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The actuation properties of piezo-electric polyvinyl di fluoride (PVDF) can be improved by mixing electro-resistive carbon nano tubes (CNT’s) and various mechanisms have been highlighted recently. Herewith, we proposed a simple route for the synthesis of PVDF/CNT composite by mixing a proper concentration of PVDF with CNT in N-Methyl-2-pyrrolidone (NMP) by using solution phase co-precipitation techniques. We observed that at a certain concentration ratio of PVDF and CNT, it formed well crystalline morphology with specific structures. After optimizing their concentrations, we mixed carbonic and sulphonic acid functionalized CNT with PVDF at a certain ratio and prepared the acid functionalized PVDF/CNT composites. The composite materials were characterized by various spectroscopic and microscopic techniques such as XRD, FTIR, thermal and FE-SEM analyses. From the FE-SEM analysis, the sheikh kabab morphology was observed in PVDF while more pronounced and oriented structure was found in case of CNT as well as their carbonic acid functionalized product. As an application, the synthesized materials are studied for actuation purposes by investigating their properties using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis. It was observed that the actuation properties of PVDF was enhanced while mixed with CNT and carbonic acid functionalized CNT although it remained unchanged in case of sulfonic acid functionalized CNT. In case of PVDF and carbonic acid functionalized CNT, a higher saturation current of 2.7 mA was observed while for bare PVDF in NMP, a reduced value of 0.0087 mA was observed. The present synthesis route and the application process is simple, less time consuming and could be extended for the fabrication of other composite materials for their potential application as actuator and in other technologically important energy related fields. [ABSTRACT FROM AUTHOR]

Previously developed regression formulae for estimating body mass in dogs and wolves based on cranial and mandibular dimensions are evaluated using modern canid specimens of known weight at death. Some of these equations proved reliable, but others have large standard errors of estimate and likely produce unreliable mass estimates. New sets of equations for estimating body mass in dogs and wolves are produced using our datasets, including a set of equations developed from combining the dog and wolf biometric data into a single population. The resulting regression equations allow body mass to be estimated from a series of cranial and mandibular dimensions with relatively low errors. Further, our datasets include larger numbers of specimens of larger ranges of body mass than in these previous studies. When the equations are applied to a suite of dogs and one wolf from Eastern Siberia, several patterns emerge. First, hunter-gatherers' dogs in this region vary widely in terms of body size, even within a limited geographic area and time period. Some were quite large, similar in size to modern Siberian huskies. Second, pastoralists' dogs are less variable in terms of body mass, but this may reflect the nature of our samples. In particular, pastoralists' dogs nearly all were sacrificed juvenile dogs, some of which appear to have been eaten. These dogs seem to have been approached adult body size when they were selected for sacrifice. Finally, our findings help to highlight the need for further refinement in methods used to study ancient canid remains. [ABSTRACT FROM AUTHOR]

Abstract: Direct hydroxylation of aromatic hydrocarbons, viz. benzene, toluene and anisole to phenol, cresols and methoxyphenols respectively has been studied by using hydrogen peroxide as oxidant and vanadium based systems such as vanadyl tetraphenoxyphthalocyanine, VO(acac)2, 20% V2O5/Al2O3, 14% V2O5/TiO2, 11% V2O5/ZiO2 as catalysts in acetonitrile under biphasic reaction conditions. Among the various vanadium-based catalysts studied, vanadyl tetraphenoxyphthalocyanine (VOPc) was found to be best from conversion as well as selectivity for hydroxy compounds points of view. The effect of various reaction parameters such as H2O2/substrate molar ratio, reaction temperature, solvent and catalyst concentration was systematically studied. [Copyright &y& Elsevier]