Remarkable thermal stability of BF3-doped polyaniline

We show that the recently synthesized BF3-doped polyaniline (PANI) exhibits remarkable stability against thermal ageing. Unlike the protonated PANI, which shows rapid degradation of the conductivity on heating in air, BF3-doped PANI shows more than an order of magnitude improvement in conductivity. We employ x-ray photoelectron spectroscopy (XPS), fourier transform infra-red (FTIR) spectroscopy, and x-ray diffraction (XRD) to understand this unexpected phenomenon.Comment: 4 pages and 3 figures. To appear in Applied Physics Letters, Sept. 200

Non-additivity of van der Waals forces on liquid surfaces

We present an approach for modeling nanoscale wetting and dewetting of liquid surfaces that exploits recently developed, sophisticated techniques for computing van der Waals (vdW) or (more generally) Casimir forces in arbitrary geometries. We solve the variational formulation of the Young--Laplace equation to predict the equilibrium shapes of fluid--vacuum interfaces near solid gratings and show that the non-additivity of vdW interactions can have a significant impact on the shape and wetting properties of the liquid surface, leading to very different surface profiles and wetting transitions compared to predictions based on commonly employed additive approximations, such as Hamaker or Derjaguin approximations.Comment: 5 pages (including abstract, acknowledgments, and references), 3 figure

Evaluation of hypoglycemic activity of methanolic extract of Acorus calamus (linn). roots in alloxan induced diabetes rat model

Background: To evaluate hypoglycemic activity of methanolic extract of roots of Acorus calamus (AC) in alloxan induced diabetic albino rats and to compare with standard oral hypoglycemic drug glibenclamide.Methods: A total of 54 rats were used for this study. The study was done in two phases. In phase I, oral glucose tolerance test was done in 4 groups at 0, 30, 60 and 120 minutes after administration of AC in 3 different doses – 100, 150 and 200mg/kg to 3 different groups, with control being the fourth group. The dose of AC which caused maximal blood glucose lowering was selected for phase II. In phase II, rats were divided into 5 groups. First 2 groups were non diabetic groups which were given distilled water (DW) and AC respectively. Next 3 groups were alloxan induced diabetic groups which were given DW, AC and Glibencamide 0.5mg/kg po respectively. All drugs were given for 28 days and FBS was measured on 0, 3, 7, 14, 21, and 28th days.Results: In phase I, both AC 150 and 200mg/kg lowered blood glucose but their effect was comparable and thus lower dose - 150mg/kg was selected for phase II. In phase II, among non-diabetic groups, AC 150 mg/kg produced significant hypoglycemia in comparison with control group. Among diabetic groups, both AC 150 mg/kg and glibenclamide 0.5 mg/kg produced significant hypoglycemia in comparison with control group on all days. On days 3 and 7, hypoglycaemic action of AC 150mg/kg was not as much as Glibenclamide (p 0.05).Conclusions: AC 150mg/kg causes hypoglycemia in alloxan induced diabetic rats as well as nondiabetic rats

Performance evaluation of LoRa LPWAN technology for IoT-based blast-induced ground vibration system

The recent proliferation of wireless sensor networks (WSNs) evolution into the Internet of Things (IoT) vision enables a variety of low-cost monitoring applications which allows a seamless transfer of information via embedded computing and network devices. Ambiguous ground vibration can be induced by blasting demolition is a severe concern which grievously damages the nearby dwellings and plants. It is an indispensable prerequisite for measuring the blast-induced ground vibration (BIGV), accomplishing a topical and most active research area. Thus, proposed and developed an architecture which emphasizes the IoT realm and implements a low-power wide-area networks (LPWANs) based system. Especially, using the available Long-Range (LoRa) Correct as Radio Frequency (RF) module, construct a WSN configuration for acquisition and streaming of required data from and to an IoT gateway. The system can wirelessly deliver the information to mine management and surrounding rural peoples to aware of the intensity of BIGV level. In this article, an endeavor has been made to introduce a LoRa WAN connectivity and proved the potentiality of the integrated WSN paradigm by testing of data transmission-reception in a non-line of sight (NLOS) condition. The path loss metrics and other required parameters have been measured using the LoRa WAN technology at 2.4 GHz frequency

Constraining phases of quark matter with studies of r-mode damping in neutron stars

