Which Radial Velocity Exoplanets Have Undetected Outer Companions?

(Abridged) The observed radial velocity (RV) eccentricity distribution for extrasolar planets in single-planet systems shows that a significant fraction of planets are eccentric ($e > 0.1$). Here we investigate the effects on an RV planet's eccentricity produced by undetected outer companions. We have carried out Monte Carlo simulations of mock RV data to understand this effect and predict its impact on the observed distribution. We first quantify the statistical effect of undetected outer companions and show that this alone cannot explain the observed distribution. We then modify the simulations to consist of two populations, one of zero-eccentricity planets in double-planet systems and the other of single planets drawn from an eccentric distribution. Our simulations show that a good fit to the observed distribution is obtained with 45% zero-eccentricity double-planets and 55% single eccentric planets. Matching the observed distribution allows us to determine the probability that a known RV planet's orbital eccentricity has been biased by an undetected wide-separation companion. Our simulations show that moderately-eccentric planets, with $0.1 < e < 0.3$ and $0.1 < e < 0.2$, have a $\sim 13$ and $\sim 19$ probability, respectively, of having an undetected outer companion. We encourage both high-contrast direct imaging and RV follow-up surveys of known RV planets with moderate eccentricities to test our predictions and look for previously undetected outer companions.Comment: 23 pages (12 text, 2 tables, 9 figures). Accepted to the Astrophysical Journal 30 June 200

Mapping the Asymmetric Thick Disk: The Hercules Thick Disk Cloud

The stellar asymmetry of faint thick disk/inner halo stars in the first quadrant first reported by Larsen & Humphreys (1996) and investigated further by Parker et al. (2003, 2004) has been recently confirmed by SDSS (Juric et al. 2008). Their interpretation of the excess in the star counts as a ringlike structure, however, is not supported by critical complimentary data in the fourth quadrant not covered by SDSS. We present stellar density maps from the Minnesota Automated Plate Scanner (MAPS) Catalog of the POSS I showing that the overdensity does not extend into the fourth quadrant. The overdensity is most probably not a ring. It could be due to interaction with the disk bar, evidence for a triaxial thick disk, or a merger remnant/stream. We call this feature the Hercules Thick Disk Cloud.Comment: 11 pages, 5 figures, to be published in Astrophysical Journal Letter

Differential algebras on kappa-Minkowski space and action of the Lorentz algebra

We propose two families of differential algebras of classical dimension on kappa-Minkowski space. The algebras are constructed using realizations of the generators as formal power series in a Weyl super-algebra. We also propose a novel realization of the Lorentz algebra so(1,n-1) in terms of Grassmann-type variables. Using this realization we construct an action of so(1,n-1) on the two families of algebras. Restriction of the action to kappa-Minkowski space is covariant. In contrast to the standard approach the action is not Lorentz covariant except on constant one-forms, but it does not require an extra cotangent direction.Comment: 16 page

RECONSTRUCTION OF EXISTING LIVESTOCK FEED PRODUCTION PLANTS BY ADDING A HYDRAULIC ADDER

Recipes determine the quality of livestock feed and the hydraulic adders are one of the elements determining if the given recipe will be carried out. Generally, construction of existing adders does not allow accomplishment of that aim i.e. they do not meet recipe requirements. Consequently, researches which determined deviations in ingredient adding present with existing adders and with the experimental hydraulic adder were conducted. The research was conducted for two years (2005 and 2006) in two livestock feed factories in the Republic of Croatia on samples of feed mixtures for pigs weighing up to 15 and 25 kilos. Relative error was the means for comparison of weighing deviations between the hydraulic adder and the adders powered by means of an electric motor. Research results indicate that none of the two observed livestock feed production plants in 30 repetitions for two kinds of feed mixture showed a feed mixture weighing that would correspond to the specifications in the recipe. Additionally, hydraulic adders showed a greater precision in adding fish meal, extruded soybean and soybean meal when compared with the adders powered by means of an electric motor. However, the adders powered by means of an electric motor showed greater precision in adding corn. Based on the research results it can be concluded that using hydraulic adders instead of the adders powered by means of an electric motor will result in more accuracy in dosing ingredients with fine and middle granularity, whereas this can not be applied to dosing coarse grained ingredients

Differential structure on kappa-Minkowski space, and kappa-Poincare algebra

We construct realizations of the generators of the $\kappa$-Minkowski space and $\kappa$-Poincar\'{e} algebra as formal power series in the $h$-adic extension of the Weyl algebra. The Hopf algebra structure of the $\kappa$-Poincar\'{e} algebra related to different realizations is given. We construct realizations of the exterior derivative and one-forms, and define a differential calculus on $\kappa$-Minkowski space which is compatible with the action of the Lorentz algebra. In contrast to the conventional bicovariant calculus, the space of one-forms has the same dimension as the $\kappa$-Minkowski space.Comment: 20 pages. Accepted for publication in International Journal of Modern Physics

Chronic locomotor impairments among workers from an aluminium plant

U radu su analizirani učinci fluora na lokomotorni sustav radnika zaposlenih u proizvodnji aluminija. Praćeno je 328 radnika, koji su radili između pet i dvanaest godina, koliko d postoji tvornica. Značajna karakteristika je da su radnici primljeni na posao zdravi. Dvije trećine radnika bile su mlađe od 30 godina, a tek jedna trećina je u četvrtom desetljeću života. Do pete godine praćenja nije bilo razlike u učestalosti koštano-zglobnih promjena između radnika zaposlenih u pogonu elektrolize aluminija i ljevača. Nakon toga počeli su se javljati lumbosakralni sindrom, upale tetiva ekstenzora šaka te rotatora ramena. Osteoskleroza i pojačana trabekulacija pojavila se u četiri radnika u pogonu elektrolize, da bi se slijedećih godina povećala za po četiri slučaja godišnje. U desetoj godini praćenja u 28 radnika našli smo sve znakove osteofluoroze.Effects of fluorine (fluorides) on the locomotor system in workers employed in an aluminium reduction plant are analysed. Two groups of 328 workers each, who spent five to twelve years in the potroom and casting unit respectively, were followed .up during a twelve-year period. All the workers were healthy when -they began to work. Two-thirds of them were less than 30 years old, and one third were in their forties. Up to the fifth year of follow-up there was no difference in the frequency of bone and joint complaints between the workers in the potroom and those in the casting unit. Lumbo-sacral syndrome, inflammation of the extensor carpi tendons and rotatory shoulder tendons occurred after that period. Osteosclerosis and abundant trabeculation occurred in four potroom workers, keeping at a yearly rate of four cases in the following years. In the tenth year of follow up all the signs of osteofluorosis were present in 28 potroom workers

Developing correlations between the soil fines content and CPT results using neural networks

Knowledge of the fines content is necessary for all soil classification systems and an important factor in the evaluation of soil strength in liquefaction and seismic settlement analysis. This paper presents the application of cone penetration test, CPT data for estimating the soil fines content. The correlation can be used either as a first estimate of fines content (for example in the offshore environment) or to provide statistical information on the variation of fines content within a given area of interest (e.g. for a regional liquefaction study). The paper shows how field and laboratory test data were used with a neural network to correlate the CPT results and the fines content. Data from five site investigation locations across Northern Croatia were utilised. Verification of the approach is performed using field and lab test data from the Veliki vrh landslide.Geo-engineerin