Theoretical Description of Two- and Three-Particle Interactions in Single Ionization of Helium by Ion Impact

In this work we calculate doubly differential cross sections (DDCS) for single ionization of helium by highly charged ion impact. We study the importance of two-particle interactions in these processes by considering the cross sections as a function of all two-particle subsystems momenta. Experimental DDCSs were obtained recently from kinematically complete experiments on single ionization of He by 100 MeV/amu C6+ and 3.6 MeV/amu Au24,53+ impact. Furthermore, we evaluated the importance of three-particle interactions by plotting the squared momenta of all three collision fragments simultaneously in a Dalitz plot. Using the first Born and distorted-wave approximations for fully differential cross sections, together with Monte Carlo integration techniques, we were able to reproduce the main features observed in experimental data and to assess the quality of the models implied by the different employed approximations

Teorethical studies of the stability of 8a-alkyll-1,2,3,4,6,8a- hexahydronaphtalen-1-ones using semiempirical methods

The Birch alkylation products are very unstable. We are showing, in this communication, the results of a theoretical study that compares different decomposition reaction mechanisms. The conclusions are in agreement with our experimental results.Facultad de Ciencias Exacta

Recycled PP for 3D Printing: Material and Processing Optimization through Design of Experiment

In this work, blends that were based on first use PP added with talc (PPt) and recycled polypropylene (r-PP) were designed and formulated, aiming at producing filaments that are suitable for 3D printing fused filament fabrication (FFF) processes. A preliminary characterization of PPt/r-PP blends at different weight ratios allowed selecting two systems showing adequate rheological behavior for FFF. The selected blends were melt compounded in a twin-screw extruder, optimizing the processing conditions through a design of experiments approach, involving the use of Taguchi's method. The materials that were prepared with the optimized processing conditions, hence showing the best performance in terms of rheological behavior and thermal characteristics, were then selected for the production of the filament and for the subsequent FFF processing. Finally, the morphology of the filament and the mechanical properties of 3D-printed samples were assessed, demonstrating the achievement of satisfactory results in terms of performances. In general, the obtained results clearly demonstrated that a proper optimization of both material and processing conditions offers the possibility of using recycled PP-based formulations for additive manufacturing processes, hence allowing a remarkable valorization of a low added-value material through its utilization for an innovative and sustainable manufacturing approach

The relativistic statistical theory and Kaniadakis entropy: an approach through a molecular chaos hypothesis

We have investigated the proof of the $H$ theorem within a manifestly covariant approach by considering the relativistic statistical theory developed in [G. Kaniadakis, Phy. Rev. E {\bf 66}, 056125, 2002; {\it ibid.} {\bf 72}, 036108, 2005]. As it happens in the nonrelativistic limit, the molecular chaos hypothesis is slightly extended within the Kaniadakis formalism. It is shown that the collisional equilibrium states (null entropy source term) are described by a $\kappa$ power law generalization of the exponential Juttner distribution, e.g., $f(x,p)\propto (\sqrt{1+ \kappa^2\theta^2}+\kappa\theta)^{1/\kappa}\equiv\exp_\kappa\theta$, with $\theta=\alpha(x)+\beta_\mu p^\mu$, where $\alpha(x)$ is a scalar, $\beta_\mu$ is a four-vector, and $p^\mu$ is the four-momentum. As a simple example, we calculate the relativistic $\kappa$ power law for a dilute charged gas under the action of an electromagnetic field $F^{\mu\nu}$. All standard results are readly recovered in the particular limit $\kappa\to 0$.Comment: 7 pages; to be published in EPJ

The HH-theorem in κ\kappa-statistics: influence on the molecular chaos hypothesis

We rediscuss recent derivations of kinetic equations based on the Kaniadakis' entropy concept. Our primary objective here is to derive a kinetical version of the second law of thermodynamycs in such a $\kappa$-framework. To this end, we assume a slight modification of the molecular chaos hypothesis. For the $H_{\kappa}$-theorem, it is shown that the collisional equilibrium states (null entropy source term) are described by a $\kappa$-power law extension of the exponential distribution and, as should be expected, all these results reduce to the standard one in the limit $\kappa\to 0$.Comment: 4 pages, eqs. (18) and (22) have been corrected, to appear in Phys. Lett.

