3,028 research outputs found

    Collective flow in heavy ion collisions at intermediate energies

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    We present results of a flow analysis for the set of reactions of 124,129Xe projectiles and 112,124Sn targets at incident energies 100 and 150 A MeV studied with the INDRA detector at GSI. The dependence on centrality and on p_t of the directed and elliptic flow are determined for isotopically selected reaction products with Z \le 3. The flow parameters v_1 and v_2, in general, follow expected trends but isotopic effects are small.Comment: 3 pages, 2 figures, contributed talk at INPC, Tokyo, June 3-8, 2007, to appear in the proceeding

    Classifying Tweet Level Judgements of Rumours in Social Media

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    Social media is a rich source of rumours and corresponding community reactions. Rumours reflect different characteristics, some shared and some individual. We formulate the problem of classifying tweet level judgements of rumours as a supervised learning task. Both supervised and unsupervised domain adaptation are considered, in which tweets from a rumour are classified on the basis of other annotated rumours. We demonstrate how multi-task learning helps achieve good results on rumours from the 2011 England riots

    Biorefinery concept with green solvents towards the phenolic valorization

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    The efficient separation, hydrolysis and conversion of principal components of lignocellulosic biomass allows to produce chemicals and value added compounds. Ionic liquids (ILs) have been used for the pre-treatment and fractionation of biomass.1-3 The pre-treatment reveals that phenolic compounds were found in the IL phase. This work was devoted for the extraction of phenolic compounds from the recovered IL liquid using several adsorption resins in small scale batch processes. Phenolic compounds, such as vanillin, catechol and flavonoids were identified in extraction samples and also quantified. Temperature, residence time and water amount were evaluated in order to find optimal extraction conditions of phenolic compounds from IL

    Problems in production of uniformed, hollowed push-pull rods

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    The article presents the results of research on uniformed push-pull rods endings. The aim of research was the analysis of characteristics and the possibility of durability improvement, in particular fatigue durability. The research included microstructure analysis and numerical modelling of manufacturing process. The influence of technological parameters on characteristics improvement was also analysed. The obtained results will be used to develop a new method of forming, and to produce sample elements which will be subjected to verification trials

    Ionic liquids as a tool for lignocellulosic biomass fractionation

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    Lignocellulosic biomass composes a diversity of feedstock raw materials representing an abundant and renewable carbon source. In majority lignocellulose is constituted by carbohydrate macromolecules, namely cellulose and hemicellulose, and by lignin, a polyphenilpropanoid macromolecule. Between these biomacromolecules, there are several covalent and non-covalent interactions defining an intricate, complex and rigid structure of lignocellulose. The deconstruction of the lignocellulosic biomass makes these fractions susceptible for easier transformation to large number of commodities including energy, chemicals and material within the concept of biorefinery. Generally, the biomass pre-treatment depends on the final goal in the biomass processing. The recalcitrance of lignocellulose materials is the main limitation of its processing once the inherent costs are excessively high for the conventional pre-treatments. Furthermore, none of the currently known processes is highly selective and efficient for the satisfactory and versatile use, thus, new methodologies are still studied broadly. The ionic liquid technology on biomass processing is relatively recent and first studies were focused on the lignocellulosic biomass dissolution in different ionic liquids (ILs). The dissolution in IL drives to the structural changes in the regenerated biomass by reduction of cellulose crystallinity and lignin content contrasting to the original biomass. These findings provided ILs as tools to perform biomass pre-treatment and the advantageous use of their specific properties over the conventional pre-treatment processes. This review shows the critical outlook on the study of biomass dissolution and changes occurred in the biomass during this process as well as on the influence of several crucial parameters that govern the dissolution and further pre-treatment process. The review of currently known methods of biomass fractionation in IL and aqueous-IL mixtures is also discussed here and perspectives regarding these topics are given as well
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