Determination of low molecular weight volatiles in Ficus carica using HS-SPME and GC/FID

Ficus carica L. is one of the earliest cultivated fruit trees, having an important consumption in Mediterranean countries. In this work, the volatile compound profiles of two characteristic Portuguese white varieties (‘‘Pingo de Mel” and ‘‘Branca Tradicional”) was determined by HS-SPME and GC/FID. Leaves, pulps and peels, submitted to freezing and lyophilisation treatments, were analysed. The two varieties presented a similar profile composed of eight volatile compounds: acetaldehyde, ethyl acetate, methanol, ethanol, hexanal, limonene, (E)-2-hexenal and octanal. The total volatile content was different among the vegetal materials, following the order leaves > peels > pulps. Methanol and ethanol are the major compounds in all samples. The developed procedure revealed to be rapid, sensitive, reproducible and accurate. The detection limit values were low, and the method precise. The recovery values for acetaldehyde, ethyl acetate, methanol and ethanol were generally high, suggesting that it will be most suitable for compounds with low molecular weight. Due to its rapidity and low cost, this technique can be useful in the quality control of fig fruit and leaves

Railway infrastructure asset management: the whole-system life cost analysis

Delivering the railway infrastructure whose functionality is sustainable and uncompromised in terms of safety and availability under ever decreasing budget constraints is a great challenge. The successful accomplishment of this task relies on the effective management of individual assets within a wider whole system perspective. This is a highly complex decision-making task where mathematical models are required to enable well-informed choices. In this study, a novel modelling framework is proposed for performing the whole system lifecycle cost analysis. The framework is based on two models: railway network performance and costs. Using the former model investigations of the effects of decisions can be carried out for the individual asset and the whole system. A Petri net modelling technique is used to construct the model. A form of Monte Carlo simulation is then used to obtain model results. The infrastructure performance model is then integrated with the cost model to perform the lifecycle cost analysis. A superstructure example is presented to demonstrate the application of the approach. The results show that taking into account interdependencies among the intervention activities greatly influences, not only the performance of the infrastructure, but also its lifecycle costs and thus should be included in the cost analysis

Dynamic Scaling in Diluted Systems Phase Transitions: Deactivation trough Thermal Dilution

Activated scaling is confirmed to hold in transverse field induced phase transitions of randomly diluted Ising systems. Quantum Monte Carlo calculations have been made not just at the percolation threshold but well bellow and above it including the Griffiths-McCoy phase. A novel deactivation phenomena in the Griffiths-McCoy phase is observed using a thermal (in contrast to random) dilution of the system.Comment: 4 pages, 4 figures, RevTe

Dual role of copper on the reactivity of activated carbons from coal and lignocellulosic precursors

The synthesis of copper-doped activated carbons from different origin (i.e., lignocellulosic and bituminous coal) by a wet impregnation and low temperature calcination procedure has been explored, as well as the role of copper particles on the physicochemical and structural features of the resulting materials. The textural characterization and isothermal reactivity analysis of the pristine and doped activated carbons have shown that the role of copper during the calcination step strongly depended on the nature of the carbon matrix. Copper impregnation of a coal-derived activated carbon catalyzed the air gasification of the material at a very low temperature (i.e., 325 °C), bringing about the development of microporosity on the doped carbon. In contrast, when copper was immobilized on a lignocellulose-derived activated carbon, the metallic species act as combustion retardant during the calcination step, protecting the carbon matrix during the catalytic gasification. In both cases, the resulting materials displayed a homogenous distribution of copper within the carbon matrix, while preserving large textural properties.The authors thank the Spanish MICINN for financial support (projects CTM2008-01956/TECNO and Acción Integrada AIB2010PT-00209). MH thanks CSIC for a postdoctoral contract. MA thanks FCT for her PhD fellowship (SFRH/BD/71673/2010). The authors also thank Cordex for kindly providing the sisal residues.Peer reviewe

New features of quantum discord uncovered by q-entropies

The notion of quantum discord introduced by Ollivier and Zurek [Phys. Rev. Lett 88, 017901 (2001)] (see also Henderson and Vedral [J. Phys. A 34, 6899 (2001)]) has attracted increasing attention, in recent years, as an entropic quantifier of non-classical features pertaining to the correlations exhibited by bipartite quantum systems. Here we generalize the notion so as to encompass power-law q-entropies (that reduce to the standard Shannon entropy in the limit $q \to 1$) and study the concomitant consequences. The ensuing, new discord-like measures we advance describe aspects of non-classicality that are different from those associated with the standard quantum discord. A particular manifestation of this difference concerns a feature related to order. Let $D_1$ stand for the standard, Shannon-based discord measure and $D_q$ for the $q \ne 1$ one. If two quantum states $A$, $B$ are such that $D_1(A) > D_1(B)$, this order-relation does not remain invariant under a change from $D_1$ to $D_q$.Comment: 11 pages, 8 figure

Дискусійні питання історії ЗУНР

У статті аналізуються питання, які все ще залишаються в історіографії Західноукраїнської Народної Республіки. Автор звертає увагу на контроверсійні точки зору щодо революційних подій, які відбулися 1 листопада 1918 р. у Львові, стосовно часу існування ЗУНР, Акту злуки УНР та ЗУНР, причин поразки Української Галицької армії тощо.The author of the article analyses the questions that are still disputable in modern Ukrainian historiography. The author attracts our attention to the controversial points of view concerning the type of revolutionary events which took place on the 1 st of November 1918 in Lviv, concerning the time of WUPR existence, concerning the Act of Unification of Western Ukrainian People’s Republic end Ukrainian People’s Republic , concerning the reasons of the defeat of Ukrainian army, etc

Changes in fatty acid biosynthesis in marine microalgae as a response to medium nutrient availability

To maximize and enhance the fatty acid (FA) profiles of microalgae, it is crucial to understand the metabolic path ways that lead to high levels of the desired product. Nannochloropsis gaditana, Rhodomonas marina, and Isochrysis sp. were cultivated in media with various nutrient concentrations, and the biomass was analyzed for protein and fatty acid contents. The long chain polyunsaturated fatty acid (LC-PUFA) and protein contents were maximized in media with high nutrient concentrations. Under these conditions, the reduction in the (SFA + MUFA)/PUFA ratio (by as much as 83%) indicated that R. marina and N. gaditana shifted preference towards PUFA synthesis. The ∑ω3/∑ω6 ratio indicated that R. marina preferentially synthesized ω3 FA towards high nutrient concentrations (depicted by an eightfold increase) in contrast to Isochrysis sp. (which yielded a 35% reduction). In addition, the limitations of LC-PUFA biosynthesis at the level of its precursors (e.g. C18:2ω6, C18:3ω3, C18:4ω3) and further conversion to LC-PUFA as nutrients were increased, suggesting that external variations induced changes in the sets of enzymes that maintain the desaturation and elongation pathways of FA. The present study provides novel insights into the regulation of LC-PUFA biosynthesis and facilitates the modeling of microalgal FA patterns depending on the field of application.info:eu-repo/semantics/publishedVersio

Current status of turbulent dynamo theory: From large-scale to small-scale dynamos

Several recent advances in turbulent dynamo theory are reviewed. High resolution simulations of small-scale and large-scale dynamo action in periodic domains are compared with each other and contrasted with similar results at low magnetic Prandtl numbers. It is argued that all the different cases show similarities at intermediate length scales. On the other hand, in the presence of helicity of the turbulence, power develops on large scales, which is not present in non-helical small-scale turbulent dynamos. At small length scales, differences occur in connection with the dissipation cutoff scales associated with the respective value of the magnetic Prandtl number. These differences are found to be independent of whether or not there is large-scale dynamo action. However, large-scale dynamos in homogeneous systems are shown to suffer from resistive slow-down even at intermediate length scales. The results from simulations are connected to mean field theory and its applications. Recent work on helicity fluxes to alleviate large-scale dynamo quenching, shear dynamos, nonlocal effects and magnetic structures from strong density stratification are highlighted. Several insights which arise from analytic considerations of small-scale dynamos are discussed.Comment: 36 pages, 11 figures, Spa. Sci. Rev., submitted to the special issue "Magnetism in the Universe" (ed. A. Balogh

Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment

In this paper, we review theoretical and experimental research on rare region effects at quantum phase transitions in disordered itinerant electron systems. After summarizing a few basic concepts about phase transitions in the presence of quenched randomness, we introduce the idea of rare regions and discuss their importance. We then analyze in detail the different phenomena that can arise at magnetic quantum phase transitions in disordered metals, including quantum Griffiths singularities, smeared phase transitions, and cluster-glass formation. For each scenario, we discuss the resulting phase diagram and summarize the behavior of various observables. We then review several recent experiments that provide examples of these rare region phenomena. We conclude by discussing limitations of current approaches and open questions.Comment: 31 pages, 7 eps figures included, v2: discussion of the dissipative Ising chain fixed, references added, v3: final version as publishe

Computational Physics on Graphics Processing Units

The use of graphics processing units for scientific computations is an emerging strategy that can significantly speed up various different algorithms. In this review, we discuss advances made in the field of computational physics, focusing on classical molecular dynamics, and on quantum simulations for electronic structure calculations using the density functional theory, wave function techniques, and quantum field theory.Comment: Proceedings of the 11th International Conference, PARA 2012, Helsinki, Finland, June 10-13, 201