation technique.%介绍了一种基于新型非线性晶体Ba1−xB2−y−zO4SixAlyGaz 的可调谐深紫外飞秒激光光源.从理论上分析了基频光和倍频光在通过非线性晶体时所造成的空间走离和群速度失配,为了补偿空间走离以及波长调谐过程中晶体折射造成的光束偏离现象,将两块相同的倍频晶体成镜像放置来产生二次谐波.并调节延迟线的长度来补偿基频光和倍频光之间的群速度失配,从而提高和频转换效率.然后通过和频方式进行三倍频和四倍频来突破晶体相位匹配条件的限制,产生了波长低于200 nm的深紫外飞秒激光.利用钛宝石激光器提供基频光光源,最终在250—300 nm,192.5—210 nm范围内获得了高重频、可调谐超短脉冲紫外和深紫外激光.并在基频光波长为800 nm时,得到的二倍频、三倍频和四倍频的功率分别为1.28 W,194 mW和5.8 mW,相对于前一级的转换效率依次为46.14%,15.16%和3%.采用互相关法测量得到266.7 nm紫外激光的脉冲宽度约为640.4 fs.

  2. A soft X-ray spectral episode for the Clocked Burster, GS 1826-24 as measured by Swift and NuSTAR

    DEFF Research Database (Denmark)

    Chenevez, J.; Galloway, D.K.; in ’t Zand, J.J.M.

    2016-01-01

    . The burst profiles and recurrence times vary significantly, ruling out the regular bursts that are typical for this source. One burst exhibited photospheric radius expansion and we estimate the source distance as (5.7 ±0.2) ξb-1/2kpc, where ξb parameterizes the possible anisotropy of the burst emission...

  3. New technique for a simultaneous estimation of the level density and radiative strength functions of dipole transitions at E sub e sub x<=B sub n -0.5 MeV

    CERN Document Server

    Khitrov, V A

    2001-01-01

    The new, model-independent method to estimate simultaneously the level densities excited in the (n,gamma) reaction and the radiative strength functions of dipole transitions is developed. The method can be applied for any nucleus and reaction followed by cascade gamma-emission. It is just necessary to measure the intensities of two-step gamma-cascades depopulating one or several high-excited states and determine the quanta ordering in the main portion of the observed cascades. The method provides a sufficiently narrow interval of most probable densities of levels with given J suppi and radiative strength functions of dipole transitions populating them.

  4. 机械球磨MgH2-xB复合材料的放氢性能%Hydrogen Desorption Property of the Ball-milled MgH2-xB Composites

    Institute of Scientific and Technical Information of China (English)

    王庆庆; 赵刚; 斯庭智; 张庆安

    2010-01-01

    通过机械球磨制备MgH2-xB(x=0.0,0.2,0.5,1.0,2.0)复合储氢材料.除非晶B外,复合材料均由四方晶系MgH2主相、少量的正交晶系MgH2和MgO相组成.随非晶B添加量的增加,复合材料的放氢速度增快.其中,MgH2-2B复合材料具有最佳的放氢动力学性能,在553 K,240min内放氢质量分数达2.59%.非晶B分布在MgH2颗粒表层,作为氢扩散的通道扩大了脱氢反应的接触面积,从而提高了MgH2-2B复合材料的放氢动力学性能.

  5. Asymptotic distribution of singular values of powers of random matrices

    CERN Document Server

    Alexeev, Nikita; Tikhomirov, Alexander

    2010-01-01

    Let $x$ be a complex random variable such that ${\\E {x}=0}$, ${\\E |x|^2=1}$, ${\\E |x|^{4} < \\infty}$. Let $x_{ij}$, $i,j \\in \\{1,2,...\\}$ be independet copies of $x$. Let ${\\Xb=(N^{-1/2}x_{ij})}$, $1\\leq i,j \\leq N$ be a random matrix. Writing $\\Xb^*$ for the adjoint matrix of $\\Xb$, consider the product $\\Xb^m{\\Xb^*}^m$ with some $m \\in \\{1,2,...\\}$. The matrix $\\Xb^m{\\Xb^*}^m$ is Hermitian positive semi-definite. Let $\\lambda_1,\\lambda_2,...,\\lambda_N$ be eigenvalues of $\\Xb^m{\\Xb^*}^m$ (or squared singular values of the matrix $\\Xb^m$). In this paper we find the asymptotic distribution function \\[ G^{(m)}(x)=\\lim_{N\\to\\infty}\\E{F_N^{(m)}(x)} \\] of the empirical distribution function \\[ {F_N^{(m)}(x)} = N^{-1} \\sum_{k=1}^N {\\mathbb{I}{\\{\\lambda_k \\leq x\\}}}, \\] where $\\mathbb{I} \\{A\\}$ stands for the indicator function of event $A$. The moments of $G^{(m)}$ satisfy \\[ M^{(m)}_p=\\int_{\\mathbb{R}}{x^p dG^{(m)}(x)}=\\frac{1}{mp+1}\\binom{mp+p}{p}. \\] In Free Probability Theory $M^{(m)}_p$ are known as Fuss--C...

  6. Highly interpenetrated supramolecular networks supported by N...I halogen bonding.

    Science.gov (United States)

    Metrangolo, Pierangelo; Meyer, Franck; Pilati, Tullio; Proserpio, Davide M; Resnati, Giuseppe

    2007-01-01

    Halogen bonding (XB) has been used to assemble tetrakis(4-pyridyl)pentaerythritol (tetradentate XB acceptor) with different alpha,omega-diiodoperfluoroalkanes (bidentate XB donors) or tetrakis(4-iodotetrafluorophenyl)pentaerythritol (tetradentate XB donor). The remarkable linearity of the XB formed, the rodlike character of alpha,omega-diiodoperfluoroalkanes and the mutual complementarities of pentaerythritol partners, translate the three-dimensional character of the XB acceptor into open primary networks, which interpenetrate to avoid the presence of voids and to ensure segregation of the modules. Two-dimensional (2D) square 4(4) layers (sql) with fourfold and fivefold interpenetration, as well as an eightfold diamondoid network (dia) of class Ia and a remarkable tenfold dia network of class IIIa, have been obtained.

  7. Mapping QTLs for Fertility Restoration of Different Cytoplasmic Male Sterility Types in Rice Using Two Oryza sativa ×O. rufipogon Backcross Inbred Line Populations

    OpenAIRE

    Biao-lin Hu; Jian-kun Xie; Yong Wan; Jin-wei Zhang; Fan-tao Zhang; Xia Li

    2016-01-01

    Hybrid rice breeding using cytoplasmic male sterility/fertility restoration (CMS/Rf) systems plays an important role in ensuring global food security. Two backcross inbred line (BIL) populations derived from either Xieqingzao B (XB)//XB/Dongxiang wild rice (DWR) (XXD) or XB//DWR/XB (XDX) were used to detect quantitative trait loci (QTLs) for fertility restoration of Dwarf wild abortive- (DA-), Indonesia Paddy- (ID-), and DWR-type CMS in rice. Lines with ID- and DA-type CMS were testcrossed wi...

  8. Impact of combined β-glucanase and xylanase enzymes on growth performance, nutrients utilization and gut microbiota in broiler chickens fed corn or wheat-based diets.

    Science.gov (United States)

    Munyaka, P M; Nandha, N K; Kiarie, E; Nyachoti, C M; Khafipour, E

    2016-03-01

    The effects of a xylanase and β-glucanase (XB) blend (2,500 U of xylanase and 250 U of β-glucanase per kg of complete feed) on growth performance, nutrients utilization and digesta microbiota in broiler chickens were investigated. A total of 140 day-old male Ross 308 broiler chicks were randomly assigned to 7 replicate cages and fed experimental diets. Diets were based on either corn or wheat without or with supplemental XB. Performance was monitored weekly and excreta were collected from d 17 to 20 for nutrients digestibility and AMEn measurements. On d 21, jejunal contents were collected for viscosity determination whereas ileal and cecal contents were obtained for microbial analysis by Illumina sequencing. Microbial data were analyzed using QIIME and PLS-DA whilst other data were analyzed using SAS. Birds fed wheat diets had higher (P diet whilst birds fed XB had better BWG (4%) and FCR (7%) than birds fed non-XB diets. Birds fed wheat diet had higher (P diet. XB reduced (P diet (-31%) than in corn-based diet (-10%). Birds fed wheat-based diet with XB had higher (3.5%) starch digestibility than birds fed this diet without XB. Janthinobacterium was associated with non-XB corn-based diet, whereas Ruminococcus, Lachnospiraceae, Lactobacillaceae, Peptostreptococcaceae, Clostridiales, Acidovorax and Blautia were associated with XB corn-based diet in the ileum. A relatively similar microbiome clustering was observed in wheat-based treatments in the cecum. There were no significant (P ≥ 0.05) correlations between selected ileal or cecal bacterial taxa and AMEn. Diet impacted growth performance but XB was efficacious across diet types, implying that degradation of dietary fibrous components by feed enzymes may stimulate performance in young birds. Data provided significant insight on ileal and cecal microbial profile associated with the dietary types and XB; however their functional roles require further investigations.

  9. Designer Metallic Acceptor-Containing Halogen Bonding: General Strategies.

    Science.gov (United States)

    Zhang, Xinxing; Bowen, Kit H

    2017-03-13

    Being electrostatic interactions in nature, hydrogen bonding (HB) and halogen bonding (XB) are considered to be two parallel worlds. In principle, all the applications that HB has could also be applied to XB. However, there has been no report on a metallic XB acceptor but metal anions have been observed to be good HB acceptors. This missing mosaic piece of XB is because common metal anions are reactive for XB donors. In view of this, we propose two strategies for designing metallic acceptor-containing XB using ab initio calculations. The first one is to utilize a metal cluster anion with a high electron detachment energy, such as the superatom, Al13- as the XB acceptor. The second strategy is to design a ligand passivated/protected metal core while it still can maintain the negative charge; several exotic clusters, such as PtH5-, PtZnH5- and PtMgH5-, are utilized as examples. Based on these two strategies, we anticipate that more metallic acceptor-containing XB will be discovered.

  10. Timing Observations of PSR J1023+0038 During a Low-mass X-Ray Binary State

    Science.gov (United States)

    Jaodand, Amruta; Archibald, Anne M.; Hessels, Jason W. T.; Bogdanov, Slavko; D’Angelo, Caroline R.; Patruno, Alessandro; Bassa, Cees; Deller, Adam T.

    2016-10-01

    Transitional millisecond pulsars (tMSPs) switch, on roughly multi-year timescales, between rotation-powered radio millisecond pulsar (RMSP) and accretion-powered low-mass X-ray binary (LMXB) states. The tMSPs have raised several questions related to the nature of accretion flow in their LMXB state and the mechanism that causes the state switch. The discovery of coherent X-ray pulsations from PSR J1023+0038 (while in the LMXB state) provides us with the first opportunity to perform timing observations and to compare the neutron star’s spin variation during this state to the measured spin-down in the RMSP state. Whereas the X-ray pulsations in the LMXB state likely indicate that some material is accreting onto the neutron star’s magnetic polar caps, radio continuum observations indicate the presence of an outflow. The fraction of the inflowing material being ejected is not clear, but it may be much larger than that reaching the neutron star’s surface. Timing observations can measure the total torque on the neutron star. We have phase-connected nine XMM-Newton observations of PSR J1023+0038 over the last 2.5 years of the LMXB state to establish a precise measurement of spin evolution. We find that the average spin-down rate as an LMXB is 26.8 ± 0.4% faster than the rate (‑2.39 × 10‑15 Hz s‑1) determined during the RMSP state. This shows that negative angular momentum contributions (dipolar magnetic braking, and outflow) exceed positive ones (accreted material), and suggests that the pulsar wind continues to operate at a largely unmodified level. We discuss implications of this tight observational constraint in the context of possible accretion models.

  11. The spectra of accretion discs in low-mass X-ray binaries

    CERN Document Server

    Ross, R R

    1995-01-01

    We present self-consistent models for the radiative transfer in Shakura-Sunyaev accretion discs in bright low-mass X-ray binaries (LMXB). Our calculations include the full effects of incoherent Compton scattering and the vertical temperature structure within the disc, as well as the effects of Doppler blurring and gravitational redshift. We find that the observed X-ray spectra are well fit by exponentially cutoff power-law models. The difference between the observed total spectrum and our calculated disc spectrum should reveal the spectrum of the disc/neutron star boundary layer and other emitting regions considered to be present in LMXB.

  12. M31 globular cluster structures and the presence of X-ray binaries

    CERN Document Server

    Agar, J R R

    2013-01-01

    [Abridged] M31 has several times more globular clusters (GCs) than the Milky Way. It contains a correspondingly larger number of low mass X-ray binaries (LMXBs) associated with GCs, and can be used to investigate the GC properties which lead to X-ray binary formation. The best tracer of the spatial structure of M31 GCs is high-resolution imaging from the Hubble Space Telescope, and we have used HST data to derive structural parameters for 29 LMXB-hosting M31 GCs. These measurements are combined with structural parameters from the literature for a total of 41 (of 50 known) LMXB GCs and a comparison sample of 65 non-LMXB GCs. Structural parameters measured in blue bandpasses are found to show smaller core radii and higher concentrations than those measured in red bandpasses; this difference is enhanced in LMXB clusters and could be related to stellar population differences. Clusters with LMXBs show higher collision rates for their mass compared to those without LMXBs and collision rates estimated at the core ra...

  13. The Milky Way in X-rays for an outside observer Log(N)-Log(S) and Luminosity Function of X-ray binaries from RXTE\\/ASM data

    CERN Document Server

    Grimm, H J; Sunyaev, R A

    2002-01-01

    We study the Log(N)-Log(S) and X-ray luminosity function in the 2-10 keV energy band, and the spatial (3-D) distribution of bright, log(L_X) > 34-35 erg/s, X-ray binaries in the Milky Way. In agreement with theoretical expectations and earlier results we found significant differences between the spatial distributions of low (LMXB) and high (HMXB) mass X-ray binaries. The volume density of LMXB sources peaks strongly at the Galactic Bulge. HMXBs tend to avoid the inner 3-4 kpc of the Galaxy, HMXBs are more concentrated towards the Galactic Plane and show clear signatures of the spiral structure in their spatial distribution. LMXB sources have a flatter Log(N)-Log(S) distribution and luminosity function than HMXBs. The integrated 2-10 keV luminosities of X-ray binaries, averaged over 1996--2000, are 2-3 * 10^39 (LMXB) and 2-3 * 10^38 (HMXB) erg/s. Normalised to the stellar mass and the star formation rate, respectively, these correspond to 5 * 10^28 erg/s/M_sol for LMXBs and 5 * 10^37 erg/s/(M_sol/yr) for HMXBs...

  14. Timing Observations of PSR J1023+0038 During a Low-Mass X-ray Binary State

    CERN Document Server

    Jaodand, Amruta; Hessels, Jason W T; Bogdanov, Slavko; D'Angelo, Caroline R; Patruno, Alessandro; Bassa, Cees; Deller, Adam T

    2016-01-01

    Transitional millisecond pulsars (tMSPs) switch, on roughly multi-year timescales, between rotation-powered radio millisecond pulsar (RMSP) and accretion-powered low-mass X-ray binary (LMXB) states. The tMSPs have raised several questions related to the nature of accretion flow in their LMXB state and the mechanism that causes the state switch. The discovery of coherent X-ray pulsations from PSR J1023+0038 (while in the LMXB state) provides us with the first opportunity to perform timing observations and to compare the neutron star's spin variation during this state to the measured spin-down in the RMSP state. Whereas the X-ray pulsations in the LMXB state likely indicate that some material is accreting onto the neutron star's magnetic polar caps, radio continuum observations indicate the presence of an outflow. The fraction of the inflowing material being ejected is not clear, but it may be much larger than that reaching the neutron star's surface. Timing observations can measure the total torque on the neut...

  15. Spectral states evolution of 4U 1728-34 observed by INTEGRAL and RXTE : non-thermal component detection

    NARCIS (Netherlands)

    Tarana, A.; Belloni, T.; Bazzano, A.; Mendez, M.; Ubertini, P.

    2011-01-01

    We report results of a one-year monitoring of the low-mass X-ray binary (LMXB) source (atoll type) 4U 1728-34 with INTEGRAL and RXTE. Three time intervals were covered by INTEGRAL, during which the source showed strong spectral evolution. We studied the broad-band X-ray spectra in detail by fitting

  16. A Continuum of Accretion Burst Behavior in Young Stars Observed by K2

    Science.gov (United States)

    Cody, Ann Marie; Hillenbrand, Lynne A.; David, Trevor J.; Carpenter, John M.; Everett, Mark E.; Howell, Steve B.

    2017-02-01

    We present 29 likely members of the young ρ Oph or Upper Sco regions of recent star formation that exhibit “accretion burst” type light curves in K2 time series photometry. The bursters were identified by visual examination of their ∼80-day light curves, though all satisfy the Mtheory of pre-main sequence accretion history.

  17. Bifurcation of a Saddle-Node Limit Cycle with Homoclinic Orbits Satisfying the Small Lobe Condition in a Leech Neuron Model

    Institute of Scientific and Technical Information of China (English)

    YOOER Chi-Feng; XU Jian-Xue; ZHANG Xin-Hua

    2009-01-01

    Mechanism of period-adding cascades with chaos in a reduced leech neuron model is suggested as the bifurcation of a saddle-node limit cycle with homoclinic orbits satisfying the "small lobe condition",instead of the blue-sky catastrophe.In every spiking adding,the new spike emerges at the end of the spiking phase of the bursters.

  18. INTEGRAL monitoring of unusually long X-ray bursts

    DEFF Research Database (Denmark)

    of the known X-ray bursters are frequently observed by INTEGRAL, in particular in the frame of the Key Programmes. Taking advantage of the INTEGRAL instrumentation, an international collaboration led by the JEM-X team at the Danish National Space Institute has been monitoring the occurrence of uncommon burst...

  19. INTEGRAL monitoring of unusually long X-ray bursts

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Falanga, M.; Kuulkers, E.;

    2008-01-01

    X-ray bursts are thermonuclear explosions on the surface of accreting neutron stars in X-ray binaries. As most of the known X-ray bursters are frequently observed by INTEGRAL, an international collaboration have been taking advantage of its instrumentation to specifically monitor the occurrence...

  20. Hubble Space Telescope STIS observations of GRB 000301C: CCD imaging and near-ultraviolet MAMA spectroscopy

    DEFF Research Database (Denmark)

    Smette, A.; Fruchter, A.S.; Gull, T.R.

    2001-01-01

    We present Space Telescope Imaging Spectrograph observations of the optical transient (OT) counterpart of the c-ray burster GRB 000301C obtained 5 days after the burst, on 2000 March 6. CCD clear-aperture imaging reveals a R similar or equal to 21.50 +/- 0.15 source with no apparent host galaxy. ...

  1. THE NEAREST BISYMMETRIC SOLUTIONS OF LINEAR MATRIX EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    Zhen-yun Peng; Xi-yan Hu; Lei Zhang

    2004-01-01

    The necessary and sufficient conditions for the existence of and the expressions for bismmetric soutions of the matrix equation(Ⅰ)A1X1B1+A2X2B2+…AkXkBk=D,(Ⅱ)A1XB1+A2XB2+…+AkXBk=D and (Ⅲ)(A1XB1,A2XB2,…,AkXBK)=(D1,D2,…,Dk) are derived by using kronecker product and Moore-Penrose generalized inverse of matrices. In addition, in corresponding solution set of the matrix equations, the explicit expression of the nearest matrix to a given matrix in the Frobenius norm is given.Numerical methods and numerical experiments of finding the nearest solutions are also provided.

  2. Drug: D08423 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available on [BR:br08302] Antineoplastics Alkylating Agents Procarbazine D08423 Procarbazine (INN) Antineoplastics [BR...ylhydrazines L01XB01 Procarbazine D08423 Procarbazine (INN) USP drug classificati

  3. Ranks of the Common Solution to Six Quaternion Matrix Equations

    Institute of Scientific and Technical Information of China (English)

    Qing-wen Wang; Yan Zhou; Qin Zhang

    2011-01-01

    A new expression is established for the common solution to six classical linear quaternion matrix equations A1X = C1, XB1 = C3, A2X = C2, XB2 = C4, A3XB3 = C5, A4XB4 = C6 which was investigated recently by Wang, Chang and Ning (Q. Wang, H. Chang, Q. Ning, The common solution to six quaternion matrix equations with applications, Appl. Math. Comput. 195: 721-732 (2008)). Formulas are derived for the maximal and minimal ranks of the common solution to this system. Moreover, corresponding results on some special cases are presented. As an application, a necessary and sufficient condition is presented for the invariance of the rank of the general solution to this system. Some known results can be regarded as the special cases of the results in this paper.

  4. X(3872) and the search for its bottomonium counterpart at the LHC

    CERN Document Server

    Toms, Konstantin; The ATLAS collaboration

    2016-01-01

    X(3872) history and theoretical status overview. ATLAS study of the ψ(2S) and X(3872) production. Search for X(3872) bottomonium counterpart by ATLAS. Search for Xb at CMS. Determination of X(3872) quantum numbers at LHCb.

  5. Alternativas para favorecer la polinización y producción de semilla del híbrido h-311 de maíz

    Directory of Open Access Journals (Sweden)

    Alejandro Espinosa

    2001-01-01

    Full Text Available Alternativas para favorecer la polinización y producción de semilla del híbrido H-311 de maíz. En la producción de semilla de híbridos de maíz es fundamental la coincidencia en floración de los progenitores y la disposición de los estigmas con respecto a las panojas que emiten polen. El híbrido de maíz H-311, se recomienda en México para siembras de riego, en alturas de 1200 a 1800 msnm. El orden de cruza inicial fue: (B16XB17 X (B32XB33; sin embargo, se cambio al orden inverso, es decir, (B32XB33 X (B16XB17, debido a mayor productividad y semilla de buena calidad física. La cruza simple (B16XB17 es enana (braquítico, al no haber suficiente viento en la época de polinización, se dificulta el cruzamiento y se requiere levantar el polen con mochilas de motor, la cruza simple B16XB17, rinde de 4,5 a 5,5 t/ha de semilla contra 6,0 a 7,5 t/ha de la cruza simple B32XB33; La cruza simple B16XB17, responde con alargamiento del porte por la influencia del tratamientos, con ácido giberélico (Activol, 20, 40 y 60 ppm, dos dosis de Cloruro de Mepiquat (PIX, 1 y 2 lt/ha, así como tres niveles de fertilización (400-70-30, 150-70-30 y 150- 300-30. En rendimiento hubo un efecto positivo por el manejo de ambos progenitores con diferentes fertilizaciones así como aplicación de fitohormonas, al aplicar ácido giberélico (20 ppm, el rendimiento se incrementó en 250,3% y 211,8% para las cruzas simples B32XB33 y B16XB17 respectivamente. La altura de planta de B16XB17 fue ligeramente afectada (106,0% con ácido giberélico, 40 ppm

  6. X(3872) and its bottomonium counterpart at ATLAS

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00218332; The ATLAS collaboration

    2016-01-01

    We present the measurement of the differential cross-section of the X(3872) state through its decays to $J/\\psi \\pi^+ \\pi^-$ final state . The cross-section was extracted for both prompt and non-prompt production. The existence of the X(3872) suggests the presence of its bottomonium counterpart $X_b$. Search for $X_b$ with the ATLAS experiment in several final states, including $\\Upsilon \\pi^+ \\pi^-$, is presented.

  7. Global analysis of ankyrin repeat domain C3HC4-type RING finger gene family in plants.

    Directory of Open Access Journals (Sweden)

    Xiaowei Yuan

    Full Text Available Ankyrin repeat (ANK C3HC4-type RING finger (RF genes comprise a large family in plants and play important roles in various physiological processes of plant life. In this study, we identified 187 ANK C3HC4-type RF proteins from 29 species with complete genomes and named the ANK C3HC4-type RF proteins the XB3-like proteins because they are structurally related to the rice (Oryza sativa XB3. A phylogenetic relationship analysis suggested that the XB3-like genes originated from ferns, and the encoded proteins fell into 3 major groups. Among these groups, we found that the spacing between the metal ligand position 6 and 7, and the conserved residues, which was in addition to the metal ligand amino acids, in the C3HC4-type RF were different. Using a wide range of protein structural analyses, protein models were established, and all XB3-like proteins were found to contain two to seven ANKs and a C3HC4-type RF. The microarray data for the XB3-like genes of Arabidopsis, Oryza sative, Zea mays and Glycine max revealed that the expression of XB3-like genes was in different tissues and during different life stages. The preferential expression of XB3-like genes in specified tissues and the response to phytohormone and abiotic stress treatments of Arabidopsis and Zea mays not only confirmed the microarray analysis data but also demonstrated that the XB3-like proteins play roles in plant growth and development as well as in stress responses. Our data provide a very useful reference for the identification and functional analysis of members of this gene family and also provide a new method for the genome-wide analysis of gene families.

  8. A Conditional Model of Deduplication for Multi-Type Relational Data

    Science.gov (United States)

    2005-01-01

    venue deduplication. Xa and Xb are paper and venue records, respectively. Y is a binary random variable indicating duplicate records, and Rabij ... Rabij indicates whether some arbitrary relation R holds between record mentions Xai and X b j . For example, in a research paper database, Xa...represents the set of paper records, Xb represents the set venue records, Y aij indicates whether X a i and X a j are duplicates, and Rabij indicates whether

  9. Search for a new bottomonium state decaying to Υ(1S)π+π- in pp collisions at s=8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Chatrchyan, Serguei; et al.

    2013-11-01

    The results of a search for the bottomonium counterpart, denoted as $X_b$, of the exotic charmonium state X(3872) is presented. The analysis is based on a sample of pp collisions at $\\sqrt{s}$ = 8 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 20.7 inverse femtobarns. The search looks for the exclusive decay channel $X_b \\to \\Upsilon(1S) \\pi^+ \\pi^-$ followed by $\\Upsilon(1S) \\to \\mu^+ \\mu^-$. No evidence for an $X_b$ signal is observed. Upper limits are set at the 95% confidence level on the ratio of the inclusive production cross sections times the branching fractions to $\\Upsilon(1S) \\pi^+ \\pi^-$ of the $X_b$ and the $\\Upsilon$(2S). The upper limits on the ratio are in the range 0.9-5.4% for $X_b$ masses between 10 and 11 GeV. These are the first upper limits on the production of a possible $X_b$ at a hadron collider.

  10. Search for a new bottomonium state decaying to $\\Upsilon(1S)\\pi^+ \\pi^-$ in pp collisions at $\\sqrt{s}$ = 8 TeV

    CERN Document Server

    Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Christine; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Luyckx, Sten; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Staykova, Zlatka; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Kalogeropoulos, Alexis; Keaveney, James; Lowette, Steven; Maes, Michael; Olbrechts, Annik; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Favart, Laurent; Gay, Arnaud; Hreus, Tomas; Léonard, Alexandre; Marage, Pierre Edouard; Mohammadi, Abdollah; Perniè, Luca; Reis, Thomas; Seva, Tomislav; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Costantini, Silvia; Dildick, Sven; Garcia, Guillaume; Klein, Benjamin; Lellouch, Jérémie; Marinov, Andrey; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Sigamani, Michael; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Walsh, Sinead; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jez, Pavel; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Selvaggi, Michele; Vidal Marono, Miguel; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Alves, Gilvan; Correa Martins Junior, Marcos; Martins, Thiago; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Malbouisson, Helena; Malek, Magdalena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Lagana, Caio; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Xianyou; Wang, Zheng; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Yifei; Li, Qiang; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Zhang, Linlin; Zou, Wei; Avila, Carlos; Carrillo Montoya, Camilo Andres; Chaparro Sierra, Luisa Fernanda; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Mekterovic, Darko; Morovic, Srecko; Tikvica, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Ellithi Kamel, Ali; Kuotb Awad, Alaa Metwaly; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Müntel, Mait; Murumaa, Marion; Raidal, Martti; Rebane, Liis; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri

    2013-01-01

    The results of a search for the bottomonium counterpart, denoted as $X_b$, of the exotic charmonium state X(3872) is presented. The analysis is based on a sample of pp collisions at $\\sqrt{s}$ = 8 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 20.7 inverse femtobarns. The search looks for the exclusive decay channel $X_b \\to \\Upsilon(1S) \\pi^+ \\pi^-$ followed by $\\Upsilon(1S) \\to \\mu^+ \\mu^-$. No evidence for an $X_b$ signal is observed. Upper limits are set at the 95% confidence level on the ratio of the inclusive production cross sections times the branching fractions to $\\Upsilon(1S) \\pi^+ \\pi^-$ of the $X_b$ and the $\\Upsilon$(2S). The upper limits on the ratio are in the range 0.9-5.4% for $X_b$ masses between 10 and 11 GeV. These are the first upper limits on the production of a possible $X_b$ at a hadron collider.

  11. Depth of initial ideals of normal edge rings

    CERN Document Server

    Hibi, Takayuki; Kimura, Kyouko; O'Keefe, Augustine B

    2011-01-01

    Let $G$ be a finite graph on the vertex set $[d] = \\{1, ..., d \\}$ with the edges $e_1, ..., e_n$ and $K[\\tb] = K[t_1, ..., t_d]$ the polynomial ring in $d$ variables over a field $K$. The edge ring of $G$ is the semigroup ring $K[G]$ which is generated by those monomials $\\tb^e = t_it_j$ such that $e = \\{i, j\\}$ is an edge of $G$. Let $K[\\xb] = K[x_1, ..., x_n]$ be the polynomial ring in $n$ variables over $K$ and define the surjective homomorphism $\\pi : K[\\xb] \\to K[G]$ by setting $\\pi(x_i) = \\tb^{e_i}$ for $i = 1, ..., n$. The toric ideal $I_G$ of $G$ is the kernel of $\\pi$. It will be proved that, given integers $f$ and $d$ with $6 \\leq f \\leq d$, there exist a finite connected nonbipartite graph $G$ on $[d]$ together with a reverse lexicographic order $<_{\\rev}$ on $K[\\xb]$ and a lexicographic order $<_{\\lex}$ on $K[\\xb]$ such that (i) $K[G]$ is normal, (ii) $\\depth K[\\xb]/\\ini_{<_{\\rev}}(I_G) = f$ and (iii) $K[\\xb]/\\ini_{<_{\\lex}}(I_G)$ is Cohen--Macaulay, where $\\ini_{<_{\\rev}}(I_G)$ (r...

  12. Discovery of Extremely Embedded X-ray Sources in the R Coronae Australis Star Forming Core

    CERN Document Server

    Hamaguchi, K; Petre, R; White, N E; Stelzer, B; Nedachi, K; Kobayashi, N; Tokunaga, A T; Hamaguchi, Kenji; Corcoran, Michael F.; Petre, Rob; White, Nicholas E.; Stelzer, Beate; Nedachi, Ko; Kobayashi, Naoto; Tokunaga, Alan T.

    2005-01-01

    With the XMM-Newton and Chandra observatories, we detected two extremely embedded X-ray sources in the R Corona Australis (R CrA) star forming core, near IRS 7. These sources, designated as XB and XA, have X-ray absorption columns of ~3e23 cm-2 equivalent to AV ~180 mag. They are associated with the VLA centimeter radio sources 10E and 10W, respectively. XA is the counterpart of the near-infrared source IRS 7, whereas XB has no K-band counterpart above 19.4 mag. This indicates that XB is younger than typical Class I protostars, probably a Class 0 protostar or in an intermediate phase between Class 0 and Class I. The X-ray luminosity of XB varied between 29XB also showed a monotonic increase in X-ray brightness by a factor of two in 30 ksec during an XMM-Newton observation. The XMM-Newton spectra indicate emission from a hot plasma with kT ~3-4 keV and also show fluorescent emission from cold iron. Though the X-ray spectrum from XB is similar to flare ...

  13. Cooperative or Anticooperative: How Noncovalent Interactions Influence Each Other.

    Science.gov (United States)

    Saha, Soumen; Sastry, G Narahari

    2015-08-27

    This computational study examines the key factors that control the structures and energetics of the coexistence of multiple noncovalent interactions. 4-Amino-2-iodophenol is taken as a model that exhibits nine different kinds of noncovalent interactions, viz., cation-π (CP), hydrogen bond (HB) through O (OHB), HB through N (NHB), halogen bond (XB), π-π (PP), metal ion-lone pair (ML) through O (OML), ML through N (NML), charge assisted hydrogen bond (CHB) through O (OCHB), and CHB through N (NCHB). Through all possible combinations of these noncovalent interactions, based on energy, geometry, charge, and atoms in molecules (AIM) analysis, we have systematically analyzed the cooperativity among 40 ternary systems and 105 quaternary systems. We have observed that CP-HB, CP-XB, CP-PP, HB-HB, HB-XB, HB-PP, HB-ML, HB-CHB, XB-PP, XB-ML, XB-CHB, PP-ML, and PP-OCHB can form cooperative ternary systems. While studying the quaternary systems, we have observed that HB, XB, and PP work together by enhancing each other's strength. The study highlights that the positively charged species enhances HB-HB and HB-PP interactions and forms cooperative HB-HB-CHB, HB-HB-ML, HB-PP-ML, and HB-PP-CHB systems. Surprisingly, OHB-OML-NML, OHB-OML-OCHB, OHB-OML-NCHB, OHB-NML-OCHB, NHB-OML-NML, NHB-OML-NCHB, and NHB-NML-OCHB are also cooperative in nature despite the electrostatic repulsion between two positive charge species. The current study shows the widespread presence of cooperativity as well as anticooperativity in supramolecular assembles.

  14. RXTE Observations of 1A 1744-361: Correlated Spectral and Timing Behavior

    CERN Document Server

    Bhattacharya, S; Swank, J H; Markwardt, C B; Bhattacharyya, Sudip; Strohmayer, Tod E.; Swank, Jean H.; Markwardt, Craig B.

    2006-01-01

    We analyze Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) data of the transient low mass X-ray binary (LMXB) system 1A 1744-361. We explore the X-ray intensity and spectral evolution of the source, perform timing analysis, and find that 1A 1744-361 shows `atoll' behavior during the outbursts. The color-color diagram indicates that this LMXB was observed in a low intensity spectrally hard (low-hard) state and in a high intensity `banana' state. The low-hard state shows a horizontal pattern in the color-color diagram, and the previously reported `dipper QPO' appears only during this state. We also perform energy spectral analyses, and report the first detection of broad iron emission line and iron absorption edge from 1A 1744-361.

  15. A Radio Pulsar/X-ray Binary Link

    CERN Document Server

    Archibald, Anne M; Ransom, Scott M; Kaspi, Victoria M; Kondratiev, Vladislav I; Lorimer, Duncan R; McLaughlin, Maura A; Boyles, Jason; Hessels, Jason W T; Lynch, Ryan; van Leeuwen, Joeri; Roberts, Mallory S E; Jenet, Frederick; Champion, David J; Rosen, Rachel; Barlow, Brad N; Dunlap, Bart H; Remillard, Ronald A

    2009-01-01

    Radio pulsars with millisecond spin periods are thought to have been spun up by transfer of matter and angular momentum from a low-mass companion star during an X-ray-emitting phase. The spin periods of the neutron stars in several such low-mass X-ray binary (LMXB) systems have been shown to be in the millisecond regime, but no radio pulsations have been detected. Here we report on detection and follow-up observations of a nearby radio millisecond pulsar (MSP) in a circular binary orbit with an optically identified companion star. Optical observations indicate that an accretion disk was present in this system within the last decade. Our optical data show no evidence that one exists today, suggesting that the radio MSP has turned on after a recent LMXB phase.

  16. The mechanism of bursting phenomena in Belousov-Zhabotinsky(BZ) chemical reaction with multiple time scales

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The dynamics of a typical Belousov-Zhabotinsky(BZ)reaction with multiple time scales is investigated in this paper.Different forms of periodic bursting phenomena,and specially,three types of chaotic bursters with different structures can be obtained,which are in common with the behaviors observed in experiments.The bifurcations connecting the quiescent state and the repetitive spikes are presented to account for the occurrence of the NKoscillations as well as the different forms of chaotic bursters.The mechanism of the period-adding bifurcation sequences is explored to reveal why the length of the periods in the sequences does not change continuously with the continuous variation of the parameters.

  17. Xylobiose, an Alternative Sweetener, Ameliorates Diabetes-Related Metabolic Changes by Regulating Hepatic Lipogenesis and miR-122a/33a in db/db Mice

    Science.gov (United States)

    Lim, Eunjin; Lim, Ji Ye; Kim, Eunju; Kim, Yoo-Sun; Shin, Jae-Ho; Seok, Pu Reum; Jung, Sangwon; Yoo, Sang-Ho; Kim, Yuri

    2016-01-01

    Type 2 diabetes is a major public health concern worldwide. Xylobiose (XB) consists of two molecules of d-xylose and is a major disaccharide in xylooligosaccharides that are used as prebiotics. We hypothesized that XB could regulate diabetes-related metabolic and genetic changes via microRNA expression in db/db mice. For six weeks, C57BL/KsJ-db/db mice received 5% XB as part of the total sucrose content of their diet. XB supplementation improved glucose tolerance with reduced levels of OGTT AUC, fasting blood glucose, HbA1c, insulin, and HOMA-IR. Furthermore, XB supplementation decreased the levels of total triglycerides, total cholesterol, and LDL-C. The expression levels of miR-122a and miR-33a were higher and lower in the XB group, respectively. In the liver, expressions of the lipogenic genes, including, fatty acid synthase (FAS), peroxisome proliferator activated receptor γ (PPARγ), sterol regulatory element-binding protein-1C (SREBP-1C), sterol regulatory element-binding protein-2 (SREBP-2), acetyl-CoA carboxylase (ACC), HMG-CoA reductase (HMGCR), ATP-binding cassette transporter G5/G8 (ABCG5/8), cholesterol 7 alpha-hydroxylase (CYP7A1), and sterol 12-alpha-hydroxylase (CYP8B1), as well as oxidative stress markers, including superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), glutathione peroxidase (GPX), and catalase, were also regulated by XB supplementation. XB supplementation inhibited the mRNA expressions levels of the pro-inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1, as well as phosphorylation of c-Jun N-terminal kinase/stress activated protein kinase (JNK/SAPK), p38 mitogen-activated protein kinases (MAPK), and extracellular signal-regulated kinases 1/2 (ERK1/2). These data demonstrate that XB exhibits anti-diabetic, hypolipogenic, and anti-inflammatory effects via regulation of the miR-122a/33a axis in db/db mice. PMID:27929393

  18. Xylobiose, an Alternative Sweetener, Ameliorates Diabetes-Related Metabolic Changes by Regulating Hepatic Lipogenesis and miR-122a/33a in db/db Mice

    Directory of Open Access Journals (Sweden)

    Eunjin Lim

    2016-12-01

    Full Text Available Type 2 diabetes is a major public health concern worldwide. Xylobiose (XB consists of two molecules of d-xylose and is a major disaccharide in xylooligosaccharides that are used as prebiotics. We hypothesized that XB could regulate diabetes-related metabolic and genetic changes via microRNA expression in db/db mice. For six weeks, C57BL/KsJ-db/db mice received 5% XB as part of the total sucrose content of their diet. XB supplementation improved glucose tolerance with reduced levels of OGTT AUC, fasting blood glucose, HbA1c, insulin, and HOMA-IR. Furthermore, XB supplementation decreased the levels of total triglycerides, total cholesterol, and LDL-C. The expression levels of miR-122a and miR-33a were higher and lower in the XB group, respectively. In the liver, expressions of the lipogenic genes, including, fatty acid synthase (FAS, peroxisome proliferator activated receptor γ (PPARγ, sterol regulatory element-binding protein-1C (SREBP-1C, sterol regulatory element-binding protein-2 (SREBP-2, acetyl-CoA carboxylase (ACC, HMG-CoA reductase (HMGCR, ATP-binding cassette transporter G5/G8 (ABCG5/8, cholesterol 7 alpha-hydroxylase (CYP7A1, and sterol 12-alpha-hydroxylase (CYP8B1, as well as oxidative stress markers, including superoxide dismutase 1 (SOD1, superoxide dismutase 2 (SOD2, glutathione peroxidase (GPX, and catalase, were also regulated by XB supplementation. XB supplementation inhibited the mRNA expressions levels of the pro-inflammatory cytokines, tumor necrosis factor (TNF-α, interleukin (IL-1β, interleukin (IL-6, and monocyte chemoattractant protein (MCP-1, as well as phosphorylation of c-Jun N-terminal kinase/stress activated protein kinase (JNK/SAPK, p38 mitogen-activated protein kinases (MAPK, and extracellular signal-regulated kinases 1/2 (ERK1/2. These data demonstrate that XB exhibits anti-diabetic, hypolipogenic, and anti-inflammatory effects via regulation of the miR-122a/33a axis in db/db mice.

  19. Evaluation of an analytic linear Boltzmann transport equation solver for high-density inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, S. A. M.; Ansbacher, W. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada) and Department of Medical Physics, British Columbia Cancer Agency-Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

    2013-01-15

    Purpose: Acuros external beam (Acuros XB) is a novel dose calculation algorithm implemented through the ECLIPSE treatment planning system. The algorithm finds a deterministic solution to the linear Boltzmann transport equation, the same equation commonly solved stochastically by Monte Carlo methods. This work is an evaluation of Acuros XB, by comparison with Monte Carlo, for dose calculation applications involving high-density materials. Existing non-Monte Carlo clinical dose calculation algorithms, such as the analytic anisotropic algorithm (AAA), do not accurately model dose perturbations due to increased electron scatter within high-density volumes. Methods: Acuros XB, AAA, and EGSnrc based Monte Carlo are used to calculate dose distributions from 18 MV and 6 MV photon beams delivered to a cubic water phantom containing a rectangular high density (4.0-8.0 g/cm{sup 3}) volume at its center. The algorithms are also used to recalculate a clinical prostate treatment plan involving a unilateral hip prosthesis, originally evaluated using AAA. These results are compared graphically and numerically using gamma-index analysis. Radio-chromic film measurements are presented to augment Monte Carlo and Acuros XB dose perturbation data. Results: Using a 2% and 1 mm gamma-analysis, between 91.3% and 96.8% of Acuros XB dose voxels containing greater than 50% the normalized dose were in agreement with Monte Carlo data for virtual phantoms involving 18 MV and 6 MV photons, stainless steel and titanium alloy implants and for on-axis and oblique field delivery. A similar gamma-analysis of AAA against Monte Carlo data showed between 80.8% and 87.3% agreement. Comparing Acuros XB and AAA evaluations of a clinical prostate patient plan involving a unilateral hip prosthesis, Acuros XB showed good overall agreement with Monte Carlo while AAA underestimated dose on the upstream medial surface of the prosthesis due to electron scatter from the high-density material. Film measurements

  20. A Search for Astrophysical Burst Signals at the Sudbury Neutrino Observatory

    CERN Document Server

    Aharmim, B; Anthony, A E; Barros, N; Beier, E W; Bellerive, A; Beltran, B; Bergevin, M; Biller, S D; Boudjemline, K; Boulay, M G; Cai, B; Chan, Y D; Chauhan, D; Chen, M; Cleveland, B T; Cox, G A; Dai, X; Deng, H; Detwiler, J A; DiMarco, M; Diamond, M D; Doe, P J; Doucas, G; Drouin, P -L; Duncan, F A; Dunford, M; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Ford, R J; Formaggio, J A; Gagnon, N; Goon, J TM; Graham, K; Guillian, E; Habib, S; Hahn, R L; Hallin, A L; Hallman, E D; Harvey, P J; Hazama, R; Heintzelman, W J; Heise, J; Helmer, R L; Hime, A; Howard, C; Huang, M; Jagam, P; Jamieson, B; Jelley, N A; Jerkins, M; Keeter, K J; Klein, J R; Kormos, L L; Kos, M; Kraus, C; Krauss, C B; Krueger, A; Kutter, T; Kyba, C C M; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Levine, I; Loach, J C; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Martin, R; McCauley, N; McDonald, A B; McGee, S R; Miller, M L; Monreal, B; Monroe, J; Nickel, B G; Noble, A J; O'Keeffe, H M; Oblath, N S; Ollerhead, R W; Gann, G D Orebi; Oser, S M; Ott, R A; Peeters, S J M; Poon, A W P; Prior, G; Reitzner, S D; Rielage, K; Robertson, B C; Robertson, R G H; Schwendener, M H; Secrest, J A; Seibert, S R; Simard, O; Simpson, J J; Sinclair, D; Skensved, P; Sonley, T J; Stonehill, L C; Tesic, G; Tolich, N; Tsui, T; Van Berg, R; VanDevender, B A; Virtue, C J; Wall, B L; Waller, D; Tseung, H Wan Chan; Wark, D L; Watson, P J S; Wendland, J; West, N; Wilkerson, J F; Wilson, J R; Wouters, J M; Wright, A; Yeh, M; Zhang, F; Zuber, K

    2013-01-01

    The Sudbury Neutrino Observatory (SNO) has confirmed the standard solar model and neutrino oscillations through the observation of neutrinos from the solar core. In this paper we present a search for neutrinos associated with sources other than the solar core, such as gamma-ray bursters and solar flares. We present a new method for looking for temporal coincidences between neutrino events and astrophysical bursts of widely varying intensity. No correlations were found between neutrinos detected in SNO and such astrophysical sources.

  1. Recent results from the Japanese X-ray astronomy satellites

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Y.

    1986-01-01

    Observations of neutron stars and their environments, and the emission and absorption of iron, obtained with the Hakucho and Tenma satellites, are examined. The characteristics of X-ray bursts, neutron stars, and accretion disks, in particular spectra, color and effective temperatures, blackbody temperature and radius, the emissivity factor, and the Eddington limit luminosity, are discussed. Consideration is given to the rapid burster discovered by Lewin et al. (1976) and potential blackhole sources. 43 references.

  2. Inelastic Branch of the Stellar Reaction $^{14}$O$(\\alpha,p)^{17}$F

    CERN Multimedia

    Hass, M; Van duppen, P L E

    2002-01-01

    We propose to use the upgraded REX-ISOLDE beam energy to study the astrophysically important $^{14}$O($\\alpha$, p)$^{17}$F reaction in time reverse kinematics. In particular, we will use the highly efficient miniball + CD detection system to measure the previously undetermined inelastic proton branch of the 1$^-$ state at 6.15 MeV in $^{18}$Ne. This state dominates the reaction rate under X-ray burster conditions.

