Convergence of unilateral problems for monotone operators

We prove some new results on the convergence of variational inequalities for monotone operators, when both the operator and the obstacle are perturbed.     

An unusual ring transformation: Reaction of phenyl 4-chromone-3-sulfonate with methyl 3-aminocrotonate

The novel benzoxathiinopyridines 8 and 9 were synthesized by ring transformation of phenyl 4-chromone-3-sulfonate ( 1 ) with methyl 3-aminocrotonate ( 2 ). The structures of 8 and 9 were determined by spectroscopic methods and the reaction courses for the formation of these compounds are discussed.     

Tetrathiafulvalene?Benzothiadiazoles as Redox‐Tunable Donor–Acceptor Systems: Synthesis and Photophysical Study

Electrochemical and photophysical analysis of new donor–acceptor systems 2 and 3 , in which a benzothiadiazole (BTD) unit is covalently linked to a tetrathiafulvalene (TTF) core, have verified that the lowest excited state can be ascribed to an intramolecular‐charge‐transfer (ICT) π(TTF)→π*(benzothiadiazole) transition. Owing to better overlap of the HOMO and LUMO in the fused scaffold of compound 3 , the intensity of the ¹ICT band is substantially higher compared to that in compound 2 . The corresponding CT fluorescence is also observed in both cases. The radical cation TTF^+. is easily observed through chemical and electrochemical oxidation by performing steady‐state absorption experiments. Interestingly, compound 2 is photo‐oxidized under aerobic conditions.     

Estimation of dermal and oral exposure of children to scented toys: analysis of the migration of fragrance allergens by dynamic headspace GC-MS

Fragrances capable of inducing contact allergy in skin potentially can migrate from the toy to the child via oral or dermal contacts. The goal of this work was the developing of an analytical method based on dynamic headspace GC-MS to determine the concentration of 24 fragrances in saliva or sweat simulant. Under optimized conditions, 5 mL of the migration simulant with 2 g sodium chloride were incubated for 10 min at 30°C. The headspace was purged at a flow rate of 50 mL/min. The compounds were quantified by internal calibration resulting in good linearity (>0.991). The recovery was greater than 66.3% for most of the compounds. The limits of detection ranged between 0.5 ng/mL for hydrophobic and 196.0 ng/mL for hydrophilic fragrances. The method was subsequently applied to seven real toys purchased from the market. The highest migration rate could be observed for benzyl benzoate with 268.0 ng/cm(2)/min. Based on the migration data measured, the ranges of dermal and oral exposure of children to fragrances in scented toys were calculated. The maximum oral and dermal exposure levels were estimated at 22.2 μg per kg body weight (BW) and day (d) for benzyl benzoate and 605.0 μg/kg BW/d for benzyl alcohol, respectively.     

Calculating statistics of complex networks through random walks with an application to the on-line social network Bebo

We develop a methodology with which to calculate typical network statistics by sampling a network through a random walk. By examining the statistics of degree and return times of walks which return to the same vertex, we can estimate characteristics of the giant component such as average clustering coefficient, degree distribution, degree correlations and network size. We confirm the validity of the methods using a variety of available network network data sets and then apply these methods to data collected by performing a random walk on the large on-line social networking website, Bebo. We find good agreement between our results and the results of previous studies of on-line social networks in which data collection was performed by a BFS (“snow-ball”) sampling algorithm. In particular, we find that the degree distribution exhibits a multi-scaling power-law tail and the network exhibits clustering and positive degree correlations.     

Schmelzpunktsbestimmungen

Ohne Zusammenfassung