A unification in the theory of linearization of second order nonlinear ordinary differential equations

In this letter, we introduce a new generalized linearizing transformation (GLT) for second order nonlinear ordinary differential equations (SNODEs). The well known invertible point (IPT) and non-point transformations (NPT) can be derived as sub-cases of the GLT. A wider class of nonlinear ODEs that cannot be linearized through NPT and IPT can be linearized by this GLT. We also illustrate how to construct GLTs and to identify the form of the linearizable equations and propose a procedure to derive the general solution from this GLT for the SNODEs. We demonstrate the theory with two examples which are of contemporary interest.Comment: 8 page

Radiolysis of ammonia-containing ices by energetic, heavy and highly charged ions inside dense astrophysical environments

Deeply inside dense molecular clouds and protostellar disks, the interstellar ices are protected from stellar energetic UV photons. However, X-rays and energetic cosmic rays can penetrate inside these regions triggering chemical reactions, molecular dissociation and evaporation processes. We present experimental studies on the interaction of heavy, highly charged and energetic ions (46 MeV Ni^13+) with ammonia-containing ices in an attempt to simulate the physical chemistry induced by heavy ion cosmic rays inside dense astrophysical environments. The measurements were performed inside a high vacuum chamber coupled to the heavy ion accelerator GANIL (Grand Accelerateur National d'Ions Lourds) in Caen, France.\textit{In-situ} analysis is performed by a Fourier transform infrared spectrometer (FTIR) at different fluences. The averaged values for the dissociation cross section of water, ammonia and carbon monoxide due to heavy cosmic ray ion analogs are ~2x10^{-13}, 1.4x10^{-13} and 1.9x10^{-13} cm$^2$, respectively. In the presence of a typical heavy cosmic ray field, the estimated half life for the studied species is 2-3x10^6 years. The ice compaction (micropore collapse) due to heavy cosmic rays seems to be at least 3 orders of magnitude higher than the one promoted by (0.8 MeV) protons . In the case of the irradiated H2O:NH3:CO ice, the infrared spectrum at room temperature reveals five bands that were tentatively assigned to vibration modes of the zwitterionic glycine (+NH3CH2COO-).Comment: Accepted to be published in Astronomy and Astrophysics; Number of pages: 12; Number of Figures: 7; Number of Tables:

Secure and trustworthy file sharing over cloud storage using eID tokens

This paper presents a multi-platform, open-source application that aims to protect data stored and shared in existing cloud storage services. The access to the cryptographic material used to protect data is implemented using the identification and authentication functionalities of national electronic identity (eID) tokens. All peer to peer dialogs to exchange cryptographic material is implemented using the cloud storage facilities. Furthermore, we have included a set of mechanisms to prevent files from being permanently lost or damaged due to concurrent modification, deletion and malicious tampering. We have implemented a prototype in Java that is agnostic relatively to cloud storage providers; it only manages local folders, one of them being the local image of a cloud folder. We have successfully tested our prototype in Windows, Mac OS X and Linux, with Dropbox, OneDrive, Google Drive and SugarSync

VOLCANICLASTIC DEPOSITION AND MIGRATION OF BASIN DEPOCENTRES AFTER THE ERUPTION OF THE NEAPOLITAN YELLOW TUFF: THE POZZUOLY BAY (NAPLES, ITALY)

The Campi Flegrei is an active caldera located on the coastal zone of SW Italy (Fig. 1), close to the town of Naples Bay, that has been characterized by explosive activity and unrest throughout the Late Quaternary. This area represents a very active segment of the Eastern Tyrrhenian margin and may be regarded as an ideal laboratory to understand the mechanisms of caldera dynamics and the interplay between volcanism, tectonics and sedimentary processes along a continental back-arc margin. Recent research at Campi Flegrei has shown that a significant part of the offshore volcaniclastic products and structures, the late-stage geodynamic evolution of the inner caldera resurgence and the stratal geometry of the caldera fill are still poorly known. Particularly, highresolution seismic data highlight the presence of an intra-caldera resurgent dome in the inner sector of the Pozzuoli bay that underwent significant uplift/subsidence after the eruption of the NYT (Sacchi et al., this volume). In this study we integrate geophysical data of different resolution/penetration obtained from high-resolution reflection seismic profiles (Chirp and Sparker sources) partly calibrated by gravity core in order to provide a 3D depositional model of density flows and migration of basin depocentres for the Pozzuoli Bay after the eruption of the NYT. The new data document the occurrence of two distinct layers of resediments, mostly represented by density flow deposits, separated by an interval of hemipelagic sediments. The two density flow units display a remarkable difference in their thickness and internal geometry. Across the bay, the lower unit is ca 5m thick in the western sector and reaches its maximum of ca 10 m in the central sector while it is absent towards the east. The upper unit, on the contrary, displays the minimum thickness of 10m close to the central sector of the bay and increases up to ca 16 and 12m in the western and eastern sector of the bay, respectively. The variation in thickness of the density flow deposits appears to be related with the amount of sediments available. The upper density flow deposits is also internally more chaotic respect to the lower one, suggesting higher energy and/or turbulence (Fig. 2). Sections and isopach maps clearly illustrate that the basin depocentre topography is not fixed at one position but migrates southwards in time (Fig. 3). Based on the above observations, we suggest that the uplift of the resurgent dome and subsidence of the southern sector, occurred after the eruption of the Neapolitan Yellow Tuff, acted as a major control in the increase of the sea-floor gradient in the Pozzuoli bay. This may have triggered in turn, the deposition of gravity flow deposits along with a progressive migration of basin depocentres through time