  3. Deep Chandra X-ray Observations of Low Mass X-ray Binary Candidates in the Early-Type Galaxy NGC 4697

    CERN Document Server

    Sivakoff, Gregory R; Juett, Adrienne M; Sarazin, Craig L; Irwin, Jimmy A

    2008-01-01

    Chandra X-ray observations routinely resolve tens to hundreds of low-mass X-ray binaries (LMXBs) per galaxy in nearby massive early-type galaxies. These studies have raised important issues regarding the behavior of this population of remnants of the once massive stars in early-type galaxies, namely the connection between LMXBs and globular clusters (GCs) and the nature of the LMXB luminosity function (LF). In this paper, we combine five epochs of Chandra observations and one central field Hubble Space Telescope Advance Camera for Surveys observation of NGC 4697, one of the nearest, optically luminous elliptical (E6) galaxies, to probe the GC-LMXB connection and LMXB-LF down to a detection/completeness limit of (0.6/1.4) x 10^{37} ergs/s. We detect 158 sources, present their luminosities and hardness ratios, and associate 34 LMXBs with GCs. We confirm that GCs with higher encounter rates (\\Gamma_h) and redder colors (higher metallicity Z) are more likely to contain GCs, and find that the expected number of LM...

  4. Population synthesis of classical low-mass X-ray binaries in the Galactic Bulge

    CERN Document Server

    van Haaften, L M; Voss, R; van der Sluys, M V; Toonen, S

    2015-01-01

    Aims. We model the present-day population of 'classical' low-mass X-ray binaries (LMXBs) with neutron star accretors, which have hydrogen-rich donor stars. Their population is compared with that of hydrogen-deficient LMXBs, known as ultracompact X-ray binaries (UCXBs). We model the observable LMXB population and compare it to observations. Methods. We combine the binary population synthesis code SeBa with detailed LMXB evolutionary tracks to model the size and properties of the present-day LMXB population in the Galactic Bulge. Whether sources are persistent or transient, and what their instantaneous X-ray luminosities are, is predicted using the thermal-viscous disk instability model. Results. We find a population of ~2.1 x 10^3 LMXBs with neutron star accretors. Of these about 15 - 40 are expected to be persistent (depending on model assumptions), with luminosities higher than 10^35 erg s^-1. About 7 - 20 transient sources are expected to be in outburst at any given time. Within a factor of two these number...

  5. The X-ray Luminosity Functions of Field Low Mass X-ray Binaries in Early-Type Galaxies: Evidence for a Stellar Age Dependence

    CERN Document Server

    Lehmer, B D; Zezas, A; Alexander, D M; Basu-Zych, A; Bauer, F E; Brandt, W N; Fragos, T; Hornschemeier, A E; Kalogera, V; Ptak, A; Sivakoff, G R; Tzanavaris, P; Yukita, M

    2014-01-01

    We present direct constraints on how the formation of low-mass X-ray binary (LMXB) populations in galactic fields depends on stellar age. In this pilot study, we utilize Chandra and Hubble Space Telescope (HST) data to detect and characterize the X-ray point source populations of three nearby early-type galaxies: NGC 3115, 3379, and 3384. The luminosity-weighted stellar ages of our sample span 3-10 Gyr. X-ray binary population synthesis models predict that the field LMXBs associated with younger stellar populations should be more numerous and luminous per unit stellar mass than older populations due to the evolution of LMXB donor star masses. Crucially, the combination of deep Chandra and HST observations allows us to test directly this prediction by identifying and removing counterparts to X-ray point sources that are unrelated to the field LMXB populations, including LMXBs that are formed dynamically in globular clusters, Galactic stars, and background AGN/galaxies. We find that the "young" early-type galax...

  6. Measurement of Two- and Three-Nucleon Short-Range Correlation Probabilities in Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    K. S. Egiyan; N. B. Dashyan; M. M. Sargsian; M. I. Strikman; L. B. Weinstein; G. Adams; P. Ambrozewicz; M. Anghinolfi; B. Asavapibhop; G. Asryan; H. Avakian; H. Baghdasaryan; N. Baillie; J. P. Ball; N. A. Baltzell; V. Batourine; M. Battaglieri; I. Bedlinskiy; M. Bektasoglu; M. Bellis; N. Benmouna; A. S. Biselli; B. E. Bonner; S. Bouchigny; S. Boiarinov; R. Bradford; D. Branford; W. K. Brooks; S. Bültmann; V. D. Burkert; C. Bultuceanu; J. R. Calarco; S. L. Careccia; D. S. Carman; B. Carnahan; S. Chen; P. L. Cole; P. Coltharp; P. Corvisiero; D. Crabb; H. Crannell; J. P. Cummings; E. De Sanctis; R. DeVita; P. V. Degtyarenko; H. Denizli; L. Dennis; K. V. Dharmawardane; C. Djalali; G. E. Dodge; J. Donnelly; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; O. P. Dzyubak; H. Egiyan; L. Elouadrhiri; A. Empl; P. Eugenio; R. Fatemi; G. Fedotov; R. J. Feuerbach; T. A. Forest; H. Funsten; G. Gavalian; N. G. Gevorgyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; E. Golovatch; R. W. Gothe; K. A. Griffioen; M. Guidal; M. Guillo; N. Guler; L. Guo; V. Gyurjyan; C. Hadjidakis; J. Hardie; F. W. Hersman; K. Hicks; I. Hleiqawi; M. Holtrop; J. Hu; M. Huertas; C. E. Hyde-Wright; Y. Ilieva; D. G. Ireland; B. S. Ishkhanov; M. M. Ito; D. Jenkins; H. S. Jo; K. Joo; H. G. Juengst; J. D. Kellie; M. Khandaker; K. Y. Kim; K. Kim; W. Kim; A. Klein; F. J. Klein; A. Klimenko; M. Klusman; L. H. Kramer; V. Kubarovsky; J. Kuhn; S. E. Kuhn; S. Kuleshov; J. Lachniet; J. M. Laget; J. Langheinrich; D. Lawrence; T. Lee; K. Livingston; L. C. Maximon; S. McAleer; B. McKinnon; J. W. C. McNabb; B. A. Mecking; M. D. Mestayer; C. A. Meyer; T. Mibe; K. Mikhailov; R. Minehart; M. Mirazita; R. Miskimen; V. Mokeev; S. A. Morrow; J. Mueller; G. S. Mutchler; P. Nadel-Turonski; J. Napolitano; R. Nasseripour; S. Niccolai; G. Niculescu; I. Niculescu; B. B. Niczyporuk; R. A. Niyazov; G. V. O' Rielly; M. Osipenko; A. I. Ostrovidov; K. Park; E. Pasyuk; C. Peterson; J. Pierce; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; S. Pozdniakov; B. M. Preedom; J. W. Price; Y. Prok; D. Protopopescu; L. M. Qin; B. A. Raue; G. Riccardi; G. Ricco; M. Ripani; B. G. Ritchie; F. Ronchetti; G. Rosner; P. Rossi; D. Rowntree; P. D. Rubin; F. Sabatié; C. Salgado; J. P. Santoro; V. Sapunenko; R. A. Schumacher; V. S. Serov; Y. G. Sharabian; J. Shaw; E. S. Smith; L. C. Smith; D. I. Sober; A. Stavinsky; S. Stepanyan; B. E. Stokes; P. Stoler; S. Strauch; R. Suleiman; M. Taiuti; S. Taylor; D. J. Tedeschi; R. Thompson; A. Tkabladze; S. Tkachenko; L. Todor; C. Tur; M. Ungaro; M. F. Vineyard; A. V. Vlassov; D. P. Weygand; M. Williams; E. Wolin; M. H. Wood; A. Yegneswaran; J. Yun; L. Zana; and J. Zhang

    2006-03-01

    The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1<xB<3. At Q2>1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5<xB<2 and at xB>2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A=3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A=4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.

  7. A Kunitz proteinase inhibitor from corms of Xanthosoma blandum with bactericidal activity.

    Science.gov (United States)

    Lima, Thaís B; Silva, Osmar N; Migliolo, Ludovico; Souza-Filho, Carlos R; Gonçalves, Eduardo G; Vasconcelos, Ilka M; Oliveira, José T A; Amaral, André C; Franco, Octávio L

    2011-05-27

    Bacterial infections directly affect the world's population, and this situation has been aggravated by indiscriminate use of antimicrobial agents, which can generate resistant microorganisms. In this report, an initial screening of proteins with antibacterial activity from corms of 15 species of the Xanthosoma genus was conducted. Since Xanthosoma blandum corms showed enhanced activity toward bacteria, a novel protein with bactericidal activity was isolated from this particular species. Edman degradation was used for protein N-termini determination; the primary structure showed similarities with Kunitz inhibitors, and this protein was named Xb-KTI. This protein was further challenged against serine proteinases from different sources, showing clear inhibitory activities. Otherwise, no hemolytic activity was observed for Xb-KTI. The results demonstrate the biotechnological potential of Xb-KTI, the first proteinase inhibitor with antimicrobial activity described in the Xanthosoma genus.

  8. On the absence of plasma wave emissions and the magnetic field orientation in the distant magnetosheath

    Energy Technology Data Exchange (ETDEWEB)

    Coroniti, F.V.; Greenstadt, E.W.; Moses, S.L. [TRW Space and Electronics Group, Redondo Beach, CA (United States); Tsurutani, B.T.; Smith, E.J. [California Institute of Technology, Pasadena, CA (United States)

    1994-12-01

    In early September, 1983 ISEE-3 made a long traversal of the distant dawnside magnetosheath starting near x = {minus}150 R{sub E} downstream. The distant magnetosheath often contains moderately intense plasma wave emissions at frequencies from several hundred Hz to 5 kHz. However, over time scales of many days, a clear correlation exists between the occurrence of the plasma waves and the cone angle ({theta}{sub xB}) between the magnetic field and the plasma flow velocity (x-direction). For {theta}{sub xB} large (small), the plasma wave amplitudes are near background (high). Sudden (<1 minute) changes in the local magnetic field orientation produce correspondingly sudden changes in the wave amplitudes. Statistically, the wave amplitudes decrease continuously with increasing {theta}{sub xB}. 7 refs., 5 figs.

  9. Mathematical Analysis of Actuator Forces in a Scissor Lift

    Science.gov (United States)

    1994-05-01

    12 = (xB x.4) 2 + (.B -..- ) 2 = [ (XBo-X.40 ) cosO + (xB90 - X49o) sinO] 2 + I (.BQO - ’.49o) sin0 + (YBo -- YAo) cosO] 2 ( acosO - bsinO) 2...csinO + dcoso) 2 (EQ 3) where Ui = XBO- Y = YB90--YAQ.90 b = xB90 - X4 9 0 d YBo-YAO • Taking the derivative of / with respect to h gives 21d [2 ( acosO ...bsinO) (-asinO + bcosO) + 2 (csinO + dcosO) (ccosO - dsinO) I LO h dh’ and solving for Lhresults in dI 2 1dh dl 2 ( acosO + bsinO) (-asinO ý- bcos0

  10. New Insights into the EMC Effect

    Energy Technology Data Exchange (ETDEWEB)

    Douglas Higinbotham

    2012-08-17

    Deep-inelastic scattering cross section ratios plotted as a function of the Bjorken scaling variable, xB, show an unexpected structure indicating that partonic structure in nuclei is different than in free nucleons. This phenomenon is commonly referred to as the EMC effect. Recent Jefferson Lab experimental data showed that the slope of the EMC effect in the 0.3 < xB > 0.7 region scales as the local nuclear density rather than the average nuclear density. This result lead to the comparison of xB>1 short-range correlation plateaus, also a local density effect, to the magnitude of the EMC effect slopes and a clear linear relation was found. In this talk, I will discuss the EMC effect and the short-range correlation plateaus and what this phenomenological relationship between the two implies.

  11. A live attenuated BCG vaccine overexpressing multistage antigens Ag85B and HspX provides superior protection against Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Yuan, Xuefeng; Teng, Xindong; Jing, Yukai; Ma, Jilei; Tian, Maopeng; Yu, Qi; Zhou, Lei; Wang, Ruibo; Wang, Weihua; Li, Li; Fan, Xionglin

    2015-12-01

    Tuberculosis (TB) remains one of the most menacing infectious diseases, although attenuated Mycobacterium bovis Bacillus Calmette-Guerin (BCG) vaccine has been widely used to protect children against primary TB. There are increasing evidences that rapid growing and dormant Mycobacterium tuberculosis (M. tuberculosis) coexist in vivo after infection. However, BCG vaccine only elicits cell-mediated immune responses to secretory antigens expressed by rapid growing pathogen. BCG vaccine is thus unable to thwart the reactivation of latent tuberculosis infection (LTBI), and its protection wanes over age after neonatal immunization. In order to extend its ability for a durable protection, a novel recombinant BCG (rBCG) strain, named rBCG::XB, was constructed by overexpressing immunodominant multistage antigens of Ag85B and HspX, which are expressed by both rapid replicating and dormant M. tuberculosis. Long-term protective effect and immunogenicity of rBCG::XB were compared with the parental BCG in vaccinated C57BL/6 mice. Our results demonstrated that rBCG::XB provided the stronger and long-lasting protection against M. tuberculosis H37Rv intranasal infection than BCG. The rBCG::XB not only elicited the more durable multistage antigen-specific CD4(+)Th1-biased immune responses and specific polyfunctional CD4(+)T cells but also augmented the CD8(+) CTL effects against Ag85B in vivo. In particular, higher levels of CD4(+) TEM and CD8(+) TCM cells, dominated by IL2(+) CD4(+) and CD8(+) TCM cells, were obtained in the spleen of rBCG::XB vaccinated mice. Therefore, our findings indicate that rBCG::XB is a promising candidate to improve the efficacy of BCG.

  12. Research on the Physicochemical Property of the Starch in Different Cassava Varieties%不同品种的木薯淀粉理化特性研究

    Institute of Scientific and Technical Information of China (English)

    杨栋林; 陈燕珍; 庞月圆; 刘晓灿; 谭涛

    2009-01-01

    [Objective] The physical and chemical characteristics of cassava starch was studied.[Method] The cassava variety: bread cassava with large leaf and white skin(DB), bread cassava with small leaf and white skin (XB), bread cassava with large leaf and red skin(DH) being taken as experimental material, the physical and chemical property such as the content of protein, the light transmittance, the stability of frozen and condensation/precipitation, and cassava shape of these varieties was tested.[Results] The order of the content of protein from high to low was: XB>DH>DB;the light transmittance, DB>XB>DH;there was no difference in the stability of frozen and condensation/precipitation among varieties;and there was difference in the cassava shape among varieties.[Conclusion] The scientific reference for the deep processing and development and utilization of cassava was provided.%[目的]研究木薯淀粉的理化特性.[方法]以大叶白皮面包木薯(DB)、小叶白皮面包木薯(XB)、大叶红皮面包木薯(DH)为试验材料,测定其蛋白质含量、透光率、冷冻稳定性、凝沉稳定性及颗粒形态等理化特性.[结果]蛋白质含量的高低为:XB>DH>DB;透光率的大小为:DB>XB>DH;冷冻稳定性及凝沉稳定性差异不大;淀粉的颗粒形态有差异.[结论]试验为木薯的深加工及开发利用提供了科学的参考依据.

  13. The thermal evolution indicator of carbonate rocks

    Institute of Scientific and Technical Information of China (English)

    王兆云; 范璞; 程克明

    1995-01-01

    It has been studied by the solid state 13C NMR analysis that the chemical composition and the structure feature of kerogen of carbonate rocks are characteristic of different types and evolution degree. The purpose is to show the evolution degree using the structure parameters of kerogen of carbonate rocks. The detailed analysis of the carbon aromaticity (fa), the hydrogen aromaticity (Ha) and the average aromatic cluster size (Xb) indicates that Xb is the most effective indicator of evolution degree, and it is not influenced by the type and evolution degree of kerogen. The correlation between the average aromatic cluster size and vitrinite reflectance value of kerogen has also been established.

  14. Techniques for determining propulsion system forces for accurate high speed vehicle drag measurements in flight

    Science.gov (United States)

    Arnaiz, H. H.

    1975-01-01

    As part of a NASA program to evaluate current methods of predicting the performance of large, supersonic airplanes, the drag of the XB-70 airplane was measured accurately in flight at Mach numbers from 0.75 to 2.5. This paper describes the techniques used to determine engine net thrust and the drag forces charged to the propulsion system that were required for the in-flight drag measurements. The accuracy of the measurements and the application of the measurement techniques to aircraft with different propulsion systems are discussed. Examples of results obtained for the XB-70 airplane are presented.

  15. Drug: D00984 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available LISM A01 STOMATOLOGICAL PREPARATIONS A01A STOMATOLOGICAL PREPARATIONS A01AC Corticosteroids for local oral t...ASCULAR SYSTEM C05 VASOPROTECTIVES C05A AGENTS FOR TREATMENT OF HEMORRHOIDS AND ANAL FISSURES FOR TOPICAL USE C05AA Corticosteroids... CORTICOSTEROIDS, DERMATOLOGICAL PREPARATIONS D07A CORTICOSTEROIDS, PLAIN D07AB Corticosteroids...D07X CORTICOSTEROIDS, OTHER COMBINATIONS D07XB Corticosteroids, moderately potent, other combinations D07XB0...RATORY SYSTEM R01 NASAL PREPARATIONS R01A DECONGESTANTS AND OTHER NASAL PREPARATIONS FOR TOPICAL USE R01AD Corticosteroids

  16. Drug: D01615 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ISM A01 STOMATOLOGICAL PREPARATIONS A01A STOMATOLOGICAL PREPARATIONS A01AC Corticosteroids...AR SYSTEM C05 VASOPROTECTIVES C05A AGENTS FOR TREATMENT OF HEMORRHOIDS AND ANAL FISSURES FOR TOPICAL USE C05AA Corticosteroids...TEROIDS, DERMATOLOGICAL PREPARATIONS D07A CORTICOSTEROIDS, PLAIN D07AB Corticosteroids...TEROIDS, OTHER COMBINATIONS D07XB Corticosteroids, moderately potent, other combinations D07XB05 Dexamethaso... PREPARATIONS FOR TOPICAL USE D10AA Corticosteroids, combinations for treatment of acne D10AA03 Dexamethason

  17. Drug: D01510 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available CAL PREPARATIONS A01AC Corticosteroids for local oral treatment A01AC02 Dexamethasone D01510 Dexamethasone m...ENTS FOR TREATMENT OF HEMORRHOIDS AND ANAL FISSURES FOR TOPICAL USE C05AA Corticosteroids C05AA09 Dexamethas...L PREPARATIONS D07A CORTICOSTEROIDS, PLAIN D07AB Corticosteroids, moderately pote..., OTHER COMBINATIONS D07XB Corticosteroids, moderately potent, other combinations D07XB05 Dexamethasone D015...NTI-ACNE PREPARATIONS FOR TOPICAL USE D10AA Corticosteroids, combinations for treatment of acne D10AA03 Dexa

  18. Drug: D01948 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available TRACT AND METABOLISM A01 STOMATOLOGICAL PREPARATIONS A01A STOMATOLOGICAL PREPARATIONS A01AC Corticosteroid... TOPICAL USE C05AA Corticosteroids C05AA09 Dexamethasone D01948 Dexamethasone valerate (JAN) D DERMATOLOGICA...LS D07 CORTICOSTEROIDS, DERMATOLOGICAL PREPARATIONS D07A CORTICOSTEROIDS, PLAIN D07AB Corticosteroids... D07X CORTICOSTEROIDS, OTHER COMBINATIONS D07XB Corticosteroids, moderately potent, other combinations D07XB...10A ANTI-ACNE PREPARATIONS FOR TOPICAL USE D10AA Corticosteroids, combinations for treatment of acne D10AA03

  19. 77 FR 21752 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-04-11

    ... Administration (NOAA), Commerce. ACTION: Notice of a public meeting. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN 0648-XB153 New England Fishery Management Council...: (860) 572-0328. Council address: New England Fishery Management Council, 50 Water Street, Mill...

  20. 77 FR 20613 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-04-05

    ... National Oceanic and Atmospheric Administration RIN 0648-XB129 New England Fishery Management Council... Administration (NOAA), Commerce. ACTION: Notice of cancellation of a public meeting. SUMMARY: The New England Fishery Management Council (Council) has cancelled the public meeting of its Scientific and...

  1. 77 FR 19228 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-03-30

    ... Administration (NOAA), Commerce. ACTION: Notice; public meeting. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN 0648-XB137 New England Fishery Management Council... 04101; telephone: (207) 775-2311; fax: (207) 772-4017. Council address: New England Fishery...

  2. 77 FR 15721 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-03-16

    ... Administration (NOAA), Commerce. ACTION: Notice; public meeting. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN0648-XB090 New England Fishery Management Council...-4306. Council address: New England Fishery Management Council, 50 Water Street, Mill 2, Newburyport,...

  3. 77 FR 8809 - New England Fishery Management Council; Public Hearings

    Science.gov (United States)

    2012-02-15

    ... Administration (NOAA), Commerce. ACTION: Notice; public hearings. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN 0648-XB006 New England Fishery Management Council... Herring Fishery Management Plan (FMP). DATES: Written public comments must be received on or before 5...

  4. 77 FR 16810 - New England Fishery Management Council; Public Hearings

    Science.gov (United States)

    2012-03-22

    ... National Oceanic and Atmospheric Administration RIN 0648-XB104 New England Fishery Management Council... Administration (NOAA), Commerce. ACTION: Notice of public hearings; request for comments. SUMMARY: The New England Fishery Management Council (Council) will hold five public hearings to solicit Scoping comments...

  5. 77 FR 16540 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-03-21

    ... Administration (NOAA), Commerce ACTION: Notice; public meeting. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN: 0648-XB097 New England Fishery Management Council...-4306. Council address: New England Fishery Management Council, 50 Water Street, Mill 2, Newburyport,...

  6. 77 FR 15720 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-03-16

    ... Administration (NOAA), Commerce. ACTION: Notice; public meeting. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN 0648-XB092 New England Fishery Management Council...-3000; fax: (401) 732-9309. Council address: New England Fishery Management Council, 50 Water...

  7. 77 FR 16211 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-03-20

    ... Administration (NOAA), Commerce. ACTION: Notice; public meeting. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN 0648-XB091 New England Fishery Management Council.... Council address: New England Fishery Management Council, 50 Water Street, Mill 2, Newburyport, MA...

  8. 77 FR 19231 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-03-30

    ... Administration (NOAA), Commerce. ACTION: Notice; public meeting. SUMMARY: The New England Fishery Management... National Oceanic and Atmospheric Administration RIN 0648-XB129 New England Fishery Management Council...: (401) 861-8002. Council address: New England Fishery Management Council, 50 Water Street, Mill...

  9. Dicty_cDB: Contig-U03667-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available re callus 7d ... 46 1.6 1 ( DY490191 ) sh1-xb10_l0.s2 adult sheep fracture callus p...9OML22049076HT OML2 Ovis aries cDNA, mRNA se... 46 1.6 1 ( DY496264 ) sh2P0018H02_F.ab1 adult sheep fractu

  10. 78 FR 2672 - Application for Final Commitment for a Long-Term Loan or Financial Guarantee in Excess of $100...

    Science.gov (United States)

    2013-01-14

    ... From the Federal Register Online via the Government Publishing Office EXPORT-IMPORT BANK OF THE UNITED STATES Application for Final Commitment for a Long-Term Loan or Financial Guarantee in Excess of $100 Million: AP078595XX, AP078595XA, AP078595XB AGENCY: Export-Import Bank of the United...

  11. 77 FR 19563 - 2012 Accountability Measures for Gulf of Mexico Commercial Greater Amberjack and Closure of the...

    Science.gov (United States)

    2012-04-02

    ... National Oceanic and Atmospheric Administration 50 CFR Part 622 RIN 0648-XB074 2012 Accountability Measures... (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS implements accountability measures (AMs... not occur in the fishery, including measures to ensure accountability. On July 3, 2008, NMFS issued...

  12. Diversity, Biocontrol, and Plant Growth Promoting Abilities of Xylem Residing Bacteria from Solanaceous Crops

    Directory of Open Access Journals (Sweden)

    Gauri A. Achari

    2014-01-01

    Full Text Available Eggplant (Solanum melongena L. is one of the solanaceous crops of economic and cultural importance and is widely cultivated in the state of Goa, India. Eggplant cultivation is severely affected by bacterial wilt caused by Ralstonia solanacearum that colonizes the xylem tissue. In this study, 167 bacteria were isolated from the xylem of healthy eggplant, chilli, and Solanum torvum Sw. by vacuum infiltration and maceration. Amplified rDNA restriction analysis (ARDRA grouped these xylem residing bacteria (XRB into 38 haplotypes. Twenty-eight strains inhibited growth of R. solanacearum and produced volatile and diffusible antagonistic compounds and plant growth promoting substances in vitro. Antagonistic strains XB86, XB169, XB177, and XB200 recorded a biocontrol efficacy greater than 85% against BW and exhibited 12%–22 % increase in shoot length in eggplant in the greenhouse screening. 16S rRNA based identification revealed the presence of 23 different bacterial genera. XRB with high biocontrol and plant growth promoting activities were identified as strains of Staphylococcus sp., Bacillus sp., Streptomyces sp., Enterobacter sp., and Agrobacterium sp. This study is the first report on identity of bacteria from the xylem of solanaceous crops having traits useful in cultivation of eggplant.

  13. Muusika tuppa või õue / Harri Slip, Glen Pilvre

    Index Scriptorium Estoniae

    Slip, Harri

    2016-01-01

    Juhtmevabad kõlarid: Bose SoundLink Colour, Creative Roar 2, Denon Envaya Mini, JBL Charge 3, Klipsch Groove, Onkyo T3 Philips BT6600, Pioneer XW-BTSP70, Samsung Level Box Pro, Sony SRS-XB3, Ultimate Ears Boom 2. Etalon: Sony SRS-HG1

  14. Gluon Shadowing in DIS off Nuclei

    CERN Document Server

    Kopeliovich, B Z; Potashnikova, I K; Schmidt, I

    2008-01-01

    Within a light-cone quantum-chromodynamics dipole formalism based on the Green function technique, we study nuclear shadowing in deep-inelastic scattering at small Bjorken xB 0.0001, when a variation of the transverse size of the \\bar{q}q Fock component must be taken into account. The eikonal approximation, used so far in most other models, can be applied only at high energies, when xB < 0.0001 and the transverse size of the \\bar{q}q Fock component is "frozen" during propagation through the nuclear matter. At xB < 0.01 we find quite a large contribution of gluon suppression to nuclear shadowing, as a shadowing correction for the higher Fock states containing gluons. Numerical results for nuclear shadowing are compared with the available data from the E665 and NMC collaborations. Nuclear shadowing is also predicted at very small xB corresponding to LHC kinematical range. Finally the model predictions are compared and discussed with the results obtained from other models.

  15. 78 FR 3402 - Marine Mammals; File No. 16919

    Science.gov (United States)

    2013-01-16

    ... National Oceanic and Atmospheric Administration RIN 0648-XB173 Marine Mammals; File No. 16919 AGENCY... the authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216), the Endangered Species...

  16. 77 FR 33444 - Marine Mammals; File No. 17217

    Science.gov (United States)

    2012-06-06

    ... National Oceanic and Atmospheric Administration RIN 0648-XB159 Marine Mammals; File No. 17217 AGENCY... Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.) and the regulations governing the taking and importing of marine mammals (50 CFR part 216). In compliance with the National...

  17. 78 FR 51146 - Marine Mammals; File No. 14535

    Science.gov (United States)

    2013-08-20

    ... National Oceanic and Atmospheric Administration RIN 0648-XB161 Marine Mammals; File No. 14535 AGENCY... Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.); and the regulations governing the taking and importing of marine mammals (50 CFR part 216). Permit No. 14535-02 authorizes...

  18. 77 FR 31585 - Marine Mammals; File No. 16388

    Science.gov (United States)

    2012-05-29

    ... National Oceanic and Atmospheric Administration RIN 0648-XB154 Marine Mammals; File No. 16388 AGENCY... Mammal Protection Act of 1972, as amended (MMPA; 16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216), the Endangered Species Act of 1973, as...

  19. 77 FR 14352 - Marine Mammals

    Science.gov (United States)

    2012-03-09

    ... National Oceanic and Atmospheric Administration RIN 0648-XB065 Marine Mammals AGENCY: National Marine... permit has been issued under the authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50...

  20. 77 FR 19646 - Marine Mammals; File No. 17178

    Science.gov (United States)

    2012-04-02

    ... National Oceanic and Atmospheric Administration RIN 0648-XB139 Marine Mammals; File No. 17178 AGENCY... permit to import marine mammal parts for scientific research. DATES: Written, telefaxed, or email.... SUPPLEMENTARY INFORMATION: The subject permit is requested under the authority of the Marine Mammal...

  1. 78 FR 25425 - Marine Mammals; File No. 16388

    Science.gov (United States)

    2013-05-01

    ... National Oceanic and Atmospheric Administration RIN 0648-XB154 Marine Mammals; File No. 16388 AGENCY... issued under the authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216), the...

  2. 78 FR 21112 - Marine Mammals; File Nos. 16992 and 14535

    Science.gov (United States)

    2013-04-09

    ..., Ph.D., Hawaii Institute of Marine Biology, University of Hawaii, P.O. Box 1106, Kailua, HI 96734, has... of Marine Biology in Kaneohe, HI. Researchers would conduct hearing measurements using suction cup... National Oceanic and Atmospheric Administration RIN 0648-XB161 Marine Mammals; File Nos. 16992 and...

  3. 78 FR 42935 - Marine Mammals; File No. 16992

    Science.gov (United States)

    2013-07-18

    ... Nachtigall, Ph.D., Hawaii Institute of Marine Biology, University of Hawaii, P.O. Box 1106, Kailua, HI 96734... Marine Biology in Kaneohe, Hawaii. Researchers will conduct hearing measurements using suction cup... National Oceanic and Atmospheric Administration RIN 0648-XB161 Marine Mammals; File No. 16992...

  4. New R-matrix calculations of neutral W electron-impact excitation and ionization for PFC erosion diagnostics

    Science.gov (United States)

    Loch, S. D.; Ennis, D. A.; Pindzola, M. S.; Johnson, C. A.; Ballance, C. P.; Abrams, T.; Unterberg, E.

    2016-10-01

    The erosion rate of tungsten PFCs can be diagnosed spectroscopically using spectral line intensity measurements combined with a set of `ionizations per photon' coefficients (also called S/XB ratios). The accuracy of this diagnostic technique depends critically upon the quality of the atomic data comprising the S/XB ratio. This project aims to improve the accuracy of W excitation and ionization atomic data using non-perturbative methods. Synthetic spectra generated from existing perturbative W data are used to guide the size of the new R-matrix calculations. The new data is used to generate a synthetic spectrum, which is compared with measured DIII-D ultraviolet spectra to determine the optimal lines for diagnosing W erosion. The new ionization rate coefficients are compared with literature values. The new S/XB ratio for the 400.9 nm line is compared with measured values and the density, temperature and metastable dependence of the S/XB ratios for new UV lines are investigated. Work supported by USDOE Grant DE-SC0015877.

  5. Deeply Virtual Pseudoscalar Meson Production with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Valery Kubarovsky; Paul Stoler; Ivan Bedlinsky

    2007-09-03

    Deeply virtual Compton scattering, cross sections and asymmetries for the pi^0 and eta exclusive electroproduction in a very wide kinematic range of Q^2, t and x_B have been measured with CLAS (Jlab). Initial analyzes already are showing remarkable results. These data will help us to better understand the transition from soft to hard mechanisms.

  6. FISH detection of ribosomal cistrons and assortment-distortion for X and B chromosomes in Dichroplus pratensis (Acrididae).

    Science.gov (United States)

    Bidau, C J; Rosato, M; Martí, D A

    2004-01-01

    Assortment-distortion with respect to the X and NOR activity of a rare mitotically stable B chromosome (B(N)), was examined in 16 males of Dichroplus pratensis (Acrididae: Melanoplinae) from Argentine populations. In 1B individuals, the X and B associate preferentially during prophase I reaching a maximum level of association at zygotene. Frequency of X/B association remains relatively high up to diplotene-diakinesis and decreases steeply towards metaphase I. The percent X/B association at each stage is positively influenced by association at the previous stage, and interindividual variability in X/B association decreases as the frequency of association increases. Both chromosomes tended to preferentially orientate toward the same pole at MI (mean ratio of 16 individuals, 1.50:1) which determined an excess of XB and 00 second spermatocytes over X0 and 0B ones (1.39:1). No significant differences occurred between the MI, AI and MII assortment ratios. Fluorescent in situ hybridisation (FISH) confirmed that the B chromosome carries ribosomal genes and helped to establish that, during spermiogenesis, both the B and the normal NOR-bearing chromosome (S8) are clustered near the centriole adjunct region of spermatids. However, FISH failed to reveal the existence of inactive ribosomal cistrons in the X chromosome, as previously suggested, thus providing no support to a simple origin of the B from the X.

  7. 77 FR 19227 - Gulf of Mexico Fishery Management Council; Public Meetings

    Science.gov (United States)

    2012-03-30

    ....--Outreach and Education Committee will review the Crisis Communication Plan and receive an update on the... National Oceanic and Atmospheric Administration RIN 0648-XB130 Gulf of Mexico Fishery Management Council... Management Council (Council) will convene a public meeting. DATES: The meeting will be held April 16-19,...

  8. Azimuthal correlation between the $(\\vec{p}_l,\\vec{p}_{X_b})$ and $(\\vec{p}_l,\\vec{P}_t)$ planes in the semileptonic rest frame decay of a polarized top quark: An $O(\\alpha_s)$ effect

    CERN Document Server

    Groote, S; Kadeer, A; Körner, J G

    2006-01-01

    The azimuthal correlation between the planes formed by the vectors $(\\vec{p}_l,\\vec{p}_{X_b})$ and $(\\vec{p}_l,\\vec{P}_t)$ in the semileptonic rest frame decay of a polarized top quark $t(\\uparrow) \\to X_b + l^+ + \

  9. 76 FR 80999 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Order Approving a Proposed Rule Change To...

    Science.gov (United States)

    2011-12-27

    ... negotiating fees, obtaining service level agreements, and executing service agreements directly with approved... Schedule, Section X(b) entitled ``Co-Location Services'' to establish a program for offering low latency....19b-4. \\3\\ See Securities Exchange Act Release No. 65689 (November 4, 2011), 76 FR 70187...

  10. Drug: D00478 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ode: L01XB01 Therapeutic category of drugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplastics...on [BR:br08302] Antineoplastics Alkylating Agents Procarbazine D00478 Procarbazine hydrochloride (JP16/USP) Antineoplastics...1 Procarbazine D00478 Procarbazine hydrochloride (JP16/USP) USP drug classificati

  11. Assistance tool commissioner of new algorithms of systems planning of therapy with ionizing; Herramienta de asistencia en el comisionado de nuevos algoritmos de sistemas de planificacion de terapia con radiaciones ionizantes

    Energy Technology Data Exchange (ETDEWEB)

    Reinado, D.; Ricos, B.; Alonso, S.; Chinillach, N.; Bellido, P.; Tortosa, R.

    2013-07-01

    The Commissioner of a new scheduling algorithm is associated with a high number of hours of work and measures. In order to optimize the development of the Commissioner for the AAA algorithms and Acuros XB within planning Eclipse (V.10) system marketed by Varian and have developed a tool in Microsoft Excel format where the different tests have been included to perform. (Author)

  12. Mapping QTLs for Fertility Restoration of Different Cytoplasmic Male Sterility Types in Rice Using Two Oryza sativa ×O. rufipogon Backcross Inbred Line Populations

    Directory of Open Access Journals (Sweden)

    Biao-lin Hu

    2016-01-01

    Full Text Available Hybrid rice breeding using cytoplasmic male sterility/fertility restoration (CMS/Rf systems plays an important role in ensuring global food security. Two backcross inbred line (BIL populations derived from either Xieqingzao B (XB//XB/Dongxiang wild rice (DWR (XXD or XB//DWR/XB (XDX were used to detect quantitative trait loci (QTLs for fertility restoration of Dwarf wild abortive- (DA-, Indonesia Paddy- (ID-, and DWR-type CMS in rice. Lines with ID- and DA-type CMS were testcrossed with both the XXD- and XDX-BILs, while the line with DWR-type CMS was testcrossed with the XDX-BILs only. A total of 16 QTLs for fertility restoration of CMS systems were identified, including three for DWR-type CMS, six for DA-type CMS, and seven for ID-type CMS. All of the additive alleles in the QTLs were derived from Oryza rufipogon. Eleven QTLs were clustered in five chromosomal regions, indicating that common Rf loci restored different CMS systems, and the favorable O. rufipogon alleles could be used to develop restorer lines for various CMS types by marker-assisted selection.

  13. 77 FR 16811 - Mid-Atlantic Fishery Management Council (MAFMC); Public Meetings

    Science.gov (United States)

    2012-03-22

    ... Fishery Management Council (Council) and its Executive Committee, its Ecosystem and Ocean Planning... Planning Committee will receive a presentation from the New England Fishery Management Council (NEFMC) and... National Oceanic and Atmospheric Administration RIN 0648-XB108 Mid-Atlantic Fishery Management...

  14. A System of Four Matrix Equations over von Neumann Regular Rings and Its Applications

    Institute of Scientific and Technical Information of China (English)

    Qing Wen WANG

    2005-01-01

    We consider the system of four linear matrix equations A1X = C1, XB2 = C2, A3XB3 = C3 and A4XB4 = C4 over(R) , an arbitrary yon Neumann regular ring with identity. A necessary and sufficient condition for the existence and the expression of the general solution to the system are derived. As applications, necessary and sufficient conditions are given for the system of matrix equations A1X = C1 and A3X = C3 to have a bisymmetric solution, the system of matrix equations A1X = C1and A3XB3 = C3 to have a perselfconjugate solution over(R) with an involution and char ≠(R)2,respectively. The representations of such solutions are also presented. Moreover, some auxiliary results on other systems over(R)are obtained. The previous known results on some systems of matrix equations are special cases of the new results.

  15. 77 FR 12574 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2012-03-01

    ... National Oceanic and Atmospheric Administration RIN 0648-XB037 Schedules for Atlantic Shark Identification... of public workshops. SUMMARY: Free Atlantic Shark Identification Workshops and Protected Species Safe... fishermen and shark dealers are required to attend a workshop to meet regulatory requirements and...

  16. 77 FR 22678 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Science.gov (United States)

    2012-04-17

    ... National Oceanic and Atmospheric Administration 50 CFR Part 648 RIN 0648- XB145 Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the Trimester 1 Longfin Squid Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...

  17. Morphology and mycelial growth rate of Pleurotus spp. strains from the Mexican mixtec region

    Directory of Open Access Journals (Sweden)

    P.C. Guadarrama-Mendoza

    2014-09-01

    Full Text Available Two native Pleurotus spp. strains (white LB-050 and pale pink LB-051 were isolated from rotten tree trunks of cazahuate (Ipomoea murucoides from the Mexican Mixtec Region. Both strains were chemically dedikaryotized to obtain their symmetrical monokaryotic components (neohaplonts. This was achieved employing homogenization time periods from 60 to 65 s, and 3 day incubation at 28 °C in a peptone-glucose solution (PGS. Pairing of compatible neohaplonts resulted in 56 hybrid strains which were classified into the four following hybrid types: (R1-n xB1-n, R1-n xB2-1, R2-n xB1-n and R2-n xB2-1. The mycelial growth of Pleurotus spp. monokaryotic and dikaryotic strains showed differences in texture (cottony or floccose, growth (scarce, regular or abundant, density (high, regular or low, and pigmentation (off-white, white or pale pink. To determine the rate and the amount of mycelium growth in malt extract agar at 28 °C, the diameter of the colony was measured every 24 h until the Petri dish was completely colonized. A linear model had the best fit to the mycelial growth kinetics. A direct relationship between mycelial morphology and growth rate was observed. Cottony mycelium presented significantly higher growth rates (p < 0.01 in comparison with floccose mycelium. Thus, mycelial morphology can be used as criterion to select which pairs must be used for optimizing compatible-mating studies. Hybrids resulting from cottony neohaplonts maintained the characteristically high growth rates of their parental strains with the hybrid R1-n xB1-n being faster than the latter.

  18. Concentration, ozone formation potential and source analysis of volatile organic compounds (VOCs) in a thermal power station centralized area: A study in Shuozhou, China.

    Science.gov (United States)

    Yan, Yulong; Peng, Lin; Li, Rumei; Li, Yinghui; Li, Lijuan; Bai, Huiling

    2017-04-01

    Volatile organic compounds (VOCs) from two sampling sites (HB and XB) in a power station centralized area, in Shuozhou city, China, were sampled by stainless steel canisters and measured by gas chromatography-mass selective detection/flame ionization detection (GC-MSD/FID) in the spring and autumn of 2014. The concentration of VOCs was higher in the autumn (HB, 96.87 μg/m(3); XB, 58.94 μg/m(3)) than in the spring (HB, 41.49 μg/m(3); XB, 43.46 μg/m(3)), as lower wind speed in the autumn could lead to pollutant accumulation, especially at HB, which is a new urban area surrounded by residential areas and a transportation hub. Alkanes were the dominant group at both HB and XB in both sampling periods, but the contribution of aromatic pollutants at HB in the autumn was much higher than that of the other alkanes (11.16-19.55%). Compared to other cities, BTEX pollution in Shuozhou was among the lowest levels in the world. Because of the high levels of aromatic pollutants, the ozone formation potential increased significantly at HB in the autumn. Using the ratio analyses to identify the age of the air masses and analyze the sources, the results showed that the atmospheric VOCs at XB were strongly influenced by the remote sources of coal combustion, while at HB in the spring and autumn were affected by the remote sources of coal combustion and local sources of vehicle emission, respectively. Source analysis conducted using the Positive Matrix Factorization (PMF) model at Shuozhou showed that coal combustion and vehicle emissions made the two largest contributions (29.98% and 21.25%, respectively) to atmospheric VOCs. With further economic restructuring, the influence of vehicle emissions on the air quality should become more significant, indicating that controlling vehicle emissions is key to reducing the air pollution.

  19. The X-Ray Luminosity Functions of Field Low-Mass X-Ray Binaries in Early-Type Galaxies: Evidence for a Stellar Age Dependence

    Science.gov (United States)

    Lehmer, B. D.; Berkeley, M.; Zezas, A.; Alexander, D. M.; Basu-Zych, A.; Bauer, F. E.; Brandt, W. N.; Fragos, T.; Hornschemeier, A. E.; Kalogera, V.; Ptak, A.; Sivakoff, G. R.; Tzanavaris, P.; Yukita, M.

    2014-01-01

    We present direct constraints on how the formation of low-mass X-ray binary (LMXB) populations in galactic fields depends on stellar age. In this pilot study, we utilize Chandra and Hubble Space Telescope (HST) data to detect and characterize the X-ray point source populations of three nearby early-type galaxies: NGC 3115, 3379, and 3384. The luminosity-weighted stellar ages of our sample span approximately equal to 3-10 Gyr. X-ray binary population synthesis models predict that the field LMXBs associated with younger stellar populations should be more numerous and luminous per unit stellar mass than older populations due to the evolution of LMXB donor star masses. Crucially, the combination of deep Chandra and HST observations allows us to test directly this prediction by identifying and removing counterparts to X-ray point sources that are unrelated to the field LMXB populations, including LMXBs that are formed dynamically in globular clusters, Galactic stars, and background AGN/galaxies. We find that the "young" early-type galaxy NGC 3384 (approximately equals 2-5 Gyr) has an excess of luminous field LMXBs (L(sub x) approximately greater than (5-10) × 10(exp 37) erg s(exp -1)) per unit K-band luminosity (L(sub K); a proxy for stellar mass) than the "old" early-type galaxies NGC 3115 and 3379 (approximately equals 8-10 Gyr), which results in a factor of 2-3 excess of L(sub X)/L(sub K) for NGC 3384. This result is consistent with the X-ray binary population synthesis model predictions; however, our small galaxy sample size does not allow us to draw definitive conclusions on the evolution field LMXBs in general. We discuss how future surveys of larger galaxy samples that combine deep Chandra and HST data could provide a powerful new benchmark for calibrating X-ray binary population synthesis models.

  20. Identifying crucial parameter correlations maintaining bursting activity.

    Directory of Open Access Journals (Sweden)

    Anca Doloc-Mihu

    2014-06-01

    Full Text Available Recent experimental and computational studies suggest that linearly correlated sets of parameters (intrinsic and synaptic properties of neurons allow central pattern-generating networks to produce and maintain their rhythmic activity regardless of changing internal and external conditions. To determine the role of correlated conductances in the robust maintenance of functional bursting activity, we used our existing database of half-center oscillator (HCO model instances of the leech heartbeat CPG. From the database, we identified functional activity groups of burster (isolated neuron and half-center oscillator model instances and realistic subgroups of each that showed burst characteristics (principally period and spike frequency similar to the animal. To find linear correlations among the conductance parameters maintaining functional leech bursting activity, we applied Principal Component Analysis (PCA to each of these four groups. PCA identified a set of three maximal conductances (leak current, [Formula: see text]Leak; a persistent K current, [Formula: see text]K2; and of a persistent Na+ current, [Formula: see text]P that correlate linearly for the two groups of burster instances but not for the HCO groups. Visualizations of HCO instances in a reduced space suggested that there might be non-linear relationships between these parameters for these instances. Experimental studies have shown that period is a key attribute influenced by modulatory inputs and temperature variations in heart interneurons. Thus, we explored the sensitivity of period to changes in maximal conductances of [Formula: see text]Leak, [Formula: see text]K2, and [Formula: see text]P, and we found that for our realistic bursters the effect of these parameters on period could not be assessed because when varied individually bursting activity was not maintained.

  1. Variable Low-Mass X-ray Binaries in Early-Type Galaxies

    CERN Document Server

    Sivakoff, Gregory R; Juett, Adrienne M; Sarazin, Craig L; Irwin, Jimmy A

    2007-01-01

    As the Chandra X-ray Observatory mission matures, increasing numbers of nearby galaxies are being observed multiple times, sampling the variability of extragalactic X-ray binaries on timescales extending from seconds to years. We present results on luminous low-mass X-ray binaries from several early-type galaxies. We show that instantaneous LMXB luminosity functions of early-type galaxies do not significantly change between observations; a relatively low fraction of sources are strongly variable on <~ 5 yr timescales. We discuss the implications that a relatively small number of transient LMXBs are being discovered in early-type galaxies.

  2. X-ray Observations of Neutron Star Binaries: Evidence for Millisecond Spins

    OpenAIRE

    Strohmayer, Tod E.

