Human immunodeficiency virus (HIV) continues to be a major global public health issue and omnipresent sexually transmitted infections (STIs) increase the risk of HIV acquisition. Moreover, STIs in pregnant women can harm unborn child. In this study, we systematically investigated prevalence HIV, relevant vaginal group B streptococcus colonization among presenting at Asella Teaching Hospital central Ethiopia their effect on perinatal mortality. A follow-up was performed six weeks after...

We present a user-friendly open-source MATLAB\textsuperscript{\textregistered} package developed by the research group Turbulence, Wind energy and Stochastics (TWiSt) at Carl von Ossietzky University of Oldenburg. Firstly, this helps user to perform very basic statistical analysis given turbulent data set which we believe be useful entire turbulence community. It can used estimate quantities such as spectrum density, intensity, integral length scale, Taylor microscale, Kolmogorov scale...

Processes leading to anomalous fluctuations in turbulent flows, referred as intermittency, are still challenging. We consider cascade trajectories through scales realizations of a stochastic Langevin process for which multiplicative noise is an intrinsic feature the state. The conditioned on their entropy exchange. Such selected concentrate around optimal path, called instanton, minimum effective action. action derived from equation, estimated measured data. In particular instantons with...

Multi-scale statistics are used to analyse the flow structure of wake in boundary layer a wind turbine array. Experimentally, 3×3 array is tested with X-type hot-wire anemometry, providing velocity signal at discrete locations downstream along centreline centre turbine. Based on Markov property, turbulent cascade can be taken as stochastic process scale, for which an underlying Fokker-Planck equation and its Kramers-Moyal coefficients assigned. The first two terms expansion (drift diffusion...

Features of the turbulent cascade are investigated for various datasets from three different flows, namely free jets as well wake flows a regular grid and cylinder. The analysis is focused on question to whether fully developed show universal small-scale features. Two approaches used answer this question. First, two-point statistics, structure functions longitudinal velocity increments, and, second, joint multiscale statistics these increments analysed. characterisation encompasses whole in...

Fundamental results in nonequilibrium thermodynamics are shown to be associated with small-scale features of turbulent flows. The estimation entropies allows the selection distinct realizations cascade trajectories through a hierarchy spatial scales. Entropy-consuming lead intermittent structures piling up velocity increments and finite ``jumps.'' This finding is interest for fundamental questions on singularities or rare extreme gradients.

Abstract Based on direct numerical simulations with point-like inertial particles, Stokes numbers St = 0, 0.5, 3, and 6, transported by homogeneous isotropic turbulent flows, we present in this letter for the first time evidence existence of Markov property Lagrangian turbulence. We show that is valid a finite step size larger than Stokes-number-dependent Einstein-Markov coherence scale. This enables description multi-scale statistics particles Fokker-Planck equations, which can be embedded...

L’énergie électrique est l’une des formes d’énergie les plus précieuses, car elle peut être transportée de manière optimale et convertie en d’autres avec faibles pertes. La plupart scénarios d’avenir prévoient que la consommation continuera à augmenter significative, part énergies renouvelables, raison leur abondance, ira également croissant. Dans présente contribution, on se concentre sur l’énergie éolienne, dont discute le fonctionnement contribution l’approvisionnement énergétique global.

Abstract The models prescribed by the IEC standard for generation of wind fields, as well intermittent modifications original models, are used inflows in LES. behaviour fields is investigated with regard to higher-order moments. It shown that all reach an state This can be determined intermittency parameter and higher orders seen Kaimal model generates significantly lower than other models. convergence length reduced a correct description fields.

Electrical energy is one of the most valuable forms energy, as it can be optimally transported and converted into other with low losses. Most future scenarios predict that electrical consumption will continue to grow significantly, share renewable energies, due their abundance, also increase. This contribution focuses on wind power, discussing how works its overall supply.

The relationship between fundamental quantities of turbulent flows like the dissipation constant $C_\varepsilon$ and intermittency factor $\mu$, expected to be for homogeneous isotropic turbulence, is explored with respect their a wider class non-ideal flows. For energy cascade, known reflect its basic overall properties, while $\mu$ quantifies emerging down cascade. Using very large dataset wakes, grid-generated turbulence an axisymmetric jet, we find that inversely proportional...

Due to its very low viscosity, cryogenic helium has been used for years generate high Reynolds turbulent flows. The measurement of velocity fluctuations in such flows is however a challenging issue, as it necessary develop small size (typically micron-length), robust sensors, measure the whole spectrum velocity, which may extend hundreds kHz and possibly higher. SBT developed different facilities, particular taking benefit refrigeration capacities available at CEA Grenoble. In this article...

We describe a simple stochastic method, so-called Langevin approach, which enables one to extract evolution equations of variables from set measurements. Our method is parameter-free and it based on the nonlinear equation. Moreover, can be applied not only processes in time, but also scale, given that data available shows ergodicity. This chapter introduces mathematical foundations approach describes how implement numerically. A specific application presented, namely turbulent velocity field...

We intend to study some problems related the asymptotic behaviour of a physical system evolution which is markovian. The typical example such an furnished by homogeneous discrete chain with finite number possible states considered first A. Markoff. In §1 we recall briefly main results this theory and in §2 treat its obvious generalization continuous parameter case. §3 pass proper object paper establish limit theorem for time-homogeneous Markoff processes. This then extended nonhomogeneous...

&L» ==/(.) e t2 la fonction A '( ., co )==/(.).C'est le théorème de représentation J. L. DOOB ([11] p. i4 et 49-5o).Nous nous restreindrons en principe aux processus du type Markov.On entend par là que, si t << T. loi probabilité .1 (ï, ûû) dépend valeur prise A. '{t., c»)) mais, une fois cette fixée, est stochastiquement indépendante Y ensemble des variables aléatoires j^T(^, ex)), t'<^t\.Puisque sommes dans domaine réel, définirons donnée d'une répartition, ce qui revient à n'envisager sur...

We intend to study some problems related the asymptotic behaviour of a physical system evolution which is markovian. The typical example such an furnished by homogeneous discrete chain with finite number possible states considered first A. Markoff. In §1 we recall briefly main results this theory and in §2 treat its obvious generalization continuous parameter case. §3 pass proper object paper establish limit theorem for time-homogeneous Markoff processes. This then extended nonhomogeneous...