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Civil War and Civil War Related Prints : Col B Grierson, 6Th Ill C...

By: Michael Cáceres and Giron
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Journal of Applied Physics : Phase transformation sequence and mag...

By: X. Y. Xiong and T. R. Finlayson

Description: The phase transformation sequence, microstructure and compositions, and magnetic properties for a melt-spun Sm(Co0.68Fe0.2Cu0.1Zr0.02)7.5 alloy after isochronal heat treatments have been studied by using x-ray diffraction, transmission electron microscopy, three-dimensional atom probe (3DAP), and magnetometry. The as-spun ribbons had a single phase with the Cu7Tb structure. After being aged at 720 °C, the single phase decomposed into two major phases: 2:17R ...

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Review of Scientific Instruments : Heat-capacity measurements on s...

By: J. C. P. Klaasse and E. H. Bruck

Description: A newly developed method is presented for measuring heat capacities on small samples, particularly where thermal isolation is not sufficient for the use of the traditional semiadiabatic heat-pulse technique. This “hybrid technique” is a modification of this heat-pulse method in case the temperature drift of the sample after the heat pulse is not linear but exponential. Deliberate extrapolations of these exponential drift curves, dependent on the evaluated re...

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Journal of Applied Physics : Equivalent magnetic charge in helicoi...

By: Roberto Muscia

Description: In this paper we show that magnetostatic models of permanent magnets, based on distributions of magnetic charge and shaped by a helicoidal geometry of cylindrical type, have the volume charge density ρM equal to zero. This result is valid when (i) the modulus of the vector physical magnetization density M has a constant value in all the points of the helicoidal magnet and (ii) M has the same direction of an oriented straight line having a constant angle with...

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Review of Scientific Instruments : Development of a scanning surfa...

By: Kent A. Meyer, Olga Ovchinnikova, Kin Ng, and Douglas E. Goeringer

Description: We report on the development of a versatile scanning apparatus for nanoscale surface sampling that utilizes the interaction of laser radiation at a sharp probe tip to effect desorption/ablation on opaque substrates. The process, which currently yields surface craters as small as ∼ 50 nm diameter×5 nm deep, has been demonstrated with both metal-coated and bare silicon tips. Desorption/ablation under the tip occurs at illumination intensities below the corresp...

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Physics of Plasmas : Demonstration of detuning and wavebreaking ef...

By: N. A. Yampolsky, N. J. Fisch, V. M. Malkin, E. J. Valeo, R. Lindberg et al

Description: A plasma-based resonant backward Raman amplifier/compressor for high power amplification of short laser pulses might, under ideal conditions, convert as much as 90% of the pump energy to the seed pulse. While the theoretical highest possible efficiency of this scheme has not yet been achieved, larger efficiencies than ever before obtained experimentally (6.4%) are now being reported, and these efficiencies are accompanied by strong pulse compression. Based o...

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Review of Scientific Instruments : Semicircular bend testing with ...

By: F. Dai, K. Xia, and S. N. Luo

Description: We propose and validate an indirect tensile testing method to measure the dynamic tensile strength of rocks and other brittle solids: semicircular bend (SCB) testing with a modified split Hopkinson pressure bar (SHPB) system. A strain gauge is mounted near the failure spot on the specimen to determine the rupture time. The momentum trap technique is utilized to ensure single pulse loading for postmortem examination. Tests without and with pulse shaping are c...

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Physics of Fluids : Multimode analysis of bubble growth in saturat...

By: G. Tomar, G. Biswas, A. Sharma, and S. W. J. Welch

Description: The bubble formation sites in film boiling are the nodes of the instability occurring at the liquid-vapor interface. We perform a linear stability analysis with a time dependent base state, accounting for the growth of the film due to evaporation, in order to identify the most dominant wavelength. Choosing a domain size of five times the wavelength predicted by Berenson [ASME J. Heat Transfer 83, 351 (1961) ] and an initial liquid-vapor interface profile hav...

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Biblioteca Hispanica : the Man Considered in Its Relations and Und...

By: Rafael Martinez and Molina
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Review of Scientific Instruments : Imaging piezospectroscopy

By: John B. Abbiss and Bauke Heeg

Description: A novel instrument is described for obtaining accurate high-resolution residual stress images of aluminum oxide materials, based on the piezospectroscopy of Cr3+ dopant ions. The instrument employs a charge coupled device camera, a narrow bandpass tunable filter and the use of Tikhonov regularization for reconstruction of the raw spectral data. The experimental accuracy and spectral shift resolution of this method were analyzed with two calibration light sou...

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Journal of Applied Physics : Effect of grain refinement on enhanci...