    2001-01-01

    High amplitude X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries (LMXB), a long sought goal of X-ray astronomy. I briefly review the status of our knowledge of these oscillations. ...

  3. Evolution of Low-mass X-Ray Binaries: The Effect of Donor Evaporation

    Science.gov (United States)

    Jia, Kun; Li, Xiang-Dong

    2016-10-01

    Millisecond pulsars (MSPs) are thought to originate from low-mass X-ray binaries (LMXBs). The discovery of eclipsing radio MSPs, including redbacks and black widows, indicates that evaporation of the donor star by the MSP’s irradiation takes place during the LMXB evolution. In this work, we investigate the effect of donor evaporation on the secular evolution of LMXBs, considering different evaporation efficiencies and related angular momentum loss. We find that for widening LMXBs, the donor star leaves a less massive white dwarf than without evaporation; for contracting systems, evaporation can speed up the evolution, resulting in dynamically unstable mass transfer and possibly the formation of isolated MSPs.

  4. Population synthesis of classical low-mass X-ray binaries in the Galactic Bulge

    Science.gov (United States)

    van Haaften, L. M.; Nelemans, G.; Voss, R.; van der Sluys, M. V.; Toonen, S.

    2015-07-01

    Aims: We model the present-day population of classical low-mass X-ray binaries (LMXBs) with neutron star accretors, which have hydrogen-rich donor stars. Their population is compared with that of hydrogen-deficient LMXBs, known as ultracompact X-ray binaries (UCXBs). We model the observable LMXB population and compare it to observations. We model the Galactic Bulge because it contains a well-observed population and it is the target of the Galactic Bulge Survey. Methods: We combine the binary population synthesis code SeBa with detailed LMXB evolutionary tracks to model the size and properties of the present-day LMXB population in the Galactic Bulge. Whether sources are persistent or transient, and what their instantaneous X-ray luminosities are, is predicted using the thermal-viscous disk instability model. Results: We find a population of ~2.1 × 103 LMXBs with neutron star accretors. Of these about 15-40 are expected to be persistent (depending on model assumptions), with luminosities higher than 1035 erg s-1. About 7-20 transient sources are expected to be in outburst at any given time. Within a factor of two these numbers are consistent with the observed population of bright LMXBs in the Bulge. This gives credence to our prediction of the existence of a population of ~1.6 × 103 LMXBs with low donor masses that have gone through the period minimum, and have present-day mass transfer rates below 10-11 M⊙ yr-1. Conclusions: Even though the observed population of hydrogen-rich LMXBs in the Bulge is larger than the observed population of (hydrogen-deficient) UCXBs, the latter have a higher formation rate. While UCXBs may dominate the total LMXB population at the present time, the majority would be very faint or may have become detached and produced millisecond radio pulsars. In that case UCXBs would contribute significantly more to the formation of millisecond radio pulsars than hydrogen-rich LMXBs.

  5. Evolution of Low-Mass X-ray Binaries: the Effect of Donor Evaporation

    CERN Document Server

    Jia, Kun

    2016-01-01

    Millisecond pulsars (MSPs) are thought to originate from low-mass X-ray binaries (LMXBs). The discovery of eclipsing radio MSPs including redbacks and black widows indicates that evaporation of the donor star by the MSP's irradiation takes place during the LMXB evolution. In this work, we investigate the effect of donor evaporation on the secular evolution of LMXBs, considering different evaporation efficiencies and related angular momentum loss. We find that for widening LMXBs, the donor star leaves a less massive white dwarf than without evaporation; for contracting systems, evaporation can speed up the evolution, resulting in dynamically unstable mass transfer and possibly the formation of isolated MSPs.

  6. Relativistic Iron Line Emission from the Neutron Star Low-mass X-ray Binary 4U 1636-536

    OpenAIRE

    Pandel, Dirk; Kaaret, Philip; Corbel, Stephane

    2008-01-01

    We present an analysis of XMM-Newton and RXTE data from three observations of the neutron star LMXB 4U 1636-536. The X-ray spectra show clear evidence of a broad, asymmetric iron emission line extending over the energy range 4-9 keV. The line profile is consistent with relativistically broadened Fe K-alpha emission from the inner accretion disk. The Fe K-alpha line in 4U 1636-536 is considerably broader than the asymmetric iron lines recently found in other neutron star LMXBs, which indicates...

  7. Identification of the donor in the X-ray binary GRS 1915+105

    CERN Document Server

    Greiner, J; McCaughrean, M J; Castro-Tirado, A J; Mennickent, R E

    2001-01-01

    We report on the results of medium-resolution spectroscopy of GRS 1915+105 in the near-infrared H and K band using the 8m VLT at ESO. We clearly identify absorption bandheads from 12CO and 13CO. Together with other features this results in a classification of the mass-donating star in this binary as a K-M III star, clearly indicating that GRS 1915+105 belongs to the class of low-mass X-ray binaries (LMXB).

  8. Exploding superstars understanding supernovae and gamma-ray bursts

    CERN Document Server

    Mazure, Alain

    2009-01-01

    The exceptional cosmic history and the fabulous destinies of exploding stars – supernovae and gamma-ray bursters – are highly fertile areas of research and are also very special tools to further our understanding of the universe. In this book, cosmologists Dr Alain Mazure and Dr Stéphane Basa throw light on the assemblage of facts, hypotheses and cosmological conclusions and show how these ‘beacons’ illuminate their immediate surroundings and allow us to study the vast cosmos, like searchlights revealing the matter comprising our universe.

  9. First superburst observed by INTEGRAL/JEM-X

    DEFF Research Database (Denmark)

    Chenevez, Jérôme

    X-ray bursters are neutron stars in low mass X-ray binaries where hydrogen and/or helium accretes on the surface, and explodes in recurrent thermonuclear runaways. Such type I X-ray bursts, characterized by a black-body emission, generally display a fast rise time followed by an exponential cooling...... carbon shell flashes in the layers below the surface of the neutron star, while the intermediately long bursts are generally explained by the unstable burning of a thick atmospheric layer of pure helium. On February 13, 2011, the Danish-built X-ray monitor JEM-X onboard the INTEGRAL satellite observed...

  10. New Eyes on the Universe Twelve Cosmic Mysteries and the Tools We Need to Solve Them

    CERN Document Server

    Webb, Stephen

    2012-01-01

    "New Eyes on the Universe -- Twelve Cosmic Mysteries and the Tools We Need to Solve Them" gives an up-to-date broad overview of some of the key issues in modern astronomy and cosmology. It describes the vast amount of observational data that the new generation of observatories and telescopes are currently producing, and how that data might solve some of the outstanding puzzles inherent in our emerging world view. Included are questions such as: What is causing the Universe to blow itself apart? What could be powering the luminous gamma-ray bursters? Where is all the matter in the Uni

  11. Focused study of thermonuclear bursts on neutron stars

    DEFF Research Database (Denmark)

    Chenevez, Jérôme

    X-ray bursters are a class of Low Mass X-Ray Binaries where accreted material from a donor star undergoes rapid thermonuclear burning in the surface layers of a neutron star. The flux released can temporarily exceed the Eddington limit and drive the photosphere to large radii. Such photospheric...... detection would thus probe the nuclear burning as well as the gravitational redshift from the neutron star. Moreover, likely observations of atomic X-ray spectral components reflected from the inner accretion disk have been reported. The high spectral resolution capabilities of Simbol X may therefore make...

  12. Long X-ray burst monitoring with INTEGRAL

    DEFF Research Database (Denmark)

    X-ray bursts are thermonuclear explosions on the surface of accreting neutron stars in low mass X-ray binary systems. In the frame of the INTEGRAL observational Key Programme over the Galactic Center a good number of the known X-ray bursters are frequently being monitored. An international...... collaboration lead by the JEM-X team at the Danish National Space Center has proposed to exploit the improved sensitivity of the INTEGRAL instruments to investigate the observational properties and physics up to high energies of exceptional burst events lasting between a few tens of minutes and several hours...

  13. Beasts in Lambda-CDM Zoo

    CERN Document Server

    Dolgov, A D

    2016-01-01

    Recent astronomical discoveries of supermassive black holes (quasars), gamma-bursters, supernovae, and dust at high redshifts, z = (5 --10), are reviewed. Such a dense population of the early universe is at odds with the conventional mechanisms of its possible origin. Similar data from the contemporary universe, which are also in conflict with natural expectations, are considered too. Two possible mechanisms are suggested, at least one of which can potentially solve all these problems. As a by-product of the last model, an abundant cosmological antimatter may be created.

  14. Sequences promoting the transcription of the human XA gene overlapping P450c21A correctly predict the presence of a novel, adrenal-specific, truncated form of tenascin-X

    Energy Technology Data Exchange (ETDEWEB)

    Tee, Meng Kian; Thomson, A.A.; Bristow, J.; Miller, W.L. [Univ. of California, San Francisco, CA (United States)

    1995-07-20

    A compact region in the human class III major histocompatibility locus contains the human genes for the fourth component of human complement (C4) and steroid 21-hydroxylase (P450c21) in one transcriptional orientation, while the gene for the extracellular matrix protein tenascin-X (TN-X) overlaps the last exon of P450c21 on the opposite strand of DNA in the opposite transcriptional orientation. This complex locus is duplicated into A and B loci, so that the organization is 5{prime}-C4A-21A-XA-C4B-21B-XB-3{prime}. Although this duplication event truncated the 65-kb X(B) gene to a 4.5-kb XA gene, the XA gene is transcriptionally active in the adrenal cortex. To examine the basis of the tissue-specific expression of XA and C4B, we cloned the 1763-bp region that lies between the cap sites for XA and C4B and analyzed its promoter activity in both the XA and the C4 orientations. Powerful, liver-specific sequences lie within the first 75 to 138 bp from the C4B cap site, and weaker elements lie within 128 bp of the XA cap site that function in both liver and adrenal cells. Because these 128 bp upstream from the XA cap site are perfectly preserved in the XB gene encoding TN-X, we sought to determine whether a transcript similar to XA arises within the SB gene. RNase protection assays, cDNA cloning, and RT/PCR show that adrenal cells contain a novel transcript, termed short XB (XB-S), which has the same open reading frame as TN-X. Cell-free translation and immunoblotting show that this transcript encodes a novel 74-kDa XB-S protein that is identical to the carboxy-terminal 673 residues of TN-X. Because this protein consists solely of fibronectin type III repeats and a fibrinogen-like domain, it appears to correspond to an evolutionary precursor of the tenascin family of extracellular matrix proteins. 40 refs., 6 figs.

  15. The Low-Mass X-ray Binary and Globular Cluster Connection in Virgo Cluster Early-type Galaxies: Optical Properties

    CERN Document Server

    Sivakoff, G R; Sarazin, C L; Blakeslee, J P; Ferrarese, L; Juett, A M; Mei, S; Peng, E W; Sivakoff, Gregory R.; Jord\\'{a}n, Andr\\'{e}s; Sarazin, Craig L.; Blakeslee, John P.; e}, Patrick C{\\^ o}t{\\'; Ferrarese, Laura; Juett, Adrienne M.; Mei, Simona; Peng, Eric W.

    2006-01-01

    (Abridged) Chandra and Hubble ACS observations of 11 early-type galaxies probe the low-mass X-ray binary (LMXB) - globular cluster (GC) connection. We explore the optical properties of 270 GCs with LMXBs and 6,488 GCs without LMXBs. More massive, redder, and more compact GCs are more likely to contain LMXBs. Unlike Galactic GCs, a large number of GCs with LMXBs have half-mass relaxation times > 2.5 Gyr. We fit the dependence of the expected number of LMXBs per GC, \\lambda_t, on the GC mass M, color (g-z), and half-mass radius r_{h,cor}, and find that \\lambda_t \\propto M^{1.24\\pm0.08} 10^{0.9^{+0.2}_{-0.1} (g-z)} r_{h,cor}^{-2.2^{+0.3}_{-0.4}}. Our fit rules out that the number of LMXBs per GC is linearly proportional to GC mass and that most GCs with high X-ray luminosities contain a single LMXB. The detailed dependence of \\lambda_t on GC properties appears essentially equivalent to a dependence on the encounter rate \\Gamma_h and the metallicity Z, \\lambda_t \\propto \\Gamma_h^{0.82\\pm0.05} Z^{0.39\\pm0.07}. Our...

  16. Measurements of Variability of Low Mass X-ray Binary Candidates in the Early-Type Galaxy NGC 4697 from Multi-Epoch Chandra X-ray Observations

    CERN Document Server

    Sivakoff, Gregory R; Juett, Adrienne M; Sarazin, Craig L; Irwin, Jimmy A

    2008-01-01

    Multi-epoch Chandra X-ray observations of nearby massive early-type galaxies open up the study of an important regime of low-mass X-ray binary (LMXB) behavior -- long term variability. In a companion paper, we report on the detection of 158 X-ray sources down to a detection/completeness limit of 0.6/1.4 x 10^{37} ergs/s using five Chandra observations of NGC 4697, one of the nearest (11.3 Mpc), optically luminous (M_B < -20), elliptical (E6) galaxy. In this paper, we report on the variability of LMXB candidates measured on timescales from seconds to years. At timescales of seconds to hours, we detect five sources with significant variability. Approximately 7% of sources show variability between any two observations, and 16+/-4% of sources do not have a constant luminosity over all five observations. Among variable sources, we identify eleven transient candidates, with which we estimate that if all LMXBs in NGC 4697 are long-term transients then they are on for ~ 100 yr and have a 7% duty cycle. These numbe...

  17. Instability windows and evolution of rapidly rotating neutron stars

    CERN Document Server

    Gusakov, Mikhail E; Kantor, Elena M

    2013-01-01

    We consider an instability of rapidly rotating neutron stars in low-mass X-ray binaries (LMXBs) with respect to excitation of r-modes (which are analogous to Earth's Rossby waves controlled by the Coriolis force). We argue that finite temperature effects in the superfluid core of a neutron star lead to a resonance coupling and enhanced damping (and hence stability) of oscillation modes at certain stellar temperatures. We demonstrate that neutron stars with high spin frequency spend a substantial amount of time at these `resonance' temperatures. This finding allows us to explain puzzling observations of hot rapidly rotating neutron stars in LMXBs and to predict a new class of hot non-accreting rapidly rotating neutron stars, some of which may have already been observed and tentatively identified as quiescent LMXB (qLMXB) candidates. We also impose a new theoretical limit on the neutron star spin frequency, explaining the cut-off spin frequency ~730 Hz, following from the statistical analysis of accreting milli...

  18. The nature of the Island and Banana States in Atoll sources and a Unified Model for Low Mass X-ray Binaries

    CERN Document Server

    Church, M J; Balucinska-Church, M

    2013-01-01

    We propose an explanation of the Island and Banana states and the relation between Atoll and Z-track sources, constituting a unified model for Low Mass X-ray Binaries (LMXB). We find a dramatic transition at a luminosity of 1 - 2.10^{37} erg/s above which the high energy cut-off E_CO of the Comptonized emission in all sources is low at a few keV. There is thermal equilibrium between the neutron star at ~2 keV and the Comptonizing accretion disk corona (ADC) causing the low E_CO in the Banana state of Atolls and all states of the Z-track sources. Below this luminosity, E_CO increases towards 100 keV causing the hardness of the island state. Thermal equilibrium is lost, the ADC becoming much hotter than the neutron star via an additional coronal heating mechanism. This suggests a unified model of LMXB: the Banana state is a basic state with the mass accretion rate Mdot increasing, corresponding to the Normal Branch of Z-track sources. The Island state has high ADC temperature, this state not existing in the Z-t...

  19. Swift-BAT Survey of Galactic Sources: Catalog and Properties of the Populations

    Energy Technology Data Exchange (ETDEWEB)

    Voss, R.; /Garching, Max Planck Inst., MPE; Ajello, M.; /SLAC /KIPAC, Menlo Park

    2010-08-27

    We study the populations of X-ray sources in the Milky Way in the 15-55 keV band using a deep survey with the BAT instrument aboard the Swift observatory. We present the logN-logS distributions of the various source types and we analyze their variability and spectra. For the low-mass X-ray binaries (LMXBs) and the high-mass X-ray binaries (HMXBs) we derive the luminosity functions to a limiting luminosity of L{sub X} {approx} 7 x 10{sup 34} erg s{sup -1}. Our results confirm the previously found flattening of the LMXB luminosity function below a luminosity of L{sub X} {approx} 10{sup 37} erg s{sup -1}. The luminosity function of the HMXBs is found to be significantly flatter in the 15-55 keV band than in the 2-10 keV band. From the luminosity functions we estimate the ratios of the hard X-ray luminosity from HMXBs to the star-formation rate, and the LMXB luminosity to the stellar mass. We use these to estimate the X-ray emissivity in the local universe from X-ray binaries and show that it constitutes only a small fraction of the hard X-ray background.

  20. Tidal capture formation of Low Mass X-Ray Binaries from wide binaries in the field

    CERN Document Server

    Michaely, Erez

    2015-01-01

    We present a potentially efficient dynamical formation scenario for Low Mass X-ray Binaries (LMXBs) in the field, focusing on black-hole (BH) LMXBs. In this formation channel LMXBs are formed from wide binaries $(>1000$ AU) with a BH component and a stellar companion. The wide binary is perturbed by fly-by's of field stars and its orbit random-walks and changes over time. This diffusion process can drive the binary into a sufficiently eccentric orbit such that the binary components tidally interact at peri-center and the binary evolves to become a short period binary, which eventually evolves into an LMXB. The formation rate of LMXBs through this channel mostly depends on the number of such BH wide binaries progenitors, which in turn depends on the velocity kicks imparted to BHs (or NSs) at birth. We consider several models for the formation and survival of such wide binaries, and calculate the LMXB formation rates for each model. We find that models where BHs form through direct collapse with no/little natal...

  1. Formation scenarios and mass-radius relation for neutron stars

    CERN Document Server

    Zdunik, J L

    2011-01-01

    Neutron star crust, formed via accretion of matter from a companion in a low-mass X-ray binary (LMXB), has an equation of state (EOS) stiffer than that of catalyzed matter. At a given neutron star mass, M, the radius of a star with an accreted crust is therefore larger, by DR(M), than for usually considered star built of catalyzed matter. Using a compressible liquid drop model of nuclei, we calculate, within the one-component plasma approximation, the EOSs corresponding to different nuclear compositions of ashes of X-ray bursts in LMXB. These EOSs are then applied for studying the effect of different formation scenarios on the neutron-star mass-radius relation. Assuming the SLy EOS for neutron star's liquid core, derived by Douchin & Haensel (2001), we find that at M=1.4 M_sun the star with accreted crust has a radius more than 100 m larger that for the crust of catalyzed matter. Using smallness of the crust mass compared to M, we derive a formula that relates DR(M) to the difference in the crust EOS. Thi...

  2. Models of low-mass helium white dwarfs including gravitational settling, thermal and chemical diffusion, and rotational mixing

    CERN Document Server

    Istrate, Alina; Tauris, Thomas M; Langer, Norbert; Stancliffe, Richard J; Grassitelli, Luca

    2016-01-01

    A large number of extremely low-mass helium white dwarfs (ELM WDs) have been discovered in recent years. The majority of them are found in close binary systems suggesting they are formed either through a common-envelope phase or via stable mass transfer in a low-mass X-ray binary (LMXB) or a cataclysmic variable (CV) system. Here, we investigate the formation of these objects through the LMXB channel with emphasis on the proto-WD evolution in environments with different metallicities. We study, for the first time, the combined effects of rotational mixing and element diffusion (e.g. gravitational settling, thermal and chemical diffusion) on the evolution of proto-WDs and on the cooling properties of the resulting WDs. We present state-of-the-art binary stellar evolution models computed with MESA for metallicities between Z=0.0002 and Z=0.02, producing WDs with masses between 0.16-0.45 M$_{\\odot}$. Our results confirm that element diffusion plays a significant role in the evolution of proto-WDs that experience...

  3. Transient Low-Mass X-Ray Binary Populations in Elliptical Galaxies NGC 3379 and NGC 4278

    CERN Document Server

    Fragos, T; Willems, B; Belczynski, K; Fabbiano, G; Brassington, N J; Kim, D -W; Angelini, L; Davies, R L; Gallagher, J S; King, A R; Pellegrini, S; Trinchieri, G; Zepf, S E; Zezas, A

    2009-01-01

    We propose a physically motivated and self-consistent prescription for the modeling of transient neutron star (NS) low-mass X-ray binary (LMXB) properties, such as duty cycle (DC), outburst duration and recurrence time. We apply this prescription to the population synthesis (PS) models of field LMXBs presented by Fragos et al. (2008), and compare the transient LMXB population to the Chandra X-ray survey of the two elliptical galaxies NGC 3379 and NGC 4278, which revealed several transient sources (Brassington et al., 2008, 2009). We are able to exclude models with a constant DC for all transient systems, while models with a variable DC based on the properties of each system are consistent with the observed transient populations. We predict that the majority of the observed transient sources in these two galaxies are LMXBs with red giant donors. Our comparison suggests that LMXBs formed through evolution of primordial field binaries are dominant in globular cluster (GC) poor elliptical galaxies, while they sti...

  4. Low-Mass X-Ray Binaries, Millisecond Radio Pulsars, and the Cosmic Star Formation Rate

    CERN Document Server

    White, N E; White, Nicholas E.; Ghosh, Pranab

    1998-01-01

    We report on the implications of the peak in the cosmic star-formation rate (SFR) at redshift z ~ 1.5 for the resulting population of low-mass X-ray binaries(LMXB) and for that of their descendants, the millisecond radio pulsars (MRP). Since the evolutionary timescales of LMXBs, their progenitors, and their descendants are thought be significant fractions of the time-interval between the SFR peak and the present epoch, there is a lag in the turn-on of the LMXB population, with the peak activity occurring at z ~ 0.5 - 1.0. The peak in the MRP population is delayed further, occurring at z < 0.5. We show that the discrepancy between the birthrate of LMXBs and MRPs, found under the assumption of a stead-state SFR, can be resolved for the population as a whole when the effects of a time-variable SFR are included. A discrepancy may persist for LMXBs with short orbital periods, although a detailed population synthesis will be required to confirm this. Further, since the integrated X-ray luminosity distribution of...

  5. XTE J1701-462 and its Implications for the Nature of Subclasses in Low-Magnetic-Field Neutron Star Low-Mass X-Ray Binaries

    CERN Document Server

    Homan, Jeroen; Fridriksson, Joel K; Remillard, Ronald A; Wijnands, Rudy; Mendez, Mariano; Lin, Dacheng; Altamirano, Diego; Casella, Piergiorgio; Belloni, Tomaso; Lewin, Walter H G

    2010-01-01

    We report on an analysis of RXTE data of the transient neutron star low-mass X-ray binary (NS-LMXB) XTE J1701-462, obtained during its 2006-2007 outburst. The X-ray properties of the source changed between those of various types of NS-LMXB subclasses. At high luminosities the source switched between two types of Z source behavior and at low luminosities we observed a transition from Z source to atoll source behavior. These transitions between subclasses primarily manifest themselves as changes in the shapes of the tracks in X-ray color-color and hardness-intensity diagrams, but they are accompanied by changes in the kHz quasi-periodic oscillations, broad-band variability, burst behavior, and/or X-ray spectra. We find that the low-energy X-ray flux is a good parameter to track the gradual evolution of the tracks in color-color and hardness-intensity diagrams, allowing us to resolve the evolution of the source in greater detail than before and relate the observed properties to other NS-LMXBs. We further find th...

  6. The X-ray luminosity function of low mass X-ray binaries in early-type galaxies, their metal-rich, and metal-poor globular clusters

    CERN Document Server

    Peacock, Mark B

    2015-01-01

    We present the X-ray luminosity function (XLF) of low mass X-ray binaries (LMXBs) in the globular clusters (GCs) and fields of seven early-types galaxies. These galaxies are selected to have both deep Chandra observations, which allow their LMXB populations to be observed to X-ray luminosities of $10^{37}-10^{38}$ erg/s, and HST optical mosaics which enable the X-ray sources to be separated into field LMXBs, GC LMXBs, and contaminating background and foreground sources. We find that at all luminosities the number of field LMXBs per stellar mass is similar in these galaxies. This suggests that the field LMXB populations in these galaxies are not effected by the GC specific frequency, and that properties such as binary fraction and the stellar initial mass function are either similar across the sample, or change in a way that does not effect the number of LMXBs. We compare the XLF of the field LMXBs to that of the GC LMXBs and find that they are significantly different with a p-value of $3\\times10^{-6}$ (equiva...

  7. Spectral-Timing Analysis of the Lower kHz QPO in the Low-Mass X-ray Binary Aquila X-1

    CERN Document Server

    Troyer, Jon S

    2016-01-01

    Spectral-timing products of kilohertz quasi-periodic oscillations (kHz QPOs) in low-mass X-ray binary (LMXB) systems, including energy- and frequency-dependent lags, have been analyzed previously in 4U 1608-52, 4U 1636-53, and 4U 1728-34. Here, we study the spectral-timing properties of the lower kHz QPO of the neutron star LMXB Aquila X-1 for the first time. We compute broadband energy lags, as well as energy-dependent lags and the covariance spectrum using data from the Rossi X-ray Timing Explorer (RXTE). We find very similar characteristics to other previously studied systems, including soft lags of $\\sim$30 $\\mu$s between the 3.0 - 8.0 keV and 8.0 - 20.0 keV energy bands at the average QPO frequency. We also find lags that show a nearly monotonic trend with energy, with the highest energy photons arriving first. The covariance spectrum of the lower kHz QPO is well fit by a thermal Comptonization model, though we find a higher seed photon temperature compared to the mean spectrum, which was also seen in Pe...

  8. Athena's Constraints on the Dense Matter Equation of State from Quiescent Low Mass X-ray Binaries

    Science.gov (United States)

    Guillot, Sebastien

    2016-07-01

    The study of neutron star quiescent low-mass X-ray binaries (qLMXBs) will address one of the science goals of the Athena X-ray observatory. The study of the soft X-ray thermal emission from the neutron star surface in qLMXBs is a crucial tool to place constrains on the dense matter equation of state and understand the interior structure of neutron stars. I will briefly review this method, its strengths and current weaknesses and limitations, as well as the current constraints on the equation of state from qLMXBs. The superior sensitivity of Athena will permit the acquisition of unprecedentedly high signal-to-noise spectra from these sources. It has been demonstrated that a single qLMXB, even with a high signal-to-noise spectrum, will not place useful constraints on the dense matter equation of state. However, a combination of qLMXB spectra has shown great promises of obtaining tight constraints on the equation of state. I will discuss the expected prospects for observations of qLMXBs and in particular, I will show that very tight constraints on the equation of state can be obtained from the observations of qLMXBs with the Athena X-ray observatory (even with a 10 % uncertainty on the flux calibration).

  9. XMM-NEWTON FINDS THAT SAX J1750.8-2900 MAY HARBOR THE HOTTEST, MOST LUMINOUS KNOWN NEUTRON STAR

    Energy Technology Data Exchange (ETDEWEB)

    Lowell, A. W.; Tomsick, J. A.; Bodaghee, A.; Boggs, S. E. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Heinke, C. O. [Department of Physics, University of Alberta, Room 238 CEB, Edmonton, AB T6G 2G7 (Canada); Kaaret, P. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Chaty, S.; Rodriguez, J. [AIM-Astrophysique Instrumentation Modelisation (UMR 7158 CEA/CNRS/Universite Paris 7 Denis Diderot), CEA Saclay, DSM/IRFU/Service d' Astrophysique, Bat. 709, L' Orme des Merisiers, FR-91 191 Gif-sur-Yvette Cedex (France); Walter, R., E-mail: alowell@ssl.berkeley.edu [INTEGRAL Science Data Centre, Observatoire de Geneve, Universite de Geneve, Chemin d' Ecogia, 16, 1290 Versoix (Switzerland)

    2012-04-20

    We have performed the first sensitive X-ray observation of the low-mass X-ray binary (LMXB) SAX J1750.8-2900 in quiescence with XMM-Newton. The spectrum was fit to both a classical blackbody model, and a non-magnetized, pure hydrogen neutron star (NS) atmosphere model. A power-law component was added to these models, but we found that it was not required by the fits. The distance to SAX J1750.8-2900 is known to be D = 6.79 kpc from a previous analysis of photospheric radius expansion bursts. This distance implies a bolometric luminosity (as given by the NS atmosphere model) of (1.05 {+-} 0.12) Multiplication-Sign 10{sup 34} (D/6.79 kpc){sup 2} erg s{sup -1}, which is the highest known luminosity for a NS LMXB in quiescence. One simple explanation for this surprising result could be that the crust and core of the NS were not in thermal equilibrium during the observation. We argue that this was likely not the case, and that the core temperature of the NS in SAX J1750.8-2900 is unusually high.

  10. X-ray Luminosity Functions of Subgalactic Regions in the Whirlpool Galaxy (M51)

    Science.gov (United States)

    Markwardt, Larissa; Lehmer, Bret; Eufrasio, Rafael; Basu-Zych, Antara; Fragos, Tassos; Hornschemeier, Ann E.; Kalogera, Vassiliki; Ptak, Andrew; Tzanavaris, Panayiotis; Zezas, Andreas

    2017-01-01

    We present X-ray luminosity functions (XLFs) of X-ray binary (XRB) populations in subgalactic regions in M51, which were selected to have varying levels of low-mass XRBs (LMXBs) and high-mass XRBs (HMXBs). Previous studies have found that the total X-ray luminosity of a galaxy is correlated with its star formation rate (SFR) and stellar mass (M*) according to the equation Lx = αM* + βSFR, where α and β are scaling constants. This result is based on integrated galaxy-wide X-ray luminosities, SFRs, and stellar masses. Here, our goal is to determine this relationship using XLFs within multiple subregions, selected by specific star-formation rate (SFR/M*), of one galaxy (M51). This selection allows us to decompose contributions from LMXB and HMXB populations separately. From this decomposition, we find similar scaling relations to Lehmer et al. (2010), and also find XLF shapes and normalizations that are consistent with past studies of elliptical galaxies (LMXB XLF) and star-forming active galaxies (HMXB XLF). This suggests that our technique is effective and that the star formation history of M51 does not deviate significantly from the average galaxy in the local Universe.

  11. ASTRO-H White Paper - Low-mass X-ray Binaries

    CERN Document Server

    Done, C; Cackett, E; Herder, J W den; Dotani, T; Enoto, T; Ferrigno, C; Kallman, T; Kohmura, T; Laurent, P; Miller, J; Mineshige, S; Mori, H; Nakazawa, K; Paerels, F; Sakurai, S; Soong, Y; Sugita, S; Takahashi, H; Tamagawa, T; Tanaka, Y; Terada, Y; Uno, S

    2014-01-01

    There is still 10-20% uncertainty on the neutron star (NS) mass-radius relation. These uncertainties could be reduced by an order of magnitude through an unambiguous measure of M/R from the surface redshift of a narrow line, greatly constraining the Equation of State for ultra-dense material. It is possible that the SXS on ASTRO-H can detect this from an accreting neutron star with low surface velocity in the line of sight i.e. either low inclination or low spin. Currently there is only one known low inclination LMXB, Ser X-1, and one known slow spin LMXB, J17480-2446 in Terzan 5. Ser X-1 is a persistent source which is always in the soft state (banana branch), where the accreting material should form a equatorial belt around the neutron star. A pole-on view should then allow the NS surface to be seen directly. A 100 ks observation should allow us to measure M/R if there are any heavy elements in the photosphere at the poles. Conversely, J17480-2446 in Terzan 5 is a transient accretion powered millisecond pul...

  12. Fast and slow magnetic deflagration fronts in Type I X-ray bursts

    CERN Document Server

    Cavecchi, Yuri; Watts, Anna L; Braithwaite, Jonathan

    2015-01-01

    Type I X-ray bursts are produced by thermonuclear runaways that develop on accreting neutron stars. Once one location ignites, the flame propagates across the surface of the star. Flame propagation is fundamental in order to understand burst properties like rise time and burst oscillations. Previous work quantified the effects of rotation on the front, showing that the flame propagates as a deflagration and that the front strongly resembles a hurricane. However the effect of magnetic fields was not investigated, despite the fact that magnetic fields strong enough to have an effect on the propagating flame are expected to be present on many bursters. In this paper we show how the coupling between fluid layers introduced by an initially vertical magnetic field plays a decisive role in determining the character of the fronts that are responsible for the Type I bursts. In particular, on a star spinning at 450 Hz (typical among the bursters) we test seed magnetic fields of $10^{7} - 10^{10}$ G and find that for th...

  13. Energy Crisis in Astrophysics (Black Holes vs. N-Body Metrics)

    CERN Document Server

    Alley, C O; Mizobuchi, Y; Yilmaz, H; Alley, Carroll O; Leiter, Darryl L; Mizobuchi, Yutaka; Yilmaz, Huseyin

    1999-01-01

    The recent observation of the gamma ray burster GRB 990123, requiring at least two solar masses of energy in gamma radiation alone, created an energy crisis in astrophysics (Schilling 1999). We discuss a theorem which states that, of all four-dimensional curved spacetime theories of gravity viable with respect to the four classical weak field tests, only one unique case, the Yilmaz theory, has interactive N-body (multiparticle) solutions and this unique case has no event horizons. The theorem provides strong theoretical support for Robertson's explanation of the large energy output of the gamma ray burster GRB 990123 (Robertson 1999b). This explanation requires a switch from black holes (a 1-body solution with horizon) to the case of horizon-free interactive N-body solutions. In addition to the good news that the long sought N-body solutions are found, this unique case enjoys further strong support from other areas of gravitational physics. This development does not rule out GRB models with beaming, which can...

  14. Observations of Type I Bursts from Neutron Stars

    CERN Document Server

    Swank, J H

    2000-01-01

    Observations of Type I X-ray bursts have long been taken as evidence that the sources are neutron stars. Black body models approximate the spectral data and imply a suddenly heated neutron star cooling over characteristic times of seconds to minutes. The phenomena are convincingly explained in terms of nuclear burning of accreted gas on neutron stars with low mass companion stars. Prospects are promising that detailed theory and data from RXTE and future missions will lead to better determinations of important physical parameters (neutron star mass and radius, composition of the accreting gas, distance of the source). Among the variety of bursts observed, there are probably representatives of different kinds of explosive burning. RXTE's discovery of a 2.5 ms persistent coherent period from one Type I burster has now linked bursters indisputably to the epitome of a neutron star, a fast spinning magnetic compact object. Oscillations in some bursts had already been thought to arise from the neutron stars' rotati...

  15. Hall MHD Equilibrium of Accelerated Compact Toroids

    Science.gov (United States)

    Howard, S. J.; Hwang, D. Q.; Horton, R. D.; Evans, R. W.; Brockington, S. J.

    2007-11-01

    We examine the structure and dynamics of the compact toroid's magnetic field. The compact toroid is dramatically accelerated by a large rail-gun Lorentz force density equal to j xB. We use magnetic data from the Compact Toroid Injection Experiment to answer the question of exactly where in the system j xB has nonzero values, and to what extent we can apply the standard model of force-free equilibrium. In particular we present a method of analysis of the magnetic field probe signals that allows direct comparison to the predictions of the Woltjer-Taylor force-free model and Turner's generalization of magnetic relaxation in the presence of a non-zero Hall term and fluid vorticity.

  16. Accessing the longitudinally polarized photon content of the proton

    Science.gov (United States)

    Mukherjee, A.; Pisano, C.

    2004-08-01

    We investigate the QED Compton process in longitudinally polarized lepton-proton scattering both in the elastic and inelastic channels and show that the cross section can be expressed in terms of the polarized equivalent photon distribution of the proton. We provide the necessary kinematical constraints to extract the polarized photon content of the proton using this process at HERMES, COMPASS, and eRHIC. We also discuss the suppression of the major background process coming from virtual Compton scattering. We point out that such an experiment can give valuable information on g1(xB,Q2) in the small xB, broad Q2 region at the future polarized collider eRHIC and especially in the lower Q2, medium xB region in fixed target experiments.

  17. The halogen-bonded adduct 1,4-bis(pyridin-4-ylbuta-1,3-diyne–1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8-hexadecafluoro-1,8-diiodooctane (1/1

    Directory of Open Access Journals (Sweden)

    Giancarlo Terraneo

    2013-03-01

    Full Text Available In the crystal structure of the title compound, C8F16I2·C14H8N2, the molecules form infinite chains parallel to [2-11] through two symmetry-independent C—I...N halogen bonds (XBs. As commonly found, the perfluoroalkyl molecules segregate from the hydrocarbon ones, forming a layered structure. Apart from the XBs, the only contact below the sum of van der Waals radii is a weak H...F contact. The topology of the network is a nice example of the paradigm of the expansion of ditopic starting modules; the XB leads to the construction of infinite supramolecular chains along [2-11] formed by alternating XB donors and acceptors.

  18. The geometry of the chlorine dioxide anion ClO2-: Ab initio calculation and Franck-Condon analysis

    Science.gov (United States)

    Zheng, Haiyan; Zhang, Xiaowei; Li, Renzhong; Liang, Jun; Cui, Zhifeng

    2007-11-01

    Geometry optimization and harmonic vibrational frequency calculations were performed on the XB state of ClO 2 and XA state of ClO2-. The electron affinity energies of ClO 2 were calculated up to CCSD(T) level. Franck-Condon analyses and spectral simulations were carried out on the ClO(XB)-ClO2-(XA) photodetachment process. In addition, the equilibrium geometry parameters, r(ClO) = 1.567 ± 0.002 Å and ∠(OClO) = 116.5 ± 0.5°, of the XA state of ClO2-, were derived in the spectral simulation. Our conclusions regarding the anion geometry suggest a reinterpretation of the results of Gilles et al. [M.K. Gilles, M.L. Polak, W.C. Lineberger, J. Chem. Phys. 96 (1992) 8012].

  19. Next-to-leading order corrections to the hadron energy distribution from polarized top quark decay in the general two Higgs doublet model

    CERN Document Server

    Nejad, S Mohammad Moosavi

    2016-01-01

    We study the scaled-energy ( x_B) distribution of bottom-flavored mesons (B) inclusively produced in polarized top quark decays at next-to-leading order in the two-Higgs-doublet model. To study the energy spectrum of B-mesons we present, for the first time, an analytical expression for the NLO corrections to the partial decay width t(\\uparrow)-> H^+b taking the H^+ boson to be stable. Specifically, we study the effect of gluon fragmentation which leads to an appreciable reduction in the partial decay width at low values of x_B. To describe both the b-quark and the gluon hadronization we apply fragmentation functions extracted through a global fit to e^+e^- data from CERN LEP1 and SLAC SLC exploiting their universality and scaling violations.

  20. Growth of EuO single crystals at reduced temperatures

    Science.gov (United States)

    Ramirez, Daniel C.; Besara, Tiglet; Whalen, Jeffrey B.; Siegrist, Theo

    2017-01-01

    Single crystals of (E u1 -xB ax)O have been grown in a molten barium-magnesium metal flux at temperatures up to 1000 °C, producing single crystals of (E u1 -xB ax)O with barium doping levels ranging from x =0.03 to x =0.25 . Magnetic measurements show that the ferromagnetic Curie temperature TC correlates with the Ba doping levels, and a modified Heisenberg model was used to describe the stoichiometry dependence of TC. Extrapolation of the results indicates that a sample with Ba concentration of x =0.72 should have a TC of 0 K, potentially producing a quantum phase transition in this material.

  1. Halogen- and hydrogen-bonding catenanes for halide-anion recognition.

    Science.gov (United States)

    Gilday, Lydia C; Beer, Paul D

    2014-07-01

    Halogen-bonding (XB) interactions were exploited in the solution-phase assembly of anion-templated pseudorotaxanes between an isophthalamide-containing macrocycle and bromo- or iodo-functionalised pyridinium threading components. (1)H NMR spectroscopic titration investigations demonstrated that such XB interpenetrated assemblies are more stable than analogous hydrogen bonding (HB) pseudorotaxanes. The stability of the anion-templated halogen-bonded pseudorotaxane architectures was exploited in the preparation of new halogen-bonding interlocked catenane species through a Grubbs' ring-closing metathesis (RCM) clipping methodology. The catenanes' anion recognition properties in the competitive CDCl(3)/CD(3) OD 1:1 solvent mixture revealed selectivity for the heavier halides iodide and bromide over chloride and acetate.

  2. Hard Exclusive Reactions at Jlab

    Energy Technology Data Exchange (ETDEWEB)

    Kubarovsky, Valery P. [JLAB

    2011-09-20

    Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) have been carried out at Jefferson Lab. DVCS helicity--dependent and helicity--independent cross sections and beam spin asymmetries have been measured, as well as cross sections and asymmetries for the $\\pi^0$, $\\eta$, $\\rho^0$, $\\rho^+$, $\\omega$ and $\\phi$ for exclusive electroproduction. The data were taken in a wide kinematic range in $Q^2$=1--4.5 GeV$^2$, $x_B$=0.1--0.5, and $|t|$ up to 2 GeV$^2$. The presented results offer a unique opportunity to study the structure of the nucleon at the parton level as one has access to Bjorken $x_B$ and momentum transfer to the nucleon $t$ at the same time.

  3. Measurements of DVCS and DVMP at COMPASS

    CERN Document Server

    Ferrero, Andrea

    2011-01-01

    The study of DVCS and DVMP processes over a wide range in $x_{B}$ is an outstanding part of the scientific proposal for the COMPASS program after 2011. The measurement of the double-differential DVCS cross-section will provide information on the transverse size of the nucleon as function of $x_{B}$, often referred to as "nucleon tomography". Also, the combination of data samples collected with opposite beam charge and polarization will allow to single out terms related to the GPD $H$. The physics goals of the COMPASS GPD program will be discussed in detail, and projections on the achievable statistical and systematic accuracies will be given. The sensitivity of the COMPASS experimental apparatus to the DVCS signal has been investigated during dedicated pilot measurements in the years 2008 and 2009. Preliminary results on the observed DVCS and Bethe-Heitler signals are presented, and the comparison with Monte-Carlo simulations is discussed.

  4. Degree of Conversion and BisGMA, TEGDMA, UDMA Elution from Flowable Bulk Fill Composites.

    Science.gov (United States)

    Lempel, Edina; Czibulya, Zsuzsanna; Kovács, Bálint; Szalma, József; Tóth, Ákos; Kunsági-Máté, Sándor; Varga, Zoltán; Böddi, Katalin

    2016-05-20

    The degree of conversion (DC) and the released bisphenol A diglycidyl ether dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) monomers of bulk-fill composites compared to that of conventional flowable ones were assessed using micro-Raman spectroscopy and high performance liquid chromatography (HPLC). Four millimeter-thick samples were prepared from SureFil SDR Flow (SDR), X-tra Base (XB), Filtek Bulk Fill (FBF) and two and four millimeter samples from Filtek Ultimate Flow (FUF). They were measured with micro-Raman spectroscopy to determine the DC% of the top and the bottom surfaces. The amount of released monomers in 75% ethanol extraction media was measured with HPLC. The differences between the top and bottom DC% were significant for each material. The mean DC values were in the following order for the bottom surfaces: SDR_4mm_20s > FUF_2mm_20s > XB_4mm_20s > FBF_4mm_20s > XB_4mm_10s > FBF_4mm_10s > FUF_4mm_20s. The highest rate in the amount of released BisGMA and TEGDMA was found from the 4 mm-thick conventional flowable FUF. Among bulk-fills, FBF showed a twenty times higher amount of eluted UDMA and twice more BisGMA; meanwhile, SDR released a significantly higher amount of TEGDMA. SDR bulk-fill showed significantly higher DC%; meanwhile XB, FBF did not reach the same level DC, as that of the 2 mm-thick conventional composite at the bottom surface. Conventional flowable composites showed a higher rate of monomer elution compared to the bulk-fills, except FBF, which showed a high amount of UDMA release.

  5. NONEXISTENCE IN POWER AND GAMMA DENSITY REGRESSION, SUM OF NONNEGATIVE TERMS

    Institute of Scientific and Technical Information of China (English)

    Josef Bukac

    2005-01-01

    When we use the power function a(c + x)b and gamma density axbe-cx to fit the data by the least squares method, we have to address the question of existence. The closure of the set of each type of these functions defined on a finite domain is determined. We derive a way to determine the closure of a sum of nonnegativefunctions if the closures of the summands are available.

  6. Spectroscopic studies of lead antimony borate glasses doped with erbium ions

    Science.gov (United States)

    Reddy, M. Chandra Shekhar; Goud, K. Krishna Murthy; Dharmaiah, P.; Rao, B. Appa

    2013-06-01

    Antimony borate glasses of the composition 30PbO-25Sb2O3-(45-x)B2O3-xEr2O3 with x = 0 to 1.0 in steps of 0.2 were prepared by the melt-quenching method. Various physical parameters. radiative parameters, transition probability A, branching ratio β and the radiative life time τ for different emission levels of Er3+ ions, have been evaluated.

  7. G(A, B)-labeling of cacti over groups

    Science.gov (United States)

    Egarguin, Neil Jerome A.; Panopio, Rolando G.

    2016-06-01

    Let G be a group with nonempty subsets A and B. The graph G(A, B) is the simple graph obtained by deleting all loops from the graph whose vertex set is A and where vertices x and y are adjacent if and only if there is a b ∈ B such that xb = y or yb = x. In this paper, we present realizations of some cacti as G(A, B)'s.

  8. Mineral Separation in a CELSS by Ion-exchange Chromatography

    Science.gov (United States)

    Ballou, E. V.; Spitze, L. A.; Wong, F. W.; Wydeven, T.; Johnson, C. C.

    1982-01-01

    Operational parameters pertinent to ion exchange chromatography separation were identified. The experiments were performed with 9 mm diameter ion exchange columns and conventional column accessories. The cation separation beds were packed with AG 50W-X2 strong acid cation exchange resin in H(+) form and 200-400 dry mesh particle size. The stripper beds used in some experiments were packed with AG 1-XB strong base cation exchange resin in OH(-) form and 200-400 dry mesh particle size.

  9. Evolution of gluon TMDs from small to moderate x

    CERN Document Server

    Tarasov, Andrey

    2015-01-01

    Recently we obtained an evolution equation of gluon TMDs, which addresses a problem of unification of different kinematic regimes. It describes evolution in the whole range of Bjorken $x_B$ and the whole range of transverse momentum $k_\\perp$. In this notes I study different limits of this evolution equation and show how it yields several well-known and some previously unknown results.

  10. Effects of gamma-ray irradiation on optical properties of ZnO-PbO-B2O3 glasses

    DEFF Research Database (Denmark)

    Sharma, G.; Thind, K.S.; Manupriya, -;

    2006-01-01

    Effects of gamma-ray irradiation on some optical properties of xZnO(.)2xPbO(.)(1-3x)B2O3 glasses have been studied in the wavelength range 300-800 nm. Decrease in transmittance indicates the formation of color-center defects. Values for the energy-band gap, the width of the energy tail above the ...

