Transient temperature distribution in functionally graded graphite/Polymer nanocomposites based on temperature dependent properties

Transient heat conduction in a functionally graded graphite/polymer nanocomposite (FGN) plate is analyzed using finite element method (FEM). Stepwise gradient structure consisted of four different nanocomposite layers with 0, 5, 10 and 20 wt% of graphite. Thermal conductivity and specific heat capacity of the individual layers were determined using C-Therm TCi Thermal Conductivity Analyzer (Canada) in temperature range of -20 to 100 °C. Temperature history and temperature distribution across the thickness of the plate with two different configurations for two positive and negative temperature gradients are presented.

Methyl 3-[4-(4-nitrobenzyloxy)phenyl]propanoate

The title compound, C17H17NO5, crystallizes with two molecules (A and B) in the asymmetric unit. The conformational structures of the two molecules show small but significant differences in the dihedral angles between the two aryl rings with values of 18.8 (1)_ for molecule A and 7.5 (1)_ for molecule B. In molecule A, the propanoate group is twisted out of the plane of the benzene group [Car—Car—C—C torsion angle = _44.9 (2)_], while for molecule B, this group lies closer to the plane [Car—Car—C—C torsion angle = 8.6 (3)_]. C—H_ _ _O interactions characterize the crystalpacking interactions in this compound.

Sexual selection and the evolution of complex color patterns in dragon lizards

Many species have elaborate and complex coloration and patterning, which often differ between the sexes. Sexual selection may increase the size or intensity of color patches (elaboration) in one sex or drive the evolution of novel signal elements (innovation). The latter potentially increases color pattern complexity. Color pattern complexity may also be influenced by ecological factors related to predation and environment; however, very few studies have investigated the effects of both sexual and natural selection on color pattern complexity across species. We used a phylogenetic comparative approach to examine these effects in 85 species and subspecies of Australian dragon lizards (family Agamidae). We quantified color pattern complexity by adapting the Shannon–Wiener diversity index. There were clear sex differences in color pattern complexity, which were positively correlated with both sexual dichromatism and sexual size dimorphism, consistent with the idea that sexual selection plays a significant role in the evolution of color pattern complexity. By contrast, we found little evidence of a link between environmental factors and color pattern complexity on body regions exposed to predators. Our results suggest that sexual selection rather than natural selection has led to increased color pattern complexity in males.

Practical amine functionalization of multi-walled carbon nanotubes for effective interfacial bonding

 Improved methods of functionalizing the surfaces of multi-walled carbon nanotubes (MWCNTs) have been investigated. It is shown that a level of primary amines of 2.3%, higher than previously reported for any nitrogen-containing gas plasma treatment, can be achieved using a mixture of N2 and H2, which is preferable to using NH3. Even higher levels (3.5%) of primary amines can be achieved by coating the MWCNTs with a thin layer of plasma polymerized heptylamine. In both cases, the highest levels were achieved using a combined continuous plus pulsed plasma mode which was superior to either continuous wave or pulsed wave alone. The integrity of the MWCNT structure is maintained by the plasma treatments, and the functionalized surface improves the dispersion of the MWCNTs and their interfacial bonding with epoxy, giving superior nanoindentation performance of the composites.

Understanding wettability changes from practical plasma functionalization of carbon nanotubes

Combining continuous wave and pulsed plasma modes enables strong interfacial bonding of high levels of desired surface functional groups. The method has been applied to a thin film of multiwalled carbon nanotubes, a nanostructured and relatively inert material, using N₂ + H₂ plasma. A high density of primary amine groups (~2.6%) was achieved without damaging the tube surface. Contact angle measurements, using different probe liquids, plus model calculations of surface energy agree well with the spectroscopy and electron microscope results, i.e., the polar part shows significant changes while the non-polar part was unchanged. These results indicate that the wettability changes in the thin film of carbon nanotubes by the plasma treatment are due to the changes in surface chemistry. This confirms the effectiveness and practicality of the improved plasma method that should greatly help the use of nanotubes in applications from biomaterials to nanocomposites.

Enhanced early nodulation of medicago truncatula co-inoculated with sinorhizobium medicae and achromobacter xylosoxidans

Efforts to increase the productivity and sustainability of agro-ecosystems have resulted in increased research focused on generating improved microbiological inoculant technologies. Plant growth-promoting rhizobacteria (PGPR) are one area receiving increased attention due to their potential for use as biofertilizers, plant-growth promoters, and biocontrol agents for weed and disease control in farming systems (Siddiqui, 2006).

The dingo and biodiversity conservation : response to Fleming et al. (2012)

Several authors have recently argued that dingoes could be used to help conserve biodiversity in Australia. Fleming et al. (2012) [Australian Mammalogy 34, 119–131] offer the alternative view that restoration of dingo predation is unlikely to help native species, and is more likely to do harm. We think many of the arguments used by Fleming et al. to reach that conclusion are either unsound or beside the point, and we explain why.