Optical investigation of vacuum evaporated Se80-xTe20Sbx (x = 0, 6, 12) amorphous thin films

NASA Astrophysics Data System (ADS)

Deepika; Singh, Hukum

2017-09-01

Amorphous thin films of Se80-xTe20Sbx (x = 0, 6, 12) chalcogenide glasses has been deposited onto pre-cleaned glass substrate using thermal evaporation technique under a vacuum of 10-5 Torr. The absorption and transmission spectra of these thin films have been recorded using UV spectrophotometer in the spectral range 400-2500 nm at room temperature. Swanepoel envelope method has been employed to obtain film thickness and optical constants such as refractive index, extinction coefficient and dielectric constant. The optical band gap of the samples has been calculated using Tauc relation. The study reveals that optical band gap decreases on increase in Sb content. This is due to decrease in average single bond energy calculated using chemical bond approach. The values of urbach energy has also been computed to support the above observation. Variation of refractive index has also been studies in terms of wavelength and energy using WDD model and values of single oscillator energy and dispersion energy has been obtained.

Marginal Gap Formation in Approximal "Bulk Fill" Resin Composite Restorations After Artificial Ageing.

PubMed

Peutzfeldt, A; Mühlebach, S; Lussi, A; Flury, S

The aim of this in vitro study was to investigate the marginal gap formation of a packable "regular" resin composite (Filtek Supreme XTE [3M ESPE]) and two flowable "bulk fill" resin composites (Filtek Bulk Fill [3M ESPE] and SDR [DENTSPLY DeTrey]) along the approximal margins of Class II restorations. In each of 39 extracted human molars (n=13 per resin composite), mesial and distal Class II cavities were prepared, placing the gingival margins below the cemento-enamel junction. The cavities were restored with the adhesive system OptiBond FL (Kerr) and one of the three resin composites. After restoration, each molar was cut in half in the oro-vestibular direction between the two restorations, resulting in two specimens per molar. Polyvinylsiloxane impressions were taken and "baseline" replicas were produced. The specimens were then divided into two groups: At the beginning of each month over the course of six months' tap water storage (37°C), one specimen per molar was subjected to mechanical toothbrushing, whereas the other was subjected to thermocycling. After artificial ageing, "final" replicas were produced. Baseline and final replicas were examined under the scanning electron microscope (SEM), and the SEM micrographs were used to determine the percentage of marginal gap formation in enamel or dentin. Paramarginal gaps were registered. The percentages of marginal gap formation were statistically analyzed with a nonparametric analysis of variance followed by Wilcoxon-Mann-Whitney tests and Wilcoxon signed rank tests, and all p-values were corrected with the Bonferroni-Holm adjustment for multiple testing (significance level: α=0.05). Paramarginal gaps were analyzed descriptively. In enamel, significantly lower marginal gap formation was found for Filtek Supreme XTE compared to Filtek Bulk Fill ( p=0.0052) and SDR ( p=0.0289), with no significant difference between Filtek Bulk Fill and SDR ( p=0.4072). In dentin, significantly lower marginal gap formation was found for SDR compared to Filtek Supreme XTE ( p<0.0001) and Filtek Bulk Fill ( p=0.0015), with no significant difference between Filtek Supreme XTE and Filtek Bulk Fill ( p=0.4919). Marginal gap formation in dentin was significantly lower than in enamel ( p<0.0001). The percentage of restorations with paramarginal gaps varied between 0% and 85%, and for all three resin composites the percentages were markedly higher after artificial ageing. The results from this study suggest that in terms of marginal gap formation in enamel, packable resin composites may be superior to flowable "bulk fill" resin composites, while in dentin some flowable "bulk fill" resin composites may be superior to packable ones.

Molecular beam epitaxy grown long wavelength infrared HgCdTe on compliant Si substrates

NASA Astrophysics Data System (ADS)

Wijewarnasuriya, Priyalal S.; Chen, Yuanping; Brill, Gregory; Dhar, Nibir K.; Carmody, Michael; Bailey, Robert; Arias, Jose

2006-05-01

At the Army Research Laboratory (ARL), a new ternary semiconductor system CdSe xTe 1-x/Si(211) is being investigated as an alternative substrate to bulk-grown CdZnTe substrates for HgCdTe growth by molecular beam epitaxy. Under optimized conditions, best layers show surface defect density less than 400 cm -2 and full width at half maximum of X-ray double crystal rocking curve as low as 100 arc-sec with excellent uniformity over 3 inch area. LW-HgCdTe layers on these compliant substrates exhibit comparable electrical properties to those grown on bulk CZT substrates. Photovoltaic devices fabricated on these LWIR material shows diffusion limited performance at 78K indicating high quality material. Measured R °A at 78K on λ co = 10 μm material is on the order of 340 Ω-cm II. In addition to single devices, we have fabricated 256x256 2-D arrays with 40 μm pixel pitch on LW-HgCdTe grown on Si compliant substrates. Data shows excellent QE operability of 99% at 78K under a tactical background flux of 6.7x10 15 ph/cm2sec. Most probable dark current at the peak distribution is 5.5 x 10 9 e-/sec and is very much consistent with the measured R °A values from single devices. Initial results indicate NETD of 33 mK for a cut-off wavelength of 10 μm with 40 micron pixels size. This work demonstrates CdSe xTe 1-x/Si(211) substrates provides a potential road map to more affordable, robust 3 rd generation FPAs.

Superfast Cosmic Jet "Hits the Wall"

NASA Astrophysics Data System (ADS)

1999-01-01

A superfast jet of subatomic particles presumably powered by the gravitational energy of a black hole has collided with nearby material, been slowed dramatically and released much of its energy in the collision, radio astronomers report. The astronomers used the National Science Foundation's Very Large Array (VLA) radio telescope to observe the jet's motion. This is the first time such a collision has been seen within our own Milky Way Galaxy, and the collision may shed new light on the physics of cosmic jets. Robert Hjellming, Michael Rupen and Frank Ghigo of the National Radio Astronomy Observatory (NRAO); Amy Mioduszewski of the Joint Institute for VLBI in Europe; Don Smith of MIT's Space Research Lab; Alan Harmon of Marshall Space Flight Center, and Elizabeth Waltman of the Naval Research Laboratory reported their findings today at the American Astronomical Society's meeting in Austin, TX. The cosmic jet comes from an object called XTE J1748-288, at least 30,000 light-years away in the constellation Sagittarius, near the center of the Milky Way. XTE J1748-288, discovered on June 4, 1998, by Don Smith, using the RXTE satellite, is a "black hole candidate," probably consisting of a black hole drawing material from a companion star and accelerating jets of material outward in the process. A series of VLA images showed a "blob" of material in the jet moving at an apparent speed at least 50 percent greater than that of light. This is only the third such "superluminal" jet seen in our own Galaxy. The apparent faster-than-light motion is an illusion created by geometric effects when jets move at nearly the speed of light and are aligned so that their motion is somewhat toward Earth. The two other Milky Way objects whose jets show such rapid motion are dubbed "microquasars," because their behavior mimics that of quasars -- much larger objects seen at the cores of very distant galaxies. A series of VLA images showed material ejected as a jet from the core of XTE J1748-288. The jet travelled quickly until its advance suddenly was stopped and the endpoint of the jet became brighter than the core. "This fast-moving material obviously hit something," Hjellming said. What did it it hit? "Probably a mixture of external material plus material from a previous jet ejection." Further studies of the collision could yield new information about the physics of cosmic jets. Such jets are believed to be powered by black holes into which material is being drawn. The exact mechanism by which the black hole's gravitational energy accelerates particles to nearly the speed of light is not well understood. There is even dispute about the types of particles ejected. Competing models call for either a mixture of electrons and protons or a mixture of electrons and positrons. Because protons are more than 1,800 times more massive than electrons or positrons (the positively-charged antiparticle of the electron), the electron-proton mixture would be much more massive than the electron-positron pair. Thus, an electron-proton jet is called a heavy jet and an electron-positron jet is called a light jet. A light jet would be much more easily slowed or stopped by tenuous interstellar material than a heavy jet, so the collision of XTE J1748-288's jet may indicate that it is a light jet. "There's still a lot more work to do before anyone can conclude that, but the collision offers the possibility of answering the light-heavy jet question," Hjellming said. A 1998 VLA study by John Wardle of Brandeis University and his colleagues indicated that the jet of a distant quasar is a light, electron-positron jet. Though the black holes in quasars are supermassive, usually millions of times more massive than the Sun, the physics of jet production in them is thought to be similar to the physics of jet production by smaller black holes, only a few times more massive than the sun, such as the one possibly in XTE J1748-288. The VLA is an instrument of the National Radio Astronomy Observatory, a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

NuSTAR AND SWIFT OBSERVATIONS OF THE BLACK HOLE CANDIDATE XTE J1908+094 DURING ITS 2013 OUTBURST

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Lian; Walton, Dominic J.; Fürst, Felix

2015-09-20

The black hole (BH) candidate XTE J1908+094 went into outburst for the first time since 2003 in 2013 October. We report on an observation with the Nuclear Spectroscopic Telescope Array (NuSTAR) and monitoring observations with Swift during the outburst. NuSTAR caught the source in the soft state: the spectra show a broad relativistic iron line, and the light curves reveal a ∼40 ks flare, with the count rate peaking about 40% above the non-flare level and with significant spectral variation. A model combining a multi-temperature thermal component, a power law, and a reflection component with an iron line provides amore » good description of the NuSTAR spectrum. Although relativistic broadening of the iron line is observed, it is not possible to constrain the BH spin with these data. The variability of the power-law component, which can also be modeled as a Comptonization component, is responsible for the flux and spectral change during the flare, suggesting that changes in the corona (or possibly continued jet activity) are the likely cause of the flare.« less

125Te NMR shielding and optoelectronic spectra in XTe3O8 (X = Ti, Zr, Sn and Hf) compounds: Ab initio calculations

NASA Astrophysics Data System (ADS)

Bashi, M.; Rahnamaye Aliabad, H. A.; Mowlavi, A. A.; Ahmad, Iftikhar

2017-11-01

We have calculated the NMR shielding, structural properties and optoelectronic spectra of XTe3O8 (X = Ti, Zr, Sn and Hf) compounds. The full potential linearized augmented plane wave (FP-LAPW) method and the modified Becke-Johnson (mBJ) are used by density functional theory schemes. The calculated shielding and measured shifts are arranged in a straight line and the tensors of magnetic shielding have a low symmetry and the shielding along the x direction is greater than the y and z directions. Obtained results show that the X ions have the most important influence on the 125Te chemical shift. Calculated chemical shielding components (σii) decrease from Ti to Sn then increases from Sn to Hf so that these behaviors are vice versa for 125Te isotropic chemical shift (δiso). Density of states spectra show that the X-p and d states play key role in the optical and NMR calculations. Optical results illustrate that there is a direct relation between the chemical shielding components for Te atom and the static dielectric function, refractive index and Plasmon energies.

Chemical trends of the luminescence in wide band gap II 1-xMn xVI semimagnetic semiconductors

NASA Astrophysics Data System (ADS)

Benecke, C.; Busse, W.; Gumlich, H.-E.

1990-04-01

Time resolved emission and excitation spectroscopy is used to investigate the Mn correlated luminescence in wide band gap II-VI compounds, i.e. Zn 1-xMn xS, Cd 1-xMn xSe, Zn 1-xMn xTe and Cd 1-xMn xTe. Additional Information has been obtained with CdxZnyMnzTe( x+ y+ z=1) in checking the luminescence by variation of the ratio of the cations Cd and Zn. Generally speaking, at least two distinct emissions bands can be observed for each II 1- xMn xVI compound. One emissions band is attributed to the internal transition 4T 1(G)→ 6A 1(S) of the 3d 5 electron of the Mn 2+ on regular metal sites with energies of about ≈2 eV. The other emission band is found to occur in the near infrared range of about ≈1.3 eV. This emission band is tentatively interpreted as a transition of Mn 2+ ions on interstitial sites or in small Mn chalcogenide clusters, both interpretations assuming cubic symmetry. This model is supported by the existence of low energy excitation bands and by the great similarity of the shape of the two emission bands which lead to comparable Huang-Rhys factors and effective phonon energies. Also the established trend in the experimental data of the II-VI compounds under consideration confirm this interpretation. For both the IR and the yellow Mn 2+ center, the Racah parameters B and C and the crystal field parameter Dq are determined on the basis of experimental data. As a result, the energy of both the emission and the excitation bands is predominantly determined by the sorrounding anions. These bands shift to higher energies when the anions are changed in the fixed order: Te→Se→S. Regularly, there is also a spectral shift when Zn is replaced by Cd, which is smaller than the shift due to the variation of onions.

Atomic-Scale Visualization of Quasiparticle Interference on a Type-II Weyl Semimetal Surface.

PubMed

Zheng, Hao; Bian, Guang; Chang, Guoqing; Lu, Hong; Xu, Su-Yang; Wang, Guangqiang; Chang, Tay-Rong; Zhang, Songtian; Belopolski, Ilya; Alidoust, Nasser; Sanchez, Daniel S; Song, Fengqi; Jeng, Horng-Tay; Yao, Nan; Bansil, Arun; Jia, Shuang; Lin, Hsin; Hasan, M Zahid

2016-12-23

We combine quasiparticle interference simulation (theory) and atomic resolution scanning tunneling spectromicroscopy (experiment) to visualize the interference patterns on a type-II Weyl semimetal Mo_{x}W_{1-x}Te_{2} for the first time. Our simulation based on first-principles band topology theoretically reveals the surface electron scattering behavior. We identify the topological Fermi arc states and reveal the scattering properties of the surface states in Mo_{0.66}W_{0.34}Te_{2}. In addition, our result reveals an experimental signature of the topology via the interconnectivity of bulk and surface states, which is essential for understanding the unusual nature of this material.

Superconductivity, Pairing Symmetry, and Disorder in the Doped Topological Insulator Sn 1-xIn xTe for x >= 0.10.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smylie, M. P.; Claus, H.; Kwok, W. -K.

The temperature dependence of the London penetration depth Delta lambda(T) in the superconducting doped topological crystalline insulator Sn1-xInxTe was measured down to 450 mK for two different doping levels, x approximate to 0.45 (optimally doped) and x approximate to 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. The introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T-c, indicating that ferroelectric interactions domore » not compete with superconductivity.« less

Chevrel-phase solid solution Mo 6Se 8- xTe x. Study of its superconducting, magnetic and NMR properties

NASA Astrophysics Data System (ADS)

Hamard1a, C.; Auffret, V.; Peña, O.; Le Floch, M.; Nowak, B.; Wojakowski, A.

2000-09-01

The Chevrel-phase solid solution Mo 6Se 8-Mo 6Te 8 was studied by X-ray diffraction, AC and DC magnetic susceptibility and 77Se and 125Te NMR spectroscopy. From the smooth evolution of the lattice parameters and superconducting critical temperatures, a progressive substitution of selenium atoms by tellurium is shown, on the whole range of composition 0⩽ x⩽8, in the formulation Mo 6Se 8- xTe x: the unit-cell volume increases linearly because of the larger ionic size of tellurium, while Tc decreases rapidly (from 6.45 down to 0 K) because of the different formal oxidation states of the anions and a probable evolution of the Fermi level in the density of states. Results of magnetic susceptibility support this model and suggest the inhibition of the intrinsic metallic behavior with increasing x. The NMR spectra of the binaries Mo 6Se 8 and Mo 6Te 8 reveal two significant features, attributed to two different chalcogen positions in the R 3¯ symmetry. At low Se contents in Mo 6Se 8- xTe x ( x=7.5, 7 and 6), selenium first fills the two X(2) sites along the three-fold axis (2c positions), and then it becomes statistically distributed over the general 6f positions, leading to broad 77Se NMR lines. On the other hand, substitution of Te atoms in Mo 6Se 8 seems to occur in a random way, creating large perturbations on the 125Te NMR spectra, over the whole range of x. Theoretical analysis based on the presence of two anisotropic lines (of axial and non-axial symmetries, respectively) allowed us to estimate their anisotropy factors and to perfectly simulate the frequency response of both Mo 6Se 8 and Mo 6Te 8 binaries. Analysis of the Knight shift anisotropy leads us to conclude about the importance of the molybdenum z 2 molecular orbital contribution which controls the Mo-X dipolar interactions.

The boron implantation in the varied zone MBE MCT epilayer

NASA Astrophysics Data System (ADS)

Voitsekhovskii, Alexander V.; Grigor'ev, Denis V.; Kokhanenko, Andrey P.; Korotaev, Alexander G.; Sidorov, Yuriy G.; Varavin, Vasiliy S.; Dvoretsky, Sergey A.; Mikhailov, Nicolay N.; Talipov, Niyaz Kh.

2005-09-01

In the paper experimental results on boron implantation of the CdxHg1-xTe epilayers with various composition near surface of the material are discussed. The electron concentration in the surface layer after irradiation vs irradiation dose and ion energy are investigated for range of doses 1011 - 3•1015 cm-2 and energies of 20 - 150 keV. Also the results of the electrical active defects distribution measurement, carried out by differential Hall method, after boron implantation are represented. Consideration of the received data shows, that composition gradient influence mainly on the various dynamics of accumulation of electric active radiation defects. The electric active defects distribution analysis shows, that the other factors are negligible.

Crystal growth, fabrication and evaluation of cadmium manganese telluride gamma ray detectors

NASA Astrophysics Data System (ADS)

Burger, Arnold; Chattopadhyay, Kaushik; Chen, Henry; Olivier Ndap, Jean; Ma, Xiaoyan; Trivedi, Sudhir; Kutcher, Susan W.; Chen, Rujin; Rosemeier, Robert D.

1999-03-01

Cadmium manganese telluride (Cd 1- xMn xTe) is a diluted magnetic semiconductor material which forms the basis for many important devices such as IR detectors, solar cells, magnetic field sensors, optical isolators, and visible and near IR lasers. High resistivity (>10 10 Ω cm) and high μ τ (>10 -6 cm 2/V) material, which are the two prerequisites in the fabrication of radiation detectors, has recently been demonstrated at Brimrose Corp. This paper presents the crystal growth of intentionally vanadium doped crystals, the surface preparation and contacting procedure, as well as the best detector performance obtained so far. Dark current characteristics, and low temperature photoluminescence results are also presented and discussed.

On the Detectability of CO Molecules in the Interstellar Medium via X-Ray Spectroscopy

NASA Technical Reports Server (NTRS)

Joachimi, Katerine; Gatuzz, Efrain; Garcia, Javier; Kallman, Timothy R.

2016-01-01

We present a study of the detectability of CO molecules in the Galactic interstellar medium using high-resolution X-ray spectra obtained with the XMM-Newton Reflection Grating Spectrometer. We analysed 10 bright low mass X-ray binaries (LMXBs) to study the CO contribution in their line of sights. A total of 25 observations were fitted with the ISMabs X-ray absorption model which includes photoabsorption cross-sections for Oi, Oii, Oiii and CO. We performed a Monte Carlo (MC) simulation analysis of the goodness of fit in order to estimate the significance of the CO detection. We determine that the statistical analysis prevents a significant detection of CO molecular X-ray absorption features, except for the lines of sight towards XTE J1718-330 and 4U 1636-53. In the case of XTE J1817-330, this is the first report of the presence of CO along its line of sight. Our results reinforce the conclusion that molecules have a minor contribution to the absorption features in the O K-edge spectral region. We estimate a CO column density lower limit to perform a significant detection with XMM-Newton of N(CO) greater than 6 x 10(exp 16) per sq cm for typical exposure times.

NASA's spacecraft data system

NASA Technical Reports Server (NTRS)

Cudmore, Alan; Flanegan, Mark

1993-01-01

The NASA Small Explorer Data System (SEDS), a space flight data system developed to support the Small Explorer (SMEX) project, is addressed. The system was flown on the Solar Anomalous Magnetospheric Particle Explorer (SAMPEX) SMEX mission, and with reconfiguration for different requirements will fly on the X-ray Timing Explorer (XTE) and the Tropical Rainfall Measuring Mission (TRMM). SEDS is also foreseen for the Hubble repair mission. Its name was changed to Spacecraft Data System (SDS) in view of expansions. Objectives, SDS hardware, and software are described. Each SDS box contains two computers, data storage memory, uplink (command) reception circuitry, downlink (telemetry) encoding circuitry, Instrument Telemetry Controller (ITC), and spacecraft timing circuitry. The SDS communicates with other subsystems over the MIL-STD-1773 data bus. The SDS software uses a real time Operating System (OS) and the C language. The OS layer, communications and scheduling layer, application task layer, and diagnostic software, are described. Decisions on the use of advanced technologies, such as ASIC's (Application Specific Integrated Circuits) and fiber optics, led to technical improvements, such as lower power and weight, without increasing the risk associated with the data system. The result was a successful SAMPEX development, integration and test, and mission using SEDS, and the upgrading of that system to SDS for TRMM and XTE.

Efficient long wavelength interband photoluminescence from HgCdTe epitaxial films at wavelengths up to 26 μm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozov, S. V.; Rumyantsev, V. V., E-mail: rumyantsev@ipmras.ru; Antonov, A. V.

2014-02-17

Photoluminescence (PL) and photoconductivity (PC) studies of Hg{sub 1−x}Cd{sub x}Te (0.19 ≤ x ≤ 0.23) epitaxial films are presented. Interband PL is observed at wavelengths from 26 to 6 μm and in the temperature range 18 K–200 K. The PL line full width at half maximum is about 6 meV (4kT) at 18 K and approaches its theoretical limit of 1.8kT at higher temperatures. Carrier recombination process is also investigated by time resolved studies of PL and PC at pulsed excitation. Radiative transitions are shown to be the dominating mechanism of carrier recombination at high excitation levels.

High field conduction in Pb doped amorphous Se-Te system

NASA Astrophysics Data System (ADS)

Anjali, Patial, Balbir Singh; Thakur, Nagesh

2018-05-01

In the present study, DC conductivity measurements of as-Se80-xTe20Pbx (x = 0, 1 and 2) glassy alloys are made in the temperature range 298-318 K and in the voltage range 0-180 V. Current-voltage (I-V) characteristics point toward ohmic behavior at low electric field and non-ohmic is observed at high electric field. The variation of ln(I/V) against V are nearly found straight curves but slope of these curves does not decrease linearly with temperature indicates that the space charge limited conduction (SCLC) is absent. Instead the linear relation between ln(I) and V1/2 confirms that the conduction is either Poole-Frenkel type or Schottky emission. A detailed analysis shows that the dominant mechanism is Poole-Frenkel type conduction.

Analysis of variability in the burst oscillations of the accreting millisecond pulsar XTE J1814-338

NASA Technical Reports Server (NTRS)

Watts, Anna L.; Strohmayer, Tod E.; Markwardt, Craig B.

2005-01-01

The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We present an analysis of the variability of the burst oscillations of this source, focusing on three characteristics: fractional amplitude, harmonic content and frequency. Fractional amplitude and harmonic content constrain the size, shape and position of the emitting region, whilst variations in frequency indicate motion of the emitting region on the neutron star surface. We examine both long-term variability over the course of the outburst, and short-term variability during the bursts. For most of the bursts, fractional amplitude is consistent with that of the accretion pulsations, implying a low degree of fuel spread. There is however a population of bursts whose fractional amplitudes are substantially lower, implying a higher degree of fuel spread, possibly forced by the explosive burning front of a precursor burst. For the first harmonic, substantial differences between the burst and accretion pulsations suggest that hotspot geometry is not the only mechanism giving rise to harmonic content in the latter. Fractional amplitude variability during the bursts is low; we can only rule out the hypothesis that the fractional amplitude remains constant at the l(sigma) level for bursts that do not exhibit photospheric radius expansion (PRE). There are no significant variations in frequency in any of the bursts except for the one burst that exhibits PRE. This burst exhibits a highly significant but small (= 0.1Hz) drop in frequency in the burst rise. The timescale of the frequency shift is slower than simple burning layer expansion models predict, suggesting that other mechanisms may be at work.

Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn 1 - x In x Te for x ≥ 0.10

DOE PAGES

Smylie, M. P.; Claus, H.; Kwok, W. -K.; ...

2018-01-19

In this paper, the temperature dependence of the London penetration depth Δλ(T) in the superconducting doped topological crystalline insulator Sn 1-xIn xTe was measured down to 450 mK for two different doping levels, x ≈ 0.45 (optimally doped) and x ≈ 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. Finally, the introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T c, indicatingmore » that ferroelectric interactions do not compete with superconductivity.« less

Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn 1 - x In x Te for x ≥ 0.10

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smylie, M. P.; Claus, H.; Kwok, W. -K.

In this paper, the temperature dependence of the London penetration depth Δλ(T) in the superconducting doped topological crystalline insulator Sn 1-xIn xTe was measured down to 450 mK for two different doping levels, x ≈ 0.45 (optimally doped) and x ≈ 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. Finally, the introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T c, indicatingmore » that ferroelectric interactions do not compete with superconductivity.« less

Chandra Pinpoints Edge Of Accretion Disk Around Black Hole

NASA Astrophysics Data System (ADS)

2001-05-01

Using four NASA space observatories, astronomers have shown that a flaring black hole source has an accretion disk that stops much farther out than some theories predict. This provides a better understanding of how energy is released when matter spirals into a black hole. On April 18, 2000, the Hubble Space Telescope and the Extreme Ultraviolet Explorer observed ultraviolet radiation from the object known as XTE J1118+480, a black hole roughly seven times the mass of the Sun, locked in a close binary orbit with a Sun-like star. Simultaneously, the Rossi X-ray Timing Explorer observed high-energy X-rays from matter plunging toward the black hole, while the Chandra X-ray Observatory focused on the critical energy band between the ultraviolet and high-energy X-rays, providing the link that tied all the data together. "By combining the observations of XTE J1118+480 at many different wavelengths, we have found the first clear evidence that the accretion disk can stop farther out," said Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics who led the Chandra observations. "The Chandra data indicate that this accretion disk gets no closer to the event horizon than about 600 miles, a far cry from the 25 miles that some had expected." Scientists theorize that the accretion disk is truncated there because the material erupts into a hot bubble of gas before taking its final plunge into the black hole. Matter stripped from a companion star by a black hole can form a flat, pancake-like structure, called an “accretion disk.” As material spirals toward the inner edge of the accretion disk, it is heated by the immense gravity of the black hole, which causes it to radiate in X-rays. By examining the X-rays, researchers can gauge how far inward the accretion disk extends. Most astronomers agree that when material is transferred onto the black hole at a high rate, then the accretion disk will reach to within about 25 miles of the event horizon -- the surface of “no return” for matter or light falling into a black hole. However, scientists disagree on how close the accretion disk comes when the rate of transfer is much less. "The breakthrough came when Chandra did not detect the X-ray signature one would expect if the accretion disk came as near as 25 miles," said Ann Esin, a Caltech theoretical astrophysicist who led a group that explored the implications of the observations. "This presents a fundamental problem for models in which the disk extends close to the event horizon." In March 2000, XTE J1118+480 experienced a sudden eruption in X-rays that led to the discovery of the object by RXTE. The X-ray source was in a direction where absorption by gas and dust was minimal, allowing ultraviolet and low-energy X-rays to be observed. In the following month, an international team organized observations of XTE J1118+480 in other wavelengths. Chandra observed XTE J1118+480 for 27,000 seconds with its Low-Energy Transmission Grating (LETG) and the Advanced CCD Imaging Spectrometer (ACIS). The research team for this investigation also included scientists from both the United States (CfA, MIT, University of Notre Dame, Lawrence Livermore National Laboratory, NASA Goddard Space Flight Center) and the United Kingdom (The Open University, University of Southampton, Mullard Radio Astronomy Observatory). The LETG was built by the SRON and the Max Planck Institute, and the ACIS instrument by the Massachusetts Institute of Technology, Cambridge, Mass., and Penn State University, University Park. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Design principles for HgTe based topological insulator devices

NASA Astrophysics Data System (ADS)

Sengupta, Parijat; Kubis, Tillmann; Tan, Yaohua; Povolotskyi, Michael; Klimeck, Gerhard

2013-07-01

The topological insulator properties of CdTe/HgTe/CdTe quantum wells are theoretically studied. The CdTe/HgTe/CdTe quantum well behaves as a topological insulator beyond a critical well width dimension. It is shown that if the barrier (CdTe) and well-region (HgTe) are altered by replacing them with the alloy CdxHg1-xTe of various stoichiometries, the critical width can be changed. The critical quantum well width is shown to depend on temperature, applied stress, growth directions, and external electric fields. Based on these results, a novel device concept is proposed that allows to switch between a normal semiconducting and topological insulator state through application of moderate external electric fields.

Tuning the electrical transport of type II Weyl semimetal WTe2 nanodevices by Mo doping

NASA Astrophysics Data System (ADS)

Fu, Dongzhi; Pan, Xingchen; Bai, Zhanbin; Fei, Fucong; Umana-Membreno, Gilberto A.; Song, Honglian; Wang, Xuelin; Wang, Baigeng; Song, Fengqi

2018-04-01

We fabricated nanodevices from MoxW1-xTe2 (x = 0, 0.07, 0.35), and conducted a systematic comparative study of their electrical transport. Magnetoresistance measurements show that Mo doping can significantly suppress mobility and magnetoresistance. The results for the analysis of the two band model show that doping with Mo does not break the carrier balance. Through analysis of Shubnikov-de Haas oscillations, we found that Mo doping also has a strong suppressive effect on the quantum oscillation of the sample, and the higher the ratio of Mo, the fewer pockets were observed in our experiments. Furthermore, the effective mass of electron and hole increases gradually with increasing Mo ratio, while the corresponding quantum mobility decreases rapidly.

High energy from space

NASA Technical Reports Server (NTRS)

Margon, Bruce; Canizares, Claude; Catura, Richard C.; Clark, George W.; Fichtel, Carl E.; Friedman, Herbert; Giacconi, Riccardo; Grindlay, Jonathan E.; Helfand, David J.; Holt, Stephen S.

1991-01-01

The following subject areas are covered: (1) important scientific problems for high energy astrophysics (stellar activity, the interstellar medium in galaxies, supernovae and endpoints of stellar evolution, nucleosynthesis, relativistic plasmas and matter under extreme conditions, nature of gamma-bursts, identification of black holes, active nuclei, accretion physics, large-scale structures, intracluster medium, nature of dark matter, and the X- and gamma-ray background); (2) the existing experimental programs (Advanced X-Ray Astrophysics Facility (AXAF), Gamma Ray Observatory (GRO), X-Ray Timing Explorer (XTE), High Energy Transient Experiment (HETE), U.S. participation in foreign missions, and attached Shuttle and Space Station Freedom payloads); (3) major missions for the 1990's; (4) a new program of moderate missions; (5) new opportunities for small missions; (6) technology development issues; and (7) policy issues.

YC-15 Interior Noise Measurements. Technical Discussion.

DTIC Science & Technology

1981-03-01

almost equal chord segments of the flap. The spoilers ahead of the flap are drooped as a function of flap motion to main- tain an effective slot...fan and primary exhaust air with freestream air to produce rapid temperature and velocity reduction and to spread the exhaust wake over a large span of...PRESSURESMAme Model AR- 200 Kulie Doglas14 Channel Mode XTE19010 D gital ataTape Transducer Signal Condition- INLET ACOUSTICS AND ~ odI ing Amplfiers

Evidence of Spin and Energy Extraction in a Galactic Black Hole Candidate: The XMM-NEWTON/EPIC SPECTRUM of XTE 11650-500

NASA Technical Reports Server (NTRS)

Miller, J. M.; Fabian, A. C.; Wunands, R.; Reynolds, C. S.; Ehle, M.; Freyberg, M. J.; VanDerKlis, M.; Lewin, W. H. G.; Sanchez-Fernandez, C.; Castro-Tirado, A. J.

2002-01-01

We observed the Galactic black hole candidate XTE J1650-500 early in its fall of 2001 outburst with the XMM-Newton European Photon Imaging pn Camera (EPIC-pn). The observed spectrum is consistent with the source having been in the very high state. We h d a broad, skewed Fe Kar emission line that suggests the primary in this system may be a Kerr black hole and that indicates a steep disk emissivity profile that is hard to explain in terms of a standard accretion disk model. These results are quantitatively and qualitatively similar to those from an XMM-Newton observation of the Seyfert galaxy MCG -6-30-15. The steep emissivity in MCG -6-30-15 may be explained by the extraction and dissipation of rotational energy from a black hole with nearly maximal angular momentum or from material in the plunging region via magnetic connections to the inner accretion disk. If this process is at work in both sources, an exotic but fundamental general relativistic prediction may be confirmed across a factor of l0(exp 6) in black hole mass. We discuss these results in terms of the accretion flow geometry in stellar-mass black holes and the variety of enigmatic phenomena often observed in the very high state.

High Energy Astrophysics Program

NASA Technical Reports Server (NTRS)

1996-01-01

This report reviews activities performed-by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, visiting the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA); X-ray Timing Experiment (XTE); X-ray Spectrometer (XRS); Astro-E; High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

High Energy Astrophysics Research and Programmatic Support

NASA Technical Reports Server (NTRS)

Angelini, Lorella

1998-01-01

This report reviews activities performed by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

High Energy Astrophysics Program (HEAP)

NASA Technical Reports Server (NTRS)

Angelini, Lorella; Corcoran, Michael; Drake, Stephen; McGlynn, Thomas A.; Snowden, Stephen; Mukai, Koji; Cannizzo, John; Lochner, James; Rots, Arnold; Christian, Eric;

High Energy Astrophysics Program (HEAP)

NASA Technical Reports Server (NTRS)

Angelini, L.

1998-01-01

This report reviews activities performed by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

High Energy Astrophysics Research and Programmatic Support

NASA Technical Reports Server (NTRS)

Angelini, L. (Editor)

1997-01-01

This report reviews activities performed by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

Optimization of Monocrystalline MgxCd1-xTe/MgyCd1-yTe Double-Heterostructure Solar Cells

NASA Astrophysics Data System (ADS)

Becker, Jacob J.

Polycrystalline CdS/CdTe solar cells continue to dominate the thin-film photovoltaics industry with an achieved record efficiency of over 22% demonstrated by First Solar, yet monocrystalline CdTe devices have received considerably less attention over the years. Monocrystalline CdTe double-heterostructure solar cells show great promise with respect to addressing the problem of low Voc with the passing of the 1 V benchmark. Rapid progress has been made in driving the efficiency in these devices ever closer to the record presently held by polycrystalline thin-films. This achievement is primarily due to the utilization of a remote p-n heterojunction in which the heavily doped contact materials, which are so problematic in terms of increasing non-radiative recombination inside the absorber, are moved outside of the CdTe double heterostructure with two MgyCd1-yTe barrier layers to provide confinement and passivation at the CdTe surfaces. Using this design, the pursuit and demonstration of efficiencies beyond 20% in CdTe solar cells is reported through the study and optimization of the structure barriers, contacts layers, and optical design. Further development of a wider bandgap MgxCd1-xTe solar cell based on the same design is included with the intention of applying this knowledge to the development of a tandem solar cell constructed on a silicon subcell. The exploration of different hole-contact materials--ZnTe, CuZnS, and a-Si:H--and their optimization is presented throughout the work. Devices utilizing a-Si:H hole contacts exhibit open-circuit voltages of up to 1.11 V, a maximum total-area efficiency of 18.5% measured under AM1.5G, and an active-area efficiency of 20.3% for CdTe absorber based devices. The achievement of voltages beyond 1.1V while still maintaining relatively high fill factors with no rollover, either before or after open-circuit, is a promising indicator that this approach can result in devices surpassing the 22% record set by polycrystalline designs. MgxCd1-xTe absorber based devices have been demonstrated with open-circuit voltages of up to 1.176 V and a maximum active-area efficiency of 11.2%. A discussion of the various loss mechanisms present within these devices, both optical and electrical, concludes with the presentation of a series of potential design changes meant to address these issues.

High Compositional Homogeneity of CdTe xSe 1-x Crystals Grown by the Bridgman Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, U. N.; Bolotnikov, A. E.; Camarda, G. S.

2015-02-03

We obtained high-quality CdTe xSe 1-x (CdTeSe) crystals from ingots grown by the vertical Bridgman technique. The compositional uniformity of the ingots was evaluated by X-ray fluorescence at BNL’s National Synchrotron Light Source X27A beam line. The resulting compositional homogeneity was highly uniform throughout the ingot, and the effective segregation coefficient of Se was ~1.0. This uniformity offers potential opportunity to enhance the yield of the materials for both infrared substrate and radiation-detector applications, so greatly lowering the cost of production and also offering us the prospect to grow large-diameter ingots for use as large-area substrates and for producing highermore » efficiency gamma-ray detectors. The concentration of secondary phases was found to be much lower, by eight- to ten fold compared to that of conventional Cd xZn 1-xTe (CdZnTe or CZT).« less

Photoionization Modeling of Oxygen K Absorption in the Interstellar Medium: The Chandra Grating Spectra of XTE J1817-330

NASA Technical Reports Server (NTRS)

Gatuzz, E.; Garcia, J.; Menodza, C.; Kallman, T. R.; Witthoeft, M.; Lohfink, A.; Bautista, M. A.; Palmeri, P.; Quinet, P.

2013-01-01

We present detailed analyses of oxygen K absorption in the interstellar medium (ISM) using four high-resolution Chandra spectra towards the X-ray low-mass binary XTE J1817-330. The 11-25 A broadband is described with a simple absorption model that takes into account the pileup effect and results in an estimate of the hydrogen column density. The oxygen K-edge region (21-25 A) is fitted with the physical warmabs model, which is based on a photoionization model grid generated with the XSTAR code with the most up-to-date atomic database. This approach allows a benchmark of the atomic data which involves wavelength shifts of both the K lines and photoionization cross sections in order to fit the observed spectra accurately. As a result we obtain: a column density of N(sub H) = 1.38 +/- 0.01 x 10(exp 21) cm(exp -2); ionization parameter of log xi = .2.70 +/- 0.023; oxygen abundance of A(sub O) = 0.689(exp +0.015./-0.010); and ionization fractions of O I/O = 0.911, O II/O = 0.077, and O III/O = 0.012 that are in good agreement with previous studies. Since the oxygen abundance in warmabs is given relative to the solar standard of Grevesse and Sauval (1998), a rescaling with the revision by Asplund et al. (2009) yields A(sub O) = 0.952(exp +0.020/-0.013, a value close to solar that reinforces the new standard. We identify several atomic absorption lines.K-alpha , K-beta, and K-gamma in O I and O II; and K-alpha in O III, O VI, and O VII--last two probably residing in the neighborhood of the source rather than in the ISM. This is the first firm detection of oxygen K resonances with principal quantum numbers n greater than 2 associated to ISM cold absorption.

Photoionization Modeling of Oxygen K Absorption in the Interstellar Medium:. [The Chandra Grating Spectra of XTE J1817-330

NASA Technical Reports Server (NTRS)

Gatuzz, E.; Garcia, J.; Mendoza, C.; Kallman, T. R.; Witthoeft, M.; Lohfink, A.; Bautista, M. A.; Palmeri, P.; Quinet, P.

2013-01-01

We present detailed analyses of oxygen K absorption in the interstellar medium (ISM) using four high-resolution Chandra spectra toward the X-ray low-mass binary XTE J1817-330. The 11-25 Angstrom broadband is described with a simple absorption model that takes into account the pile-up effect and results in an estimate of the hydrogen column density. The oxygen K-edge region (21-25 Angstroms) is fitted with the physical warmabs model, which is based on a photoionization model grid generated with the xstar code with the most up-to-date atomic database. This approach allows a benchmark of the atomic data which involves wavelength shifts of both the K lines and photoionization cross sections in order to fit the observed spectra accurately. As a result we obtain a column density of N(sub H) = 1.38 +/- 0.01 × 10(exp 21) cm(exp -2); an ionization parameter of log xi = -2.70 +/- 0.023; an oxygen abundance of A(sub O) = 0.689 (+0.015/-0.010); and ionization fractions of O(sub I)/O = 0.911, O(sub II)/O = 0.077, and O(sub III)/O = 0.012 that are in good agreement with results from previous studies. Since the oxygen abundance in warmabs is given relative to the solar standard of Grevesse & Sauval, a rescaling with the revision by Asplund et al. yields A(sub O) = 0.952(+0.020/-0.013), a value close to solar that reinforces the new standard.We identify several atomic absorption lines-K(alpha), K(beta), and K(gamma) in O(sub I) and O(sub II) and K(alpha) in O(sub III), O(sub VI), and O(sub VII)-the last two probably residing in the neighborhood of the source rather than in the ISM. This is the first firm detection of oxygen K resonances with principal quantum numbers n greater than 2 associated with ISM cold absorption.

SPECTRAL STATES OF XTE J1701 - 462: LINK BETWEEN Z AND ATOLL SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin Dacheng; Remillard, Ronald A.; Homan, Jeroen

2009-05-10

We have analyzed 866 Rossi X-ray Timing Explorer observations of the 2006-2007 outburst of the accreting neutron star XTE J1701 -462, during which the source evolves from super-Eddington luminosities to quiescence. The X-ray color evolution first resembles the Cyg X-2 subgroup of Z sources, with frequent excursions on the horizontal and normal branches (HB/NB). The source then decays and evolves to the Sco X-1 subgroup, with increasing focus on the flaring branch (FB) and the lower vertex of the 'Z'. Finally, the FB subsides, and the source transforms into an atoll source, with the lower vertex evolving to the atollmore » soft state. Spectral analyses suggest that the atoll stage is characterized by a constant inner disk radius, while the Z stages exhibit a luminosity-dependent expansion of the inner disk, which we interpret as effects related to the local Eddington limit. Contrary to the view that the mass accretion rate m-dot changes along the Z, we find that changes in m-dot are instead responsible for the secular evolution of the Z and the subclasses. Motion along the Z branches appears to be caused by three different mechanisms that may operate at roughly constant m-dot. For the Sco X-1-like Z stage, we find that the FB is an instability track that proceeds off the lower vertex when the inner disk radius shrinks from the value set by the X-ray luminosity toward the value measured for the atoll soft state. Excursions up the NB occur when the apparent size of the boundary layer increases while the disk exhibits little change. The HB is associated with Comptonization of the disk emission. The Z branches for the Cyg X-2-like stage are more complicated, and their origin is unclear. Finally, our spectral results lead us to hypothesize that the lower and upper Z vertices correspond to a standard thin disk and a slim disk, respectively.« less

Interactive Dynamic Mission Scheduling for ASCA

NASA Astrophysics Data System (ADS)

Antunes, A.; Nagase, F.; Isobe, T.

The Japanese X-ray astronomy satellite ASCA (Advanced Satellite for Cosmology and Astrophysics) mission requires scheduling for each 6-month observation phase, further broken down into weekly schedules at a few minutes resolution. Two tools, SPIKE and NEEDLE, written in Lisp and C, use artificial intelligence (AI) techniques combined with a graphic user interface for fast creation and alteration of mission schedules. These programs consider viewing and satellite attitude constraints as well as observer-requested criteria and present an optimized set of solutions for review by the planner. Six-month schedules at 1 day resolution are created for an oversubscribed set of targets by the SPIKE software, originally written for HST and presently being adapted for EUVE, XTE and AXAF. The NEEDLE code creates weekly schedules at 1 min resolution using in-house orbital routines and creates output for processing by the command generation software. Schedule creation on both the long- and short-term scale is rapid, less than 1 day for long-term, and one hour for short-term.

Thermoelectric properties of n-type polycrystalline BixSb2-xTe3 alloys

NASA Technical Reports Server (NTRS)

Snyder, J.; Gerovac, N.; Caillat, T.

2002-01-01

(BixSbl-x)2Te3(.5 = x = .7) polycrystalline samples were synthesized using a combination of melting and powder metallurgy techniques. The samples were hot pressed in graphite dies and cut perpendicular and parallel to the pressing direction. Samples were examined by microprobe analysis to determine their atomic composition. The thermoelectric properties were measured at room temperature in both directions. These properties include Seebeck coefficient, thermal conductivity, electrical resistivity, and Hall effect. The thermoelectric figure-of-merit, ZT, was calculated fiom these properties.

High Energy Astrophysics Program

NASA Technical Reports Server (NTRS)

1996-01-01

This report reviews activities performed by members of the USRA (Universities Space Research Association) contract team during the six months during the reporting period (10/95 - 3/96) and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science, Archive Research Center (HEASARC), and others.

Color stability of esthetic restorative materials: a spectrophotometric analysis.

PubMed

Poggio, Claudio; Ceci, Matteo; Beltrami, Riccardo; Mirando, Maria; Wassim, Jaffal; Colombo, Marco

2016-12-01

Objective: The aim of this in vitro study was to evaluate the color stability of different restorative materials (one microfilled composite, one nanofilled composite, one nanohybrid composite and one Ormocer-based composite) after exposure to different staining solutions (coffee, coca-cola and red wine). Material and methods: All materials were polymerized into silicon rings (2 mm ×6 mm ×8 mm) to obtain specimens identical in size. Thirty cylindrical specimens of each material were prepared. They were immersed in staining solutions over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. The Shapiro-Wilk test and Kruskal-Wallis ANOVA were applied to assess significant differences among restorative materials. The paired t -test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. Results: All restorative materials showed clinically perceptible color differences after immersion in coffee. L* and b* values showed the highest variability. Coca cola and red wine did not influence the color stability for all restorative materials except for Filtek Supreme XTE. Conclusions: Coffee caused a significant color change in all types of tested composite resins. Filtek Supreme XTE demonstrated alone a staining susceptibility to red wine; no other significant differences among the materials were demonstrated. Long-term exposure to some food dyes (coffee in particular) can significantly affect the color stability of modern esthetic restorative materials regardless of materials' different composition.

TEMPORAL VARIABILITY FROM THE TWO-COMPONENT ADVECTIVE FLOW SOLUTION AND ITS OBSERVATIONAL EVIDENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dutta, Broja G.; Chakrabarti, Sandip K.

2016-09-10

In the propagating oscillatory shock model, the oscillation of the post-shock region, i.e., the Compton cloud, causes the observed low-frequency quasi-periodic oscillations (QPOs). The evolution of QPO frequency is explained by the systematic variation of the Compton cloud size, i.e., the steady radial movement of the shock front, which is triggered by the cooling of the post-shock region. Thus, analysis of the energy-dependent temporal properties in different variability timescales can diagnose the dynamics and geometry of accretion flows around black holes. We study these properties for the high-inclination black hole source XTE J1550-564 during its 1998 outburst and the low-inclinationmore » black hole source GX 339-4 during its 2006–07 outburst using RXTE /PCA data, and we find that they can satisfactorily explain the time lags associated with the QPOs from these systems. We find a smooth decrease of the time lag as a function of time in the rising phase of both sources. In the declining phase, the time lag increases with time. We find a systematic evolution of QPO frequency and hard lags in these outbursts. In XTE J1550-564, the lag changes from hard to soft (i.e., from a positive to a negative value) at a crossing frequency (ν {sub c}) of ∼3.4 Hz. We present possible mechanisms to explain the lag behavior of high and low-inclination sources within the framework of a single two-component advective flow model.« less

A tool to separate optical/infrared disc and jet emission in X-ray transient outbursts: the colour-magnitude diagrams of XTE J1550-564

NASA Astrophysics Data System (ADS)

Russell, D. M.; Maitra, D.; Dunn, R. J. H.; Fender, R. P.

2011-09-01

It is now established that thermal disc emission and non-thermal jet emission can both play a role at optical/infrared (OIR) wavelengths in X-ray transients. The spectra of the jet and disc components differ, as do their dependence on mass accretion properties. Here we demonstrate that the OIR colour-magnitude diagrams (CMDs) of the evolution of the X-ray transient XTE J1550-564 in outburst can be used to separate the disc from the jet. Monitoring in two wavebands is all that is required. This outburst in 2000 was well studied, and both disc and jet were known to contribute. During the outburst the data follow a well-defined path in the CMD, describing what would be expected from a heated single-temperature blackbody of approximately constant area, except when the data appear redder than this track. This is due to the non-thermal jet component which dominates the OIR moreso during hard X-ray states at high luminosities, and which is quenched in the soft state. The CMD therefore shows state-dependent hysteresis, in analogy with (but not identical to) the well-established X-ray hardness-intensity diagram of black hole transients. The blackbody originates in the X-ray illuminated, likely unwarped, outer accretion disc. We show that the CMD can be approximately reproduced by a model that assumes various correlations between X-ray, OIR disc and OIR jet fluxes. We find evidence for the OIR jet emission to be decoupled from the disc near the peak of the hard state.

Current-Nonlinear Hall Effect and Spin-Orbit Torque Magnetization Switching in a Magnetic Topological Insulator

NASA Astrophysics Data System (ADS)

Yasuda, K.; Tsukazaki, A.; Yoshimi, R.; Kondou, K.; Takahashi, K. S.; Otani, Y.; Kawasaki, M.; Tokura, Y.

2017-09-01

The current-nonlinear Hall effect or second harmonic Hall voltage is widely used as one of the methods for estimating charge-spin conversion efficiency, which is attributed to the magnetization oscillation by spin-orbit torque (SOT). Here, we argue the second harmonic Hall voltage under a large in-plane magnetic field with an in-plane magnetization configuration in magnetic-nonmagnetic topological insulator (TI) heterostructures, Crx (Bi1 -ySby )2 -xTe3 /(Bi1 -ySby )2Te3 , where it is clearly shown that the large second harmonic voltage is governed not by SOT but mainly by asymmetric magnon scattering without macroscopic magnetization oscillation. Thus, this method does not allow an accurate estimation of charge-spin conversion efficiency in TI. Instead, the SOT contribution is exemplified by current pulse induced nonvolatile magnetization switching, which is realized with a current density of 2.5 ×1010 A m-2 , showing its potential as a spintronic material.

Current-Nonlinear Hall Effect and Spin-Orbit Torque Magnetization Switching in a Magnetic Topological Insulator.

PubMed

Yasuda, K; Tsukazaki, A; Yoshimi, R; Kondou, K; Takahashi, K S; Otani, Y; Kawasaki, M; Tokura, Y

2017-09-29

The current-nonlinear Hall effect or second harmonic Hall voltage is widely used as one of the methods for estimating charge-spin conversion efficiency, which is attributed to the magnetization oscillation by spin-orbit torque (SOT). Here, we argue the second harmonic Hall voltage under a large in-plane magnetic field with an in-plane magnetization configuration in magnetic-nonmagnetic topological insulator (TI) heterostructures, Cr_{x}(Bi_{1-y}Sb_{y})_{2-x}Te_{3}/(Bi_{1-y}Sb_{y})_{2}Te_{3}, where it is clearly shown that the large second harmonic voltage is governed not by SOT but mainly by asymmetric magnon scattering without macroscopic magnetization oscillation. Thus, this method does not allow an accurate estimation of charge-spin conversion efficiency in TI. Instead, the SOT contribution is exemplified by current pulse induced nonvolatile magnetization switching, which is realized with a current density of 2.5×10^{10}  A m^{-2}, showing its potential as a spintronic material.

Preparation of dilute magnetic semiconductor films by metalorganic chemical vapor deposition

NASA Technical Reports Server (NTRS)

Nouhi, Akbar (Inventor); Stirn, Richard J. (Inventor)

1988-01-01

A method for preparation of a dilute magnetic semiconductor (DMS) film is provided, in which a Group II metal source, a Group VI metal source and a transition metal magnetic ion source are pyrolyzed in the reactor of a metalorganic chemical vapor deposition (MOCVD) system by contact with a heated substrate. As an example, the preparation of films of Cd(sub 1-x)Mn(sub x)Te, in which 0 is less than or equal to x less than or equal to 0.7, on suitable substrates (e.g., GaAs) is described. As a source of manganese, tricarbonyl (methylcyclopentadienyl) manganese (TCPMn) is employed. To prevent TCPMn condensation during its introduction into the reactor, the gas lines, valves and reactor tubes are heated. A thin-film solar cell of n-i-p structure, in which the i-type layer comprises a DMS, is also described; the i-type layer is suitably prepared by MOCVD.

Binary Inspiral in Quadratic Gravity

NASA Astrophysics Data System (ADS)

Yagi, Kent

2015-01-01

Quadratic gravity is a general class of quantum-gravity-inspired theories, where the Einstein-Hilbert action is extended through the addition of all terms quadratic in the curvature tensor coupled to a scalar field. In this article, we focus on the scalar Gauss- Bonnet (sGB) theory and consider the black hole binary inspiral in this theory. By applying the post-Newtonian (PN) formalism, we found that there is a scalar dipole radiation which leads to -1PN correction in the energy flux relative to gravitational radiation in general relativity. From the orbital decay rate of a low-mass X-ray binary A0600-20, we obtain the bound that is six orders of magnitude stronger than the current solar system bound. Furthermore, we show that the excess in the orbital decay rate of XTE J1118+480 can be explained by the scalar radiation in sGB theory.

Rapid variability as a probe of warped space-time around accreting black holes

NASA Astrophysics Data System (ADS)

Axelsson, Magnus

2016-07-01

The geometry of the inner accretion flow of X-ray binaries is complex, with multiple regions contributing to the observed emission. Frequency-resolved spectroscopy is a powerful tool in breaking this spectral degeneracy. We have extracted the spectra of the strong low-frequency quasi-periodic oscillation (QPO) and its harmonic in GX339-4 and XTE J1550-564, and compare these to the time-averaged spectrum and the spectrum of the rapid (<0.1 s) variability. Our results support the picture where the QPO arises from vertical (Lense-Thirring) precession of an inhomogeneous hot flow, softer at larger radii closer to the truncated disc and harder in the innermost parts where the rapid variability is produced. This coupling between variability and spectra allows us to constrain the soft Comptonization component, breaking the degeneracy plaguing the time-averaged spectrum and revealing the geometry of the accretion flow close to the black hole.

Optimization principles for preparation methods and properties of fine ferrite materials

NASA Astrophysics Data System (ADS)

Borisova, N. M.; Golubenko, Z. V.; Kuz'micheva, T. G.; Ol'khovik, L. P.; Shabatin, V. P.

1992-08-01

The paper is devoted to the problems of development of fine materials based on Ba-ferrite for vertical magnetic recording in particular. Taking an analogue — BaFe 12-2 xCo xTe xO 19 — we have optimized the melt co-precipitation method and shown a new opportunity to provide chemical homogeneity of microcrystallites by means of cryotechnology. Magnetic characteristics of the magnetic tape experimental sample for digital video recording are presented. A series of principles of consistent control of ferrite powder properties are formulated and illustrated with specific developments.

A late jet rebrightening revealed from multiwavelength monitoring of the black hole candidate XTE J1752-223

NASA Astrophysics Data System (ADS)

Russell, D. M.; Curran, P. A.; Muñoz-Darias, T.; Lewis, F.; Motta, S.; Stiele, H.; Belloni, T.; Miller-Jones, J. C. A.; Jonker, P. G.; O'Brien, K.; Homan, J.; Casella, P.; Gandhi, P.; Soleri, P.; Markoff, S.; Maitra, D.; Gallo, E.; Cadolle Bel, M.

2012-01-01

We present optical monitoring of the black hole candidate XTE J1752-223 during its 2009-10 outburst and decay to quiescence. The optical light curve can be described by an exponential decay followed by a plateau, then a more rapid fade towards quiescence. The plateau appears to be due to an extra component of optical emission that brightens and then fades over ˜40 days. We show evidence for the origin of this optical 'flare' to be the synchrotron jet during the decaying hard state, and we identify and isolate both disc and jet components in the spectral energy distributions. The optical flare has the same morphology and amplitude as a contemporaneous X-ray rebrightening. This suggests a common origin, but no firm conclusions can be made favouring or disfavouring the jet producing the X-ray flare. The quiescent optical magnitudes are B≥ 20.6, V≥ 21.1, R≥ 19.5, i'≥ 19.2. From the optical outburst amplitude we estimate a likely orbital period of <22 h. We also present near-infrared (NIR) photometry and polarimetry and rare mid-IR imaging (8-12 ?m) when the source is nearing quiescence. The fading jet component, and possibly the companion star, may contribute to the NIR flux. We derive deep mid-IR flux upper limits and NIR linear polarization upper limits. With the inclusion of radio data, we measure an almost flat jet spectral index between radio and optical; Fν∝ν˜+0.05. The data favour the jet break to optically thin emission to reside in the IR, but may shift to frequencies as high as the optical or UV during the peak of the flare. Based on observations collected at the European Southern Observatory, Chile, under ESO Programme ID 086.D-0610, the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias and the Faulkes Telescopes at Haleakala, Maui, USA and Siding Spring, Australia.

Cyclotron resonance and interband optical transitions in HgTe/CdTe(0 1 3) quantum well heterostructures

NASA Astrophysics Data System (ADS)

Ikonnikov, A. V.; Zholudev, M. S.; Spirin, K. E.; Lastovkin, A. A.; Maremyanin, K. V.; Aleshkin, V. Ya; Gavrilenko, V. I.; Drachenko, O.; Helm, M.; Wosnitza, J.; Goiran, M.; Mikhailov, N. N.; Dvoretskii, S. A.; Teppe, F.; Diakonova, N.; Consejo, C.; Chenaud, B.; Knap, W.