  11. Magnetic moment of $X_Q$ state with $J^{PC}=1^{+\\pm}$ in light cone QCD sum rules

    CERN Document Server

    Agamaliev, A K; Savcı, M

    2016-01-01

    The magnetic moments of the recently observed resonance $X_b(5568)$ by DO Collaboration and its partner with charm quark are calculated in the framework of the light cone QCD sum rules, by assuming that these resonances are represented as tetra--quark states with quantum numbers $J^{PC}=1^{+\\pm}$. The magnetic moment can play critical role in determination of the quantum numbers, as well as giving useful information about the inner structure of these mesons.

  12. ZnO-PbO-B2O3 glasses as gamma-ray shielding materials

    DEFF Research Database (Denmark)

    Singh, H.; Gerward, Leif; Singh, K.

    2003-01-01

    Values of the gamma-ray mass-attenuation coefficient, the photon mean free path (MFP), the effective atomic number and the effective electron density have been determined experimentally for xZnO.2xPbO.(1-3x)B2O3 (x = 0.1-0.26) glasses at photon energies 511, 662, 1173 and 1332 keV and compared...

  13. The Adsorption of Argon and Oxygen on Silver Mordenite

    Science.gov (United States)

    1990-01-01

    O.ODO ESSB =O.ODO DO I=1,NA PYRT=XA( I) CALL FUNCT (PYRT, XKA, XRA, FUN) ESSA=ESSA+(YA( I)-FUN)**2 ENDDO DO I-1,NB PYRT=XB( I) CALL FUNCT(PYRT,XKB,XRB...FUN) ESSB = ESSB +(YB( I)-FUN)**2 101 ENDDO SIGA=DSQRT(ESSA/(DFLOAT(NA-2))) SIGB=DSQRT( ESSB /(DFLOAT(NB-2))) 99 FORMAT(’ ’) 100 FORMAT(’ The Langmuir

  14. Dilated cardiomyopathy mutation (R134W in mouse cardiac troponin T induces greater contractile deficits against α-myosin heavy chain than against β-myosin heavy chain

    Directory of Open Access Journals (Sweden)

    Sampath K Gollapudi

    2016-10-01

    Full Text Available Many studies have demonstrated that depressed myofilament Ca2+ sensitivity is common to dilated cardiomyopathy (DCM in humans. However, it remains unclear whether a single determinant — such as myofilament Ca2+ sensitivity — is sufficient to characterize all cases of DCM because the severity of disease varies widely with a given mutation. Because dynamic features dominate in the heart muscle, alterations in dynamic contractile parameters may offer better insight on the molecular mechanisms that underlie disparate effects of DCM mutations on cardiac phenotypes. Dynamic features are dominated by myofilament cooperativity that stem from different sources. One such source is the strong tropomyosin binding region in troponin T (TnT, which is known to modulate crossbridge (XB recruitment dynamics in a myosin heavy chain (MHC-dependent manner. Therefore, we hypothesized that the effects of DCM-linked mutations in TnT on contractile dynamics would be differently modulated by α- and β-MHC. After reconstitution with the mouse TnT equivalent (TnTR134W of the human DCM mutation (R131W, we measured dynamic contractile parameters in detergent-skinned cardiac muscle fiber bundles from normal (α-MHC and transgenic mice (β-MHC. TnTR134W significantly attenuated the rate constants of tension redevelopment, XB recruitment dynamics, XB distortion dynamics, and the magnitude of length-mediated XB recruitment only in α-MHC fiber bundles. TnTR134W decreased myofilament Ca2+ sensitivity to a greater extent in α-MHC (0.14 pCa units than in β-MHC fiber bundles (0.08 pCa units. Thus, our data demonstrate that TnTR134W induces a more severe DCM-like contractile phenotype against α-MHC than against β-MHC background.

  15. Evolution of gluon TMDs from small to moderate x

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, Andrey [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    Recently we obtained an evolution equation of gluon TMDs, which addresses a problem of unification of different kinematic regimes. It describes evolution in the whole range of Bjorken $x_B$ and the whole range of transverse momentum $k_\\perp$. In this notes I study different limits of this evolution equation and show how it yields several well-known and some previously unknown results.

  16. Coherent Structures and Chaos Control in High-Power Microwave and Charged-Particle Beam Devices

    Science.gov (United States)

    2009-01-31

    the electron sheath. The equilibrium How velocity Vbj is determined by adding a small velocity \\Vhj from the averaged flow velocity, 0.04 b e0...direction at the electron cloud layer x- the vane lip x=b and f)SE,.L 12R dx =/i+0 2i. aSEv dx =/i-0 •<• %) EQUI c-(o)-k Vbj ) SEvk (x = h). (6

  17. Degree of Conversion and BisGMA, TEGDMA, UDMA Elution from Flowable Bulk Fill Composites

    Science.gov (United States)

    Lempel, Edina; Czibulya, Zsuzsanna; Kovács, Bálint; Szalma, József; Tóth, Ákos; Kunsági-Máté, Sándor; Varga, Zoltán; Böddi, Katalin

    2016-01-01

    The degree of conversion (DC) and the released bisphenol A diglycidyl ether dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) monomers of bulk-fill composites compared to that of conventional flowable ones were assessed using micro-Raman spectroscopy and high performance liquid chromatography (HPLC). Four millimeter-thick samples were prepared from SureFil SDR Flow (SDR), X-tra Base (XB), Filtek Bulk Fill (FBF) and two and four millimeter samples from Filtek Ultimate Flow (FUF). They were measured with micro-Raman spectroscopy to determine the DC% of the top and the bottom surfaces. The amount of released monomers in 75% ethanol extraction media was measured with HPLC. The differences between the top and bottom DC% were significant for each material. The mean DC values were in the following order for the bottom surfaces: SDR_4mm_20s > FUF_2mm_20s > XB_4mm_20s > FBF_4mm_20s > XB_4mm_10s > FBF_4mm_10s > FUF_4mm_20s. The highest rate in the amount of released BisGMA and TEGDMA was found from the 4 mm-thick conventional flowable FUF. Among bulk-fills, FBF showed a twenty times higher amount of eluted UDMA and twice more BisGMA; meanwhile, SDR released a significantly higher amount of TEGDMA. SDR bulk-fill showed significantly higher DC%; meanwhile XB, FBF did not reach the same level DC, as that of the 2 mm-thick conventional composite at the bottom surface. Conventional flowable composites showed a higher rate of monomer elution compared to the bulk-fills, except FBF, which showed a high amount of UDMA release. PMID:27213361

  18. Degree of Conversion and BisGMA, TEGDMA, UDMA Elution from Flowable Bulk Fill Composites

    Directory of Open Access Journals (Sweden)

    Edina Lempel

    2016-05-01

    Full Text Available The degree of conversion (DC and the released bisphenol A diglycidyl ether dimethacrylate (BisGMA, triethylene glycol dimethacrylate (TEGDMA and urethane dimethacrylate (UDMA monomers of bulk-fill composites compared to that of conventional flowable ones were assessed using micro-Raman spectroscopy and high performance liquid chromatography (HPLC. Four millimeter-thick samples were prepared from SureFil SDR Flow (SDR, X-tra Base (XB, Filtek Bulk Fill (FBF and two and four millimeter samples from Filtek Ultimate Flow (FUF. They were measured with micro-Raman spectroscopy to determine the DC% of the top and the bottom surfaces. The amount of released monomers in 75% ethanol extraction media was measured with HPLC. The differences between the top and bottom DC% were significant for each material. The mean DC values were in the following order for the bottom surfaces: SDR_4mm_20s > FUF_2mm_20s > XB_4mm_20s > FBF_4mm_20s > XB_4mm_10s > FBF_4mm_10s > FUF_4mm_20s. The highest rate in the amount of released BisGMA and TEGDMA was found from the 4 mm-thick conventional flowable FUF. Among bulk-fills, FBF showed a twenty times higher amount of eluted UDMA and twice more BisGMA; meanwhile, SDR released a significantly higher amount of TEGDMA. SDR bulk-fill showed significantly higher DC%; meanwhile XB, FBF did not reach the same level DC, as that of the 2 mm-thick conventional composite at the bottom surface. Conventional flowable composites showed a higher rate of monomer elution compared to the bulk-fills, except FBF, which showed a high amount of UDMA release.

  19. Drug: D07801 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available A ALIMENTARY TRACT AND METABOLISM A01 STOMATOLOGICAL PREPARATIONS A01A STOMATOLOGICAL PREPARATION...xamethasone phenylpropionate D DERMATOLOGICALS D07 CORTICOSTEROIDS, DERMATOLOGICAL PREPARATIONS D07A CORTICO... combinations D07XB05 Dexamethasone D07801 Dexamethasone phenylpropionate D10 ANTI-ACNE PREPARATION...S D10A ANTI-ACNE PREPARATIONS FOR TOPICAL USE D10AA Corticosteroids, combinations for trea...tment of acne D10AA03 Dexamethasone D07801 Dexamethasone phenylpropionate H SYSTEMIC HORMONAL PREPARATIONS,

  20. GenBank blastx search result: AK104788 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104788 001-039-E04 U35369.1 Enterococcus faecalis vancomycin resistance genes, response regulator (van...RB), protein histidine kinase (vanSB), D,D-carboxypeptidase (vanYB), putative D-2-hydroxyacid dehydrogenase (van...HB), D-Ala:D-Lac ligase (vanB), and putative D,D-dipeptidase (vanXB) genes, complete cds.|BCT BCT 3e-20 +2 ...

  1. GenBank blastx search result: AK111921 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111921 001-013-A10 U35369.1 Enterococcus faecalis vancomycin resistance genes, response regulator (van...RB), protein histidine kinase (vanSB), D,D-carboxypeptidase (vanYB), putative D-2-hydroxyacid dehydrogenase (van...HB), D-Ala:D-Lac ligase (vanB), and putative D,D-dipeptidase (vanXB) genes, complete cds.|BCT BCT 7e-11 +1 ...

  2. Studies of antimicrobial activities of some 4-thiazolidinone fused pyrimidines, [1,5]-benzodiazepines and their oxygen substituted hydroxylamine derivatives

    Directory of Open Access Journals (Sweden)

    Singh Bhawani

    2010-01-01

    Full Text Available Thiazolidin-4-one fused pyrimidines, [1,5]-benzodiazepines and their oxygen substituted hydroxylamine derivatives have been screened for antibacterial, antifungal and antimalarial activity. Bacillus subtilis, Escherichia coli, Proteus mirabilis and Salmonella typhi were used for antibacterial screening. Aspergillus fumigatus and Candida albicans were used for antifungal screening and Plasmodium species were used for antimalarial screening. The antibacterial and antifungal activities are expressed in terms of zone of inhibition and antimalarial activity is expressed in IC 50 value. Fifteen compounds 2Xa, 2Xb, 2Xc, 2Xs, 3IV, 3Va, 3Vc, 3VIIIa, 3VIIIh, 3IXa, 3IXb, 3IXc, 3Xa, 4IXa and 4Xa were tested for antibacterial as well as antifungal activity and seven compounds 2IXb, 2Xb, 3VIIIc, 3Xc, 4IXa, 4Xa and 4IXw were tested for antimalarial activity. Streptomycin, griseofulvin and chloroquine were taken as standard drugs in antibacterial, antifungal and antimalarial activity, respectively. The compound 2Xs was found significant antimicrobial against Bacillus subtilis, E. coli, Aspergillus fumigatus and Candida albicans as well as compound 3Xa was significant antimicrobial against Bacillus subtilis, E. coli, Salmonella typhi, Aspergillus fumigatus and Candida albicans. The compound 2Xb showed significant antimalarial activity.

  3. [Effects of xinshuaikang granule on cardiac function and atrial natriuretic polypeptide levels in rabbits with experimental congestive heart failure].

    Science.gov (United States)

    Jin, X C; Sun, J Z; Wang, X

    1996-07-01

    Xinshuaikang (XSK) granule mainly consisted of Radix Ginseng, Aconifum carmichaeli, Ligustici wallichii, Semen Lepidii seu Descurainiae, etc. Thirty-five white rabbits of Japanese strain with big ears were used and five groups were divided randomly. The models of chronic heart failure (CHF) was made by injection of adriamycin through the marginal vein of rabbit's ear. Only one group without adriamycin injection was taken as blank group. After the making of models, Xinbao (XB) was used to treat one group which was regarded as control group, XSK was used to treat two model groups, one used higher dose, the other one used lower dose. Fifteen days was taken as a course of treatment. The results were: the body weight of all model groups was heavier than that without adriamycin. After a course of treatment, the body weight of the groups treated by XSK or XB decreased rapidly, the general conditions of the three groups were improved; the two drugs could reduce heart rate and enhance heart function, at the same time they reduced the level of atrial natriuretic polypeptide (ANP) in plasma. The best results was obtained in XSK group with higher dose, the effect of XSK group with lower dose was equivalent to that of XB group. Hence, XSK granule could enhance the CHF rabbits' heart function, improve their heart endocrine activity, this drug had a reliable effect on CHF.

  4. Structural and physical properties in the system ZnO-B 2O 3-P 2O 5-R nO m

    Science.gov (United States)

    Li, Shengchun; Chen, Pei; Li, Yaogang

    2010-12-01

    The glass forming region in the quaternary system ZnO-B 2O 3-P 2O 5-R nO m has been determined. Glass transition temperature ( Tg), glass density ( ρ), thermal expansion coefficient ( α) and weight loss percentage ( WL) of these glasses were measured. The structure of (90- x- y)ZnO- xB 2O 3- yP 2O 5-10R nO m glass was characterized by infrared spectra (IR), Raman spectra and X-ray diffraction (XRD). Results of IR and Raman indicated that B 2O 3 participated in the glass network as a glass modifier and the IR band around 1440 cm -1 was ascribed to the v as(B-O-B) vibrations. Glass intensity increased with increase in B 2O 3 content. The disappearance of v s(P-O-P) vibration around 760 cm -1 indicated that P-O-B linkage was formed. XRD results revealed that the major crystalline phase changes with substitution of different amounts of B 2O 3: Zn 2P 2O 7 for 45ZnO- xB 2O 3-35P 2O 5-10R nO m glass, where x=0-20, and BPO 4 for 45ZnO- xB 2O 3-35P 2O 5-10R nO m glass, where x=30-40.

  5. Measurement of Exclusive $\\pi^0$ Electroproduction Structure Functions and their Relationship to Transversity GPDs

    CERN Document Server

    Bedlinskiy, I; Niccolai, S; Stoler, P; Adhikari, K P; Aghasyan, M; Amaryan, M J; Anghinolfi, M; Avakian, H; Baghdasaryan, H; Ball, J; Baltzell, N A; Battaglieri, M; Bennett, R P; Biselli, A S; Bookwalter, C; Boiarinov, S; Briscoe, W J; Brooks, W K; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Contalbrigo, M; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Doughty, D; Dupre, R; Egiyan, H; Alaoui, A El; Fassi, L El; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Fleming, J A; Forest, T A; Garçon, M; Gevorgyan, N; Giovanetti, K L; Girod, F X; Gohn, W; Gothe, R W; Graham, L; Griffioen, K A; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Heddle, D; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jo, H S; Joo, K; Keller, D; Khandaker, M; Khetarpal, P; Kim, A; Kim, W; Klein, F J; Koirala, S; Kubarovsky, A; Kuhn, S E; Kuleshov, S V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, I J D; Mao, Y; Markov, N; Martinez, D; Mayer, M; McKinnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moutarde, H; Munevar, E; Camacho, C Munoz; Nadel-Turonski, P; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L L; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Pereira, S Anefalos; Phelps, E; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Puckett, A J R; Raue, B A; Ricco, G; Rimal, D; Ripani, M; Rosner, G; Rossi, P; Sabatié, F; Saini, M S; Salgado, C; Saylor, N; Schott, D; Schumacher, R A; Seder, E; Seraydaryan, H; Sharabian, Y G; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Strauch, S; Taiuti, M; Tang, W; Taylor, C E; Tian, Ye; Tkachenko, S; Ungaro, M; Vineyard, M F; Vlassov, A; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zachariou, N; Zhang, J; Zhao, Z W; Zonta, I

    2012-01-01

    Exclusive $\\pi^0$ electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in $Q^2$, $x_B$, $t$, and $\\phi_\\pi$, in the $Q^2$ range from 1.0 to 4.6 GeV$^2$,\\ $-t$ up to 2 GeV$^2$, and $x_B$ from 0.1 to 0.58. Structure functions $\\sigma_T +\\epsilon \\sigma_L, \\sigma_{TT}$ and $\\sigma_{LT}$ were extracted as functions of $t$ for each of 17 combinations of $Q^2$ and $x_B$. The data were compared directly with two handbag-based calculations including both longitudinal and transversity GPDs. Inclusion of only longitudinal GPDs very strongly underestimates $\\sigma_T +\\epsilon \\sigma_L$ and fails to account for $\\sigma_{TT}$ and $\\sigma_{LT}$, while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity flip and helicity non-flip processes. The results confirm ...

  6. Measurement of Exclusive $π^0$ Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

    Energy Technology Data Exchange (ETDEWEB)

    Bedlinskiy, Ivan; Niccolai, Silvia; Stoler, Paul; Adhikari, Krishna; Aghasyan, Mher; Amaryan, Moskov; Anghinolfi, Marco; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Ball, Jacques; Baltzell, Nathan; Battaglieri, Marco; Bennett, Robert; Biselli, Angela; Bookwalter, Craig; Boyarinov, Sergey; Briscoe, William; Brooks, Williams; Burkert, Volker; Carman, Daniel; Celentano, Andrea; Chandavar, Shloka; Charles, Gabriel; Contalbrigo, Marco; Crede, Volker; D& #x27; Angelo, Annalisa; Daniel, Aji; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Deur, Alexandre; Djalali, Chaden; Doughty, David; Dupre, Raphael; Egiyan, Hovanes; El Alaoui, Ahmed; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Fegan, Stuart; Fleming, Jamie; Forest, Tony; Garcon, Michel; Gevorgyan, Nerses; Giovanetti, Kevin; Girod, Francoi-Xavier; Gohn, Wesley; Gothe, Ralf; Graham, Lewis; Griffioen, Keith; Guegan, Baptiste; Guidal, Michel; Guo, Lei; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Heddle, David; Hicks, Kenneth; Holtrop, Maurik; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Jo, Hyon-Suk; Joo, Kyungseon; Keller, Dustin; Khanddaker, Mahbubul; Khertarpal, Puneet; Kim, Andrey; Kim, Wooyoung; Klein, Franz; Koirala, Suman; Kubarovsky, A; Kuhn, Sebastian; Kuleshov, Sergey; Kvaltine, Nicholas; Livingston, Kenneth; Lu, Haiyun; MacGregor, Ian; Mao, Yuqing; Markov, Nikolai; Martinez, D; Mayer, Michael; McKinnon, Bryan; Meyer, Curtis; Mineeva, Taisiya; Mirazita, Marco; Mokeev, Viktor; Moutarde, Herve; Munevar Espitia, Edwin; Munoz Camacho, Carlos; Nadel-Turonski, Pawel; Niculescu, Gabriel; Niculescu, Maria-Ioana; Osipenko, Mikhail; Ostrovidov, Alexander; Pappalardo, Luciano; Permuzyan, Rafayel; Park, Kijun; Park, Sungkyun; Pasyuk, Eugene; Pereira, Sergio; Phelps, Evan; Pisano, Silvia; Pogorelko, Oleg; Pozdnyakov, Sergey; Price, John; Procureur, Sebastien; Prok, Yelena; Protopopescu, Dan; Puckett, Andrew; Raue, Brian; Ricco, Giovanni; Rimal, Dipak; Ripani, Marco; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Saini, Mukesh; Salgado, Carlos; Saylor, Nicholas; Schott, Diane; Schumacher, Reinhard; Seder, Erin; Seraydaryan, Heghine; Sharabian, Youri; Smith, Gregory; Sober, Daniel; Sokhan, Daria; Stepanyan, Samuel; Strauch, Steffen; Taiuti, Mauro; Tang, Wei; Taylor, Charles; Tian, Ye; Tkachenko, Svyatoslav; Ungaro, Maurizio; Vineyard, Michael; Vlasov, Alexander; Voskanyan, Hakob; Voutier, Eric; Walford, Natalie; Watts, Daniel; Weinstein, Lawrence; Weygan, Dennis; Wood, Michael; Zachariou, Nicholas; Zhang, Jixie; Zhao, Zhiwen

    2012-09-01

    Exclusive $\\pi^0$ electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in $Q^2$, $x_B$, $t$, and $\\phi_\\pi$, in the $Q^2$ range from 1.0 to 4.6 GeV$^2$,\\ $-t$ up to 2 GeV$^2$, and $x_B$ from 0.1 to 0.58. Structure functions $\\sigma_T +\\epsilon \\sigma_L, \\sigma_{TT}$ and $\\sigma_{LT}$ were extracted as functions of $t$ for each of 17 combinations of $Q^2$ and $x_B$. The data were compared directly with two handbag-based calculations including both longitudinal and transversity GPDs. Inclusion of only longitudinal GPDs very strongly underestimates $\\sigma_T +\\epsilon \\sigma_L$ and fails to account for $\\sigma_{TT}$ and $\\sigma_{LT}$, while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity flip and helicity non-flip processes. The results confirm that exclusive $\\pi^0$ electroproduction offers direct experimental access to the transversity GPDs.

  7. Precision astrometry of pulsars and other compact radio sources in the globular cluster M15

    Science.gov (United States)

    Kirsten, Franz; Vlemmings, Wouter; Freire, Paulo; Kramer, Michael; Rottmann, Helge; Campbell, Robert M.

    2014-05-01

    The globular cluster (GC) M15 (NGC 7078) is host to at least eight pulsars and two low mass X-ray binaries (LMXBs), one of which is also visible in the radio regime. Here we present the results of a multi-epoch global very long baseline interferometry (VLBI) campaign aiming at i) measuring the proper motion of the known compact radio sources; ii) finding and classifying thus far undetected compact radio sources in the GC; and iii) detecting a signature of the putative intermediate mass black hole (IMBH) proposed to reside at the core of M15. We measure the sky motion in right ascension (μα) and declination (μδ) of the pulsars M15A and M15C and of the LMXB AC211 to be (μα,μδ)M15A = (-0.54 ± 0.14, -4.33 ± 0.25) mas yr-1, (μα,μδ)M15C = (-0.75 ± 0.09, -3.52 ± 0.13) mas yr-1, and (μα,μδ)AC211 = (-0.46 ± 0.08, - 4.31 ± 0.20) mas yr-1, respectively. Based on these measurements we estimate the global proper motion of M15 to be (μα,μδ) = (-0.58 ± 0.18, -4.05 ± 0.34) mas yr-1. We detect two previously known but unclassified compact sources within our field of view. Our observations indicate that one them is of extragalactic origin while the other one is a foreground source, quite likely an LMXB. The double neutron star system M15C became fainter during the observations, disappeared for one year and is now observable again - an effect possibly caused by geodetic precession. The LMXB AC211 shows a double lobed structure in one of the observations indicative of an outburst during this campaign. With the inclusion of the last two of a total of seven observations we confirm the upper mass limit for a putative IMBH to be M•< 500 M⊙.

  8. A New Evolutionary Picture for CVs and LMXBs

    CERN Document Server

    King, A R; King, Andrew R.; Schenker, Klaus

    2001-01-01

    We consider an alternative to the standard picture of CV and LMXB evolution, namely the idea that most CVs (and by extension LMXBs) may not yet have had time to evolve to their theoretical minimum orbital periods. We call this the Binary Age Postulate (BAP). The observed short-period cutoff in the CV histogram emerges naturally as the shortest period yet reached in the age of the Galaxy, while the post-minimum-period space density problem is removed. The idea has similar desirable consequences for LMXBs. In both cases systems with nuclear-evolved secondary stars form a prominent part of the short-period distributions. Properties such as the existence and nature of ultrashort-period systems, and the spread in mass transfer rates at a given orbital period, are naturally reproduced.

  9. Low-Mass X-ray Binaries and Globular Clusters in Centaurus A

    CERN Document Server

    Jordan, Andres; McLaughlin, Dean E; Blakeslee, John P; Evans, Daniel A; Kraft, Ralph P; Hardcastle, Martin J; Peng, Eric W; Cote, Patrick; Croston, Judith H; Juett, Adrienne M; Minniti, Dante; Raychaudhury, Somak; Sarazin, Craig L; Worrall, Diana M; Harris, William E; Woodley, Kristin A; Birkinshaw, Mark; Brassington, Nicola J; Forman, William R; Jones, Christine; Murray, Stephen S

    2007-01-01

    We present results of Hubble Space Telescope and Chandra X-ray Observatory observations of globular clusters (GCs) and low-mass X-ray binaries (LMXBs) in the central regions of Centaurus A. Out of 440 GC candidates we find that 41 host X-ray point sources that are most likely LMXBs. We fit King models to our GC candidates in order to measure their structural parameters. We find that GCs that host LMXBs are denser and more compact, and have higher encounter rates and concentrations than the GC population as a whole. We show that the higher concentrations and masses are a consequence of the dependence of LMXB incidence on central density and size plus the general trend for denser GCs to have higher masses and concentrations. We conclude that neither concentration nor mass are fundamental variables in determining the presence of LMXBs in GCs, and that the more fundamental parameters relate to central density and size.

  10. X-ray Observations of Neutron Star Binaries Evidence for Millisecond Spins

    CERN Document Server

    Strohmayer, T E

    2001-01-01

    High amplitude X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries (LMXB), a long sought goal of X-ray astronomy. I briefly review the status of our knowledge of these oscillations. So far 10 neutron star systems have been observed to produce burst oscillations, interestingly, the observed frequencies cluster in a fairly narrow range from about 300 - 600 Hz, well below the break-up frequency for most modern neutron star equations of state (EOS). This has led to suggestions that their spin frequencies may be limited by the loss of angular momentum due to gravitational wave emission. Connections with gravity wave rotational instabilities will be briefly described.

  11. Modeling the Spin Equilibrium of Neutron Stars in LMXBs Without Gravitational Radiation

    Science.gov (United States)

    Andersson, N.; Glampedakis, K.; Haskell, B.; Watts, A. L.

    2004-01-01

    In this paper we discuss the spin-equilibrium of accreting neutron stars in LMXBs. We demonstrate that, when combined with a naive spin-up torque, the observed data leads to inferred magnetic fields which are at variance with those of galactic millisecond radiopulsars. This indicates the need for either additional spin-down torques (eg. gravitational radiation) or an improved accretion model. We show that a simple consistent accretion model can be arrived at by accounting for radiation pressure in rapidly accreting systems (above a few percent of the Eddington accretion rate). In our model the inner disk region is thick and significantly sub-Keplerian, and the estimated equilibrium periods are such that the LMXB neutron stars have properties that accord well with the galactic millisecond radiopulsar sample. The implications for future gravitational-wave observations are also discussed briefly.

  12. K2 and MAXI observations of Sco X-1 - Evidence for disc precession?

    CERN Document Server

    Hakala, Pasi; Barclay, Thomas; Charles, Phil

    2015-01-01

    Sco X-1 is the archetypal low mass X-ray binary (LMXB) and the brightest persistent extra-solar X-ray source in the sky. It was included in the K2 Campaign 2 field and was observed continuously for 71 days with 1 minute time resolution. In this paper we report these results and underline the potential of K2 for similar observations of other accreting compact binaries. We reconfirm that Sco X-1 shows a bimodal distribution of optical "high" and "low" states and rapid transitions between them on timescales less than 3 hours (or 0.15 orbits). We also find evidence that this behaviour has a typical systemic timescale of 4.8 days, which we interpret as a possible disc precession period in the system. Finally, we confirm the complex optical vs. X-ray correlation/anticorrelation behaviour for "high" and "low" optical states respectively.

  13. The quasi-periodic oscillations and very low frequency noise of Scorpius X-1 as transient chaos - A dripping handrail?

    Science.gov (United States)

    Scargle, Jeffrey D.; Steiman-Cameron, Thomas; Young, Karl; Donoho, David L.; Crutchfield, James P.; Imamura, James

    1993-01-01

    We present evidence that the quasi-periodic oscillations (QPO) and very low frequency noise (VLFN) characteristic of many accretion sources are different aspects of the same physical process. We analyzed a long, high time resolution EXOSAT observation of the low-mass X-ray binary (LMXB) Sco X-1. The X-ray luminosity varies stochastically on time scales from milliseconds to hours. The nature of this variability - as quantified with both power spectrum analysis and a new wavelet technique, the scalegram - agrees well with the dripping handrail accretion model, a simple dynamical system which exhibits transient chaos. In this model both the QPO and VLFN are produced by radiation from blobs with a wide size distribution, resulting from accretion and subsequent diffusion of hot gas, the density of which is limited by an unspecified instability to lie below a threshold.

  14. Evolution of Hard X-Ray Spectra Along the Branches in Cir X-1

    CERN Document Server

    Ding, G Q; Li, T P

    2003-01-01

    Using the data from the PCA and HEXTE on board the RXTE satellite, we investigate the evolution of the 3-200 keV spectra of the peculiar low mass X-ray binary (LMXB) Cir X-1 along the branches on its hardness-intensity diagram (HID) from the vertical horizontal branch (VHB), through the horizontal horizontal branch (HHB) and normal branch (NB), to the flaring branch (FB). We detect a power-law hard component in the spectra. It is found that the derived photon indices ($\\Gamma$) of the power-law hard component are correlated with the position on the HID. The power-law component dominates the X-ray emission of Cir X-1 in the energy band higher than $\\sim 20$ keV. The fluxes of the power-law component are compared with those of the bremsstrahlung component in the spectra. A possible origin of the power-law hard component is discussed.

  15. The ongoing outbursts of Aql X-1 and Ginga 1843+009 as seen with INTEGRAL/IBIS-ISGRI

    DEFF Research Database (Denmark)

    Rodriguez, J.; Chenevez, Jérôme; Hannikainen, D.

    2009-01-01

    Our INTEGRAL monitoring campaign of GRS 1915+105 allows the Aquila region of the sky to be nicely covered with the IBIS telescope. During our last observation, on March 18, 2009 (11h-16h45 UTC), both the LMXB Aql X-1 was clearly detected with the ISGRI camera at 17.5 sigma, 8.6 sigma, 6.6 sigma...... a cut-off in any of its forms (highecut*po or cutoffpl), or replacing the simple model by thermal Comptonization (comptt) does not improve the fit. This clearly shows the absence of any cut-off in the energy range considered for the fit. We remark that the spectral parameters are compatible with those...

  16. The low-mass X-ray binary-millisecond radio pulsar birthrate problem revisited

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We investigate the birthrate problem for low-mass X-ray binaries(LMXBs) and millisecond radio pulsars(MRPs) in this paper.We consider intermediate-mass and low-mass X-ray binaries(I/LMXBs) to be the progenitors of MRPs,and calculate their evolutionary response to the cosmic star formation rate(SFR) both semi-analytically and numerically.With a typical value(1 Gyr) of the LMXB lifetime,one may expect comparable birthrates of LMXBs and MRPs,but the calculated number of LMXBs is an order of magnitude higher than that observed in the Galaxy.Instead,we suggest that the birthrate problem could be solved if most MRPs have evolved from faint to rather than bright LMXBs.The former may have a population of-104 in the Galaxy.

  17. Do Black Hole Candidates Have Magnetic Moments Instead of Event Horizons?

    CERN Document Server

    Robertson, S L; Robertson, Stanley L.; Leiter, Darryl J.

    2003-01-01

    In previous work we found that many of the spectral properties of low mass x-ray binaries (LMXB), including galactic black hole candiates (GBHC) were consistent with the existence of intrinsically magnetized central objects. We review and extend these findings and show that the existence of intrisically magnetic BHC is consistent with a new class of solutions of the Einstein field equations of General Relativity. These solutions are based on a strict adherence to the Strong Principle of Equivalence (SPOE) requirement that the world lines of physical matter must remain timelike in all regions of spacetime. The new solutions emerge when the structure and radiation transfer properties of the energy momentum tensor on the right hand side of the Einstein field equations are appropriately chosen to dynamically enforce the SPOE requirement of timelike world line completeness. In this context, we find that the Einstein field equations allow the existence of highly red shifted, Magnetospheric, Eternally Collapsing Obj...

  18. On the connection between accreting X-ray and radio millisecond pulsars

    CERN Document Server

    Tauris, T M

    2012-01-01

    For many years it has been recognized that the terminal stages of mass transfer in a low-mass X-ray binary (LMXB) should cause the magnetosphere of the accreting neutron star to expand, leading to a braking torque acting on the spinning pulsar. After the discovery of radio millisecond pulsars (MSPs) it was therefore somewhat a paradox (e.g. Ruderman et al. 1989) how these pulsars could retain their fast spins following the Roche-lobe decoupling phase, RLDP. Here I present a solution to this so-called "turn-off problem" which was recently found by combining binary stellar evolution models with torque computations (Tauris 2012). The solution is that during the RLDP the spin equilibrium of the pulsar is broken and therefore it remains a fast spinning object. I briefly discuss these findings in view of the two observed spin distributions in the populations of accreting X-ray millisecond pulsars (AXMSPs) and radio MSPs.

  19. Bowen fluorescence from companion stars in x-ray Binaries

    Directory of Open Access Journals (Sweden)

    J. Casares

    2004-01-01

    Full Text Available Este art culo examina una nueva t ecnica para detectar estrellas compa~neras en los LMXB y las transitorias de rayos X durante la transferencia de masa utilizando las l neas NIII uorescentes de Bowen en 4634-4640. Estas l neas se reprocesan muy e cientemente en las atm osferas de las estrellas compa~neras proporcionando estimaciones de las velocidades K2 y funciones de masas. Este m etodo se aplic o a Sco X-1, X 822-371 y GB339-4 el cual, en este ultimo caso, proporciona una evidencia din amica de la presencia de un agujero negro acreciente. Tambi en se presentan resultados preliminares de una campa~na VLT sobre V801 Ara, V926 Sco y XTE J1814-338.

  20. X-Ray Binary Populations in a Cosmological Context, Including NuSTAR Predictions

    Science.gov (United States)

    Cardiff, Ann Hornschemeier

    2011-01-01

    The new ultradeep 4 Ms Chandra Deep Field South has afforded the deepest view ever of X-ray binary populations. We report on the latest results on both LMXB and HMXB evolution out to redshifts of approximately four, including comparison with the latest theoretical models, using this deepest-ever view of the X-ray universe with Chandra. The upcoming NuSTAR mission will open up X-ray binary populations in the hard X-ray band, similar to the pioneering work of Fabbiano et al. in the Einstein era. We report on plans to study both Local Group and starburst galaxies as well as the implications those observations may have for X-ray binary populations in galaxies contributing to the Cosmic X-ray Background.

  1. Magnetic two-photon scattering and two-photon emission - Cross sections and redistribution functions

    Science.gov (United States)

    Alexander, S. G.; Meszaros, P.

    1991-01-01

    The magnetic two-photon scattering cross section is discussed within the framework of QED, and the corresponding scattering redistribution function for this process and its inverse, as well as the scattering source function are calculated explicitly. In a similar way, the magnetic two-photon emission process which follows the radiative excitation of Landau levels above ground is calculated. The two-photon scattering and two-photon emission are of the same order as the single-photon magnetic scattering. All three of these processes, and in optically thick cases also their inverses, are included in radiative transport calculations modeling accreting pulsars and gamma-ray bursters. These processes play a prominent role in determining the relative strength of the first two cyclotron harmonics, and their effects extend also to the higher harmonics.

  2. The Thermal Evolution following a Superburst on an Accreting Neutron Star

    CERN Document Server

    Cumming, A; Cumming, Andrew; Macbeth, Jared

    2004-01-01

    Superbursts are very energetic Type I X-ray bursts discovered in recent years by long term monitoring of X-ray bursters, and believed to be due to unstable ignition of carbon in the deep ocean of the neutron star. In this Letter, we follow the thermal evolution of the surface layers as they cool following the burst. The resulting lightcurves agree very well with observations for layer masses and energy releases in the range expected from ignition calculations. At late times, the cooling flux from the layer decays as a power law in time, giving timescales for quenching of normal Type I bursting of weeks, in good agreement with observational limits. We show that simultaneous modelling of superburst lightcurves and quenching times promises to constrain both the thickness of the fuel layer and the energy deposited.

  3. Stability of strange stars (SS) derived from a realistic equation of state

    CERN Document Server

    Sinha, M N; Dey, M; Ray, S; Bhowmick, S; Sinha, Monika; Dey, Jishnu; Dey, Mira; Ray, Subharthi; Bhowmick, Siddhartha

    2002-01-01

    A realistic equation of state (EOS) leads to realistic strange stars (ReSS) which are compact in the mass radius plot, close to the Schwarzchild limiting line (Dey et al 1998). Many of the observed stars fit in with this kind of compactness, irrespective of whether they are X-ray pulsars, bursters or soft $\\gamma$ repeaters or even radio pulsars. We point out that a change in the radius of a star can be small or large, when its mass is increasing and this depends on the position of a particular star on the mass radius curve. We carry out a stability analysis against radial oscillations and compare with the EOS of other strange star (SS) models. We find that the ReSS is stable and an M-R region can be identified to that effect.

  4. Strange Stars with Realistic Quark Vector Interaction and Phenomenological Density-dependent Scalar Potential

    CERN Document Server

    Dey, M; Dey, J; Ray, S; Samanta, B C; Dey, Mira; Bombaci, Ignazio; Dey, Jishnu; Ray, Subharthi

    1998-01-01

    We derive an equation of state (EOS) for strange matter, starting from an interquark potential which (i) has asymptotic freedom built into it, (ii) shows confinement at zero density ($\\rho_B = 0$) and deconfinement at high $\\rho_B$, and (iii) gives a stable configuration for chargeless, $\\beta$-stable quark matter. This EOS is then used to calculate the structure of Strange Stars, and in particular their mass-radius relation. Our present results confirm and reinforce the recent claim\\cite{li,b} that the compact objects associated with the x-ray pulsar Her X-1, and with the x-ray burster 4U 1820-30 are strange stars.

  5. Incompressibility of strange matter

    CERN Document Server

    Sinha, M N; Dey, J; Dey, M; Ray, S; Bhowmick, S; Sinha, Monika; Bagchi, Manjari; Dey, Jishnu; Dey, Mira; Ray, Subharthi; Bhowmick, Siddhartha

    2002-01-01

    Strange stars calculated from a realistic equation of state (EOS) show compact objects in the mass radius curve, when they are solved for gravitational fields via TOV equation. Many of the observed stars seem to fit in with this kind of compactness irrespective of whether they are X-ray pulsars, bursters or soft $\\gamma$ repeaters or radio pulsars. Calculated incompressibility of this strange matter shows continuity with that of nuclear matter. This is important in the cosmic separation of phase scenario. We compare our calculations of incompressibility with that of a nuclear matter EOS. This EOS has a continuous transition to ud-matter at about five times normal density. From a look at the consequent velocity of sound it is found that the transition to ud-matter seems necessary.

  6. Comparison between Windowed FFT and Hilbert-Huang Transform for Analyzing Time Series with Poissonian Fluctuations: A Case Study

    Institute of Scientific and Technical Information of China (English)

    Dong Han; Shuang-Nan Zhang

    2006-01-01

    Hilbert-Huang Transform (HHT) is a novel data analysis technique for nonlinear and non-stationary data. We present a time-frequency analysis of both simulated light curves and an X-ray burst from the X-ray burster 4U 1702-429 with both the HHT and the Windowed Fast Fourier Transform (WFFT) methods. Our results show that the HHT method has failed in all cases for light curves with Poissonian fluctuations which are typical for all photon counting instruments used in astronomy, whereas the WFFT method can sensitively detect the periodic signals in the presence of Poissonian fluctuations; the only drawback of the WFFT method is that it cannot detect sharp frequency variations accurately.

  7. Observations of Type i X-Ray Bursts from GS 1826-238 with RXTE

    Science.gov (United States)

    Lewin, Walter

    Type I X-ray bursts are the result of thermonuclear flashes on the surface of accreting neutron stars. The spectral lines which are expected in the X-ray spectra of the bursts will allow for a direct measurement of the gravitational redshift from the surface of the neutron stars (one of the holy grails in physics). XMM-Newton has the potential of detecting such lines. We have been awarded 200 ksec observations with XMM-Newton of the X-ray burster GS 1826-238. During this time we expect to observe ten X-ray bursts and to accumulate about 40,000 high-spectral resolution burst counts with the RGS, and roughly 2 Mcounts with EPIC-PN. We are requesting simultaneous observations with RXTE to obtain essential information about the underlying continuum spectrum.

  8. Light Curves for Rapidly-Rotating Neutron Stars

    CERN Document Server

    Cadeau, C; Leahy, D; Campbell, S S; Cadeau, Coire; Morsink, Sharon M.; Leahy, Denis; Campbell, Sheldon S.

    2006-01-01

    We present raytracing computations for light emitted from the surface of a rapidly-rotating neutron star in order to construct light curves for X-ray pulsars and bursters. These calculations are for realistic models of rapidly-rotating neutron stars which take into account both the correct exterior metric and the oblate shape of the star. We find that the most important effect arising from rotation comes from the oblate shape of the rotating star. We find that approximating a rotating neutron star as a sphere introduces serious errors in fitted values of the star's radius and mass if the rotation rate is very large. However, in most cases acceptable fits to the ratio M/R can be obtained with the spherical approximation.

  9. Dynamics Analysis and Transition Mechanism of Bursting Calcium Oscillations in Non-Excitable Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; LU Qi-Shao; DUAN Li-Xia

    2007-01-01

    A one-pool model with Ca2+-activated inositol-trisphosphate-concentration degradation is considered.For complex bursting Ca2+ oscillation,point-cycle bursting of subHopf-subHopf type is found to be in the intermediate state from quasi-periodic bursting to Point-point bursting of subHopf-subHopf type.The fast-slow burster analysis is used to study the transition mechanisms among simple periodic oscillation,quasi-periodic bursting,point-point and point-cycle burstings.The dynamics analysis of different oscillations provides better insight into the generation and transition mechanisms of complex intra- and inter-cellular Ca2+signalling.

  10. The Homunculus: a Unique Astrophysical Laboratory

    Science.gov (United States)

    Gull, T. R.; Nielsen, K. E.

    η Car is surrounded by bipolar shells, the Homunculus and the internal Little Homunculus, that are observed in both emission and absorption. Thin disks, located between the bipolar lobes, include the very bright Weigelt blobs and the neutral emission structure called the Strontium filament. All are affected by changes in UV and X-Ray flux of the binary system. For example, the normally ionized Little Homunculus recombines during the few month long spectroscopic minimum and then reionizes. Spectral data, obtained with Hubble Space Telescope Space Telescope Imaging Spectrograph (HST/STIS) and with Very Large Telescope UltraViolet Echelle Spectrograph (VLT/UVES), provide a wealth of information on spectroscopic properties of neutral and singly-ionized metals and on chemistry of nitrogen rich, carbon, oxygen poor, dense, warm gas. This information is important to understand gamma ray bursters (GRB) that reveal red-shifted near-UV metallic absorptions from pre-GRB stellar ejecta.

  11. Larval biometry of Simulium rubrithorax (Diptera: Simuliidae and size comparison between populations in the states of Minas Gerais and Roraima, Brazil

    Directory of Open Access Journals (Sweden)

    Alvan-Aguilar Miriam Adriana

    2003-01-01

    Full Text Available The number of larval instars of Simulium (Hemicnetha rubrithorax Lutz (Diptera: Nematocera was determined using the lateral length of the head capsule. In this study 1,035 larvae, of different sizes, were measured (639 from the state of Roraima and 396 from the state of Minas Gerais. A frequency distribution analysis was carried out on the measurements of the lateral length of the head capsule to determine the number of larval instars. The limits of each instar were defined by the lower frequency of the measurements falling in a range of values, by the presence of the "egg burster" that characterizes the first larval instar, and by the developmental stage of the gill histoblast. The determination of the instar number was tested using a Student's t-test (p 0.05 were observed between them.

  12. Far-field dispersal modeling for fuel-air-explosive devices

    Energy Technology Data Exchange (ETDEWEB)

    Glass, M.W.

    1990-05-01

    A computer model for simulating the explosive dispersal of a fuel agent in the far-field regime is described and is applied to a wide variety of initial conditions to judge their effect upon the resulting fuel/air cloud. This work was directed toward modeling the dispersal process associated with Fuel-Air-Explosives devices. The far-field dispersal regime is taken to be that time after the initial burster charge detonation in which the shock forces no longer dominate the flow field and initial canister and fuel mass breakup has occurred. The model was applied to a low vapor pressure fuel, a high vapor pressure fuel and a solid fuel. A strong dependence of the final cloud characteristics upon the initial droplet size distribution was demonstrated. The predicted fuel-air clouds were highly non-uniform in concentration. 18 refs., 86 figs., 4 tabs.

  13. Cataclysmic variables and related objects; Proceedings of the Seventy-second Colloquium, Haifa, Israel, August 9-13, 1982

    Science.gov (United States)

    Livio, M.; Shaviv, G.

    The periods of cataclysmic variable stars are considered along with photometric and spectroscopic observations of the cataclysmic variable AC Cancri, recent spectroscopy of X-ray sources and systems related to cataclysmic variables, orbital solutions for WZ Sagittae during quiescence, spectra of symbiotic stars, and the formation of optical CNO emission lines in cataclysmic variables. Attention is given to infrared spectra of nova dust shells, evolutionary models for SNI progenitor stars, the physical conditions inside white dwarfs and type I supernovae, the energy distribution of hard X-ray emitting cataclysmic variables, time dependence in accretion onto magnetic white dwarfs, polarized radiation from AM Herculis stars, and radio emission and synchronization. Other topics discussed are related to X-ray emission from cataclysmic variables, mass loss associated with X-ray bursts of neutron stars, and fast oscillations in variable X-ray sources and X-ray bursters. For individual items see A84-35927 to A84-35954

  14. The mass transfer rate in X1916-053 - It is driven by gravitational radiation?

    Science.gov (United States)

    Swank, J. H.; Taam, R. E.; White, N. E.

