Nonresonant Raman spectrum of C60 nanopeapod: C60 polymerization effects

We present a force constants model for the vibrational modes in C60 dimer and polymer phases. The results of this model are used to calculate the nonresonant Raman spectra of infinitely long isolated C60 dimer and polymer peapod in the framework of bond-polarization theory by using the spectral moment’s method. The changes of the Raman spectrum in terms of the structure of the C60 molecules inside the nanotubes are identified. We show that the lowest Raman frequency region of the nanotube is more affected by the C60 chain insertion in comparison with the higher one.We present a force constants model for the vibrational modes in C60 dimer and polymer phases. The results of this model are used to calculate the nonresonant Raman spectra of infinitely long isolated C60 dimer and polymer peapod in the framework of bond-polarization theory by using the spectral moment’s method. The changes of the Raman spectrum in terms of the structure of the C60 molecules inside the nanotubes are identified. We show that the lowest Raman frequency region of the nanotube is more affected by the C60 chain insertion in comparison with the higher one

Raman-Active modes in Homogeneous and Inhomogeneous Bundle of Single-Walled Carbon Nanotubes

In the present work, the non-resonant Raman active modes were calculated for several diameters, chiralities and sizes for homogeneous and inhomogeneous bundles of single-walled carbon nanotubes (BSWCNT's), using the spectral moment’s method (SMM). Additional intense Raman active modes are present in the breathing-like modes (BLM) spectra of these systems in comparison with a single fully symmetric A1g mode characteristic of isolated nanotubes (SWCNT's). The dependence of the frequency of these modes in terms of diameters, lengths and number of tubes is investigated. We find that for finite bundle, additional breathing-like modes (BLM's) appear as a specific signature. Finally, the effects of the inhomogeneous bundles on the Raman spectra were studied.In the present work, the non-resonant Raman active modes were calculated for several diameters, chiralities and sizes for homogeneous and inhomogeneous bundles of single-walled carbon nanotubes (BSWCNT's), using the spectral moment’s method (SMM). Additional intense Raman active modes are present in the breathing-like modes (BLM) spectra of these systems in comparison with a single fully symmetric A1g mode characteristic of isolated nanotubes (SWCNT's). The dependence of the frequency of these modes in terms of diameters, lengths and number of tubes is investigated. We find that for finite bundle, additional breathing-like modes (BLM's) appear as a specific signature. Finally, the effects of the inhomogeneous bundles on the Raman spectra were studied

Cluster analysis by order statistics

The problem of unsupervised pattern classification can be tackled by detecting the modes of the underlying probability density function of the data . In this paper, we show how the modes can be detected by adaptive transformations based on order statistics . Finally, experimental results are presented to show the robustness of these transformations .Le problème de la classification automatique non supervisée peut être abordé en détectant les modes de la fonction de densité de probabilité sous-jacente à la distribution des observations disponibles. Dans cet article, on montre comment ces modes peuvent être mis en évidence par des transformations adaptatives basées sur les statistiques d'ordre. Des résultats expérimentaux sont présentés en dernier lieu pour montrer la robustesse de ces transformations de statistiques d'ordre

Size And Chirality Effects On Raman Spectrum Of Double-Wall Carbon Nanotube Bundle

We study the tube size and bundling effects on Raman active breathing-like phonon modes (BLM) and tangential-like phonon mode (TLM) of double-walled carbon nanotubes (DWCNT) in the framework of the bond polarization theory, and use the spectral moment’s method. The Raman active modes are calculated for different diameter and chirality of the inner and outer DWCNT tubes. The dependence of the Raman spectrum of bundles of identical DWCNTs as a function of the size of the bundle is analysed and additional breathing-like modes are predicted in DWCNT bundle of finite size.We study the tube size and bundling effects on Raman active breathing-like phonon modes (BLM) and tangential-like phonon mode (TLM) of double-walled carbon nanotubes (DWCNT) in the framework of the bond polarization theory, and use the spectral moment’s method. The Raman active modes are calculated for different diameter and chirality of the inner and outer DWCNT tubes. The dependence of the Raman spectrum of bundles of identical DWCNTs as a function of the size of the bundle is analysed and additional breathing-like modes are predicted in DWCNT bundle of finite size

Modelling and simulation of vibrationnal properties of carbon nanotubes and derivatives

The aim of the present paper is to identify the main Raman vibrational features of carbon nanotubes and derivatives. In this goal, Raman active mode calculations have been performed on different single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) as well as peapods. The comparison between the calculations performed on these different systems allows us to identify the Raman-active modes of each carbon nanomaterials. In SWCNTs, the tangential modes are located around 1590 cm-1 and the radial breathing mode follows A/D law. This latter law is modified in bundle of SWCNTs, DWCNTs or peapods.The aim of the present paper is to identify the main Raman vibrational features of carbon nanotubes and derivatives. In this goal, Raman active mode calculations have been performed on different single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) as well as peapods. The comparison between the calculations performed on these different systems allows us to identify the Raman-active modes of each carbon nanomaterials. In SWCNTs, the tangential modes are located around 1590 cm-1 and the radial breathing mode follows A/D law. This latter law is modified in bundle of SWCNTs, DWCNTs or peapods