2011-12-01

Cyclotron resonance spectra of 2D electrons in HgTe/CdxHg1-xTe (0 1 3) quantum well (QW) heterostructures with inverted band structure have been thoroughly studied in quasiclassical magnetic fields versus the electron concentration varied using the persistent photoconductivity effect. The cyclotron mass is shown to increase with QW width in contrast to QWs with normal band structure. The measured values of cyclotron mass are shown to be systematically less than those calculated using the 8 × 8 Kane model with conventional set of HgTe and CdTe material parameters. In quantizing pulsed magnetic fields (Landau level filling factor less than unity) up to 45 T, both intraband (CR) and interband magnetoabsorption have been studied at radiation wavelengths 14.8 and 11.4 µm for the first time. The results obtained are compared with the allowed transition energies between Landau levels in the valence and conduction bands calculated within the same model, the calculated energies being again systematically less (by 3-14%) than the observed optical transition energies.

Prediction of an arc-tunable Weyl Fermion metallic state in Mo xW 1-xTe 2

DOE PAGES

Chang, Tay-Rong; Xu, Su-Yang; Chang, Guoqing; ...

2016-02-15

A Weyl semimetal is a new state of matter that hosts Weyl fermions as emergent quasiparticles. The Weyl fermions correspond to isolated points of bulk band degeneracy, Weyl nodes, which are connected only through the crystal’s boundary by exotic Fermi arcs. The length of the Fermi arc gives a measure of the topological strength, because the only way to destroy the Weyl nodes is to annihilate them in pairs in the reciprocal space. To date, Weyl semimetals are only realized in the TaAs class. Here, we propose a tunable Weyl state in Mo xW 1₋xTe 2 where Weyl nodes aremore » formed by touching points between metallic pockets. We show that the Fermi arc length can be changed as a function of Mo concentration, thus tuning the topological strength. Lastly,our results provide an experimentally feasible route to realizing Weyl physics in the layered compound Mo xW 1₋xTe 2, where non-saturating magneto-resistance and pressure-driven superconductivity have been observed.« less

Fracture behavior of single-structure fiber-reinforced composite restorations

PubMed Central

Nagata, Kohji; Garoushi, Sufyan K.; Vallittu, Pekka K.; Wakabayashi, Noriyuki; Takahashi, Hidekazu; Lassila, Lippo V. J.

2016-01-01

Abstract Objective: The applications of single-structure fiber-reinforced composite (FRC) in restorative dentistry have not been well reported. This study aimed to clarify the static mechanical properties of anterior crown restorations prepared using two types of single-structure FRC. Materials and methods : An experimental crown restoration was designed for an upper anterior incisor. The restorations were made from IPS Empress CAD for CEREC (Emp), IPS e.max® CAD (eMx), experimental single-structure all-FRC (a-FRC), Filtek™ Supreme XTE (XTE), and commercially available single-structure short-FRC (everX Posterior™) (n = 8 for each material) (s-FRC). The a-FRC restorations were prepared from an experimental FRC blank using a computer-aided design and manufacturing (CAD/CAM) device. A fracture test was performed to assess the fracture load, toughness, and failure mode. The fracture loads were vertically applied on the restorations. The surface micromorphology of the FRC restorations was observed by scanning electron microscopy (SEM). The data were analyzed by analysis of variance (p = .05) followed by Tukey's test. Results : s-FRC showed the highest mean fracture load (1145.0 ± 89.6 N) and toughness (26.2 ± 5.8 Ncm) among all the groups tested. With regard to the micromorphology of the prosthetic surface, local crushing of the fiberglass was observed in s-FRC, whereas chopped fiberglass was observed in a-FRC. Conclusions : The restorations made of short-FRC showed a higher load-bearing capacity than those made of the experimental all-FRC blanks for CAD/CAM. The brittle-like fractures were exhibited in the recent dental esthetic materials, while local crushing fractures were shown for single-structure FRC restorations. PMID:28642921

Energy scaling of the "heartbeat" pulse width of GRS 1915+105, IGR J17091-3624, and MXB 1730-335 from Rossi-XTE observations

NASA Astrophysics Data System (ADS)

Maselli, A.; Capitanio, F.; Feroci, M.; Massa, F.; Massaro, E.; Mineo, T.

2018-04-01

We investigate some key aspects of the "heartbeat" variability consisting of series of bursts with a slow rise and a fast decay, thus far detected only in GRS 1915+105, IGR J17091-3624, and MXB 1730-335. A previous analysis based on BeppoSAX data of GRS 1915+105 revealed a hard-X delay (HXD), that is a lag of the burst rise at higher energies with respect to lower ones; this leads to narrower pulse widths, w, at higher energies. We here use some light curves of Rossi-XTE observations of GRS 1915+105 for a deeper analysis of this effect and search for its presence in those extracted from some IGR J17091-3624 and MXB 1730-335 observations performed with the same satellite. Our results show that, at variance with GRS 1915+105, no HXD is evident in the light curves of MXB 1730-335 and only a marginal HXD may be argued for IGR J17091-3624. For GRS 1915+105 we find a decreasing trend of the pulse width with energy following a power law w = A ṡ E-s with an index s ≈ 0.8. Furthermore, we confirm the increase of the HXD with the recurrence time Trec of the bursts in each series that was already found in previous works using BeppoSAX data. Based on a spectral analysis of these three sources we conclude that the differences highlighted in the properties of the "heartbeat" variability are probably related to the different accreting compact object and the eventual presence of a corona in these binary interacting systems.

Vortex pinning properties in Fe-chalcogenides

NASA Astrophysics Data System (ADS)

Leo, A.; Grimaldi, G.; Guarino, A.; Avitabile, F.; Nigro, A.; Galluzzi, A.; Mancusi, D.; Polichetti, M.; Pace, S.; Buchkov, K.; Nazarova, E.; Kawale, S.; Bellingeri, E.; Ferdeghini, C.

2015-12-01

Among the families of iron-based superconductors, the 11-family is one of the most attractive for high field applications at low temperatures. Optimization of the fabrication processes for bulk, crystalline and/or thin film samples is the first step in producing wires and/or tapes for practical high power conductors. Here we present the results of a comparative study of pinning properties in iron-chalcogenides, investigating the flux pinning mechanisms in optimized Fe(Se{}1-xTe x ) and FeSe samples by current-voltage characterization, magneto-resistance and magnetization measurements. In particular, from Arrhenius plots in magnetic fields up to 9 T, the activation energy is derived as a function of the magnetic field, {U}0(H), whereas the activation energy as a function of temperature, U(T), is derived from relaxation magnetization curves. The high pinning energies, high upper critical field versus temperature slopes near critical temperatures, and highly isotropic pinning properties make iron-chalcogenide superconductors a technological material which could be a real competitor to cuprate high temperature superconductors for high field applications.

A low-temperature study of manganese-induced ferromagnetism and valence band convergence in tin telluride

DOE PAGES

Chi, Hang; Tan, Gangjian; Kanatzidis, Mercouri G.; ...

2016-05-02

In this study, SnTe is renowned for its promise in advancing energy-related technologies based on thermoelectricity and for its topological crystalline insulator character. Here, we demonstrate that each Mn atom introduces ~4 μ B (Bohr magneton) of magnetic moment to Sn 1–xMn xTe. The Curie temperatureTC reaches ~14K for x = 0.12, as observed in the field dependent hysteresis of magnetization and the anomalous Hall effect. In accordance with a modified two-band electronic Kane model, the light L-valence-band and the heavy Σ-valence-band gradually converge in energy with increasing Mn concentration, leading to a decreasing ordinary Hall coefficient R H andmore » a favorably enhanced Seebeck coefficient S at the same time. With the thermal conductivityκ lowered chiefly via point defects associated with the incorporation of Mn, the strategy of Mn doping also bodes well for efficient thermoelectric applications at elevated temperatures.« less

Shocks in the relativistic transonic accretion with low angular momentum

NASA Astrophysics Data System (ADS)

Suková, P.; Charzyński, S.; Janiuk, A.

2017-12-01

We perform 1D/2D/3D relativistic hydrodynamical simulations of accretion flows with low angular momentum, filling the gap between spherically symmetric Bondi accretion and disc-like accretion flows. Scenarios with different directional distributions of angular momentum of falling matter and varying values of key parameters such as spin of central black hole, energy and angular momentum of matter are considered. In some of the scenarios the shock front is formed. We identify ranges of parameters for which the shock after formation moves towards or outwards the central black hole or the long-lasting oscillating shock is observed. The frequencies of oscillations of shock positions which can cause flaring in mass accretion rate are extracted. The results are scalable with mass of central black hole and can be compared to the quasi-periodic oscillations of selected microquasars (such as GRS 1915+105, XTE J1550-564 or IGR J17091-3624), as well as to the supermassive black holes in the centres of weakly active galaxies, such as Sgr A*.

Degradation mechanisms of gamma irradiated LWIR HgCdTe photovoltaic detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarusi, G.; Eger, D.; Zemel, A.

1990-12-01

Planar n{sup +}p Hg{sub 1{minus}x}Cd{sub x}Te (x = 0.23) photodiodes passivated with ZnS were irradiated by Co{sup 60} gamma source. A strong increase in the reverse dark current was observed for doses above 0.3 Mrad(air). A similar effect was found by exposing the photodiodes to U.V illumination from a high pressure mercury lamp. By filtering the U.V light it is shown that the degradation in the performance of the photodiodes is caused by the light or radiation absorbed in the ZnS layer above the implanted n-type region. C-V measurements of irradiated MIS devices showed a significant increase in the fastmore » surface state density. Galvanomagnetic and lifetime measurements made on irradiated p-type HgCdTe layer showed no significant changes in the bulk transport parameters. Based on these findings, a model for the degradation mechanism is proposed.« less

Absence of Local Fluctuating Dimers in Superconducting Ir 1-x(Pt,Rh) xTe 2

DOE PAGES

Yu, Runze; Banerjee, S.; Lei, H. C.; ...

2018-06-01

The compound IrTe2 is known to exhibit a transition to a modulated state featuring Ir-Ir dimers, with large associated atomic displacements. Partial substitution of Pt or Rh for Ir destabilizes the modulated structure and induces superconductivity. It has been proposed that quantum critical dimer fluctuations might be associated with the superconductivity. Here we test for such local dimer correlations and demonstrate their absence. X-ray pair distribution function approach reveals that the local structure of Ir 0.95Pt 0.05Te 2 and Ir 0.8Rh 0.2Te 2 dichalcogenide superconductors with compositions just past the dimer/superconductor boundary is explained well by a dimer-free model downmore » to 10 K, ruling out the possibility of there being nanoscale dimer fluctuations in this regime. This is inconsistent with the proposed quantum-critical-point-like interplay of the dimer state and superconductivity, and precludes scenarios for dimer fluctuations mediated superconducting pairing.« less

Absence of Local Fluctuating Dimers in Superconducting Ir 1-x(Pt,Rh) xTe 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Runze; Banerjee, S.; Lei, H. C.

The compound IrTe2 is known to exhibit a transition to a modulated state featuring Ir-Ir dimers, with large associated atomic displacements. Partial substitution of Pt or Rh for Ir destabilizes the modulated structure and induces superconductivity. It has been proposed that quantum critical dimer fluctuations might be associated with the superconductivity. Here we test for such local dimer correlations and demonstrate their absence. X-ray pair distribution function approach reveals that the local structure of Ir 0.95Pt 0.05Te 2 and Ir 0.8Rh 0.2Te 2 dichalcogenide superconductors with compositions just past the dimer/superconductor boundary is explained well by a dimer-free model downmore » to 10 K, ruling out the possibility of there being nanoscale dimer fluctuations in this regime. This is inconsistent with the proposed quantum-critical-point-like interplay of the dimer state and superconductivity, and precludes scenarios for dimer fluctuations mediated superconducting pairing.« less

Absence of local fluctuating dimers in superconducting Ir1 -x(Pt,Rh ) xTe2

NASA Astrophysics Data System (ADS)

Yu, Runze; Banerjee, S.; Lei, H. C.; Sinclair, Ryan; Abeykoon, M.; Zhou, H. D.; Petrovic, C.; Guguchia, Z.; Bozin, E. S.

2018-05-01

The compound IrTe2 is known to exhibit a transition to a modulated state featuring Ir-Ir dimers, with large associated atomic displacements. Partial substitution of Pt or Rh for Ir destabilizes the modulated structure and induces superconductivity. It has been proposed that quantum critical dimer fluctuations might be associated with the superconductivity. Here we test for such local dimer correlations and demonstrate their absence. X-ray pair distribution function approach reveals that the local structure of Ir0 :95Pt0 :05Te2 and Ir0 :8Rh0 :2Te2 dichalcogenide superconductors with compositions just past the dimer/superconductor boundary is explained well by a dimer-free model down to 10 K, ruling out the possibility of there being nanoscale dimer fluctuations in this regime. This is inconsistent with the proposed quantum-critical-point-like interplay of the dimer state and superconductivity, and precludes scenarios for dimer fluctuations mediated superconducting pairing.

Electrical properties of Pb{sub 1-x}Mn{sub x}Te single crystals with an excess of tellurium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bagieva, G. Z., E-mail: bagieva-gjulandam@rambler.ru; Abdinova, G. D.; Mustafayev, N. B.

2013-03-15

The effect of excess Te atoms (as high as 0.5 at %) and thermal treatment at 473 K for 120 h on the electrical conductivity {sigma}, the thermopower coefficient {alpha}, and the Hall coefficient R of Pb{sub 0.96}Mn{sub 0.04}Te single crystals in the temperature range {approx}77-300 K is investigated. It is shown that excess atoms of tellurium predominantly act as acceptor impurity centers at low concentrations in unannealed samples and form antisite defects at relatively high concentrations (0.05 at % or higher) being located mainly in vacancies of the lead sublattice, and decrease the hole concentration. As a result ofmore » annealing, certain lattice defects (for example, deformational) are healed, and the accommodation process for Te atoms at lead-sublattice vacancies is intensified. These processes substantially affect the values of the electrical parameters, their temperature dependences, as well as the sign of the thermopower and Hall coefficients of the samples.« less

X-Ray Continua of Broad Absorption Line Quasars

NASA Technical Reports Server (NTRS)

Mathur, S.

1999-01-01

The targets for this program, PG1416-129 and LBQS 2212-1759 were known to be Broad Absorption Line Quasars (BALQSOs). BALQSOs are highly absorbed in soft X-rays. Good high energy response of Rossi-XTE made them ideal targets for observation. We observed LBQS 2212-1759 with PCA. We have now analyzed the data and found that the source was not detected. Since our target was expected to be faint, reliable estimate of background was very important. With the release of new FTOOLS (version 4.1) we were able to do so. We also analyzed a well known bright object and verified our results with the published data. This gave us confidence in the non-detection of our target LBQS 2212-1759. We are currently investigating the implications of this non-detection. Due to some scheduling problems, our second target PG1416-129 was not observed in A01. It was observed on 06/26/98. This target was detected with RXTE. We are now working on the spectral analysis with XSPEC.

Can percolation control doping, diffusion and phase segregation in (Hg,Cd)Te?

NASA Astrophysics Data System (ADS)

Cahen, David; Melamed, Ofer; Lubomirski, Igor

1999-02-01

We show that percolation can control not only diffusion in solids, but in the case of semiconductors also their electrical activity, via the doping action of the diffusing species. This occurs in (Hg 1- xCd x)Te (MCT) when xCd<0.8. The 10 7 times higher diffusivity at xCd<0.8 can be understood by realizing that the percolation threshold for an ideal FCC lattice is at 0.19. While normally Ag is a donor, it can be an acceptor by stabilizing the Hg(I) state. This is possible by interaction with 2 Hg neighbors, a process that will be favorable above the Hg percolation limit. The fast Ag diffusion also holds the clue for the occurrence of ultra-low concentration phase separation in this system, the result of a balance between elastic attraction and Coulombic repulsion between the charged dopants. Prima facie evidence for this phase separation comes from coulometric Ag titration in and out of MCT.

X-Ray Observations of High-Energy Pulsars: PSR B1951+32 and Geminga

NASA Astrophysics Data System (ADS)

Ho, Cheng

Observations at frequencies across a wide range of electromagnetic spectra are key to the understanding of the origin and mechanisms of high-energy emissions from pulsars. We propose to observe the high-energy pulsars PSR B1951+32 and Geminga with XTE. These two sources emit X-rays at low enough count rate that we can acquire high resolution timing and spectral data, allowing us to perform detailed analysis on the ground. Staring integration of 10 ksec for each source is requested. Data obtained in these observations, together with those from ROSAT, GRO and a planned project for optical counterpart study at Los Alamos, will provide crucial information to advance high-energy pulsar research.

X-ray Reverberation Mapping of Ci Cam

NASA Astrophysics Data System (ADS)

Bartlett, Elizabeth; Garcia, M.

2009-01-01

We have analyzed the X-ray lightcurve of the star CI Cam, the optical counterpart of the X-ray transient XTE J0421+56 using data from XMM-Newton. Our motivation is based on evidence from ground based optical interferometry from the Keck and IOTA observatories which suggests that the dust surrounding CI CAM has a taurus morphology rather than a spherical distribution as previously hypothesized. By using a technique known as reverberation mapping we have constrained the time delay between the continuum of CI Cam and the Fe-K fluorescence line, corresponding to the reflection of the continuum off the dusty taurus. The time delay yields information on the size of the taurus.

An Integral Study of Galactic Black Hole States

NASA Technical Reports Server (NTRS)

2005-01-01

XTE 51550-564 was clearly detected with INTEGRAL out to 600 keV with the SPI, and is one of only two sources detected with IBISPICSIT. Software difficulties in analyzing the data prevented us from progressing with the analysis past the most elementary stages (see last year's report). The support from the INTEGRAL help desk has been very disappointing. People affiliated with INTEGRAL published a paper on the results of our data before we could master the reduction and analysis software. We are not the only group that got stuck with the analysis without adequate support from the INTEGRAL help desk. This was a rather disappointing experience as we lost many months of valuable time and efforts.

LL13-MatModelRadDetect-PD2Jf Final Report: Materials Modeling for High-Performance Radiation Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lordi, Vincenzo

The aims of this project are to enable rational materials design for select high-payoff challenges in radiation detection materials by using state-of-the-art predictive atomistic modeling techniques. Three specific high-impact challenges are addressed: (i) design and optimization of electrical contact stacks for TlBr detectors to stabilize temporal response at room-temperature; (ii) identification of chemical design principles of host glass materials for large-volume, low-cost, highperformance glass scintillators; and (iii) determination of the electrical impacts of dislocation networks in Cd 1-xZn xTe (CZT) that limit its performance and usable single-crystal volume. The specific goals are to establish design and process strategies to achievemore » improved materials for high performance detectors. Each of the major tasks is discussed below in three sections, which include the goals for the task and a summary of the major results, followed by a listing of publications that contain the full details, including details of the methodologies used. The appendix lists 12 conference presentations given for this project, including 1 invited talk and 1 invited poster.« less

AN IMPROVED DYNAMICAL MODEL FOR THE MICROQUASAR XTE J1550-564

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orosz, Jerome A.; Steiner, James F.; McClintock, Jeffrey E.

2011-04-01

We present an improved dynamical model of the X-ray binary and microquasar XTE J1550-564 based on new moderate-resolution optical spectroscopy and near-infrared photometry obtained with the 6.5 m Magellan Telescopes at Las Campanas Observatory. Twelve spectra of the source were obtained using the Magellan Echellette Spectrograph between 2008 May 6 and August 4. In addition, several hundred images of the field were obtained between 2006 May and 2009 July in the J and K{sub S} filters using the PANIC camera. The agreement between the 2006/2007 and 2008 J and K{sub S} light curves is not perfect, and the differences canmore » plausibly be attributed to a hot spot on the accretion disk during the 2006/2007 observations. By combining our new radial velocity measurements with previous measurements obtained in 2001 May at the 8.2 m Very Large Telescope and with light curves, we find an orbital period of P = 1.5420333 {+-} 0.0000024 days and a radial velocity semiamplitude of K{sub 2} = 363.14 {+-} 5.97 km s{sup -1}, which together imply an optical mass function of f(M) = 7.65 {+-} 0.38 M{sub sun}. We find that the projected rotational velocity of the secondary star is 55 {+-} 5 km s{sup -1}, which implies a very extreme mass ratio of Q {identical_to} M/M{sub 2} {approx} 30. Using a model of a Roche lobe-filling star and an azimuthally symmetric accretion disk, we fit simultaneously optical light curves from 2001, near-infrared light curves from 2008, and all of the radial velocity measurements to derive system parameters. We find an inclination of 74.{sup 0}7 {+-} 3.{sup 0}8 and component masses of M{sub 2} = 0.30 {+-} 0.07 M{sub sun} and M = 9.10 {+-} 0.61 M{sub sun} for the secondary star and black hole, respectively. We note that these results depend on the assumption that in 2008, the disk did not have a hot spot, and that the fraction of light contributed by the accretion disk did not change between the spectroscopic and photometric observations. By considering two measured values of the disk fraction and by modeling various combinations of NIR and optical light curves, we show that our adopted black hole mass is probably not seriously in error, where the black hole mass ranges between M = 8.91 {+-} 1.10 M{sub sun} and M = 13.94 {+-} 1.64 M{sub sun}. The radius of the secondary star for the adopted model is 1.75 {+-} 0.12 R{sub sun}. Using this radius, the average K{sub S} magnitude, and an extinction of A{sub K} = 0.507 {+-} 0.050 mag, we find a distance of 4.38{sup +0.58}{sub -0.41} kpc, which is in good agreement with a recent distance estimate based on H I absorption lines.« less

Repairability of CAD/CAM high-density PMMA- and composite-based polymers.

PubMed

Wiegand, Annette; Stucki, Lukas; Hoffmann, Robin; Attin, Thomas; Stawarczyk, Bogna

2015-11-01

The study aimed to analyse the shear bond strength of computer-aided design and computer-aided manufacturing (CAD/CAM) polymethyl methacrylate (PMMA)- and composite-based polymer materials repaired with a conventional methacrylate-based composite after different surface pretreatments. Each 48 specimens was prepared from six different CAD/CAM polymer materials (Ambarino high-class, artBloc Temp, CAD-Temp, Lava Ultimate, Telio CAD, Everest C-Temp) and a conventional dimethacrylate-based composite (Filtek Supreme XTE, control) and aged by thermal cycling (5000 cycles, 5-55 °C). The surfaces were left untreated or were pretreated by mechanical roughening, aluminium oxide air abrasion or silica coating/silanization (each subgroup n = 12). The surfaces were further conditioned with an etch&rinse adhesive (OptiBond FL) before the repair composite (Filtek Supreme XTE) was adhered to the surface. After further thermal cycling, shear bond strength was tested, and failure modes were assessed. Shear bond strength was statistically analysed by two- and one-way ANOVAs and Weibull statistics, failure mode by chi(2) test (p ≤ 0.05). Shear bond strength was highest for silica coating/silanization > aluminium oxide air abrasion = mechanical roughening > no surface pretreatment. Independently of the repair pretreatment, highest bond strength values were observed in the control group and for the composite-based Everest C-Temp and Ambarino high-class, while PMMA-based materials (artBloc Temp, CAD-Temp and Telio CAD) presented significantly lowest values. For all materials, repair without any surface pretreatment resulted in adhesive failures only, which mostly were reduced when surface pretreatment was performed. Repair of CAD/CAM high-density polymers requires surface pretreatment prior to adhesive and composite application. However, four out of six of the tested CAD/CAM materials did not achieve the repair bond strength of a conventional dimethacrylate-based composite. Repair of PMMA- and composite-based polymers can be achieved by surface pretreatment followed by application of an adhesive and a conventional methacrylate-based composite.

Enough Is Enough

NASA Technical Reports Server (NTRS)

Barrowman, James

2003-01-01

The spacecraft was nearly integrated and had passed some of its early mechanical and electrical testing. One of its instruments, the Proportional Counter Array (PCA), had a gas leak in one of the five proportional counter modules that made up the array. The science division where the instrument was being developed wanted a gas replenishment system added to assure the PCA would last for the entire mission. Adding a gas replenishment system would mean interrupting spacecraft integration and testing; developing a new subsystem and integrating it onto the spacecraft; modifying all the PCA modules; including a complex integration of the instrument onto the spacecraft; and implementing a more complex performance and environmental test process. It was the wrong answer because it made a simple design more complex and added little value to the mission at a major cost in time and dollars. Our mission couldn't afford the additional budget and schedule risks. XTE was the latest of a long line of projects being managed by my Explorer Program Office, but it was unique in being the first project we had agreed to do for a fixed price. NASA HQ agreed, in return, to provide us with the funding profile we needed to make it happen. We were both trying to break the unhealthy spiral in the Explorer program that saw current missions overrunning and pushing subsequent missions downstream to the point where their science was becoming marginal. The science community was upset and wanted better performance from NASA. I summarized my arguments to the director. The Engineering Directorate had taken responsibility for the spacecraft development when we established XTE as an in-house project at Goddard Space Flight Center, and also was supporting the PCA development. "It adds complexity," I reiterated. "It's a significant cost impact for only a marginal reliability increase". His response was music to my ears, "Jim, I won't stand in your way, but you'll have to convince the scientists and engineers."

Relativistic Astrophysics in Black Hole and Low-Mass Neutron Star Binaries LTSA98

NASA Technical Reports Server (NTRS)

Cui, Wei

2000-01-01

My group, in close collaboration with Dr. Zhang's group at University of Alabama-Huntsville, have been systematically analyzing and re-analyzing a substantial amount of archival data from previous and ongoing X-ray missions, in order to study possible relativistic effects around stellar-mass black holes and neutron stars. Our effort has been focused primarily on the data from the Rossi X-ray Timing Explorer. We carefully studied interesting quasi-periodic X-ray variability in newly discovered black hole candidates (XTE J1859+226 and XTE J1550-564), which, as we had proposed earlier, could be caused by general relativistic process (e.g., frame dragging) around the central black hole. We also discovered an intriguing temporal correlation between X-ray photons at different energies that is associated with the quasi-periodic signals of interest. The results provided new insights into the physical origin of the phenomena. Furthermore, we studied the spectral lines of black hole candidates which provide another avenue for studying general relativistic processes around black holes. The lines-may originate in the relativistic jets (which could be powered by the spin of the black hole) or in the disk around the black hole, as in the cases of 4U 1630-47 and GX 339-4 (two well-known black hole candidates), and may thus be distorted or shifted due to relativistic effects. Of course, neutron star systems were not forgotten either. After examining the properties of newly discovered fast quasi-periodic variability (at kiloHertz) associated with such systems, we proposed a relativistic model to explain the origin of the signals. We have also started to use new great observatories in orbit (such as Chandra and XMM-Newton) to observe the sources that are of interest to us. Finally, interesting results were also been obtained from our collaborations with other groups who are interested in some of the same objects. Such collaborative efforts have greatly enhanced the project and will likely continue in the future.

Ionic electrodeposition of II-VI and III-V compounds. III. Computer simulation of quasi-rest potentials for M/sub 1/X/sub 1/ compounds analogous to CdTe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelken, R.D.

1987-04-01

The quasi-rest potential (QRP) has been proposed as a key quantity in characterizing compound semiconductor (e.g. CdTe) electrodeposition. This article expands the modeling/simulation representative of Cd/sub x/Te in chemical equilibrium to calculate two ''QRP's'': E/sub M/1/sub /, the mixed potential occurring immediately after current interruption and before any relaxation in double layer ion concentration and significant ion exchange/surface stoichiometry change occur, and E/sub M/2/sub /, another mixed potential occurring after the double layer ion concentrations have relaxed to their bulk values but still before any significant surface composition change occurs. Significant predictions include existence of a dramatic negative transition inmore » QRP, with negative-going deposition potential, centered on the potential of perfect stoichiometry (PPS), inequality, in general, between the PPS and E/sub M/1/sub / unless the deposit remains in equilibrium with the electrolyte (no ion exchange at open circuit), negligible sensitivity of QRP-E curves to the activity coefficient parameter implying the importance of the PPS in characterizing compound deposition, and disappearance of the transition structure for sufficiently positive Gibbs free energies.« less

Proximity-driven enhanced magnetic order at ferromagnetic-insulator-magnetic-topological-insulator interface

DOE PAGES

Li, Mingda; Zhu, Yimei; Chang, Cui -Zu; ...

2015-08-17

Magnetic exchange driven proximity effect at a magnetic-insulator–topological-insulator (MI-TI) interface provides a rich playground for novel phenomena as well as a way to realize low energy dissipation quantum devices. In this study, we report a dramatic enhancement of proximity exchange coupling in the MI/magnetic-TI EuS/Sb 2–xV xTe 3 hybrid heterostructure, where V doping is used to drive the TI (Sb 2Te 3) magnetic. We observe an artificial antiferromagneticlike structure near the MI-TI interface, which may account for the enhanced proximity coupling. The interplay between the proximity effect and doping in a hybrid heterostructure provides insights into the engineering of magneticmore » ordering.« less

Study of optical nonlinearities in Se-Te-Bi thin films

NASA Astrophysics Data System (ADS)

Sharma, Ambika; Yadav, Preeti; Kumari, Anshu

2014-04-01

The present work reports the nonlinear refractive index of Se85-xTe15Bix thin films calculated by Ticha and Tichy relation. The nonlinear refractive index of Chalcogenide amorphous semiconductor is well correlated with the linear refractive index and WDD parameters which in turn depend on the density and molar volume of the system. The density of the system is calculated theoretical as well as experimentally by using Archimedes principle. The linear refractive index and WDD parameters are calculated using single transmission spectra in the spectral range of 400-1500 nm. It is observed that linear as well as nonlinear refractive index increases with Bi content. The results are analyzed on the basis of increasing polarizability due to larger radii of Bi.

Accreting Millisecond Pulsars: Neutron Star Masses and Radii

NASA Technical Reports Server (NTRS)

Strohmayer, Tod

2004-01-01

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. The recent discovery of X-ray burst oscillations from two accreting millisecond pulsars has confirmed this basic picture and provided a new route to measuring neutron star properties and constraining the dense matter equation of state. I will briefly summarize the current observational understanding of accreting millisecond pulsars, and describe recent attempts to determine the mass and radius of the neutron star in XTE J1814-338.

An X-Ray Survey for Polar CAP Qpos in AM Herculis Systems

NASA Astrophysics Data System (ADS)

Wood, Kent

Five AM Herculis binary systems show an optical QPO that is known to be associated with magentically channeled polar cap accretion. Hard X-ray QPOs are predicted by the time-depndent hydrodynamic models. We propose to search selected AM Her systems for polar cap X-ray QPOs using the XTE PCA. Because of its large collecting area, the PCA is the only instrument that can do this job. No other accreting objects provide comparable high-quality observational diagnostics on the accretion flow. The detailed understanding of flow geometry, shock heating, ion-electron energy exchange, accretion column structure, and emission and radiative transfer mechanisms that go to make up the picture of AM Her accretion needs to be tested against X-ray timing information.

Probing the Optical Properties and Strain-Tuning of Ultrathin Mo1- xW xTe2.

PubMed

Aslan, Ozgur Burak; Datye, Isha M; Mleczko, Michal J; Sze Cheung, Karen; Krylyuk, Sergiy; Bruma, Alina; Kalish, Irina; Davydov, Albert V; Pop, Eric; Heinz, Tony F

2018-04-11

Ultrathin transition metal dichalcogenides (TMDCs) have recently been extensively investigated to understand their electronic and optical properties. Here we study ultrathin Mo 0.91 W 0.09 Te 2 , a semiconducting alloy of MoTe 2 , using Raman, photoluminescence (PL), and optical absorption spectroscopy. Mo 0.91 W 0.09 Te 2 transitions from an indirect to a direct optical band gap in the limit of monolayer thickness, exhibiting an optical gap of 1.10 eV, very close to its MoTe 2 counterpart. We apply tensile strain, for the first time, to monolayer MoTe 2 and Mo 0.91 W 0.09 Te 2 to tune the band structure of these materials; we observe that their optical band gaps decrease by 70 meV at 2.3% uniaxial strain. The spectral widths of the PL peaks decrease with increasing strain, which we attribute to weaker exciton-phonon intervalley scattering. Strained MoTe 2 and Mo 0.91 W 0.09 Te 2 extend the range of band gaps of TMDC monolayers further into the near-infrared, an important attribute for potential applications in optoelectronics.

Probing the Optical Properties and Strain-Tuning of Ultrathin Mo 1–xW xTe 2

DOE PAGES

Aslan, Ozgur Burak; Datye, Isha M.; Mleczko, Michal J.; ...

2018-03-21

Ultrathin transition metal dichalcogenides (TMDCs) have recently been extensively investigated to understand their electronic and optical properties. Here we study ultrathin Mo 0.91W 0.09Te 2, a semiconducting alloy of MoTe 2, using Raman, photoluminescence (PL), and optical absorption spectroscopy. Mo 0.91W 0.09Te 2 transitions from an indirect to a direct optical band gap in the limit of monolayer thickness, exhibiting an optical gap of 1.10 eV, very close to its MoTe 2 counterpart. We apply tensile strain, for the first time, to monolayer MoTe 2 and Mo 0.91W 0.09Te 2 to tune the band structure of these materials; we observemore » that their optical band gaps decrease by 70 meV at 2.3% uniaxial strain. The spectral widths of the PL peaks decrease with increasing strain, which we attribute to weaker exciton–phonon intervalley scattering. Furthermore, strained MoTe 2 and Mo 0.91W 0.09Te 2 extend the range of band gaps of TMDC monolayers further into the near-infrared, an important attribute for potential applications in optoelectronics.« less

Probing the Optical Properties and Strain-Tuning of Ultrathin Mo 1–xW xTe 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aslan, Ozgur Burak; Datye, Isha M.; Mleczko, Michal J.

Ultrathin transition metal dichalcogenides (TMDCs) have recently been extensively investigated to understand their electronic and optical properties. Here we study ultrathin Mo 0.91W 0.09Te 2, a semiconducting alloy of MoTe 2, using Raman, photoluminescence (PL), and optical absorption spectroscopy. Mo 0.91W 0.09Te 2 transitions from an indirect to a direct optical band gap in the limit of monolayer thickness, exhibiting an optical gap of 1.10 eV, very close to its MoTe 2 counterpart. We apply tensile strain, for the first time, to monolayer MoTe 2 and Mo 0.91W 0.09Te 2 to tune the band structure of these materials; we observemore » that their optical band gaps decrease by 70 meV at 2.3% uniaxial strain. The spectral widths of the PL peaks decrease with increasing strain, which we attribute to weaker exciton–phonon intervalley scattering. Furthermore, strained MoTe 2 and Mo 0.91W 0.09Te 2 extend the range of band gaps of TMDC monolayers further into the near-infrared, an important attribute for potential applications in optoelectronics.« less

Temperature Dependences of the Product of the Differential Resistance by the Area in MIS-Structures Based on Cd x Hg1- x Te Grown by Molecularbeam Epitaxy on Alternative Si and GaAs Substrates

NASA Astrophysics Data System (ADS)

Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.; Varavin, V. S.; Vasil'ev, V. V.; Dvoretskii, S. A.; Mikhailov, N. N.; Yakushev, M. V.; Sidorov, G. Yu.

2017-06-01

In a temperature range of 9-200 K, temperature dependences of the differential resistance of space-charge region in the strong inversion mode are experimentally studied for MIS structures based on CdxHg1-xTe (x = 0.22-0.40) grown by molecular-beam epitaxy. The effect of various parameters of structures: the working layer composition, the type of a substrate, the type of insulator coating, and the presence of a near-surface graded-gap layer on the value of the product of differential resistance by the area is studied. It is shown that the values of the product RSCRA for MIS structures based on n-CdHgTe grown on a Si(013) substrate are smaller than those for structures based on the material grown on a GaAs(013) substrate. The values of the product RSCRA for MIS structures based on p-CdHgTe grown on a Si(013) substrate are comparable with the value of the analogous parameter for MIS structures based on p-CdHgTe grown on a GaAs(013) substrate.

The UCSD high energy X-ray timing experiment cosmic ray particle anticoincidence detector

NASA Technical Reports Server (NTRS)

Hink, P. L.; Rothschild, R. E.; Pelling, M. R.; Macdonald, D. R.; Gruber, D. E.

1991-01-01

The HEXTE, part of the X-Ray Timing Explorer (XTE), is designed to make high sensitivity temporal and spectral measurements of X-rays with energies between 15 and 250 keV using NaI/CsI phoswich scintillation counters. To achieve the required sensitivity it is necessary to provide anticoincidence of charged cosmic ray particles incident upon the instrument, some of which interact to produce background X-rays. The proposed cosmic ray particle anticoincidence shield detector for HEXTE uses a novel design based on plastic scintillators and wavelength-shifter bars. It consists of five segments, each with a 7 mm thick plastic scintillator, roughly 50 cm x 50 cm in size, coupled to two wavelength-shifter bars viewed by 1/2 inch photomultiplier tubes. These segments are configured into a five-sided, box-like structure around the main detector system. Results of laboratory testing of a model segment, and calculations of the expected performance of the flight segments and particle anticoincidence detector system are presented to demonstrate that the above anticoincidence detector system satisfies its scientific requirements.

Revealing the inner accretion flow around black holes using rapid variability

NASA Astrophysics Data System (ADS)

Axelsson, Magnus

2015-08-01

The geometry of the inner accretion flow of X-ray binaries is complex, with multiple regions contributing to the observed emission. Frequency-resolved spectroscopy is a powerful tool in breaking this spectral degeneracy. We have extracted the spectra of the strong low-frequency quasi-periodic oscillation (QPO) and its harmonic in GX339-4 and XTE J1550-564. We compare these to the time-averaged spectrum and the spectrum of the rapid (< 0.1s) variability. Our results support the picture where the QPO arises from vertical (Lense-Thirring) precession of an inhomogeneous hot flow, so that it is softer at larger radii closer to the truncated disc, and harder in the innermost parts of the flow where the rapid variability is produced. This coupling between variability and spectra allows us to constrain the soft Comptonization component, breaking the degeneracy plaguing the time-averaged spectrum and revealing the geometry of the accretion flow close to the black hole. We further show how the upcoming launch of ASTRO-H will allow even more specific regions in the accretion flow to be probed.

Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars

NASA Astrophysics Data System (ADS)

Kotrlová, Andrea; Török, Gabriel; Šrámková, Eva; Stuchlík, Zdeněk

2014-12-01

We have previously applied several models of high-frequency quasi-periodic oscillations (HF QPOs) to estimate the spin of the central Kerr black hole in the three Galactic microquasars, GRS 1915+105, GRO J1655-40, and XTE J1550-564. Here we explore the alternative possibility that the central compact body is a super-spinning object (or a naked singularity) with the external space-time described by Kerr geometry with a dimensionless spin parameter a ≡ cJ/GM2> 1. We calculate the relevant spin intervals for a subset of HF QPO models considered in the previous study. Our analysis indicates that for all but one of the considered models there exists at least one interval of a> 1 that is compatible with constraints given by the ranges of the central compact object mass independently estimated for the three sources. For most of the models, the inferred values of a are several times higher than the extreme Kerr black hole value a = 1. These values may be too high since the spin of superspinars is often assumed to rapidly decrease due to accretion when a ≫ 1. In this context, we conclude that only the epicyclic and the Keplerian resonance model provides estimates that are compatible with the expectation of just a small deviation from a = 1.

Implication of the Observable Spectral Cutoff Energy Evolution in XTE J1550-564

NASA Technical Reports Server (NTRS)

Titarchuk, Lev; Shaposhnikov, Nikolai

2010-01-01

The physical mechanisms responsible for production of the non-thermal emission in accreting black holes should be imprinted in the observational appearances of the power law tails in the X-ray spectra from these objects. Variety of spectral states observed from galactic black hole binaries by it Rossi X-ray Timing Explorer (RXTE) allow examination of the photon upscattering under different accretion regimes. We revisit of RXTE data collected from the black hole X-ray binary XTE J1550-564 during two periods of X-ray activity in 1998 and 2000 focusing on the behavior of the high energy cutoff of the power law part of the spectrum. For the 1998 outburst the Iran- sition from the low-hard state to the intermediate state was accompanied by a gradual decrease in the cutoff energy which then showed a sharp reversal to a clear increasing trend during the further evolution towards the very high and high-soft states. However, the 2000 outburst showed only the decreasing part of this pattern. Notably, the photon indexes corresponding to the cutoff increase for the 1998 event are much higher than the index values reached during the 2000 rise transition. We attribute this difference in the cutoff' energy behav- for to the different partial contributions of the thermal and non-thermal (bulk motion) Comptonization in photon upscattering. Namely, during the 1998 event the higher accretion rate presumably provided more cooling to the Comptonizing media and thus reducing the effectiveness of the thermal upscattering process. Under these conditions the bulk motion takes a leading role in boosting the input soft photons. Monte Carlo simulations of the The physical mechanisms responsible for production of the non-thermal emission in accreting black holes should be imprinted in the observational apperances of the power law tails in the X-ray spectra from these objects. Variety of spectral states observed from galactic black hole binaries by it Rossi X-ray Timing Explorer (RXTE) allow examination of the photon upscattering under different accretion regimes. We revisit of RXTE data collected from the black hole X-ray binary XTE J1550-564 during two periods of X-ray activity in 1998 and 2000 focusing on the behavior of the high energy cutoff of the power law part of the spectrum. For the 1998 outburst the Iran- sition from the low-hard state to the intermediate state was accompanied by a gradual decrease in the cutoff energy which then showed a sharp reversal to a clear increasing trend during the further evolution towards the very high and high-soft states. However, the 2000 outburst showed only the decreasing part of this pattern. Notably, the photon indexes corresponding to the cutoff increase for the 1998 event are much higher than the index values reached during the 2000 rise transition. We attribute this difference in the cutoff' energy behav- for to the different partial contributions of the thermal and non-thermal (bulk motion) Comptonization in photon upscattering. Namely, during the 1998 event the higher accretion rate presumably provided more cooling to the Comptonizing media and thus reducing the effectiveness of the thermal upscattering process. Under these conditions the bulk motion takes a leading role in boosting the input soft photons. Monte Carlo simulations of the Comptonization in a bulk motion region near an accreting black hole by Laurent & Titarchuk (2010) strongly support this scenario. strongly support this scenario

Luminosity Dependence and Search Doppler

NASA Technical Reports Server (NTRS)

VanParadijs, Johannes A.

1998-01-01

The research supported by this grant covered two projects: (1) a study of the luminosity dependence of the properties of atoll sources; and (2) a search for Doppler shifts in the pulse arrival times of the anomalous pulsar 4U 0142+61. Following the discovery of kilohertz quasi-periodic oscillations (QPOS) in Sco X-1 studies of the X-ray properties of atoll sources have been dominated by searches for these QPOS, and the study of their dependence on other source properties, such as X-ray luminosity and spectral state. In the project supported by grant NAG5-3269 we have detected kHz QPOs for several atoll sources. The physical interpretation of these QPO is as yet unclear, but simple models (such as the Keplerian beat frequency model) can probably be excluded. The results of this research have been reported. We have studied the X-ray pulsations of the anomalous X-ray pulsar 4U 0142+61 using the Rossi XTE. A detailed search for Doppler shifts did not lead to a positive detection. The upper limits exclude almost all types of possible companion stars, except white dwarfs. However, the latter can be excluded since anomalous X-ray pulsars are very young objects. We therefore conclude that anomalous X-ray pulsars are single neutron stars.

Connection Between X-Ray Dips and Superluminal Ejections in the Radio Galaxy 3C 120

NASA Technical Reports Server (NTRS)

Aller, Margo F.

2005-01-01

This work represents a part of a long-term study of the X-ray flux variability of 3C 120 and its relation to flux and structural changes in the radio jet of this galaxy. The grant included fiinding for the rediiction and analysis of data obt,ained during the time pwiod of Rossi XTE cycle 8 (March 1, 2003-February 29, 2004). Prior RXTE observations, combined with single dish monitoring at centimeter wavelengths and 43 GHz mapping (monthly until February 1999 and bimonthly thereafter) of the inner jet with the VLBA, had identified the presence of X-ray dips in the light curves and X-ray spectral hardening 4 weeks prior to the ejection of new VLBI components in the radio jet. This suggested a picture in which the radio jet was fed by accretion events near the black hole. The specific goals of the cycle 8 observations were to better define the relation between the X-ray dips and the radio events using higher sampling, to include more events in the correlation and hence improve the statistics, to look for a possible optical X-ray connection, and to search for quasi periodicities on timescales of 1-3 days. In cycle 8 this project was awarded time for 4 pointings weekly with RXTE.

Impact of extended defects on recombination in CdTe heterostructures grown by molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaunbrecher, Katherine N.; National Renewable Energy Laboratory, Golden, Colorado 80401; Kuciauskas, Darius

Heterostructures with CdTe and CdTe{sub 1-x}Se{sub x} (x ∼ 0.01) absorbers between two wider-band-gap Cd{sub 1-x}Mg{sub x}Te barriers (x ∼ 0.25–0.3) were grown by molecular beam epitaxy to study carrier generation and recombination in bulk materials with passivated interfaces. Using a combination of confocal photoluminescence (PL), time-resolved PL, and low-temperature PL emission spectroscopy, two extended defect types were identified and the impact of these defects on charge-carrier recombination was analyzed. The dominant defects identified by confocal PL were dislocations in samples grown on (211)B CdTe substrates and crystallographic twinning-related defects in samples on (100)-oriented InSb substrates. Low-temperature PL shows that twin-related defects have amore » zero-phonon energy of 1.460 eV and a Huang-Rhys factor of 1.50, while dislocation-dominated samples have a 1.473-eV zero-phonon energy and a Huang-Rhys factor of 1.22. The charge carrier diffusion length near both types of defects is ∼6 μm, suggesting that recombination is limited by diffusion dynamics. For heterostructures with a low concentration of extended defects, the bulk lifetime was determined to be 2.2 μs with an interface recombination velocity of 160 cm/s and an estimated radiative lifetime of 91 μs.« less

The 2:3:6 quasi-periodic oscillation structure in GRS 1915+105 and cubic subharmonics in the context of relativistic discoseismology

NASA Astrophysics Data System (ADS)

Ortega-Rodríguez, M.; Solís-Sánchez, H.; López-Barquero, V.; Matamoros-Alvarado, B.; Venegas-Li, A.

2014-06-01

We propose a simple toy model to explain the 2:3:6 quasi-periodic oscillation (QPO) structure in GRS 1915+105 and, more generally, the 2:3 QPO structure in XTE J1550-564, GRO J1655-40 and H1743-322. The model exploits the onset of subharmonics in the context of discoseismology. We suggest that the observed frequencies may be the consequence of a resonance between a fundamental g mode and an unobservable p wave. The results include the prediction that, as better data become available, a QPO with a frequency of twice the higher twin frequency and a large quality factor will be observed in twin peak sources, as it might already have been observed in the especially active GRS 1915+105.

Promising ferroelectricity in 2D group IV tellurides: a first-principles study

NASA Astrophysics Data System (ADS)

Wan, Wenhui; Liu, Chang; Xiao, Wende; Yao, Yugui

2017-09-01

Based on the first-principles calculations, we investigated the ferroelectric properties of two-dimensional (2D) Group-IV tellurides XTe (X = Si, Ge, and Sn), with a focus on GeTe. 2D Group-IV tellurides energetically prefer an orthorhombic phase with a hinge-like structure and an in-plane spontaneous polarization. The intrinsic Curie temperature Tc of monolayer GeTe is as high as 570 K and can be raised quickly by applying a tensile strain. An out-of-plane electric field can effectively decrease the coercive field for the reversal of polarization, extending its potential for regulating the polarization switching kinetics. Moreover, for bilayer GeTe, the ferroelectric phase is still the ground state. Combined with these advantages, 2D GeTe is a promising candidate material for practical integrated ferroelectric applications.

Space and Earth Sciences, Computer Systems, and Scientific Data Analysis Support, Volume 1

NASA Technical Reports Server (NTRS)

Estes, Ronald H. (Editor)

1993-01-01

This Final Progress Report covers the specific technical activities of Hughes STX Corporation for the last contract triannual period of 1 June through 30 Sep. 1993, in support of assigned task activities at Goddard Space Flight Center (GSFC). It also provides a brief summary of work throughout the contract period of performance on each active task. Technical activity is presented in Volume 1, while financial and level-of-effort data is presented in Volume 2. Technical support was provided to all Division and Laboratories of Goddard's Space Sciences and Earth Sciences Directorates. Types of support include: scientific programming, systems programming, computer management, mission planning, scientific investigation, data analysis, data processing, data base creation and maintenance, instrumentation development, and management services. Mission and instruments supported include: ROSAT, Astro-D, BBXRT, XTE, AXAF, GRO, COBE, WIND, UIT, SMM, STIS, HEIDI, DE, URAP, CRRES, Voyagers, ISEE, San Marco, LAGEOS, TOPEX/Poseidon, Pioneer-Venus, Galileo, Cassini, Nimbus-7/TOMS, Meteor-3/TOMS, FIFE, BOREAS, TRMM, AVHRR, and Landsat. Accomplishments include: development of computing programs for mission science and data analysis, supercomputer applications support, computer network support, computational upgrades for data archival and analysis centers, end-to-end management for mission data flow, scientific modeling and results in the fields of space and Earth physics, planning and design of GSFC VO DAAC and VO IMS, fabrication, assembly, and testing of mission instrumentation, and design of mission operations center.

ESO 243-49 HLX-1: scaling of X-ray spectral properties and black hole mass determination

NASA Astrophysics Data System (ADS)

Titarchuk, Lev; Seifina, Elena

2016-11-01

We report the results of Swift/XRT observations (2008-2015) of a hyper-luminous X-ray source, ESO 243-49 HLX-1. We demonstrate a strong observational evidence that ESO 243-49 HLX-1 undergoes spectral transitions from the low/hard state to the high/soft state during these observations. The spectra of ESO 243-49 HLX-1 are well fitted by the so-called bulk motion Comptonization model for all spectral states. We have established the photon index (Γ) saturation level, Γsat = 3.0 ± 0.1, in the Γ versus mass accretion rate (Ṁ) correlation. This Γ-Ṁ correlation allows us to estimate black hole (BH) mass in ESO 243-49 HLX-1 to be MBH 7 × 104 M⊙ assuming the distance to ESO 243-49 of 95 Mpc. For the BH mass estimate we use the scaling method taking Galactic BHs XTE J1550-564, H 1743-322 and 4U 1630-472, and an extragalactic BH source, M101 ULX-1 as reference sources. The Γ versus Ṁ correlation revealed in ESO 243-49 HLX-1 is similar to those in a number of Galactic and extragalactic BHs and it clearly shows the correlation along with the strong Γ saturation at ≈3. This is a robust observational evidence for the presence of a BH in ESO 243-49 HLX-1. We also find that the seed (disk) photon temperatures are quite low, of order of 50-140 eV which are consistent with high BH mass in ESO 243-49 HLX-1.

CH Cygni. I. Observational Evidence for a Disk-Jet Connection

NASA Astrophysics Data System (ADS)

Sokoloski, J. L.; Kenyon, S. J.

2003-02-01

We investigate the role of accretion in the production of jets in the symbiotic star CH Cygni. Assuming that the rapid stochastic optical variations in CH Cygni come from the accretion disk, as in cataclysmic variables, we use changes in this flickering to diagnose the state of the disk in 1997. At that time, CH Cygni dropped to a very low optical state, and Karovska et al. report that a radio jet was produced. For approximately 1 yr after the jet production, the amplitude of the fastest (timescale of minutes) variations was significantly reduced, although smooth, hour-timescale variations were still present. This light-curve evolution indicates that the inner disk may have been disrupted, or emission from this region suppressed, in association with the mass ejection event. We describe optical spectra that support this interpretation of the flickering changes. The simultaneous state change, jet ejection, and disk disruption suggest a comparison between CH Cygni and some black hole candidate X-ray binaries that show changes in the inner-disk radius in conjunction with discrete ejection events on a wide range of timescales (e.g., the microquasar GRS 1915+105 and XTE J1550-564).

The role of localized junction leakage in the temperature-dependent laser-beam-induced current spectra for HgCdTe infrared focal plane array photodiodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, A. L.; Li, G., E-mail: liguang1971@ahu.edu.cn, E-mail: xschen@mail.sitp.ac.cn; He, G.

2013-11-07

We have performed the study on the dependence of laser beam induced current (LBIC) spectra on the temperature for the vacancy-doped molecular beam epitaxy grown Hg{sub 1−x}Cd{sub x}Te (x = 0.31) photodiodes by both experiment and numerical simulations. It is found that the measured LBIC signal has different distributions for different temperature extents. The LBIC profile tends to be more asymmetric with increasing temperature below 170 K. But the LBIC profile becomes more symmetric with increasing temperature above 170 K. Based on a localized leakage model, it is indicated that the localized junction leakage can lead to asymmetric LBIC signal, in good agreement withmore » the experimental data. The reason is that the trap-assisted tunneling current is the dominant leakage current at the cryogenic temperature below 170 K while the diffusion current component becomes dominant above the temperature of 170 K. The results are helpful for us to better clarify the mechanism of the dependence of LBIC spectra on temperature for the applications of HgCdTe infrared photodiodes.« less

Specific features of the spectra and relaxation kinetics of long-wavelength photoconductivity in narrow-gap HgCdTe epitaxial films and heterostructures with quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rumyantsev, V. V., E-mail: rumyantsev@ipmras.ru; Ikonnikov, A. V.; Antonov, A. V.

2013-11-15

The spectra and relaxation kinetics of interband photoconductivity are investigated in narrow-gap Hg{sub 1-x}Cd{sub x}Te epitaxial films with x = 0.19-0.23 and in structures with HgCdTe-based quantum wells (QWs), having an interband-transition energy in the range of 30-90 meV, grown by molecular-beam epitaxy on GaAs (013) substrates. A long-wavelength sensitivity band caused by impurities or defects is found in the spectra of the structures with quantum wells in addition to the interband photoconductivity. It is shown that the lifetimes of nonequilibrium carriers in the structures with QWs is less than in bulk samples at the same optical-transition energy. From themore » measured carrier lifetimes, the ampere-watt responsivity and the equivalent noise power for a film with x = 0.19 at a wavelength of 19 {mu}m are estimated. When investigating the relaxation kinetics of the photoconductivity at 4.2 K in high excitation regime, it is revealed that radiative recombination is dominant over other mechanisms of nonequilibrium-carrier recombination.« less

Synthesis of monoclinic IrTe 2 under high pressure and its physical properties

DOE PAGES

Li, X.; Yan, J. -Q.; Singh, D. J.; ...

2015-10-12

In a pressure-temperature (P-T) diagram for synthesizing IrTe 2 compounds, the well-studied trigonal (H) phase with the CdI 2-type structure is stable at low pressures. The superconducting cubic (C) phase can be synthesized under higher temperatures and pressures. A rhombohedral phase with the crystal structure similar to the C phase can be made at ambient pressure; but the phase contains a high concentration of Ir deficiency. Here, we report that a rarely studied monoclinic (M) phase can be stabilized in narrow ranges of pressure and temperature in this P-T diagram. Moreover, the peculiar crystal structure of the M-IrTe 2 eliminatesmore » the tendency to form Ir-Ir dimers found in the H phase. The M phase has been fully characterized by structural determination and measurements of electrical resistivity, thermoelectric power, DC magnetization, and specific heat. These physical properties have been compared with those in the H and C phases of Ir 1-xTe 2. Finally, we present magnetic and transport properties and specific heat of the M-IrTe 2 can be fully justified by calculations with the density-functional theory.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Zuocheng; Feng, Xiao; Wang, Jing

The interplay between magnetism and topology, as exemplified in the magnetic skyrmion systems, has emerged as a rich playground for finding novel quantum phenomena and applications in future information technology. Magnetic topological insulators (TI) have attracted much recent attention, especially after the experimental realization of quantum anomalous Hall effect. Future applications of magnetic TI hinge on the accurate manipulation of magnetism and topology by external perturbations, preferably with a gate electric field. In this work, we investigate the magneto transport properties of Cr doped Bi 2(Se xTe 1-x) 3 TI across the topological quantum critical point (QCP). We find thatmore » the external gate voltage has negligible effect on the magnetic order for samples far away from the topological QCP. However, for the sample near the QCP, we observe a ferromagnetic (FM) to paramagnetic (PM) phase transition driven by the gate electric field. Theoretical calculations show that a perpendicular electric field causes a shift of electronic energy levels due to the Stark effect, which induces a topological quantum phase transition and consequently a magnetic phase transition. Finally, the in situ electrical control of the topological and magnetic properties of TI shed important new lights on future topological electronic or spintronic device applications.« less

Hybrid dielectric light trapping designs for thin-film CdZnTe/Si tandem cells

DOE PAGES

Chung, H.; Zhou, C.; Tee, X. T.; ...