    1985-01-01

    A 50-minute period for a binary system harboring an X-ray burster would allow several alternatives for the mass-giving secondary, including an H-shell burning-plus-He degenerate core composite model. The burst properties of X1916-053 are presently used to argue against the He degenerate as well as the He main sequence solutions and to estimate whether, for any of the other solutions, the mass transfer rate could be consistent with that expected from gravitational radiation (GR). Within an uncertainty of a factor of 2, the transfer rate for the composite model solution is consistent with gravitational radiation, but enhancement by other mechanisms should be investigated.

  15. The influence of accretion rate and metallicity on thermonuclear bursts: predictions from KEPLER models

    CERN Document Server

    Lampe, Nathanael; Galloway, Duncan K

    2015-01-01

    Using the KEPLER hydrodynamics code, 464 models of thermonuclear X-ray bursters were performed across a range of accretion rates and compositions. We present the library of simulated burst profiles from this sample, and examine variations in the simulated lightcurve for different model conditions. We find that the recurrence time varies as a power law against accretion rate, and measure its slope while mixed H/He burning is occurring for a range of metallicities, finding the power law gradient to vary from $\\eta = 1.1$ to $1.24$. We also identify the accretion rates at which mixed H/He burning stops and a transition occurs to different burning regimes. We also explore how varying the accretion rate and metallicity affects burst morphology in both the rise and tail.

  16. Bursting Ca2+ Oscillations and Synchronization in Coupled Cells

    Institute of Scientific and Technical Information of China (English)

    JI Quan-Bao; LU Qi-Shao; Yang Zhuo-Qin; Duan Li-Xia

    2008-01-01

    A mathematical model proposed by Grubelnk et al. [Biophys. Chem. 94 (2001) 59] is employed to study the physiological role of mitochondria and the cytosolic proteins in generating complex Ca2+ oscillations. Intracellular bursting calcium oscillations of point-point, point cycle and two-folded limit cycle types are observed and explanations are given based on the fast/slow dynamical analysis, especially for point-cycle and two-folded limit cycle types, which have not been reported before. Furthermore, synchronization of coupled bursters of Ca2+oscillations via gap junctions and the effect of bursting types on synchronization of coupled cells are studied. It is argued that bursting oscillations of point-point type may be superior to achieve synchronization than that of point-cycle type.

  17. Relativistic astrophysics - The view from Texas in Baltimore /Review/

    Science.gov (United States)

    Trimble, V. L.; Maran, S. P.

    1981-01-01

    Recent observational and theoretical work presented at the Tenth Texas Symposium on Relativistic Astrophysics held in Baltimore, Maryland from December 15-19, 1980, is outlined. Areas covered include the theoretical foundations of relativistic astrophysics in general relativity, quantum gravitational theory and the association of grand unification with astronomical and cosmological issues, the cosmic microwave, X-ray, gamma-ray, UV, cosmic ray and gravitational wave backgrounds, the current expansion rate and average mass-energy density of the universe, and mechanisms of galaxy formation. Also discussed are the characteristics of active galaxies and clusters emitting in the gamma-ray and X-ray regions, and compact objects formed from supernova explosions, including pulsars, X-ray-emitting neutron stars, Sco X-1 and SS 433, gamma-ray sources, and X-ray and gamma-ray bursters.

  18. SMM hard X-ray observations of the soft gamma-ray repeater 1806-20

    Science.gov (United States)

    Kouveliotou, C.; Norris, J. P.; Cline, T. L.; Dennis, B. R.; Desai, U. D.; Orwig, L. E.

    1987-01-01

    Six bursts from the soft gamma-ray repeater (SGR) 1806-20 have been recorded with the SMM Hard X-ray Burst Spectrometer during a highly active phase in 1983. Rise and decay times of less than 5 ns have been detected. Time profiles of these events indicate low-level emission prior to and after the main peaks. The results suggest that SGRs are distinguished from classical gamma-ray bursts by repetition, softer nonvarying spectra, short durations, simple temporal profiles, and a tendency for source locations to correlate with Population I objects. SGR characteristics differ from those of type I X-ray bursts, but they appear to have similarities with the type II bursts from the Rapid Burster.

  19. Gamma-ray burst afterglow theory

    CERN Document Server

    van Eerten, Hendrik

    2013-01-01

    It is by now fairly well established that gamma-ray burst afterglows result from initially relativistic outflows interacting with the medium surrounding the burster and emitting non-thermal radiation ranging from radio to X-rays. However, beyond that, many big and small questions remain about afterglows, with the accumulating amount of observational data at the various frequencies raising as many questions as they answer. In this review I highlight a number of current theoretical issues and how they fit or do not fit within our basic theoretical framework. In addition to theoretical progress I will also emphasize the increasing role and usefulness of numerical studies of afterglow blast waves and their radiation.

  20. Compression and model reduction: A case study

    Energy Technology Data Exchange (ETDEWEB)

    LoFaro, T. [Washington State Univ., Pullman, WA (United States); Kopell, N. [Boston Univ., Boston, MA (United States)

    1995-12-31

    We discuss a method by which the dynamics of a network of coupled neurons can be captured in a one-dimensional map. The network used as an example of this technique consists of a pair of neurons, one of which is an endogenous burster and the other excitable, but not bursting in the absence of phasic input. The reduction is accomplished by decomposing the flow into fast and slow subsystems, each operating on a distinct time scale. A {open_quotes}map of knees{close_quotes} is constructed using singular perturbation techniques. A concise expression for this map is developed by introducing time coordinates to each stable branch of the slow manifold. The compression associated with the fast subsystem is used to determine the qualitative properties of the map.

  1. INTEGRAL reports renewed activity from KS 1741-293

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Kuulkers, E.; Alfonso-Garzón, J.;

    2010-01-01

    The low-mass X-ray binary and burster source KS 1741-293 has been detected during recent INTEGRAL Galactic bulge (see ATel #438) observations by the JEM-X instrument. On February 25, 2010, between UTC 13:04 and 14:08, KS 1741-293 was detected at a 3-10 keV flux of 9 +/- 4 mCrab, and an upper limi...... in the same energy bands. The region will be observed again by INTEGRAL on March 10, and the regular INTEGRAL monitoring of the Galactic bulge will continue until April 17, 2010. We encourage follow-up observations of this source at all wavelengths....

  2. Electron-scale shear instabilities: magnetic field generation and particle acceleration in astrophysical jets

    CERN Document Server

    Alves, E P; Fonseca, R A; Silva, L O

    2014-01-01

    Strong shear flow regions found in astrophysical jets are shown to be important dissipation regions, where the shear flow kinetic energy is converted into electric and magnetic field energy via shear instabilities. The emergence of these self-consistent fields make shear flows significant sites for radiation emission and particle acceleration. We focus on electron-scale instabilities, namely the collisionless, unmagnetized Kelvin-Helmholtz instability (KHI) and a large-scale dc magnetic field generation mechanism on the electron scales. We show that these processes are important candidates to generate magnetic fields in the presence of strong velocity shears, which may naturally originate in energetic matter outburst of active galactic nuclei and gamma-ray bursters. We show that the KHI is robust to density jumps between shearing flows, thus operating in various scenarios with different density contrasts. Multidimensional particle-in-cell (PIC) simulations of the KHI, performed with OSIRIS, reveal the emergen...

  3. A Hard X-Ray Power-law Spectral Cutoff in Centaurus X-4

    Science.gov (United States)

    Chakrabarty, Deepto; Tomsick, John A.; Grefenstette, Brian W.; Psaltis, Dimitrios; Bachetti, Matteo; Barret, Didier; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Fürst, Felix; Hailey, Charles J.; Harrison, Fiona A.; Kaspi, Victoria M.; Miller, Jon M.; Nowak, Michael A.; Rana, Vikram; Stern, Daniel; Wik, Daniel R.; Wilms, Jörn; Zhang, William W.

    2014-12-01

    The low-mass X-ray binary (LMXB) Cen X-4 is the brightest and closest (law tail of unknown origin. We report here on a simultaneous observation of Cen X-4 with NuSTAR (3-79 keV) and XMM-Newton (0.3-10 keV) in 2013 January, providing the first sensitive hard X-ray spectrum of a quiescent neutron star transient. The 0.3-79 keV luminosity was 1.1× 1033 D^2_kpc erg s-1, with sime60% in the thermal component. We clearly detect a cutoff of the hard spectral tail above 10 keV, the first time such a feature has been detected in this source class. We show that thermal Comptonization and synchrotron shock origins for the hard X-ray emission are ruled out on physical grounds. However, the hard X-ray spectrum is well fit by a thermal bremsstrahlung model with kTe = 18 keV, which can be understood as arising either in a hot layer above the neutron star atmosphere or in a radiatively inefficient accretion flow. The power-law cutoff energy may be set by the degree of Compton cooling of the bremsstrahlung electrons by thermal seed photons from the neutron star surface. Lower thermal luminosities should lead to higher (possibly undetectable) cutoff energies. We compare Cen X-4's behavior with PSR J1023+0038, IGR J18245-2452, and XSS J12270-4859, which have shown transitions between LMXB and radio pulsar modes at a similar X-ray luminosity.

  4. The nature of the island and banana states in atoll sources and a unified model for low-mass X-ray binaries

    Science.gov (United States)

    Church, M. J.; Gibiec, A.; Bałucińska-Church, M.

    2014-03-01

    We propose an explanation of the island and banana states and the relation between atoll and Z-track sources, constituting a unified model for low-mass X-ray binaries (LMXB). We find a dramatic transition at a luminosity of 1-2 × 1037 erg s-1 above which the high-energy cut-off ECO of the Comptonized emission in all sources is low at a few keV. There is thermal equilibrium between the neutron star at ˜2 keV and the Comptonizing accretion disc corona (ADC) causing the low ECO in the banana state of atolls and all states of the Z-track sources. Below this luminosity, ECO increases towards 100 keV causing the hardness of the island state. Thermal equilibrium is lost, the ADC becoming much hotter than the neutron star via an additional coronal heating mechanism. This suggests a unified model of LMXB: the banana state is a basic state with the mass accretion rate dot{M} increasing, corresponding to the normal branch of Z-track sources. The island state has high ADC temperature, this state not existing in the Z-sources with luminosities much greater than the critical value. The Z-track sources have an additional flaring branch consistent with unstable nuclear burning on the neutron star at high dot{M}. This burning regime does not exist at low dot{M} so this branch is not seen in atolls (except GX atolls). The horizontal branch in Z-track sources has a strong increase in radiation pressure disrupting the inner disc and launching relativistic jets.

  5. THE X-RAY LUMINOSITY FUNCTION OF LOW MASS X-RAY BINARIES IN EARLY-TYPE GALAXIES, THEIR METAL-RICH, AND METAL-POOR GLOBULAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, Mark B.; Zepf, Stephen E., E-mail: mpeacock@msu.edu [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

    2016-02-10

    We present the X-ray luminosity function (XLF) of low-mass X-ray binaries (LMXBs) in the globular clusters (GCs) and fields of seven early-type galaxies. These galaxies are selected to have both deep Chandra observations, which allow their LMXB populations to be observed to X-ray luminosities of 10{sup 37}–10{sup 38} erg s{sup −1}, and Hubble Space Telescope optical mosaics that enable the X-ray sources to be separated into field LMXBs, GC LMXBs, and contaminating background and foreground sources. We find that at all luminosities the number of field LMXBs per stellar mass is similar in these galaxies. This suggests that the field LMXB populations in these galaxies are not effected by the GC specific frequency, and that properties such as binary fraction and the stellar initial mass function are either similar across the sample or change in a way that does not affect the number of LMXBs. We compare the XLF of the field LMXBs to that of the GC LMXBs and find that they are significantly different with a p-value of 3 × 10{sup −6} (equivalent to 4.7σ for a normal distribution). The difference is such that the XLF of the GC LMXBs is flatter than that of the field LMXBs, with the GCs hosting relatively more bright sources and fewer faint sources. A comparison of the XLF of the metal-rich and metal-poor GCs hints that the metal-poor clusters may have more bright LMXBs, but the difference is not statistically significant.

  6. A HARD X-RAY POWER-LAW SPECTRAL CUTOFF IN CENTAURUS X-4

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, Deepto; Nowak, Michael A. [MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Tomsick, John A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Grefenstette, Brian W.; Fürst, Felix; Harrison, Fiona A.; Rana, Vikram [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Psaltis, Dimitrios [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Bachetti, Matteo; Barret, Didier [Observatoire Midi-Pyrénées, Université de Toulouse III - Paul Sabatier, F-31400 Toulouse (France); Christensen, Finn E. [Division of Astrophysics, National Space Institute, Technical University of Denmark, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Kaspi, Victoria M. [Department of Physics, McGill University, Montreal, PQ H3A 2T8 (Canada); Miller, Jon M. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Wik, Daniel R.; Zhang, William W. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Wilms, Jörn, E-mail: deepto@mit.edu [Dr. Karl-Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Universität Erlangen-Nürnberg, D-96049 Bamberg (Germany)

    2014-12-20

    The low-mass X-ray binary (LMXB) Cen X-4 is the brightest and closest (<1.2 kpc) quiescent neutron star transient. Previous 0.5-10 keV X-ray observations of Cen X-4 in quiescence identified two spectral components: soft thermal emission from the neutron star atmosphere and a hard power-law tail of unknown origin. We report here on a simultaneous observation of Cen X-4 with NuSTAR (3-79 keV) and XMM-Newton (0.3-10 keV) in 2013 January, providing the first sensitive hard X-ray spectrum of a quiescent neutron star transient. The 0.3-79 keV luminosity was 1.1×10{sup 33} D{sub kpc}{sup 2} erg s{sup –1}, with ≅60% in the thermal component. We clearly detect a cutoff of the hard spectral tail above 10 keV, the first time such a feature has been detected in this source class. We show that thermal Comptonization and synchrotron shock origins for the hard X-ray emission are ruled out on physical grounds. However, the hard X-ray spectrum is well fit by a thermal bremsstrahlung model with kT{sub e} = 18 keV, which can be understood as arising either in a hot layer above the neutron star atmosphere or in a radiatively inefficient accretion flow. The power-law cutoff energy may be set by the degree of Compton cooling of the bremsstrahlung electrons by thermal seed photons from the neutron star surface. Lower thermal luminosities should lead to higher (possibly undetectable) cutoff energies. We compare Cen X-4's behavior with PSR J1023+0038, IGR J18245–2452, and XSS J12270–4859, which have shown transitions between LMXB and radio pulsar modes at a similar X-ray luminosity.

  7. QTL Mapping for Hull Thickness and Related Traits in Hybrid Rice Xieyou 9308

    Institute of Scientific and Technical Information of China (English)

    LUO Li-li; ZHANG Ying-xin; CHEN Dai-bo; ZHAN Xiao-deng; SHEN Xi-hong; CHENG Shi-hua; CAO Li-yong

    2014-01-01

    We conducted a quantitative trait locus (QTL) analysis of 165 rice recombinant inbred lines derived from a cross between Zhonghui 9308 (Z9308) and Xieqingzao B (XB) in Hainan and Hangzhou, China. Grain thickness (GT), brown rice thickness (BRT), hull thickness (HT) and milling quality were used for QTL mapping. HT was significantly and positively correlated with GT and BRT. Twenty-nine QTLs were detected with phenotypic effects ranging from 2.80% to 21.27%. Six QTLs, qGT3, qBRT3, qBRT4, qHT6.1, qHT8 and qHT11, were detected repeatedly across two environments. Inherited from XB, qHT6.1, qHT8 and qHT11 showed stable expression, explaining 9.92%, 21.27% and 10.83% of the phenotypic variances in Hainan and 9.61%, 6.40%and 6.71%in Hangzhou, respectively. Additionally, the QTL cluster between RM5944 and RM5626 on chromosome 3 was probably responsible for GT and milling quality. The cluster between RM6992 and RM6473 on chromosome 4 played an important role in grain filling. Three near isogenic lines (NILs), X345, X338 and X389, were selected because they contained homozygous fragments from Zhonghui 9308, corresponding to qHT6.1, qHT8 and qHT11, respectively. The hull of XB was thicker than those of X345, X338 and X389. In all the lines, qHT6.1, qHT8 and qHT11 that regulated rice HT were stably inherited with obvious genetic effects.

  8. Syntheses and surprising regioselectivity of 5- and 6-substituted decaboranyl ethers via the nucleophilic attack of alcohols on 6- and 5-halodecaboranes.

    Science.gov (United States)

    Ewing, William C; Carroll, Patrick J; Sneddon, Larry G

    2011-05-02

    The selective syntheses of new classes of decaboranyl ethers containing a range of functional groups substituted at the B5 or B6 positions were achieved through the reaction of alcohols with halodecaboranes. The surprising regioselectivity of the reaction, where the reaction of the 6-halodecaboranes (6-X-B(10)H(13)) with alcohols yielded the 5-substituted decaboranyl ethers (5-RO-B(10)H(13)) and the reaction with 5-halodecaboranes (5-X-B(10)H(13)) gave the 6-substituted decaboranyl ethers (6-RO-B(10)H(13)), was confirmed by NMR and X-ray crystallographic analyses. The crystallographic determinations also showed that the decaboranyl ethers had shortened B-O bonds and apparent sp(2) hybridization at oxygen indicating significant π-backbonding from oxygen to the cage boron. A possible substitution mechanism was computationally identified involving: (1) initial nucleophilic attack by the alcohol-oxygen at a site adjacent to the 5- or 6-halo-substituted boron, (2) movement of the terminal hydrogen at the point of attack to a bridging position, (3) formation of a 5-membered (B-O-H-Cl-B) cyclic transition state allowing the acidic methanolic-hydrogen to bond to the halogen, (4) release of HX, and finally (5) movement of a bridging hydrogen into the vacated terminal position. Deuterium labeling studies confirmed the movement of hydrogen from a bridging position of the halodecaborane into the halogen-vacated terminal position on the decaboranyl ether product. The relative reaction rates of the 6-X-B(10)H(13) compounds (X = F, Cl, Br, I) with alcohols were likewise found to be consistent with this mechanism.

  9. SU-E-T-802: Verification of Implanted Cardiac Pacemaker Doses in Intensity-Modulated Radiation Therapy: Dose Prediction Accuracy and Reduction Effect of a Lead Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J [Dept. of Radiation Oncology, Konkuk University Medical Center, Seoul (Korea, Republic of); Chung, J [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2015-06-15

    Purpose: To verify delivered doses on the implanted cardiac pacemaker, predicted doses with and without dose reduction method were verified using the MOSFET detectors in terms of beam delivery and dose calculation techniques in intensity-modulated radiation therapy (IMRT). Methods: The pacemaker doses for a patient with a tongue cancer were predicted according to the beam delivery methods [step-and-shoot (SS) and sliding window (SW)], intensity levels for dose optimization, and dose calculation algorithms. Dosimetric effects on the pacemaker were calculated three dose engines: pencil-beam convolution (PBC), analytical anisotropic algorithm (AAA), and Acuros-XB. A lead shield of 2 mm thickness was designed for minimizing irradiated doses to the pacemaker. Dose variations affected by the heterogeneous material properties of the pacemaker and effectiveness of the lead shield were predicted by the Acuros-XB. Dose prediction accuracy and the feasibility of the dose reduction strategy were verified based on the measured skin doses right above the pacemaker using mosfet detectors during the radiation treatment. Results: The Acuros-XB showed underestimated skin doses and overestimated doses by the lead-shield effect, even though the lower dose disagreement was observed. It led to improved dose prediction with higher intensity level of dose optimization in IMRT. The dedicated tertiary lead sheet effectively achieved reduction of pacemaker dose up to 60%. Conclusion: The current SS technique could deliver lower scattered doses than recommendation criteria, however, use of the lead sheet contributed to reduce scattered doses.Thin lead plate can be a useful tertiary shielder and it could not acuse malfunction or electrical damage of the implanted pacemaker in IMRT. It is required to estimate more accurate scattered doses of the patient with medical device to design proper dose reduction strategy.

  10. Pendekatan Regresi Berganda Pada Analisis Varians Klasifikasi Dua Arah

    OpenAIRE

    Syahputri, Erni

    2011-01-01

    The procedurs for multiple regression to obtained a solution b = (XT X)-1 (XT Y), of the normal equation XT Xb = (XT Y), it is necessary that XT X be a nonsingular mattrix. All this means in practise is that the normal equations must involve as many independent equations as there are parameters to be estimated. If data are obtaned from a designed experiment, however, some case is needed to check that all the normal equations are independent, or if they are not, take steps to obtained stimat...

  11. Spectrophotometric determination of Mercury (II by simultaneous micelle mediated extraction through ternary complex formation in water samples

    Directory of Open Access Journals (Sweden)

    Farzin Nekouei

    2014-06-01

    Full Text Available In this study, a micelle mediated extraction procedure for preconcentration of trace quantities of Hg(II as a prior step to its simultaneous spectrophotometric determination has been developed. The method is based on a ternary ion-association of Hg(II, Xylidyl Blue (XB and cationic surfactant (CTAB. Major factors affecting the efficiency of the method has been studied. The limit of detection (LOD under optimum conditions based on 3Sb was 4.65 ng mL-1. The proposed method has been applied for determination of trace amount of mercury in water samples with satisfactory results.

  12. Target mass corrections for spin-dependent structure functions in collinear factorization

    CERN Document Server

    Accardi, A

    2008-01-01

    We derive target mass corrections (TMC) for the spin-dependent nucleon structure function g1 and polarization asymmetry A1 in collinear factorization at leading twist. The TMCs are found to be significant for g1 at large xB, even at relatively high Q^2 values, but largely cancel in A1. A comparison of TMCs obtained from collinear factorization and from the operator product expansion shows that at low Q^2 the corrections drive the proton A1 in opposite directions.

  13. 转动你的音乐——三星X818

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    自音乐手机大行其道以来,各大手机厂商就不断寻找着质量更高、操作更简洁的音乐播放方式,而三星的XB18以独特的Jog Key音乐播放转盘这个独门利器,在手机和音乐播放器之间找到了一个完美的平衡点。

  14. DLC地狱

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    2月1日,由XB360限时独占的《使命召唤:黑暗行动》首个DLC地图——“First Strike”在XBOX LIVE卖场放出下载,售价为1200点MSP。这个DLC由四张对人对战地图和一张僵尸地图组成。分别是Berlin Wall,Discovery,Kowloon,Stadium和Ascension。

  15. -Irradiation effect on the acoustical properties of zinc lead borate glasses

    Science.gov (United States)

    Sharma, G.; Singh, K.; Manupriya; Klare, H. S.; Rajendran, V.; Gayathri Devi, A. V.; Narang, S. B.

    2005-11-01

    The effect of -irradiation on the acoustical properties of xZnO.2xPbO.(1-3x)B2O3 glasses has been studied. Ultrasonic velocity and attenuation measurements have been made before and after -irradiation at room temperature in the frequency range 2.25-10 MHz. From the measured density and ultrasonic velocity data, the elastic moduli, Poisson's ratio and other parameters have been obtained. Changes in the acoustical properties are explained in terms of radiation-induced structural defects and the influence of PbO/ZnO in the glass network structure.

  16. Deeply Virtual Compton Scattering off the neutron

    CERN Document Server

    Mazouz, M; Ferdi, C; Gavalian, G; Kuchina, E; Amarian, M; Aniol, K A; Beaumel, M; Benaoum, H; Bertin, P; Brossard, M; Chen, J P; Chudakov, E; Craver, B; Cusanno, F; De Jager, C W; Deur, A; Feuerbach, R; Fieschi, J M; Frullani, S; Garçon, M; Garibaldi, F; Gayou, O; Gilman, R; Gómez, J; Gueye, P; Guichon, P A M; Guillon, B; Hansen, O; Hayes, D; Higinbotham, D; Holmstrom, T; Hyde, C E; Ibrahim, H; Igarashi, R; Jiang, X; Jo, H S; Kaufman, L J; Kelleher, A; Kolarkar, A; Kumbartzki, G; Laveissière, G; Le Rose, J J; Lindgren, R; Liyanage, N; Lu, H J; Margaziotis, D J; Meziani, Z E; McCormick, K; Michaels, R; Michel, B; Moffit, B; Monaghan, P; Nanda, S; Nelyubin, V; Potokar, M; Qiang, Y; Ransome, R D; Real, J S; Reitz, B; Roblin, Y; Roche, J; Sabatie, F; Saha, A; Sirca, S; Slifer, K; Solvignon, P; Subedi, R; Sulkosky, V; Ulmer, P E; Voutier, E; Wang, K; Weinstein, L B; Wojtsekhowski, B; Zheng, X; Zhu, L

    2007-01-01

    The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\\vec e},e'\\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.

  17. Deeply Virtual Compton Scattering off the neutron

    Energy Technology Data Exchange (ETDEWEB)

    M. Mazouz; A. Camsonne; C. Munoz Camacho; C. Ferdi; G. Gavalian; E. Kuchina; M. Amarian; K. A. Aniol; M. Beaumel; H. Benaoum; P. Bertin; M. Brossard; J.-P. Chen; E. Chudakov; B. Craver; F. Cusanno; C.W. de Jager; A. Deur; R. Feuerbach; J.-M. Fieschi; S. Frullani; M. Garcon; F. Garibaldi; O. Gayou; R. Gilman; J. Gomez; P. Gueye; P.A.M. Guichon; B. Guillon; O. Hansen; D. Hayes; D. Higinbotham; T. Holmstrom; C.E. Hyde; H. Ibrahim; R. Igarashi; X. Jiang; H.S. Jo; L.J. Kaufman; A. Kelleher; A. Kolarkar; G. Kumbartzki; G. Laveissiere; J.J. LeRose; R. Lindgren; N. Liyanage; H.-J. Lu; D.J. Margaziotis; Z.-E. Meziani; K. McCormick; R. Michaels; B. Michel; B. Moffit; P. Monaghan; S. Nanda; V. Nelyubin; M. Potokar; Y. Qiang; R.D. Ransome; J.-S. Real; B. Reitz; Y. Roblin; J. Roche; F. Sabatie; A. Saha; S. Sirca; K. Slifer; P. Solvignon; R. Subedi; V. Sulkosky; P.E. Ulmer; E. Voutier; K. Wang; L.B. Weinstein; B. Wojtsekhowski; X. Zheng; L. Zhu

    2007-12-01

    The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\\vec e},e'\\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.

  18. SU-E-T-91: Accuracy of Dose Calculation Algorithms for Patients Undergoing Stereotactic Ablative Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tajaldeen, A [RMIT university, Docklands, Vic (Australia); Ramachandran, P [Peter MacCallum Cancer Centre, Bendigo (Australia); Geso, M [RMIT University, Bundoora, Melbourne (Australia)

    2015-06-15

    Purpose: The purpose of this study was to investigate and quantify the variation in dose distributions in small field lung cancer radiotherapy using seven different dose calculation algorithms. Methods: The study was performed in 21 lung cancer patients who underwent Stereotactic Ablative Body Radiotherapy (SABR). Two different methods (i) Same dose coverage to the target volume (named as same dose method) (ii) Same monitor units in all algorithms (named as same monitor units) were used for studying the performance of seven different dose calculation algorithms in XiO and Eclipse treatment planning systems. The seven dose calculation algorithms include Superposition, Fast superposition, Fast Fourier Transform ( FFT) Convolution, Clarkson, Anisotropic Analytic Algorithm (AAA), Acurous XB and pencil beam (PB) algorithms. Prior to this, a phantom study was performed to assess the accuracy of these algorithms. Superposition algorithm was used as a reference algorithm in this study. The treatment plans were compared using different dosimetric parameters including conformity, heterogeneity and dose fall off index. In addition to this, the dose to critical structures like lungs, heart, oesophagus and spinal cord were also studied. Statistical analysis was performed using Prism software. Results: The mean±stdev with conformity index for Superposition, Fast superposition, Clarkson and FFT convolution algorithms were 1.29±0.13, 1.31±0.16, 2.2±0.7 and 2.17±0.59 respectively whereas for AAA, pencil beam and Acurous XB were 1.4±0.27, 1.66±0.27 and 1.35±0.24 respectively. Conclusion: Our study showed significant variations among the seven different algorithms. Superposition and AcurosXB algorithms showed similar values for most of the dosimetric parameters. Clarkson, FFT convolution and pencil beam algorithms showed large differences as compared to superposition algorithms. Based on our study, we recommend Superposition and AcurosXB algorithms as the first choice of

  19. Analysis of emission of Eu3+ and Dy3+ doped Magnesium Boro-Tellurite (MBT) ceramics

    OpenAIRE

    2015-01-01

    Rare earth (RE) ions play an important role in the improvement of the optical properties of ceramics. Rare-earth ceramics are commonly used in display panels, fluorescent lamps and lasers. The luminescence properties of Magnesium Boro-Tellurite (MBT) Eu3+ and Dy3+ doped ceramics have not been reported before. Therefore, the aim of this paper is to determine the effect of different compositions on the luminescence properties of the MBT material. A series of xTeO2-(70-x)B2O3-30MgO ceramics with...

  20. Dependence of the emission electric dipole line strength of Eu~(3+) on the composition of lead borate glasses

    Institute of Scientific and Technical Information of China (English)

    江莎; 刘子怡; 夹国华; 段昌奎

    2009-01-01

    Lead borate glasses xB2O3+(99-x)PbO+0.5Eu2O3(x=70,60,...,10) were prepared by melt-quenching method.The luminescent properties were characterized with excitation and emission spectra.The emission intensities for 5D0-7FJ(J=0-4) were analyzed to give variation of the relative electric dipole line strengths with the composition of glasses so as to examine the crucial implicit assumption of independent electric dipole line strength on the composition of glass in the Phys.Rev.Lett.2003,91,203903 paper studying l...

  1. Apical Scaffolding Protein NHERF2 Modulates the Localization of Alternatively Spliced Plasma Membrane Ca2+ Pump 2B Variants in Polarized Epithelial Cells*

    OpenAIRE

    Padányi, Rita; Xiong, Yuning; Antalffy, Géza; Lór, Krisztina; Pászty, Katalin; STREHLER, EMANUEL E.; Enyedi, Ágnes

    2010-01-01

    The membrane localization of the plasma membrane Ca2+-ATPase isoform 2 (PMCA2) in polarized cells is determined by alternative splicing; the PMCA2w/b splice variant shows apical localization, whereas the PMCA2z/b and PMCA2x/b variants are mostly basolateral. We previously reported that PMCA2b interacts with the PDZ protein Na+/H+ exchanger regulatory factor 2 (NHERF2), but the role of this interaction for the specific membrane localization of PMCA2 is not known. Here we show that co-expressio...

  2. Effects of configurational disorder on the elastic properties of icosahedral boron-rich alloys based on B6O, B13C2, and B4C, and their mixing thermodynamics

    Science.gov (United States)

    Ektarawong, A.; Simak, S. I.; Hultman, L.; Birch, J.; Tasnádi, F.; Wang, F.; Alling, B.

    2016-04-01

    The elastic properties of alloys between boron suboxide (B6O) and boron carbide (B13C2), denoted by (B6O)1-x(B13C2)x, as well as boron carbide with variable carbon content, ranging from B13C2 to B4C are calculated from first-principles. Furthermore, the mixing thermodynamics of (B6O)1-x(B13C2)x is studied. A superatom-special quasirandom structure approach is used for modeling different atomic configurations, in which effects of configurational disorder between the carbide and suboxide structural units, as well as between boron and carbon atoms within the units, are taken into account. Elastic properties calculations demonstrate that configurational disorder in B13C2, where a part of the C atoms in the CBC chains substitute for B atoms in the B12 icosahedra, drastically increase the Young's and shear modulus, as compared to an atomically ordered state, B12(CBC). These calculated elastic moduli of the disordered state are in excellent agreement with experiments. Configurational disorder between boron and carbon can also explain the experimentally observed almost constant elastic moduli of boron carbide as the carbon content is changed from B4C to B13C2. The elastic moduli of the (B6O)1-x(B13C2)x system are also practically unchanged with composition if boron-carbon disorder is taken into account. By investigating the mixing thermodynamics of the alloys, in which the Gibbs free energy is determined within the mean-field approximation for the configurational entropy, we outline the pseudo-binary phase diagram of (B6O)1-x(B13C2)x. The phase diagram reveals the existence of a miscibility gap at all temperatures up to the melting point. Also, the coexistence of B6O-rich as well as ordered or disordered B13C2-rich domains in the material prepared through equilibrium routes is predicted.

  3. EST Table: BP179437 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available BP179437 ovS302G04f 10/09/28 87 %/140 aa ref|NP_001106136.1| Annexin IX isoform B [...Bombyx mori] dbj|BAA92810.1| annexin IX-B [Bombyx mori] 10/08/29 68 %/138 aa FBpp0119685|DanaGF16493-PA 10/0...XB9 10/09/10 59 %/138 aa gnl|Amel|GB16448-PA 10/09/10 67 %/140 aa gi|91092420|ref|XP_967931.1| PREDICTED: similar to Annexin IX CG5730-PC [Tribolium castaneum] NM_001043376 ovS3 ...

  4. Heavy Exotic Molecules

    CERN Document Server

    Liu, Yizhuang

    2016-01-01

    We briefly review the formation of pion-mediated heavy-light exotic molecules with both charm and bottom, under the general strictures of chiral and heavy quark symmetries. The charm isosinglet exotic molecules with $J^{PC}=1^{++}$ binds, which we identify as the reported neutral $X(3872)$. The bottom isotriplet exotic with $J^{PC}=1^{+-}$ binds, and is identified as a mixed state of the reported charged exotics $Z^+_b(10610)$ and $Z^+_b(10650)$. The bound bottom isosinglet molecule with $J^{PC}=1^{++}$ is a possible neutral $X_b(10532)$ to be observed.

  5. Analogs of LDL Receptor Ligand Motifs in Dengue Envelope and Capsid Proteins as Potential Codes for Cell Entry

    OpenAIRE

    Juan Guevara; Jaime Romo; Troy McWhorter; Natalia Valentinova Guevara

    2015-01-01

    It is established that cell entry of low density lipoprotein particles (LLPs) containing Apo B100 and Apo E is mediated by receptors and GAGs. Receptor ligand motifs, XBBBXXBX, XBBXBX, and ΨBΨXB, and mono- and bipartite NLS sequences are abundant in Apo E and Apo B100 as well as in envelope and capsid proteins of Dengue viruses 1–4 (DENV1–4). Synthetic, fluorescence-labeled peptides of sequences in DENV2 envelope protein, and DENV3 capsid that include these motifs were used to conduct a quali...

  6. Short-term sandbar variability based on video imagery: Comparison between Time-Average and Time-Variance techniques

    Science.gov (United States)

    Guedes, R.M.C.; Calliari, L.J.; Holland, K.T.; Plant, N.G.; Pereira, P.S.; Alves, F.N.A.

    2011-01-01

    Time-exposure intensity (averaged) images are commonly used to locate the nearshore sandbar position (xb), based on the cross-shore locations of maximum pixel intensity (xi) of the bright bands in the images. It is not known, however, how the breaking patterns seen in Variance images (i.e. those created through standard deviation of pixel intensity over time) are related to the sandbar locations. We investigated the suitability of both Time-exposure and Variance images for sandbar detection within a multiple bar system on the southern coast of Brazil, and verified the relation between wave breaking patterns, observed as bands of high intensity in these images and cross-shore profiles of modeled wave energy dissipation (xD). Not only is Time-exposure maximum pixel intensity location (xi-Ti) well related to xb, but also to the maximum pixel intensity location of Variance images (xi-Va), although the latter was typically located 15m offshore of the former. In addition, xi-Va was observed to be better associated with xD even though xi-Ti is commonly assumed as maximum wave energy dissipation. Significant wave height (Hs) and water level (??) were observed to affect the two types of images in a similar way, with an increase in both Hs and ?? resulting in xi shifting offshore. This ??-induced xi variability has an opposite behavior to what is described in the literature, and is likely an indirect effect of higher waves breaking farther offshore during periods of storm surges. Multiple regression models performed on xi, Hs and ?? allowed the reduction of the residual errors between xb and xi, yielding accurate estimates with most residuals less than 10m. Additionally, it was found that the sandbar position was best estimated using xi-Ti (xi-Va) when xb was located shoreward (seaward) of its mean position, for both the first and the second bar. Although it is unknown whether this is an indirect hydrodynamic effect or is indeed related to the morphology, we found that this

  7. Geometric Characteristics of DARPA (Defense Advanced Research Projects Agency) SUBOFF Models (DTRC Model Numbers 5470 and 5471)

    Science.gov (United States)

    1989-03-01

    EQUATION C C C A - 0.3*XX - 1.0 Aa- A**3 A4 - A**4 54 B - 1.2*xx + 1.0 R - CB1 *XX*A4 + CB2 *XX*XX*A3 + 1.0 -A4*B R - PJMJC*(R**CB3) X(I) -XX Y(I) -R GO TO...EMAX - 0.8333333 XB - 3.333333 XM - 10.645833 XA - 13.979167 XC - 14.291667 CBI - 1.126395101 CB2 -0.442874707 C33- 1.0/2.1 Ri! - 0.1175 KO - 10.0 K1

  8. Liver and Biliary System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    9.1 Hepatitis 2006076 Genotype - spcific functional differences of the hepatitis B virus X protein LIN Xu(林旭), et al. Res Center Molec Med, Fujian Med Univ Fuzhou 350004. Chin J Infect Dis 2005 ;23(4) :244 -247. Objective: To investigate the functional differences between the genotype B and C hepatitis B virus X protein (HBx). Methods:The blank control vector pcDNA3. 1/ Hygro( - ) and two recombinant eukaryotic expression vestors, pcDNA3. 1 - XB and pcDNA3. 1 - XC, which

  9. 亿维发布UN CPU224 DC/DC/DC

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    2011年12月.亿维(UniMAT)正式发布了UN CPU224DC/DC/DC.订货号为UN214-1AD23—0XB0。这是一款由亿维研发部根据多年PLC模块的市场经验.历时1年研发出来的200系列自主品牌PLC控制器模块.在兼容西门子PLC功能的前提下,做了部分优化及功能增强。

  10. Drug: D02174 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available RY TRACT AND METABOLISM A01 STOMATOLOGICAL PREPARATIONS A01A STOMATOLOGICAL PREPARATION...ne acetate (JAN/USP) D DERMATOLOGICALS D07 CORTICOSTEROIDS, DERMATOLOGICAL PREPARATIONS D07A CORTICOSTEROIDS...ations D07XB05 Dexamethasone D02174 Dexamethasone acetate (JAN/USP) D10 ANTI-ACNE PREPARATION...S D10A ANTI-ACNE PREPARATIONS FOR TOPICAL USE D10AA Corticosteroids, combinations for treatment ...of acne D10AA03 Dexamethasone D02174 Dexamethasone acetate (JAN/USP) H SYSTEMIC HORMONAL PREPARATIONS, EXCL.

  11. Drug: D02592 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ssification [BR:br08303] A ALIMENTARY TRACT AND METABOLISM A01 STOMATOLOGICAL PREPARATIONS A01A STOMATOLOGICAL PREPARATION...thasone beloxil (USAN) D DERMATOLOGICALS D07 CORTICOSTEROIDS, DERMATOLOGICAL PREPARATIONS D07A CORTICOSTEROI...ately potent, other combinations D07XB05 Dexamethasone D02592 Dexamethasone beloxil (USAN) D10 ANTI-ACNE PREPARATION...S D10A ANTI-ACNE PREPARATIONS FOR TOPICAL USE D10AA Corticosteroids, combinations for treatment of a...cne D10AA03 Dexamethasone D02592 Dexamethasone beloxil (USAN) H SYSTEMIC HORMONAL PREPARATION

  12. Architecture-Level Dependence Analysis for Software Systems

    Science.gov (United States)

    2000-12-01

    3#L%L%&T1!QERO1’ª KJH uW-%+ kC "!$#µ�E:C [·\\b’)!’ +\\ o�pXb’)!Qqo(£J�X8dv¥M¢ ] 2 aR��£�§ ¥ � ���¢�¥¡�¡2��¥Y¨�Ì£ 6¡Z8Ue� �\\¥r¢� � �Ì

  13. Redneck与SolidWorks设计的完美结合

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    为摩托车爱好者手工定制摩托车的Redneck Engineering公司近日采用了SolidWorks 3D CAD软件,SolidWorks是Redneck第一个采用CAD软件产品的公司。Redneck公司老板Doll先生在学会如何使用SolidWorks软件之后,在短短两周内,就完成了轰动一时的摩托车XB Bobber的设计。

  14. Studies of spin-orbit correlations at JLAB

    Energy Technology Data Exchange (ETDEWEB)

    Mher Aghasyan, Harut Avakian

    2011-05-01

    Studies of single spin asymmetries for pion electroproduction in semi-inclusive deep-inelastic scattering are presented using the polarized \\sim6 GeV electrons from at the Thomas Jefferson National Accelerator Facility (JLab) and the Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) with the Inner Calorimeter. The cross section versus the azimuthal angle {\\phi}_h of the produced neutral pion has a substantial sin {\\phi}_h amplitude. The dependence of this amplitude on Bjorken x_B and on the pion transverse momentum is extracted and compared with published data.

  15. GenBank blastx search result: AK104725 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104725 001-038-B08 AF310956.2 Enterococcus faecium response regulator (vanRB2), p...rotein histidine kinase (vanSB2), D,D-carboxypeptidase (vanYB2), VanWB2 (vanWB2), D-2-hydroxyacid dehydrogenase (van...HB2), D-alanine:D-lactate ligase (vanB2), and D,D-dipeptidase (vanXB2) genes, complete cds.|BCT BCT 3e-16 +1 ...

  16. GenBank blastx search result: AK104788 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104788 001-039-E04 AF310956.2 Enterococcus faecium response regulator (vanRB2), p...rotein histidine kinase (vanSB2), D,D-carboxypeptidase (vanYB2), VanWB2 (vanWB2), D-2-hydroxyacid dehydrogenase (van...HB2), D-alanine:D-lactate ligase (vanB2), and D,D-dipeptidase (vanXB2) genes, complete cds.|BCT BCT 5e-22 +2 ...

  17. GenBank blastx search result: AK111921 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111921 001-013-A10 AF310956.2 Enterococcus faecium response regulator (vanRB2), p...rotein histidine kinase (vanSB2), D,D-carboxypeptidase (vanYB2), VanWB2 (vanWB2), D-2-hydroxyacid dehydrogenase (van...HB2), D-alanine:D-lactate ligase (vanB2), and D,D-dipeptidase (vanXB2) genes, complete cds.|BCT BCT 6e-12 +1 ...

  18. Magnetic Exchange Interactions in the Linear Chain Chromium (III) Compounds Catena-Fluorophthalocyaninato chromium (III) and Catena-Cyanophthalocyaninato chromium (III).

    Science.gov (United States)

    2014-09-26

    exchange theory as described by the Hamiltonian N-1 8 = -2J s1" Sj~1i=l is expected to be applicable. Weng 4 has provided the necessary results for...These compounds have a triple chain structure, 9 and a Hamiltonian with nearest neighbor, and next-nearest neighbor exchange is required for a precise...ion is (o- b)2(0*)2(xb)4(oz b) 2, and there are low- lying unoccupied molecular orbitals. The most important LUMO is Xx~y •* Cyano-bridged chains and

  19. Estimation of Genetic Parameters for Reproductive Traits of Fogera and Holstein Friesian Crossbred Cattle at Metekel Ranch, Amhara Region, Ethiopia. Online J. Anim. Feed Res., 6 (4: 90-95.

    Directory of Open Access Journals (Sweden)

    Zeleke. B

    2016-06-01

    Full Text Available The study was carried out at Metekel ranch, Amhara region, Ethiopia, with the objective of estimating genetic parameters for reproductive traits of Fogera and Holstein Friesian crossbreed cattle. The data used in the study included pedigree records and reproductive performance records of animals born from 1990 to 2012.The parameters were estimated by using Variance Component Estimation (VCE 6.0 software. Four models were used Viz. Model1: Y= Xb+Z1a + e; Model2:Y=Xb+Z1a+Z3c + e; Model3: Y=Xb+Z1a+Z2m+ e; cov a,m=0 and Model4: Y= Xb + Z1a + Z2m+ Z3c + e; cov a, m=0.Traits like Gestation Length (GL, Calving Interval (CI and Days Open(DO were estimated using model2 and 4 which fit permanent environmental effect due to repeated records per cow. Whereas, age at first service (AFS and age at first calving (AFC were estimated using model 1, 3, and 4. Estimates of direct heritability of the studied traits ranged from 0.01±0.05 for DO to 0.26±0.21 for AFS, besides high error variance was observed. The phenotypic correlations between traits ranged: 0.33 to 0.99 between CI and DO and GL and DO respectively. And genetic correlations ranged from -1.0 to 1.0 between GL and CI between CI and DO respectively. The result in this study indicates there were low heritability estimates high environmental variances which imply selection based on phenotypic performance of animals was unlikely to bring genetic progress in the studied herd because of the low estimate of heritability of the trait. Besides, The result showed there was moderate to high correlation that indicated selection for one trait will affect the correlated traits. Thus, selection method, in addition to individual records, should incorporate pedigree and progeny information in the form of an index to get optimum genetic progress in the studied population. In addition, selection for any particular trait(s must be carried out with caution as it could have an adverse effect due to correlated response on

  20. Drug: D04221 [KEGG MEDICUS

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  1. Drug: D01367 [KEGG MEDICUS

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  2. Drug: D07073 [KEGG MEDICUS

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  3. Drug: D00385 [KEGG MEDICUS

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  4. Drug: D00983 [KEGG MEDICUS

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  5. Drug: D02591 [KEGG MEDICUS

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  6. Drug: D00975 [KEGG MEDICUS

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  7. Drug: D06216 [KEGG MEDICUS

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    Full Text Available ATOLOGICAL PREPARATIONS A01A STOMATOLOGICAL PREPARATIONS A01AC Corticosteroids for local oral treatment A01A...VASCULAR SYSTEM C05 VASOPROTECTIVES C05A AGENTS FOR TREATMENT OF HEMORRHOIDS AND ANAL FISSURES FOR TOPICAL USE C05AA Corticosteroids...nide sodium phosphate (USAN) D07X CORTICOSTEROIDS, OTHER COMBINATIONS D07XB Corticosteroids, moderately pote...ANTS AND OTHER NASAL PREPARATIONS FOR TOPICAL USE R01AD Corticosteroids R01AD11 T...MOLOGICALS S01B ANTIINFLAMMATORY AGENTS S01BA Corticosteroids, plain S01BA05 Triamcinolone D06216 Triamcinol

  8. Measurements of gross erosion of Al in the DIII-D divertor

    Energy Technology Data Exchange (ETDEWEB)

    Chrobak, C., E-mail: chrobak@fusion.gat.com [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Stangeby, P.C. [University of Toronto Institute for Aerospace Studies, Toronto M3H 5T6 (Canada); Leonard, A.W. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Rudakov, D.L. [University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0417 (United States); Wong, C.P.C. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); McLean, A.G. [Lawrence Livermore National Laboratory, 700 East Ave, Livermore, CA 94550 (United States); Wright, G.M. [Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Buchenauer, D.A.; Watkins, J.G.; Wampler, W.R. [Sandia National Laboratory, P.O. Box 5800, Albuquerque, NM 87185 (United States); Elder, J.D. [University of Toronto Institute for Aerospace Studies, Toronto M3H 5T6 (Canada); Doerner, R.P.; Nishijima, D.; Tynan, G.R. [University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0417 (United States)

    2015-08-15

    Aluminum (Al) is a convenient proxy for beryllium (Be) plasma material interaction studies since they have a number of physical and chemical similarities. Al samples were exposed at the lower outer strike point of an L-mode divertor plasma in DIII-D (conditions 7–11 × 10{sup 18} D-ions cm{sup −2} s{sup −1}, T{sub e} = 12–47 eV). The gross erosion rate was directly measured using post-mortem ion beam analysis of small 1 mm-sized samples where local re-deposition was determined to be negligible. The gross erosion rate was also calculated using spectroscopic methods, but these rates greatly underestimate the direct (i.e. non-spectroscopic) measurement. The direct measured erosion yields were within the range of published D{sup +} → Al ion beam sputtering yields. The ionizations per photon (S/XB) coefficients used in the spectroscopic analysis were determined in separate experiments using He plasmas at the PISCES-B linear plasma facility at UCSD. The measured S/XB coefficients were on average ∼6× higher than the theoretically calculated values.

