Search results for "eccentricity"
showing 10 items of 38 documents
Osmium and lithium isotope evidence for weathering feedbacks linked to orbitally paced organic carbon burial and Silurian glaciations
2022
Abstract The Ordovician (∼487 to 443 Ma) ended with the formation of extensive Southern Hemisphere ice sheets, known as the Hirnantian glaciation, and the second largest mass extinction in Earth History. It was followed by the Silurian (∼443 to 419 Ma), one of the most climatically unstable periods of the Phanerozoic as evidenced by several large scale ( > 5 ‰ ) carbon isotope (δ13C) perturbations associated with further extinction events. Despite several decades of research, the cause of these environmental instabilities remains enigmatic. Here, we provide osmium (187Os/188Os) and lithium (δ7Li) isotope measurements of marine sedimentary rocks that cover four Silurian δ13C excursions. Osmi…
Signature of the presence of a third body orbiting around XB 1916-053
2015
The ultra-compact dipping source \object{XB 1916-053} has an orbital period of close to 50 min and a companion star with a very low mass (less than 0.1 M$_{\odot}$). The orbital period derivative of the source was estimated to be $1.5(3) \times 10^{-11}$ s/s through analysing the delays associated with the dip arrival times obtained from observations spanning 25 years, from 1978 to 2002. The known orbital period derivative is extremely large and can be explained by invoking an extreme, non-conservative mass transfer rate that is not easily justifiable. We extended the analysed data from 1978 to 2014, by spanning 37 years, to verify whether a larger sample of data can be fitted with a quadra…
Measurement of residual stresses by the hole-drilling method: Influence of hole eccentricity
1979
The hole-drilling method is a semidestructive technique which allows the measurement of residual stresses. In this method, a source of error is due to the misalignment between the hole and rosette centres. This paper presents a theoretical analysis of the influence of such misalignment on the strains measured by the rosette. Formulae which give the residual stresses taking account of the hole eccentricity are derived. Finally, the errors, which affect the residual stresses when the eccentricity is neglected, are evaluated for some commercial strain-gauge rosettes especially developed for the hole-drilling method.
Review of Some Development of the Hole Drilling Method
1990
This paper contains a survey of some developments of the hole drilling method. It is mainly based on the research work carried out at the University of Palermo in the years from 1978 to 1989. The paper considers the relationship between the relaxed strain and the residual stresses for a rosette with an off-centre hole, the influence of hole eccentricity on the determination of residual stresses and of rosette calibration constants, the sensitivity of strain relaxation.
"Table 5" of "ATLAS measurements of the properties of jets for boosted particle searches"
2012
The jet eccentricity distribution for R=0.6 and high mass (M>100 GEV) jets in the full 2010 dataset corrected for pileup and corrected to the particle level.
"Table 6" of "ATLAS measurements of the properties of jets for boosted particle searches"
2012
The jet eccentricity distribution for R=1.0 and high mass (M>100 GEV) jets in the full 2010 dataset corrected for pileup and corrected to the particle level.
Chaotic dynamics around cometary nuclei
2017
We apply a generalized Kepler map theory to describe the qualitative chaotic dynamics around cometary nuclei, based on accessible observational data for five comets whose nuclei are well-documented to resemble dumb-bells. The sizes of chaotic zones around the nuclei and the Lyapunov times of the motion inside these zones are estimated. In the case of Comet 1P/Halley, the circumnuclear chaotic zone seems to engulf an essential part of the Hill sphere, at least for orbits of moderate to high eccentricity.
Behavior of fiber-reinforced concrete columns under axially and eccentrically compressive loads
2010
An experimental investigation into the behavior of 16 short, confined, reinforced concrete columns with and without steel fibers was carried out. The columns with square sections had a concrete core 165 x 165 mm (6.49 x 6.49 in.) at the midsection and were hunched at the ends to apply eccentric loading and prevent boundary effects. The specimens were tested to failure at different strain rates under two loading schemes: concentric compression and eccentric compression with a constant eccentricity. The axial load and axial strains were obtained to evaluate the effects of the presence of steel fibers, the thickness of the cover concrete, and the eccentricity of the applied axial load. The com…
Perception of Biological Motion in Central and Peripheral Visual Fields
2017
Abstract Studies analysing biological motion perception based on reduced number of dots have demonstrated that biological motion can be perceived even when only the lower part of the body is visible or when the number of dots representing the object is reduced. What is the minimal amount of information that enables biological motion to be distinguished from its scrambled version? The results of the current experiment demonstrate that biological motion can be distinguished from its scrambled version when the object is formed of approximately 5 (4.7 ± 0.1) dots. Additionally, we also investigated whether the threshold value for biological motion perception differs in central and peripheral vi…
Hot spots and gluon field fluctuations as causes of eccentricity in small systems
2021
We calculate eccentricities in high energy proton-nucleus collisions, by calculating correlation functions of the energy density field of the Glasma immediately after the collision event at proper time tau = 0. We separately consider the effects of color charge and geometrical hot spot fluctuations, analytically performing the averages over both in a dilute-dense limit. We show that geometric fluctuations of hot spots inside the proton are the dominant source of eccentricity whereas color charge fluctuations only give a negligible correction. The size and number of hot spots are the most important parameters characterizing the eccentricities.