2016-05-20

Tandem solar cells consisting of high bandgap cadmium telluride alloys atop crystalline silicon have potential for high efficiencies exceeding the Shockley-Queisser limit. However, experimental results have fallen well below this goal significantly because of non-ideal current matching and light trapping. In this work, we simulate cadmium zinc telluride (CZT) and crystalline silicon (c-Si) tandems as an exemplary system to show the role that a hybrid light trapping and bandgap engineering approach can play in improving performance and lowering materials costs for tandem solar cells incorporating crystalline silicon. This work consists of two steps. First, we optimize absorption in the crystallinemore » silicon layer with front pyramidal texturing and asymmetric dielectric back gratings, which results in 121% absorption enhancement from a planar structure. Then, using this pre-optimized light trapping scheme, we model the dispersion of the Cd xZn 1-xTe alloys, and then adjust the bandgap to realize the best current matching for a range of CZT thicknesses. Using experimental parameters, the corresponding maximum efficiency is predicted to be 16.08 % for a total tandem cell thickness of only 2.2 μm.« less

REPRODUCING THE CORRELATIONS OF TYPE C LOW-FREQUENCY QUASI-PERIODIC OSCILLATION PARAMETERS IN XTE J1550–564 WITH A SPIRAL STRUCTURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varniere, Peggy; Vincent, Frederic H., E-mail: varniere@apc.univ-paris7.fr

While it has been observed that the parameters intrinsic to the type C low-frequency quasi-periodic oscillations are related in a nonlinear manner among themselves, there has been, up to now, no model to explain or reproduce how the frequency, the FWHM, and the rms amplitude of the type C low-frequency quasi-periodic oscillations behave with respect to one another. Here we are using a simple toy model representing the emission from a standard disk and a spiral such as that caused by the accretion–ejection instability to reproduce the overall observed behavior and shed some light on its origin. This allows usmore » to prove the ability of such a spiral structure to be at the origin of flux modulation over more than an order of magnitude in frequency.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malliakas, Christos D.; Chung, Duck Young; Claus, Helmut

Superconductivity was discovered in the layered compound RbBi 11/3Te 6, featuring Bi vacancies and a narrow band gap of 0.25(2) eV at room temperature. In addition, a sharp superconducting transition at similar to 3.2 K was observed in polycrystalline ingots. The superconducting volume fraction of oriented single crystals is almost 100%, confirming bulk superconductivity. Systematic Se and Sb substitutions in RbBi 11/3-ySb ySe xTe 6-x, revealed a dependence of the superconducting transition on composition that can increase the T c up to similar to 10%. The RbBi 11/3Te 6 system is the first member of the new homologous series Rb[Bimore » 2n+11/3Te 3n+6] with infinite Bi 2Te 3-like layers. Lastly, the large degree of chemical tunability of the electronic structure of the homology via doping and/or substitution gives rise to a new family of superconductors.« less

Early NICER Observations of Magnetars and Young Pulsars

NASA Astrophysics Data System (ADS)

Nynka, Melania

2018-01-01

Neutron star Interior Composition ExploreR (NICER) is an X-ray telescope attached to the International Space Station (ISS). Launched in June 2017, it is designed to precisely measure the masses and radii of neutron stars (NS) and probe NS equations of state. But its precision timing capabilities and large effective area uniquely position NICER for the study of magnetars. The NICER Magnetar & Magnetosphere (M&M) science working group focuses on studying highly-magnetized neutron stars, a diverse program that includes magnetars, high-B pulsars, rotation powered pulsars, and isolated neutron stars. Our ongoing campaign has already observed targets such as 4U 0142+61, a magnetar in outburst with coincident NuSTAR and Swift observations, the radio rotation powered Vela pulsar PSR B0833-45, and a transient magnetar XTE J1810-197. I will discuss the goals of the M&M program, spectral and temporal results from the observed targets, and an overview of upcoming observations.

A Circumbinary Disk Model for the Rapid Orbital Shrinkage in Black Hole Low-mass X-Ray Binaries

NASA Astrophysics Data System (ADS)

Xu, Xiao-Tian; Li, Xiang-Dong

2018-05-01

Several black hole low-mass X-ray binaries (BHLMXBs) show very fast orbital shrinkage, which is difficult to understand in the standard picture of the LMXB evolution. Based on the possible detection of a circumbinary (CB) disk in A0620-00 and XTE J1118+480, we investigate the influence of the interaction between a CB disk and the inner binary and calculate the evolution of the binary using the Modules for Experiments in Stellar Astrophysics. We consider two cases for the CB disk formation in which it is fed by mass loss during single outburst or successive outbursts in the LMXB. We show that when taking reasonable values of the initial mass and the dissipating time of the disk, it is possible to explain the fast orbital shrinkage in the BHLMXBs without invoking a high-mass transfer rate.

Charge carrier effective mass and concentration derived from combination of Seebeck coefficient and Te 125 NMR measurements in complex tellurides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levin, E. M.

Thermoelectric materials utilize the Seebeck effect to convert heat to electrical energy. The Seebeck coefficient (thermopower), S, depends on the free (mobile) carrier concentration, n, and effective mass, m*, as S ~ m*/n 2/3. The carrier concentration in tellurides can be derived from 125Te nuclear magnetic resonance (NMR) spin-lattice relaxation measurements. The NMR spin-lattice relaxation rate, 1/T 1, depends on both n and m* as 1/T 1~(m*) 3/2n (within classical Maxwell-Boltzmann statistics) or as 1/T1~(m*) 2n 2/3 (within quantum Fermi-Dirac statistics), which challenges the correct determination of the carrier concentration in some materials by NMR. Here it is shown thatmore » the combination of the Seebeck coefficient and 125Te NMR spin-lattice relaxation measurements in complex tellurides provides a unique opportunity to derive the carrier effective mass and then to calculate the carrier concentration. This approach was used to study Ag xSb xGe 50–2xTe 50, well-known GeTe-based high-efficiency tellurium-antimony-germanium-silver thermoelectric materials, where the replacement of Ge by [Ag+Sb] results in significant enhancement of the Seebeck coefficient. Thus, values of both m* and n derived using this combination show that the enhancement of thermopower can be attributed primarily to an increase of the carrier effective mass and partially to a decrease of the carrier concentration when the [Ag+Sb] content increases.« less

Charge carrier effective mass and concentration derived from combination of Seebeck coefficient and Te 125 NMR measurements in complex tellurides

DOE PAGES

Levin, E. M.

2016-06-27

Thermoelectric materials utilize the Seebeck effect to convert heat to electrical energy. The Seebeck coefficient (thermopower), S, depends on the free (mobile) carrier concentration, n, and effective mass, m*, as S ~ m*/n 2/3. The carrier concentration in tellurides can be derived from 125Te nuclear magnetic resonance (NMR) spin-lattice relaxation measurements. The NMR spin-lattice relaxation rate, 1/T 1, depends on both n and m* as 1/T 1~(m*) 3/2n (within classical Maxwell-Boltzmann statistics) or as 1/T1~(m*) 2n 2/3 (within quantum Fermi-Dirac statistics), which challenges the correct determination of the carrier concentration in some materials by NMR. Here it is shown thatmore » the combination of the Seebeck coefficient and 125Te NMR spin-lattice relaxation measurements in complex tellurides provides a unique opportunity to derive the carrier effective mass and then to calculate the carrier concentration. This approach was used to study Ag xSb xGe 50–2xTe 50, well-known GeTe-based high-efficiency tellurium-antimony-germanium-silver thermoelectric materials, where the replacement of Ge by [Ag+Sb] results in significant enhancement of the Seebeck coefficient. Thus, values of both m* and n derived using this combination show that the enhancement of thermopower can be attributed primarily to an increase of the carrier effective mass and partially to a decrease of the carrier concentration when the [Ag+Sb] content increases.« less

A numerical investigation of wind accretion in persistent supergiant X-ray binaries - I. Structure of the flow at the orbital scale

NASA Astrophysics Data System (ADS)

El Mellah, I.; Casse, F.

2017-05-01

Classical supergiant X-ray binaries host a neutron star orbiting a supergiant OB star and display persistent X-ray luminosities of 1035-1037 erg s-1. The stellar wind from the massive companion is believed to be the main source of matter accreted by the compact object. With this first paper, we introduce a ballistic model to evaluate the influence of the orbital effects on the structure of the accelerating winds that participate to the accretion process. Thanks to the parametrization we retained the numerical pipeline we designed, we can investigate the supersonic flow and the subsequent observables as a function of a reduced set of characteristic numbers and scales. We show that the shape of the permanent flow is entirely determined by the mass ratio, the filling factor, the Eddington factor and the α-force multiplier that drives the stellar wind acceleration. Provided scales such as the orbital period are known, we can trace back the observables to evaluate the mass accretion rates, the accretion mechanism, the shearing of the inflow and the stellar parameters. We discuss the likelihood of wind-formed accretion discs around the accretors in each case and confront our model to three persistent supergiant X-ray binaries (Vela X-1, IGR J18027-2016, XTE J1855-026).

The influence of magnetic order on the magnetoresistance anisotropy of Fe 1 + δ–xCu xTe

DOE PAGES

Helm, T.; Valdivia, P. N.; Bourret-Courchesne, E.; ...

2017-05-17

In this study, e performed resistance measurements onmore » $$\\text{F}{{\\text{e}}_{1+\\delta -x}}$$ Cu x Te with $${{x}_{\\text{EDX}}}\\leqslant 0.06$$ in the presence of in-plane applied magnetic fields, revealing a resistance anisotropy that can be induced at a temperature far below the structural and magnetic zero-field transition temperatures. The observed resistance anisotropy strongly depends on the field orientation with respect to the crystallographic axes, as well as on the field-cooling history. Our results imply a correlation between the observed features and the low-temperature magnetic order. Hysteresis in the angle-dependence indicates a strong pinning of the magnetic order within a temperature range that varies with the Cu content. The resistance anisotropy vanishes at different temperatures depending on whether an external magnetic field or a remnant field is present: the closing temperature is higher in the presence of an external field. For $${{x}_{\\text{EDX}}}=0.06$$ the resistance anisotropy closes above the structural transition, at the same temperature at which the zero-field short-range magnetic order disappears and the sample becomes paramagnetic. Finally, we suggest that under an external magnetic field the resistance anisotropy mirrors the magnetic order parameter. We discuss similarities to nematic order observed in other iron pnictide materials.« less

Reducing On-Board Computer Propagation Errors Due to Omitted Geopotential Terms by Judicious Selection of Uploaded State Vector

NASA Technical Reports Server (NTRS)

Greatorex, Scott (Editor); Beckman, Mark

1996-01-01

Several future, and some current missions, use an on-board computer (OBC) force model that is very limited. The OBC geopotential force model typically includes only the J(2), J(3), J(4), C(2,2) and S(2,2) terms to model non-spherical Earth gravitational effects. The Tropical Rainfall Measuring Mission (TRMM), Wide-field Infrared Explorer (WIRE), Transition Region and Coronal Explorer (TRACE), Submillimeter Wave Astronomy Satellite (SWAS), and X-ray Timing Explorer (XTE) all plan to use this geopotential force model on-board. The Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) is already flying this geopotential force model. Past analysis has shown that one of the leading sources of error in the OBC propagated ephemeris is the omission of the higher order geopotential terms. However, these same analyses have shown a wide range of accuracies for the OBC ephemerides. Analysis was performed using EUVE state vectors that showed the EUVE four day OBC propagated ephemerides varied in accuracy from 200 m. to 45 km. depending on the initial vector used to start the propagation. The vectors used in the study were from a single EUVE orbit at one minute intervals in the ephemeris. Since each vector propagated practically the same path as the others, the differences seen had to be due to differences in the inital state vector only. An algorithm was developed that will optimize the epoch of the uploaded state vector. Proper selection can reduce the previous errors of anywhere from 200 m. to 45 km. to generally less than one km. over four days of propagation. This would enable flight projects to minimize state vector uploads to the spacecraft. Additionally, this method is superior to other methods in that no additional orbit estimates need be done. The definitive ephemeris generated on the ground can be used as long as the proper epoch is chosen. This algorithm can be easily coded in software that would pick the epoch within a specified time range that would minimize the OBC propagation error. This techniques should greatly improve the accuracy of the OBC propagation on-board future spacecraft such as TRMM, WIRE, SWAS, and XTE without increasing complexity in the ground processing.

The long-term evolution of the X-ray pulsar XTE J1814-338: A receding jet contribution to the quiescent optical emission?

NASA Astrophysics Data System (ADS)

Baglio, M. C.; D'Avanzo, P.; Muñoz-Darias, T.; Breton, R. P.; Campana, S.

2013-11-01

Aims: We present a study of the quiescent optical counterpart of the accreting millisecond X-ray pulsar XTE J1814-338 that is aimed at unveiling the different components, which contribute to the quiescent optical emission of the system. Methods: We carried out multiband (BVR) orbital phase-resolved photometry of the system using the ESO Very Large Telescope (VLT) that is equipped with the FORS2 camera, covering about 70% of the 4.3 hour orbital period. Results: The optical light curves are consistent with a sinusoidal variability that are modulated with an orbital period with a semi-amplitude of 0.5-0.7 mag. They show evidence of a strongly irradiated companion star, which agrees with previous findings for this system. However, the observed colours cannot be accounted for by the companion star alone, suggesting the presence of an accretion disc during quiescence. The system seems to be fainter in all analysed bands compared to previous observations. The R band light curve displays a possible phase offset with respect to the B and V band. Through a combined fit of the multi-band light curve performed with a Markov chain Monte Carlo technique, we derive constraints on the companion star, disc fluxes, system distance, and companion star mass. Conclusions: The irradiation luminosity required to account for the observed day-side temperature of the companion star is consistent with the spin-down luminosity of a millisecond radio pulsar. Compared to our data with previous observations, which were collected over 5 years, the flux decrease and spectral evolution of the observed quiescent optical emission cannot be satisfactorily explained with the combined contribution of an irradiated companion star and of an accretion disc alone. The observed progressive flux decrease as the system gets bluer could be due to a continuum component that evolves towards a lower, bluer spectrum. While most of the continuum component is likely due to the disc, we do not expect it to become bluer in quiescence. Hence, we hypothesize that an additional component, such as synchrotron emission from a jet was significantly contributing in the data obtained earlier during quiescence and then progressively fading or moving its break frequency towards longer wavelengths. Based on observations made with ESO Telescopes at the Paranal Observatory under programme ID 383.D-0730(A).

Scaling of the photon index vs. mass accretion rate correlation and estimate of black hole mass in M101 ULX-1

NASA Astrophysics Data System (ADS)

Titarchuk, Lev; Seifina, Elena

2016-01-01

We report the results of Swift and Chandra observations of an ultraluminous X-ray source, ULX-1 in M101. We show strong observational evidence that M101 ULX-1 undergoes spectral transitions from the low/hard state to the high/soft state during these observations. The spectra of M101 ULX-1 are well fitted by the so-called bulk motion Comptonization (BMC) model for all spectral states. We have established the photon index (Γ) saturation level, Γsat = 2.8 ± 0.1, in the Γ versus mass accretion rate (Ṁ) correlation. This Γ-Ṁ correlation allows us to evaluate black hole (BH) mass in M101 ULX-1 to be MBH ~ (3.2-4.3) × 104 M⊙, assuming the spread in distance to M101 (from 6.4 ± 0.5 Mpc to 7.4 ± 0.6 Mpc). For this BH mass estimate we apply the scaling method, using Galactic BHs XTE J1550-564, H 1743-322 and 4U 1630-472 as reference sources. The Γ vs. Ṁ correlation revealed in M101 ULX-1 is similar to that in a number of Galactic BHs and clearly exhibits the correlation along with the strong Γ saturation at ≈ 2.8. This is robust observational evidence for the presence of a BH in M101 ULX-1. We also find that the seed (disk) photon temperatures are low, on the order of 40-100 eV, which is consistent with high BH mass in M101 ULX-1. Thus, we suggest that the central object in M101 ULX-1 has intermediate BH mass on the order of 104 solar masses.

Effects of doping of calcium atom(s) on structural, electronic and optical properties of binary strontium chalcogenides - A theoretical investigation using DFT based FP-LAPW methodology

NASA Astrophysics Data System (ADS)

Bhattacharjee, Rahul; Chattopadhyaya, Surya

2017-09-01

The effects of doping of Ca atom(s) on structural, electronic and optical properties of binary strontium chalcogenide semiconductor compounds have been investigated theoretically using DFT based FP-LAPW approach by modeling the rock-salt (B1) ternary alloys CaxSr1-xS, CaxSr1-xSe and CaxSr1-xTe at some specific concentrations 0 ≤ x ≤ 1 and studying their aforesaid properties. The exchange-correlation potentials for their structural properties have been computed using the Wu-Cohen generalized-gradient approximation (WC-GGA) scheme, while those for the electronic and optical properties have been computed using recently developed Tran-Blaha modified Becke-Johnson (TB-mBJ) scheme. In addition, we have computed the electronic and optical properties with the traditional BLYP and PBE-GGA schemes for comparison. The atomic and orbital origin of different electronic states in the band structure of each of the compounds have been identified from the respective density of states (DOS). Using the approach of Zunger and co-workers, the microscopic origin of band gap bowing has been discussed in term of volume deformation, charge exchange and structural relaxation. Bonding characteristics among the constituent atoms of each of the specimens have been discussed from their charge density contour plots. Optical properties of the binary compounds and ternary alloys have been investigated theoretically in terms of their respective dielectric function, refractive index, normal incidence reflectivity and optical conductivity. Several calculated results have been compared with available experimental and other theoretical data.

The Swift/BAT Hard X-Ray Survey

NASA Technical Reports Server (NTRS)

Tueller, Jack; Markwardt, C. B.; Mushotzky, R. F.; Barthelmy, S. D.; Gehrels, N.; Krimm, H. A.; Skinner, G. K.; Falcone, A.; Kennea, J. A.

2006-01-01

The BAT instrument on Swift is a wide field (70 deg. '100 deg.) coded aperture instrument with a CdZnTe detector array sensitive to energies of 14-200 keV. Each day, the BAT survey typically covers 60% of the sky to a detection limit of 30 millicrab. BAT makes hard X-ray light curves of similar sensitivity and coverage to the X-ray light curves from XTE/ASM, but in an energy range where sources show remarkably different behavior. Integrating the BAT data produces an all sky map with a source detection limit at 15 months of a few 10(exp -11) ergs per square centimeter per second, depending on the exposure. This is the first uniform all-sky survey at energies high enough to be unaffected by absorption since HEAO 1 in 1977-8. BAT has detected greater than 200 AGN and greater than 180 galactic sources. At high galactic latitudes, the BAT sources are usually easy to identify, but many are heavily absorbed and there are a few quite surprising identifications. The BAT selected galaxies can be used to calculate LogN/LogS and the luminosity function for AGN which are complete and free from common systematics. Several crucial parameters for understanding the cosmic hard x-ray background are now determined.

Possible signature of the magnetic fields related to quasi-periodic oscillations observed in microquasars

NASA Astrophysics Data System (ADS)

Kološ, Martin; Tursunov, Arman; Stuchlík, Zdeněk

2017-12-01

The study of quasi-periodic oscillations (QPOs) of X-ray flux observed in the stellar-mass black hole binaries can provide a powerful tool for testing of the phenomena occurring in the strong gravity regime. Magnetized versions of the standard geodesic models of QPOs can explain the observationally fixed data from the three microquasars. We perform a successful fitting of the HF QPOs observed for three microquasars, GRS 1915+105, XTE 1550-564 and GRO 1655-40, containing black holes, for magnetized versions of both epicyclic resonance and relativistic precession models and discuss the corresponding constraints of parameters of the model, which are the mass and spin of the black hole and the parameter related to the external magnetic field. The estimated magnetic field intensity strongly depends on the type of objects giving the observed HF QPOs. It can be as small as 10^{-5} G if electron oscillatory motion is relevant, but it can be by many orders higher for protons or ions (0.02-1 G), or even higher for charged dust or such exotic objects as lighting balls, etc. On the other hand, if we know by any means the magnetic field intensity, our model implies strong limit on the character of the oscillating matter, namely its specific charge.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogedengbe, O. S.; Swartz, C. H.; Jayathilaka, P. A. R. D.

Here, iodine-doped CdTe and Cd 1-xMg xTe layers were grown by molecular beam epitaxy. Secondary ion mass spectrometry characterization was used to measure dopant concentration, while Hall measurement was used for determining carrier concentration. Photoluminescence intensity and time-resolved photoluminescence techniques were used for optical characterization. Maximum n-type carrier concentrations of 7.4 x 10 18 cm -3 for CdTe and 3 x 10 17 cm -3 for Cd 0.65Mg 0.35Te were achieved. Studies suggest that electrically active doping with iodine is limited with dopant concentration much above these values. Dopant activation of about 80% was observed in most of the CdTemore » samples. The estimated activation energy is about 6 meV for CdTe and the value for Cd 0.65Mg 0.35Te is about 58 meV. Iodine-doped samples exhibit long lifetimes with no evidence of photoluminescence degradation with doping as high as 2 x 10 18 cm -3, while indium shows substantial non-radiative recombination at carrier concentrations above 5 x 10 16 cm -3. Iodine was shown to be thermally stable in CdTe at temperatures up to 600 °C. Results suggest iodine may be a preferred n-type dopant compared to indium in achieving heavily doped n-type CdTe.« less

The influence of magnetic order on the magnetoresistance anisotropy of Fe 1+δ–xCu xTe

DOE PAGES

Helm, T.; Valdivia, P. N.; Bourret-Courchesne, E.; ...

2017-06-08

We performed resistance measurements on [Formula: see text]Cu x Te with [Formula: see text] in the presence of in-plane applied magnetic fields, revealing a resistance anisotropy that can be induced at a temperature far below the structural and magnetic zero-field transition temperatures. The observed resistance anisotropy strongly depends on the field orientation with respect to the crystallographic axes, as well as on the field-cooling history. Our results imply a correlation between the observed features and the low-temperature magnetic order. Hysteresis in the angle-dependence indicates a strong pinning of the magnetic order within a temperature range that varies with the Cumore » content. The resistance anisotropy vanishes at different temperatures depending on whether an external magnetic field or a remnant field is present: the closing temperature is higher in the presence of an external field. For [Formula: see text] the resistance anisotropy closes above the structural transition, at the same temperature at which the zero-field short-range magnetic order disappears and the sample becomes paramagnetic. Thus we suggest that under an external magnetic field the resistance anisotropy mirrors the magnetic order parameter. We discuss similarities to nematic order observed in other iron pnictide materials.« less

Monitoring The Crab Pulsar

NASA Technical Reports Server (NTRS)

Rots, Arnold H.; Swank, Jean (Technical Monitor)

2001-01-01

The monitoring of the X-ray pulses from the Crab pulsar is still ongoing at the time of this writing, and we hope to be able to continue the campaign for the life of the XTE mission. We have established beyond all doubt that: (1) the X-ray main pulse leads the radio pulse by approximately 300 microseconds, (2) this phase lag is constant and not influenced by glitches, (3) this lag does not depend on X-ray energy, (4) the relative phase of the two X-ray pulses does not vary, and (5) the spectral indices of primary, secondary, and inter-pulse are distinct and constant. At this time we are investigating whether the radio timing ephemeris can be replaced by an x-ray ephemeris and whether any long-time timing ephemeris can be established. If so, it would enable use to study variations in pulse arrival times at a longer time scales. Such a study is easier in x-rays than at radio wavelengths since the dispersion measure plays no role. These results were reported at the 2000 HEAD Meeting in Honolulu, HI. Travel was paid partly out of this grant. The remainder was applied toward the acquisition of a laptop computer that allows independent and fast analysis of all monitoring observations.

Donor Magneto-Spectroscopy and Magnetic Field - Metal-Insulator Transition in MERCURY(1-X) Cadmium(x)tellurium and Indium Antimonide

NASA Astrophysics Data System (ADS)

Choi, Jung Bum

Far infrared (FIR) magneto-transmission studies of n-type Hg_{1-x}Cd _{x}Te (x = 0.198, 0.204, 0.224, 0.237, 0.270) for temperatures down to 1.5K and magnetic fields up to 9T in Voigt and Faraday geometries have been performed. Magneto-optical transitions of donor bound electrons are observed; including the (000) --> (001) and (010) --> (01k_{z}) in the Voigt geometry, and the (000) --> (110) in the Faraday geometry. These identifications are confirmed by their resonance positions, selection rules, and temperature dependence. The experimental observations are consistent with calculations of resonance positions and lineshapes based on the hydrogenic donor model including central cell effects. This work confirms the donor bound electronic ground state for Hg_{1-x}Cd_{x} Te. The magneto-transport and FIR spectroscopy have been combined to probe the nature of the impurity band in the vicinity of the magnetic field induced metal-insulator transition. The results obtained in Hg_ {1-x}Cd_{x}Te and InSb show the persistance of the (000) --> (110) impurity transition through the metal-insulator critical field. This observation demonstrates the existence of the metallic impurity band which is split off from the conduction band. In the studies of the critical behavior of InSb, the conductivity measured for temperatures down to 0.45K shows a dominant linear dependence on temperature near the transition field. Furthermore, the zero-temperature extrapolated conductivity was found to drop continuously to zero at the transition field with a critical exponent of nu = 1.07 +/- 0.07.

Observational aspects of outbursting black hole sources: Evolution of spectro-temporal features and X-ray variability

NASA Astrophysics Data System (ADS)

Sreehari, H.; Nandi, Anuj; Radhika, D.; Iyer, Nirmal; Mandal, Samir

2018-02-01

We report on our attempt to understand the outbursting profile of Galactic Black Hole sources, keeping in mind the evolution of temporal and spectral features during the outburst. We present results of evolution of quasi-periodic oscillations, spectral states and possible connection with jet ejections during the outburst phase. Further, we attempt to connect the observed X-ray variabilities (i.e., `class'/`structured' variabilities, similar to GRS 1915+105) with spectral states of black hole sources. Towards these studies, we consider three black hole sources that have undergone single (XTE J1859+226), a few (IGR J17091-3624) and many (GX 339-4) outbursts since the start of RXTE era. Finally, we model the broadband energy spectra (3-150 keV) of different spectral states using RXTE and NuSTAR observations. Results are discussed in the context of two-component advective flow model, while constraining the mass of the three black hole sources.

Sensitivity of an underwater Čerenkov km 3 telescope to TeV neutrinos from Galactic microquasars

NASA Astrophysics Data System (ADS)

Aiello, S.; Ambriola, M.; Ameli, F.; Amore, I.; Anghinolfi, M.; Anzalone, A.; Barbarino, G.; Barbarito, E.; Battaglieri, M.; Bellotti, R.; Beverini, N.; Bonori, M.; Bouhadef, B.; Brescia, M.; Cacopardo, G.; Cafagna, F.; Capone, A.; Caponetto, L.; Castorina, E.; Ceres, A.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coniglione, R.; Cordelli, M.; Costa, M.; Cuneo, S.; D'Amico, A.; De Bonis, G.; De Marzo, C.; De Rosa, G.; De Vita, R.; Distefano, C.; Falchini, E.; Fiorello, C.; Flaminio, V.; Fratini, K.; Gabrielli, A.; Galeotti, S.; Gandolfi, E.; Giacomelli, G.; Giorgi, F.; Grimaldi, A.; Habel, R.; Leonora, E.; Lonardo, A.; Longo, G.; Lo Presti, D.; Lucarelli, F.; Maccioni, E.; Margiotta, A.; Martini, A.; Masullo, R.; Megna, R.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Musumeci, M.; Nicolau, C. A.; Orlando, A.; Osipenko, M.; Osteria, G.; Papaleo, R.; Pappalardo, V.; Petta, C.; Piattelli, P.; Raia, G.; Randazzo, N.; Reito, S.; Ricco, G.; Riccobene, G.; Ripani, M.; Rovelli, A.; Ruppi, M.; Russo, G. V.; Russo, S.; Sapienza, P.; Sedita, M.; Shirokov, E.; Simeone, F.; Sipala, V.; Spurio, M.; Taiuti, M.; Terreni, G.; Trasatti, L.; Urso, S.; Valente, V.; Vicini, P.

2007-09-01

In this paper are presented the results of Monte Carlo simulations on the capability of the proposed NEMO-km 3 telescope to detect TeV muon neutrinos from Galactic microquasars. For each known microquasar we compute the number of detectable events, together with the atmospheric neutrino and muon background events. We also discuss the detector sensitivity to neutrino fluxes expected from known microquasars, optimizing the event selection also to reject the background; the number of events surviving the event selection are given. The best candidates are the steady microquasars SS433 and GX339-4 for which we estimate a sensitivity of about 5 × 10 -11 erg/cm 2 s; the predicted fluxes are expected to be well above this sensitivity. For bursting microquasars the most interesting candidates are Cygnus X-3, GRO J1655-40 and XTE J1118+480: their analyses are more complicated because of the stochastic nature of the bursts.

Current Perspectives in High Energy Astrophysics

NASA Technical Reports Server (NTRS)

Ormes, Jonathan F. (Editor)

1996-01-01

High energy astrophysics is a space-age discipline that has taken a quantum leap forward in the 1990s. The observables are photons and particles that are unable to penetrate the atmosphere and can only be observed from space or very high altitude balloons. The lectures presented as chapters of this book are based on the results from the Compton Gamma-Ray Observatory (CGRO) and Advanced Satellite for Cosmology and Astrophysics (ASCA) missions to which the Laboratory for High Energy Astrophysics at NASA's Goddard Space Flight Center made significant hardware contributions. These missions study emissions from very hot plasmas, nuclear processes, and high energy particle interactions in space. Results to be discussed include gamma-ray beaming from active galactic nuclei (AGN), gamma-ray emission from pulsars, radioactive elements in the interstellar medium, X-ray emission from clusters of galaxies, and the progress being made to unravel the gamma-ray burst mystery. The recently launched X-ray Timing Explorer (XTE) and prospects for upcoming Astro-E and Advanced X-ray Astronomy Satellite (AXAF) missions are also discussed.

Can isolated single black holes produce X-ray novae?

NASA Astrophysics Data System (ADS)

Matsumoto, Tatsuya; Teraki, Yuto; Ioka, Kunihito

2018-03-01

Almost all black holes (BHs) and BH candidates in our Galaxy have been discovered as soft X-ray transients, so-called X-ray novae. X-ray novae are usually considered to arise from binary systems. Here, we propose that X-ray novae are also caused by isolated single BHs. We calculate the distribution of the accretion rate from interstellar matter to isolated BHs, and find that BHs in molecular clouds satisfy the condition of the hydrogen-ionization disc instability, which results in X-ray novae. The estimated event rate is consistent with the observed one. We also check an X-ray novae catalogue (Corral-Santana et al.) and find that 16/59 ˜ 0.27 of the observed X-ray novae are potentially powered by isolated BHs. The possible candidates include IGR J17454-2919, XTE J1908-094, and SAX J1711.6-3808. Near-infrared photometric and spectroscopic follow-ups can exclude companion stars for a BH census in our Galaxy.

Superconductivity in the Narrow Gap Semiconductor RbBi 11/3Te 6

DOE PAGES

Malliakas, Christos D.; Chung, Duck Young; Claus, Helmut; ...

2016-10-16

Superconductivity was discovered in the layered compound RbBi 11/3Te 6, featuring Bi vacancies and a narrow band gap of 0.25(2) eV at room temperature. In addition, a sharp superconducting transition at similar to 3.2 K was observed in polycrystalline ingots. The superconducting volume fraction of oriented single crystals is almost 100%, confirming bulk superconductivity. Systematic Se and Sb substitutions in RbBi 11/3-ySb ySe xTe 6-x, revealed a dependence of the superconducting transition on composition that can increase the T c up to similar to 10%. The RbBi 11/3Te 6 system is the first member of the new homologous series Rb[Bimore » 2n+11/3Te 3n+6] with infinite Bi 2Te 3-like layers. Lastly, the large degree of chemical tunability of the electronic structure of the homology via doping and/or substitution gives rise to a new family of superconductors.« less

The Orbit and Position of the X-ray Pulsar XTE J1855-026: An Eclipsing Supergiant System

NASA Technical Reports Server (NTRS)

Corbet, Robin H. D.; Mukai, Koji; White, Nicholas E. (Technical Monitor)

2002-01-01

A pulse timing orbit has been obtained for the X-ray binary XTEJ1855-026 using observations made with the Proportional Counter Array on board the Rossi X-ray Timing Explorer. The mass function obtained of approximately 16 solar mass together with the detection of an extended near-total eclipse confirm that the primary star is supergiant as predicted. The orbital eccentricity is found to be very low with a best fit value of 0.04 +/- 0.02. The orbital period is also refined to be 6.0724 +/- 0.0009 days using an improved and extended light curve obtained with RXTE's All Sky Monitor. Observations with the ASCA satellite provide an improved source location of R.A.= 18 hr 55 min 31.3 sec, decl.= -02 deg 36 min 24.0 sec (2000) with an estimated systematic uncertainty of less than 12 min. A serendipitous new source, AX J1855.4-0232, was also discovered during the ASCA observations.

Imaging photovoltaic infrared CdHgTe detectors

NASA Astrophysics Data System (ADS)

Haakenaasen, R.; Steen, H.; Selvig, E.; Lorentzen, T.; van Rheenen, A. D.; Trosdahl-Iversen, L.; Hall, D.; Gordon, N.; Skauli, T.; Vaskinn, A. H.

2006-09-01

CdxHg1-xTe layers with bandgap in the mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) regions were grown by molecular beam epitaxy, and one-dimensional (1D) and two-dimensional (2D) arrays of planar photodiodes were fabricated by ion milling of vacancy-doped layers. The grown layers have varying densities of needle-shaped structures on the surface. The needles are not associated with twins or dislocations in the layers, but could instead be due to (111) facets being reinforced by a preferential Te diffusion direction over steps on the surface. The needles do not seem to affect diode quality. 64 element 1D arrays of 26×26 μm2 or 26×56 μm2 diodes were processed, and zero-bias resistance-times-area values (R0A) at 77 K of 4×106 Ω cm2 at cutoff wavelength λCO=4.5 μm were measured, as well as high quantum efficiencies. To avoid creating a leakage current during ball-bonding to the 1D array diodes, a ZnS layer was deposited on top of the CdTe passivation layer, as well as extra electroplated Au on the bonding pads. The median measured noise equivalent temperature difference (NETD) on a LWIR array was 14 mK for the 42 operable diodes. 2D arrays showed reasonably good uniformity of R0A and zero-bias current (I0) values. The first 64×64 element 2D array of 16×16 μm2 MWIR diodes has been hybridized to read-out electronics and gave median NETD of 60 mK. Images from both a 1D and a 2D array are shown.

Study on the effect of Cd-diffusion annealing on the electrical properties of CdZnTe

NASA Astrophysics Data System (ADS)

Wanwan, Li; Zechun, Cao; Bin, Zhang; Feng, Zhan; Hongtao, Liu; Wenbin, Sang; Jiahua, Min; Kang, Sun

2006-06-01

In order to meet the requirements for the device design of radiation detectors, CdZnTe (or Cd 1-xZn xTe) crystals grown by Vertical Bridgman Method often need subsequent annealing to increase their resistivity. The nature of this treatment is a diffusion process. Thus, it is meaningful to relate the change of resistivity to the diffusion parameters. A model correlating resistivity and conduction type of CdZnTe with the main diffusion parameter—diffusion coefficient—is put forward in this paper. Combining the model with the analysis of our experimental data, DCd=1.464×10 -10, 1.085×10 -11 and 4.167×10 -13 cm 2/s are the values of Cd self-diffusion coefficient in Cd 0.9Zn 0.1Te at 1073, 973 and 873 K, respectively. The data coincide closely with the Cd self-diffusion coefficient in CdTe provided by different authors [E.D. Jones, N.M. Stewart, Self-diffusion of cadmium in cadmium telluride, J. Crystal Growth 84 (1987) 289-294; P.M. Borsenberger, D.A. Stevenson, J. Phys. Chem. Solids 29 (1968) 1277; R.C. Whelan, D. Shaw, in: D.G. Thomas (Ed.), II -VI Semiconductor Compounds, Benjamin, New York, 1967, p. 451]. With the data, the effects of annealing time on the change of resistivity and conduction type for Cd 0.9Zn 0.1Te wafers, which are annealed in saturated Cd vapor at 1073, 973 and 873 K, were simulated, and good consistency was found. This work suggests an alternative way to obtain the diffusion coefficient in semiconductor materials and also enables ones to analyze the diffusion process quantitatively and predict the annealing results.

Minority carrier lifetime in iodine-doped molecular beam epitaxy-grown HgCdTe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madni, I.; Umana-Membreno, G. A.; Lei, W.

2015-11-02

The minority carrier lifetime in molecular beam epitaxy grown layers of iodine-doped Hg{sub 1−x}Cd{sub x}Te (x ∼ 0.3) on CdZnTe substrates has been studied. The samples demonstrated extrinsic donor behavior for carrier concentrations in the range from 2 × 10{sup 16} cm{sup −3} to 6 × 10{sup 17} cm{sup −3} without any post-growth annealing. At a temperature of 77 K, the electron mobility was found to vary from 10{sup 4} cm{sup 2}/V s to 7 × 10{sup 3} cm{sup 2}/V s and minority carrier lifetime from 1.6 μs to 790 ns, respectively, as the carrier concentration was increased from 2 × 10{sup 16} cm{supmore » −3} to 6 × 10{sup 17} cm{sup −3}. The diffusion of iodine is much lower than that of indium and hence a better alternative in heterostructures such as nBn devices. The influence of carrier concentration and temperature on the minority carrier lifetime was studied in order to characterize the carrier recombination mechanisms. Measured lifetimes were also analyzed and compared with the theoretical models of the various recombination processes occurring in these materials, indicating that Auger-1 recombination was predominant at higher doping levels. An increase in deep-level generation-recombination centers was observed with increasing doping level, which suggests that the increase in deep-level trap density is associated with the incorporation of higher concentrations of iodine into the HgCdTe.« less

Imaging Dirac-mass disorder from magnetic dopant atoms in the ferromagnetic topological insulator Crx(Bi0.1Sb0.9)2-xTe3.

PubMed

Lee, Inhee; Kim, Chung Koo; Lee, Jinho; Billinge, Simon J L; Zhong, Ruidan; Schneeloch, John A; Liu, Tiansheng; Valla, Tonica; Tranquada, John M; Gu, Genda; Davis, J C Séamus

2015-02-03

To achieve and use the most exotic electronic phenomena predicted for the surface states of 3D topological insulators (TIs), it is necessary to open a "Dirac-mass gap" in their spectrum by breaking time-reversal symmetry. Use of magnetic dopant atoms to generate a ferromagnetic state is the most widely applied approach. However, it is unknown how the spatial arrangements of the magnetic dopant atoms influence the Dirac-mass gap at the atomic scale or, conversely, whether the ferromagnetic interactions between dopant atoms are influenced by the topological surface states. Here we image the locations of the magnetic (Cr) dopant atoms in the ferromagnetic TI Cr0.08(Bi0.1Sb0.9)1.92Te3. Simultaneous visualization of the Dirac-mass gap Δ(r) reveals its intense disorder, which we demonstrate is directly related to fluctuations in n(r), the Cr atom areal density in the termination layer. We find the relationship of surface-state Fermi wavevectors to the anisotropic structure of Δ(r) not inconsistent with predictions for surface ferromagnetism mediated by those states. Moreover, despite the intense Dirac-mass disorder, the anticipated relationship [Formula: see text] is confirmed throughout and exhibits an electron-dopant interaction energy J* = 145 meV·nm(2). These observations reveal how magnetic dopant atoms actually generate the TI mass gap locally and that, to achieve the novel physics expected of time-reversal symmetry breaking TI materials, control of the resulting Dirac-mass gap disorder will be essential.

Imaging Dirac-mass disorder from magnetic dopant atoms in the ferromagnetic topological insulator Crx(Bi0.1Sb0.9)2-xTe3

PubMed Central

Lee, Inhee; Kim, Chung Koo; Lee, Jinho; Billinge, Simon J. L.; Zhong, Ruidan; Schneeloch, John A.; Liu, Tiansheng; Valla, Tonica; Tranquada, John M.; Gu, Genda; Davis, J. C. Séamus

2015-01-01

To achieve and use the most exotic electronic phenomena predicted for the surface states of 3D topological insulators (TIs), it is necessary to open a “Dirac-mass gap” in their spectrum by breaking time-reversal symmetry. Use of magnetic dopant atoms to generate a ferromagnetic state is the most widely applied approach. However, it is unknown how the spatial arrangements of the magnetic dopant atoms influence the Dirac-mass gap at the atomic scale or, conversely, whether the ferromagnetic interactions between dopant atoms are influenced by the topological surface states. Here we image the locations of the magnetic (Cr) dopant atoms in the ferromagnetic TI Cr0.08(Bi0.1Sb0.9)1.92Te3. Simultaneous visualization of the Dirac-mass gap Δ(r) reveals its intense disorder, which we demonstrate is directly related to fluctuations in n(r), the Cr atom areal density in the termination layer. We find the relationship of surface-state Fermi wavevectors to the anisotropic structure of Δ(r) not inconsistent with predictions for surface ferromagnetism mediated by those states. Moreover, despite the intense Dirac-mass disorder, the anticipated relationship Δ(r)∝n(r) is confirmed throughout and exhibits an electron–dopant interaction energy J* = 145 meV·nm2. These observations reveal how magnetic dopant atoms actually generate the TI mass gap locally and that, to achieve the novel physics expected of time-reversal symmetry breaking TI materials, control of the resulting Dirac-mass gap disorder will be essential. PMID:25605947

Engineering the Structural and Electronic Phases of MoTe 2 through W Substitution

DOE PAGES

Rhodes, D.; Chenet, D. A.; Janicek, B. E.; ...

2017-02-01

MoTe 2 is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T'- or β-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ~1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronicmore » phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe2 through W substitution by unveiling the phase-diagram of the Mo 1–xW xTe 2 solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration xc ~ 8% stabilizes the γ-phase at room temperature. Lastly, this suggests that crystals with x close to xc might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe 2.« less

Torque Enhancement, Spin Equilibrium, and Jet Power from Disk-Induced Opening of Pulsar Magnetic Fields

NASA Astrophysics Data System (ADS)

Parfrey, Kyle; Spitkovsky, Anatoly; Beloborodov, Andrei M.

2016-05-01

The interaction of a rotating star’s magnetic field with a surrounding plasma disk lies at the heart of many questions posed by neutron stars in X-ray binaries. We consider the opening of stellar magnetic flux due to differential rotation along field lines coupling the star and disk, using a simple model for the disk-opened flux, the torques exerted on the star by the magnetosphere, and the power extracted by the electromagnetic wind. We examine the conditions under which the system enters an equilibrium spin state, in which the accretion torque is instantaneously balanced by the pulsar wind torque alone. For magnetic moments, spin frequencies, and accretion rates relevant to accreting millisecond pulsars, the spin-down torque from this enhanced pulsar wind can be substantially larger than that predicted by existing models of the disk-magnetosphere interaction, and is in principle capable of maintaining spin equilibrium at frequencies less than 1 kHz. We speculate that this mechanism may account for the non-detection of frequency increases during outbursts of SAX J1808.4-3658 and XTE J1814-338, and may be generally responsible for preventing spin-up to sub-millisecond periods. If the pulsar wind is collimated by the surrounding environment, the resulting jet can satisfy the power requirements of the highly relativistic outflows from Cir X-1 and Sco X-1. In this framework, the jet power scales relatively weakly with accretion rate, {L}{{j}}\\propto {\\dot{M}}4/7, and would be suppressed at high accretion rates only if the stellar magnetic moment is sufficiently low.

Evolution of Accretion Disc Geometry of GRS 1915+105 during its χ state as revealed by TCAF solution

NASA Astrophysics Data System (ADS)

Dutta, Broja G.; Pal, Partha Sarathi; Chakrabarti, Sandip K.

2018-06-01

The evolution of the C-type low frequency quasi-periodic oscillations (LFQPOs) and associated time lag in transient black hole sources as a function of time can be explained by variation of the Compton cloud size in a Two Component Advective Flow solution (TCAF). A similar study of a persistent source, GRS 1915+105, has not been attempted. We fit the evolution of QPOs with propagatory oscillating shock (POS) solution for two sets of so-called χ-state observations and find that the shock steadily recedes with almost constant velocity when QPO frequency is decreasing and the spectrum is hardening. The shock moves inward with a constant velocity v0 = 473.0 cm s-1 and v0 = 400.0 cm s-1 respectively in these two cases, when the QPO frequency is increasing and the spectrum softens. This behavior is similar to what was observed in XTE J1550-564 during the 1998 outburst. The time lag measured at the QPO frequency varies in a similar way as the size of the Compton cloud. Most interestingly, in both the cases, the lag switches sign (hard lag to soft lag) at a QPO frequency of ˜2.3 - 2.5 Hz irrespective of the energy of photons. We find, at very low frequencies <1 Hz, the Comptonizing Efficiency (CE) increases with QPO frequency and at higher QPO frequencies the trend is opposite. The time lags become mostly positive at all energies when CE is larger than ˜0.85% for both the sources.

Three Spectral States of the Disk X-Ray Emission of the Black-Hole Candidate 4U 1630- 47

NASA Astrophysics Data System (ADS)

Abe, Yukiko; Fukazawa, Yasushi; Kubota, Aya; Kasama, Daisuke; Makishima, Kazuo

2005-08-01

We studied a time history of X-ray spectral states of a black-hole candidate, 4U 1630-47, utilizing data from a number of monitoring observations with the Rossi X-Ray Timing Explorer over 1996-2004. These observations covered five outbursts of 4U 1630-47, and recorded typical features of the high/soft states. The spectra in the high/soft states can be classified into three states. The first state is explained by a concept of the standard accretion disk picture. The second appears in the very high state, where a dominant hard component is seen and the disk radius apparently becomes too small. These phenomena are explained by the effect of inverse Compton scattering of disk photons, as shown by Kubota, Makishima, and Ebisawa (2001, ApJ, 560, L147) for GRO J1655-40. The third shows that the disk luminosity varies in proportion to Tin2, rather than Tin4, where Tin is the inner-disk temperature. This state suggests an optically-thick and advection-dominated slim disk, as given by Kubota and Makishima (2004, ApJ, 601, 428) for XTE J1550-564. The second and third states appear, with good reproducibility, when Tin and the total X-ray luminosity are higher than 1.2keV and ˜ 2.5 × 1038(D/10 kpc)² [cosθ/(1/√3)]-1 erg s-1, respectively, where D is the distance to the object and θ is the inclination angle to the disk. The results suggest that these spectral states commonly appear among black-hole binaries under high accretion rates.

XTE Proposal #20102--"SS 433's High Energy Spectrum"

NASA Technical Reports Server (NTRS)

Band, David L.; Blanco, P.; Rothschild, R.; Kawai, N.; Kotani, T.; Oka, T.; Wagner, R. M.; Hjellming, R.; Rupen, M.; Brinkmann, W.

1999-01-01

We observed the jet-producing compact binary system SS 433 with RXTE during three multiwavelength campaigns, the first in conjunction with ASCA observations, the second simultaneous with a VLA-VLBA-MERLIN campaign, and the third associated with a Nobeyama millimeter-band campaign. All these campaigns included optical observations. Occurring at different jet precession and binary phases, the observations also monitored the system during a radio flare. The data provide SS 433's X-ray spectrum over more than an energy decade, and track the spectral variations as the X-ray source was partially eclipsed. The continuum can be modeled as a power law with an exponential cutoff, which can be detected to approximately 50 keV. Strong line emission is evident in the 5-10 keV range which can be modeled as a broad line whose energy is precession independent and a narrow line whose energy does vary with jet precession phase; this line model is clearly an over simplification since the PCA does not have sufficient energy resolution to detect the lines ASCA observed. The eclipses are deeper at high energy and at jet precession phases when the jets are more inclined towards and away from us. A large radio flare occurred between two sets of X-ray monitoring observations; an X-ray observation at the peak of the flare found a softer spectrum with a flux approximately 1/3 that of the quiescent level.

Iodine Doping of CdTe and CdMgTe for Photovoltaic Applications

DOE PAGES

Ogedengbe, O. S.; Swartz, C. H.; Jayathilaka, P. A. R. D.; ...

2017-06-06

Here, iodine-doped CdTe and Cd 1-xMg xTe layers were grown by molecular beam epitaxy. Secondary ion mass spectrometry characterization was used to measure dopant concentration, while Hall measurement was used for determining carrier concentration. Photoluminescence intensity and time-resolved photoluminescence techniques were used for optical characterization. Maximum n-type carrier concentrations of 7.4 x 10 18 cm -3 for CdTe and 3 x 10 17 cm -3 for Cd 0.65Mg 0.35Te were achieved. Studies suggest that electrically active doping with iodine is limited with dopant concentration much above these values. Dopant activation of about 80% was observed in most of the CdTemore » samples. The estimated activation energy is about 6 meV for CdTe and the value for Cd 0.65Mg 0.35Te is about 58 meV. Iodine-doped samples exhibit long lifetimes with no evidence of photoluminescence degradation with doping as high as 2 x 10 18 cm -3, while indium shows substantial non-radiative recombination at carrier concentrations above 5 x 10 16 cm -3. Iodine was shown to be thermally stable in CdTe at temperatures up to 600 °C. Results suggest iodine may be a preferred n-type dopant compared to indium in achieving heavily doped n-type CdTe.« less

Intensity- and temperature- dependent carrier recombination in InAs/In(As 1-xSb x) type-II superlattices

DOE PAGES

Olson, Benjamin Varberg; Kadlec, Emil Andrew; Kim, Jin K.; ...

2015-04-17

Our time-resolved measurements for carrier recombination are reported as a midwave infrared InAs/InAs 0.66Sb 0.34 type-II superlattice (T2SL) function of pump intensity and sample temperature. By including the T2SL doping level in the analysis, the Shockley-Read-Hall (SRH), radiative, and Auger recombination components of the carrier lifetime are uniquely distinguished at each temperature. SRH is the limiting recombination mechanism for excess carrier densities less than the doping level (the low-injection regime) and temperatures less than 175 K. A SRH defect energy of 95 meV, either below the T2SL conduction-band edge or above the T2SL valence-band edge, is identified. Auger recombination limitsmore » the carrier lifetimes for excess carrier densities greater than the doping level (the high-injection regime) for all temperatures tested. Additionally, at temperatures greater than 225 K, Auger recombination also limits the low-injection carrier lifetime due to the onset of the intrinsic temperature range and large intrinsic carrier densities. Radiative recombination is found to not have a significant contribution to the total lifetime for all temperatures and injection regimes, with the data implying a photon recycling factor of 15. Using the measured lifetime data, diffusion currents are calculated and compared to calculated Hg 1-xCd xTe dark current, indicating that the T2SL can have a lower dark current with mitigation of the SRH defect states. Our results illustrate the potential for InAs/InAs 1-xSb x T2SLs as absorbers in infrared photodetectors.« less

Repair bond strength of nanohybrid composite resins with a universal adhesive

PubMed Central

Altinci, Pinar; Mutluay, Murat; Tezvergil-Mutluay, Arzu

2018-01-01

Abstract Objective: To investigate the repair bond strength of fresh and aged nanohybrid and hybrid composite resins using a universal adhesive (UA). Materials and methods: Fresh and aged substrates were prepared using two nanohybrid (Venus Pearl, Heraus Kulzer; Filtek Supreme XTE, 3 M ESPE) and one hybrid (Z100, 3 M ESPE) composite resin, and randomly assigned to different surface treatments: (1) no treatment (control), (2) surface roughening with 320-grit (SR), (3) SR + UA (iBOND, Heraus Kulzer), (4) SR + Silane (Signum, Ceramic Bond I, Heraeus Kulzer) + UA, (5) SR + Sandblasting (CoJet, 3 M ESPE) + Silane + UA. After surface treatment, fresh composite resin was added to the substrates at 2 mm layer increments to a height of 5 mm, and light cured. Restored specimens were water-stored for 24 h and sectioned to obtain 1.0 × 1.0 mm beams (n = 12), and were either water-stored for 24 h at 37 °C, or water-stored for 24 h, and then thermocycled for 6000 cycles before microtensile bond strength (µTBS) testing. Data were analyzed with ANOVA and Tukey’s HSD tests (p = .05). Results: Combined treatment of SR, sandblasting, silane and UA provided repair bond strength values comparable to the cohesive strength of each tested resin material (p < .05). Thermocycling significantly reduced the cohesive strength of the composite resins upto 65% (p < .05). Repair bond strengths of UA-treated groups were more stable under thermocycling. Conclusions: Universal adhesive application is a reliable method for composite repair. Sandblasting and silane application slightly increases the repair strength for all substrate types. PMID:29250576

Repair bond strength of nanohybrid composite resins with a universal adhesive.

PubMed

Altinci, Pinar; Mutluay, Murat; Tezvergil-Mutluay, Arzu

2018-01-01

Objective: To investigate the repair bond strength of fresh and aged nanohybrid and hybrid composite resins using a universal adhesive (UA). Materials and methods: Fresh and aged substrates were prepared using two nanohybrid (Venus Pearl, Heraus Kulzer; Filtek Supreme XTE, 3 M ESPE) and one hybrid (Z100, 3 M ESPE) composite resin, and randomly assigned to different surface treatments: (1) no treatment (control), (2) surface roughening with 320-grit (SR), (3) SR + UA (iBOND, Heraus Kulzer), (4) SR + Silane (Signum, Ceramic Bond I, Heraeus Kulzer) + UA, (5) SR + Sandblasting (CoJet, 3 M ESPE) + Silane + UA. After surface treatment, fresh composite resin was added to the substrates at 2 mm layer increments to a height of 5 mm, and light cured. Restored specimens were water-stored for 24 h and sectioned to obtain 1.0 × 1.0 mm beams ( n  = 12), and were either water-stored for 24 h at 37 °C, or water-stored for 24 h, and then thermocycled for 6000 cycles before microtensile bond strength (µTBS) testing. Data were analyzed with ANOVA and Tukey's HSD tests ( p  = .05). Results: Combined treatment of SR, sandblasting, silane and UA provided repair bond strength values comparable to the cohesive strength of each tested resin material ( p  < .05). Thermocycling significantly reduced the cohesive strength of the composite resins upto 65% ( p  < .05). Repair bond strengths of UA-treated groups were more stable under thermocycling. Conclusions: Universal adhesive application is a reliable method for composite repair. Sandblasting and silane application slightly increases the repair strength for all substrate types.

Upper Bounds on r-Mode Amplitudes from Observations of Low-Mass X-Ray Binary Neutron Stars

NASA Technical Reports Server (NTRS)

Mahmoodifar, Simin; Strohmayer, Tod

2013-01-01

We present upper limits on the amplitude of r-mode oscillations and gravitational-radiation-induced spin-down rates in low-mass X-ray binary neutron stars, under the assumption that the quiescent neutron star luminosity is powered by dissipation from a steady-state r-mode. For masses <2M solar mass we find dimensionless r-mode amplitudes in the range from about 1×10(exp-8) to 1.5×10(exp-6). For the accreting millisecond X-ray pulsar sources with known quiescent spin-down rates, these limits suggest that approx. less than 1% of the observed rate can be due to an unstable r-mode. Interestingly, the source with the highest amplitude limit, NGC 6440, could have an r-mode spin-down rate comparable to the observed, quiescent rate for SAX J1808-3658. Thus, quiescent spin-down measurements for this source would be particularly interesting. For all sources considered here, our amplitude limits suggest that gravitational wave signals are likely too weak for detection with Advanced LIGO. Our highest mass model (2.21M solar mass) can support enhanced, direct Urca neutrino emission in the core and thus can have higher r-mode amplitudes. Indeed, the inferred r-mode spin-down rates at these higher amplitudes are inconsistent with the observed spin-down rates for some of the sources, such as IGR J00291+5934 and XTE J1751-305. In the absence of other significant sources of internal heat, these results could be used to place an upper limit on the masses of these sources if they were made of hadronic matter, or alternatively it could be used to probe the existence of exotic matter in them if their masses were known.

Influence of Cavity Margin Design and Restorative Material on Marginal Quality and Seal of Extended Class II Resin Composite Restorations In Vitro.

PubMed

Soliman, Sebastian; Preidl, Reinhard; Karl, Sabine; Hofmann, Norbert; Krastl, Gabriel; Klaiber, Bernd

2016-01-01

To investigate the influence of three cavity designs on the marginal seal of large Class II cavities restored with low-shrinkage resin composite limited to the enamel. One hundred twenty (120) intact human molars were randomly divided into 12 groups, with three different cavity designs: 1. undermined enamel, 2. box-shaped, and 3. proximal bevel. The teeth were restored with 1. an extra-low shrinkage (ELS) composite free of diluent monomers, 2. microhybrid composite (Herculite XRV), 3. nanohybrid composite (Filtek Supreme XTE), and 4. silorane-based composite (Filtek Silorane). After artificial aging by thermocycling and storage in physiological saline, epoxy resin replicas were prepared. To determine the integrity of the restorations' approximal margins, two methods were sequentially employed: 1. replicas were made of the 120 specimens and examined using SEM, and 2. the same 120 specimens were immersed in AgNO3 solution, and the dye penetration depth was observed with a light microscope. Statistical analysis was performed using the Kruskal-Wallis and the Dunn-Bonferroni tests. After bevel preparation, SEM observations showed that restorations did not exhibit a higher percentage of continuous margin (SEM-analysis; p>0.05), but more leakage was found than with the other cavity designs (p<0.05). The lowest percentage of continuous margin was observed in ELS restorations (p<0.05). More fractured margins were observed in the undermined enamel cavity design groups (p<0.05). Bevel preparation failed to improve margin quality in large Class II composite restorations and is no longer recommended. However, undermined enamel should be removed to prevent enamel fractures.

Influence of Mn concentration on magnetic topological insulator Mn xBi 2−xTe 3 thin-film Hall-effect sensor

DOE PAGES

Ni, Y.; Zhang, Z.; Nlebedim, I. C.; ...