Improving the Knowledge on Seismogenic Sources in the Lower Tagus Valley for Seismic Hazard Purposes

The Lower Tagus Valley, that includes the metropolitan area of Lisbon, has been struck by several earthquakes which produced significant material damage and loss of lives. Their exact location remains unknown. Our goal is to shed some light into the seismogenic sources in the area using seismic reflection and geological data. In areas with no seismic coverage, potential-field data interpretation was carried out. Seismicity was overlaid to the potential seismogenic structures and high-resolution data was acquired in order to confirm which structures have been active into the Quaternary. Three major fault-zones affecting the Neogene were identified: V. F. Xira, Samora-Alcochete and Pinhal Novo. For the first fault, strong evidences suggest it is active. The other two fault-zones and other structures previously unknown can be correlated with several epicentres. Empirical relationships between maximum moment magnitude and fault area indicate that MW > 6.5 earthquakes can be expected for the larger structures

The role of the nature of the noise in the thermal conductance of mechanical systems

Focussing on a paradigmatic small system consisting of two coupled damped oscillators, we survey the role of the L\'evy-It\^o nature of the noise in the thermal conductance. For white noises, we prove that the L\'evy-It\^o composition (Lebesgue measure) of the noise is irrelevant for the thermal conductance of a non-equilibrium linearly coupled chain, which signals the independence between mechanical and thermodynamical properties. On the other hand, for the non-linearly coupled case, the two types of properties mix and the explicit definition of the noise plays a central role.Comment: 9 pages, 2 figures. To be published in Physical Review

Electrical and thermal properties of polyurethane/carbon nanotubes composites

The aim of this work was to study the effect of dispersing small amounts of CNT on the thermal diffusivity and electrical resistivity of PU/CNT composites. The PU nanocomposites were prepared with 0.5% and 1% weight of CNT. The composites were prepared by dispersion of the CNT in poly(propylene glycol) (PPG) followed by in situ polymerization, by mixing with 4,4′-Methylene di-p-phenyl diisocyanate (MDI). The PPG was characterized by an average molecular weight of 425 g/mol and a hydroxyl value 250 to 276 mg KOH/g. The MDI was characterized by a isocianate value (%NCO value) of 27.9-29.2. It was observed that the thermal diffusivity slightly increased with the addition of the CNT, but the results obtained were within the typical range for polymers (in the order of 10-8 m2/s). The electrical resistivity measured for the composites showed a large decrease after the addition of 0.5% and 1% of CNT. The electrical resistivity decreased 3 and 7 decades (from 109 .m to 106 and 103 .m) for 0.5 and 1% CNT composites, respectively. Thus, the composite bearing 1% of CNT dispersed in the PU presented semiconductor behaviour

Área de vida do veado-catingueiro (mazama gouazoubira; Fisher, 1814) no Pantanal da Nhecolândia-MS.

O gênero é Mazama possui dez espécies reconhecidas, sendo o mais diverso entre os cervídeos neotropicais. As características ecológicas deste grupo, adaptado para ambientes florestais fechados, constituem a principal razão pela qual a história natural do gênero é pouco estudada (Barrette, 1987). Como consequência dessa escassez, considera-se que 3 espécies do gênero possuam dados insuficientes, porém as outras cinco já estão enquadradas em alguma categoria de ameaça (IUCN, 2012). Na literatura, o total de animais do gênero monitorados por telemetria era de 15 indivíduos (13 M. gouazoubira e 2 M. americana), sendo 7 deles translocados (Ramos et al., 2010; Black-Décima et al., 2010). Nesse contexto, desenvolver metodologias para captura e obtenção de dados ecológicos de Mazamas é fundamental para qualquer ação de manejo envolvendo o grupo. O veado-catingueiro (M. gouazobira) no pantanal surge como uma espécie/situação modelo interessante, uma vez que a captura nessa região é mais acessível e o ambiente heterogêneo da região se mostra interessante para obtenção de dados inéditos sobre uso espaço e seleção de habitat por essa intrigante espécie, que tem se mostrado resiliente frente às alterações antrópicas na paisagem