By: A. Malagoli, V. Braccini, M. Tropeano, M. Vignolo, C. Bernini et al

Description: Ex situ powder-in-tube MgB2 tapes prepared with ball-milled, undoped powders showed a strong enhancement of the irreversibility field H∗, the upper critical field Hc2, and the critical current density Jc(H) together with the suppression of the anisotropy of all of these quantities. Jc reached 104 A/cm2 at 4.2 K and 10 T, with an irreversibility field of about 14 T at 4.2 K, and Hc2 of 9 T at 25 K, high values for not-doped MgB2. The enhanced Jc and H∗ values...

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Physics of Fluids : Selection of the divergence waves on a model v...

By: V. P. Reutov and G. V. Rybushkina

Description: The paper is concerned with the established regimes of generation of the divergence (quasistatic) waves on a model viscoelastic coating under a potential flow of an incompressible liquid. Parameters of the effective coating that consists of a strongly damped flexible plate supported by an extended spring foundation are evaluated using the condition of modeling the deformation of the viscoelastic layer of a rubberlike material in the available experiments. Th...

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Journal of Applied Physics : Mechanisms of the ultrasonic modulati...

By: Baohong Yuan, John Gamelin, and Quing Zhu

Description: To understand the modulation mechanisms of fluorescence emission induced by ultrasonic waves in turbid media, a mathematical model is proposed and compared with the recent experimental observations of Kobayashi et al. [Appl. Phys. Lett. 89, 181102 (2006) ]. Modulation of fluorophore concentration is considered as the source of the oscillation of fluorescence signals when fluorophore concentration is low enough so that quenching effects can be ignored. By sol...

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Review of Scientific Instruments : Universal serial bus powered an...

By: Mark R. Holcomb, Robel Y. Bekele, Eduardo A. Lima, and John P. Wikswo

Description: We have developed a compact, isolated, physiological, constant-current stimulator that is powered and controlled by a universal serial bus (USB) interface. The stimulator is designed to be used in ex vivo cardiac experiments but is suitable for a wide variety of settings. The cost and features compare very favorably with commercial stimulators usually used in research and student laboratories. In addition to being USB powered, other novel aspects of our stim...

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Review of Scientific Instruments : A new spin-polarized photoemiss...

By: Taichi Okuda, Yasuo Takeichi, Yuuki Maeda, Ayumi Harasawa, Iwao Matsuda et al

Description: A new spin- and angle-resolved photoemission spectrometer was developed adopting the very-low-energy-electron-diffraction (VLEED)-type spin polarimeter. The Fe(001)p(1×1)–O film grown on MgO(001) crystal for the VLEED target yields significantly high spin-resolving power, the effective Sherman function of 0.40±0.02, with long lifetime and stability compared to the conventional Fe(001) target. Under the favor of high resolving power, approximately 100 times h...

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Biblioteca Hispanica : Mechanical Applied to Constructions

By: Joseph Marva and Mayer
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Applied Physics Letters : Bandgap engineering by tuning particle s...

By: M. B. Sahana, C. Sudakar, G. Setzler, A. Dixit, J. S. Thakur et al

Description: We report the structural and optical properties of xSnO2–yFe2O3 nanocrystalline composite thin films. SnO2 and Fe2O3 exhibit strong phase separation instability and their particle size and crystallinity are tunable by changing their composition and annealing temperature. The bandgap for these composites continuously increases from 2.3 to 3.89 eV. We discuss the increasing bandgap values in terms of the quantum confinement effect manifested by the decreasing ...

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Chaos : Filtering by nonlinear systems

By: E. Campos Cantón, J. S. González Salas, and J. Urías

Description: Synchronization of nonlinear systems forced by external signals is formalized as the response of a nonlinear filter. Sufficient conditions for a nonlinear system to behave as a filter are given. Some examples of generalized chaos synchronization are shown to actually be special cases of nonlinear filtering.

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Applied Physics Letters : Ferromagnetic structurally disordered Zn...

By: K. Potzger, Shengqiang Zhou, Qingyu Xu, A. Shalimov, R. Groetzschel et al

Description: We present superparamagnetic clusters of structurally highly disordered Co–Zn–O created by high fluence Co ion implantation into ZnO (0001) single crystals at low temperatures. This secondary phase cannot be detected by common x-ray diffraction but is observed by high-resolution transmission electron microscopy. In contrast to many other secondary phases in a ZnO matrix, it induces low-field anomalous Hall effect and is thus a candidate for magnetoelectronics applications.

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Applied Physics Letters : Positive ion polymerization in hydrogen ...

By: S. Nunomura and M. Kondo

Description: Mass spectra of positive ions (cations) and neutrals have been measured in hydrogen diluted silane plasmas at gas pressures of 0.1–10 Torr. The mass spectrum of ions changes with the pressure, while that of neutrals maintains a similar shape. The dominant ion species varies from a hydrogen ion group at ≤0.5 Torr to a monosilicon hydride ion group at ≈0.5–1 Torr and polysilicon hydride ion groups at ≥1 Torr, which is determined from ionization channels and c...

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