The r-mode instability in rotating compact stars is used to constrain the phase of matter at high density. The color-flavor-locked phase with kaon condensation (CFL-K0) and without (CFL) is considered in the temperature range 10^8K < T <10^{11} K. While the bulk viscosity in either phase is only effective at damping the r-mode at temperatures T > 10^{11} K, the shear viscosity in the CFL-K0 phase is the only effective damping agent all the way down to temperatures T > 10^8 K characteristic of cooling neutron stars. However, it cannot keep the star from becoming unstable to gravitational wave emission for rotation frequencies f ~ 56-11 Hz at T ~ 10^8-10^9 K. Stars composed almost entirely of CFL or CFL-K0 matter are ruled out by observation of rapidly rotating neutron stars, indicating that dissipation at the quark-hadron interface or nuclear crust interface must play a key role in damping the instability.Comment: 8 pages, 2 figure

High-density Skyrmion matter and Neutron Stars

We examine neutron star properties based on a model of dense matter composed of B=1 skyrmions immersed in a mesonic mean field background. The model realizes spontaneous chiral symmetry breaking non-linearly and incorporates scale-breaking of QCD through a dilaton VEV that also affects the mean fields. Quartic self-interactions among the vector mesons are introduced on grounds of naturalness in the corresponding effective field theory. Within a plausible range of the quartic couplings, the model generates neutron star masses and radii that are consistent with a preponderance of observational constraints, including recent ones that point to the existence of relatively massive neutron stars with mass M 1.7 Msun and radius R (12-14) km. If the existence of neutron stars with such dimensions is confirmed, matter at supra-nuclear density is stiffer than extrapolations of most microscopic models suggest.Comment: 27 pages, 5 figures, AASTeX style; to be published in The Astrophysical Journa

Numerical Simulation of the Hydrodynamical Combustion to Strange Quark Matter

We present results from a numerical solution to the burning of neutron matter inside a cold neutron star into stable (u,d,s) quark matter. Our method solves hydrodynamical flow equations in 1D with neutrino emission from weak equilibrating reactions, and strange quark diffusion across the burning front. We also include entropy change due to heat released in forming the stable quark phase. Our numerical results suggest burning front laminar speeds of 0.002-0.04 times the speed of light, much faster than previous estimates derived using only a reactive-diffusive description. Analytic solutions to hydrodynamical jump conditions with a temperature dependent equation of state agree very well with our numerical findings for fluid velocities. The most important effect of neutrino cooling is that the conversion front stalls at lower density (below approximately 2 times saturation density). In a 2-dimensional setting, such rapid speeds and neutrino cooling may allow for a flame wrinkle instability to develop, possibly leading to detonation.Comment: 5 pages, 3 figures (animations online at http://www.capca.ucalgary.ca/~bniebergal/webPHP/research.php

Study of Ornamental Fish Diversity and Water Quality of Adda Hole Stream, Kabbinale Forest Range, Western Ghats

Addahole stream belongs to Kabbinale forest of Gundia region. The water quality and ornamental fish diversity were examined. The stream water is fast and slow flowing with clear water and rocky, sandy, leafy substrate. This stream is about 14 kms long, perennial and has different habitats with diverse ornamental fish population. Results revealed the mean values of water quality of all samples collected from different sampling sites were pH 5.50, Water temperature 27.5°C, dissolved oxygen 6.32 mg/l and total dissolved solids 53.06 mg/l. The mean air temperature was 30.3°C. Fish diversity showed presence of twelve different species, belonging to six different families, of which the family Cyprinidae was dominant with Rasboradaniconius and Puntiussps being the most abundant in all seasons. Fish diversity is correlated with physicochemical parameters. The total number of taxa and individuals showed positive correlation with water and air temperature. But it showed negative correlation with dissolved oxygen and positive correlation with total dissolved solids. Shannon-Weaver diversity indices showed positive correlation with air temperature

The Strange Star Surface: A Crust with Nuggets

We reexamine the surface composition of strange stars. Strange quark stars are hypothetical compact stars which could exist if strange quark matter was absolutely stable. It is widely accepted that they are characterized by an enormous density gradient ($~10^{26}$ g/cm$^4$) and large electric fields at surface. By investigating the possibility of realizing a heterogeneous crust, comprised of nuggets of strange quark matter embedded in an uniform electron background, we find that the strange star surface has a much reduced density gradient and negligible electric field. We comment on how our findings will impact various proposed observable signatures for strange stars.Comment: 4 pages, 2 figure