Metamodels of a gas turbine powered marine propulsion system for simulation and diagnostic purposes

The paper presents the application of artificial neural network for simulation and diagnostic purposes applied to a gas turbine powered marine propulsion plant. A simulation code for the propulsion system, developed by the authors, has been extended to take into account components degradation or malfunctioning with the addition of performance reduction coefficients. The above coefficients become input variables to the analysis method and define the system status at a given operating point. The simulator is used to generate databases needed to perform a variable selection analysis and to tune response surfaces for both direct (simulation) and inverse (diagnostic) purposes. The application of the methodology to the propulsion system of an existing frigate version demonstrate the potential of the approach

Estimación de área foliar utilizando técnicas de procesamiento de imágenes: una metodología simple, fiable y de bajo costo

En este trabajo se propone una metodología para estimar área foliar (AF), basada en técnicas de procesamiento digital de imágenes usualmente utilizadas en teledetección. La metodología se evaluó para hojas de girasol. El AF y el ampliamente difundido índice de área foliar (IAF), calculado a partir del anterior, se requieren para modelar, validar y predecir un número importante de variables de interés en distintas áreas del conocimiento. Se analizan en este trabajo todas las etapas, desde la adquisición de las imágenes a los métodos de procesa-miento, así como la evaluación de la fiabilidad del método y, se diseñó, con especial detalle, una sección orientada a cuantificar adecuadamente la incertidumbre en la determinación del AF. El método propuesto es simple y robusto, las imágenes pueden adquirirse con cualquier cámara disponible y, para la estimación de superficie, pueden utilizarse una variedad de paquetes de software tanto comerciales como libres. La incerteza obtenida para la determinación del AF resultó inferior al 4% en la estimación de AF por planta. Cabe mencionar que todo el proceso se realiza a partir de las imágenes sin necesidad de datos del cultivo, climáticos, etc. Se proponen también alternativas semiautomáticas para la estimación de superficies que no presentan diferencias estadísticamente significativas con el diseño original.Sociedad Argentina de Informática e Investigación Operativ

Caractérisation variétale de cépages musqués à raisin coloré au moyen de paramètres ampélographiques descriptifs et biochimiques

Vingt-deux cépages à saveur musquée à baie colorée cultivés dans une collection au Piédmont (Nord Quest d'Italie) ont été étudiés d'un point de vue ampélographique et biochimique. Des observations descriptives ont été effectuées sur les souches ainsi que l'analyse des terpénols libres et glycosylés du jus et des polyphénols de la pellicule des baies à maturité. Les données analytiques et ampélographiques ont été soumises à l'analyse statistique multidimensionelle (analyse des clusters et analyse des composantes principales).Les résultats obtenus ont permis de bien caractériser les 22 cépages examinés. Les observations déscriptives ont indiqué que certains cépages pouvaient être groupés selon leur profil morphologique (groupes de "Muscat à petits grains", de "Hambourg", etc.). L'analyse quali-quantitative des anthocyanidols et des esters hydroxycinnamoyltartriques du raisin a permis de former des groupes de cépages, différents aussi pour la couleur de la baie qui allait du rose clair, au rose foncé, au rouge, au violet et au bleunoir. De rélations entre des poliphenols de la pellicule et des composés terpeniques du jus, en plus, ont été mise en évidence: onl a observé par example que les raisins ou la cyanidine monoglucoside était l'anthocyanidol prédominant (couleur de la baie rose très claire) avaient le jus le plus riche en linalol.Morphological and biochemical characterisation of coloured berry-muscat grapevine cultivarsTwenty-two grapevine cultivars with muscat flavour and coloured berries grown in a collection vineyard in Piedmont (Northwest Italy) have been investigated by ampelographic and biochemical methods. Morphological and ampelographic observations have been carried out on the vines. Free and bound terpenes of the juice and berry skin phenolic compounds at maturity have also been analysed. The data were processed by multivariate statistical procedures (cluster and principal component analysis). The results allowed the successful characterisation of the cultivars. The ampelographic descriptive observations indicated that the cultivars could be grouped according to their morphological characteristics, viz. as similar to ''Muscat a petits grains'' or similar to ''Muscat of Hamburg'' etc.). Furthermore, the determination of berry skin anthocyanins together with hydroxycinnamoyl tartaric acids allowed to group according to the berry skin colour which varied from light rose to dark rose, red, violet and blue-black. Some juice terpenes showed relationships with some berry polyphenols: the cultivars richest in cyanidin (skin of light pink colour) were also the richest in linalool