617 research outputs found
Legal aspects of marine science on climate change
Oceans and seas are key components in climate systems. The strong need for more specific knowledge and its systematic delivery and application, including in relation to climate effects on marine environment, led to the recent adoption of the the UN Decade of Ocean Science for Sustainable Development (2021-2030). From an international law of the sea perspective, the increasing marine scientific research activities and the use of novel technologies rise the question on the adequacy of the current applicable regulatory framework. This paper focuses on the main legal aspects of marine science on climate change and call for a paradigm-shift: from unilateralism to multilateralism in the interests of mankind
Generation of polarization entangled photon pairs by a single crystal interferometric source pumped by femtosecond laser pulses
Photon pairs, highly entangled in polarization have been generated under
femtosecond laser pulse excitation by a type I crystal source, operating in a
single arm interferometric scheme. The relevant effects of temporal walk-off
existing in these conditions between the ordinary and extraordinary photons
were experimentally investigated. By introducing a suitable temporal
compensation between the two orthogonal polarization components highly
entangled pulsed states were obtained
Hyperentanglement witness
A new criterium to detect the entanglement present in a {\it hyperentangled
state}, based on the evaluation of an entanglement witness, is presented. We
show how some witnesses recently introduced for graph states, measured by only
two local settings, can be used in this case. We also define a new witness
that improves the resistance to noise by increasing the number of local
measurements.Comment: 6 pages, 2 figures, RevTex. v2: new title, minor changes in the
explanation of the witness for hyperentangled states, more comments in the
conclusions sectio
Mobility and Legal Migration in the Context of the European Neighbourbood Policy: What Role for the European Union?
The paper examines the evolution of the external dimension of EU immigration policy mainly in the context of European Neighbourhood policy (ENP). The EU is interested in countering irregular migration from Southern neighbours rather than in facilitating legal migration for third country nationals. The latter field falls within the competence of the EU Member States and they are reluctant to open legal migration channels. Only recently Mobility Partnerships (MPs) have
been concluded with Morocco, Tunisia and Jordan. Most recently, the EU has decided to financially support countries of origin/transit in order to strengthen their capacity to tackle migration pressure; migration compacts will be negotiated
not only with Southern neighbours but also with other African countries. In contrast to Southern neighbours, MPs were agreed with all Eastern neighbours, except Belarus; readmission agreements and visa-free agreements were concluded
with three Eastern neighbour countries: Ukraine, Georgia and Moldova. The EU has fostered mobility and people-to-people movements in its relations with Eastern neighbours but the added value of EU legislation designed to favour legal migration
and integration of third country nationals remain limited. The conclusion is that the EU continues to be a «fortress», especially for low-skilled migrants seeking an employment
Regional seas
Description of developments in regional seas regulatory framewor
Generating qudits with d=3,4 encoded on two-photon states
We present an experimental method to engineer arbitrary pure states of qudits
with d=3,4 using linear optics and a single nonlinear crystal.Comment: 4 pages, 1 eps figure. Minor changes. The title has been changed for
publication on Physical Review
Probe lifetime around natural satellites with obliquity
The dynamics of a probe orbiting a moon can be significantly influenced by the noncoincidence
between the moon’s equatorial and orbital planes. Thus, we performed a
general analysis about the effects of the angle (obliquity) between the above-mentioned
planes and of the angle (nodal phasing) between the nodal lines of the mother planet’s
apparent orbit and the probe orbit on the lifetime of the probe. The lifetime, strictly
correlated to the variations in eccentricity of the probe orbit, was evaluated starting from
low values of the semi-major axis, moderate eccentricity, and high inclination to offer high
ground spatial resolution and extend latitudinal coverage of the natural satellite. This
investigation, carried out through numerical simulations, may be useful for identifying the
optimal initial conditions of the probe’s orbit elements, leading to an important increase
in the probe lifetime in missions devoted to the exploration of natural satellite
Experimental generation of complex noisy photonic entanglement
We present an experimental scheme based on spontaneous parametric
down-conversion to produce multiple photon pairs in maximally entangled
polarization states using an arrangement of two type-I nonlinear crystals. By
introducing correlated polarization noise in the paths of the generated photons
we prepare mixed entangled states whose properties illustrate fundamental
results obtained recently in quantum information theory, in particular those
concerning bound entanglement and privacy.Comment: 12 pages, 3 figure
Adhesion to zirconia: A systematic review of current conditioning methods and bonding materials
Background. Reliable bonding between resin composite cements and high strength ceramics is difficult to achieve because of their chemical inertness and lack of silica content that makes etching impossible. The purpose of this review is to classify and analyze the existing methods and materials suggested to improve the adhesion of zirconia to dental substrate by using composite resins, in order to explore current trends in surface conditioning methods with predictable results. Methods. The current literature, examining the bond strength of zirconia ceramics, and including in vitro studies, clinical studies, and a systematic review, was analyzed. The research in the literature was carried out using PubMed and Cochrane Library databases, only papers in English, published online from 2013 to 2018. The following keywords and their combinations were used: Zirconia, 3Y-TZP, Adhesion, Adhesive cementation, Bonding, Resin, Composite resin, Composite material, Dentin, Enamel. Results. Research, in PubMed and Cochrane Library databases, provided 390 titles with abstracts. From these, a total of 93 publications were chosen for analysis. After a full text evaluation, seven articles were discarded. Therefore, the final sample was 86, including in vitro, clinical studies, and one systematic review. Various adhesive techniques with different testing methods were examined. Conclusions. Airborne-particle abrasion and tribo-chemical silica coating are the pre-treatment methods with more evidence in the literature. Increased adhesion could be expected after physico-chemical conditioning of zirconia. Surface contamination has a negative effect on adhesion. There is no evidence to support a universal adhesion protocol
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