Visibility-preserving convexifications using single-vertex moves

Devadoss asked: (1) can every polygon be convexified so that no internal visibility (between vertices) is lost in the process? Moreover, (2) does such a convexification exist, in which exactly one vertex is moved at a time (that is, using single-vertex moves)? We prove the redundancy of the “single-vertex moves” condition: an affirmative answer to (1) implies an affirmative answer to (2). Since Aichholzer et al. recently proved (1), this settles (2).     

Effects of international collaboration and status of journal on impact of papers

This study examines the effect of international collaboration of Slovenian authors and the status of journals where papers are published (as determined by their impact factors) on the impact of papers as measured by the number of citations papers receive. Research programme groups working in Slovenia in the 2004–2008 period in the fields of physics, chemistry, biology, biotechnology, and medical science were used for analyses. The results of the analyses show that the effects of the two factors differ among the fields. We discuss possible reasons for this, including the possibility that differences are the result of Slovenia’s science policy.     

Detection of clenbuterol in beef meat,liver and kidney by mid‐infrared spectroscopy (FT‐Mid IR) and multivariate analysis

Mid‐infrared spectroscopy (FT‐Mid IR) coupled with multivariate analysis was used to predict clenbuterol in beef meat, liver and kidney. A SIMCA model was also developed to discriminate between pure (beef meat, liver and kidney) and spiked with clenbuterol samples (beef meat‐clenbuterol, liver‐clenbuterol and kidney‐clenbuterol). The best models to predict clenbuterol concentrations were obtained using the partial least squares algorithm (PLS) with a R² > 0.9 and SEC and standard error of prediction <0.296 and 0.324, respectively. The SIMCA model used to discriminate pure and spiked with clenbuterol samples showed 100% correct classification rate. Methods detection limit was 2 μg kg^?1. FT‐Mid IR coupled with chemometrics could be a simple and rapid screening tool for monitoring clenbuterol in beef meat, liver and kidney implicated in food poisoning. This method could be use for screening purposes.     

Comparison of the stability of palm olein and a palm olein/canola oil blend during deep‐fat frying of chicken nuggets and French fries

Stability of palm olein (PO) and a blend 50% palm olein/50% canola oil (POC) during deep‐fat frying at 180 °C of French fries (FF) or chicken nuggets (CN) was studied through the determination of physical and chemical parameters in the fresh and used oils. Degradation at the end of the study resulted in total polar compounds of 12–13.5% for PO and 11.5–14.5% for POC and viscosity of 65–123.3 cP for PO and 63–72.8 cP for POC. Lower peroxide values (5.33–6.32) were obtained for the blend (PO had 5.21–8.55). Food type affected colour parameters and p‐anisidine value of the oils. For CN, the lowest fat content and higher hardness were obtained when they were fried in PO. CN caused a faster deterioration in the oils, in comparison with FF, especially in POC. Gas chromatography allowed to observe differences in fatty acids composition for both used oils.     

RIGHT TO THE SUBURB? RETHINKING LEFEBVRE AND IMMIGRANT ACTIVISM

ABSTRACT: In the face of increasing migration by Latinos to suburbs and multi‐scalar policies criminalizing immigrants, municipalities are increasingly confronting the question, Who has the Right to the Suburb? We seek to better understand how the tensions between suburbanites and Latino immigrants are addressed by municipal governments as immigration enforcement is increasingly rescaled to the local level. Case studies of Maywood and Costa Mesa in Southern California suggest responses are by no means similar and can actually be contrasting, given the city's historical trajectories, socio‐economic status, political leadership, and networks of activists. Suburban struggles are often assumed to be conservative and as a result are undertheorized as sites of liberatory struggle. While the urban realm remains the most visible stage of social movements, this paper suggests immigrant activism is increasingly being generated in suburbs, election‐based organizing can be an effective gateway to municipal level change, and seeking to expand or constrict the Right to the City necessarily entails multi‐scalar efforts.     

Influence of CTAB on the electrochemical behavior of dopamine and on its analytic determination in the presence of ascorbic acid

This research work concerns the electrochemical study of dopamine and ascorbic acid in the presence of the cationic surfactant cetyltrimethylammonium bromide. From this study is possible to note that the cetyltrimethylammonium bromide greatest influence was on the dopamine, because it disfavors both its oxidation and reduction, thereby giving a smaller heterogeneous rate constant, k ⁰, value than in its absence, provoking that the process tends to irreversibility. On the contrary, for the ascorbic acid case, its oxidation was favored; these effects can influence the separation of the dopamine and ascorbic acid voltammetric signals up to 453 mV. Further, the method could be optimized through differential pulse voltammetry to proceed with the analytic determination of dopamine in the presence of ascorbic acid displaying usable analytic parameters, namely: a linearity range of 0–130 μM, a sensitivity of (6.318 ± 0.002) μA mM^?1, a detection limit of (11 ± 0.1) μM, and a quantification limit of (37 ± 0.2) μM, which made it possible to effect the quantification on a commercial pharmaceutical sample.     

Induction heating of mastic containing conductive fibers and fillers

The objective of this research is to examine the induction heating of mastic through the addition of electrically conductive fillers and fibers (graphite and steel wool), and to prove that this material can be healed with induction energy. The effect of fibers content, sand–bitumen ratio and the combination of fillers and fibers on the induction heating of mastic was investigated. It was found that there is an optimum content of fibers for each sand–bitumen ratio, above which mastic cannot be heated any more. This optimum seems to coincide with the optimum electrical conductivity of the mixture shown in [1]. It was found that the maximum temperature reached within a certain time period was a function of the sand–bitumen ratio (s–b) and of the volume content of fibers. The mastic could be heated with the addition of a very low volume of conductive fibers. The fastest heating power was obtained with the mix with the maximum electrical conductivity. Gel-Permeation Chromatography (GPC) was also used to show that there is not ageing of bitumen during the heating process.