Oxidation of several liquid, long chain hydrocarbons (alkanes, alkenes, arenes, and a light gas oil, LCGO, product of a coking process) has been studied by using a low-pressure high-voltage oxygen plasma. Olefins were readily oxidized to epoxides and carbonyl compounds, O(3P) being the active species in the plasma. At long treatment times the saturated chains of the olefins also reacted to produce secondary alcohols and ketones. These compounds and tertiary alcohols, only when tertiary carbons were present, were obtained with alkanes. At 5 min 4-phenyl-1-butene showed reaction mostly on the olefinic CC, followed by oxidation of the aromatic ring. At 120 min the olefinic fraction of the compound was eliminated and the reaction of the saturated −CH2− groups represented only 0.6% of the total conversion. LCGO, with a composition of 65.1% alkanes, 34.8% aromatics, and 3.1% olefins, was treated under similar conditions used for the model compounds. At 120 min the olefinic fraction of the mixture was eliminated and the cetane number, a parameter indicating the quality of fuel oils, was improved by 66% without any additional treatment.

12In the present work, an HPLC method is proposed to simultaneously detect and quantify 13 water and fat soluble vitamins, phenolic compounds, carotenoids and chlorophylls in a 14 single run, by using an ultradeactivated C18 column and gradient separation using 15 trifluoroacetic acid, water and methanol. It is shown that the HPLC method provides 16 baseline separation of all these compounds with good resolution values in 40 min. 17Moreover, other figures of merit of the method show a good linear response and low 18 detection limits for all the compounds considered in the present study. Furthermore, the 19 usefulness of this method is demonstrated via its successful application to the analysis 20 of different beverages from different natural origin (orange, strawberry, apple, peach 21 pineapple, plum and blackcurrant juices, soybean milk, beers) without the need of any 22 previous sample preparation. A good correlation is also found by comparing the total 23 phenol content (measured by Folin-Ciocalteau method) with the sum of total phenolic 24 compounds obtained using the proposed HPLC method. By using statistical tools, the 25 main compounds associated with antioxidant activity of the extracts (measured by 26 DPPH radical scavenging) were assessed. 27 can play an important role in the associated bioactivity of a food product and, therefore, 56 their determination can also be of great importance for food and nutrition studies. These 57 food components have the common property of being labile and so degraded by light, 58 heat or oxygen, also they are extremely complex, with dozens of very similar 59 components or isomers which makes its separation extremely difficult as next 60 discussed. 61The basic feature of all polyphenols is the presence of one or more hydroxylated 62 aromatic rings, which seemed to be, in fact, responsible for their properties as radical 63 scavengers [10][11][12][13][14][15][16] carotenoids are efficient free-radical scavengers, and they enhance the immune system 70 [20][21][22][23][24][25][26]. On the other hand, some biological effects have also been associated to 71 chlorophylls [20]. The analysis of carotenoids and chlorophylls is commonly done by 72 HPLC and several methods have been developed to simultaneously determine these 73 type of compounds [27][28][29]. 74The goal of this work was to develop an HPLC method (using diode array detection) 75 The antioxidant activity of beverages was measured using the DPPH method. All the 138 measurements were carried out according to a procedure previously used in juices by 139Klimczak et al. [30]. Briefly, 0.1 mL of juice sample (filtered using syringe nylon filter 140 of 0.45 μm and diluted with distilled water 10:1) was added to 2.46 mL of 1,1-diphenyl-141 2-picrylhydrazyl radical (DPPH  ; 0.025 g·L −1 in 50% ethanol) and mixed by vortex for 142 1 min. The absorbance of the samples was measured at 515 nm every 5 min for 30 min 143 using the spectrophotometer Genesys (Thermo Finnigan, Madrid, Spain). For each 144 sample, three separ...

Uno de los nuevos retos a los que se tendrá que enfrentar la Educación Física en España y a nivel mundial son los nuevos colectivos emergentes. Dentro de este perfil de población despierta nuestro interés los denominados “jóvenes en riesgo”. En los últimos 30 años se han desarrollado diferentes programas de intervención con estas poblaciones con fines de prevención e integración y donde la actividad física y el deporte constituyen la herramienta fundamental de trabajo. Este artículo presenta la propuesta de un modelo de intervención para educar en valores a jóvenes en riesgo a través de la actividad física y el deporte estructurado por fases y estrategias operativas. Nuestra experiencia nos muestra que para asegurar el éxito en estas intervenciones es importante tener presente el perfil del educador y ante todo conseguir una mayor implicación social por parte de todos los sectores implicados en este problema. Palabras-Clave: