Visual tool for estimating the fractal dimension of images

This work presents a new Visual Basic 6.0 application for estimating the fractal dimension of images, based on an optimized version of the box-counting algorithm. Following the attempt to separate the real information from noise, we considered also the family of all band-pass filters with the same band-width (specified as parameter). The fractal dimension can be thus represented as a function of the pixel color code. The program was used for the study of paintings cracks, as an additional tool which can help the critic to decide if an artistic work is original or not. In its second version, the application was extended for working also with csv files and three-dimensional images.Comment: A new version was accepted to Computer Physics Communications doi:10.1016/j.cpc.2009.12.00

The potential of flavonoids as natural antioxidants and UV light stabilizers for polypropylene

This article presents a study on the stabilization of polypropylene against thermo-oxidation and UV radiation by using natural phenolic compounds derived from the structures of flavonoids: a flavone (chrysin), a flavanol (quercetin), two flavanone glycosides (hesperidin and naringin), and flavanoligand (silibinin). Thermal stabilization has been assessed in an oxidizing atmosphere by means of differential scanning calorimetry both in isothermal and in dynamic conditions. In addition, the effectiveness of these phenolic compounds as thermal stabilizers at high temperature has been quantified with the use of thermogravimetric analysis. Stabilization against UV radiation has been estimated by studying the morphology changes of the exposed surfaces by scanning electron microscope (SEM); also, surface chemical changes have been followed by infrared spectroscopy. Global results show that flavonoid compounds of type flavonols (quercetin and silibinin) provide the best results in stabilizing both against oxidation and against the action of UV radiation. (c) 2012 Wiley Periodicals, Inc.This study is part of the project IPT-310000-2010-037, "ECOTEX-COMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character" funded by the "Ministerio de Ciencia e Innovacion," with an aid of 189540.20 euros, within the "Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica 2008-2011" and funded by the European Union through FEDER funds, "Technology Fund 2007-2013, Operational Programme on R+D+i for and on behalf of the companies." Also, Generalitat Valenciana Ref: ACOMP/2012/087 is acknowledged for financial support.Samper Madrigal, MD.; Fages, E.; Fenollar Gimeno, OÁ.; Boronat Vitoria, T.; Balart Gimeno, RA. (2013). The potential of flavonoids as natural antioxidants and UV light stabilizers for polypropylene. Journal of Applied Polymer Science. 129(4):1707-1716. https://doi.org/10.1002/app.38871S170717161294Koontz, J. L., Marcy, J. E., O’Keefe, S. F., Duncan, S. E., Long, T. E., & Moffitt, R. D. (2010). Polymer processing and characterization of LLDPE films loaded with α-tocopherol, quercetin, and their cyclodextrin inclusion complexes. Journal of Applied Polymer Science, 117(4), 2299-2309. doi:10.1002/app.32044Mallégol, J., Carlsson, D. ., & Deschênes, L. (2001). A comparison of phenolic antioxidant performance in HDPE at 32–80°C. Polymer Degradation and Stability, 73(2), 259-267. doi:10.1016/s0141-3910(01)00086-6Peltzer, M., Wagner, J. R., & Jiménez, A. (2007). Thermal characterization of UHMWPE stabilized with natural antioxidants. Journal of Thermal Analysis and Calorimetry, 87(2), 493-497. doi:10.1007/s10973-006-7453-1Strandberg, C., & Albertsson, A.-C. (2005). Process efficiency and long-term performance of α-tocopherol in film-blown linear low-density polyethylene. Journal of Applied Polymer Science, 98(6), 2427-2439. doi:10.1002/app.22435Jipa, S., Zaharescu, T., Setnescu, R., Gorghiu, L. M., Dumitrescu, C., Santos, C., … Gigante, B. (2005). Kinetic approach on stabilization of LDPE in the presence of carnosic acid and related compounds. I. Thermal investigation. Journal of Applied Polymer Science, 95(6), 1571-1577. doi:10.1002/app.21372Salmieri, S., & Lacroix, M. (2006). Physicochemical Properties of Alginate/Polycaprolactone-Based Films Containing Essential Oils. Journal of Agricultural and Food Chemistry, 54(26), 10205-10214. doi:10.1021/jf062127zBonilla, J., Atarés, L., Vargas, M., & Chiralt, A. (2012). Effect of essential oils and homogenization conditions on properties of chitosan-based films. Food Hydrocolloids, 26(1), 9-16. doi:10.1016/j.foodhyd.2011.03.015Dopico-García, M. S., Castro-López, M. M., López-Vilariño, J. M., González-Rodríguez, M. V., Valentão, P., Andrade, P. B., … Abad, M. J. (2010). Natural extracts as potential source of antioxidants to stabilize polyolefins. Journal of Applied Polymer Science, 119(6), 3553-3559. doi:10.1002/app.33022López-de-Dicastillo, C., Alonso, J. M., Catalá, R., Gavara, R., & Hernández-Muñoz, P. (2010). Improving the Antioxidant Protection of Packaged Food by Incorporating Natural Flavonoids into Ethylene−Vinyl Alcohol Copolymer (EVOH) Films. Journal of Agricultural and Food Chemistry, 58(20), 10958-10964. doi:10.1021/jf1022324Pérez-Gregorio, R. M., García-Falcón, M. S., Simal-Gándara, J., Rodrigues, A. S., & Almeida, D. P. F. (2010). Identification and quantification of flavonoids in traditional cultivars of red and white onions at harvest. Journal of Food Composition and Analysis, 23(6), 592-598. doi:10.1016/j.jfca.2009.08.013Iacopini, P., Baldi, M., Storchi, P., & Sebastiani, L. (2008). Catechin, epicatechin, quercetin, rutin and resveratrol in red grape: Content, in vitro antioxidant activity and interactions. Journal of Food Composition and Analysis, 21(8), 589-598. doi:10.1016/j.jfca.2008.03.011Liu, H., Du, X., Yuan, Q., & Zhu, L. (1990). Optimisation of enzyme assisted extraction of silybin from the seeds of Silybum marianum by Box-Behnken experimental design. Phytochemical Analysis, 20(6), 475-483. doi:10.1002/pca.1149Wolfman, C., Viola, H., Paladini, A., Dajas, F., & Medina, J. H. (1994). Possible anxiolytic effects of chrysin, a central benzodiazepine receptor ligand isolated from Passiflora Coerulea. Pharmacology Biochemistry and Behavior, 47(1), 1-4. doi:10.1016/0091-3057(94)90103-1Al-Ashaal, H. A., & El-Sheltawy, S. T. (2011). Antioxidant capacity of hesperidin fromCitruspeel using electron spin resonance and cytotoxic activity against human carcinoma cell lines. Pharmaceutical Biology, 49(3), 276-282. doi:10.3109/13880209.2010.509734Sudto, K., Pornpakakul, S., & Wanichwecharungruang, S. (2009). An efficient method for the large scale isolation of naringin from pomelo (Citrus grandis) peel. International Journal of Food Science & Technology, 44(9), 1737-1742. doi:10.1111/j.1365-2621.2009.01989.xPeltzer, M., & Jiménez, A. (2009). Determination of oxidation parameters by DSC for polypropylene stabilized with hydroxytyrosol (3,4-dihydroxy-phenylethanol). Journal of Thermal Analysis and Calorimetry, 96(1), 243-248. doi:10.1007/s10973-008-9389-0VAN KREVELEN, D. W. (1997). CALORIMETRIC PROPERTIES. Properties of Polymers, 109-127. doi:10.1016/b978-0-444-82877-4.50012-3Chandramouleeswaran, S., Mhaske, S. T., Kathe, A. A., Varadarajan, P. V., Prasad, V., & Vigneshwaran, N. (2007). Functional behaviour of polypropylene/ZnO–soluble starch nanocomposites. Nanotechnology, 18(38), 385702. doi:10.1088/0957-4484/18/38/385702Heim, K. E., Tagliaferro, A. R., & Bobilya, D. J. (2002). Flavonoid antioxidants: chemistry, metabolism and structure-activity relationships. The Journal of Nutritional Biochemistry, 13(10), 572-584. doi:10.1016/s0955-2863(02)00208-5Gugumus, F. (1998). Thermooxidative degradation of polyolefins in the solid state—6. Kinetics of thermal oxidation of polypropylene. Polymer Degradation and Stability, 62(2), 235-243. doi:10.1016/s0141-3910(98)00004-4Richaud, E., Farcas, F., Fayolle, B., Audouin, L., & Verdu, J. (2006). Hydroperoxide titration by DSC in thermally oxidized polypropylene. Polymer Testing, 25(6), 829-838. doi:10.1016/j.polymertesting.2006.04.010Rabello, M. ., & White, J. . (1997). Crystallization and melting behaviour of photodegraded polypropylene — I. Chemi-crystallization. Polymer, 38(26), 6379-6387. doi:10.1016/s0032-3861(97)00213-9Rajakumar, K., Sarasvathy, V., Chelvan, A. T., Chitra, R., & Vijayakumar, C. T. (2011). Effect of iron carboxylates on the photodegradability of polypropylene. II. Artificial weathering studies. Journal of Applied Polymer Science, 123(5), 2968-2976. doi:10.1002/app.34946Kaczmarek, H., Ołdak, D., Malanowski, P., & Chaberska, H. (2005). Effect of short wavelength UV-irradiation on ageing of polypropylene/cellulose compositions. Polymer Degradation and Stability, 88(2), 189-198. doi:10.1016/j.polymdegradstab.2004.04.017Yakimets, I., Lai, D., & Guigon, M. (2004). Effect of photo-oxidation cracks on behaviour of thick polypropylene samples. Polymer Degradation and Stability, 86(1), 59-67. doi:10.1016/j.polymdegradstab.2004.01.01

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal