Searching for solar siblings among the HARPS data

The search for the solar siblings has been particularly fruitful in the last few years. Until now, there are four plausible candidates pointed out in the literature: HIP21158, HIP87382, HIP47399, and HIP92831. In this study we conduct a search for solar siblings among the HARPS high-resolution FGK dwarfs sample, which includes precise chemical abundances and kinematics for 1111 stars. Using a new approach based on chemical abundance trends with the condensation temperature, kinematics, and ages we found one (additional) potential solar sibling candidate: HIP97507.Comment: 4 pages, 2 figures, 1 table. Accepted in A&

Alternate islands of multiple isochronous chains in wave-particle interactions

We analyze the dynamics of a relativistic particle moving in a uniform magnetic field and perturbed by a standing electrostatic wave. We show that a pulsed wave produces an infinite number of perturbative terms with the same winding number, which may generate islands in the same region of phase space. As a consequence, the number of isochronous island chains varies as a function of the wave parameters. We observe that in all the resonances, the number of chains is related to the amplitude of the various resonant terms. We determine analytically the position of the periodic points and the number of island chains as a function of the wave number and wave period. Such information is very important when one is concerned with regular particle acceleration, since it is necessary to adjust the initial conditions of the particle to obtain the maximum acceleration.Comment: Submitte

Analysis of formulation effects in the dissolution of ibuprofen pellets

In this work the effects of citric acid and of two common fillers, lactose (soluble) and tricalcium phosphate (insoluble) are examined on the release profiles from pellets, using ibuprofen as a model drug with pH-dependent solubility. Also studied is the dependence of these profiles on the specific surface area, bulk density, apparent density, porosity and porosity parameters (pore size distribution, total pore surface area, mean pore diameter and pore shape), as determined by mercury intrusion porosimetry. Pellets with high porosity and total pore surface area but small median pore diameter (tricalcium phosphate pellets--IPM) are found to produce similar dissolution results to those of low porosity and low total pore surface area, but having a high median pore diameter (lactose pellets--ILM), irrespective of the solubility of excipients. Addition of citric acid causes a delay in the initial dissolution for both formulations. During dissolution, however, citric acid reduces the median pore diameter of lactose-based pellets. In contrast, in tricalcium phosphate/citric acid pellets (CIPM), this parameter increases considerably during dissolution, when compared to the IPM formulation. These findings may justify the contrasting dissolution behaviors of CIPM and CILM (lactose/citric acid) pellets, after their common behavior in the initial stages, and show that porosity and its related parameters, along with physical properties of excipients such as solubility, density and specific surface area, are helpful to predict pellet behavior in drug release profiles.http://www.sciencedirect.com/science/article/B6T7W-4B54142-4/1/d88c9200d18c56a3a1d6f0d0eb11578

Parameter space of experimental chaotic circuits with high-precision control parameters

ACKNOWLEDGMENTS The authors thank Professor Iberê Luiz Caldas for the suggestions and encouragement. The authors F.F.G.d.S., R.M.R., J.C.S., and H.A.A. acknowledge the Brazilian agency CNPq and state agencies FAPEMIG, FAPESP, and FAPESC, and M.S.B. also acknowledges the EPSRC Grant Ref. No. EP/I032606/1.Peer reviewedPublisher PD