Non-SUSY pp-branes delocalized in two directions, tachyon condensation and T-duality

We here generalize our previous construction [hep-th/0409019] of non-supersymmetric $p$-branes delocalized in one transverse spatial direction to two transverse spatial directions in supergravities in arbitrary dimensions ($d$). These solutions are characterized by five parameters. We show how these solutions in $d=10$ interpolate between D($p+2$)-anti-D($p+2$) brane system, non-BPS D$(p+1)$-branes (delocalized in one direction) and BPS D$p$-branes by adjusting and scaling the parameters in suitable ways. This picture is very similar to the descent relations obtained by Sen in the open string effective description of non-BPS D$(p+1)$ brane and BPS D$p$-brane as the respective tachyonic kink and vortex solutions on the D$(p+2)$-anti-D$(p+2)$ brane system (with some differences). We compare this process with the T-duality transformation which also has the effect of increasing (or decreasing) the dimensionality of the branes by one.Comment: 19 pages, late

Study on Intumescent Flame Retarded Polystyrene Composites with Improved Flame Retardancy

The flame retardancy and thermal stability of ammonium polyphosphate/tripentaerythritol (APP/TPE) intumescent flame retarded polystyrene composites (PS/IFR) combined with organically-modified layered inorganic materials (montmorillonite clay and zirconium phosphate), nanofiber (multiwall carbon nanotubs), nanoparticle (Fe2O3) and nickel catalyst were evaluated by cone calorimetry, microscale combustion calorimetry (MCC) and thermogravimetric analysis (TGA). Cone calorimetry revealed that a small substitution of IFR by most of these fillers (≤2%) imparted substantial improvement in flammability performance. The montmorillonite clay exhibited the highest efficiency in reducing the peak heat release rate of PS/IFR composite, while zirconium phosphate modified with C21H26NClO3S exhibited a negative effect. The yield and thermal stability of the char obtained from TGA correlated well with the reduction in the peak heat release rate in the cone calorimeter. Since intumesence is a condensed-phase flame process, the MCC results showed features different from those obtained from the cone calorimeter

Nomenclatural changes for selected Mordellidae (Coleoptera) in North America

New nomenclatural changes are presented for selected North American mordellid beetles (Coleoptera: Mordellidae). The following five genera are newly recorded fi.·om the United States: Mordellaria Ermisch 1950, Falsomordellistena Ermisch 1941, Mordellina Schilsky 1908, Mordellochroa Emery 1876, and Pseudotolida Ermisch 1950. The following species are transferred from Tomoxia and represent new combinations: Mordellaria borealis (LeConte 1862), Mordellaria fascifera (LeConte 1878), Mordellaria latipalpis (Ray 1946), Mordellaria serval (Say 1835), and Mordellaria undulata (Melsheimer 1845). The following species are transferred fi.·om Mordellistena and represent new combinations: Falsomordellistena hebraica (LeConte 1862) and Falsomordellistena pubescens (Fabricius 1798); Mordellina blatchleyi (Liljeblad 1945), Mordellina pilosella (Ray 1947), Mordellina pustulata (Melsheimer 1845), Mordellina ustulata (LeConte 1862), and Mordellina wichhami (Liljeblad 1945); Mordellochroa scapularis (Say 1824); Pseudotolida arida (LeConte 1862), Pseudotolida hnausi (Liljeblad 1945), and Pseudotolida lutea (Melsheimer 1845). Mordellina ustulata (LeConte 1862) represents a return to species rank after being treated as a subspecies of Mordellistena andreae LeConte 1862. There are a total of 17 genera of Mordellidae in America north of Mexico

Synergistic Effect of Carbon Nanotubes and Decabromodiphenyl Oxide/Sb\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e in Improving the Flame Retardancy of Polystyrene

Brominated flame retardant polystyrene composites were prepared by melt blending polystyrene, decabromodiphenyl oxide, antimony oxide, multi-wall carbon nanotubes and montmorillonite clay. Synergy between carbon nanotubes and clay and the brominated fire retardant was studied by thermogravimetric analysis, microscale combustion calorimetry and cone calorimetry. Nanotubes are more efficient than clay in improving the flame retardancy of the materials and promoting carbonization in the polystyrene matrix. Comparison of the results from the microscale combustion calorimeter and the cone calorimeter indicate that the rate of change of the peak heat release rate reduction in the microscale combustion calorimeter was slower than that in the cone. Both heat release capacity and reduction in the peak heat release rate in the microscale combustion calorimeter are important for screening the flame retardant materials; they show good correlations with the cone parameters, peak heat release rate and total heat released