336 research outputs found
Statistics of football dynamics
We investigate the dynamics of football matches. Our goal is to characterize
statistically the temporal sequence of ball movements in this collective sport
game, searching for traits of complex behavior. Data were collected over a
variety of matches in South American, European and World championships
throughout 2005 and 2006. We show that the statistics of ball touches presents
power-law tails and can be described by -gamma distributions. To explain
such behavior we propose a model that provides information on the
characteristics of football dynamics. Furthermore, we discuss the statistics of
duration of out-of-play intervals, not directly related to the previous
scenario.Comment: 7 page
On the dynamics of bubbles in boiling water
We investigate the dynamics of many interacting bubbles in boiling water by
using a laser scattering experiment. Specifically, we analyze the temporal
variations of a laser intensity signal which passed through a sample of boiling
water. Our empirical results indicate that the return interval distribution of
the laser signal does not follow an exponential distribution; contrariwise, a
heavy-tailed distribution has been found. Additionally, we compare the
experimental results with those obtained from a minimalist phenomenological
model, finding a good agreement.Comment: Accepted for publication in Chaos, Solitons & Fractal
The Contribution of the Smectic-Nematic Interface to the Surface Energy
The contribution of the smectic-nematic interface to the surface energy of a
nematic liquid crystal sample is analyzed. By means of a simple model it is
shown that the surface energy depends on the thickness of the region over which
the transition smectic-nematic takes place. For perfectly flat substrates this
thickness is of the order of the correlation length entering in the transition.
An estimate of this contribution shows that it is greater than the one arising
from the nematic-substrate interaction. Moreover, it is also shown that the
surface energy determined in this way presents a non-monotonic behavior with
the temperature.Comment: 10 pages, revte
Strategy for the development of a new stick formula without microplastics
Plastic is a synthetic, malleable, and durable material that has been used for various applications since its invention in the late 19th century. During its very long-time degradation process, mechanical and/or photochemical processes fragment plastic into increasingly smaller fragments called microplastics (MPs). In the cosmetic field, MPs are directly added to many products for various functions, including to exploit their exfoliating and structuring power. Unfortunately, it has been realized that MPs are not retained in purification plants and therefore end up in the aquatic environment causing a high problem of environmental pollution. Polyethene (PE) is the most widely used MP in cosmetics due to its use as a structuring agent, to provide consistency to formulations and as a key ingredient in lipsticks and mascaras. Given the limitations imposed by regulations and the growing demand from consumers for chemical-free and eco-friendly products, the common synthetic and petroleum-based waxes used in lipstick formulations, such as PE, must necessarily be replaced by natural waxes of plant origin. In this paper we report the development of a chemical-free and eco-friendly cosmetic stick. To achieve the goal, it was necessary to study the compatibility of the ABWAX® Revowax, natural alternative to PE, with oils and colours to predict the behaviour of these structuring waxes in more complex systems. Through a systematic comparative study, the two waxes showed similar thermal characteristics and showed similar penetration curves, presenting overall comparable performance in the MP-free finished product. We can therefore consider ABWAX® Revowax natural wax a valid alternative to PE
INTEGRATING EXPERTISES and AMBITIONS for DATA-DRIVEN DIGITAL BUILDING PERMITS - The EUNET4DBP
The digitalization of the process for building permit (involving the use of 3D information systems) is seen as a priority in a wide part of the world. Since it is a very multidisciplinary use case, involving a variety of stakeholders tackling complex issues and topics, some of them joined their efforts and skills in the European Network for Digital Building Permit. The initial activity of the network, after a review of on-going experiences, was a workshop to share knowledge about the topics involved and to identify the main ambitions of the network with respect to three pillars (i.e. Process - Rules and Requirements - Technology) and the related requirements. It was achieved through a collective brainstorming activity guided by digital tools, whose results were further analysed in a post-processing phase. Such results are presented in this paper and will be the base for planning the future network activity
Nonlinear anomalous diffusion equation and fractal dimension: Exact generalized gaussian solution
In this work we incorporate, in a unified way, two anomalous behaviors, the
power law and stretched exponential ones, by considering the radial dependence
of the -dimensional nonlinear diffusion equation where , ,
, and are real parameters and is a time-dependent
source. This equation unifies the O'Shaugnessy-Procaccia anomalous diffusion
equation on fractals () and the spherical anomalous diffusion for
porous media (). An exact spherical symmetric solution of this
nonlinear Fokker-Planck equation is obtained, leading to a large class of
anomalous behaviors. Stationary solutions for this Fokker-Planck-like equation
are also discussed by introducing an effective potential.Comment: Latex, 6 pages. To appear in Phys. Rev.
Absences from work among healthcare workers: are they related to influenza shot adherence?
BACKGROUND: The coverage for influenza vaccination among healthcare workers (HCWs) is inadequate in many countries despite strong recommendations; is there evidence that influenza vaccination is effective in preventing absenteeism? Aim of the study is to evaluate the influenza vaccination coverage and its effects on absences from work among HCWs of an Italian academic healthcare trust during the 2017-2018 influenza season. METHODS: We performed a retrospective study to identify predictive characteristics for vaccination, and a retrospective cohort study to establish the effect of vaccination on absences among the vaccinated and non-vaccinated cohorts between December 2017 and May 2018. Overall absence rates over the whole observation period and sub-rates over 14-days intervals were calculated; then comparison between the two groups were conducted applying Chi-square test.
RESULTS: Influenza vaccination coverage among 4419 HCWs was 14.5%. Age, university degree, medical care area and physician profile were positively associated with vaccine uptake. Globally during influenza season non-vaccinated HCWs lost 2.47/100 person-days of work compared to 1.92/100 person-days of work among vaccinated HCWs (p\u2009<\u20090.001); significant differences in absences rates resulted when focusing on the influenza epidemic peak. CONCLUSIONS: Factors predicting influenza uptake among HCWs were male sex, working within medical care area and being a physician. Absenteeism among HCWs resulted to be negatively correlated with vaccination against influenza. These findings add evidence to the urgent need to implement better influenza vaccination strategies towards HCWs to tackle vaccine hesitancy among professionals
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