Raman active modes in single-walled boron nitride nanotube bundles

We use the spectral moments method in the framework of the bond-polarization theory to calculate polarized nonresonant Raman spectra of chiral and achiral bundles of single walled boron nitride nanotubes (BWBNNTs) as a function of their diameter and chirality. The Spectra are computed for infinite size of BWBNNTs. We used a Lennard-Jones potential to describe the van der waals intertube interactions between tubes in a bundle. We show that the Raman active modes in the low wave number region are very sensitive to the nanotube diameter. We found that for infinite nanotube bundles, additional Radial Breathing Like mode appears in the low wave number region. These results are useful to interpret the experimental Raman spectra of BWBNNTs

Finite size effects on Raman spectrum of single-walled boron nitride nanotube

Using the spectral moments method, we present calculations of Raman active modes of Single Walled Boron Nitride Nanotube (SW-BNNT). The Spectra are computed for chiral and achiral nanotubes in terms of their diameter and length. The behaviors of low frequency Raman active modes characteristic, in terms of the tube diameter revealed that these frequencies are diameter dependent. We show that the number of Raman active modes, their frequencies, and intensities depend on the length and chirality of the nanotubes. These predictions are useful to interpret the experimental Raman spectra of BNNTs.Using the spectral moments method, we present calculations of Raman active modes of Single Walled Boron Nitride Nanotube (SW-BNNT). The Spectra are computed for chiral and achiral nanotubes in terms of their diameter and length. The behaviors of low frequency Raman active modes characteristic, in terms of the tube diameter revealed that these frequencies are diameter dependent. We show that the number of Raman active modes, their frequencies, and intensities depend on the length and chirality of the nanotubes. These predictions are useful to interpret the experimental Raman spectra of BNNTs

Dataset Construction and Analysis of Screenshot Malware

Among the various types of spyware, screenloggers are distinguished by their ability to capture screenshots. This gives them considerable nuisance capacity, giving rise to theft of sensitive data or, failing that, to serious invasions of the privacy of users. Several examples of attacks relying on this screen capture feature have been documented in recent years. However, there is not sufficient empirical and experimental evidence on this topic. Indeed, to the best of our knowledge, there is no dataset dedicated to screenshot-taking malware until today. The lack of datasets or common testbed platforms makes it difficult to analyse and study their behaviour in order to develop effective countermeasures. The screenshot feature is often a smart feature that does not activate automatically once the malware has infected the machine; the activation mechanisms of this function are often more complex. Consequently, a dataset which is completely dedicated to them would make it possible to better understand the subtleties of triggering screenshots and even to learn to distinguish them from the legitimate applications widely present on devices. The main purpose of this paper is to build such a dataset and analyse the behaviour of screenloggers

Volvulus du grêle sur mésentère commun incomplet une redoutable complication rare chez l’adulte: à propos de 1 cas

Le mésentère commun résulte d'une anomalie de rotation du tube digestif. Il est caractérisé par la persistance d'une disposition anatomique embryonnaire secondaire à une anomalie de rotation de l'anse ombilicale primitive, constituant ainsi un méso commun à toute l'anse intestinale etune racine du mésentère extrêmement courte. Cette insuffisance de rotation est le plus souvent associée à un défaut d'accolement. Ces  anomalies de rotation intestinale peuvent aboutir à des complications redoutables parfois mortelles, qui surviennent généralement au cours de la période néonatale où à l'âge pédiatrique. On estime que la prévalence de ces malformations congénitales à l'âge adulte est de l'ordre de 0,2% à 0,5% âge auquel elles demeurent très souvent asymptomatiques et donc non diagnostiquées. Le diagnostic de volvulus total du grêle peut se faire dans des circonstances très variées: en urgence devant un tableau  d'occlusion intestinale aiguë, voire un état de choc pouvant conduire au décès, devant un tableau de douleurs abdominales répétées plus ou moins associées à des troubles du transit. Nous rapportons l'observation d'un patient de 18 ans admis pour volvulus total du grêle sur mésentère commun incomplet chez qui l'évolution était favorable

Rapid determination of HLA B*07 ligands from the West Nile virus NY99 genome.

Defined T cell epitopes for West Nile (WN) virus may be useful for developing subunit vaccines against WN virus infection and diagnostic reagents to detect WN virus-specific immune response. We applied a bioinformatics (EpiMatrix) approach to search the WN virus NY99 genome for HLA B*07 restricted cytotoxic T cell (CTL) epitopes. Ninety-five of 3,433 WN virus peptides scored above a predetermined cutoff, suggesting that these would be likely to bind to HLA B*07 and would also be likely candidate CTL epitopes. Compared with other methods for genome mapping, derivation of these ligands was rapid and inexpensive. Major histocompatibility complex ligands identified by this method may be used to screen T cells from WN virus-exposed persons for cell-mediated response to WN virus or to develop diagnostic reagents for immunopathogenesis studies and epidemiologic surveillance