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  • Stellar models of multiple populations in globular clusters - I. The main sequence of NGC 6752 

    Dotter, Aaron; Ferguson, Jason W.; Conroy, Charlie; Milone, A. P.; Marino, A. F.; Yong, David (Oxford University Press, 2015-01-11)
    We present stellar atmosphere and evolution models of main-sequence stars in two stellar populations of the Galactic globular cluster NGC 6752. These populations represent the two extremes of light-element abundance ...
  • Fischer-Tropsch synthesis: activity and selectivity of chi-Fe5C2 and circle minus-Fe3C carbides 

    Gnanamani, Muthu Kumaran; Hamdeh, Hussein H.; Jacobs, Gary; Shafer, Wilson D.; Sparks, Dennis E.; Keogh, Robert A.; Davis, Burtron H. (American Chemical Society, 2014-08-10)
    Two different iron carbides, Hägg (χ-Fe5C2) and cementite (ϴ-Fe3C) for Fischer-Tropsch synthesis (FTS) was investigated. Both iron carbides were oxidized to Fe3O4 ​during FTS. Hägg carbide (χ-Fe5C2), initially exhibits ...
  • H-spaces, loop spaces and the space of positive scalar curvature metrics on the sphere 

    Walsh, Mark (Mathematical Sciences Publishers, 2014-10-02)
    For dimensions n >= 3, we show that the space Riem(+)(S-n) of metrics of positive scalar curvature on the sphere S-n is homotopy equivalent to a subspace of itself which takes the form of an H-space with a homotopy ...
  • The space of positive scalar curvature metrics on a manifold with boundary 

    Walsh, Mark (2014-11-12)
    We study the space of Riemannian metrics with positive scalar curvature on a compact manifold with boundary. These metrics extend a fixed boundary metric and take a product structure on a collar neighbourhood of the boundary. ...
  • Increasing stability for determining the potential in the Schrodinger equation with attenuation from the Dirichlet-to-Neumann map 

    Isakov, Victor, 1947-; Wang, Jenn-Nan (American Institute of Mathemaical Sciences, 2014-11)
    We derive some bounds which can be viewed as an evidence of increasing stability in the problem of recovering the potential coefficient in the Schrodinger equation from the Dirichlet-to-Neumann map in the presence of ...
  • Recovery of time dependent volatility coefficient by linearization 

    Isakov, Victor, 1947- (American Institute of Mathematical Sciences, 2014-03)
    We study the problem of reconstruction of special time dependent local volatility from market prices of options with different strikes at two expiration times. For a general diffusion process we apply the linearization ...
  • Structural analysis and cations distribution of nanocrystalline Ni1-xZnxFe1.7Ga0.3O4 

    Heiba, Zein K.; Mohamed, Mohamed Bakr; Hamdeh, Hussein H.; Ahmed, M. A. (Elsevier B.V., 2014-09-09)
    Nanostructured Ni1-xZnxFe1.7Ga0.3O4, with x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 were prepared by citrate method and were investigated using X-ray diffraction and Mossbauer spectroscopy. The structure characterized using X-ray ...
  • Improved asymptotics of a decreasing mean residual life estimator 

    Lorenzo, Edgardo; Mukerjee, Hari (Taylor & Francis Group, 2014-09-17)
    The mean residual life of a life distribution, X, with a finite mean is defined by M(t) = E[X - t|X > t] for t > 0. Kochar etal. (2000) provided an estimator of M when it is assumed to be decreasing. They showed that its ...
  • Applications of the h-Cobordism Theorem 

    Burkemper, Matthew Bryan (Wichita State University, 2014-05)
    We provide an exposition of J. Milnor's proof of the h-Cobordism Theorem. This theorem states that a smooth, compact, simply connected n-dimensional manifold W with n greater than or equal to 6, whose boundary boundaryW ...
  • Geometry of horizontal bundles and connections 

    Ryan, Justin M. (Wichita State University, 2014-05)
    An Ehresmann connection on a fiber bundle pi: E --> M is defined by prescribing a suitable horizontal subbundle H of the tangent bundle piT: TE --> E. For a horizontal bundle to be suitable, it must have a property called ...
  • Isochrones for old (> 5 GYR) stars and stellar populations. I. models for-2.4 <= [Fe/H] <=+0.6, 0.25 <= Y <= 0.33, and-0.4 <= [alpha/Fe] <=+0.4 

    VandenBerg, Don A.; Bergbusch, Peter A.; Ferguson, Jason W.; Edvardsson, Bengt (IOP Publishing, 2014-10-10)
    Canonical grids of stellar evolutionary sequences have been computed for the helium mass-fraction abundances Y = 0.25, 0.29, and 0.33, and for iron abundances that vary from 2.4 to +0.4 (in 0.2 dex increments) when [alpha/Fe] ...
  • Fischer-Tropsch synthesis: morphology, phase transformation, and carbon-layer growth of iron-based catalysts 

