An Investigation into the Effect of the Shell on SALM Processed Parts

Shell Assisted Layer Manufacturing (SALM) is a novel process for rapid prototyping/ tooling/ manufacture (RP/RT/RM) which is presently undergoing feasibility studies. SALM is based on layered manufacturing technology (LMT). Initially it develops the shell (boundaries) of a selected layer using a technique similar to fused deposition modelling (FDM). The developed shell is filled with a UV curable resin and is exposed to UV radiation for curing. This procedure is repeated until the complete part is built. This paper compares and contrasts properties of parts made using two options available with the SALM technique: building the part using a soluble shell (FDM support structure material, finally dissolved to recover the part); or using a polymer material such as ABS that is bonded with the resin whilst making the part.Mechanical Engineerin

Communicating via ignorance: Increasing communication capacity via superposition of order

Classically, no information can be transmitted through a depolarising, that is a completely noisy, channel. We show that by combining a depolarising channel with another channel in an indefinite causal order---that is, when there is superposition of the order that these two channels were applied---it becomes possible to transmit significant information. We consider two limiting cases. When both channels are fully-depolarising, the ideal limit is communication of 0.049 bits; experimentally we achieve $(3.4{\pm}0.2){\times}10^{-2}$ bits. When one channel is fully-depolarising, and the other is a known unitary, the ideal limit is communication of 1 bit. We experimentally achieve 0.64${\pm}$0.02 bits. Our results offer intriguing possibilities for future communication strategies beyond conventional quantum Shannon theory

Directional pinning and anisotropy in YBa2Cu3O7-x with BaZrO3 nanorods: intrinsic and nanorods-induced anisotropy

We present a study of the anisotropic vortex parameters as obtained from measurements of the microwave complex resistivity in the vortex state with a tilted applied magnetic field in YBa2Cu3O7-x thin films with BaZrO3 nanorods. We present the angular dependence of the vortex viscosity $\eta$, the pinning constant k_p and the upper limit for the creep factor \chi_M. We show that the directional effect of the nanorods is absent in \eta, which is dictated by the mass anisotropy \gamma. By contrast, pinning-mediated properties are strongly affected by the nanorods. It is significant that the pinning and creep affected by the nanorods is detectable also at our very high operating frequency, which implies very short-range displacements of the vortices from their equilibrium position.Comment: Proceedings of VORTEX VIII Conference, to be published in Physica

Non(anti)commutative superspace with coordinate-dependent deformation

We consider non(anti)commutative superspace with coordinate dependent deformation parameters $C^{\alpha\beta}$. We show that a chiral ${\cal N}=1/2$ supersymmetry can be defined and that chiral and antichiral superfields are still closed under the Moyal-Weyl associative product implementing the deformation. A consistent ${\cal N}=1/2$ Super Yang-Mills deformed theory can be constructed provided $C^{\alpha\beta}$ satisfies a suitable condition which can be connected with the graviphoton background at the origin of the deformation. After adding matter we also discuss the Konishi anomaly and the gluino condensation.Comment: References added. Accepted for publication in PR

More pieces of the puzzle: Chemistry and substructures in the Galactic thick disk

We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the Copenhagen-Geneva Survey by Helmi et al. (2006). We find that the stars with these dynamical characteristics do not constitute a homogeneous population. A relatively sharp transition in dynamical and chemical properties appears to occur at a metallicity of [Fe/H] ~ -0.4. Stars with [Fe/H] > -0.4 have mostly lower eccentricities, smaller vertical velocity dispersions, are alpha-enhanced and define a rather narrow sequence in [alpha/Fe] vs [Fe/H], clearly distinct from that of the thin disk. Stars with [Fe/H] < -0.4 have a range of eccentricities, are hotter vertically, and depict a larger spread in [alpha/Fe]. We have also found tentative evidence of substructure possibly associated to the disruption of a metal-rich star cluster. The differences between these populations of stars is also present in e.g. [Zn/Fe], [Ni/Fe] and [SmII/Fe], suggesting a real physical distinction.Comment: Astrophysical Journal in press. 5 pages, 4 figure

Anisotropy and directional pinning in YBaCuO with BaZrO3 nanorods

Measurements of anisotropic transport properties (dc and high-frequency regime) of driven vortex matter in YBa$_2$Cu$_3$O$_{7-x}$ with elongated strong-pinning sites (c-axis aligned, self-assembled BaZrO$_3$ nanorods) are used to demonstrate that the effective-mass angular scaling takes place only in intrinsic physical quantities (flux-flow resistivity), and not in pinning-related Labusch parameter and critical currents. Comparison of the dynamics at different time scales shows evidence for a transition of the vortex matter toward a Mott phase, driven by the presence of nanorods. The strong pinning in dc arises partially from a dynamic effect.Comment: 4 pages, 4 figures. Accepted for publication on Applied Physics Letters. With respect to v1: changed title, slightly shortene