1,477 research outputs found
The Orbit of the New Milky Way Globular Cluster FSR1716 =VVV-GC05
Indexación: Scopus.We use deep, multi-epoch near-IR images of the VISTA Variables in the Via Lictea (VVV) Survey to measure proper motions (PMs) of stars in the Milky Way globular cluster (GC) FSR1716 = VVV-GC05. The colormagnitude diagram of this object, made by using PM-selected members, shows an extended horizontal branch, nine confirmed RR Lyrae (RRL) members in the instability strip, and possibly several hotter stars extending to the blue. Based on the fundamental-mode (ab-type) RRL stars that move coherently with the cluster, we confirmed that FSR1716 is an Oosterhoff I GC with a mean period aPabn = 0.574 days. Intriguingly, we detect tidal extensions to both sides of this cluster in the spatial distribution of PM-selected member stars. Also, one of the confirmed RRabs is located -11 arcmin in projection from the cluster center, suggesting that FSR1716 may be losing stars due to the gravitational interaction with the Galaxy. We also measure radial velocities (RVs) for five cluster red giants selected using the PMs. The combination of RVs and PMs allow us to compute for the first time the orbit of this GC, using an updated Galactic potential. The orbit results to be confined within|Zmax| < 2.0 kpc, and has eccentricity 0.4 < e < 0.6, with perigalactic distance 1.5 < Rperi (kpc) < 2.3, and apogalactic distance 5.3 < Rapo (kpc) < 6.4. We conclude that, in agreement with its relatively low metallicity ([Fe/H] =-1.4 dex), this is an inner-halo GC plunging into the disk of the Galaxy. As such, this is a unique object with which to test the dynamical processes that contribute to the disruption of Galactic GCs. © 2018. The American Astronomical Society. All rights reserved.https://iopscience.iop.org/article/10.3847/1538-4357/aacd0
The MIDAS telescope for microwave detection of ultra-high energy cosmic rays
We present the design, implementation and data taking performance of the
MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view
imaging telescope designed to detect microwave radiation from extensive air
showers induced by ultra-high energy cosmic rays. This novel technique may
bring a tenfold increase in detector duty cycle when compared to the standard
fluorescence technique based on detection of ultraviolet photons. The MIDAS
telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera,
instrumented with feed horns operating in the commercial extended C-Band (3.4
-- 4.2 GHz). A self-trigger capability is implemented in the digital
electronics. The main objectives of this first prototype of the MIDAS telescope
- to validate the telescope design, and to demonstrate a large detector duty
cycle - were successfully accomplished in a dedicated data taking run at the
University of Chicago campus prior to installation at the Pierre Auger
Observatory.Comment: 13 pages, 18 figure
Electrostatic and electrokinetic contributions to the elastic moduli of a driven membrane
We discuss the electrostatic contribution to the elastic moduli of a cell or
artificial membrane placed in an electrolyte and driven by a DC electric field.
The field drives ion currents across the membrane, through specific channels,
pumps or natural pores. In steady state, charges accumulate in the Debye layers
close to the membrane, modifying the membrane elastic moduli. We first study a
model of a membrane of zero thickness, later generalizing this treatment to
allow for a finite thickness and finite dielectric constant. Our results
clarify and extend the results presented in [D. Lacoste, M. Cosentino
Lagomarsino, and J. F. Joanny, Europhys. Lett., {\bf 77}, 18006 (2007)], by
providing a physical explanation for a destabilizing term proportional to
\kps^3 in the fluctuation spectrum, which we relate to a nonlinear ()
electro-kinetic effect called induced-charge electro-osmosis (ICEO). Recent
studies of ICEO have focused on electrodes and polarizable particles, where an
applied bulk field is perturbed by capacitive charging of the double layer and
drives flow along the field axis toward surface protrusions; in contrast, we
predict "reverse" ICEO flows around driven membranes, due to curvature-induced
tangential fields within a non-equilibrium double layer, which hydrodynamically
enhance protrusions. We also consider the effect of incorporating the dynamics
of a spatially dependent concentration field for the ion channels.Comment: 22 pages, 10 figures. Under review for EPJ
Charm and hidden charm scalar mesons in the nuclear medium
We study the renormalization of the properties of low lying charm and hidden
charm scalar mesons in a nuclear medium, concretely of the D_{s0}(2317) and the
theoretical hidden charm state X(3700). We find that for the D_{s0}(2317), with
negligible width at zero density, the width becomes about 100 MeV at normal
nuclear matter density, while in the case of the X(3700) the width becomes as
large as 200 MeV. We discuss the origin of this new width and trace it to
reactions occurring in the nucleus, while offering a guideline for future
experiments testing these changes. We also show how those medium modifications
will bring valuable information on the nature of the scalar resonances and the
mechanisms of the interaction of D mesons with nucleons and nuclei
Crowdfunding in the production of video games in Spain: Evolution and success on Kickstarter
This research addresses the use of crowdfunding platforms for the development of video games in Spain. It is part of the group of platform-centred research in order to develop a quantitative analysis of the data contained in them. Specifically, the data provided by Kickstarter for Spanish video game development projects is analysed. Normality tests indicated that the variables do not follow a normal distribution, hence non-parametric tests were used. The success rate of Spanish campaigns is 28.4% for the total number of cases, 40.8% in 2020, which is a steady growth since 2015. The average funding is €16,586.76, €50,056.67 for successful campaigns; however, the median indicates that 50% of the sample does not exceed €1,653 in funding. Regression models are used to develop equations to calculate the amount of funding needed to publish on PC and console, and the number of backers needed to achieve a given amount of funding
Alimento fermentado a base de caña de azúcar (saccharum spp.) En el cambio de peso de bovinos en pastoreo
The effect of Saccha-polishing (fermented feed in the solid stage based on sugar cane and rice polishing), with different levels of beef fat on the weight change of young grazing beef bulls in finalization, was evaluated. Twenty-seven young beef bulls were used with initial live weights of 357.325.1 kg, distributed randomly in three treatments with nine repetitions. The treatments (T) were: T1: GrassSaccha-polishing, T2: T1100 g of beef fat and T3: T1200 g of beef fat. The supplement was offered daily in the amount of 7 g MS kg1 of live weight in individual pens, then, all animals came out to graze on the same pasture. The animals without fasting were weighed for three consecutive days at the beginning of the experiment and later, every 30 days. A completely random design was used with repeated measures in time. The initial weight was used as covariable, and no differences were found in the consumption of the supplement (2.13, 2.10 and 2.05 kg of MS animal day1 for T1, T2 and T3, respectively), or in the daily weight gain (DWG) (1.03, 1.04 and 1.02 kg animal day1 for T1, T2 and T3, respectively). The DWGs are within the highest values reported by other studies using different supplements, highlighting that the source of food based on Saccha-polishing can be used to supplement cattle nutrition with grazing, without the addition of beef fat
Estimating the global conservation status of more than 15,000 Amazonian tree species
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century
Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV
Peer reviewe
Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search
Peer reviewe
Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks
Peer reviewe
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