2015-06-11

Hall-effect (HE) sensors based on high-quality Mn-doped Bi 2Te 3 topological insulator (TI) thin films have been systematically studied in this paper. Improvement of Hall sensitivity is found after doping the magnetic element Mn into Bi 2Te 3. The sensors with low Mn concentrations, Mn xBi 2-xTe 3, x = 0.01 and 0.08 show the linear behavior of Hall resistance with sensitivity about 5 Ω/T. And their Hall sensitivity shows weak dependence on temperature. For sensors with high Mn concentration (x = 0.23), the Hall resistance with respect to magnetic field shows a hysteretic behavior. Moreover, its sensitivity shows almostmore » eight times as high as that of the HE sensors with low Mn concentration. The highest sensitivity can reach 43 Ω/T at very low magnetic field. This increase of Hall sensitivity is caused by the occurrence of anomalous HE (AHE) after ferromagnetic phase transition. Our work indicates that the magnetic-element-doped TIs with AHE are good candidates for HE sensors.« less

The Magnetar Nature and the Outburst Mechanism of a Transient Anomalous X-ray Pulsar

NASA Technical Reports Server (NTRS)

Guver, Tolga; Ozel, Feryal; Gogus, Ersin; Kouveliotou, Chryssa

2007-01-01

Anomalous X-ray Pulsars (AXPs) belong to a class of neutron stars believed to harbor the strongest magnetic fields in the universe, as indicated by their energetic bursts and their rapid spindowns. However, a direct measurement of their surface field strengths has not been made to date. It is also not known whether AXP outbursts result from changes in the neutron star magnetic field or crust properties. Here we report the first, spectroscopic measurement of the surface magnetic field strength of an AXP, XTE J1810-197, and solidify its magnetar nature. The field strength obtained from detailed spectral analysis and modeling is remarkably close to the value inferred from the rate of spindown of this source and remains nearly constant during numerous observations spanning over two orders of magnitude in source flux. The surface temperature, on the other hand, declines steadily and dramatically following the 2003 outburst of this source. Our findings demonstrate that heating occurs in the upper neutron star crust during an outburst and sheds light on the transient behaviour of AXPs.

Detailed Physical Modeling Reveals the Magnetar Nature of a Transient Anomalous X-ray Pulsar

NASA Technical Reports Server (NTRS)

Guever, T.; Oezel, F.; Goegues, E.; Kouveliotou, C.

2007-01-01

Anomalous X-ray Pulsars (AXPs) belong to a class of neutron stars believed to harbor the strongest magnetic fields in the universe, as indicated by their energetic bursts and their rapid spindowns. However, a direct measurement of their surface field strengths has not been made to date. It is also not known whether AXP outbursts result from changes in the neutron star magnetic field or crust properties. Here we report the first, spectroscopic measurement of the surface magnetic field strength of an AXP, XTE J1810-197, and solidify its magnetar nature. The field strength obtained from detailed spectral analysis and modeling is remarkably close to the value inferred from the rate of spindown of this source and remains nearly constant during numerous observations spanning over two orders of magnitude in source flux. The surface temperature, on the other hand, declines steadily and dramatically following the 2003 outburst of this source. Our findings demonstrate that heating occurs in the upper neutron star crust during an outburst and sheds light on the transient behaviour of AXPs.

Effect of different surface finishing/polishing procedures on color stability of esthetic restorative materials: A spectrophotometric evaluation

PubMed Central

Beltrami, Riccardo; Ceci, Matteo; De Pani, Gabriele; Vialba, Lodovico; Federico, Ricaldone; Poggio, Claudio; Colombo, Marco

2018-01-01

Objective: To evaluate the color stability of different esthetic restorative materials after surface finishing/polishing with different procedures. Materials and Methods: All materials were polymerized into silicone rubber rings to obtain specimens identical in size. Samples were randomly assigned into four groups (10 specimens of each composite for each group), and they were finished with different procedures: Control group (Group 1), three or two polishers interspersed with diamond grit (Groups 3 and 2, respectively), and one tungsten carbide bur + one polisher interspersed with diamond grit (Group 4). After staining process in coffee, a colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, and 28 days. Shapiro–Wilk test and Kruskal–Wallis analysis of variance were applied to assess significant differences among restorative materials. Means of the different polishing/finishing groups were compared with Scheffe's multiple comparison test at the 0.05 level of significance. Results: In control group, significant lower discolorations were recorded for Essentia, Admira Fusion, and Estelite. After finishing, Filtek Supreme XTE and Ceram.X Universal showed a significantly lower degree of staining. The finishing technique used for Group 4 produced higher color changes. Conclusions: Tungsten carbide burs produced the higher color variations; after finishing, the nanofilled composites showed lower discoloration than nanohybrid ones, and the time of exposure to the staining agent and the polishing/finishing technique influenced the color change. PMID:29657525

Bridgman crystal growth

NASA Technical Reports Server (NTRS)

Carlson, Frederick

1990-01-01

The objective of this theoretical research effort was to improve the understanding of the growth of Pb(x)Sn(1-x)Te and especially how crystal quality could be improved utilizing the microgravity environment of space. All theoretical growths are done using the vertical Bridgman method. It is believed that improved single crystal yields can be achieved by systematically identifying and studying system parameters both theoretically and experimentally. A computational model was developed to study and eventually optimize the growth process. The model is primarily concerned with the prediction of the thermal field, although mass transfer in the melt and the state of stress in the crystal were of considerable interest. The evolution is presented of the computer simulation and some of the important results obtained. Diffusion controlled growth was first studied since it represented a relatively simple, but nontheless realistic situation. In fact, results from this analysis prompted a study of the triple junction region where the melt, crystal, and ampoule wall meet. Since microgravity applications were sought because of the low level of fluid movement, the effect of gravitational field strength on the thermal and concentration field was also of interest. A study of the strength of coriolis acceleration on the growth process during space flight was deemed necessary since it would surely produce asymmetries in the flow field if strong enough. Finally, thermosolutal convection in a steady microgravity field for thermally stable conditions and both stable and unstable solutal conditions was simulated.

Growth of CdZnTe Crystals for Radiation Detector Applications by Directional Solidification

NASA Technical Reports Server (NTRS)

Su, Ching-Hua

2014-01-01

Advances in Cadmium Zinc Telluride (Cd(sub 1-x)Zn(sub x)Te) growth techniques are needed for the production of large-scale arrays of gamma and x-ray astronomy. The research objective is to develop crystal growth recipes and techniques to obtain large, high quality CdZnTe single crystal with reduced defects, such as charge trapping, twinning, and tellurium precipitates, which degrade the performance of CdZnTe and, at the same time, to increase the yield of usable material from the CdZnTe ingot. A low gravity material experiment, "Crystal Growth of Ternary Compound Semiconductors in Low Gravity Environment", will be performed in the Material Science Research Rack (MSRR) on International Space Station (ISS). One section of the flight experiment is the melt growth of CdZnTe ternary compounds. This talk will focus on the ground-based studies on the growth of Cd(sub 0.80)Zn(sub 0.20)Te crystals for radiation detector applications by directional solidification. In this investigation, we have improved the properties that are most critical for the detector applications (electrical properties and crystalline quality): a) Electrical resistivity: use high purity starting materials (with reproducible impurity levels) and controlled Cd over pressure during growth to reproducibly balance the impurity levels and Cd vacancy concentration b) Crystalline quality: use ultra-clean growth ampoule (no wetting after growth), optimized thermal profile and ampoule design, as well as a technique for supercool reduction to growth large single crystal with high crystalline quality

Electron Microscope Studies of Cadmium Mercury Telluride

NASA Astrophysics Data System (ADS)

Lyster, Martin

Available from UMI in association with The British Library. Requires signed TDF. Epitaxial layers of Cd_{x }Hg_{(1-x)}Te grown on various substrates by liquid phase epitaxy and metallo-organic vapour phase epitaxy have been studied using transmission and scanning electron microscopy, in a variety of contrast modes. Wavelength-dispersive X-ray microanalysis has been used to study interfaces in epitaxial specimens, and the results are used to derive diffusion coefficients for a range of values of x in Cd_ {x}Hg_{(1-x)} Te. Extensive use has been made of back-scattered electron contrast in the SEM as a means of compositional mapping, and defect structures are imaged by this technique. The back-scattered electron contrast at interfaces has been studied in detail and is modelled using the Monte Carlo approach. The modelling is combined with calculations and practical measurements of the probe size in the SEM instrument used in the work, to arrive at a quantitative explanation of this contrast. The SEM and scintillator detector used allow a spatial resolution of better than 1000A, but it is shown that improvements in this are possible with present technology. Scanning infra-red microscopy (SIRM) and high -resolution transmission electron microscopy (HREM) have been applied to the study of CdTe. SIRM images reveal information about Te precipitation, including particle size and density. HREM images provide results concerning dislocation structures in CdTe. Selected-area diffraction contrast TEM results are presented which illustrate the microstructure of LPE and MOVPE material; and TEM foil preparation techniques are discussed, including the choice of ion species for milling cross-sectional specimens. In view of the results obtained, suggestions are made for future work in this field.

OCT for early quality evaluation of tooth-composite bond in clinical trials.

PubMed

Haak, Rainer; Schmidt, Patrick; Park, Kyung-Jin; Häfer, Matthias; Krause, Felix; Ziebolz, Dirk; Schneider, Hartmut

2018-06-19

To evaluate early quality of composite restorations with a universal adhesive in different application modes clinically and with optical coherence tomography (OCT). 22 patients with four non-carious cervical lesions each received composite restorations (Filtek Supreme TM XTE, 3 M). The universal adhesive Scotchbond Universal TM (SBU, 3 M) was applied with three etching protocols: self-etch (SE), selective-enamel-etch (SEE) and etch-and-rinse (ER). The etch-and-rinse adhesive OptiBond TM FL (OFL, Kerr) served as a control. Restorations were imaged by OCT (Thorlabs) directly after application (t 0 ). After 14 days (t 1 ) and 6 month (t 2 ) OCT imaging (interfacial adhesive defects) was repeated combined with clinical assessment (FDI criteria). Groups were compared by Friedman-/Wilcoxon- and McNemar-Test. No differences were seen clinically between groups (p i ≥ 0.500). OCT assessment revealed more adhesive defects at the enamel interface with SBU/SE at t 0- t 2 compared to all groups (p i ≤ 0.016). OFL showed more defects than SBU/ER (t 1 : p = 0.01; t 2 : p = 0.083). At dentin/cementum interface OFL exhibited more adhesive defects than SBU with all conditioning modes (t 0 , t 1 , p i ≤ 0.003) and at t 2 to SBU/SE and SBU/ER (p < 0.001). Since t 1 defects with SBU were detected more frequently in the SE and SEE modes compared to ER (p i ≤ 0.037). In contrast to SBU defects increased with OFL up to t 2 (p i ≤ 0.007). In contrast to clinical evaluation, OCT revealed subtle adhesive defects directly after application that might interfere with clinical success. It was demonstrated that ER doesn't decrease initial adhesion of SBU to dentin. Copyright © 2018. Published by Elsevier Ltd.

Electronic Band Structure Tuning of Highly-Mismatched-Alloys for Energy Conversion Applications

NASA Astrophysics Data System (ADS)

Ting, Min

Highly-mismatched alloys: ZnO1-xTe x and GaN1-xSb x are discussed within the context of finding the suitable material for a cost-effective Si-based tandem solar cell (SBTSC). SBTSC is an attractive concept for breaking through the energy conversion efficiency theoretical limit of a single junction solar cell. Combining with a material of 1.8 eV band gap, SBTSC can theoretically achieve energy conversion efficiency > 45%. ZnO and GaN are wide band gap semiconductors. Alloying Te in ZnO and alloying Sb in GaN result in large band gap reduction to < 2 eV from 3.3 eV and 3.4 eV respectively. The band gap reduction is majorly achieved by the upward shift of valence band (VB). Incorporating Te in ZnO modifies the VB of ZnO through the valence-band anticrossing (VBAC) interaction between localized Te states and ZnO VB delocalized states, which forms a Te-derived VB at 1 eV above the host VB. Similar band structure modification is resulted from alloying Sb in GaN. Zn1-xTex and GaN 1-xSbx thin films are synthesized across the whole composition range by pulsed laser deposition (PLD) and low temperature molecular beam epitaxy (LT-MBE) respectively. The electronic band edges of these alloys are measured by synchrotron X-ray absorption, emission, and the X-ray photoelectron spectroscopies. Modeling the optical absorption coefficient with the band anticrossing (BAC) model revealed that the Te and Sb defect levels to be at 0.99 eV and 1.2 eV above the VB of ZnO and GaN respectively. Electrically, Zn1-xTex is readily n-type conductive and GaN1-xSbx is strongly p-type conductive. A heterojunction device of p-type GaN 0.93Sb0.07 with n-type ZnO0.77Te0.93 upper cell (band gap at 1.8 eV) on Si bottom cell is proposed as a promising SBTSC device.

Ancient Black Hole Speeds Through Sun's Galactic Neighborhood, Devouring Companion Star

NASA Astrophysics Data System (ADS)

2001-09-01

Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope have found an ancient black hole speeding through the Sun's Galactic neighborhood, devouring a small companion star as the pair travels in an eccentric orbit looping to the outer reaches of our Milky Way Galaxy. The scientists believe the black hole is the remnant of a massive star that lived out its brief life billions of years ago and later was gravitationally kicked from its home star cluster to wander the Galaxy with its companion. "This discovery is the first step toward filling in a missing chapter in the history of our Galaxy," said Felix Mirabel, an astrophysicist at the Institute for Astronomy and Space Physics of Argentina and French Atomic Energy Commission. "We believe that hundreds of thousands of very massive stars formed early in the history of our Galaxy, but this is the first black hole remnant of one of those huge primeval stars that we've found." "This also is the first time that a black hole's motion through space has been measured," Mirabel added. A black hole is a dense concentration of mass with a gravitational pull so strong that not even light can escape it. The research is reported in the Sept. 13 issue of the scientific journal Nature. XTE J1118+480 The object is called XTE J1118+480 and was discovered by the Rossi X-Ray satellite on March 29, 2000. Later observations with optical and radio telescopes showed that it is about 6,000 light-years from Earth and that it is a "microquasar" in which material sucked by the black hole from its companion star forms a hot, spinning disk that spits out "jets" of subatomic particles that emit radio waves. Most of the stars in our Milky Way Galaxy are within a thin disk, called the plane of the Galaxy. However, there also are globular clusters, each containing hundreds of thousands of the oldest stars in the Galaxy which orbit the Galaxy's center in paths that take them far from the Galaxy's plane. XTE J1118+480 orbits the Galaxy's center in a path similar to those of the globular clusters, moving at 145 kilometers per second (90 miles per second) relative to the Earth. How did it get into such an orbit? "There are two possibilities: either it formed in the Galaxy's plane and was somehow kicked out of the plane or it formed in a globular cluster and was kicked out of the cluster," said Vivek Dhawan, an astronomer at the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico. A massive star ends its life by exploding as a supernova, leaving either a neutron star or a black hole as a remnant. Some neutron stars show rapid motion, thought to result from a sideways "kick" during the supernova explosion. "This black hole has much more mass -- about seven times the mass of our Sun -- than any neutron star," said Dhawan. "To accelerate it to its present speed would require a kick from the supernova that we consider improbable," Dhawan added. "We think it's more likely that it was gravitationally ejected from the globular cluster," Dhawan said. Simulations of the gravitational interactions in globular clusters have shown that the black holes resulting from the collapse of the most massive stars should eventually be ejected from the cluster. "The star that preceded this black hole probably formed in a globular cluster even before our Galaxy's disk was formed," Mirabel said. "What we're doing here is the astronomical equivalent of archaeology, seeing traces of the intense burst of star formation that took place during an early stage of our Galaxy's development." The black hole has consumed so much of its companion star that the inner layers of the smaller star -- only about one-third the mass of the Sun -- now are exposed. The scientists believe the black hole captured the companion before being ejected from the globular cluster, as if it were grabbing a snack for the road. The Very Long Baseline Array "Because this microquasar happened to be relatively close to the Earth, we were able to track its motion with the VLBA even though it's normally faint," said Mirabel. "Now, we want to find more of these ancient black holes. There must be hundreds of thousands swirling around in our Galaxy." The astronomers used the VLBA to observe XTE J1118+480 in May and July of 2000, using the VLBA's great resolving power, or ability to see fine detail, to precisely measure the object's movement against the backdrop of more-distant celestial bodies. The VLBA observations were made at radio frequencies of 8.4 and 15.4 GHz. In addition, they found that the object appears in optical images made for the Palomar Observatory Sky Survey (POSS) taken 43 years apart. The POSS images were digitized to allow for rapid search and analysis by the Space Telescope Science Institute. The data from both the radio and optical images allowed the astronomers to calculate the object's orbital path around the Galactic center. "With the VLBA, we could start observing soon after this object was discovered and get extremely precise information on its position. Then, we were able to use the digitized data from the Palomar surveys to extend backward the time span of our information. This is a great example of applying multiple tools of modern astronomy -- telescopes covering different wavelengths and digital databases -- to a single problem," said Dhawan. In addition to Mirabel and Dhawan, the research was performed by Roberto Mignani of the European Southern Observatory; Irapuan Rodrigues, who is a fellow of the Brazilian National Research Council at the French Atomic Energy Commission; and Fabrizia Guglielmetti of the Space Telescope Science Institute in Baltimore, MD. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Charged string loops in Reissner-Nordström black hole background

NASA Astrophysics Data System (ADS)

Oteev, Tursinbay; Kološ, Martin; Stuchlík, Zdeněk

2018-03-01

We study the motion of current carrying charged string loops in the Reissner-Nordström black hole background combining the gravitational and electromagnetic field. Introducing new electromagnetic interaction between central charge and charged string loop makes the string loop equations of motion to be non-integrable even in the flat spacetime limit, but it can be governed by an effective potential even in the black hole background. We classify different types of the string loop trajectories using effective potential approach, and we compare the innermost stable string loop positions with loci of the charged particle innermost stable orbits. We examine string loop small oscillations around minima of the string loop effective potential, and we plot radial profiles of the string loop oscillation frequencies for both the radial and vertical modes. We construct charged string loop quasi-periodic oscillations model and we compare it with observed data from microquasars GRO 1655-40, XTE 1550-564, and GRS 1915+105. We also study the acceleration of current carrying string loops along the vertical axis and the string loop ejection from RN black hole neighbourhood, taking also into account the electromagnetic interaction.

Optical studies of the X-ray transient XTE J2123-058 - II. Phase-resolved spectroscopy

NASA Astrophysics Data System (ADS)

Hynes, R. I.; Charles, P. A.; Haswell, C. A.; Casares, J.; Zurita, C.; Serra-Ricart, M.

2001-06-01

We present time-resolved spectroscopy of the soft X-ray transient XTEJ2123-058 in outburst. A useful spectral coverage of 3700-6700Å was achieved spanning two orbits of the binary, with single-epoch coverage extending to ~9000Å. The optical spectrum approximates a steep blue power law, consistent with emission on the Rayleigh-Jeans tail of a hot blackbody spectrum. The strongest spectral lines are Heii 4686Å and Ciii/Niii 4640Å (Bowen blend) in emission. Their relative strengths suggest that XTEJ2123-058 was formed in the Galactic plane, not in the halo. Other weak emission lines of Heii and Civ are present, and Balmer lines show a complex structure, blended with Heii. Heii 4686-Å profiles show a complex multiple S-wave structure, with the strongest component appearing at low velocities in the lower-left quadrant of a Doppler tomogram. Hα shows transient absorption between phases 0.35 and 0.55. Both of these effects appear to be analogous to similar behaviour in SW Sex type cataclysmic variables. We therefore consider whether the spectral line behaviour of XTEJ2123-058 can be explained by the same models invoked for those systems.

Thermodynamic properties of PbTe, PbSe, and PbS: a first-principles study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yi; Ke, Xuezhi; Chen, Changfeng

2009-01-01

The recent discovery of novel lead chalcogenide-based thermoelectric materials has attracted great interest. These materials exhibit low thermal conductivity which is closely related to their lattice dynamics and thermodynamic properties. In this paper, we report a systematic study of electronic structures and lattice dynamics of the lead chalcogenides PbX (X=Te, Se, S) using first-principles density functional theory calculations and a direct force-constant method. We calculate the struc- tural parameters, elastic moduli, electronic band structures, dielectric constants, and Born effective charges. Moreover, we determine phonon dispersions, phonon density of states, and phonon softening modes in these materials. Based on the resultsmore » of these calculations, we further employ quasihar- monic approximation to calculate the heat capacity, internal energy, and vibrational entropy. The obtained results are in good agreement with experimental data. Lattice thermal conductivities are evaluated in terms of the Gruneisen parameters. The mode Gruneisen parameters are calculated to explain the anharmonicity in these materials. The effect of the spin-orbit interaction is found to be negligible in determining the thermodynamic properties of PbTe, PbSe, and PbS.« less

On the Nature of QPO Phase Lags in Black Hole Candidates

NASA Technical Reports Server (NTRS)

Shaposhnikov, Nikolai

2012-01-01

Observations of quasi-periodic oscillations (QPOs) in X-ray binaries hold a key to understanding many aspects of these enigmatic systems. Complex appearance of the Fourier phase lags related to QPOs is one of the most puzzling observational effects in accreting black holes. In this Letter we show that QPO properties, including phase lags, can be explained in a framework of a simple scenario, where the oscillating media provides a feedback on the emerging spectrum. We demonstrate that the QPO waveform is presented by the product of a perturbation and a time delayed response factors, where the response is energy dependent. The essential property of this effect is its non-linear and multiplicative nature. Our multiplicative reverberation model successfully describes the QPO components in energy dependent power spectra as well as the appearance of the phase lags between signal in different energy bands. We apply our model to QPOs observed by Rossi X-ray Timing Explorer in BH candidate XTE J1550-564. We briefly discuss the implications of the observed energy dependence of the QPO reverberation times and amplitudes to the nature of the power law spectral component and its variability.

A high-velocity black hole on a Galactic-halo orbit in the solar neighbourhood.

PubMed

Mirabel, I F; Dhawan, V; Mignani, R P; Rodrigues, I; Guglielmetti, F

2001-09-13

Only a few of the dozen or so known stellar-mass black holes have been observed away from the plane of the Galaxy. Those few could have been ejected from the plane as a result of a 'kick' received during a supernova explosion, or they could be remnants of the population of massive stars formed in the early stages of evolution of the Galaxy. Determining their orbital motion should help to distinguish between these options. Here we report the transverse motion (in the plane of the sky) for the black-hole X-ray nova XTE J1118+480 (refs 2, 3, 4, 5), from which we derive a large space velocity. This X-ray binary system has an eccentric orbit around the Galactic Centre, like most objects in the halo of the Galaxy, such as ancient stars and globular clusters. The properties of the system suggest that its age is comparable to or greater than the age of the Galactic disk. Only an extraordinary 'kick' from a supernova could have launched the black hole into an orbit like this from a birthplace in the disk of the Galaxy.

Connections Between Jet Formation and Multiwavelength Spectral Evolution in Black Hole Transients

NASA Technical Reports Server (NTRS)

Kakemci, Emrah; Chun, Yoon-Young; Dincer, Tolga; Buxton, Michelle; Tomsick, John A.; Corbel, Stephane; Kaaret, Philip

2011-01-01

Multiwavelength observations are the key to understand conditions of jet formation in Galactic black hole transient (GBHT) systems. By studying radio and optical-infrared evolution of such systems during outburst decays, the compact jet formation can be traced. Comparing this with X-ray spectral and timing evolution we can obtain physical and geometrical conditions for jet formation, and study the contribution of jets to X-ray emission. In this work, first X-ray evolution - jet relation for XTE J1752-223 will be discussed. This source had very good coverage in X-rays, optical, infrared and radio. A long exposure with INTEGRAL also allowed us to study gamma-ray behavior after the jet turns on. We will also show results from the analysis of data from GX 339-4 in the hard state with SUZAKU at low flux levels. The fits to iron line fluorescence emission show that the inner disk radius increases by a factor of greater than 27 with respect to radii in bright states. This result, along with other disk radius measurements in the hard state will be discussed within the context of conditions for launching and sustaining jets.

Role of chemically and thermally induced crystal lattice distortion in enhancing the Seebeck coefficient in complex tellurides

DOE PAGES

Levin, E. M.; Iowa State Univ., Ames, IA; Kramer, M. J.; ...

2016-07-14

Composition and crystal structure of complex materials can significantly change the Seebeck effect, i.e., heat to electrical energy conversion, which is utilized in thermoelectric materials. Despite decades of studies of various thermoelectric materials and their application, the fundamental understanding of this effect still is limited. One of the most efficient groups of thermoelectric materials is based on GeTe, where Ge is replaced by [Ag + Sb], i.e., Ag xSb xGe 50-2xTe 50 alloys, traditionally shown as (GeTe) m(AgSbTe 2) 100-m (TAGS-m series). Here, in this article, we report on the discovery of two unique phenomena in TAGS materials attributed tomore » the effects from [Ag + Sb] atoms: (i) a linear relation between the Seebeck coefficient and rhombohedral lattice distortion, and (ii) resonance-like temperature-induced behavior of the contribution to the Seebeck coefficient produced by [Ag + Sb] atoms. Finally, our findings show that heat to electrical energy conversion strongly depends on the temperature- and compositionally-induced rhombohedral to cubic transformation where [Ag + Sb] atoms play a crucial mediating role.« less

Searching for High-energy, Horizon-scale Emissions from Galactic Black Hole Transients during Quiescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, L. C.-C.; Pu, Hung-Yi; Hirotani, Kouichi

We search for the gamma-ray counterparts of stellar-mass black holes using the long-term Fermi archive to investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon. We achieve this by applying the pulsar outer-gap model to their magnetospheres. When a black hole transient (BHT) is in a low-hard or quiescent state, the radiatively inefficient accretion flow cannot emit enough MeV photons that are required to sustain the force-free magnetosphere in the polar funnel via two-photon collisions. In this charge-starved gap region, an electric field arises along the magnetic field lines to accelerate electrons and positronsmore » into ultra-relativistic energies. These relativistic leptons emit copious Gamma-rays via the curvature and inverse-Compton (IC) processes. It is found that these gamma-ray emissions exhibit a flaring activity when the plasma accretion rate typically stays between 0.01% and 0.005% of the Eddington value for rapidly rotating, stellar-mass black holes. By analyzing the detection limit determined from archival Fermi /Large Area Telescope data, we find that the 7-year averaged duty cycle of such flaring activities should be less than 5% and 10% for XTE J1118+480 and 1A 0620-00, respectively, and that the detection limit is comparable to the theoretical prediction for V404 Cyg. It is predicted that the gap emission can be discriminated from the jet emission if we investigate the high-energy spectral behavior or observe nearby BHTs during deep quiescence simultaneously in infrared wavelength and very-high energies.« less

Six-month color change and water sorption of 9 new-generation flowable composites in 6 staining solutions.

PubMed

Arregui, Maria; Giner, Luis; Ferrari, Marco; Vallés, Marta; Mercadé, Montserrat

2016-11-28

Color match and water sorption are two factors that affect restorative materials. Discoloration is essential in the lifespan of restorations. The aim of this study was to evaluate color change and water sorption of nine flowable composites at multiple time points over 6 months. 60 samples of each composite were divided into two groups (Color Change and Water Sorption/Solubility). Each Color Change group was divided into six subgroups, which were immersed in distilled water (DW), coffee (CF), Coca-Cola (CC), red wine (RW), tea (TE) and orange juice (OJ). The color was measured at the baseline, 1, 2, 3 and 4 weeks, and 3 and 6 months and color change values (ΔE) were calculated. Each Water Sorption [WS]/Solubility [WL] group was tested according to ISO 4049:2009. The data were evaluated using two-way ANOVA, Fisher's post-hoc test and Pearson's correlation test. The composite with the lowest ΔE differed for each solution: Filtek™ Bulk Fill in DW (∆E = 0.73 (0.17-1.759)); Vertise Flow in CF (∆E = 14.75 (7.91-27.41)), in TE (∆E = 7.27 (2.81-24.81)) and OJ (∆E = 3.17 (0.87-9.92)); Tetric EvoFlow® in CC (∆E = 1.27 (0.45-4.02)); and Filtek™ Supreme XTE in RW (∆E = 8.88 (5.23-19.59)). RW caused the most discoloration (∆E = 23.62 (4.93-51.36)). Vertise Flow showed the highest water sorption (WS = 69.10 ± 7.19). The Pearson test showed statistically significant positive correlations between water sorption and solubility and between water sorption and ∆E; the positive solubility-∆E correlation was not statistically significant. The findings suggest that water sorption is one factor associated with the ability of composites to discolor; however, discoloration is a multifactorial problem.

Correlations between the frequencies of twin kHz QPOs and spins of neutron stars in LMXBs

NASA Astrophysics Data System (ADS)

Wang, De-Hua; Zhang, Cheng-Min; Qu, Jin-Lu; Yang, Yi-Yan

2018-02-01

We investigate the correlation between the frequencies of twin kilohertz quasi-periodic oscillations (kHz QPOs) and neutron star (NS) spins in low-mass X-ray binaries (LMXBs), based on the data sets of 12 sources with simultaneously detected twin kHz QPOs and NS spins, and find that the histogram of the ratio between the frequency difference of twin kHz QPOs (Δν ≡ ν2 - ν1) and NS spin νs shows a non-uniform distribution with a gap at Δν/νs ∼ 0.65. We try to classify the 12 sources into two categories according to this gap: (I) slow rotators with 〈νs〉 ∼ 311 Hz, XTE J1807.4-294, 4U 1915-05, IGR J17191-2821, 4U 1702-43, 4U 1728-34 and 4U 0614+09 follow a relation Δν/νs > 0.65; (II) fast rotators with 〈νs〉 ∼ 546 Hz, SAX J1808.4-3658, KS 1731-260, Aql X-1, 4U 1636-53, SAX J1750.8-2900 and 4U 1608-52 satisfy the relation Δν/νs < 0.65. However, the linear fittings of Δν versus νs relations of groups (I) and (II) are unsatisfactory to ensure any certain correlations. We suggest that this phenomenon may arise from the fact that most measured kHz QPOs and spins satisfy the conditions of 1.1 νs ≤ ν2 < 1300 Hz and Δν decreasing with ν2. Apparently, the diversified distribution of Δν/νs refutes the simple beat-frequency model, and the statistical correlations between the twin kHz QPOs and NS spins may arise from the magnetosphere-disc boundary environments, e.g. co-rotation radius and NS radius, that modulate the occurrences of X-ray signals. Furthermore, we also find a distribution of the ratio of ν2 to ν1 clusters around the value of 〈ν2/ν1〉 ∼ 3: 2, which shows no obvious correlation with NS spins.

Sb 121 , 123 nuclear quadrupole resonance as a microscopic probe in the Te-doped correlated semimetal FeSb 2 : Emergence of electronic Griffith phase, magnetism, and metallic behavior

DOE PAGES

Gippius, A. A.; Zhurenko, S. V.; Hu, R.; ...

2018-02-12

121,123Sb nuclear quadrupole resonance (NQR) was applied to Fe(Sb 1-xTe x) 2 in the low doping regime (x = 0 , 0.01, and 0.05) as a microscopic zero field probe to study the evolution of 3d magnetism and the emergence of metallic behavior. Whereas the NQR spectra itself reflects the degree of local disorder via the width of the individual NQR lines, the spin lattice relaxation rate (SLRR) 1/T 1 (T) probes the fluctuations at the Sb site. The fluctuations originate either from conduction electrons or from magnetic moments. In contrast to the semimetal FeSb 2 with a clear signaturemore » of the charge and spin gap formation in 1/T 1(T)T[~exp/(Δk BT)] , the 1% Te-doped system exhibits almost metallic conductivity and the SLRR nicely confirms that the gap is almost filled. A weak divergence of the SLRR coefficient 1/T 1(T)T ~ T -n ~ T -0.2 points towards the presence of electronic correlations towards low temperatures. This is supported by the electronic specific heat coefficient γ = (C el/T) showing a power-law divergence γ (T) ~ T -m ~ (1/T 1T) 1/2 ~ T -n/2 ~ C el/T which is expected in the renormalized Landau Fermi liquid theory for correlated electrons. In contrast to that the 5% Te-doped sample exhibits a much larger divergence in the SLRR coefficient showing 1/T 1(T)T ~ T -0.72 . According to the specific heat divergence a power law with n = 2 m = 0.56 is expected for the SLRR. This dissimilarity originates from admixed critical magnetic fluctuations in the vicinity of antiferromagnetic long range order with 1/T 1(T)T ~ T -3/4 behavior. Furthermore Te-doped FeSb 2 as a disordered paramagnetic metal might be a platform for the electronic Griffith phase scenario. NQR evidences a substantial asymmetric broadening of the 121,123Sb NQR spectrum for the 5% sample. Lastly, this has a predominant electronic origin in agreement with the electronic Griffith phase and stems probably from an enhanced Sb-Te bond polarization and electronic density shift towards the Te atom inside Sb-Te dumbbell.« less

Sb 121 , 123 nuclear quadrupole resonance as a microscopic probe in the Te-doped correlated semimetal FeSb 2 : Emergence of electronic Griffith phase, magnetism, and metallic behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gippius, A. A.; Zhurenko, S. V.; Hu, R.

121,123Sb nuclear quadrupole resonance (NQR) was applied to Fe(Sb 1-xTe x) 2 in the low doping regime (x = 0 , 0.01, and 0.05) as a microscopic zero field probe to study the evolution of 3d magnetism and the emergence of metallic behavior. Whereas the NQR spectra itself reflects the degree of local disorder via the width of the individual NQR lines, the spin lattice relaxation rate (SLRR) 1/T 1 (T) probes the fluctuations at the Sb site. The fluctuations originate either from conduction electrons or from magnetic moments. In contrast to the semimetal FeSb 2 with a clear signaturemore » of the charge and spin gap formation in 1/T 1(T)T[~exp/(Δk BT)] , the 1% Te-doped system exhibits almost metallic conductivity and the SLRR nicely confirms that the gap is almost filled. A weak divergence of the SLRR coefficient 1/T 1(T)T ~ T -n ~ T -0.2 points towards the presence of electronic correlations towards low temperatures. This is supported by the electronic specific heat coefficient γ = (C el/T) showing a power-law divergence γ (T) ~ T -m ~ (1/T 1T) 1/2 ~ T -n/2 ~ C el/T which is expected in the renormalized Landau Fermi liquid theory for correlated electrons. In contrast to that the 5% Te-doped sample exhibits a much larger divergence in the SLRR coefficient showing 1/T 1(T)T ~ T -0.72 . According to the specific heat divergence a power law with n = 2 m = 0.56 is expected for the SLRR. This dissimilarity originates from admixed critical magnetic fluctuations in the vicinity of antiferromagnetic long range order with 1/T 1(T)T ~ T -3/4 behavior. Furthermore Te-doped FeSb 2 as a disordered paramagnetic metal might be a platform for the electronic Griffith phase scenario. NQR evidences a substantial asymmetric broadening of the 121,123Sb NQR spectrum for the 5% sample. Lastly, this has a predominant electronic origin in agreement with the electronic Griffith phase and stems probably from an enhanced Sb-Te bond polarization and electronic density shift towards the Te atom inside Sb-Te dumbbell.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sriram, K.; Rao, A. R.; Choi, C. S., E-mail: astrosriram@yahoo.co.in

The transition of type B/A quasi-periodic oscillations (QPOs) is often associated with a sudden flux change at the peak of the outburst in black hole X-ray binaries. Recent studies show that these variations are connected to the jet ejection phenomenon in the inner regions of the accretion disk. One such event of the black hole source XTE J1550-564 is investigated, where a type A QPO transforms to type B in the first transition. In the second transition, a notable increase in the flux was observed in the 13–60 keV band. The dynamical energy-dependent power density spectrum and broadband energy spectrummore » obtained using the Rossi X-ray Timing Explorer data of this event were inspected to understand the energetics of the inner accretion disk. During these transitions, both disk and corona parameters were found to be varying along with their corresponding fluxes. We discuss the plasma ejection model scenario in the context of the first transition and the condensation of the corona in the inner region for the second transition event. Spectral results were used to derive the critical mass accretion rate, the amount of condensation, and the critical luminosity needed for the condensation process. We found the results to be in well agreement with theoretical simulations.« less

Search for Nonthermal X-Rays from Supernova Remnant Shells

NASA Astrophysics Data System (ADS)

Petre, R.; Keohane, J.; Hwang, U.; Allen, G.; Gotthelf, E.

The demonstration by ASCA that the nonthermal X-ray emission from the rim of SN1006 is synchrotron emission from TeV electrons, produced in the same environment responsible for cosmic ray protons and nuclei (Koyama et al. 1995, Nature 378, 255), has stimulated a search for nonthermal X-rays from other remnants. Nonthermal emission has subsequently been found to arise in the shells of at least two other remnants, Cas A and IC 443. In Cas A, a hard tail is detected using ASCA, XTE, and OSSE to energies exceeding 100 keV; the shape of the spectrum rules out all mechanisms except synchrotron radiation. In IC 443, the previously known hard emission has been shown using ASCA to be isolated to a small region along the rim of the remnant, where the shock is interacting most strongly with a molecular cloud. Nonthermal X-ray emission is thought to arise here by enhanced cosmic ray production associated with the shock/cloud interaction (Keohane et al. 1997, ApJ in press). We describe the properties of the nonthermal emission in SN1006, Cas A, and IC 443, and discuss the status of our search for nonthermal emission associated with the shocks of other Galactic and LMC SNR's.

Relevant optical properties for direct restorative materials.

PubMed

Pecho, Oscar E; Ghinea, Razvan; do Amaral, Erika A Navarro; Cardona, Juan C; Della Bona, Alvaro; Pérez, María M

2016-05-01

To evaluate relevant optical properties of esthetic direct restorative materials focusing on whitened and translucent shades. Enamel (E), body (B), dentin (D), translucent (T) and whitened (Wh) shades for E (WhE) and B (WhB) from a restorative system (Filtek Supreme XTE, 3M ESPE) were evaluated. Samples (1 mm thick) were prepared. Spectral reflectance (R%) and color coordinates (L*, a*, b*, C* and h°) were measured against black and white backgrounds, using a spectroradiometer, in a viewing booth, with CIE D65 illuminant and d/0° geometry. Scattering (S) and absorption (K) coefficients and transmittance (T%) were calculated using Kubelka-Munk's equations. Translucency (TP) and opalescence (OP) parameters and whiteness index (W*) were obtained from differences of CIELAB color coordinates. R%, S, K and T% curves from all shades were compared using VAF (Variance Accounting For) coefficient with Cauchy-Schwarz inequality. Color coordinates and optical parameters were statistically analyzed using one-way ANOVA, Tukey's test with Bonferroni correction (α=0.0007). Spectral behavior of R% and S were different for T shades. In addition, T shades showed the lowest R%, S and K values, as well as the highest T%, TP an OP values. In most cases, WhB shades showed different color and optical properties (including TP and W*) than their corresponding B shades. WhE shades showed similar mean W* values and higher mean T% and TP values than E shades. When using whitened or translucent composites, the final color is influenced not only by the intraoral background but also by the color and optical properties of multilayers used in the esthetic restoration. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Black Hole Mass Determination In the X-Ray Binary 4U 1630-47: Scaling of Spectral and Variability Characteristics

NASA Technical Reports Server (NTRS)

Seifina, Elena; Titarchuk, Lev; Shaposhnikov, Nikolai

2014-01-01

We present the results of a comprehensive investigation on the evolution of spectral and timing properties of the Galactic black hole candidate 4U 1630-47 during its spectral transitions. In particular, we show how a scaling of the correlation of the photon index of the Comptonized spectral component gamma with low-frequency quasi-periodic oscillations (QPOs), ?(sub L), and mass accretion rate, M, can be applied to the black hole mass and the inclination angle estimates.We analyze the transition episodes observed with the Rossi X-Ray Timing Explorer and BeppoSAX satellites.We find that the broadband X-ray energy spectra of 4U 1630-47 during all spectral states can be modeled by a combination of a thermal component, a Comptonized component, and a red-skewed iron-line component. We also establish that gamma monotonically increases during transition from the low-hard state to the high-soft state and then saturates for high mass accretion rates. The index saturation levels vary for different transition episodes. Correlations of gamma versus ?(sub L) also show saturation at gamma (is) approximately 3. Gamma -M and gamma -?(sub L) correlations with their index saturation revealed in 4U 1630-47 are similar to those established in a number of other black hole candidates and can be considered as an observational evidence for the presence of a black hole in these sources. The scaling technique, which relies on XTE J1550-564, GRO 1655-40, and H1743-322 as reference sources, allows us to evaluate a black hole mass in 4U 1630-47 yielding M(sub BH) (is) approximately 10 +/- 0.1 solar masses and to constrain the inclination angle of i (is) approximately less than 70 deg.

Imaging Dirac-mass disorder from magnetic dopant atoms in the ferromagnetic topological insulator Cr x(Bi 0.1Sb 0.9) 2-xTe 3

DOE PAGES

Lee, Inhee; Kim, Chung Koo; Lee, Jinho; ...

2015-01-20

To achieve and use the most exotic electronic phenomena predicted for the surface states of 3D topological insulators (TIs), it is necessary to open a “Dirac-mass gap” in their spectrum by breaking time-reversal symmetry. Use of magnetic dopant atoms to generate a ferromagnetic state is the most widely applied approach. However, it is unknown how the spatial arrangements of the magnetic dopant atoms influence the Dirac-mass gap at the atomic scale or, conversely, whether the ferromagnetic interactions between dopant atoms are influenced by the topological surface states. Here we image the locations of the magnetic (Cr) dopant atoms in themore » ferromagnetic TI Cr₀.₀₈(Bi₀.₁Sb₀.₉)₁.₉₂Te₃. Simultaneous visualization of the Dirac-mass gap Δ(r) reveals its intense disorder, which we demonstrate is directly related to fluctuations in n(r), the Cr atom areal density in the termination layer. We find the relationship of surface-state Fermi wavevectors to the anisotropic structure of Δ(r) not inconsistent with predictions for surface ferromagnetism mediated by those states. Moreover, despite the intense Dirac-mass disorder, the anticipated relationship Δ(r)∝n(r) is confirmed throughout and exhibits an electron–dopant interaction energy J* = 145 meV·nm². In addition, these observations reveal how magnetic dopant atoms actually generate the TI mass gap locally and that, to achieve the novel physics expected of time-reversal symmetry breaking TI materials, control of the resulting Dirac-mass gap disorder will be essential.« less

Transport and first-principles study of novel thermoelectric materials

NASA Astrophysics Data System (ADS)

Chi, Hang

Thermoelectric materials can recover waste industrial heat and convert it to electricity as well as provide efficient local cooling of electronic devices. The efficiency of such environmentally responsible and exceptionally reliable solid state energy conversion is determined by the dimensionless figure-of-merit ZT = alpha2 sigmaT/kappa, where alpha is the Seebeck coefficient, sigma is the electrical conductivity, kappa is the thermal conductivity, and T is the absolute temperature. The goal of the thesis is to (i) illustrate the physics to achieve high ZT of advanced thermoelectric materials and (ii) explore fundamental structure and transport properties in novel condensed matter systems, via an approach combining comprehensive experimental techniques and state-of-the-art first-principles simulation methods. Thermo-galvanomagnetic transport coefficients are derived from Onsager's reciprocal relations and evaluated via solving Boltzmann transport equation using Fermi-Dirac statistics, under the relaxation time approximation. Such understanding provides insights on enhancing ZT through two physically intuitive and very effective routes: (i) improving power factor PF = alpha2sigma; and (ii) reducing thermal conductivity kappa, as demonstrated in the cases of Mg2Si1-xSnx solid solution and Ge/Te double substituted skutterudites CoSb3(1-x)Ge1.5x Te1.5x, respectively. Motivated by recent theoretical predictions of enhanced thermoelectric performance in highly mismatched alloys, ZnTe:N molecular beam epitaxy (MBE) films deposited on GaAs (100) substrates are carefully examined, which leads to a surprising discovery of significant phonon-drag thermopower (reaching 1-2 mV/K-1) at ~13 K. Further systematic study in Bi2Te3 MBE thin films grown on sapphire (0001) and/or BaF2 (111) substrates, reveal that the peak of phonon drag can be tuned by the choice of substrates with different Debye temperatures. Moreover, the detailed transport and structure studies of Bi2-xTl xTe3 single crystals demonstrate that thallium doping leads to a bulk insulating state for such a topological insulator, which opens an avenue for further investigations of transport phenomena related to surface states. Finally, using the combined theoretical and experimental approaches, a new layered transition metal dichalcogenide type of ground state of Cu 2Se is proposed, which exhibits extraordinary weak anti-localization type of magnetoresistance at liquid helium temperatures.

Rapid timing studies of black hole binaries in Optical and X-rays: correlated and non-linear variability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gandhi, P.; Dhillon, V. S.; Durant, M.

2010-07-15

In a fast multi-wavelength timing study of black hole X-ray binaries (BHBs), we have discovered correlated optical and X-ray variability in the low/hard state of two sources: GX 339-4 and SWIFT J1753.5-0127. After XTE J1118+480, these are the only BHBs currently known to show rapid (sub-second) aperiodic optical flickering. Our simultaneous VLT/Ultracam and RXTE data reveal intriguing patterns with characteristic peaks, dips and lags down to very short timescales. Simple linear reprocessing models can be ruled out as the origin of the rapid, aperiodic optical power in both sources. A magnetic energy release model with fast interactions between the disk,more » jet and corona can explain the complex correlation patterns. We also show that in both the optical and X-ray light curves, the absolute source variability r.m.s. amplitude linearly increases with flux, and that the flares have a log-normal distribution. The implication is that variability at both wavelengths is not due to local fluctuations alone, but rather arises as a result of coupling of perturbations over a wide range of radii and timescales. These 'optical and X-ray rms-flux relations' thus provide new constraints to connect the outer and inner parts of the accretion flow, and the jet.« less

Broad-Band Measurements of Cen X-3 With XTE and CGRO

NASA Technical Reports Server (NTRS)

Vestrand, W. Thomas

1999-01-01

Centaurus X-3 has played a key role in the development of our understanding of galactic x-ray binary sources. Timing analysis of the UHURU x-ray observations for the luminous Cen X-3 source (L approximately 10(exp 38) erg/s) revealed the first evidence for coherent x-ray pulsations from an object in a binary system (Giaconni 1971; Schreier 1972). It was quickly understood that the luminous pulsed x-ray emission could be generated by the accretion of matter from a companion star onto a rotating neutron star and led to the adoption of binary star models as the fundamental model for galactic x-ray sources (e.g. Pringle and Rees 1972; Lamb 1973). Based on modeling and refined observations since the original measurements, we now believe that Cen X-3 is a high mass x-ray binary system that contains a disk-fed pulsar with a period of 4.84 seconds that is in a 2.087 day orbit around an O-star companion. Since the pulsar discovery, its period has been intermittently monitored and those studies show a long term spin-up of the pulsar punctuated by short intervals of spin-down (e.g. Finger 1994). The implied torques are thought to originate from the interaction of an accretion disk with the magnetic field of a neutron star (Ghosh and Lamb 1979).

Coordinated XTE Observations of Coronal Structure and Flares on the Rs CVn Binary Sigma(sup 2) CrB

NASA Technical Reports Server (NTRS)

Brown, Alexander

1999-01-01

This NASA grant supported my RXTE observing and data analysis during AO2. The research involved a 100 kilosecond observation of the active RS CVn binary sigma(sup 2) CrB obtained on 1997 March 11-13. This observation covered two orbits of the binary (2.5 days elapsed time) as part of a coordinated satellite and ground-based study of coronal structure and flaring within this system. Simultaneous data was obtained from the ASCA X-ray satellite and the Very Large Array radio telescope. The one month of effort funded for the PI was used to calibrate and analyze the RXTE data. Additional research effort on this project to lead to a final publication has been provided from LTSA and GSRP grants. An initial attempt was made to calibrate the RXTE data in May 1997 but the results were disappointing with poor background subtraction leading to a relatively noisy PCA light curve. Subsequently major improvements have been made in the calibration techniques for low count rate PCA data and we returned to Goddard Space Flight Center in February 1999 when we were able to produce vastly better calibrated data. The RXTE results are currently being integrated with the ASCA and VLA data and a paper should be submitted by the end of summer 1999.

Black hole spin inferred from 3:2 epicyclic resonance model of high-frequency quasi-periodic oscillations

NASA Astrophysics Data System (ADS)

Šrámková, E.; Török, G.; Kotrlová, A.; Bakala, P.; Abramowicz, M. A.; Stuchlík, Z.; Goluchová, K.; Kluźniak, W.

2015-06-01

Estimations of black hole spin in the three Galactic microquasars GRS 1915+105, GRO J1655-40, and XTE J1550-564 have been carried out based on spectral and timing X-ray measurements and various theoretical concepts. Among others, a non-linear resonance between axisymmetric epicyclic oscillation modes of an accretion disc around a Kerr black hole has been considered as a model for the observed high-frequency quasi-periodic oscillations (HF QPOs). Estimates of spin predicted by this model have been derived based on the geodesic approximation of the accreted fluid motion. Here we assume accretion flow described by the model of a pressure-supported torus and carry out related corrections to the mass-spin estimates. We find that for dimensionless black hole spin a ≡ cJ/GM2 ≲ 0.9, the resonant eigenfrequencies are very close to those calculated for the geodesic motion. Their values slightly grow with increasing torus thickness. These findings agree well with results of a previous study carried out in the pseudo-Newtonian approximation. The situation becomes different for a ≳ 0.9, in which case the resonant eigenfrequencies rapidly decrease as the torus thickness increases. We conclude that the assumed non-geodesic effects shift the lower limit of the spin, implied for the three microquasars by the epicyclic model and independently measured masses, from a ~ 0.7 to a ~ 0.6. Their consideration furthermore confirms compatibility of the model with the rapid spin of GRS 1915+105 and provides highly testable predictions of the QPO frequencies. Individual sources with a moderate spin (a ≲ 0.9) should exhibit a smaller spread of the measured 3:2 QPO frequencies than sources with a near-extreme spin (a ~ 1). This should be further examined using the large amount of high-resolution data expected to become available with the next generation of X-ray instruments, such as the proposed Large Observatory for X-ray Timing (LOFT).

Black hole mass determination in the X-ray binary 4U 1630-47: Scaling of spectral and variability characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seifina, Elena; Titarchuk, Lev; Shaposhnikov, Nikolai, E-mail: seif@sai.msu.ru, E-mail: titarchuk@fe.infn.it, E-mail: lev@milkyway.gsfc.nasa.gov, E-mail: nikolai.v.shaposhnikov@nasa.gov

2014-07-01

We present the results of a comprehensive investigation on the evolution of spectral and timing properties of the Galactic black hole candidate 4U 1630-47 during its spectral transitions. In particular, we show how a scaling of the correlation of the photon index of the Comptonized spectral component Γ with low-frequency quasi-periodic oscillations (QPOs), ν {sub L}, and mass accretion rate, M-dot , can be applied to the black hole mass and the inclination angle estimates. We analyze the transition episodes observed with the Rossi X-Ray Timing Explorer and BeppoSAX satellites. We find that the broadband X-ray energy spectra of 4Umore » 1630-47 during all spectral states can be modeled by a combination of a thermal component, a Comptonized component, and a red-skewed iron-line component. We also establish that Γ monotonically increases during transition from the low-hard state to the high-soft state and then saturates for high mass accretion rates. The index saturation levels vary for different transition episodes. Correlations of Γ versus ν {sub L} also show saturation at Γ ∼ 3. Γ-- M-dot and Γ-ν {sub L} correlations with their index saturation revealed in 4U 1630-47 are similar to those established in a number of other black hole candidates and can be considered as an observational evidence for the presence of a black hole in these sources. The scaling technique, which relies on XTE J1550-564, GRO 1655-40, and H1743-322 as reference sources, allows us to evaluate a black hole mass in 4U 1630-47 yielding M {sub BH} ∼ 10 ± 0.1 solar masses and to constrain the inclination angle of i ≲ 70°.« less

Color Stability of New Esthetic Restorative Materials: A Spectrophotometric Analysis

PubMed Central

Vialba, Lodovico; Federico, Ricaldone; Colombo, Marco; Beltrami, Riccardo

2017-01-01

The aim of this in vitro study was to evaluate and compare the color stability of different esthetic restorative materials (one microfilled composite, one nanofilled composite, one nanoceramic composite, one microfilled hybrid composite, one microfilled hybrid composite, one nanohybrid Ormocer based composite and one supra-nano spherical hybrid composite) after exposure to different staining solutions (physiological saline, red wine, coffee). All materials were prepared and polymerized into silicon rings (2 mm × 6 mm × 8 mm) to obtain specimens identical in size. Thirty cylindrical specimens of each material were prepared. Specimens were immersed in staining solutions (physiological saline, coffee and red wine) over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. The Shapiro–Wilk test and ANOVA were applied to assess significant differences among restorative materials. A paired t-test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. All restorative materials showed significant color differences after immersion in coffee. Coffee caused a significant color change in all types of tested composite resins. Only Filtek Supreme XTE demonstrated a staining susceptibility to red wine; no other significant differences among the materials were demonstrated. Long-term exposure to some food dyes (coffee in particular) can significantly affect the color stability of modern esthetic restorative materials regardless of materials’ different compositions. PMID:28684672

FTOOLS: A FITS Data Processing and Analysis Software Package

NASA Astrophysics Data System (ADS)

Blackburn, J. K.

FTOOLS, a highly modular collection of over 110 utilities for processing and analyzing data in the FITS (Flexible Image Transport System) format, has been developed in support of the HEASARC (High Energy Astrophysics Science Archive Research Center) at NASA's Goddard Space Flight Center. Each utility performs a single simple task such as presentation of file contents, extraction of specific rows or columns, appending or merging tables, binning values in a column or selecting subsets of rows based on a boolean expression. Individual utilities can easily be chained together in scripts to achieve more complex operations such as the generation and displaying of spectra or light curves. The collection of utilities provides both generic processing and analysis utilities and utilities specific to high energy astrophysics data sets used for the ASCA, ROSAT, GRO, and XTE missions. A core set of FTOOLS providing support for generic FITS data processing, FITS image analysis and timing analysis can easily be split out of the full software package for users not needing the high energy astrophysics mission utilities. The FTOOLS software package is designed to be both compatible with IRAF and completely stand alone in a UNIX or VMS environment. The user interface is controlled by standard IRAF parameter files. The package is self documenting through the IRAF help facility and a stand alone help task. Software is written in ANSI C and \\fortran to provide portability across most computer systems. The data format dependencies between hardware platforms are isolated through the FITSIO library package.

A Resonantly Excited Disk-Oscillation Model of High-Frequency QPOs of Microquasars

NASA Astrophysics Data System (ADS)

Kato, Shoji

2012-12-01

A possible model of twin high-frequency QPOs (HF QPOs) of microquasars is examined. The disk is assumed to have global magnetic fields and to be deformed with a two-armed pattern. In this deformed disk, a set of a two-armed (m = 2) vertical p-mode oscillation and an axisymmetric (m = 0) g-mode oscillation is considered. They resonantly interact through the disk deformation when their frequencies are the same. This resonant interaction amplifies the set of the above oscillations in the case where these two oscillations have wave energies of opposite signs. These oscillations are assumed to be excited most efficiently in the case where the radial group velocities of these two waves vanish at the same place. The above set of oscillations is not unique, depending on the node number n, of oscillations in the vertical direction. We consider that the basic two sets of oscillations correspond to the twin QPOs. The frequencies of these oscillations depend on the disk parameters, such as the strength of the magnetic fields. For observational mass ranges of GRS 1915+ 105, GRO J1655-40, XTE J1550-564, and HEAO H1743-322, the spins of these sources are estimated. High spins of these sources can be described if the disks have weak poloidal magnetic fields as well as toroidal magnetic fields of moderate strength. In this model the 3:2 frequency ratio of high-frequency QPOs is not related to their excitation, but occurs by chance.

Color Stability of New Esthetic Restorative Materials: A Spectrophotometric Analysis.

PubMed

Poggio, Claudio; Vialba, Lodovico; Berardengo, Anna; Federico, Ricaldone; Colombo, Marco; Beltrami, Riccardo; Scribante, Andrea

2017-07-06

The aim of this in vitro study was to evaluate and compare the color stability of different esthetic restorative materials (one microfilled composite, one nanofilled composite, one nanoceramic composite, one microfilled hybrid composite, one microfilled hybrid composite, one nanohybrid Ormocer based composite and one supra-nano spherical hybrid composite) after exposure to different staining solutions (physiological saline, red wine, coffee). All materials were prepared and polymerized into silicon rings (2 mm × 6 mm × 8 mm) to obtain specimens identical in size. Thirty cylindrical specimens of each material were prepared. Specimens were immersed in staining solutions (physiological saline, coffee and red wine) over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. The Shapiro-Wilk test and ANOVA were applied to assess significant differences among restorative materials. A paired t -test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. All restorative materials showed significant color differences after immersion in coffee. Coffee caused a significant color change in all types of tested composite resins. Only Filtek Supreme XTE demonstrated a staining susceptibility to red wine; no other significant differences among the materials were demonstrated. Long-term exposure to some food dyes (coffee in particular) can significantly affect the color stability of modern esthetic restorative materials regardless of materials' different compositions.