  9. Deep Exclusive PI0 and ETA Electroproduction with CLAS at Jefferson Lab

    Science.gov (United States)

    Stoler, Paul

    2012-03-01

    The CLAS collaboration at Jefferson Lab has undertaken a series of measurements of exclusive 0̂ and η electroproduction at a beam energy 6 GeV over a large kinematic coverage in Q^2, t and xB. New results of extracted structure functions σL+σT, σLT and σTT, are presented in the kinematic range Q^2 from 1.2 to 3.2 GeV^2/c^2, |t| from |tmin| to 1.2 GeV^2/c^2 and xB from 0.1 to 0.6. Recent theoretical work [1,2] indicate that pseudoscalar meson production is uniquely sensitive to quark helicity-flip processes. The new results, together with CLAS measurements of beam spin asymmetries Aφ [3] and cross section ratios σ(π0)/σ(η) , compared with theoretical calculations [1,2] that are based on the helicity-flip transversity GPDs, provide supporting evidence that pseudoscalar meson production at these kinematics may be dominated by the handbag mechanism and helicity-flip transversity GPDs. [4pt] [1] S.V.Goloskokov and P.Kroll, Eur.Phys.J. A47,112 (2011).[0pt] [2] G.R. Goldstein,J.O.Gonzalez and S.Liuti, Phys. Rev., D84,034007(2011).[0pt] [3] R.DeMasi,et,al.(CLAS Collaboration),Phys.Rev.,C77,042201(2008)

  10. Population Synthesis for Symbiotic X-ray Binaries

    CERN Document Server

    Lu, G -L; Postnov, K A; Yungelson, L R; Kuranov, A G; Wang, N

    2012-01-01

    Symbiotic X-ray binaries (SyXBs) comprise a rare class of low-mass X-ray binaries. We study the Galactic SyXBs, which we consider as detached binaries composed of low-mass giants and wind-fed neutron star companions, by simulation of the interaction of a magnetized neutron star (NS) with its environment and utilizing a population synthesis code. We focus mainly on the parameters that influence observational appearance of the SyXB: the donor wind velocity (vw) and the angular momentum distribution in the shell of matter settling onto NS. We estimate the birthrate of SyXB as $\\sim 4.1\\times 10^{-5}$ yr$^{-1}$ to $ \\sim 6.6\\times 10^{-6}$ yr$^{-1}$ and their number in the Galaxy as $\\sim$(100 -- 1000). Assumed stellar wind velocity from cool giants is the input parameter that influences the model SyXBs population most. Among known SyXBs or candidate systems, 4U 1954+31 and IGR J16358-4724 in which NS have very long spin periods may host quasi-spherically accreting NSs. GX 1+4 has a peculiar long-term spin behavi...

  11. Optical Properties of Eu3+ Doped Lead Borate Tellurite and Zinc Borate Tellurite Glasses

    Science.gov (United States)

    Shigihalli, N. B.; Rajaramakrishna, R.; Anavekar, R. V.

    2011-07-01

    This paper describes the synthesis and optical absorption studies of the glass system 20PbO-20TeO2-(60-x)B2O3-x Eu2O3 (x = 0,1 mol %) and 20ZnO-20TeO2-(60-x)B2O3-xEu2O3 (x = 0,1 mol %). These glass systems have been successfully prepared by the melt quenching technique. The X-ray diffractograms show broad peaks indicating glasses are amorphous. DSC thermograms show glass transition temperatures around 655K for PbO content and around 675 K for ZnO content glass samples. In the UV-Visible spectra, several absorption lines are observed. The absorption peaks are around 362, 375, 393 and 464 nm for both Eu3+ doped PbO and ZnO content glass systems. These correspond to transitions from ground state of 7F0 to the excited state of 5D4, 5G4, 5L6 and 5D2 respectively for both Eu3+ doped PbO and ZnO content glass systems. These glasses are expected to give interesting applications in the area of optical devices.

  12. Modeling of plasma distortions by laser-induced ablation spectroscopy (LIAS) and implications for the interpretation of LIAS measurements

    Science.gov (United States)

    Tokar, M. Z.; Gierse, N.; Philipps, V.; Samm, U.

    2015-09-01

    For the interpretation of the line radiation observed from laser induced ablation spectroscopy (LIAS) such parameters as the density and temperature of electrons within very compact clouds of atoms and singly charged ions of ablated material have to be known. Compared to the local plasma conditions prior to the laser pulse, these can be strongly changed during LIAS since new electrons are generated by the ionisation of particles ejected from the irradiated target. Because of their transience and spatial inhomogeneity it is technically difficult to measure disturbances induced in the plasma by LIAS. To overcome this uncertainty a numerical model has been elaborated, providing a self-consistent description for the spreading of ablated particles and accompanying modifications in the plasma. The results of calculations for LIAS performed on carbon-containing targets in Ohmic and additionally heated discharges in the tokamak TEXTOR are presented. Due to the increase in the electron density the ‘ionisation per photon’ ratio, S/XB factor, is significantly enhanced compared to unperturbed plasma conditions. The impact of the amount of material ablated and of the plasma conditions before LIAS on the level of the S/XB-enhancement is investigated.

  13. Spectroscopy of mesonic molecules with heavy-light flavour mesons

    CERN Document Server

    Rathaud, D P

    2016-01-01

    In this work, we have calculated the mass spectra and decay properties of dimesonic (meson-antimeson) bound state in the variational scheme. The intermesonic interaction considered as the Hellmann potential and One Pion Exchange potential. The mass spectra of the $D\\bar{D^{*}}$, $D\\bar{D_{s}^{*}}$, $D_{s}\\bar{D^{*}}$, $D_{s}\\bar{D_{s}^{*}}$, $D^{*}\\bar{D^{*}}$, $D_{s}^{*}\\bar{D_{s}^{*}}$, $D\\bar{B^{*}}$, $D\\bar{B_{s}^{*}}$, $D_{s}\\bar{B^{*}}$, $D_{s}\\bar{B_{s}^{*}}$, $B^{*}\\bar{D}$,$B^{*}\\bar{D_{s}}$, $B\\bar{B^{*}}$, $B_{s}\\bar{B^{*}}$, $B_{c}\\bar{B^{*}}$, $B^{*}\\bar{B^{*}}$, $B^{*}\\bar{B_{s}^{*}}$, $B_{s}^{*}\\bar{B_{s}^{*}}$ etc.. are calculated. The states X(3872), $X_{2c}(4013)$ ,$Z_{b}(10610)/X_{b}$ and $Z_{b}(10650)/X_{b2}$ are compared with $D\\bar{D^{*}}$, $D^{*}\\bar{D^{*}}$, $B\\bar{B^{*}}$ and $B^{*}\\bar{B^{*}}$ dimesonic bound states. To probe the molecular structure of the compared states, we have calculated the decay properties sensitive to their long and short distance structure of hadorinc molecul...

  14. Spin-phonon coupling in epitaxial S r0.6B a0.4Mn O3 thin films

    Science.gov (United States)

    Goian, V.; Langenberg, E.; Marcano, N.; Bovtun, V.; Maurel, L.; Kempa, M.; Prokscha, T.; Kroupa, J.; Algarabel, P. A.; Pardo, J. A.; Kamba, S.

    2017-02-01

    Spin-phonon coupling is investigated in epitaxially strained S r1 -xB axMn O3 thin films with perovskite structure by means of microwave (MW) and infrared (IR) spectroscopy. In this work we focus on the S r0.6B a0.4Mn O3 composition grown on (LaAlO3) 0.3(Sr2AlTaO6 ) 0.7 substrate. The MW complex electromagnetic response shows a decrease in the real part and a clear anomaly in the imaginary part around 150 K. Moreover, it coincides with a 17 % hardening of the lowest-frequency polar phonon seen in IR reflectance spectra. In order to further elucidate this phenomenon, low-energy muon-spin spectroscopy was carried out, signaling the emergence of antiferromagnetic order with Néel temperature (TN) around 150 K. Thus, our results confirm that epitaxial S r0.6B a0.4Mn O3 thin films display strong spin-phonon coupling below TN, which may stimulate further research on tuning the magnetoelectric coupling by controlling the epitaxial strain and chemical pressure in the S r1 -xB axMn O3 system.

  15. Genetic diversity in population of largemouth bronze gudgeon (Coreius guichenoti Sauvage et Dabry) from Yangtze River determined by microsatellite DNA analysis.

    Science.gov (United States)

    Zhang, Futie; Tan, Deqing

    2010-01-01

    Largemouth bronze gudgeon (Coreius guichenoti Sauvage et Dabry 1874), one of the endemic fish species in the upper reaches of the Yangtze River in China, is a benthic and potamodromous fish that is typically found in rivers with torrential flow. Three dams in the Yangtze River, Ertan Dam, Three Gorges Dam and Gezhouba Dam, may have had vital impacts on the habitat and spawning behaviors of largemouth bronze gudgeon, and could ultimately threaten the survival of this fish. We studied the population genetic diversity of C. guichenoti samples collected at seven sites (JH, GLP, BX, HJ, MD, SDP and XB) within the Yangtze River and one of its tributaries, the Yalong River. Genetic diversity patterns were determined by analyzing genetic data from 11 polymorphic microsatellite loci. A high genetic diversity among these largemouth bronze gudgeon populations was indicated by the number of microsatellite alleles (A) and the expected heterozygosity (HE). No significant population variation occurred among GLP, BX, HJ and MD populations, but dramatic population differentiation was observed among JH and XB, two dam-blocked populations, versus other populations. Tests for bottlenecks did not indicate recent dramatic population declines and concurrent losses of genetic diversity in any largemouth bronze gudgeon populations. To the contrary, we found that dams accelerated the population differentiation of this fish.

  16. Is the decrease of the total electron energy density a covalence indicator in hydrogen and halogen bonds?

    Science.gov (United States)

    Angelina, Emilio L; Duarte, Darío J R; Peruchena, Nélida M

    2013-05-01

    In this work, halogen bonding (XB) and hydrogen bonding (HB) complexes were studied with the aim of analyzing the variation of the total electronic energy density H(r b ) with the interaction strengthening. The calculations were performed at the MP2/6-311++G(2d,2p) level of approximation. To explain the nature of such interactions, the atoms in molecules theory (AIM) in conjunction with reduced variational space self-consistent field (RVS) energy decomposition analysis were carried out. Based on the local virial theorem, an equation to decompose the total electronic energy density H(r b ) in two energy densities, (-G(r b )) and 1/4∇(2)ρ(r b ), was derived. These energy densities were linked with the RVS interaction energy components. Through the connection between both decomposition schemes, it was possible to conclude that the decrease in H(r b ) with the interaction strengthening observed in the HB as well as the XB complexes, is mainly due to the increase in the attractive electrostatic part of the interaction energy and in lesser extent to the increase in its covalent character, as is commonly considered.

  17. Inhibition of PAI-1 release from human endothelial cells by Angelica keiskei Koidzumi (Ashitaba chalcones is structure-dependent

    Directory of Open Access Journals (Sweden)

    Naoki Ohkura

    2015-12-01

    Full Text Available Angelica keiskei Koidzumi (Ashitaba is a traditional herbal medicine and it is also regarded in Japan as a health food that might have antithrombotic properties. Ashitaba exudate suppresses lipopolysaccharide (LPS-induced plasma plasminogen activator inhibitor 1 (PAI-1, a risk factor for thrombotic diseases in mice. Xanthoangelol (XA and 4-hydroxyderricin (4-HD comprise > 95% of total chalcones from Ashitaba exudates that also contain trace amounts of other chalcone subtypes. The present study aimed to determine the effects of Ashitaba chalcones including xanthoangelols B (XB, D (XD, E (XE, F (XF and XA as well as 4-HD on PAI-1 levels in the medium of stimulated human EA.hy926 endothelial cells. Xanthoangelol (10 and #61549;M inhibited PAI-1 production at a rate of 77.1%, whereas the inhibition rates of XB, XD, XE and 4-HD were not significant. Xanthoangelol F was highly cytotoxic and thus its ability to inhibit PAI-1 production could not be evaluated. The side hydrocarbon chain of XA played an important role in the excretion of inhibitory activity. Small modifications of the hydrocarbon chain or small functional groups on the A ring measurably influenced the inhibitory activity of xanthoangelols. These findings warrant future research towards an understanding of the mechanism of antithrombotic action of Ashitaba as herbal medicine or antithrombotic health food. [J Intercult Ethnopharmacol 2015; 4(4.000: 355-357

  18. QCD analysis of light charged Higgs production through polarized top quark decay in two various frames

    CERN Document Server

    Nejad, S Mohammad Moosavi

    2016-01-01

    Light and heavy charged Higgs bosons are predicted by many models with an extended Higgs sector such as the two-Higgs-doublet model (2HDM). Searches for the charged Higgs bosons have been done by the ATLAS and the CMS experiments at the Large Hadron Collider (LHC) in proton-proton collision. However, a definitive search is a program that still has to be carried out so this belongs to the LHC experiments. The experimental observation of charged Higgs bosons would indicate physics beyond the Standard Model. In the present work we study the ${\\cal O}(\\alpha_s)$ correction to the energy spectrum of the inclusive bottom-flavored mesons $(X_b)$ in polarized top quark decays into a light charged Higgs boson ($m_{H^+}X_b$ in the 2HDM, $t(\\uparrow)\\to H^+b\\to H^+X_b+Jet$. This spin-dependent energy distribution is studied in two different helicity coordinate systems. This study could be considered as a new channel to search for the charged Higgs bosons at the LHC...

  19. Dosimetric comparison between VMAT with different dose calculation algorithms and protons for soft-tissue sarcoma radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fogliata, Antonella [Oncology Inst. of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland)], e-mail: Antonella.Fogliata-Cozzi@eoc.ch; Scorsetti, Marta; Navarria, Piera [IRCCS Instituto Clinico Humanitas, Radiation Oncology, Rozzano, Milan (Italy)] [and others

    2013-04-15

    Background: To appraise the potential of volumetric modulated arc therapy (VMAT, RapidArc) and proton beams to simultaneously achieve target coverage and enhanced sparing of bone tissue in the treatment of soft-tissue sarcoma with adequate target coverage. Material and methods: Ten patients presenting with soft-tissue sarcoma of the leg were collected for the study. Dose was prescribed to 66.5 Gy in 25 fractions to the planning target volume (PTV) while significant maximum dose to the bone was constrained to 50 Gy. Plans were optimised according to the RapidArc technique with 6 MV photon beams or for intensity modulated protons. RapidArc photon plans were computed with: 1) AAA; 2) Acuros XB as dose to medium; and 3) Acuros XB as dose to water. Results: All plans acceptably met the criteria of target coverage (V{sub 95%} >90-95%) and bone sparing (D{sub 1cm}{sup 3} <50 Gy). Significantly higher PTV dose homogeneity was found for proton plans. Near-to-maximum dose to bone was similar for RapidArc and protons, while volume receiving medium/low dose levels was minimised with protons. Similar results were obtained for the remaining normal tissue. Dose distributions calculated with the dose to water option resulted 5% higher than corresponding ones computed as dose to medium. Conclusion: High plan quality was demonstrated for both VMAT and proton techniques when applied to soft-tissue sarcoma.

  20. The $t$-dependence of the pure DVCS cross section at COMPASS arXiv

    CERN Document Server

    Joerg, P.

    The key reactions to study the Generalised Parton Distributions are Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP). At COMPASS, these processes are investigated using a high intensity muon beam with a momentum of 160\\,GeV/c and a 2.5\\,m-long liquid hydrogen target. In order to optimize the selection of exclusive reactions at these energies, the target is surrounded by a new barrel-shaped time-of-flight system to detect the recoiling particles. COMPASS-II covers the up to now unexplored $x_{B}$ domain ranging from 0.01 to 0.15. From the sum of cross sections measured with positive and negative beam polarities, the pure DVCS cross-section and its $t$-dependence have been extracted resulting in a first model-independent determination of the transverse size of the partonic distribution of the nucleon $\\sqrt{}= (0.578 \\ \\pm \\ 0.042\\ _{- \\ 0.018}^{+ \\ 0.006})\\,\\textsf{fm} $ at a mean $x_{B}$ value of 0.056.

  1. Deep exclusive $\\pi^+$ electroproduction off the proton at CLAS

    CERN Document Server

    Park, K; Guidal, M; Laget, J M; Adhikari, K P; Aghasyan, M; Amaryan, M J; Anghinolfi, M; Avakian, H; Baghdasaryan, H; Ball, J; Baltzell, N A; Battaglieri, M; Bedlinsky, I; Bennett, R P; Biselli, A S; Bookwalter, C; Boiarinov, S; Briscoe, W J; Brooks, W K; Burkert, V B; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Contalbrigo, M; D'Angelo, A; Daniel, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Dodge, G E; Doughty, D; Dupre, R; Egiyan, H; Alaoui, A El; Fassi, L El; Eugenio, P; Fedotov, G; Fegan, S; Fleming, J A; Forest, T A; Gar{\\c}con, M; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Gohn, W; Golovatch, E; Graham, L; Griffioen, K A; Guegan, B; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Heddle, D; Hicks, K; Ho, D; Holtrop, M; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Jenkins, D; Jo, H S; Keller, D; Khandaker, M; Khetarpal, P; Kim, A; Kim, W; Klein, F J; Koirala, S; Kubarovsky, A; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Livingston, K; Lu, H Y; MacGregor, I J D; Mao, Y; Markov, N; Martinez, D; Mayer, M; McKinnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moutarde, H; Munevar, E; Camacho, C Munoz; Nadel-Turonski, P; Nepali, C S; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L L; Paremuzyan, R; Park, S; Pasyuk, E; Pereira, S Anefalos; Phelps, E; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Puckett, A J R; Raue, B A; Ricco, G; Rimal, D; Ripani, M; Rosner, G; Rossi, P; Sabatie, F; Saini, M S; Salgado, C; Schott, D; Schumacher, R A; Seder, E; Seraydaryan, H; Sharabian, Y G; Smith, E S; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S S; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tang, W; Taylor, C E; Tian, Ye; Tkachenko, S; Trivedi, A; Ungaro, M; Vernarsky, B; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zachariou, N; Zhang, J; Zhao, Z W; Zonta, I

    2012-01-01

    The exclusive electroproduction of $\\pi^+$ above the resonance region was studied using the $\\rm{CEBAF}$ Large Acceptance Spectrometer ($\\rm{CLAS}$) at Jefferson Laboratory by scattering a 6-GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of $\\rm{CLAS}$, together with the high luminosity, allowed us to measure the cross section for the $\\gamma^* p \\to n \\pi^+$ process in 140 ($Q^2$, $x_B$, $t$) bins: $0.16<x_B<0.58$, 1.6 GeV$^2<$$Q^2$$<4.5$ GeV$^2$ and 0.1 GeV$^2<$$-t$$<5.3$ GeV$^2$. For most bins, the statistical accuracy is on the order of a few percent. Differential cross sections are compared to two theoretical models, based either on hadronic (Regge phenomenology) or on partonic (handbag diagram) degrees of freedom. Both can describe the gross features of the data reasonably well, but differ strongly in their ingredients. If the handbag approach can be validated in this kinematical region, our data contain the interesting potential to experim...

  2. Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses.

    Directory of Open Access Journals (Sweden)

    Benjamin Schwessinger

    2015-03-01

    Full Text Available Plant plasma membrane localized pattern recognition receptors (PRRs detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24, two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components.

  3. Search for baryon and lepton number violation in heavy baryon decays and the background studies for exotic searches

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00392425

    The thesis describes searches for baryon and lepton number violation in $X_{b} \\rightarrow K^{-} \\mu^{+} (X_{b} = \\Lambda^0_{b}, \\Xi_{b}^{0})$ decays. The study is performed in the \\mbox{LHC\\textit{b}} experiment using data sample corresponding to an integrated luminosity of $3.0 fb^{-1}$ of proton-proton collisions at the centre-of-mass energy of $7$TeV $8$TeV, collected in 2011 (2012), respectively. No statistically significant signal of the decays in question has been found. As a result, the upper limits have been set: $\\cal B ( \\Lambda^0_{b} \\rightarrow K^{-} \\mu^{+} ) < 3.6 \\times 10^{-9}$ and $\\cal B (\\Xi_{b}^{0} \\rightarrow K^{-} \\mu^{+} ) < 1.8 \\times 10^{-8}$ at the $95\\%$ confidence level. The second part of the thesis presents the background studies for exotic searches. The measurement of $\\sigma(b\\overline b)$ and $\\sigma(c\\overline c)$ production cross-sections with $b- (c-)$ hadron inclusive final states has been performed with data collected by the \\mbox{LHC\\textit{b}} experiment in 20...

  4. HPLC Determination of Geniposide in Yuye Qinghuo Capsule%HPLC法测定玉叶清火胶囊中栀子苷的含量

    Institute of Scientific and Technical Information of China (English)

    高扬; 孙家艳; 蒋小文

    2012-01-01

    目的 建立高效液相色谱法测定玉叶清火胶囊中栀子苷的含量.方法 采用Welch Materials XB-C18柱(4.6 mm×150mm,5 μm),流动相为甲醇-水(30∶70),检测波长为238 nm.结果 此方法线性关系良好,平均加样回收率为99.0%.结论此方法简便、快捷、准确,可用于测定玉叶清火胶囊中栀子苷的含量.%OBJECTIVE To establish a HPLC method for the determination of geniposide in Yuye Qinghuo Capsule. METHODS The HPLC method was used at Welch Materials XB-C18 column(4.6 mm× 150 mm,5 μm). The mobile phase was of methanol-water(30:70). The detective wavelength was 238 nm. RESULTS The linearity of this method was good with the average recovery of 99. 0% . CONCLUSION The method is simple,quick and accurate. It can be used for the determination of the content of geniposide in Yuye Qinghuo Capsule.

  5. B_c^+- decays into tetraquarks

    CERN Document Server

    Ali, A.; Polosa, A.D.; Riquer, V.

    2016-01-01

    The recent observation by the D0 collaboration of a narrow structure X(5568) consisting of four different quark flavors bdus, has not been confirmed by LHCb. More data and dedicated analyses are needed to cover a larger mass range. In the tightly bound diquark model, we estimate the lightest bdus, 0^+ tetraquark at a mass of about 5770 MeV, approximately 200 MeV above the reported X(5568), and just 7 MeV below the B Kbar threshold. The charged tetraquark is accompanied by I=1 and I=0 neutral partners almost degenerate in mass. A bdus, S-wave, 1^+ quartet at 5820 MeV is implied as well. In the charm sector, cdus, 0^+ and 1^+ tetraquarks are predicted at 2365 MeV and 2501 MeV, about 40-50 MeV heavier than D_{s0}(2317) and D_{s1}(2460). bdus tetraquarks can be searched in the hadronic debris of a jet initiated by a b. However, some of them may also be produced in B_c decays. The proposed discovery modes of S-wave tetraquarks are B_c --> X_{b0} + pi with the subsequent decays X_{b0} --> B_s + pi, giving rise to f...

  6. Magnetic octupole order in Ce0.7La0.3B6: A polarized neutron diffraction study

    Science.gov (United States)

    Kuwahara, K.; Iwasa, K.; Kohgi, M.; Aso, N.; Sera, M.; Iga, F.; Matsuura, M.; Hirota, K.

    2009-09-01

    Recently, in phase IV of CexLa1-xB6, weak but distinct superlattice reflections from the order parameter of phase IV have been detected by our unpolarized neutron scattering experiment [K. Kuwahara, K. Iwasa, M. Kohgi, N. Aso, M. Sera, F. Iga, J. Phys. Soc. Japan 76 (2007) 093702]. The scattering vector dependence of the intensity of superlattice reflections is quite unusual; the intensity is stronger for high scattering vectors. This result strongly indicates that the order parameter of phase IV is the magnetic octupole. However, the possibility that the observed superlattice reflections are due to lattice distortions could not be completely ruled out only on the basis of the unpolarized neutron scattering experiment. To confirm that the superlattice reflections are magnetic, therefore, we have performed a single crystal polarized neutron diffraction experiment on Ce0.7La0.3B6. The obtained result has clearly shown that the time reversal symmetry is broken by the order parameter of phase IV. This is further evidence for the magnetic octupole order in CexLa1-xB6.

  7. Marginally Stable Nuclear Burning

    Science.gov (United States)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high-inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi-periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  8. X-ray Follow-ups of XSS J12270-4859: A Low-mass X-ray Binary with Gamma-ray Fermi-LAT Association

    Science.gov (United States)

    deMartino, D.; Belloni, T.; Falanga, M.; Papitto, A.; Motta, S.; Pellizzoni, A.; Evangelista, Y.; Piano, G.; Masetti, N.; Mouchet, M.; Mukai, K.; Possenti, A.

    2013-01-01

    Context. XSS J1227.0-4859 is a peculiar, hard X-ray source recently positionally associated to the Fermi-LAT source 1FGL J1227.9- 4852/2FGL J1227.7-4853. Multi-wavelength observations have added information on this source, indicating a low-luminosity lowmass X-ray binary (LMXB), but its nature is still unclear. Aims. To progress in our understanding, we present new X-ray data from a monitoring campaign performed in 2011 with the XMM-Newton, RXTE, and Swift satellites and combine them with new gamma-ray data from the Fermi and AGILE satellites. We complement the study with simultaneous near-UV photometry from XMM-Newton and with previous UV/optical and near-IR data. Methods. We analysed the temporal characteristics in the X-rays, near-UV, and gamma rays and studied the broad-band spectral energy distribution from radio to gamma rays. Results. The X-ray history of XSS J1227 over 7 yr shows a persistent and rather stable low-luminosity (6 × 1033 d2 1 kpcerg s-1) source, with flares and dips being peculiar and permanent characteristics. The associated Fermi-LAT source 2FGL J1227.7-4853 is also stable over an overlapping period of 4.7 yr. Searches for X-ray fast pulsations down to msec give upper limits to pulse fractional amplitudes of 15-25% that do not rule out a fast spinning pulsar. The combined UV/optical/near-IR spectrum reveals a hot component at approximately 13 kK and a cool one at approximately 4.6 kK. The latter would suggest a late-type K2-K5 companion star, a distance range of 1.4-3.6 kpc, and an orbital period of 7-9 h. A near-UV variability (6 h) also suggests a longer orbital period than previously estimated. Conclusions. The analysis shows that the X-ray and UV/optical/near-IR emissions are more compatible with an accretion-powered compact object than with a rotational powered pulsar. The X-ray to UV bolometric luminosity ratio could be consistent with a binary hosting a neutron star, but the uncertainties in the radio data may also allow an LMXB

  9. Evolution of surfaces properties for 100Cr6 steel by implantation and ionic mixing; Evolution des proprietes de surface de l`acier 100Cr6 par implantation et melange ioniques

    Energy Technology Data Exchange (ETDEWEB)

    Faussemagne, A.

    1996-07-09

    Physico-chemical characterizations performed on samples of 100Cr6 steel implanted both with boron and nitrogen revealed the formation of boron nitride along with the following new phases: Fe{sub 1-x}(B, N), Fe{sub 2-x}(B, N) and Fe{sub 3-x}(B, N). A thorough analysis of boron NITRIDE (5BN) indicates that a low ion current density (3 {mu}A.cm{sup -2}) in the case of the boron plus nitrogen sequence favours the formation of sp{sup 2} bonds (hexagonal-BN) while a higher ion current density (6{mu}A.cm{sup -2}) promotes sp{sup 3} bonds (cubic-BN) in the opposite sequence. Tribological tests carried out on these samples revealed that nitrogen and boron implantations do not lead to any significant improvement of friction and wear at variance with the results obtained by others authors. However, on a set samples accidentally contaminated with carbon during implantation, we noticed a considerable improvement of these tribological parameters. As this pollution is commonly encountered in surface treatment by ion beams, one can invoke this phenomenon to explain the origin of the discrepancy reported by the literature. Extensive investigations allowed us to conclude that surface carbon, whatever its origin (contamination, ion implantation or ion beam mixed coating), provided that its amount is sufficiently high ({>=}2 x 10{sup 16} C.cm{sup -2}), decreases the coefficient of friction by a factor 5 and reduces drastically ({approx} 100) the wear. A careful examination of the whole results led us to propose a theoretical model, based on the role of the asperities of the two bodies in contact, to explain the evolution of the coefficient of friction and wear with the amount of surface carbon. This analysis revealed that in order to improve friction and wear of 100Cr6 steel, one needs to coat this material with a well adherent carbon layer having a thickness higher than the asperity heights of the two bodies in contact. Finally, this study allowed us to develop a simple lower

  10. A model-based 3D patient-specific pre-treatment QA method for VMAT using the EPID

    Science.gov (United States)

    McCowan, P. M.; Asuni, G.; van Beek, T.; van Uytven, E.; Kujanpaa, K.; McCurdy, B. M. C.

    2017-02-01

    This study reports the development and validation of a model-based, 3D patient dose reconstruction method for pre-treatment quality assurance using EPID images. The method is also investigated for sensitivity to potential MLC delivery errors. Each cine-mode EPID image acquired during plan delivery was processed using a previously developed back-projection dose reconstruction model providing a 3D dose estimate on the CT simulation data. Validation was carried out using 24 SBRT-VMAT patient plans by comparing: (1) ion chamber point dose measurements in a solid water phantom, (2) the treatment planning system (TPS) predicted 3D dose to the EPID reconstructed 3D dose in a solid water phantom, and (3) the TPS predicted 3D dose to the EPID and our forward predicted reconstructed 3D dose in the patient (CT data). AAA and AcurosXB were used for TPS predictions. Dose distributions were compared using 3%/3 mm (95% tolerance) and 2%/2 mm (90% tolerance) γ-tests in the planning target volume (PTV) and 20% dose volumes. The average percentage point dose differences between the ion chamber and the EPID, AcurosXB, and AAA were 0.73  ±  1.25%, 0.38  ±  0.96% and 1.06  ±  1.34% respectively. For the patient (CT) dose comparisons, seven (3%/3 mm) and nine (2%/2 mm) plans failed the EPID versus AAA. All plans passed the EPID versus Acuros XB and the EPID versus forward model γ-comparisons. Four types of MLC sensitive errors (opening, shifting, stuck, and retracting), of varying magnitude (0.2, 0.5, 1.0, 2.0 mm), were introduced into six different SBRT-VMAT plans. γ-comparisons of the erroneous EPID dose and original predicted dose were carried out using the same criteria as above. For all plans, the sensitivity testing using a 3%/3 mm γ-test in the PTV successfully determined MLC errors on the order of 1.0 mm, except for the single leaf retraction-type error. A 2%/2 mm criteria produced similar results with two more additional detected

  11. Hard-tail emission in the soft state of low-mass X-ray binaries and their relation to the neutron star magnetic field

    CERN Document Server

    Asai, Kazumi; Mastuoka, Masaru; Sugizaki, Mutsumi

    2016-01-01

    Average hard-tail X-ray emission in the soft state of nine bright Atoll low-mass X-ray binaries containing a neutron star (NS-LMXBs) are investigated by using the light curves of MAXI/GSC and Swift/BAT. Two sources (4U 1820$-$30 and 4U 1735$-$44) exhibit large hardness ratio (15--50 keV$/$2--10 keV: {\\it HR} $>$ 0.1), while the other sources distribute at {\\it HR} $\\ltsim$ 0.1. In either case, {\\it HR} does not depend on the 2--10 keV luminosity. Therefore the difference of {\\it HR} is due to the 15--50 keV luminosity, which is Comptonized emission. The Compton cloud is assumed to be around the neutron star. The size of the Compton cloud would affect the value of {\\it HR}. Although the magnetic field of NS-LMXB is weak, we could expect a larger Alfv\\'{e}n radius than the innermost stable circular orbit or the neutron star radius in some sources. In such cases, the accretion inflow is stopped at the Alfv\\'{e}n radius and would create relatively large Compton cloud. It would result in the observed larger Compto...

  12. Evolution towards and beyond accretion-induced collapse of massive white dwarfs and formation of millisecond pulsars

    CERN Document Server

    Tauris, Thomas M; Yoon, Sung-Chul; Langer, Norbert

    2013-01-01

    Millisecond pulsars (MSPs) are generally believed to be old neutron stars (NSs), formed via type Ib/c core-collapse supernovae (SNe), which have been spun up to high rotation rates via accretion from a companion star in a low-mass X-ray binary (LMXB). In an alternative formation channel, NSs are produced via the accretion-induced collapse (AIC) of a massive white dwarf (WD) in a close binary. Here we investigate binary evolution leading to AIC and examine if NSs formed in this way can subsequently be recycled to form MSPs and, if so, how they can observationally be distinguished from pulsars formed via the standard core-collapse SN channel in terms of their masses, spins, orbital periods and space velocities. Numerical calculations with a detailed stellar evolution code were used for the first time to study the combined pre- and post-AIC evolution of close binaries. We investigated the mass transfer onto a massive WD in 240 systems with three different types of non-degenerate donor stars: main-sequence stars,...

  13. Effects of variability of X-ray binaries on the X-ray luminosity functions of Milky Way

    Science.gov (United States)

    Islam, Nazma; Paul, Biswajit

    2016-08-01

    The X-ray luminosity functions of galaxies have become a useful tool for population studies of X-ray binaries in them. The availability of long term light-curves of X-ray binaries with the All Sky X-ray Monitors opens up the possibility of constructing X-ray luminosity functions, by also including the intensity variation effects of the galactic X-ray binaries. We have constructed multiple realizations of the X-ray luminosity functions (XLFs) of Milky Way, using the long term light-curves of sources obtained in the 2-10 keV energy band with the RXTE-ASM. The observed spread seen in the value of slope of both HMXB and LMXB XLFs are due to inclusion of variable luminosities of X-ray binaries in construction of these XLFs as well as finite sample effects. XLFs constructed for galactic HMXBs in the luminosity range 1036-1039 erg/sec is described by a power-law model with a mean power-law index of -0.48 and a spread due to variability of HMXBs as 0.19. XLFs constructed for galactic LMXBs in the luminosity range 1036-1039 erg/sec has a shape of cut-off power-law with mean power-law index of -0.31 and a spread due to variability of LMXBs as 0.07.

  14. Swift J1357.2-0933: the faintest black hole?

    CERN Document Server

    Padilla, M Armas; Degenaar, N; Muñoz-Darias, T; Casares, J; Fender, R P

    2014-01-01

    Swift J1357.2-0933 is the first confirmed very faint black hole X-ray transient and has a short orbital period of 2.8 hr. We observed Swift J1357.2-0933 for ~50 ks with XMM-Newton in 2013 July during its quiescent state. The source is clearly detected at a 0.5-10 keV flux of ~3x10^-15 erg cm-2 s-1. If the source is located at a distance of 1.5 kpc (as suggested in the literature), this would imply a luminosity of ~8x10^29 erg s-1, making it the faintest detected quiescent black hole LMXB. This would also imply that there is no indication of a reversal in the quiescence X-ray luminosity versus orbital period diagram down to 2.8 hr, as has been predicted theoretically and recently supported by the detection of the 2.4 hr orbital period black hole MAXI J1659-152 at a 0.5-10 keV X-ray luminosity of ~ 1.2 x 10^31 erg s-1. However, there is considerable uncertainty in the distance of Swift J1357.2-0933 and it may be as distant as 6 kpc. In this case, its quiescent luminosity would be Lx ~ 1.3 x 10^31 erg s-1, i.e.,...

  15. The outburst of the X-ray nova GRS 1739-278 in September, 2016

    CERN Document Server

    Mereminskiy, I A; Krivonos, R A; Grebenev, S A; Burenin, R A; Sunyaev, R A

    2016-01-01

    During the scanning observations of the Galactic Center region in August - September 2016 we detected the new outburst of the historical X-ray nova GRS 1739-278, the black hole candidate LMXB system. In this letter we present results of INTEGRAL and Swift-XRT observations taken during the outburst. In hard X-ray band (20-60 keV) the flux from the source raised from $\\sim$11 to $\\sim$30 mCrab between 3 and 14 of September. For nearly 8 days the source has been observed at this flux level and then faded to $\\sim$15 mCrab. The broadband quasi-simultaneous spectrum obtained during the outburst is well described by the absorbed powerlaw with the photon index $\\Gamma=1.86\\pm0.07$ in broad energy range 0.5-150 keV, with absorption corresponding to ${N_{H}}=2.3\\times10^{22}$ cm$^{-2}$ assuming solar abundance. Based on this we can conclude that the source was in the low/hard state. From the lightcurve and spectra we propose that this outburst was `failed', i.e. amount of accreted matter was not sufficient to achieve ...

  16. On the possibility of a helium white dwarf donor in the presumed ultracompact binary 2S 0918-549

    CERN Document Server

    in 't Zand, J J M; Van der Sluys, M V; Verbunt, F; Pols, O R

    2005-01-01

    2S 0918-549 is a low-mass X-ray binary (LMXB) with a low optical to X-ray flux ratio. Probably it is an ultracompact binary with an orbital period shorter than 60 min. Such binaries cannot harbor hydrogen rich donor stars. As with other (sometimes confirmed) ultracompact LMXBs, 2S 0918-549 is observed to have a high neon-to-oxygen abundance ratio (Juett et al. 2001) which has been used to argue that the companion star is a CO or ONe white dwarf. However, type-I X-ray bursts have been observed from several of these systems implying the presence of hydrogen or helium on the neutron star surface. In this paper, we argue that the companion star in 2S 0918-549 is a helium white dwarf We first present a Type I X-ray burst from 2S 0918-549 with a long duration of 40 minutes. We show that this burst is naturally explained by accretion of pure helium at the inferred accretion rate of ~0.01 times the Eddington accretion rate. At higher accretion rates of ~0.1 Eddington, hydrogen is required to explain long duration bur...

  17. Dense, Parsec-Scale Clumps near the Great Annihilator

    CERN Document Server

    Hodges-Kluck, E J; Harris, A I; Lamb, J W; Hodges, M W

    2009-01-01

    We report on Combined Array for Research in Millimeter-Wave Astronomy (CARMA) and James Clerk Maxwell Telescope (JCMT) observations toward the Einstein source 1E 1740.7-2942, a LMXB commonly known as the "Great Annihilator." The Great Annihilator is known to be near a small, bright molecular cloud on the sky in a region largely devoid of emission in 12-CO surveys of the Galactic Center. The region is of interest because it is interior to the dust lanes which may be the shock zones where atomic gas from HI nuclear disk is converted into molecular gas. We find that the region is populated with a number of dense (n ~ 10^5 cm^-3) regions of excited gas with small filling factors, and estimate that up to 1-3 x 10^5 solar masses of gas can be seen in our maps. The detection suggests that a significant amount of mass is transported from the shock zones to the GC star-forming regions in the form of small, dense bundles.

  18. The First X-ray Measurement Of SAX J1750.8-2900 In Quiescence

    Science.gov (United States)

    Lowell, Alexander W.; Tomsick, J.; Bodaghee, A.; Boggs, S.; Heinke, C.; Kaaret, P.; Chaty, S.; Rodriguez, J.; Walter, R.

    2011-09-01

    We have performed the first sensitive X-ray observation of the low-mass X-ray binary (LMXB) SAX J1750.8-2900 in quiescence with XMM-Newton. Both a classical black body model and a non-magnetized, pure hydrogen neutron star (NS) atmosphere model were fit to the 0.3-12.0 keV spectrum. In addition, a power law component was added to the model in order to search for evidence of harder emission not accounted for by the thermal component. Assuming a previously measured upper limit on the distance to SAX J1750.8-2900 of 6.3 +/- 0.7 kpc, we find that the upper limit for the luminosity of this source is 8.1 (+1.9) (-1.8) E33 erg/s for the NS atmosphere model, and 2.3 (+0.9) (-0.5) E33 erg/s for the black body model. We conclude that the power law contribution to the total luminosity is low, and we discuss implications for the origin of the power-law that is present in some systems. Although many quiescent NS transients show evidence for enhanced cooling, the quiescent luminosity for SAX J1750.8-2900 may be high enough that the standard cooling scenario may be sufficient.

  19. On the Origin of Broad Iron Lines in Neutron Star Low-mass X-ray Binaries

    CERN Document Server

    Chiang, Chia-Ying; Miller, Jon M; Barret, Didier; Fabian, Andy C; D'Ai, Antonino; Parker, Michael L; Bhattacharyya, Sudip; Burderi, Luciano; Di Salvo, Tiziana; Egron, Elise; Homan, Jeroen; Iaria, Rosario; Lin, Dacheng; Miller, M Coleman

    2015-01-01

    Broad Fe K emission lines have been widely observed in the X-ray spectra of black hole systems, and in neutron star systems as well. The intrinsically narrow Fe K fluorescent line is generally believed to be part of the reflection spectrum originating in an illuminated accretion disk, and broadened by strong relativistic effects. However, the nature of the lines in neutron star LMXBs has been under debate. We therefore obtained the longest, high-resolution X-ray spectrum of a neutron star LMXB to date with a 300 ks Chandra HETGS observation of Serpens X-1. The observation was taken under the "continuous clocking" mode and thus 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 highest spectral resolution view of the Fe K region and we find no strong evidence for add...

  20. Discovery of a candidate quiescent low-mass X-ray binary in the globular cluster NGC 6553

    CERN Document Server

    Guillot, Sebastien; Brown, Edward F; Pavlov, George G; Zavlin, Vyacheslav E

    2011-01-01

    This paper reports the search for quiescent low-mass X-ray binaries (qLMXBs) in the globular cluster (GC) NGC 6553 using an XMM-Newton observation designed specifically for that purpose. The analysis leading to the spectral identification of one candidate qLMXB in the core of the cluster, based on the consistency of the spectrum with a neutron star H-atmosphere model at the distance of NGC 6553, is described in this paper. Specifically, the best-fit radius found using the three XMM European Photon Imaging Camera (EPIC) spectra is R_NS=6.3(+2.3)(-0.8) km (for M_NS=1.4 Msun) and the best-fit temperature is kTeff=136(+21)(-34) eV. Both physical parameters are in accordance with typical values of previously identified qLMXBs in GC and in the field, i.e. R_NS~5-20 km and kTeff~50-150 eV. A power-law (PL) component with a photon index Gamma=2.1(+0.5)(-0.8) is also required for the spectral fit and contributes to ~33% of the total flux of the X-ray source. A detailed analysis supports the hypothesis that the PL comp...

  1. The cooling phase of Type-I X-ray bursts in 4U 1636-53

    CERN Document Server

    Zhang, Guobao; Altamirano, Diego

    2010-01-01

    Time-resolved spectra during the cooling phase of thermonuclear X-ray bursts in low-mass X-ray binaries (LMXBs) can be used to measure the radii and masses of neutron stars. We analyzed ~ 300 bursts of the LMXB 4U 1636-53 using data from the Rossi X-ray Timing Explorer. We divided the bursts in three groups, photospheric radius expansion (PRE), hard non-PRE and soft non-PRE bursts, based on the properties of the bursts and the state of the source at the time of the burst. For the three types of bursts, we found that the average relation between the bolometric flux and the temperature during the cooling phase of the bursts is significantly different from the canonical $F \\propto T^4$ relation that is expected if the apparent emitting area on the surface of the neutron star remains constant as the flux decreases during the decay of the bursts. We also found that a single power law cannot fit the average flux-temperature relation for any of the three types of bursts, and that the flux-temperature relation for th...

  2. Discovery of twin kHz quasi periodic oscillations in the low mass X-ray binary XTE J1701-407

    CERN Document Server

    Pawar, Devraj D; Altamirano, Diego; Linares, Manuel; Shanthi, K; Strohmayer, Tod; Bhattacharya, Dipankar; van der Klis, Michiel

    2013-01-01

    We report the discovery of kHz quasi periodic oscillations (QPOs) in three Rossi X-ray Timing Explorer observations of the low mass X-ray binary (LMXB) XTE J1701-407. In one of the observations we detect a kHz QPO with a characteristic frequency of 1153 +/- 5 Hz, while in the other two observations we detect twin QPOs at characteristic frequencies of 740 +/- 5 Hz, 1112 +/- 17 Hz and 740 +/- 11 Hz, 1098 +/- 5 Hz. All detections happen when XTE J1701-407 was in its high intensity soft state, and their single trial significance are in the 3.1-7.5 sigma range. The frequency difference in the centroid frequencies of the twin kHz QPOs (385 +/- 13 Hz) is one of the largest seen till date. The 3-30 keV fractional rms amplitude of the upper kHz QPO varies between ~18 % and ~30 %. XTE J1701-407, with a persistent luminosity close to 1 % of the Eddington limit, is among the small group of low luminosity kHz QPO sources and has the highest rms for the upper kHz QPO detected in any source. The X-ray spectral and variabili...

