25,730 research outputs found
The church of St. Saturnino in Cagliari, Sardinia, reading the levels of history through the use of digital survey and the petrophysical study of materials
The most ancient church in Cagliari is dedicated to Saint Saturno (commonly named Saint Saturnino), the first indications about this church came from the sixth century, but the building arrived to our time is only a part of the original one and it rises over the ruins of previous structures, inside a a walled area with the presence of a Palaeo-Christian necropolis. The original Greek cross plan with a transept and a semi-spherical dome; has seen meaningful transformations in time, with the partial destruction of large parts of the building. All the four arms had a nave and two aisles, but the current church consists only of the dome-covered area and of the eastern arm, with a nave and two aisles. The whole church shows very interesting parts coming from previous architectures of the Roman age, a rich catalog of rich materials and details. In summer 2013, a collaboration between the Departments of Chemical and Geological Sciences from Cagliari and the one of Architecture from Florence brought to the realization of a detailed study about this ancient church. The whole building and its surrounding area were surveyed with the following methods: photography, 3D Laser Scanner for the whole interior and exterior parts, 3D photogrammetry of a selected set of stone surface samples, direct sampling of representative rocks for geochemical and petrophysical analysis. All data were then treated and analyzed to deepen the knowledge about the most meaningful aspects of different construction techniques and use of materials, provenance of raw materials, stone and structure alterations. As the result, a base was created to read common behaviors, design choices, recursive constructive solutions, and the “models” guiding the ancient intentions. This contribution will present the progress state of this research and its results
Marcatili's Lossless Tapers and Bends: an Apparent Paradox and its Solution
Numerical results based on an extended BPM algorithm indicate that, in
Marcatili's lossless tapers and bends, through-flowing waves are drastically
different from standing waves. The source of this surprising behavior is
inherent in Maxwell's equations. Indeed, if the magnetic field is correctly
derived from the electric one, and the Poynting vector is calculated, then the
analytical results are reconciled with the numerical ones. Similar
considerations are shown to apply to Gaussian beams in free space.Comment: 4 pages, figures include
Current and innovative pharmacological options to treat typical and atypical trigeminal neuralgia
Trigeminal neuralgia is a representative neuropathic facial pain condition, characterised by unilateral paroxysmal pain in the distribution territory of one or more divisions of the trigeminal nerve, triggered by innocuous stimuli. A subgroup of patients with trigeminal neuralgia [TN (previously defined as atypical TN)] also suffer from concomitant continuous pain, i.e. a background pain between the paroxysmal attacks. The aim of this review is to provide current, evidence-based, knowledge about the pharmacological treatment of typical and atypical TN, with a specific focus on drugs in development. We searched for relevant papers within PubMed, EMBASE, the Cochrane Database of Systematic Reviews and the Clinical Trials database (ClinicalTrials.gov), taking into account publications up to February 2018. Two authors independently selected studies for inclusions, data extraction, and bias assessment. Carbamazepine and oxcarbazepine are the first-choice drugs for paroxysmal pain. When sodium channel blockers cannot reach full dosage because of side effects, an add-on treatment with lamotrigine or baclofen should be considered. In patients with atypical TN, both gabapentin and antidepressants are expected to be efficacious and should be tried as an add-on to oxcarbazepine or carbamazepine. Although carbamazepine and oxcarbazepine are effective in virtually the totality of patients, they are responsible for side effects causing withdrawal from treatment in an important percentage of cases. A new, better tolerated, Nav1.7 selective state-dependent, sodium channel blocker (vixotrigine) is under development. Future trials testing the effect of combination therapy in patients with TN are needed, especially in patients with concomitant continuous pain and in TN secondary to multiple sclerosis
Progress in Small x Resummation
I review recent theoretical progress in the resummation of small x
contributions to the evolution of parton distributions, in view of its
potential significance for accurate phenomenology at future colliders. I show
that a consistent perturbative resummation of collinear and energy logs is now
possible, and necessary if one wishes to use recent NNLO results in the HERA
kinematic region.Comment: 8 pages, 6 figures, LaTeX with IJMPA document class, invited plenary
talk at the conference on QCD and hadronic physics, Beijing 200
Baryons and Skyrmions in QCD with Quarks in Higher Representations
We study the baryonic sector of QCD with quarks in the two index symmetric or
antisymmetric representation. The minimal gauge invariant state that carries
baryon number cannot be identified with the Skyrmion of the low energy chiral
effective Lagrangian. Mass, statistics and baryon number do not match. We
carefully investigate the properties of the minimal baryon in the large N limit
and we find that it is unstable under formation of bound states with higher
baryonic number. These states match exactly with the properties of the Skyrmion
of the effective Lagrangian.Comment: 23 pages, 13 figures. v2: minor changes. v3: corrected a mistake and
some typos. v4: modifyed the part about the stability of the Skyrmio
On the Hamilton's isoperimetric ratio in complete Riemannian manifolds of finite volume
We contribute to an original problem studied by Hamilton and others, in order
to understand the behaviour of maximal solutions of the Ricci flow both in
compact and non-compact complete orientable Riemannian manifolds of finite
volume. The case of dimension two has peculiarities, which force us to use
different ideas from the corresponding higher dimensional case. We show the
existence of connected regions with a connected complementary set (the
so-called "separating regions"). In dimension higher than two, the associated
problem of minimization is reduced to an auxiliary problem for the
isoperimetric profile. This is possible via an argument of compactness in
geometric measure theory. Indeed we develop a definitive theory, which allows
us to circumvent the shortening curve flow approach of previous authors at the
cost of some applications of geometric measure theory and Ascoli-Arzela's
Theorem.Comment: Example 5.4 is new; Theorem 4.5 is reformulated; 29 pages; 7 figure
De-Gaussification by inconclusive photon subtraction
We address conditional de-Gaussification of continuous variable states by
inconclusive photon subtraction (IPS) and review in details its application to
bipartite twin-beam state of radiation. The IPS map in the Fock basis has been
derived, as well as its counterpart in the phase-space. Teleportation assisted
by IPS states is analyzed and the corresponding fidelity evaluated as a
function of the involved parameters. Nonlocality of IPS states is investigated
by means of different tests including displaced parity, homodyne detection,
pseudospin, and displaced on/off photodetection. Dissipation and thermal noise
are taken into account, as well as non unit quantum efficiency in the detection
stage. We show that the IPS process, for a suitable choice of the involved
parameters, improves teleportation fidelity and enhances nonlocal properties.Comment: 17 pages, 30 figure
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