Selberg integrals in 1D random Euclidean optimization problems

We consider a set of Euclidean optimization problems in one dimension, where the cost function associated to the couple of points $x$ and $y$ is the Euclidean distance between them to an arbitrary power $p\ge1$, and the points are chosen at random with flat measure. We derive the exact average cost for the random assignment problem, for any number of points, by using Selberg's integrals. Some variants of these integrals allows to derive also the exact average cost for the bipartite travelling salesman problem.Comment: 9 pages, 2 figure

Asthma worsened by benzoate contained in some antiasthmatic drugs.

Here, we report our experience on benzoate hypersensitivity. Drug and food additives are known to induce pseudo-allergic reactions such as urticaria, eczema, asthma and rhinitis. These reactions are often under-diagnosed, above all in allergic patients treated with additive containing drugs. On the contrary, attention to additives present in some drug formulations and foods may often permit more correct diagnosis

Serum IL-17 after one course of sublingual immunotherapy in allergic rhinitis to birch

Recently, it has been reported that IL-17 may be involved in allergic reaction. Sublingual immunotherapy (SLIT) is the unique curative treatment for allergic rhinitis. This study aims at investigating whether one course of birch SLIT could affect serum IL-17 levels. The findings provided show that some IL-17 producer patients had a reduction of serum IL-17 levels after one SLIT course. Therefore, this preliminary study shows that a single pre-seasonal SLIT course may induce a significant decreasing trend in serum IL-17 levels; further study should be carried out to define the role exerted by IL-17 in allergic rhinitis

Longitudinal twinning in a TiAl alloy at high temperature by in situ microcompression

The stress required to activate twinning of the longitudinal <11bar2]{111} system in the lamellar γ-TiAl phase of the alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol.% TiB2 was measured at several temperatures up to 700 ºC by in situ micropillar compression of soft mode oriented γ-TiAl/α2-Ti3Al lamellar stacks. The lamellae undergoing deformation twinning were identified by electron backscatter diffraction orientation mapping. In some cases, such lamellae were not constrained by domain or colony boundaries and longitudinal twinning was the only deformation mechanism observed based on digital image correlation strain maps. The resolved shear stress for such unconstrained twinning was found to increase monotonically with temperature from 25 ºC to 700 ºC. This is consistent with the stacking fault energy increasing with temperature as found in many metallic alloys, suggesting that the increased ease of deformation twinning at high temperature in bulk TiAl alloys is due to the increased ease with which the twinning shear can be accommodated by the neighbouring domains and lamellae with increasing temperature, rather than a thermal softening of the intrinsic twinning mechanism

The KLASH Proposal

We propose a search of galactic axions with mass about 0.2 µeV using a large volume resonant cavity, about 50 m3, cooled down to 4 K and immersed in a moderate axial magnetic field of about 0.6 T generated inside the superconducting magnet of the KLOE experiment [1] located at the National Laboratory of Frascati of INFN. This experiment, called KLASH (KLoe magnet for Axion SearcH) in the following, has a potential sensitivity on the axion-to-photon coupling, gaγγ, of about 6 × 10−17 GeV−1, reaching the region predicted by KSVZ [2] and DFSZ [3] models of QCD axions

Deformation of lamellar γ-TiAl below the general yield stress

The occurrence of plasticity below the macroscopic yield stress during tensile monotonic loading of nearly lamellar Ti-45Al-2Nb-2Mn(at%)-0.8vol% TiB2 at both 25 °C and 700 °C, and in two conditions of lamellar thickness, was measured by digital image correlation strain mapping of a remodelled Au surface speckle pattern. Such initial plasticity, not necessarily related to the presence of common stress concentrators such as hard particles or cracks, could occur at applied stresses as low as 64 % of the general yield stress. For a same applied strain it was more prominent at room temperature, and located as slip and twinning parallel to, and near to or at (respect.) lamellar interfaces of all types in soft modeoriented colonies. These stretched the full colony width and the shear strain was most intense in the centre of the colonies. Further, the most highly operative microbands of plasticity at specimen fracture were not those most active prior to yielding. The strain mapping results from polycrystalline tensile loading were further compared to those from microcompression testing of soft-mode stacks of lamellae milled from single colonies performed at the same temperatures. Combined with post-mortem transmission electron microscopy of the pillars, the initial plasticity by longitudinal dislocation glide was found to locate within 30 – 50 nm of the lamellar interfaces, and not at the interfaces themselves. The highly localised plasticity that precedes high cycle fatigue failure is therefore inherently related to the lamellar structure, which predetermines the locations of plastic strain accumulation, even in a single loading cycle.The work was supported by the EPSRC / Rolls-Royce Strategic Partnership (EP/M005607/1). T.E.J.E. also acknowledges the kind support of the Worshipful Company of Armourers and Brasiers’ Gauntlet Trust

Axion search with a quantum-limited ferromagnetic haloscope

A ferromagnetic axion haloscope searches for Dark Matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter YIG spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin-magnetometer ever realized. The minimum detectable field is $5.5\times10^{-19}\,$T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant $g_{aee}\le1.7\times10^{-11}$ at 95% CL. The scientific run of our haloscope resulted in the best limit on DM-axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion mass range $42.4$-$43.1\,\mu$eV. This is also the first apparatus to perform an axion mass scanning by changing the static magnetic field.Comment: 4 pages, 4 figure

Searching for galactic axions through magnetized media: QUAX status report

The current status of the QUAX R\&D program is presented. QUAX is a feasibility study for a detection of axion as dark matter based on the coupling to the electrons. The relevant signal is a magnetization change of a magnetic material placed inside a resonant microwave cavity and polarized with a static magnetic field.Comment: Contributed to the 13th Patras Workshop on Axions, WIMPs and WISPs, Thessaloniki, May 15 to 19, 201