  3. Broad iron emission line and kilohertz quasi-periodic oscillations in the neutron star system 4U 1636-53

    CERN Document Server

    Sanna, Andrea; Altamirano, Diego; Belloni, Tomaso; Hiemstra, Beike; Linares, Manuel

    2014-01-01

    Both the broad iron (Fe) line and the frequency of the kilohertz quasi-periodic oscillations (kHz QPOs) in neutron star low-mass X-ray binaries (LMXBs) can potentially provide independent measures of the inner radius of the accretion disc. We use XMM-Newton and simultaneous Rossi X-ray Timing Explorer observations of the LMXB 4U 1636-53 to test this hypothesis. We study the properties of the Fe-K emission line as a function of the spectral state of the source and the frequency of the kHz QPOs. We find that the inner radius of the accretion disc deduced from the frequency of the upper kHz QPO varies as a function of the position of the source in the colour-colour diagram, in accordance with previous work and with the standard scenario of accretion disc geometry. On the contrary, the inner disc radius deduced from the profile of the Fe line is not correlated with the spectral state of the source. The values of the inner radius inferred from kHz QPOs and Fe lines, in four observations, do not lead to a consisten...

  4. Probing thermonuclear flame spreading on neutron stars using burst rise oscillations

    Science.gov (United States)

    Chakraborty, Manoneeta; Bhattacharyya, Sudip

    2016-07-01

    Intense X-ray bursts (type-I bursts), originated from runaway thermonuclear processes, are observed from the surfaces of many accreting neutron star Low Mass X-ray Binary (LMXB) systems and they provide an important tool to constrain the neutron star equation of state. Periodic intensity variations during these bursts, termed burst oscillations, are observed in about 10% of thermonuclear bursts. Oscillations during the rising phases of thermonuclear bursts are hypothesized to originate from an expanding hot-spot on the surface of the neutron star. We studied the evolution of oscillations during the rising phase of a large sample of thermonuclear bursts from 10 bursting neutron stars in order to probe the process of burning front propagation during an X-ray burst. Our results show observational evidences of expanding hot-spot with spin modulated flame speeds, possibly due to the effects of the Coriolis force present as a result of the high stellar spin (270-620 Hz). This implies that the flame propagation is latitude-dependent and we address the factors affecting the detection and non-detection of burst rise oscillations in the light of this Coriolis force modulated flame spreading scenario.

  5. Simultaneous X-ray/optical observations of GX 9+9 (4U 1728-16)

    CERN Document Server

    Kong, A K H; Homer, L; Kuulkers, E; O'Donoghue, D

    2006-01-01

    We report on the results of the first simultaneous X-ray (RXTE) and optical (SAAO) observations of the luminous low mass X-ray binary (LMXB) GX 9+9 in 1999 August. The high-speed optical photometry revealed an orbital period of 4.1958 hr and confirmed previous observations, but with greater precision. No X-ray modulation was found at the orbital period. On shorter timescales, a possible 1.4-hr variability was found in the optical light curves which might be related to the mHz quasi-periodic oscillations seen in other LMXBs. We do not find any significant X-ray/optical correlation in the light curves. In X-rays, the colour-colour diagram and hardness-intensity diagram indicate that the source shows characteristics of an atoll source in the upper banana state, with a correlation between intensity and spectral hardness. Time-resolved X-ray spectroscopy suggests that two-component spectral models give a reasonable fit to the X-ray emission. Such models consist of a blackbody component which can be interpreted as ...

  6. Detection of a 1258 Hz high-amplitude kilohertz quasi-periodic oscillation in the ultra-compact X-ray binary 1A 1246-588

    CERN Document Server

    Jonker, P G; Méndez, M; Van der Klis, M

    2007-01-01

    We have observed the ultra-compact low-mass X-ray binary (LMXB) 1A 1246-588 with the Rossi X-ray Timing Explorer (RXTE). In this manuscript we report the discovery of a kilohertz quasi-periodic oscillation (QPO) in 1A 1246-588. The kilohertz QPO was only detected when the source was in a soft high-flux state reminiscent of the lower banana branch in atoll sources. Only one kilohertz QPO peak is detected at a relatively high frequency of 1258+-2 Hz and at a single trial significance of more than 7 sigma. Kilohertz QPOs with a higher frequency have only been found on two occasions in 4U 0614+09. Furthermore, the frequency is higher than that found for the lower kilohertz QPO in any source, strongly suggesting that the QPO is the upper of the kilohertz QPO pair often found in LMXBs. The full-width at half maximum is 25+-4 Hz, making the coherence the highest found for an upper kilohertz QPO. From a distance estimate of ~6 kpc from a radius expansion burst we derive that 1A 1246-588 is at a persistent flux of ~0....

  7. Sco X-1 The Evolution and Nature of the Twin Compact Radio Lobes

    CERN Document Server

    Fomalont, E B; Bradshaw, C F

    2001-01-01

    The radio components associated with the LMXB Sco X-1 have been monitored with extensive VLBI imaging at 1.7 and 5.0 GHz over four years, including a 56-hour continuous VLBI observation in 1999 June. We often detected one strong and one weak compact radio component, moving in opposite directions from the radio core. We suggest that the moving components are radio lobes generated by the disruption of energy flow in a twin-beam from the binary system. The average lifetime of a lobe-pair, the space motion of the lobes and the measured energy flow in the beam are discussed in Astro-ph/0104325. The lobe has a flux density that is variable over a time-scale of one hour, a measured minimum size of 1 mas (2.8 au), and is extended perpendicular to its motion. This short electron radiative lifetime may be caused by synchrotron losses if the lobe magnetic field is 300 G, or by adiabatic expansion of the electrons as soon as they are produced at the working surface. The lobes also show periods of slow expansion and a ste...

  8. Hidden AGNs in Early-Type Galaxies

    CERN Document Server

    Paggi, A; Civano, F; Pellegrini, S; Elvis, M; Kim, D -W

    2015-01-01

    We present a stacking analysis of the complete sample of Early Type Galaxies (ETGs) in the \\textit{Chandra} COSMOS (C-COSMOS) survey, to explore the nature of the X-ray luminosityin the redshift and stellar luminosity ranges \\(0LMXB}\\gtrsim 6\\times{10}^{42}\\mbox{ er...

  9. Analytical model of strange star in low-mass X-ray binary KS 1731-260

    Science.gov (United States)

    Hossein, Sk. Monowar; Farhad, Nur; Molla, Sajahan; Kalam, Mehedi

    2016-10-01

    In this article using Mehra (Aust. Math. Soc. 6:153, 1966) metric, we propose a model for the strange star in low-mass X-ray binary (LMXB) KS 1731-260 (Özel et al., Astrophys. J. 748:5, 2012) which describes interior space-time of the star. We study the strange star's interior and exterior physical properties. We calculate central density (ρ0), surface density (ρb), central pressure (p 0), surface redshift (Z s) and probable radius of the above mentioned strange star, which is very much consistent with the reported data. The special feature of this article is that the radius of the star is 12.31 km where pressure becomes zero and mass comes out as 2.09521 M_{⊙}, whereas maximum mass comes out as 2.09996 M _{⊙} with radius 12.53 km. Therefore, our model suggests that there may be a gaseous atmosphere over a range of 0.22 km outside of the stellar structure which justify the claim of Ho and Heinke (Nature 462:71, 2009).

  10. Swift J174540.7-290015: a new accreting binary in the Galactic Center

    CERN Document Server

    Ponti, G; De Marco, B; Rea, N; Rau, A; Haberl, F; Zelati, F Coti; Bozzo, E; Ferrigno, C; Bower, G C; Demorest, P

    2016-01-01

    We report on the identification of the new Galactic Center (GC) transient Swift J174540.7-290015 as a likely low mass X-ray binary (LMXB) located at only 16 arcsec from Sgr A*. This transient was detected on 2016 February 6th during the Swift GC monitoring, and it showed long-term spectral variations compatible with a hard to soft state transition. We observed the field with XMM-Newton on February 26th for 35 ks, detecting the source in the soft state, characterised by a low level of variability and a soft X-ray thermal spectrum with a high energy tail (detected by INTEGRAL up to ~50 keV), typical of either accreting neutron stars or black holes. We observed: i) a high column density of neutral absorbing material, suggesting that Swift J174540.7-290015 is located near or beyond the GC and; ii) a sub-Solar Iron abundance, therefore we argue that Iron is depleted into dust grains. The lack of detection of FeK absorption lines, eclipses or dipping suggests that the accretion disc is observed at a low inclination...

  11. Probing the origin of Pulsar wind with a Black widow pulsar 2FGL J2339.6-0532

    Science.gov (United States)

    Yatsu, Yoichi; Shibata, Shinpei; Kawai, Nobuyuki; Kataoka, Jun; Saito, Yoshihiko

    Multi-wavelength observations of a black widow binary system 2FGL2339.6-0532 are presented. Black widow pulsars are believed to be in the intermediate stage between LMXB and isolated millisecond pulsars(MSPs). In a typical black widow system, the recycled MSP is evaporating up its companion star by the powerful pulsar wind. Fermi gamma-ray source 2FGL2339.6-0532 is recently categorized as an black widow pulsar. It possesses a K-star companion orbiting at a period of 4.63 h that corresponds to an orbit radius of about 10(11) cm for a standard NS mass. Our optical observations utilizing OISTER show clear sinusoidal light curves at various wavelength covering Ks B band. Phase resolved SED precisely constrained the size of the companion star and temperature. X-ray spectra taken with Suzaku revealed steady soft X-ray excess below 1 keV energy range that may be originated in blackbody emission from the neutron surface. While In hard X-ray energy band the X-ray light curve shows double peak modulation synchronized with the orbital motion indicating that the hard X-ray may be from the surface of the companion star. To explain the hard X-ray behavior we examined a simple geometry and estimated the physical state of the pulsar wind at immediate vicinity of the light cylinder of the pulsar.

  12. The Megasecond Chandra X-Ray Visionary Project Observation of NGC 3115 (III): luminosity functions of LMXBs and dependence on stellar environments

    CERN Document Server

    Lin, Dacheng; Wong, Ka-wah; Jennings, Zachary G; Homan, Jeroen; Romanowsky, Aaron J; Strader, Jay; Brodie, Jean P; Sivakoff, Gregory R; Remillard, Ronald A

    2015-01-01

    We have studied the X-ray luminosity function (XLF) of low-mass X-ray binaries (LMXBs) in the nearby lenticular galaxy NGC 3115, using the Megasecond Chandra X-Ray Visionary Project Observation. With a total exposure time of ~1.1 Ms, we constructed the XLF down to a limiting luminosity of ~10^36 erg/s, much deeper than typically reached for other early-type galaxies. We found significant flattening of the overall LMXB XLF from dN/dL \\propto L^{-2.2\\pm0.4} above 5.5x10^37 erg/s to dN/dL \\propto L^{-1.0\\pm0.1} below it, though we could not rule out a fit with a higher break at ~1.6x10^38 erg/s. We also found evidence that the XLF of LMXBs in globular clusters (GCs) is overall flatter than that of field LMXBs. Thus our results for this galaxy do not support the idea that all LMXBs are formed in GCs. The XLF of field LMXBs seems to show spatial variation, with the XLF in the inner region of the galaxy being flatter than that in the outer region, probably due to contamination of LMXBs from undetected and/or disrup...

  13. NuSTAR Observations of the State Transition of Millisecond Pulsar Binary PSR J1023+0038

    CERN Document Server

    Tendulkar, Shriharsh P; An, Hongjun; Kaspi, Victoria M; Archibald, Anne M; Bassa, Cees; Bellm, Eric; Bogdanov, Slavko; Harrison, Fiona A; Hessels, Jason W T; Janssen, Gemma H; Lyne, Andrew G; Patruno, Alessandro; Stappers, Benjamin; Stern, Daniel; Tomsick, John A; Boggs, Steven E; Chakrabarty, Deepto; Christensen, Finn E; Craig, William W; Hailey, Charles A; Zhang, William

    2014-01-01

    We report NuSTAR observations of the millisecond pulsar - low mass X-ray binary (LMXB) transition system PSR J1023+0038 from June and October 2013, before and after the formation of an accretion disk around the neutron star. Between June 10-12, a few days to two weeks before the radio disappearance of the pulsar, the 3-79 keV X-ray spectrum was well fit by a simple power law with a photon index of Gamma=1.17 +/-0.08 (at 90% confidence) with a 3-79 keV luminosity of 7.4+/-0.4 x 10^32 erg/s. Significant orbital modulation was observed with a modulation fraction of 36+/-10%. During the October 19-21 observation, the spectrum is described by a softer power law (Gamma=1.66+/-0.06) with an average luminosity of 5.8+/-0.2 x 10^33 erg/s and a peak luminosity of ~1.2 x 10^34 erg/s observed during a flare. No significant orbital modulation was detected. The spectral observations are consistent with previous and current multi-wavelength observations and show the hard X-ray power law extending to 79 keV without a spectra...

  14. Precision astrometry of pulsars and other compact radio sources in the globular cluster M15

    CERN Document Server

    Kirsten, Franz; Freire, Paulo; Kramer, Michael; Rottmann, Helge; Campbell, Robert M

    2014-01-01

    The globular cluster (GC) M15 (NGC 7078) is host to at least eight pulsars and two low mass X-ray binaries (LMXBs) one of which is also visible in the radio regime. Here we present the results of a multi-epoch global very long baseline interferometry (VLBI) campaign aiming at i) measuring the proper motion of the known compact radio sources, ii) finding and classifying thus far undetected compact radio sources in the GC, and iii) detecting a signature of the putative intermediate mass black hole (IMBH) proposed to reside at the core of M15. We measure the sky motion in right ascension ($\\mu_{\\alpha}$) and declination ($\\mu_{\\delta}$) of the pulsars M15A and M15C and of the LMXB AC211 to be $(\\mu_{\\alpha},\\,\\mu_{\\delta})_{\\text{M15A}}=(-0.54\\pm0.14,\\,-4.33\\pm0.25)\\,$mas$\\,$yr$^{-1}$, $(\\mu_{\\alpha},\\,\\mu_{\\delta})_{\\text{M15C}}=(-0.75\\pm0.09,\\,-3.52\\pm0.13)\\,$mas$\\,$yr$^{-1}$, and $(\\mu_{\\alpha},\\,\\mu_{\\delta})_{\\text{AC211}}=(-0.46\\pm0.08,\\,-4.31\\pm0.20)\\,$mas$\\,$yr$^{-1}$, respectively. Based on these measur...

  15. Big game hunting in the andromeda galaxy: identifying And weighing black holes in low mass x-ray binaries

    Directory of Open Access Journals (Sweden)

    R. Barnard

    2004-01-01

    Full Text Available Hemos desarrollado una nueva t ecnica para identi car masas de agujeros negros en binarias de rayos X de baja masa y lo aplicamos a observaciones XMM-Newton de dos fuentes de rayos X en M31. En particular buscamos espectros de potencia de baja tasa de acreci on que son muy similares para todas LXMB, siendo la primaria un agujero negro o una estrella de neutrones. Las estrellas neutr onicas gal acticas, LXMB, presentan estos PDS distintivos a muy bajas luminosidades ( 1036 erg s1; mientras que los LMXB de agujeros negros los pueden presentar a luminosidades > 1038 erg s1. Siguiendo el trabajo de van der Klis (1994 asumimos la m axima tasa de acreci on (como una fracci on del l mite de Eddington para los PDS de baja tasa de acreci on que es constante para todas las LXMB, obteniendo un valor emp rico de 10% de Eddington. Hasta ahora descubrimos dos candidatos a binarias de agujero negro en M31 que presentan PDS de baja tasa de acreci on de hasta 3 1038 y 5 1037 erg s1. Si asumimos que el l mite es 5 1037 erg s1 probablemente tendr a un agujero negro como su primaria.

  16. The Hard X-ray Emission from Scorpius X-1 as Seen by INTEGRAL

    Science.gov (United States)

    Sturner, S. J.; Shrader, C. R.; Weidenspointner, G.

    2008-01-01

    We present the results of our hard X-ray and gamma-ray study of the LMXB Sco X-1 utilizing INTEGRAL data as well as contemporaneous RXTE PCA data. We have concentrated on investigating the hard X-ray spectral properties of Sco X-1 including the nature of the high-energy, nonthermal component of the spectrum and its possible correlations with the location of the source on the X-ray color-color diagram. We find that Sco X-1 has two distinct spectral when the 20-40 keV count rate is greater than 140 counts/second. One state is a hard state which exhibits a significant high-energy, powerlaw tail to the lower energy thermal spectrum. The other state shows no evidence for a powerlaw tail whatsoever. We found suggestive evidence for a correlation of these hard and soft high-energy states with the position of Sco X-1 on the low-energy X-ray color-color diagram.

  17. The Hard X-Ray Emission from Scorpius X-1 Seen by INTEGRAL

    Science.gov (United States)

    Sturner, Steve; Shrader, C. R.

    2008-01-01

    We present the results of our hard X-ray and gamma-ray study of the LMXB Sco X-1 utilizing INTEGRAL data as well as contemporaneous RXTE PCA data. We have investigated the hard X-ray spectral properties of Sco X-1 including the nature of the high-energy, nonthermal component and its possible correlations with the location of the source on the soft X-ray color-color diagram. We find that Sco X-1 follows two distinct spectral tracks when the 20-40 keV count rate is greater than 130 counts/second. One state is a hard state which exhibits a significant high-energy, powerlaw tail to the lower energy thermal spectrum. The other state shows a much less significant high-energy component. We found suggestive evidence for a correlation of these hard and soft high-energy states with the position of Sco X-1 on the low-energy X-ray color-color diagram. We have searched for similar behavior in 2 other Z sources: GX 17+2 and GX 5-1 with negative results.

  18. Discovery of periodic dips in the light curve of GX 13+1: the X-ray orbital ephemeris of the source

    CERN Document Server

    Iaria, R; Burderi, L; Riggio, A; D'Ai, A; Robba, N R

    2013-01-01

    The bright low-mass X-ray binary (LMXB) GX 13+1 is one of the most peculiar Galactic binary systems. A periodicity of 24.27 d with a formal statistical error of 0.03 d was observed in its power spectrum density obtained with RXTE All Sky Monitor (ASM) data spanning 14 years. Starting from a recent study, indicating GX 13+1 as a possible dipping source candidate, we systematically searched for periodic dips in the X-ray light curves of GX 13+1 from 1996 up to 2013 using RXTE/ASM, and MAXI data to determine for the first time the X-ray orbital ephemeris of GX 13+1. We searched for a periodic signal in the ASM and MAXI light curves, finding a common periodicity of 24.53 d. We folded the 1.3-5 keV and 5-12.1 keV ASM light curves and the 2-4 and 4-10 keV MAXI light curves at the period of 24.53 d finding a periodic dip. To refine the value of the period we used the timing technique dividing the ASM light curve in eight intervals and the MAXI light curve in two intervals, obtaining four and two dip arrival times fr...

  19. Effects of variability of X-ray binaries on the X-ray luminosity functions of Milky Way

    CERN Document Server

    Islam, Nazma

    2016-01-01

    The X-ray luminosity functions of galaxies have become a useful tool for population studies of X-ray binaries in them. The availability of long term light-curves of X-ray binaries with the All Sky X-ray Monitors opens up the possibility of constructing X-ray luminosity functions, by also including the intensity variation effects of the galactic X-ray binaries. We have constructed multiple realizations of the X-ray luminosity functions (XLFs) of Milky Way, using the long term light-curves of sources obtained in the 2-10 keV energy band with the RXTE-ASM. The observed spread seen in the value of slope of both HMXB and LMXB XLFs are due to inclusion of variable luminosities of X-ray binaries in construction of these XLFs as well as finite sample effects. XLFs constructed for galactic HMXBs in the luminosity range 10^{36} - 10^{39} erg/sec is described by a power-law model with a mean power-law index of -0.48 and a spread due to variability of HMXBs as 0.19. XLFs constructed for galactic LMXBs in the luminosity r...

  20. The formation of low-mass helium white dwarfs orbiting pulsars: Evolution of low-mass X-ray binaries below the bifurcation period

    CERN Document Server

    Istrate, Alina; Langer, Norbert

    2014-01-01

    Millisecond pulsars (MSPs) are generally believed to be old neutron stars (NSs) which have been spun up to high rotation rates via accretion of matter from a companion star in a low-mass X-ray binary (LMXB). However, many details of this recycling scenario remain to be understood. Here we investigate binary evolution in close LMXBs to study the formation of radio MSPs with low-mass helium white dwarf companions (He WDs) in tight binaries with orbital periods P_orb = 2-9 hr. In particular, we examine: i) if such observed systems can be reproduced from theoretical modelling using standard prescriptions of orbital angular momentum losses (i.e. with respect to the nature and the strength of magnetic braking), ii) if our computations of the Roche-lobe detachments can match the observed orbital periods, and iii) if the correlation between WD mass and orbital period (M_WD, P_orb) is valid for systems with P_orb < 2 days. Numerical calculations with a detailed stellar evolution code were used to trace the mass-tra...

  1. Low Mass X-Ray Binaries in the Inner Galaxy: Implications for Millisecond Pulsars and the GeV Excess

    Energy Technology Data Exchange (ETDEWEB)

    Haggard, Daryl; Heinke, Craig; Hooper, Dan; Linden, Tim

    2017-01-10

    If millisecond pulsars (MSPs) are responsible for the excess gamma-ray emission observed from the region surrounding the Galactic Center, the same region should also contain a large population of low-mass X-ray binaries (LMXBs). In this study, we compile and utilize a sizable catalog of LMXBs observed in the the Milky Way's globular cluster system and in the Inner Galaxy, as well as the gamma-ray emission observed from globular clusters, to estimate the flux of gamma rays predicted from MSPs in the Inner Galaxy. From this comparison, we conclude that only up to $\\sim$4-23% of the observed gamma-ray excess is likely to originate from MSPs. This result is consistent with, and more robust than, previous estimates which utilized smaller samples of both globular clusters and LMXBs. If MSPs had been responsible for the entirety of the observed excess, INTEGRAL should have detected $\\sim$$10^3$ LMXBs from within a $10^{\\circ}$ radius around the Galactic Center, whereas only 42 LMXBs (and 46 additional LMXB candidates) have been observed.

  2. The Evolution of Normal Galaxy X-ray Emission Through Cosmic History: Constraints from the 6 Ms Chandra Deep Field-South

    CERN Document Server

    Lehmer, B D; Mineo, S; Brandt, W N; Eufrasio, R T; Fragos, T; Hornschemeier, A E; Luo, B; Xue, Y Q; Bauer, F E; Gilfanov, M; Ranalli, P; Schneider, D P; Shemmer, O; Tozzi, P; Trump, J R; Vignali, C; Wang, J -X; Yukita, M; Zezas, A

    2016-01-01

    We present measurements of the evolution of normal-galaxy X-ray emission from $z \\approx$ 0-7 using local galaxies and galaxy samples in the 6 Ms Chandra Deep Field-South (CDF-S) survey. The majority of the CDF-S galaxies are observed at rest-frame energies above 2 keV, where the emission is expected to be dominated by X-ray binary (XRB) populations; however, hot gas is expected to provide small contributions to the observed- frame < 1 keV emission at $z < 1$. We show that a single scaling relation between X-ray luminosity ($L_{\\rm X}$) and star-formation rate (SFR) is insufficient for characterizing the average X-ray emission at all redshifts. We establish that scaling relations involving not only SFR, but also stellar mass ($M_\\star$) and redshift, provide significantly improved characterizations of the average X-ray emission from normal galaxy populations at $z \\approx$ 0-7. We further provide the first empirical constraints on the redshift evolution of X-ray emission from both low-mass XRB (LMXB) an...

  3. On the Fe K absorption - accretion state connection in the Galactic center neutron star X-ray binary AX J1745.6-2901

    CERN Document Server

    Ponti, G; Munoz-Darias, T; DeMarco, B; Dwelly, T; Fender, R P; Nandra, K; Rea, N; Mori, K; Haggard, D; Heinke, C O; Degenaar, N; Aramaki, T; Clavel, M; Goldwurm, A; Hailey, C J; Israel, G L; Morris, M R; Rushton, A; Terrier, R

    2014-01-01

    AX J1745.6-2901 is a high-inclination (eclipsing) neutron star Low Mass X-ray Binary (LMXB) located less than ~1.5 arcmin from Sgr A*. Ongoing monitoring campaigns have targeted Sgr A* frequently and these observations also cover AX J1745.6-2901. We present here an X-ray analysis of AX J1745.6-2901 using a large dataset of 38 XMM-Newton observations, including eleven which caught AX J1745.6-2901 in outburst. Fe K absorption is clearly seen when AX J1745.6-2901 is in the soft state, but disappears during the hard state. The variability of these absorption features does not appear to be due to changes in the ionizing continuum. The small Kalpha/Kbeta ratio of the equivalent widths of the Fe xxv and Fe xxvi lines suggests that the column densities and turbulent velocities of the absorbing ionised plasma are in excess of N_H ~ 10^23 cm^-2 and v_turb >~ 500 km s^-1. These findings strongly support a connection between the wind (Fe K absorber) and the accretion state of the binary. These results reveal strong simil...

  4. Confronting models for the high-frequency QPOs with Lense-Thirring precession

    CERN Document Server

    Stefanov, Ivan Zh

    2014-01-01

    Quasiperiodic oscillations (QPOs) have been observed in the power-density spectra of some low-mass X-ray binaries(LMXB) containing a black hole. The two major groups of QPOs -- low-frequency and high-frequency -- have rather different properties. That is why they are usually studied separately. In the literature one can find a large number of models for the high-frequency QPOs but not so many for the low-frequency ones. HF QPOs have attracted significant research efforts due to their potential to provide indispensable information for the properties of the black hole, for its accretion disc and for strong field gravity in general. However, in order to interpret the data for the HF QPOs of the observed objects we have to fix a model. Here we propose a simple test which could allow us to sift the models. The test is based on five rather general assumptions concerning the nature of the central object in black-hole binaries and the mechanism for the generation of the LF QPOs observed in the PDS of such objects. In...

  5. Faint X-ray Sources in the Globular Cluster Terzan 5

    CERN Document Server

    Heinke, C O; Cohn, H N; Lugger, P M; Grindlay, J E; Pooley, D; Lewin, W H G

    2006-01-01

    We report our analysis of a Chandra X-ray observation of the rich globular cluster Terzan 5, in which we detect 50 sources to a limiting 1.0-6 keV X-ray luminosity of 3*10^{31} ergs/s within the half-mass radius of the cluster. Thirty-three of these have L_X>10^{32} ergs/s, the largest number yet seen in any globular cluster. In addition to the quiescent low-mass X-ray binary (LMXB, identified by Wijnands et al.), another 12 relatively soft sources may be quiescent LMXBs. We compare the X-ray colors of the harder sources in Terzan 5 to the Galactic Center sources studied by Muno and collaborators, and find the Galactic Center sources to have harder X-ray colors, indicating a possible difference in the populations. We cannot clearly identify a metallicity dependence in the production of low-luminosity X-ray binaries in Galactic globular clusters, but a metallicity dependence of the form suggested by Jordan et al. for extragalactic LMXBs is consistent with our data.

  6. The optical ephemeris and X-ray variability of 4U 1735-44 (V926 Sco)

    CERN Document Server

    Giles, A B

    2012-01-01

    Optical observations of the low mass X-ray binary 4U 1735-44 were obtained during 1997-2007 and combined with earlier published observations from 1984-1993 to refine the ephemeris for the system. The linear fit for the time of maximum optical light has the ephemeris HJD = 2445904.0494(90) + [ N x 0.19383222(29)] with a value of chi^2 = 253.5$ for 16 dof and a scatter about phase zero of sigma = 0.061. The new data reconciles the discrepancy between the previous ephemeris and the more recent spectral ephemeris based on emission from the companion star which defined the systems true dynamical phase zero. The optical maximum for 4U 1735-44 now occurs at spectral phase 0.47 \\pm 0.05 and thus supports the classic model for an LMXB system. Our data further supports the standard model in several ways. The mean optical flux shows a positive correlation with the RXTE ASM X-ray flux, the relative increases suggesting that the non-X-ray induced optical flux from the companion is < 14 percent of the total optical ligh...

  7. The X-ray spectral evolution of Cyg X-2 in the framework of bulk Comptonization

    CERN Document Server

    Farinelli, R; Landi, R; Titarchuk, L

    2009-01-01

    We used the newly developed thermal plus bulk Comptonization model comptb to investigate the spectral evolution of the neutron star LMXB Cyg X-2 along its Z-track. We selected a single source in order to trace in a quantitative way the evolution of the physical parameters of the model. We analyzed archival broad-band BeppoSAX spectra of Cyg X-2. Five broad-band spectra have been newly extracted according to the source position in the Z-track described in the colour-colour and colour-intensity diagrams. We have fitted the spectra of the source with two comptb components. The first one, with bulk parameter delta=0, dominates the overall source broad-band spectrum and its origin is related to thermal upscattering (Comptonization) of cold seed photons off warm electrons in high-opacity enviroment. We attribute the origin of these seed photons to the part of the disk which illuminates the outer coronal region (transition layer) located between the accretion disk itself and the neutron star surface. This thermal co...

  8. Black holes in stellar-mass binary systems: expiating original spin?

    CERN Document Server

    King, Andrew

    2016-01-01

    We investigate systematically whether accreting black hole systems are likely to reach global alignment of the black hole spin and its accretion disc with the binary plane. In low-mass X-ray binaries (LMXBs) there is only a modest tendency to reach such global alignment, and it is difficult to achieve fully: except for special initial conditions we expect misalignment of the spin and orbital planes by ~1 radian for most of the LMXB lifetime. The same is expected in high-mass X-ray binaries (HMXBs). A fairly close approach to global alignment is likely in most stellar-mass ultraluminous X-ray binary systems (ULXs) where the companion star fills its Roche lobe and transfers on a thermal timescale to a black hole of lower mass. These systems are unlikely to show orbital eclipses, as their emission cones are close to the hole's spin axis. This offers a potential observational test, as models for ULXs invoking intermediate-mass black holes do predict eclipses for ensembles of > ~10 systems. Recent observational wo...

  9. Probing the effects of a thermonuclear X-ray burst on the neutron star accretion flow with NuSTAR

    CERN Document Server

    Degenaar, N; Chakrabarty, D; Kara, E; Altamirano, D; Miller, J M; Fabian, A C

    2016-01-01

    Observational evidence has been accumulating that thermonuclear X-ray bursts ignited on the surface of neutron stars influence the surrounding accretion flow. Here, we exploit the excellent sensitivity of NuSTAR up to 79 keV to analyze the impact of an X-ray burst on the accretion emission of the neutron star LMXB 4U 1608-52. The ~200 s long X-ray burst occurred during a hard X-ray spectral state, and had a peak intensity of ~30-50 per cent of the Eddington limit with no signs of photospheric radius expansion. Spectral analysis suggests that the accretion emission was enhanced up to a factor of ~5 during the X-ray burst. We also applied a linear unsupervised decomposition method, namely non-negative matrix factorization (NMF), to study this X-ray burst. We find that the NMF performs well in characterizing the evolution of the burst emission and is a promising technique to study changes in the underlying accretion emission in more detail than is possible through conventional spectral fitting. For the burst of ...

  10. INTEGRAL observation of renewed activity from 4U 1608-522

    DEFF Research Database (Denmark)

    Ishibashi, W.; Ferrigno, C.; Sánchez-Fernández, C.;

    2010-01-01

    for a total exposure time of 8.8 ks, can be fit by using an absorbed power-law model. We fixed the absorption column density at 1.2E22 cm² and obtained a power-law photon index of 2.8+/-0.4. The estimated source flux in the 3-10 keV energy band is 3.3E-10 ergs/cm²/s. During the whole observation time......, the source was not detected by IBIS/ISGRI. We derive an upper limit (5-sigma) on the X-ray flux of 5-10 mCrab in the 20-40 keV band. INTEGRAL is currently observing the field of GX 339-4 (March 4th-6th) and will continue monitoring of the inner Galactic Disk until the end of March. 4U 1608......On 3 March 2010 SuperAGILE detected an X-ray burst from the LMXB 4U 1608-522 (Atel #2461). Confirmation of the renewed activity of this transient source was reported by MAXI/GSC (Atel #2462). 4U1608-522 was in the IBIS/ISGRI and JEMX field of view during several observations between 2010-Feb-23 06...

  11. Chandra Observations of the Faintest Low-Mass X-ray Binaries

    CERN Document Server

    Wilson, C A; Kouveliotou, C; Jonker, P G; Van der Klis, M; Lewin, W H G; Belloni, T; Méndez, M; Wilson, Colleen. A.; Patel, Sandeep K.; Kouveliotou, Chryssa; Jonker, Peter G.; Klis, Michiel van der; Lewin, Walter H.G; Belloni, Tomaso; Mendez, Mariano

    2003-01-01

    There exists a group of persistently faint galactic X-ray sources that, based on their location in the galaxy, high L_x/L_opt, association with X-ray bursts, and absence of low frequency X-ray pulsations, are thought to be low-mass X-ray binaries (LMXBs). We present results from Chandra observations for eight of these systems: 4U 1708-408, 2S 1711-339, KS 1739-304, SLX 1735-269, GRS 1736-297, SLX 1746-331, 1E 1746.7-3224, and 4U 1812-12. Locations for all sources, excluding GRS 1736-297, SLX 1746-331, and KS 1739-304 (which were not detected) were improved to 0.6" error circles (90% confidence). Our observations support earlier findings of transient behavior of GRS 1736-297, KS 1739-304, SLX 1746-331, and 2S 1711-339 (which we detect in one of two observations). Energy spectra for 4U 1708-408, 2S 1711-339, SLX 1735-269, 1E 1746.7-3224, and 4U 1812-12 are hard, with power law indices typically 1.4-2.1, which are consistent with typical faint LMXB spectra.

  12. Black holes in stellar-mass binary systems: expiating original spin?

    Science.gov (United States)

    King, Andrew; Nixon, Chris

    2016-10-01

    We investigate systematically whether accreting black hole systems are likely to reach global alignment of the black hole spin and its accretion disc with the binary plane. In low-mass X-ray binaries (LMXBs), there is only a modest tendency to reach such global alignment, and it is difficult to achieve fully: except for special initial conditions, we expect misalignment of the spin and orbital planes by ˜1 rad for most of the LMXB lifetime. The same is expected in high-mass X-ray binaries. A fairly close approach to global alignment is likely in most stellar-mass ultraluminous X-ray binary systems (ULXs) where the companion star fills its Roche lobe and transfers mass on a thermal or nuclear time-scale to a black hole of lower mass. These systems are unlikely to show orbital eclipses, as their emission cones are close to the hole's spin axis. This offers a potential observational test, as models for ULXs invoking intermediate-mass black holes do predict eclipses for ensembles of ≳ 10 systems. Recent observational work shows that eclipses are either absent or extremely rare in ULXs, supporting the picture that most ULXs are stellar-mass binaries with companion stars more massive than the accretor.

  13. Early Phase Detection and Coverage of Extragalactic and Galactic Black Hole X-ray Transients with the SKA

    CERN Document Server

    Yu, Wenfei; Yan, Zhen; Zhang, Wenda

    2015-01-01

    SKA's large field of view and high sensitivity at low frequencies will provide almost a complete coverage of the very early rising phase of extragalactic and Galactic transients which undergo a flare or outburst due to an abrupt accretion onto either supermassive (such as tidal disruption events, TDEs) or stellar mass black hole transients (such as black hole LMXB) , when their broadband emission is supposed to be jet-dominated at low luminosities, allowing SKA to be the first facility to make source discoveries and to send out alerts for follow-up ground or space observations as compared with the sensitivity of future X-ray wide-field-view monitoring. On the other hand, due to extremely large rate-of-change in the mass accretion rate during the rising phase of TDE flares or transient outbursts, SKA will be able to cover an extremely large range of the mass accretion rate as well as its rate-of-change not accessible with observations in persistent black hole systems, which will shape our understanding of disk...

  14. A long-term optical - X-ray correlation in 4U 1957+11

    CERN Document Server

    Russell, D M; Roche, P; Clark, J S; Breedt, E; Fender, R P

    2009-01-01

    [abridged] Three years of optical monitoring of the low-mass X-ray binary (LMXB) 4U 1957+11 is presented. The source was observed in V, R and i-bands using the Faulkes Telescopes North and South. The light curve is dominated by long-term variations which are correlated (at the > 3 sigma level) with the RXTE ASM soft X-ray flux. The variations span one magnitude in all three filters. We find no evidence for periodicities in our light curves, contrary to a previous short-timescale optical study in which the flux varied on a 9.3-hour sinusoidal period by a smaller amplitude. The optical spectral energy distribution is blue and typical of LMXBs in outburst, as is the power law index of the correlation beta = 0.5, where F_{nu,OPT} propto F_X^beta. The discrete cross-correlation function reveals a peak at an X-ray lag of 2 - 14 days, which could be the viscous timescale. However, adopting the least squares method the strongest correlation is at a lag of 0 +/- 4 days, consistent with X-ray reprocessing on the surfac...

  15. Frontiers in nuclear astrophysics

    Science.gov (United States)

    Bertulani, C. A.; Kajino, T.

    2016-07-01

    The synthesis of nuclei in diverse cosmic scenarios is reviewed, with a summary of the basic concepts involved before a discussion of the current status in each case is made. We review the physics of the early universe, the proton to neutron ratio influence in the observed helium abundance, reaction networks, the formation of elements up to beryllium, the inhomogeneous Big Bang model, and the Big Bang nucleosynthesis constraints on cosmological models. Attention is paid to element production in stars, together with the details of the pp chain, the pp reaction, 3He formation and destruction, electron capture on 7Be, the importance of 8B formation and its relation to solar neutrinos, and neutrino oscillations. Nucleosynthesis in massive stars is also reviewed, with focus on the CNO cycle and its hot companion cycle, the rp-process, triple- α capture, and red giants and AGB stars. The stellar burning of carbon, neon, oxygen, and silicon is presented in a separate section, as well as the slow and rapid nucleon capture processes and the importance of medium modifications due to electrons also for pycnonuclear reactions. The nucleosynthesis in cataclysmic events such as in novae, X-ray bursters and in core-collapse supernovae, the role of neutrinos, and the supernova radioactivity and light-curve is further discussed, as well as the structure of neutron stars and its equation of state. A brief review of the element composition found in cosmic rays is made in the end.

  16. Surveying the skies how astronomers map the universe

    CERN Document Server

    Wynn-Williams, Gareth

    2016-01-01

    Since the time of Galileo, astronomy has been driven by technological innovation. With each major advance has come the opportunity and enthusiasm to survey the sky in a way that was not possible before. It is these surveys of discovery that are the subject of this book. In the first few chapters the author discusses what astronomers learned from visible-light surveys, first with the naked eye, then using telescopes in the seventeenth century, and photography in the nineteenth century. He then moves to the second half of the twentieth century when the skies started to be swept by radio, infrared, ultraviolet, x-ray and gamma ray telescopes, many of which had to be flown in satellites above the Earth’s atmosphere. These surveys led to the discovery of pulsars, quasars, molecular clouds, protostars, bursters, and black holes. He then returns to Earth to describe several currently active large-scale projects that methodically collect images, photometry and spectra that are then stored in vast publicly-accessibl...

  17. Burst-properties as a function of mass accretion rate in GX 3+1

    CERN Document Server

    Den Hartog, P; Kuulkers, E; Cornelisse, R; Heisse, J; Bazzano, A; Cocchi, M; Natalucci, L; Ubertini, P

    2003-01-01

    GX 3+1 is a low-mass X-ray binary that is persistently bright since its discovery in 1964. It was found to be an X-ray burster twenty years ago proving that the compact object in this system is a neutron star. The burst rate is so low that only 18 bursts were reported prior to 1996. The Wide Field Cameras on BeppoSAX have, through a dedicated monitoring program on the Galactic center region, increased the number of X-ray bursts from GX 3+1 by 61. Since GX 3+1 exhibits a slow (order of years) modulation in the persistent flux of about 50%, these observations opens up the unique possibility to study burst properties as a function of mass accretion rate for very low burst rates. This is the first time that bursts are detected from GX 3+1 in the high state. From the analysis we learn that all bursts are short with e-folding decay times smaller than 10 s. Therefore, all bursts are due to unstable helium burning. Furthermore, the burst rate drops sixfold in a fairly narrow range of 2-20 keV flux; we discuss possibl...

  18. DISK-RELATED BURSTS AND FADES IN YOUNG STARS

    Energy Technology Data Exchange (ETDEWEB)

    Findeisen, Krzysztof; Hillenbrand, Lynne; Levitan, David; Sesar, Branimir [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Ofek, Eran [Benoziyo Center for Astrophysics, Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Laher, Russ; Surace, Jason, E-mail: krzys@astro.caltech.edu, E-mail: lah@astro.caltech.edu [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States)

    2013-05-01

    We present first results from a new, multiyear, time domain survey of young stars in the North America Nebula complex using the Palomar Transient Factory. Our survey is providing an unprecedented view of aperiodic variability in young stars on timescales of days to years. The analyzed sample covers R{sub PTF} Almost-Equal-To 13.5-18 and spans a range of mid-infrared color, with larger-amplitude optical variables (exceeding 0.4 mag root mean squared) more likely to have mid-infrared evidence for circumstellar material. This paper characterizes infrared excess stars with distinct bursts above or fades below a baseline of lower-level variability, identifying 41 examples. The light curves exhibit a remarkable diversity of amplitudes, timescales, and morphologies, with a continuum of behaviors that cannot be classified into distinct groups. Among the bursters, we identify three particularly promising sources that may represent theoretically predicted short-timescale accretion instabilities. Finally, we find that fading behavior is approximately twice as common as bursting behavior on timescales of days to years, although the bursting and fading duty cycle for individual objects often varies from year to year.

  19. Disk-Related Bursts and Fades in Young Stars

    CERN Document Server

    Findeisen, Krzysztof; Ofek, Eran; Levitan, David; Sesar, Branimir; Laher, Russ; Surace, Jason

    2013-01-01

    We present first results from a new, multiyear, time domain survey of young stars in the North America Nebula complex using the Palomar Transient Factory. Our survey is providing an unprecedented view of aperiodic variability in young stars on timescales of days to years. The analyzed sample covers R_PTF = 13.5-18 and spans a range of mid-infrared color, with larger-amplitude optical variables (exceeding 0.4 mag root-mean-squared) more likely to have mid-infrared evidence for circumstellar material. This paper characterizes infrared excess stars with distinct bursts above or fades below a baseline of lower-level variability, identifying 41 examples. The light curves exhibit a remarkable diversity of amplitudes, timescales, and morphologies, with a continuum of behaviors that can not be classified into distinct groups. Among the bursters, we identify three particularly promising sources that may represent theoretically predicted short-timescale accretion instabilities. Finally, we find that fading behavior is ...

  20. Rotational effects in thermonuclear Type I Bursts: equatorial crossing and directionality of flame spreading

    CERN Document Server

    Cavecchi, Yuri; Levin, Yuri; Braithwaite, Jonathan

    2014-01-01

    In a previous study on thermonuclear (Type I) Bursts on accreting neutron stars we addressed and demonstrated the importance of the effects of rotation, through the Coriolis force, on the propagation of the burning flame. However, that study only analysed cases of longitudinal propagation, where the Coriolis force coefficient $2\\Omega\\cos\\theta$ was constant. In this paper, we study the effects of rotation on propagation in the meridional (latitudinal) direction, where the Coriolis force changes from its maximum at the poles to zero at the equator. We find that the zero Coriolis force at the equator, while affecting the structure of the flame, does not prevent its propagation from one hemisphere to another. We also observe structural differences between the flame propagating towards the equator and that propagating towards the pole, the second being faster. In the light of the recent discovery of the low spin frequency of burster IGR~J17480-2446 rotating at 11 Hz (for which Coriolis effects should be negligib...

  1. INTEGRAL spectral variability study of the atoll 4U 1820-30: first detection of hard X-ray emission

    CERN Document Server

    Tarana, A; Ubertini, P; Zdziarski, A A; Tarana, Antonella; Bazzano, Angela; Ubertini, Pietro; Zdziarski, Andrzej A.

    2006-01-01

    We study the 4-200 keV spectral and temporal behaviour of the low mass X-ray binary 4U 1820-30 with INTEGRAL during 2003-2005. This source as been observed in both the soft (banana) and hard (island) spectral states. A high energy tail, above 50 keV, in the hard state has been observed for the first time. This places the source in the category of X-ray bursters showing high-energy emission. The tail can be modeled as a soft power law component, with the photon index of ~2.4, on top of thermal Comptonization emission from a plasma with the electron temperature of kT_e~6 keV and optical depth of \\tau~4. Alternatively, but at a lower goodness of the fit, the hard-state broad band spectrum can be accounted for by emission from a hybrid, thermal-nonthermal, plasma. During this monitoring the source spent most of the time in the soft state, usual for this source, and the >~4 keV spectra are represented by thermal Comptonization with kT_e~3 keV and \\tau~6-7.

  2. Following the Colour of the Low Mass X-ray Binary 4U 1820-30 with INTEGRAL

    CERN Document Server

    Tarana, A; Ubertini, P; Zdziarski, A A; Federici, M; Tarana, Antonella; Bazzano, Angela; Ubertini, Pietro

    2006-01-01

    The 4-200 keV spectral and temporal behaviour of the low mass X-ray binary 4U 1820-30 has been studied with INTEGRAL during 2003-2005. This source as been observed in both the soft (banana) and hard (island) spectral states. A high energy tail above 50 keV in the hard state has been revealed for the first time. This places the source in the category of X-ray bursters showing high-energy emission. The tail can be modeled as a soft power law component, with the photon index of ~ 2.4, on top of thermal Comptonization emission from a plasma with the electron temperature of kT_e ~ 6 keV and optical depth of $\\tau ~ 4. Alternatively, but at a lower goodness of the fit, the hard-state broad band spectrum can be accounted for by emission from a hybrid, thermal-nonthermal, plasma. During the observations, the source spent most of the time in the soft state, as previously reported and the $\\ge$4 keV spectra can be represented by thermal Comptonization with kT_e ~ 3 keV and $\\tau ~ 6-7.

  3. GRB Hubble diagram and constraints on a \\Lambda (t)CDM model

    CERN Document Server

    Velten, Hermano; Carneiro, Saulo

    2012-01-01

    In previous papers, a cosmological model with constant-rate particle creation and vacuum term decaying linearly with the Hubble parameter was shown to lead to a good concordance when tested against precise observations: the position of the first peak in the spectrum of anisotropies of the cosmic microwave background (CMB), the Hubble diagram for supernovas of type Ia (SNe Ia), the distribution of large-scale structures (LSS) and the distance to the baryon acoustic oscillations (BAO). That model has the same number of parameters as the spatially flat standard model and seems to alleviate some observational/theoretical tensions appearing in the later. In this letter we complement those tests with 109 gamma ray bursters (GRB), 59 of them with redshifts above z=1.4, which permits to extend the Hubble diagram to redshifts up to z ~ 8. For the calibration of the 50 GRBs with z<1.4 we use the 288 supernovas of the Sloan Digital Sky Survey (SDSS) project, calibrated with the MLCS2k2 fitter, less model-dependent th...

