Commissioning of the Inner Tracker of the KLOE-2 experiment

The KLOE-2 experiment is undergoing commissioning at the DA$\Phi$NE $e^{+}e^{-}$ collider of the Frascati National Laboratory of the INFN, after the integration of new detectors in the former KLOE apparatus. The Inner Tracker, a very light detector (material budget $<2\%X_{0}$), is one of the new subdetectors and it is composed of 4 cylindrical triple-GEM with a stereo X-V strips/pads readout. The commissioning phase of the Inner Tracker consists in the characterization of the detector response and in its performance evaluation. The method used to evaluate its detection efficiency is reported, together with some preliminary results

XANES Study of Structural Disorder in Amorphous Silicon

An investigation of the structure of several amorphous silicon (a-Si) films is presented. Samples were prepared by using the ion beam sputtering technique at different substrate deposition temperatures. X-ray absorption spectroscopy and multiple scattering formalism have been used to detect structural variations of the a-Si films. The analysis of the XANES (X-ray absorption near-edge structure) spectra shows that increasing the substrate deposition temperature leads to a structural change toward a higher-level short-range order.

X-ray-absorption fine-structure study of ZnSexTe1−x alloys

X-ray-absorption fine-structure experiments at different temperatures in ZnSexTe1−x (x=0, 0.1, 0.2, 0.55, 0.81, 0.93, 0.99, and 1.0) have been performed in order to obtain information about the structural relaxation and disorder effects occurring in the alloys. First and second neighbor distance distributions have been characterized at the Se and Zn K edges, using multiple-edge and multiple-scattering data analysis. The first neighbor distance distribution was found to be bimodal. The static disorder associated with the Zn–Te distance variance did not depend appreciably on composition. On the other hand, the static disorder associated with the Zn–Se distance increased as the Se content diminished. Using the bonding angle information provided by our experiments the point of view of the anion has been related to that of the cation. The resulting structural model indicates that Zn tetrahedra surrounding the anions remain essentially undistorted, but forced to tilt from their ideal zincblende orientation to accommodate the minority element. The main origin of structural disorder is [email protected] ; [email protected]

Robots for Exploration, Digital Preservation and Visualization of Archeological Sites

Monitoring and conservation of archaeological sites are important activities necessary to prevent damage or to perform restoration on cultural heritage. Standard techniques, like mapping and digitizing, are typically used to document the status of such sites. While these task are normally accomplished manually by humans, this is not possible when dealing with hard-to-access areas. For example, due to the possibility of structural collapses, underground tunnels like catacombs are considered highly unstable environments. Moreover, they are full of radioactive gas radon that limits the presence of people only for few minutes. The progress recently made in the artificial intelligence and robotics field opened new possibilities for mobile robots to be used in locations where humans are not allowed to enter. The ROVINA project aims at developing autonomous mobile robots to make faster, cheaper and safer the monitoring of archaeological sites. ROVINA will be evaluated on the catacombs of Priscilla (in Rome) and S. Gennaro (in Naples)

Prognostic factors in Krukenberg tumor

BACKGROUND: Krukenberg tumor (KT) is a rare secondary ovarian tumor. Little is known about clinicopathologic factors affecting prognosis in KT. OBJECTIVE: To assess the prognostic value of clinicopathologic factors in KT through a systematic review and meta-analysis. METHODS: Electronic databases were searched from their inception to February 2019 for studies assessing the association of clinicopathologic factors with overall survival in KT. Pooled hazard ratio (HR) was calculated for each factor; a p value < 0.05 was considered significant. RESULTS: Twenty-three studies with 1743 patients were included. A decreased overall survival was significantly associated with peritoneal involvement (HR 1.944; p = 0.003), ascites (HR 2.055; p = 0.034), synchronous presentation (HR 1.679; p = 0.034) and increased serum CEA levels (HR 1.380; p = 0.010), but not with age > 50 (HR 0.946; p = 0.743), menopausal status (HR 1.565; p = 0.204), gastric origin (HR 1.600; p = 0.201), size > 5 cm (HR 1.292; p = 0.119), size > 10 cm (HR 0.925; p = 0.714), bilateral ovarian involvement (HR 1.113; p = 0.347), non-peritoneal extaovarian metastases (HR 1.648; p = 0.237), liver metastases (HR 1.118, p = 0.555), predominant signet ring cell morphology (HR 1.322; p = 0.208) and levels of CA125 (HR 0.933; p = 0.828) and CA19.9 (HR 0.996; p = 0.992). CONCLUSION: Peritoneal involvement, synchronous presentation, ascites and increased serum CEA levels appear as unfavorable prognostic factors in KT and might affect the patient management

Free electron laser-driven ultrafast rearrangement of the electronic structure in Ti

High-energy density extreme ultraviolet radiation delivered by the FERMI seeded free-electron laser has been used to create an exotic nonequilibrium state of matter in a titanium sample characterized by a highly excited electron subsystem at temperatures in excess of 10 eV and a cold solid-density ion lattice. The obtained transient state has been investigated through ultrafast absorption spectroscopy across the Ti M2,3-edge revealing a drastic rearrangement of the sample electronic structure around the Fermi level occurring on a time scale of about 100 fs

Pressure-induced amorphization and polyamorphism in one-dimensional single crystal TiO2 nanomaterials

The structural phase transitions of single crystal TiO2-B nanoribbons were investigated in-situ at high-pressure using the synchrotron X-ray diffraction and the Raman scattering. Our results have shown a pressure-induced amorphization (PIA) occurred in TiO2-B nanoribbons upon compression, resulting in a high density amorphous (HDA) form related to the baddeleyite structure. Upon decompression, the HDA form transforms to a low density amorphous (LDA) form while the samples still maintain their pristine nanoribbon shape. HRTEM imaging reveals that the LDA phase has an {\alpha}-PbO2 structure with short range order. We propose a homogeneous nucleation mechanism to explain the pressure-induced amorphous phase transitions in the TiO2-B nanoribbons. Our study demonstrates for the first time that PIA and polyamorphism occurred in the one-dimensional (1D) TiO2 nanomaterials and provides a new method for preparing 1D amorphous nanomaterials from crystalline nanomaterials.Comment: 4 figure

First measurement of the K−n →Λπ−non-resonant transition amplitude below threshold

We present the analysis of K−absorption processes on He4 leading to Λπ−final states, measured with the KLOE spectrometer at the DAΦNE e+e−collider and extract, for the first time, the modulus of the non-resonant K−n →Λπ−direct production amplitude about 33 MeV below the K‾N threshold. This analysis also allows to disentangle the K−nuclear absorption at-rest from the in-flight capture, for K−momenta of about 120 MeV. The data are interpreted with the help of a phenomenological model, and the modulus of the non-resonant K−n →Λπ−amplitude for K−absorption at-rest is found to be |AK−n→Λπ−|=(0.334±0.018stat−0.058+0.034syst)fm

SEISMIC MONITORING OF BUILDINGS WITH BASE ISOLATION

The seismic monitoring of buildings is important for two fundamental reasons: - evaluate the possible dynamic behavior of these structures during earthquakes; - gain experience on the general seismic behavior of the structures so that the experience and the database can be used in the future for design and analysis. The results of previous efforts in seismic monitoring of the structures have facilitated the devel-opment of a database, which in turn was used in the creation of new formulas and reference values for the estimation of the fundamental periods of the structures and the percentage of crit-ical damping from use during dynamic analyzes. The database is very well supplied with data on traditional buildings, but there is still not enough data for buildings isolated at the base. Some different structures with seismic base isolation have been monitored during recent strong earthquakes in Italy, namely Amatrice earthquake (2016/08/24, Mw=6.0) and Norcia earth-quake (2016/10/30, Mw=6.5). For the structure under examination, amplification phenomena have been noticed, up to about twice the accelerations on the superstructure, for very low energy value inputs. In these cases, however, it is noted that the amplified accelerations are extremely small, and very far from be-ing able to damage the structure. Records from the ENEA permanent accelerometric network, installed on the structure under examination, and the tests carried out on the same isolators used for the qualification tests of the devices mounted below the analyzed structure, permit to describe the behavior of the isolators in terms of force and displacement defining two non-linear laws, derived from experimental data

The KLOE-2 experiment at DAΦNE

KLOE-2 is the main experiment of the INFN Frascati National Laboratories and represents the continuation of KLOE. The previous apparatus, consisting in a huge Drift Chamber and an Electromagnetic Calorimeter, both immersed in a 0.5 T magnetic field, has been upgraded with new detectors to perform high-precision CPT symmetry and quantum coherence tests using neutral kaons, γγ-physics studies and searches of particles of hidden dark matter sectors. KLOE-2 started its data taking in November 2014 and is presently collecting data, achieving record performance in terms of peak luminosity and maximum daily integrated luminosity, which will allow to integrate more than 5fb−1 of data in the next 2 years