945 research outputs found

    LEMONGRASS PLANT LEAF AND CULM AS POTENTIAL SOURCES OF REINFORCEMENT FOR BIO-COMPOSITES

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    A possible source of natural reinforcement for bio-composites can be represented by lemongrass plant (Cymbopogon flexuosus), a clumped and perennial grass which belongs to the Poaceae family. This plant is extensively used for several applications such as pharmacology, food preservation and cosmetics but, to the best of our knowledge, few papers were published on its use as source for reinforcement of composites and no one article was focused on the comparison between lemongrass leaves and culms as potential source of natural reinforcement. To this aim, a preliminary investigation on leaf and culm fibers was carried out to compare their physical and chemical features as well as their tensile properties. Furthermore, bio-composites based on a biodegradable starch-derived matrix (MaterBi®) and lemongrass leaf and culm particles were manufactured via extrusion and compression molding. For both fillers, two compositions (i.e., 10% and 20 wt.%) were investigated in terms of morphological and mechanical properties

    Giants on Deformed Backgrounds Part II: The Gauge Field Fluctuations

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    We study the full bosonic spectrum around giant and dual giant graviton probes in exactly marginally deformed backgrounds. Considering supersymmetric and non-supersymmetric three-parameter deformations of AdS_5 X S^5, we perform a detailed analysis of small fluctuations for both the expanded D3-brane configurations. In particular, we enhance the scalar spectra of frequencies found in our previous paper hep-th/0609173 with the important contributions brought by the gauge field fluctuations. The giant graviton case exhibits a non-trivial coupling between scalar and vector modes driven by the deformation, whose resolution yields to a universal correction of the undeformed spectrum. On the other hand, dual giant vibrations turn out to be completely decoupled. From our results one can also easily read the gauge field fluctuations in the undeformed (dual) giant graviton scenario.Comment: LaTex, 20 pages, 3 figures, uses JHEP

    Convolutional architectures for virtual screening

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    Background: A Virtual Screening algorithm has to adapt to the different stages of this process. Early screening needs to ensure that all bioactive compounds are ranked in the first positions despite of the number of false positives, while a second screening round is aimed at increasing the prediction accuracy. Results: A novel CNN architecture is presented to this aim, which predicts bioactivity of candidate compounds on CDK1 using a combination of molecular fingerprints as their vector representation, and has been trained suitably to achieve good results as regards both enrichment factor and accuracy in different screening modes (98.55% accuracy in active-only selection, and 98.88% in high precision discrimination). Conclusion: The proposed architecture outperforms state-of-the-art ML approaches, and some interesting insights on molecular fingerprints are devised

    Beta, Dipole and Noncommutative Deformations of M-theory Backgrounds with One or More Parameters

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    We construct new M-theory solutions starting from those that contain 5 U(1) isometries. We do this by reducing along one of the 5-torus directions, then T-dualizing via the action of an O(4,4) matrix and lifting back to 11-dimensions. The particular T-duality transformation is a sequence of O(2,2) transformations embedded in O(4,4), where the action of each O(2,2) gives a Lunin-Maldacena deformation in 10-dimensions. We find general formulas for the metric and 4-form field of single and multiparameter deformed solutions, when the 4-form of the initial 11-dimensional background has at most one leg along the 5-torus. All the deformation terms in the new solutions are given in terms of subdeterminants of a 5x5 matrix, which represents the metric on the 5-torus. We apply these results to several M-theory backgrounds of the type AdS_r x X^{11-r}. By appropriate choices of the T-duality and reduction directions we obtain analogues of beta, dipole and noncommutative deformations. We also provide formulas for backgrounds with only 3 or 4 U(1) isometries and study a case, for which our assumption for the 4-form field is violated.Comment: v2:minor corrections, v3:small improvements, v4:conclusions expanded, to appear in Class. Quant. Gra

    A KK-monopole giant graviton in AdS_5 x Y_5

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    We construct a new giant graviton solution in AdS_5 x Y_5, with Y_5 a quasi-regular Sasaki-Einstein manifold, consisting on a Kaluza-Klein monopole wrapped around the Y_5 and with its Taub-NUT direction in AdS_5. We find that this configuration has minimal energy when put in the centre of AdS_5, where it behaves as a massless particle. When we take Y_5 to be S^5, we provide a microscopical description in terms of multiple gravitational waves expanding into the fuzzy S^5 defined as an S^1 bundle over the fuzzy CP^2. Finally we provide a possible field theory dual interpretation of the construction.Comment: 11 pages, published versio

    Burnout syndrome in reception systems for illegal immigrants in the Mediterranean. A quantitative and qualitative study of Italian practitioners

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    Illegal immigration throughout the Mediterranean Sea is an intense and epoch-making phenomenon. This quantitative and qualitative study, based on the framework of the JD-R Model of burnout, described and assessed the risk of burnout among practitioners working in the reception system for illegal immigrants. A sample of Italian practitioners completed the Link Burnout Questionnaire (N = 193) and a semistructured interview (N = 108). The analysis of the questionnaires was carried out via ANOVA and χ2 test. The content of the interviews was examined using T-LAB. Quantitative results showed that the sample was generally at risk of burnout, and about a quarter were at severe risk. Qualitative results highlighted aspects of burnout that are specific to this working context: large workload, mental fatigue, and lack of social support; inability to understand the language and cultural differences of the immigrants; having to deal with organisational problems that come up repeatedly. This study offers coping strategies that can improve organisational health and performance of practitioners working in illegal immigration. Italy's shape, geographical location, and geo-political role make it a case in point for the whole European continent regarding the sustainability of illegal immigration across the Mediterranean Sea

    Alpha-particle clustering in excited expanding self-conjugate nuclei

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    The fragmentation of quasi-projectiles from the nuclear reaction 40Ca + 12C at 25 MeV/nucleon was used to produce alpha-emission sources. From a careful selection of these sources provided by a complete detection and from comparisons with models of sequential and simultaneous decays, strong indications in favour of α\alpha-particle clustering in excited 16O, 20Ne and 24}Mg are reported.Comment: 8 pages, 4 figures, 12th International Conference on Nucleus-Nucleus collisions (NN2015), 21-26 June 2015, Catania, Ital
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