    Pendyala, Venkat Ramana Rao; Graham, Uschi M.; Jacobs, Gary; Hamdeh, Hussein H.; Davis, Burtron H. (John Wiley & Sons, Inc., 2014-07)
    The morphological, phase transformations and carbon-layer growth for unpromoted and K-promoted iron catalysts were investigated over time during Fischer-Tropsch synthesis. Catalysts were activated in CO for 24 h, which ...
  • Fischer-Tropsch synthesis: deactivation as a function of potassium promoter loading for precipitated iron catalyst 

    Pendyala, Venkat Ramana Rao; Graham, Uschi M.; Jacobs, Gary; Hamdeh, Hussein H.; Davis, Burtron H. (Springer, 2014-10)
    The effect of potassium promoter loading (0, 0.5, 1.0 and 2.0 atomic ratio) on the performance of precipitated iron catalysts was investigated during Fischer-Tropsch synthesis using a continuously stirred tank reactor. ...
  • Horizontal bundles and connections 

    Ryan, Justin M. (Wichita State University. Graduate School, 2014-04-25)
    A manifold is a mathematical space that locally resembles standard Euclidean space. In order to study the geometry of such a space, it is necessary to prescribe a connection on the manifold. A connection describes how ...
  • Fischer-Tropsch synthesis: effect of activation gas after varying Cu promoter loading over K-promoted Fe-based catalyst 

    Pendyala, Venkat Ramana Rao; Jacobs, Gary; Hamdeh, Hussein H.; Shafer, Wilson D.; Sparks, Dennis E.; Hopps, Shelley; Davis, Burtron H. (© Springer, 2014-09)
    The effects of activation gas and copper promoter loading on the Fischer-Tropsch synthesis performance of potassium promoted precipitated iron-based catalysts were investigated using a continuously stirred tank reactor. ...
  • Measurement of charged pion production yields off the NuMI target 

    Paley, J. M.; Messier, M. D.; Raja, R.; Akgun, U.; Asner, D. M.; Aydin, G.; Baker, W.; Barnes, P. D. Jr; Bergfeld, T.; Beverly, L.; Bhatnagar, V.; Choudhary, B.; Dukes, E. C.; Duru, F.; Feldman, G. J.; Godley, A.; Graf, N.; Gronberg, J.; Gulmez, E.; Gunaydin, Y. O.; Gustafson, H. R.; Hartouni, E. P.; Hanlet, P.; Heffner, M.; Kaplan, D. M.; Kamaev, O.; Klay, J.; Kumar, A.; Lange, D. J.; Lebedev, A.; Ling, J.; Longo, M. J.; Lu, L. C.; Materniak, C.; Mahajan, S.; Meyer, H.; Miller, D. E.; Mishra, S. R.; Nelson, K.; Nigmanov, T.; Norman, A.; Onel, Y.; Penzo, A.; Peterson, R. J.; Rajaram, D.; Ratnikov, D.; Rosenfeld, C.; Rubin, H.; Seun, S.; Singh, A.; Solomey, Nickolas; Soltz, R. A.; Torun, Y.; Wilson, K.; Wright, D. M.; Wu, Q. K. (American Physical Society, 2014-09)
    The fixed-target Main Injector Particle Production (MIPP) experiment, Fermilab E907, was designed to measure the production of hadrons from the collisions of hadrons of momenta ranging from 5 to 120 GeV/c on a variety of ...
  • Synthesis of highly ordered 30 nm NiFe2O4 particles by the microwave-combustion method 

    Mahmoud, Mohamed H.; Elshahawy, A. M.; Makhlouf, Salah A.; Hamdeh, Hussein H. (Elsevier B.V., 2014-11)
    NiFe2O4 of 30 nm average size was synthesized by microwave combustion and subsequent solid state reaction at 1273 K. The materials were characterized by X-ray diffraction, TEM, vibrating sample magnetometery and Mossbauer ...
  • Point vortex model for asymmetric inviscid wakes past bluff bodies 

    Elcrat, Alan R.; Ferlauto, M.; Zannetti, L. (IOP Publishing, 2014-05-27)
    Wakes past bluff bodies are modeled by means of point vortices standing in equilibrium. The consistency of the adopted model is discussed with respect to the asymptotic model proposed by Batchelor. It is shown that, in ...
  • Spectra of unitary integral operators on L-2 (R) with kernels k(xy) 

    Ma, Daowei; Chen, Goong (World Scientific, 2013)
    Unitary integral transforms play an important role in mathematical physics. A primary example is the Fourier transform whose kernel is of the form k(x, y) = k(xy), i.e., of the product type. Here we consider the determination ...
  • Some observations regarding steady laminar flows past bluff bodies 

    Fornberg, Bengt; Elcrat, Alan R. (Royal Society, 2014-07-28)
    Steady laminar flows past simple objects, such as a cylinder or a sphere, have been studied for well over a century. Theoretical, experimental and numerical methods have all contributed fundamentally towards our understanding ...

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