  4. Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars.

    Science.gov (United States)

    Castro-Tirado, A J; de Ugarte Postigo, A; Gorosabel, J; Jelínek, M; Fatkhullin, T A; Sokolov, V V; Ferrero, P; Kann, D A; Klose, S; Sluse, D; Bremer, M; Winters, J M; Nuernberger, D; Pérez-Ramírez, D; Guerrero, M A; French, J; Melady, G; Hanlon, L; McBreen, B; Leventis, K; Markoff, S B; Leon, S; Kraus, A; Aceituno, F J; Cunniffe, R; Kubánek, P; Vítek, S; Schulze, S; Wilson, A C; Hudec, R; Durant, M; González-Pérez, J M; Shahbaz, T; Guziy, S; Pandey, S B; Pavlenko, L; Sonbas, E; Trushkin, S A; Bursov, N N; Nizhelskij, N A; Sánchez-Fernández, C; Sabau-Graziati, L

    2008-09-25

    Magnetars are young neutron stars with very strong magnetic fields of the order of 10(14)-10(15) G. They are detected in our Galaxy either as soft gamma-ray repeaters or anomalous X-ray pulsars. Soft gamma-ray repeaters are a rare type of gamma-ray transient sources that are occasionally detected as bursters in the high-energy sky. No optical counterpart to the gamma-ray flares or the quiescent source has yet been identified. Here we report multi-wavelength observations of a puzzling source, SWIFT J195509+261406. We detected more than 40 flaring episodes in the optical band over a time span of three days, and a faint infrared flare 11 days later, after which the source returned to quiescence. Our radio observations confirm a Galactic nature and establish a lower distance limit of approximately 3.7 kpc. We suggest that SWIFT J195509+261406 could be an isolated magnetar whose bursting activity has been detected at optical wavelengths, and for which the long-term X-ray emission is short-lived. In this case, a new manifestation of magnetar activity has been recorded and we can consider SWIFT J195509+261406 to be a link between the 'persistent' soft gamma-ray repeaters/anomalous X-ray pulsars and dim isolated neutron stars.

  5. Long Type I X-ray Bursts and Neutron Star Interior Physics

    CERN Document Server

    Cumming, A; in 't Zand, J J M; Page, D; Cumming, Andrew; Macbeth, Jared; Page, Dany

    2005-01-01

    Superbursts are very energetic Type I X-ray bursts discovered in recent years by long term monitoring of X-ray bursters, believed to be due to unstable ignition of carbon in the deep ocean of the neutron star. A number of "intermediate duration" bursts have also been observed, probably associated with ignition of a thick helium layer. We investigate the sensitivity of these long X-ray bursts to the thermal profile of the neutron star crust and core. We first compare cooling models of superburst lightcurves with observations, and derive constraints on the ignition mass and energy release, and then calculate ignition models for superbursts and pure helium bursts, and compare to observations. The superburst lightcurves and ignition models imply that the carbon mass fraction is approximately 20% or greater in the fuel layer, constraining models of carbon production. However, the most important result is that when Cooper pairing neutrino emission is included in the crust, the temperature is too low to support unst...

  6. Extracellular calcium modulates persistent sodium current-dependent burst-firing in hippocampal pyramidal neurons.

    Science.gov (United States)

    Su, H; Alroy, G; Kirson, E D; Yaari, Y

    2001-06-15

    The generation of high-frequency spike bursts ("complex spikes"), either spontaneously or in response to depolarizing stimuli applied to the soma, is a notable feature in intracellular recordings from hippocampal CA1 pyramidal cells (PCs) in vivo. There is compelling evidence that the bursts are intrinsically generated by summation of large spike afterdepolarizations (ADPs). Using intracellular recordings in adult rat hippocampal slices, we show that intrinsic burst-firing in CA1 PCs is strongly dependent on the extracellular concentration of Ca(2+) ([Ca(2+)](o)). Thus, lowering [Ca(2+)](o) (by equimolar substitution with Mn(2+) or Mg(2+)) induced intrinsic bursting in nonbursters, whereas raising [Ca(2+)](o) suppressed intrinsic bursting in native bursters. The induction of intrinsic bursting by low [Ca(2+)](o) was associated with enlargement of the spike ADP. Low [Ca(2+)](o)-induced intrinsic bursts and their underlying ADPs were suppressed by drugs that reduce the persistent Na(+) current (I(NaP)), indicating that this current mediates the slow burst depolarization. Blocking Ca(2+)-activated K(+) currents with extracellular Ni(2+) or intracellular chelation of Ca(2+) did not induce intrinsic bursting. This and other evidence suggest that lowering [Ca(2+)](o) may induce intrinsic bursting by augmenting I(NaP). Because repetitive neuronal activity in the hippocampus is associated with marked decreases in [Ca(2+)](o), the regulation of intrinsic bursting by extracellular Ca(2+) may provide a mechanism for preferential recruitment of this firing mode during certain forms of hippocampal activation.

  7. The Equation of State from Observed Masses and Radii of Neutron Stars

    CERN Document Server

    Steiner, Andrew W; Brown, Edward F

    2010-01-01

    We determine an empirical dense matter equation of state (EOS) from a heterogeneous set of seven neutron stars with well-determined distances. Our dataset consists of the three type I X-ray bursters with photospheric radius expansion studied by Ozel et al., along with thermal emission from three transient low-mass X-ray binaries and the isolated cooling neutron star, RX J1856-3754. We critically assess the mass and radius determinations from the X-ray bursts and show explicitly how the systematic uncertainties, such as the radius of the photosphere at touchdown, affect the best-fit masses and radii. As a result of including these uncertainties, our mass and radius constraints are weaker than previously found. Nevertheless, when combined with radius constraints from neutron star transients and the isolated neutron star RX J1856-3754, we do find significant constraints on the mass-radius relation for neutron stars, and hence on the pressure-density relation of dense matter. We introduce a parameterized EOS and ...

  8. The Bursting Behavior of 4U 1728-34: Parameters of a Neutron Star and Geometry of a NS-disk system

    Science.gov (United States)

    Shaposhnikov, Nickolai; Titarchuk, Lev; Haber, Frank

    2003-01-01

    We analyze a set of Type I X-ray bursts from the low mass X-ray binary 4U 1728-34, observed with Rossi X-ray Timing Explorer (RXTE). We infer the dependence of the neutron star (NS) mass and radius with respect to the assumed distance to the system using an analytical model of X-ray burst spectral formation. The model behavior clearly indicates that the burster atmosphere is helium-dominated. Our results strongly favor the soft equation of state (EOS) of NS for 4U 1728-34. We find that distance to the source should be within 4.5-5.0 kpc range. We obtain rather narrow constrains for the NS radius in 8.7-9.7 km range and interval 1.2-1.6 Ma for NS mass for this particular distance range. We uncover a temporal behavior of red-shift corrected burst flux for the radial expansion episodes and we put forth a dynamical evolution scenario for the NS accretion disk geometry during which an expanded envelope affects the accretion disk and increases the area of the neutron star exposed to the Earth observer. In the framework of this scenario we provide a new method for the estimation of the inclination angle which leads to the value of approximately 50 degrees for 4U 1728-34.

  9. The Bursting Behavior of 4U 1728-34: Parameters of a Neutron Star and Geometry of a NS-disk system

    CERN Document Server

    Shaposhnikov, N; Haberl, F; Shaposhnikov, Nickolai; Titarchuk, Lev; Haberl, Frank

    2003-01-01

    We analyze a set of Type I X-ray bursts from the low mass X-ray binary 4U 1728 -34, observed with Rossi X-ray Timing Explorer (RXTE). and we implement an analytical model of X-ray spectral formation in the neutron star (NS) atmosphere during a burst. We infer the dependence of the neutron star mass and radius with respect to the assumed distance to the system using an analytical model of X-ray burst spectral formation. The model behavior clearly indicates that the burster atmosphere is helium-dominated. Our results strongly favor the soft equation of state (EOS) of NS for 4U 1728-34. We find that distance to the source should be within 4.5-5.0 kpc range. We obtain rather narrow constrains for the NS radius in 8.7-9.7 km range and interval 1.2-1.6 solar masses for NS mass for this particular distance range. We uncover a temporal behavior of red-shift corrected burst flux for the radial expansion episodes and we put forth a dynamical evolution scenario for the NS--accretion disk geometry during which an expande...

  10. SKYNET: an efficient and robust neural network training tool for machine learning in astronomy

    Science.gov (United States)

    Graff, Philip; Feroz, Farhan; Hobson, Michael P.; Lasenby, Anthony

    2014-06-01

    We present the first public release of our generic neural network training algorithm, called SKYNET. This efficient and robust machine learning tool is able to train large and deep feed-forward neural networks, including autoencoders, for use in a wide range of supervised and unsupervised learning applications, such as regression, classification, density estimation, clustering and dimensionality reduction. SKYNET uses a `pre-training' method to obtain a set of network parameters that has empirically been shown to be close to a good solution, followed by further optimization using a regularized variant of Newton's method, where the level of regularization is determined and adjusted automatically; the latter uses second-order derivative information to improve convergence, but without the need to evaluate or store the full Hessian matrix, by using a fast approximate method to calculate Hessian-vector products. This combination of methods allows for the training of complicated networks that are difficult to optimize using standard backpropagation techniques. SKYNET employs convergence criteria that naturally prevent overfitting, and also includes a fast algorithm for estimating the accuracy of network outputs. The utility and flexibility of SKYNET are demonstrated by application to a number of toy problems, and to astronomical problems focusing on the recovery of structure from blurred and noisy images, the identification of gamma-ray bursters, and the compression and denoising of galaxy images. The SKYNET software, which is implemented in standard ANSI C and fully parallelized using MPI, is available at http://www.mrao.cam.ac.uk/software/skynet/.

  11. Nuclear weapon race does not stop; Le nucleaire ne desarme pas

    Energy Technology Data Exchange (ETDEWEB)

    Vahe Ter, Minassian

    2005-04-01

    60 years after Hiroshima, the race for nuclear weaponry keeps on. The comprehensive test ban treaty (CTBT), signed in 1996 by the 5 official nuclear-weapon-owning states (Usa, Russia, China, U.K. and France), has not yet been implemented because its implementation requires the ratification of 44 states that harbour on their territories industrial or research nuclear reactors. Till now only 33 such states have ratified CTBT. CTBT aims at prohibiting any nuclear test whatever the amount of energy released in it. Countries like Usa, North-Korea, Russia, soon Iran... are suspected to develop new types of nuclear warfare. For 2005 the American Congress have decided to freeze the funding of programmes dedicated to the development of 'mini-nukes' like the bunker-burster. The international network of monitoring stations will soon cover all the world and will be able to detect and locate, in an almost automated way, any test involving an energy greater than 1 kiloton. 321 stations have been settled and their efficient detection systems are based on seismic or infra-sound or radioactivity or hydro-acoustic analysis. (A.C.)

  12. ANTARES: An Undersea Neutrino telescope

    CERN Multimedia

    2002-01-01

    The ANTARES (Astronomy with a Neutrino Telescope and ${Abyss}$ environmental RESearch) deep-sea neutrino telescope is designed to search for neutrinos of astrophysical origin. Neutrinos are unique probes of the high energy universe; being neutral they are not deflected by magnetic fields and interacting weakly they can readily escape from the densest regions of the universe. Potential sources of neutrino are galactic (e.g supernova remnants, micro-quasars) and extra-galactic (e.g active galactic nuclei, gamma-ray bursters). Annihilation of dark matter particles in the Sun or Galactic Centre is another well motivated potential source of extra terrestrial neutrinos. The ANTARES detector is located 40 km off the coast of Toulon (France) at a depth of 2475m in the Mediterranean Sea. Being located in the Northern hemisphere it studies the Southern sky and in particular has the Galactic Centre in its field of view. Since 2006, the detector has operated continuously in a partial configuration. The detector was compl...

  13. Systematic Uncertainties in the Spectroscopic Measurements of Neutron-Star Masses and Radii from Thermonuclear X-ray Bursts. III. Absolute Flux Calibration

    CERN Document Server

    Guver, Tolga; Marshall, Herman; Psaltis, Dimitrios; Guainazzi, Matteo; Diaz-Trigo, Maria

    2015-01-01

    Many techniques for measuring neutron star radii rely on absolute flux measurements in the X-rays. As a result, one of the fundamental uncertainties in these spectroscopic measurements arises from the absolute flux calibrations of the detectors being used. Using the stable X-ray burster, GS 1826-238, and its simultaneous observations by Chandra HETG/ACIS-S and RXTE/PCA as well as by XMM-Newton EPIC-pn and RXTE/PCA, we quantify the degree of uncertainty in the flux calibration by assessing the differences between the measured fluxes during bursts. We find that the RXTE/PCA and the Chandra gratings measurements agree with each other within their formal uncertainties, increasing our confidence in these flux measurements. In contrast, XMM-Newton EPIC-pn measures 14.0$\\pm$0.3% less flux than the RXTE/PCA. This is consistent with the previously reported discrepancy with the flux measurements of EPIC-pn, compared to EPIC-MOS1, MOS2 and ACIS-S detectors. We also address the calibration uncertainty in the RXTE/PCA int...

  14. NuSTAR observation of a Type I X-ray burst from GRS 1741.9-2853

    CERN Document Server

    Barrière, Nicolas M; Tomsick, John A; Bachetti, Matteo; Boggs, Steven E; Chakrabarty, Deepto; Christensen, Finn E; Craig, William W; Hailey, Charles J; Harrison, Fiona A; Hong, Jaesub; Mori, Kaya; Stern, Daniel; Zhang, William W

    2014-01-01

    We report on two NuSTAR observations of GRS 1741.9-2853, a faint neutron star low mass X-ray binary burster located 10' away from the Galactic center. NuSTAR detected the source serendipitously as it was emerging from quiescence: its luminosity was $6\\times 10^{34}$ erg~s$^{-1}$ on 2013 July 31, and $5\\times 10^{35}$ erg~s$^{-1}$ in a second observation on 2013 August 3. A bright, 800-s long, H-triggered mixed H/He thermonuclear Type I burst with mild photospheric radius expansion (PRE) was present during the second observation. Assuming that the luminosity during the PRE was at the Eddington level, a H mass fraction $X=0.7$ in the atmosphere, and a neutron star mass $M=1.4 M_{\\odot}$, we determine a new lower limit on the distance for this source of $6.3 \\pm 0.5$ kpc. Combining with previous upper limits, this places GRS 1741.9-2853 at a distance of 7 kpc. Energy independent (achromatic) variability is observed during the cooling of the neutron star, which could result from the disturbance of the inner accre...

  15. Simultaneous optical and X-ray bursts from 4U/MXB 1636-53

    Science.gov (United States)

    Pedersen, H.; Lub, J.; Inoue, H.; Koyama, K.; Makishima, K.; Matsuoka, M.; Mitsuda, K.; Murakami, T.; Oda, M.; Ogawara, Y.

    1982-01-01

    Methods of obtaining information about the geometry of X-ray burster systems from simultaneous optical and X-ray observations are discussed, and such simultaneous observations of 4U/MXB 1636-53 are reported. The physical idea of an optical burst being due to reprocessing of an X-ray burst in material in the vicinity of the compact object is discussed. The resulting modification of the X-ray burst signal is described in terms of an optical response function. Delay and smearing due to radiative processes are discussed along with those due to the geometry. For 4U/MXB 1636-53, the estimated delay is 2.5 seconds, the smearing is less than four seconds, and the maximum temperature of the reprocessing region is about 75,000 K. The projected area of the reprocessing region is about 6 x 10 to the 21st square cm. The neutron star is about 1.4 solar masses, the radius of the accretion disk is greater than 1.5 lt-sec, and the mass of the Roche lobe filling companion star is less than 2.0 solar masses, corresponding to a binary period between about one and ten hours.

  16. INTEGRAL sees transient activity in the Galactic Bulge: XTE J1751-305 and GRS 1741.9-2853 in outburst

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Kuulkers, E.; Beckmann, V.;

    2009-01-01

    Crab in above-mentioned energy ranges. IBIS/ISGRI did also detect GRS 1741.9-2853 with an average intensity of about 10 mCrab and significance of 6.1 sigma in the 18-40 keV range. The accreting millisecond X-ray pulsar XTE J1751-305 (e.g. Markwardt et al. ApJ 575, L21, 2002) is detected with JEM-X at 15 +/- 6 m......, the closeby and recently discovered accreting millisecond X-ray pulsar IGR J17511-3057 (e.g. ATels #2196-2199) has dimmed to below the INTEGRAL detection levels, whereas it was still detected 6 days earlier at about 12 mCrab averaged over the above-mentioned energy bands. The 3-sigma upper limits are now...... about 5 mCrab and about 2 mCrab between 3-10 keV and 10-25 keV, respectively. We further notice that none of the X-ray bursters in the close source pair SLX 1744-299/300 is significantly detected in JEM-X with 3-sigma upper limits of about 6 mCrab (3-10 keV) and about 3 mCrab (10-25 keV). This seems...

  17. INTEGRAL confirms the detection of renewed activity from the NS transient H 1658-298

    DEFF Research Database (Denmark)

    Sanchez-Fernandez, C.; Eckert, D.; Bozzo, E.;

    2015-01-01

    INTEGRAL observed the Galactic Center Region between (UT) 2015-08-22 05:26 and 18:44. Enhanced X-ray emission was detected by the Joint European Monitor for X-rays (JEM-X) in the 3-10 keV band, (15 mCrab; 9-sigma significance) at the following position: (R.A., Dec) = (255.5284, -29.94175) = (17 02...... (see ATel #7943). The source spectrum extracted from the JEM-X data (effective exposure time 10.7 ksec) can be fit by a power-law model with photon index 2.9+/-0.5. The flux estimated from the spectral fit is 2.8E-10 erg/cm^2/s (3-10 keV). H 1658-298 was marginally detected in hard X-rays (~6.8 m......Crab, 4.5-sigma significance in the 20-40 keV energy band) by IBIS, the Imager Onboard the INTEGRAL Satellite. H 1658-298 is a known X-ray burster. Therefore we have searched for Type-I burst activity in the JEM-X data during these observations, but no indications of burst activity have been found. We...

  18. Gamma-Ray Bursts: Should cosmologists care?

    Science.gov (United States)

    Laros, J. G.

    1996-03-01

    Gamma-Ray Burst (GRB) locations are distributed isotropically on the sky, but the intensity distribution of the bursts seems clearly incompatible with spatial homogeneity. Of the scenarios that attempt to provide an explanation, there are two that enjoy current popularity: (1) GRBs are produced by high-velocity neutron stars that have formed an extended (˜100 kpc) spherical halo or “corona” around our galaxy. (2) The bursters are at cosmological distances, with redshifts near unity for the weaker events. The major evidence used to argue for or against each of these scenarios remains inconclusive. Assuming, not unreasonably, that the cosmological scenario is correct, one can discuss the advantages and disadvantages of studying GRBs as opposed to other objects at moderate redshift. We find that the advantages of GRBs-high intensity, penetrating radiation, rapid variability, and no expected source evolution-are offset by observational difficulties pertaining to the extraction of cosmological information from GRB data. If the cosmological scenario proves to be correct and if the observational difficulties are overcome, then cosmologists certainly should care.

  19. X-ray burst induced spectral variability in 4U 1728-34

    CERN Document Server

    Kajava, J J E; Kuulkers, E; Poutanen, J

    2016-01-01

    Aims. INTEGRAL has been monitoring the Galactic center region for more than a decade. Over this time INTEGRAL has detected hundreds of type-I X-ray bursts from the neutron star low-mass X-ray binary 4U 1728-34, a.k.a. "the slow burster". Our aim is to study the connection between the persistent X-ray spectra and the X-ray burst spectra in a broad spectral range. Methods. We performed spectral modeling of the persistent emission and the X-ray burst emission of 4U 1728-34 using data from the INTEGRAL JEM-X and IBIS/ISGRI instruments. Results. We constructed a hardness intensity diagram to track spectral state variations. In the soft state the energy spectra are characterized by two thermal components - likely from the accretion disc and the boundary/spreading layer - together with a weak hard X-ray tail that we detect in 4U 1728-34 for the first time in the 40 to 80 keV range. In the hard state the source is detected up to 200 keV and the spectrum can be described by a thermal Comptonization model plus an addit...

  20. Luminosities of Disk--accreting Non--magnetic Neutron Stars

    CERN Document Server

    Thampan, A V

    2002-01-01

    Disk accretion onto a neutron star possessing a weak surface magnetic field ($B \\le 10^8$ G) provides interesting X-ray emission scenarios, and is relevant for understanding X-ray bursters and low-mass X-ray binaries (LMXBs). The standard (Newtonian) theory of disk-accretion predicts that the matter spiralling in from infinity loses one-half of its total gravitational energy in the extended disk, and the remainder in a narrow boundary layer girdling the neutron star. The ratio of the boundary layer luminosity to that from the disk ($E_{\\rm BL}/E_{\\rm D}$) is, therefore, unity. On incorporation of general relativity without rotation (Schwarzschild solution), $E_{\\rm BL}/E_{\\rm D}$ is seen to be as high as 6. We construct rotating sequences of neutron stars for three representative equations of state. We show here that for a neutron star rotating at a limit where centrifugal force balances the inward gravitational force, $E_{\\rm BL}/E_{\\rm D}\\sim 0$.

  1. 22nd SLAC Summer Institute on Particle Physics: Particle physics, astrophysics and cosmology

    Science.gov (United States)

    Chan, J.; Deporcel, L.

    The seven-day school portion of the Institute revolved around the question of dark matter: where is it and what is it? Reviews were given of microlensing searches for baryonic dark matter, of dark matter candidates in the form of neutrinos and exotic particles, and of low-noise detection techniques used to search for the latter. The history of the universe, from the Big Bang to the role of dark matter in the formation of large-scale structure, was also covered. Other lecture series described the astrophysics that might be done with x-ray timing experiments and through the detection of gravitational radiation. As in past years, the lectures each morning were followed by stimulating afternoon discussion sessions, in which students could pursue with the lecturers the topics that most interested them. The Institute concluded with a three-day topical conference covering recent developments in theory and experiment. Highlights from the astrophysical and cosmological arenas included observations of anisotropy in the cosmic microwave background, and of the mysterious gamma-ray bursters. From terrestrial accelerators came tantalizing hints of the top quark and marked improvements in precision electroweak measurements, among many other results. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  2. Identification of the optical and quiescent counterparts to the bright X-ray transient in NGC 6440

    CERN Document Server

    in 't Zand, J J M; Pooley, D; Verbunt, F; Wijnands, R; Lewin, W H G

    2001-01-01

    After 3 years of quiescence, the globular cluster NGC 6440 exhibited a bright transient X-ray source turning on in August 2001, as noted with the RXTE All-Sky Monitor. We carried out a short target of opportunity observation with the Chandra X-ray Observatory and are able to associate the transient with the brightest of 24 X-ray sources detected during quiescence in July 2000 with Chandra. Furthermore, we securely identify the optical counterpart and determine that the 1998 X-ray outburst in NGC 6440 was from the same object. This is the first time that an optical counterpart to a transient in a globular cluster is securely identified. Since the transient is a type I X-ray burster, it is established that the compact accretor is a neutron star. Thus, this transient provides an ideal case to study the quiescent emission in the optical and X-ray of a transiently accreting neutron star while knowing the distance and reddening accurately. One model that fits the quiescent spectrum is an absorbed power law plus neu...

  3. Mixed-mode oscillations in a multiple time scale phantom bursting system

    CERN Document Server

    Krupa, Maciej; Desroches, Mathieu; Clément, Frédérique

    2012-01-01

    In this work we study mixed mode oscillations in a model of secretion of GnRH (Gonadotropin Releasing Hormone). The model is a phantom burster consisting of two feedforward coupled FitzHugh-Nagumo systems, with three time scales. The forcing system (Regulator) evolves on the slowest scale and acts by moving the slow nullcline of the forced system (Secretor). There are three modes of dynamics: pulsatility (transient relaxation oscillation), surge (quasi steady state) and small oscillations related to the passage of the slow nullcline through a fold point of the fast nullcline. We derive a variety of reductions, taking advantage of the mentioned features of the system. We obtain two results; one on the local dynamics near the fold in the parameter regime corresponding to the presence of small oscillations and the other on the global dynamics, more specifically on the existence of an attracting limit cycle. Our local result is a rigorous characterization of small canards and sectors of rotation in the case of fo...

  4. Models of Type I X-ray Bursts from GS 1826-24: A Probe of rp-Process Hydrogen Burning

    CERN Document Server

    Heger, Alexander; Galloway, Duncan K; Woosley, Stanford E

    2007-01-01

    The X-ray burster GS 1826-24 shows extremely regular Type I X-ray bursts whose energetics and recurrence times agree well with thermonuclear ignition models. We present calculations of sequences of burst lightcurves using multizone models which follow the rp-process nucleosynthesis with an extensive nuclear reaction network. The theoretical and observed burst lightcurves show remarkable agreement. The models naturally explain the slow ~5s rise and long ~100s tails of these bursts, as well as their dependence on mass accretion rate. This comparison provides further evidence for solar metallicity in the accreted material in this source, and constrains the distance to the source. The main difference is that the observed lightcurves do not show the distinct two-stage rise of the models. This may reflect the time for burning to spread over the stellar surface, or may indicate that our treatment of heat transport or nuclear physics needs to be revised. The trends in burst properties with accretion rate are well-rep...

  5. Thermal, spectral, and surface properties of LED light-polymerized bulk fill resin composites.

    Science.gov (United States)

    Pişkin, Mehmet Burçin; Atalı, Pınar Yılmaz; Figen, Aysel Kantürk

    2015-02-01

    The aim of this study was to evaluate the thermal, spectral, and surface properties of four different bulk fill materials – SureFil SDR (SDR, Dentsplay DETREY), QuixFil (QF, Dentsplay DETREY), X-tra base (XB, Voco) X-tra fil (XF, Voco) – polymerized by light-emitting diode (LED). Resin matrix, filler type, size and amount, and photoinitiator types influence the degree of conversion. LED-cured bulk fill composites achieved sufficient polymerization. Scanning electron microscope (SEM) analysis revealed different patterns of surface roughness, depending on the composite material. Bulk fill materials showed surface characteristics similar to those of nanohybrid composites. Based on the thermal analysis results, glass transition (T(g)) and initial degradation (T(i)) temperatures changed depending on the bulk fill resin composites.

  6. Re4As6S3, a thio-spinel-related cluster system

    DEFF Research Database (Denmark)

    Besnard, Celine; Svensson, Christer; Ståhl, Kenny

    2003-01-01

    We have synthesized a new compound with formula Re4As6S3 and characterized its crystal structure by Rietveld powder diffraction methods. Re4As6S3 crystallizes in an face-centered cubic unit cell, space group F (4) over bar 3m (no. 216), with lattice constant a = 9.8608(1) Angstrom and Z = 4....... The rhenium atoms form tetrahedral clusters linked via tetrahedral arsenic clusters to produce an NaCl-type arrangement. The oxidation state of rhenium is IV and the number of electrons shared by the rhenium atoms in the cluster is 12. The structure is based on an ordered defect thio-spinel A((1-x))B(2)X(4...

  7. CEPF Western Ghats Special Series: Length-weight and length-length relationship of three species of snakehead fish, Channa diplogramma, C. marulius and C. striata from the riverine reaches of Lake Vembanad, Kerala, India.

    Directory of Open Access Journals (Sweden)

    A. Ali

    2013-09-01

    Full Text Available The length-weight relationship (LWR and length-length relationships (LLR of three snakehead fishes, Channa diplogramma, C. marulius and C. striata, exploited by small-scale fishers in the riverine reaches of Lake Vembanad, Kerala were studied using the allometric growth equation Y = aXb. Our analysis shows that the LWR of C. diplogramma and C. marulius is nonisometric with exponents much smaller than the cubic value (b = 3, while that of C. striata is isometric. Channa marulius showed a definite change in LWR with size, with smaller fish growing with positive allometric exponents (b greater than 3 and larger individuals having negative allometric relationship (b less than 3, indicating a possible age-related change in growth pattern. In the case of LLR, all three snakehead species showed non-isometric growth patterns. The caudal fin did not grow substantially with increasing fish length.

  8. 以仿正规算子为参数的初等算子的性质%Properties of an Elementary Operator with Paranormal Operators as Parameters

    Institute of Scientific and Technical Information of China (English)

    高福根; 李晓春

    2015-01-01

    若对(V)z∈(H)||Tx||2≤||T2x||||x||,则称T是仿正规算子.dAB表示δAB或△AB,其中δAB和△AB分别表示Banach空间B((H))上的广义导算子和初等算子,其定义为δABX=AX-XB,△ABX=AXB-X,VX∈B((H)).若A和B*是仿正规算子,则可证dAB是polaroid算子,(V)f∈H(σ(dAB)),f(dAB)满足广义Weyl定理,f(d*AB)满足广义a-Weyl定理,其中H(σ(dAB))表示在σ(dAB)的某邻域上解析的函数全体.

  9. Design Criteria and Machine Integration of the Ignitor Experiment

    Science.gov (United States)

    Bianchi, A.; Coppi, B.

    2010-11-01

    High field, high density compact experiments are the only ones capable of producing, on the basis of available technology and knowledge of plasma physics, plasmas that can reach ignition conditions. The Ignitor machine (R01.32 m, a xb0.47x0.83 m^2, BTmachine is based on an optimized combination of ``bucking'' and ``wedging''. All components, with the exception of the vacuum vessel, are cooled before each plasma pulse by means of He gas, to an optimal temperature of 30 K, at which the ratio of the electrical resistivity to the specific heat of copper is minimum. The 3D and 2D design and integration of all the core machine components, including electro-fluidic and fluidic lines, has been produced using the Dassault CATIA-V software. A complete structural analysis has verified that the machine can withstand the forces produced for all the main operational scenarios.

  10. 焙烧硼钠钙石在高固液化比氯化铵溶液中的熔解动力学%Dissolution Kinetics of Calcined Ulexite in Ammonium Chloride Solutions at High Solid-to-Liquid Ratios

    Institute of Scientific and Technical Information of China (English)

    G(U)R; Aycan

    2006-01-01

    The dissolution kinetics of calcined ulexite in ammonium chloride solutions at high solid-to-liquid ratios were investigated. In the experiments, calcination temperature, solution concentration, reaction temperature, and prehydration were chosen as parameters. It was observed that the dissolution rate increased with increasing calcination temperature, solution concentration, and reaction temperature, whereas it was not affected by pre-hydration. Employing graphical and statistic methods, the dissolution rate, based on homogeneous reaction model,can be given as: (1-X(B2O3))-1-1=k(c(NH4Cl))1.982t. The activation energy for the dissolution of the ulexite sample calcined at 160 ℃ was found to be

  11. Incorporação de dióxido de titânio em zeólitas para emprego em fotocatálise heterogênea Titanium oxide incorporation on zeolites for heterogeneous photocatalisis

    Directory of Open Access Journals (Sweden)

    Jean C. Merg

    2010-01-01

    Full Text Available This work proposes the study of heterogeneous photocatalysis using TiO2 impregnated in zeolites beta, ZSM-5, mordenite, NaXb, NaXp and NaY for the decomposition of methylene blue. The catalysts were characterized by XRD, IR, textural analyses by N2 adsorption, SEM, DRS and the reaction of decomposition was monitored by UV visible. The results indicated that didn't have structural changes in the catalysts after Ti impregnations, only in the case of NaY and NaX zeolites. The better photocatalyst to metylene blue decomposition was beta/Ti zeolite due had one structure more accessible (with bigger porous helping in TiO2 dispersion and catalytic active.

  12. Investigation of Proton-Proton Short-Range Correlations via the 12C(e,e'pp) Reaction

    Energy Technology Data Exchange (ETDEWEB)

    J. Arrington; H. Benaoum; F. Benmokhtar; P. Bertin; W. Bertozzi; W. Boeglin; J. P. Chen; Seonho Choi; E. Chudakov; E. Cisbani; B. Craver; C. W. de Jager; R. Feuerbach; S. Frullani; F. Garibaldi; O. Gayou; S. Gilad; R. Gilman; O. Glamazdin; J. Gomez; O. Hansen; D. W. Higinbotham; T. Holmstrom; H. Ibrahim; R. Igarashi; E. Jans; X. Jiang; Y. Jiang; L. Kaufman; A. Kelleher; A. Kolarkar; E. Kuchina; G. Kumbartzki; J. J. LeRose; R. Lindgren; N. Liyanage; D. J. Margaziotis; P. Markowitz; S. Marrone; M. Mazouz; R. Michaels; B. Moffit; S. Nanda; C. F. Perdrisat; E. Piasetzky; M. Potokar; V. Punjabi; Y. Qiang; J. Reinhold; B. Reitz; G. Ron; G. Rosner; A. Saha; B. Sawatzky; A. Shahinyan; S. Sirca; K. Slifer; P. Solvignon; V. Sulkosky; N. Thompson; P. E. Ulmer; G. M. Urciuoli; E. Voutier; K. Wang; J. W. Watson

    2007-08-01

    We investigated simultaneously the 12C(e,e'p) and 12C(e,e'pp) reactions at Q2 = 2 [GeV/c]2, x_B = 1.2, and in an (e,e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics, with a missing-momentum greater than the Fermi momentum of nucleons in a nucleus and far from the delta excitation, short-range nucleon-nucleon correlations are predicted to dominate the reaction. For(9.5 +/- 2)% of the 12C(e,e'p) events, a recoiling partner proton was observed back-to-back to the 12C(e,e'p) missing momentum vector, an experimental signature of correlations.

  13. Analysis of the strong decay X(5568) → B{sub s}{sup 0}π{sup +} with QCD sum rules

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhi-Gang [North China Electric Power University, Department of Physics, Baoding (China)

    2016-05-15

    In this article, we take the X(5568) to be the scalar diquark-antidiquark type tetraquark state, study the hadronic coupling constant g{sub XB{sub sπ}} with the three-point QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension-6 and including both the connected and the disconnected Feynman diagrams; then we calculate the partial decay width of the strong decay X(5568) → B{sub s}{sup 0}π{sup +} and obtain the value Γ{sub X} = (20.5 ± 8.1) MeV, which is consistent with the experimental data Γ{sub X} = (21.9 ± 6.4{sup +5.0}{sub -2.5}) MeV from the D0 collaboration. (orig.)

  14. Exclusive $\\rho^0$ meson electroproduction from hydrogen at CLAS

    CERN Document Server

    Hadjidakis, C; Garçon, M; Laget, J M; Smith, E S; Vanderhaeghen, M; Adams, G; Ambrozewicz, P; Anciant, E; Anghinolfi, M; Asavapibhop, B; Asryan, G; Audit, G; Auger, T; Avakian, H; Bagdasaryan, H; Ball, J P; Barrow, S; Battaglieri, M; Beard, K; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Bianchi, N; Biselli, A S; Boiarinov, S; Bonner, B E; Bouchigny, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Burkert, V D; Butuceanu, C; Calarco, J R; Carman, D S; Carnahan, B; Cetina, C; Chen, S; Cole, P L; Coleman, A; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J P; De Sanctis, E; De Vita, R; Degtyarenko, P V; Dennis, L; Dharmawardane, K V; Dhuga, K S; Didelez, J P; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Empl, A; Eugenio, P; Farhi, L; Fatemi, R; Feuerbach, R J; Forest, T A; Frolov, V; Funsten, H; Gaff, S J; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girard, P; Gordon, C I O; Gothe, R W; Griffioen, K A; Guillo, M; Güler, M; Guo, L; Gyurjyan, V; Hakobyan, R S; Hardie, J; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, H; Holtrop, M; Hourany, E; Hu, J; Hyde-Wright, C E; Ilieva, Y; Ireland, D; Ito, M M; Jenkins, D; Joo, K; Jüngst, H G; Kelley, J H; Kellie, J; Khandaker, M; Kim, K Y; Kim, K; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Klusman, M; Kossov, M; Kramer, L H; Kuhn, S E; Kühn, J; Lachniet, J; Langheinrich, J; Lawrence, D; Lee, T; Ji Li; Livingstone, K; Lukashin, K; Manak, J J; Marchand, C; Maximon, L C; McAleer, S; McNabb, J W C; Mecking, B A; Melone, J J; Mestayer, M D; Meyer, C A; Mikhailov, K; Minehart, R C; Mirazita, M; Miskimen, R; Morand, L; Morrow, S A; Muccifora, V; Müller, J; Mutchler, G S; Napolitano, J; Nasseripour, R; Nelson, S O; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niyazov, R A; Nozar, M; O'Rielly, G V; Osipenko, M; Park, K; Pasyuk, E A; Peterson, G; Philips, S A; Pivnyuk, N; Pocanic, D; Pogorelko, O I; Polli, E; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rossi, P; Rosner, G; Rowntree, D; Rubin, P D; Sabatie, F; Sabourov, K; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Shafi, A; Sharabyan, Yu G; Shaw, J; Simionatto, S; Skabelin, A V; Smith, L C; Sober, D I; Spraker, M; Stavinsky, A V; Stepanyan, S; Stokes, B E; Stoler, P; Strauch, S; Taiuti, M; Taylor, S; Tedeschi, D J; Thoma, U; Thompson, R; Tkabladze, A; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Wang, K; Weinstein, L B; Weller, H; Weygand, D P; Whisnant, C S; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Zana, L

    2004-01-01

    The longitudinal and transverse components of the cross section for the $e p\\to e^\\prime p \\rho^0$ reaction were measured in Hall B at Jefferson Laboratory using the CLAS detector. The data were taken with a 4.247 GeV electron beam and were analyzed in a range of $x_B$ from 0.2 to 0.6 and of $Q^2$ from 1.5 to 3.0 GeV$^2$. The data are compared to a Regge model based on effective hadronic degrees of freedom and to a calculation based on Generalized Parton Distributions. It is found that the transverse part of the cross section is well described by the former approach while the longitudinal part can be reproduced by the latter.

  15. Identification and inspection of the vacancy site in Li doped BPO 4 ceramic electrolyte by NMR

    Science.gov (United States)

    Dodd, A. J.; van Eck, E. R. H.

    2002-10-01

    A study of the properties of the high temperature ceramic electrolyte Li xB 1- x/3 PO 4 (lithium boron phosphate) is reported. XRD and NMR are used to investigate changes of the material as a function of heat treatment. It was found that after synthesis at 450 °C the material contains a phase of Li 4P 2O 7 in addition to the BPO 4 phase. This second phase is removed by heat treatment at temperatures higher than 600 °C. Boron vacancies are present, REDOR and CPMAS techniques are used to investigate this defect site and show that for the heat treated material Li ions are present at the vacancy site.

  16. Deeply Virtual Compton Scattering Beam-Spin Asymmetries

    CERN Document Server

    Girod, F X; Ball, J; Bedlinskiy, I; Burkert, V D; De Masi, R; Elouadrhiri, L; Garçon, M; Guidal, M; Jo, H S; Joo, K; Kubarovski, V; Kuleshov, S V; MacCormick, M; Niccolai, S; Pogorelko, O; Sabati, F; Stepanyan, S; Stoler, P; Ungaro, M; Zhao, B; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Batourine, V; Battaglieri, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Blaszczyk, L; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Chen, S; Cheng, L; Cole, P L; Collins, P; Coltharp, P; Crabb, D; Credé, V; Dashyan, N; De Sanctis, E; De Vita, R; Degtyarenko, P V; Deur, A; Dharmawardane, K V; Dickson, R; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Eugenio, P; Fedotov, G; Feldman, G; Funsten, H; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Goetz, J T; Gonenc, A; Gothe, R W; Griffioen, K A; Guler, N; Guo, L; Gyurjyan, V; Hafidi, K; Hakobyan, H; Hanretty, C; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Johnstone, J R; Jüngst, H G; Kalantarians, N; Kellie, J D; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Kossov, M; Krahn, Z; Kramer, L H; Kühn, J; Kuhn, S E; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Lee, T; Livingston, K; Lu, H Y; Markov, N; Mattione, P; Mazouz, M; McKinnon, B; Mecking, B A; Mestayer, M D; Meyer, C A; Mibe, T; Michel, B; Mikhailov, K; Mirazita, M; Miskimen, R; Mokeev, V; Moriya, K; Morrow, S A; Moteabbed, M; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nasseripour, R; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Anefalos Pereira, S; Pierce, J; Pivnyuk, N; Pocanic, D; Pozdniakov, S; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Raue, B A; Ricco, G; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Salamanca, J; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabyan, Yu G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Stavinsky, A; Stepanyan, S S; Stokes, B E; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Tkabladze, A; Tkachenko, S; Tur, C; Vineyard, M F; Vlassov, A V; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Zana, L; Zhang, J; Zhao, Z W

    2007-01-01

    The beam spin asymmetries in the hard exclusive electroproduction of photons on the proton (ep -> epg) were measured over a wide kinematic range and with high statistical accuracy. These asymmetries result from the interference of the Bethe-Heitler process and of deeply virtual Compton scattering. Over the whole kinematic range (x_B from 0.11 to 0.58, Q^2 from 1 to 4.8 GeV^2, -t from 0.09 to 1.8 GeV^2), the azimuthal dependence of the asymmetries is compatible with expectations from leading-twist dominance, A = a*sin(phi)/[1+c*cos(phi)]. This extensive set of data can thus be used to constrain significantly the generalized parton distributions of the nucleon in the valence quark sector.

  17. Beam spin asymmetry in deep and exclusive pi0 electroproduction

    CERN Document Server

    De Masi, R; Zhao, B; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J; Ball, J P; Baltzell, N A; Batourine, V; Battaglieri, M; Bedlinskiy, I; Bellis, M; Benmouna, N; Berman, B L; Bertin, P; Biselli, A S; Blaszczyk, L; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Burkert, V D; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Chen, S; Cheng, L; Cole, P L; Collins, P; Coltharp, P; Crabb, D; Credé, V; Dashyan, N; De Sanctis, E; De Vita, R; Degtyarenko, P V; Deur, A; Dharmawardane, K V; Dickson, R; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Feldman, G; Fradi, A; Funsten, H; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gonenc, A; Gothe, R W; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Gyurjyan, V; Hafidi, K; Hakobyan, H; Hanretty, C; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Jüngst, H G; Kalantarians, N; Kellie, J D; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Kossov, M; Krahn, Z; Kramer, L H; Kubarovski, V; Kühn, J; Kuhn, S E; Kuleshov, S V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Lee, T; Livingston, K; Lu, H Y; MacCormick, M; Markov, N; Mattione, P; Mazouz, M; McKinnon, B; Mecking, B A; Mestayer, M D; Meyer, C A; Mibe, T; Michel, B; Mikhailov, K; Mirazita, M; Miskimen, R; Mokeev, V; Moreno, B; Moriya, K; Morrow, S A; Moteabbed, M; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Anefalos Pereira, S; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Raue, B A; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Sabati, F; Salamanca, J; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, e V S; Sharabyan, Yu G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Stavinsky, A; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Tkabladze, A; Tkachenko, S; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Zana, L; Zhang, J; Zhao, Z W

    2007-01-01

    The beam spin asymmetry (BSA) in the exclusive reaction ep->ep pi0 was measured with the CEBAF 5.77 GeV polarized electron beam and Large Acceptance Spectrometer(CLAS). The xB, Q2, t and phi dependences of the pi0 BSA are presented in the deep inelastic regime. The asymmetries are fitted with a sin(phi) function and their amplitudes are extracted. Overall, they are of the order of 0.04 - 0.11 and roughly independent of t. This is the signature of a non-zero longitudinal-transverse interference. The implications concerning the applicability of a formalism based on generalized parton distributions, as well as the extension of a Regge formalism at high photon virtualities, are discussed.

  18. Xenobiology meets enzymology: Exploring the potential of unnatural building blocks in biocatalysis.

    Science.gov (United States)

    Budisa, Nediljko; Völler, Jan-Stefan; Koksch, Beate; Acevedo-Rocha, Carlos G; Kubyshkin, Vladimir; Agostini, Federica

    2017-01-13

    Xenobiology (XB) aims to design biological systems endowed with unusual biochemistries, while enzymology concerns the study of enzymes, the workhorses of biocatalysis. Biocatalysis employs enzymes and organisms to perform useful biotransformations in synthetic chemistry and biotechnology. During the past years, the effects of incorporating noncanonical amino acids (ncAAs) into enzymes with potential applications in biocatalysis have been increasingly investigated. Here we provide an overview of the effects of new chemical functionalities that have been introduced into proteins to improve various facets of enzymatic catalysis. We also discuss future research avenues that will complement unnatural mutagenesis with the standard protein-engineering toolbox for producing novel and versatile biocatalysts with applications in synthetic organic chemistry and biotechnology.

  19. Power Cocentralizing Generalized Derivations on Prime Rings

    Indian Academy of Sciences (India)

    Vincenzo De Filippis

    2010-06-01

    Let be a prime ring, the Utumi quotient ring of $R,C=Z(U)$ the extended centroid of , a non-central Lie ideal of , and non-zero generalized derivations of . Suppose that there exists an integer $n≥ 1$ such that $(H(u)u-uG(u))^n=0$, for all $u\\in L$, then one of the following holds: (1) there exists $c\\in U$ such that $H(x)=xc,G(x)=cx;(2)R$ satisfies the standard identity $s_4$ and char ()=2; (3) satisfies $s4$ and there exist $a, b, c\\in U$, such that $H(x)=ax+xc,G(x)=cx+xb$ and $(a-b)^n=0$.

  20. Exact distribution of MLE of covariance matrix in a GMANOVA-MANOVA model

    Institute of Scientific and Technical Information of China (English)

    BAI; Peng

    2005-01-01

    For a GMANOVA-MANOVA model with normal error: Y = XB1Z1T + B2Z2T +E, E ~ Nq×n(0, In(×) ∑), the present paper is devoted to the study of distribution of MLE,Σ, of covariance matrix ∑. The main results obtained are stated as follows: (1) When rk(Z) -rk(Z2) ≥ q-rk(X), the exact distribution of (Σ) is derived, where Z = (Z1, Z2), rk(A)denotes the rank of matrix A. (2) The exact distribution of |(Σ)| is gained. (3) It is proved that ntr{[∑-1 - ∑-1XM(MTXT∑-1XM)-1MTXT∑-1]Σ} has x2(q-rk(X))(n-rk(Z2)) distribution, where M is the matrix whose columns are the standardized orthogonal eigenvectors corresponding to the nonzero eigenvalues of XT∑-1X.