XTE Observations of PSR 1259-63 and a Test of Spin Orbit Coupling in the 4U0115+63 System

NASA Technical Reports Server (NTRS)

Cominsky, Lynn R.

1999-01-01

During this report period, Mallory Roberts went to GSFC to analyze the data from two minor outbursts, which occurred from 4UO115+63. Unfortunately, the outbursts were not of sufficient duration to do a unique orbital determination (which was the scientific goal of the experiment). As this report is being written, 4UO115+63 is undergoing its first major outburst in four years. We are planning on adding our RXTE PCA data to any public ASM or PCA data that is obtained through the duration of this outburst, and combining it with our BATSE data from 1994 and 1995 outbursts in order to learn something about the orbital evolution in this system. We have formed a collaboration with colleagues at MIT who are working on the ASM data for this outburst. Thus, work on the original data will continue, with no further funding, and we are hopeful that some important questions with regard to the orbital timing will finally be resolved. The PSR 1259-63 data were originally analyzed by Barry Giles, who reported that no pulsations or flux were seen from this source near apastron. Recently, a new background model for low-count rate sources has been developed for the PCA. We intend to use this new background model to reanalyze these data to see if we can improve the upper limit to the flux. This work will also continue with no further funding.

Polytypism, polymorphism, and superconductivity in TaSe 2 –xTe x

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Huixia; Xie, Weiwei; Tao, Jing

2015-03-03

Polymorphism in materials often leads to significantly different physical properties - the rutile and anatase polymorphs of TiO₂ are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivitymore » of TaSe₂, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access 2 stable polytypes and 2 stable polymorphs in the TaSe 2-xTe x solid solution, and find that the 3R polytype shows a superconducting transition temperature that is between 6 and 17 times higher than that of the much more commonly found 2H polytype. Thus, the reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of T c on subtle differences in the characteristics of the single layers present, or from a surprising effect of the layer stacking sequence on electronic properties that instead are expected to be dominated by the properties of a single layer in materials of this kind.« less

Faraday Rotation Studies of Indium Antimonide and CADMIUM(1-X) Manganese(x) Telluride

NASA Astrophysics Data System (ADS)

Jimenez Gonzalez, Hector J.

Faraday rotation has been studied in two material systems: narrow-gap InSb and wide-gap Cd_ {1-x}Mn_{x}Te. The measurements were done in the infrared region using high magnetic fields up to 150 kG. The Faraday rotation of n-type InSb has been measured for wavelengths between 8.0 and 13.0 μm at 9 K, using magnetic fields up to 150 kG. Measurements were made on samples with nominal carrier concentrations of 1 times 10^{14 }, 6 times 10 ^{14}, 1 times 10^{15}, and 5 times 10^{15} cm^{-3}. The experimental results have been successfully analyzed in terms of intraband and interband transitions at the Gamma point in the Brillouin zone, using a quantum-mechanical treatment. In this approach, there are three contributions to the Faraday rotation: (a) interband, (b) plasma, and (c) spin contributions. The interband contribution is dominant in the low concentration samples where the plasma and spin contributions, which are due to the free carriers, are small. At high carrier concentrations the spin and plasma contributions are dominant. In the low-magnetic -field regime the interband and plasma contributions are linearly proportional to the magnetic field and become small. This makes the spin contribution the leading contribution to the Faraday rotation at low magnetic fields. The 4 -band k cdot p Pidgeon and Brown model was used to calculate the energy levels and the matrix elements for these transitions. Quantum oscillatory effects were observed at low magnetic field. Cyclotron resonance absorption was observed in all samples for wavelengths _sp{~}{>}16.0 mum. The Faraday rotation of Cd_{1 -x}Mn_{x}Te has been measured for x = 0 to 0.27 at 300 and 77 K for photon energies between 0.1 and 1.5 eV, corresponding to wavelengths of 12.0 and 0.8 mum, respectively. We have developed a multioscillator model for the Faraday rotation using an analytical expression for the refractive index that includes contributions from interband transitions at the Gamma, L, and X points of the Brillouin zone as well as the lattice contribution from optical phonons. The multioscillator model explains the measured behavior of the Verdet constant as a function of photon energy for all the above values of x at both temperatures. This model has also been applied successfully to Faraday rotation data for Cd_ {1-x}Mn_{x}Te and Zn_{1-x}Mn _{x}Te from previous studies. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253 -1690.).

MO-E-17A-09: Has Cancer Risk for Pediatric CT Increased Or Decreased? An Analysis of Cohort Data From 2004-2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brady, S; Kaufman, R

Purpose: To analyze CT radiation dosimetry trends in a pediatric population imaged with modern (2004-2013) CT technology Methods: The institutional review board approved this retrospective review. Two cohorts of pediatric patients that received CT scans for treatment or surveillance for Wilms tumor (n=73) or Neuroblastoma (n=74) from 2004–2013 were included in this study. Patients were scanned during this time period on a GE Ultra (8 slice; 2004–2007), a GE VCT (2008–2011), or a GE VCT-XTe (2011–2013). Each patient's individual or combined chest, abdomen, and pelvic CT exams (n=4138) were loaded onto a PACS workstation (Intelerad, Canada) and measured to calculatemore » their effective diameter and SSDE. Patient SSDE was used to estimate patient organ dosimetry based on previously published data. Patient's organ dosimetry were sorted by gender, weight, age, scan protocol (i.e., chest, abdomen, or pelvis), and CT scanner technology and averaged accordingly to calculate population averaged absolute and effective dose values. Results: Patient radiation dose burden calculated for all genders, weights, and ages decreased at a rate of 0.2 mSv/year (4.2 mGy/year; average organ dose) from 2004–2013; overall levels decreased by 50% from 3.0 mSv (60.0 mGy) to 1.5 mSv (25.9 mGy). Patient dose decreased at equal rates for both male and female, and for individual scan protocols. The greatest dose savings was found for patients between 0–4 years old (65%) followed by 5-9 years old (45%), 10–14 years old (30%), and > 14 years old (21%). Conclusion: Assuming a linear-nothreshold model, there always will be potential risk of cancer induction from CT. However, as demonstrated among these patient populations, effective and organ dose has decreased over the last decade; thus, potential risk of long-term side effects from pediatric CT examinations has also been reduced.« less

Fabrication of Lanthanum Telluride 14-1-11 Zintl High-Temperature Thermoelectric Couple

NASA Technical Reports Server (NTRS)

Ravi, Vilupanur A.; Li, Billy Chun-Yip; Fleurial, Pierre; Star, Kurt

2010-01-01

The development of more efficient thermoelectric couple technology capable of operating with high-grade heat sources up to 1,275 K is key to improving the performance of radioisotope thermoelectric generators. Lanthanum telluride La3-xTe4 and 14-1-11 Zintls (Yb14MnSb11) have been identified as very promising materials. The fabrication of advanced high-temperature thermoelectric couples requires the joining of several dissimilar materials, typically including a number of diffusion bonding and brazing steps, to achieve a device capable of operating at elevated temperatures across a large temperature differential (up to 900 K). A thermoelectric couple typically comprises a heat collector/ exchanger, metallic interconnects on both hot and cold sides, n-type and ptype conductivity thermoelectric elements, and cold-side hardware to connect to the cold-side heat rejection and provide electrical connections. Differences in the physical, mechanical, and chemical properties of the materials that make up the thermoelectric couple, especially differences in the coefficients of thermal expansion (CTE), result in undesirable interfacial stresses that can lead to mechanical failure of the device. The problem is further complicated by the fact that the thermoelectric materials under consideration have large CTE values, are brittle, and cracks can propagate through them with minimal resistance. The inherent challenge of bonding brittle, high-thermal-expansion thermoelectric materials to a hot shoe material that is thick enough to carry the requisite electrical current was overcome. A critical advantage over prior art is that this device was constructed using all diffusion bonds and a minimum number of assembly steps. The fabrication process and the materials used are described in the following steps: (1) Applying a thin refractory metal foil to both sides of lanthanum telluride. To fabricate the n-type leg of the advanced thermoelectric couple, the pre-synthesized lanthanum telluride coupon was diffusion bonded to the metal foil using a thin adhesion layer. (2) Repeating a similar process for the 14-1-11 Zintl p-type leg of the advanced thermoelectric couple. (3) Bonding thick CTE-matched metal plates on the metallized lanthanum telluride and Yb14MnSb11 to form the hot and cold sides of the thermoelectric couple. The calculated conversion efficiency of such an advanced couple would be about 10.5 percent, about 35 percent better than heritage radioisotope thermoelectric technology that relies on Si-Ge alloys. In addition, unlike Si-Ge alloys, these materials can be combined with many other thermoelectric materials optimized for operation at lower temperatures to achieve conversion efficiency in excess of 15 percent (a factor of 2 increase over heritage technology).

Diverse Long-Term Variability of Five Candidate High-Mass X-Ray Binaries from Swift Burst Alert Telescope Observations

NASA Technical Reports Server (NTRS)

Corbet, Robin H. D.; Coley, Joel B.; Krimm, Hans A.

2017-01-01

We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope (SWIFT-BAT). IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 seconds. For AX J1700.2-4220, 54 second-pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090,which was previously proposed to be a Be star system with an orbital period of approximately 30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although theymight be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be starmass donors.

Diverse Long-term Variability of Five Candidate High-mass X-Ray Binaries from Swift Burst Alert Telescope Observations

NASA Astrophysics Data System (ADS)

Corbet, Robin H. D.; Coley, Joel B.; Krimm, Hans A.

2017-09-01

We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ˜30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.

Diverse Long-Term Variability of Five Candidate High-Mass X-ray Binaries from Swift Burst Alert Telescope Observations

NASA Astrophysics Data System (ADS)

Corbet, Robin; Coley, Joel Barry; Krimm, Hans A.

2017-08-01

We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. (2014). AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ˜30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corbet, Robin H. D.; Coley, Joel B.; Krimm, Hans A., E-mail: corbet@umbc.edu

We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton . Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, butmore » this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ∼30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.« less

Polycrystalline-thin-film thermophotovoltaic cells

NASA Astrophysics Data System (ADS)

Dhere, Neelkanth G.

1996-02-01

Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto-electronic (infrared detectors, lasers, and optical communications) technologies. Low bandgaps and larger fluences employed in TPV cells result in very high current densities which make it difficult to collect the current effectively. Techniques for laser and mechanical scribing, integral interconnection, and multi-junction tandem structures which have been fairly well developed for thin-film PV solar cells could be further refined for enhancing the voltages from TPV modules. Thin-film TPV cells may be deposited on metals or back-surface reflectors. Spectral control elements such as indium-tin oxide or tin oxide may be deposited directly on the TPV convertor. It would be possible to reduce the cost of TPV technologies based on single-crystal materials being developed at present to the range of US 2-5 per watt so as to be competitive in small to medium size commercial applications. However, a further cost reduction to the range of US ¢ 35- 1 per watt to reach the more competitive large-scale residential, consumer, and hybrid-electric car markets would be possible only with the polycrystalline-thin film TPV cells.

Solid State Reaction of Thin Metal Films with MERCURY(1-X)CADMIUM(X)TELLURIDE.

NASA Astrophysics Data System (ADS)

Ehsani, Hassan

The solid state reactions of both e-beam evaporation and sputter deposition of thin layers of Cu, Co, and Ni onto CdTe and Hg_{0.8}Cd _{0.2}Te have been investigated using Transmission Electron Microscopy and Auger Electron Spectroscopy. For a Cu overlayer deposited by either method on CdTe(111) and Hg_{0.8}Cd _{0.2}Te substrates, we observed formation of a relatively thick region of Cu _{rm 2-x}Te (superlattice structure), even though the heat of reactions ( DeltaH_{rm R} ) are positive as calculated using bulk parameters. Deposition of Co onto Hg_{0.8 }Cd_{0.2}Te substrates reacted to form the gamma -phase (Co_3Te_4) at room temperature in the case of deposition by sputtering, and at 150^circC annealing temperature in the case of deposition by e-beam evaporation. This compound was stable at room and elevated temperatures (100 ^circC, 200^ circC, 300^circC, and 400^circC). On the other hand Co did not react with CdTe (at temperature less than 300^circC) instead, generation of Te was observed. The Te generated in the case of sputter deposition and fast deposition (8-10A) e-beam evaporation was polycrystalline whereas, in the case of slow deposition (0.3-0.5A) e-beam evaporation it was amorphous. Auger depth profile indicated that the amount of excess Te in the case of sputter deposition was larger in compared with deposition by e-beam evaporation. The excess Te was distributed throughout the Co film. The results of Ni deposited onto Hg_ {0.8}Cd_{0.2} Te or CdTe substrate were somewhat similar to the Co cases. Ni reacted with Hg_{0.8 }Cd_{0.2}Te at room temperature in either deposition system to form the delta-phase (NiTe-Ni _2Te). From the results of this work it is clear that the solid produced as a result of either e-beam or sputter deposition has a higher free energy than that of a metal layer on contact with the substrate. This result indicates importance of kinetics in the formation of the interface structure of metals deposited on Hg_{0.8 }Cd_{0.2}Te substrates. (Abstract shortened with permission of author.).

DNA Conjugation and DNA Directed Self-Assembly of Quantum Dots for Nanophotonic Applications

NASA Astrophysics Data System (ADS)

Samanta, Anirban

Colloidal quantum dots (QDs) or semiconductor nanocrystals are often used to describe 2--20 nm solution processed nanoparticles of various semiconductor materials that display quantum confinement effects. Compared to traditional fluorescent organic dyes, QDs provide many advantages. For biological applications it is necessary to develop reliable methods to functionalize QDs with hydrophilic biomolecules so that they may maintain their stability and functionality in physiological conditions. DNA, a molecule that encodes genetic information, is arguably the smartest molecule that nature has ever produced and one of the most explored bio-macromolecules. QDs that are functionalized with DNA can potentially be organized with nanometer precision by DNA directed self-assembly, and the resulting arrangements may facilitate the display of novel optical properties. The goal of this dissertation was to achieve a robust reliable yet simple strategy to link DNA to QDs so that they can be used for DNA directed self assembly by which we can engineer their optical properties. Presented here is a series of studies to achieve this goal. First we demonstrate the aqueous synthesis of colloidal nanocrystal heterostructures consisting of the CdTe core encapsulated by CdS/ZnS or CdSe/ZnS shells using glutathione (GSH), a tripeptide, as the capping ligand. We next employed this shell synthesis strategy to conjugate PS-PO chimeric DNA to QDs at the time of shell synthesis. We synthesized a library of DNA linked QDs emitting from UV to near IR that are very stable in high salt concentrations. These DNA functionalized QDs were further site-specifically organized on DNA origami in desired patterns directed by DNA self-assembly. We further extended our capability to functionalize DNA to real IR emitting CdxPb 1-xTe alloyed QDs, and demonstrated their stability by self-assembling them on DNA origami. The photo-physical properties of the QDs were further engineered by attaching a QD and a gold nanoparticle in controlled distances on the same DNA origami, which revealed a much longer range quenching effect than usual Forster Resonance Energy Transfer. We are currently engaged in enhancing the photoluminescence intensity of the QDs by bringing them in the plasmonic hot spots generated by a cluster of larger plasmonic nanoparticles.

Radiation transport around Kerr black holes

NASA Astrophysics Data System (ADS)

Schnittman, Jeremy David

This Thesis describes the basic framework of a relativistic ray-tracing code for analyzing accretion processes around Kerr black holes. We begin in Chapter 1 with a brief historical summary of the major advances in black hole astrophysics over the past few decades. In Chapter 2 we present a detailed description of the ray-tracing code, which can be used to calculate the transfer function between the plane of the accretion disk and the detector plane, an important tool for modeling relativistically broadened emission lines. Observations from the Rossi X-Ray Timing Explorer have shown the existence of high frequency quasi-periodic oscillations (HFQPOs) in a number of black hole binary systems. In Chapter 3, we employ a simple "hot spot" model to explain the position and amplitude of these HFQPO peaks. The power spectrum of the periodic X-ray light curve consists of multiple peaks located at integral combinations of the black hole coordinate frequencies, with the relative amplitude of each peak determined by the orbital inclination, eccentricity, and hot spot arc length. In Chapter 4, we introduce additional features to the model to explain the broadening of the QPO peaks as well as the damping of higher frequency harmonics in the power spectrum. The complete model is used to fit the power spectra observed in XTE J1550-564, giving confidence limits on each of the model parameters. In Chapter 5 we present a description of the structure of a relativistic alpha- disk around a Kerr black hole. Given the surface temperature of the disk, the observed spectrum is calculated using the transfer function mentioned above. The features of this modified thermal spectrum may be used to infer the physical properties of the accretion disk and the central black hole. In Chapter 6 we develop a Monte Carlo code to calculate the detailed propagation of photons from a hot spot emitter scattering through a corona surrounding the black hole. The coronal scattering has two major observable effects: the inverse-Compton process alters the photon spectrum by adding a high energy power-law tail, and the random scattering of each photon effectively damps out the highest frequency modulations in the X-ray light curve. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617- 253-5668; Fax 617-253-1690.)

In-Situ Grown P-N Junctions in MERCURY(1-X) Cadmium(x) Telluride for IR Detectors.

NASA Astrophysics Data System (ADS)

Rao, Vithal Rajaram

In-situ grown p-n junctions in mercury cadmium telluride (Hg_{1-x}Cd _{x}Te with x between 0.2-0.3) were fabricated and characterized in this study. Fabrication of these junctions involved the growth of p-n structures at 370^circC on CdTe substrates by Organometallic Vapor Phase Epitaxy. P-type doping with arsenic was achieved by using tertiarybutylarsine as the precursor. N-type doping was obtained either with indium, using trimethylindium as the precursor or by leaving the layer undoped. These p-n structures were processed to fabricate photodiodes. Their electrical performance was evaluated and conclusions regarding current mechanisms which determine their behavior were drawn. By varying the Hg pressure between 0.07-0.13 atm, p-type doping level in the 10^{16 }/cm^3-rm2times10 ^{17}/cm^3 range was achieved. At higher values of Hg pressure, the arsenic doping level in the layer increased significantly. This is possibly due to an increase in Te vacancies, allowing arsenic to occupy more group VI sites where they behave as acceptors. The activation efficiency of arsenic in the layers was measured to be equal to 50%. A high temperature anneal at 415 ^circC for 15 minutes did not result in any increase in the activation efficiency, possibly indicating the presence of stable As-complexes in the layer. Growth of p^+n structures was carried out in a single run. The acceptor concentration in the p-type cap layer was 5-rm10times10 ^{16}/cm^3. Indium doped n-type base layers had a carrier concentration of 1- rm2times10^{16}/cm^3 , while undoped layers had a n-type background carrier concentration of 4-rm6times10^ {14}/cm^3. The cap layer was 3 μm thick with x = 0.30, while the base layer was 8mum thick with x = 0.26. Under the growth conditions, arsenic showed a diffusion coefficient of rm2times10 ^{13}cm^2/s, which was higher than the interdiffusion coefficient of the alloy junction. This resulted in placement of the p-n junction in the lower bandgap base layer, which is necessary for high quantum efficiency devices. Photodiodes showed a cutoff wavelength of 7.5 mum, which correlates with the alloy composition of the base layer. Measured R_0 A of these diodes varied between 1-100 ohm-cm ^2. In the lower R_0A diodes, reverse bias was dominated by surface currents, possibly due to degradation of the passivating layer. Diodes with higher R_0A showed under reverse bias that trap assisted tunneling current dominated their performance. The origin of these traps is process related and could correspond to the presence of inactivated arsenic close to the p-n junction. Forward bias was dominated by diffusion and recombination currents, while the presence of additional leakage currents was evident.

Atelier d'astronomie X

NASA Astrophysics Data System (ADS)

Ballet, J.; Barret, D.

2001-01-01

L'astronomie X connait aujourd'hui une de ses périodes les plus actives et les plus fastes, après le lancement de Chandra et XMM-Newton, et alors que Beppo SAX et Rossi XTE sont toujours en orbite. L'extraordinaire complémentarité de ces satellites est telle que leur domaine d'utilisation est extrêmement vaste, couvrant des étoiles jeunes aux toujours énigmatiques sursauts γ, en passant bien entendu par les trous noirs accrétants dans les binaires X ou dans les noyaux actifs de galaxies. L'atelier fut organisé selon quatre thèmes les étoiles, les phénomènes explosifs, les binaires X et les noyaux actifs de galaxies. Les résultats qui y furent présentés, pour chacun de ces thèmes témoignent de la superbe qualité des données obtenues. En particulier l'accès à la haute résolution spectrale (réseaux) en rayons X marque un pas important. Les présentations plus théoriques ont montré que parallèlement des progrès significatifs sont réalisés dans la physique de l'accrétion autour des objets compacts. Les actes de l'atelier donnent un panorama représentatif des progrès réalisés récemment par l'astronomie X, aussi bien du point de vue observationnel que théorique. Ces actes de colloque sont aussi l'occasion de rappeler l'historique et ce que furent les activités scientifiques de notre GdR au moment ou il doit s'intègrer au GdR PCHE et au PNPS. Enfin, pour toutes informations complémentaires concernant l'atelier: http://www.cesr.fr/~barret/adj/vg.html Ce site donne accès en particulier à la plupart des présentations (transparents).

Evidence of Black Hole Spin in GX 339-4: XMM-Newton/EPIC-pn and RXTE Spectroscopy of the Very High State

NASA Astrophysics Data System (ADS)

Miller, J. M.; Fabian, A. C.; Reynolds, C. S.; Nowak, M. A.; Homan, J.; Freyberg, M. J.; Ehle, M.; Belloni, T.; Wijnands, R.; van der Klis, M.; Charles, P. A.; Lewin, W. H. G.

2004-05-01

We have analyzed spectra of the Galactic black hole GX 339-4 obtained through simultaneous 76 ks XMM-Newton/EPIC-pn and 10 ks Rossi X-Ray Timing Explorer observations during a bright phase of its 2002-2003 outburst. An extremely skewed, relativistic Fe Kα emission line and ionized disk reflection spectrum are revealed in these spectra. Self-consistent models for the Fe Kα emission-line profile and disk reflection spectrum rule out an inner disk radius compatible with a Schwarzschild black hole at more than the 8 σ level of confidence. The best-fit inner disk radius of (2-3)rg suggests that GX 339-4 harbors a black hole with a>=0.8-0.9 (where rg=GM/c2 and a=cJ/GM2, and assuming that reflection in the plunging region is relatively small). This confirms indications for black hole spin based on a Chandra spectrum obtained later in the outburst. The emission line and reflection spectrum also rule out a standard power-law disk emissivity in GX 339-4 a broken power-law form with enhanced emissivity inside ~6rg gives improved fits at more than the 8 σ level of confidence. The extreme red wing of the line and the steep emissivity require a centrally concentrated source of hard X-rays that can strongly illuminate the inner disk. Hard X-ray emission from the base of a jet-enhanced by gravitational light-bending effects-could create the concentrated hard X-ray emission; this process may be related to magnetic connections between the black hole and the inner disk. We discuss these results within the context of recent results from analyses of XTE J1650-500 and MCG -6-30-15, and of models for the inner accretion flow environment around black holes.

New constraint on scalar Gauss-Bonnet gravity and a possible explanation for the excess of the orbital decay rate in a low-mass x-ray binary

NASA Astrophysics Data System (ADS)

Yagi, Kent

2012-10-01

It was recently shown that a black hole (BH) is the only compact object that can acquire a scalar charge in scalar Gauss-Bonnet (sGB) theory under the small coupling approximation. This leads to the fact that scalar radiation is emitted from a binary containing at least one BH. In this paper, we find the constraints on this theory from BH low-mass x-ray binaries. The main result of this paper is that from the orbital decay rate of A0620-00, we obtained a conservative bound that is six orders of magnitude stronger than the Solar System bound. In addition to this, we look at XTE J1118+480, whose orbital decay rate has been recently measured with an excess compared to the theoretical prediction in general relativity due to the radiation reaction. The cause of this excess is currently unknown. Although it is likely that the cause is of astrophysical origin, here we investigate the possibility of explaining this excess with the additional scalar radiation in sGB theory. We find that there still remains a parameter range where the excess can be explained while also satisfying the constraint obtained from A0620-00. The interesting point is that for most of other alternative theories of gravity, it seems difficult to explain this excess with the additional radiation. This is because it would be difficult to evade the constraints from binary pulsars or they have already been constrained rather strongly from other observations such as solar system experiments. We propose several ways to determine whether the excess is caused by the scalar radiation in sGB gravity including future gravitational wave observations with space-borne interferometers, which can give a constraint three orders of magnitude stronger than that from A0620-00.

Repetitive patterns in rapid optical variations in the nearby black-hole binary V404 Cygni.

PubMed

Kimura, Mariko; Isogai, Keisuke; Kato, Taichi; Ueda, Yoshihiro; Nakahira, Satoshi; Shidatsu, Megumi; Enoto, Teruaki; Hori, Takafumi; Nogami, Daisaku; Littlefield, Colin; Ishioka, Ryoko; Chen, Ying-Tung; King, Sun-Kun; Wen, Chih-Yi; Wang, Shiang-Yu; Lehner, Matthew J; Schwamb, Megan E; Wang, Jen-Hung; Zhang, Zhi-Wei; Alcock, Charles; Axelrod, Tim; Bianco, Federica B; Byun, Yong-Ik; Chen, Wen-Ping; Cook, Kem H; Kim, Dae-Won; Lee, Typhoon; Marshall, Stuart L; Pavlenko, Elena P; Antonyuk, Oksana I; Antonyuk, Kirill A; Pit, Nikolai V; Sosnovskij, Aleksei A; Babina, Julia V; Baklanov, Aleksei V; Pozanenko, Alexei S; Mazaeva, Elena D; Schmalz, Sergei E; Reva, Inna V; Belan, Sergei P; Inasaridze, Raguli Ya; Tungalag, Namkhai; Volnova, Alina A; Molotov, Igor E; de Miguel, Enrique; Kasai, Kiyoshi; Stein, William L; Dubovsky, Pavol A; Kiyota, Seiichiro; Miller, Ian; Richmond, Michael; Goff, William; Andreev, Maksim V; Takahashi, Hiromitsu; Kojiguchi, Naoto; Sugiura, Yuki; Takeda, Nao; Yamada, Eiji; Matsumoto, Katsura; James, Nick; Pickard, Roger D; Tordai, Tamás; Maeda, Yutaka; Ruiz, Javier; Miyashita, Atsushi; Cook, Lewis M; Imada, Akira; Uemura, Makoto

2016-01-07

How black holes accrete surrounding matter is a fundamental yet unsolved question in astrophysics. It is generally believed that matter is absorbed into black holes via accretion disks, the state of which depends primarily on the mass-accretion rate. When this rate approaches the critical rate (the Eddington limit), thermal instability is supposed to occur in the inner disk, causing repetitive patterns of large-amplitude X-ray variability (oscillations) on timescales of minutes to hours. In fact, such oscillations have been observed only in sources with a high mass-accretion rate, such as GRS 1915+105 (refs 2, 3). These large-amplitude, relatively slow timescale, phenomena are thought to have physical origins distinct from those of X-ray or optical variations with small amplitudes and fast timescales (less than about 10 seconds) often observed in other black-hole binaries-for example, XTE J1118+480 (ref. 4) and GX 339-4 (ref. 5). Here we report an extensive multi-colour optical photometric data set of V404 Cygni, an X-ray transient source containing a black hole of nine solar masses (and a companion star) at a distance of 2.4 kiloparsecs (ref. 8). Our data show that optical oscillations on timescales of 100 seconds to 2.5 hours can occur at mass-accretion rates more than ten times lower than previously thought. This suggests that the accretion rate is not the critical parameter for inducing inner-disk instabilities. Instead, we propose that a long orbital period is a key condition for these large-amplitude oscillations, because the outer part of the large disk in binaries with long orbital periods will have surface densities too low to maintain sustained mass accretion to the inner part of the disk. The lack of sustained accretion--not the actual rate--would then be the critical factor causing large-amplitude oscillations in long-period systems.

Effect of the Graded-Gap Layer Composition on the Formation of n + -n - -p Structures in Boron-Implanted Heteroepitaxial Cd x Hg1- x Te Layers

NASA Astrophysics Data System (ADS)

Talipov, N. Kh.; Voitsekhovskii, А. V.; Grigor'ev, D. V.

2014-07-01

Processes of formation of n + -n--p-structures in boron-implanted heteroepitaxial (HEL) CdxHg1-xTe (CMT) layers of p-type grown by molecular beam epitaxy (HEL CMT MBE) with different compositions of the upper graded-gap layer are studied. It is shown that the surface composition (xs) of HEL CMT MBE significantly affects both the electrical parameters of the implanted layer and the spatial distribution of radiation defects of donor type. For HEL CMT MBE with the small surface composition xs = 0.22-0.33, it is found that the layer electron concentration (Ns) is decreased after saturation with accumulation of radiation defects, as the dose of B+ ions is increased in the range of D = 1ṡ1011-3ṡ1015 сm-2. An increase of the surface composition up to xs = 0.49-0.56 results in a significant decrease in Ns and a disappearance of the saturation of concentration in the whole dose range. The value of Ns monotonically increases with the energy (E) of boron ions and composition xs. It is found that for B+-ion energies E = 20-100 keV, the depth of the surface n + -layer increases with increasing energy and exceeds the total projected path of boron ions. However, in the energy range E = 100-150 keV, the depth of n+-layer stops increasing with the increase of the surface composition. The depth (dn) of a lightly doped n--layer monotonically decreases with increasing energy of boron ions in the entire range of E = 20-150 keV. With increasing dose (D) of B+ ions in the interval D = 1ṡ1014-1ṡ1015сm-2, deep n--layers with dn = 4-5 μm are formed only in the HEL CMT MBE with xs = 0.22-0.33. For the samples with xs = 0.49-0.56, the depth changes in the interval dn = 1.5-2.5 μm. At D ≤ 3ṡ1013сm-2, n + -n--p-structure is not formed for all surface compositions, if implantation is performed at room temperature. However, implantation at T = 130°C leads to the formation of a deep n--layer. Planar photodiodes with the n-p-junction area of A = 35×35 μm2 made on the basis of the boron implanted HEL CMT MBE with the surface compositions xs = 0.33-0.56 had high differential resistance Rd = 3ṡ106-107 Ω•cm2 and high product R0 Aeff = 9.0-20.7 Ω•cm2, where Aeff is the effective area of the charge carrier collecting. The values of Rd and R0 Aeff increased with increasing xs. It is found that the layer electron concentration in the boron implanted HEL CMT MBE with different surface compositions is increased, when exposed to normal conditions for a few years.

"Iron-Clad" Evidence For Spinning Black Hole

NASA Astrophysics Data System (ADS)

2003-09-01

Telltale X-rays from iron may reveal if black holes are spinning or not, according to astronomers using NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory. The gas flows and bizarre gravitational effects observed near stellar black holes are similar to those seen around supermassive black holes. Stellar black holes, in effect, are convenient `scale models' of their much larger cousins. Black holes come in at least two different sizes. Stellar black holes are between five and 20 times the mass of the Sun. At the other end of the size scale, supermassive black holes contain millions or billions times the mass of our Sun. The Milky Way contains both a supermassive black hole at its center, as well as a number of stellar black holes sprinkled throughout the Galaxy. At a press conference at the "Four Years of Chandra" symposium in Huntsville, Ala., Jon Miller of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. discussed recent results on the X-ray spectra, or distribution of X-rays with energy, from the iron atoms in gas around three stellar black holes in the Milky Way. "Discovering the high degree of correspondence between stellar and supermassive black holes is a real breakthrough," said Miller. "Because stellar black holes are smaller, everything happens about a million times faster, so they can be used as a test-bed for theories of how spinning black holes affect the space and matter around them." X-rays from a stellar black hole are produced when gas from a nearby companion star is heated to tens of millions of degrees as it swirls toward the black hole. Iron atoms in this gas produce distinctive X-ray signals that can be used to study the orbits of particles around the black hole. For example, the gravity of a black hole can shift the X-rays to lower energies. "The latest work provides the most precise measurements yet of the X-ray spectra for stellar black holes," said Miller. "These data help rule out competing explanations that do not require extreme gravitational effects, and provide the best look yet at the geometry of the space-time around a stellar black hole created by the death of a massive star." The orbit of a particle near a black hole depends on the curvature of space around the black hole, which also depends on how fast the black hole is spinning. A spinning black hole drags space around with it and allows atoms to orbit closer to the black hole than is possible for a non-spinning black hole. The latest Chandra data from Cygnus X-1, the first stellar-size black hole discovered, show that the gravitational effects on the signal from the iron atoms can only be due to relativistic effects, and that some of the atoms are no closer than 100 miles to the black hole. There was no evidence that the Cygnus X-1 black hole is spinning. The XMM-Newton data from the black hole, XTE J1650-500, show a very similar distribution of iron atom X-rays with one important exception. More low energy X-rays from iron atoms are observed, an indication that some X-rays are coming from deep in the gravitational well around the black hole, as close as 20 miles to the black hole event horizon. This black hole must be spinning rapidly. Chandra observations of a third stellar black hole, GX 339-4, have revealed that it is also spinning rapidly, and clouds of warm absorbing gas appear to be flowing away from the black hole at speeds of about three hundred thousand miles per hour. Such warm gas flows have been observed in the vicinity of supermassive black holes. Previous observations of some supermassive black holes by Japan's ASCA satellite, XMM-Newton and Chandra have indicated that they may also be rotating rapidly. The latest results presented by Miller indicate that the peculiar geometry of space around spinning stellar-mass black holes and supermassive black holes is remarkably similar. Stellar and supermassive black holes may be similar in other ways. Powerful jets of high-energy particles have been detected around both types of black holes. Why do some stellar black holes spin rapidly and others not? One possibility is that differences in spin are imparted at birth when a massive star collapses. Another possibility is that the spin rate depends on how long the black hole has been devouring matter from its companion star, a process that makes the black hole spin faster. Black holes with more rapid spin, XTE J1650-500 and GX 339-4, have low-mass companion stars. These relatively long-lived stars may have been feeding the black hole for longer, allowing it to spin up to faster rates. Cygnus X-1 with its short-lived companion star may not have not time to spin up. Miller is a National Science Foundation Astronomy & Astrophysics Postdoctoral Fellow. His primary collaborators in this work were Walter Lewin if the Massachusetts Institute of Technology in Cambridge, Andrew Fabian of the University of Cambridge, UK, and Chris Reynolds of the University of Maryland, College Park. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Superficial roughness on composite surface, composite enamel and composite dentin junctions after different finishing and polishing procedures. Part I: roughness after treatments with tungsten carbide vs diamond burs.

PubMed

Ferraris, Federico; Conti, Alessandro

2014-01-01

The aim of this study is to investigate different instruments for finishing composite restorations, as well as examining different surfaces and interfaces of the same restoration. The null hypothesis is represented by the fact that there are no significant differences on roughness of composite restorations finishing between tungsten carbide and diamond burs, furthermore the null hypothesis is that there are no significant differences on roughness between finishing on composite surfaces (C), compositeenamel (CE) and composite-dentin (CD) interfaces. The study was performed on 28 teeth, and class V cavities were prepared on the extracted teeth. Restorations were done in Filtek XTE nanofilled composite (3M Espe) in a standardized method, to then be finished. A comparison was made in the phase 1 between tungsten carbide burs (16 blades), diamond burs (46 μm), with a similar shape by the same manufacturer (Komet). Each surface received 5 bur applications. Consequently, an analysis with a profilometer was performed. Phase 2 involved further confrontation of ulterior finishing with ultrafine tungsten carbide burs (30 blades) and with extra and ultrafine diamond burs (25 and 8 μm) (the same shape as previously mentioned). A second analysis was then performed with a profilometer. All measurements were taken on C surfaces, CE and CD interfaces. Statistical analyses were carried out with c2 test (a = 0.05). The finishing procedures with fine grit or toothing burs gave a better smoothness with tungsten carbide burs compared to diamond burs. While with the ultrafine grit no significant differences were noted between tungsten carbide and diamond burs on the CE and CD interfaces, the diamond bur left less superficial roughness on the C surfaces. With regards to the superficial roughness of the different areas of restoration, it can be concluded that: minor roughness was detected on C surfaces, while the CD interface had the most superficial roughness, regardless of whether the diamond burs or tungsten carbide burs were used. This study shows some statistical differences that could not be clinically perceivable. The clinical relevance could be resumed as follows: the fine tungsten carbide burs provided less roughness compared to a fine diamond bur. There were no differences between the ultrafine tungsten carbide and diamond burs. The less favourable interface to be finished is CD, compared to the CE interface and C surfaces.

Effects of Shocks on Emission from Central Engines of Active Galactic Nuclei. I

NASA Technical Reports Server (NTRS)

Sivron, R.; Caditz, D.; Tsuruta, S.

1996-01-01

In this paper we show that perturbations of the accretion flow within the central engines of some active galactic nuclei (AGNS) are likely to form shock waves in the accreting plasma. Such shocks, which may be either collisional or collisionless, can contribute to the observed high-energy temporal and spectral variability. Our rationale is the following: Observations show that the continuum emission probably originates in an optically thin, hot plasma in the AGN central engine. The flux and spectrum from this hot plasma varies significantly over light crossing timescales. Several authors have suggested that macroscopic perturbations contained within this plasma are the sources of this variability. In order to produce the observed emission the perturbations must be radiatively coupled with the optically thin hot matter and must also move with high velocities. We suggest that shocks, which can be very effective in randomizing the bulk motion of the perturbations, are responsible for this coupling. Shocks should form in the central engine, because the temperatures and magnetic fields are probably reduced below their virial values by radiative dissipation. Perturbations moving at Keplerian speeds, or strong non-linear excitations, result in supersonic and super-Alfvenic velocities leading to shock waves within the hot plasma. We show that even a perturbation smaller than the emitting region can form a shock that significantly modifies the continuum emission in an AGN, and that the spectral and temporal variability from such a shock generally resembles those of radio-quiet AGNS. As an example, the shock inducing perturbation in our model is a small main-sequence star, the capturing and eventual accretion of which are known to be a plausible process. We argue that shocks in the central engine may also provide a natural triggering mechanism for the "cold" component of Guilbert & Rees two-phase medium and an efficient mecha- nism for angular momentum transfer. Current and future missions, such as ASCA, XTE, XMM, AXAF, and ASTRO-E may determine the importance of shock-related emission from the central engines of AGNS.

Superficial roughness on composite surface, composite-enamel and composite-dentin junctions after different finishing and polishing procedures. Part II: roughness with diamond finishing and differences between enamel composite vs body composite.

PubMed

Ferraris, Federico; Conti, Alessandro

2014-01-01

The following study asks three principle questions relative to composite finishing and composite polishing: 1) Will the superficial roughness of different restoration surfaces have different values, utilizing the same polishing system (multistep), after finishing with the tungsten carbide or diamond bur? 2) Under the same conditions of finishing and polishing sequences, will the composite surfaces (C), the composite-enamel (CE) and composite-dentin (CD) interfaces show different roughness values? 3) Will the surface roughness of composites of different translucency in the various phases of finishing and polishing, and on different interfaces, have different results? The null hypothesis is represented by the fact that there are no significant differences on roughness of composite restorations when polishing, after finishing with tungsten carbide or diamond burs. Furthermore, the null hypothesis is that there are no significant differences on roughness between polishing on composite surface, composite-enamel and composite-dentin interfaces, and finally there are no differences on roughness after finishing and polishing of two composite with different translucency. For the study, 56 class V cavities were prepared on extracted teeth. Restorations were done in nanofilled composite Filtek XTE (3M Espe) in a standard fashion, and then finished and polished. The 28 buccal cavities were restored on the surface with composite enamel and the 28 palatals with composite body. Finishing was done with fine toothing burs in tungsten carbide (16 blades) or fine grit diamond burs (46 μm), and made by the same manufacturer (Komet). The second phase of finishing was done with burs (with the same form as already mentioned) ultrafine toothing tungsten carbide (30 blades) or with extra and ultrafine grit diamond (25 and 8 μm). The polishing phase for both of the earlier sequences was done with the application of three rubber tips with decreasing abrasiveness and an application with a self-polishing brush. All measurements were taken from surfaces C, and interfaces CE and CD. Statistical analyses were carried out with c2 test (a = 0.05). 1) There were no relevant differences of surface roughness on the different surfaces if the polishing was done after finishing with tungsten carbide or diamond burs. 2) Keeping the same sequence of finishing and polishing, a difference was noticed between C, CE and CD, where the latter showed greater roughness. 3) Analyzing the data in all the phases of finishing and polishing on every interface, it can be concluded that the composite enamel and the composite body did not show different levels of superficial roughness. The clinical relevance could be resumed as follows: no difference after polishing, which is preceded by tungsten carbide or diamond finishing burs. The less favorable interface to be polished is CD, compared to CE and C. Considering two composites with different translucency, no difference on roughness after finishing and polishing were detected.

Soft X-ray characterisation of the long-term properties of supergiant fast X-ray transients

NASA Astrophysics Data System (ADS)

Romano, P.; Ducci, L.; Mangano, V.; Esposito, P.; Bozzo, E.; Vercellone, S.

2014-08-01

Context. Supergiant fast X-ray transients (SFXTs) are high mass X-ray binaries (HMXBs) that are characterised by a hard X-ray (≥ 15 keV) flaring behaviour. These flares reach peak luminosities of 1036-1037 erg s-1 and last a few hours in the hard X-rays. Aims: We investigate the long-term properties of SFXTs by examining the soft (0.3-10 keV) X-ray emission of the three least active SFXTs in the hard X-ray and by comparing them with the remainder of the SFXT sample. Methods: We performed the first high-sensitivity soft X-ray long-term monitoring with Swift/XRT of three relatively unexplored SFXTs, IGR J08408-4503, IGR J16328-4726, and IGR J16465-4507, whose hard X-ray duty cycles are the lowest measured among the SFXT sample. We assessed how long each source spends in each flux state and compared their properties with those of the prototypical SFXTs. Results: The behaviour of IGR J08408-4503 and IGR J16328-4726 resembles that of other SFXTs, and it is characterised by a relatively high inactivity duty cycle (IDC) and pronounced dynamic range (DR) in the X-ray luminosity. We found DR ~ 7400, IDC ~ 67% for IGR J08408-4503, and DR ~ 750, IDC ~ 61% for IGR J16328-4726 (in all cases the IDC is given with respect to the limiting flux sensitivity of XRT, that is 1-3 × 10-12 erg cm-2 s-1). In common with all the most extreme SFXT prototypes (IGR J17544-2619, XTE J1739-302, and IGR J16479-4514), IGR J08408-4503 shows two distinct flare populations. The first one is associated with the brightest outbursts (X-ray luminosity LX ≳ 1035 - 36 erg s-1), while the second comprises dimmer events with typical luminosities of LX ≲ 1035 erg s-1. This double-peaked distribution of the flares as a function of the X-ray luminosity seems to be a ubiquitous feature of the extreme SFXTs. The lower DR of IGR J16328-4726 suggests that this is an intermediate SFXT. IGR J16465-4507 is characterised by a low IDC ~ 5% and a relatively narrow DR ~ 40, reminiscent of classical supergiant HMXBs. The duty cycles measured with XRT are found to be comparable with those reported previously by BAT and INTEGRAL, when the higher limiting sensitivities of these instruments are taken into account and sufficiently long observational campaigns are available. By making use of these new results and those we reported previously, we prove that no clear correlation exists between the duty cycles of the SFXTs and their orbital periods. Conclusions: The unique sensitivity and scheduling flexibility of Swift/XRT allowed us to carry out an efficient long-term monitoring of the SFXTs, following their activity across more than 4 orders of magnitude in X-ray luminosity. While it is not possible to exclude that particular distributions of the clump and wind parameters may produce double-peaked differential distributions in the X-ray luminosities of the SFXTs, the lack of a clear correlation between the duty cycles and orbital periods of these sources make it difficult to interpret their peculiar variability by only using arguments related to the properties of supergiant star winds. Our findings favour the idea that a correct interpretation of the SFXT phenomenology requires a mechanism to strongly reduce the mass accretion rate onto the compact object during most of its orbit around the companion, as proposed in a number of theoretical works. Tables 1-4 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/568/A55

Long-Term Space Astrophysics Program

NASA Technical Reports Server (NTRS)

Nowark, Michael A.

2001-01-01

This is the final report for our Long-Term Space Astrophysics Program (NRA 94-OSS-12) grant NAG 5-3225. The proposal is entitled 'Spectral and Temporal Properties of Black Hole Candidates', and began funding in May 1995, and ran through 31 Aug 2000. The project summary from the original proposal was as follows: 'We will study the spectral and temporal properties of black hole candidates (BHC) by using data from archival sources (e.g., EXOSAT, Ginga, ROSAT) and proposed follow-up observations with modern instruments (e.g., ASCA, XTE). Our spectral studies will focus on identifying the basic characteristics and luminosities of the emission components in the various 'states' of BHC. We hope to understand and quantify the global energetics of these states. Our temporal studies will focus on expanding and classifying our knowledge of BHC variability properties in each state. We will explore the nature of quasi-periodic oscillations in BHC. We will combine our spectral and temporal studies by analyzing time lags and variability coherence between energy channels. In addition, we will investigate ways of correlating observed variability behavior with specific emission components.' We have accomplished many of these goals laid out within the original proposal. As originally proposed, we have utilized both archival and proprietary satellite data. In terms of archival data, we have utilized data from the Advanced Satellite for Cosmology and Astrophysics (ASCA), ROSAT, and the Rossi X-ray Timing Explorer (RXTE). We also obtained proprietary data from ASCA, RXTE, and the Extreme Ultraviolet Explorer (EUVE). In terms of sources, we have examined a wide variety of both galactic black hole candidates and extra-galactic black holes. For the galactic black holes we have observed and analyzed both the low/hard state and the high/soft state. We have performed both spectral and timing analyses on all of these objects. In addition, we have also examined a number of neutron stars or potential neutron stars. All of our research on the above mentioned objects has resulted in one or more publications in peer-reviewed journals. Attached is a list of refereed publications of research results which have been funded by this grant over approximately the past five and a half years. In addition, we have included a list of conference proceedings and other similar reports that have been associated with this grant.

Magnetic jets from accretion disks : field structure and X-ray emission

NASA Astrophysics Data System (ADS)

Memola, Elisabetta

2002-06-01

Jets are highly collimated flows of matter. They are present in a large variety of astrophysical sources: young stars, stellar mass black holes (microquasars), galaxies with an active nucleus (AGN) and presumably also intense flashes of gamma-rays. In particular, the jets of microquasars, powered by accretion disks, are probably small-scale versions of the outflows from AGN. Beside observations of astrophysical jet sources, also theoretical considerations have shown that magnetic fields play an important role in jet formation, acceleration and collimation. Collimated jets seem to be systematically associated with the presence of an accretion disk around a star or a collapsed object. If the central object is a black hole, the surrounding accretion disk is the only possible location for a magnetic field generation. We are interested in the formation process of highly relativistic jets as observed from microquasars and AGN. We theoretically investigate the jet collimation region, whose physical dimensions are extremely tiny even compared to radio telescopes spatial resolution. Thus, for most of the jet sources, global theoretical models are, at the moment, the only possibility to gain information about the physical processes in the innermost jet region. For the first time, we determine the global two-dimensional field structure of stationary, axisymmetric, relativistic, strongly magnetized (force-free) jets collimating into an asymptotically cylindrical jet (taken as boundary condition) and anchored into a differentially rotating accretion disk. This approach allows for a direct connection between the accretion disk and the asymptotic collimated jet. Therefore, assuming that the foot points of the field lines are rotating with Keplerian speed, we are able to achieve a direct scaling of the jet magnetosphere in terms of the size of the central object. We find a close compatibility between the results of our model and radio observations of the M87 galaxy innermost jet. We also calculate the X-ray emission in the energy range 0.2--10.1,keV from a microquasar relativistic jet close to its source of 5 solar masses. In order to do it, we apply the jet flow parameters (densities, velocities, temperatures of each volume element along the collimating jet) derived in the literature from the relativistic magnetohydrodynamic equations. We obtain theoretical thermal X-ray spectra of the innermost jet as composition of the spectral contributions of the single volume elements along the jet. Since relativistic effects as Doppler shift and Doppler boosting due to the motion of jets toward us might be important, we investigate how the spectra are affected by them considering different inclinations of the line of sight to the jet axis. Emission lines of highly ionized iron are clearly visible in our spectra, probably also observed in the Galactic microquasars GRS 1915+105 and XTE J1748-288. The Doppler shift of the emission lines is always evident. Due to the chosen geometry of the magnetohydrodynamic jet, the inner X-ray emitting part is not yet collimated. Ergo, depending on the viewing angle, the Doppler boosting does not play a major role in the total spectra. This is the first time that X-ray spectra have been calculated from the numerical solution of a magnetohydrodynamic jet. Astrophysikalische Jets sind stark kollimierte Materieströmungen hoher Geschwindigkeit. Sie stehen im Zusammenhang mit einer Fülle verschiedener astrophysikalischer Objekte wie jungen Sternen, stellaren schwarzen Löchern ('Mikro-Quasare'), Galaxien mit aktivem Kern (AGN) und wahrscheinlich auch mit dem beobachteten intensiven Aufblitzen von Gamma-Strahlung (Gamma Ray Bursts). Insbesondere hat sich gezeigt, dass die Jets der Mikro-Quasare wahrscheinlich als kleinskalige Version der Jets der AGN anzusehen sind. Neben den Beobachtungen haben vor allem auch theoretische Überlegungen gezeigt, dass Magnetfelder bei der Jetentstehung, -beschleunigung und -kollimation eine wichtige Rolle spielen. Weiterhin scheinen Jets systematisch verknüpft zu sein mit dem Vorhandensein einer Akkretionsscheibe um das zentrale Objekt. Insbesondere wenn ein schwarzes Loch den Zentralkörper darstellt, ist die umgebende Akkretionsscheibe der einzig mögliche Ort um Magnetfeld erzeugen zu können. Wir sind speziell interessiert am Entstehungsprozess hoch relativistischer Jets wie sie bei Mikro-Quasaren und AGN beobachtet werden. Insbesondere untersuchen wir die Region, in der der Jet kollimiert, eine Region, deren räumliche Ausdehnung extrem klein ist selbst im Vergleich zur Auflösung der Radioteleskope. Dies ist ein Grund, wieso zum heutigen Zeitpunkt für die meisten Quellen die theoretische Modellierung die einzige Möglichkeit darstellt, um Information über die physikalischen Prozesse in der innersten Region der Jetentstehung zu erhalten. Uns ist es zum ersten Mal gelungen, die globale zwei-dimensionale Magnetfeldstruktur stationärer, axialsymmetrischer, relativistischer und stark magnetisierter (kräfte-freier) Jets zu berechnen, die zum einen asymptotisch in einen zylindrischen Jet kollimieren, zum anderen aber in einer differential rotierenden Akkretionsscheibe verankert sind. Damit erlaubt dieser Ansatz eine physikalische Verkn¨upfung zwischen Akkretionsscheibe und dem asymptotischen Jet. Nimmt man also an, dass die Fupunkte der Magnetfeldlinien mit Keplergeschwindigkeit rotieren, so kann man eine direkte Skalierung der Jetmagnetosphere mit der Gröe des Zentralobjektes erhalten. Unsere Resultate zeigen eine gute Übereinstimmung zwischen unserem Modell und Beobachtungen des Jets von M87. Für das Beispiel eines relativistischen Mikroquasarjets haben wir die Röntgenemission im Bereich von 0.2-10.1 keV berechnet. Dafür haben wir in der Literatur aus den relativistischen magnetohydrodynamischen Gleichungen berechnete Jetgröen (Dichte-, Geschwindigkeits-, und Temperaturprofil) verwendet und das Spektrum für jeden Punkt entlang der Jetströmung abgeleitet. Das theoretische thermische Röntgenspektrum des innersten, heien Teils des Jets erhalten wir zusammengesetzt aus den spektralen Anteilen der einzelnen Volumenelemente entlang des Jets. Um relativistische Effekte wie Dopplerverschiebung und -verstärkung (boosting) aufgrund der Jetbewegung zu untersuchen, haben wir für verschiedene Inklinationswinkel des Jets zur Sichtlinie berechnet, wie die erhaltenen Spektren davon beeinflusst werden. Unsere Spektren zeigen deutlich die hochionisierten Eisen-Emissionslinien, die in den galaktischen Mikroquasaren GRS 1915+105 und XTE J1748-288 andeutungsweise beobachtet wurden. Eine Dopplerverschiebung dieser Linien ist in unseren Spektren deutlichzu sehen. Da die innerste, Röntgenstrahlung emittierende Region des magnetohydrodynamischen Jets allerdings noch unkollimiert ist, spielt Dopplerboosting in unseren Spektren, abhängig vom Sichtwinkel, keine groe Rolle. Mit unseren Resultaten konnte zum ersten Mal ein Röntgenspektrum gewonnen werden, das auf der numerischen Lösung eines magnetohydrodynamischen Jets beruht.

High energy variability of 3C 273 during the AGILE multiwavelength campaign of December 2007-January 2008

NASA Astrophysics Data System (ADS)

Pacciani, L.; Donnarumma, I.; Vittorini, V.; D'Ammando, F.; Fiocchi, M. T.; Impiombato, D.; Stratta, G.; Verrecchia, F.; Bulgarelli, A.; Chen, A. W.; Giuliani, A.; Longo, F.; Pucella, G.; Vercellone, S.; Tavani, M.; Argan, A.; Barbiellini, G.; Boffelli, F.; Caraveo, P. A.; Cattaneo, P. W.; Cocco, V.; Costa, E.; Del Monte, E.; Di Cocco, G.; Evangelista, Y.; Feroci, M.; Froysland, T.; Fuschino, F.; Galli, M.; Gianotti, F.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Marisaldi, M.; Mereghetti, S.; Morselli, A.; Pellizzoni, A.; Perotti, F.; Picozza, P.; Prest, M.; Rapisarda, M.; Soffitta, P.; Trifoglio, M.; Tosti, G.; Trois, A.; Vallazza, E.; Zanello, D.; Antonelli, L. A.; Colafrancesco, S.; Cutini, S.; Gasparrini, D.; Giommi, P.; Pittori, C.; Salotti, L.

2009-01-01

Context: We report the results of a 3-week multi-wavelength campaign targeting the flat spectrum radio quasar 3C 273 carried out with the AGILE gamma-ray mission, covering the 30 MeV-50 GeV and 18-60 keV, the REM observatory (covering the near-IR and optical), Swift (near-UV/Optical, 0.2-10 keV and 15-50 keV), INTEGRAL (3-200 keV) and Rossi XTE (2-12 keV). This is the first observational campaign including gamma-ray data, after the last EGRET observations, more than 8 years ago. Aims: This campaign has been organized by the AGILE team with the aim of observing, studying and modelling the broad band energy spectrum of the source, and its variability on a week timescale, testing the emission models describing the spectral energy distribution of this source. Methods: Our study was carried out using simultaneous light curves of the source flux from all the involved instruments, in the different energy ranges, to search for correlated variability. Then a time-resolved spectral energy distribution was used for a detailed physical modelling of the emission mechanisms. Results: The source was detected in gamma-rays only in the second week of our campaign, with a flux comparable to the level detected by EGRET in June 1991. We found an indication of a possible anti-correlation between the emission at gamma-rays and at soft and hard X-rays, supported by the complete set of instruments. Instead, optical data do not show short term variability, as expected for this source. Only in two preceding EGRET observations (in 1993 and 1997) 3C 273 showed intra-observation variability in gamma-rays. In the 1997 observation, flux variation in gamma-rays was associated with a synchrotron flare. The energy-density spectrum with almost simultaneous data partially covers the regions of synchrotron emission, the big blue bump, and the inverse-Compton. We adopted a leptonic model to explain the hard X/gamma-ray emissions, although from our analysis hadronic models cannot be ruled out. In the adopted model, the soft X-ray emission is consistent with combined synchrotron-self Compton and external Compton mechanisms, while hard X and gamma-ray emissions are compatible with external Compton from thermal photons of the disk. Under this model, the time evolution of the spectral energy distribution is well interpreted and modelled in terms of an acceleration episode of the electron population, leading to a shift in the inverse Compton peak towards higher energies.

Continuous and rapid synthesis of nanoclusters and nanocrystals using scalable microstructured reactors

NASA Astrophysics Data System (ADS)

Jin, Hyung Dae

Recent advances in nanocrystalline materials production are expected to impact the development of next generation low-cost and/or high efficiency solar cells. For example, semiconductor nanocrystal inks are used to lower the fabrication cost of the absorber layers of the solar cells. In addition, some quantum confined nanocrystals display electron-hole pair generation phenomena with greater than 100% quantum yield, called multiple exciton generation (MEG). These quantum dots could potentially be used to fabricate solar cells that exceed the Schockley-Queisser limit. At present, continuous syntheses of nanoparticles using microreactors have been reported by several groups. Microreactors have several advantages over conventional batch synthesis. One advantage is their efficient heat transfer and mass transport. Another advantage is the drastic reduction in the reaction time, in many cases, down to minutes from hours. Shorter reaction time not only provides higher throughput but also provide better particle size control by avoiding aggregation and by reducing probability of oxidizing precursors. In this work, room temperature synthesis of Au11 nanoclusters and high temperature synthesis of chalcogenide nanocrystals were demonstrated using continuous flow microreactors with high throughputs. A high rate production of phosphine-stabilized Au11 nanoclusters was achieved using a layer-up strategy which involves the use of microlamination architectures; the patterning and bonding of thin layers of material (laminae) to create a multilayered micromixer in the range of 25-250 mum thick was used to step up the production of phosphine-stabilized Au11 nanoclusters. Continuous production of highly monodispersed phosphine-stabilized Au 11 nanoclusters at a rate of about 11.8 [mg/s] was achieved using a microreactor with a size of 1.687cm3. This result is about 30,000 times over conventional batch synthesis according to production rate/per reactor volume. We have elucidated the formation mechanism of CuInSe2 nanocrystals for the development of a continuous flow process for their synthesis. It was found that copper-rich CuInSe2 with a sphalerite structure was formed initially followed by the formation of more ordered CuInSe2 at longer reaction times, along with the formation of Cu2Se and In2Se3. It was found that Cu2Se was formed at a much faster rate than In2Se3 under the same reaction conditions. By adjusting the Cu/In precursor ratio, we were able to develop a very rapid and simple synthesis of CuInSe2 nanocrystals using a continuous flow microreactor with a high throughput per reactor volume. The microreactor has a simple design which uses readily available low cost components. It comprised an inner microtube to precisely control the injection of TOPSe into a larger diameter tube that preheated CuCl and InCl3 hot mixture was pumped through. Rapid injection plays an important role in dividing the nucleation and growth process which is crucial in getting narrow size distribution. The design of this microreactor also has the advantages of alleviating sticking of QDs on the growth channel wall since QDs were formed from the center of the reactor. Furthermore, size-controlled synthesis of CuInSe2 nanocrystals was achieved using this reactor simply by adjusting ratio between coordinating solvents. Semiconductors with a direct bandgap between 1 and 2eV including Cu(In,Ga)Se 2 (1.04--1.6eV) and CuIn(Se,S)2 (1.04--1.53eV) are ideal for single junction cells utilize the visible spectrum. However, half of the solar energy available to the Earth lies in the infrared region. Inorganic QD-based solar cells with a decent efficiency near 1.5 mum have been reported. Therefore, syntheses of narrow gap IV-VI (SnTe, PbS, PbSe, PbTe), II-IV (HgTe, CdXHg1-XTe), and III-V (InAs) QDs have attracted significant attention and these materials have potential uses for a variety of other optical, electronic, and optoelectronic applications. SnTe with an energy gap of 0.18eV at 300K can be used for IR photodetectors, laser diodes, and thermophotovoltaic energy converters. First continuous synthesis of shape-controlled SnTe nanocrystals were also accomplished in this work. SnCl2, and TOPTe were used as reactants successfully in coordinating OA and TOP solvents. Both rod shape and dot shape SnTe nanocrystals with uniform size distributions could be obtained. A blue shift was observed from these SnTe nanocrystals. Production rate at about 5mg/min (300mg/hr) was achieved using a microreactor at a size of 1.78cm3.

Spatially Resolved Spectroscopy of the SNR IC443

NASA Astrophysics Data System (ADS)

Gorenstein, P.

1998-07-01

IC 443 is a supernova remnant of intermediate age, i.e. a few thousand years. It is especially interesting because part of its periphery is expanding into a molecular cloud while other sections are expanding into a typical interstellar medium of much lower density. Since the evolution of a supernova remnant through its various phases is affected by the density of the medium it expands into with the reasonable assumption that the supernova explosion was approximately symmetric we have an opportunity to observe a single object in two phases simultaneously. It was observed by ASCA in April, 1993 for a short period during the PV phase and more thoroughly in a 42 ksec exposure in March, 1994. The latter measurement provides most of the results that have been reported. Most of the analysis took place after the grant ended but is included here for completeness. The data was sent simultaneously to US and Japanese Pls. We worked independently. The software set of FTOOLs was used to construct images and spectra. They were judged to be rather unintuitive and not at all user friendly. I found I was using one FTOOL to read the header to obtain information that would only be provided to another FTOOL. The Japanese investigators were more successful. They analyzed the data and published results more rapidly. The scientific results summarized below are based primarily on their publications. Since IC 443 is an interesting example of a middle aged SNR in which a variety of processes are occurring it is one of a class. IC 443 exhibits shell-like emission in hard X-rays and extended soft X-rays with thin thermal spectra. It resembles SN 1006 in these respects. IC 443 contains hard X-rays in a semi-circular shell surrounding the thermal component. The total hard X-ray flux in the ASCA FOV is only a half of the Ginga hard component; which suggests that the hard X-rays are not confined only in the shell but some are extended larger than the ASCA FOV of eq 1 degree diameter. Japanese investigators examined the spatial structure of the thermal component and analyzed the GIS spectra with a non-equilibrium plasma model, and found no systematic variation of the interstellar absorption across the remnant. Evidence for shock acceleration of cosmic rays to high energies (10 TeV) was found by Keohane. X-ray imaging spectroscopy with ASCA reveals two regions of particularly hard emission: an unresolved source embedded in an extended emission region, and a ridge of emission coincident with the southeastern rim. Both features are located on part of the radio shell where the shock wave is interacting with molecular gas, and together they account for a majority of the emission at 7 keV. Though we would not have noticed it a priori, the unresolved feature is coincident with one resolved by the ROSAT HRI. The ASCA measurements were combined with higher energy data from the XTE and GRO missions and with radio and TeV gamma-ray data to produce a nonthermal multiwavelength spectrum for IC 443 which was fit with a cosmic ray interaction model. This model calculates the cynchrotron, bremsstrahlung, invers Compton, and neutral pion decay emission produced by locally accelerated cosmic ray interacting with ambient matter, soft photon fields, and magnetic fields.

Spatially Resolved Spectroscopy of the SNR IC443

NASA Technical Reports Server (NTRS)

Gorenstein, P.

1998-01-01

IC 443 is a supernova remnant of intermediate age, i.e. a few thousand years. It is especially interesting because part of its periphery is expanding into a molecular cloud while other sections are expanding into a typical interstellar medium of much lower density. Since the evolution of a supernova remnant through its various phases is affected by the density of the medium it expands into with the reasonable assumption that the supernova explosion was approximately symmetric we have an opportunity to observe a single object in two phases simultaneously. It was observed by ASCA in April, 1993 for a short period during the PV phase and more thoroughly in a 42 ksec exposure in March, 1994. The latter measurement provides most of the results that have been reported. Most of the analysis took place after the grant ended but is included here for completeness. The data was sent simultaneously to US and Japanese Pls. We worked independently. The software set of FTOOLs was used to construct images and spectra. They were judged to be rather unintuitive and not at all user friendly. I found I was using one FTOOL to read the header to obtain information that would only be provided to another FTOOL. The Japanese investigators were more successful. They analyzed the data and published results more rapidly. The scientific results summarized below are based primarily on their publications. Since IC 443 is an interesting example of a middle aged SNR in which a variety of processes are occurring it is one of a class. IC 443 exhibits shell-like emission in hard X-rays and extended soft X-rays with thin thermal spectra. It resembles SN 1006 in these respects. IC 443 contains hard X-rays in a semi-circular shell surrounding the thermal component. The total hard X-ray flux in the ASCA FOV is only a half of the Ginga hard component; which suggests that the hard X-rays are not confined only in the shell but some are extended larger than the ASCA FOV of eq 1 degree diameter. Japanese investigators examined the spatial structure of the thermal component and analyzed the GIS spectra with a non-equilibrium plasma model, and found no systematic variation of the interstellar absorption across the remnant. Evidence for shock acceleration of cosmic rays to high energies (10 TeV) was found by Keohane. X-ray imaging spectroscopy with ASCA reveals two regions of particularly hard emission: an unresolved source embedded in an extended emission region, and a ridge of emission coincident with the southeastern rim. Both features are located on part of the radio shell where the shock wave is interacting with molecular gas, and together they account for a majority of the emission at 7 keV. Though we would not have noticed it a priori, the unresolved feature is coincident with one resolved by the ROSAT HRI. The ASCA measurements were combined with higher energy data from the XTE and GRO missions and with radio and TeV gamma-ray data to produce a nonthermal multiwavelength spectrum for IC 443 which was fit with a cosmic ray interaction model. This model calculates the cynchrotron, bremsstrahlung, invers Compton, and neutral pion decay emission produced by locally accelerated cosmic ray interacting with ambient matter, soft photon fields, and magnetic fields.

Study Techniques for Controlling Flavor Intensity in Compressed Foods. Phase 1

DTIC Science & Technology

1973-01-01

sweet --- 1 - - -- sour (vinegar) 2 1-2 1-2 1-2 tomato 1-2 1-2 1-2 1-2 pork - i-2 1-2 1-2 cayenne pepper 1 1 )H-1 1 catsup spice 1 1-2 1-2 1-2 onion...1 1 1 Sour 2 1-2 1-2 1 3 Tomato 1-2 ) (-1 1-2 1-2 1-2 Pork - )(-1 1-2 1 - Cayenne Pepper 1 - ) (-1 - - Catsup Spice 1 1-2 1-2 1-2 2 Onion - - )(-i 1...Pork 1-2 1-2 1-2 1 - Cayenne Pepper 1 - 71 - - Catsup Spice 1-2 1-2 1-2 1-2 1 Onion - - ) H-i Salt )(-1 1 )( )(-1 1 Cardboard 1 )(-1 )( 1 - Red Pepper

IUE's treasure-chest of the ultraviolet Universe

NASA Astrophysics Data System (ADS)

1997-11-01

IUE was the most long-lived and (by a wide margin) the most productive satellite so far, in the history of space astronomy. After going into orbit on 26 January 1978, as a NASA-ESA-UK project, IUE was meant to operate for three years. More than eighteen years later, IUE still worked 24 hours a day, harvesting new knowledge for astronomers. The last observations were made from ESA's ground station at Villafranca, Spain, on 26 September 1996, and IUE was switched off four days later. Since then, team members at Villafranca and at NASAs Goddard Space Flight Center have used modern data-processing and information technology to recycle 100,000 ultraviolet spectra of comets, planets, stars, galaxies and quasars, acquired by IUE during its 18.5 years of operations. As a result, the IUE Final Archive is already available on-line via the Internet to hundreds of users who have registered to work with the data. The last few items (about 2 per cent of the total) will be added before the end of November. Also to be presented at the Sevilla conference is ESA's system called INES ("IUE Newly Extracted Spectra") which offers access, selection and distribution of data products, in a thoroughly user-friendly fashion. The IUE Final Archive is the third massive compendium made available to the worlds astronomers by ESA in 1997. The Hipparcos and Tycho Catalogues, released earlier in the year, give the positions of stars with unprecedented accuracy, thanks to ESA's Hipparcos satellite. "Space astronomy has set the example in providing a high standard of data quality and making the data accessible to the scientific community through archives", says Roger Bonnet, ESA's Scientific Director. "Now, ground-based observatories are following suit. The data legacy of IUE will be distributed to he community so that research on IUE data can continue long after the end of IUE's lifetime in space". Wonders of ultraviolet spectroscopy IUE analysed ultraviolet light, in a wavelength range from 1150 to 3200 angstrom units, which is blotted out by the Earths atmosphere. Operating far above the atmosphere, IUE generated spectra showing intensities at different wavelengths, coming from the selected objects in the sky. To an astrophysicist, such spectra are much more informative than images, about the mechanisms that produce and dissipate the objects energy. Temperatures, motions, magnetism and chemical composition are all discernable in the ultraviolet spectra. As a result, astronomers have a far better picture of the hot atmospheres of stars than they did before IUE's launch. Even the Sun, a quiet star of moderate size, possesses a very hot atmosphere emitting ultraviolet light, which is now being monitored non-stop by the ESA-NASA solar spacecraft SOHO. Some other stars, ranging from small white dwarfs to large, massive stars, give off ultraviolet emissions from their very hot surfaces. Hot and fierce winds of gas emitted from stars have a profound effect on the lives and environments of the stars, and on any companions caught up in the winds. IUE unmasked the ultraviolet behaviour of a large menagerie of different star types, and astronomers at the Sevilla meeting will discuss profound revisions in astrophysical ideas resulting from the observations. Other participants will review IUE's contribution to new knowledge about galaxies. These vast assemblies of stars also reveal violent behaviour in ultraviolet light. In a special campaign, a multinational team used IUE to observe the stormy galaxy NGC 5548 some 60 times in eight months. As a result, they discovered effects of central outbursts spreading from hot regions at the very core of the galaxy to adjacent cooler regions, in a timescale of weeks. In galaxy NGC 7469, observed simultaneously by IUE and by the X-ray satellite Rossi XTE, the timescale shrank to days. Quasars are erupting galaxies observable at great distances, and their examination by ultraviolet light, by IUE and more recently by the Hubble Space Telescope, give special clues to the nature of the gas in the almost empty spaces between galaxies, and to the manufacture of the chemical elements within the galaxies. The quasar studies to be reviewed at Sevilla already occupy an important place in the efforts to understand the character and evolution of the Universe at large. The ultraviolet data on element-making suggest that massive stars, far bigger than the Sun, were more numerous when the galaxies were young. Advantages of a long life The sheer durability of IUE enabled astronomers to revisit many objects over nearly two decades and to see changes occurring with them. The prolonged study of the black hole in 3C390.3 was a case in point. Another conspicuous example of the advantages of a long life concerns Supernova 1987A. This star was seen exploding in a nearby galaxy, the Large Magellanic Cloud, half-way through IUEs operational life. IUE was the first space telescope to be turned towards Supernova 1987A. It revealed precisely which star had blown up, identified chemical elements in the debris, and discovered a pre-existing ring of gas and dust surrounding the star. IUE continued observing Supernova 1987A at intervals over nine years, so providing a unique chronicle of the early evolution of a supernova remnant. Lesser stellar outbursts called novae have also provided frequent "targets of opportunity" for IUE. The return of Halleys Comet in 1985-86 was a long anticipated event, and the ultraviolet observations by IUE measured the rate at which the famous object spewed water vapour into space. But many comets appear unexpectedly, and IUE was able to examine them too, from Comet Seargent in 1978 to Comet Hale-Bopp in 1986. Astronomers have built up a comprehensive picture of comets seen by ultraviolet light at different stages of their evolution, and at different distances from the Sun. As a result, they have a much better understanding of how comets react and change during their rare visits to the vicinity of the Sun and the Earth. IUEs long life also enabled it to observe rare and serendipitous events. The satellite was already more than sixteen years old when Comet Shoemaker-Levy 9 hit Jupiter in July 1994. The event was well anticipated, so IUE was able first to study Jupiter in a normal state, and then to see the changes in the ultraviolet spectra during and after the impacts of the comet fragments. The astronomers favourite satellite Operational and scientific statistics about IUE are remarkable. The satellites observations have resulted in more than 3600 scientific papers published by 3000 astronomers from 25 countries. In addition, about 500 doctoral theses using IUE data show the educational value of IUE in universities all over the world. Amateur astronomers have also shown a remarkable degree of interest in IUE results, which provide them with a valuable and important link between their activities and those of professional astronomers. "Although IUE never had the popular appeal of the Hubble Space Telescope, it was always the professional astronomers favourite satellite," remarks Willem Wamsteker, the Dutch astronomer who is ESA's project manager for IUE. "They could visit Villafranca or Goddard and supervise the operations, just as if they were at an observatory on the ground. Towards the end, they could make their observations remotely, without leaving their institutes. Historians of astronomy may well credit IUE with the big change in professional habits which made space observatories a tool, not just for a few hardware-minded specialists, but for all astronomers." The meeting in Sevilla will end on 14 November with a review of the prospects for new space missions for ultraviolet astronomy. The Hubble Space Telescope and some Space Shuttle missions offer limited opportunities for ultraviolet spectroscopy. So will ESA's XMM X-ray mission. The only confirmed mission fully dedicated to the ultraviolet region is NASA's FUSE spacecraft, due to be launched in the year 2000, with rather limited scope and duration. Astronomers in developing countries have been persuaded by experience with IUE that they too can participate in spaceborne observations without emigrating. ESA has helped to foster this ambition. A UN-ESA workshop in Sri Lanka in 1996 recommended the creation of a World Space Observatory, and this will be cited at the Sevilla meeting in the context of possible future facilities for ultraviolet astronomy. Meanwhile IUE will not be easy to replace. No authorized mission yet in sight will combine a wide spectral range with great flexibility of operation. Current astronomical campaigns, ranging from studies of auroras in planets to the efforts to understand the spectacular yet mysterious gamma-ray bursts far away in the cosmos, already miss the input from IUE. The astronomers sense of loss should be seen positively, as a tribute to IUEs achievements when it dominated ultraviolet space astronomy for nearly two decades.

49 CFR 173.52 - Classification codes and compatibility groups of explosives.

Code of Federal Regulations, 2012 CFR

2012-10-01

... or hypergolic liquid) E 1.1E1.2E 1.4E Article containing a secondary detonating explosive substance...-S 1.1 1.1A 1.1B 1.1C 1.1D 1.1E 1.1F 1.1G 1.1J 1.1L 9 1.2 1.2B 1.2C 1.2D 1.2E 1.2F 1.2G 1.2H 1.2J 1...

Vapor-liquid equilibria for the systems composed of 1-chloro-1,1-difluoroethane, 1,1-dichloro-1-fluoroethane, and 1,1,1-trichloroethane at 50.1 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Y.W.; Lee, Y.Y.

1996-03-01

Isothermal vapor-liquid equilibria for the three binary systems 1-chloro-1,1-difluoroethane + 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane + 1,1,1-trichloroethane, and 1,1-dichloro-1-fluoroethane + 1,1,1-trichloroethane and the ternary system 1-chloro-1,1-difluoromethane + 1,1-dichloro-1-fluoroethane + 1,1,1-trichloroethane have been measured at 50.1 C. The experimental data for the binary systems are correlated with the Peng-Robinson equation of state, and the relevant parameters are presented. The predicted results for the ternary system were found to be in good agreement with the experimental data.

76 FR 10036 - Agency Information Collection Request. 30-Day Public Comment Request, Grants.gov

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-23

... 1421 1 1421 1 1421 DOD 1 1 1 1 1 DOE 0 1 0 1 0 DOI 131 1 131 1 131 DOL 0 1 0 1 0 DOT 50 1 50 1 50 ED 0 1 0 1 0 EPA 0 1 0 1 0 HHS 52 1 52 1 52 HUD 0 1 0 1 0 IMLS 0 1 0 1 0 NARA 0 1 0 1 0 NASA 0 1 0 1 0...

49 CFR 173.52 - Classification codes and compatibility groups of explosives.

Code of Federal Regulations, 2013 CFR

2013-10-01

... or hypergolic liquid) E 1.1E1.2E 1.4E Article containing a secondary detonating explosive substance....1E 1.1F 1.1G 1.1J 1.1L 9 1.2 1.2B 1.2C 1.2D 1.2E 1.2F 1.2G 1.2H 1.2J 1.2K 1.2L 10 1.3 1.3C 1.3F 1.3G...

Relaxation of Shot-Peened Residual Stresses Under Creep Loading (Preprint)

DTIC Science & Technology

2008-10-01

6 1e-5 1e- 4 1e-3...22   1e-9 1e-8 1e-7 1e- 6 1e-5 1e- 4 1e-3 1e-2 1e-1 1e-3 1e-2 1e-1 -1% Prestrain 0% Prestrain +1% Prestrain +5% Prestrain To ta l S tra in R at e (/s...Prestrain. 23 1e-9 1e-8 1e-7 1e- 6 1e-5 1e- 4 1e-3 1e-2 1e-1 1e-3 1e-2 1e-1 -1% Prestrain 0% Prestrain +5% Prestrain To ta l S tra in R at e

76 FR 10033 - Agency Information Collection Request. 30-Day Public Comment Request, Grants.gov

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-23

... 1 148 1 148 ED 0 1 0 1 0 EPA 0 1 0 1 0 HHS 7814 1 7814 1 7814 HUD 0 1 0 1 0 IMLS 0 1 0 1 0 NARA 0 1 0 1 0 NASA 0 1 0 1 0 NEA 98 1 98 1 98 NEH 0 1 0 1 0 NIST 639 1 639 1 639 NRC 0 1 0 1 0 NSF 0 1 0 1 0...

Test Methodology for Protection of Vehicle Occupants against Anti-Vehicular Landmine Effects (Methodologie d’essais pour la protection des occupants de vehicules contre les effets des mines terrestres anti-vehicules)

DTIC Science & Technology

2007-04-01

1 Chapter 1 – Introduction 1 - 1 1.1 Background and Problem Definition 1 - 1 1.1.1...Background 1 - 1 1.1.2 Problem Definition 1 -2 1.2 The Objective and Approach of the HFM-090/TG-25 1 -2 1.2.1 Objective 1 -2 1.2.2 Approach 1 -2 1.3...Organization of this Report 1 -3 1.4 References 1 -3 Chapter 2 – The Mine Detonation Process and Occupant Loading 2- 1 2.1 Introduction to Mines 2- 1 2.2

Estimation of spline function in nonparametric path analysis based on penalized weighted least square (PWLS)

NASA Astrophysics Data System (ADS)

Fernandes, Adji Achmad Rinaldo; Solimun, Arisoesilaningsih, Endang

2017-12-01

The aim of this research is to estimate the spline in Path Analysis-based on Nonparametric Regression using Penalized Weighted Least Square (PWLS) approach. Approach used is Reproducing Kernel Hilbert Space at sobolev space. Nonparametric path analysis model on the equation y1 i=f1.1(x1 i)+ε1 i; y2 i=f1.2(x1 i)+f2.2(y1 i)+ε2 i; i =1 ,2 ,…,n Nonparametric Path Analysis which meet the criteria of minimizing PWLS min fw .k∈W2m[aw .k,bw .k], k =1 ,2 { (2n ) -1(y˜-f ˜ ) TΣ-1(y ˜-f ˜ ) + ∑k =1 2 ∑w =1 2 λw .k ∫aw .k bw .k [fw.k (m )(xi) ] 2d xi } is f ˜^=Ay ˜ with A=T1(T1TU1-1∑-1T1)-1T1TU1-1∑-1+V1U1-1∑-1[I-T1(T1TU1-1∑-1T1)-1T1TU1-1∑-1] columnalign="left">+T2(T2TU2-1∑-1T2)-1T2TU2-1∑-1+V2U2-1∑-1[I1-T2(T2TU2-1∑-1T2) -1T2TU2-1∑-1

Software Design Document Vehicle Simulation CSCI (5). Volume 1. Sections 1.0 - 2.2.3.1

DTIC Science & Technology

1991-06-01

388 2.1.5.1.3.1 bbd -bit-in ........................ 388 2.1.5.1.4 bit_out.c............................ 389 2.1.5.1.4.1 bbd -bit-out...in.c........................ 391 2.1.5.1.7.1 bbd_control-in.................... 391 2.1.5.1.8 control__out.c ...................... 391 2.1.5.1.8.1 bbd ...2.1.5.1.10.1 bbd -detach........................ 392 2.1.5.1.11 init.c................................. 392 2.1.5.1.11.1 bbd -imit............................. 392

Human Endothelial Cell Response to Gram-Negative Lipopolysaccharide Assessed with cDNA Microarrays

DTIC Science & Technology

2001-11-01

structurally and functionally similar to LO, may also possess chemotac- tic ability and other unknown functions in inflamma- tion. Spermidine/ spermine N1...2.0 1.1 0.7 0.8 H16591 Vascular cell adhesion molecule 1 VCAM-1 1.0 1.1 2.1 1.4 1.0 1.1 AA011215 Spermidine/ spermine N1-acetyltransferase SAT 0.8 1.0...1.1 N80129 Metallothionein 1L MT1L 4.8 1.0 1.0 1.7 1.2 1.1 AA430382 Nucleoside phosphorylase NP 1.1 1.4 1.8 1.3 1.0 AA676458 Lysyl oxidase -like 2 LOXL2

U.S. EPA, Pesticide Product Label, TECHNICAL MALEIC HYDRAZIDE FOR MANUFACTURING PURPOSE, 08/06/1971

EPA Pesticide Factsheets

2011-04-19

\\I.\\I.LIC IIYI>I~:\\I.IIII': HlI.: 1':1-:\\1.\\\\('1',\\,1('1\\1\\(; 1'('I

Eigenvalues of Covariance Matrix for Two-Source Array Processing

DTIC Science & Technology

1990-11-01

Using (IpI1I) 2 - !p1 2(1 - lp2). . = p 72 - (-1 + 11 1 - J J21 - Ipl2 ) - -(1 - Ip12) + (1 + ) 21 and setting to zero the derivative of the above...A2 decreases from A2(- pI 101, (1 - 1012)(1 - Ip12)) = (1 - IPIO) - 1 Ipl1l) 2 -(1 1012)(1 - Ipl2 ) = (1 - Ipll0l) - IlPI - I011, to A2(0,(1 - 11 2 )(1...IP12)) = 1 - 1- (1 - 112 )(1 - I1p2), to A2(IPIIOI, (1 - 102 )(1 - IPl2 )) = (1 + IPI1l) - 01T IP111) 2 - (1 - 112)(1 - Ipl2 ) = (1 + Ipll01) - (Ipl

76 FR 10037 - Agency Information Collection Request. 30-Day Public Comment Request, Grants.gov

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2011-02-23

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Regional Food Distribution Characteristics and a Methodology for Redistribution in Accordance with Crisis Relocation. Appendices.

DTIC Science & Technology

1980-07-01

3,000 NC HCNDEPSON 2 1 1 11,500 NC MECKLUECURG 4 4 44,000 NC POLK 1 1 1,500 NIC RICHMOND 1 1 1,500 NC TW A15Y LVANIA 1 1 3,000 NC YANCEY 1 1 7,000 SC...JEFFERSON 2 1 1 2-250 FKY NELSON 1 1 750 *~TOTAL 4 3 1 3,750 JELLICO GROCERY CO ELIZASETH70:41N TN NC YANCEY 1 1 750 TN CARTER 1 1 3,000 TOTAL 2 1 1...2 1 1 3,750 NC UNION 1 1 1,500 NC VANCE I 1 5,000 NC WATAUGA 4 2 7,500 NC WILKES 7 4 3 7,500 NC YADKIN 3 1 2 3,750 NC YANCEY 1 1 3,000 SC ANDERSON 4

Chemical characterization of milk oligosaccharides of the tiger quoll (Dasyurus maculatus), a marsupial.

PubMed

Urashima, Tadasu; Yamamoto, Tomoko; Hirayama, Kentaro; Fukuda, Kenji; Nakamura, Tadashi; Saito, Tadao; Newgrain, Keith; Merchant, Jim; Green, Brian; Messer, Michael

2016-10-01

Milk oligosaccharides were separated from the carbohydrate fraction of milk of the tiger quoll a species of marsupial that is closely related to the eastern quoll, Dasyurus viverrinus. They were characterized by (1)H - nuclear magnetic resonance spectroscopy and matrix - assisted laser desorption/ionization time-of-flight mass spectrometry. The following oligosaccharides were identified; Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Neu5Ac(α2-3) Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc with an α(2-3)Neu5Ac linked to β(1-4)Gal residue of either branch of Gal(β1-4)GlcNAc(β1-6) units, and Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc with a β(1-3) linked Gal and an α(2-3) linked Neu5Ac. In addition, larger oligosaccharides were characterized as follows; Gal(β1-3){Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)GlcNAc(β1-6)}Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc and Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3){Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)GlcNAc(β1-6)}Gal(β1-4)Glc and their α(2-3) linked Neu5Ac derivatives.

40 CFR Appendix Vii to Part 261 - Basis for Listing Hazardous Waste

Code of Federal Regulations, 2010 CFR

2010-07-01

... Tetrachloroethylene, methylene chloride trichloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, chlorinated fluorocarbons. F002 Tetrachloroethylene, methylene chloride, trichloroethylene, 1,1,1-trichloroethane, 1,1,2...-dichloroethylene, 1,1-dichloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, 1,1,1,2...

M-X Environmental Technical Report. Alternative Potential Operating Base Locations Dalhart.

DTIC Science & Technology

1980-12-22

CONTENTS PAGE 1.0 Dalhart and Vicinity Community Environment I 1.1 Human Environment I 1.1.1 Economic Activity 1 1.1.2 Public Finance 9 1.1.3 Population 9...county area. 1.1 HUMAN ENVIRONMENT ECONOMIC ACTIVITY (1.1.1) Employment Tables 1.1.1-1 and 1.1.1-2 highlight detailed employment characteristics of Dallam...clearinghouse responsible for planning in the subject region. The local planning activities are implemented under the authority of "Regional Planning Commissions

Dissociation mechanisms of HFO-1336mzz(Z) on Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces: A density functional theory study

NASA Astrophysics Data System (ADS)

Huo, Erguang; Liu, Chao; Xu, Xiaoxiao; Li, Qibin; Dang, Chaobin

2018-06-01

The catalytic effect of Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces on the decomposition of HFO-1336mzz(Z) have been investigated by using Density Functional Theory (DFT) calculations. On the basis of adsorption energy analysis, the most stable adsorption energies of HFO-1336mzz(Z) and relevant products on Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces were studied, respectively, and the co-adsorption structures of relevant species were obtained. Finally, four initiation decomposition reactions of HFO-1336mzz(Z) on Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces were proposed and investigated, respectively. At the same time, the four similar homolytic reactions of free HFO-1336mzz(Z) molecular were calculated to compare with the dissociation reactions occurred on Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces and illuminate the catalytic effect of Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces on the HFO-1336mzz(Z) decomposition. The results indicated that Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces had a good catalytic effect on the decomposition of HFO-1336mzz(Z). The fracture reactions of Cdbnd C bonds on Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces were easier to occur than that of other reactions. Cu(1 0 0) surface had the highest catalytic activity and the lowest for Cu(1 1 1) surface.

Word Criticality Analysis. MOS: 44B. Skill Levels 1 & 2.

DTIC Science & Technology

1981-09-01

IILh2- 51,1 2- 96,1 2- 40.A a- sv;t t. 94.1 2- Soil 2- 12,2 2- list 2-Z5,1 2- 170i 1. 10,1 2- 95.) 2- 19.1 Z- 50.1 1- 411 * 3 Slits 2- 57j,1 0 3...46.1 2- 44,1 2- 43,1 2- 411J 2- . , 1 2- 53,1 2- .2. 2- 51,1 2- Soil 2- 49,1 2- 68.1 2- 47.1 4 APIII’l~if 2-.2 , SATTERIFS Z- 25,1 2 1 6 PIJ$1| " 2...9s1 2 9 1 2 lt 2 71 2 6 o -63,1 2- 94𔃻 2- 00 2- 0,1 2- 95,1 2- 96,1 2-10001 2- 96.1 A USL 2, 91.1 2 59,1 2- 16.1 2- 51 -1- 40,1 2’ 401 2- 31,2 2- 30#2

Guidelines for Flight Planning during Periods of High Ozone Occurrence

DTIC Science & Technology

1978-01-11

50 4YO 1,.0 1,3 1,a7 ?,0 1, ,S a 0 ’ 470 .9 1.2 1,.5 1, l.S 3r) •tO , II L b 0 ,) 1 . 26,2 460 .7 1.0 1,a3 1~ a , 6 20 450 .60 q9 1, -2 , L I .I .14...45 .60 .7 .9 𔃻.1 .16 4YO .35 .45 .bO .7 .8 .12 470 .35 .50 .60 *a .9 .10 470 .30 .40 .50 o4O .6S .08 450 ,05 .40 .50 .60 .65 *04 4ý0 .20 .30 .40...5 .7 1.o .7* 530 1.1 1.4 1.7 2.0 1.7 .55 530 .8 1.0 1.1 1.3 1..’ .46 610 1.0 1.3 l.b 1.8 I.8 45 S10 .a .9 111 1.2 1.1 .40 4YO .q 1.1 1.4 1.7 1.3 4o0

M-X Environmental Technical Report. Alternative Potential Operating Base Locations: Ely.

DTIC Science & Technology

1980-12-22

and Vicinity Community Environment 1 1.1 Human Environment 1.1.1 Economic Activity 1.1.2 Public Finance 3 1.1.3 Population A8 1.1.4 Land Use 16 1.1.5...Base Vicinity 63 2.1 Human Environment 63 2.1.1 Effects on Employment (Jobs) and Labor Force 63 2.1.2 Effects on Income and Earnings 66 2.1.3 Effects...vicinity. 1.1 HUMAN ENVIRONMENT Economic Activity (1.1.1) Once a part of Lander County, White Pine County was organized separately on April 1, 1869. This was

A Dynamic Programming Approach to the Daily Routing of Aeromedical Evacuation System Missions

DTIC Science & Technology

1989-06-08

1 AEX 1 HSV 1 ADW 4 NKT 2 BYH 1 NKX 1 MXF 3 *CAE 1 ROA 1 SZL 1 *SBD 1 BLV 4 BOS 1 CMI 2 AGS 1 WRI 1 SAW 2 BHM 1 NHZ 1 BTL 1 YNG 1 RST 1 ...LAX 1 BLV 4 BKF 4 HSV 3 NIP 3 PVD 4 *CHD 1 NQA 2 BLV 3 SWF 1 ABQ 2 GUS I DHN 1 RME 2 NKX 2 OSC 2 *MEI 1 EWR 3 SAW 2 CBM 1 WRI 2 BYH I *NMM 1 PBG 1

Hazardous Waste Land Disposal Facility Assessment. Volume 2. Appendices

DTIC Science & Technology

1988-09-01

ADVERTISEMENT. 1 ~ I 3 TABLE OF CONTENTS VOLUME I -RMORT 1.0 SUNMARY ............. . . .... . 1 - 1 1.1 PURPOSE ............ . .... . 1 - 1 1.2 SCOPE... 1 - 1 1.3 CONCLUSIONS................................ 1 -2 1 .4 RECOHIDA TIONS . . . . . ............... 1 -3 2.0 INTRODUCTION...2- 1 3.0 SITE SELECTION ...... . . ............. 3- 1 3.1 OBJECTIVES AND BACKGROUND ............... ... 3- 1 3.2 GENERAL RMA

Association Between Inflammatory Skin Disease and Cardiovascular and Cerebrovascular Co-Morbidities in US Adults: Analysis of Nationwide Inpatient Sample Data.

PubMed

Kwa, Michael C; Silverberg, Jonathan I

2017-12-01

Psoriasis, atopic dermatitis or eczema (AD-E), pemphigus, bullous pemphigoid (BP), and hidradenitis are chronic inflammatory skin disorders associated with systemic immune activation, considerable symptom burden, stigma, functional disturbances, and mental health symptoms. All of these might increase cardiovascular risk. The objective of this study was to determine whether these inflammatory skin diseases are associated with increased cardiovascular/cerebrovascular risk and/or disease. We analyzed data from the 2002-2012 National Inpatient Sample, including a representative 20% sample of all US hospitalizations (n = 72,108,077 adults). In multivariate logistic regression models with propensity score matching, patients hospitalized with versus without a diagnosis the inflammatory skin diseases examined had higher odds of obesity (odds ratio [95% confidence interval] for pemphigus: 1.16 [1.05-1.29]; BP 1.14 [1.06-1.23]; AD-E: 1.82 [1.79-1.86]; psoriasis: 2.36 [2.32-2.41]; hidradenitis: 2.79 [2.59-3.01]). Inflammatory skin disease was also associated with significantly higher odds of different cardiovascular risk factors, including hypertension (pemphigus: 1.39 [1.31-1.48]; BP 1.96 [1.88-2.05]; AD-E: 1.19 [1.17-1.21]; psoriasis: 1.61 [1.59-1.64]), and diabetes mellitus with complications (pemphigus: 1.34 [1.18-1.52]; BP: 2.06 [1.90-2.24]; AD-E: 1.13 [1.10-1.17]; psoriasis: 1.39 [1.35-1.44]), as well as vascular, cardiovascular, and cerebrovascular disease, including peripheral vascular disease (pemphigus: 1.14 [1.00-1.30]; BP: 1.83 [1.69-1.98]; AD-E: 1.18 [1.14-1.22]; psoriasis: 1.32 [1.28-1.35]), peripheral and visceral atherosclerosis (BP: 1.67 [1.53-1.81]; AD-E: 1.16 [1.12-1.20]; psoriasis: 1.27 [1.24-1.30]), pulmonary circulation disorders (pemphigus: 1.67 [1.39-2.01]; BP: 2.17 [1.92-2.45]; AD-E: 1.39 [1.33-1.45]; psoriasis: 1.37 [1.31-1.43]), congestive heart failure (pemphigus: 1.75 [1.60-1.90]; BP: 2.82 [2.68-2.98]; AD-E: 1.10 [1.07-1.13]; psoriasis: 1.05 [1.02-1.07]), history of transient ischemic attack (pemphigus: 1.36 [1.14-1.62]; BP: 2.03 [1.83-2.26]; AD-E: 1.19 [1.15-1.23]; psoriasis: 1.31 [1.26-1.36]), and cerebrovascular disease. In stratified analyses, multiple inflammatory skin diseases were associated with significantly higher rates of obesity, hypertension, and/or diabetes in patients aged <50 years and females. Psoriasis, pemphigus, BP, AD-E, and hidradenitis were all associated with increased cardiovascular and cerebrovascular risk, especially at younger age.

A Comparison of the Meal, Ready-to-Eat, Ration, Cold Weather, and Ration, Lightweight Nutrient Intakes during Moderate Altitude Cold Weather Field Training Operations

DTIC Science & Technology

1988-11-01

SCE 107 1/4 1/2 3/4 1 2 CHICKEN A LA KING 176 1/4 1/2 3/4 1 2 BEEF STEW 113 1/4 1/2 3/4 1 2 HAM SLICE 105 1/4 1/2 3/4 1 2 MEATBALLS W/RICE 109 1/4 1/2...KING 176 1/4 1/2 3/4 1 2 BEEF STEW 113 1/4 1/2 3/4 1 2 HAM SLICE 105 1/4 1/2 3/4 1 2 MEATBALLS W/RICE 109 1/4 1/2 3/4 1 2 TUNA W/NOODLES 111 1/4 1/2 3

The Frequency Response and Operating Characteristics of the XR-3 Loads and Motions Program

DTIC Science & Technology

1976-06-01

TD -t- M - \\ \\ t:5Tt \\ ’X ^pl 1 \\ \\\\ 1 1 1 r ^ ’ 1 ^ ;f<i^^ ’ 1:^’ ’ 1 ’ 1 \\ J ) i ! r ;i 1 MM III I’MrMr^m 1 1 ’ 1 111’ 1 : ; 11 I ! i ; ! i...Operating Characteristics V=30 kts, A=0.3 ft, Ahead Seas 92 + 1 i h +- .... ^ _|_ „ . . , 1 , . . . , .,_ . , 1 J _lJ 1 i I .. ._ ., . td ii ! ! 1 1 1 T 1...rrPP I 1 1 i-j-K -w III -r-f-j-^- 1 1 i 1 --i*i- -r-HJ-U+f u**—^—^ .^ -« td ^:ii:=niri;: -^ H-r— -j-O* *- " LjS : ; 1 h i ! ’ 1 ’ i 1 ^ AJ —

49 CFR 172.411 - EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels..., 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label. (a) Except for size and color....5 and EXPLOSIVE 1.6 labels must be as follows: EXPLOSIVE 1.4: EC02MR91.016 EXPLOSIVE 1.5: EC02MR91...

20 CFR 404.409 - What is full retirement age?

Code of Federal Regulations, 2010 CFR

2010-04-01

.... 1/2/1939—1/1/1940 65 years and 4 months. 1/2/1940—1/1/1941 65 years and 6 months. 1/2/1941—1/1/1942... and 6 months. 1/2/1958—1/1/1959 66 years and 8 months. 1/2/1959—1/1/1960 66 years and 10 months. 1/2... and 6 months. 1/2/1943—1/1/1944 65 years and 8 months. 1/2/1944—1/1/1945 65 years and 10 months. 1/2...

CH4 dehydrogenation on Cu(1 1 1), Cu@Cu(1 1 1), Rh@Cu(1 1 1) and RhCu(1 1 1) surfaces: A comparison studies of catalytic activity

NASA Astrophysics Data System (ADS)

Zhang, Riguang; Duan, Tian; Ling, Lixia; Wang, Baojun

2015-06-01

In the CVD growth of graphene, the reaction barriers of the dehydrogenation for hydrocarbon molecules directly decide the graphene CVD growth temperature. In this study, density functional theory method has been employed to comparatively probe into CH4 dehydrogenation on four types of Cu(1 1 1) surface, including the flat Cu(1 1 1) surface (labeled as Cu(1 1 1)) and the Cu(1 1 1) surface with one surface Cu atom substituted by one Rh atom (labeled as RhCu(1 1 1)), as well as the Cu(1 1 1) surface with one Cu or Rh adatom (labeled as Cu@Cu(1 1 1) and Rh@Cu(1 1 1), respectively). Our results show that the highest barrier of the whole CH4 dehydrogenation process is remarkably reduced from 448.7 and 418.4 kJ mol-1 on the flat Cu(1 1 1) and Cu@Cu(1 1 1) surfaces to 258.9 kJ mol-1 on RhCu(1 1 1) surface, and to 180.0 kJ mol-1 on Rh@Cu(1 1 1) surface, indicating that the adsorbed or substituted Rh atom on Cu catalyst can exhibit better catalytic activity for CH4 complete dehydrogenation; meanwhile, since the differences for the highest barrier between Cu@Cu(1 1 1) and Cu(1 1 1) surfaces are smaller, the catalytic behaviors of Cu@Cu(1 1 1) surface are very close to the flat Cu(1 1 1) surface, suggesting that the morphology of Cu substrate does not obviously affect the dehydrogenation of CH4, which accords with the reported experimental observations. As a result, the adsorbed or substituted Rh atom on Cu catalyst exhibit a better catalytic activity for CH4 dehydrogenation compared to the pure Cu catalyst, especially on Rh-adsorbed Cu catalyst, we can conclude that the potential of synthesizing high-quality graphene with the help of Rh on Cu foils may be carried out at relatively low temperatures. Meanwhile, the adsorbed Rh atom is the reaction active center, namely, the CVD growth can be controlled by manipulating the graphene nucleation position.

Census of U.S. Civil Aircraft for Calendar Year 1983.

DTIC Science & Technology

1983-12-31

8217JR r~0 b W ~ .- 4b im~ (’ jb C, .t b 𔄁 j% 𔃾t m0 * -apt4 Uco~ -W(4(.et uO cy(’ (’- 0 0 0 ’-V ’) Wg ’ .4a 0LOc0,).444 O ) 0 % - r-o 0’U ko 4t 0 0 0s...61 1 0 1 1 JONESIE 4248 1 64 2 0 1 1 ROTOR REC ENGINE 61 0 1 1 ROTOR TURBOJET 84 0 1 1 TOTAL 0 2 2 KAMAN H-43A 2 61 1 0 2 2 H-43B 2 61 1 0 2 2 HH -43F...1 ’ORMER 1 41 1 0 1 1 :UDA 2 41 1 0 15 15 ’UDA300 2 41 10 1 1 "T SKYBOLT 2 41 1 0 1 1 "SKYDTE 1 41 1 0 1 1 JB MK REPLICA 1 41 1 0 1 1 I-HEATH 1 41 1

Experimental Testing of Flying Qualities Theories.

DTIC Science & Technology

1982-12-01

z -,.5 Z,2 - * .5 3 : 5. 8 56, akl 57.-o -7) g j * -,j " bl6 1 1D2o.UD :)3o J5 , .. 65.. 23°Z u 7.2,, b ob . Z. : 6 7 J.e2 2 7 1,*23 7. .e23 73. -3...l b5 1 .. ) 1 . 1. ’, 1.60 1.u0 1.c61 1.,62 1.o :).1) 1 .5q 1.59 1 Ib" 1. 1 1.t) 4 ! 1 IC? 1.59 1.62 1 1 6. . b16 l.L6 1.b, l.h- . 1.(02 o~2J o . ] t

49 CFR 172.411 - EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels..., EMERGENCY RESPONSE INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Labeling § 172.411 EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label. (a) Except for size and color...

Interaction of hydrated electron with dietary flavonoids and phenolic acids: rate constants and transient spectra studied by pulse radiolysis.

PubMed

Cai, Z; Li, X; Katsumura, Y

1999-10-01

The reaction rate constants and transient spectra of 11 flavonoids and 4 phenolic acids reacting with e(aq)- at neutral pH were measured. Absorption bands of the transients of e(aq)- reacting with the above compounds all located at a wavelength shorter than 400 nm. The e(aq)- scavenging abilities were divided into three groups: (+)catechin ((1.2 +/-0.1) x 10(8) M(-1)s(-1)) < 4-chromanol ((4.4 +/- 0.4) x 10(8) M(-1)s(-1)) < genistein ((6.2+/-0.4) x 10(9) M (-1) s(-1) approximately genistin ((8 +/- 1) x 10(9) M(-1)s(-1)) approximately rutin ((7.6 +/- 0.4) x M(-1)s(-1) approximately caffeic acid ((8.3 +/- 0.5) x 10(9)M(-1)s(-1)) < transcinnamic acid((1.1 +/- 0.1) x 10(10) M(-1)s(-1)) approximately p-coumaric acid ((1.1 +/- 0.1) x 10(10) M(-1)s(-1) approximately 2,4,6-trihydroxylbenzoic acid((1.1 +/- 0.1) x 10(10) M(-1)s(-1)) approximately baicalein ((1.1 +/- 0.5) x 10(10) M(-1)s(-1)) approximately baicalin((1.3 + 0.1) X 10(10) M(-1)s(-1)) approximately naringenin ((1.2 +/- 0.1) x 10(10) M(-1)s(-1)) approximately naringin ((1.0 +/- 0.1) x 10(10) M(-1)s(-1)) approximately gossypin((1.2 +/- 0.1) x 10(10) M(-1)s(-1)) approximately quercetin((1.3 +/- 0.5) x 10(10) M(-1)s(-1)). These results suggested that C4 keto group is the active site for e(aq)- to attack on flavonoids and phenolic acids, whereas the o-dihydroxy structure in B ring, the C2,3 double bond, the C3-OH group, and glucosylation, which are key structures that influence the antioxidant activities of flavonoids and phenolic acids, have little effects on the e(aq)- scavenging activities.

Successive Interference Cancellation in Rake Receiver for CDMA Signals

DTIC Science & Technology

2009-06-01

Madkour [1], who worked on algorithms in 2002, to cancel out...Hadamard matrix is produced as shown in Figure 2 [2].  1 1H  1 1 2 1 1 1 1 1 1 H H H H H             2 2 4 2 2 1 1 1 1...1 1 1 1 1 1 1 1 1 1 1 1 H H H H H                    Figure 2. Production of Walsh functions. The

Reduction of halogenated ethanes by green rust.

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Loughlin, E. J.; Burris, D. R.; Environmental Research

Green rusts, mixed Fe{sup II}/Fe{sup III} hydroxide minerals present in many suboxic environments, have been shown to reduce a number of organic and inorganic contaminants. The reduction of halogenated ethanes was examined in aqueous suspensions of green rust, both alone and with the addition of Ag{sup I} (AgGR) and Cu{sup II} (CuGR). Hexachloroethane (HCA), pentachloroethane (PCA), 1,1,1,2-tetrachloroethane (1,1,1,2-TeCA), 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA), 1,1,1-trichloroethane (1,1,1-TCA), 1,1,2-trichloroethane (1,1,2-TCA), 1,1-dichloroethane (1,1-DCA), and 1,2-dibromoethane were reduced in the presence of green rust alone, AgGR, or CuGR; only 1,2-dichloroethane and chloroethane were nonreactive. The reduction was generally more rapid for more highly substituted ethanes than for ethanesmore » having fewer halogen groups (HCA > PCA > 1,1,1,2-TeCA > 1,1,1-TCA > 1,1,2,2-TeCA > 1,1,2-TCA > 1,1-DCA), and isomers with the more asymmetric distributions of halogen groups were more rapidly reduced than the isomer with greater symmetry (e.g., 1,1,1-TCA > 1,1,2-TCA). The addition of Ag{sup I} or Cu{sup II} to green rust suspensions resulted in a substantial increase in the rate of halogenated ethane reduction as well as significant differences in the product distributions with respect to green rust alone.« less

NAS (HOST/ARTS IIIA) to VME Modem Interface ATC Interface Hardware Manual

DTIC Science & Technology

1990-10-01

SIXT,RXSYNC,RXACTIVE,ALLOWI) IO,C,0,1,O,O1 - > [^bf,1,1,O,0J;vector 104 [o,c,0,1,o,0J -> [^hf,1,1,O,OJ;vector [I,C,0,1,O,0] -> [Abf,1,1,0,OJ;vector IO,C...VFU.T(R 501 C’-35 Io,c,1,1,o,o,o1 -> rhb ,0,01;i [X,C,1,1,0,O,1] -> ["hf,0,0; [1,C,1,I,0,1,01 -> [^ha,0,1];LACT (MTE)-S2 io,C,,1,0,1,01 -> I^ha,0,1; [1

A Coupled Creep-Plasticity Model for Residual Stress Relaxation of a Shot-Peened Nickel-Base Superalloy

DTIC Science & Technology

2007-05-01

4 1e+5 1e+ 6 1000MPa... 6 1e-5 1e- 4 1e-3 1e-2 1e-1 1e-1 1e+0 1e+1 1e+2 1e+3 1e+ 4 1e+5 1e+ 6 1000MPa 900MPa 800MPa C re ep R at e (/s ) Creep Time (s) 0% Prestrain, 650°C...increase in strain rate. The change in deformation response is significant even for small plastic strains. 1e-9 1e-8 1e-7 1e- 6 1e-5 1e- 4 1e-3

Indirect Rise of Power: China’s Economic and Military Growth and its Changing Relationship with the United States

DTIC Science & Technology

2012-05-01

increasing scrutiny as economies throughout the globe deal with recessions and market swings . The consequence of keeping the Chinese Yuan fixed at a low...092 1 1 1 1 1 1 1 - - SSB Golf Type 031 1 1 1 1 1 1 1 1 1 SSN Nuclear Attack Submarines - - - - - - - 1 1 SSN NEWCON Type 095 - - - - - - - 1 3 SSN

Are Sewage Treatment Plants Promoting Antibiotic Resistance?

EPA Science Inventory

1. Introduction 1.1. How bacteria exhibit resistance 1.1.1. Resistance to -lactams 1.1.2. Resistance to sulphonamides and trimethoprim 1.1.3. Resistance to macrolides 1.1.4. Resistance to fluoroquinolones 1.1.5. Resistance to tetracyclines 1.1.6. Resistance to nitroimidaz...

HLA DPA1, DPB1 alleles and haplotypes contribute to the risk associated with type 1 diabetes: analysis of the type 1 diabetes genetics consortium families.

PubMed

Varney, Michael D; Valdes, Ana Maria; Carlson, Joyce A; Noble, Janelle A; Tait, Brian D; Bonella, Persia; Lavant, Eva; Fear, Anna Lisa; Louey, Anthony; Moonsamy, Priscilla; Mychaleckyj, Josyf C; Erlich, Henry

2010-08-01

To determine the relative risk associated with DPA1 and DPB1 alleles and haplotypes in type 1 diabetes. The frequency of DPA1 and DPB1 alleles and haplotypes in type 1 diabetic patients was compared to the family based control frequency in 1,771 families directly and conditional on HLA (B)-DRB1-DQA1-DQB1 linkage disequilibrium. A relative predispositional analysis (RPA) was performed in the presence or absence of the primary HLA DR-DQ associations and the contribution of DP haplotype to individual DR-DQ haplotype risks examined. Eight DPA1 and thirty-eight DPB1 alleles forming seventy-four DPA1-DPB1 haplotypes were observed; nineteen DPB1 alleles were associated with multiple DPA1 alleles. Following both analyses, type 1 diabetes susceptibility was significantly associated with DPB1*0301 (DPA1*0103-DPB1*0301) and protection with DPB1*0402 (DPA1*0103-DPB1*0402) and DPA1*0103-DPB1*0101 but not DPA1*0201-DPB1*0101. In addition, DPB1*0202 (DPA1*0103-DPB1*0202) and DPB1*0201 (DPA1*0103-DPB1*0201) were significantly associated with susceptibility in the presence of the high risk and protective DR-DQ haplotypes. Three associations (DPB1*0301, *0402, and *0202) remained statistically significant when only the extended HLA-A1-B8-DR3 haplotype was considered, suggesting that DPB1 alone may delineate the risk associated with this otherwise conserved haplotype. HLA DP allelic and haplotypic diversity contributes significantly to the risk for type 1 diabetes; DPB1*0301 (DPA1*0103-DPB1*0301) is associated with susceptibility and DPB1*0402 (DPA1*0103-DPB1*0402) and DPA1*0103-DPB1*0101 with protection. Additional evidence is presented for the susceptibility association of DPB1*0202 (DPA1*0103-DPB1*0202) and for a contributory role of individual amino acids and DPA1 or a gene in linkage disequilibrium in DR3-DPB1*0101 positive haplotypes.

Pentacene on Au(1 1 1), Ag(1 1 1) and Cu(1 1 1): From physisorption to chemisorption.

PubMed

Lu, Meng-Chao; Wang, Rong-Bin; Yang, Ao; Duhm, Steffen

2016-03-09

We measured the electronic and the molecular surface structure of pentacene deposited on the (1 1 1)-surfaces of coinage metals by means of ultraviolet photoelectron spectroscopy (UPS) and low-energy electron diffraction (LEED). Pentacene is almost flat-lying in monolayers on all three substrates and highly ordered on Au(1 1 1) and on Cu(1 1 1). On Ag(1 1 1), however, weak chemisorption leads to almost disordered monolayers, both, at room temperature and at 78 K. On Cu(1 1 1) pentacene is strongly chemisorbed and the lowest unoccupied molecular orbital becomes observable in UPS by a charge transfer from the substrate. On Ag(1 1 1) and Cu(1 1 1) multilayers adopt a tilted orientation and a high degree of crystallinity. On Au(1 1 1), most likely, also in multilayers the molecular short and long axes are parallel to the substrate, leading to a distinctively different electronic structure than on Ag(1 1 1) and Cu(1 1 1). Overall, it could be demonstrated that the substrate not only determines the geometric and electronic characteristics of molecular monolayer films but also plays a crucial role for multilayer film growth.

Word Criticality Analysis MOS: 15D. Skill Levels 1 & 2.

DTIC Science & Technology

1981-09-01

0p -o1 2-91D1 2-290,1 -2- 27002 -2-245,1 2-12101 apcisoti 2-140,2 "P nSNPG2-155,1 ’ 2 PL~1%UNOI:S 2:146,#2 I POSITLIW 2 264,1I __...POSS IALr . ___2*2...UUALLY _ 2-224,1 2 T1,1 - 91,2 2- 92.2 2- 91.1 3 15.1 A- 17s1 3- 16#1 3- 44.2 1- 7201 3- ISO [ 1- I0,i Z TLZ - 94,1 3- 14,1 3- 1.. 3- 12.1 3- 11.1 2- 90,1

Patuxent River NAS, Maryland. Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F.

