Polyhedral separation via difference of convex (DC) programming

We consider polyhedral separation of sets as a possible tool in supervised classification. In particular, we focus on the optimization model introduced by Astorino and Gaudioso (J Optim Theory Appl 112(2):265–293, 2002) and adopt its reformulation in difference of convex (DC) form. We tackle the problem by adapting the algorithm for DC programming known as DCA. We present the results of the implementation of DCA on a number of benchmark classification datasets

Novel Strategies for the Preparation and Functionalization of Noble Metallic and Titanium Dioxide Nanoparticles

Water-soluble, monodisperse AgNPs were synthesized using benzotriazole-maleimide as stabilizer. DNA-AgNP conjugates obtained through Diels-Alder cycloaddition were utilized for DDI of enzyme which retained its activity after the immobilization process. CuNPs in aqueous solutions using ascorbic acid and dopamine-based linkers were prepared. They produced ROS, and could be employed as enzyme mimetics and as catalysts for the degradation of harmful fluorescent dyes and antibiotics

Narrow double-peaked emission lines of SDSS J131642.90+175332.5: signature of a single or a binary AGN in a merger, jet-cloud interaction, or unusual narrow-line region geometry

We present an analysis of the active galaxy SDSS J131642.90+175332.5, which is remarkable because all of its narrow emission lines are double-peaked, and because it additionally shows an extra broad component (FHWM ~ 1400 km/s) in most of its forbidden lines, peaking in between the two narrow systems. The peaks of the two narrow systems are separated by 400--500 km/s in velocity space. The spectral characteristics of double-peaked [O III] emission have previously been interpreted as a signature of dual or binary active galactic nuclei (AGNs), among other models. In the context of the binary scenario, SDSS J131642.90+175332.5 is a particularly good candidate because not just one line but all of its emission lines are double-peaked. However, we also discuss a number of other scenarios which can potentially account for double-peaked narrow emission lines, including projection effects, a two-sided outflow, jet-cloud interactions, special narrow-line region (NLR) geometries (disks, bars, or inner spirals), and a galaxy merger with only one AGN illuminating two NLRs. We argue that the similarity of the emission-line ratios in both systems, and the presence of the very unusual broad component at intermediate velocity, makes a close pair of unrelated AGNs unlikely, and rather argues for processes in a single galaxy or merger. We describe future observations which can distinguish between these remaining possibilities.Comment: ApJ Letters, 705, L20-L24, 2009 (November 1 issue); incl. 2 colour figure

Sol–gel carbons from ionothermal syntheses

Inorganic salt melts are used for the preparation of ceramics. It turns out that such ionothermal syntheses can also be employed in the chemistry of carbon. Carbon materials with improved application-relevant properties such as high surface area and large pore volume can be obtained. The way these properties are obtained strongly reminds on classic sol–gel synthesis, which displays a comparably easy approach toward such porous carbons. The central role of the solvent, i.e., the inorganic salt melt allows for variation of the chemical and morphological structure of carbon products. Interestingly, the use of inorganic salt melts may also give insights into the crystallization of carbon, if precursors are directly added to the hot melt, which additionally guarantees reorganizational dynamics to the pyrolysis intermediates