The effect of a nucleating agent on lamellar growth in melt-crystallizing polyethylene oxide

The effects of a (non co-crystallizing) nucleating agent on secondary nucleation rate and final lamellar thickness in isothermally melt-crystallizing polyethylene oxide are considered. SAXS reveals that lamellae formed in nucleated samples are thinner than in the pure samples crystallized at the same undercoolings. These results are in quantitative agreement with growth rate data obtained by calorimetry, and are interpreted as the effect of a local decrease of the basal surface tension, determined mainly by the nucleant molecules diffused out of the regions being about to crystallize. Quantitative agreement with a simple lattice model allows for some interpretation of the mechanism.Comment: submitted to Journal of Applied Physics (first version on 22 Apr 2002

Rotational sensitivity of the "G-Pisa" gyrolaser

G-Pisa is an experiment investigating the possibility to operate a high sensitivity laser gyroscope with area less than $1 \rm m^2$ for improving the performances of the mirrors suspensions of the gravitational wave antenna Virgo. The experimental set-up consists in a He-Ne ring laser with a 4 mirrors square cavity. The laser is pumped by an RF discharge where the RF oscillator includes the laser plasma in order to reach a better stability. The contrast of the Sagnac fringes is typically above 50% and a stable regime has been reached with the laser operating both single mode or multimode. The effect of hydrogen contamination on the laser was also checked. A low-frequency sensitivity, below $1 \rm Hz$, in the range of $10^{-8} \rm {(rad / s)/ \sqrt{Hz}}$ has been measured.Comment: 6 pages, 6 figures, presented at the EFTF-IFCS joint conference 200

Commentary: Novel interventions in complex aortic disease: A perfect storm to “B-SAFER”

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A comparison between methods of analytical continuation for bosonic functions

In this article we perform a critical assessment of different known methods for the analytical continuation of bosonic functions, namely the maximum entropy method, the non-negative least-square method, the non-negative Tikhonov method, the Pad\'e approximant method, and a stochastic sampling method. Three functions of different shape are investigated, corresponding to three physically relevant scenarios. They include a simple two-pole model function and two flavours of the non-interacting Hubbard model on a square lattice, i.e. a single-orbital metallic system and a two-orbitals insulating system. The effect of numerical noise in the input data on the analytical continuation is discussed in detail. Overall, the stochastic method by Mishchenko et al. [Phys. Rev. B \textbf{62}, 6317 (2000)] is shown to be the most reliable tool for input data whose numerical precision is not known. For high precision input data, this approach is slightly outperformed by the Pad\'e approximant method, which combines a good resolution power with a good numerical stability. Although none of the methods retrieves all features in the spectra in the presence of noise, our analysis provides a useful guideline for obtaining reliable information of the spectral function in cases of practical interest.Comment: 13 pages, 9 figure

Carbon nanotubes as target for directional detection of light WIMP

In this paper I will briefly introduce the idea of using Carbon Nanotubes (CNT) as target for the detection of low mass WIMPs with the additional information of directionality. I will also present the experimental efforts of developing a Time Projection Chamber with a CNT target inside and the results of a test beam at the Beam Test Facility of INFN-LNF.Comment: 3 figures, IFAE2017 poster session proceeding

Experimental Test of Two-way Quantum Key Distribution in Presence of Controlled Noise

We describe the experimental test of a quantum key distribution performed with a two-way protocol without using entanglement. An individual incoherent eavesdropping is simulated and induces a variable amount of noise on the communication channel. This allows a direct verification of the agreement between theory and practice.Comment: 4 pages, 3 figure

Antiradical activity of phenolic metabolites extracted from grapes of white and red Vitis vinifera L. cultivars

A diet rich in plant foods is strongly recommended for its beneficial effect on human health. In fact, plant secondary metabolites may exert various biological activities on mammalian cells. Among them, phenolics are excellent natural antioxidants able to rescue cell redox unbalance responsible for the onset of different pathologies. For these reasons, the present work was focused on the study of grape extracts obtained from eight different Italian Vitis vinifera cultivars, quite rare in Italian viticulture and not yet completely chemically characterized. For each preparation, total simple phenolic, flavonoidic and anthocyaninic content was measured through spectrophotometrical assays, while detailed biochemical profile was revealed by LC-MS analyses. In order to valorize the products of these varieties and increase our knowledge about their potential healthy role, the antioxidant power of the samples was evaluated by two different in vitro antiradical tests: DPPH and FRAP. Moreover, free radical scavenging properties of eleven grape pure compounds were investigated, with the aim to: a) compare their real antiradical property with the theoretical one; b) identify which one of them possessed the best bioactivity; c) understand how they might singularly contribute to the nutraceutical effect of the whole grapevine phytocomplex

Low Cost True Monofiber Optical Probe for Local Void Fraction Measurements in Minichannels

Two phase flow inside minichannels is one of the most investigated research topic at present. The measurement of the flow rate parameters is fundamental to characterize the flow pattern and its evolution over time. This paper shows that an optical technique, well-known for large diameter pipes, can be applied to mini channels with a laminar mass flow rate. In particular, a Y-junction mono-fiber optic system with a chamfered tip probe has been built and tested. This method is applied to the local void fraction measurement in a copper capillary pipe with internal diameter of 2 mm and external diameter of 3.00 mm. Different probes have been developed and tested. The accuracy of the method depends on the size, the shape of the tip and on the tip distance from the pipe centre. Different distances and liquid flow rate have been tested. The two-phase flow pattern is also visualized and recorded by a high speed camera (FASTEC Troubleshooter 16000 fps) and post processed with an image analysis technique. A good agreement between the optical and the video signal has been observed

MORPH: A Reference Architecture for Configuration and Behaviour Self-Adaptation

An architectural approach to self-adaptive systems involves runtime change of system configuration (i.e., the system's components, their bindings and operational parameters) and behaviour update (i.e., component orchestration). Thus, dynamic reconfiguration and discrete event control theory are at the heart of architectural adaptation. Although controlling configuration and behaviour at runtime has been discussed and applied to architectural adaptation, architectures for self-adaptive systems often compound these two aspects reducing the potential for adaptability. In this paper we propose a reference architecture that allows for coordinated yet transparent and independent adaptation of system configuration and behaviour