DTIC Science & Technology

1982-05-14

1L,99 *7 10 1i J S2 1.3 *9 ISO ~ ~ .1 61 07 6112 *26 9 . S3 .35 . : .9 : 1609 01 .5 3:01 .6 T 2.5 .9 69 3.? S41 141 2:4 0; TJ 1T em 41 eY .7 15 16...v. 1.1 2.6 1.5 *I S.4 S.% 9 1*7 0.31 . 2.9 4*9 08 O_____ 2.S 6.31 0-- 1 r *1---------------------------5 3*31 - 1.0 .6 165_ i.,-i ( 1*s 2.1 ISO *1 5.0...1.6 449 l.1 *1 7.5 .0 ISO 1. Z.0 1.4 e1 I__ I ___ 1 ___ ____ 05 5.o (u 1* .54 -T -TT- .a. 1.0 2.2 1.* 2__ _______ . T ( ~s 13 * 1.1 1.2 __ __ __ 2.7

Inhibition of CYP1 by berberine, palmatine, and jatrorrhizine: Selectivity, kinetic characterization, and molecular modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lo, Sheng-Nan; Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei 112, Taiwan, ROC; Chang, Yu-Ping

Cytochrome P450 (P450, CYP) 1 family plays a primary role in the detoxification and bioactivation of polycyclic aromatic hydrocarbons. Human CYP1A1, CYP1A2, and CYP1B1 exhibit differential substrate specificity and tissue distribution. Berberine, palmatine, and jatrorrhizine are protoberberine alkaloids present in several medicinal herbs, such as Coptis chinensis (Huang-Lian) and goldenseal. These protoberberines inhibited CYP1A1.1- and CYP1B1.1-catalyzed 7-ethoxyresorufin O-deethylation (EROD) activities, whereas CYP1A2.1 activity was barely affected. Kinetic analysis revealed that berberine noncompetitively inhibited EROD activities of CYP1A1.1 and CYP1B1.1, whereas palmatine and jatrorrhizine caused either competitive or mixed type of inhibition. Among protoberberines, berberine caused the most potent and selectivemore » inhibitory effect on CYP1B1.1 with the least K{sub i} value of 44 ± 16 nM. Berberine also potently inhibited CYP1B1.1 activities toward 7-ethoxycoumarin and 7-methoxyresorufin, whereas the inhibition of benzo(a)pyrene hydroxylation activity was less pronounced. Berberine inhibited the polymorphic variants, CYP1B1.3 (V432L) and CYP1B1.4 (N453S), with IC{sub 50} values comparable to that for CYP1B1.1 inhibition. Berberine-mediated inhibition was abolished by a mutation of Asn228 to Thr in CYP1B1.1, whereas the inhibition was enhanced by a reversal mutation of Thr223 to Asn in CYP1A2.1. This result in conjugation with the molecular modeling revealed the crucial role of hydrogen-bonding interaction of Asn228 on CYP1B1.1 with the methoxy moiety of berberine. These findings demonstrate that berberine causes a selective CYP1B1-inhibition, in which Asn228 appears to be crucial. The inhibitory effects of berberine on CYP1B1 activities toward structurally diverse substrates can be different. - Highlights: • Berberine preferentially inhibited CYP1B1 activity. • Berberine caused similar inhibitory effects on CYP1B1.1, CYP1B1.3 and CYP1B1.4. • Asn228 in CYP1B1 was an important residue for berberine-mediated inhibition.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paquette, Stéphane G.; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario; Banner, David

Pandemic H1N1 influenza A (H1N1pdm) elicits stronger pulmonary inflammation than previously circulating seasonal H1N1 influenza A (sH1N1), yet mechanisms of inflammatory activation in respiratory epithelial cells during H1N1pdm infection are unclear. We investigated host responses to H1N1pdm/sH1N1 infection and virus entry mechanisms in primary human bronchial epithelial cells in vitro. H1N1pdm infection rapidly initiated a robust inflammatory gene signature (3 h post-infection) not elicited by sH1N1 infection. Protein secretion inhibition had no effect on gene induction. Infection with membrane fusion deficient H1N1pdm failed to induce robust inflammatory gene expression which was rescued with restoration of fusion ability, suggesting H1N1pdm directlymore » triggered the inflammatory signature downstream of membrane fusion. Investigation of intra-virion components revealed H1N1pdm viral RNA (vRNA) triggered a stronger inflammatory phenotype than sH1N1 vRNA. Thus, our study is first to report H1N1pdm induces greater inflammatory gene expression than sH1N1 in vitro due to direct virus–epithelial cell interaction. - Highlights: • We investigated H1N1pdm/sH1N1 infection in primary epithelial cells. • H1N1pdm directly initiated a robust inflammatory gene signature, sH1N1 did not. • H1N1pdm viral RNA triggered a stronger response than sH1N1. • H1N1pdm induces greater response due to direct virus–cell interaction. • These results have potential to impact vaccine and therapeutic development.« less

Epitaxial growth of lithium fluoride on the (1 1 1) surface of CaF 2

NASA Astrophysics Data System (ADS)

Klumpp, St; Dabringhaus, H.

1999-08-01

Growth of lithium fluoride by molecular beam epitaxy on the (1 1 1) surface of calcium fluoride crystals was studied by TEM and LEED for crystal temperatures from 400 to 773 K and impinging lithium fluoride fluxes from 3×10 11 to 3×10 14 cm -2 s -1. Growth starts, usually, at the <1 1 0> steps on the (1 1 1) surface of CaF 2. For larger step distances and at later growth stages also growth on the terraces between the steps is found. Preferably, longish, roof-like crystallites are formed, which can be interpreted by growth of LiF(2 0 1¯)[0 1 0] parallel to CaF 2(1 1 1)[ 1¯ 0 1]. To a lesser extent square crystallites, i.e. growth with LiF(0 0 1), and, rarely, three-folded pyramidal crystallites, i.e. growth with LiF(1 1 1) parallel to CaF 2(1 1 1), are observed. While the pyramidal crystallites show strict epitaxial orientation with LiF[ 1¯ 0 1]‖CaF 2[ 1¯ 0 1] and LiF[ 1¯ 0 1]‖CaF 2[1 2¯ 1], only about 80% of the square crystallites exhibit an epitaxial alignment, where LiF[1 0 0]‖CaF 2[ 1¯ 0 1] is preferred to LiF[1 1 0]‖CaF 2[ 1¯ 0 1]. The epitaxial relationships are discussed on the basis of theoretically calculated adsorption positions of the lithium fluoride monomer and dimer on the terrace and at the steps of the CaF 2(1 1 1) surface.

Genetic regulation of IL1RL1 methylation and IL1RL1-a protein levels in asthma.

PubMed

Dijk, F Nicole; Xu, Chengjian; Melén, Erik; Carsin, Anne-Elie; Kumar, Asish; Nolte, Ilja M; Gruzieva, Olena; Pershagen, Goran; Grotenboer, Neomi S; Savenije, Olga E M; Antó, Josep Maria; Lavi, Iris; Dobaño, Carlota; Bousquet, Jean; van der Vlies, Pieter; van der Valk, Ralf J P; de Jongste, Johan C; Nawijn, Martijn C; Guerra, Stefano; Postma, Dirkje S; Koppelman, Gerard H

2018-03-01

Interleukin-1 receptor-like 1 ( IL1RL1 ) is an important asthma gene. (Epi)genetic regulation of IL1RL1 protein expression has not been established. We assessed the association between IL1RL1 single nucleotide polymorphisms (SNPs), IL1RL1 methylation and serum IL1RL1-a protein levels, and aimed to identify causal pathways in asthma.Associations of IL1RL1 SNPs with asthma were determined in the Dutch Asthma Genome-wide Association Study cohort and three European birth cohorts, BAMSE (Children/Barn, Allergy, Milieu, Stockholm, an Epidemiological survey), INMA (Infancia y Medio Ambiente) and PIAMA (Prevention and Incidence of Asthma and Mite Allergy), participating in the Mechanisms of the Development of Allergy study. We performed blood DNA IL1RL1 methylation quantitative trait locus (QTL) analysis (n=496) and (epi)genome-wide protein QTL analysis on serum IL1RL1-a levels (n=1462). We investigated the association of IL1RL1 CpG methylation with asthma (n=632) and IL1RL1-a levels (n=548), with subsequent causal inference testing. Finally, we determined the association of IL1RL1-a levels with asthma and its clinical characteristics (n=1101). IL1RL1 asthma-risk SNPs strongly associated with IL1RL1 methylation (rs1420101; p=3.7×10 -16 ) and serum IL1RL1-a levels (p=2.8×10 -56 ). IL1RL1 methylation was not associated with asthma or IL1RL1-a levels. IL1RL1-a levels negatively correlated with blood eosinophil counts, whereas there was no association between IL1RL1-a levels and asthma.In conclusion, asthma-associated IL1RL1 SNPs strongly regulate IL1RL1 methylation and serum IL1RL1-a levels, yet neither these IL1RL1- methylation CpG sites nor IL1RL1-a levels are associated with asthma. Copyright ©ERS 2018.

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

78 FR 48824 - Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-12

.... Turboshaft Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking.... Arriel 1A1, 1A2, 1B, 1C, 1C1, 1C2, 1D, 1D1, 1E2, 1K1, 1S, and 1S1 turboshaft engines. This proposed AD was prompted by a ``chip illumination event'' in flight on a Turbomeca S.A. Arriel 1 engine. This...

Word Criticality Analysis. MOS: 26L. Skill Levels 1 & 2.

DTIC Science & Technology

1981-09-01

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Word Frequency Analysis. MOS: 33S. Skill Levels 1 & 2.

DTIC Science & Technology

1981-05-01

rts Wq -1A~ ttSttii AArjtr I TF1 P!16 1,1,1 PAGE 1 TV 1" r Y Nsv’r 1 1 - ? I l1 1 , .I I I o ’ , ’’II A T 1T1 1 1 1Ilr A-r P y? A T f TS...TIFl’nfl n ! ’ cVT AT (rhi I nrV I", I n I’I𔃿F𔃻 1 rnIbrrTnn 1 n 19 r (.T I 9 I 1 .. i’r"’r TF1 LIn’I~r I, ItiVsS En 1 OI1;VIa V Cn AV. f" I" I " c,’’’ 1

Fort Wayne, Muni, Indiana. Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F.

DTIC Science & Technology

1987-10-09

1-4 7 4R-S5 6.E S6 FETAL MEAN I DF I.REELS I I hIND N I .~ .? 1 9 .93.7 A.1 PcE 3 .1 .3 .213 9 .8 NI . . .3 . 1.6 P .9 ENE 1 ~ .2 1.3 .3 1.3 Ic. 7 L 5...11.2 3. 7 .9 22.R 13. 1 N 1 .1 2.6 .4 . 3 4 6. 7 9.6 NW I .5 2.2 1.1 .2 4.9 9.8 t: , 1.7 1.7 1.2 .1 6.5 p .6...1.2 . ,2 .0 12,7 II*- S .1 j1.9 6.1 0.2 .0 2.5 .1 21.A 1Z.8 bUW • . 1.2 2.1 I.p .5 .1 5. p 10.2 NW . 1.3 n .0 1.6 .3 .0 .2 9.7 NA .2 2.2 1, 3.3 ,2 .2 4,4

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2012 CFR

2012-01-01

...-126 .1 .001 Iodine-129 .1 .01 Iodine-131 .1 .001 Iodine-132 10 .1 Iodine-133 1 .01 Iodine-134 10 .1...-125 1 .01 Arsenic-73 10 .1 Arsenic-74 1 .01 Arsenic-76 1 .01 Arsenic-77 10 .1 Barium-131 10 .1 Barium... Cerium-144 .1 .001 Cesium-131 100 1. Cesium-134m 100 1. Cesium-134 .1 .001 Cesium-135 1 .01 Cesium-136 10...

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2014 CFR

2014-01-01

...-126 .1 .001 Iodine-129 .1 .01 Iodine-131 .1 .001 Iodine-132 10 .1 Iodine-133 1 .01 Iodine-134 10 .1...-125 1 .01 Arsenic-73 10 .1 Arsenic-74 1 .01 Arsenic-76 1 .01 Arsenic-77 10 .1 Barium-131 10 .1 Barium... Cerium-144 .1 .001 Cesium-131 100 1. Cesium-134m 100 1. Cesium-134 .1 .001 Cesium-135 1 .01 Cesium-136 10...

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2013 CFR

2013-01-01

...-126 .1 .001 Iodine-129 .1 .01 Iodine-131 .1 .001 Iodine-132 10 .1 Iodine-133 1 .01 Iodine-134 10 .1...-125 1 .01 Arsenic-73 10 .1 Arsenic-74 1 .01 Arsenic-76 1 .01 Arsenic-77 10 .1 Barium-131 10 .1 Barium... Cerium-144 .1 .001 Cesium-131 100 1. Cesium-134m 100 1. Cesium-134 .1 .001 Cesium-135 1 .01 Cesium-136 10...

26 CFR 1.1-1 - Income tax on individuals.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 1 2010-04-01 2010-04-01 true Income tax on individuals. 1.1-1 Section 1.1-1... and Surtaxes § 1.1-1 Income tax on individuals. (a) General rule. (1) Section 1 of the Code imposes an... taxable years beginning before January 1, 1970) see section 3. The tax imposed is upon taxable income...

26 CFR 1.1-1 - Income tax on individuals.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 1 2011-04-01 2009-04-01 true Income tax on individuals. 1.1-1 Section 1.1-1... and Surtaxes § 1.1-1 Income tax on individuals. (a) General rule. (1) Section 1 of the Code imposes an... taxable years beginning before January 1, 1970) see section 3. The tax imposed is upon taxable income...

26 CFR 1.1-1 - Income tax on individuals.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 1 2014-04-01 2013-04-01 true Income tax on individuals. 1.1-1 Section 1.1-1... and Surtaxes § 1.1-1 Income tax on individuals. (a) General rule. (1) Section 1 of the Code imposes an... taxable years beginning before January 1, 1970) see section 3. The tax imposed is upon taxable income...

26 CFR 1.1-1 - Income tax on individuals.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 1 2013-04-01 2013-04-01 false Income tax on individuals. 1.1-1 Section 1.1-1... and Surtaxes § 1.1-1 Income tax on individuals. (a) General rule. (1) Section 1 of the Code imposes an... taxable years beginning before January 1, 1970) see section 3. The tax imposed is upon taxable income...

26 CFR 1.1-1 - Income tax on individuals.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 1 2012-04-01 2012-04-01 false Income tax on individuals. 1.1-1 Section 1.1-1... and Surtaxes § 1.1-1 Income tax on individuals. (a) General rule. (1) Section 1 of the Code imposes an... taxable years beginning before January 1, 1970) see section 3. The tax imposed is upon taxable income...

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

DTIC Science & Technology

2015-09-02

China 1 (+0 +1) 1 Japan 1 1 Australia 1 1 Chile 1 1 Latvia 1 1 South Korea 1 1 South Africa 1 1 Argentina...Than Requested for FY 2013,” HSToday.us, May 10, 2012, accessed May 31, 2012, at http://www.hstoday.us/focused-topics/customs- immigration /single

Selected Manpower Statistics, Fiscal Year 1976.

DTIC Science & Technology

1977-05-01

T 411F 6 1, GR l:2 - 1.7 Total 30,659 3.6 625 1 1 8 ,:14. 4 .l 426 U.0 55T -.7 C01111MCLIT hl t-rY 147 4,233 1.1 F8t, L- 4 9 civilian J,117, 0C 1.5 6 0.7...7,,01 .. 4 ,2 1 m i 0 1,7 2 Total 55 0.1 , 8 ,5 I, 12 0.3 OOR, . ,1 M.i ,tar - - 12.14, L. CiolII I1,553,.W.’ 1" 7 . 7 . , To,..’.32 .1. NORTH8 CAOIN...8217 - - 15,241 1.1 Civla1 1, 25,O00 C 4 557, 1.4 172’ C.1 4,321’ 1.0 8 2.1 ,9 1.0 Total 6 . 2 0.1 17,4o 2.’ . 0." 24,013 1.1 YOR mllll ""r I., -~ 2 17

Detecting Age in Online Chat

DTIC Science & Technology

2009-09-01

spanks 1.000 2 2 fat. 1.000 2 2 awful 1.000 3 3 parties 1.000 3 3 canada? 1.000 3 3 tail? 1.000 2 2 once 1.000 2 2 thing. 1.000 3 3 gah 1.000 2 2 will...1.000 2 2 money 1.000 2 2 minutes 1.000 8 8 hmmmmmmmm 1.000 3 3 box 1.000 8 8 tank 1.000 2 2 ks 1.000 2 2 spanks 1.000 2 2 u? 1.000 17 17 jersey...thank you lol 1.000 2 2 i have another 1.000 2 2 u have to 1.000 4 4 <post> .action spanks 1.000 2 2 yes they do 1.000 2 2 <post> it will 1.000 2 2

12 CFR Appendix B to Subpart A of... - Appendix B to Subpart A of Part 327

Code of Federal Regulations, 2010 CFR

2010-01-01

... Converted value Standard & Poor's: AAA 1.00 AA+ 1.05 AA 1.15 AA− 1.30 A+ 1.50 A 1.80 A− 2.20 BBB+ 2.70 BBB or worse 3.00 Moody's: Aaa 1.00 Aa1 1.05 Aa2 1.15 Aa3 1.30 A1 1.50 A2 1.80 A3 2.20 Baa1 2.70 Baa2 or worse 3.00 Fitch's: AAA 1.00 AA+ 1.05 AA 1.15 AA− 1.30 A+ 1.50 A 1.80 A− 2.20 BBB+ 2.70 BBB or worse 3...

75 FR 74743 - Notice of Proposed Withdrawal Extension, Corrections to Existing Withdrawal, and Opportunity for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-01

.... 11 to 14, inclusive; Sec. 15, NE\\1/4\\, W\\1/2\\NW\\1/4\\, NW\\1/4\\SW\\1/4\\, and E\\1/2\\SE\\1/ 4\\; Sec. 19...\\; Secs. 23 to 34, inclusive; Sec. 35, NE\\1/4\\, NW\\1/4\\NW\\1/4\\, S\\1/2\\NW\\1/4\\, and S\\1/2\\; Sec. 36. T. 46 N., R. 22 E., Secs. 1 to 5, inclusive; Sec. 6, lots 1 and 2, S\\1/2\\NE\\1/4\\, E\\1/2\\SW\\1/4\\, and SE\\1...

Gaithersburg Nike Control and Launch Area Preliminary Assessment/Site Inspection Gaithersburg, Maryland

DTIC Science & Technology

1990-01-01

CYCLOPENTANE 1M7MEN 1-M4ETHYL-7- ( -METHYLETHYL) NAPHTHALENE 1MFLRE 1 -METHYL- 9H-FLUORENE INHP 1-NITROHEPTA14E MNONE 1-NITRO-2- OCTANONE 1OCTOL 1- OCTANOL ...iNuP 1-NITROHEPTANE 1NKCL 1.0 N POTASSIUM CHLORIDE 1NONE 1-NITRO-2- OCTANONE 1OCTOL 1-OCTAI4OL IPECHX 1-PROPENYLCYCLOHEXANE 1PNAP 1-PHENYLNAPHTHALENE...BROMO-1-CHLOROPROPANEI2B100L 2-BUTYL-1- OCTANOL 2B4MFU 2- (T-BUTYL) -4-METHYLFURAN 2CBMN 2-CHLOROBENZYLIDINEM-LONONITRILEI 2CECHO 2- (2-CYANOETHYL

Use of Monoclonal Antibodies to Study the Structural Basis of the Function of Nicotinic Acetylcholine Receptors on Electric Organ and Muscle and to Determine the Structure of Nicotinic Acetylcholine Receptors on Neurons

DTIC Science & Technology

1989-03-16

nucleus robustus archistriatalis 1 1 1 nucleus reticularis gigantocellularis 1 3 3 nucleus reticularis lateralis 1 3 3 nucleus ... reticularis pontis caudalis 1 1 3 nucleus reticularis parvocellularis 1 1 2 nucleus rotundus 1 1 1 nucleus tractus solitarii 1 3 3 nucleus semilunaris...Structure a-bungarotoxin mAb 35 inAb 270 nucleus accumbens 1 1 1 nucleus basalis 1 1 1 nucleus cerebelli intermedium 2 3 3

Fuel Hedging Task Group

DTIC Science & Technology

2004-03-01

Historical Volatility Task Group Objectives Process Observations Recommendations...Next Steps WTI Nymex Mth1 Close Historical Volatility Chart 0% 20% 40% 60% 80% 100% 120% 140% 160% 180% 1/ 29 /8 8 1/ 29 /8 9 1/ 29 /9 0 1/ 29 /9 1 1...29 /9 2 1/ 29 /9 3 1/ 29 /9 4 1/ 29 /9 5 1/ 29 /9 6 1/ 29 /9 7 1/ 29 /9 8 1/ 29 /9 9 1/ 29 /0 0 1/ 29 /0 1 1/ 29 /0 2 WTI Nymex Mth1 Close

49 CFR 172.522 - EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3... INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Placarding § 172.522 EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards. (a) Except for size and color, the EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3...

49 CFR 172.522 - EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3... INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Placarding § 172.522 EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards. (a) Except for size and color, the EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3...

40 CFR 180.615 - Amicarbazone; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-oxo-1H-1,2,4-triazole-1-carboxamide] and its metabolites DA amicarbazone [N-(1,1-dimethylethyl)-4,5-dihydro-3-(1-methylethyl)-5-oxo-1H-1,2,4-triazole-1-carboxamide] and iPr-2-OH DA amicarbazone [N-(1,1...-methylethyl)-5-oxo-1H-1,2,4-triazole-1-carboxamide] and its metabolites DA amicarbazone [N-(1,1-dimethylethyl...

DHU1 negatively regulates UV-B signaling via its direct interaction with COP1 and RUP1.

PubMed

Kim, Sang-Hoon; Kim, Hani; Chung, Sunglan; Lee, Jae-Hoon

2017-09-16

Although DWD HYPERSENSITIVE TO UV-B 1 (DHU1) is reported to be a negative regulator in UV-B mediated cellular responses, its detailed role in UV-B signaling is still elusive. To further understand the action mechanism of DHU1 in UV-B response, physical and genetic interactions of DHU1 with various UV-B signaling components were investigated. Yeast two hybrid assay results suggested that DHU1 directly interacts with COP1 and RUP1, implying a functional connection with both COP1 and RUP1. In spite of the physical association between DHU1 and COP1, loss of DHU1 did not affect protein stability of COP1. Epistatic analysis showed that the functional loss of both DHU1 and UVR8 leads to alleviation of UV-B hypersensitivity displayed in dhu1-1. Moreover, phenotypic studies with dhu1-1 cop1-6 and dhu1-1 hy5-215 revealed that COP1 and HY5 are epistatic to DHU1, indicating that UV-B hypersensitivity of dhu1-1 requires both COP1 and HY5. In the case of dhu1-1 rup1-1, UV-B responsiveness was similar to that of both dhu1-1 and rup1-1, implying that DHU1 and RUP1 are required for each other's function. Collectively, these results show that the role of DHU1 as a negative regulator in UV-B response may be derived from its direct interaction with COP1 by sequestering COP1 from the active UVR8-COP1 complex, resulting in a decrease in the COP1 population that positively participates in UV-B signaling together with UVR8. Furthermore, this inhibitory role of DHU1 in UV-B signaling is likely to be functionally connected to RUP1. This study will serve as a platform to further understand more detailed action mechanism of DHU1 in UV-B response and DHU1-mediated core UV-B signaling in Arabidopsis. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of education and income on cardiovascular outcomes: A systematic review and meta-analysis.

PubMed

Khaing, Win; Vallibhakara, Sakda A; Attia, John; McEvoy, Mark; Thakkinstian, Ammarin

2017-07-01

Objective Previous studies have reported discrepancy effects of education and income on cardiovascular diseases. This systematic review and meta-analysis was therefore conducted which aimed to summarize effects of education and income on cardiovascular diseases. Methods Studies were identified from Medline and Scopus until July 2016. Cohorts were eligible if they assessed associations between education/income and cardiovascular diseases, had at least one outcome including coronary artery diseases, cardiovascular events, strokes and cardiovascular deaths. A multivariate meta-analysis was applied to pool risk effects of these social determinants. Results Among 72 included cohorts, 39, 19, and 14 were studied in Europe, USA, and Asia. Pooled risk ratios of low and medium versus high education were 1.36 (95% confidence interval: 1.11-1.66) and 1.21 (1.06-1.40) for coronary artery diseases, 1.50 (1.17-1.92) and 1.27 (1.09-1.48) for cardiovascular events, 1.23 (1.06-1.43) and 1.17 (1.01-1.35) for strokes, and 1.39 (1.26-1.54) and 1.21 (1.12-1.30) for cardiovascular deaths. The effects of education on all cardiovascular diseases were still present in US and Europe settings, except in Asia this was present only for cardiovascular deaths. Effects of low and medium income versus high on these corresponding cardiovascular diseases were 1.49 (1.16-1.91) and 1.27 (1.10-1.47) for coronary artery diseases, 1.17 (0.96-1.44) and 1.05 (0.98-1.13) for cardiovascular events, 1.30 (0.99-1.72) and 1.24 (1.00-1.53) for strokes, and 1.76 (1.45-2.14) and 1.34 (1.17-1.54) for cardiovascular deaths. Conclusion Social determinants are risk factors of cardiovascular diseases in developed countries, although high heterogeneity in pooling. Data in Asia countries are still needed to update pooling.

Affine Equivalence of Quartic Monomial Rotation Symmetric Boolean Functions in Prime Power Dimension

DTIC Science & Technology

2015-01-27

the contribution to E(p`)(·) in this case is E(p`)1,5,7,11 ←− 1 2 (p`−1 − 1)(p` − 2p`−1 − 1) 2 + 1 3 (p`−1 − 1)(p`−1 − 2) 2 = (p`−1 − 1)(3p` − 4p `−1...remaining number of pairs (of class cardinality 8) is exactly (p`−s−1 − 1)(p`−s−1 − 2)− (p`−s−1 − 1) = p2`−2s−2 − 4p `−s−1 + 3. Thus, the contribution to E(p...of class C is E(p`)1,5,7,11 ←− `−2∑ s=1 ( p`−s−1 − 1 2 + p2`−2s−2 − 4p `−s−1 + 3 8 ) = `−2∑ s=1 p2`−2s−2 − 1 8 = p2`−2 − 1 8(p2 − 1) − `− 1 8

CCAR1/CoCoA pair-mediated recruitment of the Mediator defines a novel pathway for GATA1 function.

PubMed

Mizuta, Shumpei; Minami, Tomoya; Fujita, Haruka; Kaminaga, Chihiro; Matsui, Keiji; Ishino, Ruri; Fujita, Azusa; Oda, Kasumi; Kawai, Asami; Hasegawa, Natsumi; Urahama, Norinaga; Roeder, Robert G; Ito, Mitsuhiro

2014-01-01

The MED1 subunit of the Mediator transcriptional coregulator complex coactivates GATA1 and induces erythropoiesis. Here, we show the dual mechanism of GATA1- and MED1-mediated transcription. MED1 expression levels in K562 erythroleukemia cells paralleled the levels of GATA1-targeted gene transcription and erythroid differentiation. An N-terminal fragment of MED1, MED1(1-602), which is incapable of interacting with GATA1, enhanced GATA1-targeted gene transcription and erythroid differentiation, and introduction of MED1(1-602) into Med1(-/-) mouse embryonic fibroblasts (MEFs) partially rescued GATA1-mediated transcription. The C-terminal zinc-finger domain of GATA1 interacts with the MED1(1-602)-interacting coactivator CCAR1, CoCoA and MED1(681-715). CCAR1 and CoCoA synergistically enhanced GATA1-mediated transcription from the γ-globin promoter in MEFs. Recombinant GATA1, CCAR1, CoCoA and MED1(1-602) formed a complex in vitro, and GATA1, CCAR1, CoCoA and MED1 were recruited to the γ-globin promoter in K562 cells during erythroid differentiation. Therefore, in addition to the direct interaction between GATA1 and MED1, CoCoA and CCAR1 appear to relay the GATA1 signal to MED1, and multiple modes of the GATA1-MED1 axis may help to fine-tune GATA1 function during GATA1-mediated homeostasis events. © 2013 The Authors Genes to Cells © 2013 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

Generation of Bayesian prediction models for OATP-mediated drug-drug interactions based on inhibition screen of OATP1B1, OATP1B1∗15 and OATP1B3.

PubMed

van de Steeg, E; Venhorst, J; Jansen, H T; Nooijen, I H G; DeGroot, J; Wortelboer, H M; Vlaming, M L H

2015-04-05

Human organic anion-transporting polypeptide 1B1 (OATP1B1) and OATP1B3 are important hepatic uptake transporters. Early assessment of OATP1B1/1B3-mediated drug-drug interactions (DDIs) is therefore important for successful drug development. A promising approach for early screening and prediction of DDIs is computational modeling. In this study we aimed to generate a rapid, single Bayesian prediction model for OATP1B1, OATP1B1∗15 and OATP1B3 inhibition. Besides our previously generated HEK-OATP1B1 and HEK-OATP1B1∗15 cells, we now generated and characterized HEK-OATP1B3 cells. Using these cell lines we investigated the inhibitory potential of 640 FDA-approved drugs from a commercial library (10μM) on the uptake of [(3)H]-estradiol-17β-d-glucuronide (1μM) by OATP1B1, OATP1B1∗15, and OATP1B3. Using a cut-off of ⩾60% inhibition, 8% and 7% of the 640 drugs were potent OATP1B1 and OATP1B1∗15 inhibitors, respectively. Only 1% of the tested drugs significantly inhibited OATP1B3, which was not sufficient for Bayesian modeling. Modeling of OATP1B1 and OATP1B1∗15 inhibition revealed that presence of conjugated systems and (hetero)cycles with acceptor/donor atoms in- or outside the ring enhance the probability of a molecule binding these transporters. The overall performance of the model for OATP1B1 and OATP1B1∗15 was ⩾80%, including evaluation with a true external test set. Our Bayesian classification model thus represents a fast, inexpensive and robust means of assessing potential binding of new chemical entities to OATP1B1 and OATP1B1∗15. As such, this model may be used to rank compounds early in the drug development process, helping to avoid adverse effects in a later stage due to inhibition of OATP1B1 and/or OATP1B1∗15. Copyright © 2015 Elsevier B.V. All rights reserved.

Word Criticality Analysis. MOS: 67U. Skill Levels 1 & 2.

DTIC Science & Technology

1981-09-01

8217C~E 1651 47p 2 i Pr’ k 9901 22. u’ lt.I V% p 1 ’.2.2 125.1 I SC 0 1dept OW Met33, 2 5I2?.~ Viol 2 s:f STT3" 1601 2 S,1 -"𔃾 )vp 3 2 S F3.L I,,# I Io...97,1 91.1 08. 2 50cp? 14603 132 1 54i 1 6.2 156, P 3 C ,’TICAL 50 I’ll 20.4 8.5 󈨋 04 19𔃼 11.3 16,9 9,1 3 C f"IC .L - AGENT 1(),3 3 Cf...stal Viol , 94.1 ?)#1 129,1 lir7*2 llb0a ? Woo 1#1 1540.1 15301 120.1 150.1 173.1 11201 83.1 $)at $301 105.1 1,34,1, Ilil 1601 les 17L01U7151~ 1 7001

Installation Restoration Program. Site Investigation Report. Revision 4. Volume 2: Appendix B through Appendix E. 155th Air Refueling Group, Nebraska Air National Guard, Lincoln Municipal Airport, Lincoln, Nebraska.

DTIC Science & Technology

1995-04-01

1 50 I 15.0 - 40.09 of mass 95 1 20.5 1 75 1 30.0 - 60.0% of mass 95 1 41.5 95 1 Base peak , 100% relative abundance 1100.0 1 96 1 5.0 - 9.0% of mass...2.0% of mass 69 1 .0_( 1 127 1 40.0 - 60.0% of mass 198 141.7- I 197 1 Less than 1.0% of mass 198 1 .0 1 198 1 Base peak , i00% relative abundance...48.3 1 701 Less than 2.0% of mass 69 1 .0_(. .( I 127 1 40.0 - 60.0% of mass 198 1 40.2 I 197 1 Less than 1.00 of mass 198 1 .0 1 198 1 Base peak

The Use of a Selenium-Peptide to Specifically Inactivate Yersinia pestis

DTIC Science & Technology

2005-10-01

Control 2 (F1 Antibody+Anti-F1 Antibody) 2ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab 1ug/ mlF1 Ab+1011 Phage+Anti-F1 Antibody .5ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab...25ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab .125ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab .0625ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab .03125ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab...0156ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab .0078ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab .0039ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab .00195ug/ mlF1 Ab+1011 Phage+Anti-F1 Ab

Process Design and Cost Estimating Algorithms for the Computer Assisted Procedure for Design and Evaluation of Wastewater Treatment Systems (CAPDET).

DTIC Science & Technology

1982-01-01

mg/l. 2.1.9.1.3.3 Nitrogen, I Mg 1. 2.1.9.1.3.4 Phosphorus (total and soluble), ag/l. 2.1.9.1.3.5 Oils and greases, mg/l. 2.1.9.1.3.6 Heavy metals , mg...greases, mg/I. 2.1.10.1.3.6 Heavy metals , m/l. 2.1.10.1.3.7 Toxic or special characteristics (e.g., phenols), mg/I. 2.1.10.1.3.8 Temperature, OF or °C...1 mg/l. 2.1.11.1.3.4 Phosphorus (total and soluble), mg/I. 2.1.11.1.3.5 Oils and greases, mgl. 2.1.11.1.3.6 Heavy metals , mg/l. 2.1.11.1.3.7 Toxic or

The effects of pulmonary diseases on histologic types of lung cancer in both sexes: a population-based study in Taiwan.

PubMed

Huang, Jing-Yang; Jian, Zhi-Hong; Nfor, Oswald Ndi; Ku, Wen-Yuan; Ko, Pei-Chieh; Lung, Chia-Chi; Ho, Chien-Chang; Pan, Hui-Hsien; Huang, Chieh-Ying; Liang, Yu-Chiu; Liaw, Yung-Po

2015-11-02

The associations between pulmonary diseases (asthma, chronic obstructive pulmonary disease [COPD], and tuberculosis [TB]) and subsequent lung cancer risk have been reported, but few studies have investigated the association with different histologic types of lung cancer. Patients newly diagnosed with lung cancer from 2004 to 2008 were identified from the National Health Insurance Research Database in Taiwan. Histologic types of lung cancer were further confirmed using the Taiwan Cancer Registry Database. Cox proportional hazards regression was used to calculate the hazard ratio (HR) of asthma, COPD, and TB and to estimate the risk of specific types of lung cancer. During the study period, 32,759 cases of lung cancer were identified from 15,219,024 insurants aged 20 years and older. In men and women, the adjusted HR estimates of squamous cell carcinoma were respectively 1.37 (95 % confidence interval [CI], 1.21-1.54) and 2.10 (95 % CI, 1.36-3.23) for TB, 1.52 (95 % CI, 1.42-1.64) and 1.50 (95 % CI, 1.21-1.85) for asthma, and 1.66 (95 % CI, 1.56-1.76) and 1.44 (95 % CI, 1.19-1.74) for COPD. Similarly, the adjusted HR estimates of adenocarcinoma were respectively 1.33 (95 % CI, 1.19-1.50) and 1.86 (95 % CI, 1.57-2.19) for TB, 1.13 (95 % CI, 1.05-1.21) and 1.18 (95 % CI, 1.09-1.28) for asthma, and 1.50 (95 % CI, 1.42-1.59) and 1.33 (95 % CI, 1.25-1.42) for COPD. The HRs of small cell carcinoma were respectively 1.24 (95 % CI, 1.01-1.52) and 2.23 (95 % CI, 1.17-4.25) for TB, 1.51 (95 % CI, 1.35-1.69) and 1.63 (95 % CI, 1.16-2.27) for asthma, and 1.39 (95 % CI, 1.26-1.53) and 1.78 (95 % CI, 1.33-2.39) for COPD. Asthma, COPD, and TB were associated with an increased risk of all major subtypes of lung cancer. The risk was the highest among women with TB.

40 CFR 721.10336 - Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-oxo-2-propen-1-yl)-.omega.-([1,1â²-biphenyl]-2-yloxy)-. 721.10336 Section 721.10336 Protection of...-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-. (a) Chemical substance and...), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)- (PMN P-04-1; CAS No. 72009-86-0) is...

40 CFR 721.10336 - Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-oxo-2-propen-1-yl)-.omega.-([1,1â²-biphenyl]-2-yloxy)-. 721.10336 Section 721.10336 Protection of...-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-. (a) Chemical substance and...), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)- (PMN P-04-1; CAS No. 72009-86-0) is...

40 CFR 721.10336 - Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-oxo-2-propen-1-yl)-.omega.-([1,1â²-biphenyl]-2-yloxy)-. 721.10336 Section 721.10336 Protection of...-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-. (a) Chemical substance and...), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)- (PMN P-04-1; CAS No. 72009-86-0) is...

76 FR 61054 - Approval and Promulgation of State Implementation Plans; State of Colorado Regulation Number 3...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-03

....aa; II.D.1.bb; II.D.1.kk; II.D.1.nn; II.D.1.oo; II.D.1.aaa; II.D.1.bbb; II.D.1.ccc; II.D.1.fff; II.D...; II.D.1.y; II.D.1.aa; II.D.1.bb; II.D.1.kk; II.D.1.nn; II.D.1.oo; II.D.1.aaa; II.D.1.bbb; II.D.1.ccc...

Co-expression of human cytochrome P4501A1 (CYP1A1) variants and human NADPH-cytochrome P450 reductase in the baculovirus/insect cell system.

PubMed

Schwarz, D; Kisselev, P; Honeck, H; Cascorbi, I; Schunck, W H; Roots, I

2001-06-01

1. Three human cytochrome P4501A1 (CYP1A1) variants, wild-type (CYP1A1.1), CYP1A1.2 (1462V) and CYP1A1.4 (T461N), were co-expressed with human NADPH-P450 reductase (OR) in Spodoptera frugiperda (Sf9) insect cells by baculovirus co-infection to elaborate a suitable system for studying the role of CYPA1 polymorphism in the metabolism of exogenous and endogenous substrates. 2. A wide range of conditions was examined to optimize co-expression with regard to such parameters as relative multiplicity of infection (MOI), time of harvest, haem precursor supplementation and post-translational stabilization. tinder optimized conditions, almost identical expression levels and molar OR/CYP1A1 ratios (20:1) were attained for all CYP1A1 variants. 3. Microsomes isolated from co-infected cells demonstrated ethoxyresorufin deethlylase activities (nmol/min(-1) nmol(-1) CYP1A1) of 16.0 (CYP1A1.1), 20.5 (CYP1A1.2) and 22.5 (CYP1A1.4). Pentoxyresorufin was dealkylated approximately 10-20 times slower with all enzyme variants. 4. All three CYP1A1 variants were active in metabolizing the precarcinogen benzo[a]pyrene (B[a]P), with wild-type enzyme showing the highest activity, followed by CYP1A1.4 (60%) and CYP1A1.2 (40%). Each variant produced all major metabolites including B[a]P-7,8-dihydrodiol, the precursor of the ultimate carcinogenic species. 5. These studies demonstrate that the baculovirus-mediated co-expression-by-co-infection approach all CYP1A1 variants yields functionally active enzyme systems with similar molar OR/CYP1A1 ratios, thus providing suitable preconditions to examine the metabolism of and environmental chemicals by the different CY1A1 variants.

Word Criticality Analysis. MOS: 31M. Skill Levels 1 & 2.

DTIC Science & Technology

1981-09-01

1401 142.2 1igal 117.1 111#1 1V3,1 Mal. 92,2 82#~1 d1𔃻 60*1 los1 .54*1 -’,01 6,1 𔃻’ ’.0,1 24,1 12.14 9P4 u.S U 6p2 3*4 2,4 IAN/GRC-103 28002 10601...62.1 59,2 scot 4SO3 4.1 ~10 31#1 24,! los1 2 YELLrw 3.4 381 4.2Z 9*1 363,1 3 . 6, 0, 2 ZEPOF0 37214 ~) 3 bit 238𔃻 803 3 AUP 717#1 189𔃻 14,2 l0s2

40 CFR 180.410 - Triadimefon; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... residues of the fungicide triadimefon, 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone, and triadimenol, β-(4-chlorophenoxy)-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol, expressed... of the fungicide triadimefon, 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone...

Medical Surveillance Monthly Report (MSMR). Volume 2, Number 1, January 1996

DTIC Science & Technology

1996-01-01

Lymphogranuloma Venereum (d) Syphilis unspec. (e) Syph, tertiary (f) Syph, congenital MSMRVol. 02 / No. 01 7 Continued from page 3 thermia. Details of cold...Lyme disease 1 1 1 1 1 3 3 1 - 1 3 3 12 Lymphogranuloma Vnrm 1 2 1 1 4 1 - - 1 4 1 - 11 (Continued) MSMRVol. 02 / No. 01 15 TABLE S1. Notifiable

Characterization and formation of σ/γ interface in Ni-based single crystal superalloys

NASA Astrophysics Data System (ADS)

Ma, Shiyu; Zhang, Jianxin; Li, Xueqiao; Mao, Shengcheng

2017-11-01

High-resolution transmission electron microscopy was used to study interfacial characteristics between the plate-shaped σ phase and the γ phase in a Ni-based single crystal superalloy. The atomic structure of the σ/γ interface constituted by steps was presented. However, the HRTEM micrograph of σ phase is not almost identical with the veritable atomic arrangement of σ phase on the same zone axis. The image formation of HRTEM relies on phase contrast, instead of the amplification of the atomic arrangement. From the simulated HRTEM images, the approximate defocus and thickness of the sample can be got as  -3 nm and 6 nm. σ phase has the following crystallographic orientations relations with γ matrix: [0 0 1] γ //[1 1 2] σ , (1 1 0) γ //(1   -1 0) σ , (-1 1 0) γ //(1 1   -1) σ , which can be proved by the stereographic projection. The interfacial steps are made up by (1 1 0) γ and (-1 1 0) γ or (1   -1 0) σ and (1 1   -1) σ . In the interface steps, the length of (-1 1 0) γ //(1 1   -1) σ is longer than (1 1 0) γ //(1   -1 0) σ , which is caused by that distortion factor of (-1 1 0) γ //(1 1   -1)σ is much smaller than that of (1 1 0) γ //(1   -1 0) σ .

Atlantic City, New Jersey, Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F.

DTIC Science & Technology

1981-11-23

1.2 1.0 2.5 9.5 SE 1.2 o6 .1 ,1 2.1 6*5 ___- 3 2.1 ISO 3. 9*7 S7 7 3,0 593 1.5 .1 IC.6 I 1 2 ssw Aa6 1.9 1.2 W 4.1 11.C sw 1.9 1.5 ,4 3.8 _12_, L Sw...1.8 9.5 *8 2 9 4a0 __ _ . I 11s5 .1 .7 1.3 ., .1, 2.4 8.4 SE 1.0 1.5 .7 .3 2 8.2 -Smt o1 Ib 1s9 IS$ 03 4.7 10.5 - s el .6 2.2jL 3.8 ISO 7. 6 1.8a SSW a...LL .I 5.7 5*S NmW .6 5.6 ISO 63 7o4* 5*4 VAUmL CALM 23.0 r-1 1 ,1.9 126.1 A’m I&. 0 . . TOTAL NUMn OF oUIVATONS 720 USAFETAC P 0.8.5 (OL-A) mvious

Word Criticality Analysis. MOS: 16B. Skill Levels 1 & 2

DTIC Science & Technology

1981-09-01

43* 2 UI3L, 29.1 2 §CT;:It’:iLL 1.12 2 ACCA 97.1 55.1 43.1 2 2 4,CITUI L 1.1 521 21l 9i 9 P ~ 1.2 2 hA~T)U h 24.1 10-.2 58.1 2.1. 2 A.;aifl U95. 2591...2 17 SOE 16.1 3.tl z J KS ’ f1 . 942.1 4e1 I v/ k Y1 MCS WOR LIT sy rtE AT SM U-2 AG P~~~- .s...:’<.- 14o -!2 7 2~ LVRI4RO LIST 66Y 22G1 140 *17142...71. 4 d1LLY 6? f1 4 NJ51 4l 22#1, 63.1 13.?2 5.2 17,1l 16.1 4 C tM; 4 Cx:v 1::CE. 1 1 7.2 4 Ci ’IF 37. 4 C t .C V1 E It C~C-’ 4:: I! D. 4 C0,; .) 2

Crystal orientation of monoclinic β-Ga2O3 thin films formed on cubic MgO substrates with a γ-Ga2O3 interfacial layer

NASA Astrophysics Data System (ADS)

Nakagomi, Shinji; Kokubun, Yoshihiro

2017-12-01

The crystal orientation relationship between β-Ga2O3 and MgO in β-Ga2O3 thin films prepared on (1 0 0), (1 1 1), and (1 1 0) MgO substrates was investigated by X-ray diffraction measurements and cross-sectional transmission electron microscopy images. The γ-Ga2O3 interfacial layer was present between β-Ga2O3 and MgO acted as a buffer to connect β-Ga2O3 on MgO. The following conditions were satisfied under each case: β-Ga2O3 (1 0 0)||MgO (1 0 0) and β-Ga2O3 [0 0 1]||MgO 〈0 1 1〉 for the formation of β-Ga2O3 on (1 0 0) MgO, and β-Ga2O3 (2 bar 0 1)||MgO (1 1 1) for the formation of β-Ga2O3 on (1 1 1) MgO, as well as each condition of β-Ga2O3 [0 1 0] (1 0 0)||MgO [ 1 bar 1 0 ] (0 0 1), β-Ga2O3 [0 1 0] (1 0 0)||MgO [ 0 1 bar 1 ] (1 0 0), and β-Ga2O3 [0 1 0] (1 0 0)||MgO [ 1 0 1 bar ] (0 1 0). β-Ga2O3 (1 bar 0 2)||MgO(1 1 0) and β-Ga2O3 [0 1 0] ⊥ MgO [0 0 1] for β-Ga2O3 formed on (1 1 0) MgO. The β-Ga2O3 formed on (1 1 1) MgO at 800 °C exhibited a threefold structure. The β-Ga2O3 formed on (1 1 0) MgO had a twofold structure but different by 90° from the result reported previously.

Joint Services Electronics Program.

DTIC Science & Technology

1984-06-01

INTEGRATION •6 1.1 Properties of Materials: Application of Channeling Radiation to a Study of the Properties 6 of Materials 1.1.1 Scientific...Objectives 6 1.1.2 Progress 7 1.1.2.1 Channeling Radiation from Si with an Oxygen Platelet Impurity 7 1.1.2.2 Calculated Potentials and Eigenvalues in GaAs...AIGaAs, and AlAs 11 1.1.2.3 Low Temperature Channeling Radiation 14 1.1.2.4 Electron Channeling Radiation from LiH and UD 14 1.1.2.5 12.6 MeV Electron

40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2012 CFR

2012-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...

40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2010 CFR

2010-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...

40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2014 CFR

2014-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...

40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2013 CFR

2013-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...

40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2011 CFR

2011-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...

Czechoslovakia. Section 23. Weather and Climate

DTIC Science & Technology

1966-07-01

0R RV7 918 l10(96 884 95b 99’ lll0 1O.400 * I 01 921103 1132’ 106 13.900 of 0 1028 1210 1301 1160 4.800 0 1 1 A 14 1 3 1 .0 13 6 2 WIND SPEED SCALL ...8-7 Eustern Mountalnst Kasprowy Wieroh**,,, 1900 a 8 1 * 1 * 0 1 1 1 1 4 17 7-8 Lotnniok$ ttt ....... 1000 2 2 3 2 1 1 1 1 1 8 1 4 19 5-7 Sia

Sequential Seasonal H1N1 Influenza Virus Infections Protect Ferrets against Novel 2009 H1N1 Influenza Virus

PubMed Central

Carter, Donald M.; Bloom, Chalise E.; Nascimento, Eduardo J. M.; Marques, Ernesto T. A.; Craigo, Jodi K.; Cherry, Joshua L.; Lipman, David J.

2013-01-01

Individuals <60 years of age had the lowest incidence of infection, with ∼25% of these people having preexisting, cross-reactive antibodies to novel 2009 H1N1 influenza. Many people >60 years old also had preexisting antibodies to novel H1N1. These observations are puzzling because the seasonal H1N1 viruses circulating during the last 60 years were not antigenically similar to novel H1N1. We therefore hypothesized that a sequence of exposures to antigenically different seasonal H1N1 viruses can elicit an antibody response that protects against novel 2009 H1N1. Ferrets were preinfected with seasonal H1N1 viruses and assessed for cross-reactive antibodies to novel H1N1. Serum from infected ferrets was assayed for cross-reactivity to both seasonal and novel 2009 H1N1 strains. These results were compared to those of ferrets that were sequentially infected with H1N1 viruses isolated prior to 1957 or more-recently isolated viruses. Following seroconversion, ferrets were challenged with novel H1N1 influenza virus and assessed for viral titers in the nasal wash, morbidity, and mortality. There was no hemagglutination inhibition (HAI) cross-reactivity in ferrets infected with any single seasonal H1N1 influenza viruses, with limited protection to challenge. However, sequential H1N1 influenza infections reduced the incidence of disease and elicited cross-reactive antibodies to novel H1N1 isolates. The amount and duration of virus shedding and the frequency of transmission following novel H1N1 challenge were reduced. Exposure to multiple seasonal H1N1 influenza viruses, and not to any single H1N1 influenza virus, elicits a breadth of antibodies that neutralize novel H1N1 even though the host was never exposed to the novel H1N1 influenza viruses. PMID:23115287

Chemical characterization of milk oligosaccharides of the eastern quoll (Dasyurus viverrinus).

PubMed

Urashima, Tadasu; Sun, Yiliang; Fukuda, Kenji; Hirayama, Kentaro; Taufik, Epi; Nakamura, Tadashi; Saito, Tadao; Merchant, Jim; Green, Brian; Messer, Michael

2015-08-01

Structural characterizations of marsupial milk oligosaccharides have been performed in four species to date: the tammar wallaby (Macropus eugenii), the red kangaroo (Macropus rufus), the koala (Phascolarctos cinereus) and the common brushtail possum (Trichosurus vulpecula). To clarify the homology and heterogeneity of milk oligosaccharides among marsupials, the oligosaccharides in the carbohydrate fraction of eastern quoll milk were characterized in this study. Neutral and acidic oligosaccharides were separated and characterized by (1)H-nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The structures of the neutral oligosaccharides were Gal(β1-3)Gal(β1-4)Glc (3'-galactosyllactose), Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc (3",3'-digalactosyllactose), Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-novopentaose I), Gal(β1-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (galactosyl lacto-N-novopentaose I), Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)Gal(β1-4)Glc (galactosyl lacto-N-novopentaose II), Gal(β1-3)[Gal(β1-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (galactosyl lacto-N-novopentaose III) and Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-novooctaose). The structures of the acidic oligosaccharides detected are Neu5Ac(α2-3)Gal(β1-4)Glc (3'-sialyllactose), Gal(β1-3)(O-3-sulfate)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-novopentaose I sulfate a), Gal(β1-3)[Gal(β1-4)(O-3-sulfate)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-novopentaose I sulfate b), Neu5Ac(α2-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose a), Gal(β1-3)[Neu5Ac(α2-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose c), Neu5Ac(α2-3) Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, and Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc with an α(2-3) Neu5Ac linked to β(1-4)Gal residue of either branch of Gal(β1-4)GlcNAc(β1-6) units. The most predominant oligosaccharides in the carbohydrate fraction of mid-lactation milk were found to be lacto-N-novopentaose I and lacto-N-novooctaose, i.e., branched oligosaccharides that contain N-acetylglucosamine. The predominance of these branched oligosaccharides, rather than of a series of linear β(1-3) linked galacto oligosaccharides, appears to be the main feature of the eastern quoll milk oligosaccharides that differentiates them from those of the tammar wallaby and the brushtail possum.

Design Document for the Moods Data Management System (MDMS) Version 1.0

DTIC Science & Technology

1994-08-01

1 1.3 Document Overview ... . . . . . . . . . . . . . . . . . . . . 1 2 RERENCED DOCUMENTS .................... 2 3 PRELIM[INARY DESIGN... 3 3.1.1.1 CSC-: Grpical User Interfce(GUI).......... 3 3.1.112 CSC-2: Data Management Module (DMM) .................. 4 3.1.1.3 CSC- 3 : Data...5 3.1.1.6 GUI-DMM (CSC-1ICSC-2) internal interface................5 3.1.1.7 GUI-DAM (CSC-1/CSC- 3 ) Internal Interface................5

40 CFR 180.312 - 4-Aminopyridine; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... million Expiration/Revocation Date Corn, field, forage 0.1 1/15/06 Corn, field, grain 0.1 1/15/06 Corn, field, stover 0.1 1/15/06 Corn, pop, grain 0.1 1/15/06 Corn, pop, stover 0.1 1/15/06 Corn, sweet, forage 0.1 1/15/06 Corn, sweet, kernel plus cob with husks removed 0.1 1/15/06 Corn, sweet, stover 0.1 1/15...

40 CFR 372.65 - Chemicals and chemical categories to which this part applies.

Code of Federal Regulations, 2014 CFR

2014-07-01

...,3H)-pyrimidinedione) 314-40-9 1/1/95 Bromacil, lithium salt [2,4-(1H,3H)-Pyrimidinedione, 5-bromo-6-methyl-3-(1-methylpropyl), lithium salt] 53404-19-6 1/1/95 Bromine 7726-95-6 1/1/95 1-Bromo-1....alpha.,6.beta.)-] 58-89-9 1/1/87 Linuron 330-55-2 1/1/95 Lithium carbonate 554-13-2 1/1/95 Malathion 121...

40 CFR 372.65 - Chemicals and chemical categories to which this part applies.

Code of Federal Regulations, 2013 CFR

2013-07-01

...,3H)-pyrimidinedione) 314-40-9 1/1/95 Bromacil, lithium salt [2,4-(1H,3H)-Pyrimidinedione, 5-bromo-6-methyl-3-(1-methylpropyl), lithium salt] 53404-19-6 1/1/95 Bromine 7726-95-6 1/1/95 1-Bromo-1....alpha.,6.beta.)-] 58-89-9 1/1/87 Linuron 330-55-2 1/1/95 Lithium carbonate 554-13-2 1/1/95 Malathion 121...

40 CFR 372.65 - Chemicals and chemical categories to which this part applies.

Code of Federal Regulations, 2012 CFR

2012-07-01

...,3H)-pyrimidinedione) 314-40-9 1/1/95 Bromacil, lithium salt [2,4-(1H,3H)-Pyrimidinedione, 5-bromo-6-methyl-3-(1-methylpropyl), lithium salt] 53404-19-6 1/1/95 Bromine 7726-95-6 1/1/95 1-Bromo-1....alpha.,6.beta.)-] 58-89-9 1/1/87 Linuron 330-55-2 1/1/95 Lithium carbonate 554-13-2 1/1/95 Malathion 121...

Soluble vascular endothelial growth factor (VEGF) receptor-1 inhibits migration of human monocytic THP-1 cells in response to VEGF.

PubMed

Zhu, Cansheng; Xiong, Zhaojun; Chen, Xiaohong; Lu, Zhengqi; Zhou, Guoyu; Wang, Dunjing; Bao, Jian; Hu, Xueqiang

2011-08-01

We aimed to investigate the regulation and contribution of vascular endothelial growth factor (VEGF) and sFlt-1(1-3) to human monocytic THP-1 migration. Ad-sFlt-1/FLAG, a recombinant adenovirus carrying the human sFlt-1(1-3) (the first three extracellular domains of FLT-1, the hVEGF receptor-1) gene, was constructed. L929 cells were infected with Ad-sFlt-1/FLAG and the expression of sFlt-1 was detected by immunofluorescent assay and ELISA. Corning(®) Transwell(®) Filter Inserts containing polyethylene terephthalate (PET) membranes with pore sizes of 3 μm were used as an experimental model to simulate THP-1 migration. Five VEGF concentrations (0, 0.1, 1, 10 and 100 ng/ml), four concentrations of sFlt-1(1-3)/FLAG expression supernatants (0.1, 1, 10 and 100 ng/ml), and monocyte chemoattractant protein-1 (MCP-1, 10 ng/ml) were used to test the ability of THP-1 cells to migrate through PET membranes. The sFlt-1(1-3) gene was successfully recombined into Ad-sFlt-1/FLAG. sFlt-1(1-3) was expressed in L929 cells transfected with Ad-sFlt-1/FLAG. THP-1 cell migration increased with increasing concentrations of VEGF, while cell migration decreased with increasing concentrations of sFlt1(1-3)/FLAG. sFlt1(1-3)/FLAG had no effect on MCP-1-induced cell migration. This study demonstrated that VEGF is able to elicit a migratory response in THP-1 cells, and that sFlt-1(1-3) is an effective inhibitor of THP-1 migration towards VEGF.

The Structure and Infrastructure of Chinese Science and Technology

DTIC Science & Technology

2006-01-01

materi 2.4%, charg.discharg 2.2%, mah 2.0%, lifepo4 2.0%, charg 1.7%, composit 1.3%, oxid 1.2%, discharg.capac 1.1%, licoo2 1.1...charg.discharg 2.2%, mah 2.0%, lifepo4 2.0%, charg 1.7%, composit 1.3%, oxid 1.2%, discharg.capac 1.1%, licoo2 1.1%, cathod.materi 1.0%, electrod

75 FR 33310 - Agency Information Collection Activities: Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-11

... Analysis Form 1,034 1 1,034 5.0 5,170 Community Characteristics...... 1,034 1 1,034 1.0 1,034 Health Care Plan (Competing)... 800 1 1,034 4.0 4,136 Health Care Plan (Non- 1,034 1 1,034 2.0 2,068 Competing) Business Plan (Competing)...... 800 1 1,034 4.0 4,136 [[Page 33311

Conditional Mesenchymal Disruption of Pkd1 Results in Osteopenia and Polycystic Kidney Disease

PubMed Central

Cao, Li; David, Valentin; Quarles, Leigh Darryl

2012-01-01

Conditional deletion of Pkd1 in osteoblasts using either Osteocalcin(Oc)-Cre or Dmp1-Cre results in defective osteoblast-mediated postnatal bone formation and osteopenia. Pkd1 is also expressed in undifferentiated mesenchyme that gives rise to the osteoblast lineage. To examine the effects of Pkd1 on prenatal osteoblast development, we crossed Pkd1 flox/flox and Col1a1(3.6)-Cre mice, which has been used to achieve selective inactivation of Pkd1 earlier in the osteoblast lineage. Control Pkd1 flox/flox and Pkd1 flox/+, heterozygous Col1a1(3.6)-Cre;Pkd1 flox/+ and Pkd1 flox/null, and homozygous Col1a1(3.6)-Cre;Pkd1 flox/flox and Col1a1(3.6)-Cre;Pkd1 flox/null mice were analyzed at ages ranging from E14.5 to 8-weeks-old. Newborn Col1a1(3.6)-Cre;Pkd1 flox/null mice exhibited defective skeletogenesis in association with a greater reduction in Pkd1 expression in bone. Conditional Col1a1(3.6)-Cre;Pkd1 flox/+ and Col1a1(3.6)-Cre;Pkd1 flox/flox mice displayed a gene dose-dependent decrease in bone formation and increase in marrow fat at 6 weeks of age. Bone marrow stromal cell and primary osteoblast cultures from homozygous Col1a1(3.6)-Cre;Pkd1 flox/flox mice showed increased proliferation, impaired osteoblast development and enhanced adipogenesis ex vivo. Unexpectedly, we found evidence for Col1a1(3.6)-Cre mediated deletion of Pkd1 in extraskeletal tissues in Col1a1(3.6)-Cre;Pkd1 flox/flox mice. Deletion of Pkd1 in mesenchymal precursors resulted in pancreatic and renal, but not hepatic, cyst formation. The non-lethality of Col1a1(3.6)-Cre;Pkd1 flox/flox mice establishes a new model to study abnormalities in bone development and cyst formation in pancreas and kidney caused by Pkd1 gene inactivation. PMID:23029375

46 CFR 133.175 - Survival craft and rescue boat equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... line 1 2 1 2 15 Instruction card 1 1 17 Knife 1,3 1 1 1 1 18 Ladder 1 1 19 Mirror, signalling 1 1 20... Not required for inflated or rigid-inflated rescue boats. 3 A hatchet counts towards this requirement...

