Dilution Jet Behavior in the Turn Section of a Reverse Flow Combuster

Measurements of the temperature field produced by a single jet and a row of dilution jets issued into a reverse flow combustor are presented. The temperature measurements are presented in the form of consecutive normalized temperature profiles, and jet trajectories. Single jet trajectories were swept toward the inner wall of the turn, whether injection was from the inner or outer wall. This behavior is explained by the radially inward velocity component necessary to support irrotational flow through the turn. Comparison between experimental results and model calculations showed poor agreement due to the model's not including the radial velocity component. A widely spaced row of jets produced trajectories similar to single jets at similar test conditions, but as spacing ratio was reduced, penetration was reduced to the point where the dilution jet flow attached to the wall

Strong 3p -T1u Hybridization in Ar@C60

Multilayers of fullerenes with and without endohedral Ar units, C60 and Ar@C60, were investigated by photoemission and density functional theory. The stoichiometry and the endohedral nature of Ar is checked by x-ray photoelectron spectroscopy and x-ray photoelectron diffraction. Valence band ultraviolet photoemission spectra show a strong hybridisation of the Ar 3p valence shell with the 6T1u molecular orbital of C60. A hybridisation gap of 1.6 +/- 0.2 eV is found. This is in agreement with density functional theory (DFT) that predicts 1.47 eV, and indicates Ar@C60 to be a noble gas compound with a strong coupling between Ar and the C60 cage. No giant Ar photoemission cross section as predicted for the gas phase in [Phys. Rev. Lett. 99, 243003 (2007)] was found

Resonant Photoelectron Diffraction with circularly polarized light

Resonant angle scanned x-ray photoelectron diffraction (RXPD) allows the determination of the atomic and magnetic structure of surfaces and interfaces. For the case of magnetized nickel the resonant L2 excitation with circularly polarized light yields electrons with a dichroic signature from which the dipolar part may be retrieved. The corresponding L2MM and L3MM Auger electrons carry different angular momenta since their source waves rotate the dichroic dipole in the electron emission patterns by distinct angles

The Interaction of an Oblique Shock Wave with a Laminar Boundary Layer

The results of some experimental and theoretical studies of the interaction of oblique shock waves with laminar boundary layers are presented. Detailed measurements of pressure distribution, shear distribution, and velocity profiles were made during the interaction of oblique shock waves with laminar boundary layers on a flat plate. From these measurements a model was derived to predict the pressure levels characteristic of separation and the length of the separated region

Unit cell of graphene on Ru(0001): a 25 x 25 supercell with 1250 carbon atoms

The structure of a single layer of graphene on Ru(0001) has been studied using surface x-ray diffraction. A surprising superstructure has been determined, whereby 25 x 25 graphene unit cells lie on 23 x 23 unit cells of Ru. Each supercell contains 2 x 2 crystallographically inequivalent subcells caused by corrugation. Strong intensity oscillations in the superstructure rods demonstrate that the Ru substrate is also significantly corrugated down to several monolayers, and that the bonding between graphene and Ru is strong and cannot be caused by van der Waals bonds. Charge transfer from the Ru substrate to the graphene expands and weakens the C-C bonds, which helps accommodate the in-plane tensile stress. The elucidation of this superstructure provides important information in the potential application of graphene as a template for nanocluster arrays.Comment: 9 pages, 3 figures, paper submitted to peer reviewed journa

Emission of exoelectrons during oxidation of Cs via thermal activation of a metastable O^-₂ surface species

Exposure of Cs surfaces to O2 causes the emission of exoelectrons. With a Cs monolayer on Ru(0001) the maximum yield is observed with an already partly oxidized surface on which a metastable O-2 species could be identified. Thermally activated transformation (with an activation energy of 0.8 eV) of this phase leads to dissociation accompanied by exoelectron emission via Auger deexcitation

Macropinocytotic uptake and infection of human epithelial cells with species B2 adenovirus type 35

The human adenovirus serotype 35 (HAdV-35, short Ad35) causes kidney and urinary tract infections, and infects respiratory organs of immunocompromised individuals. Unlike other adenoviruses, Ad35 has a low seroprevalence which makes Ad35-based vectors promising candidates for gene therapy. Ad35 utilizes CD46 and integrins as receptors for infection of epithelial and hematopoietic cells. Here, we show that infectious entry of Ad35 into HeLa, human kidney HK-2 cells and normal human lung fibroblasts strongly depended on CD46 and integrins but not heparan sulfate, and variably required the large GTPase dynamin. Ad35 infections were independent of expression of the carboxy-terminal domain of AP180 which effectively blocks clathrin-mediated uptake. Ad35 infections were inhibited by small chemicals against the serine/threonine kinase Pak1 (p21-activated kinase), protein kinase C (PKC), sodium-proton exchangers, actin and acidic organelles. Remarkably, the F-actin inhibitor jasplakinolide, the Pak1 inhibitor IPA-3 or the sodium-proton exchange inhibitor EIPA blocked the endocytic uptake of Ad35. Dominant-negative proteins or small interfering RNAs against factors driving macropinocytosis, including the small GTPase Rac1, Pak1 or the Pak1 effector C-terminal binding protein 1 (CtBP1) potently inhibited Ad35 infection. Confocal laser scanning microscopy, electron microscopy and live cell imaging showed that Ad35 colocalized with fluid phase markers in large endocytic structures that were positive for CD46, alpha v integrins and also CtBP1. Our results extend earlier observations with HAdV-3 (Ad3), and establish macropinocytosis as an infectious pathway for species B human adenoviruses in epithelial and hematopoietic cells

Differential Photoelectron Holography: A New Approach for Three-Dimensional Atomic Imaging

We propose differential holography as a method to overcome the long-standing forward-scattering problem in photoelectron holography and related techniques for the three-dimensional imaging of atoms. Atomic images reconstructed from experimental and theoretical Cu 3p holograms from Cu(001) demonstrate that this method suppresses strong forward-scattering effects so as to yield more accurate three-dimensional images of side- and back-scattering atoms.Comment: revtex, 4 pages, 2 figure

Temperature dependence of the Kondo resonance and its satellites in CeCu_2Si_2

We present high-resolution photoemission spectroscopy studies on the Kondo resonance of the strongly-correlated Ce system CeCu$_2$Si$_2$. Exploiting the thermal broadening of the Fermi edge we analyze position, spectral weight, and temperature dependence of the low-energy 4f spectral features, whose major weight lies above the Fermi level $E_F$. We also present theoretical predictions based on the single-impurity Anderson model using an extended non-crossing approximation (NCA), including all spin-orbit and crystal field splittings of the 4f states. The excellent agreement between theory and experiment provides strong evidence that the spectral properties of CeCu$_2$Si$_2$ can be described by single-impurity Kondo physics down to $T \approx 5$ K.Comment: 4 pages, 3 figure

A duality of generalized metric spaces

AbstractWe develop a duality theory for Lawvereʼs generalized metric spaces that extends the Lawson duality for continuous dcpos and open filter reflecting maps: we prove that the category of relatively cocomplete and continuous [0,∞]-categories considered with open filter reflecting maps is self-dual