Neighborhood Poverty and 9-1-1 Ambulance Contacts.

PubMed

Seim, Josh; English, Joshua; Sporer, Karl

2017-01-01

Neighborhood poverty is positively associated with frequency of 9-1-1 ambulance utilization, but it is unclear whether this association remains significant when accounting for variations in the severities and types of ambulance contacts. We merged EMS ambulance contact records in a single California county (n = 88,027) with data from the American Community Survey at the census tract level (n = 300). Using tract as a proxy for neighborhood and negative binomial regression as an analytical tool, we predicted 16 outcomes: any ambulance contacts, ambulance contacts stratified by three intervention severities, and ambulance contacts varied by 12 primary impression categories. For each model, we estimated the incident rate ratios for 10 percentage point increases in tract-level poverty while controlling for geographic patterns in race, citizenship, gender, age, emergency department proximity, population density, and population size. Our study produced three major findings. First, tract-level poverty was positively associated with ambulance contacts (incident rate ratio [IRR] 1.45; 95% confidence interval [CI] 1.34 to 1.57). Second, poverty was positively associated with low severity contacts (IRR 1.48; 95% CI 1.35 to 1.61), medium severity contacts (IRR 1.38; 95% CI 1.28 to 1.49), and high severity contacts (IRR 1.40; 95% CI 1.30 to 1.51). Third, poverty was positively associated with 12 primary impression categories: abdominal (IRR 1.48; 95% CI 1.36 to 1.61), altered level of consciousness (IRR 1.37; 95% CI 1.25 to 1.50), cardiac (IRR 1.28; 95% CI 1.14 to 1.42), overdose/intoxication (IRR 1.59; 95% CI 1.40 to 1.81), pain (IRR 1.56; 95% CI 1.41 to 1.73), psych/behavioral (IRR 1.50; 95% CI 1.34 to 1.67), respiratory (IRR 1.42; 95% CI 1.29 to 1.56) seizure (IRR 1.52; 95% CI 1.38 to 1.68), stroke (IRR 1.14; 95% CI 1.01 to 1.28), syncope/near syncope (IRR 1.23; 95% CI 1.12 to 1.36), trauma (IRR 1.44; 95% CI 1.31 to 1.58), and general weakness (IRR 1.31; 95% CI 1.20 to 1.42). Our study suggests poverty is a positive, strong, and enduring predictor of ambulance contacts at the neighborhood level. The relationship between neighborhood poverty and ambulance utilization should be considered at multiple levels of EMS decision making.

Comparative Expression Analysis of Cytochrome P450 1A1, Cytochrome P450 1B1 and Nuclear Receptors in the Female Genital and Colorectal Tissues of Human and Pigtailed Macaque

PubMed Central

Hu, Minlu; Zhou, Tian; Pearlman, Andrew P; Paton, Dorothy L; Rohan, Lisa C

2017-01-01

Summary This manuscript summarizes our recent progress in examine the CYP1A1 and CYP1B1 as well as a number of nuclear receptors in the female genital and colorectal tissues of human and pigtailed macaque. Understanding the nuclear receptor mediated regulation of CYP1A1 and 1B1 expression in these tissues is necessary for identifying cancer risk factors and developing CYP1A1/1B1-targeted anti-cancer therapeutics. However, there is a lack of systematic and comparative analysis of the expression profile of CYP1A1, 1B1 and NRs in the female genital and colorectal tissues of human and clinically relevant animal models. The current study aims to fill this gap. We found CYP1A1, CYP1B1 and a number of nuclear receptors were expressed in the female genital and colorectal tissues of human and macaque. However, the mRNA level and protein localization of these CYP enzymes and NRs depended on the type of tissue examined. Cytochrome P450 (CYP) 1A1 and CYP1B1 activate hormonal and environmental procarcinogens, and are associated with carcinogenesis in female genital and colorectal tissues. Understanding the nuclear receptor (NR) mediated regulation of CYP expression in these tissues is necessary for identifying cancer risk factors and developing CYP1A1/1B1-targeted anti-cancer therapeutics. The study aims to analyze the expression profile of CYP1A1, 1B1 and NRs in the female genital and colorectal tissues of human and pigtailed macaques. We found that compared to the liver, human CYP1A1 mRNA level in the genital and colorectal tissues was significantly lower, while the CYP1B1 level was significantly higher. CYP1A1 protein was mainly localized in the plasma membrane of the uterine and endocervical epithelial cells. The CYP1B1 protein was concentrated in the nucleus of genital and colorectal tissues. Fourteen NRs in the genital tract and 12 NRs in colorectal tissue were expressed at levels similar to or higher than the liver. The expression and localization of CYP1A1, CYP1B1, and NRs in macaque tissues were usually comparable to those of human tissues. In addition, menopause did not significantly alter the ectocervical mRNA levels of CYP1A1, CYP1B1, or NRs. PMID:29276805

Comparative Expression Analysis of Cytochrome P450 1A1, Cytochrome P450 1B1 and Nuclear Receptors in the Female Genital and Colorectal Tissues of Human and Pigtailed Macaque.

PubMed

Hu, Minlu; Zhou, Tian; Pearlman, Andrew P; Paton, Dorothy L; Rohan, Lisa C

2016-01-01

This manuscript summarizes our recent progress in examine the CYP1A1 and CYP1B1 as well as a number of nuclear receptors in the female genital and colorectal tissues of human and pigtailed macaque. Understanding the nuclear receptor mediated regulation of CYP1A1 and 1B1 expression in these tissues is necessary for identifying cancer risk factors and developing CYP1A1/1B1-targeted anti-cancer therapeutics. However, there is a lack of systematic and comparative analysis of the expression profile of CYP1A1, 1B1 and NRs in the female genital and colorectal tissues of human and clinically relevant animal models. The current study aims to fill this gap. We found CYP1A1, CYP1B1 and a number of nuclear receptors were expressed in the female genital and colorectal tissues of human and macaque. However, the mRNA level and protein localization of these CYP enzymes and NRs depended on the type of tissue examined. Cytochrome P450 (CYP) 1A1 and CYP1B1 activate hormonal and environmental procarcinogens, and are associated with carcinogenesis in female genital and colorectal tissues. Understanding the nuclear receptor (NR) mediated regulation of CYP expression in these tissues is necessary for identifying cancer risk factors and developing CYP1A1/1B1-targeted anti-cancer therapeutics. The study aims to analyze the expression profile of CYP1A1, 1B1 and NRs in the female genital and colorectal tissues of human and pigtailed macaques. We found that compared to the liver, human CYP1A1 mRNA level in the genital and colorectal tissues was significantly lower, while the CYP1B1 level was significantly higher. CYP1A1 protein was mainly localized in the plasma membrane of the uterine and endocervical epithelial cells. The CYP1B1 protein was concentrated in the nucleus of genital and colorectal tissues. Fourteen NRs in the genital tract and 12 NRs in colorectal tissue were expressed at levels similar to or higher than the liver. The expression and localization of CYP1A1, CYP1B1, and NRs in macaque tissues were usually comparable to those of human tissues. In addition, menopause did not significantly alter the ectocervical mRNA levels of CYP1A1, CYP1B1, or NRs.

Scaffold Protein Ahk1, Which Associates with Hkr1, Sho1, Ste11, and Pbs2, Inhibits Cross Talk Signaling from the Hkr1 Osmosensor to the Kss1 Mitogen-Activated Protein Kinase

PubMed Central

Nishimura, Akiko; Yamamoto, Katsuyoshi; Oyama, Masaaki; Kozuka-Hata, Hiroko

2016-01-01

In the budding yeast Saccharomyces cerevisiae, osmostress activates the Hog1 mitogen-activated protein kinase (MAPK), which regulates diverse osmoadaptive responses. Hkr1 is a large, highly glycosylated, single-path transmembrane protein that is a putative osmosensor in one of the Hog1 upstream pathways termed the HKR1 subbranch. The extracellular region of Hkr1 contains both a positive and a negative regulatory domain. However, the function of the cytoplasmic domain of Hkr1 (Hkr1-cyto) is unknown. Here, using a mass spectrometric method, we identified a protein, termed Ahk1 (Associated with Hkr1), that binds to Hkr1-cyto. Deletion of the AHK1 gene (in the absence of other Hog1 upstream branches) only partially inhibited osmostress-induced Hog1 activation. In contrast, Hog1 could not be activated by constitutively active mutants of the Hog1 pathway signaling molecules Opy2 or Ste50 in ahk1Δ cells, whereas robust Hog1 activation occurred in AHK1+ cells. In addition to Hkr1-cyto binding, Ahk1 also bound to other signaling molecules in the HKR1 subbranch, including Sho1, Ste11, and Pbs2. Although osmotic stimulation of Hkr1 does not activate the Kss1 MAPK, deletion of AHK1 allowed Hkr1 to activate Kss1 by cross talk. Thus, Ahk1 is a scaffold protein in the HKR1 subbranch and prevents incorrect signal flow from Hkr1 to Kss1. PMID:26787842

31 CFR 1.1 - General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false General. 1.1 Section 1.1 Money and... § 1.1 General. (a) Purpose and scope. (1) This subpart contains the regulations of the Department of... legal counsel to the components listed in paragraphs (a)(1)(i)(W), (a)(1)(i)(X), (a)(1)(i)(Y), and (a)(1...

The Many Methods to Measure Testability: A Horror Story.

DTIC Science & Technology

1988-04-01

it seems overly simplistic to assign only one "magic number" as a viable design goal. Different design technologies such as digital, analog, machanical ...FAILURE RATE 1 1 BASIC TEST PROGRAM 1 1 ATLAS TEST PROGRAM 1 1 EDIF FILE 1 1 TEST STRATEGY FLOWCHART 1 1 RTOK FREQUENCY 1 1 DIAGNOSIS AVERAGE COST 1 1

Draft Final Risk Assessment Lime Settling Basins. Version 2.1

DTIC Science & Technology

1990-10-25

TABLE OF CON "S Section Page EXECUTIVE SUMMARY ...................................... v 1.0 INTRODUCTION ..................................... 1 - 1 1.1...BACKGROUND AND RATIONALE ........................ 1 - 1 1.2 SUMMARY OF APPROACH ............................. 1 -3 1.3 REPORT FORMAT... 1 -4 2.0 SITE DESCRIPTION AND HISTORY ......................... 2- 1 3.0 PREFERRED ALTERNATIVE INTERIM ACTION TECHNOLOGY ..... 3- 1 4.0

Tabulation of comet observations.

NASA Astrophysics Data System (ADS)

1995-07-01

Concerning comets: C/1958 D1 (Burnham), C/1959 Q1 (Alcock), C/1959 Q2 (Alcock), C/1959 Y1 (Burnham), C/1960 Y1 (Candy), C/1961 O1 (Wilson-Hubbard), C/1961 R1 (Humason), C/1961 T1 (Seki), C/1962 H1 (Honda), C/1963 A1 (Ikeya), C/1963 F1 (Alcock), C/1963 R1 (Pereyra), C/1964 N1 (Ikeya), C/1964 P1 (Everhart), C/1966 P1 (Kilston), C/1966 P2 (Barbon), C/1966 R1 (Ikeya-Everhart), C/1966 T1 (Rudnicki), C/1967 Y1 (Ikeya-Seki), C/1968 H1 (Tago-Honda-Yamamoto), C/1968 L1 (Whitaker-Thomas), C/1968 N1 (Honda), C/1968 Q1 (Bally-Clayton), C/1968 Q2 (Honda), C/1968 U1 (Wild), C/1968 Y1 (Thomas), C/1969 O1 (Kohoutek), C/1969 P1 (Fujikawa), C/1969 Y1 (Bennett), C/1970 B1 (Daido-Fujikawa), C/1970 N1 (Abe), C/1970 U1 (Suzuki-Sato-Seki), C/1971 E1 (Toba), C/1972 E1 (Bradfield), C/1972 L1 (Sandage), C/1972 U1 (Kojima), C/1973 A1 (Heck-Sause), C/1973 E1 (Kohoutek), C/1975 T1 (Mori-Sato-Fujikawa), C/1975 T2 (Suzuki-Saigusa-Mori), C/1975 V1 (West), C/1975 V2 (Bradfield), C/1975 X1 (Sato), C/1976 D1 (Bradfield), C/1977 V1 (Tsuchinshan), C/1984 N1 (Austin), C/1987 P1 (Bradfield), C/1988 A1 (Liller), C/1989 Q1 (Okazaki-Levy-Rudenko), C/1989 X1 (Austin), C/1990 E1 (Černis-Kiuchi-Nakamura), C/1990 K1 (Levy), C/1990 N1 (Tsuchiya-Kiuchi), C/1991 A2 (Arai), C/1991 F2 (Helin-Lawrence), C/1991 T2 (Shoemaker-Levy), C/1991 X2 (Mueller), C/1991 Y1 (Zanotta-Brewington), C/1992 F1 (Tanaka-Machholz), C/1992 U1 (Shoemaker), C/1992 W1 (Ohshita), C/1994 J2 (Takamizawa), C/1994 N1 (Nakamura-Nishimura-Machholz), C/1994 T1 (Machholz), 1P/Halley, 2P/Encke, 4P/Faye, 6P/d'Arrest, 8P/Tuttle, 9P/Tempel 1, 10P/Tempel 2, 15P/Finlay, 16P/Brooks 2, 19P/Borrelly, 23P/Brorsen-Metcalf, 24P/Schaumasse, 29P/Schwassmann-Wachmann 1, 31P/Schwassmann-Wachmann 2, 40P/Väisälä 1, 41P/Tuttle-Giacobini-Kresák, 45P/Honda-Mrkos-Pajdušáková, 51P/Harrington, 59P/Kearns-Kwee, 64P/Swift-Gehrels, 65P/Gunn, 71P/Clark, 73P/Schwassmann-Wachmann 3, 75P/Kohoutek, 76P/West-Kohoutek-Ikemura, 77P/Longmore, 78P/Gehrels 2, 85P/Boethin, 95P/Chiron, 97P/Metcalf-Brewington, 103P/Hartley 2, 104P/Kowal 2, 108P/Ciffréo, 109P/Swift-Tuttle, 110P/Hartley 3, 116P/Wild 4, P/1991 L3 (Levy), P/1991 V1 (Shoemaker-Levy 6), P/1992 Q1 (Brewington), P/1993 W1 (Mueller 5), P/1994 P1 (Machholz 2).

Metformin suppresses CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating aryl hydrocarbon receptor expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Do, Minh Truong; Kim, Hyung Gyun; Tran, Thi Thu Phuong

2014-10-01

Induction of cytochrome P450 (CYP) 1A1 and CYP1B1 by environmental xenobiotic chemicals or endogenous ligands through the activation of the aryl hydrocarbon receptor (AhR) has been implicated in a variety of cellular processes related to cancer, such as transformation and tumorigenesis. Here, we investigated the effects of the anti-diabetes drug metformin on expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and inducible conditions. Our results indicated that metformin down-regulated the expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced conditions. Down-regulation of AhR expression was required for metformin-mediated decreases in CYP1A1 andmore » CYP1B1 expression, and the metformin-mediated CYP1A1 and CYP1B1 reduction is irrelevant to estrogen receptor α (ERα) signaling. Furthermore, we found that metformin markedly down-regulated Sp1 protein levels in breast cancer cells. The use of genetic and pharmacological tools revealed that metformin-mediated down-regulation of AhR expression was mediated through the reduction of Sp1 protein. Metformin inhibited endogenous AhR ligand-induced CYP1A1 and CYP1B1 expression by suppressing tryptophan-2,3-dioxygenase (TDO) expression in MCF-7 cells. Finally, metformin inhibits TDO expression through a down-regulation of Sp1 and glucocorticoid receptor (GR) protein levels. Our findings demonstrate that metformin reduces CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating AhR signaling. Metformin would be able to act as a potential chemopreventive agent against CYP1A1 and CYP1B1-mediated carcinogenesis and development of cancer. - Graphical abstract: Schematic of the CYP1A1 and CYP1B1 gene regulation by metformin. - Highlights: • Metformin inhibits CYP1A1 and CYP1B1 expression. • Metformin down-regulates the AhR signaling. • Metformin reduces Sp1 protein expression. • Metformin suppresses TDO expression.« less

Effectiveness of anti-PD-1/PD-L1 antibodies in urothelial carcinoma patients with different PD-L1 expression levels: a meta-analysis.

PubMed

Liu, Junqi; Zhang, Chuanfeng; Hu, Jiegang; Tian, Qing; Wang, Xin; Gu, Hao; Zhang, Song; Zhao, Di; Fan, Ruitai

2018-02-23

Urothelial carcinoma ranks the ninth among malignant cancers. We conducted this study to identify which patients could benefit more from the treatment of programmed death-1 (PD-1)/programmed death-ligand1 (PD-L1) inhibitors. We performed literature searches, combined data from qualified literature and performed comparative analyses on the effectiveness of anti-PD-1/PD-L1 antibodies in patients with different PD-L1 expression levels. We divided patients into three groups according to the percentages of PD-L1-positive cells, namely the low- PD-L1 (PD-L1 < 1%), the medium-PD-L1 (PD-L1 ≥ 1 and < 5%) and the high-PD-L1 (PD-L1 ≥ 5%) groups. We found that the high-PD-L1 group responded significantly better than other groups (P = 0.0003, ORs = 0.45, 95%CI: 0.29-071; P = 0.0009, ORs = 0.43, 95%CI: 0.25-0.73, for low-PD-L1 and medium-PD-L1 groups, respectively), while the latter two groups responded similarly (P = 0.90, ORs = 1.06, 95%CI: 0.62-1.83) to both PD-1 and PD-L1 inhibitors. Furthermore, we found that the medium-PD-L1 and high-PD-L1 groups responded similarly to PD-1/ PD-L1 inhibitors (P = 0.65, ORs = 1.11, 95%CI: 0.69-1.77), while the low-PD-L1 group responded better to PD-1 inhibitors than PD-L1 inhibitors (P = 0.046, ORs = 1.92, 95%CI: 0.98-3.89). Our results suggest that PD-L1 positive patients should be defined as those with ≥ 5% or greaterPD-L1-positive cells. PD-1 antibodies performed better only in the low-group patients, likely because they could block the interactions of PD-1 with both PD-L1 and PD-L2.

Vapor-liquid equilibria for 1,1,1,2-tetrafluoroethane + 1-chloro-1,2,2,2-tetrafluoroethane and 1-chloro-1,2,2,2-tetrafluoroethane + 1-chloro-1,1-difluoroethane systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, J.; Lee, J.; Kim, H.

1996-07-01

Isothermal vapor-liquid equilibria were determined for two binary mixtures of refrigerants with a circulation type apparatus. The 1,1,1,2-tetrafluoroethane (HFC-134a) + 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124) system was studied at 296.45, 302.25, and 307.25 K. The 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124) + 1-chloro-1,1-difluoroethane (HCFC-142b) system was studied at 298.15 and 312.15 K. At each temperature, the pressure and vapor and liquid compositions were measured. Results were correlated with the Peng-Robinson equation of state.

Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials.

PubMed

Milanović, Zoran; Sporiš, Goran; Weston, Matthew

2015-10-01

Enhancing cardiovascular fitness can lead to substantial health benefits. High-intensity interval training (HIT) is an efficient way to develop cardiovascular fitness, yet comparisons between this type of training and traditional endurance training are equivocal. Our objective was to meta-analyse the effects of endurance training and HIT on the maximal oxygen consumption (VO2max) of healthy, young to middle-aged adults. Six electronic databases were searched (MEDLINE, PubMed, SPORTDiscus, Web of Science, CINAHL and Google Scholar) for original research articles. A search was conducted and search terms included 'high intensity', 'HIT', 'sprint interval training', 'endurance training', 'peak oxygen uptake', and 'VO2max'. Inclusion criteria were controlled trials, healthy adults aged 18-45 years, training duration ≥2 weeks, VO2max assessed pre- and post-training. Twenty-eight studies met the inclusion criteria and were included in the meta-analysis. This resulted in 723 participants with a mean ± standard deviation (SD) age and initial fitness of 25.1 ± 5 years and 40.8 ± 7.9 mL·kg(-1)·min(-1), respectively. We made probabilistic magnitude-based inferences for meta-analysed effects based on standardised thresholds for small, moderate and large changes (0.2, 0.6 and 1.2, respectively) derived from between-subject SDs for baseline VO2max. The meta-analysed effect of endurance training on VO2max was a possibly large beneficial effect (4.9 mL·kg(-1)·min(-1); 95 % confidence limits ±1.4 mL·kg(-1)·min(-1)), when compared with no-exercise controls. A possibly moderate additional increase was observed for typically younger subjects (2.4 mL·kg(-1)·min(-1); ±2.1 mL·kg(-1)·min(-1)) and interventions of longer duration (2.2 mL·kg(-1)·min(-1); ±3.0 mL·kg(-1)·min(-1)), and a small additional improvement for subjects with lower baseline fitness (1.4 mL·kg(-1)·min(-1); ±2.0 mL·kg(-1)·min(-1)). When compared with no-exercise controls, there was likely a large beneficial effect of HIT (5.5 mL·kg(-1)·min(-1); ±1.2 mL·kg(-1)·min(-1)), with a likely moderate greater additional increase for subjects with lower baseline fitness (3.2 mL·kg(-1)·min(-1); ±1.9 mL·kg(-1)·min(-1)) and interventions of longer duration (3.0 mL·kg(-1)·min(-1); ±1.9 mL·kg(-1)·min(-1)), and a small lesser effect for typically longer HIT repetitions (-1.8 mL·kg(-1)·min(-1); ±2.7 mL·kg(-1)·min(-1)). The modifying effects of age (0.8 mL·kg(-1)·min(-1); ±2.1 mL·kg(-1)·min(-1)) and work/rest ratio (0.5 mL·kg(-1)·min(-1); ±1.6 mL·kg(-1)·min(-1)) were unclear. When compared with endurance training, there was a possibly small beneficial effect for HIT (1.2 mL·kg(-1)·min(-1); ±0.9 mL·kg(-1)·min(-1)) with small additional improvements for typically longer HIT repetitions (2.2 mL·kg(-1)·min(-1); ±2.1 mL·kg(-1)·min(-1)), older subjects (1.8 mL·kg(-1)·min(-1); ±1.7 mL·kg(-1)·min(-1)), interventions of longer duration (1.7 mL·kg(-1)·min(-1); ±1.7 mL·kg(-1)·min(-1)), greater work/rest ratio (1.6 mL·kg(-1)·min(-1); ±1.5 mL·kg(-1)·min(-1)) and lower baseline fitness (0.8 mL·kg(-1)·min(-1); ±1.3 mL·kg(-1)·min(-1)). Endurance training and HIT both elicit large improvements in the VO2max of healthy, young to middle-aged adults, with the gains in VO2max being greater following HIT when compared with endurance training.

Marine Analysis Using a Rapid Scanning Multichannel Fluorometer.

DTIC Science & Technology

1985-04-30

investigated is provided in Table I. Listings Table I. Laboratory algae collection. Class Species Source Media Chlorophyceae Chlorella vulgaris 1 ASP 6...of spectral matching. Hit # Specie A B C Chlorella vulgaris 1 1 1 Dunaliela salina 1 1 1 Tetraselmis sp. 1 1 1 Spirulina major 1 1 1 Skeletonema

Epidemiology of Fracture Nonunion in 18 Human Bones.

PubMed

Zura, Robert; Xiong, Ze; Einhorn, Thomas; Watson, J Tracy; Ostrum, Robert F; Prayson, Michael J; Della Rocca, Gregory J; Mehta, Samir; McKinley, Todd; Wang, Zhe; Steen, R Grant

2016-11-16

Failure of bone fracture healing occurs in 5% to 10% of all patients. Nonunion risk is associated with the severity of injury and with the surgical treatment technique, yet progression to nonunion is not fully explained by these risk factors. To test a hypothesis that fracture characteristics and patient-related risk factors assessable by the clinician at patient presentation can indicate the probability of fracture nonunion. An inception cohort study in a large payer database of patients with fracture in the United States was conducted using patient-level health claims for medical and drug expenses compiled for approximately 90.1 million patients in calendar year 2011. The final database collated demographic descriptors, treatment procedures as per Current Procedural Terminology codes; comorbidities as per International Classification of Diseases, Ninth Revision codes; and drug prescriptions as per National Drug Code Directory codes. Logistic regression was used to calculate odds ratios (ORs) for variables associated with nonunion. Data analysis was performed from January 1, 2011, to December 31, 2012. Continuous enrollment in the database was required for 12 months after fracture to allow sufficient time to capture a nonunion diagnosis. The final analysis of 309 330 fractures in 18 bones included 178 952 women (57.9%); mean (SD) age was 44.48 (13.68) years. The nonunion rate was 4.9%. Elevated nonunion risk was associated with severe fracture (eg, open fracture, multiple fractures), high body mass index, smoking, and alcoholism. Women experienced more fractures, but men were more prone to nonunion. The nonunion rate also varied with fracture location: scaphoid, tibia plus fibula, and femur were most likely to be nonunion. The ORs for nonunion fractures were significantly increased for risk factors, including number of fractures (OR, 2.65; 95% CI, 2.34-2.99), use of nonsteroidal anti-inflammatory drugs plus opioids (OR, 1.84; 95% CI, 1.73-1.95), operative treatment (OR, 1.78; 95% CI, 1.69-1.86), open fracture (OR, 1.66; 95% CI, 1.55-1.77), anticoagulant use (OR, 1.58; 95% CI, 1.51-1.66), osteoarthritis with rheumatoid arthritis (OR, 1.58; 95% CI, 1.38-1.82), anticonvulsant use with benzodiazepines (OR, 1.49; 95% CI, 1.36-1.62), opioid use (OR, 1.43; 95% CI, 1.34-1.52), diabetes (OR, 1.40; 95% CI, 1.21-1.61), high-energy injury (OR, 1.38; 95% CI, 1.27-1.49), anticonvulsant use (OR, 1.37; 95% CI, 1.31-1.43), osteoporosis (OR, 1.24; 95% CI, 1.14-1.34), male gender (OR, 1.21; 95% CI, 1.16-1.25), insulin use (OR, 1.21; 95% CI, 1.10-1.31), smoking (OR, 1.20; 95% CI, 1.14-1.26), benzodiazepine use (OR, 1.20; 95% CI, 1.10-1.31), obesity (OR, 1.19; 95% CI, 1.12-1.25), antibiotic use (OR, 1.17; 95% CI, 1.13-1.21), osteoporosis medication use (OR, 1.17; 95% CI, 1.08-1.26), vitamin D deficiency (OR, 1.14; 95% CI, 1.05-1.22), diuretic use (OR, 1.13; 95% CI, 1.07-1.18), and renal insufficiency (OR, 1.11; 95% CI, 1.04-1.17) (multivariate P < .001 for all). The probability of fracture nonunion can be based on patient-specific risk factors at presentation. Risk of nonunion is a function of fracture severity, fracture location, disease comorbidity, and medication use.

dni_slope_filter_1

Science.gov Websites

"GRIDCODE" true true false 19 Double 10 18 ,First,#,int_60,GRIDCODE,-1,-1,int_59,GRIDCODE,-1 ; true true false 19 Double 10 18 ,First,#,int_60,AVE_DNI,-1,-1,int_59,AVE_DNI,-1,-1,int_58,AVE_DNI,-1,-1 ,int_02,AVE_DNI,-1,-1,int_01,AVE_DNI,-1,-1,int_00,AVE_DNI,-1,-1;AVE_GHI "AVE_GHI" true true

78 FR 56242 - Notice of Realty Action: Competitive Sale of 28 Parcels of Public Land in Clark County, NV

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-12

... acres: T. 20 S., R. 60 E., Sec. 6, NW\\1/4\\SW\\1/4\\SE\\1/4\\, W\\1/2\\NE\\1/4\\SW\\1/4\\SE\\1/4\\, NE\\1/4\\NE\\1/4\\SW\\1/4\\SE\\1/4\\. N-78190, 2.50 acres: T. 22 S., R. 60 E., Sec. 14, NW\\1/4\\SW\\1/4\\NW\\1/4\\SW\\1/4\\. N-91783, 5.00 acres: T. 22 S., R. 60 E., Sec. 14, S\\1/2\\SW\\1/4\\SW\\1/4\\SW\\1/4\\. N-91794, 10.00 acres: T. 22 S...

Implementation: Ultrasonic Sealing of Preformed Pouches in Production

DTIC Science & Technology

2005-11-10

1 Open Seal 1 06/15/04 Chicken Tetrazzini 4162A 3,960 1 Open Seal 1 06/17/04 Raspberry Applesauce 4163A 4,525 1 1 06/17/04 Mexican Rice 4166A...6,784 1 1 06/19/04 Chicken Noodles 4167A 8,718 1 Open Seal & Foldover Wrinkle 1 06/21/04 Raspberry Applesauce 4168A 1,490 1 1 07/24/04 Mexican...4212A 13,109 1 1 08/06/04 Applesauce (Carbo Enhanced) 4213A 10,296 1 1 08/20/04 Mexican Rice 4222A 2,127 1 1 08/23/04 Cheese Tortellini 4224A

Risk of several cancers is higher in urban areas after adjusting for socioeconomic status. Results from a two-country population-based study of 18 common cancers.

PubMed

Sharp, Linda; Donnelly, David; Hegarty, Avril; Carsin, Anne-Elie; Deady, Sandra; McCluskey, Neil; Gavin, Anna; Comber, Harry

2014-06-01

Some studies suggest that there are urban-rural variations in cancer incidence but whether these simply reflect urban-rural socioeconomic variation is unclear. We investigated whether there were urban-rural variations in the incidence of 18 cancers, after adjusting for socioeconomic status. Cancers diagnosed between 1995 and 2007 were extracted from the population-based National Cancer Registry Ireland and Northern Ireland Cancer Registry and categorised by urban-rural status, based on population density of area of residence at diagnosis (rural <1 person per hectare, intermediate 1-15 people per hectare, urban >15 people per hectare). Relative risks (RR) were calculated by negative binomial regression, adjusting for age, country and three area-based markers of socioeconomic status. Risks were significantly higher in both sexes in urban than rural residents with head and neck (males RR urban vs. rural = 1.53, 95 % CI 1.42-1.64; females RR = 1.29, 95 % CI 1.15-1.45), esophageal (males 1.21, 1.11-1.31; females 1.21, 1.08-1.35), stomach (males 1.36, 1.27-1.46; females 1.19, 1.08-1.30), colorectal (males 1.14, 1.09-1.18; females 1.04, 1.00-1.09), lung (males 1.54, 1.47-1.61; females 1.74, 1.65-1.84), non-melanoma skin (males 1.13, 1.10-1.17; females 1.23, 1.19-1.27) and bladder (males 1.30, 1.21-1.39; females 1.31, 1.17-1.46) cancers. Risks of breast, cervical, kidney and brain cancer were significantly higher in females in urban areas. Prostate cancer risk was higher in rural areas (0.94, 0.90-0.97). Other cancers showed no significant urban-rural differences. After adjusting for socioeconomic variation, urban-rural differences were evident for 12 of 18 cancers. Variations in healthcare utilization and known risk factors likely explain some of the observed associations. Explanations for others are unclear and, in the interests of equity, warrant further investigation.

Rare Earth Ion-Host Lattice Interactions. 9. Lanthanides in YAsO4

DTIC Science & Technology

1976-08-01

CA 1:.1E 043 S.:11 04 5:602( 0ZZ1 ) 2.$02 1 1 01. 1 1 0.43 I 1 1 .1 4S# 2 1.10 1 J. I1-0 ’*546 1Z 2.lE 19 $e6l )2I 0, 2:.411 O) .l [0 .ll0 k4 4 113...04 " .471 0 .1 26E 04 2.391F 00 2.2431 03 3.001( 04 6.043 s 03 22 6113/1 .M 04 1.36% 3 ) .3 1" 01 1.120 043 . 04 :52f 0200 1.330F 0) 2.4084 0 7 23:0t...0 4.1141 01 1 1 6 1:11"E " .6111-Ol 64 111 4.012* 0 1 S.184t 0 4 4 4 61 04 6-ME a) 1.230C 04 NOM 04 9.521t Of 2.ST4 a of I .ME 01 Most 04 3.4SSE Ok

TPE331/T76 Turboprop Propulsion Engine Durability.

DTIC Science & Technology

1982-08-01

61018 01 0a I as1 1 1 se I al I 0S I 0 1*71 178 426* CUTS 41013 1Ii) 1 7*3 4173 1177* 11141 17 0 a * so *9 70 0 0 0 0 0 10 30 10 0 .1 A 45 90) 10 I 0...a 0 19 s0 *0 * 41013 (117) 41143 1 33 6 as I II I 0* 4*793 6 7O1 1 4 Go I it I a3 I 03 0 3 1 61 1 0* I ofI 9)1 1 si 1 761 1 303 5 40 40 19 0 0 1 0 0...flail 3* 9 19 5 0 0 1 45 1*9 0 a 0 64 45 0 49 0 0 A 1o 40 i0 I Li1 303 6 111 1 0* 1 30 1 41145 13171 41013 I 03 I 0* 61013 41148 4 0* I114 1 of I * co

Meat and meat-related compounds and risk of prostate cancer in a large prospective cohort study in the United States.

PubMed

Sinha, Rashmi; Park, Yikyung; Graubard, Barry I; Leitzmann, Michael F; Hollenbeck, Albert; Schatzkin, Arthur; Cross, Amanda J

2009-11-01

The authors examined associations between meat consumption (type, cooking method, and related mutagens), heme iron, nitrite/nitrate, and prostate cancer in a cohort of 175,343 US men aged 50-71 years. During 9 years of follow-up (1995-2003), they ascertained 10,313 prostate cancer cases (1,102 advanced) and 419 fatal cases. Hazard ratios comparing the fifth intake quintile with the first revealed elevated risks associated with red and processed meat for total (red meat: hazard ratio (HR) = 1.12, 95% confidence interval (CI): 1.04, 1.21; processed meat: HR = 1.07, 95% CI: 1.00, 1.14) and advanced (red meat: HR = 1.31, 95% CI: 1.05, 1.65; processed meat: HR = 1.32, 95% CI: 1.08, 1.61) prostate cancer. Heme iron, barbecued/grilled meat, and benzo[a]pyrene were all positively associated with total (HR = 1.09 (95% CI: 1.02, 1.17), HR = 1.11 (95% CI: 1.03, 1.19), and HR = 1.09 (95% CI: 1.00, 1.18), respectively) and advanced (HR = 1.28 (95% CI: 1.03, 1.58), HR = 1.36 (95% CI: 1.10, 1.69), and HR = 1.28 (95% CI: 1.00, 1.65), respectively) disease. Nitrite (HR = 1.24, 95% CI: 1.02, 1.51) and nitrate (HR = 1.31, 95% CI: 1.07, 1.61) intakes were associated with advanced prostate cancer. There were no clear associations for fatal prostate cancer. Red and processed meat may be positively associated with prostate cancer via mechanisms involving heme iron, nitrite/nitrate, grilling/barbecuing, and benzo[a]pyrene.

SGT1 is required in PcINF1/SRC2-1 induced pepper defense response by interacting with SRC2-1

PubMed Central

Liu, Zhi-qin; Liu, Yan-yan; Shi, Lan-ping; Yang, Sheng; Shen, Lei; Yu, Huan-xin; Wang, Rong-zhang; Wen, Jia-yu; Tang, Qian; Hussain, Ansar; Khan, Muhammad Ifnan; Hu, Jiong; Liu, Cai-ling; Zhang, Yang-wen; Cheng, Wei; He, Shui-lin

2016-01-01

PcINF1 was previously found to induce pepper defense response by interacting with SRC2-1, but the underlying mechanism remains uninvestigated. Herein, we describe the involvement of SGT1 in the PcINF1/SRC2-1-induced immunity. SGT1 was observed to be up-regulated by Phytophthora capsici inoculation and synergistically transient overexpression of PcINF1/SRC2-1 in pepper plants. SGT1-silencing compromised HR cell death, blocked H2O2 accumulation, and downregulated HR-associated and hormones-dependent marker genes’ expression triggered by PcINF1/SRC2-1 co-overexpression. The interaction between SRC2-1 and SGT1 was found by the yeast two hybrid system and was further confirmed by bimolecular fluorescence complementation and co-immunoprecipitation analyses. The SGT1/SRC2-1 interaction was enhanced by transient overexpression of PcINF1 and Phytophthora capsici inoculation, and SGT1-silencing attenuated PcINF1/SRC2-1 interaction. Additionally, by modulating subcellular localizations of SRC2-1, SGT1, and the interacting complex of SGT1/SRC2-1, it was revealed that exclusive nuclear targeting of the SGT1/SRC2-1 complex blocks immunity triggered by formation of SGT1/SRC2-1, and a translocation of the SGT1/SRC2-1 complex from the plasma membrane and cytoplasm to the nuclei upon the inoculation of P. capsici. Our data demonstrate that the SGT1/SRC2-1 interaction, and its nucleocytoplasmic partitioning, is involved in pepper’s immunity against P. capsici, thus providing a molecular link between Ca2+ signaling associated SRC2-1 and SGT1-mediated defense signaling. PMID:26898479

Movie Physics: pirates, spies and other worlds

NASA Astrophysics Data System (ADS)

Gonzalez Del Rio, Beatriz; Gonzalez-Fernandez, V.; Martin, J. L.; Sanchez-Tejerina, L.; Perez, G.; Ares, L.; Vasallo, E.; Martin, P.; Villa, V.; Garcia, S.; Vara, M.; Martin, S.; Alvarez, P.; Gonzalez, C.; Lopez, P.; Burgos, M. A.; Gonzalez, V. M.; Carbajo, J.; Velasco-Merino, C.; Hevia, F.; Martinez, F.; Martinez, J. F.; Gonzalez-Herrero, D.; Gloriani, A. H.; Mateos, D.

Taking advantage of many popular films, the basics of many physical principles can be shown in a really attractive and stunning way. Five shows/workshops form this project attending the necessities of the target public: kids become pirates, high-school students are pushed to the limit and visit other fantasy worlds, and the general public discover the powers of physics and some terrifying secrets. By November 2015 we have obtained more than 2900 viewers. The activities have been presented in different national and international conferences, on an international science fair and have been published by several Spanish media. During 2015 the Physics League Association has received three international awards due to some activities from this project. Additional Authors: B. G. del Rio [1 2], V. González-Fernández [1 2], J. L. Martín [1], L. Sánchez-Tejerina [1 2], G. Pérez [1], L. Ares [1], E. Vasallo [1], P. Martín [1], V. Villa [1], S. García [1], M. Vara [1], S. Martín [1], P. Álvarez [1], C. González [1], P. López [1], M.A. Burgos [1 2], V. M. González [1], J. Carbajo [1], C. Velasco-Merino [1 2], F. Hevia [1 2], D. Gutiez [1], F. Martínez [1], J. F. Martínez [1], L. E. Vazquez [1], M. Bueno [1], M. Escribano [1], P. Guillem [1], R. García [1], D. González [1], D. González-Herrero [1 2], A. H. Gloriani [1 2], J. Cítores [1], J. Hernández [1], A. Álvarez [1], M. Álvarez [1], D. Mateos [1 2] [1] Physics League Association, SPAIN [2] Universidad de Valladolid, SPAIN Aps Mini Grants 2015, EPS Young Minds and OSA.

Human Respiratory Responses during High Performance Flight

DTIC Science & Technology

1987-11-01

of walking in chemical defence clothing. RAF Institute of Aviation Medicine Aircrew Equipment Group Report No 347 , 1975. 95 Gibson T M, Anton D...1.05 1.01 1.15 1.07 0.0391 0.6223 0.C243 2 Taxy (pre-flight) . 1.00 1.01 1.05 1.08 1.02 0.0296 0.4187 0.0124 1 Jako -oft . 1.09 - 1.13 1.15 1.55 1.14

40 CFR 721.10171 - 1H-benz(e)indolium, 1,1,2,3-tetramethyl-, 4-methylbenzenesulfonic acid (1:1).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1H-benz(e)indolium, 1,1,2,3... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10171 1H-benz(e)indolium, 1,1,2,3... reporting. (1) The chemical substance identified as 1H-benz(e)indolium, 1,1,2,3-tetramethyl-, 4...

Early Diagnosis and Intervention Strategies for Post-Traumatic Heterotopic Ossification in Severely Injured Extremities

DTIC Science & Technology

2015-10-01

enhancer binding protein (C/EBP), alpha COL10A1 collagen, type X, alpha 1 COL11A1 collagen, type XI, alpha 1 COL1A1 collagen, type I, alpha 1 COL2A1...172.4535 Spp1  1105.6776 Col1a1   137.7958 Tac1  130.0625 ll1b  67.3332 Cxcl5  86.3414 ll10  49.9631 Col1a1   84.2834 Has1  45.5771 ll1b  74.488 Tac1

75 FR 41237 - Public Land Order No. 7746; Withdrawal of Public Lands, South Fork of the American River; California

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-15

... the American River: Mount Diablo Meridian T. 11 N., R. 9 E., Sec. 10, NW\\1/4\\NW\\1/4\\ and S\\1/2\\; Sec...\\,SW\\1/4\\, and SE\\1/4\\; Sec. 32, N\\1/2\\NE\\1/4\\, SW\\1/4\\NE\\1/4\\, W\\1/2\\, and S\\1/2\\SE\\1/ 4\\. T. 11 N., R. 10 E., Sec. 18, lots 5, 6, and 7, and NW\\1/4\\NE\\1/4\\NW\\1/4\\; Sec. 22, NW\\1/4\\SE\\1/4\\SW\\1/4\\, and that...

Characterization of H1N1 swine influenza viruses circulating in Canadian pigs in 2009.

PubMed

Nfon, Charles K; Berhane, Yohannes; Hisanaga, Tamiko; Zhang, Shunzhen; Handel, Katherine; Kehler, Helen; Labrecque, Olivia; Lewis, Nicola S; Vincent, Amy L; Copps, John; Alexandersen, Soren; Pasick, John

2011-09-01

The 2009 pandemic H1N1 (pH1N1), of apparent swine origin, may have evolved in pigs unnoticed because of insufficient surveillance. Consequently, the need for surveillance of influenza viruses circulating in pigs has received added attention. In this study we characterized H1N1 viruses isolated from Canadian pigs in 2009. Isolates from May 2009 were comprised of hemagglutinin and neuraminidase (NA) genes of classical SIV origin in combination with the North American triple-reassortant internal gene (TRIG) cassette, here termed contemporary SIV (conSIV) H1N1. These conSIV H1N1 viruses were contiguous with the North American αH1 cluster, which was distinct from the pH1N1 isolates that were antigenically more related to the γH1 cluster. After the initial isolation of pH1N1 from an Alberta pig farm in early May 2009, pH1N1 was found several times in Canadian pigs. These pH1N1 isolates were genetically and antigenically homogeneous. In addition, H1N1 viruses bearing seasonal human H1 and N1 genes together with the TRIG cassette and an NA encoding an oseltamivir-resistance marker were isolated from pigs. The NS gene of one of these seasonal human-like SIV (shSIV) H1N1 isolates was homologous to pH1N1 NS, implicating reassortment between the two strains. Antigenic cross-reactivity was observed between pH1N1 and conSIV but not with shSIV H1N1. In summary, although there was cocirculation of pH1N1 with conSIV and shSIV H1N1 in Canadian pigs after May 2009, there was no evidence supporting the presence of pH1N1 in pigs prior to May 2009. The possibility for further reassortants being generated exists and should be closely monitored.

Reliability/Maintainability/Testability Design for Dormancy

DTIC Science & Technology

1988-05-01

compositions was developed thousands of years ago. It has proven to be one of the most durable and strongest substances known. It has been stated that glass can...potting or casting) ,1, Certain foamed resins and low density , hollow beady compounds can be used to reduce .eight r \\dverse l)ielectric Properties I...4.1.1.1 General Characteristics of Fixed Resistors 4.1-13 4.1.1.1.1 Fixed Composition Resistors 4.1-13 4.1.1.1.2 Fixed Film Resistors 4.1-20 4.1.1.1.3

The Index of Refraction of Seawater

DTIC Science & Technology

1976-01-01

1� 1-35207 1�" 1� 1" 31138 1055 k1,/1 1-35953 1.35891 1,35835 135763 1 5 3 1.35631 135560 13c952 135892 1-35832 1t3576h 1i3p5696 1-35633...SEAWATER Roswell W. Austin and George Halika! 5 TECHNICAL REPORT Approved for public release; distribution unlimited SIO Ref. No. 76-1 I ;January 1976 P...ohrstudies to demonstrate the degree of agreement. This we have done in Section 5 . Considering the variety of sources and the span of years involved, we

User’s Guide for Crew Chief: A Computer Graphics Simulation of an Aircraft Maintenance Technician (Version 1 - CD 20)

DTIC Science & Technology

1988-05-25

theoretical approaches used in developing the proqrams. The introduction of the report (Section 1) gives general background of the concepts and... GENERATION 1-5 1.3 WORKPLACE DESIGN 1-6 1.4 THE CREW CHIEF MAINTENANCE ANALYSIS PROGRAMS 1-7 1.5 GETTING STARTED 1-11 2 CREW CHIEF GENERATION FUNCTIONS...OPTIONS 8-1 9 QUICK REFERENCE 9-1 9.1 CREW CHIEF GENERATION FUNCTIONS (@CCGEN) 9-1 9.1.1 CREW CHIEF Initialization Function (CCINIT) 9-1 9.1.2 CREW CHIEF

Alternative Training Agents Phase 4. Large-Scale Tests

DTIC Science & Technology

1992-02-01

20 BLEND BY MOLES OF 2,2-DICHLORO-1,1,1-TRIFLUOROETHANE AND 1-CHLORO-1,1- DIFLUOROETHANE , BOTH TECHNICAL GRADES)** 1.0 SCOPE 1.1 This specification...pure 1-chloro- 1,1- difluoroethane , suitable as a fire extinguishing fluid for firefighter training and shall conform to the requirements of Table B-1...percent by moles 1-Chloro-1,l- difluoroethane 20.0 ± 1 4.4.1 percent by moles Boiling Point, degrees Celsius -10 to +28 4.4.2 at 760 mm Hg (14 to 82 ’F

Connective Tissue Growth Factor (CTGF) as a Regulator of Lactogenic Differentiation

DTIC Science & Technology

2009-06-09

1 1.62 Myeloid leukemia factor 1, Mlf1 1.57 ADAMTS-l4 1.55 E2F transcription factor, E2F2 1.44 Tensin 4 -1.5 BCL2/adenovirus E1B interacting... Mlf1 1.57 ADAMTS-l4 1.55 Ras homolog gene family, member B, RhoB 1.48 Cell Differentiation-associated Wingless-type MMTV integration site family...B, relB 1.92 Myeloid leukemia factor 1, Mlf1 1.57 Growth Factor, Catalytic Activity-associated Dual specificity protein phosphatase 8, Dusp8

Micro-Flow Studies in the 1 to 50 Micron Domain

DTIC Science & Technology

2001-08-01

heating the samples in a torch was sufficient to restore them to their original condition. 18 2.1.1.2 Fabrication of Small (pm) Microchannels UCI was...SUMMARY 1 1.0 INTRODUCTION 1 1.1 Program Overview 1 1.2 Survey of the Literature 3 1.2.1 Flow in Rectangular Microchannel Ducts 3 1.2.2 Heat Transfer...in Microchannel Ducts 6 1.2.3 Other Micro-Flow Studies 8 2.0 STRAIGHT MICROCHANNEL FLOW STUDIES 9 2.1 Experimental Approach 9 2.1.1 Sample Fabrication

Purification, characterization, antioxidant and anticancer activities of novel polysaccharides extracted from Bachu mushroom.

PubMed

Zeng, Di; Zhu, Siming

2018-02-01

Two novel polysaccharide fractions (HLP1-1 and HLP2-1) were purified from crude polysaccharides of Helvella leucopus by using DEAE-52 column (2.6cm×20cm) and Sephadex G-150 column (1.6×60cm). The characterization, antioxidant and anticancer activities of HLP1-1 and HLP2-1 were investigated. The GPC results showed that HLP1-1 and HLP2-1 had similar molecular weight (21,382Da and 23,063Da, respectively). Tertiary structure analyses indicated that HLP2-1 had triple-helical conformation, but HLP1-1 not. The monosaccharide compositions of HLP1-1 included rhamnose, glucosamine and mannose at a molar ratio of 11.8:1:78.6, and HLP2-1 included of rhamnose, glucosamine, glucose and mannose at a molar ratio of 4.2:1:18.1:27.3. Both HLP1-1 and HLP2-1 showed a certain antioxidant activity, and HLP2-1 showed stronger antioxidant activities than HLP1-1. Both HLP1-1 and HLP2-1 exhibited a relatively inhibition on HepG2. Copyright © 2017 Elsevier B.V. All rights reserved.

Is HLA the cause of the high incidence of type 1 diabetes in the Canary Islands? Results from the Type 1 Diabetes Genetics Consortium (T1DGC).

PubMed

Santana Del Pino, Angelo; Medina-Rodríguez, Nathan; Hernández-García, Marta; Nóvoa-Mogollón, Francisco J; Wägner, Ana M

2017-03-01

Incidence of childhood-onset type 1 diabetes mellitus in the Canary Islands is the highest reported so far in Spain, and among the highest worldwide. The HLA region accounts for approximately half the genetic risk of type 1 diabetes. Our aim was to assess distribution of high-risk and protective HLA haplotypes in the Canarian families included in the T1DGC, as compared to the rest of Spain. The T1DGC study, an international project to study the genetics and pathogenesis of type 1 diabetes, enrolled more than 3000 families with type 1 diabetes worldwide. Spain provided 149 of these families, of whom 42 were from Tenerife and Gran Canaria. HLA was genotyped centrally using a PCR-based, sequence-specific oligonucleotide probe system. Haplotypes were reconstructed using the deterministic algorithm alleHap in the R programming environment. Based on prior T1DGC results in Caucasian population, haplotypes DRB1*0405-DQA1*0301-DQB1*0302, DRB1*0401-DQA1*0301-DQB1*0302, DRB1*0301-DQA1*0501-DQB1*0201, DRB1*0402-DQA1*0301-DQB1*0302 and DRB1*0404-DQA1*0301-DQB1*0302 were considered high-risk. DRB1*0701-DQA1*0201-DQB1*0303, DRB1*1401-DQA1*0101-DQB1*0503, DRB1*1501-DQA1*0102-DQB1*0602, DRB1*1101-DQA1*0501-DQB1*0301, DRB1*1104-DQA1*0501-DQB1*0301, DRB1*1303-DQA1*0501-DQB1*0301, DRB1*1301-DQA1*0103-DQB1*0603 and DRB1*0403-DQA1*0301-DQB1*0302 were considered protective. The distribution of protective, high-risk, and other haplotypes in the (first two) affected siblings and unaffected parents from Canarian and non-Canarian Spanish families was compared (Chi-square test). No significant differences were found between the regions in distribution of the HLA haplotypes in the affected siblings or in the non-affected parents. The high incidence of childhood-onset type 1 diabetes in the Canarian population does not appear to be explained by a greater prevalence of high-risk class II HLA haplotypes in families with the disease. However, sample size limits the differences that can be detected in this study. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Chemical characterization of milk oligosaccharides of the common wombat (Vombatus ursinus).

PubMed

Hirayama, Kentaro; Taufik, Epi; Kikuchi, Megumi; Nakamura, Tadashi; Fukuda, Kenji; Saito, Tadao; Newgrain, Keith; Green, Brian; Messer, Michael; Urashima, Tadasu

2016-09-01

Previous structural characterizations of marsupial milk oligosaccharides have been performed in the tammar wallaby, red kangaroo, koala, common brushtail possum and the eastern quoll. To clarify the homology and heterogeneity of milk oligosaccharides among marsupial species, which could provide information on their evolution, the oligosaccharides of wombat milk carbohydrate were characterized in this study. Neutral and acidic oligosaccharides were isolated from the carbohydrate fractions of two samples of milk of the common wombat and characterized by (1) H-nuclear magnetic resonance spectroscopy. The structures of six neutral saccharides were found to be Gal(β1-4)Glc (lactose), Gal(β1-3)Gal(β1-4)Glc (3'-galactosyllactose), Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc (3',3"-digalactosyllactose), Gal(β1-3)Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (galactosyl lacto-N-novopentaose I) and Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-novooctaose), while those of six acidic saccharides were Neu5Ac(α2-3)Gal(β1-3)Gal(β1-4)Glc. (sialyl 3'-galactosyllactose), Neu5Ac(α2-3)Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc (sialyl 3',3"-digalactosyllactose), Neu5Ac(α2-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose a), Gal(β1-3)[Neu5Ac(α2-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose c), Neu5Ac(α2-3)Gal(β1-3)Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc,, Neu5Ac(α2-3)Gal(β1-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc and Gal(β1-3)Gal(β1-3)[Neu5Ac(α2-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc. In addition, small amounts of sulfated oligosaccharides but no oligosaccharides containing Neu5Gc or α(2-6) linked Neu5Ac were detected. © 2015 Japanese Society of Animal Science.

Fourier transform emission spectroscopy of the B 1Π-X 1Sigma + , C 1Sigma + -X 1Sigma + , and G 1Π-X 1Sigma + systems of ScH and ScD

NASA Astrophysics Data System (ADS)

Ram, R. S.; Bernath, P. F.

1996-08-01

The emission spectra of ScH and ScD have been observed in the 380 nm-2.5 μm spectral region using a Fourier transform spectrometer. The molecules were excited in a scandium hollow cathode lamp operated with neon gas and a trace of hydrogen or deuterium. Three transitions with a common lower state, assigned as the ground X 1Σ+ state, have been observed in the near infrared and visible regions. The ScH bands with 0-0 band origins at 5404, 13 574, and 20 547 cm-1 have been assigned as the B 1Π-X 1Σ+, C 1Σ+-X 1Σ+, and G 1Π-X 1Σ+ transitions, respectively. A rotational analysis of the 0-0, 1-1, 1-0, and 2-1 bands of the B 1Π-X 1Σ+ system, the 0-0 and 1-1 bands of the C 1Σ+-X 1Σ+ system and the 0-0 band of the G 1Π-X 1Σ+ system has been obtained. The principal molecular constants for the X 1Σ+ state of ScH are ΔG(1/2)=1546.9730(14) cm-1, Be=5.425 432(48) cm-1, αe=0.124 802(84) cm-1 and re=1.775 427(8) Å. The corresponding band systems of ScD have also been analyzed. A rotational analysis of the 0-0, 1-1, and 1-0 bands of the B 1Π-X 1Σ+ system, the 0-0, 1-1, 0-1, and 1-2 bands of the C 1Σ+-X 1Σ+ system and the 0-0 band of the G 1Π-X 1Σ+ system has been obtained. The equilibrium molecular constants determined for the ground state of ScD are ωe=1141.2650(31) cm-1, ωexe=12.3799(15) cm-1, Be=2.787 432(41) cm-1, αe=0.045 321(73) cm-1, and re=1.771 219(13) Å. The ScH assignments are supported by recent theoretical predictions made by Anglada et al. [Mol. Phys. 66, 541 (1989)] as well as the experimental results available for ScF and the isovalent YH and LaH molecules. Although some unassigned bands have been attributed to ScH and ScD by previous workers, there have been no previous analyses of ScH or ScD spectra.

Content-Aware Adaptive Compression of Satellite Imagery Using Artificial Vision

DTIC Science & Technology

2013-09-01

j ) = L−1 ∑ k1=0 ( L...1 ∑ k2=0 f LL(g)(2i+ k1,2 j + k2) · lk2 ) · lk1 (3.3) f HL(g−1)(i, j ) = L−1 ∑ k1=0 ( L−1 ∑ k2=0 f LL(g)(2i+ k1,2 j + k2) ·hk2 ) · lk1 (3.4) f LH(g−1)(i... j ) = L−1 ∑ k1=0 ( L−1 ∑ k2=0 f LL(g)(2i+ k1,2 j + k2) · lk2 ) ·hk1 (3.5) f HH(g−1)(i, j ) = L−1 ∑ k1=0 ( L−1 ∑ k2=0 f LL(g)(2i+ k1,2 j + k2)